• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.36 no.2
• /
• pp.24-32
• /
• 2004

Toner used in xerographic printing process is hydrophobic powder with low surface energy. The toner ink film fused on paper surface can be efficiently detached from a fiber surface during pulping, but it does not fragment again into fine toner particles. Ink agglomerates that result have too large particle size to be deinked by flotation. The purpose of this study is to enhance toner agglomeration using 1-octadecanol for improving the toner removal by screening. The effect of pH, pulping temperature, and 1-octadecanol on toner agglomeration and removal by screening was investigated using image analysis methods. Results showed that the size of toner agglomerates increased substantially when pulping was carried out at high temperature under acidic condition. When toner agglomerates showed spherical shape, the particle removal efficiency of screening was improved.

• Korean Journal of Microbiology
• /
• v.44 no.1
• /
• pp.29-36
• /
• 2008

Nitrogen is one of the major pollutants that should be removed by wastewater treatment systems. Biological nitrogen removal (BNR) is a key technology in advanced wastewater treatment systems operated by bacterial populations. Nitrification is the first step of microbiological processes in BNR system. Ammonia is oxidized to nitrite by ammonia-oxidizing bacteria (AOB) and then nitrite is subsequently oxidized to nitrate by nitrite-oxidizing bacteria (NOB). The diversity of NOB in nitrification reactors of 3 BNR systems, Edited biological aerated filter system, Nutrient removal laboratory system, and the Rumination type sequencing batch reactor system, was investigated by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA genes. Cluster analysis of T-RF profiles showed that communities of Nitrobacter group in each system were different depending upon the process of systems. However, the clusters of Nitrospira group were divided by the habitat of aqueous and solid samples.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2000.10a
• /
• pp.128-135
• /
• 2000

The thiosulfate reductase gene (PhsABC) from Salmonella typhimurium was expressed in Escherichia coli in order to produce sulfide from inorganic thiosulfate and precipitate metals as metal sulfide complexes. A 5.1-kb DNA fragment containing the native phsABC and a 3.7-kb DNA fragment, excluding putative promoter and regulatory regions were inserted into expression vectors pTrc99A and pJB866, respectively. Upon expression of phsABC, E. coli DH5$\alpha$ harboring the phsABC constructs showed higher thiosulfate reductase activity and produced significantly more sulfide than the control strain (E. coli DH5$\alpha$) under both aerobic and anaerobic conditions. Among the four constructs, E. coli DH5$\alpha$ harboring pSB74 produced the highest level of thiosulfate reductase and removed most of heavy metals from solution under anaerobic conditions. In a mixture of 100 $\mu$M each of cadmium, lead, and zinc, the strain could remove $99\%$ of the total metals from solution within 10 hours. Cadmium was removed first, lead second, and zinc last. In contrast, a negative control did not produce any measurable sulfide and removed very little metals from solution. These results have important implications for removal of metals from wastewater contaminated with several metals.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.36 no.2
• /
• pp.288-292
• /
• 2009

A crown-root fracture is defined as a fracture involving enamel, dentin, and cementum. The fractures may be grouped according to pulpal involvement into uncomplicated and complicated. Generally a vertically crown-root fractured tooth must be extracted. However, it should be mentioned that the cases have been reported where bonding of the coronal fragment has led to consolidation of the intraalveolar part of the fracture. Definitive conservative therapy comprises one of four treatment alternatives; fragment removal only, fragment removal with gingivectomy, orthodontic extrusion of apical fragment, and surgical extrusion of apical fragment. The choice is primarily determined by the exact information on the site and the type of fracture, but the cost and the complexity of treatment can also be decisional factors. On the other hand, intentional replantation of the teeth with vertical root facture reconstructed with resin bonding has emerged as a new promising method in recent years. This case presents an intentional replantation of the crown-root fractured maxillary central incisor reconstructed with resin bonding. However, an obvious increase of radiolucency was observed after 4 months and the tooth was re-fractured after 16 months.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.39 no.5
• /
• pp.251-253
• /
• 2013

Inferior alveolar nerve block obtained maximum anesthetic effect using a small dose of local anesthetic agent, which also has low a complication incidence. Complications of an inferior alveolar nerve block include direct nerve damage, bleeding, trismus, temporary facial nerve palsy, and etc. Among them, the major iatrogenic complication is dental needle fracture. A fragment that disappears into the soft tissue would be hard to remove, giving rise to a legal problem. A 31-year-old woman was referred for the removal of a broken needle, following an inferior alveolar nerve block. Management involved the removal of the needle under local anesthesia with pre- and peri-operative computed tomography scans.

• Journal of Korean Neurosurgical Society
• /
• v.47 no.3
• /
• pp.217-220
• /
• 2010

A 73-year-old male presented with a rare dorsally sequestrated lumbar disc herniation manifesting as severe radiating pain in both leg, progressively worsening weakness in both lower extremities, and urinary incontinence, suggesting cauda equina syndrome. Magnetic resonance imaging suggested the sequestrated disc fragment located in the extradural space at the L4-L5 level had surrounded and compressed the dural sac from the lateral to dorsal sides. A bilateral decompressive laminectomy was performed under an operating microscope. A large extruded disc was found to have migrated from the ventral aspect, around the thecal sac, and into the dorsal aspect, which compressed the sac to the right. After removal of the disc fragment, his sciatica was relieved and the patient felt strength of lower extremity improved.

• Journal of Trauma and Injury
• /
• v.25 no.4
• /
• pp.267-270
• /
• 2012

A 27 year-old man, who had a penetrating cardiac injury due to a metal fragment was transferred to our hospital. At admission, his vital signs were stable, and his chest film showed a foreign-body-like finding in the heart silhouette. We evaluated the patient with chest computed tomography and echocardiography for further information. Finally, we removed the metal fragment from the left ventricle by using a cardiopulmonary bypass.

• The Journal of the Korean dental association
• /
• v.52 no.2
• /
• pp.60-68
• /
• 2014

Nickel-Titanium(NiTi) rotary instruments have brought a big step toward "efficient" practice of endodontic procedure. The rotary files help clinicians to reduce their working time and also increase the clinical success rate with minimal procedural errors by stainless steel instruments. In spite of these advantages, NiTi instruments still have a few drawbacks including unpredictable fatigue fracture. Clinicians may reduce the potential risk of instruments fracture by following some clinical guidelines for rotary instruments. In some clinical cases of instruments fracture, we may try to remove the instruments' fragments or bypass the fragment to reach the apical canal. In some limited cases, the fractured instruments' fragments would not jeopardize the clinical prognosis of root canal treatment. However, it is impossible to be overemphasized that the fragment removal is more difficult than the prevention of fracture. Clinicians need to understand the fracture mechanisms and, in clinic, need to discard the used instruments timely.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.23 no.1
• /
• pp.31-39
• /
• 2001

The purpose of this study is to reveal the factors leading to the problem of unilateral condylar fractures and suggest a treatment guideline of treatment for good prognosis in surgical treatment. The factors can be age, sex, fracture site, degree of displacement, posterior occlusion loss, post-operative alteration of condylar head position, post-operative condylar head resorption, and maxillomandibular fixation period. One hundred and eleven patients with unilateral condylar fractures, who were treated by surgical method from 1990 Feb. to 2000 Feb., were studied. Minimum follow-up period was 6 months. The results were as follows ; 1. In the age group of $41{\sim}60$, females had significantly higher complication rate than males, therefore we must be careful about treatment of female in this age group 2. In level I fractures of the mandibular condyle, because there were abundant complications when the patients were treated with fragment removal, conservative treatment is recommended over the surgical approach. 3. There were no differences in the complication rate, in the level II, III fractures. but were severe complications in the cases of patients treated by Dr.Nam's method or fragment removal. Therefore, open reduction and internal fixation is recommended over Dr.Nam's method or fragment removal. 4. In level IV fractures, open reduction and internal fixation is recommended 5. Although there was a higher complication rate depending on the degree of deviation, there was no correlation between the degree of deviation and development of complications in each level of fracture 6. Because the complication rate was higher in cases of condylar resorption, vertical dimension loss, and alteration of condylar head position, we must make an effort to prevent such complications during treatment

• Journal of radiological science and technology
• /
• v.39 no.2
• /
• pp.185-191
• /
• 2016

The objective of this study was to detect the fragments generated during IV (intravenous) catheter injection of contrast medium and drug administration in a clinical setting and removal was performed by experimentally producing a phantom, and to compare the radiography, ultrasonography, and multi-detector computed tomography (MDCT) imaging and radiation dose. A 1 cm fragment of an 18 gage Teflon$^{(R)}$ IV catheter with saline was inserted into the IV control line. Radiography, CT, and ultrasonography were performed and radiography and CT dose were calculated. CT and ultrasonography showed an IV catheter fragment clinically and radiography showed no visible difference in the ability to provide a useful image of an IV catheter fragment modality (p >.05). Radiography of effective dose ($0.2139mSv{\cdot}Gy^{-1}{\cdot}cm^{-2}$) form DAP DAP ($0.93{\mu}Gy{\cdot}m^2 $), and dose length product (DLP) ($201mGy{\cdot}cm$) to effective dose was calculated as 0.483 mSv. IV catheter fragment were detected of radiography, ultrasonography and CT. These results can be obtained by menas of an excellent IV catheter fragment of detection capability CT. However, CT is followed by radiation exposure. IV catheter fragment confirming the position and information recommend an ultrasonography.