• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.11
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• pp.434-443
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• 2016

The evaporation of water from an aqueous solution is widely used in the food, desalination, pulp, and chemical industries. Usually, a large amount of energy is consumed in the evaporation process to boil off water due to atmospheric pressure. As a way of improving the energy efficiency of the evaporation process, the combination of multiple effect evaporation and thermal vapor recompression has been proposed and has become a successful technique. In this study, 4 multiple-effect falling film type evaporators for sugar solution are designed and the energy efficiency of the system is analyzed in response to the selection of the steam ejector position. Energy efficiency is increased and vapor is more compressed in the steam ejector as the Thermal Vapor Recompression (TVR) is arranged in the rear part of the evaporator system. A simplified 0-dimensional evaporator model is developed using non-linear equations derived from mass balances, energy balances, and heat transfer equations. Steam economy is calculated to compare the evaporation performance of the 4 proposed evaporators. The entrainment ratio, compression ratio, and expansion ratio are computed to check the ejector performance.

• International Journal of Oral Biology
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• v.39 no.4
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• pp.177-185
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• 2014

Transfection is a gene delivery tool that is a popular means of manipulating cellular properties, such as induced pluripotent stem cell (iPSC) generation by reprogramming factors (Yamanaka factors). However, the efficiency of transfection needs to be improved. In the present study, three transfection protocols - non-liposomal transfection (NLT), magnetofection and electroporation - were compared by analysis of their transfection efficiencies and cell viabilities using human dental pulp cells (hDPC) and bovine fetal fibroblasts (bFF) as cell sources. Enhanced green fluorescent protein gene was used as the delivery indicator. For magnetofection, Polymag reagent was administrated. NLT, FuGENE-HD and X-treme GENE 9 DNA transfection reagents were used for NLT. For electroporation, the $Neon^{TM}$ and $NEPA21^{TM}$ electroporators were tested. $Neon^{TM}$ electroporation showed highest transfection efficiency when compared with NLT, magnetofection, and $NEPA21^{TM}$ electroporation, with transfection efficiency of about 33% in hDPC and 50% in bFF, based on viable cell population in each cell type. These results suggest that transfection by $Neon^{TM}$ electroporation can be used to deliver foreign genes efficiently in human and bovine somatic cells.

• Imaging Science in Dentistry
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• v.50 no.3
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• pp.183-192
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• 2020

Purpose: This study was performed to assess the accuracy of preoperative cone-beam computed tomography (CBCT), when justified for other reasons, in locating the apical foramen and establishing the working length. Materials and Methods: Six electronic databases were searched for studies on this subject. All studies, of any type, were included if they compared measurements of working length with preoperative CBCT to measurements using an electronic apex locator (EAL) or histological reference standard. Due to the high levels of heterogeneity, an inverse-variance random-effects model was chosen, and weighted mean differences were obtained with 95% confidence intervals and P values. Results: Nine studies were included. Compared to a histological reference standard, CBCT indicated that the apical foramen was on average 0.40 mm coronal of its histological position, with a mean absolute difference of 0.48 mm. Comparisons were also performed to an EAL reference standard, but the conclusions could not be considered robust due to high levels of heterogeneity in the results. Conclusion: A low level of evidence is produced suggesting that preoperative CBCT shows the apical foramen to be on average 0.40 mm coronal to its histological position, with a mean absolute difference of 0.48 mm.

• The Research Journal of the Costume Culture
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• v.25 no.3
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• pp.315-326
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• 2017

The purpose of this study is to investigate the design methods and characteristics of papercraft fashion from 2001 to 2015. The study has been conducted through theoretical research and case study. Overall, types of papercraft expressions are classified into the following four categories: narrative papercraft fashion, organic papercraft fashion, variable papercraft fashion, and recycling papercraft fashion. The characteristics and aspects of each type of papercraft is described below. First, narrative papercraft fashion expresses as factual description of the natural environment. These works convey fantastic image by showing fairy tale animals or plants using paper folding or cutting. Second, organic papercraft fashion creates a futuristic shape by expressing organic parts in nature. Also, it often depicts future-oriented images by repeatedly representing organic shapes using uniform patterns in nature. Third, variable papercraft fashion expresses a variety of changing shapes through a flexible design based on the style of wearing. This variation may be accomplished through changeable dress connected to human gestures. Variable papercraft represents play-fulness, which conveys enjoyment to the wearer and the audience. Fourth, recycling papercraft fashion uses paper materials of the past, and recreates them into artworks through handicraft techniques. Recycling papercraft conveys high value added fashion by dissolving the material into pulp.

• Journal of Microbiology
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• v.44 no.3
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• pp.276-283
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• 2006

The thermophilic fungus Thermoascus aurantiacus 179-5 produced large quantities of a glucosidase which preferentially hydrolyzed maltose over starch. Enzyme production was high in submerged fermentation, with a maximal activity of 30 U/ml after 336 h of fermentation. In solid-state fermentation, the activity of the enzyme was 22 U/ml at 144 h in medium containing wheat bran and 5.8 U/ml at 48 h when cassava pulp was used as the culture medium. The enzyme was specific for maltose, very slowly hydrolyzed starch, dextrins (2-7G) and the synthetic substrate (${\alpha}$-PNPG), and did not hydrolyze sucrose. These properties suggest that the enzyme is a type II ${\alpha}$-glucosidase. The optimum temperature of the enzyme was $70^{\circ}C$. In addition, the enzyme was highly thermostable (100% stability for 10 h at $60^{\circ}C$ and a half-life of 15 min at $80^{\circ}C$), and stable within a wide pH range.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.727-733
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• 1997

Autotransplantation is a procedure which transplants teeth from the original position to other positions in the same individual. It is classified surgical reposition by intraalveolar autotransplantation and transalveolar autotransplantation. The prognosis for successful autotransplantation is dependent on a number of factors such as root development, surgical technique, patient's age, endodontic treatment, time and type of splinting, preservation of periodontal ligament and storage medium. The most important factor is preservation of periodontal ligament. The cause of the failure of transplantation include damage of the transplant during removal from deep palatal malposition, poor regeneration of the bone around the transplant and chronic periodontal infection. In case I, Impacted maxillary canine for which surgical exposure and orthodontic treatment was impossisle was transplanted. After 2 weeks, It showed periapical radiolucency and external root resorption. So, endodontic treatment was done. One year later, permanent filling was done with gutta percha. In case II, Transpositioned maxillary central incisor was transplanted after extraction of impacted mesiodens. Pulp vitality was maintained during 5 months without other clinical symptons.

• Restorative Dentistry and Endodontics
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• v.27 no.6
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• pp.622-631
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• 2002

To understand the recent characteristics of the papers published in the Journal of Korean Academy of Conservative Dentistry(JKACD), All the papers in the JKACD of 1992 to 2001 were analyzed. A total of 513 papers were classified according to its type, fold and subject of the study, school and the number of authors, references, and written language. The results were as follows ; 1 According to the type of the paper, 506(98.6%) were original articles, 3(0.6%) were review articles, and 4(0.8%) were case reports. 2. Anual proportion of papers in the fold of operative dentistry was similar to that of endodontics 3. In the field of operative dentistry, esthetic restorative materials and bonding to tooth constituted major subjects of the studies. In the field of endodotics, pulp biology was prominent and canal shaping, endodontic microbiology and canal obturation were steadily reported. 4. According to author's school, similar number of papers were published in the field of operative den tistry and endodontics in general. However, some schools showed preponderances. 5. Most studies were done by two or more authors. Studies published by two authors were most 6. Fifty(9.7%) papers were done in collaboration with workers of the other field. 7. Average number of references cited in the papers was 41.2, including domestic references of 1.8. 40.7% of the papers was shown to cite no domestic papers at all. 8. Twenty-eight(5.5%) papers were written in English, with increasing ratio.

• Restorative Dentistry and Endodontics
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• v.43 no.4
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• pp.42.1-42.7
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• 2018

Objectives: The purpose of this study was to investigate the C-shaped root canal anatomy of mandibular second molars in a Korean population. Materials and Methods: A total of 542 teeth were evaluated using cone-beam computed tomography (CBCT). The canal shapes were classified according to a modified version of Melton's method at the level where the pulp chamber floor became discernible. Results: Of the 542 mandibular second molars, 215 (39.8%) had C-shaped canals, 330 (53%) had 3 canals, 17 (3.3%) had 2 canals, 12 (2.2%) had 4 canals, and 8 (1.7%) had 1 canal. The prevalence of C-shaped canals was 47.8% in females and 28.4% in males. Seventy-seven percent of the C-shaped canals showed a bilateral appearance. The prevalence of C-shaped canals showed no difference according to age or tooth position. Most teeth with a C-shaped canal system presented Melton's type II (45.6%) and type III (32.1%) configurations. Conclusions: There was a high prevalence of C-shaped canals in the mandibular second molars of the Korean population studied. CBCT is expected to be useful for endodontic diagnosis and treatment planning of mandibular second molars.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.188-196
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• 2015

Endodontic management of an immature permanent tooth with dens invaginatus poses a challenge to efficient treatment planning for the clinicians. Because it is difficult to shape, disinfect, and seal the canal space effectively, teeth with complex root canal structures often require particularly extensive and thorough treatment approaches. The purpose of this case report was to share clinical insight from the results of short-term follow-ups after regenerative endodontic treatment with a dens invaginatus. Two immature maxillary lateral incisors with Oehlers type I and III dens invaginatus and infected necrotic pulp were treated using regenerative endodontic procedures. For the type III dens invaginatus case, an unusual approach toward redesigning the complex internal structure was taken, in order to have sufficient infection control and sealing. Cone-beam computed tomography (CBCT) and a surgical operating microscope were used to aid visualization and treatment. As a result, regenerative endodontic treatment appears to be effective for managing immature permanent teeth with complex dens invaginatus, and can lead not only to clinical and radiographic resolution, but also increased thickness of the dentinal walls.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.75-85
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• 1985

This study is intended to find out the influence of Lignosulfonic Acid Type Admixture on compressive, tensile, flexural strength and dispersing action of mortar, and fixation of by-product of pulp industry. 1. The more Pozzolith-84 is added, the larger flow value is. The admixture of lignosulfonic acid type adhere to cement particles and the surface potential of particles is generated. On account of the repulsion among the cement particles, they are dispersed and the mortar get workable, so the production cost of precast product is curtailed and the amount of cement is reduced in a certain workability of mortar. 2. The strength of mortar is greater than plain mortar when P/C added is 0.2 and 0.4%. As time passed the potential energy is reduced and the distance of particles which lignosulfonic acid adhered to get near according as the amount of adhesion is increased. The setting and hardening reaction of morter is occurred in close state, so the strength of mortar is increased a little. The strength of mortar is less than plain mortar when amount P/C added is 0.8%. Pozzolith-84 is mainly composed of lignosulfonic acid and lignin does not influence the hardening of mortar, therefore the remained $SO_3$, $SO_3H$ are the reason of decrease of strength. 3. There is high significance between specific gravity and compressive strength. The larger specific gravity is, the more compressive strength is increased. There is high significance between 7 day's strength and 28 day's strength. The larger compressive strength is, the more tensile and flexural strength are increased. 4. Since Pozzolith-84 is a by-product of pulp industry, by using the Pozzolith-84 admixture the concreate quality is improved. The water pollusion is reduced according to fix by-products in concrete structure.