• Clinical and Experimental Pediatrics
• /
• 제52권9호
• /
• pp.1048-1052
• /
• 2009

Plastic bronchitis is a rare disease characterized by the recurrent formation of branching mucoid bronchial casts that are large and more cohesive than those that occur in ordinary mucus plugging. Casts may vary in size and can be spontaneously expectorated, but some require bronchoscopy for removal. Plastic bronchitis can therefore present as an acute life-threatening emergency if obstruction of the major airways occurs. Three of 22 reported patients with eosinophilic casts were fatal, with death due to central airway obstruction. Here, we report a child with no history of atopy, allergy, or congenital heart disease who was diagnosed with plastic bronchitis with eosinophilic casts. Although he was administered intravenous (iv) antibiotics; iv corticosteroids; and a vigorous pulmonary toilet regimen, including chest physiotherapy and routine bronchoscopic removal of casts, he had brain death secondary to hypoxic brain damage. Plastic bronchitis can be fatal when casts obstruct the major airways, as in the present case. Clinicians should intervene early if a patient exhibits signs and symptoms consistent with plastic bronchitis.

• Journal of Bio-Environment Control
• /
• 제24권3호
• /
• pp.187-195
• /
• 2015

In this study, a field test of uplift load was carried out using 15 greenhouse foundations fabricated in full scale on a sand soil to examine the uplift capacity of plastic film greenhouse and glasshouse foundations for disasterproof standard. As a result, the maximum uplift capacity of the target greenhouse foundations was shown to be in the range from 11.6kN to 82.4kN according to the differences between the forms and sizes of the foundation. As a result of the examination of the applicability using the field uplift load test result of the theoretical equation proposed for maximum uplift capacity calculation of greenhouse foundations, we found that in general, the conventional theoretical equation for the calculation provided numerical values close to the field test results. However, the soil considered in this study was a sand; thus, in the future, verifying the conventional theoretical equation for the uplift capacity calculation of a cohesive soil would be necessary.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• 제19권5호
• /
• pp.54-63
• /
• 2018

In this study, the stability and economic feasibility of a MSE (Mechanically stability earth) wall with a pre-cast concrete pacing panel was investigated for a standard section of highway. Based on the design criteria, the MSE walls of the panel type were designed considering the load conditions of the highway, such as the dead load of the concrete pavement, traffic load, and impact load of the barrier. The length of the ribbed metal strip was arranged at 0.9H according to the height of the MSE walls. Because the length of the reinforcement was set to 0.9H according to the height of the MSE wall, the external stability governed by the shape of the reinforced soil was not affected by the height increase. The factor of safety (FOS) for the bearing capacity was decreased drastically due to the increase in self-weight according to the height of the MSE wall. As a result of examining the internal stability according to the cohesive gravity method, the FOS of pullout was increased and the FOS of fracture was decreased. As the height of the MSEW wall increases, the horizontal earth pressure acting as an active force and the vertical earth pressure acting as a resistance force are increased together, so that the FOS of the pullout is increased. Because the long-term allowable tensile force of the ribbed metal strip is constant, the FOS of the fracture is decreased by only an increase in the horizontal earth pressure according to the height. The panel type MSE wall was more economical than the block type at all heights. Compared to the concrete retaining wall, it has excellent economic efficiency at a height of 5.0 m or more.

• Journal of the Korean Society for information Management
• /
• 제23권2호
• /
• pp.21-37
• /
• 2006

Based upon the assumption that both theory building and theory use are intertwined to construct a cohesive body of knowledge in the filed, this study attempts to identify the state of theoretical framework by examining the number and the quality of theoretical articles by subfield. Theoretical article is characterized as an incident in which in which the author contributes to the development or the use of theory in his/her own paper. Theoretical incidents were identified by a content analysis of 1,661 articles in four LIS journals from 1984 to 2003. The findings suggest that the four subfields, such as information seeking/use, information retrieval, library management, and scholar communication had great contributions to both theory building and theory use. Also, two research areas such as bibliometrics and professionals are very likely to be theoretical. Further, the analysis of the name of theories used by subfields could give an insight into the understanding of how the theoretical frameworks of each subfield are related.

• Journal of the Korean Operations Research and Management Science Society
• /
• 제41권4호
• /
• pp.55-73
• /
• 2016

Marketing activities play an important role in determining sales performances for B2B companies; however, prior research implies that the effect of marketing activities in the industrial market cannot be inferred from findings in the consumer market due to their differences such as types of customers or products. We further note that B2C companies (i.e. B2B client companies) serve individual consumers, and thus, B2B sales performance can be better understood as consumer market contexts are also taken into account. In this research, we study B2B marketing activities and B2C market contexts, and their effects on B2B sales performance. To this end, we focus on three factors : sales calls conducted by B2B companies, and market commercialization and social interactions in regions where B2C companies operate. Our empirical analyses provide the following results. First, B2B sales performance improves in proportion to sales calls. When sales calls serve as the means to provide product information, they help client companies understand product benefits and make purchases accordingly. Second, B2B sales performance increases as B2C markets become more commercialized, but the effect of sales calls on B2B sales declines. Commercialized markets are more attractive to individual consumers and thus, lead to greater sales in the consumer market. However, the role of sales calls as information sources weakens as B2C companies share product information themselves and develop expertise in commercialized markets. Finally, B2B sales are greater in urban markets compared to suburbs. However, the effect of sales calls on B2B sales increases in suburban markets compared to the urban counterpart. Cohesive social interactions in suburbs hinder information diffusion among B2C companies, which in turn strengthens the role of sales calls as information sources. We theoretically contribute to the B2B marketing literature and managerially suggest strategies to improve B2B sales performance.

• Elastomers and Composites
• /
• 제49권1호
• /
• pp.43-52
• /
• 2014

The effect of nanoclay (Cloisite 20A) on the self-adhesion behavior of uncured brominated-isobutylene-isoprene rubber (BIIR) has been studied. The dispersion state of nanoclay into the rubber matrix was examined by SEM, TEM and XRD analysis. The thermal degradation behavior of the filled and unfilled samples was examined by TGA and improvement in the thermal stability of the nanocomposites occurred based on the weight loss (%) measurements. Also, addition of nanoclay enhanced the cohesive strength of the material by reinforcement action thereby reducing the degree of molecular diffusion across the interface of butyl rubber. However, the average depth of penetration of the inter-diffused chains was still adequate to form entanglement on either side of the interface, and thus offered greater resistance to peeling, resulting in high tack strength measurements. The improvement in tack strength was only achieved at critical nanoclay loading above 8 phr. Contact angle measurement was also made to examine the surface characteristics. There was no significant interfacial property change by employing the nanoclay.

• Journal of the Korean Geotechnical Society
• /
• 제33권3호
• /
• pp.5-15
• /
• 2017

In this study, the liquid and plastic limit tests were conducted on Paju clay with Casagarande method (dynamic) and the fall cone test method (static) to find out the effects of test methods and testers on their values. Six testers, who already have the experience of test, participated. As a results of liquid limit tests, the fall cone test method showed 4% smaller liquid limit compared to the value determined by Casagrande method. As the number of tests increased, the fall cone test method showed less variation between testers and the variation range of level of proficiency was also more stable. In the case of one point method, the liquid limit determined by the fall cone test method varied with smaller range compared to the Casagrande. Consequently, the fall cone test provided more stable liquid limit value than that of Casagrande method. For the results of plastic limit tests, there were no difference between Casagrande method and the fall cone test unlike liquid limit test results. In other words, both methods showed that plastic limit reached the average value as the number of tests increased, and the tendency level of proficiency also showed to get better.

• The Journal of Advanced Prosthodontics
• /
• 제5권4호
• /
• pp.485-493
• /
• 2013

PURPOSE. To evaluate the effects of surface treatments on shear bond strength (SBS) between microwave and conventionally sintered zirconia core/veneers. MATERIALS AND METHODS. 96 disc shaped Noritake Alliance zirconia specimens were fabricated using YenaDent CAM unit and were divided in 2 groups with respect to microwave or conventional methods (n=48/group). Surface roughness (Ra) evaluation was made with a profilometer on randomly selected microwave (n=10) and conventionally sintered (n=10) cores. Specimens were then assessed into 4 subgroups according to surface treatments applied (n=12/group). Groups for microwave (M) and conventionally (C) sintered core specimens were as follows; $M_C$,$C_C$: untreated (control group), $M_1,C_1:Al_2O_3$ sandblasting, $M_2,C_2$:liner, $M_3,C_3:Al_2O_3$ sandblasting followed by liner. Veneer ceramic was fired on zirconia cores and specimens were thermocycled (6000 cycles between $5^{\circ}-55^{\circ}C$). All specimens were subjected to SBS test using a universal testing machine at 0.5 mm/min, failure were evaluated under an optical microscope. Data were statistically analyzed using Shapiro Wilk, Levene, Post-hoc Tukey HSD and Student's t tests, Two-Way-Variance- Analysis and One-Way-Variance-Analysis (${\alpha}$=.05). RESULTS. Conventionally sintered specimens ($1.06{\pm}0.32{\mu}m$) showed rougher surfaces compared to microwave sintered ones ($0.76{\pm}0.32{\mu}m$)(P=.046), however, no correlation was found between SBS and surface roughness (r=-0.109, P=.658). The statistical comparison of the shear bond strengths of $C_3$ and $C_1$ group (P=.015); $C_C$ and $M_C$ group (P=.004) and $C_3$ and $M_3$ group presented statistically higher (P=.005) values. While adhesive failure was not seen in any of the groups, cohesive and combined patterns were seen in all groups. CONCLUSION. Based on the results of this in-vitro study, $Al_2O_{3-}$ sandblasting followed by liner application on conventionally sintered zirconia cores may be preferred to enhance bond strength.

• The Journal of Korean Academy of Prosthodontics
• /
• 제58권4호
• /
• pp.300-305
• /
• 2020

Purpose: The purpose of this study is to compare the shear bond strength of 3D printing denture base resin according to surface treatment of artificial teeth. Materials and methods: 3D printing denture base resin was fabricated as specimens using 3D printer. The experimental group divided the surface treatment of artificial teeth into five groups according to the application of sandblasting and primer (n=10). Shear bond strengths between denture base and artificial teeth were measured by universal testing machine. All measurements were analyzed by one-way ANOVA and Turkey test (α=.05). Fracture mode of each specimen was analyzed. Microscopic evaluation was conducted by using a scanning electron microscope. Results: Unsurfaced treated group represented the lowest value. The primer groups had significantly higher result values (P<.05). Most specimens of the primer groups had cohesive failure. Conclusion: In 3D printing denture base resin group, mechanical and chemical surface treatment of artificial teeth has increased the shear bond strength. Therefore, if dentures are produced using 3D printing, proper mechanical and chemical treatment of artificial teeth is necessary for adhesion of dentures and artificial teeth.

• Journal of Dental Rehabilitation and Applied Science
• /
• 제28권3호
• /
• pp.223-232
• /
• 2012

The purpose of this study was to investigate the effect of various thickness of porcelain on shear bond strength between metal coping and porcelain. So, various thickness of feldspathic porcelain and heat-pressed porcelain were built up and compared. 120 metal cube($4{\times}4{\times}4mm$) specimens were prepared. 60 specimens were applied to feldspathic porcelain and the others were applied to heat-pressed porcelain by 1mm, 1.5mm, 2mm, 2.5mm, 3mm and 3.5mm thickness. The measurement of shear bond strength was performed by Instron universal testing machine. The following results were obtained from this study. 1. As thickness of feldspathic porcelain increases, shear bond strength has decreased. Feldspathic specimens with 1mm porcelain thickness were significantly stronger than other feldspathic subgroups. 2. There was no significant difference of shear bond strength according to porcelain thickness in heat-pressed porcelain group. 3. In comparison between subgroups with same thickness, feldspathic porcelain group had stronger shear bond strength than heat-pressed porcelain. There were significant difference between 1mm and 3mm porcelain thickness group. 4. In almost cases, fracture surface was found on both metal and porcelain surfaces. As thickness of porcelain was increased, metal exposure was decreased.