• 대한치과보철학회지
• /
• 제45권6호
• /
• pp.724-734
• /
• 2007

Statement of problem. Translucency and masking effect of provisional crown and fixed partial denture materials is an important esthetic consideration. But, provisional resin materials differ substantially in their ability to mask underlying colors. Purpose. The purpose of this study was to evaluate the translucency differences of provisional resin materials at various thicknesses and the correlation between the translucency and the masking efficiency. Material and methods. Two polymethyl methacrylate resins (Jet Tooth Shade, Alike) and three resin composites (Protemp 3 Garant, Luxatemp and Revotek LC) were used. Specimens (n=6) were fabricated from each material in 0.3, 0.5, 0.8, 1.0, 1.5, 2.0 and 3.0 mm thickness. The CIELAB parameters of each specimens were measured using a spectrophotometer. The translucency parameter (TP) values and the masking effect $({\Delta}ME^*{_{ab}})$ values were computed and all data were statistically analyzed by one-way ANOVA and the multiple comparisons Scheffe test. The correlation between the thickness and the TP values and the correlation between the thickness and the ${\Delta}ME^*{_{ab}}$ values were also evaluated by correlation analysis and regression analysis. Results. The TP values and the ${\Delta}ME^*{_{ab}}$ values were significantly related to the thickness in all specimens. The TP values were more sensitive to the change of thickness than the ${\Delta}ME^*{_{ab}}$ values. The order of the translucency by brand was different from the order of the masking effect by brand in all thickness groups. Conclusion. Within the limitations of this study, the translucency and masking effect of the provisional resin materials investigated were significantly related to their thickness. The masking effect of provisional resin was correlated with the translucency parameter, but the order of the masking effect by brand was different from the order of the translucency parameter.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.469-470
• /
• 2008

We have studied electro-optic characteristics as a function of splay elastic constants ($K_{11}$) in the fringe-field switching (FFS) mode using the LC with positive dielectric anisotropy. When $K_{11}$ is increased from 7.7pN to 11.7pN, a maximum transmittance is slightly increased and rising time become a little bit fast. However, operating voltage and threshold voltage is independent. In opposition to rising time, decay time is not affected by $K_{11}$. We already know that $K_{11}$ affects tilt angle of liquid crystals. Therefore, on the occasion of high $K_{11}$, liquid crystals are mainly affected by twist deformation because the higher $K_{11}$, the less tilt angle. In the FFS device, high $K_{11}$ is favorable to reduce tilt angle in on state and thus improve rising response time.

• The Plant Pathology Journal
• /
• 제40권3호
• /
• pp.261-271
• /
• 2024

Sulfur is one of the inorganic elements used by plants to develop and produce phytoalexin to resist certain diseases. This study reported a method for preparing a material for plant disease resistance. Sulfur nanoparticles (SNPs) stabilized in the chitosan-Cu²⁺ (CS-Cu²⁺) complex were synthesized by hydrolysis of Na₂S₂O₃ in an acidic medium. The obtained SNPs/CS-Cu²⁺ complex consisting of 0.32% S, 4% CS, and 0.7% Cu (w/v), contained SNPs with an average size of ~28 nm as measured by transmission electron microscopy images. The X-ray diffraction pattern of the SNPs/CS-Cu²⁺ complex showed that SNPs had orthorhombic crystal structures. Interaction between SNPs and the CS-Cu²⁺ complex was also investigated by ultraviolet-visible. Results in vitro nematicidal effect of materials against Meloidogyne incognita showed that SNPs/CS-Cu²⁺ complex was more effective in killing second-stage juveniles (J2) nematodes and inhibiting egg hatching than that of CS and CS-Cu²⁺ complex. The values of LC₅₀ in killing J2 nematodes and EC₅₀ in inhibiting egg hatching of SNPs/CS-Cu²⁺ complex were 75 and 51 mg/l, respectively. These values were lower than those of CS and the CS-Cu²⁺ complex. The test results on the nematicidal effect against M. incognita on coffee pots showed that the SNPs/CS-Cu²⁺ complex was 100% effective at a concentration of 150 mg/l. Therefore, the SNPs/CS-Cu²⁺ complex could be considered as a biochemical material with potential for agricultural applications to control root-knot nematodes.

• Bulletin of the Korean Chemical Society
• /
• 제33권10호
• /
• pp.3233-3240
• /
• 2012

We demonstrated the combined applications of online protein digestion using trypsin immobilized enzyme reactor (IMER) and dual tandem mass spectrometry with collisionally activated dissociation (CAD) and electron transfer dissociation (ETD) for tryptic peptides eluted through the trypsin-IMER. For the trypsin-IMER, the organic and inorganic hybrid monolithic material was used. By employing the trypsin-IMER, the long digestion time could be saved with little or no sacrifice of the digestion efficiency, which was demonstrated for standard protein samples. For three model proteins (cytochrome c, carbonic anhydrase, and bovine serum albumin), the tryptic peptides digested by the IMER were analyzed using LC-MS/MS with the dual application of CAD and ETD. As previously shown by others, the dual application of CAD and ETD increased the sequence coverage in comparison with CAD application only. In particular, ETD was very useful for the analysis of highly-protontated peptide cations, e.g., ${\geq}3+$. The combination approach provided the advantages of both trypsin-IMER and CAD/ETD dual tandem mass spectrometry applications, which are rapid digestion (i.e., 10 min), good digestion efficiency, online coupling of trypsin-IMER and liquid chromatography, and high sequence coverage.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.1132-1136
• /
• 2004

In this paper, we intend to make FFS mode cell with LC alignment used non-rubbing method, ion beam alignment method on the a-C:H thin film, to analyze electro-optical characteristics in this cell. We studied on the suitable inorganic thin film for FFS-LCD and the aligning capabilities of nematic liquid crystal (NLC) using the new alignment material of a-C:H thin film as working gas at rf bias condition. A high pretilt angle of about 5$^{\circ}$ by ion beam(IB) exposure on the a-C:H thin film surface was measured. An excellent voltage-transmittance (V-T) and response time curve of the ion-beam-aligned FFS-LCD was observed with oblique ion beam exposure on the DLC thin films.

• Carbon letters
• /
• 제26권
• /
• pp.11-17
• /
• 2018

Milled carbon fiber (mCF) was prepared by a ball milling process, and X-ray diffraction (XRD) diffractograms were obtained by a $2{\theta}$ continuous scanning analysis to study mCF crystallinity as a function of milling time. The raw material for the mCF was polyacrylonitrile-based carbon fiber (T700). As the milling time increased, the mean particle size of the mCF consistently decreased, reaching $1.826{\mu}m$ at a milling time of 18 h. The XRD analysis showed that, as the milling time increased, the fraction of the crystalline carbon decreased, while the fraction of the amorphous carbon increased. The (002) peak became asymmetric before and after milling as the left side of the peak showed an increasingly gentle slope. For analysis, the asymmetric (002) peak was deconvoluted into two peaks, less-developed crystalline carbon (LDCC) and more-developed crystalline carbon. In both peaks, Lc decreased and $d_{002}$ increased, but no significant change was observed after 6 h of milling time. In addition, the fraction of LDCC increased. As the milling continued, the mCF became more amorphous, possibly due to damage to the crystal lattices by the milling.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1529-1532
• /
• 2006

Depending on the optical design method, a novel dual-mode transflective LCD with proper LC material and optical films was developed. The design increased the optical transmittance and the reflectivity of dual-mode transflective LCDs with the proper parameters of cell gap, alignment layer and optical films. These parameters were evaluated by computer simulation. The simulation results also revealed that the transmissive and reflective states presented similar performance in the transflective LCDs.

• Transactions on Electrical and Electronic Materials
• /
• 제4권2호
• /
• pp.5-9
• /
• 2003

The liquid crystal (LC) aligning capabilities by the washing processes after rubbing on the two kinds of the rubbed polyimide (Pl) surface were studied. The polar anchoring energy of 4-n-pentyl-4'-cyanobiphenyl (5CB) increased with the rubbing strength RS on the two kinds of the rubbed PI surface. The polar anchoring energy of 5CB on the rubbed PI surface with alkyl side chains is larger than the rubbed PI surface with CONH moiety. Also, the surface ordering of 5CB on the rubbed PI surface with alkyl side chains is larger than the rubbed PI surface with CONH moiety. Therefore, the surface ordering of 5CB strongly depends on the polymers and washing process.

• Journal of Yeungnam Medical Science
• /
• 제37권3호
• /
• pp.217-225
• /
• 2020

Background: This study was performed to provide a long-term bacterial seal through the formation of reparative dentin bridge, calcium silicate-based pulp capping materials have been used at sites of pulpal exposure. The aim of this study was to evaluate the mineralization-inducing potentials of calcium silicate-based pulp capping materials (ProRoot MTA [PR], Biodentine [BD], and TheraCal LC [TC]) in human dental pulp cells (HDPCs). Methods: Specimens of test materials were placed in deionized water for various incubation times to measure the pH variation and the concentration of calcium released. The morphology of HDPCs cultured on the specimens was examined using a confocal laser scanning microscope (CLSM). Alizarin red S staining and alkaline phosphatase assays were used to evaluate mineralization-inducing potentials of the capping materials. Results: BD showed the highest calcium release in all test periods, followed by PR and TC. (p<0.05). All experimental groups showed high alkalinity after 1 day, except at 14 days. BD showed the highest cell viability compared with PR and TC after 1 and 3 days, while TC showed the lowest value (p<0.05). The CLSM analysis showed that cells were well adhered and expressed actin filaments for all pulp capping materials. Mineralization by PR and BD groups was higher than that by TC group based on alizarin red S staining. BD showed significantly higher alkaline phosphatase activity than PR and TC, while TC showed the lowest value (p<0.05). Conclusion: Within the limitations of the in vitro study, BD had higher mineralization-inducing potential than PR and TC.

• Transactions on Electrical and Electronic Materials
• /
• 제4권1호
• /
• pp.21-23
• /
• 2003

The washing effects on pretilt angle generation in a nematic liquid crystal (NLC), 4-n-pentyl-4'-cyanobiphenyl (5CB) on a rubbed polyimide (PI) surface with trifluoromethyl moiety have been successfully studied. The pretilt angle of 5CB is increased by the washing process on the rubbed PI surface. The surface tension on the rubbed PI surface increases with the rubbing strength RS and then saturated above RS: 150 mm. The pretilt angle of 5CB for all washing processes on the rubbed PI surface decreases with the surface tension. We have found that the pretilt angle of 5CB on the rubbed PI surface may be attributed van der walls (VDW) dispersion interaction between the LC molecules and the polymer surfaces having trifluoromethyl moieties.