• Korean Journal of Materials Research
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• v.29 no.9
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• pp.519-524
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• 2019

Spherical $Li_3V_2(PO_4)_3$ (LVP) and carbon-coated LVP with a monoclinic phase for the cathode materials are synthesized by a hydrothermal method using $N_2H_4$ as the reducing agent and saccharose as the carbon source. The results show that single phase monoclinic LVP without impurity phases such as $LiV(P_2O_7)$, $Li(VO)(PO_4)$ and $Li_3(PO_4)$ can be obtained after calcination at $800^{\circ}C$ for 4 h. SEM and TEM images show that the particle sizes are $0.5{\sim}2{\mu}m$ and the thickness of the amorphous carbon layer is approximately 3~4 nm. CV curves for the test cell are recorded in the potential ranges of 3.0~4.3 V and 3.0~4.8 V at a scan rate of $0.01mV\;s^{-1}$ and at room temperature. At potentials between 3.0 and 4.8 V, the third $Li^+$ ions from the carbon-coated LVP can be completely extracted, at voltages close to 4.51 V. The carbon-coated LVP exhibits an initial specific discharge capacity of $118mAh\;g^{-1}$ in the voltage region of 3.0 to 4.3 V at a current rate of 0.2 C. The results indicate that the reducing agent and carbon source can affect the crystal structure and electrochemical properties of the cathode materials.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.505-527
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• 2000

The 3 beagle dogs aged over one and half years and weighed 14 to 16 Kg were utilized in this study. Horizontal furcation defects were induced around 3rd, and 4th premolars bilaterally. BMP-4 in conjunction with EGF and BMP-4 only were applied in the right and left premolars respectively. 1 animal was sacrificed at 2nd week, 4th week, and 8th week, after regenerative surgery respectively. Semi-thin sections using glass-knife were stained with hematoxylin- eosin and trichrome for light microscopic study. The results were as follows : 1 . The long junctional epithelial downgrowth was observed in both area applied with BMP-4 and with BMP-4 and EGF at 2nd week after the surgery. 2 . The extensive regeneration of new bone and cementum was appeared at 4th week and the maturation of bone was observed at 8th week in both area applied with BMP-4 and with BMP-4 and EGF. 3 . The root ankylosis and resorption was presented along the exposed root surface at the coronal 1/3 of defect in the BMP-4 applied site, but it was not shown in the site applied with BMP-4 in conjunction with EGF at the 4th week. At 8th week, the root ankylosis was apparently appeared in the BMP-4 and EGF applied site as well as in the BMP-4 applied site. 4 . The periodontal ligament tissue including Sharpey's fiber inserted into cementum and alveolar bone, was formed along the exposed root surface in the area applied with BMP-4 only, but in the site applied with BMP-4 and EGF, the collagen fiber running parallel to the root surface without Sharpey's fiber, was observed in the periodontal ligament space at 4th and 8th week. Within the above results, BMP-4 had the remarkable capability to regenerate the periodontal tissue and EGF had possibility to prevent from the root ankylosis. Therefore, growth factors including BMP-4 and EGF may have the strong possibility to be utilized in the clinical periodontal treatments.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.179-186
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• 1998

Effects of lead(Pb) and calcium(Ca) on growth responses, accumulation of heavy metals and nitrogen fixation activities of Melilotus suaveolens seedlings were quantitatively analyzed during growing period. Pb contents of the root treated with 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca were 54.1, 90.9 and 26.1 folds higher than that of the control, respectively, at pH 4.2 in 28th days, and heavy metal content of plant increased with increasing of pH and Pb concentration. The melilot plant was classified as a Pb accumulator by higher accumulation of Pb in shoot than that of root. Pb treatments resulted in inhibiton of height and chlorophyll contet, and Ca treatment increased height and chlorophyll content insignificantly at pH 4.2 in 28 days. The plant biomass reduced 49, 60 and 54% at pH 4.2 and 47,53 and 50% at pH 6.5, respectively, by 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca treatment. Specific nitrogen fixation of nodules reduced 68.4% and 46.6% by 100 ppm Pb treatment and 3.7% and 24.9% by 100 ppm Pb added 100 ppm Ca at pH 4.2 and pH 6.5, respectively, so Ca inhibited significantly Pb activity and toxicity in acdic pH. Nodule formation were reduced to 33, 33 and 50% at pH 4.2 and 50, 33 and 38% at pH 6.5 by 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca, respectively.

• Archives of Plastic Surgery
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• v.47 no.6
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• pp.559-566
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• 2020

Background Infraorbital nerve dysfunction is commonly reported after zygomaticomaxillary complex fractures. We evaluated sensory changes in four designated areas (eyelid, nose, zygoma, and lip) innervated by the infraorbital nerve. This evaluation was conducted using the static two-point discrimination test and the vibration threshold test. We assessed the diagnostic significance of the blink reflex in patients with infraorbital nerve dysfunction. Methods This study included 18 patients, all of whom complained of some degree of infraorbital nerve dysfunction preoperatively. A visual analog scale, the infraorbital blink reflex, static two-point discrimination, and the vibration threshold were assessed preoperatively, at 1 month postoperatively (T1), and at a final follow-up that took place at least 4 months postoperatively (T4). The results were analyzed using a multilevel generalized linear mixed model. Results Scores on the visual analog scale significantly improved at T1 and T4. The infraorbital blink reflex significantly improved at T4. Visual analog scale scores improved more rapidly than the infraorbital blink reflex. Two-point discrimination significantly improved in all areas at T4, and the vibration perception threshold significantly improved in the eyelid at T4. Conclusions Recovery of the infraorbital blink reflex reflected the recovery of infraorbital nerve dysfunction. We also determined that the lip tended to recover later than the other areas innervated by the infraorbital nerve.

• Journal of Environmental Health Sciences
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• v.19 no.3
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• pp.29-35
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• 1993

This study was performed to obtain optimal conditions for reduction of color in dye wastewaters using coagulation-sedimentation processes with redox reactions. The reduction of color as well as organic matters variation was observed after coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O and NaOCl. Coagulation-redox reaction was done with the dose of Coagulant and oxidant at various pH values. Redox reaction was done through jar-mixing and aeration. The results of study were as follows: 1. In the coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was heigher at pH 3. With variance of dosage of FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was higher at 250 mg/l. When coagulation-sedimentation using FeSO$_4$ $\cdot$ 7H$_2$O 250 mg/l was added at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 47.6%, 21.3% and 22.1%, respectively. 2. When NaOCI was added at level of 100 ppm in raw wastewater at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 30.2%, 5.5% and 6.2%, respectively. 3. After coagulation-sedimentation processes by addition of FeSO$_4$ $\cdot$ 7H$_2$O, when NaOCl was added at level of 250 mg/l in supernant, color reduction was 47.8% in aeration and 37.5% in jar-mixing. 4. Color reduction by aeration was higher than that by jar-mixing.

• Food Science and Preservation
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• v.31 no.1
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• pp.46-63
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• 2024

This study evaluated the impact of storage temperature on the quality characteristics of texturized vegetable protein (TVP). TVP was prepared by mixing defatted Daewon soybean flour at 80℃, gluten, and corn starch in a 5:3:2 ratio, which was then extruded at a screw speed of 250 rpm and a barrel temperature of 190℃ with moisture addition at 9 rpm. Subsequently, the extruded TVP was vacuum-sealed in polyethylene packaging and stored at -20℃, 0℃, and 4℃ for 9 days. Texture analysis revealed that the curing rate followed 4℃ > 0℃ > -20℃ sequence. No significant color variation was observed across the storage conditions, although water content increased at all temperatures. Notable changes were detected in moisture absorption capacity (%) and solid leaching (%), following the order of -20℃ > 0℃ > 4℃. The turbidity of the solution released during cooking varied, with the highest to the lowest sequence being -20℃ > 4℃ > 0℃, while pH levels remained neutral. Regarding free amino acids, sweetness and textural quality improved with storage across all temperatures, whereas bitterness components diminished at 4℃. The study suggests that refrigerated storage at 4℃ is a viable method for distributing TVP, which was previously distributed only in a frozen and dry state.

• Journal of the Korean Ceramic Society
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• v.34 no.4
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• pp.413-419
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• 1997

The specimens which were prepared from cokes with additions of 0~25 wt% B4C were sintered in Ar atmosphere at 220$0^{\circ}C$. The effects of B4C content on graphitization and oxidation resistance of cokes were investigated. B4C accelerates the graphitization of cokes and at 220$0^{\circ}C$ the degree of graphitization increased from 0.33 which is the value of pure carbon to 0.56, which increased bluk density and porosity. Especially bending strength increased as th graphitization temperature increased. Oxidation resistance property was greatly improved when B4C was added more than 10wt% at 80$0^{\circ}C$ and when B4C was added more than 20wt% at 100$0^{\circ}C$. This was because that the thin layer of B2O3 glass phase on the surface of the composite could be identified to increase the oxidation resistance.

• Journal of the Korean institute of surface engineering
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• v.51 no.4
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• pp.214-217
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• 2018

Stainless steel grade 430 with a composition of Fe-17%Cr was corroded in $Na_2SO_4$ and ($Na_2SO_4+NaCl$) salts at 800 and at $900^{\circ}C$ for up to 20 h. It corroded mainly to $Cr_2O_3$, along with a small amount of $Fe_2O_3$ and $Fe_3O_4$. The formed oxide scales were neither dense nor compact enough owing to their ensuing dissolution into the salt during corrosion, which facilitated internal corrosion. Corrosion occurred faster at $900^{\circ}C$ than $800^{\circ}C$. NaCl in $Na_2SO_4$ aggravated the scale adherence.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.8
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• pp.613-619
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• 1998

Ultrasonic probes of 400kHz, 1MHz were fabricated using PZT-5Z plates. Epoxy was used for backing layer materials onthe plates. Nondestructive Test was carried using these probes. Pulse lobe width of impulse response was reduced 15.4% compare 1MHz with 400kHz and 96.6% compare 3MHz with 400kHz. The attenuation in aluminum was 2.05[dB/m] at 400kHz, 4/91[dB/m] at 1MHz, 7.35[dB/m] at 3HMz. Hole detection error of the first hole was 22.4% at 1HMz, 9.% at 3HMz, The second hole 11.6% at 1HMz, 4.7% at 3HMz. In the result of experiment of the hole detection error and resolution, 3HMz probe was the best among them.

• Journal of Food Hygiene and Safety
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• v.12 no.3
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• pp.200-204
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• 1997

Effects of benzoate (0~0.6 g/$\ell$ ) and sorbate (0~2.0 g/$\ell$) on the growth of Escherichia coli O157:H7 in tryptic soy broth at various pH levels (4~8) and temperatures (4$^{\circ}C$, 37$^{\circ}C$) were investigated. Benzoate and sorbate were inhibited the growth of E. coli O157:H7 up to 12 hours cultivation at 4$^{\circ}C$, and 2.0 g/$\ell$ sorbate was only inhibited during 48 hours cultivation at 37$^{\circ}C$. Among the pH levels tested, pH 4 showed significant inhibitory effect against the E. coli O157:H7 on 4$^{\circ}C$ and at 37$^{\circ}C$, respectively. When used in combination 0.2 g/$\ell$ benzoate and sorbate were completely inhibited the growth of E. coli O157:H7 on pH 4 and at 37$^{\circ}C$. While on pH 5 at 4$^{\circ}C$, all of the concentration tested did not exert any inhibitory effect. The combined effects were retarded more than single treatment of E. coli O157:H7.