• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.35 no.1
• /
• pp.72-79
• /
• 2022

Piezoelectric energy harvesting technologies, which can be used to convert the electricity from the mechanical energy, have been developed in order to assist or power the wearable electronics. To realize non-toxic and biocompatible electronics, the lead-free (Ba_0.85Ca_0.15)(Ti_0.90Zr_0.10)O₃ (BCTZ) nanoparticles (NPs) are being studied with a great attention as flexible energy harvesting device. Herein, piezoelectric hybrid nanocomposites were fabricated using BCTZ NPs-embedded poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] matrix to improve the performance of flexible energy harvester. Output performance of the fabricated energy device was investigated by the well-optimized measurement system during the periodically bending and releasing motions. The generated open-circuit voltage and the short-circuit current of the piezoelectric hybrid nanocomposite-based energy harvester reached up to ~15 V and ~1.1 ㎂, respectively; moreover, the instantaneous power of 3.5 ㎼ is determined from load voltage and current at the external load of 20 MΩ. This research is expected to cultivate a new approach to high-performance wearable self-powering electronics.

• Korean Journal of Food Science and Technology
• /
• v.45 no.1
• /
• pp.13-19
• /
• 2013

This study was carried out to find the optimal conditions for red cabbage seed sprouts in terms of their physicochemical and sensory qualities by electron-beam irradiation, cultivation and storage using the response surface methodology (RSM). Moisture content ($R^2$=0.9638) was affected by irradiation dose and cultivation time. Total phenolics content ($R^2$=0.9117) was mainly affected by irradiation dose, but carotenoid content ($R^2$=0.8338) was affected in the order of irradiation dose, cultivation time and storage time. Sensory properties were also affected by irradiation dose, and thus scores decreased as irradiation dose increased. The optimum conditions estimated by superimposing total phenolics content and overall acceptance were 2.2-3.8 kGy of the irradiation dose, 3.0-4.0 days of cultivation and 2.0-3.0 days of storage.

• Korean Journal of Materials Research
• /
• v.31 no.11
• /
• pp.649-656
• /
• 2021

K_0.5Bi_0.5TiO₃ (KBT) thin films were prepared by sol-gel processing for future use in piezoelectric generators. It is believed that the annealing temperature of films plays an important role in the output performance of piezoelectric generators. KBT films prepared on Ni substrates were annealed at 500 ~ 700 ℃. Tetragonal KBT films were formed after annealing process. As the annealing temperature increased, the grain size of KBT films increased. KBT thin films show piezoelectric constant (d₃₃) from 23 to 41 pC/N. The increase of grain size in KBT films brought about output voltage and current in the KBT generators. Also, the increase in the displacement of specimens during bending test resulted in increases in output voltage and current. Although KBT generators showed lower output power than those of generators prepared using NBT films, as reported previously, the KBT films prepared by sol-gel method show applicability as piezoelectric thin films for lead-free nano-generators, along with NBT films.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.25 no.3
• /
• pp.205-210
• /
• 2005

This study was conducted from March 21 to July 9 in 2004 at JeJu Island to investigate the effect of different particle sizes (0.3-0.5, 0.5-0.8, 0.8-1.0, 1.0-1.5 and 1.5-2.0mm) on creeping bentgrass vegetation. The results obtained were summarized as follows; plant height became shorter as particle size was increased from 0.3-0.5 to 1.5-2.0 n. Root length, Minolta SPAD-502 chlorophyll reading value, leave and root weight were directly proportional plant height response. Degree of land cover and density of creeping bentgrass decreased as the particle size was increased from 0.3-0.5 to 1.5-2.0nm, and degree land cover and density of weed increased. The number of weed species were increased as the sand particle size was increased. Then ranking of the dominant weeds were Portulaca oleracea, Trifolium repens and Cyperus amuricus (at 0.3-0.5 and 0.5-0.8mm particle size), Trifolium repens, Portulaca oleracea and Polygonum hydropiper (at 0.8-1.0mm particle size), Portulaca oleracea, Polygonum hydropiper and Poa annua (at 1.5-2.0mm particle size). Based on the these findings, the optimum sand particle size for growth of creeping bentgrass seems to be about 0.3-0.5m in volcanic ash soils of Jeju island.

• Korean Journal of Clinical Laboratory Science
• /
• v.40 no.1
• /
• pp.6-17
• /
• 2008

From the total 116,429 clinical specimens submitted to "C" hospital from January 2005 to December 2006, 2,195 strains of streptococci were isolated. Twenty four species of Streptococcus were identified with 0.1~19.8% isolation frequencies, of which S. pneumoniae was 19.8%, S. agalactiae 16.2%, S. anginosus 9.8%, S. constellatus 5.0%, S. oralis 3.9%, S. mitis 3.3%, S. pyogenes 2.7%, S. salivarius subsp. salivarius 2.2%, S. sanguinis 1.9%. For S. pneumoniae, clinical specimens showing over 9.0% isolation rate were 82.8% in sputum, 9.2% in blood, and for Streptococcus species other than S. pneumoniae, 18.0% in sputum, 16.0% in urine and 9.7% in blood. The antimicrobial agents that showed over 90.0% susceptibility were cefotaxime, gatilfloxacin, imipenem, levofloxacin, linezolid, moxifloxacin, rifampin and sporfloxacin in S. pneumoniae, ampicillin, cefotaxime, cetriaxone, levofloxacin, linezolid, penicillin, quinupristin/dalfopristin and vancomycin in S. agalactiae, chloramphenicol, clindamycin, levofloxacin and vancomycin in S. anginosus, levofloxacin, vancomycin in S. constellatus subsp. constellatus, vancomycin in S. oralis, vancomycin in S. mitis, chloramphenicol, clindamycin, levofloxacin, quinupristin/dalfopristin and vancomycin in S. pyogenes, chloramphenicol, levofloxacin and vancomycin in S. salivarius subsp. salivarius, chloramphenicol, levofloxacin and vancomycin in S. bovis II, chloramphenicol, levofloxacin, quinupristin/dalfopristin and vancomycin in S. dysgalactiae subsp. dysgalactiae, levofloxacin, chloramphenicol and vancomycin in the whole group of 10 Streptococcus spp. other than Streptococcus pneumoniae.

• Journal of Food Hygiene and Safety
• /
• v.21 no.2
• /
• pp.113-117
• /
• 2006

New nonspecific immunostimulators (Koko enterprise Co., Ltd., Korea) were evaluated for its effectiveness as a nonspecific immunostimulator in pigs. The effects of new nonspecific immunostimulators were determined by analysis of cytokines using ELISA and blood-chemistry. IFN-r which is one of the cell mediated immune cytokines significantly increased in DIR-vitamineral 0.2% group posttreatment 4 weeks and was significantly higher IMF 0.2%, DIR-vita 0.1% and DIR-vitamineral 0.2% groups than control group in 3 months. DIR-vitamineral 0.2% had a most strong effectiveness as a nonspecific immunostimulator in our treatment materials in pigs. IMF 0.2% and DIR-vita 0.1% were seen that there had effectiveness of a nonspecific immunostimulator in posttreatment 3 months. IgG IgM and Total Ig which were humoral immune globulins, were not significantly changed in posttreatment 4 weeks and 3 months. In conclusion, this study has demonstrated that new nonspecific immunostimulators had an immunostimulatory effect on pigs through cell mediated immune response.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.98-100
• /
• 2008

A series of new channel materials using triisopropylsilylethynyl anthracene(TIPSAN) derivatives are synthesized by well known reaction. The TIPSAN derivatives exhibit an excellent field-effect mobility with hole mobility as high as 0.1 cm2V-1s-1 by solution-process and slip stack structure of core and end groups with short $\pi-\pi$ stacking distance of $3.525{\sim}3.485\;{\AA}$ by single crystal structures.

• Journal of the Korean Dietetic Association
• /
• v.14 no.2
• /
• pp.139-151
• /
• 2008

Presently, media for sanitation education consisting of a sanitation manual and a CD-ROM intended for restaurant employers and employees was developed and evaluated. The sanitation manual consisted of five principles: prevention of foodborne illness, personal hygiene, control of food production, instrument and equipment cleaning and sanitation, and management of environmental sanitation. The CD-ROM was composed of animations detailed real-life examples of Salmonella, Staphylococcus aureus, and Norovirus foodborned illness outbreaks; slides summarizing the five principles of the manual; and a poster entitled You can prevent foodborne illness listing and describing the principles. A 15 question evaluation survey was developed to gauge the efficacy of the animations. The survey was divided into five sections on comprehension of the instructions, content organization concerning understanding, content organization concerning the information presented, content organization concerning retention of interest (concentration), and recommendations concerning concentration. Ranked on a 5-point scale the survey produced a mean value of 3.80$\pm$0.39 and individual scores of 3.92$\pm$0.45 (learning instruction), 3.86$\pm$0.48 (understanding), 3.82$\pm$0.52 (information), 3.75$\pm$0.49 (concentration), and 3.67$\pm$0.58 (concentration-recommendation). Overall, evaluation results of the animation were good and easy to understand, with only a few respondents electing to watch the animations more than once. In terms of continuous and recurring education, sanitation training programs should be easy to learn and contain sufficient and specific examples of the importance of sanitation in achieving food safety.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.3
• /
• pp.411-420
• /
• 2016

The objective of this study was to determine the effect of drinking water containing trimethyl glycine or ascorbic acid on growth performance and blood parameter profiles of duck exposed to scorching heat stress. A total of 480 ducks were randomly assigned to the following eight experiment groups for 42 days : control group C with general water, treatment group 1 (T1) with drinking water containing 100 ppm ascorbic acid, treatment group 2 (T2) with drinking water containing 200 ppm ascorbic acid, treatment group 3 (T3) with drinking water containing 300 ppm ascorbic acid, treatment group 4 (T4) with drinking water containing 400 ppm trimethyl glycine, treatment group 5 (T5) with drinking water containing 800 ppm trimethyl glycine, treatment group 6 (T6) with drinking water containing 1,200 ppm trimethyl glycine, treatment group 7 (T7) with electrolytes of KCl (0.5%) + $NaHCO_3$ (1.0%)+NaCl (0.5%). Our results revealed that the body weights and feed intakes of treatment groups, especially T3 and T6, were increased compared to the control group, where as the feed conversion ratios of treatment groups were decreased (p<0.05). Blood levels of total cholesterol, triglyceride, LDL-C, glucose, AST, ALT and pH in treatment groups were lower compared to those in the control group (p<0.05). Blood levels of red blood cell, platelets profiles, electrolyte and gas in treatment groups were higher compared to those of the control group (p<0.05).

• Toxicological Research
• /
• v.21 no.2
• /
• pp.161-165
• /
• 2005

Bisphenol A (SPA), a environmental endocrine disruptor, is considered to bind to estrogen receptors and to regulate the expressions of estrogen responsive genes. This study was to evaluate the effect of SPA administration on body weight, sex ratio and litter size on 18 days in prenatal periods, the effect of reproductive organ weight and blood hematological values on 24 days postpartum in pregnant mice. The female mice was administrated to low doses of SPA (0, 0.05, 0.5 and 5.0 mg/kg B.W.) by intraperitoneal injection in gestation days $0\~15$ with 5 times at 3 days interval. The maternal body weight, litter size and sex ratios were similar to in all experimental groups, but body weights of male and female offspring was significantly lower in 5.0mg SPA group when compared to any other groups (P<0.05). No treatment-related effects on body weight, ovary weight and blood hematological values were observed in dams on 24 days after delivery. The uterine weight in 5.0mg SPA group was slightly higher than those of any other groups, but not significantly difference. The histological evaluation of ovary in dam mice on 24 days after dilivery was not difference in all experimental groups, but the endometriosis of uterus in dam mice were significantly increased in 0.5mg SPA group when compared to control group. These results indicates that low concentration of SPA should not be considered as a selective reproductive toxicant.