• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.407.3-408
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• 2002

A portable near infrared (NIR) system which was newly integrated by our lab has been used to develop a non-invasive blood glucose monitoring. The portable NIR system includes a tungsten halogen lamp, a photo diode array type-InGaAs detector, and specialized reflectance fiber optic probes. The shape of probes is composed of two parts. one for illumination into sample and the other for receiving the radiation from sample. Three kinds of probes with different distance between illumination and receiving part. such as 0.03. 0.1. and 0.5mm, were investigated for optimization. (omitted)

• 대한전기학회논문지
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• 제38권4호
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• pp.292-297
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• 1989

To achieve fiber/resin reinforced composites with high quality (void-free, uniform compaction), a basic understanding of the principal factors related to a thermal cycle to cure the matrix and a pressure to compact the system is necessary. In this paper, some dielectric and mechanical properties of glass cloth reinforced epoxy composites are measured as a function of fabrication conditions, where the time that the pressure is applied to the sample during the cure process is controlled. Both the tensile strength and frequency characteristics of the sample are improved significantly when the pressure is applied at the start point of gelling.

• 한국초지조사료학회지
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• 제29권1호
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• pp.31-36
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• 2009

본 연구는 청예용 사초의 질을 신속하고 정확하게 측정할 수 있는 대안을 모색하기 위하여수행하였다. 근적외선분광분석법을 이용한 사초의 분석가능성을 타진하기 위해 2002년부터 2007년에 거쳐 생산된 각종 사초 258점을 시료로 사용하였다. 즉 시료는 조단백질, 조섬유, NDF, ADF 그리고 건물소화율을 분석하였으며, 또한 NIR System으로 $400{\sim}2,400nm$ 사이의 파장을 얻었다. 그리고 파장과 습식분석치를 이용하여 중회귀식을 만들고 이것을 사용하여 미지의 시료를 분석할 수 있는가를 검증하였다. 근적외선 분석법의 중요한 지표인 결정계수 $r^2$와 표준오차이며 본 실험의 결과 검증식의 $r^2$는 CP(crude protein), CF(crude fiber), ADF (acid detergent fiber), NDF (neutral detergent fiber) 그리고 IVTD(in vitro true digestibility)에서 각 각 0.70, 0.86, 0.94, 0.94 그리고 0.89였다. 검량식은 그 값이 0.47, 0.39, 0.89, 0.90 그리고 0.61이었다. 본 실험 결과 근적외선분광법에 의한 청예사료 질평가가 가능하며 특히 조섬유, ADF 그리고 진정인비트로 소화율 (IVTD)에서 유효할 것으로 나타났다. 그러나 보다 정확한 결과를 얻기 위해서는 시료는 한국사초의 대표성을 갖는 것을 수집하여 사용해야 할 것이다. 앞으로 더 많은 시료를 추가하면 모든 사초를 분석할 강고한 검량식이 작성될 수 있을 것으로 기대된다.

• 한국의류학회지
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• 제21권1호
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• pp.206-216
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• 1997

The purpose of this study was to determine the pore size distributions (PSDs) of polyester woven fabrics by using liquid extraction method. Three types of PSDs-percent PSD, PSD per unit area of sample and PSD per unit weight of sample-were evaluated. Plain, twill and satin polyester fabrics with various fabric counts were used as specimens. Results showed that the interyarn PSDs reflected the fabric characteristics such as the fabric count and the weave type and the intrayarn PSDs reflected the thread characteristics such as the number of fibers, the fiber diameter, the thread diameter and the thread twist. Of three types of PSDs, the PSD per unit area of sample best reflect fabric and thread characteritics. As the fabric count decreased, rc increased and interyarn pore volume increased. The PSDs were skewed to the small pore sizes and the pore volumes decreased in the order of plain> twill> satin. As the number of fibers, the fiber diameter and the thread twist decreased, the intrayarn pore volumes were increased.

• Food Science and Biotechnology
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• 제14권2호
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• pp.238-241
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• 2005

Aroma-active compounds were evaluated from salt-fermented anchovy sauce by solid phase microextraction-gas chromatography-olfactometry (SPME-GC-O) based on sample dilution analysis (SDA). SPME extract from carboxen/polydimethylsiloxane (CAR/PDMS) fiber was the most similar to the original odor of salt-fermented anchovy sauce used for this experiment, followed by divinylbenzene/CAR/PDMS (DVB/CAR/PDMS) fiber. Because salt-fermented anchovy sauce contains 23% NaCl, NaCl concentration of diluent was considered when salt-fermented anchovy sauce was serially diluted. Linear relationship between GC response and sample concentration was observed when diluted with 23% NaCl solution, whereas not observed when diluted with deodorized distilled water. Eleven and 16 aroma-active compounds were detected by SPME-GC-O based on SDA using CAR/PDMS and DVB/CAR/PDMS fibers, respectively. Butanoic acid and 3-methyl butanoic acid showed the highest ${\log}_2SD$ factors for CAR/PDMS and DVB/CAR/PDMS fibers. Dimethyl trisulfide, methional, trimethyl amine, 1-penten-3-ol, and acetic acid were also detected as potent aroma-active compounds.

• 한국축산식품학회지
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• 제35권3호
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• pp.307-314
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• 2015

In this study, we evaluated the effects of dietary fiber extracted from Algelica keiskei Koidz on the chemical composition, cooking characteristics, and sensory properties of chicken patties. The chicken patties with Algelica keiskei Koidz dietary fiber had significantly higher moisture and ash content, and yellowness than the control sample (p<0.05). Energy value, cooking loss, reduction in diameter, reduction in thickness, lightness, redness, hardness, cohesiveness, gumminess, and chewiness of the control samples was significantly higher than chicken patties with Algelica keiskei Koidz dietary fiber (p<0.05). The sensory evaluation indicated that the greatest overall acceptability in chicken patties was achieved at Algelica keiskei Koidz dietary fiber levels of 1% and 2%. Chicken patties supplemented with 2% Algelica keiskei Koidz dietary fiber had improved quality characteristics.

• 방사선산업학회지
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• 제9권1호
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• pp.15-20
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• 2015

Carbon fiber has received much attention owing to its properties, including a large surface-to-volume ratio, chemical and thermal stability, high thermal and electrical conductivity, and high mechanical strengths. In particular, magnetic nanopowder dispersed carbon fiber has been attractive in technological applications such as the electrochemical capacitor and electromagnetic wave shielding. In this study, the nickel-oxide-nanoparticle dispersed polyacrylonitrile (PAN) fibers were prepared through an electrospinning method. Electron beam irradiation was carried out with a 2.5 MeV beam energy to stabilize the materials. The samples were then heat-treated for stabilization and carbonization. The nanofiber surface was analyzed using a field emission scanning electron microscope (FE-SEM). The crystal structures of the carbon matrix and nickel nanopowders were analysed using X-ray diffraction (XRD). In addition, the magnetic and electrical properties were analyzed using a vibrating sample magnetometer (VSM) and 4 point probe. As the irradiation dose increases, the density of the carbon fiber was increased. In addition, the electrical properties of the carbon fiber improved through electron beam irradiation. This is because the amorphous region of the carbon fiber decreases. This electron beam effect of PAN fibers containing nickel nanoparticles confirmed their potential as a high performance carbon material for various applications.

• 한국광학회:학술대회논문집
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• 한국광학회 2002년도 제13회 정기총회 및 2002년도 동계학술발표회
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• pp.42-43
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• 2002

• Animal Bioscience
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• 제37권7호
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• pp.1196-1203
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• 2024

Objective: A study was conducted to quantify the performance differences of the near-infrared spectroscopy (NIRS) calibration models developed with different degrees of hay sample preparations. Methods: A total of 227 imported alfalfa (Medicago sativa L.) and another 360 imported timothy (Phleum pratense L.) hay samples were used to develop calibration models for nutrient value parameters such as moisture, neutral detergent fiber, acid detergent fiber, crude protein, and in vitro dry matter digestibility. Spectral data of hay samples prepared by milling into 1-mm particle size or unground were separately regressed against the wet chemistry results of the abovementioned parameters. Results: The performance of the developed NIRS calibration models was evaluated based on R², standard error, and ratio percentage deviation (RPD). The models developed with ground hay were more robust and accurate than those with unground hay based on calibration model performance indexes such as R² (coefficient of determination), standard error, and RPD. Although the R² of calibration models was mainly greater than 0.90 across the feed value indexes, the R² of cross-validations was much lower. The R² of cross-validation varies depending on feed value indexes, which ranged from 0.61 to 0.81 in alfalfa, and from 0.62 to 0.95 in timothy. Estimation of feed values in imported hay can be achievable by the calibrated NIRS. However, the NIRS calibration models must be improved by including a broader range of imported hay samples in the modeling. Conclusion: Although the analysis accuracy of NIRS was substantially higher when calibration models were developed with ground samples, less sample preparation will be more advantageous for achieving rapid delivery of hay sample analysis results. Therefore, further research warrants investigating the level of sample preparations compromising analysis accuracy by NIRS.

• Carbon letters
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• 제2권3_4호
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• pp.170-175
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• 2001

A petroleum-based isotropic pitch fiber spun by melt-blown method was oxidized in air flow at various conditions. The oxidized pitch fiber obtained was tested for its infusibility and its elemental composition during the process of stabilization. The structural changes were traced by using solvent solubility, FT-IR spectroscopy, and elemental analysis. The samples showed a gradual increase in weight with increasing the oxidization temperature. The weight gain of sample oxidized at $320^{\circ}C$ for 10 min was about 4.5%. The concentration of the pyridine and toluene soluble fraction decreased with an increase in stabilization temperatures. The oxygen uptaken in the stabilization process converted aliphatic side chains into the carbonyl groups. As stabilization proceeded, the more ether and carboxylic acid groups were formed through the oxidations of aldehyde and primary alcohol, and then the carboxylic acid was dehydrated to be aromatic anhydride.