• International Journal of Vascular Biomedical Engineering
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• 제4권2호
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• pp.7-12
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• 2006

The present study investigated the effects of the osmotic environment on the rheological properties of erythrocytes and their suspensions. In an iso-osmotic medium, erythrocytes forming a biconcave discocyte under resting conditions, exhibited high deformability. In a low-osmotic medium, the deformability of erythrocytes, which swelled and exhibited a spherical shape, significantly decreased at a high shear stress and the high-shear viscosity of the cell suspension was slightly higher than that of normal blood. Hyper-osmotic stress, however, which caused to form echinocytes, decreased cell deformability but exhibited smaller viscosity in low shear rates than iso-osmotic blood viscosity. These results showed a close relation with the aggregability measurements, in that hypertonic blood showed lower aggregability than the hypotonic and isotonic RBC suspensions. These findings indicate that the physicochemical environment has a strong influence on the rheological properties of the erythrocyte and its suspensions.

• 한국조리학회지
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• 제18권5호
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• pp.205-219
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• 2012

본 연구는 저장조건을 달리한 복어육의 기계적 특성과 관능적 특성의 상관관계를 분석하여 복어육의 식품학적 품질특성을 알아내고자 하였다. 시간이 경과함에 따라 VBN이 증가하였으며 이는 부패가 진행되어 색에 대한 평가가 감소하게 되며, 어취가 증가하게 되어 냄새에 대한 평가도가 감소하고, 그에 따라 촉감에 대한 평가 또한 감소하게 된다. 관능적 특성에서는 $4^{\circ}C$에서 8-12시간 저장한 어육, $12^{\circ}C$에서 4-8시간 저장한 어육, $20^{\circ}C$에서 4시간 저장한 어육의 관능적 품질이 가장 우수하다고 나타났다. 복어육의 이화학적, 기계적 특성과 관능적 특성의 상관관계에서 명도가 증가함에 따라 색에 대한 평가는 감소하게 되는데, 기계적인 특성과 관능적 평가에 있어 다른 양상을 나타내었다. 온도가 증가함에 따라 적색도가 감소하게 되어 색에 대한 평가 또한 감소하게 되는 것으로 나타났다. 저장온도에 상관없이 황색도가 증가함에 따라 색에 대한 평가가 감소하였다. 경도는 단단함이 증가 할수록 손으로 느끼는 촉감이 좋다는 결과가 나타났다. 시간이 경과함에 탄력성은 감소하게 되고 촉감에 대한 평가 또한 감소하는 경향을 나타내었다. 시간이 경과함에 따라 검성이 증가하여 촉감에 대한 평가 또한 증가하는 것으로 나타났다.

• 동아시아식생활학회지
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• 제23권5호
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• pp.561-568
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• 2013

This study was conducted to evaluate the quality characteristics of darae (Actinidia arguta) jelly, a snack for elementary school children, prepared with darae extract. To establish the amount of darae extract (0~4%) that could be added to jelly, the physicochemical sensory characteristics and mechanical properties were measured. As the amount of darae extract increased, the values of L and b were decreased, whereas the a value was increased. Sensory evaluation of the sweetness, taste, flavor, texture and overall acceptability of jelly prepared using 2% darae extract resulted in a high score. Among the mechanical properties, by increasing darae extract only the hardness of the extract was significantly decreased. The results of this study suggest that darae extract can be useful in the production of high quality jelly. Thus, it can be served as a substitute for existing high calorie commercial snacks for children.

• 한국식생활문화학회지
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• 제24권2호
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• pp.191-198
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• 2009

The objective of this study was to investigate the effects of different amounts of pumpkin powder on the quality characteristics of hobakpyeon using physicochemical and sensory properties, as well as on its retrogradation rate during storage. As the amount of pumpkin powder increased, the following effects on the quality characteristics were observed: moisture and amylose contents decreased while protein content increased (p<0.05), and in vitro protein digestibility (IVPD) decreased (p<0.05). Levels of slowly digestible starch and resistant starch fractions increased, while the content of rapidly digestible starch decreased. The starch digestion index and rapidly available glucose content also decreased. Among the physical properties, the L-value decreased while the b-value increased (p<0.05). Texture profile analysis revealed that all textural properties except adhesiveness decreased, and presented significant differences in hardness and chewiness (p<0.05). Sensory properties such as color, flavor, and sweetness increased while others such as wetness and chewiness decreased (p<0.05). Effects on the physicochemical properties during refrigerated storage were also compared between the control and 9% hobakpyeon (9%HP). According to the results, moisture content gradually decreased in the 9%HP compared to the control. Amylose content significantly increased in 9%HP whereas no significant changes were observed in the control. In both types of hobakpyeon, IVSD decreased significantly, showing higher values in 9%HP, whereas mechanical hardness increased, showing lower values in 9%HP. The L-value decreased significantly in the 9%HP whereas no significant changes were observed in the control. In conclusion, the above results suggest that hobakpyeon with low IVSD may be obtained by the addition of 9% pumpkin powder, and also showed that pumpkin powder delayed the rate of retrogradation in 9%HP during storage.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1331-1335
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• 2011

We report the results of the characterization of Cu oxide thin films deposited by radio frequency (r.f.) magnetron sputtering at different annealing temperatures. The deposited Cu oxide thin films were investigated by scanning electron microscopy, spectroscopic ellipsometry, X-ray diffraction, atomic force microscopy, Xray photoelectron spectroscopy, and contact angle measurements. The thickness of the films was about 180 nm and the monoclinic CuO phase was detected. The $CuO_2$ and $Cu(OH)_2$ phases were grown as amorphous phase and the ratio of the three phases were independent on the annealing temperature. The surface of Cu oxide films changed from hydrophilic to hydrophobic as the annealing temperature increased. This phenomenon is due to the increase of the surface roughness. The direct optical band gap was also obtained and laid in the range between 2.36 and 3.06 eV.

• 한국식품과학회지
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• 제16권2호
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• pp.201-205
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• 1984

생강전분의 몇 가지 물리화학적 성질을 옥수수 가교 전분과 비교 검토하였다. 생강전분은 아밀로스 함량이 23.5%, 물결합 능력이 99.1%이었고 B형의 X-ray 회절도를 보였다. 생강 전분의 광투과도는 $70^{\circ}C$ 이후에 증가하였고 옥수수 가교 전분의 swelling power와 용해도는 $90^{\circ}C$까지 아주 낮은 값을 보였으며, 알카리에 대하여도 안정하였다. 아밀로그라피에 의한 생강전분 (7%)의 초기 호화온도는 $81.5^{\circ}C$ 이었고, 옥수수 가교전분과 같이 안정한 Paste를 보였다.

• Membrane and Water Treatment
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• 제7권6호
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• pp.539-553
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• 2016

As a novel hydrophobic monomer, polytetrahydrofuran diacrylate (PTMGDA) was synthesized by the esterification reaction between polyethylene tetrahydrofuran (PTMG) and acryloyl chloride (AC). In situ free radical polymerization reaction method was utilized to fabricate poly (vinylidene fluoride) (PVDF)-PTMGDA-poly(ethylene oxide) dimethacrylate (PEGMA) ulrafiltration (UF) membranes. The performances of PVDF-PTMGDA-PEGMA UF membranes in terms of morphologies, mechanical properties, separation properties and hydrophilicities were investigated. The introduction of the PTMGDA-PEGMA dopants not only increased the membranes' pure water flux, but also improved their mechanical properties and the dynamic contact angles. The addition of the PTMGDA/PEGMA dopants led to the formation of the finger-like structure in the membrane bulk. With the increase concentration of PTMGDA/PEGMA dopants, the porosity and the mean effective pore size increased. Those performances were coincide with the physicochemical properties of the casting solutions.

• 한국식품과학회지
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• 제31권1호
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• pp.138-146
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• 1999

한국산 밀 우리, 은파, 올그루, 그루, 탑동 5 품종과 호주산 연질 밀(ASW), 미국산 연질 밀(WW)과 경질 밀(DNS)로 국수를 제조한 후 조리특성, 기계적 및 관능적 조직감 특성을 비교 검토하였으며 밀가루의 이화학적 성질과의 연관성을 살펴보았다. 국수의 조리 손실율은 밀가루의 단백질 함량이 높을수록 낮고, 수분흡수율은 손상전분의 함량이 높을수록 컸다. 측정 방법을 달리한 기계적 특성에서는 견고성, 씹음성, 인장력 등이 경질 밀인 탑동밀과 DNS가 연질 밀보다는 높은 값을 보이고, 외국산 연질 밀인 ASW, WW가 한국산 밀들보다 낮은 값을 나타냈다. 관능적 특성과 기계적 특성과의 상관관계를 맺어본 결과 multi-blade compression shear test가 10% 압착시험이나 반복 압착시험 및 인장력 시험보다도 더 나은 관계를 보였으며, 표면굳기는 multi-blade compression shear test의 면적과 가장 나은 상관관계를 보였고(r=0.76) 내부굳기와 씹음성은 기울기와 잘 연관되었다. 국수의 관능적 특성과 밀가루의 물리화학적 특성과의 상관관계에서는 단백질의 함량이 국수의 조직감에 가장 큰 영향을 미쳤다. 아밀로즈의 함량은 국수의 유연성 및 미끄럼성과 양의 관계를, 표면굳기, 내부굳기, 씹음성과는 음의 관계를 보였다. 삶은 국수의 색도는 외국산 밀(WW, ASW)에 비해 한국산 밀의 국수가 더욱 더 어두운 색을 띄었다. 기호도 검사 결과, 한국산 연질밀인 그루밀이 수입밀인 WW 및 ASW보다 더 선호하는 것으로 나타났다.

• 한국축산식품학회지
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• 제37권5호
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• pp.635-645
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• 2017

In this study, effect of transglutaminase (TGase) addition on physical, water barrier, optical and mechanical properties of mechanically deboned chicken meat protein (MDCM-P) films was investigated. When TGase was added to the films, the thickness increased, but the solubility decreased. Films treated with TGase exhibited higher water vapor permeability than control film (p<0.05). When TGase concentration increased, the $L^*$ values of films decreased, but $a^*$ and $b^*$ values increased. All films showed very good barrier properties against UV light. The highest tensile strength was obtained in MDCM-P films containing 3% TGase (p<0.05). The elongation at break values increased with the TGase concentration increasing from 1 to 3%, but decreased at higher enzyme concentration (p<0.05). The addition of TGase altered molecular organization and intermolecular interaction in the film matrix. TGase treated films showed smoother and ordered surface structure and homogeneous and compact microstructure. The results indicated that TGase use can be an effective approach in improving the solubility and mechanical properties of MDCM-P films.

• Biomaterials and Biomechanics in Bioengineering
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• 제5권1호
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• pp.65-86
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• 2020

As conventional drug delivery system is being improved rapidly by target-based drug delivery system, finding suitable Drug Delivery System (DDS) for new drugs remains a challenge. Although there are many drug delivery vehicles in existence, a significant improvement is required to some DDS such as for local, implant-based treatments used for musculoskeletal infections. Many polymers have been considered for providing the improvement in DDS. Synthetic polymer, for example, has gained popularity for broad-spectrum physicochemical and mechanical properties. This article reviews the biomedical applications of Poly(TriMethylene Carbonate-co-Caprolactone) (PTMCC), which has attracted attention due to its biocompatibility, biodegradability and rubber-like properties. Its synthesis, physical properties, and degradation are also discussed here. Although it is relatively new in biomedical applications, it is readily usable for the fabrication of differing format of DDS of superior mechanical strength and degradation properties. The use of PTMCC is expected to increase in coming years as more is revealed about its potentials.