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Free-standing carbon nanotube films or buckypaper can provide a significant platform to develop practical applications of nanocarbon materials. For this research, buckypaper with high thermal conductivity (20 W/m K) and large surface area (350 m2/g) was mass produced in-house to investigate for use in lightweight thermal management devices. Floating catalyst chemical vapor deposition carbon nanotube sheets were also studied in this work. We introduced two manufacturing techniques to use the sheets for heat dissipation: (1) printing conductive composite ink on the sheets to make lightweight thermal devices, such as heat sinks and (2) assembling the sheets directly into 3D structures that were mounted on the back of heat-generating devices. These manufacturing techniques resulted in extremely lightweight, high-performance heat dissipation devices compared with other heat sink materials.

Technologies to monitor microenvironmental conditions and its spatial distribution are in high demand, yet remain unmet need. Herein, photonic microsensors are designed in a capsule format that can be injected, suspended, and implanted in any target volume. Colorimetric sensors are loaded in the core of microcapsules by assembling core-shell colloids into crystallites through the depletion attraction. The shells of the colloids are made of a temperature-responsive hydrogel, which enables the crystallites to rapidly and widely tune the structural color in response to a change in temperature while maintaining close-packed arrays. The spherical symmetry of the microcapsules renders them optically isotropic, i.e., displaying orientation-independent color. In addition, as a solid membrane is used to protect the delicate crystallites from external stresses, their high stability is assured. More importantly, each microcapsule reports the temperature of its microenvironment so that a suspension of capsules can provide information on the spatial distribution of the temperature.

Large scale manufacturing of electrically conductive carbon nanotube (CNT) sheets with production capability, low cost, and long-term electrical performance stability is still a challenge. A new method to fabricate highly conductive continuous buckypaper (CBP) with roll-to-roll production capability and relatively low cost is reported. The electrical conductivity of CBP can be improved to 7.6 × 104 S m−1 by using an oxidant chemical (i.e. HNO3 and I2) doping method. To compensate for the conductivity degradation caused by the instability of the oxidant chemical doping, a polymer layer of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) was coated on the chemically doped CBP. The fabricated highly conductive CBP showed stable electrical performance in air for more than a month. This CBP material with high electrical conductivity, relatively low cost, and roll-to-roll manufacturing capability could enable a wide range of engineering applications including flexible conductors, electromagnetic interference (EMI) shielding materials, and electrodes in energy devices.

Raman mapping technique has been used to perform in-line quality inspections of nanomanufacturing processes. In such an application, massive high-dimensional Raman mapping data with mixed effects is generated. In general, fixed effects and random effects in the multi-array Raman data are associated with different quality characteristics such as fabrication consistency, uniformity, defects, et al. The existing tensor decomposition methods cannot separate mixed effects, and existing mixed effects model can only handle matrix data but not high-dimensional multi-array data. In this paper, we propose a tensor mixed effects (TME) model to analyze massive high-dimensional Raman mapping data with complex structure. The proposed TME model can (i) separate fixed effects and random effects in a tensor domain; (ii) explore the correlations along different dimensions; and (iii) realize efficient parameter estimation by a proposed iterative double Flip-Flop algorithm. We also investigate the properties of the TME model, existence and identifiability of parameter estimation. The numerical analysis demonstrates the efficiency and accuracy of the parameter estimation in the TME model. Convergence and asymptotic properties are discussed in the simulation and surrogate data analysis. The case study shows an application of the TME model in quantifying the influence of alignment on carbon nanotubes buckypaper. Moreover, the TME model can be applied to provide potential solutions for a family of tensor data analytics problems with mixed effects., Comment: 29 pages, 8 figures

While the mechanical properties of highly aligned carbon nanotube (CNT) thin films and their nanocomposites have been widely studied, the load transfer mechanisms and failure modes of aligned CNT composites have not been sufficiently explored and understood. In this research, super-aligned CNT thin films with a measured alignment fraction of up to 0.93 are fabricated by mechanical stretching. High concentration (50–60 wt% CNT) CNT reinforced bismaleimide (CNT/BMI) nanocomposites are fabricated from the aligned network to study mechanical properties and microstructures. Atomic resolution transmission electron microscopy (TEM) analysis reveal unusual CNT crystal packing and permit the observation of interesting structural features of the CNTs and their assemblages, including collapse, flattened packing, preferred stacking, folding and twisting phenomena, as well as CNT pullouts from bundles and the resin matrix. The large surface-to-surface contact areas between aligned and flattened nanotubes, driven by van der Waals interactions, give rise to a high density packing of the flattened CNTs in the nanocomposite, resembling a graphitic material. Molecular dynamics (MD) simulations are performed to model the packing structure and understand the dependence of density on the relative content of flattened nanotube and void space. The modeling results support the conclusions drawn from the experimental observations.

Due to the nanoscale size of carbon nanotubes (CNTs), observing the CNT/CNT and CNT/resin interactions in nanocomposites requires a high resolution transmission electron microscope (TEM) analysis. This research focuses on developing a protocol to provide an effective and reliable approach to obtain ultra-thin ( Two CNT nanocomposite samples made with different resins were studied for both microtome cutting and TEM analysis and it revealed the alignment direction of the nanotubes and numerous stacks of CNT bundles. In addition, there was visible flattening of CNT packing into dumbbell shapes similar to results obtain in CNT yarn materials. TEM for the 3-layer CNT BP/BMI nanocomposite revealed uniform cutting in the resin areas. However, when the diamond knife reached graphite crystalline regions, the nanotubes either became deformed into a cone-like structure, were cut thicker than the resin, or folded over onto itself. This is most likely due to the high mechanical properties of CNT in response to the stress of cutting.

Crystalline or glassy materials made of colloidal nanoparticles show distinctive photonic effects; the crystals exhibit sparkling colors with strong iridescence, while the glasses show noniridescent colors. Both colors are the results of constructive interference of the reflected light by the nonadsorbing nanostructures. Such colored materials have potential applications as nonfading colorants in reflective color displays, optical sensors, coatings, and cosmetics. All of these applications require granular format of the nanostructures; however, precise control of the nanostructures from amorphous to crystalline over the submillimeter length scale remains challenging. Here, we present micrometer-level control of photonic nanostructures confined in microcapsules through osmotic-pressure-mediated concentration. We encapsulate aqueous suspensions of colloidal particles using double-emulsion drops with ultrathin layers of photocurable resin. The microcapsules are then isotropically compressed by imposing a pos...

Higher concentrations of long carbon nanotubes (CNTs) that are aligned and functionalized can improve the mechanical properties of CNT composites. For this purpose, pristine/random CNT sheets were mechanically stretched at different strains of 40 %, 60 % and up to 80 %. The higher degree of CNT alignment was confirmed by scanning electron microscope (SEM) images and the degree of alignment was quantified by X-ray scattering and polarized Raman spectroscopy. The highest degree of alignment of 0.93 was achieved by using this method. Aligned CNT sheets were functionalized and CNT/bismaleimide (BMI) composites were fabricated. The mechanical properties of the composites were improved with a higher degree of alignment achieving a modulus of 252 GPa and tensile strength of over 1.4 GPa for an 80% stretched CNT/BMI composite. To understand the internal CNT packing and the CNT/resin interface, thin composite cross sections that are perpendicular to the alignment direction were prepared using focused ion beam (FIB) with a lift-out process. Using a high-resolution transmission electron microscopy (HRTEM), relatively large diameter CNTs (> 5 nm) cross sections and double-walled CNT bundles were observed. An increased number of densely packed and collapsed CNT structures were also observed with higher stretch ratio, which confirmed the CNT alignment and dense packing along the stretch direction. The CNT/resin interface was also analyzed by electron energy loss spectroscopy (EELS). Carbon K-edge peak was used to identify the functionalization of CNT, and a ratio of 1s-* to 1s-* transition was mapped by a scanning TEM. A decreased */* transition ratio was observed at the edge of CNT packing and could be related to the reduced sp2 bonding after functionalization. This leads efficient load transfer between CNT and resin, thus higher mechanical properties.

This paper reports on highly sensitive aligned carbon nanotube network (CNTN)-based strain sensors produced by aerosol jet printed electrodes and polyimide substrates. Two types of sensing mechanisms were revealed. Type A sensors, whose electrodes were directly printed on the CNTNs and embedded in epoxy resin, take advantage of the intrinsic piezoresistive properties of highly oriented carbon nanotube bundles and exhibited large positive gauge factor. Type B sensors, whose electrodes were printed on the polyimide substrate, utilize the effects of applied strains on the contact resistances between layers of the CNTN structure and between CNTN and the electrodes, exhibited large negative gauge factors. Type A and B sensors achieved positive and negative gauge factors up to 20 and 40 in magnitude, respectively. The high performance and flexible nature of the sensors, combined with the capability of scalable manufacturing processes, exhibits promising application potentials.

Structurally colored materials could potentially replace dyes and pigments in many applications, but it is challenging to fabricate structural colors that mimic the appearance of absorbing pigments. We demonstrate the microfluidic fabrication of "photonic pigments" consisting of microcapsules containing dense amorphous packings of core-shell colloidal particles. These microcapsules show non-iridescent structural colors that are independent of viewing angle, a critical requirement for applications such as displays or coatings. We show that the design of the microcapsules facilitates the suppression of incoherent and multiple scattering, enabling the fabrication of photonic pigments with colors spanning the visible spectrum. Our findings should provide new insights into the design and synthesis of materials with structural colors.

This paper presents simulation results for double nanohole and inverted bowtie nanoapertures optimized to resonate in the short-wave infrared regime (1050 nm and 1550 nm). These geometries have shown great promise for trapping nanoparticles with applications in optical engineering, physics, and biology. Using a finite element analysis tool, we found that the outline length for inverted bowtie nanoapertures in a 100 nm thick gold film with a 20 nm gap dimension having an optimized transmission resonance for 1050 nm and 1550 nm optical wavelengths is 106.5 nm and 188.5 nm, respectively. With the same gap size, the radii of the circles for the double nanohole nanoapertures are 72 nm and 128 nm. The near-field enhancements of the two structures are almost the same, while the double nanohole geometries have a 20% larger full width at half-maximum than the inverted bowtie. Next, by studying the effect of changing the inner radii of the inverted bowtie corners, we found that the difference between 2 nm and 6 nm corner radii can blue-shift the optical resonance by up to 45 nm. As a result of not having any inner corners, the double nanohole structure requires less precise fabrication and therefore could potentially have a higher successful yield of nanoapertures during the manufacturing process. Lastly, we will show experimental results that confirm the optical resonance of the nanoapertures at 1550 nm. These results will enable better performance and signal-to-noise ratio in nanoaperture trapping for the short-wave infrared wavelength regime.

The purpose of this study was to evaluate microbial populations, Hunter's color values (L⁎, a⁎, b⁎) and the sensory quality of freeze-dried miyeokguk, Korean seaweed soup, in order to use it as space food. Microorganisms were not detected in non-irradiated freeze-dried miyeokguk within the detection limit of 1.00 log CFU/g. However, the microbial population in rehydrated miyeokguk was 7.01 log CFU/g after incubation at 35 °C for 48 h, indicating that freeze-dried miyeokguk was not sterilized by heat treatment during the preparation process. Bacteria in the freeze-dried miyeokguk were tentatively identified as Bacillus cereus, B. subtilis, Enterobacter hormaechei, and Ancinetobacter genomosp. using the 16S rDNA sequencing. In samples that were gamma-irradiated above 10 kGy, it was confirmed that all microorganisms were inactivated. Hunter's color values of the samples irradiated at doses less than 10 kGy were not significantly altered from their baseline appearance (p>0.05). Sensory evaluation showed that preference scores in all sensory properties decreased when freeze-dried miyeokguk was irradiated at doses greater than 10 kGy. Therefore, the results of this study suggest that gamma irradiation at 10 kGy is sufficient to sterilize freeze-dried miyeokguk without significant deterioration in the sensory quality, and thus, the freeze-dried and irradiated miyeokguk at 10 kGy fulfills the microbiological requirements as space food.

The mechanism of carbon nanotube (CNT) alignment during stretching was examined by the in situ characterization of carbon nanotube networks (CNTNs) under tensile strains using X-ray and Raman scattering techniques. A method of quantifying the inhomogeneous alignment of macroscopic CNTNs is explored based on bulk property measurements of their electrical anisotropy and X-ray diffraction diagrams. The results show that the process of stretch-induced alignment of CNTNs included straightening the waviness of the long nanotube ropes, as well as the self-assembling and denser packing of the nanotubes. For samples at a strain of 40%, the fraction of aligned nanotubes was as high as 0.85. The aligned fraction of CNTs serves as an important parameter for the quality control of the alignment process and numerical simulations of structure–property relationships of CNTNs and their composites.

Innovative printing technology enables fine feature deposition (below [email protected]) of electronic materials onto low-temperature, non-planar substrates without masks. This could be a promising technology to meet the requirements of present and future microelectronic systems. Silver nanoparticles (NP) ink is widely used for printed electronics; however, its electrical conductivity is low compared to bulk materials. In order to improve the electrical conductivity of printed tracks for the aerosol printing technique, we developed a novel carbon nanotubes (CNTs)/silver NP ink by mechanical stirring and sonication. The produced sample inks with different concentration of CNTs that were printed with a Maskless Mesoscale Material Deposition (M^3D) Aerosol Jet(R) printing system. The dimensions of the printed lines were determined by atomic force microscopy (AFM) and the electrical resistivity was evaluated using the four-point method. Scanning electron microscopy (SEM) was used to characterize the morphology of printed tracks. We found that the CNTs bridged the defects in some printed silver lines, thereby lowering the electrical resistivity by 38%. However, no further improvements were observed with a higher CNT concentration in the silver NP ink samples. We hypothesize that CNT bridges connects the defects thus decreasing the resistivity of printed silver lines when CNT concentration is under the percolation level. However, due to aggregation of CNTs when it is above a concentration threshold, the resistivity of printed silver lines stops decreasing and even increases because of Schottky barrier effect.

Carbon nanotubes (CNTs) show great promise to improve composite electrical and thermal conductivity due to their exceptional high intrinsic conductance performance. In this research, long multi-walled carbon nanotubes (long-MWCNTs) and its thin sheet of entangled nanotubes were used to make composites to achieve higher electrical and thermal conductivity. Compared to short-MWCNT sheet/epoxy composites, at room temperature, long-MWCNT samples showed improved thermal conductivity up to 55 W/mK. The temperature dependence of thermal conductivity was in agreement with κ ∝ T n ( n = 1.9–2.3) below 150 K and saturated around room temperature due to Umklapp scattering. Samples with the improved CNT degree of alignment by mechanically stretching can enhance the room temperature thermal conductivity to over 100 W/mK. However, functionalization of CNTs to improve the interfacial bonding resulted in damaging the CNT walls and decreasing the electrical and thermal conductivity of the composites.

Pork is known as an allergenic food with porcine serum albumin (PSA, 66 kDa) representing the major allergen. This study was conducted to investigate the change in antigenicity of PSA in gamma-irradiated sausage extract treated with pepsin and trypsin. Sausage products (A and B) were irradiated at 1, 3, 10, and 20 kGy. After irradiation, sausage proteins were extracted and digested with pepsin (1:200, 30 min) and trypsin (1:300, 5, 30, 60, 90, and 120 min). The binding ability of PSA in extracts of the irradiated sausages (A and B) decreased by over 3 kGy relative to the binding ability of PSA in extracts of intact sausages and showed no notable differences when the dose of radiation ranged from 3 to 20 kGy. After treatment with pepsin and trypsin, the binding ability of PSA in extracts of the irradiated sausages was decreased more relative to that of intact sausages and showed no significant differences when the period of trypsin treatment is increased or when the dose of irradiation is increased. The sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) results indicated that there was no visible change in the intensity of the PSA band in extracts of the irradiated sausages. After pepsin and trypsin treatment, the intensity of PSA band faded with increasing doses of irradiation. In conclusion, antigenicity of PSA in pork sausages could be reduced by gamma irradiation.

Viscosity is critically important for bulgogi sauce. However, exposure to irradiation may decrease the rheological proper-ties of bulgogi sauce. This study was conducted to compare the effects of gamma irradiation (0–9 kGy) on viscosity, molec-ular weight, pH, reducing end level, and water solubility of xanthan gum, guar gum, and locust bean gum as thickeningagents/stabilizers in bulgogi sauce. The physicochemical properties of all samples changed (p

We conducted this study to determine the optimum dose of gamma irradiation needed for the sterilization of milk porridge for patients. Milk porridge, known as Tarakjuk, was irradiated with gamma ray at doses of 0, 1, 3, 5, 7, or 10 kGy. The microbial contamination, values of isolated microbe spores, color, and viscosity were measured during storage at . The initial count of total aerobic bacteria was 2.60 log CFU/g in the non-irradiated milk porridge, but coliforms, spore-forming bacteria, yeast, and molds were not detected. The total counts of aerobic and spore-forming bacteria in the non-irradiated and 1 kGy irradiated milk porridge increased with storage period. These microbes were not detected in the milk porridge irradiated with 10 kGy. The values of isolated spores from milk porridge were 2.71 kGy (in milk porridge) and 2.21 kGy (in saline solution). All CIE color increased with gamma irradiation, but the sensory value of color did not significantly change. The viscosity of the milk porridge decreased with gamma irradiation and storage period, and the decrease in viscosity with storage period became smaller as the radiation doses increased. Sensory evaluation scores of the milk porridge were above normal (4.0) when irradiated with less than 5 kGy. These results indicate that gamma irradiation could be beneficial for preparing food with higher nutrient density and lower viscosity, especially for gastric tube-fed patients.

Ecklonia cava (EC) was irradiated with γ-rays at doses of 3, 7, and 20 kGy. The extraction yields, total polyphenol content (TPC), DPPH radical scavenging activity, antimicrobial activity, and color of the EC extracts were assessed. The results showed that irradiation caused an increase in the extraction yields of ethanol and water. TPC was found to be significantly increased when EC powder was subjected to irradiation, followed by ethanol and water extraction. However, DPPH radical scavenging and antimicrobial activities were stable under all irradiation conditions. In the heat and pH stability tests, the DPPH radical scavenging activities of EC ethanol extracts were not influenced by irradiation. Irradiation caused an increase in the lightness and redness of EC extracts and decreased the yellowness. In conclusion, γ-irradiation increased the extraction yield and TPC and brightened the color, while maintaining the antioxidant and antimicrobial activities.

Off-flavor and lipid oxidation are possible defects of irradiated bulgogi. This study compared the effects of several physico-chemical treatments on microbial safety, volatiles, lipid oxidation, and sensory properties of irradiated beef bulgogi. Samples were separately irradiated with 20 kGy after each treatment such as packaging (aerobic and vacuum), antioxidants (vitamin C+α-tocopherol (0.0 and 1.0%, w/w)), charcoal teabags (0 and 0.5%), or different temperatures (room temperature, -20, and -70°C). No bacterial growth was observed (p

The wholesomeness of 40 kGy irradiated ready-to-eat (RTE) bulgogi was evaluated by subacute toxicity studies (body weight, food consumption, organ weight, hematology, serum biochemistry, and histopathological examination) with groups of 40 male and female ICR mice fed the agent at dietary levels of 5% for 90 days. There were no treatment-related adverse effects with regard to body weight, food consumption, organ weight, hematology, serum biochemistry, and histopathology. The no-observed-adverse-effect-level (NOAEL) was also determined to be greater than dietary level of at least 5% (3900 ㎎/㎏ body weight/day for males, 3500 ㎎/㎏ body weight/day for females) for samples under the present experimental conditions. These results suggest that, under these experimental conditions, RTE bulgogi irradiated at 40 kGy did not show any toxic effects.

This study examined the effect of gamma irradiation (3-20 kGy) on the immune activity and physicochemical properties of Myagropsis myagroides (MM) water extracts. MM powder and water extracts were subjected to gamma irradiation at 3, 7, and 20 kGy. The effects of gamma-irradiated MM water extracts on splenocyte proliferation and cytokine IFN-γ and IL-2 secretion were evaluated. The gamma-irradiated MM water extracts resulted in decreased splenocyte proliferation without cytotoxicity. The IFN-γ and IL-2 secretion increased by gamma-irradiated MM water extracts with increasing irradiation dose. For MM powder, the yield and total phenolic compounds (TPC) of water extracts were increased slightly after gamma irradiation. In MM water extracts, the TPC was higher at a dose of 20 kGy, while gamma irradiation decreased the viscosity, pH, and color of the MM extracts. In conclusion, gamma irradiation improved the immunomodulatory activity of MM water extracts, overcoming its potential weakness when applied in the food industry.

Carbon/carbon composites consisting of single-walled carbon nanotube (SWCNT) buckypaper (BP) and mesophase pitch resin have been produced through impregnation of BP with pitch using toluene as a solvent. Drying, stabilization and carbonization processes were performed sequentially, and repeated to increase the pitch content. Voids in the carbon/carbon composite samples decreased with increasing impregnation process cycles. Electrical conductivity and density of the composites increased with carbonization by two to three times that of pristine BP. These results indicate that discontinuity and intertube contact barriers of SWCNTs in the BP are partially overcome by the carbonization process of pitch. The temperature dependence of the Raman shift shows that mechanical strain is increased since carbonized pitch matrix surrounds the nanotubes.

This study compared the effects of autoclaving (AC; 121 C for 15 min), gamma (GR), and electron beam irradiation (EB; 0-20 kGy) on the microbial, physicochemical, and sensory properties of ready-to-eat bulgogi during storage at 35 C for 90 d. No viable cells were observed (p

This study was conducted to evaluate the combined effect of heating and γ-irradiation on the microbiological and sensory characteristics of gochujang sauce. Gochujang sauces could be sterilized by heating (HT: 121°C for 15 min) or γ-irradiation (IR: 30 kGy), but their sensory qualities were severely decreased. Otherwise, the combined treatment of heat and γ-irradiation could minimize the change of sensory qualities. Combination treatment of γ-irradiation at 17.5 kGy after heating at 100°C for 30 min (HT-IR) would be optimal. During storage the gochujang sauce samples then were analyzed to enumerate total bacterial populations, to measure pH, and Hunter’s color values, and for sensory evaluation. Any growth of total bacterial populations was not observed in HT, IR, and HT-IR (detection limited 1< log CFU/g). The pH values of gochujang sauce ranged from 4.57 to 4.75 during storage. The Hunter’s (L*, a*, and b*) values of gochujang sauce were gradually decreased during storage, regardless of treatment. Sensory characteristics and acceptance of HT and IR were significantly lower (p

Pork is an excellent source of essential nutrients such as protein. However, pork can trigger hypersensitivity and serumalbumin of pork is known as major allergen. In this study, to evaluate the effect of gamma irradiation on the allergenicity ofporcine serum albumin (PSA), PSA solution was irradiated at 3, 5, 7, 10, 15, and 20 kGy. The changes in the ability of PSAto bind IgG and patient’s serum caused by gamma irradiation were observed by ci-ELISA and immunoblotting. SDS-PAGEwas used for measuring the conformational change of gamma-irradiated PSA. The ability of 3-kGy-irradiated PSA to bindp-IgG and patient’s serum was decreased to 30% and 15%, respectively. The binding ability showed no significant differ-ences among all irradiated samples. SDS-PAGE showed that the irradiated PSA bands were degraded and aggregated.Immunoblotting of irradiated PSA revealed that IgG and patient’s serum were rarely recognized at 3 kGy. Therefore, gammairradiation could be applied to less-allergenic pork products. Key words: porcine serum albumin, allergenicity, gamma irradiation

We describe the self-assembly of biomimetic isotropic films which display structural color amenable to potential applications in coatings. Isotropic structures can produce color if there is a pronounced characteristic length-scale comparable to the wavelength of visible light and wavelength-independent scattering is suppressed., Comment: 8 pages, 5 figures

The purpose of this study was to search for physical treatments to reduce allergenicity of pork. Physical treatments suchas heating, autoclave, microwave, sonication, and irradiat ion have been used for food processing or reduction of allergenic-ity. The porcine serum albumin ( PSA), known as a major allergen in pork, was extracted after physical treatments. The anti-genicity of pork extract s by heating (80 and 100 o C for 20 min), autoclave (121 o C for 5, 10, and 30 min), and microwave (for5 and 10 min) was significantly decreased. Especially, th e binding ability of p-IgG to pork extracts by autoclave for 30 minshowed the greatest decrease (about 3%) in physical treatments. However, the antigenicity of pork was unaffected by soni-cation and irradiation treatment. These results indicated that the autoclave treatment was the most effective method toreduce the antigenicity of pork. Key words: PSA, pork, physical treatments, antigenicity 서론 우리나라 국민 1인당 육류 소비량은 2007년 기준으로쇠고기 7.6 kg, 닭고기 8.6 kg, 돼지고기 19.2 kg임을 미루어 볼 때 돼지고기는 국내에서 가장 많이 소비되는 식육류이다. 이 외에도 돼지고기는 지난 40여 년간 가장 빠른소비 증가 추세를 나타내었는데, 1970년에서 2008년 사이1인당 돼지고기 소비량의 연평균 증가율은 5.26%로 쇠고기와 닭고기가 각각 4.86%, 4.78%를 나타난 것에 비해 높았다(Ahn and Jo, 2009).한편, 돼지고기는 쇠고기에 비하여 콜레스테롤 함량이낮으며 vitamin B군 뿐만 아니라 필수지방산인 vitamin F도 다량 함유하고 있는 식품이다(Wood

This study was conducted to examine the bleaching of an anti-inflammatory agent containing Undaria pinnatifida extract (AIAU). Brown-colored AIAU was irradiated with gamma rays at doses ranging from 10-200 kGy. Discoloring of the anti-inflammatory agent was achieved by gamma irradiation, with significantly removal by 50 kGy irradiation. The main active compound of the agent consisted of 4% U. pinnatifida extract, which inhibited inflammatory symptoms in mouse ear edema by 93%. There was no change in effects against edema, erythema, blood flow and radical scavenging activity by irradiation.

This study examined the effect of gamma irradiation on shelf-life extension and sensory characteristics of dak-galbi. Commercial dak-galbi sauce was gamma-irradiated at 0, 5, 10, 15, 20, 25, and 30 kGy. The dak-galbi sauce (200 g) was then added to diced chicken (800 g) for cooking, and the cooked dak-galbi samples in vacuum bags were stored at 35 o C for 5 d. Dak-galbi samples were analyzed on d 0, 1, 2, 3, 4, and 5 for microbial analysis (plate count agar), thiobarbituric acid (TBARS) and volatile basic nitrogen (VBN) measurements, and on d 0 for sensory evaluation. On d 0, total bacterial populations were below detection limit after dak-galbi marinated with the gamma-irradiated (≥15 kGy) sauces were cooked, and the samples marinated with higher dose irradiated dak-galbi sauce had lower (p

Multi-walled carbon nanotube (MWNT)-sheet-reinforced bismaleimide (BMI) resin nanocomposites with high concentrations (∼60 wt%) of aligned MWNTs are successfully fabricated. Applying simple mechanical stretching and prepregging (pre-resin impregnation) processes on initially randomly dispersed, commercially available sheets of millimeter-long MWNTs leads to substantial alignment enhancement, good dispersion, and high packing density of nanotubes in the resultant nanocomposites. The tensile strength and Young's modulus of the nanocomposites reaches 2 088 MPa and 169 GPa, respectively, which are very high experimental results and comparable to the state-of-the-art unidirectional IM7 carbon-fiber-reinforced composites for high-performance structural applications. The nanocomposites demonstrate unprecedentedly high electrical conductivity of 5 500 S cm−1 along the alignment direction. Such unique integration of high mechanical properties and electrical conductance opens the door for developing polymeric composite conductors and eventually structural composites with multifunctionalities. New fracture morphology and failure modes due to self-assembly and spreading of MWNT bundles are also observed.

Addition of calcium lactate and vitamin C, a mild heating, deep-freezing, and gamma irradiation at 25 kGy were conducted to prepare Kimchi as a ready-to-eat space food. It was confirmed that the space food was sterilized by an irradiation at 25 kGy through incubation at 37 °C for 30 days. The hardness of the Space Kimchi (SK) was lower than the untreated Kimchi (CON), but higher than the irradiated Kimchi (IR). Also, this result was supported by the scanning electron microscopic observation. Sensory attributes of the SK were similar to CON, and maintained during preservation at 35 °C for 30 days. According to the Ames test, Kimchi sterilized with a high-dose irradiation exerted no mutagenic activity in the bacterial strains of Salmonella typhimurium . And, the SK was certificated for use in space flight conditions during 30 days by the Russian Institute of Biomedical Problems.

This study was conducted to determine the effects of gamma and e-beam irradiation on the quality of minced pork and pork patties. Each sample was irradiated at 5 to 20kGy, and its quality characteristics were then evaluated during storage at 30. The results of the total bacterial populations in the minced-pork and pork patty samples showed that the antimicrobial effect of gamma irradiation was superior to that of e-beam irradiation. The 2-thiobarbituric acid reactive substances (TBARS) value of all the samples significantly increased (p(brightness), (redness), and (yellowness) of the minced pork and pork patties, were increased (p

Objective: The purpose of this study was to investigate the value of color as a component of a healing environment for pediatric patient rooms. Color preferences from pediatric inpatient, pediatric outpatient, and healthy children groups were investigated and compared for group and gender differences. Background: Positive environmental stimulation can promote patient well-being by reducing stress or negative feelings. If environmental colors can have positive influences, then those colors will make patients more comfortable, reducing their stress. Although previous color studies are suggestive, none has focused on pediatric healthcare environments. Patients' health status may affect their reaction to environmental stimulation. There was a gap in the body of knowledge regarding the consistency of color preferences with regard to patient health status. Methods: A simulation method was used because of its reliability and feasibility. It allowed for investigating the value of color in real contexts and controlling confounding variables. Previous color preference studies typically have been done with small colored squares of paper, which are visually different from seeing a color applied on wall surfaces. In addition, they failed to control confounding variables such as color attributes and light sources. Results: Group differences were not significant. This refuted the hypothesis that the color preferences of pediatric patients are different from those of healthy children. However, overall color preferences showed that the healthy children group had higher mean scores of color preferences than both pediatric outpatients and inpatients groups. Gender effects were identified across all three groups. Conclusions: All three groups showed similar color preference patterns, except for yellow. Both pediatric outpatients and inpatients preferred yellow less than healthy children did. Healthy children's mean scores of color preferences were higher than the pediatric outpatients; the pediatric outpatients group had higher mean scores of color preferences than the pediatric inpatients group. Although this observation was not statistically significant, it raised the question of whether the sickest pediatric patients respond differently to color than healthy children do. Gender effects indicated that girls preferred red and purple more than boys do. Regardless of gender effects, healthy children and pediatric patients preferred blue and green the most and white the least. These results can help healthcare providers and professionals better understand appropriate colors for pediatric populations.

The objective of this study was investigated to apply the fucoidan and laminarin extract from low-grade Undaria pinnatifida to real food product, a pork patty. Pork patties added with fucoidan and laminarin showed lower lipid oxidation and the inhibition against lipid oxidation was shown to be dependent on the irradiation doses. The Hunter color values of pork patty added with fucoidan increased significantly with an increase of irradiation dose. The hardness profiles of the patties with fucoidan and laminarin was decreased, but the amount of water in the patties was increased. Also, the combination of gamma irradiation and addition of fucoidan and laminarin was shown to be effective for the microbiological control. These results suggested that gamma irradiation and fucoidan and laminarin treatment showed the positive effect on microbial stability and quality of the pork patty.

Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeonbuk 580-185, KoreaAbstractThe effects of γ-irradiation on antioxidant and physicochemical properties of powder and 70% fermented ethanol extracts of Ishige okamurai (I. okamurai) were investigated. In case of powder, although yields were increased, there were no significant changes in total phenolic compounds (TPC) and 2,2-diphenyl-2-picrylhy-drazyl (DPPH) radical scavenging effect by γ-irradiation at 3, 7, and 20 kGy. In case of 70% fermented ethanol extracts, the results of TPC and DPPH radical scavenging effects showed no significant changes. However, antioxidant index increased in the 20 kGy irradiated I. okamurai extracts and decreased in 3 kGy irradiated ones. The optical density value of UV spectrum at 427 nm significantly decreased depending on increasing irradiation dosage. In conclusion, irradiated extracts of I. okamurai can be applied to the food industry due to irradiation stability on antioxidant properties. Also, irradiated extracts can be more useful for food process-ing as a result of a decrease of extracts color by irradiation.Key words: Ishige okamurai, antioxidant, γ-irradiation, color

Single-walled carbon nanotube (SWCNT) buckypaper (BP) was exposed to high temperatures with electrical current-driven thermal heating either in the air or a vacuum. High electrical currents generate Joule heating and then cause breakdown of the BP in the air at over 400 °C due to rapid oxidation. In the vacuum, electrical resistive heating can generate temperatures of more than 2000 °C for the samples. Structural changes of SWCNTs after electrical current heating were observed using electron microscopy and Raman spectra. After breakdown of BP, the disorder-induced D-band increased and a smaller diameter related radial-breathing mode was reduced in the high temperature region. Structural transformations of SWCNT to other carbon nanostructures were observed after current-driven high-temperature treatment in the vacuum. In addition, surface-enhanced Raman scattering with intensity enhancement more than ten times was observed in the BP with agglomerated Fe or Ti particles.

The present study was conducted to evaluate the effect of irradiation temperature on the shelf stability and quality of Kimchi during storage at 35 °C for 30 days. Kimchi samples were N 2 -packaged and heated at 60 °C and then gamma irradiated at 20 kGy under various temperatures (room temperature, ice, dry ice, and liquid nitrogen). In the results of microbial, pH, and acidity analysis, combination treatment of heating and irradiation was able to sterilize microbes in Kimchi regardless of irradiation temperature. When Kimchi was irradiated under frozen temperatures, especially dry ice, the softening of texture and the deterioration of sensory quality of Kimchi were reduced. Also, ESR signal intensities were weakened due to the decrease of irradiation dose and temperature.

Yukwa were added with non-fermented tea (Bucho-cha and Okro-cha), semi-fermented tea (Ooreung-cha), and fermented tea (black tea) to investigate the effect of different kinds of tea powder on quality characteristics of Yukwa during storage. Yukwa samples were used for analysis such as crude lipid, moisture, texture, antioxidative property (TBA value), and sensory test. There were no significant differences on crude lipid, moisture, and texture analysis. Green tea powder treatment showed strong antioxidant activity. In particular, antioxidant property of non-fermented tea exhibited a higher antioxidative effect than that of the other samples. Sensory evaluation showed that sensory scores of samples added with non-fermented tea were significantly higher than the other samples, indicating that the addition with 0.1% of non-fermented tea powder could contribute to the improvement of quality and shelf-life of Yukwa during storage.

In this study, the antioxidant properties and physical characteristics of irradiated Sargassum siliquastrum water extract were evaluated. Samples were irradiated with Co 60 γ-ray at doses ranging from 3 to 20 kGy. They were then analyzed to investigate antioxidant properties, including total phenolic compound content and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. In addition, physical properties such as viscosity and color were evaluated. The results demonstrated that total phenolic compound content and DPPH radical scavenging activity were significantly improved (p

This study was carried to investigate effects of gamma irradiation on the moisture, crude protein, crude lipid, 2-thiobarbituric acid (TBA) values, color stability, texture, and sensory properties of restructured pork jerky. Restructured pork jerky was irradiated at dose levels of 0, 3, 5, 7 and 10 kGy with a use Co-60 source. There were no significant differences in the moisture, crude protein, crude lipid contents, and TBA values. However, as doses of gamma irradiation increased, the redness (a-value) of restructure pork jerky increased whereas shear force of restructure pork jerky was decreased by gamma irradiation. Sensory evaluation showed that sensory scores were reduced by gamma irradiation. Therefore, gamma irradiation could be an effective means to improve color and texture of restructured pork jerky, but only with proper consideration for sensory quality.

Paprika oleoresin (PO) and artificial Kimchi flavor (AKF) were added to Kimchi to improve the sensory qualities deteriorated by gamma irradiation in terms of color and flavor. Optimum concentration of both PO and AKF resulting from the sensory evaluation was 0.2%. The redness and capsanthin contents of Kimchi decreased by gamma irradiation at 25 kGy during storage at . However, the redness and capsanthin contents of gamma-irradiated Kimchi was increased by the addition of 0.2% PO, and maintained during the storage at for 30 days. The result from the sensory evaluation indicated that sensory qualities of gamma-irradiated Kimchi were effectively improved by the addition of PO and AKF during storage at . Therefore, the combined treatment of additives (PO and AKF) and gamma irradiation can be considered as an effective method to improve the redness and sensory qualities of Kimchi sterilized by high-dose gamma irradiation.

This study was conducted to evaluate the combined effects of N2-packaging (N2), mild heating at 60 °C (HT) and gamma irradiation of 20 kGy (IR) on the shelf-stability and quality of Kimchi during storage at 35 °C for 30 days. Total microbes including lactic acid bacteria were sterilized perfectly by the combination treatment of HT–IR or N2–HT–IR, and the acidity of Kimchi was not changed during storage. Irradiation softened textural property of Kimchi. However, combination of N2-packaging with heating and irradiation retarded this softening of Kimchi by high dose irradiation. Organoleptic qualities were improved by the combination treatment during the storage period.

The electrical transport properties of mesoscopic graphite have been investigated in a gate voltage configuration. Few layer graphene structures made from Kish graphite exhibit Shubnikov-de Haas (SdH) oscillations in magnetic fields up to 33 T, with a strong gate voltage dependence. A two band model can be used to explain the linear dependence of the SdH frequency on the gate voltage. The temperature dependence of the SdH oscillation amplitude allows the determination of the effective masses of the carriers, which remain comparable between mesoscopic and bulk graphite samples. However, mesoscopic graphite thinner than 130 nm does not exhibit the field induced charge density wave transition seen in bulk samples above 25 T at low temperatures.

Funtionalized pentancene, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene), field-effect transistors (FET) were made by thermal evaporation or solution deposition methods and the temperature dependent mobility was measured. The field-effect mobility (μFET) activation energy is gate voltage dependent. At low gate voltage, activated conduction is dominant with Ea ∼ 0.27 eV, slightly smaller than the bulk value, and the activation energy decreases with increasing gate voltage. This is ascribed to traps in the film. A non-monotonic temperature dependence is observed at high gate voltage (VG