• Culinary science and hospitality research
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• v.13 no.2
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• pp.254-259
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• 2007

The control of enzymic browning in potato slices by the use of citrate and phosphate buffer at different pH values and concentration was investigated. Minimally processed potatoes were stored at $5^{\circ}C$ and $20^{\circ}C$ followed by dipping in distilled water, citrate buffer (pH $3.0{\sim}5.0$) and phosphate buffer (pH $5.0{\sim}7.0$). The color characteristic was measured after storage at $5^{\circ}C$ and $20^{\circ}C$ for 24 hours. Treatment effectiveness was greatly improved by reducing pH and temperature. The citrate buffer was more effective than phosphate buffer in the browning inhibitory capacity. The citrate buffer (pH 3.0) showed the most anti-browning effect in this condition and more effective inhibition of browning by increasing concentration of treatment solution. The phosphate buffer (pH 5.0) treatment showed more effectiveness than concentration of 0.5 M of citrate buffer treatment.

• Journal of Hydrogen and New Energy
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• v.22 no.5
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• pp.714-720
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• 2011

Ethanol was used as reducing agent to remove $NO_x$ exhaust from the stationary source. Pre-treatment with sulfuric acid over $Ag/Al_2O_3$ catalyst was dedicated to overcome the $SO_2$ poisoning effect. The $NO_x$ reduction experiment was performed under the simulated condition of power plant The increased surface area with higher CPSI devoted to increase de-$NO_x$ yield. De-$NO_x$ yield of the $NO_x$ exhaust containing 20 ppm of $SO_2$ increased after acid treatment with 0.7% $H_2SO_4$ over 4.0% $Ag/Al_2O_3$, where the increased dispersion of Ag found from the results of XRD and XPS was the dominant factor for the increased de-$NO_x$ yield. However, the reason for the decreased de-$NO_x$ yield with the acid treatment of higher concentration (1.0% and 2.0%) of $H_2SO_4$ was found to be due to the formation of $Ag_2SO_4$ crystallites found from XRD result. Acid-treated $Ag/Al_2O_3$ catalyst showed maximum de-$NO_x$ yield at higher temperature than non-treated $Ag/Al_2O_3$ catalyst did.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.319-321
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• 1984

Black pepper powder was irradiated at dose of 3,6 and 9 kGy, stored at ambient temperature in order to investigate the effect of irradiation on their microbial sterilization and physicochemical properties. Total and coliform bacteria were sterilized by irradiation up to 9 kGy and 3 kGy, respectively, and they were not grown until the end of storage period. $D_{10}$ value of total bacteria were in the range of 1.39-1.49 kGy. Proximate composition was not significantly changed according to the increase of irradiation dose except slight increase of the reducing sugar. The yield of volatile oil was slightly decreased by the increase of irradiation dose.

• Nano
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• v.13 no.11
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• pp.1850127.1-1850127.13
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• 2018

Bi metal deposited on $Bi_2MoO_6$ composite photocatalysts have been successfully synthesized via a simple reduction method at room temperature with using $NaBH_4$ as the reducing agent. The photocatalytic activity of the composite was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) solution under visible light. The rate constant of $Bi/Bi_2MoO_6$ composite to RhB is 10.8 times that of $Bi_2MoO_6$, and the degradation rate constant of BPA is 6.9 times of that of $Bi_2MoO_6$. Nitrogen absorption-desorption isotherm proved that the increase of specific surface area is one of the reasons for the improvement of photocatalytic degradation activity of $Bi/Bi_2MoO_6$ composites. The higher charge transfer efficiency of $Bi/Bi_2MoO_6$ is found through the characterization of the photocurrent and impedance, which are attributed to the surface plasmon resonance (SPR) effect produced by the introduction of the metal Bi monomer in the composite. Free radical capture experiments proved that cavitation is the main active species. Based on the above conclusions, a possible mechanism of photocatalytic degradation is proposed.

• Journal of Hydrogen and New Energy
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• v.30 no.3
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• pp.220-226
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• 2019

Magnesium hydride has a high hydrogen storage capacity (7.6 wt.%), and is cheap and lightweight, thus advantageous as a hydrogen storage alloy. However, Mg-based hydrides undergo hydrogenation/dehydrogenation at high temperature and pressure due to their thermodynamic stability and high oxidation reactivity. MWCNTs exhibit prominent catalytic effect on the hydrogen storage properties of $MgH_2$, weakening the interaction between Mg and H atoms and reducing the activation energy for nucleation of the metal phase by co-milling Mg with carbon nanotubes. Therefore, it is suggested that combining transition metals with carbon nanotubes as mixed dopants has a significant catalytic effect on the hydrogen storage properties of $MgH_2$. In this study, Material life cycle evaluation was performed to analyze the environmental impact characteristics of Mg-CaO-10 wt.% MWCNTs composites manufacturing process. The software of material life cycle assessment (MLCA) was Gabi 6. Through this, environmental impact assessment was performed for each process.

• Journal of Mushroom
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• v.16 no.4
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• pp.331-333
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• 2018

The incorporation of Shiitake culture into sawdust is a widely utilized technique that can assist in reducing the cost and time consumption associated with oak cultivation. In sawdust cultivation, browning of the surface mycelia is an important stage with respect to the utility and longevity of the sawdust media. Surface browning forms a protective coating on the substrate, which can inhibit the invasion of pathogens and suppress water evaporation. Several different light sources (red LED, white LED, blue LED, and fluorescent light) were used and the intensity of illumination was carefully controlled (1.5, 10.5, $20.5{\mu}mol/m^2s$ for LEDs and 10, 100, 300 lux for the fluorescent light) to induce browning. The light sources were regulated via a 1 h on/off cycle in a controlled room environment at a temperature of $20^{\circ}C$, 60% humidity, and 1200 ppm $CO_2$ concentration for 60days. The browning effect varied depending on the source and the intensity of illumination. This effect was most effectively induced at $1.5{\mu}mol/m^2s$ for the red and blue LEDs. All light sources induced less browning at the highest intensity of illumination. This indicates that intensity values higher than $20.5{\mu}mol/m^2s$ in the case of the LEDs and 300 lux for the fluorescent light are not effective. After harvesting of the fruit bodies, we measured the weight, length, and width of the pileus and stipe in addition to their chromaticity and hardness. Treatment with $1.5{\mu}mol/m^2s$ blue LED produced the best harvest with the highest average chromaticity, weight (21.2 g), stipe length (30.8 mm), and hardness (377.9 g), with a fine length and width of the pileus.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.3
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• pp.1-11
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• 2022

In this study, an electric resistance dual-spot welding process using a copper electrode inserted in a heating electrode is suggested for the spot welding of AZ31 magnesium sheets. This spot-welding process involves two heating methods for welding at the interfacial zone between the magnesium sheets, one of which is the heating method by thermal conduction from the heating electrode heated by the welding current induced to the steel electrode, and the other heating method uses the electric resistance between the contacted surfaces of the two sheets by the welding current induced to the copper electrode. This welding process includes the welding variables, such as the current induced in the heating electrode and the copper electrode, and the outer diameters of the heating electrode. This is because the heat conducted from the heating electrode can be maintained at a higher temperature in the welding zone, which has a slow cooling effect on the nugget of the melted metal after the welding step. The pressure exerted during the pressing of the magnesium sheets by the heating electrode can be increased around the nugget zone at the spot-welding zone. Thus, it not only reduces the warping effect of the elastoplastic deformation of sheets, but also the corona bond can make it less prone to cracking at the welded zone, thereby reducing the number of nuggets expelled out of the corona bond. In conclusion, it was known that an electric resistance dual spot welding process using the copper electrode inserted in the heating electrode can improve the welding properties in the electric resistance spot welding process of AZ31 magnesium sheets.

• Food Science and Preservation
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• v.14 no.6
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• pp.617-623
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• 2007

To utilize the non-heat treated alcoholic by-products of brown rice(Goami) as food sources, the quality characteristics change according to the treatment conditions of ${\alpha}-amylase$ were evaluated. It resulted that the increase of hydrolysis temperature correspondingly increased the soluble solids, total dietary fiber and total sugar in the by-products of Goami, and the highest reducing sugar content was observed at $80^{\circ}C$. The free amino acids contents were tended to slowly decrease by the hydrolysis temperature more than $70^{\circ}C$, and the highest content of oligosaccharides were detected at the hydrolysis temperature of $80^{\circ}C$. The soluble solid according to the ${\alpha}-amylase$ concentration resulted to increase with the increase of the enzyme concentration and the total dietary fiber revealed similarly showing approximately 0.65%. The high content of reducing sugars was observed at the enzyme concentration around 0.08%(v/w). Total sugars and oligosaccharides contents tend to increase as the concentration of enzyme increased, and the content of oligosaccharides acquired at the enzyme concentration more than 0.10%(v/w) maintained to show rather similar contents. The soluble solids and total dietary fiber by hydrolysis time were found to show 6.66% and 0.65%, respectively at more than 60 min of hydrolysis, and the reducing sugars and total sugars were found to be 3,600 and 4,800 mg% in all treatment groups showing no significant difference. The content of oligosaccharides was increased with the increase of hydrolysis time, and the content was similar at more than 90 min of hydrolysis by ranging around 2,100 mg%. Based upon these results, the by-products of Goami are expected to be used as various food sources showing the highest dietary fiber and oligosaccharides contents by the hydrolysis at $80^{\circ}C$ for 90 min with the addition of 0.10%(v/w) of ${\alpha}-amylase$.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.80-93
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• 1986

The tail portion of dried 6-year old white ginseng was extracted and sugars and nitrogen compounds were also evaluated for chemical properties depending on varying conditions of extractions. The factors studied were extraction temperature in the range of 70-$100^{\circ}C$, ethanol concentration of 0-90% and the times of extractions which was taken 8 hours per each extraction in water at $80^{\circ}C$. For the effect of ethanol concentration in the extraction solvent, it was found that the amounts of free, reducing and total sugars and starch recovered in extract were almost linearly decreased along with the increase of concentration and the nonprotein nitrogen accounted over 84% of total nitrogen in extract. As ethanol concentration became increased, extractions of total nitrogen and water souluble nonprotein nitrogen were decreased especially in 90% ethanol. For the extraction temperature, all the sugar fractions with water and 70% ethanol except free sugar have tended to increase along with the temperature raised from 70 to $100^{\circ}C$ and it was found there is little changes of nitrogen compounds in the temperature range except a rapidly increase in water soulble protein at $100^{\circ}C$. For the times of extractions, showed that most of extractable compounds were extracted in 3 times of extractions with water at $80^{\circ}C$. It was shown that more than 95f) of sugars and 80% of nitrogen compounds were yielded with water extraction. Accordingly it was efficient to extract with water or 70% ethanol in 3 times in terms of !actor and energy consumption.

• Food Science and Preservation
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• v.6 no.2
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• pp.137-142
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• 1999

Physicochemical properties were evaluated for stored garlic bulbs during 9 months under different conditions, such as low-temperature condition (3${\pm}$1$^{\circ}C$, 80${\pm}$5% RH, LT), pit-temperature condition (9${\pm}$6$^{\circ}C$, 80${\pm}$5% RH,PT) and ambient-temperature condition (14${\pm}$11$^{\circ}C$, 67${\pm}$5% RH, AT). The internal sprout development was more significant in pit and ambient conditions than in low temperature and thus certain means for sprout control is required for long-term storage of garlic bulbs under such conditions. The rates of rotting and weight loss were appreciable especially after 7 months of storage (next March) in the order of PT, AT and LT, when external sprouts were observed in PT and AT. Moisture content of stored samples were relatively constant in LT until next May, but that in W and AT was significantly reduced after next January. Total sugars showed a decreasing tendency with the prolonged period, whereas an apparent increase was found in the contents of reducing sugar and vitamin C along with external sprouting of garlic bulbs from the 7th month of storage (next March). Based on the results that around March is a limiting point in garlic storage at such conditions from the physiological and physicochemical points of view, improved storage condition should be applied to overcome the storage barrier.