• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.67-72
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• 2005

To achieve demineralization of crab shell waste by chemical and biological treatments, lactic acid and lactic acid bacterium were applied. In 5.0 and $10\%$ lactic acid, pH rapidly decreased from 6.8 to 4.2 and from 4.5 to 2.4 at day 3, respectively, and thereafter the pH remained at an almost constant level. In a $10\%$ lactic acid bacterium inoculum, pH lowered to 4.6 at day 5. Relative residual ash content rapidly decreased to 49.1 and $16.4\%$ in 5 and $10\%$ lactic acid treatments, respectively, for the initial 12 h. In 2.5, 5 and $10\%$ lactic acid bacterium inoculums, relative residual ash content rapidly decreased to 55.2, 40.9 and $44.7\%$, respectively, on the first day. Residual dry masses were 76.4, 67.8 and $46.6\%$ in 2.5, 5 and $10\%$ lactic acid treatments, respectively, for the initial 12 h. After a one-time exchange of the lactic acid solution, in the $5.0\%$ lactic acid treatment, residual dry mass rapidly decreased from 66.0 to $41.4\%$. In 2.5, 5 and $10\%$ lactic acid bacterium inoculums, residual dry masses decreased to 67.6, 57.4 and $59.6\%$ respectively, on the first day. Protein contents after demineralization ranged from $51.3{\sim}54.7\%$ in the chemical treatments and decreased to $32.3\%$ in the lactic acid fermentation process. A negative relationship was shown between pH and demineralization rate in lactic acid and lactic acid bacterium treatments. These results suggest that lactic acid fermentation can be an alternative for demineralization of crab shells, even though the rate and efficiency of the demineralization is lower than the chemical treatment.

• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.65-70
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• 2000

Ergosterol is an indicator chemical of fungi and involves in fungal cell growth as a major component in fungal cell membranes. Thus, this chemical can be used to estimate live fungal biomass within various solid substrates. Ergosterol content in liquid culture of Lentinula edodes had a linear relationship (r=0.98) with the hyphal mass of the fungus. This chemical content differed depending on the fungal strains, age of culture and water content levels of sawdust substrate. Ergosterol content was 0.13% in the 10 weeks old liquid culture while it was 0.10% in 20 weeks old one. The chemical content in the sawdust cultures of the fungus varied 0.015% to 0.042% depending upon strains and water content levels within sawdust substrate. Ergosterol content in the culture of a L. edodes strain, Sanrim 4, was higher by $20{\mu}g$ to $140{\mu}g$/g dry substrate than those of strains, Mok-H and Sanrim 6. And the chemical contents in the sawdust cultures with 125% or 175% water, 297 to 425 ${\mu}g$/g dry substrate, were higher than those with 75% or 225% water, 148 to $286{\mu}g$/g dry substrate. We conclude that ergosterol analysis can estimate the fungal biomass within solid substrate such as logs and sawdust.

• Food Science and Preservation
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• v.23 no.7
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• pp.1004-1011
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• 2016

Flavonoids, non-nutrient secondary metabolites of plants, are widely distributed in commonly consumed agro-food resources. Flavonoids include aglycones, and their glycosides are reported to have potential health-promoting compounds. The aim of this study was to investigate flavonoid glycosides in the fruit and leaves of Zizyphus jujuba var. inermis (Bunge) Rehder (jujube). A total of six flavonoids (five flavonols and one chalcone) were identified in jujube fruit and leaves by using ultra-performance liquid chromatography-diode array detector-quadrupole time of flight mass spectrometry along with chemical library and an internal standard. In positive ion mode, six flavonoids were linked to the C- and O-glycosides which were conjugated with sugar moieties based on kaempferol, quercetin, and phloretin aglycones. Total flavonoid contents of leaves (8,356.5 mg/100 g dry weight (DW)) was approximately 900-fold higher than that of fruit (fresh fruit, 13.6 mg/100 g dry DW; sun-dried fruits, 9.2 mg/100 g dry DW). Quercetin 3-O-rutinoside (rutin) and quercetin 3-O-robinobioside were the predominant flavonols in fruit and leaves of jujube. In particular, rutin had the highest content (6,735.2 mg/100 g DW) in leaves, and rutin is a widely reported bioactive compound. Phloretin 3',5'-di-C-glucoside (chalcone type) was detected only in leaves. The leaves of jujube contain a high content of flavonoids and the results of this study indicate that jujube leaves may be a source of bioactive flavonoids.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.176-182
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• 2012

The methane dry reforming has received the considerable attention in recent years, mainly as an attractive route to produce synthesis gas (CO, $H_2$) from green-house gases ($CH_4$, $CO_2$) for resources. However, this process has not been commercialized due to the high temperature and catalyst deactivation. In this study, Co-Ru-Zr catalysts supported on $SiO_2$ were studied for the characterization of methane dry reforming reaction and the preliminary data for process development were achieved. The crystal structure of catalysts was measured by XRD, the surface area and pore size were analyzed by BET, and the element composition of catalyst were analyzed by EDS. Conversions of methane and carbon dioxide were analyzed by GC. In addition, reaction rate constants were obtained from the reaction kinetic study and the optimum catalyst size that does not affect mass transfer from reactants was also determined. The selected pellet-type catalyst maintained activation for 720 h at $850^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.421-427
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• 2015

Angelica gigas Nakai is one of the most widely used herbal medicines and is known to have many pharmaceutical effects including an anti-oxidant, anti-cancer etc. This study was carried out to investigate an effect of fertilization on leaf yield, production of dry-matter and accumulation of pyranocurmarine compounds such as decursin (DE) and decursinol angelate (DA) in Angelica gigas Nakai. Effect of fertilization was determined from response surface regression equation composing of 2 by 3 factorial arrangement of urea, sodium dihydrogen phosphate and potassium chloride. Yield of leaf in Angelica gigas Nakai significantly increased until 100 days after transplanting. Production of leaf also tended to increase with increasing nitrogen fertilization. Model of regression equation showed that leaf production depended upon nitrogen ($Pr>{\mid}t{\mid}$ : 0.087, 0.256 and 0.079). Also, statistical results between nitrogen application level and production of dry-matter showed significant relationship (p<0.05) and contents of dry-matter was highest in 10 kg 10a-1 treatment on 24 Sep. Active compound isolated and purified from leaf and root of Angelica gigas Nakai was identified as DE and DA by gas chromatograph-mass spectrophotometry (GC-MS). Concentration of DA as prevalent compound in leaf was highest on 20 Aug. but decreased on 24 Sep. Amount of DE and DA accumulated in Angelica gigas Nakai significantly increased with growth stages and nitrogen level. The result of our investigation imply that nitrogen fertilization is important factor for production of leaf and accumulation of pyranocurmarine in Angelica gigas Nakai as a medicinal/food materials.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.125-130
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• 2019

This research is about alternative measure of main components for sprinkler system like automatic wet pipe sprinkler system, dry pipe sprinkler system, pre-action sprinkler system, vacuum sprinkler system, deluge sprinkler system, and so on. By replacing the alarm check valve, dry valve, pre-operated valve, and deluge open valve with a solenoid valve, it be can be simplifed the various processes of the manufacturing process into one process, it creates an environment in which one standardized product can be produced simultaneously on a single machine. Therefore, it could improve the price competitiveness of products, reduce the maintenance cost, and help the adaptability of new sprinkler systems in the future. There is a benefit when it comes to apply to sprinkler system. Only replace the valve which is used to control primary and secondary valve such as wet, dry, pre operated, vacuum, deluge system valve. Other components such as retarding chambers, automatic air compressors, accelerators or adjusters, supervisory panels, vacuum pumps, and manual starters can be used as they are, so they can be easily applied to existing sprinkler system. It is needed to legal and institutional study for solenoid valve applied sprinkler system to commercialize.

• Journal of the korean society of oceanography
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• v.33 no.3
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• pp.90-99
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• 1998

Butyltin and phenyltin residues were quantified in seawater and biota of the Chinhae Bay System, Korea in 1995. Butyltin compounds were detected in all seawater and biota samples, whereas phenyltin compounds were found only in the biota samples. Tributyltin (TBT) concentrations in seawater ranged from < 8-35 ng Sn/l. Tributyltin concentrations in Crassostyea gigas and Thais clavigera ranged from 95-885 and 23-414 ng Sn/g, respectively, Triphenyltin(TPhT) concentrations in each species ranged 155-678 and 46-785 ng Sn/g, respectively. Spatial distribution of TBT was closely related to boating and dry-docking activities. However, spatial distribution of TPhT was not consistent with that of TBT. The biological concentration factor for TBT in C. gigas was about 25000 that is four times greater than that of T. clavigera. Butyl- to phenyltin concentration ratio was greater than one in C. gigas, but that in T. clavigera was less than one. Major tissues of C. gigas also showed different accumulation patterns for butyl- and phenyltin compounds. Furthermore, 19 and 28% of total body burdens of TBT and TPhT were found in gonadal mass of C. gigas just prior to spawning.

• Animal cells and systems
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• v.7 no.4
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• pp.289-294
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• 2003

To quantify nutrient loading from emergent macrophytes through leaching in the littoral zones of Paldang Reservoir, we conducted incubation experiments using leaf litter of the emergent macrophyte, Zizaniz latifolia. To separate the leaching process from microbial decay, we used $HgCl_2$ to suppress microbial activity during the experiment. We measured electric conductivity, absorbance at 280nm, total nitrogen and dissolved inorganic nitrogen, total phosphorus and soluble reactive phosphorus, Na, K, Mg and Ca amounts in leaf litter and in water. In addition, we examined the effects of water temperature and ion concentrations of ambient water on the leaching process. A total of 6% of the initial ash-free dry mass of leaf litter was lost due to leaching during incubation (four days). Electric conductivity and A280 continued to increase and saturate during the incubation. To compare reaching rates of different nutrients, we fitted leaching dynamics with a hyperbolic saturation function [Y=AㆍX/(B+X)]. From these fittings, we found that ratios of leaching amounts to nutrient concentration in the litter were in the order of K > Na > Mg > P > Ca > N. Leaching from leaf litter of Z. latifolia was dependent on water temperature while it was not related with ion concentrations in the ambient water. Our results suggest that the leaching process of nutrients, especially phosphorus, from aquatic macrophytes provides considerable contribution to the eutrophication of the Paldang Reservoir ecosystem.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.65-70
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• 2010

This paper presents experimental performance evaluation of a magnetorheological (MR) damper for integrated isolation mount for ultra-precision manufacturing system. The vibration sources of the ultra-precision manufacturing system can be classified as follows: the one is the environmental vibration from the floor and the other is the transient vibration occurred from stage moving. The transient vibration occurred from the stage moving has serious adverse effect to the process because the vibration scale is quite larger than other vibrations. Therefore in this research, a semi-active MR damper, which can control the transient vibration, is adopted. Also the stage needs to be isolated from tiny vibrations from the floor. For this purpose, a dry-frictionless MR damper is required. In order to achieve this goal, a novel type of MR damper is originally designed and manufactured in this work. Subsequently, the damping force characteristics of MR damper are evaluated by simulation and experiment. In addition, the vibration control performance of the MR damper associated with the stage mass is evaluated.

• Structural Engineering and Mechanics
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• v.32 no.3
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• pp.399-406
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• 2009

A three-dimensional panel system, which was offered as a new method for construction in Jordan using relatively high strength modular panels for walls and ceilings, is investigated in this paper. The panel consists of two steel meshes on both sides of an expanded polystyrene core and connected together with a truss wire to provide a 3D system. The top face of the ceiling panel was pored with regular concrete mix, while the bottom face and both faces of the wall panels were cast by shotcreting (dry process). To investigate the structural performance of this system, an extensive experimental testing program for ceiling and wall panels subjected to static and dynamic loadings was conducted. The load-deflection curves were obtained for beam and shear wall elements and wall elements under transverse and axial loads, respectively. Static and dynamic analyses were conducted, and the performance of the proposed structural system was evaluated and compared with a typical three dimensional reinforced concrete frame system for buildings of the same floor areas and number of floors. Compressive strength capacity of a ceiling panel is determined for gravity loads, while flexural capacity is determined under the effect of wind and seismic loading. It was found that, the strength and serviceability requirements could be easily satisfied for buildings constructed using the three-dimensional panel system. The 3D panel system is superior to that of conventional frame system in its dynamic performance, due to its high stiffness to mass ratio.