• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.37-45
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• 2021

This study was conducted to evaluate the growth characteristics, phenolic concentration and antioxidant capacity of safflower (Carthamus tinctorius L.) and amaranth (Amaranthus spp.) sprout and investigate the possibility of using super absorbent polymer (SAP) as a medium in hydroponic cultivation in a plant factory. The control was used a commercial sprout cultivation tool (19 × 14 × 9 cm, W × D × L), and a treatment (SAP) was added on the cultivation tool to compare the effect of SAP. Safflower sprouts were immersed in a distilled water at 30 ℃ for 5 hours, and then grown in a plant growth chamber. The temperature and relative humidity were maintained at 25 ± 1℃ and 70 ± 4%, respectively. The light condition was maintained at 35 ± 6 μmol·m-2·s-1 (12h). Amaranth sprouts were grown in a plant growth chamber maintained with temperature of 25 ± 2℃, relative humidity of 70 ± 5% and light condition of 188 ± 10 μmol·m-2·s-1 (16h). A physical and chemical characteristic of SAP, and a germination rate, growth characteristics and secondary metabolites were analyzed in both safflower and amaranth. There was no significant effect on SAP in a germination rate, growth and secondary metabolites of safflower compared to the control, whereas amaranth grown under SAP was higher in germination rate, dry weight, phenolic concentration, and antioxidant capacity compared to the control. As a result, this study was suggested that cultivation of sprouts using SAP would be possible in a plant factory, and further studies on SAP on plant physiological response are required.

• Clean Technology
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• v.26 no.4
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• pp.329-335
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• 2020

Methanol synthesized from renewable hydrogen and captured CO2 has recently attracted great interest as a sustainable energy carrier for large-scale renewable energy storage. In this study, molten carbonate fuel cell's performance was investigated with the direct conversion of methanol into syngas inside the anode chamber of the cell. The internal reforming of methanol may significantly improve system efficiency since the heat generated from the electrochemical reaction can be used directly for the endothermic reforming reaction. The porous Ni-10 wt%Cr anode was sufficient for the methanol steam reforming reaction under the fuel cell operating condition. The direct supply of methanol into the anode chamber resulted in somewhat lower cell performance, especially at high current density. Recycling of the product gas into the anode gas inlet significantly improved the cell performance. The analysis based on material balance revealed that, with increasing current density and gas recycling ratio, the methanol steam reforming reaction rate likewise increased. A methanol conversion more significant than 90% was achieved with gas recycling. The results showed the feasibility of electricity and syngas co-production using the molten carbonate fuel cell. Further research is needed to optimize the fuel cell operating conditions for simultaneous production of electricity and syngas, considering both material and energy balances in the fuel cell.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.36-43
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• 2024

Fishing net waste (FNW) constitutes over half of all marine plastic waste and is a major contributor to the degradation of marine ecosystems. While current treatment options for FNW include incineration, landfilling, and mechanical recycling, these methods often result in low-value products and pollutant emissions. Importantly, FNWs, comprised of plastic polymers, can be converted into valuable resources like syngas and pyrolysis oil through pyrolysis. Thus, this study presents a process for generating high-purity hydrogen (H₂) by catalytically pyrolyzing FNW in a CO₂ environment. The proposed process comprises of three stages: First, the pretreated FNW undergoes Ni/SiO₂ catalytic pyrolysis under CO₂ conditions to produce syngas and pyrolysis oil. Second, the produced pyrolysis oil is incinerated and repurposed as an energy source for the pyrolysis reaction. Lastly, the syngas is transformed into high-purity H₂ via the Water-Gas-Shift (WGS) reaction and Pressure Swing Adsorption (PSA). This study compares the results of the proposed process with those of traditional pyrolysis conducted under N₂ conditions. Simulation results show that pyrolyzing 500 kg/h of FNW produced 2.933 kmol/h of high-purity H₂ under N₂ conditions and 3.605 kmol/h of high-purity H₂ under CO₂ conditions. Furthermore, pyrolysis under CO₂ conditions improved CO production, increasing H₂ output. Additionally, the CO₂ emissions were reduced by 89.8% compared to N₂ conditions due to the capture and utilization of CO₂ released during the process. Therefore, the proposed process under CO₂ conditions can efficiently recycle FNW and generate eco-friendly hydrogen product.

• Journal of the Korean Vacuum Society
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• v.15 no.6
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• pp.563-575
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• 2006

Ti(C,N) films are synthesized by pulsed DC plasma enhanced chemical vapor deposition (PEMOCVD) using metal-organic compounds of tetrakis diethylamide titanium at $200-300^{\circ}C$. To compare plasma parameter, in this study, $H_2$ and $He/H_2$ gases are used as carrier gas. The effect of $N_2\;and\;NH_3$ gases as reactive gas is also evaluated in reduction of C content of the films. Radical formation and ionization behaviors in plasma are analyzed in-situ by optical emission spectroscopy (OES) at various pulsed bias voltages and gas species. He and $H_2$ mixture is very effective in enhancing ionization of radicals, especially for the $N_2$. Ammonia $(NH_3)$ gas also highly reduces the formation of CN radical, thereby decreasing C content of Ti(C, N) films in a great deal. The microhardness of film is obtained to be $1,250\;Hk_{0.01}\;to\;1,760\;Hk_{0.01}$ depending on gas species and bias voltage. Higher hardness can be obtained under the conditions of $H_2\;and\;N_2$ gases as well as bias voltage of 600 V. Hf(C, N) films were also obtained by pulsed DC PEMOCYB from tetrakis diethyl-amide hafnium and $N_2/He-H_2$ mixture. The depositions were carried out at temperature of below $300^{\circ}C$, total chamber pressure of 1 Torr and varying the deposition parameters. Influences of the nitrogen contents in the plasma decreased the growth rate and attributed to amorphous components, to the high carbon content of the film. In XRD analysis the domain lattice plain was (111) direction and the maximum microhardness was observed to be $2,460\;Hk_{0.025}$ for a Hf(C,N) film grown under -600 V and 0.1 flow rate of nitrogen. The optical emission spectra measured during PEMOCVD processes of Hf(C, N) film growth were also discussed. $N_2,\;N_2^+$, H, He, CH, CN radicals and metal species(Hf) were detected and CH, CN radicals that make an important role of total PEMOCVD process increased carbon content.

• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.413-426
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• 2010

This study was conducted to investigate the effects on fermentation characteristics of rumen microorganism by different types and levels of lignosulfonate treated soybean meal (LSBM) in in vitro test and rumen simulation continuous culture (RSCC) system in dairy cows. The experiment I was control and 12 treatments (each with 3 replications) in vitro test to demonstrate composition of different types of treatments with lignosulfonate (Desulfonate, Na, Ca and solution) and levels (2, 4 and 8%) of soybean meal in the dairy cow diet. LSBM source treatments in the dairy cow diet showed pH value, $NH_3$-N concentration and total VFA concentration lower than control at all levels and incubation times (p<0.05). Dry matter digestibility of LSBM source treatments showed lower than control (p<0.05). Gas production and rumen microbial synthesis was decreased by rumen microbial fermentation for incubation times. Undegradable protein (UDP) concentration of all LSBM treatments was decreased for incubation times, and significantly higher than control (p<0.05). In the experiment II compared diets of the control, LSBM Na 2%, LSBM Sol 2%, which are high performance to undegradable protein (UDP) concentration experiment I in vitro test, and heated treatment lignosulfonate (LSBM Heat) 2% in the dairy cow diet from four station RSCC system ($4{\times}4$ Latin square). A rumen microbial fermentation characteristic was stability during 12~15 days of experimental period in all treatments. The pH value of LSBM treatments was higher than control treatment (p<0.05). The $NH_3$-N concentration, VFA concentration and rumen microbial synthesis of LSBM treatments were lower than control (p<0.05). The undegradable protein (UDP) showed LSBM Na 2% (45.28%), LSBM Sol 2% (43.52%) and LSBM Heat 2% (43.49%) higher than control (41.55%), respectively (p<0.05). Those experiments were designed to improve by-pass protein of diet and milk protein in the dairy cows. We will conduct those experiments the in vivo test by LSBM treatments in dairy cows diet.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.165-174
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• 1998

The turnover of collagen is controlled by the balance between collagen synthesis and degradation. The production of collagenase (matrix metalloproteinase-1) and its inhibitor, tissue inhibitor of matrix metallopmteinase-1 (TIMP-1) are one of the substances which regulate this balance. The periodontal ligament fibroblast plays an important role in collagen metabolism during orthodontic treatment and is believed to be an origin of the osteoblast in the alveolar bone. The collagenase secreted by the periodontal ligament fibroblast and the osteoblast initiates the bone resorption by removing the osteoid layer in the alveloar bone. The interleukin-$1{\beta}$ is secreted by the macrophage during orthodontic treatment. The present study was undertaken to assess the effect of mechanical stress and interleukin-$1{\beta}$ on the expression of collagenase and TIMP-1 in the periodontal ligament fibroblasts using reverse transcription polymerase chain reaction and immunohistochemical staining. The periodontal ligament fibroblasts were stitched by placing the $Petriperm dish^{\circledR}$ dish on the top of spheroidal convex watch glass ($5\%$ surface increase) and tented with interleukin-$1{\beta}$ (1.0 ng/ml), or treated with both of them. Treatment with mechanical stress and/or interleukin-$1{\beta}$ resulted in increased collagenase mRNA expression. The mechanical stress treated group (1.61, 1.62, 1.37 fold increase), the interleukin-$1{\beta}$, tented group (1.68, 1.60, 3.78 fold increase), the mechanical stress and interleukin-$1{\beta}$ treated group (1.89, 1.72, 5.48 fold increase) induced increases in collagenase mRNA compared with the control group after 2, 4, 8 hours respectively. But TIMP-1 mRNA expressions at experimental groups were decreased after 2, 4 hours and increased after 8 hours. The mechanical stress treated group (0.16, 0.49 fold decrease and 3.77 fold increase), the interleukin-$1{\beta}$ treated group (0.15,0.44 fold decrease and 4.46 fold increase), the mechanical stress and interleukin-$1{\beta}$ tented group (0.15, 0.69 fold decrease and 4.81 fold increase) induced changes in TIMP-1 mRNA compared with the control group after 2, 4, 8 hours, respectively. Immunohistochemical stain showed that increased collagenase and TIMP-1 staining of the mechanical stress tented group, the interleukin-$1{\beta}$ treated group, and the mechanical stress and interleukin-$1{\beta}$ treated group compared with that of the control group after 8 hours. These findings suggest that mechanical stress and interleukin-$1{\beta}$ regulate expression of collagenase and TIMP-1.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.877-887
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• 1996

The ideal membranes for membrane-covered oxygen probes system should be selectively permeable for oxygen and chemically inert, and have good mechanical strength. Polysulfone(PSf) was selected to develop the membrane for membrane-covered oxygen electrodes system. PSf membranes have properties such as good reproducibility, good mechanical strength, chemical inertness, and high heat resistance. PSf membranes were cast from polymer solution on the glass plate at constant temperature, and casting solvents used were tetrahydrofuran(THF), methylene chloride, and N-methyl-2-pyrrolidone(NMP). Tricresyl phosphate(TCP) as plasicizer was added to PSf to increase the softness of membrane. The permeation characteristics were observed for pure oxygen and nitrogen through pure PSf membranes by variable volume method and membrane-covered electrode system. The permeability coefficients of oxygen and nitrogen measured by variable volume method were slightly decreased with increasing of upstream pressure. The permeation properties of PSf membrane using methylene choride as casting solvent were not affected by the PSf amount of polymer solution. The permeability coefficients of oxygen and nitrogen for PSf membrane containing TCP were very slightly lower than those for pure PSf membrane, but ideal separation factors were slightly higher. The flexibility of PSf membrane containing 2wt% TCP was better than that of pure PSf membrane. It was expected that this increase in flexibility would solve the difficulty of fixing the membrane to the cathode. The membrane-covered oxygen probes system was composed of anode, cathode and electrolyte. The type of the anode was Ag/AgCl half-cell, that of cathode was Ag, and the electrolyte was 4N KCl solution. The result of sampled current voltametry for PSf membrane showed the plateu region at -0.3V~-1.0V. The correlation coefficient of oxygen partial pressure versus current for PSf membrane was relatively high, 0.99949. It was concluded that PSf membrane was the good candidate for the membrane-covered oxygen probes system.

• Clean Technology
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• v.22 no.1
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• pp.16-28
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• 2016

Textile industry is considered as one of the most polluting sectors in terms of effluent composition and volume of discharge. It is well known that the effluents from textile dying industry contain not only chromatic substances but also large amounts of organic compounds and insolubles. The azo dyes generate huge amount of pollutions among many types of pigments. In general, the electrochemical treatments, separating colors and organic materials by oxidation and reduction on electrode surfaces, are regarded as simpler and faster processes for removal of pollutants compared to other wastewater treatments. In this paper the electrochemical degradation characteristics of dye wastewater containing CI Direct Blue 15 were analyzed. The experiments were performed with various anode materials, such as RuO₂/Ti, PtO₂/Ti, IrO₂/Ti and graphite, with stainless steel for cathode. The optimal anode material was located by changing operating conditions like electrolyte concentration, current density, reaction temperature and initial pH. The degradation efficiency of dye wastewater increased in proportion to the electrolyte concentration and the current density for all anode materials, while the temperature effect was dependent on the kind. The performance orders of anode materials were RuO₂/Ti > PtO₂/Ti > IrO₂/Ti > graphite in acid condition and RuO₂/Ti > IrO₂/Ti > PtO₂/Ti > graphite in neutral and basic conditions. As a result, RuO₂/Ti demonstrated the best performance as an anode material for the electrochemical treatment of dye wastewater.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.944-948
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• 1999

The morphological properties of four binary blends of polyethylene synthesized by metallocene catalyst(MCPE) and four polyolefins prepared by Ziegler-Natta catalyst have been investigated to interpret the effect of micro-molecular structure on the phase morphology and interfacial behavior; four binary blend systems studied are high density polyethylene(HDPE)-metallocene polyethylene (MCPE), polypropylene(PP)-MCPE, poly(propylene-co-ethylene) (CoPP)-MCPE, and poly(propylene-co-ethylene-co-1-butylene) (TerPP)-MCPE, and they are all phase separated. The HDPE-MCPE blend shows evenly growing homogeneous HDPE domain on the continuous MCPE phase, on the other hand, the rest of three blends show complex heterogeneous phase behavior. The PP-MCPE blend shows that PP and MCPE and completely phase separated and phase inversion takes place at 50% MCPE. The CoPP-MCPE and TerPP-MCPE show enhanced interface due to the same micro-molecular structure of ethylene, and phase inversion takes place at 40% MCPE. In particular, TerPP-MCPE blend shows improved phase morphology between interfaces, and this may be arisen from the comonomer contents in TerPP, which are 1-butene and ethylene having the same chemical structure as that of MCPE. The enhancement of the phase morphology in the TerPP-MCPE blend is correlated with the mechanical and morphological properties. Thus, although the four blend systems are phase separated, the phase morphology suggests that the order of interfacial adhesion strength be HDPE-MCPE > TerPP-MCPE > CoPP-MCPE > PP-MCPE and that micro-molecular structure between constituents be one of major factors giving enhanced interfacial adhesion.

• Clean Technology
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• v.26 no.2
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• pp.137-144
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• 2020

Metal-impregnated activated carbons were prepared via ultrasonic-assisted impregnation method for regeneration and low ammonia concentration. Magnesium and copper were selected as metals, while chloride (Cl^-) and nitrate (NO₃^-) precursors were used to impregnate the surface of activated carbon. The physical and chemical properties of the prepared adsorbents were characterized by TGA, BET, and NH₃-TPD. The ammonia breakthrough test was carried out using a fixed bed and flowing ammonia gas (1000 mg L^-1 NH₃, balanced N₂) at 100 mL min^-1, under conditions of temperature swing adsorption (TSA) and pressure swing adsorption (PSA, 0.3, 0.5, 0.7, 0.9 Mpa). The adsorption and desorption performance of ammonia were in the order of AC-Mg(Cl) > AC-Cu(Cl) > AC-Mg(N) > AC-Cu(N) > AC through NH₃-TPD and TSA and PSA processes. AC-Mg(Cl) using MgCl₂ showed the average adsorption amount of 2.138 mmol/g at TSA process. Also, AC-Mg(Cl) showed the highest initial adsorption amount of 3.848 mmol/g at PSA 0.9 Mpa. When metal impregnated the surface of the activated carbon, it was confirmed that not only physical adsorption, but also chemical adsorption increased, making enhancement in adsorption and desorption performances possible. Also, the prepared adsorbents showed stable adsorption and desorption performances despite repeated processes, confirming their applicability in the TSA and PSA processes.