• Journal of IKEEE
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• v.24 no.1
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• pp.132-139
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• 2020

The ionizer module used in this air cleaner supplies high voltages of 3.5KV / -4KV to the discharge electrode HV+ / HV- using a winding transformer to generate positive and negative ions by electric field radiation of carbon fiber brush. The ionizer module circuit using the existing MCU has the disadvantage of large PCB size and expensive price, and the gate driver chip using the existing ring oscillator has oscillation period sensitive to PVT (Process-Voltage-Temperature) fluctuation and there is risk of fire or electric shock because there is no fault detection function by short circuit of HV+ and GND as well as HV- and GND. Therefore, in this paper, even though PVT fluctuates, by using 7-bit binary up counter, HV+ voltage reaches the target voltage by adjusting oscillation period. And an HV+ short fault detection circuit for detecting a short circuit between HV+ and GND, an HV- short fault detection circuit for detecting a short circuit between HV- and GND, and an OVP (Over-Voltage Protection) for detecting that HV+ rises above an overvoltage are newly proposed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.73-78
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• 2005

Demand for the domestic hairy vetch seed production will be increased with the increasing interest of environment-friendly agriculture in Korea. This study was conducted during from 2000 fall to 2003 spring at upland field of National Institute of Crop Science in Suwon, Korea to compare wheat and triticale (TC) as stake crop of hairy vetch (HV), and to know proper seeding rates and ratios between TC and HV for the maximum HV seed production. As supporting crop of HV, TC was superior to wheat at the points of higher HV seed yield, stronger TC stalk for supporting, consistence of ripening stage of two seeds. In seeding method, row seeding was superior to broadcast seeding at the points of less lodging and higher HV seed yield. HV seed yield decreased with the increase of TC seeding rate in mixture cropping (row seeding), particularly at TC seeding rates over 5kg/10a. HV seed yield increased with the increase of HV seeding rate at the condition of TC seeding rates under 5kg/10a in spite of higher lodging of mixed crops at higher HV seeding rate due to higher HV aboveground dry matter. Maximum HV seed yield was obtained at TC seeding rate of $1\~1.5kg/10a$ as indicating HV seed yield 176kg/l0a (CV. Madison) at seeding rate of TC 1kg/10a + HV 2 kg/10a in 2001, and HV seed yield 96kg/10a (CV. Common) at seeding rate of TC 1.5kg/10a + HV 4.5kg/10a in 2003. Use of all-purpose combine harvester for harvesting and appliance for separation of mixed seeds using centrifugal force, which are prerequisite for HV seed production, was excellent in the simultaneous seeds production system of HV and TC.

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.537-544
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• 1998

The cultivation conditions of transformant Alcaligenes eutrophus AER5 harboring cloned phbC gene for mass production of poly (3-hydroxybutyrate-3-hydroxyvalerate)[P(3HB-3HV)] containing high molar fraction of 3-hydroxyvalerate (3-HV) were investigated. In two-stage batch cultivation, transformant accumulated P(3HB-3HV) containing 52.2 mol% of 3HV compared to 30 mol% of parent strain A. eutrophus H16. The increased 3-HV molar fraction was due to the amplified activity of PHB synthase participating in condensation of 3-HB and 3-HV. To increase efficiency of P(3HB-3HV) accumulation, fructose was added along with precursor compound valerate, and total cell mass and P(3HB-3HV) concentrations remarkably increased, but not 3-HV molar fraction. The effect of magnesium ion showed that P(3HB-3HV) concentration and 3-HV molar fraction were significantly increased upto 6.1 g/L and 71.3 mol% at 0.01 g/L of MgSO$_4$, respectively. The efficiency of several pH adjuster, NaOH, NaOH and (NH$_4$)$_2$SO$_4$, and NH$_4$OH, on total cell mass, p(3HB-3HV) concentration, and 3-HV molar fraction was also compared. To overcome the disadvantage of two-stage cultivation, one-stage intermittent fed-batch cultivation was attempted, such a way 10.0 g/L of fructose was supplied for cell growth at initial 36 hr and then 10.0 g/L of valerate and 5.0 g/L of fructose were applied to induce the accumulation of P(3HB-3HV), consequently, 10.4 g/L of P(3HB-3HV) with 38 mol% of 3-HV fraction could be obtained after 72 hr. These results can be used for elucidating cultivation strategy for mass production of P(3HB-3HV) containing high 3-HV molar fraction using transformant A. eutrophus AER5 harboring cloned phbC gene.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.43-48
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• 1998

No-tillage silage corn with legume hairy vetch(Vicia villosa Roth, HV) has renewed interest in supply of mineral N, soil erosion control at sloping land and weed control by cover of HV killed. This study was conducted to monitor concentration of soil mineral N ($NO_3^-$ -N + $NH_4^+$-N) and to find out variation of growth, yield and N uptake of silage corn according to quantity of HV cover; HV-removed, 1X-HV, 2X-HV at field of Crop Experiment Station in 1996. HV groM in early spring decreased the mineral N of soil depth 7.5 -22cm before corn seeding. But, killed HV cover increased the concentration of soil mineral N at surface soil (0-7.5cm) up to 45.4mglkg at early growth stage of corn. Dry matter(Dh4) of corn at harvest was lower in W-removed than in Okg FNlha. But DM and N uptake of corn at harvest were increased by quantity of HV-cover increasing liom HV-removed to 2X-HV. Hairy vetch could substitute N fertilizer for silage corn by N mineralized h m HV killed, but reduced early growth and N uptake of corn before silk by reducing soil mineral N of plow layer.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.3
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• pp.187-194
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• 2017

This study was conducted to investigate rice yield and soil chemical properties affected by incorporation levels of green barley (GB) and hairy vetch (HV). The GB and HV were applied to the pots at 500, 1,000, 1,500, and $2,000kg\;10^{-1}$ (GB500, GB1000, GB1500, GB2000, HV500, HV1000, HV1500, and HV2000, respectively), and inorganic fertilizer ($N-P-K=9-4.5-5.7kg\;10a^{-1}$) treatment as control. After rice harvesting, chemical properties of soil such as pH, OM, T-N, and available $P_2O_5$ in GB and HV treated treatments were improved over those in Control treatment. The rice yield ranged from 433 to $512kg\;10a^{-1}$ for GB treatments and 490 to $532kg\;10a^{-1}$ for HV treatments, indicating that rice yield was affected by incorporation levels of GB and HV. The rice yields in GB2000, HV1000, HV1500 and HV2000 treatments increased by 3.3, 3.1, 6.4 and 7.4% compared with Control treatment, respectively. Therefore, minimum incorporation level of GB and HV for increasing rice yield was $2,000kg\;10a^{-1}$ of GB and $1,000kg\;10a^{-1}$ of HV.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.5
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• pp.381-387
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• 2003

Winter hairy vetch (HV) can be used as green manure with conventional tillage system (CT), in which chemical N fertilizer required for cultivation of sub-sequent com could be fully saved, or as cover crop with no-tillage system (NT) in which soil could be protected from erosion, control of weed, and the reduction of N fertilizer application. This experiment was carried out to compare the enrichment of soil mineral nitrogen (SMN) at corn root zone, and the changes of com growth and N uptake according to HV amounts (winter fallow, above-ground HV removed, intact HV, and HV added from aboveground HV removed) under two tillage systems in the upland field of National Crop Experiment Station, Suwon, Korea in 1996. HV cultivation during winter decreased SMN a little at com planting. HV incorporation with CT increased SMN rapidly during early growth stage according to rapid decomposition of Hv. SMN by HV cover with NT was increased slowly and its increase was higher in the surface soil (soil layer 0-7.5cm) compared to deep soil layer 7.5-22cm. Com growth and N status at corn silking stage, com yield and N uptake at harvest were increased in proportion to aboveground HV amounts regardless of tillage system. Average hairy vetch nitrogen (HV-N) uptake efficiency by com was 10% higher with CT than with NT in which average HV-N uptake efficiency was 43 %. Corn yields were not different between two tillage systems, but corn N uptake was increased by 33 kgN/ha more with CT than with NT due to the increase of corn N concentration. The increase of SMN and com N uptake from HV cover with NT could not be disregarded though those with CT were higher than with NT

• KSBB Journal
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• v.11 no.5
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• pp.586-592
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• 1996

Poly(3-hydroxybutyric-co-3-hydroxyvaleric) acid(PHB/HV) copolymer synthesis by Pseudomonas sp. HJ from glucose and cosubstrate was investigated. Taxonomic analysis suggested that Pseudomonas sp. HJ was best marched to Pseudomonas picketti having 78.8% similarity. Pseudomonas sp. HJ produced PHB/HV copolymer containing 60.8 mol% HV and 44.9 mol% HV when supplied with hexadecane and propionic acid as a cosubstrate, respectively. The HV composition in PHB/HV copolymer was controlled by varying the concentration of hexadecane and propionic acid. Propionic acid added after 24 hours of incubation was incorporated as the HV monomer in the PHB/HV copolymer up to 49.6 mol%.

• Journal of Microbiology and Biotechnology
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• v.5 no.5
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• pp.292-296
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• 1995

Production of poly($\beta$-hydroxybutyrate-co-$\beta$-hydroxyvalerate)[poly(HB-co-HV) from glucose and propionic acid was studied in a two-stage fed-batch fermentation using Alcaligenes eutrophus NCIMB 11599. When either glucose became sufficient or the feeding rate of propionic acid decreased, production of poly(HB-co-HV) increased but concomitantly resulted in a reduced fraction of HV. During the copolymer accumulation stage, the specific production rate of hydroxyvalerate (HV) increased up to 0.013 (g-HV/g-RCM/h) but it decreased as propionic acid was accumulated. Control of the propionic acid concentration in the medium, therefore, is considered to be one of the most important operating parameters for production of poly(HB-co-HV) with a higher HV fraction. A high titre of poly(HB-co-HV) (85.6 g/I) with HV fraction of 11.4 mol$%$ could be obtained in 50 h by controlling the propionic acid concentration at 1 to 4 g/I.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.110-116
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• 2022

Polyhydroxyalkanoates (PHAs) are emerging as alternatives to plastics by replacing fossil fuels with renewable raw substrates. Herein, we present the construction of engineered Escherichia coli strains to produce short-chain-length PHAs (scl-PHAs), including the monomers 4-hydroxyvalerate (4HV) and 3-hydroxyvalerate (3HV) produced from levulinic acid (LA). First, an E. coli strain expressing genes (lvaEDABC) from the LA metabolic pathway of Pseudomonas putida KT2440 was constructed to generate 4HV-CoA and 3HV-CoA. Second, both PhaAB enzymes from Cupriavidus necator H16 were expressed to supply 3-hydroxybutyrate (3HB)-CoA from acetyl-CoA. Finally, PHA synthase (PhaC_Cv) from Chromobacterium violaceum was introduced for the subsequent polymerization of these three monomers. The resulting E. coli strains produced four PHAs (w/w% of dry cell weight): 9.1 wt% P(4HV), 1.7 wt% P(3HV-co-4HV), 24.2 wt% P(3HB-co-4HV), and 35.6 wt% P(3HB-co-3HV-co-4HV).

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.89-94
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• 2011

The wear characteristics between nonmetal and metals have been investigated using a disc on disc system. The specimens of nonmetal are made by the nylon and teflon materials. The specimens of the metal are used as eight kinds of along their hardness. The kinds of metals are copper(Hv96), aluminum(Hv186), brass(Hv234), aluminum bronze(Hv294), stainless steel(Hv327), annealing mild steel(Hv345), mild steel(Hv372), Hard steel(Hv434). In this study, a upper and lower specimens have been used the same size and shape. Using experimental data we figured the relationship between friction coefficient of nonmetal and metals. We figured the relationship between friction temperature of nonmetal and metals. The result had been verified a wear characteristics of nonmetal and metals in the wear tests.