• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.592-611
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• 2021

In this study a rarely available high-throughput cycling data set of 124 commercial lithium iron phosphate/graphite cells cycled under fast-charging conditions, with widely varying cycle lives ranging from 150 to 2,300 cycles including in-cycle temperature and per-cycle IR measurements. We worked out own Python codes which reproduced the various data plots and machine learning approaches for cycle life prediction using early cycles and more details not presented in the article and the supplementary information. Particularly, we applied regularized ridge, lasso and elastic net linear regression models using features extracted from capacity fade curves, discharge voltage curves, and other data such as internal resistance and cell can temperature. We found that due to the limitation in the quantity and quality of the data from costly and lengthy battery testing a careful hyperparameter tuning may be required and that model features need to be extracted based on the domain knowledge.

• 생태와환경
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• 제37권1호통권106호
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• pp.36-46
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• 2004

소규모 부영양 저수지에서 식물플랑크톤 성장에 대한 제한영양염과 N/P무게비의 영향을 평가하기 위해 2002년 11월부터 2003년 12월까지 이루어졌다. 조사기간 동안 수체 내 DIN/DTP과 TN/TP 무게비는 각각 17${\sim}$187,33${\sim}$60의 범위로 나타났다. 용존무기질소의 대부분은 질산성 질소($NO_3$-N)형태로 존재했으며, 봄에 일시적인 암모니아 농도의 증가가 나타났다. 반면에 무기인은 8.8${\sim}$0.6 ${\mu}g\;P\;L^{-1}$의 범위로 계절에 따른 변화는 적었으며, 용존총인은 26.5 ${\sim}$ 10.1 ${\mu}g\;P\;L^{-1}$로 8월에 가장 높았고 12월에 가장 낮은 농도를 나타냈다. 엽록소 a 농도는 28.8${\sim}$109.7 ${\mu}g\;L^{-1}$의 범위였고, 식물플랑크톤 세포밀도 변화와 유사한 계절적인 변화를 보였다. 봄에는 주로 규조류(Melosira varians)와 녹조류 (Dictyosphaerium puchellum)가 우점종으로 나타난 반면 5월부터 결빙 전까지는 Osillatoria SPP., Microcystis SPP., Aphanizomenon SP. 와 같은 남조류가 우점하였다. 남조류 군집 중 Microcystis SPP.가 우점한 6월부터 12월까지 수체 내 TN/TP비는 46${\sim}$13의 범위 (평균 27${\pm}$5)였다. 영양염 첨가실험의모든 경우(17번)에서 인에 의한 제한이 나타났으며, 질소제한은 8번에 걸쳐 나타났다. 식물플랑크톤 성장률은DIN/DTP비 30이하에서 가장 크게 나타났고, 인 농도50 ${\mu}g\;P\;L^{-1}$까지는 지속적으로 증가하였다. 절대 농도에 있어서 차이가 있으나, N/P비가 동일한 상태에서의 남조류 성장은 질소 농도가 3.5 mg N $L^{-1}$인 경우 N/P 비가 1인 상태에서 성장량이 가장 컸다. 인 첨가에 따른 성장은 질소농도가 높을수록 현저히 높게 나타났다. 이러한 결과들은 수체 내 질소농도가 높은 환경에서는 식물플랑크톤성장에 대한 강한 인 제한이 나타나기 쉬운 반면, 질소제한 가능성 이 상대적으로 적음을 의미한다.

• 환경영향평가
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• 제17권5호
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• pp.311-320
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• 2008

Reusing livestock manure have various advantages in securing soil organic resources, and since the costs needed for converting them into liquefied fertilizers are relatively moderate compared to normal treatment, such methods are necessary. In this study, the Recycling Capacity Assessment of Gyeonggi-do was carried out by comparing between the fertilizer demands for specific crops based on the cultivation areas and the amount of fertilizer resources that are generated from livestock manure. From this assessment, the possibility of obtaining resources by converting livestock manure into fertilizers were evaluated. The amount generated of Livestock Manure in Gyeonggi-do were evaluated by applying the emission units to the number of livestock manure. And from the amount generated of Livestock Manure, the amount of fertilizer produced from Livestock Manure were calculated by using the fertilizer a component rate. When considering the amount of fertilizer produced from Livestock Manure based on the type of livestock, N 6,626 ton/year, $P_2O_5$ 1,824 ton/year, $K_2O$ 4,480 ton/year were produced from milk cow manure, while N 5,247 ton/year, $P_2O_5$ 2,772 ton/year, $K_2O$ 2,879 ton/year, were produced from beef cattle manure. N 14,924 ton/year, $P_2O_5$ 7,205 ton/year, $K_2O$ 6,750 ton/year were produced from pigs and N 12,651 ton/year, $P_2O_5$ 4,458 ton/year, $K_2O$ 5,542 ton/year were produced by chickens. So the total amount of fertilizers that can be obtained from livestock manure were 3,668 ton/year Nitrogen, 16,259 ton/year phosphate and 19,651 ton/year kalium. And the total fertilizer demands in Gyeonggi-do were Nitrogen 27,200 ton/year, Phosphate 8,853 ton/year, and kalium 13,211 ton/year respectively. Nitrogen which had higher demands than production quantities were considered as limitation factors in crop growth. So the Recycling Capacity Assessment was carried out mainly based on Nitrogen. Since the Nitrogen quantities that can be provided by recycling livestock manure were 3,532 ton/year lesser than the Nitrogen demands, it is estimated that it would be desirable to convert livestock manure into resources. But in order to properly convert the entire livestock manure into organic resources, the seasonal situation that effects the nitrogen demands of crops along with the regional effects due to the industrial structures should be seriously analyzed. In addition, a system that can effectively produce and manage fertilizer should be established.

• 한국토양비료학회지
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• 제48권3호
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• pp.194-204
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• 2015

Six study sites in Gumi, Goryeong in Gyeongbuk province and Naju in Jeonnam province were selected to investigate soil properties of poorly drained horizons in paddy soils. The horizons were re-established layers which were parent material layers originated from fluvial deposits. Topsoil layers were differentiated from piled parent materials while soil structure of the topsoil layer was massive with striated microstructure. Compaction at soil re-establishment and a lack of structure and aggregate development in these soils may cause the limitation of vertical water movement and result in poorly drained horizons. Soil samples were taken from paddy fields with top soils of sandy loam, silt loam and silty clay loam and re-established soils of coarse and fine texture. The samples were taken from each horizon for the analyses of soil chemical and mineral properties. Soils with re-established soils of coarse texture had greater amounts of sands from top soil texture distributions, while soils with fine texture had greater amounts of silts. Chemical properties of top soils were analyzed from rice cultivated soils at the time of re-establishments and one year after the re-establishments. The coarse texture of the re-established horizons decreased in EC values from 0.23 to $0.11(dS\;m^{-1})$, available phosphate values from 112 to $54(mg\;kg^{-1})$, and exchangeable Ca values from 6.6 to $4.9(cmol_c\;kg^{-1})$. On the other hand, soils with fine texture showed decrease only in pH and exchangeable Ca values. Especially, organic matter and available phosphate contents showed heterogeneous distributions from each horizon. This result may be caused by mixture of plough layer and subsurface layer during and consolidation. Hydraulic conductivity values were low at the boundaries of top soil and parent material layers except SL/coarse soil. Soil microstructure was massive structure without soil clods or pores and showed striated structure. Therefore, re-established paddy fields with fluvial deposits as parent material layers showed limited vertical movements of soil water because of occurrence of compacted layers and less-development of soil clods and aggregates.

• 한국수산과학회지
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• 제35권5호
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• pp.455-461
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• 2002

1999년 3월부터 2001년 10월까지 섬진강 하구역에서 영양염의 DIN/DIP 비와 생물검정실험을 이용하여 식물플랑크톤 성장을 제한하는 영양염을 파악$\cdot$비교하였다. 조사기간 동안 용존무기질소와 인산 인의 비는 평균 14.7$\~$681.1의 범위로, 조사시작 지점인 난초도 주변 해역을 제외한 25 psu 이하 염분역과 엽록소 a의 농도가 매우 높았던 구간에서는 계절에 관계없이 N/P 비가 16 이상으로 매우 높아 식물플랑크톤의 성장을 조절하는 제한 영양염은 인산 인인 것으로 판단된다. 반면, 약 25 psu 이상의 염분역인 난초도 주변 해역은 광양만으로부터 공급되는 인산 인의 영향으로 인해 DIN/DIP 비는 16 이하로 낮아, 용존무기질소가 식물플랑크톤의 성장을 제한하는 것으로 판단된다. 섬진강 하구역에서의 DIN/DIP 비의 변화양상은 인산 인의 공급양상, 즉 육상으로부터 의 낮은 공급 및 광양만으로 부터의 높은 공급 그리고 시$\cdot$공간적인 식물플랑크톤의 성장에 의해 주로 영향을 받는 것으로 판단된다. Skeletonema costatum 및 nalassiosira rotula와 현장 식물플랑크톤을 이용한 생물검정실험 결과는 인산 인이 첨가된 배지에서 성장이 상대적으로 높게 나타나, 섬진강 하구역에서 식물플랑크톤을 조절하는 제한영양염은 인산 인인 것으로 검증되었다. S. costatum은 타종에 비해 염분 적응이 빠르고, 인산 인에 대해 반응이 크게 나타나, 섬진강 하구역에서 가을철에 우점율 $90\%$ 이상의 costatum bloom이 발생되는 주요 원인이었을 것으로 추측된다 현장식물플랑크톤을 이용한 생물검정실험에서는 배양시작 초기에 미량금속 첨가계에서 비교적 빠른 성장을 보였으며, 20일 이후에 는 인산 인 첨가계에서 월등한 성장을 보였다. 이는 주변 해수의 영양염 분석과 식물플랑크톤 현존량만으로는 판단하기 어려운, 영양염 이외의 미량금속 그리고 비타민 등의 성장제한 요인에 대한 정보를 얻을 수 있다는 것을 시사해 준다.

• Molecules and Cells
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• 제37권10호
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• pp.719-726
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• 2014

The ${\gamma}$-Aminobutyric acid (GABA) that is found in prokaryotic and eukaryotic organisms has been used in various ways as a signaling molecule or a significant component generating metabolic energy under conditions of nutrient limitation or stress, through GABA catabolism. Succinic semialdehyde dehydrogenase (SSADH) catalyzes the oxidation of succinic semialdehyde to succinic acid in the final step of GABA catabolism. Here, we report the catalytic properties and two crystal structures of SSADH from Streptococcus pyogenes (SpSSADH) regarding its cofactor preference. Kinetic analysis showed that SpSSADH prefers $NADP^+$ over $NAD^+$ as a hydride acceptor. Moreover, the structures of SpSSADH were determined in an apo-form and in a binary complex with $NADP^+$ at $1.6{\AA}$ and $2.1{\AA}$ resolutions, respectively. Both structures of SpSSADH showed dimeric conformation, containing a single cysteine residue in the catalytic loop of each subunit. Further structural analysis and sequence comparison of SpSSADH with other SSADHs revealed that Ser158 and Tyr188 in SpSSADH participate in the stabilization of the 2'-phosphate group of adenine-side ribose in $NADP^+$. Our results provide structural insights into the cofactor preference of SpSSADH as the gram-positive bacterial SSADH.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권1호
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• pp.19-25
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• 2011

Purpose: Addition of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) to grafting material has become widely accepted additively for bone regeneration because it can raise high expectations on it's clinical potential. The aim of this study was to evaluate the efficacy of PRP and PRF on early bone regeneration of rabbits when used in combination with beta tricalcium phosphate. Methods: In eight rabbits, the calvarium was exposed and the two marrows were penetrated. After then these artificial bone defects were augmented with ${\beta}$-TCP or ${\beta}$-TCP with PRP or ${\beta}$-TCP with PRF and covered. The animals were sacrificed after four and eight weeks. Histologic findings were observed under the light-microscope and histomorphometric analysis was performed by measuring calcified area of new bone formation within the CSD. Results: They demonstrated that new bone formation tended to be produced along the outline of graft materials. More amounts of newly bone was regenerated in ${\beta}$-TCP only and in combination of${\beta}$-TCP with PRF and it was statistically significant. In contrast, there was no significant difference between nothing apply and ${\beta}$-TCP with PRP groups in the relative amounts of newly mineralized bone. Conclusion: Within the limitation of this study, it can be concluded that PRF in combination with ${\beta}$-TCP showed a positive effect on bone regeneration and statistically it was significant.

• Ocean and Polar Research
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• 제35권2호
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• pp.147-155
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• 2013

The purpose of this study is to investigate seasonal difference in linear trends in satellite-derived chlorophyll-a concentration (Chl-a) and their related environmental changes in the South Sea of Korea (SSK) and East China Sea (ECS) for recent 15 years (Jan. 1998~Dec. 2012) by analyzing climatological data of Chl-a, Rrs(555), sea surface wind (SSW) and nutrient. A linear trend analysis of Chl-a data reveals that, during recent 15 years, the spring bloom was enhanced in most of the ECS, while summer and fall blooms were weakened. The increased spring (Mar. - May) Chl-a was associated with strengthened winter (Dec. - Feb.) wind that probably provided more nutrient into the upper ocean from the deep. The causes of decreased summer (Jun. - Aug.) Chl-a in the northern ECS were uncertain, but seemed to be related with the nutrient limitation. Recently (after 2006), low-salinity Changjiang diluted water in the south of Jeju and the SSK had lower phosphate that caused increase in N/P ratio with Chl-a decrease. The decreased fall (Sep. - Nov.) Chl-a was associated with weakened wind that tends to entrain less nutrient into the upper ocean from the deep. This study suggests that phytoplankton in the ECS differently changes in response to environmental changes depending on season and region.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.603-606
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• 2005

Ralstonia eutropha NCIMB 11599 and ATCC 17699 were grown, and their productions of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] compared. In flask cultures of R. eutropha NCIMB 11599, cell concentration, P(3HB-co-4HB) concentration and polymer content decreased considerably with increases in the ${\gamma}-butyrolactone$ concentration, and the 4HB fraction was also very low (maximum 1.74 mol%). In fed-batch cultures of R. eutropha NCIMB 11599, glucose and ${\gamma}-butyrolactone$ were fed as the carbon sources, under a phosphate limitation strategy. When glucose was fed as the sole carbon source, with its concentration controlled using an on-line glucose analyzer, 86% of the P(3HB) homopolymer was obtained from 201g/L of cells. In a two-stage fed-batch culture, where the cell concentration was increased to 104g/L, with glucose fed in the first step and constant feeding of ${\gamma}-butyrolactone$, at 6g/h, in the second, final cell concentration at 67h was 106g/L, with a polymer content of 82%, while the 4HB fraction was only 0.7mol%. When the same feeding strategy was applied to the fedbatch culture of R. eutropha ATCC 17699, where the cell concentration was increased to 42 g/L, by feeding fructose in the first step and ${\gamma}-butyrolactone$ (1.5g/h) in the second, the final cell concentration, polymer content and 4HB fraction at 74h were 51g/L, 35% and 32 mol%, respectively. In summary, R. eutropha ATCC 17699 was better than R. eutropha NCIMB 11599 in terms of P(3HB-co-4HB) production with various 4HB fractions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.159-160
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• 2006

A novel approach to the manufacture of biocompatible ceramic scaffold for tissue engineering using micro-stereolithography system is introduced. Micro-stereolithography is a newly proposed technology that enables to make a 3D micro structure. The 3D micro structures made by this technology can have accurate and complex shape within a few micron error. Therefore, the application based on this technology can vary greatly in nano-bio fields. Recently, tissue-engineering techniques have been regarded as alternative candidate to treat patients with serious bone defects. So many techniques to design and fabricate 3D scaffolds have been developed. But the imperfection of scaffold such as random pore size and porosity causes a limitation in developing optimum scaffold. So scaffold development with controllable pore size and fully interconnected shape have been needed for a more progress in tissue engineering. In this paper, bone scaffold was developed by applying the micro-stereolithography to the mold technology. The scaffold material used was HA(Hydroxyapatite) nano powder. HA is a type of calcium phosphate ceramic with similar characteristic to human inorganic bone component. The bone scaffold made by HA is expected, in the near future, to be an efficient therapy for bone defect.