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Maximizing biomass utilization: An integrated strategy for coproducing multiple chemicals

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Journal of Energy Chemistry 2025年第1期100卷 180-191页

作者： Byeongchan ahn Sua Jo Jonggeol Na J.Jay Liu young-Ju Kim Wangyun Won Department of Chemical and Biological Engineering Korea University Department of Chemical Engineering (Integrated process) Kyung Hee University Department of Chemical Engineering and Materials Science Ewha Womans University Department of Chemical Engineering Pukyong National University Resources Engineering Plant Research Department Korea Institute of Geoscience and Mineral Resources

Lignocellulosic biomass is one of the viable solutions to alleviate the global warming. However, the limited utilization of biomass majorly focused on cellulose and hemicellulose restricts the economic and environmental feasibilities. To cope with this issue, we proposed an integrated process of co-producing 1,6-hexanediol（1,6-HDO） with tetrahydrofuran and adipic acid from biomass, referred to as Strategy A. To compare the impacts of lignin upgrading and feedstock, Strategy B, which co-produces tetrahydrofuran alone, and Strategy C, which is the traditional route to produce 1,6-HDO from fossil fuels, were used. Heat networks are also designed to reduce operating costs and indirect carbon emissions due to energy consumption, saving 87% and 83% of the heat and cooling requirements, respectively, in Strategy A. The market competitiveness of Strategy A was evaluated by determining the minimum selling price through techno-economic analysis, and sustainability was thoroughly investigated by quantifying the environmental impacts through both midpoint and endpoint life-cycle assessments（LCAs）.Strategy A was found to be the most favorable both economically（USRDSCHARDOLLAR3,402/ton） and environmentally（-26.9 kg CO2eq.）. This indicates that lignin valorization is not only economically but also environmentally preferred. Finally, changes in economic and environmental feasibilities depending on economic, process, and environmental parameters were investigated using sensitivity and uncertainty analyses. The results of these analyses provide valuable insight into bio-based chemical production.

关键词： Biorefinery Carbon mitigation Climate change Global warming Lignin utilization Bioeconomy

Extraction and Purification of Depigmenting Agents from Chinese Plants

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Chemical Research in Chinese Universities 2006年第2期22卷 162-167页

作者： ahn So-young ROW Kyung-ho KIM eun-ki School of Chemical and Biological Engineering Center for Advanced Bioseparation Technology Inha University Nam-Ku Incheon 402-751 Korea

Depigmenting agents were solvent-extracted and purified by preparative and analytical HPLC from three Chinese plants; Chrysanthemum morifolium Ramat（ Xizang Caijuhua）, Rhodiola sachalinensis, and Terminalia chebula Retzius. Four fractions obtained from the ethyl ether layer of C. m. Rama and two fractions from the ethyl acetate layer of Rhodiola salientness show depigmenting effects. At 8 200, the ethyl acetate layers of Chrysanthemum morifolium Ramat, Rhodiola sachalinensis and the methanol extract of Terminalia chebula Retzius, can inhibit the melanin production of mouse B16 melanoma cells by 92%, 60% and 90%, respectively, whereas 46% inhibition was observed by commercially available depigmenting agents（arbutin）. These results show the potential of these three Chinese plants as a novel resource for depigmenting agents in the cosmetic industry.

关键词： Chrysanthemum Morifolium Ramat Rhodiola Sachalinensis Terminalia Chebula Retzius Melanin Inhibitory Effect HPLC

Effect of carrier gas species on the microstructure and compressive deformation behaviors of ultra-strong pure copper manufactured by cold spray additive manufacturing

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Journal of Materials Science & Technology 2022年第2期97卷 264-271页

作者： young-Kyun Kim Kee-ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea

Cold spray(CS)which has recently become a promising additive manufacturing(AM)technology,was used to fabricate ultra-strong pure *** addition,the effects of carrier gas species on the microstructural characteristics,mechanical properties and deformation mechanisms were systemically *** CSAM copper manufactured with N_(2) carrier gas reveals a heterogeneous bimodal microstructure consisting of ultra-fine grains at the particle interface and relatively coarse grains in inner *** He carrier gas,a homogeneous grain structure consisting of ultra-fine grains in most areas was *** tests showed that N_(2) and He carrier gasses enabled ultra-high yield strengths of 340 and415 MPa,*** values are comparable to severely plastic deformed copper,which has extremely low ductility and shape *** the other hand,both samples showed a strain-softening phenomenon that does not commonly occur at room *** deformation microstructures revealed that dynamic recovery(DRV)and dynamic recrystallization(DRX)phenomena were generated despite being deformed at room *** on the above findings,the overall deformation mechanisms according to the carrier gas species in the CSAM copper manufacturing process were ***,the work hardening and softening behaviors of CSAM Cu are predicted by using a constitutive equation.

关键词： Cold spray additive manufacturing Carrier gas Pure Cu Mechanical properties Deformation behavior

Stabilized sub-grain and nano carbides-driven 1.2 GPa grade ultra-strong CrMnFeCoNi high-entropy alloy additively manufactured by laser powder bed fusion

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Journal of Materials Science & Technology 2022年第22期117卷 8-22页

作者： young-Kyun Kim Kee-ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Institute of Materials Science(KIMS) Changwon 51508Republic of Korea

High-entropy alloys(HEAs)with interstitial atoms that are produced by additive manufacturing have gained intensive interest in the materials science community because of their suitability for constructing high-strength net-shape ***,a strategy to additionally enhance the strength of selective laser melted carbon-containing HEAs was *** as-built carbon-containing HEAs(C_(x)(Cr_(20)Mn_(20)Fe_(20)Co_(20)Ni_(20))_(100-x)(x=0.5 at.%,1.0 at.%,and 1.5 at.%))contain supersaturated carbon,and the extent of supersaturation increases as the carbon content *** subjected to aging treatment at 650°C for 1 h,the microstructure of the three alloys did not change at the grain ***,the microstructure at the sub-grain scale changed markedly,and these changes influenced the tensile properties and deformation *** particular,the tensile strength of aged 1.5C-HEA at 650°C was∼1.2 GPa at room temperature,which is higher than those reported for CrMnFeCoNi ***,the main deformation mechanism changed from deformation twinning to dislocation-mediated slip,resulting in much higher strain hardening capacity after the aging *** work led to the development of an alternative promising method that involves tailoring the microstructure,to enhance the mechanical properties of additively manufactured metallic materials that contain interstitial atoms.

关键词： Selective laser melting High-entropy alloy Carbon contents Aging Microstructure evolution Tensile property Deformation mechanism

Effect of Ni and Mn on the Mechanical Properties of 22Cr Microduplex Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2015年第1期28卷 32-38页

作者： Jun-young Park Yong-Sik ahn Department of Materials Science and Engineering Pukyong National University

The tensile properties of 22Cr–2Ni–4Mn–0.2N micro-duplex stainless steels with different Ni and Mn contents were investigated. Duplex stainless steels were vacuum induction melted and hot rolled, then annealed at 1,000–1,100 °C, at which temperature both the austenite and ferrite phases were stable. The volume fraction of the ferrite phase was markedly affected by the alloying elements of Mn and Ni; 1 wt% of Mn was equivalent to 0.4 wt% of Ni. All of the steels tested at room temperature showed the common strain-hardening behavior, while the steels tested at lower temperatures（-30 or-50 °C）showed a distinct inflection point in their stress–strain curves, which resulted from the transformation of the austenite to straininduced martensite. The onset strain（e0） of the inflection point in the stress–strain curve depended on the Md30 value of the steel. Testing at lower temperatures resulted in smaller e0 and consequently higher strengths and fracture strains（ef）. The tensile behavior was examined from the perspective of austenite stability of the micro-duplex stainless steels with the different Ni and Mn contents.

关键词： Duplex stainless steel Microstructure Mechanical property Alloy composition

Efficacy of uncovered self-expandable metallic stent for colorectal obstruction by extracolonic malignancy

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World Journal of Gastrointestinal Oncology 2020年第9期12卷 1005-1013页

作者： Joon Seong ahn Sung Noh Hong Dong Kyung Chang young-Ho Kim eun-Ran Kim Department of Internal Medicine Samsung Medical CenterSungkyunkwan University School of MedicineSeoul 06351South Korea

BACKGROUND Self-expandable metallic stent(SEMS)is widely used for malignant colorectal ***,SEMS has been used for palliative option for colorectal obstruction caused by extracolonic malignancy(ECM).AIM To evaluate the efficacy of SEMS for colorectal obstruction caused by ECM,and to identify the factors associated with stent *** Seventy-two patients who were treated with uncovered SEMS insertion for malignant colorectal obstructions caused by colorectal metastasis or peritoneal seeding of ECM at Samsung Medical Center between April 2012 to March 2016 were *** analyzed technical and clinical outcomes of stent insertion,the factors associated with stent occlusion and long term outcomes after stent *** Technical success rate was determined as 90.3%with a clinical success rate of 87.7%.Stent occlusion developed in 28.1%,with a median duration of 51 ***,81.3%with stent occlusion could be treated with secondary stent *** failure was observed to be related to the male sex(P=0.020)and right colon obstruction(P=0.017).Stent length≤10 cm was found to be associated with stent occlusion(P=0.003).Median survival time after stent insertion was 4.7 mo and 40.4%were able to receive their oncological treatments after stent insertion without *** Uncovered SEMS is effective for the treatment of colorectal obstruction caused by ECM,considering life expectancy of patients with ECM.

关键词： Self-expandable metallic stent Colorectal stent Colorectal obstruction Extracolonic malignancy Retrospective study

Integration of earth-abundant cocatalysts for high-performance photoelectrochemical energy conversion

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Journal of Energy Chemistry 2024年第1期88卷 336-355,I0008页

作者： Joonhee Ma Sang Hyun ahn Soo young Kim Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea School of Chemical Engineering and Materials Science Chung-Ang University84 Heukseok-roDongjak-guSeoul 06974Republic of Korea

Photoelectrochemical(PEC)energy conversion has emerged as a promising and efficient approach to sustainable energy harvesting and *** utilizing semiconductor photoelectrodes,PEC devices can harness solar energy and drive electrochemical reactions such as water splitting or carbon dioxide(CO_(2))reduction to generate clean fuels and value-added ***,PEC energy conversion faces several challenges such as high overpotential,sluggish reaction kinetics,charge carrier recombination,and stability issues,which limit its practical ***,significant research has been conducted to improve the overall conversion efficiency of PEC *** particularly promising approach is the use of cocatalysts,which involves introducing specific cocatalysts onto the photoelectrode surface to promote charge separation,improve reaction kinetics,and reduce the overpotential,thereby enhancing the overall performance of PEC energy *** review provides a comprehensive overview of the recent developments in the earth-abundant cocatalysts for PEC water splitting and CO_(2) *** main earth-abundant catalysts for the PEC water splitting include transition-metal dichalcogenide(TMD)-based materials,metal phosphides/carbides,and metal oxides/***,PEC-CO_(2)RR was divided into C_(1) and C_(2+)based on the final product since various products could be produced,focusing on diverse earth-abundant materials-based *** addition,we provide and highlight key advancements achieved in the very recent reports on novel PEC system design engineering with ***,the current problems associated with PEC systems are discussed along with a suggested direction to overcome these obstacles.

关键词： Solar energy Photo-electrochemical Water splitting CO_(2)reduction Cocatalysts

Reconstruction of Rabbit Corneal Layer Composed of Corneal Fibroblasts and Corneal Epithelium on the Lyophilized Amniotic Membrane

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Chemical Research in Chinese Universities 2006年第2期22卷 150-156页

作者： ahn Jae-il JANG In-keun YOON Mun-young SEO young-kwon YOON Hee-hun KIN Jae-chan SONG Kye-yong YANG eun-kyung PARK Jung-keug Department of Chemical and Biochemical Engineering Dongguk University Seoul Korea Department of Ophthalmology Chung-Ang University Hospital Seoul Korea Department of Pathology College of Medicine Chung-Ang University Seoul Korea R & D Center Bioland Ltd. Chun-An Korea

Many researchers have employed the cryopreserved amniotic membrane（CAM） and corneal epithelial cells in the treatment of a severely damaged burned cornea, with corneal epithelial cells cultured on an amniotic membrane （AM）. The lyophilized amniotic membrane（LAM） has a higher graft take and a longer shelf life; it is easier to store and safer because of gamma irradiation. Two Teflon rings（ ahn＇s supporter） were made for culturing the cells on the LAM, and were then used to support the LAM. To reconstruct a corneal layer composed of corneal fibroblasts and epithelium, the corneal fibroblasts were first cultivated on the stromal side of LAM for five days, foUowed by epithelial cells culture on the epithelial side, by using the air-liquid interface culture. The reconstructed corneal layer composed of corneal fibroblasts and corneal epithelial cells has a much healthier basal layer of corneal epithelium than the reconstructed corneal epithelium, which was got by using only corneal epithelial cells, and resembles the epithelium of normal corneas, without the horny layer. Thus, the reconstruction of the corneal layer by using a LAM is considered to be a good in vitro model, not only for its application in toxicological test kits, but also for transplantation in patients with a severely damaged cornea.

关键词： Lyophilized amniotic membrane Corneal layer Corneal fibroblast Corneal epithelium

Anti-senescence and anti-wrinkle activities of 3-bromo-4,5-dihydroxybenzaldehyde from Polysiphonia morrowii Harvey in human dermal fibroblasts

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Asian Pacific Journal of Tropical Biomedicine 2021年第2期11卷 74-80页

作者： Su-Hyeon Cho eun-Yi Ko Soo-Jin Heo Seo-young Kim Juhee ahn Kil-Nam Kim Chuncheon Center Korea Basic Science InstituteChuncheon 24341Republic of Korea Bio research Center DermaproJeju 63309Republic of Korea Jeju Marine Research Center Korea Institute of Ocean Science&TechnologyJeju 63349Republic of Korea Department of Medical Biomaterials Engineering College of Biomedical SciencesKangwon National UniversityChuncheon 24341Republic of Korea

Objective:To investigate the anti-senescence effect of 3-bromo-4,5-dihydroxybenzaldehyde(BDB)from Polysiphonia morrowii Harvey in human dermal fibroblasts(HDF).Methods:HDF were subjected to treatment of BDB and then treated with hydrogen peroxide(H2O2)to induce premature ***-associatedβ-galactosidase(SA-β-gal)activity in HDF was determined using the SA-β-gal staining *** reactive oxygen species(ROS)production was measured using the 2’,7’-dichlorodihydrofluorescein diacetate *** blotting assay was performed to assess the level of antioxidant enzyme glutathione peroxidase 1(GPX1).In addition,intracellular collagen and collagenase contents were analyzed using the respective ELISA *** activity in HDF supernatants was measured from p-nitroaniline release and normalized using total protein ***:Treatment of HDF with H2O2 increased the activity of SA-β-gal,but BDB pre-treatment resulted in the reduction of SA-β-gal ***,BDB significantly reduced H2O2-induced intracellular ROS *** also markedly increased the level of GPX1,which was inhibited by 400μM of ***,in in vitro study,BDB significantly increased intracellular collagen content and decreased matrix metalloproteinase-1 and elastase activities in ***:Our results demonstrate that BDB shows antisenescence and anti-wrinkle activities in vitro.

关键词： Polysiphonia morrowii Harvey 3-bromo-4,5-dihydroxybenzaldehyde Oxidative stress Human dermal fibroblast Anti-senescence activity Anti-wrinkle activity