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Jang HS, Kim SH, Park GW, Jeon JB, Kim D, Kim D, Kim WR, Choi YS, Shin S. Process Parameter Optimization for Laser Powder Bed Fusion of Fe-Si Alloy Considering Surface Morphology and Track Width of Single Scan Track. Materials (Basel) 2023; 16:7626. [PMID: 38138769 PMCID: PMC10744533 DOI: 10.3390/ma16247626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/30/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
A laser power bed fusion (L-PBF) manufacturing process was optimized by analyzing the surface morphology and track width w of single scan tracks (SSTs) on Fe-3.4wt.%Si. An SST was evaluated under process conditions of laser power P, scan speed V, and energy density E = P/V. The SST surface shape was mainly affected by E; desirable thin and regular tracks were obtained at E = 0.3 and 0.4 J/mm. An L-PBF process window was proposed considering the optimal w of SST, and the appropriate range of E for the alloy was identified to be 0.24 J/mm to 0.49 J/mm. w showed a strong relationship with E and V, and an analytic model was suggested. To verify the process window derived from the appropriate w of SST, cubic samples were manufactured with the estimated optimal process conditions. Most samples produced had a high density with a porosity of <1%, and the process window derived from SST w data had high reliability. This study presents a comprehensive approach to enhancing additive manufacturing for Fe-3.4Si alloy, offering valuable insights for achieving high-quality samples without the need for time-intensive procedures.
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Affiliation(s)
- Ho Sung Jang
- Advanced Forming Process R&D Group, Korea Institute of Industrial Technology, Ulsan 44776, Republic of Korea; (H.S.J.)
- School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Su Heon Kim
- Advanced Forming Process R&D Group, Korea Institute of Industrial Technology, Ulsan 44776, Republic of Korea; (H.S.J.)
- School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Geon-Woo Park
- Dongnam Regional Division, Korea Institute of Industrial Technology, Yangsan 50623, Republic of Korea
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Jong Bae Jeon
- Department of Materials Science and Engineering, Dong-A University, Busan 49315, Republic of Korea
| | - Donghwi Kim
- Computational Materials Research Team, Hyundai Motor Group, Uiwang 16082, Republic of Korea
| | - Dohyung Kim
- Dongnam Regional Division, Korea Institute of Industrial Technology, Yangsan 50623, Republic of Korea
| | - Wang Ryeol Kim
- Dongnam Regional Division, Korea Institute of Industrial Technology, Yangsan 50623, Republic of Korea
| | - Yoon Suk Choi
- School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Sunmi Shin
- Advanced Forming Process R&D Group, Korea Institute of Industrial Technology, Ulsan 44776, Republic of Korea; (H.S.J.)
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Saini RK, Ahn HY, Park GW, Shin JW, Lee JH, Yu JW, Song MH, Keum YS, Lee JH. Quantitative Profiling of Carotenoids, Tocopherols, Phytosterols, and Fatty Acids in the Flower Petals of Ten Marigold ( Tagetes spp. L.) Cultivars. Foods 2023; 12:3549. [PMID: 37835202 PMCID: PMC10572322 DOI: 10.3390/foods12193549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/15/2023] Open
Abstract
Marigold (Tagetes spp.) flower petals are the most vital sources of carotenoids, especially lutein esters, for the production of natural lutein to use for food, feed, and pharmaceutical industries. Several marigold cultivars are cultivated globally; however, their lutein ester composition and contents have not been widely investigated. Considering this, this study aimed to identify and quantify prominent carotenoid esters from the flower petals of ten marigold cultivars by liquid chromatography (LC)-diode-array detection (DAD)-mass spectrometry (MS). In addition, tocopherols, phytosterols, and fatty acids were analyzed by gas chromatography (GC)-flame ionization detection (FID) and GC-MS. Furthermore, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+) and 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging abilities of lipophilic extracts were determined. The total carotenoid contents varied significantly (p < 0. 05, Tukey HSD) among cultivars, ranging from 25.62 (cv. Alaska)-2723.11 µg/g fresh weight (cv. Superboy Orange). Among the five major lutein-diesters, (all-E)-lutein-3-O-myristate-3'-O-palmitate and lutein dipalmitate were predominant. Among the studied cultivars, α-tocopherol was recorded, ranging from 167.91 (cv. Superboy Yellow) to 338.50 µg/g FW (cv. Taishan Orange). Among phytosterols, β-sitosterol was the most prevalent phytosterol, ranging between 127.08 (cv. Superboy Yellow) and 191.99 µg/g FW (cv. Taishan Yellow). Palmitic acid (C16:0; 33.36-47.43%) was the most dominant among the fatty acids. In this study, the highest contents of lutein were recorded from cv. Superboy Orange; however, due to the substantially higher flower petal yield, the cv. Durango Red can produce the highest lutein yield of 94.45 kg/ha. These observations suggest that cv. Durango Red and cv. Superboy Orange are the ideal candidates for lutein fortification in foods and also for commercial lutein extraction.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Ji-Ho Lee
- Department of Crop Science, Konkuk University, Seoul 143-701, Republic of Korea; (R.K.S.); (H.-Y.A.); (G.-W.P.); (J.-W.S.); (J.-H.L.); (J.-W.Y.); (M.-H.S.); (Y.-S.K.)
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Dhont JKG, Park GW, Briels WJ. Motility-induced inter-particle correlations and dynamics: a microscopic approach for active Brownian particles. Soft Matter 2021; 17:5613-5632. [PMID: 33998621 DOI: 10.1039/d1sm00426c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Amongst the theoretical approaches towards the dynamics and phase behaviour of suspensions of active Brownian particles (ABPs), no attempt has been made to specify the motility-induced inter-particle correlations as quantified by the pair-correlation function. Here, we derive expressions for the pair-correlation function for ABPs with very short-ranged direct interactions for small and large swimming velocities and low concentrations. The pair-correlation function is the solution of a differential equation that is obtained from the Fokker-Planck equation for the probability density function of the positions and orientations of the ABPs. For large swimming Peclet numbers, λ, the pair-correlation function is highly asymmetric. The pair-correlation function attains a large value, ∼λ, within a small region of spatial extent, ∼1/λ, near contact of the ABPs when the ABPs approach each other. The pair-correlation function is small within a large region of spatial extent, ∼λ1/3, when the ABPs move apart, with a contact value that is essentially zero. From the explicit expressions for the pair-correlation function, Fick's diffusion equation is generalized to include motility. It is shown that mass transport, in case of large swimming velocities, is dominated by a preferred swimming direction that is induced by concentration gradients. The expression for the pair-correlation function derived in this paper could serve as a starting point to obtain approximate results for high concentrations, which could then be employed in a first-principles analysis of the dynamics and phase behaviour of ABPs at higher concentrations.
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Affiliation(s)
- J K G Dhont
- Institute of Biological Information Processing, IBI-4, Biomacromolecular Systems and Processes, Forschungszentrum Jülich GmbH, D-52428 Jülich, Germany. and Heinrich Heine Universität, 40225 Düsseldorf, Germany
| | - G W Park
- Institute of Biological Information Processing, IBI-4, Biomacromolecular Systems and Processes, Forschungszentrum Jülich GmbH, D-52428 Jülich, Germany.
| | - W J Briels
- Institute of Biological Information Processing, IBI-4, Biomacromolecular Systems and Processes, Forschungszentrum Jülich GmbH, D-52428 Jülich, Germany. and MESA+ Institute for Nanotechnology, University of Twente, P. O. Box 217, 7500 AE Enschede, The Netherlands.
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Jo H, Kang M, Park GW, Kim BJ, Choi CY, Park HS, Shin S, Lee W, Ahn YS, Jeon JB. Effects of Cooling Rate during Quenching and Tempering Conditions on Microstructures and Mechanical Properties of Carbon Steel Flange. Materials (Basel) 2020; 13:ma13184186. [PMID: 32967133 PMCID: PMC7560453 DOI: 10.3390/ma13184186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/11/2020] [Accepted: 09/17/2020] [Indexed: 11/24/2022]
Abstract
This study investigated the mechanical properties of steel in flanges, with the goal of obtaining high strength and high toughness. Quenching was applied alone or in combination with tempering at one of nine combinations of three temperatures TTEM and durations tTEM. Cooling rates at various flange locations during quenching were first estimated using finite element method simulation, and the three locations were selected for mechanical testing in terms of cooling rate. Microstructures of specimens were observed at each condition. Tensile test and hardness test were performed at room temperature, and a Charpy impact test was performed at −46 °C. All specimens had a multiphase microstructure composed of matrix and secondary phases, which decomposed under the various tempering conditions. Decrease in cooling rate (CR) during quenching caused reduction in hardness and strength but did not affect low-temperature toughness significantly. After tempering, hardness and strength were reduced and low-temperature toughness was increased. Microstructures and mechanical properties under the various tempering conditions and CRs during quenching were discussed. This work was based on the properties directly obtained from flanges under industrial processes and is thus expected to be useful for practical applications.
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Affiliation(s)
- Haeju Jo
- Energy Materials and Components R&D Group, Korea Institute of Industrial Technology, Busan 46938, Korea; (H.J.); (M.K.); (G.-W.P.); (B.-J.K.); (S.S.); (W.L.)
- Department of Materials Science and Engineering, Pukyong National University, Busan 48513, Korea
| | - Moonseok Kang
- Energy Materials and Components R&D Group, Korea Institute of Industrial Technology, Busan 46938, Korea; (H.J.); (M.K.); (G.-W.P.); (B.-J.K.); (S.S.); (W.L.)
| | - Geon-Woo Park
- Energy Materials and Components R&D Group, Korea Institute of Industrial Technology, Busan 46938, Korea; (H.J.); (M.K.); (G.-W.P.); (B.-J.K.); (S.S.); (W.L.)
| | - Byung-Jun Kim
- Energy Materials and Components R&D Group, Korea Institute of Industrial Technology, Busan 46938, Korea; (H.J.); (M.K.); (G.-W.P.); (B.-J.K.); (S.S.); (W.L.)
| | - Chang Yong Choi
- Research Center, Felix Technology Co., Ltd., Busan 46733, Korea; (C.Y.C.); (H.S.P.)
| | - Hee Sang Park
- Research Center, Felix Technology Co., Ltd., Busan 46733, Korea; (C.Y.C.); (H.S.P.)
| | - Sunmi Shin
- Energy Materials and Components R&D Group, Korea Institute of Industrial Technology, Busan 46938, Korea; (H.J.); (M.K.); (G.-W.P.); (B.-J.K.); (S.S.); (W.L.)
| | - Wookjin Lee
- Energy Materials and Components R&D Group, Korea Institute of Industrial Technology, Busan 46938, Korea; (H.J.); (M.K.); (G.-W.P.); (B.-J.K.); (S.S.); (W.L.)
| | - Yong-Sik Ahn
- Department of Materials Science and Engineering, Pukyong National University, Busan 48513, Korea
- Correspondence: (Y.-S.A.); (J.B.J.); Tel.: +82-51-629-6361 (Y.-S.A.); +82-54-367-9407 (J.B.J.)
| | - Jong Bae Jeon
- Energy Materials and Components R&D Group, Korea Institute of Industrial Technology, Busan 46938, Korea; (H.J.); (M.K.); (G.-W.P.); (B.-J.K.); (S.S.); (W.L.)
- Correspondence: (Y.-S.A.); (J.B.J.); Tel.: +82-51-629-6361 (Y.-S.A.); +82-54-367-9407 (J.B.J.)
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Abstract
Norovirus infections are notoriously difficult to prevent and control, owing to their low infectious dose, high shedding titre, and environmental stability. The virus can spread through multiple transmission routes, of which person-to-person and foodborne are the most important. Recent advances in molecular diagnostics have helped to establish norovirus as the most common cause of sporadic gastroenteritis and the most common cause of outbreaks of acute gastroenteritis across all ages. In this article, we review the epidemiology and virology of noroviruses, and prevention and control guidelines, with a focus on the principles of disinfection and decontamination. Outbreak management relies on sound infection control principles, including hand hygiene, limiting exposure to infectious individuals, and thorough environmental decontamination. Ideally, all infection control recommendations would rely on empirical evidence, but a number of challenges, including the inability to culture noroviruses in the laboratory and the challenges of outbreak management in complex environments, has made it difficult to garner clear evidence of efficacy in certain areas of infection control. New experimental data on cultivable surrogates for human norovirus and on environmental survivability and relative resistance to commonly used disinfectants are providing new insights for further refinining disinfection practices. Finally, clinical trials are underway to evaluate the efficacy of vaccines, which may shift the current infection control principles to more targeted interventions.
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Affiliation(s)
- L Barclay
- Centers for Disease Control and Prevention, Atlanta, GA, USA
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Barclay L, Park GW, Vega E, Hall A, Parashar U, Vinjé J, Lopman B. Infection control for norovirus. Clin Microbiol Infect 2014. [PMID: 24813073 DOI: 10.1111/1469-0691.12674.infection] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Norovirus infections are notoriously difficult to prevent and control, owing to their low infectious dose, high shedding titre, and environmental stability. The virus can spread through multiple transmission routes, of which person-to-person and foodborne are the most important. Recent advances in molecular diagnostics have helped to establish norovirus as the most common cause of sporadic gastroenteritis and the most common cause of outbreaks of acute gastroenteritis across all ages. In this article, we review the epidemiology and virology of noroviruses, and prevention and control guidelines, with a focus on the principles of disinfection and decontamination. Outbreak management relies on sound infection control principles, including hand hygiene, limiting exposure to infectious individuals, and thorough environmental decontamination. Ideally, all infection control recommendations would rely on empirical evidence, but a number of challenges, including the inability to culture noroviruses in the laboratory and the challenges of outbreak management in complex environments, has made it difficult to garner clear evidence of efficacy in certain areas of infection control. New experimental data on cultivable surrogates for human norovirus and on environmental survivability and relative resistance to commonly used disinfectants are providing new insights for further refinining disinfection practices. Finally, clinical trials are underway to evaluate the efficacy of vaccines, which may shift the current infection control principles to more targeted interventions.
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Affiliation(s)
- L Barclay
- Centers for Disease Control and Prevention, Atlanta, GA, USA
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Park GW, Linden KG, Sobsey MD. Inactivation of murine norovirus, feline calicivirus and echovirus 12 as surrogates for human norovirus (NoV) and coliphage (F+) MS2 by ultraviolet light (254 nm) and the effect of cell association on UV inactivation. Lett Appl Microbiol 2011; 52:162-7. [PMID: 21214604 DOI: 10.1111/j.1472-765x.2010.02982.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS To determine inactivation profiles of three human norovirus (NoV) surrogate viruses and coliphage MS2 by ultraviolet (UV) irradiation and the protective effect of cell association on UV inactivation. METHODS AND RESULTS The inactivation rate for cell-free virus or intracellular echovirus 12 was determined by exposure to 254-nm UV light at fluence up to 100 mJ cm(-2) . The infectivity of murine norovirus (MNV), feline calicivirus (FCV) and echovirus 12 was determined by cell culture infectivity in susceptible host cell lines, and MS2 infectivity was plaque assayed on Escherichia coli host cells. The UV fluencies to achieve 4-log(10) inactivation were 25, 29, 30 and 70 (mJ cm(-2) ) for cell-free FCV, MNV, echovirus 12 and MS2, respectively. However, a UV fluence of 85 mJ cm(-2) was needed to inactivate intracellular echovirus 12 by 4 log(10) . CONCLUSIONS Murine norovirus and echoviruses 12 are more conservative surrogates than FCV to predict the UV inactivation response of human NoV. Intracellular echovirus 12 was 2·8-fold more resistant to UV irradiation than cell-free one. SIGNIFICANCE AND IMPACT OF THE STUDY Variation in UV susceptibilities among NoV surrogate viruses and a likely protective effect of cell association on virus susceptibility to UV irradiation should be considered for effective control of human NoV in water.
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Affiliation(s)
- G W Park
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA.
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Park GW, Diez-Gonzalez F. Utilization of carbonate and ammonia-based treatments to eliminate Escherichia coli O157:H7 and Salmonella Typhimurium DT104 from cattle manure. J Appl Microbiol 2003; 94:675-85. [PMID: 12631203 DOI: 10.1046/j.1365-2672.2003.01899.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The objective of this study was to investigate alkaline treatments of cattle manure to kill coliforms, Escherichia coli O157:H7 and Salmonella Typhimurium DT104 based on their inhibition by carbonate ion and ammonia. METHODS AND RESULTS Pure cultures of S. Typhimurium DT104 and E. coli O157:H7 strains were treated with sodium carbonate and ammonia to determine threshold inhibitory concentrations. Fresh cattle manure samples were inoculated with the same strains and their survival was determined after addition of sodium hydroxide, ammonium sulphate, sodium carbonate and/or urea. Control of CO and NH3 concentrations in manure by pH adjustment to 9.5 with sodium hydroxide to more than 5 and 30 mmol l-1, respectively, killed more than 106 cells g-1 in 7 days. Addition of sodium carbonate enhanced the killing effect of NaOH by increasing the CO and NH3 concentrations. Addition of 100 mmol l-1 urea, produced high levels of CO and NH3 and decreased all bacterial counts by at least 106 cells g-1 after 7 days. CONCLUSIONS Reduction of food-borne pathogens in manure can be achieved by a combination of high concentrations of CO and NH3 which are pH-dependent parameters. SIGNIFICANCE AND IMPACT OF STUDY Addition of urea could provide a simple manure treatment by combining both antimicrobial factors.
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Affiliation(s)
- G W Park
- Department of Food Science and Nutrition, University of Minnesota, St Paul, USA
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Kim KH, Gu JY, Choi HS, Park GW, Noh TW. Frequency Shifts of the Internal Phonon Modes in La0.7Ca0.3MnO3. Phys Rev Lett 1996; 77:1877-1880. [PMID: 10063194 DOI: 10.1103/physrevlett.77.1877] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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