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simplified Technique for Predicting Offshore Pipeline Expansion

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Journal of Marine science and Application 2018年第1期17卷 68-78页

作者： J.H.seo D.k.kim H.s.Choi s.Y.Yu k.s.park Graduate school of Engineering Mastership Pohang University of Science and TechnologyPohang 37673Republic of Korea Ocean and ship Technology Research Group Universiti Teknologi PETRONAS32610 Seri IskandarPerakMalaysia Department of Civil and Environmental Engineering Universiti Teknologi PETRONAS32610 Seri IskandarPerakMalaysia Vietnam Construction steel solution Marketing Center POSCO Vietnam HoldingsHo Chi Minh City 700000Vietnam

In this study,we propose a method for estimating the amount of expansion that occurs in subsea pipelines,which could be applied in the design of robust structures that transport oil and gas from offshore *** begin with a literature review and general discussion of existing estimation methods and terminologies with respect to subsea *** to the effects of high pressure and high temperature,the production of fluid from offshore wells is typically caused by physical deformation of subsea structures,e.g.,expansion and contraction during the transportation *** severe cases,vertical and lateral buckling occurs,which causes a significant negative impact on structural safety,and which is related to on-bottom stability,free-span,structural collapse,and many other *** addition,these factors may affect the production rate with respect to flow assurance,wax,and hydration,to name a *** this study,we developed a simple and efficient method for generating a reliable pipe expansion design in the early stage,which can lead to savings in both cost and computation *** such,in this paper,we propose an applicable diagram,which we call the standard dimensionless ratio(sDR)versus virtual anchor length(LA)diagram,that utilizes an efficient procedure for estimating subsea pipeline expansion based on applied reliable *** this user guideline,offshore pipeline structural designers can reliably determine the amount of subsea pipeline expansion and the obtained results will also be useful for the installation,design,and maintenance of the subsea pipeline.

关键词： Pipe expansion HP/HT Thermal expansion subsea pipeline

Development of hydrogen exhaust system:its dilution and acoustic performance

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Development of hydrogen exhaust system:its dilution and acou...

scalable Ir‑Doped NiFe_(2)O_(4)/TiO_(2)Heterojunction Anode for Decentralized saline Wastewater Treatment and H_(2)Production

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作者： H.C.suh J.Y.Moon k.J.kim k.s.park sejong Industrial Co. LTD kyung Hee University

＜正＞In order to exhaust remained hydrogen gas in the stack,one has to consider two aspects: safety in diluting hydrogen gas into air to control the concentration of hydrogen gas;comfort in modulating released gas to prevent harsh *** this paper,the development processes of a hydrogen exhaust system in terms of dilution efficiency and its noise reduction have been

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Nano-Micro Letters 2025年第3期17卷 1-18页

作者： sukhwa Hong Jiseon kim Jaebeom park sunmi Im Michael R.Hoffmann kangwoo Cho Division of Environmental science and Engineering Pohang University of Science and Technology(POSTECH)Pohang 790−784Korea Linde Laboratory California Institute of TechnologyPasadenaCA 91125USA Institute for Convergence Research and Education in Advanced Technology(I‑CREATE) Yonsei University International CampusIncheon 21983Republic of Korea

Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2)production can reduce the carbon footprint associated with transportation of water,waste,and energy *** study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2)overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment *** dilute(0.1 M)NaCl solutions,the NFI/TiO_(2)marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).Robust operation in near-neutral pH was *** including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic *** electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive *** scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.

关键词： Wastewater electrolysis cell Ir-doped NiFe_(2)O_(4) Reactive chlorine species Decentralized H_(2)production On-site wastewater treatment

Home Range size and Overlap of the small Nocturnal schlegel’s Japanese Gecko (Gekko japonicus), Introduced into a City park in korea

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Asian Herpetological Research 2019年第4期10卷 261-269页

作者： Il-kook park Dae-In kIM Jonathan JFONG Daesik park Department of Biology Kangwon National UniversityChuncheonKangwon 24341South Korea science Unit Lingnan UniversityTuen MunNew TerritoriesHong KongChina Division of science Education Kangwon National UniversityChuncheonKangwon 24341South Korea

studying the home range of an organism is important in understanding its ecology. Due to being cryptic, few studies have been conducted on the home range studies of small, nocturnal geckos. We conducted radio-tracking surveys for 23 individuals to estimate the home range size and home range overlap of the schlegel’s Japanese gecko(Gekko japonicus) previously introduced into a suburban city park. Individuals were commonly found in artificial structures(buildings and accessory structures) and on nearby natural trees. Daily moved distance was positively correlated with home range size. Minimum convex polygon(MCP) home range was 97.8 m^2 for females and 99.5 m^2 for males, on average. Gekko japonicus moved farther daily distances and used wider MCP and kernel 95 home ranges in breeding season compared to non-breeding season, while the size of kernel 50 home range did not differ between seasons. Both daily moved distance and home range size were not significantly different between sexes. In the breeding season, MCP and kernel 50 home ranges of each gecko overlapped with 32.4% and 13.8% of remaining geckos, respectively. Our results not only show that 1) G. japonicus uses both artificial structures and adjacent natural trees as microhabitat, but also suggest that 2) G. japonicus is non-territorial, but has a core habitat that is shared with few other individuals, and 3) the reproductive system of G. japonicus is polygamous.

关键词： radio telemetry invasive species territory lizard korea

Effect of synthesis Method on Photoluminescence Properties of Na_2sr_2Al_2PO_4Cl_9:Ce^(3+) Nanophosphor

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Nano-Micro Letters 2012年第2期4卷 78-82页

作者： k.N.shinde s.J.Dhoble k.park N. s. science and Arts College Department of Physics RTM Nagpur university Faculty of Nanotechnology and Advanced Materials Engineering Sejong University

We have synthesized a series of single-composition emission Na_2sr_2Al_2PO_4Cl_9:Ce^(3+) phosphor by traditional solid state reactions and novel combustion method. Formation of compound was confirmed by X-ray diffraction analysis. The photoluminescence(PL) emission spectra were observed at 376 nm when excited around 322 nm for the various concentrations in both cases. The PL emission spectra of phosphors showed strong Ce^(3+)emission due to the 5d → 4f transition of Ce^(3+)ions. The Ce^(3+)emission intensity in Na_2sr_2Al_2PO_4Cl_9:Ce^(3+) prepared by combustion was higher than that of solid state reactions.

关键词： Nanophosphor Luminescence Halophosphate

Enhanced thermoelectric performance of spark plasma sintered p-type Ca_(3-x)Y_(x)Co_(4)O_(9+δ)systems

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Journal of Materials science & Technology 2020年第20期52卷 212-222页

作者： J.s.Cha D.H.kim H.Y.Hong k.park Faculty of Nanotechnology and Advanced Materials Engineering Sejong UniversitySeoul05006Republic of Korea

Highly textured dense Ca3-xYxCo4 O9+δ(0≤x≤0.3)samples were fabricated by combining sol-gel process with spark plasma sintering(sPs).Y^3+substitution for Ca^2+simultaneously increased the seebeck coefficient and reduced the thermal *** latter was attributed to the increase in lattice anharmonicity,structural distortion,and grain boundary area,which enhanced the phonon ***2.7Y0.3Co4 O9+δshowed the largest dimensionless figure-of-merit(ZT=0.194)at 1073 k because it had the largest seebeck coefficient and the lowest thermal *** ZT value was 55%larger than that of undoped Ca3 Co4 O9(0.125 at 1073 k).Therefore,Y^3+substitution,sol-gel powder synthesis,and sPs are highly effective for enhancing the thermoelectric prope rties of Ca_(3)Co_(4)O_(9).

关键词： Electrical conductivity Ca_(3)Co_(4)O_(9) Thermoelectric properties seebeck coefficient Thermal conductivity spark plasma sintering

sensorless control for hysteresis compensation of AFM scanner by modified Rayleigh model

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Journal of Central south University 2010年第6期17卷 1243-1246页

作者： park J k MOON W k Department of Mechanical Engineering Changwon National UniversityChangwon 641-773Korea Department of Mechanical Engineering Pohang Unive rsity of Science and TechnologyPohang 790-784Korea

A novel modified Rayleigh model was developed for compensating hysteresis problem of an atomic force microscope(AFM) *** high driving fields,piezoelectric actuators that integrated a scanner have severe hysteresis,which can cause serious displacement *** hysteresis is from various origins including movement of defects,grain boundary effects,and displacement of ***,because its characteristic is stochastic,it is almost impossible to predict the piezoelectric hysteresis ***,it was predicted phenomenologically,which means that the relationship between inputs and outputs is *** typical phenomenological approach is the Rayleigh ***,the model has the discrepancy with experiment result as the fields *** overcome the demerit of the Rayleigh model,a modified Rayleigh model was *** the modified Rayleigh model,each coefficient should be defined differently according to the field direction due to the increase of the asymmetry in the high *** applying an inverse form of this modified Rayleigh model to an AFM scanner,it is proved that hysteresis can be compensated to a position error of less than 5%.This model has the merits of reducing complicated fitting procedures and saving computation time compared with the Preisach model.

关键词： piezoelectric stack actuator hysteresis compensation Rayleigh model atomic force microscopy

Liquid-liquid extraction and separation of total rare earth(RE) metals from polymetallic manganese nodule leaching solution

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Journal of Rare Earths 2015年第2期33卷 207-213页

作者： P.k.Parhi k.H.park C.W.Nam J.T.park Mineral Resources Research Division Korea Institute of Geoscience & Mineral Resources (KIGAM)Daejeon 305-350 Republic of Korea school of Applied science and Center of Industrial Technology KIIT UniversityBhubaneswar 751024 Odisha India

The study on the solvent extraction for quantitative and selective separation of total rare earth metals from the polymetallic nodule leach liquor was investigated. The typical leach liquor bearing 0. 094 g/L total rare earth, 0. 23 g/L Mn, 0.697 g/L Cu, 0.2 g/L Fe, 0.01 g/L Co and 0.735 g/L Ni was subjected to the removal iron content by precipitation method using Ca（OH）2 at pH 3.95, prior to solvent extraction of rare earth metals. Three different organo-phosphoric acid reagents（D2EHPA, PC88 A, Cyanex 272） were used to ascertain their performances and selectivity towards the loading of rare earth metals in presence of other base metals. Based on the results of eq. pH effect, the performances of above three extractants followed the order as： D2EHPA〉PC88A〉Cyanex 272. To ensure the absence of extraction of base metals（Cu, Co, Ni）, the eq. pH of the solution was optimized at the level of 2.21, though higher rare earth metal extraction efficiency was observed at higher eq. pH with either of the extractants. The complete process flow diagram for substantial recovery of total rare earth was developed using D2 EHPA. Extraction isotherm plot was constructed at A：O=12：1, 3-stages and pHe=2.21, using 0.8 mol/L D2 EHPA and the predicted condition of this study was further confirmed by 6-Cycles Counter Current simulation（CCs） study. The stripping of total rare earth from loaded organic phase（LO） was conducted using HCl solution. Mc-Cabe Thiele diagram study carried out at A：O=1：5 using 4 mol/L HCl showed that three theoretical stages were needed for quantitative stripping of total rare earth. The subsequent stripped solution resulted thus led to contain total rare earth of 5.6 g/L indicating a very high enrichment of total metals by solvent extraction（sX） process.

关键词： total rare earth (RE) metals sX D2EHPA HCl deep sea nodule

Hard Winter Wheat and Flour Properties in Relation to Breadmaking Quality of straight-dough Bread:Flour Particle size and Bread Crumb Grain

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食品科学 2006年第11期27卷 164-170页

作者： s H park O k Chung P A seib UsDA-ARs Grain Marketing and Production Research Center Manhattan KS 66502 USA Department of Grain science and Industry Kansas State University Manhattan KS 66506 USA

samples of 12 hard winter wheats and their flours that produced breads varying in crumb grain scores were studied for 38 quality parameters including: wheat physical and chemical characteristics; flour ash and protein contents,starch damage,swelling power,pasting characteristics,and flour particle size distribution; dough properties determined by a mixograph; and breadmaking properties for pup loaves (100g flour). Only two parameters,the protein content of wheat and the granulation of flour,showed significant correlations with bread crumb grain scores. Protein content of wheat ranging 12.9%～14.5% determined by an NIR method showed a weak inverse relationship (r =-0.61,pscore. Flour particle size distribution measured by both Alpine Air Jet sieve and NIR methods revealed that the weight wt % of particles less than 38μm in size and representing 9.6%～19.3% of the flour weights was correlated positively (r =0 .78,pscore,whereas wt % of flour particles larger than 125μm had an inverse relationship (r =-0.60,pscore.

关键词： Hard Winter Wheat and Flour Properties in Relation to Breadmaking Quality of straight-dough Bread