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Foaming supramolecular surfactants for gas mobility control in naturally fractured carbonate reservoirs at high temperature,salinity,and hardness

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Petroleum Science 2022年第6期19卷 3134-3148页

作者： Enrique Soto-Castruita Raúl Hern andez-Altamirano Eduardo Buenrostro-González Erick-Emanuel Luna-Rojero sung jae ko-kim Violeta-Yasmín Mena-Cervantes Mirna Pons-Jiménez Jorge-Francisco Ramírez-Pérez David-Aaσn Nieto-Alvarez Ricardo Cerón-Camacho Jos e-Ernesto Parra Raúl Oviedo-Roa Jos e-Manuel Martínez-Magadán Rodolfo Cisneros-Dévora Luis-S.Zamudio-Rivera Instituto Mexicano del Petr oleo Eje Central Lazaro Cardenas Norte 152Col.San Bartolo AtepehuacanCiudad de Mexico07730Mexico CONACy T-Instituto Mexicano del Petroleo Eje Central Lazaro Cardenas Norte 152Col.San Bartolo AtepehuacanCiudad de Mexico07730Mexico Centro Mexicano para la Produccion mas Limpia Instituto Politecnico NacionalAvenida Acueducto s/nCol.La Laguna TicomanCiudad de Mexico07340Mexico Centro de Tecnologías para Exploracion y Produccion Camino de Terracería 800Col.San Jose NovilleroBoca delRíoVeracruz94286Mexico

Oil production and mainte nance are essential issues in naturally fractured reservoirs because they are the largest and most productive on ***,they present early water and gas channeling but could be remediated by using foaming agents to control these phenomena through blocking channeling *** Mexico these reservoirs have pressure up to 5,500 psi,high temperature up to 200℃,salinity up to400,000 ppm,and hardness up to 250,000 ppm;due to these thermodynamic conditions,there has been no available technology to form stable enough *** this work,a foaming supramolecular surfactant with the capability to chelate Ca^(2+)ions is *** a result,surfactant monomers are bridged by captured Ca^(2+)cations leading to the formation of high-molecular-weight oligomers,which significantly increment the viscosity of the solution improving the foam stability,and since at this manner the Ca2+cations are no longer available to precipitate as components of solid salts,the foaming supramolecular surfactant also performs as *** observations are explained through quantum theoretical *** foam is stable,effectively blocking the gas channels,whereas in presence of oil the foam is broken leading the oil to pass into the *** characteristic rheological properties of the foam allow its injection into the formation at a range of flow rates,foam qualities,and shear stress to achieve the flooding and the blocking of a variety of fractured carbonate formations,and the change of the wettability of the matrix,which is a desirable behavior in a huff and puff process,as reported in a previous publication about a successful pilot test of this foam.

关键词： Calcium chelation Foaming composition Supramolecular surfactant Molecular design Gas mobility control Flow assurance Improved oil recovery Conformance control

SOME LIOUVILLE-TYPE THEOREMS FOR THE STATIONARY 3D MAGNETO-MICROPOLAR FLUIDS

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Acta Mathematica Scientia 2024年第6期44卷 2296-2306页

作者： jae-Myoung kim Seungchan ko Department of Mathematics Education Andong National UniversityGyeongdong-roAndong-si36729Gyeongsangbuk-doRepublic of Korea Department of Mathematics Inha UniversityInha-roMichuhol-gu22212Incheon-siRepublic of Korea

In this paper,we prove some Liouville-type theorems for the stationary magnetomicropolar fluids under suitable conditions in three space *** first prove that the solutions are trivial under the assumption of certain growth conditions for the mean oscillations of the *** then we show similar results assuming that the solutions are contained in L^(p)(R^(3))with p∈[2,9/2).Finally,we show the same result for lower values of p∈[1,9/4)with the further assumption that the solutions vanish at infinity.

关键词： stationary magneto-micropolar equations Liouville-type theorem

Noninvasive Parameters and hepatic fibrosis scores in children with nonalcoholic fatty liver disease

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World Journal of Gastroenterology 2012年第13期18卷 1525-1530页

作者： Hye Ran Yang Hae Ryoung kim Myung Jin kim jae sung ko Jeong Kee Seo Department of Pediatrics Seoul National University College of MedicineSeoul 110-744South Korea Department of Pediatrics Seoul National University Bundang HospitalSeongnam-siGyonggi-do 463-707South Korea Department of Pathology Seoul National University Bundang HospitalSeongnam-siGyonggi-do 464-894 South Korea

AIM:To evaluate the noninvasive parameters and hepatic fibrosis scores in obese children with nonalcoholic fatty liver disease(NAFLD).METHODS:A total of 77 children diagnosed with NAFLD via liver biopsy were included and divided into 2 subgroups according to the histopathologic staging of hepatic fibrosis:mild(stage 0-1)vs significant fibrosis(stage 2-4).Clinical and laboratory parameters were evaluated in each *** aspartate aminotransferase(AST)/alanine aminotransferase(ALT)ratio,AST/platelet ratio index(APRI),PGA index,Forns index,FIB-4,NAFLD fibrosis score,and pediatric NAFLD fibrosis index(PNFI)were ***:No clinical or biochemical parameter exhibited a significant difference between patients with mild and significant *** noninvasive hepatic fibrosis scores,only APRI and FIB4 revealed a significant difference between patients with mild and significant fibrosis(APRI:0.67±0.54 vs 0.78±0.38,P=0.032 and FIB4:0.24±0.12 vs 0.31±0.21,P=0.010).The area under the receiving operating characteristic curve of FIB4 was 0.81,followed by Forns index(0.73),APRI(0.70),NAFLD fibrosis score(0.58),AST/ALT ratio(0.53),PGA score(0.45),and PNFI(0.41).CONCLUSION:APRI and FIB4 might be useful noninvasive hepatic fibrosis scores for predicting hepatic fibrosis in children with NAFLD.

关键词： Fatty liver Hepatic fibrosis Noninvasive Obesity Child

On the stacking fault forming probability and stacking fault energy in carbon-doped 17 at%Mn steels via transmission electron microscopy and atom probe tomography

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Journal of Materials Science & Technology 2022年第20期115卷 177-188页

作者： Hyo Ju Bae Kwang Kyu ko Muhammad Ishtiaq Jung Gi kim Hyokyung sung jae Bok Seol Department of Materials Engineering and Convergence Technology Center for K-metalGyeongsang National University(GNU)Jinju 52828South Korea

Assessing the stacking fault forming probability(P_(sf)) and stacking fault energy(SFE)in medium-or highMn base structural materials can anticipate and elucidate the microstructural evolution before and after ***,these two parameters have been determined from theoretical calculations and empirical ***,the estimation of SFE values in Fe–Mn–C ternary systems is a longstanding debate due to the complicated nature of carbon:that is,whether the carbon doping indeed plays an important role in the formation of stacking faults;and how the amount of carbon atoms exist at grain boundaries or at internal grains with respect to the nominal carbon doping ***,the use of atom probe tomography and transmission electron microscopy(TEM)unveils the influence of carbondoping contents on the structural properties of dual-phase Fe–17 Mn–x C(x=0–1.56 at%)steels,such as carbon segregation free energy at grain boundaries,carbon concentration in grain interior,interplanar D-spacings,and mean width of intrinsic stacking faults,which are essential for SFE *** next determined the Psfvalues by two different methods,viz.,reciprocal-space electron diffraction measurements and stacking fault width measurements in real-space TEM ***,SFEs in the Fe–17 Mn–x C systems were calculated on the basis of the generally-known SFE *** found that the high amount of carbon doping gives rise to the increased SFE from 8.6 to 13.5 m J/m^(2)with non-linear *** SFE trend varies inversely with the mean width of localized stacking faults,which pass through both other stacking faults and pre-existingε-martensite plates without much difficulty at their intersecting *** high amount of carbon doping acts twofold,through increasing the segregation free energy(due to more carbon at grain boundaries)and large lattice expansion(due to increased soluble carbon at internal grains).The experimental data obtained here strengthens the composition-

关键词： Stacking fault formation probability Stacking fault energy High-Mn steel Electron diffraction

MYB46-Mediated Transcriptional Regulation of Secondary Wall Biosynthesis

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Molecular Plant 2012年第5期5卷 961-963页

作者： jae-Heung ko Won-Chan kim Joo-Yeol kim sung-Ju Ahn Kyung-Hwan Han Department of Plant and Environmental New Resources Kyung Hee University Yongin Korea Bioenergy Center Kyung Hee University Yongin Korea Department of Horticulture and Department of Forestry Michigan State University East Lansing MI 48824-1222 USA DOE-Great Lakes Bioenergy Research Center Michigan State University East Lansing MI 48824-1222 USA Department of Bioenergy Science and Technology (WCU) Chonnam National University 333 Yongbongro Buk-gu Gwangju 500-757 Korea

Formation of secondary wall requires coordinated transcrip- tional regulation of the genes involved in the biosynthesis of major secondary wall components （e.g. cellulose, hemicellu- lose, and lignin）. Even though many aspects of plant biology have been extensively elucidated using various model spe- cies, our current understanding of secondary wall formation is limited.

关键词： Biosynthesis Regulation Wall

The predictability of T3 disease in staging MRI following prostate biopsy decreases in patients with high initial PSA and Gleason score

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Asian Journal of Andrology 2011年第3期13卷 487-493,515页

作者： Young Hwii ko Deuk jae sung sung Gu Kang Seok Ho Kang Jeong Gu Lee Je Jong kim Jun Cheon Department of Urology Korea University School of Medicine Seoul Korea Department of Radiology Korea University School of Medicine Seoul Korea

To obtain improved accuracy in predicting extracapsular extension （ECE） and seminal vesicle invasion （SVI）, we evaluated the variables affecting the predictability of staging magnetic resonance imaging （MRI, phased-array coil） and estimated their impact on accuracy between preoperative MRI staging and histological outcome. A total of 121 patients with localized or locally advanced prostate cancer who underwent robotic radical prostatectomy （RALP） were included. Following transrectal biopsy, all enrolled patients had undergone MRI for staging work-up. After RALP, only 43.8% （53/121） of the patients were matched with the MRI predicted stage. Compared to the matched group in the prediction of ECE, the unmatched group had significantly higher initial prostate-specific antigen （PSA, 12.8 ng m1-1 versus 8.1 ng m1-1, P=0.048）. In the prediction of SVI, initial PSA （8.1 ng ml- 1 versus 17.3 ng ml- 1, P=0.009） and biopsy Gleason score （6.5 versus 7.6, P=0.035） were significantly higher in the unmatched group. When applying clinical cutoffs of initial PSA of 10 and 20 ng ml-1, the accuracy of MRI in the prediction of ECE was decreased in the group with PSA over 20 ng ml- 1 （75.6, 64.5 and 37.5%, P=0.01）, and this group had significantly decreased accuracy of MRI in the prediction of SVI （91.5, 77.4 and 37.5%, P〈0.01）. Applying the clinical cutoff of a Gleason score of 7, the accuracy of MRI in the prediction of SVI was decreased in the higher G leason score group （93.9, 82.1 and 62.9%, P= 0.01）. Thus, for these patient groups, to obtain margin negativity during radical prostatectomy, operative findings, rather than post-biopsy MRI images, may provide substantial information, implying a clinical advantage in conducting MRI before prostate biopsy.

关键词： magnetic resonance imaging neoplasm staging prostatic neoplasms

Comprehensive Analysis of Caching Performance under Probabilistic Traffic Patterns for Content Centric Networking

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China Communications 2016年第3期13卷 127-136页

作者： Dabin kim Young-Bae ko sung-Hwa Lim Department of Computer Engineering Graduate School of Ajou University Department of Multimedia Namseoul University

The phenomenon of data explosion represents a severe challenge for the upcoming big data ***,the current Internet architecture is insufficient for dealing with a huge amount of traffic owing to an increase in redundant content transmission and the end-point-based communication ***-centric networking(ICN)is a paradigm for the future Internet that can be utilized to resolve the data explosion *** this paper,we focus on content-centric networking(CCN),one of the key candidate ICN *** has been studied in various network environments with the aim of relieving network and server burden,especially in name-based forwarding and in-network caching *** paper studies the effect of several caching strategies in the CCN domain from the perspective of network and server ***,we comprehensively analyze the in-network caching performance of CCN under several popular cache replication methods(i.e.,cache placement).We evaluate the performance with respect to wellknown Internet traffic patterns that follow certain probabilistic distributions,such as the Zipf/Mandelbrot–Zipf distributions,and *** the experiments,we developed an OPNET-based CCN simulator with a realistic Internet-like topology.

关键词： content-centric networking probabilistic Internet traffic patterns caching performance analysis OPNET

Early extrahepatic recurrence as a pivotal factor for survival after hepatocellular carcinoma resection:A 15-year observational study

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World Journal of Gastroenterology 2022年第36期28卷 5351-5363页

作者： jae Hyun Yoon sung Kyu Choi sung Bum Cho Hee Joon kim Yang Seok ko Chung Hwan Jun Department of Gastroenterology and Hepatology Chonnam National University Hospital and College of MedicineGwangju 61469South Korea Department of Gastroenterology and Hepatology Hwasun Chonnam National University Hospital and College of MedicineHwasun 58128South Korea Department of Surgery Chonnam National University Hospital and College of MedicineGwangju 61469South Korea Department of Surgery Hwasun Chonnam National University Hospital and College of MedicineHwasun 58128South Korea Department of Internal Medicine Mokpo Hankook HospitalMokpo 58643South Korea

BACKGROUND Surgical resection is one of the most widely used modalities for the treatment of hepatocellular carcinoma(HCC).Early extrahepatic recurrence(EHR)of HCC after surgical resection is considered to be closely associated with poor ***,data regarding risk factors and survival outcomes of early EHR after surgical resection remain *** To investigate the clinical features and risk factors of early EHR and elucidate its association with survival *** From January 2004 to December 2019,we enrolled treatment-naïve patients who were≥18 years and underwent surgical resection for HCC in two tertiary academic *** excluding patients with tumor types other than HCC and/or ineligible data,this retrospective study finally included 779 *** resection of HCC was performed according to the physicians’decisions and the EHR was diagnosed based on contrast-enhanced computed tomography or magnetic resonance imaging,and pathologic confirmation was performed in selected *** Cox regression analysis was performed to identify the variables associated with *** Early EHR within 2 years after surgery was diagnosed in 9.5%of patients during a median followup period of 4.4 *** recurrence-free survival period was 5.2 mo,and the median time to EHR was 8.8 mo in patients with early *** 52.7%of patients with early EHR,EHR occurred as the first recurrence of HCC after surgical *** multivariate analysis,serum albumin100 U/L,surgical margin involvement,venous and/or lymphatic involvement,satellite nodules,tumor necrosis detected by pathology,tumor size≥7 cm,and macrovascular invasion were determined as risk factors associated with early *** sub-categorizing the patients according to the number of risk factors,the rates of both EHR and survival showed a significant correlation with the risk of early ***,multivariate analysis revealed that early E

关键词： Early extrahepatic recurrence Hepatocellular carcinoma Prognosis Surgery Survival

Comparison of commercial silicon-based anode materials for the design of a high-energy lithium-ion battery

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Nano Research 2024年第6期17卷 5270-5277页

作者： Minhong Choi Eunhan Lee jaekyung sung Namhyung kim Minseong ko Division of Convergence Materials Engineering Pukyong National UniversityBusan 48547Republic of Korea Department of Materials Engineering and Convergence Technology Gyeongsang National University501 Jinju-daeroJinju 52828Republic of Korea Department of Materials System Engineering Pukyong National UniversityBusan 48547Republic of Korea

Silicon(Si)is considered a potential alternative anode for next-generation Li-ion batteries owing to its high theoretical capacity and ***,the commercial use of Si anodes is hindered by their large volume expansion(~300%).Numerous efforts have been made to address this *** these efforts,Si-graphite co-utilization has attracted attention as a reasonable alternative for high-energy anodes.A comparative study of representative commercial Si-based materials,such as Si nanoparticles,Si suboxides,and Si−Graphite composites(SiGC),was conducted to characterize their overall performance in high-energy lithium-ion battery(LIB)design by incorporating conventional ***-Si was found to exhibit poor electrochemical performance,with severe volume expansion during *** suboxide provided excellent cycling stability in a full-cell evaluation with stable volume variation after 50 cycles,but had a large irreversible capacity and remarkable volume expansion during the first *** displayed a good initial Coulombic efficiency and the lowest volume change in the first cycle owing to the uniformly distributed nano-Si layer on graphite;however,its long-term cycling stability was relatively *** complement each disadvantage of Si suboxide and SiGC,a new combination of these Si-based anodes was suggested and a reasonable improvement in overall battery performance was successfully achieved.

关键词： silicon-based anode high-energy comparison lithium ion battery blended electrode