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Iso-propyl caprylate and iso-propyl linolenate synthetic fluids as novel alternatives in deep-water drilling operations:Critical fluid properties and aerobic biodegradability assessments

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Petroleum 2024年第2期10卷 254-264页

作者： Adewale johnson Folayan Adewale Dosunmu Aleruchi Boniface Oriji Department of Petroleum and Gas Engineering University of Port HarcourtNigeria Professor of Petroleum and Gas Engineering University of Port HarcourtNigeria

Present drilling fluids for deep water wells have severe degenerative effect on the environment with high operational and disposal ***,making them less desirable in recent *** synthetic drilling fluid provides a novel environmentally friendly alternative but conventional ester-based drilling fluids exhibit high viscosities in deep-water wells causing excessive equivalent circulating density(ECD)and increased risk of lost circulation owing to narrow mud density *** study experimentally investigates the critical fluid properties and aerobic biodegradability potentials of two newly developed deep-water synthetic ester drilling fluids namely:iso-propyl caprylate(COIPE)and iso-propyl linolenate(LOIPE)synthetic fluids and their comparison with synthetic-paraffin(SP-SBF)and isomerized-olefin(IOSBF)synthetic hydrocarbon *** esters of iso-propyl caprylate and iso-propyl linolenate were produced from the isolation of ester mixtures that were obtained from the homogeneous catalytic transesterification of coconut and linseed plant oil biomass *** COIPE was isolated from the coconut oil iso-propyl ester mixture by low-pressure fractional distillation *** fractional distillation and crystallization were used to isolate the LOIPE ester from the linseed oil iso-propyl ester ***,the aerobic biodegradation investigation was conducted by a modified oxygen consumption respirometry *** GC-MS analysis of the COIPE and LOIPE showed that the former contains essentially of lower saturated carbon compounds(C8).Whereas the latter contains higher molecular weight and unsaturated carbon compounds(C18+).The COIPE and LOIPE kinematic viscosity values are in good agreement with that of the reference synthetic hydrocarbon fluid samples(SP-SBF and IO-SBF).Although,the COIPE synthetic ester has lower viscosity value owing to the presence of shorter chain and saturated carbon atoms(C8 esters).Similarly,the linolenic oil iso

关键词： Aerobic biodegradation Critical fluid properties Deep-water wells Esters'isolation:isomerized-olefin(IO-SBF) Iso-propyl caprylate(COIPE) Iso-propyl linolenate(LOIPE) Respirometry technique Synthetic-paraffin(SP-SBF)

Osteopontin: a leading candidate adhesion molecule for implantation in pigs and sheep

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Journal of Animal Science and Biotechnology 2015年第2期6卷 177-190页

作者： Greg A johnson Robert C Burghardt Fuller W Bazer Department of Veterinary Integrative Biosciences Texas A&M UniversityCollege Station Department of Animal Science Texas A&M UniversityCollege Station

Osteopontin （OPN; also known as Secreted Phosphoprotein 1, SPP1） is a secreted extra-cellular matrix （ECM） protein that binds to a variety of cell surface integrins to stimulate cell-cell and cell-ECM adhesion and communication. It is generally accepted that OPN interacts with apically expressed integrin receptors on the uterine luminal epithelium （LE） and conceptus trophectoderm to attach the conceptus to the uterus for implantation. Research conducted with pigs and sheep has significantly advanced understanding of the role（s） of OPN during implantation through exploitation of the prolonged peri-implantation period of pregnancy when elongating conceptuses are free within the uterine lumen requiring extensive paracrine signaling between conceptus and endometrium. This is followed by a protracted and incremental attachment cascade of trophectoderm to uterine LE during implantation, and development of a true epitheliochorial or synepitheliochorial placenta exhibited by pigs and sheep, respectively. In pigs, implanting conceptuses secrete estrogens which induce the synthesis and secretion of OPN in adjacent uterine LE. OPN then binds to αvβ6 integrin receptors on trophectoderm, and the αvβ3 integrin receptors on uterine LE to bridge conceptus attachment to uterine LE for implantation. In sheep, implanting conceptuses secrete interferon tau that prolongs the lifespan of CL. Progesterone released by CL then induces OPN synthesis and secretion from the endometrial GE into the uterine lumen where OPN binds integrins expressed on trophectoderm （αvβ3） and uterine LE （identity of specific integrins unknown） to adhere the conceptus to the uterus for implantation. OPN binding to the αvβ3 integrin receptor on ovine trophectoderm cells induces in vitro focal adhesion assembly, a prerequisite for adhesion and migration of trophectoderm, through activation of： 1） P70S6K via crosstalk between FRAP1/MTOR and MAPK pathways; 2） MTOR, PI3K, MAPK3/MAPK1 （Erk1/2） and MAPK14 （p38） signalin

关键词： Implantation Integrins Psteoponti Pigs Sheep

Evolutionary diversity as a catalyst for biological discovery

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Integrative Zoology 2018年第6期13卷 616-633页

作者： Zachary V.johnson Larry J.YOUNG School of Biological Sciences Georgia Institute of TechnologyAtlantaGeorgiaUSA Center for Translational Social Neuroscience Silvio O.Conte Center for Oxytocin and Social CognitionDepartment of Psychiatry and Behavioral SciencesYerkes National Primate Research CenterEmory UniversityAtlantaGeorgiaUSA

The tremendous diversity of animal behaviors has inspired generations of scientists from an array of biological *** complement investigations of ecological and evolutionary factors contributing to behavioral evolution,modern sequencing,gene editing,computational and neuroscience tools now provide a means to discover the proximate mechanisms upon which natural selection acts to generate behavioral *** behaviors are motivated behaviors that can differ tremendously between closely related species,suggesting phylogenetic plasticity in their underlying biological *** addition,convergent evolution has repeatedly given rise to similar forms of social behavior and mating systems in distantly related *** behavioral divergence and convergence provides an entry point for understanding the neurogenetic mechanisms contributing to behavioral *** argue that the greatest strides in discovering mechanisms contributing to social behavioral diversity will be achieved through integration of interdisciplinary comparative approaches with modern tools in diverse species *** review recent advances and future potential for discovering mechanisms underlying social behavioral variation;highlighting patterns of social behavioral evolution,oxytocin and vasopressin neuropeptide systems,genetic/transcriptional“toolkits,”modern experimental tools,and alternative species systems,with particular emphasis on Microtine rodents and Lake Malawi cichlid fishes.

关键词： cichlids oxytocin and vasopressin social behavior toolkits voles

Characterisation, Luminescence and Antibacterial Properties of Stable AgNPs Synthesised from AgCl by Precipitation Method

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Journal of Materials Science & Technology 2015年第11期31卷 1125-1132页

作者： Arockiasamy Ajaypraveenkumar johnson Henry Kannusamy Mohanraj Ganesan Sivakumar Sankaran Umamaheswari Department of Physics Manonmaniam Sundaranar University Centralised Instrumentation and Service Laboratory Department of Physics Annamalai University Department of Biotechnology Manonmaniam Sundaranar University

Silver nanoparticles （AgNPs） were synthesised using equimolar concentrations of redtlcing agent vitamin C and AgCl precursor by simple precipitation method. The synthesised AgNPs were characterised by X-ray diffraction （XRD）, UV-Visible, photoluminescence and field emission scanning electron microscopy （FESEM） analysis. The formation of AgNPs was confirmed by the typical surface plasmon resonance band at 426 nm. The presence of elemental silver and pure crystalline face centre cubic （fcc） structure was confirmed by energy dispersive X-ray analysis and XRD analysis, respectively. The FESEM images showed the formation of spherical AgNPs for lower concentrations （0.1 and 0.3 mol/L） while spike and flower shaped particles were formed for higher concentration. Photoluminescence characteristic band was observed with no shift at 390 nm indicating the stable nature of AgNPs. The antibacterial property of the AgNPs was tested against gram negative bacteria Pseudomonas aeruginosa by using Cissus quadrangular as a control and the result showed that vitamin C reduced AgNPs have good antibacterial activity.

关键词： Silver nanoparticles Precipitation Rietveld refinement Photoluminescence spectroscopy Optical properties

Volcano video data characterized and classified using computer vision and machine learning algorithms

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Geoscience Frontiers 2020年第5期11卷 1789-1803页

作者： Alex J.C.Witsil Jeffrey B.johnson Department of Geosciences Boise State UniversityBoiseIDUSA

Video cameras are common at volcano observatories,but their utility is often limited during periods of crisis due to the large data volume from continuous acquisition and time requirements for manual *** cameras to serve as effective monitoring tools,video frames must be synthesized into relevant time series signals and further analyzed to classify and characterize observable *** this study,we use computer vision and machine learning algorithms to identify periods of volcanic activity and quantify plume rise velocities from video *** were collected at Villarrica Volcano,Chile from two visible band cameras located^17 km from the vent that recorded at 0.1 and 30 frames per second between February and April *** these two months,Villarrica exhibited a diverse range of eruptive activity,including a paroxysmal eruption on 3 *** to and after the eruption,activity included nighttime incandescence,dark and light emissions,inactivity,and periods of cloud *** quantify the color and spatial extent of plume emissions using a blob detection algorithm,whose outputs are fed into a trained artificial neural network that categorizes the observable activity into five *** shifts from primarily nighttime incandescence to ash emissions following the 3 March paroxysm,which likely relates to the reemergence of the buried lava *** periods exhibiting plume emissions are further analyzed using a row and column projection algorithm that identifies plume onsets and calculates apparent plume horizontal and vertical rise *** onsets are episodic,occurring with an average period of^50 s and suggests a puffing style of degassing,which is commonly observed at ***,the lack of clear acoustic transients in the accompanying infrasound record suggests puffing may be controlled by atmospheric effects rather than a degassing regime at the *** presented here offer a generalized toolset for volcano monito

关键词： Volcano monitoring Plume exit velocity Volcano webcam Image processing Machine learning Villarrica

Correlates of subjectively and objectively measured physical activity in young adolescents

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Journal of Sport and Health Science 2015年第3期4卷 222-227页

作者： Kelly Kavanaugh Justin B. Moore Leisha johnson Hibbett andrew T. Kaczynski Office of Practice and Community Engagement University of South Carolina Columbia SC 29208 USA Department of Health Promotion Education and Behavior University of South Carolina Columbia SC 29208 USA Coastal Community Action Newport NC 28570 USA

Background： Many studies examining individual-level correlates in youth utilize self-report rather than objective measures of physical activity （PA）. This utilization of self-report may result in associations that are not present when examining objectively measured PA. The present study investigates the relationship between hypothesized correlates of PA with objectively and subjectively measured PA. Methods： Participating children （n 232, 101 males, mean age - 12.3 years） provided a minimum of four monitored days of PA （via accelerometer） and completed a survey assessing moderate-to-vigorous physical activity （MVPA）, sport competence, appearance, enjoyment, and self-efficacy. Height and weight were measured and body mass index （BMI） was calculated. Results： Hierarchical regression models controlling for sex, race, and BMI Z-score showed that only sex and BMI Z-score were significant correlates of objective MVPA while only sex was a significant correlate of objective total PA. However, in a separate model examining the relationship with subjective MVPA, enjoyment of PA and self-efficacy for PA were the only significant correlates of self-reported PA. Conclusion： Measuring MVPA via self-report versus accelerometry produces considerably different results in a sample of young adolescents. Future studies should use caution when selecting outcome measures if the intent is to identify modifiable correlates of MVPA in youth.

关键词： Accelerometry Enjoyment Self-efficacy Youth

Controlling the orientation of hole transport molecules in bottlebrush polymers for enhanced OLED performance

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Aggregate 2022年第5期3卷 1-2页

作者： Ho Fung Cheng Jeremiah A.johnson Department of Chemistry Massachusetts Institute of TechnologyCambridgeMassachusettsUSA

Organic light-emitting diodes(OLEDs)have been widely applied in lighting and display *** performance of OLED devices depends on not only material composition but also the packing and morphology of each functional *** effort has been devoted to control the alignment of charge transport functionalities to achieve a higher OLED efficiency by lowering the hole-injection barrier.

关键词： bottlebrush hole transport OLED polymer

Mutual Authentication Protocols for RFID Systems

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International Journal of Automation and computing 2008年第4期5卷 348-365页

作者： Ashrar A.Omer johnson P.Thomas Department of Computer Science Oklahoma State University

With the availability of low-cost radio frequency identification (RFID) tags,security becomes an increasing concern. However,such tags do not permit complex cryptographic functions due to their computational,communications,and storage limitations. In this paper,we investigate the security issues and requirements of RFID systems,and propose ultra-light weight and light weight protocols for low-cost RFID *** proposed protocols has been applied to a supply chain management system.

关键词： Security mutual authentication supply chain management RFID Systems.

Investigation of ductile iron casting process parameters using Taguchi approach and response surface methodology

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China Foundry 2016年第5期13卷 352-360页

作者： A. johnson Santhosh A. R. Lakshmanan Dept of Mechanieal Engineering PPG Institute of Technology Coimbatore India Dept of Mechanical Engineering PSG College of Technology Coimbatore India

To find the optimized levels of various casting parameters in the ductile iron casting, various casting defects and the rejection rate were observed from a medium scale foundry. The controlled values of different casting parameters such as pouring temperature, inoculation, carbon equivalent, moisture content, green compression strength, permeability and mould hardness were selected. Three different melts of metal with 0.4wt.%, 0.6wt.%, and 0.8wt.% inoculation （Fe-Si-Mg alloy and post inoculant） were produced using a 1-ton capacity coreless medium frequency induction furnace. L-27 orthogonal array with 3-level settings were chosen for the analysis. Responses for each run were observed. The signal-to-noise （S/N） ratio for each run was calculated using the Taguchi approach, and the optimized levels of different casting parameters were identified based on the SIN ratio. The analysis of variance for the casting acceptance percentage concludes that inoculation is the most significant factor affecting the castings＇ quality with a contribution percentage of 44%; an increase in inoculation results in a significant improvement in acceptance percentage of ductile iron castings. The experiment results showed that with the optimized parameters, the rejection rate was reduced from 16.98% to 6.07%.

关键词： optimized levels casting parameters S/N ratio Taguchi approach ANOVA ‘F’-Test