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Transformer oil reclamation by combining several strategies enhanced by the use of four adsorbents

IET GENERATION TRANSMISSION & DISTRIBUTION 2017年第11期11卷 2912-2920页

作者： Safiddine, L. Zafour, Amel Hadj-Ziane Fofana, Issouf Skender, Abdelhak Guerbas, Fettouma Boucherit, Ahmed Univ Saad Dahlab Blida 1 Lab Genie Chim Route SoumaaBP 270-09000 Blida Algeria Spa SKMK Chef Div Sonelgaz Blida Algeria Univ Quebec Chicoutimi ViAHT Chicoutimi PQ Canada USTHB Univ LSEI Lab BP 32 El Alia 16111 Bab Ezzouar Alger Algeria

From an environmental perspective, petroleum-based aged oils removed from power transformers are source of several pollutants and therefore cannot be disposed of without due care. The degradation of oil in in-service transformers is due to various factors concurrent with the operation of the units over several years. The present study proposes a new strategy to rejuvenate used mineral oils by combining centrifugation, dehydration and sorption with four different adsorbents: activated carbon (AcH), silica gel (SG), magnesium oxide (MO) and activated bentonite (AB). The process of regeneration proposed in this study resulted in a level of restoration that saw the used oil take on the characteristics of new oil (colour, dissipation factor, resistivity, permittivity, acid number). The results also showed that the optimum form of the re-refined base oil can be attributed to a 10% (w/w) quaternary mixture of the adsorbents, itself comprised of 1% AcH, 6% SG, 1% MO and 2% AB. The anticipated benefits are reduced risk of dielectric breakdown blamed for over 75% of extra high-voltage (EHV) power transformer failures and extended transformer life expectancy by retarding the solid insulation aging processes.

关键词： activated carbon power transformer insulation transformer oil gels manganese compounds dissociation sorption minerals transformer oil reclamation adsorbents petroleum-based aged oils pollutants in-service transformers mineral oils centrifugation dehydration sorption activated carbon silica gel magnesium oxide activated bentonite regeneration process dielectric breakdown high-voltage power transformer failures extended transformer life expectancy solid insulation aging processes c MnO

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Acoustofluidic Rotational Manipulation of cells and Organisms Using Oscillating Solid Structures

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SMALL 2016年第37期12卷 5120-5125页

作者： Ozcelik, Adem Nama, Nitesh Huang, Po-Hsun Kaynak, Murat McReynolds, Melanie R. Hanna-Rose, Wendy Huang, Tony Jun Duke Univ Dept Mech Engn & Mat Sci Durham NC 27708 USA Penn State Univ Dept Engn Sci & Mech 227 Hammond Bldg University Pk PA 16802 USA Penn State Univ Dept Biochem & Mol Biol University Pk PA 16802 USA

A polydimethylsiloxane microchannel featuring sidewall sharp-edge structures and bare channels, and a piezoelement transducer is attached to a thin glass slide. When an external acoustic field is applied to the microchannel, the oscillation of the sharp-edge structures and the thin glass slide generate acoustic streaming flows which in turn rotate single cells and c. elegans in-plane and out-of-plane.

关键词： acoustofluidics c elegans microfluidics rotational manipulations

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The effects of co-utilizing green manure and rice straw on soil aggregates and soil carbon stability in a paddy soil in southern china

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Journal of Integrative Agriculture 2023年第5期22卷 1529-1545页

作者： ZHANG Zi-han NIE Jun LIANG Hai WEI cui-lan WANG Yun LIAO Yu-lin LU Yan-hong ZHOU Guo-peng GAO Song-juan cAO Wei-dong College of Resources and Environmental Sciences Nanjing Agricultural UniversityNanjing 210095P.R.China Soil and Fertilizer Institute of Hunan Province Hunan Academy of Agricultural SciencesChangsha 410125P.R.China College of Environment and Ecology Jiangsu Open UniversityNanjing 210036P.R.China Key Laboratory of Plant Nutrition and Fertilizer Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China

The co-utilization of green manure (GM) and rice straw (RS) in paddy fields has been widely applied as an effective practice in southern ***,its effects on soil aggregate and soil organic carbon (SOc) stability remain *** the present study,the effect of GM,RS,and co-utilization of GM and RS on particle size distribution of soil aggregates and SOc density fractions were measured in a field *** experiment included six treatments,i.e.,winter fallow (WF) without RS return (ctrl),WF with 50%RS return (1/2RS),WF with 100%RS return (RS),GM without RS return (GM),GM with 50%RS return (GM1/2RS) and GM with 100%RS return (GMRS).The results showed that the proportion of small macro-aggregates (0.25–2 mm) and the mean weight diameter (MWD) of aggregates in the GMRS treatment was greater (by 18.9 and 3.41%,respectively) than in the RS treatment,while the proportion of silt+clay particles (<0.053 mm) was lower (by 14.4%).The concentration of SOc in microaggregates (0.053–0.25 mm)and silt+clay particles was higher in the GMRS treatment than in GM and RS treatments *** concentration and proportion of free light organic carbon (fLOc) in aggregates of various particle sizes and bulk soil was greater in the GMRS treatment than the RS treatment,whereas the concentration and proportion of mineral-associated organic carbon in small macroaggregates,microaggregates,and bulk was lower in the GMRS treatment than in the RS *** proportion of intra-aggregate particulate organic carbon (iPOc) was greater in the GMRS treatment than in GM *** GMRS treatment had strong positive effects on iPOc in small macroaggregates,suggesting that SOc was transferred from fLOc to *** conclusion,co-utilizing green manure and rice straw cultivated the SOc pool by increasing the concentration of fLOc and improved soil carbon stability by promoting the sequestration of organic carbon in iPOc as a form of physical protection.

关键词： soil aggregation milk vetch rice straw Soc density fractions c stability paddy soil

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Direct observation of the Bi,Pb(2223) phase formation inside Ag-sheathed tapes and quantitative secondary phase analysis by means of in situ high-temperature neutron diffraction

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PHYSIcA c 1999年第3-4期315卷 185-197页

作者： Giannini, E Bellingeri, E Passerini, R Flükiger, R Univ Geneva DPMC CH-1211 Geneva Switzerland

Reactions occurring in Ag-sheathed Bi,Pb(2223) monofilamentary tapes have been studied in situ using high-temperature neutron diffraction. A neutron compatible furnace enabled us to anneal tapes under the same processing conditions as those used for standard high-performance monofilamentary tapes. Scattering data were collected all the time during the thermal treatment and different cooling procedures were compared. The data were analyzed using a full-pattern profile refinement: seven phases were simultaneously refined so that it was possible to carry out a full quantitative analysis of secondary phases during the reaction thermal treatment. The steady conversion of Bi,Pb(2212) into Bi,Pb(2223) was quantified, and the structural transformations occurring in the Bi(2212) prior to its conversion in to Bi(2223) were carefully analyzed. The role of different Pb-rich phases, such as ca2PbO4 and Pb-3(Sr,Bi)(3)ca2cuOy, at this stage of the reaction is discussed. Formation of Srgca6cu24O41 and Bi(2201) was observed at high temperature and quantitatively analyzed. During slow cooling, we observed a re-growth of Bi(2212) which did not correspond to any decomposition of Bi,Pb(2223). At the same time, the decomposition of Sr8ca6cu24O41 and Bi(2201) was observed and this phenomenon was likely to be related to the increase of the Bi(2212) amount on cooling. Thanks to the neutron diffraction technique, which allows a direct measurement of the absolute amount of crystalline matter inside the sample, it was possible to estimate for the first time the amount of the amorphous matter present. It was found to vary with time and temperature: its non-monotonic evaluation provides a proof of melting and recrystallization occurring over a wide time window at the early stages of the reaction. (c) 1999 Elsevier Science B.V. All rights reserved.

关键词： 74.72.H-Bi-based high- T c superconductors 61.12-Neutron diffraction

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Effect of pyrocarbon interphase texture and thickness on tensile damage and fracture in T-700™ carbon fiber-reinforced silicon carbide minicomposites

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JOURNAL OF THE AMERIcAN cERAMIc SOcIETY 2022年第3期105卷 2171-2181页

作者： Duan, Haozhi Zhang, Zhongwei Li, Longbiao Li, Weijie Beijing Inst Technol Inst Adv Struct Technol Beijing 100081 Peoples R China Nanjing Univ Aeronaut & Astronaut Coll Civil Aviat 29 Jiangjun Ave Nanjing 211106 Peoples R China Beijing Jiaotong Univ Inst Engn Mech Beijing 100044 Peoples R China

In this paper, T-700 (TM) carbon fiber-reinforced silicon carbide (c/Sic) minicomposites with pyrocarbon (Pyc) interphase with different textural microstructure and thickness were fabricated using the chemical vapor infiltration method. The interface properties (i.e., textural microstructure, thickness, hardness, and modulus) were obtained through multiple testing methods (i.e., Raman spectroscopy, X-ray diffraction, scanning electron microscopy, and nanoindentation tests). Relationships between the deposition temperature and residence time with the texture type (i.e., low, medium, and high texture) were established. Uniaxial tensile experiments were conducted for c/Sic minicomposites with different Pyc interphases to characterize the composite's internal damage evolution and fracture. Relationships between the composite's tensile nonlinear damage evolution, fracture strength and strain, Pyc interphase texture, and thickness were established. The composite's tensile strength and fracture strain were the highest for the c/Sic minicomposite with medium-high texture Pyc interphase. For the c/Sic minicomposite with the same texture interphase, the composite's tensile strength and fracture strain were affected by the coating thickness. The higher the thickness of the coating, the lower the composite's tensile strength and fracture strain.

关键词： c Sic minicomposite matrix cracking mechanical properties Pyc interphase texture

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Peptic hydrolysis of bovine beta-lactoglobulin under microwave treatment reduces its allergenicity in an ex vivo murine allergy model

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INTERNATIONAL JOURNAL OF FOOD ScIENcE AND TEcHNOLOGY 2015年第2期50卷 356-364页

作者： El Mecherfi, Kamel-Eddine Rouaud, Olivier curet, Sebastien Negaoui, Hanane chobert, Jean-Marc Kheroua, Omar Saidi, Djamel Haertle, Thomas Univ Oran Lab Physiol Nutr & Securite Alimentaire Equipe Allergie Oran 31000 Algeria INRA UR Biopolymeres Interact Assemblages 1268 Equipe Fonct & Interact Prot F-44316 Nantes 3 France CNRS UMR 6144 GEPEA ONIRIS F-44322 Nantes France

In this study, the in vivo allergenicity of bovine beta-lactoglobulin (BLG) in peptic whey protein hydrolysates generated during microwave and conventional heating treatments was assessed. The allergenicity of the hydrolysates was explored by studying the reaction of the murine jejunum from previously immunised Balb/c mice to treated BLG in an Ussing chamber. Intestinal anaphylactic reactions after stimulation of the gut-associated immune system are a good indicator of potential in vivo allergenicity of whey hydrolysates. Fifty-two per cent of BLG was hydrolysed by pepsin after only 3min of microwave irradiation at 200 watts (W), yet it remained intact under conventional heating. Far- and near-UV circular dichroism spectra indicated significant changes in BLG secondary and tertiary structures with microwave irradiation at 200W. Pepsin whey protein hydrolysates obtained with microwave irradiation at 200W for 3min did not stimulate secretion of chloride in the Ussing chamber, as shown by the intensity of the short current values recorded (27.86Acm(-2)), compared to the conventional pepsin hydrolysates (68.21Acm(-2)). This demonstrates the low allergenicity of whey protein hydrolysates generated in this manner. These results confirm that microwave treatment combined with peptic hydrolysis could be applied to produce low allergenicity milk peptides.

关键词： Allergy Balb c bovine beta-lactoglobulin microwaves milk proteins pepsin hydrolysis

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Theoretic optimisation of microfluidic and magnetic self-assembly of carbon nanotubes

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MIcRO & NANO LETTERS 2014年第8期9卷 523-528页

作者： Shim, Joon S. Kwangwoon Univ Dept Convergence Elect Engn Seoul South Korea

In this reported work, a magnetic and fluidic analysis has been performed to theoretically analyse the self-assembly mechanism of carbon nanotubes (cNTs) and to characterise the assembling environments for the high-density integration of individual cNTs. In previous work by the present author, the residual iron (Fe) catalyst at one end of a cNT was magnetically captured and the captured cNT was aligned along the flow direction by fluid drag force, leading to precise individual integration of cNTs between electrodes. To advance the previous work and technique, theoretic characterisations were executed to optimise the assembling conditions which increased the number of attached cNTs with a high density of integration. For calculating the fluidic force applied to the individual cNT, the slender-body theory was adopted by modelling the cNT as a slender object. Moreover, magnetic simulation was performed to calculate the magnetic force applied to the residual Fe catalysis at one end of the cNT. These simulation results were combined and used to determine the critical height where the fluidic force was equal to the magnetic force. On the basis of these analyses, the array of cNT-assembled electrodes was implemented with a 2 m interval, whereas only a single cNT-assembled electrode was achieved in the previous work. A result of the present work, enables dense integration of the cNT circuit as a highly functional nanodevice.

关键词： microfluidics self-assembly carbon nanotubes nanomagnetics nanofabrication catalysts microfluidics magnetic self-assembly carbon nanotubes high-density integration residual iron catalyst fluid drag force slender-body theory magnetic simulation magnetic force catalysis cNT-assembled electrodes c

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Mesoscopic modelling of high T_c superconductors

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cURRENT OPINION IN SOLID STATE & MATERIALS ScIENcE 1997年第6期2卷 733-738页

作者： choy, Tc Monash Univ Dept Phys Clayton Vic 3168 Australia

Advances in experimental techniques, such as magneto-optical imaging, have influenced the way modelling studies are to be approached. In particular, these studies should be coupled with the fundamental understanding of flux lattices, vortex motion, melting and pinning, obtained from phenomenological theories and via various measurement techniques, such as Hall probe arrays, scanning superconducting quantum interference devices and by Lorentz microscopy. There are a range of models and questions to be addressed such as those concerning critical current density in relation to thin films. The ultimate goal is to obtain a cohesive picture of the properties of high T-c superconductors that will be useful from the standpoint of superconducting technology.

关键词： T c superconducting transition temperature

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Imaging adultc. eleganslive using light-sheet microscopy

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JOURNAL OF MIcROScOPY 2021年第3期281卷 214-223页

作者： Van Krugten, J. Taris, K. -K. H. Peterman, Erwin J. G. Vrije Univ Amsterdam LaserLaB Boelelaan 1081 NL-1081 HV Amsterdam Netherlands Vrije Univ Amsterdam Dept Phys & Astron Boelelaan 1081 NL-1081 HV Amsterdam Netherlands

Live observation of biological phenomena in the context of living organisms can provide important insights in the mechanisms of these phenomena. However, the spatially complex and dynamic physiology of multicellular organisms can be a challenging environment to make observations with fluorescence microscopy. Due to the illumination of out-of-focus planes, confocal and particularly widefield fluorescence microscopy suffer from low signal-to-background ratio (SBR), photo toxicity and bleaching of fluorescent probes. In light-sheet microscopy (LSM), solely the focal plane of the detection objective is illuminated, minimising out-of-focus fluorescence and photobleaching, thereby enhancing SBR, allowing for low laser intensities and longer acquisition periods. Here we present a straightforward light-sheet microscope with a 1.0-NA detection objective and a fast sample-positioning stage that allows for four degrees of freedom. By imaging the sensory cilia and nervous system of living young adultc. elegans, we demonstrate that the instrument is well suited for relatively fast, volumetric imaging of larger (hundreds of micrometres cubed) living samples. These experiments demonstrate that such an instrument provides a valuable addition to commonly used widefield and confocal fluorescence microscopes. Lay description In fluorescence microscopy, sharp images can only be obtained when the light obtained from the section of the image that is in focus is not overwhelmed by light emerging from elsewhere. In this paper, we present a light-sheet fluorescence microscope, based on the OpenSPIM initiative, with a magnification of 90x and a sensitive sample positioning stage that allows for fast controlled linear movement and rotation. In a light-sheet microscope (LSM), the sample is illuminated from the side, compared to the direction of detection, limiting illumination only to the part of the sample that is imaged in the focal plane (general resources: Wikipedia or MicroscopyU). This d

关键词： Biophysics c elegans fluorescence microscopy IFT light-sheet microscopy

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Modeling stem cell nucleus mechanics using confocal microscopy

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BIOMEcHANIcS AND MODELING IN MEcHANOBIOLOGY 2021年第6期20卷 2361-2372页

作者： Kennedy, Zeke Newberg, Joshua Goelzer, Matthew Judex, Stefan Fitzpatrick, clare K. Uzer, Gunes Boise State Univ Dept Mech & Biomed Engn 1910 Univ DrMSd 2085 Boise ID 83725 USA SUNY Stony Brook Biomed Engn Stony Brook NY 11794 USA

Nuclear mechanics is emerging as a key component of stem cell function and differentiation. While changes in nuclear structure can be visually imaged with confocal microscopy, mechanical characterization of the nucleus and its sub-cellular components require specialized testing equipment. A computational model permitting cell-specific mechanical information directly from confocal and atomic force microscopy of cell nuclei would be of great value. Here, we developed a computational framework for generating finite element models of isolated cell nuclei from multiple confocal microscopy scans and simple atomic force microscopy (AFM) tests. confocal imaging stacks of isolated mesenchymal stem cells were converted into finite element models and siRNA-mediated Lamin A/c depletion isolated chromatin and Lamin A/c structures. Using AFM-measured experimental stiffness values, a set of conversion factors were determined for both chromatin and Lamin A/c to map the voxel intensity of the original images to the element stiffness, allowing the prediction of nuclear stiffness in an additional set of other nuclei. The developed computational framework will identify the contribution of a multitude of sub-nuclear structures and predict global nuclear stiffness of multiple nuclei based on simple nuclear isolation protocols, confocal images and AFM tests.

关键词： Finite element analysis Mesenchymal stem cells Nucleus Mechanobiology Lamin A c chromatin confocal microscopy

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