Готові списки джерел за темами / 2-dimensional polymers

Добірка наукової літератури з теми "2-dimensional polymers"

Автор: Grafiati

Опубліковано: 6 вересня 2023

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Статті в журналах з теми "2-dimensional polymers"

Marchenko, Roman D., Taisiya S. Sukhikh, Alexey A. Ryadun, and Andrei S. Potapov. "Synthesis, Crystal Structure, and Luminescence of Cadmium(II) and Silver(I) Coordination Polymers Based on 1,3-Bis(1,2,4-triazol-1-yl)adamantane." Molecules 26, no. 17 (September 5, 2021): 5400. http://dx.doi.org/10.3390/molecules26175400.

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Coordination polymers with a new rigid ligand 1,3-bis(1,2,4-triazol-1-yl)adamantane (L) were prepared by its reaction with cadmium(II) or silver(I) nitrates. Crystal structure of the coordination polymers was determined using single-crystal X-ray diffraction analysis. Silver formed two-dimensional coordination polymer [Ag(L)NO3]n, in which metal ions are linked by 1,3-bis(1,2,4-triazol-1-yl)adamantane ligands, coordinated by nitrogen atoms at positions 2 and 4 of 1,2,4-triazole rings. Layers of the coordination polymer consist of rare 18- and 30-membered {Ag2L2} and {Ag4L4} metallocycles. Cadmium(II) nitrate formed two kinds of one-dimensional coordination polymers depending on the metal-to-ligand ratio used in the synthesis. Coordination polymer [Cd(L)2(NO3)2]n was obtained in case of a 1:2 M:L ratio, while for M:L = 2:1 product {[Cd(L)(NO3)2(CH3OH)]·0.5CH3OH}n was isolated. All coordination polymers demonstrated ligand-centered emission near 450 nm upon excitation at 370 nm.

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Dang, Ming-An, Zi-Feng Li, Ying Liu, and Gang Li. "Three Coordination Polymers Built by Methoxyphenyl Imidazole Dicarboxylate: Solvothermal Syntheses, Crystal Structures, and Properties." Australian Journal of Chemistry 68, no. 6 (2015): 956. http://dx.doi.org/10.1071/ch14159.

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Three coordination polymers [Sr(p-H2MOPhIDC)2]n (1) (p-H3MOPhIDC = 2-p-methoxyphenyl-1H-imidazole-4,5-dicarboxylic acid), {[Cd2(p-HMOPhIDC)2(4,4′-bipy)]⋅H2O}n (4,4′-bipy = 4,4′-bipyridine) (2), and [Zn(p-HMOPhIDC)(4,4′-bipy)]n (3) have been solvothermally synthesized, and structurally characterized by single-crystal X-ray diffraction. Polymer 1 indicates a three-dimensional framework, which can be simplified as a 6-connected lattice. Polymer 2 is also a three-dimensional framework, and contains mixed bridging ligands HMOPhIDC2– and 4,4′-bipy. Polymer 3 exhibits a sheet structure bearing infinite rectangles. The coordination modes of the p-H3MOPhIDC ligand, and the thermal and solid-state photoluminescence properties of the polymers have been investigated as well.

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Kadir, M. A., and Christopher J. Sumby. "Synthesis, Characterization and Crystal Structure of Coordination Polymers Developed as Anion Receptor." Solid State Phenomena 273 (April 2018): 134–39. http://dx.doi.org/10.4028/www.scientific.net/ssp.273.134.

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Reaction of diamide ligand, namelyN,N’-2,6-bis (4-pyridylmethyl) pyridine dicarboxamide (L) with cadmium nitrate and cadmium perchlorate has given rise to the formation of two types coordination polymers. Compound (CP1-Cd) with formula molecule {[Cd (L)2(H2O)2](NO3)2·6H2O}nis a one-dimensional coordination polymer while compound (CP2-Cd), with formula molecule {[Cd (L)2(H2O)2](ClO4)2·31⁄2H2O.CH3OH}n, is a two dimensional coordination polymer. These coordination polymers were preparedviaslow evaporation methods and completely characterized by combination of solid state techniques such as Fourier Transform Infrared (FTIR) spectroscopy, elemental analysis and X-ray crystallography. This study revealed that coordination polymers derived fromN,N’-2,6-bis (4-pyridylmethyl) pyridine dicarboxamide can accommodate anions with different sizes, showing good potential as anion receptor.

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Hsu, H. P., and P. Grassberger. "2-Dimensional polymers confined in a strip." European Physical Journal B - Condensed Matter 36, no. 2 (November 1, 2003): 209–14. http://dx.doi.org/10.1140/epjb/e2003-00337-6.

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Ullah, Ihsan, Jong Won Shin, Ryuya Tokunaga, Shinya Hayami, Hye Jin Shin, and Kil Sik Min. "Anion-Dependent Cu(II) Coordination Polymers: Geometric, Magnetic and Luminescent Properties." Crystals 12, no. 8 (August 5, 2022): 1096. http://dx.doi.org/10.3390/cryst12081096.

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A one-dimensional (1D) coordination polymer [Cu2(bpba)(CH3COO)4] (1) and a two-dimensional (2D) coordination polymer [Cu(bpba)2(H2O)(NO3)](NO3)∙2H2O∙MeOH (2) were synthesized by the reaction between Cu(CH3COO)2∙H2O/Cu(NO3)2∙3H2O and bis(4-pyridyl)benzylamine (bpba). The Cu(II) ions of 1 and 2 have distorted-square pyramidal coordination with a paddle-wheel structure and an octahedral geometry, respectively. By coordinating the Cu(II) ions and bpba ligands, 1 and 2 formed zigzag 1D and puckered 2D coordination polymers, respectively. Polymer 1 exhibits strong emissions at 355 and 466 nm, whereas polymer 2 exhibits strong emissions only at 464 nm. The emissions are strongly dependent on the geometry of the Cu(II) ions linked by the bpba and anionic ligands. Polymer 1 exhibits a very strong antiferromagnetic interaction within the paddle-wheel dimer, whereas polymer 2 exhibits a very weak antiferromagnetic interaction through the bpba linkers and/or space.

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Baek, Geunryeol, and Su-Chul Yang. "Effect of the Two-Dimensional Magnetostrictive Fillers of CoFe2O4-Intercalated Graphene Oxide Sheets in 3-2 Type Poly(vinylidene fluoride)-Based Magnetoelectric Films." Polymers 13, no. 11 (May 28, 2021): 1782. http://dx.doi.org/10.3390/polym13111782.

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In the last decade, magnetoelectric (ME) polymer films have been developed by including zero-dimensional or one-dimensional magnetostrictive fillers in a piezoelectric polymer matrix. Existing reports on ME polymer films reveal that the shape of the magnetostrictive fillers is a critical determinant of the polymeric phase conformation, strain transfer between the piezoelectric and magnetostrictive phases, and dipole alignment in the films. In this study, to investigate the effect of two-dimensional (2D) magnetostrictive fillers on piezoelectric, magnetic, and magnetoelectric responses, 3-2 type ME films were prepared using CoFe2O4-intercalated graphene oxide (CFO-i-GO) fillers and poly(vinylidene fluoride) (PVDF) polymers. The 2D fillers of CFO-i-GO were hydrothermally synthesized by CFO intercalation into the interlayers of GO sheets with different lateral sizes, which were controlled by ultrasonication treatment. It was found that the large-lateral-size GO (LGO), medium-lateral-size GO (MGO), and small-lateral-size GO (SGO) fillers in the PVDF-based ME films exhibited a lateral size effect on CFO intercalation, polymeric phase conformation, dipole alignment, and magnetoelectric responses. A maximum ME coefficient (αME) of 3.0 mV/cm∙Oe was achieved with a strong linearity (r2) of 0.9992 at an off-resonance frequency (f) of 1 kHz and applied direct current (dc) magnetic field (Hdc) of ± 1000 Oe. The 3-2 type polymer-based ME films with reliable ME responses have potential for use in high-feasibility ME devices for biomedical sensing applications.

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Xu, Chao, Sheng-Bo Liu, Taike Duan, Qun Chen, and Qian-Feng Zhang. "Syntheses, Structures and Photoluminescent Properties of the Two Novel Coordination Polymers [Cd(pydc)2(tu)]n and [Cd2(SO4)(nic)2(tu)1.5(H2O)2]n (pydc = Pyridine-2,3-dicarboxylate, nic = Nicotinate, tu = Thiourea)." Zeitschrift für Naturforschung B 66, no. 5 (May 1, 2011): 459–64. http://dx.doi.org/10.1515/znb-2011-0504.

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Two novel cadmium coordination polymers, [Cd(pydc)2(tu)]n (1) and [Cd2(SO4)(nic)2(tu)1.5 - (H2O)2]n (2) (pydc = pyridine-2,3-dicarboxylate, nic = nicotinate, tu = thiourea), have been synthesized under hydrothermal conditions and structurally characterized by X-ray diffraction analysis. 1 is a one-dimensional ladder coordination polymer in a two-dimensional network formed by hydrogen bonds. 2 consists of two kinds of Cd(II) centers in different coordination environments connected via nicotinate and sulfate to form a two-dimensional grid network integrated in a three-dimensional framework generated by hydrogen bonds. 2 shows intense fluorescent emission in the solid state at room temperature

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Leonor, Isabel B., Hyun Min Kim, Francisco Balas, Kawashita Masakazu, Rui L. Reis, Tadashi Kokubo, and Takashi Nakamura. "Formation of Bone-Like Apatite on Polymeric Surfaces Modified with -SO₃H Groups." Materials Science Forum 514-516 (May 2006): 966–69. http://dx.doi.org/10.4028/www.scientific.net/msf.514-516.966.

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Sulfonic groups (-SO3H) were covalently attached on different polymeric surfaces enabling them to induce apatite nucleation, for developing bioactive apatite-polymer composites with a bonelike 3-dimensional structure. High molecular weight polyethylene (HMWPE) and ethylene-co-vinyl alcohol co-polymer (EVOH) were used. The polymers were soaked in two types of sulphate-containing solutions with different concentrations, sulphuric acid (H2SO4) and chlorosulfonic acid (ClSO3H). To incorporate calcium ions into to the sulfonated polymers, the samples were soaked in a saturated Ca(OH)2 solution for 24 hours. After soaking of the samples in a simulated body fluid (SBF), formation of an apatite layer on both surfaces was observed. The results obtained prove the validity of the proposed concept and show that the -SO3H groups are effective on inducing apatite nucleation on the surface of these polymers.

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Brown, Matthew L., and Daniel B. Leznoff. "Expanding uranyl dicyanoaurate coordination polymers into the second and third dimensions." Canadian Journal of Chemistry 98, no. 7 (July 2020): 365–72. http://dx.doi.org/10.1139/cjc-2020-0031.

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The solvothermal synthesis and characterization of a three-dimensional, interpenetrated uranyl dicyanoaurate coordination polymer, K2(UO2)2(UO2)2(Au(CN)2)2(O)2(NO3)4, from UO2(NO3)2·6H2O and KAu(CN)2 is described. The structure contains a three-dimensional (3D) lattice of planar tetranuclear uranyl–oxo–nitrate clusters connected by dicyanoaurate linkers, with the rotation of the clusters providing the increased dimensionality. The material undergoes a reversible single-crystal to single-crystal transformation on exposure to water vapour, which is taken up in the channels of the 3D system. A second uranyl dicyanoaurate coordination polymer of the form [UO2(DMSO)3(H2O)(Au(CN)2)][Au(CN)2] was structurally characterized as a linear chain of dicyanoaurate units connected by gold–gold bonds with pendant uranyl–water–DMSO adducts that are hydrogen bonded into a two-dimensional sheet. Both materials exhibit emission arising from both the uranyl moiety and the gold(I) centre and represent the first multidimensional uranyl–dicyanoaurate coordination polymers.

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Choi, Junhwan, and Hocheon Yoo. "Combination of Polymer Gate Dielectric and Two-Dimensional Semiconductor for Emerging Field-Effect Transistors." Polymers 15, no. 6 (March 10, 2023): 1395. http://dx.doi.org/10.3390/polym15061395.

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Two-dimensional (2D) materials are considered attractive semiconducting layers for emerging field-effect transistors owing to their unique electronic and optoelectronic properties. Polymers have been utilized in combination with 2D semiconductors as gate dielectric layers in field-effect transistors (FETs). Despite their distinctive advantages, the applicability of polymer gate dielectric materials for 2D semiconductor FETs has rarely been discussed in a comprehensive manner. Therefore, this paper reviews recent progress relating to 2D semiconductor FETs based on a wide range of polymeric gate dielectric materials, including (1) solution-based polymer dielectrics, (2) vacuum-deposited polymer dielectrics, (3) ferroelectric polymers, and (4) ion gels. Exploiting appropriate materials and corresponding processes, polymer gate dielectrics have enhanced the performance of 2D semiconductor FETs and enabled the development of versatile device structures in energy-efficient ways. Furthermore, FET-based functional electronic devices, such as flash memory devices, photodetectors, ferroelectric memory devices, and flexible electronics, are highlighted in this review. This paper also outlines challenges and opportunities in order to help develop high-performance FETs based on 2D semiconductors and polymer gate dielectrics and realize their practical applications.

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Більше джерел

Дисертації з теми "2-dimensional polymers"

Olugebefola, Solar Candido Ademola. "Polyelectrolyte multilayers incorporating photocrosslinking polymers for controlling 2- and 3-dimensional structure." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40352.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.
Page 153 blank.
Includes bibliographical references (p. [146]-[152]).
Polyelectrolyte multilayer (PEM) assembly is a technology for building thin films with a number of useful and novel functionalities. PEMs interact favorably with proteins and other biomolecules making them potentially valuable as biomaterials. Many systems of polymers have been studied for use in PEMs, including weak polyelectrolytes such as those containing poly(acrylic acid) (PAA) and poly(allyamine hydrochloride) (PAH), which exhibit pH-dependent behavior. Properties such as thickness, swellability, mechanical stiffness, porosity (and by extention optical properties), and ability to adsorb small molecules are all controlled by the charge density of these polymers in the film and their resultant binding state. Patterning covalent binding through photo-crosslinking in addition to electrostatic binding, can locally override the native tendency to change structure with changes in pH. To achieve this, poly(acrylic acid) was chemically modified through a halide esterification reaction to incorporate photo-crosslinkable vinylbenzyl side groups, making poly(acrylic acid-ran-vinylbenzyl acrylate) (PAArVBA). The chemical modification was characterized by nuclear magnetic resonance spectroscopy (NMR) and light spectroscopy.
(cont.) NMR revealed that up to 6% of vinylbenzyl groups could be appended to PAA while maintaining the viability of the crosslinking group and the solubility of PAA in aqueous solution. Light spectroscopy indicated the location of the absorbance peak of the vinylbenzyl groups at 254 nm and the generation of crosslinking radicals was achieved with a quantum yield of 0.013. These parameters allow the polymer to be used in PEM films and to be crosslinked with a standard UV lamp, useful for practical applications. The effects of crosslinking on film thickness, swelling in aqueous solution, and mechanical stiffness were measured with ellipsometry, atomic force microscopy (AFM) and nanoindentation. Crosslinking was observed to limit the degree of film swelling in neutral and basic solutions. The patterning of swelling through UV exposure with masking was achieved with a resolution demonstrated down to 3 /m feature sizes. The mechanical stiffness of both crosslinked and as-built films was found to be less than that for equivalent films built with PAA, attributed to charge effects from the quarternary ammonium residue generated during the esterification reaction. The ability of crosslinked PAH/PAArVBA films to locally suppress induced film porosity was confirmed with ellipsometry, AFM and optical microscopy.
(cont.) The suppression effect was used to build two types of films with patterned optical Bragg reflection through alternation of porous and nonporous stacks in the direction normal to the film plane. Maximum reflectivities higher than 70% were generated from 3.5 stack films due to the unusually low refractive index in the porous regions, modeled as 1.09. Patterned structures, both porous and nonporous, were used to control the location of uptake of fluorescent dyes through increased affinity and surface area, as observed by fluorescence microscopy. Porous channel structures were used to direct dye uptake by controlling solvent transport through capillarity, enabling placement of two separate dyes in close proximity on a film surface without mixing. Finally, bovine serum albumin was used as a model protein to examine the effects of photocrosslinking and porosity on uptake and immobilization of proteins within PEM structures via fluorescence microscopy and radiolabeling. Porous thermally crosslinked films were found to adsorb significantly more protein than most other processing conditions and all films demonstrated retention of 80-95% of the adsorbed protein. Patterning of porosity gave selective control of the location of protein uptake.
by Solar Candido Ademola Olugebefola.
Ph.D.

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Haug, Nils Adrian. "Asymptotics and scaling analysis of 2-dimensional lattice models of vesicles and polymers." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/30706.

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The subject of this thesis is the asymptotic behaviour of generating functions of different combinatorial models of two-dimensional lattice walks and polygons, enumerated with respect to different parameters, such as perimeter, number of steps and area. These models occur in various applications in physics, computer science and biology. In particular, they can be seen as simple models of biological vesicles or polymers. Of particular interest is the singular behaviour of the generating functions around special, so-called multicritical points in their parameter space, which correspond physically to phase transitions. The singular behaviour around the multicritical point is described by a scaling function, alongside a small set of critical exponents. Apart from some non-rigorous heuristics, our asymptotic analysis mainly consists in applying the method of steepest descents to a suitable integral expression for the exact solution for the generating function of a given model. The similar mathematical structure of the exact solutions of the different models allows for a unified treatment. In the saddle point analysis, the multicritical points correspond to points in the parameter space at which several saddle points of the integral kernels coalesce. Generically, two saddle points coalesce, in which case the scaling function is expressible in terms of the Airy function. As we will see, this is the case for Dyck and Schröder paths, directed column-convex polygons and partially directed self-avoiding walks. The result for Dyck paths also allows for the scaling analysis of Bernoulli meanders (also known as ballot paths). We then construct the model of deformed Dyck paths, where three saddle points coalesce in the corresponding integral kernel, thereby leading to an asymptotic expression in terms of a bivariate, generalised Airy integral.

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Larsson, Anna-Karin. "Directed Enzyme Evolution of Theta Class Glutathione Transferase : Studies of Recombinant Libraries and Enhancement of Activity toward the Anticancer Drug 1,3-bis(2-Chloroethyl)-1-nitrosourea." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3545.

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Tran, Hiep Dai. "One-dimensional nanostructures of conducting polymers bulk synthesis and applications /." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1666392581&sid=7&Fmt=2&clientId=1564&RQT=309&VName=PQD.

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Hangarter, Carlos Maldonado. "Electrochemical synthesis of one-dimensional nanostructures for sensor and spintronic applications." Diss., [Riverside, Calif.] : University of California, Riverside, 2009. http://proquest.umi.com/pqdweb?index=0&did=1957308741&SrchMode=2&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1269278715&clientId=48051.

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Анотація:

Thesis (Ph. D.)--University of California, Riverside, 2009.
Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 12, 2010). Includes bibliographical references. Also issued in print.

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Hofmann, John. "Extension of the Method of Ellipses to Determining the Orientation of Long, Semi-flexible Fibers in Model 2- and 3-dimensional Geometries." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23921.

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Анотація:

The use of fiber-reinforced polymer composites formed via injection molding is of increasing interest due to their superior mechanical properties as compared to those of the polymer matrix alone. These mechanical properties, however, are strongly dependent on the fiber length and orientation distributions within a molded part. As such, there is a need to understand and model the orientation evolution of chopped fibers in flow in order to accurately simulate the final fiber orientation distribution within injection molded parts. As a result of this, accurate and reliable experimental measurement of fiber orientation is needed. Within this research, the application and validity of the Method of Ellipses for determining the orientation of long, semi-flexible glass fibers within injection molded composites has been investigated. A fiber suspension with an average length of approximately 3.9 mm was the focus of this study and assumed to be representative of commercial distributions. A novel method to quantify fiber curvature was developed and utilized to show that flexibility in center-gated disc and the end-gated plaque samples was minimal on average for the selected fiber length distribution. Thus, it was determined that the Method of Ellipses was applicable when utilized to obtain reliable orientation data for the selected long glass fiber suspension and within the chosen geometries that exhibit 1-, 2-, and 3-dimensional velocity fields. However, a modified image analysis width was found to be necessary in regions of highly aligned fibers, due to the increase in ellipse size and the need to reduce the number of partial objects and thus minimize error. This allowed for a direct comparison of the experimental orientation behavior of short and long glass fibers within the center-gated disc and the end-gated plaque, as well as the effect of the orientation distributions on the global modulus of the part.
Ph. D.

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Lundblad, Dan. "Studies on the antiproliferative action of interferon : effects on proteins synthesized in the G1 and S phase of the cell cycle in 2 anchorage-dependent cell lines." Doctoral thesis, Umeå universitet, Molekylärbiologi (Teknat- och Medfak), 1991. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-100575.

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Interferons (IFNs) are a class of structurally related proteins first discovered to be produced by virus-infected cells. By now, several other inducing agents have been described. IFNs exert multiple effects on cells exemplified by the establishment of an antiviral state, inhibition of cell proliferation and alteration of different immune reactions. In the present thesis the inhibition of cellular growth concentrated on effects in the early cell cycle have been studied. The human glioma cell line 251 MG was found to be blocked in the S phase of the cell cycle upon addition of IFN both to exponentially growing and growth-factor depleted, synchronized cells. Thymidine kinase and DNA-polymerase activities were reduced in parallel with the S phase effect. 2-5 oligo Anucleotides transfected into glioma cells lead to inhibition of cell growth, exponentially growing cells being blocked in the S phase as during IFN treatment. In contrast, synchronized, restimulated cells were blocked in the cellcycle phase where they resided at the time of transfection. As 2-5 oligo A synthetase activity was induced in the middle of the Gl phase, these results might indicate that the kinetics of expression of oligonucleotides after IFN additiondetermines the type of cell cycle block obtained in differenttumor cells. IFN inhibited preferentially proteins originating from newly synthesized mRNA in Sw 3T3 cells, c-mvc did not seem to be included among these proteins. In both cell systems c-myc expression was unaltered after IFN treatment. In clone T1 selected from the the Sw 3T3 cell line , c-mvc expression was uncoupled to growth and seemed to be growth factor independent. The change in c-myc expression in clone T1 compared to SW 3T3 cells did not render the cells sensitive to IFN. Hence, c-myc regulation does not seem to be the mechanism by which IFN regulates cell growth in this system. The proliferation marker KI-67 antigen was shown not to be causatively involved in growth inhibition of IFN. The reduced levels of the antigen was proposed to be a secondary effect caused by the G0/G1 arrest.

Diss. (sammanfattning) Umeå : Umeå universitet, 1991, härtill 6 uppsatser

digitalisering@umu

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Bej, Sujoy. "Itaconate Based Novel Amphiphilic Polymer Architectures." Thesis, 2022. https://etd.iisc.ac.in/handle/2005/5835.

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Amphiphiles are natural or synthetic molecules consisting of hydrophilic polar head group and hydrophobic non-polar hydrocarbon tail. Beyond a certain concentration, known as critical micellar concentration (CMC), amphiphilic molecules can self-assemble into a large variety of morphologies, such as spherical micelles, cylindrical micelles, reverse micelles, vesicles, lamellae etc.1 The idea of self-assembly is not limited to small molecule amphiphiles, but it can also be extended to the macromolecular amphiphiles often referred to as amphiphilic polymers, wherein both hydrophilic and hydrophobic segments are typically polymeric in nature. There is another type of amphiphile carrying a polymerizable unit at the junction of the immiscible segments, the polymerization of which results in the formation of amphiphilic brush type of polymers. In this context, I have utilized a biosourced starting material namely, itaconic acid to prepare several types of polymerizable amphiphiles, which upon polymerization leads to the formation of amphiphilic brush polymers with different architectures. In my presentation, I will discuss about few of those architecturally different amphiphilic brush polymers based on itaconate. First, I will talk about the crystallization induced gelation in amphiphilic double-brush polymers, where we show that the gel-sol transition temperature as well as mechanical properties can be easily tuned by varying the length of the hydrocarbon side chain from C12 to C18.2 Finally, as these gels are biocompatible, we have shown that insulin can be encapsulated within the hydrogel and can be released in sustained manner for diabatic treatment. In my second chapter, I will talk about core-shell type of amphiphilic brush polymers, wherein, I will discuss about the bulk properties of two types of core-shell type of polymers; in one case the hydrophilic segments at the core and hydrophilic segments at the shell, in another case the amphiphilicity is reversed. In chapter 3, I will present multiple attempts to generate 2 dimensionally crosslinked polymer nanosheet structures based on itaconate followed by investigation of their thermal as well as morphological properties. In the final chapter, I will talk about a different class of amphiphilic polymers with multiblock architecture carrying a diacetylene unit at the middle of the hydrophobic alkyl segment and explored the possibility of topochemical polymerization of the diacetylene within a single folded polymer chain with limited success.

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Chen, Hsin-chu, та 陳信助. "Fabrication and characterization of two dimensional nonlinear polymeric χ(2) photonic crystals". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/26060645302727617784.

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KE, SHIH-TING, and 柯仕廷. "Geometric and Electronic Structure Studies of One-Dimensional Coordination Polymer [FeII(Rtrz)3](DBS)2." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/4ss562.

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Анотація:

碩士
國立臺北科技大學
分子科學與工程系有機高分子碩士班
107
In this work, a series of one dimensional coordination polymers of [FeII(L)3](DBS)2 are synthesized and discussed, where L is 4-butadecyl-1,2,4-triazole (C14trz), 4-hexadecyl-1,2,4-triazole (C16trz), and 4-octadecyl-1,2,4-triazole (C18trz), and DBS is an anion of 4-dodecyl-benzenesulfonate. The complexes have spin crossover (SCO) behaviors, which are characterized by the temperature dependent measurements such as differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS) and superconducting quantum interference device (SQUID). Because the severe overlaps in diffraction peaks make the XRD pattern is hard to index, a new strategy is developed to resolve the structure by the combination with molecular mechanics calculations, Cambridge structure database, and the distances obtained from the Fe K-edge extended X-ray absorption fine structure (EXAFS). Based on this method, the reasonable 3-D structural models base on orthorhombic system are proposed for all three compounds with the orthorhombic cell constants around a ~ 50 Å, b ~ 7.38 Å, and c ~ 28 Å. According to the EXAFS results, the Fe is coordinated by six N atoms at the distance of Fe-N about 1.971(4) Å, 1.977(4) Å and 1.978(6) Å for C14trz, C16trz and C18trz complex, respectively. Meanwhile, the distance between two nearest Fe is 3.655(7) Å, 3.65(1) Å, and 3.67(1) Å for C14trz, C16trz and C18trz complex, respectively. The Fe-N distance is increased about 0.2 Å with the increasing temperature up to around 333K, 333K and 353K for C14trz, C16trz and C18trz complexes, respectively, which indicates the compound is transformed to high spin (HS) state. Moreover, with the result of Fe LIII,II-edge XAS multiplet simulation, the 10Dq is 0.4 eV at 400K for all the complexes, which is corresponding to the HS state (eff = 4.9 B.M.). On the other hand, the 10Dq is 2.4 eV at 80K, which eff is about 1.8 B.M.

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Частини книг з теми "2-dimensional polymers"

Schartel, Bernhard. "Influence of the Size and Dispersion State of Two-Dimensional Nanomaterials on the Fire Safety of Polymers." In Two-Dimensional Nanomaterials for Fire-Safe Polymers, 23–58. Boca Raton: CRC Press, 2023. http://dx.doi.org/10.1201/9781003327158-2.

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Chen, Yu, Pingkai Jiang, Jie Kong, and Xingyi Huang. "Chapter 2. Surface Engineering of Boron Nitride Nanoplatelets for Thermal Conductivity Enhancement of Polymers." In Two-dimensional Inorganic Nanomaterials for Conductive Polymer Nanocomposites, 52–98. Cambridge: Royal Society of Chemistry, 2021. http://dx.doi.org/10.1039/9781839162596-00052.

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Pardasani, R. T., and P. Pardasani. "Magnetic properties of triply bridged one-dimensional polymer of copper with acetate and 2, 5-bis(2-pyridyl)-pyrazine ligands." In Magnetic Properties of Paramagnetic Compounds, 75–76. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53974-3_36.

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Pardasani, R. T., and P. Pardasani. "Magnetic properties of triply bridged one-dimensional polymer of copper with benzoate and 2, 5-bis(2-pyridyl)-pyrazine ligands." In Magnetic Properties of Paramagnetic Compounds, 77–78. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53974-3_37.

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Pardasani, R. T., and P. Pardasani. "Magnetic properties of helical, one-dimensional copper(II) coordination polymer based on N-(2-hydroxybenzyl)glycine." In Magnetic Properties of Paramagnetic Compounds, Magnetic Susceptibility Data, Volume 4, 288–90. Berlin, Heidelberg: Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-662-62474-6_126.

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Pardasani, R. T., and P. Pardasani. "Magnetic properties of polymeric, two dimensional μ, 2, 2′-bipyrimidine, μ-oxalato bridged and μ-chloro-bridged copper(II) complex." In Magnetic Properties of Paramagnetic Compounds, 27–28. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-49202-4_10.

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Pardasani, R. T., and P. Pardasani. "Magnetic properties of helical, one-dimensional copper(II) coordination polymer based on N-(2-hydroxybenzyl)-L-alanine." In Magnetic Properties of Paramagnetic Compounds, Magnetic Susceptibility Data, Volume 4, 291–92. Berlin, Heidelberg: Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-662-62474-6_127.

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Han, Chang Dae. "Reaction Injection Molding." In Rheology and Processing of Polymeric Materials: Volume 2: Polymer Processing. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195187830.003.0017.

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Reaction injection molding (RIM) is a thermoset processing operation during which the incoming feedstream(s) undergo cure reactions that give rise to a three-dimensional network structure (Becker 1979; Macosko 1989). Different from the operation of injection molding thermoplastic polymers presented in Chapter 8, in RIM operation the component(s) must cure rapidly (say, within 90 seconds) and a finished product is removed in 1−10 minutes, depending on the chemical systems, the part thickness, and the capabilities of the processing machine. The chief advantages of RIM over the injection molding of thermoplastic polymers are: (1) large parts can be produced at low energy consumption, (2) large parts with varying cross sections with or without inserts can be produced without the problem of sink marks, and (3) lightweight parts, owing to the microcellular structure, can be produced. However, the predominant industrial applications are in the automotive industry; for instance, in the production of automobile fascia. In the 1970s and 1980s, very intensive research activities were reported on a better understanding of the RIM operation. Thermosets must meet with some stringent requirements for RIM operation. These are: (1) viscosities must be fairly low at processing temperature, so that a rapid injection of the feedstreams can be realized; (2) the feedstreams must have sufficient compatibility for efficient mixing by the static impingement mixing technique; (3) cure reaction must be sufficiently fast, such that a finished product can be removed in a very short time after injection is completed; (4) a finished product must have sufficient stiffness and resiliency at elevated temperatures; and (5) a finished product must be released easily from the mold surface, etc. It is then clear that not many thermosets meet these requirements. It has been found that urethanes, with proper chemistry of the components, meet with the requirements. For this reason, urethanes have been the most widely used resin for RIM, although other thermosets (e.g., epoxy) have also been used to some extent.

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Shahinpoor, Mohsen. "Review of Electrostrictive Materials." In Fundamentals of Smart Materials, 36–45. The Royal Society of Chemistry, 2020. http://dx.doi.org/10.1039/bk9781782626459-00036.

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Chapter 4 reviews the characteristics of electrostrictive materials. Electrostriction is defined as the electromechanical coupling in all electrical-nonconductors (dielectric materials). Under the application of an electric field, these materials show deformation, strain, and stress. Generally speaking, all electrostrictive materials exhibit second-order nonlinear coupling between the elastic strains or stresses and the dielectric terms such that the strain tensor is given by a nonlinear product of the vectors of the electric fields. For a single uniaxial strain (deformation), the induced strain (deformation) is directly proportional to the square of the applied electric field (voltage). Electrostrictive materials in the form of polymers have been the subject of much interest and research in recent years, and much of the focus has been on actuator configurations and how to enhance electromechanical activities. When an electric field is applied to a dielectric material, the differential elements and domains of the material are polarized and opposite sides of these domains become differently charged and attract each other, reducing the materials thickness in the direction of the applied field (and increasing thickness in the orthogonal directions due to the Poisson's ratio). The resulting strain tensor Sij (i, j=1, 2 3) is proportional to the product of the polarization vectors, Pk. For simple one-dimensional domains, the strain is proportional to the square of the applied electric field.

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Soares, Zilmar Timoteo, Amanda Araújo Nascimento, and Veronica Santos da Silva. "Biotechnology applied to the buriti fruit (Mauritia flexuosa Mart.)." In METHODOLOGY FOCUSED ON THE AREA OF INTERDISCIPLINARITY- V1. Seven Editora, 2023. http://dx.doi.org/10.56238/methofocusinterv1-020.

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Plastic has environmentally unfavorable factors. First, it is about its origin, coming from petroleum, a non-renewable source, hydrophobic materials that do not allow the action of microorganisms in its molecular chain, taking hundreds of years to decompose. In this sense, there is the buriti palm whose fruit is rich in natural polymer, which can be produced a biodegradable plastic, due to its organic characteristic, which decomposes easily and quickly causing without damage to the environment. With that, the. The objective of this research was to develop a flexible, biodegradable bioplastic based on natural polymers from renewable sources from the epicarp, mesocarp, buriti fruit endocarp and cassava starch by cooking process. Initially, a dimensional characterization of the buriti fruit was carried out with 120 individuals. Elaboration of different bioplastics with buriti fruit matrix in 90, 95 and 98% associated with cassava starch in 2, 5 and 10%, plasticized with glycerol. The characterizations of bioplastics were carried out through the evaluation of subjectivity, thickness, mechanical properties, opacity, color, water solubility, temperature resistance test, chemical resistance and biodegradation in water and soil. All bioplastics formed were visually transparent in 80% and opaque in 20%. With the increase in the addition of cassava starch, it caused an increase in thickness, permeability to water vapor and tensile strength, generating a decrease in their opacity. In evaluating the subjectivity of the samples, homogeneity was around 88.53%, flexibility 80% and deformation 8.6%. In the strength tests, the epicarp bioplastic showed low elongation (91.20 Mpa), while the endocarp showed greater elongation (4.41%) and low strength (42.50 Mpa). As for the evaluation of opacity, the endocarp exhibited a larger radius of 1.72cm, while the smallest length was manifested in the bioplastic epicarp 0.63cm. The bioplastics were subjected to temperatures of 60, 80, 100, 110 and 120°C, and in the first temperatures they remained at normal levels, from 100°C onwards, curvatures, dryness and cracks appeared. Based on these results, the concentrations of the mixture components were changed to allow the obtainment of decorative bioplastics, with adequate properties by the cooking process. Thus, it can be said that the production of composite bioplastics based on the epicarp, mesocarp and endocarp of the buriti fruit and added with cassava starch, plasticized with glycerol, by the cooking process is environmentally and economically viable.

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Тези доповідей конференцій з теми "2-dimensional polymers"

Garner, Sean, Vadim Chuyanov, Antao Chen, Srinath Kalluri, Felix Ignacio Marti-Carrera, William H. Steier, and Larry R. Dalton. "Three Dimensional Integrated Optics Using Polymers." In Organic Thin Films for Photonic Applications. Washington, D.C.: Optica Publishing Group, 1997. http://dx.doi.org/10.1364/otfa.1997.wa.4.

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Two dimensional integrated optical circuits have been demonstrated with considerable complexity and size. For example, 19x19 integrated star couplers1 have shown the large-scale routing capabilities of optical waveguides. As the two dimensional area and complexity of these circuits increases, problems can arise, for example, if the signals require similar optical time delays. The vertical integration of optical devices into a three dimensional structure can offer a significant increase in the integration density without increasing the time delays or the integration area. In 3-D integrated optics, one envisions several layers of 2-D integrated optics with the various layers coupled together vertically at appropriate locations by vertical waveguide bends, vertical waveguide power splitters, or vertical voltage controlled switches.

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Rebourt, E., B. Pepin-Donat, E. Dinh, F. Salhi, and M. Nechtschein. "The routes towards three dimensional fully conjugated conducting polymers: 2-preparation and characterization of conducting xerogels." In International Conference on Science and Technology of Synthetic Metals. IEEE, 1994. http://dx.doi.org/10.1109/stsm.1994.835327.

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Borovina, Ante, Rafael E. Hincapie Reina, Torsten Clemens, Eugen Hoffmann, Jonas Wegner, and Johannes Steindl. "Polymer Selection for Sandstone Reservoirs Using Heterogeneous Micromodels, Field Flow Fractionation and Corefloods." In SPE Improved Oil Recovery Conference. SPE, 2022. http://dx.doi.org/10.2118/209352-ms.

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Abstract Incremental oil recovery due to polymer flooding results from acceleration of oil production along flow paths and improving sweep efficiency. To achieve favorable economics, polymers should have a high viscosifying power and low adsorption. However, in addition, incremental oil production from various rock qualities needs to be maximized. We developed a workflow using a layered micromodel, corefloods and Field-Flow Fractionation (FFF) to determine the Molecular Weight Distribution (MWD) for the selection of polymers addressing heterogeneous reservoirs. We have designed micromodels consisting of two layers with different permeabilities, one four times larger than the other. The micromodel structure is based on the characteristics of a real sandstone core, with the dimensions 6 cm × 2 cm. These micromodels were used as preliminary screening of the polymers incorporating heterogeneity effects. Subsequently, single- and two-phase core experiments were performed to determine injectivity effects and displacement efficiency of the selected polymers. In addition, FFF was used to measure the molecular weight distribution, gyration radii and conformance of the polymers. Based on the workflow a polymer was selected. All polymers were tested at target viscosity at 7 1/s shear rate. Micromodel experiments showed that tested polymers are leading to improved sweep efficiency of heterogeneous structure. The displacement efficiency within the higher permeable layer was similar for the investigated polymers whereas the oil recovery from the lower permeable layer showed differences. FFF revealed that the MWD's of the tested polymers were different. The MWD of one of the polymers showed a large number of larger molecules compared with the other polymers. This polymer did not lead to the highest oil recovery in the micromodel. Injectivity and propagation of the higher MW polymer in both single- and two-phase core-floods was falling behind the other polymers. Measurements of the MWD of the core effluent showed that for all tested polymers the larger molecules are initially retained more than the smaller molecules. The polymer with the smallest molecules and narrow MWD showed the best propagation characteristics in the core. Owing to the good performance of this polymer in terms of sweep efficiency improvement, injectivity, and propagation, this polymer was selected for a field application. Therefore, the novelty presented here can be summarised as follow: Heterogeneous micromodels were used to screen polymers for one-dimensional displacement efficiency and sweep efficiency effects Single- and two-phase core floods in combination with Field-Flow Fractionation revealed the impact of the molecular weight distribution (MWD) on polymer injectivity, propagation and retention Selection of polymers need to include MWD to find the most effective polymer Polymer selection needs to take near-wellbore and reservoir effects (micro- and sweep efficiency in heterogeneous reservoirs) into account

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Srivastava, Vikas, and Lallit Anand. "On Modeling the Mechanical Behavior of Amorphous Polymers for the Micro-Hot-Embossing of Microfluidic Devices." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67135.

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In this paper, a brief summary of some of our recent work [1, 2] is presented, with the goal of developing an engineering science-based process-simulation capability for micro-hot-embossing of amorphous polymers. To achieve this goal: (i) a three-dimensional thermo-mechanically-coupled large deformation constitutive theory has been developed to model the temperature and rate-dependent elastic-viscoplastic response of amorphous polymers; (ii) the material parameters in the theory were calibrated by using new experimental data from a suite of simple compression tests on Zeonex-690R (cyclo-olefin polymer), that covers a wide range of temperatures and strain rates; (iii) the constitutive model was implemented in the finite element program ABAQUS/Explicit; and (iv) the predictive capability of the numerical simulation procedures were validated by comparing results from the simulation of a representative micro-hot-embossing process against corresponding results from a physical experiment.

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Blanchard, G. J., and J. P. Heritage. "Picosecond Stimulated Raman Measurement of Enhanced Optical Nonlinearities in a Conjugated Polymer." In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/up.1990.tha4.

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Conjugated polymers are of fundamental interest because they are model 1-dimensional semiconductors. They are also attractive candidate materials for nonlinear optical signal processing applications,[1] [2] [3] and they differ from 2-D III-V materials in one important way. The cross-sections of ground state fundamental vibration-to-exciton transitions are large for conjugated polymers, whereas they are typically small for III-Vs. The phonon-mediated nonlinear responses of each of these systems is determined by how strongly their phonons are coupled to the exciton resonance.

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Kingsley, David M., Andrew D. Dias, Douglas B. Chrisey, and David T. Corr. "A Novel, Laser-Based Technique to Fabricate and Precisely Pattern Cell-Encapsulated Alginate Microbeads." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14658.

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Microbeads are three-dimensional, generally spherical microstructures that are currently being investigated for applications in tissue engineering and for delivery of drugs, proteins, and DNA [1, 2]. Current microbead fabrication devices such as electrostatic bead generators, microfluidic devices, and micro-vibrators, function by using cross-linkable polymers into a crosslinking solution, such as calcium chloride in the case of alginate. These procedures allow for the controlled manipulation of microbead size, e.g., increasing electric field voltage for the electrostatic bead generator during polymer extrusion. Popular devices such as electrostatic bead generators are limited to polyelectrolyte materials because of the electric field extrusion method [3]. In addition, despite their ability to create monodispersed beads of different size, none of these technologies can precisely control microbead placement.

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Tabatabaei, Maryam, and Arash Dahi Taleghani. "Smart Lost Circulation Materials to Seal Large Fractures." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205873-ms.

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Abstract Lost circulation problems may result in a significant downtime, a considerable reduction of the rate of penetration, or even well control problems. Despite advances in manufacturing lost circulation materials (LCMs), some formations, like heavily fractured carbonates, have complete losses during drilling. We develop smart LCMs using shape memory polymers (SMPs), and program them thermo-mechanically to satisfy size limitations imposed by bottomhole assemblies (BHA). Elevated downhole temperatures act as an external trigger to recover the permanent shape of LCMs, which could expand ten times larger than the temporary (programmed) dimensions for deployment. Smart LCMs are a combination of various material categories such as granular, fibrous (one-dimensional or 1-D) and planar (two-dimensional or 2-D) configurations that resume to the original shape after exposure to high temperatures. The LCMs form different structures such as flatted pellet, disc-shaped, spider-shaped, and spindled, which, respectively, presents grains, 1-D fibers, 2-D stars, and 2-D lattices after recovery. A combination of the above categories attempt to build three-dimensional (3-D) plugging capabilities across various sized fractures.

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Northcutt, Robert G., and Vishnu-Baba Sundaresan. "Characterization of Electrochemical Capacity of a Biotemplated Polypyrrole Membrane." In ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3214.

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Recent studies of polypyrrole (PPy) electrodes have been increasing the interfacial surface area in order to increase electrochemical performance. We present a novel method of electropolymerizing PPy doped with dodecylbenzenesulfonate (DBS) referred to as biotemplating. A biotemplated conducting polymer utilizes phospholipid vesicles in order to form a three dimensional structure with a sponge-like shape. The vesicles, measuring 1–2 μm in diameter, are added in situ with the polymerization solution. They become enveloped while maintaining their structure during electropolymerization of PPy(DBS). The result of this structure is a significant increase in surface area compared to current techniques. There are several advantages in using biotemplated conducting polymers as battery electrodes. Compared to a planar PPy(DBS) membrane, biotemplated PPy(DBS) membranes have a roughly 50% increased storage capacity. There is an expected reduction in volumetric expansion during ion ingress/egress into the polymer backbone. This reduction would result in decreased fatigue loading and improving cyclability. Further, biotemplated PPy(DBS) membranes can be fabricated into thin structures with increased flexibility, allowing them to be rolled into various packaging sizes. In this article, the charge density of a biotemplated PPy(DBS) membrane as a function of charging and discharging currents is compared to a planar PPy(DBS) membrane. The structural enhancement offers systemic advantages by providing higher volumetric energy density and decreased fatigue loading for applications involving conducting polymer electrodes.

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Lu, Shengnan, Xilun Ding, and Gregory S. Chirikjian. "Rotations in a Non-Orthogonal Frame." In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-85862.

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This paper is concerned with describing the space of matrices that describe rotations in non-orthogonal coordinates. In scenarios such as in crystallography, conformational analysis of polymers, and in the study of deployable mechanisms and rigid origami, non-orthogonal reference frames are natural. For example, non-orthogonal vectors in the direction of atomic bonds in a molecule, the lattice coordinates of a crystal, or the directions of links in a mechanism are intrinsic. In these cases it is awkward to impose an artificial orthonormal reference frame rather than choosing one that is defined by the geometry of the object being studied. With these applications in mind, we fully characterize the space of all possible non-orthogonal rotations. We find that in the 2D case, this space is a three-dimensional subset of the special linear group, SL(2, R), which is itself a three-dimensional Lie group. In the 3D case we find that the space of nonorthogonal rotations is a seven-dimensional subspace of SL(3, R), which is an eight-dimensional Lie group. In the 2D case we use the Iwasawa decomposition to fully characterize the solution. In the 3D case we parameterize this seven-dimensional space by conjugating elements of the rotation group SO(3) by elements of a discrete family of of four-parameter subgroups of GL(3, R), and using this we derive an inversion formula to extract classical orthogonal rotations from those expressed in non-orthogonal coordinates.

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Delain, E., M. Barrav, J. Tapon-Bretaudière, F. Pochon, and F. Van Leuven. "THE MOLECULAR ORGANIZATION OF HUMAN ALPHA 2-MACROGLOBULIN. AN IMMUNO ELECTRON MICROSCOPIC STUDY WITH MONOCLONAL ANTIBODIES." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643864.

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Electron microscopy is a very convenient method to localize the epitopes of monoclonal antibodies (mAbs) at the surface of macromolecules for studying their tree-dimensional organization.We applied this immuno-electron microscopic method to human ct2-macroglobulin (ct2M). 29 anti-α2M mAbs have been tested with the four different forms of a2M : native and chymotrypsin-transformed tetramers, and the corresponding dimers, obtained by dissociation with divalent cations. These mAbs can be classified in three types : those which are specific for 1) the H-like transformed molecules, 2) the native molecules, and 3) those which can react with both forms of α2M.1) Among the H-like α2M specific mAbs, several react with the 20 kD-domain which is recognized by the cellular receptor of transformed a2M. This domain is located at the carboxyterminal end of each monomer. One IgG binds to the end of two adjacent tips of the H-like form.The other mAbs of this type bind to the α2M tips at non-terminal positions. Intermolecular connections built polymers of alternating α2M and IgG molecules.2) Among the native a2M-specific mAbs some are able to inhibit the protease-induced transformation of the native α2M. The binding sites of these mAbs are demonstrated on the native half-molecules. One of these mAbs was also able to react with transformed dimers, in a region corresponding very likely to an inaccessible epitope in the tetrameric transformed α2M molecule.3) Among the mAbs of this type, only two were able to inhibit the protease-induced transformation of α2M. Obviously, their epitopes should be close to the bait region of α2M. The other mAbs reacting with both α2M forms did not inhibit the α2M transformation.All these mAbs can be distinguished by the structure of the immune complexes formed with all forms of α2M. The epitopes are more easily located on the dimers and on the H-like transformed α2M than on the native molecules.From these observations, we propose a new model of the tree-dimensional organization of the human α2M in its native and transformed configurations, and of its protease-induced transformation.

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