Relevant bibliographies by topics / Bond polarization

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Bond polarization'

Author: Grafiati
Published: 4 June 2021
Last updated: 12 February 2022

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Journal articles on the topic "Bond polarization"

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Gudat, D. "A very peculiar family of N-heterocyclic phosphines: unusual structures and the unique reactivity of 1,3,2-diazaphospholenes." Dalton Transactions 45, no. 14 (2016): 5896–907. http://dx.doi.org/10.1039/c6dt00085a.

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Sun, Yu, Zi-Lin Yuan, Qian-Ze Li, Cai-Xin Zhang, Ke-Qiu Chen, and Li-Ming Tang. "Electrically controlled valley polarization in 2D buckled honeycomb structures." Modern Physics Letters B 35, no. 25 (August 3, 2021): 2150390. http://dx.doi.org/10.1142/s0217984921503905.

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Generating and manipulating valley polarization in a controlled method is significant. The inherently broken centrosymmetry of the buckled honeycomb structures gives it both ferroelectricity and valley degree of freedom, which provides an opportunity to realize electrically controlled valley polarization. In the first step, we explored the origin of buckling. The hexagonal structure is polar due to buckling of the surface, but the degree of buckling and the energy barrier to switching electric polarization are determined not solely by the chemical composition. We combined the electronegativity difference, bond length and the distribution of charge density to describe quantificationally the polarity of chemical bonds. It shows the characteristics of relatively long bond-length but relatively small electronegativity-difference. For exploring the ferroelectricity of buckling structures and the behavior of ferroelectric (FE) control of the valley degree of freedom, the [Formula: see text]-GaP is used as a model system to elucidate the strain effect on FE behavior and the magnetic proximity effect on the polarization and switching of valley. We found that the spontaneous polarization is positively correlated with the electronegativity difference within a certain range, and the compression strain can effectively manipulate spontaneous polarization and switch barrier. A combination of the magnetic proximity effect and the inversion of electric polarization can generate and switch valley polarization effectively.
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Rodina, A. V., A. A. Golovatenko, E. V. Shornikova, D. R. Yakovlev, and Al L. Efros. "Dangling bond spins controlling recombination dynamics of excitons in colloidal nanocrystals and nanoplatelets." Физика и техника полупроводников 52, no. 5 (2018): 500. http://dx.doi.org/10.21883/ftp.2018.05.45844.33.

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AbstractWe show theoretically that spins of dangling bonds (DBSs) at the surface of colloidal nanostructures can be responsible for the dark exciton radiative recombination governing low temperature photoluminecence. The DBS-assisted dark exciton recombination is efficient when all spins are randomly oriented. The DBS polarization caused by external magnetic field or by the formation of the dangling bond magnetic polaron (DBMP) at low temperatures suppresses the DBS-assisted recombination. The temperature or magnetic field control on the DBS-polarization allows to detect experimentally the presence of DBS and DBS-assisted recombination in CdSe nanocrystals and 2D nanoplatelets.
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Xiao, Xiao Hong, and Shi Chun Li. "Chemical Bonds Properties and Spontaneous Polarization of Orthogonal SrBi2Ta2O9 Crystals." Materials Science Forum 848 (March 2016): 688–95. http://dx.doi.org/10.4028/www.scientific.net/msf.848.688.

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The bonds structure, atomic coordination situation and local cluster structure in SrBi2Ta2O9 were analyzed by means of the Atomic Environment Calculation (AEC), and then the SrBi2Ta2O9 crystal was decomposed into 20 pseudo-binary crystals with the crystal decomposition method. The chemical bonds properties, such as effective valence electron density and iconicity of the individual bond were calculated by the dielectric chemical bonds theory. And the correlation between chemical bonds properties and spontaneous polarization of the bismuth layered ferroelectrics was established. Finally, the spontaneous polarization in ferroelectric SrBi2Ta2O9 and other relevant ferroelectrics were calculated, which are in good agreement with the experimental values and other theoretical calculated values.
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Sun, Chang Q. "Unprecedented O:⇔:O compression and H↔H fragilization in Lewis solutions." Physical Chemistry Chemical Physics 21, no. 5 (2019): 2234–50. http://dx.doi.org/10.1039/c8cp06910g.

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Charge injection in terms of protons, lone pairs, cations and anions by acid and base solvation mediates the HB network and properties of Lewis solutions through H↔H fragilization, O:⇔:O compression and polarization, ionic polarization and hydrating H2O dipolar screen shielding, anion–anion repulsion, compressed solvent H–O bond elongation and undercoordinated solute H–O bond contraction.
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Levine, Daniel S., and Martin Head-Gordon. "Energy decomposition analysis of single bonds within Kohn–Sham density functional theory." Proceedings of the National Academy of Sciences 114, no. 48 (November 20, 2017): 12649–56. http://dx.doi.org/10.1073/pnas.1715763114.

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An energy decomposition analysis (EDA) for single chemical bonds is presented within the framework of Kohn–Sham density functional theory based on spin projection equations that are exact within wave function theory. Chemical bond energies can then be understood in terms of stabilization caused by spin-coupling augmented by dispersion, polarization, and charge transfer in competition with destabilizing Pauli repulsions. The EDA reveals distinguishing features of chemical bonds ranging across nonpolar, polar, ionic, and charge-shift bonds. The effect of electron correlation is assessed by comparison with Hartree–Fock results. Substituent effects are illustrated by comparing the C–C bond in ethane against that in bis(diamantane), and dispersion stabilization in the latter is quantified. Finally, three metal–metal bonds in experimentally characterized compounds are examined: a MgI–MgI dimer, the ZnI–ZnI bond in dizincocene, and the Mn–Mn bond in dimanganese decacarbonyl.
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Mermer, Adrian, and Przemysław Starynowicz. "Charge-density distribution in potassium dihydrogen phosphoglycolate – a comparison of phosphate and phosphonate groups." Acta Crystallographica Section B Structural Science 68, no. 6 (October 23, 2012): 625–35. http://dx.doi.org/10.1107/s0108768112040724.

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Analysis of the experimental and theoretical charge-density distribution in potassium dihydrogen phosphoglycolate has been performed. The P—O bonds in the phosphate group are more polarized and the P atom is more positively charged than in phosphonate groups. The P—O bonds belong to a transit closed-shell (or polar covalent) class, while the ester C—O bond is a covalent (or shared-shell) bond. The coordination of potassium exerts a small effect on the phosphate group, whereas more pronounced changes, e.g. concerning the ellipticities of the C—O bonds, may be observed. The profiles of Laplacians and ellipticities give more insight in the polarization of the bonds.
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Miller, Ian J. "Semiclassical Quantum Mechanics, Bond Delocalization and the Mills - Nixon Effect." Australian Journal of Chemistry 50, no. 8 (1997): 795. http://dx.doi.org/10.1071/c96161.

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Conjugated π electrons in a ring system are described in terms of a transverse wave propagated along the carbon skeleton. Kekule benzene is forbidden because the π electron quantal wave self-interferes. The characteristics of an aromatic system are expressed in terms of the weighted combination of Kekule structures, and resonance energy occurs through combining canonical structures with conservation of momentum. The resonance energy of benzene is calculated as 1·045 times the energy difference between two carbon-carbon single bonds and one double bond, or 162 kJ/mol on one bond energy scheme. Bond localization is due to differences in wave impedance between zones represented by adjacent phase space cells; wave reinforcement occurs in one zone, cancellation in another as a consequence of the directional asymmetry of phase changes of the quantal wave. Quantal wave impedance can be altered by altering the localized potential, and it is proposed that the so-called Mills-Nixon effect arising from the annelation of bicyclic rings occurs because the bicyclic ring better focuses a polarization field. The polarization field arising as a consequence of strain is shown to semiquantitatively account for the bond alternation. The difference between exo and endo bond lengths in tris(bicyclo[2.1.1]hexeno)benzene is calculated to be 7·2 pm, compared with 9 pm as determined experimentally.
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Poier, Pier Paolo, and Frank Jensen. "Including implicit solvation in the bond capacity polarization model." Journal of Chemical Physics 151, no. 11 (September 21, 2019): 114118. http://dx.doi.org/10.1063/1.5120873.

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Jackson, Mark D. "Multipolar bond-polarization model for ions in crystalline solids." Ferroelectrics 111, no. 1 (November 1990): 49–56. http://dx.doi.org/10.1080/00150199008217600.

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Dissertations / Theses on the topic "Bond polarization"

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Abosrra, L. R. "Corrosion of steel reinforcement in concrete : corrosion of mild steel bars in concrete and its effect on steel-concrete bond strength." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/5417.

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This thesis reports on the research outcome of corrosion mechanism and corrosion rate of mild steel in different environments (saline, alkaline solutions and concrete media) using potentiodynamic polarization technique. The study also included the effect of corrosion on bond strength between reinforcing steel and concrete using pull-out test. Corrosion of mild steel and 316L stainless steel with different surface conditions in 1, 3 and 5% saline (NaCl + Distilled water) was investigated. Specimens ground with 200 and 600 grit silicon carbide grinding paper as well as 1μm surface finish (polished with 1μm diamond paste) were tested. In case of mild steel specimens, reduction in surface roughness caused increase in corrosion rate, while in 316L stainless steel corrosion rate decreased as the surface roughness improved. Metallographic examination of corroded specimens confirmed breakdown of passive region due to pitting corrosion. Corrosion of mild steel was also investigated in alkaline solution (saturated calcium hydroxide, pH =12.5) contaminated with 1, 3 and 5% saline. A series of corrosion experiments were also conducted to examine the efficiency of various concentrations of calcium nitrite (CN) on corrosion behaviour of both as-received and polished mild steel in alkaline solution containing 3% saline after 1 hour and 28 days of exposure. Corrosion rate was higher for the as-received than polished mild steel surface under the same testing conditions in NaCl alkaline solution with and without nitrites due to the effect of surface roughness. Morphology investigation of mild steel specimens in alkaline solution ii containing chlorides and nitrites showed localized pits even at nitrite concentration equal to chloride concentration. Corrosion of steel bars embedded in concrete having compressive strengths of 20, 30 and 46MPa was also investigated. The effect of 2 and 4% CN by weight of cement on corrosion behaviour of steel bar in low and high concrete strengths specimens were also studied. All reinforced concrete specimens were immersed in 3% saline solution for three different periods of 1, 7 and 15 days. In order to accelerate the chemical reactions, an external current of 0.4A was applied. Corrosion rate was measured by retrieving electrochemical information from polarization tests. Pull-out tests of reinforced concrete specimens were then conducted to assess the corroded steel/concrete bond characteristics. Experimental results showed that corrosion rate of steel bars and bond strength were dependent on concrete strength, amount of CN and acceleration corrosion period. As concrete strength increased from 20 to 46MPa, corrosion rate of embedded steel decreased. First day of corrosion acceleration showed a slight increase in steel/concrete bond strength, whereas severe corrosion due to 7 and 15 days corrosion acceleration significantly reduced steel/concrete bond strength. Addition of only 2% CN did not give corrosion protection for steel reinforcement in concrete with 20MPa strength at long time of exposure. However, the combination of good quality concrete and addition of CN appear to be a desirable approach to reduce the effect of chloride induced corrosion of steel reinforcement. At less time of exposure, specimens without CN showed higher bond strength in both concrete mixes than those with CN. After 7 days of corrosion acceleration, the higher concentration of CN gave higher bond strength in both concrete mixes. The same trend was observed at 15 days of corrosion acceleration except for the specimen with 20MPa compressive strength and 2% CN which recorded the highest deterioration in bond strength.
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Jakovkin, Igor [Verfasser], and B. [Akademischer Betreuer] Luy. "Protein Chemical Shift Tensor Calculation with Bond Polarization Theory : A New Approach for the Study of Orientation and Dynamics in Biological Systems / Igor Jakovkin. Betreuer: B. Luy." Karlsruhe : KIT-Bibliothek, 2011. http://d-nb.info/1014817781/34.

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Escalante, Otárola Wilfredo Gustavo. "Efeitos do fosfato ou silicato de cálcio no substrato dentinário erodido e nas propriedades do sistema adesivo autocondicionante Clearfil SE Bond /." Araraquara, 2020. http://hdl.handle.net/11449/192686.

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Orientador: Milton Carlos Kuga
Resumo: O objetivo do estudo foi avaliar o efeito de agentes remineralizantes à base de fosfato ou silicato de cálcio em formar precipitados e obstruir túbulos dentinários e seus efeitos sobre o colágeno da dentina erodida. Assim mesmo, avaliar seu efeito na resistência de união, formação de camada hibrida e penetrabilidade dentinária do sistema adesivo autocondicionante Clearfil SE Bond. Material e métodos: Trezentos espécimes foram obtidos do segmento cervical de incisivos bovinos e previamente submetidos à erosão dentinária. Os espécimes foram distribuídos em 5 protocolos (n=30): NP, Desensibilize NanoP; RD, MI Paste Plus RecaldentTM; NR, Regenerate NR-5TM; KF, Desensibilize KF 2% e CO, sem tratamento. Cada um dos protocolos foi aplicado no total de 4 sessões, com intervalos de 7 dias. Duzentos espécimes (n=20) foram diariamente submetidos ao desafio ácido, por imersão em suco de laranja, por 5 minutos e, posteriormente mantidos em saliva artificial. Na sequencia, cem espécimes foram analisados em microscopia eletrônica de varredura para avaliar a formação de precipitados sobre a superfície dentinária (500x) e obter o número de túbulos dentinários abertos (2,000x), e em microscopia EDX para obter resultados qualitativos sobre a composição do precitado, e avaliados por meio de microscopia de luz polarizada, com coloração picrosirius red, para qualificar a morfologia do colágeno da dentina após a conclusão do tratamento. Nos duzentos espécimes restantes (n=20), cem sem desafio ácido... (Resumo completo, clicar acesso eletrônico abaixo)
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Ramanathan, Chandrasekhar. "Biomedical solid state NMR : an ADRF cross polarization study of calcium phosphates and bone mineral." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38389.

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Bono, Jason S. "First Time Measurements of Polarization Observables for the Charged Cascade Hyperon in Photoproduction." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1520.

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The parity violating weak decay of hyperons offers a valuable means of measuring their polarization, providing insight into the production of strange quarks and the matter they compose. Jefferson Lab’s CLAS collaboration has utilized this property of hyperons, publishing the most precise polarization measurements for the Λ and Σ in both photoproduction and electroproduction to date. In contrast, cascades, which contain two strange quarks, can only be produced through indirect processes and as a result, exhibit low cross sections thus remaining experimentally elusive. At present, there are two aspects in cascade physics where progress has been minimal: characterizing their production mechanism, which lacks theoretical and experimental developments, and observation of the numerous excited cascade resonances that are required to exist by flavor SU(3)F symmetry. However, CLAS data were collected in 2008 with a luminosity of 68 pb−1 using a circularly polarized photon beam with energies up to 5.45 GeV, incident on a liquid hydrogen target. This dataset is, at present, the world’s largest for meson photoproduction in its energy range and provides a unique opportunity to study cascade physics with polarization measurements. The current analysis explores hyperon production through the γp → K+K+Ξ− reaction by providing the first ever determination of spin observables P, Cx and Cz for the cascade. Three of our primary goals are to test the only cascade photoproduction model in existence, examine the underlying processes that give rise to hyperon polarization, and to stimulate future theoretical developments while providing constraints for their parameters. Our research is part of a broader program to understand the production of strange quarks and hadrons with strangeness. The remainder of this document discusses the motivation behind such research, the method of data collection, details of their analysis, and the significance of our results.
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Rossi, Loïc. "Étude des nuages de Vénus par polarimétrie avec les données de l’instrument SPICAV-IR à bord de Venus Express." Thesis, Versailles-St Quentin en Yvelines, 2015. http://www.theses.fr/2015VERS041V/document.

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Vénus, bien que de taille et de masse très similaire à la Terre, se révèle en fait un monde infernaloù la température de surface atteint 700 K et la pression s’élève à 92 bars. De plus, l’atmosphèreest principalement composée de dioxyde de carbone (à plus de 90 %). Bien que le corps solide aitune période de rotation très lente et rétrograde, l’atmosphère est elle en superrotation avec unepériode de quatre jours environ au sommet des nuages, avec des vents zonaux pouvant atteindre100 m/s. Observée dans le visible, Vénus ne laisse pas voir sa surface, cachée sous d’épais nuagesd’acide sulfurique qui couvrent en permanence l’intégralité de la planète. Ces nuages jouent unrôle très important dans l’atmosphère vénusienne car ils sont fondamentaux dans le bilan radiatifde la planète de par leur opacité et leur albédo élevé mais aussi dans les cycles chimiques denombreuses espèces, notamment celui du soufre.Arrivée en orbite en avril 2006, la mission européenne Venus Express avait pour objectif d’étudieren détail l’atmosphère de la planète. Parmi ses instruments se trouvait le spectromètre SPICAVdont le canal infrarouge permettait de mesurer le degré de polarisation linéaire de la lumièrediffusée par les nuages. Cette thèse vise à l’exploitation de données acquises par SPICAV-IR quia fonctionné jusqu’à la fin de la mission Venus Express en 2014. Nous présentons la planète Vénuset plus particulièrement les propriétés des nuages qui l’entourent. Nous nous intéresseronsà la polarisation produite par la diffusion de la lumière dans les nuages avant d’expliquer commentSPICAV-IR la mesure. Nous présentons notre modèle de transfert de rayonnement prenanten compte la polarisation et nous analyserons les gloires observées par SPICAV-IR afin de caractériserles propriétés des nuages. Enfin, nous nous intéresserons à la variabilité spatiale des brumessituées au dessus des nuages
Venus is quite similar to Earth in terms of mass and radius, but it appears to be a hellish planetwith surface temperature reaching 700 K and pressions up to 92 bars. The atmosphere is mostlycomposed of carbon dioxyde and despite a slow retrograde rotating solid body, the atmosphereis in superrotation with a period of about four days and zonal winds reaching 100 m/s at cloudtop level. In visible light, the surface is always hidden by thick decks of clouds mostly madeof sulfuric acid. These clouds are very important in venusian climate as they play a key role inthe radiative balance of the planet because of their opacity and their high albedo and also in thechemical cycles of sulfur especially.In orbit since 2006, the European space agency’s probe Venus Express had the objective tostudy the atmosphere and clouds of Venus. Amongst its instruments was the SPICAV spectrometerwhich infrared channel had the ability to measure the degree of linear polarisation fromthe light scattered by the clouds. This thesis aims to study these observations acquired by SPICAVIRuntil the end of the mission in 2014.We will introduce the planet Venus with a particular focuson the cloud layers. We will then cover the principles of the polarisation of light through scatteringby cloud particles before we introduce the measurement of polarization by our instrument.We also introduce the radiative transfer model taking into account polarization and apply it tothe observations of a phenomenon called glory which allows to characterize the properties of thecloud droplets. We will then invesigate the variability of the haze layers lying above the maincloud deck
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Paradis, Mathieu. "Development and characterization of Poly(L-lactic acid) (PLLA) platforms for bone tissue engineering." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15771.

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Mestrado em Ciência e Engenharia de Materiais
The development of scaffolds based on biomaterials is a promising strategy for Tissue Engineering and cellular regeneration. This work focuses on Bone Tissue Engineering, the aim is to develop electrically tailored biomaterials with different crystalline and electric features, and study their impacts onto cell biological behavior, so as to predict the materials output in the enhancement of bone tissue regeneration. It is accepted that bone exhibits piezoelectricity, a property that has been proved to be involved in bone growth/repair mechanism regulation. In addition electrical stimulations have been proved to influence bone growth and repair. Piezoelectric materials are therefore widely investigated for a potential use in bone tissue engineering. The main goal is the development of novel strategies to produce and employ piezoelectric biomaterials, with detailed knowledge of mechanisms involved in cell-material interaction. In the current work, poly (L-lactic) acid (PLLA), a synthetic semi-crystalline polymer, exhibiting biodegradibility, biocompatibility and piezoelectricity is studied and proposed as a promoter of enhanced tissue regeneration. PLLA has already been approved for implantation in human body by the Food and Drug Administration (FDA), and at the moment it is being used in several clinical strategies. The present study consists of first preparing films with different degrees of crystallinity and characterizing these PLLA films, in terms of surface and structural properties, and subsequently assessing the behavior of cells in terms of viability, proliferation, morphology and mineralization for each PLLA configuration. PLLA films were prepared using the solvent cast technique and submitted to different thermal treatments in order to obtain different degrees of crystallinity. Those platforms were then electrically poled, positively and negatively, by corona discharge in order to tailor their electrical properties. The cellular assays were conducted by using two different osteoblast cell lines grown directly onto the PLLA films:Human osteoblast Hob, a primary cell culture and Human osteosarcoma MG-63 cell line. This thesis gives also a comprehensive introduction to the area of Bone Tissue Engineering and provides a review of the work done in this field in the past until today, in that same field, including the one related with bone’s piezoelectricity. Then the experimental part deals with the effects of the crystallinity degrees and of the polarization in terms of surface properties and cellular bio assays. Three different degrees of crystallinity, and three different polarization conditions were prepared; which results in 9 different configurations under investigation.
O desenvolvimento de scaffolds baseados em biomateriais é uma estratégia promissora para a engenharia de tecidos e entrega de fármacos. Este trabalho centra-se na engenharia de tecido ósseo, o objectivo é desenvolver biomateriais electricamente modificados, com diferentes valores de cristalinidade e propriedades eléctricas, e estudar o seu impacto no comportamento biológico da célula de modo a prever o efeito desses materiais na regeneração do tecido. É já amplamente conhecido o fato de o osso possuir características piezoeléctricas, e reconhecido que estas contribuem para os mecanismos de regulação do crescimento e reparação do tecido ósseo. Além disso é um facto aceite que a estimulação eléctrica também influencia o crescimento e reparação do osso. Os materiais piezoeléctricos apresentam assim vantagens quanto à sua utilização em engenharia de tecido ósseo, e têm vindo a ser estudados para esse efeito. No presente trabalho foram desenvolvidos filmes de ácido poli-L-láctico (PLLA), um polímero sintético semi-cristalino que é biocompatível, biodegradável, e piezoeléctrico, que se apresenta como promotor da regeneração óssea. O PLLA é um material aceite para implantes em humanos pela “Food and Drug Administration” (FDA), e está já a ser utilizado em várias estratégias e produtos para uso clínico. O presente estudo consiste numa primeira fase de preparação e caracterização de filmes de PLLA em termos de propriedades estruturais e de superfície, e numa segunda fase de avaliação do comportamento celular em termos de viabilidade, proliferação, morfologia e mineralização, para cada uma das configurações de PLLA obtidas. Os filmes foram preparados pelo método de evaporação do solvente com molde, e submetidos a diferentes tratamentos térmicos de forma a obter diferentes valores de cristalinidade. Estas plataformas foram depois electricamente polarizadas, positiva e negativamente, por meio de descarga de corona para modular as suas propriedades eléctricas. Os ensaios celulares foram realizados utilizando duas linhas celulares osteoblásticas, em contacto direto com as superfícies de PLLA: Osteoblastos Humanos - Hob, cultura primária de células, e linha de Osteosarcoma Humano - MG-63. Este trabalho também inclui uma introdução teórica para área da Engenharia de Tecido Ósseo, e resume o trabalho de investigação realizado nesta área até hoje incluindo aquele relacionado com a piezoelectricidade do tecido ósseo. A parte experimental dedica-se aos efeitos do grau de cristalinidade e da polarização nas propriedades de superfície do material e nos ensaios biológicos. Foram estudadas nove configurações, originadas por três valores de cristalinidade: 0, 7 e 35%, e três tipos de polarização: positiva, negativa e neutra (apenas com o tratamento térmico análogo).
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Doležal, Jan. "Minimalizace vlivu rušení na bezdrátovou síť." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217521.

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This thesis is concerned the technology with technologies of transfer through wireless devices. It is about possibilities of optimization of transfer in wireless net, especially of the reduction of interference influence. The first part is about theory and the standards development of wireless technology. There are methods and principles used in wireless technologies. The second part is a practical measuring and testing of an internal wireless net, with the emphasis being on the source of interference influence. Measuring was focused on interference between access points and was not about meteorological influence. It continues with theory and testing of interference of the microwave oven in our wireless net. Then, it is a practical demonstration of interference in an external environment. There are practical examples of interference between different providers’ nets on the same area and solutions to prevent or to cancel this interference. In next part of work the wireless net is parsed and described in a given territory. Here is described the way how to precede the reciprocal interference and eventually how this mutual disturbance suppress. Consequently, our net is optimized for customer growth and for today’s options of newer and more powerful components for wireless transfer. Finally there are two laboratory tasks. The first one is about practical measuring and testing of wireless net’s parameters and the second one is about simulation of wireless networks in the Opnet program.
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Naue, Janine. "Histologische Charakterisierung eines murinen Knorpeldestruktionsmodells in der BALB/c Maus." Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-184744.

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Die rheumatoide Arthritis ist eine chronisch-entzündliche Bindegewebserkrankung mit symmetrischem Befall der Gelenke. Die genaue Ätiologie ist bisher unbekannt. Aktivierte synoviale Fibroblasten sollen durch gesteigerte Adhäsion und Produktion von proinflammatorischen Zytokinen und Matrix-lysierenden Proteasen maßgeblich an der Gelenkdestruktion beteiligt sein. Ziel dieser Arbeit war es, ein neues in-vivo-Knorpeldestruktions-Modell zu etablieren, in welchem unter immunkompetenten Bedingungen, die Invasion und Destruktion von Gelenkknorpel durch die Fibroblasten-Zelllinie LS48 über einen längeren Zeitraum simuliert werden kann. Die am Institut für klinische Immunologie der Medizinischen Fakultät der Universität Leipzig etablierte Zelllinie LS48 wurde in die ipsilateralen Kniegelenke von BALB/c-Mäusen injiziert. Die dadurch induzierte Gewebsdestruktion wurde über zehn Wochen in zweiwöchigem Abstand histopathologisch beurteilt und klassifiziert. Als vergleichende Fibroblasten-Zelllinie wurden nicht-invasive NIH/3T3-Zellen eingesetzt. An Hand der Score-Parameter Zellinvasion, Pannusformation und Knorpeldestruktion wurde eine mäßige bis schwer-wiegende Gewebsdestruktion durch die LS48-Zellen bereits ab der zweiten Untersuchungswoche lichtmikroskopisch nachgewiesen, ohne dass dabei pathologische Effekte in den kontralateralen Kniegelenken aufgetreten sind. Polarisationsmikroskopisch wurden für den Parameter Knorpeldestruktion vergleichbare Ergebnisse erzielt. Damit wurde gezeigt, dass das Modell BALB/c LS48 ein erfolgversprechendes Instrument darstellt, das zur Testung neuer therapeutischer Strategien gegen die Gelenkdestruktion verwendet werden kann. Inwieweit die Auseinandersetzung der LS48-Zellen mit dem spezifischen Immunsystem der BALB/c-Maus Auswirkungen auf den Verlauf der Gewebsdestruktion hat, sollte in weiterführenden Experimenten untersucht werden.
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Iffländer, Tim. "Electronic and Magnetic Properties of the Fe/GaAs(110) Interface." Doctoral thesis, 2015. http://hdl.handle.net/11858/00-1735-0000-0028-86DE-A.

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Books on the topic "Bond polarization"

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1937-, Berkhuijsen Elly M., ed. Galactic foreground polarization: Proceedings of a workshop held in Bonn, 7-9 September 1998. Bonn, Germany: Max-Planck-Institut für Radioastronomie, 1999.

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Nugent, Elizabeth R. After Repression. Princeton University Press, 2020. http://dx.doi.org/10.23943/princeton/9780691203058.001.0001.

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In the wake of the Arab Spring, newly empowered factions in Tunisia and Egypt vowed to work together to establish democracy. In Tunisia, political elites passed a new constitution, held parliamentary elections, and demonstrated the strength of their democracy with a peaceful transfer of power. Yet in Egypt, unity crumbled due to polarization among elites. Presenting a new theory of polarization under authoritarianism, the book reveals how polarization and the legacies of repression led to these substantially divergent political outcomes. The book documents polarization among the opposition in Tunisia and Egypt prior to the Arab Spring, tracing how different kinds of repression influenced the bonds between opposition groups. It demonstrates how widespread repression created shared political identities and decreased polarization — such as in Tunisia — while targeted repression like that carried out against the Muslim Brotherhood in Egypt led opposition groups to build distinct identities that increased polarization among them. This helps explain why elites in Tunisia were able to compromise, cooperate, and continue on the path to democratic consolidation while deeply polarized elites in Egypt contributed to the rapid reentrenchment of authoritarianism. Providing vital new insights into the ways repression shapes polarization, the book helps to explain what happened in the turbulent days following the Arab Spring and illuminates the obstacles to democratic transitions around the world.
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Ricciardi, Victor. The Psychology of Speculation in the Financial Markets. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780190269999.003.0026.

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This chapter discusses the role of speculation in the financial markets that influences individual and group behavior in the form of bubbles and crashes. The chapter highlights behavioral finance issues associated with bubbles, such as overconfidence, herding, group polarization, groupthink effect, representativeness bias, familiarity issues, grandiosity, excitement, and the overreaction and underreaction to prices. These issues are important for understanding past financial mistakes because history often repeat itself. The chapter also examines the aftermath of the financial crisis of 2007–2008 on investor psychology, including the impact of a severe financial downturn, anchoring effect, recency bias, worry, loss averse behavior, status quo bias, and trust. The aftermath of the financial crisis might have negative long-term effects on investor psychology in which some investors remain overly risk averse, resulting in under-investment in stocks and over-investment in cash and bonds.
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Book chapters on the topic "Bond polarization"

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Sternberg, Ulrich, and Wolfram Prieß. "Extremely Fast Calculation of13C Chemical Shift Tensors Using the Bond Polarization Theory." In Modeling NMR Chemical Shifts, 93–100. Washington, DC: American Chemical Society, 1999. http://dx.doi.org/10.1021/bk-1999-0732.ch006.

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Chung, Won-jin, and Scott E. Denmark. "Bifunctional and Synergistic Catalysis: Lewis Acid Catalysis and Lewis Base-Assisted Bond Polarization (n→ σ* )." In Lewis Base Catalysis in Organic Synthesis, 1213–58. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527675142.ch25.

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Goddard, William A. "Charges and Polarization Without QM." In Computational Materials, Chemistry, and Biochemistry: From Bold Initiatives to the Last Mile, 1073–77. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-18778-1_46.

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Pineda-Torra, Inés, Matthew Gage, Alba de Juan, and Oscar M. Pello. "Isolation, Culture, and Polarization of Murine Bone Marrow-Derived and Peritoneal Macrophages." In Methods in Molecular Biology, 101–9. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4939-2929-0_6.

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Wu, Hao, and Rainer Glauben. "Fatty Acid–Driven Polarization of Suppressive Bone Marrow–Derived Macrophages Including Metabolic and Functional Analysis." In Methods in Molecular Biology, 197–207. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1350-4_14.

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Gopinath, T., and Gianluigi Veglia. "Experimental Aspects of Polarization Optimized Experiments (POE) for Magic Angle Spinning Solid-State NMR of Microcrystalline and Membrane-Bound Proteins." In Methods in Molecular Biology, 37–53. New York, NY: Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4939-7386-6_2.

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Morrow, Gary W. "Brief Organic Review." In Bioorganic Synthesis. Oxford University Press, 2016. http://dx.doi.org/10.1093/oso/9780199860531.003.0004.

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In addition to simple hydrocarbon structures (alkanes, alkenes, alkynes, and aromatic systems) and alkyl groups (methyl, ethyl, propyl, isopropyl, etc.), this text assumes a familiarity with the most common functional groups associated with organic chemical structures and their basic reactivity patterns. Table 1.1 summarizes the names and structures of some of the more important functional groups we will be dealing with throughout the remainder of the book. It is important to remember that functional groups containing O or N with nonbonding electrons have an affinity for both protic and Lewis acids and are important participators in H-bonding. Groups containing a carbonyl (C=O) function are especially important, as these bonds are strongly polarized (δ+C=Oδ–), the C atom being electron deficient and the O atom electron excessive; this strong polarization is mainly responsible for the familiar reactivity patterns associated with carbonyl compounds. Figure 1.1 depicts the standard classification of isomers in organic chemical structures. Recall that constitutional isomers are compounds with the same molecular formula but different atom connectivity, such as 1-butanol versus 2-butanol. Stereoisomers, on the other hand, are compounds with the same formula and the same atom connectivity, differing from one another only in the three-dimensional orientation of their atoms in space. These are divided into two groups: enantiomers and diastereomers. Enantiomers are nonsuperimposable mirror image molecules whose asymmetry is usually the result of a tetrahedral carbon atom with four different atoms or groups attached to it, as in the 2-butanol enantiomers. Such chiral molecules rotate the plane of polarized light either (+) or (−) and so are said to be optically active. Achiral molecules, such as 1-butanol, do not rotate the plane of polarized light and so are optically inactive. A standard formalism for representation of a chiral center is to use bond line drawings with two of the four atoms or groups lying in the plane of the paper, a third projecting outward (wedge bond), and the fourth projecting inward (dashed bond).
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Módis, László. "The Organic Bone Matrix." In Organization of the Extracellular Matrix: a Polarization Microscopic Approach, 99–121. CRC Press, 2018. http://dx.doi.org/10.1201/9781351075282-5.

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Friedrichs, Gordon M. "Polarized at Home, Bound to Lead Abroad." In U.S. Global Leadership Role and Domestic Polarization, 1–26. Routledge, 2020. http://dx.doi.org/10.4324/9781003089476-1.

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Li, Yi-Ping, Mengrui Wu, and Wei Chen. "Osteoclast Activity: Bone Resorption, Polarization, Acidification, Proton Pumps, and Chloride Channels." In Encyclopedia of Bone Biology, 251–72. Elsevier, 2020. http://dx.doi.org/10.1016/b978-0-12-801238-3.11165-1.

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Conference papers on the topic "Bond polarization"

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Sternberg, Ulrich, Frank-Thomas Koch, and Margit Möllhoff. "Atomic properties derived from the bond polarization theory." In The first European conference on computational chemistry (E.C.C.C.1). AIP, 1995. http://dx.doi.org/10.1063/1.47768.

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Lall, Pradeep, and Sungmo Jung. "Reliability Assessment of Cu-Al WB Under High Temperature and High Voltage Bias Application." In ASME 2020 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/ipack2020-2678.

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Abstract Electronics in automotive underhood environments may be subjected to high temperature in the range of 125–200°C. Transition to electric vehicles has resulted in need for electronics capable of operation under high voltage bias. Automotive electronics has simultaneously transitioned to copper wire-bond from gold wire-bond for first-level interconnections. Copper has a smaller process window and a higher propensity for corrosion in comparison with gold wire bonds. There is scarce information on the reliability of copper wire bonds in presence of high voltage bias under operation at high temperature. In this paper, a multiphysics model for micro galvanic corrosion in the presence of chlorine is introduced. The diffusion cell is used to measure the diffusivity of chlorine in different pH values and different temperatures. Diffusivity measurements are incorporated into the 3D ionic transport model to study the effect of different environmental factors on the transport rate of chlorine. The tafel parameters for copper, aluminum and intermetallics have been extracted through measurements of the polarization curves. The multiple physics of ionic transport in presence of concentration gradient, potential gradient is coupled with the galvanic corrosion.
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Lall, Pradeep, Yihua Luo, and Luu Nguyen. "Multiphysics Model for Chlorine-Ion Related Corrosion in Cu-Al Wirebond Microelectronic Packages." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-53742.

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The increasing price of gold has resulted in industry interest in use of copper as alternative wire bonds interconnect material. Copper wire has the advantages of the lower cost, lower thermal resistivity, lower electrical resistivity, higher mechanical strength and higher deformation stability over the gold wire. In spite of the upside above, the Cu-Al wire bond is susceptible to the electrolytic corrosion and the reliability of Cu-Al wire bond is of great concern. Typical electronic molding compounds are hydrophilic and absorb moisture when exposed to humid environmental conditions. EMC contain ionic contaminants including chloride ions as a result of the chemical synthesis of the subcomponents of the resin, etching of metallization and the decomposition of the die-attach glue. The presence of moisture in the operating environment of semiconductor package makes the ion more mobile in the EMC. The migration of chloride ions to the Cu-Al interface may induce electrolytic corrosion inside the package causing degradation of the bond interface resulting in eventual failure. The rate at which the corrosion happens in the microelectronic packages is dependent upon the rate at which the ions transport through the EMC in addition to the reaction rate at the interface. In this effort, a multiphysics model for galvanic corrosion in the presence of chloride has been presented. The contaminant diffusion along with the corrosion kinetics has been modeled. In addition, contaminated samples with known concentration of KCl contaminant have been subjected to the temperature humidity conditions of 130°C/100RH. The resistance of the Cu-Al interconnects in the PARR test have been monitored periodically using resistance spectroscopy. The diffusion coefficients of chloride ion has been measured in the electronic molding compound at various temperatures using two methods including diffusion cell and inductively coupled plasma (ICPMS). Moisture ingress into the EMC has been quantified through measurements of the weight gain in the EMC as a function of time. Tafel parameters including the open circuit potential and the slope of the polarization curve has been measured for both copper, aluminum under different concentrations of the ionic species and pH values in the EMC. The measurements have been incorporated into the COMSOL model to predict the corrosion current at the Cu-Al bond pad. The model predictions have been correlated with experimental data.
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Han, Jiahua, and Hongtan Liu. "AB Initio Simulation on Grotthuss Mechanism." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81340.

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Ab initio simulations on Grotthuss mechanism have been carried out. Using the simulation results together with the existing experimental data, all the popular propositions for Grotthuss mechanism, including the one recently proposed by Noam [1], have been checked. Combining with the charge distribution calculation and the movement of the positive charge center inside the protonated water cluster during the proton diffusion process, only one mechanism is shown probable, while all the other proposed mechanisms are excluded. According to this probable mechanism, the high mobility of proton inside water is caused by the high diffusion rate of H5O2+, while the diffusion of H5O2+ is mainly induced by the thermal movement of water molecules at the second solvation shell of H5O2+ cation and the Zundel polarization inside the cation ion. Furthermore, the external field and thermo-dynamic effects play important roles during the transport process by affecting the reorientation of water molecules at the neighborhood of the second solvation shell of H5O2+ to induce the Zundel polarization and by providing the energy for the cleavage of the hydrogen bond between a newly formed water molecule and H5O2+. Because the weight (fraction) of H5O2+ among protonated water clusters decreases as temperature increases, this proposed mechanism is considered to play the dominant role only when temperature is below 572 K, above which, protons transport by other mechanisms become dominant.
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Chakraborty, Rajib, Susmita Datta, Mohammad Shahid Raza, and Partha Saha. "Improvement of Ionic Bonding Strength and Electrochemical Corrosion Resistance of Hydroxyapatite- Calcium Phosphate Pulsed Electrochemically Deposited In-Situ Coating Through Hydroxyl Ion Treatment." In ASME 2018 13th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/msec2018-6582.

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Hydroxyl ion treatment of different hydroxyapatite-calcium hydrogen phosphate composite in-situ coatings synthesized through pulsed electro-deposition with varying amount of hydroxyapatite phase and degree of crystallinity were carried out with the help of highly basic solution in order to achieve a more chemically stable and corrosion resistance performance under contact with body fluid. The coatings exhibit altogether completely different behaviour in terms of bond formation, surface topography generation, phase transformation and corrosion behaviour. Detailed characterizations of formed top surface layer were carried out with the help of XRD, SEM and FTIR in order to correlate the results with their base surface characteristics. Transformation of <020> and <121> surface parallel planes of calcium hydrogen phosphate in to <002> and <112> planes of hydroxyapatite took place in all the coatings along with formation of nano-crystalline structure. Calcium-rich porous hydroxyapatite scaffold formation takes place in low current density coating which in general exhibits low stability in terms of chemical bonding strength vis-à-vis corrosion protection performance. 10 mA/cm2 coating, which come with optimum presence of hydroxyapatite phase and crystallinity post electro-deposition, showed significant improvement in terms of increasing hydroxyl and phosphate bond polarization strength of hydroxyapatite phase and the same lead to improvement in the overall corrosion resistance performance of the coating by two times. Despite of formation of highest amount of hydroxyapatite phase during hydroxyl ion treatment in 20 mA/cm2 coatings, the corrosion protection performance results are negative on account of dilution of mostly low bonding amorphous phases with high internal residual stress.
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Andrade, Karine N. de, Amanda R. P. Costa, Rodolfo I. Teixeira, Micaeli L. da S. Moreira, José Walkimar M. Carneiro, Nanci C. L. Garden, Fernanda da C. S. Boechat, Maria Cecília B. V. de Souza, Pedro N. Batalha, and Rodolfo G. Fiorot. "Photophysical characterization of 3-acyl-4-quinolones." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202006.

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4-quinolones derivatives can present fluorescent properties, depending on their substituents and on the chemical environment (e.g., acidic medium), allowing their application as ion sensors. We theoretically evaluated the photophysical properties of previously synthesized 3-acyl-4-quinolones to verify how different substituents (R1=H, NH2 and R2 = OEt, OH, NHPh) affect their absorption profiles and the emission profile of a reference compound, PB3. All DFT and TD-DFT calculations were performed at B3LYP-D3/6-311++G(d,p) level and continuum polarization model for simulated acetonitrile as solvent. For PB2 (R1 = H, R2 = OEt), we observed hypsochromic shift compared to PB3 due to the increase of the gap between HOMO/LUMO (absence of electron-donating group), in accordance with experimental data. For R1=NH2 and R2=OH, NHPh (PB6 and PB10, respectively), the gap between HOMO/LUMO increases, resulting in a soft bathochromic shift for the simulated absorption spectra. In addition, we evaluated the effect of acid addition on the absorption and emission profile of PB3 and the results were compared with experimental data. Our thermodynamic results suggest that protonation occurs on the endocyclic carbonyl of the quinolone moiety, probably due to an increased aromatic character, as suggested by our NICS calculations. Finally, we associate the increase of the fluorescence in the acidic medium to the establishment of an intramolecular hydrogen bond and, thus, increased rigidity.
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Huang, Xiang-Run, and Robert W. Knighton. "Polarization Properties of the Retinal Nerve Fiber Layer." In Biomedical Optical Spectroscopy and Diagnostics. Washington, D.C.: OSA, 2000. http://dx.doi.org/10.1364/bosd.2000.suh4.

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Han, Li-Hsin, Tingji Tang, and Shaochen Chen. "Photo-Deformable Micro-Shells of Nanometer Thick." In ASME 4th Integrated Nanosystems Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/nano2005-87059.

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Azobenzene is a chemical structure that directly transmits energy of ultraviolet (UV) light, through an isomerization between the trans and cis states of a double bond between two nitrogen atoms, to a mechanical effect that reduces its molecular length from 9.0 Å to 5.5 Å [1]. This phenomenon has been applied in the fabrication of photo-deformable polymers, where monomers containing azobenzene were polymerized to form gel-like materials [1, 2, 3]. The mechanism of photo-isomerization could be very promising for the field concerning nano/micro-electro-mechanical-system (MEMS/NEMS) [4]. Layer-by-layer (LBL) method [5, 6] is a method to form thinfilms of nanometer-scale thickness through a series of adsorptions of poly-anions and poly-cations onto a charged template. 3-dimensional (3D) hollow shells can be formed by casting the LBL film onto small particles and subsequently etching away the particles. [7–11]. This report is about a combination between the photoisomerization phenomenon and LBL method. Silica micro-spheres (6.84 μm in diameter) were used as templates. In a series of LBL procedures, poly- (1- 4- 3 carboxy- 4- hydroxyphenyl azobenzene sulfonaide-1, 2-ethanediyl, sodium salt) (PAZO) and poly-allylamine hydrochloride (PAH, a poly-cation) solutions were alternatively deposited onto the surfaces of the micro-spheres. Details of the procedures followed reference [9]. After 20 PAZO/PAH double layers were formed, we etched away the SiO2 cores by using 6:1 buffered hydrofluoride acid (BHF) and successfully formed 3-dimemsional (3D) hollow shells (Figure 1). We used a 355 nm Nd:YAG pulse-laser to irradiate the micro-shells. The microshells contracted anisotropically under the laser irradiation, and the shape of microshells changed from spherical to ellipsoidal. The long axes of the contracted microshell are parallel to the direction of the polarization of the UV laser (Figure 2). We believe that this anisotropic deformation is generated from a polarization dependence of the photo-isomerization rate of the azobenzene groups in the microshells. The deformed micro-shells were tested by irradiation of a 532nm pulse laser. The contraction, however, is not recoverable even through cis-trans isomerization was shown generated by visible-light irradiation [3]. To solve this problem, further study is needed to investigate the details of the micro-shells’ deformation. Nevertheless, we think it is quite possible that the irreversibility was resulted from the migrations and re-adhesions between the polyelectrolyte molecules during the UV irradiation. We believed that this kind of technique is very promising for the development micro and nanomachines (MEMS/NEMS). For instance, the large volumic shrinkage of the micro-shells could be applied to the field concerning nano-robots, artificial muscles, or drug delivery systems.
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Schneider, Blair B., and Georgios P. Tsoflias. "GPR Polarization Effects of Buried Bison Bone." In SEG Technical Program Expanded Abstracts 2017. Society of Exploration Geophysicists, 2017. http://dx.doi.org/10.1190/segam2017-17682555.1.

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Mehrübeoǧlu, Mehrübe, Nasser Kehtarnavaz, Gerard L. Coté, Sohi Rastegar, and Lihong V. Wang. "Diffuse Reflectance Polarization Images of Turbid Media Affected by Glucose." In Biomedical Optical Spectroscopy and Diagnostics. Washington, D.C.: OSA, 1998. http://dx.doi.org/10.1364/bosd.1998.btuc4.

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