Search results for "Statics"

Management of nasal septal abscess in childhood: our experience.

2004

Summary A nasal septal abscess is usually the result of an infected hematoma of the septum. A secondary septal abscess may be the result of infections extending from any of the neighbouring tissues. The necrosis of septal cartilage may lead to nasal deformities and severe impairment of nasal patency and growth. Objectives: Assess if the drainage of the abscess and the immediate reconstruction of the destroyed nasal septum in the acute phase is the best treatment to prevent short- and long-term effect on nasal and midface growth. Methods: Three pediatric patients treated with drainage and immediate implantation of homologous bank cartilage prior to 1990 and four treated with mosaic plastic u…

Modulating the polarization of broadband terahertz pulses from a spintronic emitter at rates up to 10 kHz

2021

Reliable modulation of terahertz electromagnetic waveforms is important for many applications. Here, we rapidly modulate the direction of the electric field of linearly polarized terahertz electromagnetic pulses with 1–30 THz bandwidth by applying time-dependent magnetic fields to a spintronic terahertz emitter. Polarity modulation of the terahertz field with more than 99% contrast at a rate of 10 kHz is achieved using a harmonic magnetic field. By adding a static magnetic field, we modulate the direction of the terahertz field between angles of, for instance, −53° and 53° at kilohertz rates. We believe our approach makes spintronic terahertz emitters a promising source for low-noise modula…

Hybrid Particle-Field Molecular Dynamics Simulations of Charged Amphiphiles in an Aqueous Environment.

2018

We develop and test specific coarse-grained models for charged amphiphilic systems such as palmitoyloleoylphosphatidylglycerol (POPG) lipid bilayer and sodium dodecyl sulfate (SDS) surfactant in an aqueous environment, to verify the ability of the hybrid particle-field method to provide a realistic description of polyelectrolytes. According to the hybrid approach, the intramolecular interactions are treated by a standard molecular Hamiltonian, and the nonelectrostatic intermolecular forces are described by density fields. Electrostatics is introduced as an additional external field obtained by a modified particle-mesh Ewald procedure, as recently proposed [Zhu et al. Phys. Chem. Chem. Phys.…

Electrostatic Interactions Between Colloidal Particles

2020

Mode expansion for the density profiles of crystal–fluid interfaces: hard spheres as a test case

2012

We present a technique for analyzing the full three-dimensional density profiles of a planar crystal-fluid interface in terms of density modes. These density modes can also be related to crystallinity order parameter profiles which are used in coarse-grained, phase field type models of the statics and dynamics of crystal-fluid interfaces and are an alternative to crystallinity order parameters extracted from simulations using local crystallinity criteria. We illustrate our results for the hard sphere system using finely-resolved, three-dimensional density profiles from density functional theory of fundamental measure type.

Cover Picture: Nanoscale Deposition of Single-Molecule Magnets onto SiO2 Patterns (Adv. Mater. 2/2007)

2007

The cover shows a schematic of scanning probe nanolithography based on the spatial confinement of an oxidation reaction within a water meniscus, and its application for fabricating ordered arrays of cationic Mn12 single-molecule magnets. Romero, Coronado, Garcia, and co-workers report on p. 291 that electrostatic interactions between the molecules and trapped charges within the nanodots drive the positioning of the molecules at the nanoscale.

Direct formation of Sub-Micron and Nanoparticles of a bioinspired coordination polymer based on Copper with Adenine

2017

We report on the use of different reaction conditions, e.g., temperature, time, and/or concentration of reactants, to gain control over the particle formation of a bioinspired coordination polymer based on copper(II) and adenine, allowing homogeneous particle production from microto submicro-, and up to nano-size. Additionally, studies on this reaction carried out in the presence of different surfactants gives rise to the control of the particle size due to the modulation of the electrostatic interactions. Stability of the water suspensions obtained within the time and pH has been evaluated. We have also studied that there is no significant effect of the size reduction in the magnetic prope…

Electrostatic backscattering by insulating obstacles

2012

AbstractWe introduce and analyze backscattering data for a three-dimensional obstacle problem in electrostatics. In particular, we investigate the asymptotic behavior of these data as (i) the measurement point goes to infinity and (ii) the obstacles shrink to individual points. We also provide numerical simulations of these data.

Dielectric response of nanoscopic spherical colloids in alternating electric fields: a dissipative particle dynamics simulation.

2012

We study the response of single nanosized spherical colloids in electrolyte solution to an alternating electric field (AC field) by computer simulations. We use a coarse-grained mesoscopic simulation approach that accounts in full for hydrodynamic and electrostatic interactions as well as for thermal fluctuations. The solvent is modeled as a fluid of single Dissipative Particle Dynamics (DPD) beads, and the colloidal particle is modeled as a rigid body made of DPD beads. We compute the mobility and the polarizability of a single colloid and investigate systematically the effect of amplitude and frequency of the AC-fields. Even though the thickness of the Debye layer is not "thin" compared t…

A Closer Look at the Comparative Statics in Competitive Markets

2005

In this paper we revisit the dual approach to comparative statics in competitive markets, allowing for the essential results to arise from a comprehensive and unified framework. We study, for both the long-run and the short-run, the response of all the endogenous variables to price factor changes in a way that captures the outputprice effects arising from market-firm interactions. We show that it is necessary a richer characterization of the nature of factors with respect to output, connected with marginal cost and output demand elasticities, for completely determining such responses.