Symmetry breaking and electrostatic attraction between two identical surfaces

By allowing the surface charge of one surface to affect the adsorption equilibrium of the other, we establish the existence of a long-range attractive interaction between two identical surfaces in an electrolyte containing polyvalent counterions with a mean-field Poisson-Boltzmann approach. A Stern electrostatic condition from linearization of the mass-action adsorption isotherm is used to capture how polyvalent ion condensation affects and reverses the surface charge. We furthermore establish a direct mapping between this Stern-layer condition and previously derived modified mean-field formulations associated with correlated fluctuations theory. For a sufficiently potential-sensitive isotherm, antisymmetric charge inversion can occur to produce an attractive force that increases with decreasing ionic strengths. Analyses of a mass-action isotherm produce force-separation relations, including an exponential far-field force decay distinct but consistent with previously proposed correlated fluctuation theories and in quantitative agreement with experimental data

Broadband converging plasmon resonance at a conical nanotip

We propose an analytical theory which predicts that Converging Plasmon Resonance (CPR) at conical nanotips exhibits a red-shifted and continuous band of resonant frequencies and suggests potential application of conical nanotips in various fields, such as plasmonic solar cells, photothermal therapy, tip-enhanced Raman and other spectroscopies. The CPR modes exhibit superior confinement and ten times broader scattering bandwidth over the entire solar spectrum than smooth nano-structures. The theory also explicitly connects the optimal angles and resonant optical frequencies to the material permittivities, with a specific optimum half angle that depends only on the real permittivity for high-permittivity and low-loss materials

Asymmetric Adjustments in the Ethanol and Grains Markets

This paper examines the long- and short-run asymmetric adjustments for nine pairs of spot and futures prices, itemized as three own pairs for three different bio-fuel ethanol types, three own pairs for three related agricultural products, namely corn, soybeans and sugar, and three cross pairs that included hybrids of the spot price of each of the agricultural products and an ethanol futures price. Most of the spreads’ asymmetric adjustments generally happen during narrowing. The three ethanol pairs that contain the eCBOT futures with each of Chicago spot, New York Harbor spot and Western European (Rotterdam) spot show different long-run adjustments, arbitrage profitable opportunities and price risk hedging capabilities. The asymmetric spread adjustments for the three grains are also different, with corn spread showing the strongest long-run widening adjustment, and sugar showing the weakest narrowing adjustment. Among others, the empirical analysis indicates the importance of potentially hedging the spot prices of agricultural commodities with ethanol futures contracts, which sends an important message that the ethanol futures market is capable of hedging price risk in agricultural commodity markets. The short-run asymmetric adjustments for individual prices in the nine pairs (with exception of the corn own pair underscore the importance of futures prices in the price discovery and hedging potential, particularly for ethanol futures.Long-run and short-run asymmetric adjustments; ethanol; agricultural products; arbitrage opportunities; hedging; widening and narrowing adjustment

A WIRE LOOP DESIGN FOR CONVECTION-ENHANCED DIELECTROPHORETIC BIOPARTICLE TRAPPING

ABSTRACT Tailor-designed AC electro-osmotic (AC-EO) stagnation flows are used to convect bioparticles globally from a bulk solution to localized dielectrophoretic (DEP) traps that are aligned at flow stagnation points. The multi-scale trap, with a typical trapping time of seconds for a one cc sample, is several orders of magnitude faster than conventional DEP traps and earlier AC-EO traps with disjoint electrodes. A novel serpentine wire resistor loop capable of sustaining a high field, up to 20,000 V/cm, is fabricated to produce strong AC electro-osmotic flow with two separated stagnation lines, one aligned with the field minimum and one with the field maximum. The continuous loop design allows a large applied voltage without inducing Faradaic electrode reactions. Particles are trapped within seconds at one of the traps depending on whether they suffer negative or positive DEP (n-DEP, p-DEP). The particles can also be rapidly released from their respective traps (and recaptured in the opposite traps) by varying the frequency of the applied AC field below particle-distinct cross-over frequencies. Zwitter ion addition to the buffer allows further geometric and frequency alignments of the AC-EO and DEP motions. The same device hence allows fast trapping, detection sorting and characterization of a sample with realistic conductivity, volume and bacteria count. INTRODUCTION In the last decade, the advent of micro-fluidic research has spawned a new array of lab-on-a-chip technologies operating at length scales typically on the order of tens of microns. However, there has been relatively little success in developing portable technologies that can rapidly detect, distinguish, and analyze dilute solutions of bioparticles such as bacteria or viruses. Current bioparticle analysis techniques typically rely on labor intensive culturing or PCR amplification to first increase the concentration of a dilute sample. Culturing is then routinely followed by a relatively fast and accurate assay involving fluorescent antibodies, magnetic beads, or fluorescent nanoprobes. While such tests are usually quick, taking only several minutes

Applying Information Integration Theory on the Modeling of Price Forecasting – An Example of Online Trading on Ebay

Because of the booming of internet technology and the great promotion internet portal, on-line exchange is more popular in the recent years. This study attempts to integrate concepts of Information Integrate Theory; Anchoring and Adjustment Method to explore the buyer’s trade behavior between two different cultures. After observing the historical data on Yahoo’s Taiwan and Yahoo’s America, the anchoring effect and order effect during the process of a C2C auction is proposed in this study. Chinese buyers seem willing to pay much their attention on pricing during the whole process of an auction than American people do. But, the same phenomenon does exist for American doing a bid on a higher-priced luxury commodity. It sounds for a luxury product, there is a common pricing strategy existed between people of two different cultures. The results provide a very promised direction for knowledge capture and decision analysis for trading, and more works for data mining on pricing for different commodities, cultures, or other kinds of variables related to products and members of market might be a possible future approach for building a knowledge management system for a pricing mechanism for the market

Asymmetric Adjustments in the Ethanol and Grains Markets

This paper examines the long- and short-run asymmetric adjustments for nine pairs of spot and futures prices, itemized as three own pairs for three different bio-fuel ethanol types, three own pairs for three related agricultural products, namely corn, soybeans and sugar, and three cross pairs that included hybrids of the spot price of each of the agricultural products and an ethanol futures price. Most of the spreads' asymmetric adjustments generally happen during narrowing. The three ethanol pairs that contain the eCBOT futures with each of Chicago spot, New York Harbor spot and Western European (Rotterdam) spot show different long- run adjustments, arbitrage profitable opportunities and price risk hedging capabilities. The asymmetric spread adjustments for the three grains are also different, with corn spread showing the strongest long-run widening adjustment, and sugar showing the weakest narrowing adjustment. Among others, the empirical analysis indicates the importance of potentially hedging the spot prices of agricultural commodities with ethanol futures contracts, which sends an important message that the ethanol futures market is capable of hedging price risk in agricultural commodity markets. The short-run asymmetric adjustments for individual prices in the nine pairs (with exception of the corn own pair underscore the importance of futures prices in the price discovery and hedging potential, particularly for ethanol futures.Long-run and short-run asymmetric adjustments, ethanol, agricultural products, arbitrage opportunities, hedging, widening and narrowing adjustment.

Fundamental Processes of Atomization in Fluid-Fluid Flows

This paper discusses our proposed experimental and theoretical study of atomization in gas-liquid and liquid-liquid flows. While atomization is a very important process in these flows, the fundamental mechanism is not understood and there is no predictive theory. Previous photographic studies in (turbulent) gas-liquid flows have shown that liquid is atomized when it is removed by the gas flow from the crest of large solitary or roll waves. Our preliminary studies in liquid-liquid laminar flows exhibit the same mechanism. The two-liquid system is easier to study than gas-liquid systems because the time scales are much slower, the length scales much larger, and there is no turbulence. The proposed work is intended to obtain information about the mechanism of formation, rate of occurrence and the evolving shape of solitary waves; and quantitative aspects of the detailed events of the liquid removal process that can be used to verify a general predictive theory

Asymmetric Adjustment in the Ethanol and Grains Markets

This paper examines the long- and short-run asymmetric adjustments for nine pairs of spot and futures prices, itemized as three own pairs for three different bio-fuel ethanol types, three own pairs for three related agricultural products, namely corn, soybeans and sugar, and three cross pairs that included hybrids of the spot price of each of the agricultural products and an ethanol futures price. Most of the spreads’ asymmetric adjustments generally happen during narrowing. The three ethanol pairs that contain the eCBOT futures with each of Chicago spot, New York Harbor spot and Western European (Rotterdam) spot show different long-run adjustments, arbitrage profitable opportunities and price risk hedging capabilities. The asymmetric spread adjustments for the three grains are also different, with corn spread showing the strongest long-run widening adjustment, and sugar showing the weakest narrowing adjustment. Among others, the empirical analysis indicates the importance of potentially hedging the spot prices of agricultural commodities with ethanol futures contracts, which sends an important message that the ethanol futures market is capable of hedging price risk in agricultural commodity markets. The short-run asymmetric adjustments for individual prices in the nine pairs (with exception of the corn own pair underscore the importance of futures prices in the price discovery and hedging potential, particularly for ethanol futures