Frequency mixing and phase detection functionalities of three-terminal ballistic junctions

Three-terminal ballistic junctions (TBJs) are fabricated from a high-mobility InP/In0.75Ga0.25As heterostructure by electron-beam lithography. The voltage output from the central branch is measured as a function of the voltages applied to the left and right branches of the TBJs. The measurements show that the TBJs possess an intrinsic nonlinearity. Based on this nonlinearity, a novel room-temperature functional frequency mixer and phase detector are realized. The TBJ frequency mixer and phase detector are expected to have advantages over traditional circuits in terms of simple structure, small size and high speed, and can be used as a new type of building block in nanoelectronics.

Studies of effect of phase volume ratio on transfer of ionizable species across the water/1,2-dichloroethane interface by a three-electrode setup

The electrochemical behavior of pyridine distribution at the water/1,2-dichloroethane interface with variable phase volume ratios (r=V-0/V-W) was investigated by cyclic voltammetry. The system was composed of an aqueous droplet supported on a Ag/AgCl disk electrode covered with an organic solution or an organic droplet supported on a Ag/AgTPBCl disk electrode covered with an aqueous solution. In this way, a conventional three-electrode potentiostat can be used to study an ionizable compound transfer process at a liquid/liquid interface with a wide range of phase volume ratios (from 0.0004 to 1 and from 1 to 2500). Using this special cell we designed, only very small volumes of both phase were needed for r equal to unity, which is very useful for the investigation of the distribution of ionizable species at a biphasic system when the available amount of species is limited. The ionic partition diagrams were obtained for different phase volume ratios.

Study of ionizable drugs transfer across the water/1,2-dichloroethane interface with phase volume ratio equal to unity using a three-electrode system

The electrochemical behavior of ionizable drugs (Amitriptyline, Diphenhydramine and Trihexyphenedyl) at the water/1,2-dichloroethane interface with the phase volume ratio (r = V-o/V-w) equal to 1 are investigated by cyclic voltammetry. The system is composed of an aqueous droplet supported at an Ag/AgCl disk electrode and it was covered with an organic solution. In this manner, a conventional three-electrode potentiostat can be used to study the ionizable drugs transfer process at a liquid/liquid interface. Physicochemical parameters such as the formal transfer potential, the Gibbs energy of transfer and the standard partition coefficients of the ionized forms of these drugs can be evaluated from cyclic voltammograms obtained. The obtained results have been summarized in ionic partition diagrams, which are a useful tool for predicting and interpreting the transfer mechanisms of ionizable drugs at the liquid/liquid interfaces and biological membranes.

Prediction of soil adsorption coefficients from retention parameters on three reversed-phase liquid chromatographic columns

Reversed-phase high-performance liquid chromatographic (RP-HPLC) retention parameters, which are determined by the intermolecular interactions in retention process, can be considered as the chemical molecular descriptors in linear free energy relationships (LFERs). On the basis of the characterization and comparison of octadecyl-bonded silica gel (ODS), cyano-bonded silica gel (CN), and phenyl-bonded silica gel (Ph) columns with linear solvation energy relationships (LSERs), a new multiple linear regression model using RP-HPLC retention parameters on ODS and CN columns as variables for estimation of soil adsorption coefficients was developed. It was tested on a set of reference substances from various chemical classes. The results showed that the multicolumn method was more promising than a single-column method was for the estimation of soil adsorption coefficients. The accuracy of the suggested model is identical with that of LSERs.

Three Hundred Years in Annapolis: Phase III Archaeological Investigations of the Anne Arundel County Courthouse Site (18AP63), Annapolis, Maryland

During the summer of 1994, Archaeology in Annapolis conducted archaeological investigations of the city block bounded by Franklin, South and Cathedral Streets in the city of Annapolis. This Phase III excavation was conducted as a means to identify subsurface cultural resources in the impact area associated with the proposed construction of the Anne Arundel County Courthouse addition. This impact area included both the upper and lower parking lots used by Courthouse employees. Investigations were conducted in the form of mechanical trenching and hand excavated units. Excavations in the upper lot area yielded significant information concerning the interior area of the block. Known as Bellis Court, this series of rowhouses was constructed in the late nineteenth century and was used as rental properties by African-Americans. The dwellings remained until the middle of the twentieth century when they were demolished in preparation for the construction of a Courthouse addition. Portions of the foundation of a house owned by William H. Bellis in the 1870s were also exposed in this area. Construction of this house was begun by William Nicholson around 1730 and completed by Daniel Dulany in 1732/33. It was demolished in 1896 by James Munroe, a Trustee for Bellis. Excavations in the upper lot also revealed the remains of a late seventeenth/early eighteenth century wood-lined cellar, believed to be part of the earliest known structure on Lot 58. After an initially rapid deposition of fill around 1828, this cellar was gradually covered with soil throughout the remainder of the nineteenth century. The fill deposit in the cellar feature yielded a mixed assemblage of artifacts that included sherds of early materials such as North Devon gravel-tempered earthenware, North Devon sgraffito and Northem Italian slipware, along with creamware, pearlware and whiteware. In the lower parking lot, numerous artifacts were recovered from yard scatter associated with the houses that at one time fronted along Cathedral Street and were occupied by African- Americans. An assemblage of late seventeenth century/early eighteenth century materials and several slag deposits from an early forge were recovered from this second area of study. The materials associated with the forge, including portions of a crucible, provided evidence of some of the earliest industry in Annapolis. Investigations in both the upper and lower parking lots added to the knowledge of the changing landscape within the project area, including a prevalence of open space in early periods, a surprising survival of impermanent structures, and a gradual regrading and filling of the block with houses and interior courts. Excavations at the Anne Arundel County Courthouse proved this to be a multi-component site, rich in cultural resources from Annapolis' Early Settlement Period through its Modern Period (as specified by Maryland's Comprehensive Historic Preservation Plan (Weissman 1986)). This report provides detailed interpretations of the archaeological findings of these Phase III investigations.

From Boys to Men Phase Three Key Findings

The From Boys to Men Project was funded by the Economic and Social Research
Council to explore why some boys become domestic abuse perpetrators when
others do not. In so doing, it sought to establish what more could be done to
reduce the number of young men who become perpetrators. The study
involved three phases of data collection including: Phase 1 - a survey of school
children aged 13-14, Phase 2 - focus groups with 69 young people aged 13-19,
and Phase 3 - life history interviews with 30 young men, aged 16-21, who
had experienced domestic violence as victims, perpetrators or witnesses.

Three-dimensional, fully adaptive simulations of phase-field fluid models

We present an efficient numerical methodology for the 31) computation of incompressible multi-phase flows described by conservative phase-field models We focus here on the case of density matched fluids with different viscosity (Model H) The numerical method employs adaptive mesh refinements (AMR) in concert with an efficient semi-implicit time discretization strategy and a linear, multi-level multigrid to relax high order stability constraints and to capture the flow`s disparate scales at optimal cost. Only five linear solvers are needed per time-step. Moreover, all the adaptive methodology is constructed from scratch to allow a systematic investigation of the key aspects of AMR in a conservative, phase-field setting. We validate the method and demonstrate its capabilities and efficacy with important examples of drop deformation, Kelvin-Helmholtz instability, and flow-induced drop coalescence (C) 2010 Elsevier Inc. All rights reserved

Power losses analysis and cooling system design of three topologies of multilevel inverters

This paper presents the comparison of three topologies of multilevel inverters applied to drive an induction motor of 500 kVA/4.16 kV. The multilevel inverters analyzed are: a neutral point clamped inverter, a symmetrical cascaded multilevel inverter and a hybrid asymmetrical cascaded multilevel inverter. The performance indexes used in the comparison are total harmonic distortion, first order distortion factor, semiconductors power losses distribution and heat-sink volume. The comparison is developed with the purpose of finding the efficiency and the heat-sink volume where the three systems present the same output filter. ©2008 IEEE.

LIQUID-PHASE MICROEXTRACTION FOR SIMULTANEOUS CHROMATOGRAPHIC ANALYSIS OF THREE ANTIDEPRESSANT DRUGS IN PLASMA

A method using Liquid Phase Microextraction for simultaneous detection of citalopram (CIT), paroxetine (PAR) and fluoxetine (FLU), using venlafaxine as internal standard, in plasma by high performance liquid chromatography with fluorescence detection was developed. The linearity was evaluated between 5.0 and 500 ng mL(-1) (r > 0.99) and the limit of quantification was 2.0, 3.0 and 5.0 ng mL-1 for CIT. PAR and FLU, respectively. Therefore, it can be applied to therapeutic drug monitoring, pharmacokinetics or bioavailability studies and its advantages are that it necessary relatively inexpensive equipment and sample preparation techniques.

Liquid-phase microextraction for simultaneous chromatographic analysis of three antidepressant drugs in plasma

A method using Liquid Phase Microextraction for simultaneous detection of citalopram (CIT), paroxetine (PAR) and fluoxetine (FLU), using venlafaxine as internal standard, in plasma by high performance liquid chromatography with fluorescence detection was developed. The linearity was evaluated between 5.0 and 500 ng mL-1 (r > 0.99) and the limit of quantification was 2.0, 3.0 and 5.0 ng mL-1 for CIT, PAR and FLU, respectively. Therefore, it can be applied to therapeutic drug monitoring, pharmacokinetics or bioavailability studies and its advantages are that it necessary relatively inexpensive equipment and sample preparation techniques.