Interfacial tensions of oil,water, chemical dispersant systems

Oil-water interfacial tension measurements are reported for systems of crude oils, distilled and salt water, and chemical dispersants, using the spinning drop technique. By varying the amount of dispersant and the volumetric ratio of water to oil it is possible to deduce an effective oil-water partition coefficient for the interfacial tension reducing species and to suggest a relationship between the extent of interfacial tension reduction and dispersant concentration. The implications of the results in assessing the mechanism and effectiveness of the chemical dispersion process are discussed.     

Measurements of cavity ringdown spectroscopy of acetone in the ultraviolet and near-infrared spectral regions: potential for development of a breath analyzer

We report a study on the cavity ringdown spectroscopy of acetone in both the ultraviolet (UV) and the near-infrared (NIR) spectral regions to explore the potential for development of a breath analyzer for disease diagnostics. The ringdown spectrum of acetone in the UV (282.4-285.0 nm) region is recorded and the spectrum is in good agreement with those obtained by other spectral techniques reported in the literature. The absorption cross-section of the C-H stretching overtone of acetone in the NIR (1632.7-1672.2 nm) is reported for the first time and the maximum absorption cross-section located at 1666.7 nm is 1.2 x 10(-21) cm(2). A novel, compact, atmospheric cavity with a cavity length of 10 cm has been constructed and implemented to investigate the technical feasibility of the potential instrument size, optical configuration, and detection sensitivity. The detection limit of such a mini cavity employing ringdown mirrors of reflectivity of 99.85% at 266 nm, where acetone has the strongest absorption, is approximately 1.5 ppmv based on the standard 3 criteria. No real breath gas samples are used in the present study. Discussions on the detection sensitivity and background spectral interferences for the instrument development are presented. This study demonstrates the potential of developing a portable, sensitive breath analyzer for medical applications using the cavity ringdown spectral technique.     

Analysis of antiresonant reflecting optical waveguide gratings by use of the method of lines

The modal spectral response of an antiresonant reflecting optical waveguide (ARROW) with periodic corrugations or grating is calculated for both shallow and deep gratings with the Method of Lines. The effect of the ARROW layer thickness and the grating depth on the spectral response is studied. It is found that when the ARROW-layer thickness is close to resonance, the ripples in the reflection spectra become smooth and the peak reflectivity drops. This is attributed to the large increase in the leakage loss of the ARROW waveguide near resonance. The ARROW grating is characterized by modal reflectivity spectra, which exhibit a strong polarization discrimination property, in favor of the TE polarization.     

Preparation of New Fibers on the Basis of Codeine Imprinted Polymer

A monolithic copolymer of methacrylic acid-ethylene glycol dimathacrylate as a fiber with 2 cm length and 0.3 mm diameter, containing codeine (CO) template was prepared through thermal radical co-polymerization procedure. This fiber is a robust recognition material capable of mimicking natural systems, combined with solid-phase micro-extraction (SPME) and gas chromatography/mass spectrometry for the extraction of trace CO from various street-drug samples. Effective experimental parameters such as Methacrylic Acid (MAA), Ethylene glycol dimethacrylate (EDMA), and CO proportions, nature, and dimension of mold, copolymerization time and temperature were optimized. Experimental studies such as scanning electron microscopy (SEM) reveal that highly homogenate fiber was achieved that can preciously be used for the above mentioned goals.     

Numerical Simulation of the FDTD Method in LabVIEW [Application Notes]

LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is a National Instruments program development. In this article, we present an FDTD code developed in Lab VIEW for basic scattering modeling. 1-D formulation with simple radiating boundary condition followed by a 2-D formulation is presented. The implementation of the PML boundary condition has been used to truncate the 2-D model used for the simulation to avoid reflections from the edges of the modeling grid. This particular formulation allows one to terminate any given material directly in the PML layers without virtually any reflection between the region of interest and the PML absorbing boundaries. The formulation uses the electric field E, the magnetic field H, and the electric displacement D rather than only the electric and magnetic fields as in usual FDTD implementation. This formulation has the advantage of making the PML properties completely independent of the background medium.     

Texture databases – A comprehensive survey

Texture analysis is a very important area in the field of computer vision and related fields. There are a good number of databases developed by different research groups for various texture analysis, in the field of medical analysis, robotics, recognition, analysis, image processing, etc. However, till-to-date, there is no comprehensive works covering the important databases and analyze these in various perspectives. In this paper, we consider this important task so that it becomes helpful for a researcher to choose and evaluate having crucial evaluating aspects in mind. We categorize and critically survey based on many references of the state-of-the-art related to the databases and other texture works. We strongly believe that this elegant survey will be a great contribution for the vision community, especially in the arena of texture analysis.     

FUZZY REPLACEMENT ALGORITHM FOR CACHE MEMORY

This paper reports a replacement procedure for cache memories. The procedure is essentially a fuzzy algorithm that makes use of 18 rules to select the cache block to be replaced. These rules are primarily a function of three parameters: age and the frequency of usage of a cache block, and the global hit ratio of the cache system. Computationally, the proposed algorithm calculates a replacement index for each cache block and the block with highest replacement index is selected as a victim. The performance of this fuzzy procedure is compared with traditional replacement algorithms such as least recently used (LRU) and first in First out (FIFO). Our simulation experiments indicate that the proposed algorithm is a strong contender to the traditional counterparts. The unique feature of the proposed algorithm is its flexibility; that is, one can always improve its performance further by fine-tuning the rules.     

A new image binarization method using iterative partitioning

This paper proposes a new method for image binarization that uses an iterative partitioning approach. The proposed method has been tested towards binarization of both document and graphic images. The quantitative comparisons with other standard methods reveal that the proposed approach outperforms existing widely used binarization techniques in terms of accuracy of binarization. The experimental results further establish the superiority of the proposed method, especially for degraded documents and graphic images. The proposed algorithm is suitable for a multi-core processing environment as it can be split into multiple parallel units of executions after the initial partitioning.     

Intelligent facial emotion recognition and semantic-based topic detection for a humanoid robot

Automatic perception of human affective behaviour from facial expressions and recognition of intentions and social goals from dialogue contexts would greatly enhance natural human robot interaction. This research concentrates on intelligent neural network based facial emotion recognition and Latent Semantic Analysis based topic detection for a humanoid robot. The work has first of all incorporated Facial Action Coding System describing physical cues and anatomical knowledge of facial behaviour for the detection of neutral and six basic emotions from real-time posed facial expressions. Feedforward neural networks (NN) are used to respectively implement both upper and lower facial Action Units (AU) analysers to recognise six upper and 11 lower facial actions including Inner and Outer Brow Raiser, Lid Tightener, Lip Corner Puller, Upper Lip Raiser, Nose Wrinkler, Mouth Stretch etc. An artificial neural network based facial emotion recogniser is subsequently used to accept the derived 17 Action Units as inputs to decode neutral and six basic emotions from facial expressions. Moreover, in order to advise the robot to make appropriate responses based on the detected affective facial behaviours, Latent Semantic Analysis is used to focus on underlying semantic structures of the data and go beyond linguistic restrictions to identify topics embedded in the users’ conversations. The overall development is integrated with a modern humanoid robot platform under its Linux C++ SDKs. The work presented here shows great potential in developing personalised intelligent agents/robots with emotion and social intelligence.     

Addendum to ‘(Singular) state models and (singular) LTID systems’

In this note, a construction of state representations of singular linear time-invariant differential systems is described directly in terms of trajectories.