Investigation of the effect of finite-sized ions on the nanowire field-effect transistor in electrolyte concentration using a modified Poisson–Boltzmann model

One-dimensional (1D) nanowire field-effect transistors (FETs) have recently played a major role in sensing applications. Due to charging of the surface functional chemical groups with protonation and deprotonation, the transport properties of these nanowire transistors affect the aqueous environment, altering the electrical double layer (EDL) potential drops and charge distributions in the electrolyte concentration. In this work, we have implemented the simple modified Poisson–Boltzmann (MPB) theory in a 1D silicon nanowire FET, and the effect of the various finite sizes of ions in z:z symmetric electrolyte concentration was investigated. For a given ionic concentration and surface charge, the EDL potential drop, accumulation of charges and the charge distributions of NaCl and CsCl ions were studied. From the MPB model results with the nanowire FET, it was observed that the potential drop of the EDL depends on the size of the ions in the electrolyte. The study of various electrostatic investigations of finite-sized ions was successfully done by implementing the MPB model on a silicon nanowire FET. It can be used in both chemical and biological sensors.     

Nonbonded interactions in membrane active cyclic biopolymers. II. Ion binding by valinomycin

A possible mode for the capture of a cation by the carrier molecule valinomycin has been simulated. The intramolecular nonbonded energy and the binding energy for a centrally located potassium ion at different stages in the capture process have been evaluated using a method proposed earlier. Contrary to intuitive expectations the open conformation of valinomycin is also found to have a strong affinity for K⁺. There appears to be a rather high potential barrier between the open and closed symmetric conformations.     

Weyl multipliers for invariant Sobelev spaces

A concrete characterization for theL ^P -multipliers (1<p<∞) for the Weyl transform is obtained. This is used to study the Weyl multipliers for Laguerre Sobolev spacesW ^m,p (? ⁿ ). A dual space characterization is obtained for the Weyl multiplier classM _W (W _L ^m,1 (? ⁿ )).     

Automatic acoustic synthesis of human-like laughter

A technique to synthesize laughter based on time-domain behavior of real instances of human laughter is presented. In the speech synthesis community, interest in improving the expressive quality of synthetic speech has grown considerably. While the focus has been on the linguistic aspects, such as precise control of speech intonation to achieve desired expressiveness, inclusion of nonlinguistic cues could further enhance the expressive quality of synthetic speech. Laughter is one such cue used for communicating, say, a happy or amusing context. It can be generated in many varieties and qualities: from a short exhalation to a long full-blown episode. Laughter is modeled at two levels, the overall episode level and at the local call level. The first attempts to capture the overall temporal behavior in a parametric model based on the equations that govern the simple harmonic motion of a mass-spring system is presented. By changing a set of easily available parameters, the authors are able to synthesize a variety of laughter. At the call level, the authors relied on a standard linear prediction based analysis-synthesis model. Results of subjective tests to assess the acceptability and naturalness of the synthetic laughter relative to real human laughter samples are presented.     

Electronic excitations of fluoroethylenes

Several lowest-lying singlet electronic states of vinyl fluoride, trans-, cis-, and 1,1-difluoroethylene, trifluoroethylene, and tetrafluoroethylene were investigated by using symmetry-adapted cluster configuration interaction theory. Basis sets up to Dunning's aug-cc-pVTZ augmented with appropriate Rydberg functions were utilized for the calculations. Calculated excitation energies show a good agreement with the available experimental values. Even in the troublesome pi-->pi(*) transitions, the excitation energies obtained in the present study agree well with the experimental values except in one or two fluoroethylenes. Strong mixing between different states was noticed in a few fluoroethylenes; especially the mixing is very strong between pi-pi(*) and pi-3ppi states in trifluoroethylene. No pure pi-sigma(*) excited state was found in almost all the fluoroethylenes. Several assignments and reassignments of features in the experimental spectra were suggested. The present study does not support the existing argument that the interaction between the pi-pi(*) and sigma-sigma(*) states is the reason behind the blueshift of around 1.25 eV in the pi-pi(*) excitation energy of tetrafluoroethylene. Possible reasons, including structural changes, for this shift are discussed in detail. Several low-lying triplet excited states were also studied.     

Riesz transform and Riesz potentials for Dunkl transform

Analogues of Riesz potentials and Riesz transforms are defined and studied for the Dunkl transform associated with a family of weight functions that are invariant under a reflection group. The L^p$L^p$ boundedness of these operators is established in certain cases.     

Optimal Control of Batch MMA Polymerization with Specified Time,Monomer Conversion,and Average Polymer Molecular Weights

Summary: In this paper, the optimal control policies are determined for the free-radical polymerization of methyl methacrylate (MMA) in a non-isothermal batch reactor. The temperature of the fluid inside reactor-jacket is used as the control function to realize four different optimal control objectives. Each objective is formulated to optimize a given variable simultaneously specifying another. The first two objectives target the maximization of monomer conversion in a specified operation time, and the minimization of operation time for a specified, final monomer conversion. The last two objectives target the maximization of monomer conversion for specified, final number- and weight-average polymer molecular weights. The realization of these objectives is expected to be very useful for the batch production of polymers. To meet the specification of an optimization variable other than time, the differential model of batch process is expressed and utilized in the range of specified variable. Equations are provided for Jacobian evaluations to help in the accurate solution of process model. A genetic algorithms-based optimal control method is applied to realize the four optimal control objectives. The results of this application show considerable improvements in the performance of batch MMA polymerization.

     

Induced Smectic X Phase Through Intermolecular Hydrogen-Bonded Liquid Crystals Formed Between Citric Acid and <Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">n</Emphasis>-(Octyloxy)Benzoic Acid

Hydrogen-bonded liquid crystal (HBLC) is synthesized from citric acid (CA) and 4-(octyloxy)benzoic acid (8OBA) with different mole ratios. Fourier transform infrared spectroscopy (FT-IR) confirms the presence of hydrogen bond between CA and 8OBA. Nuclear magnetic resonance (NMR) spectroscopic studies validate the intermolecular complementary, cyclic type of hydrogen bond, and molecular environment in the designed HBLC complex. Powder X-ray diffraction analysis reveals the monoclinic nature of liquid crystal complex in solid phase. Liquid crystal parameters such as phase transition temperature and enthalpy values for the corresponding mesogenic phases are investigated using a polarizing optical microscope (POM) and differential scanning calorimetry (DSC). It is observed that the change in chain length and steric hindrance while increasing the mole ratio in HBLC complex induces a new smectic X (Sm X) along with higher-order smectic G (Sm G) phases by quenching of smectic C (Sm C). From the experimental observations, induced Sm X phase has been identified as a finger print texture. Also, Sm G is a multi-colored mosaic texture in 1:1, 1:2, and 1:3 mol ratios. The optical tilt angle, thermal stability factor, and enhanced thermal span width of CA + 8OBA complex are discussed.     

Biomaterials for molecular electronics development of optical biosensor for retinol

Molecular electronics involves expertise from several branches of science. Various biomaterials and electronics are involved in the fabrication of such devices. While passive biomaterials are involved in anchoring the active biomolecules, the latter are involved in switching and/or signal transduction. In the present investigation we have used a glass-capillary-based approach to design a biosensor for retinol. The sensing element is retinol-binding protein (RBP). The affinity of retinoic-acid-horseradish peroxidase (conjugate) to RBP is tested using a surface plasmon resonance technique. A simple photomultiplier-tube-based system is exploited to monitor the chemiluminescent signal generated upon reaction of hydrogen peroxide and luminol with the conjugate bound to RBP. The photomultiplier tube is directly coupled to a computer for data logging.