Physical,optical, and electrical properties of a new conducting polymer

This work studies the electrical and optical properties of the conducting polymer composite films of polypyrrole–chitosan (PPy–CHI). The surface plasmon resonance (SPR) technique was used to study the optical properties of PPy and PPy–CHI composite films. Then, the values of the real and imaginary parts of the refractive indexes of PPy and PPy–CHI films were obtained by nonlinear least square fitting using Fresnel equations for a three-layer system of SPR system. The electrical conductivity measurements showed that the conductivity of the electrochemical prepared films improved in the presence of CHI and can be controlled by varying the CHI amount in the composite. The thermal diffusivity of the PPy–CHI composite films was measured by open photoacoustic spectroscopy and it has been shown that the thermal diffusivity is related to the electron migration in the conjugation chain length. The increase in electromagnetic interference shielding effectiveness (EMI SE) with the increase in electrical conductivity of the films is mostly from shielding by reflection rather than absorption.     

Adaptive strategy changes as a function of task demands: a study of car drivers

When drivers perform additional tasks while driving, research shows conflicting results: primary driving performance may deteriorate but adaptive changes such as reducing driving speed have also been noted. We hypothesized that the nature of the secondary task may be important: drivers may give more priority to tasks that serve goals of the driving task itself, for example route finding, than tasks not directly relevant for driving, for example tuning the radio. The main objective of the present driving simulator study was to test this hypothesis. Twenty subjects performed two different subsidiary tasks while driving through two levels of traffic density: a working memory (WM) task and a map reading (MAP) task. It was hypothesized that in high task demand situations, the WM task, irrelevant for the driving task, would be neglected more than the MAP task. The results confirmed the hypothesis: in MAP conditions, the WM task was indeed neglected, but map reading resulted in more swerving, indicating that the subjects looked at the map despite the high task demands. It is concluded that drivers will be highly motivated to get route information, and RG systems should therefore present their information in a readily understandable format.     

Growth of platinum nanoparticles on stainless steel 316L current collectors to improve carbon-based supercapacitor performance

In this study, an improvement in the supercapacitive behavior of a symmetrical carbon-based supercapacitor is achieved by modifying the stainless steel current collector using platinum nanoparticles (PtNs). The PtNs are allowed to grow on the surface of the current collectors before they make contact with the surface of activated carbon electrode monoliths prepared from pre-carbonized rubber wood sawdust. All of the methods used in the present study, i.e., electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge–discharge tests provide consistent results, suggesting that the monolithic form of carbon electrodes and PtNs play a significant role in reducing the equivalent series resistance from 337 to 18 mΩ and to increase the specific capacitance from 108 to 151 F g⁻¹. This change improves the specific energy from 2.5 to 3.3 Wh kg⁻¹ and the specific power from 275 to 288 W kg⁻¹, respectively.     

Towards adaptive structured Dirichlet smoothing model for digital resource objects

Multimedia Tools and Applications - Digital resource objects (DRO) are among the most valuable resources that store the accumulated knowledge of humankind. Nowadays, many organisations aim to make...     

Mechanochemical solid state synthesis and optical properties of Cd0.5Zn0.5Se nanocrystals

High-quality Cd_0.5Zn_0.5Se nanoparticles with diameters ranging from 2.6 to 4.3 nm were synthesized via intensive mechanical milling for up to 20 h. The full width at half maximum (FWHM) and broadening of the diffraction peaks increased with increasing ball milling process and later decreased. XRD pattern confirmed a dominant zinc blende phase at (x = 0.5) composition. The optical spectra of the nanoparticles exhibited an onset absorption peak at 349 nm, with maximum absorption at 290 nm. The luminescence properties of the nanoparticles at room temperature were analyzed via photoluminescence spectroscopy, revealing band-edge emission at 354 nm. Photoluminescence (PL) spectra exhibit broad emission band at the range of (380–508) nm photon energy. The PL spectrum has two distinctive shoulders at 403 and 450 nm. Band emissions of 1.74, 1.54 and 1.4 eV at longer wavelengths that were associated with the surface state were also observed. High-transmission electron microscopy (HRTEM) revealed the successful annihilation of such defects with continuous milling.     

Static Bottom-Hole Pressures in Wells

A compote procedure is presented in this article for estimating static pressure gradient. The procedure integrates reservoir properties; temperature, pressure, depth, and density to calculate pressure drop in wellbore. The procedure constraints are intended to ensure that an accurate pressure gradient is obtained.     

Characteristic Drying Curves of Cocoa Beans

The characteristic drying curves of cocoa beans are determined by using a tunnel drier where conditioned air passes a single cocoa berm suspended from an electronic balance in the test section. Weight loss, and temperatures of air, testa and nib of the cocoa bean is monitored on personal computers. The nornmalised drying rate versus the normalised moisture content is regressed by least square method to fit a new polynomial model for the penetration falling rate period and a linear model for the regular regime falling rate period. It can be concluded that there are three drying periods for cocoa beans namely the constant drying rate period, the penetration falling rate period and the regular regime falling rate period. The polynomial model estimates the penetration period quite well whereas the linear model estimates the regular regime quite well as well. There is no observable influence of relative humidity and air temperature on the characteristic drying curve of cocoa beans. However, the air velocity seems to have some influence on the curve.     

The Lrat−/− Rat: CRISPR/Cas9 Construction and Phenotyping of a New Animal Model for Retinitis Pigmentosa

Purpose: We developed and phenotyped a pigmented knockout rat model for lecithin retinol acyltransferase (LRAT) using CRISPR/Cas9. The introduced mutation (c.12delA) is based on a patient group harboring a homologous homozygous frameshift mutation in the LRAT gene (c.12delC), causing a dysfunctional visual (retinoid) cycle. Methods: The introduced mutation was confirmed by DNA and RNA sequencing. The expression of Lrat was determined on both the RNA and protein level in wildtype and knockout animals using RT-PCR and immunohistochemistry. The retinal structure and function, as well as the visual behavior of the Lrat^−/− and control rats, were characterized using scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), electroretinography (ERG) and vision-based behavioral assays. Results: Wildtype animals had high Lrat mRNA expression in multiple tissues, including the eye and liver. In contrast, hardly any expression was detected in Lrat^−/− animals. LRAT protein was abundantly present in wildtype animals and absent in Lrat^−/− animals. Lrat^−/− animals showed progressively reduced ERG potentials compared to wildtype controls from two weeks of age onwards. Vison-based behavioral assays confirmed reduced vision. Structural abnormalities, such as overall retinal thinning, were observed in Lrat^−/− animals. The retinal thickness in knockout rats was decreased to roughly 80% by four months of age. No functional or structural differences were observed between wildtype and heterozygote animals. Conclusions: Our Lrat^−/− rat is a new animal model for retinal dystrophy, especially for the LRAT-subtype of early-onset retinal dystrophies. This model has advantages over the existing mouse models and the RCS rat strain and can be used for translational studies of retinal dystrophies.     

Drying Kinetics of Oil Palm Frond Particles in an Agitated Fluidized Bed Dryer

The drying kinetics of oil palm frond particles in a laboratory-scale agitated fluidized bed dryer were investigated under various operating conditions: inlet air temperature (50–80°C), superficial air velocity (0.6–1.0 m/s), bed load (200–300 g), and agitation speed (300–500 rpm). To study the effects of these variables on the drying time and drying rate, an experimental design using Taguchi orthogonal array was employed. Based on analysis of variance (ANOVA), the results indicated that inlet air temperature greatly affected the drying rate, followed by superficial air velocity and bed load. The effect of agitation speed on the drying rate was found to be small. The experimental drying kinetics data were compared with the values obtained from three different models, namely, the Page model, modified quasi-stationary method (MQSM), and a new composite model. It was found that the proposed new model could satisfactorily predict the complete drying rate curve for the drying of oil palm fronds.