Application of a generalized difference expansion based reversible audio data hiding algorithm

Multimedia Tools and Applications - In this paper, a generalized difference expansion based reversible audio data hiding algorithm is proposed and a recommended application is introduced. The...     

A single parameter to evaluate stress state in rail head for rolling contact fatigue analysis

Based on the Smith‐Watson‐Topper (SWT) method, a phenomenological approach for multiaxial fatigue analysis, the maximum SWT parameter is proposed as a single parameter to evaluate the stress state in the rail head for assessing the fatigue integrity of the structure. A numerical procedure to calculate the maximum SWT parameter from a finite element analysis is presented and applied in a case study, where the stress and strain fields due to wheel/rail rolling contact are obtained from a three‐dimensional finite element simulation with the steady‐state transport analysis technique. The capability of the SWT method to predict fatigue crack initiation in the rail head is confirmed in the case study. Analogous to von Mises stress for strength analysis, the maximum SWT parameter can be applied to evaluate the fatigue loading state not only in rail head due to rolling contact fatigue but also in a generic structure subjected to a cyclic loading.     

New fully-differential amplifier-less pipelined ADC with wide power scalability and ERBW

A 24 GHz power amplifier for direct-conversion transceiver using standard 0.18 μm CMOS technology is reported. The three-stage power amplifier comprises two cascaded cascode stages for high power gain, followed by a common-source stage for high power linearity. To increase the saturated output power (P_sat) and power-added efficiency (PAE), the output stage adopts a Wilkinson-power-divider- and combiner-based two-way power dividing and combining architecture. The power amplifier consumes 163.8 mW and achieves power gain (S₂₁) of 22.8 dB at 24 GHz. The corresponding 3-dB bandwidth of S₂₁ is 4.2 GHz, from 22.7 to 26.9 GHz. At 24 GHz, the power amplifier achieves P_sat of 15.9 dBm and maximum PAE of 14.6 %, an excellent result for a 24 GHz CMOS power amplifier. In addition, the measured output 1-dB compression point (OP_1dB) is 7 dBm at 24 GHz. These results demonstrate the proposed power amplifier architecture is very promising for 24 GHz short-range communication system applications.     

Mucoadhesive chitosan/OA nanoparticles charged with celecoxib inhibit prostaglandin E2 LPS‐induced in U937 cell line

The present study shows the potential of new carriers of celecocib (CEL) for prostaglandin E2 (PGE2) inhibition in U937 cell line. Self‐assembled nanoparticles based on oleic acid‐modified chitosan were covered with hyaluronic acid (HA) obtaining systems with spherical shape and particle size close to 300 nm. CEL was encapsulated and the encapsulation efficiency (%EE) was dependent of the drug solubility in acid media, reaching %EE of 75.5% and 58.2% to strong and weak acid, respectively. The covering with HA increased the mucoadhesive properties and, the cellular binding and cellular uptake in U937 cells. Nanoparticles prepared in strong acid presented zeta potential (ζ) of 43.8 ± 0.4 mV, which become toxic and stimulate the PGE2 production in U937 cells, at the concentration 1 mg/mL. However, nanoparticles prepared in weaker acid presented ζ of 36.5 ± 1.21 mV, showing nontoxic effect and inhibitory effect of PGE2 from 80.8 pg/mL until 43.4 pg/mL. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45288.     

Natural weathering studies of biobased thermoplastic starch from agricultural waste/polypropylene blends

Thermoplastic starch (TPS) obtained from agricultural waste was blended with polypropylene (PP) for natural weathering studies. The agricultural waste material was obtained from seeds and tubers with a starch content of approximately 50%. Commercial‐grade TPS and native tapioca‐based TPS were also prepared for comparison. The biobased TPS/PP extruded sheets were exposed to natural weathering for six months and their deterioration in weight, tensile properties, thermal properties, and relative molecular weight were monitored. SEM micrographs revealed the formation of surface cracking and the presence of microorganisms. FTIR spectrum indicated an increase in the carbonyl index over time as a result of the formation of degradation products. TPS/PP blends made from agricultural waste showed a better resistance to natural weathering compared to the other high starch formulation. The higher starch content in the blend system encouraged the rapid degradation process due to the combined effect of UV radiation with oxidation, moisture, temperature, and microbial attack. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Degradation studies during water absorption,aerobic biodegradation,and soil burial of biobased thermoplastic starch from agricultural waste/polypropylene blends

Thermoplastic starch (TPS) from agricultural waste consisting of different amylose/amylopectin ratios was blended with polypropylene (PP) for degradation studies. The agricultural waste material was obtained from seeds and tubers with low starch contents of ～50%. Non‐Fickian behavior was observed for the water absorption test, and water uptake increased with increases in amylopectin content. The biodegradation was assessed based on the extent of carbon conversion, and was found to be dependent on the water absorption behavior and molecular structure of the starch component. Outdoor soil burial showed greater weight loss and deterioration in tensile properties compared to indoor soil burial. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Analysis of the behaviours of phase and amplitude mismatch compensators to achieve 82.5 dB image rejection ratio

This article presents an experiment to analyse the behaviour of phase and amplitude mismatch compensators in quadrature receivers. The experiment shows that the input signal level and convergence time affect image rejection ratio (IRR) and signal to noise and distortion ration (SNDR). Based on the findings, design guidelines are suggested and an exceptionally high 82.5 dB IRR is demonstrated in a digital low intermediate frequency (low-IF) Weaver receiver constructed using off-the-shelf components, whereas existing mismatch compensation techniques can only achieve 50 to 65 dB IRR.     

Development of a Rapid Fluorescent Diagnostic System for Early Detection of the Highly Pathogenic Avian Influenza H5 Clade 2.3.4.4 Viruses in Chicken Stool

Rapid diagnosis is essential for the control and prevention of H5 highly pathogenic avian influenza viruses (HPAIVs). However, highly sensitive and rapid diagnostic systems have shown limited performance due to specific antibody scarcity. In this study, two novel specific monoclonal antibodies (mAbs) for clade 2.3.4.4 H5Nx viruses were developed by using an immunogen from a reversed genetic influenza virus (RGV). These mAbs were combined with fluorescence europium nanoparticles and an optimized lysis buffer, which were further used for developing a fluorescent immunochromatographic rapid strip test (FICT) for early detection of H5Nx influenza viruses on chicken stool samples. The result indicates that the limit of detection (LoD) of the developed FICT was 40 HAU/mL for detection of HPAIV H5 clade 2.3.4.4b in spiked chicken stool samples, which corresponded to 4.78 × 10⁴ RNA copies as obtained from real-time polymerase chain reaction (RT-PCR). An experimental challenge of chicken with H5N6 HPAIV is lethal for chicken three days post-infection (DPI). Interestingly, our FICT could detect H5N6 in stool samples at 2 DPI earlier, with 100% relative sensitivity in comparison with RT-PCR, and it showed 50% higher sensitivity than the traditional colloidal gold-based rapid diagnostic test using the same mAbs pair. In conclusion, our rapid diagnostic method can be utilized for the early detection of H5Nx 2.3.4.4 HPAIVs in avian fecal samples from poultry farms or for influenza surveillance in wild migratory birds.     

Fano Multiple-Symbol Differential Detectors for Differential Unitary Space–Time Modulation

We present a class of suboptimal multiple-symbol differential detectors (MSDDs) for differential unitary space-time (ST) codes in a time-selective Rayleigh flat-fading channel. These noncoherent detectors, termed Fano ST-MSDDs, employ the well-known Fano algorithm as their decoding engines. Their bit-error rate (BER) performance is excellent, as there is no irreducible error floor, even at very high fade rates. Compared with the sphere decoder, which is optimal, our best detector, termed an on-demand bi-Fano ST-MSDD, suffers only a 0.3 dB degradation in power efficiency. However, its computational complexity, as a function of the signal-to-noise ratio (SNR), is consistently lower than that of the sphere decoder and does not experience the exponential growth in complexity in the latter when the SNR decreases. It can thus be concluded that the Fano algorithm is a powerful detection strategy for differential ST codes in fading channels. Our main contribution is in making the modifications and improvements to the Fano algorithm that enables this realization. The innovations include the bi-Fano, edge-bi-Fano, and on-demand bi-Fano search strategies, as well as a new dynamic threshold adjustment scheme for avoiding unnecessary back-and-forth node evaluations during backtracking     

Diffusion Characteristics of Zr4+ in LiNbO3 Single‐Crystal

Diffusion characteristics of Zr⁴⁺ in LiNbO₃ single‐crystal were studied. Zr⁴⁺‐doped LiNbO₃ crystal plates were prepared by in‐diffusion of 100 nm thick ZrO₂ film coated onto Z‐cut congruent substrates in wet O₂ at different temperatures. Zr⁴⁺‐diffused profile was analyzed by secondary ion mass spectrometry. The results show that the Zr⁴⁺ diffusion follows the traditional diffusion theory. From the measured profiles, important diffusion parameters are obtained, such as diffusivity and its temperature dependence, diffusion constant, activation energy, surface concentration, and solubility. The Zr⁴⁺ has a diffusivity similar to that of Ti⁴⁺, implying that the Zr⁴⁺ doping and the Ti⁴⁺ diffusion can be performed simultaneously to simplify the fabrication process of a photorefractive‐damage‐resistant Zr⁴⁺‐doped Ti‐diffused LiNbO₃ waveguide.