FUZZY RADIAL BASIS FUNCTION (FRBF) NETWORK BASED TOOL CONDITION MONITORING SYSTEM USING VIBRATION SIGNALS

Thriving automation in industries leads to more research on the tool condition monitoring systems for better accuracy and fast recognition/evaluation of tool wear. Research on the applicability of the new advances in the soft-computing as well as in the signal processing fields is the inevitable consequence. In this work, a new soft-computing modeling technique, fuzzy radial basis function (FRBF) network has been applied to the prediction of drill wear using the vibration signal features. This work presents the wear prediction performance comparison of this new model with three other already tried and established soft-computing models, such as back propagation neural network (BPNN), radial basis function network (RBF) and normalized radial basis function network (NRBF), for both time-domain as well as wavelet packet approaches of feature extraction. Experimental results show that FRBF model with wavelet packet approach produces the best performance of predicting flank wear.     

Alginate‐gelatin blend with embedded voids for controlled release applications

Alginate gel is known for its potential use in the controlled release of drugs, and as a 3‐D structure for tissue harvesting. In this paper, the tuning of the performance of alginate gel by blending gelatin in the aqueous phase, and introducing bubbles in a regular alignment are discussed. Monodisperse bubbles in millimetre or submillimeter size were introduced into the aqueous suspension of the blend prior to gelation, using a novel fluidic arrangement. The CaCl₂ solution, added as the crosslinker diffused into the lamella, forming a rigid structure of calcium alginate. The effective blending of gelatin in alginate provided benefits of both the biopolymers in the final product. The benefits are the excellent absorption capacity of alginate and the mechanical strength of gelatin in the blend. The self‐aligned voids enabled further tuning of absorption capacity and/or rate of release. Also, the presence of voids enhanced the elastomeric quality of the composite structure. The uptake of Vitamin B₁₂ solution was measured gravimetrically, and the release in PBS buffer on a shaker was studied using UV‐vis spectrophotometer. For different loadings of void and gelatin, the absorption capacity, mechanical strength and the compression behavior were analysed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44787.     

Design,fabrication and characterization of silk fibroin-HPMC-PEG blended films as vehicle for transmucosal delivery

This study illustrates the fabrication of stable mucoadhesive films of silk protein fibroin as potential vehicle for transmucosal delivery by blending fibroin with hydroxy propyl methyl cellulose (HPMC) and poly ethylene glycol 400 (PEG). Investigations on mechanical properties, swelling ability in simulated saliva, bioadhesive strength by a specially designed instrument and study of in vitro stability in simulated saliva of goat buccal mucosa as model membrane was undertaken. Molecular interaction between blended materials was evaluated by FTIR spectroscopy. Increase in fibroin content of the blended films not only increased the mechanical properties and water stability but also the degree of swelling and stability of the films in simulated saliva. The FTIR spectrum shows an increase in water stability of the fibroin-HPMC blended films due to the formation of intermolecular hydrogen bonding between the HPMC and fibroin. The conformational transition of the silk fibroin molecule from the amorphous and random coil to β sheet structure has been observed. Fibroin-HPMC-PEG blended films can be used as a vehicle for transmucosal delivery by virtue of its good mechanical strength, water stability, ex vivo bioadhesive strength and ideal swellability as such characteristics are essential for rapid mucoadhesion.     

Effect of Arching on Active Earth Pressure for Rigid Retaining Walls Considering Translation Mode

It has been established by the researchers that owing to the arching effect, the active earth pressure distribution on a horizontally translating rigid wall is not triangular but nonlinear. This is attributed to the arching behavior exhibited by soil. Also, the shape of the failure surface plays a critical role in determining the magnitude of lateral stresses and the height at which the resultant active earth force is centered from the base of the wall. In the present study, various combinations of shapes of critical failure surface and arch shapes were studied to estimate the coefficient of active earth pressure on the rigid retaining wall in cohesionless soil. The results were compared with field results and those predicted by other theories. A critical review has been made based on the comparison of results obtained from the present analyses with experimental observations. Design charts for modified active earth pressure coefficient and height of application of lateral force have also been suggested.     

An interference cancellation scheme for D2D multi-link communication underlaying cellular network

Device-to-device (D2D) communication has attracted much attention in the field of mobile networks for local area connectivity due to its spectral efficiency, high bit rate support and low power consumption. A group of D2D capable devices, called a cluster, can be connected through multiple links by sharing common resources. This may however result in co-channel interference between them. In this paper, we propose a novel orthogonal precoding vector selection method for reducing co-channel interference and thus maximizing the achievable data rate for each device in the cluster. The proposed method can be employed for uplink and downlink transmissions of both cellular and D2D communications. The analysis of the proposed method is carried out for the case where the cellular channel resource is being shared by single and multiple D2D links. Initially, the results via simulations are compared with the theoretical analysis and the performance of the proposed method is evaluated and compared for different resource sharing modes. The results show that our proposed method enhance the system throughput when compared with the conventional precoding vector allocation method. Finally, the paper illustrates that the introduction of cluster head in a cluster can save battery life of devices.     

Immunostimulatory CpG oligonucleotides form defined three-dimensional structures: results from an NMR study

The DNA eicosamer 5'-TCCATGACGTTCCTGATGCT-3' is known to stimulate the innate immune system of vertebrae. The immunostimulatory activity is based on the activation of Toll-like receptor 9 (TLR9). While it is known that the CG dinucleotide of the eicosamer has to be unmethylated, the structural basis of the recognition of the DNA through the receptor remains unclear. Oligodeoxynucleotides containing the sequence of the eicosamer, or a portion thereof, ranging in length from hexamer to pentaeicosamer were studied by (1)H NMR spectroscopy. Based on two-dimensional NMR spectra, a number of resonances could be unambiguously assigned. For all oligonucleotides, structural transitions were detected upon heating, as monitored by the line width and chemical shift of low-field resonances. This includes the TC dinucleotide of the 5'-terminal portion, which does not have any clear base-pairing partners. The melting transitions, together with the NOESY cross-peaks, demonstrate that structure formation occurs well beyond the core hexamer 5'-GACGTT-3', a fact that may be important for understanding the molecular recognition by the Toll-like receptors of the innate immune system.     

Dielectric and impedance spectroscopy studies on sisal fibre-reinforced polyester composite

Frequency and temperature dependence of dielectric constant (ε_r), dielectric loss (tanδ), ac conductivity (σ_ac) and complex impedance spectroscopy studies on cured polyester matrix and sisal fibre-reinforced polyester composites (SFRPC) have been investigated in the frequency range from 180 Hz to 1 MHz and temperature range from room temperature to 200 °C. The experimental results showed that with the incorporation of sisal fibre, the values of ε_r, tanδ and σ_ac are increased. It is also found that the values of ε_r and tanδ for both cured polyester matrix and SFRPC are decreased with increasing frequency, which indicates that the major contribution to the polarization may come from orientation polarization and interfacial polarization. The increasing value of ε_r with increasing temperature at a particular frequency is due to free motion of the dipole molecular chains within the cured polyester matrix and SFRPC at higher temperature.     

High-surface step density on dendritic pd leads to exceptional catalytic activity for formic acid oxidation

Dendritic Pd with corrugated surfaces, obtained by a novel AC technique, exhibits an exceptionally high catalytic activity for the oxidation of formic acid because of the presence of a high density of surface steps. The formation of twinned dendrites leads to a predominance of exposed 111 facets with a high density of surface steps as evident from high resolution electron microscopy investigations. These surface sites provide active sites for the adsorption of the formic acid molecules, thereby enhancing the reaction rate. Control experiments by varying the time of deposition reveal the formation of partially grown dendrites at shorter times indicating that the dendrites were formed by growth rather than particle attachment. Our deposition method opens up interesting possibilities to produce anisotropic nanostructures with corrugated surfaces by exploiting the perturbations involved in the growth process.