L-Ornithine Monohydrochloride Doped Zinc Tris-Thiourea Sulphate Single Crystals for NLO Applications

Silicon - In the current study, transparent and bulk sized L-ornithine monohydrochloride (LOMHC) added zinc tris-thiourea sulphate (LOMHC-ZTS) single crystals are synthesized successfully by...     

A Multi-band Multi-slot MIMO Antenna with Enhanced Isolation

Communication fields are growing rapidly in the recent era, so transmitting the multimedia contents through an open channel becomes a challenging task. The multimedia contents that are transmitted through this channel are highly prone to vulnerabilities and attacks. Therefore, secure and efficient data communication is considered as a major concern in the multimedia communication systems. So, major efforts are taken by researchers to safeguard the originality of each image. In a conventional system, the secure image communication process was achieved by compressing the content first, and then encryption is performed over the compressed data. Even though it met the required security and compression ratio, but some applications may require the reverse system. In this method, the encryption process is conducted prior to compression to improve the privacy of user data. Moreover, the initial concentration is given for improving content privacy rather than concentrating on size reduction. This paper proposes a reversed system that uses block based perceptual encryption algorithm for encryption and vector quantization (VQ) with hybrid Lloyd–Buzo–Gray (LBG)-Adaptive Deer Hunting Optimization (ADHO) algorithm (VQ-LBG-ADHO) for compression. So, the content secrecy gets improved. The involvement of this adaptive optimization method enhances the performance of VQ in the compression process. This method highly concentrates on secure communication, so the reverse process is followed in this method. It not only improves the image secrecy, however, it further enhances the image quality. The performance of this secure communication process is compared with state-of-the-art algorithms, and the results reveal that the proposed method outperforms the other existing methods.

     

A scalable and energy‐efficient MAC protocol for sensor and actor networks

A scalable energy‐efficient MAC protocol is proposed for wireless sensor and actor networks (WSAN) to improve the network performance. Actor's placement has computed using midpoint K‐mean technique. These actors perform as the cluster heads and collect the information from its members. Cluster head computes the shortest path to all of its cluster members. Further, it divides the cluster into multiple subtrees and assigns a noninterference channel to every subtree. A token is assigned to each subtree for intracluster communication. Token handling and token processing mechanisms are proposed to transfer token from one node to next eligible node. Finally, a throughput‐based channel selection mechanism has proposed for actor‐actor communication. The proposed protocol is simulated in NS2 and compared with its competitive MAC protocols. The results describe that the existing protocols are out beaten by the proposed mechanism.     

IP Traffic Modelling in Scalable Drone Network for Carrying Scalable Logistic Operations

Wireless Personal Communications - This study presents a self modelling method for control system of multi-coupled non-linear scalable drones based logistic services with the help of second-order...     

Construction of novel PTh-BiOBr composite with enhanced photocatalytic degradation of Bisphenol A

The high recombination rates of photogenerated electron-holes significant inhibit the catalytic activity of semiconductor photocatalysts. In this study, novel polythiophene (PTh)/BiOBr hybrids were successfully synthesized using an effortless method to achieve the degradation of Bisphenol A (BPA). According to the results, the introduction of polythiophene (PTh) significantly improved the separation efficiency of photocharge carriers, thus enhancing the photocatalytic activity of PTh-BiOBr. The X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectrometer were applied to characterize the samples structure and light absorption properties. The degradation properties of BPA of materials under visible light prove that the photocatalytic capabilities of the complex can be improved significantly compared to BiOBr monomers, thus confirming the above-mentioned hypothesis. Under the same experimental conditions, 0.5% PTh-BiOBr was obtained for the optimal compound, and the degradation efficiency of BPA after 100 min of visible light was 83%, which is 34% higher than that of the BiOBr monomer. In the process of photocatalytic degradation of BPA by the catalyst, the active free radicals of the catalyst were obtained by ESR and free radical capture experiment, while a possible photocatalytic degradation mechanism was proposed on this basis. From O₂, the ?O₂^– plays a major role in the process of photo-react degradation of BPA, while h⁺ and ?OH play a part. This work provides a more eco-friendly and efficient way for BiOBr retouching.     

IAMMAC: an interference‐aware multichannel MAC protocol for wireless sensor–actor networks

In this paper, we discuss an interference aware multichannel MAC (IAMMAC) protocol assign channels for communication in wireless sensor‐actor networks. An actor acts as a cluster head for k‐hop sensors and computes the shortest path for all the sensors. Then, the actor partitions the cluster into multiple subtrees and assigns a noninterference channel to each subtree. The actor 1‐hop sensors are represented as relay nodes. The actor selects a relay node as a backup cluster head (BCH) based on the residual energy and node degree. After selecting a BCH from the relay nodes, the actor broadcast this information to the remaining relay nodes using the common control channel. The relay sensors use the same channel of BCH to communicate with it. However, the other cluster members do not change their data channel. Further, interference‐aware and throughput‐aware multichannel MAC protocol is also proposed for actor–actor coordination. The performance of the proposed IAMMAC protocol is analyzed using standard network parameters such as packet delivery ratio, goodput, end‐to‐end delay, and energy dissipation in the network. The obtained simulation results indicate that the IAMMAC protocol has superior performance as compared with the existing MAC protocols. Copyright © 2015 John Wiley & Sons, Ltd.     

Cure kinetics of multifunctional epoxies with 2,2′‐dichloro‐4,4′‐diaminodiphenylmethane as hardener

The curing behavior of the epoxy resin N,N,N′,N′‐tetraglycidyldiaminodiphenyl methane (TGDDM) with triglycidyl p‐aminophenol as a reactive diluent was investigated using 2,2′‐dichloro‐4,4′‐diaminodiphenylmethane (DCDDM) as the curing agent. The effect of the curing agent on the kinetics of curing, shelf‐life, and thermal stability in comparison with a TGDDM‐diaminodiphenylsulfone (DDS) system was studied. The results showed a lesser activation energy at the lower level of conversion with a broader cure exotherm for the epoxy‐DCDDM system in comparison with the epoxy‐DDS system, although the overall activation energy for the two systems was comparable. TGA studies showed more stability in the epoxy‐DCDDM system than in the epoxy‐DDS system. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2097–2103, 2000     

Structure-based dynamic characteristics of planar linkages including platform-type robots

A comparative study of kinematic chains and their inversions at the conceptual stage of design is expected to help the designer in selecting the best possible chain and inversion for the specified task. To accomplish this, the designer should be able to read the characteristics of the chains based on their topology. It is only necessary to associate logically certain characteristics, weaknesses, and strengths of a chain to perform a task with the structure of the chain and then generalize. Based on this belief, work has been reported earlier to assess the ability of a chain to reveal some of the characteristics, such as structural error, performance, static, and kinematic behavior. In this study, an effort was made to model a chain as a system of dynamically equivalent lumped masses, interconnected, and then, through energy considerations, show that the distance between ground link and joint masses can be taken as the criterion to compare the chains from the viewpoint of balancing and their expected dynamic behavior. The concepts developed are applied to planar in-parallel robots, which are gaining in importance. © 1997 John Wiley & Sons, Inc.     

Transformation of Engineering Education in India Through Student Centric Learning Approach

Wireless Personal Communications - Various research groups are working on the automated detection of epileptic seizures using Electroencephalogram (EEG) data. EEG waveforms are composed of distinct...