Effect of non-uniform inlet velocity profile in the entrance region of a Bingham plastic flow Between parallel plates

In many practical situations the velocity profiles at the channel inlet are asymmetric and give rise to asymmetric developing velocity profiles. This may occur, for example, in the flow near the mouths of pipes in certain types of heat exchangers in which usually the velocity profile has a velocity gradient in the direction normal to the flow. A numerical analysis is carried out to describe the effects of asymmetric velocity profile at the channel inlet on the flow characteristics of a Bingham plastic between parallel plates. Considering the inlet velocity to include a constant transverse velocity gradient with respect to the channel centerline, the pressure drop, the velocity distribution and heat transfer variations along the channel are determined. It has been found that a significant asymmetry occurring near the entrance region is gradually reduced as the flow develops and a completely symmetrical profile is attained in the fully developed flow regime.     

9-azidoacridine, a new photoaffinity label for nucleotide- and aromatic-binding sites in proteins

The effect of the photolytic reagent 9-azidoacridine, optionally 3H-labelled, was studied both kinetically and structurally on nine different enzymes, namely alpha-chymotrypsin, lactate dehydrogenase, glyceraldehyde 3-phosphate dehydrogenase, alcohol dehydrogenase, alanine dehydrogenase, D-amino acid oxidase, ribonuclease A, alkaline phosphatase and alpha-amylase. Dark inhibition was observed in several cases. The concentration of the inhibitor ranged from 0.2 microM to 0.67 microM and demonstrated competitive kinetics with nucleotide cofactors when present. All concentrations of inhibitor showed increased inhibition on photolysis. Examination of the oligopeptides from hydrolysis of the covalently 3H-labelled derivative in conjunction with known amino acid sequence and tertiary structure established that the primary site of interaction in those cases for which the tertiary structure was available involved the active-site region. The above results in conjunction with those obtained with the structural analogues 9-aminoacridine and 9-amino-1,2,3,4-tetrahydroacridine established that this reagent acts as a molecular probe of aromatic- and, in particular, nucleotide-binding sites. This reagent provides a further additional method for studying the nucleotide cofactor domain.     

Efficient wireless reprogramming through reduced bandwidth usage and opportunistic sleeping

Wireless reprogramming of a sensor network is useful for uploading new code or for changing the functionality of existing code. Reprogramming may be done multiple times during a node’s lifetime and therefore a node has to remain receptive to future code updates. Existing reprogramming protocols, including Deluge, achieve this by bundling the reprogramming protocol and the application as one code image which is transferred through the network. The reprogramming protocol being complex, the overall size of the program image that needs to be transferred over the wireless medium increases, thereby increasing the time and energy required for reprogramming a network. We present a protocol called Stream that significantly reduces this bloat by using the facility of having multiple code images on the node. It pre-installs the reprogramming protocol as one image and equips the application program with the ability to listen to new code updates and switch to this image. For a sample application, the increase in size of the application image is 1 page (48 packets of 36 bytes each) for Stream and 11 pages for Deluge. Additionally, we design an opportunistic sleeping scheme whereby nodes can sleep during the period when reprogramming has been initiated but has not yet reached the neighborhood of the node. The savings become significant for large networks and for frequent reprogramming. We implement Stream on Mica2 motes and conduct testbed and simulation experiments to compare delay and energy consumption for different network sizes with respect to the state-of-the-art Deluge protocol.     

An efficient bi-layer content based image retrieval system

Multimedia Tools and Applications - Large amount of multi-media content, generated by various image capturing devices, is shared and downloaded by millions of users across the globe, every second....     

Varna-based optimization:a novel method for capacitated controller placement problem in SDN

Recently,software defined networking(SDN)is a promising paradigm shift that decouples the control plane from the data plane.It can centrally monitor and control the network through softwarization,i.e.,controller.Multiple controllers are a necessity of current SDN based WAN.Placing multiple controllers in an optimum way is known as controller placement problem(CPP).Earlier,solutions of CPP only concentrated on propagation latency but overlooked the capacity of controllers and the dynamic load on switches,which is a significant factor in real networks.In this paper,we develop a novel optimization algorithm named varna-based optimization(VBO)and use it to solve CPP.To the best of our knowledge,this is the first attempt to minimize the total average latency of SDN along with the implementation of TLBO and Jaya algorithms to solve CPP for all twelve possible scenarios.Our experimental results show that TLBO outperforms PSO,and VBO outperforms TLBO and Jaya algorithms in all scenarios for all topologies.     

Rumour detection using deep learning and filter-wrapper feature selection in benchmark twitter dataset

Multimedia Tools and Applications - Microblogs have become a customary news media source in recent times. But as synthetic text or ‘readfakes’ scale up the online disinformation...     

Impact Properties of Copper-Alloyed and Nickel-Copper Alloyed ADI

The influence of austenitization and austempering parameters on the impact properties of copper-alloyed and nickel-copper-alloyed austempered ductile irons (ADIs) has been studied. The austenitization temperature of 850 and 900 °C have been used in the present study for which austempering time periods of 120 and 60 min were optimized in an earlier work. The austempering process was carried out for 60 min for three austempering temperatures of 270, 330, and 380 °C to study the effect of austempering temperature. The influence of the austempering time on impact properties has been studied for austempering temperature of 330 °C for time periods of 30-150 min. The variation in impact strength with the austenitization and austempering parameters has been correlated to the morphology, size and amount of austenite and bainitic ferrite in the austempered structure. The fracture surface of ADI failed under impact has been studied using SEM.     

Performance improvement of 60‐GHz wireless optical systems with reverse‐parallel hybrid modulation scheme

This paper improves the performance of 60‐GHz wireless optical system including radio over fibre (RoF) and radio over free space optics (RoFSO), based on novel reverse‐parallel (RP) hybrid modulation scheme. This scheme combines the chromatic dispersion compensation technique of parallel modulation with energy efficiency manipulation technique of reverse modulation. Superior functioning of RoFSO is provided with reverse modulation compared with normal modulation. Comparative investigations are performed by loading 60‐GHz RF signal with 2.5 and 10‐Gbps data and modulating it with both reverse and hybrid modulators. Hybrid modulation performed better with improved BER of 10^?23 at distance of 51 km for 2.5‐Gbps data compared with reverse modulation with BER of 10^?7.