Quantum cheques

We propose the idea of a quantum cheque scheme, a cryptographic protocol in which any legitimate client of a trusted bank can issue a cheque, that cannot be counterfeited or altered in anyway, and can be verified by a bank or any of its branches. We formally define a quantum cheque and present the first unconditionally secure quantum cheque scheme and show it to be secure against any no-signalling adversary. The proposed quantum cheque scheme can been perceived as the quantum analog of Electronic Data Interchange, as an alternate for current e-Payment Gateways.     

Structural effects in the superconductor NbTi65

Annealed and metallurgical processed Nb-65 wt % Ti material is extensively investigated in the temperature range of 4–300 K. By means of transmission electron microscopy the premartensitic phase and athermal martensite are shown to exist. The microscopic event of pseudoelasticity is observed when the metastable phase is strained in the cold stage. The deformation-induced morphological instabilities are discussed in view of the training behavior of superconductors.     

Energy density based mobile sink trajectory in wireless sensor networks

Microsystem Technologies - Sink mobility is one of the efficient solutions to sink hole or energy hole problem which is usually caused by multi-hop communication using a static sink. However, the...     

Synthesis of organic derived hydroxyapatite scaffold from pig bone waste for tissue engineering applications

Micro porous hydroxyapatite (HAp) had drawn great attention in the field of tissue engineering due to its numerous applications such as tissue regeneration, dental, drug delivery, and adsorption and desorption of substances etc. The chemical synthesis of HAp is often faced with the high cost of starting materials and often lacks the presence of beneficial ions which can promote biological reactions. This paper examined a novel application of pig bone waste for the synthesis of HAp via heat treatment between 600 and 1000 °C. Thus synthesized powder was characterized by X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDX) and Transmission electron microscopy (TEM). XRD results revealed the main characteristic peaks of single phase HAp powder, while the presence of various functional groups such as PO₄^3?, CO₃^2? and OH^? corresponding to HAp were observed by FT-IR analysis. The elemental composition of as-synthesized HAp powder as observed by EDX showed the presence of Ca and P in addition to some beneficial metals such as Na, K, Mg and Si which plays vital roles in biological applications. SEM and TEM observation confirmed the microscopic sctructure of the as-synthesized HAp to be rod-like morphology with 38–52 nm in length. Porous HAp scaffold up to 65% porosity could be prepared using ammonium bicarbonate as pore forming agent. Therefore, bio-waste such as pig bones can be utilized in the synthesis of porous hydroxyapatite scaffold which can serve as an alternative for the conventional chemical method.     

A multi-agent-based framework for cloud service discovery and selection using ontology

As cloud computing is getting matured day by day, there has been overwhelming interest among the users to avail a plethora of cloud services. Often, these services appear identical in terms of their functionality though they differ in pricing models, computational power, storage policies and Quality-of-Service parameters making the process of service discovery and selection an intricate task. In the absence of any standard specifications, cloud service providers continue to use their own vocabulary and this further complicates the selection process. Even popular search engines like Google and MSN are not efficient enough to properly identify the most appropriate cloud service that can meet customer requirements. Thus, in the presence of multiple selection parameters and constraints, selecting a required cloud service is a daunting task. In order to address this issue, we work toward developing a reasoning mechanism to optimally resolve the similarities across cloud services by using cloud ontology. A multi-agent-based framework has been proposed for effective cloud service discovery and selection with the help of a standardized service registry and by employing semantically guided searching process.     

Estimation for the three-parameter lognormal distribution based on progressively censored data

Some work has been done in the past on the estimation of parameters of the three-parameter lognormal distribution based on complete and censored samples. In this article, we develop inferential methods based on progressively Type-II censored samples from a three-parameter lognormal distribution. In particular, we use the EM algorithm as well as some other numerical methods to determine maximum likelihood estimates (MLEs) of parameters. The asymptotic variances and covariances of the MLEs from the EM algorithm are computed by using the missing information principle. An alternative estimator, which is a modification of the MLE, is also proposed. The methodology developed here is then illustrated with some numerical examples. Finally, we also discuss the interval estimation based on large-sample theory and examine the actual coverage probabilities of these confidence intervals in case of small samples by means of a Monte Carlo simulation study.     

Impedance spectroscopy study of LaMnO3 modified BaTiO3 ceramics

Ba_0.97Ti_0.97La_0.02Mn_0.04O₃ nanocrystalline powder was prepared by chemical route with the help of soluble tartarate complex of Ti⁴⁺ ion. Preliminary X-ray diffraction analysis of crystal structure showed that a single-phase compound was formed exhibiting tetragonal system. Average crystallite size and particle size were observed to be between 27 and 33 nm, which were analyzed through XRD and transmission electron microscope respectively. Wide range impedance spectroscopy study from 200 to 600 °C showed the presence of both bulk and grain boundary effects up to 500 °C. The bulk conductivity indicated an Arrhenius-type thermally activated process and oxygen vacancies are the possible ionic charge carriers at higher temperatures. The variation of ac conductivity as a function of frequency indicated the possibility of hopping mechanism for electrical process in the system with a non-exponential type of conductivity relaxation.     

Synthesis of Inorganic Polymeric Materials from Industrial Solid Waste

Silicon - The present paper highlights the high strength of inorganic polymer (geopolymer) prepared from industrial solid waste. Fly ash (industrial solid waste) was used as the starting raw...     

Tribological Behaviour of Electroless Ni-P Deposits Under Elevated Temperature

Electroless Ni-P (EN) coatings have already proven their aptness for improving the tribological performance of the base material. This is possible due to their high hardness, good wear resistivity and corrosion resistance. However, the performance evaluation of the EN coatings under high temperature or the assessment of their thermal stability is yet to be conducted. The present work deals with the study of tribological characteristics viz. friction and wear of EN coatings at elevated temperatures (100 °C, 300 °C and 500 °C) by varying the tribological testing parameters viz. applied load and sliding velocity. A detailed study of the tribological behaviour of the coating is undertaken individually for the as-deposited and heat treated samples. The results obtained are compared among each other and also with that of the room temperature (RT) tests of the coating. It is found that the friction coefficient (COF) and wear rate of EN coatings mostly increases with increase in load for all the test temperatures. However, for variation in sliding velocity, both COF and wear rate show a reverse trend. The as-deposited samples show lesser wear rate particularly at high temperature, which may be because of the in situ heat treatment received during the test. The asdeposited coatings yield better results especially when the test temperature is kept above or near the phase transformation temperature of the coating. The surface morphology, composition of coatings and crystalline structure are studied with the help of scanning electron microscopy, energy dispersed X-ray analysis and X-ray diffraction analysis respectively. The coating displays a nodular morphology and is amorphous in the as-deposited phase.With heat treatment, the coating turns crystalline. A mixed adhesive and abrasive wear mechanism is observed for the EN coatings tested at elevated temperature. Adhesive wear is accompanied by micro-cracks. Tribo-oxidation is confirmed from energy dispersive X-ray spectrometry.