Evaluation of hydroxyapatite and β-tri calcium phosphate microplasma spray coated pin intra-medullary for bone repair in a rabbit model

Here we report a comparative study of the healing kinetics of surgically created artificial defects in the tibia of New Zealand white rabbits. Comparison of the healing kinetics was made for uncoated conventional SS316L intramedullary pins, and the same pins with microplasma sprayed (MIPS) pure hydroxyapatite (HAp) and beta-tri calcium phosphate (β-TCP) coatings. After thorough material characterizations including XRD, FTIR, SEM, etc., MIPS coated pins were implanted to such animals. Serum biochemistry, radiology and fluorochrome labelling were used to evaluate the comparative healing kinetics of these implants in vivo. In comparison to those of the uncoated pins, the pins coated with both MIPS HAp and β-TCP showed significant increment of alkaline phosphatase up to 15th postoperative day, insignificant changes in serum phosphorus and calcium with uneventful healing of bone defect. There was development of Havarsian canals and well-defined peripherally placed osteoblasts along with evidence of angiogenesis and comparatively more new bone formation in the defect site. On a comparative scale, the performance of the β-TCP coated intramedullary pins was much better than that of the pure HAp coated pins than the uncoated intramedullary pins.     

Ytterbium-Doped P$_2$O$_5$-TeO $_2$ Glass for Laser Applications

Ytterbium-doped sodium phospho-tellurite glasses are made with different P₂O₅:TeO₂ ratio, and Yb³⁺ concentrations. Physical properties of the new Yb hosts are favorable for laser applications. The glasses show high absorption and emission cross sections and higher lifetime of Yb³⁺:²F_5/2rarr²F_7/2 transition. The emission cross sections are calculated using two different methods and compared. The laser parameters of these Yb³⁺ -doped glasses are better than many reported glasses and crystals making them potential to fabricate high power laser and broadband optical amplifier in the wavelength region around ~1 mum     

Microprocessor controlled FSK/PSK wave modulation: experimentalmodel for a digital communication laboratory

A simple digitally programmable oscillator (DPO) based on a two-integrator loop is described. A simple experimental model for signal processing/generation (e.g., frequency shift keying, amplitude shift keying, phase shift keying/binary phase shift keying) useful in digital communication has been derived from the DPO by employing a microprocessor. The setup can be conveniently utilized for demonstration and experimentation in the communications laboratory. Some test results are included     

Detecting Ambiguities in Regression Problems using TSK Models

Regression refers to the problem of approximating measured data that are assumed to be produced by an underlying, possibly noisy function. However, in real applications the assumption that the data represent samples from one function is sometimes wrong. For instance, in process control different strategies might be used to achieve the same goal. Any regression model, trying to fit such data as good as possible, must fail, since it can only find an intermediate compromise between the different strategies by which the data were produced. To tackle this problem, an approach is proposed here to detect ambiguities in regression problems by selecting a subset of data from the total data set using TSK models, which work in parallel by sharing the data with each other in every step. The proposed approach is verified with artificial data, and finally utilised to real data of grinding, a manufacturing process used to generate smooth surfaces on work pieces.     

Visual perception-based criminal identification: a query-based approach

Abstract

The visual perception of eyewitness plays a vital role in criminal identification scenario. It helps law enforcement authorities in searching particular criminal from their previous record. It has been reported that searching a criminal record manually requires too much time to get the accurate result. We have proposed a query-based approach which minimises the computational cost along with the reduction of search space. A symbolic database has been created to perform a stringent analysis on 150 public (Bollywood celebrities and Indian cricketers) and 90 local faces (our data-set). An expert knowledge has been captured to encapsulate every criminal’s anatomical and facial attributes in the form of symbolic representation. A fast query-based searching strategy has been implemented using dynamic decision tree data structure which allows four levels of decomposition to fetch respective criminal records. Two types of case studies - viewed and forensic sketches have been considered to evaluate the strength of our proposed approach. We have derived 1200 views of the entire population by taking into consideration 80 participants as eyewitness. The system demonstrates an accuracy level of 98.6% for test case I and 97.8% for test case II. It has also been reported that experimental results reduce the search space up to 30 most relevant records.     

Precise realisation of an insensitive floating negative admittance convertor

A new floating negative admittance convenor (FNAC) network using the second-generation current conveyor (CCII) active devices has been proposed. The novelties of the scheme are no component matching requirements, use of only the nominal termination admittance under ideal device conditions, and practically active-insensitive network characteristics. Even with nonideal but matched devices, no extra matching component is required for a true FNAC realisation. However, with nonideal and nonidentical devices, insertion of a single compensating admittance yields a precise bilateral FNAC.     

Quality of signals reconstructed from degraded Fourier transform phase

Through a series of simulations with one dimensional real digital signals, the effects of various degrees of phase degradation for different lengths of sequences and for different choices in the set of sampling frequencies on the quality (as measured by normalised mean-square-error-NMSE) of signals reconstructed from noisy Fourier transform (FT) phases is established.<>     

Fast masking algorithms for image analysis

The possibility and the construction of a number of fast algorithms for the two-dimensional masking of small mask sizes is clearly demonstrated. These are based on nesting and represent extension of the ideas of Stasinski (1990). Moreover, the authors explain how to make the optimal choice of the algorithm depending on the computational machine available.<>     

A high-quality dual-input differentiator

A dual-input ideal differentiator network design with a single resistor-controlled time constant and high-gain operational amplifier (OA) devices is described. At high frequencies, the network becomes functionally nonideal and its quality factor (Q) degrades because of the frequency-dependent gain of the OA. A suitable Q-compensation design that yields a 1:|A|² order of Q improvement at higher frequencies is proposed. The network exhibits high-frequency deemphasis characteristics due to the OA-poles which would suppress the high-frequency noise components