Fast enumeration of every path in a reliability graph using subgraphs

A fast method has been proposed for enumeration of all possible pathsets from every node to all other nodes using subgraphs. The method efficiently identifies the elements as well as source, sink and other nodes constituting a path. It performs no multiplications other than a few additions of binary digits.     

A unit-based,cost-efficient scheduler for heterogeneous Hadoop systems

The Journal of Supercomputing - A significant amount of research in the field of job scheduling is carried out in Hadoop. However, there is still need for research to overcome some challenges...     

CAD-integrated analysis of 3-D beams: a surface-integration approach

Most engineering artifacts are designed and analyzed today within a 3-D computer aided design (CAD) environment. However, slender objects such as beams are designed in a 3-D environment, but analyzed using a 1-D beam-element, since their 3-D analysis exhibits locking and/or is computationally inefficient. This process is tedious and error-prone. Here, we propose a dual-representation strategy for designing and analyzing 3-D beams, directly within a 3-D CAD environment. The proposed method exploits classic 1-D beam physics, but is implemented within a 3-D CAD environment by appealing to the divergence theorem. Consequently, the proposed method is numerically and computationally equivalent to classic 1-D beam analysis for uniform cross-section beams. But, more importantly, it closely matches the accuracy of a full-blown 3-D finite element analysis for non-uniform beams.     

Characterisation of R.F. magnetron sputtered Cr-N,Cr-Zr-N and Zr-N coatings

Binary Cr-N, Zr-N and Cr-Zr-N films were synthesised using a R.F. reactive magnetron sputtering technique by co-sputtering Cr and Zr. The crystalline structure, morphology, mechanical and tribological properties of the films as a function of Zr content were characterised by X-ray diffraction, microanalysis X (WDS, EDS), X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, nanoindentation, scratch adhesion and pin-on-disc sliding wear tests. The residual stress was calculated with the Stoney formula. The Cr-Zr-N films exhibit a two-phase microstructure, containing a cubic (CrN, ZrN) with hexagonal (Cr₂N, Zr₂N) phases, as shown by X-ray diffraction. As the Zr content increased, a columnar and compact structure is developed with a low surface roughness. The results reveal that the mechanical and tribological properties of the films were found to depend on the Zr content and the hardness (maximum 26.3?GPa) is greatly improved in comparison with CrN and ZrN films, especially at 31?at.-% Zr. In the scratch test, the hardest film (Cr_0.18Zr_0.31N_0.47) exhibited an adhesive failure at Lc_2?=?34.3?N.     

UHMWPE Hybrid Nanocomposites for Improved Tribological Performance Under Dry and Water-Lubricated Sliding Conditions

To tap the full potential of polymers to be used as tribo-materials under water lubrication, it is very important to improve their resistance to water uptake on the one hand and improve their strength and load bearing capacity on the other so that their performance under these conditions is not deteriorated. Hence, a unique approach of fabricating a hybrid polymer nanocomposite reinforced with nanoclay for improving the resistance to water uptake and carbon nanotubes (CNTs) to improve the mechanical/tribological properties is undertaken. Ultrahigh molecular weight polyethylene (UHMWPE) hybrid nanocomposites were fabricated via ball milling followed by hot pressing method. Functionalized multi-wall CNTs and C15A organoclay were used as nanofillers in UHMWPE matrix. Hybrid nanocomposites were developed with CNT loadings of 0.5, 1.5 and 3.0 wt% while keeping C15A organoclay content fixed at an optimized value of 1.5 wt%. Initially, the hybrid nanocomposites were optimized under dry sliding conditions whereby a loading of 1.5 wt% of CNTs and 1.5 wt% C15A organoclay resulted in the maximum reduction in the specific wear rate by about 64% as compared to pristine UHMWPE. Later, tribological performance of the optimized hybrid nanocomposite was compared with pristine UHMWPE and its UHMWPE nanocomposites under water-lubricated conditions sliding against a 440C stainless steel ball for 150,000 cycles. The specific wear rate showed a reduction by ~46% for the 1.5 wt% CNTs hybrid nanocomposites as compared to pristine UHMWPE under water lubrication. The improved resistance to wear was attributed to the uniform dispersion of both the nanofillers, namely CNTs and C15A organoclay which effectively increased the load bearing capacity of UHMWPE. Moreover, the excellent barrier properties of the platelet-like structure of C15A clay which presented a torturous path for the diffusion of the water molecule in UHMWPE reduced the softening of the surface layer leading to better resistance to wear under water lubrication.     

Physical,mechanical, and in vitro biological analysis of bioactive fibers-based dental composite

This study aimed to synthesize experimental composites reinforced with various concentrations (0, 40, 50, and 60 wt%) of nano-hydroxyapatite grafted glass fibers. The release of monomers, residual monomers, and in-vitro bioactivity of composite groups were evaluated after 1, 7, and 28 days. Compressive strength/ modulus, cell viability (by direct and indirect method), and bacterial adhesion were evaluated. The results showed that bis-GMA was released from all samples. TEGDMA released from 50 and 60 wt% samples on day 1 and UDMA showed negligible release. Compressive strength values of 40 wt% sample were higher than other experimental groups. New apatite layer was formed, whereby both direct and indirect methods demonstrated cell viability. The numbers of active colonies grown were least for 60 wt% sample while their number increased over time. The nano-hydroxyapatite/glass fibers have potential to be used as filler in dental composites and experimental composites were found to be biocompatible and comparable with commercial material.     

Computational modeling and experimental infrared spectroscopy of hydrogen bonding interactions in polyvinyl alcohol-starch blends

This study aims to investigate the hydrogen bonding interactions in polyvinyl alcohol (PVOH)-starch blends. Semi-empirical AM1 (Austin Model 1) and PM3 (Parameterized Austin Model 3) methods were employed to model the blending. Binding energies, vibrational frequencies and solubility parameters results were used to analyze the compatibility and stability of the blends. Besides that, experimental infrared spectroscopy was also conducted to validate the modeling results. The computed negative binding energies justified the stability of the blending. On the other hand, the solubility parameters of PVOH and starch modeling complexes have been found close to each other. This confirms that PVOH and starch are compatible blends. In addition, vibrational frequency analysis of these molecular complexes has exhibited that the hydroxyl group shifts to lower wavenumbers due to formation of hydrogen bonds. Findings from the experimental infrared spectroscopy have shown agreement with computational vibrational frequency results. The wavenumbers of the specimens increase is dependent on the ratios of PVOH in the blends. Such increment indicates that PVOH and starch interact in a harmonize manner and the blending is compatible.     

Quantum dots: synthesis, bioapplications, and toxicity

ABSTRACT: This review introduces quantum dots (QDs) and explores their properties, synthesis, applications, delivery systems in biology, and their toxicity. QDs are one of the first nanotechnologies to be integrated with the biological sciences and are widely anticipated to eventually find application in a number of commercial consumer and clinical products. They exhibit unique luminescence characteristics and electronic properties such as wide and continuous absorption spectra, narrow emission spectra, and high light stability. The application of QDs, as a new technology for biosystems, has been typically studied on mammalian cells. Due to the small structures of QDs, some physical properties such as optical and electron transport characteristics are quite different from those of the bulk materials.     

Green synthesis of silver nanoparticles using Zingiber officinale and Thymus vulgaris extracts: characterisation,cell cytotoxicity,and its antifungal activity against Candida albicans in comparison to fluconazole

Fluconazole (FLZ) application as a highly successful commercial antifungal azole agent to treat the fungal infections is limited due to emergence of FLZ‐resistant candida. In this study, the potential of green synthesised silver nanoparticles (NPs) as an antifungal agent against Candida albicans fungal pathogen is investigated. The extract of ginger (Zingiber officinale) and thyme (Thymus vulgaris) plays as reducing agent, capping agent and antifungal agent. The UV–visible spectroscopy shows the peak of surface plasmon resonance of synthesised Ag NPs after a period of time. The synthesised Ag NPs are spherical, with average sizes of 12 and 18 nm based on ginger and thyme extract, respectively. Fourier transform infrared spectroscopy confirms the adsorption of the plant extract on the surface of the as‐prepared Ag NPs. Based on the minimum inhibitory concentration (MIC) method against Candida albicans, the antifungal activity of as‐prepared green synthesised Ag NPs shows higher inhibitory in comparison to FLZ. Finally, the Ag NPs synthesised via thyme extract shows no cytotoxicity with concentration below 3.5 ppm, which can be considered as an appropriate candidate instead of FLZ to treat the superficial fungal infections.Inspec keywords: nanoparticles, surface plasmon resonance, adsorption, nanofabrication, particle size, silver, ultraviolet spectra, antibacterial activity, visible spectra, microorganisms, nanomedicine, Fourier transform infrared spectra, biomedical materials, diseases, materials preparation, cellular biophysicsOther keywords: green synthesis, cell cytotoxicity, antifungal activity, fluconazole application, FLZ‐resistant candida, green synthesised silver nanoparticles, antifungal agent, surface coating, surface plasmon resonance, superficial fungal infections, Zingiber officinale, UV‐visible spectroscopy, Thymus vulgaris extracts, antifungal azole agent, Candida albicans fungal pathogen, plant extracts, ginger, Fourier transform infrared spectroscopy, minimum inhibitory concentration method, Ag