Separation and characterization of bitumen from Athabasca oil sand

Separation and chemical analysis was investigated using bitumen samples from Athabasca oil sand in Alberta. Fractionation according to solubility and polarity has been used to separate bitumen into its fractions. The solvent de-asphaltening was performed by n-pentane solvent (solubility fractionation), and the polarity fractionation using Fuller’s earth allows maltene to separate into SARA components (saturates, aromatics, resins and asphaltenes). The SARA components are analyzed comprehensively using elemental analysis (EA), Fourier-transformed infrared (FTIR), ultraviolet-visible spectroscopy (UV-vis), high performance chromatography (HPLC) and thermogravimetric analysis (TGA). EA (C, H, N, S), heavy metals (Ni, V) concentrations, FT-IR and UV-vis tests provided the explanation of chemical composition. From IR spectra, maltene and saturates/aromatics (sat/aro) contained more aliphatic compounds than resin or asphaltene. Also, IR spectrum of sat/aro was similar to crude oil and VGO (vacuum gas oil). Different UV signal data clearly indicates the contribution of aromatic constituents in the fractions. Using optimized analysis conditions of HPLC, we successfully separated the peaks for bitumen and its fractions. The characteristic peak pattern of SARA (saturates, aromatics, resins, asphaltenes) fractions was observed, and also the peak pattern of sat/aro was similar to that of crude oil and VGO. However, TGA results revealed that thermal behavior for sat/aro was similar to that of crude oil but different from that of VGO. Also, from the comparison between decomposition temperature of TGA and boiling point, their correspondence was found.     

Microstructures,Forming Limit and Failure Analyses of Inconel 718 Sheets for Fabrication of Aerospace Components

Recently, aerospace industries have shown increasing interest in forming limits of Inconel 718 sheet metals, which can be utilised in designing tools and selection of process parameters for successful fabrication of components. In the present work, stress-strain response with failure strains was evaluated by uniaxial tensile tests in different orientations, and two-stage work-hardening behavior was observed. In spite of highly preferred texture, tensile properties showed minor variations in different orientations due to the random distribution of nanoprecipitates. The forming limit strains were evaluated by deforming specimens in seven different strain paths using limiting dome height (LDH) test facility. Mostly, the specimens failed without prior indication of localized necking. Thus, fracture forming limit diagram (FFLD) was evaluated, and bending correction was imposed due to the use of sub-size hemispherical punch. The failure strains of FFLD were converted into major-minor stress space (σ-FFLD) and effective plastic strain-stress triaxiality space (ηEPS-FFLD) as failure criteria to avoid the strain path dependence. Moreover, FE model was developed, and the LDH, strain distribution and failure location were predicted successfully using above-mentioned failure criteria with two stages of work hardening. Fractographs were correlated with the fracture behavior and formability of sheet metal.     

Simultaneous extraction of optical transport parameters and intrinsic fluorescence of tissue mimicking model media using a spatially resolved fluorescence technique

We present a method based on spatially resolved fluorescence measurement for the simultaneous estimation of optical transport parameters, namely, the reduced scattering coefficient (micro s'), the absorption coefficient (micro a), and the intrinsic fluorescence spectra from turbid media. The accuracy of this approach was tested by conducting studies on a series of tissue-simulating phantoms with known optical transport properties. The estimated relative error in the values for micro s' and micro a using this technique was found to be < or =10%. Furthermore, the line shape and intensity of the intrinsic fluorescence recovered by using this approach were observed to be free from the distorting effects of the wavelength-dependent absorption and scattering properties of the medium, and they were in excellent agreement with the directly measured intrinsic fluorescence spectra of the fluorophores.     

Real and perceived attitude agreement in social networks.

It is often asserted that friends and acquaintances have more similar beliefs and attitudes than do strangers; yet empirical studies disagree over exactly how much diversity of opinion exists within local social networks and, relatedly, how much awareness individuals have of their neighbors' views. This article reports results from a network survey, conducted on the Facebook social networking platform, in which participants were asked about their own political attitudes, as well as their beliefs about their friends' attitudes. Although considerable attitude similarity exists among friends, the results show that friends disagree more than they think they do. In particular, friends are typically unaware of their disagreements, even when they say they discuss the topic, suggesting that discussion is not the primary means by which friends infer each other's views on particular issues. Rather, it appears that respondents infer opinions in part by relying on stereotypes of their friends and in part by projecting their own views. The resulting gap between real and perceived agreement may have implications for the dynamics of political polarization and theories of social influence in general. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group character tables in discrete transform theory

It has been shown that a transform satisfying a generalized form of the convolution theorem can be described by the group character table of an appropriate finite Abelian group G. Exact correspondence between the transform properties and the underlying group properties is established and it has been demonstrated that many of the digital signal processing problems may be solved efficiently using the group theoretic approach. Sets of permutations are fully characterized such that a permutational convolution defined with respect to them can be converted into a transform product by some invertible transform.     

Effect of Specifications Type on the Quality of Paving Contracts in New Brunswick

Construction specifications are used by transportation agencies to define the client’s requirements of the final product. The primary motivation of adopting the newer end result specification (ERS) or performance related specification over method-based specification (MBS) is to reduce clients’ costs, encourage contractors’ innovation, and improve overall quality. However, some transportation agencies have been reluctant to fully implement ERS due to lack of demonstrated evidence on whether they achieve comparable level of quality or performance. This paper investigates if the specification type has any effect on quality. The case study presented is based on data from New Brunswick Department of Transportation (NBDOT) from years 2003–2007. NBDOT generally uses ERSs to call paving contracts equal to or larger than 8,000 t. MBSs are used for all other smaller paving contracts. The most prevalent indicator variables for accepting asphalt paving jobs in North America [that is, percent theoretical maximum relative density, asphalt binder content, air voids, voids in mineral aggregates, percent passing 4.75 mm (No. 4), and 75?μm (No. 200) sieves] were investigated. Statistical analysis was performed to compare the deviation of the quality indicator variables from their respective job mix formula values for paving projects that used MBS or ERS. ANOVA results revealed that there were no significant differences between the qualities achieved from the two specification types. Also, no significant differences were found from within-specification comparisons over the time frame examined. Given the possible cost advantages from agency’s point of view, the flexibility of the contractors to innovate and the fact that this study demonstrates quality is not compromised, there is an opportunity for agencies to expand or fully adopt the use of ERS specifications.     

Monitoring changes in land use land cover of Yamuna riverbed in Delhi: a multi-temporal analysis

Impact of anthropogenic activities has led to significant changes in riverbeds over a period of time. The objective of the study was to monitor the land use land cover (LULC) of Yamuna riverbed in Delhi and to assess the changes due to natural and anthropogenic activities. The maximum likelihood classification was carried out by using March 1977, April 1999, April 2002 and February 2009 imageries. An overall accuracy of LULC classification of 2009 imagery was around 88.6% based on ground truth data. A significant reduction in the main river course and increase in agricultural activities as well as built up were observed in remote sensing analysis as an outcome of riverbed encroachments. The changed scenario of riverbed not only stresses the riverine ecosystem but also jeopardizes the future consequences on river hydraulics.     

Designer,Programmable DNA-peptide hybrid materials with emergent properties to probe and modulate biological systems

The chemistry of DNA endows it with certain functional properties that facilitate the generation of self-assembled nanostructures, offering precise control over their geometry and morphology, that can be exploited for advanced biological applications. Despite the structural promise of these materials, their applications are limited owing to lack of functional capability to interact favourably with biological systems, which has been achieved by functional proteins or peptides. Herein, we outline a strategy for functionalizing DNA structures with short-peptides, leading to the formation of DNA-peptide hybrid materials. This proposition offers the opportunity to leverage the unique advantages of each of these bio-molecules, that have far reaching emergent properties in terms of better cellular interactions and uptake, better stability in biological media, an acceptable and programmable immune response and high bioactive molecule loading capacities. We discuss the synthetic strategies for the formation of these materials, namely, solid-phase functionalization and solution-coupling functionalization. We then proceed to highlight selected biological applications of these materials in the domains of cell instruction & molecular recognition, gene delivery, drug delivery and bone & tissue regeneration. We conclude with discussions shedding light on the challenges that these materials pose and offer our insights on future directions of peptide-DNA research for targeted biomedical applications.