Identification of monofloral honey using voltammetric electronic tongue

Quality assessment of honey is often related to its floral origin which is a complex task to evaluate. Traditional technique of floral assessment is made by melissopalynological method. However, this method is quite time consuming and also often operator dependent. Thus, the fallout is a large range of error in interpretation of the result and hence there is considerable demand for instrumental methods to assess the identification of pollen in honey. In this pursuit, an electronic tongue based on cyclic voltammetry is developed to discriminate honey samples based on their floral types and is described in this paper. The technique has been investigated using platinum as the working electrode and the resultant current from the potentiostat has been considered for data analysis. The use of principal component analysis (PCA) and linear discriminate analysis (LDA) proves to be useful in clustering honey samples. Finally, classification performances are investigated using back-propagation multilayer perceptron (BP-MLP) and radial basis function (RBF) neural network models for identification of different floral origin of honey.     

Studies on high-performance blended/multiblended cements and their durability characteristics

Number of blends were prepared by intergrinding clinker, gypsum, fly ash, calcined clay, microsilica and limestone in laboratory ball mill in varying percentages, and their physical properties such as fineness, consistency, setting time and compressive strength have been determined. The durability tests on selected compositions were also conducted by exposing the mortar cubes separately in 5% Na₂SO₄ and 5% NaCl solutions till the age of 90 and 180 days. The performance was observed by compressive strength development criteria after various length of exposure. Results have been discussed and found that the durability of blended cement is higher than the ordinary Portland cement.     

Evaluation of major factors influencing the TBC topcoat formation in axial suspension plasma spraying (SPS)

Suspension plasma spraying (SPS) is ideally suited to produce porous or dense columnar, strain-tolerant thermal barrier coatings (TBCs) and also offers the possibility of producing other microstructures such as feathery and dense vertically cracked coatings. The specific properties of the TBC are significantly influenced by the formed microstructure, that is, affected by feedstock material and process parameters. In this work, the effects of various process parameters in the SPS process are investigated. It was found that the suspension feed rate has a significant effect on the microstructure, especially on the column density of the coating, whereas the suspension solids content mainly affects the coating porosity. Additionally, the surface roughness and topography of the bond coat are crucial for the formation of columnar coatings and were therefore investigated. Despite comparable roughness values for as-sprayed bond coats for high velocity oxy fuel and vacuum plasma spray produced coatings, the surface structures differ significantly from each other and affect the microstructure of the deposited topcoat. Characterization of mechanical properties by means of micro-indenter can be suitable for columnar coatings to determine Young's modulus within a column. However, due to the heterogeneity of the coating, the method is not suitable to describe the mechanical properties of the topcoat.     

Segregation and intermixing in polydisperse liquid–solid fluidized beds: A multifluid model validation study

Multifluid model (MFM) simulations have been carried out on liquid–solid fluidized beds (LSFB) consisting of binary and higher-order polydisperse particle mixtures. The role of particle–particle interactions was found to be as crucial as the drag force under laminar and homogenous LSFB flow regimes. The commonly used particle–particle closure models are designed for turbulent and heterogeneous gas–solid flow regimes and thus exhibit limited to no success when implemented for LSFB operating under laminar and homogenous conditions. A need is perceived to carry out direct numerical simulations of liquid–solid flows and extract data from them to develop rational closure terms to account for the physics of LSFB. Finally, a recommendation flow regime map signifying the performance of the MFM has been proposed. This map will act as a potential guideline to identify whether or not the bed expansion characteristics of a given polydisperse LSFB can be correctly simulated using MFM closures tested.     

A Weighted-Least-Squares Estimation Approach to Comparing Trends in Age-Adjusted Cancer Rates Across Overlapping Regions

Li and Tiwari (2008) recently developed a corrected Z-test statistic for comparing the trends in cancer age-adjusted mortality and incidence rates across overlapping geographic regions, by properly adjusting for the correlation between the slopes of the fitted simple linear regression equations. One of their key assumptions is that the error variances have unknown but common variance. However, since the age-adjusted rates are linear combinations of mortality or incidence counts, arising naturally from an underlying Poisson process, this constant variance assumption may be violated. This paper develops a weighted-least-squares based test that incorporates heteroscedastic error variances, and thus significantly extends the work of Li and Tiwari. The proposed test generally outperforms the aforementioned test through simulations and through application to the age-adjusted mortality data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute.     

Polypropylene-elastomer (TPO) nanocomposites: 2. Room temperature Izod impact strength and tensile properties

Room temperature Izod impact strength was determined for polypropylene (PP)/ethylene-co-octene elastomer (EOR) blends and nanocomposites, containing organoclays based on montmorillonite (MMT), at fixed elastomer content of 30 wt% and 0-7 wt% MMT. A ratio of maleated polypropylene, PP-g-MA to organoclay of unity was used as a compatibilizer in the nanocomposites. The organoclay serves to reduce the size of the EOR dispersed phase particles and facilitates toughening. The Izod impact strength is also influenced by the molecular weight of PP, elastomer octene content, elastomer MFI in addition to MMT content. Nanocomposites based on a low molecular weight polypropylene (L-PP) containing a higher octene content elastomer showed higher impact strength at lower MMT contents compared to those based on a low octene content elastomer. The effect of elastomer octene content on impact strength of high molecular weight polypropylene (H-PP) nanocomposites is not so significant. Elastomers having a melt flow index (MFI) in the range of 0.5-1.0 showed significant improvement in the impact strength of L-PP based nanocomposites. Most H-PP/EOR blends gave ‘super-tough’ materials without MMT and maintain this toughness in the presence of MMT. The critical elastomer particle size below which the toughness is observed is reduced by decreasing the octene content of the elastomer. For the similar elastomer particle sizes in nanocomposites, the impact strength varies as H-PP > M-PP > L-PP. The tensile modulus and yield strength improved with increasing MMT content; however, elongation at break was reduced. The extruder-made TPO showed a good-balance of properties in the presence of MMT compared to reactor-made TPO having similar modulus and elastomer content.     

Scalable synthesis of aligned carbon nanotubes bundles using green natural precursor: neem oil

Practical application of aligned carbon nanotubes (ACNTs) would have to be determined by a matter of its economical and large-scale preparation. In this study, neem oil (also named Margoaa oil, extracted from the seeds of the neem--Azadirachta indica) was used as carbon source to fabricate the bundles of ACNTs. ACNTs have been synthesized by spray pyrolysis of neem oil and ferrocene mixture at 825°C. The major components of neem oil are hydrocarbon with less amount of oxygen, which provided the precursor species in spray pyrolysis growth of CNTs. The bundles of ACNTs have been grown directly inside the quartz tube. The as-grown ACNTs have been characterized through Raman spectroscopy, scanning and transmission electron microscopic (SEM/TEM) techniques. SEM images reveal that the bundles of ACNTs are densely packed and are of several microns in length. High-resolution TEM analysis reveals these nanotubes to be multi-walled CNTs. These multi-walled CNTs were found to have inner diameter between 15 and 30 nm. It was found that present technique gives high yield with high density of bundles of ACNTs.     

Role of interface on dynamic modulus of high‐performance poly(etheretherketone)/ceramic composites

High‐performance printed circuit board or electronic packaging substrate with low warping particularly at high frequency is the key demand of manufacturers. In the present work, poly(etheretherketone) (PEEK) matrix composites reinforced with untreated micron size aluminum nitride (AlN) and alumina (Al₂O₃) particles have been studied for dynamic modulus in the temperature range varying from 30 to 250°C. At 48 vol % particles, the room temperature modulus of the PEEK/AlN composites increased by approximately fivefold (～ 23 GPa), whereas it increased by twofold for PEEK/Al₂O₃ composite. The reinforcing efficiency is more pronounced at higher temperatures. The significant improvement in modulus was attributed to the better adhesion between the matrix and the AlN particles. Scanning electron microscope (SEM) and Kubat parameter showed that the poor adhesion between the matrix and the Al₂O₃ particles resulted in comparatively smaller increase in modulus of PEEK/Al₂O₃, despite higher intrinsic modulus of Al₂O₃ than that of AlN. SEM showed almost uniform distribution of particles in the matrix. The experimental data were correlated with several theoretical models. The Halpin–Tsai model with ξ (xi) is equal to four correlates well up to 48 vol % AlN composites while ξ is equal to two correlates only up to 18 vol % Al₂O₃ composites. Guth–Smallwood model also correlates well up to 28 vol % AlN and 18 vol % Al₂O₃‐filled composites. Thereafter, data deviated from it due to the particles tendency to aggregate formation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Study on coke size degradation from coke plant wharf to blast furnaces stock house

The gas permeability, which is one of the most important requirements served by coke, is dependent largely on the size distribution of the coke at the various zones in the blast furnace. This papers deals with breakage of coke when it travels from wharf to blast furnace. In this study, six different coal blend samples in the range of 23.6–25.0% volatile matter and 11.7–14.8% ash were studied in stamp charged coke making process (wet bulk density 1.15 t/m³). The coke samples were collected from battery no. 8 wharf, CK06 (conveyer belt) and auto sampler. All experiments were conducted on shatter machine and an attempt has been made to find out reasons for breakage of coke. Results indicate that the coke size degradation is function of transporting system and dropping height of coke from wharf to blast furnace. It was also found that in stamp charging condition, it is possible to improve yield of blast furnace grade coke even at higher composition balance index of coal blend (2.94–3.70).