Physicochemical characterization of the filler–matrix interface in elastomer‐encapsulated fly ash/polyester particulate composites

An attempt was made to improve the toughness of fly ash (FA)/general‐purpose unsaturated polyester resin (GPR) composites. Elastomer [styrene–butadiene rubber (SBR) or acrylic copolymer (AC)]‐encapsulated fillers (FA or CaCO₃) were made through the coagulation of the emulsified elastomer containing the filler with constant stirring. The elastomer‐encapsulated fillers were added to GPR at concentrations as high as 15 wt % to make FA/SBR or AC/GPR composites. The mechanical properties (i.e., the tensile strength, tensile modulus, tensile elongation, flexural strength, flexural modulus, impact strength, and hardness) of FA/GPR, FA/SBR/GPR, and FA/AC/GPR composites were studied. The tensile‐fractured surfaces of all the composites were studied with scanning electron microscopy. The thermal stability was studied with thermogravimetric analysis. An analysis of the results indicate that this modification technique is rather easy and more economical than the chemical modification of filler surfaces with functional silane coupling agents. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 171–184, 2005     

Synthesis and spectroscopic studies on novel Cu(II)–Cu(II) binuclear adducts. EPR evidence for ferromagnetic interactions

EPR investigations on two solid complexes [Cu(1-amidino-O-2-methoxyethylurea)₂]₂(H₂O)₂(SO₄)₂ (1) and [Cu(1-amidino-O-2-ethoxyethylurea)₂]₂(H₂O)₂(SO₄)₂ (2) indicated the formation of ferromagnetically coupled binuclear complexes (S = 1) having the isotropic exchange interaction constant J values of 59 and 50 cm⁻¹. The angle between the Cu–Cu direction and the parallel direction (ξ) of the complex 1 has been evaluated. The IR studies suggest the presence of tetrahedral sulfate ion in the complexes. When the EPR spectra were recorded in the temperature range 300–475 K, it was observed that the triplet-state EPR signal disappeared completely and irreversibly at ca. 450 K for complex 1 and at ca. 475 K for complex 2 with the appearance of a new signal attributable to the mononuclear complex (S = 1/2).     

Trustworthy Scan Design and Testability Using Obfuscation and Logic Locking Scheme for Wireless Network Application

Mobile Networks and Applications - The wireless network (WN) has become an integral part of the living habits of human beings. Most of the crypto chips are broadly utilized in WN application to...     

Efficient impulse noise removal using hybrid neuro-fuzzy filter with optimized intelligent water drop technique

Impulse noise (IN) affects the digital image, during transmission, digital storage, and image acquisition. IN removal from an image is necessary as it retains the quality of the image. This work concentrates on the IN. A neuro-fuzzy (NF) system based on a fuzzy technique which is trained by a learning algorithm derived from neural network theory was implemented for the removal of noise. A NF network for noise filtering in grayscale images that combines two NF filters with a postprocessor to produce the output was presented. However, Sugeno-type is not intuitive technique and it also less accurate. To overcome these problems, a hybrid NF filter with optimized intelligent water drop (IWD) technique is introduced, where hybridized Sugeno–Mamdani-based fuzzy interference system is implemented in both the NF filters to obtain more efficient noise removal system. To improve the accuracy of the assignment of membership values to each input pixels, the optimized IWD technique is utilized, as the choice of membership function decides the efficiency of the noise removal in the images. Here, Fuzzy rules have been used to obtain the filtered output. The Hybrid method maintains the accuracy of the Sugeno model and also the interpretable capability of the Mamdani model. This method is robust against the IN and it is flexible, efficient, and accurate than existing filtering method in both noise attenuation and detail preservation and it has a great scope for better real-time applications.     

Double Charge Transfer Dominates in Carrier Localization in Low Bandgap Sites of Heterogeneous Lead Halide Perovskites

Heterogeneous organic-inorganic halide perovskites possess inherent non-uniformities in bandgap that are sometimes engineered and exploited on purpose, like in quasi-2D perovskites. In these systems, charge carrier and excitation energy migration to lower-bandgap sites are key processes governing luminescence. The question, which of them dominates in particular materials and under specific experimental conditions, still remains unanswered, especially when charge carriers comprise excitons. In this study transient absorption (TA) and transient photoluminescence (PL) techniques are combined to address the excited state dynamics in quasi-2D and other heterogeneous perovskite structures in broad temperature range, from room temperature down to 15 K. The data provide clear evidence that charge carrier transfer rather than energy migration dominates in heterogeneous quasi-2D perovskite films.     

Smile intensity recognition in real time videos: fuzzy system approach

Multimedia Tools and Applications - Facial emotion is a significant way of understanding or interpreting one’s inner thoughts. Real time video at any instant exhibits the emotion which serves...     

Fabrication and erosion studies of C-SiC composite Jet Vanes in solid rocket motor exhaust

C-SiC composite Jet-Vanes were fabricated using liquid silicon infiltration and tested in a plume of aluminum based solid propellant to study erosion resistance. The Jet-Vanes showed excellent resistance to thermo-oxidative erosion; average linear and mass erosion rates were 1 mm/s and 5 g/s, respectively. Morphology of the eroded surfaces suggests that alumina particles in the plume hit the leading edge of the Jet-Vane, damage it and some material is eroded away. Residual silicon melts and reacts with oxygen to form silica which in turn reacts with SiC matrix. The matrix of SiC, silicon and un-reacted carbon is loosened and erode by high shear forces. Once carbon fibers get exposed directly to the plume, these may be both eroded and oxidized.     

Kinetic separation of cobalt from zirconium by cation exchange process

Zirconium-tin alloys are used as pressure tubes in Indian pressurized heavy water reactors (PHWRs). Used pressure tubes contain neutron activation products of the constituent elements. ⁶⁰Co is one of the long-lived radioisotopes of concern, for both radioactive waste management and recycling of pressure tubes. This article describes a facile cation exchange separation of Co(II) from Zr(IV) in HCl medium. Co(II) could be preferentially sorbed on the gel resin by utilizing its faster kinetics. Higher flow rates and shallow resin bed were the key steps, which prevented the loading of Zr(IV) on the resin phase.     

Structure,solubility and bioactivity in TiO2-doped phosphate-based bioglasses and glass–ceramics

Phosphate-based bioactive glasses in addition to TiO₂ (x = 0–2.5 mol%) were prepared by melt quenching technique. Glass–ceramics were prepared by controlled two-step thermal treatment of the as-prepared phosphate bioglasses at their nucleation and crystallisation temperatures. X-ray diffraction (XRD) analysis was used to explore the amorphous and crystalline nature of materials. The presence of calcium phosphate crystals like NaPO₃, α, β-Ca₂P₂O₇, α,β-Ca₃(PO₄)₂ and Na₅Ti(PO₄)₃ plays a dominant role in glass–ceramics. The structural changes were analyzed by density and T_g measurements. The degradation process in deionised water (DIW) was observed by pH and weight loss measurements. It was interesting to note that the highest solubility phosphate glasses become stiffer to degradation with increasing TiO₂ content. Addition of TiO₂ leads to densify the glass structure and interconnect the cross-linkages in the network. Chemical durability of glass–ceramics in DIW purely depends on the formed crystalline as well as the residual glassy phases. The formation of a biologically active layer on the surface of glasses and glass–ceramics were investigated by in vitro studies through XRD analysis.