Production and characterization of AA6061–B4C stir cast composite

This work focuses on the fabrication of aluminum (6061-T6) matrix composites (AMCs) reinforced with various weight percentage of B₄C particulates by modified stir casting route. The wettability of B₄C particles in the matrix has been improved by adding K₂TiF₆ flux into the melt. The microstructure and mechanical properties of the fabricated AMCs are analyzed. The optical microstructure and scanning electron microscope (SEM) images reveal the homogeneous dispersion of B₄C particles in the matrix. The reinforcement dispersion has also been identified with X-ray diffraction (XRD). The mechanical properties like hardness and tensile strength have improved with the increase in weight percentage of B₄C particulates in the aluminum matrix.     

A Review of Sustainable Bio-Based Insulation Materials for Energy-Efficient Buildings

The surge towards a sustainable future in the construction industry requires the use of bio-based insulation materials as an alternative to conventional ones for improving energy efficiency in structures. In this article, the features of bio-based insulation materials, including their thermal conductivities, moisture buffering value, fire performance, and life cycle evaluations are examined. It is clear from the review that pre- and post-treatment of the bio-based materials used for insulation materials optimize their properties. The life cycle analysis reveals a significant reduction in global warming potential (GWP) compared to conventional foams. In addition, it is envisaged that producing bio-based insulation materials on a larger scale will further decrease the net GWP. The article, therefore, proposes the implementation of policies that will promote the commercialization of bio-based insulation materials.     

Mechanosynthesis of Triazolyl-bis(indolyl)methane Pharmacophores via Gold Catalysis: A Prelude to Their Molecular Electronic Properties and Biological Potency

Chemical structures possessing both 1,2,3-triazole and bis(indolyl)methane fragments gained considerable interest in drug synthesis owing to their established biological efficacies. However, 1,2,3-triazoles linked at the bridging position of bis(indolyl)methane is a logical and unexplored design approach. In this regard, nine new triazolyl-bis(indolyl)methane conjugates under AuCl catalyzed ball-milling conditions were accomplished. Comparative evaluation on absorptive and emissive properties of the synthesized dyads were also analyzed. To unravel the influence of different peripheral substituents on the electronic structure and π-orbital properties, theoretical investigations were performed. Screening of molecules for free radical scavenging, anti-inflammatory and antidiabetic showed comparable potency against reference drugs. In particular, compounds 7 h , 7 d and 7 a displayed good efficiency of α-amylase inhibition. The DNA gyrase inhibitory potential of all compounds were assessed in silico which revealed high binding affinity (ΔG=−8.99 Kcal/mol) for 7 i followed by 7 h (ΔG=−7.80 Kcal/mol) with the targeted protein.     

Si diffusion in GaAs

Theoretical studies are carried out to ascertain the dominant mechanism of Si diffusion in GaAs. Lattice dynamical model calculations have shown that the most probable diffusion mechanism is through a single vacancy even though several experiments cannot fix the mechanism as substitutional, substitutional-interstitial pair or neutral defect pair.     

Analysis of bovine-derived demineralized bone extracts

Demineralized bone factors are capable of stimulating bone regeneration through an osteoinductive mechanism and thus it has been recognized as a good bone graft. In this study, a kind of demineralized bone extracts (DBX) derived from bovine tibia by a chemical route. The extracts thus obtained were analyzed for their bio-chemical and physical properties using various techniques and results provided quite interesting insights into the demineralization process. There is no significant evidence of mineral phase associated with the connective tissue detected during chemical as well as physical testing, indicating the formation of DBX. This kind of bone extracts may used as a bone graft material and as a substrate for the growth of biomimetic apatites.     

Performance,emission and combustion studies of a DI diesel engine using Distilled Tyre pyrolysis oil-diesel blends

Increase in energy demand, stringent emission norms and depletion of oil resources led the researchers to find alternative fuels for internal combustion engines. Many alternate fuels like Alcohols, Biodiesel, LPG, CNG etc have been already commercialized in the transport sector. In this context, pyrolysis of solid waste is currently receiving renewed interest. The disposal of waste tyres can be simplified to some extent by pyrolysis. The properties of the Tyre pyrolysis oil (TPO) derived from waste automobile tyres were analyzed and compared with the petroleum products and found that it can also be used as a fuel for compression ignition engine. However, the crude TPO has a higher viscosity and sulphur content. The crude TPO was desulphurised and then distilled through vacuum distillation. In the present work, DTPO-diesel blends were used as an alternate fuel in a diesel engine without any engine modification. This paper presents the studies on the performance, emission and combustion characteristics of a single cylinder four stroke air cooled DI diesel engine running with the Distilled Tyre pyrolysis oil (DTPO).     

Classifying inventory using an artificial neural network approach

This paper presents artificial neural networks (ANNs) for ABC classification of stock keeping units (SKUs) in a pharmaceutical company. Two learning methods were utilized in the ANNs, namely back propagation (BP) and genetic algorithms (GA). The reliability of the models was tested by comparing their classification ability with two data sets (a hold-out sample and an external data set). Furthermore, the ANN models were compared with the multiple discriminate analysis (MDA) technique. The results showed that both ANN models had higher predictive accuracy than MDA. The results also indicate that there was no significant difference between the two learning methods used to develop the ANN.     

Synthesis and characterization of new soluble multisite phase transfer catalysts and their catalysis in free radical polymerization of methyl methacrylate aided by ultrasound—A kinetic study

Four different soluble phase transfer catalysts (PTCs) containing single, di, tri, and tetra active sites have been prepared and proved by FT-IR, ¹H NMR, ¹³C NMR, mass, elemental analysis, and conductivity measurement. The presence of the number of active sites in each catalyst was also been confirmed by determining their rate of polymerization of methyl methacrylate (MMA) using potassium peroxydisulfate (PDS) as a water soluble initiator in biphase medium. The comparative study reveals that the R_p of MMA determined in the presence of PTC combined with ultrasound has shown twofold enhancement in the activity than PTC alone. The observed order of activity was found to be of single-site < di-site < tri-site < tetra-site. Further, the thorough kinetic study of free radical polymerization of MMA has been investigated using superior tetra site viz., HBTAMPDTC and by varying the experimental parameters such as [MMA], [K₂S₂O₈], [MPTC], and the temperature. Based on the observed kinetic results and activation parameters, a suitable mechanism was proposed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of Traverse Speed on Microstructure and Microhardness of Cu/B4C Surface Composite Produced by Friction Stir Processing

Friction stir processing (FSP) has evolved as a potential candidate to fabricate surface composites. This paper investigates the influence of traverse speed on microstructure and microhardness of Cu/B₄C surface composite fabricated using FSP. The traverse speed was varied from 20 to 60 in steps of 20 mm/min. The tool rotational speed, axial force and groove width were kept constant. Optical microscopy and scanning electron microscopy were employed to study the microstructure of the fabricated surface composites. The results indicated that the traverse speed significantly influenced the area of the surface composite and distribution of B₄C particles. The area of the surface composite was found to bear an inversely proportional relationship to traverse speed. Lower traverse speed exhibited homogenous distribution of B₄C particles while higher traverse speed caused poor distribution of B₄C particles in the surface composite.     

On the specific heat of Al-Si and Al-Ge alloys—A simulation study

The large variation in specific heats with concentration between temperatures 50 K and 200 K for Al-Si and Al-Ge alloys are analysed in detail by lattice dynamical and Monte Carlo approaches. The large deviation from linearity at low temperatures does not seem to be due to the Debye’s low temperature contribution. It is shown that an anharmonic vibration in the above solid solutions, particularly at 200 K, is the cause for the small variation in the specific heat.