Removal of Pb(II) ions from aqueous solution by adsorption using bael leaves (Aegle marmelos)

Biosorption of Pb(II) on bael leaves (Aegle marmelos) was investigated for the removal of Pb(II) from aqueous solution using different doses of adsorbent, initial pH, and contact time. The maximum Pb loading capacity of the bael leaves was 104 mg g^?1 at 50 mg L^?1 initial Pb(II) concentration at pH 5.1. SEM and FT-IR studies indicated that the adsorption of Pb(II) occurs inside the wall of the hollow tubes present in the bael leaves and carboxylic acid, thioester and sulphonamide groups are involved in the process. The sorption process was best described by pseudo second order kinetics. Among Freundlich and Langmuir isotherms, the latter had a better fit with the experimental data. The activation energy E_a confirmed that the nature of adsorption was physisorption. Bael leaves can selectively remove Pb(II) in the presence of other metal ions. This was demonstrated by removing Pb from the effluent of exhausted batteries.     

Improved tire tread compounds using functionalized styrene butadiene rubber-silica filler/hybrid filler systems

Automotive industry is currently looking for an eco-friendly tire with low rolling resistance coefficient (RRc), better traction, wear resistance, and fatigue properties. Presently, solution styrene-butadiene rubber (SSBR)-silica systems are pursued for balancing between traction and RRc. However, the interaction between SSBR and silica is not enough to give satisfactory results. Functionalized-SSBR (FSSBR) leads to better rubber-silica interaction due to introduction of polar groups in the polymer chain. The present study investigates the influence of FSSBR, highly dispersible (HD) silica, and its hybrid filler systems with organically modified nanoclay (ONC) and exfoliated graphene nanoplatelet (xGnP). Both M_H, and Δtorque were higher for the FSSBR-HD silica compound (S1) with the lowest change in storage modulus (∆G') value, due to higher polymer-filler interaction. S1 exhibited 16% ice traction and 12% wet traction improvement with 29% lower rolling resistance over SSBR-silica compound. S1 showed the best wet traction rating and wear resistance. Replacing small portion of silica by ONC and xGnP improved the properties further. At 5 phr of nanofiller, TEM images revealed well-dispersed nanofillers in the FSSBR matrix. The xGnP compound showed the least crack growth. For both the cases, abradability decreased with higher nanofiller amount, due to better reinforcement of the rubber.     

Hybrid material integration in silicon photonic integrated circuits

Hybrid integration ofⅢ-Ⅴand ferroelectric materials is being broadly adopted to enhance functionalities in silicon photonic integrated circuits(PICs).Bonding and transfer printing have been the popular approaches for integration of III–V gain media with silicon PICs.Similar approaches are also being considered for ferroelectrics to enable larger RF modulation bandwidths,higher linearity,lower optical loss integrated optical modulators on chip.In this paper,we review existing integration strategies ofⅢ-Ⅴmaterials and present a route towards hybrid integration of bothⅢ-Ⅴand ferroelectrics on the same chip.We show that adiabatic transformation of the optical mode between hybrid ferroelectric and silicon sections enables efficient transfer of optical modal energies for maximum overlap of the optical mode with the ferroelectric media,similar to approaches adopted to maximize optical overlap with the gain section,thereby reducing lasing thresholds for hybridⅢ-Ⅴintegration with silicon PICs.Preliminary designs are presented to enable a foundry compatible hybrid integration route of diverse functionalities on silicon PICs.     

Study of reinforcement mechanism and structural elucidation of expanded graphite-carbon black hybrid filler-SBR nanocomposites through comprehensive analysis of mechanical properties and small angle X-ray data

Use of hybrid fillers as a reinforcing agent for polymers is found to be critical step toward developing a high-performance composite material. However, limited know-how on the nature of interaction of the hybrid fillers with the polymer chains resulted in a major impediment toward large-scale transmissibility of such a technology. Herein, we report about a strategy, wherein the polymer composite (free of curatives), comprising of hybrid filler and its gel was leveraged to effectively understand the physics involved toward reinforcement. Styrene-butadiene random copolymer as the matrix, and combination of expanded graphite and carbon black (N220) as the model hybrid filler were selected. The hybrid filler containing composite (SG22) demonstrated significant improvement in terms of the physico-mechanical properties such as tensile strength, modulus and so forth compared to the neat carbon black-filled system (S22). Stress-relaxation studies indicated that SG22 registered minimal decay in the force with time compared to S22. SG22 demonstrated a gel fraction of 68 ± 1% while 56 ± 1% was noted for S22. Further, rheometric studies like strain sweep, frequency sweep, complex viscosity of the gel fragments indicated the formation of fractal network of the hybrid fillers inside the polymer matrix. Small angle X-ray studies corroborated the crucial role played by the expanded graphite sheets in determining the microstructure of the composite owing to their lubrication effect and segregation of carbon black agglomerates by cutting through their sharp edges resulting in a well-distributed filler network.     

Design and implementation of an elastic processor with hyperthreading technology and virtualization for elastic server models

The Journal of Supercomputing - The server models functioning in the industry are required to be more elastic in nature. They are constantly scaling-up and scaling-down on required computation...     

Full Gamut Wall Tunability from Persistent Micelle Templates via Ex Situ Hydrolysis

The predictive self‐assembly of tunable nanostructures is of great utility for broad nanomaterial investigations and applications. The use of equilibrium‐based approaches however prevents independent feature size control. Kinetic‐controlled methods such as persistent micelle templates (PMTs) overcome this limitation and maintain constant pore size by imposing a large thermodynamic barrier to chain exchange. Thus, the wall thickness is independently adjusted via addition of material precursors to PMTs. Prior PMT demonstrations added water‐reactive material precursors directly to aqueous micelle solutions. That approach depletes the thermodynamic barrier to chain exchange and thus limits the amount of material added under PMT‐control. Here, an ex situ hydrolysis method is developed for TiO₂ that mitigates this depletion of water and nearly decouples materials chemistry from micelle control. This enables the widest reported PMT range (M:T = 1.6–4.0), spanning the gamut from sparse walls to nearly isolated pores with ≈2 Å precision adjustment. This high‐resolution nanomaterial series exhibits monotonic trends where PMT confinement within increasing wall‐thickness leads to larger crystallites and an increasing extent of lithiation, reaching Li_0.66TiO₂. The increasing extent of lithiation with increasing anatase crystallite dimensions is attributed to the size‐dependent strain mismatch of anatase and bronze polymorph mixtures.     

Determination of the interfacial heat transfer coefficient in a metal-metal system solving the inverse heat conduction problem

Simulation of several industrial processes involving solidification of metals requires characterization of heat transfer coefficient at the solidifying metal/metal-substrate interface. In the present investigation an attempt has been made to estimate this heat transfer coefficient, h_c, using simulated experiments in which the heat transfer from a heated stainless steel block (simulating solidifying metal) to a water cooled copper block (simulating metal-substrate) is monitored by continuously recording temperatures at a few internal locations both within the metal block and the substrate block. The problem of determining the interfacial heat transfer coefficient is recognized to be an inverse heat conduction problem (IHCP). A numerical method is employed to solve IHCP and to determine the h_c from the transient history of temperatures at a few locations. The effect of the physical nature of the interface, as well as the cooling conditions prevailing at the outer surface of the substrate on h_c is examined and discussed. While the physical nature of the interface, i.e. roughness on the metal as well as the substrate surfaces, has a significant effect on h_c, the cooling conditions have only a marginal effect. The h_c in the present investigation remains more or less time invariant.     

Comparison of neuronal response patterns in the external and central nuclei of inferior colliculus during ethanol administration and ethanol withdrawal

It is known that murine macrophages produce nitric oxide (NO) when stimulated with lipopolysaccharide (LPS) or interferon-gamma (IFN-gamma), and NO mediates the tumoricidal activity of activated macrophages. The present study was designed to investigate whether the intercellular adhesion is necessary for activated rat alveolar macrophages to exert the full cytotoxic effects. Rat alveolar macrophages produced NO dose dependently in response to either LPS or IFN-gamma, and caused DNA fragmentation in rat type II pneumocytes transformed with SV40 (SV40T2). Chemically produced NO also caused the DNA fragmentation and viability loss in SV40T2, and both of them were inhibited by a NO radical scavenger. The cytotoxicity of activated macrophages was reduced by NG-monomethyl-L-arginine, a competitive nitric synthase inhibitor, and neither superoxide dismutase nor catalase modulated the cytotoxicity. Although alveolar macrophages stimulated with either LPS or IFN-gamma caused DNA fragmentation of SV40T2, only LPS increased the intercellular adherence between macrophages and SV40T2. The intercellular adhesion was reduced by both anti-CD18 and anti-CD11a. However, those antibodies did not affect the cytotoxicity of LPS-stimulated macrophages. These results clearly indicate that NO-mediated cytotoxicity is caused predominantly by diffusion of NO, and the beta 2 integrin-mediated intercellular adhesion does not play an important role, if any, in activated macrophage-mediated cytotoxic effects on SV40T2.