An evaluation of fuelwood properties of some Aravally mountain tree and shrub species of Western India

The study analyses the fuelwood characteristics of 26 trees including shrub species from the dry deciduous forest in Aravally region, Rajasthan, Western India was carried out to explore trees with potential for fuelwood production. Fuelwood value index (FVI) based on the properties of calorific value, wood density and ash. Calorific value was ranged between 18.54 ± 0.04 and 27.44 ± 0.09 KJ g⁻¹ in Jatropha curcus and Wrightia tinctoria respectively. Wood density varied from 0.538 ± 0.01 to 0.966 ± 0.07 g/cm³ in J. curcus and Acacia nilotica. Same way ash and moisture content was highest in J. curcus (3.38 ± 0.19%) and Sterculia urens (70.28 ± 7.52%) and lowest in Miliusa tomentosa (0.85 ± 0.06%) and Azadirachta indica (30.7 ± 10.02%) respectively. On the basis, of the 26 species analyzed, M. tomentosa has the highest FVI, followed by Lannea coromandelica, Acacia leucophloea, Madhuca indica, A. nilotica, W. tinctoria, Butea monosperma, Zizyphus nummularia, S. urens, Boswellia serrata, A. indica, Grewia tenax, Syzygium cuminii, Tectona grandis and Dalbergia sissoo were shown to have promising fuelwood production.     

Influence of Au Photodeposition and Doping in CdS Nanorods: Optical and Photocatalytic Study

Au-modified CdS nanorods (100–200 nm × 5–10 nm) are synthesized via two different techniques, namely photodeposition and doping. The prepared samples are characterized by x-ray powder diffraction, transmission electron microscopy (TEM), and UV–vis and fluorescence spectroscopy. X-ray diffraction study confirmed the hexagonal phase of bare and Au-CdS samples, whereas, 5 wt% Au³⁺ doping into CdS resulted in a slight distortion in the crystal structure toward higher degree side. TEM images revealed the fine distribution of Au nanodeposits of size in the range of 2.5–4.5 nm on to the CdS surface in the photodeposited sample. The optical spectrum shows a significant red-shift in absorption onset (485 nm → 515 nm) and band-edge emission (505 nm → 512 nm) of CdS nanorods with the replacement of certain Cd²⁺ ions with Au³⁺. The influence of Au photodeposition and doping in CdS nanorods was comparatively tested by photooxidation of RhB (50 ppm) dye aqueous solution under direct sunlight irradiation (35–40 mWcm^?2). Our results point out that 5 wt% Au³⁺ doping into CdS nanorods remarkably improved its activity and stability due to homogeneous dispersion of charge throughout the crystal, quick Fermi level equilibration, and an improvement in ionic bond formation.     

Metal hollow sphere electrocatalysts

Metal micro-/nano hollow spheres have been widely applied in numerous fields during the last decade. This review will only focus on the synthetic strategies to synthesize hollow spherical structures in the enhancement of their electrocatalytic activity, especially the metal hollow spherical materials. We present a comprehensive overview of synthetic strategies for metal hollow spherical structures which have been approached specifically in electrochemical reactions. These synthetic methods are mainly categorized as hard templates, soft templates, sacrificial templates and without templates. The review further includes electrocatalytic approaches of hollow spherical metals in different electrochemical processes, especially the methanol electro-oxidation reaction for methanol fuel cell application and hydrogen and oxygen evolution reactions in water electrolyzer, as metal hollow spherical materials are especially applied in these specific reactions.     

Synthesis of magnetic nanocomposite microparticles for binding of chlorinated organics in contaminated water sources

In this work, the development of novel magnetic nanocomposite microparticles (MNMs) via free radical polymerization for their application in the remediation of contaminated water is presented. Acrylated plant-based polyphenols, curcumin multiacrylate (CMA) and quercetin multiacrylate (QMA), were incorporated as functional monomers to create high affinity binding sites for the capture of polychlorinated biphenyls (PCBs), as a model pollutant. The MNMs were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, dynamic light scattering, and UV–visible spectroscopy. The affinity of these novel materials for PCB 126 was evaluated and fitted to the nonlinear Langmuir model to determine binding affinities (K_D). The results suggest the presence of the polyphenolic moieties enhances the binding affinity for PCB 126, with K_D values comparable to that of antibodies. This demonstrates that these nanocomposite materials have promising potential as environmental remediation adsorbents for harmful contaminants.     

Simulation of population balance model-based particulate processes via parallel and distributed computing

Population Balance Models (PBMs), a class of integro partial differential equations, are utilized for simulating dynamics of numerous particulate systems. PBMs describe the time evolutions and distributions of many particulate processes and their efficient and quick simulation are critical for enhanced process control and optimization, especially for real-time applications. However, their intensive computational resource requirement is largely a prohibitive factor in the utility of PBMs for control and optimization. This paper describes how distributed computing systems may be leveraged to execute PBM-based simulations thus achieving time savings, using MATLAB's Distributed Computing Toolbox. A parallel computing algorithm was developed for a three dimensional and four dimensional population balance model with built-in constructs such as SPMD that ran efficiently on a cluster of two quad-core machines linked via a gigabit ethernet cable. Speedup of 6.2 and 5.7 times were achieved with 8 workers, over an un-parallelized code, for a 3 and 4 dimensional PBM respectively. Evaluations on work efficiency and scalability further affirm the algorithms’ respectable performance on larger clusters despite significant memory transfer overheads.     

Nanostructured Zn-Fe2O3 thin film modified by Fe-TiO2 for photoelectrochemical generation of hydrogen

Nanostructured semiconductor thin films of Zn-Fe₂O₃ modified with underlying layer of Fe-TiO₂ have been synthesized and studied as photoelectrode in photoelectrochemical (PEC) cell for generation of hydrogen through water splitting. The Zn-Fe₂O₃ thin film photoelectrodes were designed for best performance by tailoring thickness of the Fe-TiO₂ film. A maximum photocurrent density of 748 μA/cm² at 0.95 V/SCE and solar to hydrogen conversion efficiency of 0.47% was observed for 0.89 μm thick modified photoelectrode in 1 M NaOH as electrolyte and under 1.5 AM solar simulator. To analyse the PEC results the films were characterized for various physical and semiconducting properties using XRD, SEM, EDX and UV–Visible spectrophotometer. Zn-Fe₂O₃ thin films modified with Fe-TiO₂ exhibited improved visible light absorption. A noticeable change in surface morphology of the modified Zn-Fe₂O₃ film was observed as compared to the pristine Zn-Fe₂O₃ film. Flatband potential values calculated from Mott–Schottky curves also supported the PEC response.     

An isogeometric independent coefficients (IGA-IC) reduced order method for accurate and efficient transient nonlinear heat conduction analysis

This article develops an isogeometric independent coefficients (IGA-IC) reduced order method for transient nonlinear heat conduction analysis. Herein, we first exactly represent the geometric model via isogeometric analysis (IGA), and therein provide an accurate solution for the semi-discretized equations. Next, our proposed GSSSS-1 time-stepping framework is employed to solve the transient nonlinear temperature in space and time domains. We advance our independent coefficients (IC) reduced order method to efficiently solve IGA-based transient nonlinear heat conduction problems. We extend the IC method to significantly reduce the original full IGA-discretized formulations and calculate the reduced equilibrium formulations in each Newton–Raphson iteration. Thereby, hugely improving the efficiency and guaranteeing the accuracy simultaneously. Illustrative numerical examples validate this proposed IGA-IC method is reliable, accurate, and efficient; especially, the larger the scale of the problem, the more advantages the proposed IGA-IC will inherit.     

Energy efficient control of a BTX dividing-wall column

Dividing-wall column (DWC) is considered nowadays the new champion in distillation, as it can bring substantial reduction in the capital invested as well as savings in the operating costs. This work presents the simulation results of energy efficient control and dynamics of a dividing-wall column (DWC). In order to allow a fair comparison of the results with previously published references, the case-study considered here is the industrially relevant ternary separation of the mixture benzene-toluene-xylene (BTX) in a DWC. Rigorous simulations were carried out in Aspen Plus and Aspen Dynamics. Several conventional control structures based on PID control loops (DB/LSV, DV/LSB, LB/DSV, LV/DSB) were used as a control basis. These control structures were enhanced by adding an extra loop controlling the heavy component composition in the top of the prefractionator, by using the liquid split as an additional manipulated variable, thus implicitly achieving minimization of energy requirements. The results of the dynamic simulations show relatively short settling times and low overshooting especially for the DB/LSV and LB/DSV control structures. Moreover, the energy efficient control proposed in this work allows the operation of DWC with minimum energy requirements or maximum purity of products.