Mathematical approach to compute the molecular composition of hydrothermal liquefaction-derived renewable crude oil

Hydrothermal liquefaction (HTL), a thermo-chemical conversion process, uses water as a reaction medium at elevated pressure and temperature, to convert biomass to renewable liquid fuel and recovers fertilizer-rich water. To assess the techno-economic screening of HTL oils from various feedstock, it is crucial to have information on molecular composition of the feed and products. There are limitations of existing analytical methods to identify and quantify all the molecules present in the bio-fuel. Therefore, there is a need to find alternate ways to quantify the molecular composition of feed and expected products. The modeling work on bio-oil is developed and validated on mathematical approach using simple analytical results like CHNO along with structural analysis of oil like Fourier-transform infrared, nuclear magnetic resonance analysis for HTL derived oil from microalgae. This mathematical framework is further extended to predict the molecular composition of oil obtained from HTL of feedstocks like mixed plastic waste, sludge, and so on. A multi-dimensional molecular matrix is developed based on the distributions of side chains, aromatic rings, and olefinic carbon on top of core molecules. The parameters of the distributions are estimated computationally using global optimization algorithm (genetic algorithm) and local optimization algorithm to predict a mixture composition that matches closely with bulk properties of the product.     

Fabrication of robust self-cleaning superhydrophobic coating by deposition of polymer layer on candle soot surface

A facile and inexpensive way have been developed to fabricate robust self-cleaning superhydrophobic coating by depositing polymer layer on candle soot (CS) surface using dip coating method. The stability and robustness of the CS deposited superhydrophobic surface is much weaker due to weak interaction and nonchemical bonding with the substrate. We introduced a thin layer of polystyrene, polyethylene, polypropylene (PP), and polyvinylidene fluoride on CS surface in order to improve its mechanical properties. The fabricated surfaces with the use of respective polymers exhibited water contact angles of nearly 170, 174, 175, and 171° with sliding angles of 2, 1, 1, and 3°, respectively. Although, all the polymers used in this work exhibited excellent superhydrophobic and self-cleaning surface property, we found that the PP deposited CS surface exhibit better stability against water jet hitting and water drop impact tests. The PP deposited CS surface almost maintained their surface properties even after 50 cycles of sandpaper abrasion and 20 cycles of adhesive tape peeling tests. The mechanical durability tests confirmed that PP is a better polymer to improve the long-term durability of CS surface. Therefore, this simple, time saving, and inexpensive method for fabricating superhydrophobic coating can be used for potential industrial application.     

Bromination of p-Bromophenol in the Presence of Pyridine

The role of pyridine (Py) in the bromination of p-bromophenol (ArH) in CCl₄ has been investigated. At constant concentrations of ArH and Br₂, the rate of disappearance of Br₂ increases to reach a limiting value as the concentration of Py is increased. The mechanism suggested to account for the rate expression, Rate = constant [ArH] [Br₂]_T[Py]_T, obtained from the initial rate studies, involves the interaction between ArH and the brominating species Py. Br₂, in the rate determining step. Py acts as a catalyst probably by virtue of its ability to polarise the Br-Br bond.     

Nitrogen dissolution in alkali-barium-metaphosphate melts

Phosphorus oxynitride glasses were prepared by remelting 30R₂O-20BaO-50P₂O₅, (R=Li, Na or K) glasses in anhydrous ammonia. The nitrogen content of these metaphosphate melts decreased with increasing size of the alkali ion. The dissolution rate in water and thermal expansion coefficient of the base glasses increased with increasing alkali ion size. The dissolution rate of the oxynitride glasses was lower than that of the base glasses but was essentially independent of the alkali ion. The thermal expansion coefficient of the oxynitride glasses increased with increasing alkali size as observed in other glasses.     

Study on behaviour of angle shear connector in steel-concrete composite structures

In this study an experimental study of the behaviour of angle shear connector is presented. Six push-out tests on angle shear connector with two varied length angles were investigated. The shear resistance and shear stiffness with angles embedded in a normal concrete strength were predicted. The experimental results were also compared with standard design code formula and recommended values of design codes. The available experimental procedure for the determination of the shear force-slip behaviour of shear connector under static loading was adopted.     

Temperature and torque determination in brake drums

Simulation of temperature distribution in a brake drum and determination of drum brake torque has been carried out using finite element methods. The simulated temperature distribution and the brake torque determined were compared with observations carried out using an inertia dynamometer with a data-logging system. There is good agreement between the predicted temperature distribution and the brake torque determined with the test results on the dynamometer.     

The formation of elevated barrier height Schottky diodes to inp and In0.53Ga0.47as using thin,excimer laser-deposited Cd interlayers

Much recent attention has been paid to elevating the barrier height of contacts to InP and In_0.53Ga_{0. 47}As via the formation of a thin, intermediate layer between the semicon-ductor and a conventionally deposited, highly conductive contact layer. Here, we report on the use of thin (～200Å) excimer laser photodeposited Cd as an interlayer between these semiconductors and Au overlayers in order to raise the barrier height of the re-sulting diodes. Current-voltage measurements of ideal Schottky diodes fabricated using this process yield barrier heights of 0.70 eV and 0.55 eV to InP and In_0.53Ga_{0. 47}As, re-spectively. The photodeposition process has been integrated with conventional clean room processing resulting in Au/Cd/In_0.53Ga_{0. 47}As transistors with high transconductances (～200 mS/mm) and operating frequencies (f _max ～ 30 GHz). X-ray photoelectron spec-troscopy of thin Cd photodeposits on InP shows that the process produces an interfacial (～10Å thick) Cd-InP reaction zone covered by metallic Cd.     

Description and evaluation of the FAST-Net smart pixel-basedoptical interconnection prototype

The design, packaging approach, and experimental evaluation of the free-space accelerator for switching terabit networks (FAST-Net) smart-pixel-based optical interconnection prototype are described. FAST-Net is a high-throughput data-switching concept that uses a reflective optical system to globally interconnect a multichip array of smart pixel devices. The three-dimensional optical system links each chip directly to every other with a dedicated bidirectional parallel data path. in the experiments, several prototype smart-pixel devices were packaged on a common multichip module (MCM) with interchip registration accuracies of 5-10 μm. The smart-pixel arrays (SPAs) consist of clusters of oxide-confined vertical-cavity surface-emitting lasers and photodetectors that are solder bump-bonded to Si integrated circuits. The optoelectronic elements are arranged within each cluster on a checkerboard pattern with 125-μm pitch. The experimental global optical interconnection module consists of a mirror and lens array that are precisely aligned to achieve the required interchip parallel connections between up to 16 SPAs. Five prototype SPAs were placed on the MCM to allow the evaluation of a variety of interchip links. Measurements verified the global link pattern across several devices on the MCM with high optical resolution and registration. No crosstalk between adjacent channels was observed after alignment. The I/O density and efficiency results suggest that a multi-terabit switch module that incorporates global optical interconnection to overcome conventional interconnection bottlenecks is feasible     

Large area (9 × 9 cm) electrostatically sprayed nanocrystalline zincite thin films for hydrogen production application

Synthesis of single phase nanocrystalline zinc ferrite (zincite) thin films that provides high surface area for active redox reactions is reported. Electrostatic spray method is employed for obtaining these ferrite films onto a stainless steel substrate of 9 × 9 cm² area using zinc acetate and iron nitrate precursor solutions, mixed in 1:1.5 proportions in triply-distilled water. Single zinc ferrite phase in films, confirmed from the X-ray diffraction pattern, reveals the aggregation of several nanometer-sized spherical grains. About 4 nm average roughness is obtained from the 3D AFM image. Zinc ferrite film deposited onto a glass substrate shows both direct (2.96 eV) and indirect (1.92 eV) band gap energies. Hydrophilic behavior that might facilitate easy reaction kinetics in a water splitting process is noticed. Finally, 450 mL/h hydrogen production rate is confirmed when zinc ferrite film electrode was used as an anode in presence of Pt mesh as a cathode.