Electrodeposition and characterization of amorphous Cr-P alloys

The influence of plating variables and bath composition on electrodeposition of chromium-phosphorous alloy composition was investigated. The plating bath, prepared at a pH of approximately 1.25, consisted of a trivalent chromium source, sodium hypophosphite, ammonium sulphate, boric and formic acids, and sodium lauryl sulphate. Energy dispersive spectroscopy and Auger electron spectroscopy were utilized to evaluate alloy composition. These alloys were determined to be amorphous by X-ray diffraction. The influence of temperature, and bath ageing, and deposition time on deposit composition and structure and the deposition rate were also investigated.     

Passivation of pyrite due to surface treatment

Two samples of naturally occurring pyrite were treated with acetyl acetone, silanes, humic acids, lignin-NaOH mixture, and oxalic acid. The corrosion rate of pyrite was observed to decrease significantly due to the surface treatment by the chemicals used in this study. Surface characterization methods indicate that phenyl triacetoxy silane forms a passive coating a few Angstroms thick on the pyrite, thus preventing its dissolution in 1M H₂SO₄.     

The outlook of zeolite-Y hampered metal–ligand framework as heterogeneous catalysts: synthesis,spectral account and catalytic features

Zeolite-Y enslaved complexes were prepared by the Flexible ligand method. Synthesized materials were characterized by various spectral tools like powder X-ray diffraction, spectral studies (UV–Vis and FT-IR), chemical analysis (ICP-OES and elemental), scanning electron microscopy, AAS and ¹H-NMR techniques. Further, BET and thermogravimetric (TG) analysis were also done for characterization of surface area, pore volume, thermal behavior, and related parameters. Baeyer–Villiger oxidation of cyclohexanone was carried out over Zeolite-Y enslaved complexes using hydrogen peroxide (H₂O₂) as an oxidant. The performance of the heterogeneous system with the homogeneous system was compared to determine the protection effect of the zeolitic matrix over the active center on the catalytic properties. In addition, the effect of experimental variables (various solvents, amount of catalyst, the mole ratio of substrate and oxidant, temperature, and reaction time) was examined in order to get absolute reaction conditions. Under the optimized reaction conditions, [Fe(nbab)₂]-Y was found to be a potential candidate, achieving 70 % ?-caprolactone selectivity.     

Solubility enhancement of electrolyzed coal residues

Coal slurries were electrolyzed in acidic as well as basic electrolytes at different oxidizing potentials. The partially reacted coal residues were subjected to Soxhlet extraction with an equivolumetric mixture of benzene and ethanol for a period of 24 hours. The solvent-soluble organic part of coal was analyzed by GC-MS. Coal electrolyzed in acidic electrolytes became more accessible to extraction by the solvents used in the study. Electrolysis at 3.1 V vs. SCE (saturated calomel electrode) of a North Dakota lignite enhanced the solubility of coal in the benzene-ethanol mixture by a significant amount of 33%. Coal electrolysis in basic electrolytes at lower electrode potentials resulted in enhanced solubility of coal; however, at relatively large electrode potentials the yield of organic chemicals obtained by Soxhlet extraction declined.     

Supply management in assembly systems with random yield and random demand

In this paper, we consider an assembly system where a firm faces random demand for a finished product which is assembled using two critical components. The components are procured from the suppliers who, due to production yield losses, deliver a random fraction of the order quantity. We formulate the exact cost function where the decision variables are the target level of finished products to assemble, and the order quantity of the components from the suppliers. Since the exact cost function is analytically complex to solve, we introduce a modified cost function and derive bounds on the difference in the objective function values. Using the modified cost function, we determine the combined component ordering and production (assembly) decisions for the firm. The benefit of coordinating ordering and assembly decisions is numerically demonstrated by comparing the results with two heuristic policies commonly used in practice. In an extension to the model, we consider the case when the firm has the added option of ordering both the components in a set from a joint supplier. First, we consider the case when the joint supplier is reliable in delivery and obtain dominance conditions on the suppliers to be chosen. The maximum price a firm would be willing to pay to ensure reliable supply of components is determined. Later, we consider the uncertainty in the deliveries from the joint supplier and determine conditions under which there is no diversification, that is, either the individual suppliers are used, or the joint supplier is used, but never both.     

Characterization of semiconducting properties of naturally occurring polycrystalline FeS2 (pyrite)

Naturally occurring polycrystals obtained from Spain and Peru were found to be n-type semiconductors. Samples were characterized using an energy dispersive X-ray analyser and the impurity content of pyrite was estimated. Resistivity and Hall mobility as a function of temperature were measured. A lattice scattering mechanism is found to be operative for the Spanish pyrite sample. Results on optical absorption studies and the crystal structure are also included.     

ADYTIA: Adaptive and Dynamic TCP Interface Architecture for heterogeneous networks

Due to the widespread popularity and usage of Internet of things (IoT)‐enabled devices, there is an exponential increase in the data traffic generated from these IoT devices. Most of these devices communicate with each other using heterogeneous links having constraints such as latency, throughput, and interference from concurrent transmissions. This results in an extra burden on the underlying communication infrastructure to manage the traffic within these constraints between source and destination. However, most of the existing applications use different Transmission Control Protocol (TCP) variants for traffic management between these devices and are dependent on the stage of the sender, irrespective of the application types and link characteristics. Each operating system (OS) has different TCP variant for all applications, irrespective of path characteristics. Hence, a single TCP variant cannot select the best suitable link, which results in degradation in throughput compared to the existing default. Moreover, it cannot use the full capacity of the available link for different applications and network links, especially in heterogeneous network such as IoT. To cope up with these challenges, in this paper, we propose an Adaptive and Dynamic TCP Interface Architecture (ADYTIA). ADYTIA allows the usage of different TCP variants based on application and link characteristics, irrespective of the physical links of the entire path. It allows the usage of different TCP variants based on their design principle across heterogeneous technologies, platforms, and applications. ADYTIA is implemented on NS‐2 and Linux kernel for real testbed experiments. Its ability to select the best suitable TCP variant results in 20% to 80% improvement in throughput compared with the existing default and single TCP variant on Linux and Windows.