A conceptual framework for blockchain smart contract adoption to manage real estate deals in smart cities

Neural Computing and Applications - Blockchains-based smart contracts are disrupting the smart real estate sector of the smart cities. The current study explores the literature focused on...     

Current transport and capacitance-voltage characteristics of n-InSb/p-GaP prepared by flash evaporation and liquid phase epitaxy

In this paper, n-Type of InSb films were successfully fabricated on p-GaP monocrystalline substrates by both flash evaporation technique and liquid phase epitaxy to study some features of current transport in strained heterojunctions. The elemental composition of the prepared films was confirmed by energy dispersive X-ray (EDX) spectroscopy. The morphology of the films was characterized by scanning electron microscopy (SEM). The electrical properties of the n-InSb/p-GaP junctions prepared by flash evaporation and liquid phase epitaxy were investigated through capacitance-voltage and current-voltage measurements, performed under dark condition in the temperature range 300?C400 K. Due to misfit dislocations, the interface showed rectifying behavior. At low voltages, current in the forward direction was found to obey the diode equation and the conduction was controlled by a thermionic emission mechanism. For relatively higher voltages, conduction was dominated by a space-charge-limited conduction mechanism with single trap level. This is evidence of a depletion of the space charge region due to Fermi level pinning by surface states at the InSb/GaP interface. Junction parameters of the n-InSb/p-GaP like ideality factor and barrier height were obtained and variations were monitored as a function of temperatures. Also, an attempt to explore the governing current flow mechanism was made.     

Efficient synthesis of fatty monoglyceride sulfates from fatty acids and fatty acid methyl esters

An efficient high yield synthesis of fatty monoglyceride sulfates from fatty acids or fatty acid methyl esters, glycerine and chlorosulfuric acid in chloroform using stoichiometric amounts of reagents was developed. Sodium coco monoglyceride sulfate was prepared in 79% yield with 93% purity from coco fatty acids. Similarly, sodium palm kernel monoglyceride sulfate in 57% yield and sodium palm monoglyceride sulfate in 71% yield were obtained from palm kernel fatty acid methyl esters and palm fatty acids, respectively. This new synthetic method produced better quality products with higher active ingredients and improved yields without having to use such cost prohibitive, high purity, fatty acid monoglycerides, and it reduced the undesirable aqueous sodium sulfate by-product by 60% over a current commercial process. The product’s composition and purity were confirmed by cationic titration, infrared and C-13 NMR spectroscopy.     

Formation of Amorphous Telmisartan Polymeric Microparticles for Improvement of Physicochemical Characteristics

In order to improve solubility and dissolution rate of poorly aqueous soluble telmisartan, its amorphous polymeric microparticles with PVP K30 were prepared with or without aid of adsorbent (Aerosil200/Sylysia350) using spray-drying technique. The pure drug and formulations were evaluated for their morphology, particle size, aqueous solubility, and in vitro drug release. Solid state characterization of pure drug and microparticles was carried out by Fourier transform infrared spectroscopy (FTIR), x-ray powder diffraction (XRPD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). FTIR indicated hydrogen bonding interaction with an absence of any other chemical interaction between drug and excipient. The results of DSC and XRPD revealed transformation of crystalline drug to amorphous form which was confirmed by SEM. Significant solubility and dissolution enhancement was observed for all polymeric microparticles over pure drug and spray-dried pure drug. This enhancement was attributed to the wetting effect of polymers, altered surface morphology with micronization and decreased crystallinity of drug particles.     

Gas-solid reactions I: A grain-cell model for complex reactions

A mathematical model has been developed to describe the progress of a consecutive reaction taking place in a porous spherical pellet composed of two solids. Two basic parameters are derived: a Thiele type modulus (H), and a kinetic-structural parameter (γ). The system of partial differential equations representing the model has been solved numerically, to obtain conversion-time relations as a function of the physical and kinetic parameters of the system. Highest conversions are obtained at low values of both γ and H.     

Regression‐based model for elastic constants of 2D braided/woven open mesh angle‐ply composites

The elastic constants of closed mesh braided/woven fabrics are generally obtained from finite element analysis, fabric geometry model, and modified classical laminate plate theory. These models are complex and often impractical for industrial design purposes and do not address the cases of open mesh braided/woven fabrics. This paper proposes an alternative to existing models and software packages. Simple regression‐based empirical equations were developed to obtain E_x, E_y, G_xy, and ν_xy of braided/woven fabrics at any angle‐ply angle using the braid/weave unit cell volume fraction (V_f0), the fiber volume fraction (V_f), and the elastic constants of an equivalent angle‐ply laminate (E, E, G, ν). Design equation predictions were verified by comparing them to a previously validated modified classical laminate plate theory (CLPT) model using various fiber/resin combinations. Excellent agreement was found for each set of results. POLYM. COMPOS., 26:152–164, 2005. © 2005 Society of Plastics Engineers     

Optimum concentration of reinforcement and solid lubricant in polyamide 12 composites for best tribo-performance in two wear modes

In general polymers are used in the form of composites (fiber reinforced, solid lubricated or both) in tribo-applications, where they may encounter more than one type of wear situations or mechanisms to different extents. The area of investigating the optimum concentration of fillers for best combination of tribo-performance in different wear modes and mechanical strength is sparingly researched. In this paper, research findings on the influence of the contents of short carbon fibers (CF) and PTFE (particulate form) in Polyamide (PA) 12 on friction and wear behavior in two wear modes (adhesive and fretting) have been reported. With increase in contents of CF up to 30% (vol) most of the mechanical properties and tribo-performance improved in adhesive and fretting wear modes. With a view to enhance it further, PTFE was added step by step in the best performing composite (PA+30% CF). This boosted the tribo-performance further, however, at the cost of strength properties. With increase in PTFE percentage (10, 15 and 20% by vol), specific wear rate (K _o) and friction coefficient (μ) both decreased appreciably in adhesive as well as fretting wear modes. The composite consisting of 30% CF and 20% PTFE showed lowest values for μ and K _o rendering it the best tribo-combination for all practical purposes. The abrasive wear behavior of composites was also investigated. However, wear performance in this mode showed exactly opposite trends. Inclusion of fibers or combination of fibers and PTFE proved detrimental.

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Prediction of surface tension of naphtha reformate using UNIFAC

The surface tension of naphtha reformate cuts (60?170°C) were predicted using a modified UNIFAC group contribution method. The naphtha was distilled into eleven cuts of 10°C intervals to obtain narrow boiling range cuts. The surface tensions were determined in the temperature range 10?50°C and were compared with predicted values. A standard deviation of 5.9% was found using this method, versus 3.7% when the corresponding states method was used over the temperature range of 60?170°C. However, for the higher temperature range of 140?170°C, this method gave a standard deviation of 2.9% versus 7.6% for the other method.     

Surfactant-Mediated Catalytic Determination of Fe(II) in Herbal and Pharmaceutical Products

In the present work, the catalyzed oxidation of neutral red (NR) by bromate was used to work out a kinetic-based analytical method as an alternative technique for the determination of Fe(II) in real and synthetic samples. A use of a surfactant, N-dodecylpyridinium chloride enhanced the sensitivity of the reaction by becoming involved in the reaction mechanism and providing a more suitable reaction environment. The iron-catalyzed oxidation of NR with potassium bromate was studied kinetically by using a fixed time method. The reaction was followed by measuring the decrease in absorbance at 535 nm. The use of a surfactant in the analytical run showed a five times increase in the sensitivity of the method. It served as a ready reservoir of NR by increasing its solubilization. The salt effect, pH, and reagent concentration were also investigated to achieve a more selective and sensitive analytical procedure. Under optimized conditions (4.2 × 10⁻⁵ mol L⁻¹ NR, 1.4 × 10⁻³ mol L⁻¹ KBrO₃, 1.5 × 10⁻² mol L⁻¹ cationic surfactant, 0.5 mol L⁻¹ LiCl and pH 2.60 at 30 °C), iron(II) was determined in the range 0.1–0.5 μg mL⁻¹ with a detection limit of 0.019 μg mL⁻¹ and a relative standard deviation (n = 6) 1.02% for 0.2 μg mL⁻¹ Fe(II). The influence of foreign ions on the accuracy of the results was investigated. The developed method is extremely sensitive, selective and simple. The method was applied successfully to the determination of iron in the herbal pharmaceutical and synthetic samples. The results showed good agreement with those obtained by atomic absorption spectrophotometry.