Power quality improvement with an extended custom power park

This paper describes the operation principles of an extended custom power park (CPP). The proposed park is more effective when it is compared to the conventional power parks regarding the yield of improving both current and voltage quality of linear and nonlinear loads using dynamic voltage restorer (DVR), active power filter (APF), static transfer switch (STS) and diesel generator (DG). Moreover, a supervisory power quality control centre is presented to coordinate these custom power (CP) devices by providing pre-specified quality of power. A fast sag/swell detection unit is also presented to improve the system response. The ability of the extended CPP for power quality improvements is further analyzed using PSCAD/EMTDC through a set of simulation tests.     

Amelioration of photofermentative hydrogen production from molasses dark fermenter effluent by zeolite-based removal of ammonium ion

One of the challenges in the development of integrated dark and photofermentative biological hydrogen production systems is the presence of ammonium ions in dark fermentation effluent (DFE). Ammonium strongly inhibits the sequential photofermentation process, and so its removal is required for successful process integration. In this study, the removal of ammonium ions from molasses DFE using a natural zeolite (clinoptilolite) was investigated. The samples were treated with batch suspensions of Na-form clinoptilolite. The ammonium ion concentration could be reduced from 7.60 mM to 1.60 mM and from 12.30 mM to 2.40 mM for two different samples. Photofermentative hydrogen production on treated and untreated molasses DFE samples were investigated in batch photobioreactors by an uptake hydrogenase deleted (hup⁻) mutant strain of Rhodobacter capsulatus. Maximum hydrogen productivities of 1.11 mmol H₂/L_c·h and 1.16 mmol H₂/L_c·h and molar yields of 79% and 90% were attained in the treated DFE samples, while the untreated samples resulted in no hydrogen production. The results showed that ammonium ions in molasses DFE could be effectively removed using clinoptilolite by applying a cost-effective, simple batch process.     

Scale-up studies for stable,long-term indoor and outdoor production of hydrogen by immobilized Rhodobacter capsulatus

Photofermentative hydrogen production by immobilized Rhodobacter capsulatus YO3 was carried out in a novel photobioreactor in sequential batch mode under indoor and outdoor conditions. Long-term H₂ production was realized in a 1.4 L photobioreactor for 64 days using Rhodobacter capsulatus YO3 immobilized with 4% (w/v) agar on 5 mM sucrose and 4 mM glutamate. The highest hydrogen yield (19 mol H₂/mol sucrose) and hydrogen productivity (0.73 mmol H₂ L^?1 h^?1) were achieved indoors on 5 mM sucrose. The effect of initial sucrose concentration (5 mM, 10 mM, and 20 mM) on hydrogen production was also investigated. Sustained hydrogen production was carried out under natural, outdoor conditions as well. For the outdoor experiments, the highest hydrogen productivity and yield were obtained as 0.87 ± 0.06 mmol H₂ L^?1 h^?1 and 6.1 ± 0.2 mol H₂/mol sucrose, respectively on 10 mM sucrose. Furthermore, this system prevented sudden pH drops and fluctuations caused by the utilization of sucrose throughout the process. These results demonstrate that a proper immobilization setup can lead to long-term efficient and robust hydrogen production even under naturally varying conditions.     

Evaluation of Mesua ferrea L. seed oil modified polyurethane paints

Two types of stoving paints have been prepared from Mesua ferrea L. seed oil (MFLSO) modified poly(urethane ester) (PUE) binder systems. One stoving paint system was prepared from partially butylated melamine formaldehyde (MF) resin modified MFLSO-based PUE (70:30 weight ratio) and other one comprised of bisphenol-A-based epoxy resin modified with MFLSO-based PUE (50:50 weight ratio). Paints made with these two resin systems as binders were evaluated against the standard paint system. The physical properties of the paint systems viz. non-volatile content, specific gravity, viscosity, drying time, flexibility, adhesion, scratch hardness, gloss, etc. and chemical properties such as corrosion resistance, salt spray resistance, UV resistance, etc. were measured as per the standard methods and were compared. Thermal stability and surface morphology of the paints were also studied by using thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), respectively. The performance characteristics of both the test paints were found to be comparable with the corresponding industrial standard paints. Out of the two test paints, the epoxy modified PUE-based stoving paint has been found to be preferred.     

Bio-based elastomeric hyperbranched polyurethanes for shape memory application

The bio-based shape memory hyperbranched polyurethanes (HBPUs) have attracted tremendous attention both from academic and industrial researchers due to their strong potential in biomedical and other advanced applications. In the present investigation HBPUs have been synthesized from poly(??-caprolactone)diol as a macroglycol, butanediol as a chain extender, triethanolamine as a branch generating moiety, monoglyceride of Mesua ferrea L. seed oil as a bio-based chain extender, at different percentages and toluene diisocyanate by a two step one pot A₂?+?B₃ approach. The structure of the synthesized hyperbranched polyurethane was characterized by FTIR, ^IH NMR, XRD and SEM studies. ¹H NMR study indicates the formation of highly branched structure with degree of branching 0.93 for polyurethane with 5?wt% monoglyceride. TGA results indicated the increment of thermal stability from 185 to 240?°C with the increase of monoglyceride content from (0?C15) wt% for the HBPUs. The shape memory effect of the hyperbranched polyurethane increased with the increase of monoglyceride in the polymer. However, mechanical properties like tensile strength and elongation at break decreased from 19.31 to 11.48?MPa and 835 to 497%, respectively, with the increase in amount of bio-based component. Excellent impact strength and very good chemical resistance were also observed for the hyperbranched polymers. The studied bio-based HBPUs exhibit excellent shape fixity (95?C99)% as well as shape recovery 100%. Thus, the studied HBPUs have the potential to be used as advanced shape memory materials.     

Effects of ammonium polyphosphate and triphenyl phosphate on the flame retardancy,thermal, and mechanical properties of glass fiber–reinforced PLA/PC composites

The purpose of this study is to increase of the flammability properties of the glass fiber (GF)–reinforced poly (lactic acid)/polycarbonate (PLA/PC) composites. Ammonium polyphosphate (APP) and triphenyl phosphate (TPP) were used as flame retardants that are including the organic phosphor to increase flame retardancy of GF‐reinforced composites. APP, TPP, and APP‐TPP mixture flame retardant including composites were prepared by using extrusion and injection molding methods. The properties of the composites were determined by the tensile test, limiting oxygen index (LOI), differential scanning calorimetry (DSC), and heat release rate (HRR) test. The minimum T_g value was observed for the TPP including PLA/PC composites in DSC analysis. The highest tensile strength was observed in GF‐reinforced PLA/PC composites. In the LOI test, GF including composite was burned with the lowest concentration of oxygen, and burning time was the longest of this composite. However, the shortest burning time was obtained by using the mixture flame retardant system. The flame retardancy properties of GF‐reinforced PLA/PC composite was improved by using mixture flame retardant. When analyzed the results of HRR, time to ignition (TTI), and mass loss rate together, the best value was obtained for the composite including APP.     

Mesua ferrea L. seed oil‐based epoxy resins

Exhaustion of fossil fuels, tremendous increase of materials demand, and unpredictable prices of petroleum based products urge upon the sustainable development. Three different epoxy resins have been synthesized from monoglyceride of Mesua ferrea L. seed oil and epichlorohydrin with and without other dihydroxy compound like tetrabromobisphenol‐A (TBPA) and bisphenol‐A (BPA). The synthesized epoxy resin were characterized by measurement of physical properties like epoxy equivalent, viscosity, hydroxyl value, saponification value, acid value, etc., and spectroscopic techniques like FTIR and ¹H NMR. High thermostability with initial decompositions temperature of 225–265°C was observed for the cured resins and 75 mol % BPA based resin exhibits the highest thermostability. Newtonian flow behavior was observed for all resins as indicated by the rheometric study (CVO 100). The flame retardency rating of TBPA based epoxy was found to be V1 as tested by UL 94. The performance characteristics as coating materials were studied by the measurement of gloss, impact resistance, scratch hardness, tensile strength, elongation at break, adhesive strength, and chemical resistance. The results indicate the suitability of the synthesized resins as coating materials. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Renewable resource modified polyol derived aliphatic hyperbranched polyurethane as a biodegradable and UV‐resistant smart material

Renewable resource tailored tough, elastomeric, biodegradable, smart aliphatic hyperbranched polyurethanes were synthesized using castor oil modified polyol containing fatty amide triol, glycerol, diethanolamine and monoglyceride of sunflower oil via an A_x + B_y (x , y ≥ 2) approach. To the best of our knowledge, this is the first report of the synthesis of solely aliphatic hyperbranched polyurethanes by employing renewable resources. The synthesized polyurethanes were characterized by Fourier transform infrared, NMR and XRD techniques. The hyperbranched polyurethanes exhibited good mechanical properties, especially elongation at break (668%), toughness (32.16 MJ m^?3) and impact resistance (19.02 kJ m^?1); also high thermal stability (above 300 °C) and good chemical resistance. Also, the hyperbranched polyurethanes were found to show adequate biodegradability and significant UV light resistance. Moreover, they demonstrated excellent multi‐stimuli‐driven shape recovery ability (up to 97%) under direct sunlight (10⁵ lux), thermal energy (50 °C) and microwave irradiation (450 W). The performance of the hyperbranched polyurethanes was compared with renewable resource based and synthetic linear polyurethane to judge the superiority of the hyperbranched architecture. Therefore, these new aliphatic macromolecules hold significant promise as smart materials for advanced applications. © 2017 Society of Chemical Industry     

Preparation and characterization of electrically semi-conductive polyfuran-coated poly(ethylene terephthalate) fibers

One of the most important textile materials, poly(ethylene terephthalate) (PET) fiber, was coated with a semi-conductive polyfuran (PFu) by in situ oxidative polymerization using FeCl₃ oxidant in solvent mixture of acetonitrile–chloroform. The effects of polymerization conditions such as volume ratios of acetonitrile/chloroform, monomer concentration, and oxidant/monomer mol ratio were investigated on PFu content (%) of the composites. It was observed that pretreatment of PET in dichloromethane increased PFu content and its coating continuity before polymerization. The highest PFu content (12.0%) was obtained using FeCl₃/furan mol ratios of 3.5 in acetonitrile/chloroform mixture (5/1). The density values of the composites with different PFu contents were measured. Composite fibers were also subjected to doping processes with HCl and I₂ vapors, separately, and it was observed that the surface resistivity of PFu/PET (10¹² Ω/cm²) reached to 53 Ω/cm² after doping with I₂. The structural, thermal, and morphological characterization was performed with FTIR, XRD, TGA, and SEM, respectively.