System innovations in open WDM DCI networks

Photonic Network Communications - We review the most important WDM system innovations motivated by the evolution of DCI transport. State-of-the-art coherent transmission has already exceeded 6...     

Identifying and Modeling the Strengths and Weaknesses of Major Economic Models in Grid Resource Management

Economic-based approaches have been found to be effective for distributed resource management in Grid computing. However, deciding which model to use is challenging, because (1) the performance stability of a particular model in a dynamic and distributed environment, is hard to establish (2) the performance objective of the Grid network may be complex, and it is difficult to know which model would best fit such an objective, (3) evidence indicates that no single model can cope with every scenario, and (4) no suitable tools exist to accurately predict and contrast the performances of one model with another model in a particular domain. Understanding the strengths and weaknesses of widely proposed economic models in terms of a range of scenarios is, therefore, crucial. To address this, the authors developed a general evaluation platform suitable for analyzing the performance of different economic models in the Grid. This work identifies domains of strength of individual models and highlights their use in various scenarios of Grid computing.     

A new addition to the family of polyesters—Synthesis and characterization of novel (alternating) poly(ether ester)s, poly(butylene 3-/4-hydoxy benzoate)s

Novel, predominantly alternating poly(ether ester)s, poly(butylene-3/4-hydroxy benzoate)s (PBHB)s were synthesized by the hydrogenation of the corresponding unsaturated polymers obtained by forming ether and ester linkages under one pot conditions. The ether substitution caused a reduction in glass transition temperature, T_g. The melting transition was also lowered by more than 100°C compared to poly(butylene terephthalate) as studied by the differential scanning calorimetry (DSC). Crystallization was observed during heating as well as cooling in the DSC studies. Wide angle X-ray diffraction (WAXRD) analysis also indicated that PB-4-HB was semi-crystalline in nature. The thermal stability of hydrogenated polymer was better than that of the unsaturated polymer.     

Characterization of Phosphate-Free Detergent Powders Incorporated with Palm C16 Methyl Ester Sulfonate (C16MES) and Linear Alkyl Benzene Sulfonic Acid (LABSA)

Laboratory and pilot scale investigations were carried out on phosphate-free detergent (PFD) formulations comprising binary anionic surfactants of C16 palm methyl ester sulfonates (C16MES) and linear alkyl benzene sulfonic acid (LABSA) with the aim of maximizing the incorporation of C16MES into low density detergent powders without compromising the detergency and other significant properties. Initial laboratory experiments revealed that the detergent powder resulting from C16MES/LABSA with a 50:50 ratio and pH 7–8 has acceptable detergency stability over 1 week of accelerated ageing test at 50 °C and 85 % relative humidity. Subsequent experiments were carried out in a 5-kg/h-capacity pilot spray dryer using PFD formulations of C16MES/LABSA over the whole range of weight ratios under the same pH of 7–8. The concentration of the detergent slurry and cleaning performance (detergency, foaming ability and wetting power) of the resulting spray dried detergent powder (SDDP) were evaluated. C16MES/LABSA in a 40:60 ratio was selected as the ideal formulation based on its optimum detergent slurry concentration and comparable cleaning performance against the control formulation. Further environmental tests have confirmed that SDDP obtained from the ideal formulation is readily biodegradable (60 % in 13 days) and exhibits low eco-toxicity properties (LC₅₀ of 11.3 mg/L).     

α-Sulfo Fatty Methyl Ester Sulfonate: A Review on Chemistry,Processing Technologies,Performance, and Applications in Laundry Detergents

α-Sulfo fatty methyl ester sulfonate (α-MES) is one of the anionic surfactants that is currently used commercially in the cleaning industry. Although the fundamental studies on α-MES were initiated as far back as the 1950s, it was only recognized as a class of surfactant in the 1980s. In the initial stage of development, α-MES has been associated with many technical impediments, which created a fear factor for the detergent industry to consider this oleo-based anionic surfactant for commercial production. However, all the technical adversities have been resolved after five decades of continuous active research and development activities. This paper will review the history, chemistry, process development, processing technologies, performance, commercial production, and applications of oleo-based based α-MES with special emphasis on palm oil-based α-MES. The paper also will highlight the challenges and adversities faced by the technology developers and product formulators toward the commercialization of α-MES as an active ingredient in the production of powder and liquid laundry detergents.     

Insights into evolutionary trends in molecular biology tools in microbial screening for biohydrogen production through dark fermentation

Access to clean energy is vital to combat global warming and climate change, and nothing but hydrogen could better deliver it with ease to secure future energy needs. Biohydrogen could be produced in different routes including photolysis, water-gas shift reaction, dark, photo-fermentation and combination of both. Dark fermentative hydrogen production (DFHP) is efficient in comparison with photo-fermentation and utilizing organic waste ensures land usage and water for agriculture. Several microbes are involved in the process of biohydrogen production via dark fermentation and characterizing them at molecular level unveils holistic approach and understanding. Limited resources were available in terms of molecular tools for microbial characterization and this paper attempts to review the evolution of advanced molecular techniques including their merits and demerits. Understanding the composition of micro-flora is important in DFHP and could be classified as pure, co-cultures, enriched mixed cultures and mixed microbiota. These cultures act as seed sources for batch and continuous fermentations that help in understanding the efficiency of these methods. The schematics and systematic assessment of the various molecular tools (cloning, PCR-DGGE, FISH, NGS, CE-SSCP) for quantification, identification, detection and characterization of the microbial cell activity have been elaborated. Lastly, a comparative tabulation recapitulates the merits and drawbacks of each technique discussed. This provides valued information for choosing the right kind of microbial and molecular assessment tool for future characterization. Such analysis aids in suitable identification and characterization of microflora as potential biocatalysts for biohydrogen production through dark fermentation.     

Oxidative stress and the development of diabetic complications--antioxidants and lipid peroxidation in erythrocytes and cell membrane

Erythrocytes isolated from 131 cases of Non-Insulin Dependent Diabetes Mellitus (NIDDM) were studied for lipid peroxidation, antioxidant defences, and the maximum peroxidisable substrate in the cell membrane. Antioxidant defences are lowered in NIDDM, followed by significant rise in lipid peroxidation products. However, in the erythrocyte membrane, the total polyunsaturated peroxidisable lipids are lower than in normal erythrocytes which may be a causative factor affecting the survival of the cells.     

Carbon-Incorporated Amorphous Indium Zinc Oxide Thin-Film Transistors

We propose the use of amorphous-carbon indium zinc oxide (a-CIZO) as a channel material for thin-film transistor (TFT) fabrication. This study chose a carbon dopant as a carrier suppressor and strong oxygen binder in amorphous-indium zinc oxide (a-IZO) channel material. a-CIZO thin films were deposited using radiofrequency (RF) sputtering and postannealed at 150°C. X-ray diffraction and transmission electron microscopy analysis revealed that the film remained amorphous even after postannealing. The a-CIZO TFT postannealed at 150°C exhibited saturation field-effect mobility of 16.5 cm² V^?1 s^?1 and on–off current ratio of ～4.3 × 10⁷.     

Supercapacitive properties of activated carbon electrode using ammonium based proton conducting electrolytes

In this study, we demonstrated the usefulness of proton conducting electrolytes (such as ammonium thiocyanate (NH₄SCN) and ammonium nitrate (NH₄NO₃)) for electrochemical energy storage devices using activated carbon (AC) as the electrode material. The cyclic voltammetry analysis revealed the presence of rectangular shaped cyclic voltammograms indicating the presence of electrical double layer capacitance in AC electrode using NH₄SCN and NH₄NO₃ electrolytes. The mechanism of charge-storage in AC electrode using the proton conducting electrolytes has been studied in detail using electrochemical impedance spectroscopy (Nyquist and Bode plots). The galvanostatic charge-discharge analysis revealed that a maximum specific capacitance of AC electrode using NH₄SCN and NH₄NO₃ electrolytes was found to be 136.75 mF cm^?2 and 113.38 mF cm^?2 at a current density of 0.5 mA cm^?2. This study would open a new avenue for the use of ammonium based proton conducting electrolytes for supercapacitor applications.     

Water-based UV curable hybrid urethane-acrylates formed by acid–base interaction between tertiary amine containing polyurethane and acrylic acid for photocoating and ink applications

Urethane acrylate hybrids are commonly used in polyurethane dispersions (PUD). PUDs are key ingredients in UV curing applications and UV curing is widely used in coatings and inks. The preparation of PUDs involves many volatiles in the form of solvents and reagents that are also carried over in the UV curing step. This article reports a process, which totally eliminates these volatile components and additionally introduces many flexibilities. The process involves acid–base interaction between tertiary amine containing polyurethane and acidic vinyl monomer like acrylic acid forming polyurethane-acrylate (PU-AA) hybrids in water. The developed process also overcomes the prepolymer and “endcapping” approaches used in the preparation of PUDs that restrict the molecular weight of polyurethanes. Simultaneously, because of the prevalence of large number of vinyl components in the polymer backbone through the acid–base interaction, it functions as a multifunctional acrylate similar to the reactive diluents used in UV curing applications. Thus, it helps to increase the cross-linking density of the UV cured substrates. In general, high crosslinking density helps to improve characteristics like hardness, scratch, solvent and stain resistance of coated substrates. The process has been demonstrated to form transparent and opaque coated substrates and cured inks. This development potentially helps to shift the process from an industrial activity to do-it-yourself domain and has implications for the development of components for 3D printing sustainably.