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This study provides insights into the influence of sucrose (a water-soluble additive) on microstructure evolution in the transition region and steady-state region in ice-templated Li4Ti5O12 materials. A scanning electron microscope was employed for the two-dimensional characterization of microstructure in the transition region. Sucrose reduced the height of the transition region, caused an early alignment of ice lamellae toward temperature gradient direction, and resulted in a fine, dendritic microstructure. The overall microstructure development in the transition region was markedly different with and without sucrose. The differences were rationalized based on thermal conductivity, constitutional supercooling, and instability of the planar interface. Three-dimensional characterization of the steady-state region using X-ray computed tomography revealed that sucrose caused increased branching of the primary ice dendrites through tip splitting. A majority of the secondary dendrites turned into neighboring primary dendrites, enhancing pore path complexity. Diffusion simulations were performed to quantify pore tortuosity, which increased with sucrose content.

This paper describes novel soft dielectric elastomer composites that exhibits interesting features from the perspective of dielectric-elastomer transducer development, with enhanced actuation performance under an applied electric field that are potentially suitable for actuator applications. Materials solutions described are a combination of ceramic BN platelets, used at low loading levels, and a plasticizer (Naphthenic Oil) in a polymer matrix and synergistic effects between them that leads to enhancement in actuation strain by as high as 328% under applied electric field. Such functional dielectric composites would alleviate several issues such as size, functionality, and performance for many real-world actuator applications.

The geometry and spatial orientation of gelator molecules and the mode of various intermolecular non-covalent interactions are the key parameters that dictate the structure and properties of low molecular weight gelators (LMWGs). The effect of intermolecular non-covalent interactions in tuning the gelation properties was analysed for dipyridyl hydrazone (HL1) with an amide-like hydrogen bonding moiety and semicarbazone (HL2) with a urea-like motif. The gelation properties of the hydrazone and semicarbazone compounds were studied in a series of solvents and solvent mixtures and the SEM images of the xerogels revealed that the morphology of the HL2 gelator was more fibrous in nature compared to HL1. The mechanical and thermal stability of HL2 was higher than HL1, which was confirmed by rheology and gel–sol transition temperature experiments, respectively. The key non-covalent interactions responsible for gel formation were assigned using X-ray diffraction techniques and the results were corroborated with the gelation properties. The stimuli-responsive properties of the gelators were studied by analysing the effect of metal salts and anions on the gelation properties of HL1 and HL2 and the results indicated that metal complexation disrupted the gel network whereas the addition of anions did not alter the gelation ability of the gelators. The tuning of gelation properties by metal complexation and the comparison of intermolecular non-covalent interactions of the gelators enabled us to identify the key parameters responsible for gel-network formation in HL1 and HL2.

NiO-TiO2 (TN) nanocomposite is synthesized from an assembly of p-type nickel oxide (NiO) and n-type titanium oxide (TiO2) in an ultrasound assisted operation. Transmission electron microscopy (TEM) demonstrates the existence of hexagonal particles in the nanocomposite. Dynamic light scattering (DLS) measurements show stable TN nanoparticles (NPs) at a negative zeta potential (−18.5 ± 0.8 mV). The nanocomposite is tested for its catalytic activity towards degrading malachite green (MG), a known water toxicant and methylene blue (MB) under ultraviolet (UV) irradiation. Response surface methodology (RSM) is employed to optimise the influence of significant variables such as initial dye concentration, catalyst dose and time. Their mutual interactions are mapped by response surface and contour plots and correlated with degradation process by a designed model. The best photocatalytic efficiency (87%) is observed at an optimised concentration of 5 ppm dye with 10 ppm catalyst. The presence of inorganic ions and organic matter hardly affected the aggregate size of TN but caused a decline in photoactivity. The catalyst is found effective even in real water system (Hooghly River). A (Fluorine doped tin oxide) FTO/TN/Al heterojunction is fabricated. TN showed enhanced carrier mobility (1.03.10−4 m2V-1s-1) and low transit time (1.76.10-6 s) evaluated using space charge limited current (SCLC) theory. The nanocomposite appears suitable for energy preservation and environmental applications.

The role of metal salts in inducing supramolecular gel network formation was analysed by reacting two pyridyl-N-oxide amides with various diamagnetic zinc(II) and cadmium(II) salts. Metal induced s...

The structural modification of existing supramolecular architecture is an efficient strategy to design and synthesize supramolecular gels with tunable and predictable properties. In this work, we have modified bis(pyridyl urea) compounds with different linkers, namely hexylene and butylene, to their corresponding bis(pyridyl-N-oxide urea). The gelation properties of both the parent and the modified compounds were studied, and the results indicated that modification of the 3-pyridyl moieties to the corresponding 3-pyridyl-N-oxides induced hydrogelation. The stability of the parent and modified compounds were evaluated by sol-gel transition temperature (Tgel) and rheological measurements, and single-crystal X-ray diffraction was used to analyze the solid-state interactions of the gelators. The morphologies of the dried gels were analyzed by scanning electron microscopy (SEM), which revealed that the structural modification did not induce any prominent effect on the gel morphology. The stimuli-responsive behavior of these gels in the presence of salts in DMSO/water was evaluated by rheological experiments, which indicated that the modified compounds displayed enhanced gel strength in most cases. However, the gel network collapsed in the presence of the chloride salts of aluminum(III), zinc(II), copper(II), and cadmium(II). The mechanical strength of the parent gels decreased in the presence of salts, indicating that the structural modification resulted in robust gels in most cases. The modified compounds formed gels below minimum gel concentration in the presence of various salts, indicating salt-induced gelation. These results show the making and breaking ability of the gel network in the presence of external stimuli (salts), which explains the potential of using LMWGs based on N-oxide moieties as stimuli-responsive materials.

We report the asymmetric synthesis of homochiral metal-organic materials (MOMs) in chiral gels from achiral components. The enantioselectivity of MOMs depends on the chirality of the gel, whereas the synthesis performed in solution phase and achiral gels resulted in conglomerates.

Lignocellulosic biomass is extensively present as cheap-cost recyclable resource on the globe. Lignocellulosic biomass transformation toward value-added biomolecules is the most sustainable approach as it is not competing with food chain or feed cycle. Lignocellulosic biomass conversion to value-added products is being carried out following various existing routes such as thermochemical, chemical, and or biological avenues. However, biological route of lignocellulosic biomass conversation via enzymes is one the most feasible, rapid, and ecological benign approach. Diverse range of microbial communities have been involved to secret various extracellular cellulase enzymes that degrade stubborn lignocellulosic biomass into simple carbon sources, which can further be converted into value-added products starting from biofuel to bioplastics. However, catalytic activities of these cellulases are not up to the mark that can support industrial need at present due to lower substrate specificity, substrate conversion rate, and turnover number. To this end, many experimental analysis have already been carried out to improve the bioprocess development for enhancing lignocellulosic biomass degradation through engineering (mutations and genetic engineering) intervention on cellulase enzymes. Hence, this chapter will depict a critical overview on current research activities toward ameliorating cellulase enzyme catalytic efficacy through mutational, genetic, and protein engineering approaches for lignocellulosic biomass conversation to value-added products.

The combination of strong coordination bonds and hydrogen bonding interactions were used to generate a series of supramolecular coordination materials (SCMs), which was achieved by reacting a bis-pyridyl amide ligand, namely N-(4-pyridyl)nicotinamide (4PNA) with copper(II), zinc(II), and cadmium(II) benzoates. The SCMs were structurally characterized using X-ray diffraction and the key intermolecular interactions were identified via Hirshfeld surface analysis. The role of solvent molecules on the supramolecular architecture was analyzed by synthesizing the SCMs in different solvents/solvent mixtures. A solvent-mediated solid-state structural transformation was observed in copper(II) SCMs and we were able to isolate the intermediate form of the crystal-to-crystal transformation process. The luminescence experiments revealed that complexation enhanced the fluorescence properties of 4PNA in the zinc(II) and cadmium(II) SCMs, but a reverse phenomenon was observed in the copper(II) SCMs. This work demonstrated the tuning of supramolecular assembly in coordination compounds as a function of solvents for generating SCMs with diverse properties.

The parabolic pulse (PP) generation within an optical fiber occurs in the presence of gain. The required amount of gain can be supplied either physically or virtually by suitably tapering the core radius throughout the length of the fiber. Regarding PP generation, designing a dispersion increasing fiber (DIF) is undesirable as it introduces negative gain within the fiber. In this work, we have developed a special kind of a dispersion increasing chalcogenide fiber (DICF) where the nonlinearity-induced virtual gain plays the dominant function. In spite of the role of dispersion in reducing the effective gain, an efficient PP is generated in a sufficiently shorter fiber length without supplying any physical gain due to the much more substantial contribution from the nonlinearity of the fiber.

Generation of a self-similar parabolic pulse (PP) in presence of virtually gained normal dispersion tapered chalcogenide fibers is presented in this work. The variations of group velocity dispersion and mainly nonlinearity along the fiber length produce the proposed nonlinearity varying chalcogenide fibers (NVCFs) which can induce sufficient amount of virtual gain leading to obtain desired PPs at smaller optimum length. While studying the interaction among such pair of PPs, it is observed that an oscillating pulse train is created in the overlapping zone. The so generated beat frequency can be tuned in a range of 575– 832 GHz when a lengthwise variation of fiber is considered.

The present study demonstrates a synergistic effect with the addition of low loading levels of boron nitride filler in silicone rubber that resulted in significant improvement in both ac breakdown strength and thermal conductivity of silicone rubber composites. Our results show that addition of 2.5 vol% and 7 vol% of h-BN platelets improved thermal conductivity of silicone rubber composites by 25% and 65% respectively. The ac breakdown strength of silicone rubber composites was investigated by varying surface area and particle size of hexagonal boron nitride (h-BN) platelets. The breakdown strength of composites with only 2.5 vol% of low surface area boron nitride (0075) was enhanced by 20% and with high surface area boron nitride (7HS) was improved by 30%. The improvement in ac breakdown strength was primarily attributed to effective heat dissipation in the composite as well as low dielectric loss performance of the composite and was dependent upon the textural properties of boron nitride fillers.

Heavy metal has enormous toxicity on microbial metabolic pathways and its corresponding enzymes. Indiscriminate disposal of heavy metals in nature has a huge detrimental impact on the environment and ecosystem. Thus the minimal concentration of heavy metals should be maintained in environment with proper real-time monitoring. In general, ionic chromatography, mass spectrometry, inductively coupled plasma; polarography and usage of ion-sensitive electrodes are the most abundant approaches to detect the heavy metal contamination in nature. However, these current approaches suffer due to lower electrode selectivity, inaccurate response, and higher cost. Moreover, current avenues are not directly consociated with toxicity impact of these heavy metals. In general, algal alkaline phosphatases are a hydrolase (EC 3.1.3.1) class of enzymes, present in external membrane of microalgal regimes. Alkaline phosphatase enzyme transforms phosphoester molecules into soluble inorganic phosphate. However, its catalytic activity has strongly been inhibited in the presence of trace amount of heavy metals. This particular feature of algal phosphatase helps to detect these toxic heavy metals in nature even these are present in minute quantities. Based on this current global scenario, the current study is to focus on in silico screening and identification of algae-based alkaline phosphatases following systems biology approaches. The present study will help to (i) find out novel algae-based putative alkaline phosphatase protein sequences; (ii) bioinformatics and phylogenetic studies toward in silico characterizations, and (iii) algae-based alkaline phosphatase enzyme affinity toward diverse heavy metals especially cadmium and mercury. Therefore, this systems biology approach will accelerate the usage of algae-based alkaline phosphatase as a sustainable biosensor to detect the minute level of heavy metal toxicity in nature in the near future.

Lignocellulosic biomass utilization is a burning issue at present. Physicochemical composition of lignocellulosic biomass is highly complex. This phenomenon restricts its recycling toward biofuel generations. Diverse treatments have been applied to accelerate the lignocellulosic biomass breakdown. However, not any single approach is effective. Hence, the industry is looking forward to having sustainable microbial platforms that can ameliorate the lignocellulosic biomass accessibility. Therefore, a paradigm shift is expected to develop an efficient microbial cell factory generation that can degrade lignocellulosic biomass devoid of toxic intermediates. Genetic engineering, metabolic engineering, and biology approach could be able to fasten the process to achieve this goal by enhancing enzymatic activity, increasing substrate (cellulose, cellobiose, lignin, pectin, etc.) affinity, and finding novel enzymes; design novel metabolic pathways; and knock-out competing pathway to reduce toxic intermediate accumulations. Hence, the current book chapter summarizes promising genetic and metabolic engineering avenues to enhance lignocellulosic biomass degradation to improve its accessibility for biofuel generations.

Following the internationalisation of food production and manufacturing, a significant increase of food fraud was discovered, ranging from false label claims to the use of additives and fillers to increase profitability. The accidental or fraudulent mixing of animal products or by-products from different species is an important preoccupation for consumers with health or ethical concerns. Gelatin is widely used during food processing as well as in cosmetics, nutraceutics and medical formulations. It contains mainly type I, II and III collagen polypeptides. Gelatin speciation was performed using a well-defined proteogenomic annotation, carefully chosen surrogate tryptic peptides and analysis using a hybrid quadrupole-Orbitrap MS. Gelatin samples were dissolved in ammonium bicarbonate buffer and proteins were digested with trypsin. The samples were analysed using high-resolution MS. Chromatography was achieved using a 30-min linear gradient on a Thermo BioBasic C8 100 × 1 mm column at a flow rate of 75 μL min

This paper describes nonlinear dielectric composite passive components on flexible metallic substrates for transient protection of electronic devices, most notably against electrostatic discharge (ESD) and electrical overstress (EOS) conditions. In this case, the passive device comprises a polymer composite that contains nonlinear inorganic fillers, an electric field switchable dielectric ceramic Calcium Copper Titanate (CaCu3Ti4O12, CCT), in a metal insulator metal (MIM) configuration. Compatibility with PCB (printed circuit board) in line processing is demonstrated since the fabrication process described is a relatively low temperature process. Advantageously, the construction of such components are such that they can be embedded within a PCB (printed circuit board), thereby allowing miniaturization of the circuit design and can potentially be adopted in an industrial roll to roll manufacturing process. The dielectric characteristics of the CCT filler polymer composites are compared with well-known high dielectric constant Barium Titanate filler polymer composites for capacitor applications. Theoretical models based on effective medium theory are used to predict the dielectric properties of the CCT epoxy composites as a function of filler loading fractions. Maxwell Garnett model was found to provide the best fit to experimental data.

Publisher's version (útgefin grein), The factors affecting the self-assembly process in low molecular weight gelators (LMWGs) were investigated by tuning the gelation properties of a well-known gelator N-(4-pyridyl)isonicotinamide (4PINA). The N—H···N interactions responsible for gel formation in 4PINA were disrupted by altering the functional groups of 4PINA, which was achieved by modifying pyridyl moieties of the gelator to pyridyl N-oxides. We synthesized two mono-N-oxides (INO and PNO) and a di-N-oxide (diNO) and the gelation studies revealed selective gelation of diNO in water, but the two mono-N-oxides formed crystals. The mechanical strength and thermal stabilities of the gelators were evaluated by rheology and transition temperature (Tgel) experiments, respectively, and the analysis of the gel strength indicated that diNO formed weak gels compared to 4PINA. The SEM image of diNO xerogels showed fibrous microcrystalline networks compared to the efficient fibrous morphology in 4PINA. Single-crystal X-ray analysis of diNO gelator revealed that a hydrogen-bonded dimer interacts with adjacent dimers via C—H···O interactions. The non-gelator with similar dimers interacted via C—H···N interaction, which indicates the importance of specific non-bonding interactions in the formation of the gel network. The solvated forms of mono-N-oxides support the fact that these compounds prefer crystalline state rather than gelation due to the increased hydrophilic interactions. The reduced gelation ability (minimum gel concentration (MGC)) and thermal strength of diNO may be attributed to the weak intermolecular C—H···O interaction compared to the strong and unidirectional N—H···N interactions in 4PINA., We thank the University of Iceland Research Fund and the Science Institute for funding. D.G. thanks the University of Iceland for the Doctoral Research and Teaching Assistantship grant. We thankfully acknowledge Jonathan Steed, Durham University, Durham, UK for rheology experiments, Sigurjur Sveinn Jonsson, ISOR-Iceland for X-ray powder diffraction analysis, and Sigridur Jonsdottir, University of Iceland for NMR and mass spectroscopy. We thank Rannís Iceland for granting an infrastructure grant for a single-crystal X-ray diffractometer.

Cyclic adenosine monophosphate (3',5'-cAMP) is a multifunctional second messenger which controls extremely diverse and physiologically important biochemical pathways. Among its myriad roles, 3',5'-cAMP functions as an intracellular regulator of lysosomal pH, which is essential for the activity of acidic lysosomal enzymes. Defects in lysosomal acidification are attributed to many diseases like macular degeneration, Parkinson's, Alzheimer's, and cystic fibrosis. Strategic re-acidification of defective lysosomes by pharmacological increase of intracellular cAMP offers exciting therapeutic potential in these diseases. Modular assays for accurate assessment of intracellular cAMP and lysosomal pH are a critical component of this research. We describe label-free targeted metabolomics for quantitating intracellular cAMP and integrated assays for measuring lysosomal pH. These hybrid assays offer fast, unbiased information on intracellular cAMP concentrations and lysosomal pH that can be applied to many cell types and putative drug screening strategies.

We report the crystallisation of three forms of the copper(II) isonicotinate–N-oxide complex and their phase interconversion via solvent-mediated crystal-to-crystal transformation. The different forms of the copper complex have been isolated and characterised by single crystal X-ray diffraction. Gel phase crystallisation performed in hydrogels, low molecular weight gels and gels of a tailored gelator showed crystal habit modification. Crystallisation in aqueous ethanol resulted in the concomitant formation of blue (form-I) and green (form-II/IV) crystals while the use of a low molecular weight gel resulted in the selective crystallization of the blue form-I under identical conditions. Comparison of the gel phase and the solution state crystallisation in various solvent compositions reveals that the blue form-I is the thermodynamically stable form under ambient conditions.

This work is motivated by the structural gradient observed in natural materials to investigate the influence of the loading direction on the compressive response of ice-templated alumina-epoxy composites. Although this investigation is not on the development of multilayered composites with a structural gradient, the current results can help understand the mechanical behavior and design of such materials. Ice-templated alumina materials were developed from 20 vol% suspensions at high freezing-front velocity (FFV) and from 30 vol% suspensions at high and low FFVs. From porous ceramics, specimens were extracted at different orientations relative to the growth direction of ice crystals and infiltrated with epoxy. The resultant composites varied in ceramic fraction and morphology. For compression along the growth direction of ice crystals, specimens exhibited either high strength with brittle-like (catastrophic) failure or low strength with ductile-like (progressive) failure. Away from growth direction, strength decreased significantly, and failure was ductile-type. The strength exhibited a strong dependence on ceramic fraction and morphology. At each orientation, strength data of both porous ceramics and composites showed significant variability, and Weibull analysis suggested a connection between their strength. Direct visualization revealed the influence of loading orientation and morphology on deformation and failure in composites. Using the Tsai-Hill failure criterion, the role of competitive failure mechanisms on the compressive response of composites was evaluated. From the knowledge of composition, compressive and bend strength of ceramic phase, and yield strength of polymer phase, upper bound and lower bound of strength were predicted, which encompassed the strength of composites.

Ice-templating technique enables the synthesis of novel ceramic materials with directional, anisotropic pores, and the templated structure is highly tunable. Another factor that also drives interest in ice-templated ceramics is that for a comparable level of porosity, the uniaxial compressive strength of these materials can be significantly greater in comparison to that of the conventional open-cell foams. However, the strength advantage is significantly reduced in the materials templated from low solid loading suspensions. Toward this limitation, this study sheds insights into the influence of sucrose (a water-soluble additive) and freezing front velocity (FFV) on microstructure and the uniaxial compressive response of ice-templated sintered lithium titanate (LTO, composition Li4Ti5O12). This study used LTO as a model material. Materials were ice-templated from aqueous suspensions with 20 vol.% LTO powder and sucrose content was varied between 1–4 wt.%. The porosity of the sintered materials was in the range of 60–65 vol.%. Materials processed without sucrose exhibited lamellar morphology and low compressive strength. Sucrose had a marked influence on the connectivity between lamella walls, which significantly increased with sucrose content, and morphology became highly dendritic. The microstructural changes remarkably impacted compressive strength, which increased as high as eight-fold. Moreover, materials processed with sucrose exhibited a significant increase in strength in the continuous brittle crushing regime. By adjusting sucrose content in aqueous suspension and FFV, it is possible to synthesize ice-templated sintered LTO materials with tailored connectivity between lamella walls and harness compressive strength within a wide range of 4–80 MPa.

Short fiber reinforcement plays a definite role in governing the performance of a composite through the improvement of different material properties. The present investigation deals with the effect of aramid pulp and lapinas fiber on the friction and wear characteristics of a composite made from phenolic resin modified by powdered acrylonitrile butadiene rubber (NBR) on a pin-on-disc tribometer. Four composites, containing 10, 20, 30, and 40 wt% of aramid pulp with respect to phenolic resin content, were prepared. Another four composites, containing 50, 100, 200, and 300 wt% of lapinas fiber with respect to phenolic resin content, were also made. It was found that the two different fibers have distinctly different contributions to the friction and wear properties of the composites. It was also found that the incorporation of aramid pulp enhances friction stability of the composites much better than that of lapinas fiber. The change in surface morphology of these composites was studied by scanning ...

Polymeric outdoor insulators derived from polydimethyl siloxane (PDMS) are replacing conventional ceramic insulators in high voltage power transmission lines because of their improved electrical, mechanical and hydrophobic performance. Major impediments like failure of polymeric insulators due to natural aging by UV radiation from sunlight and electrical tracking have limited their usage. Herein, it is demonstrated about the usage of manganese dioxide based nanoparticles as an effective agent to prevent the UV accelerated aging of polymeric insulators. MnO2 nanoparticles of different shapes and dimension were synthesized using a single step wet chemical reaction between KMnO4 and methyl acetate. Namely, 2D δ-MnO2 nanosheets, 1D α-MnO2 nanowires and 3D α-MnO2 nanorods were formed. These nanoparticles were extensively characterized by various techniques. In the scope of the study, the δ-MnO2 (10−5 S cm−1; 1 MHz) nanosheet demonstrated the lowest electrical AC conductivity and a higher band gap compared to the 1D (10−4 S cm−1; 1 MHz) and 3D variety (10−4 S cm−1; 1 MHz). Owing to the lower electrical conductivity of the δ-MnO2 nanosheet, it was further incorporated at different filler volumes in the polymeric matrix (blend of polydimethyl siloxane/ethylene vinyl acetate) as a UV protector material for the polymer based high voltage composite polymeric insulator. The UV protection ability, induced by the δ-MnO2 nanosheet, was achieved without adversely affecting other properties of the formulated insulator compound material. The optimum properties of the composite were found to be obtained at 3 phr (three parts of δ-MnO2 nanosheet per hundred parts of polymer) loading of the nanosheet. The current work will promise to pave a new pathway for the generation of UV resistant high voltage power transmission line insulator materials. It would be interesting in the future to study the effect of incorporation of manganese dioxide based nanosheets on the UV resistant properties of different polymeric matrices.

The isolation of ten different cyanobacteria were carried out from northern parts of India and among them the cyanobacterium with maximum specific growth rate (0.246 day−1) was selected for the present study. The strain was further identified using morphometric and molecular analysis using 16S rDNA sequencing and was found to be related with Leptolyngbya sp. (GenBank accession no.: KF953500). The analysis of biomass composition showed ash content, amount of carbohydrate, lipid content, amount of protein, and moisture were found to be 6.8, 27.20, 18.30, 45.70, and 2% respectively. Over 26.6% increment in lipid content was evidenced when the strain was grown in BG11 medium augmented with salinity (25 mM sodium chloride) as compared to BG11 medium without sodium chloride. The unsaturated fatty acids was found 1.39 times higher than saturated fatty acids in KF953500. The lipid separated from cyanobacteria showed saponification value of 220.28, iodine value of 84.08, cetane number of 52.16, degree of unsaturation of 84.04 (%), long-chain saturation factor of 3.09 (%) and cold-filter plugging point of −6.76 °C which are generally in covenant with international standards of biodiesel. Other biodiesel properties such as pour point, flash point, acid number, viscosity, specific gravity, and density were found to be −18 °C, 126 °C, 0.34 mg KOH/g, 4.08 mm2 s−1, 0.812, and 854 kg m−3 respectively which falls within the acceptable ranges as per ASTM D6751 and EN 14214 standards, signifying the aptness of the microalga as promising sustainable feedstock for biodiesel.

The present research work was aimed at improving the high field dielectric properties of silicone rubber (SR) composites used for power cable insulation. Liquid silicone rubber composites were developed using two types of clays as filler materials; organically modified montmorillonite (ommt) and calcined, surface treated kaolin with the commercial name Translink 37 (T37). The results revealed that the surface chemistry of the clay had a distinct effect on both dispersion as well as electrical performance of silicone rubber-clay composites. We observed that surface treated kaolin (T37) were well dispersed in the SR matrix, but had adverse impact on the crosslinking kinetics of liquid silicone rubber resulting in higher dielectric loss at low frequencies. On the other hand, organically modified clay showed poor dispersion in the silicone rubber matrix while exhibiting much lower dc conductivity characteristics at high temperature. The agglomerated ommt macroparticles introduced the interfacial traps in SR matrix and charge carriers migration was limited within the matrix.

3D geocellular static models are the key input for fluid flow simulations with the main aim to predict the future reservoir performance for a particular recovery scheme. Since the predictability of the dynamic model depends on the quality of the geocellular model, it is imperative that the input data, the modelling workflow, methodologies and approaches are verified and validated prior to the sanction of the geocellular model. The objective of this paper is therefore to discuss the process of performing quality assurance and quality control (QA/QC) of 3D geocellular models exhibiting real field examples from the Middle East carbonate reservoirs. 3D static models are built using data from multiple sources, at different scales and with different degrees of uncertainty. The validation and reconciliation of all the data is of paramount importance. The procedure to build any geological model is very similar provided all the data is available. Some variations in the procedure are expected depending on the complexity of the phenomena to model, but must of the time workflows divert based on data quality and data availability. In this paper we discuss the use of key validation checks for each step of the modelling process taking into account the data quality and field maturity, namely for the 1)- structural framework modelling, 2)- facies modelling, 3)- porosity modelling, 4)- permeability modelling, 5)- rock type modelling, 6)- water saturation modelling, 7)- upscaling and 8)- uncertainty analysis. The use and validation of the applicability of secondary variables in the petrophysical modelling, such as acoustic impedance from seismic inversion, is also addressed. From the analysis of multiple geocellular models, inconsistencies were detected at different stages of the modelling process, starting from the well surveying with implications to horizontal well positioning within the framework, to the modelling of facies and petrophysical properties, with inconsistencies on variogram model parameters. Also, the validation of the velocity modelling and time-depth conversion used for the structural framework was validated by comparing FWLs depths against spill points. Furthermore, the quality of the facies model could be verified against regional facies belt maps (similar variogram azimuths are expected) while the validation of the permeability scale-up at well level could be achieved by reconciling with well test kh data. These are just a few examples of the material discussed in this paper. The novelty of the quality assurance process pertained to 3D geological models is the identification of appropriate metrics with key performance indicators for each step in the modelling workflow. At the end of the QA/QC process the models are ranked in quality and technical gaps identified for subsequent model improvement. Guidelines and best practices are also presented in this paper.

Mixing supramolecular gels based on enantiomers leads to re-arrangement of gel fibers at the molecular level, which results in more favorable packing and tuneable properties. Bis(urea) compounds tagged with a phenylalanine methyl ester in racemic and enantiopure forms were syn-thesized. Both enantiopure and racemate compounds formed gels in a wide range of solvents and the racemate (1-rac) formed a stronger gel network compared to the enantiomers. The gel (1R+1S) obtained by mixing equimolar amount of enantiomers (1R and 1S) showed enhanced mechanical and thermal stability compared to enantiomers and racemate gels. The preservation of chirality in these compounds was analyzed by circular dichroism and optical rotation measurements. Analysis of the SEM and AFM images revealed that the network in the mixed gel is a combination of enantiomers and racemate fibers, which was further supported by solid state NMR. The analysis of the packing in xerogels by solid state NMR spectra and the existence of twisted-tape morphology in SEM and AFM images confirmed the presence of both self-sorted and co-assembled fibers in mixed gel. The enhanced thermal and mechanical strength may be attributed to the enhanced intermolecular forces between the racemate and enantiomer and the combination of both self-sorted and co-assembled enantiomers in the mixed gel., We thank University of Iceland Research Fund for financial support. D.G. thanks University of Iceland for the Doctoral Research grant and Z.K. thanks University of Ljubljana for the Erasmus exchange program. We thankfully acknowledge Dr. A. Rawal, The Mark Wainwright Analytical Centre, UNSW for solid state NMR studies and Dr. Sigrídur Jónsdóttir, University of Iceland for solution NMR and Mass spectroscopy. P.T. thanks the Australian Research Council for an ARC Centre of Excellence grant (CE140100036) and A.D.M. thanks the National Health and Medical Research Council for a Dementia Development Research Fellowship (APP1106751). L.F. and A.V. thank the FCT (UID/BIO/04469/2013), COMPETE 2020 (POCI-01-0145-FEDER-006684), and Norte2020 Programa Operacional Regional do Norte (BioTecNorte operation, NORTE-01-0145-FEDER-000004) for rheological studies. The rheological study was supported by a STSM Grant from COST Action CM1402 Crystallize., info:eu-repo/semantics/publishedVersion

In this work, several normally dispersive highly nonlinear chalcogenide optical fibers (NDHNCFs) with a step-index profile have been designed and optimized in view of efficient parabolic pulse (PP) generation. A typical NDHNCF is selected such that the group velocity dispersion is highest among them and the corresponding nonlinearity is also very high. The input pulse parameters are optimized to find the lowest possible optimum length (Lopt) of the fiber where the linearly chirped PP is obtained. Further, it is found that for a shorter input pulse width, PP can be generated at a sufficiently smaller length of the NDHNCF with a slight compromise for its misfit parameter. A detailed analysis of the effect of pre-chirping helps to identify the suitable amount of initial chirp for different chalcogenide fibers with a choice of input pulse parameters. Although no improvement in PP generation is found for normal and initially chirped hyperbolic secant pulses, a highly efficient triangular pulse is achieved for a particular value of input pulse energy and the initial chirp parameter. Finally, the comparative study substantiates that our optimized NDHNCF is capable enough to generate quality PP at a length almost 70% shorter than a standard silica-based fiber.

In order to supplement the need for alternative energy resources within the near future, enhancing the production of biohydrogen with immobilized Clostridium beijerinckii NCIMB8052 was investigated. Magnetite nanoparticles were functionalized, with chitosan and alginic acid polyelectrolytes using a layer-by-layer method, to promote bacterial attachment. Cultivating C. beijerinckii with these nanoparticles resulted in a shorter lag growth phase and increased total biohydrogen production within 100-ml, 250-ml and 3.6-L reactors compared with freely suspended organisms. The greatest hydrogen yield was obtained in the 250-ml reactor with a value of 2.1 ± 0.7 mol H2/mol glucose, corresponding to substrate conversion and energy conversion efficiencies of 52 ± 18 and 10 ± 3 %, respectively. The hydrogen yields obtained using the immobilized bacteria are comparable to values found in literature. However, to make this process viable, further improvements are required to increase the substrate and energy conversion efficiencies.

Ceramic materials are commonly used as outdoor insulators for high voltage power transmission lines. Presently these ceramic insulators are replaced by composite polymeric insulators with silicone rubber (PDMS) housing, especially in industrial areas with pollution. Silicone rubber is chosen for housing material because of its excellent aging resistance, electrical properties, tracking resistance, and stable hydrophobicity which in turn control the tracking resistance. However, the material has deficiencies like poor mechanical strength and high cost. To improve the mechanical properties and reduce the cost, silicone rubber is blended with ethylene vinyl acetate copolymer (EVA). The optimum blend composition is found to be PDMS/EVA 60/40 w/w. But in doing so some reduction in hydrophobicity is observed, thus adversely affecting the tracking resistance. To improve hydrophobicity, the addition of nanosilica at the level of 6 phr is found to be the optimum. Thus high performance outdoor insulators can be produced from a PDMS–EVA blend containing 6 phr nanosilica. Different types of accelerated aging tests were performed on the insulator samples to simulate their aging behavior under different real life aging processes.

We report the selective gelation properties of the copper(II) complexes of N-(4-pyridyl)nicotinamide (4PNA). The morphology of the xerogels was examined by scanning electron microscopy (SEM). The correlation between the X-ray powder diffraction (XRPD) pattern of the xerogels and the single crystal structure of the copper(II) acetate complex suggests that the single crystal X-ray data represent a good structural model for the gel fibers, and that gelation arises from the presence of a 1D hydrogen-bonded chain between gelator amide groups and coordinated anions, while the presence of strongly bound water in non-gelator systems results in the formation of more extensively hydrogen-bonded crystalline networks. The selective gelation of all the copper(II) salts compared to the other metal salts may be attributed to the Jahn–Teller distorted nature of copper(II), which weakens water binding in all copper(II) salts.

Due to the internationalisation of food production and distribution, there has been a significant increase of food fraud in recent years. Food fraud can have serious health implications, and it occurs when food manufacturers implement unethical practices such as making false label claims as well as using additives and fillers within their products to increase profitability. This has been a serious concern. Meat adulteration was examined using a well-defined proteogenomic annotation, carefully selected surrogate tryptic peptides and high-resolution mass spectrometry. Selected mammalian meat samples were homogenised and the proteins extracted and digested with trypsin. Chromatography was achieved using a 30-min linear gradient along with a BioBasic C8 100 × 1 mm column at a flow rate of 75 µl min-1. The mass spectrometer was operated in full-scan high-resolution and accurate mass using resolving powers of 140,000 and 17,500 (FWHM) in full-scan MS and MS/MS respectively. Data independent acquisition (DIA) mode was used including 12 DIA MS/MS scans to cover the mass range 600-1200 m/z. Methodically in silico analyses of myoglobin, myosin-1, myosin-2 and β-haemoglobin sequences allow for the identification of a species-specific tryptic peptide mass lists and theoretical MS/MS spectra. Following comprehensive MS, MS/MS or DIA analyses, the method was capable of the detection and identification of very specific tryptic peptides for all four targeted proteins for each animal species tested with observed m/z below 3 ppm compared with the theoretical m/z. The analyses were successfully performed with raw and cooked meat. Specifically, the method was capable of detecting 1% (w/w) of pork or horse meat in a mixture before and after cooking (71°C internal temperature).

Outer membrane vesicles (OMVs) are secreted by all Gram-ve pathogens. These nano-scale delivery vehicles contain discrete arrays of prokaryotic pathogenic determinants, including a family of low molecular weight (MW) lipidic quorum signaling alkyl-quinolones (AQs). These are synthesized from β-keto-fatty acids and function like primordial lipidic hormones, which regulate numerous pathogenic factors both inter-species and intra-species. Significantly, AQs can also directly exacerbate pathogenesis by cross-kingdom signaling with the host immune, metabolic, and other systems. In Pseudomonas aeruginosa more than 50 AQs are reported; many with pathogenic mechanisms that are largely unknown. Some of these AQs are exclusively associated with OMVs. Accurate characterization of these OMV-AQs may reveal novel mechanism of diseases and Pseudomonas aeruginosa presents an ideal model. Matrix-free laser desorption/ionization mass spectrometry (LDI-MS) technologies enjoy unique advantages in mass spectrometry (MS)-based imaging and low MW analysis. We report single-step isolation of Pseudomonas aeruginosa OMV on inert ceramic filters and high-resolution mass spectrometry (HRMS) analysis of AQs vesicle in situ.

The depolarization behavior of lead zirconate titanate 95/5 and 52/48 has been well characterized under uniaxial strain with strain rates on the order of 106/s, and under quasi-static uniaxial stress loading with strain rates on the order of 0.1–100/s. This study examines the depolarization behavior under uniaxial stress at strain rates on the order of 10 to 103/s. Specimens were loaded using a split Hopkinson pressure bar. Loading rates from 7.2 to 92.5 MPa/µs were investigated, with a maximum stress of around 900 MPa. The results show significant depolarization rate sensitivity in lead zirconate titanate 52/48, while lead zirconate titanate 95/5 exhibits two responses above and below the stress rate of 50–60 MPa/µs, both with little rate sensitivity.

Microalgae are being investigated as potential candidates for biodiesel production since they can be grown without competition with food production, have an inherently fast growth rate, and can have a high lipid content under different nutrient limiting conditions. However, large scale production will best be carried out with indigenous strains, well adapted to local conditions. This study reports on the characterization of the novel microalga Chlorella sp. PCH90, isolated in Quebec. Its molecular phylogeny was established and lipid production studies as a function of the initial concentrations of nitrate, phosphate, and sodium chloride were carried out using response surface methodology. Under the appropriate conditions this microalga could produce up to 36% lipid and grew well in both synthetic medium and secondary effluent from a wastewater treatment plant at both 22 and 10 °C. Thus, this strain is promising for further development as a potential biofuels producer under local climatic conditions.

Mg–Al 2 O 3 nanocomposite powders, with Al 2 O 3 particles of 50 nm size, were synthesized by mechanical alloying starting from a mixture of 70 vol.% pure Mg and 30 vol.% Al 2 O 3 powders. A steady-state condition was obtained on milling the powder mix for about 20 h, when the crystallite size of the Mg powder was about 10 nm. The structural evolution during milling was monitored using scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction methods. The results showed that a mixture of Mg, Al 2 O 3 , and MgO phases were obtained on mechanical alloying. On annealing the milled powders at 600 °C for 30 min, a displacement reaction occurred between the Mg and Al 2 O 3 phases, when the formation of a mixture of pure Al and MgO phases was observed. Also, a reaction occurred between the initial Mg powder and Al formed as a result of the displacement reaction, leading to the formation of Mg 17 Al 12 , Al 0.58 Mg 0.42 , and Al 3 Mg 2 phases. Thus, the powder annealed after milling the Mg + Al 2 O 3 powder mix for 25 h consisted of Al, MgO and Al 3 Mg 2 phases.

Colossal permittivity (e′ = 301,484 at room temperature and 1 kHz) of barium titanate was induced in ceramics synthesized using the microwave sintering method. Three different sintering processes (conventional, spark plasma, and microwave) were performed to better understand colossal permittivity in sintered barium titanate. The dielectric permittivity measurements revealed that the appearance of colossal permittivity has strong dependence on the sintering temperature and atmosphere, and less on the grain size of the sintered ceramics. However, the as-sintered barium titanate samples produced by microwave sintering show high dielectric loss (tanδ > 1) consistent with oxygen reduction during the microwave sintering process and consequent accumulation of oxygen vacancies and associated charge carriers at the grain boundary. Since the highly conductive state of as-sintered ceramics precludes their use in dielectric applications, thermal annealing at different conditions was performed to recover insulating characteristics. Microwave-sintered barium titanate with post annealing process (950°C for 12 h in air) showed low dielectric loss (tanδ = 0.045) at room temperature and 1 kHz, while still showing a much higher permittivity (e′ = 36,055) than conventionally sintered barium titanate (e′ = 3500).

Hydrogen production from glucose via single-stage photofermentation was examined with the photosynthetic bacterium Rhodobacter capsulatus JP91 (hup-). Response surface methodology with Box–Behnken design was used to optimize the independent experimental variables of glucose concentration, glutamate concentration and light intensity, as well as examining their interactive effects for maximization of molar hydrogen yield. Under optimal condition with a light intensity of 175 W/m 2 , 35 mM glucose, and 4.5 mM glutamate, a maximum hydrogen yield of 5.5 (±0.15) mol H 2 /mol glucose, and a maximum nitrogenase activity of 246 (±3.5) nmol C 2 H 4 /ml/min were obtained. Densitometric analysis of nitrogenase Fe-protein expression under different conditions showed significant variation in Fe-protein expression with a maximum at the optimized central point. Even under optimum conditions for hydrogen production, a significant fraction of the Fe-protein was found in the ADP-ribosylated state, suggesting that further improvement in yields might be possible.

Replacement of fossil fuels with alternative energies is increasingly imperative in light of impending climate change and fossil fuel shortages. Biohydrogen has several potential advantages over other biofuels. Dark fermentation as a means of producing biohydrogen is attractive since a variety of readily available waste streams can be used. However, at present its practical application is prevented by the low yields obtained. Here the basic metabolisms leading to hydrogen production are outlined and current research to increase yields, either through modification of existing pathways, or by metabolic engineering to create new, higher yielding, pathways, is discussed. Inactivation of competing reactions and manipulation of culture conditions has lead to higher hydrogen yields, near those predicted by metabolic schemes. However, to be useful, hydrogen production must be increased beyond present limits. Several possibilities for surpassing those limits using metabolic engineering are presented.

Biodiesel manufacture produces crude glycerol as a major byproduct. At the scale estimated for future biodiesel production, extensive quantities of crude glycerol fraction will be generated, creating a large waste stream with potentially significant environmental impacts. The magnitude of projected future crude glycerol supplies suggests that its conversion to a biofuel is the only viable route to producing a product that does not cause market saturation. Previously it was shown that crude glycerol could be converted to hydrogen, a possible future clean energy carrier, by photofermentation using Rhodopseudomonas palustris through photofermentation. Here, the effects of nitrogen source and different concentrations of crude glycerol on this process were assessed. At 20 mM glycerol, 4 mM glutamate, 6.1 mol hydrogen/mole of crude glycerol were obtained under optimal conditions, a yield of 87% of the theoretical, and significantly higher than what was achieved previously.