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Polyhydroxybutyrate (PHB) is a natural polyester of microbial origin and is an excellent substitute for petroleum-based food packaging materials. However, moderate mechanical, thermal and barrier properties limit utilization of PHB for commercial food packaging applications. In order to overcome these drawbacks, the present study evaluated the solution casting method for the preparation of PHB nanocomposite by incorporating various concentration (0–1.3 wt%) of graphene nanoplatelets (Gr-NPs). The prepared nanocomposites were tested for their morphology, mechanical, thermal, barrier, cytotoxicity and biodegradable properties. A Gr-NPs concentration of 0.7 wt% was found to be optimum without any agglomeration. In comparison with pristine PHB, the PHB/Gr-NPs nanocomposite showed a higher melting point (by 10 °C), thermal stability (by 10 °C), tensile strength (by 2 times) along with 3 and 2 times reduction in oxygen and water vapour permeability, respectively. The penetration of UV and visible light was greatly reduced with the addition of Gr-NPs. Furthermore, cytotoxic effect of the prepared nanocomposite was found to be statistically insignificant in comparison with the pristine PHB. A four-fold increase in the shelf life was demonstrated by a simulation study conducted using moisture and oxygen-sensitive food items (potato chips and milk product). Unlabelled Image • Novel PHB/Gr-NPs nanocomposite was prepared by simple solution casting method. • PHB/Gr-NPs nanocomposite displayed superior barrier and mechanical properties. • PHB/Gr-NPs nanocomposite is less cytotoxic and highly biodegradable by soil biomes. • The PHB/Gr-NPs nanocomposite is highly suitable for food-packaging applications. [ABSTRACT FROM AUTHOR]

This work investigated the separation of polyhydroxybutyrate (PHB) containing Ralstonia eutropha cells from the culture broth using a novel ceramic based tubular membrane assembly. The culture broth was fed into outer surface of the membrane (shell side) and permeate was drawn from the tube side. Further, the number of ceramic membranes in the assembly was raised from 1 to 4 and its performance was assessed by measuring the broth flux, biomass and PHB recovery as a function of applied pressure (49 kPa -196 kPa). The present ceramic membrane is found to be highly efficient (99.9 ± 0.03%) in recovering the PHB from the culture broth. A maximum initial water flux of 444L m-2 h-1 and a permeate broth flux of 52 L m-2 h-1 was observed at the maximum applied pressure (196 kPa) and with four number of ceramic membranes added to the membrane assembly. Both biomass and PHB recovery were observed to decrease with an increase in the applied pressure; on the contrary, a reduction in the applied pressure enhanced the biomass and PHB recovery, but at the cost of low broth flux. However, this relationship is overcome by increasing the number of membranes in the membrane assembly. [ABSTRACT FROM AUTHOR]

Abstract Need for optical limiting devices that work on the basis of third order optical non-linearity has necessitated the search for different types of materials. Ferrites which show excellent magnetic properties are found to show optical non-linearity and have been exploited for this optical non-linearity in recent times. Current work explores the non-linear optical properties of nickel substituted manganese ferrites synthesized by wet chemical co-precipitation method. Structural studies on these samples indicated the formation of pure spinel ferrites with reduction in their crystallite sizes with increasing nickel concentration. The variation in particle size is similar to the measured optical band gap which is corroborated with the quantum size effect. Information on the presence and effects of defects in these samples are obtained from photoluminescence measurements. Z-scan measurements yielded non-linear optical parameters with their third order nonlinear susceptibility of the order of 10−6 esu. The observed self-defocusing effect was utilized to describe the optical limiting property with optical limiting threshold to be less than 2.5 mW for nickel substituted manganese ferrite nanoparticles under 532 nm CW laser. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs), including naphthalene, phenanthrene and fluoranthene are commonly found in wastewaters from refineries and biomass gasification industries. This study investigated the simultaneous biodegradation of these PAHs along with lipid accumulation by Rhodococcus opacus in a ternary substrate system. A 2 3 full factorial design of experiments was employed with the three PAHs at two different levels by varying their initial concentrations in the range 50–200 mg L −1 each. A maximum removal of 91.6%, 82.3% and 80.7% was achieved for naphthalene, phenanthrene and fluoranthene, respectively. The individual effect of PAH concentration was found to be more significant than 2-way and 3-way interaction effects on their degradation. PAH biodegradation efficiency in the mixture was mainly affected by initial concentration and aromatic complexity of the PAHs. Identification of the PAH degradation metabolites was carried out using LC-MS analysis, which clearly revealed that the PAHs were degraded primarily via the ortho/para pathway. This study demonstrates the potential utility of R. opacus for bioremediation and industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

This study investigated the performance of Tradescantia pallida in continuous removal of Cr(VI) from contaminated water using a laboratory scale vertical subsurface flow (VSSF) constructed wetland system. The effect of different hydraulic residence time (HRT), i.e. 1, 2 and 3 day HRT, was first studied at an influent Cr(VI) concentration of 20 mg/L. Later experiments were carried out at different influent pH (7 and 4) and at different influent Cr(VI) concentration (20 and 30 mg/L), but with the same HRT of two days. Best results were achieved for 2 d HRT and for an influent pH of 7 with a maximum Cr(VI) removal efficiency of 97.2–98.3% and a maximum total Cr removal efficiency of 86–88.2%. Cr(VI) was found to be uniformly distributed in different segments of the wetland units. Compared with the control unit in which no plants were grown, the units with the plant biomass showed substantially high amount of Cr(VI) in its soil (63–68%). Bioconcentration factor and translocation factor values ranged from 16.45 to 23.21 and 0.37 to 0.90 respectively, which revealed the excellent Cr uptake potential of T. pallida . The highest accumulated Cr concentration (464.33 mg/kg) was found in plants grown in the system at pH 7.0, whereas the minimum accumulated Cr concentration (249.21 mg Cr/kg) was in plants grown in the system at pH 4.0. Furthermore, 3–4% of the total Cr input into the system was accumulated in the plants at the end of the operation. All these results revealed an excellent performance of the T. pallida plant based constructed wetland system for continuous removal of Cr(VI) from contaminated water. [ABSTRACT FROM AUTHOR]

This study investigated the Cu(II) removal by Nostoc muscorum, a cyanobacterium isolated from a toxic metal polluted site in Meghalaya, using a batch photobioreactor with an aim to elucidate the removal mechanism and its effect on nitrate uptake by the cyanobacterium. Experiments were carried out using a batch photobioreactor by varying the initial Cu(II) concentration in the range of 5–30 mg L −1 . Results obtained in this study showed that a maximum of 5.628 ± 0.05 g L −1 of biomass concentration could be obtained in the absence of Cu(II), whereas this value of biomass reduces to 4.3 ± 0.0057 g L −1 in presence of 5 mg L −1 of initial Cu(II) concentration, which further reduces to 2.51 ± 0.01 g L −1 for an initial Cu(II) concentration of 30 mg L −1 . Besides, an increase in the initial Cu(II) concentration delayed the uptake of nitrate by the cyanobacterium. However, complete removal of Cu(II) was observed for all the four different initial Cu(II) concentration. The estimated value of nitrate uptake rate in the absence of Cu(II) was found to be 0.115 mg L −1 d −1 , which was reduced to 0.029 mg L −1 d −1 due to 30 mg L −1 initial Cu(II) concentration in the medium. The experimental nitrate uptake rate values were fitted to three unstructured kinetic models reported in the literature for estimating the biokinetic constants. Among the three models, Han-levenspiel and Andrew models fitted the experimental data closely with a determination coefficient (R 2 ) value of 0.942 and 0.921, respectively. The critical Cu(II) concentration obtained as per the Han-levenspiel model was found to be 0.0325 g L −1 . [ABSTRACT FROM AUTHOR]

Learning-based modelling methods are now being used to construct a precise prediction method for renewable energy sources. CI (Computational Intelligence) methods are proven to be effective in developing and optimising renewable instruments. Difficulty of this type of energy is determined by its coverage of enormous amounts of data as well as factors that must be properly analyzed. Soft computing approaches are widely recognized as critical instruments for improving performance of spinning electrical devices in both controls as well as design. The progress of gentle computing methods employed in rotating electrical machines is crucial for a wide range of energy conversion devices, including generators, high-performance electric engines and electric cars.This research proposes a novel technique for maintaining and controlling distributed energy systems. Here the maintenance and controlling data have been evaluated by differential evolution based local power distribution system (DE-LPDS) for control system as well as fuzzy radial basis function neural network (FRBFNN) is used in Micro-grid energy management system. The suggested energy management system is modelled to coordinate among many flexible sources by establishing priority resources, direct demand control signals, and power prices. Experimental results show various maintenance and controlling datasets in terms of QoS of 82%, energy efficiency of 95%, power consumption of 59 %, computational time of 34 ms and training accuracy of 95 % by proposed technique. • Learning-based modelling methods are now being used to construct a precise prediction method for renewable energy sources. • Difficulty of this type of energy is determined by its coverage of enormous amounts of data as well as factors, which must be properly analysed. • This research proposes a novel technique in maintenance and control of distributed energy systems. • The proposed energy management system is simulated to coordinate among multiple flexible sources by establishing priority resources, direct demand control signals, and power prices. [ABSTRACT FROM AUTHOR]

A green strategy of using citric acid as both an extractant and a cross-linking agent to expel and esterify ulvan – a marine polysaccharide from foliose Ulva sp. and filamentous Ulva sp. for hydrogel preparation was developed. Ulva sp. biomass of two different morphologies, foliose and filamentous Ulva sp., was collected from the Spiddal coast of Ireland to extract ulvan using a novel citric acid method which compared with conventional hydrochloric acid or water-based extraction methods. Extraction process parameters, viz. Ulva sp. load, extraction time, extraction temperature, and citric acid concentration, were optimised using the Taguchi experimental design. The optimised process parameters were 3 wt%, 4 h, 90 °C, and 1 wt%, respectively, for foliose and filamentous Ulva sp. At the optimised conditions, a maximum of 0.41 (±0.02) g/g and 0.39 (±0.04) g/g of ulvan yield with a protein content of 0.010 (±0.003) g/g and 0.007 (±0.002) g/g (dry weight basis) were obtained, respectively. This ulvan yield by citric acid-based extraction was superior in comparison with conventional hydrochloric acid (0.29 g/g) and water (<0.1 g/g) based extraction. Extracted ulvan was characterised and compared with commercial ulvan using proton - Nuclear Magnetic Resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, and differential scanning spectroscopy (DSC) analysis. Extracted ulvan was cross-linked with 2 wt% of citric acid to form hydrogel, and the cross-linking mechanism was found to be an esterification reaction using FTIR spectroscopy. Hybridization of ulvan with varying proportions of sodium carboxymethyl cellulose (Na-CMC) was carried out to uncover the broad applications of the hydrogel in health care, agriculture, and environmental fields. • Citric acid was used both as an extractant and cross-linker for hydrogel preparation. • Citric acid-based ulvan extraction outperformed conventional extraction techniques. • Characterization of ulvan revealed a close match with commercial ulvan. • A swelling degree of 387.5% was observed with hybrid Na-CMC and ulvan hydrogel. [ABSTRACT FROM AUTHOR]

Sulfate reduction by carbon monoxide (CO) utilizing anaerobic biomass from a large scale upflow anaerobic sludge blanket reactor was studied. Anaerobic mixed microbial consortia from five different sources were initially examined for their biological CO conversion potential. Among the different biomass, the biomass from an upflow anaerobic sludge blanket reactor treating domestic wastewater, located in Kavoor, Karnataka, India, showed a maximum CO conversion efficiency. The effect of three main culture parameters, i.e. inoculum volume, initial CO concentration and temperature on simultaneous CO conversion and sulfate reduction was assessed employing the Taguchi experimental design technique. A maximum CO conversion of 85.62% and a maximum sulfate reduction of 50.65% were achieved. Furthermore, the experimental data was fitted to substrate inhibition models reported in the literature. Among the different models, Monods and Haldane kinetic models were found most suitable to describe the kinetics of biomass growth and CO removal by the anaerobic biomass. [ABSTRACT FROM AUTHOR]

Abstract: We report the results of a systematic study of the thermal and optical properties of a new family of tellurite glasses, TeO2–ZnO–BaO (TZBa), as a function of the barium oxide mole fraction and compare them with those of TeO2–ZnO–Na2O (TZN). The characteristic temperatures of this new glass family (glass transition, T g, crystallization, T x, and melting, T m) increase significantly with BaO content and the glasses are more thermally stable (greater ΔT = T x − T g) than TZN glasses. Relative to these, Raman gain coefficient of the TZBa glasses also increases by approximately 40% as well as the Raman shift from ~680cm−1 to ~770cm−1. The latter shift is due to the modification of the glass with the creation of non-bridging oxygen ions in the glass network. Raman spectroscopy allows us to monitor the changes in the glass network resulting from the introduction of BaO. [Copyright &y& Elsevier]

The rapid depletion of crude-oil resource which sustains a conventional petroleum refinery together with its environmental impact has led to the search for more sustainable alternatives. In this context, biorefinery serves to fulfil the aim by utilizing waste resources. Hence, this study focused on techno-economic assessment of PHB production at large scale from waste carob pods in a closed-loop biorefinery setup. Firstly, the use of pure sugars in SC1 was shifted to use of carob pods as feedstock in SC2, upgradation of stirred tank bioreactor with novel annular gap bioreactor in SC3 and replacing the conventional centrifugation process with the upcoming ceramic membrane separation process in SC4. An Aspen plus™ flowsheet was developed by including the aforementioned novel strategies for PHB production. The effectiveness of PHB production under various scenarios was evaluated based on its pay-out period and turnover accumulated at the end of 7th year of a PHB plant operation. Instead of pure sugars as the feedstock (SC1), carob pod extract (SC2) reduced the pay-out period from 12.6 to 6.8 years. Likewise, switching onto ABR from the conventional STBR further decreased the pay-out period to 4.8 years. Finally, the use of ceramic membranes (SC4) instead of centrifugation resulted in a similar pay-out period of 4.8 years with increased turnover of about 1.4 billion USD. Thus, the use of carob pods along with an improved PHB titre in ABR and incorporation of affordable ceramic membrane technology for PHB rich biomass separation resulted in a highly cost-effective PHB production strategy. [Display omitted] • Aspen Plus flowsheet for PHB production with novel bioprocessing strategies is presented. • Utilization of carob pods as feedstock reduced pay-out period from 12.6 to 6.8 years. • Replacement of STBR with ABR reduced pay-out period from 6.8 to 4.8 years. • Use of membrane separation resulted in an annual turnover of 1.4 billion USD. [ABSTRACT FROM AUTHOR]

Abstract: Electrical switching and differential scanning calorimetric studies are undertaken on bulk As20Te80−x Ga x glasses, to elucidate the network topological thresholds. It is found that these glasses exhibit a single glass transition (T g) and two crystallization reactions (T c1 &T c2) upon heating. It is also found that there is only a marginal change in T g with the addition of up to about 10% of Ga; around this composition an increase is seen in T g which culminates in a local maximum around x =15. The decrease exhibited in T g beyond this composition, leads to a local minimum at x =17.5. Further, the As20Te80−x Ga x glasses are found to exhibit memory type electrical switching. The switching voltages (V T) increase with the increase in gallium content and a local maximum is seen in V T around x =15. V T is found to decrease with x thereafter, exhibiting a local minimum around x =17.5. The composition dependence of T c1 is found to be very similar to that of V T of As20Te80−x Ga x glasses. Based on the present results, it is proposed that the composition x =15 and x =17.5 correspond to the rigidity percolation and chemical thresholds, respectively, of As20Te80−x Ga x glasses. [Copyright &y& Elsevier]

Abstract: Time dependent photocurrent measurements have been undertaken on bulk Ge15Te85− x In x (1⩽ x ⩽11) series of glasses. It is found that samples with x <3 do not exhibit any photo-degradation whereas a decrease in photo-conductivity under illumination is observed in samples with x ⩾3. Further, the photosensitivity of Ge15Te85− x In x glasses is found to reveal specific signatures at compositions x =3 and 7. The observed composition dependent photo-degradation behavior and photo-response of these glasses have been understood on the basis of an extended rigidity percolation and its influence on network related properties. [Copyright &y& Elsevier]

• A novel closed-loop biorefinery approach was developed for PHB production. • R. eutropha outperformed the B. megaterium with maximum PHB concentration. • PHB yield and purity more than 90% was achieved for both the PHB producers. • Prepared PHB demonstrated its advantage in food packaging applications. A novel closed-loop biorefinery model using carob pods as the feed material was developed for PHB production. The carob pods were delignified, and as the second step, sugars present in the delignified carob pods were extracted using water. Ralstonia eutropha and Bacillus megaterium were cultivated on the carob pod extract and its performance was evaluated using Taguchi experimental design. R. eutropha outperformed the B. megaterium in terms of its capability to grow at a maximum initial sugar concentration of 40 g L−1 with a maximum PHB production of 12.2 g L−1. Finally, the concentrated lignin from the first step was diluted with different proportion of chloroform to extract PHB from the bacterial biomass. The PHB yield and purity obtained were more than 90% respectively using either R. eutropha or B. megaterium. Properties of the PHB produced in this study were examined to establish its application potential. [ABSTRACT FROM AUTHOR]

In this paper present, an electrostatic actuation mechanism based on the interdigitated electrode for the Biomedical Micro Electro Mechanical Systems (Bio-MEMS) sensors was mainly used for sensing or actuation in analytical and different detection applications. One of the main things interdigitated electrode (IDE) for capacitance derived from multiple electrode pairs has been connected in parallel with wide proof mass, folded spring beam attached as anchor in the sensor construction. The total capacitance was a sum of capacitance contributed by neighbouring electrodes. Hence the opposite walls of comb electrodes in the overlapping region form a parallel plate capacitor and contribute a capacitance C easily analyzed with fringe capacitance can be estimated to analytically difficult one. However, the nearly accurate way to estimate for the fringe capacitance is by using the finite element method (FEM). The major importance of the geometric dimensions on interdigitated electrode sensors are studied with an analytical model. The design of capacitive based IDE sensors are simulated and demonstrated on visualizing of the electrical properties by COMSOL Multiphysics software. [ABSTRACT FROM AUTHOR]

Abstract: Temporal variations of 210Pb, 21 2Pb and 7Be were measured at 1–2 h of intervals simultaneously at Tatsunokuchi, Shishiku Highland (640 m above sea level) and Hegura Island located 50 km from Noto Peninsula. It was recognized that variations of these nuclides occured in a short time depending on meteorological circumstances such as the passage of typhoon, snow fall and even in calm conditions. [Copyright &y& Elsevier]

Abstract Structural based molecular docking approach revealed the findings of 2-(phenoxymethyl) -5-phenyl-1,3,4-oxadiazole derivatives. The compounds (7a-o) were synthesized and characterized well by using conventional methods. The compounds, 7b and 7m were reconfirmed through single crystal XRD analysis. The synthesized compounds (7a-o) were evaluated their antiproliferative activities against MCF-7 and MDA-MB-453. Furthermore, Lipinski's rule of five and pharmacokinetic properties were predicted for the test compounds. These results demonstrate that the compounds 7b and 7d exhibit more potent cytotoxicity and 7d exhibits dose-dependent activity and reduced cell viability. Further, the mechanism of action for the induced apoptosis was observed through morphological changes and western blotting analysis. These findings may furnish the lead for further development. Graphical abstract Image 1 Highlights • 15 new compounds with 1,3,4-oxadiazole scaffolds were designed and synthesized. • The compounds, 7b and 7m were reconfirmed through single crystal XRD analysis. • The morphological changes and induced apoptosis in TNBC were observed after the treatment with the compound, 7d. [ABSTRACT FROM AUTHOR]