Comparative life cycle cost analysis of bio-valorized magnetite nanocatalyst for biodiesel production: Modeling, optimization, kinetics and thermodynamic study.

An active, high surface area, recyclable, magnetic, basic, iron oxide-based nanocatalyst was developed from banana leaves waste and used for microwave-assisted transesterification of soybean oil to biodiesel. According to the Hammett indicator, the catalyst has a high total basicity of 15 < H < 18.4. After optimization through the response surface methodology, the reaction allows 96.5 % biodiesel yield in the presence of 24:1 methanol to soybean oil molar ratio, 6 wt% BLW@Fe3O4, 0.5 h at 65 °C. The magnetic nature of the catalyst improves reusability for up to 6 cycles. Thermodynamic analyses showed that transesterification of soybean oil to biodiesel is an endothermic reaction. Moreover, the catalyst has the potential to reduce biodiesel production costs by utilizing abundant biomass waste materials. The calculated cost for 1 kg of catalyst is $1.14, while the biodiesel's cost per kg produced in this work is merely $1.05, showing high commercial viability.

Repetitive self-healing of Diels-Alder grafted graphene nanoplatelet reinforced carbon fiber reinforced polymer composites with outstanding mechanical properties.

The concept of using bio-inspired healing mechanisms in fiber-reinforced polymer (FRP)-based laminated composites is one of the trending areas of research for lightweight high-performance materials. To introduce self-healing in laminated composites, we developed Diels-Alder (DA) grafted graphene nanoplatelets (GNPs) and introduced them into carbon-fiber-reinforced polymer (CFRP) composites. The DA-grafted GNPs provided dual benefits, such as repetitive self-healing along with an increased mechanical performance of the modified CFRP. The GNPs were functionalized with DA adducts, i.e., bismaleimide and furfurylamine via a facile functionalization approach. The highest healing efficiency evaluated using double cantilever beam (DCB) tests was observed as ∼87% with more than 10 times repeated healing cycles. The innovative concept and strategy proposed in this work could be a gateway to a new area of research to upscale for industrialization of DA-based repetitive self-healable and durable CFRP-based composites.

Germline soma communication mediated by gap junction proteins regulates epithelial morphogenesis.

Gap junction (GJ) proteins, the primary constituents of GJ channels, are conserved determinants of patterning. Canonically, a GJ channel, made up of two hemi-channels contributed by the neighboring cells, facilitates transport of metabolites/ions. Here we demonstrate the involvement of GJ proteins during cuboidal to squamous epithelial transition displayed by the anterior follicle cells (AFCs) from Drosophila ovaries. Somatically derived AFCs stretch and flatten when the adjacent germline cells start increasing in size. GJ proteins, Innexin2 (Inx2) and Innexin4 (Inx4), functioning in the AFCs and germline respectively, promote the shape transformation by modulating calcium levels in the AFCs. Our observations suggest that alterations in calcium flux potentiate STAT activity to influence actomyosin-based cytoskeleton, possibly resulting in disassembly of adherens junctions. Our data have uncovered sequential molecular events underlying the cuboidal to squamous shape transition and offer unique insight into how GJ proteins expressed in the neighboring cells contribute to morphogenetic processes.

Insulin signaling modulates border cell movement in Drosophila oogenesis.

As collective cell migration is intimately involved in different aspects of metazoan development, molecular mechanisms underlying this process are being explored in a variety of developmental contexts. Border cell (BC) migration during Drosophila oogenesis has emerged as an excellent genetic model for studying collective cell migration. BCs are of epithelial origin but acquire partial mesenchymal characteristics before migrating as a group towards the oocyte. Here, we report that insulin signaling modulates collective BC movement during Drosophila oogenesis. Supporting the involvement of Insulin pathway, we demonstrate that compromising Insulin-like Receptor (InR) levels in BCs, inhibits their migration. Furthermore, we show that canonical Insulin signaling pathway components participate in this process. Interestingly, visualization of InR-depleted BC clusters, using time-lapse imaging, revealed a delay in detachment of BC clusters from the surrounding anterior follicle cells and altered protrusion dynamics. Lastly, based on genetic interactions between InR, the polarity determinant, par-1 and a regulatory subunit of Drosophila Myosin (spaghetti squash), we propose that Insulin signaling likely influences par-1 activity to engineer border cell detachment and subsequent movement via Drosophila Myosin.

Facile fabrication of epoxy-TiO2 nanocomposites: A critical analysis of TiO2 impact on mechanical properties and toughening mechanisms.

Optimized ultrasonic assisted dispersion of un-functionalized titanium dioxide (TiO2) nanoparticles (0.5-20wt%) into epoxy resin is reported. The investigation shows that there is a direct relation among nanoparticles content, inter-particle spacing and cluster size of the particles on the glass transition temperature (Tg) and tensile properties of the prepared nanocomposites. A significant improvement in tensile strength and modulus with minimal detrimental effect on the toughness was observed for the prepared composites, where compared to pristine epoxy resins, about 26% and 18% improvement in tensile strength and strain-to-break %, respectively, was observed for 10wt% particles loading, whereas a maximum improvement of about 54% for tensile toughness was observed for 5wt% particles loaded resins. The investigations found that a strong particle-matrix interface results in the enhancement of the mechanical properties due to leading toughening mechanisms such as crack deflection, particle pull out and plastic deformation.

Highly Selective Sub-ppm Naked-Eye Detection of Hydrazine with Conjugated-1,3-Diketo Probes: Imaging Hydrazine in Drosophila Larvae.

A pair of pyrene- and anthracene-based turn-on fluorescent probes (1 and 2, respectively) reported here can be easily synthesized in a single-step process and also exhibit outstanding sensing behavior toward hydrazine over various competing nucleophilic species and environmentally relevant ions. The probes display dramatic enhancements in the emission intensity with as high as 83- and 173-fold increases in the presence of hydrazine. Nitrogenous bases, thiols, and lanthanides do not interfere in the fluorometric detection. These probes enable the detection of hydrazine with the naked eye well below sub-ppm concentrations (ca. 30 ppb) with analytical detection limits of 5.4 ppb for 1 and 7.7 ppb for 2, which are far exceeded by the accepted lower limit for hydrazine (10 ppb) set by the US EPA. Simple paper strips based on these probes could be used for the detection of hydrazine even in the gas phase. Both of the probes could selectively detect hydrazine even in pond water samples efficiently. The probes were successfully applied to visualize, for the first time, accumulation of hydrazine in live fruit-fly larvae using epifluorescence microscopy. The novel and interesting detection mechanism, proposed on the basis of spectroscopic evidence and single crystal XRD results, indicates that the detection pathway proceeds via the initial step of a five-membered ring formation upon attack of the hydrazine, followed by a dehydration step for gaining aromaticity.

Enhanced crack suppression ability of hybrid glass fiber reinforced laminated composites fabricated using GNP/epoxy system by optimized UDM parameters.

In this work, GFRPs with layer-up [+22/-22/90n]s were prepared and hybridized with 0.5wt% of GNPs to introduce in-situ crack suppression ability. Optimization of the processing parameters of ultrasonic dual mode mixing (UDM) process was adopted to disperse GNPs uniformly in the epoxy system and place them evenly at the interfacial zones of GFRPs. Test results show that 102% and 153% enhancement in tensile strength and Young's modulus has been achieved by the proposed method. Low stirring speed and low pulse-off time show significant effect on properties of the GFRPs. The fragmentation behaviour was investigated under optical microscope for GNP infused hybrid GFRPs and compared to that of the control. Failure investigation examined under FESEM showed reduced delamination for hybrid GFRPs having randomly oriented GNPs in their interfacial zone. This work exposes the effective espousal of the process to prepare GNP infused hybrid GFRPs having crack suppression ability at the interfaces.

Epoxy/Glass Fiber Laminated Composites Integrated with Amino Functionalized ZrO2 for Advanced Structural Applications.

This work demonstrates the successful silanization of ZrO2 nanoparticles (ZN) and their incorporation in glass fiber/epoxy composites. Microscopic investigation under transmission electron microscope elucidates antiaggregation and size enhancement of silanized ZrO2 nanoparticles (SZNs). FTIR spectroscopy has been used to demonstrate the chemical nature of the SZNs prepared. EDX results reveal the presence of Si onto SZNs. Incorporation of SZNs shows a strong influence on tensile and flexural properties of hybrid multiscale glass fiber composite (SZGFRP) compared to that of the neat epoxy glass fiber composite (GFRP). A significant variation of tensile strength, stiffness, and toughness of ∼27%, 62%, and 110% is observed with respect to GFRP. Strength and modulus under bending are also enhanced to ∼22% and ∼38%, respectively. Failure mechanisms obtained from macroscopic and microscopic investigation demonstrate reduced interfacial delamination for SZGFRP. Additionally, increased roughness of the fiber surface in SZGFRP laminates produces better interfacial bonding arising from SZN incorporation in laminates. This symptomatic behavior exposes the espousal of organically modified ZrO2 to enhance the interfacial bonding for their use in next generation hybrid laminates.