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PurposeThe changes in tensile behavior of polycrystalline nanocopper lattice with changes in temperature, average grain size (AGS) and strain rate, have been explored. The existence of a critical AGS has also been observed which shows that the Hall–Petch relationship behaves inversely.Design/methodology/approachNanoscale deformation of polycrystalline nanocopper has been done in this study with the help of an embedded atom method (EAM) potential. Voronoi construction method has been employed for creating four polycrystals of nanocopper with different sizes. Statistical analysis has been used to examine the observations with emphasis on the polycrystal size effect on melting point temperature.FindingsThe study has found that the key stress values (i.e. elastic modulus, yield stress and ultimate tensile stress) are significantly influenced by the considered parameters. The increase in strain rate is observed to have an increasing impact on mechanical properties, whereas the increase in temperature degrades the mechanical properties. In-depth analysis of the deformation mechanism has been studied to deliver real-time visualization of grain boundary motion.Originality/valueThis study provides the relationship between required grain size variations for consecutive possible variations in mechanical properties and may help to reduce the trial processes in the synthesis of polycrystalline copper based on different temperatures and strain rates.

The present paper studies the thermal-hydraulic behaviour of the rectangular supercritical natural circulation loop (SCNCL) using numerical model of one dimensional. Then the results of this model is confirmed with experimental and benchmark results. Variations with several geometric parameters like loop diameter, riser length, and heater length and operating conditions like heater inlet enthalpy, pressure, friction factor, and inlet and exit loss coefficient on steady-state performance are investigated for various orientations like HHHC , HHVC, VHVC and VHHC of the heater and cooler. The chances of existing static instability (Ledinegg excursion) has been investigated, which reveals that it can arise only in a low inlet enthalpy condition, far from the suggested various orientations of heater and cooler.

Temperature, strain rate, and defects are important considerations in determining the mechanical properties of materials. The mechanical properties of nanocrystalline copper-tantalum (Cu-Ta) alloy are investigated using classical molecular dynamics simulation approach in which embedded atom method of potential with periodic boundary conditions in all directions has been adopted. Numerical simulation has been performed to predict the mechanical properties of nanocrystalline copper-tantalum alloy. The virtual tensile test has been conducted at a fixed strain rate and increasing temperature where the discreet change in temperature from 50 to 1600 K has been used as a controlling parameter. The strain rate is fixed in the direction of the principal crystallographic planes and has not been affected by the change in temperature. The mechanical properties of the Cu-Ta nanocrystalline alloy such as yield strength, ultimate strength, and Young's modulus are observed. Further, simulations are carried out to analyze the vacancy formation energy with vacancy concentration and potential energy response at discrete temperatures. Nanocrystalline Cu-Ta alloy is observed to be more susceptible to failure at high temperatures. Particularly at 300 K, the strength of nanocrystalline Cu-Ta is 6 GPa which decreases to 4 GPa at 1200 K.

The development of a new crop variety is a time-consuming and costly process due to the reliance of plant breeding on gene shuffling to introduce desired genes into elite germplasm, followed by backcrossing. Here, we propose alternative technology that transiently targets various regulatory circuits within a plant, leading to operator-specified alterations of agronomic traits, such as time of flowering, vernalization requirement, plant height or drought tolerance. We redesigned techniques of gene delivery, amplification and expression around RNA viral transfection methods that can be implemented on an industrial scale and with many crop plants. The process does not involve genetic modification of the plant genome and is thus limited to a single plant generation, is broadly applicable, fast, tunable and versatile, and can be used throughout much of the crop cultivation cycle. The RNA-based reprogramming may be especially useful in plant pathogen pandemics but also for commercial seed production and for rapid adaptation of orphan crops. The implementation of RNA viral transfection technology in multiple plant species allows transient expression or silencing of specific regulatory genes in various regulatory circuits to rapidly fine-tune multiple traits without modifying the genome.

In this work we have focussed to examine the effect of carbon black (CB) (3 wt%) and reactive organo-modified montmorillonite R-OMMT (1–3 wt%) on rheological, tensile, thermal, and fracture propert...

This paper reports on molecular dynamic simulation approach for the modeling and simulation of nanocrystalline Nitinol (NiTi). The relation between stress–strain behaviour of NiTi at the multiple steps of temperature ranging from 300 K to 1300 K at a particular strain rate 1 × 10-1 sec-1 and observed at a fixed temperature of 300 K with the variation in strain rate in the order of tens. It has been noticed that the value of stress-bearing capacity of NiTi is decreasing slowly with the increasing temperature in the multiple steps from 300 K to 1300 K and the value of strength in the stress-strain curve of NiTi increases with increase in strain rate at that particular temperature. Elastic constant and ultimate strength at different temperatures and strain rates were also recorded to examine their individual dependence on the stress–strain behaviour of NiTi alloy.

In this paper, the impact of thickness of a bio-phase change material (b-PCM) and its effectiveness towards thermal execution and comfort of a building wall is studied using ANSYS. Two models have been simulated among which the primary model is a reference room which do not contains b-PCM and the secondary model is one including b-PCM with varying thickness. A b-PCM can more constructively decrease the heat transfer to the inner side room due to lower thermal conductivity and higher latent heat of phase change. In addition, the thermal conductivity has need over other PCM thermo physical properties. The lower thermal conductivity of PCM allows lower amount of heat to the inside room space. The observations of present work reveal the information that the expansion of PCM layer thickness has significant impact for delivering a higher temperature contrast, past specific timings of the peak surrounding temperature. Likewise, the utilization of PCM empowers better ability to hold starting temperature for longer timeframe.

Advances made in genome sequencing projects and structural genomics are generating large repertoire of candidate genes in plants associated with specific agronomic traits. Rapid and high-throughput functional genomics approaches are therefore needed to validate the biological function of these genes especially for agronomically important crops beyond the few model plant species. This can be achieved by utilizing available gene knockout or transgenic methodologies, but these can take considerable time and effort particularly in crops with large and complex genomes such as wheat. Therefore, any tool that expedites the validation of gene function is of particular benefit especially in cereal crop plants that are genetically difficult to transform. One such reverse genetics tool is virus-induced gene silencing (VIGS) which relies on the plants' natural antiviral RNA silencing defence mechanism. VIGS is used to downregulate target gene expression in a transient manner which persists long enough to determine its effect on a specific trait. VIGS based on Barley stripe mosaic virus (BSMV) is rapid, powerful, efficient, and relatively inexpensive tool for the analysis of gene function in cereal species. Here we present detailed protocols for BSMV-mediated VIGS for robust gene silencing in bread wheat and related species.

This work entails the effectiveness of hydroxyapatite (HAp) as secondary filler in polypropylene (PP) matrix composites reinforced with HAp-decorated multiwalled carbon nanotubes (MWCNTs). Different composites were prepared through the melt mixing approach. The consequent effect of typical biocompatible ceramic coating on the dispersion of CNTs in a PP matrix and thereby effect on its thermal and mechanical properties have been discussed in this research work. Isothermal hydroxylation technique has been used for the coating of HAp on MWCNTs. It has been observed from the collective information obtained from X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy and field-emission scanning electron microscopy images that HAp constitutes a new phase in the HAp-CNT nanocomposite in the form of a coating of HAp over nanotubes. As a result of which, the use of HAp-coated MWCNTs in PP improved its tensile strength by 38%, modulus of elasticity by 72%, storage modulus by 43% and ductility by around 7.4% in comparison to uncoated MWCNT-reinforced PP composite. However, the coating of HAp shows an insignificant effect for change in temperature-dependent properties of the CNT/PP composites. The improvement in mechanical properties is attributed to the interfacial compatibility between HAp and PP.

This work presents a unique type of hybrid composite which shows a significant improvement in mechanical and thermal properties than that of its pristine form of filler. The acid functionalization of carbon black and its use as filler in acrylonitrile butadiene styrene (ABS)/polyaniline (PANI) blend have resulted in promising improvement in mechanical and thermal properties. With the acid-functionalized carbon black when used as filler in the same blend with a compatibilizer (nanoclay), the blend exhibits further enhancement in tensile strength, modulus and thermal stability of the composite. Finally, with a good compatibilization using nanoclay (NC), the hybrid composite have shown 58% improvement in tensile strength and improvement in thermal decomposition temperature by around 70 °C. In addition, NC assisted for the transformation of unstable interaction between ABS and PANI to more stable configuration by assisting PANI to homogeneously incorporate to the polymer matrix, thereby increases the degradation onset temperature in TGA, up to 460 °C.

Nano-structured materials have become prominent in diversified fields of engineering and materials science. However, high cost and complicated techniques for synthesis of nanomaterials restrict their development. The use of different molecular dynamic simulation techniques simplified the validation of possible nanostructures and evaluation of their mechanical, physical, and chemical properties. In addition, the surface modification of nanomaterials to overcome the drawback of existing defects or improvement in interfacial properties has been a key issue for using such nanostructures in structural composites or thin films. Simulation techniques have also been found very useful to conduct random surface modification possibilities of nano-structured 2D materials without the need of time-consuming and sophisticated experiment setups which restrict the researchers for repetitive experimentations. This chapter entails typical simulation techniques which can be used for assessing different carbonous and non-carbonous nanomaterials. It will also enable to understand the various possibilities for surface modification and evaluation of properties of the characteristic nanomaterials.

In present paper, a mathematical model based on the one dimensional nonlinear mass, momentum and energy conservation equations has been developed to study the density wave instability (DWI) in horizontal heater and horizontal cooler supercritical water natural circulation loop (HHHC-SCWNCL). The one dimensional nonlinear mass, momentum and energy conservation equations are discretized by using finite difference method (FDM). The numerical model is validated with the benchmark results (NOLSTA model). Numerical simulations are performed to find the threshold stability zone (TSZ) and draw the stability map for natural circulation loop. Further, effect of change in diameter and riser height on the density wave instability of SCWNCL has been investigated.

The present paper is to study and explore the possibility of static instability, Ledinegg flow excursion, in a rectangular supercritical natural circulation loop (RSCNCL). Due to drastic change of thermo-physical properties of fluid near the pseudo-critical point, various static and dynamic instabilities might occur in the loop. The instability may be either Ledinegg excursion or density wave oscillations (DWOs). Many previous researchers have analyzed dynamic instability, DWO, in SCNCL, whereas the Ledinegg excursive instability is not studied in depth. In the present research work, a mathematical model will be implemented to predict the Ledinegg instability in SCNCL. The numerical investigation is successful to find whether there would be any Ledinegg instability in the case of SCNCL or not.

Stem rust caused by the fungus Puccinia graminis f. sp. tritici (Pgt) is a devastating disease of the global staple crop wheat. Although this disease was largely controlled in the latter half of the twentieth century, new virulent strains of Pgt, such as Ug99, have recently evolved

Disruption of the ARF-GEF protein encoding gene AtMin7 in Arabidopsis and silencing of the orthologous gene in wheat result in hypersusceptibility to the fungal pathogen Fusarium graminearum., Plants have developed intricate defense mechanisms, referred to as innate immunity, to defend themselves against a wide range of pathogens. Plants often respond rapidly to pathogen attack by the synthesis and delivery to the primary infection sites of various antimicrobial compounds, proteins, and small RNA in membrane vesicles. Much of the evidence regarding the importance of vesicular trafficking in plant–pathogen interactions comes from studies involving model plants whereas this process is relatively understudied in crop plants. Here we assessed whether the vesicular trafficking system components previously implicated in immunity in Arabidopsis play a role in the interaction with Fusarium graminearum, a fungal pathogen well-known for its ability to cause Fusarium head blight disease in wheat. Among the analysed vesicular trafficking mutants, two independent T-DNA insertion mutants in the AtMin7 gene displayed a markedly enhanced susceptibility to F. graminearum. Earlier studies identified this gene, encoding an ARF-GEF protein, as a target for the HopM1 effector of the bacterial pathogen Pseudomonas syringae pv. tomato, which destabilizes MIN7 leading to its degradation and weakening host defenses. To test whether this key vesicular trafficking component may also contribute to defense in crop plants, we identified the candidate TaMin7 genes in wheat and knocked-down their expression through virus-induced gene silencing. Wheat plants in which TaMin7 genes were silenced displayed significantly more Fusarium head blight disease. This suggests that disruption of MIN7 function in both model and crop plants compromises the trafficking of innate immunity signals or products resulting in hypersusceptibility to various pathogens.

The present investigation reveals the effect of addition of zirconia-coated multiwalled carbon nanotubes (MWCNTs) on mechanical and thermal properties of polypropylene (PP) matrix composites. Initially, zirconia coating on MWCNTs (ZrO2–CNT) has been performed with the help of isothermal hydroxylation technique and confirmed through typical microstructural and morphological characterizations. Thereafter, the effect of zirconia of mechanical and thermal properties of PP matrix composites has been studied through comparing the thermal decomposition behaviour, tensile and thermomechanical properties of pure PP, MWCNT-reinforced PP composite and ZrO2–CNT-reinforced PP hybrid composite. In short, the addition of 5 wt% CNTs improved tensile modulus by 22%, tensile strength by 16% and storage modulus by 45%, while the addition of same amount of ZrO2–CNT improved the above sequenced properties by 44, 47 and 73%, respectively. Moreover, ZrO2–CNT/PP hybrid composite has been found to have better thermally stability than pure PP as well as CNT/PP composite.

In this study, we describe an experimental investigation on synthesis and characterization of silicon carbide (SiC) particles encapsulated with MgO (magnesium oxide) and nanocrystalline MgAl2O4 spinel (magnesium aluminate), respectively through sol− gel route, a facile technique. Synthesized microcomposites were comprehensively examined by various characterization techniques like FE-SEM (Field emission scanning electron microscopy), XRD (X-Ray diffraction) and TEM (Transmission electron microscopy), respectively. Elemental mapping and X-ray energy dispersion spectroscopy (EDX) associated with high-resolution SEM provided the specific amount of shell materials. Furthermore, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) examination was conducted for the MgO encapsulated SiC and MgAl2O4 encapsulated SiC microcomposites. The synthesized encapsulated SiC with MgAl2O4 spinel is having a better catalytic ability and show higher peak currents compared to MgO decorated SiC and pristine SiC. The results obtained from EIS and CV testing demonstrate that synthesized microcomposites can be applied as an active material for supercapacitors, fuel cells, electronic devices, electrodes and unique reinforcing materials in other metal as well as polymer matrix, respectively.

In this present work mathematical and numerical analysis are carryout to determine the existence of Ledinegg and dynamic instability phenomena in a rectangular shape of natural circulation loop at supercritical condition using supercritical water as a working fluid. A mathematical model has been developed based on the thermal hydraulic (TH) conversion equations of mass, energy and momentum with and without considering the heating structure. Then this dimensional mathematical model has been validated with the SPORT and SUCLIN benchmark model. A rectangular shape with constant diameter of supercritical water natural circulation (RSCWNCL) is investigated and various simulations are performed to find a threshold stability boundary (TSB) at supercritical conditions. Numerical simulations have been carried out to determine the effect of inlet pressure, hydraulic loop diameter and loop riser height on the Ledinegg instability.

This work enlightens the effect of three different derivatives of graphene on mechanical, thermal and rheological properties of acrylonitrile-butadiene-styrene (ABS) composites prepared via melt-mixing technique. These nanofillers i.e. graphene oxide (GO), chemically reduced graphene oxide (rGO-C) and thermally reduced graphene oxide (rGO-Th), with selective low percolation threshold in ABS, brought erratic outcome. It has been noticed that rGO-C acts as better reinforcement in ABS than other derivatives. Improvement in tensile strength by 1.8-fold, storage modulus by 12% and glass transition by 11 °C has been achieved with rGO-C/ABS composites. Some typical secondary correlations based on dynamic storage modulus i.e. variations in stiffness, degree of entanglement and C-factor, have been used to exaggerate the change in dynamic properties more precisely. Creep and recovery behaviour, investigated at different environment temperatures and three different stress levels, also shown minimum creep deformation and superior recovery using rGO-C.

This work explores the effectiveness of nanoclay (NC) as compatibilizer in graphene oxide (GO) reinforced Nylon66 (N66) nanocomposites, prepared through melt mixing technique. Different composites have been prepared with varying concentration of NC to determine its optimum content for an effective improvement in thermomechanical properties of GO/N66 composites. XRD curves have shown that properly exfoliated nanocomposites have been synthesized with the use of NC as secondary filler. FTIR has been used to confirm presence of different elements and the nature of interaction between N66 and fillers. Thermogravimetric analysis have shown that the effect of GO and NC on thermal decomposition behaviour of GO/N66 composites is insignificant. The mechanical and thermomechanical properties of these composites have been studied with the help of tensile tests, flexural tests and dynamic mechanical analysis. The incorporation of 2 wt% NC in GO-N66 nanocomposite shows most significant improvement in its tensile and flexural strength (93.2% and 121.5%, respectively). DMA studies revealed improvement in storage modulus of GO-NC reinforced hybrid composites. Glass transition (T g ) of 2NC-GO-N66 nanocomposite have been noticed to improve by 12.5%. FESEM images have shown that agglomeration of nanoparticles takes place when the content of NC reaches 3 wt%. This provides the reason for poor mechanical and thermomechanical properties of the composite having NC more than 2 wt%.

In this work, the effect of nanoclay in carbon black reinforced PC-PBT has been investigated on the basis of changes in their mechanical and thermal properties. It has been believed on the basis of FESEM images that CB supports for the expansion of PBT rods and PC wraps around these expanded rods. However, the effect of reinforcing filler for improvement in mechanical properties has been found insignificant which may be due to the agglomeration of reinforcing particles. Addition of nanoclay in carbon black reinforced PC-PBT composite blend shown considerable improvement in its tensile strength (113%). This should be due to the improved dispersion of CB in polymer matrix and better linked-up structure of PBT rods after addition of NC. In addition, this combination has shown simultaneous improvement in tensile strength and ductility which is unusual and may be desirable in many structural applications.

In this work a numerical investigation is performed to analyze a rectangular supercritical water natural circulation loop (R-SCWNCL) from thermal-hydraulic point of view with the specific work to predict Ledinegg instability and dynamic instability in a rectangular shape supercritical water natural circulation loop using a thermal–hydraulic model which is based on nonlinear mass, axial momentum and energy conservation equations. The thermal–hydraulic (TH) model has been validated against a result available in the literature. A SCWNCL of rectangular shape is analyzed and numerical simulations are carried out to obtain a marginal stability zone (MSZ) in its operating regime and relevant system. Further parametric studies have been performed to find out the impact of loop riser height (loop height), loop diameter and system pressure on the Ledinegg instability.

We have studied the growth of multiwall carbon nanotubes (CNTs), using graphene oxide (GO) and iron nanoparticles as catalyst for chemical vapor deposition (CVD) technique. This approach is based on covalent bonding between GO and acetylene (C 2 H 2 ) gas molecules. Catalytic layers of GO and iron nanoparticles were fabricated on copper substrate using spin coater. Main reactions took place in CVD chamber under atmospheric pressure at 750 °C. Field emission scanning electron microscope (FESEM) explored the diameter distribution of successfully synthesized CNTs: 10–20 nm for GO and 29–47 nm for iron nanoparticles. X-ray diffraction spectra confirmed the presence of synthesized CNTs on both catalysts, as well as transformation of GO to reduced graphene oxide (rGO) during this process. I D /I G ratio was obtained through Raman spectroscopy, which revealed less defect contents in CNTs synthesized on GO in comparison to nanotubes grown iron catalyst. The main advantages of this innovative approach are simplicity, low cost due to one step technique, high yield and less defects.

In this work, antibacterial, micro-structural, and fluorescence properties of silver (Ag) doped TiO2 nanoparticles were studied to analyze the effect of silver for effective improvement in antibacterial properties of TiO2. Antibacterial properties of pure TiO2 and Ag-TiO2 was studied using Escherichia coli, Pseudomonas aeruginosa as Gram Negative and Bacillus subtilis, Staphylococcus aureus as Gram positive bacteria, as a model for Agar disc diffusion assay method. The concept of inhibition zone diameter was applied to observe the antibacterial activity of TiO2 and Ag-TiO2. It was observed that the antibacterial activity of TiO2 improves with doping of Ag. Fluorescence spectra confirm the red shift in band edge emission at excitation wavelength of 360 nm which shows effective fluorescence properties of these nanoparticles. Microstructures of these nanoparticles have studied with the help of transmission electron microscopy (TEM) and atomic force microscopy (AFM).

Wheat leaf rust, caused by Puccinia triticina Eriks., is of worldwide concern for wheat producers. The disease has been an annual problem for Canadian wheat producers since the early days of wheat cultivation in the 1800s, and research focused on combating this disease began in the early 1900s. Significant progress was made towards understanding the epidemiology of wheat leaf rust and developing genetic resistance in many countries worldwide. This review paper focuses exclusively on the research and development done in whole, or in part, in Canada. An integrated approach to controlling wheat leaf rust consisted of research in the following areas: the early research on wheat leaf rust in Canada, breeding and commercialization of high quality rust resistant wheat cultivars, discovery and genetic analysis of leaf rust resistance genes, the population biology and genetics of the P. triticina/wheat interaction. This review summarizes the research in each of these areas and the connections between the d...

In this work, graphene oxide (GO) has been prepared through three different processes namely, eco-friendly Hummers method, modification in improved Hummers method and a new approach. This new approach has been designed by changing some processing parameters and intercalating agent for significant reduction in processing time and to improve the quantity of GO in comparison to the other two methods. This has been achieved through better oxidization of graphite using nitric–sulfuric acid (HNO3–H2SO4) as intercalating agent. X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, Atomic Force Microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV–visible spectroscopy, and Thermogravimetric analysis (TGA) are used to characterize the GO prepared through different processes. These characterizations have confirmed an improved exfoliation of graphite, using addition of HNO3 in intercalating agent, in a short processing time and bring on higher yield of GO via this new process.

Strong interfacial bonding is necessary between carbon fiber and polymer matrix to take advantage of carbon fiber-reinforced polymer composites in structural applications. An attempt has been made to improve the interfacial bonding by coating coiled carbon nanotubes on carbon fiber surface through a single-step chemical vapor deposition process. Coiled structures were synthesized on nickel-coated carbon fiber by using thiophene as a sulphur impurity and acetylene as a carbon precursor. The coiled carbon nanotube-coated carbon fiber and epoxy were used, respectively, as the reinforcement and the matrix to form carbon fiber-reinforced polymer composites. The role of coiled carbon nanotubes on thermo-mechanical properties of carbon fiber-reinforced polymer composites was investigated using dynamic mechanical thermal analysis in three different modes of deformation. Unsized carbon fiber (carbon fiber heat-treated to remove sizing agents)/epoxy composites were used as the reference to evaluate the enhancement due to coiled carbon nanotubes. Substantial improvements in viscoelastic properties of coiled carbon nanotube/carbon fiber/polymer composites over unsized carbon fiber/polymer composites were observed in all of the deformation modes. Coiled Carbon nanotube composites in shear mode exhibit highest enhancements in both storage as well as loss moduli due to superior mechanical interlocking between coiled carbon nanotubes and polymer matrix.

Vibration welding technique has been used to study the weld zone of thermoplastic polymers using ABS (amorphous), PC (amorphous), PMMA (amorphous), and PBT (semicrystalline). Polymers were welded using alike components and combinations of semicrystalline polymer with different amorphous polymers. Mechanical testing of welded polymers has proved that the tensile strength, elongation at break, and deformation was highest for PC–PC weld and least for ABS–ABS weld, when alike polymers were welded. However, welding of semicrystalline and amorphous polymer shows enormous reduction in its tensile strength as well as other tensile properties. Also, the tensile fracture of PBT with other amorphous polymers always occurred at weld zone which was not always in case of alike polymer welds. The weld strength of these polymers was observed to be dependent on the mechanical interlocking among the layers and not on interfacial bonding. This phenomenon may be due to the difference in glass transition temperatures of semic...

Graphene oxide based nanocomposites were prepared through the in situ polymerization of aniline and pyrrole to study the interaction of graphene oxide with polyaniline (PANI) and polypyrrole (PPy). Field emission scanning electron microscopy (FESEM) was used to study the surface morphology and transmission electron microscopy (TEM) for the qualitative understanding of the internal structure of PANI/PPy coating on GO. The chemical structures of composites were studied through X-ray photoelectron spectroscopy (XPS) analysis. It was observed that specific capacitance of PPy coated GO improved by ∼122.73% compared to pristine GO. Moreover, the binding energy of polypyrrole–graphene oxide was found to be higher than polyaniline–graphene oxide because of the absence of oxygen containing functional groups. In addition, the storage capacity was effectively improved due to the synergistic effect of polypyrrole coating on graphene oxide.

Over the past several years, RNA interference (RNAi) has emerged as a powerful genetic tool that is being exploited not only in fundamental research for the assessment of gene functions, but also in various fields of applied research in medicine and agriculture. In plants, RNAi strategies have the potential to allow manipulation of various aspects of food quality and nutritional content, but also for plant protection. In the study of plant-fungus interactions, a comprehensive understanding of pathogenic mechanisms based on information from genome sequences demands advanced genomics tools and infrastructure. In order to make use of the plethora of information yielded by the rapidly increasing fungal pathogen genome sequencing studies, there is a growing need to achieve gene function assessment amenable to high-throughput techniques. Targeted gene disruption is effective but may not be feasible in certain fungi because of lack of transformation protocols or their life styles. RNAi techniques offer an alternative but, in contrast to other biological systems, only few studies have reported the use of RNAi to explore gene function in plant pathogenic fungi. In this review, we summarize a variety of options using RNAi techniques that have become available to study gene function for high-throughput phenotypic screening of virulence and pathogenicity factors in plant fungi. The identification of such genes can be exploited for the protection of crops against fungal pathogens.

Cereal rust fungi are destructive pathogens, threatening grain production worldwide. Targeted breeding for resistance utilizing host resistance genes has been effective. However, breakdown of resistance occurs frequently and continued efforts are needed to understand how these fungi overcome resistance and to expand the range of available resistance genes. Whole genome sequencing, transcriptomic and proteomic studies followed by genome-wide computational and comparative analyses have identified large repertoire of genes in rust fungi among which are candidates predicted to code for pathogenicity and virulence factors. Some of these genes represent defence triggering avirulence effectors. However, functions of most genes still needs to be assessed to understand the biology of these obligate biotrophic pathogens. Since genetic manipulations such as gene deletion and genetic transformation are not yet feasible in rust fungi, performing functional gene studies is challenging. Recently, Host-induced gene silencing (HIGS) has emerged as a useful tool to characterize gene function in rust fungi while infecting and growing in host plants. We utilized Barley stripe mosaic virus-mediated virus induced gene silencing (BSMV-VIGS) to induce HIGS of candidate rust fungal genes in the wheat host to determine their role in plant-fungal interactions. Here, we describe the methods for using BSMV-VIGS in wheat for functional genomics study in cereal rust fungi.

Cereal rust fungi are destructive pathogens, threatening grain production worldwide. Targeted breeding for resistance utilizing host resistance genes has been effective. However, breakdown of resistance occurs frequently and continued efforts are needed to understand how these fungi overcome resistance and to expand the range of available resistance genes. Whole genome sequencing, transcriptomic and proteomic studies followed by genome-wide computational and comparative analyses have identified large repertoire of genes in rust fungi among which are candidates predicted to code for pathogenicity and virulence factors. Some of these genes represent defence triggering avirulence effectors. However, functions of most genes still needs to be assessed to understand the biology of these obligate biotrophic pathogens. Since genetic manipulations such as gene deletion and genetic transformation are not yet feasible in rust fungi, performing functional gene studies is challenging. Recently, Host-induced gene silencing (HIGS) has emerged as a useful tool to characterize gene function in rust fungi while infecting and growing in host plants. We utilized Barley stripe mosaic virus-mediated virus induced gene silencing (BSMV-VIGS) to induce HIGS of candidate rust fungal genes in the wheat host to determine their role in plant–fungal interactions. Here, we describe the methods for using BSMV-VIGS in wheat for functional genomics study in cereal rust fungi., Series: Methods in Molecular Biology; no. 1659

Summary Leaf rust, caused by the pathogenic fungus Puccinia triticina (Pt), is one of the most serious biotic threats to sustainable wheat production worldwide. This obligate biotrophic pathogen is prevalent worldwide and is known for rapid adaptive evolution to overcome resistant wheat varieties. Novel disease control approaches are therefore required to minimize the yield losses caused by Pt. Having shown previously the potential of host‐delivered RNA interference (HD‐RNAi) in functional screening of Pt genes involved in pathogenesis, we here evaluated the use of this technology in transgenic wheat plants as a method to achieve protection against wheat leaf rust (WLR) infection. Stable expression of hairpin RNAi constructs with sequence homology to Pt MAP‐kinase (PtMAPK1) or a cyclophilin (PtCYC1) encoding gene in susceptible wheat plants showed efficient silencing of the corresponding genes in the interacting fungus resulting in disease resistance throughout the T2 generation. Inhibition of Pt proliferation in transgenic lines by in planta‐induced RNAi was associated with significant reduction in target fungal transcript abundance and reduced fungal biomass accumulation in highly resistant plants. Disease protection was correlated with the presence of siRNA molecules specific to targeted fungal genes in the transgenic lines harbouring the complementary HD‐RNAi construct. This work demonstrates that generating transgenic wheat plants expressing RNAi‐inducing transgenes to silence essential genes in rust fungi can provide effective disease resistance, thus opening an alternative way for developing rust‐resistant crops.

This chapter is intended to realize the positive aspects of blending and use of fillers in rubber matrices. Although these are very old techniques on which a lot of literature is available, some recent studies have brought out important and exciting facts through integrating both processes. The advancement towards newer nanofillers having promising multidirectional properties invites researchers to explore the effect of these materials in rubber/rubber and rubber/plastic blends. To proceed in this direction it is really important to provide a common platform which clears up the physical significance of rubber blend nanocomposites. So, in this review we have included some past and recent works to clarify the need of rubber blend nanocomposites and the requirements for their further investigation. In addition, this study provides an overview for the suitability of different rubber nanocomposites for a better product specific utilization.

Thermomechanical stability of polymer nanocomposites plays a vital role in studying the molecular mobility transitions under varying temperatures. In this regard, dynamic mechanical analysis (DMA) explores the viscoelastic properties, i.e., storage modulus, loss modulus, and damping factor, of polymer-based nanocomposites. Commonly, because of the higher stiffness of fillers, storage modulus has been noticed to improve after the addition of nanofillers, while damping behavior shows reduced performance caused by restrictions in the movement of polymer chains. The main purpose of DMA in clay–polymer nanocomposites is to recognize thermodynamic interactions between its components, i.e., matrix and filler. A number of existing studies have shown that clay acts as a good compatibilizer for better dispersion of carbon-based fillers/nanofillers in polymer matrices and have reported the effectiveness of their findings with the help of thermomechanical properties of such composites. This chapter is designed to show the importance of this technique for further research related to clay-reinforced polymer blends/nanocomposites and to locate the key aspects for its precise investigation.

The arch-shaped single electrode based triboelectric nanogenerator (TENG) is fabricated using thin film of reduced graphene oxide nanoribbons (rGONRs) with polyvinylidene fluoride (PVDF) polymer used as binder to effectively convert mechanical energy into electrical energy. The incorporation of rGONRs in PVDF polymer enhances average surface roughness of rGONRs/PVDF thin film. With the combination of the enhancement of average roughness and production of functional groups, which indicate improve charge storage capacity of prepared film. Furthermore, the redox peaks obtained through cyclic voltammetry were identified more in rGONRs/PVDF composite in comparison to pristine rGONRs to confirm charge transfer capability of film. Herein, the output performance was discussed experimentally as well as theoretically, maximum voltage was obtained to be 0.35 V. The newly designed TENG to harvest mechanical energy and opens up many new avenues of research in the energy harvesting applications.

Rust fungi are devastating plant pathogens and several Puccinia species have a large economic impact on wheat production worldwide. Disease protection, mostly offered by introgressed host-resistance genes, is often race-specific and rapidly overcome by newly-emerging virulent strains. Extensive new genomic resources have identified vital pathogenicity genes but their study is hampered because of the biotrophic life styles of rust fungi. In cereals, Barley stripe mosaic virus (BSMV)-induced RNAi has emerged as a useful tool to study loss-of-function phenotypes of candidate genes. Expression of pathogen-derived gene fragments in this system can be used to obtain in planta-generated silencing of corresponding genes inside biotrophic pathogens, a technique termed host-induced gene silencing (HIGS). Here we test the effectiveness of BSMV-mediated HIGS in the wheat leaf rust fungus Puccinia triticina (Pt) by targeting three predicted pathogenicity genes, a MAPK, a cyclophilin, and a calcineurin regulatory subunit. Inoculation of BSMV RNAi constructs generated fungal gene-specific siRNA molecules in systemic leaves of wheat plant. Subsequent Pt inoculation resulted in a suppressed disease phenotype and a reduction in endogenous transcript levels of the targeted fungal genes indicating translocation of siRNA molecules from host to fungal cells. Efficiency of this host-generated trans-specific RNAi was enhanced by using BSMV silencing vectors defective in coat protein coupled with introducing fungal gene sequences simultaneously in sense and antisense orientation. The disease suppression indicated the likely involvement of these fungal genes in pathogenicity. This study demonstrates that BSMV-mediated in planta-generated RNAi is an effective strategy for functional genomics in rust fungi.

Three members of the Puccinia genus, Puccinia triticina (Pt), P. striiformis f.sp. tritici (Pst), and P. graminis f.sp. tritici (Pgt), cause the most common and often most significant foliar diseases of wheat. While similar in biology and life cycle, each species is uniquely adapted and specialized. The genomes of Pt and Pst were sequenced and compared to that of Pgt to identify common and distinguishing gene content, to determine gene variation among wheat rust pathogens, other rust fungi, and basidiomycetes, and to identify genes of significance for infection. Pt had the largest genome of the three, estimated at 135 Mb with expansion due to mobile elements and repeats encompassing 50.9% of contig bases; in comparison, repeats occupy 31.5% for Pst and 36.5% for Pgt. We find all three genomes are highly heterozygous, with Pst [5.97 single nucleotide polymorphisms (SNPs)/kb] nearly twice the level detected in Pt (2.57 SNPs/kb) and that previously reported for Pgt. Of 1358 predicted effectors in Pt, 784 were found expressed across diverse life cycle stages including the sexual stage. Comparison to related fungi highlighted the expansion of gene families involved in transcriptional regulation and nucleotide binding, protein modification, and carbohydrate degradation enzymes. Two allelic homeodomain pairs, HD1 and HD2, were identified in each dikaryotic Puccinia species along with three pheromone receptor (STE3) mating-type genes, two of which are likely representing allelic specificities. The HD proteins were active in a heterologous Ustilago maydis mating assay and host-induced gene silencing (HIGS) of the HD and STE3 alleles reduced wheat host infection., Supplemental files are available on the publisher's website