Different biological methods are gaining recognition for the production of silver nanoparticles (Ag-NPs) due to their multiple applications. The use of plants in the green synthesis of nanoparticles ...emerges as a cost effective and eco-friendly approach. In this study the green biosynthesis of silver nanoparticles using Callicarpa maingayi stem bark extract has been reported. Characterizations of nanoparticles were done using different methods, which include; ultraviolet-visible spectroscopy (UV-Vis), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDXF) spectrometry, zeta potential measurements and Fourier transform infrared (FT-IR) spectroscopy. UV-visible spectrum of the aqueous medium containing silver nanoparticles showed absorption peak at around 456 nm. The TEM study showed that mean diameter and standard deviation for the formation of silver nanoparticles were 12.40 ± 3.27 nm. The XRD study showed that the particles are crystalline in nature, with a face centered cubic (fcc) structure. The most needed outcome of this work will be the development of value added products from Callicarpa maingayi for biomedical and nanotechnology based industries.
Lepidopteran insect pest Helicoverpa armigera is one of the most destructive pests of crop plants and several biotechnological approaches are being developed for its control. Plant defensins are ...small cationic and cysteine-rich peptides that play a role in plant defense. Ingestion of a defensin from Capsicum annuum (CanDef-20) induced a dose-dependent reduction in larval and pupal mass, delayed metamorphosis and also severely reduced fecundity and fertility in H. armigera. To understand the molecular mechanisms of CanDef-20 ingestion-mediated antibiosis in H. armigera larvae, a comparative transcriptomics analysis was carried out. Predominant downregulation of GOs represents serine-type endopeptidases, structural constituents of ribosomes and integral membrane components and differential upregulation of ATP binding, nucleus and translation, while up-regulation of nucleic acid binding represented by transposable elements, were detected. Different isoforms of lipase, serine endopeptidase, glutathione S-transferase, cadherin, alkaline phosphatase and aminopeptidases were found to be upregulated as a compensatory response to CanDef-20 ingestion. In vitro enzyme assays and qPCR analysis of some representative genes associated with vital cellular processes like metamorphosis, food digestion and gut membrane indicated adaptive differential regulations in CanDef-20 fed H. armigera larvae. We conclude that CanDef-20 ingestion affects insect metabolism in a number of ways through its interaction with cell membrane, enzymes, cytoplasmic proteins and triggering transposon mobilization which are linked to growth retardation and adaptive strategies in H. armigera.
Aneuploid genomes, characterized by unbalanced chromosome stoichiometry (karyotype), are associated with cancer malignancy and drug resistance of pathogenic fungi. The phenotypic diversity resulting ...from karyotypic diversity endows the cell population with superior adaptability. We show here, using a combination of experimental data and a general stochastic model, that the degree of phenotypic variation, thus evolvability, escalates with the degree of overall growth suppression. Such scaling likely explains the challenge of treating aneuploidy diseases with a single stress-inducing agent. Instead, we propose the design of an “evolutionary trap” (ET) targeting both karyotypic diversity and fitness. This strategy entails a selective condition “channeling” a karyotypically divergent population into one with a predominant and predictably drugable karyotypic feature. We provide a proof-of-principle case in budding yeast and demonstrate the potential efficacy of this strategy toward aneuploidy-based azole resistance in Candida albicans. By analyzing existing pharmacogenomics data, we propose the potential design of an ET against glioblastoma.
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•Higher stress leads to larger phenotypic variation in heterogeneous aneuploids•Eradication of aneuploids via dual-stress application: “evolutionary trap” (ET)•The first stress selects for a less diverse population; the second targets it•ET may be applicable toward azole resistance in Candida albicans and human cancer
The heterogeneity of aneuploid cell populations increases with stress, causing resistance to emerge. An eradication strategy involves sequential applications of stress: the first stress homogenizes the population via adaptation, and the second specifically targets and eliminates the newly dominant karyotype.
In this paper, a new approach for interpreting raw pulsed electroacoustic (PEA) signals is proposed. The theory behind acoustic wave propagation in ideal (no attenuation and no dispersion) materials ...and in real materials (with attenuation and dispersion) initially free of space charge is described. A simulation model has been developed for the following: (1) the acoustic signal formation in the PEA apparatus, the transmission of the acoustic waves, their attenuation/dispersion and detection; (2) the instrumental effects of having a capacitive piezoelectric sensor driving a 50 Ω input impedance amplifier. The various layers of a PEA system were considered in the model and the effect of each layer on the acoustic wave propagation is analyzed. Since the model allowed raw PEA data to be simulated, it can be used to identify potential sources of error in interpreting real PEA measurement data, such as acoustic mismatch between PEA layers, electrode material effects, pulse voltage, etc. The results showed good agreement between the simulated and experimentally obtained data in the case of space charge free samples.
•Evaluation of rooftop PV installations at 2 Kuwaiti schools was carried out.•Lack of real plants data in the region and specifically Kuwait motivated the work.•Automated cleaning system allowed for ...minimization of soiling loss.•The average PV system performance was greater than 76%.•Schools show high potential for rooftop installations.
Photovoltaic (PV) is a high-potential renewable energy technology for Kuwait to pursue due to high daily irradiation, and has garnered local attention in recent years due to the growing energy demand and concerns over climate change. As yet, no data are available regarding the actual performance of PV systems in Kuwait’s harsh environment. This paper presents a 12-month-long performance evaluation of the first 85.05kWp and 21.6kWp copper indium gallium selenide (CIGS) thin film, grid-connected PV systems on the rooftops of two schools. The schools’ monthly energy consumption and PV generation profiles, the actual performance of the PV plants, the effectiveness of automated cleaning systems on the power output, and the benefits of PV implementation in schools were analyzed and evaluated. Data analysis was applied to filter and normalize the data in order to identify the actual performance parameters. The findings of the study, based on solar irradiation collected, the performance of the module technology and the effectiveness of the automated cleaning systems, show that the performance ratio was maintained between 0.74 and 0.85. Furthermore, the minimum monthly energy yield of the PV systems was about 104kWh/kWp. The annual average daily final yields of the PV systems in this study were 4.5kWh/kWp/day. The results provided insight into the performance of CIGS grid-connected PV systems in Kuwait, and those data will be beneficial to the PV research community worldwide. School buildings, particularly for the rooftops, are a unique and important asset for urban PV system implementation, because they provide a combination of relatively large, unused, suitable areas, which would make distributed and effective solar power generation possible on the national level.
The present work reports quantitative planar imaging of Nitric Oxide (NO) concentration in a dilute spray flame at atmospheric pressure, contributing to CORIA Rouen Spray Burner (CRSB) database. Mean ...NO mole fraction (χNO) is measured using planar laser-induced fluorescence (PLIF) technique, while the flame front is located simultaneously using OH-PLIF. An optimum NO excitation scheme is selected to minimize temperature-quenching dependence based on LIF simulations. Furthermore, the temperature and collisional quenching effects on NO fluorescence are corrected by using the temperature and gas composition obtained from large eddy simulation performed in previous work Proc. Combust. Inst., 36 (2017), 2567-2575. Additionally, interference in NO-PLIF from polycyclic aromatic or unburned hydrocarbon fluorescence is corrected by detuned (NO off-transition) signal subtraction. The spatial distribution of χNO is discussed in the context of a spray flame topology, which exhibits two distinct branches. The results suggest the formation of prompt NO on the inner composite branch (fuel-lean and non-premixed) and thermal NO on the outer pure non-premixed branch. χNO at 60 mm height above burner measures 33 ppm near the inner branch, and 75 ppm around the outer branch.
Nanoparticles have wide applications in various fields due to their small size. Titanium dioxide nanoparticles are bright with high refractive index (n = 2.4) which makes them suitable for industry ...dealing with toothpaste, pharmaceuticals, coatings, papers, inks, plastics, food products, cosmetics and textile. Three crystalline phases of titanium dioxide, are anatase (tetragonal), rutile (tetragonal), and brookite (orthorhombic) in which brookite has no commercial value. Due to their self cleaning and antifogging property, they are used in the preparation of cloths, windows, tiles and anti-fogging car mirrors. Titanium dioxide nanoparticles also serve as environment sanitizing agent. Sol–gel route, flame hydrolysis, co-precipitation, impregnation and chemical vapor deposition like techniques are used for the synthesis of TiO
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nanoparticles. Biosynthesis of titanium dioxide nanoparticles has gained wide interest among researchers due to its cost effective, eco-friendly and reproducible approach. The sol–gel route remediation of the titanium dioxide from the environment is an important step and it can be achieved by using physical processes like sedimentation and filtration. The biosynthesis of titanium dioxide nanoparticles can be used in comparison to chemical synthesis. The titanium dioxide nanoparticles have wide applications, viz., reducing toxicity of dyes and pharmaceutical drugs; waste water treatment; reproduction of silkworm; space applications; food industries; etc., and so have immense industrial importance. The applications of nanoparticles synthesized by biological approach will be advantageous for the industries; environment and agriculture.
A high gain two-phase interleaved coupled inductor-based DC-DC converter step-up low input voltage sources like PV array and fuel cell in distribution generation system (DGS). The converter operates ...for a wide range of load changes when it is part of DGS. At light load, the converter operates in discontinuous conduction mode (DCM). A small-signal model (SSM) is required in both continuous conduction mode (CCM) and DCM to know the complete dynamic behavior of the converter. Steady-state and small-signal analysis of the two-phase interleaved coupled inductor boost converter (ICIBC) is quite complex when the converter operates in DCM. This paper presents the complete derivation of SSM of a two-phase ICIBC-based high step-up gain converter in DCM. The conditions of the converter operating in DCM are discussed. The small-signal model of two-phase ICIBC is derived using the state-space averaging method. The control-to-output voltage transfer function and steady-state voltage gain of the two-phase ICIBC are derived. When the converter operates in DCM, it eliminates the right half plane zero from the control-to-output voltage transfer function. Thus, it improves bandwidth and stability margin. Thus, single loop voltage control is sufficient to achieve regulated output voltage with faster response for all operating ranges of DCM. The laboratory prototype of two-phase ICIBC is implemented to step-up 24 V to 100 V at a power level of 300 W. The experimental results of two-phase ICIBC are obtained in DCM and CCM with step-change in load to validate the derived small-signal model.
In this study, epoxidized palm oil (EPO) was utilized as a plasticizer for polylactic acid (PLA) using chloroform as a solvent by solution casting process at six weight ratios of PLA/EPO, 95/05, ...90/10, 80/20, 70/30, 60/40, and 50/50, respectively. Fourier-transform infrared (FTIR) spectroscopy was used to identify the functional groups of PLA, EPO, and PLA/EPO blends. Thermal stability, mechanical, and morphological properties of the blends were investigated by thermogravimetric analyzer (TGA), tensile properties measurements, and scanning electron microscope (SEM) technique, respectively. The FTIR spectra indicate that there are some molecular interactions by intramolecular hydrogen bond between PLA and EPO. All sets of PLA/EPO blends show high thermal stability and significant improvement of mechanical properties compare to pure PLA. The highest elongation at break (about 210%) was obtained when the ratio of PLA/EPO blend was 80/20. Morphological results of PLA/EPO blends show that ESO was good miscible with PLA.
•A pilot system was developed for demand management of equipment in buildings.•The networking was based on LonWorks platform and power line communication.•Demand strategies led to load reductions up ...to 74% and energy savings up to 25%.•The peak load reduction is expected to reach 3.44GW by the year 2030.
Managing peak demand efficiently is vital for maintaining uninterrupted supply of electrical power by utility providers. In this work, a pilot system was developed for managing and controlling the demand of major power consuming equipment in buildings from a central server, while relying mostly on existing infrastructure and maintaining consumer comfort. The system was successfully demonstrated on a selected group of buildings using the LonWorks networking platform. At the building level, the system utilized power line and twisted pair communication to control the thermostats of air-conditioning (A/C) units. The higher level communication was executed through extensible markup language (XML) and simple object access protocol (SOAP). The system provided control capabilities based on A/C unit priority, thermostat temperature, building type and geographic location. The development and execution of demand management strategies for selected buildings led to peak load reductions up to 74%, in addition to energy savings up to 25%. Implementing such a system at a national level in Kuwait is estimated to reduce peak demand by 3.44GW, amounting to capital savings of $4.13 billion. The use of existing infrastructure reduced the cost and installation time of the system. Based on the successful testing of this pilot system, a larger-scale system is being developed.
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