Comparative e-waste plastics biodegradation efficacy of monoculture Pseudomonas aeruginosa strain PE10 and bacterial consortium under in situ condition

A significant amount of electronic obsoletes or electronic waste (e-waste) is being generated globally each year; of these, ~20% of obsolete electronic items have plastic components. Current remediation practices for e-waste have several setbacks due to its negative impact on the environment, agro-ecosystem, and human health. Therefore, comparative biodegradation studies of e-waste plastics by monoculture Pseudomonas aeruginosa strain PE10 and bacterial consortium consisting of Achromobacter insolitus strain PE2 (MF943156), Acinetobacter nosocomialis strain PE5 (MF943157), Pseudomonas lalkuanensis PE8 (CP043311), and Stenotrophomonas pavanii strain PE15 (MF943160) were carried out in situ. Biological treatment of e-waste with these candidates in soil ecosystems has been analyzed through diversified analytical techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric-derivative thermogravimetry-differential thermal analysis (TG-DTG-DTA), and scanning electron microscopy (SEM). Both P. aeruginosa strain PE10 and the bacterial consortium have a tremendous ability to accelerate the biodegradation process in the natural environment. However, FTIR analysis implied that the monoculture had better efficacy than the consortium, and it was consistent until the incubation period used for the study. Some polymeric bonds such as ν C=C and δ C-H were completely removed, and ν C=C ring stretching, νasym C–O–C, νsym C–H, etc. were introduced by strain PE10. Furthermore, thermal analysis results validated the structural deterioration of e-waste as the treated samples showed nearly two-fold weight loss (WL; 6.8%) than the untreated control (3.1%) at comparatively lower temperatures. SEM images provided the details of surface disintegrations. Conclusively, individual monoculture P. aeruginosa strain PE10 could be explored for e-waste bio-recycling in agricultural soil ecosystems thereby reducing the cost, time, and management of bioformulation in addition to hazardous pollutant reduction

Cucurbita plants: From farm to industry

The Cucurbita genus, a member of Cucurbitaceae family, also known as cucurbits, is native to the Americas. Genus members, like Cucurbita pepo and Cucurbita maxima, have been used for centuries in folk medicine for treating gastrointestinal diseases and intestinal parasites. These pharmacological effects are mainly attributed to their phytochemical composition. Indeed, Cucurbita species are a natural source of carotenoids, tocopherols, phenols, terpenoids, saponins, sterols, fatty acids, functional carbohydrates, and polysaccharides, that beyond exerting remarkable biological effects, have also been increasingly exploited for biotechnological applications. In this article, we specifically cover the habitat, cultivation, phytochemical composition, and food preservative abilities of Cucurbita plants.This work was supported by CONICYT PIA/APOYO CCTE AFB170007. N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the Strategic project ref. UID/BIM/04293/2013 and “NORTE2020-Northern Regional Operational Program” (NORTE-01-0145-FEDER-000012)

Synthesis and Characterization of Monodispersed Copper Colloids in Polar Solvents

A chemical reduction method for preparing monodispersed pure-phase copper colloids in water and ethylene glycol has been reported. Owing to the reduction property of ethylene glycol, the reaction rate in ethylene glycol is higher than that in water. In addition, the amount of reducing agent can be reduced largely. Ascorbic acid plays roles as reducing agent and antioxidant of colloidal copper, due to its ability to scavenge free radicals and reactive oxygen molecules. Thermogravimetric results reveal that the as-prepared copper nanoparticles have good stability, and they begin to be oxidized at above 210 °C. Polyvinyl pyrrolidone works both as size controller and polymeric capping agents, because it hinders the nuclei from aggregation through the polar groups, which strongly absorb the copper particles on the surface with coordination bonds

Enhanced performance of pyroelectric microsensors through the introduction of nanoporosity

Sol-gel process has successfully been applied for the deposition of porous PbZrxTi1-xO3 (x = 0.45, 0.15) thin films on platinized silicon wafers. Addition of a polymer as a volatile phase to the precursor sol prior to spin coating has been proved an excellent method to synthesize PZT-porous films. Introduction of pores creates a matrix void composite resulting in high figures of merit for pyroelectric applications. The dielectric constant was found to be strongly dependent to the porosity, whereas the pyrocoefficient changes moderately with porosity. The relative permittivity can be decreased down to 150 and 95 for PZT films with Zr/Ti ratio of 45/55 and 15/85 respectively, and the figures of merit F-v and F-d values for PZT (Zr/Ti= 15/85) films can be increased up to 1.95 and 139 muC/m(2) K, respectively by incorporating a nanoporous structure in films. (C) 2003 Elsevier Ltd. All rights reserved

In-plane integration of polymer microfluidic channels with optical waveguides - a preliminary investigation

The next major challenges for lab-on-a-chip (LoC) technology are 1) the integration of microfluidics with optical detection technologies and 2) the large-scale production of devices at a low cost. In this paper the fabrication and characterisation of a simple optical LoC platform comprising integrated multimode waveguides and microfluidic channels based on a photo-patternable acrylate based polymer is reported. The polymer can be patterned into both waveguides and microfluidic channels using photolithography. Devices are therefore both quick and cost-effective to fabricate, resulting in chips that are potentially disposable. The devices are designed to be highly sensitive, using an in-plane direct excitation configuration in which waveguides intersect the microfluidic channel orthogonally. The waveguides are used both to guide the excitation light and to collect the fluorescence signal from the analyte. The potential of the device to be used for fluorescence measurements is demonstrated using an aqueous solution of sodium fluorescein. A detection limit of 7 nM is achieved. The possibilities offered by such a device design, in providing a cost-effective and disposable measurement system based on the integration of optical waveguides with LoC technology is discussed

Pyroelectric nanoporous films: Synthesis and properties

PbZrxTi1-xO3 (x=0.45) and PbxCa1-xTiO3 (PCT) (x=0.75) porous thin films were deposited on platinized silicon wafers by chemical solution deposition route using a polymer as a volatile phase. The introduction of pores creates a matrix-void composite resulting in a high figure of merit for pyroelectric applications. The figures of merit F-v and F-d for PCT films are shown to be as high as 4.8 and 250 muC/m(2) K, respectively. (C) 2002 American Institute of Physics

Piezoelectric response and polarization switching in small anisotropic perovskite particles

A hydrothermal processing route was used to produce anisotropic submicrometer particles of potassium niobate-tantalates and pure potassium niobate. Piezoelectric activity, switching polarization, and piezoelectric hysteresis loops were observed in these ferroelectric perovskite nanorods by means of AFM assisted detection of induced piezoelectric vibrations. Both lattice and domain wall contributions to the piezoelectric response were evidenced

Properties of chemical solution deposited polycrystalline neodymium-modified Bi4Ti3O12

Thin films of neodymium-modified bismuth titanate Bi3.44Nd0.56Ti3O12 (BNT) were grown on Pt/TiO2/SiO2/Si substrates using chemical solution deposition method. The capacitors made by applying top Au electrodes on BNT films showed significantly improved values of the remanent polarization as compared to that using bismuth titanate Bi4Ti3O12 (BT) films. The 2P(r) value for the BNT capacitors was determined to be equal to 38 muC/cm(2) at an applied voltage of 24 V, whereas, for Bi4Ti3O12 ( BT) capacitors a value of 20 muC/cm(2) was measured at the same applied voltage. The maximum piezoelectric and pyroelectric coefficients of 22 pm/V and 112 muC/m(2) K respectively, were measured for the BNT thin films