Encapsulation of Synthesized Plant Growth Regulator Based on Copper(II) Complex in Chitosan/Alginate Microcapsules

A new copper complex, trans-diaqua-trans-bis [1-hydroxy-1,2-di (methoxycarbonyl) ethenato] copper (abbreviation Cu(II) complex), was synthesized and its plant growth regulation properties were investigated. The results show a sharp dependence of growth regulation activity of the Cu(II) complex on the type of culture and its concentration. New plant growth regulator accelerated the development of the corn root system (the increase in both length and weight) but showed a smaller effect on the development of the wheat and barley root systems. Stimulation of corn growth decreased with increasing Cu(II) complex concentration from 0.0001% to 0.01% (inhibition at high concentrations—0.01%). The development of corn stems was also accelerated but to a lesser extent. Chitosan-coated calcium alginate microcapsules suitable for delivery of Cu(II) complex to plants were prepared and characterized. Analysis of the FTIR spectrum showed that complex molecular interactions between functional groups of microcapsule constituents include mainly electrostatic interactions and hydrogen bonds. Microcapsules surface exhibits a soft granular surface structure with substructures consisting of abundant smaller particles with reduced surface roughness. Release profile analysis showed Fickian diffusion is the rate-controlling mechanism of Cu(II) complex releasing. The obtained results give new insights into the complexity of the interaction between the Cu(II) complex and microcapsule formulation constituents, which can be of great help in accelerating product development for the application in agriculture     

Distribution of vanadium and vanadyl porphyrins during fractionation of resins of heavy sulfurous oils

Features of the content and distribution of vanadium and vanadyl porphyrins in the fractions of resins, which were obtained by separation using column chromatography on silica, have been studied on heavy sulfurous oils of various deposits of the Volga–Ural basin (Russia). The difference of the vanadium and vanadyl porphyrin contents in the fractions of oils of various production complexes has been shown. Features of structural–group composition and predominant types of vanadyl porphyrins in the fractions of resins have been determined.     

Combining Multiple Cues for Visual Madlibs Question Answering

International Journal of Computer Vision - This paper presents an approach for answering fill-in-the-blank multiple choice questions from the Visual Madlibs dataset. Instead of generic and commonly...     

Psychological capital and self‐reported employee creativity: The moderating role of supervisor support and job characteristics

Although the positive effect of psychological capital (PsyCap) on employee performance is well documented, the conditions under which PsyCap exerts the most influence on creativity warrant further research. Complementing and extending prior studies, we theorize and examine how two critical contextual factors (supervisor support for creativity [SSC] and job characteristics) effectively activate PsyCap associated with self‐reported employee creativity. Drawing on an interactional perspective, we use trait activation theory to examine the moderating effects of SSC and job characteristics on the relationship between PsyCap and self‐reported employee creativity. Through rigorous hypotheses testing (N = 356 individuals from multiple industries in Chinese firms), our results demonstrate that both SSC and job characteristics positively moderate the PsyCap–creativity relationship. Additional analyses reveal that PsyCap is most effective at enhancing creativity when both SSC and job characteristics are high. Implications of these findings for theory, future research and practice are discussed.     

Elastic Gallium Phosphide Nanowire Optical Waveguides—Versatile Subwavelength Platform for Integrated Photonics

Emerging technologies for integrated optical circuits demand novel approaches and materials. This includes a search for nanoscale waveguides that should satisfy criteria of high optical density, small cross-section, technological feasibility and structural perfection. All these criteria are met with self-assembled gallium phosphide (GaP) epitaxial nanowires. In this work, the effects of the nanowire geometry on their waveguiding properties are studied both experimentally and numerically. Cut-off wavelength dependence on the nanowire diameter is analyzed to demonstrate the pathways for fabrication of low-loss and subwavelength cross-section waveguides for visible and near-infrared (IR) ranges. Probing the waveguides with a supercontinuum laser unveils the filtering properties of the nanowires due to their resonant action. The nanowires exhibit perfect elasticity allowing fabrication of curved waveguides. It is demonstrated that for the nanowire diameters exceeding the cut-off value, the bending does not sufficiently reduce the field confinement promoting applicability of the approach for the development of nanoscale waveguides with a preassigned geometry. Optical X-coupler made of two GaP nanowires allowing for spectral separation of the signal is fabricated. The results of this work open new ways for the utilization of GaP nanowires as elements of advanced photonic logic circuits and nanoscale interferometers.     

Variation of the Si/Al ratio in nanosized zeolite Beta crystals

Zeolite Beta nanocrystals were prepared from basic aluminosilicate precursor solutions upon hydrothermal treatment at 100 °C. The Si/Al ratio of the initial system was systematically changed from 25 to infinity in order to study the limits in the framework composition of BEA-type crystallites synthesized from clear basic solutions. Furthermore, the effect of the Si/Al ratio on the precursor species, ultimate crystal size, morphology and yield was investigated. The results revealed that the crystallization kinetics of nanosized Beta are dependent on the amount of Al in the precursor solutions, that is, the nucleation and growth processes are faster in Al-rich systems. The crystallization process of zeolite Beta with Si/Al ratios in the initial solutions of 14, 23 and 32 was accomplished within 72 h, whereas longer crystallization times, 140 and 264 h, were necessary to obtain crystalline products with Si/Al ratios of 42 and infinity, respectively. The intermediates and final products were investigated by complementary techniques such as XRD, HRTEM, DLS, IR, NMR spectroscopy and chemical analysis. Low temperature (77 K) CO adsorption infrared spectroscopy was used to study the Brønsted acidity of zeolite Beta samples with different Si/Al ratios. The properties of Beta nanocrystals important for the design of catalysts and selective separation materials are provided based on the results obtained from the detailed characterization.     

Optimization of Chemical Vapor Deposition Parameters for Fabrication of Oxidation-Resistant Mullite Coatings on Silicon Nitride

Fabrication of mullite (3Al₂O₃·2SiO₂) coatings by chemical vapor deposition (CVD) using AlCl₃–SiCl₄–H₂–CO₂ gas mixtures was studied. The resultant CVD mullite coating microstructures were sensitive to gas-phase composition and deposition temperature. Chemical thermodynamic calculations performed on the AlCl₃–SiCl₄–H₂–CO₂ system were used to predict an equilibrium CVD phase diagram. Results from the thermodynamic analysis, process optimization, and effects of various process parameters on coating morphology are discussed. Dense, adherent crystalline CVD mullite coatings ∼2 μm thick were successfully grown on Si₃N₄ substrates at 1000°C and 10.7 kPa total pressure. The resultant coatings were 001 textured and contained well-faceted grains ∼0.3–0.5 μm in size.     

Detection of CO<Subscript>2</Subscript> and O<Subscript>2</Subscript> by iron loaded LTL zeolite films

Detection of oxygen and carbon dioxide is important in the field of chemical and biosensors for atmosphere and biosystem monitoring and fermentation processes. The present study reports on the preparation of zeolite films doped with iron nanoparticles for detection of CO₂ and O₂ in gas phase. Pure nanosized LTL type zeolite with monomodal particle size distribution loaded with iron (Fe-LTL) was prepared under hydrothermal condition from colloidal precursor suspensions. The zeolite was loaded with iron to different levels by ion exchange. The Fe-LTL suspensions were used for preparation of thin films on silicon wafers via spin coating method. The reduction of the iron in the zeolite films was carried out under H₂ flow (50% H₂ in Ar) at 300 °C. The presence of iron nanoparticles is proved by in situ ultra-violet-visible spectroscopy. The properties of the films including surface roughness, thickness, porosity, and mechanical stability were studied. In addition, the loading and distribution of iron in the zeolite films were investigated. The Fe-LTL zeolite films were used to detect O₂ and CO₂ in a concentration dependent mode, followed by IR spectroscopy. The changes in the IR bands at 855 and 642 cm^–1 (Fe?O?H and Fe?O bending vibrations) and at 2363 and 2333 cm^–1 (CO₂ asymmetric stretching) corresponding to the presence of O₂ and CO₂, respectively, were evaluated. The response to O₂ and CO₂ was instant, which was attributed to great accessibility of the iron in the nanosized zeolite crystals. The saturation of the Fe-LTL films with CO₂ and O₂ at each concentration was reached within less than a minute. The Fe-LTL films detected both oxygen and carbon dioxide in contrast, to the pure LTL zeolite film.

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