Spherical Rod Research Articles

In English

The aim of presented work was to synthesize geopolymers based on the metakaolin and to determine their adsorption capability in the process of cesium and strontium ions removal from the aqueous solutions. New approaches were proposed for obtaining the two samples of geopolymers in techologically suitable forms. Morphology of materials was investigated by means of X-ray fluorescence analysis (XRF), low-temperature nitrogen adsorption/desorption and scanning electron microscopic studies (SEM). As it follow from the data of XRF analysis, SiO2 and Al2O3 oxides found to be the major components in all samples investigated (~ 54–84 wt. %). As was determined by SEM studies, geopolymers consisted from nanosized particles, amorphous geopolymers binder and unreacted kaolin. It has been found that all samples involve the mesopores with approx. 1–40 nm radii. The greatest specific surface area calculated by the Brunauer-Emmet-Teller (BET) method had the sample obtained in the forms of spherical rods (SBET = 88 m2/g) that about 10 times greater than for initial kaolin taken for synthesis. The ion exchange capacities of materials in the process of Cu2+, Cs+ and Sr2+ removal from water solution were determined and it was found that these properties depends on the method of materials obtaining. Data showed that the geopolymers were more effective for removal the desired ions than initial kaolin. The greatest adsorption capacity towards cesium ions was received on the samples obtained in forms of pyramids and was reached 1.75 mmol/g. Experimental data were fitted into the Langmuir models and the main Langmuir constants were calculated. When analysing the data of investigation with comparing the literature data it was noted that geopolymers obtained can be used in adsorption technology for purification of water from radionuclides as technologically suitable sorbents.

Analysis of the Impact of Circular Contour Error Based on CNC Machine

To improve the processing accuracy of the CNC machine, the errors caused by uneven pitch spacing between the servo feeding axes of the NC machine are analyzed. With the combination of the principle of plane circular contour motion track synthesis, the influence of the pitch errors produced by the X and Y axes on the circular contour errors is analyzed. Finally, the experimental platform is adopted to analyze the data before and after screw pitch error compensation with a spherical rod. The results verify that the screw pitch errors impact the outline errors, and the proportion of mismatch errors was reduced by 96.88% after screw pitch errors compensation.

Green synthesis of zinc oxide nanoparticles from camellia sinensis: Organic dye degradation and antibacterial activity

In this paper, we report to green synthesis of zinc oxide nanoparticles (ZnO NPs) from the plant extract (Camellia sinensis) by using the hot plat combustion method (HPCM). The XRD analysis validates that ZnO NPs have a hexagonal wurtzite structure, without the formation of any other impurity and secondary phases. FE-SEM images show the synthesis of zinc oxide includes spherical rods of ZnO NPs with the least size range of 10–20 nm and elements present in the biologically green synthesized ZnO NPs confirmed by EDAX mapping. Synthesized ZnO NPs photocatalytic activity was evaluated by degrading methyl orange (MO) dye and degradation of 80 % using 0.5 g ZnO NPs for 180 min irradiation time. Further, the antibacterial property of ZnO NPs was evaluated against two different strains of bacteria like Staphylococcus aureus and Escherichia coli; however, the antibacterial efficiency of ZnO NPs effective against E. coli compared to S. aureus.

Postharvest disease inhibition in fruit by synthesis and characterization of chitosan iron oxide nanoparticles

Abstract Economic and ecofriendly surface modification of nanoparticles is a consistent challenge for agricultural purposes. Application of surface modified greatly reduces the risks of postharvest diseases and weight loss during storage. For this purpose, chitosan coated iron oxide nanoparticles (CH–Fe2O3 NPs) found to be useful due to the presence of basal metallic core and organic functional groups on the surface. The present study is based on one step synthesis of CH–Fe2O3 NPs to control emerging diseases and weight loss on postharvest peach fruit. Moreover, we characterized these synthesized NPs through Ultraviolet visible (UV–Vis) spectroscopy, X-ray diffraction pattern (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Characterization results showed synthesized NPs with 218 absorption band, rhombohedral crystalline nature, presence of various organic functional groups, spherical rod shape structure ranging from 20 to 30 nm. We isolated and identified a new fungal species (Rhizopus stolonifer), which causes the postharvest soft rot disease in peach fruit leading to fruit damage and weight loss. We found that 1% CH–Fe2O3 NPs showed significant difference as compared to 0.50% synthetic fungicide by effectively inhibiting microbial growth on fruit surface and reduced weight loss. We concluded that surface engineered NPs can be promising fungicide to control emerging diseases and controlling food loss.

Deposition of Au/TiO2 Nanocomposite on ITO Surface by Seed-Mediated Liquid Phase Deposition Method

An efficient, simple and new procedure has been performed to synthesis Au/TiO2 nanocomposite thin film on solid surface of ITO by seed-mediated of liquid phase deposition (LPD) method. The deposition of Au seed was applied by our previously reported seed-mediated growth procedure. The solution was prepared by mixing HAuCl4 and (NH4)2TiF6 successfully deposited on to ITO substrate containing Au seed. After one hour well adhered film was obtained by mentioned approach of synthesis and nonocomposite with spherical rod like networks has been successfully grown. The resulting nanocomposites were confirmed by ultraviolet-visible (Uv-Vis) absorption spectroscopy. Further characterization and morphology was checked by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD).

A Consideration of an Optical Coupler for Optical Submarine Transmission Laser Redundancy Systems

Theoretical and experimental results are described for a new optical coupler which consists of two laser diodes, two GRIN spherical rod lenses, a polarizing filter, and a single-mode fiber, and which employs laser diode polarization characteristics for an optical submarine transmission laser redundancy system. This optical coupler has two channels at 1.3 μm wavelength. Optical coupler loss values, which include coupling loss, polarization loss, and assembly loss, are 4.9 dB for one laser diode and 5.2 dB for another laser diode. Such loss values are almost the same as the conventional laser diode module loss for a single-mode fiber. This paper describes in detail a laser redundancy system in an optical submarine transmission system, structure and characteristics of an optical coupler, and experimental results on a high bit rate long-haul transmission system using the proposed optical coupler.

Optical coupler for laser redundancy system

Experimental results are described for a new optical coupler, which consists of two laser diodes, two GRIN spherical rod lenses, a polarised filter and a single-mode fibre, and employs laser diode polarisation characteristics for an optical submarine transmission laser redundancy system. This optical coupler has two channels at a 1.3 μm wavelength. Optical coupler loss, which includes coupling loss, polarisation loss and assembly loss, is 4.9 dB for laser diode 1, and 5.2 dB for laser diode 2.