Skokie, the ACLU and the Endurance of Democratic Theory

ZnO nanorods (NRs) with high surface area to volume ratio and biocompatibility is used as an efficient photosensitizer carrier system and at the same time providing intrinsic white light needed to achieve cancer cell necrosis. In this letter, ZnO nanorods used for the treatment of breast cancer cell (T47D) are presented. To adjust the sample for intracellular experiments, we have grown the ZnO nanorods on the tip of borosilicate glass capillaries (0.5 mu m diameter) by aqueous chemical growth technique. The grown ZnO nanorods were conjugated using protoporphyrin dimethyl ester (PPDME), which absorbs the light emitted by the ZnO nanorods. Mechanism of cytotoxicity appears to involve the generation of singlet oxygen inside the cell. The novel findings of cell-localized toxicity indicate a potential application of PPDME-conjugated ZnO NRs in the necrosis of breast cancer cell within few minutes

With No Deliberate Speed: The Segregation of Roma Children in Europe

In this study, by taking the advantage of both inorganic ZnO nanoparticles and the organic material chitosan as a composite seed layer, we have fabricated well-aligned ZnO nanorods on a gold-coated glass substrate using the hydrothermal growth method. The ZnO nanoparticles were characterized by the Raman spectroscopic techniques, which showed the nanocrystalline phase of the ZnO nanoparticles. Different composites of ZnO nanoparticles and chitosan were prepared and used as a seed layer for the fabrication of well-aligned ZnO nanorods. Field emission scanning electron microscopy, energy dispersive X-ray, high-resolution transmission electron microscopy, X-ray diffraction, and infrared reflection absorption spectroscopic techniques were utilized for the structural characterization of the ZnO nanoparticles/chitosan seed layer-coated ZnO nanorods on a gold-coated glass substrate. This study has shown that the ZnO nanorods are well-aligned, uniform, and dense, exhibit the wurtzite hexagonal structure, and are perpendicularly oriented to the substrate. Moreover, the ZnO nanorods are only composed of Zn and O atoms. An optical study was also carried out for the ZnO nanoparticles/chitosan seed layer-coated ZnO nanorods, and the obtained results have shown that the fabricated ZnO nanorods exhibit good crystal quality. This study has provided a cheap fabrication method for the controlled morphology and good alignment of ZnO nanorods, which is of high demand for enhancing the working performance of optoelectronic devices

Second-harmonic generation of ZnO nanoparticles synthesized by laser ablation of solids in liquids

We report the synthesis of small zinc oxide nanoparticles (ZnO NPs) based colloidal suspensions and the study of second-harmonic generation from aggregated ZnO NPs deposited on glass substrates. The colloidal suspensions were obtained using the laser ablation of solids in liquids technique, ablating a Zn solid target immersed in acetone as the liquid medium, with ns-laser pulses (1064 nm) of a Nd-YAG laser. The per pulse laser fluence, the laser repetition rate frequency and the ablation time were kept constant. The absorption evolution of the obtained suspensions was optically characterized through absorption spectroscopy until stabilization. Raman spectroscopy, SEM and HRTEM were used to provide evidence of the ZnO NPs structure. HRTEM results showed that 5–8 nm spheroids ZnO NPs were obtained. Strong second-harmonic signal is obtained from random ZnO monocrystalline NPs and from aggregated ZnO NPs, suggesting that the high efficiency of the nonlinear process may not depend on the NPs size or aggregation state

Zinc oxide-nickel cermet selective coatings obtained by sequential electrodeposition

The investigation of pulse electrodepositing modes influence on crystal structure, morphology and optical properties of ZnO has revealed the conditions in which quasi-one-dimensional (1D) ZnO nanorod arrays are formed as separate nanorods. Due to a sufficiently high resistance of zinc oxide, the electrodeposition of nickel on the fluorine doped tin oxide (FTO)/ZnO surfaces carried out in space between the ZnO nanorods. An incomplete filling of the gaps between nanorods by the nickel nanoparticles through subsequent Ni electrodeposition ensured the creation of ZnO–Ni graded cermets. The cermets, in which electrochemical filling of the spaces between ZnO nanorods by Ni, was performed in the pulse mode. It provided higher absorption of visible and near IR light. It was shown that the manufactured ZnO–Ni graded cermets have high light absorption combined with comparatively low thermal losses, so these cermets are promising cheap and affordable selective coatings for solar heat collectors

The growth of ZnO crystals from the melt

The peculiar properties of zinc oxide (ZnO) make this material interesting for very different applications like light emitting diodes, lasers, and piezoelectric transducers. Most of these applications are based on epitaxial ZnO layers grown on suitable substrates, preferably bulk ZnO. Unfortunately the thermochemical properties of ZnO make the growth of single crystals difficult: the triple point 1975 deg C., 1.06 bar and the high oxygen fugacity at the melting point p_O2 = 0.35 bar lead to the prevailing opinion that ZnO crystals for technical applications can only be grown either by a hydrothermal method or from "cold crucibles" of solid ZnO. Both methods are known to have significant drawbacks. Our thermodynamic calculations and crystal growth experiments show, that in contrast to widely accepted assumptions, ZnO can be molten in metallic crucibles, if an atmosphere with "self adjusting" p_O2 is used. This new result is believed to offer new perspectives for ZnO crystal growth by established standard techniques like the Bridgman method.Comment: 6 pages, 6 figures, accepted for J. Crystal Growt