Two newly synthesized ligands based on 1,3,4-thiadiazolethiosemicarbazone have been isolated by the condensation reaction of 2,3-disubstituted-5-acetyl-1,3,4-thiadiazole derivatives with thiosemicarbazide in acidic medium in addition to their Co(II) chelates. The synthesized cobalt chelates that have been obtained by the reaction of each ligand with cobalt acetate were confrmed to have the formulae [(LM)Co(OAc)(H2O)2]H2O (LM–Co) and [(LN)Co(OAc)(H2O)2]0.5CH3OH (LN– Co); where LM and LN are 1,3,4-thiadiazolethiosemicarbazone ligands with methyl and nitro substituents, respectively. Comparison of the IR spectrum of each ligand with that of its cobalt complex implied that both ligands acted as monobasic tridentate connecting to the cobalt ion through N atoms of both azomethine group and thiadiazole ring and S atom of deprotonated SH group as well. The two complexes have been proved to have octahedral geometrical structures. The synthesized compounds were studied as corrosion inhibitors for carbon steel in molar hydrochloric acid solution using several chemical and electrochemical techniques. The investigational outcomes displayed that the inhibition efciencies of the examined compounds were found to augment as the concentrations of such compounds raised. At comparable inhibitors concentration, the inhibition efciency was a little increased following the order: LM>LM–Co>LN>LN–Co. The acquired high inhibition efciencies of the explored compounds were ascribed to the potent adsorption of the molecules on the steel surface and construction of adherent layers. Such adsorption was found to accord with Langmuir adsorption isotherm. There is a good correlation in the results obtained from the diferent measurements used

The inhibition efficiencies of ampicillin and flucloxacillin expired drugs on mild steel (MS) corrosion in 1.0 M sulfuric acid medium was examined at 20oC using weight loss (WL), and electrochemical potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Examined expired drugs are set to be efficient inhibitors for MS corrosion in sulfuric acid medium. The experimental outcomes of weight loss technique displayed that the inhibition performances of the investigated expired drugs augmented with increasing concentrations of such drugs and reduced by raising the temperature. The observed high inhibition efficiencies of the studied expired drugs may be owing to powerful adsorption of the drug species on MS surface resulting in formation of protective layers. Adsorption of the tested expired drugs on the MS surface was set to accord with Langmuir adsorption isotherm. The assessed thermodynamic parameters supported the mechanism of physical adsorption of the inhibitors.

Acyclovir (ACV) and Omeprazole (OMP) are two expired drugs examined as an inhibitors for the dissolution of Sabic iron in 1.0 M HCl using weight loss, electrochemical impedance and two types of polarization; galvanostatic and potentiodynamic measurements . Increase the concentration of expired ACV and OMP increases the efficacy of inhibition that also decreases with temperature. These drugs acts as mixed inhibitors that was detected by galvanostatic polarization studies. The inhibition activity of ACV and OMP owing to its horizontal adsorption of them on the Sabic iron surface because of the presence of several active centers. The adsorption follows Langmuir isotherm. The impedance data demonstrated one capacitive loop suggesting that the charge transfer control the corrosion reaction. The expired ACV and OMP performed as an efficient pitting corrosion inhibitor by moving the pitting potential to more noble values.

Photo-induced charge transfer and photo-excited hot spots at nanoscale of graphene on single Ag nanoparticles (NPs) are inferred from the evolution of the Raman G-peak of graphene with the exciting laser power. Raman spectra of graphene attached to single Ag NPs on Si reflecting semiconductor and on quartz transparent dielectric substrates were investigated. It is demonstrated that optically-driven enhanced electron-phonon and phonon-phonon coupling define two regimes of the G-peak dependence with increasing the laser power. Optically controlled charge transfer at the nanoscale regime in graphene on single Ag NPs can meet the demands for future optoelectronic devices that require controllable doping with improved sensitivities, e.g. “light-gated” transistors. In addition, light tuning of the electron-phonon/phonon-phonon coupling opens up new ways for solar cell and energy harvesting technology.

Optical gain and loss of microcavity greatly affect the quality of lasing, how to improve optical gain and decrease optical loss is of great significance for the preparation of laser. In this study, four types standard microdisks with different thicknesses of 2.2 μm, 1.9 μm, 1.7 μm, and 1.45 μm were fabricated by micromachining technology process to modulate optical gain and loss of microdisk lasing. The whispering gallery mode lasing in the ultraviolet range of GaN microdisk devices was investigated for these devices in order to clarify the effect of microdisk thickness on device characteristics. The quality factor Q and lasing mode number for different thicknesses are calculated from the stimulated spectra. The lifetimes of the exciton combination properties of the devices were observed using time-resolved PL spectroscopy. The lasing modes are modulated, and the lifetime decreases, while the Q factor of the devices first

We investigate the plasmon resonance in the light interaction with a graphene nanoshell which consists of graphene wrapped around a low− loss dielectric core. In this work, Polystyrene (PS) and Titanium dioxide (TiO 2) cores are proposed. This study is restricted to small nanoparticles with diameters significantly smaller than the wavelength of incident light. Therefore, we adopt the quasi− static approach that provides in− depth insights into the plasmon resonance of core− shell nanoparticles. The proposed graphene nanoshell can support two localized surface plasmon resonances (LSPRs). These plasmon resonance modes correspond to the symmetric and antisymmetric dipole-like modes described in the hybridization theory. The observed resonance modes are characterized by a narrow bandwidth and a broadband resonance tunability in the visible to near-infrared (NIF) range. The impacts of the optical …

Abstract: Recently, three-dimensional nickel foam (3D-Nf) has been increasingly studied; however,
further modifications in nanoscale surface modification are necessary for particular applications.
In this work, three-dimensional hierarchically porous nanogranular NiS (NiS-3D-Nf) and wrinkleshaped
NiS (w-NiS-3D-Nf) structures were fabricated directly on nickel foam by a simple one-step
solvothermal process using two different solvents. Several characterization techniques, including
X-ray diffraction pattern, X-ray photoelectron spectroscopy, and scanning electron microscopy, were
used to characterize the samples’ properties. To prove their applicability, supercapacitor electrodes
were tested directly in a three-electrode assembly cell. The resulting w-NiS-3D-Nf electrodes exhibited
greater capacitive activity than the NiS-3D-Nf electrodes. The optimized w-NiS-3D-Nf electrodes
delivered an excellent specific capacitance of 770 Fg?1, at a current density of 1 Ag?1, compared
with the NiS-3D-Nf electrodes (162.0 Fg?1 @ 1 Ag?1), with a cyclic stability of over 92.67% capacitance
retention after 2200 cycles. The resultant unique structure with integrated hierarchical
three-dimensional configuration can not only enhance abundant accessible surface areas but also
produce strong adhesion to the 3D-Nf, facilitating the fast transportation of ions and electrons for
the electrochemical reaction via the conductive 3D-Nf. This set of results suggests that the modification
of 3D-Nf surfaces with a suitable solvent has highly significant effects on morphology, and
ultimately, electrochemical performance. Additionally, the current preparation approach is simple
and worthwhile, and thus offers great potential for supercapacitor applications.

Abstract: This article outlines the preparation of manganese-doped copper nanoparticles (Mn + Cu
NPs) using Vinca rosea (L.) leaf extract as a convenient and environmentally friendly substance.
UV–vis, FT–IR, XRD, SEM–EDAX, and DLS instrumental techniques were employed to describe
the physical and chemical properties of synthesized V. rosea extract-mediated Vr-Mn + Cu NPs.
The synthesized Vr-Mn + Cu NPs were observed to be monodispersed and spherical, with an average
size of 412 nm. The plant extract includes a variety of phytochemical components. The Vr-Mn + Cu
NPs also have potential antioxidant and antibacterial properties against selected pathogens. The green
synthesized Vr-Mn + Cu NPs showed a maximum inhibition zone of 16.33  0.57 mm against E. coli.
For dye degradation, MR, EBT, and MO showed the highest degradation percentage capabilities
with Vr-Mn + Cu NP-based adsorbents, which were determined to be 78.54  0.16, 87.67  0.06,
and 69.79  0.36. The results clearly show that biosynthesized Vr-Mn + Cu NPs may be employed as
an antioxidant, antibacterial, photocatalytic dye degradation, and catalytic agent, as well as being
ecologically benign.

Abstract: In the current work, we studied the effect of Ga+3 substitutions on the Ta+5 sites in
Li5+2xLa3Ta2-xGaxO12 (LLT-Ga) lithium conducting garnets (with x = 0.1–0.5) in order to enhance the
ionic conductivity of these materials. The current materials are prepared by solid state reaction and
their electrical properties are studied by impedance spectroscopy measurements. XRD data showed
that cubic garnet phases are obtained for LLT-Ga garnets. The ionic conductivity increased by one
order of magnitude for x = 0.3 composition with a value of ~4  10?5 S/cm compared to that of
Li5La3Ta2O12 material. Moreover, the hopping frequency and the concentration of mobile Li+ ions
were estimated from analysis of the conductivity spectra, and it was found that both the concentration
and mobility of Li+ ions increased with increasing Ga+3 content in the materials. The dielectric and
relaxation properties were studied in the dielectric permittivity and electric modulus formalisms.
The current materials exhibited giant values of the dielectric constant of "0 ~ 6500, originating from
internal effects in the materials.

Abstract: In the current study, we report on the dielectric behavior of colossal-dielectric-constant
Na1/2La1/2Cu3Ti4O12 (NLCTO) ceramics prepared by mechanochemical synthesis and spark plasma
sintering (SPS) at 850 C, 900 C, and 925 C for 10 min. X-ray powder diffraction analysis showed that
all the ceramics have a cubic phase. Scanning electron microscope observations revealed an increase
in the average grain size from 175 to 300 nm with an increase in the sintering temperature. SPS
NLCTO ceramics showed a room-temperature colossal dielectric constant (>103) and a comparatively
high dielectric loss (>0.1) over most of the studied frequency range (1 Hz—40 MHz). Two relaxation
peaks were observed in the spectra of the electrical modulus and attributed to the response of grain
and grain boundary. According to the Nyquist plots of complex impedance, the SPS NLCTO ceramics
have semiconductor grains surrounded by electrically resistive grain boundaries. The colossal
dielectric constant of SPS NLCTO ceramics was attributed to the internal barrier layer capacitance
(IBLC) effect. The high dielectric loss is thought to be due to the low resistivity of the grain boundary
of SPS NLCTO.