Coherent Spin Preparation of Indium Donor Qubits in Single ZnO Nanowires.

Shallow donors in ZnO are promising candidates for photon-mediated quantum technologies. Utilizing the indium donor, we show that favorable donor-bound exciton optical and electron spin properties are retained in isolated ZnO nanowires. The inhomogeneous optical line width of single nanowires (60 GHz) is within a factor of 2 of bulk single-crystalline ZnO. Spin initialization via optical pumping is demonstrated and coherent population trapping is observed. The two-photon absorption width approaches the theoretical limit expected due to the hyperfine interaction between the indium nuclear spin and the donor-bound electron.

Interface engineering of heterogeneous NiMn layered double hydroxide/vertically aligned NiCo2S4 nanosheet as highly efficient hybrid electrocatalyst for overall seawater splitting.

We report the fabrication of a heterogeneous catalyst through vertically aligned NiCo2S4/Ni3S2 nanosheet with encapsulation of ultrathin NiMn layered double hydroxide over self-standing nickel foam (NM/NCS/NS/NF) via two-step hydrothermal processes. Benefiting from more adequate catalytic active centres and copious interfacial charge transfer channels, NM/NCS/NS/NF electrode demonstrates superior bifunctional activity for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) processes under alkaline fresh/simulated seawater electrolyte conditions. As a result, NM/NCS/NS/NF electrode requires the smallest overpotentials of 282 & 312 mV (OER) and 171 & 204 mV (HER) to attain current densities of 30 & 50 mA cm-2 respectively under alkaline simulated seawater electrolyte conditions. Besides, the presence of amorphous NiMn LDH layers over crystalline NiCo2S4/Ni3S2 catalyst stimulates surface adsorption of oxygen intermediate species, water dissociate ability on catalytic active centres, and mass transport with electron transfer at the interface. Further, the two-electrode configuration assisted electrolyser system delivers an efficient overall water splitting activity with minimum cell voltages of 1.54 V (in 1 M KOH) and 1.56 V (in 1 M KOH+0.5 M NaCl) at a current density of 10 mA cm-2. Besides, a fabricated electrolyser cell provides a more sustained water electrolysis process and robust durability for 20 h which displays NM/NCS/NS/NF electrode is a vibrant and potential candidate for realistic seawater electrolysis. Therefore, our proposed heterogeneous electrocatalyst could open up a new platform for developing efficient large-scale efficient seawater electrolysis.

Microstructural study of assorted ZnO nanostructures: nanocombs, nanocones and microspheres.

We report the microstructural study of ZnO nanostructures: nanocombs, nanocones and microspheres, synthesized using a simple thermal evaporation technique. While nanocombs require the presence of a catalyst, nanocones and hollow ZnO microspheres have been synthesized on silicon substrate in absence of any catalyst or template material. ZnO hexagonal nanocones have been synthesized on Si(100) substrates by directly evaporating zinc acetate dihydrate, at a low temperature of 400 degrees C, without using any carrier gas. The possible mechanism of formation of these structures has been discussed in brief. Chemical composition analysis by energy dispersive X-ray spectroscopy shows an O rich condition of ZnO nanocones and oxygen deficient condition of nanocombs.

Synthesis of novel ZnO hexagonal nanocones by direct thermal evaporation method.

Novel ZnO hexagonal nanocones have been synthesized on Si(100) substrate by directly evaporating zinc acetate dihydrate, at a low temperature of 400 degrees C, without using any carrier gas and catalyst. Clear formation of hexagonal nanocones was confirmed by high resolution scanning electron microscopy. Size of the hexagonal nanocones was found to be 600 nm. Structural analysis by X-ray diffraction pattern revealed that most of the nanocones were aligned along the c-axis (002). Chemical composition analysis by energy dispersive X-ray spectroscopy shows both zinc and oxygen are nearly equal in stoichiometry. Vapor-liquid-solid (VLS) mechanism was used to explain the growth of ZnO hexagonal nanocones. Diffused reflectance spectroscopy confirms the band gap of ZnO hexagonal nanocones as 3.34 eV. Photoluminescence of the ZnO hexagonal nanocones shows a near band-edge emission at 398 nm. No observable green-yellow emission, which corresponds to oxygen vacancies, was observed.

Knowledge, value, opinion and practice about usage of pit and fissure sealant among dental professionals in Chennai, Tamil Nadu, India.

AIM: A study was aimed to assess the knowledge, value, opinion, and practice regarding the use of dental sealants among private dental practitioners in Chennai, Tamil Nadu, India. MATERIALS AND METHODS: A self-administrated questionnaire were distributed to 192 private dental practitioners in Chennai, Tamil Nadu, India by using simple random sampling. A convenience sampling technique was employed. The questionnaire consisted of 28 items, which included information about knowledge, value, opinion, and practice regarding dental sealants. The questionnaire was obtained from the study by San Martin et al. 2013 and Kailash Asawa et al. 2014. Frequency distribution was tabulated. For frequency distribution strongly, strongly agree, and agree were combined as "agree" and strongly disagree and disagree were combined as "disagree." There were no changes in "neutral." RESULTS: Among the 196 study subjects 56.2% were males and 43.8% were females with their clinical experience of 52.1% for <5 years, 35.4% for 5-10 years, and 13.5% for >15 years. The mean scores for knowledge, value, opinion, and practice were 41.8 ± 3.7, 18.7 ± 2.8, 18.1 ± 1.4, and 12.9 ± 2.3, respectively. CONCLUSION: The results suggest that dental practitioners had satisfactory knowledge about pit and fissure sealant and had neutral attitudes about sealants being effective. Dental practitioners adequately used the pit and fissure sealants but they did not follow the standardized procedures and specific guidelines.

Evaluation of Dentifrice Containing Nano-hydroxyapatite for Dentinal Hypersensitivity: A Randomized Controlled Trial.

BACKGROUND: This randomized, double-blind, parallel arm study was carried out to evaluate and compare the effectiveness between nano-hydroxyapatite (HAP) and a benchmark dentifrice in reducing dentin hypersensitivity. MATERIALS AND METHODS: About 36 patients were selected, randomly divided into two groups and was evaluated clinically using three different stimuli, i.e., tactile, air blast, and cold water test. The patient's responses to various stimuli were recorded using a visual analog scale at baseline and after 4 weeks. RESULTS: Statistical analysis was done using unpaired and paired t-tests. It was seen that patients treated in both groups showed significant reductions scores across all sensitivity measures at the end of 4 weeks. CONCLUSION: The HAP containing toothpaste was effective in reducing dentin hypersensitivity with pre-existing benchmark toothpaste tested and hence can be advocated in the management of hypersensitivity.

A codoping route to realize low resistive and stable p-type conduction in (Li, Ni):ZnO thin films grown by pulsed laser deposition.

We report on the growth of Li-Ni codoped p-type ZnO thin films using pulsed laser deposition. Two mole percent Li monodoped ZnO film shows highly insulating behavior. However, a spectacular decrease in electrical resistivity, from 3.6 × 10(3) to 0.15 Ω cm, is observed by incorporating 2 mol % of Ni in the Li-doped ZnO film. Moreover, the activation energy drops to 6 meV from 78 meV with Ni incorporation in Li:ZnO lattice. The codoped [ZnO:(Li, Ni)] thin film shows p-type conduction with room temperature hole concentration of 3.2 × 10(17) cm(-3). Photo-Hall measurements show that the Li-Ni codoped p-ZnO film is highly stable even with UV illumination. XPS measurements reveal that most favorable chemical state of Ni is Ni(3+) in (Li, Ni): ZnO. We argue that these Ni(3+) ions act as reactive donors and increase the Li solubility limit. Codoping of Li, with other transitional metal ions (Mn, Co, etc.) in place of Ni could be the key to realize hole-dominated conductivity in ZnO to envisage ZnO-based homoepitaxial devices.