Solid-state metathesis reactions under pressure: A rapid route to crystalline gallium nitride

High pressure chemistry has traditionally involved applying pressure and increasing temperature until conditions become thermodynamically favorable for phase transitions or reactions to occur. Here, high pressure alone is used as a starting point for carrying out rapid, self-propagating metathesis reactions. By initiating chemical reactions under pressure, crystalline phases, such as gallium nitride, can be synthesized which are inaccessible when initiated from ambient conditions. The single-phase gallium nitride made by metathesis reactions under pressure displays significant photoluminescence intensity in the blue/ultraviolet region. The absence of size or surface-state effects in the photoluminescence spectra show that the crystallites are of micron dimensions. The narrow lines of the x-ray diffraction patterns and scanning electron microscopy confirm this conclusion. Brightly luminescent thin films can be readily grown using pulsed laser deposition

PSSA doped polyaniline nanofiber based ZnO/64° YX LiNbO3 SAW H2 gas sensor

A polyaniline (PANI) nanofiber based surface acoustic wave (SAW) gas sensor, has been developed and investigated towards hydrogen (H<sub>2</sub>) gas. A template-free, rapidly-mixed reaction approach was employed to synthesize polyaniline nanofibers, which utilized chemical oxidative polymerization of aniline. Hydrochloric acid (HCl) was used as the dopant acid in the synthesis of the polyaniline nanofibers. Polystyrene sulfonic acid (PSSA) was used to re-dope PANI nanofibers after dialyzing with ammonium hydroxide. Then PSSA doped nanofibers were deposited onto a ZnO/64 YX LiNbO<sub>3</sub> SAW transducer. The sensor was exposed to various concentrations of H<sub>2</sub> gas in an ambient of synthetic air, and operated at room temperature

A layered surface acoustic wave gas sensor based on a polyaniline/In2O3 nanofibre composite

A polyaniline/In2O3 nanofibre composite based layered surface acoustic wave ( SAW) sensor has been developed and investigated for different gases. Chemical oxidative polymerization of aniline in the presence of finely divided In2O3 was employed to synthesize a polyaniline nanofibre/In2O3 nanoparticle composite. The nanocomposite was deposited onto a layered ZnO/64 degrees YX LiNbO3 SAW transducer. The novel sensor was exposed to H-2, NO2 and CO gases. Fast response and recovery times with good repeatability were observed at room temperature

Nanomaterial based room temperature Hydrogen gas sensors

Polyaniline (PANI) nanofiber and PANI/semi-conducting metal oxide nanofiber composites based layered surface acoustic wave (SAW) and conductometric sensors have been developed and investigated towards hydrogen (H<sub>2</sub>) gas. Chemical oxidative polymerization of aniline was employed to synthesize pure PANI nanofibers as well as PANI/semi-conducting metal oxide composites. The nano-materials were deposited onto layered ZnO/64deg YX LiNbO<sub>3</sub> SAW and conductometric transducers. The novel sensors were exposed to H<sub>2</sub> gas. Fast response and recovery with good repeatability were observed at room temperature

Use of aids for smoking cessation and alcohol reduction: A population survey of adults in England.

BACKGROUND: It is important for policy planning to chart the methods smokers and high-risk drinkers use to help them change their behaviour. This study assessed prevalence of use, and characteristics of users, of support for smoking cessation and alcohol reduction in England. METHODS: Data were used from the Smoking and Alcohol Toolkit Studies, which involve monthly face-to-face computer-assisted interviews of adults aged 16+ in England. We included data collected between June 2014 and July 2015 on 1600 smokers who had made at least one quit attempt and 911 high-risk drinkers (defined as scores >8+ on the full AUDIT or 5+ on questions 1-3 of the AUDIT-C) who had made an attempt to cut down in the past 12 months. Participants provided information on their socio-demographic characteristics and use of aids during their most recent quit attempt including pharmacotherapy, face-to-face counselling, telephone support, self-help materials (digital and printed), and complementary medicine. RESULTS: A total of 60.3% of smokers used aids in the past year, compared with just 14.9% of high-risk drinkers. Use of pharmacotherapy was high among smokers and very low among drinkers (56.0%versus1.2%). Use of other aids was low for both behaviours: face-to-face counselling (2.6%versus4.8%), self-help materials (1.4%versus4.1%) and complementary medicine (1.0%versus0.5%). Use of aids was more common among smokers aged 25-54 compared with 16-24 year olds (25-34,ORadj1.49,p = 0.012; 35-44,ORadj1.93,p 10 relative to 20,ORadj4.23,p = 0.001), and less common among ethnic minorities (ORadj0.69,p = 0.026). For alcohol reduction, use of aids was higher among ethnic minority groups (ORadj2.41;p = 0.015), and those of social-grade D/E relative to AB (ORadj2.29,p = 0.012&ORadj3.13,p < 0.001). CONCLUSION: In England, the use of pharmacotherapy is prevalent for smoking cessation but not alcohol reduction. Other aids are used at a low rate, with face-to-face counselling being more common for alcohol reduction than smoking cessation

Graphene-like nano-sheets/36° LiTaO3 surface acoustic wave hydrogen gas sensor

Presented is the material and gas sensing properties of graphene-like nano-sheets deposited on 36deg YX lithium tantalate (LiTaO3) surface acoustic wave (SAW) transducers. The graphene-like nano-sheets were characterized via scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The graphenelike nano-sheet/SAW sensors were exposed to different concentrations of hydrogen (H2) gas in a synthetic air at room temperature. The developed sensors exhibit good sensitivity towards low concentrations of H2 in ambient conditions, as well as excellent dynamic performance towards H2 at room temperature

A room temperature polyaniline nanofibre hydrogen gas sensor

Electro-conductive polyaniline (PANI) nanofiber based surface acoustic wave (SAW) gas sensors have been investigated with hydrogen (H 2) gas. A template-free, rapidly mixed method was employed to synthesize polyaniline nanofibers using chemical oxidative polymerization of aniline. The nanofibers were deposited onto a layered ZnO/64° YX LiNbO3 SAW transducer for gas sensing applications. The novel sensor was exposed to various concentrations of H2 gas at room temperature. The sensor response, defined as the relative variation in operating frequency of oscillation due to the introduction of the gas, was 3.04 kHz towards a 1% H2 concentration. A relatively fast response time of 8 sec and a recovery time of 60 sec with good repeatability were observed at room temperature. Due to room temperature operation, the novel gas sensor is promising for environmental and industrial applications

Probing Spin-Charge Relation by Magnetoconductance in One-Dimensional Polymer Nanofibers

Polymer nanofibers are one-dimensional organic hydrocarbon systems containing conducting polymers where the non-linear local excitations such as solitons, polarons and bipolarons formed by the electron-phonon interaction were predicted. Magnetoconductance (MC) can simultaneously probe both the spin and charge of these mobile species and identify the effects of electron-electron interactions on these nonlinear excitations. Here we report our observations of a qualitatively different MC in polyacetylene (PA) and in polyaniline (PANI) and polythiophene (PT) nanofibers. In PA the MC is essentially zero, but it is present in PANI and PT. The universal scaling behavior and the zero (finite) MC in PA (PANI and PT) nanofibers provide evidence of Coulomb interactions between spinless charged solitons (interacting polarons which carry both spin and charge)

Predictors of and reasons for attempts to reduce alcohol intake: A population survey of adults in England

OBJECTIVE: This study aimed to assess the predictors among high-risk drinkers in England of attempts to reduce alcohol consumption, the reasons given for these attempts and the association between the various reasons and alcohol consumption. METHODS: Data came from 2,800 high-risk drinkers taking part in the Alcohol Toolkit Study (ATS) between March 2014 and November 2016 who were attempting to reduce their alcohol consumption. Participants completed the Alcohol Use Disorders Identification Test (AUDIT) and were asked questions regarding their socio-demographic characteristics, attempts to cut down and reasons for doing so. RESULTS: Those cutting down were significantly older (OR 1.01, p<0.001), were more likely to be female (OR 1.32, p<0.05), had higher AUDIT-C scores (OR 1.12, p<0. 001), were less likely to be of white ethnicity (OR 0.64, p<0. 001), and were more likely to reside in the South of England (OR 1.34, p<0. 001). They were also more likely to be of higher occupationally-based social-grades (p<0. 001). The main reported reasons for reducing consumption were: fitness (22.5%), weight loss (20.4%), future health (20.4%), advice from a health-care professional (7.9%) and cost (7.6%). Those reporting the followings reasons for cutting down had higher AUDIT-C scores than those who did not report these reasons: a concern about further health problems (β 0.20, p<0.05), advice from a doctor/health worker (β 0.38, p<0.05), that drinking was too expensive (β 0.42, p<0.01) and detoxification (β 0.42, p<0.01). Lower AUDIT-C scores were noted among those who reported that they knew someone who was cutting down (β -0.67, p<0.05), that there was no reason (β -0.36, p<0.05), or they didn’t know why they were cutting down (β -0.25, p<0.05). CONCLUSIONS: Around a fifth of high-risk drinkers in England report trying to reduce their drinking, particularly older, high-socioeconomic female drinkers from the south of England. Attempts to cut down appear to be driven by a desire to improve health, advice from others and cutting down on the cost of drinking