Highly responsive and selective ozone sensor based on Ga doped ZnS-ZnO composite sprayed films.

Ozone detection is currently the subject of wide scientific and technological research, motivated by its harmful impact on human safety, environment and health. With the aim of searching for new highly sensitive materials for ozone detection, Ga-doped ZnS and ZnS-ZnO films were deposited by a spray pyrolysis technique. The obtained films were annealed at 400 °C for two hours. The ozone sensing properties were investigated by measuring the sensor resistance for several ozone concentrations ranging from 30 to 120 ppb. The sensor response reveals a dependence on the gallium concentration. The best response was obtained with 4% doping gallium. The sensitivity is 4.5 ppb-1 at 260 °C and the response to 30 ppb ozone is 150. Moreover, the sensor shows high performance such as good selectivity and fast rapidity.

Annealing effect on the physical properties of TiO2 thin films deposited by spray pyrolysis.

Titanium dioxide (TiO2) thin films were deposited on glass substrates at 350 °C using the spray pyrolysis technique. As deposited and annealed thin films were characterized by X-ray diffraction, scanning electron microscopy, UV-VIS spectroscopy, and photodetection. Unlike the as deposited samples which were amorphous, annealed samples show an anatase phase. Films were absorbent in the UV region and the band gap energy decreases from 3.78 eV to 3.4 eV with annealing. The photoresponse of TiO2 photodetectors was recorded under UV (λ1 = 365 nm, λ2 = 254 nm) and visible light illumination by reversible switching (ON/OFF) cycles using DC electrical characterization. Photosensitive properties such as reproducible photosensitivity, responsivity, and detectivity were also studied.

Dielectric and electrical properties of annealed ZnS thin films. The appearance of the OLPT conduction mechanism in chalcogenides.

The annealing temperature (T a) dependence of the structural, morphological, electrical and dielectric properties of ZnS thin films was investigated. In this work, we consider the as-deposited and annealed ZnS thin films at different temperatures. The as-deposited films were amorphous in nature. However, the films annealed at T a ≥ 673 K, exhibited a hexagonal structure with (002) preferential orientation. The post annealing caused an improvement in crystallinity. The best one was observed at T a = 723 K. Grain size increased from 7 nm to 25 nm as annealing temperature was increased from 673 K to 723 K. The surface of annealed samples is homogenous and uniform and the rms roughness is dependent on the annealing temperature: it increases with temperature within the range 5-50 nm. The film electrical conductance is found to be dependent on frequency measurement and annealing temperature: the dc conductance exhibits semi-conductor behavior for all ZnS films over the explored range of temperature and the conductance was found to enhance with increasing annealing temperature up to 623 K. In addition, it was observed that the highest conductance and lowest activation energy of ZnS films were obtained at an annealing temperature of 623 K. The mechanism of alternating current ac conductance can be reasonably explained in terms of the overlapping-large polaron tunnelling (OLPT) model for samples annealed at 623 K and 673 K. To our knowledge, this conduction mechanism was rarely found in chalcogenide materials. A significant change of Nyquist plot with annealing temperature was noted permitting the correlation between the microstructure and its electrical properties. The impedance analysis investigated that the relaxation process is well pronounced for the both annealed films at 623 K and 673 K. The dielectric behavior was associated to the polarization effect, an improvement on the dielectric constant ε' and dielectric loss ε'' with annealing was noticed.

Investigation of the effect of S/In molar ratio on physical properties of sprayed In2S3 thin films.

Indium sulfide (In2S3) thin films have been synthesized on glass substrates using the spray technique (CSP). The S : In molar ratio was varied from 1 to 4 in the starting solution. The Raman analysis confirms the formation of the ß-In2S3 material and the absence of a secondary phase. The EDS analysis reveals that our layers are pure. The thin film surface is free of cracks, as observed in AFM images. Optical transmission achieved 80% in the visible and near infrared region. The refractive index (n) is affected by the changes in the S/In molar ratio. The optical parameters, single oscillator energy (E 0), dispersion energy (E d) and high frequency dielectric constant (ε ∞), are calculated via the Wemple-DiDomenico model. In addition, the photoconductivity kinetics in In2S3 films for S/In = 2 were investigated and analyzed. The I-V characteristics and the photoresponse were also studied.

Music therapy, a review of the potential therapeutic benefits for the critically ill.

Intensive care units are a stressful milieu for patients, particularly when under mechanical ventilation which they refer to as inhumane and anxiety producing. Anxiety can impose harmful effects on the course of recovery and overall well-being of the patient. Resulting adverse effects may prolong weaning and recovery time. Music listening, widely used for stress release in all areas of medicine, tends to be a reliable and efficacious treatment for those critically ill patients. It can abate the stress response, decrease anxiety during mechanical ventilation, and induce an overall relaxation response without the use of medication. This relaxation response can lower cardiac workload and oxygen consumption resulting in more effective ventilation. Music may also improve sleep quality and reduce patient's pain with a subsequent decrease in sedative exposure leading to an accelerated ventilator weaning process and a speedier recovery.

Acute Parotitis as a Complication of Noninvasive Ventilation.

Several conditions, including oropharyngeal dryness, pressure sores, ocular irritation, epistaxis, or gastric distension, have been described during noninvasive ventilation (NIV). Although this technique has been widely used in intensive care units and emergency wards, acute swelling of the parotid gland remains a scarcely reported complication. We describe herein the case of an 82-year-old man who developed unilateral parotitis during prolonged NIV for acute heart failure. Intravenous antibiotics, corticosteroids, and adjusting the mask laces' position allowed rapid resolution of clinical symptoms.