Bacterial inactivation is seen to be related to the nanotubes anodization potential and the silver-ions decoration.
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•TiO2 nanotubes decorated by silver nanoparticles were prepared.•Ag ...nanoparticles decoration was carried out using the photo-reduction process.•SEM and TEM imaging were used to see the microstructure of the nanotubes.•The effect of the NTs geometry on the bacterial inactivation was investigated.
This study investigates the effect of the diameter of TiO2 nanotubes and silver decorated nanotubes on optical properties and photocatalytic inactivation of Escherichia coli under visible light. The TiO2 nanotubes (TiO2-NTs) were prepared using the electrochemical method varying the anodization potential starting from 20 V until 70 V. The Ag nanoparticles were carried out using the photoreduction process under the same experimental conditions. The diameter size was determined using the scanning electronic microscopy (SEM). TiO2-NTs diameter reached ∼100 nm at 70 V. Transmission electronic microscopy (TEM) imaging confirmed the TiO2-NTs surface decoration by silver nanoparticles. The Ag-NPs average size was found to be equal to 8 nm. The X-Ray diffraction (XRD) analysis confirm that all TiO2-NTs crystallize in the anatase phases regardless the used anodization potential. The decrease of the photoluminescence (PL) intensity of Ag NPs decorated TiO2-NTs indicates the decrease of the specific area when the nanotubes diameter increases. The UV–vis absorbance show that the absorption edges was bleu shifted with the increasing of nanotubes diameter, which can be explained by the increase of the crystallites average size. The bacterial adhesion and inactivation tests were carried in the dark and under light. Bacteria were seen to adhere on TiO2-NTs in the dark; however, under light the bacteria were killed before they establish a strong contact with the TiO2-NTs and Ag/TiO2-NTs surfaces. Bacterial inactivation kinetics were faster when the anodizing potential of the NTs-preparation increases. A total bacterial inactivation was obtained on ∼100 nm nanotubes diameter within 90 min. This result was attributed to the enhancement of the TNTs crystallinity leading to reduced surface defects. Redox catalysis was seen to occur under light on the TiO2-NTs and Ag/TiO2-NTs. the photo-induced antibacterial activity on the AgO/Ag2O decorated TiO2-NTs was attributed to the interfacial charge transfer mechanism (IFCT).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
This article reports world averages of measurements of
b
-hadron,
c
-hadron, and
τ
-lepton properties obtained by the Heavy Flavor Averaging Group using results available through summer 2016. For the ...averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters,
C
P
violation parameters, parameters of semileptonic decays, and Cabbibo–Kobayashi–Maskawa matrix elements.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We propose an alternative to the classical post-treatment of the homogenization method for shape optimization. Rather than penalize the material density once the optimal composite shape is obtained ...(by the homogenization method) in order to produce a workable shape close to the optimal one, we macroscopically project the microstructure of the former through an appropriate procedure that roughly consists in laying the material along the directions of lamination of the composite. We have tested our approach in the framework of compliance minimization in two-dimensional elasticity. Numerical results are provided.
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CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A self-organized TiO
2
nanotubes were fabricated via anodization on Titanium substrate and loaded with dispersed platinum nanoparticles using electrodeposition method. The effect of electrodeposited ...Pt NPs (100 s, 200 s, 300 s, 600 s) on TiO
2
nanotubes on their photocatalytic activities for amido black (AB) dye degradation was studied. Morphological characterizations showed a highly ordered nanotubular TiO
2
structure with 15 μm of length and 100 nm of diameter using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) technics. Optical characterizations such as photoluminescence and diffuse reflectance spectroscopy proved the charges exchange between metal NPs and the semiconductor. The successful depositions of Pt on to the surface of TiO
2
-NTs contributed for the improved photocatalytic activity compared to the pure sample, due to the greater the work function of platinum nanoparticle, which further anchored the separation of photogenerated electron–hole pairs. It was found that the sample Pt/TiO
2
-NTs with 200 s of Pt deposition time offered the highest photocatalytic performance, this sample resulted 97% degradation after 90 min under UV irradiation. Due to the plasmonic effect of Pt nanoparticles we obtained an intensification in the photocatalytic activity. Kinetic studies demonstrated that the apparent first-order kinetics for the corresponding photocatalytic reaction shows that Pt/TiO
2
NTs is one of the best photocatalyst for dye degradation. Furthermore, quenching studies were performed and shows that hydroxyl radicals (OH°) and superoxide free radicals (O
2
°) were the primary and secondary reactive species during photo-degradation.
Graphical Abstract
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Haitham Jahrami,1,2 Khaled Trabelsi,3,4 Michael V Vitiello,5 Ahmed S BaHammam6,7 1Department of Psychiatry, Ministry of Health, Manama, Kingdom of Bahrain; 2Department of Psychiatry, College of ...Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain; 3High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax, 3000, Tunisia; 4Research Laboratory: Education, Motricity, Sport and Health, EM2S, LR19JS01, University of Sfax, Sfax, 3000, Tunisia; 5Department of Psychiatry & Behavioral Sciences, University of Washington, Seattle, WA, USA; 6Department of Medicine, College of Medicine, University Sleep Disorders Center, King Saud University, Riyadh, Saudi Arabia; 7The Strategic Technologies Program of the National Plan for Sciences and Technology and Innovation in the Kingdom of Saudi Arabia, Riyadh, Saudi Arabia Correspondence: Haitham Jahrami, Department of Psychiatry, College of Medicine and Medical Sciences, Arabian Gulf University, P.O. Box 26671, Manama, Kingdom of Bahrain, Tel +973 17286334, Fax +973 17270637, Email email protected
A method is proposed to measure the photon polarisation parameter
in
transitions using an amplitude analysis of
decays. Simplified models of the
system are used to simulate
and
decays, validate the ...amplitude analysis method, and demonstrate the feasibility of a measurement of the
parameter irrespective of the model parameters. Similar sensitivities to
are obtained with both the charged and neutral hadronic systems. In the absence of any background and distortion due to experimental effects, the statistical uncertainty expected from an analysis of
decays in an LHCb data set corresponding to an integrated luminosity of 9
is estimated to be 0.009. A similar measurement using
decays in a Belle II data sample corresponding to an integrated luminosity of 5
would lead to a statistical uncertainty of 0.018.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Homogeneous decoration of TiO2 nanotubes (NTs) by Ag metallic nanoparticles (NPs) was carried out by a relatively simple photoreduction process. This Ag-NPs decoration was found to improve the ...photoconversion efficiency of the TiO2-NTs based photoanodes. The x-ray photoelectron spectroscopy and x-ray diffraction analyses confirmed that all the Ag-NPs are metallic and the underlying TiO2-NTs crystallize in the anatase phase after their annealing at 400 °C, respectively. Transmission electron microscopy observations have confirmed the effective decoration of the TiO2-NTs' surface by Ag-NPs, and allowed to measure the average Ag-NPs size, which was found to increase linearly from (4 2) nm to (16 4) nm when the photoreduction time is increased from 5 to 20 min. The diffuse reflectivity of the Ag-NPs decorated TiO2-NTs was found to decrease significantly as compared to the undecorated TiO2-NTs. Interestingly, the Ag-NPs decorated TiO2-NTs exhibited a significantly enhanced photochemical response, under visible radiation, with regards to the undecorated NTs. This enhancement was found to reach its maximum for the TiO2-NTs decorated with Ag-NPs having the optimal average diameter of ∼8.5 nm. The maximum photoconversion efficiency of Ag-NPs decorated TiO2-NTs was about two times greater than for the undecorated ones. This improved photo-electro-chemical response is believed to be associated with the additional absorption of visible light of Ag-NPs through the localized surface plasmon resonance phenomenon. This interpretation is supported by the fact that the photoluminescence intensity of the Ag-NPs decorated TiO2-NTs was found to decrease significantly as compared to undecorated NTs, due to charge carriers trapping in the Ag NPs. This demonstrates that Ag-NPs decoration promotes photogenerated charges separation in the TiO2-NTs, increasing thereby their capacity for current photogeneration. The surface decoration of TiO2 NTs by noble metals NPs is expected to impact positively the use of TiO2-NTs based photoanodes in some energetic applications such as hydrogen generation and photo-electrochemical solar cells.
Titanium dioxide nanotube arrays (TiO
2
NTAs) have been synthesized using the electrochemical anodization procedure. Lead sulfide nanoparticles (PbS NPs) were deposited on TiO
2
NTAs (PbS NPs/TiO
2
...NTAs) using the pulsed laser deposition (PLD) method. The prepared samples (PbS NPs/TiO
2
NTAs) were characterized using scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), UV–Vis spectroscopy and photoluminescence. The size of the PbS NPs was controlled by varying the number of laser pulses (
N
LP
) during the PLD process. TEM observations show that the PbS NPs are in the range of 10–20 nm, consistent with the results obtained from XRD. HRTEM and diffuse reflectivity show that, at
N
LP
≥ 2500, the growth of the PbS NPs occurs on a previously formed PbS layer. Transmission and absorption spectra show that the PbS-NPs have an indirect optical bandgap which is particle size independent. This optical bandgap corresponds to excitonic transitions, which are greatly affected by oxygen defects, off-stoichiometry and other surface state defects, particularly for smaller NPs (
N
LP
< 2500). The absorption spectra of the TiO
2
NTAs show that the PbS NPs extend the absorption range of the TiO
2
-NTAs from the ultraviolet to the visible region, indicating that the PbS NPs/TiO
2
NTAs heterojunction facilitates the separation of the photogenerated charge carriers. Photoelectrochemical analyses show that a maximum photocurrent current density of ~1.05 mA/cm
2
and a photoelectrochemical conversion efficiency of 2.5% are reached for
N
LP
= 2500 under an illumination of 100 mW/cm
2
in the UV–Vis range.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The objectives of this study were to evaluate the duration and the quality of sleep, as well as daytime sleepiness, among different levels of Arab athletes (i.e., amateur, elite) and to compare sleep ...quality and duration and daytime sleepiness in athletes and sedentary individuals.
A total of 409 participants, characterized as elite athletes (n=78), amateur athletes (n=231), and sedentary individuals (n=100), participated in this study. Participants were asked to complete the Pittsburgh Sleep Quality Index (PSQI) questionnaire, for the evaluation of sleep quality, and the Epworth Sleepiness Scale (ESS), for the assessment of daytime sleepiness.
The total PSQI score was significantly higher in sedentary (total PSQI score=5.74±2.5) vs. amateur (total PSQI score=5±2.3) (P<0.001) and elite athletes (total PSQI score=4.73±2.3) (P<0.01), respectively. However, there was no significant difference between elite and amateur athletes (P>0.05). There was no significant difference (P>0.05) between levels of daytime sleepiness reported in amateur athletes (ESS score=9.6±4.3), elite athletes (ESS score=10±3.8), and sedentary individuals (ESS score=10.4±2.4).
Athletes experienced a better sleep quality compared to sedentary individuals. However, some athletes can suffer from poor sleep quality, suggesting an urgent need for the implementation of sleep hygiene education. Levels of daytime sleepiness, comparable in athletes and sedentary individuals, indicate higher normal daytime sleepiness. Thus, daily naps could be useful to prevent excessive daytime sleepiness, but future studies on this topic, efficacy, and practicality are needed.
Les objectifs de cette étude étaient d’évaluer la durée et la qualité du sommeil, ainsi que la somnolence diurne, chez différents niveaux d’athlètes arabes (amateur vs. élite) et de comparer la qualité et la durée du sommeil et la somnolence diurne chez des athlètes et des sujets sédentaires.
Un total de 409 participants, divisés en un groupe d’athlètes élites (n=78), un groupe d’athlètes amateurs (n=231) et des participants sédentaires (n=100), ont participé à cette étude. Les participants ont été invités à remplir le questionnaire Pittsburgh Sleep Quality Index (PSQI), pour l’évaluation de la qualité du sommeil, et l’Epworth Sleepiness Scale (ESS), pour l’évaluation de la somnolence diurne.
Le score PSQI total était significativement plus élevé chez les sujets sédentaires (score PSQI total=5,74±2,5) par rapport aux athlètes amateurs (score PSQI total=5±2,3) (p<0,001) et les athlètes élites (score PSQI total=4,73±2,3) (p<0,01), respectivement. Cependant, il n’y avait pas de différences significatives entre les athlètes élites et amateurs (p>0,05). Aucune différence significative (p>0,05) entre les niveaux de somnolence diurne rapportés chez les athlètes amateurs (score ESS=9,6±4,3), les athlètes élites (score ESS=10±3,8) et les sujets sédentaires (score ESS=10,4±2,4) n’a été rapportée.
La qualité du sommeil des athlètes est meilleure par rapport à celle des sujets sédentaires. Cependant, certains sportifs peuvent souffrir d’une mauvaise qualité du sommeil, ce qui suggère un besoin urgent de mettre en œuvre une éducation à l’hygiène du sommeil. Les niveaux de somnolence diurne, comparables chez les athlètes et les sujets sédentaires, indiquent une somnolence diurne noramale élevée. Ainsi, les siestes quotidiennes pourraient être utiles pour éviter une somnolence diurne excessive. Cependant, des études futures sur l’efficacité de cette stratégie sont nécessaires.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We report on the effect of Pt incorporation on the microstructural, optoelectronic and catalytic properties of TiO
2
thin films deposited by means of the pulsed-laser deposition (PLD) method. The ...structural, morphological, optoelectronic and catalytic properties of the deposited TiO
2
:Pt films were systematically investigated, as a function of their Pt content, by means of various techniques including X-ray diffraction, X-ray photoelectron spectroscopy (XPS), atomic force microscopy, Fourier-transform infra-red spectroscopy and ellipsometry. The in situ doping of the PLD-TiO
2
films, at different Pt contents, was achieved by the concomitant laser ablation of a TiO
2
target uniformly covered with Pt wires. We show that by increasing the number of Pt wires positioned on the TiO
2
target from 1 to 4, the Pt concentration of the TiO
2
:Pt films increases from 0.05 to 0.35 at.%. While the bandgap of room-temperature (RT) deposited films was found to be insensitive to their Pt content (remaining around the 3.2 eV anatase value), the TiO
2
:Pt films deposited at high temperature (T
d
= 500 °C) were found to exhibit a significant narrowing of their bandgap (from 3.3 to 2.45 eV), when their Pt content is increased (from 3.3 to 2.45 eV). From a structural point of view, while the RT-deposited TiO
2
:Pt films deposited are mainly amorphous with the presence of some TiO
2
nanocrystallites whose density increases as Pt content increases, while those deposited at 500 °C were found to crystallize in the anatase phase with their crystallinity improving with increasing Pt contents. XPS analyses have revealed that the incorporated Pt mainly exists in a metallic state, likely as nano-inclusions in an otherwise TiO
2
matrix. By being able to monitor the optoelectronic properties of the annealed TiO
2
:Pt films through their Pt content, their photocatalytic activity was significantly improved with respect to that of their undoped TiO
2
counterpart. The enhancement of the photocatalytic activity is believed to be due to an enhanced photoabsorption of photons because of bandgap narrowing along with a better harvesting of the separated photogenerated charges.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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