High Performance Photocatalytic Activity of Mg2+ Doped Hexagonal ZnO Nanoparticles in the Methylene Blue Degradation under UV Irradiation.

Mg2+ doped hexagonal ZnO nanoparticles with different Mg2+contents (0%, 1%, 2%, 3%,4%, 5%, 10%, 15%, 20% and 25%) were prepared from oxalate precursors synthesized by direct reaction in the solid state between oxalic acid dihydrate (H2C2O4.2H2O), nitrate salts of zinc (Zn(NO3)2.6H2O) and magnesium (Mg(NO3)2.6H2O) at 150 °C. The resulting precursors were subsequently calcined at 500 °C to produce the corresponding oxides. In addition, the oxalates of the single metals were also prepared by heating at 180 °C to dehydrate the complexes, before using TGA thermal gravimetric analysis to determine the temperature range of the decomposition. The obtained oxides were characterized using X-ray Diffraction (XRD), Brunauer–Emmett–Teller technique (BET), transmission electron microscopy (TEM) and  tested as photocatalysts in the degradation of methylene blue (MB) under UV irradiation. The results show a segregation of phases starting at an Mg2+ content of 10%. The crystallites’ sizes, calculated using Scherer formula from the XRD data, are in the nanoscale for all the samples (19.8 to 29.8 nm), in good agreement with the particle size observed in TEM (20 to 50 nm). However, larger particles sizes were obtained from BET, ranging from 70 to 123 nm, due the agglomerated state of the powder. On the other hand, the highest efficiency as a photocatalyst in the photodegradtion of MB was observed for samples 7 and 8 corresponding to 10% and 15% in Mg2+ content respectively. The reaction rates were found to be 0.57min-1 for undoped ZnO and 1.17 min-1 for samples 7 and 8. In this range, the substituted compounds are twice more efficient than the undoped ZnO

Controlling of crystal size and optical band gap of CdO nanopowder semiconductors by low and high Fe contents

The CdO:Fe nanopowder semiconductors were synthesized by the sol–gel calcination for the first time. The structural properties of Fe doped CdO samples were analyzed by AFM and XRD measurements. XRD patterns of the pure and Fe-doped CdO samples reveal that the pure and Fe doped CdO nanopowders are polycrystalline of cubic CdO structure. The crystallite size of undoped and Fe-doped CdO samples is changed unsystematically with a regular increase of Fe content. The optical band gaps of Fe doped CdO samples were determined for the first time by diffused reflectance measurements. The optical band gap of the samples is increased with the increase of Fe dopant inside the host matrix (CdO) up to 15 % followed by a decrease in its value. It is evaluated that Fe doped CdO nanopowder semiconductors can be producted by sol–gel calcination for advanced technological application

Adsorption Sites of Hydrogen Atom on Pure and Mg-Doped Multi-Walled Carbon Nanotubes

Hydrogen adsorption sites on pure multiwalled carbon nanotube (MWCNT) and Mg-doped MWCNTs material system have been investigated using molecular dynamics (MD) simulations as well as quantum chemical calculations. Through combining MWCNTs with Mg, the hydrogen adsorption sites energy on this Mg-MWCNTs system is found to be larger than that of the pure MWCNTs. Additionally, it was found that, through Mg-doping, new adsorption sites for hydrogen molecules are created in comparison with undoped nanotubes. It is also found that H atom is preferably adsorbed at every place near magnesium atom

Federation of Internet experimentation facilities: architecture and implementation

International audienceRealistic experimentation facilities are indispensable to accelerate the design of novel Future Internet systems. As many of these ground-breaking new applications and services cover multiple innovation areas, the need for these solutions to be tested on cross-domain facilities with both novel infrastructure technologies and newly emerging service platforms is rising. The Fed4FIRE project therefore aims at federatingotherwise isolated experimentation facilities in order to foster synergies between research communities. Currently the federation includes over 15 facilities from the Future Internet Research and Experiment (FIRE) initiative, covering wired, wireless and sensor networks, SDN and OpenFlow, cloud computing, smart city services,etc.This paper presents the architecture and implementation details of the federation, based on an extensive set of requirements coming from infrastructure owners, service providers and support communitie

The Saudi Critical Care Society practice guidelines on the management of COVID-19 in the ICU: Therapy section

BACKGROUND: The rapid increase in coronavirus disease 2019 (COVID-19) cases during the subsequent waves in Saudi Arabia and other countries prompted the Saudi Critical Care Society (SCCS) to put together a panel of experts to issue evidence-based recommendations for the management of COVID-19 in the intensive care unit (ICU). METHODS: The SCCS COVID-19 panel included 51 experts with expertise in critical care, respirology, infectious disease, epidemiology, emergency medicine, clinical pharmacy, nursing, respiratory therapy, methodology, and health policy. All members completed an electronic conflict of interest disclosure form. The panel addressed 9 questions that are related to the therapy of COVID-19 in the ICU. We identified relevant systematic reviews and clinical trials, then used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach as well as the evidence-to-decision framework (EtD) to assess the quality of evidence and generate recommendations. RESULTS: The SCCS COVID-19 panel issued 12 recommendations on pharmacotherapeutic interventions (immunomodulators, antiviral agents, and anticoagulants) for severe and critical COVID-19, of which 3 were strong recommendations and 9 were weak recommendations. CONCLUSION: The SCCS COVID-19 panel used the GRADE approach to formulate recommendations on therapy for COVID-19 in the ICU. The EtD framework allows adaptation of these recommendations in different contexts. The SCCS guideline committee will update recommendations as new evidence becomes available