Enhanced Electrocatalytic Oxygen Reduction Reaction of TiO Nanotubes by Combining Surface Oxygen Vacancy Engineering and Zr Doping.

This work examines the cooperative effect between Zr doping and oxygen vacancy engineering in anodized TiO nanotubes (TNTs) for enhanced oxygen reduction reactions (ORRs). Zr dopant and annealing conditions significantly affected the electrocatalytic characteristics of grown TNTs. Zr doping results in Zr substituted for Ti species, which indirectly creates oxygen vacancy donors that enhance charge transfer kinetics and reduce carrier recombination in TNT bulk.

Enhanced electrocatalytic oxygen redox reactions of iron oxide nanorod films by combining oxygen vacancy formation and cobalt doping.

A synergistic effect of Co-doping and vacuum-annealing on electrochemical redox reactions of iron oxide films is demonstrated in the present work. In this research, a series of defect-rich iron oxy/hydroxide nanorod arrays: α-FeOOH, FeO, and FeO nanorod thin film catalysts were synthesized a hydrothermal approach followed by thermal and vacuum treatments. Besides, a cobalt doping process was employed to prepare the thin film of Co-doped FeO nanorods.

Scalable Synthesis of Oxygen Vacancy-Rich Unsupported Iron Oxide for Efficient Thermocatalytic Conversion of Methane to Hydrogen and Carbon Nanomaterials.

Thermocatalytic methane decomposition (TCMD) involving metal oxides is a more environmentally friendly and cost-effective strategy for scalable hydrogen fuel production compared to traditional methane steam reforming (MSR), as it requires less energy and produces fewer CO/CO emissions. However, the unsupported metal oxide catalysts (such as α-FeO) that would be suited for this purpose exhibit poor performance in TCMD. To overcome this issue, a novel strategy was developed as a part of this work, whereby oxygen vacancies (OVs) were introduced into unsupported α-FeO nanoparticles (NPs).

Graphite-Based Geothermometry on Almahata Sitta Ureilitic Meteorites.

The thermal history of carbon phases, including graphite and diamond, in the ureilite meteorites has implications for the formation, igneous evolution, and impact disruption of their parent body early in the history of the Solar System. Geothermometry data were obtained by micro-Raman spectroscopy on graphite in Almahata Sitta (AhS) ureilites AhS 72, AhS 209b and AhS A135A from the University of Khartoum collection. In these samples, graphite shows G-band peak centers between 1578 and 1585 cm and the full width at half maximum values correspond to a crystallization temperature of 1266 °C for graphite for AhS 209b, 1242 °C for AhS 72, and 1332 °C for AhS A135A.

Chromium Isotopic Evidence for Mixing of NC and CC Reservoirs in Polymict Ureilites: Implications for Dynamical Models of the Early Solar System.

Nucleosynthetic isotope anomalies show that the first few million years of solar system history were characterized by two distinct cosmochemical reservoirs, CC (carbonaceous chondrites and related differentiated meteorites) and NC (the terrestrial planets and all other groups of chondrites and differentiated meteorites), widely interpreted to correspond to the outer and inner solar system, respectively. At some point, however, bulk CC and NC materials became mixed, and several dynamical models offer explanations for how and when this occurred. We use xenoliths of CC materials in polymict ureilite (NC) breccias to test the applicability of such models.

Impact shock origin of diamonds in ureilite meteorites.

The origin of diamonds in ureilite meteorites is a timely topic in planetary geology as recent studies have proposed their formation at static pressures >20 GPa in a large planetary body, like diamonds formed deep within Earth's mantle. We investigated fragments of three diamond-bearing ureilites (two from the Almahata Sitta polymict ureilite and one from the NWA 7983 main group ureilite). In NWA 7983 we found an intimate association of large monocrystalline diamonds (up to at least 100 µm), nanodiamonds, nanographite, and nanometric grains of metallic iron, cohenite, troilite, and likely schreibersite.

Meteoritic Evidence for a Ceres-sized Water-rich Carbonaceous Chondrite Parent Asteroid.

Carbonaceous chondrite meteorites record the earliest stages of Solar System geo-logical activities and provide insight into their parent bodies' histories. Some carbonaceous chondrites are volumetrically dominated by hydrated minerals, providing evidence for low temperature and pressure aqueous alteration. Others are dominated by anhydrous minerals and textures that indicate high temperature metamorphism in the absence of aqueous fluids.

The First Samples from Almahata Sitta Showing Contacts Between Ureilitic and Chondritic Lithologies: Implications for the Structure and Composition of Asteroid 2008 TC.

Almahata Sitta (AhS), an anomalous polymict ureilite, is the first meteorite observed to originate from a spectrally classified asteroid (2008 TC). However, correlating properties of the meteorite with those of the asteroid is not straightforward because the AhS stones are diverse types. Of those studied prior to this work, 70-80% are ureilites (achondrites) and 20-30% are various types of chondrites.

Vasopressin Continuous Infusion Improves Intracranial Pressure and Patient Outcomes after Surgical Clipping or Endovascular Coiling of Cerebral Aneurysm.

Background: Hypertensive therapy prevents vasospasm-related delayed ischemic neurologic deficit and infarcts. New alternatives would include vasopressin which has vasoconstrictive effects and positive influence on cerebral perfusion pressure (CPP) and intracranial pressure (ICP).

Aims: The aim of this study is to demonstrate the value of vasopressin intravenous infusion (IVI) in decreasing ICP and preventing vasospasm following surgical clipping or endovascular coiling.

TiO Nanotubes for Solar Water Splitting: Vacuum Annealing and Zr Doping Enhance Water Oxidation Kinetics.

Herein, we report the cooperative effect of Zr doping and vacuum annealing on the carrier dynamics and interfacial kinetics of anodized TiO nanotubes for light-driven water oxidation. After evaluation of different Zr loads and different annealing conditions, it was found that both Zr doping and vacuum annealing lead to a significantly enhanced light harvesting efficiency and photoelectrochemical performance. The substitution of Zr by Ti species leads to a higher density of surface defects such as oxygen vacancies, facilitating electron trapping on Zr, which reduced the charge recombination and hence boosted the charge transfer kinetics.

Zinc Tantalum Oxynitride (ZnTaO₂N) Photoanode Modified with Cobalt Phosphate Layers for the Photoelectrochemical Oxidation of Alkali Water.

Photoanodes fabricated by the electrophoretic deposition of a thermally prepared zinc tantalum oxynitride (ZnTaO₂N) catalyst onto indium tin oxide (ITO) substrates show photoactivation for the oxygen evolution reaction (OER) in alkaline solutions. The photoactivity of the OER is further boosted by the photodeposition of cobalt phosphate (CoPi) layers onto the surface of the ZnTaO₂N photoanodes. Structural, morphological, and photoelectrochemical (PEC) properties of the modified ZnTaO₂N photoanodes are studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet visible (UV-Vis) diffuse reflectance spectroscopy, and electrochemical techniques.

Cooperative Catalytic Effect of ZrO and α-Fe O Nanoparticles on BiVO Photoanodes for Enhanced Photoelectrochemical Water Splitting.

Photoelectrochemical water splitting with metal oxide semiconductors offers a cost-competitive alternative for the generation of solar fuels. Most of the materials studied so far suffer from poor charge-transfer kinetics at the semiconductor/liquid interface, making compulsory the use of catalytic layers to overcome the large overpotentials required for the water oxidation reaction. Herein, we report a very soft electrolytic synthesis deposition method, which allows remarkably enhanced water oxidation kinetics of BiVO photoanodes by the sequential addition of Zr and Fe precursors.

Morphological and physiological changes in esterase and lipid peroxidation of two bean cultivars pre-soaked with potassium nitrate under salt stress.

Two broad bean cultivars (Vicia faba CV Nobaria3 and Vicia faba CV Sakha3) were obtained from Mallwi Agriculture Research Center, El Minia Governorate, Egypt. The seeds were divided into two groups, the first group soaked with distilled water, while the second group were soaked with 3 mM KNO₃, respectively, for 4 hours. Seeds were sown and left to grow for 3 weeks then treated with different concentrations of NaCl (0.

The impact and recovery of asteroid 2008 TC(3).

In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995 nm wavelength range, and designated 2008 TC(3) (refs 4-6). It subsequently hit the Earth.