Simultaneous Emerging Contaminant Removal and H2O2 Generation Through Electron Transfer Carrier Effect of Bi─O─Ce Bond Bridge Without External Energy Consumption.

Conventional advanced oxidation processes (AOPs) require significant external energy consumption to eliminate emerging contaminants (ECs) with stable structures. Herein, a catalyst consisting of nanocube BiCeO particles (BCO-NCs) prepared by an impregnation-hydrothermal process is reported for the first time, which is used for removing ECs without light/electricity or any other external energy input in water and simultaneous in situ generation of H2O2. A series of characterizations and experiments reveal that dual reaction centers (DRC) which are similar to the valence band/conducting band structure are formed on the surface of BCO-NCs. Under natural conditions without any external energy consumption, the BCO-NCs self-purification system can remove more than 80% of ECs within 30 min, and complete removal of ECs within 30 min in the presence of abundant electron acceptors, the corresponding second-order kinetic constant is increased to 3.62 times. It is found that O2 can capture electrons from ECs through the Bi─O─Ce bond bridge during the reaction process, leading to the in situ production of H2O2. This work will be a key advance in reducing energy consumption for deep wastewater treatment and generating important chemical raw materials.

Revealing The Morphology of Ink and Aerosol Jet Printed Palladium-Silver Alloys Fabricated from Metal Organic Decomposition Inks.

Palladium films hold signicance due to their remarkable affinity for hydrogen diffusion, rendering them valauble for the seperation and purification of hydrogen in membrane reactors. However, palladium is expensive, and its films can become brittle after only a few cycles of hydrogen separation. Alloying with silver has been shown to overcome the problem of palladium embrittlement. Palladium-silver films have been produced via several methods but all have drawbacks, such as difficulties controlling the alloy composition. This study explores two promising jet printing methods: Inkjet and Aerosoljet. Both methods offer potential advantages such as direct patterning, which reduces waste, enables thin film production, and allows for the control of alloy composition. For the first time, palladium-silver alloys have been produced via inkjet printing using a palladium-silver metal organic decomposition (MOD) ink, which alloys at a temperature of 300 °C with nitrogen. Similarly, this study also demonstrates a pioneering approach for Aerosol Jet printing, showing the potential of a novel room-temperature method, for the deposition of palladium-silver MOD inks. This low temperature approach is considered an important development as palladium-silver MOD inks are originally designed for deposition on heated substrates.

Vanishing racial disparities in drowning in Florida.

OBJECTIVES: To examine the change in the racial disparity in drowning in Florida from 1970 to 2015 and to analyse the contextual factors associated with white, black and Hispanic drowning rates in Florida from 2007 to 2015. METHODS: Our outcome variable is county-level annual drowning rates by race, ethnicity, sex and age group. We computed county-level contextual data, including emergency weather events, temperature, extreme weather, number of pools, quality of pools, coastline, swimming participation rates and prominent black competitive swim teams. RESULTS: Between 1970 and 1990, the disparity in drowning rates between white and black males in Florida decreased dramatically. By 2005, the overall age-adjusted drowning rates converged. This convergence was most striking for those aged 10-34 and 35-64. While the gap has declined dramatically, there remains a racial disparity in drownings among those aged 10-34. CONCLUSIONS: Overall, racial disparities in drowning have disappeared in Florida. However, some disparities remain. There is a persistent disparity in drownings among those aged 10-34.

Ratiometric fluorescence nanosensors based on core-shell structured carbon/CdTe quantum dots and surface molecularly imprinted polymers for the detection of sulfadiazine.

Sulfadiazine is an environmental pollutant derived from abuse of antibiotics. Its content in environmental water is closely related to human health. Thus, a novel dual-emission surface molecularly imprinted nanosensor is designed for the specific adsorption and detection of sulfadiazine. In the system, blue emissive carbon quantum dots wrapped with silica served as the internal reference signal for eliminating background interference, while red emissive thioglycolic acid modified CdTe quantum dots (CdTe QDs), which are low dimensional semiconductor materials by the combination of cadmium and tellurium with excellent optical properties, were encapsulated in the imprinted layer to offer recognition signal. The fluorescence of CdTe quantum dots was quenched and the fluorescence quenching degree of carbon quantum dots was inconspicuous with the increase of concentration of sulfadiazine, thereby reflecting the color change. The detection of sulfadiazine was successfully achieved in a concentration range of 0.25-20 µmol/L with detection limit of 0.042 µmol/L and nanosensors had specific recognition for sulfadiazine over its analogues. Compared to single-emission fluorescence sensors, ratiometric fluorescence nanosensors had wider linear range and higher detection accuracy. Furthermore, the nanosensors were also successfully applied for the determination of sulfadiazine in real water and milk samples with acceptable recoveries. The study provides a feasible method for the detection of sulfadiazine and a reference for the detection of sulfonamides.

Competitive Swimming and Racial Disparities in Drowning.

This paper provides compelling evidence of an inverse relationship between competitive swimming rates and drowning rates using Centers for Disease Control and Prevention (CDC) data on fatal drowning rates and membership rates from USA Swimming, the governing organization of competitive swimming in the United States. Tobit and Poisson regression models are estimated using panel data by state from 1999-2007 separately for males, females, African Americans and whites. The strong inverse relationship between competitive swimming rates and unintentional deaths through fatal drowning is most pronounced among African Americans males.