The impact of the dissolved quantity of aluminum on the calculation of surface charge from titration experiments of hydrated gamma-alumina was investigated. Two methods were developed to correct this effect: direct determination of aluminum in solution in batch titration experiments and application of a dissolution rate model in continuous titration experiments. There is a large effect of dissolution on surface charge determination for pH>10 and pH < 4.5. Application of these correction methods to these pH ranges lead to apparent saturation surface charges of 1.3 and 2.3 at nm(-2), respectively. The last value seems to be the real proton-active site density, while the hydroxyl-active site density cannot be reached for easily achievable basic pH values.
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http://dx.doi.org/10.1016/s0021-9797(03)00653-2 | DOI Listing |
Sci Rep
January 2025
Hangzhou Academy of Agricultural Sciences, Hangzhou, 310024, China.
Artificial fish nests are common tools in fisheries management, providing spawning grounds to enhance the size and diversity of fish populations. This study aimed to explore the effects of deployment locations on the reproductive efficiency and preferences of fish with adhesive and demersal eggs using artificial nests. Floating artificial nests were deployed in three regions (upstream, midstream, and downstream) of a reservoir in Zhejiang, China, at locations with three topographical types: steep slope (reservoir shore, slopes > 60°), gentle slope (reservoir shore, slopes < 30°), and confluence (middle thread of channel).
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan; Isotope Science Center, The University of Tokyo, Bunkyo, Tokyo 113-0032, Japan. Electronic address:
The adsorption reaction on clay minerals is crucial for understanding the environmental behavior of various cations, including cesium (Cs). However, its details remain unclear because of multiple adsorption sites of the clay minerals, a significant difference between concentrations in the atomic-scale experiments and the actual environment, and difficulties of evaluating bonding states of the adsorbed cations. It is expected that systematic experiments at the atomic-scale with a wide concentration range and application of density functional theory (DFT) calculations overcome the problems and bring crucial insights to link laboratory experiment results with environmental sample analysis.
View Article and Find Full Text PDFJ Bone Miner Res
January 2025
MRC Lifecourse Epidemiology Centre, Human Development and Health, University of Southampton, Southampton, United Kingdom.
HIV-related mortality has fallen due to scale-up of antiretroviral therapy (ART), so more women living with HIV (WLH) now live to reach menopause. Menopausal estrogen loss causes bone loss, as do HIV and certain ART regimens. However, quantitative bone data from WLH are few in Africa.
View Article and Find Full Text PDFJ Bone Miner Res
January 2025
San Francisco Coordinating Center, California Pacific Medical Center Research Institute and University of California, San Francisco, CA 94158, United States.
Bone mineral density (BMD) levels achieved on osteoporosis treatment are predictive of subsequent fracture risk, and T-score > -2.5 has been proposed as a minimum treatment target for women with osteoporosis. Knowing the likelihood of attaining target T-scores with different medications for different baseline BMD levels can help determine appropriate initial treatment for individual patients.
View Article and Find Full Text PDFPlants (Basel)
January 2025
College of Ecology and Environment, Xinjiang University, Urumqi 830046, China.
The characteristics of heartwood and sapwood not only reflect tree growth and site quality but also provide insights into habitat changes. This study examines the natural Oliv. forest in the Arghan section of the lower Tarim River, comparing the heartwood and sapwood characteristics of at different distances from the river, as well as at varying trunk heights and diameters at breast height (DBH).
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