Article
Engineering, Civil
Brytne K. Okuhata, Donald M. Thomas, Henrietta Dulai, Brian N. Popp, Jonghyun Lee, Aly El-Kadi
Summary: The geologically complex western aquifers of Hawai'i Island serve as the primary reservoir of fresh potable water for residents, yet the area's hydrogeologic characteristics are still not well understood. This study implemented a multi-tracer approach to estimate the apparent ages of groundwater in the West Hawai'i aquifers. The results showed the presence of both young and old groundwater, with important implications for groundwater management.
JOURNAL OF HYDROLOGY
(2022)
Article
Environmental Sciences
Haidi Chen, F. Alexander Haumann, Lynne D. Talley, Kenneth S. Johnson, Jorge L. Sarmiento
Summary: The deep ocean releases large amounts of pre-industrial carbon dioxide to the atmosphere through upwelling in the Southern Ocean, which affects global climate and the ability of the Southern Ocean to absorb anthropogenic CO2. The release of CO2 is mainly concentrated in a band of upwelling waters between the Subantarctic Front and the wintertime sea-ice edge. The carbon chemistry in the subsurface waters is influenced by organic carbon remineralization and dissolution profiles, which have implications for the response of Southern Ocean CO2 fluxes to future changes in upwelling.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Jie Ni, Shan-Shan Liu, Xiao-Ping Lang, Zhen He, Gui-Peng Yang
Summary: This three-year study comprehensively characterized the concentrations of SF6 in the atmosphere and surface seawater, and found that polluted air masses from eastern Asian countries were the reason for the increase in SF6 concentrations in the study region. The ocean, as a significant sink of atmospheric SF6, has the potential to reduce its global abundance and environmental impacts.
ENVIRONMENTAL POLLUTION
(2023)
Article
Oceanography
Weimin Wang, Minggang Cai, Peng Huang, Hongwei Ke, Mian Liu, Lihua Liu, Hengxiang Deng, Bojun Luo, Chunhui Wang, Xuehong Zheng, Wenquan Li
Summary: The study utilized CFC-12 and SF6 data to estimate the mean age of water in the northern South China Sea and explored oceanographic processes related to time. Significant differences in mean water ages were observed at different density levels on both sides of the Luzon Strait, showing distinct flow patterns and transit times. The research highlighted a strong correlation between temperature and apparent oxygen utilization rates, suggesting that climate change and ocean warming could have significant impacts on oxygen consumption in the ocean, warranting further investigation.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Geochemistry & Geophysics
Rodrigo Perez-Moreno, Martin Reich, Linda Daniele, Diego Morata, Sebastian Held, Jackie Kleinsasser
Summary: This study combined stable isotopes, anthropogenic tracers, and geochemical data to investigate the origin, residence times, and evolution of thermal waters in the Lonquimay-Tolhuaca Volcanic Complex in the southern Chilean Andes. The discharge temperature of thermal waters correlates directly with the age distribution of the water samples, indicating different residence times due to distinct subsurface circulation pathways.
APPLIED GEOCHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Tobias Eder, Florenz Buss, Lukas F. B. Wilm, Michael Seidl, Maren Podewitz, Fabian Dielmann
Summary: This paper reports a new oxidative fluorination reagent consisting of an SF5- anion and a chemically inert phosphonium cation, which is thermally stable. Using this reagent, the SeF5- and TeF5- anions were successfully generated and tetrafluoro(phenyl)-lambda(5)-selenate and -tellurate were synthesized. Furthermore, further derivatization of the tetrafluoro(phenyl)-lambda(5)-tellurate allowed the introduction of functional groups into organic molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Editorial Material
Multidisciplinary Sciences
Brandy M. Toner
Summary: A revised conceptual model of iron forms in the ocean resolves discrepancies between observed and simulated levels of dissolved iron in seawater, potentially contributing to climate predictions.
Editorial Material
Multidisciplinary Sciences
Jerome Nriagu
Summary: The 1963 discovery of lead contamination in the vast oceans from car exhausts led to debate and policy changes, greatly benefiting public health and revolutionizing marine biogeochemistry practices.
Article
Chemistry, Physical
Shovan Das, Ayan Datta
Summary: The packing of molecular crystals is primarily controlled by weak London dispersion forces, which bring the molecular units into proximity to stabilize the system. This paper demonstrates that the same effect can be induced by external pressure. The minimal pressure required to accurately describe the crystal structure without LD interactions serves as a quantifiable measure for the weak intermolecular interactions. LD forces are shown to be essential for an accurate description of pressure-induced phase transitions across various types of molecules.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Maria Luz Alonso, Rosa Maria Alonso, Jose Ignacio Lombrana, Jesus Izcara, Josu Izagirre
Summary: This research explores binary and ternary gas mixtures as alternatives to SF6 in medium-voltage electrical equipment. Decomposition products in the gas mixtures were identified and quantified, along with an evaluation of their toxicity and global warming potential to determine the most suitable replacement for SF6.
Article
Multidisciplinary Sciences
Gonzalo V. Gomez-Saez, Thorsten Dittmar, Moritz Holtappels, Anika M. Pohlabeln, Anna Lichtschlag, Bernhard Schnetger, Antje Boetius, Jutta Niggemann
Summary: Dissolved organic carbon in today's oceans is an important component of the global carbon cycle, with anoxic marine environments possibly contributing to its preservation through reactions with sulfur species. Studies show that in the sulfidic waters of the Black Sea, dissolved organic sulfur is largely formed within the water column, indicating potential long-lasting effects on global climate.
Article
Engineering, Chemical
Songi Song, Ki Chul Kim
Summary: This study investigates the structural stability and thermodynamic degradation probabilities of selected fluorocarbon compounds as alternative insulating gases. It reveals that these compounds are suitable insulation candidates under vacuum conditions, but the presence of specific impurity gases may compromise their stability.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Shiqing Huang, Yedong Wang, Chubin Hu, Xiaoyu Yan
Summary: The computational study demonstrated that the nucleophilic activation of sulfur hexafluoride by N-heterocyclic olefins is both thermodynamically and kinetically favorable under mild conditions. The activation process leads to the formation of sulfur pentafluoride anion, and the energy barrier is linearly related to the HOMO energy of substrates. This finding suggests that compounds with higher energy in HOMO can be more efficient in activating SF6.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Ecology
Amita Singh, Suneet Dwivedi, Alok Kumar Mishra
Summary: A regional coupled ocean-biogeochemical modeling experiment was conducted over the Indian Ocean region to generate high-resolution gridded data of Chlorofluorocarbons (CFC11 and CFC12) from 1999 to 2017. The results showed realistic simulation of hydrography, with higher CFC concentrations in the western Arabian Sea and decreasing concentrations from north to south in the Bay of Bengal. Seasonal variations were observed, with the highest surface concentrations in winter and monsoon seasons. The study also found that ENSO had a significant influence on CFC concentrations in both regions.
REGIONAL STUDIES IN MARINE SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
Samuel C. Mogen, Nicole S. Lovenduski, Allysa R. Dallmann, Luke Gregor, Adrienne J. Sutton, Steven J. Bograd, Nathali Cordero Quiros, Emanuele Di Lorenzo, Elliott L. Hazen, Michael G. Jacox, Mercedes Pozo Buil, Stephen Yeager
Summary: This study characterizes the biogeochemical properties of the Eastern North Pacific upper ocean during the Winter of 2013-2014 using observations and models, and finds that the Blob is associated with increased aragonite saturation and decreased oxygen concentration.
GEOPHYSICAL RESEARCH LETTERS
(2022)