The influence of long-term exposure of Mg–Al mixed oxide at ambient conditions on its transition to hydrotalcite

AbstractBlack-colored (α, γ-phase) CsPbI3 perovskites have a small bandgap and excellent absorption properties in the visible light regime, making them attractive for solar cells. However, their long-term stability in ambient conditions is limited. Here, we demonstrate a strategy to improve structural and electrical long-term stability in γ-CsPbI3 by the use of an ultraviolet-curable polyethylene glycol dimethacrylate (PEGDMA) polymer network. Oxygen lone pair electrons from the PEGDMA are found to capture Cs+ and Pb2+ cations, improving crystal growth of γ-CsPbI3 around PEGDMA. In addition, the PEGDMA polymer network strongly contributes to maintaining the black phase of γ-CsPbI3 for more than 35 days in air, and an optimized perovskite film retained ~90% of its initial electrical properties under red, green, and blue light irradiation.

Download Full-text

Testing Long-Term Predictions from Hydro-Geochemical Models

MRS Proceedings ◽

10.1557/proc-333-805 ◽

1993 ◽

Vol 333 ◽

Author(s):

William E. Glassley ◽

Carol J. Bruton ◽

William L. Bourcier

Keyword(s):

Yucca Mountain ◽

Taupo Volcanic Zone ◽

Ambient Conditions ◽

Volcanic Zone ◽

Site Specific ◽

Thermally Induced ◽

Induced Flow ◽

Geochemical Models ◽

Kinetics And Thermodynamic

ABSTRACTThermally induced flow of liquid water and water vapor at the potential repository site at Yucca Mountain, Nevada, will extend hundreds of meters away from the repository edge. The resultant transfer of heat and mass will sufficiently perturb the ambient conditions such that a variety of mineralogical and chemical reactions will occur that may modify hydrological properties. The consequences of this “coupling” of geochemical and hydrological processes will vary through time, and will occur to different degrees in four regimes (T < Tboiling; T = Tboiling; T > T boiling; cooling) that will develop within the repository block. The dominant processes in the regimes differ, and reflect the local balance between: 1) kinetics and equilibrium; 2) dissolution and precipitation; 3) evaporation and boiling; and 4) fluid flow in matrix and fractures. Simulations were conducted of the evolution of these regimes, using laboratory derived kinetics and thermodynamic data, and site specific mineralogical and hydrological properties. These simulations identify regions where chemical and mineralogical equilibrium is likely to be achieved, and where net changes in hydrological properties will be concentrated. Tests of the results of these simulations have been initiated using field data from the Taupo Volcanic Zone, New Zealand. A preliminary series of calculations suggest that relative changes in porosity of as much as ± 20% to 30% may be possible for rocks with an initial porosity of 10%.

Download Full-text

Increased microbial expression of organic nitrogen cycling genes in long-term warmed grassland soils

ISME Communications ◽

10.1038/s43705-021-00073-5 ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Joana Séneca ◽

Andrea Söllinger ◽

Craig W. Herbold ◽

Petra Pjevac ◽

Judith Prommer ◽

...

Keyword(s):

Nitrogen Cycling ◽

Cell Walls ◽

Organic Nitrogen ◽

Soil Microbial Communities ◽

Microbial Cell ◽

Ambient Conditions ◽

Soil Microbial ◽

Soil Temperatures ◽

Microbial Turnover

AbstractGlobal warming increases soil temperatures and promotes faster growth and turnover of soil microbial communities. As microbial cell walls contain a high proportion of organic nitrogen, a higher turnover rate of microbes should also be reflected in an accelerated organic nitrogen cycling in soil. We used a metatranscriptomics and metagenomics approach to demonstrate that the relative transcription level of genes encoding enzymes involved in the extracellular depolymerization of high-molecular-weight organic nitrogen was higher in medium-term (8 years) and long-term (>50 years) warmed soils than in ambient soils. This was mainly driven by increased levels of transcripts coding for enzymes involved in the degradation of microbial cell walls and proteins. Additionally, higher transcription levels for chitin, nucleic acid, and peptidoglycan degrading enzymes were found in long-term warmed soils. We conclude that an acceleration in microbial turnover under warming is coupled to higher investments in N acquisition enzymes, particularly those involved in the breakdown and recycling of microbial residues, in comparison with ambient conditions.

Download Full-text

Communication—Partial Oxidation of MnS for Synergistic Electrocatalysis of N2-to-NH3 Fixation at Ambient Conditions

Journal of The Electrochemical Society ◽

10.1149/1945-7111/ac3ab8 ◽

2021 ◽

Author(s):

Peiei Li ◽

Dan Cheng ◽

Xiaohua Zhu ◽

Meiling Liu ◽

Youyu Zhang

Keyword(s):

Partial Oxidation ◽

Reduction Reaction ◽

Ambient Conditions ◽

Faradaic Efficiency ◽

Bosch Process ◽

Ambient Nh3 ◽

Reaction Performance ◽

Excellent Selectivity

Abstract Compared with the traditional Haber-Bosch process, electrochemical N2-to-NH3 reduction affords an eco-friendly and sustainable alternative to ambient NH3 synthesis with the aid of efficient electrocatalysts. In this work, partial oxidation of MnS to obtain the MnS-Mn3O4 is proved as a promising noble-free electrocatalysts of N2to NH3 fixation at ambient conditions. When tested in 0.1 M Na2SO4, the electrochemical N2 reduction reaction performance of MnS-Mn3O4 is improved comparing with the MnS, which achieves large NH3 yield of 16.74 μg h–1 mgcat.–1 and a high Faradaic efficiency of 5.72%. It also exhibits excellent selectivity of N2-to-NH3 and strong long-term electrochemical stabil

Download Full-text

Proteomic Analysis of Stationary Phase in the Marine Bacterium “Candidatus Pelagibacter ubique”

Applied and Environmental Microbiology ◽

10.1128/aem.00599-08 ◽

2008 ◽

Vol 74 (13) ◽

pp. 4091-4100 ◽

Cited By ~ 44

Author(s):

Sarah M. Sowell ◽

Angela D. Norbeck ◽

Mary S. Lipton ◽

Carrie D. Nicora ◽

Stephen J. Callister ◽

...

Keyword(s):

Stationary Phase ◽

Thioredoxin Reductase ◽

Capillary Liquid Chromatography ◽

Nutrient Concentrations ◽

Ambient Conditions ◽

Term Survival ◽

Protein Encoding ◽

Quantitative Examination ◽

Candidatus Pelagibacter Ubique

ABSTRACT “Candidatus Pelagibacter ubique,” an abundant marine alphaproteobacterium, subsists in nature at low ambient nutrient concentrations and may often be exposed to nutrient limitation, but its genome reveals no evidence of global regulatory mechanisms for adaptation to stationary phase. High-resolution capillary liquid chromatography coupled online to an LTQ mass spectrometer was used to build an accurate mass and time (AMT) tag library that enabled quantitative examination of proteomic differences between exponential- and stationary-phase “Ca. Pelagibacter ubique” cells cultivated in a seawater medium. The AMT tag library represented 65% of the predicted protein-encoding genes. “Ca. Pelagibacter ubique” appears to respond adaptively to stationary phase by increasing the abundance of a suite of proteins that contribute to homeostasis rather than undergoing a major remodeling of its proteome. Stationary-phase abundances increased significantly for OsmC and thioredoxin reductase, which may mitigate oxidative damage in “Ca. Pelagibacter,” as well as for molecular chaperones, enzymes involved in methionine and cysteine biosynthesis, proteins involved in ρ-dependent transcription termination, and the signal transduction enzyme CheY-FisH. We speculate that this limited response may enable “Ca. Pelagibacter ubique” to cope with ambient conditions that deprive it of nutrients for short periods and, furthermore, that the ability to resume growth overrides the need for a more comprehensive global stationary-phase response to create a capacity for long-term survival.

Download Full-text

Defect-rich fluorographene nanosheets for artificial N2 fixation under ambient conditions

Chemical Communications ◽

10.1039/c9cc01920k ◽

2019 ◽

Vol 55 (29) ◽

pp. 4266-4269 ◽

Cited By ~ 64

Author(s):

Jinxiu Zhao ◽

Jiajia Yang ◽

Lei Ji ◽

Huanbo Wang ◽

Hongyu Chen ◽

...

Keyword(s):

N2 Fixation ◽

Formation Rate ◽

Ambient Conditions ◽

Faradaic Efficiency ◽

Metal Free

Defect-rich fluorographene behaves as a metal-free catalyst for the artificial conversion of N2 to NH3 at ambient conditions. In 0.1 M Na2SO4, it achieves a faradaic efficiency (FE) of 4.2% with an NH3 formation rate (RNH3) of 9.3 μg h−1 mgcat.−1 at −0.7 V vs. RHE, with strong long-term electrochemical durability.

Download Full-text

Extended storage of SARS-CoV-2 nasopharyngeal swabs does not negatively impact results of molecular-based testing across three clinical platforms

Journal of Clinical Pathology ◽

10.1136/jclinpath-2020-206738 ◽

2020 ◽

pp. jclinpath-2020-206738

Author(s):

Karin A Skalina ◽

D Y Goldstein ◽

Jaffar Sulail ◽

Eunkyu Hahm ◽

Momka Narlieva ◽

...

Keyword(s):

Real World ◽

Nasopharyngeal Swab ◽

Molecular Testing ◽

Clinical Tests ◽

Ambient Conditions ◽

Long Term Stability ◽

The Us ◽

Us Fda ◽

World Environment

With the global outbreak of COVID-19, the demand for testing rapidly increased and quickly exceeded the testing capacities of many laboratories. Clinical tests which receive CE (Conformité Européenne) and Food and Drug Administration (FDA) authorisations cannot always be tested thoroughly in a real-world environment. Here we demonstrate the long-term stability of nasopharyngeal swab specimens for SARS-CoV-2 molecular testing across three assays recently approved by the US FDA under Emergency Use Authorization. This study demonstrates that nasopharyngeal swab specimens can be stored under refrigeration or even ambient conditions for 21 days without clinically impacting the results of the real-time reverse transcriptase-PCR testing.

Download Full-text

Facile benzene reduction promoted by a synergistically coupled Cu–Co–Ce ternary mixed oxide

Chemical Science ◽

10.1039/d0sc02238a ◽

2020 ◽

Vol 11 (22) ◽

pp. 5766-5771

Author(s):

Hao Chen ◽

Wenwen Lin ◽

Zihao Zhang ◽

Zhenzhen Yang ◽

Kecheng Jie ◽

...

Keyword(s):

Mixed Oxide ◽

Aromatic Rings ◽

Metal Composites ◽

Mild Conditions ◽

Earth Abundant ◽

Ternary Mixed Oxide

Hydrogenation of aromatic rings promoted by earth-abundant metal composites under mild conditions is an attractive and challenging subject in the long term.

Download Full-text

Material Characterization of Magnetorheological Elastomers with Corroded Carbonyl Iron Particles: Morphological Images and Field-dependent Viscoelastic Properties

International Journal of Molecular Sciences ◽

10.3390/ijms20133311 ◽

2019 ◽

Vol 20 (13) ◽

pp. 3311 ◽

Cited By ~ 1

Author(s):

Siti Aishah Binti Abdul Aziz ◽

Saiful Amri Mazlan ◽

Nur Azmah Nordin ◽

Nor Azlin Nazira Abd Rahman ◽

U Ubaidillah ◽

...

Keyword(s):

Carbonyl Iron ◽

Matrix Material ◽

Rheological Characteristics ◽

Iron Particles ◽

Ambient Conditions ◽

X Ray ◽

Field Dependent ◽

Mr Effect

High temperatures and humidity could alter the field-dependent rheological properties of MR materials. These environmental phenomena may accelerate the deterioration processes that will affect the long-term rheological reliability of MR materials such as MR elastomer (MRE). This study therefore attempts to investigate the field-dependent rheological characteristics of MRE with corroded carbonyl iron particles (CIPs). The corroded CIPs were treated with hydrochloric acid (HCl) as a way of providing realistic environments in gauging the CIPs reaction towards the ambient conditions. The corroded CIPs along with silicone rubber as a matrix material were used in the fabrication of the MRE samples. To observe the effect of HCl treatment on the CIPs, the morphological observations of MREs with non-corroded and corroded CIPs were investigated via field emission scanning electron microscopy (FESEM), energy-dispersive x-ray spectroscopy (EDX) and x-ray diffractometer (XRD). In addition, the magnetic properties were examined through the vibrating sample magnetometer (VSM), while the field-dependent rheological characteristics such as the storage modulus of MRE with the corroded CIPs were also tested and compared with the non-corroded CIPs. The results showed that the corroded CIPs possessed hydrangea-like structures. In the meantime, it was identified that a sudden reduction of up to 114% of the field-dependent MR effect of MRE with the corroded CIPs was observed as a result of the weakened interfacial bonding between the CIPs and the silicon in the outer layers of the CIPs structure.

Download Full-text