Article
Geochemistry & Geophysics
Torsten Haberzettl, Thomas Kasper, Joseph S. Stoner, Jean Jacques Rahobisoa, Gerhard Daut
Summary: The paleomagnetic records derived from maar lakes in Madagascar provide valuable insights into the paleomagnetic secular variations in (southern) Africa, showing similarities with global geomagnetic field reconstructions and other geological records. These new data help distinguish reliable paleomagnetic data from potentially problematic ones, improving the understanding of paleomagnetic changes in the region.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Weiwei Bian, Tianshui Yang
Summary: Through detailed observation and analysis, we conclude that the paleomagnetic results obtained from the Jingzhushan Formation red beds are reliable and support paleogeographic reconstructions.
Editorial Material
Geochemistry & Geophysics
Qian Zhao, Baochun Huang, Wei Tao
Summary: Bian et al. (2020) studied the paleomagnetism of Late Cretaceous redbeds in the Lhasa terrane and summarized published data, but their interpretations conflict with known geology, highlighting the need for more rigorous structural corrections and evaluation.
Article
Geosciences, Multidisciplinary
Xinxin Sun, Yabo Tong, Zhenyu Yang, Junling Pei, Zijian Zhang, Lifu Hou
Summary: This study focuses on the identification and correction of growth strata in the Miocene Gengma Basin, using paleomagnetic and anisotropy of magnetic susceptibility data. The results show a systematic deviation in the average inclinations of the two sections, indicating the presence of growth strata. The offset angle of the sedimentary fabric can be used to identify and accurately correct the paleo-inclination of the growth strata.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
L. Tauxe, C. N. Santos, B. Cych, X. Zhao, A. P. Roberts, L. Nagy, W. Williams
Summary: The theory for recording of thermally blocked remanences predicts a quasilinear relationship between low fields acquiring magnetization. The requirement for a paleointensity experiment is that a magnetization blocked at a given temperature should be unblocked by zero-field reheating to the same temperature, however, this condition often fails, leading to nonideal experimental behavior and inaccurate field strength estimates. The fragility of unblocking temperature spectra may be related to grain sizes with lower energy barriers and can impact the ability to accurately estimate ancient magnetic field strengths.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Plant Sciences
Marketa Kovarova, Petr Pyszko, Vitezslav Plasek
Summary: The pH of tree bark is influenced by various factors, including epiphytic bryophytes and the inclination of branches. This study found that the effect of bryophytes on the pH of the bark depends on the inclination of branches, with higher inclination leading to a decrease in pH reaction and lower inclination leading to an increase in pH.
Article
Environmental Sciences
Sen Han, Yu Li, Gang Wen, Tinglin Huang
Summary: Thermophoresis has an influence on the deposition characteristics of particles ranging from 1 to 10 micrometers, with the degree of influence depending on particle size and flow condition.
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
(2022)
Article
Multidisciplinary Sciences
Kai Sheng Lee, Rainer Dumke, Tomasz Paterek
Summary: The study found that American cockroaches show increased activity when placed in a periodically rotated Earth-strength magnetic field, whereas this effect diminishes in a stronger field. The magnetite model based on single-domain particles and the assumption that better alignment of magnetic grains yields better sensing and activity in insects is excluded by the data. The radical-pair model explains the results by assuming that a contrast in chemical yield perceivable by the animal and a threshold value for detection exist, with the threshold attained in an Earth-strength field but not in a stronger field.
SCIENTIFIC REPORTS
(2021)
Article
Thermodynamics
Ho Gyun Kang, Jung Hwan Seo, Jeong-Heon Shin
Summary: Numerical analysis was conducted to study the thermal and hydraulic phenomena in an inclined semicircular channel where nitrogen undergoes supercritical state flow. The channel had a semicircular cross-section with a diameter of 2 mm and a length of 350 mm. Different heat fluxes of 20, 40, and 60 kW/m2 were applied to the semicircle, and the inclination angles of the flow channel were varied. The study revealed that under given conditions, the heat flux induced nitrogen to transition into a supercritical state, and the critical point varied with the heat flux. The inclination angle caused significant changes in the physical properties of the heated working fluid, resulting in the appearance of secondary flow and alterations in heat transfer performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Adriano M. Hissanaga, Jader R. Barbosa Jr, Alexandre K. da Silva
Summary: The occurrence of inorganic fouling was numerically investigated using 2-D fully discrete and fully coupled multi-physics turbulence models. The study introduced a novel approach for determining transfer rates based on calculated gradients instead of wall correlations. The results of the study showed that the proposed models were capable of predicting fouling accurately, with better agreement compared to existing models.
APPLIED THERMAL ENGINEERING
(2023)
Article
Geochemistry & Geophysics
Steffen Abe, Hagen Deckert
Summary: The study investigates the influence of stress conditions on the geometry and roughness of fracture surfaces. The results indicate self-affine surfaces with varying Hurst exponents between numerical models and real rock samples. Although stress conditions have some impact on the roughness of fracture surfaces, they have little influence on newly formed fractures.
Article
Agriculture, Multidisciplinary
Xuefeng Song, Fei Dai, Fengwei Zhang, Dengming Wang, Yuchen Liu
Summary: In this study, a new calibration method was developed to calibrate contact parameters commonly used in DEM simulations for fertilizer particles. The input parameters required for the training of the RBFNN were obtained using Latin hypercube sampling and funnel stacking simulations. The results showed that the calibration method accurately reflected the macroscopic motion behavior of the fertilizer particles.
COMPUTERS AND ELECTRONICS IN AGRICULTURE
(2023)
Article
Geochemistry & Geophysics
Edouard G. H. Philippe, Guillaume St-Onge, Jean-Pierre Valet, Pierre-Marc Godbout, Ramon Egli, Pierre Francus, Martin Roy
Summary: The high sedimentation rate sediments' natural remanent magnetization (NRM) provides valuable information about the paleomagnetic secular variation of the Earth's magnetic field and can be used for stratigraphy. However, the acquisition of NRM is dependent on the specific conditions of the depositional environment. Varved sediments, in addition to providing an accurate annual chronology, also reflect significant annual sedimentary changes.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Geosciences, Multidisciplinary
A. Yu. Peskov, A. V. Kudymov, S. V. Zyabrev, A. S. Karetnikov, M. V. Arkhipov, A. I. Tikhomirova, A. N. Didenko
Summary: This study presents the initial findings of paleomagnetic research on Middle Jurassic sedimentary rocks from the Ulban Terrane at coastal outcrops along Ulban Bay. The acquired paleomagnetic data confirm the deposition age and geological significance of the Ulban Terrane rocks.
RUSSIAN JOURNAL OF PACIFIC GEOLOGY
(2021)
Article
Thermodynamics
Xueqiang Shi, Xiaokun Chen, Yutao Zhang, Yuanbo Zhang, Ruizhi Guo, Tenglong Zhao, Rui Liu
Summary: The study investigates the self-ignition and combustion characteristics of coal dust under inclination conditions using a two-step parallel oxidation reaction mechanism, providing a theoretical basis for the prevention and control of coal dust fires. Experimental results show that the self-ignition and combustion process of coal dust can be divided into five stages and the inclination angle affects the minimum ignition temperature, with coal dust deposited under the ceiling being more easily ignited.
Article
Geochemistry & Geophysics
Frantisek Hrouda, Josef Jezek, Martin Chadima
Summary: The calculation of the anisotropy of magnetic susceptibility (AMS) of hematite single crystals using standard linear AMS theory reveals high anisotropy and extremely oblate AMS ellipsoids. The measurements show that the susceptibility along the basal plane is several hundred times higher than that along the c-axis. Despite small but negative minimum principal susceptibility in measured hematite grains, the AMS of multicrystal assemblages is well represented by a tensor after filtering out non-tensorial parts.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
E. Hosseinzadehsabeti, E. C. Ferre, T. B. Andersen, J. W. Geissman, D. Bilardello, G. Di Toro
Summary: This study focuses on pseudotachylytes formed in oceanic peridotites as a result of intraslab seismic rupture, utilizing AMS to reconstruct co-seismic deformation parameters. The findings reveal diverse seismic deformation recorded in these veins with unique insights into the dynamics of frictional melts at high spatial resolution.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geosciences, Multidisciplinary
Mohammad Paknia, Paolo Ballato, Ghasem Heidarzadeh, Francesca Cifelli, Behrooz Oskooi, Joshua Feinberg, Mike Jackson, Dario Bilardello, Francesco Salvini, Majid Mirzaie Ataabadi, Meisam Tadayon, Mohammad Reza Ghassemi, Massimo Mattei
Summary: In this study, anisotropy of magnetic susceptibility (AMS) was combined with fault kinematic analysis and sedimentologic data to analyze deposits of the Upper Red Formation in the intermontane Tarom Basin of NW Iran. The study found that the Miocene extension observed in the basin is not regionally pervasive and not controlled by large-scale processes, suggesting that the normal faults were gravity instabilities induced by sedimentary processes rather than extensional tectonics.
JOURNAL OF ASIAN EARTH SCIENCES
(2021)
Article
Astronomy & Astrophysics
Dario Bilardello
Summary: The study conducted magnetic and rock-magnetic research on sedimentary rocks in the state of Sao Paulo, Brazil, confirming the rocks were largely remagnetized during the Cretaceous. Analysis of AMS showed that it records primary sedimentary fabrics reflecting depositional environments and paleocurrent conditions of the rocks.
EARTH AND SPACE SCIENCE
(2021)
Article
Geochemistry & Geophysics
Josef Jezek, Frantisek Hrouda
Summary: By investigating the anisotropy of in-phase and out-of-phase magnetic susceptibility, the study sheds light on the characteristics of AC magnetic susceptibility in rocks and minerals caused by eddy currents. The results show that EC susceptibility is strongly frequency dependent and closely related to the shape of the materials.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Frantisek Hrouda, Jan Franek, Stuart Gilder, Martin Chadima, Josef Jezek, Stepanka Mrazova, Michal Ponavic, Martin Racek
Summary: Single crystals of graphite demonstrate strong crystalline anisotropy and diamagnetism, with magnetic susceptibility measured in alternating fields showing both in-phase and out-of-phase components. The study of anisotropy of magnetic susceptibility in graphite ore provides insight into the preferred orientation of graphite and the presence of paramagnetic and ferromagnetic minerals within the rock. The high opAMS degree and lineation perpendicular to metamorphic foliation suggest a significant LPO of graphite, likely formed during Variscan regional metamorphism.
JOURNAL OF STRUCTURAL GEOLOGY
(2022)
Article
Environmental Sciences
Viktor Golias, Lenka Hajkova, Tomas Lipansky, Tomas Cernik, Pavel Kohn, Josef Jezek, Radek Prochazka, Tadeusz A. Przylibski, Jiri Dohnal, Ladislav Strnad, Agata Kowalska, Lidia Fijalkowska-Lichwa, Wojciech Mista, Robert Nowakowski
Summary: Radioactive (radon) groundwaters are highly valued for their healing effects. A large exploratory event conducted in Czech-Polish cooperation discovered numerous sources of mineral radioactive waters with high radon activity concentrations. Some of these sources have significant balneological potential and are gaining popularity among the public.
Article
Geochemistry & Geophysics
Shishun Wang, Liao Chang, Chunhui Tao, Dario Bilardello, Long Liu, Tao Wu
Summary: This study investigates the post-crystallization alterations of titanomagnetites in mid-ocean ridge basalts (MORB) through comprehensive rock magnetic and electron microscopic analyses. The research reveals the variations in magnetomineralogy and magnetic properties with progressive hydrothermal alteration, providing insights into the complexity of seafloor magnetism. The established framework allows for characterizing MORB hydrothermal alteration and contributes to resolving the long-term magnetization variations in oceanic basalts.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Luigi Vigliotti, Dario Bilardello, Aldo Winkler, Paola Del Carlo
Summary: A detailed rock magnetic study was conducted on ash samples from different explosive activities of Mount Etna. The study found that magnetic properties can be used as effective factors for discriminating among different eruptive products. The more explosive products were characterized by oxidized Ti-rich titanomagnetites, higher coercivity distributions, and higher magnetizations and susceptibilities. Additionally, the magnetic properties of tachylite-bearing tephra provided a useful tool for studying the fragmentation process and explosive character of volcanic activities.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geology
Shah Wali Faryad, Josef Jezek, Jan Kulhanek
Summary: This study presents the petrological observations and diffusion modelling results of garnet from high-pressure to ultrahigh-pressure metamorphic rocks in the Western Gneiss Region. The results reveal the evolution of Pre-Caledonian granulite facies and Caledonian eclogite facies metamorphic events in these rocks, with preservation of compositional gradients and relaxation processes. Calculations indicate a pressure of up to 2.6 GPa and a temperature of 650 degrees C during the eclogite facies event. The study also provides insights into the cooling rate and exhumation rate of the rocks during their geological history.
JOURNAL OF METAMORPHIC GEOLOGY
(2022)
Article
Geochemistry & Geophysics
Shah Wali Faryad, Josef Jezek, James A. D. Connolly
Summary: This paper presents the application and results of phase diagram and diffusion modelling for constraining metamorphic P-T paths. It discusses the differences between measured garnet zoning profiles and those calculated by phase diagram modelling, as well as the quantification of diffusion in high-grade rocks. The approach allows for the deciphering of reasons behind the discrepancies and the constraint of P-T paths in high-grade rocks.
JOURNAL OF PETROLOGY
(2022)
Article
Geochemistry & Geophysics
Frantisek Hrouda, Josef Jezek, Martin Chadima
Summary: This study investigated the unknown anisotropic properties of out-of-phase magnetic susceptibility (opMS) of hematite and their impact on understanding the origin of hematite magnetism. The research found that opMS shows strong field dependence along the basal plane and weak field dependence along the c-axis. The study also revealed that the second rank tensor is only an approximate representation of the directional opMS of hematite single crystals, and the distribution of measured and theoretical values differs significantly.
STUDIA GEOPHYSICA ET GEODAETICA
(2022)
Article
Geochemistry & Geophysics
Wentao Huang, Shanshan Niu, Mark J. Dekkers, Peter C. Lippert, Dario Bilardello, Peat Solheid, Bo Zhang, Guillaume Dupont-Nivet, Douwe J. J. van Hinsbergen, Lin Ding
Summary: Paleomagnetic investigations of Paleocene lavas from Dianzhong Formation in Linzhou basin of southern Lhasa terrane are essential for determining the timing and paleolatitude of the initial India-Asia collision. However, controversy exists regarding the preservation of primary remanent magnetization in these rocks. This study finds that hydrothermal alteration has significantly impacted the original magnetic carrier, resulting in the contamination or replacement of the primary remanence by thermoviscous and chemical remanent magnetizations.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Review
Geosciences, Multidisciplinary
Frantisek Hrouda, Martin Chadima, Josef Jezek
Summary: This article focuses on the characteristics of AC magnetic susceptibility in anisotropic materials, as well as the definitions and measurement methods of ipAMS and opAMS. In minerals with non-zero opMS, opAMS can be used as a tool for direct determination of magnetic sub-fabrics.
Article
Geosciences, Multidisciplinary
Roger R. Fu, Michael W. R. Volk, Dario Bilardello, Guy Libourel, Geoffroy R. J. Lesur, Oren Ben Dor
Summary: The study suggests that the magnetization of the Allende carbonaceous chondrite meteorite may have originated from reactions between Fe-bearing minerals and aqueous fluids on the parent asteroid around 3.0-4.2 million years after solar system formation, in a magnetic field of >40 mu T. This supports the idea that the early solar system's magnetic field had a nebular origin rather than dynamo or solar wind alternatives.