Search Results (139)

Fine-grained sedimentary rocks are ideal carriers for astronomical cycle analysis as they can record and preserve significant astronomical cycle signals. Spectral analysis using the Multi-taper Method (MTM) and Evolutionary Harmonic Analysis (EHA) using the Fast Fourier Transform (FFT) were conducted on natural gamma data from key wells in the Es₃l sub-member in the Bonan Sag, Bohai Bay Basin, China. Gaussian bandpass filtering was applied using a short eccentricity cycle of 100 ka, and a “floating” astronomical time scale for the Es₃l sub-member (Lower 3rd sub-member of Shahejie Formation in Eocene) was established using magnetic stratigraphic ages as boundaries. Stratigraphic divisions were made for single wells in the Es₃l of the Bonan Sag, and a stratigraphic framework was established based on correlations between key wells. The research results indicate the following: Firstly, the Es₃l of the Bonan Sag records significant astronomical cycle signals, with an optimal sedimentation rate of 8.39 cm/ka identified. Secondly, the cyclical thicknesses corresponding to long eccentricity, short eccentricity, obliquity, and precession cycles are 38.9 m, 9.7 m, 4.6–3.4 m, and 1.96–1.66 m, respectively. Thirdly, the Es₃l sub-member stably records 6 long eccentricity cycles and 26 short eccentricity cycles, and the short eccentricity curve is used as a basis for stratigraphic division for high-precision stratigraphic correlations. Fourthly, the quality of sandstone-interbedded mudrock is jointly controlled by the short eccentricity and precession. Eccentricity maximum values result in thicker sandstone interlayers, while minimum precession values promote the thickness of sandstone interlayers. Through astronomical cycle analysis, the depositional evolution mechanism of sandstone-interbedded mudrock is revealed. Combined with the results of high-precision stratigraphic division, this can provide a basis for fine evaluation and “sweet spot” prediction of lacustrine shale oil reservoirs. Full article

The geopolitical and economic situation impacts raw materials demand. As principal ore deposits reach exhaustion, the study of new sources of raw materials becomes essential. Therefore, mining wastes emerge as alternative sources of raw materials. Their physicochemical properties, such as small particle size or concentration of some metals of interest, enhance reprocessing. A number of critical raw materials (As, Co, Cu, Sb) and base metals (Pb, Zn), as well as precious metals (Ag), were found present in an abandoned tailing deposit composed by finely grounded washed roasted pyrites within the Iberian Pyrite Belt. Copper leaching from a sample of this deposit was investigated. Two hydrometallurgical approaches were studied: acidic leaching with and without activated carbon; and alkaline leaching with glycine solutions. Leaching tests were carried out during 24 h at ambient and moderate temperatures (60 °C). In acidic medium, the maximum copper extraction varied from 88 to 92.5%, while in alkaline medium, the maximum copper extraction was in the range of 71%–76%. Using activated carbon and H₂O₂ seemed to slightly promote the copper extraction with the maximum extraction (92.5%) after 2 h of leaching at 60 °C. Complementarily, above 50% of the zinc and cobalt contained were extracted. In contrast, temperature in alkaline conditions played a key role in reaction speed, but also in precipitation of copper insoluble compounds. In addition, the glycine solution at pH 10–10.5 showed high selectivity for copper over zinc, iron, lead, arsenic, and antimony. Two extra tests at pH above 12 showed arsenic dissolution (up to 51% at pH 12.5). Full article

Thermoplasmonic heat generation by silver (Ag) nanoparticles can harness visible light to efficiently produce localized heating. Flame spray pyrolysis (FSP) is a powerful one-step synthesis technology for fabricating plasmonic Ag-based nanostructures. In the present study, we employed FSP to engineer core@shell Ag@SiO₂ nanoparticles coated with an ultrathin (1–2 nm) silica (SiO₂) nanolayer in a single step in tandem with their deposition as films onto solid substrates. Accordingly, we engineered a library of Ag@SiO₂ nanofilms with precisely controlled thicknesses in the range of 1–23 μm. A systematic study of the thermoplasmonic heat-generation efficiency (ΔT) of the films under visible-light irradiation (LED, λ = 405 nm) revealed that the films’ compactness and thickness are key parameters governing the heat-generation efficiency and thermal response rate. Moreover, we show that the substrate type can also play a key role; Ag@SiO₂ films on glass-fiber filters (PGFFs) enabled faster temperature increase (dT/dt) and a higher maximum temperature gain (ΔT_max) compared with Ag@SiO₂ films on glass substrates (PGSs). The photothermal conversion efficiencies were approximately 60%, with the highest efficiency (η = 65%) observed in the thinner impinged film. This study demonstrates that FSP-derived Ag@SiO₂ nanofilms provide a versatile and scalable platform for thermoplasmonic heat generation applications with significant industrial potential. Full article

The Sredogriv greenschist facies rocks belong to the Western Balkan Zone in northwestern Bulgaria. The low-grade rocks consist of clastic-tuffaceous precursors and presumably olistostromic magmatic bodies. We present U-Pb LA-ICP-MS zircon age constraints for the Sredogriv metaconglomerate, intruding metaalbitophyre and a breccia-conglomerate of the sedimentary cover. Detrital zircons in the Sredogriv metaconglomerate yield a maximum depositional age of 523 Ma, with a prominent NeoproterozoicEarly Cambrian detrital zircon age clusters derived from igneous sources. The metaalbitophyre crystallized at 308 Ma and contains the same age clusters of inherited zircons. A 263 Ma maximum age of deposition is defined for a breccia-conglomerate of the Smolyanovtsi Formation from the sedimentary cover that recycled material from the Sredogriv metamorphics and Carboniferous–Permian magmatic rocks. The depositional setting of the Sredogriv sedimentary succession is characterized by proximity to Cadomian island arc sources and provenance from the northern periphery of Gondwana. The timing of the Variscan greenschist facies metamorphism of the Sredogriv metamorphics is bracketed between 308 Ma and the depositional age of 272 Ma of another adjacent clastic formation. These results constrain the timing of the Cadomian sedimentary history and the Variscan magmatic and tectono-metamorphic evolution in this part of the Western Balkan Zone. Full article

Episodic sedimentary processes with significant changes in sedimentation rate have occurred on the East Hainan Coast, the inner shelf of the South China Sea, since the Last Glacial Maximum. In particular, the early-Holocene (~11.5–8.7 ka) rapid sedimentation at a mean rate of ~4.90 m/ka is crucial to understand the processes of terrigenous input to the ocean, carbon cycling and climate control in coastal-neritic sedimentary evolution. However, the chronological framework and the detailed environmental evolution remain uncertain. In this study, core sediments collected from the East Hainan Coast (code: NH01) were used to revisit the characteristics of luminescence signals by comparing the dating results using the blue-light stimulated luminescence (blue-OSL) ages and previously published post-infrared blue-light stimulated luminescence (pIR-blue OSL) ages. The results showed that both the ages agreed with each other for the fine-grained quartz fraction. The refined chronology of the early-Holocene deposits on the East Hainan Coast with higher resolution suggested that the sedimentation rate was ~0.60 m/ka before 10.97 ka, while it increased abruptly to ~5.89 m/ka during the period of 10.97–9.27 ka. According to the refined OSL chronology and the high-resolution (~2.5 cm) titanium intensity using X-ray fluorescence (XRF) scanning, the rapid sedimentation during the early Holocene was likely controlled by increased terrigenous input. The variation in Ti flux reflected the differential response between two meltwater pulse (MWP) events under the combined effects of enhanced early-Holocene monsoons and localized freshwater input. These findings highlight the compound controls of global ice-volume change, monsoon dynamics and coastal geomorphic evolution on sedimentary processes. Full article

The Kumishi ophiolitic mélange contains well-preserved large-scale serpentinites and their accompanying granulites in the eastern South Tianshan Accretionary Complex (STAC), southwestern Altaids. Previous studies have mainly focused on the thermodynamic conditions and tectonic setting of granulites. However, the petrogenesis of the widespread serpentinites in the Kumishi ophiolitic mélange remains largely unexplored. In this paper, petrological, geochemical, and geochronological studies were carried out on the Kumishi serpentinites, as well as the host sediment and intermediate–felsic volcanic rocks. The serpentinites show variable LOI values of 8.3–16.5 wt% and relatively consistent SiO₂/(sum oxides) ratios of 0.81, which demonstrate that the major elements of their protoliths have been preserved well during serpentinization. Multi-trace element and REE diagrams suggest that the protoliths of the Kumishi serpentinites have experienced varying degrees of refertilization, with distinct natures seen between the Yushugou, Tonghuashan, and Liuhuangshan serpentinites. Zircon U-Pb chronology of the Tonghuahsan serpentinites yields a mean age of 355.8 ± 7.3 Ma (MSWD = 1.0, N = 26). Detrital zircons from the host sediment record a maximum depositional age of 375 ± 10 Ma (MSWD = 0.4, N = 3), with a peak at ca.419 Ma. Subduction-related volcanic rocks yield ages of ca.437 Ma. Hence, clues are provided to the petrogenesis of the Kumishi serpentinites, with calls for future in-depth works from an isotopic perspective. Full article

In order to better constrain the specific depositional age and provenance of the Danzhou Group and understand the geological evolution of the Jiangnan Orogenic Belt, we conducted a combined U-Pb and Hf-isotope analysis of detrital zircons from the Gongdong and Hetong formations of the Danzhou Group in the Longsheng area of the Western Jiangnan Orogenic Belt. Detrital zircons from the Gongdong Formation yield three age populations of 2658–2517 Ma, 2427–1678 Ma and 891–781 Ma, and the youngest ages suggest that the sedimentation began after ca. 783 Ma. U-Pb ages of detrital zircons from the Hetong Formation yield major populations at 2769–2502 Ma, 2492–2100 Ma, and 991–731 Ma, and the youngest ages redefine the maximum depositional age of this unit is 760 Ma, much younger than previously considered. Thus, the upper part of the Hetong Formation in the Longsheng area is newly subdivided into the Sanmenjie Formation, which is characterized by a large amount of 765–761 Ma volcanic rocks. The dominant 991–731 Ma detrital zircons for all samples were likely sourced from the Neoproterozoic igneous rocks of the southeast margin of the Yangtze Block. The subordinate 2494–1678 Ma detrital zircons were probably sourced from the Cathaysia Block. Minor amounts of 2769–2502 Ma detrital zircons may have been sourced from the Yangtze Block. Detrital zircons from the Gongdong Formation have mainly negative εHf (t) values (−1.1 to 21.8, 90%), suggesting that the detritus of the Gongdong Formation is dominated by the recycling of old crustal materials. The εHf (t) values of detrital zircons from the Hetong Formation have a large spread of −22.2 to +9.7, indicating that the source material of the Hetong Formation includes both the juvenile crustal materials and the recycled ancient crustal materials. The above age populations and Hf isotopic characteristics are consistent with the magmatic rocks in the Jiangnan Orogenic Belt and the Southeast Yangtze Block. Taking into account the lithostratigraphic features, provenances, and depositional ages, the Danzhou Group in the Western Jiangnan Orogenic Belt was deposited in a back-arc basin. Full article

The integration of perovskite with silicon for constructing tandem solar cells (TSCs) represents a promising route in photovoltaic technology. The hybrid sequential deposition (HSD) method, combining thermal evaporation and spin-coating, is crucial for developing perovskite films in textured perovskite/silicon tandem solar cells. However, the process faces challenges due to incomplete reactions caused by the dense perovskite coverage layer (CPCL) formed from high-crystallinity precursors. The CPCL hinders the diffusion of organic salts into the bottom precursor layer, leading to performance degradation and accelerated device aging. Herein, this study explores several polar solvents as additives to n-butanol (nBA) solvent in order to enhance the permeability of organic salts through the CPCL, and we demonstrate that dimethyl sulfoxide (DMSO) as an additive solvent can effectively assist organic salts in rapidly diffusing through the precursor layer, thereby promoting the complete transformation of uniform perovskite crystals. The resulting perovskite films exhibited complete conversion, uniform crystallization, and improved quality. As a result, the target TSCs achieved an increased maximum power conversion efficiency (PCE) of 29.12%. This study offers a robust pathway for depositing high-quality perovskite films on industrial-grade textured silicon substrates, laying a solid foundation for advancing perovskite/silicon tandem solar cells technology. Full article

Thoracoabdominal aortic aneurysms (TAAAs) are rare but serious conditions characterized by dilation of the aorta characterized by remodeling of the vessel wall, with changes in the elastin and collagen content. Individuals with Marfan syndrome have a genetic predisposition for elastic fiber fragmentation and elastin degradation and are prone to early aneurysm formation and progression. Our objective was to analyze the medial collagen characteristics through histological, polarized light microscopy, and electron microscopy methods across the thoracic and abdominal aorta in twenty-five patients undergoing open surgical repair, including nine with Marfan syndrome. While age at surgery differed significantly between the groups, maximum aortic diameter and aneurysm extent did not. Collagen content increased from thoracic to infrarenal segments in both cohorts, with non-Marfan patients exhibiting higher collagen percentages, notably in the infrarenal aorta (729.3 nm vs. 1068.3 nm, p = 0.02). Both groups predominantly displayed mature collagen fibers, with the suprarenal segment containing the highest proportion of less mature fibers. Electron microscopy revealed comparable collagen fibril diameters across segments irrespective of Marfan status. Our findings underscore non-uniform histological patterns in TAAAs and suggest that ECM remodeling involves mature collagen deposition, albeit with lower collagen content observed in the infrarenal aorta of Marfan patients. Full article

The Lake Faro brackish basin (Sicily, Italy) was established as a Global Geosite as a key locality of tectonic coastal lakes, but little research has been devoted to this rare geological and ecological framework. To fill this gap, the main stratigraphical, sedimentological, ecological, morpho-bathymetric, and structural features were reported, linking geodiversity with biodiversity. In Lake Faro, a shallow platform develops alongside a deep funnel-shaped basin, reaching a maximum depth of 29 m. A NNW-SSE trending steep cliff, representing the abrupt transition from the platform to the basin, was interpreted as a dextral transtensional fault (Lake Faro Fault), presumably active since the middle-late(?) Pleistocene. The switches of the steep cliff NW-wards, acquiring an E-W trend, was interpreted as being due to the occurrence of the normal Mortelle Fault, cut by the Faro Lake Fault. Bottom terrigenous deposits consisted of coarse- to fine-grained quartzo-lithic rich sediments deriving from high-grade metamorphic and igneous rocks, whereas bioclasts mainly derived from clam farming actives for several centuries up until today. The Quaternary shallow platform, from top to base, includes the following: (i) soft cover composed of coarse terrigenous and prevalent bioclastic deposits; (ii) hard conglomerates cemented by carbonates; and (iii) siliciclastic coarse deposits of the Messina Fm. In the deep basin, siliciclastic silty loams with minor amounts of bioclastic deposits prevailed in the soft cover. Substrate heterogeneity coupled with brackish-marine gradients are the main factors responsible for an articulate patchiness of different lagoon habitats and related benthic associations, which, according to the Barcelona Convention classification, can be summarized as follows: (i) MB1.541 (marine angiosperms or other halophytes), (ii) MB1.542 (Fucales), (iii) MB5.543 (photophilic algae, except Fucales), (iv) MB5.544 (Facies with Polychaeta), and (v) MB5.545 (Facies with Bivalvia). Typical marine associations, such as rhodolite beds, also occur. Finally, the lake, which has been exploited since the prehistoric age because of its high biodiversity and productivity, maintains some evidence of millennial relationships with the resident human cultures, attracted there by the favorable geomorphological and ecological peculiarities. Full article

In this experiment, plasma-enhanced chemical vapor deposition technology was used to deposit diamond-like carbon thin films on the surface of a 2024 aluminum alloy. The effects of deposition temperature on the microstructure, carbon, silicon, and aluminum element distribution, and film substrate adhesion of diamond-like carbon thin films were studied using field emission scanning electron microscopy, energy-dispersive spectroscopy, XRD, scratch gauge, and ultra-depth-of-field microscopy. The results showed that with the increase in deposition temperature, the thickness of DLC film decreased from 8.72 μm to 5.37 μm, and the film bonded well with the substrate. There is a clear transition layer containing silicon elements between the DLC film and the aluminum alloy substrate. The transition layer is a solid solution formed by aluminum and silicon elements, which increases the bonding strength between the film and substrate. C-Si and C-C exist in the form of covalent bonds and undergo orbital hybridization, making the DLC film more stable. When the deposition temperature exceeds the aging temperature of a 2024 aluminum alloy, it will affect the properties of the aluminum alloy substrate. Therefore, the deposition temperature should be below the aging temperature of the 2024 aluminum alloy for coating. At a deposition temperature of 100 °C, the maximum membrane substrate bonding force is 14.45 N. When a continuous sound signal appears and the friction coefficient is the same as that of the substrate, the film is completely damaged. From the super-depth map of the scratch morphology, it can be seen that, at a deposition temperature of 100 °C, a small amount of thin film detachment appears around the scratch. Full article

The Storegga slide tsunami (SST) at ca. 8100 ± 100–250 cal BP is known to be the largest tsunami that affected the North Sea during the entire Holocene. Geological traces of tsunami landfall were discovered along the coasts of Norway, Scotland, England, Denmark, the Faroes and Shetland Islands. So far, the German North Sea coast has been considered as being well protected due to the wide continental shelf and predominant shallow water depths, both assumed to dissipate tsunami wave energy significantly, thus hindering SST propagation dynamics. The objective of our research was to clarify if the SST reached the German Bight and if corresponding sediment markers can be found. Our research was based on the in-depth investigation of a 5 m long section of the research core Garding-2 from Eiderstedt Peninsula near Garding in North Frisia known from a previous study. For this, we newly recovered sediment core Garding-2A at exactly the same coring location as core Garding-2. Additionally, high-resolution Direct Push sensing data were collected to gain undisturbed stratigraphic information. Multi-proxy analyses of sediment material (grain size, geochemical, geochronological and microfaunal data) were carried out to reconstruct palaeoenvironmental and palaeogeographical conditions. We identified a high-energy event layer with sedimentological (e.g., erosional unconformity, rip-up clasts, fining-upward), microfaunal (e.g., strongly mixed foraminiferal assemblage) and other features typical of tsunami influence and identical in age with the SST, dated to ca. 8.15 ka cal BP. The event layer was deposited at or maximum ca. 1–1.5 m below the local contemporary relative sea level and several tens of kilometers inland from the coastline within the palaeo-Eider estuarine system beyond the reach of storm surges. Tsunami facies and geochronological data correspond well with SST signatures identified on the nearby island of Rømø. SST candidate deposits identified at Garding represent the southernmost indications of this event in the southeastern North Sea. They give evidence, for the first time, of high-energy tsunami landfall along the German North Sea coast and tsunami impact related to the Storegga slide. SST deposits seem to have been subsequently reworked and redeposited over centuries until the site was affected by the Holocene marine transgression around 7 ka cal BP (7.3–6.5 ka cal BP). Moreover, the transgression initiated energetically and ecologically stable shallow marine conditions within an Eider-related tidal channel, lasting several millennia. It is suggested that the SST was not essentially weakened across the shallow continental shelf of the North Sea, but rather caused tsunami run-up of several meters (Rømø Island) or largely intruded estuarine systems tens of kilometers inland (North Frisia, this study). We, therefore, assume that the southern North Sea coast was generally affected by the SST but sedimentary signals have not yet been identified or have been misinterpreted. Our findings suggest that the German North Sea coast is not protected from tsunami events, as assumed so far, but that tsunamis are also a phenomenon in this region. Full article

A multifunctional sensor comprising flexible and transparent ultraviolet (UV) photodetectors (PDs) with strain gauges based on Ag nanowire (AgNW)@ZnO nanorods (ZnONRs) was fabricated using a cost-effective, simple, and efficient method. High-aspect ratio silver nanowires were synthesized using the polyol method. An AgNW@ZnONR composite was formed via the hydrothermal method to ensure the multifunctional capability of the flexible sensors. After refining the process parameters, the size of the ZnO nanorods was decreased to fabricate pliable multifunctional sensors using AgNW@ZnONRs. At a deposition of 0.207 g of AgNW@ZnONRs, the sensor achieves its maximum switching ratio and fastest response time under conditions of 2000 μW/cm² UV optical power density. With a t_on (rise time) of 2.7 s and a t_off (fall time) of 2.3 s, the ratio of I_on to I_off current is 1151. Additionally, the sensor’s maximum optical current value correlates linearly with UV light’s power density. The maximum response current increased from 222.5 pA to 588.1 pA, an increase of 164.3%, when the bending angle was increased from 15° to 90° for the sensor with a deposition of 0.276 g of AgNW@ZnONRs. There was no degradation in the response of the sensors after 10,000 bending cycles, as they have excellent stability and repeatability, which means they can meet the requirements of wearable sensor applications. Therefore, there is great potential for the practical application of multifunctional AgNW@ZnONRs in flexible sensors. Full article

Detrital zircons from two samples of metasandstones from the Lykhmanivka Syncline, Middle Dnieper Domain of the Ukrainian Shield (Skelevate Formation of the Kryvyi Rih Group), have been dated by the LA-ICP-MS U-Pb method. Metasandstones from the northern part of the syncline yield zircons belonging to four age groups: 3201 ± 12 Ma, 3089 ± 11 Ma, 2939 ± 8 Ma, and 2059 ± 4 Ma. All three Archean groups originated from similar rock types that crystallized at different times from the same mafic source (lower crust) with a ¹⁷⁶Lu/¹⁷⁷Hf ratio of about 0.020. In contrast, zircon from metasediments from the southern end of the Lykhmanivka Syncline fall within two age groups: 3174 ± 13 Ma, and 2038 ± 9 Ma. In terms of Hf isotope compositions, the detrital zircons from the two oldest age groups in both samples are very similar. The source area was dominated by rocks of the Auly Group (3.27–3.18 Ga) and the Sura Complex (3.17–2.94 Ga). The proportion of zircons dated at 2.07–2.03 Ga, which reflects the timing of metamorphism, is 5%. The metamorphic nature of the Paleoproterozoic zircon allows us to define the maximum depositional age of the metasandstones of the Lykhmanivka Syncline at ca. 2.9 Ga, which is in good agreement with the earlier results from the metaterrigenous rocks of the Kryvyi Rih–Kremenchuk Basin. Our data also indicate the local nature of sedimentation and the absence of significant transport and mixing of detrital material within the basin. Full article

This paper describes the design and development of a novel electrochemical biosensor for measuring glycerol in wine. Our initial detailed studies were aimed at deducing the optimum conditions for biosensor operation by conducting hydrodynamic voltammetric and amperometric studies. The resulting voltammograms revealed a maximum electrocatalytic current at 0.0 V vs. Ag/AgCl, which we used for all further studies. We also examined the effect of pH (8–10) on the amperometric responses of different glycerol concentrations over a range of 0.04 to 0.20 mM. Based on our findings, we propose that pH 9 would be suitable as the supporting electrolyte for further studies with the amperometric biosensor. The biosensor was constructed by immobilising 10 units of GLDH and 660 μg NAD⁺ onto the MB-SPCE surface using glutaraldehyde (GLA) as a cross-linking agent. Calibration studies were performed with glycerol over the 1.0–7.5 mM concentration range. Chronoamperometry was the electrochemical technique chosen for this purpose as it is convenient and can be performed with only 100 μL of sample directly deposited onto the biosensor’s surface. In the current study, we observed linear calibration plots with the above standard solutions using current measurements at a selection of sampling times along the chronoamperograms (30–340 s). We have evaluated the glycerol biosensor by carrying out an analysis of commercially available red wine. Overall, these findings will form a platform for the development of novel rapid technology for point-of-test evaluation of glycerol in the production and quality control of wine. Full article