Miracle-dz/UniFAR-FTUs huggingface dataset:
Centrifuge modelling of heating effects on energy pile performance in saturated sand

The operation of energy pile in summer can expel excessive heat of the buildings into the ground by the use of a heat pump. Despite of having been implemented for decades, the design of energy pile still relies heavily on empiricism as there is still limited understanding about heating effects on pile capacity. A series of centrifuge model tests in saturated sand is reported in this study to investigate heating effects on the settlement patterns as well as capacities of single piles. In total, four in-flight pile load tests under different temperatures (i.e. 22℃, 37℃ and 52℃) were carried out. Variations of pile capacity were interpreted with the help of a non-linear elastic analysis. The test results show that after heating at zero applied axial load, toe resistance of pile was mobilized as a result of constrained downward thermal expansion of pile. Heating to a higher temperature caused thermally induced the neutral plane (NP) to shift towards the pile toe. It is also found that for pile under a maintained working load, a temperature increase of 30℃ made the pile head initially heave by 12.5 mm and gradually settle by 5.1 mm after 4 months of continuous heating. The post pile settlement is believed to be caused by thermal contraction of sand. Subsequent pile load tests showed that pile capacity increased by 13% and 30% with an incremental temperature of 15℃ and 30℃, respectively. With an increasing temperature, shaft resistance increased but at with a reducing rate. At a higher temperature increment, In contrast, toe resistance increased more rapidly than shaft resistance due to a larger downward expansion of the pile at higher temperature increment. For simplicity, earth pressure coefficient with a value of 1.1K0 and 1.3K0 was found to be suitable for estimating the capacity of model pile with a temperature increment of 15℃ and 30℃, respectively.
Validation of POAM III aerosols: Comparison to SAGE II and HALOE

We describe statistical comparisons between Polar Ozone and Aerosol Measurement (POAM) III and Stratosphere Aerosol and Gas Experiment (SAGE) II measurements of aerosol extinction in 1998 and 1999. SAGE II and POAM III are in qualitative agreement, and show that since the launch of POAM III in March of 1998, stratospheric aerosol extinctions at visible and near-IR wavelengths have remained at background levels. We present quantitative differences between the SAGE II and POAM III extinctions at 1.02 μm and 0.45 μm for temporally and spatially coincident measurements. At 1.02 μm the instruments agree to within about ±30% from 10 to 22 km, where most of the aerosol extinction lies. Differences at 0.45 μm are similar to 1.02 μm in the southern hemisphere, but much larger in the northern hemisphere. We show that differences between SAGE II and POAM III slant path optical depths closely resemble the aerosol extinction differences at 1.02 μm, but not at 0.45 μm. On the basis of these results we conclude that the aerosol extinction differences at 1.02 μm arise from differences in the slant path optical depth measurements of the two instruments, not from species separation differences in the retrieval algorithms. However, we tentatively attribute the aerosol extinction differences at 0.45 μm to an error in the NO2/aerosol species separation in the SAGE II retrievals. We present theoretical simulations incorporating the maximum plausible systematic pointing or timing errors in the POAM III instrument. We conclude that these errors cannot explain the 1.02 μm optical depth or aerosol extinction differences, although it is possible that they contribute to the observed differences. We thus attribute these differences to fundamental radiometric differences between POAM III and SAGE II that remain to be resolved. We also compare derived surface areas and volume densities from POAM III, SAGE II, and the Halogen Occultation Experiment (HALOE). The statistical differences can be explained by the aerosol extinction differences in the SAGE II comparisons, and by the lack of sensitivity on the part of POAM III and SAGE II to very small aerosols in the HALOE comparisons. Nevertheless, we show qualitative agreement between all three instruments. The results presented here show that the POAM III aerosol measurements are valid for scientific studies.
Single-use Plastics: Legal Perceptions and Self-Reported Behavior in Vietnam

Plastic pollution has become a serious global threat to ecosystems, human health, and economies, particularly in countries with coastlines such as Vietnam. The 3R approach (reduce, reuse, recycle) has been recognized as an important strategy to minimize plastic waste and reduce the risk of plastic entering the ocean. However, changing single-use plastic consumption habits is a great challenge that requires awareness, education and action. This study uses mixed methods, including a survey and semi-structured interviews, to explore: 1) Single-use plastic consumption and 3R behaviors of Vietnamese people; 2) How they perceive the current environmental regulation enforcement; and 3) How they perceive the role of stakeholders in the plastic problem. A self-nominated sample of 202 participants residing in Hoi An City, Ha Noi Capital and Ho Chi Minh City responded to the survey, and in-depth interviews were conducted with ten key informants (including workers from the public and private institutions, citizens and researchers). The results suggest that the convenience, affordability, availability and durability of plastics are the drivers of consumption, while legal bans, health and environmental concerns are motivators of reduction. For 3R behaviors, the participants reported the highest level of recycling, followed by reducing and reusing, acknowledging the help of Vietnamese traditional habits such as selling “ve chai” (recyclables) and using “cặp lồng” (inox food containers) for their 3R behaviors. Finally, the participants observed that penalties for plastic littering are low and too leniently enforced, especially for businesses. They also believed that stakeholders, including businesses, governments, and consumers are the main actors in tackling the single-use plastic waste problem. This study provides some recommendations based on these findings.
Measuring the permeability of magnetic materials in the GHz region

Magnetic materials have always been important in the commercial world and, as our transport systems are switching to electrification from fossil fuels, they are likely to become more so. Relative permeability, μ r, is one parameter which characterizes such materials and this article discusses some measurements of μ r, made on powdered iron oxide and two ferrite magnetic materials. Preliminary measured values of μ r range from 1.5 to 4 and the imaginary part of μ r, show that magnetic losses occur in the GHz region. An idea for improved measurements is suggested.
Role of fungi in the formation of siliceous coated grains, Waiotapu geothermal area, North Island, New Zealand

Siliceous coated grains (oncoids) are common on parts of Primrose Terrace, which is a large sinter apron below Champagne Pool in the Waiotapu geothermal area of North Island, New Zealand. Some oncoids are discoidal with smooth exteriors (Group I), whereas others have clusters of microstromatolites growing upon their surfaces (Group II). The microstromatolites normally began to form when the upper surfaces of the discoidal oncoids had reached mean water level. Growth of the cortical laminae in the oncoids and microstromatolites was mediated by a diverse biota that is dominated by fungi, with subsidiary bacteria (including cyano-bacteria) and diatoms. Pollen grains from Pinus radiata, which are common in some cortical laminae, nourished some of the fungi. Collectively, the microbes mediated growth of the oncoids by providing templates for silica precipitation. Most silica oncoids formed in shallow (<1 cm) flowing water that probably had a temperature of approximately 15-20 degrees C and pH of 3-6. Seasonal variations in the water temperature and pH were probably responsible for the cyclic variations in the fabrics of the cortical laminae. Laminae rich in microbial remains formed during the spring and summer months when the warmer waters allowed the microbes to flourish. Cooler waters in the fall and winter led to the demise of some microbes and the development of thinner cortical laminae with few microbial remains.
Exchange processes and nitrogen cycling on the shelf and continental slope of the Black Sea basin

A 3D coupled biogeochemical‐hydrodynamical model has been applied to the Black Sea to simulate nitrogen cycling and to estimate the exchange of biogeochemical components at the shelf break and between the continental slope and the deep sea. It was found that biological processes on the northwestern shelf are in approximate balance. Primary production is fueled by river discharge, nitrate input from the open sea at the shelf break, and in situ remineralization. The input of nitrate from the open sea is roughly equivalent to the river nitrate discharge but is half the nitrate export from the shelf toward the open sea. Also, the Black Sea shelf acts throughout the year as a nitrate source for the open sea. The amount of shelf production not remineralized in the euphotic layer is 22.2% and is exported to lower layers (20%) or offshore (2.2%). We estimate that the export of carbon from the shelf to the interior of the basin represents 2.5% of the new production of the open sea. The upper slope adjoining the northwestern shelf is the site of downwelling events responsible for the downward transport to the intermediate layer of the continental slope of biogeochemical components exported from the shelf in the upper layer. The shelf has been found to be an efficient trap for the refractory material discharged by the Danube.
The effectiveness of STEM-Based Science Teaching Materials in Improving elementary School Students’ Science Literacy

Science capability in Indonesia remains below expectations. Science mastery is limited to knowing the facts without being able to connect them to other, more complicated scientific concepts. Science exists to shape mindsets, behavior, and human character so that they can care for themselves, society, and the universe. In order to understand and solve problems, teaching materials that focus on life situations and global issues are required for implementation. The goal of this study was to assess the impact of STEM-based science teaching materials on students’ scientific literacy. This study employed a quantitative research design with a quasi-experimental research design. The Pretest-Posttest Control Group design was used. In this study, a test was used to measure students’ scientific literacy skills by having them answer pretest and posttest questions given to students in the control and experimental classes. Using STEM-based science teaching materials could increase scientific literacy of students with an N-gain score of 70.55 (high), but students who did not use STEM science teaching materials only had an N-gain score of 52.20 (medium). Based on data analysis, it was discovered that using STEM-based science teaching materials was very helpful in enhancing students’ scientific literacy.
Processes and mechanisms of persistent extreme precipitation events in East China

This study mainly presents recent progresses on persistent extreme precipitation events (PEPEs) in East China. A definition focusing both persistence and extremity of daily precipitation is firstly proposed. An identification method for quasi-stationary regional PEPEs is then designed. By utilizing the identified PEPEs in East China, typical circulation configurations from the lower to the upper troposphere are confirmed, followed by investigations of synoptic precursors for key components with lead time of 1-2 weeks. Two characteristic circulation patterns responsible for PEPEs in East China are identified: a double blocking high type and a single blocking high type. They may account for occurrence of nearly 80% PEPEs during last 60 years. For double blocking high type, about two weeks prior to PEPEs, two blockings developed and progressed towards the Ural Mountains and the Sea of Okhotsk, respectively. A northwestward progressive anomalous anticyclone conveying abundant moisture and eastward-extended South Asia High favoring divergence can be detected about one week in advance. A dominant summertime teleconnection over East Asia, East Asia/ Pacific (EAP) pattern, is deemed as another typical regime inducing PEPEs in the East China. Key elements of the EAP pattern initiated westward movement since one week prior to PEPEs. Eastward energy dispersion and poleward energy dispersion contributed to early development and subsequent maintenance of this teleconnection pattern, respectively. These typical circulation patterns and significant precursors may offer local forecasters some useful clues in identifying and predicting such high-impact precipitation events about 1-2 weeks in advance.
Analysis of Aloe vera Nano Powder (Aloe vera L.) using X-Ray Diffraction (XRD)

Aloe vera gel is considered necessary for further processing into high-value products like nano powder due to its complex but easily damaged nutrients. Aloe vera nanopowder is one solution to increase the properties and resistance of Aloe vera so that it can be used for nanotechnology applications, such as thin coatings. In this study, natural gel Aloe vera was converted into Aloe vera powder by adding a concentration of 0.3% Tween 80 and 15% maltodextrin. This method is called the Foam-mat drying method. Using High Energy Milling (HEM-E3D), the powder was mashed for five hours to achieve nanoscale size. The phase of the aloe vera nanopowder was determined by XRD analysis. The peaks 20, which were at an angle of 20°, indicated that the production of the Aloe vera nanopowder was successful. The angle of 20° showed the angle for organic materials and Aloe vera nanopowder is ready to be applied for the fabrication of hydrophobic materials.
Local scouring due to turbulent water jets downstream of a trapezoidal drop: Laboratory experiments and stability analysis

Three series of laboratory experiments were run, varying the flume water discharge and the downstream water depth, to investigate local scouring downstream of a trapezoidal drop followed by a rigid apron. Three different kinds of jets, developing downstream of the drop, were observed: a submerged jet, a surface wave jet, and an oscillating jet. The oscillating jet is defined as a jet which changes intermittently between a surface wave jet and a submerged jet. A different development of the scouring process due to the different kinds of jet was observed: a submerged jet produced a local scouring with a downstream dune, while a surface wave jet produced a local scouring with both an upstream and a downstream dune; the scouring process due to the oscillating jet was the result of the interaction of the scouring processes due to a submerged jet and a surface wave jet. A stability analysis of the surface wave jet was performed, with both a flat and a scoured bed, by means of the modified De Saint–Venant equations, that is, with correction terms accounting for the curvature of the streamlines. The stability of the surface wave jet is affected by the presence of the scoured bed, which weakens its stability properties.
Modeling 3D Supercritical Flow with Extended Shallow-Water Approach

Despite the three-dimensional (3D) nature of the flow, the classical shallow-water equations are often used to simulate supercritical flow in channel transitions. A closer comparison with experimental data, however, often shows large discrepancies in the height and pattern of the shock waves that increase with the Froude number. An extension to the classical shallow-water approach is derived considering higher-order distribution functions for pressure and horizontal and vertical velocities, therefore taking nonhydrostatic pressure distribution and vertical momentum into account. The approach is applied to highly supercritical flow in a channel contraction ( F0 =4.0) , a channel junction ( F0 ≈4.5 for both branches), and a channel expansion ( F0 =8.0) . Specific problems of such flows—wetting and drying of computational cells and wave breaking due to steep free-surface gradients—are discussed and solved numerically. The solutions with the extended approach are compared both with experimental data and class.
Latest Danian carbon isotope anomaly and associated environmental change in the southern Tethys (Nile Basin, Egypt)

Abstract: During the Palaeocene and Eocene Epochs (65.5–33.9 Ma) the Earth experienced the warmest conditions of the Cenozoic. This Palaeogene greenhouse episode is characterized by several short-lived negative carbon isotope (δ13C) excursions, which are usually interpreted as transient warming events (‘hyperthermals') as indicated by rising temperatures of surface and bottom waters, and accompanied carbonate dissolution in deep-sea settings. Among these events, the Palaeocene–Eocene Thermal Maximum (PETM, c. 55.5 Ma) is globally the best documented and most prominent. Further negative δ13C anomalies have recently been identified in the Eocene, but the early to middle Palaeocene has mostly been neglected. Here, benthic foraminiferal δ13C records are presented from four upper Danian–lower Selandian sections in the Nile Basin (eastern Egypt). All records show a negative δ13C shift with an amplitude of up to 2‰ at the base of planktonic foraminiferal subzone P3b (c. 61 Ma). The supra-regional nature of this event is emphasized by correlation with a well-dated, similar δ13C record from Zumaia (Spain). Lithological changes, the δ13C signature and biotic responses strongly resemble those of the PETM in Egypt, which leads to the hypothesis that this ‘Latest Danian Event' (LDE) may represent another early Palaeocene hyperthermal.
The 26.5 ka Oruanui eruption, New Zealand: A review of the roles of volcanism and climate in the post‐eruptive sedimentary response

Abstract The landscape response to large explosive pyroclastic volcanic eruptions is one of the most dramatic processes in sedimentology and geomorphology. Processes of post‐eruptive erosion and resedimentation are maximised by large erupted volumes, abundant unconsolidated ash‐sized material, destruction of the vegetation cover (particularly by burial by ignimbrite), and inhibition of vegetation regrowth (e.g., by harsh climatic conditions). The 26.5 ka Oruanui eruption from Taupo volcano in the central North Island of New Zealand created optimal conditions for a large‐scale sedimentary response that was influenced and prolonged by the succeeding climatic nadir of the Last Glacial Maximum. About 530 km3 of rhyolitic magma was erupted as 420 km3 of fall deposits, 320 km3 of pyroclastic density current deposits (mostly non‐welded ignimbrite), and 430 km3 of primary intracaldera fill. The eruption, and formation of the Oruanui caldera, destroyed one major lake but created the forerunner to modern Lake Taupo. This lake initially stably overflowed to the northwest before breaking out in a catastrophic flood during establishment of a northeasterly outlet along the line of the modern Waikato River. Suppression of revegetation by the contemporaneous harsh periglacial climate contributed to intense erosion and remobilisation of Oruanui pyroclastic units, triggering massive downstream fluvial aggradation in impacted catchments. In particular, aggradation caused the lower 180 km of the Waikato River to avulse from its long‐established route via the Hauraki Plains into the Hamilton Basin where it was subsequently trapped. Aeolian reworking created localised dune fields, while generation of tephric loess formed deposits over much of the central North Island. The initial perturbation to fluvial sedimentary systems created by the eruption was generally sustained by climatic conditions until c. 17 ka. Climatic amelioration eventually stabilised primary sediment sources through the re‐establishment of forest vegetation, but incision and recycling of alluvial material stored in volcaniclastic fans continued until as late as c. 14 ka. Overall, the scale of the post‐Oruanui sedimentary response was primarily driven by characteristics of the eruption, whereas its duration was controlled by the Last Glacial Maximum climate.
Surface Water Quality Assessment of Wular Lake, A Ramsar Site in Kashmir Himalaya, Using Discriminant Analysis and WQI

Multivariate techniques, discriminant analysis, and WQI were applied to analyze a water quality data set including 27 parameters at 5 sites of the Lake Wular in Kashmir Himalaya from 2011 to 2013 to investigate spatiotemporal variations and identify potential pollution sources. Spatial and temporal variations in water quality parameters were evaluated through stepwise discriminant analysis (DA). The first spatial discriminant function (DF) accounted for 76.5% of the total spatial variance, and the second DF accounted for 19.1%. The mean values of water temperature, EC, total-N, K, and silicate showed a strong contribution to discriminate the five sampling sites. The mean concentration of NO2-N, total-N, and sulphate showed a strong contribution to discriminate the four sampling seasons and accounted for most of the expected seasonal variations. The order of major cations and anions was and respectively. The results of water quality index, employing thirteen core parameters vital for drinking water purposes, showed values of 49.2, 46.5, 47.3, 40.6, and 37.1 for sites I, II, III, IV, and V, respectively. These index values reflect that the water of lake is in good condition for different purposes but increased values alarm us about future repercussions.
GPS-derived coupling estimates for the Central America subduction zone and volcanic arc faults: El Salvador, Honduras and Nicaragua

SUMMARY We invert GPS velocities from 32 sites in El Salvador, Honduras and Nicaragua to estimate the rate of long-term forearc motion and distributions of interseismic coupling across the Middle America subduction zone offshore from these countries and faults in the Salvadoran and Nicaraguan volcanic arcs. A 3-D finite element model is used to approximate the geometries of the subduction interface and strike-slip faults in the volcanic arc and determine the elastic response to coupling across these faults. The GPS velocities are best fit by a model in which the forearc moves 14–16 mm yr −1 and has coupling of 85–100 per cent across faults in the volcanic arc, in agreement with the high level of historic and recent earthquake activity in the volcanic arc. Our velocity inversion indicates that coupling across the potentially seismogenic areas of the subduction interface is remarkably weak, averaging no more than 3 per cent of the plate convergence rate and with only two poorly resolved patches where coupling might be higher along the 550-km-long segment we modelled. Our geodetic evidence for weak subduction coupling disagrees with a seismically derived coupling estimate of 60 ± 10 per cent from a published analysis of earthquake damage back to 1690, but agrees with three other seismologic studies that infer weak subduction coupling from 20th century earthquakes. Most large historical earthquakes offshore from El Salvador and western Nicaragua may therefore have been intraslab normal faulting events similar to the M w 7.3 1982 and M w 7.7 2001 earthquakes offshore from El Salvador. Alternatively, the degree of coupling might vary with time. The evidence for weak coupling indirectly supports a recently published hypothesis that much of the Middle American forearc is escaping to the west or northwest away from the Cocos Ridge collision zone in Costa Rica. Such a hypothesis is particularly attractive for El Salvador, where there is little or no convergence obliquity to drive the observed trench-parallel forearc motion.