Miracle-dz/UniFAR-FTUs huggingface dataset:
Modelling mid‐channel bars in meandering channels

An analytical modelling framework is proposed to reproduce the frequently observed but poorly studied occurrence of mid‐channel bars in meandering channels. Mid‐channel bars occur in meanders and may characterize transitional morphologies between pure meandering and braided rivers. Based on existing field and experimental observations, we propose that two different mechanisms can generate central topographical patterns in meanders. A former mechanism (‘width‐forced’) is related to spatial width oscillations which determine a laterally symmetrical bed shear stress pattern that promotes mid‐channel bars. A second mechanism (‘curvature‐forced’) can take place also in curvilinear equiwidth streams since also longitudinal variations of channel curvature can produce laterally symmetrical alterations of the sediment transport capacity. A perturbation approach is employed to model both mechanisms within a common framework, allowing reproduction, at least qualitatively, of several observed features. While width‐forced mid‐channel bars are a symmetric linear altimetric response, to reproduce curvature‐forced mid‐channel bars requires modelling nonlinear flow‐bed topography interactions at the second order of the perturbation expansion. Hypotheses on how these mechanisms operate are further discussed through an application to field cases. The amplitude of the nonlinear response can be relevant compared to that of the point bar in equiwidth meanders and the location of mid‐channel bars seldom coincides with bend apexes, mainly depending upon the intrinsic meander wavelength. Central bars tend to symmetrically divert the flow against the two banks, a process which is proposed as a possible cause of cross‐sectional overwidening, along with the asymmetry between the rates of bank erosion and of the opposite bank accretion. The outcomes of this first modelling step on the subject allow discussion of the mutual feedback processes that characterize interactions between mid‐channel bars and width variations in river meanders. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of acute exercise on objectively measured sleep and cognition in older adults

Background Exercise can improve cognition in aging, however it is unclear how exercise influences cognition, and sleep may partially explain this association. The current study aimed to investigate whether objectively measured sleep mediates the effect of an acute exercise intervention on cognition in older adults. Methods Participants were 30 cognitively unimpaired, physically active older adults (69.2 ± 4.3 years) with poor sleep (determined via self-report). After a triple baseline cognitive assessment to account for any natural fluctuation in cognitive performance, participants completed either a single bout of 20-minutes of high intensity exercise on a cycle ergometer, or a control condition, in a cross-over trial design. Cognition was measured immediately post-intervention and the following day, and sleep (total sleep time, sleep onset latency, sleep efficiency, % of rapid eye movement sleep, light sleep and deep sleep) was characterized using WatchPAT™ at baseline (5 nights) and measured for one night after both exercise and control conditions. Results Results showed no effect of the exercise intervention on cognition immediately post-intervention, nor an effect of acute exercise on any sleep variable. There was no mediating effect of sleep on associations between exercise and cognition. However, a change from baseline to post-intervention in light sleep and deep sleep did predict change in episodic memory at the ~24 h post-intervention cognitive assessment, regardless of intervention condition. Discussion There was no effect of acute high intensity exercise on sleep or cognition in the current study. However, results suggest that associations between sleep and cognition may exist independently of exercise in our sample. Further research is required, and such studies may aid in informing the most effective lifestyle interventions for cognitive health.
Review on Microfluidic Technology Based Synthesis of Fe-based Nanoparticles for Catalyst in Fuel Cell

Conventional combustion based energy generations, reliant on fossil fuels, poses significant environmental harm. In contrast, fuel cells offer an efficient and eco-friendly energy conversion method, capable of integrating with renewable sources and contemporary energy carriers to support sustainable development and energy security. Consequently, fuel cells are considered the promising energy conversion devices of the future. However, extensive research reveals that the cost of catalysts constitutes the most substantial portion of the overall fuel cell cost. To tackle this cost constraint, considerable advancements have been achieved in the development of cost-effective, precious metal-free electrocatalysts. Common methods for the preparation of metal nanomaterials (NPs) have more stringent requirements, lower deposition efficiency and higher costs. In addition, conventional preparation methods without precisely control of reagent concentration, mixing and temperature during the preparation process, makes it difficult to obtain the same results with poor reproducibility, restricting the industrial fabrication of high performance nanomaterials. Microfluidic reactors have advantages of efficient mixing, high heat and mass transfer, low reagent consumption, precise control of reactant components, residence time, reaction temperature and other parameters. They can also be coupled with multi-step reactions, greatly reducing the preparation time while obtaining composite nanomaterials with excellent dimensional homogeneity. In this review, we mainly discuss the microfluidic technology-based synthesis of PGM-free catalyst used in fuel cell.
In situ creep of frozen soil, Fenghuo Shan, Tibet Plateau, China

Field measurements of frozen soil creep in the upper 3.0 m of permafrost indicate that creep occurs in both winter and summer. Between 1992 and 1993, the mean rate of creep ranged from 0.44 cm at 1.6 m depth to 0.16 cm at 2.8 m depth but there was extreme variability. Creep parameters n and A, as defined by the power flow law, were calculated from field data. Parameter n ranged between 1.96 and 2.29 and increased with depth, while A decreased with depth. Comparisons of creep rates for different permafrost environments suggest that ground temperature largely controls the magnitude of permafrost creep. Key words : permafrost, creep parameters, Tibet Plateau.
Properties and dimensional stability of 12 500-year-old subfossil pine wood

At the Koźmin Las site, in Central Poland, in the middle section of the Warta River valley, a series of well-preserved tree trunks and in situ stumps, as well as organic deposits, have been found. The tree remains are dated back to the period between 13,000–12,600 cal BP, i.e. to the Alleröd/Younger Dryas transition. The forest consisted predominantly of pines (Pinus sylvestris L.) of a maximum age of approx. 140 years and an average age of 68 years, and the river valley floor was overgrown. The forest was destroyed ca. 12,600 cal BP by deteriorating hydrological conditions or a sudden catastrophic event. The aim of the study was to assess the degree of degradation in terms of selected macroscopic, physical and chemical properties of a subfossil pine log. On this basis, a conservation process was developed, using aqueous solutions of polyethylene glycols (PEG) with varying concentrations of low- and high-molecular polymers. Treated and dried samples were compared in terms of their tangential and radial dimensional stability, as well as their hygroscopic properties.
Development of a predictive analytical cutting force and torque model for flat bottom drilling of metals using mechanistic approach

Abstract By far a large scale of industrial components is being manufactured from metallic materials. Most of these components possess holes in order to fulfill design and application requirements, such as assembly of screws, pins or passing channels for fluids. Depending on the utilized manufacturing method and positioning of these components during machining processes, these holes are being drilled even in vertical or inclined orientations with respect to the jig and fixturing systems. In vertical drilling of the flat surfaces conventional or indexable inserted drill are the commonly used tools. However, these types of tools do not demonstrate sufficient performance on the surfaces drilled holes due to the occurred run-out, vibrations when being used in inclined features. Therefore, flat bottom drills have been developed in order to be used for curved or inclined surfaces. Thus, optimization of the tool and components design requires a deeper knowledge on the cutting forces and torques when using flat bottom drills. In this study, a predictive analytical cutting force model is developed for flat bottom drills for both vertical and inclined plunging using mechanistic approach in Matlab. The model is established on the distributed elementally cutting along the tool radius considering both rake and relief faces based upon the orthogonal and oblique cut principles. Accordingly, the performance of the developed model for different cutting tools with various geometries and machining parameters have been evaluated and verified with experimental results of flat bottom drilling of brass alloy.
Computation of Slope Movements Initiated by Rain–Induced Shear Bands in Small–Scale Tests and In Situ

Computational investigations of the complex flow and deformation processes of natural slopes within a continuum‐mechanical approach become more and more important due to an increasing number of slope movements and slope failure situations caused by heavy rainfall events. Numerical simulations of hillslopes can support the detection of various coupled failure mechanisms by simply changing the initial and boundary conditions of the considered initial‐boundary‐value problem. This procedure can contribute to a deeper and better understanding of various complex slope failure processes. In this study, the slope system, generally understood as an unsaturated soil, was considered as a triphasic material consisting of a soil skeleton, such as sand, a pore liquid, such as water, and a pore gas, such as air. The model was embedded in the well‐founded theory of porous media, while numerical solutions were realized by use of the finite‐element solver PANDAS. Proceeding from cohesionless sand as the basic soil under study, the material parameters governing the soil behavior were taken from triaxial experiments on dry sand specimens performed under homogeneous loading conditions, whereas the parameters governing the hydraulic behavior were determined by experiments on saturated soil specimens under nondeforming conditions. Furthermore, numerical investigations of slope failure scenarios under different loading conditions were compared with each other to find out how the pore water influences the failure behavior. The computations reveal a strong coupling between the soil deformation and the hydraulic behavior during failure processes. Finally, the flow and deformation behavior of the natural Heumoes slope in Ebnit situated near Dornbirn in the eastern part of the Voralberg Alps (Austria) was studied qualitatively. Unfortunately, this slope is still in motion.
Osmian Hollingworthite and Rhodian Cobaltitegersdorffite from the Lukkulaisvaara Layered Intrusion, Russian Karelia

H o i.lincjworthith, ideally RhAsS, was first described by Stumpfl and Clark (1965) from the Bushveld igneous complex. Since then it has been reported from the same and other occurrences in the Bushveld (Gcnkin et aL, 1966; Stumpfl, 1972; Tarkian and Stumpfl, 1975); Werner Lake, Canada (Rucklidgc, 1969); Hitura (Hakli et al., 1976), Penikat (Alapieti and Lahtinen, 1986; Halkoaho et a l.y 1990; Halkoaho, 1994), Siikakama (Hiinninen et a i , 1986), Finland; placers from the Urals (Bcgizov et at., 1976), a m afic-u ltram afic complex. Kola Peninsula (D istler and Laputina, 1981), Cu-Ni su lph ide deposits o f N o r i ls k (G enk in and Evstigneeva. 1986) and alpine-type complexes, Russia (D istler et al., 1986); Stillwater layered complex (Volborth et a i, 1986); Shetland ophiolites (Tarkian and Prichard, 1987; Prichard and Tarkian, 1988); Osthammcrcn, Norway (Nilsson, 1990); Two Duck Lake, Canada (Ohncnstcttcr et aL, 1991); Lukkulaisvaara, Mt. Gencralskaya and Imandrovsky layered intrusions, NW Russia (Barkov and Lcdnev, 1993; Barkov et a l.t 1994; 1995^? ), although in only a few cases are Os-rich hollingworthites recorded (Stumpll, 1972; Distler and Laputina, 1981; Tarkian and Prichard. 1987; Ohnenstetter el a i, 1991). Hollingworthite is a cuhic mineral with a cobaltitetype structure, isostructural with two other platinumDepartment o f Geosciences and Astronomy, University o f Oulu, FIN-90570 Oulu, Finland
Outbreak of nosocomial sepsis in NICU by multidrug-resistant Klebsiella pneumoniae: Diagnostic challenges

Purpose: Nosocomial infections are a serious problem in neonatal intensive care units (NICU) – they are one of the main causes of morbidity and mortality among preterm newborns. Material/methods: We present a prospective clinical-epidemiological study of an outbreak of 7 cases of culture-proven multidrug-resistant (MDR) Klebsiella pneumoniae late onset sepsis in a period of 2 months in a tertiary level NICU in Pleven, Bulgaria. The risk factors, early clinical presentation, laboratory changes, course of infection, treatment, and outcome were evaluated. Results: Three of our patients were term infants, the other four patients were preterm aged from 25 to 36 gestational weeks. The most possible routs of transmission of the infection were: venous lines, mechanical ventilation, tube feeding. Аll of the mentioned were present in one extremely immature patient. Early clinical signs included skin color changes, abnormal muscle tone, respiratory failure. Laboratory tests taken at the time of onset revealed leucopenia and/or thrombocytopenia in a half of the cases and usually C-reactive protein remained normal, but in all cases the I/T ratio increased significantly. The clinical course varied from fulminant deterioration to easily controlled condition. Treatment with Meropenem was started at the time of clinical suspicion of infection, according to the antibiogram of the first cases. No fatal outcome was observed. Conclusion: Main causes for the outbreak of hospital acquired infection were overcrowding of the NICU, admission of patients from lower-level hospitals, insufficient working staff, especially midwifes. The early diagnosis and proper antimicrobial treatment were crucial for the favorable outcome.
Physical and Chemical Components of Cuba’s Rain: Effects on Air Quality

The objective of this study was to analyze the influence of the physical and chemical components of rain affecting air quality in Cuba. Samples were obtained from pollution monitoring stations throughout Cuba. Different chemical analyses including elements and ions were conducted. Meteorological data was also included for the analysis. Results show that the pH was slightly basic for most stations, except those of the eastern region which exhibit pH values below 5.6. The major anthropogenic sources of ions are the burning of fossil fuel by power plants, cement factories, and nickel-processing industries and the burning of biomass through poor agricultural practices. The western region exhibited increased concentrations of and during the dry season, most likely due to the long-range transport of pollutants from the northeastern United States as well as local pollutants. Marine aerosols clearly influence Cuba’s rain. Only a small fraction of the potentially acidic ions contributes to the free acidity of Cuba’s rainwater, mainly due to the neutralizing capacity of some ions such as Cl-, Na
Learning-Based Fault-Tolerant Control for an Hexarotor With Model Uncertainty

In this brief, we present a learning-based tracking controller based on Gaussian processes (GPs) for a fault-tolerant hexarotor in a recovery maneuver. In particular, we use GPs to estimate certain uncertainties that appear in a hexacopter vehicle with the ability to reconfigure its rotors to compensate for failures. The rotor’s reconfiguration introduces disturbances that make the dynamic model of the vehicle differ from the nominal model. The control algorithm is designed to learn and compensate for the amount of modeling uncertainties after a failure in the control allocation reconfiguration by using GP as a learning-based model for the predictions. In particular, the presented approach guarantees a probabilistic bounded tracking error with high probability. The performance of the learning-based fault-tolerant controller is evaluated by experimental tests with a hexarotor unmanned aerial vehicle (UAV).
Estimation of the building damages in Yushu earthquake based on ALOS SAR data

On April 14th, 2010, a large earthquake (Ms=7.1) shocked the Yushu county in the Qinghai Province at western China. It caused severe damages and fatalities. The purpose of this paper is to estimate the building damages caused by the earthquake based on pre and post earthquake ALOS SAR data. The distribution of the buildings in the Yushu city was extracted from the intensity images of the SAR data. Phase coherence between two scenes of SAR data were calculated to assess the building damages. The results show that the buildings close to the surface rupture caused by the earthquake are broken severely. The further to the surface rupture, the less damages of the buildings. It indicates that avoiding the potential rupture zone in the urban planning is necessary to mitigate the earthquake hazards.
Philosophy of worldview as a basis for world perception and socio-cultural traditions

In the era of globalisation's transformation of socio-cultural standards, the worldview philosophy serves as the basis for their revision and implementation of appropriate changes. Particularly, the requirement to ensure the norms of cultural diversity restores the need to refer to a worldview category in the scientific and public discourse. The research goal of this article is to provide an appropriate justification of the philosophy of worldview as the basis of world perception and socio-cultural traditions. Namely, the paper addresses the following questions: (1) What is the broader context for the Eastern European levelled description model of worldview? (2) Is the explanation of the world perception as a subset of worldview relevant? (3) What are the conjunctures of socio-cultural tradition and world perception at the level of worldview? (4) Is the tradition change possible as a result of changing the sum of the worldviews of actors? The methodology is based on an iterative progression of analytical and synthetic methods. The review of publications served as basis for testing the theoretical model to encapsulate the interaction between the actor and the cultural context. The results organise the connectors between the worldview and world perception in the socio-cultural dimension. The level model of worldview needs to be revised and empirically tested, but it provides auxiliary constructs for the operationalisation. The changes in worldview that are implemented at different levels have a different normative value. Implications of the presented research are contained in the dimension of cultural hybridization, which leads to the formation of new worldview schemes, and socially desirable outcomes, through changes in the world perception of actors. The spread of the Eastern European level model will contribute to a shift away from the Western-centred methodology and will also provide the necessary tools for a revision of traditional practices.
A Field Course in Tropical Coastal Geology

ABSTRACT Coch, N. K. , 2013. A field course in tropical coastal geology. South Florida, United States, is an ideal place for conveniently studying modern carbonate environments and their fossil equivalents in close proximity. It is the only place where such field studies can be carried out with the excellent logistical support available in a major metropolitan area (Miami). Consequently, south Florida has been used extensively for training petroleum geologists as well as providing reef and quarry trips of short duration for geology classes. However, south Florida can also be used to study geomorphic features; biogenic and clastic sedimentology in fresh, brackish, and saline environments; and stratigraphic studies which correlate widely-spaced rock outcrops. In addition, many aspects of environmental geology, including groundwater, water pollution, ecological changes accompanying development, and the effects of hurricanes, can be studied here. This holistic approach was used in a 3 week laboratory and field course first offered in the summer of 1985. The area has been visited several times since then, and the places and features described in this paper are accurate as of February 2012. A uniformitarian approach was used, in which students studied rock outcrops and then examined the present-day depositional equivalent of each facies by snorkeling over modern reef tracts in the Florida Keys. Outcrops of Pleistocene rock units were examined from Miami southward through the Florida Keys. Students utilized the outcrop data, along with published data and their own observations of reef complexes, to make a regional stratigraphic synthesis and paleogeographic reconstruction for the study area. This article describes the course structure, field exercises, and logistics, which can serve as the basis for similar courses or site visits in this area in the future. Additional information is provided so instructors can tailor the course around their available time and financial limitations, anywhere from 3 days to 3 weeks.
Lane-Change Trajectory Planning and Control Based on Stability Region for Distributed Drive Electric Vehicle

Motion control of lane-change maneuvers under high-speed scenarios creates a great challenge for autonomous vehicles. However, a novel framework of lane-change trajectory planning and control based on the dynamic characteristics of distributed drive electric vehicles (DDEVs) is proposed in this paper to increase the possibility of safe driving in complex traffic conditions. First, a dilatational stability region determined by limits of stable yaw rate and saturated slip angles of each tire is employed to reveal dynamic instantaneous characteristics. On the basis of dilatational stability regions, the expanded envelopes by additional direct yaw moment can be identified by the expressions of irregular hexagons. Then, a series of unconstrained lane-change trajectory clusters can be generated to minimize longitudinal and lateral jerk, which is used to divide the global feasible region determined by the dilatational stability region and three-dimensional collision-free tunnel. Then, the technique for order preference for similarity to the ideal solution (TOPSIS) is utilized to achieve optimization of trajectory candidates from the global feasible region. The tracking controller aims at following the optimal lane-change trajectory, which is designed by the expanded stability boundaries of DDEV. Finally, simulations and experiments are conducted to validate the performance of the proposed planner and controller under high-speed, full-road and multi-vehicle traffic conditions.