Miracle-dz/UniFAR-FTUs huggingface dataset:
Mechanical energy balance and apparent fracture toughness for dykes in elastoplastic host rock with large-scale yielding

The dynamics of dyke emplacement are typically modelled by assuming an elastic rheology for the host rock. However, the resulting stress field predicts significant shear failure in the region surrounding the dyke tip. Here, we model the dyking process in an elastic-perfectly plastic host rock in order to simulate distributed shear fracturing and subsequent frictional slip on the fracture surfaces. The fluid mechanical aspects of the magma are neglected as we are interested only in the fracture mechanics of the process. Magma overpressure in dykes is typically of the same order of magnitude as the yield stress of the host rock in shear, especially when the pressure effect of volatiles exsolving from the magma is taken into account. Under these conditions, the plastic deformation zone has spatial dimensions that approach the length of the dyke itself, and concepts based on linear elastic fracture mechanics (LEFM) no longer apply. As incremental plasticity is path dependent, we describe two geologically meaningful endmember cases, namely dyke propagation at constant driving pressure, and gradual inflation of a pre-existing crack. For both models, we find that plastic deformation surrounding the fracture tip enhances dyke opening, and thus increases the energy input into the system due to pressure work integrated over the fracture wall. At the same time, energy is dissipated by plastic deformation. Dissipation in the propagation model is greater by about an order of magnitude than it is in the inflation model because the propagating dyke tip leaves behind it a broad halo of deformation due to plastic bending and unbending in the relict process zone. The net effect is that plastic deformation impedes dyke growth in the propagation model, while it enhances dyke growth in the inflation model. The results show that, when the plastic failure zone is large, a single parameter such as fracture toughness is unable to capture the physics that underpin the resistance of a fracture or dyke against propagation. In these cases, plastic failure has to be modelled explicitly for the given conditions. We provide analytical approximations for the propagation forces and the maximum dyke aperture for the two endmember cases, that is, the propagating dyke and the dyke formed by inflation of a crack. Furthermore, we show that the effect of plasticity on dyke energetics, together with an overestimate of magma pressure when interpreting dyke aspect ratios using elastic host rock models, offers a possible explanation for the long-standing paradox that laboratory measurements of fracture toughness of rocks consistently indicate values about two orders of magnitude lower than those derived from dyke observations.
Community College Student Success Among Non-Completers: A Narrative Exploration of The Phenomenon of Positive Attrition Through The Voices of California Community College CTE Students

This qualitative research study investigated the motivations and perceptions of community college career and technical education students related to their reasons for leaving programs prior to CTE certificate or course completion utilizing narrative inquiry. Former students were asked about their background, education and employment goals, college and community environment influences in relation to their community college experience and their definition of student success. Data collection methods included identifying and interviewing ten former CTE students from two college campuses who had previously participated in a survey of CTE completers and leavers piloted at fourteen community colleges in California. Narrative data revealed that although students may not complete a CTE certificate or degree, they categorize their experiences as successful for advancing them on both career and academic pathways, indicating a need for expanded definitions of student success for community college CTE students.
Analýza a modelování změn kvality vody v povodí Olšavy

Klíčové kapitoly práce představují oddíly 3 5, ve kterých je podrobně popsána aplikace modelu MIKE Basin na povodí Olšavy, vlastní dosažené výsledky a jejich diskuse. Pro vlastní simulaci autorka vychází ze dvou scénářů možného vývoje jakosti vody. Scénáře byly definovány tak, aby byly ekonomicky realizovatelné relevantnost navržených opatření v rámci scénářů při zpracování práce navíc konzultovala s vodohospodářskými odborníky.
Diet partitioning and trophic guild structure of fish assemblages in Chishui River, the last undammed tributary of the upper Yangtze River, China

Knowledge of trophic ecology of fish species is fundamental to understand the organization mechanism of fish assemblages and crucial for developing effective management and conservation strategies. This study examined the diet partitioning and trophic guild structure of fish assemblages in Chishui River, the last undammed tributary of the upper Yangtze River, China. Specimens were collected in three sections along the upstream–downstream gradient in 2012. Digestive tract contents of 54 fish species, represented by 692 individuals, were analysed and quantified. Analysis showed that fish assemblages in the Chishui River utilized aquatic insects, algae, detritus, molluscs, and fishes as the main food resources, whereas terrestrial insects were consumed only occasionally. The trophic guild structure of fish assemblages changed gradually with the longitudinal gradient. Specially, the number of trophic guilds increased with downstream distance. In addition, the relative number of omnivorous species increased longitudinally, whereas the relative number of insectivorous species declined downstream. This study demonstrated how fish assemblages utilize the food resources under near‐natural conditions. These results provide valuable information for fish conservation and ecological restoration.
Development of a Non-Parametric Stationary Synthetic Rainfall Generator for Use in Hourly Water Resource Simulations

This paper presents a new non-parametric, synthetic rainfall generator for use in hourly water resource simulations. Historic continuous precipitation time series are discretized into sequences of dry and wet events separated by an inter-event dry period at least equal to four hours. A first-order Markov Chain model is then used to generate synthetic sequences of alternating wet and dry events. Sequential events in the synthetic series are selected based on couplings of historic wet and dry events, using nearest neighbor and moving window methods. The new generator is used to generate synthetic sequences of rainfall for New York (NY), Syracuse (NY), and Miami (FL) using over 50 years of observations. Monthly precipitation differences (e.g., seasonality) are well represented in the synthetic series generated for all three cities. The synthetic New York results are also shown to reproduce realistic event sequences proved by a deep event-based analysis.
Soil Fluid Biogeochemical Response to Climatic Events

Predicting fluid biogeochemistry in the vadose zone is difficult because of time‐dependent variation in multiple controlling factors, such as temperature, moisture, and biological activity. Furthermore, soils are multicomponent, heterogeneous porous media where manifold reactions may be affecting solution chemistry. We postulated that ecosystem‐scale processes, such as carbon fixation and ecohydrologic partitioning, control subsurface biogeochemical reactions, including mineral weathering. To test this hypothesis, we applied a novel “instrumented pedon” research approach. Analysis of the data streams demonstrates the interactions between pulsed wetting events and biogeochemical processes in the soil profile, and along groundwater flow paths. Rapid wetting front propagation into dry soil resulted in a pulsed increase in CO2 partial pressure in deeper soil layers, whereas wetting front propagation into a premoistened soil profile showed the opposite effect. The apparent respiratory quotient (ARQ), calculated from CO2 and O2 fluxes, deviated from expected oxidative ratios particularly during soil wetting events. These deviations were correlated in time with pore water geochemical responses, revealing that a fraction of the respired CO2 was consumed locally in pulsed silicate weathering events that accompanied wetting‐front propagation. However, most of this CO2 was dissolved in the soil pore water and transported downgradient, and along the soil‐bedrock interface, where a portion of it was further consumed in silicate weathering reactions, and another portion was degassed to the atmosphere. These results highlight the tight coupling that exists between physical, biological, and chemical processes, on event time scales, during incremental co‐evolution of the critical zone, particularly in water‐limited systems.
Evaluating k-Nearest Neighbor (kNN) Imputation Models for Species-Level Aboveground Forest Biomass Mapping in Northeast China

Quantifying spatially explicit or pixel-level aboveground forest biomass (AFB) across large regions is critical for measuring forest carbon sequestration capacity, assessing forest carbon balance, and revealing changes in the structure and function of forest ecosystems. When AFB is measured at the species level using widely available remote sensing data, regional changes in forest composition can readily be monitored. In this study, wall-to-wall maps of species-level AFB were generated for forests in Northeast China by integrating forest inventory data with Moderate Resolution Imaging Spectroradiometer (MODIS) images and environmental variables through applying the optimal k-nearest neighbor (kNN) imputation model. By comparing the prediction accuracy of 630 kNN models, we found that the models with random forest (RF) as the distance metric showed the highest accuracy. Compared to the use of single-month MODIS data for September, there was no appreciable improvement for the estimation accuracy of species-level AFB by using multi-month MODIS data. When k > 7, the accuracy improvement of the RF-based kNN models using the single MODIS predictors for September was essentially negligible. Therefore, the kNN model using the RF distance metric, single-month (September) MODIS predictors and k = 7 was the optimal model to impute the species-level AFB for entire Northeast China. Our imputation results showed that average AFB of all species over Northeast China was 101.98 Mg/ha around 2000. Among 17 widespread species, larch was most dominant, with the largest AFB (20.88 Mg/ha), followed by white birch (13.84 Mg/ha). Amur corktree and willow had low AFB (0.91 and 0.96 Mg/ha, respectively). Environmental variables (e.g., climate and topography) had strong relationships with species-level AFB. By integrating forest inventory data and remote sensing data with complete spatial coverage using the optimal kNN model, we successfully mapped the AFB distribution of the 17 tree species over Northeast China. We also evaluated the accuracy of AFB at different spatial scales. The AFB estimation accuracy significantly improved from stand level up to the ecotype level, indicating that the AFB maps generated from this study are more suitable to apply to forest ecosystem models (e.g., LINKAGES) which require species-level attributes at the ecotype scale.
The response of vegetation cover and dune activity to rainfall, drought and fire observed by multitemporal satellite imagery

The stable longitudinal dunes in the northern Simpson Desert, Australia, were observed in satellite imagery to become more active after vegetation cover was reduced by fire and drought. Subsequent rainfall events also resulted in significant vegetation regrowth and dune stabilization. These switches between more active and stable conditions have not been previously described in the largely vegetated dune fields of central Australia. The observations, made on 12 dune sites, relied on high spatial resolution satellite imagery to observe dune crest activity, and seasonal Landsat fractional cover imagery to observe vegetation cover changes. The non‐photosynthetic vegetation (NPV) component of the fractional vegetation cover images revealed significant changes in hummock grass cover on the dunes between 1988 and 2018, with a positive relationship with the three‐year cumulative rainfall, disrupted by two periods of patchy burning. Only those sites that had burnt became active, and only after vegetation cover had remained low (NPV < 16%) during the ‘Millennium Drought’. There is no threshold in vegetation cover, below which dune crests become active, but active dune features require four‐years of low NPV cover (< 16%) to develop. The large rainfall event that ended the drought increased NPV cover, stabilizing the dunes. Similar hummock grass covered dunes are present across large areas of the arid zone, and are likely to respond in similar ways, given that fire and drought are common occurrences in Australia. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.
Design of quasi-phase-matching nonlinear crystals based on quantum computing

Quasi-phase-matching (QPM) makes it possible to design domain engineered nonlinear crystals for highly efficient and multitasking nonlinear frequency conversion. However, finding the optimal crystal domain arrangement in a meaningful time is very challenging sometimes impossible by classical computing. In this paper, we proposed a quantum annealing computing method and used D-Wave superconducting quantum computer to design aperiodically poled lithium niobate (APPLN) for coupled third harmonic generation (CTHG). We converted the optical transformation efficiency function to an Ising model which can be solved by D-Wave quantum computer. The crystal design results were simulated by using nonlinear envelope equation (NEE), which showed very similar conversion efficiencies to the crystals designed by using simulated annealing (SA) method, demonstrating that quantum annealing computing is a powerful method for QPM crystal design.
Prediction of squat of ships sailing in restricted water

There are several methods for the determination of sinkage and trim of ships sailing in restricted water described ín literature. Two main categories can be distinguished: methods which enable the designer to calculate the waterlevel depression and methods by which the sinkage can be ca'culated. In the former category it is normally assumed that water-level depression and sinkage are equal. In this paper the results of 12 methods are compared with the resuits of model investigations. Conclusions are given concerning the methods which can best be used to calculate sinkage, trim and water-level depression with respect to the channel width! ship's beam ratio.
The impact of rural community-based diabetes screenings to motivate clients to action.

Context: Community-based screenings have demonstrated moderate success for early detection and prevention of a variety of disease states in selected populations. However, few studies have illustrated the benefits of community-based screenings in rural populations for their ability to motivate participants to improve health behaviors. Purpose: Community-based diabetes screenings were conducted on two occasions in a rural community with a high prevalence of diabetes-related medical complications. Study participants were surveyed 3-months post-screening to determine the impact of the screening as motivation to change behaviors known to influence diabetes risk; and for those with diabetes, to motivate changes in self-management behaviors. Methods: Screening data was used to classify participants by diabetes status (current diagnosis of diabetes, no diagnosis but at risk, or no diagnosis and not at risk). Participants completed a health behavior assessment at the screening and 3 months following the screen. Data from the follow-up survey was used to determine self-reported behavior changes that participants attributed to the screening. Findings: Fifty-four of 78 participants who were screened returned follow-up surveys for a response rate of 69%. Over half of the respondents (56%) were motivated by the screening to exercise more, while 82% were motivated to watch their dietary intake. Of respondents with diabetes, 80% were motivated to exercise more, 100% were motivated to watch their dietary intake, 75% were motivated to check blood glucose levels more frequently, and 67% were motivated to take medications on time. Conclusion: Rural community-based screenings for diabetes can be an effective intervention to motivate health behavior change in individuals with and without diabetes.
Power Flow Control In Hybrid Ac/Dc Microgrids

Microgrid structures allow for more efficient utilization of renewable resources as well as autonomous operation. Ideally, a centralized controller would be available to allow for an optimizer to take all components into account so that they may collaboratively work towards a shared goal. To this end, a centralized optimization method was developed called the squared slack interior point method. The novelty of this method is that it incorporates the fraction to bound rule to alleviate the known ill-conditioning introduced by utilizing squared slack variables to handle inequality constraints. In addition, this method also allows for inequality constraint violations to be quantified in the same manner that equality constraints are quantified. The proposed method is found to quickly and accurately calculate the optimal power flow and reject solutions that violate the inequality constraints beyond some specified tolerance. Where centralized information is not available, a decentralized method is required. In this method, constrained game theoretical optimization is utilized. However, due to unknown information about remote loads, inconsistent solution among players result in overloaded generators. To alleviate this issue, two perturbation methods are introduced. The first is overload feedback and the second is the perturb and observe squeeze method. In both methods, the goal is to adjust voltage angles and magnitudes to locally manage generator output. Both methods are found to rapidly drive overloaded sources back within their desired tolerances. Moreover, the game theoretical approach is found to have poor performance in the absence of shared load information among players. It is determined that the localized optimizers should be removed to reduce cost and that the operating condition should be perturb starting from the most recently available power flow calculation or starting from the nominal value. Also, to manage voltage stability in the absence of communication, a Hamiltonian approach is implemented for the voltage source rectifier. This approach resulted in a highly stable voltage and
Delta and jagged are candidate target genes of RNAi biopesticides for the control of Nilaparvata lugens

The brown planthopper (BPH; Nilaparvata lugens) is an important pest in rice cultivation, and chemical pesticide over-use and ineffectiveness of existing Bt transgenic rice against piercing-sucking insects make novel control methods necessary. RNA interference (RNAi) biopesticide is a new type of product with high efficiency and specificity and are simple to use. The Notch signaling pathway has extensive and important physiological functions and plays a key role in the development of insects. In this study, two key ligand genes of the Notch signaling pathway, delta (dl) and jagged (jag), were selected and their lethal effects and functional analysis were systematically evaluated using a stable short-winged population (Brachypterous strain) and a long-winged population (Macropterous strain) of BPHs. The full-length coding sequences of Nldl and Nljag comprised 1,863 and 3,837 base pairs, encoding 620 and 1,278 amino acids, respectively. The nucleic acid sequences of Nldl and Nljag were identical between the two strains. The expression levels of Nldl and Nljag were relatively high in the head of the nymphs, followed by those in the abdomen. Through RNAi treatment, we found that injection of BPH nymphs of both strains with dsNldl (10–50 ng/nymph) or dsNljag (100 ng/nymph) produced lethal or teratogenic effects. dsRNA treatment showed excellent inhibitory effects on the expression of target genes on days 1 and 5, suggesting that RNAi rapidly exhibits effects which persist for long periods of time in BPHs. Taken together, our results confirm the potential of Nldl and Nljag as target genes of RNAi biopesticides, and we propose optimized dosages for the control of BPHs.
3D Elastic FWI for Land Seismic Data: A Graph Space OT Approach

Integrating surface wave information is challenging for land seismic full waveform inversion (FWI). Cycle-skipping of surface waves can easily occur due to their highly dispersive and oscillating properties. While this issue can be mitigated using wider basin objective functions, a more severe difficulty is related to the unbalanced amplitude distribution between surface waves and body waves. The energetic surface waves dominate the objective function and drive the inversion to update only the shallow structure. The contribution from body waves is masked and the deep structures are not recovered. In a recent study, we have shown how an optimal-transport based misfit function can help mitigating this issue, providing naturally a better balance between events (KR-OT approach). Here, we apply a newly introduced OT based misfit function, relying on a graph space approach (GS-OT), in this framework of elastic FWI for land data. GS-OT better handles cycle skipping than KR-OT. We show here that it also helps to balance the amplitude of different seismic events. We design a practical workflow based on the GS-OT misfit function, coupled with an on-the-fly source estimation wavelet and a Gaussian-time window strategy. The method is applied to a synthetic case study from the SEAM II Foothill model. From crude velocity models, high resolution of VP and especially VS are obtained, using only sixteen seismic sources.
Monitoring of land use/land-cover dynamics using remote sensing: a case of Tana River Basin, Kenya

Abstract The present study assesses the spatio-temporal dynamics of land use/cover over a 28-year period in the upper Tana River Basin (TRB), Kenya using digital change detection techniques. The results indicate that during the last three decades, agricultural land and built-up area have increased by 32.57% (184,796 ha) and 26.35% (1460 ha) respectively, while open land, waterbodies and vegetation have decreased by 35.9%, 3.13% and 8.29% respectively. There was a huge expansion of agricultural land to marginal semi-arid and arid areas (lower part of the basin) over the period. The results of this study provide a better understanding of the spatial and temporal dynamics of the natural resources and form a basis for better planning and effective spatial organization. Such information can help various stakeholders including policy decision-makers in balancing development needs and river basin vital environmental systems protection and sustainability, especially in arid and semi-arid regions.