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Advancing Louisiana\u27s Cropping Systems: Sustainable Bioenergy Production, Cover Crops, and Technology Integration
Get PDFThe adoption of cover crops in Louisiana is lower than the national average, underscoring the need for region-specific research to address environmental challenges and demonstrate the short-term benefits of these practices within existing production systems. This research evaluated the integration of cover crops (CC) in energy cane (Saccharum spp.) and no-till cotton systems, focusing on their effects on soil health, nitrogen (N) management, and biomass production. Soil health indicators (SHIs), including enzymatic activities (β-glucosidase, β-glucosaminidase, and urease), protein N, inorganic N concentrations (nitrate and ammonium), soil organic matter (SOM), and microbial community composition assessed through ester-linked fatty acid methyl esters (EL-FAME), were monitored. Additionally, precision agriculture tools, such as vegetation indices (normalized difference vegetation index -NDVI and normalized difference red-edge index -NDRE) and Real-Time Kinematic GPS (RTK GPS)-derived Digital Elevation Models (DEMs), were used to quantify cover crop benefits. The first study explored a rotation system integrating sweet sorghum (Sorghum bicolor (L.) Moench) during energy cane fallow periods, alongside winter cover crops and residue management strategies. The results indicated that integrating sweet sorghum with full residue retention from energy cane substantially enhanced total biomass feedstock. Conversely, the complete removal of residues notably decreased the total biomass feedstock. Although winter cover crops suppressed weed infestation in clay soils, they did not affect energy cane yields or SHIs, indicating limited short-term impacts on soil health. The second study assessed cover crops in no-till cotton (Gossypium spp.) systems under different N application rates. CCs showed no significant short-term effects on cotton yield, SHIs, or microbial communities. However, mix treatment -crimson clover (Trifolium incarnatum) + cereal rye (Secale cereale) achieved the lowest optimal N fertilization rate (EONR) at 98.05 kg N ha⁻¹. Crimson clover treatment produced high yields with a moderate N fertilization rate (140 kg N ha⁻¹), and the fallow treatment achieved the highest yield but required significantly higher N inputs (211 kg N ha⁻¹) than other CC treatments, indicating lower N efficiency and highlighting the potential N value of CC to reduce synthetic fertilizer reliance. The third study DEMs effectively monitored seedbed-furrow height as a proxy for soil erosion, while NDVI and NDRE correlated with CC biomass accumulation at specific days after planting. These findings highlight the potential of cover crops and advanced technologies to enhance agricultural sustainability and support broader adoption of these practices in Louisiana
ASSESSING WATER QUANTITY AND QUALITY IN THE MISSISSIPPI RIVER VALLEY ALLUVIAL AQUIFER AND COASTAL LOUISIANA THROUGH INTEGRATED AIRBORNE ELECTROMAGNETIC AND BOREHOLE DATA
Get PDFNumerical modeling has contributed significantly to the understanding of groundwater systems. Many challenges are associated with constructing groundwater models which include an accurate understanding of the geology and aquifer parameters estimation. Traditionally boreholes are a successful way to capture geological features, however, boreholes often have sparse data. Airborne electromagnetic (AEM) data allows for efficient and cost-effective surveying of large areas, providing valuable information about the subsurface electrical resistivity. By bridging the gap between boreholes, AEM data offers a broader view of the aquifer system\u27s structure and heterogeneity. However, interpreting geophysical AEM data has uncertainties. Developing a framework to apply the data fusion concept on boreholes and AEM data is one of the challenges addressed in the first part of this study. The framework introduces depth-dependent resistivity thresholds and unsupervised clustering to classify resistivity into lithofacies, reducing interpretation uncertainties. Applied to the Mississippi River Valley alluvial aquifer (MRVA), the second most-pumped US aquifer, it improves lithofacies models and reduces estimation uncertainties. Employment of AEM resistivity data in groundwater quality, the second part introduces a transformation from resistivity to subsurface quality using a deep learning model and regression formulas that predict chloride concentration using location, AEM resistivity, borehole data, and water quality data. This method gives us a clear picture of the saltwater plumes in 3D for the first time. By mapping the extent and intensity of salinity in the MRVA aquifer, the model provides valuable insights into the sources and controls of groundwater salinity, supporting proactive water resources management. As the final goal of this study, a detailed groundwater model was constructed based on the complex geological model from the data fusion study. This study generates maps to guide risk-based water management decisions and protect aquifer resources by delineating the cones of depression. Moreover, it highlights the significant influence of increased groundwater pumping on groundwater levels and fresh groundwater, evaluating changes in up-coning from deeper saline aquifers through a coupled flow-transport model which enhances our understanding of groundwater flow and storage responses to excessive withdrawals. Ultimately, these findings offer critical insights for effective groundwater management in regions experiencing substantial pumping pressures
Non-Reciprocity, Metastability, and Dynamic Reconfiguration in Co-Assembly of Active and Passive Particles
No full textLiving organisms often exhibit non-reciprocal interactions where the forces acting on the objects are not equal in magnitude or opposite in direction. The combination of reciprocal and non-reciprocal interactions between synthetic building blocks remains largely unexplored. Here, out-of-equilibrium assemblies of non-motile isotropic passive and metal-patched motile active particles are formed by overlapping bulk interactions with directed self-propulsion. An external alternating current (AC) electric field generates concurrent dipolar and induced-charge electrophoretic forces between the particles which are evaluated using microscopy. The interaction force measurements allow to determine the degree of reciprocity in interactions, which is tunable by designing the active particle and its trajectory. While linearly-propelled active particles evade assembly with passive particles, helically propelled active particles form active-passive clusters with dynamic reconfiguration and long-lived metastability. Large clusters display programmable fluctuations and reconfigurability by controlling the fraction of active particles. The study establishes principles of integrating reciprocal and non-reciprocal interactions in guided colloidal assembly of reconfigurable metastable structures
Le Phénomène des Enfants de la Rue dans la Société Contemporaine Africaine : Une Etude de la Voix de ma Rue de Sylvain Kean- Zoh et Allah n\u27Est pas Obligé d\u27Ahmadou Kourouma
No full textLes auteurs ont toujours dans leurs perspectives tenter de narrer les faits de la société qui relèvent de leur vécus quotidiens. Ainsi nonbreux sont les auteurs de la période post-indépendante qui s\u27intéressent plûtot à de nouveaux fléaux ravageant la société contemporaine africaine d\u27où le phénomène des enfants de la rue en Afrique. C\u27 est cette dimension de la littérature qui dénonce ce fléau qui attire notre attention sur ce travail.
Cette étude analyse le phénomène des enfants de la rue dans la société africaine de nos jours , les risques, dangers de ce fléau devenu récurent à travers la voix de ma rue de Sylvain Kean-Zoh et Allah n\u27est pas obligé d\u27Ahmadou Kourouma. L\u27usage de la sociocritique et la socioréalististe permettent d\u27identifier les aspects, perspectives ,faits politiques, économiques et culturels... pour mettre à nu ce fléau considerable qui relève de nos vécus quotidiens
Intermittent CO2 electrolysis needs its time in the sun
No full textTaking advantage of the potentially low-cost and environmentally friendly nature of renewable energy sources like wind and photovoltaics has long been the aim of the CO2 electrolysis field. However, there have been sparse reports on the economic and performance implications of coupling these two systems. In this perspective, we present lessons that can be taken from work done in water electrolysis, summarize the progress that has been made in coupling electrochemical CO2 reduction systems to intermittent renewable energy sources, and perform a brief economic analysis on energy versus product storage in intermittent systems. Finally, we recommend future research directions, including rigorous studies on the effects of dynamic operation on electrolyzer components, strategies for integrating with continuous downstream processes, synergistic post-product processing via electrification technologies, and leveraging of artificial intelligence and automation to mitigate the unpredictability of CO₂ electrolysis
Non-Orientable Surfaces Bounded by Knots
Get PDFThe non-orientable 4-genus of a knot in is defined to be the minimum first Betti number of a non-orientable surface in so that bounds . We will survey the tools used to compute the non-orientable 4-genus, and use various techniques to calculate this invariant for non-alternating 11 crossing knots, torus knots, and Whitehead doubles. We also will view obstructions to a knot bounding a M\ {o}bius band given by the double branched cover of branched over . Additionally, we discuss the problem of the Whitehead double of the Figure 8 knot and survey commonly used techniques to obstructing sliceness. We improve bounds in general for the non-orientable 4 genus of -twisted Whitehead doubles and provide genus 1 non-orientable cobordisms to cable knots. We conclude with examining knot traces, which are 4-manifolds obtained by attaching a 2-handle to along a knot with framing , denoted . Previous work has analyzed knots that do not bound a smoothly embedded disk in , yet there exists an so that a smoothly embedded generates the second homology, . We examine the non-orientable analog, a smoothly embedded generating , and discuss techniques and tools for both the orientable and non-orientable setting
Passive Vibration Isolation Systems for Mitigating Rotational Forces in Football Helmet Impacts
Get PDFHelmets have been used for centuries to mitigate head injuries, evolving with advancements in materials and design. They are critical in athletics, construction, and military applications, where shock and vibration isolation play a key role in head protection. Helmet performance is currently rated using the Head Injury Criterion (HIC) and Helmet Performance Score (HPS) metrics. HIC is a metric used in sports and automotive industries which focuses on the probability of injury occurring due to the magnitude and duration of linear acceleration of the head [1]. The HPS metric was created by using a linear combination of HIC and a third metric known as the Diffuse Axonal Multi-Axis General Evaluation (DAMAGE) [2]. Prior research found that including rotational accelerations with linear accelerations could improve the HPS by 48% or more [3]. From this research, it was theorized that a form of shock absorption technology with specific stiffness and damping mechanical properties would significantly enhance football helmet performance. Various materials, manufacturing methods, and structural designs were tested to achieve the target mechanical properties. The finalized shock absorbers were then integrated into a prototype helmet featuring carbon fiber helmet shells, 3D-printed fasteners, and pre-existing helmet components. The prototype is pending evaluation using NFL-standard testing protocols to be compared to current helmets. While in early development, this research highlights the potential for substantial advancements in helmet safety, offering what could be a promising approach to reducing head injuries in sports and beyond
Parts That Cannot Be Found
No full textParts That Cannot Be Found is a body of work where I use imagery of trees that are sick or injured, to show my struggles as a person who has been in survival mode their whole life. I use the facts I found in the book “The Hidden Life of Trees,” by Peter Wohlleben, where he describes what trees do and how and why they feel. Since I hold trees in high regard, I started researching how they function. Trees are living beings, and ignoring their presence is tragic. Throughout this paper, I contextualize my work by exploring specific printmaking mediums such as lithography, intaglio, and papermaking. My prints of the tangled roots, and deforestation and dead plant life express my struggles with PTSD and the slow process of healing
Effect of training status on muscle excitation and neuromuscular fatigue with resistance exercise with and without blood flow restriction in young men
Get PDFThis study compared muscle (vastus lateralis) excitation, muscle activation, and neuromuscular fatigue in response to low-load resistance exercise with blood flow restriction (LLBFR), medium-load resistance exercise with blood flow restriction (MLBFR), and high-load resistance exercise (HLRE) in resistance-trained (RT; n = 15) and untrained (UT; n = 14) college-aged males. Muscle excitation and activation were measured using surface electromyography (sEMG) and defined as the maximal root mean square amplitudes (RMS AMP) and the integrated area under the sEMG curve (iEMG) per repetition. Neuromuscular fatigue was defined as the reduction in peak torque measured during the postexercise knee extensor maximal isometric contractions (MVIC) relative to the pre-exercise MVIC. The LLBFR sessions showed 23.7% (p \u3c 0.01) lower relative muscle excitation than the MLBFR and 26.7% (p \u3c 0.001) lower than the HLRE. In contrast, LLBFR sessions showed 38.1% (p \u3c 0.001) higher total muscle activation than the MLBFR and 19.3% (p \u3c 0.05) higher than the HLRE. There were no differences between the RT and UT groups for percent change in peak torque or the RMS AMP measured during the knee extensor MVICs following the three exercise treatments (p \u3e 0.05). However, the peak torque and maximal RMS amplitudes were higher in the RT group than in the UT group measured during the pre-exercise MVICs. Our data suggest that the LLBFR led to greater total muscle activation than MLBFR and HLRE despite lower relative muscle excitation independent of training status in our college-aged males