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Articles 9451 - 9480 of 59515

Full-Text Articles in Earth Sciences

Adaptation, Compatibility And Acceptability Of Grass-Legume Pastures In The Andean Region Of Colombia, E. Cárdenas, E. Castro May 2023

Adaptation, Compatibility And Acceptability Of Grass-Legume Pastures In The Andean Region Of Colombia, E. Cárdenas, E. Castro

IGC Proceedings (1977-2023)

In Colombia, the specialised dairy production system is located in the high altitude Andean region. Its main feed resources are pure stands of Pennisetum clandestinum or/and Lolium spp. Nevertheless, the present market conditions require highly competitive and quality forages year round. These forages should be produced with low inputs (irrigation, fertilisers and agrochemicals) and be resistant to pests and diseases. The objective of this research was to evaluate the adaptation, compatibility and acceptability of introduced forage species for sustainable pasture management.

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New Cultivars For High Quality, Persistent Legume-Grass Pastures In The Southern Usa, J. H. Bouton May 2023

New Cultivars For High Quality, Persistent Legume-Grass Pastures In The Southern Usa, J. H. Bouton

IGC Proceedings (1977-2023)

In the southern USA one cannot depend on perennial legume-grass pasture systems to have persistently high nutritive quality. 'Jesup' tall fescue, a cultivar with better persistence in the region than 'Kentucky 31', was re-infected with a non-ergot alkaloid producing strain of the Neotyphodium coenophialum fungal endophtye (MaxQTM) and found to give persistence equal to Jesup with its endemic strain (E+), but without animal toxins (Bouton et al., 2002). 'Durana' white clover (Bouton et al., 2004) was developed from regional ecotypes of Trifolium repens f. hollandicum germplasm and found to improve animal performance in both E+ and …

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Seed Productivity Of Festulolium And Lolium X Boucheanum Varieties, Iveta Gutmane, Aleksandr Adamovich May 2023

Seed Productivity Of Festulolium And Lolium X Boucheanum Varieties, Iveta Gutmane, Aleksandr Adamovich

IGC Proceedings (1977-2023)

Hybrid ryegrasses are intermediate lines between perennial ryegrass and Italian ryegrass as regards growth parameters, productivity and resistance. Good quality and digestibility of forage and higher yield are the main advantages of hybrid ryegrass over perennial ryegrass. Climatic conditions in the Baltic States and North Europe are not favourable enough for ryegrass cultivation but Festulolium is a prospective forage crop for this area (Nesheim, 2000, Adamovich, 2003). Ryegrasses, including hybrid ryegrasses, surpass Festulolium in forage quality. However, Festulolium persistance (resistance, winter-hardiness and, thus, high productivity) are noteworthy. Due to yield quality and competitive productivity, Festulolium may rank equally with timothy …

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Comparing Yield And Quality Of Milk From Dairy Cows Fed Stockpiled Annual Ryegrass (Lolium Multiflorum L.) And Cereal Rye (Secale Cereale L.), L. E. Meinhardt, R. L. Kallenbach May 2023

Comparing Yield And Quality Of Milk From Dairy Cows Fed Stockpiled Annual Ryegrass (Lolium Multiflorum L.) And Cereal Rye (Secale Cereale L.), L. E. Meinhardt, R. L. Kallenbach

IGC Proceedings (1977-2023)

Stockpiling annual ryegrass and cereal rye provides a low cost substitute to hay and creates an excellent source of feed during winter (Kallenbach et al., 2003). In addition to lowering feed costs, grazing increases the conjugated linoleic acid (CLA) content of milk compared to feeding hay. Previous research suggested that forage species might differ in their ability to alter milk CLA content during the growing season (Wu et al., 1997). However, research is needed to determine if different forage species used for winter and early spring grazing impacts the CLA content of milk. The objective of this experiment …

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A Grazing Method To Solve The Lack Of Pastures In The Dry Season Of Tropical Areas With Long Periods Of Drought, R. O. Martinez, R. Tuero, M. F. Díaz May 2023

A Grazing Method To Solve The Lack Of Pastures In The Dry Season Of Tropical Areas With Long Periods Of Drought, R. O. Martinez, R. Tuero, M. F. Díaz

IGC Proceedings (1977-2023)

Rotational grazing systems used in tropical areas in Latin America do not solve the great difference in pasture availability between the dry and the rainy season. The main studies on rational grazing (Voisin, 1963) were performed in temperate areas where the deficit of feeds in winter may only be solved with external feeds such as forages and silages produced out of the grazing system. The objective of this work was to demonstrate that it is possible to maintain pasture availability throughout the year with the use of a Pennisetum purpureum clone (Cuba CT-115) adapted to grazing (Martínez et al., …

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Breeding And Evaluation Of Forage Soyabeans, T. E. Devine May 2023

Breeding And Evaluation Of Forage Soyabeans, T. E. Devine

IGC Proceedings (1977-2023)

The principal use of soyabean in the US in the early 1900s was as livestock forage. Soyabeans are less expensive to establish than small seeded perennial legume forages and can provide legume protein after winter killing of perennial legumes. Soyabean can improve production distribution by vigorous growth during the hot summer season when traditional perennial legumes are less productive.

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Effect Of Utilisation Date On The Yield And Quality Of A Semi-Natural Grass Stand In Winter, Jiří Skládanka May 2023

Effect Of Utilisation Date On The Yield And Quality Of A Semi-Natural Grass Stand In Winter, Jiří Skládanka

IGC Proceedings (1977-2023)

Prolongation of the grazing period into the winter season reduces the costs of feedstuffs for dry cows. To enable the use of pastures in winter it is necessary to carry out the last cut or grazing cycle in June or July and to postpone the last grazing until the first week of August. (Opitz von Boberfeld, 1997). The time of the last utilisation in summer influences the yield and quality of herbage during the winter season (Bartholomew et al., 1997). This research studied changes in yield and quality of a semi-natural grass stand in autumn and in winter following …

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Annual Forage Legume Response To Herbicides Labelled For Lucerne Establishment, Twain J. Butler, R. Bow, J. P. Muir May 2023

Annual Forage Legume Response To Herbicides Labelled For Lucerne Establishment, Twain J. Butler, R. Bow, J. P. Muir

IGC Proceedings (1977-2023)

Weed competition reduces stand establishment, thus lowering forage production and quality. However, there are no herbicides labelled for annual legume establishment, despite several labelled for the establishment of lucerne (Medicago sativa). Some of these may be useful in the establishment and production of annual forage legumes. Lucerne herbicides have greater potential for use on other legumes, since they have grazing and feeding clearance. The objective of this paper is to summarize annual legume yield response trials to herbicides labelled for lucerne establishment.

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4d Flow Pattern Of The Longest Cave In The Eastern Alps (Schönberg-Höhlensystem, Totes Gebirge), Lukas Plan, Eva Kaminsky, Pauline Oberender, Clemens Tenreiter, Maximilian Wimmer May 2023

4d Flow Pattern Of The Longest Cave In The Eastern Alps (Schönberg-Höhlensystem, Totes Gebirge), Lukas Plan, Eva Kaminsky, Pauline Oberender, Clemens Tenreiter, Maximilian Wimmer

International Journal of Speleology

The Schönberg-Höhlensystem (SBH) is not only the longest cave system in the Eastern Alps (length 156 km, depth 1061 m), but a significant proportion of the passages have developed on or just below two surfaces that dip 1.7° to the NE. These so-called "speleogenetic phases" are rarely developed in caves of the Northern Calcareous Alps and have not yet been confirmed by detailed morphological mapping. Furthermore, the deep parts of the cave offer the possibility to study the active epiphreatic zone for a distance of 1.6 km. Detailed morphological mapping shows that the main level at about 1500 m a.s.l. …

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Structural Relationships Across The Sevier Gravity Slide Of Southwest Utah And Implications For Catastrophic Translation And Emplacement Processes Of Long Runout Landslides, Michael J. Braunagel, William Ashley Griffith, Robert F. Biek, David B. Hacker, Peter D. Rowley, David H. Malone, Danika Mayback, Tiffany A. Rivera, Zachary Loffer, Zachary D. Smith May 2023

Structural Relationships Across The Sevier Gravity Slide Of Southwest Utah And Implications For Catastrophic Translation And Emplacement Processes Of Long Runout Landslides, Michael J. Braunagel, William Ashley Griffith, Robert F. Biek, David B. Hacker, Peter D. Rowley, David H. Malone, Danika Mayback, Tiffany A. Rivera, Zachary Loffer, Zachary D. Smith

Faculty Publications - Geography, Geology, and the Environment

The physical processes that facilitate long-distance translation of large-volume gravity slides remain poorly understood. To better understand these processes and the controls on runout distance, we conducted an outcrop and microstructural characterization of the Sevier gravity slide across the former land surface and summarize findings of four key sites. The Sevier gravity slide is the oldest of three mega-scale (>1,000 km2) collapse events of the Marysvale volcanic field (Utah, USA). Field observations of intense deformation, clastic dikes, pseudotachylyte, and consistency of kinematic indicators support the interpretation of rapid emplacement during a single event. Furthermore, clastic dikes and characteristics of …

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Evaluation Of Temperature-Index And Energy-Balance Snow Models For Hydrological Applications In Operational Water Supply Forecasts, Tian Gan, David G. Tarboton, Tseganeh Z. Gichamo May 2023

Evaluation Of Temperature-Index And Energy-Balance Snow Models For Hydrological Applications In Operational Water Supply Forecasts, Tian Gan, David G. Tarboton, Tseganeh Z. Gichamo

Civil and Environmental Engineering Faculty Publications

In the western United States, snow accumulation, storage, and ablation affect seasonal runoff. Thus, the prediction of snowmelt is essential to improve the reliability of water supply forecasts to guide water allocation and operational decisions. The current method used at the Colorado Basin River Forecast Center (CBRFC) couples the SNOW-17 temperature index snow model and the Sacramento Soil Moisture Accounting (SAC-SMA) runoff model in a lumped approach. Limitations in parameter transferability and calibration requirements for changing conditions with the temperature-index model motivated this research, in which new avenues were investigated to assess and prototype the application of an energy-balance snow …

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Application Of Advanced Mathematical Approaches To The Interpretation Of Remote Sensing Observations Of The Surface Of Mars, John Randall Christian May 2023

Application Of Advanced Mathematical Approaches To The Interpretation Of Remote Sensing Observations Of The Surface Of Mars, John Randall Christian

Arts & Sciences Graduate Student Theses and Dissertations

Spectroscopic imagers have been used to analyze the surface of Mars at varying spatial scales in several distinct modalities, each of which provides different information about surface geology and geochemistry. In this dissertation, we take a closer look at two such spectroscopic imagers: the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board the Mars Reconnaissance Orbiter and the Planetary Instrument for X-ray Lithochemistry (PIXL) on board the Mars 2020 rover Perseverance. We apply new mathematical models to data collected by CRISM to infer physical properties from a complex (and therefore underutilized) portion of the spectrum, and to data collected …

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Deformation Of Hydrous Magnesium Silicates In Subduction Zone Environments, Charis Madeleine Horn May 2023

Deformation Of Hydrous Magnesium Silicates In Subduction Zone Environments, Charis Madeleine Horn

Arts & Sciences Graduate Student Theses and Dissertations

Hydrous magnesium silicates form primarily from the interaction of seawater with the oceanic lithosphere and are drawn down into the mantle by subducting slabs at convergent margins. It is thought that they hold an important control over several aspects of the subduction multisystem, with implications for many different subduction zone processes. In particular, the hydrous magnesium silicates serpentine and talc exhibit unusual rheological and anisotropic properties. To explore the effects of these minerals on global subduction zones, we conducted three separate studies on talc (Mg3Si4O10(OH)2) and two of the serpentine group minerals (Mg3Si2O5(OH)4), lizardite and antigorite. Firstly, to understand the …

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Downstream Gradients In Unit Stream Power Influence Log Jam Location And Process Domain, Eliza H. Malakoff May 2023

Downstream Gradients In Unit Stream Power Influence Log Jam Location And Process Domain, Eliza H. Malakoff

Dartmouth College Master’s Theses

Growing calls for the use of natural materials and processes to meet management goals have positioned artificial log jams as a compelling alternative to hard engineering instream and floodplain habitat. Deep uncertainties remain, however, about where and how wood should be placed to best mimic natural river processes. In this study, I test whether at-a-point or downstream gradients in unit stream power, an estimate of a river’s ability to do work, exert control over where and how log jams form. Using field observations of 360 log jams in New Hampshire and Vermont and an additional 320 previously published locations of …

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Bulk Hydrogen Isotopes In Ordinary Chondrites, Michael J. Cato May 2023

Bulk Hydrogen Isotopes In Ordinary Chondrites, Michael J. Cato

Earth and Planetary Sciences ETDs

Bulk hydrogen isotopes in nominally anhydrous meteorites are a key component in our understanding of the distribution of hydrogen in our solar system, including the provenance of water on the Earth. Here, we develop a step-heated continuous-flow method to measure the bulk hydrogen isotopes in nominally anhydrous rocks and use this method to significantly increase the dataset of bulk hydrogen isotopes in ordinary chondrites, nearly doubling the number of equilibrated members. We found that as thermal alteration increases from petrologic type 3.0 to 4, there is a correlated decrease in both hydrogen content and isotope ratio, followed by no significant …

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Landslide Forecast In Taiwan Based On Machine Learning In The Gis Field, Yi Shen May 2023

Landslide Forecast In Taiwan Based On Machine Learning In The Gis Field, Yi Shen

Honors Capstones

Landslides can pose a significant risk to life, property, and infrastructure in mountainous regions, and can be triggered by various factors, including intense rainfall, earthquakes, and water level changes. Machine learning is commonly used to forecast landslides, based on statistical relationships between past landslides and multiple variables to create a general forecasting model. However, these models often require large amounts of data to achieve accurate results. This project aims to use only a few variables but take advantage of both their spatial distribution and temporal trends to improve the accuracy of landslide forecasts. This approach is tested in Taiwan, a …

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Estimating Snow Accumulation And Ablation With L-Band Interferometric Synthetic Aperture Radar (Insar), Jack Tarricone, Ryan W. Webb, Hans-Peter Marshall, Anne W. Nolin, Franz J. Meyer May 2023

Estimating Snow Accumulation And Ablation With L-Band Interferometric Synthetic Aperture Radar (Insar), Jack Tarricone, Ryan W. Webb, Hans-Peter Marshall, Anne W. Nolin, Franz J. Meyer

Geosciences Faculty Publications and Presentations

Snow is a critical water resource for the western United States and many regions across the globe. However, our ability to accurately measure and monitor changes in snow mass from satellite remote sensing, specifically its water equivalent, remains a challenge. To confront these challenges, NASA initiated the SnowEx program, a multiyear effort to address knowledge gaps in snow remote sensing. During SnowEx 2020, the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) team acquired an L-band interferometric synthetic aperture radar (InSAR) data time series to evaluate the capabilities and limitations of repeat-pass L-band InSAR for tracking changes in snow water equivalent …

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Development And Evaluation Of An Automated Tactical Tillage Tool To Control Weeds In Row-Crop Production Systems, Grace Mccormick Friday May 2023

Development And Evaluation Of An Automated Tactical Tillage Tool To Control Weeds In Row-Crop Production Systems, Grace Mccormick Friday

Theses and Dissertations

Weed control is an integral part of a successful overall production strategy in row- cropping systems and has the potential to reduce or eliminate yield losses that negatively affect profitability. Timely and correctly selected herbicide applications are the major keys for effective weed control in a majority of instances. However, there are negative factors that contribute to ineffectiveness and weed escape issues that currently lack viable options for management. Sparsely populated late-season weeds that emerge after lay-by herbicide applications and weeds that have become tolerant and resistant to traditional herbicide chemistries are of greatest concern. Historically, these weeds would have …

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Evaluating The Relationship Between Methane Seeps And Seafloor Geomorphology On The Northern Us Atlantic Margin, Gabriel Hernandez May 2023

Evaluating The Relationship Between Methane Seeps And Seafloor Geomorphology On The Northern Us Atlantic Margin, Gabriel Hernandez

Theses and Dissertations

Methane seeps are a transport pathway for carbon from seafloor sediments to the marine environment with important implications for global biogeochemical cycling. Accordingly, there is substantial interest in better understanding the processes that control seep location and predicting the distribution of seeps with existing seafloor datasets. Visual evaluation of methane seeps, in multibeam sonar water column data, suggests a spatial relationship between seeps and specific seafloor morphologic features such as ridge crests. In this thesis, seafloor geomorphology at 1996 seep detection sites on the US Atlantic margin was quantitatively characterized by geomorphologic phonotype, bathymetric position index, slope, rugosity, and aspect …

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Limits Of Tectonic Reactivation On Mars Using Earth Analogue Analysis And Numerical Modeling, Jonathan Rich May 2023

Limits Of Tectonic Reactivation On Mars Using Earth Analogue Analysis And Numerical Modeling, Jonathan Rich

Theses and Dissertations

Recent geodynamic modeling studies suggest that the geometry of structural landforms in the Ouachita Mountains (OM) has been influenced by the reactivation of a weak scar in the mantle-lithosphere during intracontinental orogenesis. As deformation on one-plate planets such as Mars can be considered intracontinental, and impact cratering deeply scarred the Martian lithosphere, we hypothesize that structural geometries on Mars may also reflect heterogenous networks of lithospheric scarring. To investigate this hypothesis, we model the pre-erosional fold structure of the Maumelle Chaotic Zone in the OM to compare fault and fold geometries with that of the seismically-imaged mantle-lithosphere scar. We then …

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Rapidly Changing Range Limits In A Warming World: Critical Data Limitations And Knowledge Gaps For Advancing Understanding Of Mangrove Range Dynamics In The Southeastern Usa, Rémi Bardou, Michael J. Osland, Steven Scyphers, Christine Shepard, Karen E. Aerni, Jahson B. Alemu I, Robert Crimian, Richard H. Day, Nicholas M. Enwright, Christopher A. Gabler May 2023

Rapidly Changing Range Limits In A Warming World: Critical Data Limitations And Knowledge Gaps For Advancing Understanding Of Mangrove Range Dynamics In The Southeastern Usa, Rémi Bardou, Michael J. Osland, Steven Scyphers, Christine Shepard, Karen E. Aerni, Jahson B. Alemu I, Robert Crimian, Richard H. Day, Nicholas M. Enwright, Christopher A. Gabler

School of Earth, Environmental, & Marine Sciences Faculty Publications

Climate change is altering species’ range limits and transforming ecosystems. For example, warming temperatures are leading to the range expansion of tropical, cold-sensitive species at the expense of their cold-tolerant counterparts. In some temperate and subtropical coastal wetlands, warming winters are enabling mangrove forest encroachment into salt marsh, which is a major regime shift that has significant ecological and societal ramifications. Here, we synthesized existing data and expert knowledge to assess the distribution of mangroves near rapidly changing range limits in the southeastern USA. We used expert elicitation to identify data limitations and highlight knowledge gaps for advancing understanding of …

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Paleotemperature Estimates From Diatom Morphometrics In The Amundsen Sea For Marine Isotope Stage 5, Cesar Lopez May 2023

Paleotemperature Estimates From Diatom Morphometrics In The Amundsen Sea For Marine Isotope Stage 5, Cesar Lopez

Honors Capstones

Because of ever rising temperatures driven by anthropogenic climate change, much attention has been given to the West Antarctic Ice Sheet (WAIS) by the scientific community. This is due to its sensitivity to global climate change and vulnerability for collapse as evidenced by Pleistocene interglacial events. Paleotemperature estimates from the Amundsen Sea are crucial for understanding how global temperature changes impacted WAIS throughout the Pleistocene. Marine Isotope Stage 5 (MIS 5) is of particular interest as it contains different substages and intervals of fluctuating temperatures. This period also is estimated to have had temperatures equal to, or slightly higher than …

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Small Community Water Systems Have The Highest Prevalence Of Mn In Drinking Water In California, Usa, Miranda Aiken, Samantha C. Ying May 2023

Small Community Water Systems Have The Highest Prevalence Of Mn In Drinking Water In California, Usa, Miranda Aiken, Samantha C. Ying

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Manganese (Mn) is currently regulated as a secondary contaminant in California, USA; however, recent revisions of the World Health Organization drinking water guidelines have increased regulatory attention of Mn in drinking water due to increasing reports of neurotoxic effects in infants and children. In this study, Mn concentrations reported to California’s Safe Drinking Water Information System were used to estimate the potentially exposed population within California based on system size. We estimate that between 2011 and 2021, over 525,000 users in areas with reported Mn data are potentially exposed to Mn concentrations exceeding the WHO health-based guideline (80 μg L …

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Investigation Of The Sheep Creek Carbonatites, Ravalli County, Montana, Sarah Risedorf May 2023

Investigation Of The Sheep Creek Carbonatites, Ravalli County, Montana, Sarah Risedorf

Graduate Theses & Non-Theses

Carbonatite-related REE-Nb mineralization in southern Ravalli County, Montana was first discovered in the late 1950s and early 1960s. Over 30 discontinuous carbonatite bodies occur in a ~ 10 km2 area centered on Sheep Creek, a tributary to the headwaters of the West Fork of the Bitterroot River (WFBR). The deposits are contained in a belt that extends to the southeast into the Mineral Hill district of Lemhi County, Idaho. Country rocks include a deformed and metamorphosed bimodal igneous suite of diabase and A-type granite, both dated to 1.37 Ga by previous workers. These rocks are locally metamorphosed to amphibolite …

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Improving The Cotton Simulation Model, Gossym, For Soil, Photosynthesis, And Transpiration Processes, Sahila Beegum, Dennis Timlin, Kambham Raja Reddy, Vangimalla Reddy, Wenguang Sun, Zhuangji Wang, David Fleisher, Chittaranjan Ray May 2023

Improving The Cotton Simulation Model, Gossym, For Soil, Photosynthesis, And Transpiration Processes, Sahila Beegum, Dennis Timlin, Kambham Raja Reddy, Vangimalla Reddy, Wenguang Sun, Zhuangji Wang, David Fleisher, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

GOSSYM, a mechanistic, process-level cotton crop simulation model, has a two-dimensional (2D) gridded soil model called Rhizos that simulates the below-ground processes daily. Water movement is based on gradients of water content and not hydraulic heads. In GOSSYM, photosynthesis is calculated using a daily empirical light response function that requires calibration for response to elevated carbon dioxide ( CO2). This report discusses improvements made to the GOSSYM model for soil, photosynthesis, and transpiration processes. GOSSYM’s predictions of below-ground processes using Rhizos are improved by replacing it with 2DSOIL, a mechanistic 2D finite element soil process model. The photosynthesis …

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The Dynamics Of Sedimentary Chlorophyll Α At A High-Energy Beach, Sarah (Gray) Abel May 2023

The Dynamics Of Sedimentary Chlorophyll Α At A High-Energy Beach, Sarah (Gray) Abel

Honors Theses

Productive sandy beaches are one of the most crucial areas serving our ecosystem today. While often overlooked in scientific research, productive beaches have many essential functions that lead to the preservation and protection of many different species as well as ecological wellness and stability. A key factor that is linked to this productivity is the presence of chlorophyll in the sediments. Piston cores of the sediments at the low-tide mark at Waties Island, South Carolina, were collected across multiple years and subsequently analyzed for chlorophyll concentrations through fluorometry after acetone extraction and acidification. Each core profile was processed to calculate …

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Investigation Of A Possible Switch Of Benthic Photosynthetic Organisms And Phytoplanktonic Organisms In White Point Swash, South Carolina, Nathan Easterling May 2023

Investigation Of A Possible Switch Of Benthic Photosynthetic Organisms And Phytoplanktonic Organisms In White Point Swash, South Carolina, Nathan Easterling

Honors Theses

This research study examined the possible switch from benthic photosynthetic organisms to phytoplankton in the water column at White Point Swash, Long Bay, South Carolina, and what is causing this switch to occur. During Dr. Hannides’ and his group’s studies at this and other swashes in the past, they noticed this phenomenon of the benthic photosynthetic organisms taking over during a certain time and then the phytoplankton in the water column taking over during a different time. In this study, I measured the relative benthic macroalgal area coverage and sedimentary chlorophyll a concentration as measures of the abundance of benthic …

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Suboxic And Anaerobic Respiration Across A Sandy-Shore-To-Estuarine Gradient, Jacey Ballard May 2023

Suboxic And Anaerobic Respiration Across A Sandy-Shore-To-Estuarine Gradient, Jacey Ballard

Honors Theses

Sulfate is an inorganic ion that is one of the major ions of seawater. Sulfate is also an essential reactant in microbially mediated anaerobic respiration that produces sulfide, an energy source during chemosynthesis. Sulfide is widely found in sediment, and water rich in decaying organic material, as well as hydrothermal vents. While sulfate reduction occurs extensively in muds, such as those of marshes, it is not expected to occur in sand which is much better aerated. Recent research in our group documented extensive sub aerobic respiration in coastal sands which suggests that sulfate reduction may have also been happening. This …

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Improvements To Isru For Rocket Fuel Generation, Justin Sharp May 2023

Improvements To Isru For Rocket Fuel Generation, Justin Sharp

James Madison Undergraduate Research Journal (JMURJ)

The development of efficient in-situ resource utilization (ISRU) technologies is crucial for the establishment of an extraterrestrial, self-sustaining colony. The generation of rocket fuel at potential colony locations is necessary to provide the transportation of people and cargo to and from these locations.Three processes are discussed for the improvement of ISRU methods to generate rocket fuel: electrolysis and electrochemical improvements to the process of crude fuel production, physical and chemical methods for separation of gaseous H2 and O2, and materials and cryogenics engineering for storage and transportation of liquid hydrogen (LH2) and liquid oxygen (LOX). Storage and transportation of cryogenics …

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Downstream Hydrochemistry And Irrigation Water Quality Of The Syr Darya, Aral Sea Basin, South Kazakhstan, Bagdat Satybaldiyev, Baimurat Ismailov, Nurbek Nurpeisov, Kairat Kenges, Daniel D. Snow, Arindam Malakar, Omirzhan Taukebayev, Bolat Uralbekov May 2023

Downstream Hydrochemistry And Irrigation Water Quality Of The Syr Darya, Aral Sea Basin, South Kazakhstan, Bagdat Satybaldiyev, Baimurat Ismailov, Nurbek Nurpeisov, Kairat Kenges, Daniel D. Snow, Arindam Malakar, Omirzhan Taukebayev, Bolat Uralbekov

Daugherty Water for Food Global Institute: Faculty Publications

New hydrochemical measurements from the Syr Darya provide insights into factors affecting the composition and quality of a major freshwater source replenishing the Aral Sea. This river is heavily used for power and irrigation and crosses territories of four Central Asia republics. It is intensely managed, draining several major tributaries, many reservoirs, and numerous irrigation distribution systems and canals. Analysis of seasonal changes in dissolved ion concentrations using geochemical diagrams, elemental ratios, statistical correlation, and equilibrium modeling allowed the characterization of mineral formation processes that control the dissolved chemical composition. Measured water hydrochemistry and composition type differs substantially from previous …

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