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Intake Characteristics Of Diploid And Tetraploid Perennial Ryegrass Varieties When Grazed By Simmental X Holstein Yearling Heifers Under Rotational Stocking Management, R. J. Orr, J. E. Cook, K. L. Young, R. A. Champion, A. J. Rook Feb 2023

Intake Characteristics Of Diploid And Tetraploid Perennial Ryegrass Varieties When Grazed By Simmental X Holstein Yearling Heifers Under Rotational Stocking Management, R. J. Orr, J. E. Cook, K. L. Young, R. A. Champion, A. J. Rook

IGC Proceedings (1977-2023)

Orr et al. (2003) measured large differences in dry matter (DM) intake rate between 15 intermediate-heading perennial ryegrass varieties when they were continuously stocked with sheep and subsequently explored the extent to which, for 5 of these varieties, these differences could be explained by chemical and morphological traits (Orr et al., 2004a) which could be targeted in grass breeding programmes. Here, four of the 15 varieties, which within ploidy had low or high intake characteristics when grazed by sheep, were rotationally stocked with cattle and intake and sward factors were measured.


Optimising Financial Return From Grazing In Temperate Pastures, P. Dillon, J. R. Roche, L. Shalloo, B. Horan Feb 2023

Optimising Financial Return From Grazing In Temperate Pastures, P. Dillon, J. R. Roche, L. Shalloo, B. Horan

IGC Proceedings (1977-2023)

Key Points

  1. The increased interest in pasture-based systems of milk production in recent years has been largely generated through lower product prices and rising costs of production.

  2. Pasture based systems of milk production decrease unit production costs, through lower feed and labour expenses, and reduced capital investment.

  3. Systems utilising grazed pasture will be optimised in regions where pasture production potential is high, variability in seasonal pasture supply and quality is low, manufacturing milk accounts for a large proportion of total production, and where large areas of land are available at relatively low cost.

  4. Pasture based systems may allow greater global …


Challenges And Opportunities For Animal Production From Temperate Pastures, D. A. Clark Feb 2023

Challenges And Opportunities For Animal Production From Temperate Pastures, D. A. Clark

IGC Proceedings (1977-2023)

Key points

  1. Temperate pastures offer a major opportunity to reduce the feed costs associated with ruminant production.

  2. Pastures offer unique opportunities for producing high value components in feedstuffs that are beneficial to human health.

  3. The increased use of pasture will not automatically lead to improved environmental outcomes – difficult challenges exist in reducing nitrogen and greenhouse gas pollution.

  4. Grazed pasture systems offer advantages in animal welfare, provided management avoids the problems associated with climatic extremes, and the toxins associated with some pastures.

  5. To remain competitive with total mixed ration systems, and environmentally acceptable, pastures with higher intake characteristics that allow …


Decision Support For Temperate Grasslands: Challenges And Pitfalls, J. R. Donnelly, L. Salmon, R. D. H. Cohen, Zl. Liu, Xp. Xin Feb 2023

Decision Support For Temperate Grasslands: Challenges And Pitfalls, J. R. Donnelly, L. Salmon, R. D. H. Cohen, Zl. Liu, Xp. Xin

IGC Proceedings (1977-2023)

Key points

  1. Successful adoption of decision support tools (DS tools) to address grassland management issues requires careful attention in design to ensure ease-of-use, accuracy in prediction and the flexibility to simulate actual practices.

  2. DS tools must handle spatial variability and where possible include facilities for automatic sourcing of essential information for initialisation.

  3. Advances in the development of DS tools will depend on resolution of scientific issues in grassland biology including investment in dedicated experiments to determine parameter values for model equations.

  4. The use of mechanistic models, the integration of remote sensing technology and cooperation between research groups to develop modular …


Modelling Of Herbage Intake And Milk Production By Grazing Dairy Cows, Rémy Delagarde, M. O'Donovan Feb 2023

Modelling Of Herbage Intake And Milk Production By Grazing Dairy Cows, Rémy Delagarde, M. O'Donovan

IGC Proceedings (1977-2023)

Key-points

  1. Models predicting intake and performance of grazing ruminants from animal, sward, grazing and supplements characteristics are rare, but they are now included in several decision support systems (DSS).

  2. An evaluation of the performance and accuracy of published models are rarely undertaken by their authors, but this is proposed in this paper.

  3. There is still a need for experimental research but also for the development of generic and dynamic models to predict intake and performance over a wide range of grazing conditions.


Grass Growth Modelling: To Increase Understanding And Aid Decision Making On-Farm, P. D. Barrett, A. S. Laidlaw Feb 2023

Grass Growth Modelling: To Increase Understanding And Aid Decision Making On-Farm, P. D. Barrett, A. S. Laidlaw

IGC Proceedings (1977-2023)

Key points

  1. Crop and grass growth models have been developed over the last 50 years, or so, but general appreciation of their benefits and potential has been recognised only relatively recently. The most popular application of grass growth models has traditionally been for knowledge understanding.

  2. There is growing awareness of the potential of models in decision support systems (DSS) applications to aid pasture management and grassland budgeting on dairy farms.

  3. Although some models have been developed for DSS, their widespread uptake in industry has been slow; challenges still exist which need to be addressed in order to improve their precision …


Genetic Characteristics Required In Dairy And Beef Cattle For Temperate Grazing Systems, F. Buckley, C. Holmes, M. G. Keane Feb 2023

Genetic Characteristics Required In Dairy And Beef Cattle For Temperate Grazing Systems, F. Buckley, C. Holmes, M. G. Keane

IGC Proceedings (1977-2023)

Key points

  1. Only about 10% of the world’s milk is produced from grazing systems. Consequently the majority of dairy cattle have not been selected under grazing, nor on seasonal systems. This is not true for beef cattle, for which the majority, especially the dams, are managed under seasonal grazing systems.

  2. In grazing systems daily feed intake is limited to lower levels than are achievable on concentrate plus conserved forage rations. Consequently, cows most suited to grazing environments are likely to have a lower genetic potential for milk production than cows selected in high concentrate systems, to minimise their relative energy …


New Insights Into The Nutritional Value Of Grass, D. H. Rearte Feb 2023

New Insights Into The Nutritional Value Of Grass, D. H. Rearte

IGC Proceedings (1977-2023)

Key points

  1. The rumen environment in cattle grazing high quality forage is different to that reported for cattle fed indoors with diets based on processed feedstuffs.
  2. Temperate pasture is an excellent source of nutrients for ruminants but a high energy:protein imbalance can occur when it is offered at the stage of optimal digestion.
  3. Beef and milk produced on grass in temperate regions have a composition with nutritional advantages over beef or milk produced in indoor systems based on concentrate.
  4. Increasing water soluble carbohydrate content of grasses would diminish environmental contamination by reducing the excretion of urea through the urine.
  5. Increasing …


Plant And Sward Characteristics To Achieve High Intake In Ruminants, W. J. Wales, C. R. Stockdale, P. T. Doyle Feb 2023

Plant And Sward Characteristics To Achieve High Intake In Ruminants, W. J. Wales, C. R. Stockdale, P. T. Doyle

IGC Proceedings (1977-2023)

Key points

  1. Intake is affected by complex interactions between signals from the digestive tract, intermediary metabolism and energy supply, and behavioural signals associated with learned behaviours or sensory signals.
  2. The ideal sward needs to have characteristics that are similar to total mixed rations to achieve high intake and animal performance.
  3. Genetic manipulation of plants may offer an accelerated rate of plant improvement, but benefits need to be demonstrated in a systems context.


Overview Of Animal Production From Pastures In Ireland, M. J. Drennan, A. F. Carson, S. Crosse Feb 2023

Overview Of Animal Production From Pastures In Ireland, M. J. Drennan, A. F. Carson, S. Crosse

IGC Proceedings (1977-2023)

Key points

The importance of grassland to agriculture in Ireland is indicated by the fact that:

  1. Sixty percent of agricultural output is from grassland as cattle, milk and sheep products.
  2. Over 90% of the total farmed area is in grass.
  3. Livestock are almost entirely dependent on grazed grass for 200 to 235 days of the year.
  4. Grass conserved as silage is the main source of fodder in winter.
  5. To improve competitiveness changes are continuously taking place, which include:
  • increased suckler herd size and a movement to late maturing continental cattle breeds;
  • movement in the dairy herd towards Holstein with increased …


A Diagnostic Framework For Reengineering Soil: Potential Strategies To Manage Combinations Of Soil Constraints For Sands And Texture Contrast Soils, Gaus Azam, Stephen Davies Feb 2023

A Diagnostic Framework For Reengineering Soil: Potential Strategies To Manage Combinations Of Soil Constraints For Sands And Texture Contrast Soils, Gaus Azam, Stephen Davies

Natural resources published reports

This report is an output of project DAW1902-003RTX ‘Reengineering soils to improve the access of crop root systems to water and nutrients stored in the subsoil’, supported by a co-investment between the Department of Primary Industries and Regional Development (DPIRD) and the Grains Research and Development Corporation (GRDC).

Key messages:

• Existing soil amelioration options can generate substantial yield responses. However, further yield gain is possible with further improvement in soil amelioration strategies.

• Mapping of soil constraints and potential yield gaps using the water use efficiency achieved from a pilot reengineering experiment has identified a significant yield gap attributed …


Cascading Effects Of Cover Crops On The Subsequent Cash Crop Defense Against The Polyphagous Herbivore Fall Armyworm (Spodoptera Frugiperda), Adegboyega Fajemisin, Alexis Racelis, Rupesh R. Kariyat Feb 2023

Cascading Effects Of Cover Crops On The Subsequent Cash Crop Defense Against The Polyphagous Herbivore Fall Armyworm (Spodoptera Frugiperda), Adegboyega Fajemisin, Alexis Racelis, Rupesh R. Kariyat

School of Earth, Environmental, & Marine Sciences Faculty Publications

Simple Summary

Although studies have started to show that the effects of cover crops can translate into the cash cropping season, there is little information on the cascading effects of cover crops on the subsequent cash crop defenses, especially against polyphagous herbivores. To bridge this information gap, we conducted a field and laboratory study to investigate the cascading effects of different cover crop species on the subsequent cash crop defense against the polyphagous herbivore fall armyworm (Spodoptera frugiperda) across three fields in the Lower Rio Grande Valley in south Texas. Our field and laboratory results revealed that cover crop treatments …


College Of Natural Sciences Newsletter, November 2022 - January 2023, College Of Natural Sciences Feb 2023

College Of Natural Sciences Newsletter, November 2022 - January 2023, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volme 3, Issue 7

Page 1 Dean's Message
Page 2 Awards & Recognition
Page 3 Sioux Falls Middle School Visit
Page 4 Bio-Micro Day of Scholars
Page 5 GIS Day at USGS EROS
Page 6 Indigenous People's Festival, & Visiting Jack's Imagination Lab
Page 7 Media Coverage of CNS, & Research Highlights from Geography & Geospatial Sciences
Page 8 Media Coverage of CNS. cont.
Page 9 Open PRAIRIE Data
Page 10 Recent Publications from CNS
Page 11 Recent Publications from CNS. cont.
Page 12 CNS Holiday Snapshots
Page 13 & 14 Fall 2022 Dean's List
Page 12-14 Fall 2022 Outreach …


Evaluation Of Polyacrylamide (Pam) Effects On Irrigation Efficiency, Soil Conservation, And Water Quality In Midsouth Cotton Production, Brittany D. Barnes Feb 2023

Evaluation Of Polyacrylamide (Pam) Effects On Irrigation Efficiency, Soil Conservation, And Water Quality In Midsouth Cotton Production, Brittany D. Barnes

Student Theses and Dissertations

The polymer, polyacrylamide (PAM), is a high molecular weight, chemical anionic polymer that is prescribed and used for irrigation improvement in row crops primarily in the United States. A field research study was conducted in 2014, 2015 and 2016 in Northeast Arkansas to evaluate how addition of PAM in furrow irrigation affected soil erosion, water infiltration, movement of nutrients and sediments, and crop yields in cotton (Gossypium hirsutum). Overall results from the study were mixed. Sediment loss was similar among treatments. Irrigation advancement rates were not significantly different. No differences in crop yield were observed associated with PAM. Differences in …


Evaluation Of Woodchip Bioditch Reactors As A Nutrient Reduction Conservation Strategy, Geoffrey K. Payne Feb 2023

Evaluation Of Woodchip Bioditch Reactors As A Nutrient Reduction Conservation Strategy, Geoffrey K. Payne

Student Theses and Dissertations

Continued increases in nitrogen and phosphorus loads in waterways cause problems with water quality, impacting human health, the economy, and the environment. To reach nutrient load reduction targets, innovative conservation strategies should be evaluated. This study aimed to assess (1) the potential of using woodchip bioditch reactors for the mitigation of nitrate (NO3-) and soluble reactive phosphorus (SRP) in agricultural waterways; (2) the influence of orientation of the bioditch reactor to flow direction on NO3- and SRP concentrations and loads; and (3) the impact that differing wet/dry cycles have on NO3- and SRP concentrations and loads when bioditch reactors are …


Picture Gorge Basalt: Internal Stratigraphy, Eruptive Patterns, And Its Importance For Understanding Columbia River Basalt Group Magmatism, Emily Bogdan Cahoon, Martin J. Streck, Anthony A.P. Koppers Feb 2023

Picture Gorge Basalt: Internal Stratigraphy, Eruptive Patterns, And Its Importance For Understanding Columbia River Basalt Group Magmatism, Emily Bogdan Cahoon, Martin J. Streck, Anthony A.P. Koppers

Geology Faculty Publications and Presentations

The Picture Gorge Basalt (PGB) of the Columbia River Basalt Group (CRBG) has been previously thought to be limited in its eruptive volume (<3000 >km3) and thought to not extend far from its type locality. At present, PGB represents only 1.1 vol% of the CRBG with a relatively limited spatial distribution of ~10,000 km2. New age data illustrate that the PGB is the earliest and longest eruptive unit compared to other main-phase CRBG formations and that some dated basaltic flows reach far (~100 km) beyond the previously mapped extent. This study focuses on extensive outcrops of …


Digital Atlas Of The Vascular Plants Of Utah, R. Douglas Ramsey, Leila M. Shultz, Wanda Lindquist, Chris Garrard, Mindy Wheeler Feb 2023

Digital Atlas Of The Vascular Plants Of Utah, R. Douglas Ramsey, Leila M. Shultz, Wanda Lindquist, Chris Garrard, Mindy Wheeler

Browse all Datasets

Locations of 74,755 vascular plant vouchers representing 2,425 species were digitized into a spatial database from the Atlas of the Vascular Plants of Utah (Albee et al. 1988). Source maps consisted of 1:6,000,000-scale shaded relief maps of Utah with points representing collection locations by species. Location points, representing 1 or more specimens, were transposed onto these maps from the approximately 400,000 herbarium records of 3 major universities and federal land management agencies.


Important Role Of Precipitation In Controlling A More Uniform Spring Phenology In The Qinba Mountains, China, Jianhao Li, Jingyun Guan, Wangqiang Han, Ruikang Tian, Binbin Lu, Danlin Yu, Jianghua Zheng Feb 2023

Important Role Of Precipitation In Controlling A More Uniform Spring Phenology In The Qinba Mountains, China, Jianhao Li, Jingyun Guan, Wangqiang Han, Ruikang Tian, Binbin Lu, Danlin Yu, Jianghua Zheng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Under global warming, the gradual pattern of spring phenology along elevation gradients (EG) has significantly changed. However, current knowledge on the phenomenon of a more uniform spring phenology is mainly focused on the effect of temperature and neglected precipitation. This study aimed to determine whether a more uniform spring phenology occurs along EG in the Qinba Mountains (QB) and explore the effect of precipitation on this pattern. We used Savitzky-Golay (S-G) filtering to extract the start of season (SOS) of the forest from the MODIS Enhanced Vegetation Index (EVI) during 2001-2018 and determined the main drivers of the SOS patterns …


Coral Gardens Reef, Belize: An Acropora Spp. Refugium Under Threat In A Warming World, Lisa Greer, H. Allen Curran, Karl Wirth, Robert Humston, Ginny Johnson, Lauren Mcmanus, Candice Stefanic, Tara Clark, Halard Lescinsky, Kirah Forman-Castillo Feb 2023

Coral Gardens Reef, Belize: An Acropora Spp. Refugium Under Threat In A Warming World, Lisa Greer, H. Allen Curran, Karl Wirth, Robert Humston, Ginny Johnson, Lauren Mcmanus, Candice Stefanic, Tara Clark, Halard Lescinsky, Kirah Forman-Castillo

Geosciences: Faculty Publications

Live coral cover has declined precipitously on Caribbean reefs in recent decades. Acropora cervicornis coral has been particularly decimated, and few Western Atlantic Acropora spp. refugia remain. Coral Gardens, Belize, was identified in 2020 as a long-term refugium for this species. This study assesses changes in live A. cervicornis coral abundance over time at Coral Gardens to monitor the stability of A. cervicornis corals, and to explore potential threats to this important refugium. Live coral cover was documented annually from 2012– 2019 along five permanent transects. In situ sea-surface temperature data were collected at Coral Gardens throughout the study period …


A Critical Review On Water Overconsumption In Lignocellulosic Biomass Pretreatment For Ethanol Production Through Enzymic Hydrolysis And Fermentation, Jikai Zhao, Juhee Lee, Donghai Wang Feb 2023

A Critical Review On Water Overconsumption In Lignocellulosic Biomass Pretreatment For Ethanol Production Through Enzymic Hydrolysis And Fermentation, Jikai Zhao, Juhee Lee, Donghai Wang

School of Earth, Environmental, & Marine Sciences Faculty Publications

Global demand for renewable and sustainable energy fostered the considerable development of biomass-to-ethanol valorization strategies. Thermochemical pretreatment methods have been proposed to render biomass more amenable to enzymatic and microbial digestion. However, the efforts have not led to its industrial-scale worldwide realization. One of the obstacles to commercialization could be related to water overconsumption, as excessive water washing of the pretreated slurry is often performed to remove inhibitory compounds and residual chemicals after biomass pretreatment. Only increasing solid loading for biomass pretreatment results in ineffective pretreatment performance, more inhibitors formation, and high viscosity, which in turn necessitates the water washing …


Metal Contents In House Geckos (Squamata: Gekkonidae) From Industrial And Urban Areas Of Southern Tamaulipas, Mexico And Western Andalucía, Spain, May Reflect Airborne Metal Pollution, Luisiana Morales-Zamudio, Alejandro Fierro-Cabo, Md. Saydur Rahman, Miguel Antonio Dominguez-Crespo Feb 2023

Metal Contents In House Geckos (Squamata: Gekkonidae) From Industrial And Urban Areas Of Southern Tamaulipas, Mexico And Western Andalucía, Spain, May Reflect Airborne Metal Pollution, Luisiana Morales-Zamudio, Alejandro Fierro-Cabo, Md. Saydur Rahman, Miguel Antonio Dominguez-Crespo

School of Earth, Environmental, & Marine Sciences Faculty Publications

House geckos share living quarters with humans in the tropical and subtropical regions inhabited by these reptiles. Gecko behavior, biological traits, continuous exposure to suspended particulate matter 0 µm in diameter (PM10) and dust, as well as status as exotic species, motivated the choice of these species to examine environmental exposure to ambient air pollutants, in particular metals, and subsequent accumulation in these organisms. One part of the study was conducted in Tamaulipas (Mexico) where Hemydactylus frenatus is abundant in urban and industrial environments, the other part was conducted in Andalucia (Spain) where Tarentola mauritanica is found in similar environments. …


Higher Concentrations Of Microplastics In Runoff From Biosolid-Amended Croplands Than Manure-Amended Croplands, Nasrin Naderi Beni, Shahab Karimifard, John Gilley, Tiffany L. Messer, Amy Schmidt, Shannon Bartelt-Hunt Feb 2023

Higher Concentrations Of Microplastics In Runoff From Biosolid-Amended Croplands Than Manure-Amended Croplands, Nasrin Naderi Beni, Shahab Karimifard, John Gilley, Tiffany L. Messer, Amy Schmidt, Shannon Bartelt-Hunt

UK CARES Faculty Publications

Land-applied municipal biosolids, produced from municipal wastewater treatment sludge, contributes to microplastics contamination in agroecosystems. The impacts of biosolids on microplastic concentrations in agricultural soil have been previously investigated, however, the potential for microplastics transport from biosolid-amended croplands has not been previously quantified. In this study, manure and biosolids were applied to field plots, runoff was collected following natural precipitation events and the potential of bacterial biofilm to grow on different microplastic morphologies was investigated. Higher concentrations of microplastics were detected in runoff from plots with land-applied biosolid in comparison with manure-amended and control plots. Fibers and fragments were the …


Pore Connectivity Influences Mass Transport In Natural Rocks: Pore Structure, Gas Diffusion And Batch Sorption Studies, Qinhong Hu Feb 2023

Pore Connectivity Influences Mass Transport In Natural Rocks: Pore Structure, Gas Diffusion And Batch Sorption Studies, Qinhong Hu

Earth & Environmental Sciences Datasets - Archive

The Excel file contains supplementary dataset, in various sheets, for a manuscript entitled "Pore connectivity influences mass transport in natural rocks: Pore structure, gas diffusion and batch sorption studies" The Word file of "Data Dictonary" briefly explained the data in each sheet of the Excel file, from different measurements as detailed in the manuscript. Authors: Xiaoqing Yuan, Qinhong Hu ([email protected]), Xiang Lin, Chen Zhao, Qiming Wang, Yukio Tachi, Yuta Fukatsu, Shoichiro Hamamoto, Marja Siitari-Kauppia, and Xiaodong Li


Dynamic Mass Loss From Greenland's Marine-Terminating Peripheral Glaciers (1985–2018), Katherine E. Bollen, Ellyn M. Enderlin, Rebecca Muhlheim Feb 2023

Dynamic Mass Loss From Greenland's Marine-Terminating Peripheral Glaciers (1985–2018), Katherine E. Bollen, Ellyn M. Enderlin, Rebecca Muhlheim

Geosciences Faculty Publications and Presentations

Global glacier mass balance decreased rapidly over the last two decades, exceeding mass loss from the Greenland and Antarctic Ice Sheets. In Greenland, peripheral glaciers and ice caps (GICs) cover only ~5% of Greenland's area but contributed ~20% of the island's ice mass loss between 2000 and 2018. Although Greenland GIC mass loss due to surface meltwater runoff has been estimated using atmospheric models, mass lost to changes in ice discharge into oceans (i.e., dynamic mass loss) remains unquantified. We use the flux gate method to estimate discharge from Greenland's 585 marine-terminating peripheral glaciers between 1985 and 2018, and compute …


Lidar And Deep Learning Reveal Forest Structural Controls On Snowpack, Ahmad Hojatimalekshah, Joel Gongora, Josh Enterkine, Nancy F. Glenn, T. Trevor Caughlin, Hans-Peter Marshall, Christopher A. Hiemstra Feb 2023

Lidar And Deep Learning Reveal Forest Structural Controls On Snowpack, Ahmad Hojatimalekshah, Joel Gongora, Josh Enterkine, Nancy F. Glenn, T. Trevor Caughlin, Hans-Peter Marshall, Christopher A. Hiemstra

Geosciences Faculty Publications and Presentations

Forest structure has a strong relationship with abiotic components of the environment. For example, canopy morphology controls snow depth through interception and modifies incoming thermal radiation. In turn, snow water availability affects forest growth, carbon sequestration, and nutrient cycling. We investigated how structural diversity and topography affect snow depth patterns across scales. The study site, Grand Mesa, Colorado, is representative of many areas worldwide where declining snowpack and its consequences for forest ecosystems are increasingly an environmental concern. On the basis of a convolution neural network model (R2 of 0.64; root mean squared error of 0.13 m), we …


The Use And Challenges Of Spatial Data In Archaeology, Carla Klehm Feb 2023

The Use And Challenges Of Spatial Data In Archaeology, Carla Klehm

Anthropology Faculty Publications and Presentations

Spatial data, under the broader umbrella of digital data, is becoming increasingly integral to all stages of archaeological research design and dissemination. As archaeologists lean toward reuse and interoperability, with ethics on their minds, how to treat spatial data is of particular importance. This is because of the complexities involved at every life-cycle stage, from collection to publication, including black box issues that may be taken for granted, and because the size of spatial data can lead to archiving difficulties. Here, the “DIY” momentum of increasingly accessible spatial methods such as photogrammetry and handheld lidar is examined alongside forthcoming changes …


Seismic Azimuthal Anisotropy Beneath A Fast Moving Ancient Continent: Constraints From Shear Wave Splitting Analysis In Australia, Kailun Ba, Stephen S. Gao, Jianguo Song, Kelly H. Liu Feb 2023

Seismic Azimuthal Anisotropy Beneath A Fast Moving Ancient Continent: Constraints From Shear Wave Splitting Analysis In Australia, Kailun Ba, Stephen S. Gao, Jianguo Song, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Seismic Azimuthal Anisotropy Beneath Australia is Investigated using Splitting of the Teleseismic PKS, SKKS, and SKS Phases to Delineate Asthenospheric Flow and Lithospheric Deformation Beneath One of the Oldest and Fast-Moving Continents on Earth. in Total 511 Pairs of High-Quality Splitting Parameters Were Observed at 116 Seismic Stations. Unlike Other Stable Continental Areas in Africa, East Asia, and North America, Where Spatially Consistent Splitting Parameters Dominate, the Fast Orientations and Splitting Times Observed in Australia Show a Complex Pattern, with a Slightly Smaller Than Normal Average Splitting Time of 0.85 ± 0.33 S. on the North Australian Craton, the Fast …


Wayne E. Sabbe Arkansas Soil Fertility Studies 2022, Nathan A. Slaton, Mike Daniels Feb 2023

Wayne E. Sabbe Arkansas Soil Fertility Studies 2022, Nathan A. Slaton, Mike Daniels

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.


Impacts Of Tectonic Subsidence On Basin Depth And Delta Lobe Building, Tian Y. Dong, Jeffrey A. Nittrouer, Brandee Carlson, Brandon Mcelroy, Elena Il’Icheva, Maksim Pavlov, Hongbo Ma Feb 2023

Impacts Of Tectonic Subsidence On Basin Depth And Delta Lobe Building, Tian Y. Dong, Jeffrey A. Nittrouer, Brandee Carlson, Brandon Mcelroy, Elena Il’Icheva, Maksim Pavlov, Hongbo Ma

School of Earth, Environmental, & Marine Sciences Faculty Publications

Channel avulsions on river deltas are the primary means to distribute sediment and build land at the coastline. Many studies have detailed how avulsions generate delta lobes, whereby multiple lobes amalgamate to form a fan-shaped deposit. These studies often assume steady subsidence and uniform basin depth. In nature, however, lobe building is disrupted by variable subsidence, and progradation of lobes into basins with variable depth: conditions that are prevalent for tectonically active areas. Herein, we explore sediment dispersal and deposition patterns across scales using measurements of delta and basin morphology compiled from field surveys and remote sensing, collected over 150 …


A Systematic Design Approach For Bulk Gel Treatments Based On Gel Volume-Concentration Ratio In Field Projects, Munqith Aldhaheri, Mingzhen Wei, Baojun Bai Feb 2023

A Systematic Design Approach For Bulk Gel Treatments Based On Gel Volume-Concentration Ratio In Field Projects, Munqith Aldhaheri, Mingzhen Wei, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Controlling excessive water production in mature oil fields has always been a desired objective of the oil and gas industry. This objective calls for planning of more effective water-control gel treatments with optimized designs to obtain more attractive outcomes. Unfortunately, planning such effective treatments remains a dilemma for reservoir engineers due to the lack of methodical design tools in the industry. This paper presents a novel systematic design approach for polyacrylamide-Based bulk gel treatments by classifying their field projects according to the gel volume-concentration ratio (VCR) into three design types. in terms of one another, the approach estimates either the …