The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, 2018 The University of Western Ontario
The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, Arya Bina
Electronic Thesis and Dissertation Repository
Currently, Mars appears to be in a ‘frozen’ and ‘dry’ state, with the clear majority of the planet’s surface maintaining year-round sub-zero temperatures. However, the discovery of features consistent with landforms found in periglacial environments on Earth, suggests a climate history for Mars that may have involved freeze and thaw cycles. Such landforms include hummocky, polygonised, scalloped, and pitted terrains, as well as ice-rich deposits and gullies, along the mid- to high-latitude bands, typically with no lower than 20o N/S. The detection of near-surface and surface ice via the Phoenix lander, excavation of ice via recent impact cratering ...
Development And Application Of The Heat Pulse Method For Soil Physical Measurements, 2018 Northwest A&F University
Development And Application Of The Heat Pulse Method For Soil Physical Measurements, Hailong He, Miles F. Dyck, Robert Horton, Tusheng Ren, Keith L. Bristow, Jialong Lv, Bingcheng Si
Accurate and continuous measurements of soil thermal and hydraulic propertiesare required for environmental, Earth and planetary science, and engineering applications, but they are not practicallyobtained by steady-state methods. The heat pulse (HP) method is a transient method for determinationof soil thermal properties and a wide range of other physical properties in laboratory and field conditions. The HP method is based on the line-heat source solution of the radial heat flow equation. This literature review begins with a discussion of the evolution of the HP method and related applications, followed by the principal theories, data interpretation methods and their differences. Important ...
Nitrogen Cycling During A Period Of Environmental Change, 2018 University of Maine
Nitrogen Cycling During A Period Of Environmental Change, Kaizad Patel
Electronic Theses and Dissertations
Natural and anthropogenic disturbances have altered the N cycle on the regional to global scale. Although numerous studies have examined the effects of chronic atmospheric N deposition on ecosystem processes, less is known about intra-annual variability of these processes, or how these responses might be altered under conditions of changing climate. The work described in this dissertation focuses on the effects of a changing chemical and physical climate, particularly terrestrial N processes (a) during Maine’s changing winters, and (b) in response to chronic elevated N additions.
Subnivean winter soil processes were examined at the Dwight B. DeMerritt Forest (DBDF ...
The Effect Of Two Different Harvesting Methods On The Yield Of 'Topbunch' And 'Hi-Crop' Collards (Brassica Oleracea (L)) When Grown In A Wiregrass Tunnel House, Veronica E. Walton, Raymon Shange, Melissa Johnson, Edward Sparks, Victor Khan, James E. Currington, Ramble Ankumah, Nathaniel Ellison, George X. Hunter Jr., Jeffery L. Moore
Professional Agricultural Workers Journal
A study was conducted to determine if 100% or 50% harvesting of collard leaves was a suitable recommendation for Tunnel House producers. The experiment was conducted as a split-split plot design with varieties as the main plots, harvesting 100% or 50% of leaves as the sub-plots, and days after transplanting as the subplots. All treatments were replicated three times, drip irrigated, and fertilized according to soil test recommendations. The results showed significant interactions between varieties and method of harvest, for leaf numbers and weight. Conversely, the varieties showed significant differences for yield but not leaf numbers. Both varieties showed significant ...
The Evaluation Of Two Different Harvesting 'Topbunch' And 'Hi-Crop' Collards (Brassica Oleracea (L)) Leaves From Plants Grown In A Wiregrass Tunnel House, Edward Sparks, Raymon Shange, Jacquelyn Jackson, Victor Khan, James E. Currington, Ramble Ankumah, Nathaniel Ellison, George X. Hunter Jr., Jeffery L. Moore
Professional Agricultural Workers Journal
A study was conducted to determine if a 100% or 50% harvest intensity of ‘Topbunch’ collards leaves could be a recommended practice for Tunnel House producers. The experiment was conducted as a split-plot design with harvest dates as main plots, and harvesting intensity of 100% or 50% of leaves as sub-plots. All treatments were replicated three times, drip irrigated, and fertilized according to soil test recommendations. The results showed significant interactions between harvest methods and dates for number and weight of leaves harvested. There were also significant differences for the weight of leaves harvested and numbers. The leaf recovery rates ...
Remote Sensing Using I-Band And S-Band Signals Of Opportunity, 2018 Purdue University
Remote Sensing Using I-Band And S-Band Signals Of Opportunity, Kadir Efecik, Benjamin R. Nold, James L. Garrison
The Summer Undergraduate Research Fellowship (SURF) Symposium
Measurement of soil moisture, especially the root zone soil moisture, is important in agriculture, meteorology, and hydrology. Root zone soil moisture is concerned with the first meter down the soil. Active and passive remote sensing methods used today utilizing L-band(1-2GHz) are physically limited to a sensing depth of about 5 cm or less. To remotely sense the soil moisture in the deeper parts of the soil, the frequency should be lowered. Lower frequencies cannot be used in active spaceborne instruments because of their need for larger antennas, radio frequency interference (RFI), and frequency spectrum allocations. Ground-based passive remote sensing ...
Spatial Response Of Near-Surface Soil Water Contents To Newly Imposed Soil Management, 2018 North Dakota State University--Fargo
Spatial Response Of Near-Surface Soil Water Contents To Newly Imposed Soil Management, Aaron L. M. Daigh, Upasana Ghosh, Jodi Dejong-Hughes, Robert Horton
Near-surface soil water content (SWC) and its spatial patterns are important for landscape hydrological responses to precipitation as well as our ability to remotely sense and model such responses. Our objective was to measure and evaluate near-surface SWC semivariograms of agricultural fields with newly imposed (i.e., <2 yr) side-by-side soil and residue management practices (i.e., reduced tillage systems and cover crops) in the midwestern United States. Range parameters were consistently smaller when cover crops were planted (20–25 m less) and tillage area and/or intensity was reduced (12–27 m less) compared with no cover crop and chisel plowing, respectively, except in a clayey Vertisol. Nugget and sill parameters did not have consistent trends across soil management practices or sites. These data, although brief and preliminary in scope, provide clear proof of concept that spatial pattern shifts can be clearly detected in newly imposed soil-management systems even though differences in SWC means are not always evident.
Geophysical Assessment Of Subsurface Soil Conditions Using Capacitively Coupled Resistivity, 2018 University of Arkansas, Fayetteville
Geophysical Assessment Of Subsurface Soil Conditions Using Capacitively Coupled Resistivity, Folaseye Coker
Theses and Dissertations
The purpose of this research is to explore the applicability of Capacitively-Coupled Resistivity (CCR) as an improvement on traditional drilling and sampling methods for subsurface soil investigations. The CCR method could be used to identify critical locations for drilling and sampling such as expansive clay layers and anomalies (sinkholes, unknown landfills, etc.) rather than uniformly sampling across a site. CCR surveys were performed at Alpena, Arkansas along a highway expansion project changing US 62 from a two lane to four lane highway, and at Alton, Illinois along the Mel Price Levee, a 5.2 mile levee along a portion of ...
Flow Regime Influences On Stream And Riparian Soil Carbon Dynamics In The Ozark Highlands And Boston Mountains Of Arkansas, 2018 University of Arkansas, Fayetteville
Flow Regime Influences On Stream And Riparian Soil Carbon Dynamics In The Ozark Highlands And Boston Mountains Of Arkansas, Allyn Dodd
Theses and Dissertations
The natural flow regime exerts primacy over lotic ecosystem patterns and processes. However, little work has examined the influence of flow regime on instream and riparian carbon (C) dynamics in minimally-impacted, temperate forested systems. To date, most research efforts have focused on characterizing C movement and transformations across biomes and land use categories; however, flow regime represents an overlooked, finer level of detail that may drive differences in ecosystem function. My dissertation objective was to measure C fixation and movement within and across multiple environmental spheres (e.g. within stream channels, between stream surfaces and the atmosphere, and from riparian ...
Proposed Astm Standard For The Stokoe-Type Resonant Column Torsional Shear Device, 2018 University of Arkansas, Fayetteville
Proposed Astm Standard For The Stokoe-Type Resonant Column Torsional Shear Device, Anh Tuan Tran
Theses and Dissertations
Resonant Column Torsional Shear (RCTS) testing has become one of the most commonly used methods for determining laboratory soil stiffness and soil damping. The RCTS test has been accepted and is commonly utilized during the permitting of new nuclear facilities. However, there is still no available public standard for performing RCTS tests using the Stokoe-type device. Therefore, an ASTM standard for calibration and performance of RCTS tests using the Stokoe-type RCTS device is presented herein. Data collected using the Stokoe-type RCTS devices at the University of Arkansas (UofA) and at the Norwegian Geotechnical Institute (NGI) also aided in the development ...
Approaches For Estimating Soil Water Retention Curves At Various Bulk Densities With The Extended Van Genuchten Model, 2018 North Carolina State University
Approaches For Estimating Soil Water Retention Curves At Various Bulk Densities With The Extended Van Genuchten Model, Zhengchao Tian, Weida Gao, Dilia Kool, Tusheng Ren, Robert Horton, Joshua L. Heitman
Soil bulk density (ρb) variations influence soil hydraulic properties, such as the water retention curve (WRC), but they are usually ignored in soil-water simulation models. We extend the van Genuchten WRC model parameters to account for ρb variations using a series of empirical expressions. WRC measurements made on eight soils with various ρb and textures are used to calibrate these ρb–related empirical equations. Accordingly, two approaches are developed to estimate WRCs of soils at various ρb. Another eight soils with a wide range of ρb and textures are used to evaluate the accuracy of the new approaches. Approach 1 ...
Summary Of Advances In The Heat-Pulse Technique: Improvements In Measuring Soil Thermal Properties, 2018 China Agricultural University
Summary Of Advances In The Heat-Pulse Technique: Improvements In Measuring Soil Thermal Properties, Minmin Wen, Gang Liu, Robert Horton, Yili Lu, Tusheng Ren
This essay provides a summary of “Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties” recently appearing in Methods of Soil Analysis. Series.
Using Geological Facies To Estimate Chromate Sorption To Soils, 2018 Delaware State University
Using Geological Facies To Estimate Chromate Sorption To Soils, Victoria Smith, Daja Scurlock, Chauntilena Butler, Eddie Hollins, Kennedy Smith, Tim Spearman, Christina Fulghum, John Dickson, Daniel I. Kaplan, Miles Denham, Garriet Smith
Journal of the South Carolina Academy of Science
Quantifying the extent to which contaminant metals bind to subsurface soils is important for risk assessment, the tendency for a contaminant to migrate, and developing environmental remediation strategies. Unfortunately, subsurface soils vary widely in their composition, which in turn affect their tendency to bind metals. The hypothesis of this study was predicated on how a better understanding of geological facies would reduce uncertainty associated with predicting contaminant metal sorption. Facies are layers of sediment deposited in the subsurface due to similar depositional conditions, including energy of an overlying waterway. As such, facies are expected to have similar assemblages of minerals ...
Distribution Of Classified Soils In South-West Western Australia, 2018 Department of Agriculture and Food Western Australia
Distribution Of Classified Soils In South-West Western Australia, Dennis Van Gool, Angela Stuart-Street, Peter Tille
Resource management technical reports
This report provides areas, locations and properties of the main soil classifications identified in south-west Western Australia using current conventional soil map data. It is a reference point for classified soils in the south-west. It provides a way of communicating how soil properties or productivity are likely to relate to soils with similar classifications found elsewhere so that soil research or knowledge can be effectively shared around the state and across Australia.
This is a high-level summary of the relationships between the main soil classifications currently used in Western Australia. These are: • Western Australian Soil Groups, WASG (Schoknecht & Pathan 2013 ...
A Broad Spectrum Racemase In Pseudomonas Putida Kt2440 Plays A Key Role In Amino Acid Catabolism, 2018 University of California - San Francisco
A Broad Spectrum Racemase In Pseudomonas Putida Kt2440 Plays A Key Role In Amino Acid Catabolism, Atanas D. Radkov, Luke A. Moe
Plant and Soil Sciences Faculty Publications
The broad-spectrum amino acid racemase (Alr) of Pseudomonas putida KT2440 preferentially interconverts the L- and D-stereoisomers of Lys and Arg. Despite conservation of broad-spectrum racemases among bacteria, little is known regarding their physiological role. Here we explore potential functional roles for Alr in P. putida KT2440. We demonstrate through cellular fractionation that Alr enzymatic activity is found in the periplasm, consistent with its putative periplasm targeting sequence. Specific activity of Alr is highest during exponential growth, and this activity corresponds with an increased accumulation of D-Lys in the growth medium. An alr gene knockout strain (Δalr) was generated and ...
Soil Conservation Efforts Affecting And Implementations To Help Tree Growth In Iceland, 2018 Embry-Riddle Aeronautical University
Soil Conservation Efforts Affecting And Implementations To Help Tree Growth In Iceland, Justin Lawlor
The purpose of this research was to understand and project the opinions of the public in Iceland on soil conservation and current efforts. The issue of soil erosion dates back to settlement around 1,100 years ago. The loss of vegetation from deforestation and grazing exposes the land to the effects of wind, water, and other devastating elements, leading it to erode away. The Soil Conservation Service of Iceland (SCSI) was developed to combat this issue over 100 years ago with efforts including planting trees, promoting safe farming practices, and replenishing the land. Interviews were conducted with various individuals, including ...
Column Tests Of Nitrate Breakthrough Behavior In Subsurface Sediments To Understand Transport In The Root-Zone, 2018 California Polytechnic State University, San Luis Obispo
Column Tests Of Nitrate Breakthrough Behavior In Subsurface Sediments To Understand Transport In The Root-Zone, Rebecca Sally Haworth, Emma Rose Goodwin
Natural Resources Management and Environmental Sciences
No abstract provided.
A Quantitative Analysis Of The Effects Of Urbanization, Mesophication And Prescribed Burns On Oak Woodlands In The Chicago Metropolitan Area, 2018 Augustana College, Rock Island Illinois
A Quantitative Analysis Of The Effects Of Urbanization, Mesophication And Prescribed Burns On Oak Woodlands In The Chicago Metropolitan Area, Chad Populorum
Celebration of Learning
Urban expansion has had devastating impacts on forest ecosystems, especially within the past century. Human attempts to dominate nature have diminished natural disturbance regimes, which have maintained the biodiversity and historic composition of these ecosystems. Fires have been a prominent force in maintaining the structure of oak, hickory and other heliophytic (sun loving and fire-adapted) forest systems. Human induced fire suppression has led to mesophication across North America. Mesophication is the transition from drier conditions with open canopies to wetter conditions with closed canopies. These new conditions decrease the survival rates of these important species and begin to favor mesophytic ...
Results Of Test-Hole Drilling For Observation Well Planning In The Lower Loup Natural Resources District, Spring 2017, 2018 University of Nebraska - Lincoln
Results Of Test-Hole Drilling For Observation Well Planning In The Lower Loup Natural Resources District, Spring 2017, Douglas R. Hallum P.G., Sue Olafsen Lackey, Steven S. Sibray
Conservation and Survey Division
The High Plains Aquifer underlies much of Nebraska. It is the primary source of groundwater within the Lower Loup Natural Resources District (LLNRD) of central Nebraska. Water derived from the aquifer is an important natural resource for the area and supplies water for recreation, wildlife and agriculture, as well as domestic, municipal, and industrial uses. Falling spring water levels measured in existing observation and irrigation wells have raised concerns about possible changes in water availability, groundwater-surface water relationships and water quality in the area, prompting the LLNRD to propose test holes and the collection of additional groundwater data in the ...
Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender
Student Theses 2015-Present
This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim ...