Open Access. Powered by Scholars. Published by Universities.®

Civil and Environmental Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 9871 - 9900 of 39819

Full-Text Articles in Civil and Environmental Engineering

The Effects Of Surface-Water Flow On The Quality Of Groundwater And Surface-Water Systems, Quanghee Yi Jun 2020

The Effects Of Surface-Water Flow On The Quality Of Groundwater And Surface-Water Systems, Quanghee Yi

USF Tampa Graduate Theses and Dissertations

My research has focused on the effects of surface-water flow on the quality of groundwater and surfacewater systems. For the first part of my research (Chapter 2 ), I s tudied the effects of s urface flow system changes in the water-conservation areas and canals in southeast Florida on the quality of groundwater in the surficial aquifer system.

For the second part of my research, by developing analytical models using the superposition method, I investigated the effects of bidirectional surface-water flow on the conservative contaminant concentrations (Chapter 4) and mean residence time (Chapter 5) in streams and rivers as well …


Bio-Electrochemical Denitrification Systems And Applications For Nitrogen Removal In On-Site Wastewater Treatment, Kamal Ziad Taha Jun 2020

Bio-Electrochemical Denitrification Systems And Applications For Nitrogen Removal In On-Site Wastewater Treatment, Kamal Ziad Taha

USF Tampa Graduate Theses and Dissertations

Denitrification experiments using biological cathodes (biocathodes) were conducted in three separate experiments. The first experiment was to observe whether the rate of denitrification in biocathodes could be increased with added ammonium at mass (mg/L) ratios of 0.100 (2.5/25), 0.05 (1.25/25), 0.0250 (0.625/25), and 0.0125 (0.3125/25) (parts ammonium to nitrate (NH4+-N/ NO3--N). The purpose of the ammonium present was to provide the microorganisms a starting nitrogen source for assimilation to biomass which, in theory, would encourage the removal of nitrate through dissimilatory denitrification. As mixed cultures were used, ratios tested were based on simplifying future operation of scaled-up biocathodes applied to …


Structural And Agricultural Value At Risk In Florida From Flooding During Hurricane Irma, Alexander J. Miller Jun 2020

Structural And Agricultural Value At Risk In Florida From Flooding During Hurricane Irma, Alexander J. Miller

USF Tampa Graduate Theses and Dissertations

Flooding is the most costly type of natural disaster, as well as the most frequent. To provide risk-based flood insurance, providers such as FEMA must be able to accurately determine an asset’s risk of flooding. Additionally, after a flooding event, providers need to quickly determine the direct damages that occurred to verify insurance claims and provide assistance to the affected communities. Many current approaches to flood risk and flood damage estimation involve the use of data or statistical extrapolation that can add various sources of uncertainty into the final damage estimate. In order to reduce uncertainties in flood risk analyses, …


Exploiting Earth Observation Data To Impute Groundwater Level Measurements With An Extreme Learning Machine, Steven Evans, Gustavious P. Williams, Norman L. Jones, Daniel P. Ames, E. James Nelson Jun 2020

Exploiting Earth Observation Data To Impute Groundwater Level Measurements With An Extreme Learning Machine, Steven Evans, Gustavious P. Williams, Norman L. Jones, Daniel P. Ames, E. James Nelson

Faculty Publications

Groundwater resources are expensive to develop and use; they are difficult to monitor and data collected from monitoring wells are often sporadic, often only available at irregular, infrequent, or brief intervals. Groundwater managers require an accurate understanding of historic groundwater storage trends to effectively manage groundwater resources, however, most if not all well records contain periods of missing data. To understand long-term trends, these missing data need to be imputed before trend analysis. We present a method to impute missing data at single wells, by exploiting data generated from Earth observations that are available globally. We use two soil moisture …


Water Quality And Sustainability Assessment Of Rural Water Systems In The Comarca Ngäbe-Buglé, Panama, Corbyn Cools Jun 2020

Water Quality And Sustainability Assessment Of Rural Water Systems In The Comarca Ngäbe-Buglé, Panama, Corbyn Cools

USF Tampa Graduate Theses and Dissertations

Over the last four decades significant progress has been made on providing people access to improved drinking water. The Joint Monitoring Program (JMP) estimates that 6.7 billion people have access to at least basic drinking water services. In spite of this great achievement 785 million people still lack even basic services and eighty percent of which live in rural areas. To further complicate matters, those with access to services experience interruptions or non-functionality for handpumps and piped system long before the intended design life of the system. In the Comarca Ngäbe-Buglé province in Panama there is very little information on …


The Effect Of The Top Soil Layer On Moisture And Evaporation Dynamics, Zhen Li, Jan Vanderborght, Kathleen M. Smits Jun 2020

The Effect Of The Top Soil Layer On Moisture And Evaporation Dynamics, Zhen Li, Jan Vanderborght, Kathleen M. Smits

Civil Engineering Faculty Publications - Archive

Understanding the effect of the top soil layer on surface evaporation and water distribution is critical to modeling hydrological systems. However, the dependency of near-surface soil moisture and fluxes on layering characteristics remains unclear. To address this uncertainty, we investigate how the arrangement of soil horizons affects the evaporation and soil moisture, specifically, the near-surface soil moisture, through the combination of numerical simulations and evaporation experiments. The characteristics of fluxes and moisture from different soil profiles are then used to understand the soil layering conditions. Results show that the top soil layer can significantly affect the evolution of soil moisture …


Development Of An Organic Processor Assembly (Opa) For Sustainable Resource Recovery To Enable Long-Duration, Deep-Space Human Exploration (Loddshe), Talon James Bullard Jun 2020

Development Of An Organic Processor Assembly (Opa) For Sustainable Resource Recovery To Enable Long-Duration, Deep-Space Human Exploration (Loddshe), Talon James Bullard

USF Tampa Graduate Theses and Dissertations

Long-Duration, Deep-Space Human Exploration (LoDDSHE) missions demand robust and reliable technologies to ensure crew health, safety, and mission success. In situ food production will become essential for these missions for crew nutrition, morale, and in the event of delays or failures. At a current estimated cost $10,000/lb, mass and volume limitations will restrict necessary resources. For an anticipated thirty-month mission to Mars, these costs will increase due to more frequent resupply shipments and lengthened transit times, creating additional financial and logistical challenges (Pickett et al., 2019). Increased resource and waste recovery to achieve nearly closed-loop systems will mitigate many of …


Influence Of Elements Of Irrigation Equipment On Irrigation Erosion, M.M. Sarimsakov, O.S. Abdisamatov, Z.T. Umarova Jun 2020

Influence Of Elements Of Irrigation Equipment On Irrigation Erosion, M.M. Sarimsakov, O.S. Abdisamatov, Z.T. Umarova

Irrigation and Melioration

Irrigation erosion is a process that has a significant negative impact on agricultural production, which leads to a sharp decrease in soil fertility and productivity. The costs associated with growing crops will increase. Today, more than 720,000 irrigated lands in the country suffer from irrigation erosion. Studies have shown that in typical gray soils with a slope of more than 0.30, intensive irrigation of apple orchards leaches 24.6 tons of soil particles per hectare per season. Improved irrigation, that is, a decrease in the leaching of soil particles during irrigation using transverse barriers, was achieved by 6–12%. Irrigation reduces the …


Research Of Water Flow Motion In The Channel Of Amu-Bukhara Machine Channel, D.R. Bazarov, F. Artikbekova, M.P. Tashkhanova, B.M. Norkulov Jun 2020

Research Of Water Flow Motion In The Channel Of Amu-Bukhara Machine Channel, D.R. Bazarov, F. Artikbekova, M.P. Tashkhanova, B.M. Norkulov

Irrigation and Melioration

The article considers a numerical study of the movement of a water stream in the channel of the Amu Bukhara Machine Channel (ABMK). Water intake to the inlet canal is carried out from the Amu Darya river in a damless manner, therefore, ensuring the flow of clarified water into the anterior chambers of pumping stations is an urgent task. According to the developed model, consisting of hydrodynamic equations based on the laws of conservation of momentum and mass, data on the dynamics of velocities in the channel of the supply channel ABMK are obtained and zones of uneven flow in …


Irrigation Value The Mechanical Composition River Springs, A.M. Arifjanov, L.N. Samiev, F.K. Babajanov Jun 2020

Irrigation Value The Mechanical Composition River Springs, A.M. Arifjanov, L.N. Samiev, F.K. Babajanov

Irrigation and Melioration

The article studies the influence of the fractional composition of river sediments on the soil structure of irrigated lands and on the process of soil formation. According to surveys in the Mirishkor canal, sediments formed in the river are distinguished by the distribution type in the main canal. The fractional composition of sediments mainly consists of particles of fine sand (0.1-0.05 mm) and coarse dust (0.05-0.001 mm).According to the results of surveys, by studying the mechanical composition of sediment in the channel, it will be possible to observe changes in the amount of composition, such as N-NH4, P2O5, K2O chemicals. …


Monitoring System For Electricity Consumption At Pumping Stations, N. Ikramov, T. Majidov, A. Mukhammadjonov Jun 2020

Monitoring System For Electricity Consumption At Pumping Stations, N. Ikramov, T. Majidov, A. Mukhammadjonov

Irrigation and Melioration

Currently, in Uzbekistan, of 4.3 million hectares of irrigated land, 2.3 million hectares are provided with water supplied by pumping stations that are on the balance of the Ministry of water management of the Republic of Uzbekistan. In total, 1693 pumping stations with 5301 pumping units are operated, and the number of pumping stations ' personnel is about 16,000 people. The total capacity of these pumping stations is about 7000 m3/s. the Total annual energy consumption of these pumping stations is about 8.0 billion kW·h or about 12.5% of the annual electricity generation of the entire energy sector of Uzbekistan. …


Irrigation Value The Mechanical Composition River Spring The Effect Of The Inhomogeneity Of Elastic Medium On The Initiation Of Resonant Waves Under Moving Load, S.A. Abdukadirov, Z.S. Shаdmаnova, B.Sh. Yuldoshev Jun 2020

Irrigation Value The Mechanical Composition River Spring The Effect Of The Inhomogeneity Of Elastic Medium On The Initiation Of Resonant Waves Under Moving Load, S.A. Abdukadirov, Z.S. Shаdmаnova, B.Sh. Yuldoshev

Irrigation and Melioration

investigated. The waveguide properties of the system are preliminarily studied. The multiple roots of the dispersion equations are revealed and the critical load velocities leading to the formation of resonance processes are determined. The solutions of the dispersion equations make it possible to determine the additional critical velocities in the mid-wave spectrum depending on the structure parameters. For simple models, analytical solutions of the development of resonance processes are obtained that are asymptotically correct for relatively large values of time. The computer simulations allow us to analyze the quantitative features of the process over the entire time period of the …


Substantiation Of Sprayers Installed To A Universal Mounted Sprayer, D. Dzhuraev, M.S. Halilov, S.M. Badalov, I.Zh. Toirov, A.E. Urishev Jun 2020

Substantiation Of Sprayers Installed To A Universal Mounted Sprayer, D. Dzhuraev, M.S. Halilov, S.M. Badalov, I.Zh. Toirov, A.E. Urishev

Irrigation and Melioration

The article presents the results of theoretical and experimental studies on the creation of primary sprayers for sprayers. The flow diagrams of the atomizers that were produced on the territory of the former Soviet Union are given. Currently, various types of spray guns are manufactured in America, Germany, France, Italy, Bulgaria and other countries. Based on the set requirements for sprayers, to ensure fluid flow and spraying when deployed 90-110 degrees on a plane, a slotted sprayer is selected - manufacturer Lechler of the brand ST-110-05 Germany, for installation on a universal mounted sprayer. The results of fluid flow by …


Technological Features Of Moistening Of Technical Seeds, O. Matchanov, B. Tuxtamishev Jun 2020

Technological Features Of Moistening Of Technical Seeds, O. Matchanov, B. Tuxtamishev

Irrigation and Melioration

This article describes the technological features of the reduction of technical varieties of cotton. Requirements for technical seeds in the processing of raw cotton are technical specifications and quality indicators. Seeds of technical cotton with quality indicators and adapted technical seeds must meet the requirements of technical conditions. The technical need for coated seeds should correspond to technical characteristics, such as reducing production costs, reducing moisture, long-term storage, improving quality, thermal conductivity, aerodynamic resistance, and heat resistance. From the point of view of heat treatment of seeds, parameters taking into account their thermophysical properties should be used to justify the …


Regulations Of Hydraulic Resistance Of Machine Channels Of Pumping Stations, D.R. Bazarov, B.R. Uralov, M.P. Tashkhanova Jun 2020

Regulations Of Hydraulic Resistance Of Machine Channels Of Pumping Stations, D.R. Bazarov, B.R. Uralov, M.P. Tashkhanova

Irrigation and Melioration

The paper considers the general equation of fluid motion in the channels and the functional dependences of the hydraulic friction coefficient on the Reynolds number, relative roughness, and on the shape of the live section of the channel. Resistance formulas are given for the simplest cross-sectional shapes of channels and for channels with a more complex cross-sectional shape. To take into account the effect (on the pressure loss) of the channel cross-sectional shape and the presence of a flow with a free surface in it, additional correction factors are introduced (using the hydraulic radius concept) and be clarified as a …


Studying The Movement Of Crop Drined Seeds Of Cottage On A Slope Tray In A Protective Machine, R.K. Djamolov, A.A. Akrаmov, K. Djamolov Jun 2020

Studying The Movement Of Crop Drined Seeds Of Cottage On A Slope Tray In A Protective Machine, R.K. Djamolov, A.A. Akrаmov, K. Djamolov

Irrigation and Melioration

The article presents the results of a theoretical study of the movement of pubescent cotton seeds along an inclined guide in a pickling machine. Equations are obtained that describe the movement of the seed along the inclined tray of the dresser. A formula is derived for determining the time of movement of the seed on an inclined one to the dressing agent. A plot of the change in the speed of the seed in the tray on the change in the angle of inclination and on the value of the movement of the seed. To increase the feed rate of …


Modernization Of Functions Of Management Of Land Use In The Conditions Of Innovative Economy, Sh.K. Narbaev Jun 2020

Modernization Of Functions Of Management Of Land Use In The Conditions Of Innovative Economy, Sh.K. Narbaev

Irrigation and Melioration

Land use management, as a complex material-abstract system, is carried out through a number of its functions. The article provides an analysis of the functions of land management, improved the content of some functions and introduced additional new functions in the context of the development of an innovative economy. It is noted that improving the management system will increase the efficiency of land use, improve their environmental status, preserve landscape ecosystems based on the accelerated development of innovative activities. New land management functions are recommended: innovative land use development, territory development, land use technical support, remote study of land properties …


Combined Installation Photo Thermal Battery - Electric Water Heater To Provide Electricity And Water To Rural Households, R.A. Muminov, M.N. Tursunov, Х. Sabirov, U.R. Kholov, Т.Z. Аkhtamov, М. Eshmuradova Jun 2020

Combined Installation Photo Thermal Battery - Electric Water Heater To Provide Electricity And Water To Rural Households, R.A. Muminov, M.N. Tursunov, Х. Sabirov, U.R. Kholov, Т.Z. Аkhtamov, М. Eshmuradova

Irrigation and Melioration

The article presents the experimental results of the study of the parameters of a combined installation photo thermal battery – electric heater, used to provide electric energy and water to rural households. Photo thermal battery is made on the basis of photovoltaic batteries of crystalline silicon with an efficiency of ~ 20 %. Cellular polycarbonate was used as a heat sink. When creating the KU based on photo thermal battery EVN, modern efficient batteries, controllers, inverters and consumers of electric energy were used, and Ariston was chosen as the EVN. KU is adapted to climatic conditions, effectively and reliably provides …


Modeling The Movement Of A Heap In A Dielectric Sorting Device For Alfalfa Seeds, A. Lee, Z. Sharipov, M.N. Sattarov Jun 2020

Modeling The Movement Of A Heap In A Dielectric Sorting Device For Alfalfa Seeds, A. Lee, Z. Sharipov, M.N. Sattarov

Irrigation and Melioration

This article presents a theoretical study of modeling the movement of a mixture in a dielectric sorting plant for alfalfa seeds. Theoretical studies were carried out using the general laws of mechanics and mathematical modeling of alfalfa seeds, taking into account their physical and mechanical properties. The results of a theoretical study on modeling the detachment conditions of alfalfa seed heap particles and particle dynamics along the casing and pitched boards of a dielectric sorting device are presented. The differential equation with the initial conditions was solved by numerical methods of "Runge-Kutta-Felberg" with automatic step selection. The components of a …


Conceptual Approaches To Improve Quality Of The Process Of Preparation Energy Personnel For Agricultural Sector Of Economy, A. Radjabov Jun 2020

Conceptual Approaches To Improve Quality Of The Process Of Preparation Energy Personnel For Agricultural Sector Of Economy, A. Radjabov

Irrigation and Melioration

The article highlights problems of training energy personnel for agricultural sector and conceptual, principle and practical approaches to their solution based on goals and objectives outlined in concept of development of higher education system in Uzbekistan until 2030 and Strategy for development of agriculture Republic of Uzbekistan for 2020 - 2030


About Improvement Of Support Of Innovative Activity Of Higher Education By The State, A.E. Norov Jun 2020

About Improvement Of Support Of Innovative Activity Of Higher Education By The State, A.E. Norov

Irrigation and Melioration

This article provides information on regulatory acts in support of innovative activities in the field of higher education. It is also indicated that the fact that the scientific activities of universities are not organized based on the prospects for socio-economic development of regions, forecasting innovative development based on analysis and effectiveness of innovations, research results, commercialization of scientific developments, and the involvement of talented youth in research, is the reason for the lack of reliable integration of education, science and production. It is necessary to improve the internal system of competitions, programs and projects aimed at supporting the commercialization of …


Work In Progress: Development Of A General Education First-Year Design Course, Courtney Hollar, Sondra M. Miller Jun 2020

Work In Progress: Development Of A General Education First-Year Design Course, Courtney Hollar, Sondra M. Miller

Civil Engineering Faculty Publications and Presentations

We discuss in this Work in Progress paper the development of a new first-year engineering course at Boise State University. ENGR 180 Communication in Design Thinking, was developed in order to emphasize the importance of communication throughout the design process. Communication with the client at the start of the design process occurs in order to understand the problem to be solved. The team and other stakeholders continuously communicate in order to work toward developing a prototype to solve the problem. The ability to effectively communicate is equally as important to the design of the final product. The development of ENGR …


Dynamic Response Of Highway Bridge Superstructures Subjected To Wave Action: Experimental Analysis And Numerical Modeling, Alaa Waleed Hameed Jun 2020

Dynamic Response Of Highway Bridge Superstructures Subjected To Wave Action: Experimental Analysis And Numerical Modeling, Alaa Waleed Hameed

Dissertations and Theses

Bridges are critical lifeline components of the infrastructure network, enabling economies to function under normal conditions and disaster response and recovery missions to take place after extreme events. Therefore, ensuring satisfactory performance increases community resilience and minimizes both human and economic losses. Coastal bridges, which are the focus of this PhD dissertation, are vulnerable to coastal storms. High failure rates of these bridges during two major hurricane events in the mid-2000s have spurred research activities to better understand the wave-induced forces of coastal bridges.

This PhD research represents a continuation effort to build, implement, and introduce new fundamental concepts and …


Design Aspects, Energy Consumption Evaluation, And Offset For Drinking Water Treatment Operation, Saria Bukhary, Jacimaria Batista, Sajjad Ahmad Jun 2020

Design Aspects, Energy Consumption Evaluation, And Offset For Drinking Water Treatment Operation, Saria Bukhary, Jacimaria Batista, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Drinking water treatment, wastewater treatment, and water distribution are energy-intensive processes. The goal of this study was to design the unit processes of an existing drinking water treatment plant (DWTP), evaluate the associated energy consumption, and then offset it using solar photovoltaics (PVs) to reduce carbon emissions. The selected DWTP, situated in the southwestern United States, utilizes coagulation, flocculation, sedimentation, filtration, and chlorination to treat 3.94 m3 of local river water per second. Based on the energy consumption determined for each unit process (validated using the plant’s data) and the plant’s available landholding, the DWTP was sized for solar PV …


Automatic Delamination Segmentation For Bridge Deck Based On Encoder-Decoder Deep Learning Through Uav-Based Thermography, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen Jun 2020

Automatic Delamination Segmentation For Bridge Deck Based On Encoder-Decoder Deep Learning Through Uav-Based Thermography, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

Concrete deck delamination often demonstrates strong variations in size, shape, and temperature distribution under the influences of outdoor weather conditions. The strong variations create challenges for pure analytical solutions in infrared image segmentation of delaminated areas. The recently developed supervised deep learning approach demonstrated the potentials in achieving automatic segmentation of RGB images. However, its effectiveness in segmenting thermal images remains under-explored. The main challenge lies in the development of specific models and the generation of a large range of labeled infrared images for training. To address this challenge, a customized deep learning model based on encoder-decoder architecture is proposed …


Evaluating Cracking Performance Of Polymer Enhanced And Fiber Reinforced Microsurface Mixtures Using Asphalt Laboratory Testing, George Joseph Shackil Jun 2020

Evaluating Cracking Performance Of Polymer Enhanced And Fiber Reinforced Microsurface Mixtures Using Asphalt Laboratory Testing, George Joseph Shackil

Theses and Dissertations

This study presents a method to improve and evaluate the cracking resistance of microsurfacing mixtures using common asphalt laboratory testing. A preliminary optimal timing study and a study to evaluate improvements to cracking performance were conducted. The control mixture was based on NJDOT standard mix design specifications. Three mixtures were tested in this study: a fiber reinforced mixture using one-quarter inch glass fibers, an emulsion with increased SBR (polymer) contents, and a mixture using the one-quarter inch glass fibers combined with the increased polymer contents. Three laboratory tests were used to evaluate three different cracking resistance parameters: crack initiation (Semi-Circular …


Climate Change Impacts The Subsurface Transport Of Atrazine And Estrone Originating From Agricultural Production Activities, Renys Enrique Barrios, Simin Akbariyeh, Chuyang Liu, Khalid Muzamil Gani, Margarita T. Kovalchuk, Xu Li, Yusong Li, Daniel D. Snow, Zhenghong Tang, John Gates, Shannon L. Bartelt-Hunt Jun 2020

Climate Change Impacts The Subsurface Transport Of Atrazine And Estrone Originating From Agricultural Production Activities, Renys Enrique Barrios, Simin Akbariyeh, Chuyang Liu, Khalid Muzamil Gani, Margarita T. Kovalchuk, Xu Li, Yusong Li, Daniel D. Snow, Zhenghong Tang, John Gates, Shannon L. Bartelt-Hunt

Nebraska Water Center: Faculty Publications

Climate change will impact soil properties such as soil moisture, organic carbon and temperature and changes in these properties will influence the sorption, biodegradation and leaching of trace organic contaminants to groundwater. In this study, we conducted a modeling case study to evaluate atrazine and estrone transport in the subsurface under current and future climate conditions at a field site in central Nebraska. According to the modeling results, in the future, enhanced evapotranspiration and increased average air temperature may cause drier soil conditions, which consequently reduces the biodegradation of atrazine and estrone in the water phase. On the other hand, …


Mobile Manipulating Drones, Paul Oh Jun 2020

Mobile Manipulating Drones, Paul Oh

INSPIRE Archived Webinars

In the past few years, robotic limbs have been attached to rotorcraft drones to perform aerial manipulation. Unlike simple object pick-and-place, such mobile-manipulating drones are dexterous to perform tasks like valve-turning, hatch-opening, and tool-handling. This is a paradigm shift where such drones actively interact with their environment rather than just passively surveil. Aerial manipulation is challenging because such interaction yields reaction forces and torques that destabilize the drone. This talk will provide an overview of aerial manipulation and showcase examples that could serve in infrastructure inspection, maintenance, and repair.


Constitutive Model Of Lateral Unloading Creep Of Soft Soil Under Excess Pore Water Pressure, Wei Huang, Kejun Wen, Xiaojia Deng, Junjie Li, Zhijian Jiang, Yang Li, Lin Li, Farshad Amini Jun 2020

Constitutive Model Of Lateral Unloading Creep Of Soft Soil Under Excess Pore Water Pressure, Wei Huang, Kejun Wen, Xiaojia Deng, Junjie Li, Zhijian Jiang, Yang Li, Lin Li, Farshad Amini

Civil and Architectural Engineering Faculty Research

Presented in this paper is a study on the lateral unloading creep tests under different excess pore water pressures. The marine sedimentary soft soil in Shenzhen, China, was selected in this study. The results show that the excess pore water pressure plays a significant role in enhancing the unloading creep of soft soil. Higher excess pore water pressure brings more obvious creep deformation of soft soil and lower ultimate failure load. Meanwhile, the viscoelastic and the viscoplastic modulus of soft soil were found to exponentially decline with creep time. A modified merchant model and a combined model of the modified …


Retention Of Swine Slurry Constituents In Soil And Crop Residue As Affected By Setback Distance, John E. Gilley, Shannon L. Bartelt-Hunt, Kent M. Eskridge, Xu Li, Amy M. Schmidt, Daniel D. Snow Jun 2020

Retention Of Swine Slurry Constituents In Soil And Crop Residue As Affected By Setback Distance, John E. Gilley, Shannon L. Bartelt-Hunt, Kent M. Eskridge, Xu Li, Amy M. Schmidt, Daniel D. Snow

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Setbacks are prescribed distances from surface waters within which manure application is not allowed. Little information is available concerning the retention of swine slurry constituents in soil and crop residue materials within setback areas. This study was conducted to measure the retention of selected constituents within a setback area following the upslope application of swine slurry and the introduction of simulated rainfall. The no-till cropland site had a slope gradient of 4.9% and a mean winter wheat residue cover of 7.73 Mg ha−1 . Soil and vegetative samples were collected on 3.7 m wide by 23.2 m long plots with …