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2020

Environmental Engineering

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Full-Text Articles in Engineering

Characterizing Reactive Iron Mineral Coatings And Their Roles In Natural Attenuation At A Site With Historical Contamination, Han Hua Dec 2020

Characterizing Reactive Iron Mineral Coatings And Their Roles In Natural Attenuation At A Site With Historical Contamination, Han Hua

Dissertations

Reactive iron mineral coatings in redox transition zones play an important role in contaminant attenuation. These mineral coatings include poorly crystalline to crystalline iron sulfides, carbonates, and oxyhydroxides, and are a signature of the biogeochemical processes occurring. To better understand these processes, reactive iron mineral coatings are characterized in an 18-m Anaerobic Core collected from a contaminated industrial site. This study targets redox transition zones uncovered in the core. A suite of complementary analyses is applied to distinguish the surface coating mineralogy using X-ray Diffraction, X-ray fluorescence, and field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray analyzer (EDX). In …


The Stability Of Nanobubbles And Its Application In Contaminated Sediment Treatment, Shaini Dilsha Aluthgun Hewage Dec 2020

The Stability Of Nanobubbles And Its Application In Contaminated Sediment Treatment, Shaini Dilsha Aluthgun Hewage

Dissertations

This dissertation consists of two sections. First, nanobubbles' stability and behavior are studied using experimental and theoretical approaches. Second, nanobubbles application combined with ultrasound to remediate contaminated sediments is discussed.

The stability study consists of four sections. (i). Laboratory investigation to determine bubble size distributions and zeta potentials for different gases, pH levels, temperatures, and salt conditions. (ii). A theoretical study based on the diffused double layer theory to explain nanobubbles' behavior in different NaCl concentrations. (iii). Nanobubbles' stability in electrolyte solutions under different ion valencies using deionized water, NaCl, Na2SO4, Na3PO4, …


Prospects For Solving The Problem Of Rational Use Of Water Resources Using The Tiiame-1 Sprinkling Machine, M.Kh. Khamidov, A.R. Muratov Dec 2020

Prospects For Solving The Problem Of Rational Use Of Water Resources Using The Tiiame-1 Sprinkling Machine, M.Kh. Khamidov, A.R. Muratov

Irrigation and Melioration

The information published by the International Commission on Irrigation and Drainage, and the intermediate results of many years of research carried out by scientists from TIIAME on the development, research and implementation of water-saving technologies in agriculture are presented. The acute shortage of water resources in Central Asia, the problems of increasing the efficiency of the use of water-saving technologies around the world have led to the careful use of available water resources in the region, including the prospects and advantages of using irrigation of crops by sprinkling, as well as the design and technical parameters of the sprinkler developed …


Inadequacy Of Current Water Use Planning At The Level Of Water Users And Wuas, A.A. Alimdjanov, A.Kh. Karimov, B.R. Nasibov Dec 2020

Inadequacy Of Current Water Use Planning At The Level Of Water Users And Wuas, A.A. Alimdjanov, A.Kh. Karimov, B.R. Nasibov

Irrigation and Melioration

This paper studies the main issues of water use planning at the level of water consumers and water user associations (WUA). The study carried out in Bulakbashi district of Andijan province of Uzbekistan, where the main source of irrigation water is the Southern Fergana Main Canal. The study followed two-stage procedure. During the first stage we compiled water use plans for the WUA and water consumers based on the applied methodology of water use planning. Then, at the second stage, we analyzed the results of the actual implementation of the farm water consumption plans and WUA water use plan, and …


Technology And Technical Device Used In The Efficient Use Of Water Resources In Irrigated Agriculture, А.U. Аtajanov Dec 2020

Technology And Technical Device Used In The Efficient Use Of Water Resources In Irrigated Agriculture, А.U. Аtajanov

Irrigation and Melioration

The economical use of water resources, the improvement and development of new technology and technical means for its implementation, ensuring the saving of irrigation water is one of the most important issues of today. This article is devoted to the issues of improving the technology of irrigation of furrows and the creation of technical means,also recommended technology and using from created technical device in selected per experiment fields and analyzing their results.


Empirical Assessment Of Climate Change Impacts On Agriculture In Samarkand Region, Sh.B. Babakholov Dec 2020

Empirical Assessment Of Climate Change Impacts On Agriculture In Samarkand Region, Sh.B. Babakholov

Irrigation and Melioration

Agricultural production is highly sensitive to climate factors like other endogenous factors, and the expected climate change projections may have a negative impact on the efficiency and income of agricultural producers. Therefore, this study aims to analyze the impact of changes in climatic factors (average air temperature and precipitation) on the technical efficiency of cotton growing farmers as its determinants in Samarkand region. Empirical analyzes were performed on the cases of 1141 cotton-growing farms using panel-based Time-Invariant Inefficiency model. According to the results of the analysis, cotton farms in the region have an average technical efficiency of 76%, which in …


Car Wash Complex – Object Of Harmful Impact On Water Resources, M. Radkevich, K. Shipilova, M. Abdukodirova, O. Pochugevski Dec 2020

Car Wash Complex – Object Of Harmful Impact On Water Resources, M. Radkevich, K. Shipilova, M. Abdukodirova, O. Pochugevski

Irrigation and Melioration

Deals with the problem of the impact of car wash complexes in the city of Tashkent on water resources. The analysis of the technological process of washing and a sociological survey of car owners and employees of car washes revealed the average amount of water used per car wash per year, as well as the amount of harmful substances entering the sewer network of the city of Tashkent. Calculations have shown that the annual water consumption only for passenger cars in Tashkent is about 4.34 million m3, and the wastewater is not properly treated. From one car wash …


Agrochemical Indicators Of New Irrigated Graph-Meadow Soils Formed On The Iii Underfladder Terrace Of Syrdarya, J.M. Kuziev Dec 2020

Agrochemical Indicators Of New Irrigated Graph-Meadow Soils Formed On The Iii Underfladder Terrace Of Syrdarya, J.M. Kuziev

Irrigation and Melioration

Presents material on the geographical location, geomorphological and geological structure, as well as the agrochemical state of irrigated serozem-meadow soils, common in the Mirzaabad district of the Syrdarya region. According to the data obtained on the chemical analysis of soils, the studied soils are medium- and heavily loamy in texture, where particles of coarse sand predominate (0.05-0.01%). In the arable horizon of these soils, the humus content is 1.088-1.214%, total nitrogen 0.079-0.089%, total phosphorus 0.109-0.124%, and total potassium within 1.15-1.24%, and on the basis of these data, a regularity of the underlying horizon of these soils. The degree of provision …


Water Efficient Technology Of Drip Irrigation In Intensive Gardens, F.U. Juraev, G.H. Karimov Dec 2020

Water Efficient Technology Of Drip Irrigation In Intensive Gardens, F.U. Juraev, G.H. Karimov

Irrigation and Melioration

The studies were carried out in 2017-2019 at the Zodabek farm on a 6 hectare garden plot with seedlings of half-tall apple trees “Golden Delicious”. Experimental research work was carried out at a groundwater level in the experimental area of 1.5-2.0 m, mineralization 1.0-1.2 g/l in alluvial, mechanical, medium sandy soils with the following irrigation options. The first option is irrigation, at the start of the second - drip irrigation; third, the use of specially designed soil pegs. The following results were obtained: in the control option, the average irrigation rate for three years was 1125.7 m3/ha, with drip irrigation …


Forecasting The Dynamics Of Cotton Yield In The Ferghana Region, V. Vakhobov, А.А. Faiziev Dec 2020

Forecasting The Dynamics Of Cotton Yield In The Ferghana Region, V. Vakhobov, А.А. Faiziev

Irrigation and Melioration

Observations of a certain phenomenon, the nature of which changes over time, give rise to an ordered sequence, which is called a time series. In the article, using the method of statistical time series analysis, statistical pattern of time series Y1 – average yield of cotton in Fergana region of the Republic of Uzbekistan(on materials of CSB of the Republic of Uzbekistan for 1991-2018 years). Point and interval estimates for the average cotton yield were constructed with a 95% guarantee, explicit types of trends were determined, and the yield in the region was predicted for subsequent years. Using statistical …


Hydraulic Elevator For Purification Of Water Supply Facilities Of The Reservoir, R.R. Ergashev, F. Atrikbekova, H. Khusanboeva, B.T. Kholbutaev, N.A. Babazhanov Dec 2020

Hydraulic Elevator For Purification Of Water Supply Facilities Of The Reservoir, R.R. Ergashev, F. Atrikbekova, H. Khusanboeva, B.T. Kholbutaev, N.A. Babazhanov

Irrigation and Melioration

The purpose of the research is to increase the efficiency of pumping stations operation by improving the methods of uniform flow spreading in the front chamber and inlet of the pumping station and developing constructive measures to improve the hydraulic conditions for supplying the flow to the pumps. The improvement of the method of hydraulic calculation of the flow in the front chamber and the water intake chamber is given on the example of the head pumping station of the Jizzakh cascade. In the process of research, standard methods of full-scale and bench tests of pumps, methods of mathematical and …


Energy-Saving Structure Justification Powerful Tractor And Modern Agricultural Machine, A.K. Igamberdiyev, N.A. Khalikova, N.B. Razikov, O.E. Usarov Dec 2020

Energy-Saving Structure Justification Powerful Tractor And Modern Agricultural Machine, A.K. Igamberdiyev, N.A. Khalikova, N.B. Razikov, O.E. Usarov

Irrigation and Melioration

Discusses the fact that machine-tractor units (MTA) from high-power tractors are often not fully used due to errors in the design and operation of units, their ability to work under certain operating conditions with maximum efficiency and minimum fuel consumption, a method of completing a machine-tractor unit from a high-power technical means is proposed, which ensures the required quality of the technological operation, maximum efficiency and minimum fuel consumption, which must be performed under certain operating conditions. To study the power balance of energy-saving units, consisting of powerful tractors and modern agricultural machinery, an analysis was carried out of a …


Traction Control Of The Friction Drive Of The Vertical Spindle, M. Shoumarova, T. Abdillaev, Sh.A. Yusupov, Ch.A. Shermatova Dec 2020

Traction Control Of The Friction Drive Of The Vertical Spindle, M. Shoumarova, T. Abdillaev, Sh.A. Yusupov, Ch.A. Shermatova

Irrigation and Melioration

The main indicator in assessing the quality of the work of cotton pickers is its completeness of picking cotton, among the factors that predetermine the completeness of picking a special place is occupied by the direction and magnitude of the absolute speed of the spindle tooth. Among the factors affecting the absolute speed of the tooth, the main place is occupied by the angular speed of rotation of the spindle around its own axis, which depends on the quality of functioning of the friction drive of the spindle. This drive does not always provide its required traction capacity, since due …


Research The Chopper Apparatus Of Equipment For Chopping Pressed Rough Fodders, Sh.H. Gapparov, N.A. Ashurov Dec 2020

Research The Chopper Apparatus Of Equipment For Chopping Pressed Rough Fodders, Sh.H. Gapparov, N.A. Ashurov

Irrigation and Melioration

Livestock is one of the most important agricultural sectors in Uzbekistan and it is based on family livestock farms. On family farms, livestock animals are fed with pressed roughage, including corn stalks, alfalfa hay, barbed straw and wheat straw, mixed with concentrated feed. However, due to the lack of small choppers suitable for small farms, the compressed feed is fed to animals without chopping, as a result of which about 25-30 percent of them go to waste and there are large losses. Taking this into account, a small device was developed for chopping pressed roughage and mixing it with concentrated …


Theoretical Research On Determining The Length Of The Shovels Of A Wheel Of Centrifugal Fans, V.A. Arkhipov, D. Dzhuraev, I.Zh. Toirov, A.E. Urishev Dec 2020

Theoretical Research On Determining The Length Of The Shovels Of A Wheel Of Centrifugal Fans, V.A. Arkhipov, D. Dzhuraev, I.Zh. Toirov, A.E. Urishev

Irrigation and Melioration

Presents the results of theoretical research by scientists, carried out scientific work to determine the length of the shovel of a centrifugal fan wheel. A technological scheme for installing a shovel on a fan wheel disk has been developed Analyzes of these works are carried out, which show that the length of the wheel shovel has a significant dependence on the parameters of the wheel (R, R1), the angle of installation α and the radius of the arc R3 of the shovel. An analytical dependence is derived for determining the length of the shovel of a …


An Experimental Investigation Of Alternative Wave Attenuation Mechanisms For A Modular Breakwater, Richard Perry Dec 2020

An Experimental Investigation Of Alternative Wave Attenuation Mechanisms For A Modular Breakwater, Richard Perry

Electronic Theses and Dissertations

Global warming and sea level rise threaten to render traditional coastal protection structures as less effective. Floating breakwaters offer the advantages of adapting to rising sea level, allowing important material transport to occur, and being able to deploy and adapt to varying environmental conditions (seabed, depth, etc.). Traditional floating breakwaters typically consist of reflective concrete structures that are limited semi-sheltered locations. This research aimed to construct floating breakwaters out of lightweight materials with a smaller footprint while utilizing alternative attenuation mechanisms. Three breakwaters consisting of a box, beach, and pipe designs were constructed at 1:40 scale and tested in a …


Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari Dec 2020

Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari

Doctoral Dissertations

Oxygenic photogranules (OPGs) are dense spherical microbial aggregates that are used for self-aerating wastewater treatment. Filamentous cyanobacteria are key granulating species, providing structural backbone and integrity in OPGs. Currently, the mechanisms for selecting filamentous cyanobacteria and their ability to form spherical OPGs are not well understood. Literature shows that iron (Fe) availability plays a significant role in the cyanobacterial growth and colony formation. Moreover, Fe availability is known to be dependent upon light, which is an essential growth substrate for the phototrophs. This research has investigated the role of Fe in the photogranulation phenomenon and the impact of light intensity …


Biodegradability Of Cellulose And Its Impact On Oxygen Transfer Efficiency And Biological Nutrients Removal, Ahmed Shawki Ahmed Dec 2020

Biodegradability Of Cellulose And Its Impact On Oxygen Transfer Efficiency And Biological Nutrients Removal, Ahmed Shawki Ahmed

Electronic Thesis and Dissertation Repository

Cellulose from toilet paper is a significant fraction of particulate organics, which is recoverable. For the first time, comprehensive mapping and tracking the fate of cellulose across various unit processes at full-scale in two water resource recovery facilities located in North America and Europe was undertaken. The influent cellulose content accounted for approximately one-third of the total suspended solids (TSS). More than 80% of the raw wastewater cellulose was captured in primary treatment. The high cellulose content of the primary sludge accounting for 17%-35% of the TSS facilitates cellulose recovery. Cellulose biodegradation efficiency varied between 70%-90% of the primary effluent, …


Bibliometric Survey On Effect Of Climate Factors On Spread Of Coronavirus (Covid-19), Seema Patil, Jay Makwana, Manish Attri Dec 2020

Bibliometric Survey On Effect Of Climate Factors On Spread Of Coronavirus (Covid-19), Seema Patil, Jay Makwana, Manish Attri

Library Philosophy and Practice (e-journal)

The new SARS-CoV-2 COVID-19 has spread quickly around the globe since it was first reported in Wuhan city of China, in December 2019 subsequent to being contracted from a zoonotic source. The main focus of this bibliometric survey is to recognize the few studies which have upheld the epidemiological hypothesis that the effect of climatic factors is playing a crucial role in the spreading of COVID-19. The analysis is done on the basis of 412 documents such as journals, articles, editorials, short surveys and some review papers. The United States contributes to the maximum number of publications followed by the …


Bibliometric Survey On Effects Of Climate Change On Incidences Of Infectious Diseases, Seema Harshad Patil, Yatharth Jain, Vedant Marathe Dec 2020

Bibliometric Survey On Effects Of Climate Change On Incidences Of Infectious Diseases, Seema Harshad Patil, Yatharth Jain, Vedant Marathe

Library Philosophy and Practice (e-journal)

For understanding the influx of Infectious Diseases, research of climate change and its effects pertaining to the diseases is important. The motive of this bibliometric survey is to understand the research which has been carried out regarding the aforementioned topics. This paper summarizes the research in the 21st Century from 2001 to present. We conducted this analysis using tools such as Gephi, Researchgate, Scopus, ScienceScape, Google Scholar and Mapchart. This Bibliometric Survey on “Effects of Climate Change on Infectious Diseases” showed that maximum publications are articles. These publications are from conferences and journals related to Environmental Science. The United States …


Laboratory Testing And Mechanistic Analysis Of Treated Subgrade Soils, Hari Kumar Reddy Yarrapureddi Dec 2020

Laboratory Testing And Mechanistic Analysis Of Treated Subgrade Soils, Hari Kumar Reddy Yarrapureddi

Civil Engineering Theses

Calcium-based stabilizing agents such as cement and lime have been extensively used to improve the engineering properties of base and subgrade layers of pavement systems. Recently, polymers and chemical stabilizers have become popular due to cost efficiency, ease of application, and fast curing times. In this study, California Bearing Ratio (CBR) values of polymer and chemical treated soils were compared with the CBR values of soils treated with conventional stabilizers. Parametric sensitivity analyses was carried out on key parameters including the type of subgrade soil, stabilizing agent, stabilizing agent treatment levels, and moisture conditioning. Additionally, numerical analyses was performed to …


Expanding The Concept Of Comprehensive Area Ratio Parameter To The South-Central States Towards Simplifying The Structural Evaluation Of Flexible Pavements At The Network Level, Nitish R. Bastola Dec 2020

Expanding The Concept Of Comprehensive Area Ratio Parameter To The South-Central States Towards Simplifying The Structural Evaluation Of Flexible Pavements At The Network Level, Nitish R. Bastola

Civil Engineering Theses

The surface deflection bowl data collected through Non-Destructive Testing (NDT) has been widely utilized by various Department of Transportation (DOTs) in the South-Central States and other places. The primary purpose of using deflection-based NDTs in network-level assessment is to identify a weak pavement section that requires further analysis at the project level. The falling weight deflectometer (FWD) test is one of the common NDT based tests utilized by highway agencies in assessing the performance of the flexible pavement. However, a robust method to evaluate pavement sections utilizing FWD data from all the sensors are seldom developed. There is always a …


Policy Changes Impact In Deforestation Of The Brazilian Amazon, Iara Silva Jaques Dec 2020

Policy Changes Impact In Deforestation Of The Brazilian Amazon, Iara Silva Jaques

Master's Projects and Capstones

Since discovered and inhabited, the Brazilian Amazon has been explored and impacted negatively by human activities. The conversion of forest to pastureland and farmland, as well as mining activities, road opening, wood and ore extraction and fire are historically the main causes of environmental damages and forest loss in the region. This project overviewed the latest changes in environmental policy and practices towards environmental protection conducted by the Brazilian president Jair Bolsonaro, since he took office in 2019, and analyzed the progress of deforestation in the recent years under the new federal administration. Geographic Information System analysis were used to …


Uncertainties In The Assessment Of Individual And Compound Flooding From River Discharge And Coastal Water Levels Under Climate Change, Shuyi Wang Dec 2020

Uncertainties In The Assessment Of Individual And Compound Flooding From River Discharge And Coastal Water Levels Under Climate Change, Shuyi Wang

Electronic Thesis and Dissertation Repository

It is widely recognized that climate change can impact the risks of flooding in many regions around the world especially the low-lying coastal areas. The concurrent occurrence of multiple flood drivers such as high river flows and coastal water levels can aggravate such impacts causing catastrophic damages. In this study, the individual and compounding effects of riverine and coastal flooding are investigated over Stephenville Crossing, a town located in the coastal-estuarine region of Newfoundland and Labrador (NL), Canada. The impacts of climate change on flood characteristics and the corresponding uncertainties associated with model inputs and structure, and emission scenarios are …


Numerical And Experimental Investigation Of Aeration Self Mixing By Using Pulsating And Continuous Air Flow, Ahmed Ali Alkhafaji Dec 2020

Numerical And Experimental Investigation Of Aeration Self Mixing By Using Pulsating And Continuous Air Flow, Ahmed Ali Alkhafaji

Theses and Dissertations

Wastewater treatment is considered one of the most common forms of pollution control in the united states. Considered as an integral part of the wastewater treatment, the aeration process is the most energy-consuming process among all the processes that take place in any wastewater treatment plant. According to the United States Environmental Protection Agency (EPA), a wastewater treatment plant is expected to remove at least 85% of the suspended solids and dissolved organic compounds from the wastewater before discharging it to a river or a lake. The normal operation of the aeration process is by compressing air continuously to basin …


Moisture Monitoring Of A Clt Structure In A Southern Climate, Elizabeth Poblete Dec 2020

Moisture Monitoring Of A Clt Structure In A Southern Climate, Elizabeth Poblete

Graduate Theses and Dissertations

Understanding of moisture behavior in cross laminated timber (CLT) is critical to the widespread use of CLT in construction in the United States. Currently, very little data exists on the long-term impact of moisture on CLT. The objective of this research is to collect data regarding the long-term moisture variation in the CLT panel at the University of Arkansas Adohi Hall residence hall. The climate of Northwest Arkansas is different from previously monitored buildings, as they were in the Pacific Northwest. Comparatively, Northwest Arkansas has a warmer climate with higher average annual precipitation. Waterproofing efforts are usually employed to prevent …


Sustainability In Construction: Using Lean Management Principles To Reduce Waste, Matthew Waite Dec 2020

Sustainability In Construction: Using Lean Management Principles To Reduce Waste, Matthew Waite

Theses and Dissertations

The construction industry is facing many challenges. There are growing consumer demands for sustainable building. The construction industry generates a significant portion of the waste going into landfills. The construction industry has failed to keep pace with productivity in the manufacturing industry. Through adoption of Lean management principles, the construction industry can become more sustainable while increasing productivity. The literature was evaluated for three concepts: Lean management principles interaction with sustainability, the current state of sustainability in the construction industry, and the current state of Lean management principles in the construction industry. Lean management philosophies interactions with sustainability has been …


Leading Change During The Convergence Of An Epidemic And A Pandemic, Sarah Oerther, Daniel B. Oerther Dec 2020

Leading Change During The Convergence Of An Epidemic And A Pandemic, Sarah Oerther, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As the first wave of COVID-19 cases spread around the globe in early 2020, the healthcare community adopted a medical model that emphasized the use of resources to mitigate viral spread (Oerther & Watson, 2020). Schools, churches, and businesses shutdown, and healthcare facilities – from outpatient clinics to inpatient elective surgeries – were closed or cancelled. Even long-term care facilities, such as nursing homes, limited access of visitors to patients in an attempt at mitigation. And for six months, the healthcare community focused almost exclusively on a medical response to COVID-19, securing stockpiles of ventilators and fast-tracking vaccine development.


Detailed Modeling Of The Flash Hydrolysis Of Algae For Biofuel-Production In Comsol Multiphysics, Noah Joseph Legrand Dec 2020

Detailed Modeling Of The Flash Hydrolysis Of Algae For Biofuel-Production In Comsol Multiphysics, Noah Joseph Legrand

Mechanical & Aerospace Engineering Theses & Dissertations

Algae-derived biofuels are being commercialized as an important renewable energy source. Like any new technology, conversion improvements are desired, including reductions in process complexity and better utilization of the entire microalgae feedstock. The Old Dominion Biomass Laboratory has focused on flash hydrolysis for algae biofuel production. That process involves rapidly heating algae and water mixed as a slurry to a subcritical state. Results from small-scale bench tests are promising, but process scale up is a challenge. Currently there exists a pilot laboratory scale system utilizing induction heating in order to reach controlled reaction temperatures with a reaction duration of 10 …


Assessing Grassed Waterway Implementation Using Acpf And Swat Models, Kirsten Schaefer Dec 2020

Assessing Grassed Waterway Implementation Using Acpf And Swat Models, Kirsten Schaefer

MSU Graduate Theses

Agriculture is the most significant contributor of nonpoint source pollutants in US waterways, with sediment being the most prevalent cause of impairments. Sediment loss mitigation occurs through Best Management Practices (BMPs), such as grassed waterways. Federal and state agencies incentivize the implementation of BMPs through cost-share programs for farmers. The investment of public funds has increased pressure to demonstrate the effectiveness and value of individual projects, necessitating the development of strategies for prioritizing projects based on the sensitivity of sites to sediment erosion and optimal locations for implementation. This study has three primary objectives: (i) document existing locations of grassed …