Master of Science, The Ohio State University, 2024, Dentistry

Introduction: The purpose of this study was to evaluate the efficacy of three irrigation techniques: standard syringe irrigation (SI), ProUltra PiezoFlow (CUI) and EdgeEndo Er,Cr:YSGG (LAI) laser in removing calcium hydroxide from the mesial canals of moderately to severely curved mandibular molars using micro-CT analysis. Methodology: Mesial canals of 30 extracted human mandibular molar teeth were prepared with to size 30/.04 taper or 35/.04 taper rotary instruments. Teeth were randomly assigned to the three experimental groups (n = 10) with evenly distributed degrees of curvature. All teeth were scanned with micro-CT following rotary instrumentation. Calcium hydroxide was placed into prepared canals and sealed for 14 days. A micro-CT scan was taken to determine calcium hydroxide paste volume in each tooth. Canals were irrigated utilizing 3 techniques and re-scanned. Volume and percent change of calcium hydroxide before and after irrigation calculated and analyzed. Results: Calcium hydroxide paste remained in all groups after irrigation. The SI group removed -0.09% in the apical segment (0-3 mm) and 14.1% in the middle segment (3-6 mm). LAI removed 48.8% in the apical segment and 72.1% in the middle segment. CUI removed 14.9% in the apical segment and 50.1% in the middle segment. Conclusion: Irrigation with LAI removed significantly more calcium hydroxide in the middle and apical segments when compared to CUI and SI (p < 0.05). CUI removed significantly more calcium hydroxide in the middle and apical segments compared to SI (p < 0.05).

Committee: John Nusstein (Advisor); Melissa Drum (Committee Member); Sara Fowler (Committee Member) Subjects: Dentistry

Master of Science in Engineering (MSEgr), Wright State University, 2014, Mechanical Engineering

Agriculture is a significant measure of an economy for a number of countries in the world. Currently, the agriculture sector relies heavily on conventional sources of energy for irrigation and other purposes. When, considering factors such as increasing costs of fossil fuels and extending new power lines, especially to remote locations where grid electricity is either inaccessible or expensive, a solar PV (photovoltaic) irrigation system can be an effective choice for irrigating farmland. Solar power eliminates the need to run electrical power lines to remote agriculture locations, which quickly turns the monetary equation in favor of solar irrigation over grid-powered irrigation. In addition, the cost of delivering fossil fuels to remote locations can be expensive. Solar power is ideal for agricultural irrigation, as most irrigation is required when the sun is shining brightly. Consequently, a PV powered irrigation system is a promising technology that could help meet the irrigation needs of remote agricultural. The two major goals of this research are to get an existing solar PV irrigation system working and to acquire experimental data using this system under various operating conditions. This research work is built upon a series of three senior design projects. These three senior design projects were to design and construct a solar irrigation system, an instrumentation system for this solar irrigation system, and a single axis solar translator. Specifically this thesis work entailed getting the instrumentation system to work properly, writing a LabVIEW program to automatically acquire data from installed sensors, integrating all three of these senior design projects into one PV irrigation system, getting the PV irrigation system installed on the roof of the Russ Engineering Building, and collecting a large amount of data on the system. All have been accomplished successfully. The PV irrigation system work presented in this thesis use two 224 watt PV modu (open full item for complete abstract)

Committee: James Menart Ph.D. (Advisor); Rory Roberts Ph.D. (Committee Member); Zifeng Yang Ph.D. (Committee Member) Subjects: Alternative Energy; Energy; Engineering; Mechanical Engineering

Master of Science, The Ohio State University, 2016, Agricultural, Environmental and Developmental Economics

Tanzania's economy has long relied on traditional crop exports. In recent years, horticultural crops have offered a new niche for improving the country's export earnings, and smallholder farmer participation in the sector can provide an important impetus for this trend. Although much recent research has noted the potential of mechanization and agrochemical use in production, few studies have focused on yield and water use technology efficiency among smallholder farmers. The present study seeks to determine the extent of technology use by smallholder horticultural farmers; to assess their willingness to pay for better irrigation techniques; to identify any difference in yields between modern and traditional irrigation techniques; and to quantify the farm enterprise budget for select horticultural crops. The study was conducted in the northern part of Tanzania, targeting a total of 305 farmers. A questionnaire was used to collect primary data. MS Excel was used for data coding and cleaning, and the data were then analyzed using SPSS and GENstat. Key variables included yield, income, farm size, price, and a number of demographic characteristics. The results indicate a significant difference in yields for farmers using modern irrigation techniques as compared to traditional methods, and show that technology adoption is influenced by a farmer's age, education, and other socio-economic factors. While farmers are apparently making some profit on horticultural crops, this is insufficient to finance the very high initial investment cost of modern irrigation infrastructure. It is recommended that policy makers and private sector should consider socio-economic factors when mainstreaming smallholder farmers into horticultural industry production and productivity.

Committee: Abdoul Sam (Advisor) Subjects: Agricultural Economics; Agriculture; Technology

Master of Science, The Ohio State University, 2010, Agricultural, Environmental and Developmental Economics

This thesis is an economic impact evaluation of the Prosperity Through Innovation (PTI) project in Zambia. The PTI program provides discount equipment vouchers for the purchase of micro-irrigation equipment. The project aims to develop supply chains of micro-irrigation equipment and increase household livelihoods through its use. The PTI project is a collaboration of two international development organizations, Mennonite Economic Development Associates, (MEDA) and International Development Enterprises (IDE). The two organizations collaborate in order to promote the expansion of irrigation technology supply chains and provide information and training for its use as well. The objectives of this study were to evaluate the factors affecting voucher redemption and effects of the project on livelihoods. The data for this study were collected in August 2009 in two of the project sites, Kabwe and Kafue. Both in the design of the study and the statistical methods used to evaluate the data, tests for self-selection bias were used. The Heckman two-stage procedure was used to account for the non-random assignment of program participants. The results of the analysis showed that age of the household head, agricultural knowledge, and the presence of friends or neighbors who already used micro-irrigation equipment were significant factors affecting voucher redemption. All three factors exhibited a positive influence on voucher redemption. Results from the Heckman two-stage estimation indicated no evidence of self-selection bias. For the purpose of this thesis, livelihood impacts were measured by the change in household assets between the beginning of the project and the time of the survey. Analysis showed the adoption of a treadle pump had a positive impact on household assets. The change in household assets over the study time period was on average 61,028 kwacha greater in households that adopted the pump compared to those that did not. Results for the impact of adoption of a drip (open full item for complete abstract)

Committee: David Kraybill (Advisor); Brent Sohngen (Committee Member) Subjects: Agricultural Economics; Economics

Master of Science, The Ohio State University, 1975, Graduate School

Committee: Not Provided (Other) Subjects:

Doctor of Philosophy, The Ohio State University, 2021, History

This dissertation explores the economic and political history of the Khivan Khanate during the period of the Qungrat Dynasty (1770-1920) and the impact of global capitalism on the economy of the Khanate. The early Qungrat rulers established a highly centralized state, rapidly expanded its irrigated agriculture, and strengthened the Khanate's military power. The formation of a strong military expanded the political influence of the Khanate over the regional trade routes that connected Central Asia to Astrakhan and Orenburg starting from the early 1810s. Mastering the trade opportunities offered by the expansion of Khivan authority and global industrial capitalism, Khivans benefited from a growing demand for cash crops. By the 1850s, Khivan merchants became the largest exporters of the highly coveted madder root (rubia tinctorum) to Russia, which drove a high volume of monetary transactions in the Khivan economy. At the turn of the 20th century, Khiva had one of the most diversified and monetized economies in Central Asia. However, the mainstream literature on Central Asian history often portrays the Khivan Khanate as the most isolated and least civilized state in the Central Asian region. Refuting the notion of ‘isolation', my dissertation explains how global commodity exchanges and capitalism shaped statecraft and military strategies of the early Qungrats by encouraging the expansion of irrigation and monetary transformation during the 19th-century. Drawing on an analysis of a wide array of archival documents including judicial records, financial deeds, slave reports, and diplomatic correspondence, I argue that environmental factors and the irrigation potential of the Khanate were crucial in the state building process of the early Qungrat rulers. The geographical location of the Khanate bestowed the Qungrat rulers with a comparative advantage in producing and controlling strategic cash crops including wheat. Drawing on this potential, the Qungrats were able to (open full item for complete abstract)

Committee: Scott Levi (Advisor); Thomas McDow (Committee Member); Jane Hathaway (Committee Member) Subjects: Economic History; History; Islamic Studies; World History

Master of Science, The Ohio State University, 2018, Food, Agricultural and Biological Engineering

Agricultural discharges are considered Non-Point Source (NPS) discharges. A controlled drainage/sub irrigation (CD/SI) water table management scheme was applied during the growing and non-growing seasons to determine the potential to reduce nitrate contamination of surface waters. During the non-growing season, controlled drainage was employed on the CD/SI plots, creating a seasonal wetland condition. The water table management study was conducted in Piketon, OH, at the OSU Piketon Research and Extension Center. The study evaluated the hydrology and the associated nitrogen losses from controlled drainage/sub irrigation (CD/SI) systems compared to those with subsurface drainage only (SSD) systems. The DRAINMOD water management computer model was used to predict the water table elevations, subsurface drainage and runoff flows, and nitrogen loads of these two drainage scenarios. The results of the study indicated a 48 to 62 % reduction in annual subsurface drainage flows and 55 to 56 % reduction in annual discharge from the CD/SI system in comparison to the SSD system. The annual nitrate-loads exported from the plots for the CD/SI system were 68 to 77 % lower than those from the SSD system. The study results suggest a substantial reduction in nitrate contamination of surface waters using the CD/SI water table management system. The predictions from the DRAINMOD computer model were compared with two years (1996-1997) of data recorded at the study site. The water table elevations predicted by the model were considered satisfactory for most periods of the year for the SSD and CD/SI systems. DRAINMOD did a good job of predicting subsurface drainage flow from the SSD system. The model over predicted drainage flow from the CD/SI treatment. Runoff from the SSD system was accurately predicted for one year and over predicted for the other year. Since DRAINMOD cannot account for changes in surface storage values within a simulation period the runoff from the CD/S (open full item for complete abstract)

Committee: Larry Brown Dr. (Advisor); Norman Fausey Dr. (Committee Member) Subjects: Agricultural Education; Agricultural Engineering; Civil Engineering; Engineering; Environmental Engineering; Hydrology; Natural Resource Management

Master of Science (MS), Ohio University, 2017, Mechanical Engineering (Engineering and Technology)

Moving water quickly and efficiently has always been crucial to human development, especially in agriculture. However, this challenge still often goes unmet, especially in the developing world where access to infrastructure and mechanized pumping equipment is limited. In such locations human power is the most readily available source of power. The Beale Continuously Variable Transmission (CVT), modeled and experimentally examined by Cyders (2012), has potential to address this challenge. This thesis will adapt the work done by Cyders to a slider-crank simulation paired with a positive displacement pump. Predictions of system flowrate response at varying combinations of pressure and input shaft speed will be made using this model, and will then be compared against experimental results taken from a physical prototype of the system. Comparisons between these data sets will form the final result of this project, and will inform recommendations for any future work.

Committee: Timothy Cyders Dr. (Advisor); Robert WIlliams Dr. (Committee Member); David Bayless Dr. (Committee Member); Ryan Fogt Dr. (Committee Member) Subjects: Engineering; Mechanical Engineering

Doctor of Philosophy, The Ohio State University, 1983, Graduate School

Committee: Not Provided (Other) Subjects: Economics

Doctor of Philosophy, The Ohio State University, 1970, Graduate School

Committee: Not Provided (Other) Subjects: Economics

Doctor of Philosophy, The Ohio State University, 1968, Graduate School

Committee: Not Provided (Other) Subjects: Economics

Doctor of Philosophy, The Ohio State University, 1957, Graduate School

Committee: Not Provided (Other) Subjects: Agriculture

Doctor of Philosophy, The Ohio State University, 1963, Graduate School

Committee: Not Provided (Other) Subjects: Geography

Doctor of Philosophy, The Ohio State University, 1953, Graduate School

Committee: Not Provided (Other) Subjects: Geography

Doctor of Philosophy, The Ohio State University, 1956, Graduate School

Committee: Not Provided (Other) Subjects: Agriculture

Doctor of Philosophy, The Ohio State University, 2015, Food, Agricultural and Biological Engineering

The Lower Scioto Cataloguing Unit (LSCU) (OH) is experiencing an increase in irrigated land area. Information on potential impacts of irrigation groundwater withdrawals expansion is needed to assist in the management of a sustainable irrigated land area expansion. It is essential that the evaluation accounts for potential changes in crop irrigation water requirements due to anticipated climate change to insure that the results of the study reflect the aspects of crop irrigation in the short and long term. The study used the Scippo Creek-Scioto River Watershed (SCSRW) (OH) as a case study, and focused on the two most important crops grown in the area of study, which were corn and soybeans. In a preliminary study, a hybrid model that coupled the multimodel ensemble method (Kharin and Zwiers, 2002, Christensen and Lettenmaier, 2007) to a Monte-Carlo simulation was developed to predict future seasonal gross irrigation water requirements. The hybrid model was tested for the years 1969 to 1999 and used to predict seasonal irrigation water requirements for corn for the year 2015 to 2099. A groundwater flow model was developed for the study area using MODFLOW and used to investigate the potential groundwater level decline and streamflow depletion. Mean drawdowns in the order of 0.05 m to 6.26 m occurred between 2015 and 2099 in response to the simulation of various withdrawal scenarios. A depletion model developed using the simulation results indicated that mean drawdowns in the aquifer system could reach 6 m within 73 years in the worst case scenario.

Committee: larry brown (Advisor); alfred soboyejo (Committee Member); franklin schwartz (Committee Member); norman fausey (Committee Member); andrew ward (Committee Member) Subjects: Agricultural Engineering; Agriculture; Agronomy; Engineering; Environmental Engineering; Environmental Science; Geology; Hydrologic Sciences; Hydrology; Natural Resource Management; Statistics

Master of Science, The Ohio State University, 2015, Food, Agricultural and Biological Engineering

Soils are the optimal means of wastewater treatment and dispersal for onsite wastewater treatment systems. However in Ohio many soils are not deep enough for traditional wastewater treatment systems that utilize soil. Surface irrigation is an alternative means for the dispersal of wastewater on shallower soils. For surface irrigation to be feasible for onsite applications it is necessary to irrigate year-round so storage is not necessary. Wastewater irrigation in cold weather raises questions about how the wastewater will interact with frozen soils and if pollutant runoff will occur. The impact of wastewater irrigation on runoff was evaluated on a field scale. The potential impacts of irrigation on soil freezing through multiple freeze-thaw cycles, common to Ohio, are evaluated in the controlled setting of the laboratory. Soil freezing was monitored in both settings using soil moisture and temperature sensors. The effectiveness of the sensors to monitor soil freezing in soils was evaluated.

Committee: Karen Mancl (Advisor); Peter Ling (Committee Member); Norman Fausey (Committee Member) Subjects: Agricultural Engineering

Master of Science, The Ohio State University, 2015, Horticulture and Crop Science

Sphagnum peat moss (SPM) has been the dominant substrate component in container plant production since the 1970's for both horticulturists and home gardeners due to its relative abundance and beneficial properties. However, environmental concerns linked to peat harvesting and availability issues have led to increasing trends to utilize less SPM and to adopt improved processing operations for peat extraction. One possible substitution for SPM is coconut coir dust (coir pith), but there is limited information on how a substrate's physical, chemical and biological properties will change with the substitution. This study evaluates the physical and chemical properties of coir pith from Sri Lanka and its effect on irrigation application efficiency and growth of container grown zinnia, when coir pith was substituted for SPM in a control substrate composed of 65% SPM while holding composted bark fines (CBF) and perlite volumes constant. This study includes four objectives: characterize each substrate components' (SPM, coir pith, and CBF) chemical, physical and hydraulic properties; characterize the chemical, physical and hydraulic properties of selected substrates when coir pith replaced SPM in a substitution series; determine the rate effect of SPM and coir pith on Zinnia hybrida (Profusion Knee High Red Zinnia) growth and performance in a greenhouse trial using a modified gravimetric on-demand irrigation system, that maintained substrate matric potential between -10 kPa and -1 kPa, to determine the growth and water use efficiency of the zinnias grown in the different substrates. Coir pith had lower pH, nitrogen content and organic matter and a higher electrical conductivity, phosphorus, potassium, sulfate, sodium, and chloride when compared to SPM. Coir pith has a similar bulk density, holds more water, has less air space, and has a higher total pore space than SPM. The chemical properties of the substrates plus a constant rate of fertilizer, varied significantly, an (open full item for complete abstract)

Committee: Daniel Struve (Advisor); Claudio Pasian (Advisor); Edward McCoy (Committee Member) Subjects: Horticulture

Doctor of Philosophy, The Ohio State University, 2014, Geography

Climate change will impact hydrological systems worldwide, and human societies will face increasing water resource vulnerabilities as a result. One key concern is the potential downstream impact of glacier recession in the world's tropical and temperate mountains. For communities at the foot of Ecuador's ice-capped volcanoes, glacial meltwater is a potentially important component of irrigation supply, and residents observe the region's rapidly retreating glaciers with mounting concern. In this dissertation, I present results from a uniquely integrative study examining the relationships among glacier retreat, hydrological change and water resource insecurity at Volcan Chimborazo. Combining remote sensing analyses, direct hydrological measurements, climate data analyses, and detailed household surveys, I report on the recent rate of glacier shrinkage, the role of glacial meltwater in the local hydrological system, the increasing insufficiency of water entering local irrigation systems, and the livelihood adaptations made necessary by increasing water stress. Results show that while Chimborazo lost 21% ± 9% of its glacier area between 1986 and 2013, each of Chimborazo's glacierized watersheds is a groundwater-dominated system. Even in the upper Rio Mocha, the only catchment where glacier meltwater is a regular component of surface runoff, glaciers generally directly contribute only ~5% of total discharge. There are indications of strong linkages between glacier meltwater and groundwater discharge, however, and this merits further investigation. Still, water stress is a prominent factor driving widespread local perceptions of reduced socio-economic well-being in recent decades. While instrumental records document a local warming trend of 0.11°C per decade since 1986, they do not indicate a shift in local precipitation patterns. However, local farmers are nearly unanimous in their perception that precipitation has decreased, and the spatial patterns of glacier change (open full item for complete abstract)

Committee: Bryan Mark (Advisor); Michael Durand (Committee Member); W. Berry Lyons (Committee Member); Kendra McSweeney (Committee Member); Ellen Mosley-Thompson (Committee Member) Subjects: Climate Change; Geography; Hydrology; Latin American Studies; Physical Geography; Water Resource Management

Master of Science, The Ohio State University, 2012, Dentistry

The purpose of this study was to evaluate the fluid pressures during irrigation inside the root canal and at the apex. The study aimed to evaluate the fluid pressure with different depths, needle sizes, and irrigant flow rates both inside and at the apex of the model root. A Columbia dentoform (model: IV-EP-Endo # 8) incisor (Columbia Dentoform Corporation) was decoronated at the cement-enamel junction (CEJ) before being prepared to a #45/.02 size file at the apex. The model root was mounted and samples were run after placing a fiber optic fluid pressure sensor within the canal at the apex of the model root. Various needle designs and sizes were tested at varying depths within the canal and with varied fluid flow rates. The irrigation pressure inside the model root canal with the addition of ultrasonic energy was evaluated using the 25-gauge flat-ended ProUltra® PiezoFlow® ultrasonic irrigation needle. Air pressure was also evaluated by introducing air into the root canal with various irrigation needles. Sensor data was recorded and statistically analyzed. Results of this study were that, in general, as depth of the needle increased there was a statistically significant increase in pressure within the model root canal for almost all needle gauges, needle tip-designs, and flow rates. Irrigation pressure for the ultrasonic group showed a statistically significant increase in pressure as the ultrasonic needle tip was moved closer to the apex and a statistically significant increase in pressure with increasing flow rate. Although air pressure data was not statistically analyzed, pressure inside the root canal increased with increasing needle tip size.

Committee: John Nusstein DDS (Advisor); Al Reader DDS (Other); Melissa Drum DDS (Other); William Meyer DDS (Other); Michael Beck (Other) Subjects: Dentistry