Soybean is an important source of protein in animal feed, and growing demand for meat consumption worldwide has led to increased soybean production. Over 120 million metric tons of soybean were harvested in the United States in 2018, approximately one-third of the world production. In the Mid-Atlantic region, soybean is one of the most valuable field crops. Major foliar diseases that reduce soybean yield in the Mid-Atlantic region are frogeye leaf spot (FLS) and Cercospora leaf blight. In addition to crop rotation and host resistance, foliar fungicides, often with quinone outside inhibitor (QoI) active ingredients, are used to manage these soybean foliar diseases. Yield benefits of foliar fungicides have been inconsistent and this may be the result of low disease pressure, unfavorable environmental conditions for disease development, or the presence of fungal pathogen populations that have developed resistance to fungicides. The objectives of this research were 1) to develop a pyrosequencing-based assay to rapidly quantify QoI resistance frequencies in Cercospora sojina, the causal agent of FLS, 2) to examine the effects of fungicide application timings, disease pressure, and environmental factors on soybean yield, and 3) to develop a weather-based soybean foliar fungicide application decision aid for the Mid-Atlantic U.S. using a threshold decision rule. A pyrosequencing assay targeting the G143A mutation was designed, and a Virginia survey of C. sojina populations indicated that the G143A mutation conferring QoI resistance is widespread. In small plot fungicide application timing experiments, five weekly fungicide applications starting at beginning pod (R3) resulted in the greatest yield, but for single fungicide applications, R3 or 1 week after R3 resulted in the greatest yields. There was positive relationship between the cumulative number of disease favorable days (mean daily temperature 20-30°C and ≥ 10 hours of relative humidity >90%) from planting to R3 and disease severity at the full pod stage (r = 0.97, P = <0.01). Higher disease severity was associated with greater yield loss (r2 =0.53, P = 0.10) suggesting foliar fungicide applications are more likely to have yield benefits as the number of disease favorable days prior to R3 increase. A disease favorable-days threshold (FDT) using the environmental parameters indicated above was evaluated in on-farm experiments throughout Virginia, Maryland, and Delaware. Based on decision rules, FDT = 8 three weeks prior to R3 was the best predictor of a yield benefit with an R3 fungicide application. The decision aid was also able to correctly predict when a fungicide application would not be profitable ≥90% of the time. This weather-based decision aid along with monitoring of fungicide resistance development within the region will provide soybean growers in the Mid-Atlantic U.S. with tools to maximize yields and profitability. / Doctor of Philosophy / Soybean is the third most valuable field crop in the world, ranked only behind rice and wheat in value. Over 98% of the soybean crop is used for animal feed due to its high protein content. The United States is the largest soybean producer in the world, responsible for one-third of global production. Soybean is the top cash crop in the Mid-Atlantic region. Foliar fungal diseases can reduce the soybean yield by causing lesions on the leaves that reduce photosynthesis and cause premature defoliation. Frogeye leaf spot (FLS) caused by Cercospora sojina is a major yield reducing soybean foliar diseases in the Mid-Atlantic region. Foliar fungicides, often with quinone outside inhibitor (QoI) active ingredients, are used to manage the disease. However, fungicide efficacy has been inconsistent. Inconsistencies may be due to low disease pressure, improper application timing, or fungicide resistance. The purpose of this research was to investigate the fungicide efficacy inconsistencies and to develop management tools to improve yield and maximize profitability. Our objectives were to 1) develop a molecular assay to quantify frequencies of the mutation conferring fungicide resistance in Virginia populations of C. sojina, 2) examine the effects of fungicide application timings, disease severity, and weather on soybean yield, and 3) develop a weather-based soybean foliar fungicide application decision aid for the Mid-Atlantic U.S. The C. sojina fungicide resistance mutation was widespread in Virginia, but overall frequencies were relatively low compared to findings from Midwest and Southern states. In fungicide timing experiments, beginning pod (R3) applications resulted in the most consistent yield benefits, and disease severity and yield loss increased as the number of weather-based disease favorable days prior to R3 increased. We used data from on-farm experiments in Virginia, Maryland, and Delaware to develop a weather-based disease favorable-days threshold that increased the probability that a fungicide application at R3 would have a yield benefit in soybean. The results of our research have led improved fungal disease management recommendations for soybean in the Mid-Atlantic that will maximize yields and profitability.

The United States is a world leader of soybean [Glycine max (L.) Merr.] production, but to maintain quality production at this level, soybean management needs to be continually monitored and improved. Sulfur (S) deficiencies in soybean have become more frequent in the U.S. due to fertilizer purity, emissions regulations, and higher yields. We completed a study for soybean grown in sandy loam soils in the mid-Atlantic coastal plain system to determine proper S fertilizer rate and application timing. Yields ranged from 1,236-4,051 kg ha-1. Neither S rate nor application timing influenced yield. S treatments increased methionine concentration (methionine = -0.0001 S rate2 + 0.002 S rate + 5.60). Sulfur fertilization can improve soybean quality and may impact marketability. Another study was conducted to determine optimal source and rate of S application for soybeans in the Mid-Atlantic coastal plain system. Yields ranged from 1,316-4,914 kg ha-1. While sulfur rate did not influence yield and fertilizer source responses were site-specific. Sulfur leaf tissue concentrations were directly related to S rate (S concentration = 0.004S rate + 2.103). Nutrient uptake responses to S fertility indicate the potential for S yield responses in the future when soils become S depleted and contain less available S. Soybean producers and retailers in the United States are interested in capitalizing on new edamame markets to provide a domestic product. To aid the shift from oilseed production to vegetable production, a study was conducted to determine the optimal N rate and N application timing for edamame yield and quality in the Mid-Atlantic coastal plain system. Nitrogen rate significantly increased yield one out of three years (Yield = 29.9N Rate + 3387) when all N was applied at planting but was not significant with split applications. Fertilizer rate and timing did not impact edamame maturity or final pod/bean quality. N fertilizer applied at-planting may aid edamame yield and profit for sandy loam soils in the mid-Atlantic, USA. Currently, mid-Atlantic coastal plain soils, coupled with S deposition, are able to supply enough S for soybean growth and development, but without fertilization soybean soils are being mined of S and will eventually become depleted. Sulfur must be monitored if future deficiencies are to be avoided. Nitrogen fertilizers may improve yield in vegetable soybean production. Both oilseed and vegetable soybean farmers should continue to monitor soil nutrient levels to ensure proper nutrition for soybean growth and development. / Doctor of Philosophy / Soybean (Glycine max L. [Merr.]) is a diverse crop used across various industries: from vegetables for human consumption to protein for animal feed or even additives for roofing sealants. The U.S. is a world leader in soybean production. To maintain quality production at this level, soybean management needs to be continually monitored and improved. Sulfur (S) and nitrogen (N) fertilizers are one current area of interest in soybean production and management. This dissertation will discuss both. Historically, acid rain, which contained high levels of S, provided all the necessary S for proper soybean growth and development. In recent years, industry emissions regulations have decreased the amount of S entering the air, thereby decreasing S deposits in acid rain. At the same time, soybean yields are increasing, and higher production requires higher amounts of inputs. Therefore, because S is a necessary input, it is being taken from the soil to meet the needs of high yielding soybean. Less and less S remains in the soil for future soybean crops. This study was conducted to determine proper sulfur fertilizer applications, to ensure quality and quantity soybean production for Virginia farmers. Yields ranged from 1,236-4,914 kg ha-1. Currently, soils contain sufficient S levels for proper growth and development, but if current trends persist sulfur deficiencies will become apparent in the future. Although the U.S. soybean production is abundant, most of the vegetable soybean, also called edamame, consumed in U.S. is imported. The interest in providing a domestic edamame product has led soybean farmers to reevaluate and adapt soybean production strategies to fit a vegetable crop. Edamame is the same species as oilseed soybeans commonly grown throughout the US, but instead of waiting until the seed is dry, edamame is harvested when the seed is still green. This study also was conducted to provide nitrogen fertilizer recommendations for Virginia soybean farmers hoping to adjust their farms to produce quality vegetable soybean. Nitrogen fertilizer improved edamame gross production one out of three years. Continual observation of soil nutrient levels and soybean health is necessary to ensure quality growth and production for both oilseed and vegetable soybean.

Consecutive traffic signals produce vehicle stops and acceleration/deceleration maneuvers on arterial roads, which may increase vehicle fuel consumption levels significantly. Eco-cooperative adaptive cruise control (Eco-CACC) systems can improve vehicle energy efficiency using connected vehicle (CV) technology. In this thesis, an Eco-CACC system is proposed to compute a fuel-optimized vehicle trajectory while traversing multiple signalized intersections. The proposed system utilizes signal phasing and timing (SPaT) information together with real-time vehicle dynamics data to compute the optimal acceleration/deceleration levels and cruise speeds for connected-technology-equipped vehicles while approaching and leaving signalized intersections, while considering vehicle queues upstream of the intersections. The INTEGRATION microscopic traffic simulation software was used to conduct a comprehensive sensitivity analysis of a set of variables, including different levels of CV market penetration rates (MPRs), demand levels, phase splits, offsets, and distances between intersections to assess the benefits of the proposed algorithm. Based on the analysis, fuel consumption saving increase with an increase in MPRs and a decrease in the cycle length. At a 100% equipped-vehicle MPR, the fuel consumption is reduced by as much as 13.8% relative to the base no Eco-CACC control. The results demonstrate an existence of optimal values for demand levels and the distance between intersections to reach the maximum fuel consumption reduction. Moreover, if the offset is near the optimal values for that specific approach, the benefits from the algorithm are reduced. The algorithm is limited to under-saturated conditions, so the algorithm should be enhanced to deal with over-saturated conditions. / Master of Science

The Hybrid Electric Vehicle Team (HEVT) at Virginia Tech participates in the 4-Year EcoCAR Mobility Challenge organized by Argonne National Laboratory. The objective of this competition is to modify a stock 2019 internal combustion engine Chevrolet Blazer and incorporate a hybrid powertrain and advanced driver assist systems. The Blazer has a P4 hybrid architecture which contains an electric traction motor on the rear axle and an internal combustion engine on the front axle. HEVT seeks to develop a vehicle with advanced driving capabilities to demonstrate energy savings by utilizing existing technologies. The hybrid market has generally been tailored to small compact vehicles however, a Chevrolet Blazer is a midsize utility vehicle that offers additional space with the benefit of increased fuel economy. The research discussed in this paper focuses on the design of a Signalized Intersection Control Strategy. First, research is performed on different methods of intersection control and implementation with an existing Model Predictive Adaptive Cruise Controller. Based on ease of integration into an existing tuned Eco Adaptive Cruise Control System (ACC), a control strategy operating in the background of the main vehicle controllers is chosen. The main topic of this research is the development and simulation of a Signalized Intersection Control Strategy that works through an Eco ACC system to achieve further energy savings during an approach to a connected intersection while ensuring rider safety. This paper expands on the current knowledge of vehicle utilization of Signal Phase and Timing (SPaT) signals through simulated test cases of a vehicle system model using MATLAB. In each case, the tractive energy consumption and travel times are analyzed for both the Eco ACC system with Signalized Intersection Control Strategy (informed) vehicle and an assumed uninformed driver for comparison. In the case of a vehicle approaching a green intersection which turns red several seconds after SPaT information is received, the informed system shows a 92% decrease or 75 Wh/mi reduction in propel energy consumption at when compared to an uninformed driver. However, in a similar case where the vehicle accelerates back to cruising speed after the light turns green, displays only an 11% decrease or 47 Wh/mi reduction in propel energy consumption at the wheel when compared to the uninformed driver. These simulations confirm that the Signalized Intersection Control Strategy reduces the propel energy consumption at the wheel during approaches to signalized intersections without extending the travel time greatly and in some cases at all. The results of this research show that the control strategy reduces tractive energy consumption while maintaining travel time. / Master of Science / The Hybrid Electric Vehicle Team (HEVT) at Virginia Tech participates in the 4-Year EcoCAR Mobility Challenge organized by Argonne National Laboratory. The objective of this competition is to change a stock 2019 internal combustion engine Chevrolet Blazer into a functioning hybrid. This conversion is accomplished with the addition of an electric motor to allow the vehicle to burn less gasoline and increase customer appeal. The hybrid market has generally been tailored to small compact vehicles however, a Chevrolet Blazer is a midsize utility vehicle that offers additional space with the benefit of increased fuel economy. The research discussed in this paper focuses on the design of a Signalized Intersection Control Strategy. First, research is performed on various methods of existing intersection speed control. Based on ease of integration, a background process is chosen to update the set speed of the vehicle. The main topic of this research is the development and simulation of a Signalized Intersection Control Strategy that achieves greater energy savings during approaches to intersections. This paper expands on the current knowledge of vehicle utilization of Signal Phase and Timing (SPaT) signals through simulated test cases of a vehicle system model using MATLAB. In the case of a vehicle approaching a green intersection which turns red several seconds later, the implemented strategy shows a 92% decrease in energy consumption when compared to an uninformed driver. However, a similar case where the vehicle accelerates back to cruising speed after the light turns green displays only an 11% decrease in energy consumption when compared to an uninformed driver. These simulations confirm that the Signalized Intersection Control Strategy successfully reduces energy consumption without significant travel time extensions. The results of this research show that the control strategy reduces tractive energy consumption while maintaining travel time.

Yes / Accurate time perception is critical for a number of human behaviours, such as understanding speech and the appreciation of music. However, it remains unresolved whether sensory time perception is mediated by a central timing component regulating all senses, or by a set of distributed mechanisms, each dedicated to a single sensory modality and operating in a largely independent manner. To address this issue, we conducted a range of unimodal and cross-modal rate adaptation experiments, in order to establish the degree of specificity of classical after-effects of sensory adaptation. Adapting to a fast rate of sensory stimulation typically makes a moderate rate appear slower (repulsive after-effect), and vice versa. A central timing hypothesis predicts general transfer of adaptation effects across modalities, whilst distributed mechanisms predict a high degree of sensory selectivity. Rate perception was quantified by a method of temporal reproduction across all combinations of visual, auditory and tactile senses. Robust repulsive after-effects were observed in all unimodal rate conditions, but were not observed for any cross-modal pairings. Our results show that sensory timing abilities are adaptable but, crucially, that this change is modality-specific - an outcome that is consistent with a distributed sensory timing hypothesis.

Yes / This paper presents the development and implementation of an Analytical Target Cascading (ATC) Multi-disciplinary Design Optimisation (MDO) framework for the steady state engine calibration optimisation problem. The case is made that the MDO / ATC offers a convenient framework for the engine calibration optimisation problem based on steady state engine test data collected at specified engine speed / load points, which is naturally structured on 2 hierarchical levels: the “Global” level, associated with performance over a drive cycle, and “Local” level, relating to engine operation at each speed / load point. The case study of a gasoline engine equipped with variable camshaft timing (VCT) was considered to study the application of the ATC framework to a calibration optimisation problem. The paper describes the analysis and mathematical formulation of the VCT calibration optimisation as an ATC framework, and its Matlab implementation with gradient based and evolutionary optimisation algorithms. The results and performance of the ATC are discussed comparatively with the conventional two-stage approach to steady state calibration optimisation. The main conclusion from this research is that ATC offers a powerful and efficient approach for engine calibration optimisation, delivering better solutions at both “Global” and “Local” levels. Further advantages of the ATC framework is that it is flexible and scalable to the complexity of the calibration problem, and enables calibrator preference to be incorporated a priori in the optimisation problem formulation, delivering important time saving for the overall calibration development process. / The research work presented in this paper was funded by UK Technology Strategy Board (TSB) through the CREO (Carbon Reduction through Engine Optimisation) project.

Yes / Dual-fuel HCCI engines allow a relatively small quantity of diesel fuel to be used to ignite a variety of fuels such as natural gas or methane in HCCI mode. The gaseous fuel is mixed with the incoming air, and diesel fuel is sprayed into the cylinder by direct injection. Mathematical modelling is used to investigate the effects of parameters such as premixed ratio (fuel ratio) and pilot fuel injection timing on combustion of a dual-fuel HCCI engines. A CFD package is used with AVL FIRE software to simulate dual-fuel HCCI combustion in detail. The results establish a suitable range of premixed ratio and liquid fuel injection timing for low levels of NOx, CO and HC emissions along with a reliable and efficient combustion. Dual-fuel HCCI mode can increase NOx emission with lower premixed ratios in comparison to normal HCCI engines, but it is shown that the NOx emission reduces above a certain level of the premixed ratio. Due to the requirement of homogenous mixing of liquid fuel with air, the liquid fuel injection is earlier than for diesel engines. It is shown that, with careful control of parameters, dual-fuel HCCI engines have lower emissions in comparison with conventional engines.

Denna uppsats utforskar och analyserar kapitalstrukturen hos börsnoterade fastighetsbolag på Nasdaq Stockholm under åren 2017–2022. Studien fokuserar på att identifiera eventuella samband mellan bolagens skuldsättningsgrad och en rad faktorer: storlek, lönsamhet, tillväxt, samt styrräntans inverkan under den valda tidsperioden. Genom att analysera dessa faktorer i relation till den rådande ekonomiska miljön, avser studien att ge insikter i hur fastighetsbolagen kan utforma sina strategier inför framtida finansiella fluktuationer. Den teoretiska ramen inkluderar grundläggande kapitalstrukturteorier som Modigliani-Miller, Trade-off Theory, Pecking order Theory och Market Timing Theory. Med dessa teorier som grund, har studien utfört kvantitativ dataanalys för att testa hypoteser om sambanden mellan de oberoende variablerna (storlek, lönsamhet, tillväxt, styrränta och TestEtt), och den beroende variabeln (skuldsättningsgrad). Dessa insikter är inte bara relevanta för akademiska ändamål utan också värdefulla för investerare och företagsledare i beslutsprocessen om investeringar. Studien bidrar till den befintliga forskningen genom att ge en djupare förståelse för hur externa ekonomiska förhållanden, som förändrade styrräntor, påverkar kapitalstrukturer inom fastighetssektorn. Slutligen presenterar uppsatsen förslag för framtida forskning för att bygga vidare på de upptäckta trenderna och relationerna. / This essay explores and analyzes the capital structure of publicly traded real estate companies on Nasdaq Stockholm during the years 2017–2022. The study focuses on identifying potential correlations between the companies' leverage ratios and a range of factors: size, profitability, growth, as well as the impact of the policy rate during the chosen period. By analyzing these factors in relation to the prevailing economic environment, the study aims to provide insights into how real estate companies can shape their strategies in anticipation of future financial fluctuations. The theoretical framework includes fundamental capital structure theories such as Modigliani-Miller, Trade-off Theory, Pecking order Theory, and Market Timing Theory. Building on these theories, the study conducted quantitative data analysis to test hypotheses regarding the relationships between the independent variables (size, profitability, growth, policy rate and TestEtt) and the dependent variable (leverage ratio).  These insights are not only relevant for academic purposes but also valuable for investors and corporate decision-makers in the investment decision-making process. The study contributes to existing research by providing a deeper understanding of how external economic conditions, such as changing policy rates, affect capital structures within the real estate sector. Finally, the essay presents suggestions for future research to build upon the discovered trends and relationships.

Emerging adults hold a variety of motivations and perceived views of parenthood. With many new parents struggling to balance parenthood, relationships, and careers, it is reasonable to question individuals' motivation and perceived views of parenthood. Research shows that emerging adults hold parenting motivations, future career expectations, and expectations about children that may be related to their perceived views of parenthood. Thus, to further understand the predictors of future parenting attributions, the current study examined the relationships among the motivation to become a parent, future role expectations, interpersonal relationships, and parenting attributions. One hundred forty-three college undergraduates who were not already parents completed a packet of questionnaires including measures of the variables described above. Result of this study indicated that the variables examined in this study demonstrated interesting relationships and that the motivation to parent served as an important predictor of individuals' attributions for perceived parent control over success in parent-child interactions. These findings emphasize the importance of research that can identify the best ways to assist emerging adults in planning for parenthood in the future.

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality among young children and adults. This primary injury initiates an inflammatory response that may lead to a secondary brain injury. Nursing care in the critical care setting supports prevention or reduction of secondary injury through control of intracranial pressure (ICP), mean arterial pressure (MAP), and the subsequent cerebral perfusion pressure (CPP). While secondary injury may be preventable, some nursing interventions may contribute to increased ICP and decreased CPP. Patients with increased ICP or decreased CPP are at risk for poor clinical outcomes. This literature review examined the effort of routine nursing care interventions on outcomes of TBI patients in the critical care setting. Eleven research articles studying head of bed elevation, head and neck positioning, turning, and spacing of patient care activities were the focus of the analysis. Results typically showed positive outcomes by elevating the head of the bed to thirty degrees. CPP was also maintained at thirty degrees, but showed varied results. ICP and CPP are best controlled with the head and neck in a neutral position. Turning patients is a routine nursing intervention that contributes to increased ICP in some positions in some patients. Most studies suggest ICP is lowest in the supine position and highest in the left lateral position, but differences in findings were noted. Providing basic nursing care interventions in close succession also may contribute to increases in ICP in some patients. Results from this review provide evidence to support the importance of assessing and planning care for each TBI patient individually. It is hoped that findings from this review will provide guidance for bedside nurses to improve clinical practice and drive future research to support best practices for care of patients who suffer TBI.