Grapes (Vitis spp.), globally cultivated for wine and other grape-based products, are susceptible to various diseases, pests, and disorders. These challenges are particularly pervasive in Virginia and viticultural regions in similar climates. Thus, growers routinely use insecticides and fungicides to protect their fruits. However, frequent or excessive use of these chemicals can pose environmental and human health risks and increase the chances of fungicide resistance. Many crop production systems use physical barriers to shield plant surfaces from biotic and abiotic environmental factors, particularly in Asian countries. This study evaluated the efficacy of paper bags, umbrella-style covers, and fruit-zone shelters in mitigating fungal diseases, insect infestations, and other factors that damage grape clusters. A series of field experiments were conducted at four commercial vineyards in Virginia and one research experiment station at Virginia Tech in five years with eight grape cultivars. Our results highlighted the importance of bag and fruit-zone shelter applications. Especially when these protection measures were applied around bloom, we observed reductions in the level of multiple diseases and insect- and bird-related damages. Fruit bagging resulted in significantly lower (P ≤ 0.05) mean severity and incidence of black rot, sour rot, sooty mold, and grape berry moth damage. Similarly, we found a significantly lower mean incidence of black rot, ripe rot, sour rot, and bird damage with the application of fruit-zone shelters. Thus, fruit bagging and fruit-zone shelter can be an effective cultural method for safeguarding grape clusters from different diseases, potentially reducing pesticide use and offering economic advantages to growers. / Master of Science / Grapes are produced for making wine and other grape-based products worldwide. However, grape production often faces challenges from diseases, pests, and environmental factors, especially in humid regions like Virginia. Grape growers use pesticides (insecticides and fungicides) to protect their crops. However, these chemicals can harm the environment and human health; moreover, these disease organisms and pests can become resistant to pesticides. In many parts of the world, especially in Asia, farmers use physical barriers like bags or covers to protect their crops from various harmful factors. In this study, we tested the effectiveness of paper bags, umbrella-style covers, and special shelters around the fruit area of grape plants against fungal diseases, insect problems, and other damages. We conducted a series of experiments over five years in four commercial vineyards and a research station in Virginia, using eight grape cultivars. Our findings showed that using bags and shelters around the grapes, especially during the blooming period, was effective. Bagging the fruit led to significantly fewer cases of diseases (black rot, sour rot, and sooty mold) and grape berry moth damage. Likewise, using shelters around the fruit area resulted in significantly lower diseases (black rot, ripe rot, and sour rot) and bird damage. Therefore, these protective methods could offer more options for grape growers to protect yield from factors damaging their high-value crops.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23873号 / 工博第4960号 / 新制||工||1775(附属図書館) / 京都大学大学院工学研究科建築学専攻 / (主査)教授 大崎 純, 教授 池田 芳樹, 准教授 藤田 皓平 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Uppsatsen analyserar Sara Lövestams och Per Gustavssons bilderbok Under mattan (2018). Bilderboken är skriven utifrån det idiomatiska uttrycket "att sopa något under mattan" och den illustrerar vad som faktiskt händer, bokstavligt talat, om vi sopar in allt möjligt under mattan. Syftet med analysen är att undersöka om och hur de vuxnas brister framställs samt hur relationen mellan barn och vuxna skildras. Uppsatsens metod utgår från bland annat Ulla Rhedins bilderbokskoncept. Ytterligare metoder som använts är närläsning och ikonotext samt analys av karaktärer. Analysen visar att föräldrarna i bilderboken brister i sin vuxenroll samtidigt som barnet tar mer ansvar och växer in i rollen som det kompetenta barnet. Relationen mellan barnet och de vuxna är spänd samt speglar den makt vuxna har över barn i samhället idag. De vuxnas brister blir synliga både i bild och text, där bilden vid flera tillfällen förstärker textens budskap. Under mattan har potential att användas i undervisningen med både äldre och yngre elever och berättelsen har flera nivåer som går att anpassa utefter elevgruppens ålder och mognad.

Assessments of chemical health risks are performed by scientific experts. Their intended use is as bases for decisions. This thesis tries to answer the questions of how uncertainty is, and should be, communicated in such risk assessments. The thesis consists of two articles and an introductory essay. Article I focuses on the linguistic aspect of the communication of uncertainty in risk assessments. The aim of the article is to elucidate how risk assessors actually indicate uncertainty in risk assessment reports. Because of the prevalent uncertainty in risk assessment, deriving from several sources, uncertainty is communicated in verbal, rather than numerical terms. A typology of uncertainty indicators – phrases used to express uncertainty – is proposed and applied to the reviewed reports. It is found that the use of such phrases is not transparent, and the article concludes by a number of recommendations for improving the practice. Article II mainly deals with the content of the communication. The overall question treated is what a characterization of uncertainty should include if a decision made on the basis of the risk assessment information is to be as well-founded as possible. A set of conditions is put forward to be fulfilled by a characterization of uncertainty if it is to be adequate from a decision-making point of view. The greater part of the introductory essay is devoted to the concept of uncertainty which, at the conceptual level, does not appear to have been much discussed by philosophers / QC 20101208

With the advent of the No Child Left Behind legislation and the culture of standards-based education that it brings, it is imperative for educators to focus on the academic growth of students. Indeed, the nation's schools, school districts, and states are being held accountable for student achievement. Administrators in numerous school districts across the United States have implemented a popular reform initiative, Site-Based Management SBM), to improve student achievement. District leaders must examine the efficacy of SBM, where the authority, autonomy, and responsibility for student learning are devolved to the school level, to ensure that SBM is yielding intended results and to ensure fidelity of its implementation. This study examined principal perceptions and implementation of SBM in the Prince William County School District in Virginia after 19 years of implementation. The investigator administered an SBM survey to a population of all 86 principals in the school district. Of those, 78 completed at least part of the survey, for a return rate of 91%. The study focused on the perceptions of principals under SBM and their implementation of SBM as defined by the functions of the School Advisory Council and the shared decision-making processes used at the school level. Variables of the study were principals' years of experience with SBM and the grade level at which they work. Principals reported positive perceptions of SBM, in particular, the perception that SBM contributes to improvements in student achievement and to a climate of enhanced stakeholder satisfaction. A third of the principals indicated that SBM requires principals to spend too much time on administrative tasks. Principals with more than 10 years of experience reported more positive perceptions than principals with zero to three years experience with SBM. Principals reported that School Advisory Councils spend the most time developing, monitoring, and evaluating the school plan. Principals' years of experience with SBM were not related to the functions of their School Advisory Council, but principals with more than ten years of experience with SBM indicated a significantly higher use of consensus as a shared decision-making process. No significant relationship was found between the school level at which principals work and their perceptions of SBM. While not significant, middle school principals rated the School Advisory Council function of aligning the school budget with the school plan slightly higher than principals at other levels. There was no relationship between principals' school level and their use of shared decision-making processes. Principals reported strengths of SBM to be autonomy in making instructional decisions; flexibility with budget; building teacher leaders; and shared decision making. Challenges to the successful implementation of SBM were budget issues; too much time away from instructional focus; and the need for ongoing training. / Ed. D.

One key outcome of this research is the design for a 3-D tractor-trailer base-drag reduction device that predicts a 41% reduction in wind-averaged drag coefficient at 57 mph (92 km/h) and that is relatively insensitive to uncertain wind speed and direction and uncertain deflection angles due to mounting accuracy and static aeroelastic loading; the best commercial device of non-optimized design achieves a 12% reduction at 65 mph. Another important outcome is the process by which the optimized design is obtained. That process includes verification and validation of the flow solver, a less complex but much broader 2-D pathfinder study, and the culminating 3-D aerodynamic shape optimization under uncertainty (OUU) study. To gain confidence in the accuracy and precision of a computational fluid dynamics (CFD) flow solver and its Reynolds-averaged Navier-Stokes (RANS) turbulence models, it is necessary to conduct code verification, solution verification, and model validation. These activities are accomplished using two commercial CFD solvers, Cobalt and RavenCFD, with four turbulence models: Spalart-Allmaras (S-A), S-A with rotation and curvature, Menter shear-stress transport (SST), and Wilcox 1998 k-ω. Model performance is evaluated for three low subsonic 2-D applications: turbulent flat plate, planar jet, and NACA 0012 airfoil at α = 0°. The S-A turbulence model is selected for the 2-D OUU study. In the 2-D study, a tractor-trailer base flap model is developed that includes six design variables with generous constraints; 400 design candidates are evaluated. The design optimization loop includes the effect of uncertain wind speed and direction, and post processing addresses several other uncertain effects on drag prediction. The study compares the efficiency and accuracy of two optimization algorithms, evolutionary algorithm (EA) and dividing rectangles (DIRECT), twelve surrogate models, six sampling methods, and surrogate-based global optimization (SBGO) methods. The DAKOTA optimization and uncertainty quantification framework is used to interface the RANS flow solver, grid generator, and optimization algorithm. The EA is determined to be more efficient in obtaining a design with significantly reduced drag (as opposed to more efficient in finding the true drag minimum), and total predictive uncertainty is estimated as ±11%. While the SBGO methods are more efficient than a traditional optimization algorithm, they are computationally inefficient due to their serial nature, as implemented in DAKOTA. Because the S-A model does well in 2-D but not in 3-D under these conditions, the SST turbulence model is selected for the 3-D OUU study that includes five design variables and evaluates a total of 130 design candidates. Again using the EA, the study propagates aleatory (wind speed and direction) and epistemic (perturbations in flap deflection angle) uncertainty within the optimization loop and post processes several other uncertain effects. For the best 3-D design, total predictive uncertainty is +15/-42%, due largely to using a relatively coarse (six million cell) grid. That is, the best design drag coefficient estimate is within 15 and 42% of the true value; however, its improvement relative to the no-flaps baseline is accurate within 3-9% uncertainty. / Ph. D.

The effect of ice damage on loblolly pine (Pinus taeda) plantations in the Piedmont region of Virginia was examined to discover if management decisions can minimize net present value losses. A simulation approach was used for the analysis. Loblolly pine plantations were simulated using the growth and yield model, Trulob. Ice damage was factored into the model using prediction equations from a previous study. A decision tree framework was used to determine which management plans resulted in the highest net present value. The results show that ice storms can cause significant losses to the net present value of loblolly plantations. In most instances changing management plans could not minimize losses. In situations where altering management plans can result in higher net present values if ice occurs, landowners should also be aware of the suboptimal net present value they will be returned if these plans are followed and no ice storms occur. / Master of Science

Yes / A mature oil field rescaled contraction describes a switch to a technological alternative more appropriate for the depleted state of an underlying resource. Off-shore oil rigs are an illustration, since the original technological scale designed for very large output flows becomes inappropriate as the operational efficiency declines later in life and facing a dwindling output flow, so a more appropriate extraction technology becomes economic. A real option representation is formulated on a stochastic oil price and deteriorating output volume. We consider investment/divestment decisions both separately, and jointly, which have different implications for government policies and also option values. The resulting model yields analytical (or semi-analytical) results indicating that immediate switching to the lower cost technology could sometimes be hastened as the price volatility increases, depending on the current revenue, if divestment and switching are considered jointly. However, greater volatility could also promote hysteresis.

<p dir="ltr">A broad scope of this dissertation is to verify that a nearby loss of generation event in power system can be distinguished from similar remote disturbances by analyzing the resulting local modes of oscillation. An oscillation-based index derived from methods like Fourier transform, sinc filters and resonant filters is devised and experimented in combination with a variant of df/dt index to jointly classify if a loss of generation event is nearby or remote. A phenomenon widely observed during a loss of generation event is the average decrease in the system’s frequency, typically monitored using the df/dt index. Under-frequency load-shedding (UFLS) relays that are based on df/dt are highly likely to trip for nearby frequency events when combined with the oscillation-based index we propose. Nearby in our context refers to geographical distance, which is correlated with electrical distance, and includes buses within about 50-100 miles of the event location.</p>

The problem of this study was to determine the relationship between chronological age and reading achievement and between chronological age and personality development in school children.