Abnormal spatial heterogeneity governing the charge-carrier mechanism in efficient Ruddlesden-Popper perovskite solar cells

Layered Ruddlesden-Popper perovskite (RPP) photovoltaics have gained substantial attention owing to their excellent air stability. However, their photovoltaic performance is still limited by the unclear real-time charge-carrier mechanism of operating devices. Herein, we report the correlation between the charge-carrier mechanism and the spatially heterogeneous RPP bulks induced by distinct sublattice cations in the state-of-the-art antisolvent-driven RPP devices. In particular, abnormal heterogeneities ranging from the lateral long-range to local sub-grain scale and corresponding charge-carrier behaviours are visualized for triple-cation RPPs. We discovered that such heterogeneities with a unitary 2D/3D hybrid suppress lattice vibrations and reduce Frohlich interactions by about 2 times, significantly promoting charge-carrier dynamics. Consequently, optimized triple-cation RPP solar cells greatly outperform their mono-cation counterparts. Furthermore, this principle can be applicable irrespective of 2D layer thickness (n > 2) and substrate type. This work provides a rationale for leveraging a disordered structure to stimulate charge-carrier motion and suggests the design principle of low-dimensional perovskites.

INTEGRATED WATER RESOURCES MANAGEMENT IN A CHANGING CLIMATE: WATER QUALITY, QUANTITY, ALTERNATIVE, AND POLICY MAKING.

Land Use and Land Change (LULC) and climate variability are significant elements of the integrated water resources management to deal with water quality and quantity at the rural and urban interface. Adaptive strategies to develop sustainable water resources, therefore, are necessary to evaluate the water resources system in a changing global environment. In this dissertation, a series of analytical processes are implemented. First, gap filling processes are conducted by identifying a threshold of missing levels using daily precipitation series. The result indicates that about 15 % missing level of data is plausible to construct daily precipitation series for further hydrological analysis when the Gamma Distribution Function (GDF) is used as an estimation method. It is expected that such a finding can contribute to gap filling guidelines in the field, especially for water managers and hydrologists to take advantage of skillful estimates for missing daily precipitation data. Specifically, a gamma distribution function with statistical correlation (GSC) coupled with cluster analysis (CA) is used to estimate daily precipitation records and the result shows that GSC/CA outperformed other gap filling methods when rain and no-rain conditions are applied in the study area. Additionally, the dissertation identifies how Hydrological Simulation Program-Fortran (HSPF) model can improve performance depending on different sizes of watershed discretization levels within rainfall-runoff modeling settings. All simulations at different discretization levels above approximately 23% of the basin size resulted in satisfactory performances. However, the modeling performances are limited when the catchment size reaches below 8.18% of the basin size, regardless of automatic calibration efforts. The result indicates that basin discretization at finer scales does not necessarily improve HSPF simulation results with Next-Generation Radar (NEXRAD) inputs. Computer parallelism and spatio-temporal analysis is another avenue in this dissertation in the sense that the proposed method can advance hydrological simulations using HSPF along with different calibration scenarios. Thus, the result indicates that computer parallelism could save computation time up to 90%, while simulation improvement is achieved by 81%. This finding, therefore, will provide useful insights for hydrologists to design and set up their hydrological modeling exercises in a changing climate. As part of this dissertation, the evaluation of potential changes in water quality and quantity associated hydrologic changes in response to climate and LULC changes is also investigated. For example, HSPF model based on future LULC changes associated with climate scenarios was applied to generate climate-induced streamflow and to evaluate water quality in the Boise River Watershed (BRW). The result shows that the combined impact of LULC changes and climate variability on the BRW is inevitable, but seasonal variations in streamflow and water quality are primarily noticeable. This finding may provide useful information to develop sustainable water resources management when both water quality and quantity is an issue at the snow dominated watershed in a changing climate. Lastly, under the circumstance: increasing concerns on water quality associated with LULC changes and climate variability, identification of critical hot spots (CHSs) and the implementation of mitigation activities using low impact development (LID)/Best Management Practices (BMPs) is a critical exercise to improve water quality at the BRW. Based on preliminary environmental analysis using different methods, load per sub-area index (LPSAI) is selected as the most cost-effective method because it can reduce the average pollutant loads at the watershed outlet while minimizing cost.doctoral, Ph.D., Biological & Agricultural Engineering -- University of Idaho - College of Graduate Studies, 2017-0

Master's thesis recital (organ)

textL'ascension / O. Messiaen -- Messe pour les paroisses / F. Couperin -- Toccata, adagio and fugue in C major, BWV 564 / J. S. Bach -- Trois impressions, op.72 / S. Karg-Elert -- Symphony in E minor, op.20, no.2 / L. VierneMusi

A Study on Climate-Driven Flash Flood Risks in the Boise River Watershed, Idaho

We conducted a study on climate-driven flash flood risk in the Boise River Watershed using flood frequency analysis and climate-driven hydrological simulations over the next few decades. Three different distribution families, including the Gumbel Extreme Value Type I (GEV), the 3-parameter log-normal (LN3) and log-Pearson type III (LP3) are used to explore the likelihood of potential flash flood based on the 3-day running total streamflow sequences (3D flows). Climate-driven ensemble streamflows are also generated to evaluate how future climate variability affects local hydrology associated with potential flash flood risks. The result indicates that future climate change and variability may contribute to potential flash floods in the study area, but incorporating embedded-uncertainties inherited from climate models into water resource planning would be still challenging because grand investments are necessary to mitigate such risks within institutional and community consensus. Nonetheless, this study will provide useful insights for water managers to plan out sustainable water resources management under an uncertain and changing climate

Decision-Making of LID-BMPs for Adaptive Water Management at the Boise River Watershed in a Changing Global Environment

We conducted a study on water management at the Boise River Watershed in a changing global environment potentially induced by climate variability and urbanization. Environmental ‘hotspots’ associated with water quality and quantity were first identified to select suitable management options, such as Low Impact Development (LID is commonly used for urban storm water management to reduce impacts induced by flash flood in urban environment while improving water quality standard by filtering non-point source pollutants from predominant, impervious land segments in urban settings.) and Best Management Practices (BMPs) for urban and rural land segments, respectively. A decision-making process was employed to evaluate the cost-effectiveness for each management option based on multiple criteria, including water quality, financial challenges, and other environmental concerns. The results show that LID/BMPs were useful to control water quality in the watershed. The effectiveness of LID/BMPs implementation was subject to change with the placement location and consideration objectives associated with economic or environmental aspects. It appears that about 10% of the study area is required to implement water management options (LID/BMP) to improve water quality potentially driven by climate variability and urbanization. We anticipate that this study will make a case toward developing a sustainable water management plan in a changing global environment, especially for the urban–rural interface settings

The electrochemical analysis using critical parameters in Li-S battery

The electrochemically critical parameters in the Li-S battery, the overpotential (ΔV), the capacity from the dissolution region (Q1), and the capacity from the precipitation region (Q2), are identified to trace the electrochemical behavior of the electrode during the charge/discharge operation, which can aid in the deep understanding of the enhancement mechanism in the various model systems. The effects of cycling rate, conductive additive content, and oxygen functional group on the battery performance have been studied as the model systems. In this study, it is suggested that critical parameters should be carefully analyzed when exploring the performance of Li-S battery or designing batteries based on a new concept or novel architecture. © 2015 Korean Chemical Society, Seoul & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim2

Quantifying the Performances of the Semi-Distributed Hydrologic Model in Parallel Computing—A Case Study

The research features how parallel computing can advance hydrological performances associated with different calibration schemes (SCOs). The result shows that parallel computing can save up to 90% execution time, while achieving 81% simulation improvement. Basic statistics, including (1) index of agreement (D), (2) coefficient of determination (R2), (3) root mean square error (RMSE), and (4) percentage of bias (PBIAS) are used to evaluate simulation performances after model calibration in computer parallelism. Once the best calibration scheme is selected, additional efforts are made to improve model performances at the selected calibration target points, while the Rescaled Adjusted Partial Sums (RAPS) is used to evaluate the trend in annual streamflow. The qualitative result of reducing execution time by 86% on average indicates that parallel computing is another avenue to advance hydrologic simulations in the urban-rural interface, such as the Boise River Watershed, Idaho. Therefore, this research will provide useful insights for hydrologists to design and set up their own hydrological modeling exercises using the cost-effective parallel computing described in this case study

Practical outpatient pharmacotherapy for alcohol use disorder

Alcohol use disorder (AUD) is commonly encountered in clinical practice. A combination of psychosocial intervention and pharmacotherapy is the cornerstone of AUD treatment. Despite their efficacy, safety and cost-effectiveness, clinicians are reluctant to prescribe medications to treat individuals with AUD. Given the high rate of relapse with psychosocial intervention alone, increasing patient access to this underutilized treatment has the potential to improve clinical outcome in this difficult-to-treat population. Herein, we provide practical pharmacotherapy strategies to improve treatment outcome for AUD. We review the efficacy and side effects of both on- and off-label agents with a particular focus on clinical applicability. Recommendations are supported by findings from randomized controlled trials (RCT) and meta-analyses selected to be representative, where possible, of current treatment guidelines. The goal of this paper is to help readers use pharmacotherapy with greater confidence when treating patients with AUD

Impact of Demographic Changes on Inflation and the Macroeconomy

Ongoing demographic changes have brought about a substantial shift in the size and age composition of the population, which are having a significant impact on the global economy. Despite potentially grave consequences, demographic changes usually do not take center stage in many macroeconomic policy discussions or debates. This paper illustrates how demographic variables move over time and analyzes how they influence macroeconomic variables such as economic growth, inflation, savings and investment, and fiscal balances, from an empirical perspective. Based on empirical findings—particularly regarding inflation—we discuss their implications on macroeconomic policies, including monetary policy. We also highlight the need to consider the interactions between population dynamics and macroeconomic variables in macroeconomic policy decisions