EXPERIMENTAL CHARACTERIZATION AND MODELING OF ASPECT-RATIO-DEPENDENT DIFFUSION OF NANOCRYSTALS IN NANOCHANNELS

The investigation of aspect-ratio-dependent diffusion and equilibrium partitioning of semiconductor nanocrystals in rectangular nanochannels has been undertaken. The nanocrystals are terminated with hydrocarbon ligands and suspended in toluene, considered an aprotic solvent. Time-dependent concentration profiles are measured as a function of distance from the channel entrance by the calibrated fluorescence intensity of the nanocrystals. Both the forward diffusion of the nanocrystals and their reverse diffusion are characterized. Nanocrystals are first allowed to diffuse forward from a reservoir into the nanochannels over a long period ( 65 3 days) until the inlet concentration reaches a steady state. Subsequently, these nanocrystals are allowed to diffuse out, in reverse, from the nanochannels back into the reservoir that is filled with neat toluene. The experimentally observed concentration profiles during forward diffusion are compared to the profiles resulting from a continuum transport model accounting for diffusion and wall-adsorption of nanocrystals. The transport model provides estimates on the diffusion constant, equilibrium coefficients, and the adsorption/desorption rate constants. For the aspect ratios ranging from 1 to 6, the observed concentration within the nanochannels is significantly higher ( 65 x4) than the initial bulk concentration within the reservoir, indicating wall adsorption of nanocrystals. Despite the significant level of fluorescence intensity originating from the wall adsorbed NCs, the fractional surface coverage of nanocrystals remains below 1 monolayer. Using a two-site adsorption model, the diffusion constants from the forward diffusion profiles range from 10^-8 to 10^-9 cm^2 s^-1, while the adsorption rate coefficients range from 0.36 to 1.60 (x10^-15 cm^2 s^-1). In general, we observe an attractive van der Waals force between the NCs and the channel walls that allows for a reversible wall adsorption that strongly affects the apparent diffusion of NCs within nanochannels

An Experimental Investigation of a Light Weight High Voltage Power Supply

This investigation is directed toward the development and design of an electronic high-voltage power supply. The method consists of obtaining a direct current of low intensity by periodically charging by means of a primary battery a group of capacitors in parallel combination and discharging them electronically in series. A stimulus to this investigation is provided by the need for a light-weight electronic current source operating at moderately high voltages which is stable and capable of maintaining a constant current of low intensity over a wide range of variation of the potential from a primary battery. In addition, a power supply maintaining a constant output potential which is independent of large variations in the external temperature is desired. Tests run on a preliminary model designed by Dr. Victor Regener have indicated that thie project is possible

A CINEMATOGRAPHIC ANALYSIS OF THE FRONT HANDSPRING

The study of body mechanics has been around for ages, starting with Eadweard Muybridge, who studied body mechanics through cinematographic pictures. Understanding how the human body moves is important to many people, but especially to physical educators, for they are responsible for teaching young children and young adults how to perform specific sports motions. Ideally, physical educators should use cinematographic pictures to understand deeply the correct sequence of movements to execute the move, rather than attempting a trial and error type instruction. This thesis analyzes the execution of front handsprings cinematographically to determine the correct sequence of moves to execute a front handspring successfully

BLM’s National Greater Sage-Grouse Planning Strategy — What it Means for Montana

The Bureau of Land Management (BLM) is responsible for managing over 50% of the remaining Greater Sage-Grouse habitat throughout their range. In July, 2011 the BLM National Greater Sage-Grouse Planning Strategy was released as a supplement to the 2004 BLM National Sage-Grouse Habitat Conservation Strategy and the 2006 Western Association of Fish & Wildlife Agencies (WAFWA) Greater Sage-Grouse Comprehensive Conservation Strategy. This was in part due to the March 2010 petition decision by the U.S. Fish and Wildlife Service as “Warranted but Precluded” and settlement discussions between the FWS and Nongoverment Organizations (NGOs) over candidate species. The listing decision identified inadequate BLM regulatory mechanisms as a major factor in this decision. Principle regulatory mechanisms are conservation measures in Resource Management Plans (RMPs). Habitat for the Greater Sage-Grouse is found within five planning units in Montana. In December 2011 BLM issued instruction to offices on; 1) how BLM is to manage activities occurring within habitat for the Greater Sage-Grouse until RMPs amendments or revisions are completed, and 2) management actions and conservation options to be considered when developing RMP amendments or revisions. RMPs are to be completed or revised by December, 2014. This direction identifies actions for BLM programs with the potential to impact Greater Sage-Grouse. BLM is committed to reducing threats to Greater Sage-Grouse habitat on BLM lands in Montana through changes in management

Do air quality alerts reduce traffic? An analysis of traffic data from the Salt Lake City metropolitan area

posterThis research explores the unintended behavioral consequences on traffic volumes of the Air Quality Alert notification system in Salt Lake and Davis Counties, Utah

Examining the Relationship between Six Sigma Failures and the Utilization of Cost Engineering Approaches

The purpose of the quantitative non-experimental research study is to analyze the relationship between the impact of using cost engineering approaches and the success rate of Six Sigma projects in the manufacturing industry. This study focuses on the relationship between Six Sigma project failures and whether skilled cost engineering professionals, methods or a cost management system was used to ensure that accurate cost data was utilized during the design project\u27s lifecycle. Many companies using Six Sigma and related methodologies for product design have implemented with great success yet there are studies indicating that only 13% of firms reported achieving their annual profit objectives (Cooper, 2019; Guarraia, 2008). Researchers have found numerous critical failure factors associated with Six Sigma project failures but there is little research as to whether the underlying causes were related to the accuracy of cost estimate inputs required for manufacturing a product (Antony, Lizarelli, & Machado Fernandes, 2020). There is also an abundance of research studies that discuss critical success factors that support the increased likelihood of product design success so it is reasonable to assume that product design projects that failed may have neglected to implement these factors. Using a two-phase explanatory mixed-methods design that began with a nominal quantitative survey that included 177 Six Sigma practitioners responding to 26 questions. This phase was conducted to verify and validate the proposed research questions. Based on the analysis of the survey results a set of explanatory questions was developed for a qualitative semi-structured interview study that included nine subject matter experts recruited from the field of cost engineering (Creswell, 2015). Using thematic analysis, the responses from the interviews were then coded and categorized. After multiple iterations of analysis themes emerged allowing the researcher to develop a conclusion about the research question (V. Braun & V. Clarke, 2021). The results of this study indicate that the four themes, if implemented properly, can improve the failure rates for Six Sigma projects caused by cost related issues

Accuracy Assessment of Land Cover Maps Derived from Multiple Data Sources

Maximum Likelihood (ML) and Artificial Neural Network (ANN) supervised classification methods were used to demarcate land cover types within IKONOS and Landsat ETM+ imagery. Three additional data sources were integrated into the classification process: Canopy Height Model (CHM), Digital Terrain Model (DTM) and Thermal data. Both the CHM and DTM were derived from multiple return small footprint LIDAR. Forty maps were created and assessed for overall map accuracy, user\u27s accuracy, producer\u27s accuracy, kappa statistic and Z statistic using classification schemes from U.S.G.S. 1976 levels 1 and 2 and T.G.l.C. 1999 levels 2 and 4. Results for overall accuracy of land cover maps derived from multiple sources ranged from 13.67 to 57.56 percent for U.S.G.S. level 2 and T.G.l.C. level 4 across ML and ANN classifications. Results for overall map accuracy ranged from 26.00 to 72.33 percent for U.S.G.S. level 1 and T.G.I.C. level 2 across ML and ANN classifications. Land cover maps, derived using ML classification methodology, were consistently more accurate than land cover maps derived using an ANN classification algorithm

Rainbow Trout Spawning Characteristics and Relation to the Parasite Myxobolus cerebralis in the Missouri River, Montana

The myxosporean parasite Myxobolus cerebralis is responsible for significant declines of rainbow trout (Oncorhynchus mykiss) populations in several western states, including Montana. Despite a high prevalence of the parasite in Montana’s Missouri River, there have been no apparent impacts to the rainbow trout population. This study examined long-term M. cerebralis monitoring data from the Missouri River system below Holter Dam and evaluated rainbow trout spawning characteristics such as migration distance, spawning location, site fidelity and amount of spawning in the Missouri River and tributaries over three years in an attempt to explain why the population has not declined in the presence of M. cerebralis. Over 13 years of monitoring, a mean 5.3 percent of rainbow trout handled during population estimates had clinical signs of M. cerebralis infection. In experiments using sentinel fish 53 percent of the spawning habitat had high severity of M. cerebralis, 38 percent had low to moderate severity, and 9 percent had no infection. Radio telemetry showed spawning locations varied among years and tagged fish lacked spawning site fidelity. The distance that radio-tagged rainbow trout migrated to spawning locations was significantly different among river sections of the study area. Twenty-eight percent of the spawning redds were found in the Missouri River and 72 percent in the tributaries. Relative to previous studies, we found less tributary spawning and an increase in Missouri River spawning, where M. cerebralis infection severity is lower. Our findings suggest that diverse spawning behaviors may contribute to rainbow trout population stability by spreading the risk of M. cerebralis impact over spawning locations that have a broad range of infection severity

Pd-Catalyzed Conversion of Aryl Iodides to Sulfonyl Fluorides Using SO2 Surrogate DABSO and Selectfluor

A one-pot Pd-catalyzed conversion of aryl iodide to aryl sulfonyl fluorides using DABSO and Selectfluor has been developed generating aryl sulfonyl fluorides in good to excellent yields. The reaction results in the generation of electronically and sterically diverse sulfonyl fluorides. Additionally, sulfonyl fluorides can be converted to aryl sulfonamides and sulfonic esters using Cs2CO3 under mild conditions