GOALI: Multicomponent Molecular Transport in Nanoporous Materials

In recent years novel diffusion controlled catalytic processes and non-conventional separation processes such as adsorption and membrane processes have gained an increasingly important place in the petroleum and petrochemicals industries. Several factors have driven this trend, including the need to improve the energy efficiency and throughput of refineries, stricter limits on the allowable composition of gasoline and diesel fuel requiring the removal of aromatics and sulfur containing compounds to extremely low levels, the need to process increasingly complex deposits of both natural gas and liquid hydrocarbons, and the possibility of producing liquid fuels from non-traditional sources such as biomass. Although progress has been made, significant challenges remain. Most of the newer processes have been developed by extensive trial and error experimentation with only limited attempts to develop a fundamental understanding of the underlying phenomena. This project is a three-year, three-way research program involving the University of Maine (UMaine), Carnegie Mellon University (CMU), and ExxonMobil Corporation (EM) to study molecular transport in nanoporous materials of industrial interest. A major objective is to develop a fundamental understanding of how the transport properties are modified in multicomponent systems due to interference effects. The proposed collaboration will produce a more fundamental understanding of the major factors that control intracrystalline diffusion in multicomponent systems under sterically hindered conditions. This knowledge will provide a valuable platform for the development of new adsorption processes and the optimization of existing processes. The proposed research will directly impact existing efforts to develop a robust process for upgrading CO2-rich natural gas and to develop the methanol to olefins (MTO) process to the point of economic viability. By its collaborative nature, the work will address two major defects in previous studies of molecular transport in nanoporous materials: (1) The conditions of the (past) experimental studies are often far removed from conditions of practical interest and (2) The integration between experimental and molecular modeling studies has generally involved post facto comparisons of results, rather than an integrated collaborative program of research. The projects overall aim is to generate the underlying science needed to develop the nanoporous adsorbents, membranes, and catalysts required for advanced catalytic and/or separation processes of importance to the petrochemical industries. The students working on the project will benefit from in-depth research training and outstanding research facilities at the two universities and at EM. EM is providing cost free access to the research and technical facilities at their Clinton N.J. laboratory, half the time of one research professional for project supervision, a part time post-doc or research technician to work with the students, support for the students living expenses while at Exxon Mobil and partial summer salaries for Ruthven and Sholl. The nations science and engineering workforce will be strengthened through student participation in industrial research and the integration of research results into courses at UMaine and CMU

Effect of Vegetation on the Ontogeny to Piscivory in Juvenile Largemouth Bass

Largemouth Bass (Micropterus salmoides) are an economically important gamefish species in North America and as such are a focal species for managers. A frequent bottleneck to their recruitment is overwinter survival in their first year of life. Early ontogeny to piscivory provides increased overwinter survival through growth and accumulation of lipids. This ontogeny is slowed by dense and complex vegetative habitats according to anecdotal field evidence. I chose to address two issues: 1) does vegetation density affect the foraging return of piscivorous juvenile Largemouth Bass? 2) Does vegetation density affect the timing of the ontogeny to piscivory in juvenile Largemouth Bass? To answer objective 1) I conducted foraging trials using piscivorous juvenile Largemouth Bass and Juvenile Fathead Minnows (Pimephales promelas) in eight treatments of varying simulated vegetation densities (0, 125, 250, 500, and 1,000 stems/m2) and complexities (simple and complex). Piscivorous Largemouth Bass consumed the most Fathead Minnows in the 125 stems/m2 simple treatment and the least in the 0 stems/m2 treatment. Indicating that juvenile Largemouth Bass forage least efficiently on Fathead Minnows in habitats with no complexity. To answer objective 2) I conducted enclosure experiments across 5 weeks of the typical time frame (mid-summer) that juvenile Largemouth Bass would transition to piscivory. Thirty-two enclosures were constructed across two 0.10 hectare ponds and treated with four stem densities of simulated vegetation (0, 50, 250, and 500 stems/m2). Three juvenile Largemouth Bass and 30 juvenile Bluegill (Lepomis macrochirus) were added to each enclosure. All fish were sampled twice per week. Largemouth bass growth was measured as total length (mm) and diets were collected via gastric lavage. Bluegill densities were manipulated to stay consistent. It was found that Largemouth Bass switched to piscivory during the second week in the 0, 50, and 500 stems/m2 treatments but did not completely switch in the 250 stems/m2 treatment. Growth mirrored this pattern where Largemouth Bass grew less in the 250 stems/m2 treatment. Differing results in these two experiments suggest that vegetation density does affect the foraging rate and subsequent ontogeny to piscivory in juvenile Largemouth Bass. However, it has an interactive effect with available fish prey species.Natural Resources and Ecology Managemen

A prospective pilot clinical trial evaluating the utility of a dynamic near-infrared imaging device for characterizing suspicious breast lesions

Introduction: Characterizing and differentiating between malignant tumors, benign tumors, and normal breast tissue is increasingly important in the patient presenting with breast problems. Near-infrared diffuse optical imaging and spectroscopy is capable of measuring multiple physiologic parameters of biological tissue systems and may have clinical applications for assessing the development and progression of neoplastic processes, including breast cancer. The currently available application of near-infrared imaging technology for the breast, however, is compromised by low spatial resolution, tissue heterogeneity, and interpatient variation. Materials and methods: We tested a dynamic near-infrared imaging schema for the characterization of suspicious breast lesions identified on diagnostic clinical ultrasound. A portable handheld near-infrared tissue imaging device (P-Scan; ViOptix Inc., Fremont, CA, USA) was utilized. An external mechanical compression force was applied to breast tissue. The tissue oxygen saturation and hemoglobin concentration were recorded simultaneously by the handheld near-infrared imaging device. Twelve categories of dynamic tissue parameters were derived based on real-time measurements of the tissue hemoglobin concentration and the oxygen saturation. Results: Fifty suspicious breast lesions were evaluated in 48 patients. Statistical analyses were carried out on 36 out of 50 datasets that satisfied our inclusion criteria. Suspicious breast lesions identified on diagnostic clinical ultrasound had lower oxygenation and higher hemoglobin concentration than the surrounding normal breast tissue. Furthermore, histopathologic-proven malignant breast tumors had a lower differential hemoglobin contrast (that is, the difference of hemoglobin concentration variability between the suspicious breast lesion and the normal breast parenchyma located remotely elsewhere within the ipsilateral breast) as compared with histopathologic-proven benign breast lesions. Conclusion: The proposed dynamic near-infrared imaging schema has the potential to differentiate benign processes from those of malignant breast tumors. Further development and refinement of the dynamic imaging device and additional subsequent clinical testing are necessary for optimizing the accuracy of detection

The proinsulin C-peptide—a multirole model

The C-peptide links the insulin A and B chains in proinsulin, providing thereby a means to promote their efficient folding and assembly in the endoplasmic reticulum during insulin biosynthesis. It then facilitates the intracellular transport, sorting, and proteolytic processing of proinsulin into biologically active insulin in the maturing secretory granules of the β cells. These manifold functions impose significant constraints on the C-peptide structure that are conserved in evolution. After cleavage of proinsulin, the intact C-peptide is stored with insulin in the soluble phase of the secretory granules and is subsequently released in equimolar amounts with insulin, providing a useful independent indicator of insulin secretion. This brief review highlights many aspects of its roles in biosynthesis, as a prelude to consideration of its possible additional role(s) as a physiologically active peptide after its release with insulin into the circulation in vivo

Towards a Muon Collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work.Comment: 118 pages, 103 figure

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29