Electronic structure of a subnanometer wide bottom-up fabricated graphene nanoribbon: End states, band gap and dispersion

Angle-resolved two-photon photoemission and high-resolution electron energy loss spectroscopy are employed to derive the electronic structure of a sub-nanometer tomically precise quasi-one-dimensional graphene nanoribbon (GNR) on Au(111). We resolved occupied and unoccupied electronic bands including their dispersion and determined the and gap, which possesses an unexpected large value of 5.1 eV. Supported by density functional theory (DFT) calculations for the idealized infinite polymer and finite size oligomers an unoccupied non-dispersive electronic state with an energetic position in the middle of the band gap of the GNR could be identified. This state resides at both ends of the ribbon (end state) and is only found in the finite sized systems, i.e. the oligomers.Comment: 5 pages, 4 figure

Electronic structure changes during the surface-assisted formation of a graphene nanoribbon

High conductivity and a tunability of the band gap make quasi-one-dimensional graphene nanoribbons (GNRs) highly interesting materials for the use in field effect transistors. Especially bottom-up fabricated GNRs possess well-defined edges which is important for the electronic structure and accordingly the band gap. In this study we investigate the formation of a sub-nanometer wide armchair GNR generated on a Au(111) surface. The on-surface synthesis is thermally activated and involves an intermediate non-aromatic polymer in which the molecular precursor forms polyanthrylene chains. Employing angle-resolved two-photon photoemission in combination with density functional theory calculations we find that the polymer exhibits two dispersing states which we attribute to the valence and the conduction band, respectively. While the band gap of the non-aromatic polymer obtained in this way is relatively large, namely 5.25 ± 0.06 eV, the gap of the corresponding aromatic GNR is strongly reduced which we attribute to the different degree of electron delocalization in the two systems

End states, band gap, and dispersion

Angle-resolved two-photon photoemission and high-resolution electron energy loss spectroscopy are employed to derive the electronic structure of a subnanometer atomically precise quasi-one-dimensional graphene nanoribbon (GNR) on Au(111). We resolved occupied and unoccupied electronic bands including their dispersion and determined the band gap, which possesses an unexpectedly large value of 5.1 eV. Supported by density functional theory calculations for the idealized infinite polymer and finite size oligomers, an unoccupied nondispersive electronic state with an energetic position in the middle of the band gap of the GNR could be identified. This state resides at both ends of the ribbon (end state) and is only found in the finite sized systems, i.e., the oligomers

Teaching Time: Postoperative Urinary Catheter Care in the Preoperative Setting Before Surgery

Abstract Problem: Patients who have same day surgery often have little or no recall of the postoperative home care instructions when delivered in the aftercare area. The number of instructions that are required for home care, combined with medications given for pain and nausea as well as anesthesia, can make recall of these instructions difficult. The purpose of this quality improvement project was to provide the postoperative instructions for post prostatectomy patients discharged with an indwelling urinary catheter in the pre-operative area before the patient underwent surgery to decrease the length of time the patient spent in the recovery unit. Context: At an Ambulatory Surgery Center on the campus of a medical center in Northern California, the current performance reflected an average stay in the PACU of 150 minutes. After assessing the current performance and reviewing regional data that reflected a high of 251 minutes and a low of 85 minutes, it was determined that there was an opportunity for improvement to 120 minutes for this unit’s performance. Interventions: Handouts on catheter care were provided in a discharge folder, a video to watch while waiting for their surgery to start and hands on practice with a night bag and leg bag were the interventions for this project. Measures: The primary outcome was to reduce the length of stay in the recovery unit from 150 minutes to 120 minutes during a three-month trial period from April 2022 to June 2022 and 100% of patients receiving the education in the preoperative area. Results: Despite two outlier surgical patients, the goal of the project was met, with a reduction in the average length of stay in the Post Anesthesia Care Unit to 116 minutes and all of the patients included in the trial period received their education in the preoperative area. Conclusion: Providing the discharge teaching in the preoperative area can be successfully implemented resulting in a reduction in the length of stay for patients discharged with an indwelling urinary catheter. Key Words: indwelling urinary catheter, preoperative teaching, postoperative education, PACU length of sta

How expository text structure instruction effects reading comprehension

The purpose of this study was to determine the effect of compare/contrast and cause/effect text structure instruction on fifth grade readers’ comprehension of expository text. Three fifth grade students participated in this eight-week study. During the study, the participants met with the researcher thirty minutes a day, five times a week for eight weeks. The focus of the intervention was the compare and contrast and cause and effect text structures. The students learned about the specific text structures by reading leveled passages, identifying target words, and completing a graphic organizer. The results suggested that the participants’ demonstrated growth in expository reading comprehension and knowledge of compare and contrast and cause and effect text structures, but not statistically significantly

NEPA, SEPA, and the Evergreen-House Gas State: How Washington\u27s State Environmental Policy Act and the Absence of Greenhouse Gas Calculation Guidance Negatively Impacts Future Project Proposals

The National Environmental Policy Act (NEPA) requires all federal agencies to consider the environmental effects of a proposed action that may significantly affect the environment. In addition to outlining the important pieces of NEPA, this article explores the State Environmental Policy Act (SEPA), Washington’s state-equivalent to NEPA. Established in 1971 and modeled after NEPA, SEPA requires that an Environmental Impact Statement (EIS) be prepared for any governmental project proposal that significantly affects the environment. Currently under both state and federal law, there is no rule or guidance that instructs project applicants on how to calculate greenhouse gas emissions in a manner that satisfies statutory requirements. The Washington Department of Ecology rescinded its only guidance in 2016 with regard to adequate greenhouse gas calculation to be included in an EIS. As a result, project applicants must make an educated guess and rely on previous case law and administrative decisions when measuring greenhouse gas emissions for their EIS. The lack of a clear, uniform rule under SEPA will continue to foster confusion about how to calculate the direct and indirect effects of greenhouse gas emissions for an EIS. This article argues that Washington’s Department of Ecology—or any other lead agency— should establish a rule on how to quantify, analyze, and mitigate greenhouse gas emissions under SEPA

Nonlinear optical response of photochromic azobenzene-functionalized self- assembled monolayers

The combination of photochromic and nonlinear optical (NLO) properties of azobenzene-functionalized self-assembled monolayers (SAMs) constitutes an intriguing step towards novel photonic and optoelectronic devices. By utilizing the second-order NLO process of second harmonic generation (SHG), supported by density-functional theory and correlated wave function method calculations, we demonstrate that the photochromic interface provides the necessary prerequisites en route towards possible future technical applications: we find a high NLO contrast on the order of 16% between the switching states. These are furthermore accessible reversibly and with high efficiencies in terms of cross sections on the order of 10−18 cm2 for both photoisomerization reactions, i.e., drivable by means of low-power LED light sources. Finally, both photostationary states (PSSs) are thermally stable at ambient conditions

Alicia Utecht Honors Portfolio

Alicia Utecht\u27s honors portfolio captured in May 2019

Reduction of methemerythrin in the erythrocytes of Phascolopsis gouldii

The non-heme oxygen carrier hemerythrin (Hr) undergoes autooxidation to give metHr, Fe(III),Fe(III) , a form that will not function in oxygen storage or transport. A methemerythrin reduction system has been isolated from the erythrocytes of the sipunculid Phascolopsis gouldii that reduces metHr to deoxyHr, Fe(II),Fe(II) , the active form in oxygen transport and storage. This methemerythrin reduction system is composed of cytochrome b(,5) and cytochrome b(,5) reductase with NADH acting as the source of electrons;EPR has shown the involvement of a one-electron reduction pathway for metHr in intact erythrocytes. Erythrocytes that have been subjected to stress from lack of oxygen show a (semi-met)(,R)Hr-type signal that progressively grows with time, presumably generated from reduction of metHr;A soluble cytochrome b(,5) was isolated from the erythrocytes of P. gouldii and characterized. The P. gouldii cytochrome b(,5) is very similar to cytochrome b(,5) found in the hemoglobin-containing erythrocytes;A cytochrome b(,5) reductase was also isolated from the erythrocytes of P. gouldii. This enzyme is membrane-bound and was solubilized with 2% Triton X-100, a non-ionic detergent. This enzyme catalyzes the reduction of cytochrome b(,5) by NADH. Use of this enzyme to keep the cytochrome b(,5) reduced completes a metHr reduction system with NADH as the electron donor. The metHr is first reduced to (semi-met)(,R)Hr by the reduced cytochrome b(,5). The (semi-met)(,R)Hr reacts further to give deoxyHr in a manner analogous to the reduction of metHr with inorganic reagents;Cytochrome b(,5) was also isolated from the erythrocytes of Themiste zostericola, showing that cytochrome b(,5) is a common component of hemerythrin-containing erythrocytes;Reduced glutathione has also been detected in P. gouldii erythrocytes. Reduced glutathione is capable of reducing metHr, albeit more slowly than the cytochrome b(,5) metHr reduction system