Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher.
Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?
Some links on this page may take you to non-federal websites. Their policies may differ from this site.
-
This NSF ITEST project (Award # 2148429) at Illinois State University focuses on engaging students in four Chicago Public High Schools in an afterschool STEM program, SUPERCHARGE, where they experience hands on activities with renewable energy technologies and related sustainability-tied experiences. Between 10 and 20 students met weekly afterschool during the first year of implementation which was preceded by a planning year in which teachers provided feedback on activities and connections to the communities of the schools were developed. Four faculty were involved in the design of the project and activities and an additional group of undergraduate STEM majors were also involved in the design and pilot of all activities. Four goals frame this project and research. These are to learn how (1) high school students’ knowledge of STEM careers and STEM domains change across their participation; (2) the high school students improve their interest in STEM career attainment and their self-efficacy for career relevant skills; (3) the undergraduate STEM majors’ views about Communities of Learners of Underrepresented Discoverers develop across their participation; and (4) teachers’ knowledge of current STEM domains, skills, and careers change. To examine the impact of the programming on each stakeholder group, PEAR’s CIS-S and CIS-E surveys, interviews, activity surveys, and workshop surveys were used. Currently, the data from the first year of programming includes 21 pre-post student surveys and 10 surveys from the undergraduate designers and 9 surveys from the teachers in the program. At this time, statistical tests were not appropriate due to these small numbers, but future years will bolster these numbers, and we anticipate the ability to perform statistical tests as the data set grows. Therefore, we focus on a qualitative analysis of the surveys and interviews at this stage.more » « lessFree, publicly-accessible full text available June 22, 2026
-
The Energy Grid Card Game was designed for pre-college students (grades 6-12) to be played in an informal learning environment. The game explores the technical, environmental, and economic choices and challenges of using energy resources throughout our daily lives. Undergraduates at Illinois State University designed the activity as part of the NSF-funded SUPERCHARGE project, which seeks to improve access to STEM college and career pathways while making connections to engineering and sustainability-related problems that can be addressed in their communities.more » « lessFree, publicly-accessible full text available June 22, 2026
-
The following activities are examples from a unit of study that focuses on harnessing, using, and controlling energy. These activities were designed for pre-college learners in grades 6-12 in informal learning settings as part of the SUPERCHARGE project] by undergraduates at Illinois State University. The goal of the project is to promote interest in college and career pathways related to engineering, sustainability, and renewable energy technologies.more » « lessFree, publicly-accessible full text available June 22, 2026
-
Free, publicly-accessible full text available May 4, 2026
-
Hybrid complexes incorporating synthetic Mn-porphyrins into an artificial four-helix bundle domain of bacterial reaction centers created a system to investigate new electron transfer pathways. The reactions were initiated by illumination of the bacterial reaction centers, whose primary photochemistry involves electron transfer from the bacteriochlorophyll dimer through a series of electron acceptors to the quinone electron acceptors. Porphyrins with diphenyl, dimesityl, or fluorinated substituents were synthesized containing either Mn or Zn. Electrochemical measurements revealed potentials for Mn(III)/Mn(II) transitions that are ~ 0.4 V higher for the fluorinated Mn-porphyrins than the diphenyl and dimesityl Mn-porphyrins. The synthetic porphyrins were introduced into the proteins by binding to a four-helix bundle domain that was genetically fused to the reaction center. Light excitation of the bacteriochlorophyll dimer of the reaction center resulted in new derivative signals, in the 400 to 450 nm region of light-minus-dark spectra, that are consistent with oxidation of the fluorinated Mn(II) porphyrins and reduction of the diphenyl and dimesityl Mn(III) porphyrins. These features recovered in the dark and were not observed in the Zn(II) porphyrins. The amplitudes of the signals were dependent upon the oxidation/reduction midpoint potentials of the bacteriochlorophyll dimer. These results are interpreted as photo-induced charge-separation processes resulting in redox changes of the Mn-porphyrins, demonstrating the utility of the hybrid artificial reaction center system to establish design guidelines for novel electron transfer reactions.more » « less
-
A clear experimental signature of the population of the lowest triplet state of the methane dication is identified in a photoionization experiment. This state is populated only in valence ionization and is absent when the dication is formed by core ionization followed by Auger-Meitner decay. For valence ionization, the total internal energy of the fragment, formed during the deprotonation of , is evaluated. Notably, the distribution of this internal energy peaks at the same value regardless of the initially populated electronic state of . We find that excited electronic states of are predominantly populated with significant rovibrational excitation. Published by the American Physical Society2025more » « lessFree, publicly-accessible full text available April 1, 2026
-
We use one-photon excitation to promote -shell electrons of formic acid (which has a planar equilibrium structure) to an antibonding orbital. The excited molecule is known to have a (chiral) pyramidal equilibrium structure. In our experiment, we determine the handedness of the excited molecule by imaging the momenta of charged fragments, which occur after its Coulomb explosion triggered by Auger-Meitner decay cascades succeeding the excitation. We find that the handedness of the excited molecule depends on its spatial orientation with respect to the propagation (or polarization) direction of the exciting photon. The effect is largely independent of the exact polarization properties of the light driving the excitation. Published by the American Physical Society2024more » « less
-
Context. Planetesimal belts are ubiquitous around nearby stars, and their spatial properties hold crucial information for planetesimal and planet formation models. Aims. We present resolved dust observations of 74 planetary systems as part of the REsolved ALMA and SMA Observations of Nearby Stars (REASONS) survey and archival reanalysis. Methods. We uniformly modelled interferometric visibilities for the entire sample to obtain the basic spatial properties of each belt, and combined these with constraints from multi-wavelength photometry. Results. We report key findings from a first exploration of this legacy dataset: (1) Belt dust masses are depleted over time in a radially dependent way, with dust being depleted faster in smaller belts, as predicted by collisional evolution. (2) Most belts are broad discs rather than narrow rings, with much broader fractional widths than rings in protoplanetary discs. We link broad belts to either unresolved substructure or broad planetesimal discs produced if protoplanetary rings migrate. (3) The vertical aspect ratios (h=H/R) of 24 belts indicate orbital inclinations of ~1–20º, implying relative particle velocities of ~0.1–4 km/s, and no clear evolution of heights with system age. This could be explained by early stirring within the belt by large bodies (with sizes of at least ~140 km to the size of the Moon), by inheritance of inclinations from the protoplanetary disc stage, or by a diversity in evolutionary pathways and gravitational stirring mechanisms. We release the REASONS legacy multidimensional sample of millimetre-resolved belts to the community as a valuable tool for follow-up multi-wavelength observations and population modelling studies.more » « less
An official website of the United States government

Full Text Available