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A comprehensive external evaluation of the First2 Network. 

Organic carbon (OC) is a highly diverse class of compounds that represents a small but critical fraction of the atmosphere’s chemical composition. Volatile organic compounds (VOCs), when combined with nitrogen oxides (NOx), can produce tropospheric ozone (O3), a regulated air pollutant. OC also represents a large and growing fraction of aerosol mass, either through direct emissions from sources like fossil combustion and biomass burning, or through secondary chemistry by the oxidation and subsequent reduction of vapor pressure of VOCs leading to condensational growth. Clouds droplets and precipitation can contain additional OC due to the dissolution of soluble organic gases to the aqueous phase. OC has abundantly been found in aqueous samples of clouds, fog, and precipitation, exposing these compounds to unique aqueous chemical reactions and wet deposition. However, the concentrations and controlling factors of atmospheric aqueous organic carbon remain highly unconstrained. Cloud water measurements at Whiteface Mountain in the Adirondack Mountains in upstate New York have revealed an increasing trend of Total Organic Carbon (TOC), with annual median concentrations doubling in 14 years, possibly signaling a growing trend in atmospheric OC. However, the causes and potential consequences of this trend remain unclear. Another question that has yet to be explored is if this trend in OC extends beyond WFM. To answer this question, this work explores the trends of WFM cloud water and 4 additional long-term cloud water and wet deposition datasets that have measured TOC or dissolved OC (DOC) throughout the Northeast US. These sites include Mt Washington, NH, Hubbard Brook NH, Thompson Farm NH, and Sleepers River Vermont. This work will also discuss potential hypotheses driving this increasing trend including increased biomass burning influence and increased biogenic emissions in the region. 

Abstract There is a critical need to generate environmentally relevant microplastics (MPs) and nanoplastics (NPs) to better investigate their behavior in laboratory settings. Environmental MPs are heterogenous in size and shape, unlike monodisperse and uniform microspheres commonly used as surrogates. Cryogenic grinding, or cryomilling, was successfully utilized to transform polystyrene (PS) bulk material into heterogenous micro and nano fragments. Fourier-Transform Infrared (FTIR) spectroscopy confirmed that this approach did not alter polymer surface chemistry. The number of milling cycles (time of milling) and frequency of grinding (intensity of milling) were varied to investigate the role cryomilling parameters had on generated MP characteristics. The resulting particle size distributions of cryomilled samples were measured and compared. Coulter Counter and Nanoparticle Tracking Analysis (NTA) were used to measure the particle size distributions at the micro and nanoparticle size ranges, respectively. Microspheres were used to determine what camera settings yielded more accurate sizing and to reduce bias in the NTA analysis. Increasing milling cycles generally increased the number of smaller particles. The evolution of the measured size distributions indicated that small nanosized fragments broke off from larger MPs during cryomilling, steadily eroding larger MP fragments. The number of milling cycles was observed to more consistently impact the size distributions of fragments compared to the frequency of milling. This study offers both analysis of the cryomilling process and recommendations for generating more realistic PS MP/NPs for examining environmental fate and effects. 

The Urban STEM Collaboratory is a five-year project sponsored by the National Science Foundation (NSF) that addresses challenges to student success in STEM disciplines through a multi-institutional collaboration via the University of Memphis (UofM), University of Colorado Denver (CU Denver), and Indiana University--Purdue University Indianapolis (IUPUI). Study groups, tutoring, peer and faculty mentoring, and career exploration programs are being used across the three campuses to increase the participants’ commitment to a STEM field. Innovative features from Course Networking (CN) software are being deployed to provide scholars with evidence of their learning journey while expanding a meaningful academic cloud-based social network. This paper extends a previous introductory ASEE conference paper titled: “Launching the Urban STEM Collaboratory,” (Goodman et al., 2020), which outlined the initial efforts of the tri-campus collaboration. The purpose of the present paper is to summarize the impact of the project, including data analysis of effectiveness, for Year 1: 2019-2020 and Year 2: 2020-2021. Although still in progress, with the longitudinal efficacy of several of the project’s components undetermined, the project’s organizational structure, activities, and findings to date should be of value to others conducting or proposing projects with similar goals. 

The Urban STEM Collaboratory is a five-year project sponsored by the National Science Foundation (NSF) that addresses challenges to student success in STEM disciplines through a multi-institutional collaboration via the University of Memphis (UofM), University of Colorado Denver (CU Denver), and Indiana University--Purdue University Indianapolis (IUPUI). Study groups, tutoring, peer and faculty mentoring, and career exploration programs are being used across the three campuses to increase the participants’ commitment to a STEM field. Innovative features from Course Networking (CN) software are being deployed to provide scholars with evidence of their learning journey while expanding a meaningful academic cloud-based social network. This paper extends a previous introductory ASEE conference paper titled: “Launching the Urban STEM Collaboratory,” (Goodman et al., 2020), which outlined the initial efforts of the tri-campus collaboration. The purpose of the present paper is to summarize the impact of the project, including data analysis of effectiveness, for Year 1: 2019-2020 and Year 2: 2020-2021. Although still in progress, with the longitudinal efficacy of several of the project’s components undetermined, the project’s organizational structure, activities, and findings to date should be of value to others conducting or proposing projects with similar goals. 

For short-wavelength infrared (SWIR) avalanche photodiodes, a separate absorption, charge, and multiplication design is widely used. AlInAsSb on an InP substrate is a potential multiplication layer with a lattice match to absorber candidates across the SWIR. Our new measurements demonstrate that AlInAsSb on InP is a promising multiplier candidate with a relatively low dark current density of 10−4 A/cm2 at a gain of 30; a high gain, measured up to 245 in this study; and a large differentiation of electron and hole ionization leading to a low excess noise, measured to be 2.5 at a gain of 30. These characteristics are all improvements over commercially available SWIR detectors incorporating InAlAs or InP as the multiplier. We measured and analyzed gain for multiple wavelengths to extract the ionization coefficients as a function of an electric field over the range 0.33–0.6 MV/cm. 

This Complete Evidence-based Practice paper will describe how three different public urban research universities designed, executed, and iterated Summer Bridge programming for a subset of incoming first-year engineering students over the course of three consecutive years. There were commonalities between each institution’s Summer Bridge, as well as unique aspects catering to the specific needs and structures of each institution. Both these commonalities and unique aspects will be discussed, in addition to the processes of iteration and improvement, target student populations, and reported student outcomes. Finally, recommendations for other institutions seeking to launch or refine similar programming will be shared. Summer Bridge programming at each of the three institutions shared certain communalities. Mostly notably, each of the three institutions developed its Summer Bridge as an additional way to provide support for students receiving an NSF S-STEM scholarship. The purpose of each Summer Bridge was to build community among these students, prepare them for the academic rigor of first-year engineering curriculum, and edify their STEM identity and sense of belonging. Each Summer Bridge was a 3-5 day experience held in the week immediately prior to the start of the Fall semester. In addition to these communalities, each Summer Bridge also had its own unique features. At the first institution, Summer Bridge is focused on increasing college readiness through the transition from summer break into impending coursework. This institution’s Summer Bridge includes STEM special-interest presentations (such as biomedical or electrical engineering) and other development activities (such as communication and growth mindset workshops). Additionally, this institution’s Summer Bridge continues into the fall semester via a 1-credit hour First Year Seminar class, which builds and reinforces student networking and community beyond the summer experience. At the second institution, all students receiving the NSF S-STEM scholarship (not only those who are first-year students) participate in Summer Bridge. This means that S-STEM scholars at this institution participate in Summer Bridge multiple years in a row. Relatedly, after the first year, Summer Bridge transitioned to a student-led and student-delivered program, affording sophomore and junior students leadership opportunities, which not only serve as marketable experience after graduation, but also further builds their sense of STEM identity and belonging. At the third institution, a special focus was given to building community. This was achieved through several means. First, each day of Summer Bridge included a unique team-oriented design challenge where students got to work together and know each other within an engineering context, also reinforcing their STEM identities. Second, students at this institution’s Summer Bridge met their future instructors in an informal, conversational, lunch setting; many students reported this was one of their favorite aspects of Summer Bridge. Finally, Summer Bridge facilitated a first connect between incoming first-year students and their peer mentors (sophomore and junior students also receiving the NSF S-STEM scholarship), with whom they would meet regularly throughout the following fall and spring semesters. Each of the three institutions employed processes of iteration and improvement for their Summer Bridge programming over the course of two or three consecutive years. Through each version and iteration of Summer Bridge, positive student outcomes are demonstrated, including direct student feedback indicating built community among students and the perception that their time spent during Summer Bridge was valuable. Based on the experiences of these three institutions, as well as research on other institutions’ Summer Bridge programming, recommendations for those seeking to launch or refine similar Summer Bridge programming will also be shared.