In this study, the anaerobic digestion of mixtures of food waste (FW) and horse manure was investigated using a bench-scale two-phase reactor system. Both phases were maintained at 35°C for the duration of the 30-day study period. The first phase reactors were prepared with biomass mixtures in deionized water such that each mixture had an initial total solids (TS) concentration of 6 wt%. The second phase reactors were inoculated with cow manure in water two weeks prior to the study period at 3 wt% TS. The biogas from all second phase reactors contained greater than 60 vol% methane in the biogas before they were used in the study, thus indicating the presence of active methanogens. Filtrate (5 mL) from the first phase was used as feed to the second phase reactor. The chemical oxygen demand (COD), total organic carbon, and volatile solids (VS) of the feed from Phase 1 increased with FW content in the biomass mixture, and so the organic loading rates (OLRs) to the Phase 2 reactors also increased. Accordingly, the volume of biogas and methane generated from Phase 2 also increased with FW content. The low OLR (<0.2 g VS/L/day), the use of a two-phase system, and the use of filtrate from Phase 1as feed to Phase 2 allowed for high utilization of the feed; the observed specific methane yields (mL/g COD) were greater than 80% of the theoretical yields for all mixtures. The methane yields were statistically similar to within a 95% confidence interval.

The aim of this project is to investigate the photocatalytic activity of ZnO/TiO₂ composite films for the gas-phase oxidation of ethanol. Pure TiO₂, pure ZnO, and their composites were formulated using a sol-gel synthesis method, and the resulting powders were cast and dried as thin films in a flat-plate ultraviolet light-emitting diode (UV LED) reactor. P25 TiO₂ and commercially available ZnO were also used for comparison. The structural, morphological, and optical characteristics of the materials were characterized. The photocatalytic oxidation of ethanol vapors in air after 24 h of reactor operation was used to assess the relative photocatalytic activity of the ZnO/TiO₂ composite films. Our results show that as ZnO content increased in the coupled semiconductor materials, the apparent photocatalytic activity decreased. In this study, pure ZnO (both sol-gel and purchased) had the least photocatalytic activity for vapor-phase ethanol oxidation in our test apparatus. For gas-phase photocatalysis, surface area was shown to be a critical feature for photocatalytic activity. However, the inherent photocatalytic activity of the materials was not decoupled from the effects of surface area in this study.

Graduate Teaching Assistants (GTAs) play a pivotal role in supporting and advancing the educational mission of universities globally. They are fundamental to a university’s instructional workforce and their roles are critical to the undergraduate student experience. This study examines the experiences and perceptions of GTAs (n = 74) at an R2 institution in the Midwest, U.S. Survey results reveal that the majority of surveyed GTAs have been at the institution for at least one year, teach in face-to-face formats with classes typically ranging from 12 to 30, and allocate 11–20 h/week to their instructional duties, although 30% of respondents report >20 h/week. Survey respondents reported a need for more teaching-focused onboarding, discipline-specific training, and more opportunities for feedback on their teaching practices, while almost 50% reported never engaging with discipline-based education research (DBER) literature. Although departmental and institutional training programs were acknowledged, so too was the perception of their lack of accessibility or relevance. Potential strategies for supporting GTAs, particularly early in their careers, include shadowing opportunities, sustained formal classroom management, and pedagogical training that includes an introduction to (and discussion of) the DBER literature, and a reduced teaching load in the first semester. Universities should prioritize and design GTA professional development using a cognitive apprenticeship framework. This would invest in the undergraduate student experience and directly support an institution’s educational mission. It is also highly effective in preparing highly skilled graduates to enter an increasingly connected global workforce and could positively contribute to an engaged alumni base.

A novel application of photocatalysis was investigated to reduce diurnal evaporative fuel vapor emissions from automobiles. A light-weight annulus photocatalytic device was designed, fabricated, and characterized for its performance for the oxidation of diurnal evaporative fuel vapor emissions. The prototype photocatalytic device was made with PVC pipe and ultraviolet (λ = 365 nm) light emitting diodes (UV LEDs) as light sources. Commercially available Evonik P25 TiO₂ was used as the photocatalyst. The study results demonstrate that the UV LED photocatalytic device is capable of reducing diurnal evaporative fuel vapor emissions from automobiles by 60 wt%. However, the presence of high concentrations of light alkanes and aromatic fuel vapors in the diurnal emissions may limit the longevity of the device due to photocatalyst deactivation. Further development of the idea to enhance the longevity of its performance is recommended.