Assessing Undergraduate Sustainability Knowledge at California Polytechnic State University

Sustainability education has become an important focus of many higher education institutions (HEIs), with the inclusion of many sustainability-related learning objectives for undergraduate students. As sustainability is a new, rising discipline, an increasing number of HEIs have made efforts to assess their teaching and learning effectiveness. However, most assessments fall short in determining the relationship between sustainability curriculum and the impacts on leaning outcomes. Therefore, this study aims to assess the impact of academic setting, specifically of a structured sustainability curriculum, on undergraduate sustainability knowledge, as well as analyze the implications of perceived barriers and opportunities to implementing sustainability into academics. Using California Polytechnic State University, San Luis Obispo (Cal Poly) as a case study, this research emphasizes the results from an online sustainability knowledge survey administered to honors students who take a structured sustainability knowledge curriculum and general students who are not required to take any sustainability courses, but can elect to do so. The study reveals that honors students have significantly higher sustainability knowledge scores (SKS) after taking a structured sustainability curriculum, but also reveals that those post-curriculum SKS of honors students are not significantly different from that of general students after taking 3 courses. The results further indicate that honors students that take a 3-course sustainability curriculum do not score significantly higher than those that take a 1-course sustainability curriculum. However, general students that take 3 sustainability-related courses score significantly higher than general students who take 0, or 1 to 2 sustainability-related courses. These results suggest that unlike honors students, general students need to take a minimum of 3 courses in sustainability to achieve significantly higher SKS. The findings also show that the SKS of students do not significantly differ across colleges and that the SKS of students in the general population have the potential to improve, suggesting that additional sustainability education can benefit all students. Additionally, the analysis of student perceptions reveals that students support the integration of sustainability into existing courses, which can help address the main perceived barriers of time constraints, lack of course promotion, and lack of relevance to major. Ultimately, the results suggest that university-level decision-makers should focus efforts on integrating sustainability into existing courses, increasing the opportunity for all students to take at least 3 sustainability-related courses during their undergraduate experience. Such efforts would be a first step in developing sustainability education at an HEI and would help achieve significant improvement in undergraduate student SKS

An overview of temperature issues in microwave-assisted pyrolysis

Microwave-assisted pyrolysis is a promising thermochemical technique to convert waste polymers and biomass into raw chemicals and fuels. However, this process involves several issues related to the interactions between materials and microwaves. Consequently, the control of temperature during microwave-assisted pyrolysis is a hard task both for measurement and uniformity during the overall pyrolytic run. In this review, we introduce some of the main theoretical aspects of the microwaves–materials interactions alongside the issues related to microwave pyrolytic processability of materials

Characterization of the Pesticide Properties of Tobacco Bio-oil

Pyrolysis converts biomass such as agricultural and forestry waste into bio-oil. Our interest in the chemical analysis of bio-oil began with tobacco, which is rich in nicotine (a known pesticide). Initial inhibition assays performed with the bio-oil on the Colorado potato beetle, a pest currently resistant to all major insecticides, showed high pesticide activity as expected. Surprisingly, the nicotine-free phases of the bio-oil were also found to be highly lethal to the beetles. Thus, it was hypothesized that some of the alkaloids in plants were preserved during pyrolysis, and gave rise to the activity. Pesticide characteristics of tobacco and coffee bio-oils have been recorded on a number of insects as well as a variety of bacteria and fungi that do not currently respond well to chemical treatment; e.g., Streptomyces Scabies (a common potato scab disease). The current focus is to isolate and identify the components responsible for the pest inhibition, and in turn fully characterize their properties as a novel source of natural pesticides. The procedure begins with a crude separation or fractionation by distillation or extraction to simplify the chemical composition. The fractions are then screened by the activity assay. Analytical separation and mass spectral detection (GC-MS and LC-MS) are then used to generate chemical fingerprints for comparative analysis against libraries of known compounds to identify the active component(s). A mixture of chemical standards is generated from these identified, potentially active, components. This mixture is tested by the activity assay, and chemicals are sequentially removed from this mixture to identify the active components and potential synergistic effects between these components. Thus, a potential pesticide originating from agriculturally-based bio-oil is identified

Bio-efficacy of hydroxy-selenomethionine as a selenium supplement in pregnant dairy heifers and on the selenium status of their calves

This study aimed to determine the effects of supplementing pregnant heifers with the organic selenium source 2-hydroxy-4-methylselenobutanoic acid (HMSeBA) during last eight weeks of pregnancy on dam and calf Se status. A total of 42 in-calf heifers were recruited to the study and randomly allocated to one of three treatments; a negative control (Con), sodium selenite (NaSe) or HMSeBA. Animals were blocked by body weight, body condition score, and expected calving date prior to treatment allocation. Following enrollment all animals underwent a seven week wash-out period after which they received their respective supplements, topped dressed daily onto a basal diet for the last eight weeks of pregnancy. Heifer blood samples were taken at weekly intervals from enrollment until two weeks before expected calving date, and as soon as possible after calving for determination of whole blood glutathione peroxidase activity (GSH-Px) and plasma selenium (Se) and malondealdehyde (MDA) concentrations. Selenized amino acids were determined in plasma samples taken at three weeks pre-calving. A colostrum sample was taken as close to parturition as possible for determination of colostrum total Se, selenized amino acid, and Immunoglobulin G (IgG) concentration. Calves were blood sampled as close to birth as possible for determination of whole blood GSH-Px activity and plasma Se and MDA concentration. Differences in whole blood GSH-Px activity did not become apparent until calving; GSH-Px activity was lowest in Con heifers (P < 0.05) but similar between NaSe and HMSeBA. Plasma Se was lowest in unsupplemented heifers and greatest in those supplemented with HMSeBA (P < 0.001) and this was attributable to greater selenomethionine concentrations in the plasma of HMSeBA heifers (P < 0.01). Colostrum Se was lowest in Con heifers and greatest in HMSeBA (P < 0.001), the greater Se concentration of HMSeBA heifers was attributable to a greater proportion of total Se comprising selenocysteine (P = 0.061), the reason for this is not known. There was no effect of supplementation on colostrum IgG concentration. Plasma Se was lowest in those calves born to Con heifers and greatest in those born to HMSeBA heifers (P < 0.001). There were no effects of treatment on calf whole blood GSH-Px activity or plasma MDA concentration. The enhanced Se status associated with HMSeBA supplementation is likely a consequence of selenomethionine supply and may confer benefits to both the dam and her calf post-partum

Bioenergy II: Characterization of the Pesticide Properties of Tobacco Bio-Oil

Pyrolysis converts biomass such as agricultural and forestry waste into bio-oil, preserving some chemicals while creating other, new ones. Nicotine, a chemical present in tobacco leaves and a known pesticide, was found to remain intact during pyrolysis. As expected, insecticidal properties were observed for tobacco bio-oil. Pesticide characteristics of tobacco bio-oil have been observed on the Colorado potato beetle (CPB), a pest currently resistant to all major insecticides, as well as a few bacteria and fungi that do not currently respond well to chemical treatment. Unexpectedly, nicotine-free fractions of the bio-oil were also found to be highly lethal to the beetles and successful at inhibiting the growth of select microorganisms. Through GC-MS, it was found that the active, nicotine-free fractions were rich in phenolics, chemicals likely created from lignin during pyrolysis. While bio-oils in general are known to contain phenolic chemicals, such as cresols, to our best knowledge, quantitative analysis has not been performed to determine if these chemicals are solely responsible for the observed pesticide activities. Based on GC-MS results, ten of the most abundant chemicals, eight of which were phenolic chemicals, were identified and examined through bio-assays. A mixture of these chemicals at the concentration levels found in the bio-oil did not account for the bio-oil activity towards the microorganisms. Tobacco bio-oil may have potential as a pesticide, however, further analyses using liquid chromatography is necessary to identify the remaining active chemicals

Powder Compaction: Compression Properties of Cellulose Ethers

Effective development of matrix tablets requires a comprehensive understanding of different raw material attributes and their impact on process parameters. Cellulose ethers (CE) are the most commonly used pharmaceutical excipients in the fabrication of hydrophilic matrices. The innate good compression and binding properties of CE enable matrices to be prepared using economical direct compression (DC) techniques. However, DC is sensitive to raw material attributes, thus, impacting the compaction process. This article critically reviews prior knowledge on the mechanism of powder compaction and the compression properties of cellulose ethers, giving timely insight into new developments in this field

Autothermal reforming of palm empty fruit bunch bio-oil: thermodynamic modelling

This work focuses on thermodynamic analysis of the autothermal reforming of palm empty fruit bunch (PEFB) bio-oil for the production of hydrogen and syngas. PEFB bio-oil composition was simulated using bio-oil surrogates generated from a mixture of acetic acid, phenol, levoglucosan, palmitic acid and furfural. A sensitivity analysis revealed that the hydrogen and syngas yields were not sensitive to actual bio-oil composition, but were determined by a good match of molar elemental composition between real bio-oil and surrogate mixture. The maximum hydrogen yield obtained under constant reaction enthalpy and pressure was about 12 wt% at S/C = 1 and increased to about 18 wt% at S/C = 4; both yields occurring at equivalence ratio Φ of 0.31. The possibility of generating syngas with varying H2 and CO content using autothermal reforming was analysed and application of this process to fuel cells and Fischer-Tropsch synthesis is discussed. Using a novel simple modelling methodology, reaction mechanisms were proposed which were able to account for equilibrium product distribution. It was evident that different combinations of reactions could be used to obtain the same equilibrium product concentrations. One proposed reaction mechanism, referred to as the ‘partial oxidation based mechanism’ involved the partial oxidation reaction of the bio-oil to produce hydrogen, with the extent of steam reforming and water gas shift reactions varying depending on the amount of oxygen used. Another proposed mechanism, referred to as the ‘complete oxidation based mechanism’ was represented by thermal decomposition of about 30% of bio-oil and hydrogen production obtained by decomposition, steam reforming, water gas shift and carbon gasification reactions. The importance of these mechanisms in assisting in the eventual choice of catalyst to be used in a real ATR of PEFB bio-oil process was discussed