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Economic and environmental evaluation of the role for waste CO2 from ethanol fermentation to decarbonize transportation in the US
No full textTransitioning to alternative energy carriers is one of the primary options for reducing greenhouse gas emissions attributable to transportation. In the US, ethanol from corn grain covers 10.5% of gasoline demand from road transport today. Its production could be scaled-up further to also make sustainable aviation fuel. Additionally, the biogenic CO2 produced during fermentation could provide an option for carbon removal or for additional fuel production. In this study, we investigate the economic and environmental impacts of using the CO2 from ethanol fermentation either through capturing and sequestering the CO2 (CCS) or through the production of electrofuels (CCU), via fischer-tropsch and methanol-to-jet as conversion technologies. We find that CCS can increase the total offset CO2 by 135% compared to ethanol-to-jet plants while increasing the minimum selling price (MSP) of the produced biofuel by 5-7%. Comparatively, there is significant variation in the results for CCU pathways, increasing the total offset CO2 by 90 - 205%; however, the MSP of the electrofuels produced is 36 – 218% higher than the biofuels produced. This study highlights the trade-offs between fuel carbon intensity, costs, production volumes and output fuel mix for renewable fuel facilities, with the optimal configuration being dependent on the project's primary objectives.•Evaluates the use CO2 from ethanol fermentation for sequestration or fuel production.•Economic and environmental comparison of fischer-tropsch and methanol to jet pathways.•CCS increases total offset CO2 by 135%, while increasing fuel cost by 5 -7%.•CCU increases total offset CO2 by 90-205%, while increasing fuel cost by 36 -218%.•Highlights trade-offs between carbon intensity, cost, production volume and fuel mix.Limited research exists on the most effective use of carbon in ethanol plants to decarbonize transportation. This study reports that incorporation of sequestration or electrofuel production can improve economic efficiency of emissions reduction
Assessing Complexity as an Indicator of Frailty in Older Adult Smart Home Residents
Full text linkBackground: In the context of older adults’ health, the idea of complexity consists of two seemingly opposite phenomena. On one hand, health needs become more complex with age and on the other, the body’s systems and processes tend toward less complexity. The theory of complexity and aging suggests that (1) measuring the complexity of the body’s physiological and behavioral signals can illuminate a person’s adaptive capacity, and (2) one’s decreasing complexity is indicative of decreased adaptability and increasing frailty. I hypothesize that if a person’s underlying complexity, and therefore adaptive capacity, could be estimated using continuous unobtrusive environmental sensor-based monitoring it would open opportunities for early identification of incipient frailty, underpinning interventions aimed at maintaining older adults’ ability to age-in-place safely. This dissertation consists of three manuscripts exploring how complexity may be used as a key indicator of older adult health within the context of a long-term sensor-based remote monitoring system. Method: Manuscript 1 is a Principle-Based Concept Analysis of the use of complexity as a concept in gerontological nursing literature. Manuscript 2 reports results of simulations mimicking smart home sensor data to validate measurements of complexity taken from complexity science. Manuscript 3 is an exploratory multiple method case series study using real-world historic sensor-based data and nursing assessment data gathered from community-dwelling smart home residents age 65+ to measure the complexity of their daily activities, describe complexity changes over time, and relate these changes to frailty. Implications for Nursing: This dissertation expands and clarifies the conceptualization of complexity in relation to frailty within a nursing-centered lens. Study findings (1) resulted in tools nurses can use for measuring and interpreting the complexity of sensor data; (2) add clarity on the conceptualization of complexity in gerontological nursing; and, (3) generate important questions for future nurse-driven smart home research
Wood preservation and wood products treatment training manual
Full text linkMany standards and specifications exist to control the quality of treated wood and protect the purchaser. Since November 1986, federal regulations administered by the Environmental Protection Agency (EPA) have restricted the sale and use of certain preservatives to ensure that only properly trained applicators, or people under their direct supervision, have access to them. Wood pesticides (preservatives) extend the life of wood products by protecting them from damage by insects, fungi, marine borers, and weather. Preservatives are applied depending on how and where the wood products will be used, the expected conditions of exposure to wood-destroying agents, and the cost per year of service life. Crossties, poles, posts, and other wood products that contact the ground or are exposed to the weather must be protected with preservatives to ensure a reasonable service life. Other wood products not in contact with the ground may be treated as a precautionary measure even though they are not exposed to moisture and weather. Long-term tests and experience show the levels of protection needed for various wood products and uses. Federal and state specifications, the requirements of the American Wood Preservers Association, and building codes are the most relevant regulations
THE IMPACT OF PHOSPHOMIMICS ON THE ALLOSTERIC REGULATION OF PHOSPHOENOLPYRUVATE CARBOCYATION (PEPC) FROM SETARIA VIRIDIS
Full text linkThe carbon concentrating mechanism of C4 photosynthesis has been extensively studied, revealing a complex suite of anatomical and biochemical adaptations required for its high photosynthetic efficiency. While there is growing interest in optimizing this pathway to enhance crop resilience under abiotic stress, many questions remain regarding the regulation and evolution of its primary rate-limiting enzymes, particularly phosphoenolpyruvate carboxylase (PEPC). To support bioengineering efforts aimed at improving carbon assimilation, it is essential to better understand how specific factors influence PEPC kinetics and regulation. This thesis investigates how PEPC kinetic properties and allosteric regulation is fine-tuned through post-translational modifications in the C4 model species Setaria viridis. Focusing on phosphorylation at the conserved N-terminal Ser-11 residue, I explore how phosphomimic substitutions (SvPEPC_S11D and SvPEPC_S11E) at this serine residue impact PEPC kinetic parameters, including substrate affinity (Kₚₑₚ) and sensitivity to key allosteric regulators such as malate and glucose 6-phosphate (G6-P). These findings demonstrate that phosphorylation at Ser-11 plays a key role in modulating the trade-off between PEPC activity and feedback inhibition in C4 photosynthesis. Phosphomimic variants at Ser-11 were generated by substituting this residue with the negatively charged aspartic acid (SvPEPC_S11D) or glutamic acid (SvPEPC_S11E). These PEPC variants had significantly different affinity for PEP (higher KPEP) compared to the wild-type enzyme (SvPEPC_WT), indicating the phosphomimics altered the PEP binding affinity. Additionally, both phosphomimics showed a higher AC50 for G6-P, suggesting enhanced sensitivity to this allosteric activator, while exhibiting elevated IC50 values for malate, indicating reduced susceptibility to feedback inhibition. Caution should be taken when interpreting the AC50 and IC50 data as much higher concentrations of the SvPEPC_WT enzyme were used in these assays compared to SvPEPC_S11D and SvPEPC_S11E enzymes. Together, these shifts in kinetic and allosteric parameters suggest that the phosphomimics do modify PEPC similarly to phosphorylation at Ser-11. However, there were differences between the response of SvPEPC_S11D and SvPEPC_S11E variants to G6-P and malate. The allosteric regulation of the SvPEPC_WT variant from the E. coli expression system also differed from the WT PEPC extracted from leaf tissue. This work provides direct evidence that the phosphomimic in the E. coli expression system have some but limited use in understanding the role of phosphorylation at Ser-11. Additionally, this work demonstrates that PEPC extracted from leaf tissue differs significantly from the enzyme generated in E. coli suggesting the potential importance of other post-translational modifications in PEPC responses to allosteric regulation
THERMAL EFFECTS ON THE MECHANICAL PROPERTIES OF AS-MANUFACTURED ZIRCALOY-2 AND ZIRCALOY-4 FUEL CLADDING
Full text linkZircaloy-2 and Zircaloy-4 were widely used as cladding materials in commercial light water reactors due to their corrosion resistance, low neutron absorption, and mechanical durability. After reactor discharge, the cladding of the spent nuclear fuel can experience elevated temperatures for extended periods during dry storage, potentially altering its mechanical properties. While prior research often focuses on irradiation damage, less attention has been given to isolating the thermal response of unirradiated, as-manufactured cladding. This study examines how heat treatments ranging from 300°C to 570°C and lasting 6.8 to 2064 hours affect the mechanical behavior of unirradiated Zircaloy-2 and Zircaloy-4. Vickers microhardness testing at room temperature was used to assess changes in hardness, while axial tensile testing at both room temperature and 200°C, supported by a digital image correlation extensometer, was used to evaluate mechanical performance. Scanning electron microscopy micrographs were also collected on select samples to qualitatively examine changes in microstructure across heat treatment conditions. Heat treatment generally led to reductions in yield strength, ultimate tensile strength, and hardness compared to as-manufactured baselines, with more significant degradation at higher temperatures and longer durations. Hardness trends were compared with tensile data to assess whether microhardness can serve as a proxy for overall mechanical performance. These findings establish a baseline for strength evolution in thermally treated, unirradiated zirconium cladding and may inform future material assessments and modeling efforts related to dry storage
CloverGram, August 2025
No full textIn this issue: Airport Greeters Still Needed for Campers; 4-H Awards Ceremony; Webinar: Frame by Frame
Padilla, Merkley, Wyden, Bonamici Lead Bipartisan Group Demanding Administration Release Over $50 Million for Agricultural Farm Worker Students
Full text linkWASHINGTON, D.C. — U.S. Senators Alex Padilla (D-Calif.), Jeff Merkley(D-Ore.), and Ron Wyden (D-Ore.), along with U.S. Representative Suzanne Bonamici (D-Ore.-01), led 26 lawmakers in a BIPARTISAN LETTER demanding that Office of Management and Budget (OMB) Director Russell Vought and Education Secretary Linda McMahon immediately release $52.1 million in previously mandated funds for the High School Equivalency Program (HEP) and the College Assistance Migrant Program (CAMP), which support educational opportunities for students from agricultural farm worker families.Genera
