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Metal-Organic-Framework-Derived Atomically Dispersed Mn-N-C Electrocatalysts Boosting Oxygen Reduction Modulated by Anion Exchange of Permanganate
No full textMn-N-C materials have received increasing interest in recent years because of their low Fenton reactivity and ORR activity comparable to those of their Fe-N-C and Co-N-C counterparts. In this contribution, an atomically dispersed Mn-N-C electrocatalyst with a prominent oxygen reduction performance was constructed by employing a cationic Cd-MOF as a precursor that can facilely and accurately introduce MnO-4 anions through anion exchange. The best-performing Mn-N-C catalyst displays a 0.96 V (vs RHE) Eonset (onset potential) and a 0.87 V (vs RHE) E1/2 (half-wave potential) in an alkaline solution, which exceed those of the benchmark Pt/C catalyst. In particular, the maximal power density of the self-made zinc-air battery reaches 200 mW.cm-2, surpassing that of most reported Mn-N-C materials
Recent Advances in Biopolymer-Based Hydrogel Electrolytes for Flexible Supercapacitors
No full textGrowing concern regarding the impact of fossil fuels has led to demands for the development of green and renewable materials for advanced electrochemical energy storage devices. Biopolymers with unique hierarchical structures and physicochemical properties, serving as an appealing platform for the advancement of sustainable energy, have found widespread application in the gel electrolytes of supercapacitors. In this Review, we outline the structure and characteristics of various biopolymers, discuss the proposed mechanisms and assess the evaluation metrics of gel electrolytes in supercapacitor devices, and further analyze the roles of biopolymer materials in this context. The state-of-the-art electrochemical performance of biopolymer-based hydrogel electrolytes for supercapacitors and their multiple functionalities are summarized, while underscoring the current technical challenges and potential solutions. This Review is intended to offer a thorough overview of recent developments in biopolymer-based hydrogel electrolytes, highlighting research concerning green and sustainable energy storage devices and potential avenues for further development
Novel Biobased Non-Isocyanate Polyurethanes from Microbially Produced 7,10- Dihydroxy-8(E)-Octadecenoic Acid for Potential Packaging and Coating Applications.
No full textIn this study, a green and sustainable strategy was opted for the synthesis of a novel biobased non-isocyanate polyurethane (NIPU) or polyhydroxy urethane (PHU). NIPU or PHU was synthesized from microbially converted hydroxy fatty acid-based cyclic carbonate and diamine cross-linker. Initially, oleic acid was biotransformed into 7,10- dihydroxy-8(E)-octadecenoic acid (DOD) using Pseudomonas aeruginosa. The cell-free approach was chosen for DOD production due to its high yield and productivity. Afterward, DOD was modified into DOD-based tricyclic carbonate by a two-step method. The prepared monomeric material was characterized using Fourier transform infrared (FTIR) spectroscopy, 1 H nuclear magnetic resonance (1 H NMR), and 13C NMR analyses. A series of DOD-based PHUs (DOD PHUs) were synthesized with different amine contents, and their structures were studied by FTIR and 1 H NMR analyses. The morphological, mechanical, and thermal properties of DOD PHU were further analyzed. The tensile strength and elongation at the break of the prepared DOD PHU were in the range of 2-6 MPa and 39-76%, respectively. The glass transition temperature of the material was in the range of 4-27 C. Thermogravimetric analysis exhibited that thermal stability increases with the increase in amine content. The gel content was in the range of 73-100%, suggesting that the polymers are highly cross-linked. In addition, the synthesized DOD PHU displayed excellent ultraviolet and water resistance properties. The green synthesized DOD PHU depicts suitability for a wide range of applications, particularly in the coating and packaging industries
Fully Biobased Self-Healing and Recyclable Covalent Adaptable Networks Prepared via a Catalyst-Free Aza-Michael Reaction
No full textIn the present scenario, petroleum resource-based thermoset materials have become an environmental threat due to their permanent cross-linked structure that limits their recyclability. To overcome this problem, the development of covalent adaptable networks (CANs) containing dynamic covalent bonds has emerged in recent years that can be recycled under suitable conditions. However, the development of fully biobased as well as recyclable CANs following a green synthetic protocol is yet a great challenge and a dream toward a sustainable environment. With this goal, here, we report the development of fully biobased CAN films from acrylated castor oil (a low-cost vegetable oil derivative) and cystamine (a biobased diamine) via a catalyst-free aza-Michael reaction using disulfide linkage as the dynamic covalent bond. The CAN films show excellent thermoself-healing behavior and recyclability for at least 10 cycles while maintaining their material properties. In addition, the CAN films can be catalytically degraded, which can be further reprocessed to reconstruct the films. Furthermore, the CAN films are hydrophobic in nature, indicating that these biobased recyclable CAN films are useful for protective surface coating applications. Therefore, as a proof of concept, we further demonstrate the anticorrosive properties of a film having a maximum water contact angle of 102.4°, analyzed by a polarization method, electrochemical impedance, and a salt spray fog test under a corrosive environment. This work provides an economical as well as environmentally friendly route to develop multifunctional materials for a sustainable future
EPOXIDIZED CASTOR OIL BASED THERMOSETS WITH REPROCESSABLE AND NON REPROCESSABLE PROPERTIES
Get PDFCastor oil-based polymers have gained significant attention due to their renewable nature, low cost, and ease of processing, making them ideal for various applications, including biofuels and the petrochemical industry. Among these, epoxidized castor oil (ECO)-based thermosets have been extensively studied for their promising mechanical and thermal properties. This study focuses on recent advancements in ECO thermosets synthesized with 4,4-dithiodianiline (DTDA) which has aromatic disulfide bonds and 4,4-ditaminodiphenylmethane (DMPM) which has methylene bridge. FTIR spectroscopy confirmed the successful incorporation of epoxy functionalities into castor oil. The structure-reactivity relationship was examined through differential scanning calorimetry (DSC), which reveals that ECO_DMPM based thermosets exhibit higher glass transition (Tg) range compared to ECO_DTDA due to methylene group. Thermogravimetric analysis (TGA). Indicates good thermal stability across all thermosets, with degradation onset temperatures above 350°C, though the presence of sulfur bonds may slightly reduce thermal stability. Tensile testing, GEL fraction measurements, and These assessments revealed strong correlations between monomer reactivity and final material properties. Moreover, the study highlighted the non-reprocessable nature of the ECO_DMPM thermosets. distinguishing them from other sustainable polymer systems. Their highly crosslinked structures limit recyclability but enhance their thermal and mechanical stability. The inclusion of dynamic disulfide bonds of ECO_DTDA introduces the potential for reprocess ability, allowing the thermosets to be reshaped without significant loss of performance. This research underscores the potential of ECO-based thermosets with customizable properties, offering promising applications in sectors such as automotive, coatings, and composites. The materials\u27 reprocessability and use of renewable resources provide an avenue for sustainable alternatives to traditional petroleum-based thermosets, aligning with the increasing demand for eco-friendly solutions in modern industries
Robert Blunk, Jr.
No full textPhotograph of a faculty member who served as an editor to the Midwest Quarterlyhttps://digitalcommons.pittstate.edu/yearbookphotos/1050/thumbnail.jp
Implementing the Congressional District Electoral Method in All States
No full textThe congressional district method is currently used by Nebraska and Maine to award each state\u27s electoral votes based on the popular vote winner in individual congressional districts, rather than the state\u27s overall popular vote winner. This system is superior to winner-take-all, therefore all fifty states should join Nebraska and Maine in using the congressional district method. With voters in the United States demanding changes to the electoral college system, the congressional district method provides a fair compromise that satisfies the demands for reform. Additionally, the congressional district method provides better representation to all voters compared to the current electoral college system. Due to better representation, all fifty states implementing the congressional district method would increase voter turnout across the country, as shown in Nebraska and Maine. It would also equalize power between states by eliminating the disproportionate influence held by swing states and ensuring the issues of voters in all states are equally important to presidential candidates. Finally, implementing the congressional district method should receive bipartisan support, as it makes elections fairer overall and does not disproportionally benefit either political party. While there are some possible drawbacks to the congressional district method, such as the risk for gerrymandering and an increase in presidential campaigns costs, the benefits of this electoral method are far greater than the potential issues. The congressional district should be implemented across all fifty states to give every voter a voice in presidential elections and to satisfy the demand for electoral college reform
An Empirical Analysis of Factors Influencing Crime Rates in the United States
No full textCriminality has long been a significant component of society, shaping how people develop and improve legislation. It is a major concern for both public authorities and citizens, making the question of what drives individuals to engage in illegal activities a central issue. This study investigates the key factors influencing crime rates in the United States, with the objective of providing empirical evidence and actionable suggestions for reducing crime rates. This research builds upon existing literature by examining factors such as public police expenditure, real GDP, and poverty rate. Data was collected from sources like the Uniform Crime Report, U.S. Census, American Community Survey, and FRED for the period 1995-2020. An Ordinary Least Squares (OLS) regression analysis was then conducted.
The findings indicate that increased government expenditure on policing has a significant negative impact on crime rates, suggesting that stronger law enforcement efforts contribute to crime reduction. Conversely, the unemployment rate shows a positive correlation with crime, reinforcing the idea that economic hardship drives criminal activity. These results provide valuable insights for policymakers, suggesting that a balanced approach-combining effective policing with economic initiatives-may yield the best outcomes for crime prevention
Smoke Savvy Automated Pellet Smoker
No full textSmoke Savvy is a user-friendly, high-quality automated pellet meat smoker. Smoke Savvy monitors the average temperature of the meat chamber, the internal temperature of the meat being cooked inside the meat chamber, and the quality of the smoke circulating throughout the meat chamber. In addition to monitoring, Smoke Savvy also controls the internal temperature of the meat chamber and the quality of smoke in the meat chamber. Smoke Savvy controls the temperature of the meat chamber using a PID control system that calculates the pellet feed rate and intake fan speed to maintain the meat chamber temperature at the user\u27s desired setpoint. Smoke Savvy similarly controls the smoke quality, using a PID control system that calculates the intake fan speed and the output damper position to maintain smoke particles in the blue smoke level
Breeding Ecology of Prothonotary Warblers on Abandoned Mined Lands
No full textThe Prothonotary Warbler is a Neotropical migrant songbird that nests in tree cavities in forested wetlands. Despite population declines due to habitat loss in the core of their geographic range, prothonotary warblers may be expanding their range westward into Kansas, where woody encroachment and disturbance from past strip mining have resulted in extensive nesting habitat. The goal of this study is to assess population demographics on mined and unmined lands throughout the breeding season. In 2024, we located territories of prothonotary warblers and banded 4 individuals. Starting in December 2024, we placed 260 nest boxes on 8 mined and 8 unmined sites in SE Kansas and SW Missouri. Over the next two years, we will band all prothonotary warblers on all 16 sites and monitor their nest success. In addition, we are collaborating with several local Audubon chapters to attach geolocators to a subset of prothonotary warblers to study migration and dispersal patterns. Results from this study will allow us to compare occupancy rates, nest survival, and site fidelity across mined and unmined sites to determine the role these heavily disturbed ecosystems play for migratory songbirds