• Energy Research
• 2016-2025close
• 7. Clean energy close
• 2. Zero hunger close
• 9. Industry and infrastructure close
• University of North Texas close

Abstract Lignin is considered as a renewable and sustainable resource for producing value-added aromatic chemicals and functional carbon materials. Herein, we develop a one-step catalyst-free depolymerization strategy to convert lignin into aryl monomers and carbon nanospheres simultaneously. Importantly, microwave-assisted depolymerization (MAD) in conjunction with dichloromethane (CH2Cl2) vapors is developed. The total mass yield of guaiacols reached the highest amount of 225.1 mg/g at 600 °C, and the highest yields of phenols (49.0 mg/g) and aromatic hydrocarbons (155.1 mg/g) were obtained at 700 °C. Hydrogen radicals and hydrogen chloride (HCl) are in-situ formed from CH2Cl2, significantly decreasing the activation barrier and reforming pyrolysis vapors to promote the formation of aryl monomers. Interestingly, uniform carbon nanospheres with an average size of 140 nm were produced as co-products at 700 °C. The microwave “hot-spots”, allied with the continuous surface erosion and the decrease in surface energy of lignin-derived carbon precursors by CH2Cl2 vapor, can be considered the driving force for the ultimate formation of carbon nanospheres. The CH2Cl2/MAD system produces aryl monomers (26.8 wt% yield) and carbon nanospheres (36.6 wt% yield) at 700 °C. We provide a facile, intriguing and scalable approach to convert lignin to valuable aryl monomers and sustainable carbon materials that can be applied in the chemistry, energy and environmental fields.

The processing of graphene coated NiO–Ni anode using one CVD system delivered high Li-ion battery performance.

Abstract Commercially available lightweight-flexible CIGS solar cells are investigated under the Low-Intensity-Low-Temperature (LILT) conditions that exist at Mars, Jupiter, and Saturn. Current density-voltage measurements, concentrated solar, and external quantum efficiency measurements are performed under varying temperatures and illumination intensities to determine the applicability and performance of flexible CIGS in outer planetary conditions. The well-known metastability of the CIGS absorber is observed as a result of a barrier to minority carrier extraction at the CIGS/CdS interface under higher intensity illumination. However, despite the low temperatures and low intensities experienced in deeper space, the presence of this barrier does not significantly affect the performance of the solar cells under LILT conditions. This is attributed to the lower photogeneration rate of carriers particularly at conditions relative to Saturn and Jupiter, which appears to be less than the thermionic emission rate across the barrier and therefore the carrier extraction is relatively unaffected under these illumination conditions. At elevated temperatures and/or intensities such as at AM0 and conditions relative to Mars, however, the higher carrier generation rate results in the appearance of large series resistance and a significant loss of fill factor at irradiation levels greater than 1-sun AM0. Proton irradiation of the solar cells systematically reduces the performance, predominately through the formation of defect states in the absorber layer, the presence of which is increasingly more prohibitive in LILT conditions due to the low thermal energy of the minority carriers and the subsequent increased effect of SRH recombination.

Lower-cost alternatives to platinum electrocatalysts are being explored for the sustainable production of hydrogen, but often trial-and-error approaches are used for their development. Now, principles are elucidated that suggest pathways to rationally design efficient metal-free electrocatalysts based on doped graphene.

Machine to Machine (M2M) is a term used to describe the technologies that enable computers, embedded processors, smart sensors, actuators and mobile devices to communicate with one another, take measurements and make decisions--often without human intervention. M2M technology was applied to five commercial buildings in a test. The goal was to reduce electric demand when a remote price signal rose above a predetermine price. In this system, a variable price signal was generated from a single source on the Internet and distributed using the meta-language, XML (Extensible Markup Language). Each of five commercial building sites monitored the common price signal and automatically shed site-specific electric loads when the price increased above predetermined thresholds. Other than price signal scheduling, which was set up in advance by the project researchers, the system was designed to operate without human intervention during the two-week test period. Although the buildings responded to the same price signal, the communication infrastructures used at each building were substantially different. This study provides an overview of the technologies used at each building site, the price generator/server, and each link in between. Network architecture, security, data visualization and site-specific system features are characterized. The results of the test are discussed, including: functionality at each site, measurement and verification techniques, and feedback from energy managers and building operators. Lessons learned from the test and potential implications for widespread rollout are provided.

The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

Abstract Climate change is causing an increase in the frequency and intensity of droughts, heat waves, and their combinations, diminishing agricultural productivity and destabilizing societies worldwide. We recently reported that during a combination of water deficit (WD) and heat stress (HS), stomata on leaves of soybean (Glycine max) plants are closed, while stomata on flowers are open. This unique stomatal response was accompanied by differential transpiration (higher in flowers, while lower in leaves) that cooled flowers during a combination of WD + HS. Here, we reveal that developing pods of soybean plants subjected to a combination of WD + HS use a similar acclimation strategy of differential transpiration to reduce internal pod temperature by approximately 4 °C. We further show that enhanced expression of transcripts involved in abscisic acid degradation accompanies this response and that preventing pod transpiration by sealing stomata causes a significant increase in internal pod temperature. Using an RNA-Seq analysis of pods developing on plants subjected to WD + HS, we also show that the response of pods to WD, HS, or WD + HS is distinct from that of leaves or flowers. Interestingly, we report that although the number of flowers, pods, and seeds per plant decreases under conditions of WD + HS, the seed mass of plants subjected to WD + HS increases compared to plants subjected to HS, and the number of seeds with suppressed/aborted development is lower in WD + HS compared to HS. Taken together, our findings reveal that differential transpiration occurs in pods of soybean plants subjected to WD + HS and that this process limits heat-induced damage to seed production.

Plastic packaging dominates the US grocery industry. This realization raises the question of whether consumers are purchasing food that is not wrapped in conventional plastic but environmentally friendly packaging. This quantitative study adapted the Theory of Planned Behavior to investigate the relationship between consumers’ socio-demographics, purchase intention, and purchasing behavior regarding environmentally friendly grocery packaging. The survey was distributed through Qualtrics, and a sample of 487 eligible US grocery consumers was gathered. The study uncovers some novel findings. First, the results suggest that consumers’ subjective norms substantially stimulate environmentally friendly grocery packaging purchase intentions, influencing actual purchasing behavior. Second, we discovered that purchase intention and perceived behavioral control are likely working in conjunction to help bridge the intention-behavior gap in environmentally friendly consumption. Third, this study supplied a fresh perspective on socio-demographics’ role in environmentally friendly consumption, confirming that predominantly younger, unmarried consumers are more prone to purchase grocery items packaged in environmentally friendly materials. We hope that these study findings provide marketers with fresh insights into the characteristics of consumers willing to purchase grocery items packaged in environmentally friendly materials.