Selective C2+ Alcohol Synthesis from CO2 Hydrogenation via Reaction-Coupling Strategy

Higher alcohol synthesis (HAS) from non-petroleum carbon resources (a mixture of H2 and CO2) is an attractive but challenging research target. This reaction still suffers from poor higher alcohol (HA)...

NUMERICAL ANALYSIS OF HEAT TRANSFER AND CHEMICAL REACTION COUPLING IN THE RUBBER SEAL VULCANIZATION PROCESS

ABSTRACT Vulcanization parameters significantly affect the performance of rubber seals and the energy savings of the manufacturing process, which require a relationship between process parameters and vulcanization characteristics. Based on the vulcanization kinetics of rubber seal materials, a transient thermochemical-coupled finite-element model of the vulcanization process was established and solved. Changes in thermal conductivity and specific heat capacity during vulcanization were considered in detail. The effects of operational and structural parameters, such as mold temperature, heating duration, and rubber seal shape, cross-sectional dimensions on vulcanization characteristics were investigated. Finally, feasible suggestions for the vulcanization production of rubber seals are discussed. The study is expected to design parameters and control the vulcanization process of rubber seals accurately.

Density and size-dependent bioturbation effects of the infaunal polychaete Nephtys incisa on sediment biogeochemistry and solute exchange

The impact of bioturbation on the geochemistry of aquatic sediments is known to depend on the benthic infauna species that are present. However, burrowing and activity patterns of each species may also change during the different stages of a life cycle. In this study, we examined the effects of four size classes of the polychaete Nephtys incisa on burrow networks and sediment biogeochemistry. In our experimental aquaria, the total biovolume (~ biomass) of Nephtys was kept constant, but different age classes were introduced, so the size and abundance varied between treatments. Despite differences in the geometry of burrow networks (due to varying density and size of burrows as revealed by X-radiography), the transport of nonreactive solutes (Br–) showed little difference between treatments. In contrast, the depth distribution of reactive solutes (Fe2+, Mn2+, TPO3– 4, TCO2, O2, pH) depended on oxidized sediment volumes and on spatial micro-heterogeneity related to burrowing patterns. Net fluxes of O2, TCO2, and NO– 3 fluxes were strongly affected by age-dependent burrowing patterns. Carbonate dissolution and remineralization rates (reflected by TCO 2fluxes) were enhanced as the size of individuals increased. NO– 3fluxes showed progressive change from dominance of nitrification (release) to denitrification (uptake) as burrow densities decreased with larger individuals. We conclude that different age-size classes of a single species at identical biovolume affect biogeo- chemical cycling differently, due to changes in burrow sizes and burrow densities. Because of redox reaction coupling associated with burrow geometries (Fe2+, Mn2+ oxidation patterns), similar magnitudes of nonlocal transport may be a misleading indicator of biogenic impacts. Our observations demonstrate that biogeochemical impacts must be evaluated in the context of size (age-) specific traits and population densities rather than biomass or biovolume alone.

Self-Powered Flexible Sour Sensor for Detecting Ascorbic Acid Concentration Based on Triboelectrification/Enzymatic-Reaction Coupling Effect

Artificial sensory substitution systems can mimic human sensory organs through replacing the sensing process of a defective sensory receptor and transmitting the sensing signal into the nervous system. Here, we report a self-powered flexible gustation sour sensor for detecting ascorbic acid concentration. The material system comprises of Na2C2O4-Ppy with AAO modification, PDMS and Cu wire mesh. The working mechanism is contributed to the triboelectrification/enzymatic-reaction coupling effect, and the device can collect weak energy from body movements and directly output triboelectric current without any external power-units. The triboelectric output is affected by AA concentration, and the response is up to 34.82% against 15.625 mM/L of AA solution. Furthermore, a practical application in detecting ascorbic acid concentration of different drinks has been demonstrated. This work can encourage the development of wearable flexible electronics and this self-powered sour sensor has the potential that can be acted as a kind of gustatory receptors to build electronic tongues.

Understanding the high performance of PdSn-TaN(tantalum nitride)/C electrocatalysts for methanol oxidation reaction: coupling the nitrides and oxophilic elements

The core-shell like PdSn-TaN(tantalum nitride)/C catalysts with tunable oxophilicity were prepared through a surfactant-free solvothermal method. The optimized Pd1Sn3-TaN/C exhibited good activity (3293.46 A gPd-1, 15.6 times that of the...