Architecture Technology Corporation (United States)

This study investigates the development of a nanostructured connected metaball (CMB) PtPd/C binary alloy electrocatalyst for the improved oxygen reduction reaction (ORR) performance in polymer electrolyte membrane fuel cells (PEMFCs). The catalyst was synthesized using a modified molten-salt method and characterized through various physical and electrochemical techniques. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the formation of connected metaballs of a PtPd alloy structure with an ∼8 nm metaball size. Electrochemical testing revealed that the CMB PtPd/C electrocatalyst exhibited 10 times enhanced mass (Im) activity and 5 times specific (Is) activity than Pt/C, respectively. The enhanced performance is attributed to the connected spheres of PtPd alloys and synergistic effects among the constituent elements. Notably, the nanostructured CMB network catalyst demonstrated excellent stability, maintaining high activity for up to 60,000 potential cycles before the gradual decline. CO stripping voltammetry indicated a positive shift in the CO oxidation onset potential, correlating with the improved ORR activity. The results suggest that connected metaballs of the PtPd/C system create a more active and durable ORR catalyst. This geometry approach offers a promising direction for developing high-performance, low-platinum content catalysts for PEMFC applications.

1. A new multiport profile system simplifies examining the CO2 and H2O storage terms. 2. Neglecting canopy storage terms leads to inaccuracies in crop energy balance closure. 3. Energy closure is improved if canopy storage is considered. 4. The multiport system is necessary for eddy covariance-derived fluxes over maize canopy.

Abstract Measurements of atmospheric ammonia (NH3) concentrations and fluxes are limited in coastal regions in the eastern U.S. In this study, continuous and high temporal resolution measurements (5s) of atmospheric NH3 concentrations were recorded using a cavity ring‐down spectrometer in a temperate tidal salt marsh at the St Jones Reserve (Dover, DE). Micrometeorological variables were measured using an eddy covariance system which is part of the AmeriFlux network (US‐StJ). Soil, plant, and water chemistry were also analyzed to characterize the sources and sinks of atmospheric NH3. A new analytical methodology was used to estimate the average ecosystem‐scale diurnal cycle of NH3 fluxes by replicating the characteristics of a chamber experiment. This virtual chamber approach estimates positive surface fluxes in continuing strongly stable conditions when mixing with the air above is minimal. Our findings show that tidal water level may have a significant impact on NH3 emissions from the marsh. The largest fluxes were observed at low tide when more soil was exposed. While it is expected that NH3 fluxes will peak when the air temperature maximizes, high tide occurred concurrently with midday peaks in solar irradiance led to a decrease in NH3 fluxes. Furthermore, soil, plant, and water chemistry measurements underpinning the NH3 concentrations and fluxes lead us to conclude that this coastal wetland ecosystem can act as either a sink or a source of NH3. Such measurements provide novel data on which we can base reliable parameterizations to simulate NH3 emissions from coastal salt marsh ecosystems using surface‐atmosphere transfer models.

While the literature is clear about excessive tillage decreasing soil carbon (C) content, there are few experimental studies that document the comparative effects of soil and crop management on C sequestration. Using micrometeorology we measured CO2 flux from a maize crop grown on both no-till and tilled soils in north-central Ohio. We used Bowen Ratio Energy Balance (BREB) systems to quantify the flux between the atmosphere and either the soil surface (at crop planting) or 0.2 m above the canopy once the crop was established and growing. The no-till plot sequestered 263 g CO2 m-2 (90% confidence interval -432.1 to -99.9) while the tilled plot emitted 146 g CO2 m-2 (90% confidence interval -53.3 to 332.2) during 104 days of the 2015 growing season; a net difference of 410 g CO2 m-2. The difference is statistically significant at the 90% confidence level (based on a bootstrap analysis). The results indicate that no-tillage practices can sequester C, maintain soil productivity, and ensure landscape sustainability.

This special issue of IT Professional focuses on the graph database. The graph database, a relatively new phenomenon, is well suited to the burgeoning information era in which we are increasingly becoming immersed. Here, the guest editors briefly explain how a graph database works, its relation to the relational database management system (RDBMS), and its quantitative and qualitative pros and cons, including how graph databases can be harnessed in a hybrid environment. They also survey the excellent articles submitted for this special issue.

Traditional endpoint protection will not address the looming cybersecurity crisis because it ignores the source of the problem--the vast online black market buried deep within the Internet.

For the last few decades, there was tremendous interest in harnessing 3D virtual environments for education and training. Multi-user game-like environments make use of non-player characters and quest activities in tutoring and training. This approach incorporates successful active learning and incremental progress. This article presents issues encountered while adapting the multi-user online game genre for educational virtual environments. In this endeavour, non-player characters play a central role in organising and delivering educational content. Educational virtual environments call for additional kinds of extension beyond generic user content creation as delivered in some virtual worlds like Second Life. Support for these environments will emphasise the creation of new activities. A set of libraries and techniques named portable non-player character tutors and quests reduces the effort needed to develop and integrate educational non-player characters. These non-player characters are introduced in CVE, a platform for rapidly developing educational virtual environments. The portable non-player character tutors and quests framework enables formatted web-based exercises, quizzes, and educational content to be incorporated into virtual worlds, reducing the effort needed to create new content. The framework presented in this article introduces initial non-player characters that support educational quest activities to the 3D environments users.

Crypto-currency remains controversial, and Bitcoin, a leading open source initiative to create an alternative form of currency, is at the center of this controversy. Here, the author provides an update to the state of Bitcoin in particular, and examines the future of crypto-currency in general.

Graph databases are a relatively new database technology gaining popularity. This article explores the value of graph databases and probes some of their security and privacy implications.