Non-segregating electrolytes for molten carbonate fuel cells

Current MCFCs use a Li/K carbonate mixture; the segregation increases the K concentration near the cathode, leading to increase cathode solubility and performance decline. ANL is developing molten carbonates that have minimal segregation; the approach is using Li-Na carbonates. In screening tests, fully developed potential distributions were obtained for 4 Li/Na compositions, and performance data were used to compare these

Automated Intelligent Monitoring and the Controlling Software System for Solar Panels

The inspection of the solar panels on a periodic basis is important to improve longevity and ensure performance of the solar system. To get the most solar potential of the photovoltaic (PV) system is possible through an intelligent monitoring & controlling system. The monitoring & controlling system has rapidly increased its popularity because of its user-friendly graphical interface for data acquisition, monitoring, controlling and measurements. In order to monitor the performance of the system especially for renewable energy source application such as solar photovoltaic (PV), data-acquisition systems had been used to collect all the data regarding the installed system. In this paper the development of a smart automated monitoring & controlling system for the solar panel is described, the core idea is based on IoT (the Internet of Things). The measurements of data are made using sensors, block management data acquisition modules, and a software system. Then, all the real-time data collection of the electrical output parameters of the PV plant such as voltage, current and generated electricity is displayed and stored in the block management. The proposed system is smart enough to make suggestions if the panel is not working properly, to display errors, to remind about maintenance of the system through email or SMS, and to rotate panels according to a sun position using the Ephemeral table that stored in the system. The advantages of the system are the performance of the solar panel system which can be monitored and analyzed

Lithium-ferrate-based cathodes for molten carbonate fuel cells

Argonne National Laboratory is developing advanced cathodes for pressurized operation of the molten carbonate fuel cell (MCFC) at approximately 650 degrees Centigrade. These cathodes are based on lithium ferrate (LiFeO[sub 2]) which is attractive because of its very low solubility in the molten (Li,K)[sub 2]CO[sub 3] electrolyte. Because of its high resistivity, LiFeO[sub 2] cannot be used as a direct substitute for NiO. Cation substitution is, therefore, necessary to decrease resistivity. The effect of cation substitution on the resistivity and deformation of LiFeO[sub 2] was determined. The substitutes were chosen because their respective oxides as well as LiFeO[sub 2] crystallize with the rock-salt structure

Digital activism: After the hype

Research on digital activism has gained traction in recent years. At the same time, it remains a diverse and open field that lacks a coherent mode of inquiry. For the better or worse, digital activism remains a fuzzy term. In this introduction to a special issue on digital activism, we review current attempts to periodize and historicize digital activism. Although there is growing body of research on digitial activism, many contributions remain limited through their ahistorical approach and the digital universalism that they imply. Based on the contributions to the special issue, we argue for studying digital activisms in a way that traverses a two-dimensional axis of digital technologies and activist practices, striking the balance between context and media-specificity

Correlation of interfacial bonding mechanism and equilibrium conductance of molecular junctions

We report theoretical investigations on the role of interfacial bonding mechanism and its resulting structures to quantum transport in molecular wires. Two bonding mechanisms for the Au-S bond in an Au(111)/1,4-benzenedithiol(BDT)/Au(111) junction were identified by ab initio calculation, confirmed by a recent experiment, which, we showed, critically control charge conduction. It was found, for Au/ BDT/Au junctions, the hydrogen atom, bound by a dative bond to the Sulfur, is energetically non-dissociative after the interface formation. The calculated conductance and junction breakdown forces of H-non-dissociative Au/BDT/Au devices are consistent with the experimental values, while the H-dissociated devices, with the interface governed by typical covalent bonding, give conductance more than an order of magnitude larger. By examining the scattering states that traverse the junctions, we have revealed that mechanical and electric properties of a junction have strong correlation with the bonding configuration. This work clearly demonstrates that the interfacial details, rather than previously believed many-body effects, is of vital importance for correctly predicting equilibrium conductance of molecular junctions; and manifests that the interfacial contact must be carefully understood for investigating quantum transport properties of molecular nanoelectronics.Comment: 18 pages, 6 figures, 2 tables, to be appeared in Frontiers of Physics 9(6), 780 (2014

Efficiency of Energy Conversion in Thermoelectric Nanojunctions

Using first-principles approaches, this study investigated the efficiency of energy conversion in nanojunctions, described by the thermoelectric figure of merit $ZT$. We obtained the qualitative and quantitative descriptions for the dependence of $ZT$ on temperatures and lengths. A characteristic temperature: $T_{0}= \sqrt{\beta/\gamma(l)}$ was observed. When $T\ll T_{0}$, $ZT\propto T^{2}$. When $T\gg T_{0}$, $ZT$ tends to a saturation value. The dependence of $ZT$ on the wire length for the metallic atomic chains is opposite to that for the insulating molecules: for aluminum atomic (conducting) wires, the saturation value of $ZT$ increases as the length increases; while for alkanethiol (insulating) chains, the saturation value of $ZT$ decreases as the length increases. $ZT$ can also be enhanced by choosing low-elasticity bridging materials or creating poor thermal contacts in nanojunctions. The results of this study may be of interest to research attempting to increase the efficiency of energy conversion in nano thermoelectric devices.Comment: 2 figure

Conceptualizing a distributed, multi-scalar global public sphere through activist communication practices in the World Social Forum

This article contributes to debate about how to conceptualize the global public sphere. Drawing on media practice theory and ethnographic research on media activism in the World Social Forum, it shows how ‘global publics’ can be constituted through a diverse range of activist communication practices that complicate both conventional hierarchies of scale and contemporary theorizations of publics as personalized networks. It develops an understanding of the global public sphere as an emergent formation made up of multiple, interlinked publics at different scales and emphasizes the significance of collective communication spaces for actors at the margins of the global network society

Effect of Thermoelectric Cooling in Nanoscale Junctions

We propose a thermoelectric cooling device based on an atomic-sized junction. Using first-principles approaches, we investigate the working conditions and the coefficient of performance (COP) of an atomic-scale electronic refrigerator where the effects of phonon's thermal current and local heating are included. It is observed that the functioning of the thermoelectric nano-refrigerator is restricted to a narrow range of driving voltages. Compared with the bulk thermoelectric system with the overwhelmingly irreversible Joule heating, the 4-Al atomic refrigerator has a higher efficiency than a bulk thermoelectric refrigerator with the same $ZT$ due to suppressed local heating via the quasi-ballistic electron transport and small driving voltages. Quantum nature due to the size minimization offered by atomic-level control of properties facilitates electron cooling beyond the expectation of the conventional thermoelectric device theory.Comment: 8 figure

Connective Memory Work on Justice for Mike Brown

This chapter addresses what I term the "connective memory work" carried out on Facebook page dedicated to achieving justice for Michael Brown, an African America teenager whose death at the gun of white police officer Darren Wilson in early August 2014 led to the Ferguson protests. The chapter outlines four types of connective memory work evident on the page. These types include the ‘memetic resurrection’ that involved the appropriation of iconic historical imagery alongside those of networked commemoration, digital archiving and curation, and crowd reconstruction. Central to this contribution the call to rethink the digital memory work practices of activists so as to integrate a concern for the agency of social media platforms themselves.<br/