Proton exchange membrane electrolysis sustained by water vapor

The current–voltage characteristics of a proton exchange membrane (PEM) electrolyzer constructed with an IrRuOx water oxidation catalyst and a Pt black water reduction catalyst, under operation with water vapor from a humidified carrier gas, have been investigated as a function of the gas flow rate, the relative humidity, and the presence of oxygen. The performance of the system with water vapor was also compared to the performance when the device was immersed in liquid water. With a humidified Ar(g) input stream at 20 °C, an electrolysis current density of 10 mA cm^(−2) was sustained at an applied voltage of ~ 1.6 V, with a current density of 20 mA cm^(−2) observed at ~ 1.7 V. In the system evaluated, at current densities >40 mA cm^(−2) the electrolysis of water vapor was limited by the mass flux of water to the PEM. At <40 mA cm^(−2), the electrolysis of water vapor supported a given current density at a lower applied bias than did the electrolysis of liquid water. The relative humidity of the input carrier gas strongly affected the current–voltage behavior, with lower electrolysis current density attributed to dehydration of the PEM at reduced humidity values. The results provide a proof-of-concept that, with sufficiently active catalysts, an efficient solar photoelectrolyzer could be operated only with water vapor as the feedstock, even at the low operating temperatures that may result in the absence of active heating. This approach therefore offers a route to avoid the light attenuation and mass transport limitations that are associated with bubble formation in these systems

Exploring Multiscale Quantum Media: High-Precision Efficient Numerical Solution of the Fractional Schr\"odinger equation, Eigenfunctions with Physical Potentials, and Fractionally-Enhanced Quantum Tunneling

Fractional evolution equations lack generally accessible and well-converged codes excepting anomalous diffusion. A particular equation of strong interest to the growing intersection of applied mathematics and quantum information science and technology is the fractional Schr\"odinger equation, which describes sub-and super-dispersive behavior of quantum wavefunctions induced by multiscale media. We derive a computationally efficient sixth-order split-step numerical method to converge the eigenfunctions of the FSE to arbitrary numerical precision for arbitrary fractional order derivative. We demonstrate applications of this code to machine precision for classic quantum problems such as the finite well and harmonic oscillator, which take surprising twists due to the non-local nature of the fractional derivative. For example, the evanescent wave tails in the finite well take a Mittag-Leffer-like form which decay much slower than the well-known exponential from integer-order derivative wave theories, enhancing penetration into the barrier and therefore quantum tunneling rates. We call this effect \emph{fractionally enhanced quantum tunneling}. This work includes an open source code for communities from quantum experimentalists to applied mathematicians to easily and efficiently explore the solutions of the fractional Schr\"odinger equation in a wide variety of practical potentials for potential realization in quantum tunneling enhancement and other quantum applications

Role of Age and Sex in the Effects of Repeated Methamphetamine Exposure on Hedonic Tone in Sprague Dawley Rats

Anhedonia is defined as a reduced or complete loss of pleasure from a previously pleasurable stimulus, and it is comprised of two dimensions: Hedonic anhedonia consists of a distinct loss of pleasure in consumption of a normally pleasurable stimulus. Motivational anhedonia involves the goal directed behavior to obtain a reward. Withdrawal induced anhedonia following use of methamphetamine (METH) is thought to contribute to relapse behaviors1,2 . The anhedonic effects of drug withdrawal largely depend on dose, frequency, and the duration of drug exposure4,5,6. The role of sex and age of exposure in this context has yet to be elucidated

Repeated epitaxial growth and transfer of arrays of patterned, vertically aligned, crystalline Si wires from a single Si(111) substrate

Multiple arrays of Si wires were sequentially grown and transferred into a flexible polymer film from a single Si(111) wafer. After growth from a patterned, oxide-coated substrate, the wires were embedded in a polymer and then mechanically separated from the substrate, preserving the array structure in the film. The wire stubs that remained were selectively etched from the Si(111) surface to regenerate the patterned substrate. Then the growth catalyst was electrodeposited into the holes in the patterned oxide. Cycling through this set of steps allowed regrowth and polymer film transfer of several wire arrays from a single Si wafer

The Multiple Roles of Anticipation in Developmental Robotics

Anticipatory systems have been shown to be useful in discrete, symbolic systems. However, non­symbolic anticipatory systems are less well understood. In this paper, we explore the use of anticipation within the framework of connectionist networks to bootstrap from an innate behavior; to drive a reinforcement signal; and to provide feedback on the learnability of a task

The Multiple Roles of Anticipation in Developmental Robotics

Anticipatory systems have been shown to be useful in discrete, symbolic systems. However, non­symbolic anticipatory systems are less well understood. In this paper, we explore the use of anticipation within the framework of connectionist networks to bootstrap from an innate behavior; to drive a reinforcement signal; and to provide feedback on the learnability of a task

Long-term Trends and the Trophic Status of Conesus Lake 2012: A report to the Livingston County Planning Department Geneseo, NY

Conesus Lake monitoring conducted by personnel from The College at Brockport during the summer of 2012 determined the current trophic status of the lake and if any improvements or further degradation of water quality had occurred. To accomplish this goal, lake chemistry was monitored from 22 May to 14 August 2012 and the following were completed: a trophic state assessment of the lake and an evaluation of long-term trends in lake chemistry. Recommendations 1. The monitoring of Conesus Lake should continue. Current results suggest a slow improvement in it’s surface water. The status of the lake’s water quality has been an issue for many years. If it is indeed improving as suggested, this success story needs to be communicated to the general public. 2. The importance of managing nutrients and soil loss from the watershed is now even more important to prevent a relapse or return to less desirable conditions. Continuing efforts to reduce nutrient losses from sources in agriculture, from septic systems above the ring sewer, and from lawn fertilizers should be emphasized

Silicon and tungsten oxide nanostructures for water splitting

Inorganic semiconductors are promising materials for driving photoelectrochemical water-splitting reactions. However, there is not a single semiconductor material that can sustain the unassisted splitting of water into H_2 and O_2. Instead, we are developing a three part cell design where individual catalysts for water reduction and oxidation will be attached to the ends of a membrane. The job of splitting water is therefore divided into separate reduction and oxidation reactions, and each catalyst can be optimized independently for a single reaction. Silicon might be suitable to drive the water reduction. Inexpensive highly ordered Si wire arrays were grown on a single crystal wafer and transferred into a transparent, flexible polymer matrix. In this array, light would be absorbed along the longer axial dimension while the resulting electrons or holes would be collected along the much shorter radial dimension in a massively parallel array resembling carpet fibers on a microscale, hence the term "solar carpet". Tungsten oxide is a good candidate to drive the water oxidation. Self-organized porous tungsten oxide was successfully synthesized on the tungsten foil by anodization. This sponge-like structure absorbs light efficiently due to its high surface area; hence we called it "solar sponge"

A putative ariadne-like E3 ubiquitin ligase (PAUL) that interacts with the muscle-specific kinase (MuSK).

Formation of the postsynaptic membrane at the skeletal neuromuscular junction (NMJ) requires activation of the muscle-specific receptor tyrosine kinase (MuSK). Few intracellular mediators or modulators of MuSK actions are known. E3 ubiquitin ligases may serve this role, because activities of several receptor tyrosine kinases, G-protein-coupled receptors and channels are modulated by ubiquitination. Here, we report identification of a putative Ariadne-like ubiquitin ligase (PAUL) that binds to the cytoplasmic domain of MuSK. PAUL is expressed in numerous tissues of developing and adult mice, and is present at NMJs in muscle fibers but is not confined to them.Peer reviewe