Plasma-Enhanced Catalytic Synthesis of Ammonia over a Ni/AlO Catalyst at Near-Room Temperature: Insights into the Importance of the Catalyst Surface on the Reaction Mechanism.

A better fundamental understanding of the plasma-catalyst interaction and the reaction mechanism is vital for optimizing the design of catalysts for ammonia synthesis by plasma-catalysis. In this work, we report on a hybrid plasma-enhanced catalytic process for the synthesis of ammonia directly from N and H over transition metal catalysts (M/AlO, M = Fe, Ni, Cu) at near room temperature (∼35 °C) and atmospheric pressure. Reactions were conducted in a specially designed coaxial dielectric barrier discharge (DBD) plasma reactor using water as a ground electrode, which could cool and maintain the reaction at near-room temperature.

Opportunistic Infections in Biological Therapy, Risk and Prevention.

Patients being treated with biological therapies are at increased risk for serious infections, including opportunistic infections. Although more is known about opportunistic infection risk with older biologics, such as antitumor necrosis factor drugs, there is less knowledge of opportunistic infection risk with newer biological therapies. The incidence of certain opportunistic infections (tuberculosis, herpes zoster, pneumocystosis) has been rigorously evaluated in large observational studies.

Surface protein gradients generated in sealed microchannels using spatially varying helium microplasma.

Spatially varied surface treatment of a fluorescently labeled Bovine Serum Albumin (BSA) protein, on the walls of a closed (sealed) microchannel is achieved via a well-defined gradient in plasma intensity. The microchips comprised a microchannel positioned in-between two microelectrodes (embedded in the chip) with a variable electrode separation along the length of the channel. The channel and electrodes were 50 μm and 100 μm wide, respectively, 50 μm deep, and adjacent to the channel for a length of 18 mm.

Temperature-dependent stochastic dynamics of the Huber-Braun neuron model.

The response of a four-dimensional mammalian cold receptor model to different implementations of noise is studied across a wide temperature range. It is observed that for noisy activation kinetics, the parameter range decomposes into two regions in which the system reacts qualitatively completely different to small perturbations through noise, and these regions are separated by a homoclinic bifurcation. Noise implemented as an additional current yields a substantially different system response at low temperature values, while the response at high temperatures is comparable to activation-kinetic noise.

Role of positive ions in determining the deposition rate and film chemistry of continuous wave hexamethyl disiloxane plasmas.

New data shed light on the mechanisms of film growth from low power, low pressure plasmas of organic compounds. These data rebalance the widely held view that plasma polymer formation is due to radical/neutral reactions only and that ions play no direct role in contributing mass at the surface. Ion reactions are shown to play an important role in both the plasma phase and at the surface.

Optimized synchronization of chaotic and hyperchaotic systems.

A method of synchronization is presented which, unlike existing methods, can, for generic dynamical systems, force all conditional Lyapunov exponents to go to -∞ . It also has improved noise immunity compared to existing methods, and unlike most of them it can synchronize hyperchaotic systems with almost any single coupling variable from the drive system. Results are presented for the Rossler hyperchaos system and the Lorenz system.

Modeling and detecting localized nonlinearity in continuum systems with a multistage transform.

A general method is presented for modeling spatially extended systems that may contain a localized source of nonlinearity. It has direct applications to structural health monitoring (SHM) where physical damage may cause such nonlinearity and also communications channels which may exhibit localized nonlinearity due to bad electrical contacts or component nonlinearity. The method uses a multistage nonlinear transform in order to model the system dynamics.

Buffer Standards for the Physiological pH of the Zwitterionic Compound, ACES from 5 to 55°C.

The values of the second dissociation constant p and related thermodynamic quantities of [N-(2-acetamido)-2-aminoethanesulfonic acid] (ACES) have already been reported over the temperature range 5 to 55°C including 37°C. This paper reports the pa values of four chloride ion free buffer solutions and eight buffer solutions with = 0.16 mol·kg , matching closely to that of the physiological sample.

Parameter and state estimation of experimental chaotic systems using synchronization.

We examine the use of synchronization as a mechanism for extracting parameter and state information from experimental systems. We focus on important aspects of this problem that have received little attention previously and we explore them using experiments and simulations with the chaotic Colpitts oscillator as an example system. We explore the impact of model imperfection on the ability to extract valid information from an experimental system.

Temporal evolution of an electron-free afterglow in the pulsed plasma polymerisation of acrylic acid.

By use of time and energy-resolved mass spectrometry, negative ions with masses ranging from m/z = 1-287 amu have been observed in the afterglow of a low-pressure (10 mTorr) pulsed acrylic acid polymerizing plasma. The most intense peaks, seen at m/z = 71, 143, 215, and 287, are assigned to the dehydrogenated oligomer of the form [nM-H](-) for n = 1, 2, 3, and 4, respectively. The results strongly suggest that both m/z = 71 and 143 ions are produced in the on period of the pulse cycle (0.

Second-generation proximally coated titanium femoral component: minimum 7-year results.

It is unclear whether resurfacing or fully porous-coated or proximally coated stems are the best femoral components for young patients. First-generation proximally coated titanium fiber-metal femoral components had a high rate of failure. We prospectively followed 56 patients (70 hips) whom we believed were at high risk for loosening of a cemented femoral component; all patients were implanted with one second-generation proximally coated titanium femoral component.