The effect of desiccation on the emission of volatile bromocarbons from two common temperate macroalgae

Exposure of intertidal macroalgae during low tide has been linked to the emission of a variety of atmospherically-important trace gases into the coastal atmosphere. In recent years, several studies have investigated the role of inorganic iodine and organoiodides as antioxidants and their emission during exposure to combat oxidative stress, yet the role of organic bromine species during desiccation is less well understood. In this study the emission of dibromomethane (CH2Br2) and bromoform (CHBr3) during exposure and desiccation of two common temperate macroalgae, Fucus vesiculosus and Ulva intestinalis, is reported. Determination of the impact exposure may have on algal physiological processes is difficult as intertidal species are adapted to desiccation and may undergo varying degrees of desiccation before their physiology is affected. For this reason we include comparisons between photosynthetic capacity (Fv/Fm) and halocarbon emissions during a desiccation time series. In addition, the role of rewetting with freshwater to simulate exposure to rain was also investigated. Our results show that an immediate flux of bromocarbons occurs upon exposure, followed by a decline in bromocarbon emissions. We suggest that this immediate bromocarbon pulse may be linked to volatilisation or emissions of existing bromocarbon stores from the algal surface rather than the production of bromocarbons as an antioxidant response

Pulmonary surfactant inhibition following cardiopulmonary bypass

Following cardiopulmonary bypass (CPB) patients exhibit varying amounts of pulmonary dysfunction. This study examined the possibility that plasma which leaked into the alveoli could cause a reduction in the ability of pulmonary surfactant to reach very low surface tension (surfactant inhibition). The possibility that CPB could cause an increase in any component of plasma which might inhibit surfactant function was also examined. Plasma from adult and child patients was tested. Surfactant was prepared from pig lungs. Surfactant function was measured as ability to lower surface tension on a Langmuir-Wilhelmy balance. Plasma from normals and CPB patients before and after bypass was mixed with pig surfactant and tested on the balance. The surface load of surfactant was constant while the amount of plasma was varied. -- Plasma from normals, adult patients and child patients inhibited the surfactant. Serum, fibrinogen, albumin and globulins also inhibited surfactant in this assay. The amount of inhibition was proportional to the amount of protein added. No increased inhibition was seen in post-bypass vs. pre-bypass samples in adults or children. Inhibitor(s) are present in normal plasma and do not appear to be increased by the bypass procedure. It is possible that plasma components entering airspaces through leaking lung membranes may inhibit surfactant from proper function, and may contribute to lung collapse and edema seen in the ARDS of any etiology. -- The nature of the inhibition was examined by characterization of the inhibitor and by studying models of protein-surfactant interaction on the surface balance

Underpriced Default Spread Exacerbates Market Crashes

In this paper, we develop a specific observable symptom of a banking system that underprices the default spread in non-recourse asset-backed lending. Using three different data sets for 18 countries and property types, we find that, following a negative demand shock, the “underpricing” economies experience far deeper asset market crashes than economies in which the put option is correctly priced. Furthermore, only one of the countries in our sample continues to exhibit the underpricing symptom following a market crash. This indicates that market crashes have a cleansing effect and eliminate underpricing at least for a period of time. This makes investing in such markets safer following a negative demand shock.real estate bubble, lender optimism, disaster myopia, Asian financial crisis

Error Voltage Components in Quantitative Voltage Contrast Measurement Systems

This paper presents the results of computer simulation studies into the respective contributions of the potential barrier, the off-normal incidence injection of secondary electrons (SEs) into the retarding field and analyser geometry on Types I and II local field error voltages for a practical 20 mm wide planar retarding field energy analyser. Results show that the error voltage component due to the off-normal incidence injection effect of SEs into the retarding field dominates the Type I local field error. For type II LFE, the error voltage component due to analyser geometry effect is the higher contributing factor. The presence of a neighbouring electrode voltage tends to draw SEs away from the central axis of the energy analyser, thus causing the electron trajectories to be more sensitive to the influence of the analyser geometry

New method for analytical photovoltaic parameters identification: meeting manufacturer’s datasheet for different ambient conditions

At present, photovoltaic energy is one of the most important renewable energy sources. The demand for solar panels has been continuously growing, both in the industrial electric sector and in the private sector. In both cases the analysis of the solar panel efficiency is extremely important in order to maximize the energy production. In order to have a more efficient photovoltaic system, the most accurate understanding of this system is required. However, in most of the cases the only information available in this matter is reduced, the experimental testing of the photovoltaic device being out of consideration, normally for budget reasons. Several methods, normally based on an equivalent circuit model, have been developed to extract the I-V curve of a photovoltaic device from the small amount of data provided by the manufacturer. The aim of this paper is to present a fast, easy, and accurate analytical method, developed to calculate the equivalent circuit parameters of a solar panel from the only data that manufacturers usually provide. The calculated circuit accurately reproduces the solar panel behavior, that is, the I-V curve. This fact being extremely important for practical reasons such as selecting the best solar panel in the market for a particular purpose, or maximize the energy extraction with MPPT (Maximum Peak Power Tracking) methods

Dopant concentration imaging in crystalline silicon wafers by band-to-band photoluminescence

In this work, we present two techniques for spatially resolved determination of the dopant density in silicon wafers. The first technique is based on measuring the formation rate of iron-acceptor pairs, which is monitored by band-to-band photoluminescence in low injection. This method provides absolute boron concentration images on p-type wafers, even if compensating dopants such as phosphorus are present, without reference to other techniques. The second technique is based on photoluminescence images of unpassivated wafers, where the excess carrier concentration is pinned by a high surface recombination rate. This rapid technique is applicable to either p- or n-type wafers, when the bulk carrier lifetime is much longer than the transit time to the surface. The relative sensitivities and advantages of the two techniques are discussed.This work has been supported by the Australian Research Council

References

www.biogeosciences-discuss.net/11/10673/2014/ doi:10.5194/bgd-11-10673-2014 © Author(s) 2014. CC Attribution 3.0 License. This discussion paper is/has been under review for the journal Biogeosciences (BG). Please refer to the corresponding final paper in BG if available. The effect of desiccation on the emission of volatile bromocarbons from two common temperate macroalga

Near-field MIMO communication links

A procedure to achieve near-field multiple input multiple output (MIMO) communication with equally strong channels is demonstrated in this paper. This has applications in near-field wireless communications, such as Chip-to-Chip (C2C) communication or wireless links between printed circuit boards. Designing the architecture of these wireless C2C networks is, however, based on standard engineering design tools. To attain this goal, a network optimization procedure is proposed, which introduces decoupling and matching networks. As a demonstration, this optimization procedure is applied to a 2-by-2 MIMO with dipole antennas. The potential benefits and design trade-offs are discussed for implementation of wireless radio-frequency interconnects in chip-to-chip or device-to-device communication such as in an Internet-of-Things scenario