An \u3cem\u3eIn Vitro\u3c/em\u3e Spectroscopic Analysis to Determine the Chemical Composition of the Precipitate Formed by Mixing Sodium Hypochlorite and Chlorhexidine

Introduction—The purpose of this in vitro study was to determine the chemical composition of the precipitate formed by mixing sodium hypochlorite (NaOCl) and Chlorhexidine (CHX), and relative molecular weight of the components. Methods—Using commercially available chlorhexidine gluconate (CHXg), a 2% solution was formed and mixed in a 1:1 ratio with commercially available NaOCl producing a brown precipitate. The precipitate as well as a mixture of precipitate and pure chlorhexidine diacetate (CHXa) was then analyzed using 1D and 2D NMR spectroscopy. Results—The 1D and 2D NMR spectra were fully assigned, in terms of chemical shifts of all proton and carbon atoms in intact CHX. This permitted identification of CHX breakdown products with and without the aliphatic linker present, including lower molecular weight components of CHX that contained a para-substituted benzene that was not para-chloroaniline (PCA). Conclusions—Based on this in vitro study, the precipitate formed by NaOCl and CHX is composed of at least two separate molecules, all of which are smaller in size than CHX. Along with native CHX, the precipitate contains two chemical fragments derived from CHX, neither of which are PCA

The Distributed Electronic Load Controller: A New Concept for Voltage Regulation in Microhydro Systems with Transfer of Excess Power to Households

AbstractConstant voltage and frequency can be generated by a stand-alone Self-Excited Induction Generator (SEIG) driven with a fixed-speed low-head hydro-turbine when the electrical load is maintained constant by an Electronic Load Controller (ELC). In a Conventional-ELC (C-ELC), usually a chopper with a dump load is used in parallel with the consumer loads to provide regulation of voltage and control of frequency. However, in the C-ELC configuration excess generated power may be wasted in a dump load. The objective of this research is to design a simplified ELC for each household to transfer the excess power for domestic consumption in addition to providing voltage regulation. Hence, a new ELC topology is proposed. This topology can be split into two parts. The first part is a regular ELC of low rated power, which should be installed at the generator site and it is responsible for precise voltage and frequency regulation and dealing with unexpected failure conditions. The second one is a simplified and inexpensive ELC which is installed in each household to direct excess power to a low wattage household apparatus in addition to participation in voltage regulation by maintaining constancy of the load power. This concept is referred to here as the Distributed ELC (DELC). One significant advantage of the proposed DELC approach is that the excess power can be utilized for domestic hot water purposes, and possibly resulting in health benefits related to improved sanitation. Moreover, the proposed topology shows more reliability compared with the C-ELC. Simulation results demonstrate that even with unbalanced three-phase loads (assisted with bi-directional switches per-phase), the proposed topology has the capability to regulate voltage from no-load to full load. Moreover, in the case of a failure in the power switches or the control circuits, the DELC has more reliable performance than a C-ELC

European farming and post-2013 CAP measures. A quantitative impact assessment

Following the paradigm for reforming the current CAP, the first objective of this study is to give insights into the economic impact of post-2013 CAP measures at different levels of aggregation (e.g. EU, Member State and region). The post-2013 CAP measures included are directed towards income for the farmers, competitiveness, valuable areas and ecosystem services. The second objective is to analyse the impact of a scenario that combines the above mentioned post-2013 CAP measures. This study can be seen as a first attempt to quantify the transition to a CAP with more targeted measures at the European level and reveals considerable methodological and data challenges. A key finding is that the impact of the various measures is very different with regard to various economic indicators.Agricultural and Food Policy,

Comparison of measured and EF5-r derived N₂O fluxes from a spring-fed river

There is considerable uncertainty in the estimates of indirect N₂O emissions as defined by the Intergovernmental Panel on Climate Change's (IPCC) methodology. Direct measurements of N₂O yields and fluxes in aquatic river environments are sparse and more data are required to determine the role that rivers play in the global N₂O budget. The objectives of this research were to measure the N₂O fluxes from a spring-fed river, relate these fluxes to the dissolved N₂O concentrations and NO₃–N loading of the river, and to try and define the indirect emission factor (EF5-r) for the river. Gas bubble ebullition was observed at the river source with bubbles containing 7.9 µL N₂O L⁻¹. River NO₃–N and dissolved N₂O concentrations ranged from 2.5 to 5.3 mg L⁻¹ and 0.4 to 1.9 µg N₂O-N L⁻¹ respectively with N₂O saturation reaching 404%. Floating headspace chambers were used to sample N₂O fluxes. N₂O–N fluxes were significantly related to dissolved N₂O–N concentrations (r² = 30.6) but not to NO₃–N concentrations. The N₂O–N fluxes ranged from 38-501 µg m⁻² h⁻¹, averaging 171 µg m⁻² h⁻¹ (± Std. Dev. 85) overall. The measured N₂O–N fluxes equated to an EF5-r of only 6.6% of that calculated using the IPCC methodology, and this itself was considered to be an over-estimate due to the degassing of antecedent dissolved N₂O present in the groundwater that fed the river

Porphyrin Layers at Cu/Au(111)–Electrolyte Interfaces: In Situ EC-STM Study

The coadsorption of porphyrin molecules (TMPyP: tetra(N-methyl-4-pyridyl)-porphyrin), sulfate anions and copper on a Au(111) electrode was investigated by the use of cyclic voltammetry (CV) and in situ electrochemical scanning tunneling microscopy. With decreasing electrode potential the following sequence of surface phases was found: (I) an ordered $$\left( {\sqrt 3 \times \sqrt 7 } \right)R19.1^\circ - {\text{S}}{{\text{O}}_4}^{{2 - }}$$ structure on the unreconstructed Au(111)-(1 × 1) surface; (II) a disordered SO42−-layer on the still unreconstructed Au(111)-(1 × 1); (III) a $$\left( {\sqrt 3 \times \sqrt 3 } \right)R30^\circ$$ coadsorption structure of 2/3 ML Cu and 1/3 ML SO42−; (IV) a completed 1 ML Cu covered by a layer of mobile, i.e. not imaged, SO42− anions, moreover, a coadsorption layer of disordered porphyrin molecules and still mobile SO42− anions; (V) overpotentially deposited Cu-multilayers terminated by the well known Moire-type modulated $$\left( {\sqrt 3 \times \sqrt 7 } \right)R19.1^\circ - {\text{S}}{{\text{O}}_4}^{{2 - }}$$ structure (similar to bulk Cu(111)) and covered by a dense layer of flat lying TMPyP molecules showing a growing square as well as hexagonally ordered arrangement, and at even more negative potential values and low Cu concentrations in the solution (VI) a pseudomorphic underpotentially deposited Cu-monolayer covered by a $$\left( {\sqrt 3 \times \sqrt 7 } \right)R19.1^\circ - {\text{S}}{{\text{O}}_4}^{{2 - }}$$ layer and a dense, ordered porphyrin layer ontop. The formation of the various phases is driven by the potential dependent surface charge density and the resultant electrostatic interaction with the respective ions. A severe imbalance between the copper deposition and desorption current in the CV spectra suggests also the formation of CuTMPyP-metalloporphyrin on the surface which diffuses into the bulk solution

Study on the Implications of Asynchronous GMO Approvals for EU Imports of Animal Feed Products

The aim of this study is to understand the implications of asynchronous approvals for genetically modified organisms (GMOs) that are imported to the European Union for use within animal feed products, specifically with regard to the EU livestock sector, as well as upon the upstream and downstream economic industries related to it. Asynchronous approval refers to the situation in which there is a delay in the moment when a genetically modified (GM) event – modifying a specific trait of a plant or animal – is allowed to be used in one country in comparison to another country. In the perspective of this study, the asynchronous GMO approvals concern the use of GM varieties of plants that are approved in the countries which supply them to the EU, in one form or another of feed material, before these are approved by the EU

Development of parasitic Maculinea teleius (Lepidoptera, Lycaenidae) larvae in laboratory nests of four Myrmica ant host species

Maculinea butterflies are social parasites of Myrmica ants. Methods to study the strength of host ant specificity in the Maculinea–Myrmica association include research on chemical and acoustic mimicry as well as experiments on ant adoption and rearing behaviour of Maculinea larvae. Here we present results of laboratory experiments on adoption, survival, development and integration of M. teleius larvae within the nests of different Myrmica host species, with the objective of quantifying the degree of specialization of this Maculinea species. In the laboratory, a total of 94 nests of four Myrmica species: M. scabrinodis, M. rubra, M.ruginodis and M. rugulosa were used. Nests of M. rubra and M. rugulosa adopted M. teleius larvae more readily and quickly than M. ruginodis colonies. No significant differences were found in the survival rates of M. teleius larvae reared by different ant species. Early larval growth of M. teleius larvae differed slightly among nests of four Myrmica host species. Larvae reared by colonies of M. rugulosa which were the heaviest at the beginning of larval development had the lowest mean larval body mass after 18 weeks compared to those reared by other Myrmica species. None of the M.teleius larvae was carried by M. scabrinodis or M. rubra workers after ant nests were destroyed, which suggests a lack of integration with host colonies. Results indicate that Myrmica species coming from the same site differ in their ability to adopt and rear M. teleius larvae but there was no obvious adaptation of this butterfly species to one of the host ant species. This may explain why, under natural conditions, all four ants can be used as hosts of this butterfly species. Slight advantages of particular Myrmica species as hosts at certain points in butterfly larval development can be explained by the ant species biology and colony structure rather than by specialization of M. teleius

Phosphorus and nitrogen limitation of primary production in a simulated estuarine gradient

The transition between phosphorus limitation of primary production in freshwater and nitrogen limitation in seawater was examined along an estuarine gradient simulated in 4 large 13 m3 enclosures connected in a series and containing pelagic and benthic subsystems. Nominal salinities of 0, 5, 10 and 25 ppt were maintained by exchanging appropriate volumes of water between enclosures. River water, which served as a freshwater endmember, was naturally high in N relative to P, while the oceanic endmember (water from Narragansett Bay, RI, USA) was low in N relative to P. Production in the water column was supported by external inputs and recycled nutrients. Bioassays, inorganic nutrient concentrations and N:P ratios of the seston and inorganic nutrients indicated that phosphorus was limiting at 0, 5 and 10 ppt, while nitrogen was limiting at 25 ppt. Coincident with this shift in limiting nutrient was a shift in the N:P ratio of nutrient supply from greater than the Redfield ratio of 16 to less than 16. External inputs established relative rates of supply in each enclosure. The relative proportion of N and P in external inputs was largely a function of the hydrodynamic mixing of fresh (high N, low P) and salt water (low N, high P) endmembers. At the scale of the estuarine segment or enclosure, neither recycled inputs from the benthos and water column, nitrogen fixation nor internal losses of N and P to sedimentation and/or denitrification materially altered relative supply rates, despite a hydrodynamic residence time of 27 d