Investigating the influence of surfactants on the stabilization of aqueous reduced graphene oxide dispersions and the characteristics of their composite films

The stabilization of reduced graphene oxide (RGO) sheets in aqueous dispersion using a wide range of surfactants of anionic, non-ionic and zwitterionic type has been investigated and compared under different conditions of pH, surfactant and RGO concentration, or sheet size. The observed differences in the performance of the surfactants were rationalized on the basis of their chemical structure (e.g., alkylic vs. aromatic hydrophobic tail or sulfonic vs. carboxylic polar head), thus providing a reference framework in the selection of appropriate surfactants for the processing of RGO suspensions towards particular purposes. RGO-surfactant composite paper-like films were also prepared through vacuum filtration of the corresponding mixed dispersions and their main characteristics were investigated. The composite paper-like films were also electrochemically characterized. Those prepared with two specific surfactants exhibited a high capacitance in relation to their surfactant-free counterpart.

Mapas de actividades comunitarias y activos para la salud: ¿Cómo trabajar con ellos?

El modelo de activos para la salud tiene relaciones íntimas con el paradigma de la Promoción de la Salud, de modelos de Desarrollo Comunitario o de la Teoría Salutogénica de Antonovsky, siendo su punto de partida la Salud Positiva de una comunidad y de las personas que la integran.

La naturalización de refugiados burundeses en Tanzania

La oferta de ciudadanía por parte de Tanzania a unos 200.000 refugiados recibió atención y apoyo internacionales. El hecho de reconocer los puntos fuertes y los defectos de este modelo podría potencialmente ayudar a desbloquear otras situaciones de desplazamiento prolongado alrededor del mundo.

The European Commission and International Trade Negotiations: A Principal-Agent Approach. IES WORKING PAPER 2/2011

Starting from the concept of delegation of power in external trade policy, this paper aims to investigate the dynamics surrounding the European Union’s position in international trade negotiations. The analysis centres on the role of the European Commission (the agent), which by means of Treaty-based delegation and as mandated by the Council (the principal) acts as the sole trade negotiator in the international sphere on behalf of the European Union (EU). The broader negotiating process is thus conceptualised as a threelevel game, where the Commission holds an intermediary position between the European and international levels and also interacts with the Member States in the Council. After an insight into the European decision-making process for external trade, the paper further analyses the Commission’s role during the multilateral trade negotiations of the Doha Development Round. By applying the principal-agent theory to international trade negotiations in general, and subsequently to the controversial agricultural negotiations, this paper seeks to investigate some of the potential sources of autonomy that the Commission can draw upon while upholding an EU position at the international level, in addition to the “hardball” job of balancing the interests of the Member States with those of World Trade Organisation (WTO) partners. Along these lines, the paper finally aims to contribute to the literature concerning agency autonomy in EU external trade relations but also to provide a better understanding of inter-institutional relations within the EU as they may unfold in practice.

(Table 1) Stable carbon and oxygen isotope ratios of benthic foraminifera of ODP Hole 184-1148A

Changes in intermediate and deep ocean circulation likely played a significant role in global carbon cycling and meridional heat/moisture transport during the middle Miocene climate transition (~14 Ma). High-resolution middle Miocene (16-13 Ma) benthic foraminifer stable isotope records from the South China Sea reveal a reorganization of regional bottom waters, which preceded the globally recognized middle Miocene ~1 per mil d18O increase (13.8 Ma) by 100,000 years. An observed reversal of the benthic foraminifera d13C gradient between ODP Sites 1146 (2092 m) and 1148 (3294 m; 13.9-13.5 Ma) is interpreted to reflect an increase in the southward flux of low d13C deep (> 2000 m) Pacific Ocean waters (Flower and Kennett, 1993, doi:10.1029/93PA02196; Shevenell and Kennett, 2004). Large-scale changes in Pacific intermediate and deep ocean circulation, coupled with enhanced global carbon cycling at the end of the Monterey Carbon Isotope excursion, likely acted as internal feedbacks to the Earth's climate system. These feedbacks reduced the sensitivity of Antarctica to lower latitude-derived heat/moisture and facilitated the transition of the Earth's climate system to a new, relatively stable glacial state.

Haroldo; episodio del siglo XV, tomado del francés

A poem.

Portrait of Emma A. Hall

On verso: Brasiers Photo. and Fine Art Gallery, Brooklyn, NY

Union through the ages.

"Signed copy. Number 246. [This copy not signed]"

12 cançons populars catalanes /

The last page contains only blank staves.

Museo histórico Sarmiento ...

"Sarmiento; sintesis cronológica de su vida, recopilación de la sta. Amelia Pico" : 6 p. at end.

Safety study : risk factors associated with weather-related general aviation accidents /

The goal of this National Transportation Safety Board study was to better understand the risk factors associated with accidents that occur in weather conditions characterized by IMC or poor visibility ("weather-related accidents"). The study accomplished this goal using the case control methodology, which compared a group of accident flights to a matching group of nonaccident flights to identify patterns of variables that distinguished the two groups from each other. This methodology expands on previous Safety Board efforts that have typically concentrated on summaries of accident cases. For this study, Safety Board air safety investigators (ASI) collected data from 72 GA accidents that occurred between August 2003 and April 2004.

Aircraft accident report : crash during approach to landing, Circuit City Stores, Inc., Cessna Citation 560, N500AT, Pueblo, Colorado, February 16, 2005 /

On February 16, 2005, about 0913 mountain standard time, a Cessna Citation 560, N500AT, operated by Martinair, Inc., for Circuit City Stores, Inc., crashed about 4 nautical miles east of Pueblo Memorial Airport, Pueblo, Colorado, while on an instrument landing system approach to runway 26R. The two pilots and six passengers on board were killed, and the airplane was destroyed by impact forces and postcrash fire. The flight was operating under the provisions of 14 Code of Federal Regulations Part 91 on an instrument flight rules flight plan. Instrument meteorological conditions prevailed at the time of the accident. The National Transportation Safety Board determines that the probable cause of this accident was the flight crew's failure to effectively monitor and maintain airspeed and comply with procedures for deice boot activation on the approach, which caused an aerodynamic stall from which they did not recover. Contributing to the accident was the Federal Aviation Administration's failure to establish adequate certification requirements for flight into icing conditions, which led to the inadequate stall warning margin provided by the airplane's stall warning system.

Hernán-Cortés (estudio de un carácter)

"Capitanes, oficiales y soldados que fueron con Cortés á México" p.[157]-174.

The charity visitor; a handbook for beginners,

Mode of access: Internet.