Polarization effects on the effective temperature of an ultracold electron source

The influence has been studied of the ionization laser polarization on the effective temperature of an ultracold electron source, which is based on near-threshold photoionization. This source is capable of producing both high-intensity and high-coherence electron pulses, with applications in for example electron diffraction experiments. For both nanosecond and femtosecond photoionization, a sinusoidal dependence of the temperature on polarization angle has been found. For most experimental conditions, the temperature is minimal when the polarization coincides with the direction of acceleration. However, surprisingly, for nanosecond ionization a regime exists when the temperature is minimal when the polarization is perpendicular to the acceleration direction. This shows that in order to create electron bunches with the highest transverse coherence length, it is important to control the polarization of the ionization laser. The general trends and magnitudes of the temperature measurements are described by a model, based on the analysis of classical electron trajectories; this model further deepens our understanding of the internal mechanisms during the photoionization process. Furthermore, for nanosecond ionization, charge oscillations as a function of laser polarization have been observed; for most situations the oscillation amplitude is small

How do cynical employees serve their customers?: a multi-method study

In this multi-method study, we investigate how social job demands (i.e., social interruptions) and resources (i.e., colleague support) in the service context influence employee (negative) (re)actions to customers through cynicism towards the job. In addition, we investigate why customers are less satisfied with the provided service when employees endorse a cynical attitude. To test the hypothesized process, we used observer ratings of the employee–customer interactions regarding the number of interruptions and employee negative (re)actions during service encounters, employee self-reports of overall colleague support and daily cynicism, and customer-ratings of service quality. Participants were 48 service employees and 141 customers. Results of multi-level structural equation modelling analyses showed that whereas the number of observed social interruptions during service encounters related positively to cynicism, social support related negatively. Cynical employees exhibited more negative (re)actions towards their customers (e.g., expressed tension, were unfriendly). Consequently, the more negative (re)actions employees showed towards their customers, the less satisfied customers were with the service quality. The study contributes to the literature by explaining what makes service employees cynical about their work, and why cynical employees provide low-quality services.</p

An update to the surface ocean CO2 atlas (SOCAT version 2)

22 páginas, 9 figuras, 10 tablas.-- D. C. E. Bakker ... et al.-- This work is distributed under the Creative Commons Attribution 3.0 License.-- Proyecto CarbochangeThe Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO2 (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO2 values) and extended data coverage (from 1968–2007 to 1968–2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon modelsSupport for SOCAT has been received from the University of East Anglia (UK), the Bjerknes Centre for Climate Research, the Geophysical Institute at the University of Bergen (Norway), the Climate Observation Division of the Climate Program Office of the US National Oceanic and Atmospheric Administration, the University of Washington, Oak Ridge National Laboratory (USA), PANGAEA ® Data Publisher for Earth and Environmental Data (Germany), the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Germany), the National Institute for Environmental Studies (Japan), the Korean Institute of Ocean Science and Technology, the European Union projects CarboChange (FP7 264879) and GEO- CARBON (FP7 283080), the UK Ocean Acidification Research Programme (NE/H017046/1; funded by the Natural Environment Research Council, the Department for Energy and Climate Change and the Department for Environment, Food and Rural Affairs), the Research Council of Norway (CARBON-HEAT), the Scientific Committee on Oceanic Research (SCOR, US, OCE-0938349), the US National Science Foundation (OCE-1068958), Swedish Research Council projects (2009–2994; 2008–6228; 2009–2994) and the Swedish National Space Board (RESCUE project; REmote Sensing ocean Carbon UptakE).Peer reviewe

First Meeting of the joint IOC-ICES Study Group on Nutrient Standards (SGONS)

A meeting of the joint IOC-ICES Study Group on Nutrient Standards (SGONS) was held in Paris, France on 23-24 March 2010. It focused on the ongoing activities of the SGONS and plans for extended international collaborations to establish global comparability of the nutrient data from the world’s ocean. Thirty two scientists and experts from 11 countries and 2 delegates from IOC attended the meeting. The discussions followed the Terms of References of SGONS established in July 2009. Development of the reference materials for nutrients in seawater (RMNS) were also discussed in collaboration with the producers. The background and history of SGONS and an international nutrients scale system INSS and the progress with the production of RMNS materials and their current availability were reported. The production of RMNS and the latest status of the RMNS production facility, current status on the certification of RMNS for nitrate, nitrite, phosphate and silicate at the National Metrology Institute of Japan were also reported. The revised nutrients analysis manual which is being undertaken by the SGONS hopefully would be completed by 1 August 2010, and it will be published on line at the Go-Ship website. Results obtained with RMNS solutions used on the P6 reoccupation cruise in 2009-2010 by SIO (Scripps Institute of Oceanography, USA) showed that considerable improvement could be made in the internal comparability of the data by referencing it to the RMNS results and related good comparability with the previous P6 cruise in 2003 by JAMSTEC when RMNS were also used. The meeting strongly endorsed the idea of a ship board workshop in 2013/14 during which major groups would carry out a full inter-comparison of all procedures including analytical methods on board a research ship. The global stability test of RMNS by ten core laboratories of SGONS which started in 2009 will continue for more two years. It also was agreed to set up an international steering committee to plan the next inter-laboratory comparison study which will extend the study to about 70 laboratories working globally on deep sea hydrography. This will happen in early 2011. Future arrangements were considered for the collection of more batches of seawater for the preparation of RMNS waters suitable for use in all major water masses, and a list of candidate cruises in 2010/2011 was prepared. The related point of the extension of the use of RMNS for work in shelf sea water was also discussed, this followed on from discussions at the ICES Marine Chemistry Working Group (MCWG) meeting in 2010. The ICES MCWG considered that the use of suitable RMNS solutions would be valuable for improving the inter comparability of shelf sea data and be a valuable complement to work with the existing QUASIMEME proficiency testing scheme

Cruise report hydro acoustic survey for blue whiting (Micromesistius poutassou) with R.V. Tridens, 17 March - 04 April 2008

This is the report of the Dutch part of the international North East Atlantic hydro acoustic survey for blue whiting. The survey is coordinated by ICES and has been executed annually. The purpose of the survey is to estimate the blue whiting stock of the North East Atlantic. The ICES uses this estimation is as a “tuning index” to assess the North East Atlantic blue whiting stock. The applied method was echo integration. By sailing transects over the survey area, the total acoustic cross-section can be calculated by surface area sampled. Trawling identified species composition of localized schools. The length composition of each species was determined. Blue whiting was examined on age and fecundity from which a split up stock structure was mad

Tracer Measurements in Growing Sea Ice Support Convective Gravity Drainage Parameterizations

Gravity drainage is the dominant process redistributing solutes in growing sea ice. Modeling gravity drainage is therefore necessary to predict physical and biogeochemical variables in sea ice. We evaluate seven gravity drainage parameterizations, spanning the range of approaches in the literature, using tracer measurements in a sea ice growth experiment. Artificial sea ice is grown to around 17 cm thickness in a new experimental facility, the Roland von Glasow air‐sea‐ice chamber. We use NaCl (present in the water initially) and rhodamine (injected into the water after 10 cm of sea ice growth) as independent tracers of brine dynamics. We measure vertical profiles of bulk salinity in situ, as well as bulk salinity and rhodamine in discrete samples taken at the end of the experiment. Convective parameterizations that diagnose gravity drainage using Rayleigh numbers outperform a simpler convective parameterization and diffusive parameterizations when compared to observations. This study is the first to numerically model solutes decoupled from salinity using convective gravity drainage parameterizations. Our results show that (1) convective, Rayleigh number‐based parameterizations are our most accurate and precise tool for predicting sea ice bulk salinity; and (2) these parameterizations can be generalized to brine dynamics parameterizations, and hence can predict the dynamics of any solute in growing sea ic

Infrared High-Resolution Spectroscopy of Post-AGB Circumstellar Disks. I. HR 4049 - The Winnowing Flow Observed?

High-resolution infrared spectroscopy in the 2.3-4.6 micron region is reported for the peculiar A supergiant, single-lined spectroscopic binary HR 4049. Lines from the CO fundamental and first overtone, OH fundamental, and several H2O vibration-rotation transitions have been observed in the near-infrared spectrum. The spectrum of HR 4049 appears principally in emission through the 3 and 4.6 micron region and in absorption in the 2 micron region. The 4.6 micron spectrum shows a rich 'forest' of emission lines. All the spectral lines observed in the 2.3-4.6 micron spectrum are shown to be circumbinary in origin. The presence of OH and H2O lines confirm the oxygen-rich nature of the circumbinary gas which is in contrast to the previously detected carbon-rich material. The emission and absorption line profiles show that the circumbinary gas is located in a thin, rotating layer near the dust disk. The properties of the dust and gas circumbinary disk and the spectroscopic orbit yield masses for the individual stars, M_AI~0.58 Msolar and M_MV~0.34 Msolar. Gas in the disk also has an outward flow with a velocity of $\gtrsim$ 1 km/s. The severe depletion of refractory elements but near-solar abundances of volatile elements observed in HR 4049 results from abundance winnowing. The separation of the volatiles from the grains in the disk and the subsequent accretion by the star are discussed. Contrary to prior reports, the HR 4049 carbon and oxygen isotopic abundances are typical AGB values: 12C/13C=6^{+9}_{-4} and 16O/17O>200.Comment: 42 pages, 14 figures, Accepted by Ap