Lavayssiere M.,CEA Grenoble |
Escher M.,FOCUS GmbH |
Renault O.,CEA Grenoble |
Mariolle D.,CEA Grenoble |
Barrett N.,CEA Saclay Nuclear Research Center
Journal of Electron Spectroscopy and Related Phenomena | Year: 2013
Photoelectron emission microscopy (PEEM) is a powerful non-destructive tool for spatially resolved, spectroscopic analysis of surfaces with sub-micron chemical heterogeneities. However, in the case of micron scale patterned semiconductors, band line-ups at pn junctions have a built-in lateral electric field which can significantly alter the PEEM image of the structure with respect to its physical dimensions. Furthermore, real surfaces may also have physical topography which can reinforce or counteract the electrically induced distortion at a pn junction. We have measured the experimental PEEM image distortion at such a junction and carried out numerical simulations of the PEEM images. The simulations include energy filtering and the use of a contrast aperture in the back focal plane in order to describe the changes in the PEEM image of the junction with respect to its real physical dimensions. Threshold imaging does not give a reliable measurement of micron sized p and n type patterns. At higher take-off energies, for example using Si 2p electrons, the pattern width is closer to the real physical size. Physical topography must also be quantitatively accounted for. The results can be generalized to PEEM imaging of any structure with a built-in lateral electric field. © 2013 Elsevier B.V. All rights reserved.
Escher M.,FOCUS GmbH |
Winkler K.,Omicron Nanotechnology GmbH |
Renault O.,CEA Grenoble |
Barrett N.,French Atomic Energy Commission
Journal of Electron Spectroscopy and Related Phenomena | Year: 2010
The design and applications of an instrument for imaging X-ray photoelectron spectroscopy (XPS) are reviewed. The instrument is based on a photoelectron microscope and a double hemispherical analyser whose symmetric configuration avoids the spherical aberration (α2-term) inherent for standard analysers. The analyser allows high transmission imaging without sacrificing the lateral and energy resolution of the instrument. The importance of high transmission, especially for highest resolution imaging XPS with monochromated laboratory X-ray sources, is outlined and the close interrelation of energy resolution, lateral resolution and analyser transmission is illustrated. Chemical imaging applications using a monochromatic laboratory Al Kα-source are shown, with a lateral resolution of 610 nm. Examples of measurements made using synchrotron and laboratory ultra-violet light show the broad field of applications from imaging of core level electrons with chemical shift identification, high resolution threshold photoelectron emission microscopy (PEEM), work function imaging and band structure imaging. © 2009 Elsevier B.V. All rights reserved.
Escher M.,FOCUS GmbH |
Weber N.B.,FOCUS GmbH |
Merkel M.,FOCUS GmbH |
Plucinski L.,Jülich Research Center |
Schneider C.M.,Jülich Research Center
e-Journal of Surface Science and Nanotechnology | Year: 2011
To overcome the restrictions of conventional spin detectors (Mott, SPLEED) low energy electron scattering at a Fe(100)-p(1×1)O surface was first proposed by Bertacco and Ciccacci [Phys. Rev. B 59, 4207 (1999)] as a system for highly efficient spin detection. We developed a new instrument based on that scheme. The iron is prepared in-situ on a W(100) crystal without the need for separate sample preparation and exchange when using a MgO substrate. Our working point at 6.5 eV scattering energy is consistent with the above paper by Bertacco and Ciccacci. Results obtained with UPS on an Fe film are shown. With a Sherman-function of approx. 30% and a reflectivity of up to 10% the figure of merit (FOM) is more than one magnitude higher compared to conventional detectors. The FOM shows no degradation over days in UHV. © 2011 The Surface Science Society of Japan.
Wiemann C.,Jülich Research Center |
Patt M.,Jülich Research Center |
Cramm S.,Jülich Research Center |
Escher M.,FOCUS GmbH |
And 6 more authors.
Applied Physics Letters | Year: 2012
We report about a proof-of-principle experiment which explores the perspectives of performing hard x-ray photoemission spectromicroscopy with high lateral resolution. Our results obtained with an energy-filtered photoemission microscope at the PETRA III storage ring facility using hard x-ray excitation up to 6.5 keV photon energy demonstrate that it is possible to obtain selected-area x-ray photoemission spectra from regions less than 500 nm in diameter. © 2012 American Institute of Physics.
Rubio-Zuazo J.,European Synchrotron Radiation Facility |
Rubio-Zuazo J.,CSIC - Institute of Materials Science |
Escher M.,FOCUS GmbH |
Merkel M.,FOCUS GmbH |
And 2 more authors.
Review of Scientific Instruments | Year: 2010
We have developed an energy analyzer, High Voltage-Cylinder Sector Analyzer 300/15, for electron kinetic energies up to 15 keV. It is especially suited for hard x-ray photoelectron spectroscopy, but also for ultraviolet and soft x-ray photoelectron spectroscopy (ultraviolet photoemission spectroscopy, x-ray photoemission spectroscopy), Auger electron spectroscopy, and reflection high energy electron spectroscopy. The analyzer is based on a cylinder sector with 90° deflection, 300 mm slit-to-slit distance, and a four-element pre-retarding lens system with 50 mm sample-to-lens distance. The result is a very compact design of the analyzer that is easily integrated into a multipurpose experiment with different techniques. A low noise/low drift electronics is capable of continuous energy scans from 0 to 15 keV using nonlinear lens curves. The first analyzer is allocated at the Spanish CRG SpLine beamline at the ESRF at an end station where simultaneous surface x-ray diffraction is possible. The analyzer is operated routinely since 2006 up to 15 keV electron kinetic energy, expanding the achievable electron kinetic energy range compared to other commercial analyzers. In this work we present a detailed description of the developed electron analyzer. The analyzer capabilities, in terms of energy resolution and transmission, are shown by using an electron gun, an ultraviolet-discharge lamp, and hard x-ray synchrotron radiation as excitation sources. © 2010 American Institute of Physics.
Szeimies R.-M.,University of Regensburg |
Reich K.,Dermatologikum Hamburg |
Pabst G.,FOCUS GmbH |
Voss D.,FOCUS GmbH |
And 4 more authors.
British Journal of Dermatology | Year: 2010
Background Photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA) provides a therapeutic option for the treatment of actinic keratosis (AK). Different strategies are applied to overcome the chemical instability of ALA in solution and to improve skin penetration. A new stable nanoemulsion-based ALA formulation, BF-200 ALA, is currently in clinical development for PDT of AK. Objectives To evaluate the efficacy and safety of PDT of AK with BF-200 ALA. Methods The study was performed as a randomized, multicentre, double-blind, placebo-controlled, interindividual, two-armed trial with BF-200 ALA and placebo. A total of 122 patients with four to eight mild to moderate AK lesions on the face and/or the bald scalp were included in eight German study centres. The efficacy of BF-200 ALA after one and two PDT treatments was evaluated. BF-200 ALA was used in combination with two different light sources under illumination conditions defined by European competent authorities. Results PDT with BF-200 ALA was superior to placebo PDT with respect to patient complete clearance rate (per-protocol group: 64% vs. 11%; P < 0·0001) and lesion complete clearance rate (per-protocol group: 81% vs. 22%) after the last PDT treatment. Statistically significant differences in the patient and lesion complete clearance rates and adverse effect profiles were observed for the two light sources, Aktilite® CL128 and PhotoDyn® 750, at both time points of assessment. The patient and lesion complete clearance rates after illumination with the Aktilite® CL128 were 96% and 99%, respectively. Conclusions BF-200 ALA is a very effective new formulation for the treatment of AK with PDT. Marked differences between the efficacies and adverse effects were observed for the different light sources used. Thus, PDT efficacy is dependent both on the drug and on the characteristics of the light source and the illumination conditions used. © 2010 British Association of Dermatologists.
Jansen C.,Royal Tropical institute |
Codjia L.,World Health Organization |
Cometto G.,World Health Organization |
Yansane M.L.,FOCUS GmbH |
Dieleman M.,Royal Tropical institute
Risk Management and Healthcare Policy | Year: 2014
Background: Universal health coverage requires a health workforce that is available, accessible, and well-performing. This article presents a critical analysis of the health workforce needs for the delivery of maternal and neonatal health services in Guinea, and of feasible and relevant interventions to improve the availability, accessibility, and performance of the health workforce in the country. Methods: A needs-based approach was used to project human resources for health (HRH) requirements. This was combined with modeling of future health sector demand and supply. A baseline scenario with disaggregated need and supply data for the targeted health professionals per region and setting (urban or rural) informed the identification of challenges related to the availability and distribution of the workforce between 2014 and 2024. Subsequently, the health labor market framework was used to identify interventions to improve the availability and distribution of the health workforce. These interventions were included in the supply side modeling, in order to create a “policy rich” scenario B which allowed for analysis of their potential impact. Results: In the Republic of Guinea, only 44% of the nurses and 18% of the midwives required for maternal and neonatal health services are currently available. If Guinea continues on its current path without scaling up recruitment efforts, the total stock of HRH employed by the public sector will decline by 15% between 2014 and 2024, while HRH needs will grow by 22% due to demographic trends. The high density of HRH in urban areas and the high number of auxiliary nurses who are currently employed pose an opportunity for improving the availability, accessibility, and performance of the health workforce for maternal and neonatal health in Guinea, especially in rural areas. Conclusion: Guinea will need to scale up its recruitment efforts in order to improve health workforce availability. Targeted labor market interventions need to be planned and executed over several decades to correct entrenched distortions and mismatches between workforce need, supply, and demand. The case of Guinea illustrates how to design and operationalize HRH interventions based on workforce projections to accompany and facilitate universal health coverage reforms. © 2014 Jansen et al.
Otten C.,FOCUS GmbH |
Reisgen U.,RWTH Aachen |
Schmachtenberg M.,RWTH Aachen
Welding in the World | Year: 2016
The electrification of the traffic sector increases the importance of the joining of aluminum with copper. During the fusion welding of this joint, brittle intermetallic phases which exert a great influence on the load-bearing capability are developing. Until today, systematic investigations of the different, developing phases neither have been carried out nor has a direct correlation with the mechanical properties been made. Within the scope of this paper, electron beam welding on Al-Cu plates is examined. The focus is put on the identification of the different phases and on their influence on the tensile strength. To this end, the mixture ratio and the energy-per-unit length are varied within the framework of test series. As a result, the microstructure of the welded joint can be characterized via electron backscatter diffraction (EBSD) tests. Further, a direct correlation of these tests with the failure of the welded joint will be made. The greatest weld joint strength of 104 MPa was achieved when the microstructure of the joint featured a lamellar structure, whereas formation of the Al2Cu phase resulted in brittle fracture of the welded joints along the Al2Cu/lamellar matrix interfaces. © 2015, International Institute of Welding.
Bretschneider R.A.,FOCUS GmbH
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015
Over the past few years the interest in period tracking apps increased, which represent a sub-genre of quantified self apps in women health. They are available in a variety of complexity levels ranging from simple menstruation diaries up to applications with complex fertility calculation algorithms. The goal of this paper is to propose an approach for a period tracking app with an adaptive user interface that takes the users goal and context into account. Our research focusses on the motivations to use a period tracker, the questions that users have regarding their cycle data and how a quantified self app could help in answering these questions. © Springer International Publishing Switzerland 2015.
FOCUS GmbH | Date: 2011-01-25
Printed matter all in the field of television broadcasting and television entertainment, namely, leaflets, periodicals, newspapers, books, posters, stickers, calendars, photographs, stationery, printed instructional and teaching material pertaining to the field of television broadcasting and television entertainment. Telecommunication services for others in the field of television broadcasting and television entertainment, namely, transmission of information via wireless networks, cable networks, and radio and television broadcasting; on-line-services for others in the field of television broadcasting and television entertainment, namely, transmission of news, e-mail-data-services, and providing internet services. Providing services for others in the field of television broadcasting and television entertainment, namely, gathering and disseminating of news and publishing printed matter, in particular newspapers, periodicals and books, and teaching and instructional material, including sound and image information maintained and accessible in electronic format via intranets and the internet, and publications on the Internet including electronic books and periodicals; providing services of a television studio, namely, production of sound and image recordings on sound and image carriers; rental of sound and image recordings in the field of television broadcasting and television entertainment; production of TV and radio entertainment programs and programming; conducting entertainment events in the fields of education, sports, music, arts, culture and humanities via television broadcasting and television entertainment, providing entertainment services for other in the form of live-events in the fields education, sports, music, arts, culture and humanities via television broadcasting and television entertainment.