Les Diablerets Research Articles

Influence of air flow features on alpine wind energy potential

Wind energy is one of the potential options to fill the gap in renewable energy production in Switzerland during the winter season when the energy demand exceeds local production capacities. With likely further rising energy consumption in the future, the winter energy deficit may further increase. However, a reliable assessment of wind energy potential in complex terrain remains challenging. To obtain such information, numerical simulations are performed using a combination of the “Consortium for Small-scale Modeling” and “Weather Research and Forecasting” (COSMO-WRF) models initialized and driven by COSMO-1E model, which allows us to simulate the influence of topography at a horizontal resolution of 300 m. Two LiDAR measurement campaigns were conducted in the regions of Lukmanier Pass and Les Diablerets, Switzerland. Observational LiDAR data and measurements from nearby wind sensor networks are used to validate the COSMO-WRF simulations. The simulations show an improved representation of wind speed and direction near the ground compared to COSMO-1E. However, with increasing height and less effect of the terrain, COSMO-WRF tends to overestimate the wind speeds, following the bias that is already present in COSMO-1E. We investigate two characteristic mountain–terrain flow features, namely waves and Foehn. The effect of mountain-induced waves of the flow is investigated through an event that occurred in the area of Diablerets. One-year analysis for the frequency of conditions that are favorable for mountain wave formation is estimated. The Foehn impact on wind was observed in the Lukmanier domain. We attempt quantification of the probability of occurrence using the Foehnix model. The result shows a high probability of Foehn occurrence during the winter and early spring seasons. Our study highlights the importance of incorporating complex terrain-related meteorological events into the wind energy assessment. Furthermore, for an accurate assessment of wind speed in complex terrain, our study suggests the necessity to have a better representation of the topography compared to COSMO-1E.

Combining Weather Station Data and Short-Term LiDAR Deployment to Estimate Wind Energy Potential with Machine Learning: A Case Study from the Swiss Alps

Wind energy potential in complex terrain is still poorly understood and difficult to quantify. With Switzerland’s current efforts to shift to renewable energy resources, it is now becoming even more crucial to investigate the hidden potential of wind energy. However, the country’s topography makes the assessment very challenging. We present two measurement campaigns at Lukmanier and Les Diablerets, as representative areas of the complex terrain of the Swiss Alps. A general understanding of local wind flow characteristics is achieved by comparing wind speed measurements from a near-surface ultra-sonic anemometer and from light detection and ranging (LiDAR) measurements further aloft. The measurements show how the terrain modifies synoptic wind for example through katabatic flows and effects of local topography. We use an artificial neural network (ANN) to combine the data from the measurement campaign with wind speed measured by weather stations in the surrounding area of the study sites. The ANN approach is validated against a set of LiDAR measurements which were not used for model calibration and also against wind speed measurements from a 25-meter mast, previously installed at Lukmanier. The statistics of the ANN output obtained from multi-year time series of nearby weather stations match accurately the ones of the mast data. However, for the rather short validation periods from the LiDAR, the ANN has difficulties in predicting lowest wind speeds at both sites, and highest wind speeds at Les Diablerets.

Swiss Summer School on Chemical Biology, Les Diablerets, September 11-15, 2022

Swiss Summer School on Chemical Biology, Les Diablerets, September 11-15, 2022

EFFECTS OF SLOW DEEP BREATHING ON SHORT-TERM CHANGES IN BLOOD PRESSURE, HEART RATE AND O2 SATURATION AT ALTITUDE

Objective: Slow controlled breathing has been reported to reduce blood pressure (BP) in hypertensive patients, decreasing sympathetic nerve activity. In hypoxic conditions associated with high altitude, slow deep breathing has also been shown to improve oxygen saturation and to influence BP and heart rate. In the present teaching experiment conducted during the ESH 2018 Summer School, we have evaluated the impact of slow breathing on hemodynamic parameters and O2 saturation when acutely ascending from les Diablerets (altitude 1150 m) to Glacier 3000 (at 3010 m). Design and method: Blood pressure(ABPM, Novacor System, oscillometric validated device), heart rate and O2 saturation were measured at baseline, 30 minutes after arriving at 3010 m, during slow breathing, after 2 hours at altitude and after returning to baseline. Results: Eleven subjects (4 males/7 females) participated in the experiment. Mean age was 34.3 y and mean BMI was 24.3 km/m2. At baseline, systolic (S) BP and diastolic (D) BP were 132 ± 19/86 ± 11 mmHg, heart rate (HR) was 72.5 ± 8 b/min and O2 saturation was 98.2%. Breathing rate was 13.6 per min. Upon arrival at 3000m, O2 saturation decreased to 91.7% (p < 0.01) and breathing rate increased to 16.5 per min. Both SBP and DBP decreased significantly to 123 ± 14 and 78 ± 9 mmHg respectively (P < 0.01) due to the acute vasodilating effects of hypoxemia. Heart rate increased to 94.8 b/min (p < 0.001). Slow breathing to 6 per min, lowered SBP to 118.8 ± 14 and increased DBP 80.9 ± 8.8 mmHg (p = ns). O2 saturation increased slightly to 92.5%. After 2 h, the subjects adapted their oxygenation but heart rate remained elevated (94.5 b/min). When returned to baseline, all values were normalized. Conclusions: Even short terms changes in altitude induce significant changes in BP, heart rate and O2 saturation in healthy subjects. Slow breathing tends to improve BP and O2 saturation

A global view of Hsp90 functions

The Sixth International Conference on Hsp90 in 2012 revealed new functions of this key molecular chaperone. Attendees of the meeting at Les Diablerets, Switzerland, addressed new discoveries about Hsp90 and its cochaperones.

Finite element modelling of bridging micro-mechanics in through-thickness reinforced composite laminates

Delamination and debonding are the major failure modes in laminated composites, which significantly reduce the performance of a structure under compressive or bending loads. To overcome this problem, new composites with through-thickness reinforcement (TTR) have been used to improve the interlaminar strength and damage tolerance of laminated composites [Freitas G, Fusco T, Campbell T, Harris J, Rosenberg S. Z-fiber TM technology and products for enhancing composite design. In: 83rd Meeting of AGARD SMP, 1996, CP-590; Farley GL, Dickinson LC. Mechanical response of composite materials with through-the-thickness reinforcement. NASA CR-14753, 1993. p. 123–43; Cartié DDR, Partridge IK. Delamination behaviour of Z-pinned laminates In: Williams JG, Pavan A. editors, Proceedings of second ESIS TC4 conference, Les Diablerets, Switzerland, 13–15 September 1999, ESIS Publication, 2000. ISBN 008 043710-9; Greenhalgh E, Hiley M. The assessment of novel materials and processes for the impact tolerant design of stiffened composite aerospace structures. Comp Part A: Appl Sci Manuf 2003;34(2):151–61. [1–4]]. Although the TTR can change the structural elastic response of a composite laminate [Stringer LG, Hiley MJ. Through-thickness reinforcement of composites: Z-pinning, Stitching, and 3D weaving. In: 14th International conference for composite materials, ICCM14, 11–14 July, San Diego, CA, 2003; Mouritz AP, Leong KH, Herszberg I. A review of the effect of stitching on the in-plane mechanical properties of fibre-reinforced polymer composites. Composites Part A 1999;28A:979–91; Grassi M, Zhang X, Meo M. Prediction of stiffness and stresses in z-fibre reinforced composite laminates. Comp Part A: Appl Sci Manuf 2002;33(12):1653–64; Patridge IK, Cartié DDR, Troulis M, grassi, M, Zhang X. Evaluating the mechanical effectiveness of Z-pinning. In: Proceedings of SAMPE/Dayton technical conference, 2003. [5–8]] they start working only when delamination propagates in their field, which provides non-linear bridging closure forces that shield the delamination crack from the full delaminating force and moment of the applied loads [Grassi M, Zhang X. Finite element analyses of mode I interlaminar delamination in z-fibre reinforced composite laminates. Comp Sci Technol 2003;63(12):1815–32; Robinson P, Das S. Mode I DCB testing of composite laminates reinforced with z-direction pins: a simple model for the investigation of data reduction strategies. Eng Fract Mech 2004;71(3):345–64. [9,10]]. Fiber pull-out test has been developed in order to study the micro-mechanics of the TTR bridging a crack under Mode I loading conditions [Cartié DDR, Cox BN, Fleck NA. Mechanisms of crack bridging by composite and metallic rods. Comp Part A: Appl Sci Manuf 2004;35(11):1325–36. [11]], and several analytical models have been developed to analyze these phenomena [Cox B. A constitutive model for through-thickness reinforcement bridging a delamination crack. Adv Comp Lett 1999;8(5):249–56; Jain LK, Mai YW. On the effect of the stitching on Mode I delamination toughness of laminated composites. Comp Sci Technol 1994;51:331–45; Allegri G, Xiang Z. Private communications, 2004. [12–14]]. In terms of energy the TTR fiber pull-out can be accompanied by significant amount of energy dissipation due to the frictional work at interface; this process absorbs part of the energy that would otherwise be placed at the delamination front of the structure. The basic objective of this research project was to develop an efficient and accurate finite-element-based numerical tool to simulate the spontaneous propagation of a single TTR pull-out under quasi-static conditions and in the presence of frictional contact between the fiber/matrix interface. The pull-out phenomenon was studied assuming a constant friction coefficient at the interface along the TTR axial direction and using improved contact-elements to solve the frictional contact problem. Load/displacement bridging curves of the fiber pull-out process, which includes elastic deformation with a fully/partially bonded interface plus frictional sliding, were calculated. Moreover, the effect of friction model was also investigated. Numerical results were validated by experimental observations of debonding and frictional sliding of a fiber in steady-state pull-out tests under pure Mode I loading conditions.

Special issue in honour of Prof. Marc Ilegems

Special issue in honour of Prof. Marc Ilegems

Some more considerations on the optimization of cermet solid oxide fuel cell electrodes

Limiting behaviour and optimization considerations are discussed on the basis of an analytical model (Costamagna, Costa and Antonucci, Electrochim. Acta, 43, 375 (1997); Costamagna, Antonucci, Costa and Arato, Proc. IEA Workshop, Les Diablerets, Switzerland, January 1997, p. 196) for cermet solid oxide fuel cell electrodes. The results show that it is not possible to optimize the overall electrode conductivity, taking polarization and ohmic effects into account (Costamagna, Costa and Antonucci, Electrochim. Acta, 43, 375 (1997)), and the electrode utilization at the same time. Under conditions of optimal conductivity, the electrochemical reaction is unevenly distributed and only a fraction of the electrode thickness effectively supplies electrical current; on the contrary, thicknesses small enough for a uniform current distribution to result are sub-optimal from the point of view of the electrode conductivity.

International Symposium on Metal Hydrogen Systems, Fundamentals and Applications, Les Diablerets, Switzerland, 25–30 August 1996

International Symposium on Metal Hydrogen Systems, Fundamentals and Applications, Les Diablerets, Switzerland, 25–30 August 1996

Winter Workshop on Schizophrenia, Les Diablerets, Switzerland, January 1994

Winter Workshop on Schizophrenia, Les Diablerets, Switzerland, January 1994

Complement in human diseases: looking towards the 21st century

The complement system has evolved to fulfil crucial functions, including opsonization of micro-organisms, enhancement of inflammatory responses, clearance of immune complexes and cell lysis. Deficiencies or dysregulations of this system are associated with major health burdens, such as infectious and autoimmune diseases. A recent meeting * * The Vth European meeting on Complement in Human Disease was held in Les Diablerets, Switzerland, on 9–12 September 1994. addressed the function and role of complement, and its regulators, in human disease.

Integral Workshop on the Multiwavelength Approach to Gamma-Ray Astronomy - Les-Diablerets Switzerland 1993FEB2-5

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The INTEGRAL Workshop on the Multiwavelength Approach to Gamma-Ray Astronomy, Les Diablerets, Switzerland, Feb. 2-5, 1993 Durouchoux, P. ; Courvoisier, T. Abstract The aim of the workshop was to integrate the present results of gamma-ray astronomy with those of other branches of astronomy and to demonstrate the benefits of combining the next-generation gamma-ray results with those to be obtained in other spectral domains. In addition, the workshop investigated the impact of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) mission on the development of gamma-ray astronomy in the early years of the next century. Specific papers addressed the objectives of the INTEGRAL mission, its instrumentation, and some ongoing efforts toward developing more efficient gamma-ray instrumentation. Other papers addressed observational and theoretical aspects of various Galactic sources, extragalactic sources and active galactic nuclei, and gamma-ray bursts. For individual titles, see A95-63096 through A95-63166. Publication: The Astrophysical Journal Supplement Series Pub Date: June 1994 DOI: 10.1086/191972 Bibcode: 1994ApJS...92..325D Keywords: Astronomical Satellites; Conferences; Gamma Ray Astronomy; Spaceborne Astronomy; Active Galactic Nuclei; Background Radiation; Black Holes (Astronomy); Galactic Radiation; Gamma Ray Bursts; Gamma Ray Telescopes; Positron Annihilation; Satellite-Borne Instruments; X Ray Binaries; Astronomy full text sources ADS |

Annual Meeting of the Club Francais de Nephrologie Pediatrique January 22?24, 1987 Les Diablerets, Switzerland

Annual Meeting of the Club Francais de Nephrologie Pediatrique January 22?24, 1987 Les Diablerets, Switzerland

STIP Symposium on Retrospective Analyses and Future Coordinated Intervals

The STIP (Study of Travelling Interplanetary Phenomena) Project of the Scientific Committee for Solar‐Terrestrial Physics held its fifth international meeting in Les Diablerets, Switzerland, June 10–12, 1985. The STIP Project has as its objective the interdisciplinary, informal, and internationally cooperative study of specific solar and interplanetary events during all parts of the solar cycle. The purpose of this meeting was to bring together scientists from all areas of solar‐terrestrial physics, both theoretical and experimental, to promote this coordinated study of coupling between the sun and the heliosphere and, in particular, to focus attention on 14 specific intervals of study and to outline scientific objectives for five future intervals. The meeting consisted of six successive sessions and an open business meeting. The program was arranged so that previously appointed coordinators could present invited half‐hour summaries of the scientific highlights that characterized each of their Intervals. Contributed papers of 20‐minute duration were interspersed among the chronological Interval presentations with 10–20 minute informal discussions following the speakers' presentations. There were 42 scientific papers presented at the meeting by 45 participants from 13 countries. The cosponsors of the conference, along with the Scientific Committee on Solar‐Terrestrial Physics, were Committee for Space Research, International Astronomical Union, and International Union of Pure and Applied Physics. The papers presented at the Les Diablerets meeting will appear in STIP Symposium on Retrospective Analyses (M. A. Shea and D. F. Smart, Editors), a publication by the STIP Project, which is to be available in late 1986.

Review of: “ Space Laser Applications and Technology (SPLAT).” Compiled by B. BATTRICK and E. ROLFE. (Noordwijk, The Netherlands: ESTEC, ESA SP-202, Proceedings of an ESA workshop at Les Diablerets, Switzerland on 25-30 March 1984,) [Pp. 272.] Price Ff 170.

"Review of: “ Space Laser Applications and Technology (SPLAT).” Compiled by B. BATTRICK and E. ROLFE. (Noordwijk, The Netherlands: ESTEC, ESA SP-202, Proceedings of an ESA workshop at Les Diablerets, Switzerland on 25-30 March 1984,) [Pp. 272.] Price Ff 170.." International Journal of Remote Sensing, 6(8), p. 1463

Education in prosthetics and orthotics/1

At the time of the first World Congress of ISFO a “workshop” was held in Les Diablerets, Switzerland, to attempt to identify needs and establish priorities of action in prosthetics and orthotics throughout the world (ISFO, 1975). In response to questionnaires sent out six months prior to this event, 33 countries, representing nearly half of the world population, provided information on patient population, facilities, professional staff, etc. While there were gaps in the information obtained and although many of the statistics provided were clearly suspect, it was possible to get an impression of the extent of the problem. In the disability types considered, the number of physically handicapped was reported as being over 14,000,000 in a total population of about 1,200,000,000. This suggests that about one person in 100 might require some type of appliance. It appeared that only 1,800,000 have been provided with devices, leaving over 12,000,000 handicapped individuals for whom no appliance had been made. It was estimated that about 11 prosthetists, orthotists and technicians were needed to care for 1,000 patients. Thus, to provide service for the 12,000,000 handicapped presently uncatered for would require the training of 132,000 persons.