Phd - Postdoc Scholarship, Beasiswa S3 Israel & Perancis

Israel - Technion - Israel Institute of Technology Postdoc Position in Spatial and / or Temporal Growth of Water Waves


Post-doctoral Scholarship sponsored by

Technion-Israel Institute of Technology
Department of Civil and Environmental Engineering

Title: Spatial and/or temporal growth of water waves in a wind-wave flume

Prof. Michael Stiassnie is seeking a suitable qualified researcher to undertake Post-Doctoral study to develop a theoretical model for the growth of water waves in a wind-wave flume, under his supervision.

About Technion:
For more than eight decades, the Technion-Israel Institute of Technology, which is located in Haifa, has been Israel’s primary technological university and the largest center of applied research. It is ranked among the leading technological universities in the world. The Department of Civil and Environmental Engineering has 60 senior faculty members active in research and education, and they currently supervise the education of ~900 undergraduate students, ~240 master degree students, ~85 doctor students, and ~10 post-doctoral researchers.

Project Abstract:
The importance of adequate description of interaction of wind with ocean waves cannot be overestimated, both on the global level of earth climate, and on a more local level of the necessity to predict the sea state for practical operation of off-shore and near-shore facilities. The goal of this study is to gain a better understanding of the dominant phenomena that determine the growth of waves under the effect of wind in a laboratory flume. This will enable us to offer better modeling of wind-wave growth rate. To attain this goal, it is crucial to realize that as water waves are affected by wind, the wind velocity profile in the vicinity of air-water interface is strongly affected by the waves.

Detailed measurements of the air and water flow field in a laboratory wind-wave flume and of the spatial and/or temporal evolution of the wave field will be carried out by a partner team, lead by Prof. Lev Shemer at the Tel-Aviv University. The experimental results will be compared with new computations based on the solution of the Orr-Sommerfeld equation for the experimentally determined air and water velocity profiles. Such a comparison will lead to critical assessment of the underlying model assumptions and to introduction of appropriate modifications. It is expected that an iterative experimental-theoretical process will lead to a better understanding of the physics of air-water flow interaction, in particular of the wind-wave growth mechanism, and as a result to a more accurate theoretical description of this process.

Selection Criteria

Ph.D. degree related to fluid-mechanics, obtained not earlier than 31.12.2005 (essential)
Strong analytical and mathematical skills (essential)
A good working knowledge of programming (desirable)
A good knowledge of English (desirable)
Experience in water-waves related research (advantage)
Commencement Date
January 2009 or earlier

Scholarship
U.S. $ 28,000 per annum, tax exempt
Duration: one or two years

Application and Contact
Professor Michael Stiassnie
Department of Civil and Environmental Engineering
Division of Environmental, Water and Agricultural Engineering
Technion-Israel Institute of Technology
Haifa 32000, Israel
Tel: +972-4-8293361 ; Fax: +972-4-8228898
e-mail: miky@tx.technion.ac.il
http://www.technion.ac.il/~cee/stiassnie

=====================================================




France - University of Franche-Comté PhD Scholarship in Spectral Analysis of Phase Noise and Frequency Stability of Oscillators

Ph.D. Training Opportunity & Stipend – starting fall 2008

Spectral analysis of phase noise and frequency stability of oscillators
proposed byEnrico Rubiola

FEMTO-ST Institute, Dept. of Time and Frequency
CNRS et University of Franche Comte

Subject
Time and frequency have a privileged role in physics and applications because they are the most precisely measured physical quantities. The wrist watch, for example, is the only artifact accurate within 1E-5 - 1E-6 at a cost affordable to all consumers. Atomic clocks exhibit the amazing accuracy of 1E-15, and a stability better by a factor 10. Though the accuracy of 1E-15 relates only to fundamental physics and metrology, short term stability is a major concern in telecommunications, space applications and radars.

Traditionally, frequency stability is measured in the time domain and described using wavelet variances known as the Allan variance sigma_y^2(tau) and its modified versions. The variable tau is the measurement time. The stability depends on the measurement time in the same way of a balance, which is less “precise” when the mass to be measured is very different from 1 kg.

The estimation of sigma_y^2(tau) and of its confidence is well documented in the literature available in the past 20 years. Conversely, the spectral analysis of oscillators is still an empirical domain, in which results are usually given as a raw power spectral density of the phase noise, i.e., Sphi(f) ou L (f). Analysis seldom goes beyond the identification of the interference from the mains power supply (50 or 60 Hz et harmonics) and the identification of two-three fundamental types of noise. This approach is no longer suitable to the needs of emerging technologies.

This is a new domain. Hence, the minimum target is reasonably low: to adapt established spectral-analysis methods to the oscillator and to identify the oscillator’s stochastic phenomena. Nonetheless, this is a great opportunity for a smart student, as he can innovate in the interpretation of the oscillator physics and in the measurement methods and achieve outstanding experimental results. A side branch is the improvement of the measurement accuracy, which is currently of 2 dB in primary laboratories. The bulk of the expected work is about the statistical analysis of phase noise spectra. Besides, the student will achieve a deep understanding of oscillators and of experimental techniques.

University and laboratory
Ph.D. scholarship is managed by the University of Franche Comt’e, Besançon, France. The work site is the Time and Frequency Dept. of the FEMTO-ST Institute, affiliated to the University of Franche Comt’e, Besançon. This department, merging the laboratory of chronometry (LCEP) and the laboratory of physic and metrology of oscillators (LPMO), issues from the Laboratoire de l’Horloge Atomique, funded by the Nobel prize Alfred Kastler. The T&F Dept. is the world leader in the domain of the measurement of the oscillator noise. Besides, this department is the european leader in the domain of ultra-stable oscillators and chip-scale atomic clocks.

Candidate profile
The best student for this subject is fond to computer programming and calculus, and eager to learn sophisticated experimental methods of electronics. He is motivated by the will of learning and by the investment on his future life. In the longer term, he would like to do applied research in academic institutions or industry, or high-tech engineering, preferably in international environment.

Advisors
During his Ph.D., the student will be advised by E. Rubiola (2/3-3/4), full professor, and by F. Vernotte (1/4-1/3), full professor and head of the Observatory of Besançon.

Stipend
The student will receive a stipend from the French ministry of education for three years, as ruled by the French government. The candidate must fill two conditions

age 29 years max,
university degree “Master 2″ (5 year university degree) or equivalent, obtained in 2008. The equivalence is managed on site.
Candidates unaware of the French education system should know that: tuition are very small or zero, and the stipend is generally sufficient for a modest yet quite reasonable life standard.

Contact
e-mail: rubiola@femto-st.fr
home page http://rubiola.org