Last Modifiied: 19 October 2000
*Kamerlingh Onnes Lab of Leiden University * Jerry Gollub* AMYLUM GROUP* Rutgers University * Reade Advanced Material* NRC * Process- and Aerosol Measurement Technology 
In the condensed matter section of the Kamerlingh Onnes Lab of Leiden University there is an opening for an experimental postdoc. The research will be in the area of granular materials, and will focus on applying interferometric techniques to unravel the properties of stress networks.

The project is part of a larger effort at Leiden to build up experimental and theoretical work on granular media, and will be done in the group of Martin van Hecke and Peter Kes from the Kamerlingh Onnes Lab, and in collaboration with the theoretical group around Wim van Saarloos. The appointment is for maximal three years.

If you know of suitable candidates for our positions, could you please pass on this information?

Applications may be sent to either one of us and should include a CV with list of publications, brief description of research interests, and two letters of recommendation, preferably by December 1st 2000. The starting date is negotiable but the optimal starting time would be in the beginning of 2001.

For more information contact Martin van Hecke at the address given below.

Sincerely Yours,

Martin van Hecke ( tel ++ 31 71 527 5444
Peter Kes ( tel ++ 31 71 527 5472

Kamerlingh Onnes Laboratory
Postbus 9504 -- 2300 RA Leiden
The Netherlands.

Dear Colleague,

I anticipate filling a position for experimental research on granular materials and/or fluid mixing (pending a grant renewal) for the summer of 2000. The position requires an _experimental_ Ph.D. and demonstrated interest in nonlinear physics or fluids. Mentored teaching opportunities are also available for a candidate who might like to strengthen quanlfications in that area. Would one of your experimental students possibly be interested in this position?

A talented person wishing to explore the possibility of a faculty job in an institution where BOTH research and teaching are valued would have something unique to gain from working in this environment and collaborating with undergraduates. One of our talented undergraduate students won the national APS Apker Award for his research on fluid mixing.

Our program is also affiliated with The University of Pennsylvania, where we often attend seminars and colloquia. Penn is especially strong in the area of soft condensed matter physics. We are located in the attractive western suburbs of Philadelphia, close to many universities, cultural activities, and employment possibilities for spouses.

If you know of a suitable candidate, I would appreciate your asking her or him to send me a letter describing background and interests, and a CV. A letter from you would also be needed. E-mail is fine for correspondence. Haverford College is an equal opportunity / affirmative action employer.

Jerry Gollub

Extensive studies are being made of the dynamics of granular materials, by means of sensitive force measurements and rapid tracking of large numbers of particles. We are addressing questions of fundamental and practical importance that have been raised by recent theories, in which adaptive inhomogeneous force networks are thought to be important in governing the behavior of granular materials. This work includes the following:

A. We are investigating the dynamical behavior of granular matter that has been simultaneously sheared by rotation and fluidized by a controlled upward air flow. We are investigating the flow of these materials, and hope to understand precisely how momentum, material, and energy are transported.

B. We are extending previous studies of frictional dynamics in planar layers, by determining the influence of the size distribution and particle properties on the static strength and motion, by approaching the colloidal limit of small particle size, and by exploring the fracture-like phenomena we have observed in these materials.

C. We are studying avalanching and flows in inclined layers, making careful measurements of stability and creep, susceptibility to perturbations, velocity profiles and fluctuations. Obstructed flows are investigated as an illustrative case of practical interest.

We expect to compare this granular flow behavior with analogous conventional solid and fluid phenomena, to elucidate the special properties of particulates and to determine the usefulness of various theoretical paradigms. Some of these experiments have geophysical motivations.

We are also studying fluid mixing phenomena in thin layers and films. We recently discovered "persistent mixing patterns" in chaotic advection (Nature, October 21, 1999), and documented dramatic differences between chaotic and turbulent mixing. In this work, we use precise fluorescent imaging methods to study the efficiency of mixing and transport. Experimental studies of chaotic mixing using reactive components, and an exploratory study of mixing in small-scale devices, are under consideration..

For further information:
Jerry Gollub

Jerry Gollub

Dept. of Chemical & Biochemical Engineering, Rutgers University.

We anticipate hiring one or more postdoctoral fellows to study mixing and cooperative dynamics of granular materials. One of these fellows will (at least initially) take responsibility for studying molecular dynamics of granular mixing. The MD code is already written. We would like someone who thinks independently, follows leads through, writes well and works well with others. A second fellow will be responsible for granular, as well as fluid, mixing experiments, and a third opening is possible in computational fluid dynamics applied to practical mixing problems.

The group is a unique hybrid of fundamental, academic research and applied, industrial investigations with strong and growing support from industrial as well as governmental sources. Consequently the postdocs will involve both scientific research and involvement on engineering projects of interest to industry. More information about prior work is available at our web site. For info. about ongoing and future projects, interested parties may contact Troy Shinbrot ( or the director of the program, Fernando Muzzio (

  Job Title: Sales Engineer- Metal/Ceramic Powders

1) Reade Advanced Materials, located in America, is immediately accepting resumes for openings as full or part time sales engineers both in our East Coast USA (Providence, Rhode Island) and West Coast USA (Reno, Nevada) sales offices.

2) Responsibilities focus on technical sales support for a broad range of high technology situations for Fortune 500 customers-- Never a dull day!!

3) Understanding of ceramic and metal powder fundamentals helpful. Candidate must be outgoing and highly motivated. Excellent training provided. Comprehensive benefits package.

4) An Equal Opportunity Employer M/F/H/V.

5) Please mail your resume and cover letter to our Career Development Office at the address stated in our website .

Thank you.


E. S. Reade
Career Development Manager
Reade Advanced Materials
P. O. Box 15039
Providence, RI 02915-0039 USA

NRC Postdoctoral and senior research awards_Opportunities for research

The two descriptions given below may not have been updated in the web-page of the National research council (NRC). Nevetheless, the printed booklet published by the NRC (1998) does contain these descriptions. Please refer to the NRC web page for the details of the procedures to apply etc. and the following for the technical descriptions. For enquiries regarding this topic please call the following:
Ernest J. Bastian (703) 285-2086 | Naga Shashidhar (703) 285-2070

         Particulate Mechanics Modeling of Asphalt Concrete Pavements
Asphalt concrete is a composite material consisting of mineral aggregates, asphalt binder and air,
typically in a ratio 80:10:10 (by volume) respectively. Currently the asphalt concrete pavement is
modeled primarily by considering it as a non-linear continuum and applying continuum mechanics
principles. Such models are used to predict the stress-strain response of asphalt pavements, which in
turn is used to predict the life of asphalt concrete pavements. These models have an inherent
limitation_they do not provide direct feedback as to what material changes (gradation, asphalt
content, etc.) should be made in the mixture design to improve the global performance. They also
require the asphalt concrete specimens to be compacted and tested in order to apply such models.

This research opportunity focuses on applying continuum mechanics methods at a smaller scale than
normally considered with asphalt concrete.  Of primary interest is the use of  particulate mechanics
and contact mechanics methods to model the asphalt concrete as a collection of discrete particles.
Such model will provide an analytical connection between the observed global properties and the local
geometry and materials parameters.

It is envisioned that the modeling can be done in three steps: (1) model asphalt concrete as an
assemblage of aggregates (without binder) using particulate mechanics principles, (2) Apply suitable
contact mechanics to introduce the binder (or mastic) at the particle-particle contacts, and (3) apply
this model to virtual specimens reconstructed from non-destructive images of pavement core sections.
The facilities to verify the predicted response of the model to laboratory tests such as triaxial testing,
simple shear testing, indirect tensile testing or other tests are available. The virtual specimens for the
final phase modeling will be provided to the candidate through outside laboratories.

      Modeling the Structure of Asphalt Concrete
Asphalt concrete (AC) is a composite material consisting of mineral aggregates, asphalt binder and air
in a ratio 80:10:10 (by volume), respectively. Currently, choosing the gradation to construct the
pavement is based on experience and consensus. It will be of benefit to the highway community to
develop computer modeling techniques to better understand the aggregate structure and its
dependence on various factors such as surface roughness, angularity, etc. of the aggregates and
various properties of the binder. Research opportunity exists for modeling the microstructure of AC
using volumetrics and particle packing concepts to predict the volumetric properties for a given
aggregate properties and gradation. The modeling is expected to start by simulating the packing of
spherical /ellipsoid particles having a specified gradation, then add other factors such as surface
roughness, presence of asphalt binder and aggregate angularity. The model is expected to calculate
characteristics of the compacted asphalt mixture such as bulk density, voids content, void
distribution, average coordination number of each particle, etc., and yield information useful to mixture
design and particulate mechanics modeling of asphalt concrete.

Process- and Aerosol Measurement Technolog
In the section Process- and Aerosol Measurement Technology headed by Prof.Dr.-Ing. H. Fissan at the Gerhard-Mercator-University Duisburg we are looking for

Postdoc (f/m) (chemical or mechanical engineering, chemistry, physics, computer sciences, mathematics)

The section is active in research into practical and theoretical aspects of ultrafine particles and is distinguishes itself by an interdisciplinary approach, which is reflected in itsf coworkers coming from 5 different engineering or natural sciences. The section takes part in several special research programs including centers of excellence of the German National Science Foundation. Instrumentation development is mainly performed together with industry.

For the research project gDetermination of the distributed properties of solid particles by means of Monte-Carlo simulationsh we are recruiting two PhD students or Postdocs. The project is part of a larger research project gModeling and simulation in the manufacturing of chemical productsh financed by the Ministry of Education and Science of Nordrhein-Westfalen. The goal is to develop a simulation model, which is able to trace the development of distributed properties of industrial relevant particle-based systems such as aerosol reactors, grinders or crystallizers. The model bases on Monte-Carlo simulation techniques. The research comprises transforming chemical and physical processes into relevant models, the development of Monte-Carlo simulation techniques for particle-dynamical processes, the setup of a computer network which will be dedicated to this project and the implementation of case studies from the chemical industry. We are looking for chemical or mechanical engineers, physicist, computer scientists or mathematicians who are interested in modeling and numerical methods. A parallel computing system in worth of 100.000 DM is financed by the project and will be dedicated to the Monte-Carlo simulations.. Enthusiasm for an interdisciplinary theme and excellent ability for team work are prerequisite, as in the same project a chemical engineer and a computer scientist are working. The salary is according to BAT IIa. The positions are initially financed up to 31.12.2003, we hope to continue the project after that time. Send your complete application to Prof. Dr.-Ing. H. Fissan, Process- and Aerosol Measurement Technology, Gerhard-Mercator-University Duisburg, Bismarckstr. 81, 47048 Duisburg, Germany. For further information you can contact Dr .Kruis at Tel.: (49) 203 378 2899 and e-mail:

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