For background information on particle technology, see Particle Technology Overview.
 

Research Focus Areas                                                 

The overall goal of this research program is to further the understanding of the detailed flow behavior of a variety of particulate systems. Specific focus areas include:

Granular Flows. In these systems, the role of the interstitial fluid is negligible due to the relatively large mass of the particles. Of particular interest is the effect of particle size distributions, particle clustering, and cohesive forces on the flow behavior.

Gas-Particle Fluidization. Although particle-particle collisions remain important in these systems due to the relatively large particle mass, the role of the drag force between the two phases is also an important factor. Areas of research in gas-solid flows include scale-up, nonuniform size distributions, particle clustering, and cohesive forces.

Aerosol Systems. Due to the small mass of the particles contained in these systems relative to the previous two categories, Brownian motion of the particles cannot be ignored. Current efforts in this area are focused on the thermophoretic deposition of particles in vertical aerosol flow reactors.

Computer Resources

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General Cluster Information
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Hardware
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The muthaship cluster is a large group of diskless clients that boot from
a single server (muthaship).

There is a current list of clients, called nodes, that lives in
/tftpboot/NODELIST.  This list details nodes that should be up, CPU
speed, and memory for each node.

Muthaship's disk partitions /home and /data are backed up nightly to a
backup server.  However, /raid IS NOT BACKED UP.  It is a RAID, and as such
can suffer a drive failure without loss of data.  However, if you remove a
file from /raid it can not be restored.  Be mindful of that when working
with files in /raid.

Questions or notifications about problems with the cluster can be directed
to trouble@muthaship.colorado.edu.



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Utilities
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For your convenenience, several items have been prepared for easier use of the
cluster.  These items are, however, out of the scope of UnixOps and the help
available via trouble@muthaship.colorado.edu.

First, the command './new_processes' may be used to indicate which machines are
free or in use.  Jobs that are currently running on a given machine will appear
under the machine name along with the associated username and the percentage of
the processor being used.  If a machine appears to be free, however, it is
important to confirm a machine's availability by running the 'top' command on
the machin in question prior to beginning a process, since the new_processes
script sometimes overlooks active processes. Within 'top', use 'q' to quit
monitoring the active processes.

Second, a 'screen' session has been designed for your convenience in navigating
the many machines available on the cluster.  Upon first use of a screen session
(i.e., after a fresh boot-up, etc.), use the 'screen' command to begin the
session.  At this point, a series of 'screens' will become available within the
terminal you are currently using.  The name of the current window appears at
the lower right-hand corner of the terminal, next to the current time.  The
majority of the windows are named according to the nodes onto which they are
logged (i.e., cf##).  Windows not following this naming scheme are associated
with the server itself (i.e., muthaship).  The machine in use by a particular
screen may be confirmed by observation of the command prompt for that screen.  

Once the screen session has been started, jobs may be started and the content
of individual screens (e.g., a session of vim, octave, your code, etc.) may be
set up as desired.  Navigation of the screens and other manipulation thereof
may be achieved by the commands listed below.  The terminal that you are using
may be closed at any time (i.e., the window that you are using may be closed)
and revisited again by logging into muthaship and using the command      
'screen -Ax'.  WARNING: Using the 'screen' command multiple times without the
'-Ax' flag will result in multiple screen sessions and frustration.  

If the need arises to quit the screen session entirely, type '^A:quit<Enter>'
within the screen session.  Begin a new screen session by using the 'screen'
command at a prompt.  

For more commands and info regarding the screen utility, use the command 'man
screen' at any prompt.


LIST OF SCREEN COMMANDS
=========================
^A<space> Move to next screen number
^A<backspace> Move to previous screen number
^A^A Move to the last screen being used
^A^C Create a new screen
^AA Prompt for the naming of a screen
^A" Bring up a list of screens.  Navigate with up/down arrows.
^A' Prompt for desired screen number

(Note: ^ indicates that the control key is pressed along with the following
character.  Any character following the control need not be capitalized.  In
other words, the shift key need not be pressed along with control.)
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