Dispersion of waves in porous cylinders with patchy saturation Part I. Formulaton and torsional waves (open access)

Dispersion of waves in porous cylinders with patchy saturation Part I. Formulaton and torsional waves

Laboratory experiments on wave propagation through saturated and partially saturated porous media have often been conducted on porous cylinders that were initially fully saturated and then allowed to dry while continuing to acquire data on the wave behavior. Since it is known that drying typically progresses from outside to inside, a sensible physical model of this process is concentric cylinders having different saturation levels--the simplest example being a fully dry outer cylindrical shell together with a fully wet inner cylinder. We use this model to formulate the equations for wave dispersion in porous cylinders for patchy saturation (i.e. drainage) conditions. In addition to multiple modes of propagation obtained numerically from these dispersion relations, we find two distinct analytical expressions for torsional wave modes. We solve the dispersion relation for torsional waves for two examples: Massillon sandstone and Sierra White granite. The drainage analysis appears to give improved agreement with the data for both these materials.
Date: July 28, 2004
Creator: Berryman, J G & Pride, S R
System: The UNT Digital Library
RESULTS OF THE FIRST RUN OF THE NASA SPACE RADIATION LABORATORY AT BNL. (open access)

RESULTS OF THE FIRST RUN OF THE NASA SPACE RADIATION LABORATORY AT BNL.

The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The results of commissioning of this new facility were reported in [l]. In this report we will describe the results of the first run. The NSRL is capable of making use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. Many modes of operation were explored during the first run, demonstrating all the capabilities designed into the system. Heavy ion intensities from 100 particles per pulse up to 12 x 10{sup 9} particles per pulse were delivered to a large variety of experiments, providing a dose range up to 70 Gy/min over a 5 x 5 cm{sup 2} area. Results presented will include those related to the production of beams that are highly uniform in both the transverse and longitudinal planes of motion [2].
Date: July 5, 2004
Creator: BROWN,K. A. AHRENS,L. BRENNAN,J. M. ET. AL.
System: The UNT Digital Library
Results From the Commissioning of the Nsrl Beam Transfer Line at Bnl. (open access)

Results From the Commissioning of the Nsrl Beam Transfer Line at Bnl.

The NASA SPACE RADIATION LABORATORY (NSRL) has been constructed and started operations at the Brookhaven National Laboratory in 2003. The NSRL facility will be used by NASA to perform radiation effect studies on materials and biological samples for the space program. The facility utilizes proton and heavy-ion beams of energies from 50 to 3000 MeVln which are accelerated by the AGS Booster synchrotron accelerator. To date, {sup 1}H, {sup 12}C, {sup 56}Fe, {sup 48}Ti, and {sup 197}Au ion beams of various magnetic rigidities have been extracted from the Booster, and transported by the NSRL beam transport line to the sample location which is located 100 m from the extraction point. The NSRL beam transport line has been designed to employ octupole magnetic elements which transform the normal (Gaussian) beam distribution at the location of the sample into a beam with rectangular cross section, and uniformly distributed over the sample. When using the octupole magnetic elements to obtain the uniform beam distribution on the sample, no beam-collimation is applied at any location along the NSRL beam transport line and the beam focusing on the sample is purely magnetic. The main subject of this paper will be the performance of the octupoles …
Date: July 5, 2004
Creator: Tsoupas, N.; Bellavia, S.; Bonati, R. & Al., Et
System: The UNT Digital Library
Whole-genome shotgun optical mapping of rhodospirillumrubrum (open access)

Whole-genome shotgun optical mapping of rhodospirillumrubrum

Rhodospirillum rubrum is a phototrophic purple non-sulfur bacterium known for its unique and well-studied nitrogen fixation and carbon monoxide oxidation systems, and as a source of hydrogen and biodegradable plastics production. To better understand this organism and to facilitate assembly of its sequence, three whole-genome restriction maps (Xba I, Nhe I, and Hind III) of R. rubrum strain ATCC 11170 were created by optical mapping. Optical mapping is a system for creating whole-genome ordered restriction maps from randomly sheared genomic DNA molecules extracted directly from cells. During the sequence finishing process, all three optical maps confirmed a putative error in sequence assembly, while the Hind III map acted as a scaffold for high resolution alignment with sequence contigs spanning the whole genome. In addition to highlighting optical mapping's role in the assembly and validation of genome sequence, our work underscores the unique niche in resolution occupied by the optical mapping system. With a resolution ranging from 6.5 kb (previously published) to 45 kb (reported here), optical mapping advances a ''molecular cytogenetics'' approach to solving problems in genomic analysis.
Date: July 1, 2004
Creator: Reslewic, Susan; Zhou, Shiguo; Place, Mike; Zhang, Yaoping; Briska, Adam; Goldstein, Steve et al.
System: The UNT Digital Library
Functional glass slides for in vitro evaluation of interactions between osteosarcoma TE85 cells and mineral-binding ligands (open access)

Functional glass slides for in vitro evaluation of interactions between osteosarcoma TE85 cells and mineral-binding ligands

Primary amine-functionalized glass slides obtained through a multi-step plasma treatment were conjugated with anionic amino acids that are frequently found as mineral binding elements in acidic extracellular matrix components of natural bone. The modified glass surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. Human osteosarcoma TE85 cells were cultured on these functionalized slides and analyses on both protein and gene expression levels were performed to probe the ''biocompatibility'' of the surface ligands. Cell attachment and proliferation on anionic surfaces were either better than or comparable to those of cells cultured on tissue culture polystyrene (TCPS). The modified glass surfaces promoted the expression of osteocalcin, alkaline phosphatase activity and ECM proteins such as fibronectin and vitronectin under differentiation culture conditions. Transcript analysis using gene chip microarrays confirmed that culturing TE85 cells on anionic surfaces did not activate apoptotic pathways. Collectively, these results suggest that the potential mineral-binding anionic ligands examined here do not exert significant adverse effects on the expression of important osteogenic markers of TE85 cells. This work paves the way for the incorporation of these ligands into 3-dimensional artificial bone-like scaffolds.
Date: July 20, 2004
Creator: Song, Jie; Chen, Julia; Klapperich, Catherine M.; Eng, Vincent & Bertozzi, Carolyn R.
System: The UNT Digital Library
SECA Annual Workshop and Core Technology Peer Review (open access)

SECA Annual Workshop and Core Technology Peer Review

Proceedings of the SECA Annual Workshop and Core Technology Meeting.
Date: July 15, 2004
Creator: NETL & PNNL
System: The UNT Digital Library