Anchored multi-phasic osteochondral construct

Disclosed are osteochondral constructs that can be utilized to encourage both bone and articular cartilage tissue repair in synovial joints. Disclosed constructs are composites including a hydrogel portion for implant in a cartilage defect site and an adjacent portion for implant in a bone defect site. The portion to be implanted in a bone defect site can include a polymeric/ceramic composite material. Disclosed constructs also include a polymeric anchor that can secure the construct at the desired site. Disclosed constructs can also include capillary channeled fibers within the bone portion of the construct that can provide improved nutrient flow to and waste flow from cells growing and developing on and in the construct

Thermal emittance measurements of a cesium potassium antimonide photocathode

Thermal emittance measurements of a CsK2Sb photocathode at several laser wavelengths are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. The thermal emittance is 0.56+/-0.03 mm-mrad/mm(rms) at 532 nm wavelength. The results are compared with a simple photoemission model and found to be in a good agreement.Comment: APL 201

Managing Soybean Rustin South Dakota in 2006

Soybean rust, caused by the fungus Phakopsora pachyrhizi, was first introduced to the U.S. in Fall 2004. It survived the winter in small pockets of infected kudzu in Florida and produced a widespread low-severity disease in the southeastern U.S. in 2005. During Winter 2005, the pathogen survived over a much wider area and appears to have become established in Mexico. That means the threat from soybean rust is greater in 2006 than in 2005, and we can expect that the threat will generally increase over the coming years as the pathogen becomes established in new areas with little risk of winter freeze. Fungicides remain the only practical and effective control for this disease. Several fungicides have received EPA labeling and more products are being considered. Which fungicide products are available is a constantly changing landscape. Check with your local county Extension office for a listing of the most current products or go to http://plantsci.sdstate.edu/planthealth and link to Soybean Rust

Determination of Fluorescence Polarization and Absorption Anisotropy in Molecular Complexes Having Threefold Rotational Symmetry

The current work concerns investigation of the polarization properties of complex molecular ensembles exhibiting threefold (C3) rotational symmetry, particularly with regard to the interplay between their structure and dynamics of internal energy transfer. We assume that the molecules or chromophores in such complexes possess strongly overlapped spectra both for absorption and fluorescence. Such trimeric structures are widely found in biological preparations, as for example the trimer of C-phycocyanin (C-PC). Higher order aggregates, e.g. hex-amers and three-hexamer rods, are also investigated and compared with the trimer case. The theory addresses both steady-state and 8-pulse excitation and establishes some links between them. Monochromophoric, bichro-mophoric and trichromophoric molecular complexes are individually examined. For steady-state excitation, analytical formulas are reported for the degree of fluorescence polarization and absorption anisotropy. It is shown that the polarization is dependent on the chromophore inclination relative to the symmetry axis, the relative efficiencies of absorption and fluorescence by chromophores of different spectral types, and the rates of energy equilibration. To assess the validity of the theory, it has been applied to C-PC aggregates. Here it was found that different C-PC aggregates provide practically identical polarization response. For S-pulse excitation we give analytical formulas for determination of the fluorescence depolarization, and also the depolarization associated with absorption recovery, both for a monochromophoric trimer and some particular cases of bichromophoric trimer. More complicated systems are analyzed by computer modeling. Thus it transpires that the initial polarization anisotropy r(t = 0) takes the value 0.4 for all considered aggregates; the long-time limit r(t →∞) has about the same value as is associated with steady-state excitation. We also show that with steady-state excitation the degree of fluorescence polarization is practically equal for various C3 aggregates of C-PC, and that the major factor determining the polarization is the chromophore orientation relative to the symmetry axis

Photocathode Behavior During High Current Running in the Cornell ERL Photoinjector

The Cornell University Energy Recovery Linac (ERL) photoinjector has recently demonstrated operation at 20 mA for approximately 8 hours, utilizing a multialkali photocathode deposited on a Si substrate. We describe the recipe for photocathode deposition, and will detail the parameters of the run. Post-run analysis of the photocathode indicates the presence of significant damage to the substrate, perhaps due to ion back-bombardment from the residual beamline gas. While the exact cause of the substrate damage remains unknown, we describe multiple surface characterization techniques (X-ray fluorescence spectroscopy, X-ray diffraction, atomic force and scanning electron microscopy) used to study the interesting morphological and crystallographic features of the photocathode surface after its use for high current beam production. Finally, we present a simple model of crystal damage due to ion back-bombardment, which agrees qualitatively with the distribution of damage on the substrate surface.Comment: 20 pages, 15 figure

Better Pumps: Reliable Handpump Infrastructure

Approximately 90 million people in Africa lack access to safe drinking water, despite having water infrastructure installed in their community. The India Mark II and the Afridev handpumps are among the most widely used handpumps in the world. Sadly, studies show that approximately 30% of these handpumps are non-operational due to failures of the bearings, seals, head flange, and other common components. The Better Pumps team of the Collaboratory provides engineering support for partners who are working to improve handpump sustainability. We partnered with Tony Beers and AlignedWorks to validate a bearing test methodology for the India Mark II handpump. By modifying the loading conditions in our handpump test machine, we were able to replicate failures observed by AlignedWorks in a field trial of their bearing design. We partnered with Matt Schwiebert and Living Water International to test new seal designs for the India Mark II and Afridev handpumps and to measure head flange deflections in the India Mark II handpump. Seal performance data collected by the team was used to validate a new design in advance of field trials by Living Water International. Head flange deflection data was collected for partner benchmarking of their computational analysis. Test methodologies and results are reported.https://mosaic.messiah.edu/engr2021/1000/thumbnail.jp