Electroplating eliminates gas leakage in brazed areas

Electroplating method seals brazed or welded joints against gas leakage under high pressure. Any conventional electroplating process with many different metal anodes can be used, as well as the build up of layers of different metals to any required thickness

Validity of the linear coupling approximation in heavy-ion fusion reactions at sub barrier energies

The role of higher order coupling of surface vibrations to the relative motion in heavy-ion fusion reactions at near-barrier energies is investigated. The coupled channels equations are solved to all orders, and also in the linear and the quadratic coupling approximations. Taking $^{64}$Ni + $^{92,96}$Zr reactions as examples, it is shown that all order couplings lead to considerably improved agreement with the experimentally measured fusion cross sections and average angular momenta of the compound nucleus for such heavy nearly symmetric systems. The importance of higher order coupling is also examined for asymmetric systems like $^{16}$O + $^{112}$Cd, $^{144}$Sm, for which previous calculations of the fusion cross section seemed to indicate that the linear coupling approximation was adequate. It is shown that the shape of the barrier distributions and the energy dependence of the average angular momentum can change significantly when the higher order couplings are included, even for systems where measured fusion cross sections may seem to be well reproduced by the linear coupling approximation.Comment: Latex file, 15 pages, 6 figure

IMPACT OF RISK PREFERENCES ON CROP ROTATION CHOICE

Stochastic dominance analysis of five crop rotations using twenty-one years of experimental yield data returned results consistent with Pennsylvania cropping practices. The analysis incorporated yield risk, output price risk, and rotational yield effects. A rotation of two years corn and three years alfalfa hay dominated for approximately risk neutral and risk averse preferences, as did participation in government programs under the 1990 Farm Bill. Crop rotation selection appeared to impact net revenues more than the decision to participate in government programs.Crop Production/Industries, Risk and Uncertainty,

Crop Consultants as Climate Consultants : An Extension Opportunity for Climate Change Communication

Extension personnel can augment climate change communication and efforts to decrease climate-related agricultural risks by engaging with producers\u27 trusted information sources, including crop consultants. Through a survey of inland Pacific Northwest wheat producers and in-depth interviews with area crop consultants, we examined relationships among producers, crop consultants, and climate change education and adaptation. We found that crop consultants are poised to communicate climate change information to producers, given their strong relationships with producers, practice of promoting adaptive management based on science, and ability to connect climate change to immediate on-farm practices. However, success in leveraging crop consultants to achieve widespread climate change adaptation will depend largely on Extension\u27s presenting the topic to them in accessible ways

Importance of Non-Linear Couplings in Fusion Barrier Distributions and Mean Angular Momenta

The effects of higher order coupling of surface vibrations to the relative motion on heavy-ion fusion reactions at near-barrier energies are investigated. The coupled channels equations are solved to all orders, and also in the linear and the quadratic coupling approximations. It is shown that the shape of fusion barrier distributions and the energy dependence of the average angular momentum of the compound nucleus can significantly change when the higher order couplings are included. The role of octupole vibrational excitation of ^{16}O in the ^{16}O + ^{144}Sm fusion reaction is also discussed using the all order coupled-channels equations.Comment: 8 pages, 6 figures, To be published in the Proceedings of the FUSION 97 Conference, South Durras, Australia, March 1997 (J. Phys. G

Genetic diversity at the FMR1 locus in the Indonesian population

We report an analysis of allelic diversity at short tandem repeat polymorphisms within the fragile XA locus in 1069 male volunteers from twelve Indonesian sub-populations. An odd numbered allele of DXS548 was found at high frequency in all Indonesian populations. Greater allelic diversity was identified at the loci under study than has been previously reported for an Asian population. These differences distinguish the Indonesian population from all previously reported Asian, European and African populations. A high frequency of small premutation alleles, 4/120 (3.3%, 95% CI 0.9–8.3%), was identified in the Moluccan population of Hiri Island

A search for starlight reflected from HD 75289 b

We have used a doppler tomographic analysis to conduct a deep search for the starlight reflected from the planetary companion to HD 75289. In 4 nights on VLT2/UVES in January 2003, we obtained 684 high resolution echelle spectra with a total integration time of 26 hours. We establish an upper limit on the planet's geometric albedo p < 0.12 (to the 99.9% significance level) at the most probable orbital inclination i ~ 60 degrees, assuming a grey albedo, a Venus-like phase function and a planetary radius R_p = 1.6 R_Jup. We are able to rule out some combinations of the predicted planetary radius and atmospheric albedo models with high, reflective cloud decks.Comment: 5 pages, 5 figures, MNRAS accepted 12 Oct 200

Potassium homeostasis in vacuolate plant cells

Plant cells contain two major pools of K+, one in the vacuole and one in the cytosol. The behavior of K+ concentrations in these pools is fundamental to understanding the way this nutrient affects plant growth. Triple-barreled microelectrodes have been used to obtain the first fully quantitative measurements of the changes in K+ activity (aK) in the vacuole and cytosol of barley (Hordeum vulgare L.) root cells grown in different K+ concentrations. The electrodes incorporate a pH-selective barrel allowing each measurement to be assigned to either the cytosol or vacuole. The measurements revealed that vacuolar aK declined linearly with decreases in tissue K+ concentration, whereas cytosolic aK initially remained constant in both epidermal and cortical cells but then declined at different rates in each cell type. An unexpected finding was that cytoplasmic pH declined in parallel with cytosolic aK, but acidification of the cytosol with butyrate did not reveal any short-term link between these two parameters. These measurements show the very different responses of the vacuolar and cytosolic K+ pools to changes in K+ availability and also show that cytosolic K+ homeostasis differs quantitatively in different cell types. The data have been used in thermodynamic calculations to predict the need for, and likely mechanisms of, active K+ transport into the vacuole and cytosol. The direction of active K+ transport at the vacuolar membrane changes with tissue K+ status

AN INTEGRATED METHOD TO OBTAIN THREE-DIMENSIONAL COORDINATES USING PANNING AND TILTING VIDEO CAMERAS

Kinematic measurements of sports performances have generally been gathered using stationary cameras. Many activities, however, cover dimensions that are much larger than the athlete, resulting in measures that are less accurate than desired. One solution is to increase the resolution of the acquisition equipment. Hardware providing sufficient resolution, if possible to find, may be prohibitively expensive. Another solution is to use rotating cameras to follow the athlete’s movements. Until now, this procedure demanded time-consuming calibrations and expensive, specialized equipment. An efficient, accurate, and inexpensive method was developed to quantify threedimensional motion from rotating video cameras. The procedure uses two 20,000 count/revolution optical encoders embedded in specially machined tripod heads to sense the angular positions of the cameras. One encoder is aligned vertically to measure pan positions, while the other is aligned horizontally to measure tilt. The pan and tilt angles are printed on each video image by an interface unit. The images are then recorded on videotape and imported into a computer using a commercial frame grabber. Locations on the body may be identified manually or automatically if markers are placed on the athlete. As the points are tracked, the pan and tilt angles are decoded and stored with the digitized data. Custom software modules use these data to compute the 3D coordinates via ray-tracing techniques. Calibration, conducted before or after the performance, requires three to nine vertical rods of known length placed near the volume of interest. No on-site measurements or background markers are needed. Furthermore, calibration does not restrict camera positioning; the locations depend upon the focal length of the camera lenses, the resolution of the encoders, the shape of the movement volume, and the speed of the athlete. Dynamic accuracy was measured by moving a 0.900 m long rod through a 2 m x 4 m x 15 m volume while sampling from two 60 Hz video cameras. Nine hundred images were analyzed. The endpoints of the rod were digitized and its length computed for each video image. The mean length of the rod was 0.891 m and the Root Mean Square Error was 0.005 m. These measures compared better than other reported methods. Applications have ranged from multi-stride running in the laboratory or on a track, long jumping, high jumping, gymnastics, pole vaulting, and ski jumping