652 research outputs found
Runaway evaporation for optically dressed atoms
Forced evaporative cooling in a far-off-resonance optical dipole trap is
proved to be an efficient method to produce fermionic- or bosonic-degenerated
gases. However in most of the experiences, the reduction of the potential
height occurs with a diminution of the collision elastic rate. Taking advantage
of a long-living excited state, like in two-electron atoms, I propose a new
scheme, based on an optical knife, where the forced evaporation can be driven
independently of the trap confinement. In this context, the runaway regime
might be achieved leading to a substantial improvement of the cooling
efficiency. The comparison with the different methods for forced evaporation is
discussed in the presence or not of three-body recombination losses
The Effects of Conjoint Behavioral Consultation: Results of a 4-Year Investigation
Conjoint behavioral consultation (CBC) is a structured indirect form of service delivery in which parents, teachers, and other support staff are joined to work together to address the academic, social, or behavioral needs of an individual for whom all parties bear some responsibility. In this article, outcome data from 4 years of federally funded projects in the area of CBC are presented. Thirty graduate students were trained in CBC and were responsible for providing consultation services to parents and teachers of students with disabilities or at risk for academic failure. Consultation clients included 52 students with disabilities such as behavior disorders, attention-deficit hyperactivity disorder, anxiety, and learning disabilities. The primary research objective concerned assessing the efficacy of CBC across home and school settings. Secondarily, a prediction model was investigated based on client age, case complexity, and severity of symptoms. Perception of effectiveness, process acceptability, and consultee satisfaction with consultants was also investigated. Meaningful effect sizes were yielded across home and school settings. A model fitting client age and symptom severity was found to predict school effect size relatively well. Consultees’ perceptions of effectiveness, acceptability of CBC, and satisfaction with consultants were also favorable. Implications of these findings and directions for future research are explored
Manue Application Effects on Residue, Odor, and Placement
Field experiments in no-till soybean and corn residue were conducted to evaluate six liquid swine manure application methods. The methods were injection with a conventional knife or sweep, incorporation with tandem disk after broadcast application, broadcast application, injection with a narrow-profile knife, and surface application behind row cleaners. The row cleaner and all injection treatments used finger-closing wheels. Air samples over the soil surface were obtained during and after application and residue cover was measured. Odor level was measured by the amount of air dilutions to reach odor threshold. Placement of material into the soil was evaluated with dye. Incorporation techniques typically reduced odor level by a factor of four to ten as compared to a broadcast application. Differences among application methods were more pronounced in soybean residue. Application by the narrow-profile knife, row cleaner, and to a lesser extent the conventional knife maintained soybean residue cover better than other incorporation methods and limited odor similar to other incorporation methods. Differences among methods in odor level and residue cover were less in corn. The knife and row cleaner methods maintained greater corn residue cover than other incorporation techniques, but were more variable in odor level. For both crops, broadcast application maintained the greatest residue cover, but had the highest odor level. Material was incorporated five to seven inches deep by the knife, sweep, and narrow knife; two to three inches deep by the tandem disk and row cleaner; and at the surface by broadcast application
Doping Effect of Nano-Diamond on Superconductivity and Flux Pinning in MgB2
Doping effect of diamond nanoparticles on the superconducting properties of
MgB2 bulk material has been studied. It is found that the superconducting
transition temperature Tc of MgB2 is suppressed by the diamond-doping, however,
the irreversibility field Hirr and the critical current density Jc are
systematically enhanced. Microstructural analysis shows that the diamond-doped
MgB2 superconductor consists of tightly-packed MgB2 nano-grains (~50-100 nm)
with highly-dispersed and uniformly-distributed diamond nanoparticles (~10-20
nm) inside the grains. High density of dislocations and diamond nanoparticles
may take the responsibility for the enhanced flux pinning in the diamond-doped
MgB2.Comment: 16 pages, 6 figure
Selective G-Quadruplex DNA Recognition by a New Class of Designed Cyanines
A variety of cyanines provide versatile and sensitive agents acting as DNA stains and sensors and have been structurally modified to bind in the DNA minor groove in a sequence dependent manner. Similarly, we are developing a new set of cyanines that have been designed to achieve highly selective binding to DNA G-quadruplexes with much weaker binding to DNA duplexes. A systematic set of structurally analogous trimethine cyanines has been synthesized and evaluated for quadruplex targeting. The results reveal that elevated quadruplex binding and specificity are highly sensitive to the polymethine chain length, heterocyclic structure and intrinsic charge of the compound. Biophysical experiments show that the compounds display significant selectivity for quadruplex binding with a higher preference for parallel stranded quadruplexes, such as cMYC. NMR studies revealed the primary binding through an end-stacking mode and SPR studies showed the strongest compounds have primary KD values below 100 nM that are nearly 100-fold weaker for duplexes. The high selectivity of these newly designed trimethine cyanines for quadruplexes as well as their ability to discriminate between different quadruplexes are extremely promising features to develop them as novel probes for targeting quadruplexes in vivo
System for Contributing and Discovering Derived Mission and Science Data
A system was developed to provide a new mechanism for members of the mission community to create and contribute new science data to the rest of the community. Mission tools have allowed members of the mission community to share first order data (data that is created by the mission s process in command and control of the spacecraft or the data that is captured by the craft itself, like images, science results, etc.). However, second and higher order data (data that is created after the fact by scientists and other members of the mission) was previously not widely disseminated, nor did it make its way into the mission planning process
Numerical modeling of collisional dynamics of Sr in an optical dipole trap
We describe a model of inelastic and elastic collisional dynamics of atoms in an optical dipole trap that utilizes numerical evaluation of statistical mechanical quantities and numerical solution of equations for the evolution of number and temperature of trapped atoms. It can be used for traps that possess little spatial symmetry and when the ratio of trap depth to sample temperature is relatively small. We compare simulation results with experiments on Sr88 and Sr84, which have well-characterized collisional properties
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