Possible discovery of the r-process characteristics in the abundances of metal-rich barium stars

We study the abundance distributions of a sample of metal-rich barium stars provided by Pereira et al. (2011) to investigate the s- and r-process nucleosynthesis in the metal-rich environment. We compared the theoretical results predicted by a parametric model with the observed abundances of the metal-rich barium stars. We found that six barium stars have a significant r-process characteristic, and we divided the barium stars into two groups: the r-rich barium stars ($C_r>5.0$, [La/Nd]\,$<0$) and normal barium stars. The behavior of the r-rich barium stars seems more like that of the metal-poor r-rich and CEMP-r/s stars. We suggest that the most possible formation mechanism for these stars is the s-process pollution, although their abundance patterns can be fitted very well when the pre-enrichment hypothesis is included. The fact that we can not explain them well using the s-process nucleosynthesis alone may be due to our incomplete knowledge on the production of Nd, Eu, and other relevant elements by the s-process in metal-rich and super metal-rich environments (see details in Pereira et al. 2011).Comment: 5 pages, 5 figures, accepted for publication in A&

Parsec-scale jet properties of the gamma-ray quasar 3C 286

The quasar 3C~286 is one of two compact steep spectrum sources detected by the {\it Fermi}/LAT. Here, we investigate the radio properties of the parsec(pc)-scale jet and its (possible) association with the $\gamma$-ray emission in 3C~286. The Very Long Baseline Interferometry (VLBI) images at various frequencies reveal a one-sided core--jet structure extending to the southwest at a projected distance of $\sim$1 kpc. The component at the jet base showing an inverted spectrum is identified as the core, with a mean brightness temperature of $2.8\times 10^{9}$~K. The jet bends at about 600 pc (in projection) away from the core, from a position angle of $-135^\circ$ to $-115^\circ$. Based on the available VLBI data, we inferred the proper motion speed of the inner jet as $0.013 \pm 0.011$ mas yr$^{-1}$ ($\beta_{\rm app} = 0.6 \pm 0.5$), corresponding to a jet speed of about $0.5\,c$ at an inclination angle of $48^\circ$ between the jet and the line of sight of the observer. The brightness temperature, jet speed and Lorentz factor are much lower than those of $\gamma$-ray-emitting blazars, implying that the pc-scale jet in 3C~286 is mildly relativistic. Unlike blazars in which $\gamma$-ray emission is in general thought to originate from the beamed innermost jet, the location and mechanism of $\gamma$-ray emission in 3C~286 may be different as indicated by the current radio data. Multi-band spectrum fitting may offer a complementary diagnostic clue of the $\gamma$-ray production mechanism in this source.Comment: 9 pages, 4 figures, accept for publication in MNRA

QTL analysis of kernel soluble sugar content in supersweet corn

A genetic linkage map was constructed with SSR markers based on a super-sweet corn population consisting of 208 F2 individuals from the cross Ji557 (sh2) × Ji165 (sh2). Density of the linkage groups varied from 2.2 cM to 65.3 cM, with an average of 13.0 2 cM between two adjacent markers. The map covered 1470.9 cM of the total recombination length of the super-sweet corn. Using Mapmaker/QTL, 11 quantitative trait loci (QTLs) were identified for kernel soluble sugar content, explaining 3.5 - 20.3% of soluble sugar content variance and collectively accounting for 63.7% of the trait variance. Of the 11QTLs associated with kernel soluble sugar content, 2 (18.2%) showed additive effects, 3 (27.3%) showed partially dominant effects, 3 (27.3%) showed dominant effects and 3 (27.3%) showed over-dominant effects. All four types of genetic effects appeared to play important roles in determining the kernelsoluble sugar content in super-sweet corn cultivars

Soil-mechanics based testbed setup for lunar rover wheel and corresponding experimental investigations

This paper introduced a testbed developed from a perspective of soil mechanics which not only focused on wheel design and optimization but also considered the elimination of the boundary effect caused by soil bin. Using this testbed, a series of experimental investigations were performed by changing the wheel rotational velocity, vertical load and towed load. Tracks were generated at a regular spacing as the wheel lugs enter and exit the soil periodically. It has been found that there is a relationship between the track length and wheel slip ratio regardless of different mechanical properties of soil. The wheel rotational velocity has little effect on the driving torque and sinkage. The towed load affects more on the driving torque than on the sinkage. However, the vertical load effects on the driving torque and sinkage are similar. The current models used for parameter estimations may not be appropriate for TJ-1 lunar soil simulant which has a relatively high internal friction angle according to the experimental results. But the internal friction angle and cohesion can still be estimated with proper selection of shear deformation modulus using the model proposed by Li et al(2011)

Mold Fabrication for 3D Dual Damascene Imprinting

Previously, a damascene process based on nanoimprint lithography has been proposed (Schmid G M, et al. in J Vac Sci Technol B 24(3) 1283, 2006) to greatly reduce the fabrication steps of metal interconnection in integrated circuit. For such a process to become a viable technique, a mold having two pattern levels with precise alignment between them must be fabricated first. To this end, this work demonstrates a “self-aligned” fabrication process where the two pattern levels would be perfectly aligned if ignoring the noise during e-beam writing. The process is based on one EBL on a bi-layer resist stack, with the sensitivity for the top layer much higher than that of the bottom layer, which enables separate pattern transfer of the two pattern levels. Using ZEP-520A and poly(dimethylglutarimide) (PMGI) resists, we fabricated pillars having a diameter of 150 nm sitting on ridges having a width of 1.5 μm, which can be used to create via-holes and trenches for IC interconnect by nanoimprint lithography. The current process can also find applications in other areas that require two-level patterning with precise alignment between them

Preparation and Characterization of Colon-Specific Microspheres of Diclofenac for Colorectal Cancer

Purpose: To prepare and evaluate colon specific drug delivery system of diclofenac sodium for highly localized delivery to the colon.Methods: The colon specific drug delivery system was prepared as matrix-type microspheres using Ethyl Cellulose (EC), Cellulose Acetate Phthalate (CAP), and Eudragit L 100-55 by the Solvent Evaporation Method. Microspheres were evaluated for physical properties like drug content, particle size, bulk density and angle of repose.Results: The size range of the microcapsules was 228 to 608 μm while drug content was between 74.49 and 91.50 % depending on the polymer used and the  polymer ratio. Mean bulk density was &lt; 1.2 g/ml which indicates the good flow properties, while angle of repose was &lt; 40 o, indicating free-flowing properties. The microspheres were spherical in shape with smooth and nonporous surface, except that the microspheres containing EC and CAP exhibited a rough and porous  surface. The microspheres containing Eudragit L 100-55 in combination with other polymers gave better sustained release (78.9 and 76.6 % at the end of 8 h for  formulation F4 and F5, respectively) than the others.Conclusion: Microspheres prepared with drug: EC: CAP ratio of 1:2:1 show the highest drug content, possess good flow properties and surface morphology, as well as promising drug release for colon specific drug delivery of diclofenac sodium for possible treatment of colorectal cancer.Keywords: Diclofenac, Colorectal cancer, Microspheres, Ethyl cellulose, Cellulose acetate phthalate, Eudragit L 100-5