Design sensitivity analysis of nonlinear structural response

A unified theory is described of design sensitivity analysis of linear and nonlinear structures for shape, nonshape and material selection problems. The concepts of reference volume and adjoint structure are used to develop the unified viewpoint. A general formula for design sensitivity analysis is derived. Simple analytical linear and nonlinear examples are used to interpret various terms of the formula and demonstrate its use

Strong inapproximability of the shortest reset word

The \v{C}ern\'y conjecture states that every $n$-state synchronizing automaton has a reset word of length at most $(n-1)^2$. We study the hardness of finding short reset words. It is known that the exact version of the problem, i.e., finding the shortest reset word, is NP-hard and coNP-hard, and complete for the DP class, and that approximating the length of the shortest reset word within a factor of $O(\log n)$ is NP-hard [Gerbush and Heeringa, CIAA'10], even for the binary alphabet [Berlinkov, DLT'13]. We significantly improve on these results by showing that, for every $\epsilon>0$, it is NP-hard to approximate the length of the shortest reset word within a factor of $n^{1-\epsilon}$. This is essentially tight since a simple $O(n)$-approximation algorithm exists.Comment: extended abstract to appear in MFCS 201

Mesomorphic properties of alkoxybenzylidene- aminoacetophenones

Liquid crystal phase transitions in compounds of alkoxybenzylidene-aminoacetophene serie

On the NP-Hardness of Approximating Ordering Constraint Satisfaction Problems

We show improved NP-hardness of approximating Ordering Constraint Satisfaction Problems (OCSPs). For the two most well-studied OCSPs, Maximum Acyclic Subgraph and Maximum Betweenness, we prove inapproximability of $14/15+\epsilon$ and $1/2+\epsilon$. An OCSP is said to be approximation resistant if it is hard to approximate better than taking a uniformly random ordering. We prove that the Maximum Non-Betweenness Problem is approximation resistant and that there are width-$m$ approximation-resistant OCSPs accepting only a fraction $1 / (m/2)!$ of assignments. These results provide the first examples of approximation-resistant OCSPs subject only to P $\neq$ \NP

State-insensitive bichromatic optical trapping

We propose a scheme for state-insensitive trapping of neutral atoms by using light with two independent wavelengths. In particular, we describe the use of trapping and control lasers to minimize the variance of the potential experienced by a trapped Rb atom in ground and excited states. We present calculated values of wavelength pairs for which the 5s and 5p_{3/2} levels have the same ac Stark shifts in the presence of two laser fields.Comment: 5 pages, 4 figure

Antibacterial and phytochemical screening of Anethum graveolens, Foeniculum vulgare and Trachyspermum ammi

<p>Abstract</p> <p>Background</p> <p><it>Anethum graveolens </it>Linn., <it>Foeniculum vulgare </it>Mill. and <it>Trachyspermum ammi </it>L. are widely used traditional medicinal plants to treat various ailments. To provide a scientific basis to traditional uses of these plants, their aqueous and organic seed extracts, as well as isolated phytoconstituents were evaluated for their antibacterial potential.</p> <p>Methods</p> <p>Antibacterial activity of aqueous and organic seed extracts was assessed using agar diffusion assay, minimum inhibitory concentration and viable cell count studies; and their antibacterial effect was compared with some standard antibiotics. The presence of major phytoconstituents was detected qualitatively and quantitatively. The isolated phytoconstituents were subjected to disc diffusion assay to ascertain their antibacterial effect.</p> <p>Results</p> <p>Hot water and acetone seed extracts showed considerably good antibacterial activity against all the bacteria except <it>Klebsiella pneumoniae </it>and one strain of <it>Pseudomonas aeruginosa</it>. Minimum inhibitory concentration for aqueous and acetone seed extracts ranged from 20–80 mg/ml and 5–15 mg/ml respectively. Viable cell count studies revealed the bactericidal nature of the seed extracts. Statistical analysis proved the better/equal efficacy of some of these seed extracts as compared to standard antibiotics. Phytochemical analysis showed the presence of 2.80 – 4.23% alkaloids, 8.58 – 15.06% flavonoids, 19.71 – 27.77% tannins, 0.55–0.70% saponins and cardiac glycosides.</p> <p>Conclusion</p> <p>Antibacterial efficacy shown by these plants provides a scientific basis and thus, validates their traditional uses as homemade remedies. Isolation and purification of different phytochemicals may further yield significant antibacterial agents.</p

Electric Quadrupole Moments of Metastable States of Ca+, Sr+, and Ba+

Electric quadrupole moments of the metastable nd3/2 and nd5/2 states of Ca+, Sr+, and Ba+ are calculated using the relativistic all-order method including all single, double, and partial triple excitations of the Dirac-Hartree-Fock wave function to provide recommended values for the cases where no experimental data are available. The contributions of all non-linear single and double terms are also calculated for the case of Ca+ for comparison of our approach with the CCSD(T) results. The third-order many body perturbation theory is used to evaluate contributions of high partial waves and the Breit interaction. The remaining omitted correlation corrections are estimated as well. Extensive study of the uncertainty of our calculations is carried out to establish accuracy of our recommended values to be 0.5% - 1% depending on the particular ion. Comprehensive comparison of our results with other theoretical values and experiment is carried out. Our result for the quadrupole moment of the 3d5/2 state of Ca+ ion, 1.849(17)ea_0^2, is in agreement with the most precise recent measurement 1.83(1)ea_0^2 by Roos et al. [Nature 443, 316 (2006)].Comment: 7 page

Rachis cracking in grapes

Studies on cracking of rachis of grapes have shown th at out of 87 cultivars under study, 16 were prone to it. Berry quality was not affected by the malady. Data on chemical composition of leaves suggested that the abnormality is not due to nutritional imbalance.Risse in TraubenstielenBei 16 von 87 untersuchten Rebensorten traten mehr oder weniger häufig Längsrisse in den Traubenstielen auf. Die Qualität der Beeren wurde durch die Erkrankung nicht beeinflußt. Aufgrund der Befunde über den Mineralstoffgehalt der Blätter ist zu vermuten, daß die Abnormität nicht durch eine unausgewogene Ernährung, sonde rn durch andere Faktoren verursacht wird