Traffic management for drones flying in the city

Air Traffic Management (ATM) is designed based on the notion of a pilot navigating an aircraft from within the aircraft. Increasing demand for Unmanned Aircraft Systems (UAS) usage and its safe integration into segregated/non-segregated airspace, on the other hand, have raised a question on the adoption of the current ATM for the UAS Traffic Management (UTM). The Procedures for Air Navigation Services-Air Traffic Management (PAN-ATM) and Procedures for Air Navigation Services - aircraft operations (PAN-OPS) rules are both developed for manned flight operations. Therefore, this work (i) defines the UTM system and describes its envisioned functionalities; (ii) performs an exploratory research to identify the distinctions between a manned and an unmanned flight operations and consequently the possible challenges to implement UTM with regard to the ATM; (iii) determines potential Communication, Navigation and Surveillance (CNS) technologies to support the UTM system; and proposes an architectural framework for UTM based on the findings. It is important to highlight that this work is developed based on the assumption that the UAS is remotely - piloted and operates in the class G airspace (500 feet and below) in urban areas where the UAS are exposed to various obstacles such as static objects: high-rise buildings, trees, lamp posts, over-ground rail tracks and dynamic objects: cranes

A STUDY ON MECHANICAL AND TRIBOLOGICAL PROPERTIES OF ALUMINIUM 7075 MMCS REINFORCED WITH NANO SILICON CARBIDE (SIC), TUR HUSK AND E-GLASS FIBER

Aluminium alloy materials found to be the best alternative with its unique capacity of designing the material to give required properties. Aluminium alloy metal matrix composites (MMCs) are gaining wide spread acceptance for automobile, industrial and aerospace application because of their low density, high strength and good structural rigidity. In the present work, an attempt is made to prepare and studies the mechanical and tribological properties of Al-7075 Reinforced with Nano SiC, Tur Husk and E-Glass fiber. The Al-7075 composites were fabricated by liquid metallurgy (stir cast) method by varying different percentages. The composite specimens were machined as per ASTM test standards. It has been observed that addition of Nano SiC, Tur Husk and E-Glass fiber significantly improves ultimate tensile strength along with compressive strength and hardness properties as compared with that of unreinforced matrix. The reinforcement is varied in 3 sets each set comprises of 3 specimens. Nano SiC is kept constant [1% in 1St set, 2% in 2nd set and 3% in 3rd set], tur husk and glass fiber are varied in 1% and 2% in all specimens. The casted composite specimens were machined as per ASTM standards. The mechanical properties like ultimate tensile strength, impact strength and wear behavior of the test specimens were investigated

Closed form solution of nonlinear oscillation of a cantilever beam using λ-symmetry linearization criteria

A mechanical system, in general, undergoes vibrational motion when the system is subjected to a tension or an external force. One of the examples of such a system is a cantilever beam when it is exposed to a bending action. When the tension is released, the cantilever beam suffers from the oscillations until the strain energy is totally released through the damping characteristics of the cantilever beam. Depending on the stiffness and damping factors of the beam, the vibrational motion can be non-linear; in which case, the analytical solution becomes challenging formulating the flexural characteristics of the beam. Although numerical solution for the non-linear problem is possible, the analytical solution provides useful information between the mechanical response and the cantilever beam characteristics. In the present study, the analytical solution of the non-linear equations governing the motion of the cantilever beam is presented. The governing equation is linearized incorporating the Lie-Tresse linearization method. The closed form solution for the displacement of the cantilever beam is reduced to a linear solution after introducing the appropriate beam characteristics. The dynamic behavior of the flexural motion due to non-linear and linear cantilever beams are compared.The open Access funding of this article is provided by Qatar National Library. The authors are thankful to Qatar University and King Fahd University of Petroleum and Minerals for their continuous support and excellent research facilities

Fluxes in M-theory on 7-manifolds and G structures

We consider warp compactifications of M-theory on 7-manifolds in the presence of 4-form fluxes and investigate the constraints imposed by supersymmetry. As long as the 7-manifold supports only one Killing spinor we infer from the Killing spinor equations that non-trivial 4-form fluxes will necessarily curve the external 4-dimensional space. On the other hand, if the 7-manifold has at least two Killing spinors, there is a non-trivial Killing vector yielding a reduction of the 7-manifold to a 6-manifold and we confirm that 4-form fluxes can be incorporated if one includes non-trivial SU(3) structures.Comment: 13 pages, Latex; minor changes & add reference

CRISPR/Cas9 mutagenesis by translocation of Cas9 protein into plant cells via the Agrobacterium type IV secretion system

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) is a powerful tool for genome engineering in plants. The RNAguided Cas9 endonuclease is usually delivered into plant cells as a DNA construct encoding Cas9 and the single guide RNA (sgRNA). However, constitutive expression of nucleases may cause off target mutations. In addition, DNA constructs can integrate into the host genome, causing mutations and complicating regulatory approval. Instead of DNA, here we deliver Cas9 through the Agrobacterium T4SS, accomplished by fusion of the VirF T4SS translocation peptide to Cas9 (NCas9F). Co-cultivation of Agrobacteria expressing NCas9F with yeast (Saccharomyces cerevisiae) harboring a sgRNA targeting CAN1 showed that NCas9F was translocated via T4SS and induced targeted mutations in the yeast genome. Infiltration of Nicotiana benthamiana leaves with Agrobacteria expressing NCas9F and sgRNA-PHYTOENE DESATURASE (PDS) resulted in targeted modifications at the PDS locus, albeit at a very low rate. In order to increase the mutation frequency NCas9F protein was co-transported with a TDNA encoding sgRNA-PDS1. Next generation sequencing confirmed that this resulted in targeted mutations at the PDS locus with a similar distribution but at a 5-fold lower frequency as the mutations obtained with a T-DNA encoding both Cas9 and sgRNA-PDS1. Similarly, infection with Tobacco rattle virus (TRV) encoding sgRNA-PDS2 combined with NCas9F protein translocation resulted in an equally high frequency of PDS mutations in N. benthamiana compared to T-DNA encoded sgRNA-PDS1 combined with NCas9F protein translocation. Our results revealed that translocation of NCas9F protein via the Agrobacterium T4SS can be used for targeted mutagenesis in host cells instead of the permanent and constitutive expression of Cas9 from a T-DNA.Plant science

Supercoherent States, Super K\"ahler Geometry and Geometric Quantization

Generalized coherent states provide a means of connecting square integrable representations of a semi-simple Lie group with the symplectic geometry of some of its homogeneous spaces. In the first part of the present work this point of view is extended to the supersymmetric context, through the study of the OSp(2/2) coherent states. These are explicitly constructed starting from the known abstract typical and atypical representations of osp(2/2). Their underlying geometries turn out to be those of supersymplectic OSp(2/2) homogeneous spaces. Moment maps identifying the latter with coadjoint orbits of OSp(2/2) are exhibited via Berezin's symbols. When considered within Rothstein's general paradigm, these results lead to a natural general definition of a super K\"ahler supermanifold, the supergeometry of which is determined in terms of the usual geometry of holomorphic Hermitian vector bundles over K\"ahler manifolds. In particular, the supergeometry of the above orbits is interpreted in terms of the geometry of Einstein-Hermitian vector bundles. In the second part, an extension of the full geometric quantization procedure is applied to the same coadjoint orbits. Thanks to the super K\"ahler character of the latter, this procedure leads to explicit super unitary irreducible representations of OSp(2/2) in super Hilbert spaces of $L^2$ superholomorphic sections of prequantum bundles of the Kostant type. This work lays the foundations of a program aimed at classifying Lie supergroups' coadjoint orbits and their associated irreducible representations, ultimately leading to harmonic superanalysis. For this purpose a set of consistent conventions is exhibited.Comment: 53 pages, AMS-LaTeX (or LaTeX+AMSfonts

Development and annotation of perennial Triticeae ESTs and SSR markers.

Triticeae contains hundreds of species of both annual and perennial types. Although substantial genomic tools are available for annual Triticeae cereals such as wheat and barley, the perennial Triticeae lack sufficient genomic resources for genetic mapping or diversity research. To increase the amount of sequence information available in the perennial Triticeae, three expressed sequence tag (EST) libraries were developed and annotated for Pseudoroegneria spicata, a mixture of both Elymus wawawaiensis and E. lanceolatus, and a Leymus cinereus x L. triticoides interspecific hybrid. The ESTs were combined into unigene sets of 8 780 unigenes for P. spicata, 11 281 unigenes for Leymus, and 7 212 unigenes for Elymus. Unigenes were annotated based on putative orthology to genes from rice, wheat, barley, other Poaceae, Arabidopsis, and the non-redundant database of the NCBI. Simple sequence repeat (SSR) markers were developed, tested for amplification and polymorphism, and aligned to the rice genome. Leymus EST markers homologous to rice chromosome 2 genes were syntenous on Leymus homeologous groups 6a and 6b (previously 1b), demonstrating promise for in silico comparative mapping. All ESTs and SSR markers are available on an EST information management and annotation database (http://titan.biotec.uiuc.edu/triticeae/)

Preparation and Characterization of Metformin Hydrochloride — Compritol 888 ATO Solid Dispersion

Metformin hydrochloride (MET) sustained-release solid dispersions (SD) were prepared by the solvent evaporation and closed melt method, using compritol 888 ATO as the polymer with five different drug-carrier ratios. Characterization of solid dispersion was carried out by Fourier Transform Infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD). The FTIR and UV studies suggested that no bond formation had occurred between the polymer and the drug. DSC and XPRD results ruled out any interaction or complex formation between the drug and the polymer. The formulated SD had acceptable physicochemical characters and SD with a 1 : 4 drug : Polymer ratio, which released the drug over an extended period of eight-to-ten hours. The data obtained from the in vitro release studies were fitted with various kinetic models and were found to follow the Korsmeyer-Peppas equation. The prepared SD showed good stability over the studied time period. The solvent evaporation method was found to be more helpful than the closed melt method, giving the sustained release action. The SD with a 1 : 4 ratio of drug to polymer, by the solvent evaporation method, was selected as the most effective candidate for the subsequent development of a well-timed, sustained-release dosage form of the drug

Measurement of the Branching Fraction for B->eta' K and Search for B->eta'pi+

We report measurements for two-body charmless B decays with an eta' meson in the final state. Using 11.1X10^6 BBbar pairs collected with the Belle detector, we find BF(B^+ ->eta'K^+)=(79^+12_-11 +-9)x10^-6 and BF(B^0 -> eta'K^0)=(55^+19_-16 +-8)x10^-6, where the first and second errors are statistical and systematic, respectively. No signal is observed in the mode B^+ -> eta' pi^+, and we set a 90% confidence level upper limit of BF(B^+-> eta'pi^+) eta'K^+- decays is investigated and a limit at 90% confidence level of -0.20<Acp<0.32 is obtained.Comment: Submitted to Physics Letters