An Improved Rotary Mechanism Engine

Developments in the field of rotary engines have been reviewed. Potential of scissor action type rotary engine with suitable innovations on linkage and multirotor configuration has been brought out

An Efficacious and Secure Registration for Internet Protocol Mobility

For the ample development of mobile internet protocol (IP) technology and the recurrent movement of a mobile device, it is necessary for the mobile device to inform their home network where initially registered through an efficient and secured procedure against any sort of attacks. The procedure of registration for IP mobility by the portable system must have a better performance by providing a certain level of security, such as authentication, integrity, replay attack protection, and location privacy. All at once, the extreme security in the registration of IP mobility may cause long registration time, principally for real-time systems. This paper mainly deals with a balanced effort for secure and efficient registration procedure which gives better security and efficiency in terms of registration delay. The proposed work provides an easy and fast registration procedure and lessens the registration delay through the usage of an identity based authenticated key exchange scheme that eliminates expensive pairing operations. The proposed protocol is verified by using AVISPA tool. The performance evaluation reveals that the proposed protocol significantly outperforms the existing protocols in terms of the registration delay.Defence Science Journal, 2013, 63(5), pp.502-507, DOI:http://dx.doi.org/10.14429/dsj.63.400

Direct Imaging of Protein Organization in an Intact Bacterial Organelle Using High-Resolution Atomic Force Microscopy

The function of bioenergetic membranes is strongly influenced by the spatial arrangement of their constituent membrane proteins. Atomic force microscopy (AFM) can be used to probe protein organization at high resolution, allowing individual proteins to be identified. However, previous AFM studies of biological membranes have typically required that curved membranes are ruptured and flattened during sample preparation, with the possibility of disruption of the native protein arrangement or loss of proteins. Imaging native, curved membranes requires minimal tip–sample interaction in both lateral and vertical directions. Here, long-range tip–sample interactions are reduced by optimizing the imaging buffer. Tapping mode AFM with high-resonance-frequency small and soft cantilevers, in combination with a high-speed AFM, reduces the forces due to feedback error and enables application of an average imaging force of tens of piconewtons. Using this approach, we have imaged the membrane organization of intact vesicular bacterial photosynthetic “organelles”, chromatophores. Despite the highly curved nature of the chromatophore membrane and lack of direct support, the resolution was sufficient to identify the photosystem complexes and quantify their arrangement in the native state. Successive imaging showed the proteins remain surprisingly static, with minimal rotation or translation over several-minute time scales. High-order assemblies of RC-LH1-PufX complexes are observed, and intact ATPases are successfully imaged. The methods developed here are likely to be applicable to a broad range of protein-rich vesicles or curved membrane systems, which are an almost ubiquitous feature of native organelles

Nature of Correlated Motion of Electrons in the Parent Cobaltate Superconductors

Recently discovered class of cobaltate superconductors (Na0.3CoO2.nH2O) is a novel realization of interacting quantum electron systems in a triangular network with low-energy degrees of freedom. We employ angle-resolved photoemission spectroscopy to uncover the nature of microscopic electron motion in the parent superconductors for the first time. Results reveal a large hole-like Fermi surface (consistent with Luttinger theorem) generated by the crossing of super-heavy quasiparticles. The measured quasiparticle parameters collectively suggest a two orders of magnitude departure from the conventional Bardeen-Cooper-Schrieffer electron dynamics paradigm and unveils cobaltates as a rather hidden class of relatively high temperature superconductors.Comment: 5 pages, 4 figures, 1 tabl

Arithmetically Cohen-Macaulay Bundles on complete intersection varieties of sufficiently high multidegree

Recently it has been proved that any arithmetically Cohen-Macaulay (ACM) bundle of rank two on a general, smooth hypersurface of degree at least three and dimension at least four is a sum of line bundles. When the dimension of the hypersurface is three, a similar result is true provided the degree of the hypersurface is at least six. We extend these results to complete intersection subvarieties by proving that any ACM bundle of rank two on a general, smooth complete intersection subvariety of sufficiently high multi-degree and dimension at least four splits. We also obtain partial results in the case of threefolds.Comment: 15 page

Four-year assessment of ambient particulate matter and trace gases in the Delhi-NCR region of India

A key challenge in controlling Delhi’s air quality is a lack of clear understanding of the impacts of emissions from the surrounding National Capital Region (NCR). Our objectives are to understand the limitations of publicly available data, its utility to determine pollution sources across Delhi-NCR and establish seasonal profiles of chemically active trace gases. We obtained the spatiotemporal characteristics of daily-averaged particulate matter (PM10 and PM2.5) and trace gases (NOX, O3, SO2, and CO) within a network of 12 air quality monitoring stations located over 2000 km2 across Delhi-NCR from January 2014 to December 2017. The highest concentrations of pollutants, except O3, were found at Anand Vihar compared with lowest at Panchkula. A high homogeneity in PM2.5 was observed among Delhi sites as opposed to a high spatial divergence between Delhi and NCR sites. The bivariate polar plots and k-means clustering showed that PM2.5 and PM10 concentrations are dominated by local sources for all monitoring sites across Delhi-NCR. A consequence of the dominance of local source contributions to measured concentrations, except to one site remote from Delhi, is that it is not possible to evaluate the influence of regional pollution transport upon PM concentrations measured at sites within Delhi and the NCR from concentration measurements alone

Spatio temporal population dynamics of the invasive diatom Didymosphenia geminate in central-southern Chilean rivers

We document the distribution of Didymosphenia geminata in central-southern Chilean rivers and identify the chemical and physical factors associated with its presence/absence (p/a). Repeated surveys in five successive years provided evidence that D. geminata could be nearing a biogeographic equilibrium in the region. D. geminata databases from extensive biological and environmental surveys in 187 rivers,within ten catchments, south of 38°S commenced in November 2010 and ran through May 2013. In addition, data from two other field surveys were used. The sites evenly distributed latitudinally were climatically characterized. The recent sampling program, following a published species distribution model, was designed to explore D. geminata distribution within thirteen catchments (34°S–48°S). An extensive river survey in 2014 (spring-summer) and in 2015 (autumn) included the p/a, and relative abundance of D. geminata cells in phytobenthos and in the drift. These p/a results showed that the probability of re-encountering D. geminata cells at sites where the species was previously found was significantly highwhile the probability of finding D. geminata cells at sites previously without the species was significantly low. This suggests that the distribution of D. geminata cells among suitable habitats was nearing completion. The relative abundance of D. geminata cells in the phytobenthos versus in the drift indicates seasonality with higher proportion of cells in the phytobenthos during the spring-summer than during the autumn. During the final surveys, principal component analysis of chemical and physical characteristics of rivers showed significant differences between rivers with and without D. geminata. Based on our observations of the distribution of D. geminata cells among rivers with suitable habitat conditions and the fluctuating rate of spread between rivers,we conclude that D. geminata is probably in the ending stage of its spatial demographic expansion in Chile surmounting the different barriers of the invasive process

Amplitude measurements of Faraday waves

A light reflection technique is used to measure quantitatively the surface elevation of Faraday waves. The performed measurements cover a wide parameter range of driving frequencies and sample viscosities. In the capillary wave regime the bifurcation diagrams exhibit a frequency independent scaling proportional to the wavelength. We also provide numerical simulations of the full Navier-Stokes equations, which are in quantitative agreement up to supercritical drive amplitudes of 20%. The validity of an existing perturbation analysis is found to be limited to 2.5% overcriticaly.Comment: 7 figure

Neutrino Masses, Baryon Asymmetry, Dark Matter and the Moduli Problem : A Complete Framework

Recent developments in string theory have led to "realistic" string compactifications which lead to moduli stabilization while generating a hierarchy between the Electroweak and Planck scales at the same time. However, this seems to suggest a rethink of our standard notions of cosmological evolution after the end of inflation and before the beginning of BBN. We argue that within classes of realistic string compactifications, there generically exists a light modulus with a mass comparable to that of the gravitino which generates a large late-time entropy when it decays. Therefore, all known mechanisms of generating the baryon asymmetry of the Universe in the literature have to take this fact into account. In this work, we find that it is still possible to naturally generate the observed baryon asymmetry of the Universe as well as light left-handed neutrino masses from a period of Affleck-Dine(AD) leptogenesis shortly after the end of inflation, in classes of realistic string constructions with a minimal extension of the MSSM below the unification scale (consisting only of right-handed neutrinos) and satisfying certain microscopic criteria described in the text. The consequences are as follows. The lightest left-handed neutrino is required to be virtually massless. The moduli (gravitino) problem can be naturally solved in this framework both within gravity and gauge mediation. The observed upper bound on the relic abundance constrains the moduli-matter and moduli-gravitino couplings since the DM is produced non-thermally within this framework. Finally, although not a definite prediction, the framework naturally allows a light right-handed neutrino and sneutrinos around the electroweak scale which could have important implications for DM as well as the LHC.Comment: 41 pages, no figures, journal version adde

Workshop report: strategic planning workshop on recovering Banana production in BBTD affected areas: community and farm household approaches

Banana bunchy top disease (BBTD) caused by the Banana bunchy top virus (BBTV, genus Babuvirus, family Nanoviridae) renders plants unproductive and eventually kills affected plants. BBTD spreads into new fields along with infected planting material and through the banana aphid, Pentalonia nigronervosa, which is widespread in all banana and plantain-producing areas. BBTD was first reported from Africa in 1901, however, extensive spread into new production areas has been observed during the last two decades. The disease has very recently invaded Benin and Nigeria in West Africa in addition to limited spread within the Kivu provinces (Democratic Republic of Congo, DRC), neighbor to the largest banana-producing country in Africa - Uganda.Currently, Bunchy top has been recorded in 35 countries across Africa, Asia, Australia and the South Pacific Islands, including Hawaii (USA), but not in the Americas. In Africa, occurrence has been confirmed in 14 countries, namely Angola, Benin, Burundi, Cameroon, Central African Republic, Congo Republic, DRC, Egypt, Equatorial Guinea, Gabon, Malawi, Nigeria, Rwanda and Zambia