15,291 research outputs found
Design and Development of an Airblast Atomiser for the KAVERI engine and the sectoral combustor tests
This report deals with the design and development
of an airblast atomiser for application in the KAVERI
engine. Five atomisers of the chosen design were
fabricated and tested at ambient conditions to determine
the fuel spray SMD, patternation, cone angle
and atomiser flow number. The atomiser performance
parameters specified were achieved and hot tests
carried out in the 90° combustor sector. The combustor
pressure loss, exit temperature distribution, ignition
and stability limits were evaluate
Plasmid-Encoded Multidrug Resistance of Salmonella typhi and some Enteric Bacteria in and around Kolkata, India: A Preliminary Study
The present study investigates the occurrence of R-plasmid in Salmonella typhi isolates from enteric fever cases in and around Kolkata (1991-2001), India following in vitro conjugation experiments, isolation of plasmid DNAs and agarose gel electrophoretic analysis. The multidrug resistant (MDR) S. typhi strains contained a transferable plasmid conferring resistance to ampicillin, chloramphenicol, cotrimoxazole and tetracycline. The plasmid encoding ACCoT-resistance of Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris were conjugative and co-migrated with the plasmid of MDR S. typhi isolates. The antibiotic sensitive S. typhi isolates did not contain any plasmid. Thus the findings of the present study confirmed the instability of the R-plasmid in S. typhi, and that the antibiotic sensitive S. typhi strains acquired the R-plasmid from other enteric bacteria such as E. coli, K. pneumoniae and P.vulgaris to undergo a suitable adaptation for survival in the changing antibiotic environment
Development and Wind Tunnel Evaluation of a SMA Based Trim Tab Actuator for a Civil Aircraft
This paper presents about the development and wind tunnel evaluation of an SMA based smart trim tab for a typical 2
seater civil aircraft. SMA actuator was housed in the port side of the elevator for actuating the trim tab. Wind tunnel tests were
conducted on a full scale Horizontal Tail model with Elevator and Trim Tab at free stream speeds of 25, 35 & 45 m/sec and also
for a number of deflections of the elevator (30° up, 0° neutral & 25° down) and trim-tab 11° & 21° up and 15° & 31° down). To
measure the hinge moment experienced by the trim-tab at various test conditions, two miniaturized balances were designed and
fabricated. Gain scheduled proportional integral controller was developed to control the SMA actuated smart trim tab. It was
confirmed during the tests that the trim-tab could be controlled at the desired position against the aerodynamic loads acting on it
for the various test conditions
Measurement of marine productivity using 15N and 13C tracers: Some methodological aspects
Various experiments involving the measurement of new, regenerated and total productivity using 15N and 13C tracers were carried out in the Bay of Bengal (BOB) and in the Arabian Sea. Results from 15N tracer experiments indicate that nitrate uptake can be underestimated by experiments with incubation time <4 hours. Indirect evidence suggests pico- and nano-phytoplankton, on their dominance over microphytoplankton, can also influence the f-ratios. Difference in energy requirement for assimilation of different nitrogen compounds decides the preferred nitrogen source during the early hours of incubation. Variation in light intensity during incubation also plays a significant role in the assimilation of nitrogen. Results from time course experiments with both 15N and 13C tracers suggest that photoinhibition appears significant in BOB and the Arabian Sea during noon. A significant correlation has been found in the productivity values obtained using 15N and 13C tracers
Mechanistic Modeling of Microtopographic Impacts on CO2 and CH4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model
Spatial heterogeneities in soil hydrology have been confirmed as a key control on CO2 and CH4 fluxes in the Arctic tundra ecosystem. In this study, we applied a mechanistic ecosystem model, CLM-Microbe, to examine the microtopographic impacts on CO2 and CH4 fluxes across seven landscape types in Utqiaġvik, Alaska: trough, low-centered polygon (LCP) center, LCP transition, LCP rim, high-centered polygon (HCP) center, HCP transition, and HCP rim. We first validated the CLM-Microbe model against static-chamber measured CO2 and CH4 fluxes in 2013 for three landscape types: trough, LCP center, and LCP rim. Model application showed that low-elevation and thus wetter landscape types (i.e., trough, transitions, and LCP center) had larger CH4 emissions rates with greater seasonal variations than high-elevation and drier landscape types (rims and HCP center). Sensitivity analysis indicated that substrate availability for methanogenesis (acetate, CO2 + H2) is the most important factor determining CH4 emission, and vegetation physiological properties largely affect the net ecosystem carbon exchange and ecosystem respiration in Arctic tundra ecosystems. Modeled CH4 emissions for different microtopographic features were upscaled to the eddy covariance (EC) domain with an area-weighted approach before validation against EC-measured CH4 fluxes. The model underestimated the EC-measured CH4 flux by 20% and 25% at daily and hourly time steps, suggesting the importance of the time step in reporting CH4 flux. The strong microtopographic impacts on CO2 and CH4 fluxes call for a model-data integration framework for better understanding and predicting carbon flux in the highly heterogeneous Arctic landscape
Li-Fi Based Helping Stick
Li-Fi stands for Light Fidelity that is transmitting data through visible light. Li-Fi is a 5th Generation Communication system of Visible Light having a light-emitting diodes as a medium to high-speed communication as that in a Wi-Fi. In the days where internet has become a major demand, people are in a search for Wi-Fi hotspots. The main idea of the paper is to create internal navigation systems for the bigger areas to create automatic navigation for the visually impaired using Li-Fi technology, as visible light is present everywhere
Moduli Stacks of Vector Bundles and Frobenius Morphisms
We describe the action of the different Frobenius morphisms on the cohomology
ring of the moduli stack of algebraic vector bundles of fixed rank and
determinant on an algebraic curve over a finite field in characteristic p and
analyse special situations like vector bundles on the projective line and
relations with infinite Grassmannians.Comment: 19 page
My Kid : An Android Based Child Tracking System
Child tracking system is extensively used across the world to insure parents that their wards are safe from dubious actions and their child is happy in school atmosphere without crying. The child module includes ARM7 microcontroller (lpc 2148), Global positioning system (GPS), Global system for mobile communication (GSM), Voice playback and the receiver component includes Android mobile device in parent#39s hand and the other as monitoring database in control room of the school. The proposed system includesnbsp monitoring of nbspthe child#39s movement to and from school. The info pertaining to missed child is sent to their respective parents. Not only the information about the child#39s whereabouts but also whether the child is crying is sent to parents through text message to their Android mobile device
Signal Propagation in Feedforward Neuronal Networks with Unreliable Synapses
In this paper, we systematically investigate both the synfire propagation and
firing rate propagation in feedforward neuronal network coupled in an
all-to-all fashion. In contrast to most earlier work, where only reliable
synaptic connections are considered, we mainly examine the effects of
unreliable synapses on both types of neural activity propagation in this work.
We first study networks composed of purely excitatory neurons. Our results show
that both the successful transmission probability and excitatory synaptic
strength largely influence the propagation of these two types of neural
activities, and better tuning of these synaptic parameters makes the considered
network support stable signal propagation. It is also found that noise has
significant but different impacts on these two types of propagation. The
additive Gaussian white noise has the tendency to reduce the precision of the
synfire activity, whereas noise with appropriate intensity can enhance the
performance of firing rate propagation. Further simulations indicate that the
propagation dynamics of the considered neuronal network is not simply
determined by the average amount of received neurotransmitter for each neuron
in a time instant, but also largely influenced by the stochastic effect of
neurotransmitter release. Second, we compare our results with those obtained in
corresponding feedforward neuronal networks connected with reliable synapses
but in a random coupling fashion. We confirm that some differences can be
observed in these two different feedforward neuronal network models. Finally,
we study the signal propagation in feedforward neuronal networks consisting of
both excitatory and inhibitory neurons, and demonstrate that inhibition also
plays an important role in signal propagation in the considered networks.Comment: 33pages, 16 figures; Journal of Computational Neuroscience
(published
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