320 research outputs found
Lasing in Single Cadmium Sulfide Nanowire Optical Cavities
The mechanism of lasing in single cadmium sulfide (CdS) nanowire cavities was
elucidated by temperature-dependent and time-resolved photoluminescence (PL)
measurements. Temperature-dependent PL studies reveal rich spectral features
and show that an exciton-exciton interaction is critical to lasing up to 75 K,
while an exciton-phonon process dominates at higher temperatures. These
measurements together with temperature and intensity dependent life-time and
threshold studies suggest that lasing is due to formation of excitons, and
moreover, have implications for the design of efficient, low-threshold nanowire
lasers.Comment: 4 figure
Comparision of Iris Identification by Using modified SIFT and SURF keypoint Descriptor
A wide variety of systems require reliable personal recognition schemes to either confirm or determine the identity of an individual requesting their services. The purpose of such schemes is to ensure that only a legitimate user, access the rendered service. A biometrics system is essentially a pattern recognition system, which makes a personal identification by determining the authenticity of a specific physiological or behavioral characteristic possessed by the user. Iris serves as one of the excellent biometric traits due to the stability and randomness of its unique features. After localization of the iris, Scale Invariant Feature Transform (SIFT) is used to extract the local features. But SIFT is found out to be computational complex.So in this paper another keypoint descriptor ,Speeded Up Robust Features (SURF), is tested and then modified which compare the performance of different descriptor and hence gives promising results with very less computations. We finally carry out a comparision of both the descriptors performance wise
Severe sepsis due to severe falciparum malaria and leptospirosis co-infection treated with activated protein C
Co-infection with falciparum malaria and leptospirosis is uncommon. The aim of this study is to report a case of severe sepsis secondary to dual infection with falciparum malaria and leptospirosis. The literature is also reviewed on the clinical course of such co-infections, and the possible mechanisms and treatment of patients with life-threatening malaria and leptospirosis with activated protein C. The patient was a 25-year old male admitted in the Respiratory Intensive Care Unit (RICU) with fever, haemolysis, acute renal failure, hepatitis, acute lung injury (ALI) and altered sensorium. A syndromic evaluation was done and investigations revealed falciparum parasitaemia. He was treated with parenteral artesunate, ceftriaxone and doxycycline, and adjunctive therapies as for severe sepsis. Infusion of activated protein C was started 20 hours after onset of organ dysfunction, and intensive haemodialysis was instituted. Over the next four days the patient became afebrile with progressive resolution of ALI, renal failure and hepatitis. His Leptospira serology (requested as part of the evaluation) was reported positive on day 5. Dual infections are common and under-recognized in the tropics. Failure to treat potential co-infections may lead to poor outcomes. Acute lung injury in falciparum malaria has high mortality rates and therapy as for severe sepsis may improve survival. Adjunctive therapies, including activated protein C, cannot replace source eradication
Studies of hot photoluminescence in plasmonically-coupled silicon via variable energy excitation and temperature dependent spectroscopy
By coupling silicon nanowires (~150 nm diameter, 20 micron length) with an
{\Omega}-shaped plasmonic nanocavity we are able to generate broadband visible
luminescence, which is induced by high-order hybrid nanocavity-surface plasmon
modes. The nature of this super-bandgap emission is explored via
photoluminescence spectroscopy studies performed with variable laser excitation
energies (1.959 eV to 2.708 eV) and finite difference time domain simulations.
Furthermore, temperature-dependent photoluminescence spectroscopy shows that
the observed emission corresponds to radiative recombination of un-thermalized
(hot) carriers as opposed to a Resonant Raman process
A Real-Time Approach for Smart Building Operations Prediction Using Rule-Based Complex Event Processing and SPARQL Query
Due to intelligent, adaptive nature towards various operations and their
ability to provide maximum comfort to the occupants residing in them, smart
buildings are becoming a pioneering area of research. Since these architectures
leverage the Internet of Things (IoT), there is a need for monitoring different
operations (Occupancy, Humidity, Temperature, CO2, etc.) to provide sustainable
comfort to the occupants. This paper proposes a novel approach for intelligent
building operations monitoring using rule-based complex event processing and
query-based approaches for dynamically monitoring the different operations.
Siddhi is a complex event processing engine designed for handling multiple
sources of event data in real time and processing it according to predefined
rules using a decision tree. Since streaming data is dynamic in nature, to keep
track of different operations, we have converted the IoT data into an RDF
dataset. The RDF dataset is ingested to Apache Kafka for streaming purposes and
for stored data we have used the GraphDB tool that extracts information with
the help of SPARQL query. Consequently, the proposed approach is also evaluated
by deploying the large number of events through the Siddhi CEP engine and how
efficiently they are processed in terms of time. Apart from that, a risk
estimation scenario is also designed to generate alerts for end users in case
any of the smart building operations need immediate attention. The output is
visualized and monitored for the end user through a tableau dashboard
Manipulation and assembly of nanowires with holographic optical traps
We demonstrate that semiconductor nanowires measuring just a few nanometers
in diameter can be translated, rotated, cut, fused and organized into
nontrivial structures using holographic optical traps. The holographic approach
to nano-assembly allows for simultaneous independent manipulation of multiple
nanowires, including relative translation and relative rotation.Comment: 5 pages, 5 figure
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