35 research outputs found
Scanning Fourier Spectroscopy: A microwave analog study to image transmission paths in quantum dots
We use a microwave cavity to investigate the influence of a movable absorbing
center on the wave function of an open quantum dot. Our study shows that the
absorber acts as a position-selective probe, which may be used to suppress
those wave function states that exhibit an enhancement of their probability
density near the region where the impurity is located. For an experimental
probe of this wave function selection, we develop a technique that we refer to
as scanning Fourier spectroscopy, which allows us to identify, and map out, the
structure of the classical trajectories that are important for transmission
through the cavity.Comment: 4 pages, 5 figure
Tidal Evolution of Close Binary Asteroid Systems
We provide a generalized discussion of tidal evolution to arbitrary order in
the expansion of the gravitational potential between two spherical bodies of
any mass ratio. To accurately reproduce the tidal evolution of a system at
separations less than five times the radius of the larger primary component,
the tidal potential due to the presence of a smaller secondary component is
expanded in terms of Legendre polynomials to arbitrary order rather than
truncated at leading order as is typically done in studies of well-separated
system like the Earth and Moon. The equations of tidal evolution including
tidal torques, the changes in spin rates of the components, and the change in
semimajor axis (orbital separation) are then derived for binary asteroid
systems with circular and equatorial mutual orbits. Accounting for higher-order
terms in the tidal potential serves to speed up the tidal evolution of the
system leading to underestimates in the time rates of change of the spin rates,
semimajor axis, and mean motion in the mutual orbit if such corrections are
ignored. Special attention is given to the effect of close orbits on the
calculation of material properties of the components, in terms of the rigidity
and tidal dissipation function, based on the tidal evolution of the system. It
is found that accurate determinations of the physical parameters of the system,
e.g., densities, sizes, and current separation, are typically more important
than accounting for higher-order terms in the potential when calculating
material properties. In the scope of the long-term tidal evolution of the
semimajor axis and the component spin rates, correcting for close orbits is a
small effect, but for an instantaneous rate of change in spin rate, semimajor
axis, or mean motion, the close-orbit correction can be on the order of tens of
percent.Comment: 40 pages, 2 tables, 8 figure
Effect of Different Carbon Sources on In vitro Shoot Regeneration of Solanum nigrum (Linn) - An Important Antiulcer Medicinal Plant
An efficient in vitro protocol for mass propagation of Solanum nigrum was developed. In the present study, the effect of various carbon sources, sucrose, glucose, fructose, and maltose was investigated on in vitro shoot regeneration using nodal explants. The frequency, growth and multiplication rate were highly influenced by the type and concentration of carbon sources used. The highest number of shoots (24.0±0.28) were obtained on MS medium supplemented with 4% fructose, but maximum shoot length (11.0±0.28 cm) was observed on MS medium supplemented with 4% sucrose. The least number of shoots obtained on MS medium supplemented with 1% glucose (3.5±0.50), with a shoot length of (3.4±0.34 cm). Among the different carbon sources used in the present study, fructose at 4% proved to be better choice for multiple shoot regeneration followed by sucrose, maltose and glucose, from nodal explants of Solanum nigrum
Electrochemical impedance spectroscopic investigation on detection of H2S gas using 2D TiO2/rGO nano-composites
In the present work, gas sensor was fabricated using nano-Titanium Dioxide (n-TiO2) and nano-Titanium Dioxide/ Reduced Graphene Oxide composite (n-TiO2/rGO). This H2S (2 ppm) gas sensor was evaluated under different temperatures (Room temperature (27 °C) - 200 °C) and achieved the high response at room temperature. The n-TiO2/rGO-3 sensor is high response (RS=43) due to rGO is covered between n-TiO2 and works like a bridge between the adjoining n-TiO2 particles, these properties to increase the electron transfer and enhance the gas adsorption properties. Also sensor was highly selective towards H2S (2 ppm) compared with various gases (CO, NH3, SO2, and H2)., response and recovery (7 s and 10 s), its long-term stability upto 10 days was studied and it was more stable. The properties of the R1 (grain bulk), R2 (grain boundaries) and Q2 (electrode-sensing film contact) was analyzed by impedance with equivalent circuit. Grain boundaries results was highly changed under H2S gas environment and it was analyzed by equivalent circuit-fitted values
Design of Controller for Bidirectional Non-isolated High Gain Converter in EV Application
An interface between a DC supply and an electric vehicle's drive fed by an inverter is a bidirectional
DC-DC converter. In this research, a topology for an electric vehicle based on an induction motor that integrates
a high voltage gain bidirectional non-isolated DC/DC converter with a three-phase inverter is proposed. This
study compares a bidirectional DC to DC converter inverter system controlled by fuzzy logic (FL), and fractional
order proportional integral derivative (FOPID). The suggested converter runs in discontinuous-current mode
(DCM), with all switches and diodes switching at zero current. It is possible to operate across a wide duty cycle
range while maintaining high output voltage gain, low switching stress, minimal switching losses, and high
efficiency. The proposed converter's size and weight are decreased so as to support a wide range of duty cycle
operations, maintain lower voltage stress on all devices, ensure equal current sharing among inductors, are
simple to control, and require a more compact inductor. The converter also uses a constant input current which
offers a choice for various applications. MATLAB Simulink is used to construct, model, and simulate open loop
system, closed loop FL and FOPID. The results of these simulations are then reported. The investigations show
that FOPID controlled DC-DC converter performed better response
Biomineralization studies in age induced human teeth
Key Engineering Materials361-363 II893-896KEMA
Epidemiology of Vancomycin Resistant Enterococcus (VRE) in a Singapore Tertiary Hospital
Micro-assembled multi-chamber thermal cycler for low-cost reaction chip thermal multiplexing
10.1016/S0924-4247(02)00384-9Sensors and Actuators, A: Physical1021-2114-121SAAP
A Network Approach to Developing Immuno-Oncology Combinations in Canada
Immune checkpoint inhibitors have revolutionized care for many cancer indications, with considerable effort now being focused on increasing the rate, depth, and duration of patient response. One strategy is to combine immune strategies (for example, CTLA-4 and PD-1/L1–directed agents) to harness additive or synergistic efficacy while minimizing toxicity. Despite encouraging results with such combinations in multiple tumour types, numerous clinical challenges remain, including a lack of biomarkers that reliably predict outcome, the emergence of therapeutic resistance, and optimal management of immune-related toxicities. Furthermore, the selection of ideal combinations from the myriad of immune, systemic, and locoregional therapies has yet to be determined. A longitudinal network-based approach could offer advantages in addressing those critical questions, including long-term follow-up of patients beyond individual trials