564 research outputs found
Sensitivity analysis of a label-free detection using Opto-plasmonic nano-structured antenna
This paper reports a design method of optoplasmonics sensor that consider a pair of elliptical gold nano antenna mounted on a quartz substrate. A 2D array of gold nano antenna can be used for a variety of biomedical applications due to its key electronic and optical properties which are shape and size dependent. An elliptical shaped coupled gold nano antenna with 100 nm major axis, a and 10 nm minor axis, b was optimized with separation distance, g and height, h to achieve a high sensitivity with a narrow full-width half-maximum (FWHM) and a good figure of merit (FOM). By exploiting the resonance shift of transmission spectra and high electric field confinements, the sensitivity of the proposed sensor was obtained nearly 526-530 nm/RIU and the FWHM and FOM were calculated around 110 nm and 8.1, respectively. Additionally, the proposed sensing structure have been explored to measure the 2-propanol (IPA) concentration in water
Design and characterization of all-cryogenic low phase-noise sapphire K-band oscillator for sattelite communication
An all-cryogenic oscillator consisting of a frequency-tunable sapphire resonator, a high-temperature superconducting filter and a pseudomorphic high electron-mobility transistor amplifier was designed for the K-band frequency range and investigated. Due to the high quality factor of the resonator above 1000 000 and the low amplifier phase noise of approximately -133 dBc/Hz at a frequency offset of 1kHz from the carrier, we have achieved oscillator phase-noise values superior to quartz-stabilized oscillators at the same carrier frequency for offset frequencies higher than 100 Hz. In addition to, low phase noise, our prototype oscillator possesses mechanical and electrical frequency tunability. We have implemented a two-step electrical tuning arrangement consisting of a varactor phase shifter integrated within the amplifier circuit (fine tuning by 5'kHz) and a dielectric plunger moved by a piezomechanical transducer inside the resonator housing (course tuning by 50 kHz). This tuning range is sufficient for phase locking and for electronic compensation of temperature drifts occurring during operation of the device employing a miniaturized closed-cycle Stirling-type cryocooler
Deterministic cavity quantum electrodynamics with trapped ions
We have employed radio-frequency trapping to localize a single 40Ca+-ion in a high-finesse optical cavity. By means of laser Doppler cooling, the position spread of the ion's wavefunction along the cavity axis was reduced to 42 nm, a fraction of the resonance wavelength of ionized calcium (λ = 397 nm). By controlling the position of the ion in the optical field, continuous and completely deterministic coupling of ion and field was realized. The precise three-dimensional location of the ion in the cavity was measured by observing the fluorescent light emitted upon excitation in the cavity field. The single-ion system is ideally suited to implement cavity quantum electrodynamics under cw conditions. To this end we operate the cavity on the D3/2–P1/2 transition of 40Ca+ (λ = 866 nm). Applications include the controlled generation of single-photon pulses with high efficiency and two-ion quantum gates
First record of Bengal reticulated puffer Chelonodontops bengalensis (Tetraodontiformes: Tetraodontidae) from Odisha coast, north-western Bay of Bengal with taxonomic notes
The present study reports the first record of Bengal reticulated puffer, Chelonodontops bengalensis from Odisha coast in the north-western Bay of Bengal based on two specimens (226 – 301 mm SL), each collected from Paradeep and Bahabalpur in 2018 and 2019, respectively. The detailed morphological features of C. bengalensis are provided and compared with its previous records. The species is distinguished from its congeners by having 12 dorsal fin rays, 10 anal fin rays, 18 – 19 pectoral fin rays, 10 – 11 caudal fin rays, nasal organ cup shaped with unequal sized flaps, and dorsal profile of body covered with white spots of various shape and size and ventral side silvery white. Our study indicated the range extension of C. bengalensis from its known geographical range i.e. Bangladesh and West Bengal towards south in the northern Bay of Bengal
Morgagni hernia repair in children over two decades: Institutional experience, systematic review, and meta-analysis of 296 patients
BACKGROUND/PURPOSE: Morgagni diaphragmatic hernia (MH) is rare. We report our experience based on routine patch use in MH repair to curb recurrence. A systematic review and meta-analysis were performed to study the recurrence and complications associated with minimally invasive surgery and the use of patch. METHODS: We retrospectively reviewed all cases of MH who underwent first-time repair in 2012-2017 in our institution to determine recurrence and complication rate. A MEDLINE search related to minimally invasive surgery (MIS) and patch repair of MH was conducted for systematic review. Eligible articles published from 1997-2017 with follow-up data available were included. Primary outcomes measured were recurrence and complication. Meta-analysis to compare open versus MIS and primary versus patch repair in the MIS group were performed in comparative cohorts. Continuous data were presented as median (range), and statistical significance was P<0.05. RESULTS: In our institution, 12 consecutive patients aged 17-month-old (22 days-7 years), underwent laparoscopic patch repair of MH, with one conversion to laparotomy. No recurrence or significant complication occurred over a follow-up period of 8 months (1-48 months). Thirty-six articles were included from literature review and were combined with the current series. All were retrospective case reports or series, of which 6 were comparative cohorts with both MIS and open repairs. A total of 296 patients from 37 series were ultimately used for analysis: 80 had open repair (4 patch) and 216 had MIS repair (32 patch), with a patch rate of 12%. There were 13 recurrences (4%): no difference between open and MIS repairs (4/80 vs 9/216, p=0.75); recurrence rate following primary repair was 13/260 (5%), but no recurrence occurred with 36 patch repairs. Meta-analysis showed no difference in recurrence between open and MIS repair (p=0.83), whereas patch repair was associated with 14% less recurrence compared with primary repair, although it did not reach statistical significance (p=0.12). There were 13 complications (5%): no difference between open and MIS repairs (5/80 vs 8/216, p=0.35). One small bowel obstruction occurred in a patient who had laparoscopic patch repair. CONCLUSION: In MH, recurrence and complication rates are comparable between MIS and open repairs. Use of patch appeared to confer additional benefit in reducing recurrence. TYPE OF STUDY: Systematic review LEVEL OF EVIDENCE: 3A
Site amplification in the Kathmandu Valley during the 2015 M7.6 Gorkha, Nepal earthquake
The 25th April 2015 M7.6 Gorkha earthquake caused significant damage to
buildings and infrastructure in both Kathmandu and surrounding areas as well as triggering
numerous, large landslides. This resulted in the loss of approximately 8600 lives. In order
to learn how the impact of such events can be reduced on communities both in Nepal and
elsewhere, the Earthquake Engineering Field Investigation Team (EEFIT) reconnaissance
mission was undertaken, aiming to look at damage patterns within the country. Passive,
microtremor recordings in severely damaged areas of the Kathmandu Valley, as well as at
the main seismic recording station in Kathmandu (USGS station KATNP) are used to
determined preliminary shear wave velocity (Vs) profiles for each site. These profiles are
converted into spectral acceleration using the input motion of the Gorkha earthquake. The
results are limited, but show clear site amplification within the Siddhitol Region. The
resulting ground motions exceed the design levels from the Nepalese Building Codes,
indicating the need for site-specific hazard analysis and for revision of the building code to
address the effect of site amplificatio
The Sasa-Satsuma higher order nonlinear Schrodinger equation and its bilinearization and multi-soliton solutions
Higher order and multicomponent generalizations of the nonlinear Schrodinger
equation are important in various applications, e.g., in optics. One of these
equations, the integrable Sasa-Satsuma equation, has particularly interesting
soliton solutions. Unfortunately the construction of multi-soliton solutions to
this equation presents difficulties due to its complicated bilinearization. We
discuss briefly some previous attempts and then give the correct
bilinearization based on the interpretation of the Sasa-Satsuma equation as a
reduction of the three-component Kadomtsev-Petvishvili hierarchy. In the
process we also get bilinearizations and multi-soliton formulae for a two
component generalization of the Sasa-Satsuma equation (the
Yajima-Oikawa-Tasgal-Potasek model), and for a (2+1)-dimensional
generalization.Comment: 13 pages in RevTex, added reference
Saving behaviour and health: A high-dimensional Bayesian analysis of British panel data
We develop a two-part high-dimensional Bayesian modelling approach to analyse the relationship between saving behaviour and health. In contrast to the existing literature, our approach allows different data-generating processes for the decision to save and the amount saved, and therefore unveils a more detailed picture of the relationship between financial behaviour and health than previous work. We explore different measures of saving, including monthly saving behaviour and the stock of financial assets held. Further, we exploit British panel data, which includes an extensive range of biomarkers. Our second contribution lies in comparing the effects of these objective measures of health with commonly used self-assessed health measures. We find that health is a significant determinant of saving behaviour and financial asset holding, and that biomarker measures have differential impacts on saving behaviour compared to self-reported health measures
Collective oscillations of a 1D trapped Bose gas
Starting from the hydrodynamic equations of superfluids, we calculate the
frequencies of the collective oscillations of a harmonically trapped Bose gas
for various 1D configurations. These include the mean field regime described by
Gross-Pitaevskii theory and the beyond mean field regime at small densities
described by Lieb-Liniger theory. The relevant combinations of the physical
parameters governing the transition between the different regimes are
discussed.Comment: 4 pages, 2 figure
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