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Electrowetting-on-Dielectric Tunable Optics for Laser Scanners and Whispering Gallery Mode Resonator
Formed by a balance between surface tension and Laplace pressure, liquids have an extremely smooth interface (Angstrom roughness) which are ideal for photonic applications. This work utilizes the electrowetting-on-dielectric effect to manipulate the liquid interface by altering the surface wettability. The liquid interface can be used as a tunable lens, prism for beam steering, or generate complex wavefronts for aberration correction. I investigated a cylindrical laser scanner and a liquid whispering gallery mode (WGM) optical resonator. With the goal of improving the performance of an electrowetting laser scanner, a new set of high refractive index contrast liquids (deionized water pair with 1-phenyl-1-cyclohexene) is selected. The liquids feature a high refractive index contrast (Δn=0.24), similar density (Δρ<4 kg/m3), large sidewall contact angle tuning range (113°), and beam scanning frequencies (> 800 Hz) in a millimeter scale device. Scanning characteristics of the liquid system is characterized and a calibration algorithm is introduced to compensate for the optical distortion caused by the radial scanning method and fabrication variations. Additionally, axisymmetrical resonance modes along the liquid-liquid interface are modeled as a first step towards understanding the effects of external vibrations on an electrowetting device. Lastly, a new on chip platform for liquid whispering gallery mode (WGM) optical resonators is introduced. The platform is fabricated using standard semiconductor techniques, paving a path forward towards the integration of photonic components with liquid WGM resonators. Embedded electrodes enabled the tuning of the geometry of the droplet which redshifts the resonance frequency (1.44 nm). High quality-factors (Q-factor) resonances of 105 are achieved, demonstrating the potential for liquid resonators for sensing and nonlinear optical effects.</p
Effects of design parameters on sensitivity of microcantilever biosensors
Microcantilever biosensors produce cantilever bending due to differential surface stress between upper and lower surfaces of the cantilever. The bending is associated with concentration of ligands and adsorbed ligand-receptor intermolecular forces. Sample volume sizes in clinical diagnostic applications are usually very minute requiring a highly sensitive microcantilever for disease detection. This paper investigates a number of parameters that influence the sensitivity of microcantilever biosensors. The parameters include length, thickness, shape, and material of the cantilever beam. Biosensors of varying parameters are modeled and simulated. The results show that increasing the length of the cantilever beam enhances its sensitivity. However, increasing the thickness of the cantilever beam reduces its sensitivity. In static analysis, the shape of the cantilever beam does not notably impact upon its sensitivity. Also, using materials with lower Young’s modulus improves the sensitivity.<br /
Radio astronomy interferometer network testing for a Malaysia-China real-time e-VLBI
The uv-coverage of the current VLBI network between Australia northern Asia will be significantly enhanced with an existence of a middle baseline VLBI station located in Malaysia. This paper investigated the connecting route of the first half of the Asia-Oceania VLBI network i.e. from Malaysia to China. The investigation of transmission network characteristics between Malaysia and China was carried out in order to perform a real-time and reliable data transfer within the e-VLBI network for future eVLBI observations. MyREN (Malaysia) and CSTNET (China) high-speed research networks were utilized for this proposed e-VLBI connection. Preliminary network test was performed by ping, traceroute, and iperf prior to data transfer tests, which were evaluated with three types of protocols namely FTP, Tsunami-UDT and UDT. The results showed that, on average, there were eighteen hops between Malaysia and China networks with 98 ms round trip time (RTT) delay. Overall UDP protocol has a better throughput compared to TCP protocol. UDP can reach a maximum rate of 90 Mbps with 0% packet loss. In this feasibility test, the VLBI test data was successfully transferred between Malaysia and China by utilizing the three types of data transfer protocols
Towards Green Metaverse Networking Technologies, Advancements and Future Directions
As the Metaverse is iteratively being defined, its potential to unleash the
next wave of digital disruption and create real-life value becomes increasingly
clear. With distinctive features of immersive experience, simultaneous
interactivity, and user agency, the Metaverse has the capability to transform
all walks of life. However, the enabling technologies of the Metaverse, i.e.,
digital twin, artificial intelligence, blockchain, and extended reality, are
known to be energy-hungry, therefore raising concerns about the sustainability
of its large-scale deployment and development. This article proposes Green
Metaverse Networking for the first time to optimize energy efficiencies of all
network components for Metaverse sustainable development. We first analyze
energy consumption, efficiency, and sustainability of energy-intensive
technologies in the Metaverse. Next, focusing on computation and networking, we
present major advancements related to energy efficiency and their integration
into the Metaverse. A case study of energy conservation by incorporating
semantic communication and stochastic resource allocation in the Metaverse is
presented. Finally, we outline the critical challenges of Metaverse sustainable
development, thereby indicating potential directions of future research towards
the green Metaverse
Analysis and modeling of ASIC area at early-stage design for standard cell library selection
Area-delay curve is an effective technique to compare and select the appropriate library at different target delay constraint. However, generating area-delay curve requires time-consuming synthesis processes. This paper presents a fast area estimation model to allow the designer to select the optimal library for designing area-optimized circuit. The model predicts the area-delay curves for a target circuit based on reduced number of synthesis performed at different frequencies. As compared to the general linear search method, the proposed model with 5 synthesis points results 16.5X-18.6X runtime reduction with average error of 2.74%~5.74% in different height libraries implementation. This shows that the proposed model is beneficial for area optimal library selection at the early stage of design
Full-sky ray-tracing simulation of weak lensing using ELUCID simulations: exploring galaxy intrinsic alignment and cosmic shear correlations
The intrinsic alignment of galaxies is an important systematic effect in
weak-lensing surveys, which can affect the derived cosmological parameters. One
direct way to distinguish different alignment models and quantify their effects
on the measurement is to produce mocked weak-lensing surveys. In this work, we
use full-sky ray-tracing technique to produce mock images of galaxies from the
ELUCID -body simulation run with the WMAP9 cosmology. In our model we assume
that the shape of central elliptical galaxy follows that of the dark matter
halo, and spiral galaxy follows the halo spin. Using the mocked galaxy images,
a combination of galaxy intrinsic shape and the gravitational shear, we compare
the predicted tomographic shear correlations to the results of KiDS and DLS. It
is found that our predictions stay between the KiDS and DLS results. We rule
out a model in which the satellite galaxies are radially aligned with the
center galaxy, otherwise the shear-correlations on small scales are too high.
Most important, we find that although the intrinsic alignment of spiral
galaxies is very weak, they induce a positive correlation between the
gravitational shear signal and the intrinsic galaxy orientation (GI). This is
because the spiral galaxy is tangentially aligned with the nearby large-scale
overdensity, contrary to the radial alignment of elliptical galaxy. Our results
explain the origin of detected positive GI term from the weak-lensing surveys.
We conclude that in future analysis, the GI model must include the dependence
on galaxy types in more detail.Comment: 23 pages, 13 figures, published in ApJ. Our mock galaxy catalog is
available upon request by email to the author ([email protected],
[email protected]
Functional Antagonism of WRI1 and TCP20 Modulates \u3ci\u3eGH3.3\u3c/i\u3e Expression to Maintain Auxin Homeostasis in Roots
Auxin is a well-studied phytohormone, vital for diverse plant developmental processes. The GH3 genes are one of the major auxin responsive genes, whose expression changes lead to modulation of plant development and auxin homeostasis. However, the transcriptional regulation of these GH3 genes remains largely unknown. WRI1 is an essential transcriptional regulator governing plant fatty acid biosynthesis. Recently, we identified that the expression of GH3.3 is increased in the roots of wri1-1 mutant. Nevertheless, in this study we found that AtWRI1 did not activate or repress the promoter of GH3.3 (proGH3.3) despite of its binding to proGH3.3. Cross-family transcription factor interactions play pivotal roles in plant gene regulatory networks. To explore the molecular mechanism by which WRI1 controls GH3.3 expression, we screened an Arabidopsis transcription factor library and identified TCP20 as a novel AtWRI1-interacting regulator. The interaction between AtWRI1 and TCP20 was further verified by several approaches. Importantly, we found that TCP20 directly regulates GH3.3 expression via binding to TCP binding element. Furthermore, AtWRI1 repressed the TCP20-mediated transactivation of proGH3.3. EMSAs demonstrated that AtWRI1 antagonized TCP20 from binding to proGH3.3. Collectively, we provide new insights that WRI1 attenuates GH3.3 expression through interaction with TCP20, highlighting a new mechanism that contributes to fine-tuning auxin homeostasis
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