An eight-channel add-drop cross-grid vertically coupled microring resonator (VCMRR) filter is proposed and demonstrated. The cross grid comprises a grid-like array of buried channel waveguides which ...perpendicularly cross through each other, VCMRRs at each of the cross-grid nodes serve as the wavelength selective add-drop filters. Measured crosstalk levels at the crossings are typically less than -30 dB. Rings with a nominal radius of 10 μm are used to achieve a free-spectral range of 20 nm and optical bandwidths of 1 nm, while changes of the radii in increments of 50 nm lead to a nominal channel spacing of 5.7 nm.
Ring resonators are coupled in parallel in order to obtain a second order type of wavelength response. The phase relationship between the rings determines the details of the spectral response. The ...rings used in the experiment have radii of 25 μm and are fabricated from compound glass having an index of 1.539. Several resonances are observed to have double peaked box-like response.
PJ.M. Otero, G. Panagiotou, L. Olsson: Fueling Industrial Biotechnology Growth with Bioethanol.- M. Galbe, G. Zacchi: Pretreatment of Lignocellulosic Materials for Efficient Bioethanol Production.- ...R.P. Chandra, R. Bura, W.E. Mabee, A. Berlin, X. Pan, J.N. Saddler: Substrate Pretreatment: The Key to Effective Enzymatic Hydrolysis of Lignocellulosics?- S.T. Merino, J. Cherry: Progress and Challenges in Enzyme Development of Biomass Utilization.- L. Viikari, M. Alapuranen, T. Puranen, J. Vehmaanper¿M. Siika-aho: Thermostable Enzymes in Lignocellulose Hydrolysis.- B. Hahn-H¿rdal, K. Karhumaa, M. Jeppsson, M.F. Gorwa-Grauslund: Metabolic Engineering for Pentose Utilization in Saccharomyces cerevisiae.- A.J.A. van Maris, A.A. Winkler, M. Kuyper, W.T.A.M. de Laat, J.P. van Dijken, J.T. Pronk: Development of Efficient Xylose Fermentation in Saccharomyces cerevisiae: Xylose Isomerase as a Key Component.- W.H. van Zyl, L.R. Lynd, R.den Haan, J.E. McBride: Consolidated Bioprocessing for Bioethanol Production Using Saccharomyces cerevisiae.- L.R. Jarboe, T.B. Grabar, L.P. Yomano, K.T. Shammugan, L.O. Ingram: Development of Ethanologenic Bacteria.- P.L. Rogers, Y.J. Jeon, K.J. Lee, G.G. Lawford: Zymomonas mobilis for Fuel Ethanol and Higher Value Products.- B.K. Ahring, P. Westermann: Coproduction of Bioethanol with Other Biofuels.- M. Galbe, P. Sassner, A. Wingren, G. Zacchi: Process Engineering Economics of Bioethanol Production.- W.E. Mabee: Policy Options to Support Biofuel Production./P
On 17 August 2017, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of the binary neutron star gravitational wave event GW170817. We report time-series spectroscopy of ...SSS17a from 11.75 hours until 8.5 days after the merger. Over the first hour of observations, the ejecta rapidly expanded and cooled. Applying blackbody fits to the spectra, we measured the photosphere cooling from
11,000
−
900
+
3400
to
9300
−
300
+
300
kelvin, and determined a photospheric velocity of roughly 30% of the speed of light. The spectra of SSS17a began displaying broad features after 1.46 days and evolved qualitatively over each subsequent day, with distinct blue (early-time) and red (late-time) components. The late-time component is consistent with theoretical models of r-process–enriched neutron star ejecta, whereas the blue component requires high-velocity, lanthanide-free material.
Two-dimensional (2D) materials have been studied extensively as monolayers, vertical or lateral heterostructures. To achieve functionalization, monolayers are often patterned using soft lithography ...and selectively decorated with molecules. Here we demonstrate the growth of a family of 2D materials that are intrinsically patterned. We demonstrate that a monolayer of PtSe
can be grown on a Pt substrate in the form of a triangular pattern of alternating 1T and 1H phases. Moreover, we show that, in a monolayer of CuSe grown on a Cu substrate, strain relaxation leads to periodic patterns of triangular nanopores with uniform size. Adsorption of different species at preferred pattern sites is also achieved, demonstrating that these materials can serve as templates for selective self-assembly of molecules or nanoclusters, as well as for the functionalization of the same substrate with two different species.
On 17 August 2017, gravitational waves (GWs) were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB 170817A. An optical transient source, Swope ...Supernova Survey 17a (SSS17a),was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days postmerger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.
Given its peak luminosity and early-time spectra, ASASSN-15lh was classified as the most luminous supernova ever discovered. Here, we report a UV rebrightening of ASASSN-15lh observed with Swift ...during our follow-up campaign. The rebrightening began at t ... 90 d (observer frame) after the primary peak and was followed by a ~120-d long plateau in the bolometric luminosity, before starting to fade again at t ... 210 d. ASASSN-15lh rebrightened in the Swift UV bands by ...mUVW2 ... -1.75 mag, ...mUVM2 ... -1.25 mag and ...mUVW1 ... -0.8 mag, but did not rebrighten in the optical bands. Throughout its initial decline, subsequent rebrightening and renewed decline, the spectra did not show evidence of interactions between the ejecta and circumstellar medium such as narrow emission lines. There are hints of weak Ha emission at late-times, but Margutti et al. have shown that it is narrow line emission consistent with star formation in the host nucleus. By fitting a blackbody, we find that during the rebrightening, the effective photospheric temperature increased from TBB ... 11 000 K to TBB ... 18 000 K. Over the ~ 550 d since its detection, ASASSN-15lh has radiated ~1.7 -1.9 x 10 super( 52) erg. Although its physical nature remains uncertain, the evolution of ASASSN-15lh's photospheric radius, its radiated energy and the implied event rate, are all more similar to those of H-poor superluminous supernovae than to tidal disruption events. (ProQuest: ... denotes formulae/symbols omitted.)
Abstract
Freshwater scarcity is a global threat to modern era of human society. Sorption-based atmospheric water harvesting (AWH) is prospective to provide fresh water for remote water-stressed areas ...lacking in water and electricity. Adsorbent material plays a vital role in such AWH systems. Here, we report a solid adsorbent synthesized by impregnating hygroscopic salt lithium chloride (LiCl) into solidified activated carbon fiber felt (ACFF modified by silica sol). Composite samples immersed with different mass concentrations of silica sol are prepared and characterized for dynamic water uptake, equilibrium water uptake, textural and thermal properties. AS5Li30 (ACFF + 5 wt% silica gel + 30 wt% LiCl) exhibits an efficient water uptake of 2.1 g/g at 25 °C and 70% relative humidity (RH). The material further demonstrates a heat storage capacity of 5456 kJ/kg. Its low regeneration temperature (< 80 °C) and good cycle stability make it feasible to be used in practical water production applications, driven by solar energy and other low-grade energy. Estimation results show that water harvesting unit can produce 1.41 g
H2O
/g
AS5Li30
under 25 °C and 75% RH.
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