| 351. |
- Hao, Jiaming, et al.
(author)
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Design of an ultrathin broadband transparent and high-conductive screen using plasmonic nanostructures
- 2012
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In: Optics Letters. - 0146-9592 .- 1539-4794. ; 37:23, s. 4955-4957
-
Journal article (peer-reviewed)abstract
- In this Letter, we present a new type of ultrathin antireflection transparent and high-conductive screen based on plasmonic nanostructures that does not suffer from high loss and thickness coating and also can be used as good conductive material due to super electrical conductivity of the component (noble metal). Low reflection and greatly enhanced transmissions over a broad spectral range are observed at optical telecommunication frequencies in arbitrary polarizations. The performance is almost insensitive of the angle of incidence.
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| 352. |
- Heitto, Arto, et al.
(author)
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Analysis of atmospheric particle growth based on vapor concentrations measured at the high-altitude GAW station Chacaltaya in the Bolivian Andes
- 2024
-
In: Atmospheric Chemistry and Physics. - 1680-7316 .- 1680-7324. ; 24, s. 1315-1328
-
Journal article (peer-reviewed)abstract
- Early growth of atmospheric particles is essential for their survival and ability to participate in cloud formation. Many different atmospheric vapors contribute to the growth, but even the main contributors still remain poorly identified in many environments, such as high-altitude sites. Based on measured organic vapor and sulfuric acid concentrations under ambient conditions, particle growth during new particle formation events was simulated and compared with the measured particle size distribution at the Chacaltaya Global Atmosphere Watch station in Bolivia (5240ma.s.l.) during April and May 2018, as a part of the SALTENA (Southern Hemisphere high-ALTitude Experiment on particle Nucleation and growth) campaign. Despite the challenging topography and ambient conditions around the station, the simple particle growth model used in the study was able to show that the detected vapors were sufficient to explain the observed particle growth, although some discrepancies were found between modeled and measured particle growth rates. This study, one of the first of such studies conducted on high altitude, gives insight on the key factors affecting the particle growth on the site and helps to improve the understanding of important factors on high-altitude sites and the atmosphere in general. Low-volatility organic compounds originating from multiple surrounding sources such as the Amazonia and La Paz metropolitan area were found to be the main contributor to the particle growth, covering on average 65% of the simulated particle mass in particles with a diameter of 30nm. In addition, sulfuric acid made a major contribution to the particle growth, covering at maximum 37% of the simulated particle mass in 30nm particles during periods when volcanic activity was detected on the area, compared to around 1% contribution on days without volcanic activity. This suggests that volcanic emissions can greatly enhance the particle growth.
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| 353. |
- Hering, Bernhard J., et al.
(author)
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Prolonged diabetes reversal after intraportal xenotransplantation of wild-type porcine islets in immunosuppressed nonhuman primates
- 2006
-
In: Nature Medicine. - : Nature Publishing Group. - 1078-8956 .- 1546-170X. ; 12:3, s. 301-303
-
Journal article (peer-reviewed)abstract
- Cell-based diabetes therapy requires an abundant cell source. Here, we report reversal of diabetes for more than 100 d in cynomolgus macaques after intraportal transplantation of cultured islets from genetically unmodified pigs without Gal-specific antibody manipulation. Immunotherapy with CD25-specific and CD154-specific monoclonal antibodies, FTY720 (or tacrolimus), everolimus and leflunomide suppressed indirect activation of T cells, elicitation of non-Gal pig-specific IgG antibody, intragraft expression of proinflammatory cytokines and invasion of infiltrating mononuclear cells into islets.
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| 354. |
- Hibar, Derrek P., et al.
(author)
-
Novel genetic loci associated with hippocampal volume
- 2017
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
-
Journal article (peer-reviewed)abstract
- The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (r(g) = -0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.
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| 355. |
- Hsu, Li-Han, 1981, et al.
(author)
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Design of Flip-Chip Interconnect Using Epoxy-Based Underfill Up to V-Band Frequencies With Excellent Reliability
- 2010
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In: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 58:8, s. 2244-2250
-
Journal article (other academic/artistic)abstract
- This study demonstrates a flip-chip interconnect with epoxy-based underfill (epsilon(r) = 3.5 and tan delta = 0.02 at 10 MHz) for packaging applications up to V-band frequencies. To achieve the best interconnect performance, both the matching designs on GaAs chip and Al2O3 substrate were adopted with the underfill effects taken into consideration. The optimized flip-chip interconnect showed excellent performance from dc to 67 GHz with return loss below -20 dB and insertion loss less than 0.6 dB. Furthermore, the dielectric loss induced by the underfill was extracted from measurement and compared with the simulation results. The reliability tests including 85 degrees C/85 % relative humidity test, thermal cycling test, and shear force test were performed. For the first time, the S-parameters measurement was performed to check the flip-chip reliability, and no performance decay was observed after 1000 thermal cycles. Moreover, the mechanical strength was improved about 12 times after the underfill was applied. The results show that the proposed flip-chip architecture has excellent reliability and can be applied for commercial applications.
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| 356. |
- Hsu, Li-Han, 1981, et al.
(author)
-
Fabrication process and 110 GHz measurement result of MS-to-CPW RF-via transition for RF-MEMS devices packaging applications
- 2009
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In: 2009 International Conference on Compound Semiconductor Manufacturing Technology, CS MANTECH 2009. - 9781893580138
-
Conference paper (peer-reviewed)abstract
- This paper presents the fabrication process of RF-via (0-level) and flip-chip bump (1-level) transitions for applications of packaging MS (microstrip) RF-MEMS devices. The interconnect structure with MS-to-CPW transition between GaAs MEMS substrate and Al2O3 motherboard was in-house fabricated. A novel fabrication process for RF-MEMS packaging is in detail. After fabrication, the samples were measured up to 110 GHz using on-wafer probing measurement. From the measured results, the insertion loss of entire interconnect structure is better than -2 dB up to 100 GHz, documenting the feasibility for millimeter-wave RF-MEMS devices packaging applications.
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| 357. |
- Huang, Lei, et al.
(author)
-
Harnessing science, technology, and innovation to drive synergy between Climate Goals and the SDGs
- 2024
-
In: Innovation. - : Cell Press. - 2666-6758 .- 2666-6758.
-
Journal article (peer-reviewed)abstract
- The United Nations passed two important resolutions, Transforming our World: The 2030 Agenda for Sustainable Development and the Paris Agreement in 2015 to change our world. The 17 Sustainable Development Goals (SDGs) were adopted as the core of the 2030 Agenda for Sustainable Development which set out a 15-year plan to achieve the Goals. The overarching goal of the Paris Agreement is to hold the increase in the global average temperature to below 2°C above the pre-industrial levels, and pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels. Science, technology, and innovation (STI) is one of the most prominent strategies promoted to aid SDG implementation. In this perspective, we provide specific mechanisms and strategies for STI to jointly promote climate change goals and SDGs.
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| 358. |
- Huang, Shuo, et al.
(author)
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Thermo-elastic behavior of hexagonal Sc-Ti-Zr-Hf high-entropy alloys
- 2022
-
In: Journal of Physics D. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 55:23
-
Journal article (peer-reviewed)abstract
- Recent advances in tuning the long-standing strength-ductility tradeoff have drawn attention to high-entropy alloys (HEAs), and the appearance of hexagonal close-packed (hcp) structures has been emphasized. However, few studies have explored the elastic moduli of hcp HEAs, which is of prime importance for improved understanding of the outstanding mechanical properties. In this work, we focus on a set of equiatomic rare-earth-free HEAs with hcp structures, i.e. ScTiZr, ScTiHf, ScZrHf, TiZrHf, and ScTiZrHf, and their thermo-elastic properties are studied using quantum mechanical first-principles methods. It is found that, for all considered HEAs, the hexagonal axial ratio shows a weak dependence on the temperature effect, and the thermal expansion coefficient remains almost unchanged above room temperature. From the calculated temperature-dependent single-crystal elastic constants, we analyzed the mechanical stability, elastic anisotropy, and derived polycrystalline moduli. Results indicate that the present HEAs exhibit rather high elastic isotropy and large elastic softening resistance. The ab initio predicted Young's modulus, shear modulus, and specific modulus do not obey the rule of mixture, which indicates that there exists a strong intrinsic hardening effect in all of the considered HEAs. The calculated results are in good agreement with the available experimental measurements.
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| 359. |
- Huang, Wei, et al.
(author)
-
Variation in chemical composition and volatility of oxygenated organic aerosol in different rural, urban, and mountain environments
- 2024
-
In: Atmospheric Chemistry and Physics. - 1680-7316 .- 1680-7324. ; 24:4, s. 2607-2624
-
Journal article (peer-reviewed)abstract
- The apparent volatility of atmospheric organic aerosol (OA) particles is determined by their chemical composition and environmental conditions (e.g., ambient temperature). A quantitative, experimental assessment of volatility and the respective importance of these two factors remains challenging, especially in ambient measurements. We present molecular composition and volatility of oxygenated OA (OOA) particles in different rural, urban, and mountain environments (including Chacaltaya, Bolivia; Alabama, US; Hyytiälä, Finland; Stuttgart and Karlsruhe, Germany; and Delhi, India) based on deployments of a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO-CIMS). We find on average larger carbon numbers (nC) and lower oxygen-To-carbon (O:C) ratios at the urban sites (nC: 9.8±0.7; O:C: 0.76±0.03; average ±1 standard deviation) compared to the rural (nC: 8.8±0.6; O:C: 0.80±0.05) and mountain stations (nC: 8.1±0.8; O:C: 0.91±0.07), indicative of different emission sources and chemistry. Compounds containing only carbon, hydrogen, and oxygen atoms (CHO) contribute the most to the total OOA mass at the rural sites (79.9±5.2%), in accordance with their proximity to forested areas (66.2±5.5% at the mountain sites and 72.6±4.3% at the urban sites). The largest contribution of nitrogen-containing compounds (CHON) is found at the urban stations (27.1±4.3%), consistent with their higher NOx levels. Moreover, we parametrize OOA volatility (saturation mass concentrations, Csat) using molecular composition information and compare it with the bulk apparent volatility derived from thermal desorption of the OOA particles within the FIGAERO. We find differences in Csat values of up to 1/43 orders of magnitude and variation in thermal desorption profiles (thermograms) across different locations and systems. From our study, we draw the general conclusion that environmental conditions (e.g., ambient temperature) do not directly affect OOA apparent volatility but rather indirectly by influencing the sources and chemistry of the environment and thus the chemical composition. The comprehensive dataset provides results that show the complex thermodynamics and chemistry of OOA and their changes during its lifetime in the atmosphere. We conclude that generally the chemical description of OOA suffices to predict its apparent volatility, at least qualitatively. Our study thus provides new insights that will help guide choices of, e.g., descriptions of OOA volatility in different model frameworks such as air quality models and cloud parcel models.
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| 360. |
- Issaoun, Sara, et al.
(author)
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Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope
- 2022
-
In: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 934:2
-
Journal article (peer-reviewed)abstract
- The blazar J1924-2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic center's black hole Sagittarius A*. Here we present the first total and linearly polarized intensity images of this source obtained with the unprecedented 20 mu as resolution of the EHT. J1924-2914 is a very compact flat-spectrum radio source with strong optical variability and polarization. In April 2017 the source was observed quasi-simultaneously with the EHT (April 5-11), the Global Millimeter VLBI Array (April 3), and the Very Long Baseline Array (April 28), giving a novel view of the source at four observing frequencies, 230, 86, 8.7, and 2.3 GHz. These observations probe jet properties from the subparsec to 100 pc scales. We combine the multifrequency images of J1924-2914 to study the source morphology. We find that the jet exhibits a characteristic bending, with a gradual clockwise rotation of the jet projected position angle of about 90 degrees between 2.3 and 230 GHz. Linearly polarized intensity images of J1924-2914 with the extremely fine resolution of the EHT provide evidence for ordered toroidal magnetic fields in the blazar compact core.
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