1,046 research outputs found
Noise spectroscopy of a quantum-classical environment with a diamond qubit
Full text linkKnowing a quantum system's environment is critical for its practical use as a
quantum device. Qubit sensors can reconstruct the noise spectral density of a
classical bath, provided long enough coherence time. Here we present a protocol
that can unravel the characteristics of a more complex environment, comprising
both unknown coherently coupled quantum systems, and a larger quantum bath that
can be modeled as a classical stochastic field. We exploit the rich environment
of a Nitrogen-Vacancy center in diamond, tuning the environment behavior with a
bias magnetic field, to experimentally demonstrate our method. We show how to
reconstruct the noise spectral density even when limited by relatively short
coherence times, and identify the local spin environment. Importantly, we
demonstrate that the reconstructed model can have predictive power, describing
the spin qubit dynamics under control sequences not used for noise
spectroscopy, a feature critical for building robust quantum devices. At lower
bias fields, where the effects of the quantum nature of the bath are more
pronounced, we find that more than a single classical noise model are needed to
properly describe the spin coherence under different controls, due to the back
action of the qubit onto the bath.Comment: Main text: 5 pages, 5 figures. Supplemental material: 7 pages, 7
figures, 4 table
Review: Borders
Get PDFA review of the 2021 book by Thomas King and Natasha Donovan, âBorders,â for inclusion in ARLIS/NA's 2021 Notable Graphic Novels Review
Assessment of habitat quality and landscape connectivity for forest-dependent cracids in the Sierra Madre del Sur Mesoamerican biological corridor, Mexico
Get PDFAssessing landscape connectivity allows us to identify critical areas that impede or facilitate the movement of organisms and their genes and to plan their conservation and management. In this article, we assessed landscape connectivity and ecological condition of the habitat patches of a highly biodiverse region in Chiapas, Mexico. We employed data of three cracid species with different characteristics in habitat use and mobility. The habitat map of each species was derived from a spatial intersection of the models of potential distribution and a high-resolution map of current land cover and land use. The ecological condition of vegetation types was evaluated using 75 field plots. Structure of landscape was estimated by fragmentation metrics, while functional connectivity was assessed using spatially explicit graph analysis. The extent of suitable habitat for Oreophasis derbianus, Penelopina nigra, and Penelope purpurascens correspond to 25%, 46%, and 55% of the study area (5,185.6âkm2), respectively. Although the pine-oak forests were the most fragmented vegetation type, habitats of the three species were well connected, and only 4% to 9% of the fragments located on the periphery of the corridor had low connectivity. Landscape connectivity depends mainly on land uses with an intermediate and lower ecological condition (secondary forests and coffee agroforestry systems). Therefore, we suggest that in addition to promoting the improvement in connectivity in fragmented forests, conservation efforts should be aimed at preventing the conversion of mature forests into agricultural uses and maintaining agroforestry systems
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Effect of voicing and articulation manner on aerosol particle emission during human speech.
Get PDFPreviously, we demonstrated a strong correlation between the amplitude of human speech and the emission rate of micron-scale expiratory aerosol particles, which are believed to play a role in respiratory disease transmission. To further those findings, here we systematically investigate the effect of different 'phones' (the basic sound units of speech) on the emission of particles from the human respiratory tract during speech. We measured the respiratory particle emission rates of 56 healthy human volunteers voicing specific phones, both in isolation and in the context of a standard spoken text. We found that certain phones are associated with significantly higher particle production; for example, the vowel /i/ ("need," "sea") produces more particles than /É/ ("saw," "hot") or /u/ ("blue," "mood"), while disyllabic words including voiced plosive consonants (e.g., /d/, /b/, /g/) yield more particles than words with voiceless fricatives (e.g., /s/, /h/, /f/). These trends for discrete phones and words were corroborated by the time-resolved particle emission rates as volunteers read aloud from a standard text passage that incorporates a broad range of the phones present in spoken English. Our measurements showed that particle emission rates were positively correlated with the vowel content of a phrase; conversely, particle emission decreased during phrases with a high fraction of voiceless fricatives. Our particle emission data is broadly consistent with prior measurements of the egressive airflow rate associated with the vocalization of various phones that differ in voicing and articulation. These results suggest that airborne transmission of respiratory pathogens via speech aerosol particles could be modulated by specific phonetic characteristics of the language spoken by a given human population, along with other, more frequently considered epidemiological variables
Review: Stone Fruit
Get PDFA review of the 2021 book by Lee Lai, âStone Fruit,â for inclusion in ARLIS/NA's 2021 Notable Graphic Novels Review
Review: Tono Monogatari
Get PDFA review of the 2021 book by Shigeru Mizuki, âTono Monogatari,â for inclusion in ARLIS/NA's 2021 Notable Graphic Novels Review
Review: Ex Libris
Get PDFA review of the 2021 book by Matt Madden, âEx Libris,â for inclusion in ARLIS/NA's 2021 Notable Graphic Novels Review
Cuban Modernism: Mid-Century Architecture, 1940-1970
Get PDFReview of Cuban Modernism: Mid-Century Architecture, 1940-1970, Reviewed July 2021 by Nicole Santiago, Information Literacy Librarian, University of Pennsylvania, [email protected]
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