1,425 research outputs found
Miniature spray-painting booth
Transparent spray booth provides method for quality painting and repair of surfaces in clean room or other specialized environments. Overspray and virtually all contaminating vapor and odor can be eliminated. Touch-up painting is achieved with spray gun
Archaeological Data and Small Projects: A Case Study from the Pyla-Koustopetria Archaeological Project on Cyprus
A case study in how small projects use digital tools
Volume Flow Rate Estimation for Small Explosions at Mt. Etna, Italy, From Acoustic Waveform Inversion
Rapid assessment of the volume and the rate at which gas and pyroclasts are injected into the
atmosphere during volcanic explosions is key to effective eruption hazard mitigation. Here, we use data
from a dense infrasound network deployed in 2017 on Mt. Etna, Italy, to estimate eruptive volume flow
rates (VFRs) during small gas-and-ash explosions.We use a finite-difference time-domain approximation
to compute the acoustic Green's functions and perform a full waveform inversion for a multipole source,
combining monopole and horizontal dipole terms. The inversion produces realistic estimates of VFR, on
the order of 4 × 104 m3/s and well-defined patterns of source directivity. This is the first application of
acoustic waveform inversion at Mt. Etna. Our results demonstrate that acoustic waveform inversion is a
mature and robust tool for assessment of source parameters and holds potential as a tool to provide rapid
estimates of VFR in near real time.This study was supported by NERC
Grant NE/P00105X/1 and by European
Unions Horizon 2020 Research and
Innovation Programme Under the
Marie Sklodowska-Curie Grant
Agreement 798480
Novel Approaches to Monitor and Manipulate Single Neurons In Vivo
The complexity of the vertebrate brain poses an enormous challenge to experimental neuroscience. One way of dealing with this complexity has been to investigate different aspects of brain function in widely different preparations, each best suited to address a particular question. Accordingly, cellular questions are typically addressed with intracellular recordings in in vitro preparations such as brain slices or neuronal cultures, whereas network behavior and sensory or motor response properties are analyzed in vivo, often with extracellular recordings. This division of labor has proved to be an experimentally effective strategy. However, although there seems to be no limit to the wealth of data that can be generated in this way, integrating results derived in different preparations comes with its own set of challenges. The enormous difficulties encountered when one attempts to link cellular phenomena such as synaptic plasticity to systems properties such as spatial memory (Martin et al., 2000) have shown us that close collaboration between molecular−cellular and systems neuroscience is required (Tonegawa et al., 2003) and that we need more convergence of experimental techniques to analyze the cellular basis of neural function under more natural conditions. Studying neurons under naturalistic conditions is, however, easier said than done. A return to in vivo preparations will only be successful if we are able to solve the technical problems that led previous researchers to abandon the study of intact brains in the first place. Thus, studying neurons at the cellular level in vertebrate brains is today first and foremost a technological challenge. Here we highlight recent efforts to improve our ability to analyze functions of single neurons in vivo. Given th
Acoustic source inversion to estimate volume flux from volcanic explosions
We present an acoustic waveform inversion technique for infrasound data to estimate volume fluxes from volcanic eruptions. Previous inversion techniques have been limited by the use of a 1-D Green's function in a free space or half space, which depends only on the source-receiver distance and neglects volcanic topography. Our method exploits full 3-D Green's functions computed by a numerical method that takes into account realistic topographic scattering. We apply this method to vulcanian eruptions at Sakurajima Volcano, Japan. Our inversion results produce excellent waveform fits to field observations and demonstrate that full 3-D Green's functions are necessary for accurate volume flux inversion. Conventional inversions without consideration of topographic propagation effects may lead to large errors in the source parameter estimate. The presented inversion technique will substantially improve the accuracy of eruption source parameter estimation (cf. mass eruption rate) during volcanic eruptions and provide critical constraints for volcanic eruption dynamics and ash dispersal forecasting for aviation safety. Application of this approach to chemical and nuclear explosions will also provide valuable source information (e.g., the amount of energy released) previously unavailable. Key Points First waveform inversion of volcano infrasound using a 3-D Green's function Strong topographic scattering must be considered for source inversion The method substantially improves the accuracy of eruption source parameter estimation
A constraint on antigravity of antimatter from precision spectroscopy of simple atoms
Consideration of antigravity for antiparticles is an attractive target for
various experimental projects. There are a number of theoretical arguments
against it but it is not quite clear what kind of experimental data and
theoretical suggestions are involved. In this paper we present straightforward
arguments against a possibility of antigravity based on a few simple
theoretical suggestions and some experimental data. The data are: astrophysical
data on rotation of the Solar System in respect to the center of our galaxy and
precision spectroscopy data on hydrogen and positronium. The theoretical
suggestions for the case of absence of the gravitational field are: equality of
electron and positron mass and equality of proton and positron charge. We also
assume that QED is correct at the level of accuracy where it is clearly
confirmed experimentally
A Panel of Papers Examining COVID-19 Masking and Vaccination Advertisements
This panel of papers harnesses persuasion theories to examine the content of masking and vaccination advertisements and public service announcements concerning COVID-19. The first paper describes major persuasion approaches, the rationale for the studies, and the methodology. The second and third papers describe the results of the content analyses, along with their implications for media messages on COVID and future research on these topics
- …