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We analyze the supply-side disruptions associated with COVID-19. We find that sectors in which a higher fraction of the workforce is not able to work remotely experienced greater declines in employment and expected revenue growth, worse stock market performance, and higher likelihood of default. The stock market overweights low-exposure industries. Thus, our findings cast light on the disconnect between stock market indices and aggregate outcomes. We combine these ex ante heterogeneous industry exposures with daily financial market data to create a stock return portfolio that tracks news about the supply-side disruptions resulting from the pandemic. (JEL G12, D22, H25, J20, E00) Received June 1, 2021; editorial decision August 16 2021, by Editor Jeffrey Pontiff.

In this work, we measure continuous thermal radiance from evolving clouds of liquid metal fragments ejected into vacuum, nonreactive, and reactive gas. We implement a model for the thermalization of the ejecta and gas and use this to constrain the absolute temperature of the ejecta cloud. This model enables further analyses of ejecta thermal behavior under a variety of conditions.

We present an experimental result of significantly increased heating in a laser-driven blastwave experiment carried out at the OMEGA laser facility. Abnormally high temperatures were observed in warm dense CH compared to older experiments and theoretical predictions. The higher temperatures in compressed CH were linked to an improved smoothness of the laser intensity profile, which resulted in better efficiency of the drive and coupling of more energy into the system compared to previous similar experiments. Fifteen beams with combined intensity of ∼7× 1014 W cm−2 and a square intensity profile with 2 ns duration were used to drive a strong shock, which subsequently developed to a blastwave travelling through low density CH foam creating warm dense matter. Multiple diagnostics were used to examine the thermodynamic conditions in the warm dense CH foam. Velocity interferometry (VISAR) and streaked pyrometry (SOP) observed increased blastwave velocities, while x-ray Thomson scattering (XRTS) measured elevated temperatures of 17.5 − 35 eV in compressed CH foam. The experimental results were compared to hydrodynamic simulations and a potential contribution from x-rays to the elevated temperatures in the dense material was considered.

The regioselective sulfation of a Lex-trisaccharide having free hydroxyl groups in 2-, 3- and 4- position of the galactose elucidated their different reactivities and gave mono- and disulfated Lex derivatives.

By forcing He II out of a tube, large-scale vortex rings with diameters of about 1 cm and normal-fluid and superfluid circulations of some cm 2/s were produced. The circulations, the vorticity distributions, the dimensions, and also the translational velocity of these vortex rings were investigated by means of a method of measurement based on the Doppler effect of first and second sound. All parameters of the vortex rings turned out to be independent of temperature. Already during the ejection of the fluid both the normal and the superfluid circulation were identical. This result is explained in terms of the formation of a superfluid boundary layer at the inner wall of the tube and the interaction of normal and superfluid flow due to the mutual friction force.

The Nuclear Regulatory Commission (NRC) announced the availability of three new documents concerning radioactive materials in sewage sludge and ash from publicly owned treatment works (POTW). One of the documents is a report presenting the results of a volunteer survey of sewage sludge and ash samples provided by 313 POTWs. The second document is a dose modeling document, using multiple exposure pathway modeling focused on a series of generic scenarios, to track possible exposure of POTW workers and members of the general public to radioactivity from the sewage sludge or ash. The third document is a guidance report providing recommendations on the management of radioactivity in sewage sludge and ash for POTW owners and operators. This paper explains how radioactive materials enter POTWs, provides criteria for evaluating levels of radioactive material in sludge and ash, and gives a summary of the results of the survey and dose modeling efforts.

The MILDOS-AREA code was developed to estimate radiological doses and risks from uranium milling activities. The code has been used for demonstrating radiological compliance regarding the U.S. Nuclear Regulatory Commission's licensing requirements for uranium milling activities. The code was recently updated with an enhanced software package to address the following four areas: regulatory changes, in-situ leaching extraction technologies, software user interfaces, and software distribution technologies via the internet. Users can now specify in-situ leaching processes through a Windows object-based Geographic information System interface with incorporated updated regulation methodologies. The code and documentation are freely distributed through the Internet.

The Feed Materials Production Center, northwest of Cincinnati, processed uranium concentrates and uranium compounds recycled from other stages of nuclear weapons production, as well as some uranium ore and thorium. Particulate releases were primarily uranium (natural, depleted, and slightly enriched. In addition, two large silos containing radium-bearing residues were emission sources of radon and its decay products. The Fernald Dosimetry Reconstruction Project was undertaken to help the Centers for Disease Control and Prevention to evaluate the impact of the Feed Materials Production Center on the public from radionuclides released to the environment from 1951 through 1988. At this point in the study, the project has estimated the quantities of radioactive materials released to air, surface water, and in groundwater; developed the methodology to describe the environmental transport of the materials; developed mathematical models to calculate the resulting radiation doses; and evaluated environmental monitoring data to verify that the estimates of releases and transport are reasonable. Thorough review of historical records and extensive interaction with former and current employees and residents have been the foundation for reconstructing routine operations, documenting accidents, and evaluating unmonitored emission sources. The largest releases of uranium to air and water occurred in the 1950's and 1960's. Radon releases from the silos remained elevated through most of the 1970's. The quantity of uranium released to surface water was much less than that released to air. Best estimates of releases are reported as median values, with associated uncertainties calculated as an integral part of the estimates. Screening calculations showed that atmospheric pathways dominate the total dose from Feed Materials Production Center releases. Accordingly, the local meteorology, effluent particle size and chemical form, and wet and dry deposition, were particularly important in this study. The final goal of the project is the calculation of radiation doses to people living in the study domain, which is represented by a circle with radius of 10 km centered on the Feed Materials Production Center production area.

In order to optimize gold-tin metal film probes as bolometers for measurement of fast second-sound signals in He II, the influence of their composition and of annealing on their electrical properties at low temperatures was investigated systematically. Measurements of the dependence of the voltage-current characteristics on temperature were supplemented by electron microscopy of the film surfaces and by measurement of the resistivity of the composed films at room temperature as a function of the atomic percentage of tin. Fast interdiffusion, which took place after evaporating typically 1000 A of tin onto 200 A of gold, resulted in the development of different phases of the Au-Sn system in the layer. Due to proximity effects between grains of these phases the transition temperature of such a film is reduced to the temperature range of He II. Different types of weak-link behavior which may govern the current-induced breakdown of superconductivity are discussed. As an example of the application of the metal film probes, the circulation of a macroscopic vortex ring was measured using the flow-induced variation of the traveling times of second-sound shock waves. Values of up to several cm2/sec were thus obtained to an accuracy of some 10−2 cm2/sec.

Messungen der Temperaturschwankungen in Stromungen sind mit den bisher gebrauchlichen, relativ tragen Messonden nur bei niedrigen Schwankungsfrequenzen moglich. Eine in ihrer Bauform neuartige, nach dem Prinzip eines Widerstandsthermometers arbeitende Metallfilmsonde gestattet die bisherigen Grenzen betrachtlich hinauszuschieben, so das Temperaturschwankungen in der Grosenordnung von 0,01°C noch bei Schwankungsfrequenzen bis etwa 5 kHz gemessen werden konnen. Der Aufbau, das Verfahren zur Herstellung sowie ein Eichverfahren fur die neu entwickelte Sonde werden beschrieben und ihre Brauchbarkeit fur Temperaturschwankungsmessungen in Stromungen an einigen Beispielen (Messungen naturlicher Temperaturschwankungen in einem Rundstabnachlauf in Luft bei einer Reynoldszahl von etwa 5 · 104) demonstriert. Auf einige weitere Anwendungen, in denen sich die hohe Empfindlichkeit und die geringe thermische Tragheit der Sonde besonders gunstig auswirken, wird hingewiesen (Stromungsgeschwindigkeitsmessungen, Messung schneller Temperaturanderungen mit Infrarotdetektoren).

Experiments in the wake of a circular rod at a Reynolds number Re=5·104 have shown that single vortex-like structures can leave the wake and may be detected in the ambient potential flow. This experimental finding suggested the theoretical investigation of the interaction between a vortex and a shear flow. Lin has calculated the average acceleration acting on the vortex at the time t = 0. In the following a finite-difference scheme is described which, in detail, determines the local components of the acceleration and the temporal development of the flow.

The vorticity produced by forcing He II out of a tube 8 mm in diameter was investigated in the region in front of the tube orifice. By a non-disturbing method of measurement based on the flow-induced differences in running times of second-sound shock waves, the formation of large scale vortex rings was observed and measured. The circulation of their normalfluid velocity field was found to be not conserved.

A Monte Carlo computer code (OREC) for calculating the detailed transport and energy deposition for primary electrons and all of their secondaries in liquid water has been investigated for use in beta-ray dosimetry. Some modifications have been made in the original code for its application to tissue and tissue-equivalent materials. The code gives reasonably good agreement with beta spectral data and depth-dose curves measured in tissue-equivalent plastics for several calibrated beta sources. The calculations permit a direct evaluation of the skin dose equivalent, i.e., the dose equivalent, Hs(0.07), at a depth of 0.070 mm in tissue. Calculations are presented for monoenergetic electrons, showing the distributions in the maximum depth of penetration and in the total pathlength traveled. Direct comparisons are made between depth-dose curves calculated for 99Tc and 147Pm plaque sources and measurements made with extrapolation chambers. The energy spectrum of beta particles emerging from a thick 99Tc plaque source also is calculated, and the angular distribution is found to be almost independent of the energy. The pulse-height spectrum in a tissue-equivalent plastic scintillator calculated for this source shows good agreement with the measured spectrum. The calculations also provide the Hs(0.07) dose equivalent for the 99Tc source, which is found to be consistent with that inferred independently from the spectral measurements. A calculated curve for converting spectrometer measurements to Hs(0.07) dose equivalent is in good agreement with a semi-empirical curve that was developed independently. It appears that calculations made with the electron transport code for water can provide useful information for beta dosimetry.

To detect second-sound shock waves in He II, suitable thermometers are needed that respond to small temperature variations, about 1 mK, at frequencies of more than 1 MHz. High sensitivity combined with short response time is obtained by using the discontinuity of the resistance of an evaporated superconducting metal film at the transition from superconductance to normal conductance. Since there are no superconducting materials available with a transition temperature in the interesting region between about 1.2 K and Tλ = 2.17 K, Laguna1 tested evaporated films composed of different materials, and he was most successful with layers consisting of gold successively evaporated on tin. The transition temperature of such layers was decreased to about 2 K. To adjust the transition temperature in each experiment exactly to the temperature of the He II bath, Laguna applied an external magnetic field. Later on, Cummings, Schmidt, and Wagner2 made second-sound experiments with gold-tin films that required no external magnetic field. In the work presented here as an abridged version of a more detailed paper,3 the electrical properties and the structure of such zero- field sensors were investigated to optimize their sensitivity at a given temperature.