Some Observations on the Handling of Adams\u27 Platinum-Oxide Hydrogenation Catalyst

Two problems are present in the measurement of the exact quantities of catalyst used in hydrogenations with platinum oxide. The first arises from the fact that platinum oxide is highly adsorbent and rapidly gains weight due to adsorption of atmospheric components when it is exposed to air. A procedure is described for making an approximate correction for this weight gain. The second problem is the identity of the actual catalytic material. The observations indicate that this is platinum metal, and it is shown that the platinum content varies with the batch of catalyst

What Is Evolution? A Response to Bamforth

Douglas Bamforth\u27s recent paper in American Antiquity, Evidence and Metaphor in Evolutionary Archaeology, charges that Darwinism has little to offer archaeology except in a metaphorical sense. Specifically, Bamforth claims that arguments that allegedly link evolutionary processes to the archaeological record are unsustainable. Given Bamforth\u27s narrow view of evolution: that it must be defined strictly in terms of changes in gene frequency: he is correct. But no biologist or paleontologist would agree with Bamforth\u27s claim that evolution is a process that must be viewed fundamentally at the microlevel. Evolutionary archaeology has argued that materials in the archaeological record are phenotypic in the same way that hard parts of organisms are. Thus changes in the frequencies of archaeological variants can be used to monitor the effects of selection and drift on the makers and users of those materials. Bamforth views this extension of the human phenotype as metaphorical because to him artifacts are not somatic features, meaning their production and use are not entirely controlled by genetic transmission. He misses the critical point that in terms of evolution, culture is as significant a transmission system as genes are. There is nothing metaphorical about viewing cultural transmission from a Darwinian point of view

The Distance to NGC 4993: The Host Galaxy of the Gravitational-wave Event GW170817

The historic detection of gravitational waves from a binary neutron star merger (GW170817) and its electromagnetic counterpart led to the first accurate (sub-arcsecond) localization of a gravitational-wave event. The transient was found to be $\sim$10" from the nucleus of the S0 galaxy NGC 4993. We report here the luminosity distance to this galaxy using two independent methods. (1) Based on our MUSE/VLT measurement of the heliocentric redshift ($z_{\rm helio}=0.009783\pm0.000023$) we infer the systemic recession velocity of the NGC 4993 group of galaxies in the cosmic microwave background (CMB) frame to be $v_{\rm CMB}=3231 \pm 53$ km s$^{-1}$. Using constrained cosmological simulations we estimate the line-of-sight peculiar velocity to be $v_{\rm pec}=307 \pm 230$ km s$^{-1}$, resulting in a cosmic velocity of $v_{\rm cosmic}=2924 \pm 236$ km s$^{-1}$ ($z_{\rm cosmic}=0.00980\pm 0.00079$) and a distance of $D_z=40.4\pm 3.4$ Mpc assuming a local Hubble constant of $H_0=73.24\pm 1.74$ km s$^{-1}$ Mpc$^{-1}$. (2) Using Hubble Space Telescope measurements of the effective radius (15.5" $\pm$ 1.5") and contained intensity and MUSE/VLT measurements of the velocity dispersion, we place NGC 4993 on the Fundamental Plane (FP) of E and S0 galaxies. Comparing to a frame of 10 clusters containing 226 galaxies, this yields a distance estimate of $D_{\rm FP}=44.0\pm 7.5$ Mpc. The combined redshift and FP distance is $D_{\rm NGC 4993}= 41.0\pm 3.1$ Mpc. This 'electromagnetic' distance estimate is consistent with the independent measurement of the distance to GW170817 as obtained from the gravitational-wave signal ($D_{\rm GW}= 43.8^{+2.9}_{-6.9}$ Mpc) and confirms that GW170817 occurred in NGC 4993.Comment: 9 pages, 5 figure

Mapping the CMB II: the second flight of the QMAP experiment

We report the results from the second flight of QMAP, an experiment to map the cosmic microwave background near the North Celestial Pole. We present maps of the sky at 31 and 42 GHz as well as a measurement of the angular power spectrum covering the l-range 40-200. Anisotropy is detected at about 20 sigma and is in agreement with previous results at these angular scales. We also report details of the data reduction and analysis techniques which were used for both flights of QMAP.Comment: 4 pages, with 5 figures included. Submitted to ApJL. Window functions and color figures are available at http://pupgg.princeton.edu/~cmb/welcome.htm

Measurement of viscous sound absorption at 50-150 kHz in a model turbid environment

The visco-thermal absorption of sound by suspended particulate matter can be reliably measured using a reverberation technique. This absorption may have an adverse effect on the performance of sonars operating at 50–300 kHz in coastal waters where suspensions are often present in significant concentrations. A series of experiments has been performed to study the viscous absorption by suspensions in the frequency range of 50–150 kHz. In the test volumes employed, the effect is small. It is therefore measured by taking the difference in reverberation times of a volume of water with and without particles. This greatly reduces the effect on the measurement of the other sources of absorption. Even so, it is necessary to design the experiment to characterize and minimize acoustic losses which occur at the surfaces of the container, the hydrophones, and their cables, and losses associated with bubbles and turbulence. These effects are discussed and results for particulate absorption for suspensions of spherical glass beads are presented and compared to theoretical predictions. Measured absorption agrees well with that predicted by theory for concentrations above 0.5 kg/m3 and up to 2.0 kg/m

Galactic contamination in the QMAP experiment

We quantify the level of foreground contamination in the QMAP Cosmic Microwave Background (CMB) data with two objectives: (a) measuring the level to which the QMAP power spectrum measurements need to be corrected for foregrounds and (b) using this data set to further refine current foreground models. We cross-correlate the QMAP data with a variety of foreground templates. The 30 GHz Ka-band data is found to be significantly correlated with the Haslam 408 MHz and Reich and Reich 1420 MHz synchrotron maps, but not with the Diffuse Infrared Background Experiment (DIRBE) 240, 140 and 100 micron maps or the Wisconsin H-Alpha Mapper (WHAM) survey. The 40 GHz Q-band has no significant template correlations. We discuss the constraints that this places on synchrotron, free-free and dust emission. We also reanalyze the foreground-cleaned Ka-band data and find that the two band power measurements are lowered by 2.3% and 1.3%, respectively.Comment: 4 ApJL pages, including 4 figs. Color figures and data at http://www.hep.upenn.edu/~angelica/foreground.html#qmap or from [email protected]

Quantifying Methane Emissions in the Uintah Basin During Wintertime Stagnation Episodes

This study presents a meteorologically-based methodology for quantifying basin-scale methane (CH4) emissions in Utah’s Uintah Basin, which is home to over 9,000 active and producing oil and natural gas wells. Previous studies in oil and gas producing regions have often relied on intensive aircraft campaigns to estimate methane emissions. However, the high cost of airborne campaigns prevents their frequent undertaking, thus providing only daytime snapshots of emissions rather than more temporally-representative estimates over multiple days. Providing estimates of CH4 emissions from oil and natural gas production regions across the United States is important to inform leakage rates and emission mitigation efforts in order to curb the potential impacts of these emissions on global climate change and local air quality assessments. Here we introduce the Basin-constrained Emissions Estimate (BEE) method, which utilizes the confining topography of a basin and known depth of a pollution layer during multi-day wintertime cold-air pool episodes to relate point observations of CH4 to basin-scale CH4 emission rates. This study utilizes ground-based CH4 observations from three fixed sites to calculate daily increases in CH4, a laser ceilometer to estimate pollution layer depth, and a Lagrangian transport model to assess the spatial representativity of surface observations. BEE was applied to two cold-air pool episodes during the winter of 2015–2016 and yielded CH4 emission estimates between 44.60 +/– 9.66 × 103 and 61.82 +/– 19.76 × 103 kg CH4 hr–1, which are similar to the estimates proposed by previous studies performed in the Uintah Basin. The techniques used in this study could potentially be utilized in other deep basins worldwide

Superluminal motion of a relativistic jet in the neutron star merger GW170817

The binary neutron star merger GW170817 was accompanied by radiation across the electromagnetic spectrum and localized to the galaxy NGC 4993 at a distance of 41+/-3 Mpc. The radio and X-ray afterglows of GW170817 exhibited delayed onset, a gradual rise in the emission with time as t^0.8, a peak at about 150 days post-merger, followed by a relatively rapid decline. To date, various models have been proposed to explain the afterglow emission, including a choked-jet cocoon and a successful-jet cocoon (a.k.a. structured jet). However, the observational data have remained inconclusive as to whether GW170817 launched a successful relativistic jet. Here we show, through Very Long Baseline Interferometry, that the compact radio source associated with GW170817 exhibits superluminal motion between two epochs at 75 and 230 days post-merger. This measurement breaks the degeneracy between the models and indicates that, while the early-time radio emission was powered by a wider-angle outflow (cocoon), the late-time emission was most likely dominated by an energetic and narrowly-collimated jet, with an opening angle of <5 degrees, and observed from a viewing angle of about 20 degrees. The imaging of a collimated relativistic outflow emerging from GW170817 adds substantial weight to the growing evidence linking binary neutron star mergers and short gamma-ray bursts.Comment: 42 pages, 4 figures (main text), 2 figures (supplementary text), 2 tables. Referee and editor comments incorporate

Superintegrability and higher order polynomial algebras II

In an earlier article, we presented a method to obtain integrals of motion and polynomial algebras for a class of two-dimensional superintegrable systems from creation and annihilation operators. We discuss the general case and present its polynomial algebra. We will show how this polynomial algebra can be directly realized as a deformed oscillator algebra. This particular algebraic structure allows to find the unitary representations and the corresponding energy spectrum. We apply this construction to a family of caged anisotropic oscillators. The method can be used to generate new superintegrable systems with higher order integrals. We obtain new superintegrable systems involving the fourth Painleve transcendent and present their integrals of motion and polynomial algebras.Comment: 11 page