Nuclear Isomerism in Rhodium

Pontecorvo has recently pointed out that Rh^(104) emits numerous electrons of energy 35—60 kev. He ascribes these electrons to the internal conversion of the gamma-radiation emitted when the Rh^(104) nucleus goes from an excited state (4.2-minute period) to the ground state. From the ground state there is beta-emission which gives Pd^(104) and is ascribed to the 44-second period. The emission of the gamma-ray from the excited state is an alternative process to the direct emission of a beta-ray from the excited state. In this latter connection the beta-ray spectra associated with the two periods are of interest

Modeling of activated carbon and coal gasification char absorbents in single-solute and bisolute systems

A mathematical model of fixed-bed adsorption was used to predict the bed response to a sustained step change in influent concentration. The model was employed to compare the performance of different adsorbents in the removal of organics from water and to analyze factors that affect desorption owing to a decrease in influent concentration and to competitive adsorption. Model equations, which considered that film transfer and surface diffusion controlled the adsorption rate, were solved with the technique of orthogonal collocation. Three species, 3,5-dimethylphenol (DMP), 3,5-dichlorophenol (DCP) and rhodamine 6G (R6G), were the single solutes studied, and the two phenols were also examined as a mixture. Four activated carbons and a coal gasification char were the adsorbents studied. The model was used to compare the adsorbents in the removal of DMP, R6G and the bisolute mixtures and equilibrium capacity was found to have a greater influence than kinetics on fixed-bed performance. It was observed that, under conditions approximating a drinking water plant, the time during which the effluent concentration of a desorbed species was higher than the influent concentration was significant (on the order of weeks) whether a reduced influent concentration or competition was responsible for the desorption.U.S. Department of the InteriorU.S. Geological SurveyOpe

Measurement of Electron Trapping in the CESR Storage Ring

The buildup of low-energy electrons has been shown to affect the performance of a wide variety of particle accelerators. Of particular concern is the persistence of the cloud between beam bunch passages, which can impose limitations on the stability of operation at high beam current. We have obtained measurements of long-lived electron clouds trapped in the field of a quadrupole magnet in a positron storage ring, with lifetimes much longer than the revolution period. Based on modeling, we estimate that about 7% of the electrons in the cloud generated by a 20-bunch train of 5.3 GeV positrons with 16-ns spacing and $1.3x10^{11}$ population survive longer than 2.3 $\mu$s in a quadrupole field of gradient 7.4 T/m. We have observed a non-monotonic dependence of the trapping effect on the bunch spacing. The effect of a witness bunch on the measured signal provides direct evidence for the existence of trapped electrons. The witness bunch is also observed to clear the cloud, demonstrating its effectiveness as a mitigation technique.Comment: 6 pages, 9 figures, 28 citation

The Low Redshift survey at Calar Alto (LoRCA)

The Baryon Acoustic Oscillation (BAO) feature in the power spectrum of galaxies provides a standard ruler to measure the accelerated expansion of the Universe. To extract all available information about dark energy, it is necessary to measure a standard ruler in the local, z<0.2, universe where dark energy dominates most the energy density of the Universe. Though the volume available in the local universe is limited, it is just big enough to measure accurately the long 100 Mpc/h wave-mode of the BAO. Using cosmological N-body simulations and approximate methods based on Lagrangian perturbation theory, we construct a suite of a thousand light-cones to evaluate the precision at which one can measure the BAO standard ruler in the local universe. We find that using the most massive galaxies on the full sky (34,000 sq. deg.), i.e. a K(2MASS)<14 magnitude-limited sample, one can measure the BAO scale up to a precision of 4\% and 1.2\% using reconstruction). We also find that such a survey would help to detect the dynamics of dark energy.Therefore, we propose a 3-year long observational project, named the Low Redshift survey at Calar Alto (LoRCA), to observe spectroscopically about 200,000 galaxies in the northern sky to contribute to the construction of aforementioned galaxy sample. The suite of light-cones is made available to the public.Comment: 15 pages. Accepted in MNRAS. Please visit our website: http://lorca-survey.ft.uam.es

L’influenza dell’attaccamento e della sensibilità diadica genitorialesullo sviluppo psicomotorio del bambino nato pretermine

Lo scopo di questa ricerca è studiare i precursori dell’attaccamento e la sensibilità diadica genitoriale nelle famiglie con bambino nato pretermine. Sono state considerate 110 famiglie delle quali 55 con figli nati pretermine ( peso alla nascita < 1500 gr.) per un totale di 330 soggetti valutati durante i primi sei mesi di età corretta del bambino. Le diadi madre-bambino e padre-bambino sono state sottoposte al CARE-Index, una procedura videoregistrata per la valutazione dei precursori dell’attaccamento; ad entrambi i genitori sono stati somministrati CES-D, per la valutazione della depressione e STAI Y-2, per la valutazione dell’ansia di tratto. Lo sviluppo psicomotorio dei neonati è stato valutato tramite le scale Bayley. Rispetto ai controlli, nelle madri dei bambini pretermine sono stati evidenziati bassi punteggi di Sensibilità Diadica al CARE-Index (p=.025) ed elevati livelli di ansia (p=.026). Nei padri sono stati riscontrati bassi punteggi di Sensibilità Diadica (p=.004) e alti livelli di sintomi depressivi (p=.003). Nelle famiglie pretermine i precursori dell’attaccamento sono più frequentemente di tipo insicuro nelle madri (p=.000) e nei padri (p=.000), mentre nei neonati solo nell’interazione con la madre (p=012). Questi fattori sono risultati associati a minori punteggi alle scale Bayley (p=.000). Nelle madri dei neonati pretermine si riscontrano frequenti difficoltà con la famiglia di origine, nei padri una percezione negativa del proprio bambino e una maggiore insoddisfazione per l’assistenza ricevuta. Questi risultati evidenziano che il 40% delle madri e il 75% dei padri dei bambini nati pretermine rientra nella fascia ad alto rischio del CARE-Index (che richiede un trattamento psicologico e/o farmacologico). In tali casi, la scarsa sensibilità diadica, i precursori di attaccamento insicuro e le difficoltà psicologiche dei genitori sembrano influenzare lo sviluppo psicomotorio del bambino

The evolution of bits and bottlenecks in a scientific workflow trying to keep up with technology: Accelerating 4D image segmentation applied to nasa data

In 2016, a team of earth scientists directly engaged a team of computer scientists to identify cyberinfrastructure (CI) approaches that would speed up an earth science workflow. This paper describes the evolution of that workflow as the two teams bridged CI and an image segmentation algorithm to do large scale earth science research. The Pacific Research Platform (PRP) and The Cognitive Hardware and Software Ecosystem Community Infrastructure (CHASE-CI) resources were used to significantly decreased the earth science workflow's wall-clock time from 19.5 days to 53 minutes. The improvement in wall-clock time comes from the use of network appliances, improved image segmentation, deployment of a containerized workflow, and the increase in CI experience and training for the earth scientists. This paper presents a description of the evolving innovations used to improve the workflow, bottlenecks identified within each workflow version, and improvements made within each version of the workflow, over a three-year time period

Toward the Next Generation of Sustainable Membranes from Green Chemistry Principles

Large-scale membrane technology has been widely implemented and rapidly growing for roughly 40 years. However, considering its entire life cycle, there are aspects being characterized by low sustainability, and this industry certainly cannot be defined as green. In the membrane manufacturing process, raw materials mainly rely on nonbiodegradable petroleum-based polymers and hazardous solvents. These materials are thus associated with the energy crisis and with disposal burdens at the end of their lifetime, and they pose risks to workers and the environment. Therefore, biobased polymers and green solvents should be employed within the membrane preparation process and replace traditional ones. Moreover, the wastewater generated from membrane fabrication processes contains an important amount of organic solvents and should be efficiently treated or recycled before discharge. The application of artificial intelligence in membrane manufacturing and use processes can also improve efficiency significantly. Finally, a large number of spent membrane elements should also be reused and recovered, rather than landfilled. This review critically evaluates the recent advances in methods to improve the sustainability of membrane technology, specifically emphasizing the progresses made, with regard to the above aspects. This review thus analyzes the needs for membrane industry transformations in the light of circular economy

Galactic periodicity and the oscillating G model

We consider the model involving the oscillation of the effective gravitational constant that has been put forward in an attempt to reconcile the observed periodicity in the galaxy number distribution with the standard cosmological models. This model involves a highly nonlinear dynamics which we analyze numerically. We carry out a detailed study of the bound that nucleosynthesis imposes on this model. The analysis shows that for any assumed value for $\Omega$ (the total energy density) one can fix the value of $\Omega_{\rm bar}$ (the baryonic energy density) in such a way as to accommodate the observational constraints coming from the $^4{\rm He}$ primordial abundance. In particular, if we impose the inflationary value $\Omega=1$ the resulting baryonic energy density turns out to be $\Omega_{\rm bar}\sim 0.021$. This result lies in the very narrow range $0.016 \leq \Omega_{\rm bar} \leq 0.026$ allowed by the observed values of the primordial abundances of the other light elements. The remaining fraction of $\Omega$ corresponds to dark matter represented by a scalar field.Comment: Latex file 29 pages with no figures. Please contact M.Salgado for figures. A more careful study of the model appears in gr-qc/960603

Non-Gaussian bubbles in the sky

We point out a possible generation mechanism of non-Gaussian bubbles in the sky due to bubble nucleation in the early universe. We consider a curvaton scenario for inflation and assume that the curvaton field phi, whose energy density is subdominant during inflation but which is responsible for the curvature perturbation of the universe, is coupled to another field sigma which undergoes false vacuum decay through quantum tunneling. For this model, we compute the skewness of the curvaton fluctuations due to its interaction with sigma during tunneling, that is, on the background of an instanton solution that describes false vacuum decay. We find that the resulting skewness of the curvaton can become large in the spacetime region inside the bubble. We then compute the corresponding skewness in the statistical distribution of the cosmic microwave background (CMB) temperature fluctuations. We find a non-vanishing skewness in a bubble-shaped region in the sky. It can be large enough to be detected in the near future, and if detected it will bring us invaluable information about the physics in the early universe.Comment: 6 pages, 6 figure