Overlooked examples of cloud self-organization at the mesoscale

Stratocumulus clouds are common in the tropical and subtropical marine boundary layer, and understanding these clouds is important due to their significant impact on the earth's radiation budget. Observations show that the marine boundary layer contains complex, but poorly understood processes, which, from time to time, result in the observable self-organization of cloud structures at scales ranging from a few to a few thousand kilometers. Such shallow convective cloud features, typically observed as hexagonal cells, are known generally as mesoscale cellular convection (MCC). Actinoform clouds are rarer, but visually more striking forms of MCC, which possess a radial structure. Because mesoscale cloud features are typically too large to be observed from the ground, observations of hexagonal cells historically date only to the beginning of satellite meteorology. Examples of actinoform clouds were shown in the venerable “Picture of the Month” series in Monthly Weather Review in the early 1960s, but these clouds were generally forgotten as research focused on hexagonal cells. Recent high-resolution satellite images have, in a sense, “rediscovered” actinoform clouds, and they appear to be much more prevalent than had been previously suspected. We show a number of examples of actinoform clouds from a variety of locations worldwide. In addition, we have conducted a detailed case study of an actinoform cloud system using data from the Multiangle Imaging SpectroRadiometer (MISR) and the Geostationary Operational Environmental Satellite (GOES), including analysis of cloud heights, radiative properties, and the time-evolution of the cloud system. We also examine earlier theories regarding actinoform clouds in light of the new satellite data

Assessing molecular outflows and turbulence in the protostellar cluster Serpens South

Molecular outflows driven by protostellar cluster members likely impact their surroundings and contribute to turbulence, affecting subsequent star formation. The very young Serpens South cluster consists of a particularly high density and fraction of protostars, yielding a relevant case study for protostellar outflows and their impact on the cluster environment. We combined CO $J=1-0$ observations of this region using the Combined Array for Research in Millimeter-wave Astronomy (CARMA) and the Institut de Radioastronomie Millim\'{e}trique (IRAM) 30 m single dish telescope. The combined map allows us to probe CO outflows within the central, most active region at size scales of 0.01 pc to 0.8 pc. We account for effects of line opacity and excitation temperature variations by incorporating $^{12}$CO and $^{13}$CO data for the $J=1-0$ and $J=3-2$ transitions (using Atacama Pathfinder Experiment and Caltech Submillimeter Observatory observations for the higher CO transitions), and we calculate mass, momentum, and energy of the molecular outflows in this region. The outflow mass loss rate, force, and luminosity, compared with diagnostics of turbulence and gravity, suggest that outflows drive a sufficient amount of energy to sustain turbulence, but not enough energy to substantially counter the gravitational potential energy and disrupt the clump. Further, we compare Serpens South with the slightly more evolved cluster NGC 1333, and we propose an empirical scenario for outflow-cluster interaction at different evolutionary stages.Comment: 26 pages, 15 figures, accepted for publication in the Astrophysical Journa

Minimum Length from Quantum Mechanics and Classical General Relativity

We derive fundamental limits on measurements of position, arising from quantum mechanics and classical general relativity. First, we show that any primitive probe or target used in an experiment must be larger than the Planck length, $l_P$. This suggests a Planck-size {\it minimum ball} of uncertainty in any measurement. Next, we study interferometers (such as LIGO) whose precision is much finer than the size of any individual components and hence are not obviously limited by the minimum ball. Nevertheless, we deduce a fundamental limit on their accuracy of order $l_P$. Our results imply a {\it device independent} limit on possible position measurements.Comment: 8 pages, latex, to appear in the Physical Review Letter

Diseño de un sistema de gestión ambiental, de seguridad y salud en el trabajo para una empresa metalmecánica

La investigación se llevó a cabo en una empresa metalmecánica brinda productos y servicios como, la fabricación y montaje de estructuras metálicas respectivamente, la cual consiste en procesar la materia prima (metal) hasta llegar a la forma y diseño especifico o requerido por el cliente, en la cual se desarrollan trabajos de alto riesgo (izaje de cargas, trabajos en altura, caliente, y con energía o sustancias peligrosas) para la fabricación del producto o bien final así como también la generación de residuos (peligrosos y no peligrosos), lo que puede generar impactos ambientales negativos y accidentes laborales sino se tiene una adecuada gestión. Por ello el propósito de la presente investigación fue implementar y demostrar los beneficios de contar con Sistema de Gestión para lo cual se utilizó como base a las normas OHSAS 18001, ISO 14001, la Ley 29783 y su reglamento D.S. N° 005- 2012-TR. El proceso de implementación se realizó siguiendo el ciclo de Deming o PHVA, el cual consistió de 4 fases (Diagnostico, planificación, implementación y seguimiento, proceso de auditorías). La fase de diagnóstico se ejecutó con el objetivo de verificar el estado del sistema de gestión, en la fase de planificación se desarrolló las acciones a tomar en base el diagnóstico inicial realizado así como también el proceso de capacitación y sensibilización. En la fase de implementación y seguimiento se desplego todo lo planificado en la fase anterior (controles operacionales, comité de SST, comunicación, participación y consulta entre otros elementos) así como también se elaboró indicadores para evaluar el desempeño en la gestión de seguridad, salud y medio ambiente. En la última fase se realizó el proceso de auditorías para verificar el nivel de cumplimiento del sistema de gestión y encontrar oportunidades de mejora que permitan que el sistema de gestión desarrolle un enfoque de mejora continua en sus procesos. La implementación del Sistema de Gestión Ambiental, de Seguridad y Salud en el Trabajo obtuvo resultados positivos en la empresa metalmecánica (empresa en estudio), obteniendo beneficios económicos, de reconocimiento interno (corporación y accionistas) y externo (clientes) por la mejora mostrado en los indicadores y resultado de auditorías y homologaciones

Determinación del periodo de retiro de enrofloxacina durante una crianza de cuyes (Cavia porcellus)

Determina el periodo de retiro de enrofloxacina durante una crianza de cuyes (Cavia porcellus) en el distrito de Maranganí (Canchis - Cusco). Para ello, se utilizaron 51 cuyes (25 hembras y 26 machos) de la raza Perú. Los animales fueron administrados con enrofloxacina al 10%, vía oral, a razón de 10 mg/kg (0.1 ml/kg PV) cada 24 horas por un periodo de 10 días. Inmediatamente después de la última administración del antibiótico, fueron seleccionados aleatoriamente tres animales para su beneficio cada dos horas, desde las cero hasta las 32 horas post retiro del fármaco, tomándose muestras del músculo diafragma para la detección de la enrofloxacina. El análisis y cuantificación de los residuos del antibiótico se realizó empleando el Kit comercial ELISA (Max Signal®) específico para enrofloxacina. La concentración máxima de enrofloxacina en carne de cuy (1425 ± 53.4 μg/kg) se determinó a las 12 horas después de la última administración del fármaco. Posteriormente, las concentraciones del metabolito descendieron, siendo de 80.8 ± 6 μg/kg a las 28 h, valor por debajo de 100 μg/kg que se podría considerar como un límite de referencia para la carne de animales de abasto. Bajo las condiciones de este estudio, se sugiere un periodo de retiro de dos días para el cuy tratado con enrofloxacina.Perú. Universidad Nacional Mayor de San Marcos. Vicerrectorado de Investigación y Posgrado. Programa de Promoción de Tesis de Pregrado. E18030044-PTPGRADO

A graphical tool for event refinement structures in Event-B

The Event Refinement Structures (ERS) approach provides a graphical extension of the Event-B formal method to represent event decomposition and control-flow explicitly. In this paper we present an improved version of the ERS plug-in, which provides a graphical environment for the ERS approach within the Event-B tool, Rodin. The improved ERS plug-in is based on the available frameworks that are developed to support Event-B with an EMF framework, language extensions and generic diagram extensions

ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow: Structure, Entrainment and Core Impact

We present ALMA Cycle 1 observations of the HH46/47 molecular outflow using combined 12m array and ACA observations. The improved angular resolution and sensitivity of our multi-line maps reveal structures that help us study the entrainment process in much more detail and allow us to obtain more precise estimates of outflow properties than previous observations. We use 13CO(1-0) and C18O(1-0) emission to correct for the 12CO(1-0) optical depth to accurately estimate the outflow mass, momentum and kinetic energy. This correction increases the estimates of the mass, momentum and kinetic energy by factors of about 9, 5 and 2, respectively, with respect to estimates assuming optically thin emission. The new 13CO and C18O data also allow us to trace denser and slower outflow material than that traced by the 12CO maps, and they reveal an outflow cavity wall at very low velocities (as low as 0.2km/s with respect to the cores central velocity). Adding with the slower material traced only by 13CO and C18O, there is another factor of 3 increase in the mass estimate and 50% increase in the momentum estimate. The estimated outflow properties indicate that the outflow is capable of dispersing the parent core within the typical lifetime of the embedded phase of a low-mass protostar, and that it is responsible for a core-to-star efficiency of 1/4 to 1/3. We find that the outflow cavity wall is composed of multiple shells associated with a series of jet bow-shock events. Within about 3000AU of the protostar the 13CO and C18O emission trace a circumstellar envelope with both rotation and infall motions, which we compare with a simple analytic model. The CS(2-1) emission reveals tentative evidence of a slowly-moving rotating outflow, which we suggest is entrained not only poloidally but also toroidally by a disk wind that is launched from relatively large radii from the source.Comment: Accepted for publication in ApJ. 26 pages, 20 figure

Aerosol Optical Depths over Oceans: a View from MISR Retrievals and Collocated MAN and AERONET in Situ Observations

In this study, aerosol optical depths over oceans are analyzed from satellite and surface perspectives. Multiangle Imaging SpectroRadiometer (MISR) aerosol retrievals are investigated and validated primarily against Maritime Aerosol Network (MAN) observations. Furthermore, AErosol RObotic NETwork (AERONET) data from 19 island and coastal sites is incorporated in this study. The 270 MISRMAN comparison points scattered across all oceans were identified. MISR on average overestimates aerosol optical depths (AODs) by 0.04 as compared to MAN; the correlation coefficient and root-mean-square error are 0.95 and 0.06, respectively. A new screening procedure based on retrieval region characterization is proposed, which is capable of substantially reducing MISR retrieval biases. Over 1000 additional MISRAERONET comparison points are added to the analysis to confirm the validity of the method. The bias reduction is effective within all AOD ranges. Setting a clear flag fraction threshold to 0.6 reduces the bias to below 0.02, which is close to a typical ground-based measurement uncertainty. Twelve years of MISR data are analyzed with the new screening procedure. The average over ocean AOD is reduced by 0.03, from 0.15 to 0.12. The largest AOD decrease is observed in high latitudes of both hemispheres, regions with climatologically high cloud cover. It is postulated that the screening procedure eliminates spurious retrieval errors associated with cloud contamination and cloud adjacency effects. The proposed filtering method can be used for validating aerosol and chemical transport models

A Quantitative Validation of Multi-Modal Image Fusion and Segmentation for Object Detection and Tracking

In previous works, we have shown the efficacy of using Deep Belief Networks, paired with clustering, to identify distinct classes of objects within remotely sensed data via cluster analysis and qualitative analysis of the output data in comparison with reference data. In this paper, we quantitatively validate the methodology against datasets currently being generated and used within the remote sensing community, as well as show the capabilities and benefits of the data fusion methodologies used. The experiments run take the output of our unsupervised fusion and segmentation methodology and map them to various labeled datasets at different levels of global coverage and granularity in order to test our models’ capabilities to represent structure at finer and broader scales, using many different kinds of instrumentation, that can be fused when applicable. In all cases tested, our models show a strong ability to segment the objects within input scenes, use multiple datasets fused together where appropriate to improve results, and, at times, outperform the pre-existing datasets. The success here will allow this methodology to be used within use concrete cases and become the basis for future dynamic object tracking across datasets from various remote sensing instruments