A kiloparsec-scale nuclear stellar disk in the milky way as a possible explanation of the high velocity peaks in the galactic bulge

The Apache Point Observatory Galactic Evolution Experiment has measured the stellar velocities of red giant stars in the inner Milky Way. We confirm that the line of sight velocity distributions (LOSVDs) in the mid-plane exhibit a second peak at high velocities, whereas those at | b| =2^\circ do not. We use a high resolution simulation of a barred galaxy, which crucially includes gas and star formation, to guide our interpretation of the LOSVDs. We show that the data are fully consistent with the presence of a thin, rapidly rotating, nuclear disk extending to ∼1 kpc. This nuclear disk is orientated perpendicular to the bar and is likely to be composed of stars on x2 orbits. The gas in the simulation is able to fall onto such orbits, leading to stars populating an orthogonal disk

The Emergent Vinifera Wine Industry in North Carolina: A Descriptive Overview

The North Carolina (NC) wine industry has grown rapidly over the past decade and is expected to grow even more as the worldwide wine consumption and export of wines rises. In the United States, the wine market has grown by 13.7 percent since 2002 in volume and by more than 15 percent in dollars as wine has progressed from being a beverage of an elite segment of the market to becoming a mainline beverage, taking its place alongside beer and liquor (MKF Research LLC, 2007; Oches, 2009). The Piedmont Triad Region is uniquely positioned to increase its presence in this industry. Of the 80 wineries in NC that are currently open to the public, nearly half are located in the Piedmont Triad Region. However, growing grapes and making wine is a long term commitment to a community, both financially and physically. The MKF Research report states that the capital-intensive nature of the winery and vineyard sectors is often underestimated, with new entrants to the industry at times unprepared for the extended cash requirements. In addition, only a few local institutions are familiar with the unique needs of the winemaking business. In order to address factors that will impede growth in this nascent industry, it is important to identify the state of the industry and obtain management perspectives on the needs and challenges facing their operations. This study provides information that would help gain a better understanding of the business issues and needs related to the wine and grape industry in North Carolina. Data for this study was drawn from a census of 34 wine producers located in the Yadkin, Swan Creek, and the Haw River valley regions of North Carolina. Descriptive statistics using frequencies and means is used to provide a demographic overview of the industry and to identify the factors that wine producers perceive to be important in affecting their profitability. Results from the study shows that most of the wineries share some common traits: they are small, relatively new to the wine and grape industry and grow grapes other than the traditional native Muscadine grape. Primarily, a majority of the wineries are family-based entrepreneurial businesses that have to behave like mini-conglomerates. These findings are consistent with a study conducted by Taplin and Breckenridge (2008).Profitability Constraints, Financial Management, Marketing, Distribution, Agribusiness, Community/Rural/Urban Development, Farm Management,

Predicted Stellar Kinematics of a Kiloparsec-Scale Nuclear Disc (or Ring) in the Milky Way

In Debattista et al. (2015), we proposed that a kiloparsec-scale nuclear disc is responsi- ble for the high-velocity secondary peak in the stellar line-of-sight velocity distributions (LOSVDs) seen at positive longitudes in the bulge by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). Here, we make further qualitative but distinctive predictions of the kinematic properties of a nuclear disc, including for the LOSVDs at negative longitudes (which APOGEE-2 will observe) and examine the proper motions throughout the disc. Since a nuclear ring is also able to produce similar high-velocity LOSVD peaks, we present predictions for the proper motion signatures which distinguish between a nuclear disc and a nuclear ring. We also demonstrate that the stars in a nuclear disc, which would be on x2 orbits perpendicular to the bar, can remain on these orbits for a long time and can therefore be old. We show that such (old) nuclear discs of comparable size exist in external galaxies

The tilting rate of the Milky Way's disc

We present tilting rates for galaxies comparable to the Milky Way (MW) in a Λ cold dark matter cosmological hydrodynamical simulation, and compare these with the predicted tilting rate detection limit of the Gaia satellite 0.28° Gyr−1. We first identify galaxies with mass comparable to the MW (9 × 1011 ≤ M200 ≤ 1.2 × 1012 M⊙) and consider the tilting rates between z = 0.3 and 0. This sample yields a tilting rate of 7.6° ± 4.5° Gyr−1. We constrain our sample further to exclude any galaxies that have high stellar accretion during the same time. We still find significant tilting, with an average rate of 6.3° Gyr−1. Both subsamples tilt with rates significantly above Gaia's predicted detection limit. We show that our sample of galaxies covers a wide range of environments, including some similar to the MW's. We find galaxies in denser regions tilt with higher rates then galaxies in less dense regions. We also find correlations between the angular misalignment of the hot gas corona and the tilting rate. Gaia is likely to be able to directly measure tilting in the MW. Such a detection will provide an important constraint on the environment of the MW, including the rate of gas cooling on to the disc, the shape and orientation of its dark matter halo, and the mass of the Large Magellanic Cloud. Conversely, failure to detect tilting may suggest the MW is in a very quiet configuration

Modelling stress-diffusion controlled phase transformations : application to stress corrosion cracking

National audienceStress Corrosion Cracking (SCC) represents a significant cause of failure in pressurised water reactors and many efforts have been made to address this problem [1]. It involves the combined action of the environment, mechanical stresses and material properties on the damage of engineering components. Current SCC models developed to predict crack growth behaviour or SCC susceptibility criteria do not fully incorporate the complex multiphysical processes that occur during oxidation at the scale of the microstructure. The aim of the work is to formulate a multi-physics modelling framework based on continuum thermodynamics able to describe the growth of an oxide film on a polycrystalline material using the phase field method

The formation of stellar nuclear discs in bar-induced gas inflows

The role of gas in the mass assembly at the nuclei of galaxies is still subject to some uncertainty. Stellar nuclear discs bridge the gap between the large-scale galaxy and the central massive objects that reside there. Using a high-resolution simulation of a galaxy forming out of gas cooling and settling into a disc, we study the formation and properties of nuclear discs. Gas, driven to the centre by a bar, settles into a rotating star-forming nuclear disc (ND). This ND is thinner, younger, kinematically cooler and more metal rich than the surrounding bar. The ND is elliptical and orthogonal to the bar. The complex kinematics in the region of the ND are a result of the superposition of older stars streaming along the bar and younger stars circulating within the ND. The signature of the ND is therefore subtle in the kinematics. Instead the ND stands out clearly in metallicity and age maps. We compare the model to the density and kinematics of real galaxies with NDs finding qualitative similarities. Our results suggest that gas dissipation is very important for forming nuclear structure

Nigerian indigenous hens show more discomfort-related behavior with visual separation than physical separation from their chicks: An exploratory study

The Nigerian indigenous hens exhibit their full natural behavior repertoires, including maternal care. The strong maternal bond between the hen and her chicks is established prior to hatching. Maternal care of chickens is essential for both exotic and indigenous chickens. This study compared the behaviors of six hen-chick pairs in a physical (PHY) and visual (VIS) separation test for 10 min. All the six hen-chick pairs were subjected to PHY separation on the 8th day of post-hatch and a VIS separation on the 12th day of post-hatch. The PHY separation involved the use of a wire mesh to separate the hen from her chicks, while the VIS separation involved the use of a trampoline to separate the hen from her chicks. The hen's behavior was recorded during the 10-min separation period. Behaviors recorded included sitting, body shaking, pecking, movements toward the chicks, jumping, pacing, defecation, movements away from the chicks, and preening. We further grouped these nine behaviors into two categories: discomfort-related (pacing, movement toward chicks, body shaking, defecation, and jumping) and comfort-related (sitting, pecking, preening, and movement away from the chicks) behaviors. Before and after each separation, the hens were gently restrained, and a drop of blood was sampled from the wing vein to determine the blood glucose level. Their heart rate and eye temperature were also measured. A two-related samples test (Wilcoxon) was used to compare the behavior of the hens when subjected to the PHY and VIS separation. Eight out of the nine behaviors monitored did not differ between the separation types. However, the frequency of pacing by the hens was greater (z = −2.201, P = 0.028) in the VIS separation than in the PHY separation. Also, discomfort-related behavior was greater (t(5) = −2.717, P = 0.042) during the VIS separation than the PHY separation. Comfort-related behavior did not differ between the separation types. The change in eye temperature, heart rate, and blood glucose was similar in the two separation types. In conclusion, Nigerian indigenous hens displayed more discomfort-related behavior to the VIS separation from their chicks, but this was not associated with physiological responses indicative of stress.Peer Reviewe

Energy production predication via Internet of Thing based machine learning system

© 2019 Elsevier B.V. Wind energy is an interesting source of alternative energy to complement the Brazilian energy matrix. However, one of the great challenges lies in managing this resource, due to its uncertainty behavior. This study addresses the estimation of the electric power generation of a wind turbine, so that this energy can be used efficiently and sustainable. Real wind and power data generated in set of wind turbines installed in a wind farm in Ceará State, Brazil, were used to obtain the power curve from a wind turbine using logistic regression, integrated with Nonlinear Autoregressive neural networks to forecast wind speeds. In our system the average error in power generation estimate is of 29 W for 5 days ahead forecast. We decreased the error in the manufacturer\u27s power curve in 63%, with a logics regression approach, providing a 2.7 times more accurate estimate. The results have a large potential impact for the wind farm managers since it could drive not only the operation and maintenance but management level of energy sells