Bar pattern speed evolution over the last 7 Gyr

The tumbling pattern of a bar is the main parameter characterising its dynamics. From numerical simulations, its evolution since bar formation is tightly linked to the dark halo in which the bar is formed through dynamical friction and angular momentum exchange. Observational measurements of the bar pattern speed with redshift can restrict models of galaxy formation and bar evolution. We aim to determine, for the first time, the bar pattern speed evolution with redshift based on morphological measurements. We have selected a sample of 44 low inclination ringed galaxies from the SDSS and COSMOS surveys covering the redshift range 0 <z< 0.8 to investigate the evolution of the bar pattern speed. We have derived morphological ratios between the deprojected outer ring radius (R_{ring}) and the bar size (R_{bar}). This quantity is related to the parameter {\cal R}=R_{CR}/R_{bar} used for classifiying bars in slow and fast rotators, and allow us to investigate possible differences with redshift. We obtain a similar distribution of $R$ at all redshifts. We do not find any systematic effect that could be forcing this result. The results obtained here are compatible with both, the bulk of the bar population (~70%) being fast-rotators and no evolution of the pattern speed with redshift. We argue that if bars are long-lasting structures, the results presented here imply that there has not been a substantial angular momentum exchange between the bar and halo, as predicted by numerical simulations. In consequence, this might imply that the discs of these high surface-brightness galaxies are maximal.Comment: Accepted for publication in A&

A Model for Productivity and Systemic Quality for Systems Development Process

Many authors in the manufacturing industry have affirmed that high quality levels promote high productivity levels . How is it possible to verify this affirmation for the IT sector? How to relate both concepts for the IT sector in a systemic way? The goal of this paper is to establish an initial version of a Characterization Model for the Systemic Quality and Productivity relationship in development systems; based on the Process Effectiveness and/or Efficiency, which is related to the Systemic Quality and Productivity concepts. This model allows the IT sector to access a tool for indicating the expected balance between quality and productivity levels in the development systems process in order to achieve increased market competitiveness. A model was the most important result of this research, which confirmed the initial premise: to offer a quality product with cost reduction it is necessary to increase productivity and strengthen the development process

Issues for Evaluating Reliability in Software Architectures

Currently, the requirements of Business sector promote more and more complex Information Systems. Reliability is one of the quality characteristics widely expected by users and developers. This characteristic is architectural by nature since it can be directly promoted by software architecture. This relation determines the importance of designing architectures that guarantee reliable systems. This article presents a research in progress whose objective is developing an architectural evaluation method based on Reliability. The first step considered for designing the method included: the construction of a Conceptual Model, a model to specify the architectural quality based on Reliability (Utility Tree), a set of scenarios associated to this characteristic. The first model allows identifying the concepts inherent to Reliability and their relationships; the second one covers all quality features related to Reliability in order to specify it; and the scenarios guide the software architect for anticipating context stimulus and evaluating the architectural responses

Perspectives on Quantum Gravity Phenomenology

The idea that quantum gravity manifestations would be associated with a violation of Lorentz invariance is very strongly bounded and faces serious theoretical challenges. Other related ideas seem to be drowning in interpretational quagmires. This leads us to consider alternative lines of thought for such phenomenological search. We discuss the underlying viewpoints and briefly mention their possible connections with other current theoretical ideas.Comment: Latex, 23 page

Lactic acid production a bibliometric study

Bibliometrics is a documentary analysis tool that is positioning itself as a support to know and understand the study status of a specific topic. In this case, the VOSviewer software was used to determine the evolution of lactic acid production, carried out through a programmed search with the VOSviewer application, which allowed a clear and reliable bibliographic review for the topic development under study, which made possible to obtain enough material to know who, where and in what year have published about the latest advances in the production of lactic acid. The database used was Scopus, with the search equation “lactic acid” and production and “natural sources”

Design and Implementation of the Financing Product Management System of the Subscribing for the Open-Ended New Stock of Bank

本研究课题属于银行理财产品申购应用领域，开发基于本地特色业务平台的理财产品管理系统。随着市场的发展人们对开放式新股的申购也跃跃欲试，都想通过申购开放式新购来获取更大的利润。目前我国商业银行已将各项理财产品的经营列为了各年度战略重点发展业务，可见理财产品的经营作为商业银行增加自身中间业务收入的重要性。 为了能够适应竞争日益激烈的市场需求，我们结合银行自身特点自主开发了“银行开放式新股申购类理财产品管理系统”。论文首先充分以现有的本地特色平台作为基础，提出了新股申购的解决方案。在此基础上分析了各功能模块的需求及设计实现技术，然后采用C开发语言，根据本系统在本地特色业务平台中所处的位置确定系统的设...This research topic belongs to the bank to manage finances product purchase in the application domain, develops manages finances the product management system based on the local characteristic service platform. Develops the people along with the market to buy to open style new stock Shanghai is also eager to try, all wants to buy open style through Shanghai buys newly gains a bigger profit. At pre...学位：工程硕士院系专业：软件学院_工程硕士(软件工程)学号：X200923020

Stellar Population gradients in galaxy discs from the CALIFA survey

While studies of gas-phase metallicity gradients in disc galaxies are common, very little has been done in the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. Contrary to this, the values of both age and metallicity at $\sim$2.5 scale-lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients in galaxies with without bars. We discuss possible scenarios that can lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&

Imprints of galaxy evolution on H ii regions Memory of the past uncovered by the CALIFA survey

H ii regions in galaxies are the sites of star formation and thus particular places to understand the build-up of stellar mass in the universe. The line ratios of this ionized gas are frequently used to characterize the ionization conditions. We use the Hii regions catalogue from the CALIFA survey (~5000 H ii regions), to explore their distribution across the classical [OIII]/Hbeta vs. [NII]/Halpha diagnostic diagram, and how it depends on the oxygen abundance, ionization parameter, electron density, and dust attenuation. We compared the line ratios with predictions from photoionization models. Finally, we explore the dependences on the properties of the host galaxies, the location within those galaxies and the properties of the underlying stellar population. We found that the location within the BPT diagrams is not totally predicted by photoionization models. Indeed, it depends on the properties of the host galaxies, their galactocentric distances and the properties of the underlying stellar population. These results indicate that although H ii regions are short lived events, they are affected by the total underlying stellar population. One may say that H ii regions keep a memory of the stellar evolution and chemical enrichment that have left an imprint on the both the ionizing stellar population and the ionized gasComment: 18 pages, 8 figures, accepted for publishing in A&