Design and Development of Flow Fields with Multiple Inlets or Outlets in Vanadium Redox Flow Batteries

In vanadium redox flow batteries, the flow field geometry plays a dramatic role on the distribution of the electrolyte and its design results from the trade-off between high battery performance and low pressure drops. In the literature, it was demonstrated that electrolyte permeation through the porous electrode is mainly regulated by pressure difference between adjacent channels, leading to the presence of under-the-rib fluxes. With the support of a 3D computational fluid dynamic model, this work presents two novel flow field geometries that are designed to tune the direction of the pressure gradients between channels in order to promote the under-the-rib fluxes mechanism. The first geometry is named Two Outlets and exploits the splitting of the electrolyte flow into two adjacent interdigitated layouts with the aim to give to the pressure gradient a more transverse direction with respect to the channels, raising the intensity of under-therib fluxes and making their distribution more uniform throughout the electrode area. The second geometry is named Four Inlets and presents four inlets located at the corners of the distributor, with an interdigitated-like layout radially oriented from each inlet to one single central outlet, with the concept of reducing the heterogeneity of the flow velocity within the electrode. Subsequently, flow fields performance is verified experimentally adopting a segmented hardware in symmetric cell configuration with positive electrolyte, which permits the measurement of local current distribution and local electrochemical impedance spectroscopy. Compared to a conventional interdigitated geometry, both the developed configurations permit a significant decrease in the pressure drops without any reduction in battery performance. In the Four Inlets flow field the pressure drop reduction is more evident (up to 50%) due to the lower electrolyte velocities in the feeding channels, while the Two Outlets configuration guarantees a more homogeneous current density distribution

Narrativa e violência: a cobertura do Outono Brasileiro no Twitter

O artigo analisa a cobertura dos protestos que aconteceram no Brasil em Junho de 2013. Para tanto, monitoramos 2282 tweets de dez veículos jornalísticos brasileiros que cobriram os protestos e, através de uma análise de conteúdo, comparamos e identificamos mensagens com enfoque na violência gerada pelos protestos. Também comparamos esse discurso aos dados oficiais divulgados pelos veículos jornalísticos a respeito de mortos, feridos e presos em 268 protestos ocorridos no período. Os resultados indicam que a cobertura da imprensa no Twitter é bastante divergente daquela das fontes oficiais, amplificando a violência por focar sobretudo neste tópico.This paper analyses the media coverage of the Brazilian protests that happened in June 2013. We monitored 2,852 tweets from ten news organizations and newspapers that were covering the events on Twitter and, based on content analysis, we compared and identified messages focusing on violence aspects of the manifestations. We also compared this discourse to official data from 268 protests that occurred during the same timeframe, regarding deaths, injuries and arrests. Our results indicate that news coverage on Twitter diverged from official sources, amplifying the violence discourse by focusing tweets’ contents on this topic

ADVANCED PLANNING SYSTEMS (APS) FOR SUPPLY CHAIN PLANNING: A CASE STUDY IN DAIRY INDUSTRY

This paper discusses which benefits the use of APS may bring to the S&OP, and the critical factors for the successful implementation. A case study was conducted in a major dairy company in the Brazilian food industry. Positioned in an environment of high market competition and narrow profit margins, the company strives for operational excellence, aimed at inventory reduction and increased service level. This supply chain includes several plants and has recently been through the deployment of an APS to support its S&OP process. The research has identified the main benefits of the APS: greater confidence and accuracy in planning, and better balancing of inventory throughout the supply chain. The deployment project went through specific difficulties that delayed its schedule. The study reinforces the importance of fully support from senior managers and the commitment of the planning staff to meet the challenges of customization and integration of the new system

Encontros E Desencontros Entre Tar E Ars: O Laço Fraco Entre Teoria E Método //Agreeing To Disagree On Ant And Sna: The Weak Tie Between Theory And Method

Esse artigo identifica e explora os problemas fundamentais na associação dos métodos de Análise de Redes Sociais (ARS) com a Teoria Ator-Rede (TAR). As primeiras três seções do artigo contextualizam o paradigma de pesquisa em comunicação voltado às redes e descrevem o desenvolvimento histórico do campo da análise de rede e da teoria ator-rede. As duas últimas seções do artigo debatem os problemas teóricos e metodológicos resultantes do emprego de métodos empíricos da análise de rede dentro do quadro teórico construtivista da teoria ator-rede. O artigo oferece um panorama sobre os limites da junção dessas duas abordagens e indica os pontos críticos que requerem atenção por parte dos pesquisadores da área. O artigo termina com uma descrição dos desafios e oportunidade para pesquisadores das ciências humanas e sociais dedicados à análise de redes de uma perspectiva teórica ou empírica

The Discourse of #ProtestosBR: content analysis of Twitter

This paper focus on an analysis of the discourse of Twitter messages during the protests in Brazil during June 2013. Our objective is to discuss how the concepts relate to each other and form networks of meanings around the tweets about the protests. Our search for common characteristics and elements reveals how Twitter was used to describe the protests and to mobilize people rather than to discuss what was actually taking place. We describe the key actors, contexts and demands,as well as the focus on live narratives, #pamphleteer hashtags, and the specific location of tweets

DNA methylation analysis of the tumor suppressor gene CDKN2B in Brazilian leukemia patients

The aim of this work was to evaluate the methylation profile of the p15 (CDKN2B) gene in Brazilian patients with leukemia and to correlate the CDKN2B gene expression with the percentage of methylated CpG dinucleotides in its promoter region. Thirty-one samples from six patients with acute lymphocytic leukemia (ALL), four with chronic myeloid leukemia (CML), and 21 with acute myeloid leukemia (AML) were evaluated by MSP (Methylation-Specific PCR). The CDKN2B gene was found to be methylated in four (67%) of the six ALL samples and in 16 (76%) of the 21 AML samples, but in none of the four CML samples analyzed. We observed a correlation between the CDKN2B mRNA expression (RT-PCR) and the percentage of methylated CpG dinucleotides. Therefore, this study in Brazilian patients confirms that the CDKN2B gene is methylated in the majority of leukemia patients

Low-Intensity Whole-Body Vibration: A Useful Adjuvant in Managing Obesity? A Pilot Study

The use of whole-body vibration (WBV) for therapeutic purposes is far from being stan- dardized and an empirical foundation for reporting guidelines for human WBV studies has only very recently been published. Controversies about safety and therapeutic dosage still exist. The present study aimed to investigate the metabolic and mechanical effects of low-intensity WBV according to the ISO 2631 norm on subjects with obesity. Forty-one obese subjects (BMI ≥35 kg/m2) were recruited to participate in a 3-week multidisciplinary inpatient rehabilitation program including fitness training and WBV training. During WBV the posture was monitored with an optoelectronic system with six infrared cameras (Vicon, Vicon Motion System, Oxford, UK). The primary endpoints were: variation in body composition, factors of metabolic syndrome, functional activity (sit-to-stand and 6-min walking test), muscle strength, and quality of life. The secondary endpoints were: mod- ification of irisin, testosterone, growth hormone, IGF1 levels. We observed significant changes in salivary irisin levels, Group 2 (p < 0.01) as compared to the control group, while muscle strength, function, and other metabolic and hormonal factors did not change after a 3-week low-intensity WBV training with respect to the control group. Future studies are needed to further investigate the potential metabolic effect of low-intensity WBV in managing weight