RESUMO O objetivo desta pesquisa foi verificar quais comportamentos táticos podem predizer a eficiência defensiva de jogadores de futebol de elite. A amostra foi composta por 533 sequências defensivas de seleções semifinalistas da Copa do Mundo FIFA 2014. Foi construído um instrumento ad-hoc com as variáveis: “zona de recuperação da bola”, “pressão defensiva”, “redução de profundidade”, “tempo defensivo gasto”, “número de corredores ocupados”, “número de faltas cometidas” e “número de faltas sofridas”. As sequências táticas foram analisadas com o software Match Vision Studio Premium. A regressão logística multinomial foi aplicada para predizer as chances de sucesso e fracasso de ações coletivas defensivas (P < 0,05). A recuperação da bola na zona defensiva do campo teve aumento de 19 vezes das chances de finalização de gol em comparação com a zona ofensiva média (OR = 19,39; P < 0,01). Por outro lado, reduzir a profundidade defensiva resultou em diminuição de 71% das chances de fazer um gol (OR = 0,29; P < 0,01). Além disso, cada falta cometida aumentou as chances de falha na fase defensiva (OR = 5,39; P < 0,01). Os times que recuperaram a bola longe dos próprios gols e coordenaram sua última linha defensiva para deixar os atacantes em posição de impedimento tiveram sucesso na recuperação da bola. Nível de Evidência IV; Série de casos.

ABSTRACT The purpose of this research was to verify which tactical behaviors can predict defensive efficiency among elite football players. The sample was composed of 533 defensive sequences from national teams that were semifinalists in the FIFA World Cup 2014. An ad-hoc instrument was built with the variables: “ball recovery zone”, “defensive pressure”, “removing depth”, “defensive time spent”, “number of occupied corridors”, “number of fouls committed”, and “number of times fouled”. The tactical sequences were analyzed using Match Vision Studio Premium software. Multinomial logistic regression was applied to predict the chances of success and failure of collective defensive actions (P < 0.05). Recovering the ball in the defensive zone of the field had a 19-times better chance of goal completion compared to recovering the ball in the middle offensive zone (OR = 19.39; P < 0.01). On the other hand, removing defensive depth resulted in a decrease of 71% in the chances of completing a goal (OR = 0.29; P < 0.01). Moreover, every foul committed increased the chances of failure in the defensive phase (OR = 5.39; P < 0.01). Teams that recovered the ball far from their own goals and coordinated their last defensive line to leave attackers in an offside position had success in getting the ball back. Level of Evidence IV; Case series.

RESUMEN El objetivo de esta investigación fue verificar qué comportamientos tácticos pueden predecir la eficiencia defensiva entre los jugadores de fútbol de élite. La muestra estuvo compuesta por 533 secuencias defensivas de selecciones semifinalistas en la Copa Mundial de la FIFA 2014. Se construyó un instrumento ad-hoc con las variables: “zona de recuperación del balón”, “presión defensiva”, “reducción de profundidad”, “tiempo defensivo empleado”, “número de pasillos ocupados”, “número de faltas cometidas” y “número de faltas sufridas”. Las secuencias tácticas se analizaron utilizando el software Match Vision Studio Premium. Se aplicó la regresión logística multinomial para predecir las posibilidades de éxito y fracaso de las acciones colectivas defensivas (P <0,05). La recuperación del balón en las zonas defensivas del campo representó un aumento de 19 veces las posibilidades de finalización del gol en comparación con la zona ofensiva media (OR = 19,39; P <0,01). Por otro lado, eliminar la profundidad defensiva resultó en una disminución del 71% de las posibilidades de marcar un gol (OR = 0,29; P <0,01). Además, cada falta cometida aumentaba las posibilidades de falla en la fase defensiva (OR = 5,39; P <0,01). Los equipos que recuperaron el balón lejos de sus propios arcos y coordinaron su última línea defensiva para dejar a los atacantes en posición de fuera de juego, tuvieron éxito en la recuperación del balón. Nivel de Evidencia IV; Serie de casos.

Abstract Aim: The aim was to compare performance in specific-skill tests and motor coordination between groups with different technical efficiency and verify possible variables related to specific skills and motor coordination that contribute to discriminate players into high- and low-technical efficiency. Methods: The sample consisted of 82 young soccer players (12-15 years). Body size, bone age, motor performance tests, soccer-specific skill tests, and frequency of technical actions in SSG were analyzed. Statistic cluster-derived ANOVA F was used to identify which variables related to technical action most contributed to classifying subjects with similar performance. Discriminant analysis (Stepwise Method) was used to verify which predictor variables discriminated players into groups of low- and high-frequency technical actions in SSG. Statistical significance was set at 5%. Results: The group of high technical efficiency presented better performance in motor tests, shuttle run (P = 0.04; ES = −0.55), jumping laterally (P = 0.02; ES = 0.58), kicking speed (P = 0.03; ES = 0.60), soccer-specific skill tests, leading the ball in a straight line (LBSL) (P = 0.01; ES = −0.75), and zig-zag ball control (ZZBC) (P = 0.04; ES = −0.55); variable leading the ball in a straight line correctly discriminated 60% of players into high- and low-frequency groups. Conclusion: The frequency of technical actions in SSG was poorly influenced by motor performance and specific skill tests, and only the LBSL test correctly classified players of different frequencies of technical actions in SSG.

RESUMO O objetivo do presente estudo foi avaliar o efeito relativo da idade (ERI) nas seleções Brasileira de handebol que competiram nos campeonatos mundiais das categorias Sub-19, Sub-21 e Adulta. A amostra foi composta por 160 jogadores de handebol do sexo masculino, sendo 47 pertencentes a categoria Sub-19, 48 a Sub-21 e 65 a Adulta. A idade cronológica, massa corporal, estatura e posição de jogo de cada atleta foram obtidas no site oficial da Federação Internacional de Handebol. O nível de significância adotado foi de 5%. ERI foi observado em todas as três seguintes categorias Sub-19 (X2=21.511, P<0.01), Sub-21 (X2=15.894, P=0.01) e adulta (X2=35.123, P<0.01). Além disso, não foi encontrado ERI no processo de re-seleção pela categoria sequencial (P= 0.63, Sub-19 para Sub-21; P=0.46, Sub-21 para Adulta). O ERI foi encontrado nas seleções brasileiras de handebol. Contudo, este efeito não foi encontrado no processo de re-seleção, assim, os jogadores sofrem grande influência do ERI na categoria Sub-19 e isto permanece durante as categorias subsequentes até a equipe adulta.

ABSTRACT The aim of this study was to evaluate the relative age effect (RAE) in Brazilian male handball teams who competed in the world championships in the U-19, U-21, and adult categories. The sample was composed by 160 male handball players, 47 players being on U-19 category, 48 on U-21, and 65 on Adult category. The chronological age, body mass, height, and game position of each athlete were obtained on the International Federation of Handball website. The adopted significance level was of 5%. RAE was observed in all the three following categories U-19 (X2=21.511, P<0.01), U-21 (X2=15.894, P=0.01) and Adults (X2=35.123, P<0.01). Moreover, no RAE was found in re-selection process by sequential category (P= 0.63, U-19 to U-21; P= 0.46, U-21 to Adult). The RAE is found in Brazilian male handball national teams. However, this effect was not found in re-selection process, thus, players have great influence of RAE in U-19 and this remains through subsequent categories.

Abstract Aim: The objective of this study was to verify whether the match winners in the semifinals and finals of the FIFA World Cup 2014 were those who presented the highest frequency of pressing and intense behaviors in the recovery of ball possession. Methods: The sample was composed of 533 defensive tactical sequences performed by the four finalist teams in the 2014 FIFA World Cup. The independent t-test was used to compare tactical indicators between winning and losing teams and the chi-square test (X2) was applied to assess the association between the variables. Results: In the first (X2 = 48.47; P < 0.01) and second halves of regular matches (X2 = 64.10; P < 0.01), the evaluated teams recovered the ball in the defensive zone. However, during the first and second periods of extra time, the highest frequencies of ball recovery were found in the middle defensive zone (P < 0.01). Conclusion: It is concluded that the semi-finalist and finalist teams from the 2014 FIFA World Cup sought to recover the ball in the defensive zone, and pressing opponent movements when they were losing the matches.

Resumo O estudo objetivou analisar os princípios táticos fundamentais ofensivos e a eficácia técnica de escolares praticantes de futsal. Participaram do estudo 33 alunos de uma escola no Paraná. Utilizou-se o Sistema de Avaliação Tática no Futebol (FUT-SAT) e o Sistema de Análise Notacional em Jogos Reduzidos de Futebol para análise tático-técnica. Constatou-se que o princípio tático “cobertura ofensiva” foi executado com mais frequência pelos escolares praticantes de futsal (p = 0,01) seguido pelo princípio “espaço sem bola” (p < 0,01). Correlações significativas moderadas e fortes foram identificadas entre a frequência de execução dos princípios táticos fundamentais “penetração”, “cobertura ofensiva”, “espaço com bola”, “unidade ofensiva” e a eficiência em habilidades técnicas (de r = 0,43 a r = 0,82, p < 0,05). Conclui-se que no grupo etário avaliado, existe um modelo de jogar próximo ao centro de jogo e que a eficiência de execução técnica está associada com o comportamento tático em situação de jogo.

Abstract The study aimed to analyze the core tactical offensive principles and technical efficiency of primary school futsal players. Thirty-three students from a school in Paraná participated in the study. The System of Tactical Assessment in Soccer (FUT-SAT) and the System of Notational Analysis in Small-sided Soccer Games were used for tactical-technical analysis. It was found that the tactical principle “offensive coverage" was most frequently executed by the primary school futsal players (p = 0.01), followed by "width and length" without ball (p < 0.01). Moderate and strong significant correlations were identified between the execution frequency of the core tactical principles “penetration”, “offensive coverage”, “width and length without ball”, “offensive unity” and efficiency in technical skills (from r = 0.43 to r = 0.82, p < 0.05). It is concluded that there is a model of playing near the game center in the presented age group, and that the efficiency of executing technical skills is associated with tactical behavior in game situation.

RESUMO O estudo examinou ações táticas ofensivas realizadas por jogadores de futebol sub-15 em diferentes contextos competitivos. Foram analisados 34 jogos disputados por clubes sub-15 de três diferentes contextos competitivos, sendo estes: brasileiro nacional (BN), brasileiro regional (BR) e italiano nacional (IN). Cinco categorias foram utilizadas para analisar as ações futebolísticas ofensivas: “número de jogadores envolvidos” (NJ), “toques sobre a bola” (NT), “passes” (NP), “mudanças de corredor” (NTC) e “duração da posse de bola”. ”(TRA); os resultados foram codificados usando o software Match Vision Studio®. O BN apresentou valores maiores nas cinco categorias ofensivas (p <0,05) quando comparado ao IN. A regressão multinominal evidenciou contribuições relativas de NJ e NP nas chances de resultados no BN. O aumento de um jogador envolvido na ação ofensiva diminuiu em 84% as chances de “êxito total” em relação a “sem êxito” (p <0,05). O desempenho de cada passe adicional aumentou em 4,9 vezes a chance da jogada terminar em “êxito total” e 4,7 vezes (p <0,05) em “êxito parcial” quando comparado à categoria “sem êxito”. O NJ na ação e o NP tiveram influência direta no resultado das ações ofensivas do BN.

ABSTRACT The study examined offensive tactical actions performed by U-15 soccer players with different competitive contexts. 34 matches played by three different contexts of U-15 soccer clubs were used; brazilian national (BN), brazilian regional (BR), and italian national (IN). Five categories where used to analyze the soccer offensive actions: “number of players involved” (NJ), “ball touches” (NT), “passes” (NP), “corridor changes” (NTC), and “duration of ball possession” (TRA); the results were coded using Match Vision Studio® software. The BN presented higher values in all five offensive categories (p < 0.05) when compared to the IN. Multinomial regression evidenced relative contributions of NJ and NP on the chances of results in the BN. The increase of one player involved in the offensive action decreases by 84% the chances of “total success” with respect to “unsuccessful” (p < 0.05). The performance of each additional pass increases 4.9 times the chance of the play ending in “total success” and 4.7 times (p < 0.05) in “partial success” when compared to the “unsuccessful” category. The NJ in the action and the NP have a direct influence on the outcome of the offensive actions of the BN.

Abstract A great variety of silica and alumina-rich materials have been investigated in the production of alkaline activated binders (or geopolymers) with low environment impact, e.g. low CO2 emissions. Geopolymer mortars and concretes may be more environmentally friendly if not only Portland cement but also natural aggregates (sand, gravel) are replaced with waste materials. This article presents results of geopolymers made with tailings from the iron mining industry. The geopolymer matrices are composed of metakaolin (MK) activated with a sodium silicate + sodium hydroxide solution. Two different iron ore tailings replaced a natural quartz aggregate in the geopolymers’ formulation. The hardened properties assessed were compressive strength, water absorption, apparent density and porosity. Scanning electron microscopy (SEM) and x-ray micro computed tomography (µ-CT) were used to assess the changes in the microstructure when the tailings were incorporated into the geopolymers. Results show that the employment of iron ore tailings is not detrimental to the mechanical strength of geopolymers; however, geopolymers containing those alternative aggregates may present higher water absorption and porosity, and durability studies are required.

Abstract Aim: To analyze success and failure of offensive sequences and the adopted offensive method in under-15 (U-15) and under-17 (U-17) soccer players. Methods: The sample was composed of 218 offensive sequences performed by U-15 and U-17 players selected from 28 matches, being 18 matches of an Italian team and 10 matches of a Brazilian team. All offensive sequences which ended in finalization were selected for the analysis. Using observational methodology, an adapted ad hoc observational instrument was built with the variables “number of players involved”, “ball touches”, “passing”, “duration”, and “corridor changes”. Next, offensive actions were classified into three offensive game methods: counter-attack, quick attack, and positional attack. Results: Results revealed that teams which use positional attack expend more time constructing an offensive play, involve extra players, and change the ball corridor more often during offensive actions when compared to counter-attack and quick attack (p<0.01). Moreover, offensive efficacy did not present an association with the offensive method employed (X2=0.47; p=0.78). Sequences that finished in success presented significantly higher values of the number of touches (p=0.02), passes (p=0.003), and duration (p=0.01) in comparison to failure. Conclusion: The findings suggest that all offensive methods adopted can be used to reach success during a game of U-15 and U-17 soccer players.

RESUMO O objetivo do estudo foi comparar o desempenho tático, os indicadores antropométricos e as capacidades físicas entre diferentes grupos maturacionais em jovens futebolistas. Fizeram parte do estudo 48 jogadores de futebol (14,80±1,52 anos). Foram realizadas medidas antropométricas de massa corporal, estatura e altura tronco-cefálica. O Pico de Velocidade de Crescimento (PVC) foi utilizado como indicador relativo de maturidade somática. Foram realizados os testes de sentar-e-alcançar, Yo-Yo Intermittent Recovery Test level 1, preensão manual, abdominal modificado e saltos verticais (Counter Movement Jump e Squat Jump). O desempenho tático foi obtido através do Sistema de Avaliação Tática no Futebol (FUT-SAT). Para análise estatística, utilizou-se a Análise de Cluster, Anova One-Way e o coeficiente de correlação de Pearson. Os resultados indicaram que os jogadores adiantados no processo maturacional apresentaram valores superiores no desempenho das capacidades físicas como resistência aeróbia e força muscular de membros inferiores (P<0,01). Os princípios táticos "cobertura ofensiva", "unidade ofensiva" e "concentração" foram mais executados por jogadores Pós-PVC comparativamente ao grupo Pré-PVC (P<0,05). Foram observadas correlações significativas entre o PVC e os princípios "cobertura ofensiva" (r=0,32), "unidade ofensiva" (r=0,39) e "concentração" (r=0,38). Tais resultados sugerem que o avanço na classificação maturacional exerce baixa influencia sobre a gestão do espaço de jogo de jovens futebolistas.

ABSTRACT The aim of the study was to compare the tactical performance, anthropometric indicators, and physical capabilities between different maturational groups in young soccer players. Study participants were 48 soccer players (14.80±1.52 years). Anthropometric measurements of weight, height, and trunk-cephalic height were carried out. Peak height velocity (PHV) was used as a relative indicator of somatic maturity. For evaluation of physical capabilities, the sit-and-reach test, Yo-Yo Intermittent Recovery Test Level 1, handgrip test, modified abdominal test, and vertical jumps (Counter Movement Jump and Squat Jump) were performed. Tactical performance was achieved through the System of Tactical Assessment in Soccer (FUT-SAT). For statistical analysis, non-hierarchical k-means Cluster Analysis, One-Way ANOVA, and the Pearson correlation coefficient were used. The results indicated that early players in the maturational process presented higher values in the performance of physical capabilities such as aerobic endurance and lower limb muscle strength (P<0.01). Tactical principles "offensive coverage", "offensive unity", and "concentration" were executed more frequently by the Post-PHV group than the Pre-PHV (P<0.05). Significant correlations were observed between PHV and the principles "offensive coverage" (r=0.32), "offensive unity" (r=0.39), and "concentration" (r=0.38). These results suggest that advancement in maturational classification has little influence on the management of gaming space.

Geopolymers may be described as solid and stable synthesized aluminosilicate materials, whose properties are generally believed to provide a superior durability behavior. The work in hand presents the results of an experimental investigation on the thermomechanical behavior of geopolymer matrices composed by metakaolin (MK), silica fume (SF) and blast furnace slag (BFS). The alkaline activator solution consisted of sodium silicate and sodium hydroxide. The use of different aggregates was also investigated, by replacing natural sand with chamotte. Samples were submitted to different temperatures at predetermined intervals to a maximum of 1000ºC. Compression tests were performed, before and after the exposure to elevated temperatures. X-ray diffraction, thermal analysis (TGA and DTA) and scanning electron microscopy (SEM) were used to investigate the microstructural characteristics of the studied materials. The results showed that the presence of BFS in the geopolymer mixture significantly increases its mechanical response. However, the incorporation of SF presents inferior behavior in regular conditions and when exposed to elevated temperatures. The replacement of sand with chamotte results in higher compatibility above 500ºC, when a better tolerance to extreme environmental temperature conditions was observed.

A Análise de Ciclo de Vida (ACV) é um método que inclui a compilação e avaliação das entradas, saídas e dos impactos de um produto ao longo do seu ciclo de vida. Os resultados desta análise são utilizados para escolher alternativas favoráveis para uma aplicação específica. Este artigo utilizou as ferramentas de ACV, apoiada pelo software Umberto, para comparar o processo de obtenção de concretos de cimento Portland com o de concretos geopoliméricos, obtidos da ativação alcalina de aluminossilicatos. O impacto ambiental foi avaliado considerando 1 m³ de cada concreto, sendo (i) as emissões de CO2 (kg CO2/ m³) e (ii) a demanda energética (MJ/m³) as variáveis para determinar o potencial sustentável de ambos materiais. O objetivo principal foi avaliar se os concretos geopoliméricos são mais sustentáveis do que os concretos tradicionais. Os resultados obtidos mostraram que o consumo energético é reduzido em 45,8% na produção do concreto geopolimérico, quando comparado à produção do concreto de cimento Portland de desempenho mecânico equivalente. Com relação às emissões de CO2, o concreto geopolimérico reduz as emissões em 72,4%, em comparação ao concreto tradicional de cimento Portland CPII. Assim, o primeiro se mostra uma alternativa a ser considerada, na produção de materiais de construção de menor impacto ambiental.

The Life Cycle Assessment (LCA) method comprises the compilation and evaluation of inputs, outputs and environmental impacts of a product during its life cycle. The results of this analysis are used to select alternative products or processes for a particular application. This paper compared the process of making Portland cement concrete and Geopolymer concrete, the latter obtained from the alkaline activation of aluminosilicates. The CO2 emissions (kg CO2 / m³) and energy demand (MJ / m³) for the production of 1 m³ of both concretes were used to determine the sustainable potential of these materials. The main objective was to assess whether geopolymer concrete is more sustainable than traditional Portland cement concrete. The results showed that geopolymer concrete reduces energy consumption by 45.8%, compared with Portland cement-based concrete, and has a similar mechanical performance. In addition, the use of geopolymer concrete reduces CO2 emissions by 72.4%, when compared with traditional CP-II Portland cement concrete. Hence, Geopolymer is an alternative material with lower environmental impact that should be considered in the production of sustainable building materials.

The work described in this paper is related to the effect of adding carbon nanotubes (CNT) on the mechanical properties of polymer-cement composites. A full factorial design has been performed on 160 samples to identify the contribution provided by the following factors: polymeric phase addition, CNT weight addition and water/cement ratio. The response parameters of the full factorial design were the bulk density, apparent porosity, compressive strength and elastic modulus of the polymer-cement-based nanocomposites. All the factors considered in this analysis affected significantly the bulk density and apparent porosity of the composites. The compressive strength and elastic modulus were affected primarily by the cross-interactions between polymeric phase and CNT additions, and the water/cement ratio with polymeric phase factors.

Steatite is a mineral which has been employed in the carving of elements in facades of Brazilian historical buildings and churches since the 17th century. Over the years, many of those historical buildings suffered the consequences of weathering with a current need for restoration. Recently a special cement-based mortar containing additions of fine powder waste from mineral extraction of steatite has been developed in Brazil, as a composite material for restoration of steatite elements. However, the incorporation of steatite waste reduces the flexural strength of the mortar and compromises the restoration of elements where gravity imposes tensile stresses. The addition of carbon fibres may overcome this issue and increase the flexural strength of the cement-steatite composite mortar. This work investigates the effect of carbon fibre addition on the bulk density and flexural strength of compacted precast cement-steatite composites. The results show that the addition of carbon fibres (i) effectively increases the mechanical strength, allowing for a higher amount of steatite powder waste in the mixes; (ii) reduces the weight of the structural elements. This new composite material would help to develop restoration techniques of historical buildings and serve as a disposal route of steatite powder waste in Brazil.