Vibration behavior of thin-walled steel members subjected to uniform bending.

This article reports the results of an investigation on the effects of internal moments on the vibration behavior of thin-walled steel members. The analyses are based on the Generalized Beam Theory (GBT), a thin-walled bar theory accounting for crosssection in-plane deformations ? its main distinctive feature is the representation of the member deformed configuration by means of a linear combination of cross-section deformation modes, multiplied by their longitudinal amplitude functions. The study concerns a simply supported T-section (with unequal flanges) members exhibiting a wide range of lengths and subjected to uniform internal moment diagrams ? their magnitudes are specified as percentages of the corresponding critical buckling values. After providing a brief overview of the main concepts and procedures involved in performing a GBT-based structural analysis, the vibration behavior of load-free and loaded T-section members is addressed ? the influence of the applied loadings is assessed in terms of (i) the fundamental frequency difference and (ii) the change in the corresponding vibration mode shape. For validation purposes, some GBT results are compared with values yielded by shell finite element analysis performed in the code ABAQUS (Simulia, 2008)

DYNAMICS OF VEGETATION IN AN ATLANTIC FOREST FRAGMENT IN NORTHEASTERN BRAZIL

Para testar a hip\uf3tese que a fisionomia, estrutura e din\ue2mica de esp\ue9cies lenhosas s\ue3o influenciadas pelo gradiente espacial borda-interior, foram coletados dados desses par\ue2metros em 2004, 2007 e 2010 em um fragmento de Floresta Atl\ue2ntica. Foram amostradas para o Dossel (DS), plantas com circunfer\ueancia do caule a altura do peito (CAP) > 15 cm e do sub-bosque (SB) com circunfer\ueancia ao n\uedvel do solo entre > 3 cm e CAP < 15 cm em um gradiente borda-interior formado h\ue1 35 anos. Em 2004, foram avaliadas tr\ueas posi\ue7\uf5es no fragmento: borda, intermedi\ue1ria e interior (> 150 m do limite florestal), sendo analisados 1000 m\ub2 por local, divididos em parcelas de 10 m\ub2, para medir os indiv\uedduos de maior classe. Em cada parcela foi instalada uma subparcela de 5 m\ub2 para amostragem do sub-bosque. Foram recolhidos ramos de tr\ueas indiv\uedduos adultos das esp\ue9cies, para obten\ue7\ue3o da densidade da madeira. O n\ufamero de indiv\uedduos (NI), \ue1rea basal (AB), taxa de mortalidade (TM), taxa de recrutamento (TR), incremento peri\uf3dico anual em di\ue2metro (IPA), taxa de perda (P) e ganho (G) de \ue1rea basal e as taxas de rotatividade em n\ufamero de indiv\uedduos (TN) e em \ue1rea basal (TA) da classe do componente arb\uf3reo nos tr\ueas locais evidenciaram n\ue3o haver efeito de borda significativo. Na borda, o sub-bosque teve menores valores de NI e AB e maiores TM, que no interior do fragmento. Diferen\ue7as entre os estratos acontecem, independentemente do selamento da borda, j\ue1 que plantas jovens na maior classe amostral apresentam indiv\uedduos no SB, que s\ue3o mais sens\uedveis que as \ue1rvores adultas \ue0s mudan\ue7as causadas pela cria\ue7\ue3o da borda. Taxas de perda e ganho de AB e de rotatividade em NI e AB, no SB, apresentaram valores maiores que no DS, o que aponta para um estrato com maiores mudan\ue7as. No DS n\ue3o ocorreram diferen\ue7as de riqueza de esp\ue9cies entre os ambientes, distinto do observado no SB. A composi\ue7\ue3o flor\uedstica no DS nos ambientes mais pr\uf3ximos ao limite florestal foi bastante distinta que a do interior, indicando que ainda n\ue3o houve recupera\ue7\ue3o da composi\ue7\ue3o flor\uedstica. Todos os ambientes do SB tiveram baixa similaridade. As bordas do DS e SB apresentaram maior concentra\ue7\ue3o de indiv\uedduos em intervalos de classe de menores valores de densidade de madeira. O DS j\ue1 recuperou a biomassa, embora os ambientes de borda e intermedi\ue1rio n\ue3o tenham recuperado a composi\ue7\ue3o de esp\ue9cies tardias. O SB ainda sofre efeito de borda. Possivelmente, a maior concentra\ue7\ue3o de indiv\uedduos em classe de menor densidade da madeira sendo resultado na borda.To test the hypothesis that the physiognomy, structure and dynamics of woody species are influenced by the spatial gradient edge-interior, data were collected from these parameters in 2004, 2007 and 2010 in an Atlantic forest fragment. Species were sampled for the Canopy (DS), with circumference > 15 cm to 1.3 m soil and understory (SB) in circumference between ground level> 3 cm and CAP <15 cm on edge-gradient formed within 35 years. In 2004, we assessed three positions in the fragment: edge, intermediate and inner (> 150 m from the forest boundary), and analyzed 1,000 m\ub2 per site, divided into plots of 10 m\ub2, to measure individuals of higher class. In each plot a sub-plot of 5 m\ub2 for sampling understory was installed. Branches were collected from three adult individuals from the species to obtain the density of the wood. The number of individuals (NI), basal area (BA), mortality (TM), recruitment rate (TR), periodic annual diameter increment (IPA), loss rate (P) and gain rate (G) Area and basal turnover rates in number of individuals (TN) and basal area (TA) class tree component in the three locations showed no significant edge effect. At the edge, the understory had lower values of NI and AB and higher TM than in the forest interior. Differences between the strata occur regardless of edge sealing, since young plants present in most individuals in the sample class SB, which are more sensitive than adult trees to changes caused by the creation of the edge. Rates of loss and gain of AB and AB turnover in NI and in SB presented higher values than on the DS, which points to a stratum with larger changes. In DS there were no differences in species richness among environments differs from that observed in SB. The floristic composition of the DS in environments closer to the forest limit was quite distinct from that of the interior, indicating that there has been no recovery of floristic composition. All environments SB had low similarity. The edges of the DS and SB had a higher concentration of individuals in class intervals smaller density values timber. The DS has already recovered biomass, although the edge and intermediate environments have not recovered species composition late. The SB still suffers the edge effect. Possibly, the highest concentration of individuals is in class with lower density wood result on edge

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Sanear, prever e embelezar : o engenheiro Saturnino de Brito, o urbanismo sanitarista e o novo projeto urbano do PRR para o Rio Grande do Sul (1908-1929)

Made available in DSpace on 2015-04-14T13:48:05Z (GMT). No. of bitstreams: 1 450691.pdf: 9351958 bytes, checksum: 5770437d1069fca3d1ab0e232282c93f (MD5) Previous issue date: 2013-08-30The objective of this study is to describe the set of works made by engineer Francisco Rodrigues Saturnino de Brito and his ideas of urban sanitation, served as guidance to the formation of a new urban project in Rio Grande do Sul. Requested in the context of establishment of the Republic these works emerge as a political tool of the Republican Party-Rio Grande (PRR) and its new urban design, thus guiding the progress that was required with the installation of the new regime. These works should be thought also as an instrument of intervention in urban space, based on technical studies prepared by an expert quite attuned to the knowledge of his timeO objetivo deste trabalho ? demonstrar como o conjunto de obras realizadas pelo engenheiro Francisco Saturnino Rodrigues de Brito e suas ideias de urbanismo sanitarista, serviram de orienta??o ? forma??o de um novo projeto urbano no Rio Grande do Sul. Solicitadas no contexto de implanta??o da Rep?blica, estas obras surgem como um instrumento pol?tico do Partido Republicano Rio-Grandense (PRR) e de seu novo projeto urbano, orientando assim, o progresso que se impunha com a instala??o do novo regime. Estas obras devem ser pensadas tamb?m como um instrumento de interven??o no espa?o urbano, calcado em estudos t?cnicos, elaborado por um especialista bastante sintonizado com os conhecimentos de sua ?poc

A moderniza??o do espa?o urbano em Pelotas e a Companhia Telef?nica Melhoramento e Resist?ncia : 1947-1957

Made available in DSpace on 2015-04-14T13:48:10Z (GMT). No. of bitstreams: 1 389018.pdf: 9459500 bytes, checksum: 5e9d48720dc80d3a3a0fcdca6ed46b32 (MD5) Previous issue date: 2007-03-26A presente disserta??o pretende abordar e problematizar a moderniza??o do espa?o urbano na cidade de Pelotas, no per?odo compreendido entre 1947 e 1957, tendo como fio condutor a Companhia Telef?nica Melhoramento e Resist?ncia (CTMR). Relacionando categorias como cidade, modernidade e mem?ria, esta pesquisa tentar? tra?ar um amplo e provis?rio painel do processo de urbaniza??o da cidade. Demonstrando a forma e os mecanismos pelos quais essas mudan?as se processara

Efeito da periodiza??o sobre capacidades f?sicas de basquetebolistas de um col?gio militar.

Basketball is a sport modality that imposes important physiological loads on players during competition. The aim of the study was to verify the effect of training with wave periodization on the physical capacities of athletes. Explosive strength of lower limbs; aerobic resistance; maximum strength of upper limb; and resting heart rate (HRrest) at PRE and POST moments of 16 athletes submitted to a 4-month training period were evaluated. The internal training load was monitored by the method proposed by Carl Foster in each training session. Statistically significant differences were observed in VO2max of 50.5? 4.9 vs. 54.0? 6.1 ml/kg/min (p <0.000), in the vertical impulse of 39.1? 5.9 cm vs. 44.7? 5.9 cm (p <0.000), 10 RM on bench press 40.4? 9.4 vs. 48.0? 8.9 kg (p <0.000) and in HRrest 66? 4 vs. 60? 5 bpm (p <0.000). The average internal training load was 751? 249 AU. It was concluded that school basketball athletes submitted to training macrocycle with 4-month wave periodization improve the strength of lower and upper limbs, also presenting positive adaptations in aerobic conditioning.O basquetebol ? uma modalidade que imp?e cargas fisiol?gicas importantes aos jogadores durante a competi??o. O objetivo do estudo foi verificar o efeito do treinamento com periodiza??o ondulat?ria sobre as capacidades f?sicas de jovens atletas. Foram avaliadas as capacidades de for?a explosiva de membros inferiores, resist?ncia aer?bia, for?a m?xima de membros superiores e avalia??o da frequ?ncia card?aca de repouso (FCrep) nos momentos PR? e P?S de 16 jovens basquetebolistas de um col?gio militar, que foram submetidos a um per?odo de 4 meses de treinamento. A carga interna de treinamento foi monitorada pelo m?todo proposto por Carl Foster, em cada sess?o de treinamento. Foram observadas diferen?as estatisticamente significantes no VO2m?x de 50,5?4,9 vs. 54,0?6,1 ml/kg/min (p<0,000), na impuls?o vertical de 39,1?5,9 cm vs. 44,7?5,9 cm (p<0,000), no 10 RM no supino reto 40,4?9,4 vs. 48,0?8,9 kg (p<0,000) e na FCrep 66?4 vs. 60?5 bpm (p<0,000). A carga interna de treinamento m?dia foi de 751?249 UA. Conclui-se que atletas escolares de basquetebol submetidos a um macrociclo de treinamento com periodiza??o ondulat?ria de 4 meses melhoram as capacidades de for?a de membros inferiores e superiores, apresentando tamb?m adapta??es positivas no condicionamento aer?bico

Modelagem do potencial esportivo de jovens basquetebolistas : uma an?lise preliminar.

The aims of this study were: 1) to evaluate the sports potential of young basketball players; 2) to identify variables that discriminate sports potential assessed by coaches; 3) to verifythe relationship between classification of the multidimensional profile of athletes and classification of the sports potential by coaches. Sixty-two young basketball players aged 15.6?1.1 years from U-15 (n = 24) and U-17 (n = 38) categories participated in the study. A test battery was applied to evaluate sports potential indicators: 1) anthropometric; 2) physicomotor; 3) psychological;4) skills;5) socio-environmental;6) maturational and 7) sports potential.Clusteranalysis was performed in three groups: high, medium and low potential. Student?s t-test was used for the comparison between athletes evaluated by the coach as excellent and the others and the Chi-Square test to verify the relationship between sports potential classifications. It was observed that in the high-potential group, athletes were chronologically older, with higher % predicted adult height (PMS), competitive and determined sports orientation, higher body size, lower skinfold summation, and greater physicomotor performance. In comparison with other athletes, high-potential basketball players presented higher stature, wider wingspan,longer limb length, greater predicted adult stature and higher Z score of the % PMS. It could be concluded that the multidimensional approach was useful for the evaluation of the sports potential of young basketball players, requiring the use of multidimensional variables, in addition to coaches? opinion regarding the potential of their athletes.Os objetivos deste estudo foram: 1) avaliar o potencial esportivo de jovens basquetebolistas;2) identificar vari?veis que discriminam o potencial esportivo avaliado pelos treinadores; 3) verificar a rela??o entre a classifica??o do perfil multidimensional dos atletas e a classifica??o do potencial esportivo feita pelos treinadores. Participaram 62 jovens basquetebolistas brasileiros do sexo masculino,com 15,6?1,1 anos de idade, das categorias sub15 (n=24) e sub17 (n=38), Foi aplicada uma bateria de testes para avalia??o dos indicadores do potencial esportivo: 1) antropom?tricos; 2) fisicomotores;3) psicol?gicos; 4) habilidades; 5) socioambientais; 6) maturacionais e 7) potencial esportivo. Foi realizada a an?lise de cluster classificando em 3 grupos: alto potencial, mediano e baixo potencial.Utilizou-se o teste t de Student na compara??o entre os atletas avaliados pelo treinador como excelente e os demais e o teste Qui-Quadrado para testar a rela??o entre as classifica??es do potencial esportivo.Observou-se que no grupo de alto potencial, os atletas eram mais velhos cronologicamente, com maior % estatura adulta prevista, orienta??o esportiva competitiva e determinada, maior tamanho corporal,menor somat?rio de dobras cut?neas e maior desempenho fisicomotor. Na compara??o com os demais atletas, os basquetebolistas de alto potencial apresentaram maior estatura, maior envergadura, maior comprimento de membros inferiores, maior estatura adulta prevista e maior escore Z do %EAP.Conclui-se que a abordagem multidimensional se mostrou ?til para a avalia??o do potencial esportivode jovens basquetebolistas, sendo necess?ria a utiliza??o de vari?veis multidimensionais, conjugada com a opini?o dos treinadores em rela??o ao potencial de seus atletas

Aplica??o do controle repetitivo a inversor PWM monof?sico com filtro LC de sa?da utilizado em fonte program?vel C.A.

Esse trabalho apresenta o desenvolvimento de uma estrat?gia de controle, baseada no controlador repetitivo, para regula??o de um inversor PWM com filtro LC de sa?da, para aplica??o em fontes program?veis de pot?ncia c.a. Resultados experimentais, obtidos em um modelo de escala reduzida, s?o utilizados para validar a estrat?gia de controle proposta. As principais contribui??es do trabalho s?o: (i) compara??o da uso do controlador repetitivo e do PI, em aplica??es em fontes program?veis c.a; (ii) aplica??o de t?cnicas de sintonia de controladores cl?ssicos em sistema com controlador repetitivo; (iii) apresenta??o dos resultados da t?cnica de controle repetitivo associada a controle PI com compensa??o de realimenta??es internas da planta, aplicada ao controle de uma fonte c.a. program?vel.In this work, a control strategy based on a repetitive controller for PWM voltage regulation in a frequency converter is developed, with application in a programmable AC power source. Experimental results are presented, validating the approach adopted, showing that the disturbance of highly distorted load currents are rejected without compromise to the quality of the output voltage. The main contributions of the paper are: (i) comparison of the performance of the repetitive controller and the PI controller in applications of programmable power sources; (ii) application of standard tuning techniques to repetitive controllers; (iii) presentation of results of the performance of the repetitive controller associated with PI controller with compensation of the internal feedbacks of the plant