842 research outputs found
Prevalência de problemas de comportamento em uma amostra de estudantes do ensino fundamental de escolas públicas
Este estudo investigou a prevalência de problemas de comportamento em uma amostra de estudantes do ensino fundamental de escolas públicas de Cachoeirinha-RS. Participaram 79 crianças, sendo 53,2% meninos (n=42) e 46,8% meninas (n=37), com idades entre 8 a 11 anos (M = 9,75, DP = 1,35). Todas as crianças dos estudo foram avaliadas pelo Questionário de Comportamentos Agressivos e Reativos entre Pares (Q- CARP). 34 crianças que tiveram o CBCL preenchido pelos pais ou responsáveis. Os resultados do teste Q-CARP apontaram baixa frequência de comportamentos agressivos. Em relação à reação diante da agressão de pares, as crianças relataram alta frequência de comportamentos de busca de apoio do professor e baixa ocorrência de comportamentos agressivos reativos e de reações internalizadas. Os resultados do CBCL indicaram a prevalência dos comportamentos agressivos, ansiedade/depressão e problemas sociais. Conclui-se que é importante conhecer as caracterÃsticas sociodemográficas e de comportamento em crianças escolares e do contexto familiar pois estes podem atuar como fatores de proteção ou de risco para o desenvolvimento infantil
Capes at 25 Years!
Laura Poll's presentation from the MARAC Fall 2014 conference, "CAPES at 25 Years!", S10 - October 18, 2014, Baltimore, M
La conca alta del Francolà i els seus molins: reconstrucció hidrà ulica de crescudes extraordinà ries per l'anà lisi de freqüències dels cabals de crescuda
Mà ster Oficial en Recursos Minerals i Riscos Geològics, Universitat de Barcelona - Universitat Autònoma de Barcelona, Facultat de Geologia. Curs: 2020-2021. Tutora: Glòria Furdada Bellavista. Cotutors: Jordi Tuset Mestre i J. Carles Balasch Solanes[cat] Al llarg del darrer segle i mig la conca alta del riu Francolà ha estat afectada per quatre grans riuades
de tipus flash flood. Aquestes riuades històriques han causat un gran nombre de danys materials i
pèrdues de vides humanes. Aquest estudi pretén aportar coneixement sobre la freqüència i cabals
amb què es produeixen aquestes riuades, útil per fer els mapes de perillositat i risc necessaris per a la
planificació i gestió del territori.
S’ha fet una recerca a la zona dels molins i limnimaques que s’hi troben a través de fonts
bibliogrà fiques i dades de camp. S’ha seleccionat i estudiat un tram on se situa el Molà del Celdoni i se
n’ha reconstruït els cabals pic de les dues riuades més recents (1994 i 2019) utilitzant el software lliure
Iber com a model hidrà ulic. Finalment s’ha recalculat els perÃodes de retorn tenint en compte les dades
dels cabals sistemà tiques (aforaments) i no sistemà tiques (reconstruïts de les limnimarques
històriques) per a perÃodes de retorn de baixa freqüència.
Els resultats han estat per una banda una base de dades georeferenciada dels molins i les
limnimarques que se situen a la capçalera de la conca del FrancolÃ. Per l’altra banda, s’han estimat
cabals pic de 380 m3/s per la riuada del 1994 amb un perÃode de retorn inferior a 50 anys, d’acord
amb l’anà lisi de freqüència. En canvi, per la riuada del 2019 s’han estimat cabals de 780 m3/s i
corresponents a un perÃode de retorn d’entre 50 i 100 anys. Aquest estudi mostra la importà ncia de
tenir en compte les dades no sistemà tiques, ja que i) redueixen els perÃodes de retorn i, ii) fan
multiplicar per 8 els cabals obtinguts només amb dades sistemà tiques per els mateixos perÃodes de
retorn.[eng] Over the last century and a half, the upper Francolà river basin has been affected by four flash floods.
These historical floods caused a large material damage and loss of human life. This study aims to
provide knowledge about the flood occurrence, their frequencies and their peak flows. These are key
data for hazard and risk mapping, needed for land use planning and management.
We carried out a research of the mills and flood water marks within the study area by means of a
bibliographic review and field data. A reach that includes the Molà del Celdoni was selected and
studied. We have been able to reconstruct the peak flows of the two most recent floods (1994 and
2019) using the open source Iber software. Finally, the return periods have been recalculated taking
into account the data of systematic (gauging data) and non-systematic flows (reconstructed from the
historical marks) for long return periods.
The results have been, first, a georeferenced database of the mills and flood water marks located at
the head of the Francolà basin. Second, peak flows of 380 m3/s were estimated for the 1994 flood,
with a return period <50 years according to the frequency analysis. Contrastingly, for the 2019 flood
we estimated flows of 780 m3/s with a corresponding return period between 50-100 years. This study
highlights the importance of considering non-systematic data, because i) they reduce return periods
and, ii) they increase 8 times the peak flows obtained only with systematic data for the same return
periods
Dealing with Unprecedented Disaster and Damage: Real-time Responses to Hurricane Sandy
Paper and presentation from the MARAC conference in Philadelphia, PA on November 7-9, 2013. S24 - Dealing with Unprecedented Disaster and Damage: Real-time Responses to Hurricane Sand
Donated Records Partnership Project-The Collection Match
Presentation titled, "Donated Records Partnership Project -- The Collection Match" given by Dawn Sherman-Fells, Meghan Ryan Guthorn, William Casari, Beth Harris, and Laura Poll at the MARAC Spring 2014 conference, S4 - April 25, 2014, Rochester, N
Inventário de Depressão Infantil (CDI): uma revisão de artigos cientÃficos brasileiros
Despite the consensus among health professionals regarding the recognition of depressive symptoms in childhood and adolescence, their diagnosis still presents difficulties. The literature points to the Children’s Depression Inventory (CDI) as a widely used instrument to measure this construct. This article reviews the scientific articles about the CDI published in Brazilian journals from 2000 to 2010. It was found that most of the research studies were conducted after 2005, in school settings, with both boys and girls, and aimed to evaluate the association of depressive symptoms and psychosocial variables. The studies reported good reliability indices for the CDI, however, there were differences regarding its factorial structure. New studies are necessary to prove the validity of the CDI as a useful measure to evaluate depressive symptoms in children and adolescents.Key words: review, childhood depression, CDI, evaluation.Apesar do consenso entre profissionais da saúde quanto ao reconhecimento dos sintomas depressivos na infância e na adolescência, seu diagnóstico ainda apresenta dificuldades. A literatura aponta o Inventário de Depressão Infantil (CDI) como um instrumento bastante utilizado para medir este construto. O presente estudo revisa os artigos cientÃficos sobre o CDI, publicados em periódicos brasileiros no perÃodo de 2000 a 2010. Verificou-se que a maior parte das pesquisas foi conduzida a partir de 2005, no contexto escolar, com meninos e meninas e com o objetivo de verificar a associação de sintomas depressivos e variáveis psicossociais. As pesquisas reportaram bons Ãndices de confiabilidade para o CDI, contudo, houve diferenças quanto à sua estrutura fatorial. Evidencia-se, assim, a necessidade de novos estudos que apontem novas evidências de validade do CDI como um instrumento útil para avaliar sintomas depressivos em crianças e adolescentes.Palavras-chave: revisão, depressão infantil, CDI, avaliação
Numerical simulation and experimental validation of the cladding material distribution of hybrid semi-finished products produced by deposition welding and cross-wedge rolling
The service life of rolling contacts is dependent on many factors. The choice of materials in particular has a major influence on when, for example, a ball bearing may fail. Within an exemplary process chain for the production of hybrid high-performance components through tailored forming, hybrid solid components made of at least two different steel alloys are investigated. The aim is to create parts that have improved properties compared to monolithic parts of the same geometry. In order to achieve this, several materials are joined prior to a forming operation. In this work, hybrid shafts created by either plasma (PTA) or laser metal deposition (LMD-W) welding are formed via cross-wedge rolling (CWR) to investigate the resulting thickness of the material deposited in the area of the bearing seat. Additionally, finite element analysis (FEA) simulations of the CWR process are compared with experimental CWR results to validate the coating thickness estimation done via simulation. This allows for more accurate predictions of the cladding material geometry after CWR, and the desired welding seam geometry can be selected by calculating the cladding thickness via CWR simulation. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Influence of degree of deformation on welding pore reduction in high-carbon steels
Locally adapted properties within a machine component offer opportunities to increase the performance of a component by using high strenght materials where they are needed. The economic production of such hybrid components on the other hand represents a major challenge. The new tailored forming process chain, which is developed within the collaborative research center (CRC 1153) represents a possible solution to produce hybrid components. This is made possible by the use of pre-joined hybrid semi-finished products made from two different steel alloys, which are subsequently formed. The semi-finished products can be manufactured for example by means of deposition welding. Due to a thermal mechanical treatment, an overall higher component strength of the joining zone can be achieved. The deposition welding processes can be used to generate a cladding on a base material. During the welding, one of the most difficult tasks is to reduce the amount and size of pores in the joining zone. These pores can reduce the strength in the joining zone of the welded parts. However, additional pores can occur in the intermediate zone between the substrate and the cladding. In the presented study, the influence of the forming process on the closing of pores in the cladding and in the intermediate zone was investigated. Therefore, cylindrical specimen were extracted in longitudinal direction of the welding track by wire-cut eroding. These welding tracks are manufactured by plasma-transferred arc welding of AISI 52100 on a base plate made of AISI 1015. Further, specimens were prepared transversely, so that the base material, the intermediate layer, and the welded material are axially arranged in the specimen. The prepared specimen were checked for pores by means of scanning acoustic microscopy. Subsequently, an uniaxial compression test was carried out with various degrees of deformation and the two specimen designs were examined again for pores. A microstructure analysis was carried out after each step. The investigations show that there is a need for a minimum degree of deformation to reduce pores in the welded material. However, this required plastic strain cannot be achieved in the welded material of the hybrid specimen, which is a result of the homogeneous temperature distribution in the specimen. The homogeneous temperature distribution leads to different flow properties in the specimen, which means that the main plastic deformation is taking place in the base material. © 2021, The Author(s)
Investigations on tailored forming of aisi 52100 as rolling bearing raceway
Hybrid cylindrical roller thrust bearing washers of type 81212 were manufactured by tailored forming. An AISI 1022M base material, featuring a sufficient strength for structural loads, was cladded with the bearing steel AISI 52100 by plasma transferred arc welding (PTA). Though AISI 52100 is generally regarded as non-weldable, it could be applied as a cladding material by adjusting PTA parameters. The cladded parts were investigated after each individual process step and subsequently tested under rolling contact load. Welding defects that could not be completely eliminated by the subsequent hot forming were characterized by means of scanning acoustic microscopy and micrographs. Below the surface, pores with a typical size of ten µm were found to a depth of about 0.45 mm. In the material transition zone and between individual weld seams, larger voids were observed. Grinding of the surface after heat treatment caused compressive residual stresses near the surface with a relatively small depth. Fatigue tests were carried out on an FE8 test rig. Eighty-two percent of the calculated rating life for conventional bearings was achieved. A high failure slope of the Weibull regression was determined. A relationship between the weld defects and the fatigue behavior is likely. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Seroprevalence of cytomegalovirus and its coinfection with epstein-barr virus in adult residents from manaus: A population-based study
Introduction: This study assessed the seroprevalence of cytomegalovirus, associated factors, and Epstein-Barr virus coinfection among adult residents of Manaus. Methods: Using a cross-sectional study design, we collected blood samples from 136 individuals in a household survey in 2016. Prevalence ratios were calculated using Poisson regression. Results: Cytomegalovirus and Epstein-Barr virus seroprevalences were 67.6% (95% CI: 9.7-75.6%) and 97.8% (95% CI: 95.3-100.0%), respectively. Coinfection was observed in 66.2% (95% CI: 58.1-74.2%) of participants. Bivariate analysis showed no statistical association. Conclusions: Seroprevalences were high among participants and approximately 7 out of 10 individuals had cytomegalovirus and Epstein-Barr virus coinfection. © 2020, Sociedade Brasileira de Medicina Tropical. All rights reserved
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