Importance of considering a material micro-failure criterion in the numerical modelling of the shot peening process applied to parabolic leaf springs

Shot peening is a cold-working mechanical process in which a shot stream is propelled against a component surface. Its purpose is to introduce compressive residual stresses on component surfaces for increasing the fatigue resistance. This process is widely applied in springs due to the cyclical loads requirements. This paper presents a numerical modelling of shot peening process using the finite element method. The results are compared with experimental measurements of the residual stresses, obtained by the X-rays diffraction technique, in leaf springs submitted to this process. Furthermore, the results are compared with empirical and numerical correlations developed by other authors.

A ductile damage criterion at various stress triaxialities

The paper discusses the effect of stress triaxiality on the onset and evolution of damage in ductile metals. A series of tests including shear tests and experiments oil smooth and pre-notched tension specimens wits carried Out for it wide range of stress triaxialities. The underlying continuum damage model is based oil kinematic definition of damage tensors. The modular structure of the approach is accomplished by the decomposition of strain rates into elastic, plastic and damage parts. Free energy functions with respect to fictitious undamaged configurations as well as damaged ones are introduced separately leading to elastic material laws which are affected by increasing damage. In addition, a macroscopic yield condition and a flow rule are used to adequately describe the plastic behavior. Numerical simulations of the experiments are performed and good correlation of tests and numerical results is achieved. Based oil experimental and numerical data the damage criterion formulated in stress space is quantified. Different branches of this function are taken into account corresponding to different damage modes depending oil stress triaxiality and Lode parameter. In addition, identification of material parameters is discussed ill detail. (C) 2007 Elsevier Ltd. All rights reserved.

Using a New Criterion to Identify Sites for Mean Soil Water Storage Evaluation

Establishing a few sites in which measurements of soil water storage (SWS) are time stable significantly reduces the efforts involved in determining average values of SWS. This study aimed to apply a new criterion the mean absolute bias error (MABE)-to identify temporally stable sites for mean SWS evaluation. The performance of MABE was compared with that of the commonly used criterion, the standard deviation of relative difference (SDRD). From October 2004 to October 2008, SWS of four soil layers (0-1.0, 1.0-2.0,2.0-3.0, and 3.0-4.0 m) was measured, using a neutron probe, at 28 sites on a hillslope of the Loess Plateau, China. A total of 37 SWS data sets taken over time were divided into two subsets, the first consisting of 22 dates collected during the calibration period from October 2004 to September 2006, and the second with 15 dates collected during the validation period from October 2006 to October 2008. The results showed that if a critical value of 5% for MABE was defined, more than half the sites were temporally stable for both periods, and the number of temporally stable sires generally increased with soil depth. Compared with SDRD, MABE was more suitable for the identification of time-stable sites for mean SS prediction. Since the absolute prediction error of drier sites is more sensitive to changes in relative difference in terms of mean SWS prediction, the sites of wet sectors should be preferable for mean SWS prediction for the same changes in relative difference.

Implications of Extending the ADHD Age-of-Onset Criterion to Age 12: Results from a Prospectively Studied Birth Cohort

Objective: To evaluate whether including children with onset of symptoms between ages 7 and 12 years in the ADHD diagnostic category would: (a) increase the prevalence of the disorder at age 12, and (b) change the clinical and cognitive features, impairment profile, and risk factors for ADHD compared with findings in the literature based on the DSM-IV definition of the disorder. Method: A birth cohort of 2,232 British children was prospectively evaluated at ages 7 and 12 years for ADHD using information from mothers and teachers. The prevalence of diagnosed ADHD at age 12 was evaluated with and without the inclusion of individuals who met DSM-IV age-of-onset criterion through mothers` or teachers` reports of symptoms at age 7. Children with onset of ADHD symptoms before versus after age 7 were compared on their clinical and cognitive features, impairment profile, and risk factors for ADHD. Results: Extending the age-of-onset criterion to age 12 resulted in a negligible increase in ADHD prevalence by age 12 years of 0.1%. Children who first manifested ADHD symptoms between ages 7 and 12 did not present correlates or risk factors that were significantly different from children who manifested symptoms before age 7. Conclusions: Results from this prospective birth cohort might suggest that adults who are able to report symptom onset by age 12 also had symptoms by age 7, even if they are not able to report them. The data suggest that the prevalence estimate, correlates and risk factors of ADHD will not be affected if the new diagnostic scheme extends the age-of-onset criterion to age 12. J. Am. Acad. Child Adolesc. Psychiatry, 2010;49(3):210-216.

On translational superfluidity and the Landau criterion for Bose gases in the Gross-Pitaevski limit

The two-fluid and Landau criteria for superfluidity are compared for trapped Bose gases. While the two-fluid criterion predicts translational superfluidity, it is suggested, on the basis of the homogeneous Gross-Pitaevski limit, that a necessary part of Landau`s criterion, adequate for non-translationally invariant systems, does not hold for trapped Bose gases in the GP limit. As a consequence, if the compressibility is detected to be very large (infinite by experimental standards), the two-fluid criterion is seen to be the relevant one in case the system is a translational superfluid, while the Landau criterion is the relevant one if translational superfluidity is absent.

Entanglement degree measure and a criterion for sudden death as a phase transition in bipartite systems

We propose a method to compute the entanglement degree E of bipartite systems having dimension 2 x 2 and demonstrate that the partial transposition of density matrix, the Peres criterion, arise as a consequence Of Our method. Differently from other existing measures of entanglement, the one presented here makes possible the derivation of a criterion to verify if an arbitrary bipartite entanglement will suffers sudden death (SD) based only on the initial-state parameters. Our method also makes possible to characterize the SD as a dynamical quantum phase transition, with order parameter epsilon. having a universal critical exponent -1/2. (C) 2009 Elsevier Inc. All rights reserved.

A criterion for unitary similarity of upper triangular matrices in general position

Each square complex matrix is unitarily similar to an upper triangular matrix with diagonal entries in any prescribed order. Let A = [a(ij)] and B = [b(ij)] be upper triangular n x n matrices that are not similar to direct sums of square matrices of smaller sizes, or are in general position and have the same main diagonal. We prove that A and B are unitarily similar if and only if parallel to h(A(k))parallel to = parallel to h(B(k))parallel to for all h is an element of C vertical bar x vertical bar and k = 1, ..., n, where A(k) := [a(ij)](i.j=1)(k) and B(k) := [b(ij)](i.j=1)(k) are the leading principal k x k submatrices of A and B, and parallel to . parallel to is the Frobenius norm. (C) 2011 Elsevier Inc. All rights reserved.

Influência da proporção entre as alturas do ramo mandibular e dentoalveolar posterior na inclinação do plano mandibular

OBJETIVO: avaliar a existência de correlação entre a proporção da altura do ramo mandibular (AR) com a altura dentoalveolar posterior total (ADAPT) e a inclinação do plano mandibular (PM). MÉTODOS: dois examinadores avaliaram 81 telerradiografias laterais de pacientes, com idades a partir de 18 anos, do arquivo do curso de especialização em Ortodontia e Ortopedia Facial da Faculdade de Odontologia da UFBA. As radiografias foram digitalizadas, os pontos marcados e as medidas obtidas através do programa Radiocef 1.0. Mediu-se a inclinação do plano mandibular para caracterizar o padrão vertical da face e dividir as radiografias em três grupos: grupo de face normal (GN), de 22º a 28º, de face curta (GC), menor que 22º, e de face longa (GL), maior que 28º. A inclinação do plano palatino serviu como critério de exclusão, sendo que valores abaixo de -2,5° ou acima de 3,5º foram excluídos. Desta forma, 46 telerradiografias laterais totalizaram a amostra. RESULTADOS: a AR diferiu entre GC e GL, porém não houve diferença estatisticamente significante para as alturas dentoalveolares posteriores. Houve baixa correlação entre a AR e a ADAPT nos grupos, no entanto, a correlação da proporção entre essas alturas com a inclinação do PM mostrou-se estatisticamente significante e negativa. CONCLUSÃO: este é um fator a ser levado em consideração na avaliação do PM, quando do diagnóstico e tratamento das displasias verticais dentofaciais.

Correlação entre as escalas visual analógica, de Melbourne e filamentos de Von Frey na avaliação da dor pós-operatória em cadelas submetidas à ovariossalpingohisterectomia

A avaliação da dor em animais necessita da utilização de escalas de avaliação, que dependem da interpretação realizada por observadores. O objetivo do presente estudo foi avaliar a correlação entre a escala visual analógica (EVA), escala de Melbourne e os filamentos de Von Frey, na avaliação da dor pós-operatória em 42 cadelas adultas e saudáveis, submetidas à ovariossalpingohisterectomia (OSH). A dor pós-operatória foi avaliada por dois observadores cegos aos tratamentos analgésicos, em intervalos de uma hora, utilizando a EVA, a escala de Melbourne e os filamentos de Von Frey, aplicados ao redor da incisão cirúrgica. Foram considerados como critérios para realização da analgesia resgate uma pontuação de 50mm na EVA ou de 13 pontos na escala de Melbourne. A EVA revelou-se a escala mais sensível, uma vez que 100% dos animais receberam resgate seguindo esse método. Os valores obtidos na EVA e na escala de Melbourne determinaram boa correlação, com r=0,74, o que não ocorreu com os filamentos de Von Frey (r=-0,18). Já a correlação entre a escala de Melbourne e os filamentos de Von Frey foi de -0.37. Apesar de a EVA e a escala de Melbourne apresentarem boa correlação, sugere-se que se considere uma pontuação menor na escala de Melbourne como critério para administração de analgesia resgate.

Recalled and recorded bowel habits confirm early onset and high frequency of constipation in day-care nursery children

CONTEXT: Mothers recall early-onset constipation in children attending gastroenterology clinics. OBJECTIVES: To study the bowel habit of young children in the community to determine, first, whether early-onset constipation is confirmed in this setting and, second, the agreement between recalled and recorded bowel habit. METHODS:Defecation data of 57 children aged 6.0-40.7 mo were obtained by maternal recall (questionnaire on predominant stool characteristics) and by record (1,934 defecations registered prospectively at home and in the nursery). The bowel habit was classified according to stool frequency and proportion of stool characteristics (soft, hard and/or runny). Two criteria were used to classify recorded data, since the cutoff point for hard stools to identify constipation is undefined in children: predominant criterion and adult criterion, respectively with >50% and >25% of stools with altered consistency. Bowel habit categories were: adequate, constipation, functional diarrhea and "other bowel habit". Nonparametric statistics, and the Kappa index for agreement between recalled and recorded bowel habit, were used. RESULTS: Constipation occurred in 17.5%, 10.5%, 19.3% of the children by recall, the predominant and the adult criteria, respectively. Constipation was the main recalled alteration, vs 12.3% "other bowel habit". Only one child classified as having functional diarrhea (by the adult criterion). Agreement between recalled and recorded bowel habit was fair for constipation, by the predominant and the adult criteria (K = 0.28 and 0.24, respectively), but only slight (K <0.16) for other bowel habit categories. Individual data, however, pointed to a better relationship between recalled constipation and the adult rather than the predominant criterion. CONCLUSIONS: Frequent early-onset constipation was confirmed. Fair agreement between recalled and recorded constipation by the two used criteria indicates that recalled data are quite reliable to detect constipation.

Epidemiologia da leishmaniose tegumentar americana no Estado do Acre, Amazônia brasileira

Efetuou-se estudo estatístico descritivo em 8.516 casos de leishmaniose tegumentar americana no Estado do Acre, Brasil, no período de 2001 a 2006 (segundo período), comparando-se com os resultados de publicação anterior com dados no mesmo estado entre 1992 e 1997 (primeiro período). A prevalência no estado mais que dobrou entre os dois momentos (55,7/10 mil habitantes de 1992 a 1997 e 128,5/10 mil habitantes entre 2001 e 2006. O sexo masculino foi o mais acometido (68,8%, n = 5.860) no segundo período. A média das idades foi de 26,3 anos, valor discretamente menor do que o do primeiro período. Pacientes com baixa escolaridade foram os mais acometidos pela doença. As demais variáveis avaliadas foram zona de residência, ocupação, critério de diagnóstico, forma clínica, tratamento, recidiva, tempo para procurar tratamento e evolução da doença. Conclui-se que houve piora nos indicadores epidemiológicos da leishmaniose tegumentar americana avaliados no estado entre os períodos estudados.

Changes in parents' and self-reports of behavioral problems in Brazilian adolescents after behavioral treatment with urine alarm for nocturnal enuresis

PURPOSE: Compare parents' reports of youth problems (PRYP) with adolescent problems self-reports (APSR) pre/post behavioral treatment of nocturnal enuresis (NE) based on the use of a urine alarm. MATERIALS AND METHODS: Adolescents (N = 19) with mono-symptomatic (primary or secondary) nocturnal enuresis group treatment for 40 weeks. Discharge criterion was established as 8 weeks with consecutive dry nights. PRYP and APSR were scored by the Child Behavior Checklist (CBCL) and Youth Self-Report (YSR). RESULTS: Pre-treatment data: 1) Higher number of clinical cases based on parent report than on self-report for Internalizing Problems (IP) (13/19 vs. 4/19), Externalizing Problems (EP) (7/19 vs. 5/19) and Total Problem (TP) (11/19 vs. 5/19); 2) Mean PRYP scores for IP (60.8) and TP (61) were within the deviant range (T score ≥ 60); while mean PRYP scores for EP (57.4) and mean APSR scores (IP = 52.4, EP = 49.5, TP = 52.4) were within the normal range. Difference between PRYP' and APSR' scores was significant. Post treatment data: 1) Discharge for majority of the participants (16/19); 2) Reduction in the number of clinical cases on parental evaluation: 9/19 adolescents remained within clinical range for IP, 2/19 for EP, and 7/19 for TP. 3) All post-treatment mean scores were within the normal range; the difference between pre and post evaluation scores was significant for PRYP. CONCLUSIONS: The behavioral treatment based on the use of urine alarm is effective for adolescents with mono-symptomatic (primary and secondary) nocturnal enuresis. The study favors the hypothesis that enuresis is a cause, not a consequence, of other behavioral problems.

Validade e confiabilidade da versão brasileira do Índice de Capacidade para o Trabalho

OBJETIVO: Avaliar a validade e a confiabilidade da versão brasileira de índice de capacidade para o trabalho. MÉTODOS:Estudo transversal com amostra de 475 trabalhadores de empresa do setor elétrico no estado de São Paulo (dez municípios em Campinas e região), realizado em 2005. Foram avaliados os seguintes aspectos da versão brasileira do Índice de Capacidade para o Trabalho: validade de construto, por meio de análise fatorial confirmatória e da capacidade discriminante; validade de critério, correlacionado o escore do índice com medidas de saúde auto-referidas; e confiabilidade, por meio da análise da consistência interna utilizando o coeficiente alfa de Cronbach. RESULTADOS: A análise fatorial indicou três fatores do construto capacidade para o trabalho: questões relativas aos "recursos mentais" (20,6% da variância), à autopercepção da capacidade para o trabalho (18,9% da variância) e à presença de doenças e limitações decorrentes do estado de saúde (18,4% da variância). O índice discriminou os trabalhadores segundo nível de absenteísmo, identificando média estatisticamente significativa (p<0,001) entre aqueles com absenteísmo elevado (37,2 pontos) e baixo (42,3 pontos). A análise de critério mostrou correlação do índice com todas as dimensões do estado de saúde analisadas (p<0,0001). O índice apresentou boa confiabilidade com coeficiente alfa de Cronbach (0,72). CONCLUSÕES: A versão brasileira do Índice de Capacidade para o Trabalho mostrou propriedades psicométricas satisfatórias quanto à validade de construto, de critério e de confiabilidade, representando uma opção adequada para avaliação da capacidade para o trabalho em abordagens individuais e inquéritos populacionais.

Prática e duração do aleitamento materno de crianças matriculadas em escolas particulares do município de São Paulo, SP

presente estudo descreve a prática de aleitamento materno e verifica possíveis fatores de associação com a duração do aleitamento materno exclusivo e aleitamento materno em crianças de escolas particulares do município de São Paulo. Fizeram parte do estudo 566 crianças, com 2 a 6 anos completos de idade. Foi considerada como variável dependente a duração do aleitamento materno (aleitamento materno exclusivo e aleitamento materno), e como independente idade e escolaridade materna, condição de trabalho da mãe e sexo da criança. A caracterização da amostra é apresentada por meio de distribuições de freqüências. A variável aleitamento materno foi descrita em categorias, e para análise foi utilizada como variável contínua. Para a análise da relação entre duração do aleitamento materno e as variáveis independentes utilizou-se a técnica de regressão múltipla de Cox adotando-se critério p < 0,05 para decisão de significância. Não houve associação entre as variáveis estudadas e tempo de duração das duas formas de aleitamento. Cerca de 80% das crianças deixaram de ser amamentadas exclusivamente antes dos seis meses de vida, o que mostra a necessidade de continuar o desenvolvimento de ações para incentivo e apoio à amamentação

Prediction of good glass formers in the Al-Ni-La and Al-Ni-Gd systems using topological instability and electronegativity

A new criterion has been recently proposed combining the topological instability (lambda criterion) and the average electronegativity difference (Delta e) among the elements of an alloy to predict and select new glass-forming compositions. In the present work, this criterion (lambda.Delta e) is applied to the Al-Ni-La and Al-Ni-Gd ternary systems and its predictability is validated using literature data for both systems and additionally, using own experimental data for the Al-La-Ni system. The compositions with a high lambda.Delta e value found in each ternary system exhibit a very good correlation with the glass-forming ability of different alloys as indicated by their supercooled liquid regions (Delta T(x)) and their critical casting thicknesses. In the case of the Al-La-Ni system, the alloy with the largest lambda.Delta e value, La(56)Al(26.5)Ni(17.5), exhibits the highest glass-forming ability verified for this system. Therefore, the combined lambda.Delta e criterion is a simple and efficient tool to select new glass-forming compositions in Al-Ni-RE systems. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3563099]