Determining and modelling a complete time-temperature-transformation diagram for a Pt-based metallic glass former through combination of conventional and fast scanning calorimetry

State of the art fast differential scanning calorimetry (FDSC) is used to complement conventional differential scanning calorimetry (DSC) studies about the isothermal time-temperature-transformation (TTT) diagram of the bulk metallic glass forming liquid Pt42.5Cu27Ni9.5P21 to allow a comprehensive study of the crystallization kinetics of this system over a broad temperature range. FDSC and DSC data align well in the low-temperature region of the crystallization nose but show distinct discrepancies in the high-temperature region as the FDSC studies reveal faster crystallization times. The results are mathematically described and discussed based on the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation. Thereby, either homogeneous or heterogeneous nucleation is assumed, depending on the respective experimental conditions in FDSC and DSC studies. With this approach, the complete TTT diagram can be modelled as superposition of two sequential JMAK fits

Sparse-Lagrangian PDF Modelling of Silica Synthesis from Silane Jets in Vitiated Co-flows with Varying Inflow Conditions

This paper presents a comparison of experimental and numerical results for a series of turbulent reacting jets where silica nanoparticles are formed and grow due to surface growth and agglomeration. We use large-eddy simulation coupled with a multiple mapping conditioning approach for the solution of the transport equation for the joint probability density function of scalar composition and particulate size distribution. The model considers inception based on finite-rate chemistry, volumetric surface growth and agglomeration. The sub-models adopted for these particulate processes are the standard ones used by the community. Validation follows the “paradigm shift” approach where elastic light scattering signals (that depend on particulate number and size), OH- and SiO-LIF signals are computed from the simulation results and compared with “raw signals” from laser diagnostics. The sensitivity towards variable boundary conditions such as co-flow temperature, Reynolds number and precursor doping of the jet is investigated. Agreement between simulation and experiments is very good for a reference case which is used to calibrate the signals. While keeping the model parameters constant, the sensitivity of the particulate size distribution on co-flow temperature is predicted satisfactorily upstream although quantitative differences with the data exist downstream for the lowest coflow temperature case that is considered. When the precursor concentration is varied, the model predicts the correct direction of the change in signal but notable qualitative and quantitative differences with the data are observed. In particular, the measured signals show a highly non-linear variation while the predictions exhibit a square dependence on precursor doping at best. So, while the results for the reference case appear to be very good, shortcomings in the standard submodels are revealed through variation of the boundary conditions. This demonstrates the importance of testing complex nanoparticle synthesis models on a flame series to ensure that the physical trends are correctly accounted for

Validade do instrumento WHO VAW STUDY para estimar violência de gênero contra a mulher

OBJECTIVE: To validate the instrument of the World Health Organization Violence Against Women (WHO VAW) study on psychological, physical and sexual violence against women perpetrated by intimate partners. METHODS: This was a cross-sectional study conducted in several countries between 2000 and 2003, including Brazil. Representative random samples of women aged 15-49 years with intimate partners were selected, living in the city of São Paulo (n = 940) and in the Zona da Mata, Pernambuco (n = 1,188), southeastern and northeastern regions, respectively. Exploratory factor analysis on questions relating to violence was performed (four psychological, six physical and three sexual questions), with varimax rotation and creation of three factors. Cronbach's alpha was calculated to analyze the internal consistency. To validate through extreme groups, mean scores (0 to 13 points) for violence were tested in relation to the following outcomes: self-rated health, daily activities, presence of discomfort or pain, suicidal ideation or attempts, heavy alcohol consumption and presence of common mental disorders. RESULTS: Three factors were defined, with similar accumulated variance (0.6092 in São Paulo and 0.6350 in the Zona da Mata). For São Paulo, the first factor was determined by physical violence, the second by sexual violence and the third by psychological violence. For the Zona da Mata, the first factor was formed by psychological violence, the second by physical violence and the third by sexual violence. Cronbach's alpha coefficients were 0.88 in São Paulo and 0.89 in the Zona da Mata. The mean scores for violence were significantly higher for less favorable outcomes, with the exception of suicide attempts in São Paulo. CONCLUSIONS: The instrument was shown to be adequate for estimating gender-based violence against women perpetrated by intimate partners and can be used in studies on this subject. It has high internal consistency and a capacity to discriminate between different forms of violence (psychological, physical and sexual) perpetrated in different social contexts. The instrument also characterizes the female victim and her relationship with the aggressor, thereby facilitating gender analysis.OBJETIVO: Validar preguntas sobre violencia psicológica, física y sexual por parejas íntimas contra mujeres. MÉTODOS: Estudio transversal, coordinado por la Organización Mundial de la Salud, realizado en varios países (2000-2003), inclusive Brasil. Se seleccionaron muestras aleatorias y representativas de mujeres de 15-49 años con parejas íntimas, residentes, en la ciudad de Sao Paulo (en Sureste de Brasil, n=940) y en la Zona de Mata de Pernambuco (en Noreste de Brasil, n=1188). Se realizó análisis factorial exploratorio de las preguntas sobre violencias (cuatro psicológicas, seis físicas y tres sexuales), con rotación varimax y elaboración de tres factores. Se calculó alfa de Cronbach para análisis de la consistencia interna. Para la validación por grupos extremos, promedios de escores (cero a 13 puntos) de violencia fueron evaluadas con relación a los resultados: auto-evaluación de salud, actividades diarias, presencia de dolor o incomodidad, concepción de idea e intento de suicidio, grande consumo de alcohol y presencia de trastorno mental común. RESULTADOS: Fueron definidos tres factores con varianza acumulada semejante (0,6092 en Sao Paulo y 0,6350 en la Zona de Mata). Para Sao Paulo, el primer factor fue determinado por la violencia física, el segundo por la sexual y el tercero por la psicológica. Para la Zona de Mata, el primer factor estuvo compuesto por la violencia psicológica, el segundo por la física y el tercero por la sexual. Coeficientes de alfa de Cronbach fueron 0,88 en Sao Paulo y 0,89 en la Zona de Mata. Los promedios de los escores de violencia fueron significativamente mayores para resultados menos favorables, excepto intento de suicidio en Sao Paulo. CONCLUSIONES: El instrumento se mostró adecuado para estimar la violencia de género contra la mujer perpetrada por su pareja íntima y puede ser utilizado en estudios sobre el tema. El mismo tiene alta consistencia interna y capacidad de discriminar las formas de violencia psicológica, física y sexual, perpetrada en contextos sociales diversos. El instrumento también caracteriza a la mujer agredida y su relación con el agresor, facilitando análisis de género.OBJETIVO: Validar o instrumento do estudo World Health Organization Violence Against Women (WHO VAW) sobre violência psicológica, física e sexual por parceiros íntimos contra mulheres. MÉTODOS: Estudo transversal realizado em vários países entre 2000 e 2003, inclusive Brasil. Selecionaram-se amostras aleatórias e representativas de mulheres de 15-49 anos com parceiros íntimos, residentes na cidade de São Paulo, SP, (n = 940) e na Zona da Mata de Pernambuco (n = 1.188). Realizou-se análise fatorial exploratória das perguntas sobre violências (quatro psicológicas, seis físicas e três sexuais), com rotação varimax e criação de três fatores. Calculou-se alfa de Cronbach para análise da consistência interna. Para a validação por grupos extremos, médias de escores (zero a 13 pontos) de violência foram testadas em relação aos desfechos: auto-avaliação de saúde, atividades diárias, presença de dor ou desconforto, ideação e tentativa de suicídio, grande consumo de álcool e presença de transtorno mental comum. RESULTADOS: Foram definidos três fatores com variância acumulada semelhante (0,6092 em São Paulo e 0,6350 na Zona da Mata). Para São Paulo, o primeiro fator foi determinado pela violência física, o segundo pela sexual e o terceiro pela psicológica. Para a Zona da Mata, o primeiro fator foi composto pela violência psicológica, o segundo pela física e o terceiro pela sexual. Coeficientes de alfa de Cronbach foram 0,88 em São Paulo e 0,89 na Zona da Mata. As médias dos escores de violência foram significativamente maiores para desfechos menos favoráveis, exceto tentativa de suicídio em São Paulo. CONCLUSÕES: O instrumento mostrou-se adequado para estimar a violência de gênero contra a mulher perpetrada por seu parceiro íntimo e pode ser utilizado em estudos sobre o tema. Ele tem alta consistência interna e capacidade de discriminar as formas de violência psicológica, física e sexual, perpetrada em contextos sociais diversos. O instrumento também caracteriza a mulher agredida e sua relação com o agressor, facilitando análises de gênero

Macroscopic Manifestation of Domain-wall Magnetism and Magnetoelectric Effect in a N\'eel-type Skyrmion Host

We report a magnetic state in GaV$_4$Se$_8$ which emerges exclusively in samples with mesoscale polar domains and not in polar mono-domain crystals. Its onset is accompanied with a sharp anomaly in the magnetic susceptibility and the magnetic torque, distinct from other anomalies observed also in polar mono-domain samples upon transitions between the cycloidal, the N\'eel-type skyrmion lattice and the ferromagnetic states. We ascribe this additional transition to the formation of magnetic textures localized at structural domain walls, where the magnetic interactions change stepwise and spin textures with different spiral planes, hosted by neighbouring domains, need to be matched. A clear anomaly in the magneto-current indicates that the domain-wall-confined magnetic states also have strong contributions to the magnetoelectric response. We expect polar domain walls to commonly host such confined magnetic edge states, especially in materials with long wavelength magnetic order

Microstructural length scale parameters to model the high-cycle fatigue behaviour of notched plain concrete

The present paper investigates the importance and relevance of using microstructural length scale parameters in estimating the high-cycle fatigue strength of notched plain concrete. In particular, the accuracy and reliability of the Theory of Critical Distances and Gradient Elasticity are checked against a number of experimental results generated by testing, under cyclic bending, square section beams of plain concrete containing stress concentrators of different sharpness. The common feature of these two modelling approaches is that the required effective stress is calculated by using a length scale which depends on the microstructural material morphology. The performed validation exercise demonstrates that microstructural length scale parameters are successful in modelling the behaviour of notched plain concrete in the high-cycle fatigue regime

Prevalence of Disorders Recorded in Dogs Attending Primary-Care Veterinary Practices in England

Purebred dog health is thought to be compromised by an increasing occurence of inherited diseases but inadequate prevalence data on common disorders have hampered efforts to prioritise health reforms. Analysis of primary veterinary practice clinical data has been proposed for reliable estimation of disorder prevalence in dogs. Electronic patient record (EPR) data were collected on 148,741 dogs attending 93 clinics across central and south-eastern England. Analysis in detail of a random sample of EPRs relating to 3,884 dogs from 89 clinics identified the most frequently recorded disorders as otitis externa (prevalence 10.2%, 95% CI: 9.1-11.3), periodontal disease (9.3%, 95% CI: 8.3-10.3) and anal sac impaction (7.1%, 95% CI: 6.1-8.1). Using syndromic classification, the most prevalent body location affected was the head-and-neck (32.8%, 95% CI: 30.7-34.9), the most prevalent organ system affected was the integument (36.3%, 95% CI: 33.9-38.6) and the most prevalent pathophysiologic process diagnosed was inflammation (32.1%, 95% CI: 29.8-34.3). Among the twenty most-frequently recorded disorders, purebred dogs had a significantly higher prevalence compared with crossbreds for three: otitis externa (P = 0.001), obesity (P = 0.006) and skin mass lesion (P = 0.033), and popular breeds differed significantly from each other in their prevalence for five: periodontal disease (P = 0.002), overgrown nails (P = 0.004), degenerative joint disease (P = 0.005), obesity (P = 0.001) and lipoma (P = 0.003). These results fill a crucial data gap in disorder prevalence information and assist with disorder prioritisation. The results suggest that, for maximal impact, breeding reforms should target commonly-diagnosed complex disorders that are amenable to genetic improvement and should place special focus on at-risk breeds. Future studies evaluating disorder severity and duration will augment the usefulness of the disorder prevalence information reported herein

A novel reformulation of the Theory of Critical Distances to design notched metals against dynamic loading

In the present study the linear-elastic Theory of Critical Distances (TCD) is reformulated to make it suitable for predicting the strength of notched metallic materials subjected to dynamic loading. The accuracy and reliability of the proposed reformulation of the TCD was checked against a number of experimental results generated by testing, under different loading/strain rates, notched cylindrical samples of aluminium alloy 6063-T5, titanium alloy Ti–6Al–4V, aluminium alloy AlMg6, and an AlMn alloy. To further validate the proposed design method also different data sets taken from the literature were considered. Such an extensive validation exercise allowed us to prove that the proposed reformulation of the TCD is successful in predicting the dynamic strength of notched metallic materials, this approach proving to be capable of estimates falling within an error interval of ±20%. Such a high level of accuracy is certainly remarkable, especially in light of the fact that it was reached without the need for explicitly modelling the stress vs. strain dynamic behaviour of the investigated ductile metals

A stochastic multiple mapping conditioning computational model in OpenFOAM for turbulent combustion

Computational models for combustion must account for complex and inherently interconnected physical processes including dispersion, mixing, chemical reactions, particulate nucleation and growth and, critically, the interactions of these with turbulence. The development of affordable and accurate models that are widely applicable is a work in progress. Stochastic multiple mapping conditioning (MMC) is a fast-emerging approach that has been successfully applied to non-premixed, premixed and partially premixed flames as well to the modelling of liquid and solid particulate synthesis. The method solves the conventional PDF transport equation but incorporates an additional constraint in that the mixing is localised in a reference space. This paper describes the numerical implementation of stochastic MMC in an OpenFOAM compatible code called mmcFoam. The model concepts and equations along with alternative submodels, code structure and numerical schemes are explained. A focus is placed on validation of the computational methods in particular demonstrating numerical convergence and mass consistency of the hybrid Eulerian/Lagrangian schemes. Four validation cases are selected including a combustion direct numerical simulation (DNS) case, two combustion experimental jet flame cases and a non-combusting particulate synthesis case. The results show that the total mass and mass distribution of Eulerian and Lagrangian schemes are consistent and confirm that the solutions numerically converge with increasing number of stochastic computational particles and sections for describing particulate size distribution

Local stress measurement using the thermoelastic effect

A technique for measuring local stresses in metallic specimens is proposed and tested. The technique depends on the experimental measurement of temperature changes in stressed members due to adiabatic elastic deformation. At a free boundary in a body under plane stress, these temperature changes are directly related to the value of the tangential principal stress. The technique is suited for measurement of stress-concentration effects, since the temperature changes can be measured with thermocouples featuring extremely small junctions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43937/1/11340_2006_Article_BF02326342.pd

NDSC Intercomparison of Stratospheric Aerosol Processing Algorithms

Scattering ratios R processed from the same raw data at 353 and 532 nm by different lidar groups agree within about 10 % for high and within about 4 % for low aerosol loading. In the main layer aerosol backscatter coefficients agree within about 30 % for high and within about 40 % for low aerosol loadingPublishedBerlin, Germany1.8. Osservazioni di geofisica ambientaleope