Verification of the proteus two-dimensional Navier-Stokes code for flat plate and pipe flows

The Proteus Navier-Stokes Code is evaluated for 2-D/axisymmetric, viscous, incompressible, internal, and external flows. The particular cases to be discussed are laminar and turbulent flows over a flat plate, laminar and turbulent developing pipe flows, and turbulent pipe flow with swirl. Results are compared with exact solutions, empirical correlations, and experimental data. A detailed description of the code set-up, including boundary conditions, initial conditions, grid size, and grid packing is given for each case

Modeling salt-fingering structures

Results are presented of calculations with a second-order turbulence model which has been modified to evolve continuously from full turbulent convection to thermo-haline convection, under appropriate circumstances. A three-layer system is simulated, with a salt-fingering interface between two convectively-driven turbulent layers. Experimental results on the salt/heat flux ratio are reproduced

Privacy-preserving security solution for cloud services

AbstractWe propose a novel privacy-preserving security solution for cloud services. Our solution is based on an efficient non-bilinear group signature scheme providing the anonymous access to cloud services and shared storage servers. The novel solution offers anonymous authenticationfor registered users. Thus, users' personal attributes (age, valid registration, successful payment) can be proven without revealing users' identity, and users can use cloud services without any threat of profiling their behavior. However, if a user breaks provider's rules, his access right is revoked. Our solution provides anonymous access, unlinkability and the confidentiality of transmitted data. We implement our solution as a proof of concept applicationand present the experimental results. Further, we analyzecurrent privacy preserving solutions for cloud services and group signature schemes as basic parts of privacy enhancing solutions in cloud services. We compare the performance of our solution with the related solutionsand schemes

Children\u27s Experiences of Maternal Incarceration-Specific Risks: Predictions to Psychological Maladaptation

Children of incarcerated mothers are at increased risk for social and emotional difficulties, yet few studies have investigated potential mechanisms of risk within this population. This research simultaneously examined the association of children\u27s experience of incarceration-specific risk factors (e.g., witness mother\u27s arrest) and environmental risks (e.g., low educational attainment) to children\u27s psychological maladaptation using a multi-informant design and a latent variable analytic approach. Participants were 117 currently incarcerated mothers (64.1% African American), their 151 children (53.6% boys, M age=9.8 years, range=6-12 years, 61.7% African American), and the 118 caregivers (74.8% female, 61.9% grandparents, 62.2% African American) of the children. Mothers, children, and caregivers each provided accounts of children\u27s experiences related to maternal incarceration and children\u27s internalizing and externalizing behavior problems. Mothers and caregivers each supplied information about 10 environmental risk factors. Findings from structural equation modeling indicate that children\u27s incarceration-specific risk experiences predict internalizing and externalizing behavior problems whereas the influence of environmental risks was negligible. Follow-up analyses examining the contribution of specific risks indicate that significant predictors differ by reporter and separate into effects of family incarceration history and direct experiences of maternal incarceration. Incarceration-specific experiences place children at higher risk for maladjustment than exposure to general environmental risk factors. These findings indicate the need to critically examine children\u27s exposure to experiences related to maternal incarceration and family incarceration history to help to clarify the multifaceted stressor of maternal incarceration

Children’s Strategies for Displaying Anger and Sadness: What Works With Whom?

This study examined the influence of expressive strategies (i.e., verbal, facial, crying, sulking, and aggressive), emotion type (i.e., anger, sadness), social context (i.e., mother, father, best friend), age (i.e., 7, 10 years), and gender on 144 children’s expectancies regarding interpersonal responses to their emotional expression. Participants included 72 boys and 72 girls, with an average age of 8 years and 10 months. Results indicate that children expect others to respond more positively to certain expressive strategies (e.g., verbal, facial) as compared to others (e.g., aggression) and that these expectancies vary as a function of the type of emotion experienced, the social context, age, and gender. Consistent with the functionalist approach to emotion, findings suggest that, through social interaction, children learn culturally appropriate strategies for emotional expression that facilitate their ability to elicit a desired response from social partners

Calculation of mechanical and thermal influences during coiling of hot strip

Coiled steel strip is the final product from flat hot rolling processes. With increasing demand for higher quality of hot rolled strips, especially the evolution of strip flatness during and after coiling becomes a crucial aspect. The main impacts on the flatness properties of hot rolled strips result from residual stresses and “eigen-strains” induced by the last hot rolling passes, by strip cooling at the run-out table, and finally, by the mechanical and thermal conditions during and after the coiling process itself. In this paper, a mathematical model is presented, which takes into account the mechanical and thermal effects on hot rolled strip during and after the coiling process. To improve the prediction quality of the underlying process, a customized self-developed 3D finite-element model has been developed and programmed in C++, leading to a software prototype, which is highly superior to commercial FEM-packages with respect to calculation time and storage capacities. The model is based on a dynamic implicit total Lagrangian formulation. All relevant devices directly interacting with the strip, such as pinch rolls, coiler rolls and mandrel are incorporated in the calculation model. Well known and established methods in the solid-shell theory, like the EAS- and ANS-method, were applied to prevent the occurrence of locking phenomena resulting from low order interpolation functions. Selected benchmark tests were performed to evaluate the accuracy of these novel solid-shell elements in comparison to the results attained by the FEM- package ABAQUS©. The results obtained so far agree very satisfactorily. A further important topic is the contact and friction algorithm, where Coulomb’s friction law is applied. The accurate and reliable determination of the contact between strip and interacting devices as well as the aspect of self-contact was treated by applying a sophisticated two dimensional contact search algorithm, leading to a significantly reduced calculation time. The highly non-linear time-dependent system of equations is integrated by utilizing the (implicit) Newmark time-integration scheme. The developed calculation model serves as an effective tool to predict the interesting stress-distributions and local plastic deformations inside the strip, which induce residual stresses and strip unflatness (latent or even manifest waviness). Furthermore, this tool p ovides the basis for further improvements and investigations on hot rolling production lines

How do older people discuss their own sexuality? A systematic review of qualitative research studies

This study captured older people’s attitudes and concerns about sex and sexuality in later life by synthesising qualitative research published on this issue. The systematic review was conducted between November 2015 and June 2016 based on a pre-determined protocol. Key words were used to ensure a precise search strategy. Empirically based, qualitative literature from 18 databases was found. Twenty studies met the inclusion criteria. Thomas and Harden’s thematic synthesis was used to generate ‘analytical themes’ which summarise this body of literature. Three main themes were identified: (a) social legitimacy for sexuality in later life; (b) health, not age, is what truly impacts sexuality, and (c) the hegemony of penetrative sex. The themes illustrate the complex and delicate relation between ageing and sexuality. Older adults facing health issues that affect sexual function adopt broader definitions of sexuality and sexual activit

Effectiveness of an Intensive Drowning Prevention Program and Skills Retention by Children with and without Disabilities

This study examined the effectiveness of a drowning prevention program and the retention of swimming and water safety skills for 3-14 year-old children with and without disabilities. The intensive program, SWIM Central, used a top-down approach to teach 6 swimming and water safety skills during 10, 30-minute sessions. A post-participation parent survey results suggested that children ages 3-14 with and without disabilities who had previously participated in SWIM Central retained swimming and water safety skills to a similar degree. The current swim skill assessments showed that there was not an overall difference in swim skill performance in the presence of a disability; therefore, the SWIM Central program was effective in increasing overall swimming performance for children with and without disabilities

Microstructural enrichment functions based on stochastic Wang tilings

This paper presents an approach to constructing microstructural enrichment functions to local fields in non-periodic heterogeneous materials with applications in Partition of Unity and Hybrid Finite Element schemes. It is based on a concept of aperiodic tilings by the Wang tiles, designed to produce microstructures morphologically similar to original media and enrichment functions that satisfy the underlying governing equations. An appealing feature of this approach is that the enrichment functions are defined only on a small set of square tiles and extended to larger domains by an inexpensive stochastic tiling algorithm in a non-periodic manner. Feasibility of the proposed methodology is demonstrated on constructions of stress enrichment functions for two-dimensional mono-disperse particulate media.Comment: 27 pages, 12 figures; v2: completely re-written after the first revie