Numerical simulation of non-Newtonian free shear flows

Free shear flows, like those of mixing layers, are encountered in aerodynamics, in the atmosphere, and in the ocean as well as in many industrial applications such as flow reactors or combustion chambers. It is, therefore, crucial to understand the mechanisms governing the process of transition to turbulence in order to predict and control the evolution of the flow. Delaying transition to turbulence as far downstream as possible allows a gain in energy expenditure while accelerating the transition can be of interest in processes where high mixing is desired. Various methods, including the use of polymer additives, can be effective in controlling fluid flows. The drag reduction obtained by the addition of small amounts of high polymers has been an active area of research for the last three decades. It is now widely believed that polymer additives can affect the stability of a large variety of flows and that dilute solutions of these polymers have been shown to produce drag reductions of over 80 percent in internal flows and over 60 percent in external flows under a wide range of conditions. The major thrust of this work is to study the effects of polymer additives on the stability of the incompressible mixing layer through large scale numerical simulations. In particular, we focus on the two dimensional flow and examine how the presence of viscoelasticity may affect the typical structures of the flow, namely roll-up and pairing of vortices

Chaotic versus stochastic behavior in active-dissipative nonlinear systems

We study the dynamical state of the one-dimensional noisy generalized Kuramoto-Sivashinsky (gKS) equation by making use of time-series techniques based on symbolic dynamics and complex networks. We focus on analyzing temporal signals of global measure in the spatiotemporal patterns as the dispersion parameter of the gKS equation and the strength of the noise are varied, observing that a rich variety of different regimes, from high-dimensional chaos to pure stochastic behavior, emerge. Permutation entropy, permutation spectrum, and network entropy allow us to fully classify the dynamical state exposed to additive noise

Planning for Aging in Place: Stimulating a Market and Government Response

Using a national survey of local governments, we explore the drivers of planning and service delivery for older adults. Our regression models find that planning for aging and elder engagement are the most influential factors explaining the level of community services for elders. Services are lower in less dense suburban and rural communities, and market-based services are lower in communities with more senior poverty. This creates two challenges for planners: to help generate a market response for aging services, and to articulate the link between the built environment and services so communities that lack supportive physical environments can become better places to age

Validation of the Finnish FACE-Q for use in patients undergoing surgery for functional problems or malignancy

The aim of this study was to produce a Finnish version of the FACE-Q scales Satisfaction with Forehead and Eyebrows, Adverse effects: Forehead, Eyebrows and Scalp, and Adverse effects: Cheeks, Lower face and Neck, and assess the performance of these scales and the Satisfaction with Facial Appearance, Satisfaction with Outcome and Appearance-related Psychosocial Distress in patients who had undergone surgery for functional problems or malignancy affecting the forehead or cheeks. The general health-related outcomes instrument 15 D was used as a reference. Patients who had undergone a frontal lift, a direct brow lift, a facelift or an excision of a facial tumor in Helsinki University Hospital plastic surgery department in 2009-2019 were identified. A postal survey study was conducted with 305 patients, of whom 135 (44%) responded. Diagnoses included facial nerve dysfunction (53%), brow ptosis (21%) and skin, mucosal or salivary gland tumor (20%). The FACE-Q scales displayed high internal consistency (Cronbach's alphas >= 0.80) and good reliability on repeat administration. The exploratory factor analysis revealed unifactorial influences for all scales except the Adverse effects: Forehead, Eyebrows and Scalp. Weak correlations with 15 D dimensions were detected. The FACE-Q scales evaluated here are suitable for use in patients with functional problems or malignancy.Peer reviewe

Application of the FACE-Q rhinoplasty module in a mixed reconstructive and corrective rhinoplasty population in Finland

The FACE-Q Rhinoplasty module is a patient-reported outcome instrument developed for the assessment of primarily aesthetic outcomes of rhinoplasty. The aim of our study was to produce a Finnish version of the instrument and validate it for use in patients undergoing nasal reconstruction as well as those treated with a rhinoplasty. Finnish versions of the FACE-Q scales Satisfaction with Nose, Satisfaction with Nostrils and Adverse Effects: Nose, were translated following established guidelines. Patients undergoing nasal resection, reconstruction or rhinoplasty in Helsinki University Hospital plastic surgery department in 2009-2019 were identified using theatre records. A total of 240 Finnish-speaking patients 18-85 years old were approached with a postal survey questionnaire. The questionnaire included the translated FACE-Q modules and those for Satisfaction with Facial Appearance, Appearance-Related Psychosocial Distress and Satisfaction with Outcome, as well as the general health-related quality of life instrument 15 D. The FACE-Q scales translated readily to Finnish. Eighty-three patients (35%) responded to the survey. Most FACE-Q scales performed well with high internal consistency (Cronbach's alphas 0.87-0.92) and repeatability. Only the Adverse Effects: Nose scale displayed poor consistency and a floor effect with 18% of the patients reporting no adverse outcomes. Answers to the Appearance-Related Psychosocial Distress scale were skewed towards no experienced stress. Answers to the other scales were normally distributed with weak correlation with 15 D dimensions. The Finnish translations of the FACE-Q Rhinoplasty scales perform well at assessing a diverse group of patients including those undergoing nasal reconstruction as well as those undergoing rhinoplasty.Peer reviewe

Validation of the Finnish version of the BODY-Q patient-reported outcome instrument among patients who underwent abdominoplasty

Background: Massive weight loss can notably affect patients' health-related quality of life (HRQoL) and body image. Yet, no body contouring specific instruments to assess HRQoL and body image after massive weight loss have been validated in Finnish. The BODY-Q includes 26 independently functioning scales and a single checklist that measure appearance, HRQoL, and experience of care. The aim of the present study was to translate and validate a Finnish version of the BODY-Q among patients who underwent abdominoplasty. Methods: The BODY-Q was translated into Finnish using recommended guidelines. Eighty-two patients who underwent abdominoplasty due to massive weight loss were identified from hospital records using procedure codes. A postal survey including the BODY-Q, the 15D, and general health and pain instruments was used. Criterion validity, Cronbach's alpha, and floor and ceiling effects were analyzed. Results: The BODY-Q translated well into Finnish. Fifty-three patients returned the questionnaires (response rate 65%) and were included. All but the Scars subscale correlated significantly with the 15D mean score, thus indicating strong criterion validity against a generic HRQoL tool. The Excess Skin and the Physical Function scales reached the ceiling effect (>15% of maximum points) in our postoperative sample. No floor effects were observed. Internal consistency of the BODY-Q scales was high (Cronbach's alpha range, 0.81-0.95). Conclusions: The Finnish version of the BODY-Q instrument is equivalent in terms of content, accuracy, and comprehensiveness to the original English version. The findings of the present study indicate that the BODY-Q has psychometric properties suitable for assessing outcomes and treatment effectiveness of abdominoplasty. (C) 2019 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Gravity-driven instability in a spherical Hele-Shaw cell

A pair of concentric spheres separated by a small gap form a spherical Hele-Shaw cell. In this cell an interfacial instability arises when two immiscible fluids flow. We derive the equation of motion for the interface perturbation amplitudes, including both pressure and gravity drivings, using a mode coupling approach. Linear stability analysis shows that mode growth rates depend upon interface perimeter and gravitational force. Mode coupling analysis reveals the formation of fingering structures presenting a tendency toward finger tip-sharpening.Comment: 13 pages, 4 ps figures, RevTex, to appear in Physical Review

Rotating Hele-Shaw cells with ferrofluids

We investigate the flow of two immiscible, viscous fluids in a rotating Hele-Shaw cell, when one of the fluids is a ferrofluid and an external magnetic field is applied. The interplay between centrifugal and magnetic forces in determining the instability of the fluid-fluid interface is analyzed. The linear stability analysis of the problem shows that a non-uniform, azimuthal magnetic field, applied tangential to the cell, tends to stabilize the interface. We verify that maximum growth rate selection of initial patterns is influenced by the applied field, which tends to decrease the number of interface ripples. We contrast these results with the situation in which a uniform magnetic field is applied normally to the plane defined by the rotating Hele-Shaw cell.Comment: 12 pages, 3 ps figures, RevTe

De novo mutations in congenital heart disease with neurodevelopmental and other congenital anomalies

Congenital heart disease (CHD) patients have an increased prevalence of extracardiac congenital anomalies (CAs) and risk of neurodevelopmental disabilities (NDDs). Exome sequencing of 1213 CHD parent-offspring trios identified an excess of protein-damaging de novo mutations, especially in genes highly expressed in the developing heart and brain. These mutations accounted for 20% of patients with CHD, NDD, and CA but only 2% of patients with isolated CHD. Mutations altered genes involved in morphogenesis, chromatin modification, and transcriptional regulation, including multiple mutations in RBFOX2, a regulator of mRNA splicing. Genes mutated in other cohorts examined for NDD were enriched in CHD cases, particularly those with coexisting NDD. These findings reveal shared genetic contributions to CHD, NDD, and CA and provide opportunities for improved prognostic assessment and early therapeutic intervention in CHD patients

Experiments of Interfacial Roughening in Hele-Shaw Flows with Weak Quenched Disorder

We have studied the kinetic roughening of an oil--air interface in a forced imbibition experiment in a horizontal Hele--Shaw cell with quenched disorder. Different disorder configurations, characterized by their persistence length in the direction of growth, have been explored by varying the average interface velocity v and the gap spacing b. Through the analysis of the rms width as a function of time, we have measured a growth exponent beta ~= 0.5 that is almost independent of the experimental parameters. The analysis of the roughness exponent alpha through the power spectrum have shown different behaviors at short (alpha_1) and long (alpha_2) length scales, separated by a crossover wavenumber q_c. The values of the measured roughness exponents depend on experimental parameters, but at large velocities we obtain alpha_1 ~= 1.3 independently of the disorder configuration. The dependence of the crossover wavenumber with the experimental parameters has also been investigated, measuring q_c ~ v^{0.47} for the shortest persistence length, in agreement with theoretical predictions.Comment: 20 pages, 22 figure