Effective thermal conductivity of helium II: from Landau to Gorter-Mellink regimes

The size-dependent and flux-dependent effective thermal conductivity of narrow channels filled with He II is analyzed. The classical Landau evaluation of the effective thermal conductivity of quiescent He II is extended to describe the transition to fully turbulent regime, where the heat flux is proportional to the cubic root of the temperature gradient (Gorter-Mellink regime). To do so we use an expression for the quantum vortex line density $L$ in terms of the heat flux considering the influence of the walls. From it, and taking into account the friction force of normal component against the vortices, we compute the effective thermal conductivity

The Relationship between Self-regulation and Perceived Autonomy of Psychological Well-being among Fifth Grade Christian Private School Students

Increased anxiety, depression, and maladaptive ways of coping among children are evidence of an increase in poor psychological well-being. The purpose of this predictive correlational study was to examine the theory of self-determination that relates natural and intrinsic tendencies of students to behave in an effective and healthy autonomy-supportive way, by examining the predictive relationship of perceived autonomy-support, self-regulation, and psychological well-being of fifth grade Christian private school students. The criterion variable was defined as psychological well-being in this study. The predictor variables were perceived autonomy-support and self-regulation. Data were collected to facilitate this study from 124 fifth grade students using three Likert-type survey instruments. Surveys were distributed and conducted near the end of a school quarter. The results of the research were analyzed using multiple regression. Results indicated that the multiple regression model statistically significantly predicted well-being; however, only perceived autonomy added significantly to the prediction

A non-local model of thermal energy transport: The fractional temperature equation

Non-local models of thermal energy transport have been used in recent physics and engineering applications to describe several "small-scale" and/or high frequency thermodynamic processes as shown in several engineering and physics applications. The aim of this study is to extend a recently proposed fractional-order thermodynamics ([5]), where the thermal energy transfer is due to two phenomena: A short-range heat flux ruled by a local transport equation; a long-range thermal energy transfer that represents a ballistic effects among thermal energy propagators. Long-range thermal energy transfer accounts for small-scale effects that are assumed proportional to the product of the interacting masses, to a distance-decaying function, as well as to their relative temperature. In this paper the thermodynamic consistency of the model is investigated obtaining some restrictions on the functional class of the distance decaying function that rules the strength of the long-range thermal energy transfer. As the distance-decaying function is assumed in the form of a power-law decay a novel temperature equation involving multidimensional spatial Marchaud α-order derivatives (0 ≤ α ≤ 1) of the temperature field in the body is obtained. Some analytical and numerical solutions of the fractional-order temperature equation have been provided in the paper to show the capabilities of the proposed model and the influence of model parameter

Inhomogeneous vortex tangles in counterflow superfluid turbulence: flow in convergent channels

We investigate the evolution equation for the average vortex length per unit volume L of superfluid turbulence in inhomogeneous flows. Inhomogeneities in line density L and in counterflow velocity V may contribute to vortex diffusion, vortex formation and vortex destruction. We explore two different families of contributions: those arising from a second order expansion of the Vinen equation itself, and those which are not related to the original Vinen equation but must be stated by adding to it second-order terms obtained from dimensional analysis or other physical arguments

Complementary and alternative medicine use and absenteeism among individuals with chronic disease

Background It is estimated that over half of the adult U.S. population currently has one or more chronic conditions, resulting in up to an estimated $1,600 in productivity loss annually for each employee with chronic disease. Previous studies have suggested that integrating alternative or complementary health approaches with conventional medicine may be beneficial for managing the symptoms, lifestyle changes, treatment, physical and psychosocial consequences that result from chronic illness. Methods Using the 2012 National Health Interview Survey Data, we examined the associations between self-reported use of various forms of complementary and alternative medicine (CAM) therapies (dietary supplements, mind-body practices) and the number of days missed from job or business in the past 12 months due to illness or injury. Multivariable Poisson regression was used to determine the association between CAM use and absence from work among individuals with one or more chronic disease (n = 10,196). Results Over half (54 %) of the study population reported having one chronic disease, while 19 % had three or more conditions. The three most common chronic diseases were high cholesterol (48 %), arthritis (35 %) and hypertension (31 %). More participants used dietary supplements (72 %) while fewer individuals reported using mind-body practices (17 %) in the past twelve months. Over half of individuals reported missing any number of days from job or business due to illness or injury (53 %). Of those who had missed any days from work, 42 % missed one or two days, 36 % missed three to five days, and 23 % missed six days or more. The rate of missing days from job or business due to injury or illness increased among those who reported use of mind-body practices (Incidence Rate Ratio (IRR) = 1.55, 95 % CI: 1.09, 2.21). There was no association between use of dietary supplements and absenteeism (IRR = 1.13, 95 % CI: 0.85, 1.51). Conclusions In a population of individuals with chronic disease, individuals who reported use of mind-body practices had higher rate of absenteeism due to injury or illness. Future studies should examine the effects CAM on symptoms associated with chronic disease and whether managing these symptoms can reduce absence from work, school, and other responsibilities. Keywords Dietary supplements Mind-body practices Complementary and alternative medicine Employee health Absenteeism Chronic diseas

Scaling Testing of Refactoring Engines

Defining and implementing refactorings is a nontrivial task since it is difficult to define preconditions to guarantee that the transformation preserves the program behavior. Therefore, refactoring engines may apply incorrect transformations in which the resulting program does not compile, preserve behavior, or follow the refactoring definitions. These engines may also prevent correct transformations due to overly strong preconditions. We find that 84% of the test suites of Eclipse and JRRT are concerned to detect those kinds of bugs. However, the engines still have them. Researchers have proposed a number of techniques for testing refactoring engines. Nevertheless, they may have limitations related to the bug type, program generation, time consumption, and number of refactoring engines necessary to evaluate the implementations. We propose and implement a technique to scale testing of refactoring engines. We improve expressiveness of a program generator and use a technique to skip some test inputs to improve performance. Moreover, we propose new oracles to detect behavioral changes using change impact analysis, overly strong preconditions by disabling preconditions, and transformation issues. We evaluate our technique in 28 refactoring implementations of Java (Eclipse and JRRT) and C (Eclipse) and find 119 bugs. The technique reduces the time in 96% using skips while missing only 6% of the bugs. Additionally, it finds the first failure in general in a few seconds using skips. Finally, we evaluate our proposed technique by using other test inputs, such as the input programs of Eclipse and JRRT refactoring test suites. We find 31 bugs not detected by the developers.Sociedad Argentina de Informática e Investigación Operativa (SADIO

The Windows Are Open

Regarding my work, I intend to create situations that provide an opportunity to connect with the natural world . Experiences I have had serve as a source for inspiration. With each recollection of these experiences I assess the particular situations' ability to appeal to the senses. I strip down familiar, tangible qualities and focus on sensual qualities. Such a focus allows for the perception or knowledge of something not generally realized. I want to explore the natural inclination we have to move from darkness toward light. I find the staircase Bernini designed for the Vatican an interesting example. A source of bright light at the top of the stairs guides one ascending the staircase. Bernini exploits human inclination by designing a structure with little light at the bottom and massive amounts at the top. &nbsp;</p

Vortex density waves and high-frequency second sound in superfluid turbulence hydrodynamics

In this paper we show that a recent hydrodynamical model of superfluid turbulence describes vortex density waves and their effects on the speed of high-frequency second sound. In this frequency regime, the vortex dynamics is not purely diffusive, as for low frequencies, but exhibits ondulatory features, whose influence on the second sound is here explored.Comment: 8 page