Giant room temperature elastocaloric effect in metal-free thin-film perovskites

Solid-state refrigeration which is environmentally benign has attracted considerable attention. Mechanocaloric (mC) materials, in which the phase transitions can be induced by mechanical stresses, represent one of the most promising types of solid-state caloric materials. Herein, we have developed a thermodynamic phenomenological model and predicted extraordinarily large elastocaloric (eC) strengths for the (111)-oriented metal-free perovskite ferroelectric [MDABCO](NH4)I3 thin-films. The predicted room temperature isothermal eC ΔSeC/Δσ (eC entropy change under unit stress change) and adiabatic eC ΔTeC/Δσ (eC temperature change under unit stress change) for [MDABCO](NH4)I3 are −60.0 J K−1 kg−1 GPa−1 and 17.9 K GPa−1, respectively, which are 20 times higher than the traditional ferroelectric oxides such as BaTiO3 thin films. We have also demonstrated that the eC performance can be improved by reducing the Young’s modulus or enhancing the thermal expansion coefficient (which could be realized through chemical doping, etc.). We expect these discoveries to spur further interest in the potential applications of metal-free organic ferroelectrics materials towards next-generation eC refrigeration devices.

Deformation Failure and Gas Seepage of Raw Coal in Alternate Loading and Unloading by Stages

In this paper, the cyclic loading and unloading confining pressure tests of raw coal samples were carried out by using the "Triaxial seepage test device of thermal fluid solid of coal and rock" developed by Chongqing University. The conclusions are as follows: (1) The axial strain change rate ε1´, the radial strain change rate ε3´ and the permeability change rate k´ under unit stress state are used to represent the sensitivity of axial stress and confining pressure to deformation and permeability characteristics of samples under unit stress state. (2) At the initial stage of unloading the confining pressure, the confining pressure has a greater influence on the permeability of the sample. At the initial stage of loading confining pressure, the confining pressure has a greater influence on the radial strain of the specimen. During the subsequent loading and unloading process, the confining pressure of loading and unloading has a greater influence on the permeability of the sample, and a smaller influence on the axial strain. The loading axial stress has a greater influence on the axial strain of the sample, and a smaller influence on the permeability of the sample. (3) When the axial stress is constant, the increase range of sample permeability increases with the increase of unloading confining pressure range, and the decreasing range of sample permeability increases with the increase of loading confining pressure range, and the increase range of sample permeability under unloading confining pressure is higher than that under increasing confining pressure. (4) In the process of loading axial stress and loading confining pressure, the permeability of samples decreases nonlinearly with the increase of principal stress difference, while the permeability of samples increases nonlinearly with the decrease of principal stress difference in the process of unloading confining pressure.

Uporaba in učinkovitost glasbene terapije v enoti intenzivne terapije

Uvod: Uporaba glasbe v terapevtske namene je neinvazivna intervencija, ki v bolnišničnem okolju lahko ugodno vpliva na pacientovo psihofizično stanje, vendar v vsakdanji obravnavi pacientov ni uveljavljena. Zato je bil namen raziskave preučiti uporabo in učinkovitost glasbene terapije glede na doživljanje bolečine ali stresa pri pacientih, hospitaliziranih v enotah intenzivne terapije.Metode: Izveden je bil sistematični pregled znanstvene literature v mednarodnih podatkovnih bazah: PubMed, CINAHL, Cochrane Library, ScienceDirect, Wiley Online Library z uporabo ključnih besed v angleškem jeziku »music therapy«, »intensive care unit«, »stress«, »anxiety«, »pain« ter upoštevanjem vključitvenihin izključitvenih kriterijev. Potek pregleda literature je prikazan s pomočjo diagrama PRISMA. Kakovost raziskav, vključenih v končno analizo, je bila ocenjena s pomočjo orodja Scottish Intercollegiate Guidelines Network. Rezultati so sintetizirani z uporabo metode analize vsebine.Rezultati: Izmed 749 identificiranih zadetkov je bilo v končno analizo vključenih 13 raziskav. Raziskave kažejo učinkovitost glasbene terapije pri lajšanju bolečin, poglobitvi sedacije, uravnavanju fizioloških parametrov ter zmanjšanju strahu in anksioznosti pri hospitaliziranih pacientih v enotah intenzivne terapije.Diskusija in zaključek: Glasbena terapija je v medsebojnem dopolnjevanju s farmakološkimi ukrepi primerna intervencija za obvladovanje bolečine in stresa. Primanjkuje dokazov o optimalnem trajanju, zvrsti glasbe in načinu izvajanja glasbene terapije za doseganje najboljših rezultatov.

Following an Uneven Lead: Trickle-Down Effects of Differentiated Transformational Leadership

Drawing from conservation-of-resources theory, we examine a trickle-down model of differentiated transformational leadership (leaders treating followers differently) across three hierarchical levels (i.e., managers, supervisors, and supervisors’ followers). Specifically, we develop a model in which manager differentiated transformational leadership increases department unit stress (i.e., the managers’ group of followers), which then translates into increased differentiated supervisor transformational leadership. The latter then again positively predicts team unit stress (i.e., the supervisors’ group of followers) and, eventually, results in decreased team helping behavior of supervisors’ followers. We tested this model using data from a large, multisource field study. The results provide support for our trickle-down model in that department managers’ differentiated transformational leadership decreased team helping behavior two hierarchical levels below the manager via increasing department unit stress (Stage 1 mediator), supervisor differentiated transformational leadership (Stage 2 mediator), and team unit stress (Stage 3 mediator).

Stress-Strength Reliability Model with The Exponentiated Weibull Distribution: Inferences and Applications

In this paper, we deal with the estimation of the reliability $R=P(Y<X)$ where $X$, a unit strength, and $Y$, a unit stress, are independent exponentiated Weibull random variables. The maximum likelihood and Bayesian methods are used to make inference about $R$. We obtain the Baysian estimator using Lindely's procedure under squared error loss and LINEX loss functions with gamma prior for the unknown model parameters. The asymptotic and bootstrap confidence intervals are obtained as well as the credible interval for R is constructed in view of the empirical Bayesian procedure. For illustrative purposes, analysis of real data sets is presented. Mont Carlo simulations are carried out to compare the performances of the different estimators.

The lingering effects of work context: Ambient work-unit characteristics and the impact of retirement on alcohol consumption

Although it is well established that workplace demands and culture can affect employee well-being, to what degree might these same factors have lingering implications on individual well-being after employees retire? To begin to answer this question, in this article we propose and test a model explaining how retiree alcohol consumption may depend on pre-retirement contextual conditions. Specifically, we propose and test a moderated-mediation model in which two ambient work-unit characteristics – work-unit stress climate and work-unit drinking norms – moderate the indirect effects of retirement, via distress, on modal alcohol consumption (i.e. the typical quantity and frequency of alcohol consumed). Using a prospective study design and a multi-level, zero-inflated negative binomial model for predicting modal alcohol consumption, our findings lend partial support for the proposed model. We found retirement (vs continued employment) to be associated with a heightened probability of being an abstainer after retirement eligibility (i.e. at Time 2), regardless of the hypothesized unit-level moderators. Still, retirement had mixed effects on the level of modal consumption among those not abstaining at Time 2, with these effects being partially mediated by distress and contingent upon unit-level stress climate and unit-level drinking norms.