University of North Texas

About: University of North Texas is a education organization based out in Denton, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 11866 authors who have published 26984 publications receiving 705376 citations. The organization is also known as: Fight, North Texas & UNT.

Thankful for the little things: A meta-analysis of gratitude interventions

Abstract: A recent qualitative review by Wood, Froh, and Geraghty (2010) cast doubt on the efficacy of gratitude interventions, suggesting the need to carefully attend to the quality of comparison groups. Accordingly, in a series of meta-analyses, we evaluate the efficacy of gratitude interventions (ks = 4-18; Ns = 395-1,755) relative to a measurement-only control or an alternative-activity condition across 3 outcomes (i.e., gratitude, anxiety, psychological well-being). Gratitude interventions outperformed a measurement-only control on measures of psychological well-being (d = .31, 95% confidence interval [CI = .04, .58]; k = 5) but not gratitude (d = .20; 95% CI [-.04, .44]; k = 4). Gratitude interventions outperformed an alternative-activity condition on measures of gratitude (d = .46, 95% CI [.27, .64]; k = 15) and psychological well-being (d = .17, 95% CI [.09, .24]; k = 20) but not anxiety (d = .11, 95% CI [-.08, .31]; k = 5). More-detailed subdivision was possible on studies with outcomes assessing psychological well-being. Among these, gratitude interventions outperformed an activity-matched comparison (d = .14; 95% CI [.01, .27]; k = 18). Gratitude interventions performed as well as, but not better than, a psychologically active comparison (d = -.03, 95% CI [-.13, .07]; k = 9). On the basis of these findings, we summarize the current state of the literature and make suggestions for future applied research on gratitude. (PsycINFO Database Record

Fundamental Theory of Biodegradable Metals—Definition, Criteria, and Design

Abstract: Until now there has been no fundamental theory applicable for biodegradable metals (BMs). First, this paper optimizes the definition of BMs given in 2014. Second, the dual criteria of biodegradability and biocompatibility are proposed for BMs, and all metallic elements in the periodic table with accessible data are screened on the basis of these criteria. Regarding biodegradability, electrode potential, reactivity series, galvanic series, Pilling–Bedworth ratio, and Pourbaix diagrams are all adopted as parameters to classify the degradable and nondegradable nature of a material, especially in a physiological environment. Considering the biocompatibility at different levels, cellular biocompatibility, tissue biocompatibility, and human/clinical related biocompatibility parameters are put forward to comprehensively evaluate the biosafety of BMs. Third, for the material design of BMs, mechanical properties, chemical properties, physical properties and biological properties should be considered and balanced to guarantee that the degradation behavior of BMs match well with a tissue regeneration/repair procedure as the function of time and spatial location. Besides the selected metallic elements, some nonmetallic elements are selected as suitable alloying elements for BMs. Finally, five classification/research directions for future BMs are proposed: biodegradable pure metals, crystalline alloys, bulk metallic glasses, high entropy alloys, and metal matrix composites.

A search model for topological insulators with high-throughput robustness descriptors

Abstract: Topological insulators exhibit intriguing electronic properties that originate from protected metallic states on their surface. Experimental studies so far are based on a limited number of materials. A high-throughput approach now shows how to search for topological insulators in a variety of unexplored classes of materials.

Sliding wear, viscoelasticity, and brittleness of polymers

Abstract: We have connected viscoelastic recovery (healing) in sliding wear to free volume in polymers by using pressure-volume-temperature (P-V-T) results and the Hartmann equation of state. A linear relationship was found for all polymers studied with a wide variety of chemical structures, except for polystyrene (PS). Examination of the effect of the indenter force level applied in sliding wear on the healing shows that recovery is practically independent of that level. Strain hardening in sliding wear was observed for all materials except PS, the exception attributed to brittleness. Therefore, we have formulated a quantitative definition of brittleness in terms of elongation at break and storage modulus. Further, we provide a formula relating the brittleness to sliding wear recovery; the formula is obeyed with high accuracy by all materials including PS. High recovery values correspond to low brittleness, and vice versa. Our definition of brittleness can be used as a design criterion for choosing polymers for specific applications.