University of Nebraska–Lincoln

About: University of Nebraska–Lincoln is a education organization based out in Lincoln, Nebraska, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 28059 authors who have published 61544 publications receiving 2139104 citations. The organization is also known as: Nebraska & UNL.

Mechanical Characterizations of 3D-printed PLLA/Steel Particle Composites.

Abstract: The objective of this study is to characterize the micromechanical properties of poly-l-lactic acid (PLLA) composites reinforced by grade 420 stainless steel (SS) particles with a specific focus on the interphase properties. The specimens were manufactured using 3D printing techniques due to its many benefits, including high accuracy, cost effectiveness and customized geometry. The adopted fused filament fabrication resulted in a thin interphase layer with an average thickness of 3 µm. The mechanical properties of each phase, as well as the interphase, were characterized by nanoindentation tests. The effect of matrix degradation, i.e., imperfect bonding, on the elastic modulus of the composite was further examined by a representative volume element (RVE) model. The results showed that the interphase layer provided a smooth transition of elastic modulus from steel particles to the polymeric matrix. A 10% volume fraction of steel particles could enhance the elastic modulus of PLLA polymer by 31%. In addition, steel particles took 37% to 59% of the applied load with respect to the particle volume fraction. We found that degradation of the interphase reduced the elastic modulus of the composite by 70% and 7% under tensile and compressive loads, respectively. The shear modulus of the composite with 10% particles decreased by 36%, i.e., lower than pure PLLA, when debonding occurred.

Gender Socialization in Latino/a Families: Results from Two Retrospective Studies

Abstract: In this article, we present findings from 2 studies designed to explore gender-related socialization in Latino/a families. In Study 1, 22 adult Latinas (ages 20–45) completed in-depth interviews. In Study 2, 166 Latino/a college students (58% women; M age 21.4 years) completed self-report surveys. Study 1 findings suggest that many Latino/a parents socialize their daughters in ways that are marked by “traditional” gender-related expectations and messages. Results of Study 2, which included descriptive analyses and the creation of scales to explore family correlates of gender-related socialization, support and expand these findings. Male and female respondents described different experiences of household activities, socialization of gender-typed behavior, and freedom to pursue social activities or gain access to privileges. Parental characteristics, particularly gender role attitudes, were linked to gender-related socialization. Findings are discussed in light of the developmental and cultural literature on gender-related socialization.

Professional Development in Early Childhood Programs: Process Issues and Research Needs

Abstract: In light of the current policy context, early childhood educators are being asked to have a complex understanding of child development and early education issues and provide rich, meaningful educational experiences for all children and families in their care. Accountability for outcomes is high, and resources for professional support are limited. Therefore, the early education field needs well-conducted empirical studies on which to base professional development practices. In this article, we offer research directions associated with the processes underlying professional development, including areas in need of investigation that can inform the early childhood education field in terms of how professional development efforts exert their influence and produce meaningful change in practitioners' skills, behaviors, and dispositions. The article highlights representative research from the professional development literature on its various forms/approaches and offers an agenda for research on the professional de...

Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV

Abstract: Many measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The b jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV).