Student Loans and Health-related Financial Hardship

Research has shown that student loan borrowers in repayment exhibit physical and mental health problems. These can be exacerbated by and contribute to health-related financial hardship. We use the 2015 U.S. National Financial Capability Study to examine the likelihood of having past due medical bills and of avoiding health care services by not purchasing prescribed medication, skipping tests or follow-up with a doctor or not seeking care for a medical problem. Borrowers on income-driven repayment plans and those who made late payments are found to be more likely to have unpaid medical bills and to have avoided required medical attention. In addition, those who completed their funded education program but had made a late payment were more likely to avoid seeking medical attention when needed. Practical implications for loan administrators and those working with students are discussed

Flexural behavior of steel fiber reinforced concrete: testing and modelling

In this paper the results of tests performed on specimens and structural elements made of steel fiber reinforced concrete are presented. Fiber content ranged from 0 to 60 kg/m3 of concrete. Using the results of the uniaxial compression tests performed under displacement control condition, a stress strain relationship for fiber concrete in compression was derived. Three point bending tests on notched beams were carried out in order to simulate the post cracking behavior and to evaluate the fracture energy. Based on the constitutive relationships derived from the experiments, a layered model for the analysis of steel fiber reinforced concrete cross sections was developed. The model performance and the benefits of fiber reinforcement on thin slabs reinforced with steel bars were assessed by carrying out tests on slab strips. The main results are presented and discussed

Fracture Toughness Prediction for MWCNT Reinforced Ceramics

This report describes the development of a micromechanics model to predict fracture toughness of multiwall carbon nanotube (MWCNT) reinforced ceramic composites to guide future experimental work for this project. The modeling work described in this report includes (i) prediction of elastic properties, (ii) development of a mechanistic damage model accounting for matrix cracking to predict the composite nonlinear stress/strain response to tensile loading to failure, and (iii) application of this damage model in a modified boundary layer (MBL) analysis using ABAQUS to predict fracture toughness and crack resistance behavior (R-curves) for ceramic materials containing MWCNTs at various volume fractions

The effects of an aggressive environment on the subcritical crack growth of a continuous-fiber ceramic composite

Time-dependent crack growth measurements of ceramic composites in aggressive environments are being conducted on materials consisting of CVI SiC reinforced with Nicalon fibers (SiC/SiC{sub f}) having C and BN fiber-matrix interfaces. Crack velocities are determined as a function of applied stress intensity. Results have been obtained for crack velocity-stress intensity relationships in pure Ar and in Ar plus 2000 ppM O{sub 2} atmospheres at 1100{degrees}C. A 2D micromechanics model is used to represent the time-dependence of observed crack bridging events and is able to rationalize the observed phenomena

Prognostics Health Management for Advanced Small Modular Reactor Passive Components

In the United States, sustainable nuclear power to promote energy security is a key national energy priority. Advanced small modular reactors (AdvSMR), which are based on modularization of advanced reactor concepts using nonlight- water reactor (LWR) coolants such as liquid metal, helium, or molten salt, may provide a longer-term alternative to more conventional LWR-based concepts. The economics of AdvSMRs will be impacted by the reduced economy-of-scale savings when compared to traditional LWRs and the controllable day-to-day costs of AdvSMRs are expected to be dominated by operations and maintenance costs. Therefore, achieving the full benefits of AdvSMR deployment requires a new paradigm for plant design and management. In this context, prognostic health management of passive components in AdvSMRs can play a key role in enabling the economic deployment of AdvSMRs. This paper discusses features of AdvSMR systems that are likely to influence PHM implementation for passive components and discusses some requirements based on those features. Further, a brief overview of the state-ofthe- art in PHM relevant to AdvSMR passive components is provided followed by an illustration of prognostics for passive AdvSMR components

Characterization of U-Mo Foils for AFIP-7

Twelve AFIP in-process foil samples, fabricated by either Y-12 or LANL, were shipped from LANL to PNNL for potential characterization using optical and scanning electron microscopy techniques. Of these twelve, nine different conditions were examined to one degree or another using both techniques. For this report a complete description of the results are provided for one archive foil from each source of material, and one unirradiated piece of a foil of each source that was irradiated in the Advanced Test Reactor. Additional data from two other LANL conditions are summarized in very brief form in an appendix. The characterization revealed that all four characterized conditions contained a cold worked microstructure to different degrees. The Y-12 foils exhibited a higher degree of cold working compared to the LANL foils, as evidenced by the highly elongated and obscure U-Mo grain structure present in each foil. The longitudinal orientations for both of the Y-12 foils possesses a highly laminar appearance with such a distorted grain structure that it was very difficult to even offer a range of grain sizes. The U-Mo grain structure of the LANL foils, by comparison, consisted of a more easily discernible grain structure with a mix of equiaxed and elongated grains. Both materials have an inhomogenous grain structure in that all of the characterized foils possess abnormally coarse grains

Communication: First-Principles Evaluation of Alkali Ion Adsorption and Ion Exchange in Pure Silica Lta Zeolite (Vol 149, 131102, 2018)

Using first-principles calculations, we studied the adsorption of alkali ions in pure silica Linde Type A (LTA) zeolite. The probability of adsorbing alkali ions from solution and the driving force for ion exchange between Na+ and other alkali ions at the different adsorption sites were analyzed. From the calculated ion exchange isotherms, we show that it is possible to exchange Na+ with K+ and Rb+ in water, but that is not the case for systems in a vacuum. We also demonstrate that a solvation model should be used for the accurate representation of ion exchange in an LTA and that dispersion interactions should be introduced with care

Composite Synthesis Methodology Development: Nanocrvstalline SiC and Ti3SiC2 Alloys for Reactory Materials – Outline of initial synthesis capabilities M4CT-13PN0405034

We have identified three initial preceramic polymers to help produce the SiC-based alloys for this project and have developed simple processing steps to make SiC-based alloy ceramics. The use of unfilled SMP-10 (Polycarbosilane) or SMP-877 (Methyl-Polycarbosilane) is not feasible due to the large mass losses that occur during pyrolysis. The pre-gelling steps below save time when those two polymers are filled with powders. The use of SL-MS30 provides us with a SiC-filled polymer that can be used to test out the CNT mats without further complications due to other powders