Student Loan Repayment and College Accountability

Summary: Student loan debt and defaults have been steadily rising, igniting public worry about the associated public and private risks. This has led to controversial attempts to curb defaults by holding colleges, particularly those in the for-profit sector, increasingly accountable for the student loan repayment behavior of their students. These efforts attempt to protect taxpayers against the misuse of public money used to encourage college enrollment and to safeguard students against potentially risky human capital investments. Recent policy proposals penalize colleges for students ’ poor repayment performance, raising questions about institutions ’ power to influence this behavior. Extant research does not conclusively establish a causal link between type of college and loan default. Available evidence, moreover, suggests that student demographics and family financial resources are related to default. As a result, policies targeting schools where students default on loans at high rates may disproportionately affect the postsecondary decisions of certain categories of students, such as lowincome, minority, and financially independent students. Policymakers therefore face the challenge of promoting the efficient use of public funds and protecting students while also encouraging access to higher education

Creep Properties of NiAl-1Hf Single Crystals Re-Investigated

NiAl-1Hf single crystals have been shown to be quite strong at 1027 C, with strength levels approaching those of advanced Ni-based superalloys. Initial testing, however, indicated that the properties might not be reproducible. Study of the 1027 C creep behavior of four different NiAl-1Hf single-crystal ingots subjected to several different heat treatments indicated that strength lies in a narrow band. Thus, we concluded that the mechanical properties are reproducible. Recent investigations of the intermetallic NiAl have confirmed that minor alloying additions combined with single-crystal growth technology can produce elevated temperature strength levels approaching those of Ni-based superalloys. For example, General Electric alloy AFN 12 {Ni-48.5(at.%) Al-0.5Hf-1Ti-0.05Ga} has a creep rupture strength equivalent to Rene 80 combined with a approximately 30-percent lower density, a fourfold improvement in thermal conductivity, and the ability to form a self-protective alumina scale in aggressive environments. Although the compositions of strong NiAl single crystals are relatively simple, the microstructures are complex and vary with the heat treatment and with small ingot-toingot variations in the alloy chemistry. In addition, initial testing suggested a strong dependence between microstructure and creep strength. If these observations were true, the ability to utilize NiAl single-crystal rotating components in turbine machinery could be severely limited. To investigate the possible limitations in the creep response of high-strength NiAl single crystals, the NASA Glenn Research Center at Lewis Field initiated an in depth investigation of the effect of heat treatment on the microstructure and subsequent 1027 C creep behavior of [001]-oriented NiAl-1Hf with a nominal chemistry of Ni-47.5Al-1Hf-0.5Si. This alloy was selected since four ingots, grown over a number of years and possessing slightly different compositions, were available for study. Specimens taken from the ingots were subjected to several heat treatment schedules, examined by transmission electron microscopy, and tested in both compression and tension. An example of the microstructure found in a [001]-oriented NiAl-1Hf specimen after a solution treatment at 1317 C for 50 hr followed by air cooling is illustrated in the image on the left, where the NiAl matrix contains a uniform distribution of nanometer-scale Gphase (Ni16Hf6Si7) precipitates. Other heat treating schedules produced microstructures with nanometer-sized G-phase cubes and plates or, in an extreme case, produced a microstructure with all the G-phase converted to Heusler (Ni2AlHf) particles. The results of 1027 C creep strength and strain rate testing are illustrated which summarizes data from tensile and compressive testing of samples cut from all four NiAl-1Hf ingots and subjected to a variety of heat treatment schedules. With one exception, all the strength values lie in a narrow band that spans six orders of magnitude in strain rate. The only factor that produced results outside of this band was the heat treatment schedule that dissolved all the G-phase and replaced it with Heusler precipitates. The results portrayed in this figure lead to the important practical conclusion that the elevated-temperature creep properties of NiAl-1Hf single crystals are reproducible and are not affected by small variations in alloy chemistry from ingot to ingot or by different initial distributions of G-phase in the heat-treated alloy. The only variable in this study that produced a significant and delerious effect on mechanical strength was a post-solution heat treatment that lead to the complete disappearance of the G-phase in favor of Heusler precipitates

Search for materials beyond the capabilities of Ni-based Superalloys: A partial journey

Higher engine efficiency, reduced specific fuel consumption, improved component durability and reliability, reduced noise and reduced life cycle costs are continually desired in turbines used for propulsion and power generation. Engine components are subjected to very high temperatures, stresses, and oxidizing, corrosive and erosive environments. To meet these demands, materials beyond the capabilities of Ni-base superalloys are being sought. In addition to higher strength, ductility, fracture toughness, impact resistance, reduced density, improved environmental resistance and better coating compatibility are being emphasized. Manufacturability and lower cycle cost are also key requirements. Unfortunately, an acceptable balance in mechanical, physical and environmental properties has been difficult to achieve. Specific design requirements for production and newer versions of turbines will be outlined. Several design concepts and studies on turbine blades will be presented to emphasize the role of alloy density in not only reducing the weight and stresses in the blades, but also other associated components such as turbine disk. Various material systems under development will be compared and discussed including current development strategies, activities and progress. Challenges and case studies will be presented. The presentation will also present a futuristic vision for new turbine materials

"He's on fire for justice!": Using critical conversations to explore sociopolitical topics in elementary classrooms

Despite the dominant discourse that childhood is a time of innocence, elementary students (kindergarten through fifth grade) notice the world around them, witness and experience injustice and deserve to explore “controversial issues” in their classrooms. This article introduces readers to Olivia and her second grade students. Olivia wanted to create what she called a “social justice classroom” and made intentional curricular moves in order to bring this vision to life. Primarily, she implemented “social justice read aloud time” and read and discussed thoughtfully chosen trade books on “controversial issues” every Friday afternoon. Students were highly engaged in these read alouds and developed understandings and insights well beyond academic content standards. Olivia’s approach to teaching aligned with critical literacy, a pedagogical framework that values multiple perspectives, brings sociopolitical topics into the classroom, disrupts the status quo, and moves toward social action and  the Inquiry Design Model of social studies education. Using this interdisciplinary lens, empirical examples of the purposeful exploration of “controversial issues” in a second grade classroom are discussed. Through Olivia’s voice, along with the voices of her students, description of the learning that happened in this social justice classroom is offered as evidence that teaching controversial issues in elementary classrooms has repercussions far beyond school walls. Implications for both practicing teachers and teacher educators are discussed

Oxygen impurities in NiAl: Relaxation effects

We have used a full-potential linear muffin-tin orbital method to calculate the effects of oxygen impurities on the electronic structure of NiAl. Using the supercell method with a 16-atom supercell we have investigated the cases where an oxygen atom is substitutionally placed at either a nickel or an aluminum site. Full relaxation of the atoms within the supercell was allowed. We found that oxygen prefers to occupy a nickel site over an aluminum site with a site selection energy of 138 mRy (21,370 K). An oxygen atom placed at an aluminum site is found to cause a substantial relaxation of its nickel neighbors away from it. In contrast, this steric repulsion is hardly present when the oxygen atom occupies the nickel site and is surrounded by aluminum neighbors. We comment on the possible relation of this effect to the pesting degradation phenomenon (essentially spontaneous disintegration in air) in nickel aluminides.Comment: To appear in Phys. Rev. B (Aug. 15, 2001

Feasibility of SiC composite structures for 1644 deg gas turbine seal applications

The feasibility of silicon carbide composite structures was evaluated for 1644 K gas turbine seal applications. The silicon carbide composites evaluated consisted of Si/SiC Silcomp (Trademark) - and sintered silicon carbide as substrates, both with attached surface layers containing BN as an additive. A total of twenty-eight candidates with variations in substrate type and density, and layer chemistry, density, microstructure, and thickness were evaluated for abradability, cold particle erosion resistance, static oxidation resistance, ballistic impact resistance, and fabricability. The BN-free layers with variations in density and pore size were later added for evaluation. The most promising candidates were evaluated for Mach 1.0 gas oxidation/erosion resistance from 1477 K to 1644 K. The as-fabricated rub layers did not perform satisfactorily in the gas oxidation/erosion tests. However, preoxidation was found to be beneficial in improving the hot gas erosion resistance. Overall, the laboratory and rig test evaluations show that material properties are suitable for 1477 K gas turbine seal applications

The Economics of Parenting, Self-Esteem, and Academic Performance: Theory and a Test

This paper develops a theory about how signals sent to a child by an altruistic parent affect a child\u27s self-esteem, effort and long-term performance when a parent has better information about child ability than children do themselves. We carry out OLS, 2SLS, and 3SLS estimations of our model on a sample of 651 college students. Our results show some complementary actions before college, such as parental praise, foster academic achievement above what natural ability would predict. Conversely, we find some substitutionary actions before college, such as providing them cars as gifts, are associated with lower effort in college and underachievement.

Will the Big Five Personality Factor Stand-up: An Analysis of NEO Personality Inventory-Revised

The aim of the present study was to examine the factorial invariance of a major instrument i.e., NEO-Personality Inventory-Revised-Form S (NEO PI-R)1, tapping broad five factor of personality such as: neuroticism, extraversion, openness to experiences, agreeableness, and conscientiousness. It also aimed to study the replication of broad five factors in Indian population. To achieve these objectives, the NEO PI-R was administered on a sample of 375 subjects (age range from 18 yrs to 22 yrs) randomly selected from various academic institutes in Indian. The statistical analysis such as descriptive statistics, reliability analysis, and factor analysis were performed on collected data. The higher mean score on neuroticism in present data indicates a cultural variation across the country. Reliability analysis was confirmed test-retest reliability ranging from 0.70 to 0.78 (n = 108, gap of over 60 days) and strikingly high internal consistency ranging from 0.98 to 0.99 for the big five factor in India. Bivariate correlation analyses demonstrate positive significant correlations among the facets scale of NEO-PI-R and their corresponding factor except few correlations. The significant correlations among the five factors question their independence in the measurement of personality structure. In factor analysis, the three personality dimension such as conscientiousness, neuroticism, and agreeableness were clearly replicates and the other two factors such as extraversion and openness to experience were partially replicate to define the personality structure in Indian population. These findings are in line with existing literature and have strong implications to define the personality structure in Indian populatio

Pedagogical becoming : one teacher's journey toward social justice teaching in an early childhood classroom /

This dissertation followed the journey of a second grade teacher as she strove to create what she called a "social justice atmosphere" in her classroom. The teacher's pedagogical approach is situated within the literature on critical literacy, as she worked to interrupt the status quo, value multiple perspectives, and promote social action through the class read alouds on sociopolitical issues. In order to thoroughly depict her teaching processes, decisions, and roadblocks, a Foucauldian lens is used to track the micropractices of power swirling around her. Insights include a glimpse into the challenges of teaching using a critical literacy framework in early childhood settings, implications for teacher education programs and in-service professional development, and the affordances of using a post-structural lens in studies of critical literacy.Dr. Candace Kuby, Dissertation Supervisor.Includes bibliographical references (pages 164-173)