Propellant variability assessment

Efforts to determine whether rocket propellant density and modulus can be reliably measured using non-destructive ultrasonic techniques are reported. The objective was not achieved, primarily due to the approach taken

Thomson scattering above solar active regions and an ad-hoc polarization correction method for the emissive corona

Thomson scattered photospheric light is the dominant constituent of the lower solar corona's spectral continuum viewed off-limb at optical wavelengths. Known as the K-corona, it is also linearly polarized. We investigate the possibility of using the a priori polarized characteristics of the K-corona, together with polarized emission lines, to measure and correct instrument-induced polarized crosstalk. First, we derive the Stokes parameters of Thomson scattering of unpolarized light in an irreducible spherical tensor formalism. This allows forward synthesis of the Thomson scattered signal for the more complex scenario of symmetry-breaking features in the incident radiation field, which could limit the accuracy of our proposed technique. For this, we make use of an advanced 3D radiative magnetohydrodynamic coronal model. Together with synthesized polarized signals in the Fe XIII 10746 Angstrom emission line, we find that an ad hoc correction of telescope and instrument-induced polarization crosstalk is possible under the assumption of a non-depolarizing optical system.Comment: Accepted for publication in Ap

Charting a Future Course for Development: Natural Resources, Conservation, and Community Character in Coastal Alaska

Dramatic social changes are occurring across rural America as traditional natural resource-based industries such as fishing and forestry decline, and amenity-driven development attracts new residents and visitors. These changes are altering not only the economies and cultural identities of rural communities, but also entire regions where seemingly similar towns respond to these social and economic shifts in distinct ways. Using survey data from 1,541 residents of Southeast Alaska, we examine individual views regarding the role of fishing, forestry, and tourism in this region’s economic future. We also assess beliefs about the importance of conserving natural resources and the preservation of the area’s cultural character within new development efforts. Findings show that social factors such as age, education, political party affiliation, and individuals’ economic well-being, along with place of residence explain diverging views. Given the changing demographics and the shifting interconnections between different communities within rural regions, these results illustrate the importance of designing investigations that capture broad regional trends while also highlighting the key place-specific factors that shape beliefs about natural resource-related industries and the priorities for future rural development activities

Materials characterization on efforts for ablative materials

Experimental efforts to develop a new procedure to measure char depth in carbon phenolic nozzle material are described. Using a Shor Type D Durometer, hardness profiles were mapped across post fired sample blocks and specimens from a fired rocket nozzle. Linear regression was used to estimate the char depth. Results are compared to those obtained from computed tomography in a comparative experiment. There was no significant difference in the depth estimates obtained by the two methods

A Model-based Technique for Ad Hoc Correction of Instrumental Polarization in Solar Spectropolarimetry

We present a new approach for correcting instrumental polarization by modeling the non-depolarizing effects of a complex series of optical elements to determine physically realizable Mueller matrices. Provided that the Mueller matrix of the optical system can be decomposed into a general elliptical diattenuator and general elliptical retarder, it is possible to model the cross-talk between both the polarized and unpolarized states of the Stokes vector and then use the acquired science observations to determine the best-fit free parameters. Here, we implement a minimization for solar spectropolarimetric measurements containing photospheric spectral lines sensitive to the Zeeman effect using physical constraints provided by polarized line and continuum formation. This model-based approach is able to provide an accurate correction even in the presence of large amounts of polarization cross-talk and conserves the physically meaningful magnitude of the Stokes vector, a significant improvement over previous ad hoc techniques.Comment: 16 pages, 4 figures, Accepted for publication in Ap

The Impact of Family-Based Interventions on Adolescent Glycemic Control: A Systematic Review of the Literature

poster abstractObjective: Glycemic control is a major source of family conflict among adolescents with type 1 diabetes and their parents. Family conflict is a determinant of how well adolescents will maintain glycemic control throughout adolescence; thus, family conflict resolution is a crucial step to managing their diagnosis. The purpose of this systematic review is to evaluate the effectiveness of family-based interventions on glycemic control of adolescents with type 1 diabetes. Methods: Databases utilized were Medline Ovid, PsycINFO, and Web of Science. Inclusion criteria for the studies selected included: peer-reviewed studies conducted in the United States; published between January 1994 to December 2014; and evaluated a family-based intervention’s effectiveness on adolescent diabetic glycemic control. Results: 11 studies met the criteria. Methods used to resolve family conflict included teamwork interventions, tailored interventions, behavioral family systems therapy, and family problem-solving management. Six studies did not show any significant influence on glycemic control. The only significant results on lowering glycemic control were found when a12-month follow-up was completed. Behavioral family systems therapy and family problem-solving management were found to be significant in improving adolescent glycemic control. Conclusion: It is crucial for healthcare providers to be aware of effective family-based interventions to help resolve family conflict and promote healthy glycemic control among adolescents with type 1 diabetes. Interventions specifically designed to address family conflict will not only foster healthy family relationships, but will target adolescents struggling to maintain adequate glycemic control. Results from this review shows that interventions based on family systems therapy and problem-solving management seem to be most effective. Future research is needed to replicate these findings in larger, more diverse samples