Environmental stability graphite/PMR-15 composites

During the past few years the Boeing Company was screening graphite composites for use in hot areas of engine nacelle structure. Structural and thermal analyses have shown that there is the potential for a 25 to 30 percent weight savings by using a graphite polyimide (Gr/PI) composite material in this type of structure. Work conducted on the NASA CASTS program (Composites for Advanced Space Transportation Systems) amply demonstrated the capability of Graphite/PMR-15 for short term service (125 hours) at temperatures up to 589 K (600 F). In addition, the CASTS program demonstrated that large structures could be fabricated using Gr/PMR-15. In commercial applications, however, the requirement exists for long term service capability (tens of thousands of hours) at temperatures ranging upwards from 449 K (350 F). The results of Graphite/PMR-15 materials characterization efforts conducted at Boeing are presented with emphasis on materials properties after isothermal aging at temperatures of 449 K (350 F) and above

Perceptions of time in relation to climate change

Time is at the heart of understanding climate change, from the perspective of both natural and social scientists. This article selectively reviews research on time perception and temporal aspects of decision making in sociology and psychology. First we briefly describe the temporal dimensions that characterize the issue of climate change. Second, we review relevant theoretical approaches and empirical findings. Then we propose an integration of these insights for the problem of climate change and discuss mismatches between the human mind, surrounding social dynamics, and climate change. Finally, we discuss the implications of this article for understanding and responding to climate change, and make suggestions on how we can use the strengths of the human mind and social dynamics to communicate climate change in its temporal context.This article is categorized under: Climate, History, Society, Culture &gt; Ideas and Knowledge Perceptions, Behavior, and Communication of Climate Change &gt; Perceptions of Climate Change </jats:p

The Effect of Medicaid Expansions for Low-Income Children on Medicaid Participation and Private Insurance Coverage : Evidence from the SIPP

We examine Medicaid enrollment and private coverage loss following expansions of Medicaid eligibility. We attempt to replicate Cutler and GruberÂ’s (1996) results using the Survey of Income and Program Participation, and find smaller rates of take-up and little evidence of crowding out. We find that some of the difference in results can be attributed to different samples and recall periods in the data sets used. Extending the previous literature, we find that take-up is slightly increased if a childÂ’s siblings are eligible and with time spent eligible. Focusing on children whose eligibility status changes during the sample, we estimate smaller take-up effects. We find little evidence of crowding out in any of our extensions.

The Effect of Medicaid Expansions for Low-Income Children on Medicaid Participation and Insurance Coverage: Evidence from the SIPP

Increased availability of public health insurance for children has led to two potentially contradictory concerns for public policy: that expanded availability of public insurance may lead families to decline private insurance and that additional public coverage may not reach many uninsured children. We examine these two concerns using data from the 1987-1993 Surveys of Income and Program Participation. Using static models we find that the expansions resulted in increased Medicaid coverage, although the estimates of take-up are smaller than estimates from previous research. We find little evidence of a negative relationship of any significant magnitude between eligibility for Medicaid and private coverage. We also find that children who have been eligible for Medicaid longer are more likely to be enrolled in Medicaid but no more likely to have lost private coverage. Including individual fixed effects reduces the magnitude of the estimated take-up effect, while the fixed effects estimates for the private insurance regression become negative and marginally statistically significant in some specifications. Simple dynamic models of insurance choice show that insurance choice is quite persistent. The estimated long run impact of eligibility in the dynamic models is larger than the estimate from the static models, while the immediate impact of expanded Medicaid eligibility from the dynamic models is smaller than the estimated effect from the static models.

Estimating Heterogeneous Take-up and Crowd-Out Responses to Marginal and Non-Marginal Medicaid Expansions

We use a linear probability model with interactions and a switching probit model (SPM) to estimate heterogeneous effects of Medicaid expansions on Medicaid take-up, private insurance coverage and crowd-out. Specifically, we estimate: i) LATEs; ii) ATETs for the currently eligible; and iii) ATETs for those made eligible by a non-marginal (counterfactual) expansion in Medicaid eligibility. Both estimation methods can control for observable differences across individuals, while SPM can also control for unobservable differences. For Medicaid take-up and private insurance coverage, the effects are precisely estimated and differ dramatically across demographic groups, but this is less true for the crowd-out estimates.Medicaid expansions, take-up, crowd-out, treatment effects, switching probit model, linear probability model with interactions, counterfactual policy analysis

Community Property—Statutory Agreement for Disposition at Death—Termination

Recently adopted Initiative 2081 has evoked no small amount of comment, much of which centers about the problems of uncertainty, utility, and questioned reception and treatment by the courts. Although passed with the stated aim of eliminating probate expenses, the uncertainty of the Initiative may well occasion, in the individual case, as much or more litigation expense than probate ever would. This consideration, where survivorship is the end sought, may well lead to increased use of the relatively more certain community property agreement. Because of this possibility of increased use, and because In re Wittman emphasizes the manner in which community property agreements may be terminated, a few brief comments on this recent case are deemed to be merited