Effects of Ionizing Radiation on Solid Rocket Motor Components

Problems which the solid propellant rocket engineer will encounter in designing for long-term storage in a radiation environment are discussed. A summary of present knowledge of the radiation environment is given. Mechanisms of radiation degradation and its effects on tensile properties of propellant binders are discussed qualitatively. Data from a program of irradiation of several propellants is presented. Properties of two of the propellants were changed significantly by doses of the order of 4 x 10(exp 6) rads

It’s Really About Sex: Same-Sex Marriage, Lesbigay Parenting, and the Psychology of Disgust

The effects of gay and lesbian parenting on children has been the touchstone issue in much of the recent state litigation on same sex marriage, with opponents of same sex marriage arguing that there is a rational basis for denying marriage rights to gays and lesbians because the central purpose of marriage is procreation and childrearing, but that children are harmed or disadvantaged when raised by gay or lesbian parents. To interrogate this claim, I critique the social science research that informs the concerns frequently expressed about the possible negative effects of lesbigay parenting on children\u27s emotional, psychosocial, and sexual development. In particular, I focus on research relevant to whether growing up in a lesbigay household is as positive an experience for children as growing up in a heterosexual household, as much of the literature to date has addressed the issue of whether lesbigay parenting is harmful to children. I conclude that the research fails to support the theory that denying marriage or parenting rights to same sex couples serves the welfare of children. I further argue that public opposition to gay marriage, particularly in the context of lesbigay parenting, is animated by a deeper concern - the proverbial “elephant in the room” on gay rights issues. That elephant is the visceral disgust reaction that many Americans feel toward homosexual sex, and the resulting moral intuition that homosexuality and homosexual relationships are immoral. Thus, many people will conclude that it is better for children to be raised in heterosexual households because they do not want children exposed to the lesbigay “lifestyle.” Nor do they want to increase the “risk” that children will develop a homosexual orientation if they are raised by lesbigay parents. The article discusses new psychological research on moral decision making, which suggests that the “moral” emotion of disgust is at the root of much of the opposition to gay rights. The disgust reaction is likely a byproduct of human evolution that fails to inform rational judgments about the policy questions surrounding lesbigay parenting and marriage rights

Space groups P1 and Cc: how are they doing?

A survey of recent entries in the Cambridge Structural Database suggests that the percentage of structures described in space groups of inappropriately low symmetry has decreased from about 10% in the early 2000s to less than 5% today for space group Cc, but that for space group P1 it remains close to 8%