Atomization and mixing study

The state of the art in atomization and mixing for triplet, pentad, and coaxial injectors is described. Injectors that are applicable for LOX/hydrocarbon propellants and main chamber and fuel rich preburner/gas generator mixture ratios are of special interest. Various applicable correlating equations and parameters as well as test data found in the literature are presented. The validity, utility, and important aspects of these data and correlations are discussed and the measurement techniques used are evaluated. Propellant mixing tests performed are described and summarized, results are reported, and tentative conclusions are included

Three Essays on the Economics of Changing Behavior With Costly Policy Instruments.

Attempts to influence individual behavior with public policy are numerous and diverse. The analysis of Pigouvian taxation famously proves that each behavior to be controlled can be analyzed and the optimal policy determined without reference to other behaviors. This result is predicated on the policy instrument, a tax, being a costless transfer from the private individual to the government. The private loss in taxes paid are exactly offset by the public gain of tax receipts. Actual policies used to control behavior, including taxation, do incur administrative costs. In the notable case of incarceration, the policy collects none of the private losses in the form of tax revenue. When policy instruments are costly, the optimal policy to influence each behavior must account for the effects on all other behaviors. This dissertation defines the optimal Pigouvian taxes when there are multiple activities which cause externalities and administration of the tax system is costly. A number of restrictions on the tax system and resulting welfare implications are discussed. An analysis of the criminal justice system suggests that punishments for one crime should be related to the change in the crime rate for each other crime, weighted by the harm caused by each instance of those crimes. A new definition for deterrence and incapacitation is offered, which bears on the relationships among crimes as well as defining the empirical test for whether criminal behavior is rational, in that it can be represented by complete, transitive and reflexive preferences over activities.PhDEconomicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113603/1/danjaqua_1.pd

The Case for Subsidizing Harm: Constrained and Costly Pigouvian Taxation with Multiple Externalities

Many activities are subsidized despite generating negative externalities. Examples include needle exchanges and energy production subsidies. We explain this phenomenon by developing a model in which the policymaker faces constraints or costs. We highlight three examples. First, it may be optimal to subsidize a harmful activity if the policymaker cannot set the first-best tax on an externally harmful substitute. Second, it may be optimal to subsidize a harmful production process if the activity mix at lower levels of output uses more harmful activities than the activity mix at higher levels of output. Third, it may be optimal to subsidize a harmful activity if there is a large administrative cost associated with taxing a harmful substitute. We also show how the functional form of the cost of administering a Pigouvian tax affects the optimal tax. When administrative cost is a function of only tax rates, the policymaker should tax each activity. However, an increase in the tax presents a tradeoff: lower externality, but higher administrative cost. A subsidy may be optimal for some externally harmful activities. When administrative cost is a function of only activity levels, it may not be optimal to tax every activity. If it is optimal to tax all of the activities, the policymaker should set the tax equal to the externality plus the marginal administrative cost. If it is not optimal to tax every activity, the complementarity between activities comes into play and it may be optimal to subsidize externally harmful activities

Fine Structure and Organ Culture of Chick Embryo Dorsal Aorta

Embryonic blood vessels have not been grown in organ culture, in a way which might easily submit them to studies of vascular organogenesis. The chick embryo dorsal aorta is easily accessible and relatively simple to explant to culture. Its organ culture may provide a model for wounding and repair of the intima and/or media and provide a model for studies of growth (or maintenance) and differentiation. Fresh dorsal aorta and its organ culture from the chick embryo was characterized morphologically by light microscopy scanning (SEM) and transmission electron microscopy (TEM) from days 4 to 18. Explants were incubated up to 4 days at 37.5°C in normal atmosphere in media including whole chick embryo extract (EE) diluted to 20%. The normal fine structure by SEM shows that as the embryo ages the endothelial cells of the aorta tend to elongate, their microvilli lengthen and increase in size and number up to about 11 days, after which they decrease. TEM also demonstrates an increased differentiation of smooth muscle cells as embryonic age advances. The best culture medium was EE20-Tyrode\u27s. Most of the explants from 14 and 17 days cultured in EE20-Tyrode\u27s contracted into small balls of tissue, endothelial side out. None of these explants showed any significant cellular degeneration. None of the explants survived in EE20-DMEM. Addition of insulin to each medium had no effect on the explants. Intimal cells resembling myofibroblasts were observed in the contracted explants. Using a simple culture condition the chick embryo dorsal aorta can be sustained in organ culture for at least 4 days. The most suitable age for organ culture studies is 9 days (or perhaps somewhat younger); however, it is the most difficult to obtain

Femininity Unveiled: Perspectives on the Protagonists of Medea and Trachiniae

Why are two such controversial characters as Medea and Deianeira the protagonists in two plays in ancient Greek tragedy? This thesis analyzes the staging, actions, and speeches of these two women. It takes a closer look at expressions of femininity in each play. I argue that Medea and Trachiniae through a variety of expressions suggest that the audience take on an expanded understanding of femininity. The female protagonists of these two plays, despite their shocking actions, are neither condemned nor condoned for those actions. These female characters are presented as complex and fully human. They find themselves facing impossible dilemmas, and they cannot be confined to socially prescribed roles and behaviors for ancient Greek women

Treatment of the Intrinsic Hamiltonian in Particle-Number Nonconserving Theories

We discuss the implications of using an intrinsic Hamiltonian in theories without particle-number conservation, e.g., the Hartree-Fock-Bogoliubov approximation, where the Hamiltonian's particle-number dependence leads to discrepancies if one naively replaces the particle-number operator by its expectation value. We develop a systematic expansion that fixes this problem and leads to an a posteriori justification of the widely-used one- plus two-body form of the intrinsic kinetic energy in nuclear self-consistent field methods. The expansion's convergence properties as well as its practical applications are discussed for several sample nuclei.Comment: 6 pages, 5 figure

Intrauterine Infection With Coxsackievirus: Is it a Cause of Congenital Cardiac Malformations?

Background: Although maternal infections with coxsackievirus during pregnancy are relatively common, fetal infections are quite rare. Coxsackievirus infection in utero has been associated with myocarditis, but has not been proven a teratogen

Exercise-Induced Anaphylaxis: A Case Report and Review of the Diagnosis and Treatment of a Rare but Potentially Life-Threatening Syndrome

A 24-year-old male Marine with an uncomplicated medical history and a long history of strenuous, daily exercise presented to the emergency department after experiencing anaphylactic shock while running. Symptoms resolved following administration of intramuscular diphenhydramine, ranitidine, intravenous methylprednisolone, and intravenous fluids. On followup in the allergy clinic, a meticulous clinical history was obtained which elucidated a picture consistent with exercise-induced anaphylaxis. He had experienced diffuse pruritus and urticaria while exercising on multiple occasions over the last three years. His symptoms would usually increase as exercise continued. Prior to the first episode, he regularly exercised without symptoms. Exercise-induced anaphylaxis is a rare but potentially life-threatening syndrome that requires a careful clinical history and is a diagnosis of exclusion. Treatment is primarily exercise avoidance. Prophylactic mediations are inconsistently effective but are empirically used. Successful treatment with omalizumab was recently reported in a case of refractory exercise-induced anaphylaxis

Exact Solutions of Model Hamiltonian Problems with Effective Interactions

We demonstrate with soluble models how to employ the effective Hamiltonian approach of Lee and Suzuki to obtain all the exact eigenvalues of the full Hamiltonian. We propose a new iteration scheme to obtain the effective Hamiltonian and demonstrate its convergence properties.Comment: 12 pages and 1 figur

Large-basis shell-model calculations for p-shell nuclei

Results of large-basis shell-model calculations for nuclei with A=7-11 are presented. The effective interactions used in the study were derived microscopically from the Reid93 potential and take into account the Coulomb potential as well as the charge dependence of T=1 partial waves. For A=7, a $6\hbar\Omega$ model space was used, while for the rest of the studied nuclides, the calculations were performed in a $4\hbar\Omega$ model space. It is demonstrated that the shell model combined with microscopic effective interactions derived from modern nucleon-nucleon potentials is capable of providing good agreement with the experimental properties of the ground state as well as with those of the low-lying excited states.Comment: 17 pages. REVTEX. 16 PostScript figure