Apparatus and method for generating large mass flow of high temperature air at hypersonic speeds

A description is given of tests performed in the Mach number 8 to 10 regime to generate high temperature air at hypersonic speeds. The test flow was obtained by pressuring a ceramic lined storage tank with air to a pressure of about 100 to 200 atm. The air is heated to temperatures of 7,000 R to 8,000 R prior to introduction into the tank by passing air through an electric arc heater. The air cools to 5,500 R to 6,000 R while in the tank and then it is rapidly released through a Mach number 8 to 10 nozzle. Cold air or hot driver gas under pressure is injected simultaneously with the release of pressurized hot air and regulated to enter the tank at the same rate the hot air is leaving. This holds pressure in the tank constant during the test. Alternatively, the driver gas is introduced into the tank prior to the discharge of the hot air to increase the pressure in the tank and permit tests at higher pressures than can be handled by the arc heater

Leadership for Transforming High Schools

Explores the unique tasks and challenges faced by education leaders in the face of stricter accountability reforms associated with the federal No Child Left Behind legislation and associated state-level education policy initiatives

Solid-state growth of Si to produce planar surfaces

Paralleling the sophisticated control of Si and GaAs growth from fluid media, we demonstrate control of Si growth using a solid growth medium. Faceted dissolution pits were first produced in a Si substrate using standard photolithographic techniques and Al metallization. Si was then evaporated onto the cold structure, depositing as amorphous material. Upon heating, the amorphous Si migrated through the solid Al and grew rapidly in the faceted pits, typically refilling them flush with the surrounding substrate. Evidence that the rapid growth occurs only while the amorphous Si is dissolving into the Al is presented

Quel avenir pour la gestion des parties prenantes?

articleAu cours des dernières années, le concept de parties prenantes (stakeholders) est, sans aucun doute, l’une des contributions les plus importantes au domaine de l’éthique des affaires. Ce concept exprime un impératif moral en vertu duquel les gestionnaires se doivent de considérer les intérêts de l’ensemble des parties prenantes. Dans sa forme la plus généralement admise, la liste des parties prenantes comprend les employés, les clients, les fournisseurs et la communauté, de même que les actionnaires et les autres investisseurs. Les défenseurs de la gestion des parties prenantes ont raison sur un point : la société à but lucratif moderne doit servir les intérêts de tous les groupes de parties prenantes. Mais là où la gestion des parties prenantes échoue, c’est dans le fait de ne pas reconnaître que des gestionnaires qui agissent dans l’intérêt des actionnaires peuvent aussi,par le fait même,agir dans l'intérêt de tous les groupes de parties prenantes. En effet, dans la mesure où le marché est capable de fournir les bénéfices désirés aux différents groupes de parties prenantes, les gestionnaires n’ont pas explicitement besoin de considérer leurs intérêts lorsqu'ils prennent une décision.Néanmoins,les partisans de la théorie de la gestion des parties prenantes ont raison de rappeler que chacun de ces groupes devraient pouvoir bénéficier des activités de l’entreprise. Ils ont également raison de chercher à rendre les gestionnaires attentifs à leurs responsabilités de créer de la richesse au bénéfice de tous.The concept of stakeholders is, without any doubt, one of the most important contributions to the field of business ethics in the recent years. This concept articulates a moral requirement in virtue of which managers must consider the interests of all stakeholders. In its most common form, the list of stakeholders includes the employees, the customers, the suppliers and the community, as well as shareholders and other investors.The defenders of the stakeholders management theory are right on one point: the modern lucrative business must serve the interests of all stake-holding groups. But the stakeholders management theory fails in not recognizing that managers acting in the interest of the shareholders also can, by the same token, act in the interests of all stakeholders. Indeed, insofar as the market is able to provide the benefits wished by the various stakeholders,the managers do not explicitly need to consider their interests when they make a decision.Nevertheless,partisans of the stakeholders management theory are right to prompt that each one of these groups should be able to profit from the activities of the company. They are also right to recall the responsibilities of managers in creating wealth for the benefit of all

Financial Accounting Topics: Cases and Analysis

This thesis consists of twelve individual case studies that analyze issues and topics related to the current financial accounting landscape. These cases take a practical and professional look at financial accounting the real current world, using technical understanding that has been gained throughout the coursework of the Bachelors of Accountancy major as well as professional skepticism and judgement to assess the situations. All of these cases were facilitated by the Patterson School of Accountancy over a year long period. These cases pertain to recent accounting changes such as pensions, the financial implications of recent scandals such as the BP oil spill, and recent evolutions in the climate of financial accounting such as advancements in technology due to data analytics tools. Research tools and data were partially provided in some cases whereas others required outside sources and research

Steering Contexts for Autonomous Agents Using Synthetic Data

Data-driven techniques have become synonymous with replication of real-world phenomena. Efforts have been underway to use these techniques in crowd simulation through a mapping of pedestrian trajectories onto virtual agents using a similarity of circumstance. These works have exposed two fundamental issues with data-driven crowds. First, robust real-world data is logistically difficult to accurately collect and filled with unknown variables, such as a person\u27s mental state, which change behavior without providing a means to replicate their effects. Second, current data-driven approaches store and search the entire set of training data to decide the next course of action for each agent. A straightforward single-model system would alleviate the burden of storing and searching the data. The problem with a monolithic model, though, is that a single steering policy cannot handle all possible scenarios. To counter this we propose the splitting of possible scenarios into separable contexts, with each context in turn learning a model. The model used by an agent can then be dynamically swapped at runtime based on the evolving conditions around the agent. This results in a more scalable approach to data-driven simulation. In lieu of tracked data from real pedestrians, we propose the use of an oracle steering algorithm. This algorithm stands in for real data and can be queried for a steering decision for any combination of factors. This allows us to more thoroughly explore the problem space as needed. Furthermore, we can control all variables and capture behavior from scenarios that are otherwise infeasible to adequately sample in reality. This synthetic source of training data allows for a scalable and structured approach to training machine-learned models which virtual agents can use to navigate at runtime

American Dreamer: First-Time Homeownership and the Affective Geographies of Dwelling

This research examines the experiences novice homebuyers in New York City and Oakland, CA have during the home search and decision-making processes. Using a mixed-method approach that combines ethnography with critical discourse analysis and non-representational theory, this work examines the ideology of homeownership as well as the tensions that stem from its emotional affordances. It addresses a lacuna in the housing literature regarding the turbulent everyday emotional tensions that buyers confront as they navigate the highly professionalized real estate industry. Homeownership is lauded for being a relatively low-risk tool for highly leveraged investment; however, using data drawn from a series of interviews conducted with participants over months and years, I demonstrate that first-time prospective homebuyers\u27 struggles to understand their feelings about buying often frustrates their abilities to make confident and clear housing decisions. Each chapter reflects on a different facet of the homebuying process, and taken as a whole the dissertation provides a kaleidoscopic view of what I call the homebuyer assemblage. In light of the recent turbulence in the national housing market, I argue that neglecting to attend to the intersection of financial logic, emotion, and social relations for prospective homebuyers leads to oversights in areas where housing studies must be developed