Preliminary investigation of high power microwave plasmas for electrothermal thruster use

Results are reported from preliminary tests to evaluate the high power microwave electrothermal thruster (MET) concept, which employs a free-floating plasma discharge maintained by applied CW microwave power to heat a propellant gas flow. Stable plasmas have been created and maintained in helium (He), nitrogen (N2), and hydrogen (H2) as propellants in both the TM(sub 011) and TM(sub 012) modes at discharge pressures from 10 Pa to 69 kPa. Reproducible starting conditions of pressure and power have been documented for all the plasmas. Vortical inflow of the propellant gas was observed to cause the formation of on-axis 'spike' plasmas. The formation and unformation conditions of these plasmas were studied. Operation in the spike plasma condition enables maximum power absorption with minimum wall heating and offers maximum efficiency in heating the propellant gas. In the spike condition, plasmas of the three propellant gases were investigated in an open channel configuration to a maximum applied power level of 11.2 kW (in N2). Microwave power coupling efficiencies of over 90 percent were routinely obtained at absorbed power levels up to 2 kW. Magnetic nozzle effects were investigated with a superconducting solenoid Al magnet applying a high magnetic field to the plasmas in and exiting from the discharge tube

Specifying An Expanded Framework for Classifying and DescribingDecision Support Systems

This article defines an expanded conceptual framework for classifying and describing Decision Support Systems (DSS) that consists of one primary dimension and three secondary dimensions. The primary dimension is the dominant technology component or driver of decision support. The three secondary dimensions are the targeted users, the specific purpose of the system and the primary deployment or enabling technology. Five generic DSS types are identified and defined based upon the dominant technology component, including Communications-driven, Data-driven, Document-driven, Knowledge-driven, and Model-driven Decision Support Systems. Specific targeted users like individuals, groups, or customers can use any of the five generic types of DSS. Also, a DSS can be created for a decision- specific or a more general purpose. Finally, in the framework, the DSS deployment and enabling technology may be a mainframe computer, a client/server LAN, a spreadsheet or a web-based technology architecture. The goal in defining an expanded DSS framework is to help researchers better identify meaningful, homogeneous categories for research and to help Information Systems professionals describe and explain the various types of decision support systems

The IS Core-II: The Maturing IS Discipline: Institutionalizing our Domain of Inquiry

Even though computerized information systems are a relatively recent phenomenon that continues to evolve, these technology-based systems are now studied by a maturing academic discipline. This article examines the issue of Information Systems (IS) core concepts; explores the content and boundaries of the Information Systems research domain; and discusses whether consensus about an identity and domain for Information Systems is important and worth discussing. Despite concerns in the profession about an IS identity crisis, Information Systems is a legitimate area of scientific research and inquiry. Groups like the Association for Information Systems are institutionalizing the IS domain of inquiry. Furthermore, Information Systems researchers are becoming much more assertive about the importance of the IS research domain

Web-Based and Model-Driven Decision Support Systems: Concepts and Issues

New technologies, especially the World-Wide Web technologies, have created many opportunities for research about Decision Support Systems. This paper reviews key concepts and technical issues. The technology of DSS is evolving rapidly and academic researchers need to catch-up with practitioners who are implementing innovative DSS. The paper briefly mentions a number of Web sites with innovative DSS that highlight current developments. Much remains however to be investigated and studied if DSS are to contribute to a company’s success

A History of Microcomputer Spreadsheets

In 1978, the first microcomputer spreadsheet program was developed. Since then spreadsheets have become widely used as productivity software for business and home computer users. Many of today\u27s MIS faculty members use a variety of spreadsheet programs, but the origins and evolution of this product category is of on-going interest to students, managers and MIS faculty. This article is a contemporary history of microcomputer spreadsheets based on primary and secondary sources

Improved LeRoy-Bernstein near-dissociation expansion formula. Tutorial application to photoassociation spectroscopy of long-range states

NDE (Near-dissociation expansion) including LeRoy-Bernstein formulas are improved by taking into account the multipole expansion coefficients and the non asymptotic part of the potential curve. Applying these new simple analytical formulas to photoassociation spectra of cold alkali atoms, we improve the determination of the asymptotic coefficient, reaching a 1% accuracy, for long-range relativistic potential curve of diatomic molecules.Comment: This article is part of Daniel Comparat's PhD thesis available at http://tel.ccsd.cnrs.fr

Workplace Health Promotion: Effects of an mHealth application on Employee Behaviour and Wellness

Organizations are using digital tools to support workplace health promotion (WHP) initiatives. This study investigates the effects of a mobile health (mHealth) application on employee behaviour and wellness. This exploratory, empirical case study was conducted as part of an established workplace health initiative in the Health Service Executive (HSE) in Ireland, April 2018. User data on exercise including daily activity in the form of steps taken, mood, total daily exercise, and other variables were captured as part of the ‘Steps to Health Challenge’. Phase 1 of the study involved the collection of user data from 70 active app users and a survey was conducted. The majority of participants found that the mHealth app motivated them to sustain, and in some cases increase, their daily steps. Phase 2 involved interviews. Following qualitative data analysis, we found that the app positively effected employee behaviour; specific features were highlighted as especially influential

Heliocentric Escape and Lunar Impact from Near Rectilinear Halo Orbits

Spacecraft departing from the Gateway in a Near Rectilinear Halo Orbit (NRHO) experience gravitational forces from the Moon, the Earth, and the Sun, all of which can be simultaneously significant. These complex dynamics influence the post-separation risk of recontact with the Gateway and the eventual destinations of the departing spacecraft. The current investigation examines the flow of objects leaving NRHOs in the Bicircular Restricted Four-Body Problem, and results are applied to heliocentric escape and lunar impact trajectories in a higher-fidelity ephemeris model. Separation maneuver magnitude, direction, and location are correlated with risk of recontact with the Gateway and successful departure to various destinations

Decision Support Systems: Concepts and Resources for Managers

For MIS specialists and nonspecialists alike, teacher and consultant Dan Power provides a readable, comprehensive, understandable guide to the concepts and applications of decision support systems. Not only does his book help enhance your DSS design and development capabilities, it also shows how DSS can buttress organization goals and the impact DSS have throughout organizations and at all levels of management. Power defines DSS broadly: interactive computer-based systems and subsystems that help people use computer communications, data, documents, knowledge, and models to solve problems and make decisions. He focuses his book on practical applications, but also includes important and relevant empirical research and underlying theory. His book thus provides enough concrete detail to help grasp the essentials of DSS, but it also gives advanced tips and suggestions to DSS specialists too. For people trained in fields outside the information sciences, Power\u27s book is especially valuable. It gives them the knowledge they need to work with their MIS colleagues and to truly appreciate the management value of information technology overall. Power makes clear that decision support systems differ and that managers must specify what they want, based on their needs and the purposes to which the systems will be put. They should know how to build DSS and understand the basics of networking, security, and web-based DSS. Thus, of special interest is the structure that Power uses to organize his book. In Chapter 1 he presents an expanded framework for categorizing DSS. Chapters 2-5 provide a general managerial and technical perspective on building DSS. In Chapters 7 through 11 he lays out the details and gives examples of the general types of DSS. The last chapter, Evaluating Decision Support System Projects, reviews and discusses the tools and issues associated with assessing proposals for DSS projects. The book also includes a glossary and DSS audit questions, giving it special, ongoing value to all readers. -- Provided by publisherhttps://scholarworks.uni.edu/facbook/1066/thumbnail.jp

Reflections on Faculty Participation in University Decision Making

In 1983, when I began my career, a University was a place where professors met students for instruction and research. A University granted degrees upon the recommendation of the faculty to students who had satisfactorily completed courses and met degree requirements established by faculty. Universities had governing boards that ratified strategic administrative and academic decisions. Faculty, especially tenured faculty, had a meaningful role in decisions related to the selection of administrators, hiring and promoting faculty, budgeting, and determination of educational policies. In general, the governance boards deferred to the expertise of faculty and administrators. Academic administrators and many people performing other duties, such as a Dean of Students or Registrar, had been faculty members