Stephanie van Hover, David Hicks, Elizabeth Washington and Melissa Lisanti
This study examined and traced the relationship between, and the influence of, the official standards documents of the Commonwealth of Virginia, and the related day-to-day lesson…
Abstract
This study examined and traced the relationship between, and the influence of, the official standards documents of the Commonwealth of Virginia, and the related day-to-day lesson planning and implementation of a pair of co-teachers. Using a case study methodology alongside a conventional content analysis we traced the processes of how these policy texts (the Standards of Learning [SOLs] for World History) were connected to and activated within the daily routines of these teachers who taught struggling students in a high-stakes testing context. The findings illustrated how the policy texts and discursive practices emerging from the State’s SOLs constituted a level of pedagogical governance that saw these teachers organize instruction clearly designed to support student recall on the end of year multiple choice test. Our work recognized the power of policy texts as they interact with teachers. The significance of unpacking policy documents in order to examine issues of power, symmetry and potential areas of negotiation in the planning and implementation of instruction for teacher educators is discussed.
Details
Keywords
Stephanie van Hover, David Hicks and Elizabeth Washington
This qualitative case study explores how one secondary world history teacher, teaching in a high-stakes testing context in a district pushing teachers to utilize differentiated…
Abstract
This qualitative case study explores how one secondary world history teacher, teaching in a high-stakes testing context in a district pushing teachers to utilize differentiated instruction, makes sense of this pedagogical approach. We examine teacher sense-making within a conceptual framework of policy realization and ambitious teaching and learning. The teacher made no claims to being an expert on differentiation; yet, the findings indicated that she did possess an understanding of differentiation congruent with the literature and, whether she recognized it or not, used many strategies suggested by Tomlinson and other experts on differentiation. Her thinking about differentiation also appeared to be shaped by relational and contextual issues. Stated differently, the Virginia Standards of Learning exams and the pressure from administration for high pass rates appeared to shape how the teacher thought about her students, her content, her instruction and, ultimately, her approach to differentiation.
Details
Keywords
Per V. Jenster and David Hover
This flavor industry case takes a clinical look at a global firm's complex marketing research practices. The reader's job: Find the set of opportunities that constitute a…
An analysis is made or the basic principles which govern the operation of those air‐cushion devices otherwise known as ground‐effect machines (GEMs). Most of these vehicles can be…
Abstract
An analysis is made or the basic principles which govern the operation of those air‐cushion devices otherwise known as ground‐effect machines (GEMs). Most of these vehicles can be defined as machines which operate in close proximity to the earth's surface without ever physically touching it because they are always separated from it by a cushion or a layer of air, however thin; as a consequence, propulsion and control of GEMs must be of an aerodynamic nature. The only machines not covered by this definition are special types of over‐water GEMs. It is proposed to establish six main categories of GEMs from which all other possible configurations could be evolved by proper combination of the basic types. For each of these six configurations, a critical biographical survey is made and some comparative features are pointed out. The overall picture is one of great complexity because of the large number of parameters involved. This points out the danger of a ‘hardware’ approach to the GEM problem until a firm base of comprehensive research has been established. At the present time, the emphasis placed on the annular jet seems justified, inasmuch as the annular jet represents a good compromise between versatility, simplicity and performance.
The basis and the extent of theoretical induced velocity calculations are reviewed. The theory is then applied to interference problems involving additional rotors, wings, and…
Abstract
The basis and the extent of theoretical induced velocity calculations are reviewed. The theory is then applied to interference problems involving additional rotors, wings, and tails in the flow. For such cases, the interference effects can be calculated with acceptable accuracy. For hovering, superposition is used to introduce ground effect into the calculations. The resulting flow field offers a qualitative explanation of several previously observed phenomena. It is shown that, because of assumptions inherent in the analysis, the present induced‐flow theory cannot be used to predict the detailed aerodynamic loading on the rotor blades.
Car‐owning elitists must have viewed with considerable apprehension the takeover last year of ailing Aston Martin by a property and investment concern, headed by William Willson…
Abstract
Car‐owning elitists must have viewed with considerable apprehension the takeover last year of ailing Aston Martin by a property and investment concern, headed by William Willson. Instead of a predicted asset stripping operation, however, Willson set himself the task of putting AM on a profitable footing, while at the same time retaining the company's reputation for craftsmanship. Willson says he has no intention of expanding production beyond the 500 cars‐a‐year target—even if demand should exceed this level. Report by Andrew Furnival and Chris Phillips.
Benoit Picard, Mathieu Picard, Jean-Sébastien Plante and David Rancourt
The limited energy density of batteries generates the need for high-performance power sources for emerging eVTOL applications with radical operational improvement potential over…
Abstract
Purpose
The limited energy density of batteries generates the need for high-performance power sources for emerging eVTOL applications with radical operational improvement potential over traditional aircraft. This paper aims to evaluate on-design and off-design recuperated turbogenerator performances based on newly developed compression loaded ceramic turbines, the Inside-out Ceramic Turbine (ICT), in order to select the optimum engine configuration for sub-megawatt systems.
Design/methodology/approach
System-level thermal engine modeling is combined with electric generators and power electronics performance predictions to obtain the Pareto front between efficiency and power density for a variety of engine designs, both for recuperated and simple cycle turbines. Part load efficiency for those engines are evaluated, and the results are used for an engine selection based on a simplified eVTOL mission capability.
Findings
By operating with high turbine inlet temperature, variable output speed and adequately sized recuperator, a turbogenerator provides exceptional efficiency at both nominal power and part load operation for a turbomachine, while maintaining the high power density required for aircraft. In application with a high peak-to-cruise power ratio, such power source would provide eight times the range of battery-electric power pack and an 80% improvement over the state-of-the-art simple cycle turbogenerator.
Practical implications
The implementation of a recuperator would provide additional gains especially important for military and on-demand mobility applications, notably reducing the heat signature and noise of the system. The engine low-pressure ratio reduces its complexity and combined with the fuel savings, the system could significantly reduce operational cost.
Originality/value
Implementation of radically new ICT architecture provides the key element to make a sub-megawatt recuperated turbogenerator viable in terms of power density. The synergetic combination of a recuperator, high temperature turbine and variable speed electric generator provides drastic improvement over simple-cycle turbines, making such a system highly relevant as the power source for future eVTOL applications.
Details
Keywords
David Kofi Oppong, Evans Obu, Timothy Asare and God'sable Sitsofe Koku Aidam
This study aims to present details of the development and validation of the multicopter modelling code (MMC), a tool for the analysis of small-scale multicopters based on flight…
Abstract
Purpose
This study aims to present details of the development and validation of the multicopter modelling code (MMC), a tool for the analysis of small-scale multicopters based on flight physics.
Design/methodology/approach
The development effort involved the study of aircraft dynamics and translating the equations of motion into MATLAB code. The authors also developed several auxiliary functions, so that the tool could trim the aircraft about a steady state, linearize the dynamic equations to produce a model that could be used for control systems design and carry out flight simulation.
Findings
MMC proved to be of good accuracy, producing results similar to those of other software such as AcuSolve, Overflow and the Rensselaer Multicopter Analysis Code (RMAC), which served as the motivation for this study.
Originality/value
The tool presented here provides an alternative to the aforementioned software, which are not freely available, programmed in MATLAB, a language well known to engineers and scientists.
Details
Keywords
After considering the material before me, I have formed the opinion that it shall be permitted for the petitioner to examine the file under scrutiny. Deliberation on the case did…
Abstract
After considering the material before me, I have formed the opinion that it shall be permitted for the petitioner to examine the file under scrutiny. Deliberation on the case did not take place behind closed doors and there is no lawful prohibition to the examination…in addition I accept the position of the respondent, according to which in spite of the fact that a large portion of the details of the affair were published in the judgment…the file contains material whose revelation can cause unnecessary harm to the central witness…the examination considered will be contingent on an undertaking in writing…according to which the petitioner will not publicize anything that will damage the privacy of the victims and their families beyond the damage that already occurred by the court judgment. (Decision of magistrate Yigaal Marzel, 2006 in the matter of C.A 125/50 Yaakobowitz v. Attorney General)
This letter to David R. Maines celebrates our friendship over the last 35 years. I read his voice in emails, handwritten letters, and recollected phone conversations to display…
Abstract
This letter to David R. Maines celebrates our friendship over the last 35 years. I read his voice in emails, handwritten letters, and recollected phone conversations to display the meaningful exchanges of our scholarly friendship. I thank Dave for teaching me how to retire from the academy and grow older with purpose and grace. Highlighting his expert mentoring of my book Friendship Matters (1992), I recall how his suggested revisions for the chapters on aging anticipated a poignant array of our own experiences as friends in our later years. Finally, I appreciate his cultivated interests in drawing, writing poetry, and playing guitar, and thank him for encouraging my music. I am grateful for his dedication to esthetic endeavors, which warmly shaped our friendship during our later years.