Solar sail formation flying for deep-space remote sensing

In this paper we consider how 'near' term solar sails can be used in formation above the ecliptic plane to provide platforms for accurate and continuous remote sensing of the polar regions of the Earth. The dynamics of the solar sail elliptical restricted three-body problem (ERTBP) are exploited for formation flying by identifying a family of periodic orbits above the ecliptic plane. Moreover, we find a family of 1 year periodic orbits where each orbit corresponds to a unique solar sail orientation using a numerical continuation method. It is found through a number of example numerical simulations that this family of orbits can be used for solar sail formation flying. Furthermore, it is illustrated numerically that Solar Sails can provide stable formation keeping platforms that are robust to injection errors. In addition practical trajectories that pass close to the Earth and wind onto these periodic orbits above the ecliptic are identified

Metadata for describing learning scenarios under European Higher Education Area paradigm

In this paper we identify the requirements for creating formal descriptions of learning scenarios designed under the European Higher Education Area paradigm, using competences and learning activities as the basic pieces of the learning process, instead of contents and learning resources, pursuing personalization. Classical arrangements of content based courses are no longer enough to describe all the richness of this new learning process, where user profiles, competences and complex hierarchical itineraries need to be properly combined. We study the intersection with the current IMS Learning Design specification and the additional metadata required for describing such learning scenarios. This new approach involves the use of case based learning and collaborative learning in order to acquire and develop competences, following adaptive learning paths in two structured levels

A Review of Court Cases Involving Discrimination in Physical Ability Testing: 1992-2015

Organizations that employ physically demanding jobs want to ensure their selection procedures distinguish qualified applicants from unqualified applicants. However, such selection tools typically result in adverse impact against various protected groups and often lead to litigation. Various factors influence the court’s decision to rule in favor of the plaintiff or the defendant. The purpose of the present study is to identify those factors. The ADA (1990) created strict guidelines for plaintiffs and defendants to follow to be credible in a discrimination case. This study will specifically determine the impact of the ADA guidelines and three additional factors that influence court decisions including job analysis and test validation procedures, and whether the job involves public safety. Organizations can benefit from knowing factors they can control to decrease legal liability. Cases filed from 1992 to the present were reviewed and coded based on each factor. Z-tests for proportions were conducted to determine the proportions of rulings in favor of the plaintiff and defendant based on each factor of interest. Public safety influences the court decisions in favor of the defendant, such that for jobs in which public safety is of concern, the court is more likely to rule in favor of the defendant. Additional factors were not significantly influential. However, some trends are apparent and discussed in the paper. Implications and limitations also are discussed

A Supervisory Program For Elementary Schools

The problem of this report specifically stated is as follows: Supervisory program For Elementary Schools. The basic idea is to set up a supervisory program that will be workable and helpful in improving instruction in the smaller schools in communities of the second and third class in Kansas

Textural Variations in Some Iowa Limestones

Textural properties of limestones assume a large importance in determining the origin of the rocks. Limestones are usually called detrital rocks if they possess oolitic, pelleted or coquoinoid texture (Pettijohn, 1957, p. 401). This criterion as to whether the rock was formed by current-sorted detritus or direct chemical precipitation is valid if, and only if, the rock texture has remained essentially unchanged during diagenesis. Because many of the Mississippi limestones of Iowa display pellet textures, it is desirable to determine, if possible, the true nature of this texture, and its mode of origin, and whether it reflects a depositional or diagenetic environment

Factors Which Influenced the Development of Jonathan Edwards

\u27The real life of Jonathan Edwards was the life of his Mind.” Her s the perfect example of a writer who emerged out of the passions, the feuds, and the anxieties of his society. Thus, in dealing with Jonathan Edwards and the thought which influenced New England for nearly a century after his death, it is necessary to deal first of all with the passions, the feuds, and the anxieties from which he arose. Without these there can really be no true understanding of\u27 the man and his thought. It is legitimate to ask the question, “What are the factors that influenced the development of Jonathan Edwards? This is the question which will be explored in the body of this paper

Development, fabrication and test of a high purity silica heat shield

A highly reflective hyperpure ( 25 ppm ion impurities) slip cast fused silica heat shield material developed for planetary entry probes was successfully scaled up. Process development activities for slip casting large parts included green strength improvements, casting slip preparation, aggregate casting, strength, reflectance, and subscale fabrication. Successful fabrication of a one-half scale Saturn probe (shape and size) heat shield was accomplished while maintaining the silica high purity and reflectance through the scale-up process. However, stress analysis of this original aggregate slip cast material indicated a small margin of safety (MS. = +4%) using a factor of safety of 1.25. An alternate hyperpure material formulation to increase the strength and toughness for a greater safety margin was evaluated. The alternate material incorporates short hyperpure silica fibers into the casting slip. The best formulation evaluated has a 50% by weight fiber addition resulting in an 80% increase in flexural strength and a 170% increase in toughness over the original aggregate slip cast materials with comparable reflectance

Rethinking legal skills education in an LLB curriculum

Over the past decade, there have been growing complaints regarding the low levels of literacy, research and numeracy skills demonstrated by law graduates in practice, and a call for universities to more adequately address these skill gaps. The Faculty of Law at the Nelson Mandela Metropolitan University (NMMU) responded to this call by redesigning their first-year Legal Skills course using a stand-alone skills-based model and a context-based teaching approach. The redesign process is outlined and particular themes in each stage of the process are discussed. This includes identifying contextual factors, defining essential skills; course content analysis; course restructuring; teaching reformulation; adaptation of assessment and feedback; implementing a blended learning approach, and collaboration within the Faculty and across faculties and service providers. The article argues that a stand-alone skills-based model can be effective in developing a minimum level of competence, but that a sense of shared responsibility for skills development across the LLB programme is essential for a higher level of skill attainment. Lessons learned during the redesign process are highlighted, and where possible, recommendations for future considerations are explored

Food System Transformation: Integrating a Political-Economy and Social-Ecological Approach to Regime Shifts.

Sustainably achieving the goal of global food security is one of the greatest challenges of the 21st century. The current food system is failing to meet the needs of people, and at the same time, is having far-reaching impacts on the environment and undermining human well-being in other important ways. It is increasingly apparent that a deep transformation in the way we produce and consume food is needed in order to ensure a more just and sustainable future. This paper uses the concept of regime shifts to understand key drivers and innovations underlying past disruptions in the food system and to explore how they may help us think about desirable future changes and how we might leverage them. We combine two perspectives on regime shifts-one derived from natural sciences and the other from social sciences-to propose an interpretation of food regimes that draws on innovation theory. We use this conceptualization to discuss three examples of innovations that we argue helped enable critical regime shifts in the global food system in the past: the Haber-Bosch process of nitrogen fixation, the rise of the supermarket, and the call for more transparency in the food system to reconnect consumers with their food. This paper concludes with an exploration of why this combination of conceptual understandings is important across the Global North/ Global South divide, and proposes a new sustainability regime where transformative change is spearheaded by a variety of social-ecological innovations

Divergences in QED on a Graph

We consider a model of quantum electrodynamics (QED) on a graph. The one-loop divergences in the model are investigated by use of the background field method.Comment: 14 pages, no figures, RevTeX4. References and typos adde