Real time thermal imaging of high temperature semiconductor melts

A real time thermal imaging system with temperature resolution better than + or - 1 C and spatial resolution of better than 0.5 mm was developed and applied to the analysis of melt surface thermal field distributions in both Czochralski and liquid encapsulated Czochralski (LEC) growth configurations. The melt is viewed in near normal incidence by a high resolution charge coupled device camera to which is attached a very narrow bandpass filter. The resulting image is digitized and processed using a pipelined pixel processor operating at an effective 40 million operations per second thus permitting real time high frequency spatial and temporal filtering of the high temperature scene. A multi-pixel averaging algorithm was developed which permits localized, low noise sensing of temperature variations at any location in the hot zone as a function of time. This signial is used to implement initial elements of a feedforward growth control scheme which is aimed at reducing disturbances to the melt caused by the batch nature of the growth process. The effect of magnetic melt stabilization on radial melt temperature distributions was measured using this technique. Problems associated with residual internal reflections and non-optimized path geometry are discussed

Use of anomolous thermal imaging effects for multi-mode systems control during crystal growth

Real time image processing techniques, combined with multitasking computational capabilities are used to establish thermal imaging as a multimode sensor for systems control during crystal growth. Whereas certain regions of the high temperature scene are presently unusable for quantitative determination of temperature, the anomalous information thus obtained is found to serve as a potentially low noise source of other important systems control output. Using this approach, the light emission/reflection characteristics of the crystal, meniscus and melt system are used to infer the crystal diameter and a linear regression algorithm is employed to determine the local diameter trend. This data is utilized as input for closed loop control of crystal shape. No performance penalty in thermal imaging speed is paid for this added functionality. Approach to secondary (diameter) sensor design and systems control structure is discussed. Preliminary experimental results are presented

Microgravity: a Teacher's Guide with Activities, Secondary Level

This NASA Educational Publication is a teacher's guide that focuses on microgravity for the secondary level student. The introduction answers the question 'What is microgravity?', as well as describing gravity and creating microgravity. Following the introduction is a microgravity primer which covers such topics as the fluid state, combustion science, materials science, biotechnology, as well as microgravity and space flight. Seven different activities are described in the activities section and are written by authors prominent in the field. The concluding sections of the book include a glossary, microgravity references, and NASA educational resources

To Be or Not to Be: The Progression of the Union

Labor unions were established in the early twentieth century, and they continue to be a major part of today\u27s business culture. A debate on this topic of unions is generally energetic and emotional, with strong opinions expressed by suppliers and dissenters of the union concept. The focus of this thesis is to review the history and purpose of unions, provide examples of companies\u27 experiences with unions, and to objectively discuss the advantages and disadvantages of organized labor to the employees, the management, and customers of union companies. It is imperative for companies and employees to make a well-informed decision on unions instead of one based on emotion

Into the Fray: Social Justice Teaching Gone Awry

This article provides an account of the author\u27s experience trying to teach through a social justice lens in a conservative Southern town after having taught primarily in more progressive parts of the country. She discusses the mistakes she made and what she learned from them throughout the experience that has made her a better teacher of students with vastly different ideologies than her own

Microgravity: A Teacher's Guide With Activities in Science, Mathematics, and Technology

The purpose of this curriculum supplement guide is to define and explain microgravity and show how microgravity can help us learn about the phenomena of our world. The front section of the guide is designed to provide teachers of science, mathematics, and technology at many levels with a foundation in microgravity science and applications. It begins with background information for the teacher on what microgravity is and how it is created. This is followed with information on the domains of microgravity science research; biotechnology, combustion science, fluid physics, fundamental physics, materials science, and microgravity research geared toward exploration. The background section concludes with a history of microgravity research and the expectations microgravity scientists have for research on the International Space Station. Finally, the guide concludes with a suggested reading list, NASA educational resources including electronic resources, and an evaluation questionnaire

Drainage Patterns in the Alambre Valley, Arizona

Author Institution: Department of Geology, Miami University, Oxford, Ohi

HYPERCONNECTED SCHOOL LEADERSHIP: SHARED EXPERIENCES

Leaders remain perpetually connected to their work because of the rapid advancement of information technology. This research, using a qualitative approach, explored how increased connective technology is affecting school leaders with the central question: How is hyperconnectivity experienced by school leaders? Using personal interviews, the lived experiences of fifteen international middle and high school principals with one-to-one student-to-device programs were collected. Raw transcriptions of their experiences were analyzed using the descriptive phenomenological approach as outlined by Giorgi (2009). This approach allowed for the data to be reduced into a single narrative description shared by all participants indicating the essences of their lived experience as hyperconnected school leaders. This shared narrative highlighted complex and paradoxical experiences associated with how these school leaders interact with technology. Their experiences indicated that work-life balance for hyperconnected leaders required strong personal boundaries and skillful use of connective technologies. Examples of effective leader development of self and community highlighted, paradoxically, the need to unplug to effectively deploy connected technology within their leadership practice. Conversely, this study also showed how leaders can be controlled by connectivity. They associated their roles as responsible school leaders with perpetual connectivity; in consequence, they fused their work and home lives, experienced increased stress, and struggled with work overload. These results imply that international school principals are impacted by increased connectivity in different ways. Findings from this study indicate those leading hyperconnected schools must pay attention to how connectivity is affecting themselves and members of their school communities. Principals must protect themselves from the increasing demands upon their attention that constant connectivity presents in order to make mental room for the self-reflection and creativity needed to provide novel solutions and approaches towards their leadership work