Polymers for spacecraft hardware - Materials characterization, part I Interim report, Mar. - Dec. 1966

Environmental testing of polymeric materials for spacecraft hardwar

Native American College Students: A Population That Can No Longer Be Ignored

Native Americans have the highest college drop out rate of any ethnic minority (Reddy, 1993). This paper addresses the unique challenges that Native American college students face, including suppressing familial and spiritual beliefs, having financial disadvantages, coping with existing stereotypes, receiving insufficient secondary education, and finding no one on campus with whom to identify. According to Brown and Robinson Kurpius (1997), “A common element of successful Native American drop out prevention programs is that at least one adult establishes a relationship of trust with each youth” (p. 5). In the spirit of the above-mentioned quote, this paper also addresses the importance of the involvement of student affairs offices in establishing connections with Native American students, which contributes to an improved college experience and increased retention of native students. Specifically, the counseling center, career services, and the ALANA (African, Latino/a, Asian, and Native American) student center are discussed

Advances in semantic representation for multiscale biosimulation: a case study in merging models

As a case-study of biosimulation model integration, we describe our experiences applying the SemSim methodology to integrate independently-developed, multiscale models of cardiac circulation. In particular, we have integrated the CircAdapt model (written by T. Arts for MATLAB) of an adapting vascular segment with a cardiovascular system model (written by M. Neal for JSim). We report on three results from the model integration experience. First, models should be explicit about simulations that occur on different time scales. Second, data structures and naming conventions used to represent model variables may not translate across simulation languages. Finally, identifying the dependencies among model variables is a non-trivial task. We claim that these challenges will appear whenever researchers attempt to integrate models from others, especially when those models are written in a procedural style (using MATLAB, Fortran, etc.) rather than a declarative format (as supported by languages like SBML, CellML or JSim’s MML)

Method of adhering bone to a rigid substrate using a graphite fiber reinforced bone cement

A method is described for adhering bone to the surface of a rigid substrate such as a metal or resin prosthesis using an improved surgical bone cement. The bone cement has mechanical properties more nearly matched to those of animal bone and thermal curing characteristics which result in less traumatization of body tissues and comprises a dispersion of short high modulus graphite fibers within a bonder composition including polymer dissolved in reactive monomer such as polymethylmethacrylate dissolved in methylmethacrylate monomer

Analysis of deployable strut roof structures

Thesis (M. Eng.)--Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.Cataloged from PDF version of thesis. "June 2013."Includes bibliographical references (pages 55-56).Deployable structures are structures that can change shape from a compact to an expanded form. Thus, their advantage over conventional structures is adaptability, whether in the sense of adapting to changing environmental conditions or being adapted for repeated transportation and deployment. These features make deployable structure highly desirable for a wide range of applications in the aerospace, military, and architectural fields. However, these structures are often only designed as small scale "products", rather than structures requiring full analysis and design procedures. Much work has focused on the various geometries of the deployment mechanisms without considering practical engineering aspects. If deployable structures are to be designed on the scale of large civil structures, a proper understanding of the flow of forces through the structure is required. This thesis begins with a brief discussion of deployable structures in general before moving on to geometric constraints of strut-type deployable structures. Then, it details a preliminary analysis of one class of deployable structures, known as angulated element structures. These structures are designed to be operable roofs spanning over sports facilities. During deployment, the center of the structure opens or closes to accommodate changes in weather conditions. Building on the geometry established in other work, the relationships between the basic geometric parameters of angulated element rings and their structural characteristics are determined. SAP2000 analysis results are used to make specific design recommendations. The feasibility of using this type of structure for an operable long span roof is confirmed.by Maxwell H. Wolfe.M.Eng

Using multiple reference ontologies: Managing composite annotations

There are a growing number of reference ontologies available across a variety of biomedical domains and current research focuses on their construction, organization and use. An important use case for these ontologies is annotation—where users create metadata that access concepts and terms in reference ontologies. We draw on our experience in physiological modeling to present a compelling use case that demonstrates the potential complexity of such annotations. In the domain of physiological biosimulation, we argue that most annotations require the use of multiple reference ontologies. We suggest that these “composite” annotations should be retained as a repository of knowledge about post-coordination that promotes sharing and interoperation across biosimulation models

Generalized Jarzynski Equality under Nonequilibrium Feedback Control

The Jarzynski equality is generalized to situations in which nonequilibrium systems are subject to a feedback control. The new terms that arise as a consequence of the feedback describe the mutual information content obtained by measurement and the efficacy of the feedback control. Our results lead to a generalized fluctuation-dissipation theorem that reflects the readout information, and can be experimentally tested using small thermodynamic systems. We illustrate our general results by an introducing "information ratchet," which can transport a Brownian particle in one direction and extract a positive work from the particle