An analysis of the heating and densification process during rotational molding of a thermoplastic powder in a uniaxially rotating cylindrical cavity

This dissertation presents the results of an experimental and theoretical investigation of the heating and densification portion of the rotational molding process in a uniaxial, cylindrical mold. A thorough literature survey is included which reviewed past analysis of the rotational molding process and other areas that assisted in understanding of the process. The results presented in this dissertation included an analysis of the densification process by use of Scanning Electronic Microscope (SEM) photography producing intermediate correlations between the physical properties of the densifying material and neck radius of adjacent coalescing spheres. In addition, a hybrid experimental procedure coupled with a small computer simulation was devised to determine the actual initial thermal conductivity and diffusivity of the powdered polymeric material. Finally, a computer program was written to simulate the heating and densification process during the rotational molding process. Results showed good agreement with actual experimental findings

Strategic planning research:toward a theory-driven agenda

This review incorporates strategic planning research conducted over more than 30 years and ranges from the classical model of strategic planning to recent empirical work on intermediate outcomes, such as the reduction of managers’ position bias and the coordination of subunit activity. Prior reviews have not had the benefit of more socialized perspectives that developed in response to Mintzberg’s critique of planning, including research on planned emergence and strategy-as-practice approaches. To stimulate a resurgence of research interest on strategic planning, this review therefore draws on a diverse body of theory beyond the rational design and contingency approaches that characterized research in this domain until the mid-1990s. We develop a broad conceptualization of strategic planning and identify future research opportunities for improving our understanding of how strategic planning influences organizational outcomes. Our framework incorporates the role of strategic planning practitioners; the underlying routines, norms, and procedures of strategic planning (practices); and the concrete activities of planners (praxis)

The Past, Present, and Future Direction of Computer Science Curriculum in K-12 Education

This integrated article thesis provides an analysis of the past, present, and potential future state of Computer Science (CS) in K-12 education. Once implemented in optional courses at the secondary level, CS concepts and skills are now being integrated into other subject areas such as mathematics, science, and technology and other grades including K-8. This new state of K-12 CS education is explored through an analysis of 1) related theory reflected in the literature, 2) historical secondary school CS curriculum, 3) enrolment data and important issues related to equity, diversity, and inclusion, and 4) K-8 CS-related curriculum approaches currently being implemented in educational jurisdictions across Canada. The four articles in this dissertation employ a qualitative approach to research, drawing on a constructivist epistemology. Thematic Analysis is used in the comparative analysis of historical curriculum documents from Ontario and Document Analysis is used in comparing the various K-8 curriculum documents from across Canada. Together, the chapters included in this integrated article thesis provide a comprehensive analysis of K-12 CS education that supports educators, policy makers, and researchers in the field during a transformative time

Experimental investigation of turbulent heat transfer in straight and curved rectangular ducts

An experimental investigation was conducted to examine the convective heat transfer in straight and curved ducts of rectangular cross-section. The experimental configuration was modeled at infinite parallel plates with one wall at a constant temperature and the opposite wall adiabatic. The experiments were conducted at steady state for turbulent flow. Average Nusselt numbers were used to compare the heat transfer characteristics of the straight and curved sections. The development of Taylor-Gortler vortices in the curved section was shown to enhance the heat transfer rate in the curved section as compared to that of the straight section by approximately 15-to 20 percent. Improved heat exchanger designs and improved cooling of turbine blades are two disciplines that could benefit from a better understanding of the effects of curvature on the rate of heat transfer.http://archive.org/details/experimentalinve00wilsLieutenant, United States NavyApproved for public release; distribution is unlimited

Homoiterons and expansion in ribosomal RNAs

AbstractRibosomal RNAs in both prokaryotes and eukaryotes feature numerous repeats of three or more nucleotides with the same nucleobase (homoiterons). In prokaryotes these repeats are much more frequent in thermophile compared to mesophile or psychrophile species, and have similar frequency in both large RNAs. These features point to use of prokaryotic homoiterons in stabilization of both ribosomal subunits. The two large RNAs of eukaryotic cytoplasmic ribosomes have expanded to a different degree across the evolutionary ladder. The big RNA of the larger subunit (60S LSU) evolved expansion segments of up to 2400 nucleotides, and the smaller subunit (40S SSU) RNA acquired expansion segments of not more than 700 nucleotides. In the examined eukaryotes abundance of rRNA homoiterons generally follows size and nucleotide bias of the expansion segments, and increases with GC content and especially with phylogenetic rank. Both the nucleotide bias and frequency of homoiterons are much larger in metazoan and angiosperm LSU compared to the respective SSU RNAs. This is especially pronounced in the tetrapod vertebrates and seems to culminate in the hominid mammals. The stability of secondary structure in polyribonucleotides would significantly connect to GC content, and should also relate to G and C homoiteron content. RNA modeling points to considerable presence of homoiteron-rich double-stranded segments especially in vertebrate LSU RNAs, and homoiterons with four or more nucleotides in the vertebrate and angiosperm LSU RNAs are largely confined to the expansion segments. These features could mainly relate to protein export function and attachment of LSU to endoplasmic reticulum and other subcellular networks

Heroes or Villains? Recasting Middle Management Roles, Processes, and Behaviours

Middle management ranks are once again being questioned by scholars and practitioners alike. This introduction to the special issue represents a timely reference point for consolidating, reviving, and guiding the next wave of researchers seeking to engage this debate. We review the foundations and recent advances in middle management research and develop an organizing framework in terms of middle management's organizational roles, coordination processes, and agentic behaviours. We also identify how new ways of organizing, technology, and middle manager needs are changing to shape each of these themes. The collection of works we synthesize in this introduction offer theoretical advances and empirical evidence on how these changes affect middle management roles, processes, and behaviours. We conclude by mapping out promising research avenues for future research in middle management

Controlling High Bandwidth Aggregates in the Network

The current Internet infrastructure has very few built-in protection mechanisms, and is therefore vulnerable to attacks and failures. In particular, recent events have illustrated the Internet's vulnerability to both denial of service (DoS) attacks and flash crowds in which one or more links in the network (or servers at the edge of the network) become severely congested. In both DoS attacks and flash crowds the congestion is due neither to a single flow, nor to a general increase in traffic, but to a well-defined subset of the traffic --- an aggregate. This paper proposes mechanisms for detecting and controlling such high bandwidth aggregates. Our design involves both a local mechanism for detecting and controlling an aggregate at a single router, and a cooperative pushback mechanism in which a router can ask upstream routers to control an aggregate. While certainly not a panacea, these mechanisms could provide some needed relief from flash crowds and flooding-style DoS attacks. The presentation in this paper is a first step towards a more rigorous evaluation of these mechanisms

Growth functions on Fuchsian groups and the Euler characteristic

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46618/1/222_2005_Article_BF01405088.pd

Managing Goal Heterogeneity in Strategic Initiatives

Strategic initiatives are temporary group undertakings designed to renew organizational capabilities and are crucial to organizational performance. Despite the inherent goal heterogeneity stemming from individual, departmental, organizational, and initiative levels, research conceptualizes goals as unitary within the team. Our objective is to explore ways to manage goal heterogeneity for the successful development of strategic initiatives within the intraorganizational context. We argue that organizational controls and decision comprehensiveness can be effective in mitigating the negative effects of heterogeneity. This will help facilitate a group of individuals in behaving as a team and being committed to the agreed-upon task at hand. We also articulate the positive role of strategic consensus in moving initiatives in the resource allocation process. Our theory building provides a roadmap for managing strategic initiatives in the resource allocation process and contributes to research on strategic initiatives and goals and, more broadly, to behavioral theory