Control Parameters and Materials Selection Criteria for Rapid Prototyping Systems

Since the introduction ofrapid prototyping technology as a tool for time compression and concurrent engineering in the design and manufacturing process, many enhancements and refinements have been made based on the experience ofusers and manufacturers ofrapid prototyping equipment. These improvements contribute significantly to faster production of quality output from rapid prototyping systems. There are diverse control and material selection parameters that affect prototype models built using the Fused Deposition Modeling (FDM®) process. This paper reviews the role of several ofthese parameters in the process. Data will be presented to help the user choose the appropriate material for specific applications including density, tensile stiffhess, flexural stiffhess, tensile strength, flexural strength, tensile ductility, shock resistance, and hardness.Mechanical Engineerin

An interprofessional, intercultural, immersive short-term study abroad program: public health and service systems in rome

The purpose of this paper is to describe a short-term study abroad program that exposes engineering and nursing undergraduate students from the United States and Italy to an intercultural and interprofessional immersion experience. Faculty from Purdue University and Sapienza Università di Roma collaborated to design a technical program that demonstrates the complementary nature of engineering and public health in the service sector, with Rome as an integral component of the program. Specifically, the intersection of topics including systems, reliability, process flow, maintenance management, and public health are covered through online lectures, in-class activities and case study discussions, field experiences, and assessments. Herein, administrative issues such as student recruitment, selection, and preparation are elucidated. Additionally, the pedagogical approach used to ensure constructive alignment among the program goals, the intended learning outcomes, and the teaching and learning activities is described. Finally, examples of learning outcomes resulting from this alignment are provided

Mining digital identity insights: patent analysis using NLP

The field of digital identity innovation has grown significantly over the last 30 years, with over 6000 technology patents registered worldwide. However, many questions remain about who controls and owns our digital identity and intellectual property and, ultimately, where the future of digital identity is heading. To investigate this further, this research mines digital identity patents and explores core themes such as identity, systems, privacy, security, and emerging fields like blockchain, financial transactions, and biometric technologies, utilizing natural language processing (NLP) methods including part-of-speech (POS) tagging, clustering, topic classification, noise reduction, and lemmatisation techniques. Finally, the research employs graph modelling and statistical analysis to discern inherent trends and forecast future developments. The findings significantly contribute to the digital identity landscape, identifying key players, emerging trends, and technological progress. This research serves as a valuable resource for academia and industry stakeholders, aiding in strategic decision-making and investment in emerging technologies and facilitating navigation through the dynamic realm of digital identity technologies

Random walk of magnetic field lines for different values of the energy-range spectral index

An analytical nonlinear description of field-line wandering in partially statistically magnetic systems was proposed recently [A. Shalchi, I. Kourakis, Astronomy and Astrophysics, 470, 405 (2007)]. In this article we investigate the influence of the wave-spectrum in the energy-range onto field line random walk by applying this formulation. It is demonstrated that in all considered cases we clearly obtain a superdiffusive behaviour of the field-lines. If the energy-range spectral index exceeds unity a free-streaming behaviour of the field-lines can be found for all relevant length-scales of turbulence. Since the superdiffusive results obtained for the slab model are exact, it seems that superdiffusion is the normal behavior of field line wandering.Comment: Submitted to Physics of Plasmas; 13 pages, no figure

Nutrient-sensing mechanisms and pathways

The ability to sense and respond to fluctuations in environmental nutrient levels is a requisite for life. Nutrient scarcity is a selective pressure that has shaped the evolution of most cellular processes. Different pathways that detect intracellular and extracellular levels of sugars, amino acids, lipids and surrogate metabolites are integrated and coordinated at the organismal level through hormonal signals. During food abundance, nutrient-sensing pathways engage anabolism and storage, whereas scarcity triggers homeostatic mechanisms, such as the mobilization of internal stores through autophagy. Nutrient-sensing pathways are commonly deregulated in human metabolic diseases.National Institutes of Health (U.S.) (Grant R01 CA129105)National Institutes of Health (U.S.) (Grant R01 CA103866)National Institutes of Health (U.S.) (Grant R01 AI047389)National Institutes of Health (U.S.) (Grant R21 AG042876)American Federation for Aging ResearchStarr FoundationDavid H. Koch Institute for Integrative Cancer Research at MIT (Frontier Research Program)Ellison Medical FoundationCharles A. King TrustAmerican Cancer Society (Ellison Medical Foundation Postdoctoral Fellowship PF-13-356-01-TBE

FDM® Technology Process Improvements

Since the introduction ofrapid prototyping technology as a tool for time compression and concurrent engineering in the design and manufacturing process, many enhancements and refinements have been made based on the experience of users and manufacturers of rapid prototyping equipment. These improvements contribute significantly to faster production of quality output from rapid prototyping systems. There are diverse control and material selection parameters that affect prototype models built using the Fused Deposition Modeling (FDM®) process. This paper reviews the role of several of these parameters in the process. Data will be presented to help the user choose the appropriate material for specific applications including density, tensile modulus, flexural modulus, tensile strength, flexural strength, impact strength, and hardness. The integration of material, hardware, and software in the FDM technology begins with the understanding of the basic requirements ofthe machine and ends with an operating procedure to choose the parameters for optimal model output and efficiency. Some of the variables include: part geometry, deposition geometry, deposition speed, liquefier temperature, material, flow control parameters, etc. Designed experiments are used in material formulation through modeling parameter defmition activitiesMechanical Engineerin

Identification of the NIMA family kinases NEK6/7 as regulators of the p70 ribosomal S6 kinase

AbstractBackground: The p70 S6 kinase, like several other AGC family kinases, requires for activation the concurrent phosphorylation of a site on its activation loop and a site carboxyterminal to the catalytic domain, situated in a hydrophobic motif site FXXFS/TF/Y, e.g.,Thr412 in p70 S6 kinase (α1). Phosphorylation of the former site is catalyzed by PDK1, whereas the kinase responsible for the phosphorylation of the latter site is not known.Results: The major protein kinase that is active on the p70 S6 kinase hydrophobic regulatory site, Thr412, was purified from rat liver and identified as the NIMA-related kinases NEK6 and NEK7. Recombinant NEK6 phosphorylates p70 S6 kinase at Thr412 and other sites and activates the p70 S6 kinase in vitro and in vivo, in a manner synergistic with PDK1. Kinase-inactive NEK6 interferes with insulin activation of p70 S6 kinase. The activity of recombinant NEK6 is dependent on its phosphorylation, but NEK6 activity is not regulated by PDK1 and is only modestly responsive to insulin and PI-3 kinase inhibitors.Conclusion: NEK6 and probably NEK7 are novel candidate physiologic regulators of the p70 S6 kinase

Examining novel roles for the IκB kinase in coordinating the cellular response to metabolic stress

The induction of mammalian autophagy, a conserved cellular bulk-degradation process, was recently shown to require Inhibitor of κB (IκB) Kinase (IKK), the upstream regulator of nuclear factor (NF)-κB transcription factors. In response to cell stress IKK has been exclusively studied for its ability to activate NF-κB-dependent pro-inflammatory gene expression; surprisingly this activity is not required for starvation-induced autophagy and the mechanism by which IKK promotes this activity are largely unknown. Here we investigate the role of IKK/NF-κB pathway in response to both acute and prolonged nutrient deprivation, a classic autophagy- and novel NF-κB-inducing stimulus. We demonstrate that classic IKK-dependent NF-κB activation and gene expression occurs in response to cell starvation. Independently, IKK controls expression of genes necessary for autophagic machinery in response to prolonged starvation. The work presented in Chapter 2 will demonstrate that IKK is important molecule upstream of changes in gene expression induced by cellular starvation. IKK activity in response to acute starvation is also explored within and we identify that this kinase is important for transducing signals that inhibit growth and metabolic pathways. We find that IKK is required for inhibition of growth factor-dependent signaling through phosphorylation of the novel IKK substrate Phosphoinonsitide 3-Kinase (PI3K). The work outlined in Chapter 3 identifies a novel cross-talk mechanism between growth and stress responsive signal transduction pathways important for coordinating the cellular response to nutrient availability. In summary, the following manuscript will identify two novel functions for the IKK complex in regulating nutrient sensitive pathways, establishing the critical role of this kinase in cellular adaptation to metabolic stress

An Exact Renormalization Group analysis of 3-d Well Developed turbulence

We take advantage of peculiar properties of three dimensional incompressible turbulence to introduce a nonstandard Exact Renormalization Group method. A Galilean invariance preserving regularizing procedure is utilized and a field truncation is adopted to test the method. Results are encouraging: the energy spectrum E(k) in the inertial range scales with exponent -1.666+/- 0.001 and the Kolmogorov constant C_K, computed for several (realistic) shapes of the stirring force correlator, agrees with experimental data.Comment: 12 pg, 2figures, LaTex, To be published on Physics Letters