1,239 research outputs found

    Ophthalmic method and apparatus

    Get PDF
    A method and apparatus for removing material and components such as the lens from an eye is described. High speed rotary cutting members at one end of a rod macerate the lens while an annular tubing disposed around the cutting members vibrates ultrasonically to coact with the cutting members in macerating the lens. At the same time, a liquid is supplied to the chamber behind the cornea of the eye. Spiral grooves extending along the rotating rod from the cutting members evacuate the liquid and the macerated material from the eye. An alternate embodiment of the apparatus includes a tube through which liquid is supplied to the operative site of the ultrasonically vibrating tube and the cutting members in the area of the lens

    Paper Session I-B - In-Space Operations for Lunar and Mars Space Transfer Vehicles

    Get PDF
    The objective of this paper is to discuss the in-space operations required to process the lunar and Mars mission vehicles envisioned in early studies for the Space Exploration Initiative (SEI). Recent studies, which have examined the Degree to which on-orbit operations change as a function of the Earth-to-orbit (ETO) launch vehicle size, identified a common set of on-orbit vehicle processing tasks, and generated functional requirements for in-space processing nodes, are summarized in this paper

    Simplex: A Program of Inexpensive Planetary Exploration

    Get PDF
    During the 1960\u27s and 70 \u27s the United States sent a multitude of small spacecraft on interplanetary and lunar flights. These early probes were used as simple precursors for the larger more sophisticated interplanetary vehicles that followed. Although the larger vehicles were extremely successful and scientifically rewarding, they were also very costly. Today, there are fewer planetary missions and even these have come under tight budgetary restrictions. Although the National Commission on Space and the NASA- Solar System Exploration Committee have identified a series of goals for the planetary exploration program, some of those goals could be compromised due to budget considerations related to the use of large and .expensive vehicles. This paper proposes that a program utilizing a series of Small Inexpensive Modular Planetary and Lunar Explorer (SIMPLEX) spacecraft be created. The goal of this program would be to supplement large expensive spacecraft with small inexpensive ones. A set of common spacecraft busses, with off-the-shelf propulsion, power, data, and communications sysrtems would be used as the core vehicles. Simple scientific instruments are integrated into the standard bus for each mission. All of the SIMPLEX spacecraft can be launched on a variety of launch vehicles. Several of these spacecraft have already been designed and built, such as the Orion, from the Naval Postgraduate School, and the Lunar Get Away Special project from the Jet Propulsion Laboratory. The SIMPLEX program would use several .of these spacecraft to explore the Moon, Mars and small near-Earth objects such as asteroids and comets. Such a program could be established for a relatively low cost and would augment existing and future planetary exploration programs. 1

    Service Design Capabilities

    Get PDF
    This open access book discusses service design capabilities in innovation processes, and provides a framework that guides design students, practitioners and researchers towards a better understanding of operational aspects of service design processes. More specifically, it revisits service designers’ capabilities in light of the new roles that have opened up in innovation processes on different scales. After years of being inadequately defined, the professional profile of service designers is now taking shape. Today private and public institutions recognize service designers as essential contributors to their innovation and development processes. What are the capabilities that characterize a service designer? These essential capabilities are what service designers should acquire in their education and can sell when looking for a job

    In-space operations for lunar and Mars space transfer vehicles

    Get PDF
    The objective of this paper is to discuss the in-space operations required to process the lunar and Mars mission vehicles envisioned for the Space Exploration Initiative (SEI). Recent studies, which have examined the degree to which on-orbit operations change as a function of the Earth-to-orbit (ETO) launch vehicle size, identified a common set of on-orbit vehicle processing tasks, and generated functional requirements for in-space processing nodes are summarized in this paper. Timelines for on-orbit processing of two different lunar transfer vehicles (LTV's) were developed to compare a 'current practice,' labor-intensive EVA approach to ones utilizing telerobotics and advanced automation. LTV aerobrake concepts ranging from simple deployment to considerable assembly are compared. Similar timelines for the on-orbit processing of a nuclear Mars transfer vehicle (MTV) are also presented. Aerobrakes can be processed in a timely manner and should not be ruled out for SEI missions. The 'tall pole' time interval for on-orbit vehicle initial processing is the delivery of elements to orbit, not the processing tasks

    Cleavage of E-Cadherin by Matrix Metalloproteinase-7 Promotes Cellular Proliferation in Nontransformed Cell Lines via Activation of RhoA

    Get PDF
    Perturbations in cell-cell contact machinery occur frequently in epithelial cancers and result in increased cancer cell migration and invasion. Previously, we demonstrated that MMP-7, a protease implicated in mammary and intestinal tumor growth, can process the adherens junction component E-cadherin. This observation leads us to test whether MMP-7 processing of E-cadherin could directly impact cell proliferation in nontransformed epithelial cell lines (MDCK and C57MG). Our goal was to investigate the possibility that MMP-7 produced by cancer cells may have effects on adjacent normal epithelium. Here, we show that MMP-7 processing of E-cadherin mediates, (1) loss of cell-cell contact, (2) increased cell migration, (3) a loss of epithelial cell polarization and (4) increased cell proliferation via RhoA activation. These data demonstrate that MMP-7 promotes epithelial cell proliferation via the processing of E-cadherin and provide insights into the molecular mechanisms that govern epithelial cell growth

    Co-creation of Value in IT Service Processes Using Semantic MediaWiki

    Full text link
    Abstract: Enterprises are substituting their own IT-Systems by services provided by external providers. This provisioning of services may be done in an industrialized way, separating the service provider from the consumer. However, using industrialized services diminishes the capability to differentiate from competitors. To counter this, collaborative service processes based on the co-creation of value between service providers and prosumers are of huge importance. The approach presented shows how the co-creation of value in IT-service processes can profit from social software, using the example of the Semantic MediaWiki

    Expanding understanding of service exchange and value co-creation: A social construction approach

    Get PDF
    According to service-dominant logic (S-D logic), all providers are service providers, and service is the fundamental basis of exchange. Value is co-created with customers and assessed on the basis of value-in-context. However, the extensive literature on S-D logic could benefit from paying explicit attention to the fact that both service exchange and value co-creation are influenced by social forces. The aim of this study is to expand understanding of service exchange and value co-creation by complementing these central aspects of S-D logic with key concepts from social construction theories (social structures, social systems, roles, positions, interactions, and reproduction of social structures). The study develops and describes a new framework for understanding how the concepts of service exchange and value co-creation are affected by recognizing that they are embedded in social systems. The study contends that value should be understood as value-in-social-context and that value is a social construction. Value co-creation is shaped by social forces, is reproduced in social structures, and can be asymmetric for the actors involved. Service exchanges are dynamic, and actors learn and change their roles within dynamic service systems

    Overview of the LADEE Ultraviolet-visible Spectrometer: Design, Performance and Planned Operations

    Get PDF
    The Lunar Atmosphere and Dust Environment Explorer (LADEE) is an orbital lunar science mission currently under development to address the goals of the 2003 National Research Council decadal survey, the Lunar Exploration Analysis Group Roadmap, and the "Scientific Context for Exploration of the Moon" (SCEM) report, and has been recommended for execution by the 2011 Planetary Missions Decadal Survey. The mission s focus is to study the pristine state of the lunar atmosphere and dust environment prior to possible lunar exploration activities by countries, including the United States, China, India, and Japan, among others. Activity on the lunar surface has the potential of altering the tenuous lunar atmosphere, but changing the type and concentration of gases in the atmosphere. Before these activities occur it is important to make measurements of the current lunar atmosphere in its unmodified state. LADEE will determine the composition of the lunar atmosphere and investigate the processes that control its distribution and variability, including sources, sinks, and surface interactions. It will monitor variations in known gases, such as sodium, potassium, argon and helium, and will search for other, as-yet-undetected gases of both lunar and extra-lunar origin. LADEE will also determine whether dust is present in the lunar exosphere, and reveal the processes that contribute to its sources and variability. Launch is planned for August, 2013
    corecore