6,641 research outputs found

    The Co-evolution of Business Incubators and National Incubator Networks in Emerging Markets

    Get PDF
    The study proposes a three stage model of the development of business incubation practices in emerging markets. The model addresses the diffusion of incubation practices to new markets, the institutionalization of those practices and the co-evolution of incubators and national networks of incubation. The model is based on interviews conducted in Bolivia, Peru, Chile, Argentina, and Brazil. New incubators in emerging markets often face strong cultural norms and institutional impediments to helping entrepreneurs start new businesses. As incubation becomes better established in a country, incubators provide more advanced technical, legal and market-based advice. Networks of incubators form to share specialized services across many incubators, to allocate government funding to incubators, and to lobby for public and private support of innovation

    A viscoplastic constitutive theory for metal matrix composites at high temperature

    Get PDF
    A viscoplastic constitutive theory is presented for representing the high temperature deformation behavior of metal matrix composites. The point of view taken is a continuum one where the composite is considered a material in its own right, with its own properties that can be determined for the composite as a whole. It is assumed that a single preferential (fiber) direction is identifiable at each material point (continuum element) admitting the idealization of local transverse isotropy. A key ingredient is the specification of an experimental program for the complete determination of the material functions and parameters for characterizing a particular metal matrix composite. The parameters relating to the strength of anisotropy can be determined through tension/torsion tests on longitudinally and circumferentially reinforced thin walled tubes. Fundamental aspects of the theory are explored through a geometric interpretation of some basic features analogous to those of the classical theory of plasticity

    Public Perceptions of Wisconsin’s Pavements and Tradeoffs in Pavement Improvement

    Get PDF
    Findings are reported from Phase II of a three-phase pooled-fund project in Wisconsin, Iowa, and Minnesota to determine perceptions of drivers regarding pavement of rural two-lane highways. Among the survey topics were drivers\u27 trust in the state department of transportation (DOT), pavement improvement trade-offs, and pavement evaluation. Results of the Wisconsin portion of the survey data are the focus of this study. The survey questionnaire was based in part on Phase I focus groups conducted to gauge beliefs about pavements as well as the language describing ruts, tining, and other pavement characteristics. Phase II entailed a statewide telephone survey of at least 400 randomly selected drivers in each of the three states. Although the focus here is on Wisconsin results, survey responses across the three states were very consistent. Included in the findings discussed are perceptions of pavement and the state DOT and pavement improvement options relating to construction, travel time, and delays. Results disclose key public perceptions of priorities with regard to spending limited funds. Also discussed are statistically significant relationships providing additional insights into public perceptions and pavement improvement on rural two-lane highways

    Integrals of Periodic Functions

    Get PDF
    Computing integrals of powers of the sine function is a standard exercise in calculus. The authors show that the first integral is representative of the integral of any periodic function

    NASA's Space Launch System: Opportunities for Small Satellites to Deep Space Destinations

    Get PDF
    The first flight of NASA's new exploration-class launch vehicle, the Space Launch System (SLS), will test a myriad of systems designed to enable the next generation of deep space human spaceflight, while also providing the rare opportunity for 13 6U CubeSat-class payloads to be deployed in several locations along the flight path. The first mission of SLS and NASA's new Orion crew vehicle, Exploration Mission-1 (EM-1), will launch from upgraded facilities at Kennedy Space Center no earlier than fiscal year 2020. The initial Block 1 configuration for EM-1 will be capable of lofting at least 26 metric tons (t) of payload to the moon, with propulsion supplied by twin five-segment solid rocket boosters, four RS-25 engines and an Interim Cryogenic Propulsion Stage (ICPS). SLS will send Orion into a distant retrograde lunar orbit, paving the way for future missions to cislunar space and eventually Mars. The multidisciplinary small satellites for EM-1 derive from NASA research, as well as from international partners, industry and academia. Research subjects for the various smallsats include the moon, sun and an asteroid. Science objectives vary from characterizing the effects of radiation on living organisms (yeast) to landing the smallest spacecraft yet on the moon to supporting space weather research. Some of the payloads are technology demonstrations that will pave the way for more ambitious future missions that will be deployed by the more powerful SLS Block 1B configuration

    Numerical Solutions of the Complete Navier-Stokes Equations

    Get PDF
    This report details the development of a new two-equation turbulence closure model based on the exact turbulent kinetic energy k and the variance of vorticity, zeta. The model, which is applicable to three dimensional flowfields, employs one set of model constants and does not use damping or wall functions, or geometric factors

    Space Launch System Artemis I CubeSats: SmallSat Vanguards of Exploration, Science and Technology

    Get PDF
    When NASA’s Space Launch System (SLS) rocket launches in 2021 with the Orion crew vehicle, it will lay the foundation for NASA’s goal of landing the first woman and the next man on the Moon as part of the Artemis program. This first flight—Artemis I—will also mark a milestone for smallsats. Thirteen 6U CubeSats are manifested on the Artemis I flight, the first fleet of CubeSats carried as a rideshare opportunity to deep space. (NASA’s first CubeSats to deep space, the twin Mars Cube One [MarCO] spacecraft, were an integral part of the InSight Mars lander mission). The Artemis I CubeSat manifest represents a diverse collection of smallsats performing an array of science missions and technology demonstrations. Payloads from NASA, international partners, academia and industry will execute a variety of experiments. Several smallsats will perform lunar-focused missions that may return data that addresses Strategic Knowledge Gaps (SKGs) in the agency’s lunar exploration program. Indeed, the Artemis I CubeSats will be in the vanguard of the agency’s 21st-century lunar program. The Artemis I missions will produce data to support space radiation awareness, crewed landings and in-siture source utilization, helping to support a sustained human lunar presence. Several of the Artemis I CubeSats are demonstrating new technologies, including propulsion capabilities. Among the Artemis I CubeSats are three selected through NASA’s Cube Quest Challenge, part of the Centennial Challenges program. These three missions will compete for prize money while meeting specific technical development goals. Payloads from the Japanese and Italian space agencies provide an early opportunity for international involvement in the Artemis program. Student involvement in almost half of the payloads allow STEM engagement with NASA’s Artemis program. The SLS Block 1 vehicle for the Artemis I flight is manufactured with several elements delivered to Kennedy Space Center (KSC) and being prepared for stacking and integration. The new-development of the program, the 212-footcore stage with its four RS-25 engines installed is currently at Stennis Space Center (SSC) for “green run” testing. Following the green run test campaign, the stage will ship to KSC, where it will be integrated with the rest of the vehicle, including the upper stage adapter, where the Artemis I smallsats will be housed

    Using Excel to Make Strategic Managerial Decisions

    Get PDF
    This case involves actual data from a student managed café that serves as a learning laboratory for a college of business. The student team that manages the café has never had access to precise data from a point of sale system until this semester. However, once they downloaded the raw data from the cash register they were unable to make sense of the data. This was in part due to the data entry errors in recording transactions as well as operational issues such as multiple managers entering new items into the register when there is already an existing code for the item in the Point of Sale (POS) database. To clean up the data and develop actionable spreadsheet based results, the managers decide to call in a team of information systems consultants to help them clean the dataset while not losing important data. To address the operating concerns of the managers, the consultants analyze the sales data for a number of questions whose answers can be used to improve how the café operates. By using Excel to analyze the data, consultants will be able to address the managerial decisions faced by the café team

    NASA's Space Launch System: Enabling Exploration and Discovery

    Get PDF
    As NASA's new Space Launch System (SLS) launch vehicle continues to mature toward its first flight and beyond, so too do the agency's plans for utilization of the rocket. Substantial progress has been made toward the production of the vehicle for the first flight of SLS - an initial "Block 1" configuration capable of delivering more than 70 metric tons (t) to Low Earth Orbit (LEO). That vehicle will be used for an uncrewed integrated test flight, propelling NASA's Orion spacecraft into lunar orbit before it returns safely to Earth. Flight hardware for that launch is being manufactured at facilities around the United States, and, in the case of Orion's service module, beyond. At the same time, production has already begun on the vehicle for the second SLS flight, a more powerful Block 1B configuration capable of delivering more than 105 t to LEO. This configuration will be used for crewed launches of Orion, sending astronauts farther into space than anyone has previously ventured. The 1B configuration will introduce an Exploration Upper Stage, capable of both ascent and in-space propulsion, as well as a Universal Stage Adapter - a payload bay allowing the flight of exploration hardware with Orion - and unprecedentedly large payload fairings that will enable currently impossible spacecraft and mission profiles on uncrewed launches. The Block 1B vehicle will also expand on the initial configuration's ability to deploy CubeSat secondary payloads, creating new opportunities for low-cost access to deep space. Development work is also underway on future upgrades to SLS, which will culminate in about a decade in the Block 2 configuration, capable of delivering 130 t to LEO via the addition of advanced boosters. As the first SLS draws closer to launch, NASA continues to refine plans for the human deep-space exploration it will enable. Planning currently focuses on use of the vehicle to assemble a Deep Space Gateway, which would comprise a habitat in the lunar vicinity allowing astronauts to gain experience living and working in deep space, a testbed for new systems and capabilities needed for exploration beyond, and a departure point for NASA and partners to send missions to other destinations. Assembly of the Gateway would be followed by a Deep Space Transport, which would be a vehicle capable of carrying astronauts farther into our solar system and eventually to Mars. This paper will give an overview of SLS' current status and its capabilities, and discuss current utilization planning

    NASA's Space Launch System: An Evolving Capability for Exploration

    Get PDF
    Designed to enable human space exploration missions, including eventually landings on Mars, NASA's Space Launch System (SLS) represents a unique launch capability with a wide range of utilization opportunities, from delivering habitation systems into the lunar vicinity to high-energy transits through the outer solar system. The vehicle will be able to deliver greater mass to orbit than any contemporary launch vehicle. SLS will also be able to carry larger payload fairings than any contemporary launch vehicle, and will offer opportunities for co-manifested and secondary payloads
    • …
    corecore