Search results
1 – 10 of 722Natalie Antal, Bruce Kingma, Duncan Moore and Deborah Streeter
In 2004 and 2007, the Kauffman Foundation awarded 18 universities and colleges $3–5 million dollars each to develop radiant model entrepreneurship education programs and…
Abstract
In 2004 and 2007, the Kauffman Foundation awarded 18 universities and colleges $3–5 million dollars each to develop radiant model entrepreneurship education programs and campus-wide entrepreneurial ecosystems. Grant recipients were required to have a senior level administrator to oversee the program who reported to the Provost, President, or Chancellor. Award recipients included Syracuse University (2007) and the University of Rochester (2004). Cornell was not a Kauffman campus. This chapter explores three case studies in the radiant model of university-wide entrepreneurship education as deployed at Cornell University, The University of Rochester, and Syracuse University. The authors examine the history, accelerators, and challenges of the radiant model of university-wide entrepreneurship education.
Details
Keywords
Timothy T Diller, Mengqi Yuan, David L. Bourell and Joseph J. Beaman
The purpose of this paper is to analyze the bulk energy transport processes in the build chamber environment before and during laser sintering (LS) to provide a basis for…
Abstract
Purpose
The purpose of this paper is to analyze the bulk energy transport processes in the build chamber environment before and during laser sintering (LS) to provide a basis for effective and accurate thermal control for the LS process. This leads to improved mechanical properties and geometrical tolerances for LS products and may be applied to optimize operation cycle times for the LS process.
Design/methodology/approach
Computational models with two levels of complexity were built to explore the heat transfer mechanisms in the LS process. In a one-dimensional model (1D), the powder performed as a semi-infinite solid and heater flux to the powder surface was modeled with a heater control law. A two-dimensional (2D) fluid/solid finite element model of the build chamber and powder bins provided insight into the thermal processes in the build chamber.
Findings
Numerical 1D simulations were verified with measurements from sensors embedded in the build chamber powder bed. Using a 2D model, computed powder surface temperatures during the warm up and build phases were verified with an infrared camera. Convective currents in the build chamber and non-uniformities in the distribution of temperature over the radiant heater surface were found to be substantial contributors to non-uniformities in the powder bed surface temperature.
Research limitations/implications
Limited heat sources were analyzed. No three-dimensional model was built. Assumptions to decrease the part bed temperature difference were not tested.
Originality/value
These simulation and experimental results may be used to enhance thermal control and operation efficiency during the LS process and to improve LS product mechanical properties.
Details
Keywords
This chapter reports on a study of the benefits of the Integrated Education in Agricultural Entrepreneurship (IEAE). IEAE substantially covers the transfer of knowledge, skills…
Abstract
This chapter reports on a study of the benefits of the Integrated Education in Agricultural Entrepreneurship (IEAE). IEAE substantially covers the transfer of knowledge, skills, and attitudes that will allow in each farmer-learner to plan, to launch, and to manage his/her own business and it should be approached from leadership perspective and as a life-long learning process. Entrepreneurship constitutes an important factor that determines the level of economic growth, competitiveness, employment, and social prosperity of a small country such as Greece (Spanoudaki, 2008). For purposes of this chapter agricultural entrepreneurship is defined as an effort developed individually or collectively for the exploitation of resources that the individual or the team allocates for the production of useful agricultural products, services, or goods connected with the production of agricultural products and their distribution in the market, satisfying market needs. According to the Global Entrepreneurship Monitor (Bosma & Levie, 2010), entrepreneurship is conceptualized as each effort for building a new business or a new activity, such as the free profession, where the creation of a new business, or the extension of an existing one, is done by an individual or by teams of individuals, from public institutions or from established private businesses.
María Cristina Sánchez and J.R. Mahan
The purpose of this paper is to present the results obtained from numerical models of radiant energy exchange in instruments typically used to measure various characteristics of…
Abstract
Purpose
The purpose of this paper is to present the results obtained from numerical models of radiant energy exchange in instruments typically used to measure various characteristics of the Earth's ocean‐atmosphere system.
Design/methodology/approach
Numerical experiments were designed and performed in a statistical environment, based on the Monte Carlo ray‐trace (MCRT) method, developed to model thermal and optical systems. Results from the derived theoretical equations were then compared to the results from the numerical experiments.
Findings
A rigorous statistical protocol is defined and demonstrated for establishing the uncertainty and related confidence interval in results obtained from MCRT models of radiant exchange.
Research limitations/implications
The methodology developed in this paper should be adapted to predict the uncertainty of more comprehensive parameters such as the total radiative heat transfer.
Practical implications
Results can be used to estimate the number of energy bundles necessary to be traced per surface element in a MCRT model to obtain a desired relative error.
Originality/value
This paper offers a new methodology to predict the uncertainty of parameters in high‐level modeling and analysis of instruments that accumulate the long‐term database required to correlate observed trends with human activity and natural phenomena. The value of this paper lies in the interest in understanding the climatological role of the Earth's radiative energy budget.
Details
Keywords
Xuehui Wang, Tiannian Zhou, Qinpei Chen and Jian Wang
This study aims to investigate the controlling mechanisms of ambient oxygen and pressure on piloted ignition of solid combustibles under external…
Abstract
Purpose
This study aims to investigate the controlling mechanisms of ambient oxygen and pressure on piloted ignition of solid combustibles under external radiant heating.
Design/methodology/approach
The numerical simulation method was used to model the influence of ambient oxygen concentration on the piloted ignition of a thermally irradiated solid sample in reduced pressure atmospheres. The solid phase decomposition and gas phase kinetics were solved simultaneously.
Findings
It was determined that the elevated oxygen atmospheres resulted in a higher flame temperature and a thicker temperature profile over the solid surface. Also, increasing oxygen and reducing pressure had a similar effect in the decrease of the ignition delay time. The shorter ignition time in reduced pressure was mainly because of the decreasing of convective heat losses from the heated solid. As oxygen was reduced, however, ignition occurred later and with a greater mass loss rate because more volatiles of solid fuel at transient ignition were required to sustain a complete reaction under an oxygen-poor condition.
Research limitations/implications
The results need to be verified with experiments.
Practical implications
The results could be applied for design and assessment of fire-fighting and fire prevention strategies in reduced pressure atmosphere.
Originality/value
This paper shows the effect mechanism of ambient oxygen and pressure on piloted ignition of solid combustibles.
Details
Keywords
Bhimsen Rajkumarsingh, Robert T. F. Ah King and Khalid Adam Joomun
The performance of thermal comfort utilising machine learning and its acceptability by students and other users at the Professor Sir Edouard Lim Fat Engineering Tower at the…
Abstract
The performance of thermal comfort utilising machine learning and its acceptability by students and other users at the Professor Sir Edouard Lim Fat Engineering Tower at the University of Mauritius are evaluated in this study. Students and building occupants were asked to fill out surveys on-site as data was gathered from sensors throughout the structure. The Thermal Sensation Vote (TSV) and other important data were collected through the surveys, including the effect of wind on thermal comfort. An adaptive model incorporating solar and wind effects was evaluated using multiple linear regression techniques and RStudio. Three models were used to evaluate thermal comfort, including the adaptive one. Numerous models were compared and evaluated in order to select the best one. It was found that the adaptive model (Model 1) was deemed to be the best model for its application. It was also found that Fanger's PMV/PPD (Model 2) was a very good approach to determining thermal comfort. Through thorough analysis, it was concluded that the range of air temperature and wind speed for thermal comfort was 25.830°C–28.0°C and 0.26 m/s to 0.42 m/s, respectively. In order for cities to remain secure, resilient and sustainable, it will be important to manage thermal comfort and reduce populations' exposure to heat stress (SDG 11). The achievement of income and productivity goals will be hampered if measures to protect populations from heat stress are not taken (SDG 8). Thermal regulation is also necessary for the provision of numerous health services (SDG 3).
Details
Keywords
J.G. Marakis, J. Chamiço, G. Brenner and F. Durst
Notes that, in a full‐scale application of the Monte Carlo method for combined heat transfer analysis, problems usually arise from the large computing requirements. Here the…
Abstract
Notes that, in a full‐scale application of the Monte Carlo method for combined heat transfer analysis, problems usually arise from the large computing requirements. Here the method to overcome this difficulty is the parallel execution of the Monte Carlo method in a distributed computing environment. Addresses the problem of determination of the temperature field formed under the assumption of radiative equilibrium in an enclosure idealizing an industrial furnace. The medium contained in this enclosure absorbs, emits and scatters anisotropically thermal radiation. Discusses two topics in detail: first, the efficiency of the parallelization of the developed code, and second, the influence of the scattering behavior of the medium. The adopted parallelization method for the first topic is the decomposition of the statistical sample and its subsequent distribution among the available processors. The measured high efficiencies showed that this method is particularly suited to the target architecture of this study, which is a dedicated network of workstations supporting the message passing paradigm. For the second topic, the results showed that taking into account the isotropic scattering, as opposed to neglecting the scattering, has a pronounced impact on the temperature distribution inside the enclosure. In contrast, the consideration of the sharply forward scattering, that is characteristic of all the real combustion particles, leaves the predicted temperature field almost undistinguishable from the absorbing/emitting case.
Details
Keywords
L. Allançon, B. Porterie, R. Saurel and J.C. Loraud
A numerical analysis is given for the prediction of unsteady,two‐dimensional fluid flow induced by a heat and mass source in aninitially closed cavity which is vented when the…
Abstract
A numerical analysis is given for the prediction of unsteady, two‐dimensional fluid flow induced by a heat and mass source in an initially closed cavity which is vented when the internal overpressure reaches a certain level. A modified ICE technique is used for solving the Navier–Stokes equations governing a compressible flow at a low Mach number and high temperature. Particular attention is focused on the treatment of the boundary conditions on the vent surface. This has been treated by an original procedure using the resolution of a Riemann problem. The configuration investigated may be viewed as a test problem which allows simulation of the ventilation and cooling of such cavities. The injection of hot gases is found to play a key role on the temperature field in the enclosure, whereas the vent seems to produce a distortion of the dynamic flow‐field only. When the injection of hot gases is stopped, the enclosure heat transfer is strongly influenced by the vent. A comparison with the results obtained when the radiative heat transfer between the walls of the enclosure is considered, indicate that radiation dominates the heat transfer in the enclosure and alters the flow patterns significantly.
Details
Keywords
Floriberta Binarti, Pranowo Pranowo, Chandra Aditya and Andreas Matzarakis
This study aims to compare the local climate characteristics of Angkor Wat, Borobudur and Prambanan parks and determine effective strategies for mitigating thermal conditions that…
Abstract
Purpose
This study aims to compare the local climate characteristics of Angkor Wat, Borobudur and Prambanan parks and determine effective strategies for mitigating thermal conditions that could suit Borobudur and Angkor Wat.
Design/methodology/approach
The study employed local climate zone (LCZ) indicators and ten-year historical climate data to identify similarities and differences in local climate characteristics. Satellite imagery processing was used to create maps of LCZ indicators. Meanwhile, microclimate models were used to analyze sky view factors and wind permeability.
Findings
The study found that the three tropical large-scale archaeological parks have low albedo, a medium vegetation index and high impervious surface index. However, various morphological characteristics, aerodynamic properties and differences in temple stone area and altitude enlarge the air temperature range.
Practical implications
Based on the similarities and differences in local climate, the study formulated mitigation strategies to preserve the sustainability of ancient temples and reduce visitors' heat stress.
Originality/value
The local climate characterization of tropical archaeological parks adds to the number of LCZs. Knowledge of the local climate characteristics of tropical archaeological parks can be the basis for improving thermal conditions.
Details
Keywords
This paper aims to explore stakeholder involvement in, and expectation of, entrepreneurship education in UK higher education institutions (HEIs).
Abstract
Purpose
This paper aims to explore stakeholder involvement in, and expectation of, entrepreneurship education in UK higher education institutions (HEIs).
Design/methodology/approach
Longitudinal telephone surveys were conducted annually over an eight‐year period (2000 to 2007) to document and analyse 336 respondents' involvement in, and expectation of, entrepreneurship education in UK HEIs.
Findings
The results indicate that stakeholder involvement in entrepreneurship education is explicit, widespread and linked to ongoing educational developments that have radically transformed management structures and accountability at all levels of the UK educational system. Stakeholders' expectations are equally complex and varied, reflecting a heterogeneous range of individual, group and community needs.
Practical implications
The findings provide valuable insights into entrepreneurship education for students, university staff, policy makers and other stakeholders. Government could use the results of this research study to ensure that relevant policies and initiatives reach the targeted sector in a focused and cost‐efficient manner.
Originality/value
This study provides an original and empirically rigorous insight into stakeholder involvement in, and expectation of, entrepreneurship education in UK HEIs. It provides valuable longitudinal data for a wide range of stakeholders involved in entrepreneurship education in the UK.
Details