186 research outputs found

    The Foundation Payout Puzzle

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    This paper examines public policy toward American philanthropic foundations. We find that the major regulation bearing on foundations -- a mandated minimum endowment payout rate -- has had the effect of repressing foundation giving. Interviews with foundation trustees and presidents point to a number of significant obstacles to proper conceptualization of the payout decision in foundations. In the face of these obstacles, our survey of foundation payout behavior over 25 years reveals that most foundations simply pay out the mandated minimum amount each year, regardless of other relevant considerations. We argue that the minimum rate has gone from being a floor when it was enacted decades ago to a ceiling today. The paper concludes with an exploration of how the payout policy could usefully be reformed.This publication is Hauser Center Working Paper No. 9. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

    Study on the Crystal Structure and Microstructure Evolution of Shock-processed Titanium Powder

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    Titanium powder was rapidly solidified by using shock-wave consolidation technique. The critical parameters were controlled by intrumented detonics and pin-oscillography. The compacted specimens were investigated for crystal structure and microstructural strengthening by using standard diagnostic techniques. The density of the final product was found to be greater than 96% of the theoretical value. X-ray diffraction pattern reveals intact crystalline structure without the presence of any undesired phases. The particle size reduction indicated by XRD was supported by laser diffraction based particle size analyzer. Results from energy dispersive spectroscopy ruled out the possibility of any segregation within the compacts. Scanning electron microscopy showed crack-free, voids-free, melt-free, fracture-less compacts of titanium with a unidirectional dendrite orientation without any grain-growth

    Numerical analysis of film boiling around horizontal cylindrical surfaces

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    Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.Stability of vapor film over a horizontal heater drags attention due to its wide spread applications in nuclear reactors, metal processing, manufacturing and chemical refineries. Existence of vapor film around the heater can cause advantages as well as disadvantages for various applications in industry and daily life. Hence understanding the film formation and its subsequent release in the form of bubble are dealt carefully by researchers in heat transfer community. Critical vapor thickness and average heat flux are the essential parameters which govern the release of vapor mass in the form of isolated bubbles from the surface. Experimental evidences have been reported in order to find out film dynamics for some specific fluids. However understanding it from the fundamental physics is still due and becomes a major challenge for heat transfer community. In this paper, numerical analysis of the film boiling heat transfer on a horizontal cylinder is presented to determine the effect of superheating on the heat transfer coefficient and film thickness in a pool. Findings from the present study will develop knowhow about the film formation and its role in enhancing the boiling heat transfer coefficient.am201

    Understanding factors behind IoT privacy -- A user's perspective on RF sensors

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    While IoT sensors in physical spaces have provided utility and comfort in our lives, their instrumentation in private and personal spaces has led to growing concerns regarding privacy. The existing notion behind IoT privacy is that the sensors whose data can easily be understood and interpreted by humans (such as cameras) are more privacy-invasive than sensors that are not human-understandable, such as RF (radio-frequency) sensors. However, given recent advancements in machine learning, we can not only make sensitive inferences on RF data but also translate between modalities. Thus, the existing notions of privacy for IoT sensors need to be revisited. In this paper, our goal is to understand what factors affect the privacy notions of a non-expert user (someone who is not well-versed in privacy concepts). To this regard, we conduct an online study of 162 participants from the USA to find out what factors affect the privacy perception of a user regarding an RF-based device or a sensor. Our findings show that a user's perception of privacy not only depends upon the data collected by the sensor but also on the inferences that can be made on that data, familiarity with the device and its form factor as well as the control a user has over the device design and its data policies. When the data collected by the sensor is not human-interpretable, it is the inferences that can be made on the data and not the data itself that users care about when making informed decisions regarding device privacy

    Challenges of Second-hand Smoke: Are We Asking the Right Questions?

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    Second-hand tobacco smoke as defined by WHO is the smoke emitted by a smoker or released from a burnt cigarette or any tobacco product. It is highly prevalent all over the globe but its serious health implications are often neglected by the public and the scientific community alike. Second-hand smoke has everlasting impact on all the body’s major organs, especially among the vulnerable population of children, pregnant ladies, people with chronic diseases and senior citizens. Although India started its war against this menace earlier than other counties, all its efforts remain bootless as its approach and implementation have a wide range of lacunae. This review aims to give a big picture of second-hand smoke, highlighting its pathophysiological changes in the body, socioeconomic impact, various strategies, and the gap that prevents these strategies from finding a favorable result in India. It becomes all the more important to reduce its impact owing to the increase in prevalence among youth reducing their vitality, derailing the society and the nation. It is recommended that the health authorities approach this health problem with utmost seriousness as a laid-back approach could welcome this silent killer’s known and unknown repercussions

    Metal-organic frameworks-derived titanium dioxide-carbon nanocomposite for supercapacitor applications

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    The pyrolysis of metal-organic frameworks (MOFs) to derive porous nanocarbons and metal oxides has attracted scientific attention due to the advantageous properties of the final products (eg, high surface areas). In the present research, MIL-125 (MIL = Materials of Institute Lavoisier, a Ti-based MOF) has been subjected to a single-step pyrolysis treatment in argon atmosphere. The combination of uniformly linked titanium metal cluster and oxygen-enriched organic linker has acted as a template to yield a titanium dioxide (TiO2)-carbon nanocomposite. The TiO2 nanoparticles infused in carbon skeleton structure (TiO2/C) has been investigated as an electrode material for supercapacitor applications. TiO2/C electrodes have delivered an excellent electrochemical performance, for example, in terms of charging-discharging efficiency. Two equally weighed TiO2/C electrodes have been used to assemble a solid-state symmetrical supercapacitor (SC) device, containing a gel electrolyte (poly vinyl alcohol in 1 M H2SO4). The above device has delivered a high value of energy density (43.5 Wh/kg) and an excellent power output of 0.865 kW/kg. The symmetrical SC could retain almost 95% of its initial capacitance even after 2000 charging-discharging cycles. The electrochemical performance of the TiO2/C SC was better than most MOF-based SCs reported previously. Such performance is attributed to the synergistic combination of electrically conducting MOF-derived carbon and redox active TiO2 nanocrystals with a large specific surface area
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