5,724 research outputs found

    A new dry biomedical electrode

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    Electronic circuitry contains new operational amplifier which incorporates monolithic super-gain transistors. Electrode does not provide voltage amplification; instead, it acts as current amplifier to make it possible to pick up electrical potentials from surface of highly resistant dry skin

    Carbon Free Boston: Waste Technical Report

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    Part of a series of reports that includes: Carbon Free Boston: Summary Report; Carbon Free Boston: Social Equity Report; Carbon Free Boston: Technical Summary; Carbon Free Boston: Buildings Technical Report; Carbon Free Boston: Transportation Technical Report; Carbon Free Boston: Energy Technical Report; Carbon Free Boston: Offsets Technical Report; Available at http://sites.bu.edu/cfb/OVERVIEW: For many people, their most perceptible interaction with their environmental footprint is through the waste that they generate. On a daily basis people have numerous opportunities to decide whether to recycle, compost or throwaway. In many cases, such options may not be present or apparent. Even when such options are available, many lack the knowledge of how to correctly dispose of their waste, leading to contamination of valuable recycling or compost streams. Once collected, people give little thought to how their waste is treated. For Boston’s waste, plastic in the disposal stream acts becomes a fossil fuel used to generate electricity. Organics in the waste stream have the potential to be used to generate valuable renewable energy, while metals and electronics can be recycled to offset virgin materials. However, challenges in global recycling markets are burdening municipalities, which are experiencing higher costs to maintain their recycling. The disposal of solid waste and wastewater both account for a large and visible anthropogenic impact on human health and the environment. In terms of climate change, landfilling of solid waste and wastewater treatment generated emissions of 131.5 Mt CO2e in 2016 or about two percent of total United States GHG emissions that year. The combustion of solid waste contributed an additional 11.0 Mt CO2e, over half of which (5.9 Mt CO2e) is attributable to the combustion of plastic [1]. In Massachusetts, the GHG emissions from landfills (0.4 Mt CO2e), waste combustion (1.2 Mt CO2e), and wastewater (0.5 Mt CO2e) accounted for about 2.7 percent of the state’s gross GHG emissions in 2014 [2]. The City of Boston has begun exploring pathways to Zero Waste, a goal that seeks to systematically redesign our waste management system that can simultaneously lead to a drastic reduction in emissions from waste. The easiest way to achieve zero waste is to not generate it in the first place. This can start at the source with the decision whether or not to consume a product. This is the intent behind banning disposable items such as plastic bags that have more sustainable substitutes. When consumption occurs, products must be designed in such a way that their lifecycle impacts and waste footprint are considered. This includes making durable products, limiting the use of packaging or using organic packaging materials, taking back goods at the end of their life, and designing products to ensure compatibility with recycling systems. When reducing waste is unavoidable, efforts to increase recycling and organics diversion becomes essential for achieving zero waste. [TRUNCATED]Published versio

    A Bayesian spatio-temporal model of panel design data: airborne particle number concentration in Brisbane, Australia

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    This paper outlines a methodology for semi-parametric spatio-temporal modelling of data which is dense in time but sparse in space, obtained from a split panel design, the most feasible approach to covering space and time with limited equipment. The data are hourly averaged particle number concentration (PNC) and were collected, as part of the Ultrafine Particles from Transport Emissions and Child Health (UPTECH) project. Two weeks of continuous measurements were taken at each of a number of government primary schools in the Brisbane Metropolitan Area. The monitoring equipment was taken to each school sequentially. The school data are augmented by data from long term monitoring stations at three locations in Brisbane, Australia. Fitting the model helps describe the spatial and temporal variability at a subset of the UPTECH schools and the long-term monitoring sites. The temporal variation is modelled hierarchically with penalised random walk terms, one common to all sites and a term accounting for the remaining temporal trend at each site. Parameter estimates and their uncertainty are computed in a computationally efficient approximate Bayesian inference environment, R-INLA. The temporal part of the model explains daily and weekly cycles in PNC at the schools, which can be used to estimate the exposure of school children to ultrafine particles (UFPs) emitted by vehicles. At each school and long-term monitoring site, peaks in PNC can be attributed to the morning and afternoon rush hour traffic and new particle formation events. The spatial component of the model describes the school to school variation in mean PNC at each school and within each school ground. It is shown how the spatial model can be expanded to identify spatial patterns at the city scale with the inclusion of more spatial locations.Comment: Draft of this paper presented at ISBA 2012 as poster, part of UPTECH projec

    Carbon Free Boston: Transportation Technical Report

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    Part of a series of reports that includes: Carbon Free Boston: Summary Report; Carbon Free Boston: Social Equity Report; Carbon Free Boston: Technical Summary; Carbon Free Boston: Buildings Technical Report; Carbon Free Boston: Waste Technical Report; Carbon Free Boston: Energy Technical Report; Carbon Free Boston: Offsets Technical ReportOVERVIEW: Transportation connects Boston’s workers, residents and tourists to their livelihoods, health care, education, recreation, culture, and other aspects of life quality. In cities, transit access is a critical factor determining upward mobility. Yet many urban transportation systems, including Boston’s, underserve some populations along one or more of those dimensions. Boston has the opportunity and means to expand mobility access to all residents, and at the same time reduce GHG emissions from transportation. This requires the transformation of the automobile-centric system that is fueled predominantly by gasoline and diesel fuel. The near elimination of fossil fuels—combined with more transit, walking, and biking—will curtail air pollution and crashes, and dramatically reduce the public health impact of transportation. The City embarks on this transition from a position of strength. Boston is consistently ranked as one of the most walkable and bikeable cities in the nation, and one in three commuters already take public transportation. There are three general strategies to reaching a carbon-neutral transportation system: • Shift trips out of automobiles to transit, biking, and walking;1 • Reduce automobile trips via land use planning that encourages denser development and affordable housing in transit-rich neighborhoods; • Shift most automobiles, trucks, buses, and trains to zero-GHG electricity. Even with Boston’s strong transit foundation, a carbon-neutral transportation system requires a wholesale change in Boston’s transportation culture. Success depends on the intelligent adoption of new technologies, influencing behavior with strong, equitable, and clearly articulated planning and investment, and effective collaboration with state and regional partners.Published versio

    Do actions occur inside the body?

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    The paper offers a critical examination of Jennifer Hornsby's view that actions are internal to the body. It focuses on three of Hornsby's central claims: (P) many actions are bodily movements (in a special sense of the word “movement”) (Q) all actions are tryings; and (R) all actions occur inside the body. It is argued, contra Hornsby, that we may accept (P) and (Q) without accepting also the implausible (R). Two arguments are first offered in favour of the thesis (Contrary-R): that no actions occur inside the body. Three of Hornsby's arguments in favour of R are then examined. It is argued that we need to make a distinction between the causes and the causings of bodily movements (in the ordinary sense of the word “movement”) and that actions ought to be identified with the latter rather than the former. This distinction is then used to show how Hornsby's arguments for (R) may be resisted

    Heterogeneity in the growth hormone pituitary gland system of rats and humans: Implications to microgravity based research

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    The cell separation techniques of velocity sedimentation, flow cytometry and continuous flow electrophoresis were used to obtain enriched populations of growth hormone (GH) cells. The goal was to isolate a GH cell subpopulation which releases GH molecules which are very high in biological activity, it was important to use a method which was effective in processing large numbers of cells over a short time span. The techniques based on sedimentation are limited by cell density overlaps and streaming. While flow cytometry is useful in the analytical mode for objectively establishing cell purity, the numbers of cells which can be processed in the sort mode are so small as to make this approach ineffective in terms of the long term goals. It was shown that continuous flow electrophoresis systems (CFES) can separate GH cells from other cell types on the basis of differences in surface charge. The bioreactive producers appear to be more electrophoretically mobile than the low producers. Current ground based CFES efforts are hampered by cell clumping in low ionic strength buffers and poor cell recoveries from the CFES device

    Nonlinear 3-D simulation of high-intensity focused ultrasound therapy in the Kidney

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    Kidney cancer is a severe disease which can be treated non-invasively using high-intensity focused ultrasound (HIFU) therapy. However, tissue in front of the transducer and the deep location of kidney can cause significant losses to the efficiency of the treatment. The effect of attenuation, refraction and reflection due to different tissue types on HIFU therapy of the kidney was studied using a nonlinear ultrasound simulation model. The geometry of the tissue was derived from a computed tomography (CT) dataset of a patient which had been segmented for water, bone, soft tissue, fat and kidney. The combined effect of inhomogeneous attenuation and soundspeed was found to result in an 11.0 dB drop in spatial peak-temporal average (SPTA) intensity in the kidney compared to pure water. The simulation without refraction effects showed a 6.3 dB decrease indicating that both attenuation and refraction contribute to the loss in focal intensity. The losses due to reflections at soft tissue interfaces were less than 0.1 dB. Focal point shifting due to refraction effects resulted in -1.3, 2.6 and 1.3 mm displacements in x-, y- and z-directions respectively. Furthermore, focal point splitting into several smaller subvolumes was observed. The total volume of the secondary focal points was approximately 46% of the largest primary focal point. This could potentially lead to undesired heating outside the target location and longer therapy times

    The Chromium Content of Cement and Its Significance in Cement Dermatitis1

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    Entropic effects on the Size Evolution of Cluster Structure

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    We show that the vibrational entropy can play a crucial role in determining the equilibrium structure of clusters by constructing structural phase diagrams showing how the structure depends upon both size and temperature. These phase diagrams are obtained for example rare gas and metal clusters.Comment: 5 pages, 3 figure
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