460 research outputs found
Abolishing Exclusionary Zoning: A Natural Policy Alliance for Environmentalists and Affordable Housing Advocates
Exclusionary zoning limits residential development over large areas, and even entire cities or towns, to single-family housing on large lots. Exclusionary zoning is unfair to people and families of modest means (many of whom are members of racial or ethnic minorities) because it sharply limits where they can live and thus their access to jobs, education, and a good quality of life. For these reasons, exclusionary zoning was found to violate the New Jersey Constitution in the Mount Laurel case. But exclusionary zoning is also an environmental problem because it is a primary ingredient of the accelerating pace of urban and suburban sprawl. As a consequence, it is a major contributor to increased air and water pollution and habitat fragmentation. The Oregon planning program demonstrates how the abolition of exclusionary zoning promotes a more equitable range of housing choice in suburbs and simultaneously reduces environmental degradation associated with low-density urbanization
Design of multivariable feedback control systems via spectral assignment
Applied research in the area of spectral assignment in multivariable systems is reported. A frequency domain technique for determining the set of all stabilizing controllers for a single feedback loop multivariable system is described. It is shown that decoupling and tracking are achievable using this procedure. The technique is illustrated with a simple example
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In vivo and in vitro assessment of mirtazapine pharmacokinetics in cats with liver disease.
BackgroundLiver disease (LD) prolongs mirtazapine half-life in humans, but it is unknown if this occurs in cats with LD and healthy cats.Hypothesis/objectivesTo determine pharmacokinetics of administered orally mirtazapine in vivo and in vitro (liver microsomes) in cats with LD and healthy cats.AnimalsEleven LD and 11 age-matched control cats.MethodsCase-control study. Serum was obtained 1 and 4 hours (22 cats) and 24 hours (14 cats) after oral administration of 1.88 mg mirtazapine. Mirtazapine concentrations were measured by liquid chromatography with tandem mass spectrometry. Drug exposure and half-life were predicted using limited sampling modeling and estimated using noncompartmental methods. in vitro mirtazapine pharmacokinetics were assessed using liver microsomes from 3 LD cats and 4 cats without LD.ResultsThere was a significant difference in time to maximum serum concentration between LD cats and control cats (median [range]: 4 [1-4] hours versus 1 [1-4] hours; P = .03). The calculated half-life of LD cats was significantly prolonged compared to controls (median [range]: 13.8 [7.9-61.4] hours versus 7.4 [6.7-9.1] hours; P < .002). Mirtazapine half-life was correlated with ALT (P = .002; r = .76), ALP (P < .0001; r = .89), and total bilirubin (P = .0008; r = .81). The rate of loss of mirtazapine was significantly different between microsomes of LD cats (-0.0022 min-1 , CI: -0.0050 to 0.00054 min-1 ) and cats without LD (0.01849 min-1 , CI: -0.025 to -0.012 min-1 ; P = .002).Conclusions and clinical importanceCats with LD might require less frequent administration of mirtazapine than normal cats
Seeing Through the Noise: Seismic Reflection Profiling in Urban Areas
Studies for urban hazard or resource assessment often take place in densely populated areas characterized by considerable cultural noise. These site conditions can severely compromise seismic reflection data quality. We have collected vibroseis and hammer (weight drop) seismic reflection data in a range of geologic conditions to image stratigraphy and structures in the upper one km along regional highways, city streets,and power line access roads. In addition to the challenges of safety and outreach, acquisition efforts along busy streets and highways often encounter poor receiver coupling and large-amplitude coherent noise from traffic and power lines. Although higher quality seismic reflection data may be obtained by simply choosing alternate sites with less cultural noise, modifications to the acquisition and processing step scan minimize the effects of cultural noise and poor coupling where profiling is most relevant. Flagging crews, flyers and public announcements assist with outreach and safety concerns, and the local news media are often enthusiastic about publicizing geologic studies. Recording long-record vibroseis data reduces the effects of noise by itself,but data quality can be further optimized by recording uncorrelated,unstacked data and applying precorrelation amplitude adjustments and filters. Recording individual hammer shots likewise allows gains or mutes to normalize or remove traffic noise prior to vertical stacking. Large numbers of receiver channels allow attenuation of random noise and velocity filtering to remove coherent noise. Because ground roll and normal moveout (NMO) corrections minimize near-surface coverage, asymmetric source-receiver geometry allows for additional near-surface fold while muting large amplitude ground rolland NMO stretch. Source and geophone coupling on road shoulder scan degrade signal quality due to variable materials and topography,but these problems are often addressed with static corrections. Our experience is that high-quality seismic data can be obtained in noisy urban areas, but many recorded channels and a careful attention to acquisition and processing procedures can significantly improve the results
Perceived Barriers to Entry into Self-employment in Khayelitsha, South Africa: Crime, Risk, and Start-up Capital Dominate Profit Concerns
In South Africa, the broad unemployment rate for Africans has remained near or above forty percent for most of the last ten years. One critical reason is the relatively low level of employment in small-scale entrepreneurial work. This paper explores the factors that constrain individuals from engaging in self-employment activities in a large township in Cape Town. Crime is perceived to be the dominant hindrance to entering the micro-enterprise sector. A number of other hindrances, including capital constraints, transportation costs, and community jealousy, are on par or surpass concerns over profitability or government regulation. These findings are robust to a series of alternative ranking scheme
Tsunamigenic Splay Faults Imply a Long‐Term Asperity in Southern Prince William Sound, Alaska
Coseismic slip partitioning and uplift over multiple earthquake cycles is critical to understanding upper‐plate fault development. Bathymetric and seismic reflection data from the 1964 Mw9.2 Great Alaska earthquake rupture area reveal sea floor scarps along the tsunamigenic Patton Bay/Cape Cleare/Middleton Island fault system. The faults splay from a megathrust where duplexing and underplating produced rapid exhumation. Trenchward of the duplex region, the faults produce a complex deformation pattern from oblique, south‐directed shortening at the Yakutat‐Pacific plate boundary. Spatial and temporal fault patterns suggest that Holocene megathrust earthquakes had similar relative motions and thus similar tsunami sources as in 1964. Tsunamis during future earthquakes will likely produce similar run‐up patterns and travel times. Splay fault surface expressions thus relate to plate boundary conditions, indicating millennial‐scale persistence of this asperity. We suggest structure of the subducted slab directly influences splay fault and tsunami generation landward of the frontal subduction zone prism
Estimasi Beban Puncak Energi Listrik Pada Sistem Sulutgo Menggunakan Artificial Neural Network Dan Metode Moving Average
Sulutgo interconnection system is the electrical energy suppliers for North Sulawesi and Gorontalo. Their role as the electrical energy supplier was complained by people in 2015, due to lack of electricity supply that lead to continuous rolling blackouts. Accordingly, it is important to identify the electrical peak load in Sulutgo system, so that the electrical necessity of the people can be properly fulfilled. The electrical peak load in the next 12 month is estimated using the backpropagation method artificial neural network and forecasting method moving average. The estimation was performed by using the last 24 month peak load data. Based on the results of both estimation, it is found the backpropagation method artificial neural network has fluctuated results while the forecasting method moving average gives stable results. The results of the estimation of peak load electricity using bacpropagation artificial neural network method for the next 12 month starting from July 2016 to June 2017 are 327.48, 353.99, 316.32, 316.66, 332.37, 329.79, 332.31, 356.21, 318.60, 349.56, 351.37, 362.04 MW. While the results of the estimation method using moving average forecasting for the same period are 325.68, 326.03, 326.39, 326.72, 327.25, 328.09, 327.94, 328.72, 329.94, 330.32, 327.65, 326.52 MW
Product descriptors for early product development : an interface between environmental experts and designers
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.Includes bibliographical references (p. 68-72).Sustainable development is not just about technological innovation, but rather about a radical shift in the way society thinks. The environmental effects of our choices and behavior must be internalized. In the context of product development, this internalization should occur in early product development under the guidance of an environmental expert. During early product design phases there may be numerous concepts with significant differences, detailed information is scarce, and decisions must be made quickly. The overhead in developing parametric life-cycle assessment (LCA) models for a diverse range of concepts, and the lack of detailed information make the integration of environmental expertise through traditional LCA models impractical. Therefore, a new approach was developed to incorporate analytically based environmental assessment in early design stages. Product descriptors are the communication interface between environmental experts and designers for this new model, called a learning surrogate LCA. Product descriptors are a set of keywords both understood by designers in relation to a preliminary product, and meaningful in an approximate environmental impact assessment of a product. This thesis develops a set of product concept descriptors for use in environmental assessment. The chosen descriptor set was measurable by designers in conceptual design, and produced reasonable results when used to predict environmental impacts using an approximate model. Tests within the DOME integrated modeling environment have shown it is possible to predict the life-cycle energy consumption of a product. There is also a basis for the method to be used in predicting solid material, greenhouse effect, ozone layer depletion, acidification, eutrophication, winter smog, and summer smog.by Julie L. Eisenhard.S.M
Megathrust Splay Faults at the Focus of the Prince William Sound Asperity, Alaska
[1] High-resolution sparker and crustal-scale air gun seismic reflection data, coupled with repeat bathymetric surveys, document a region of repeated coseismic uplift on the portion of the Alaska subduction zone that ruptured in 1964. This area defines the western limit of Prince William Sound. Differencing of vintage and modern bathymetric surveys shows that the region of greatest uplift related to the 1964 Great Alaska earthquake was focused along a series of subparallel faults beneath Prince William Sound and the adjacent Gulf of Alaska shelf. Bathymetric differencing indicates that 12 m of coseismic uplift occurred along two faults that reached the seafloor as submarine terraces on the Cape Cleare bank southwest of Montague Island. Sparker seismic reflection data provide cumulative Holocene slip estimates as high as 9 mm/yr along a series of splay thrust faults within both the inner wedge and transition zone of the accretionary prism. Crustal seismic data show that these megathrust splay faults root separately into the subduction zone décollement. Splay fault divergence from this megathrust correlates with changes in midcrustal seismic velocity and magnetic susceptibility values, best explained by duplexing of the subducted Yakutat terrane rocks above Pacific plate rocks along the trailing edge of the Yakutat terrane. Although each splay fault is capable of independent motion, we conclude that the identified splay faults rupture in a similar pattern during successive megathrust earthquakes and that the region of greatest seismic coupling has remained consistent throughout the Holocene
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