4,782 research outputs found
Examining Income Convergence in Southern United States
County-level data for 11 southern states were used to examine income convergence between 1980 and 2000. Ordinary least squares regression of logarithmic difference on average per capita income in 1980 and 2000 indicated conditional income convergence over the 20-year period. The estimated rate of income convergence was 3.82% per year. This convergence varied across the region based on the initial and changed conditions of population density, African-American population, employment, education, age structure, and travel time to work.Financial Economics,
Income Convergence and Growth in Alabama: Evidence from Sub-county Level Data
1980 and 2000 Census Block Group (CBG) data were used to examine income convergence in all Alabama counties vis-à-vis Alabama’s Black Belt and Northwest regions. Though all three models demonstrated conditional income convergence, CBGs with smaller initial populations, smaller changes in African-American or dependent age populations had higher income changes.Alabama, African-Americans, Black Belt, Census Block Groups, Income Convergence, Community/Rural/Urban Development, Resource /Energy Economics and Policy,
Cultural logics of emotion: Implications for understanding torture and its sequelae
This paper explores the significance of cultural variations in emotion for the meaning and impact of torture, focusing on the dynamics of shame, humiliation, and powerlessness. Forms of physical and psychological pain and suffering share some common neurobiological pathways and regulatory systems that are influenced by social and cultural factors. All forms of torture follow an affective logic rooted both in human biology and in local social and cultural meanings of experience. Understanding the impact of specific forms of torture on individuals requires knowledge of their learning histories, and of the personal and cultural meanings of specific kinds of violence. Exploring cultural meanings requires attention to over-arching discourse, embodied practices, and everyday engagements with an ecosocial environment. Restitution, treatment and recovery can then be guided by knowledge of cultural meanings, dynamics, and strategies for coping with catastrophic threats, injury, humiliation, helplessness and loss
Modeling stormwater management at the city district level in response to changes in land use and low impact development
Mitigating the impact of increasing impervious surfaces on stormwater runoff by low impact development (LID) is currently being widely promoted at site and local scales. In turn, the series of distributed LID implementations may produce cumulative effects and benefit the stormwater management at larger regional scales. However, the potential of multiple LID implementations to mitigate the broad-scale impacts of urban stormwater is not yet fully understood, particularly among different design strategies to reduce directly connected impervious areas (DCIA). In this study, the hydrological responses of stormwater runoff characteristics to four different land use conversion scenarios at the city scale were explored using GIS-based Stormwater Management Model (SWMM). Model simulation results confirmed the effectiveness of LID controls; however, they also indicated that even with the most beneficial scenarios hydrological performance of developed areas was still not yet up to the pre-development level, especially with pronounced changes from pervious to impervious land
Apparatus and Method for Triboelectrostatic Separation
A triboelectrostatic separation apparatus includes a separator with an inlet, a separation chamber, first and second electrodes, a variable voltage source for applying respective positive and negative voltage potentials to the electrodes, a pair of separated particle outlets and a curtain gas flow generation system. The curtain gas flow generation system includes a source of curtain gas at positive pressure, a metering valve for matching curtain gas flow velocity to particle flow velocity and flow straighteners for eliminating eddy currents. A method for separating electrostatically charged particles is also described
Electrostatic Particle Separation System, Apparatus, and Related Method
An electrostatic separation apparatus or system is provided for separating a particle mixture into two constituent species. The system includes a distributor for differentially tribocharging the particle species forming the mixture and supplying the charged mixture to a plurality of electrostatic separation cells. Each cell includes at least one separator having an inlet, a separation chamber having an electric field zone for drawing selected charged particles from the particle mixture, a collector, and a transition outlet. The length of the electric field zone is selectively adjustable for varying the charged particle drawing action. A curtain gas flow introduced into the separation chamber carries the selected charged particles drawn from the particle mixture in the electric field zone to the collector. Flow vanes or straighteners are provided for both the particle mixture flow and the curtain gas flow to reduce turbulence in the separation chamber and improve separation efficiency. The collector includes a discharge outlet for discharging the selected charged particles to a first collection bin. The transition outlet receives the remaining particle flow and delivers it to a second collection bin for recovery or to a second separator to collect any remaining selected charged particles. The transition outlet reforms the flow to create turbulence to further tribocharge the particles prior to entering the second separator. A related method of particle separation is also disclosed
Triboelectric Separator with Mixing Chamber and Pre-Separator
A triboelectrostatic separation apparatus includes a mixing chamber having opposed first and second charging ports, a separator having a separation chamber, first and second electrodes, and a variable voltage source for applying respective positive and negative voltage potentials to the electrodes. First and second particle streams are delivered through the first and second charging ports resulting in the impingement of the particle streams upon each other within the mixing chamber, thus enhancing the electrostatic charging of the particles contained within the particle streams. The apparatus may also include a pre-separator having a pre-separation chamber, a charged particle collection chamber and a plurality of feed passageways providing fluid communication between the pre-separation and the charged particle collection chambers. As a result of imparting electrical charges upon the particles, an electric field exists within the pre-separator allowing certain particles to be repelled/drawn through the passageways into the charged particle collection chamber. A method for separating electrostatically charged particles is also described
Particle Separation System Using Parallel Multistage Electrostatic Separators
An electrostatic separation apparatus includes of a plurality of separators is provided for separating a particle mixture into two constituent species. Each separator includes one and preferably a plurality of modular separation stages. Each stage of the separator includes a pair of separation subchambers each having an electric field zone for drawing selected charged particles from the particle mixture. A curtain gas flow is provided for each subchamber to entrain and carry the selected charged particles drawn from the particle mixture in the electric field zone to a collector associated with each subchamber for recovery. The inlets for the particle mixture and curtain gas flows are adapted to straighten and smooth the respective flows to reduce turbulence in the separation subchambers and improve separation efficiency. The particle flow remaining after the first separation stage passes through an outlet to a second stage, a recycle line, or if further separation is deemed unnecessary, to a collection device for recovery. The apparatus may include a plurality of single or multistage separators arranged in parallel such that simultaneous operation is possible. Further, the apparatus may be included as part of an overall separation system
Adoption of Conservation-Tillage Practices in Cotton Production
Replaced with revised version of paper 10/23/07.conservation tillage, cotton, genetically modified seed, herbicide-resistant cotton, stacked-gene cotton, simultaneous logit model, single-equation logit model, technology adoption, Crop Production/Industries,
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