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Sample records for metropolitan atlanta ga

  1. Modeling the Effect of Onsite Wastewater Treatment Systems on Nitrate Load Using SWAT in an Urban Watershed of Metropolitan Atlanta, GA

    Science.gov (United States)

    Onsite Wastewater Treatment Systems (OWTSs) can be a source of nitrate (NO3-) contamination in both surface and ground waters as a result of failing or high density systems. In metropolitan Atlanta, more than 26% of homes are on OWTS and this percentage is expected to increase wi...

  2. 40 CFR 81.45 - Metropolitan Atlanta Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.45 Section 81.45 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.45 Metropolitan Atlanta Intrastate Air Quality Control Region. The Metropolitan Atlanta Intrastate Air Quality Control Region (Georgia) has been revised to consist of the...

  3. Water crisis: the metropolitan Atlanta, Georgia, regional water supply conflict

    KAUST Repository

    Missimer, Thomas M.

    2014-07-01

    Many large population centres are currently facing considerable difficulties with planning issues to secure future water supplies, as a result of water allocation and environmental issues, litigation, and political dogma. A classic case occurs in the metropolitan Atlanta area, which is a rapidly growing, large population centre that relies solely on surface water for supply. Lake Lanier currently supplies about 70% of the water demand and has been involved in a protracted legal dispute for more than two decades. Drought and environmental management of the reservoir combined to create a water shortage which nearly caused a disaster to the region in 2007 (only about 35 days of water supply was in reserve). While the region has made progress in controlling water demand by implementing a conservation plan, per capita use projections are still very high (at 511 L/day in 2035). Both non-potable reuse and indirect reuse of treated wastewater are contained in the most current water supply plan with up to 380,000 m3/day of wastewater treated using advanced wastewater treatment (nutrient removal) to be discharged into Lake Lanier. The water supply plan, however, includes no additional or new supply sources and has deleted any reference to the use of seawater desalination or other potential water sources which would provide diversification, thereby relying solely on the Coosa and Chattahoochee river reservoirs for the future. © 2014 IWA Publishing.

  4. The mortality profile of black Seventh-Day Adventists residing in metropolitan Atlanta: a pilot study.

    Science.gov (United States)

    Murphy, F G; Blumenthal, D S; Dickson-Smith, J; Peay, R P

    1990-08-01

    Mortality information was gathered for 110 Black Seventh-day Adventist members of seven churches in Metropolitan Atlanta, Georgia during the period 1980-87. Seventy-seven percent of the deaths were due to cardiovascular diseases; 8 percent due to cancer, the second leading cause of death. The cancer rate is extremely low in comparison to the proportion of deaths due to cardiovascular diseases. Subsequent research on this population will take into consideration lifestyle factors which could contribute to this finding.

  5. Environmental Public Health Tracking: Health and Environment Linked for Information Exchange-Atlanta (HEXIX-Atlanta: A cooperative Program Between CDC and NASA for Development of an Environmental Public Health Tracking Network in the Atlanta Metropolitan Area

    Science.gov (United States)

    Quattrochi, Dale A.; Niskar, Amanda Sue

    2005-01-01

    The Centers for Disease Control and Prevention (CDC) is coordinating HELIX- Atlanta to provide information regarding the five-county Metropolitan Atlanta Area (Clayton, Cobb, DeKalb, Fulton, and Gwinett) via a network of integrated environmental monitoring and public health data systems so that all sectors can take action to prevent and control environmentally related health effects. The HELIX-Atlanta Network is a tool to access interoperable information systems with optional information technology linkage functionality driven by scientific rationale. HELIX-Atlanta is a collaborative effort with local, state, federal, and academic partners, including the NASA Marshall Space Flight Center. The HELIX-Atlanta Partners identified the following HELIX-Atlanta initial focus areas: childhood lead poisoning, short-latency cancers, developmental disabilities, birth defects, vital records, respiratory health, age of housing, remote sensing data, and environmental monitoring, HELIX-Atlanta Partners identified and evaluated information systems containing information on the above focus areas. The information system evaluations resulted in recommendations for what resources would be needed to interoperate selected information systems in compliance with the CDC Public Health Information Network (PHIN). This presentation will discuss the collaborative process of building a network that links health and environment data for information exchange, including NASA remote sensing data, for use in HELIX-Atlanta.

  6. Risk Factors for HIV Transmission and Barriers to HIV Disclosure: Metropolitan Atlanta Youth Perspectives

    OpenAIRE

    Camacho-Gonzalez, Andres F.; Wallins, Amy; Toledo, Lauren; Murray, Ashley; Gaul, Zaneta; Sutton, Madeline Y.; Gillespie, Scott; Leong, Traci; Graves, Chanda; Chakraborty, Rana

    2016-01-01

    Youth carry the highest incidence of HIV infection in the United States. Understanding adolescent and young adult (AYA) perspectives on HIV transmission risk is important for targeted HIV prevention. We conducted a mixed methods study with HIV-infected and uninfected youth, ages 18–24 years, from Atlanta, GA. We provided self-administered surveys to HIV-infected and HIV-uninfected AYAs to identify risk factors for HIV acquisition. By means of computer-assisted thematic analyses, we examined t...

  7. Modeling the Effects of Onsite Wastewater Treatment Systems on Nitrate Loads Using SWAT in an Urban Watershed of Metropolitan Atlanta.

    Science.gov (United States)

    Hoghooghi, Nahal; Radcliffe, David E; Habteselassie, Mussie Y; Jeong, Jaehak

    2017-05-01

    Onsite wastewater treatment systems (OWTSs) can be a source of nitrogen (N) pollution in both surface and ground waters. In metropolitan Atlanta, GA, >26% of homes are on OWTSs. In a previous article, we used the Soil Water Assessment Tool to model the effect of OWTSs on stream flow in the Big Haynes Creek Watershed in metropolitan Atlanta. The objective of this study was to estimate the effect of OWTSs, including failing systems, on nitrate as N (NO-N) load in the same watershed. Big Haynes Creek has a drainage area of 44 km with mainly urban land use (67%), and most of the homes use OWTSs. A USGS gauge station where stream flow was measured daily and NO-N concentrations were measured monthly was used as the outlet. The model was simulated for 12 yr. Overall, the model showed satisfactory daily stream flow and NO-N loads with Nash-Sutcliffe coefficients of 0.62 and 0.58 for the calibration period and 0.67 and 0.33 for the validation period at the outlet of the Big Haynes Watershed. Onsite wastewater treatment systems caused an average increase in NO-N load of 23% at the watershed scale and 29% at the outlet of a subbasin with the highest density of OWTSs. Failing OWTSs were estimated to be 1% of the total systems and did not have a large impact on stream flow or NO-N load. The NO-N load was 74% of the total N load in the watershed, indicating the important effect of OWTSs on stream loads in this urban watershed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. Joseph Jacobs: Apprentice to Crawford W. Long in Athens, GA; Pharmacist and Retailer of Soda Fountain Beverages in Atlanta, GA.

    Science.gov (United States)

    Haridas, Rajesh P

    2018-01-01

    In the 1870s, Joseph Jacobs was employed as an apprentice in the Longs and Billups pharmacy in Athens, GA. Jacobs later established a chain of pharmacies in Atlanta, GA. Coca-Cola was first sold to the public on May 8, 1886, at Jacobs' Pharmacy in the Five Points district of Atlanta, GA. The soda fountain in Jacobs' Pharmacy was owned by Willis E. Venable, who was related to James M. Venable, the first patient etherized by Crawford Long in Jefferson, GA. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Environmental Public Health Surveillance for Exposure to Respiratory Health Hazards: A Joint NASA/CDC Project to Use Remote Sensing Data for Estimating Airborne Particulate Matter Over the Atlanta, Georgia Metropolitan Area

    Science.gov (United States)

    Quattrochi, Dale A.; Al-Hamdan, Mohammad; Estes, Maurice; Crosson, William

    2007-01-01

    As part of the National Environmental Public Health Tracking Network (EPHTN) the National Center for Environmental Health (NCEH) at the Centers for Disease Control and Prevention (CDC) is leading a project called Health and Environment Linked for Information Exchange (HELiX-Atlanta). The goal of developing the National Environmental Public Health Tracking Network is to improve the health of communities. Currently, few systems exist at the state or national level to concurrently track many of the exposures and health effects that might be associated with environmental hazards. An additional challenge is estimating exposure to environmental hazards such as particulate matter whose aerodynamic diameter is less than or equal to 2.5 micrometers (PM2.5). HELIX-Atlanta's goal is to examine the feasibility of building an integrated electronic health and environmental data network in five counties of Metropolitan Atlanta, GA. NASA Marshall Space Flight Center (NASA/MSFC) is collaborating with CDC to combine NASA earth science satellite observations related to air quality and environmental monitoring data to model surface estimates of PM2.5 concentrations that can be linked with clinic visits for asthma. While use of the Air Quality System (AQS) PM2.5 data alone could meet HELIX-Atlanta specifications, there are only five AQS sites in the Atlanta area, thus the spatial coverage is not ideal. We are using NASA Moderate Resolution Imaging Spectroradiometer (MODIS) satellite Aerosol Optical Depth (AOD) data for estimating daily ground level PM2.5 at 10 km resolution over the metropolitan Atlanta area supplementing the AQS ground observations and filling their spatial and temporal gaps.

  10. Racial disparities in travel time to radiotherapy facilities in the Atlanta metropolitan area.

    Science.gov (United States)

    Peipins, Lucy A; Graham, Shannon; Young, Randall; Lewis, Brian; Flanagan, Barry

    2013-07-01

    Low-income women with breast cancer who rely on public transportation may have difficulty in completing recommended radiation therapy due to inadequate access to radiation facilities. Using a geographic information system (GIS) and network analysis we quantified spatial accessibility to radiation treatment facilities in the Atlanta, Georgia metropolitan area. We built a transportation network model that included all bus and rail routes and stops, system transfers and walk and wait times experienced by public transportation system travelers. We also built a private transportation network to model travel times by automobile. We calculated travel times to radiation therapy facilities via public and private transportation from a population-weighted center of each census tract located within the study area. We broadly grouped the tracts by low, medium and high household access to a private vehicle and by race. Facility service areas were created using the network model to map the extent of areal coverage at specified travel times (30, 45 and 60 min) for both public and private modes of transportation. The median public transportation travel time to the nearest radiotherapy facility was 56 min vs. approximately 8 min by private vehicle. We found that majority black census tracts had longer public transportation travel times than white tracts across all categories of vehicle access and that 39% of women in the study area had longer than 1 h of public transportation travel time to the nearest facility. In addition, service area analyses identified locations where the travel time barriers are the greatest. Spatial inaccessibility, especially for women who must use public transportation, is one of the barriers they face in receiving optimal treatment. Published by Elsevier Ltd.

  11. Risk Factors for HIV Transmission and Barriers to HIV Disclosure: Metropolitan Atlanta Youth Perspectives.

    Science.gov (United States)

    Camacho-Gonzalez, Andres F; Wallins, Amy; Toledo, Lauren; Murray, Ashley; Gaul, Zaneta; Sutton, Madeline Y; Gillespie, Scott; Leong, Traci; Graves, Chanda; Chakraborty, Rana

    2016-01-01

    Youth carry the highest incidence of HIV infection in the United States. Understanding adolescent and young adult (AYA) perspectives on HIV transmission risk is important for targeted HIV prevention. We conducted a mixed methods study with HIV-infected and uninfected youth, ages 18-24 years, from Atlanta, GA. We provided self-administered surveys to HIV-infected and HIV-uninfected AYAs to identify risk factors for HIV acquisition. By means of computer-assisted thematic analyses, we examined transcribed focus group responses on HIV education, contributors to HIV transmission, and pre-sex HIV status disclosure. The 68 participants had the following characteristics: mean age 21.5 years (standard deviation: 1.8 years), 85% male, 90% black, 68% HIV-infected. HIV risk behaviors included the perception of condomless sex (Likert scale mean: 8.0) and transactional sex (88% of participants); no differences were noted by HIV status. Qualitative analyses revealed two main themes: (1) HIV risk factors among AYAs, and (2) barriers to discussing HIV status before sex. Participants felt the use of social media, need for immediate gratification, and lack of concern about HIV disease were risk factors for AYAs. Discussing HIV status with sex partners was uncommon. Key reasons included: fear of rejection, lack of confidentiality, discussion was unnecessary in temporary relationships, and disclosure negatively affecting the mood. HIV prevention strategies for AYAs should include improving condom use frequency and HIV disclosure skills, responsible utilization of social media, and education addressing HIV prevention including the risks of transactional sex.

  12. Fight or Flight? Immigration, Competition, and Language Assistance Resources in Metropolitan Atlanta

    Science.gov (United States)

    Tarasawa, Beth

    2013-01-01

    As the Latino/a immigrant population increases, racial conflict historically understood in terms of Black and White in the U.S. South has expanded to include new contestants in metro-Atlanta public schools. By examining market and sociological competition theoretical perspectives, this study investigates how language assistance resource…

  13. Racial/ethnic variations in the prevalence of selected major birth defects, metropolitan Atlanta, 1994-2005.

    Science.gov (United States)

    Kucik, James E; Alverson, Clinton J; Gilboa, Suzanne M; Correa, Adolfo

    2012-01-01

    Birth defects are the leading cause of infant mortality and are responsible for substantial child and adult morbidity. Documenting the variation in prevalence of birth defects among racial/ethnic subpopulations is critical for assessing possible variations in diagnosis, case ascertainment, or risk factors among such groups. We used data from the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects registry with active case ascertainment. We estimated the racial/ethnic variation in prevalence of 46 selected major birth defects among live births, stillbirths, and pregnancy terminations at >20 weeks gestation among mothers residing in the five central counties of metropolitan Atlanta between 1994 and 2005, adjusting for infant sex, maternal age, gravidity, and socioeconomic status (SES). We also explored SES as a potential effect measure modifier. Compared with births to non-Hispanic white women, births to non-Hispanic black women had a significantly higher prevalence of five birth defects and a significantly lower prevalence of 10 birth defects, while births to Hispanic women had a significantly higher prevalence of four birth defects and a significantly lower prevalence of six birth defects. The racial/ethnic disparities in the prevalence of some defects varied by SES, but no clear pattern emerged. Racial/ethnic disparities were suggested in 57% of included birth defects. Disparities in the prevalence of birth defects may result from different underlying genetic susceptibilities; exposure to risk factors; or variability in case diagnosis, ascertainment, or reporting among the subpopulations examined. Policies that improve early diagnosis of birth defects could reduce associated morbidity and mortality.

  14. Urban expansion simulation and the spatio-temporal changes of ecosystem services, a case study in Atlanta Metropolitan area, USA.

    Science.gov (United States)

    Sun, Xiao; Crittenden, John C; Li, Feng; Lu, Zhongming; Dou, Xiaolin

    2018-05-01

    Urban expansion can lead to land use changes and, hence, threatens the ecosystems. Understanding the effects of urbanization on ecosystem services (ESs) can provide scientific guidance for land use planning and the protection of ESs. We established a framework to assess the spatial distributions of ESs based on land use changes in the Atlanta Metropolitan area (AMA) from 1985 to 2012. A new comprehensive ecosystem service (CES) index was developed to reflect the comprehensive level of ESs. Associated with the influential factors, we simulated the business as usual scenario in 2030. Four alternative scenarios, including more compact growth (MCG), riparian vegetation buffer (RVB), soil conservation (SC), and combined development (CD) scenarios were developed to explore the optimal land use strategies which can enhance the ESs. The results showed that forest and wetland had the greatest decreases, while low and high intensity built-up lands had the greatest increases. The values of CES and most of ESs decreased significantly due to the sprawling expansion of built-up land. The scenario analysis revealed that the CD scenario performs best in CES value, while it performs the worst in food supply. Compared with the RVB and SC scenarios, MCG scenario is a more optimal land use strategy to enhance the ESs without at the expense of food supply. To integrate multiple ESs into land use planning and decision making, corresponding land management policies and ecological engineering measures should be implemented to enhance: (1) the water yield and water purification in urban core counties, (2) the carbon storage, habitat quality, and recreational opportunity in counties around the core area, and (3) the soil conservation and food supply in surrounding suburban counties. The land use strategies and ecological engineering measures in this study can provide references for enhancing the ESs in the AMA and other metropolitan areas. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Characterization of CCN and IN activity of bacterial isolates collected in Atlanta, GA

    Science.gov (United States)

    Purdue, Sara; Waters, Samantha; Karthikeyan, Smruthi; Konstantinidis, Kostas; Nenes, Athanasios

    2016-04-01

    Characterization of CCN activity of bacteria, other than a few select types such as Pseudomonas syringae, is limited, especially when looked at in conjunction with corresponding IN activity. The link between these two points is especially important for bacteria as those that have high CCN activity are likely to form an aqueous phase required for immersion freezing. Given the high ice nucleation temperature of bacterial cells, especially in immersion mode, it is important to characterize the CCN and IN activity of many different bacterial strains. To this effect, we developed a droplet freezing assay (DFA) which consists of an aluminum cold plate, cooled by a continuous flow of an ethylene glycol-water mixture, in order to observe immersion freezing of the collected bacteria. Here, we present the initial results on the CCN and IN activities of bacterial samples we have collected in Atlanta, GA. Bacterial strains were collected and isolated from rainwater samples taken from different storms throughout the year. We then characterized the CCN activity of each strain using a DMT Continuous Flow Streamwise Thermal Gradient CCN Counter by exposing the aerosolized bacteria to supersaturations ranging from 0.05% to 0.6%. Additionally, using our new DFA, we characterized the IN activity of each bacterial strain at temperatures ranging from -20oC to 0oC. The combined CCN and IN activity gives us valuable information on how some uncharacterized bacteria contribute to warm and mixed-phase cloud formation in the atmosphere.

  16. 78 FR 76810 - Information Collection; Environmental Justice and the Urban Forest in Atlanta, GA

    Science.gov (United States)

    2013-12-19

    ... should be addressed to Cassandra Johnson Gaither, Forestry Sciences Lab, 320 Green St., Athens, GA 30602... public may inspect comments received at Forestry Sciences Lab, 320 Green St., Athens, GA 30602 during... Type of Request: New Abstract: This information collection records data on the attitude and engagement...

  17. Trends in cytogenetic testing and identification of chromosomal abnormalities among pregnancies and children with birth defects, metropolitan Atlanta, 1968-2005.

    Science.gov (United States)

    Jackson, Jodi M; Crider, Krista S; Rasmussen, Sonja A; Cragan, Janet D; Olney, Richard S

    2012-01-01

    The purpose of this study was to examine changes in the use of cytogenetic testing and identification of chromosomal abnormalities among pregnancies and children with birth defects. Utilizing data from 1968 to 2005 from the Metropolitan Atlanta Congenital Defects Program, we analyzed trends in the frequency and timing (prenatal or postnatal) of cytogenetic testing and the prevalence of recognized chromosome abnormalities among pregnancies and children with birth defects (n = 51,424). Cytogenetic testing of pregnancies and children with birth defects increased from 7.2% in 1968 to 25.0% in 2005, as did the identification of chromosomal abnormalities (2.2% in 1968 to 6.8% in 2005). The use of prenatal cytogenetic testing decreased from 1996 to 2005 among women aged ≥35 years. Identification of chromosomal abnormalities in pregnancies and children with birth defects increased from 1968 to 2005, possibly due to increased testing, improved diagnostic techniques, or increasing maternal age. The decline in prenatal cytogenetic testing observed among mothers aged ≥35 years may be related to the availability of improved prenatal screening techniques, resulting in a reduction in the utilization of invasive diagnostic tests. Published 2011 Wiley Periodicals, Inc. This article is a U.S. Government work and is in the public domain in the USA.

  18. Custodial Homes, Therapeutic Homes, and Parental Acceptance: Parental Experiences of Autism in Kerala, India and Atlanta, GA USA.

    Science.gov (United States)

    Sarrett, Jennifer C

    2015-06-01

    The home is a critical place to learn about cultural values of childhood disability, including autism and intellectual disabilities. The current article describes how the introduction of autism into a home and the availability of intervention options change the structure and meaning of a home and reflect parental acceptance of a child's autistic traits. Using ethnographic data from Kerala, India and Atlanta, GA USA, a description of two types of homes are developed: the custodial home, which is primarily focused on caring for basic needs, and the therapeutic home, which is focused on changing a child's autistic traits. The type of home environment is respondent to cultural practices of child rearing in the home and influences daily activities, management, and care in the home. Further, these homes differ in parental acceptance of their autistic children's disabilities, which is critical to understand when engaging in international work related to autism and intellectual disability. It is proposed that parental acceptance can be fostered through the use of neurodiverse notions that encourage autism acceptance.

  19. Trends in the prevalence of autism spectrum disorder, cerebral palsy, hearing loss, intellectual disability, and vision impairment, metropolitan atlanta, 1991-2010.

    Directory of Open Access Journals (Sweden)

    Kim Van Naarden Braun

    Full Text Available This study examined the prevalence and characteristics of autism spectrum disorder (ASD, cerebral palsy (CP, hearing loss (HL, intellectual disability (ID, and vision impairment (VI over a 15-20 year time period, with specific focus on concurrent changes in ASD and ID prevalence. We used data from a population-based developmental disabilities surveillance program for 8-year-olds in metropolitan Atlanta. From 1991-2010, prevalence estimates of ID and HL were stable with slight increases in VI prevalence. CP prevalence was constant from 1993-2010. The average annual increase in ASD prevalence was 9.3% per year from 1996-2010, with a 269% increase from 4.2 per 1,000 in 1996 to 15.5 per 1,000 in 2010. From 2000-2010, the prevalence of ID without ASD was stable; during the same time, the prevalence of ASD with and without co-occurring ID increased by an average of 6.6% and 9.6% per year, respectively. ASD prevalence increases were found among both males and females, and among nearly all racial/ethnic subgroups and levels of intellectual ability. Average annual prevalence estimates from 1991-2010 underscore the significant community resources needed to provide early intervention and ongoing supports for children with ID (13.0 per 1,000, CP, (3.5 per 1,000, HL (1.4 per 1,000 and VI (1.3 in 1,000, with a growing urgency for children with ASD.

  20. Advancing Residential Retrofits in Atlanta

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Roderick K [ORNL; Kim, Eyu-Jin [Southface Energy Institute; Roberts, Sydney [Southface Energy Institute; Stephenson, Robert [Southface Energy Institute

    2012-07-01

    This report will summarize the home energy improvements performed in the Atlanta, GA area. In total, nine homes were retrofitted with eight of the homes having predicted source energy savings of approximately 30% or greater based on simulated energy consumption.

  1. Influence of septic systems on stream base flow in the Apalachicola-Chattahoochee-Flint River Basin near Metropolitan Atlanta, Georgia, 2012

    Science.gov (United States)

    Clarke, John S.; Painter, Jaime A.

    2014-01-01

    Septic systems were identified at 241,733 locations in a 2,539-square-mile (mi2) study area that includes all or parts of 12 counties in the Metropolitan Atlanta, Georgia, area. Septic system percolation may locally be an important component of streamflow in small drainage basins where it augments natural groundwater recharge, especially during extreme low-flow conditions. The amount of groundwater reaching streams depends on how much is intercepted by plants or infiltrates to deeper parts of the groundwater system that flows beyond a basin divide and does not discharge into streams within a basin. The potential maximum percolation from septic systems in the study area is 62 cubic feet per second (ft3/s), of which 52 ft3/s is in the Chattahoochee River Basin and 10 ft3/s is in the Flint River Basin. These maximum percolation rates represent 0.4 to 5.7 percent of daily mean streamflow during the 2011–12 period at the farthest downstream gaging site (station 02338000) on the Chattahoochee River, and 0.5 to 179 percent of daily mean streamflow at the farthest downstream gaging site on the Flint River (02344350). To determine the difference in base flow between basins having different septic system densities, hydrograph separation analysis was completed using daily mean streamflow data at streamgaging stations at Level Creek (site 02334578), with a drainage basin having relatively high septic system density of 101 systems per square mile, and Woodall Creek (site 02336313), with a drainage basin having relatively low septic system density of 18 systems per square mile. Results indicated that base-flow yield during 2011–12 was higher at the Level Creek site, with a median of 0.47 cubic feet per second per square mile ([ft3/s]/mi2), compared to a median of 0.16 (ft3/s)/mi2, at the Woodall Creek site. At the less urbanized Level Creek site, there are 515 septic systems with a daily maximum percolation rate of 0.14 ft3/s, accounting for 11 percent of the base flow in

  2. 1996 Atlanta Centennial Olympic Games and Paralympic Games, event study

    Science.gov (United States)

    1997-01-01

    The Atlanta metropolitan region was the location of one of the most ambitious Intelligent Transportation : Systems (ITS) deployments in the United States. This deployment included several individual projects-a : Central Transportation Management Cent...

  3. Disparities in herpes simplex virus type 2 infection between black and white men who have sex with men in Atlanta, GA.

    Science.gov (United States)

    Okafor, Netochukwu; Rosenberg, Eli S; Luisi, Nicole; Sanchez, Travis; del Rio, Carlos; Sullivan, Patrick S; Kelley, Colleen F

    2015-09-01

    HIV disproportionately affects black men who have sex with men, and herpes simplex virus type 2 is known to increase acquisition of HIV. However, data on racial disparities in herpes simplex virus type 2 prevalence and risk factors are limited among men who have sex with men in the United States. InvolveMENt was a cohort study of black and white HIV-negative men who have sex with men in Atlanta, GA. Univariate and multivariate cross-sectional associations with herpes simplex virus type 2 seroprevalence were assessed among 455 HIV-negative men who have sex with men for demographic, behavioural and social determinant risk factors using logistic regression. Seroprevalence of herpes simplex virus type 2 was 23% (48/211) for black and 16% (38/244) for white men who have sex with men (p = 0.05). Education, poverty, drug/alcohol use, incarceration, circumcision, unprotected anal intercourse, and condom use were not associated with herpes simplex virus type 2. In multivariate analyses, black race for those ≤25 years, but not >25 years, and number of sexual partners were significantly associated. Young black men who have sex with men are disproportionately affected by herpes simplex virus type 2, which may contribute to disparities in HIV acquisition. An extensive assessment of risk factors did not explain this disparity in herpes simplex virus type 2 infection suggesting differences in susceptibility or partner characteristics. © The Author(s) 2014.

  4. HIV sexual transmission risks in the context of clinical care: a prospective study of behavioural correlates of HIV suppression in a community sample, Atlanta, GA, USA.

    Science.gov (United States)

    Kalichman, Seth C; Cherry, Chauncey; Kalichman, Moira O; Washington, Christopher; Grebler, Tamar; Merely, Cindy; Welles, Brandi; Pellowski, Jennifer; Kegler, Christopher

    2015-01-01

    Antiretroviral therapy (ART) improves the health of people living with HIV and has the potential to reduce HIV infectiousness, thereby preventing HIV transmission. However, the success of ART for HIV prevention hinges on sustained ART adherence and avoiding sexually transmitted infections (STI). To determine the sexual behaviours and HIV transmission risks of individuals with suppressed and unsuppressed HIV replication (i.e., viral load). Assessed HIV sexual transmission risks among individuals with clinically determined suppressed and unsuppressed HIV. Participants were 760 men and 280 women living with HIV in Atlanta, GA, USA, who completed behavioural assessments, 28-daily prospective sexual behaviour diaries, one-month prospective unannounced pill counts for ART adherence, urine screening for illicit drug use and medical record chart abstraction for HIV viral load. Individuals with unsuppressed HIV demonstrated a constellation of behavioural risks for transmitting HIV to uninfected sex partners that included symptoms of STI and substance use. In addition, 15% of participants with suppressed HIV had recent STI symptoms/diagnoses, indicating significant risks for sexual infectiousness despite their HIV suppression in blood plasma. Overall, 38% of participants were at risk for elevated sexual infectiousness and just as many engaged in unprotected sexual intercourse with non-HIV-infected partners. Implementation strategies for using HIV treatments as HIV prevention requires enhanced behavioural interventions that extend beyond ART to address substance use and sexual health that will otherwise undermine the potential preventive impact of early ART.

  5. Political Socialization in an International City: The Case of Atlanta.

    Science.gov (United States)

    Masters, Paul E., Jr.

    1984-01-01

    Original survey data dealing with the attitudes about international relations of secondary students in the metropolitan Atlanta, Georgia, area are analyzed. Student opinions were measured in three areas: (1) international interest, knowledge, and information sources; (2) international conflict and the balance of power; and (3) international…

  6. Evaluation of a Pilot Surveillance System: Health and Environment Linked for Information Exchange in Atlanta (HELIX-Atlanta)

    Science.gov (United States)

    Meyer, P.; Shire, J.; Qualters, Judy; Daley, Randolph; Fiero, Leslie Todorov; Autry, Andy; Avchen, Rachel; Stock, Allison; Correa, Adolofo; Siffel, Csaba; hide

    2007-01-01

    CDC and its partners established the Health and Environment Linked for Information Exchange, Atlanta (HELIX-Atlanta) demonstration project, to develop linking and analysis methods that could be used by the National Environmental Public Health Tracking (EPHT) Network. Initiated in October 2003, the Metropolitan Atlanta-based collaborative conducted four projects: asthma and particulate air pollution, birth defects and ozone and particulate air pollution, childhood leukemia and traffic emissions, and children's blood lead testing and neighborhood risk factors for lead poisoning. This report provides an overview of the HELIX-Atlanta projects' goals, methods and outcomes. We discuss priority attributes and common issues and challenges and offer recommendations for implementation of the nascent national environmental public health tracking network.

  7. Project ATLANTA (ATlanta Land-use ANalysis: Temperature and Air quality): A Study of how the Urban Landscape Affects Meteorology and Air Quality Through Time

    Science.gov (United States)

    Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G.; Lo, C. P.; Kidder, Stanley Q.; Hafner, Jan; Taha, Haider; Bornstein, Robert D.; Gillies, Robert R.; Gallo, Kevin P.

    1998-01-01

    It is our intent through this investigation to help facilitate measures that can be Project ATLANTA (ATlanta Land-use ANalysis: applied to mitigate climatological or air quality Temperature and Air-quality) is a NASA Earth degradation, or to design alternate measures to sustain Observing System (EOS) Interdisciplinary Science or improve the overall urban environment in the future. investigation that seeks to observe, measure, model, and analyze how the rapid growth of the Atlanta. The primary objectives for this research effort are: 1) To In the last half of the 20th century, Atlanta, investigate and model the relationship between Atlanta Georgia has risen as the premier commercial, urban growth, land cover change, and the development industrial, and transportation urban area of the of the urban heat island phenomenon through time at southeastern United States. The rapid growth of the nested spatial scales from local to regional; 2) To Atlanta area, particularly within the last 25 years, has investigate and model the relationship between Atlanta made Atlanta one of the fastest growing metropolitan urban growth and land cover change on air quality areas in the United States. The population of the through time at nested spatial scales from local to Atlanta metropolitan area increased 27% between 1970 regional; and 3) To model the overall effects of urban and 1980, and 33% between 1980-1990 (Research development on surface energy budget characteristics Atlanta, Inc., 1993). Concomitant with this high rate of across the Atlanta urban landscape through time at population growth, has been an explosive growth in nested spatial scales from local to regional. Our key retail, industrial, commercial, and transportation goal is to derive a better scientific understanding of how services within the Atlanta region. This has resulted in land cover changes associated with urbanization in the tremendous land cover change dynamics within the Atlanta area, principally in transforming

  8. Hybrid Multistarting GA-Tabu Search Method for the Placement of BtB Converters for Korean Metropolitan Ring Grid

    Directory of Open Access Journals (Sweden)

    Remund J. Labios

    2016-01-01

    Full Text Available This paper presents a method to determine the optimal locations for installing back-to-back (BtB converters in a power grid as a countermeasure to reduce fault current levels. The installation of BtB converters can be regarded as network reconfiguration. For the purpose, a hybrid multistarting GA-tabu search method was used to determine the best locations from a preselected list of candidate locations. The constraints used in determining the best locations include circuit breaker fault current limits, proximity of proposed locations, and capability of the solution to reach power flow convergence. A simple power injection model after applying line-opening on selected branches was used as a means for power flows with BtB converters. Kron reduction was also applied as a method for network reduction for fast evaluation of fault currents with a given topology. Simulations of the search method were performed on the Korean power system, particularly the Seoul metropolitan area.

  9. Atlanta NAVIGATOR case study. Final report, May 1996--Jun 1997

    Energy Technology Data Exchange (ETDEWEB)

    Amodei, R.; Bard, E.; Brong, B.; Cahoon, F.; Jasper, K.

    1998-11-01

    The Atlanta metropolitan region was the location of one of the most ambitious Intelligent Transportation Systems (ITS) deployments in the United States. This deployment included several individual projects--a Central Transportation Management Center (TMC), six Traffic Control Centers (TCC), one Transit Information Center (TIC), the Travel Information Showcase (TIS), and the extension of the Metropolitan Atlanta Rapid Transit Authority (MARTA) rail network and the new high-occupancy vehicle (HOV) lanes on I-85 and I-75. The Atlanta Centennial Olympic Games and Paralympic Games created a focus for these projects. All of these systems were to be brought on line in time for the Olympic Games. This report presents the findings of the NAVIGATOR Case Study and documents the lessons learned from the Atlanta ITS deployment experience in order to improve other ITS deployments in the future. The Case Study focuses on the institutional, programmatic, and technical issues and opportunities from planning and implementing the ITS deployment in Atlanta. The Case Study collected data and information from interviews, observations, focus groups, and documentation reviews. It presents a series of lessons learned and recommendations for enabling successful ITS deployments nationwide.

  10. Environmental Public Health Survelliance for Exposure to Respiratory Health Hazards: A Joint NASA/CDC Project to Use Remote Sensing Data for Estimating Airborne Particulate Matter Over the Atlanta, Georgia Metropolitan Area

    Science.gov (United States)

    Quattrochi, Dale A.; Rickman, Douglas; Mohammad, Al-Hamdan; Crosson, William; Estes, Maurice, Jr.; Limaye, Ashutosh; Qualters, Judith

    2008-01-01

    Describes the public health surveillance efforts of NASA, in a joint effort with the Center for Disease Control (CDC). NASA/MSFC and the CDC are partners in linking nvironmental and health data to enhance public health surveillance. The use of NASA technology creates value - added geospatial products from existing environmental data sources to facilitate public health linkages. The venture sought to provide remote sensing data for the 5-country Metro-Atlanta area and to integrate this environmental data with public health data into a local network, in an effort to prevent and control environmentally related health effects. Remote sensing data used environmental data (Environmental Protection Agency [EPA] Air Quality System [AQS] ground measurements and MODIS Aerosol Optical Depth [AOD]) to estimate airborne particulate matter over Atlanta, and linked this data with health data related to asthma. The study proved the feasibility of linking environmental data (MODIS particular matter estimates and AQS) with health data (asthma). Algorithms were developed for QC, bias removal, merging MODIS and AQS particulate matter data, as well as for other applications. Additionally, a Business Associate Agreement was negotiated for a health care provider to enable sharing of Protected Health Information.

  11. Increasing Walking in the Hartsfield-Jackson Atlanta International Airport: The Walk to Fly Study.

    Science.gov (United States)

    Fulton, Janet E; Frederick, Ginny M; Paul, Prabasaj; Omura, John D; Carlson, Susan A; Dorn, Joan M

    2017-07-01

    To test the effectiveness of a point-of-decision intervention to prompt walking, versus motorized transport, in a large metropolitan airport. We installed point-of-decision prompt signage at 4 locations in the airport transportation mall at Hartsfield-Jackson Atlanta International Airport (Atlanta, GA) at the connecting corridor between airport concourses. Six ceiling-mounted infrared sensors counted travelers entering and exiting the study location. We collected traveler counts from June 2013 to May 2016 when construction was present and absent (preintervention period: June 2013-September 2014; postintervention period: September 2014-May 2016). We used a model that incorporated weekly walking variation to estimate the intervention effect on walking. There was an 11.0% to 16.7% relative increase in walking in the absence of airport construction where 580 to 810 more travelers per day chose to walk. Through May 2016, travelers completed 390 000 additional walking trips. The Walk to Fly study demonstrated a significant and sustained increase in the number of airport travelers choosing to walk. Providing signage about options to walk in busy locations where reasonable walking options are available may improve population levels of physical activity and therefore improve public health.

  12. Project ATLANTA (Atlanta Land use Analysis: Temperature and Air Quality): Use of Remote Sensing and Modeling to Analyze How Urban Land Use Change Affects Meteorology and Air Quality Through Time

    Science.gov (United States)

    Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G., Jr.

    1999-01-01

    This paper presents an overview of Project ATLANTA (ATlanta Land use ANalysis: Temperature and Air-quality) which is an investigation that seeks to observe, measure, model, and analyze how the rapid growth of the Atlanta, Georgia metropolitan area since the early 1970's has impacted the region's climate and air quality. The primary objectives for this research effort are: (1) To investigate and model the relationships between land cover change in the Atlanta metropolitan, and the development of the urban heat island phenomenon through time; (2) To investigate and model the temporal relationships between Atlanta urban growth and land cover change on air quality; and (3) To model the overall effects of urban development on surface energy budget characteristics across the Atlanta urban landscape through time. Our key goal is to derive a better scientific understanding of how land cover changes associated with urbanization in the Atlanta area, principally in transforming forest lands to urban land covers through time, has, and will, effect local and regional climate, surface energy flux, and air quality characteristics. Allied with this goal is the prospect that the results from this research can be applied by urban planners, environmental managers and other decision-makers, for determining how urbanization has impacted the climate and overall environment of the Atlanta area. Multiscaled remote sensing data, particularly high resolution thermal infrared data, are integral to this study for the analysis of thermal energy fluxes across the Atlanta urban landscape.

  13. Counseling Spanish-speaking patients: Atlanta pharmacists' cultural sensitivity, use of language-assistance services, and attitudes.

    Science.gov (United States)

    Muzyk, Andrew J; Muzyk, Tara L; Barnett, Candace W

    2004-01-01

    To document the types of language-assistance services available in pharmacies and the perceptions of pharmacists regarding the effectiveness of these services, and to measure the attitudes toward counseling Spanish-speaking patients and cultural sensitivity of pharmacists. Cross-sectional assessment. Metropolitan Atlanta, Ga. Registered Georgia pharmacists residing in metropolitan Atlanta. Mailed survey, with repeat mailing 2 weeks later. 38 survey items measuring demographic and practice-site characteristics, types of language-assistance services available with an assessment of the effectiveness of each measured on a nominal scale, and attitudinal items concerning counseling of Spanish-speaking patients and pharmacists' cultural sensitivity using a 5-point Likert-type response scale. Of 1,975 questionnaires mailed, 608 were returned, a 30.8% response rate. Nearly two thirds of the pharmacists had recently counseled a Spanish-speaking patient, but only one fourth of those respondents considered their interactions effective. Nearly all pharmacists, 88.0%, worked in pharmacies with language-assistance services. Of seven types of these services, a mean of 2.19 were available in pharmacies, and the majority of pharmacists (84.4% or more) identifying a service considered it to be effective. The pharmacists were neutral about counseling Spanish-speaking patients (mean = 2.94) and indifferent toward other cultures (mean = 3.28); however, they agreed they had a responsibility to counsel Spanish-speaking patients, and they believed that use of language-assistance services would constitute a reasonable effort to counsel these patients. Pharmacists have an opportunity to address barriers to communication with the Spanish-speaking population through use of language-assistance services and educational measures within the profession.

  14. Selected papers from the 12th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2012) (Atlanta, GA, USA, 2-5 December 2012)

    Science.gov (United States)

    Allen, Mark G.; Lang, Jeffrey

    2013-11-01

    Welcome to this special section of the Journal of Micromechanics and Microengineering (JMM). This section, co-edited by myself and by Professor Jeffrey Lang of the Massachusetts Institute of Technology, contains expanded versions of selected papers presented at the Power MEMS meeting held in Atlanta, GA, USA, in December of 2012. Professor Lang and I had the privilege of co-chairing Power MEMS 2012, the 12th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications. The scope of the PowerMEMS series of workshops ranges from basic principles, to materials and fabrication, to devices and systems, to applications. The many applications of power MEMS (microelectromehcanical systems) range from MEMS-enabled energy harvesting, storage, conversion and conditioning, to integrated systems that manage these processes. Why is the power MEMS field growing in importance? Smaller-scale power and power supplies (microwatts to tens of watts) are gaining in prominence due to many factors, including the ubiquity of low power portable electronic equipment and the proliferation of wireless sensor nodes that require extraction of energy from their embedding environment in order to function. MEMS manufacturing methods can be utilized to improve the performance of traditional power supply elements, such as allowing batteries to charge faster or shrinking the physical size of passive elements in small-scale power supplies. MEMS technologies can be used to fabricate energy harvesters that extract energy from an embedding environment to power wireless sensor nodes, in-body medical implants and other devices, in which the harvesters are on the small scales that are appropriately matched to the overall size of these microsystems. MEMS can enable the manufacturing of energy storage elements from nontraditional materials by bringing appropriate structure and surface morphology to these materials as well as fabricating the electrical interfaces

  15. A Pilot Study of Halal Goat-Meat Consumption in Atlanta, Georgia

    OpenAIRE

    Ibrahim, Mohammed; Liu, Xuanli; Nelson, Mack C.

    2008-01-01

    Atlanta is a relatively large market for goat meat. As in most metropolitan areas around the U.S., goat-meat consumption has grown steadily in Atlanta over the past decade (Northwest Cooperative Development Center 2005; Nettles and Bukenya 2004). This growth is attributed to the influx of immigrants from goat-meat-eating countries into the U.S. over the same period (Gipson 1999). The increase in demand for goat meat has made the U.S. a net importer of competitively priced goat meat from Austr...

  16. Water crisis: the metropolitan Atlanta, Georgia, regional water supply conflict

    KAUST Repository

    Missimer, Thomas M.; Danser, Philip Alexander; Amy, Gary L.; Pankratz, Tom M.

    2014-01-01

    decades. Drought and environmental management of the reservoir combined to create a water shortage which nearly caused a disaster to the region in 2007 (only about 35 days of water supply was in reserve). While the region has made progress in controlling

  17. Atlanta Centennial Olympic Games and Paralympic Games event study, 1996. Final report, July 1996--August 1996

    Energy Technology Data Exchange (ETDEWEB)

    Amodei, R.; Bard, E.; Brong, B.; Cahoon, F.; Jasper, K.

    1998-11-01

    The Atlanta metropolitan region was the location of one of the most ambitious Intelligent Transportation Systems (ITS) deployments in the United States. This deployment included several individual projects--a Central Transportation Management Center (TMC), six Traffic Control Centers (TCCs), one Transit Information Center (TIC), The Travel Information Showcase (TIS), and the extension of the Metropolitan Atlanta Rapid Transit Authority (MARTA) Rail network and the new high-occupancy vehicle (HOV) lanes on I-85 and I-75. The 1996 Atlanta Centennial Olympic Games and Paralympic Games created a focus for these projects. All of these systems were to be brought on-line in time for the Olympic Games. This report presents the findings of the 1996 Olympic and Paralympic Games Events Study--a compilation of findings of system performance, the benefits realized, and the lessons learned during their operations over the event period. The study assessed the performance of the various Travel Demand Management (TDM) plans employed for Olympic Games traffic management.

  18. Meteorological detrending of primary and secondary pollutant concentrations: Method application and evaluation using long-term (2000-2012) data in Atlanta

    Science.gov (United States)

    Henneman, Lucas R. F.; Holmes, Heather A.; Mulholland, James A.; Russell, Armistead G.

    2015-10-01

    The effectiveness of air pollution regulations and controls are evaluated based on measured air pollutant concentrations. Air pollution levels, however, are highly sensitive to both emissions and meteorological fluctuations. Therefore, an assessment of the change in air pollutant levels due to emissions controls must account for these meteorological fluctuations. Two empirical methods to quantify the impact of meteorology on pollutant levels are discussed and applied to the 13-year time period between 2000 and 2012 in Atlanta, GA. The methods employ Kolmogorov-Zurbenko filters and linear regressions to detrended pollutant signals into long-term, seasonal, weekly, short-term, and white-noise components. The methods differ in how changes in weekly and holiday emissions are accounted for. Both can provide meteorological adjustments on a daily basis for future use in acute health analyses. The meteorological impact on daily signals of ozone, NOx, CO, SO2, PM2.5, and PM species are quantified. Analyses show that the substantial decreases in seasonal averages of NOx and SO2 correspond with controls implemented in the metropolitan Atlanta area. Detrending allows for the impacts of some controls to be observed with averaging times of as little as 3 months. Annual average concentrations of NOx, SO2, and CO have all fallen by at least 50% since 2000. Reductions in NOx levels, however, do not lead to uniform reductions in ozone. While average detrended summer average maximum daily average 8 h ozone (MDA8h O3) levels fell by 4% (2.2 ± 2 ppb) between 2000 and 2012, winter averages have increased by 12% (3.8 ± 1.4 ppb), providing further evidence that high ozone levels are NOx-limited and lower ozone concentrations are NOx-inhibited. High ozone days (with MDA8h O3 greater than 60 ppb) decreased both in number and in magnitude over the study period.

  19. Health and Environment Linked for Information Exchange in Atlanta (HELIX-Atlanta): A Pilot Tracking System

    Science.gov (United States)

    Rickman, Doug; Shire, J.; Qualters, J.; Mitchell, K.; Pollard, S.; Rao, R.; Kajumba, N.; Quattrochi, D.; Estes, M., Jr.; Meyer, P.; hide

    2009-01-01

    Objectives. To provide an overview of four environmental public health surveillance projects developed by CDC and its partners for the Health and Environment Linked for Information Exchange, Atlanta (HELIX-Atlanta) and to illustrate common issues and challenges encountered in developing an environmental public health tracking system. Methods. HELIX-Atlanta, initiated in October 2003 to develop data linkage and analysis methods that can be used by the National Environmental Public Health Tracking Network (Tracking Network), conducted four projects. We highlight the projects' work, assess attainment of the HELIX-Atlanta goals and discuss three surveillance attributes. Results. Among the major challenges was the complexity of analytic issues which required multidiscipline teams with technical expertise. This expertise and the data resided across multiple organizations. Conclusions:Establishing formal procedures for sharing data, defining data analysis standards and automating analyses, and committing staff with appropriate expertise is needed to support wide implementation of environmental public health tracking.

  20. 78 FR 1742 - Amendment to Class B Airspace; Atlanta, GA

    Science.gov (United States)

    2013-01-09

    ...: Effective Date: 0901 UTC, March 7, 2013. The Director of the Federal Register approves this incorporation by..., resulting in wasted fuel and increased operating costs as well as causing PDK IFR arrivals to circle over... maneuvering room would be available for avoiding obstructions, clouds and turbulence, and for training...

  1. Complejo Omni - Atlanta – (EE. UU.

    Directory of Open Access Journals (Sweden)

    Housworth, Marvin

    1976-12-01

    Full Text Available This complex of buildings, situated in the centre of Atlanta City, forms a dynamic nucleus for various social activities, such as recreational, commercial and business activities. These buildings are constructed above railway nets, due to special property rights for this lot, which constituted one of the main determinants for the characteristics of the property. The unit is made up by a luxurious hotel, two restaurants, office buildings and shopping arcades, arranged around a spacious inner yard. This patio is covered by means of an exceedingly big glass roof, supported by beams and steel framework and is provided with walls of big glazed surfaces. Thus, an intimate and friendly atmosphere is created, free from the contamination and noise of the big city whereby the square displays the typical characteristics of open squares in smaller towns.Este conjunto de edificios, emplazado en el centro de la ciudad de Atlanta, conforma un núcleo dinámico en donde se encuentran diversas actividades de tipo social: recreativas, comerciales y empresariales. Se ha construido sobre ruedas ferroviarias, en virtud de derechos especiales de propiedad que conservaba la parcela, lo que constituyó uno de los principales condicionamientos de fas características del proyecto. El complejo dispone de un hotel de lujo, dos restaurantes, edificios de oficinas y galerías comerciales, dispuestos en torno a un amplio espacio interior, cerrado por una enorme cubierta acristalada, apoyada en vigas y entramados metálicos, y por grandes ventanales corridos entre bloques. Conforma así un ambiente íntimo y acogedor, liberado del ruido y de la atmósfera turbulenta de la gran ciudad, con características propias de las pequeñas plazas populares.

  2. Cryptosporidium and Giardia in Swimming Pools, Atlanta, Georgia

    Centers for Disease Control (CDC) Podcasts

    In this podcast, Dan Rutz speaks with Dr. Joan Shields, a guest researcher with the Healthy Swimming Program at CDC, about an article in June 2008 issue of Emerging Infectious Diseases reporting on the results of a test of swimming pools in the greater Atlanta, Georgia area. Dr. Shields tested 160 pools in metro Atlanta last year for Cryptosporidium and Giardia. These germs cause most recreational water associated outbreaks.

  3. Transit climate change adaptation assessment/asset management pilot for the Metropolitan Atlanta Rapid Transit Authority.

    Science.gov (United States)

    2013-08-01

    Public transit agencies play an important role in the provision of safe, reliable, and cost-effective transportation for the communities they serve. With the growing intensity and frequency of extreme weather events, such as hurricanes Irene and Sand...

  4. SUMMERTIME AMBIENT FORMALDEHYDE IN FIVE U.S. METROPOLITAN AREAS: NASHVILLE, ATLANTA, HOUSTON, PHILADELPHIA, TAMPA

    Science.gov (United States)

    In this paper, we briefly review the atmospheric chemistry and previous intercomparison measurements for HCHO, with special reference to the diffusion scrubber-Hantzsch reaction based fluorescence instrument used in the field studies reported herein. Then we discuss summertime HC...

  5. Maternal knowledge and attitudes toward influenza vaccination: a focus group study in metropolitan Atlanta.

    Science.gov (United States)

    Gazmararian, Julie A; Orenstein, Walter; Prill, Mila; Hitzhusen, Hannah B; Coleman, Margaret S; Pazol, Karen; Oster, Natalia V

    2010-11-01

    To explore the knowledge and attitudes of mothers of school-aged children toward influenza vaccination and assess what methods of communication about vaccination and its delivery work best among this audience. The authors conducted focus groups with mothers of school-aged children. Prior to the focus groups, investigators agreed on key themes and discussion points. They independently reviewed transcripts using systematic content analysis and came to an agreement on outcome themes. Many study participants had misunderstandings about influenza vaccines and the definition of influenza. A common perception was that flu is a catch-all term for a variety of undefined illnesses, ranging from a severe cold to stomach upset. Few participants saw a societal benefit in vaccinating children to protect other populations (eg, the elderly). This study represents a first step in understanding how mothers perceive influenza vaccination and for crafting effective communication to increase vaccination among school-aged children.

  6. Plaza Central Peachtree Atlanta-(EE.UU.

    Directory of Open Access Journals (Sweden)

    Portman, John

    1976-10-01

    Full Text Available This 70-storey hotel has been constructed to meet the requirements of the city of Atlanta which needed a building with a sufficient room capacity and adequate premises for Conventions. On a structure of reinforced concrete which serves as a base and in which the common areas are situated rises a big cylindric tower, covered with coloured glass and which contains the 1.100 rooms. 230 m above ground level, the construction is crowned with a roof top cocktail lounge and a revolving restaurant with a splendid view of the city. Among the most noteworthy characteristics of this hotel is the elegantly decorated entrance hall —atrium shaped and 7 storeys high— with a pond in the centre. Further premises worth mentioning in view of their design and dimensions are the great ball room, coffee-shops and luxurious restaurants, one of which is planned in different levels and in which the most impressive feature is a 30 m high waterfall.Este edificio de setenta plantas se construyó para responder a las necesidades hoteleras de la ciudad de Atlanta, que precisaba de una instalación con suficiente capacidad de habitaciones y preparación para albergar Convenciones. Sobre una estructura de hormigón armado, que sirve de base y en la que se sitúan las zonas comunes, se eleva una gran torre cilíndrica, recubierta de vidrio coloreado reflectante, destinada a distribuir las 1.100 habitaciones con las que cuenta el edificio. La construcción se corona, a 230 m de la cimentación, con una sala para cócteles y un restaurante giratorio desde el que se domina una espléndida vista del contorno. El edificio dispone de importantes servicios comunes, entre los que cabe destacar el hall de entrada —a modo de atrio y con una altura equivalente a siete plantas—, que está dotado de un gran estanque y variados elementos de gran efecto decorativo. Otros servicios notables por su diseño y dimensiones son la gran sala de baile, y las cafeterías, comedores y

  7. Modeling Metropolitan Detroit transit.

    Science.gov (United States)

    2010-10-01

    "The seven-county Southeast Michigan region, that encompasses the Detroit Metropolitan Area, : ranks fifth in population among top 25 regions in the nation. It also ranks among bottom five in : the transit service provided, measured in miles or hours...

  8. Metropolitan water management

    National Research Council Canada - National Science Library

    Milliken, J. Gordon; Taylor, Graham C

    1981-01-01

    This monograph is intended to inform interested and capable pesons, who happen not to be specialists in water resources planning, of the issues and alternative strategies related to metropolitan water supply...

  9. Remote Sensing of Atlanta's Urban Sprawl and the Distribution of Land Cover and Surface Temperature

    Science.gov (United States)

    Laymon, Charles A.; Estes, Maurice G., Jr.; Quattrochi, Dale A.; Goodman, H. Michael (Technical Monitor)

    2001-01-01

    Between 1973 and 1992, an average of 20 ha of forest was lost each day to urban expansion of Atlanta, Georgia. Urban surfaces have very different thermal properties than natural surfaces-storing solar energy throughout the day and continuing to release it as sensible heat well after sunset. The resulting heat island effect serves as catalysts for chemical reactions from vehicular exhaust and industrialization leading to a deterioration in air quality. In this study, high spatial resolution multispectral remote sensing data has been used to characterize the type, thermal properties, and distribution of land surface materials throughout the Atlanta metropolitan area. Ten-meter data were acquired with the Advanced Thermal and Land Applications Sensor (ATLAS) on May 11 and 12, 1997. ATLAS is a 15-channel multispectral scanner that incorporates the Landsat TM bands with additional bands in the middle reflective infrared and thermal infrared range. The high spatial resolution permitted discrimination of discrete surface types (e.g., concrete, asphalt), individual structures (e.g., buildings, houses) and their associated thermal characteristics. There is a strong temperature contrast between vegetation and anthropomorphic features. Vegetation has a modal temperature at about 20 C, whereas asphalt shingles, pavement, and buildings have a modal temperature of about 39 C. Broad-leaf vegetation classes are indistinguishable on a thermal basis alone. There is slightly more variability (+/-5 C) among the urban surfaces. Grasses, mixed vegetation and mixed urban surfaces are intermediate in temperature and are characterized by broader temperature distributions with modes of about 29 C. Thermal maps serve as a basis for understanding the distribution of "hotspots", i.e., how landscape features and urban fabric contribute the most heat to the lower atmosphere.

  10. Remote Sensing of Atlanta's Urban Sprawl and the Distribution of Land Cover and Surface Temperatures

    Science.gov (United States)

    Laymon, Charles A.; Estes, Maurice G., Jr.; Quattrochi, Dale A.; Arnold, James E. (Technical Monitor)

    2001-01-01

    Between 1973 and 1992, an average of 20 ha of forest was lost each day to urban expansion of Atlanta, Georgia. Urban surfaces have very different thermal properties than natural surfaces-storing solar energy throughout the day and continuing to release it as sensible heat well after sunset. The resulting heat island effect serves as catalysts for chemical reactions from vehicular exhaust and industrialization leading to a deterioration in air quality. In this study, high spatial resolution multispectral remote sensing data has been used to characterize the type, thermal properties, and distribution of land surface materials throughout the Atlanta metropolitan area. Ten-meter data were acquired with the Advanced Thermal and Land Applications Sensor (ATLAS) on May 11 and 12, 1997. ATLAS is a 15-channel multispectral scanner that incorporates the Landsat TM bands with additional bands in the middle reflective infrared and thermal infrared range. The high spatial resolution permitted discrimination of discrete surface types (e.g., concrete, asphalt), individual structures (e.g., buildings, houses) and their associated thermal characteristics. There is a strong temperature contrast between vegetation and anthropomorphic features. Vegetation has a modal temperature at about 20 C, whereas asphalt shingles, pavement, and buildings have a modal temperature of about 39 C. Broad-leaf vegetation classes are indistinguishable on a thermal basis alone. There is slightly more variability (plus or minus 5 C) among the urban surfaces. Grasses, mixed vegetation and mixed urban surfaces are intermediate in temperature and are characterized by broader temperature distributions with modes of about 29 C. Thermal maps serve as a basis for understanding the distribution of "hotspots", i.e., how landscape features and urban fabric contribute the most heat to the lower atmosphere.

  11. Efficient Metropolitan Resource Allocation

    Directory of Open Access Journals (Sweden)

    Richard Arnott

    2016-05-01

    Full Text Available Over the past 30 years Calgary has doubled in size, from a population of 640,645 in 1985 to 1,230,915 in 2015. During that time the City has had five different mayors, hosted the Winter Olympics, and expanded the C-Train from 25 platforms to 45. Calgary’s Metropolitan Area has grown too, with Airdrie, Chestermere, Okotoks and Cochrane growing into full-fledged cities, ripe with inter-urban commuters.* And with changes to provincial legislation in the mid-’90s, rural Rocky View County and the Municipal District of Foothills are now real competitors for residential, commercial and industrial development that in the past would have been considered urban. In this metropolitan system, where people live, their household structure, and their place of work informs the services they need to conduct their daily lives, and directly impacts the spatial character of the City and the broader region. In sum, Metropolitan Calgary is increasingly complex. Calgary and the broader metropolitan area will continue to grow, even with the current economic slowdown. Frictions within Calgary, between the various municipalities in the metropolitan area, and the priorities of other local authorities (such as the School Boards and Alberta Health Services will continue to impact the agendas of local politicians and their ability to answer to the needs of their residents. How resources – whether it is hard infrastructure, affordable housing, classrooms, or hospital beds – are allocated over space and how these resources are funded, directly impacts these relationships. This technical paper provides my perspective as an urban economist on the efficient allocation of resources within a metropolitan system in general, with reference to Calgary where appropriate, and serves as a companion to the previously released “Reflections on Calgary’s Spatial Structure: An Urban Economists Critique of Municipal Planning in Calgary.” It is hoped that the concepts reviewed

  12. Cryptosporidium and Giardia in Swimming Pools, Atlanta, Georgia

    Centers for Disease Control (CDC) Podcasts

    2008-05-29

    In this podcast, Dan Rutz speaks with Dr. Joan Shields, a guest researcher with the Healthy Swimming Program at CDC, about an article in June 2008 issue of Emerging Infectious Diseases reporting on the results of a test of swimming pools in the greater Atlanta, Georgia area. Dr. Shields tested 160 pools in metro Atlanta last year for Cryptosporidium and Giardia. These germs cause most recreational water associated outbreaks.  Created: 5/29/2008 by Emerging Infectious Diseases.   Date Released: 5/29/2008.

  13. The Atlanta Urban Debate League: Exploring the Making of a Critical Literacy Space

    Science.gov (United States)

    Cridland-Hughes, Susan

    2016-01-01

    The Atlanta Urban Debate League was established in 1985 as an after school program focused on providing debate outreach to high school students in the Atlanta public schools. Still in operation today, volunteers work with current students in public middle and high schools in Atlanta, supporting students as they practice reading, writing, speaking…

  14. MPLS for metropolitan area networks

    CERN Document Server

    Tan, Nam-Kee

    2004-01-01

    METROPOLITAN AREA NETWORKS AND MPLSRequirements of Metropolitan Area Network ServicesMetropolitan Area Network OverviewThe Bandwidth DemandThe Metro Service Provider's Business ApproachesThe Emerging Metro Customer Expectations and NeedsSome Prevailing Metro Service OpportunitiesService Aspects and RequirementsRoles of MPLS in Metropolitan Area NetworksMPLS PrimerMPLS ApplicationsTRAFFIC ENGINEERING ASPECTS OF METROPOLITAN AREA NETWORKSTraffic Engineering ConceptsNetwork CongestionHyper Aggregation ProblemEasing CongestionNetwork ControlTactical versus Strategic Traffic EngineeringIP/ATM Overl

  15. NEOPLASIA IN SNAKES AT ZOO ATLANTA DURING 1992-2012.

    Science.gov (United States)

    Page-Karjian, Annie; Hahne, Megan; Leach, Kate; Murphy, Hayley; Lock, Brad; Rivera, Samuel

    2017-06-01

    A retrospective study was conducted to review neoplasia of captive snakes in the Zoo Atlanta collection from 1992 to 2012. Of 255 snakes that underwent necropsy and histopathologic examination at Zoo Atlanta during the study period, 37 were observed with neoplasia at necropsy. In those 37 snakes, 42 neoplastic lesions of 18 primary cell types were diagnosed. Thirty-five of those neoplasms (83.3%) were malignant, and of those, 19 were of mesenchymal origin, whereas 14 were of epithelial origin. The median annual rate of neoplasia at necropsy was 12.5% (interquartile range = 2.8-19.5%) over the 21-yr study period. The mean estimated age at death for snakes with neoplasia was 13.2 yr (range, 1-24 yr). Investigating the incidence and clinical significance of neoplasia in captive snakes is vital for developing effective preventative and treatment regimes.

  16. non-metropolitan stars

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2017-06-01

    Full Text Available Capitals gather constellations of bright and creative people, attracting them from the peripheries. Tchekhov’s sisters were anxious to get to Moscow, d’Artagnan – to Paris. Evtushenko, Shukshin and Gaidai ascended to the climax of their glory, having moved to the capital. Vampilov, Rasputin and Astafiev became internationally famous without leaving their home grounds, but having joined in the metropolitan whirl. In this regard, the architectural profession differs greatly from the literary and cinematographic ones. The destinies of the masters who fulfilled themselves far from the capital are different but equally bright and unique. The Irkutsk “Varangians”of the sixtieth – Voronezhsky, Bukh and Pavlov – built up their relations with geography in a different way:someone came from the capitals just for a few years that became the brightest, the most fruitful and the most interesting years of his creative life. But someone stayed in the non-metropolitan city for a long time and even forever. This subsection contains certain examples of self-fulfillment in the cities distant from the capitals: Khabarovsk, Irkutsk, Bratsk, Krasnoyarsk, Kemerovo and Anzhero-Sudzhensk.

  17. Urban Data Book : Volume 1. Urban Data - Atlanta-Miami

    Science.gov (United States)

    1975-11-01

    A quick reference compilation of certain population, socio-economic, employment, and modal split characteristics of the 35 largest Standard Metropolitan Statistical Areas (SMSA) in the United States is presented. The three basic groups or urban data ...

  18. Drinking water turbidity and emergency department visits for gastrointestinal illness in Atlanta, 1993-2004.

    Science.gov (United States)

    Tinker, Sarah C; Moe, Christine L; Klein, Mitchel; Flanders, W Dana; Uber, Jim; Amirtharajah, Appiah; Singer, Philip; Tolbert, Paige E

    2010-01-01

    The extent to which drinking water turbidity measurements indicate the risk of gastrointestinal illness is not well understood. Despite major advances in drinking water treatment and delivery, infectious disease can still be transmitted through drinking water in the United States, and it is important to have reliable indicators of microbial water quality to inform public health decisions. The objective of our study was to assess the relationship between gastrointestinal illness, quantified through emergency department visits, and drinking water quality, quantified as raw water and filtered water turbidity measured at the treatment plant. We examined the relationship between turbidity levels of raw and filtered surface water measured at eight major drinking water treatment plants in the metropolitan area of Atlanta, Georgia, and over 240,000 emergency department visits for gastrointestinal illness during 1993-2004 among the population served by these plants. We fit Poisson time-series statistical regression models that included turbidity in a 21-day distributed lag and that controlled for meteorological factors and long-term time trends. For filtered water turbidity, the results were consistent with no association with emergency department visits for gastrointestinal illness. We observed a modest association between raw water turbidity and emergency department visits for gastrointestinal illness. Our results suggest that source water quality may contribute modestly to endemic gastrointestinal illness in the study area. The association between turbidity and emergency department visits for gastrointestinal illness was only observed when raw water turbidity was considered; filtered water turbidity may not serve as a reliable indicator of modest pathogen risk at all treatment plants.

  19. DRINKING WATER TURBIDITY AND EMERGENCY DEPARTMENT VISITS FOR GASTROINTESTINAL ILLNESS IN ATLANTA, 1993 – 2004

    Science.gov (United States)

    Tinker, Sarah C.; Moe, Christine L.; Klein, Mitchel; Flanders, W. Dana; Uber, Jim; Amirtharajah, Appiah; Singer, Philip; Tolbert, Paige E.

    2013-01-01

    Background The extent to which drinking water turbidity measurements indicate the risk of gastrointestinal illness is not well-understood. Despite major advances in drinking water treatment and delivery, infectious disease can still be transmitted through drinking water in the U.S., and it is important to have reliable indicators of microbial water quality to inform public health decisions. The objective of our study was to assess the relationship between gastrointestinal illness, quantified through emergency department visits, and drinking water quality, quantified as raw water and filtered water turbidity measured at the treatment plant. Methods We examined the relationship between turbidity levels of raw and filtered surface water measured at eight major drinking water treatment plants in the metropolitan area of Atlanta, Georgia, and over 240 000 emergency department visits for gastrointestinal illness during 1993–2004 among the population served by these plants. We fit Poisson time-series statistical regression models that included turbidity in a 21-day distributed lag and that controlled for meteorological factors and long-term time trends. Results For filtered water turbidity, the results were consistent with no association with emergency department visits for gastrointestinal illness. We observed a modest association between raw water turbidity and emergency department visits for gastrointestinal illness. This association was not observed for all treatment plants in plant-specific analyses. Conclusions Our results suggest that source water quality may contribute modestly to endemic gastrointestinal illness in the study area. The association between turbidity and emergency department visits for gastrointestinal illness was only observed when raw water turbidity was considered; filtered water turbidity may not serve as a reliable indicator of modest pathogen risk at all treatment plants. PMID:18941478

  20. Acute pancreatitis: reflections through the history of the Atlanta Consensus

    OpenAIRE

    Torres López, Ana María; Hoyos Duque, Sergio Iván

    2014-01-01

    Acute pancreatitis is an inflammatory process with systemic and local repercussions. Most cases are mild with low mortality rate, but 20% of the patients have severe pancreatitis with a mortality rate up to 30%. Through the years the medical community has tried to reach consensus about this disease in order to better understand, classify and treat it. The most important of these has been known as the Atlanta Consensus 1992, in use for many years. However, it has been recently the subject of v...

  1. Acute pancreatitis: reflections through the history of the Atlanta Consensus

    Directory of Open Access Journals (Sweden)

    Torres López, Ana María

    2014-10-01

    Full Text Available Acute pancreatitis is an inflammatory process with systemic and local repercussions. Most cases are mild with low mortality rate, but 20% of the patients have severe pancreatitis with a mortality rate up to 30%. Through the years the medical community has tried to reach consensus about this disease in order to better understand, classify and treat it. The most important of these has been known as the Atlanta Consensus 1992, in use for many years. However, it has been recently the subject of various proposals for changes and updates, which are discussed in this review article.

  2. Metropolitan Lima: area profile.

    Science.gov (United States)

    Hakkert, R

    1986-11-01

    This profile of metropolitan Lima, Peru, covers administrative divisions; population growth; age distribution; ethnicity and religion; housing and households; education and health care; economic activity, income, and consumption; transport and communication; and sources of information. Nearly 30% of Peru's entire population and 42% of its urban population live in Lima. The trend continues, yet Lima's urban primacy is waning due to the growth of some regional centers like Trujillo and Chimbote. Lima is still almost 10 times as large as the country's next ranking cities, Trujillo on the northern coast and Arequipa in the south. Peru's main administrative divisions are the 24 departments, of which the Department of Lima is one. These departments are further divided into 156 provinces. Greater Lima consists of 2 such provinces, the province of Lima and the constitutional province of Callao. Although the population of Lima continues to grow, its rate of growth slowed from about 5.5% during the 1960s to about 3.9% in the 1970s. Current projections estimate a metropolitan population of 6.7 million by 1990. On the whole, Lima's age structure is somewhat older than that of the rest of Peru. The median age of the population is 22.3 years, compared to a national figure of 20.4. The proportion of persons over age 65 is only 3.6%, lower than the national average of 4.1%, due to the tendency of in-migration to concentrate people of intermediate ages in the cities. Almost 400,000 inhabitants of greater Lima are bilingual in Spanish and an indigenous language. As elsewhere in Peru, the dominant religion is Roman Catholicism. Lima is a spread out city with few high rise buildings due to the danger of earthquakes. Only 12% of Lima's households are found in apartment buildings. As in other cities of Latin America, the formal housing market is beyond the reach of a major segment of the population. Consequently, much of the urban settlement has occurred through informal self

  3. Why, Where, and How to Infuse the Atlanta Sociological Laboratory into the Sociology Curriculum

    Science.gov (United States)

    Wright, Earl, II

    2012-01-01

    The Atlanta Sociological Laboratory is the moniker bestowed on scholars engaged in sociological research at Atlanta University between 1895 and 1924. Under the leadership of W. E. B. Du Bois, 1897-1914, this school made substantive yet marginalized contributions to the discipline. Its accomplishments include, but are not limited to, its…

  4. Atlanta Rail Yard Study: Evaluation of local-scale air pollution ...

    Science.gov (United States)

    Intermodal rail yards are important nodes in the freight transportation network, where freight is organized and moved from one mode of transport to another, critical equipment is serviced, and freight is routed to its next destination. Rail yard environments are also areas with multiple sources of air pollutant emissions (e.g., heavy-duty vehicles, locomotives, cranes), which may affect local air quality in residential areas nearby. In order to understand emissions and related air quality impacts, two field studies took place over the time span of 2010-2012 to measure air pollution trends in close proximity to the Inman and Tilford rail yard complex in Atlanta, GA. One field study involved long-term stationary monitoring of black carbon, fine particles, and carbon dioxide at two stations nearby the rail yard. In addition, a second field study performed intensive mobile air monitoring for a one month period in the summer of 2012 at a roadway network surrounding the rail yard complex and measured a comprehensive array of pollutants. Real-time mobile particulate measurements included particle counts, extinction coefficient, black carbon via light-absorption and particle incandescence, and particle composition derived by aerosol mass spectrometry. Gas-phase measurements included oxides of nitrogen, sulfur dioxide, carbon dioxide, and air toxics (e.g., benzene). Both sets of measurements determined detectable local influence from rail yard-related emissions.

  5. Flight delay performance at Hartsfield-Jackson Atlanta International Airport

    Directory of Open Access Journals (Sweden)

    Grigoriy Yablonsky

    2014-01-01

    Full Text Available Purpose: The main objective of this paper is to determine the annual cyclical flight delays at Hartsfield-Jackson Atlanta International Airport. Then using other data such as annual precipitation, passenger and aircraft traffic volumes and other factors, we attempted to correlate these factors with overall delays. These data could assist airport management in predicting periods of flight delay.Design/methodology/approach: Data were taken and analyzed from the data base “Research and Innovation Technology Administration” (RITA for the years 2005-2011 for Hartsfield-Jackson Atlanta International Airport. The data included 2.8 million flights originating and departing from this airport. Data were also gathered from the National Oceanic and Atmospheric Administration (NOAA showing precipitation. Additional data were gathered from the FAA regarding delay causes, number and types of delays and changes to the infrastructure of ATL airportFindings: There is a repeatable annual pattern of delays at ATL that can be modeled using delay data from the Bureau of Transportation Statistics. This pattern appears to be caused primarily by the frequency and amount of precipitation that falls at ATL and by the amount of flights that arrive and depart at ATL.Originality/value: This information could assist airport operations personnel, FAA air traffic controllers and airlines in anticipating and mitigating delays at specific times of the year.

  6. Trends in on-road vehicle emissions and ambient air quality in Atlanta, Georgia, USA, from the late 1990s through 2009.

    Science.gov (United States)

    Vijayaraghavan, Krish; DenBleyker, Allison; Ma, Lan; Lindhjem, Chris; Yarwood, Greg

    2014-07-01

    On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NO(x)), and volatile organic compounds (VOCs) during 1995-2009 in the Atlanta Metropolitan Statistical Area were estimated using the Motor Vehicle Emission Simulator (MOVES) model and data from the National Emissions Inventories and the State of Georgia. Statistically significant downward trends (computed using the nonparametric Theil-Sen method) in annual on-road CO, NO(x), and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 1995-2009 period despite an increase in total vehicle distance traveled. The CO and NO(x) emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NO(x) in Atlanta ranging from 8.0% to 11.8% per year and from 5.8% to 8.7% per year, respectively, during similar time periods. Weather-adjusted summertime ozone concentrations in Atlanta exhibited a statistically significant declining trend of 2.3% per year during 2001-2009. Although this trend coexists with the declining trends in on-road NO(x), VOC, and CO emissions, identifying the cause of the downward trend in ozone is complicated by reductions in multiple precursors from different source sectors. Implications: Large reductions in on-road vehicle emissions of CO and NO(x) in Atlanta from the late 1990s to 2009, despite an increase in total vehicle distance traveled, contributed to a significant improvement in air quality through decreases in ambient air concentrations of CO and NO(x) during this time period. Emissions reductions in motor vehicles and other source sectors resulted in these improvements and the observed declining trend in ozone concentrations over the past decade. Although these historical trends cannot be extrapolated to the future because pollutant concentration contributions due to on-road vehicle emissions will likely become an increasingly smaller fraction of the atmospheric total, they provide an indication of

  7. Metropolitan City: the Italian experience

    Directory of Open Access Journals (Sweden)

    Giuseppe Franco Ferrari

    2013-12-01

    Full Text Available Due to the fact that the definitions of territorial organization are no longer adequate, the concept of “metropolitan areas” arises as a solution to resolve such deficit. This study shows the beginnings of this figure in Italy and the problems of identification and delimitation caused by the abstraction of the norms, therefore entailing a difficult implementation of the concept of metropolitan cities. By identifying these obstacles, this paper presents an analysis where it is possible to ensure compliance with this new reality in the near future.

  8. GLOBECOM '84 - Global Telecommunications Conference, Atlanta, GA, November 26-29, 1984, Conference Record. Volume 1

    Science.gov (United States)

    The subjects discussed are related to LSI/VLSI based subscriber transmission and customer access for the Integrated Services Digital Network (ISDN), special applications of fiber optics, ISDN and competitive telecommunication services, technical preparations for the Geostationary-Satellite Orbit Conference, high-capacity statistical switching fabrics, networking and distributed systems software, adaptive arrays and cancelers, synchronization and tracking, speech processing, advances in communication terminals, full-color videotex, and a performance analysis of protocols. Advances in data communications are considered along with transmission network plans and progress, direct broadcast satellite systems, packet radio system aspects, radio-new and developing technologies and applications, the management of software quality, and Open Systems Interconnection (OSI) aspects of telematic services. Attention is given to personal computers and OSI, the role of software reliability measurement in information systems, and an active array antenna for the next-generation direct broadcast satellite.

  9. 77 FR 5429 - Proposed Modification of the Atlanta Class B Airspace Area; GA

    Science.gov (United States)

    2012-02-03

    ... consisted of lower Class B floors within a reduced radius of 30 NM from the ATL VORTAC as opposed to the... concerns related to the proposed lower Class B airspace floors, particularly in the airspace directly... congestion at lower altitudes due to VFR traffic trying to avoid flying in the Class B airspace area and...

  10. 78 FR 70895 - Proposed Establishment and Modification of Area Navigation (RNAV) Routes; Atlanta, GA

    Science.gov (United States)

    2013-11-27

    ... Management Facility (see ADDRESSES section for address and phone number). You may also submit comments...), Buffalo Niagara International (BUF) and Toronto Pearson International (TOR) airports. Additionally, Q-69...

  11. GLOBECOM '84 - Global Telecommunications Conference, Atlanta, GA, November 26-29, 1984, Conference Record. Volume 3

    Science.gov (United States)

    Attention is given to aspects of quality assurance methodologies in development life cycles, optical intercity transmission systems, multiaccess protocols, system and technology aspects in the case of regional/domestic satellites, advances in SSB-AM radio transmission over terrestrial and satellite network, and development environments for telecommunications systems. Other subjects studied are concerned with business communication networks for voice and data, VLSI in local network and communication protocol, product evaluation and support, an update regarding Videotex, topics in communication theory, topics in radio propagation, a status report regarding societal effects of technology in the workplace, digital image processing, and adaptive signal processing for communications. The management of the reliability function in the development process is considered along with Giga-bit technologies for long distance large capacity optical transmission equipment. The application of gallium arsenide analog and digital integrated circuits for high-speed fiber optical communications, and a simple algorithm for image data coding.

  12. DOE ZERH Case Study: Heirloom Design Build, Euclid Avenue, Atlanta, GA

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2015-09-01

    Case study of a DOE 2015 Housing Innovation Award winning custom home in the mixed-humid climate that got a HERS 50 without PV, with 2x6 16” on center walls with R-19 ocsf; basement with R-28 ccsf, R-5 rigid foam under slab; sealed attic with R-28 ocsf under roof deck; 22.8 SEER; 12.5 HSPF heat pump.

  13. Remote Sensing and Spatial Growth Modeling Coupled With Air Quality Modeling to Assess the Impact of Atlanta, Georgia on the Local and Regional Environment

    Science.gov (United States)

    Quattrochi, D. A.; Estes, M. G.; Crosson, W. L.; Johnson, H.; Khan, M.

    2006-05-01

    The growth of cities, both in population and areal extent, appears as an inexorable process. Urbanization continues at a rapid rate, and it is estimated that by the year 2025, 60 percent of the world's population will live in cities. Urban expansion has profound impacts on a host of biophysical, environmental, and atmospheric processes within an urban ecosystems perspective. A reduction in air quality over cities is a major result of these impacts. Because of its complexity, the urban landscape is not adequately captured in air quality models such as the Community Multiscale Air Quality (CMAQ) model that is used to assess whether urban areas are in attainment of EPA air quality standards, primarily for ground level ozone. This inadequacy of the CMAQ model to sufficiently respond to the heterogeneous nature of the urban landscape can impact how well the model predicts ozone levels over metropolitan areas and ultimately, whether cities exceed EPA ozone air quality standards. We are exploring the utility of high-resolution remote sensing data and urban spatial growth modeling (SGM) projections as improved inputs to a meteorological/air quality modeling system focusing on the Atlanta, Georgia metropolitan area as a case study. These growth projections include "business as usual" and "smart growth" scenarios out to 2030. The growth projections illustrate the effects of employing urban heat island mitigation strategies, such as increasing tree canopy and albedo across the Atlanta metro area, which in turn, are used to model how air temperature can potentially be moderated as impacts on elevating ground-level ozone, as opposed to not utilizing heat island mitigation strategies. The National Land Cover Dataset at 30m resolution is being used as the land use/land cover input and aggregated to the 4km scale for the MM5 mesoscale meteorological model and the CMAQ modeling schemes. Use of these data has been found to better characterize low density/suburban development as

  14. Spatial Growth Modeling and High Resolution Remote Sensing Data Coupled with Air Quality Modeling to Assess the Impact of Atlanta, Georgia on the Local and Regional Environment

    Science.gov (United States)

    Quattrochi, Dale A.; Estes, Maurice G., Jr.; Crosson, William; Johnson, Hoyt; Khan, Maudood

    2006-01-01

    The growth of cities, both in population and areal extent, appears as an inexorable process. Urbanization continues at a rapid rate, and it is estimated that by the year 2025, 60 percent of the world s population will live in cities. Urban expansion has profound impacts on a host of biophysical, environmental, and atmospheric processes within an urban ecosystems perspective. A reduction in air quality over cities is a major result of these impacts. Because of its complexity, the urban landscape is not adequately captured in air quality models such as the Community Multiscale Air Quality (CMAQ) model that is used to assess whether urban areas are in attainment of EPA air quality standards, primarily for ground level ozone. This inadequacy of the CMAQ model to sufficiently respond to the heterogeneous nature of the urban landscape can impact how well the model predicts ozone levels over metropolitan areas and ultimately, whether cities exceed EPA ozone air quality standards. We are exploring the utility of high-resolution remote sensing data and urban spatial growth modeling (SGM) projections as improved inputs to a meteorological/air quality modeling system focusing on the Atlanta, Georgia metropolitan area as a case study. These growth projections include business as usual and smart growth scenarios out to 2030. The growth projections illustrate the effects of employing urban heat island mitigation strategies, such as increasing tree canopy and albedo across the Atlanta metro area, which in turn, are used to model how air temperature can potentially be moderated as impacts on elevating ground-level ozone, as opposed to not utilizing heat island mitigation strategies. The National Land Cover Dataset at 30m resolution is being used as the land use/land cover input and aggregated to the 4km scale for the MM5 mesoscale meteorological model and the CMAQ modeling schemes. Use of these data has been found to better characterize low density/suburban development as compared

  15. Willingness to use pre-exposure prophylaxis among Black and White men who have sex with men in Atlanta, Georgia.

    Science.gov (United States)

    Rolle, Charlotte-Paige; Rosenberg, Eli S; Luisi, Nicole; Grey, Jeremy; Sanchez, Travis; Del Rio, Carlos; Peterson, John L; Frew, Paula M; Sullivan, Patrick S; Kelley, Colleen F

    2017-08-01

    PrEP willingness may be different among black and white men who have sex with men (MSM) given known disparities in HIV incidence, sociodemographic factors, and healthcare access between these groups. We surveyed 482 black and white HIV-negative MSM in Atlanta, GA about their willingness to use pre-exposure prophylaxis (PrEP) and facilitators and barriers to PrEP willingness. Overall, 45% (215/482) of men indicated interest in using PrEP. Engaging in recent unprotected anal intercourse (UAI) was the only factor significantly associated with PrEP willingness in multivariate analyses (OR 1.73, 95% CI 1.13, 2.65). Willing men identified "extra protection" against HIV as the most common reason for interest in using PrEP, whereas unwilling men most commonly cited not wanting to take medication daily, and this reason was more common among white MSM (42.3% of white MSM vs. 28.9% of black MSM, p = 0.04). Most men indicated willingness to use PrEP if cost was <50 dollars/month; however, more black MSM indicated willingness to use PrEP only if cost were free (17.9% of white MSM vs. 25.9% of black MSM, p = 0.03). Overall, these data are useful to scale up PrEP interventions targeting at-risk MSM in Atlanta and highlight the need for implementation of low cost-programs, which will be especially important for black MSM.

  16. Metropolitan siting: a historical perspective

    International Nuclear Information System (INIS)

    Bunch, D.F.

    1978-09-01

    The paper discusses the development and implementation of the Reactor Site Criteria and particularly the evolving posture of the agency on the subject of metropolitan siting. The review actions on nine sites are described to illustrate the various issues and positions and to clarify at least some of the bases for current practices of the NRC staff

  17. Derivation of Nationally Consistent Indices Representing Urban Intensity Within and Across Nine Metropolitan Areas of the Conterminous United States

    Science.gov (United States)

    Cuffney, Thomas F.; Falcone, James A.

    2009-01-01

    Two nationally consistent multimetric indices of urban intensity were developed to support studies of the effects of urbanization on streams in nine metropolitan areas of the conterminous United States: Atlanta, Georgia; Birmingham, Alabama; Boston, Massachusetts; Dallas-Fort Worth, Texas; Denver, Colorado; Milwaukee-Green Bay, Wisconsin; Portland, Oregon; Raleigh, North Carolina; and Salt Lake City, Utah. These studies were conducted as a part of the U.S. Geological Survey's National Water-Quality Assessment Program. These urban intensity indices were used to define gradients of urbanization and to interpret biological, physical, and chemical changes along these gradients. Ninety census, land-cover, and infrastructure variables obtained from nationally available databases were evaluated. Only variables that exhibited a strong and consistent linear relation with 2000 population density were considered for use in the indices. Housing-unit density (HUDEN), percentage of basin area in developed land (P_NLCD1_2), and road density (ROADDEN) were selected as the best representatives of census, land-cover, and infrastructure variables. The metropolitan area national urban intensity index (MA-NUII) was scaled to represent urban intensity within each metropolitan area and ranged from 0 (little or no urban) to 100 (maximum urban) for sites within each metropolitan area. The national urban intensity index (NUII) was scaled to represent urban intensity across all nine metropolitan areas and ranged from 0 to 100 for all sites. The rates at which HUDEN, P_NLCD1_2, and ROADDEN changed with changes in population density varied among metropolitan areas. Therefore, these variables were adjusted to obtain a more uniform rate of response across metropolitan areas in the derivation of the NUII. The NUII indicated that maximum levels of urban intensity occurred in the West and Midwest rather than in the East primarily because small inner-city streams in eastern metropolitan areas are

  18. Health impact assessment of the Atlanta BeltLine.

    Science.gov (United States)

    Ross, Catherine L; Leone de Nie, Karen; Dannenberg, Andrew L; Beck, Laurie F; Marcus, Michelle J; Barringer, Jason

    2012-03-01

    Although a health impact assessment (HIA) is a tool that can provide decision makers with recommendations to promote positive health impacts and mitigate adverse health impacts of proposed projects and policies, it is not routinely conducted on most major projects or policies. To make health a decision criterion for the Atlanta BeltLine, a multibillion-dollar transit, trails, parks, and redevelopment project. An HIA was conducted in 2005-2007 to anticipate and influence the BeltLine's effect on health determinants. Changes in access and equity, environmental quality, safety, social capital, and physical activity were forecast, and steps to maximize health benefits and reduce negative effects were recommended. Key recommendations included giving priority to the construction of trails and greenspace rather than residential and retail construction, making health an explicit goal in project priority setting, adding a public health professional to decision-making boards, increasing the connectivity between the BeltLine and civic spaces, and ensuring that affordable housing is built. BeltLine project decision makers have incorporated most of the HIA recommendations into the planning process. The HIA was cited in the awarding of additional funds of $7,000,000 for brownfield clean-up and greenspace development. The project is expected to promote the health of local residents more than in the absence of the HIA. This report is one of the first HIAs to tie specific assessment findings to specific recommendations and to identifiable impacts from those recommendations. The lessons learned from this project may help others engaged in similar efforts. Copyright © 2012. Published by Elsevier Inc.

  19. Urbanization effects on the hydrology of the Atlanta, Georgia (USA)

    Science.gov (United States)

    Peters, N.E.; Rose, S.

    2001-01-01

    For the period from 1958 to 1996, streamflow and rainfall characteristics of a highly urbanized watershed were compared with less-urbanized and non-urbanized watersheds in the vicinity of Atlanta, Georgia (USA). Water levels in several wells completed in surficial and crystalline-rock aquifers also were evaluated. Annual runoff coefficients (runoff as a fractional percentage of precipitation) ranged from 0.31 to 0.34 and were not significantly different for the urban stream (Peachtree Creek). Peak flows for the largest 25 stormflows at Peachtree Creek were 30% to 80% greater than peak flows for the other streams. A 2-day storm recession constant for Peachtree Creek was much larger, that is streamflow decreased more rapidly than for the other streams. Average low flow of Peachtree Creek was 25 to 35% less than the other streams, possibly the result of decreased infiltration caused by the more efficient routing of storm water and the paving of groundwater recharge areas. The timing of groundwater level variations was similar annually in each well, reflecting the seasonal recharge. Although water level monitoring only began during the late 1970s and early 1980s for the two urban wells, water levels in these wells have been declining compared to non-urban wells since then. The water level decline is attributed to decreased groundwater recharge in the urban watersheds due to increased imperviousness and related rapid storm runoff. Likewise, the increased urbanization from the 1960s to the 1990s of the Peachtree Creek watershed produced more runoff than urbanization in the less urbanized Big Creek and Sweetwater Creek watersheds.

  20. Fusion of multisource and multiscale remote sensing data for water availability assessment in a metropolitan region

    Science.gov (United States)

    Chang, N. B.; Yang, Y. J.; Daranpob, A.

    2009-09-01

    Recent extreme hydroclimatic events in the United States alone include, but are not limited to, the droughts in Maryland and the Chesapeake Bay area in 2001 through September 2002; Lake Mead in Las Vegas in 2000 through 2004; the Peace River and Lake Okeechobee in South Florida in 2006; and Lake Lanier in Atlanta, Georgia in 2007 that affected the water resources distribution in three states - Alabama, Florida and Georgia. This paper provides evidence from previous work and elaborates on the future perspectives that will collectively employ remote sensing and in-situ observations to support the implementation of the water availability assessment in a metropolitan region. Within the hydrological cycle, precipitation, soil moisture, and evapotranspiration can be monitored by using WSR-88D/NEXRAD data, RADARSAT-1 images, and GEOS images collectively to address the spatiotemporal variations of quantitative availability of waters whereas the MODIS images may be used to track down the qualitative availability of waters in terms of turbidity, Chlorophyll-a and other constitutes of concern. Tampa Bay in Florida was selected as a study site in this analysis, where the water supply infrastructure covers groundwater, desalination plant, and surface water at the same time. Research findings show that through the proper fusion of multi-source and multi-scale remote sensing data for water availability assessment in metropolitan region, a new insight of water infrastructure assessment can be gained to support sustainable planning region wide.

  1. Green roof adoption in atlanta, georgia: the effects of building characteristics and subsidies on net private, public, and social benefits.

    Science.gov (United States)

    Mullen, Jeffrey D; Lamsal, Madhur; Colson, Greg

    2013-10-01

    This research draws on and expands previous studies that have quantified the costs and benefits associated with conventional roofs versus green roofs. Using parameters from those studies to define alternative scenarios, we estimate from a private, public, and social perspective the costs and benefits of installing and maintaining an extensive green roof in Atlanta, GA. Results indicate net private benefits are a decreasing function of roof size and vary considerably across scenarios. In contrast, net public benefits are highly stable across scenarios, ranging from $32.49 to $32.90 m(-2). In addition, we evaluate two alternative subsidy regimes: (i) a general subsidy provided to every building that adopts a green roof and (ii) a targeted subsidy provided only to buildings for which net private benefits are negative but net public benefits are positive. In 6 of the 12 general subsidy scenarios the optimal public policy is not to offer a subsidy; in 5 scenarios the optimal subsidy rate is between $20 and $27 m(-2); and in 1 scenario the optimal rate is $5 m(-2). The optimal rate with a targeted subsidy is between $20 and $27 m(-2) in 11 scenarios and no subsidy is optimal in the twelfth. In most scenarios, a significant portion of net public benefits are generated by buildings for which net private benefits are positive. This suggests a policy focused on information dissemination and technical assistance may be more cost-effective than direct subsidy payments.

  2. Premises for Shaping Metropolitan Areas in Romania

    Directory of Open Access Journals (Sweden)

    RAULARIAN RUSU

    2012-01-01

    Full Text Available The setting up of metropolitan areas is a process which is still in progress in Romania. The legislative framework for the creation of these areas has been built up only since 2001, and there are still a number of juridical inconsistencies concerning the association of administrative units to form metropolitan areas. On the other hand, political reasons and the fear of losing a certain degree of authority and to become subordinates of the large cities (in the case of rural municipalities also hindered the development of metropolitan areas in Romania. Nevertheless, the metropolitan areas already in existence are running a number of projects that are beneficial for most members of the association. Such positive examples may trigger the creation of the other metropolitan areas. Although the existing metropolitan areas did not yield spectacular results, the time passed since their foundation is yet too short to correctly assess their usefulness and territorial meaning. For the moment, the following metropolitan areas exist in Romania: Iaşi, Oradea, Braşov, Constanţa, Bacău, Cluj-Napoca, Târgu Mureş and Craiova. Bucharest, Timişoara, Ploieşti and Galaţi-Brăila metropolitan areas are still in process of setting up.

  3. Newcastle disease B1 vaccine strain in wild rock pigeons in Atlanta, Georgia

    Science.gov (United States)

    From June to October of 2012, samples were collected from wild Rock Pigeons (Columba livia) in urban neighborhoods of Atlanta, Georgia to ascertain the prevalence of pigeon paramyxovirus serotype-1 (PPMV-1). PPMV-1 strains are a subset of avian paramyxovirus serotype-1 (APMV-1) commonly isolated fro...

  4. 77 FR 24440 - Approval and Promulgation of Implementation Plans; Georgia; Atlanta; Ozone 2002 Base Year...

    Science.gov (United States)

    2012-04-24

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R04-OAR-2010-0021(b); FRL-9661-9] Approval and Promulgation of Implementation Plans; Georgia; Atlanta; Ozone 2002 Base Year Emissions Inventory AGENCY... 2002 base year emissions inventory portion of the state implementation plan (SIP) revision submitted by...

  5. 77 FR 24399 - Approval and Promulgation of Implementation Plans; Georgia; Atlanta; Ozone 2002 Base Year...

    Science.gov (United States)

    2012-04-24

    ... Promulgation of Implementation Plans; Georgia; Atlanta; Ozone 2002 Base Year Emissions Inventory AGENCY... approve the ozone 2002 base year emissions inventory, portion of the state implementation plan (SIP... technology (RACT), contingency measures, a 2002 base- year emissions inventory and other planning SIP...

  6. PREFACE TO SPECIAL SECTION: SOUTHERN OXIDANTS STUDY 1999 ATLANTA SUPERSITE PROJECT (SOS3)

    Science.gov (United States)

    The Atlanta Supersites Project consisted of a one-month intensive field program to compare advanced methods for measurement of PM2.5 mass, chemical composition, including single particle composition in real-time, and aerosol precursor species. The project was the first of EPA's ...

  7. Overkill: Black Lives and the Spectacle of the Atlanta Cheating Scandal

    Science.gov (United States)

    Royal, Camika; Dodo Seriki, Vanessa

    2018-01-01

    This article examines the 2015 Atlanta cheating scandal trials and sentencing. Using critical race theory, the authors argue that cheating is a natural outgrowth of market-based school reform and that racial realism will always lead to scrutiny of Black performance. The sentences of these Black educators is overkill, rooted in anti-Blackness, and…

  8. Comparison of Daytime and Nighttime Populations Adjacent to Interstate Highways in Metropolitan Areas Using LandScan USA

    International Nuclear Information System (INIS)

    Johnson, Paul E

    2007-01-01

    An article of similar title was published in the International Journal of Radioactive Materials Transport in 1999. The study concluded that the daytime and nighttime populations are not substantially different for the metropolitan areas examined. This study revisits the issue, but using the LandScan USA high resolution population distribution data, which includes daytime and night-time population. Segments of Interstate highway beltways, along with the direct route through the city, for Atlanta, St. Louis, and Kansas City are examined with an 800m buffer from either side of the highways. The day/night ratio of population is higher using the LandScan USA data. LandScan USA daytime and night-time data will be incorporated into the TRAGIS routing model in future

  9. Impacts of Combined Cooling, Heating and Power Systems, and Rainwater Harvesting on Water Demand, Carbon Dioxide, and NOx Emissions for Atlanta.

    Science.gov (United States)

    James, Jean-Ann; Sung, Sangwoo; Jeong, Hyunju; Broesicke, Osvaldo A; French, Steven P; Li, Duo; Crittenden, John C

    2018-01-02

    The purpose of this study is to explore the potential water, CO 2 and NO x emission, and cost savings that the deployment of decentralized water and energy technologies within two urban growth scenarios can achieve. We assess the effectiveness of urban growth, technological, and political strategies to reduce these burdens in the 13-county Atlanta metropolitan region. The urban growth between 2005 and 2030 was modeled for a business as usual (BAU) scenario and a more compact growth (MCG) scenario. We considered combined cooling, heating and power (CCHP) systems using microturbines for our decentralized energy technology and rooftop rainwater harvesting and low flow fixtures for the decentralized water technologies. Decentralized water and energy technologies had more of an impact in reducing the CO 2 and NO x emissions and water withdrawal and consumption than an MCG growth scenario (which does not consider energy for transit). Decentralized energy can reduce the CO 2 and NO x emissions by 8% and 63%, respectively. Decentralized energy and water technologies can reduce the water withdrawal and consumption in the MCG scenario by 49% and 50% respectively. Installing CCHP systems on both the existing and new building stocks with a net metering policy could reduce the CO 2 , NO x , and water consumption by 50%, 90%, and 75% respectively.

  10. Water, Air Emissions, and Cost Impacts of Air-Cooled Microturbines for Combined Cooling, Heating, and Power Systems: A Case Study in the Atlanta Region

    Directory of Open Access Journals (Sweden)

    Jean-Ann James

    2016-12-01

    Full Text Available The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power (CCHP systems have the potential to improve the energy generation efficiency of a city or urban region by providing energy for heating, cooling, and electricity simultaneously. The purpose of this study is to estimate the water consumption for energy generation use, carbon dioxide (CO2 and NOx emissions, and economic impact of implementing CCHP systems for five generic building types within the Atlanta metropolitan region, under various operational scenarios following the building thermal (heating and cooling demands. Operating the CCHP system to follow the hourly thermal demand reduces CO2 emissions for most building types both with and without net metering. The system can be economically beneficial for all building types depending on the price of natural gas, the implementation of net metering, and the cost structure assumed for the CCHP system. The greatest reduction in water consumption for energy production and NOx emissions occurs when there is net metering and when the system is operated to meet the maximum yearly thermal demand, although this scenario also results in an increase in greenhouse gas emissions and, in some cases, cost. CCHP systems are more economical for medium office, large office, and multifamily residential buildings.

  11. Broadband availability in metropolitan and non-metropolitan Pennsylvania

    Directory of Open Access Journals (Sweden)

    Lawrence E. Wood

    2016-09-01

    Full Text Available Over the past few years having a broadband connection has become essential for many Internet activities. As broadband increases in importance, it becomes imperative to assess how its use and availability may vary, especially in relation to issues such as geographic location. For rural areas in particular, the availability of broadband service is especially important. This research assesses broadband service availability in rural areas of Pennsylvania, USA. In particular, it examines the extent to which Digital Subscriber Line (DSL and broadband cable modem services are being deployed throughout rural Pennsylvania. It compares this deployment with the availability of such services in the state’s urban and metropolitan areas. The results of this research suggest that there is a “digital divide” in terms of broadband availability between rural and urban areas of Pennsylvania. However, this “divide” is perhaps not as wide as might be expected. Thus, as broadband is becoming increasingly available in rural areas of the U.S. and throughout much of the rest of the world, this research concludes that while research must remain vigilant in terms of assessing advanced telecommunications availability in rural areas, future research should also be sure to focus on how such technologies can be used to promote economic and social concerns, including in relation to building online networks and diminishing social and professional isolation in rural areas.

  12. Metropolitan Optical Networks 1995 Annual Report

    DEFF Research Database (Denmark)

    Kristensen, Martin; Jouanno, Jean-Marc; Malone, Kevin

    1996-01-01

    The annual report describes the research carried out in the ACTS-project METON (Metropolitan Optical Networks) in 1995. L.M. Ericsson is prime contractor and 12 partners including DTU is involved in the project.......The annual report describes the research carried out in the ACTS-project METON (Metropolitan Optical Networks) in 1995. L.M. Ericsson is prime contractor and 12 partners including DTU is involved in the project....

  13. Metropolitan Optical Networks 1996 Annual Report

    DEFF Research Database (Denmark)

    Kristensen, Martin; Jouanno, Jean-Marc; Malone, Kevin

    1997-01-01

    The report desribes the reasearch carried out in the ACTS-project METON (Metropolitan Optical Networks) in 1996. L.M. Ericsson is prime contractor and 12 partners are involved in the project including DTU, i.e. EMI and MIC.......The report desribes the reasearch carried out in the ACTS-project METON (Metropolitan Optical Networks) in 1996. L.M. Ericsson is prime contractor and 12 partners are involved in the project including DTU, i.e. EMI and MIC....

  14. Describing Peripancreatic Collections According to the Revised Atlanta Classification of Acute Pancreatitis An International Interobserver Agreement Study

    NARCIS (Netherlands)

    Bouwense, Stefan A.; van Brunschot, Sandra; van Santvoort, Hjalmar C.; Besselink, Marc G.; Bollen, Thomas L.; Bakker, Olaf J.; Banks, Peter A.; Boermeester, Marja A.; Cappendijk, Vincent C.; Carter, Ross; Charnley, Richard; van Eijck, Casper H.; Freeny, Patrick C.; Hermans, John J.; Hough, David M.; Johnson, Colin D.; Laméris, Johan S.; Lerch, Markus M.; Mayerle, Julia; Mortele, Koenraad J.; Sarr, Michael G.; Stedman, Brian; Vege, Santhi Swaroop; Werner, Jens; Dijkgraaf, Marcel G.; Gooszen, Hein G.; Horvath, Karen D.; Aghdassi, Ali A.; van Enckevort, Conny C.; de Haas, Robbert J.; Horsthuis, Karin; van der Jagt, Michel F.; Kok, Niels F.; Koopmanschap, Desirée H.; Koppe, Manuel J.; Krak, Nanda C.; Lane, Charlotte E.; Lee, Jean H.; de Lussanet, Q.; Saunders, Michael D.; Swaroop Vege, Santhi; van der Vlugt, Manon; van Wageningen, Bas; Wassenaar, Eelco; van Wely, Bob J.; Wijnhoven, Bas P.

    2017-01-01

    Objectives: Severe acute pancreatitis is associated with peripancreatic morphologic changes as seen on imaging. Uniform communication regarding these morphologic findings is crucial for accurate diagnosis and treatment. For the original 1992 Atlanta classification, interobserver agreement is poor.

  15. Summary of Needs and Opportunities from the 2011 Residential Energy Efficiency Stakeholders Meeting: Atlanta, Georgia -- March 16-18, 2011

    Energy Technology Data Exchange (ETDEWEB)

    2011-05-01

    This summary report outlines needs and issues for increasing energy efficiency of new and existing U.S homes, as identified at the U.S Department of Energy Building America program Spring 2011 stakeholder meeting in Atlanta, Georgia.

  16. Atlanta Gas Light opts for an in-house AM/FM

    International Nuclear Information System (INIS)

    Hull, S.R.

    1993-01-01

    Atlanta Gas Light Co. has completed facilities conversion for the first of nine planned implementations of its automated mapping/facilities management mapping/facilities management system, the Facilities and Land Base Automated Mapping Environment or FLAME. Facilities conversion is generally the most costly and time-consuming phase of an AM/FM project. Many companies decide to rely totally on outside expertise for this phase because of the complexity of the process an the resources required to complete it. Atlanta Gas Light decided to take an alternate approach by performing the facilities conversion process in-house for the first implementation, than having an outside vendor carrying out a future implementation and compare the two

  17. Fútbol, etnicidad y otredad: el Club Atlético Atlanta de Buenos Aires

    Directory of Open Access Journals (Sweden)

    Raanan Rein

    2014-06-01

    While most historians would agree as to the centrality of soccer in Latin American societies, very little has been written on ethnicity and sports in such immigrant societies as Argentina and Brazil. This article focuses on the Club Atlético Atlanta, located in the neighborhood of Villa Crespo. Although populated by various ethnic groups, Villa Crespo has long been considered a Jewish neighborhood. During the second half of the 20th century, there has been a conspicuous Jewish presence among the fans, administrators and presidents of the Atlanta soccer club, to the extent that fans of rival teams often chant anti-Semitic slogans during matches. For the first immigrant generation, belonging to this club was a way of becoming Argentines. For the next generation, it was a way of maintaining ethnic Jewish identity, while for the third it has become a family tradition.

  18. Muchinako, GA

    African Journals Online (AJOL)

    Muchinako, GA. Vol 28, No 2 (2013) - Articles Children living and/or working on the streets in Harare: Issues and challenges. Abstract. ISSN: 1012-1080. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of ...

  19. Metropolitan planning from an international comparative perspective

    DEFF Research Database (Denmark)

    Galland, Daniel; Grønning, Marius

    2016-01-01

    policies, and thus also to the instrumental orientation within planning. A challenge stemming from this comparison is to understand how similar policies are implemented at a strategic and metropolitan level. Within the institutional framework of Copenhagen, the problem with the Finger Plan directive might...... (Faludi & van der Valk, 1994), thus integrating the archetypal land-use character of municipal plans and the strategic and growth-oriented pursuit of regional plans. A number of questions may be deduced: How explicit is the metropolitan scale? How local and how regional is the knowledge basis? Within......Over the last few years new practices of spatial strategy making at different planning scales have emerged. At the metropolitan level, such spatial strategies are reminiscent of national and supranational competitive strategies (e.g. EU policies) as well as ratifications of international...

  20. 76 FR 45771 - Foreign-Trade Zone 26-Atlanta, GA; Application for Manufacturing Authority; Makita Corporation of...

    Science.gov (United States)

    2011-08-01

    ... bits; socket wrenches; styrene polymers; polyamides; resins; caulk; glues and adhesives; vinyl cases; vinyl tubes; labels; plastic bags; water tanks; plastic grips; rubber knobs and handles; plastic cases... examiner to evaluate and analyze the facts and information presented in the application and case record and...

  1. American Studies Association — Crossroads of Cultures, Atlanta, Ga., Nov. 11-14, 2004

    OpenAIRE

    Pothier, Jacques

    2006-01-01

    Dans le cadre de son congrès annuel et à l’initiative de sa présidente en exercice, Shelley Fisher Fishkin, l’American Studies Association avait lancé une International Initiative : inviter les représentants de toutes les associations d’études américaines du monde. Parallèlement, American Quarterly, la revue de l’Association, invitait les directeurs des rédactions des revues américanistes.Je représentais donc l’AFEA, la RFEA et Transatlantica.Qu’est-ce que l’American Studies Association ?Le C...

  2. Changing Housing Patterns in Metropolitan Washington

    Science.gov (United States)

    Grier, George; Grier, Eunice

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights in May 1974, summarizes extensive studies of changing minority residential patterns in metropolitan Washington and less extensive studies of other groups; the prospects for future desegregation and for using the growing economic potential of minority families…

  3. Engaging with sustainability issues in metropolitan Chennai

    NARCIS (Netherlands)

    Kennedy, L.; Varrel, A.; Denis, E.; Dupont, V.; Dhanalakshmi, R.; Roumeau, S.; Baud, I.; Pfeffer, K.; Sridharan, N.; Vijayabaskar, M.; Suresh Babu, M.; Seifelislam, A.; Rouanet, H.; Saharan, T.

    2014-01-01

    Chennai is the largest metropolitan city in South India (8.7 million in 2011) and the provincial capital of the large state of Tamil Nadu (population 72 million in 2011). Before that, under British rule, the city was the capital of the Madras Presidency, and was known as Madras until 1996, when the

  4. Kansas City Metropolitan Community Colleges. Audit Report.

    Science.gov (United States)

    Missouri Office of the State Auditor, Jefferson City.

    This audit report reviews the employment contracts, related compensation, and other benefits provided for the chancellor and other officers of the Kansas City Metropolitan Community Colleges (KCMCC) in Missouri. The chancellor is allowed to either solicit bids or negotiate for contracted services such as architects, construction managers,…

  5. Reconceptualization Sexuality and Rethinking Homophobia in Metropolitan Campus Spaces

    Science.gov (United States)

    Deniz, Caglar

    2017-01-01

    The Metropolitan city gives non-metropolitan students an opportunity to meet new social groups. In this article, the perceptions of sexuality of those students who come from provincial areas to a metropolitan city for university education are examined within a framework of semi-structured interviews. The study on which this article is based used a…

  6. Spatial variations in US poverty: beyond metropolitan and non-metropolitan.

    Science.gov (United States)

    Wang, Man; Kleit, Rachel Garshick; Cover, Jane; Fowler, Christopher S

    2012-01-01

    Because poverty in rural and urban areas of the US often has different causes, correlates and solutions, effective anti-poverty policies depend on a thorough understanding of the ruralness or urbanness of specific places. This paper compares several widely used classification schemes and the varying magnitudes of poverty that they reveal in the US. The commonly used ‘metropolitan/non-metropolitan’ distinction obscures important socioeconomic differences among metropolitan areas, making our understanding of the geography of poverty imprecise. Given the number and concentration of poor people living in mixed-rural and rural counties in metropolitan regions, researchers and policy-makers need to pay more nuanced attention to the opportunities and constraints such individuals face. A cross-classification of the Office of Management and Budget’s metro system with a nuanced RUDC scheme is the most effective for revealing the geographical complexities of poverty within metropolitan areas.

  7. Ensemble simulations to study the impact of land use change of Atlanta to regional climate

    Science.gov (United States)

    Liu, P.; Hu, Y.; Stone, B.; Vargo, J.; Nenes, A.; Russell, A.; Trail, M.; Tsimpidi, A.

    2012-12-01

    Studies show that urban areas may be the "first responders" to climate change (Rosenzweig et al., 2010). Of particular interest is the potential increased temperatures in urban areas, due to use of structures and surfaces that increase local heating, and how that may impact health, air quality and other environmental factors. In response, interest has grown as to how the modification of land use in urban areas, in order to mitigate the adverse effects of urbanization can serve to reduce local temperatures, and how climate is impacted more regionally. Studies have been conducted to investigate the impact of land use change on local or regional climate by dynamic downscaling using regional climate models (RCMs), the boundary conditions (BCs) and initial conditions (ICs) of which result from coarser-resolution reanalysis data or general circulation models (GCMs). However, few studies have focused on demonstrating whether the land use change in local areas significantly impacts the climate of the larger region of the domain, and the spatial scale of the impact from urban-scale changes. This work investigated the significance of the impact of land use change in the Atlanta city area on different scales, using a range of modeling resolutions, including the contiguous US (with 36km resolution), the southeastern US (with 12km resolution) and the state of Georgia (with 4km resolution). We used WRF version 3.1.1 with and ran continuous from June to August of a simulated year 2050, driven by GISS ModelE with inputs corresponding to RCP4.5. During the simulation, spectral nudging is used in the 36km resolution domain to maintain the climate patterns with scales larger than 2000km. Two-way nesting is also used in order to take into account the feedback of nesting domains across model domains. Two land use cases over the Atlanta city are chosen. For the base case, most of the urban area of Atlanta is covered with forest; while for the second, "impervious" case, all the urban

  8. Reassessment of biogenic volatile organic compound emissions in the Atlanta area

    International Nuclear Information System (INIS)

    Geron, C.D.; Pierce, T.E.; Guenther, A.B.

    1995-01-01

    Localized estimates of biogenic volatile organic compound (BVOC) emissions are important inputs for photochemical oxidant simulation models. Since forest tree species are the primary emitters of BVOCs, it is important to develop reliable estimates of their areal coverage and BVOC emission rates. A new system is used to estimate these emissions in the Atlanta area for specific tree genera at hourly and county levels. The U.S. Department of Agriculture, Forest Service Forest Inventory and Analysis data and an associated urban vegetation survey are used to estimate canopy occupancy by genus in the Atlanta area. A simple canopy model is used to adjust photosynthetically active solar radiation at five vertical levels in the canopy. Lraf temperature and photosynthetically active radiation derived from ambient conditions above the forest canopy are then used to drive empirical equations to estimate genus level emission rates of BVOCs vertically through forest canopies. These genera-level estimates are then aggregated to county and regional levels for input into air quality models and for comparison with (1) the regulatory model currently used and (2) previous estimates for the Atlanta area by local researchers. Estimated hourly emissions from the three approaches during a documented ozone event day are compared. The proposed model yields peak diurnal isoprene emission rates that are over a factor of three times higher than previous estimates. This results in total BVOC emission rates that are roughly a factor of two times higher than previous estimates. These emissions are compared with observed emissions from forests of similar composition. Possible implications for oxidant events are discussed. (author)

  9. Consumer Willingness to Pay a Premium for Halal Goat Meat: A Case from Atlanta, Georgia

    OpenAIRE

    Ibrahim, Mohammed

    2011-01-01

    The growth in goat meat demand is attributed to the influx of immigrants from goat-meat-eating countries into the U.S. This Paper examines the willingness to pay a premium for halal goat meat. The factors that significantly impact the willingness to pay a premium for halal goat meat in Atlanta include income, current consumption, household size, and marital status. Results suggest that the mean willingness to pay a premium for the halal attribute is 50 cents per pound of goat meat.

  10. Using synoptic weather types to predict visitor attendance at Atlanta and Indianapolis zoological parks

    Science.gov (United States)

    Perkins, David R.

    2018-01-01

    Defining an ideal "tourism climate" has been an often-visited research topic where explanations have evolved from global- to location-specific indices tailored to tourists' recreational behavior. Unfortunately, as indices become increasingly specific, they are less translatable across geographies because they may only apply to specific activities, locales, climates, or populations. A key need in the future development of weather and climate indices for tourism has been a translatable, meteorologically based index capturing the generalized ambient atmospheric conditions yet considering local climatology. To address this need, this paper tests the applicability of the spatial synoptic classification (SSC) as a tool to predict visitor attendance response in the tourism, recreation, and leisure (TRL) sector across different climate regimes. Daily attendance data is paired with the prevailing synoptic weather condition at Atlanta and Indianapolis zoological parks from September 2001 to June 2011, to review potential impacts ambient atmospheric conditions may have on visitor attendances. Results indicate that "dry moderate" conditions are most associated with high levels of attendance and "moist polar" synoptic conditions are most associated with low levels of attendance at both zoological parks. Comparing visitor response at these zoo locations, visitors in Indianapolis showed lower levels of tolerance to synoptic conditions which were not "ideal." Visitors in Indianapolis also displayed more aversion to "polar" synoptic regimes while visitors in Atlanta displayed more tolerance to "moist tropical" synoptic regimes. Using a comprehensive atmospheric measure such as the SSC may be a key to broadening application when assessing tourism climates across diverse geographies.

  11. Metropolitan Quantum Key Distribution with Silicon Photonics

    Directory of Open Access Journals (Sweden)

    Darius Bunandar

    2018-04-01

    Full Text Available Photonic integrated circuits provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD encoder in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 1.039 Mbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB and 157 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss. Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate photonic integrated circuits as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks.

  12. Metropolitan Quantum Key Distribution with Silicon Photonics

    Science.gov (United States)

    Bunandar, Darius; Lentine, Anthony; Lee, Catherine; Cai, Hong; Long, Christopher M.; Boynton, Nicholas; Martinez, Nicholas; DeRose, Christopher; Chen, Changchen; Grein, Matthew; Trotter, Douglas; Starbuck, Andrew; Pomerene, Andrew; Hamilton, Scott; Wong, Franco N. C.; Camacho, Ryan; Davids, Paul; Urayama, Junji; Englund, Dirk

    2018-04-01

    Photonic integrated circuits provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) encoder in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 1.039 Mbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 157 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate photonic integrated circuits as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks.

  13. Air pollution holiday effect in metropolitan Kaohsiung

    Science.gov (United States)

    Tan, P.; Chen, P. Y.

    2014-12-01

    Different from Taipei, the metropolitan Kaohsiung which is a coastal and industrial city has the major pollution sources from stationary sources such as coal-fired power plants, petrochemical facilities and steel plants, rather than mobile sources. This study was an attempt to conduct a comprehensive and systematical examination of the holiday effect, defined as the difference in air pollutant concentrations between holiday and non-holiday periods, over the Kaohsiung metropolitan area. We documented evidence of a "holiday effect", where concentrations of NOx, CO, NMHC, SO2 and PM10 were significantly different between holidays and non-holidays, in the Kaohsiung metropolitan area from daily surface measurements of seven air quality monitoring stations of the Taiwan Environmental Protection Administration during the Chinese New Year (CNY) and non-Chinese New Year (NCNY) periods of 1994-2010. Concentrations of the five pollutants were lower in the CNY than in the NCNY period, however, that of O3 was higher in the CNY than in the NCNY period and had no holiday effect. The exclusion of the bad air quality day (PSI > 100) and the Lantern Festival Day showed no significant effects on the holiday effects of air pollutants. Ship transportation data of Kaohsiung Harbor Bureau showed a statistically significant difference in the CNY and NCNY period. This difference was consistent with those found in air pollutant concentrations of some industrial and general stations in coastal areas, implying the possible impact of traffic activity on the air quality of coastal areas. Holiday effects of air pollutants over the Taipei metropolitan area by Tan et al. (2009) are also compared.

  14. Green Infrastructure Concept for JABODETABEKJUR Metropolitan Area

    Science.gov (United States)

    Tanuwidjaja, Gunawan; Gates Chang, Bill

    2017-07-01

    Sixty “Mega Cities” would emerge by 2015 catering of 600 million populations, and were threatened by the climate change, because of cyclones, flooding, etc. Jakarta became a metro region covering Jakarta, Bogor, Tangerang, Bekasi, Depok and Cianjur. Jakarta metropolitan faced the very high population growth, urban sprawling, traffic jams, flooding, green open space reduction, environmental degradation, urban slums and illegal street hawkers. Flooding and traffic congestions were the two most important issues to solve. SWOT analysis and urban design solutions were produced to create a sustainable solution. Related to transportation issues, Singapore Mass Rapid Transport (MRT) concept was evaluated. Meanwhile the Netherlands’ polder concept as well as Singapore’s Integrated Water Management were also analyzed. The development of above ground MRT as well as Busway could be developed to connect Jakarta Metropolitan Region. The networks were developed on the main toll road networks. The MRT and Busway would eventually replace the need of automobile use in the future. The Transit - Oriented - Development (TOD) with high density can be suggested to be concentrated nearby the MRT and Busway interchange stations. The Netherlands’ polder and were adopted for urban’ low-lying lands in Jakarta Metropolitan Region, A polder system was defined as the Integrated Man-made Drainage System consisting Dikes, Drains, Retention Ponds, Outfall Structures or Pumping Stations. The polder system was proposed to be extended to Tangerang and Bekasi area.

  15. 78 FR 28940 - Environmental Impact Statement for the Atlanta to Charlotte Portion of the Southeast High Speed...

    Science.gov (United States)

    2013-05-16

    ... federal High-Speed Intercity Passenger Rail (HSIPR) program and includes the development of a Passenger.... Background The Atlanta-Charlotte Corridor faces mobility challenges. Transportation demand and travel growth... travel time and reliability, provide another reliable mode choice, create jobs, reduce dependence on...

  16. Describing Peripancreatic Collections According to the Revised Atlanta Classification of Acute Pancreatitis: An International Interobserver Agreement Study.

    Science.gov (United States)

    Bouwense, Stefan A; van Brunschot, Sandra; van Santvoort, Hjalmar C; Besselink, Marc G; Bollen, Thomas L; Bakker, Olaf J; Banks, Peter A; Boermeester, Marja A; Cappendijk, Vincent C; Carter, Ross; Charnley, Richard; van Eijck, Casper H; Freeny, Patrick C; Hermans, John J; Hough, David M; Johnson, Colin D; Laméris, Johan S; Lerch, Markus M; Mayerle, Julia; Mortele, Koenraad J; Sarr, Michael G; Stedman, Brian; Vege, Santhi Swaroop; Werner, Jens; Dijkgraaf, Marcel G; Gooszen, Hein G; Horvath, Karen D

    2017-08-01

    Severe acute pancreatitis is associated with peripancreatic morphologic changes as seen on imaging. Uniform communication regarding these morphologic findings is crucial for accurate diagnosis and treatment. For the original 1992 Atlanta classification, interobserver agreement is poor. We hypothesized that for the revised Atlanta classification, interobserver agreement will be better. An international, interobserver agreement study was performed among expert and nonexpert radiologists (n = 14), surgeons (n = 15), and gastroenterologists (n = 8). Representative computed tomographies of all stages of acute pancreatitis were selected from 55 patients and were assessed according to the revised Atlanta classification. The interobserver agreement was calculated among all reviewers and subgroups, that is, expert and nonexpert reviewers; interobserver agreement was defined as poor (≤0.20), fair (0.21-0.40), moderate (0.41-0.60), good (0.61-0.80), or very good (0.81-1.00). Interobserver agreement among all reviewers was good (0.75 [standard deviation, 0.21]) for describing the type of acute pancreatitis and good (0.62 [standard deviation, 0.19]) for the type of peripancreatic collection. Expert radiologists showed the best and nonexpert clinicians the lowest interobserver agreement. Interobserver agreement was good for the revised Atlanta classification, supporting the importance for widespread adaption of this revised classification for clinical and research communications.

  17. Teacher Morale in the Atlanta Public Schools: Spring 1990. Report No. 4, Volume 25, 11/91.

    Science.gov (United States)

    Fraser, Lowrie A.

    A study was done of Atlanta (Georgia) public school teacher morale in May of 1990. About 40 percent of the teaching staff (1,520 teachers) voluntarily completed a 91-item questionnaire that contained subsets of questions from the Maslach Burnout Inventory and three subscales of emotional exhaustion, departmentalization, and personal…

  18. 78 FR 65877 - Approval and Promulgation of Implementation Plans; Atlanta, Georgia 1997 8-Hour Ozone...

    Science.gov (United States)

    2013-11-04

    ... mobile emissions), and Georgia projected the majority of its reductions to be from on-road and non-road mobile emissions. Notwithstanding the relatively small contribution of the Rule (jjj) emission reductions... 6/17/96 4/26/99. and HOV Marketing Program. Metropolitan Area. HOV lanes on I-75 and I-85...

  19. African urbanization in metropolitan South Africa--differential urbanization perspectives.

    Science.gov (United States)

    Geyer, H S

    1993-07-01

    "As a potentially important urban development policy consideration, attention is focused in this paper on differential urbanization trends in South Africa at the metropolitan level. Recent informal urban settlement patterns of the African population within the major metropolitan areas are contrasted against these differential urbanization trends to determine the implications of both for residential development in the metropolitan areas during the post-apartheid era." excerpt

  20. Atlanta 10 x 20 NTMS area: Alabama and Georgia. Data report

    International Nuclear Information System (INIS)

    Jones, P.L.

    1979-08-01

    Results of ground water and stream sediment reconnaissance in the National Topographic Map Series (NTMS) Atlanta 1 0 x 2 0 quadrangle are presented. Stream sediment samples were collected from small streams at 1312 sites or at a nominal density of one site per 13 square kilometers in rural areas. Ground water samples were collected at 951 sites or at a nominal density of one site per 18 square kilometers. Neutron activation analysis results are given for uranium and 16 other elements in sediments, and for uranium and 8 other elements in ground water and surface water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Statistical summaries of data and a brief description of results are given. A generalized geologic map and a summary of the geology of the area are included

  1. Minority Stress and Intimate Partner Violence Among Gay and Bisexual Men in Atlanta.

    Science.gov (United States)

    Stephenson, Rob; Finneran, Catherine

    2017-07-01

    Intimate partner violence (IPV) rates are disproportionately high among sexual minority populations. Few studies have examined the plausible relationship between minority stress and IPV among men who have sex with men. This study examines the associations between IPV and three indicators of minority stress: internalized homophobia, sexuality-based discrimination, and racism, in a large venue-based sample of gay and bisexual men from Atlanta, USA. Each of the minority stress measures was found to be significantly associated with increased odds of self-reporting any form of receipt of IPV. Significant associations were also identified between perpetration of IPV and minority stressors, with most types of IPV perpetration linked to internalized homophobia. This study confirms findings in a growing body of research supporting the relationship between minority stress and increased prevalence of IPV among men who have sex with men, and points to the need to address structural factors in IPV prevention programs for male-male couples.

  2. Islam in Diaspora: Shari’a Law, Piety and Brotherhood at al-Farooq Mosque, Atlanta

    Directory of Open Access Journals (Sweden)

    Mohamad Abdun Nasir

    2016-06-01

    [Tulisan ini mengkaji praktik ritual shalat hari raya (Eid di masjid al-Farooq Atlanta, Amerika Serikat pada kalangan muslim perantauan dari berbagai belahan dunia. Kajian ini, dengan menggunakan pendekatan tektual dan etnografi, mengamati penerapan hukum Islam dalam hal peribadatan dan pemaknaan serta pengalaman ritual diantara mereka. Studi ini menunjukkan bahwa shalat hari raya memberi makna dan pengalaman khusus. Perayaan ini dilihat sebagai medium untuk menunjukkan kesalehan dan menguatkan ikatan persaudaraan sesama muslim meskipun mempunyai latar belakang etnik dan budaya yang berbeda. Meskipun demikian, inti dari ritual tersebut menunjukkan aliran mazhab Hanafi. Pelaksanaan fiqih dalam sholat Eid tetap berpegang pada Qur’an dan Hadits. Dengan kata lain, konteks geografi dan budaya yang berbeda telah membentuk makna baru namun tetap tidak merubah inti dari praktik ibadah yang bermazhab Hanafi.

  3. Labor Force Activity of Women in Metropolitan and Nonmetropolitan America. Rural Development Research Report No. 15.

    Science.gov (United States)

    Brown, David L.; O'Leary, Jeanne M.

    Between 1960 and 1970 economic opportunity and progress for women in American non-metropolitan areas was mixed. While women in metropolitan areas were more likely to be labor force members than were non-metropolitan women, the difference in metropolitan and non-metropolitan labor force participation rates narrowed during the period. For women…

  4. Helsinki Metropolitan Area Climate Change Adaptation Strategy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    The Helsinki Metropolitan Area Climate Change Adaptation Strategy has been prepared in close cooperation with the four cities of the metropolitan area (Helsinki, Espoo, Vantaa and Kauniainen), the Helsinki Region Environmental Services Authority HSY and other municipal, regional and state level organisations. In the strategy, strategic starting points and policies with which the metropolitan area prepares for the consequences of climate change, are compiled. The Helsinki Metropolitan Area adaptation strategy concentrates on the adaptation of the built and urban environment to the changing climate. The vision of the strategy is climate proof city - the future is built now. The strategy aims to (1) assess the impacts of climate change in the area, (2) prepare for the impacts of climate change and to extreme weather events and (3) to reduce the vulnerabilities of the area to climate variability and change. The target is to secure the well-being of the citizens and the functioning of the cities also in the changing climate conditions. The preparation of the adaptation strategy started in 2009 by producing the background studies. They include the regional climate and sea level scenarios, modelling of river floods in climate change conditions and a survey of climate change impacts in the region. Also, existing programmes, legislation, research and studies concerning adaptation were collected. The background studies are published in a report titled 'The Helsinki metropolitan area climate is changing - Adaptation strategy background studies' (in Finnish) (HSY 2010). HSY coordinated the strategy preparation. The work was carried out is close cooperation with the experts of the metropolitan area cities, regional emergency services, Ministry of the Environment, Helsinki Region Transport Authority and other regional organisations. The strategy work has had a steering group that consists of representatives of the cities and other central cooperation partners. The

  5. Health and Environment Linked for Information Exchange (HELIX)-Atlanta: A CDC-NASA Joint Environmental Public Health Tracking Collaborative Project

    Science.gov (United States)

    Al-Hamdan, Mohammad; Luvall, Jeff; Crosson, Bill; Estes, Maury; Limaye, Ashutosh; Quattrochi, Dale; Rickman, Doug

    2008-01-01

    HELIX-Atlanta was developed to support current and future state and local EPHT programs to implement data linking demonstration projects which could be part of the CDC EPHT Network. HELIX-Atlanta is a pilot linking project in Atlanta for CDC to learn about the challenges the states will encounter. NASA/MSFC and the CDC are partners in linking environmental and health data to enhance public health surveillance. The use of NASA technology creates value added geospatial products from existing environmental data sources to facilitate public health linkages. Proving the feasibility of the approach is the main objective

  6. UNDERSTANDING THE INTERNATIONAL CONSENSUS FOR ACUTE PANCREATITIS: CLASSIFICATION OF ATLANTA 2012.

    Science.gov (United States)

    Souza, Gleim Dias de; Souza, Luciana Rodrigues Queiroz; Cuenca, Ronaldo Máfia; Jerônimo, Bárbara Stephane de Medeiros; Souza, Guilherme Medeiros de; Vilela, Vinícius Martins

    2016-01-01

    Contrast computed tomography and magnetic resonance imaging are widely used due to its image quality and ability to study pancreatic and peripancreatic morphology. The understanding of the various subtypes of the disease and identification of possible complications requires a familiarity with the terminology, which allows effective communication between the different members of the multidisciplinary team. Demonstrate the terminology and parameters to identify the different classifications and findings of the disease based on the international consensus for acute pancreatitis ( Atlanta Classification 2012). Search and analysis of articles in the "CAPES Portal de Periódicos with headings "acute pancreatitis" and "Atlanta Review". Were selected 23 articles containing radiological descriptions, management or statistical data related to pathology. Additional statistical data were obtained from Datasus and Population Census 2010. The radiological diagnostic criterion adopted was the Radiology American College system. The "acute pancreatitis - 2012 Rating: Review Atlanta classification and definitions for international consensus" tries to eliminate inconsistency and divergence from the determination of uniformity to the radiological findings, especially the terminology related to fluid collections. More broadly as "pancreatic abscess" and "phlegmon" went into disuse and the evolution of the collection of patient fluids can be described as "acute peripancreatic collections", "acute necrotic collections", "pseudocyst" and "necrosis pancreatic walled or isolated". Computed tomography and magnetic resonance represent the best techniques with sequential images available for diagnosis. Standardization of the terminology is critical and should improve the management of patients with multiple professionals care, risk stratification and adequate treatment. A tomografia computadorizada contrastada e a ressonância magnética são exames amplamente utilizados no estudo da

  7. Model LPA Terpadu untuk Wilayah Surabaya Metropolitan

    Directory of Open Access Journals (Sweden)

    Mimien Bt. M. Al Muhdhar a Henie Irawati

    2009-02-01

    Full Text Available The purpose of this research is to establish the integrated LPA model for Surabaya Metropolitan Area. The methods used are literature overviews, comparative studies to well-established areas, and expert assistantships through national seminars. The result shows that the integrated LPA has opportunity to combine some activities such as sorting and classifying, producing, wrapping and containing, selling the compost and decayed materials, and filling residual waste by landfill system. In 25 Ha land area, 14.10 Ha is allocated for waste management, and 10.90 Ha for sanitary landfill.

  8. Multilevel Hierarchical Modeling of Benthic Macroinvertebrate Responses to Urbanization in Nine Metropolitan Regions across the Conterminous United States

    Science.gov (United States)

    Kashuba, Roxolana; Cha, YoonKyung; Alameddine, Ibrahim; Lee, Boknam; Cuffney, Thomas F.

    2010-01-01

    Multilevel hierarchical modeling methodology has been developed for use in ecological data analysis. The effect of urbanization on stream macroinvertebrate communities was measured across a gradient of basins in each of nine metropolitan regions across the conterminous United States. The hierarchical nature of this dataset was harnessed in a multi-tiered model structure, predicting both invertebrate response at the basin scale and differences in invertebrate response at the region scale. Ordination site scores, total taxa richness, Ephemeroptera, Plecoptera, Trichoptera (EPT) taxa richness, and richness-weighted mean tolerance of organisms at a site were used to describe invertebrate responses. Percentage of urban land cover was used as a basin-level predictor variable. Regional mean precipitation, air temperature, and antecedent agriculture were used as region-level predictor variables. Multilevel hierarchical models were fit to both levels of data simultaneously, borrowing statistical strength from the complete dataset to reduce uncertainty in regional coefficient estimates. Additionally, whereas non-hierarchical regressions were only able to show differing relations between invertebrate responses and urban intensity separately for each region, the multilevel hierarchical regressions were able to explain and quantify those differences within a single model. In this way, this modeling approach directly establishes the importance of antecedent agricultural conditions in masking the response of invertebrates to urbanization in metropolitan regions such as Milwaukee-Green Bay, Wisconsin; Denver, Colorado; and Dallas-Fort Worth, Texas. Also, these models show that regions with high precipitation, such as Atlanta, Georgia; Birmingham, Alabama; and Portland, Oregon, start out with better regional background conditions of invertebrates prior to urbanization but experience faster negative rates of change with urbanization. Ultimately, this urbanization

  9. Metropolitan vision making - using backcasting as a strategic learning process to shape metropolitan futures

    NARCIS (Netherlands)

    Neuvonen, A.; Ache, P.M.

    2014-01-01

    Abstract: The need for new forward looking tools in urban planning is immense: The new functional relations and structures are stretching beyond our capacity to 'rationally' capture modern metropolitan spaces Neuman & Hull 2009). At the same time cities struggle to find tools to help manage a

  10. Business profile of metropolitan Las Vegas

    International Nuclear Information System (INIS)

    Boyle, M.R.

    1988-06-01

    This first report describes the present makeup of the Las Vegas metropolitan statistical area (MSA) economy and analyzes the climate for business expansion. The second report contains an assessment of the competitiveness of the area as a location for new or expanded facilities investment by companies in approximately 600 business groups. The third report projects Las Vegas' competitiveness at the start of the next century in the absence of a nuclear waste storage facility and then evaluates the potential impacts of siting that facility near Las Vegas on its ability to attract and retain business investment. The primary purpose of these reports is to contribute to the overall assessment of the environmental impact of the US Department of Energy's proposed action to build and operate an underground nuclear waste storage facility at Yucca Mountain. The first two reports also serve a second purpose -- they can be used by economic development organizations in the Las Vegas metropolitan area in their ongoing efforts to attract new business investment. Information contained in the business climate analysis found in this first report can be incorporated into marketing materials. The competitiveness assessment contained in the second report can be used by these organizations in identifying targets they wish to pursue

  11. Youthification in the Metropolitan Area of Cluj

    Directory of Open Access Journals (Sweden)

    Vlad Cocheci

    2018-06-01

    Full Text Available This research exercise aims to identify all areas affected by what is now known as ‘youthification’ in the Metropolitan Area of Cluj. Broadly speaking, an area touched by youthification witnesses a massive arrival of young adults, who invest in housing, but only remain there until they age. Youthification is usually the second phase within an encompassing process of gentrification. To gain a clearer picture of this phenomenon, we employed a snapshot of the situation recorded by the Population and Housing Census of 2011. Using this image as a starting point, we then applied statistical thresholds aimed at measuring the presence and intensity of youthification within different areas. Thereafter, we looked at areas exhibiting the same level of youthification, in order to find those common traits of their young adult inhabitants that might prove relevant for their choices in matters of housing. Once completed, our efforts resulted in the first map showing the areas affected by youthification within the Metropolitan Area of Cluj. In addition, we reached the following conclusion: Young adults who live in the city are more likely to still be enrolled in a form of education and less likely to be married or to have children than those who live in the suburbs or in rural areas. This observation implies that there might be some hidden dependency relations, which are at work in shaping the choice of housing.

  12. 78 FR 53270 - Revision of Air Quality Implementation Plan; California; Sacramento Metropolitan Air Quality...

    Science.gov (United States)

    2013-08-29

    ... Quality Implementation Plan; California; Sacramento Metropolitan Air Quality Management District... to the Sacramento Metropolitan Air Quality Management District (SMAQMD or District) portion of the..., Sacramento Metropolitan Air Quality Management District, Rule 214 (Federal New Source Review), Rule 203...

  13. 49 CFR 613.100 - Metropolitan transportation planning and programming.

    Science.gov (United States)

    2010-10-01

    ... programming. 613.100 Section 613.100 Transportation Other Regulations Relating to Transportation (Continued... Metropolitan Transportation Planning and Programming § 613.100 Metropolitan transportation planning and programming. The regulations in 23 CFR 450, subpart C, shall be followed in complying with the requirements of...

  14. Urban partnership agreement and congestion reduction demonstration programs : lessons learned on congestion pricing from the Seattle and Atlanta household travel behavior surveys.

    Science.gov (United States)

    2014-04-01

    This paper presents lessons learned from household traveler surveys administered in Seattle and Atlanta as part of the evaluation of the Urban Partnership Agreement and Congestion Reduction Demonstration Programs. The surveys use a two-stage panel su...

  15. Preventing the repetition: Or, what Los Angeles' experience in water management can teach Atlanta about urban water disputes

    Science.gov (United States)

    Feldman, David L.

    2009-04-01

    Southern California's water history is an epic story with larger-than-life characters and ambitions and abundant hubris. Students of water policy might reasonably ask: Does this story, while unique to greater Los Angeles, hold lessons for other metropolises experiencing water conflict caused by explosive growth? We examine this question by considering similarities between the challenges facing Atlanta, Georgia, one of the nation's fastest growing cities in the 21st century, with those of Los Angeles. We focus on junctures where important decisions regarding water were made and how these decisions continue to challenge both cities' futures. Atlanta's financial, cultural, and environmental imprint on its surrounding region share remarkable similarities with Los Angeles' influence trajectory: it is the largest city in the southeast, a principal transportation and business hub, and it is embroiled in water conflict with nearby communities and adjoining states.

  16. Influence of Intimate Partner Violence on Domestic Relocation in Metropolitan and Non-Metropolitan Young Australian Women

    NARCIS (Netherlands)

    Dillon, Gina; Hussain, Rafat; Kibele, Eva; Rahman, Saifur; Loxton, Deborah

    2016-01-01

    Data from a national, population-based longitudinal study of Australian women (26-34 years) were analyzed to investigate the association between domestic relocation and multiple explanatory factors, namely intimate partner violence (IPV), metropolitan versus non-metropolitan residence, education,

  17. Filling some black holes: modeling the connection between urbanization, infrastructure, and global service intensity in 112 metropolitan regions across the world

    OpenAIRE

    Van De Vijver, Elien; Derudder, Ben; Bassens, David; Witlox, Frank

    2012-01-01

    This empirical article combines insights from previous research on the level of knowledge-intensive service in metropolitan areas with the aim to develop an understanding of the spatial structure of the global service economy. We use a stepwise regression model with GaWC’s measure of globalized service provisioning as the dependent variable and a range of variables focusing on population, infrastructure, urban primacy, and national regulation as independent variables. The discussion of the re...

  18. Ga penetration into polymers

    Czech Academy of Sciences Publication Activity Database

    Hnatowicz, Vladimír; Švorčík, V.; Efimenko, K.; Rybka, V.

    1999-01-01

    Roč. 68, - (1999), s. 357-358 ISSN 0947-8396 R&D Projects: GA ČR GA202/96/0077; GA AV ČR KSK1048601 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.753, year: 1999

  19. Effects of urbanization on streamflow in the Atlanta area (Georgia, USA): A comparative hydrological approach

    Science.gov (United States)

    Rose, S.; Peters, N.E.

    2001-01-01

    For the period from 1958 to 1996, streamflow characteristics of a highly urbanized watershed were compared with less-urbanized and non-urbanized watersheds within a 20 000 km2 region in the vicinity of Atlanta, Georgia: In the Piedmont and Blue Ridge physiographic provinces of the southeastern USA. Water levels in several wells completed in surficial and crystalline-rock aquifers were also evaluated. Data were analysed for seven US Geological Survey (USGS) stream gauges, 17 National Weather Service rain gauges, and five USGS monitoring wells. Annual runoff coefficients (RCs; runoff as a fractional percentage of precipitation) for the urban stream (Peachtree Creek) were not significantly greater than for the less-urbanized watersheds. The RCs for some streams were similar to others and the similar streams were grouped according to location. The RCs decreased from the higher elevation and higher relief watersheds to the lower elevation and lower relief watersheds: Values were 0.54 for the two Blue Ridge streams. 0.37 for the four middle Piedmont streams (near Atlanta), and 0.28 for a southern Piedmont stream. For the 25 largest stormflows, the peak flows for Peachtree Creek were 30% to 100% greater then peak flows for the other stream. The storm recession period for the urban stream was 1-2 days less than that for the other streams and the recession was characterized by a 2-day storm recession constant that was, on average, 40 to 100% greater, i.e. streamflow decreased more rapidly than for the other streams. Baseflow recession constants ranged from 35 to 40% lower for Peachtree Creek than for the other streams; this is attributed to lower evapotranspiration losses, which result in a smaller change in groundwater storage than in the less-urbanized watersheds. Low flow of Peachtree Creek ranged from 25 to 35% less than the other streams, possibly the result of decreased infiltration caused by the more efficient routing of stormwater and the paving of groundwater

  20. Radon survey in Metropolitan Toronto schools

    International Nuclear Information System (INIS)

    Becker, E.; Moridi, R.

    1992-01-01

    The radon testing survey in Metropolitan Toronto public schools was the most intensive project of its kind ever undertaken in Canadian schools. It also included an extensive public education program on radiation and radon-in-schools. The radon levels at 632 schools were measured using the CAIRS Radon Monitors. Ninety percent of the locations measured were found to have a radon level equal to or less than 2 mWL. Two locations in two different schools were found to have a radon level at or above the Action Level (20 mWL). The remaining results were between the two extremes. Follow-up testing in those schools where more than 10 mWL of radon was found is in progress. (author)

  1. Suburbanization and sustainability in metropolitan Moscow.

    Science.gov (United States)

    Mason, Robert J; Nigmatullina, Liliya

    2011-01-01

    Although Soviet-era urban-growth controls produced relatively sustainable metropolitan development patterns, low-density suburban sprawl has accelerated markedly in modern Russia. Distinctive features of Moscow's development history are its greenbelt, which dates from 1935 and is becoming increasingly fragmented, proliferation of satellite cities at the urban fringe, conversion of seasonal dachas into full-time residences, the very exclusive Rublevo Uspenskoe Highway development, and today's crippling traffic congestion. The recent economic crisis has slowed development and actually increased the supply of “economy-class” single-family homes, for which there is much pent-up desire but insufficient credit availability to meet the demand. A renewed commitment to sustainability's triple bottom line—environmental quality, equity, and economic prosperity—will require greater government transparency and fairness, stronger planning controls, and an expanded public transportation system.

  2. Susceptibility to Heat-Related Fluid and Electrolyte Imbalance Emergency Department Visits in Atlanta, Georgia, USA

    Directory of Open Access Journals (Sweden)

    Leila Heidari

    2016-10-01

    Full Text Available Identification of populations susceptible to heat effects is critical for targeted prevention and more accurate risk assessment. Fluid and electrolyte imbalance (FEI may provide an objective indicator of heat morbidity. Data on daily ambient temperature and FEI emergency department (ED visits were collected in Atlanta, Georgia, USA during 1993–2012. Associations of warm-season same-day temperatures and FEI ED visits were estimated using Poisson generalized linear models. Analyses explored associations between FEI ED visits and various temperature metrics (maximum, minimum, average, and diurnal change in ambient temperature, apparent temperature, and heat index modeled using linear, quadratic, and cubic terms to allow for non-linear associations. Effect modification by potential determinants of heat susceptibility (sex; race; comorbid congestive heart failure, kidney disease, and diabetes; and neighborhood poverty and education levels was assessed via stratification. Higher warm-season ambient temperature was significantly associated with FEI ED visits, regardless of temperature metric used. Stratified analyses suggested heat-related risks for all populations, but particularly for males. This work highlights the utility of FEI as an indicator of heat morbidity, the health threat posed by warm-season temperatures, and the importance of considering susceptible populations in heat-health research.

  3. Dietary intake and overweight and obesity among persons living with HIV in Atlanta Georgia.

    Science.gov (United States)

    Hernandez, Dominica; Kalichman, Seth; Cherry, Chauncey; Kalichman, Moira; Washington, Christopher; Grebler, Tamar

    2017-06-01

    In the U.S., there has been a rise in overweight and obesity among persons living with HIV (PLWH). The aim of this study was to examine dietary intake and body mass index (BMI) in PLWH in Atlanta Georgia relative to the U.S. Dietary intake among PLWH was compared with recommended standards as well as estimated dietary intake for adults in the U.S. Over 31% of the study participants were overweight [BMI = 25-29.9 kg/m 2 ], and 33.1% obese [BMI ≥ 30 kg/m 2 ]. Results indicated significant dietary differences between participants in our sample and U.S. daily recommendations for adults as well as estimated intakes of the U.S. Both males and females consumed more percentage of energy from fat and less fiber as well as fruit and vegetables servings than what is recommended. Results suggest that overweight and obesity are an additional health burden to PLWH in our sample and that their daily dietary practices are not meeting the U.S. government-recommended nutritional standards.

  4. Metropolitan migration and population growth in selected developing countries.

    Science.gov (United States)

    1983-01-01

    The purpose of this article is to estimate the components of metropolitan population growth in selected developing countries during 1960-1970 period. The study examines population growth in 26 cities: 5 are in Africa, 8 in Asia, and 13 in Latin America, using data from national census publications. These cities in general are the political capitals of their countries, but some additional large cities were selected in Brazil, Mexico, and South Africa. All cities, at the beginning of the 1960-1970 decade had over 500,000 population; Accra, the only exception, reached this population level during the 1960s. Some cities had over 4 million residents in 1970. Net migration contributed about 37% to total metropolitan population growth; the remainder of the growth is attributable to natural increase. Migration has a much stronger impact on metropolitan growth than suggested by the above figure: 1) Several metropolitan areas, for various reasons, are unlikely to receive many migrants; without those cities, the share of metropolitan growth from net migration is 44%. 2) Estimates of the natural increase of migrants after their arrival in the metropolitan areas, when added to migration itself, changes the total contribution of migration to 49% in some metropolitan areas. 3) Even where net migration contributes a smaller proportion to metropolitan growth than natural increase, the rates of net migration are generally high and should be viewed in the context of rapid metropolitan population growth from natural increase alone. Finally, the paper also compares the components of metropolitan growth with the components of growth in the remaining urban areas. The results show that the metropolitan areas, in general, grow faster than the remaining urban areas, and that this more rapid growth is mostly due to a higher rate of net migration. Given the significance of migration for metropolitan growth, further investigations of the effects of these migration streams, particularly with

  5. ‘New urbanism' or metropolitan-level centralization?

    DEFF Research Database (Denmark)

    Næss, Petter

    2011-01-01

    Based on a study in Copenhagen Metropolitan Area, this paper compares the influences of macro-level and micro-level urban form characteristics on the respondents' traveling distance by car on weekdays. The Copenhagen study shows that metropolitan-scale urban structural variables generally exert...... stronger influences than neighborhood-scale built environment characteristics on the amount of car travel. In particular, the location of the residence relative to the main city center of the metropolitan region shows a strong effect. Some local scale variables often mentioned in the literature...

  6. Improved InGaN/GaN quantum wells on treated GaN template with a Ga-rich GaN interlayer

    International Nuclear Information System (INIS)

    Fang, Zhilai; Shen, Xiyang; Wu, Zhengyuan; Zhang, Tong-Yi

    2015-01-01

    Treated GaN template was achieved by in situ droplet epitaxy of a Ga-rich GaN interlayer on the conventional GaN template. InGaN/GaN quantum wells (QWs) were grown on the conventional and treated GaN templates under the same growth conditions and then comprehensively characterized. The indium homogeneity in the InGaN layers and the interface sharpness between InGaN and GaN layers of the InGaN/GaN QWs on the treated GaN template were significantly improved. The emission intensity from the InGaN/GaN QWs on the treated GaN template was enhanced by 20% than that on the conventional GaN template, which was attributed to the strain reduction and the improvement in crystalline quality. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Intestinal Parasites among Waste-Handlers in Jos Metropolitan Area ...

    African Journals Online (AJOL)

    Intestinal Parasites among Waste-Handlers in Jos Metropolitan Area of Plateau State, Nigeria. ... Solid waste management is associated with health hazards. ... Waste disposal workers are at high risk of infection with different species of ...

  8. Statewide and Metropolitan Transportation Planning Processes : a TPCB Peer Exchange

    Science.gov (United States)

    2016-04-20

    This report highlights key recommendations and noteworthy practices identified at Statewide and Metropolitan Transportation Planning Processes Peer Exchange held on September 9-10, 2015 in Shepherdstown, West Virginia. This event was sponsored ...

  9. Towards a Metropolitan Fundamental Diagram Using Travel Survey Data

    Science.gov (United States)

    2016-01-01

    Using travel diary data from 2000–2001 and 2010–2012 this research examines fundamental traffic relationships at the metropolitan level. The results of this paper can help to explain the causes of some traffic phenomena. Network average speed by time of day can be explained by trip length and cumulative number of vehicles on the road. A clockwise hysteresis loop is found in the Metropolitan Fundamental Diagram in the morning period and a reverse process happens in the afternoon. PMID:26866913

  10. Understanding metropolitan patterns of daily encounters.

    Science.gov (United States)

    Sun, Lijun; Axhausen, Kay W; Lee, Der-Horng; Huang, Xianfeng

    2013-08-20

    Understanding of the mechanisms driving our daily face-to-face encounters is still limited; the field lacks large-scale datasets describing both individual behaviors and their collective interactions. However, here, with the help of travel smart card data, we uncover such encounter mechanisms and structures by constructing a time-resolved in-vehicle social encounter network on public buses in a city (about 5 million residents). Using a population scale dataset, we find physical encounters display reproducible temporal patterns, indicating that repeated encounters are regular and identical. On an individual scale, we find that collective regularities dominate distinct encounters' bounded nature. An individual's encounter capability is rooted in his/her daily behavioral regularity, explaining the emergence of "familiar strangers" in daily life. Strikingly, we find individuals with repeated encounters are not grouped into small communities, but become strongly connected over time, resulting in a large, but imperceptible, small-world contact network or "structure of co-presence" across the whole metropolitan area. Revealing the encounter pattern and identifying this large-scale contact network are crucial to understanding the dynamics in patterns of social acquaintances, collective human behaviors, and--particularly--disclosing the impact of human behavior on various diffusion/spreading processes.

  11. Planning Assignments of the Italian Metropolitan Cities. Early Trends

    Directory of Open Access Journals (Sweden)

    Giuseppe Mazzeo

    2017-04-01

    Full Text Available The last stage of the process of establishment of the Italian Metropolitan Cities, which took place in 2014, follows of a few decades the start of this institutional reform. In 1990, in fact, the Act 142 (Local Autonomies Reform had planned metropolitan areas as the administrative organization more suitable to provide these territories of structures for the management and the strategic development alike the best international models. The paper proposes to analyse the first activities taken by the Italian Metropolitan Cities in the sector of territorial government, three years after the enactment in 2014 of Act nr. 56.  Focal point of the analysis is the jurisdiction in the formation of two plans (the Strategic Plan and the Metropolitan Territorial Plan and the following relationships among them, in the logical assumption that between them a necessary and strict consistency there should be. In the first part, the paper analyses some factors characterizing the metropolitan areas and the functions that the law assigns to the new institution in the territorial government sector. The second part outlines the updated situation with regard to the formation of the sectoral tools (Strategic Plan, Territorial Plan and homogeneous zones. The third part analyses the progresses in three Metropolitan Cities taken as sample (Milan, Genoa and Bologna and, in general, to those of Southern Italy. In the last part, the paper exposes some considerations regarding the issues raised in the article, particularly about the innovativeness of the tools and the timeline for the implementation of the act.

  12. Initiatives towards Carbon Neutrality in the Helsinki Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Karna Dahal

    2016-07-01

    Full Text Available Carbon neutrality represents one climate strategy adopted by many cities, including the city of Helsinki and the Helsinki metropolitan area in Finland. This study examines initiatives adopted by the Helsinki metropolitan area aimed at reducing energy-related carbon emissions and achieving carbon neutrality through future actions. Various sectorial energy consumption rates per year and carbon emissions from various sectors within the city of Helsinki and the metropolitan area were extracted from an online database and re-calculated (in GWh, MWh/inhabitant and MtCO2e, KtCO2e/inhabitant. We employed a backcasting scenario method to explore the various carbon reduction measures in the Helsinki metropolitan area. About 96% of the emissions produced in the Helsinki metropolitan area are energy-based. District heating represents the primary source of emissions, followed by transportation and electricity consumption, respectively. We also found that accomplishing the carbon reduction strategies of the Helsinki metropolitan area by 2050 remains challenging. Technological advancement for clean and renewable energy sources, smart policies and raising awareness resulting in behavioral changes greatly affect carbon reduction actions. Thus, strong political commitments are also required to formulate and implement stringent climate actions.

  13. New Atlanta Classification of acute pancreatitis in intensive care unit: Complications and prognosis.

    Science.gov (United States)

    Pintado, María-Consuelo; Trascasa, María; Arenillas, Cristina; de Zárate, Yaiza Ortiz; Pardo, Ana; Blandino Ortiz, Aaron; de Pablo, Raúl

    2016-05-01

    The updated Atlanta Classification of acute pancreatitis (AP) in adults defined three levels of severity according to the presence of local and/or systemic complications and presence and length of organ failure. No study focused on complications and mortality of patients with moderately severe AP admitted to intensive care unit (ICU). The main aim of this study is to describe the complications developed and outcomes of these patients and compare them to those with severe AP. Prospective, observational study. We included patients with acute moderately severe or severe AP admitted in a medical-surgical ICU during 5years. We collected demographic data, admission criteria, pancreatitis etiology, severity of illness, presence of organ failure, local and systemic complications, ICU length of stay, and mortality. Fifty-six patients were included: 12 with moderately severe AP and 44 with severe. All patients developed some kind of complications without differences on complications rate between moderately severe or severe AP. All the patients present non-infectious systemic complications, mainly acute respiratory failure and hemodynamic failure. 82.1% had an infectious complication, mainly non-pancreatic infection (66.7% on moderately severe AP vs. 79.5% on severe, p=0.0443). None of the patients with moderately severe AP died during their intensive care unit stay vs. 29.5% with severe AP (p=0.049). Moderately severe AP has a high rate of complications with similar rates to patients with severe AP admitted to ICU. However, their ICU mortality remains very low, which supports the existence of this new group of pancreatitis according to their severity. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  14. From Olympia to Atlanta: a cultural-historical perspective on diet and athletic training.

    Science.gov (United States)

    Grivetti, L E; Applegate, E A

    1997-05-01

    Greek and Roman writers described diet and training of Olympic athletes. Lucian (A.D. 120-ca. 180) described distance and speed work in runners; Galen (A.D. 131-201) recommended ball-related exercises to train vision and the body; Philostratos (A.D. 170-249) suggested cross training by endurance running, weight training, and wrestling with animals. The ancient Greek training system, the tetrad (eta tau epsilon tau rho alpha sigma), was a four-day cycle with each day devoted to a different activity. Diogenes Laertius (died A.D. 222) wrote that Greek athletes trained on dried figs, moist cheese and wheat; then the pattern changed and focused on meat. Epictetus (2nd century A.D.) wrote that Olympic victors avoided desserts and cold water and took wine sparingly. Philostratos deprecated athletic diet in his era, a pattern based on white bread sprinkled with poppy seeds, fish and pork. Americans at the XIth Olympiad in Berlin (1936) consumed beefsteak with average daily intake of 125 grams of butter or cotton oil, three eggs, custard for dessert and 1.5 L of milk. The American pattern at Berlin was characterized by ad libitum intake of white bread, dinner rolls, fresh vegetables and salads. At Atlanta, more than 5 million meals will be served during the Olympic festival. The highly varied menu will include fresh vegetables and dips; fruits, cheeses and breads; salads; pasta, rice and fruit salads; soups; meat and seafood entrees; hot vegetables; desserts; and beverages. American Southern specialties will be served.

  15. Use of chemical analysis and assays of semipermeable membrane devices extracts to assess the response of bioavailable organic pollutants in streams to urbanization in six metropolitan areas of the United States

    Science.gov (United States)

    Bryant, Wade L.; Goodbred, Steve L.; Leiker, Thomas L.; Inouye, Laura; Johnson, B. Thomas

    2007-01-01

    Studies to assess the effects of urbanization on stream ecosystems are being conducted as part of the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program. The overall objectives of these studies are to (1) determine how hydrologic, geomorphic, water quality, habitat, and biological characteristics respond to land-use changes associated with urbanization in specific environmental settings, and (2) compare these responses across environmental settings. As part of an integrated assessment, semipermeable membrane devices (SPMDs) were deployed in streams along a gradient of urban land-use intensity in and around Atlanta, Georgia; Raleigh-Durham, North Carolina; and Denver-Fort Collins, Colorado, in 2003; and Dallas-Fort Worth, Texas; Milwaukee-Green Bay, Wisconsin; and Portland, Oregon, in 2004. Sites were selected to avoid point-source discharge and to minimize natural variability within each of the six metropolitan areas. In addition to standard chemical analysis for hydrophobic organic contaminants, three assays were used to address mixtures and potential toxicity: (1) Fluoroscan provides an estimate of the total concentration of polycyclic aromatic hydrocarbons (PAHs); (2) the P450RGS assay indicates the presence and levels of aryl hydrocarbon receptor agonists; and (3) Microtox® measures toxicological effects on photo-luminescent bacteria.Of the 140 compounds targeted or identified by gas chromatography/mass spectrometry analysis in this study, 67 were not detected. In terms of numbers and types of compounds, the following were detected: 2 wood preservatives, 6 insecticides (parent compounds), 5 herbicides, 22 polycyclic aromatic hydrocarbons, 2 dibenzofurans, 4 polychlorinated biphenyls, 7 compounds associated with fragrances or personal care products, 4 steroids associated with wastewater, 5 polydibromated diphenyl ethers (flame retardants), 3 plasticizers, 3 antimicrobials/disinfectants, and 3 detergent metabolites.Of the 73

  16. Social, economic, and political processes that create built environment inequities: perspectives from urban African Americans in Atlanta.

    Science.gov (United States)

    Redwood, Yanique; Schulz, Amy J; Israel, Barbara A; Yoshihama, Mieko; Wang, Caroline C; Kreuter, Marshall

    2010-01-01

    Growing evidence suggests that the built environment features found in many high-poverty urban areas contribute to negative health outcomes. Both built environment hazards and negative health outcomes disproportionately affect poor people of color. We used community-based participatory research and Photovoice in inner-city Atlanta to elicit African Americans' perspectives on their health priorities. The built environment emerged as a critical factor, impacting physical and mental health outcomes. We offer a conceptual model, informed by residents' perspectives, linking social, economic, and political processes to built environment and health inequities. Research, practice, and policy implications are discussed within an environmental justice framework.

  17. Internal audit risk management in metropolitan municipalities

    Directory of Open Access Journals (Sweden)

    Christo Ackermann

    2016-07-01

    Full Text Available Internal audit functions (IAFs of organisations are regarded as crucial components of the combined assurance model, alongside the audit committee, management and external auditors. The combined assurance model aims at having integrated and aligned assurance in organisations with the overall aim of maximising risk and governance oversight and control efficiencies. In this regard, internal audit plays a crucial role, insofar as it consists of experts in risk, governance and control consultancy who provide assurance to senior management and the audit committee. Audit committees are dependent on internal audit for information and their effectiveness revolves around a strong and well-resourced internal audit function which is able to aid audit committees to meet their oversight responsibilities. There is thus a growing demand for managing risk through the process of risk management and internal audit is in a perfect position to assist with the improvement of such processes. If internal auditors wish to continue being an important aspect of the combined assurance model, they need to address the critical area, amongst others, of risk management as part of their work. If not, it follows that the board, audit committees and other levels of management will remain uninformed on the status of these matters which, in turn, will negatively impact the ability of these stakeholders to discharge their responsibilities. This study therefore focuses on analysing the functioning of IAFs, with specific reference to their risk management mandate. The study followed a mixed method approach to describe internal audits risk management functioning in the big eight metropolitan municipalities in South Africa. The results show that internal audit provide a broad scope of risk management work which assist senior management in the discharge of their responsibilities. However, in the public eye, internal audits risk management functioning is scant

  18. Radon in soil gas in the metropolitan region of Belo Horizonte, Brazil

    International Nuclear Information System (INIS)

    Teixeira, Giane Gariglio; Rocha, Zildete

    2007-01-01

    Radon, the natural radioactive gas is produced by the radioactive decay of uranium and thorium which are ubiquitous, specially in rock and soil. By diffusion and convection. Radon migrate from the rocks and to the groundwater and to the soil and from them the radon migrate through fissures, pipes and hales to the surface. Measurements were carried out in the Metropolitan Region of Belo Horizonte, whose greatest part of the in habitants occupies the great pre cambrian unit of the Iron Quadrangle of Minas Gerais denominated 'Granitic Gneissic Complex', composed of Archean rocks of age between 3,2 Ga and 2,6 Ga. The part in which occurs in the municipal area of Belo Horizonte was denominated as Complexo Belo Horizonte, whose most characteristics rocks named Gneiss Belo Horizonte. The soil gas radon concentrations were determined by using a samples and a continuos flow through ionization chamber detector AlphaGUARD PQ2000PRO - Genitron Instruments GmbH in a Instrumental Neutron Activation Analysis). Most results of radon concentration soil gas were in the range 10 kBq/m 3 to 50 kBq/m 3 . This values, according to the established Swedish Criteria are normal risk values. For soils classified as normal risk require 'radon protective construction', but the necessity of mitigation actions will depend on other factors, for example the soil permeability and rock type. (author)

  19. Shoal bass hybridization in the Chattahoochee River Basin near Atlanta, Georgia

    Science.gov (United States)

    Taylor, Andrew T.; Tringali, Michael D.; O'Rourke, Patrick M.; Long, James M.

    2018-01-01

    The shoal bass (Micropterus cataractae) is a sportfish endemic to the Apalachicola-Chattahoochee-Flint Basin of the southeastern United States. Introgression with several non-native congeners poses a pertinent threat to shoal bass conservation, particularly in the altered habitats of the Chattahoochee River. Our primary objective was to characterize hybridization in shoal bass populations near Atlanta, Georgia, including a population inhabiting Big Creek and another in the main stem Chattahoochee River below Morgan Falls Dam (MFD). A secondary objective was to examine the accuracy of phenotypic identifications below MFD based on a simplified suite of characters examined in the field. Fish were genotyped with 16 microsatellite DNA markers, and results demonstrated that at least four black bass species were involved in introgressive hybridization. Of 62 fish genotyped from Big Creek, 27% were pure shoal bass and 65% represented either F1 hybrids of shoal bass x smallmouth bass (M. dolomieu) or unidirectional backcrosses towards shoal bass. Of 29 fish genotyped below MFD and downstream at Cochran Shoals, 45% were pure shoal bass. Six hybrid shoal bass included both F1 hybrids and backcrosses with non-natives including Alabama bass (M. henshalli), spotted bass (M. punctulatus), and smallmouth bass. Shoal bass alleles comprised only 21% of the overall genomic composition in Big Creek and 31% below MFD (when combined with Cochran Shoals). Phenotypic identification below MFD resulted in an overall correct classification rate of 86% when discerning pure shoal bass from all other non-natives and hybrids. Results suggest that although these two shoal bass populations feature some of the highest introgression rates documented, only a fleeting opportunity may exist to conserve pure shoal bass in both populations. Continued supplemental stocking of pure shoal bass below MFD appears warranted to thwart increased admixture among multiple black bass taxa, and a similar stocking

  20. Relation of urbanization to stream habitat and geomorphic characteristics in nine metropolitan areas of the United States

    Science.gov (United States)

    Fitzpatrick, Faith A.; Peppler, Marie C.

    2010-01-01

    The relation of urbanization to stream habitat and geomorphic characteristics was examined collectively and individually for nine metropolitan areas of the United States?Portland, Oregon; Salt Lake City, Utah; Denver, Colorado; Dallas?Forth Worth, Texas; Milwaukee?Green Bay, Wisconsin; Birmingham, Alabama; Atlanta, Georgia; Raleigh, North Carolina; and Boston, Massachusetts. The study was part of a larger study conducted by the U.S. Geological Survey from 1999 to 2004 to examine the effects of urbanization on the physical, chemical, and biological components of stream ecosystems. The objectives of the current study were to determine how stream habitat and geomorphic characteristics relate to different aspects of urbanization across a variety of diverse environmental settings and spatial scales. A space-for-time rural-to-urban land-cover gradient approach was used. Reach-scale habitat data and geomorphic characteristic data were collected once during low flow and included indicators of potential habitat degradation such as measures of channel geometry and hydraulics, streambed substrate, low-flow reach volume (an estimate of base-flow conditions), habitat complexity, and riparian/bank conditions. Hydrologic metrics included in the analyses were those expected to be altered by increases in impervious surfaces, such as high-flow frequency and duration, flashiness, and low-flow duration. Other natural and human features, such as reach-scale channel engineering, geologic setting, and slope, were quantified to identify their possible confounding influences on habitat relations with watershed-scale urbanization indicators. Habitat and geomorphic characteristics were compared to several watershed-scale indicators of urbanization, natural landscape characteristics, and hydrologic metrics by use of correlation analyses and stepwise linear regression. Habitat and geomorphic characteristics were related to percentages of impervious surfaces only in some metropolitan areas and

  1. They "miss more than anything their normal life back home": masculinity and extramarital sex among Mexican migrants in Atlanta.

    Science.gov (United States)

    Hirsch, Jennifer S; Muñoz-Laboy, Miguel; Nyhus, Christina M; Yount, Kathryn M; Bauermeister, José A

    2009-03-01

    Gender has been recognized as a significant influence on sexual health behaviors. Labor migration presents an important context of vulnerability for sexual health. To understand how the context of migration affects risk-related practices, both cultural and social aspects of gender need to be explored. In the quantitative part of a mixed-methods study conducted in 1999 in Atlanta, 187 Mexican migrant men were asked about their demographic characteristics; sexual history; migration motivations; substance use; social support; leisure-time activities; and ideas about masculinity, sexuality and marriage. Multivariate regression analyses were conducted to test the association between these domains and men's number of partners since their arrival in Atlanta. Number of partners was positively associated with owning a home in Mexico; number of trips back to Mexico; social network size; having had a sex worker as a partner; and going out dancing and to strip clubs on weekends (coefficients, 0.3-4.1). It was negatively associated with age, education, contact with social network members and feeling that sex is tied to emotional intimacy (-0.4 to -1.0). Programs must acknowledge and target migrant men's social networks and the spaces in which they may encounter risky sexual situations. Multilevel strategies, such as the development of more health-enhancing community spaces and the promotion of safer sexual practices should form part of comprehensive efforts to reduce sexual risk among migrant men.

  2. Social vulnerability to heat in Greater Atlanta, USA: spatial pattern of heat, NDVI, socioeconomics and household composition

    Science.gov (United States)

    Sim, Sunhui

    2017-10-01

    The purpose of the article is evaluating spatial patterns of social vulnerability to heat in Greater Atlanta in 2015. The social vulnerability to heat is an index of socioeconomic status, household composition, land surface temperature and normalized differential vegetation index (NDVI). Land surface temperature and NDVI were derived from the red, NIR and thermal infrared (TIR) of a Landsat OLI/TIRS images collected on September 14, 2015. The research focus is on the variation of heat vulnerability in Greater Atlanta. The study found that heat vulnerability is highly clustered spatially, resulting in "hot spots" and "cool spots". The results show significant health disparities. The hotspots of social vulnerability to heat occurred in neighborhoods with lower socioeconomic status as measured by low education, low income and more poverty, greater proportion of elderly people and young children. The findings of this study are important for identifying clusters of heat vulnerability and the relationships with social factors. These significant results provide a basis for heat intervention services.

  3. The food environment and adult obesity in US metropolitan areas.

    Science.gov (United States)

    Michimi, Akihiko; Wimberly, Michael C

    2015-11-26

    This research examines the larger-scale associations between obesity and food environments in metropolitan areas in the United States (US). The US Census County Business Patterns dataset for 2011 was used to construct various indices of food environments for selected metropolitan areas. The numbers of employees engaged in supermarkets, convenience stores, full service restaurants, fast food restaurants, and snack/coffee shops were standardised using the location quotients, and factor analysis was used to produce two uncorrelated factors measuring food environments. Data on obesity were obtained from the 2011 Behavioral Risk Factor Surveillance System. Individual level obesity measures were linked to the metropolitan area level food environment factors. Models were fitted using generalised estimating equations to control for metropolitan area level intra-correlation and individual level sociodemographic characteristics. It was found that adults residing in cities with a large share of supermarket and full-service restaurant workers were less likely to be obese, while adults residing in cities with a large share of convenience store and fast food restaurant workers were more likely to be obese. Supermarkets and full-service restaurant workers are concentrated in the Northeast and West of the US, where obesity prevalence is relatively lower, while convenience stores and fast-food restaurant workers are concentrated in the South and Midwest, where obesity prevalence is relatively higher. The food environment landscapes measured at the metropolitan area level explain the continental-scale patterns of obesity prevalence. The types of food that are readily available and widely served may translate into obesity disparities across metropolitan areas.

  4. 67Ga lung scan

    International Nuclear Information System (INIS)

    Niden, A.H.; Mishkin, F.S.; Khurana, M.M.L.; Pick, R.

    1977-01-01

    Twenty-three patients with clinical signs of pulmonary embolic disease and lung infiltrates were studied to determine the value of gallium citrate 67 Ga lung scan in differentiating embolic from inflammatory lung disease. In 11 patients without angiographically proved embolism, only seven had corresponding ventilation-perfusion defects compatible with inflammatory disease. In seven of these 11 patients, the 67 Ga concentration indicated inflammatory disease. In the 12 patients with angiographically proved embolic disease, six had corresponding ventilation-perfusion defects compatible with inflammatory disease. None had an accumulation of 67 Ga in the area of pulmonary infiltrate. Thus, ventilation-perfusion lung scans are of limited value when lung infiltrates are present. In contrast, the accumulation of 67 Ga in the lung indicates an inflammatory process. Gallium imaging can help select those patients with lung infiltrates who need angiography

  5. Printing activity of the Metropolitan Gavriil Banulescu Bodoni

    Directory of Open Access Journals (Sweden)

    Nicolae Fustei

    2013-07-01

    Full Text Available The present study is dedicated to the printing activity of the Metropolitan Gavriil Bănulescu-Bodoni’s activity. The religious and secular prints made from Chisinau’s Diocesan typography by Metropolitan Gavriil promote the idea of national unity of people from Moldavia, Wallachia and Transylvania. Due to the new documents from archives, more evidences and „more light” are being spread over the activity of famous hierarch, whose life is linked with the history of culture of three nations – Romanians, Ukrainians and Russians.

  6. Tracking the deployment of the integrated metropolitan ITS infrastructure in Orlando : FY99 results

    Science.gov (United States)

    2000-01-01

    In January 1996, Secretary Pea set a goal of deploying the integrated metropolitan Intelligent Transportation System (ITS) infrastructure in 75 of the nations largest metropolitan areas by 2006. In 1997, the U.S. Department of Transportation ini...

  7. 75 FR 40726 - Revisions to the California State Implementation Plan, Sacramento Metropolitan Air Quality...

    Science.gov (United States)

    2010-07-14

    ... the California State Implementation Plan, Sacramento Metropolitan Air Quality Management District and South Coast Air Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION... Metropolitan Air Quality Management District (SMAQMD) and South Coast Air Quality Management District (SCAQMD...

  8. 75 FR 40762 - Revisions to the California State Implementation Plan, Sacramento Metropolitan Air Quality...

    Science.gov (United States)

    2010-07-14

    ... the California State Implementation Plan, Sacramento Metropolitan Air Quality Management District and South Coast Air Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the Sacramento Metropolitan Air Quality...

  9. A Study of the Role of Clouds in the Relationship Between Land Use/Land Cover and the Climate and Air Quality of the Atlanta Area

    Science.gov (United States)

    Kidder, Stanley Q.; Hafner, Jan

    2001-01-01

    The goal of Project ATLANTA is to derive a better scientific understanding of how land cover changes associated with urbanization affect climate and air quality. In this project the role that clouds play in this relationship was studied. Through GOES satellite observations and RAMS modeling of the Atlanta area, we found that in Atlanta (1) clouds are more frequent than in the surrounding rural areas; (2) clouds cool the surface by shading and thus tend to counteract the warming effect of urbanization; (3) clouds reflect sunlight, which might other wise be used to produce ozone; and (4) clouds decrease biogenic emission of ozone precursors, and they probably decrease ozone concentration. We also found that mesoscale modeling of clouds, especially of small, summertime clouds, needs to be improved and that coupled mesoscale and air quality models are needed to completely understand the mediating role that clouds play in the relationship between land use/land cover change and the climate and air quality of Atlanta. It is strongly recommended that more cities be studied to strengthen and extend these results.

  10. Task Force on Women, Minorities and the Handicapped in Science and Technology: Executive Session. Report of the Proceedings (Atlanta, Georgia, March 3, 1988).

    Science.gov (United States)

    Task Force on Women, Minorities, and the Handicapped in Science and Technology, Washington, DC.

    The Task Force on Women, Minorities, and the Handicapped in Science and Technology was established by the U.S. Congress in Public Law 99-383 with the purpose of developing a long-range plan for broadening participation in science and engineering. Public hearings were held in Albuquerque (New Mexico), Atlanta (Georgia), Baltimore (Maryland), Boston…

  11. New Metropolitan Spaces and Metropolitan Strategies in the Face of Modernisation

    Directory of Open Access Journals (Sweden)

    Willem Salet

    2007-10-01

    Full Text Available Au début du xxie siècle, les espaces urbains traversent une période de croissance et de transformation radicale. Les villes s’étendent de plus en plus. Leur configuration spatiale devient de plus en plus décentralisée et fragmentée. La dichotomie traditionnelle entre hiérarchie urbaine et périphérie est en train de disparaître. Les nouveaux espaces métropolitains sont caractérisés par des processus de segmentation et de spécialisation à distance ainsi que par des polarisations sociales qui structurent l’espace. Les tentatives de planification des villes-régions essaient de rééquilibrer ces processus qui font éclater la ville. Cet article explore brièvement les transformations métropolitaines actuelles en utilisant une approche générique. Il se focalise également sur les stratégies des métropoles pour affronter ces défis dans le cadre de situations institutionnelles variées, un peu partout en Europe. En troisième lieu, cet article interroge les effets potentiels des projets urbains sur un rééquilibrage des transformations urbaines. Comment les grands projets urbains sont-ils conceptuellement élaborés ? Comment les alliances d’acteurs qui les soutiennent se forgent-elles ? Comment les citoyens et les groupes sociaux sont-ils impliqués de manière à produire de nouveaux espaces plus intégrés ?At the beginning of the 21st century, urban spaces can be said to be in a stage of growth and radical transformation. Cities are highly expansive, both in scale and scope. The spatial configuration of urban spaces is, however, becoming more and more decentralised and fragmentary. The traditional dichotomy between urban hierarchy and periphery is disappearing. New metropolitan spaces are characterised by distance related processes of social and economic specialisation and segmentation, and often also by splitting social polarisation. The planning agendas in city regions are trying to make add more balance to the

  12. Implications of urban structure on carbon consumption in metropolitan areas

    International Nuclear Information System (INIS)

    Heinonen, Jukka; Junnila, Seppo

    2011-01-01

    Urban structure influences directly or indirectly the majority of all green house gas (GHG) emissions in cities. The prevailing belief is that dense metropolitan areas produce less carbon emissions on a per capita basis than less dense surrounding rural areas. Consequently, density targets have a major role in low-carbon urban developments. However, based on the results of this study, the connection seems unclear or even nonexistent when comprehensive evaluation is made. In this letter, we propose a hybrid life cycle assessment (LCA) method for calculating the consumption-based carbon footprints in metropolitan areas, i.e. carbon consumption, with the emphasis on urban structures. The method is input-output-based hybrid LCA, which operates with the existing data from the region. The study is conducted by performing an analysis of the carbon consumption in two metropolitan areas in Finland, including 11 cities. Both areas consist of a dense city core and a less dense surrounding suburban area. The paper will illustrate that the influence of urban density on carbon emissions is insignificant in the selected metropolitan areas. In addition, the utilized consumption-based method links the climate effects of city-level development to the global production of emissions.

  13. Governing metropolitan green infrastructure in the United States

    Science.gov (United States)

    Robert F. Young; E. Gregory McPherson

    2013-01-01

    In this paper we explore whether the enhancement of urban ecosystem services through largescale metropolitan treeplanting initiatives is being planned and executed as a component of traditional municipal government or represents new transdisciplinary strategies in environmental governance Drawing on qualitative interviews with...

  14. Disparities in Salaries: Metropolitan versus Nonmetropolitan Community College Faculty

    Science.gov (United States)

    Glover, Louis C.; Simpson, Lynn A.; Waller, Lee Rusty

    2009-01-01

    This article explores disparities in faculty salaries between metropolitan and nonmetropolitan Texas community colleges. The analysis reveals a significant difference in faculty salaries for the 2000 and 2005 academic years respectively. The study found no significant difference in the rate of change in faculty salaries from 2000 to 2005.…

  15. Is There a Global Role for Metropolitan City Libraries?

    Science.gov (United States)

    Mason, Marilyn Gell

    1994-01-01

    Discusses the potential for linking large metropolitan public libraries to international interlibrary loan networks. Issues involved in international networking, including funding, standards, network connectivity, and protectionism, are discussed. Examples of libraries capable of participating and brief descriptions of their collections are given.…

  16. Designing metropolitan landscapes for biodiversity: deriving guidelines from metapopulation ecology

    NARCIS (Netherlands)

    Opdam, P.F.M.; Steingröver, E.G.

    2008-01-01

    The decentralization of planning is giving local planning groups more power in decision making on the spatial development of metropolitan landscapes. However, because scientific knowledge is rarely used in these decision-making processes, there is a risk of discrepancies between the conservation

  17. The Tshwane metropolitan municipality and strategic partnerships in ...

    African Journals Online (AJOL)

    ... Tshwane Metropolitan Municipality commissioned research to investigate the potential of strategic partnerships for the optimal facilitation and co-operative governance of sport and recreation. The aim of this project was to identify the possible structure and nature of partnerships in order to facilitate effective management, ...

  18. Residential fencing in a metropolitan area and three small towns.

    Science.gov (United States)

    Edwin Kallio; Jerry A. Sesco

    1967-01-01

    Many types of fences were found on residential lots in the metropolitan-suburban area of St. Louis County, Missouri, and three small towns in southern Illinois. Wire fences predominated. More wooden fences were found on village lots than on city lots. In general, the more expensive homes had the most wooden fencing. Homes over 5 years old had more fencing of all...

  19. OXYGEN TRANSFER STUDIES AT THE MADISON METROPOLITAN SEWERAGE DISTRICT FACILITIES

    Science.gov (United States)

    Field studies at the Madison Metropolitan Sewerage District facilities were conducted over a 3-year period to obtain long-term data on the performance of fine pore aeration equipment in municipal wastewater. The studies were conducted on several basins in the East Plant containi...

  20. 40 CFR 81.17 - Metropolitan Los Angeles Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Regions § 81.17 Metropolitan Los Angeles Air Quality Control Region. The Metropolitan Los Angeles Air Quality Control Region consists of the following territorial area (including the territorial... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Metropolitan Los Angeles Air Quality...

  1. 23 CFR 450.336 - Applicability of NEPA to metropolitan transportation plans and programs.

    Science.gov (United States)

    2010-04-01

    ... the Secretary concerning a metropolitan transportation plan or TIP developed through the processes... 23 Highways 1 2010-04-01 2010-04-01 false Applicability of NEPA to metropolitan transportation... TRANSPORTATION PLANNING AND RESEARCH PLANNING ASSISTANCE AND STANDARDS Metropolitan Transportation Planning and...

  2. 40 CFR 81.38 - Metropolitan Houston-Galveston Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Metropolitan Houston-Galveston... Designation of Air Quality Control Regions § 81.38 Metropolitan Houston-Galveston Intrastate Air Quality Control Region. The Metropolitan Houston-Galveston Intrastate Air Quality Control Region (Texas) has been...

  3. 40 CFR 81.63 - Metropolitan Fort Smith Interstate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Metropolitan Fort Smith Interstate Air... Air Quality Control Regions § 81.63 Metropolitan Fort Smith Interstate Air Quality Control Region. The Metropolitan Fort Smith Interstate Air Quality Control Region (Arkansas-Oklahoma) has been revised to consist...

  4. Creep-fatigue interaction at high temperature; Proceedings of the Symposium, 112th ASME Winter Annual Meeting, Atlanta, GA, Dec. 1-6, 1991

    Science.gov (United States)

    Haritos, George K.; Ochoa, O. O.

    Various papers on creep-fatigue interaction at high temperature are presented. Individual topics addressed include: analysis of elevated temperature fatigue crack growth mechanisms in Alloy 718, physically based microcrack propagation laws for creep-fatigue-environment interaction, in situ SEM observation of short fatigue crack growth in Waspaloy at 700 C under cyclic and dwell conditions, evolution of creep-fatigue life prediction models, TMF design considerations in turbine airfoils of advanced turbine engines. Also discussed are: high temperature fatigue life prediction computer code based on the total strain version of strainrange partitioning, atomic theory of thermodynamics of internal variables, geometrically nonlinear analysis of interlaminar stresses in unsymmetrically laminated plates subjected to uniform thermal loading, experimental investigation of creep crack tip deformation using moire interferometry. (For individual items see A93-31336 to A93-31344)

  5. ASSOCIATIONS BETWEEN OUTDOOR PARTICULATE (PM2.5) CONCENTRATIONS AND GASEOUS CO-POLLUTANT EXPOSURE LEVELS FOR COPD AND MI COHORTS IN ATLANTA, GA

    Science.gov (United States)

    Epidemiological studies indicate that daily ambient particulate matter (PM2.5) concentrations are associated with increased mortality, hospital admissions, and respiratory and cardiovascular effects. It is possible that the observed significant associations are the result of c...

  6. AlGaN/GaN double-channel HEMT

    International Nuclear Information System (INIS)

    Quan Si; Hao Yue; Ma Xiaohua; Zheng Pengtian; Xie Yuanbin

    2010-01-01

    The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported. Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure. The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region. The buffer trap is suggested to be related to the wide region of high transconductance. The RF characteristics are also studied. (semiconductor devices)

  7. Revenues for Education in Metropolitan Areas. Chapter VI, Metropolitanism: Its Challenge to Education, 1968. Sixty-seventh Yearbook, Part I.

    Science.gov (United States)

    Alkin, Marvin C.

    For local school districts to provide equal educational opportunities throughout a metropolitan area, a school organization plan should distribute populations among districts in such a manner as to maximize the aggregate expressed demand for educational services and to provide relatively equal financial support. Consolidation of contiguous…

  8. Comparison of trap characteristics between AlGaN/GaN and AlGaN/InGaN/GaN heterostructure by frequency dependent conductance measurement

    International Nuclear Information System (INIS)

    Chakraborty, Apurba; Biswas, Dhrubes

    2015-01-01

    Frequency dependent conductance measurement is carried out to observe the trapping effect in AlGaN/InGaN/GaN double heterostructure and compared that with conventional AlGaN/GaN single heterostructure. It is found that the AlGaN/InGaN/GaN diode structure does not show any trapping effect, whereas single heterostructure AlGaN/GaN diode suffers from two kinds of trap energy states in near depletion to higher negative voltage bias region. This conductance behaviour of AlGaN/InGaN/GaN heterostructure is owing to more Fermi energy level shift from trap energy states at AlGaN/InGaN junction compare to single AlGaN/GaN heterostructure and eliminates the trapping effects. Analysis yielded interface trap energy state in AlGaN/GaN is to be with time constant of (33.8–76.5) μs and trap density of (2.38–0.656) × 10 12  eV −1  cm −2 in −3.2 to −4.8 V bias region, whereas for AlGaN/InGaN/GaN structure no interface energy states are found and the extracted surface trap energy concentrations and time constants are (5.87–4.39) ×10 10  eV −1  cm −2 and (17.8–11.3) μs, respectively, in bias range of −0.8–0.0 V

  9. Assessment of flood risk in Tokyo metropolitan area

    Science.gov (United States)

    Hirano, J.; Dairaku, K.

    2013-12-01

    Flood is one of the most significant natural hazards in Japan. The Tokyo metropolitan area has been affected by several large flood disasters. Therefore, investigating potential flood risk in Tokyo metropolitan area is important for development of adaptation strategy for future climate change. We aim to develop a method for evaluating flood risk in Tokyo Metropolitan area by considering effect of historical land use and land cover change, socio-economic change, and climatic change. Ministry of land, infrastructure, transport and tourism in Japan published 'Statistics of flood', which contains data for flood causes, number of damaged houses, area of wetted surface, and total amount of damage for each flood at small municipal level. By using these flood data, we estimated damage by inundation inside a levee for each prefecture based on a statistical method. On the basis of estimated damage, we developed flood risk curves in the Tokyo metropolitan area, representing relationship between damage and exceedance probability of flood for the period 1976-2008 for each prefecture. Based on the flood risk curve, we attempted evaluate potential flood risk in the Tokyo metropolitan area and clarify the cause for regional difference of flood risk. By analyzing flood risk curves, we found out regional differences of flood risk. We identified high flood risk in Tokyo and Saitama prefecture. On the other hand, flood risk was relatively low in Ibaraki and Chiba prefecture. We found that these regional differences of flood risk can be attributed to spatial distribution of entire property value and ratio of damaged housing units in each prefecture.We also attempted to evaluate influence of climate change on potential flood risk by considering variation of precipitation amount and precipitation intensity in the Tokyo metropolitan area. Results shows that we can evaluate potential impact of precipitation change on flood risk with high accuracy by using our methodology. Acknowledgments

  10. 2015 Lowndes County (GA) Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: NOAA OCM Lidar for Lowndes County, GA with the option to Collect Lidar in Cook and Tift Counties, GA Lidar Data Acquisition and Processing Production Task...

  11. ELECTRICITY DEMAND IN A NORTHERN MEXICO METROPOLITAN ECONOMY

    Directory of Open Access Journals (Sweden)

    Thomas M. Fullerton

    2014-10-01

    Full Text Available Using an error correction framework, this study analyzes the long- and short-run dynamics of electricity demand in Ciudad Juarez, a large metropolitan economy on Mexico’s northern border. Demand is decomposed into the total number of electricity accounts and electricity usage per customer, each of which is modeled separately. A two-stage least squares approach is used to estimate the per customer electricity demand equations due to the endogeneity of the average price variable. The results indicate sustained growth in population, employment, and income can be expected to exert substantial upward pressure on regional electric power demand. Furthermore, demand is found to be price-inelastic in this metropolitan area, suggesting that rate increases can help raise the revenues necessary to fund expansion of the electrical grid.

  12. Analysis of Solid Waste Management and Strategies for Bangkok Metropolitan

    Directory of Open Access Journals (Sweden)

    Palika Wannawilai

    2017-04-01

    Full Text Available This study aimed to examine and analyze strategic gaps and the environment of waste management of Bangkok Metropolitan Administration (BMA in order to suggest suitable waste management strategies for Bangkok Metropolitan. The study was conducted by interviewing BMA and districts’ administrators and officers, local leaders and people, and private sectors, conducting a focus group, as well as reviewing relevant documents. The data was analyzed by applying Gap analysis and SWOT analysis. The proposed five strategies are: 1 enhancement of efficiency in solid waste and hazardous waste management; 2 discipline, participation and responsibility of citizens and all sectors related to waste management; 3 appropriate and integrated waste management; 4 capacity building for BMA’s staff and improvement of solid waste management system; and 5 research and development of knowledge and technology in waste management. The study also suggested driving approaches for effective implementation of the strategies.

  13. Use of renewable energy in the greater metropolitan area

    International Nuclear Information System (INIS)

    Arias Garcia, Rocio; Castro Gomez, Gustavo; Fallas Cordero, Kenneth; Grant Chaves, Samuel; Mendez Parrales, Tony; Parajeles Fernandez, Ivan

    2012-01-01

    A study is conducted on different renewable energy within the larger metropolitan area, selecting the most suitable for the area and the implementation for distributed generation. A research methodology is practiced type pretending gather the necessary information to make proposals selected of different type of energy. The geography of the greater metropolitan area is studied along with the different existing renewable energy: distributed generation, remote measurement of energy which is one of the elements of the concept of intelligent networks (Smart Grid) in the electricity sector, legislation of Costa Rica regarding the generation of renewable energy and environmental impact. An analysis of economic feasibility is covered for each of the proposals estimating current rates for leading distributors of a future value, concluding with the viability of projects for possible execution of the same. (author) [es

  14. Urbanisation, urban growth and planning in the Copenhagen Metropolitan Region

    DEFF Research Database (Denmark)

    Fertner, Christian

    pressure. Growth management strategies are necessary to secure future balanced and sustainable development throughout the whole urban region. The analysis of urbanisation and urban growth in peri-urban areas is at the core of this study, including socio-demographic and functional dynamics, land use impacts...... and options for spatial planning. The main case was the metropolitan region of Copenhagen, Denmark. Other cases from Europe and the USA were used as reference studies. The methods included quantitative analyses of register and land use data as well as general case study work to investigate options for spatial...... planning. The study shows that, while the most visible impacts of land use changes can be found at the close urban fringe, many other dynamics have a much longer reach into the rural-urban region. In the Copenhagen metropolitan region, we can observe migration to peri-urban areas and to the urban core...

  15. FINANCING FARMLAND PRESERVATION: THE TWIN CITIES METROPOLITAN AREA EXPERIENCE

    OpenAIRE

    Greden, Leah R.; Taff, Steven J.

    1994-01-01

    Two farmland protection programs in the Twin Cities (Minnesota) Metropolitan Area--Green Acres and Agricultural Preserves-- together enrolled 608,331 acres in 1992. The principal financing tool was a provision common to both programs under which participating landowners paid reduced property taxes in exchange for certain non- development assurances. The resulting shift in property tax obligations to other taxpayers amounted to $7.6 million for the 1993 tax year, an average shift of $12.50 per...

  16. Skinner boxes for psychotics: Operant conditioning at Metropolitan state hospital

    OpenAIRE

    Rutherford, Alexandra

    2003-01-01

    Between 1953 and 1965, Ogden Lindsley and his associates conducted free-operant research with psychiatric inpatients and normal volunteers at Metropolitan State Hospital in Waltham, Massachusetts. Their project, originally named “Studies in Behavior Therapy,” was renamed “Harvard Medical School Behavior Research Laboratory” in 1955. This name change and its implications were significant. The role of the laboratory in the history of the relationship between the experimental analysis of behavio...

  17. SPATIAL SEGMENTATION WITHIN METROPOLITAN LABOUR MARKET: MAPPING THE GENDER DIMENSION

    OpenAIRE

    DEBNATH, TANIA

    2017-01-01

    Spatial segmentation of the labour market of informal workers within the metropolitan is observed globally. InIndia it is not only compartmentalised on gender, caste, ethnic lines but also geographically segmented by thecreation of spatially disjoined markets. The differential impact of this limited mobility on female and malelabour remains largely unexplored. The present paper argues that the labour market for informal workers issegmented into smaller labour markets separated by commuting (h...

  18. Factors Influencing Patronage Of Medical Tourism In Metropolitan Lagos Nigeria

    OpenAIRE

    Omisore; E.O.; Agbabiaka; H. I.

    2015-01-01

    Since medical tourism attract patient from various origin to seek medical services at different destinations it is paramount to consider the factors that motivate patrons decision on medical tourism. Hence this study assesses the factors influencing patronage of medical tourism in Lagos metropolis Nigeria. Lagos State is situated in the southwestern corner of Nigeria it lies within Latitudes 62N to 64N of the Equator and Longitudes 245E to 420E of the Greenwich meridian. Metropolitan Lagos is...

  19. The determinants of part-time work in Metropolitan Lima

    OpenAIRE

    Manuel Enrique Saavedra Martinez

    2011-01-01

    The following paper examines the part-time work in Metropolitan Lima in 2008. The overall objective is to identify the determinants of the incidence of part-time work in Lima. We worked with one Probit econometric model, measured by the National Survey of Households (NSH), which explores the job characteristics of people. This will determine the presence of part-time workers in the areas of trade, health, education and communication; also realized that this group has completed university stud...

  20. The determinants of part-time work in Metropolitan Lima

    OpenAIRE

    Saavedra Martinez, Manuel Enrique

    2012-01-01

    The following paper examines the part-time work in Metropolitan Lima in 2008. The overall objective is to identify the determinants of the incidence of part-time work in Lima. We worked with one Probit econometric model, measured by the National Survey of Households (NSH), which explores the job characteristics of people. This will determine the presence of part-time workers in the areas of trade, health, education and communication; also realized that this group has completed university stud...

  1. The 1987 Whittier Narrows, California, earthquake: A Metropolitan shock

    OpenAIRE

    Hauksson, Egill; Stein, Ross S.

    1989-01-01

    Just 3 hours after the Whittier Narrows earthquake struck, it became clear that a heretofore unseen geological structure was seismically active beneath metropolitan Los Angeles. Contrary to initial expectations of strike-slip or oblique-slip motion on the Whittier fault, whose north end abuts the aftershock zone, the focal mechanism of the mainshock showed pure thrust faulting on a deep gently inclined surface [Hauksson et al., 1988]. This collection of nine research reports spans the spectru...

  2. Green Urbanism for the Greener Future of Metropolitan Areas

    Science.gov (United States)

    Zaręba, Anna; Krzemińska, Alicja; Widawski, Krzysztof

    2016-10-01

    Intensive urbanization is swallowing municipal green areas which causes intensification of erosion, decrease in biodiversity and permanent fragmentation of habitats. In the face of these changes, a risk of irreversible damages to urban ecosystems is growing. That is why planning of solutions within the framework of Green Urbanism in metropolitan areas inhabited by over 55% of the global population is of extraordinary importance. The task of the paper is to present patterns of the Green Urbanism using selected examples of metropolitan areas as case studies. The main goal of the research is to make comparison between GU practices in different countries, in various spatial settings. The principles of triple zero framework: zero fossil-fuel energy use, zero waste, zero emissions (from low-to-no-carbon emissions) introduce not only the contemporary trends in theoretical urban planning but are dictated by practical considerations to create a healthy environment for a healthy society with a minimized environmental footprint. The research results help to identify Green Urbanism techniques used for multiple functions, including ecological, recreational, cultural, aesthetic and other uses and present opportunities for implementation of Green Urbanism solutions in metropolitan areas. To achieve healthier society and environment, highly congested and polluted cities have to be recreated through working with the existing landscape, topography and natural resources particular to the site.

  3. Uber and Metropolitan Traffic Fatalities in the United States.

    Science.gov (United States)

    Brazil, Noli; Kirk, David S

    2016-08-01

    Uber and similar rideshare services are rapidly dispersing in cities across the United States and beyond. Given the convenience and low cost, Uber has been characterized as a potential countermeasure for reducing the estimated 121 million episodes of drunk driving and the 10,000 resulting traffic fatalities that occur annually in the United States. We exploited differences in the timing of the deployment of Uber in US metropolitan counties from 2005 to 2014 to test the association between the availability of Uber's rideshare services and total, drunk driving-related, and weekend- and holiday-specific traffic fatalities in the 100 most populated metropolitan areas in the United States using negative binomial and Poisson regression models. We found that the deployment of Uber services in a given metropolitan county had no association with the number of subsequent traffic fatalities, whether measured in aggregate or specific to drunk-driving fatalities or fatalities during weekends and holidays. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Twelve metropolitan carbon footprints. A preliminary comparative global assessment

    International Nuclear Information System (INIS)

    Sovacool, Benjamin K.; Brown, Marilyn A.

    2010-01-01

    A dearth of available data on carbon emissions and comparative analysis between metropolitan areas make it difficult to confirm or refute best practices and policies. To help provide benchmarks and expand our understanding of urban centers and climate change, this article offers a preliminary comparison of the carbon footprints of 12 metropolitan areas. It does this by examining emissions related to vehicles, energy used in buildings, industry, agriculture, and waste. The carbon emissions from these sources - discussed here as the metro area's partial carbon footprint - provide a foundation for identifying the pricing, land use, help metropolitan areas throughout the world respond to climate change. The article begins by exploring a sample of the existing literature on urban morphology and climate change and explaining the methodology used to calculate each area's carbon footprint. The article then depicts the specific carbon footprints for Beijing, Jakarta, London, Los Angeles, Manila, Mexico City, New Delhi, New York, Sao Paulo, Seoul, Singapore, and Tokyo and compares these to respective national averages. It concludes by offering suggestions for how city planners and policymakers can reduce the carbon footprint of these and possibly other large urban areas. (author)

  5. Is Urban Planning in Australia Hindered by Poor Metropolitan Governance?

    Directory of Open Access Journals (Sweden)

    Paul Burton

    2017-11-01

    Full Text Available There are many calls for urban planning in Australia to be reformed, although often in contradictory ways. For example, some argue it should be capable of delivering greater certainty to developers while others call for more flexibility in processes of urban development regulation; some would like to roll back its regulatory impact while others argue for a renewal of planning’s commitment to promoting social and spatial justice. The Australian planning system is also held to be hindered by a comparative lack of planning at and for the metropolitan scale. This is connected to the absence of well-developed structures of metropolitan governance in what is a three-tier federal system, with most power over planning concentrated at the State and Territory government scale. The paper explores this putative hindrance by considering three important issues in Australian urban policy debates about the efficacy of contemporary multi-level governance arrangements: spatial scale; identity and legitimacy; and efficiency and effectiveness. It includes some analysis of the case made for a more explicit and rigorous national urban policy and how this might relate to lower level planning regimes. The paper focuses on recent urban policy and planning initiatives in South East Queensland, one of Australia’s fastest growing metropolitan regions, and concludes that while incremental but nonetheless significant improvements in planning policy and practice are possible, these are unlikely to satisfy those calling for more radical changes to improve the Australian planning system.

  6. Strain Balanced AlGaN/GaN/AlGaN nanomembrane HEMTs.

    Science.gov (United States)

    Chang, Tzu-Hsuan; Xiong, Kanglin; Park, Sung Hyun; Yuan, Ge; Ma, Zhenqiang; Han, Jung

    2017-07-25

    Single crystal semiconductor nanomembranes (NM) are important in various applications such as heterogeneous integration and flexible devices. This paper reports the fabrication of AlGaN/GaN NMs and NM high electron mobility transistors (HEMT). Electrochemical etching is used to slice off single-crystalline AlGaN/GaN layers while preserving their microstructural quality. A double heterostructure design with a symmetric strain profile is employed to ensure minimal residual strain in freestanding NMs after release. The mobility of the two-dimensional electron gas (2DEG), formed by the AlGaN/GaN heterostructure, is noticeably superior to previously reported values of many other NMs. AlGaN/GaN nanomembrane HEMTs are fabricated on SiO 2 and flexible polymeric substrates. Excellent electrical characteristics, including a high ON/OFF ratio and transconductance, suggest that III-Nitrides nanomembranes are capable of supporting high performance applications.

  7. Urban Growth Areas, This Layer represents the current Urbanized Area for Atlanta as defined by the U.S. Census Bureau. An Urbanized Area is a concept used by the U.S. Census Bureau to measure the population, land area and population density of a built-up or continuously deve, Published in 2000, 1:100000 (1in=8333ft) scale, Atlanta Regional Commission.

    Data.gov (United States)

    NSGIC Regional | GIS Inventory — Urban Growth Areas dataset current as of 2000. This Layer represents the current Urbanized Area for Atlanta as defined by the U.S. Census Bureau. An Urbanized Area...

  8. Source apportionment of submicron organic aerosol collected from Atlanta, Georgia, during 2014-2015 using the aerosol chemical speciation monitor (ACSM)

    Science.gov (United States)

    Rattanavaraha, Weruka; Canagaratna, Manjula R.; Budisulistiorini, Sri Hapsari; Croteau, Philip L.; Baumann, Karsten; Canonaco, Francesco; Prevot, Andre S. H.; Edgerton, Eric S.; Zhang, Zhenfa; Jayne, John T.; Worsnop, Douglas R.; Gold, Avram; Shaw, Stephanie L.; Surratt, Jason D.

    2017-10-01

    The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) was redeployed at the Jefferson Street (JST) site in downtown Atlanta, Georgia (GA) for 1 year (March 20, 2014-February 08, 2015) to chemically characterize non-refractory submicron particulate matter (NR-PM1) in near real-time and to assess whether organic aerosol (OA) types and amounts change from year-to-year. Submicron organic aerosol (OA) mass spectra were analyzed by season using multilinear engine (ME-2) to apportion OA subtypes to potential sources and chemical processes. A suite of real-time collocated measurements from the Southeastern Aerosol Research and Characterization (SEARCH) network was compared with ME-2 factor solutions to aid in the interpretation of OA subtypes during each season. OA tracers measured from high-volume filter samples using gas chromatography interfaced with electron ionization-mass spectrometry (GC/EI-MS) also aided in identifying OA sources. The initial application of ME-2 to the yearlong ACSM dataset revealed that OA source apportionment by season was required to better resolve sporadic OA types. Spring and fall OA mass spectral datasets were separated into finer periods to capture potential OA sources resulting from non-homogeneous emissions during transitioning periods. NR-PM1 was highest in summer (16.7 ± 8.4 μg m-3) and lowest in winter (8.0 ± 5.7 μg m-3), consistent with prior studies. OA dominated NR-PM1 mass (56-74% on average) in all seasons. Hydrocarbon-like OA (HOA) from primary emissions was observed in all seasons, averaging 5-22% of total OA mass. Strong correlations of HOA with carbon monoxide (CO) (R = 0.71-0.88) and oxides of nitrogen (NOx) (R = 0.55-0.79) indicated that vehicular traffic was the likely source. Biomass burning OA (BBOA) was observed in all seasons, with lower contributions (2%) in summer and higher in colder seasons (averaging 8-20% of total OA mass). BBOA correlated strongly with levoglucosan (R = 0.78-0.95) during colder seasons

  9. Tokyo Metropolitan Earthquake Preparedness Project - A Progress Report

    Science.gov (United States)

    Hayashi, H.

    2010-12-01

    Munich Re once ranked that Tokyo metropolitan region, the capital of Japan, is the most vulnerable area for earthquake disasters, followed by San Francisco Bay Area, US and Osaka, Japan. Seismologists also predict that Tokyo metropolitan region may have at least one near-field earthquake with a probability of 70% for the next 30 years. Given this prediction, Japanese Government took it seriously to conduct damage estimations and revealed that, as the worst case scenario, if a7.3 magnitude earthquake under heavy winds as shown in the fig. 1, it would kill a total of 11,000 people and a total of direct and indirect losses would amount to 112,000,000,000,000 yen(1,300,000,000,000, 1=85yen) . In addition to mortality and financial losses, a total of 25 million people would be severely impacted by this earthquake in four prefectures. If this earthquake occurs, 300,000 elevators will be stopped suddenly, and 12,500 persons would be confined in them for a long time. Seven million people will come to use over 20,000 public shelters spread over the impacted area. Over one millions temporary housing units should be built to accommodate 4.6 million people who lost their dwellings. 2.5 million people will relocate to outside of the damaged area. In short, an unprecedented scale of earthquake disaster is expected and we must prepare for it. Even though disaster mitigation is undoubtedly the best solution, it is more realistic that the expected earthquake would hit before we complete this business. In other words, we must take into account another solution to make the people and the assets in this region more resilient for the Tokyo metropolitan earthquake. This is the question we have been tackling with for the last four years. To increase societal resilience for Tokyo metropolitan earthquake, we adopted a holistic approach to integrate both emergency response and long-term recovery. There are three goals for long-term recovery, which consists of Physical recovery, Economic

  10. Earthquake Risk Mitigation in the Tokyo Metropolitan area

    Science.gov (United States)

    Hirata, N.; Sakai, S.; Kasahara, K.; Nakagawa, S.; Nanjo, K.; Panayotopoulos, Y.; Tsuruoka, H.

    2010-12-01

    Seismic disaster risk mitigation in urban areas constitutes a challenge through collaboration of scientific, engineering, and social-science fields. Examples of collaborative efforts include research on detailed plate structure with identification of all significant faults, developing dense seismic networks; strong ground motion prediction, which uses information on near-surface seismic site effects and fault models; earthquake resistant and proof structures; and cross-discipline infrastructure for effective risk mitigation just after catastrophic events. Risk mitigation strategy for the next greater earthquake caused by the Philippine Sea plate (PSP) subducting beneath the Tokyo metropolitan area is of major concern because it caused past mega-thrust earthquakes, such as the 1703 Genroku earthquake (magnitude M8.0) and the 1923 Kanto earthquake (M7.9) which had 105,000 fatalities. A M7 or greater (M7+) earthquake in this area at present has high potential to produce devastating loss of life and property with even greater global economic repercussions. The Central Disaster Management Council of Japan estimates that the M7+ earthquake will cause 11,000 fatalities and 112 trillion yen (about 1 trillion US$) economic loss. This earthquake is evaluated to occur with a probability of 70% in 30 years by the Earthquake Research Committee of Japan. In order to mitigate disaster for greater Tokyo, the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan Area (2007-2011) was launched in collaboration with scientists, engineers, and social-scientists in nationwide institutions. The results that are obtained in the respective fields will be integrated until project termination to improve information on the strategy assessment for seismic risk mitigation in the Tokyo metropolitan area. In this talk, we give an outline of our project as an example of collaborative research on earthquake risk mitigation. Discussion is extended to our effort in progress and

  11. Pol?tica migratoria y condiciones laborales: un estudio de caso comparado acerca de los colombianos en situaci?n irregular en las ciudades de Atlanta y Miami

    OpenAIRE

    Parra Mora, Laura Camila

    2016-01-01

    Este trabajo tiene por objetivo determinar la incidencia de las pol?ticas migratorias de las administraciones Bush y Obama en las condiciones laborales de los colombianos indocumentados en las ciudades de Atlanta y Miami. La hip?tesis planteada afirma que la transici?n que ha tenido la pol?tica migratoria estadounidense, ha deteriorado las condiciones laborales de los colombianos indocumentados. El art?culo se divide en cuatro apartados. Primeramente, define los aspectos conceptuales a tener ...

  12. Polarization-engineered GaN/InGaN/GaN tunnel diodes

    International Nuclear Information System (INIS)

    Krishnamoorthy, Sriram; Nath, Digbijoy N.; Akyol, Fatih; Park, Pil Sung; Esposto, Michele; Rajan, Siddharth

    2010-01-01

    We report on the design and demonstration of polarization-engineered GaN/InGaN/GaN tunnel junction diodes with high current density and low tunneling turn-on voltage. Wentzel-Kramers-Brillouin calculations were used to model and design tunnel junctions with narrow band gap InGaN-based barrier layers. N-polar p-GaN/In 0.33 Ga 0.67 N/n-GaN heterostructure tunnel diodes were grown using molecular beam epitaxy. Efficient interband tunneling was achieved close to zero bias with a high current density of 118 A/cm 2 at a reverse bias of 1 V, reaching a maximum current density up to 9.2 kA/cm 2 . These results represent the highest current density reported in III-nitride tunnel junctions and demonstrate the potential of III-nitride tunnel devices for a broad range of optoelectronic and electronic applications.

  13. The mobility of food retailers: How proximity to SNAP authorized food retailers changed in Atlanta during the Great Recession.

    Science.gov (United States)

    Shannon, Jerry; Bagwell-Adams, Grace; Shannon, Sarah; Lee, Jung Sun; Wei, Yangjiaxin

    2018-07-01

    Retailer mobility, defined as the shifting geographic patterns of retail locations over time, is a significant but understudied factor shaping neighborhood food environments. Our research addresses this gap by analyzing changes in proximity to SNAP authorized chain retailers in the Atlanta urban area using yearly data from 2008 to 2013. We identify six demographically similar geographic clusters of census tracts in our study area based on race and economic variables. We use these clusters in exploratory data analysis to identify how proximity to the twenty largest retail food chains changed during this period. We then use fixed effects models to assess how changing store proximity is associated with race, income, participation in SNAP, and population density. Our results show clear differences in geographic distribution between store categories, but also notable variation within each category. Increasing SNAP enrollment predicted decreased distances to almost all small retailers but increased distances to many large retailers. Our chain-focused analysis underscores the responsiveness of small retailers to changes in neighborhood SNAP participation and the value of tracking chain expansion and contraction in markets across time. Better understanding of retailer mobility and the forces that drive it can be a productive avenue for future research. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Evaluation of two-year Jewish genetic disease screening program in Atlanta: insight into community genetic screening approaches.

    Science.gov (United States)

    Shao, Yunru; Liu, Shuling; Grinzaid, Karen

    2015-04-01

    Improvements in genetic testing technologies have led to the development of expanded carrier screening panels for the Ashkenazi Jewish population; however, there are major inconsistencies in current screening practices. A 2-year pilot program was launched in Atlanta in 2010 to promote and facilitate screening for 19 Jewish genetic diseases. We analyzed data from this program, including participant demographics and outreach efforts. This retrospective analysis is based on a de-identified dataset of 724 screenees. Data were obtained through medical chart review and questionnaires and included demographic information, screening results, response to outreach efforts, and follow-up behavior and preferences. We applied descriptive analysis, chi-square tests, and logistic regression to analyze the data and compare findings with published literature. The majority of participants indicated that they were not pregnant or did not have a partner who was pregnant were affiliated with Jewish organizations and reported 100 % AJ ancestry. Overall, carrier frequency was 1 in 3.9. Friends, rabbis, and family members were the most common influencers of the decision to receive screening. People who were older, had a history of pregnancy, and had been previously screened were more likely to educate others (all p influencers who then encouraged screening in the target population. Educating influencers and increasing overall awareness were the most effective outreach strategies.

  15. Antisites and anisotropic diffusion in GaAs and GaSb

    KAUST Repository

    Tahini, H. A.; Bracht, H.; Chroneos, Alexander; Grimes, R. W.; Murphy, S. T.; Schwingenschlö gl, Udo

    2013-01-01

    The significant diffusion of Ga under Ga-rich conditions in GaAs and GaSb is counter intuitive as the concentration of Ga vacancies should be depressed although Ga vacancies are necessary to interpret the experimental evidence for Ga transport

  16. Comparison of daytime and night-time populations adjacent to interstate highways in metropolitan areas

    International Nuclear Information System (INIS)

    Mills, G.S.; Neuhauser, K.S.

    1999-01-01

    Daytime and night-time population densities bordering Interstate highway routes in metropolitan areas are compared at the traffic analysis zone level. In three of the metropolitan areas studied, histograms of daytime to night-time population density ratios are peaked at 1.0. In a smaller metropolitan area, the peak of the histogram moves to values greater than 1.0 but less than 2.0. In view of the typical uncertainties in calculating radiological transport effects (∼2), this study indicates that a distinction between daytime and night-time transport is not warranted, especially since a typical route includes extensive transport outside metropolitan areas. (author)

  17. Heterogeneous Structure and Seismicity beneath the Tokyo Metropolitan Area

    Science.gov (United States)

    Nakagawa, S.; Kato, A.; Sakai, S.; Nanjo, K.; Panayotopoulos, Y.; Kurashimo, E.; Obara, K.; Kasahara, K.; Aketagawa, T.; Kimura, H.; Hirata, N.

    2010-12-01

    Beneath the Tokyo metropolitan area, the Philippine Sea Plate (PSP) subducts and causes damaged mega-thrust earthquakes. Sato et al. (2005) revealed the geometry of upper surface of PSP, and Hagiwara et al. (2006) estimated the velocity structure beneath Boso peninsula. However, these results are not sufficient for the assessment of the entire picture of the seismic hazards beneath the Tokyo metropolitan area including those due to an intra-slab M7+ earthquake. So, we launched the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan area (Hirata et al., 2009). Proving the more detailed geometry and physical properties (e.g. velocities, densities, attenuation) and stress field within PSP is very important to attain this issue. The core item of this project is a dense seismic array called Metropolitan Seismic Observation network (MeSO-net) for making observations in the metropolitan area (Sakai and Hirata, 2009; Kasahara et al., 2009). We deployed the 249 seismic stations with a spacing of 5 km. Some parts of stations construct 5 linear arrays at interval of 2 km such as Tsukuba-Fujisawa (TF) array, etc. The TF array runs from northeast to southwest through the center of Tokyo. In this study, we applied the tomography method to image the heterogeneous structure under the Tokyo metropolitan area. We selected events from the Japan Meteorological Agency (JMA) unified earthquake list. All data of MeSO-net were edited into event data by the selected JMA unified earthquake list. We picked the P and S wave arrival times. The total number of stations and events are 421 and 1,256, respectively. Then, we applied the double-difference tomography method (Zhang and Thurber, 2003) to this dataset and estimated the fine-scale velocity structure. The grid nodes locate 10 km interval in parallel with the array, 20 km interval in perpendicular to the array; and on depth direction, 5 km interval to a depth of less than 50 km and 10 km interval at a depth of more

  18. Ga-Bi-Te system

    International Nuclear Information System (INIS)

    Rustamov, P.G.; Seidova, N.A.; Shakhbazov, M.G.; AN Azerbajdzhanskoj SSR, Baku. Inst. Neorganicheskoj i Fizicheskoj Khimii)

    1976-01-01

    To elucidate the nature of interaction in the system Ga-Bi-Te, a study has been made of sections GaTe-Bi 2 Te 3 , Ga 2 Te 3 -Bi, GaTe-Bi and Bi 2 Te 3 -Ga. The alloys have been prepared by direct melting of the components or their alloys with subsequent homogenizin.o annealing at 400 deg C. The study has been made by the methods of differential thermal, microstructural analysis and by microhardness measurements. On the basis of literature data and data obtained a projection of the liquidus surface of the phase diagram for the system Ga-Bi-Te has been constructed. In the ternary system there are 17 curves of monovariant equilibrium dividing the liquidus into 10 fields of primary crystallization of phases, 9 points of non-variant equilibrium of which 4 points are triple eutectics and 5 points are triple peritectics

  19. Top Soils Geochemical and Radioactivity Survey of Naples (Italy) Metropolitan.

    Science.gov (United States)

    Somma, R.; De Vivo, B.; Cicchella, D.

    2001-05-01

    The metropolitan area of Naples due to intense human activities is an emblematic area affected by various environmental pollution of soils and waters in addition to hydrogeological volcanic, seismic and bradyseismic hazards. The geology of the area is prevailing represented by volcanics erupted, from the Upper Pleistocene to Recent by Mt. Somma-Vesuvius on the east and the Campi Flegrei fields on the west. The morphology of the metropolitan area of Naples city can be subdivided in flat areas, constituted by reworked pyroclastic terrains, and by hills originated by the overlapping of different welded pyroclastic flows (i.e.: Campanian Ignimbrite and Neapoletan Yellow Tuff) intercalated with pyroclastic deposits of different origins (i.e.: Campi Flegrei, Mt. Somma-Vesuvius, Ischia) and ages. In order to compile a multi-element baseline geochemical and radioactivity mapping of the metropolitan area of the Napoli we have sampled for this study, in situ top soil and imported filling material (mainly soil, volcanic ash, pumice and scoriae). The sampling and radioactivity survey has been carried out on about 200 sampling sites covering an area of about 150 Km2, with a grid of 0.5 x 0.5 km in the urbanised downtown and 1 km x 1 km in the sub urban areas. In each site has been determined a radioactivity by a Scintrex GRS-500 at different emission spectra as total radioactivity (> 0.08 MeV and > 0.40 MeV), 238U (at 1.76 MeV mostly from 214Bi), 232Th (at 2.6 MeV mostly from 208Tl) and 40K (at 1.46 MeV mostly for 40K). The range of values of in situ soils are as follow for the in situ soils (Total radioactivity: 1327- 360 and 114- 47; 238U: 2.6- 1.3; 40K: 8.1- 3.1; 232U: 0.5- 0.1). Analyses of major, metallic elements and pH of each soil sample are in progress, while Pb isotopes compositions, for a selected number of samples, will be determined to discriminate the natural (geogenic) from the anthropogenic components in the soils by versus the anthropogenetic origin. The data

  20. Urban heat island effect on cicada densities in metropolitan Seoul

    Directory of Open Access Journals (Sweden)

    Hoa Q. Nguyen

    2018-01-01

    Full Text Available Background Urban heat island (UHI effect, the ubiquitous consequence of urbanization, is considered to play a major role in population expansion of numerous insects. Cryptotympana atrata and Hyalessa fuscata are the most abundant cicada species in the Korean Peninsula, where their population densities are higher in urban than in rural areas. We predicted a positive relationship between the UHI intensities and population densities of these two cicada species in metropolitan Seoul. Methods To test this prediction, enumeration surveys of cicada exuviae densities were conducted in 36 localities located within and in the vicinity of metropolitan Seoul. Samples were collected in two consecutive periods from July to August 2015. The abundance of each species was estimated by two resource-weighted densities, one based on the total geographic area, and the other on the total number of trees. Multiple linear regression analyses were performed to identify factors critical for the prevalence of cicada species in the urban habitat. Results C. atrata and H. fuscata were major constituents of cicada species composition collected across all localities. Minimum temperature and sampling period were significant factors contributing to the variation in densities of both species, whereas other environmental factors related to urbanization were not significant. More cicada exuviae were collected in the second rather than in the first samplings, which matched the phenological pattern of cicadas in metropolitan Seoul. Cicada population densities increased measurably with the increase in temperature. Age of residential complex also exhibited a significantly positive correlation to H. fuscata densities, but not to C. atrata densities. Discussion Effects of temperature on cicada densities have been discerned from other environmental factors, as cicada densities increased measurably in tandem with elevated temperature. Several mechanisms may contribute to the abundance of

  1. Population deconcentration in metropolitan Manila in the twentieth century.

    Science.gov (United States)

    Stinner, W F; Bacol-montilla, M

    1981-10-01

    "The present analysis is intended to delineate the extent of population deconcentration through an examination of changes in core-periphery growth and density patterns within the Metropolitan Manila complex. Specifically, [the authors] examine changes in absolute and relative population growth and density levels in the central city of Manila, the inner suburban ring, and the outer suburban ring from 1903 to 1975. [The authors] also present a preliminary assessment of the demographic processes underlying the post-World War II trends." Data are from the 1975 Philippine census. excerpt

  2. Travel Models for Corridors of Metropolitan Areas Served by Railways

    Directory of Open Access Journals (Sweden)

    Brzeziński A.

    2016-12-01

    Full Text Available In recent years adverse processes of suburbanization have been observed in cities. It has become a serious challenge for urban and transport planners, as it influences largely the quality of space, the quality of life, and the cost of running the city. This paper is dedicated to travel models in areas serviced by a railway system, and is based on a real-life survey example of the Błonie community, a district belonging to the Warsaw metropolitan area. Research carried out in 2014 focused on combined travels behaviors recorded using GPS locators as well as quantitative research (volumes of users across various transport systems.

  3. The determinants of part-time work in Metropolitan Lima

    Directory of Open Access Journals (Sweden)

    Manuel Enrique Saavedra Martinez

    2011-12-01

    Full Text Available The following paper examines the part-time work in Metropolitan Lima in 2008. The overall objective is to identify the determinants of the incidence of part-time work in Lima. We worked with one Probit econometric model, measured by the National Survey of Households (NSH, which explores the job characteristics of people. This will determine the presence of part-time workers in the areas of trade, health, education and communication; also realized that this group has completed university studies and incomplete, and the woman has a probability of 83,11397% more than men of working part time.

  4. AlGaN/GaN HEMT structures on ammono bulk GaN substrate

    International Nuclear Information System (INIS)

    Kruszewski, P; Prystawko, P; Krysko, M; Smalc-Koziorowska, J; Leszczynski, M; Kasalynas, I; Nowakowska-Siwinska, A; Plesiewicz, J; Dwilinski, R; Zajac, M; Kucharski, R

    2014-01-01

    The work shows a successful fabrication of AlGaN/GaN high electron mobility transistor (HEMT) structures on the bulk GaN substrate grown by ammonothermal method providing an ultralow dislocation density of 10 4  cm −2  and wafers of size up to 2 inches in diameter. The AlGaN layers grown by metalorganic chemical vapor phase epitaxy method demonstrate atomically smooth surface, flat interfaces with reproduced low dislocation density as in the substrate. The test electronic devices—Schottky diodes and transistors—were designed without surface passivation and were successfully fabricated using mask-less laser-based photolithography procedures. The Schottky barrier devices demonstrate exceptionally low reverse currents smaller by a few orders of magnitude in comparison to the Schottky diodes made of AlGaN/GaN HEMT on sapphire substrate. (paper)

  5. InGaN/GaN Nanowire LEDs and Lasers

    KAUST Repository

    Zhao, Chao; Ng, Tien Khee; Jahangir, Shafat; Frost, Thomas; Bhattacharya, Pallab; Ooi, Boon S.

    2016-01-01

    -droop issues. The phonon and carrier confinement in nanowires also led to junction heating, and reduced heat dissipation. In this paper, we will present our studies on effective surface states passivation in InGaN/GaN quantum-disks (Qdisks)-in-nanowire light

  6. Robust AlGaN/GaN MMIC Receiver Components

    NARCIS (Netherlands)

    Heijningen, M. van; Janssen, J.P.B.; Vliet, F.E. van

    2009-01-01

    Apart from delivering very high output powers, GaN can also be used to realize robust receiver components, such as Low Noise Amplifiersand Switches. This paper presents the designand measurement results of two GaN X-band switch and LNA MMICs, designed for integration in a radar front end. The switch

  7. Spatial mismatch, wages and unemployment in metropolitan areas in Brazil

    Directory of Open Access Journals (Sweden)

    Ana Maria Bonomi Barufi

    2017-12-01

    Full Text Available The spatial mismatch hypothesis states that a lack of connection to job opportunities may affect an individual’s prospects in the labour market, especially for low-skilled workers. This phenomenon is especially observed in large urban areas, in which low-skilled minorities tend to live far away from jobs and face geographical barriers to finding and keeping jobs. This paper aims to investigate whether this negative relationship between spatial mismatch and labour market outcomes is valid in Brazil after controlling for individual characteristics. Our conclusions indicate that there is no clear relation between different measures of accessibility to jobs and the probability of being unemployed. However, for wages there is a clear correlation, which is stronger in larger metropolitan areas in the country. Given the exploratory nature of this work, our results still rely on strong identification hypotheses to avoid potential bias related to simultaneous location decisions of workers and firms within the city. Even if these conditions do not hold, the results are still meaningful as they provide a better understanding of the conditional distribution of wages and the unemployment rate in the biggest metropolitan areas of Brazil.

  8. The Audiometric Findings among Curitiba and Metropolitan Area Students

    Directory of Open Access Journals (Sweden)

    Klas, Regina

    2014-02-01

    Full Text Available Introduction Hearing loss can compromise the language, learning process, and socialization of students. Objective Study the audiometric findings among Curitiba and Metropolitan Area students. Methods Analysis of data collected at the hearing health service of Paraná State special education and inclusion department. Results The sample consisted of 646 students, children and teenagers of both genders (38.2% female and 61.8% male, with average age of 8.12 years (range 2 to 15; all were students of public or private schools of Curitiba and Metropolitan Area. The justifications to refer the students to audiometric evaluation were: otolaryngologists diagnosis (73.1%, school difficulties (39.6%, and midlevel hearing problems (32%. Audiometric results showed that 29.5% of the students had hearing loss. Conductive hearing losses showed the greatest occurrence among preschool students (right ear 38.6%, left ear 39.8%. The predominant hearing loss degree was mild (RE 20.5%, LE 19.3% to slight (RE 17%, LE 19.3%, as was the horizontal configuration (RE 81.5%, LE 78.4%. A significant relationship (p = 0.0000 between hearing loss and poor school performance was noted. Conclusion Considering the available data, especially the high number of findings of conductive losses, it is necessary to highlight prevention and diagnosis of early hearing alteration. Nevertheless, Brazil, as an emerging country, has been pursuing improvement in health and life quality of all citizens.

  9. PAD TECHNIQUE ON DEFORESTATION SITUATION ON PETROPOLIS’ METROPOLITAN AREA - RJ

    Directory of Open Access Journals (Sweden)

    Amanda Santos de Alencar

    2015-12-01

    Full Text Available With the rising and intensification of production’s activities, as industries, the deforestation taxes show to be on an alarming level. It is wide spread known the consequences that deforestation might cause in metropolitan areas. In order to evalue the consequences of this growing phenomenon, is possible to use a role of ambiental impacts evaluations techniques. One of them is the Preliminary Analysis of Danger (PAD, which is based on qualitative and statistics analysis and might be used in association with other ambiental impacts evaluations techniques. It’s goal is to analyze dangers in potential, it’s causes and consequences, in which is also done an associated risk analysis, which the last is the association between the classifications of frequency and severity, and, in the end, it gives suggestions of measures to avoid these dangers (undesired events. In this study, six dangers have been identified, in which none of them present despicable or low risk (0%, 16% present medium or high risk and 66% present critic risk. These datas point out that the deforestation situation might cause dangers with great consequences to Petropolis’ metropolitan area, just as floodings and earth slidings, which higthlights the urgency of management of the area. DOI: http://dx.doi.org/10.12957/sustinere.2015.20003

  10. Violence against metropolitan bus drivers and fare collectors in Brazil

    Directory of Open Access Journals (Sweden)

    Ada Ávila Assunção

    2015-01-01

    Full Text Available OBJECTIVE To analyze the correlation between sociodemographic factors and working conditions of bus workers in a metropolitan area and violence against them. METHODS This cross-sectional study used a nonprobabilistic sample estimated according to the number of workers employed in bus companies located in three cities in the Belo Horizonte metropolitan region in 2012 (N = 17,470. Face-to-face interviews were conducted using a digital questionnaire. The factors associated with violence were analyzed in two stages using Poisson regression, according to each level. The magnitude of the association was evaluated using prevalence ratios with robust variance and a statistical significance of 5%, and 95% confidence intervals were obtained. RESULTS The study sample comprised 782 drivers and 691 fare collectors; 45.0% participants reported at least one act of violence in the workplace in the last 12 months, with passengers being predominantly responsible. The age of the bus workers was inversely associated with violence. Chronic diseases, sickness absenteeism, and working conditions were also associated with violence. CONCLUSIONS The findings on the correlation between violence and working conditions are essential for implementing prevention strategies by transportation service managers.

  11. Formation of GaAs/AlGaAs and InGaAs/GaAs nanorings by droplet molecular-beam epitaxy

    International Nuclear Information System (INIS)

    Gong, Z.; Niu, Z.C.; Huang, S.S.; Fang, Z.D.; Sun, B.Q.; Xia, J.B.

    2005-01-01

    GaAs/AlGaAs lattice-matched nanorings are formed on GaAs (100) substrates by droplet epitaxy. The crucial step in the formation of nanorings is annealing Ga droplets under As flux for proper time. The observed morphologic evolution of Ga droplets during annealing does not support the hypothesis that As atoms preferentially react with Ga around the periphery of the droplets, but somehow relates to a dewetting process similar to that of unstable films. Photoluminescene (PL) test results confirm the quantum-confinement effect of these GaAs nanorings. Using similar methods, we have fabricated InGaAs/GaAs lattice-mismatched rings

  12. The influence of population on the economic efficiency of the metropolitan governance

    Directory of Open Access Journals (Sweden)

    Yuriy V. Pavlov

    2017-01-01

    Full Text Available Research purpose. In order to implement the optimal metropolitan governance model, it is important to understand the conditions under which this or that model is economically effective. There is a need to develop a quantitatively justified methodology for choosing the optimal metropolitan governance model for different types of metropolitan areas. It has been emphasized in some federal documents of Russia, for example, in the “Recommendations for the selection of pilot projects for approbation and improvement of mechanisms for managing the development of metropolitan areas in the Russian Federation”.Materials and methods. Domestic researchers (N. Zubarevich, K. Gonchar, etc. and foreign researchers (Glaeser Edward L., Nakamura, Ciccone A., Hall R., etc. carried out the study of quantitative relationships between the economic growth of cities and the characteristics of cities.However, for metropolitan areas, the analysis of the relationship has not yet been implemented between the outpacing economic growth of the metropolitan area relative to the average country values (labor productivity and GDP per capita, the institutional factor (the type of metropolitan governance model, andthe non-institutional factor (population size. To identify the dependencies we are interested in, we used the OECD statistical database and OECD researches to identify the metropolitan governance model in the sample of metropolitan areas in the world. The sample in this research was 87 metropolitan areas in Europe and was divided into groups, depending on the population and the introduced metropolitan governance model. For each group, a correlation-regression analysis was performed and a weighted average was calculated from the indexes of the economic growth. As the leading index of the economic growth, labor productivity was used, as the final - GDP per capita. Then a comparison was made between the real value of economic growth in each surveyed metropolitan area and

  13. High breakdown voltage in AlGaN/GaN HEMTs using AlGaN/GaN/AlGaN quantum-well electron-blocking layers.

    Science.gov (United States)

    Lee, Ya-Ju; Yao, Yung-Chi; Huang, Chun-Ying; Lin, Tai-Yuan; Cheng, Li-Lien; Liu, Ching-Yun; Wang, Mei-Tan; Hwang, Jung-Min

    2014-01-01

    In this paper, we numerically study an enhancement of breakdown voltage in AlGaN/GaN high-electron-mobility transistors (HEMTs) by using the AlGaN/GaN/AlGaN quantum-well (QW) electron-blocking layer (EBL) structure. This concept is based on the superior confinement of two-dimensional electron gases (2-DEGs) provided by the QW EBL, resulting in a significant improvement of breakdown voltage and a remarkable suppression of spilling electrons. The electron mobility of 2-DEG is hence enhanced as well. The dependence of thickness and composition of QW EBL on the device breakdown is also evaluated and discussed.

  14. Spatially resolved In and As distributions in InGaAs/GaP and InGaAs/GaAs quantum dot systems

    International Nuclear Information System (INIS)

    Shen, J; Cha, J J; Song, Y; Lee, M L

    2014-01-01

    InGaAs quantum dots (QDs) on GaP are promising for monolithic integration of optoelectronics with Si technology. To understand and improve the optical properties of InGaAs/GaP QD systems, detailed measurements of the QD atomic structure as well as the spatial distributions of each element at high resolution are crucial. This is because the QD band structure, band alignment, and optical properties are determined by the atomic structure and elemental composition. Here, we directly measure the inhomogeneous distributions of In and As in InGaAs QDs grown on GaAs and GaP substrates at the nanoscale using energy dispersive x-ray spectral mapping in a scanning transmission electron microscope. We find that the In distribution is broader on GaP than on GaAs, and as a result, the QDs appear to be In-poor using a GaP matrix. Our findings challenge some of the assumptions made for the concentrations and distributions of In within InGaAs/GaAs or InGaAs/GaP QD systems and provide detailed structural and elemental information to modify the current band structure understanding. In particular, the findings of In deficiency and inhomogeneous distribution in InGaAs/GaP QD systems help to explain photoluminescence spectral differences between InGaAs/GaAs and InGaAs/GaP QD systems. (paper)

  15. Baseline Prevalence of Birth Defects Associated with Congenital Zika Virus Infection - Massachusetts, North Carolina, and Atlanta, Georgia, 2013-2014.

    Science.gov (United States)

    Cragan, Janet D; Mai, Cara T; Petersen, Emily E; Liberman, Rebecca F; Forestieri, Nina E; Stevens, Alissa C; Delaney, Augustina; Dawson, April L; Ellington, Sascha R; Shapiro-Mendoza, Carrie K; Dunn, Julie E; Higgins, Cathleen A; Meyer, Robert E; Williams, Tonya; Polen, Kara N D; Newsome, Kim; Reynolds, Megan; Isenburg, Jennifer; Gilboa, Suzanne M; Meaney-Delman, Dana M; Moore, Cynthia A; Boyle, Coleen A; Honein, Margaret A

    2017-03-03

    Zika virus infection during pregnancy can cause serious brain abnormalities, but the full range of adverse outcomes is unknown (1). To better understand the impact of birth defects resulting from Zika virus infection, the CDC surveillance case definition established in 2016 for birth defects potentially related to Zika virus infection* (2) was retrospectively applied to population-based birth defects surveillance data collected during 2013-2014 in three areas before the introduction of Zika virus (the pre-Zika years) into the World Health Organization's Region of the Americas (Americas) (3). These data, from Massachusetts (2013), North Carolina (2013), and Atlanta, Georgia (2013-2014), included 747 infants and fetuses with one or more of the birth defects meeting the case definition (pre-Zika prevalence = 2.86 per 1,000 live births). Brain abnormalities or microcephaly were the most frequently recorded (1.50 per 1,000), followed by neural tube defects and other early brain malformations † (0.88), eye abnormalities without mention of a brain abnormality (0.31), and other consequences of central nervous system (CNS) dysfunction without mention of brain or eye abnormalities (0.17). During January 15-September 22, 2016, the U.S. Zika Pregnancy Registry (USZPR) reported 26 infants and fetuses with these same defects among 442 completed pregnancies (58.8 per 1,000) born to mothers with laboratory evidence of possible Zika virus infection during pregnancy (2). Although the ascertainment methods differed, this finding was approximately 20 times higher than the proportion of one or more of the same birth defects among pregnancies during the pre-Zika years. These data demonstrate the importance of population-based surveillance for interpreting data about birth defects potentially related to Zika virus infection.

  16. Spatiotemporally resolved air exchange rate as a modifier of acute air pollution-related morbidity in Atlanta.

    Science.gov (United States)

    Sarnat, Jeremy A; Sarnat, Stefanie Ebelt; Flanders, W Dana; Chang, Howard H; Mulholland, James; Baxter, Lisa; Isakov, Vlad; Özkaynak, Halûk

    2013-01-01

    Epidemiological studies frequently use central site concentrations as surrogates of exposure to air pollutants. Variability in air pollutant infiltration due to differential air exchange rates (AERs) is potentially a major factor affecting the relationship between central site concentrations and actual exposure, and may thus influence observed health risk estimates. In this analysis, we examined AER as an effect modifier of associations between several urban air pollutants and corresponding emergency department (ED) visits for asthma and wheeze during a 4-year study period (January 1999-December 2002) for a 186 ZIP code area in metro Atlanta. We found positive associations for the interaction between AER and pollution on asthma ED visits for both carbon monoxide (CO) and nitrogen oxides (NO(x)), indicating significant or near-significant effect modification by AER on the pollutant risk-ratio estimates. In contrast, the interaction term between particulate matter (PM)(2.5) and AER on asthma ED visits was negative and significant. However, alternative distributional tertile analyses showed PM(2.5) and AER epidemiological model results to be similar to those found for NOx and CO (namely, increasing risk ratios (RRs) with increasing AERs when ambient PM(2.5) concentrations were below the highest tertile of their distribution). Despite the fact that ozone (O(3)) was a strong independent predictor of asthma ED visits in our main analysis, we found no O(3)-AER effect modification. To our knowledge, our findings for CO, NOx, and PM(2.5) are the first to provide an indication of short-term (i.e., daily) effect modification of multiple air pollution-related risk associations with daily changes in AER. Although limited to one outcome category in a single large urban locale, the findings suggest that the use of relatively simple and easy-to-derive AER surrogates may reflect intraurban differences in short-term exposures to pollutants of ambient origin.

  17. Investigation of the GaN-on-GaAs interface for vertical power device applications

    International Nuclear Information System (INIS)

    Möreke, Janina; Uren, Michael J.; Kuball, Martin; Novikov, Sergei V.; Foxon, C. Thomas; Hosseini Vajargah, Shahrzad; Wallis, David J.; Humphreys, Colin J.; Haigh, Sarah J.; Al-Khalidi, Abdullah; Wasige, Edward; Thayne, Iain

    2014-01-01

    GaN layers were grown onto (111) GaAs by molecular beam epitaxy. Minimal band offset between the conduction bands for GaN and GaAs materials has been suggested in the literature raising the possibility of using GaN-on-GaAs for vertical power device applications. I-V and C-V measurements of the GaN/GaAs heterostructures however yielded a rectifying junction, even when both sides of the junction were heavily doped with an n-type dopant. Transmission electron microscopy analysis further confirmed the challenge in creating a GaN/GaAs Ohmic interface by showing a large density of dislocations in the GaN layer and suggesting roughening of the GaN/GaAs interface due to etching of the GaAs by the nitrogen plasma, diffusion of nitrogen or melting of Ga into the GaAs substrate.

  18. Investigation of the GaN-on-GaAs interface for vertical power device applications

    Energy Technology Data Exchange (ETDEWEB)

    Möreke, Janina, E-mail: janina.moereke@bristol.ac.uk; Uren, Michael J.; Kuball, Martin [H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Novikov, Sergei V.; Foxon, C. Thomas [Department of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Hosseini Vajargah, Shahrzad; Wallis, David J.; Humphreys, Colin J. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Haigh, Sarah J. [Super STEM Laboratory, STFC Daresbury Campus, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Al-Khalidi, Abdullah; Wasige, Edward; Thayne, Iain [School of Engineering, University of Glasgow, Rankine Bldg, Oakfield Avenue, Glasgow G12 8LT (United Kingdom)

    2014-07-07

    GaN layers were grown onto (111) GaAs by molecular beam epitaxy. Minimal band offset between the conduction bands for GaN and GaAs materials has been suggested in the literature raising the possibility of using GaN-on-GaAs for vertical power device applications. I-V and C-V measurements of the GaN/GaAs heterostructures however yielded a rectifying junction, even when both sides of the junction were heavily doped with an n-type dopant. Transmission electron microscopy analysis further confirmed the challenge in creating a GaN/GaAs Ohmic interface by showing a large density of dislocations in the GaN layer and suggesting roughening of the GaN/GaAs interface due to etching of the GaAs by the nitrogen plasma, diffusion of nitrogen or melting of Ga into the GaAs substrate.

  19. 40 CFR 81.43 - Metropolitan Toledo Interstate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.43 Section 81.43 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.43 Metropolitan Toledo Interstate Air Quality Control Region. The Metropolitan Toledo Interstate Air Quality Control Region (Ohio-Michigan) consists of the territorial area...

  20. 40 CFR 81.31 - Metropolitan Providence Interstate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.31 Section 81.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.31 Metropolitan Providence Interstate Air Quality Control Region. The Metropolitan Providence Interstate Air Quality Control Region (Rhode Island-Massachusetts) consists of the...

  1. 40 CFR 81.78 - Metropolitan Portland Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.78 Section 81.78 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.78 Metropolitan Portland Intrastate Air Quality Control Region. The Metropolitan Portland Intrastate Air Quality Control Region (Maine) consists of the territorial area...

  2. 40 CFR 81.16 - Metropolitan Denver Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.16 Section 81.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.16 Metropolitan Denver Intrastate Air Quality Control Region. The Metropolitan Denver Intrastate Air Quality Control Region (Colorado) consists of the territorial area...

  3. 40 CFR 81.29 - Metropolitan Indianapolis Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Air Quality Control Region. 81.29 Section 81.29 Protection of Environment ENVIRONMENTAL PROTECTION... Designation of Air Quality Control Regions § 81.29 Metropolitan Indianapolis Intrastate Air Quality Control Region. The Metropolitan Indianapolis Intrastate Air Quality Control Region consists of the territorial...

  4. 40 CFR 81.20 - Metropolitan Cincinnati Interstate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.20 Section 81.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.20 Metropolitan Cincinnati Interstate Air Quality Control Region. The Metropolitan Cincinnati Interstate Air Quality Control Region (Ohio-Kentucky-Indiana) is revised to consist of...

  5. 40 CFR 81.101 - Metropolitan Dubuque Interstate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.101 Section 81.101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.101 Metropolitan Dubuque Interstate Air Quality Control Region. The Metropolitan Dubuque Interstate Air Quality Control Region (Illinois-Iowa-Wisconsin) consists of the...

  6. 40 CFR 81.44 - Metropolitan Memphis Interstate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.44 Section 81.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.44 Metropolitan Memphis Interstate Air Quality Control Region. The Metropolitan Memphis Interstate Air Quality Control Region (Arkansas-Mississippi-Tennessee) consists of the...

  7. 40 CFR 81.34 - Metropolitan Dayton Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.34 Section 81.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.34 Metropolitan Dayton Intrastate Air Quality Control Region. The Metropolitan Dayton Intrastate Air Quality Control Region consists of the territorial area encompassed by the...

  8. 40 CFR 81.19 - Metropolitan Boston Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.19 Section 81.19 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.19 Metropolitan Boston Intrastate Air Quality Control Region. The Metropolitan Boston Intrastate Air Quality Control Region (Massachusetts) consists of the territorial area...

  9. 40 CFR 81.28 - Metropolitan Baltimore Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.28 Section 81.28 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.28 Metropolitan Baltimore Intrastate Air Quality Control Region. The Metropolitan Baltimore Intrastate Air Quality Control Region (Maryland) consists of the territorial area...

  10. 40 CFR 81.41 - Metropolitan Birmingham Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.41 Section 81.41 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.41 Metropolitan Birmingham Intrastate Air Quality Control Region. The Metropolitan Birmingham Intrastate Air Quality Control Region (Alabama) has been revised to consist of the...

  11. 40 CFR 81.14 - Metropolitan Chicago Interstate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.14 Section 81.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.14 Metropolitan Chicago Interstate Air Quality Control Region. The Metropolitan Chicago Interstate Air Quality Control Region (Illinois-Indiana) is revised to consist of the...

  12. 40 CFR 81.89 - Metropolitan Cheyenne Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.89 Section 81.89 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.89 Metropolitan Cheyenne Intrastate Air Quality Control Region. The Metropolitan Cheyenne Intrastate Air Quality Control Region (Wyoming) consists of the territorial area...

  13. 40 CFR 81.87 - Metropolitan Boise Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.87 Section 81.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.87 Metropolitan Boise Intrastate Air Quality Control Region. The Metropolitan Boise Intrastate Air Quality Control Region (Idaho) consists of the territorial area encompassed...

  14. 40 CFR 81.75 - Metropolitan Charlotte Interstate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.75 Section 81.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.75 Metropolitan Charlotte Interstate Air Quality Control Region. The Metropolitan Charlotte Interstate Air Quality Control Region (North Carolina-South Carolina) has been revised...

  15. Deprivation and mortality in non-metropolitan areas of England and Wales.

    Science.gov (United States)

    Jessop, E G

    1996-10-01

    To test the hypothesis that the relationship between deprivation and mortality is weaker among residents of non-metropolitan areas of England and Wales than among residents of metropolitan areas. This study compared mortality, expressed as standardised mortality ratios (SMRs), in residents of metropolitan and non-metropolitan districts at three levels of deprivation classified by an electoral ward deprivation score and by home and car ownership. SMRs were computed for all causes of death, for bronchitis and asthma (ICD9 codes 490-493), and for accident, violence, and poisoning (ICD9 codes 800-999). England and Wales. Members of the longitudinal study of the Office of Population Censuses and Surveys, a quasi-random 1% sample of the population of England and Wales. There was an association between deprivation and mortality which was clear for all cause mortality, more noticeable for respiratory disease, and less clear for deaths from accident, violence, and poison. In general, the results showed a remarkable similarity between metropolitan and non-metropolitan areas. This study does not support the hypothesis that the relationship between mortality and deprivation differs between residents of metropolitan and non-metropolitan areas of England and Wales.

  16. Metropolization Process for enhancing local and regional planning : an experience of cirebon metropolitan, West Java

    Science.gov (United States)

    Supriyadi Rustidja, E.

    2018-03-01

    Metropolitan develops in line with resource utilization, investment, and transactions of regional activities. Metropolization of an area gives emerge urban economy that changes the situation, form, and pattern of urban space interactions. On the other hand, metropolism concerns the strategy of changing variation of urban space, so that metropolitan invasion not only form of urban space but also the process of interaction among stakeholders in developing metropolitan area. Based on participatory research, this article explores metropolitan invasion process for enhancing local and regional planning, both indigenous and intrusive cataclysmic. The study find that the primeval, rural, and urban as elemental environment must be considered in developing metropolitan, not merely form the structure and pattern of urban space. The metropolization process also requires the strategic of rural urban linkage, context setting and local assessment, strategic community investment, and interculturalist approach. The other findings of the study show that metropolization in Cirebon Metropolitan, West Java emphasizing on promotion of competitiveness strategy, value chain urban activities, and networking of urban areas. Cirebon Metropolitan must promote the realization of growth centers and connect the interregional activities of metropolitan area for providing sustainable economic growth.

  17. 78 FR 10589 - Revision of Air Quality Implementation Plan; California; Sacramento Metropolitan Air Quality...

    Science.gov (United States)

    2013-02-14

    ... Quality Implementation Plan; California; Sacramento Metropolitan Air Quality Management District... Sacramento Metropolitan Air Quality Management District (SMAQMD or District) portion of the California State... sources within the areas covered by the plan as necessary to assure that the National Ambient Air Quality...

  18. Spatio-temporal aspects of gated residential security estates in non-metropolitan Western Cape

    CSIR Research Space (South Africa)

    Spocter, M

    2011-04-01

    Full Text Available . This research attempts to address this research gap by focusing on the spatio-temporal aspects of non-metropolitan gated residential security estates in the Western Cape Province. It was found that most non-metropolitan gated residential security estates were...

  19. Urban food security at the crossroads between metropolitan food planning and global trade

    NARCIS (Netherlands)

    Wascher, Dirk Michael; Jeurissen, Leonne

    2017-01-01

    Making use of Life Cycle Thinking, the Metropolitan Foodscape Planner (MFP) tool provides ecological footprint maps and supply/demand data showing a large potential for metropolitan food supplies. In the discussion, we examine these results in the light of recent research on the impacts of the

  20. Polycentric Structures in Latin American Metropolitan Areas : Identifying Employment Sub-centres

    NARCIS (Netherlands)

    Fernández-Maldonado, Ana María; Romein, Arie; Verkoren, Otto|info:eu-repo/dai/nl/073181773; Parente Paula Pessoa, Renata

    2014-01-01

    Fernández-Maldonado A. M., Romein A., Verkoren O. and Parente Paula Pessoa R. Polycentric structures in Latin American metropolitan areas: identifying employment sub-centres, Regional Studies. The significant spatial transformations that have occurred within Latin American metropolitan areas since

  1. Knowledge Worker Perceptions of Telework Policy in the New York Metropolitan Area: A Qualitative Descriptive Study

    Science.gov (United States)

    Slaughter, Sandra Lorraine Hawks

    2013-01-01

    This qualitative descriptive case study, "Knowledge Worker Perceptions of Telework in the New York Metropolitan Area," was conducted to explore the perceptions of knowledge workers who commute to a physical workplace in the New York Metropolitan area (NYMA). In-depth interviews were conducted with fourteen NYMA commuters who are…

  2. 23 CFR 420.109 - What are the requirements for distribution of metropolitan planning funds?

    Science.gov (United States)

    2010-04-01

    ... and Research Funds § 420.109 What are the requirements for distribution of metropolitan planning funds... 23 Highways 1 2010-04-01 2010-04-01 false What are the requirements for distribution of metropolitan planning funds? 420.109 Section 420.109 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF...

  3. Non-metropolitan residential gated developments in the Western Cape Province, South Africa

    CSIR Research Space (South Africa)

    Spocter, M

    2011-07-01

    Full Text Available -metropolitan locale and the topic is also unexplored in the South African context. This research attempts to address this research gap by investigating the locations of gated developments in non-metropolitan towns of varying sizes in the Western Cape...

  4. Shot noise reduction in the AlGaAs/GaAs- and InGaP/GaAs-based HBTs

    Science.gov (United States)

    Sakalas, Paulius; Schroeter, Michael; Zampardi, Peter; Zirath, Herbert

    2003-05-01

    Noise parameters of AlGaAs/GaAs and InGaP/GaAs HBTs were measured in microwave frequency range and modeled using the small-signal equivalent circuit approach. Correlated current noise sources in the base and collector currents with thermal noise in the circuit resistive elements were accounted for by the model and yielded good agreement with the measured data. This enabled an extraction of the different noise source contributions to minimum noise figure (NFmin) in AlGaAs/GaAs and InGaP/GaAs HBTs. Decomposition of the (NFmin) in to the different contributors showed that the main noise sources in investigated HBTs are correlated base and collector current shot noise. The observed minimum of NFmin versus frequency at lower collector current is explained by the reduction of the emitter/base junction shot noise component due to the spike in the emitter/base junction and associated accumulation of the quasi-thermalized electrons forming a space charge, which screens the electron transfer through the barrier. The bias (VCE) increase creates an efficient electric field in collector/base junction, capable of 'washing out' the accumulated charge. Such shot noise reduction in HBTs could be exploited in the LNA for the RF application.

  5. Smart City, Metropolitan Areas and Competitiveness: the Case Study of Florence

    Directory of Open Access Journals (Sweden)

    Carmela Gargiulo

    2015-07-01

    Full Text Available In several urban contexts, the definition of a new development process is arising and it is focused on the use and the application of new technologies in different areas of the urban system. Such new development process is aimed at increasing life quality and local communities wellness and at promoting the creation of a more efficient and more sustainable urban system, as well as at making it more competitive. The issue of the reorganization of metropolitan areas is combined with such process, following the recent approval of the Delrio Law that establishes the Metropolitan City in Italy, as government authority of the metropolitan areas. Smart City, Metropolitan Areas and Competitiveness are the three topics of this paper, which aim is the description of the most innovative politics and initiatives adopted in the Metropolitan City of Florence that is proposed as a case study where such topics are combined.

  6. Electrical compensation by Ga vacancies in Ga2O3

    OpenAIRE

    Korhonen, Esa; Tuomisto, F.; Gogova, D.; Wagner, G.; Baldini, M.; Galazka, Z.; Schewski, R.; Albrecht, M.

    2015-01-01

    The authors have applied positron annihilation spectroscopy to study the vacancy defects in undoped and Si-doped Ga2O3 thin films. The results show that Ga vacancies are formed efficiently during metal-organic vapor phase epitaxy growth of Ga2O3 thin films. Their concentrations are high enough to fully account for the electrical compensation of Si doping. This is in clear contrast to another n-type transparent semiconducting oxide In2O3, where recent results show that n-type conductivity is n...

  7. On the effect of N-GaN/P-GaN/N-GaN/P-GaN/N-GaN built-in junctions in the n-GaN layer for InGaN/GaN light-emitting diodes.

    Science.gov (United States)

    Kyaw, Zabu; Zhang, Zi-Hui; Liu, Wei; Tan, Swee Tiam; Ju, Zhen Gang; Zhang, Xue Liang; Ji, Yun; Hasanov, Namig; Zhu, Binbin; Lu, Shunpeng; Zhang, Yiping; Sun, Xiao Wei; Demir, Hilmi Volkan

    2014-01-13

    N-GaN/P-GaN/N-GaN/P-GaN/N-GaN (NPNPN-GaN) junctions embedded between the n-GaN region and multiple quantum wells (MQWs) are systematically studied both experimentally and theoretically to increase the performance of InGaN/GaN light emitting diodes (LEDs) in this work. In the proposed architecture, each thin P-GaN layer sandwiched in the NPNPN-GaN structure is completely depleted due to the built-in electric field in the NPNPN-GaN junctions, and the ionized acceptors in these P-GaN layers serve as the energy barriers for electrons from the n-GaN region, resulting in a reduced electron over flow and enhanced the current spreading horizontally in the n- GaN region. These lead to increased optical output power and external quantum efficiency (EQE) from the proposed device.

  8. Injuries to Aboriginal populations living on- and off-reserve in metropolitan and non-metropolitan areas in British Columbia, Canada: Incidence and trends, 1986-2010

    Directory of Open Access Journals (Sweden)

    Mariana Brussoni

    2016-05-01

    Full Text Available Abstract Background Disparities in injury rates between Aboriginal and non-Aboriginal populations in British Columbia (BC are well established. Information regarding the influence of residence on disparities is scarce. We sought to fill these gaps by examining hospitalization rates for all injuries, unintentional injuries and intentional injuries across 24 years among i Aboriginal and total populations; ii populations living in metropolitan and non-metropolitan areas; and iii Aboriginal populations living on- and off-reserve. Methods We used data spanning 1986 through 2010 from BC’s universal health care insurance plan, linked to vital statistics databases. Aboriginal people were identified by insurance premium group and birth and death record notations, and their residence was determined by postal code. “On-reserve” residence was established by postal code areas associated with an Indian reserve or settlement. Health Service Delivery Areas (HSDAs were classified as “metropolitan” if they contained a population of at least 100,000 with a density of 400 or more people per square kilometre. We calculated the crude hospitalization incidence rate and the Standardized Relative Risk (SRR of hospitalization due to injury standardizing by gender, 5-year age group, and HSDA. We assessed cumulative change in SRR over time as the relative change between the first and last years of the observation period. Results Aboriginal metropolitan populations living off-reserve had the lowest SRR of injury (2.0, but this was 2.3 times greater than the general British Columbia metropolitan population (0.86. For intentional injuries, Aboriginal populations living on-reserve in non-metropolitan areas were at 5.9 times greater risk than the total BC population. In general, the largest injury disparities were evident for Aboriginal non-metropolitan populations living on-reserve (SRR 3.0; 2.5 times greater than the general BC non-metropolitan population (1

  9. Growth of GaN layers using Ga2O vapor obtained from Ga and H2O vapor

    International Nuclear Information System (INIS)

    Sumi, Tomoaki; Taniyama, Yuuki; Takatsu, Hiroaki; Juta, Masami; Kitamoto, Akira; Imade, Mamoru; Yoshimura, Masashi; Mori, Yusuke; Isemura, Masashi

    2015-01-01

    In this study, we performed growth of GaN layers using Ga 2 O vapor synthesized from Ga and H 2 O vapor. In this process, we employed H 2 O vapor instead of HCl gas in hydride vapor phase epitaxy (HVPE) to synthesize Ga source gas. In the synthesis reaction of Ga 2 O, a Ga 2 O 3 whisker formed and covered Ga, which impeded the synthesis reaction of Ga 2 O. The formation of the Ga 2 O 3 whisker was suppressed in H 2 ambient at high temperatures. Then, we adopted this process to supply a group III precursor and obtained an epitaxial layer. X-ray diffraction (XRD) measurement revealed that the epitaxial layer was single-crystalline GaN. Growth rate increased linearly with Ga 2 O partial pressure and reached 104 µm/h. (author)

  10. Effect of GaN buffer polarization on electron distribution of AlGaN/GaN heterostructure

    International Nuclear Information System (INIS)

    He, Xiaoguang; Zhao, Degang; Liu, Wei; Yang, Jing; Li, Xiaojing; Li, Xiang

    2016-01-01

    The formation of 2DEG in AlGaN/GaN heterostructure is discussed in detail. A misunderstanding about the 2DEG sheet density expression is clarified. It is predicted by theoretical analysis and validated by self-consistent Schrodinger–Poisson numerical simulation that under the force of GaN polarization, large amounts of electrons will accumulate at the GaN/substrate interface in AlGaN/GaN/substrate HEMT structure. - Highlights: • The formation of 2DEG in AlGaN/GaN heterostructure is discussed in detail. • Self-consistent Schrodinger–Poisson numerical simulation is used to modulate the AlGaN/GaN/substrate structure. • It is predicted by that large amounts of electrons will accumulate at the GaN/substrate interface.

  11. Effect of GaN buffer polarization on electron distribution of AlGaN/GaN heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    He, Xiaoguang; Zhao, Degang, E-mail: dgzhao@red.semi.ac.cn; Liu, Wei; Yang, Jing; Li, Xiaojing; Li, Xiang

    2016-06-15

    The formation of 2DEG in AlGaN/GaN heterostructure is discussed in detail. A misunderstanding about the 2DEG sheet density expression is clarified. It is predicted by theoretical analysis and validated by self-consistent Schrodinger–Poisson numerical simulation that under the force of GaN polarization, large amounts of electrons will accumulate at the GaN/substrate interface in AlGaN/GaN/substrate HEMT structure. - Highlights: • The formation of 2DEG in AlGaN/GaN heterostructure is discussed in detail. • Self-consistent Schrodinger–Poisson numerical simulation is used to modulate the AlGaN/GaN/substrate structure. • It is predicted by that large amounts of electrons will accumulate at the GaN/substrate interface.

  12. Assessment of Ga2O3 technology

    Science.gov (United States)

    2016-09-15

    this article has given the emerging technology of GaN a valuable push in term of encouragement to stay with it while the painful technology development...Ga2O3 α-Ga2O3 β-Ga2O3 β-Ga2O3 β-Ga2O3 poly - Ga2O3 β-Ga2O3 Epi-layer Growth Method MBE (ozone) MBE (ozone) MBE (ozone) Mist-CVD MBE (ozone... pains to treat the wafer surface with BCl3 RIE to create charges at the interface. The gate contact was also barely a Schottky contact evidenced by

  13. Causes of informal settlements in Ekurhuleni Metropolitan Municipality: An exploration

    Directory of Open Access Journals (Sweden)

    Noah K. Marutlulle

    2017-08-01

    Full Text Available This article aims to explore the causes of informal settlements in Ekurhuleni Metropolitan Municipality (EMM. The article strongly challenges the view that the cause of informal settlements in EMM and other parts of South Africa is predominantly the apartheid government and agrees with literature which provides evidence that to a larger extent, the present government, not the apartheid government, is one of the dominant causes of informal settlements. The article further establishes a common and fertile ground for the convergence of the different views and perspectives into variables which, in addition to the present government, include population growth, government economic policies, economic variables, housing shortage, unavailability of land and unaffordability as the real causes of informal settlements in EMM.

  14. Massage Therapy in Outpatient Cancer Care: A Metropolitan Area Analysis

    Science.gov (United States)

    Miccio, Robin Streit; Parikh, Bijal

    2017-01-01

    Massage offers cancer patients general quality of life benefits as well as alleviation of cancer-related symptoms/cancer-treatment–related symptoms including pain, anxiety, and fatigue. Little is known about whether massage is accessible to cancer patients who receive treatment in the outpatient setting and how massage is incorporated into the overall cancer treatment plan. Outpatient cancer centers (n = 78) in a single metropolitan area were included this mixed-methods project that included a systematic analysis of website information and a telephone survey. Massage was offered at only 40 centers (51.3% of total). A range of massage modalities were represented, with energy-based therapies (Reiki and Therapeutic Touch) most frequently provided. Although massage therapists are licensed health care providers in the states included in this analysis, massage was also provided by nurses, physical therapists, and other health care professionals. PMID:28845677

  15. Skinner boxes for psychotics: operant conditioning at Metropolitan State Hospital.

    Science.gov (United States)

    Rutherford, Alexandra

    2003-01-01

    Between 1953 and 1965, Ogden Lindsley and his associates conducted free-operant research with psychiatric inpatients and normal volunteers at Metropolitan State Hospital in Waltham, Massachusetts. Their project, originally named "Studies in Behavior Therapy," was renamed "Harvard Medical School Behavior Research Laboratory" in 1955. This name change and its implications were significant. The role of the laboratory in the history of the relationship between the experimental analysis of behavior and applied behavior analysis is discussed. A case is made for viewing Lindsley's early work as foundational for the subfield of the experimental analysis of human behavior that formally coalesced in the early 1980s. The laboratory's work is also contextualized with reference to the psychopharmacological revolution of the 1950s. Finally, a four-stage framework for studying the historical and conceptual development of behavior analysis is proposed.

  16. Urban mobility regulation in metropolitan area of Mendoza

    Directory of Open Access Journals (Sweden)

    Lía Martínez

    2016-11-01

    Full Text Available Achieving the paradigm of sustainable urban mobility requires institutional capacities, appropriate policies and a regulatory framework that contains them. This work aims to contribute to the knowledge of the regulation of urban mobility in the metropolitan area of Mendoza. To this end, the current mobility regulations are assessed through indicators that are classified into three key areas: institutional and political organization, urban system and financial setup. The purpose is to account for the existence, or not, of regulatory capacities contained in the paradigm of sustainable mobility. Among the results, the absence of a policy of sustainable urban mobility is noteworthy, as well as the lack of sectorial coordination. Also of note is the absence of coordination between the urban planning system and the public transport provision. Lastly, in the financial sector, the results point to a promotion of sustainable transport modes but without such an explicit purpose.

  17. Atmospheric aerosol layers over Bangkok Metropolitan Region from CALIPSO observations

    Science.gov (United States)

    Bridhikitti, Arika

    2013-06-01

    Previous studies suggested that aerosol optical depth (AOD) from the Earth Observing System satellite retrievals could be used for inference of ground-level air quality in various locations. This application may be appropriate if pollution in elevated atmospheric layers is insignificant. This study investigated the significance of elevated air pollution layers over the Bangkok Metropolitan Region (BMR) from all available aerosol layer scenes taken from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) for years 2007 to 2011. The results show that biomass burning smoke layers alone were the most frequently observed. The smoke layers accounted for high AOD variations and increased AOD levels. In the dry seasons, the smoke layers alone with high AOD levels were likely brought to the BMR via northeasterly to easterly prevailing winds and found at altitudes above the typical BMR mixing heights of approximately 0.7 to 1.5 km. The smoke should be attributed to biomass burning emissions outside the BMR.

  18. Comparative Risk Analysis for Metropolitan Solid Waste Management Systems

    Science.gov (United States)

    Chang, Ni-Bin; Wang, S. F.

    1996-01-01

    Conventional solid waste management planning usually focuses on economic optimization, in which the related environmental impacts or risks are rarely considered. The purpose of this paper is to illustrate the methodology of how optimization concepts and techniques can be applied to structure and solve risk management problems such that the impacts of air pollution, leachate, traffic congestion, and noise increments can be regulated in the iong-term planning of metropolitan solid waste management systems. Management alternatives are sequentially evaluated by adding several environmental risk control constraints stepwise in an attempt to improve the management strategies and reduce the risk impacts in the long run. Statistics associated with those risk control mechanisms are presented as well. Siting, routing, and financial decision making in such solid waste management systems can also be achieved with respect to various resource limitations and disposal requirements.

  19. Quantum metropolitan optical network based on wavelength division multiplexing.

    Science.gov (United States)

    Ciurana, A; Martínez-Mateo, J; Peev, M; Poppe, A; Walenta, N; Zbinden, H; Martín, V

    2014-01-27

    Quantum Key Distribution (QKD) is maturing quickly. However, the current approaches to its application in optical networks make it an expensive technology. QKD networks deployed to date are designed as a collection of point-to-point, dedicated QKD links where non-neighboring nodes communicate using the trusted repeater paradigm. We propose a novel optical network model in which QKD systems share the communication infrastructure by wavelength multiplexing their quantum and classical signals. The routing is done using optical components within a metropolitan area which allows for a dynamically any-to-any communication scheme. Moreover, it resembles a commercial telecom network, takes advantage of existing infrastructure and utilizes commercial components, allowing for an easy, cost-effective and reliable deployment.

  20. Massage Therapy in Outpatient Cancer Care: A Metropolitan Area Analysis.

    Science.gov (United States)

    Cowen, Virginia S; Miccio, Robin Streit; Parikh, Bijal

    2017-10-01

    Massage offers cancer patients general quality of life benefits as well as alleviation of cancer-related symptoms/cancer-treatment-related symptoms including pain, anxiety, and fatigue. Little is known about whether massage is accessible to cancer patients who receive treatment in the outpatient setting and how massage is incorporated into the overall cancer treatment plan. Outpatient cancer centers (n = 78) in a single metropolitan area were included this mixed-methods project that included a systematic analysis of website information and a telephone survey. Massage was offered at only 40 centers (51.3% of total). A range of massage modalities were represented, with energy-based therapies (Reiki and Therapeutic Touch) most frequently provided. Although massage therapists are licensed health care providers in the states included in this analysis, massage was also provided by nurses, physical therapists, and other health care professionals.

  1. Land suitability for waste disposal in metropolitan areas.

    Science.gov (United States)

    Baiocchi, Valerio; Lelo, Keti; Polettini, Alessandra; Pomi, Raffaella

    2014-08-01

    Site selection for waste disposal is a complex task that should meet the requirements of communities and stakeholders. In this article, three decision support methods (Boolean logic, index overlay and fuzzy gamma) are used to perform land suitability analysis for landfill siting. The study was carried out in one of the biggest metropolitan regions of Italy, with the objective of locating suitable areas for waste disposal. Physical and socio-economic information criteria for site selection were decided by a multidisciplinary group of experts, according to state-of-the-art guidelines, national legislation and local normative on waste management. The geographic information systems (GIS) based models used in this study are easy to apply but require adequate selection of criteria and weights and a careful evaluation of the results. The methodology is arranged in three steps, reflecting the criteria defined by national legislation on waste management: definition of factors that exclude location of landfills or waste treatment plants; classification of the remaining areas in terms of suitability for landfilling; and evaluation of suitable sites in relation to preferential siting factors (such as the presence of quarries or dismissed plants). The results showed that more than 80% of the provincial territory falls within constraint areas and the remaining territory is suitable for waste disposal for 0.72% or 1.93%, according to the model. The larger and most suitable sites are located in peripheral areas of the metropolitan system. The proposed approach represents a low-cost and expeditious alternative to support the spatial decision-making process. © The Author(s) 2014.

  2. Seismic Microzonation of Islamabad-Rawalpindi Metropolitan Area, Pakistan

    Science.gov (United States)

    Khan, Sarfraz; Khan, M. Asif

    2018-01-01

    Microzonation deals with classifying seismic hazards in terms of ground motions resulting from amplification of seismic waves by nature of soil profiles underlying a site, town or city. This paper presents the results of microzonation study for Islamabad metropolitan, the capital of Pakistan. Cumulative SPT- N values from geophysical borehole and microtremor (Tromino Engy Plus) data were used to classify the soils into classes C (very dense soil profile and soft rock) and D (stiff soil profile) as devised by the National Earthquake Hazard Reduction Program (NEHRP). Soil response analyses were carried out based on scaled time histories of Kashmir earthquake (2005, 0.02 g), Mangla earthquake (2006, 0.031 g) and Haripur earthquake (2010, 0.13 g) corresponding to return periods of 150, 475, 975 and 2475 years. Spectral accelerations on the ground surface are calculated by two different approaches (1) soil response analysis performed using one dimensional shear wave propagation method (equivalent linear approach); and (2) NEHRP and Borcherdt amplification factors. Microzonation maps are produced with respect to ground shaking intensity for the return periods of 150, 475, 975 and 2475 years taking into account the variation of the spectral accelerations calculated based on these two procedures. The results show that the accelerations at the ground surface in the Islamabad-Rawalpindi metropolitan are in the range of 0.40-0.48 g (for 150 years), 0.59-0.65 g (for 475 years), 0.71-0.77 g (for 975 years), and 0.92-0.94 g (for 2475 years). The amplification factors for these four hazard levels range from 0.96 to 1.38 (150 years), 0.90-1.14 (475 years), 0.85-1.04 (975 years) and 0.84-1.00 (2475 years).

  3. Antisites and anisotropic diffusion in GaAs and GaSb

    KAUST Repository

    Tahini, H. A.

    2013-10-02

    The significant diffusion of Ga under Ga-rich conditions in GaAs and GaSb is counter intuitive as the concentration of Ga vacancies should be depressed although Ga vacancies are necessary to interpret the experimental evidence for Ga transport. To reconcile the existence of Ga vacancies under Ga-rich conditions, transformation reactions have been proposed. Here, density functional theory is employed to calculate the formation energies of vacancies on both sublattices and the migration energy barriers to overcome the formation of the vacancy-antisite defect. Transformation reactions enhance the vacancy concentration in both materials and migration energy barriers indicate that Ga vacancies will dominate.

  4. GA microwave window development

    International Nuclear Information System (INIS)

    Moeller, C.P.; Kasugai, A.; Sakamoto, K.; Takahashi, K.

    1994-10-01

    The GA prototype distributed window was tested in a 32 mm diam. waveguide system at a power density suitable for a MW gyrotron, using the JAERI/Toshiba 110 GHz long pulse internal converter gyrotron in the JAERI test stand. The presence of the untilted distributed window had no adverse effect on the gyrotron operation. A pulse length of 10 times the calculated thermal equilibrium time (1/e time) of 30 msec was reached, and the window passed at least 750 pulses greater than 30 msec and 343 pulses greater than 60 msec. Beyond 100 msec, the window calorimetry reached steady state, allowing the window dissipation to be measured in a single pulse. The measured loss of 4.0% agrees both with the estimated loss, on which the stress calculations are based, and with the attenuation measured at low power in the HE 11 mode. After the end of the tests, the window was examined; no evidence of arcing air coating was found in the part of the window directly illuminated by the microwaves, although there was discoloration in a recess containing an optical diagnostic which outgassed, causing a local discharge to occur in that recess. Finally, there was no failure of the metal-sapphire joints during a total operating time of 50 seconds consisting of pulses longer than 30 msec

  5. Solar heating and cooling experiment for a school in Atlanta: performance report. [George A. Towns Elementary School

    Energy Technology Data Exchange (ETDEWEB)

    1977-08-01

    This report documents the performance, and conclusions therefrom, of a 13 month period of monitoring the performance of the experimental solar heating and cooling system installed in the George A. Towns Elementary School, Atlanta, Georgia. The solar collector system involves 10,360 ft/sup 2/ of PPG ''Baseline'' flat-plate collectors with an ALCOA selective coating, augmented by 10,800 square feet of aluminized Mylar reflectors. Three 15,000 gallon steel storage tanks, a 100-ton Arkla absorption chiller together with its cooling tower, a collector gravity drain system with a 1,600 gallon holding tank and a collector nitrogen purge system, six pumps and 26 pneumatic control valves were installed and interfaced with the pre-existing gas furnace and distribution system. In the winter heating mode, the solar energy is stored in all three tanks, total capacity of 45,000 gallons, between design temperatures of 105/sup 0/ to 140/sup 0/F. As soon as Tank 1 is brought up to 140/sup 0/F, the control valves isolate it from the collector loop, and the hot water from the collectors is used to charge Tanks 2 and then Tank 3. Water can be drawn from Tank 1 to heat the school while Tanks 2 and 3 are being charged. As a consequence of the flexibility provided by the three tanks, compared to a single tank of equivalent capacity, the thermal lag in the system is reduced. A variable speed pump, in response to sensors at the inlet and outlet of the collectors, modulates the flow of water through each collector from a maximum of .5 gpm to a minimum of .1 gpm, attempting to maintain a temperature rise of about 10/sup 0/F. In the summer cooling mode, storage tanks 2 and 3 are designed to store hot water at temperatures between 180/sup 0/ to 200/sup 0/F, and tank 1 is used to store chilled water. (WHK)

  6. Usage of Social Media in City Marketing: A Research on 30 Metropolitan Municipalities in Turkey

    Directory of Open Access Journals (Sweden)

    Niyazi Gümüş

    2017-01-01

    Full Text Available Rapid changes in information and communication technologies cause serious developments in marketing field similar to every sector. In parallel with these developments, the social media channels which appear as Web 2.0 applications have a number of advantages in comparison with traditional media channels. Social media gained a place in marketing activities because of its advantages. Social media is added on instruments in line with these developments that countries benefit in marketing activities for attracting more tourists, investment and becoming prominent against the other cities. Cities intensively benefit from social media because of social media’s properties like reaching the large masses, low marketing cost, interaction, receiving feedbacks rapidly, etc. Within this context, the purpose of this research is to determine the use statuses of social media by metropolitan municipalities as part of city marketing. In accordance with this purpose, official social media accounts of 30 metropolitan municipalities are investigated between the dates of 01/09/2016 and 30/09/2016, then their shares in social media channels are investigated in the context of city marketing.It is observed that two metropolitan municipalities do not have official Facebook accounts, four metropolitan municipalities do not have an official Twitter account as well. Again, it is found that 19 metropolitan municipalities do not have an official Instagram account and 17 metropolitan municipalities do not have official YouTube account. In consequence, it is observed that, our metropolitan municipalities do not benefit from social media effectively for city marketing activities.

  7. /sup 67/Ga lung scan

    Energy Technology Data Exchange (ETDEWEB)

    Niden, A.H.; Mishkin, F.S.; Khurana, M.M.L.; Pick, R.

    1977-03-21

    Twenty-three patients with clinical signs of pulmonary embolic disease and lung infiltrates were studied to determine the value of gallium citrate /sup 67/Ga lung scan in differentiating embolic from inflammatory lung disease. In 11 patients without angiographically proved embolism, only seven had corresponding ventilation-perfusion defects compatible with inflammatory disease. In seven of these 11 patients, the /sup 67/Ga concentration indicated inflammatory disease. In the 12 patients with angiographically proved embolic disease, six had corresponding ventilation-perfusion defects compatible with inflammatory disease. None had an accumulation of /sup 67/Ga in the area of pulmonary infiltrate. Thus, ventilation-perfusion lung scans are of limited value when lung infiltrates are present. In contrast, the accumulation of /sup 67/Ga in the lung indicates an inflammatory process. Gallium imaging can help select those patients with lung infiltrates who need angiography.

  8. Flood-inundation maps for Peachtree Creek from the Norfolk Southern Railway bridge to the Moores Mill Road NW bridge, Atlanta, Georgia

    Science.gov (United States)

    Musser, Jonathan W.

    2012-01-01

    Digital flood-inundation maps for a 5.5-mile reach of the Peachtree Creek from the Norfolk Southern Railway bridge to the Moores Mill Road NW bridge, were developed by the U.S. Geological Survey (USGS) in cooperation with the City of Atlanta, Georgia. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage at Peachtree Creek at Atlanta, Georgia (02336300) and the USGS streamgage at Chattahoochee River at Georgia 280, near Atlanta, Georgia (02336490). Current water level (stage) at these USGS streamgages may be obtained at http://waterdata.usgs.gov/ and can be used in conjunction with these maps to estimate near real-time areas of inundation. The National Weather Service (NWS) is incorporating results from this study into the Advanced Hydrologic Prediction Service (AHPS) flood warning system (http:/water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that commonly are collocated at USGS streamgages. The forecasted peak-stage information for the USGS streamgage at Peachtree Creek, which is available through the AHPS Web site, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. A one-dimensional step-backwater model was developed using the U.S. Army Corps of Engineers HEC–RAS software for a 6.5-mile reach of Peachtree Creek and was used to compute flood profiles for a 5.5-mile reach of the creek. The model was calibrated using the most current stage-discharge relations at the Peachtree Creek at Atlanta, Georgia, streamgage (02336300), and the Chattahoochee River at Georgia 280, near Atlanta, Georgia, streamgage (02336490) as well as high water marks collected during the 2010 annual peak flow event. The hydraulic model was then used to determine 50 water

  9. Education for Earthquake Disaster Prevention in the Tokyo Metropolitan Area

    Science.gov (United States)

    Oki, S.; Tsuji, H.; Koketsu, K.; Yazaki, Y.

    2008-12-01

    Japan frequently suffers from all types of disasters such as earthquakes, typhoons, floods, volcanic eruptions, and landslides. In the first half of this year, we already had three big earthquakes and heavy rainfall, which killed more than 30 people. This is not just for Japan but Asia is the most disaster-afflicted region in the world, accounting for about 90% of all those affected by disasters, and more than 50% of the total fatalities and economic losses. One of the most essential ways to reduce the damage of natural disasters is to educate the general public to let them understand what is going on during those desasters. This leads individual to make the sound decision on what to do to prevent or reduce the damage. The Ministry of Education, Culture, Sports, Science and Technology (MEXT), therefore, offered for public subscription to choose several model areas to adopt scientific education to the local elementary schools, and ERI, the Earthquake Research Institute, is qualified to develop education for earthquake disaster prevention in the Tokyo metropolitan area. The tectonic setting of this area is very complicated; there are the Pacific and Philippine Sea plates subducting beneath the North America and the Eurasia plates. The subduction of the Philippine Sea plate causes mega-thrust earthquakes such as the 1703 Genroku earthquake (M 8.0) and the 1923 Kanto earthquake (M 7.9) which had 105,000 fatalities. A magnitude 7 or greater earthquake beneath this area is recently evaluated to occur with a probability of 70 % in 30 years. This is of immediate concern for the devastating loss of life and property because the Tokyo urban region now has a population of 42 million and is the center of approximately 40 % of the nation's activities, which may cause great global economic repercussion. To better understand earthquakes in this region, "Special Project for Earthquake Disaster Mitigation in Tokyo Metropolitan Area" has been conducted mainly by ERI. It is a 4-year

  10. Radon and lung cancer in Bangalore Metropolitan, India

    International Nuclear Information System (INIS)

    Sathish, L.A.; Nethravathi, K.S.; Ramachandran, T.V.

    2012-01-01

    Radon is a radioactive gas released from the normal decay of 238 U in rocks and soil. It is an invisible, odorless, tasteless gas that seeps up through the ground and diffuses into the air. In a few areas, depending on local geology, radon dissolves into ground water and can be released into the air when the water is used. Radon gas usually exists at very low levels outdoors. However, in areas without adequate ventilation, such as underground mines, radon can accumulate to levels that substantially increase the risk of lung cancer. Radon decays quickly, giving off tiny radioactive particles. When inhaled, these radioactive particles can damage the cells that line the lung. Long-term exposure to radon can lead to lung cancer, the only cancer proven to be associated with inhaling radon. Public interest in radon has been occasionally piqued by articles in the general press. Considerable attention has been given to the high radon levels that were uncovered in the Reading Prong region of Pennsylvania, following the discovery in late 1984 of extremely high levels in one home. Several epidemiological study programmes in different countries are in progress to estimate the population exposures due to natural radiation with a view to obtain the radiation risk coefficients at low dose rate levels. In this regard, radiation surveys in high background areas (HBRAs) can provide excellent settings for epidemiological studies relating to the effects of low doses of radiation. In view of these, a comprehensive estimate of the natural inhalation dose requires both 222 Rn and 220 Rn levels in the indoor atmosphere. In this outlook an attempt is made to investigate the 222 Rn and 220 Rn levels in dwellings of Bangalore Metropolitan, India. Three year results shows that the activity concentrations of 226 Ra, 232 Th, radon in ground water, the concentrations 222 Rn and 220 Rn and the dose rate (mSvy -1 ) are at alarming levels for the environment of Bangalore Metropolitan, India. The

  11. Agricultural land cover changes in metropolitan areas of Poland for the period 1990–2012

    Directory of Open Access Journals (Sweden)

    Nalej Marta

    2016-06-01

    Full Text Available Agricultural land covers more than half the area of metropolitan areas in Poland, and is therefore particularly prone to the influences of the processes associated with their development. The aim of the study was to analyse changes in agricultural land cover within the metropolitan areas of Poland for the years 1990–2012; and to capture their dynamics, types and directions. The percentage share of the total study area, for each of the forms of agricultural land cover and their changes were traced, with the spatial distribution of the changes also being determined. The results of the study show that in metropolitan areas, agricultural land cover is undergoing transformations that do not result in the loss of agricultural lands, or that involve a decrease in surface area due to their change into anthropogenic forms of land cover. The greatest transitions occurred between 2000 and 2006 and were observed in the outer zones of metropolitan areas.

  12. Political apathy amongst students: A case study of Nelson Mandela Metropolitan University

    Directory of Open Access Journals (Sweden)

    Ntsikelelo B. Breakfast

    2017-09-01

    Full Text Available The primary motivation for this research, in which a qualitative method was employed, was to examine political apathy amongst students at Nelson Mandela Metropolitan University. The secondary motivation was to question whether youth political apathy threatens the consolidation of democracy. The researchers arranged four focus groups at Nelson Mandela Metropolitan University. A purposive sampling technique was utilised. All 50 participants in the study were Nelson Mandela Metropolitan University undergraduate and postgraduate black students, with ages ranging from 21 to 35 years. The researchers encouraged participants to have maximum participation in the focus group deliberations. The researchers also made use of elite interviews in the study. The findings of this study suggest that political apathy does exist amongst students at Nelson Mandela Metropolitan University. Most of the participants in the focus groups indicated that young people in post-apartheid South Africa have no interest in politics.

  13. Regional transportation and land use decision making in metropolitan regions : findings from four case studies.

    Science.gov (United States)

    2012-02-01

    "Throughout the United States, metropolitan regions face increasingly complex issues related to transportation and : land use. The diffuse nature of decision making creates a need to better coordinate land use and transportation to : address issues s...

  14. The Age of Environmental Impasse? Globalization and Environmental Transformation of Metropolitan Cities

    NARCIS (Netherlands)

    Melchert Saguas Presas, L.

    2005-01-01

    Metropolitan cities are undergoing a major spatial and environmental transformation. The proliferation of business districts, corporate headquarters and international hotels is prompting a massive verticalization and densification of land use, which is affecting the urban environment and

  15. Spatial clustering of knowledge-based industries in the Helsinki Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Juan Eduardo Chica

    2016-01-01

    Full Text Available The central locations of metropolitan areas have some specific attributes, leading to an accumulation of large knowledge exchanges and extensive knowledge externalities, which encourage the concentration of various economic activities, especially knowledge-based industries (KBI. Other agglomeration economies found in metropolitan areas – such as telecommunications and transport infrastructures connected to global productive circuits and complementary labour markets – are key factors for KBI employment growth. This paper explores the Helsinki Metropolitan Area’s (HMA spatial clustering of KBI at the sub-district level, and the role played by agglomeration economies (both specialization and diversity economies in fostering this process. The results reveal that KBI employment shows patterns of concentration in the core and adjacent areas. The specialization and diversity economies found in the metropolitan core and the specialization economies found in others areas lead to KBI spatial clustering in the HMA. Public policies regarding the promotion of science parks have also played a decisive role.

  16. Partners In Motion And Customer Satisfaction In The Washington Dc Metropolitan Area

    Science.gov (United States)

    1999-06-01

    PARTNERS IN MOTION IS A PROGRAM AIMED AT IMPROVING THE QUALITY, QUANTITY, AND AVAILABILITY OF TRAVEL INFORMATION TO TRANSPORTATION AGENCIES, THE MEDIA, AND, ULTIMATELY, TO THE TRAVELER IN THE WASHINGTON, D.C. METROPOLITAN AREA. THE PROGRAM WAS INITIA...

  17. Behavioral Risk Factors: Selected Metropolitan Area Risk Trends (SMART) MMSA Prevalence Data (2010 and Prior)

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2002-2010. BRFSS SMART MMSA Prevalence land line only data. The Selected Metropolitan Area Risk Trends (SMART) project uses the Behavioral Risk Factor Surveillance...

  18. Behavioral Risk Factors: Selected Metropolitan Area Risk Trends (SMART) MMSA Prevalence Data (2011 to Present)

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2011 to present. BRFSS SMART MMSA Prevalence combined land line and cell phone data. The Selected Metropolitan Area Risk Trends (SMART) project uses the Behavioral...

  19. The New England Drought Study: Water Resources Planning Metropolitan Boston, Massachusetts

    National Research Council Canada - National Science Library

    Joyce, Charles

    1994-01-01

    .... The drought of the 1960s precipitated a debate between the operators of the metropolitan Boston water system and interested citizens and citizens' groups, who were opposed to a structural solution...

  20. Behavioral Risk Factors: Selected Metropolitan Area Risk Trends (SMART) County Prevalence Data (2011 to 2012)

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2011 to 2012. BRFSS SMART County Prevalence combined land line and cell phone data. The Selected Metropolitan Area Risk Trends (SMART) project uses the Behavioral...

  1. South Platte Watershed from the Headwaters to the Denver Metropolitan Area (Colorado) Systems Thinking

    Science.gov (United States)

    South Platte Watershed from the Headwaters to the Denver Metropolitan Area (Colorado) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating

  2. Can Maine metropolitan planning organizations (MPOs) finance transportation projects through bond financing?

    Science.gov (United States)

    2008-12-01

    In January 2008 the Maine metropolitan planning organizations (MPOs) requested the Transportation : Research Division of the Maine Department of Transportation to conduct research to determine if it is : possible for MPOs to finance projects through ...

  3. Strauss, R.: Symphony in F minor, Op. 12... Tokyo Metropolitan Symphony Orchestra / David Nice

    Index Scriptorium Estoniae

    Nice, David

    1994-01-01

    Uuest heliplaadist "Strauss, R.: Symphony in F minor, Op. 12... Tokyo Metropolitan Symphony Orchestra / Hiroshi Wakasugi. Denon CD CO-75 860 (54 minutes); Symphony - comparative version: SNO, Järvi" (8/93)(CHAN) CHAN 9166

  4. The freight landscape : using secondary data sources to describe metropolitan freight flows.

    Science.gov (United States)

    2015-12-01

    Metropolitan areas around the world are seeking to better manage freight flows and reduce negative impacts on local populations. A major challenge to better urban freight management is the lack of data; little is known about freight movements at the ...

  5. The freight landscape : using secondary data sources to describe metropolitan freight flows : final report.

    Science.gov (United States)

    2015-12-01

    Metropolitan areas around the world are seeking to better manage freight flows and reduce negative impacts on local populations. A major challenge to better urban freight management is the lack of data; little is known about freight movements at the ...

  6. Washington DC Metropolitan Area Drug Study Household and Non-Household Populations (DC-MADSH-1991)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The DC Metropolitan Area Drug Study (DCMADS) was conducted in 1991, and included special analyses of homeless and transient populations and of women delivering live...

  7. Behavioral Risk Factors: Selected Metropolitan Area Risk Trends (SMART) County Prevalence Data (2010 and prior)

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2002-2010. BRFSS SMART County Prevalence land line only data. The Selected Metropolitan Area Risk Trends (SMART) project uses the Behavioral Risk Factor Surveillance...

  8. Washington DC Metropolitan Area Drug Study Homeless and Transient Population (DC-MADST-1991)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The DC Metropolitan Area Drug Study (DCMADS) was conducted in 1991, and included special analyses of homeless and transient populations and of women delivering live...

  9. Spatial analysis of the Rio de Janeiro metropolitan area and social and environmental management issues

    DEFF Research Database (Denmark)

    Ribeiro, Gustavo

    2005-01-01

    and infrastructural data. Through these three levels of spatial analysis it is possible to develop and to support a more comprehensible study of urban development of the Rio de Janeiro Metropolitan Area. The aim of this study is (a) to develop an alternative spatial analysis leading to a more comprehensive...... understanding of the urban development process and its correlation not just with political-administrative borders but also to ecological systems: (b) to identify the correlations between infrastructure and socio-economical data in the Rio de Janeiro Metropolitan Area (c) to evaluate urban development dynamics...... in the period between 1990 and 2000, based on the application of the above-mentioned data to the three spatial levels in question. This paper highlights the role of the hydrographical systems of the Rio de Janeiro Metropolitan Area as an important spatial unit of analysis to understand the metropolitan urban...

  10. Uudised : Õhtu Metropolitan Operas. Järvi Michigani ülikooli audoktoriks / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    1999-01-01

    "Klassikaraadio" vahendab 25. dets. otseülekande New Yorgist Metropolitan Operast, kus tuleb ettekandele W.A. Mozarti ooper "Figaro pulm". 19. dets. nimetati N. Järvi Michigani ülikooli audoktoriks

  11. Uudised : ERSO menu Rootsis. Õhtu Metropolitan Operas. NYYD Ensemble'i kontserdid / Madis Kolk

    Index Scriptorium Estoniae

    Kolk, Madis, 1953-

    2001-01-01

    ERSO kontserdireisist Rootsis. "Klassikaraadio" teeb 17. veebr. otseülekande New Yorgi Metropolitan Operast, kus tuleb ettekandele Rossini ooepr "Itaallanna Alzhiiris". NYYD Ensemble'i kontsertidest Pärnus ja Tallinnas kontserdisarjas "I Got Rhythm"

  12. FINE PORE DIFFUSER SYSTEM EVALUATION FOR THE GREEN BAY METROPOLITAN SEWERAGE DISTRICT

    Science.gov (United States)

    The Green Bay Metropolitan Sewerage District retrofitted two quadrants of their activated sludge aeration system with ceramic and membrane fine pore diffusers to provide savings in energy usage compared to the sparged turbine aerators originally installed. Because significant di...

  13. The New England Drought Study: Water Resources Planning Metropolitan Boston, Massachusetts

    National Research Council Canada - National Science Library

    Joyce, Charles

    1994-01-01

    The study has traced the water resources planning experience for the metropolitan Boston area from the 17th century to the present in order to investigate how current planning has evolved from seeking...

  14. Los Angeles County Metropolitan Transportation Authority climate change adaptation pilot project report.

    Science.gov (United States)

    2013-08-01

    This Climate Change Adaptation Pilot Project Report details the project background of the recently-completed Los Angeles County : Metropolitan Transportation Authority (Metro) Transit Climate Change Adaptation Pilot Project as well as the various wor...

  15. URBANIZATION AND SPATIAL CHANGES IN DEMOGRAPHIC CHARACTERISTICS IN MONTERREY METROPOLITAN REGION

    Directory of Open Access Journals (Sweden)

    Arun Kumar Acharya

    2011-10-01

    Full Text Available This paper tries to explore the process of urbanization and spatial changes in demographic features in the Monterrey Metropolitan Region (MMR, Mexico. This city is the third largest urban sector in Mexico which has around 4 million population. It is also the industrial and economic capital of the country. The present study found that rapid urbanization in the metropolitan region has a close association with process of industrialization. In population distribution and composition, study found that the metropolitan region had its “demographic transition” during the years seventies and currently the region is taking advantages of demographic bonus cohort, i.e. a higher concentration of population in economic active groups compare to children and old age population. However, this paper indentified a higher imbalance in metropolitan demographic scenario. On the one hand, there is di-populization in the city center region and in other there is a steady increment of population in peri-urban region.

  16. Working paper : national costs of the metropolitan ITS infrastructure : updated with 2004 deployment data

    Science.gov (United States)

    The purpose of this report, "Working Paper National Costs of the Metropolitan ITS infrastructure: Updated with 2004 Deployment Data," is to update the estimates of the costs remaining to deploy Intelligent Transportation Systems (ITS) infrastructure ...

  17. Access to destinations : annual accessibility measure for the Twin Cities Metropolitan Region.

    Science.gov (United States)

    2012-11-01

    This report summarizes previous phases of the Access to Destinations project and applies the techniques developed : over the course of the project to conduct an evaluation of accessibility in the Twin Cities metropolitan region for : 2010. It describ...

  18. Movement Technologies, Scale Structure and Metropolitan Life – an Empirical Research on the Effects of the Transportation System on the Metropolitan Process in Beijing

    Directory of Open Access Journals (Sweden)

    Qiang Sheng

    2014-07-01

    Full Text Available This paper is a morphological study on Beijing’s metropolitanisation process based on the development of its transportation networks. By extracting the ‘scale structure’ embedded in them, we construct a movement network model for Beijing and use it to analyse changing metropolitan centralities as shopping areas and market places in 1924, 1987 and 2006. Following Taylor’s proposal of Central Flow as a complementary model to Central Place, our study focuses on how the spatial distribution of metropolitan centralities has been affected by the rapid modernisation of transportation networks.

  19. The metropolitan VoD system based on ethernet/SCM PON

    Science.gov (United States)

    Ji, Wei; Yang, Hongliang; Feng, Dejun; Liu, Yang; Sun, Jande

    2008-11-01

    VoD is a very attractive service which used for entertainment, education and other purposes. In this paper, we present an evolution method that integrates the EPON and SCM-PON by WDM technology to provide high dedicated bandwidth for the metropolitan VoD services. Using DVB, IPTV protocol, unicasting and broadcasting method to maximize the system throughput and by numerical analysis, the hybrid PON system can implement the metropolitan VoD services.

  20. The Challenge of Forecasting Metropolitan Growth: Urban Characteristics Based Models versus Regional Dummy Based Models

    OpenAIRE

    NA

    2005-01-01

    This paper presents a study of errors in forecasting the population of Metropolitan Statistical Areas and the Primary MSAs of Consolidated Metropolitan Statistical Areas and New England MAs. The forecasts are for the year 2000 and are based on a semi-structural model estimated by Mills and Lubelle using 1970 to 1990 census data on population, employment and relative real wages. This model allows the testing of regional effects on population and employment growth. The year 2000 forecasts are f...

  1. Assessing the Impact of Chlorinated-Solvent Sites on Metropolitan Groundwater Resources

    OpenAIRE

    Brusseau, Mark L.; Narter, Matthew

    2013-01-01

    Chlorinated-solvent compounds are among the most common groundwater contaminants in the U.S.A. The majority of the many sites contaminated by chlorinated-solvent compounds are located in metropolitan areas, and most such areas have one or more chlorinated-solvent contaminated sites. Thus, contamination of groundwater by chlorinated-solvent compounds may pose a potential risk to the sustainability of potable water supplies for many metropolitan areas. The impact of chlorinated-solvent sites on...

  2. The Hydro-Economic Interdependency of Cities: Virtual Water Connections of the Phoenix, Arizona Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Richard R. Rushforth

    2015-06-01

    Full Text Available Water footprinting has revealed hydro-economic interdependencies between distant global geographies via trade, especially of agricultural and manufactured goods. However, for metropolitan areas, trade not only entails commodity flows at many scales from intra-municipal to global, but also substantial intra-metropolitan flows of the skilled labor that is essential to a city’s high-value economy. Virtual water flows between municipalities are directly relevant for municipal water supply policy and infrastructure investment because they quantify the hydro-economic dependency between neighboring municipalities. These municipalities share a physical water supply and also place demands on their neighbors’ water supplies by outsourcing labor and commodity production outside the municipal and water supply system boundary to the metropolitan area. Metropolitan area communities span dense urban cores to fringe agricultural towns, spanning a wide range of the US hydro-economy. This study quantifies water footprints and virtual water flows of the complete economy of the Phoenix Metropolitan Area’s municipalities. A novel approach utilized journey to work data to estimate virtual water flows embedded in labor. Commodities dominate virtual water flows at all scales of analysis, however labor is shown to be important for intra-metropolitan virtual water flows. This is the first detailed water footprint analysis of Phoenix, an important city in a water-scarce region. This study establishes a hydro-economic typology for communities to define several niche roles and decision making points of view. This study’s findings can be used to classify communities with respect to their relative roles, and to benchmark future improvements in water sustainability for all types of communities. More importantly, these findings motivate cooperative approaches to intra-metropolitan water supply policy that recognize the hydro-economic interdependence of these

  3. Public Hearing: Report of the Proceedings of a Public Hearing of the Task Force on Women, Minorities and the Handicapped in Science and Technology (Atlanta, Georgia, March 2, 1988).

    Science.gov (United States)

    Task Force on Women, Minorities, and the Handicapped in Science and Technology, Washington, DC.

    The Task Force on Women, Minorities, and the Handicapped in Science and Technology was established by the U.S. Congress in Public Law 99-383 with the purpose of developing a long-range plan for broadening participation in science and engineering. Public hearings were held in Albuquerque (New Mexico), Atlanta (Georgia), Baltimore (Maryland), Boston…

  4. Atomic-scale structure of irradiated GaN compared to amorphised GaP and GaAs

    International Nuclear Information System (INIS)

    Ridgway, M.C.; Everett, S.E.; Glover, C.J.; Kluth, S.M.; Kluth, P.; Johannessen, B.; Hussain, Z.S.; Llewellyn, D.J.; Foran, G.J.; Azevedo, G. de M.

    2006-01-01

    We have compared the atomic-scale structure of ion irradiated GaN to that of amorphised GaP and GaAs. While continuous and homogenous amorphised layers were easily achieved in GaP and GaAs, ion irradiation of GaN yielded both structural and chemical inhomogeneities. Transmission electron microscopy revealed GaN crystallites and N 2 bubbles were interspersed within an amorphous GaN matrix. The crystallite orientation was random relative to the unirradiated epitaxial structure, suggesting their formation was irradiation-induced, while the crystallite fraction was approximately constant for all ion fluences beyond the amorphisation threshold, consistent with a balance between amorphisation and recrystallisation processes. Extended X-ray absorption fine structure measurements at the Ga K-edge showed short-range order was retained in the amorphous phase for all three binary compounds. For ion irradiated GaN, the stoichiometric imbalance due to N 2 bubble formation was not accommodated by Ga-Ga bonding in the amorphous phase or precipitation of metallic Ga but instead by a greater reduction in Ga coordination number

  5. Cooling effect of rivers on metropolitan Taipei using remote sensing.

    Science.gov (United States)

    Chen, Yen-Chang; Tan, Chih-Hung; Wei, Chiang; Su, Zi-Wen

    2014-01-23

    This study applied remote sensing technology to analyze how rivers in the urban environment affect the surface temperature of their ambient areas. While surface meteorological stations can supply accurate data points in the city, remote sensing can provide such data in a two-dimensional (2-D) manner. The goal of this paper is to apply the remote sensing technique to further our understanding of the relationship between the surface temperature and rivers in urban areas. The 2-D surface temperature data was retrieved from Landsat-7 thermal infrared images, while data collected by Formosat-2 was used to categorize the land uses in the urban area. The land surface temperature distribution is simulated by a sigmoid function with nonlinear regression analysis. Combining the aforementioned data, the range of effect on the surface temperature from rivers can be derived. With the remote sensing data collected for the Taipei Metropolitan area, factors affecting the surface temperature were explored. It indicated that the effect on the developed area was less significant than on the ambient nature zone; moreover, the size of the buffer zone between the river and city, such as the wetlands or flood plain, was found to correlate with the affected distance of the river surface temperature.

  6. Water management for a megacity: Mexico City Metropolitan Area.

    Science.gov (United States)

    Tortajada, Cecilia; Castelán, Enrique

    2003-03-01

    The paper presents an overview of the present situation of the Mexico City Metropolitan Area (MCMA). The analysis indicates an urgent need to radically improve the current water supply and wastewater management practices, to become sustainable. The MCMA is one of the most rapidly growing urban centers of the world, with a population of about 21 million people, a very high rate of immigration and numerous illegal settlements. In order to meet the increasing water demand, successive governments have focused almost exclusively on supply management and engineering solutions, which have resulted in investments of hundreds of millions of USD and the construction of major infrastructure projects for interbasin water transfer. Environmental, economic and social policies associated with water management are mostly inadequate and insufficient, which is resulting in increasing deterioration in the environment, health and socioeconomic conditions of a population living in one of the largest urban agglomerations of the world. Surprisingly, however, no long-term strategies on demand-management, reuse, conservation, and improved water-management practices have been developed so far.

  7. Secular variations of radon in metropolitan Vancouver, British Columbia, Canada

    International Nuclear Information System (INIS)

    Ghomshei, M.M.; Slawson, W.F.

    1990-01-01

    In this paper sampling of radon within the soil from three sites in metropolitan Vancouver is reported. Alpha trace bi-weekly measurements during a period of 4 years show secular variations with a period of 8-15 months. There are low-radon and high-radon episodes enduring several months to a year. Average radon level during the high-radon episodes reaches 5-10 times that of the low-radon periods. During high-radon episodes the high-frequency variations show very high amplitudes. After filtering of the high-frequency fluctuations, the data from different sites demonstrate remarkably similar trends. It is suggested that along with hydrogeological events, stress relaxation in rocks, earthquake, and magma emplacement may contribute to the sources of secular variations of radon. Because of long-term variations, radon level in urban areas should be monitored on a continuous basis. Single measurements, even those integrating radiation over a period of few months, may sample a low-radon episode, and provide a false assurance, or occur during a high-radon episode and give a false alarm

  8. EVALUATION OF PRIVATE SCHOOL LOCATION IN THE ISTANBUL METROPOLITAN AREA

    Directory of Open Access Journals (Sweden)

    Mehmet TOPÇU

    2014-01-01

    Full Text Available Investment in education is considered important for economic growth and poverty alleviation. In many developed and developing countries families contribute privately to the education of their children as a result of continuously shrinking public budgets. Also, in Istanbul private primary schools were supported by the government in order to answer to increasing demand due to continuous rural migration and to create a competitive educational market to improve the quality of primary education. This paper, first, analyzes the spatial distribution of private primary schools according to the concentric rings and illustrates the gap between the center and the periphery and among the districts. Then, the relationships between the number of private primary schools and demand and the characteristics of the districts are investigated by a regression analysis. According to the results, the number of public primary schools is the most important factor and GDP per capita is the second factor to affect the number of private primary schools in the districts. Currently, the cluster of private primary schools mainly in high-income districts does not allow developing a competitive educational market at the metropolitan level. It is expected that a more balanced market will be develop as the urban structure of Istanbul adjusted to the neo-liberal economies in the future. The results are useful for urban planners, investors and policy makers. Further research is suggested to investigate the impact of private primary schools on the quality of public primary school education in Istanbul.

  9. Aspects of Land Take in the Metropolitan Area of Naples

    Directory of Open Access Journals (Sweden)

    Giuseppe Mazzeo

    2016-03-01

    Full Text Available Land take is a phenomenon of great concern nowadays because of the large number of its negative impacts regarding biological, economic and social balance. In Italy, the development of urban and other artificial land has been irreversibly transforming a non-renewable resource such as soil, regardless the almost constant population rate, with different speed depending of the region considered. The aim of this paper is to analyze the phenomenon in the metropolitan area of Naples, which is an area highly affected by territorial aggression of human matrix. The data used are both by the Institute for Environmental Protection and Research (ISPRA Report 2015 on the usage of the land and by ISTAT relating to the resident population up to the 1st of January 2015 and the extension of land for agricultural use (Census 2010. The mathematical combination of this data creates a new indicator that can be referred to as “residual land”; this residual area is of great extension with many different characteristics and it could represent the area where the phenomenon of land take most occurs. The identification, measurement and analysis of “residual land” provide new insights on the evolution of land take and this new indicator can represent a critical element to work on to prevent future land transformation and protect natural and agricultural areas within the Italian context.

  10. Marketing paediatric influenza vaccination: results of a major metropolitan trial

    Science.gov (United States)

    Van Buynder, Paul G.; Carcione, Dale; Rettura, Vince; Daly, Alison; Woods, Emily

    2010-01-01

    Please cite this paper as: Van Buynder et al. (2010) Marketing paediatric influenza vaccination: results of a major metropolitan trial. Influenza and Other Respiratory Viruses 5(1), 33–38. Objectives  After a cluster of rapidly fulminant influenza related toddler deaths in a Western Australian metropolis, children aged six to 59 months were offered influenza vaccination in subsequent winters. Some parental resistance was expected and previous poor uptake of paediatric influenza vaccination overseas was noted. A marketing campaign addressing barriers to immunization was developed to maximise uptake. Design  Advertising occurred in major statewide newspapers, via public poster displays and static ‘eye‐lite’ displays, via press releases, via a series of rolling radio advertisements, via direct marketing to child care centres, and via a linked series of web‐sites. Parents were subsequently surveyed to assess reasons for vaccination. Main Outcome Results  The campaign produced influenza vaccination coverage above that previously described elsewhere and led to a proportionate reduction in influenza notifications in this age group compared to previous seasons. Conclusions  Influenza in children comes with significant morbidity and some mortality. Paediatric influenza vaccination is safe, well tolerated and effective if two doses are given. A targeted media campaign can increase vaccine uptake if it reinforces the seriousness of influenza and addresses community ‘myths’ about influenza and influenza vaccine. The lessons learned enabling enhancements of similar programs elsewhere. PMID:21138538

  11. Characterization of aerosols in the Metropolitan Area of San Jose

    International Nuclear Information System (INIS)

    Mejias Perez, J.A.

    1997-07-01

    The objective of the present study, was to elaborate a profile of the contamination by private matter and to characterize the aerosols collected in the Metropolitan Area of San Jose (Costa Rica). For that, a campaign of sampling was carried out in three points of the city of San Jose, differentiated by there degree of activity: Center of San Jose (Central Station of Firemen), San Isidro of Coronado -Canton of Vasquez of Coronado- (Municipality) and Escazu (Municipality). Such campaign was carried out from April 4 to July 4, 1996 (transition summer-winter), and in two periods of time of 8 hours: 8 a.m. to 4 p.m. and of 8 p.m. to 4 a.m. The aerosols were collected utilizing Gent Pm-10 samplers, in filters of polycarbonate of 0,4 μm and 8 μm in cascade, with a flow average of 15 L/min., and it determined the composition average of the present aerosols. The concentration of the majority of the anions were obtained by means of ionic chromatography of high resolution, and the main cations by spectrophotometry of atomic absorption with electro thermic atomization. The space-temporary variations of the concentrations were evaluated and their correlation with the meteorologic variable. (S. Grainger) [es

  12. Emissions inventory for the Mexico City Metropolitan Area

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, V.H.P.; Renteria, J.S. [Secretaria de Medio Ambiente, Col. Tiacopac San Angel (Mexico); Hernandez, C.G. [Departamento del Distrito Federal, Col. Centro (Mexico)] [and others

    1996-12-31

    The emissions inventory bears a broad relationship to the energy balance, reflecting the dependence of the emissions with reference to the use of energy. Actually the consumption of gasoline and diesel fuel in the transport sector represents collectively, the greatest comparative expense of energy and the major contributor of the ozone precursor pollutants HC, NO{sub x} and CO, relative to the total volume of emissions in the Mexico City Metropolitan Area (MCMA). Also, the industrial sector introduces significant emissions of SO{sub 2} and NO{sub x} due to its energy consumption of fuel oils and natural gas. In contrast, the great majority of suspended particulate in the MCMA emanate from degradation processes of surface soil along the periphery of the urban zone. To the federal and local authorities charged with the design of strategies for prevention and control of atmospheric pollution, the emissions inventory is a strategic tool that reflects the relative intensity of the various emitters to the load capacity of the atmosphere. A comprehensive inventory was compiled for 1995, categorizing the emissions generated by four sectors: industry, services, transport and surface soils and vegetation, considering the following pollutants: TSP, SO{sub 2}, NO{sub x}, HC and CO. The combined pollutant emissions are 4,009,628 tons/year of which 3% are generated by the industry, 10% by the services sector, 75% by the transport sector, and 12% by surface soils and vegetation.

  13. E-book Collections in Academic Libraries of Metropolitan Tehran

    Directory of Open Access Journals (Sweden)

    Sepideh Fahimifar

    2008-04-01

    Full Text Available In the present age users not only need to have access information, but they need to have access as fast and as easy as possible. This is one of the reasons that has intensified the current ICT applications and the growing need for it. Today not only countless journals are published in electronic format side by side with their printed versions, but numerous books on diverse subjects are published elecrtronically. To better serve their patrons, academic libraries should also collect electronic books along with printed resources. Managers of academic libraries must consider acquisition of various types of electronic books and provision of facilities for accessing. The present paper initially offers the definitions offered with respect to e-books as well as the workshops held globally, researches carried out in academic libraries as well as the categories of information contained in e-books. It would then investigates the various types of e-books held in the academic libraries within metropolitan Tehran and describes the access method for students and patrons. A survey , using questionnaire as a data collection instrument, was conducted .

  14. Evaluation of sludge management alternatives in Istanbul metropolitan area.

    Science.gov (United States)

    Cakmakci, M; Erdim, E; Kinaci, C; Akca, L

    2005-01-01

    The main concern of this paper was to predict the sludge quantities generated from 18 wastewater treatment plants, which were stated to be established in the "Istanbul Water Supply, Sewerage and Drainage, Sewage Treatment and Disposal Master Plan", 10 of which are in operation at present. Besides this, obtaining the required data to compare various treatment schemes was another goal of the study. Especially, the estimation of the sludge quantity in the case of enhanced primary sedimentation was of importance. Wastewater sludge management strategies were discussed in order to develop suggestions for Istanbul Metropolitan city. Within this context, the wastewater treatment facilities, mentioned in the Master Plan that had been completed by 2000, were evaluated in terms of sludge production rates, locations and technical and management aspects. Disposal alternatives of the wastewater treatment sludge were also evaluated in this study. Using of the dewatered sludge as a landfill cover material seems the best alternative usage. Up to the year of 2040, the requirement of cover material for landfills in Istanbul will be met by the dewatered sludge originated from wastewater treatment plants in the region.

  15. Perspectives and limitations of QKD integration in metropolitan area networks.

    Science.gov (United States)

    Aleksic, Slavisa; Hipp, Florian; Winkler, Dominic; Poppe, Andreas; Schrenk, Bernhard; Franzl, Gerald

    2015-04-20

    Quantum key distribution (QKD) systems have already reached a reasonable level of maturity. However, a smooth integration and a wide adoption of commercial QKD systems in metropolitan area networks has still remained challenging because of technical and economical obstacles. Mainly the need for dedicated fibers and the strong dependence of the secret key rate on both loss budget and background noise in the quantum channel hinder a practical, flexible and robust implementation of QKD in current and next-generation optical metro networks. In this paper, we discuss these obstacles and present approaches to share existing fiber infrastructures among quantum and classical channels. Particularly, a proposal for a smooth integration of QKD in optical metro networks, which implies removing spurious background photons caused by optical transmitters, amplifiers and nonlinear effects in fibers, is presented and discussed. We determine and characterize impairments on quantum channels caused by many classical telecom channels at practically used power levels coexisting within the same fiber. Extensive experimental results are presented and indicate that a practical integration of QKD in conventional optical metro networks is possible.

  16. Metropolitan area networks: a corner stone in the broadband era

    Science.gov (United States)

    Ghanem, Adel

    1991-02-01

    Deployment of Broadband ISDN is being influenced by both a market pull and a technology push. New broadband service opportunities exist in the business and residential sectors of the market place. It is envisioned that some customers will need connections directly to broadband switches because of the high bandwidth needed for their applications. At the same time Metropolitan Area Network (MAN) systems will serve those customers with bandwidth requirements less than or equal to 150 Mbps. A given MAN will have a geographical domain to serve where it will carry out the switching tasks within this domain. While MANs couldbe designed using differentarchitecturalconcepts the setofservices expected tobeprovidedby MANs could be equivalent to thelist ofservices thatwillbe supported by the targetbroadband network. This paperpositions MANs as a major building block for Broadband networks. It also examines the evolution process ofMANs as a needed step to assure the successful deployment of these new broadband services. 2. BISDN - OVERVIEW Broadband ISDN (BISDN) is being driven into existence by both a market pull as well as a technology push. Opportunities for new valueadded services are the prime market pull for future broadband networks. These services opportunities extend beyond simple voice and low speed data applications and cover both the residential and the business sectors of the market. It is noted for instance that business customers have growing needs for sophisticated telecommunication vehicles to support their

  17. Assessment of rain water chemistry in the Lucknow metropolitan city

    Science.gov (United States)

    Sharma, Purnima; Rai, Vibhuti

    2018-05-01

    Lucknow metropolitan city is one of the most populated cities of India, which have been facing many problems such as chaotic urbanization, overpopulation, water scarcity, waterlogging, etc., among these water scarcity is one of the important problem. Rain water harvesting is a futuristic tool for mitigation of water scarcity problem through conservation and storage of rain water. This rain water can be used for all purposes by human beings, thus it is necessary to check the chemistry of rain water. The rain water samples were collected from the five zones of Lucknow city. For the comparative study, water samples have been collected from two different dates first from first rainfall and second after 3 days of interval in the second rainfall. The heavy metal concentrations were found in both first and second rainfall water samples in all zones of Lucknow city. The concentration of chromium, cadmium and lead were found to be sufficiently high in several samples. These heavy metals show the concentration above the permissible limit as set by WHO, which can cause various adverse health impacts.

  18. Truck transport of RAM: Risk effects of avoiding metropolitan areas

    International Nuclear Information System (INIS)

    Mills, G.S.; Neuhauser, K.S.

    1997-11-01

    In the transport of radioactive material (RAM), e.g., spent nuclear fuel (SNF), stakeholders are generally most concerned about risks in high population density areas along transportation routes because of the perceived high consequences of potential accidents. The most significant portions of a transcontinental route and an alternative examined previously were evaluated again using population density data derived from US Census Block data. This method of characterizing population that adjoins route segments offers improved resolution of population density variations, especially in high population density areas along typical transport routes. Calculated incident free doses and accident dose risks for these routes, and the rural, suburban and urban segments are presented for comparison of their relative magnitudes. The results indicate that modification of this route to avoid major metropolitan areas through use of non-Interstate highways increases total risk yet does not eliminate a relatively small urban component of the accident dose risk. This conclusion is not altered by improved resolution of route segments adjoining high density populations

  19. Face Recognition by Metropolitan Police Super-Recognisers.

    Science.gov (United States)

    Robertson, David J; Noyes, Eilidh; Dowsett, Andrew J; Jenkins, Rob; Burton, A Mike

    2016-01-01

    Face recognition is used to prove identity across a wide variety of settings. Despite this, research consistently shows that people are typically rather poor at matching faces to photos. Some professional groups, such as police and passport officers, have been shown to perform just as poorly as the general public on standard tests of face recognition. However, face recognition skills are subject to wide individual variation, with some people showing exceptional ability-a group that has come to be known as 'super-recognisers'. The Metropolitan Police Force (London) recruits 'super-recognisers' from within its ranks, for deployment on various identification tasks. Here we test four working super-recognisers from within this police force, and ask whether they are really able to perform at levels above control groups. We consistently find that the police 'super-recognisers' perform at well above normal levels on tests of unfamiliar and familiar face matching, with degraded as well as high quality images. Recruiting employees with high levels of skill in these areas, and allocating them to relevant tasks, is an efficient way to overcome some of the known difficulties associated with unfamiliar face recognition.

  20. Mammography screening among Arab American women in metropolitan Detroit.

    Science.gov (United States)

    Schwartz, Kendra; Fakhouri, Monty; Bartoces, Monina; Monsur, Joseph; Younis, Amani

    2008-12-01

    Mammography screening behavior has not been well studied among Middle Eastern immigrant women. We conducted a telephone survey of 365 Arab American women residing in metropolitan Detroit, home to one of the largest populations of Middle Eastern immigrants in the US, to determine prevalence of factors associated with mammography, and attitudes and beliefs regarding mammography screening. Of 365 participants, only five were born in the US. Mean age was 53.2 years (SD 10.8). Two hundred twelve (58.1%) reported having mammogram every 1-2 years; 70% ever had mammogram. Age 50-64 years, having health insurance, married status, being in the US over 10 years, and being Lebanese were associated with mammography every 1-2 years. After adjusting for demographic factors, perceived seriousness of disease, general health motivation, and having fewer barriers were associated with more frequent screening. Appropriate mammography screening is decreased in this group. Targeted outreach regarding screening is appropriate for this population; however, lack of insurance may prevent adequate follow-up.

  1. A slotted access control protocol for metropolitan WDM ring networks

    Science.gov (United States)

    Baziana, P. A.; Pountourakis, I. E.

    2009-03-01

    In this study we focus on the serious scalability problems that many access protocols for WDM ring networks introduce due to the use of a dedicated wavelength per access node for either transmission or reception. We propose an efficient slotted MAC protocol suitable for WDM ring metropolitan area networks. The proposed network architecture employs a separate wavelength for control information exchange prior to the data packet transmission. Each access node is equipped with a pair of tunable transceivers for data communication and a pair of fixed tuned transceivers for control information exchange. Also, each access node includes a set of fixed delay lines for synchronization reasons; to keep the data packets, while the control information is processed. An efficient access algorithm is applied to avoid both the data wavelengths and the receiver collisions. In our protocol, each access node is capable of transmitting and receiving over any of the data wavelengths, facing the scalability issues. Two different slot reuse schemes are assumed: the source and the destination stripping schemes. For both schemes, performance measures evaluation is provided via an analytic model. The analytical results are validated by a discrete event simulation model that uses Poisson traffic sources. Simulation results show that the proposed protocol manages efficient bandwidth utilization, especially under high load. Also, comparative simulation results prove that our protocol achieves significant performance improvement as compared with other WDMA protocols which restrict transmission over a dedicated data wavelength. Finally, performance measures evaluation is explored for diverse numbers of buffer size, access nodes and data wavelengths.

  2. Influence of AlGaN/GaN superlattice inserted structure on the performance of InGaN/GaN multiple quantum well light emitting diodes

    International Nuclear Information System (INIS)

    Wang, C.-L.; Tsai, M.-C.; Gong, J.-R.; Liao, W.-T.; Lin, P.-Y.; Yen, K.-Y.; Chang, C.-C.; Lin, H.-Y.; Hwang, S.-K.

    2007-01-01

    Investigations were conducted to explore the effect of Al 0.3 Ga 0.7 N/GaN short-period superlattice (SPSL)-inserted structures in the GaN under layer on the performance of In 0.2 Ga 0.8 N/GaN multiple quantum well (MQW) light emitting diodes (LEDs). The Al 0.3 Ga 0.7 N/GaN SPSL-inserted LEDs were found to exhibit improved materials and device characteristics including decrements in ideality factor and reverse leakage current. The results of etch pit counts reveal that SPSL-induced threading dislocation density reduction in the SPSL-inserted In 0.2 Ga 0.8 N/GaN MQW LED structures enables the improved LED performance

  3. InGaP/InGaAsN/GaAs NpN double-heterojunction bipolar transistor

    International Nuclear Information System (INIS)

    Chang, P. C.; Baca, A. G.; Li, N. Y.; Xie, X. M.; Hou, H. Q.; Armour, E.

    2000-01-01

    We have demonstrated a functional NpN double-heterojunction bipolar transistor (DHBT) using InGaAsN for the base layer. The InGaP/In 0.03 Ga 0.97 As 0.99 N 0.01 /GaAs DHBT has a low V ON of 0.81 V, which is 0.13 V lower than in a InGaP/GaAs heterojunction bipolar transistor (HBT). The lower turn-on voltage is attributed to the smaller band gap (1.20 eV) of metalorganic chemical vapor deposition-grown In 0.03 Ga 0.97 As 0.99 N 0.01 base layer. GaAs is used for the collector; thus the breakdown voltage (BV CEO ) is 10 V, consistent with the BV CEO of InGaP/GaAs HBTs of comparable collector thickness and doping level. To alleviate the current blocking phenomenon caused by the larger conduction band discontinuity between InGaAsN and GaAs, a graded InGaAs layer with δ doping is inserted at the base-collector junction. The improved device has a peak current gain of seven with ideal current-voltage characteristics. (c) 2000 American Institute of Physics

  4. Comparison of electrical characteristic between AlN/GaN and AlGaN/GaN heterostructure Schottky diodes

    International Nuclear Information System (INIS)

    Lü Yuan-Jie; Feng Zhi-Hong; Gu Guo-Dong; Dun Shao-Bo; Yin Jia-Yun; Han Ting-Ting; Cai Shu-Jun; Lin Zhao-Jun

    2014-01-01

    Ni/Au Schottky contacts on AlN/GaN and AlGaN/GaN heterostructures are fabricated. Based on the measured current—voltage and capacitance—voltage curves, the electrical characteristics of AlN/GaN Schottky diode, such as Schottky barrier height, turn-on voltage, reverse breakdown voltage, ideal factor, and the current-transport mechanism, are analyzed and then compared with those of an AlGaN/GaN diode by self-consistently solving Schrödinger's and Poisson's equations. It is found that the dislocation-governed tunneling is dominant for both AlN/GaN and AlGaN/GaN Schottky diodes. However, more dislocation defects and a thinner barrier layer for AlN/GaN heterostructure results in a larger tunneling probability, and causes a larger leakage current and lower reverse breakdown voltage, even though the Schottky barrier height of AlN/GaN Schottky diode is calculated to be higher that of an AlGaN/GaN diode. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  5. Fabrication of p-type porous GaN on silicon and epitaxial GaN

    OpenAIRE

    Bilousov, Oleksandr V.; Geaney, Hugh; Carvajal, Joan J.; Zubialevich, Vitaly Z.; Parbrook, Peter J.; Giguere, A.; Drouin, D.; Diaz, Francesc; Aguilo, Magdalena; O'Dwyer, Colm

    2013-01-01

    Porous GaN layers are grown on silicon from gold or platinum catalyst seed layers, and self-catalyzed on epitaxial GaN films on sapphire. Using a Mg-based precursor, we demonstrate p-type doping of the porous GaN. Electrical measurements for p-type GaN on Si show Ohmic and Schottky behavior from gold and platinum seeded GaN, respectively. Ohmicity is attributed to the formation of a Ga2Au intermetallic. Porous p-type GaN was also achieved on epitaxial n-GaN on sapphire, and transport measurem...

  6. Anomalous disorder-related phenomena in InGaN/GaN multiple quantum well heterosystems

    International Nuclear Information System (INIS)

    Hu, Y.-J.; Huang, Y.-W.; Fang, C.-H.; Wang, J.-C.; Chen, Y.-F.; Nee, T.-E.

    2010-01-01

    The influences of InGaN/GaN multiple quantum well (MQW) heterostructures with InGaN/GaN and GaN barriers on carrier confinement were investigated. The degree of disordering over a broad range of temperatures from 20 to 300 K was considered. The optical and electrical properties were strongly influenced by structural and compositional disordering of the InGaN/GaN MQW heterostructures. To compare the degree of disordering we examined the temperature dependence of the luminescence spectra and electrical conductance contingent on the Berthelot-type mechanisms in the InGaN/GaN MQW heterostructures. We further considered carrier transport in the InGaN/GaN disordered systems, probability of carrier tunneling, and activation energy of the transport mechanism for devices with InGaN/GaN and GaN barriers. The optical properties of InGaN/GaN disordered heterosystems can be interpreted from the features of the absorption spectra. The anomalous temperature-dependent characteristics of the disordered InGaN/GaN MQW structures were attributable to the enhancement of the exciton confinement.

  7. 78 FR 9771 - Notice of Opportunity for Public Comment on Surplus Property Release at Brunswick-Golden Isles...

    Science.gov (United States)

    2013-02-11

    ... address: Atlanta Airports District Office, Attn: Aimee A. McCormick, Program Manager, 1701 Columbia Ave... McCormick, Program Manager, Atlanta Airports District Office, 1701 Columbia Ave., Suite 2-260, Atlanta, GA...

  8. Diurnal variations of indoor radon progeny for Bangalore metropolitan, India

    International Nuclear Information System (INIS)

    Nagesh, V.; Sathish, L.A.; Nagaraja, K.; Sundareshan, S.

    2010-01-01

    Radon progenies are identified as major causes of the lung cancer if the activity is above its normal. It has not been clear whether radon poses a similar risk of causing lung cancer in humans exposed at generally lower levels found in homes, but a number of indoor radon survey have been carried out in recent years around the world. In view of this an attempt has been made for the measurement of diurnal variation of indoor radon levels for the environment of Bangalore metropolitan, India. The Radon progeny concentrations in terms of working level were measured using Kusnetz's method. The patterns of daily and annual changes in indoor Radon concentration have been observed in a general way for many years. However, understanding of the physical basis for these changes had to await the development of continuous monitors and a more complete knowledge of transport processes in the atmosphere. Over a continent, heating of the ground surface by the Sun during the day and cooling by radiation during the night causes a marked diurnal change in temperature near the surface. As a result cool air near the ground will accumulate radon isotopes from surface flux during the night; while during the day the warm air will be transported upward carrying radon with it. Many buildings show diurnal radon variations. Concentrations are relatively higher during night than daytime. This is influenced by the outdoor-indoor temperature contrast. This effect can be enhanced in buildings with strong diurnal use patterns. Buildings that have high average radon concentrations, but are only occupied for part of the day, may need to be measured during occupied periods to determine if there is significant diurnal radon variation. The results are discussed in detail. (author)

  9. Designing Freshwater Resilience for the Mexico City Metropolitan Area

    Science.gov (United States)

    Freeman, S.; Wi, S.; Brown, C.

    2017-12-01

    There are few places in the world where the water management challenges associated with global urbanization are as fully visible as in the Greater Mexico City Metropolitan Area (MCMA). MCMA has a population of 22 million of which only 82% have daily water provision and this figure is projected by local agencies to decrease drastically in the next decade due to population growth, infrastructure degradation and climate change. The city is served by a massive water delivery system, consisting of complex network of infrastructure in the surrounding basins that provides about 40% of the supply for MCMA and is characterized by increasing land use change and competition for water. The remaining 60% of MCMA's water is sourced internally from already depleted groundwater resources whose exploitation also results in significant subsidence throughout the city, further damaging already degraded infrastructure. Consequently, there is interest and need for investments that improve the performance of the freshwater delivery system, including local resources and connected basins, in the face of change and shocks that can be only partially anticipated. The quest for such resilience is a common theme in urban infrastructure design yet practical approaches for achieving it remain nascent. In this study, we use MCMA and the Cutzamala Water supply system to demonstrate a quantitative framework to evaluate investment strategies which seek resilience for the water supply system of MCMA. Multiobjective optimization and decisions under deep uncertainty approaches are used to evaluate the best performing investment portfolios across different resilience performance metrics which encompass social equity, environmental and economic objectives. This analysis shows dynamic system responses that result from different investment portfolios, elucidating difficult planning and management decisions around tradeoffs between allocations as well as performance metrics (e.g short period of total failure

  10. Household dust metal levels in The Sao Paulo metropolitan area

    International Nuclear Information System (INIS)

    Scapin, Valdirene O.; Scapin, Marcos A.; Sato, Ivone M.

    2007-01-01

    A study about household dust is being conducted to determine the level of metal contamination in the Sao Paulo Metropolitan Area (SPMA). The SPMA, with 18 million inhabitants, is one of the largest urban areas of the world, with serious environmental problems, due to the great amount of industries, heavy traffic and the disordered growth of population. The pollutants originate from a multiplicity of indoor and outdoor sources. Indoor sources are originated from residual (hair, skin scales), pets, human activities, construction materials, and furnishings as well as biological material (pollen, insect parts).and outdoor pollution, usually from the urban traffic. The pollutant mixture involved in numerous physical and chemical processes and changes its characteristics with time. Its composition and concentration depend on the strengths of indoor sources, the concentration of pollutants outside and the properties of ventilation and air-conditioning systems. It is well recognized that many metals have chronic effects on humans, in particular toddlers, who are at an higher risk compared to adults because they engage in greater hand to-mouth activity and their neurological systems are still developing. The household dust samples were collected from different localities, using vacuum cleaner, and sieved up to particle size -1 ; Mn, 119-369 μg g -1 ; Fe, 372-1464 μg g -1 ; Ni, 33-85 μg g -1 ; Cu, 42-303 μg g -1 ; Zn, 156-1369 μg g -1 and Pb, 26-160 μg g -1 . (author)

  11. Indoor radon distribution in metropolitan region of Belo Horizonte, Brazil

    International Nuclear Information System (INIS)

    Santos, Talita O.; Oliveira, Arno H. de

    2009-01-01

    Human beings are exposed to ionizing radiation from many natural sources. Radon and its progeny have been recognized as the most important contributors to the natural radioactivity dose, accounting for about half of all human exposure to ionizing radiation. Radon ( 222 Rn) is a α-radioactive noble gas derived from the natural series of uranium (2 38 U), which occurs in a wide concentration range in all geological materials, especially, in rocks, soils and waters. By diffusion and convection, radon migrates from the rocks and soils to atmosphere and through fissures, pipes and holes it may enter the dwellings and other buildings. Another important radon source in dwellings is its emanation from the construction material. The radon progeny concentration in dwellings has been receiving considerable global attention due to its potential effect in causing lung cancer if it deposited in upper respiratory tract when inhaled. This paper presents radon concentration distribution in dwellings in Metropolitan Region of Belo Horizonte - RMBH. The effective dose estimate is also presented for the RMBH inhabitants. The geological settings of the area are Archean rocks of Granitic Gnaissic Complex and of metasediments sequences of the great Precambrian unit of the Iron Quadrangle of Minas Gerais, Brazil. Radon concentration measurements were carried out with continuous detector AlphaGUARD PQ200PRO (Genitron), in passive mode and with passive detectors E-PERM R Eletret Ion Chamber-EIC. The radon progeny concentration was carried out with a solid state alpha spectroscope, the DOSEman PRO (Sarad). It was found an indoor radon concentration varying in a large range from 18.5 to 2671.4 Bq/m -3 , with an average value of 148.0 Bqm -3 and geometric mean equal to 128.2 Bqm -3 . The variable results are due mainly to region geological factors and building material composition of dwellings. The equilibrium factor between radon and its progeny were determined in dwellings, as 0.3 in

  12. Polarization-induced Zener tunnel diodes in GaN/InGaN/GaN heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xiaodong; Li, Wenjun; Islam, S. M.; Pourang, Kasra; Fay, Patrick [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Xing, Huili; Jena, Debdeep, E-mail: djena@cornell.edu [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Departments of ECE and MSE, Cornell University, Ithaca, New York 14853 (United States)

    2015-10-19

    By the insertion of thin In{sub x}Ga{sub 1−x}N layers into Nitrogen-polar GaN p-n junctions, polarization-induced Zener tunnel junctions are studied. The reverse-bias interband Zener tunneling current is found to be weakly temperature dependent, as opposed to the strongly temperature-dependent forward bias current. This indicates tunneling as the primary reverse-bias current transport mechanism. The Indium composition in the InGaN layer is systematically varied to demonstrate the increase in the interband tunneling current. Comparing the experimentally measured tunneling currents to a model helps identify the specific challenges in potentially taking such junctions towards nitride-based polarization-induced tunneling field-effect transistors.

  13. Temperature coefficients for GaInP/GaAs/GaInNAsSb solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Aho, Arto; Isoaho, Riku; Tukiainen, Antti; Polojärvi, Ville; Aho, Timo; Raappana, Marianna; Guina, Mircea [Optoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FIN-33101 Tampere (Finland)

    2015-09-28

    We report the temperature coefficients for MBE-grown GaInP/GaAs/GaInNAsSb multijunction solar cells and the corresponding single junction sub-cells. Temperature-dependent current-voltage measurements were carried out using a solar simulator equipped with a 1000 W Xenon lamp and a three-band AM1.5D simulator. The triple-junction cell exhibited an efficiency of 31% at AM1.5G illumination and an efficiency of 37–39% at 70x real sun concentration. The external quantum efficiency was also measured at different temperatures. The temperature coefficients up to 80°C, for the open circuit voltage, the short circuit current density, and the conversion efficiency were determined to be −7.5 mV/°C, 0.040 mA/cm{sup 2}/°C, and −0.09%/°C, respectively.

  14. Polarization-induced Zener tunnel diodes in GaN/InGaN/GaN heterojunctions

    International Nuclear Information System (INIS)

    Yan, Xiaodong; Li, Wenjun; Islam, S. M.; Pourang, Kasra; Fay, Patrick; Xing, Huili; Jena, Debdeep

    2015-01-01

    By the insertion of thin In x Ga 1−x N layers into Nitrogen-polar GaN p-n junctions, polarization-induced Zener tunnel junctions are studied. The reverse-bias interband Zener tunneling current is found to be weakly temperature dependent, as opposed to the strongly temperature-dependent forward bias current. This indicates tunneling as the primary reverse-bias current transport mechanism. The Indium composition in the InGaN layer is systematically varied to demonstrate the increase in the interband tunneling current. Comparing the experimentally measured tunneling currents to a model helps identify the specific challenges in potentially taking such junctions towards nitride-based polarization-induced tunneling field-effect transistors

  15. Performance Analysis of GaN Capping Layer Thickness on GaN/AlGaN/GaN High Electron Mobility Transistors.

    Science.gov (United States)

    Sharma, N; Periasamy, C; Chaturvedi, N

    2018-07-01

    In this paper, we present an investigation of the impact of GaN capping layer and AlGaN layer thickness on the two-dimensional (2D)-electron mobility and the carrier concentration which was formed close to the AlGaN/GaN buffer layer for Al0.25Ga0.75N/GaN and GaN/Al0.25Ga0.75N/GaN heterostructures deposited on sapphire substrates. The results of our analysis clearly indicate that expanding the GaN capping layer thickness from 1 nm to 100 nm prompts an increment in the electron concentration at hetero interface. As consequence of which drain current was additionally increments with GaN cap layer thicknesses, and eventually saturates at approximately 1.85 A/mm for capping layer thickness greater than 40 nm. Interestingly, for the same structure, the 2D-electron mobility, decrease monotonically with GaN capping layer thickness, and saturate at approximately 830 cm2/Vs for capping layer thickness greater than 50 nm. A device with a GaN cap layer didn't exhibit gate leakage current. Furthermore, it was observed that the carrier concentration was first decrease 1.03 × 1019/cm3 to 6.65 × 1018/cm3 with AlGaN Layer thickness from 5 to 10 nm and after that it increases with the AlGaN layer thickness from 10 to 30 nm. The same trend was followed for electric field distributions. Electron mobility decreases monotonically with AlGaN layer thickness. Highest electron mobility 1354 cm2/Vs were recorded for the AlGaN layer thickness of 5 nm. Results obtained are in good agreement with published experimental data.

  16. Spin injection in epitaxial MnGa(111)/GaN(0001) heterostructures

    Science.gov (United States)

    Zube, Christian; Malindretos, Joerg; Watschke, Lars; Zamani, Reza R.; Disterheft, David; Ulbrich, Rainer G.; Rizzi, Angela; Iza, Michael; Keller, Stacia; DenBaars, Steven P.

    2018-01-01

    Ferromagnetic MnGa(111) layers were grown on GaN(0001) by molecular beam epitaxy. MnGa/GaN Schottky diodes with a doping level of around n = 7 × 1018 cm-3 were fabricated to achieve single step tunneling across the metal/semiconductor junction. Below the GaN layer, a thin InGaN quantum well served as optical spin detector ("spin-LED"). For electron spin injection from MnGa into GaN and subsequent spin transport through a 45 nm (70 nm) thick GaN layer, we observe a circular polarization of 0.3% (0.2%) in the electroluminescence at 80 K. Interface mixing, spin polarization losses during electrical transport in the GaN layer, and spin relaxation in the InGaN quantum well are discussed in relation with the low value of the optically detected spin polarization.

  17. Automated synthesis, characterization and biological evaluation of [{sup 68}Ga]Ga-AMBA, and the synthesis and characterization of {sup nat}Ga-AMBA and [{sup 67}Ga]Ga-AMBA

    Energy Technology Data Exchange (ETDEWEB)

    Cagnolini, Aldo; Chen Jianqing; Ramos, Kimberly; Marie Skedzielewski, Tina; Lantry, Laura E.; Nunn, Adrian D.; Swenson, Rolf E. [Ernst Felder Laboratories, Bracco Research USA Inc., 305 College Road East, Princeton, NJ 08540 (United States); Linder, Karen E., E-mail: karen.e.linder@gmail.co [Ernst Felder Laboratories, Bracco Research USA Inc., 305 College Road East, Princeton, NJ 08540 (United States)

    2010-12-15

    Ga-AMBA (Ga-DO3A-CH{sub 2}CO-G-[4-aminobenzoyl]-QWAVGHLM-NH{sub 2}) is a bombesin-like agonist with high affinity for gastrin releasing peptide receptors (GRP-R). Syntheses for {sup nat}Ga-AMBA, [{sup 67}Ga]Ga-AMBA and [{sup 68}Ga]Ga-AMBA were developed. The preparation of HPLC-purified and Sep-Pak purified [{sup 68}Ga]Ga-AMBA were fully automated, using the built-in radiodetector of the Tracerlab FX F-N synthesizer to monitor fractionated {sup 68}Ge/{sup 68}Ga generator elution and purification. The total synthesis time, including the fractional elution of the generator, was 20 min for Sep-Pak purified material and 40 min for HPLC-purified [{sup 68}Ga]Ga-AMBA. Both [{sup 67}Ga]Ga-AMBA and [{sup 177}Lu]Lu-AMBA showed comparable high affinity for GRP-R in the human prostate cancer cell line PC-3 in vitro (k{sub D}=0.46{+-}0.07; 0.44{+-}0.08 nM), high internalization (78; 77%) and low efflux from cells at 2 h (2.4{+-}0.7; 2.9{+-}1.8%). Biodistribution results in PC-3 tumor-bearing male nude mice showed comparable uptake for [{sup 177}Lu]Lu-, [{sup 111}In]In-, [{sup 67}Ga]Ga- and [{sup 68}Ga]Ga-AMBA.

  18. Capacitance properties and simulation of the AlGaN/GaN Schottky heterostructure

    International Nuclear Information System (INIS)

    Harmatha, Ladislav; Ľubica, Stuchlíková; Juraj, Racko; Juraj, Marek; Juraj, Pecháček; Peter, Benko; Michal, Nemec; Juraj, Breza

    2014-01-01

    Highlights: • Dependences of CV characteristics of the AlGaN/GaN structure on frequency and temperature variations. • Identification of electrical activity of defects by capacitance DLTS. • Simulating the properties of the GaN/Al 0.2 GaN 0.8 /GaN Schottky heterostructure. - Abstract: The paper presents the results of capacitance measurements on GaN/AlGaN/GaN Schottky heterostructures grown on an Al 2 O 3 substrate by Low-Pressure Metal–Organic Vapour-Phase Epitaxy (LP-MOVPE). Dependences of the capacitance–voltage (CV) characteristics on the frequency of the measuring signal allow analysing the properties of the 2D electron gas (2DEG) at the AlGaN/GaN heterojunction. Exact location of the hetero-interface below the surface (20 nm) was determined from the concentration profile. Temperature variations of the CV curves reveal the influence of bulk defects in GaN and of the traps at the AlGaN/GaN interface. Electrical activity of these defects was characterized by capacitance Deep Level Transient Fourier Spectroscopy (DLTFS). Experimental results of CV measurements were supported by simulating the properties of the GaN/Al 0.2 GaN 0.8 /GaN Schottky heterostructure in dependence on the influence of the concentration of donor-like traps in GaN and of the temperature upon the CV curves

  19. Iron, Oil, and Emeryville: Resource Industrialization and Metropolitan Expansion in the San Francisco Bay Area, 1850-1900

    OpenAIRE

    Lunine, Seth

    2013-01-01

    Scholars have largely overlooked the formative role of industry in both California's economic development and the San Francisco Bay Area's metropolitan expansion during the late nineteenth century. Beginning in the early 1880s, leading firms in San Francisco's specialized industries, such as the iron and chemicals sectors, dispersed to the metropolitan periphery. This process of industrial suburbanization created an integrative metropolitan economy, as well as individual suburbs. In this di...

  20. Growth of InGaN multiple quantum wells and GaN eplilayer on GaN substrate

    International Nuclear Information System (INIS)

    Lee, Sung-Nam; Paek, H.S.; Son, J.K.; Sakong, T.; Yoon, E.; Nam, O.H.; Park, Y.

    2006-01-01

    We investigated that the surface morphology of GaN epilayers was significantly affected by the surface tilt orientation of GaN substrate. Surface morphologies of GaN epilayers on GaN substrates show three types: mirror, wavy, and hillock. These surface morphologies are dependent on the surface orientation of GaN substrates. It is found that the hillock morphology of GaN epilayer was formed on the GaN substrate with surface tilt orientation less than 0.1 o . As the surface tilt angle increased to 0.35 o , the surface morphology varied from hillock to wavy morphology. Above a surface tilt angle of 0.4 o , surface morphology changed to the mirror-like type morphology. Additionally, these three types of GaN surface morphology also affected the optical quality of GaN epilayers as well as InGaN multiple quantum wells on GaN substrates by non-uniform In incorporation on the different surface morphologies of GaN epilayers

  1. Carrier confinement effects of InxGa1-xN/GaN multi quantum disks with GaN surface barriers grown in GaN nanorods

    Science.gov (United States)

    Park, Youngsin; Chan, Christopher C. S.; Taylor, Robert A.; Kim, Nammee; Jo, Yongcheol; Lee, Seung W.; Yang, Woochul; Im, Hyunsik

    2018-04-01

    Structural and optical properties of InxGa1-xN/GaN multi quantum disks (QDisks) grown on GaN nanorods by molecular beam epitaxy have been investigated by transmission electron microscopy and micro-photoluminescence (PL) spectroscopy. Two types of InGaN QDisks were grown: a pseudo-3D confined InGaN pillar-type QDisks embedded in GaN nanorods; and QDisks in flanged cone type GaN nanorods. The PL emission peak and excitation dependent PL behavior of the pillar-type Qdisks differ greatly from those of the flanged cone type QDisks. Time resolved PL was carried out to probe the differences in charge carrier dynamics. The results suggest that by constraining the formation of InGaN QDisks within the centre of the nanorod, carriers are restricted from migrating to the surface, decreasing the surface recombination at high carrier densities.

  2. Small-town migration to metropolitan centres: a case in Peninsular Malaysia.

    Science.gov (United States)

    Lee Boon Thong

    1979-12-01

    In Malaysia small towns are an important source of population gowth in metropolitan areas. To provide empirical evidence of the magnitude and roles of small urban centers as complementary sources of population growth in metropolitan areas, a small survey was conducted in 10 small towns in the State of Selangor. Criteria for the selection of these towns include a fair geographical spread over the State, and each area must characteristically possess a dominant urban center. The questionnaires were directed to the heads of 300 households with the intention of investigating the socioeconomic background of the households and the magnitude and characteristics of those members of the households who have migrated elsewhere. The total number of outmigrants from each area varied from 27-57, giving an overall average figure of 1.53 outmigrants/household. About 77% of the outmigrants had moved to the metropolitan centers. As the majority of the metropolitan migrants were more attracted to Kuala Lumpur, Klang, and Petaling Jaya, it may be assumed that the total outmigrants from small towns as derived would have consitituted about 39% of the population in the Klang Valley region. Based on this estimate, the role of small towns in metropolitan population growth is important. In the survey conducted, 2 broad categories of movements were involved: "economic movers," i.e., those who migrated to work or to establish businesses in the metropolitan areas; and "noneconomic movers," i.e., those who moved to continue their studies or to follow their spouses, and so forth. The economic mover stream made up 71% of the total metropolitan migrants. 2 variables--marital status and sex--were significantly related to the economic or noneconomic nature of the metropolitan migrants. The movement of males tended to be associated with economic motives whereas noneconomic reasons for movement tended to be the case among females migrants. The most important occupational group of the economically

  3. FAA Air Traffic Activity. Fiscal Year 1991

    Science.gov (United States)

    1991-01-01

    MGR) GA 448 0 0 448 0 THOMASVILLE MUNICIPAL ............................................ (TVI) GA 963 0 0 963 0 TIFTON ...listed below for ordering purposes. ATLANTA, GA KANSAS CITY, MO 275 Peachtree Street. NE, Room 100, P.O. Box 56445, Atlanta, GA 120 Bannister Mail, 5600...CA L 3 660680 TORRANCE MUNICIPAL ................................... CA L 83 210157 ATLANTA INTERNATIONAL ............................. GA

  4. Comparative Analysis of User-Generated Online Yelp Reviews for Periodontal Practices in Multiple Metropolitan Markets.

    Science.gov (United States)

    Holtzclaw, Dan J

    2017-02-01

    Previously published research for a single metropolitan market (Austin, Texas) found that periodontists fare poorly on the Yelp website for nearly all measured metrics, including average star ratings, number of reviews, review removal rate, and evaluations by "elite" Yelp users. The purpose of the current study is to confirm or refute these findings by expanding datasets to additional metropolitan markets of various sizes and geographic locations. A total of 6,559 Yelp reviews were examined for general dentists, endodontists, pediatric dentists, oral surgeons, orthodontists, and periodontists in small (Austin, Texas), medium (Seattle, Washington), and large (New York City, New York) metropolitan markets. Numerous review characteristics were evaluated, including: 1) total number of reviews; 2) average star rating; 3) review filtering rate; and 4) number of reviews by Yelp members with elite status. Results were compared in multiple ways to determine whether statistically significant differences existed. In all metropolitan markets, periodontists were outperformed by all other dental specialties for all measured Yelp metrics in this study. Intermetropolitan comparisons of periodontal practices showed no statistically significant differences. Periodontists were outperformed consistently by all other dental specialties in every measured metric on the Yelp website. These results were consistent and repeated in all three metropolitan markets evaluated in this study. Poor performance of periodontists on Yelp may be related to the age profile of patients in the typical periodontal practice. This may result in inadvertently biased filtering of periodontal reviews and subsequently poor performance in multiple other categories.

  5. InGaN/GaN Nanowire LEDs and Lasers

    KAUST Repository

    Zhao, Chao

    2016-01-01

    The large specific surface, and the associated high density of surface states was found to limit the light output power and quantum efficiency of nanowire-array devices, despite their potential for addressing the “green-gap” and efficiency-droop issues. The phonon and carrier confinement in nanowires also led to junction heating, and reduced heat dissipation. In this paper, we will present our studies on effective surface states passivation in InGaN/GaN quantum-disks (Qdisks)-in-nanowire light-emitting diodes (LEDs) and lasers grown on silicon (Si), as well as our recent work on nanowires LEDs grown on bulk-metal, a non-conventional substrate.

  6. AlGaAs/InGaAs/AlGaAs double pulse doped pseudomorphic high electron mobility transistor structures on InGaAs substrates

    Science.gov (United States)

    Hoke, W. E.; Lyman, P. S.; Mosca, J. J.; McTaggart, R. A.; Lemonias, P. J.; Beaudoin, R. M.; Torabi, A.; Bonner, W. A.; Lent, B.; Chou, L.-J.; Hsieh, K. C.

    1997-10-01

    Double pulse doped AlGaAs/InGaAs/AlGaAs pseudomorphic high electron mobility transistor (PHEMT) structures have been grown on InxGa1-xAs (x=0.025-0.07) substrates using molecular beam epitaxy. A strain compensated, AlGaInAs/GaAs superlattice was used for improved resistivity and breakdown. Excellent electrical and optical properties were obtained for 110-Å-thick InGaAs channel layers with indium concentrations up to 31%. A room temperature mobility of 6860 cm2/V s with 77 K sheet density of 4.0×1012cm-2 was achieved. The InGaAs channel photoluminescence intensity was equivalent to an analogous structure on a GaAs substrate. To reduce strain PHEMT structures with a composite InGaP/AlGaAs Schottky layer were also grown. The structures also exhibited excellent electrical and optical properties. Transmission electron micrographs showed planar channel interfaces for highly strained In0.30Ga0.70As channel layers.

  7. Spectroscopic ellipsometry analysis of InGaN/GaN and AlGaN/GaN heterostructures using a parametric dielectric function model

    International Nuclear Information System (INIS)

    Wagner, J.; Ramakrishnan, A.; Obloh, H.; Kunzer, M.; Koehler, K.; Johs, B.

    2000-01-01

    Spectroscopic ellipsometry (SE) has been used for the characterization of AlGaN/GaN and InGaN/GaN heterostructures. The resulting pseudodielectric function spectra were analyzed using a multilayer approach, describing the dielectric functions of the individual layers by a parametric oscillator model. From this analysis, the dielectric function spectra of GaN, Al x Ga 1-x N (x le 0.16), and In 0.13 Ga 0.87 N were deduced. Further, the dependence of the Al x Ga 1-x N band gap energy on the Al mole fraction was derived and compared with photoluminescence data recorded on the same material. The SE band gap data are compatible with a bowing parameter close to 1 eV for the composition dependence of the Al x Ga 1-x N gap energy. Finally, the parametric dielectric functions have been used to model the pseudodielectric function spectrum of a complete GaN/AlGaN/InGaN LED structure

  8. Bipolar characteristics of AlGaN/AlN/GaN/AlGaN double heterojunction structure with AlGaN as buffer layer

    International Nuclear Information System (INIS)

    Peng, Enchao; Wang, Xiaoliang; Xiao, Hongling; Wang, Cuimei; Yin, Haibo; Chen, Hong; Feng, Chun; Jiang, Lijuan; Hou, Xun; Wang, Zhanguo

    2013-01-01

    Highlights: •2DEG and 2DHG coexist in the AlGaN/AlN/GaN/AlGaN DH-structure. •The sheet densities of 2DEG and 2DHG vary with buffer Al content and GaN thickness. •The conditions for the disappearance of 2DHG are discussed. •Increasing buffer Al content provides better electron confinement. •Dislocation scattering is reduced in the DH-structure. -- Abstract: This is a theoretical study of AlGaN/AlN/GaN/AlGaN double heterojunction (DH) structure with AlGaN as buffer layer. Our calculation shows that as the buffer Al content increases, though two-dimensional electron gas (2DEG) sheet density decreases, the channel back-barrier caused by polarization-induced electric field in GaN provides better electron confinement. And under certain conditions the DH-structure shows bipolar characteristics, with an additional two-dimensional hole gas (2DHG) formed at GaN/AlGaN interface. The influence of the buffer Al content and GaN channel thickness on the 2DEG and 2DHG sheet densities are investigated, and the conditions for the disappearance of 2DHG are discussed. Also, the mobility inhibited by dislocation scattering is enhanced in DH-structure due to the enhancement of screening effect of the 2DEG

  9. Impact of the 2001 Tohoku-oki earthquake to Tokyo Metropolitan area observed by the Metropolitan Seismic Observation network (MeSO-net)

    Science.gov (United States)

    Hirata, N.; Hayashi, H.; Nakagawa, S.; Sakai, S.; Honda, R.; Kasahara, K.; Obara, K.; Aketagawa, T.; Kimura, H.; Sato, H.; Okaya, D. A.

    2011-12-01

    The March 11, 2011 Tohoku-oki earthquake brought a great impact to the Tokyo metropolitan area in both seismological aspect and seismic risk management although Tokyo is located 340 km from the epicenter. The event generated very strong ground motion even in the metropolitan area and resulted severe requifaction in many places of Kanto district. National and local governments have started to discuss counter measurement for possible seismic risks in the area taking account for what they learned from the Tohoku-oki event which is much larger than ever experienced in Japan Risk mitigation strategy for the next greater earthquake caused by the Philippine Sea plate (PSP) subducting beneath the Tokyo metropolitan area is of major concern because it caused past mega-thrust earthquakes, such as the 1703 Genroku earthquake (M8.0) and the 1923 Kanto earthquake (M7.9). An M7 or greater (M7+) earthquake in this area at present has high potential to produce devastating loss of life and property with even greater global economic repercussions. The Central Disaster Management Council of Japan estimates that an M7+ earthquake will cause 11,000 fatalities and 112 trillion yen (about 1 trillion US$) economic loss. In order to mitigate disaster for greater Tokyo, the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan Area was launched in collaboration with scientists, engineers, and social-scientists in nationwide institutions. We will discuss the main results that are obtained in the respective fields which have been integrated to improve information on the strategy assessment for seismic risk mitigation in the Tokyo metropolitan area; the project has been much improved after the Tohoku event. In order to image seismic structure beneath the Metropolitan Tokyo area we have developed Metropolitan Seismic Observation network (MeSO-net; Hirata et al., 2009). We have installed 296 seismic stations every few km (Kasahara et al., 2011). We conducted seismic

  10. Gold free contacts to AlGaN/GaN heterostructures

    NARCIS (Netherlands)

    Hajlasz, Marcin

    2018-01-01

    Transistors and diodes based on AlGaN/GaN are suitable candidates for high-voltage and high-speed electronics due to the GaN material properties such as wide bandgap, large breakdown field, high electron saturation velocity and good thermal conductivity. When thin AlGaN layer is grown epitaxially on

  11. Gas sensing with AlGaN/GaN 2DEG channels

    NARCIS (Netherlands)

    Offermans, P.; Vitushinsky, R.; Crego-Calama, M.; Brongersma, S.H.

    2011-01-01

    AlGaN/GaN shows great promise as a generic platform for (bio-)chemical sensing because of its robustness and intrinsic sensitivity to surface charge or dipoles. Here, we employ the two-dimensional electron gas (2DEG) formed at the interface of AlGaN/GaN layers grown on Si substrates for the

  12. Exploring the radiosynthesis and in vitro characteristics of [68Ga]Ga-DOTA-Siglec-9

    DEFF Research Database (Denmark)

    Jensen, Svend Borup; Käkelä, Meeri; Jødal, Lars

    2017-01-01

    (Siglec-9) "CARLSLSWRGLTLCPSK" bind to VAP-1 and hence makes the radioactive analogues of this compound ([68 Ga]Ga-DOTA-Siglec-9) interesting as a non-invasive visualizing marker of inflammation. Three different approaches to the radiosynthesis of [68 Ga]Ga-DOTA-Siglec-9 are presented and compared...

  13. Characterization of GaN/AlGaN epitaxial layers grown

    Indian Academy of Sciences (India)

    GaN and AlGaN epitaxial layers are grown by a metalorganic chemical vapour deposition (MOCVD) system. The crystalline quality of these epitaxially grown layers is studied by different characterization techniques. PL measurements indicate band edge emission peak at 363.8 nm and 312 nm for GaN and AlGaN layers ...

  14. Exciton binding energy in wurtzite InGaN/GaN quantum wells

    International Nuclear Information System (INIS)

    Park, Seoung-Hwan; Kim, Jong-Jae; Kim, Hwa-Min

    2004-01-01

    The internal field and carrier density effects on the exciton binding energies in wurtzite (WZ) InGaN/GaN quantum-well (QW) structures are investigated using the multiband effective-mass theory, and are compared with those obtained from the at-band model and with those of GaN/AlGaN QW structures. The exciton binding energy is significantly reduced with increasing sheet carrier density, suggesting that excitons are nearly bleached at densities around 10 12 cm -2 for both InGaN/GaN and GaN/AlGaN QW structures. With the inclusion of the internal field, the exciton binding energy is substantialy reduced compared to that of the at-band model in the investigated region of the wells. This can be explained by a decrease in the momentum matrix element and an increase in the inverse screening length due to the internal field. The exciton binding energy of the InGaN/GaN structure is smaller than that of the GaN/AlGaN structure because InGaN/GaN structures have a smaller momentum matrix element and a larger inverse screening length than GaN/AlGaN structures.

  15. InGaAs and GaAsSb strain reducing layers covering InAs/GaAs quantum dots

    Czech Academy of Sciences Publication Activity Database

    Hospodková, Alice; Hulicius, Eduard; Pangrác, Jiří; Oswald, Jiří; Vyskočil, Jan; Kuldová, Karla; Šimeček, Tomislav; Hazdra, P.; Caha, O.

    2010-01-01

    Roč. 312, č. 8 (2010), 1383-1387 ISSN 0022-0248 R&D Projects: GA AV ČR IAA100100719; GA ČR GA202/09/0676; GA MŠk LC510 Institutional research plan: CEZ:AV0Z10100521 Keywords : low dimensional structures * photoluminescence * low-pressure MOVPE * InAs/GaAs quantum dots * semiconducting III/V materials Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.737, year: 2010

  16. AlGaN/GaN High Electron Mobility Transistors with Multi-MgxNy/GaN Buffer

    OpenAIRE

    Chang, P. C.; Lee, K. H.; Wang, Z. H.; Chang, S. J.

    2014-01-01

    We report the fabrication of AlGaN/GaN high electron mobility transistors with multi-MgxNy/GaN buffer. Compared with conventional HEMT devices with a low-temperature GaN buffer, smaller gate and source-drain leakage current could be achieved with this new buffer design. Consequently, the electron mobility was larger for the proposed device due to the reduction of defect density and the corresponding improvement of crystalline quality as result of using the multi-MgxNy/GaN buffer.

  17. AlGaN/GaN High Electron Mobility Transistors with Multi-MgxNy/GaN Buffer

    Directory of Open Access Journals (Sweden)

    P. C. Chang

    2014-01-01

    Full Text Available We report the fabrication of AlGaN/GaN high electron mobility transistors with multi-MgxNy/GaN buffer. Compared with conventional HEMT devices with a low-temperature GaN buffer, smaller gate and source-drain leakage current could be achieved with this new buffer design. Consequently, the electron mobility was larger for the proposed device due to the reduction of defect density and the corresponding improvement of crystalline quality as result of using the multi-MgxNy/GaN buffer.

  18. A highly attennuative zone beneath the Tokyo Metropolitan area.

    Science.gov (United States)

    Panayotopoulos, Y.; Hirata, N.; Sakai, S.; Nakagawa, S.; Kasahara, K.

    2014-12-01

    The intensities of seismic waves observed at the dense seismic array of the Tokyo Metropolitan Seismic Observation network (MeSO-net) inside the Kanto basin, display unusual distribution patterns. In several occasions, the highest intensities are not observed in the area above an earthquakes hypocenter but appear sifted more than 20 km away. In order to understand the source of this unusual intensity distribution pattern, it is crucial to understand how the waves attenuate before they reach the surface. The attenuation of seismic waves along their path is represented by the t∗ attenuation operator that can be obtained by fitting the observed seismic wave spectrum to a theoretical spectrum using an ω2 model. In order to create a high quality dataset, only 1449 earthquakes that are recorded with intensity greater than 0 in the Japan Meteorological Agency (JMA) intensity scale are selected from the JMA unified earthquake list from April 1st 2008 to October 2nd 2013. A grid search method is applied to determine the t∗ values by matching the observed and theoretical spectra. The t∗ data where then inverted to estimate a 3D Q structure with grid points set at a 10 km spacing. We implemented the 3D velocity model estimated by Nakagawa et al., 2012 and in addition we set the initial Q values at 100 for the 0 km grids and to 400 for the grids below them. The obtained model suggests average Q values of 50˜100 inside the Kanto basin. Furthermore, a low Q zone is observed in the area where the Philippine Sea plate meets the upper part of the Pacific sea plate. This area is located at approximately 40 km depth, beneath the north-east Tokyo and west Chiba prefectures and is represented by Q values Earthquakes occurring on the Pacific plate pass through this low Q area inside the Philippine sea plate and are attenuated significantly. The estimated attenuation distribution at the MeSO-net station for these earthquakes implementing our 3D Q model greatly coincides with the

  19. Forecasting drug utilization and expenditure in a metropolitan health region

    Directory of Open Access Journals (Sweden)

    Korkmaz Seher

    2010-05-01

    Full Text Available Abstract Background New pharmacological therapies are challenging the healthcare systems, and there is an increasing need to assess their therapeutic value in relation to existing alternatives as well as their potential budget impact. Consequently, new models to introduce drugs in healthcare are urgently needed. In the metropolitan health region of Stockholm, Sweden, a model has been developed including early warning (horizon scanning, forecasting of drug utilization and expenditure, critical drug evaluation as well as structured programs for the introduction and follow-up of new drugs. The aim of this paper is to present the forecasting model and the predicted growth in all therapeutic areas in 2010 and 2011. Methods Linear regression analysis was applied to aggregate sales data on hospital sales and dispensed drugs in ambulatory care, including both reimbursed expenditure and patient co-payment. The linear regression was applied on each pharmacological group based on four observations 2006-2009, and the crude predictions estimated for the coming two years 2010-2011. The crude predictions were then adjusted for factors likely to increase or decrease future utilization and expenditure, such as patent expiries, new drugs to be launched or new guidelines from national bodies or the regional Drug and Therapeutics Committee. The assessment included a close collaboration with clinical, clinical pharmacological and pharmaceutical experts from the regional Drug and Therapeutics Committee. Results The annual increase in total expenditure for prescription and hospital drugs was predicted to be 2.0% in 2010 and 4.0% in 2011. Expenditures will increase in most therapeutic areas, but most predominantly for antineoplastic and immune modulating agents as well as drugs for the nervous system, infectious diseases, and blood and blood-forming organs. Conclusions The utilisation and expenditure of drugs is difficult to forecast due to uncertainties about the rate

  20. Factors Influencing Patronage Of Medical Tourism In Metropolitan Lagos Nigeria

    Directory of Open Access Journals (Sweden)

    Omisore

    2015-08-01

    Full Text Available Since medical tourism attract patient from various origin to seek medical services at different destinations it is paramount to consider the factors that motivate patrons decision on medical tourism. Hence this study assesses the factors influencing patronage of medical tourism in Lagos metropolis Nigeria. Lagos State is situated in the southwestern corner of Nigeria it lies within Latitudes 62N to 64N of the Equator and Longitudes 245E to 420E of the Greenwich meridian. Metropolitan Lagos is a statistical division and not an administrative unit it extends over 16 of the 20 LGAs of Lagos State it contains 88 of the population of Lagos State and includes semi-rural areas. Data were collected from primary source. Primary data collection was carried out through the use of structured questionnaire. Systematic sampling technique was employed to select 15 specialized private hospitals and 14 Public hospitals in the study area resulting to a sample size of 29 hospitals. Ten 10 patrons were contacted in each of the selected hospitals consequently 290 patrons were sampled. The study revealed three factors influencing patronage of medical tourism in the study area to be service related economic and facilities. These were further established by factor analysis result which combine service related economic factor as factor one with 29.5 variance explained and Eigen value of 5.605 Facility factor as factor two with 28.6 variance explained and Eigen value of 5.435 Service related factor as factor three with 14.7 variance explained and Eigen value of 2.788 and Economic factor as factor four with 9.2 variance explained and Eigen value of 1.754. The relevant authority in charge of health facilities in the study area would have to employ adequate manpower in-terms of doctors and other healthcare personnel across the public hospital while also regulating the scale of charges of the registered private hospitals in the study area. There is need to improve upon the

  1. ECV profiling of GaAs and GaN HEMT heterostructures

    Science.gov (United States)

    Yakovlev, G.; Zubkov, V.

    2018-03-01

    AlGaAs/InGaAs/GaAs and AlGaN/GaN HEMT heterostructures were investigated by means of electrochemical capacitance-voltage technique. A set of test structures were fabricated using various doping techniques: standard doping, δ-doping GaAs pHEMT and nondoping GaN HEMT. The concentration profiles of free charge carriers across the samples were experimentally obtained. The QW filling was analyzed and compared for different mechanisms of emitter doping and 2DEG origins.

  2. Temperature Dependence of the Energy Band Diagram of AlGaN/GaN Heterostructure

    Directory of Open Access Journals (Sweden)

    Yanli Liu

    2018-01-01

    Full Text Available Temperature dependence of the energy band diagram of AlGaN/GaN heterostructure was investigated by theoretical calculation and experiment. Through solving Schrodinger and Poisson equations self-consistently by using the Silvaco Atlas software, the energy band diagram with varying temperature was calculated. The results indicate that the conduction band offset of AlGaN/GaN heterostructure decreases with increasing temperature in the range of 7 K to 200 K, which means that the depth of quantum well at AlGaN/GaN interface becomes shallower and the confinement of that on two-dimensional electron gas reduces. The theoretical calculation results are verified by the investigation of temperature dependent photoluminescence of AlGaN/GaN heterostructure. This work provides important theoretical and experimental basis for the performance degradation of AlGaN/GaN HEMT with increasing temperature.

  3. Study of GaN nanorods converted from β-Ga2O3

    Science.gov (United States)

    Li, Yuewen; Xiong, Zening; Zhang, Dongdong; Xiu, Xiangqian; Liu, Duo; Wang, Shuang; Hua, Xuemei; Xie, Zili; Tao, Tao; Liu, Bin; Chen, Peng; Zhang, Rong; Zheng, Youdou

    2018-05-01

    We report here high-quality β-Ga2O3 nanorods (NRs) grown on sapphire substrates by hydrothermal method. Ammoniating the β-Ga2O3 NRs results in strain-free wurtzite gallium nitride (GaN) NRs. It was shown by XRD and Raman spectroscopy that β-Ga2O3 was partially converted to GaN/β-Ga2O3 at 1000 °C and then completely converted to GaN NRs at 1050 °C, as confirmed by high-resolution transmission electron microscopy (HRTEM). There is no band-edge emission of β-Ga2O3 in the cathodoluminescence spectrum, and only a deep-level broad emission observed at 3.68-3.73 eV. The band edge emission (3.39 eV) of GaN NRs converted from β-Ga2O3 can also be observed.

  4. Ohmic contacts to n+-GaN capped AlGaN/AlN/GaN high electron mobility transistors

    International Nuclear Information System (INIS)

    Wang Liang; Mohammed, Fitih M.; Ofuonye, Benedict; Adesida, Ilesanmi

    2007-01-01

    Investigations of Ti/Al/Mo/Au Ohmic contact formation, premetallization plasma treatment effects, and interfacial reactions for n + -GaN capped AlGaN/AlN/GaN heterostructures are presented. Ti thickness played an important role in determining contact performance. Transmission electron microscopy studies confirmed that thick Ti layer was necessary to fully consume the GaN cap and the top of AlGaN to enable a higher tunneling current flow. A direct correlation of plasma treatment conditions with I-V linearity, current level, and contact performance was established. The plasma-affected region is believed to extend over 20 nm into the AlGaN and GaN

  5. Durability testing of the high-capacity GA-4/GA-9 trailer

    International Nuclear Information System (INIS)

    Zimmer, A.; Lyon, T.

    1995-01-01

    GA designed trailers to transport the GA-4 and GA-9 LWT from-reactor spent nuclear fuel shipping casks. GA designed and fabricated the GA-9 trailer to ANSI N14.30 requirements and is now performing a durability test at the AlliedSignal Automotive Proving Grounds. The trailer, simulated cask and tractor. The test program objective is to evaluate and improve, as necessary, the trailer's durability, reliability and performance

  6. Epitaphios of Jovan, the Metropolitan of Skopje, in the treasury of the Hilandar monastery

    Directory of Open Access Journals (Sweden)

    Radovanović Janko

    2006-01-01

    Full Text Available The epitaphios of Jovan, the Metropolitan of Skopje, was created between 1346 and 1348. It is unique for its beauty and iconographic program and, at the same time, it is the oldest of the epitaphia preserved in our country. The epitaphios was worn in the course of Holy Liturgy, during the Great Entrance in the cathedral churches and the major monasteries. Metropolitan Jovan presented the epitaphios as a gift to Christ 'my life-giver.' Depicted on its central field is the Epitaphios Threnos (Lamentation at the Tomb. Added around it, at a later time it seems, are bands representing the fourteen scenes of Great Feasts and the officiating Church Fathers, in embroidery. Holy Liturgy is served by the greatest fathers and teachers of the Church and Metropolitan Jovan.

  7. Analysing contemporary metropolitan spatial plans in Europe through their institutional context, instrumental content and planning process

    DEFF Research Database (Denmark)

    Elinbaum, Pablo; Galland, Daniel

    2016-01-01

    This article sets out to propose and apply a qualitative framework for thinking about how to analyze and compare metropolitan spatial plans in a milieu of divergent spatial planning traditions and discretionary planning practices. In doing so, the article reviews and develops an understanding...... concerning the institutional context, instrumental content and planning processes associated with four contemporary metropolitan spatial plans in Europe, namely London, Copenhagen, Paris and Barcelona. Through the results of a multiple case study and a subsequent cross comparative analysis, the article...... stresses that contemporary metropolitan spatial plans tend to merge characteristics associated with project-based and strategy-based spatial plans, thus contrasting with the typical land-use character of municipal plans and the often strategic, growth-oriented pursuit of regional plans in Europe...

  8. Potential for air quality improvement in the Tokyo metropolitan area from use of hydrogen fuel

    International Nuclear Information System (INIS)

    Kruger, Paul; Murdock, Mork

    1998-01-01

    A revised estimation has been made of the local air quality improvement that can be achieved in Tokyo as a byproduct of a word-wide hydrogen energy economy based on global reduction of CO2 emission from fossil fuels. The study for the WE-NET Project in Japan examined the potential for reduction in nitrogen oxide emission with hydrogen fuel in the Tokyo metropolitan area where sufficient data exist on trends in population, vehicle registrations, traffic activity, and exhaust emissions. A dynamic model was developed to extrapolate the trends in these data to estimate future NOx emission rates in comparison to regulatory scenarios based on policy and technical decisions of the Tokyo Metropolitan Government for improvement of air quality in the metropolitan area. The results of the model show significant potential for reduction of NOx emission by the year 2020 with a concomitant reduction in mean roadside NOx concentration. (author)

  9. Regional differences in commuting activities of inhabitants in the Tokyo metropolitan suburb

    Directory of Open Access Journals (Sweden)

    Masaki Kawase

    2004-12-01

    Full Text Available The purpose of this study is to elucidate gender differences and regional differences of co-mmuting activities by inhabitants in Japanese metropolitan suburbs. I found the different parts by districts in the metropolitan suburb. Regional factors cause gender differences in commuting activities and result in regional differences: In residential areas, inhabitants who work in metropolitan centers occupy much of the population. In older built-up areas, there are many “local” persons. In rural areas, motorization is progressing because access to rail-roads has been inconvenient. These regional factors influence the behavioral characteristics of commuting by married men, married women, never married men and never married women.

  10. Intra-metropolitan inequalities in Rio de Janeiro and the Guanabara Bay cleaning programme

    DEFF Research Database (Denmark)

    Ribeiro, Gustavo; Silva, Victor

    2005-01-01

    This paper investigates the impacts of the Guanabara Bay Cleaning Programme (GBCP) on the Rio de Janeiro urban development process. Based on the magnitude of the budget of the programme (HOW MUCH?) and its relevance to the improvement of the life quality of urban dwellers, the main discussion...... of this paper focuses on the role of GBCP in the context of the Rio de Janeiro urban trends and intra-metropolitan inequality dynamics. In studying the impact of the GBCP, we present: (a) a description of the GBCP intervention process and its goals, (b) a spatial analysis of the Rio de Janeiro Metropolitan Area...... the role of the GBCP implementation in the spatial distribution of these patterns throughout these 10 years. The conclusion builds on an analysis of the GBCP role in the current urban development process of the Rio de Janeiro Metropolitan Area, identifying its influences on the dynamics of intra...

  11. Modeling and optimization of a double-well double-barrier GaN/AlGaN/GaN/AlGaN resonant tunneling diode

    Science.gov (United States)

    Liu, Yang; Gao, Bo; Gong, Min; Shi, Ruiying

    2017-06-01

    The influence of a GaN layer as a sub-quantum well for an AlGaN/GaN/AlGaN double barrier resonant tunneling diode (RTD) on device performance has been investigated by means of numerical simulation. The introduction of the GaN layer as the sub-quantum well turns the dominant transport mechanism of RTD from the 3D-2D model to the 2D-2D model and increases the energy difference between tunneling energy levels. It can also lower the effective height of the emitter barrier. Consequently, the peak current and peak-to-valley current difference of RTD have been increased. The optimal GaN sub-quantum well parameters are found through analyzing the electrical performance, energy band, and transmission coefficient of RTD with different widths and depths of the GaN sub-quantum well. The most pronounced electrical parameters, a peak current density of 5800 KA/cm2, a peak-to-valley current difference of 1.466 A, and a peak-to-valley current ratio of 6.35, could be achieved by designing RTD with the active region structure of GaN/Al0.2Ga0.8 N/GaN/Al0.2Ga0.8 N (3 nm/1.5 nm/1.5 nm/1.5 nm).

  12. Photoluminescence study of the nitrogen content effect on GaAs/GaAs1-xNx/GaAs/AlGaAs: (Si) quantum well

    International Nuclear Information System (INIS)

    Hamdouni, A.; Bousbih, F.; Ben bouzid, S.; Aloulou, S.; Harmand, J.C.; Chtourou, R.

    2008-01-01

    We study the effect of nitrogen content in modulation-doped GaAs/GaAs 1-x N x /GaAs/GaAlAs:(Si) quantum well using low-temperature photoluminescence spectroscopy. The samples were grown on GaAs (001) substrates by molecular-beam epitaxy with different nitrogen compositions. The variation of the nitrogen composition from 0.04% to 0.32% associated to the bi-dimensional electron gas gives a new interaction mode between the nitrogen localized states and the GaAs 1-x N x /GaAs energies levels. The red-shift observed in photoluminescence spectra as function of nitrogen content has been interpreted in the frame of the band anticrossing model

  13. Stimulated emission in heterostructures with double InGaAs/GaAsSb/GaAs quantum wells, grown on GaAs and Ge/Si(001) substrates

    Energy Technology Data Exchange (ETDEWEB)

    Yablonsky, A. N., E-mail: yablonsk@ipm.sci-nnov.ru; Morozov, S. V.; Gaponova, D. M.; Aleshkin, V. Ya. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Shengurov, V. G.; Zvonkov, B. N.; Vikhrova, O. V.; Baidus’, N. V. [Lobachevsky State University of Nizhny Novgorod (Russian Federation); Krasil’nik, Z. F. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2016-11-15

    We report the observation of stimulated emission in heterostructures with double InGaAs/GaAsSb/GaAs quantum wells, grown on Si(001) substrates with the application of a relaxed Ge buffer layer. Stimulated emission is observed at 77 K under pulsed optical pumping at a wavelength of 1.11 μm, i.e., in the transparency range of bulk silicon. In similar InGaAs/GaAsSb/GaAs structures grown on GaAs substrates, room-temperature stimulated emission is observed at 1.17 μm. The results obtained are promising for integration of the structures into silicon-based optoelectronics.

  14. The Spatial Changes of Land Use in the Bucharest Metropolitan Area 1970s – 2000s

    OpenAIRE

    Gabriel Simion

    2010-01-01

    The article explore the dimension of spatial changes of land use in the Bucharest Metropolitan Area (BMA) over the past forty years. Using GIS-based land use data sets of the years 1970, 1990 and 2000, combining with statistical data, we attempted to quantify the spatial pattern of land use changes in the BMA. Our findings indicate that most significantly changes occurred with arable lands that have been reduced from 77% of total metropolitan area in 1970 to 71.3% in 2000 and in same time th...

  15. Relative Food Prices and Obesity in U.S. Metropolitan Areas: 1976-2001

    Science.gov (United States)

    Xu, Xin; Variyam, Jayachandran N.; Zhao, Zhenxiang; Chaloupka, Frank J.

    2014-01-01

    This study investigates the impact of food price on obesity, by exploring the co-occurrence of obesity growth with relative food price reduction between 1976 and 2001. Analyses control for female labor participation and metropolitan outlet densities that might affect body weight. Both the first-difference and fixed effects approaches provide consistent evidence suggesting that relative food prices have substantial impacts on obesity and such impacts were more pronounced among the low-educated. These findings imply that relative food price reductions during the time period could plausibly explain about 18% of the increase in obesity among the U.S. adults in metropolitan areas. PMID:25502888

  16. The polycentric structure of local labour markets in Mexico City's Metropolitan Area

    Directory of Open Access Journals (Sweden)

    José María Casado Izquierdo

    2012-11-01

    Full Text Available Commuting data at a district level and an algorithm designed to delineate self–contained areas show that Mexico City Metropolitan Area (MCMA was organized in 2007 in twelve local labour market areas. Although six exployment subcenters were identified, the MCMA is still clearly dominated by its Central Business District (CBD, being located the remaining five subcenters close to the CBD. Assessment of this spatial structure is not a positive one: diminishing co–location, decrease in speed and increase in commuting time and distance. Nevertheless, the rising percentage of intra–district commuting is a positive sign, even if this trend is not uniform throughout the metropolitan area.

  17. The Role of Great Cities in Romania for the Metropolitan Development

    Directory of Open Access Journals (Sweden)

    Ruxandra Irina POPESCU

    2008-02-01

    Full Text Available According to the legislation in force, in Romania there are 11 first rank cities that given their size, their importance, the level of services and the economic activity, represent attractions and are subjected to the development pressures. Still, according to the European tendencies, the urban agglomerations tend to approach this type of cooperation regardless the number of the inhabitants. Currently in Romania there are 11 great cities that have developed processes of organizing the metropolitan areas corresponding to them. Among them, two have already created metropolitan areas: Oradea (2001 and Iaşi (2004, both with the assistance of programs financed by USAID.

  18. Exarh of the Bulgarian Church metropolitan Stephen and the Moscow Patriarchy

    Directory of Open Access Journals (Sweden)

    Kostriukov Andrei

    2013-02-01

    Full Text Available The article covers the last period of church-administrative activity of the Sofia’s metropolitan Stephаn (Shokov. The author describes the testimonies of contemporaries about the character and personal qualities of this ambiguous hierarch. In 1945–1948 metropolitan Stephan was the exarch of the Bulgarian Orthodox Church and participated in the Meeting of heads and representatives of Autocephalous Orthodox Churches in 1948. The author considers the circumstances of the dismissal of metropolitan Stephаn and his exile as especially important and interesting ones. The meeting of 1948 became the critical event in the exarch’s destiny. Being the supporter of ecumenism, metropolitan Stephen tried unsuccessfully to convince Patriarch Alexis of his rightness in order not to allow the condemnation of ecumenical contacts by the Moscow meeting. However Moscow looked on ecumenism differently in those days. In Moscow the Soviet management aspired to establishment of the centre of World Orthodoxy and tried to cite the Moscow Patriarchy against Constantinople that was under the influence of the USA and the Great Britain. As the Constantinople Patriarchy approved the ecumenical movement, the Moscow Patriarchy has been forced to take of an opposite position. Therefore, the participation of the Russian Church and Churches of the socialist countries in the ecumenical movement was impossible. Metropolitan Stephan, supporting the superiority of the Moscow Patriarchy in the World Orthodoxy, supported the active participation of all Local Churches in the ecumenical movement. The communistic management applied the maximum force to the exarch in order he has not made undesirable statements at the meeting. The fate of metropolitan Stephan has been decided after this meeting. In 1948 he was fired and exiled. The Moscow Patriarchy did not exclude the possibility of moving of metropolitan Stephаn to Russia and his location in any monastery. However metropolitan

  19. Study on waste waters of metal finishing industries around Lahore metropolitan area

    International Nuclear Information System (INIS)

    Khan, Izhar-ul-Haq; Mahmood, F.; Tufail, S.; Naeem, M.

    2002-01-01

    Study was undertaken on the waste water samples from metal finishing industries of Lahore metropolitan area for the evaluation of metallic impurities. The metal finishing industry was classified into three categories i. e. medium scale, small scale and cottage scale industry. About 93 wastewater samples were collected from various metal finishing industries around Lahore metropolitan area. In addition to toxic elements like cadmium, nickel and zinc the other parameters such as hydrogen ion concentration (pH), Electrical conductivity (EC) and Total Dissolved Salts (TDS) were also determined. (author)

  20. A plume-in-grid approach to characterize air quality impacts of aircraft emissions at the Hartsfield–Jackson Atlanta International Airport

    Directory of Open Access Journals (Sweden)

    J. Rissman

    2013-09-01

    Full Text Available This study examined the impacts of aircraft emissions during the landing and takeoff cycle on PM2.5 concentrations during the months of June and July 2002 at the Hartsfield–Jackson Atlanta International Airport. Primary and secondary pollutants were modeled using the Advanced Modeling System for Transport, Emissions, Reactions, and Deposition of Atmospheric Matter (AMSTERDAM. AMSTERDAM is a modified version of the Community Multiscale Air Quality (CMAQ model that incorporates a plume-in-grid process to simulate emissions sources of interest at a finer scale than can be achieved using CMAQ's model grid. Three fundamental issues were investigated: the effects of aircraft on PM2.5 concentrations throughout northern Georgia, the differences resulting from use of AMSTERDAM's plume-in-grid process rather than a traditional CMAQ simulation, and the concentrations observed in aircraft plumes at subgrid scales. Comparison of model results with an air quality monitor located in the vicinity of the airport found that normalized mean bias ranges from −77.5% to 6.2% and normalized mean error ranges from 40.4% to 77.5%, varying by species. Aircraft influence average PM2.5 concentrations by up to 0.232 μg m−3 near the airport and by 0.001–0.007 μg m−3 throughout the Atlanta metro area. The plume-in-grid process increases concentrations of secondary PM pollutants by 0.005–0.020 μg m−3 (compared to the traditional grid-based treatment but reduces the concentration of non-reactive primary PM pollutants by up to 0.010 μg m−3, with changes concentrated near the airport. Examination of subgrid-scale results indicates that median aircraft contribution to grid cells is higher than median puff concentration in the airport's grid cell and outside of a 20 km × 20 km square area centered on the airport, while in a 12 km × 12 km square ring centered on the airport, puffs have median concentrations over an order of magnitude higher than aircraft

  1. Two new Np--Ga phases: α-NpGa2 and metastable m-NpGa2

    International Nuclear Information System (INIS)

    Giessen, B.C.; Elliott, R.O.

    1976-01-01

    Following an earlier study of metastable Np-rich Np--Ga alloys, rapidly quenched Np--Ga alloys with 63 to 80 at. pct. Ga were prepared and studied. Two new NpGa 2 phases, both with an AlB 2 type structure, were found: α-NpGa 2 , with a = 4.246A, c = 4.060A, c/a = 0.956, and m-NpGa 2 , with a = 4.412A, c = 3.642A, c/a = 0.825. While m-NpGa 2 was observed only in very fast quenched (splat cooled) samples and appears to be metastable, α-NpGa 2 is probably an equilibrium phase. In a splat cooled alloy with 75 at. pct. Ga, another, unidentified, metastable phase was observed. Crystal chemical discussions of atomic volumes, interatomic distances and axial ratios are given; the volume difference between the two forms of NpGa 2 is correlated with a valence change of Np

  2. Metropolitan Blueprints of Colonial Taxation? Lessons from Fiscal Capacity Building in British and French Africa, c. 1880-1940

    NARCIS (Netherlands)

    Frankema, E.H.P.; Waijenburg, van M.F.M.

    2014-01-01

    The historical and social science literature is divided about the importance of metropolitan blueprints of colonial rule for the development of colonial states. We exploit historical records of colonial state finances to explore the importance of metropolitan identity on the comparative development

  3. Demographic Transformation in a Policy Vacuum: The Changing Face of U.S. Metropolitan Society and Challenges for Public Schools

    Science.gov (United States)

    Mordechay, Kfir; Orfield, Gary

    2017-01-01

    Educators and policy makers must confront the race and class disparities in learning opportunities across American society. Nowhere are these disparities more acute than in the country's great metropolitan areas. As the demographic landscape continues to shift, metropolitan areas are fueling the transition to a majority-minority country. This…

  4. New aerosol particles formation in the Sao Paulo Metropolitan Area

    Science.gov (United States)

    Vela, Angel; Andrade, Maria de Fatima; Ynoue, Rita

    2016-04-01

    The Sao Paulo Metropolitan Area (SPMA), in the southeast region of Brazil, is considered a megalopolis comprised of Sao Paulo city and more 38 municipalities. The air pollutant emissions in the SPMA are related to the burning of the fuels: etanol, gasohol (gasoline with 25% ethanol) and diesel. According to CETESB (2013), the road vehicles contributed up to about 97, 87, and 80% of CO, VOCs and NOx emissions in 2012, respectively, being most of NOx associated to diesel combustion and most of CO and VOCs from gasohol and ethanol combustion. Studies conducted on ambient air pollution in the SPMA have shown that black carbon (BC) explains 21% of mass concentration of PM2.5 compared with 40% of organic carbon (OC), 20% of sulfates, and 12% of soil dust (Andrade et al., 2012). Most of the observed ambient PM2.5 mass concentration usually originates from precursors gases such as sulphur dioxide (SO2), ammonia (NH3), nitrogen oxides (NOx) and VOCs as well as through the physico-chemical processes such as the oxidation of low volatile hydrocarbons transferring to the condensed phase (McMurry et al., 2004). The Weather Research and Forecasting with Chemistry model (WRF-Chem; Grell et al. 2005), configured with three nested grid cells: 75, 15, and 3 km, is used as photochemical modeling to describe the physico-chemical processes leading to evolution of particles number and mass size distribution from a vehicular emission model developed by the IAG-USP laboratory of Atmospheric Processes and based on statistical information of vehicular activity. The spatial and temporal distributions of emissions in the finest grid cell are based on road density products compiled by the OpenStreetMap project and measurements performed inside tunnels in the SPMA, respectively. WRF-Chem simulation with coupled primary aerosol (dust and sea-salt) and biogenic emission modules and aerosol radiative effects turned on is conducted as the baseline simulation (Case_0) to evaluate the model

  5. If This Is a "Real" Housewife, Who Are All These Women Around Me?: An Examination of The Real Housewives of Atlanta and the Persistence of Historically Stereotypical Images of Black Women in Popular Reality Television.

    OpenAIRE

    Bunai, Dominique Christabel

    2014-01-01

    Stereotypical images of blacks have persisted throughout multiple forms of media for decades, with one of the most recent arenas being reality television programming. This study examines the Bravo Television network series The Real Housewives of Atlanta to consider the impact of reality television on the image of black women in America today. This increasingly popular show is the most viewed in The Real Housewives franchise, and demonstrates that black women in America do not embody any one h...

  6. Understanding the emission impacts of high-occupancy vehicle (HOV) to high-occupancy toll (HOT) lane conversions: Experience from Atlanta, Georgia.

    Science.gov (United States)

    Xu, Yanzhi Ann; Liu, Haobing; Rodgers, Michael O; Guin, Angshuman; Hunter, Michael; Sheikh, Adnan; Guensler, Randall

    2017-08-01

    Converting a congested high-occupancy vehicle (HOV) lane into a high-occupancy toll (HOT) lane is a viable option for improving travel time reliability for carpools and buses that use the managed lane. However, the emission impacts of HOV-to-HOT conversions are not well understood. The lack of emission impact quantification for HOT conversions creates a policy challenge for agencies making transportation funding choices. The goal of this paper is to evaluate the case study of before-and-after changes in vehicle emissions for the Atlanta, Georgia, I-85 HOV/HOT lane conversion project, implemented in October 2011. The analyses employed the Motor Vehicle Emission Simulator (MOVES) for project-level analysis with monitored changes in vehicle activity data collected by Georgia Tech researchers for the Georgia Department of Transportation (GDOT). During the quarterly field data collection from 2010 to 2012, more than 1.5 million license plates were observed and matched to vehicle class and age information using the vehicle registration database. The study also utilized the 20-sec, lane-specific traffic operations data from the Georgia NaviGAtor intelligent transportation system, as well as a direct feed of HOT lane usage data from the State Road and Tollway Authority (SRTA) managed lane system. As such, the analyses in this paper simultaneously assessed the impacts associated with changes in traffic volumes, on-road operating conditions, and fleet composition before and after the conversion. Both greenhouse gases and criteria pollutants were examined. A straight before-after analysis showed about 5% decrease in air pollutants and carbon dioxide (CO 2 ). However, when the before-after calendar year of analysis was held constant (to account for the effect of 1 yr of fleet turnover), mass emissions at the analysis site during peak hours increased by as much as 17%, with little change in CO 2 . Further investigation revealed that a large percentage decrease in criteria

  7. Density Functional Theory Study on Defect Feature of AsGaGaAs in Gallium Arsenide

    Directory of Open Access Journals (Sweden)

    Deming Ma

    2015-01-01

    Full Text Available We investigate the defect feature of AsGaGaAs defect in gallium arsenide clusters in detail by using first-principles calculations based on the density functional theory (DFT. Our calculations reveal that the lowest donor level of AsGaGaAs defect on the gallium arsenide crystal surface is 0.85 eV below the conduction band minimum, while the lowest donor level of the AsGaGaAs defect inside the gallium arsenide bulk is 0.83 eV below the bottom of the conduction band, consistent with gallium arsenide EL2 defect level of experimental value (Ec-0.82 eV. This suggests that AsGaGaAs defect is one of the possible gallium arsenide EL2 deep-level defects. Moreover, our results also indicate that the formation energies of internal AsGaGaAs and surface AsGaGaAs defects are predicted to be around 2.36 eV and 5.54 eV, respectively. This implies that formation of AsGaGaAs defect within the crystal is easier than that of surface. Our results offer assistance in discussing the structure of gallium arsenide deep-level defect and its effect on the material.

  8. Energetics of Mg incorporation at GaN(0001) and GaN(0001¯) surfaces

    Science.gov (United States)

    Sun, Qiang; Selloni, Annabella; Myers, T. H.; Doolittle, W. Alan

    2006-04-01

    By using density functional calculations in the generalized gradient approximation, we investigate the energetics of Mg adsorption and incorporation at GaN(0001) and GaN(0001¯) surfaces under various Ga and Mg coverage conditions as well as in presence of light or electron beam-induced electronic excitation. We find significant differences in Mg incorporation between Ga- and N-polar surfaces. Mg incorporation is easier at the Ga-polar surface, but high Mg coverages are found to cause important distortions which locally change the polarity from Ga to N polar. At the N-rich and moderately Ga-rich GaN(0001) surface, 0.25 ML of Mg substituting Ga in the top bilayer strongly reduce the surface diffusion barriers of Ga and N adatoms, in agreement with the surfactant effect observed in experiments. As the Mg coverage exceeds 0.5 ML, partial incorporation in the subsurface region (second bilayer) becomes favorable. A surface structure with 0.5 ML of incorporated Mg in the top bilayer and 0.25 ML in the second bilayer is found to be stable over a wide range of Ga chemical potential. At the Ga bilayer-terminated GaN(0001) surface, corresponding to Ga-rich conditions, configurations where Mg is incorporated in the interface region between the metallic Ga bilayer and the underlying GaN bilayer appear to be favored. At the N-polar surface, Mg is not incorporated under N-rich or moderately Ga-rich conditions, whereas incorporation in the adlayer may take place under Ga-rich conditions. In the presence of light or electron beam induced excitation, energy differences between Mg incorporated at the surface and in deeper layers are reduced so that the tendency toward surface segregation is also reduced.

  9. Internal quantum efficiency in yellow-amber light emitting AlGaN-InGaN-GaN heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, Thi Huong; Gil, Bernard; Valvin, Pierre [Laboratoire Charles Coulomb – UMR 5221, CNRS and University Montpellier, Case courier 074, 34095 Montpellier Cedex 5 (France); Damilano, Benjamin; Lekhal, Kaddour; De Mierry, Philippe [CRHEA-CNRS Centre de Recherche sur l' Hétéro-Epitaxie et ses Applications, Centre National de la Recherche Scientifique, rue Bernard Gregory, 06560 Valbonne (France)

    2015-09-21

    We determine the internal quantum efficiency of strain-balanced AlGaN-InGaN-GaN hetero-structures designed for yellow-amber light emission, by using a recent model based on the kinetics of the photoluminescence decay initiated by Iwata et al. [J. Appl. Phys. 117, 075701 (2015)]. Our results indicate that low temperature internal quantum efficiencies sit in the 50% range and we measure that adding an AlGaN layer increases the internal quantum efficiency from 50% up to 57% with respect to the GaN-InGaN case. More dramatic, it almost doubles from 2.5% up to 4.3% at room temperature.

  10. Self-diffusion in 69Ga121Sb/71Ga123Sb isotope heterostructures

    OpenAIRE

    Bracht, H.; Nicols, S. P.; Haller, E. E.; Silveira, Juan Pedro; Briones Fernández-Pola, Fernando

    2001-01-01

    Gallium and antimony self-diffusion experiments have been performed in undoped 69Ga121Sb/71Ga123Sb isotope heterostructures at temperatures between 571 and 708 °C under Sb- and Ga-rich ambients. Ga and Sb profiles measured with secondary ion mass spectrometry reveal that Ga diffuses faster than Sb by several orders of magnitude. This strongly suggests that the two self-atom species diffuse independently on their own sublattices. Experimental results lead us to conclude that Ga and Sb diffusio...

  11. Ga and Pt NMR study of UPtGa sub 5 and UNiGa sub 5

    CERN Document Server

    Kato, H; Tokunaga, Y; Tokiwa, Y; Ikeda, S; Onuki, Y; Kambe, S; Walstedt, R E

    2003-01-01

    Ga and Pt NMR measurements have been carried out for two isomorphs compounds, UPtGa sub 5 and UNiGa sub 5 , which exhibit different magnetic structures below T sub N. Knight shift K measurements in the paramagnetic region are reported here. The transferred hyperfine coupling constants at Ga and Pt sites are determined. The temperature independent part K sub 0 of K, which probes the conduction electron polarization at the ligand site, has been successfully evaluated. A nearly identical conduction electron structure in the paramagnetic region is suggested for these two compounds. The origin of the different magnetic structures is discussed.

  12. Hybrid Wavelength Routed and Optical Packet Switched Ring Networks for the Metropolitan Area Network

    DEFF Research Database (Denmark)

    Nord, Martin

    2005-01-01

    Increased data traffic in the metropolitan area network calls for new network architectures. This paper evaluates optical ring architectures based on optical packet switching, wavelength routing, and hybrid combinations of the two concepts. The evaluation includes overall throughput and fairness...... attractive when traffic is unbalanced....

  13. Evaluation of the external costs of energy production in the Helsinki metropolitan area

    International Nuclear Information System (INIS)

    Otterstroem, T.

    1995-01-01

    The aim of the research is to evaluate the external costs of energy production at Helsinki metropolitan area (Helsinki, Espoo, Vantaa). The previously developed valorization method for effects on population centres is adjusted. All the main health, material and environmental effects will be taken into account in the research. The effects of emissions of the energy production of the Helsinki metropolitan area on concentrations of the impurities in the air and through them on human and environment will be evaluated. The estimates will be based on the relativistic fuels consumption and the emission data of Helsinki metropolitan area. Life-cycle reasoning will be applied so that the emissions of the main components of the fuels used in the metropolitan area will be included in the estimation. The cost-effectiveness of the investments will be estimated by comparing the environmental investments of energy boards with the external costs. The methods of this work can be applied to estimation of the profitability of energy production plants from the point of view of national economy also elsewhere in the country

  14. CHANGES IN BACTERIAL COMPOSITION OF BIOFILM IN A METROPOLITAN DRINKING WATER DISTRIBUTION SYSTEM

    Science.gov (United States)

    This study examined the development of bacterial biofilms within a metropolitan distribution system. The distribution system is fed with different source water (i.e., groundwater, GW and surface water, SW) and undergoes different treatment processes in separate facilities. The b...

  15. Spirometry and impulse oscillometry (IOS) for detection of respiratory abnormalities in metropolitan firefighters.

    NARCIS (Netherlands)

    Schermer, T.R.J.; Malbon, W.; Newbury, W.; Holton, C.; Smith, M.; Morgan, M.; Crockett, A.

    2010-01-01

    BACKGROUND AND OBJECTIVE: As firefighters are at increased risk of adverse health effects, periodic examination of their respiratory health is important. The objective of this study was to establish whether the use of impulse oscillometry (IOS) reveals respiratory abnormalities in metropolitan

  16. 78 FR 40146 - Patient Safety Organizations: Voluntary Relinquishment From Northern Metropolitan Patient Safety...

    Science.gov (United States)

    2013-07-03

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Agency for Healthcare Research and Quality Patient Safety Organizations: Voluntary Relinquishment From Northern Metropolitan Patient Safety Institute AGENCY: Agency for Healthcare Research and Quality (AHRQ), HHS. ACTION: Notice of Delisting. SUMMARY: The Patient Safety and...

  17. The Metropolitan Studies Institute at USC Upstate: Translational Research that Drives Community Decision-Making

    Science.gov (United States)

    Brady, Kathleen

    2012-01-01

    The Metropolitan Studies Institute (MSI) at the University of South Carolina Upstate (USC Upstate) demonstrates a robust and unique record of community impact through community indicators research and other translational research. The MSI's work drives programmatic priorities and funding decisions, generates revenue, and increases the community's…

  18. A REGIONAL APPROACH TO THE METROPOLITAN ECONOMIC GROWTH: EVIDENCE FROM THE EUROPEAN UNION

    Directory of Open Access Journals (Sweden)

    Florin Teodor Boldeanu

    2016-09-01

    Full Text Available The main goal of this study is to contribute to metropolitan economic growth literature by carrying out an analysis for 271 areas located in the EU between 2000 and 2013. For this objective the study uses several panel data estimation techniques, namely the GMM, System GMM and the QML estimation. To check the robustness of the results, the time period is divided in two (post and ante economic crisis and by splitting the sample of metropolitan regions in two components, the Western more developed regions and the Central and South-Eastern (the formal communist states, except for Cyprus areas. The results indicate that the industrial, construction and wholesale and retail trade sectors are positively linked with metropolitan growth. The agricultural, fishery and forestry sector is negatively influencing growth. The manufacturing and ITC sectors and migration are not statistically significant. Furthermore population density and size is more important than population growth and European enlargement did not have a substantial positive impact on metropolitan growth for the Central and South-Eastern regions.

  19. A Comprehensive Survey on Student Perceptions of Cyberbullying at a Major Metropolitan University

    Science.gov (United States)

    Lawler, James P.; Molluzzo, John C.

    2015-01-01

    Cyberbullying is a concern for any college or university. Digital harassment incidents are featured daily in the news. The authors of this study examine the perceptions of students on cyberbullying at a major metropolitan university. From the findings of a student survey, the authors learn of high levels of perceptions on incidents as an issue but…

  20. The Spatial Changes of Land Use in the Bucharest Metropolitan Area 1970s – 2000s

    Directory of Open Access Journals (Sweden)

    Gabriel Simion

    2010-11-01

    Full Text Available The article explore the dimension of spatial changes of land use in the Bucharest Metropolitan Area (BMA over the past forty years. Using GIS-based land use data sets of the years 1970, 1990 and 2000, combining with statistical data, we attempted to quantify the spatial pattern of land use changes in the BMA. Our findings indicate that most significantly changes occurred with arable lands that have been reduced from 77% of total metropolitan area in 1970 to 71.3% in 2000 and in same time the built up area increase from 6.2% in 1970 to 10.4% in 2000. Vineyards and orchards suffered a reduced of their spread. In the case of vineyards the percentage of total area decrease from 2.7% in 1970 to 0.8% and regarding orchards from 1.1% in 1970 to 0.6% in 2000. The growth of built up indicate the urban influence of Bucharest city on it the large metropolitan area. The decrease of vineyards and orchards can be correlated with agrarian reform passed after the fall of socialist economic system that generated many problems for the farmers that cannot continue to cultivate the land with these kinds of cultures. These findings have implication with the futures strategies on urban and metropolitan planning in this area.

  1. A computerized model for integrating the physical environmental factors into metropolitan landscape planning

    Science.gov (United States)

    Julius Gy Fabos; Kimball H. Ferris

    1977-01-01

    This paper justifies and illustrates (in simplified form) a landscape planning approach to the environmental management of the metropolitan landscape. The model utilizes a computerized assessment and mapping system, which exhibits a recent advancement in computer technology that allows for greater accuracy and the weighting of different values when mapping at the...

  2. Analysis of Acculturative Stress and Sociocultural Adaptation among International Students at a Non-Metropolitan University

    Science.gov (United States)

    Mahmood, Hajara; Burke, Monica Galloway

    2018-01-01

    This quantitative descriptive study analyzed levels of acculturative stress and sociocultural adaptation among international students at a non-metropolitan university in the United States related to certain demographic characteristics. Surveys were used to measure international students' levels of acculturative stress and sociocultural adaptation,…

  3. The Evolution of a Multi-Instructional Teaching Center (MITC) in a Metropolitan University System.

    Science.gov (United States)

    Bell, David P.; Hayes, Edward J.; Hugetz, Edward T.; Ivancevich, John M.; Smith, Don N.; Woods, Molly R.

    1998-01-01

    The University of Houston (Texas) and its four campuses have adopted a "co-opetition" approach to create a multi-instructional teaching center to deliver educational programs and courses in the Houston metropolitan area. It has been found that citizens, legislators, administrators, faculty, and students all benefit, without sacrificing…

  4. Regeneration as an approach for the development of informal settlements in Cairo metropolitan

    Directory of Open Access Journals (Sweden)

    Ghada Farouk Hassan

    2012-09-01

    Finally the paper ends by discussing the capability of the application of this approach in dealing with the informal settlements in Cairo metropolitan as proper approach to cope with the need of dealing effectively with those shadows in the urban context.

  5. Teaching Language Minority Students in Los Angeles and Oslo--A Metropolitan Perspective nr 1

    Science.gov (United States)

    Kerchner, Charles Taylor; Özerk, Kamil

    2014-01-01

    Receiving, accommodation and education of children with immigrant background is one of the challenging issues in almost all the metropolitan areas in many countries. In our study we are exploring the impact of demographic changes on political agendas, legal frames, educational approaches, research findings and student achievement in the field of…

  6. Diversity and Educational Challenges in Oslo and Los Angeles--A Metropolitan Perspective nr 2

    Science.gov (United States)

    Özerk, Kamil; Kerchner, Charles Taylor

    2014-01-01

    Receiving, accommodation and education of children with immigrant background is one of the challenging issues in almost all the metropolitan areas in many countries. In our study we are exploring the impact of demographic changes on political agendas, legal frames, educational approaches, research findings and student achievement in the field of…

  7. Recognition of management structure and spatial planning in Tehran metropolitan area

    Directory of Open Access Journals (Sweden)

    Manijeh Lalehpour

    2016-06-01

    Full Text Available Metropolitan areas are concentrated and dense areas filled settlements and include a central urban region with its surrounding residences. Severity and complexity of issues in metropolitan areas along with intricacy and quantity of influential factors in these areas necessitate novel approaches and innovative solutions for comprehensive strategies and management coordination of land use in these regions. The present study has taken this approach to investigate management structure and spatial planning in Tehran metropolitan area. The study takes parameters like political and management decentralization, elements affecting urban management based on the sources of power and province and finally spatial domain of urban management into account. Findings revealed that decentralization in national management and political structure has limited tasks and authority of urban management. In this regard, a closer look at management structure and spatial planning of Tehran metropolitan are demonstrates that the government and its element dominate policy making, planning and spatial management of the city and inherent position of municipality and city council suffer weaknesses in their role as urban management. Results from investigating official tasks in urban management elements and their spatial domain reveals lack of coordination and Fragmentation in management structure and spatial planning in the region. The paper attempts to discuss these Fragmentation in the fields of management, function, politics and domains.

  8. Metropolitan Foodsheds as Spatial References for a Landscape-Based Assessment of Regional Food Supply

    NARCIS (Netherlands)

    Wascher, D.M.; Eupen, van M.; Corsi, S.; Sali, G.; Zasada, I.

    2016-01-01

    The Food Planning and Innovation for Sustainable Metropolitan Regions (FOODMETRES) project strives to assess the environmental and socioeconomic impacts of food chains, with regard to the spatial, logistical, and resource dimensions of growing food as well as the questions of food safety and quality

  9. The Changing Influence of Educational Policy and Race on Metropolitan Inequality, 1970-2010

    Science.gov (United States)

    Johnson, Odis, Jr.

    2017-01-01

    Schools do not receive much recognition within urban sociological research for the role they perform in shaping the demographic, structural, and social features of neighborhoods, cities, and metropolitan areas. In contrast, this article links schools, and the racial avoidance that operates through educational policy, to the extreme economic…

  10. Daily Mobility and Residential Migrations in the Montréal Metropolitan Region

    Directory of Open Access Journals (Sweden)

    Gilles Sénécal

    2013-06-01

    Full Text Available The purpose of this article is to simultaneously examine two types of mobility by developing a model of metropolitan organization that emphasizes the axis structure of mobility. The model is based on the realities of daily mobility and long-term residential mobility. Origin−Destination study results validated the axis representation of the metropolitan structure. Furthermore, building on data from a telephone survey, we considered the interactions between the two types of mobility along the Center-North axis of Montréal’s Census Metropolitan Area (CMA. The ensuing discussion on various models of metropolitan structure and their relevance today is framed in terms of the axes of mobility defined as territorial practices that are established within the patterns of daily life and are a significant factor in residential location decisions. The study raises broader issues concerning the relevance of drawing on standard models such as Burgess’s concentric zone model, Hoyt’s sector theory, Adam’s directional bias, or recent findings from the literature to understand urban form dynamics in the CMA.

  11. The metropolitan park: searching for a new typology for intermediate green areas in urban fields

    NARCIS (Netherlands)

    Brinkhuijsen, M.; Velde, van der R.; Graaf, de E.; Kruit, E.; Lodder, A.

    2011-01-01

    Ongoing urbanization in metropolitan regions creates a wish for large green areas in the urban peripheries for recreational purposes. Agricultural landscapes are being replaced with woods, nature and water to provide citizens with space for outdoor recreation and other activities. Park-like settings

  12. Do Metropolitan and Nonmetropolitan Chicano Youth Differ: A Study of South Texas Teen-Agers - 1973.

    Science.gov (United States)

    Venegas, Moises; Kuvlesky, William

    Based on comparative data from two 1973 studies, this study examined whether or not the occupational and educational status projections and language usage patterns of Mexican American teenagers living in a large metropolitan area differed from those of teenagers living in isolated, relatively small nonmetropolitan places. The two separate, but…

  13. On scaling of scientific knowledge production in U.S. metropolitan areas

    NARCIS (Netherlands)

    Nomaler, Önder; Frenken, Koen; Heimeriks, Gaston

    2014-01-01

    Using data on all scientific publications from the Scopus database, we find a superlinear scaling effect for U.S. metropolitan areas as indicated by the increase of per capita publication output with city size. We also find that the variance of residuals is much higher for mid-sized cities (100,000

  14. Metropolitan natural area protection to maximize public access and species representation

    Science.gov (United States)

    Jane A. Ruliffson; Robert G. Haight; Paul H. Gobster; Frances R. Homans

    2003-01-01

    In response to widespread urban development, local governments in metropolitan areas in the United States acquire and protect privately-owned open space. We addressed the planner's problem of allocating a fixed budget for open space protection among eligible natural areas with the twin objectives of maximizing public access and species representation. Both...

  15. A metropolitan optical network with support for multicasting in the optical domain

    NARCIS (Netherlands)

    Dey, D.; Koonen, A.M.J.; Bochove, van A.C.; Geuzebroek, D.; Salvador, M.R.; Berghmans, F.; Thienpont, H.; Danckaert, J.; Desmet, L.

    2001-01-01

    We present the FLAMINGO1 network architecture, an all-optical wavelength-and-timeslotted Metropolitan Optical Network based on a multiple-ring topology. A couple of important aspects of this architecture include all-optical packet switching at intermediate nodes on a ring and the ability to put IP

  16. A Metropolitan Optical Network with support for multicasting in the optical domain

    NARCIS (Netherlands)

    Dey, D.; Koonen, A.M.J.; van Bochove, A.C.; Geuzebroek, D.H.; Salvador, M.R.; Thienpont, H.; Berghmans, F.; Danckaert, J.; Desmet, L.

    2001-01-01

    We present the FLAMINGO1 network architecture, an all-optical wavelength-and-timeslotted Metropolitan Optical Network based on a multiple-ring topology. A couple of important aspects of this architecture include all-optical packet switching at intermediate nodes on a ring and the ability to put IP

  17. The Neighborhood Unit: Schools, Segregation, and the Shaping of the Modern Metropolitan Landscape

    Science.gov (United States)

    Erickson, Ansley T.; Highsmith, Andrew R.

    2018-01-01

    Background/Context: In the first half of the 20th century, American policy makers at all levels of government, alongside housing and real estate industry figures, crafted mechanisms of racial exclusion that helped to segregate metropolitan residential landscapes. Although educators and historians have recognized the long-term consequences of these…

  18. Climate change impacts on extreme temperature mortality in select metropolitan areas of the United States

    Science.gov (United States)

    Projected mortality from climate change-driven impacts on extremely hot and cold days increases significantly over the 21st century in a large group of United States Metropolitan Statistical Areas. Increases in projected mortality from more hot days are greater than decreases in ...

  19. Regional Disparities and Social Cohesion Policies. The Case of the Metropolitan Area of Bari (Italy

    Directory of Open Access Journals (Sweden)

    ROSALINA GRUMO

    2015-06-01

    Full Text Available The role of Regions appears reconfigured by the "reshaping" of national States. Besides, under a sub-regional scale, forms of governance have been launched, redefining a new territoriality. In Italy, the role of the Regions and Cities is more and more important in the decision-making processes of the territories and it is also characterized by the recent establishment of the metropolitan cities, but still not geo-politically defined. There is, in fact, a constitutional reform process through the region's reorganization legislative autonomy and strengthening of local governments. In this context, some areas are characterized by social unrest that includes new forms of poverty, urban malaise and marginalization, due also to the financial and economic crisis whose signs of recovery are still very weak. In the European Union, the programming decisions considered the policy of development and cohesion also at the local scale. The 2014-2020 EU programming cycle, in fact, has defined the main role of metropolitan cities, but also of cities and internal areas. The contribution will analyze Puglia, region of southern Italy, and the metropolitan area of Bari, the regional capital, in order to verify policies concerning the social field, both through "strategic planning" and launching the so-called "smart city" experience. In the metropolitan city, indeed, there is already an orientation towards the "social innovation" to address the issues of social cohesion and inclusion, consistent to sustainable development.

  20. A Political-Ecological Analysis of Income Inequality in the Metropolitan Area.

    Science.gov (United States)

    Bollens, Scott A.

    1986-01-01

    Metropolitan development is not simply a result of ecological factors. Governmental organization affects the incentives of localities and helps determine patterns of growth. This study updates previous studies on factors influencing residential area income inequality. Modification of the variables in the ecological explanation will increase…

  1. Bacterial Composition of Biofilms Collected From Two Service Areas in a Metropolitan Drinking Water Distribution System

    Science.gov (United States)

    The development and succession of bacteria were examined by 16S rRNA gene clone libraries generated from various biofilms within a metropolitan water distribution system. Biofilms were obtained from off-line devices using polycarbonate coupons from annular reactors incubated for ...

  2. There Are No Subways in Lickingville: Metropolitan Models Don't Work for Rural People.

    Science.gov (United States)

    Hillman, Arnold

    This book presents an overview of the problems facing rural America and offers solutions at the national, state, and local levels. The combination of public lack of awareness and metropolitan-centered authority has created a view of rural America and its people that is contrary to both the data and actual living conditions. Rural education has…

  3. Peer Mentoring Experiences of Psychology Students at the London Metropolitan University Writing Centre

    Science.gov (United States)

    Bakhshi, Savita; Harrington, Kathy; O'Neill, Peter

    2008-01-01

    "It really helps knowing that you are going to have someone around to help you..." This short article reports on research taking place into peer writing tutorials at London Metropolitan University and examines in particular, the experiences of psychology students who have taken part in the scheme. Some of the implications of this…

  4. MeTriS : Metropolitan Transportation Information System : applying space based technologies for freight congestion mitigation.

    Science.gov (United States)

    2010-06-01

    Port operations are at the heart of some of the most dynamic metropolitan centers in the : world: London, New York, Los Angeles, Singapore and Hong Kong, to name a few. Ports are : critical cogs in national and local economies, but their operations a...

  5. Geographically varying associations between personality and life satisfaction in the London metropolitan area

    NARCIS (Netherlands)

    Jokela, M.; Bleidorn, W.; Lamb, M.E.; Gosling, S.D.; Rentfrow, P.J.

    2015-01-01

    Residential location is thought to influence people’s well-being, but different individuals may value residential areas differently. We examined how life satisfaction and personality traits are geographically distributed within the UK London metropolitan area, and how the strength of associations

  6. Polycentric Metropolitan Form: Application of a ‘Northern’ Concept in Latin America

    Directory of Open Access Journals (Sweden)

    Arie Romein

    2014-07-01

    Full Text Available Since the mid 20th century, large urban areas in advanced economies have experienced a fundamental transformation from relatively compact monocentric cities towards more extended polycentric metropolitan areas. By now, it is being commented repeatedly, but not investigated systematically that the concept of polycentricity is also adequate to characterise recent metropolitan dynamics in Latin-America.This paper aims to present a few key-issues for a future research agenda into polycentricity in Latin-American metropolitan areas. These elements are identified from a review of existing literature. Since no clear-cut definition and operationalisation of polycentricity exist yet, we distinguish some key-elements of this phenomenon in North America as a frame of reference for this review. It reveals that ‘polycentricity U.S. style’ is at best dawning in Latin-America. In order to achieve a more appropriate picture of polycentricity of Latin American metropolitan areas, our ideas for a research agenda take into account these areas typical economic, social and spatial conditions.

  7. Photoluminescence characterization of GaAs/GaAs0.64P0.19Sb0.17/GaAs heterostructure

    International Nuclear Information System (INIS)

    Chen, J.Y.; Chen, B.H.; Huang, Y.S.; Chin, Y.C.; Tsai, H.S.; Lin, H.H.; Tiong, K.K.

    2013-01-01

    Interfacial characteristics of GaAs/GaAs 0.64 P 0.19 Sb 0.17 GaAs heterostructures and emission properties of a quaternary GaAs 0.64 P 0.19 Sb 0.17 layer were studied by excitation-power- and temperature-dependent photoluminescence (PL) measurements. The GaAs-to-GaAsPSb upper interface related emission feature and signals from GaAsPSb and GaAs were observed and characterized. The upper interface related emission peak was attributed to the radiative recombination of spatially separated electron–hole pairs and suggesting the type-II alignment at the GaAs/GaAsPSb interface. The localized excitonic emission feature of GaAsPSb revealed a blueshift due to the saturation effect of localized states and showed a fast thermal-quench with the increase of temperature. The temperature variation of the band edge emission signal of GaAsPSb was found to follow that of GaAs closely. -- Highlights: ► PL characterization of GaAs/GaAsPSb/GaAs heterostructure. ► Type-II alignment at the GaAs/GaAsPSb interface. ► Near-band-edge emission lines of GaAsPSb

  8. [Urban and population development of the city of Puebla and its metropolitan area].

    Science.gov (United States)

    Barbosa Prieto, A

    1991-12-01

    Metropolitanization has been considered an important problem of regional development in developing countries. Attitudes toward the metropolis have been ambivalent in Latin America. On the 1 hand the metropolis is viewed as an obstacle to development that absorbs resources from the zone of influence and incurs high social costs of urbanization, but on the hand it is also viewed as a form of achieving levels of economic efficiency comparable to those of developed countries. Metropolitan areas should not be viewed as isolated, but rather as important points of demographic and manpower attraction, poles of economic growth and technological and cultural innovation. "Urban areas" and "metropolitan zones" are distinct ways of defining and delimiting urban phenomena. Although there is no consensus as to the exact definitions of these 2 urban units, it is generally accepted that the urban area is the city itself as well as the contiguous built up area reaching in all directions to the onset of nonurban land uses such as forests territorial extension that includes the politico-administrative units with urban characteristics such as work places and residences for nonagricultural workers, and that maintain constant and intense socioeconomic interrelations with the central city. The process of urban planning in the metropolitan zone of Puebla, Mexico, began in institutional form in 1980 with master plans for the population centers of Puebla, Amozoc, San Andres and San Pedro Cholula, and Zacatelco in the state of Tlaxcala. In 1987., an attempt was made by the governments of the states of Puebla and Tlaxcala to develop a plan for the metropolitan zone as a single unit. Population growth was greater within the city of Puebla than in the metropolitan zone from 1960-80, but after 1980 growth in the outlying areas exceeded that in the center city. The population density of the city of Puebla declined from 160/hectare in 1950 to 76/hectare in 1990, the result of progressive dispersion

  9. AlGaN nanocolumns and AlGaN/GaN/AlGaN nanostructures grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Ristic, J.; Sanchez-Garcia, M.A.; Ulloa, J.M.; Calleja, E. [Departamento de Ingenieria Electronica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Sanchez-Paramo, J.; Calleja, J.M. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Jahn, U.; Trampert, A.; Ploog, K.H. [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2002-12-01

    This work reports on the characterization of hexagonal, single crystal AlGaN nanocolumns with diameters in the range of 30 to 100 nm grown by molecular beam epitaxy on Si(111) substrates. The change of the flux ratio between the Al and the total III-element controls the alloy composition. The Al composition trend versus the Al flux is consistent both with the E{sub 2} phonon energy values measured by inelastic light scattering and the luminescence emission peaks position. High quality low dimensional AlGaN/GaN/AlGaN heterostructures with five GaN quantum discs, 2 and 4 nm thick, embedded into the AlGaN columns, were designed in order to study the quantum confinement effects. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  10. Characteristics study of 2DEG transport properties of AlGaN/GaN and AlGaAs/GaAs-based HEMT

    International Nuclear Information System (INIS)

    Lenka, T. R.; Panda, A. K.

    2011-01-01

    Growth of wide bandgap material over narrow bandgap material, results into a two dimensional electron gas (2DEG) at the heterointerface due to the conduction band discontinuity. In this paper the 2DEG transport properties of AlGaN/GaN-based high electron mobility transistor (HEMT) is discussed and its effect on various characteristics such as 2DEG density, C-V characteristics and Sheet resistances for different mole fractions are presented. The obtained results are also compared with AlGaAs/GaAs-based HEMT for the same structural parameter as like AlGaN/GaN-based HEMT. The calculated results of electron sheet concentration as a function of the Al mole fraction are in excellent agreement with some experimental data available in the literature.

  11. Role of AlGaN/GaN interface traps on negative threshold voltage shift in AlGaN/GaN HEMT

    Science.gov (United States)

    Malik, Amit; Sharma, Chandan; Laishram, Robert; Bag, Rajesh Kumar; Rawal, Dipendra Singh; Vinayak, Seema; Sharma, Rajesh Kumar

    2018-04-01

    This article reports negative shift in the threshold-voltage in AlGaN/GaN high electron mobility transistor (HEMT) with application of reverse gate bias stress. The device is biased in strong pinch-off and low drain to source voltage condition for a fixed time duration (reverse gate bias stress), followed by measurement of transfer characteristics. Negative threshold voltage shift after application of reverse gate bias stress indicates the presence of more carriers in channel as compared to the unstressed condition. We propose the presence of AlGaN/GaN interface states to be the reason of negative threshold voltage shift, and developed a process to electrically characterize AlGaN/GaN interface states. We verified the results with Technology Computer Aided Design (TCAD) ATLAS simulation and got a good match with experimental measurements.

  12. Comparison of MOVPE grown GaAs, InGaAs and GaAsSb covering layers for different InAs/GaAs quantum dot applications

    Czech Academy of Sciences Publication Activity Database

    Zíková, Markéta; Hospodková, Alice; Pangrác, Jiří; Oswald, Jiří; Hulicius, Eduard

    2017-01-01

    Roč. 464, Apr (2017), s. 59-63 ISSN 0022-0248 R&D Projects: GA MŠk LO1603 Institutional support: RVO:68378271 Keywords : MOVPE * quantum dot * strain reducing layer * InAs * GaAsSb * InGaAs Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.751, year: 2016

  13. Lithium compensation of GaAs

    International Nuclear Information System (INIS)

    Alexiev, D.; Tavendale, A.J.

    1988-08-01

    Defects generated following Li diffusion into GaAs were studied by optical deep level transient spectroscopy (ODLTS) and deep level transient spectroscopy (DLTS). In an exploratory series of experiments, the effect of Li diffusion on existing trap spectra, defect generation and as a means for the compensation of GaAs was studied. The variables included diffusion temperature, initial trap spectra of GaAs and annealing periods. Detailed measurements of trap energies were made

  14. Characterizing Spatial and Temporal Patterns of Thermal Environment and Air Quality in Taipei Metropolitan Area

    Science.gov (United States)

    Juang, J. Y.; Sun, C. H.; Jiang, J. A.; Wen, T. H.

    2017-12-01

    The urban heat island effect (UHI) caused by the regional-to-global environmental changes, dramatic urbanization, and shifting in land-use compositions has becoming an important environmental issue in recent years. In the past century, the coverage of urban area in Taipei Basin has dramatically increasing by ten folds. The strengthen of UHI effect significantly enhances the frequency of warm-night effect, and strongly influences the thermal environment of the residents in the Greater Taipei Metropolitan. In addition, the urban expansions due to dramatic increasing in urban populations and traffic loading significantly impacts the air quality and causes health issue in Taipei. In this study, the main objective is to quantify and characterize the temporal and spatial distributions of thermal environmental and air quality in the Greater Taipei Metropolitan Area by using monitoring data from Central Weather Bureau, Environmental Protection Administration. In addition, in this study, we conduct the analysis on the distribution of physiological equivalent temperature in the micro scale in the metropolitan area by using the observation data and quantitative simulation to investigate how the thermal environment is influenced under different conditions. Furthermore, we establish a real-time mobile monitoring system by using wireless sensor network to investigate the correlation between the thermal environment, air quality and other environmental factors, and propose to develop the early warning system for heat stress and air quality in the metropolitan area. The results from this study can be integrated into the management and planning system, and provide sufficient and important background information for the development of smart city in the metropolitan area in the future.

  15. Cation disorder in Ga1212.

    Science.gov (United States)

    Greenwood, K B; Ko, D; Vander Griend, D A; Sarjeant, G M; Milgram, J W; Garrity, E S; DeLoach, D I; Poeppelmeier, K R; Salvador, P A; Mason, T O

    2000-07-24

    Substitution of calcium for strontium in LnSr2-xCaxCu2GaO7 (Ln = La, Pr, Nd, Gd, Ho, Er, Tm, and Yb) materials at ambient pressure and 975 degrees C results in complete substitution of calcium for strontium in the lanthanum and praseodymium systems and partial substitution in the other lanthanide systems. The calcium saturation level depends on the size of the Ln cation, and in all cases, a decrease in the lattice parameters with calcium concentration was observed until a common, lower bound, average A-cation size is reached. Site occupancies from X-ray and neutron diffraction experiments for LnSr2-xCaxCu2GaO7 (x = 0 and x = 2) confirm that the A-cations distribute between the two blocking-layer sites and the active-layer site based on size. A quantitative link between cation distribution and relative site-specific cation enthalpy for calcium, strontium, and lanthanum within the gallate structure is derived. The cation distribution in other similar materials can potentially be modeled.

  16. GaN Bulk Growth and Epitaxy from Ca-Ga-N Solutions, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR proposal addresses the liquid phase epitaxy (LPE) of gallium nitride (GaN) films using nitrogen-enriched metal solutions. Growth of GaN from solutions...

  17. Tunable High efficiency Resonant Tunneling GaN/AlGaN MQW UV Detectors

    National Research Council Canada - National Science Library

    Wang, W. B; Zhang, S. K; Alfano, R. R

    2005-01-01

    ...)-based UV photodetectors. During the grant period, more than twenty six GaN/AlGaN MQW phoptodetectors with different types of device structures and control samples have been fabricated and investigated to achieve the proposed...

  18. InGaN nanoinclusions in an AlGaN matrix

    International Nuclear Information System (INIS)

    Sizov, V. S.; Tsatsul'nikov, A. F.; Lundin, V. V.

    2008-01-01

    GaN-based structures with InGaN quantum dots in the active region emitting in the near-ultraviolet region are studied. In this study, two types of structures, namely, with InGaN quantum dots in a GaN or AlGaN matrix, are compared. Photoluminescence spectra are obtained for both types of structures in a temperature range of 80-300 K and at various pumping densities, and electroluminescence spectra are obtained for light-emitting (LED) structures with various types of active region. It is shown that the structures with quantum dots in the AlGaN matrix are more stable thermally due to the larger localization energy compared with quantum dots in the GaN matrix. Due to this, the LED structures with quantum dots in an AlGaN matrix are more effective.

  19. Development of Passivation Technology for Improved GaN/AlGaN HEMT Performance and Reliability

    National Research Council Canada - National Science Library

    Abernathy, C. R; Hunter-Edwards, Angela

    2005-01-01

    .... As part of the recipe development we have studied fundamental characteristics of the native oxides on GaN and AlGaN surfaces using XPS and compared the results to oxides generated by exposure to UV...

  20. Nanomaterial disordering in AlGaN/GaN UV LED structures

    International Nuclear Information System (INIS)

    Shabunina, E I; Levinshtein, M E; Kulagina, M M; Petrov, V N; Ratnikov, V V; Smirnova, I N; Troshkov, S I; Shmidt, N M; Kurin, S Yu; Makarov, Yu N; Chernyakov, A E; Usikov, A S; Helava, H

    2015-01-01

    Multifractal analysis was applied to characterize quantitatively nanostructural disordering in HVPE-grown AlGaN/GaN UV LED structures. A higher level of leakage currents shunting the active region of LEDs by an extended defect system is correlated with higher values of multifractal parameters (MFs). As a result, the concentration of injected carriers participating in radiative recombination in the active region is reduced. MFs and the conductivity of quasi-ohmic shunts localized in an extended defect system are higher in AlGaN/GaN structures than in InGaN/GaN structures. It is one of the reasons behind the low external quantum efficiency of AlGaN/GaN UV LEDs. (paper)

  1. Reducing Threshold of Multi Quantum Wells InGaN Laser Diode by Using InGaN/GaN Waveguide

    Science.gov (United States)

    Abdullah, Rafid A.; Ibrahim, Kamarulazizi

    2010-07-01

    ISE TCAD (Integrated System Engineering Technology Computer Aided Design) software simulation program has been utilized to help study the effect of using InGaN/GaN as a waveguide instead of conventional GaN waveguide for multi quantum wells violet InGaN laser diode (LD). Simulation results indicate that the threshold of the LD has been reduced by using InGaN/GaN waveguide where InGaN/GaN waveguide increases the optical confinement factor which leads to increase the confinement carriers at the active region of the LD.

  2. Self-consistent simulation of carrier confinement characteristics in (AlyGa1−yN/AlN)SLs/GaN/(InxGa1−xN/GaN)MQW/GaN heterostructures

    International Nuclear Information System (INIS)

    Ding Jieqin; Wang Xiaoliang; Xiao Hongling; Wang Cuimei; Yin Haibo; Chen Hong; Feng Chun; Jiang Lijuan

    2012-01-01

    Highlights: ► We present calculations of carrier confinement characteristics. ► An optimization of In x Ga 1−x N/GaN multiquantum-well (MQW) was made. ► 2DEG sheet carrier density in designed heterostructure is greatly increased. ► Interface roughness and alloy disorder scattering reduced. ► Carrier mobility will be improved in designed heterostructure. - Abstract: We present calculations of carrier confinement characteristics in (Al y Ga 1−y N/AlN)SLs/GaN/(In x Ga 1−x N/GaN)MQW/GaN heterojunction structure in the presence of spontaneous and piezoelectrically induced polarization effects. The calculations were made using a self-consistent solution of the Schrödinger, Poisson, potential and charge balance equations. An optimization of In x Ga 1−x N/GaN multiquantum-well (MQW) was made firstly including thickness of GaN channel, InGaN, and indium composition of In x Ga 1−x N in order to increase carrier density and mobility, and the influence of pairs of AlGaN/AlN superlattices (SLs) and InGaN/GaN MQWs on structure was discussed. Theoretical calculations clearly indicate that the two-dimensional electron gas (2DEG) sheet carrier density in designed heterostructure is greatly increased due to the enhancing of carrier confinement compared to those in conventional AlGaN/GaN one at the similar Al composition. Furthermore, the calculated carrier distribution shows that carrier mobility will be improved by reducing interface roughness and alloy disorder scattering in designed heterostructure.

  3. Strain-balanced InGaN/GaN multiple quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Van Den Broeck, D. M.; Hosalli, A. M.; Bedair, S. M. [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Bharrat, D.; El-Masry, N. A. [Department of Material Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-07-21

    InGaN/GaN multiple quantum well (MQW) structures suffer from a high amount of compressive strain in the InGaN wells and the accompanied piezoelectric field resulting in both a blue shift in emission and a reduction of emission intensity. We report the growth of In{sub x}Ga{sub 1−x}N/GaN “strain-balanced” multiple quantum wells (SBMQWs) grown on thick In{sub y}Ga{sub 1−y}N templates for x > y by metal organic chemical vapor deposition. SBMQWs consist of alternating layers of In{sub x}Ga{sub 1−x}N wells and GaN barriers under compressive and tensile stress, respectively, which have been lattice matched to a thick In{sub y}Ga{sub 1−y}N template. Growth of the In{sub y}Ga{sub 1−y}N template is also detailed in order to achieve thick, relaxed In{sub y}Ga{sub 1−y}N grown on GaN without the presence of V-grooves. When compared to conventional In{sub x}Ga{sub 1−x}N/GaN MQWs grown on GaN, the SBMQW structures exhibit longer wavelength emission and higher emission intensity for the same InN mole fraction due to a reduction in the well strain and piezoelectric field. By matching the average lattice constant of the MQW active region to the lattice constant of the In{sub y}Ga{sub 1−y}N template, essentially an infinite number of periods can be grown using the SBMQW growth method without relaxation-related effects. SBMQWs can be utilized to achieve longer wavelength emission in light emitting diodes without the use of excess indium and can be advantageous in addressing the “green gap.”.

  4. Growth and characterization of Ga(As,N) and (In,Ga)(As,N)

    International Nuclear Information System (INIS)

    Mussler, G.

    2005-01-01

    This dissertation deals with the MBE growth and characterization of Ga(As,N) and (In,Ga)(As,N). The work commences with the optimization of the Ga(As,N) growth. Owing to a large miscibility gap of GaN in GaAs, the incorporation of nitrogen into GaAs causes a structural degradation that is dependent on the substrate temperature, the nitrogen concentration, and the quantum well thickness. Another problem related to the growth of Ga(As,N) are point defects that have a detrimental influence on optical properties. A thermal treatment of Ga(As,N) reduces the concentration of these point defects. This leads to a substantial improvement of optical properties. We will show that nitrogen split interstitials that incorporate into gallium and arsenic vacancies may be attributed to these point defects. A thermal treatment of Ga(As,N) at high temperatures, on the contrary, results in a creation of extended defects which are detrimental to optical properties. We show that the temperature of the thermal treatment that yields the highest photoluminescence intensity is nitrogen concentration-dependent. The growth of (In,Ga)(As,N) is similar with respect to Ga(As,N). Again, one has to face a high miscibility gap of (In,Ga)N in (In,Ga)As that results in a structural degradation. A thermal treatment of (In,Ga)(As,N) is also beneficial for improving optical properties. We show that a thermal treatment of (In,Ga)As results in an indium diffusion that is suppressed by the incorporation of nitrogen. The characterization of (In,Ga)(As,N) edge emitting lasers shows emission at wavelengths up to 1366 nm. With higher nitrogen concentrations, there is a strong increase of the threshold current density and a decrease of the output power

  5. Fabrication of InGaN/GaN nanopillar light-emitting diode arrays

    DEFF Research Database (Denmark)

    Ou, Yiyu; Fadil, Ahmed; Ou, Haiyan

    Nanopillar InGaN/GaN green light-emitting diode arrays were fabricated by using self-assembled nanopatterning and dry etching process. Both internal and external quantum efficiency were increased due to strain relaxation and enhanced light extraction.......Nanopillar InGaN/GaN green light-emitting diode arrays were fabricated by using self-assembled nanopatterning and dry etching process. Both internal and external quantum efficiency were increased due to strain relaxation and enhanced light extraction....

  6. Resonant circular photogalvanic effect in GaN/AlGaN heterojunctions

    NARCIS (Netherlands)

    Wittmann, B.; Golub, L. E.; Danilov, S. N.; Karch, J.; Reitmaier, C.; Kvon, Z. D.; Vinh, N. Q.; van der Meer, A. F. G.; Murdin, B.; Ganichev, S. D.

    2008-01-01

    The resonant circular photogalvanic effect is observed in wurtzite (0001)-oriented GaN low-dimensional structures excited by infrared radiation. The current is induced by angular-momentum transfer of photons to the photoexcited electrons at resonant intersubband optical transitions in a GaN/AlGaN

  7. Recessed insulator and barrier AlGaN/GaN HEMT: A novel structure ...

    Indian Academy of Sciences (India)

    2017-03-08

    Mar 8, 2017 ... AlGaN/GaN high electron mobility transistor; breakdown voltage; output power density; short channel effect ... is an n-type heavily doped Al0.32Ga0.68N while the ..... [15] S E J Mahabadi, A A Orouji, P Keshavarzi and H A.

  8. Characterization of GaN/AlGaN epitaxial layers grown by ...

    Indian Academy of Sciences (India)

    GaN and AlGaN epitaxial layers are grown by a metalorganic chemical ... reported by introducing annealing of the GaN layer in nitrogen [5], Fe doping [6], .... [2] Y F Wu, S M Wood, R P Smith, S Sheppard, S T Allen, P Parikh and J Milligan,.

  9. A InGaN/GaN quantum dot green (λ=524 nm) laser

    KAUST Repository

    Zhang, Meng; Banerjee, Animesh; Lee, Chi-Sen; Hinckley, John M.; Bhattacharya, Pallab

    2011-01-01

    The characteristics of self-organized InGaN/GaN quantum dot lasers are reported. The laser heterostructures were grown on c-plane GaN substrates by plasma-assisted molecular beam epitaxy and the laser facets were formed by focused ion beam etching

  10. High resolution x-ray diffraction analyses of GaN/LiGaO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Matyi, R.J. [Department of Materials Science and Engineering University of Wisconsin, Madison, WI (United States); Doolittle, W.A.; Brown, A.S. [School of Electrical and Computer Engineering Georgia Institute of Technology, Atlanta, GA (United States)

    1999-05-21

    Lithium gallate (LiGaO{sub 2}) is gaining increasing attention as a potential substrate for the growth of the important semiconductor GaN. In order to better understand this material we have performed high-resolution double- and triple-axis x-ray diffraction analyses of both the starting LiGaO{sub 2} and GaN/LiGaO{sub 2} following epitaxial growth. A high-resolution triple-axis reciprocal space map of the substrate showed a sharp, well-defined crystal truncation rod and a symmetric streak of intensity perpendicular to q{sub 002}, suggesting high structural quality with mosaic spread. Triple-axis scans following GaN growth showed (1) the development of isotropic diffuse scatter around the LiGaO{sub 2} (002) reflection, (2) the presence of a semi-continuous intensity streak between the LiGaO{sub 2} (002) and GaN (0002) reflections, and (3) a compact pattern of diffuse scatter around the GaN (0002) reflection that becomes increasingly anisotropic as the growth temperature is increased. These results suggest that LiGaO{sub 2} permits the epitaxial growth of GaN with structural quality that may be superior to that observed when growth is performed on SiC or Al{sub 2}O{sub 3}. (author)

  11. Characterization of a Ga-assisted GaAs nanowire array solar cell on si substrate

    DEFF Research Database (Denmark)

    Boulanger, J. P.; Chia, A. C. E.; Wood, B.

    2016-01-01

    A single-junction core-shell GaAs nanowire (NW) solar cell on Si (1 1 1) substrates is presented. A Ga-assisted vapor–liquid–solid growth mechanism was used for the formation of a patterned array of radial p-i-n GaAs NWs encapsulated in AlInP passivation. Novel device fabrication utilizing facet-...

  12. Exploring the radiosynthesis and in vitro characteristics of [68 Ga]Ga-DOTA-Siglec-9.

    Science.gov (United States)

    Jensen, Svend B; Käkelä, Meeri; Jødal, Lars; Moisio, Olli; Alstrup, Aage K O; Jalkanen, Sirpa; Roivainen, Anne

    2017-07-01

    Vascular adhesion protein 1 is a leukocyte homing-associated glycoprotein, which upon inflammation rapidly translocates from intracellular sources to the endothelial cell surface. It has been discovered that the cyclic peptide residues 283-297 of sialic acid-binding IgG-like lectin 9 (Siglec-9) "CARLSLSWRGLTLCPSK" bind to vascular adhesion protein 1 and hence makes the radioactive analogues of this compound ([ 68 Ga]Ga-DOTA-Siglec-9) interesting as a noninvasive visualizing marker of inflammation. Three different approaches to the radiosynthesis of [ 68 Ga]Ga-DOTA-Siglec-9 are presented and compared with previously published methods. A simple, robust radiosynthesis of [ 68 Ga]Ga-DOTA-Siglec-9 with a yield of 62% (non decay-corrected) was identified, and it had a radiochemical purity >98% and a specific radioactivity of 35 MBq/nmol. Furthermore, the protein binding and stability of [ 68 Ga]Ga-DOTA-Siglec-9 were analyzed in vitro in mouse, rat, rabbit, pig, and human plasma and compared with in vivo pig results. The plasma in vitro protein binding of [ 68 Ga]Ga-DOTA-Siglec-9 was the lowest in the pig followed by rabbit, human, rat, and mouse. It was considerably higher in the in vivo pig experiments. The in vivo stability in pigs was lower than the in vitro stability. Despite considerable species differences, the observed characteristics of [ 68 Ga]Ga-DOTA-Siglec-9 are suitable as a positron emission tomography tracer. Copyright © 2017 John Wiley & Sons, Ltd.

  13. Silicon—a new substrate for GaN growth

    Indian Academy of Sciences (India)

    Unknown

    of GaN devices based on silicon is the thermal mismatch of GaN and Si, which generates cracks. In 1998, the .... Considerable research is being carried out on GaN HEMTs at present. ... by InGaN/GaN multiquantum well in MOVPE was first.

  14. Leaching Functions from the Outer Metropolitan Zones (Trade, Services - Increasing Peripherality of Small Towns and Rural Areas

    Directory of Open Access Journals (Sweden)

    Krystian Heffner

    2015-01-01

    Full Text Available Intensive spatial processes taking place around metropolitan areas leads to many economic, structural and social changes in their surroundings. The small towns and rural areas located in the outer zone of metropolitan areas are most affected by this functional changes. In the outer zone of a big urban canters appears a lot of new competing possibilities on the labor market and a comprehensive commercial, service and cultural offer to smaller centres. One of the most competitive advantage of the metropolitan zones becomes modern shopping centres being established in the most accessible places, providing a comprehensive shopping-services and even cultural-recreational offer.

  15. White emission from non-planar InGaN/GaN MQW LEDs grown on GaN template with truncated hexagonal pyramids.

    Science.gov (United States)

    Lee, Ming-Lun; Yeh, Yu-Hsiang; Tu, Shang-Ju; Chen, P C; Lai, Wei-Chih; Sheu, Jinn-Kong

    2015-04-06

    Non-planar InGaN/GaN multiple quantum well (MQW) structures are grown on a GaN template with truncated hexagonal pyramids (THPs) featuring c-plane and r-plane surfaces. The THP array is formed by the regrowth of the GaN layer on a selective-area Si-implanted GaN template. Transmission electron microscopy shows that the InGaN/GaN epitaxial layers regrown on the THPs exhibit different growth rates and indium compositions of the InGaN layer between the c-plane and r-plane surfaces. Consequently, InGaN/GaN MQW light-emitting diodes grown on the GaN THP array emit multiple wavelengths approaching near white light.

  16. Multicharacterization approach for studying InAl(Ga)N/Al(Ga)N/GaN heterostructures for high electron mobility transistors

    Energy Technology Data Exchange (ETDEWEB)

    Naresh-Kumar, G., E-mail: naresh.gunasekar@strath.ac.uk; Trager-Cowan, C. [Dept of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Vilalta-Clemente, A.; Morales, M.; Ruterana, P. [CIMAP UMR 6252 CNRS-ENSICAEN-CEA-UCBN 14050 Caen Cedex (France); Pandey, S.; Cavallini, A.; Cavalcoli, D. [Dipartimento di Fisica Astronomia, Università di Bologna, 40127 Bologna (Italy); Skuridina, D.; Vogt, P.; Kneissl, M. [Institute of Solid State Physics, Technical University Berlin, 10623 Berlin (Germany); Behmenburg, H.; Giesen, C.; Heuken, M. [AIXTRON SE, Kaiserstr. 98, 52134 Herzogenrath (Germany); Gamarra, P.; Di Forte-Poisson, M. A. [Thales Research and Technology, III-V Lab, 91460 Marcoussis (France); Patriarche, G. [LPN, Route de Nozay, 91460 Marcoussis (France); Vickridge, I. [Institut des NanoSciences, Université Pierre et Marie Curie, 75015 Paris (France)

    2014-12-15

    We report on our multi–pronged approach to understand the structural and electrical properties of an InAl(Ga)N(33nm barrier)/Al(Ga)N(1nm interlayer)/GaN(3μm)/ AlN(100nm)/Al{sub 2}O{sub 3} high electron mobility transistor (HEMT) heterostructure grown by metal organic vapor phase epitaxy (MOVPE). In particular we reveal and discuss the role of unintentional Ga incorporation in the barrier and also in the interlayer. The observation of unintentional Ga incorporation by using energy dispersive X–ray spectroscopy analysis in a scanning transmission electron microscope is supported with results obtained for samples with a range of AlN interlayer thicknesses grown under both the showerhead as well as the horizontal type MOVPE reactors. Poisson–Schrödinger simulations show that for high Ga incorporation in the Al(Ga)N interlayer, an additional triangular well with very small depth may be exhibited in parallel to the main 2–DEG channel. The presence of this additional channel may cause parasitic conduction and severe issues in device characteristics and processing. Producing a HEMT structure with InAlGaN as the barrier and AlGaN as the interlayer with appropriate alloy composition may be a possible route to optimization, as it might be difficult to avoid Ga incorporation while continuously depositing the layers using the MOVPE growth method. Our present work shows the necessity of a multicharacterization approach to correlate structural and electrical properties to understand device structures and their performance.

  17. Multicharacterization approach for studying InAl(GaN/Al(GaN/GaN heterostructures for high electron mobility transistors

    Directory of Open Access Journals (Sweden)

    G. Naresh-Kumar

    2014-12-01

    Full Text Available We report on our multi–pronged approach to understand the structural and electrical properties of an InAl(GaN(33nm barrier/Al(GaN(1nm interlayer/GaN(3μm/ AlN(100nm/Al2O3 high electron mobility transistor (HEMT heterostructure grown by metal organic vapor phase epitaxy (MOVPE. In particular we reveal and discuss the role of unintentional Ga incorporation in the barrier and also in the interlayer. The observation of unintentional Ga incorporation by using energy dispersive X–ray spectroscopy analysis in a scanning transmission electron microscope is supported with results obtained for samples with a range of AlN interlayer thicknesses grown under both the showerhead as well as the horizontal type MOVPE reactors. Poisson–Schrödinger simulations show that for high Ga incorporation in the Al(GaN interlayer, an additional triangular well with very small depth may be exhibited in parallel to the main 2–DEG channel. The presence of this additional channel may cause parasitic conduction and severe issues in device characteristics and processing. Producing a HEMT structure with InAlGaN as the barrier and AlGaN as the interlayer with appropriate alloy composition may be a possible route to optimization, as it might be difficult to avoid Ga incorporation while continuously depositing the layers using the MOVPE growth method. Our present work shows the necessity of a multicharacterization approach to correlate structural and electrical properties to understand device structures and their performance.

  18. Growth of (20 anti 21)AlGaN, GaN and InGaN by metal organic vapor phase epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Ploch, S.; Wernicke, T.; Rass, J.; Pristovsek, M. [TU Berlin, Institut fuer Festkoerperphysik, Hardenbergstr. 36, 10623 Berlin (Germany); Weyers, M. [Ferdinand-Braun-Institut, Leibniz Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Kneissl, M. [TU Berlin, Institut fuer Festkoerperphysik, Hardenbergstr. 36, 10623 Berlin (Germany); Ferdinand-Braun-Institut, Leibniz Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany)

    2012-07-01

    Green InGaN-based laser diodes on (20 anti 21)GaN substrates have recently demonstrated performances exceeding those of conventional (0001) oriented devices. However little is known regarding the growth parameters. We have investigated growth of AlGaN, GaN and InGaN on (20 anti 21)GaN substrates by MOVPE. Smooth GaN layers with a rms roughness <0.5 nm were obtained by low growth temperatures and reactor pressures. The layers exhibit undulations along [10 anti 14] similar to the GaN substrate. AlGaN and InGaN layers exhibit an increased surface roughness. Undulation bunching was observed and attributed to reduced adatom surface mobility due to the binding energy of Al and the low growth temperature for InGaN respectively or strain relaxation. AlGaN and InGaN heterostructures on (20 anti 21)GaN relax by layer tilt accompanied by formation of misfit dislocations, due to shear strain of the unit cell. This relaxation mechanism leads to a reduced critical layer thickness of (20 anti 21)AlGaN layers and InGaN multi quantum wells (MQW) in comparison to (0001). PL spectral broadening of 230 meV of (20 anti 21)InGaN single QWs emitting at 415 nm can be reduced by increased growth temperature or increased number of QWs with reduced thickness.

  19. Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May, E-mail: eekmlau@ust.hk [Photonics Technology Center, Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2015-05-04

    We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme.

  20. AlGaAs and AlGaAs/GaAs/AlGaAs nanowires grown by molecular beam epitaxy on silicon substrates

    DEFF Research Database (Denmark)

    Cirlin, G E; Reznik, R R; Shtrom, I V

    2017-01-01

    The data on growth peculiarities and physical properties of GaAs insertions embedded in AlGaAs nanowires grown on different (1 1 1) substrates by Au-assisted molecular beam epitaxy are presented. The influence of nanowires growth conditions on structural and optical properties is studied in detail...

  1. Properties and Bibliography of GaSe

    Science.gov (United States)

    1994-02-01

    Musaev, A. E. Bakhyshev, N. M. Gasanly and L. G. Musaeva . (1975). "Anisotropy of the optical constants of GaS and GaSe near the absorption edge." Sov...Phys. Semiconductors. 9 94-95 Russian ref.: Fiz. Tekh. Poluprovodn. 9 142-145 (January 1975). Akhundov, G. A., L. G. Musaeva and M. D. Khomutova

  2. Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

    International Nuclear Information System (INIS)

    Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May

    2015-01-01

    We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme

  3. 70Ge, 72Ge, 74Ge, 76Ge(d,3He)69Ga, 71Ga, 73Ga, 75Ga reactions at 26 MeV

    International Nuclear Information System (INIS)

    Rotbard, G.; La Rana, G.; Vergnes, M.; Berrier, G.; Kalifa, J.; Guilbaut, G.; Tamisier, R.

    1978-01-01

    The 70 Ge, 72 Ge, 74 Ge, 76 Ge(d, 3 He) 69 Ga, 71 Ga, 73 Ga, 75 Ga reactions have been studied at 26 MeV with 15 keV resolution (F.W.H.M), using the Orsay MP tandem accelerator and a split pole magnetic spectrometer. The spectroscopic factors are determined for 15 levels in 69 Ga and 11 levels in each of the 3 other Ga isotopes. Level schemes are proposed for the practically unknown 73 Ga and 75 Ga. Very simple model wave functions previously proposed for Ge nuclei are seen to reproduce quite well the measured occupation numbers for the proton orbitals. Anomalies in these occupation numbers are observed between Z=31 and 32 and between N=40 and 42, this last one corresponding to the structural transition observed recently in a comparison of the (p,t) and (t,p) reactions. These anomalies could be related to changes in the nuclear shape

  4. Radiative and non-radiative recombination in GaInN/GaN quantum wells; Strahlende und nichtstrahlende Rekombination in GaInN/GaN-Quantenfilmen

    Energy Technology Data Exchange (ETDEWEB)

    Netzel, C.

    2007-02-08

    The studies presented in this thesis deal with the occurence of V defectsin GaInN/GaN quantum film structures grown by means of organometallic gas phase epitaxy, and the effects, which have the V defects respectively the GaInN quantum films on the V-defect facets on the emission and recombination properties of the whole GaInN/GaN quantum film structure. The V-defects themselves, inverse pyramidal vacancies with hexagonal base in the semiconductor layers, arise under suitable growth conditions around the percussion violations, which extend in lattice-mismatched growth of GaN on the heterosubstrates sapphire or silicon carbide starting in growth direction through the crystal. If GaInN layers are grown over V-defect dispersed layers on the (1-101) facets of the V defects and the (0001) facets, the growth front of the structure, different growth velocities are present, which lead to differently wide GaInN quantum films on each facets.

  5. Interface and transport properties of GaN/graphene junction in GaN-based LEDs

    International Nuclear Information System (INIS)

    Wang Liancheng; Zhang Yiyun; Liu Zhiqiang; Guo Enqing; Yi Xiaoyan; Wang Junxi; Wang Guohong; Li Xiao; Zhu Hongwei

    2012-01-01

    A normalized circular transmission line method pattern with uniform interface area was developed to obtain contact resistances of p-, u-, n-GaN/graphene contacts (p, u and n represent p-type doped, unintentionally doped and n-type doped, respectively) and N-polar u-, n-GaN/graphene contacts in GaN-based LEDs. The resistances of the graphene/GaN contacts were mainly determined by the work function gap and the carrier concentration in GaN. Annealing caused diffusion of metal atoms and significantly influenced the interface transport properties.

  6. Device Performance and Reliability Improvements of AlGaBN/GaN/Si MOSFET

    Science.gov (United States)

    2016-02-04

    AFRL-AFOSR-JP-TR-2016-0037 Device Performance and Reliablity Improvements of AlGaBN/GaN/Si MOSFET Robert Wallace UNIVERSITY OF TEXAS AT DALLAS Final...GaN/Si MOSFET 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-14-1-4069 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Robert Wallace 5d.  PROJECT...AOARD Grant FA2386-14-1-4069 Device Performance and Reliability Improvements of AlGaN/GaN/Si MOSFET US 12 month extension (2014 – 2015) for current

  7. Density of Ga2O3 Liquid

    OpenAIRE

    Dingwell, Donald B.

    1992-01-01

    The density of Ga2O3 liquid in equilibrium with air has been measured at 18000 to 19000C using an Ir double-bob Archimedean method. The data yield the following description of the density of Ga2O3 liquid: ρ= 4.8374(84)–0.00065(12)(T −18500C). This density-temperature relationship is compared with the partial molar volume of Ga2O3 in glasses in the systems CaO–Ga2O3–SiO2 and Na2O–Ga2O3–SiO2, corrected to the glass transition temperature using thermal expansivities. The comparison illustrates t...

  8. Study of 67Ga scan in sarcoidosis

    International Nuclear Information System (INIS)

    Han Lijun; Qu Wanyin; Liu Xiuqin

    1997-01-01

    Gallium scan and serum angiotensin-converting enzyme assay (SACE) were compared in patients with sarcoidosis. The examination of 67 Ga scan, SACE determination, pulmonary function test, chest CT and chest X-ray in 24 cases with sarcoidosis were studied. The results revealed that 4 of 24 cases had obviously high uptake of 67 Ga exceeding hepatic activity (3+) in clinical active stage, 3 patients had resembling the Greek letter lambda, symmetrically located in bilateral hilar lymph nodes, and among them two had an uptake of 67 Ga in the bilateral lacrimal and parotid gland simulating 'Panda Face'. 8 of 20 cases with inactive sarcoidosis had an abnormal 67 Ga scan (1+). In those patients with normal SACE level but increased uptake of 67 Ga, active stage of disease was demonstrated and steroid therapy was indicated. Gallium scan is a valuable method for the staging of its activity and evaluation of the therapeutic effect in the follow-up patients with sarcoidosis

  9. Self-diffusion in 69Ga121Sb/71Ga123Sb isotope heterostructures

    Science.gov (United States)

    Bracht, H.; Nicols, S. P.; Haller, E. E.; Silveira, J. P.; Briones, F.

    2001-05-01

    Gallium and antimony self-diffusion experiments have been performed in undoped 69Ga121Sb/71Ga123Sb isotope heterostructures at temperatures between 571 and 708 °C under Sb- and Ga-rich ambients. Ga and Sb profiles measured with secondary ion mass spectrometry reveal that Ga diffuses faster than Sb by several orders of magnitude. This strongly suggests that the two self-atom species diffuse independently on their own sublattices. Experimental results lead us to conclude that Ga and Sb diffusion are mediated by Ga vacancies and Sb interstitials, respectively, and not by the formation of a triple defect proposed earlier by Weiler and Mehrer [Philos. Mag. A 49, 309 (1984)]. The extremely slow diffusion of Sb up to the melting temperature of GaSb is proposed to be a consequence of amphoteric transformations between native point defects which suppress the formation of those native defects which control Sb diffusion. Preliminary experiments exploring the effect of Zn indiffusion at 550 °C on Ga and Sb diffusion reveal an enhanced intermixing of the Ga isotope layers compared to undoped GaSb. However, under the same conditions the diffusion of Sb was not significantly affected.

  10. A hole modulator for InGaN/GaN light-emitting diodes

    Science.gov (United States)

    Zhang, Zi-Hui; Kyaw, Zabu; Liu, Wei; Ji, Yun; Wang, Liancheng; Tan, Swee Tiam; Sun, Xiao Wei; Demir, Hilmi Volkan

    2015-02-01

    The low p-type doping efficiency of the p-GaN layer has severely limited the performance of InGaN/GaN light-emitting diodes (LEDs) due to the ineffective hole injection into the InGaN/GaN multiple quantum well (MQW) active region. The essence of improving the hole injection efficiency is to increase the hole concentration in the p-GaN layer. Therefore, in this work, we have proposed a hole modulator and studied it both theoretically and experimentally. In the hole modulator, the holes in a remote p-type doped layer are depleted by the built-in electric field and stored in the p-GaN layer. By this means, the overall hole concentration in the p-GaN layer can be enhanced. Furthermore, the hole modulator is adopted in the InGaN/GaN LEDs, which reduces the effective valance band barrier height for the p-type electron blocking layer from ˜332 meV to ˜294 meV at 80 A/cm2 and demonstrates an improved optical performance, thanks to the increased hole concentration in the p-GaN layer and thus the improved hole injection into the MQWs.

  11. A hole modulator for InGaN/GaN light-emitting diodes

    International Nuclear Information System (INIS)

    Zhang, Zi-Hui; Kyaw, Zabu; Liu, Wei; Ji, Yun; Wang, Liancheng; Tan, Swee Tiam; Sun, Xiao Wei; Demir, Hilmi Volkan

    2015-01-01

    The low p-type doping efficiency of the p-GaN layer has severely limited the performance of InGaN/GaN light-emitting diodes (LEDs) due to the ineffective hole injection into the InGaN/GaN multiple quantum well (MQW) active region. The essence of improving the hole injection efficiency is to increase the hole concentration in the p-GaN layer. Therefore, in this work, we have proposed a hole modulator and studied it both theoretically and experimentally. In the hole modulator, the holes in a remote p-type doped layer are depleted by the built-in electric field and stored in the p-GaN layer. By this means, the overall hole concentration in the p-GaN layer can be enhanced. Furthermore, the hole modulator is adopted in the InGaN/GaN LEDs, which reduces the effective valance band barrier height for the p-type electron blocking layer from ∼332 meV to ∼294 meV at 80 A/cm 2 and demonstrates an improved optical performance, thanks to the increased hole concentration in the p-GaN layer and thus the improved hole injection into the MQWs

  12. A comparison of HAART outcomes between the US military HIV Natural History Study (NHS and HIV Atlanta Veterans Affairs Cohort Study (HAVACS.

    Directory of Open Access Journals (Sweden)

    Jodie L Guest

    Full Text Available INTRODUCTION: The Department of Defense (DoD and the Department of Veterans Affairs (VA provide comprehensive HIV treatment and care to their beneficiaries with open access and few costs to the patient. Individuals who receive HIV care in the VA have higher rates of substance abuse, homelessness and unemployment than individuals who receive HIV care in the DoD. A comparison between individuals receiving HIV treatment and care from the DoD and the VA provides an opportunity to explore the impact of individual-level characteristics on clinical outcomes within two healthcare systems that are optimized for clinic retention and medication adherence. METHODS: Data were collected on 1065 patients from the HIV Atlanta VA Cohort Study (HAVACS and 1199 patients from the US Military HIV Natural History Study (NHS. Patients were eligible if they had an HIV diagnosis and began HAART between January 1, 1996 and June 30, 2010. The analysis examined the survival from HAART initiation to all-cause mortality or an AIDS event. RESULTS: Although there was substantial between-cohort heterogeneity and the 12-year survival of participants in NHS was significantly higher than in HAVACS in crude analyses, this survival disparity was reduced from 21.5% to 1.6% (mortality only and 26.8% to 4.1% (combined mortality or AIDS when controlling for clinical and demographic variables. CONCLUSION: We assessed the clinical outcomes for individuals with HIV from two very similar government-sponsored healthcare systems that reduced or eliminated many barriers associated with accessing treatment and care. After controlling for clinical and demographic variables, both 12-year survival and AIDS-free survival rates were similar for the two study cohorts who have open access to care and medication despite dramatic differences in socioeconomic and behavioral characteristics.

  13. Significant inter-observer variation in the diagnosis of extrapancreatic necrosis and type of pancreatic collections in acute pancreatitis - An international multicenter evaluation of the revised Atlanta classification.

    Science.gov (United States)

    Sternby, Hanna; Verdonk, Robert C; Aguilar, Guadalupe; Dimova, Alexandra; Ignatavicius, Povilas; Ilzarbe, Lucas; Koiva, Peeter; Lantto, Eila; Loigom, Tonis; Penttilä, Anne; Regnér, Sara; Rosendahl, Jonas; Strahinova, Vanya; Zackrisson, Sophia; Zviniene, Kristina; Bollen, Thomas L

    2016-01-01

    For consistent reporting and better comparison of data in research the revised Atlanta classification (RAC) proposes new computed tomography (CT) criteria to describe the morphology of acute pancreatitis (AP). The aim of this study was to analyse the interobserver agreement among radiologists in evaluating CT morphology by using the new RAC criteria in patients with AP. Patients with a first episode of AP who obtained a CT were identified and consecutively enrolled at six European centres backwards from January 2013 to January 2012. A local radiologist at each center and a central expert radiologist scored the CTs separately using the RAC criteria. Center dependent and independent interobserver agreement was determined using Kappa statistics. In total, 285 patients with 388 CTs were included. For most CT criteria, interobserver agreement was moderate to substantial. In four categories, the center independent kappa values were fair: extrapancreatic necrosis (EXPN) (0.326), type of pancreatitis (0.370), characteristics of collections (0.408), and appropriate term of collections (0.356). The fair kappa values relate to discrepancies in the identification of extrapancreatic necrotic material. The local radiologists diagnosed EXPN (33% versus 59%, P < 0.0001) and non-homogeneous collections (35% versus 66%, P < 0.0001) significantly less frequent than the central expert. Cases read by the central expert showed superior correlation with clinical outcome. Diagnosis of EXPN and recognition of non-homogeneous collections show only fair agreement potentially resulting in inconsistent reporting of morphologic findings. Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  14. GaN-based ultraviolet light-emitting diodes with AlN/GaN/InGaN multiple quantum wells.

    Science.gov (United States)

    Chang, Hung-Ming; Lai, Wei-Chih; Chen, Wei-Shou; Chang, Shoou-Jinn

    2015-04-06

    We demonstrate indium gallium nitride/gallium nitride/aluminum nitride (AlN/GaN/InGaN) multi-quantum-well (MQW) ultraviolet (UV) light-emitting diodes (LEDs) to improve light output power. Similar to conventional UV LEDs with AlGaN/InGaN MQWs, UV LEDs with AlN/GaN/InGaN MQWs have forward voltages (V(f)'s) ranging from 3.21 V to 3.29 V at 350 mA. Each emission peak wavelength of AlN/GaN/InGaN MQW UV LEDs presents 350 mA output power greater than that of the corresponding emission peak wavelength of AlGaN/InGaN MQW UV LEDs. The light output power at 350mA of AlN/GaN/InGaN MQWs UV LEDs with 375 nm emission wavelength can reach around 26.7% light output power enhancement in magnitude compared to the AlGaN/InGaN MQWs UV LEDs with same emission wavelength. But 350mA light output power of AlN/GaN/InGaN MQWs UV LEDs with emission wavelength of 395nm could only have light output power enhancement of 2.43% in magnitude compared with the same emission wavelength AlGaN/InGaN MQWs UV LEDs. Moreover, AlN/GaN/InGaN MQWs present better InGaN thickness uniformity, well/barrier interface quality and less large size pits than AlGaN/InGaN MQWs, causing AlN/GaN/InGaN MQW UV LEDs to have less reverse leakage currents at -20 V. Furthermore, AlN/GaN/InGaN MQW UV LEDs have the 2-kV human body mode (HBM) electrostatic discharge (ESD) pass yield of 85%, which is 15% more than the 2-kV HBM ESD pass yield of AlGaN/InGaN MQW UV LEDs of 70%.

  15. Clinical evaluation of 67Ga gut accumulation in 67Ga scintigraphy

    International Nuclear Information System (INIS)

    Kobayashi, Hidetoshi; Ohno, Akiko; Watanabe, Youichi; Ishigaki, Takeo.

    1994-01-01

    Accumulation of 67 Ga in gut was evaluated in 67 Ga scintigraphy retrospectively in 30 patients (32 examinations). TIBC and UIBC were examined in all patients on the day when their scintigraphies were performed. Blood transfusion or Fe administration 2 months before 67 Ga scintigraphies were not carried out in any patient. Fifty percents (6/12) of male, and 40% (8/20) of female patients showed 67 Ga accumulation in gut. There was significant correlation between 67 Ga accumulation in gut and low ion-saturation ratio for transferrin. Excretion of 67 Ga bound with transferrin from liver was thought to be an important factor of 67 ga accumulation in gut. (author)

  16. Characteristics of AlGaN/GaN/AlGaN double heterojunction HEMTs with an improved breakdown voltage

    International Nuclear Information System (INIS)

    Ma Juncai; Zhang Jincheng; Xue Junshuai; Lin Zhiyu; Liu Ziyang; Xue Xiaoyong; Ma Xiaohua; Hao Yue

    2012-01-01

    We studied the performance of AlGaN/GaN double heterojunction high electron mobility transistors (DH-HEMTs) with an AlGaN buffer layer, which leads to a higher potential barrier at the backside of the two-dimensional electron gas channel and better carrier confinement. This, remarkably, reduces the drain leakage current and improves the device breakdown voltage. The breakdown voltage of AlGaN/GaN double heterojunction HEMTs (∼100 V) was significantly improved compared to that of conventional AlGaN/GaN HEMTs (∼50 V) for the device with gate dimensions of 0.5 × 100 μm and a gate—drain distance of 1 μm. The DH-HEMTs also demonstrated a maximum output power of 7.78 W/mm, a maximum power-added efficiency of 62.3% and a linear gain of 23 dB at the drain supply voltage of 35 V at 4 GHz. (semiconductor devices)

  17. Quality of runoff from small watersheds in the Twin Cities Metropolitan Area, Minnesota - A project plan

    Science.gov (United States)

    Ayers, M.A.; Payne, G.A.; Oberts, Gary L.

    1980-01-01

    A program of water-quality sampling to define the relationships between land use, watershed characteristics, and the quantity, quality, and timing of runoff has been started for the Twin Cities metropolitan area of Minnesota. Ten major watersheds were chosen as representative of conditions in the metropolitan area. Each will be sampled at one location near the outlet. Six of the watersheds are agricultural and range in size from 14.3 to 82.9 square miles. The four remaining watersheds are urbanized and range in size from 1.22 to 31.7 square miles. In addition, seven urban subwatersheds, which range in size from 0.12 to 0.47 square miles and reflect a dominant land-use type, will be sampled.

  18. Shifting balances in U.S. metropolitan and nonmetropolitan area growth.

    Science.gov (United States)

    Garnick, D H

    1984-12-01

    "This paper assesses some of the recent attempts to explain the perceived growth reversal between metropolitan and nonmetropolitan areas in the United States during the 1970s. The paper argues that the reversal in population trends was not a one-time, radical shift in settlement trends, but rather the result of more continuous underlying industrial trends. Indeed, since 1979, population growth has again become faster in metropolitan than nonmetropolitan areas." The paper includes three sections. Regional and area population and industrial earnings growth patterns are first summarized for the 1960s, 1970s, and 1980s. Theories of polarization and polar reversal are then evaluated and found to be inadequate. Finally, a reconstruction of the neoclassical model is proposed. excerpt

  19. Measures of social segregation in the context of Warsaw, Berlin and Paris metropolitan areas

    Directory of Open Access Journals (Sweden)

    Grzegorczyk Anna

    2015-09-01

    Full Text Available Social segregation is a subject common in contemporary studies of metropolitan areas. Until recently, studies of segregation focused on the distribution of ethnic groups, immigrants, and the poor. Today, they also cover additional indicators such as demographic properties, education, and affiliation with social and professional categories, which can also serve to determine the causes of the segregation (including the self-segregation of the rich. This article aims to point out the measures of segregation that present the segregation levels in the most complete manner, along with their application in the context of three European metropolitan areas: Warsaw, Berlin, and Paris. The first part of the article is a review of the existing approaches to segregation measures, followed by the selection of research method, presentation of the analysis’ results, and evaluation of the applied methods; presenting the opportunities and limitations in research of the social segregation phenomenon.

  20. Seroprevalence of Toxoplasma gondii in domestic pets from metropolitan regions of Panama

    Directory of Open Access Journals (Sweden)

    Rengifo-Herrera Claudia

    2017-01-01

    Full Text Available Toxoplasmosis is a worldwide zoonotic disease but information regarding domestic animals in Central America is scarce and fragmented. The aim of this study was to determine the seroprevalence of Toxoplasma gondii in domestic cats and dogs in different metropolitan regions of Panama. A total of 576 samples were collected; sera from 120 cats and 456 dogs were tested using a commercial indirect enzyme-linked immunosorbent assay (ELISA. The overall seroprevalence of IgG antibodies was 30.73%. There is high seroprevalence of T. gondii in cats and dogs in the metropolitan regions around the Panama Canal; however, differences between these species were not significant. Statistical analysis indicated that there are relevant variables, such as the age of animals, with a direct positive relationship with seroprevalence. None of the variables related to animal welfare (veterinary attention provided, type of dwelling, and access to green areas and drinking water were associated with seropositivity.