An Evidence-Based Review of Impacts, Strategies and Tools to Mitigate Urban Heat Islands

Directory of Open Access Journals (Sweden)

Walter Leal Filho

2017-12-01

Full Text Available The impacts of climate changes on cities, which are home to over half of the world’s population, are already being felt. In many cases, the intensive speed with which urban centres have been growing means that little attention has been paid to the role played by climatic factors in maintaining quality of life. Among the negative consequences of rapid city growth is the expansion of the problems posed by urban heat islands (UHIs, defined as areas in a city that are much warmer than other sites, especially in comparison with rural areas. This paper analyses the consistency of the UHI-related literature in three stages: first it outlines its characteristics and impacts in a wide variety of cities around the world, which poses pressures to public health in many different countries. Then it introduces strategies which may be employed in order to reduce its effects, and finally it analyses available tools to systematize the initial high level assessment of the phenomenon for multidisciplinary teams involved in the urban planning process. The analysis of literature on the characteristics, impacts, strategies and digital tools to assess on the UHI, reveals the wide variety of parameters, methods, tools and strategies analysed and suggested in the different studies, which does not always allow to compare or standardize the diagnosis or solutions.

An Evidence-Based Review of Impacts, Strategies and Tools to Mitigate Urban Heat Islands

Science.gov (United States)

Leal Filho, Walter; Echevarria Icaza, Leyre; Emanche, Victoria Omeche; Quasem Al-Amin, Abul

2017-01-01

The impacts of climate changes on cities, which are home to over half of the world’s population, are already being felt. In many cases, the intensive speed with which urban centres have been growing means that little attention has been paid to the role played by climatic factors in maintaining quality of life. Among the negative consequences of rapid city growth is the expansion of the problems posed by urban heat islands (UHIs), defined as areas in a city that are much warmer than other sites, especially in comparison with rural areas. This paper analyses the consistency of the UHI-related literature in three stages: first it outlines its characteristics and impacts in a wide variety of cities around the world, which poses pressures to public health in many different countries. Then it introduces strategies which may be employed in order to reduce its effects, and finally it analyses available tools to systematize the initial high level assessment of the phenomenon for multidisciplinary teams involved in the urban planning process. The analysis of literature on the characteristics, impacts, strategies and digital tools to assess on the UHI, reveals the wide variety of parameters, methods, tools and strategies analysed and suggested in the different studies, which does not always allow to compare or standardize the diagnosis or solutions. PMID:29257100

Climate Control Load Reduction Strategies for Electric Drive Vehicles in Cold Weather: Preprint

Energy Technology Data Exchange (ETDEWEB)

Jeffers, Matthew; Chaney, Lawrence; Rugh, John

2016-03-31

When operated, the climate control system is the largest auxiliary load on a vehicle. This load has significant impact on fuel economy for conventional and hybrid vehicles, and it drastically reduces the driving range of all electric vehicles (EVs). Heating is even more detrimental to EV range than cooling because no engine waste heat is available. Reducing the thermal loads on the heating, ventilating, and air conditioning system will extend driving range and increase the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have evaluated strategies for vehicle climate control load reduction with special attention toward grid connected electric vehicles. Outdoor vehicle thermal testing and computational modeling were used to assess potential strategies for improved thermal management and to evaluate the effectiveness of thermal load reduction technologies. A human physiology model was also used to evaluate the impact on occupant thermal comfort. Experimental evaluations of zonal heating strategies demonstrated a 5.5% to 28.5% reduction in cabin heating energy over a 20-minute warm-up. Vehicle simulations over various drive cycles show a 6.9% to 18.7% improvement in EV range over baseline heating using the most promising zonal heating strategy investigated. A national-level analysis was conducted to determine the overall national impact. If all vehicles used the best zonal strategy, the range would be improved by 7.1% over the baseline heating range. This is a 33% reduction in the range penalty for heating.

Heat Stress and feeding strategies in meat-type chickens

NARCIS (Netherlands)

Syafwan, W.; Kwakkel, R.P.; Verstegen, M.W.A.

2011-01-01

Heat stress can induce hyperthermia in poultry. A reduction in heat load can be achieved by increasing the possibilities for dissipation, decreasing the level of heat production or by changing the thermal production pattern within a day. Strategies to reduce the negative effects of heat stress can

Urban Heat Island Effect Actions - Neighborhood Data

Data.gov (United States)

Louisville Metro Government — The urban heat island effect — defined as the difference in temperature between the core of Louisville and its suburbs — contributes to heat-related illnesses and...

Modifications of the urban heat island characteristics under exceptionally hot weather - A case study

Science.gov (United States)

Founda, Dimitra; Pierros, Fragiskos; Santamouris, Mathew

2016-04-01

Considerable recent research suggests that heat waves are becoming more frequent, more intense and longer in the future. Heat waves are characterised by the dominance of prolonged abnormally hot conditions related to synoptic scale anomalies, thus they affect extensive geographical areas. Heat waves (HW) have a profound impact on humans and they have been proven to increase mortality. Urban areas are known to be hotter than the surrounding rural areas due to the well documented urban heat island (UHI) phenomenon. Urban areas face increased risk under heat waves, due to the added heat from the urban heat island and increased population density. Given that urban populations keep increasing, citizens are exposed to significant heat related risk. Mitigation and adaptation strategies require a deep understanding of the response of the urban heat islands under extremely hot conditions. The response of the urban heat island under selected episodes of heat waves is examined in the city of Athens, from the comparison between stations of different characteristics (urban, suburban, coastal and rural). Two distinct episodes of heat waves occurring during summer 2000 were selected. Daily maximum air temperature at the urban station of the National Observatory of Athens (NOA) exceeded 40 0C for at least three consecutive days for both episodes. The intensity of UHI during heat waves was compared to the intensity under 'normal' conditions, represented from a period 'before' and 'after' the heat wave. Striking differences of UHI features between HW and no HW cases were observed, depending on the time of the day and the type of station. The comparison between the urban and the coastal station showed an increase of the order of 3 0C in the intensity of UHI during the HW days, as regards both daytime and nighttime conditions. The comparison between urban and a suburban (inland) station, revealed some different behaviour during HWs, with increases of the order of 3 0C in the nocturnal

The role of one large greenspace in mitigating London's nocturnal urban heat island.

Science.gov (United States)

Doick, Kieron J; Peace, Andrew; Hutchings, Tony R

2014-09-15

The term urban heat island (UHI) describes a phenomenon where cities are on average warmer than the surrounding rural area. Trees and greenspaces are recognised for their strong potential to regulate urban air temperatures and combat the UHI. Empirical data is required in the UK to inform predictions on cooling by urban greenspaces and guide planning to maximise cooling of urban populations. We describe a 5-month study to measure the temperature profile of one of central London's large greenspaces and also in an adjacent street to determine the extent to which the greenspace reduced night-time UHI intensity. Statistical modelling displayed an exponential decay in the extent of cooling with increased distance from the greenspace. The extent of cooling ranged from an estimated 20 m on some nights to 440 m on other nights. The mean temperature reduction over these distances was 1.1 °C in the summer months, with a maximum of 4 °C cooling observed on some nights. Results suggest that calculation of London's UHI using Met Stations close to urban greenspace can underestimate 'urban' heat island intensity due to the cooling effect of the greenspace and values could be in the region of 45% higher. Our results lend support to claims that urban greenspace is an important component of UHI mitigation strategies. Lack of certainty over the variables that govern the extent of the greenspace cooling influence indicates that the multifaceted roles of trees and greenspaces in the UK's urban environment merit further consideration. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Reduced Urban Heat Island intensity under warmer conditions

Science.gov (United States)

Scott, Anna A.; Waugh, Darryn W.; Zaitchik, Ben F.

2018-06-01

The Urban Heat Island (UHI), the tendency for urban areas to be hotter than rural regions, represents a significant health concern in summer as urban populations are exposed to elevated temperatures. A number of studies suggest that the UHI increases during warmer conditions, however there has been no investigation of this for a large ensemble of cities. Here we compare urban and rural temperatures in 54 US cities for 2000–2015 and show that the intensity of the Urban Heat Island, measured here as the differences in daily-minimum or daily-maximum temperatures between urban and rural stations or ΔT, in fact tends to decrease with increasing temperature in most cities (38/54). This holds when investigating daily variability, heat extremes, and variability across climate zones and is primarily driven by changes in rural areas. We relate this change to large-scale or synoptic weather conditions, and find that the lowest ΔT nights occur during moist weather conditions. We also find that warming cities have not experienced an increasing Urban Heat Island effect.

Coupling Analysis of Heat Island Effects, Vegetation Coverage and Urban Flood in Wuhan

Science.gov (United States)

Liu, Y.; Liu, Q.; Fan, W.; Wang, G.

2018-04-01

In this paper, satellite image, remote sensing technique and geographic information system technique are main technical bases. Spectral and other factors comprehensive analysis and visual interpretation are main methods. We use GF-1 and Landsat8 remote sensing satellite image of Wuhan as data source, and from which we extract vegetation distribution, urban heat island relative intensity distribution map and urban flood submergence range. Based on the extracted information, through spatial analysis and regression analysis, we find correlations among heat island effect, vegetation coverage and urban flood. The results show that there is a high degree of overlap between of urban heat island and urban flood. The area of urban heat island has buildings with little vegetation cover, which may be one of the reasons for the local heavy rainstorms. Furthermore, the urban heat island has a negative correlation with vegetation coverage, and the heat island effect can be alleviated by the vegetation to a certain extent. So it is easy to understand that the new industrial zones and commercial areas which under constructions distribute in the city, these land surfaces becoming bare or have low vegetation coverage, can form new heat islands easily.

Avoided heat-related mortality through climate adaptation strategies in three US cities.

Science.gov (United States)

Stone, Brian; Vargo, Jason; Liu, Peng; Habeeb, Dana; DeLucia, Anthony; Trail, Marcus; Hu, Yongtao; Russell, Armistead

2014-01-01

Heat-related mortality in US cities is expected to more than double by the mid-to-late 21st century. Rising heat exposure in cities is projected to result from: 1) climate forcings from changing global atmospheric composition; and 2) local land surface characteristics responsible for the urban heat island effect. The extent to which heat management strategies designed to lessen the urban heat island effect could offset future heat-related mortality remains unexplored in the literature. Using coupled global and regional climate models with a human health effects model, we estimate changes in the number of heat-related deaths in 2050 resulting from modifications to vegetative cover and surface albedo across three climatically and demographically diverse US metropolitan areas: Atlanta, Georgia, Philadelphia, Pennsylvania, and Phoenix, Arizona. Employing separate health impact functions for average warm season and heat wave conditions in 2050, we find combinations of vegetation and albedo enhancement to offset projected increases in heat-related mortality by 40 to 99% across the three metropolitan regions. These results demonstrate the potential for extensive land surface changes in cities to provide adaptive benefits to urban populations at risk for rising heat exposure with climate change.

Avoided heat-related mortality through climate adaptation strategies in three US cities.

Directory of Open Access Journals (Sweden)

Brian Stone

Full Text Available Heat-related mortality in US cities is expected to more than double by the mid-to-late 21st century. Rising heat exposure in cities is projected to result from: 1 climate forcings from changing global atmospheric composition; and 2 local land surface characteristics responsible for the urban heat island effect. The extent to which heat management strategies designed to lessen the urban heat island effect could offset future heat-related mortality remains unexplored in the literature. Using coupled global and regional climate models with a human health effects model, we estimate changes in the number of heat-related deaths in 2050 resulting from modifications to vegetative cover and surface albedo across three climatically and demographically diverse US metropolitan areas: Atlanta, Georgia, Philadelphia, Pennsylvania, and Phoenix, Arizona. Employing separate health impact functions for average warm season and heat wave conditions in 2050, we find combinations of vegetation and albedo enhancement to offset projected increases in heat-related mortality by 40 to 99% across the three metropolitan regions. These results demonstrate the potential for extensive land surface changes in cities to provide adaptive benefits to urban populations at risk for rising heat exposure with climate change.

Mitigating the Urban Heat Island Effect in Megacity Tehran

Directory of Open Access Journals (Sweden)

Sahar Sodoudi

2014-01-01

Full Text Available Cities demonstrate higher nocturnal temperatures than surrounding rural areas, which is called “urban heat island” (UHI effect. Climate change projections also indicate increase in the frequency and intensity of heat waves, which will intensify the UHI effect. As megacity Tehran is affected by severe heatwaves in summer, this study investigates its UHI characteristics and suggests some feasible mitigation strategies in order to reduce the air temperature and save energy. Temperature monitoring in Tehran shows clear evidence of the occurrence of the UHI effect, with a peak in July, where the urban area is circa 6 K warmer than the surrounding areas. The mobile measurements show a park cool island of 6-7 K in 2 central parks, which is also confirmed by satellite images. The effectiveness of three UHI mitigation strategies high albedo material (HAM, greenery on the surface and on the roofs (VEG, and a combination of them (HYBRID has been studied using simulation with the microscale model ENVI-met. All three strategies show higher cooling effect in the daytime. The average nocturnal cooling effect of VEG and HYBRID (0.92, 1.10 K is much higher than HAM (0.16 K, although high-density trees show a negative effect on nocturnal cooling.

Distributed Strategy for Optimal Dispatch of Unbalanced Three-Phase Islanded Microgrids

DEFF Research Database (Denmark)

Vergara Barrios, Pedro Pablo; Rey-López, Juan Manuel; Shaker, Hamid Reza

2018-01-01

This paper presents a distributed strategy for the optimal dispatch of islanded microgrids, modeled as unbalanced three-phase electrical distribution systems (EDS). To set the dispatch of the distributed generation (DG) units, an optimal generation problem is stated and solved distributively based......-phase microgrid. According to the obtained results, the proposed strategy achieves a lower cost solution when compared with a centralized approach based on a static droop framework, with a considerable reduction on the communication system complexity. Additionally, it corrects the mismatch between generation...

Emission operational strategy for combined cooling, heating, and power systems

International Nuclear Information System (INIS)

Fumo, Nelson; Mago, Pedro J.; Chamra, Louay M.

2009-01-01

Integrated Energy Systems (IES), as technology that use thermal activated components to recover waste heat, are energy systems that offer key solution to global warming and energy security through high overall energy efficiency and better fuel use. Combined Cooling, Heating, and Power (CCHP) Systems are IES that use recovered thermal energy from the prime mover to produce heating and cooling for the building. The CCHP operational strategy is critical and it has to be considered in a well designed system since it defines the ultimate goal for the benefits expected from the system. One of the most common operational strategies is the cost-oriented strategy, which allows the system to operate at the lowest cost. A primary energy strategy (PES) optimizes energy consumption instead of cost. However, as a result of the worldwide concern about global warming, projects that target reduction of greenhouse gas (GHG) emissions have gained a lot of interest. Therefore, for a CCHP system, an emission strategy (ES) would be an operational strategy oriented to minimize emission of pollutants. In this study, the use of an ES is proposed for CCHP systems targeted to reduce emission of pollutants. The primary energy consumption (PEC) reduction and carbon dioxide (CO 2 ) emission reduction obtained using the proposed ES are compared with results obtained from the use of a PES. Results show that lower emission of CO 2 is achieved with the ES when compared with the PES, which prove the advantage of the ES for the design of CCHP systems targeted to emissions reduction.

Energy saving and emission reduction of China's urban district heating

International Nuclear Information System (INIS)

Chen, Xia; Wang, Li; Tong, Lige; Sun, Shufeng; Yue, Xianfang; Yin, Shaowu; Zheng, Lifang

2013-01-01

China's carbon dioxide (CO 2 ) emission ranks highest in the world. China is committed to reduce its CO 2 emission by 40% to 45% from the 2005 levels by 2020. To fulfill the target, China's CO 2 emission reduction must exceed 6995 million tons. Energy consumption and CO 2 emission of China's urban district heating (UDH) are increasing. The current policy implemented to improve UDH focuses on replacing coal with natural gas to reduce energy consumption and CO 2 emission to some extent. This paper proposes that heat pump heating (HPH) could serve as a replacement for UDH to help realize energy-saving and emission-reduction goals to a greater extent. The paper also analyzes the impact of this replacement on the heating and power generation sectors. The results show that replacing coal-based UDH with HPH decreases energy consumption and CO 2 emission by 43% in the heating sector. In the power generation sector, the efficiency of power generation at the valley electricity time increases by 0.512%, and the ratio of peak–valley difference decreases by 16.5%. The decreases in CO 2 emission from the heating and power generation sectors cumulatively account for 5.55% of China's total CO 2 emission reduction target in 2020. - Highlights: ► Replacing urban district heating with heat pump heating. ► Impact of heat pump heating on heating and power generation sectors. ► Potential of energy saving and emission reduction for heat pump heating. ► China should adjust current urban heating strategy

Cool city as a sustainable example of heat island management case study of the coolest city in the world

Directory of Open Access Journals (Sweden)

Reeman Mohammed Rehan

2016-08-01

Full Text Available Urbanization negatively impacts the urban environment mainly by the production of waste heat from refrigeration systems, although industrial processes and motorized vehicular traffic have also been recognized as additional causes of the urban heat island (UHI effect. The UHI negatively impacts the residents, with spillover effects for environmental aspects. In urbanized areas, it is a critical factor for air quality management and public health. The UHI and strategies to implement its mitigation are becoming increasingly important for governmental agencies and researchers. The problem is how to deal with UHI effects? Accordingly, the main aim of this paper is to determine the UHI mitigation strategies and their effectiveness in terms of cooling and temperature reduction in cities at the level of urban design. This goal is achieved through exploring the concept of the cool city, as it is the key factor, from the theoretical, analytical, and practical viewpoints, to diminishing the urban heat release. Then, the paper analyzes how the concept of the coolest city in the world (Stuttgart, Germany is developed and explores a practical approach toward cool cities. Finally, it suggests a set of recommendations to develop the urban environment in Greater Cairo by applying the cool city concept.

PMU Measurement-Based Intelligent Strategy for Power System Controlled Islanding

Directory of Open Access Journals (Sweden)

Yi Tang

2018-01-01

Full Text Available Controlled islanding is an effective remedy to prevent large-area blackouts in a power system under a critically unstable condition. When and where to separate the power system are the essential issues facing controlled islanding. In this paper, both tasks are studied to ensure higher time efficiency and a better post-splitting restoration effect. A transient stability assessment model based on extreme learning machine (ELM and trajectory fitting (TF is constructed to determine the start-up criterion for controlled islanding. This model works through prompt stability status judgment with ELM and selective result amendment with TF to ensure that the assessment is both efficient and accurate. Moreover, a splitting surface searching algorithm, subject to minimal power disruption, is proposed for determination of the controlled islanding implementing locations. A highlight of this algorithm is a proposed modified electrical distance concept defined by active power magnitude and reactance on transmission lines that realize a computational burden reduction without feasible solution loss. Finally, the simulation results and comparison analysis based on the New England 39-bus test system validates the implementation effects of the proposed controlled islanding strategy.

Satellite air temperature estimation for monitoring the canopy layer heat island of Milan

DEFF Research Database (Denmark)

Pichierri, Manuele; Bonafoni, Stefania; Biondi, Riccardo

2012-01-01

across the city center from June to September confirming that, in Milan, urban heating is not an occasional phenomenon. Furthermore, this study shows the utility of space missions to monitor the metropolis heat islands if they are able to provide nighttime observations when CLHI peaks are generally......In this work, satellite maps of the urban heat island of Milan are produced using satellite-based infrared sensor data. For this aim, we developed suitable algorithms employing satellite brightness temperatures for the direct air temperature estimation 2 m above the surface (canopy layer), showing...... 2007 and 2010 were processed. Analysis of the canopy layer heat island (CLHI) maps during summer months reveals an average heat island effect of 3–4K during nighttime (with some peaks around 5K) and a weak CLHI intensity during daytime. In addition, the satellite maps reveal a well defined island shape...

Vulnerability to Urban Heat Island in São Paulo Municipality: An Approach to Support the Mitigation Measures Implementation in Urban Planning

Directory of Open Access Journals (Sweden)

Juliana Siqueira-Gay

2017-10-01

Full Text Available In the practice of urban and environmental planning, especially in the context of adaptation to environmental changes, there is a demand for studies that integrate social, economic and environmental information of the population and related risk. Particularly in large urban centers, waterproofing and verticalization have the potential to increase local air temperature, triggering the phenomenon of heat islands. Therefore, this phenomenon has side effects such as public health problems, pollution and changes in the air circulation. In view of the risks and consequences of the urban heat islands, this paper aims to analyze the priority areas for implementing measures to mitigate the effects of the urban heat islands phenomenon in São Paulo City (Brazil. A vulnerability index was proposed considering the social and environmental dimensions, relating the capacity of adaptation, sensitivity and exposure to the occurrence of the phenomenon of urban heat islands. Besides that, measures to mitigate the effects associated with heat islands in urban planning were identified. The central regions are critical for exposure and the outskirts, for adaptive capacity and sensitivity, both considered priorities for the implementation of mitigation measures. In addition, strategies such as implementation and conservation of green spaces, preservation of water bodies, urban design change, as well as use of materials with high reflectance are also listed and partially foreseen in the Municipal Strategic Master Plan to mitigate the effects of urban heat island.

The urban heat island and its impact on heat waves and human health in Shanghai.

Science.gov (United States)

Tan, Jianguo; Zheng, Youfei; Tang, Xu; Guo, Changyi; Li, Liping; Song, Guixiang; Zhen, Xinrong; Yuan, Dong; Kalkstein, Adam J; Li, Furong

2010-01-01

With global warming forecast to continue into the foreseeable future, heat waves are very likely to increase in both frequency and intensity. In urban regions, these future heat waves will be exacerbated by the urban heat island effect, and will have the potential to negatively influence the health and welfare of urban residents. In order to investigate the health effects of the urban heat island (UHI) in Shanghai, China, 30 years of meteorological records (1975-2004) were examined for 11 first- and second-order weather stations in and around Shanghai. Additionally, automatic weather observation data recorded in recent years as well as daily all-cause summer mortality counts in 11 urban, suburban, and exurban regions (1998-2004) in Shanghai have been used. The results show that different sites (city center or surroundings) have experienced different degrees of warming as a result of increasing urbanization. In turn, this has resulted in a more extensive urban heat island effect, causing additional hot days and heat waves in urban regions compared to rural locales. An examination of summer mortality rates in and around Shanghai yields heightened heat-related mortality in urban regions, and we conclude that the UHI is directly responsible, acting to worsen the adverse health effects from exposure to extreme thermal conditions.

The impact of heat waves on surface urban heat island and local economy in Cluj-Napoca city, Romania

Science.gov (United States)

Herbel, Ioana; Croitoru, Adina-Eliza; Rus, Adina Viorica; Roşca, Cristina Florina; Harpa, Gabriela Victoria; Ciupertea, Antoniu-Flavius; Rus, Ionuţ

2017-07-01

The association between heat waves and the urban heat island effect can increase the impact on environment and society inducing biophysical hazards. Heat stress and their associated public health problems are among the most frequent. This paper explores the heat waves impact on surface urban heat island and on the local economy loss during three heat periods in Cluj-Napoca city in the summer of 2015. The heat wave events were identified based on daily maximum temperature, and they were divided into three classes considering the intensity threshold: moderate heat waves (daily maximum temperature exceeding the 90th percentile), severe heat waves (daily maximum temperature over the 95th percentile), and extremely severe heat waves (daily maximum temperature exceeding the 98th percentile). The minimum length of an event was of minimum three consecutive days. The surface urban heat island was detected based on land surface temperature derived from Landsat 8 thermal infrared data, while the economic impact was estimated based on data on work force structure and work productivity in Cluj-Napoca derived from the data released by Eurostat, National Bank of Romania, and National Institute of Statistics. The results indicate that the intensity and spatial extension of surface urban heat island could be governed by the magnitude of the heat wave event, but due to the low number of satellite images available, we should consider this information only as preliminary results. Thermal infrared remote sensing has proven to be a very efficient method to study surface urban heat island, due to the fact that the synoptic conditions associated with heat wave events usually favor cloud free image. The resolution of the OLI_TIRS sensor provided good results for a mid-extension city, but the low revisiting time is still a drawback. The potential economic loss was calculated for the working days during heat waves and the estimated loss reached more than 2.5 mil. EUR for each heat wave day

Study of the heat island phenomenon in large cities and the measures to prevent it; Daitoshi ni okeru heat island gensho to sono taisaku ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Kawasaki, T.; Ishitani, H.; Matsuhashi, T. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

1997-01-30

The paper made an analysis of the heat island phenomenon in the Kanto area using 3-D numerical analysis models and a study on the effectiveness of the measures to prevent it. The models are composed of advection/diffusion models of heat/steam in the wind-velocity field and atmospheric air, heat diffusion models in the underground and undersea, and heat balance models on the ground surface and sea surface. In the calculation, a simulation was conducted of the case of taking the following three measures: the case where the exhaust heat was reduced 30% in the assumed typical day of summer; the case where the heat volume of buildings/trunk roads was reduced; the case where the evaporation efficiency of buildings/trunk roads was raised. The result of the study was as follows: The reduction effect of the exhaust heat is totally large, but precisely observing, some meshes contrarily showed rises in temperature in the suburbs. Also in the case of reducing the heat volume, the same phenomenon occurred, but the effect was large in the center of a city. It was found that the effect was unexpectedly large in the case of increasing the evaporation efficiency. 7 refs., 14 figs., 2 tabs.

Monitoring of urban heat island over Shenzhen, China using remotely sensed measurements

Science.gov (United States)

Wang, Weimin; Hong, Liang; Yang, Lijun; He, Lihuan; Dong, Guihua

2016-05-01

In the past three decades, the Shenzhen city, which is located in south of China, has experienced a rapid urbanization process characterized by sharp decrease in farmland and increases in urban area. This rapid urbanization is one of the main causes of many environmental and ecological problems including urban heat island (UHI). Therefore, the monitoring of rapid urbanization regions and the environment is of critical importance for their sustainable development. In this study, Landsat-8 OLI and TIR images, which were acquired on 2013, are used to monitor urban heat island. After radiometric calibration and atmospheric correction with a simplified method for the atmospheric correction (SMAC) are applied to OLI image, an index-based build-up index (IBI), which is based on the soil adjusted vegetation index (SAVI), the modified normalized difference water index (MNDWI) and the normalized difference built-up index (NDBI), is employed to extract the build-up land features with a given thresholds. A single-channel algorithm is used to retrieve land surface temperature while the land surface emissivity is derived from a normalized differential vegetation index (NDVI) thresholds method. Surface urban heat island index (SUHII) and urban heat island ratio index (URI) are computed for ten districts of Shenzhen based on build-up land distribution and land surface temperature data. A correlation analysis is conducted between heat island index (including SUHII and URI) and socio-economic statistics (including total population and population density) also are included in this analysis. The results show that, a weak relationship between urban heat island and socio-economic statistics are found.

The urban heat island effect, its causes, and mitigation, with reference to the thermal properties of asphalt concrete.

Science.gov (United States)

Mohajerani, Abbas; Bakaric, Jason; Jeffrey-Bailey, Tristan

2017-07-15

The Urban Heat Island (UHI) is a phenomenon that affects many millions of people worldwide. The higher temperatures experienced in urban areas compared to the surrounding countryside has enormous consequences for the health and wellbeing of people living in cities. The increased use of manmade materials and increased anthropogenic heat production are the main causes of the UHI. This has led to the understanding that increased urbanisation is the primary cause of the urban heat island. The UHI effect also leads to increased energy needs that further contribute to the heating of our urban landscape, and the associated environmental and public health consequences. Pavements and roofs dominate the urban surface exposed to solar irradiation. This review article outlines the contribution that pavements make to the UHI effect and analyses localized and citywide mitigation strategies against the UHI. Asphalt Concrete (AC) is one of the most common pavement surfacing materials and is a significant contributor to the UHI. Densely graded AC has low albedo and high volumetric heat capacity, which results in surface temperatures reaching upwards of 60 °C on hot summer days. Cooling the surface of a pavement by utilizing cool pavements has been a consistent theme in recent literature. Cool pavements can be reflective or evaporative. However, the urban geometry and local atmospheric conditions should dictate whether or not these mitigation strategies should be used. Otherwise both of these pavements can actually increase the UHI effect. Increasing the prevalence of green spaces through the installation of street trees, city parks and rooftop gardens has consistently demonstrated a reduction in the UHI effect. Green spaces also increase the cooling effect derived from water and wind sources. This literature review demonstrates that UHI mitigation techniques are best used in combination with each other. As a result of the study, it was concluded that the current mitigation

Heat transport in the quasi-single-helicity islands of EXTRAP T2R

Science.gov (United States)

Frassinetti, L.; Brunsell, P. R.; Drake, J.

2009-03-01

The heat transport inside the magnetic island generated in a quasi-single-helicity regime of a reversed-field pinch device is studied by using a numerical code that simulates the electron temperature and the soft x-ray emissivity. The heat diffusivity χe inside the island is determined by matching the simulated signals with the experimental ones. Inside the island, χe turns out to be from one to two orders of magnitude lower than the diffusivity in the surrounding plasma, where the magnetic field is stochastic. Furthermore, the heat transport properties inside the island are studied in correlation with the plasma current and with the amplitude of the magnetic fluctuations.

Urban Heat Islands and Their Mitigation vs. Local Impacts of Climate Change

Science.gov (United States)

Taha, H.

2007-12-01

Urban heat islands and their mitigation take on added significance, both negative and positive, when viewed from a climate-change perspective. In negative terms, urban heat islands can act as local exacerbating factors, or magnifying lenses, to the effects of regional and large-scale climate perturbations and change. They can locally impact meteorology, energy/electricity generation and use, thermal environment (comfort and heat waves), emissions of air pollutants, photochemistry, and air quality. In positive terms, on the other hand, mitigation of urban heat islands (via urban surface modifications and control of man-made heat, for example) can potentially have a beneficial effect of mitigating the local negative impacts of climate change. In addition, mitigation of urban heat islands can, in itself, contribute to preventing regional and global climate change, even if modestly, by helping reduce CO2 emissions from power plants and other sources as a result of decreased energy use for cooling (both direct and indirect) and reducing the rates of meteorology-dependent emissions of air pollutants. This presentation will highlight aspects and characteristics of heat islands, their mitigation, their modeling and quantification techniques, and recent advances in meso-urban modeling of California (funded by the California Energy Commission). In particular, the presentation will focus on results from quantitative, modeling-based analyses of the potential benefits of heat island mitigation in 1) reducing point- and area-source emissions of CO2, NOx, and VOC as a result of reduced cooling energy demand and ambient/surface temperatures, 2) reducing evaporative and fugitive hydrocarbon emissions as a result of lowered temperatures, 3) reducing biogenic hydrocarbon emissions from existing vegetative cover, 4) slowing the rates of tropospheric/ground-level ozone formation and/or accumulation in the urban boundary layer, and 5) helping improve air quality. Quantitative estimates

Global Urban Heat Island (UHI) Data Set, 2013

Data.gov (United States)

National Aeronautics and Space Administration — The Urban Heat Island (UHI) effect represents the relatively higher temperatures found in urban areas compared to surrounding rural areas owing to higher proportions...

The urban heat island dynamics during heat waves: a study of cities in the United States

Science.gov (United States)

Hu, Leiqiu

2016-04-01

The urban heat island (UHI) is a common phenomenon describing that metropolitan areas are usually warmer than their rural surroundings. This effect is compounded by extreme heat events, which are a leading cause of weather-related human mortality in many countries worldwide. However, the spatial and diurnal variability of temperature and humidity in urban and adjacent rural areas during extreme heat events is not well measured and therefore not well understood. The recently developed dataset of near-surface air and dew temperature from MODIS atmospheric profiles and the new method for the UHI quantification--urban heat island curve are used to quantify the urban climatic changes during heat waves in cities of the United States. The enhanced and weakened UHIs are observed in various cities. The causes of UHI changes during heat waves are discussed, including climate region, vegetation type and amount, city geolocation, etc.

An energy and mortality impact assessment of the urban heat island in the US

International Nuclear Information System (INIS)

Lowe, Scott A.

2016-01-01

Increased summer energy use and increased summer heat related mortality are the two most cited detrimental impacts of the urban heat island (UHI). An assessment of these impacts was made that considered the annual impact of the UHI, not just the summer impact. It was found that in north of the US there was a net decrease in energy use from the UHI, as heating energy reductions were larger than the increase in cooling energy. In the south there was a net energy increase from the UHI. The impact of the UHI on heat related deaths was an estimated increase of 1.1 deaths per million people. The impact of the UHI on cold related deaths was an estimated decrease of 4.0 deaths per million people. These estimates are caveated by the acknowledgement that compounding factors influence mortality. Hypothermia related death rates were three times higher in rural areas than urban areas. This is surprising as the homeless population is usually considered the most at risk, yet they mostly live in urban areas. - Highlights: • The urban heat island (UHI) may actually be beneficial in colder cities in the US in terms of energy use • The UHI may cause an increase in heat related mortality of ~ 1 deaths per million • In winter the UHI may decrease cold related mortality by ~ 4 deaths per million • Cold related death rates were 3 times higher in rural areas although the homeless population live mainly in urban areas

An energy and mortality impact assessment of the urban heat island in the US

Energy Technology Data Exchange (ETDEWEB)

Lowe, Scott A., E-mail: Scott.lowe@manhattan.edu

2016-01-15

Increased summer energy use and increased summer heat related mortality are the two most cited detrimental impacts of the urban heat island (UHI). An assessment of these impacts was made that considered the annual impact of the UHI, not just the summer impact. It was found that in north of the US there was a net decrease in energy use from the UHI, as heating energy reductions were larger than the increase in cooling energy. In the south there was a net energy increase from the UHI. The impact of the UHI on heat related deaths was an estimated increase of 1.1 deaths per million people. The impact of the UHI on cold related deaths was an estimated decrease of 4.0 deaths per million people. These estimates are caveated by the acknowledgement that compounding factors influence mortality. Hypothermia related death rates were three times higher in rural areas than urban areas. This is surprising as the homeless population is usually considered the most at risk, yet they mostly live in urban areas. - Highlights: • The urban heat island (UHI) may actually be beneficial in colder cities in the US in terms of energy use • The UHI may cause an increase in heat related mortality of ~ 1 deaths per million • In winter the UHI may decrease cold related mortality by ~ 4 deaths per million • Cold related death rates were 3 times higher in rural areas although the homeless population live mainly in urban areas.

Infinitary Combinatory Reduction Systems: Normalising Reduction Strategies

NARCIS (Netherlands)

Ketema, J.; Simonsen, Jakob Grue

2010-01-01

We study normalising reduction strategies for infinitary Combinatory Reduction Systems (iCRSs). We prove that all fair, outermost-fair, and needed-fair strategies are normalising for orthogonal, fully-extended iCRSs. These facts properly generalise a number of results on normalising strategies in

Using Cool Roofs to Reduce Energy Use, Greenhouse Gas Emissions, and Urban Heat-island Effects: Findings from an India Experiment

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hashem; Xu, Tengfang; Taha, Haider; Wray, Craig; Sathaye, Jayant; Garg, Vishal; Tetali, Surekha; Babu, M. Hari; Reddy, K. Niranjan

2011-05-25

energy in India. Meteorological simulations in this study indicated that a reduction of 2C in air temperature in the Hyderabad area would be likely if a combination of increased surface albedo and vegetative cover are used as urban heat-island control strategies. In addition, air-temperature reductions on the order of 2.5-3.5C could be achieved if moderate and aggressive heat-island mitigation measures are adopted, respectively. A large-scale deployment of mitigation measures can bring additional indirect benefit to the urban area. For example, cooling outside air can improve the efficiency of cooling systems, reduce smog and greenhouse gas (GHG) emissions, and indirectly reduce pollution from power plants - all improving environmental health quality. This study has demonstrated the effectiveness of cool-roof technology as one of the urban heat-island control strategies for the Indian industrial and scientific communities and has provided an estimate of the national energy savings potential of cool roofs in India. These outcomes can be used for developing cool-roof building standards and related policies in India. Additional field studies, built upon the successes and lessons learned from this project, may be helpful to further confirm the scale of potential energy savings from the application of cooler roofs in various regions of India. In the future, a more rigorous meteorological simulation using urbanized (meso-urban) meteorological models should be conducted, which may produce a more accurate estimate of the air-temperature reductions for the entire urban area.

Coastal management strategy for small island: ecotourism potency development in Karimata Island, West Kalimantan

Science.gov (United States)

Rudiastuti, A. W.; Munawaroh; Setyawan, I. E.; Pramono, G. H.

2018-04-01

Sustainable coastal management is playing an important role in coastal resources conservation, particularly on small islands. Karimata archipelago has unique characteristics and great potential to be developed as a tourism object, one of which is Karimata Island as the largest island and also reserve area. The concept of ecotourism focuses on the ecology conservation, economic benefits, and social life. Ecotourism aims to build sustainable tourism that provides economically viable and social benefits to the community. This study aims to develop coastal management strategy based on ecotourism at Karimata Island. Spatial approaching through coastal type was done. Qualitative descriptive analysis and SWOT are used to develop sustainable management strategies for the coast of Karimata Island, where the opportunities and challenges to the development of coastal ecotourism Karimata Island also included. If this potential is optimally utilized, it can be relied as an economic opportunity for local communities. Structurally shaped coast, marine depositional coast and coast build by organism are several of coastal types found at Karimata Island. Coastal ecosystems inhabited Karimata Island are mangroves, coral reefs, and macro-algae. Karimata Island have not been optimally utilized for tourist destinations. The biggest obstacle encountered is the accessibility from Kalimantan or other island at Karimata islands. Several problems related to the utilization of coastal resources were found such as mangrove and coral reef damage, also regulation that less supportive. The results of this study are expected to provide an overview of solutions for the development of coastal tourism potentials in Karimata Island.

Validation of a Fast-Response Urban Micrometeorological Model to Assess the Performance of Urban Heat Island Mitigation Strategies

Science.gov (United States)

Nadeau, D.; Girard, P.; Overby, M.; Pardyjak, E.; Stoll, R., II; Willemsen, P.; Bailey, B.; Parlange, M. B.

2015-12-01

Urban heat islands (UHI) are a real threat in many cities worldwide and mitigation measures have become a central component of urban planning strategies. Even within a city, causes of UHI vary from one neighborhood to another, mostly due the spatial variability in surface thermal properties, building geometry, anthropogenic heat flux releases and vegetation cover. As a result, the performance of UHI mitigation measures also varies in space. Hence, there is a need to develop a tool to quantify the efficiency of UHI mitigation measures at the neighborhood scale. The objective of this ongoing study is to validate the fast-response micrometeorological model QUIC EnvSim (QES). This model can provide all information required for UHI studies with a fine spatial resolution (up to 0.5m) and short computation time. QES combines QUIC, a CFD-based wind solver and dispersion model, and EnvSim, composed of a radiation model, a land-surface model and a turbulent transport model. Here, high-resolution (1 m) simulations are run over a subset of the École Polytechnique Fédérale de Lausanne (EPFL) campus including complex buildings, various surfaces properties and vegetation. For nearly five months in 2006-07, a dense network of meteorological observations (92 weather stations over 0.1 km2) was deployed over the campus and these unique data are used here as a validation dataset. We present validation results for different test cases (e.g., sunny vs cloudy days, different incoming wind speeds and directions) and explore the effect of a few UHI mitigation strategies on the spatial distribution of near-surface air temperatures. Preliminary results suggest that QES may be a valuable tool in decision-making regarding adaptation of urban planning to UHI.

Urban and regional heat island adaptation measures in the Netherlands

Directory of Open Access Journals (Sweden)

Leyre Echevarria Icaza

2017-11-01

Full Text Available The urban planner´s role should be adapted to the current globalised and overspecialised economic and environmental context, envisioning a balance at the regional scale, apprehending not only new technologies, but also new mapping principles, that allow obtaining multidisciplinary integral overviews since the preliminary stages of the design process. The urban heat Island (UHI is one of the main phenomena affecting the urban climate. In the Netherlands, during the heat wave of 2006, more than 1,000 extra deaths were registered. UHI-related parameters are an example of new elements that should be taken into consideration since the early phases of the design process. Problem statement Thus, the development of urban design guidelines to reduce the heat islands in Dutch cities and regions requires first an overall reflection on the heat island phenomenom (relevance of the large scale assessment, existing tools, instruments and proposal of integrative and catalysing mapping strategies and then a specific assessment of the phenomenom at the selected locations in The Netherlands (testing those principles. Main research question Could the use of satellite imagery help analyse the UHI in the Netherlands and contribute to suggest catalysing mitigation acions actions implementable in the existing urban context of the cities, regions and provinces assessed? Method The development of urban design principles that aim at reaching a physical balance at the regional scale is critical to ensure a reduction of the UHI effect. Landsat and Modis satellite imagery can be analysed and processed using ATCOR 2/3, ENVI 4.7 and GIS, allowing not only a neighbourhood, city and regional scale assessment, but also generating holistic catalysing mapping typologies: game-board, rhizome, layering and drift, which are critical to ensure the integration of all parameters. The scientific inputs need to be combined not only with other disciplines but often also with existing urban

Surface urban heat island across 419 global big cities.

Science.gov (United States)

Peng, Shushi; Piao, Shilong; Ciais, Philippe; Friedlingstein, Pierre; Ottle, Catherine; Bréon, François-Marie; Nan, Huijuan; Zhou, Liming; Myneni, Ranga B

2012-01-17

Urban heat island is among the most evident aspects of human impacts on the earth system. Here we assess the diurnal and seasonal variation of surface urban heat island intensity (SUHII) defined as the surface temperature difference between urban area and suburban area measured from the MODIS. Differences in SUHII are analyzed across 419 global big cities, and we assess several potential biophysical and socio-economic driving factors. Across the big cities, we show that the average annual daytime SUHII (1.5 ± 1.2 °C) is higher than the annual nighttime SUHII (1.1 ± 0.5 °C) (P < 0.001). But no correlation is found between daytime and nighttime SUHII across big cities (P = 0.84), suggesting different driving mechanisms between day and night. The distribution of nighttime SUHII correlates positively with the difference in albedo and nighttime light between urban area and suburban area, while the distribution of daytime SUHII correlates negatively across cities with the difference of vegetation cover and activity between urban and suburban areas. Our results emphasize the key role of vegetation feedbacks in attenuating SUHII of big cities during the day, in particular during the growing season, further highlighting that increasing urban vegetation cover could be one effective way to mitigate the urban heat island effect.

Dominant control of agriculture and irrigation on urban heat island in India.

Science.gov (United States)

Kumar, Rahul; Mishra, Vimal; Buzan, Jonathan; Kumar, Rohini; Shindell, Drew; Huber, Matthew

2017-10-25

As is true in many regions, India experiences surface Urban Heat Island (UHI) effect that is well understood, but the causes of the more recently discovered Urban Cool Island (UCI) effect remain poorly constrained. This raises questions about our fundamental understanding of the drivers of rural-urban environmental gradients and hinders development of effective strategies for mitigation and adaptation to projected heat stress increases in rapidly urbanizing India. Here we show that more than 60% of Indian urban areas are observed to experience a day-time UCI. We use satellite observations and the Community Land Model (CLM) to identify the impact of irrigation and prove for the first time that UCI is caused by lack of vegetation and moisture in non-urban areas relative to cities. In contrast, urban areas in extensively irrigated landscapes generally experience the expected positive UHI effect. At night, UHI warming intensifies, occurring across a majority (90%) of India's urban areas. The magnitude of rural-urban temperature contrasts is largely controlled by agriculture and moisture availability from irrigation, but further analysis of model results indicate an important role for atmospheric aerosols. Thus both land-use decisions and aerosols are important factors governing, modulating, and even reversing the expected urban-rural temperature gradients.

Cooling urban heat islands with sustainable landscapes

Science.gov (United States)

E. Gregory McPherson

1994-01-01

This paper is directed to the policy-makers who are responsible for urban design and its climatological consequences. It summarizes our current knowledge on the structure, energetics, and mitigation of the urban heat island. Special attention is given to physical features of the environment that can be easily manipulated, particularly vegetation. Prototypical designs...

Stabilization of sawtooty oscillation by island heating

International Nuclear Information System (INIS)

Park, W.; Monticello, D.A.; Chu, T.K.

1986-10-01

Using the compressible resistive MHD equations in a finite aspect ratio cylinder, it is found that the m = 1 mode (the sawtooth oscillation) can saturate when the pressure inside the magnetic island is higher than that of the original core plasma. The saturation condition is of the form Δβ/sub p/ ≥ 8 ε -1 /sub q = 1/ (1 - q 0 ) 2 . This saturation effect can be used to actively stabilize sawteeth by heating the island and/or by cooling the core plasma. This mechanism together with a stabilizing toroidal effect may also explain recent lower-hybrid-wave-driven tokamak experiments where the saturation of sawteeth has been observed

Characterization of Urban Heat and Exacerbation: Development of a Heat Island Index for California

Directory of Open Access Journals (Sweden)

Haider Taha

2017-08-01

Full Text Available To further evaluate the factors influencing public heat and air-quality health, a characterization of how urban areas affect the thermal environment, particularly in terms of the air temperature, is necessary. To assist public health agencies in ranking urban areas in terms of heat stress and developing mitigation plans or allocating various resources, this study characterized urban heat in California and quantified an urban heat island index (UHII at the census-tract level (~1 km2. Multi-scale atmospheric modeling was carried out and a practical UHII definition was developed. The UHII was diagnosed with different metrics and its spatial patterns were characterized for small, large, urban-climate archipelago, inland, and coastal areas. It was found that within each region, wide ranges of urban heat and UHII exist. At the lower end of the scale (in smaller urban areas, the UHII reaches up to 20 degree-hours per day (DH/day; °C.hr/day, whereas at the higher end (in larger areas, it reaches up to 125 DH/day or greater. The average largest temperature difference (urban heat island within each region ranges from 0.5–1.0 °C in smaller areas to up to 5 °C or more at the higher end, such as in urban-climate archipelagos. Furthermore, urban heat is exacerbated during warmer weather and that, in turn, can worsen the health impacts of heat events presently and in the future, for which it is expected that both the frequency and duration of heat waves will increase.

Increasing of Urban Radiation due to Climate Change and Reduction Strategy using Vegetation

Science.gov (United States)

Park, C.; Lee, D.; Heo, H. K.; Ahn, S.

2017-12-01

Urban Heat Island (UHI) which means urban air temperature is higher than suburban area is one of the most important environmental issues in Urban. High density of buildings and high ratio of impervious surfaces increases the radiation fluxes in urban canopy. Furthermore, climate change is expected to make UHI even more seriously in the future. Increased irradiation and air temperature cause high amount of short wave and long wave radiation, respectively. This increases net radiation negatively affects heat condition of pedestrian. UHI threatens citizen's health by increasing violence and heat related diseases. For this reason, understanding how much urban radiation will increase in the future, and exploring radiation reduction strategies is important for reducing UHI. In this research, we aim to reveal how the radiation flux in the urban canyon will change as the climate change and determine how much of urban vegetation will be needed to cover this degradation. The study area is a commercial district in Seoul where highly populated area. Due to the high density of buildings and lack of urban vegetation, this area has a poor thermal condition in summer. In this research, we simulate the radiation flux on the ground using multi-layer urban canopy model. Unlike conventionally used urban canopy model to simulate radiation transfer using vertically single layer, the multi-layer model we used here, enables to consider the vertical heterogeneous of buildings and urban vegetation. As a result, net radiation of urban ground will be increase 2.1 W/m² in the 2050s and 2.7 W/m² in the 2100s. And to prevent the increase of radiation, it is revealed that the urban vegetation should by increased by 10%. This research will be valuable in establishing greening planning as a strategy to reduce UHI effect.

Intensity of Urban Heat Islands in Tropical and Temperate Climates

Directory of Open Access Journals (Sweden)

Margarete Cristiane de Costa Trindade Amorim

2017-12-01

Full Text Available Nowadays, most of the Earth’s population lives in urban areas. The replacement of vegetation by buildings and the general soil sealing, associated with human activity, lead to a rise in cities temperature, resulting in the formation of urban heat islands. This article aims to evaluate the intensity and the hourly maintenance of the atmospheric heat islands in two climates: one tropical (Presidente Prudente, Brazil and one temperate (Rennes, France throughout 2016. For this, air temperature and hourly averages were measured and calculated using both a HOBO datalogger (U23-002—protected under the same RS3 brand and weather stations Davis Vantage PRO 2. The daily evolution of the heat islands presented characteristics that varied according to the hours and seasons of the year. For both Rennes and Presidente Prudente, the largest magnitudes occurred overnight, being more greatly expressed in the tropical environment and during the driest months (winter in the tropical city and summer in the temperate one. The variability of synoptic conditions from one month to another also leads to a great heterogeneity of UHI intensity throughout the year.

Impacts of urban growth and heat waves events on the urban heat island in Bucharest city

Science.gov (United States)

Zoran, Maria A.; Savastru, Roxana S.; Savastru, Dan M.; Dida, Adrian I.

2016-10-01

This study investigated the influences of urban growth and heat waves events on Urban Heat Island in relationship with several biophysical variables in Bucharest metropolitan area of Romania through satellite and in-situ monitoring data. Remote sensing data from Landsat TM/ETM+ and time series MODIS Terra/Aqua sensors have been used to assess urban land cover- temperature interactions over period between 2000 and 2016 years. Vegetation abundances and percent impervious surfaces were derived by means of linear spectral mixture model, and a method for effectively enhancing impervious surface has been developed to accurately examine the urban growth. The land surface temperature (Ts), a key parameter for urban thermal characteristics analysis, was also analyzed in relation with the Normalized Difference Vegetation Index (NDVI) at city level. Based on these parameters, the urban growth, urban heat island effect (UHI) and the relationships of Ts to other biophysical parameters (surface albedo, precipitations, wind intensity and direction) have been analyzed. Results show that in the metropolitan area ratio of impervious surface in Bucharest increased significantly during investigated period, the intensity of urban heat island and heat wave events being most significant. The correlation analyses revealed that, at the pixel-scale, Ts possessed a strong positive correlation with percent impervious surfaces and negative correlation with vegetation abundances at the regional scale, respectively. This analysis provided an integrated research scheme and the findings can be very useful for urban ecosystem modeling.

The Urban Heat Island Behavior of a Large Northern Latitude Metropolitan Area

Science.gov (United States)

Twine, T. E.; Snyder, P. K.; Hertel, W.; Mykleby, P.

2012-12-01

Urban heat islands (UHIs) occur when urban and suburban areas experience elevated temperatures relative to their rural surroundings because of differences in vegetation cover, buildings and other development, and infrastructure. Most cities in the United States are warming at twice the rate of the outlying rural areas and the planet as a whole. Temperatures in the urban center can be 2-5°C warmer during the daytime and as much as 10°C at night. Urban warming is responsible for excessive energy consumption, heat-related health effects, an increase in urban pollution, degradation of urban ecosystems, changes in the local meteorology, and an increase in thermal pollution into urban water bodies. One mitigation strategy involves manipulating the surface energy budget to either reduce the amount of solar radiation absorbed at the surface or offset absorbed energy through latent cooling. Options include using building materials with different properties of reflectivity and emissivity, increasing the reflectivity of parking lots, covering roofs with vegetation, and increasing the amount of vegetation overall through tree planting or increasing green space. The goal of the Islands in the Sun project is to understand the formation and behavior of urban heat islands and to mitigate their effects through sensible city engineering and design practices. As part of this project, we have been characterizing the UHI of the Twin Cities Metropolitan Area (TCMA), a 16,000 square kilometer urban and suburban region located in east central Minnesota that includes the two cities of Minneapolis and Saint Paul, and evaluating mitigation strategies for reducing urban warming. Annually, the TCMA has a modest 2-3°C UHI that is especially apparent in winter when the urban core can be up to 5-6°C warmer than the surrounding countryside. We present an analysis of regional temperature variations from a dense network of sensors located throughout the TCMA. We focus on the diurnal and seasonal

Avery Island heater tests: measured data for 1000 days of heating

International Nuclear Information System (INIS)

Van Sambeek, L.L.; Stickney, R.G.; DeJong, K.B.

1983-10-01

Three heater tests were conducted in the Avery Island salt mine. The measurements of temperature and displacement, and the calculation of stress in the vicinity of each heater are of primary importance in the understanding of the thermal and thermomechanical response of the salt to an emplaced heat source. This report presents the temperature, displacement, and calculated stress data gathered during the heating phase of the three heater tests. The data presented have application in the ongoing studies of the response of geologicic media to an emplaced heat source. Specifically, electric heaters, which simulate canisters of heat-generating nuclear waste, were placed in the floor of the Avery Island salt mine, and measurements were made of the response of the salt caused by the heating. The purpose of this report is to transmit the data to the scientific community; rigorous analysis and interpretation of the data are considered beyond the scope of this data report. 11 references, 46 figures

Mitigating the surface urban heat island: Mechanism study and sensitivity analysis

Science.gov (United States)

Meng, Chunlei

2017-08-01

In a surface urban heat island (SUHI), the urban land surface temperature (LST) is usually higher than the temperature of the surrounding rural areas due to human activities and surface characteristics. Because a SUHI has many adverse impacts on urban environment and human health, SUHI mitigation strategies are very important. This paper investigates the mechanism of a SUHI based on the basic physical laws that control the formation of a SUHI; five mitigation strategies are proposed, namely: sprinkling and watering; paving a pervious surface; reducing the anthropogenic heat (AH) release; using a "white roof"; increasing the fractional vegetation cover or leaf area index (LAI). To quantify the effect of these mitigation strategies, 26 sets of experiments are designed and implemented by running the integrated urban land model (IUM). The results of the sensitivity analysis indicate that sprinkling and watering is an effective measure for mitigating a SUHI for an entire day. Decreasing the AH release is also useful for both night- and daytime SUHI mitigation; however, the cooling extent is proportional to the diurnal cycle of AH. Increasing the albedo can reduce the LST in the daytime, especially when the solar radiation is significant; the cooling extent is approximately proportional to the diurnal cycle of the net radiation. Increasing the pervious surface percentage can mitigate the SUHI especially in the daytime. Increasing the fractional vegetation cover can mitigate the SUHI in the daytime but may aggravate the SUHI at night.

Comprehensive assessments of measures mitigating heat island phenomena in urban areas; Heat shinku wo riyoshita daikibo reibo system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Mizuno, T; Yamamoto, S; Yoshikado, H; Kondo, H; Kaneho, N; Saegusa, N; Inaba, A [National Institute for Resources and Environment, Tsukuba (Japan); Inoue, M [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

1997-02-01

This paper describes the assessment method of measures mitigating heat island phenomena in urban areas. The heat island phenomena were classified into meso-scale with 100 km-scale, block-scale with several km-scale, and building-scale with 100 m-scale. Urban thermal environment simulation model was developed in response to each scale. For the development, regional data using aircraft and artificial satellite observations, surface observation and thermal environment observation at Shinjuku new central city of Tokyo, and artificial waste heat actual survey data in the southern Kanto district were utilized. Results of the urban thermal environment simulation were introduced as an application of this model. Temperature distributions of the heat island in the Kanto district were simulated with considering urban conditions near Tokyo and without considering it. Daily changes of wall surfaces of high buildings and road surface were calculated. Increase in the air temperature in the back stream of building roofs with increased temperature was determined. 4 figs.

Contrasting responses of urban and rural surface energy budgets to heat waves explain synergies between urban heat islands and heat waves

International Nuclear Information System (INIS)

Li, Dan; Sun, Ting; Liu, Maofeng; Yang, Long; Wang, Linlin; Gao, Zhiqiu

2015-01-01

Heat waves (HWs) are projected to become more frequent and last longer over most land areas in the late 21st century, which raises serious public health concerns. Urban residents face higher health risks due to synergies between HWs and urban heat islands (UHIs) (i.e., UHIs are higher under HW conditions). However, the responses of urban and rural surface energy budgets to HWs are still largely unknown. This study analyzes observations from two flux towers in Beijing, China and reveals significant differences between the responses of urban and rural (cropland) ecosystems to HWs. It is found that UHIs increase significantly during HWs, especially during the nighttime, implying synergies between HWs and UHIs. Results indicate that the urban site receives more incoming shortwave radiation and longwave radiation due to HWs as compared to the rural site, resulting in a larger radiative energy input into the urban surface energy budget. Changes in turbulent heat fluxes also diverge strongly for the urban site and the rural site: latent heat fluxes increase more significantly at the rural site due to abundant available water, while sensible heat fluxes and possibly heat storage increase more at the urban site. These comparisons suggest that the contrasting responses of urban and rural surface energy budgets to HWs are responsible for the synergies between HWs and UHIs. As a result, urban mitigation and adaption strategies such as the use of green roofs and white roofs are needed in order to mitigate the impact of these synergies. (letter)

The correlation of urban heat island in tropical middle-class housing

Science.gov (United States)

Wazir, Zuber Angkasa

2017-11-01

A very limited number of green and sustainable construction studies have explored factors related to Urban Heat Island (UHI) in tropical middle-class housing. This paper aimed to investigate the correlation of Urban Heat Island in tropical middle-class housing in three urban housing for middle-class residents of Palembang, which were Taman Sari Kenten, TOP Jakabaring, and Talang Kelapa. Samples consisted of 125 Taman Sari Kenten housing, 27 Talang Kelapa housing, and 12 TOP Jakabaring housing. Independent variables were the resident density, socioeconomic status, house location, roof type, green area ratio, weather, time, air conditioner, pro-environment institution, and NEP scale. The Analytic method included correlation and regression. We identified that all housing had different UHI profiles where Taman Sari Kenten had the highest UHI (4.17 K), followed by Talang Kelapa (2.66 K) and TOP Jakabaring (0.66 K) against temperature in measuring station nearby, owned by BMKG (National Meteorological Station). UHI correlated with the resident density, roof type, green area ratio, weather, time, and air conditioner. The results should add to the design of ideal housing in the tropical climate for middle-class residents, focusing on its ability to mitigate Urban Heat Island.

Assessment of Urban Heat Islands in Small- and Mid-Sized Cities in Brazil

Directory of Open Access Journals (Sweden)

Renata dos Santos Cardoso

2017-02-01

Full Text Available Urban heat islands (UHIs in large cities and different climatic regions have been thoroughly studied; however, their effects are becoming a common concern in smaller cities as well. We assessed UHIs in three tropical cities, analyzing how synoptic conditions, urban morphology, and land cover affect the heat island magnitude. Data gathering involved mobile surveys across Paranavaí (Paraná, Rancharia (São Paulo, and Presidente Prudente (São Paulo, Brazil, during summer evenings (December 2013–January 2014. Temperature data collected over five days in each city point to heat islands with magnitudes up to 6 °C, under calm synoptic conditions, whereas summer average UHI magnitudes peak at 3.7 °C. In addition, UHI magnitudes were higher in areas with closely spaced buildings and few or no trees and building materials that are not appropriate for the region’s climate and thermal comfort.

Urban heat islands in the subsurface of German cities

Science.gov (United States)

Menberg, K.; Blum, P.; Zhu, K.; Bayer, P.

2012-04-01

In the subsurface of many cities there are widespread and persistent thermal anomalies (subsurface urban heat islands) that result in a warming of urban aquifers. The reasons for this heating are manifold. Possible heat sources are basements of buildings, leakage of sewage systems, buried district heating networks, re-injection of cooling water and solar irradiation on paved surfaces. In the current study, the reported groundwater temperatures in several German cities, such as Berlin, Munich, Cologne and Karlsruhe, are compared. Available data sets are supplemented by temperature measurements and depth profiles in observation wells. Trend analyses are conducted with time series of groundwater temperatures, and three-dimensional groundwater temperature maps are provided. In all investigated cities, pronounced positive temperature anomalies are present. The distribution of groundwater temperatures appears to be spatially and temporally highly variable. Apparently, the increased heat input into the urban subsurface is controlled by very local and site-specific parameters. In the long-run, the superposition of various heat sources results in an extensive temperature increase. In many cases, the maximum temperature elevation is found close to the city centre. Regional groundwater temperature differences between the city centre and the rural background are up to 5 °C, with local hot spots of even more pronounced anomalies. Particular heat sources, like cooling water injections or case-specific underground constructions, can cause local temperatures > 20°C in the subsurface. Examination of the long-term variations in isotherm maps shows that temperatures have increased by about 1°C in the city, as well as in the rural background areas over the last decades. This increase could be reproduced with trend analysis of temperature data gathered from several groundwater wells. Comparison between groundwater and air temperatures in Karlsruhe, for example, also indicates a

Vietnam; Poverty Reduction Strategy Paper

OpenAIRE

International Monetary Fund

2004-01-01

This paper assesses the Poverty Reduction Strategy Paper of Vietnam, known as the Comprehensive Poverty Reduction and Growth Strategy (CPRGS). It is an action program to achieve economic growth and poverty reduction objectives. This paper reviews the objectives and tasks of socio-economic development and poverty reduction. The government of Vietnam takes poverty reduction as a cutting-through objective in the process of country socio-economic development and declares its commitment to impleme...

Urban heat island research from 1991 to 2015: a bibliometric analysis

Science.gov (United States)

Huang, Qunfang; Lu, Yuqi

2018-02-01

A bibliometric analysis based on the Science Citation Index-Expanded (SCI-Expanded) database from the Web of Science was performed to review urban heat island (UHI) research from 1991 to 2015 and statistically assess its developments, trends, and directions. In total, 1822 papers published in 352 journals over the past 25 years were analyzed for scientific output; citations; subject categories; major journals; outstanding keywords; and leading countries, institutions, authors, and research collaborations. The number of UHI-related publications has continuously increased since 1991. Meteorology atmospheric sciences, environmental sciences, and construction building technology were the three most frequent subject categories. Building and Environment, International Journal of Climatology, and Theoretical and Applied Climatology were the three most popular publishing journals. The USA and China were the two leading countries in UHI research, contributing 49.56% of the total articles. Chinese Academy of Science, Arizona State University, and China Meteorological Administration published the most UHI articles. Weng QH and Santamouris M were the two most prolific authors. Author keywords were classified into four major groups: (1) research methods and indicators, e.g., remote sensing, field measurement, and models; (2) generation factors, e.g., impervious urban surfaces, urban geometry, waste heat, vegetation, and pollutants; (3) environmental effects, e.g., urban climate, heat wave, ecology, and pollution; and (4) mitigation and adaption strategies, e.g., roof technology cooling, reflective cooling, vegetation cooling, and urban geometry cooling. A comparative analysis of popular issues revealed that UHI determination (intensity, heat source, supporting techniques) remains the central topic, whereas UHI impacts and mitigation strategies are becoming the popular issues that will receive increasing scientific attention in the future. Modeling will continue to be the

Acquisition and Processing of High Resolution Hyperspectral Imageries for the 3d Mapping of Urban Heat Islands and Microparticles of Montreal

Science.gov (United States)

Mongeau, R.; Baudouin, Y.; Cavayas, F.

2017-10-01

Ville de Montreal wanted to develop a system to identify heat islands and microparticles at the urban scale and to study their formation. UQAM and UdeM universities have joined their expertise under the framework "Observatoire Spatial Urbain" to create a representative geospatial database of thermal and atmospheric parameters collected during the summer months. They innovated in the development of a methodology for processing high resolution hyperspectral images (1-2 m). In partnership with Ville de Montreal, they integrated 3D geospatial data (topography, transportation and meteorology) in the process. The 3D mapping of intraurban heat islands as well as air micro-particles makes it possible, initially, to identify the problematic situations for future civil protection interventions during extreme heat. Moreover, it will be used as a reference for the Ville de Montreal to establish a strategy for public domain tree planting and in the analysis of urban development projects.

Adaptation measures for climate change and the urban heat island in Japan's built environment

International Nuclear Information System (INIS)

Shimoda, Y.

2003-01-01

Climate change scenarios are discussed for Japan with clear implications drawn for the built environment in terms of increased temperatures of 4-5 o C, rising sea levels and subterranean water tables. Research on the impacts and adaptation measures for global warming in Japan is reviewed. One of the most significant impacts of climate change in Japan will exacerbate the existing heat island phenomenon in cities by absorbing increased solar radiation. This will lead to further increases in temperatures in an urban microclimate with negative implications for energy and water consumption, human health and discomfort, and local ecosystems. The current urban heat island phenomenon and its impacts are described. The relationships between climate change and urban heat island impacts are discussed. Potential adaptation measures to those impacts are also discussed and proposed. (author)

Existing climate data sources and Their Use in Heat IslandResearch

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hashem; Pon, Brian; Smith, Craig Kenton; Stamper-Kurn, Dan Moses

1998-10-01

Existing climate data sources can be used in two general types of analysis for the detection of urban heat islands. Historical analyses use long-term data records-preferentially from several locations in and around an urban area-to trace the gradual influence of urban development on its climate. Primary sources of such data include the cooperative network, first-order National Weather Service stations, and military weather stations. Analyses of short-term data use information from a dense urban weather station network to discern the location, extent, and magnitude of urban heat islands. Such analyses may use the aforementioned national networks or regional networks such as agricultural, air quality monitoring, or utility networks. We demonstrate the use of existing data sources with a historical analysis of temperature trends in Los Angeles, California, and an analysis of short-term data of the urban temperature profile for Phoenix, Arizona. The Los Angeles climate was examined with eleven long-term data records from the cooperative network. Statistically significant trends of rising temperature were detected at Los Angeles Civic Center and other stations over some parts of the year, although timing of the increase varied from station to station. Observed increases in temperatures maybe due to long-term climate changes, microclimate influences, or local-scale heat islands. The analysis of short-term data was made for Phoenix using the PRISMS station network. Mean diurnal temperature profiles for a month were examined and compared with those for adjacent rural areas. Data fi-om stations in the center of Phoenix showed clear and significant nighttime and daytime temperature differences of 1- 2K (3 - 4"F). These temperature increases maybe attributable to a local-scale heat island.

Strategy Development of Community Base Tourism in Tidung Island, Jakarta

Directory of Open Access Journals (Sweden)

Dhian Tyas Untari

2018-05-01

Full Text Available The aim of thus study is to establish a community-based tourism development strategy in Tidung Island. Researcher use Strategy Management matrix, In this research, tourist entrepreneurs and tourist as an observation unit and is determined as an analysis unit of the company that is the decision makers are very influential in the company itself, including related Human Resources, Finance, Production, and Marketing. Eigen Factor score is use ase the weighting input data from the results of questionnaires. From the questionnaire, a score is obtained from the average given by the respondents at each key success factors, where in the input process the researcher used IFAS / IFAS Matrix, and in the process of strategy formulation, the researcher used the recommendation from the Grand Matrix Strategy output. The results of the output recommendations, which will then be implemented in the development of community-based tourism on the island of Tidung. Based on the Grand Matrix Strategy chart seen that the outline of Tidung Island tourism into the weak category, where the quadrant Challenges and Weaknesses is much greater than the strength and opportunities. Thus the strategy that can be done is with; improve tourism governance by maximizing the function of tourism development programs of DKI Jakarta Province, encouraging the Provincial Government of DKI Jakarta to allocate funds and attention to alternative tourism such as marine tourism located in Kepulauan Seribu, maximizing Community Service Activities of Higher Education as a medium of knowladge community transfer Tidung Island, improving the mode of transportation and increasing the frequency of ship felling Jakarta - Pulau Tidung.

Monitoring the effects of land use/landcover changes on urban heat island

Science.gov (United States)

Gee, Ong K.; Sarker, Md Latifur Rahman

2013-10-01

Urban heat island effects are well known nowadays and observed in cities throughout the World. The main reason behind the effects of urban heat island (UHI) is the transformation of land use/ land cover, and this transformation is associated with UHI through different actions: i) removal of vegetated areas, ii) land reclamation from sea/river, iii) construction of new building as well as other concrete structures, and iv) industrial and domestic activity. In rapidly developing cities, urban heat island effects increases very hastily with the transformation of vegetated/ other types of areas into urban surface because of the increasing population as well as for economical activities. In this research the effect of land use/ land cover on urban heat island was investigated in two growing cities in Asia i.e. Singapore and Johor Bahru, (Malaysia) using 10 years data (from 1997 to 2010) from Landsat TM/ETM+. Multispectral visible band along with indices such as Normalized Difference Vegetation Index (NDVI), Normalized Difference Build Index (NDBI), and Normalized Difference Bareness Index (NDBaI) were used for the classification of major land use/land cover types using Maximum Likelihood Classifiers. On the other hand, land surface temperature (LST) was estimated from thermal image using Land Surface Temperature algorithm. Emissivity correction was applied to the LST map using the emissivity values from the major land use/ land cover types, and validation of the UHI map was carried out using in situ data. Results of this research indicate that there is a strong relationship between the land use/land cover changes and UHI. Over this 10 years period, significant percentage of non-urban surface was decreased but urban heat surface was increased because of the rapid urbanization. With the increase of UHI effect it is expected that local urban climate has been modified and some heat related health problem has been exposed, so appropriate measure should be taken in order to

Diffusive heat transport across magnetic islands and stochastic layers in tokamaks

International Nuclear Information System (INIS)

Hoelzl, Matthias

2010-01-01

Heat transport in tokamak plasmas with magnetic islands and ergodic field lines was simulated at realistic plasma parameters in realistic tokamak geometries. This requires the treatment of anisotropic heat diffusion, which is more efficient along magnetic field lines by up to ten orders of magnitude than perpendicular to them. Comparisons with analytical predictions and experimental measurements allow to determine the stability properties of neoclassical tearing modes as well as the experimental heat diffusion anisotropy.

Micrometeorological simulations to predict the impacts of heat mitigation strategies on pedestrian thermal comfort in a Los Angeles neighborhood

Science.gov (United States)

Taleghani, Mohammad; Sailor, David; Ban-Weiss, George A.

2016-02-01

The urban heat island impacts the thermal comfort of pedestrians in cities. In this paper, the effects of four heat mitigation strategies on micrometeorology and the thermal comfort of pedestrians were simulated for a neighborhood in eastern Los Angeles County. The strategies investigated include solar reflective ‘cool roofs’, vegetative ‘green roofs’, solar reflective ‘cool pavements’, and increased street-level trees. A series of micrometeorological simulations for an extreme heat day were carried out assuming widespread adoption of each mitigation strategy. Comparing each simulation to the control simulation assuming current land cover for the neighborhood showed that additional street-trees and cool pavements reduced 1.5 m air temperature, while cool and green roofs mostly provided cooling at heights above pedestrian level. However, cool pavements increased reflected sunlight from the ground to pedestrians at a set of unshaded receptor locations. This reflected radiation intensified the mean radiant temperature and consequently increased physiological equivalent temperature (PET) by 2.2 °C during the day, reducing the thermal comfort of pedestrians. At another set of receptor locations that were on average 5 m from roadways and underneath preexisting tree cover, cool pavements caused significant reductions in surface air temperatures and small changes in mean radiant temperature during the day, leading to decreases in PET of 1.1 °C, and consequent improvements in thermal comfort. For improving thermal comfort of pedestrians during the afternoon in unshaded locations, adding street trees was found to be the most effective strategy. However, afternoon thermal comfort improvements in already shaded locations adjacent to streets were most significant for cool pavements. Green and cool roofs showed the lowest impact on the thermal comfort of pedestrians since they modify the energy balance at roof level, above the height of pedestrians.

Micrometeorological simulations to predict the impacts of heat mitigation strategies on pedestrian thermal comfort in a Los Angeles neighborhood

International Nuclear Information System (INIS)

Taleghani, Mohammad; Ban-Weiss, George A; Sailor, David

2016-01-01

The urban heat island impacts the thermal comfort of pedestrians in cities. In this paper, the effects of four heat mitigation strategies on micrometeorology and the thermal comfort of pedestrians were simulated for a neighborhood in eastern Los Angeles County. The strategies investigated include solar reflective ‘cool roofs’, vegetative ‘green roofs’, solar reflective ‘cool pavements’, and increased street-level trees. A series of micrometeorological simulations for an extreme heat day were carried out assuming widespread adoption of each mitigation strategy. Comparing each simulation to the control simulation assuming current land cover for the neighborhood showed that additional street-trees and cool pavements reduced 1.5 m air temperature, while cool and green roofs mostly provided cooling at heights above pedestrian level. However, cool pavements increased reflected sunlight from the ground to pedestrians at a set of unshaded receptor locations. This reflected radiation intensified the mean radiant temperature and consequently increased physiological equivalent temperature (PET) by 2.2 °C during the day, reducing the thermal comfort of pedestrians. At another set of receptor locations that were on average 5 m from roadways and underneath preexisting tree cover, cool pavements caused significant reductions in surface air temperatures and small changes in mean radiant temperature during the day, leading to decreases in PET of 1.1 °C, and consequent improvements in thermal comfort. For improving thermal comfort of pedestrians during the afternoon in unshaded locations, adding street trees was found to be the most effective strategy. However, afternoon thermal comfort improvements in already shaded locations adjacent to streets were most significant for cool pavements. Green and cool roofs showed the lowest impact on the thermal comfort of pedestrians since they modify the energy balance at roof level, above the height of pedestrians. (letter)

Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling

Energy Technology Data Exchange (ETDEWEB)

Lustbader, Jason Aaron; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory J.; Yeakel, Skip; Adelman, Steven; Luo, Zhiming; Zehme, John

2016-04-05

Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

A global analysis of the urban heat island effect based on multisensor satellite data

Science.gov (United States)

Xiao, J.; Frolking, S. E.; Milliman, T. E.; Schneider, A.; Friedl, M. A.

2017-12-01

Human population is rapidly urbanizing. In much of the world, cities are prone to hotter weather than surrounding rural areas - so-called `urban heat islands' - and this effect can have mortal consequences during heat waves. During the daytime, when the surface energy balance is driven by incoming solar radiation, the magnitude of urban warming is strongly influenced by surface albedo and the capacity to evaporate water (i.e., there is a strong relationship between vegetated land fraction and the ratio of sensible to latent heat loss or Bowen ratio). At nighttime, urban cooling is often inhibited by the thermal inertia of the built environment and anthropogenic heat exhaust from building and transportation energy use. We evaluated a suite of global remote sensing data sets representing a range of urban characteristics against MODIS-derived land-surface temperature differences between urban and surrounding rural areas. We included two new urban datasets in this analysis - MODIS-derived change in global urban extent and global urban microwave backscatter - along with several MODIS standard products and DMSP/OLS nighttime lights time series data. The global analysis spanned a range of urban characteristics that likely influence the magnitude of daytime and/or nighttime urban heat islands - urban size, population density, building density, state of development, impervious fraction, eco-climatic setting. Specifically, we developed new satellite datasets and synthesizing these with existing satellite data into a global database of urban land surface parameters, used two MODIS land surface temperature products to generate time series of daytime and nighttime urban heat island effects for 30 large cities across the globe, and empirically analyzed these data to determine specifically which remote sensing-based characterizations of global urban areas have explanatory power with regard to both daytime and nighttime urban heat islands.

Assessing Heat Health Risk for Sustainability in Beijing’s Urban Heat Island

Directory of Open Access Journals (Sweden)

Weihua Dong

2014-10-01

Full Text Available This research is motivated by the increasing threat of urban heat waves that are likely worsened by pervasive global warming and urbanization. Different regions of the city including urban, borderland and rural area will experience different levels of heat health risk. In this paper, we propose an improved approach to quantitatively assess Beijing’s heat health risk based on three factors from hazard, vulnerability and especially environment which is considered as an independent factor because different land use/cover types have different influence on ambient air temperatures under the Urban Heat Island effect. The results show that the heat health risk of Beijing demonstrates a spatial-temporal pattern with higher risk in the urban area, lower risk in the borderland between urban and rural area, and lowest risk in the rural area, and the total risk fluctuated dramatically during 2008–2011. To be more specific, the heat health risk was clearly higher in 2009 and 2010 than in 2008 and 2011. Further analysis with the urban area at sub-district level signifies that the impervious surface (urban area such as buildings, roads, et al. ratio is of high correlation with the heat health risk. The validation results show that the proposed method improved the accuracy of heat health risk assessment. We recommend that policy makers should develop efficient urban planning to accomplish Beijing’s sustainable development.

Comparative and Combinative Study of Urban Heat island in Wuhan City with Remote Sensing and CFD Simulation

Directory of Open Access Journals (Sweden)

Zhuang Yu

2008-10-01

Full Text Available Urban heat islands are one of the most critical urban environment heat problems. Landsat ETM+ satellite data were used to investigate the land surface temperature and underlying surface indices such as NDVI and NDBI. A comparative study of the urban heat environment at different scales, times and locations was done to verify the heat island characteristics. Since remote sensing technology has limitations for dynamic flow analysis in the study of urban spaces, a CFD simulation was used to validate the improvement of the heat environment in a city by means of wind. CFD technology has its own shortcomings in parameter setting and verification, while RS technology is helpful to remedy this. The city of Wuhan and its climatological condition of being hot in summer and cold in winter were chosen to verify the comparative and combinative application of RS with CFD in studying the urban heat island.

An estimator-based distributed voltage-predictive control strategy for ac islanded microgrids

DEFF Research Database (Denmark)

Wang, Yanbo; Chen, Zhe; Wang, Xiongfei

2015-01-01

This paper presents an estimator-based voltage predictive control strategy for AC islanded microgrids, which is able to perform voltage control without any communication facilities. The proposed control strategy is composed of a network voltage estimator and a voltage predictive controller for each...... and has a good capability to reject uncertain perturbations of islanded microgrids....

Effectiveness of Different Urban Heat Island Mitigation Methods and Their Regional Impacts

Science.gov (United States)

Zhang, N.

2017-12-01

Cool roofs and green roofs are two popular methods to mitigate urban heat island and improve urban climate. The effectiveness of different urban heat island mitigation strategies in the summer of 2013 in the Yangtze River Delta, China is investigated using the WRF (Weather Research and Forecasting) model coupled with a physically based urban canopy model. The modifications to the roof surface changed the urban surface radiation balance and then modified the local surface energy budget. Both cool roofs and green roofs led to lower surface skin temperature and near-surface air temperature. Increasing the roof albedo to 0.5 caused a similar effectiveness as covering 25% of urban roofs with vegetation; increasing roof albedo to 0.7 caused a similar near-surface air temperature decrease as 75% green roof coverage. The near-surface relative humidity increased in both cool roof and green roof experiments because of the combination of the impacts of increases in specific humidity and decreases in air temperature. The regional impacts of cool roofs and green roofs were evaluated using the regional effect index. The regional effect could be found in both near-surface air temperature and surface specific/relative humidity when the percentage of roofs covered with high albedo materials or green roofs reached a higher fraction (greater than 50%). The changes in the vertical profiles of temperature cause a more stable atmospheric boundary layer over the urban area; at the same time, the crossover phenomena occurred above the boundary layer due to the decrease in vertical wind speed.

Analysis of the ability of water resources to reduce the urban heat island in the Tokyo megalopolis

International Nuclear Information System (INIS)

Nakayama, Tadanobu; Hashimoto, Shizuka

2011-01-01

Simulation procedure integrated with multi-scale in horizontally regional-urban-point levels and in vertically atmosphere-surface-unsaturated-saturated layers, was newly developed in order to predict the effect of urban geometry and anthropogenic exhaustion on the hydrothermal changes in the atmospheric/land and the interfacial areas of the Japanese megalopolis. The simulated results suggested that the latent heat flux in new water-holding pavement (consisting of porous asphalt and water-holding filler made of steel by-products based on silica compound) has a strong impact on hydrologic cycle and cooling temperature in comparison with the observed heat budget. We evaluated the relationship between the effect of groundwater use as a heat sink to tackle the heat island and the effect of infiltration on the water cycle in the urban area. The result indicates that effective management of water resources would be powerful for ameliorating the heat island and recovering sound hydrologic cycle there. - Highlights: → Simulation procedure with multi-scale was newly developed. → Latent heat flux in water-holding pavement had strong impact on hydrothermal changes. → Model predicted effect of urban geometry and anthropogenic exhaustion. → Effective management of water resources is powerful for ameliorating heat island. - This study indicates that effective management of water resources would be powerful for ameliorating the heat island and recovering sound hydrologic cycle in urban area.

Analysis of the ability of water resources to reduce the urban heat island in the Tokyo megalopolis

Energy Technology Data Exchange (ETDEWEB)

Nakayama, Tadanobu, E-mail: nakat@nies.go.jp [Asian Environment Research Group, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Process Hydrology Section, Centre for Ecology and Hydrology (CEH), Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Hashimoto, Shizuka [Faculty of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)

2011-08-15

Simulation procedure integrated with multi-scale in horizontally regional-urban-point levels and in vertically atmosphere-surface-unsaturated-saturated layers, was newly developed in order to predict the effect of urban geometry and anthropogenic exhaustion on the hydrothermal changes in the atmospheric/land and the interfacial areas of the Japanese megalopolis. The simulated results suggested that the latent heat flux in new water-holding pavement (consisting of porous asphalt and water-holding filler made of steel by-products based on silica compound) has a strong impact on hydrologic cycle and cooling temperature in comparison with the observed heat budget. We evaluated the relationship between the effect of groundwater use as a heat sink to tackle the heat island and the effect of infiltration on the water cycle in the urban area. The result indicates that effective management of water resources would be powerful for ameliorating the heat island and recovering sound hydrologic cycle there. - Highlights: > Simulation procedure with multi-scale was newly developed. > Latent heat flux in water-holding pavement had strong impact on hydrothermal changes. > Model predicted effect of urban geometry and anthropogenic exhaustion. > Effective management of water resources is powerful for ameliorating heat island. - This study indicates that effective management of water resources would be powerful for ameliorating the heat island and recovering sound hydrologic cycle in urban area.

Logistics Reduction: Heat Melt Compactor

Data.gov (United States)

National Aeronautics and Space Administration — The Advanced Exploration Systems (AES) Logistics Reduction (LR) project Heat Melt Compactor (HMC) technology is a waste management technology. Currently, there are...

A Communication-Supported Comprehensive Protection Strategy for Converter-Interfaced Islanded Microgrids

Directory of Open Access Journals (Sweden)

Dehua Zheng

2018-04-01

Full Text Available The deployment of distributed generators (DGs gives rise to several challenges for a microgrid or conventional distribution feeder, regarding control and protection issues. The major ones are: bi-directional flow of power, changes in fault current magnitude, and continuous changes in operational configuration due to both the plug-and-play of DGs and loads, and the intermittency of the renewable DGs. This issue is exacerbated when the microgrid contains several converter-interfaced DGs and operates in the islanded mode of operation. Hence, conventional protection strategies and relaying techniques will no longer be sufficient to protect islanded microgrids against network faults and disturbance conditions. This paper proposes a fast and reliable communication-supported protection strategy for ensuring the safe operation of converter-interfaced islanded microgrids. The strategy is implementable using commercially accessible microprocessor based digital relays, and is applicable for the protection of low voltage islanded microgrids. It provides backup protection to handle communication failures and malfunctions of protective devices. The paper also presents the detailed structural layout of the digital relay, which executes the proposed protection strategy. A number of improvements are proposed to find an alternative method for conventional overcurrent relays to reliably detect small-magnitude fault currents and high impedance faults, commonly encountered in converter-interfaced islanded microgrids. A simple and economical bus protection method is also proposed. Several simulations are conducted on a comprehensive model of a realistic operational industrial microgrid (Goldwind Smart Microgrid System using PSCAD/EMTDC software environment—for different case studies and fault scenarios—to verify the effectiveness of the present strategy and its digital relay.

Climate Control Load Reduction Strategies for Electric Drive Vehicles in Warm Weather

Energy Technology Data Exchange (ETDEWEB)

Jeffers, M. A.; Chaney, L.; Rugh, J. P.

2015-04-30

Passenger compartment climate control is one of the largest auxiliary loads on a vehicle. Like conventional vehicles, electric vehicles (EVs) require climate control to maintain occupant comfort and safety, but cabin heating and air conditioning have a negative impact on driving range for all electric vehicles. Range reduction caused by climate control and other factors is a barrier to widespread adoption of EVs. Reducing the thermal loads on the climate control system will extend driving range, thereby reducing consumer range anxiety and increasing the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have investigated strategies for vehicle climate control load reduction, with special attention toward EVs. Outdoor vehicle thermal testing was conducted on two 2012 Ford Focus Electric vehicles to evaluate thermal management strategies for warm weather, including solar load reduction and cabin pre-ventilation. An advanced thermal test manikin was used to assess a zonal approach to climate control. In addition, vehicle thermal analysis was used to support testing by exploring thermal load reduction strategies, evaluating occupant thermal comfort, and calculating EV range impacts. Through stationary cooling tests and vehicle simulations, a zonal cooling configuration demonstrated range improvement of 6%-15%, depending on the drive cycle. A combined cooling configuration that incorporated thermal load reduction and zonal cooling strategies showed up to 33% improvement in EV range.

Subsurface urban heat islands in German cities.

Science.gov (United States)

Menberg, Kathrin; Bayer, Peter; Zosseder, Kai; Rumohr, Sven; Blum, Philipp

2013-01-01

Little is known about the intensity and extension of subsurface urban heat islands (UHI), and the individual role of the driving factors has not been revealed either. In this study, we compare groundwater temperatures in shallow aquifers beneath six German cities of different size (Berlin, Munich, Cologne, Frankfurt, Karlsruhe and Darmstadt). It is revealed that hotspots of up to +20K often exist, which stem from very local heat sources, such as insufficiently insulated power plants, landfills or open geothermal systems. When visualizing the regional conditions in isotherm maps, mostly a concentric picture is found with the highest temperatures in the city centers. This reflects the long-term accumulation of thermal energy over several centuries and the interplay of various factors, particularly in heat loss from basements, elevated ground surface temperatures (GST) and subsurface infrastructure. As a primary indicator to quantify and compare large-scale UHI intensity the 10-90%-quantile range UHII(10-90) of the temperature distribution is introduced. The latter reveals, in comparison to annual atmospheric UHI intensities, an even more pronounced heating of the shallow subsurface. Copyright © 2012 Elsevier B.V. All rights reserved.

Analysis of the effect of local heat island in Seoul using LANDSAT image

Science.gov (United States)

Lee, K. I.; Ryu, J.; Jeon, S. W.

2017-12-01

The increase in the rate of industrialization due to urbanization has caused the Urban Heat Island phenomenon which means that the temperature of the city is higher than the surrounding area, and its intensity is increasing with climate change. Among the cities where heat island phenomenon occur, Seoul city has different degree of urbanization, green area ratio, energy consumption, and population density by each district unit. As a result, the strength of heat island phenomenon is also different. The average maximum temperature in each region may differ by more than 3 °, which is bigger than the suburbs in Seoul and it means that analysis of UHI effect by regional unit is needed. Therefore, this study is to extract the UHI Intensity of the regional unit of the Seoul Metropolitan City using the satellite image, analyzed the difference of intensity according to the regional unit. And do linear regression analysis with variables included in three categories(regional meteorological conditions, anthropogenic heat generation, land use factors). As a result, The UHI Intensity value of the Gu unit is significantly different from the UHI Intensity distribution of the Dong unit. The variable having the greatest positive correlation with UHI Intensity was NDBI(Normalized Difference Built-up Index) which shows the distribution of urban area, and Urban area ratio also has high correlation. There was a negative correlation between mean wind speed but there was no significant correlation between population density and power consumption. The result of this study is to identify the regional difference of UHI Intensity and to identify the factors inducing heat island phenomenon. so It is expected that it will provide direction in urban thermal environment design and policy development in the future.

Caribbean small-island tourism styles and sustainable strategies

Science.gov (United States)

de Albuquerque, Klaus; McElroy, Jerome L.

1992-09-01

This article focuses on developing a sustainable tourism in small Caribbean islands, defined here as those that have populations of fewer than 500,000. Such islands share a very fragile ecology and a high dependence on tourism. They differ in their degree of tourist penetration and visitor density and the related degree of environmental degradation. To explain the link between tourism intensity and ecological vulnerability, the so-called “destination life-cycle model” is presented. This suggests that islands pass through three primary stages of tourist development low-density exploration, rapid growth and consolidation, and high-density maturation involving the substitution of man-made for natural attractions. A broad empirical test of the model is performed through a quantitative examination of the tourism characteristics and visitor densities of a cross section of 23 small Caribbean islands. The three basic stages or tourism styles are identified: low-impact emerging areas, high-density mass-market mature destinations, and rapidly growing intermediate islands in between. Some broad strategies consistent with the systems framework for a sustainable tourism with moderate densitites are briefly explored.

Towards a Proactive Risk Mitigation Strategy at La Fossa Volcano, Vulcano Island

Science.gov (United States)

Biass, S.; Gregg, C. E.; Frischknecht, C.; Falcone, J. L.; Lestuzzi, P.; di Traglia, F.; Rosi, M.; Bonadonna, C.

2014-12-01

A comprehensive risk assessment framework was built to develop proactive risk reduction measures for Vulcano Island, Italy. This framework includes identification of eruption scenarios; probabilistic hazard assessment, quantification of hazard impacts on the built environment, accessibility assessment on the island and risk perception study. Vulcano, a 21 km2 island with two primary communities host to 900 permanent residents and up to 10,000 visitors during summer, shows a strong dependency on the mainland for basic needs (water, energy) and relies on a ~2 month tourism season for its economy. The recent stratigraphy reveals a dominance of vulcanian and subplinian eruptions, producing a range of hazards acting at different time scales. We developed new methods to probabilistically quantify the hazard related to ballistics, lahars and tephra for all eruption styles. We also elaborated field- and GIS- based methods to assess the physical vulnerability of the built environment and created dynamic models of accessibility. Results outline the difference of hazard between short and long-lasting eruptions. A subplinian eruption has a 50% probability of impacting ~30% of the buildings within days after the eruption, but the year-long damage resulting from a long-lasting vulcanian eruption is similar if tephra is not removed from rooftops. Similarly, a subplinian eruption results in a volume of 7x105 m3 of material potentially remobilized into lahars soon after the eruption. Similar volumes are expected for a vulcanian activity over years, increasing the hazard of small lahars. Preferential lahar paths affect critical infrastructures lacking redundancy, such as the road network, communications systems, the island's only gas station, and access to the island's two evacuation ports. Such results from hazard, physical and systemic vulnerability help establish proactive volcanic risk mitigation strategies and may be applicable in other island settings.

Interactions between urban heat islands and heat waves

Science.gov (United States)

Zhao, Lei; Oppenheimer, Michael; Zhu, Qing; Baldwin, Jane W.; Ebi, Kristie L.; Bou-Zeid, Elie; Guan, Kaiyu; Liu, Xu

2018-03-01

Heat waves (HWs) are among the most damaging climate extremes to human society. Climate models consistently project that HW frequency, severity, and duration will increase markedly over this century. For urban residents, the urban heat island (UHI) effect further exacerbates the heat stress resulting from HWs. Here we use a climate model to investigate the interactions between the UHI and HWs in 50 cities in the United States under current climate and future warming scenarios. We examine UHI2m (defined as urban-rural difference in 2m-height air temperature) and UHIs (defined as urban-rural difference in radiative surface temperature). Our results show significant sensitivity of the interaction between UHI and HWs to local background climate and warming scenarios. Sensitivity also differs between daytime and nighttime. During daytime, cities in the temperate climate region show significant synergistic effects between UHI and HWs in current climate, with an average of 0.4 K higher UHI2m or 2.8 K higher UHIs during HWs than during normal days. These synergistic effects, however, diminish in future warmer climates. In contrast, the daytime synergistic effects for cities in dry regions are insignificant in the current climate, but emerge in future climates. At night, the synergistic effects are similar across climate regions in the current climate, and are stronger in future climate scenarios. We use a biophysical factorization method to disentangle the mechanisms behind the interactions between UHI and HWs that explain the spatial-temporal patterns of the interactions. Results show that the difference in the increase of urban versus rural evaporation and enhanced anthropogenic heat emissions (air conditioning energy use) during HWs are key contributors to the synergistic effects during daytime. The contrast in water availability between urban and rural land plays an important role in determining the contribution of evaporation. At night, the enhanced release of stored

Energy Transition Initiative, Island Energy Snapshot - Bahamas (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2015-02-01

This profile provides a snapshot of the electricity generation or reduction technologies, including solar hot water heating, available to the Commonwealth of the Bahamas - a country consisting of more than 700 islands, cays, and islets - of which only 30 are actually inhabited. Heating and transportation fuels are not addressed.

Integration of coal gasification and waste heat recovery from high temperature steel slags: an emerging strategy to emission reduction

Science.gov (United States)

Sun, Yongqi; Sridhar, Seetharaman; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2015-01-01

With the continuous urbanization and industrialization in the world, energy saving and greenhouse gas (GHG) emission reduction have been serious issues to be addressed, for which heat recovery from traditional energy-intensive industries makes up a significant strategy. Here we report a novel approach to extract the waste heat and iron from high temperature steel slags (1450–1650 oC) produced in the steel industry, i.e., integration of coal gasification and steel slag treatment. Both the thermodynamics and kinetics of the pertinent reactions were identified. It was clarified that the kinetic mechanism for gasification varied from A2 model to A4 model (Avrami-Erofeev) in the presence of slags. Most importantly, the steel slags acted not only as good heat carriers but also as effective catalysts where the apparent activation energy for char gasification got remarkably reduced from 95.7 kJ/mol to 12.1 kJ/mol (A2 model). Furthermore, the FeO in the slags was found to be oxidized into Fe3O4, with an extra energy release, which offered a potential for magnetic separation. Moreover, based on the present research results, an emerging concept, composed of multiple industrial sectors, was proposed, which could serve as an important route to deal with the severe environmental problems in modern society. PMID:26558350

Observation of the bootstrap current reduction at magnetic island in a neoclassical tearing mode plasma

International Nuclear Information System (INIS)

Oikawa, T.; Suzuki, T.; Isayama, A.; Hayashi, N.; Fujita, T.; Naito, O.; Tuda, T.; Kurita, G.

2005-01-01

Evolution of the current density profile associated with magnetic island formation in a neoclassical tearing mode plasma is measured for the first time in JT-60U by using a motional Stark effect diagnostic. As the island grows, the current density profile turns flat at the radial region of the island and a hollow structure appears at the rational surface. As the island shrinks the deformed region becomes narrower and finally diminishes after the disappearance of the island. In a quiescent plasma without magnetohydrodynamic instabilities, on the other hand, no deformation is observed. The observed deformation in the current density profile associated with the tearing mode is reproduced in a time dependent transport simulation assuming the reduction of the bootstrap current in the radial region of the island. Comparison of the measurement with a calculated steady-state solution also shows that the reduction and recovery of the bootstrap current at the island explains the temporal behaviours of the current density and safety factor profiles. From the experimental observation and simulations, we reach the conclusion that the bootstrap current decreases within the island O-point

Energy Transition Initiative, Island Energy Snapshot - Turks & Caicos (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2015-02-01

This profile presents a snapshot of the electricity generation and reduction technologies, including solar hot water heating, available to Turks and Caicos - a British overseas territory consisting of two groups of islands located southeast of the Bahamas. Heating and transportation fuels are not addressed.

Modelling reduction of urban heat load in Vienna by modifying surface properties of roofs

Science.gov (United States)

Žuvela-Aloise, Maja; Andre, Konrad; Schwaiger, Hannes; Bird, David Neil; Gallaun, Heinz

2018-02-01

The study examines the potential of urban roofs to reduce the urban heat island (UHI) effect by changing their reflectivity and implementing vegetation (green roofs) using the example of the City of Vienna. The urban modelling simulations are performed based on high-resolution orography and land use data, climatological observations, surface albedo values from satellite imagery and registry of the green roof potential in Vienna. The modelling results show that a moderate increase in reflectivity of roofs (up to 0.45) reduces the mean summer temperatures in the densely built-up environment by approximately 0.25 °C. Applying high reflectivity materials (roof albedo up to 0.7) leads to average cooling in densely built-up area of approximately 0.5 °C. The green roofs yield a heat load reduction in similar order of magnitude as the high reflectivity materials. However, only 45 % of roof area in Vienna is suitable for greening and the green roof potential mostly applies to industrial areas in city outskirts and is therefore not sufficient for substantial reduction of the UHI effect, particularly in the city centre which has the highest heat load. The strongest cooling effect can be achieved by combining the green roofs with high reflectivity materials. In this case, using 50 or 100 % of the green roof potential and applying high reflectivity materials on the remaining surfaces have a similar cooling effect.

a Temporal and Spatial Analysis of Urban Heat Island in Basin City Utilizing Remote Sensing Techniques

Science.gov (United States)

Chang, Hsiao-Tung

2016-06-01

Urban Heat Island (UHI) has been becoming a key factor in deteriorating the urban ecological environment. Spatial-temporal analysis on its prototype of basin city's UHI and quantitatively evaluating effect from rapid urbanization will provide theoretical foundation for relieving UHI effect. Based on Landsat 8, ETM+ and TM images of Taipei basin areas from 1900 to 2015, this article has retrieved the land surface temperature (LST) at summer solstice of each year, and then analysed spatial-temporal pattern and evolution characters of UHI in Taipei basin in this decade. The results showed that the expansion built district, UHI area constantly expanded from centre city to the suburb areas. The prototype of UHI in Taipei basin that showed in addition to higher temperatures in the centre city also were relatively high temperatures gathered boundaries surrounded by foot of mountains side. It calls "sinking heat island". From 1900 to 2000, the higher UHI areas were different land use type change had obvious difference by public infrastructure works. And then, in next 15 years till 2015, building density of urban area has been increasing gradually. It has the trend that UHI flooding raises follow urban land use density. Hot spot of UHI in Taipei basin also has the same characteristics. The results suggest that anthropogenic heat release probably plays a significant role in the UHI effect, and must be considered in urban planning adaptation strategies.

Stabilization of a magnetic island by localized heating in a tokamak with stiff temperature profile

Science.gov (United States)

Maget, Patrick; Widmer, Fabien; Février, Olivier; Garbet, Xavier; Lütjens, Hinrich

2018-02-01

In tokamaks plasmas, turbulent transport is triggered above a threshold in the temperature gradient and leads to stiff profiles. This particularity, neglected so far in the problem of magnetic island stabilization by a localized heat source, is investigated analytically in this paper. We show that the efficiency of the stabilization is deeply modified compared to the previous estimates due to the strong dependence of the turbulence level on the additional heat source amplitude inside the island.

A Numerical Study on Impact of Taiwan Island Surface Heat Flux on Super Typhoon Haitang (2005

Directory of Open Access Journals (Sweden)

Hongxiong Xu

2015-01-01

Full Text Available Three to four tropical cyclones (TCs by average usually impact Taiwan every year. This study, using the Developmental Tested Center (DTC version of the Hurricane WRF (HWRF model, examines the effects of Taiwan’s island surface heat fluxes on typhoon structure, intensity, track, and its rainfall over the island. The numerical simulation successfully reproduced the structure and intensity of super Typhoon Haitang. The model, especially, reproduced the looped path and landfall at nearly the right position. Sensitive experiments indicated that Taiwan’s surface heat fluxes have significant influence on the super Typhoon Haitang. Compared to sensible heat (SH fluxes, latent heat (LH is the dominant factor affecting the intensity and rainfall, but they showed opposite effects on intensity and rainfall. LH (SH flux of Taiwan Island intensified (weakened Typhoon Haitang’s intensity and structure by transferring more energy from (to surface. However, only LH played a major role in the looped path before the landfall of the Typhoon Haitang.

Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling: Preprint

Energy Technology Data Exchange (ETDEWEB)

Lustbader, Jason; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory; Adelman, Steve; Yeakel, Skip; Luo, Zhiming; Zehme, John

2016-03-24

Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

Urban Heat Island Versus Air Quality - a Numerical Modelling Study for a European City

Science.gov (United States)

Fallmann, J.; Forkel, R.; Emeis, S.

2014-12-01

In 2050 70% of the global population is expected to live in urban areas. Climate change will render these areas more vulnerable to heat waves, which often are accompanied by severe air pollution problems. The Urban Heat Island (UHI) is a feature that adds to the general temperature increase that is expected. Decreasing the UHI can impact air quality as well, because heat influences atmospheric dynamics and accelerates air chemical processes and often also increases the emission of primary pollutants due to increased demand of energy. The goal of this study is to investigate the effect of, e.g., high reflective surfaces and urban greening on mitigating the UHI and the related impact on air quality. A multi-layer urban canopy model is coupled to the mesoscale model WRF-Chem and the urban area of Stuttgart (South-West Germany) is taken as one example. Different scenario runs are executed for short time periods and are compared to a control run. The results show that the UHI effect can be substantially reduced when changing the albedo of roof surfaces, whereas the effect of urban greening is minor. Both scenarios have in common, that they evoke changes in secondary circulation patterns. The effects of these mitigation strategies on chemical composition of the urban atmosphere are complex, attributed to both chemical and dynamical features. Increasing the reflectivity of roof surfaces in the model results in a net decrease of the surface ozone concentration, because ozone formation is highly correlated to temperature. With regard to primary pollutants, e.g. NO, CO and PM10 concentrations are increased when increasing reflectivity. This effect primarily can be ascribed to a reduction of turbulent motion, convection and a decrease of the boundary layer height, coming along with lower temperatures in the urban canopy layer due to increased reflectivity. The table below shows the effect on grid cell mean concentrations for different chemical species and scenarios.

Heat Saving Strategies in Sustainable Smart Energy Systems

DEFF Research Database (Denmark)

Lund, Henrik; Thellufsen, Jakob Zinck; Aggerholm, Søren

that a least‐cost strategy will be to provide approximately 2/3 of the heat demand from district heating and the rest from individual heat pumps. Keywords: Energy Efficiency, Renewable energy, Heating strategy, Heat savings, District heating, Smart energy......One of the important issues related to the implementation of future sustainable smart energy systems based on renewable energy sources is the heating of buildings. Especially, when it comes to long‐term investment in savings and heating infrastructures it is essential to identify long‐term least......‐cost strategies. With Denmark as a case, this paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used. Based on a concrete proposal to implement the Danish governmental long...

Satellite and ground-based sensors for the Urban Heat Island analysis in the city of Rome

DEFF Research Database (Denmark)

Fabrizi, Roberto; Bonafoni, Stefania; Biondi, Riccardo

2010-01-01

In this work, the trend of the Urban Heat Island (UHI) of Rome is analyzed by both ground-based weather stations and a satellite-based infrared sensor. First, we have developed a suitable algorithm employing satellite brightness temperatures for the estimation of the air temperature belonging...... and nighttime scenes taken between 2003 and 2006 have been processed. Analysis of the Canopy Layer Heat Island (CLHI) during summer months reveals a mean growth in magnitude of 3-4 K during nighttime and a negative or almost zero CLHI intensity during daytime, confirmed by the weather stations. © 2010...... by the authors; licensee MDPI, Basel, Switzerland. Keyword: Thermal pollution,Summer months,Advanced-along track scanning radiometers,Urban heat island,Remote sensing,Canopy layer,Atmospheric temperature,Ground based sensors,Weather information services,Satellite remote sensing,Infra-red sensor,Weather stations...

The footprint of urban heat island effect in China

Science.gov (United States)

Decheng Zhou; Shuqing Zhao; Liangxia Zhang; Ge Sun; Yongqiang Liu

2015-01-01

Urban heat island (UHI) is one major anthropogenic modification to the Earth system that transcends its physical boundary. Using MODIS data from 2003 to 2012, we showed that the UHI effect decayed exponentially toward rural areas for majority of the 32 Chinese cities. We found an obvious urban/ rural temperature “cliff”, and estimated that the footprint of UHI effect (...

Radial electric field and transport near the rational surface and the magnetic island in LHD

International Nuclear Information System (INIS)

Ida, K.; Inagaki, S.; Tamura, N.

2002-10-01

The structure of the radial electric field and heat transport at the magnetic island in the Large Helical Device is investigated by measuring the radial profile of poloidal flow with charge exchange spectroscopy. The convective poloidal flow inside the island is observed when the n/m=1/1 external perturbation field becomes large enough to increase the magnetic island width above a critical value (15-20% of minor radius) in LHD. This convective poloidal flow results in a non-flat space potential inside the magnetic island. The sign of the curvature of the space potential depends on the radial electric field at the boundary of the magnetic island. The heat transport inside the magnetic island is studied with a cold pulse propagation technique. The experimental results show the existence of the radial electric field shear at the boundary of the magnetic island and a reduction of heat transport inside the magnetic island. (author)

26 CFR 1.934-1 - Limitation on reduction in income tax liability incurred to the Virgin Islands.

Science.gov (United States)

2010-04-01

... § 1.934-1 Limitation on reduction in income tax liability incurred to the Virgin Islands. (a) General... Islands will be computed as follows: (A) Add to the income tax liability incurred to the Virgin Islands... income from such sources. (ii) Limitation. Tax liability incurred to the Virgin Islands attributable to...

[Applicability of traditional landscape metrics in evaluating urban heat island effect].

Science.gov (United States)

Chen, Ai-Lian; Sun, Ran-Hao; Chen, Li-Ding

2012-08-01

By using 24 landscape metrics, this paper evaluated the urban heat island effect in parts of Beijing downtown area. QuickBird (QB) images were used to extract the landscape type information, and the thermal bands from Landsat Enhanced Thematic Mapper Plus (ETM+) images were used to extract the land surface temperature (LST) in four seasons of the same year. The 24 landscape pattern metrics were calculated at landscape and class levels in a fixed window with 120 mx 120 m in size, with the applicability of these traditional landscape metrics in evaluating the urban heat island effect examined. Among the 24 landscape metrics, only the percentage composition of landscape (PLAND), patch density (PD), largest patch index (LPI), coefficient of Euclidean nearest-neighbor distance variance (ENN_CV), and landscape division index (DIVISION) at landscape level were significantly correlated with the LST in March, May, and November, and the PLAND, LPI, DIVISION, percentage of like adjacencies, and interspersion and juxtaposition index at class level showed significant correlations with the LST in March, May, July, and December, especially in July. Some metrics such as PD, edge density, clumpiness index, patch cohesion index, effective mesh size, splitting index, aggregation index, and normalized landscape shape index showed varying correlations with the LST at different class levels. The traditional landscape metrics could not be appropriate in evaluating the effects of river on LST, while some of the metrics could be useful in characterizing urban LST and analyzing the urban heat island effect, but screening and examining should be made on the metrics.

Urban Heat Island phenomenon in extreme continental climate (Astana, Kazakhstan)

Science.gov (United States)

Konstantinov, Pavel; Akhmetova, Alina

2015-04-01

Urban Heat Island (UHI) phenomenon is well known in scientific literature since first half of the 19th century [1]. By now a wide number of world capitals is described from climatological point of view, especially in mid-latitudes. In beginning of XXI century new studies focus on heat island of tropical cities. However dynamics UHI in extreme continental climates is insufficiently investigated, due to the fact that there isn't large cities in Europe and Northern America within that climate type. In this paper we investigate seasonal and diurnal dynamics UHI intensity for Astana, capital city of Kazakhstan (population larger than 835 000 within the city) including UHI intensity changes on different time scales. Now (since 1998) Astana is the second coldest capital city in the world after Ulaanbaatar, Mongolia [3] For this study we use the UHI investigation technology, described in [2]. According to this paper, we selected three stations: one located into city in high and midrise buildings area (including extensive lowrise and high-energy industrial - LCZ classification) and two others located in rural site (sparsely built or open-set and lightweight lowrise according LCZ classification). Also these stations must be close by distance (less than 100 km) and altitude. Therefore, first for Astana city were obtained numerical evaluations for UHI climate dynamics, UHI dependence of synoptic situations and total UHI climatology on monthly and daily averages. References: 1.Howard, L. (1833) The Climate of London, Deduced from Meteorological Observations. Volume 2, London. 2.Kukanova E.A., Konstantinov P.I. An urban heat islands climatology in Russia and linkages to the climate change In Geophysical Research Abstracts, volume 16 of EGU General Assembly, pages EGU2014-10833-1, Germany, 2014. Germany. 3.www.pogoda.ru.net

Exploring the Urban Heat Island (UHI) Effect in Port Louis, Mauritius

African Journals Online (AJOL)

2012r

2014-10-13

Oct 13, 2014 ... namely: environmental contamination stemming from traffic congestion, the ... problem of UHI may become a more important issue than global warming because the rate of ..... MIGRATION, population distribution and development in the world. ... Urban Heat Island and Climate Change: An Assessment of.

MONITORING SPATIOTEMPORAL CHANGES OF HEAT ISLAND IN BABOL CITY DUE TO LAND USE CHANGES

Directory of Open Access Journals (Sweden)

S. K. Alavi Panah

2017-09-01

Full Text Available Urban heat island is one of the most vital environmental risks in urban areas. The advent of remote sensing technology provides better visibility due to the integrated view, low-cost, fast and effective way to study and monitor environmental and humanistic changes. The aim of this study is a spatiotemporal evaluation of land use changes and the heat island in the time period of 1985-2015 for the studied area in the city of Babol. For this purpose, multi-temporal Landsat images were used in this study. For calculating the land surface temperature (LST, single-channel and maximum likelihood algorithms were used, to classify Images. Therefore, land use changes and LST were examined, and thereby the relationship between land-use changes was analyzed with the normalized LST. By using the average and standard deviation of normalized thermal images, the area was divided into five temperature categories, inter alia, very low, low, medium, high and very high and then, the heat island changes in the studied time period were investigated. The results indicate that land use changes for built-up lands increased by 92%, and a noticeable decrease was observed for agricultural lands. The Built-up land changes trend has direct relation with the trend of normalized surface temperature changes. Low and very low-temperature categories which follow a decreasing trend, are related to lands far away from the city. Also, high and very high-temperature categories whose areas increase annually, are adjacent to the city center and exit ways of the town. The results emphasize on the importance of attention of urban planners and managers to the urban heat island as an environmental risk.

Monitoring Spatiotemporal Changes of Heat Island in Babol City due to Land Use Changes

Science.gov (United States)

Alavi Panah, S. K.; Kiavarz Mogaddam, M.; Karimi Firozjaei, M.

2017-09-01

Urban heat island is one of the most vital environmental risks in urban areas. The advent of remote sensing technology provides better visibility due to the integrated view, low-cost, fast and effective way to study and monitor environmental and humanistic changes. The aim of this study is a spatiotemporal evaluation of land use changes and the heat island in the time period of 1985-2015 for the studied area in the city of Babol. For this purpose, multi-temporal Landsat images were used in this study. For calculating the land surface temperature (LST), single-channel and maximum likelihood algorithms were used, to classify Images. Therefore, land use changes and LST were examined, and thereby the relationship between land-use changes was analyzed with the normalized LST. By using the average and standard deviation of normalized thermal images, the area was divided into five temperature categories, inter alia, very low, low, medium, high and very high and then, the heat island changes in the studied time period were investigated. The results indicate that land use changes for built-up lands increased by 92%, and a noticeable decrease was observed for agricultural lands. The Built-up land changes trend has direct relation with the trend of normalized surface temperature changes. Low and very low-temperature categories which follow a decreasing trend, are related to lands far away from the city. Also, high and very high-temperature categories whose areas increase annually, are adjacent to the city center and exit ways of the town. The results emphasize on the importance of attention of urban planners and managers to the urban heat island as an environmental risk.

Agriculture and irrigation as potential drivers of urban heat island

Science.gov (United States)

Kumar, R.; Buzan, J. R.; Mishra, V.; Kumar, R.; Shindell, D. T.; Huber, M.

2017-12-01

More than half the population are urban dwellers and are most vulnerable to global environmental changes. Urban extents are more prone to intense heating as compared to the surroundings rural area. Presently about 33% of India's population lives in the urban area and is expected to rise steeply, so a better understanding of the phenomenon affecting the urban population is very much important. Urban Heat Island (UHI) is a well-known phenomenon which potentially affects energy consumption, spreading of diseases and mortality. In general, almost all (90%) of the major urban area of the country faces UHI at night time in the range (1-5 °C) while 60% of the regions face Urban Cool Island (UCI) in the range of -1 to 6 °C in day time. Our observations and simulations show that vegetation and irrigation in the surrounding non urban directly affects day time Urban Cool Island effects. This is due to the relative cooling by vegetation and irrigated lands in the vicinity of these urban regions. There is a contrasting variation in UHI/UCI intensities in different seasons and in different time of the day. Most of the urban regions face UHI effect in summers whereas this phenomenton reverses in winters. Daytime UCI is more prominent in the months of April and May due to minimum availability of moisture. We observed that apart from vegetation and irrigation, aerosol is also an important factor governing UHI phenomenon.

The Urban Heat Island Effect and the Role of Vegetation to Address the Negative Impacts of Local Climate Changes in a Small Brazilian City

Directory of Open Access Journals (Sweden)

Elis Dener Lima Alves

2017-02-01

Full Text Available This study analyzes the influence of urban-geographical variables on determining heat islands and proposes a model to estimate and spatialize the maximum intensity of urban heat islands (UHI. Simulations of the UHI based on the increase of normalized difference vegetation index (NDVI, using multiple linear regression, in Iporá (Brazil are also presented. The results showed that the UHI intensity of this small city tended to be lower than that of bigger cities. Urban geometry and vegetation (UI and NDVI were the variables that contributed the most to explain the variability of the maximum UHI intensity. It was observed that areas located in valleys had lower thermal values, suggesting a cool island effect. With the increase in NDVI in the central area of a maximum UHI, there was a significant decrease in its intensity and size (a 45% area reduction. It is noteworthy that it was possible to spatialize the UHI to the whole urban area by using multiple linear regression, providing an analysis of the urban set from urban-geographical variables and thus performing prognostic simulations that can be adapted to other small tropical cities.

FY1995 comprehensive assessments of measures mitigating heat island phenomena in urban areas; 1995 nendo heat shinku wo riyoshita daikibo reibo system no kaihatsu (daitoshi ni okeru kaki koonka taisaku gijutsu no hyoka shuho)

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The urban heat-island phenomenon is one of the man-made changes of local climate. The objectives of this research are to develop a heat-island model to cover the building scale to mesoscale and to assess the countermeasures to heat- island effects. The analysis of Tokyo by remote-sensing, field observation and estimates of anthropogenically exhausted heat using energy consumption data were conducted. And, techniques to assess the most effective countermeasure against the urban warming were developed. (NEDO)

Role of City Texture in Urban Heat Islands at Nighttime

Science.gov (United States)

Sobstyl, J. M.; Emig, T.; Qomi, M. J. Abdolhosseini; Ulm, F.-J.; Pellenq, R. J.-M.

2018-03-01

An urban heat island (UHI) is a climate phenomenon that results in an increased air temperature in cities when compared to their rural surroundings. In this Letter, the dependence of an UHI on urban geometry is studied. Multiyear urban-rural temperature differences and building footprints data combined with a heat radiation scaling model are used to demonstrate for more than 50 cities worldwide that city texture—measured by a building distribution function and the sky view factor—explains city-to-city variations in nocturnal UHIs. Our results show a strong correlation between nocturnal UHIs and the city texture.

Energy Transition Initiative: Island Energy Snapshot - St. Lucia (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2015-02-01

This profile provides a snapshot of the electricity generation or reduction technologies, including solar hot water heating, available to Saint Lucia, one of six Caribbean countries that make up the Windward Islands - the southern arc of the Lesser Antilles chain - at the eastern end of the Caribbean Sea. Heating and transportation fuels are not addressed.

Strong contributions of local background climate to urban heat islands

Science.gov (United States)

Zhao, Lei; Lee, Xuhui; Smith, Ronald B.; Oleson, Keith

2014-07-01

The urban heat island (UHI), a common phenomenon in which surface temperatures are higher in urban areas than in surrounding rural areas, represents one of the most significant human-induced changes to Earth's surface climate. Even though they are localized hotspots in the landscape, UHIs have a profound impact on the lives of urban residents, who comprise more than half of the world's population. A barrier to UHI mitigation is the lack of quantitative attribution of the various contributions to UHI intensity (expressed as the temperature difference between urban and rural areas, ΔT). A common perception is that reduction in evaporative cooling in urban land is the dominant driver of ΔT (ref. 5). Here we use a climate model to show that, for cities across North America, geographic variations in daytime ΔT are largely explained by variations in the efficiency with which urban and rural areas convect heat to the lower atmosphere. If urban areas are aerodynamically smoother than surrounding rural areas, urban heat dissipation is relatively less efficient and urban warming occurs (and vice versa). This convection effect depends on the local background climate, increasing daytime ΔT by 3.0 +/- 0.3 kelvin (mean and standard error) in humid climates but decreasing ΔT by 1.5 +/- 0.2 kelvin in dry climates. In the humid eastern United States, there is evidence of higher ΔT in drier years. These relationships imply that UHIs will exacerbate heatwave stress on human health in wet climates where high temperature effects are already compounded by high air humidity and in drier years when positive temperature anomalies may be reinforced by a precipitation-temperature feedback. Our results support albedo management as a viable means of reducing ΔT on large scales.

Woodfuel procurement strategies of district heating plants

International Nuclear Information System (INIS)

Roos, A.; Bohlin, F.; Hektor, B.; Hillring, B.

2003-01-01

Woodfuel use in the Swedish district heating sector increased significantly from 1985 to 1999. This study analysed strategies and considerations concerning woodfuel procurement in district heating plants. Priorities and concerns in the industry involved an increased woodfuel share, ambitions to create an environmental image, cost minimisation, awareness about the role of energy policies for fuel choice, improvement of woodfuel quality and the ambition to maintain a competitive woodfuel market with several suppliers. Factor analysis yielded five dimensions in the woodfuel procurement strategies among the district heating companies: (1) increased woodfuel use; (2) import; (3) spot market woodfuel purchases; (4) focus on refined woodfuels; and (5) using price only when deciding whether to use woodfuels or other fuels. Five clusters were defined along the three strategy dimensions (1)-(3). The clusters differed concerning size, experiences from the introduction of woodfuels, perceptions about woodfuels and strategies employed to date. This paper describes different strategies that the district heating companies apply on the woodfuel market. The conclusion is that policies should consider this diversity in procurement strategies, mitigate their negative side-effects and assist to make them cost-effective. (author)

The Impact of the Urban Heat Island during an Intense Heat Wave in Oklahoma City

Directory of Open Access Journals (Sweden)

Jeffrey B. Basara

2010-01-01

Full Text Available During late July and early August 2008, an intense heat wave occurred in Oklahoma City. To quantify the impact of the urban heat island (UHI in Oklahoma City on observed and apparent temperature conditions during the heat wave event, this study used observations from 46 locations in and around Oklahoma City. The methodology utilized composite values of atmospheric conditions for three primary categories defined by population and general land use: rural, suburban, and urban. The results of the analyses demonstrated that a consistent UHI existed during the study period whereby the composite temperature values within the urban core were approximately 0.5∘C warmer during the day than the rural areas and over 2∘C warmer at night. Further, when the warmer temperatures were combined with ambient humidity conditions, the composite values consistently revealed even warmer heat-related variables within the urban environment as compared with the rural zone.

Control strategies for gas turbine generators for grid connected and islanding operations

DEFF Research Database (Denmark)

Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

2010-01-01

fine while a DG is connected to a grid, might not work as desired while it is islanded and vise versa. This paper presents a strategy to operate distribution systems with a small gas turbine generator (GTG), which is capable of supplying local loads, in both islanding and grid connected conditions...

Energy reduction potential from the shift to electric vehicles: The Flores island case study

International Nuclear Information System (INIS)

Pina, André; Baptista, Patrícia; Silva, Carlos; Ferrão, Paulo

2014-01-01

The increase of fossil fuel demand raises concerns on availability of resources for future energy demand and on potential environmental impacts. Electric vehicles (EVs) appear as one alternative to shift from fossil fuels to renewable energy resources. This research work analyzes the benefits of the introduction of EVs in a small energy system, the Flores island, Azores, in terms of primary energy and CO 2 emissions. Four scenarios were designed considering different penetration rates of EVs (Low and High) and different time of recharging strategies (Fixed and Flexible). The high shares of RES in the electricity production system (60–62%) did not guarantee a significant use of RES for the recharging of EVs (10–40%), as the additional electricity required had to be produced mainly from the diesel generators. The flexible recharging strategies allowed doubling the share of RES in the recharging of the EVs when compared to fixed recharging, and consequently double the impact on the reduction of primary energy consumption and fossil fuels imports. While the reduction of primary energy ranged between 0.2% and 1.1%, for CO 2 emissions there was a decrease between 0.3 and 1.7%, proving that EVs can help improve the sustainability of energy systems. - highlights: • High shares of RES in electricity do not guarantee a low energy use by EVs. • The introduction of EVs can help reduce CO 2 emissions by 11% in 2030. • Flexible time of recharging strategies allows a 2.5 times higher share of RES

Operation strategy analysis of a geothermal step utilization heating system

International Nuclear Information System (INIS)

Zheng, Guozhong; Li, Feng; Tian, Zhe; Zhu, Neng; Li, Qianru; Zhu, Han

2012-01-01

Geothermal energy has been successfully applied in many district heating systems. In order to promote better use of geothermal energy, it is important to analyze the operation strategy of geothermal heating system. This study proposes a comprehensive and systematic operation strategy for a geothermal step utilization heating system (GSUHS). Calculation models of radiator heating system (RHS), radiant floor heating system (RFHS), heat pump (HP), gas boiler (GB), plate heat exchanger (PHE) and pump are first established. Then the operation strategy of the GSUHS is analyzed with the aim to substantially reduce the conventional energy consumption of the whole system. Finally, the energy efficiency and geothermal tail water temperature are analyzed. With the operation strategy in this study, the geothermal energy provides the main heating amount for the system. The heating seasonal performance factor is 15.93. Compared with coal-fired heating, 75.1% of the standard coal equivalent can be saved. The results provide scientific guidance for the application of an operation strategy for a geothermal step utilization heating system. -- Highlights: ► We establish calculation models for the geothermal step utilization heating system. ► We adopt minimal conventional energy consumption to determine the operation strategy. ► The geothermal energy dominates the heating quantity of the whole system. ► The utilization efficiency of the geothermal energy is high. ► The results provide guidance to conduct operation strategy for scientific operation.

Opportunities for Saving Energy and Improving Air Quality in Urban Heat Islands

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hashem

2007-07-01

World energy use is the main contributor to atmospheric CO2. In 2002, about 7.0 giga metric tons of carbon (GtC) were emitted internationally by combustion of gas, liquid, and solid fuels (CDIAC, 2006), 2 to 5 times the amount contributed by deforestation (Brown et al., 1988). The share of atmospheric carbon emissions for the United States from fossil fuel combustion was 1.6 GtC. Increasing use of fossil fuel and deforestation together have raised atmospheric CO{sub 2} concentration some 25% over the last 150 years. According to global climate models and preliminary measurements, these changes in the composition of the atmosphere have already begun raising the Earth's average temperature. If current energy trends continue, these changes could drastically alter the Earth's temperature, with unknown but potentially catastrophic physical and political consequences. During the last three decades, increased energy awareness has led to conservation efforts and leveling of energy consumption in the industrialized countries. An important byproduct of this reduced energy use is the lowering of CO{sub 2} emissions. Of all electricity generated in the United States, about one-sixth is used to air-condition buildings. The air-conditioning use is about 400 tera-watt-hours (TWh), equivalent to about 80 million metric tons of carbon (MtC) emissions, and translating to about $40 billion (B) per year. Of this $40 B/year, about half is used in cities that have pronounced 'heat islands'. The contribution of the urban heat island to the air-conditioning demand has increased over the last 40 years and it is currently at about 10%. Metropolitan areas in the United States (e.g., Los Angeles, Phoenix, Houston, Atlanta, and New York City) have typically pronounced heat islands that warrant special attention by anyone concerned with broad-scale energy efficiency (HIG, 2006). The ambient air is primarily heated through three processes: direct absorption of solar radiation

Thermal signatures of urban land cover types: High-resolution thermal infrared remote sensing of urban heat island in Huntsville, AL

Science.gov (United States)

Lo, Chor Pang

1996-01-01

The main objective of this research is to apply airborne high-resolution thermal infrared imagery for urban heat island studies, using Huntsville, AL, a medium-sized American city, as the study area. The occurrence of urban heat islands represents human-induced urban/rural contrast, which is caused by deforestation and the replacement of the land surface by non-evaporating and non-porous materials such as asphalt and concrete. The result is reduced evapotranspiration and more rapid runoff of rain water. The urban landscape forms a canopy acting as a transitional zone between the atmosphere and the land surface. The composition and structure of this canopy have a significant impact on the thermal behavior of the urban environment. Research on the trends of surface temperature at rapidly growing urban sites in the United States during the last 30 to 50 years suggests that significant urban heat island effects have caused the temperatures at these sites to rise by 1 to 2 C. Urban heat islands have caused changes in urban precipitation and temperature that are at least similar to, if not greater than, those predicted to develop over the next 100 years by global change models. Satellite remote sensing, particularly NOAA AVHRR thermal data, has been used in the study of urban heat islands. Because of the low spatial resolution (1.1 km at nadir) of the AVHRR data, these studies can only examine and map the phenomenon at the macro-level. The present research provides the rare opportunity to utilize 5-meter thermal infrared data acquired from an airplane to characterize more accurately the thermal responses of different land cover types in the urban landscape as input to urban heat island studies.

Heat Saving Strategies in Sustainable Smart Energy Systems

DEFF Research Database (Denmark)

Lund, Henrik; Thellufsen, Jakob Zinck; Aggerholm, Søren

2014-01-01

This paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used in future sustainable smart energy systems. Based on a concrete proposal to implement the Danish...... governmental 2050 fossil-free vision, this paper identifies marginal heat production costs and compares these to marginal heat savings costs for two different levels of district heating. A suitable least-cost heating strategy seems to be to invest in an approximately 50% decrease in net heat demands in new...... buildings and buildings that are being renovated anyway, while the implementation of heat savings in buildings that are not being renovated hardly pays. Moreover, the analysis points in the direction that a least-cost strategy will be to provide approximately 2/3 of the heat demand from district heating...

Heat Saving Strategies in Sustainable Smart Energy Systems

Directory of Open Access Journals (Sweden)

Henrik Lund

2014-06-01

Full Text Available This paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used in future sustainable smart energy systems. Based on a concrete proposal to implement the Danish governmental 2050 fossil-free vision, this paper identifies marginal heat production costs and compares these to marginal heat savings costs for two different levels of district heating. A suitable least-cost heating strategy seems to be to invest in an approximately 50% decrease in net heat demands in new buildings and buildings that are being renovated anyway, while the implementation of heat savings in buildings that are not being renovated hardly pays. Moreover, the analysis points in the direction that a least-cost strategy will be to provide approximately 2/3 of the heat demand from district heating and the rest from individual heat pumps.

The urban climate: urban heat island of Salamanca El clima de las ciudades: isla de calor de Salamanca

Directory of Open Access Journals (Sweden)

Mª Salud Alonso García

2004-12-01

Full Text Available We have determined the existence of the urban heat island (UHI in a medium-sized city, with an extreme climate and few important foci of industrial pollution. It was seen that urban warming can arise in cities of these characteristics, being able to influence in the alive beings of the zone. By comparing the temperature series in an urban area and those from a nearby rural area, we studied the temporal evolution of the intensity of the UHI for the three-year period between 1996 and 1998. We detected two phenomenons: nocturnal heat island, when the difference of temperature between city and rural zone is positive, and diurnal heat island, when is negative. The most intense nocturnal heat island was seen in autumn, and the most intense diurnal heat island was seen in spring. Statistical study of the annual series corresponding to the night-time heat island permits a definition for Salamanca: a weak island, such as the one showing an intensity lower than 2.0 oC, a moderate island, if the intensity lies between 2.0 oC and 4.0 oC, and an intense island when a values greater than 4.0 oC is passed.En este trabajo se ha determinado la existencia de la isla de calor urbana (ICU, en una ciudad de tamaño medio, con un clima extremado y focos industriales de poca actividad. Con lo que se puede comprobar cómo afecta el calentamiento urbano a ciudades de estas características, pudiendo influir en los seres vivos de la zona. La existencia del fenómeno isla de calor, y su evolución en el tiempo, se han observado comparando los datos de temperatura registrados en una estación meteorológica situada en la ciudad, con los de otra estación fuera del radio de acción de la urbe, durante el período 1996-1998. Se han detectado dos fenómenos: la isla de calor nocturna, cuando la diferencia térmica entre la ciudad y la zona rural es positiva, que presenta sus valores más altos en otoño, y la isla de calor diurna, cuando la diferencia es negativa, que

Spatial Heat Planning and Heat Demand Reductions in Buildings

DEFF Research Database (Denmark)

Nielsen, Steffen

2013-01-01

to an energy system based 100% on renewable energy is not just a fi-ne-tuning of the existing system, but is a fundamental change of the entire energy system. However, similar to the use of fossil fuels, biomass re-sources, which account of a large share of the renewable energy sources, are limited in relation...... long-term savings in investments in production capacity and fuel costs. Through a case study, the amount of these long-term sav-ings is compared to the costs of implementing heat savings. The case study shows that heat reductions of roughly 50% are feasible if the long-term costs are included. Savings...

Satellite-based detection of global urban heat-island temperature influence

Science.gov (United States)

Gallo, K.P.; Adegoke, Jimmy O.; Owen, T.W.; Elvidge, C.D.

2002-01-01

This study utilizes a satellite-based methodology to assess the urban heat-island influence during warm season months for over 4400 stations included in the Global Historical Climatology Network of climate stations. The methodology includes local and regional satellite retrievals of an indicator of the presence green photosynthetically active vegetation at and around the stations. The difference in local and regional samples of the normalized difference vegetation index (NDVI) is used to estimate differences in mean air temperature. Stations classified as urban averaged 0.90??C (N. Hemisphere) and 0.92??C (S. Hemisphere) warmer than the surrounding environment on the basis of the NDVI-derived temperature estimates. Additionally, stations classified as rural averaged 0.19??C (N. Hemisphere) and 0.16??C (S. Hemisphere) warmer than the surrounding environment. The NDVI-derived temperature estimates were found to be in reasonable agreement with temperature differences observed between climate stations. The results suggest that satellite-derived data sets can be used to estimate the urban heat-island temperature influence on a global basis and that a more detailed analysis of rural stations and their surrounding environment may be necessary to assure that temperature trends derived from assumed rural environments are not influenced by changes in land use/land cover. Copyright 2002 by the American Geophysical Union.

On the urban heat island effect dependence on temperature trends

International Nuclear Information System (INIS)

Camilloni, I.; Barros, V.

1997-01-01

For US, Argentine and Australian cities, yearly mean urban to rural temperature differences (ΔT u-r ) and rural temperatures (T r ) are negatively correlated in almost every case, suggesting that urban heat island intensity depends, among other parameters on the temperature itself. This negative correlation is related to the fact that interannual variability of temperature is generally lower in urban environments than in rural areas. This seems to hold true at low frequencies leading to opposite trends in the two variables. Hence, urban stations are prone to have lower trends in absolute value than rural ones. Therefore, regional data sets including records from urban locations, in addition to urban growth bias may have a second type of urban bias associated with temperature trends. A bulk estimate of this second urban bias trend for the contiguous United States during 1901-1984 indicates that it could be of the same order as the urban growth bias and of opposite sign. If these results could be extended to global data, it could be expected that the spurious influence of urban growth on global temperature trends during warming periods will be offset by the diminishing of the urban heat island intensity. 36 refs., 7 figs., 2 tabs

Non-perturbative measurement of cross-field thermal diffusivity reduction at the O-point of 2/1 neoclassical tearing mode islands in the DIII-D tokamak

Energy Technology Data Exchange (ETDEWEB)

Bardóczi, L.; Rhodes, T. L.; Carter, T. A.; Crocker, N. A.; Peebles, W. A. [University of California Los Angeles, Los Angeles, California 90095 (United States); Grierson, B. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2016-05-15

Neoclassical tearing modes (NTMs) often lead to the decrease of plasma performance and can lead to disruptions, which makes them a major impediment in the development of operating scenarios in present toroidal fusion devices. Recent gyrokinetic simulations predict a decrease of plasma turbulence and cross-field transport at the O-point of the islands, which in turn affects the NTM dynamics. In this paper, a heat transport model of magnetic islands employing spatially non-uniform cross-field thermal diffusivity (χ{sub ⊥}) is presented. This model is used to derive χ{sub ⊥} at the O-point from electron temperature data measured across 2/1 NTM islands in DIII-D. It was found that χ{sub ⊥} at the O-point is 1 to 2 orders of magnitude smaller than the background plasma transport, in qualitative agreement with gyrokinetic predictions. As the anomalously large values of χ{sub ⊥} are often attributed to turbulence driven transport, the reduction of the O-point χ{sub ⊥} is consistent with turbulence reduction found in recent experiments. Finally, the implication of reduced χ{sub ⊥} at the O-point on NTM dynamics was investigated using the modified Rutherford equation that predicts a significant effect of reduced χ{sub ⊥} at the O-point on NTM saturation.

Six steps to a successful dose-reduction strategy

International Nuclear Information System (INIS)

Bennett, M.

1995-01-01

The increased importance of demonstrating achievement of the ALARA principle has helped produce a proliferation of dose-reduction ideas. Across a company there may be many dose-reduction items being pursued in a variety of areas. However, companies have a limited amount of resource and, therefore, to ensure funding is directed to those items which will produce the most benefit and that all areas apply a common policy, requires the presence of a dose-reduction strategy. Six steps were identified in formulating the dose-reduction strategy for Rolls-Royce and Associates (RRA): (1) collating the ideas; (2) quantitatively evaluating them on a common basis; (3) prioritizing the ideas in terms of cost benefit, (4) implementation of the highest priority items; (5) monitoring their success; (6) periodically reviewing the strategy. Inherent in producing the dose-reduction strategy has been a comprehensive dose database and the RRA-developed dose management computer code DOMAIN, which allows prediction of dose rates and dose. The database enabled high task dose items to be identified, assisted in evaluating dose benefits, and monitored dose trends once items had been implemented. The DOMAIN code was used both in quantifying some of the project dose benefits and its results, such as dose contours, used in some of the dose-reduction items themselves. In all, over fifty dose-reduction items were evaluated in the strategy process and the items which will give greatest benefit are being implemented. The strategy has been successful in giving renewed impetus and direction to dose-reduction management

Six steps to a successful dose-reduction strategy

Energy Technology Data Exchange (ETDEWEB)

Bennett, M. [Rolls-Royce & Associates Ltd., Derby (United Kingdom)

1995-03-01

The increased importance of demonstrating achievement of the ALARA principle has helped produce a proliferation of dose-reduction ideas. Across a company there may be many dose-reduction items being pursued in a variety of areas. However, companies have a limited amount of resource and, therefore, to ensure funding is directed to those items which will produce the most benefit and that all areas apply a common policy, requires the presence of a dose-reduction strategy. Six steps were identified in formulating the dose-reduction strategy for Rolls-Royce and Associates (RRA): (1) collating the ideas; (2) quantitatively evaluating them on a common basis; (3) prioritizing the ideas in terms of cost benefit, (4) implementation of the highest priority items; (5) monitoring their success; (6) periodically reviewing the strategy. Inherent in producing the dose-reduction strategy has been a comprehensive dose database and the RRA-developed dose management computer code DOMAIN, which allows prediction of dose rates and dose. The database enabled high task dose items to be identified, assisted in evaluating dose benefits, and monitored dose trends once items had been implemented. The DOMAIN code was used both in quantifying some of the project dose benefits and its results, such as dose contours, used in some of the dose-reduction items themselves. In all, over fifty dose-reduction items were evaluated in the strategy process and the items which will give greatest benefit are being implemented. The strategy has been successful in giving renewed impetus and direction to dose-reduction management.

The urban physical environment: temperature and urban heat islands. Chapter 2

Science.gov (United States)

Gordon M. Heisler; Anthony J. Brazel

2010-01-01

The term urban heat island (UHI) describes the phenomenon in which cities are generally warmer than adjacent rural areas. The UHI effect is strongest with skies free of clouds and with low wind speeds. In moist temperate climates, the UHI effect causes cities to be slightly warmer in midday than rural areas, whereas in dry climates, irrigation of vegetation in cites...

Heatwaves and urban heat islands: A comparative analysis of multiple cities

Science.gov (United States)

Ramamurthy, P.; Bou-Zeid, E.

2017-01-01

The recent International Panel on Climate Change report predicts the highly urbanized Northeastern U.S. to be at high risk to heat waves. Since urban residents and infrastructure are known to be highly vulnerable to extreme heat, the goal of this paper is to understand the interaction between the synoptic-scale heat wave and the city-scale urban heat island (UHI) effects. The study also qualitatively analyzes the primary factors that contribute to UHIs by comparing their intensities in different cities with distinct geo-physical characteristics. Our results, generated by using the Weather Research and Forecasting model augmented with advanced urban surface parameterizations, confirm that the amplitude of UHI is related to the physical size of the city. However, the results suggest that cities of comparabale sizes might interact differently with heat waves: in New York City; Washington, DC; and Baltimore (but not in Philadelphia) the regular UHI was amplified more strongly during heat waves compared to smaller cities. The results also establish that the pattern of UHI in different cities, its variability, and its interaction with heat waves are inherently linked to dynamic factors.

Strategies for International Cooperation in Support of Energy Development in Pacific Island Nations

Energy Technology Data Exchange (ETDEWEB)

Miller, M.; Voss, P.; Warren, A.; Baring-Gould, I.; Conrad, M.

2012-05-01

The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) has been partnering with island communities around the world to address the technical, policy, social, and economic hurdles to deploying energy efficiency and renewable energy technologies (RETs) on small, islanded systems. The lessons learned from these partnerships are briefly summarized in this document with the goal of supporting the International Renewable Energy Agency (IRENA) in the development of specific near-term and longer-term strategies for island RET deployment.

Coal-Fired Power Plant Heat Rate Reductions

Science.gov (United States)

View a report that identifies systems and equipment in coal-fired power plants where efficiency improvements can be realized, and provides estimates of the resulting net plant heat rate reductions and costs for implementation.

The use of remotely sensed data as a tool in urban heat island investigations: An overview

Energy Technology Data Exchange (ETDEWEB)

Orvis, K.H.; Akbari, H. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.

1992-01-01

Remotely sensed data contribute an important tool to areawide, cost-effective studies of urban heat island phenomena. This paper provides an overview of its use dating from the first satellite thermal images of urban heat signatures in the early 1970`s, and briefly examines the range of previous uses of remotely sensed data in urban studies, including identification and analysis of heat island effects, modeling of energy budgets, attempts to analyze and classify the urban landscape, and temporal analyses. The intent is not to provide an exhaustive review but rather to describe research trends and patterns. In addition the paper lists an compares those sensing devices that have seen significant use in urban studies and briefly discusses potential strengths and weaknesses of remotely sensed data for use in urban analyses. Three annotated bibliographies, divided by subject, are included. 95 refs.

Gender Differences in the Use of Drug Resistance Strategies: An Analysis of Rural Asian/Pacific Islander Youth

OpenAIRE

Okamoto, Scott K.; Pel, Suzanne; Helm, Susana; Valdez, Jessica

2013-01-01

This study examines gender differences in the use of drug resistance strategies for rural Asian/Pacific Islander youth. Multi-ethnic Asian/Pacific Islander youth (N = 213) from 6 middle/intermediate schools on the Island of Hawai’i participated in the study, and gender differences in their real-world use of specific strategies (e.g., refuse, explain, avoid, leave) were examined. Despite similar levels of exposure to situations where drugs and/or alcohol were offered, girls indicated significa...

The other side of the coin: urban heat islands as shields from extreme cold

Science.gov (United States)

Yang, J.; Bou-Zeid, E.

2017-12-01

Extensive studies focusing on urban heat islands (UHIs) during hot periods create a perception that UHIs are invariably hazardous to human health and the sustainability of cities. Consequently, cities have invested substantial resources to try to mitigate UHIs. These urban policies can have serious repercussions since the health risks associated with cold weather are in fact higher than for heat episodes, yet wintertime UHIs have hardly been explored. We combine ground observations from 12 U.S. cities and high-resolution simulations to show that UHIs not only warm urban areas in the winter, but also further intensify during cold waves by up to 1.32 ± 0.78 oC (mean ± standard deviation) at night. Urban heat islands serve as shelters against extreme colds and provide invaluable benefits of reducing health risks and heating demand. More importantly, our simulations indicate that standard UHI mitigation measures such as green or cool roofs reduce these cold time amenities to different extents. Cities, particularly in cool and cold temperate climates, should hence revisit policies and efforts that are only desgined for hot periods. A paradigm shift is urgently needed to give an equal weight to the wintertime benefits of UHIs in the sustainability and resilience blueprints of cities.

Temperature and heat flow measurements in a fumarolic area: Vulcano Island (Italy)

Energy Technology Data Exchange (ETDEWEB)

Guern, F.L. (Centre des Faibles Radioactivites C.N.R.S., Gifsur Yvette, France); Carbonnelle, J.; D' Amore, F.

1980-01-01

Vulcano, the southern Aeolian Island, is in fumarolic activity. The possibilities of measurements are limited by the field conditions as well as by the technological feasibility. In the present work different tests were made in the field to measure temperature continuously: only the measurements made in dry steam gave good results because they avoid corrosion, and solution of the acid gases in the condensed steam in the ground. Field measurements show that the heat transfer is mainly due to convection. The values obtained in the field can be used to quantify the remote sensing of heat transfer.

Urban heat island and linkage with air quality

International Nuclear Information System (INIS)

Greuillet, C.; Galsomies, L.

2013-01-01

The urban heat island (UHI) effect can be noticed in cities where the temperature is higher than the surrounding countryside, on average 2 deg. C above. In summer during a heat wave, the gap can up to over ten-degree. UHI causes a thermal stress which induces some repercussions on health. The formation of UHI is more and more documented but further studies have to be conducted in order to qualify and quantify the impacts on our health and environment, and the link with atmospheric pollution. Studies have shown air quality deterioration in UHI areas: Both phenomena can be simultaneous because their conditions of appearance are often linked. Henceforth the stake is to manage and if possible reduce UHI to adapt cities to the expected climate change. Dense cities in the future will also have to be naturally cooled down. In order to do so, we will have to act on the most influential UHI formation factors, namely: vegetation and water, buildings (shapes and materials), production and consumption of energy. (authors)

A new islanding detection technique for multiple mini hydro based on rate of change of reactive power and load connecting strategy

International Nuclear Information System (INIS)

Laghari, J.A.; Mokhlis, H.; Bakar, A.H.A.; Karimi, M.

2013-01-01

Highlights: • The requirement of DG interconnection with existing power system is discussed. • Various islanding detection techniques are discussed with their merits and demerits. • New islanding detection strategy is proposed for multiple mini hydro type DGs. • The proposed strategy is based on dq/dt and load connecting strategy. • The effectiveness of strategy is verified on various other cases. - Abstract: The interconnection of distributed generation (DG) into distribution networks is undergoing a rapid global expansion. It enhances the system’s reliability, while simultaneously reduces pollution problems related to the generation of electrical power. To fully utilize the benefits of DGs, certain technical issues need to be addressed. One of the most important issues in this context is islanding detection. This paper presents a new islanding detection technique that is suitable for multiple mini-hydro type DG units. The proposed strategy is based on the rate of change of reactive power and load connecting strategy to detect islanding within the system. For a large power mismatch, islanding is detected by rate of change of reactive power only. However, for a close power mismatch, the rate of change of reactive power initiates a load connecting strategy, which in turn alters the load on the distribution network. This load variation in the distribution network causes a variation in the rate of change of reactive power, which is utilized to distinguish islanding and other events. The simulation results show that the proposed strategy is effective in detecting islanding occurrence in a distribution network

What land covers are effective in mitigating a heat island in urban building rooftop?

Science.gov (United States)

Lee, S.; Ryu, Y.

2014-12-01

Since the 20th century, due to the rapid urbanization many urban environment problems have got blossomed and above all heat island has been recognized as an important issue. There are several causes of urban heat island, but land cover change occupies the largest portion of them. Owing to urban expansion, vegetation is changed into asphalt pavements and concrete buildings, which reduces latent heat flux. To mitigate the problems, people enlarge vegetation covers such as planting street trees, making rooftop gardens and constructing parks or install white roofs that feature high albedo on a building. While the white roofs reflect about 70% of solar radiation and absorb less radiation, vegetation has low albedo but cools the air through transpiration and fixes carbon dioxide through photosynthesis. There are some studies concerning which one is more effective to mitigate heat island between the green roof and white roof. This study compares the green roof and white roof and additionally considers carbon fixation that has not been treated in other studies. Furthermore, this study ascertains an efficiency of solar-cell panel that is used for building roof recently. The panel produces electric power but has low albedo which could warm the air. The experiment is conducted at the rooftop in Seoul, Korea and compares green roof (grass), white roof (painted cover), black roof (solar panel) and normal painted roof. Surface temperature and albedo are observed for the four roof types and incoming shortwave, outgoing longwave and carbon flux are measured in green roof solely. In the case of solar panels, the electricity generation is calculated from the incoming radiation. We compute global warming potentials for the four roof types and test which roof type is most effective in reducing global warming potential.

Retroreflective façades for urban heat island mitigation: Experimental investigation and energy evaluations

International Nuclear Information System (INIS)

Rossi, Federico; Castellani, Beatrice; Presciutti, Andrea; Morini, Elena; Filipponi, Mirko; Nicolini, Andrea; Santamouris, Matheos

2015-01-01

Highlights: • Retro-reflective (RR) materials are an effective strategy for mitigating UHI. • Optical properties of RR materials are assessed by a new experimental facility. • Angular distribution of reflected radiation is assessed during daytime. • RR component is treated as a diffusely reflected radiation by a reduction factor. • An algorithm evaluates the cooling potential of RR materials in urban canyons. - Abstract: The optimization of optical properties of buildings’ envelope and urban paving represents an important research field for reducing the urban heat island effect. The overheating of a surface exposed to sunlight can be reduced by improving solar reflectance. In this sense, several studies have demonstrated the positive effect of cool materials on UHI mitigation. In addition to traditional cool materials, retroreflective (RR) materials have been recently proposed for this application. The present paper aims at the assessment of angular reflectance of RR films for several inclination angles of solar radiation. To reproduce variation of solar radiation’s inclination during the daytime, an ad hoc experimental setup was designed and used. Characterization of RR materials when hit by solar radiation with different inclinations allows to assess their behaviour on daytime if used as novel urban coatings for mitigation of the UHI phenomenon. Measurement results are used as input for an original algorithm which allows to quantify cooling potential of RR materials in terms of energy reflected and sent beyond the urban canyon. The experimental characterization and energy evaluations showed that RR materials could be effectively applied as coatings on urban paving and building envelope, in order to reduce the circulating energy into the canyon

The mitigation effect of configuration and context optimization of urban holdings on heat island

International Nuclear Information System (INIS)

Liu, Y P; Yu, D Y; Xun, B

2014-01-01

The urban heat island (UHI) phenomenon has become a serious problem in recent years. It is necessary to study the mitigation methods and quantify their effects on UHI. In this paper, based on the remote sensed data, an empirical model was established as a negative function of land surface temperature (LST) to vegetation coverage. Urban heat island intensity (UHII) was estimated by a robust statistic algorithm. Compared with the current condition (vegetation coverage equaling to 0%), five high vegetation coverage building scenarios (10%, 20%, 30%, 40%, and 50%) were designed to explore mitigation effects on UHI separately. The results showed that the mean LST increase by about 0.5°C when vegetation coverage decrease by 0.1. UHII has a considerable decrease when the scenarios of vegetation coverage equaling to 20% and 40%, respectively. The reasonable vegetation configuration is the effective UHI mitigation

Device with Complex System for Heat Utilization and Reduction of Hazardous Air Emissions

Directory of Open Access Journals (Sweden)

O. V. Kascheeva

2012-01-01

Full Text Available Investigations concern heat utilization and reduction of hazardous emissions occurring in residential buildings and accompanying operation of a great number of industrial enterprises in particular heat and power objects, and firstly, heat-generating units of small power located in densely populated residential areas without centralized heat supply.The investigation target is to reduce cost of heat produced by independent system of building heat supply, reduction of air pollution  due to hazardous gas emissions and reduction of heat pollution of the environment as a result of building ventilation system operation, ventilation of their internal and external sewerage network and higher reliability of their operation.The target is achieved because the device with complex system for heat utilization and reduction of hazardous air emissions has additionally an assembly tank for mixing flue gases, ventilation emissions and atmospheric air, heat pump. Evaporation zone of the pump is a condensator of the gas mixture and its condensate zone contains a heat supply line for a heat consumer. The line is equipped with assembling  and distributing collectors, pipeline connecting the heat supply line with the system of direct and return delivery water from a boiler house, a separator for division of liquid and gaseous mixture phases, neutralizing devices for separate reduction of concentrations of hazardous and odorous substances being released in gaseous and liquid portions of the mixture, a pipeline for periodic supply of air with higher concentration of hazardous and odorous substances in the boiler furnace. The supplied air is obtained as a result of its passing through gas filters at their regeneration when their exchange capacity is exhausted.

Influence of Urbanization Factors on Surface Urban Heat Island Intensity: A Comparison of Countries at Different Developmental Phases

Directory of Open Access Journals (Sweden)

Yaoping Cui

2016-07-01

Full Text Available Urbanization is a global problem with demographic trends. The urban heat island plays a dominant role in local climate systems. Despite existing efforts to understand the impacts of multiple urbanization factors on the urban heat island globally, very little is known about the attribution of urban heat island magnitude to urbanization in different locations or developmental phases. In this study, based on global land surface temperature data, urban spatial domain data, gross domestic product (GDP, and population data, we analyzed the influence of multiple urbanization factors on global surface urban heat island intensity (SUHII. We also tentatively compared the abovementioned factors between different regions across the globe, especially between China and the USA, the largest countries that are experiencing or have experienced rapid urbanization in recent decades. The results showed that global SUHII had remarkable spatial heterogeneity due to the geographical and socioeconomic variation between cities. There was a significant correlation between SUHII and population as well as GDP in global cities. Moreover, this study suggested that the impacts of population on SUHII might be stronger in the early stages of urbanization, and the GDP factor would become a critical factor at a certain development level. The urban area also had non-ignorable impacts on SUHII, while the correlation between SUHII and urban shape was relatively weak. All these may imply that the best approach to slow down SUHII is to find other solutions, e.g., optimize the spatial configuration of urban internal landscapes, when the urbanization reaches a high level.

A Numerical Study on Impact of Taiwan Island Surface Heat Flux on Super Typhoon Haitang (2005)

OpenAIRE

Xu, Hongxiong

2015-01-01

Three to four tropical cyclones (TCs) by average usually impact Taiwan every year. This study, using the Developmental Tested Center (DTC) version of the Hurricane WRF (HWRF) model, examines the effects of Taiwan’s island surface heat fluxes on typhoon structure, intensity, track, and its rainfall over the island. The numerical simulation successfully reproduced the structure and intensity of super Typhoon Haitang. The model, especially, reproduced the looped path and landfall at nearly the ...

Utilising green and bluespace to mitigate urban heat island intensity.

Science.gov (United States)

Gunawardena, K R; Wells, M J; Kershaw, T

2017-04-15

It has long been recognised that cities exhibit their own microclimate and are typically warmer than the surrounding rural areas. This 'mesoscale' influence is known as the urban heat island (UHI) effect and results largely from modification of surface properties leading to greater absorption of solar radiation, reduced convective cooling and lower water evaporation rates. Cities typically contain less vegetation and bodies of water than rural areas, and existing green and bluespace is often under threat from increasing population densities. This paper presents a meta-analysis of the key ways in which green and bluespace affect both urban canopy- and boundary-layer temperatures, examined from the perspectives of city-planning, urban climatology and climate science. The analysis suggests that the evapotranspiration-based cooling influence of both green and bluespace is primarily relevant for urban canopy-layer conditions, and that tree-dominated greenspace offers the greatest heat stress relief when it is most needed. However, the magnitude and transport of cooling experienced depends on size, spread, and geometry of greenspaces, with some solitary large parks found to offer minimal boundary-layer cooling. Contribution to cooling at the scale of the urban boundary-layer climate is attributed mainly to greenspace increasing surface roughness and thereby improving convection efficiency rather than evaporation. Although bluespace cooling and transport during the day can be substantial, nocturnal warming is highlighted as likely when conditions are most oppressive. However, when both features are employed together they can offer many synergistic ecosystem benefits including cooling. The ways in which green and bluespace infrastructure is applied in future urban growth strategies, particularly in countries expected to experience rapid urbanisation, warrants greater consideration in urban planning policy to mitigate the adverse effects of the UHI and enhance climate

Solar Panels reduce both global warming and Urban Heat Island

Directory of Open Access Journals (Sweden)

Valéry eMasson

2014-06-01

Full Text Available The production of solar energy in cities is clearly a way to diminish our dependency to fossil fuels, and is a good way to mitigate global warming by lowering the emission of greenhouse gases. However, what are the impacts of solar panels locally ? To evaluate their influence on urban weather, it is necessary to parameterize their effects within the surface schemes that are coupled to atmospheric models. The present paper presents a way to implement solar panels in the Town Energy Balance scheme, taking account of the energy production (for thermal and photovoltaic panels, the impact on the building below and feedback towards the urban micro-climate through radiative and convective fluxes. A scenario of large but realistic deployment of solar panels on the Paris metropolitan area is then simulated. It is shown that solar panels, by shading the roofs, slightly increases the need for domestic heating (3%. In summer however, the solar panels reduce the energy needed for air-conditioning (by 12% and also the Urban Heat Island (UHI: 0.2K by day and up to 0.3K at night. These impacts are larger than those found in previous works, because of the use of thermal panels (that are more efficient than photovoltaic panels and the geographical position of Paris, which is relatively far from the sea. This means that it is not influenced by sea breezes, and hence that its UHI is stronger than for a coastal city of the same size. But this also means that local adaptation strategies aiming to decrease the UHI will have more potent effects. In summary, the deployment of solar panels is good both globally, to produce renewable energy (and hence to limit the warming of the climate and locally, to decrease the UHI, especially in summer, when it can constitute a health threat.

Ash reduction system using electrically heated particulate matter filter

Science.gov (United States)

Gonze, Eugene V [Pinckney, MI; Paratore, Jr., Michael J; He, Yongsheng [Sterling Heights, MI

2011-08-16

A control system for reducing ash comprises a temperature estimator module that estimates a temperature of an electrically heated particulate matter (PM) filter. A temperature and position estimator module estimates a position and temperature of an oxidation wave within the electrically heated PM filter. An ash reduction control module adjusts at least one of exhaust flow, fuel and oxygen levels in the electrically heated PM filter to adjust a position of the oxidation wave within the electrically heated PM filter based on the oxidation wave temperature and position.

Urban environment and vegetation: comfort and urban heat island mitigation

Directory of Open Access Journals (Sweden)

Adriano Magliocco

2014-10-01

Full Text Available This paper analyses the outcomes of an experimental simulation on the microclimatic effects and on thermal comfort of vegetation in urban environment, conducted by means of a three-dimensional microclimate model, ENVI- met 3.1. The simulation considers a wide range of hypothetical cases of typical city areas with different characteristics related to: building density, building height, vegetation type and density. The results of the study show how different combinations of amount and type of vegetation, density and height of buildings affect the urban heat island phenomenon in Mediterranean climate.

Reduction of Islands in Full-pressure Stellarator Equilibria

International Nuclear Information System (INIS)

Hudson, S.R.; Monticello, D.A.; Reiman, A.H.

2001-01-01

The control of magnetic islands is a crucial issue in designing Stellarators. Islands are associated with resonant radial magnetic fields at rational rotational-transform surfaces and can lead to chaos and poor plasma confinement. In this article, we show that variations in the resonant fields of a full-pressure stellarator equilibrium can be related to variations in the boundary via a coupling matrix, and inversion of this matrix determines a boundary modification for which the island content is significantly reduced. The numerical procedure is described and the results of island optimization are presented. Equilibria with islands are computed using the Princeton Iterative Equilibrium Solver, and resonant radial fields are calculated via construction of quadratic-flux-minimizing surfaces. A design candidate for the National Compact Stellarator Experiment [Phys. Plasmas 8, 2001], which has a large island, is used to illustrate the technique. Small variations in the boundary shape are used to reduce island size and to reverse the phase of a major island chain

Observing the Vertical Dimensions of Singapore's Urban Heat Island

Science.gov (United States)

Chow, W. T. L.; Ho, D. X. Q.

2015-12-01

In numerous cities, measurements of urban warmth in most urban heat island (UHI) studies are generally constrained towards surface or near-surface (quadcopter platforms to measure urban temperature and humidity profiles in Singapore, which is a rapidly urbanizing major tropical metropolis. These profiles were measured from the surface to ~100 m above ground level, a height which includes all of the urban canopy and parts of the urban boundary layer. Initial results indicate significant variations in stability measured over different land uses (e.g. urban park, high-rise residential, commercial); these profiles are also temporally dynamic, depending on the time of day and larger-scale weather conditions.

NUMERICAL ANALYSIS OF HEAT STORAGE OF SOLAR HEAT IN FLOOR CONSTRUCTION

DEFF Research Database (Denmark)

Weitzmann, Peter; Holck, Ole; Svendsen, Svend

2003-01-01

with the highest energy con-sumption. The reduction depends on the solar collector area, distribution of the insulation thickness, heat-ing demand and control strategy, but not on pipe spacing and layer thickness and material. Finally, it is shown that the system can also be used for comfort heating of tiled...

Graphene oxide reduction by microwave heating

International Nuclear Information System (INIS)

Longo, Angela; Carotenuto, Gianfranco

2016-01-01

The possibility to prepare thermal reduced graphene oxide (Tr-GO) colloidal suspensions by microwave heating of graphene oxide (GO) suspensions in N-methyl-2-pyrrolidone (NMP) has been investigated. According to transmission electron microscopy (TEM) and absorption and emission spectroscopy characterization, such a type of thermal reduction does not lead to graphene quantum dots formation because only mono-functional oxygen-containing groups are removed.

Graphene oxide reduction by microwave heating

Energy Technology Data Exchange (ETDEWEB)

Longo, Angela; Carotenuto, Gianfranco [Institute for Polymers, Composites, and Biomaterials, National Research Council, Piazzale Enrico Fermi 1, 80055 Portici (Italy)

2016-05-18

The possibility to prepare thermal reduced graphene oxide (Tr-GO) colloidal suspensions by microwave heating of graphene oxide (GO) suspensions in N-methyl-2-pyrrolidone (NMP) has been investigated. According to transmission electron microscopy (TEM) and absorption and emission spectroscopy characterization, such a type of thermal reduction does not lead to graphene quantum dots formation because only mono-functional oxygen-containing groups are removed.

Autonomous Control Strategy of DC Microgrid for Islanding Mode Using Power Line Communication

Directory of Open Access Journals (Sweden)

Dong-Keun Jeong

2018-04-01

Full Text Available This paper proposes a DC-bus signaling (DBS method for autonomous power management in a DC microgrid, used to improve its reliability. Centralized power management systems require communication between the power sources and loads. However, the DBS method operates based on the common DC-bus voltage and does not require communication. Based on the DC-bus voltage band, the DC-bus voltage can be used to inform the status of the DC-bus in various scenarios. The DC microgrid operates independently to maintain the system stably in the DC-bus voltage band. The DC microgrid can be divided into a grid-connected mode and an islanding mode. This paper proposes a control strategy based on power management of various independent components in islanding mode. In addition, the autonomous control method for switching the converter’s operation between grid-connected mode and islanding mode is proposed. A DC microgrid test bed consisting of a grid-connected AC/DC converter, a bidirectional DC/DC converter, a renewable energy simulator, DC home appliances and a DC-bus protector is used to test the proposed control strategy. The proposed autonomous control strategy is experimentally verified using the DC microgrid test bed.

Optimized Management of Groundwater Resources in Kish Island: A Sensitivity Analysis of Optimal Strategies in Response to Environmental Changes

Directory of Open Access Journals (Sweden)

Davood Mahmoodzadeh

2016-05-01

Full Text Available Groundwater in coastal areas is an essential source of freshwater that warrants protection from seawater intrusion as a priority based on an optimal management plan. Proper optimal management strategies can be developed using a variety of decision-making models. The present study aims to investigate the impacts of environmental changes on groundwater resources. For this purpose, a combined simulation-optimization model is employed that incorporates the SUTRA numerical model and the evolutionaty method of ant colony optimization. The fresh groundwater lens in Kish Island is used as a case study and different scenarios are considered for the likely enviromental changes. Results indicate that while variations in recharge rate form an important factor in the fresh groundwater lens, land-surface inundation due to rises in seawater level, especially in low-lying lands, is the major factor affecting the lens. Furthermore, impacts of environmental changes when effected into the Kish Island aquifer optimization management plan have led to a reduction of more than 20% in the allowable water extraction, indicating the high sensitivity of groundwater resources management plans in small islands to such variations.

Ozone reduction strategy for the northeastern part of Austria: cooperation and compilation of the fundamentals

International Nuclear Information System (INIS)

Orthofer, R.; Winiwarter, W.

1996-05-01

This report is contribution to the implementation of an ozone reduction strategy for the northeastern part of Austria. The report contains a regional emission inventory, an emission projection for the years 1996, 2001 and 2006, an evaluation of further stationary sources reduction options. The ozone formation potentials of non-methane volatile organic compounds (NMVOC) emissions were calculated separately for both mobile and stationary source group, in order to assess the respective contribution to the local ozone formation. It can be shown that status-quo reduction measures are more efficient in terms of ozone formation potential during the summer season than in terms of NMVOC emission mass reduction. It is recommended that further NMVOC emission control should focus primarily on industrial solvent emissions, domestic heating of water during summertime with solid fuels, and on stubble burning in the fields. (author)

The effect of urban heat island on Izmir's city ecosystem and climate.

Science.gov (United States)

Corumluoglu, Ozsen; Asri, Ibrahim

2015-03-01

Depending on the researches done on urban landscapes, it is found that the heat island intensity caused by the activities in any city has some impact on the ecosystem of the region and on the regional climate. Urban areas located in arid and semiarid lands somehow represent heat increase when it is compared with the heat in the surrounding rural areas. Thus, cities located amid forested and temperate climate regions show moderate temperatures. The impervious surfaces let the rainfall leave the city lands faster than undeveloped areas. This effect reduces water's cooling effects on these lands. More significantly, if trees and other vegetations are rare in any region, it means less evapotranspiration-the process by which trees "exhale" water. Trees also contribute to the cooling of urban lands by their shade. Land cover and land use maps can easily be produced by processing of remote sensing satellites' images, like processing of Landsat's images. As a result of this process, urban regions can be distinguished from vegetation. Analyzed GIS data produced and supported by these images can be utilized to determine the impact of urban land on energy, water, and carbon balances at the Earth's surface. Here in this study, it is found that remote sensing technique with thermal images is a liable technique to asses where urban heat islands and hot spots are located in cities. As an application area, in Izmir, it was found that the whole city was in high level of surface temperature as it was over 28 °C during the summer times. Beside this, the highest temperature values which go up to 47 °C are obtained at industrial regions especially where the iron-steel factories and the related industrial activities are.

PEMBAHASAN MENGENAI EFEK URBAN HEAT ISLAND DAN SOLUSI ALTERNATIF BAGI KOTA JAKARTA

Directory of Open Access Journals (Sweden)

Andrew V Limas

2014-01-01

Full Text Available Hadirnya Jakarta sebagai salah satu kota metropolitan yang berkembang di dunia, menjadikan Jakarta sebagai salah satu kota yang harus diperhitungkan konsistensinya. Letaknya yang berada di daerah tropis serta memiliki angka kepadatan penduduk yang tinggi menciptakan sebuah masalah serius bagi bangunan perkantoran dan perumahan di dalamnya, polemik yang dimaksud adalah adanya “efek pemanasan di daerah perkotaan”. Artikel ini akan membahas definisi dan aplikasi dari sistem “atap hijau” bersamaan dengan keuntungan dan keunikannya dalam menjawab kebutuhan dalam mengurangi tingginya temperatur pada pusat perkantoran dan daerah perumahan di kota Jakarta. Kata Kunci : efek pemanasan daerah perkotaan, kepadatan penduduk, sistem atap hijau Abstract Considering Jakarta as one of the developing metropolitan cities in the world creates, the need to reckon it’s consistency has emerged. Located in a tropical area with  high population density creates a serious problem to its city planning, in other words an urban heat island effect. This paper will discuss the definition and application of a green roof system along with its advantages or uniqueness to answer the need to reduce high temperature in central business district and residental areas for city of Jakarta in particular. Keywords : urban heat island effect, population density, green roof system

Solar heating - status and strategy. Research, development and demonstration; Solvarme - status og strategi. Forskning, udvikling og demonstration

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-05-15

The Danish Energy Authority has prepared research and development strategies for a number of energy technologies, including solar heating. This report presents an inventory of solar heating and proposes a strategy for further development. The report has been prepared by a number of important stakeholders in the Danish solar heating area. The inventory part of the report includes most solar heating technologies, however, emphasis is on technologies which have had or are expected to become important for exploitation in Denmark. The strategy part of the report proposes prioritized areas in research, development and demonstration based on international trends and Danish strong and weak points, which are: 1) centralized solar heating supply, district heating, 2) individual solar heating supply in connection with development and construction of buildings, building integration, and finally 3) product development of solar collectors. (BA)

Sensitivities Affecting Heat and Urban Heat Island Effect on Local Scale Projected to Neighborhood Scale in Baltimore, Maryland

Science.gov (United States)

Sze, C.; Zaitchik, B. F.; Scott, A.

2015-12-01

Urban regions are often impacted more by heat than adjacent rural areas, which is a phenomenon known as the urban heat island (UHI) effect. Urban areas are also highly heterogeneous and notoriously difficult to monitor using standard meteorological protocols—the hottest microclimates within a city often occur in locations that lack open, representative installation sites that are an adequate distance from buildings and direct heat sources. To investigate the challenges of monitoring urban heat, this study examines the sensitivity of temperature and humidity sensors currently used in a Baltimore UHI monitoring network to differences in sun exposure, material on which the data collecting instrument is attached, and land cover class of the vicinity. Sensitivity to sun exposure and attachment site can be interpreted as sources of uncertainty for urban heat monitoring, while sensitivity to land cover may reflect a true source of local temperature and humidity variability. In this study, we present results from a test deployment designed to assess the sensitivity of heat measurements to each of these three factors. We then apply these results to interpret measurements taken across the entire Baltimore UHI monitoring network. These results can then be used to improve heat measurements and more accurately represent and quantify the UHI effect on a broader scale, such as in neighborhoods or urban centers.

Managing heat and immune stress in athletes with evidence-based strategies.

Science.gov (United States)

Pyne, David B; Guy, Joshua H; Edwards, Andrew M

2014-09-01

Heat and immune stress can affect athletes in a wide range of sports and environmental conditions. The classical thermoregulatory model of heat stress has been well characterized, as has a wide range of practical strategies largely centered on cooling and heat-acclimation training. In the last decade evidence has emerged of an inflammatory pathway that can also contribute to heat stress. Studies are now addressing the complex and dynamic interplay between hyperthermia, the coagulation cascade, and a systemic inflammatory response occurring after transient damage to the gastrointestinal tract. Damage to the intestinal mucosal membrane increases permeability, resulting in leakage of endotoxins into the circulation. Practical strategies that target both thermoregulatory and inflammatory causes of heat stress include precooling; short-term heat-acclimation training; nutritional countermeasures including hydration, energy replacement, and probiotic supplementation; pacing strategies during events; and postevent cooling measures. Cooperation between international, national, and local sporting organizations is required to ensure that heat-management policies and strategies are implemented effectively to promote athletes' well-being and performance.

Wintertime urban heat island modified by global climate change over Japan

Science.gov (United States)

Hara, M.

2015-12-01

Urban thermal environment change, especially, surface air temperature (SAT) rise in metropolitan areas, is one of the major recent issues in urban areas. The urban thermal environmental change affects not only human health such as heat stroke, but also increasing infectious disease due to spreading out virus vectors habitat and increase of industry and house energy consumption. The SAT rise is mostly caused by global climate change and urban heat island (hereafter UHI) by urbanization. The population in Tokyo metropolitan area is over 30 millions and the Tokyo metropolitan area is one of the biggest megacities in the world. The temperature rise due to urbanization seems comparable to the global climate change in the major megacities. It is important to project how the urbanization and the global climate change affect to the future change of urban thermal environment to plan the adaptation and mitigation policy. To predict future SAT change in urban scale, we should estimate future UHI modified by the global climate change. This study investigates change in UHI intensity (UHII) of major metropolitan areas in Japan by effects of the global climate change. We performed a series of climate simulations. Present climate simulations with and without urban process are conducted for ten seasons using a high-resolution numerical climate model, the Weather Research and Forecasting (WRF) model. Future climate projections with and without urban process are also conducted. The future projections are performed using the pseudo global warming method, assuming 2050s' initial and boundary conditions estimated by a GCM under the RCP scenario. Simulation results indicated that UHII would be enhanced more than 30% in Tokyo during the night due to the global climate change. The enhancement of urban heat island is mostly caused by change of lower atmospheric stability.

Heat island and spatio-temporal changes of temperature in the city of Bogota

International Nuclear Information System (INIS)

Angel, L; Ramirez, A; Dominguez, E.

2010-01-01

The planet Earth, as a whole, has experienced a warming process caused principally by the accumulation of atmospheric greenhouse gases. Otherwise, it has been well demonstrated that thermic islands exist inside of cities, essentially as a result of the replacement of forest areas with urban materials such as asphalt, concrete, bricks, etc. Based on this foundation, this research evaluated the minimum, median and maximum temperature changes that occurred in the city of Bogota over the last 40 years. This research makes evident the presence of a heat island 3o Cover the periphery median temperature in most of the city. There were also periods with increases and decreases in city temperatures, not affected in its main tendency by the Nino Phenomena which in contrast affected the periphery.

Urban Heat Island and Park Cool Island Intensities in the Coastal City of Aracaju, North-Eastern Brazil

Directory of Open Access Journals (Sweden)

Max Anjos

2017-08-01

Full Text Available In this study, an evaluation of the Urban Heat Island (UHI and Park Cool Island (PCI intensities in Aracaju, North-Eastern Brazil, was performed. The basis of our evaluation is a 2-year dataset from the urban climatological network installed with the principles and concepts defined for urban areas related to climatic scales, sitting and exposure, urban morphology, and metadata. The current findings update UHI intensities in Aracaju refuting the trend registered in previous studies. On average, the UHI was more intense in the cool season (1.3 °C than in hot season (0.5 °C, which was caused by wind speed decrease. In relation to the PCI, mitigation of high air temperatures of 1.5–2 °C on average was registered in the city. However, the urban park is not always cooler than the surrounding built environment. Consistent long-term monitoring in the cities is very important to provide more accurate climatic information about the UHI and PCI to be applied in urban planning properly, e.g., to provide pleasant thermal comfort in urban spaces.

Bibliography of greenhouse-gas reduction strategies

Energy Technology Data Exchange (ETDEWEB)

Tompkins, M.M.; Mintz, M.M.

1995-03-01

A bibliography of greenhouse-gas reduction strategies has been compiled to assist the Climate change Action Plan Task Force in their consideration of strategies to reduce greenhouse-gas emissions from personal motor vehicles. The document contains a summary of the literature, including it major directions and implications; and annotated listing of 32 recent pertinent documents; and a listing of a larger group of related reports.

Shallow geothermal field in Lanzarote (Canary Island). Potential evaluation and heat extraction test

Energy Technology Data Exchange (ETDEWEB)

Diez-Gil, J.L.; Valentin, A. [Consejo Superior de Investigaciones Cientificas, Madrid (Spain); Torres, F. [Universidad de Barcelona (Spain); Albert, J.F.

1994-12-31

Boreholes were used to perform various experiments. A thermometry was carried out, as well as chemical analysis and an hydrodynamic modelling. This paper presents the scientific aims and conclusions of the whole project called ``Shallow H.D.R. geothermal field`` in Lanzarote (Canary Islands). Potential evaluation and heat extraction test are presented. (Project JOUG-0004 ES -JR - JOULE Program of the EEC). (TEC). 2 tabs.

An environmental cost-benefit analysis of alternative green roofing strategies

Science.gov (United States)

Richardson, M.; William, R. K.; Goodwell, A. E.; Le, P. V.; Kumar, P.; Stillwell, A. S.

2016-12-01

Green roofs and cool roofs are alternative roofing strategies that mitigate urban heat island effects and improve building energy performance. Green roofs consist of soil and vegetation layers that provide runoff reduction, thermal insulation, and potential natural habitat, but can require regular maintenance. Cool roofs involve a reflective layer that reflects more sunlight than traditional roofing materials, but require additional insulation during winter months. This study evaluates several roofing strategies in terms of energy performance, urban heat island mitigation, water consumption, and economic cost. We use MLCan, a multi-layer canopy model, to simulate irrigated and non-irrigated green roof cases with shallow and deep soil depths during the spring and early summer of 2012, a drought period in central Illinois. Due to the dry conditions studied, periodic irrigation is implemented in the model to evaluate its effect on evapotranspiration. We simulate traditional and cool roof scenarios by altering surface albedo and omitting vegetation and soil layers. We find that both green roofs and cool roofs significantly reduce surface temperature compared to the traditional roof simulation. Cool roof temperatures always remain below air temperature and, similar to traditional roofs, require low maintenance. Green roofs remain close to air temperature and also provide thermal insulation, runoff reduction, and carbon uptake, but might require irrigation during dry periods. Due to the longer lifetime of a green roof compared to cool and traditional roofs, we find that green roofs realize the highest long term cost savings under simulated conditions. However, using longer-life traditional roof materials (which have a higher upfront cost) can help decrease this price differential, making cool roofs the most affordable option due to the higher maintenance costs associated with green roofs

A Communication-Less Distributed Voltage Control Strategy for a Multi-Bus AC Islanded Microgrid

DEFF Research Database (Denmark)

Wang, Yanbo; Tan, Yongdong; Chen, Zhe

2014-01-01

This paper presents a communication-less distributed voltage control strategy for a multi-bus AC islanded microgrid. First, a Kalman Filter-based network voltage estimator is proposed to obtain voltage responses without communication links in the presence of load disturbances. Then, a voltage...... and reliability is improved for islanded microgrids due to communication-less operation. The simulations and experimental results are presented to validate the proposed distributed voltage control strategy....... optimal controller using MPC (Model Predictive Control) are developed to implement voltage optimal control. The contributions of this paper are demonstrated: (1) The proposed voltage estimator can dynamically obtain network voltage responses just through local voltage and current associated with each DG...

The relation between land-cover and the urban heat island in northeastern Puerto Rico

Science.gov (United States)

David J.R. Murphy; Myrna Hall; Charles Hall; Gordon Heisler; Steve Stehman

2007-01-01

As development continues in Puerto Rico, forests and grasslands are being converted to impervious cover, changing the magnitude and geographic range of the Urban Heat Island (UHI). As part of the U.S. National Science Foundation Long Term Ecological Research Program, this study aims to quantify the various meteorological effects that urbanization may be imparting on...

A TEMPORAL AND SPATIAL ANALYSIS OF URBAN HEAT ISLAND IN BASIN CITY UTILIZING REMOTE SENSING TECHNIQUES

Directory of Open Access Journals (Sweden)

H.-T. Chang

2016-06-01

Full Text Available Urban Heat Island (UHI has been becoming a key factor in deteriorating the urban ecological environment. Spatial-temporal analysis on its prototype of basin city’s UHI and quantitatively evaluating effect from rapid urbanization will provide theoretical foundation for relieving UHI effect. Based on Landsat 8, ETM+ and TM images of Taipei basin areas from 1900 to 2015, this article has retrieved the land surface temperature (LST at summer solstice of each year, and then analysed spatial-temporal pattern and evolution characters of UHI in Taipei basin in this decade. The results showed that the expansion built district, UHI area constantly expanded from centre city to the suburb areas. The prototype of UHI in Taipei basin that showed in addition to higher temperatures in the centre city also were relatively high temperatures gathered boundaries surrounded by foot of mountains side. It calls “sinking heat island”. From 1900 to 2000, the higher UHI areas were different land use type change had obvious difference by public infrastructure works. And then, in next 15 years till 2015, building density of urban area has been increasing gradually. It has the trend that UHI flooding raises follow urban land use density. Hot spot of UHI in Taipei basin also has the same characteristics. The results suggest that anthropogenic heat release probably plays a significant role in the UHI effect, and must be considered in urban planning adaptation strategies.

Exertional heat stroke management strategies in United States high school football.

Science.gov (United States)

Kerr, Zachary Y; Marshall, Stephen W; Comstock, R Dawn; Casa, Douglas J

2014-01-01

The 5-year period of 2005-2009 saw more exertional heat stroke-related deaths in organized sports than any other 5-year period in the past 35 years. The risk of exertional heat stroke appears highest in football, particularly during the preseason. To estimate the incidence of exertional heat stroke events and assess the utilization of exertional heat stroke management strategies during the 2011 preseason in United States high school football programs. Cross-sectional study; Level of evidence, 3. A self-administered online questionnaire addressing the incidence of exertional heat stroke events and utilization of exertional heat stroke management strategies (eg, removing athlete's football equipment, calling Emergency Medical Services [EMS]) was completed in May to June 2012 by 1142 (18.0%) athletic trainers providing care to high school football athletes during the 2011 preseason. Among all respondents, 20.3% reported treating at least 1 exertional heat stroke event. An average of 0.50 ± 1.37 preseason exertional heat stroke events were treated per program. Athletic trainers responding to exertional heat stroke reported using an average of 6.6 ± 1.8 management strategies. The most common management strategies were low-level therapeutic interventions such as removing the athlete's football equipment (98.2%) and clothing (77.8%) and moving the athlete to a shaded area (91.6%). Few athletic trainers reported active management strategies such as calling EMS (29.3%) or using a rectal thermometer to check core body temperature (0.9%). Athletic trainers in states with mandated preseason heat acclimatization guidelines reported a higher utilization of management strategies such as cooling the athlete through air conditioning (90.1% vs 65.0%, respectively; P football programs. The standard of care is (and should be) to treat proactively; therefore, treatment is not a perfect proxy for incidence. Nevertheless, there is an urgent need for improved education and awareness of

TMI-2 [Three Mile Island Unit 2] reactor building dose reduction task force

International Nuclear Information System (INIS)

Daniels, R.S.

1988-01-01

In late October 1982, the director of Three Mile Island Unit 2 (TMI-2) created the dose reduction task force with the objective of identifying the principal radiological sources in the reactor building and recommending actions to minimize the dose to workers on labor-intensive projects. Members of the task force were drawn form various groups at TMI. Findings and recommendations were presented to the US Nuclear Regulatory Commission in a briefing on November 18, 1982. The task force developed a three-step approach toward dose reduction. Step 1 identified the radiological sources. Step 2 modeled the source and estimated its contribution to the general area dose rates. Step 3 recommended actions to achieve dose reductions consistent with general exposure rate goals

Physical model of the dispersion of a radioactive contaminant in the atmosphere above a heat island

International Nuclear Information System (INIS)

Toly, J.A.; Tenchine, D.

1984-01-01

The project deals with the impact of surface heating in urban areas on the dispersion of contaminants in the atmosphere. - The atmospheric boundary layer is simulated in a water flume. Ground heating is applied locally reproducing the heat flux of an urban region. Fission products for which internal heat source is neglected are simulated by horizontal plumes at pHs different from the original pH of the flume. - The main results of the study concern: the characterization of the internal boundary layer downstream of the leading edge of the heated ground; the comparison of the concentration distributions of pollutants with and without surface heating. - A transposition of the results, expressed in terms of global parameters, enables information on the heat island effect due to urban regions on the dispersion of contaminants in the atmosphere to be obtained

Positive effects of vegetation: Urban heat island and green roofs

International Nuclear Information System (INIS)

Susca, T.; Gaffin, S.R.; Dell'Osso, G.R.

2011-01-01

This paper attempts to evaluate the positive effects of vegetation with a multi-scale approach: an urban and a building scale. Monitoring the urban heat island in four areas of New York City, we have found an average of 2 deg. C difference of temperatures between the most and the least vegetated areas, ascribable to the substitution of vegetation with man-made building materials. At micro-scale, we have assessed the effect of surface albedo on climate through the use of a climatological model. Then, using the CO 2 equivalents as indicators of the impact on climate, we have compared the surface albedo, and the construction, replacement and use phase of a black, a white and a green roof. By our analyses, we found that both the white and the green roofs are less impactive than the black one; with the thermal resistance, the biological activity of plants and the surface albedo playing a crucial role. - Highlights: → The local morphology and the scarcity of vegetation in NYC core determines its UHI. → We introduce the evaluation of the effects of the surface albedo on climate change. → We use it to compare a black roof with a white and a green one. → Surface albedo has a crucial role in the evaluation of the environmental loads of the roofs. → Vegetation has positive effects on both the urban and the building scale. - Vegetation has positive effects both on an urban scale, mitigating the urban heat island effect; and on a building scale, where albedo, thermal insulation and biological activity of plants play a crucial role.

Use of GLOBE Observations to Derive a Landsat 8 Split Window Algorithm for Urban Heat Island

Science.gov (United States)

Fagerstrom, L.; Czajkowski, K. P.

2017-12-01

Surface temperature has been studied to investigate the warming of urban climates, also known as urban heat islands, which can impact urban planning, public health, pollution levels, and energy consumption. However, the full potential of remotely sensed images is limited when analyzing land surface temperature due to the daunting task of correcting for atmospheric effects. Landsat 8 has two thermal infrared sensors. With two bands in the infrared region, a split window algorithm (SWA), can be applied to correct for atmospheric effects. This project used in situ surface temperature measurements from NASA's ground observation program, the Global Learning and Observations to Benefit the Environment (GLOBE), to derive the correcting coefficients for use in the SWA. The GLOBE database provided land surface temperature data that coincided with Landsat 8 overpasses. The land surface temperature derived from Landsat 8 SWA can be used to analyze for urban heat island effect.

Satellite and Ground-Based Sensors for the Urban Heat Island Analysis in the City of Rome

Directory of Open Access Journals (Sweden)

Roberto Fabrizi

2010-05-01

Full Text Available In this work, the trend of the Urban Heat Island (UHI of Rome is analyzed by both ground-based weather stations and a satellite-based infrared sensor. First, we have developed a suitable algorithm employing satellite brightness temperatures for the estimation of the air temperature belonging to the layer of air closest to the surface. UHI spatial characteristics have been assessed using air temperatures measured by both weather stations and brightness temperature maps from the Advanced Along Track Scanning Radiometer (AATSR on board ENVISAT polar-orbiting satellite. In total, 634 daytime and nighttime scenes taken between 2003 and 2006 have been processed. Analysis of the Canopy Layer Heat Island (CLHI during summer months reveals a mean growth in magnitude of 3–4 K during nighttime and a negative or almost zero CLHI intensity during daytime, confirmed by the weather stations.

A Danish Heat Atlas for Supply Strategies and Demand Side Management

DEFF Research Database (Denmark)

Möller, Bernd

The expansion of district heating, the assessment of the impact of heat supply strategies, as well as the analysis of significant heat demand savings require sound decision support at high detail. Data is needed to continuously quantify potentials and costs of measures in the end-use and supply...... heat demand and possible savings. The location of each building relative to heat supply technologies is mapped and used for the assessment of supply strategies by potentials, costs and environmental impact. Both elements can furthermore be used to balance investments in supply with investments...

Optimal Economic Operation of Islanded Microgrid by Using a Modified PSO Algorithm

Directory of Open Access Journals (Sweden)

Yiwei Ma

2015-01-01

Full Text Available An optimal economic operation method is presented to attain a joint-optimization of cost reduction and operation strategy for islanded microgrid, which includes renewable energy source, the diesel generator, and battery storage system. The optimization objective is to minimize the overall generating cost involving depreciation cost, operation cost, emission cost, and economic subsidy available for renewable energy source, while satisfying various equality and inequality constraints. A novel dynamic optimization process is proposed based on two different operation control modes where diesel generator or battery storage acts as the master unit to maintain the system frequency and voltage stability, and a modified particle swarm optimization algorithm is applied to get faster solution to the practical economic operation problem of islanded microgrid. With the example system of an actual islanded microgrid in Dongao Island, China, the proposed models, dynamic optimization strategy, and solution algorithm are verified and the influences of different operation strategies and optimization algorithms on the economic operation are discussed. The results achieved demonstrate the effectiveness and feasibility of the proposed method.

Application of hydrogen energy in the tourism development strategy of the croatian islands

Energy Technology Data Exchange (ETDEWEB)

Vujcic, R. [Brodosplit-Institute, Split (Croatia); Josopovic, Z. [Chroatian Chamber of Economy, County Chamber Split, Split (Croatia); Matejcic, F. [The County of Split and Dalmatia, Split (Croatia)

1998-07-01

Croatian islands represent the most valuable resources of Croatian tourism. The recently adopted Development Strategy of the Croatian Tourism Sector contains the basic terms of reference for the formulation of a quality island tourism development concept. For such a development program it is imperative to establish new, environmentally compatible power system suitable to ensure sufficient quantities of high quality power. One of the viable possibilities to ensure sufficient quantity of quality power is a hydrogen power system based on renewable energy sources (solar and/or wind energy). 9 refs.

Urban surface temperature behaviour and heat island effect in a tropical planned city

Science.gov (United States)

Ahmed, Adeb Qaid; Ossen, Dilshan Remaz; Jamei, Elmira; Manaf, Norhashima Abd; Said, Ismail; Ahmad, Mohd Hamdan

2015-02-01

Putrajaya is a model city planned with concepts of a "city in the garden" and an "intelligent city" in the tropics. This study presents the behaviour of the surface temperature and the heat island effect of Putrajaya. Findings show that heat island intensity is 2 °C on average at nighttime and negligible at daytime. But high surface temperature values were recorded at the main boulevard due to direct solar radiation incident, street orientation in the direction of northeast and southwest and low building height-to-street width ratio. Buildings facing each other had cooling effect on surfaces during the morning and evening hours; conversely, they had a warming effect at noon. Clustered trees along the street are effective in reducing the surface temperature compared to scattered and isolated trees. Surface temperature of built up areas was highest at noon, while walls and sidewalks facing northwest were hottest later in the day. Walls and sidewalks that face northwest were warmer than those that face southeast. The surface temperatures of the horizontal street surfaces and of vertical façades are at acceptable levels relative to the surface temperature of similar surfaces in mature cities in subtropical, temperate and Mediterranean climates.

Spatial distribution of urban heat island in Hangzhou and its mitigation countermeasures

DEFF Research Database (Denmark)

Wang, W.-W.; Li, G.-L.; Xue, J.

2009-01-01

of the evolution of urban landuse types, the changes of urban spatial pattern, the rationality of the urban land layout, and the emission of anthropogenic heat. Finally, in the perspective of urban planning, some mitigation countermeasures including the reasonable control of the expansion of urban landuse......, construction of the urban ecological open space, optimization of the layout of urban landuse, and planning for underlaying surface were put forward. This aims to provide a reference to work in improving the thermal environment of Hangzhou City.......Taking Hangzhou City in summer as a case, the thermal infrared remote sensing image (Landsat 5 TM) was used to extract and inverse the surface land cover types and surface temperature of Hangzhou City. The spatial distribution characteristics of urban heat island was analyzed in the city...

Reductions in labour capacity from heat stress under climate warming

Science.gov (United States)

Dunne, John P.; Stouffer, Ronald J.; John, Jasmin G.

2013-06-01

A fundamental aspect of greenhouse-gas-induced warming is a global-scale increase in absolute humidity. Under continued warming, this response has been shown to pose increasingly severe limitations on human activity in tropical and mid-latitudes during peak months of heat stress. One heat-stress metric with broad occupational health applications is wet-bulb globe temperature. We combine wet-bulb globe temperatures from global climate historical reanalysis and Earth System Model (ESM2M) projections with industrial and military guidelines for an acclimated individual's occupational capacity to safely perform sustained labour under environmental heat stress (labour capacity)--here defined as a global population-weighted metric temporally fixed at the 2010 distribution. We estimate that environmental heat stress has reduced labour capacity to 90% in peak months over the past few decades. ESM2M projects labour capacity reduction to 80% in peak months by 2050. Under the highest scenario considered (Representative Concentration Pathway 8.5), ESM2M projects labour capacity reduction to less than 40% by 2200 in peak months, with most tropical and mid-latitudes experiencing extreme climatological heat stress. Uncertainties and caveats associated with these projections include climate sensitivity, climate warming patterns, CO2 emissions, future population distributions, and technological and societal change.

ANALYSIS OF THE INTRA-CITY VARIATION OF URBAN HEAT ISLAND AND ITS RELATION TO LAND SURFACE/COVER PARAMETERS

Directory of Open Access Journals (Sweden)

D. Gerçek

2016-06-01

Full Text Available Along with urbanization, sealing of vegetated land and evaporation surfaces by impermeable materials, lead to changes in urban climate. This phenomenon is observed as temperatures several degrees higher in densely urbanized areas compared to the rural land at the urban fringe particularly at nights, so-called Urban Heat Island. Urban Heat Island (UHI effect is related with urban form, pattern and building materials so far as it is associated with meteorological conditions, air pollution, excess heat from cooling. UHI effect has negative influences on human health, as well as other environmental problems such as higher energy demand, air pollution, and water shortage. Urban Heat Island (UHI effect has long been studied by observations of air temperature from thermometers. However, with the advent and proliferation of remote sensing technology, synoptic coverage and better representations of spatial variation of surface temperature became possible. This has opened new avenues for the observation capabilities and research of UHIs. In this study, "UHI effect and its relation to factors that cause it" is explored for İzmit city which has been subject to excess urbanization and industrialization during the past decades. Spatial distribution and variation of UHI effect in İzmit is analysed using Landsat 8 and ASTER day & night images of 2015 summer. Surface temperature data derived from thermal bands of the images were analysed for UHI effect. Higher temperatures were classified into 4 grades of UHIs and mapped both for day and night. Inadequate urban form, pattern, density, high buildings and paved surfaces at the expanse of soil ground and vegetation cover are the main factors that cause microclimates giving rise to spatial variations in temperatures across cities. These factors quantified as land surface/cover parameters for the study include vegetation index (NDVI, imperviousness (NDISI, albedo, solar insolation, Sky View Factor (SVF, building

Analysis of the Intra-City Variation of Urban Heat Island and its Relation to Land Surface/cover Parameters

Science.gov (United States)

Gerçek, D.; Güven, İ. T.; Oktay, İ. Ç.

2016-06-01

Along with urbanization, sealing of vegetated land and evaporation surfaces by impermeable materials, lead to changes in urban climate. This phenomenon is observed as temperatures several degrees higher in densely urbanized areas compared to the rural land at the urban fringe particularly at nights, so-called Urban Heat Island. Urban Heat Island (UHI) effect is related with urban form, pattern and building materials so far as it is associated with meteorological conditions, air pollution, excess heat from cooling. UHI effect has negative influences on human health, as well as other environmental problems such as higher energy demand, air pollution, and water shortage. Urban Heat Island (UHI) effect has long been studied by observations of air temperature from thermometers. However, with the advent and proliferation of remote sensing technology, synoptic coverage and better representations of spatial variation of surface temperature became possible. This has opened new avenues for the observation capabilities and research of UHIs. In this study, "UHI effect and its relation to factors that cause it" is explored for İzmit city which has been subject to excess urbanization and industrialization during the past decades. Spatial distribution and variation of UHI effect in İzmit is analysed using Landsat 8 and ASTER day & night images of 2015 summer. Surface temperature data derived from thermal bands of the images were analysed for UHI effect. Higher temperatures were classified into 4 grades of UHIs and mapped both for day and night. Inadequate urban form, pattern, density, high buildings and paved surfaces at the expanse of soil ground and vegetation cover are the main factors that cause microclimates giving rise to spatial variations in temperatures across cities. These factors quantified as land surface/cover parameters for the study include vegetation index (NDVI), imperviousness (NDISI), albedo, solar insolation, Sky View Factor (SVF), building envelope

The Impact of Energy Consumption on the Surface Urban Heat Island in China’s 32 Major Cities

Directory of Open Access Journals (Sweden)

Weilin Liao

2017-03-01

Full Text Available Supported by the rapid economic development in the last few decades, China has become the largest energy consumer in the world. Alongside this, the effect of the anthropogenic heat released from energy consumption is increasingly apparent. We quantified the daytime and nighttime surface urban heat island intensity (SUHII for the 32 major cities in mainland China, using MODIS land surface temperature data from 2008 to 2012, and estimated the energy consumption intensity (ECI based on the correlation between energy consumption and the sum of nighttime lights. On this basis, the impact of energy consumption on the surface urban heat island in China’s 32 major cities was analyzed, by directly examining the relationship between SUHII and the urban-suburban difference in ECI. The results show that energy consumption has a significantly positive correlation with the nighttime SUHII, but no correlation with the daytime SUHII. It indicates that the cities with a larger urban-suburban difference in ECI have a far greater impact on SUHII during the nighttime. Therefore, the statistical analysis of the historical observation data in this study provides evidence for a long-held hypothesis that the anthropogenic heat released from energy consumption is an important contributor to the urban thermal environment.

Analytical approach for evaluating temperature field of thermal modified asphalt pavement and urban heat island effect

International Nuclear Information System (INIS)

Chen, Jiaqi; Wang, Hao; Zhu, Hongzhou

2017-01-01

Highlights: • Derive an analytical approach to predict temperature fields of multi-layered asphalt pavement based on Green’s function. • Analyze the effects of thermal modifications on heat output from pavement to near-surface environment. • Evaluate pavement solutions for reducing urban heat island (UHI) effect. - Abstract: This paper aims to present an analytical approach to predict temperature fields in asphalt pavement and evaluate the effects of thermal modification on near-surface environment for urban heat island (UHI) effect. The analytical solution of temperature fields in the multi-layered pavement structure was derived with the Green’s function method, using climatic factors including solar radiation, wind velocity, and air temperature as input parameters. The temperature solutions were validated with an outdoor field experiment. By using the proposed analytical solution, temperature fields in the pavement with different pavement surface albedo, thermal conductivity, and layer combinations were analyzed. Heat output from pavement surface to the near-surface environment was studied as an indicator of pavement contribution to UHI effect. The analysis results show that increasing pavement surface albedo could decrease pavement temperature at various depths, and increase heat output intensity in the daytime but decrease heat output intensity in the nighttime. Using reflective pavement to mitigate UHI may be effective for an open street but become ineffective for the street surrounded by high buildings. On the other hand, high-conductivity pavement could alleviate the UHI effect in the daytime for both the open street and the street surrounded by high buildings. Among different combinations of thermal-modified asphalt mixtures, the layer combination of high-conductivity surface course and base course could reduce the maximum heat output intensity and alleviate the UHI effect most.

Detailed Urban Heat Island Projections for Cities Worldwide: Dynamical Downscaling CMIP5 Global Climate Models

Directory of Open Access Journals (Sweden)

Dirk Lauwaet

2015-06-01

Full Text Available A new dynamical downscaling methodology to analyze the impact of global climate change on the local climate of cities worldwide is presented. The urban boundary layer climate model UrbClim is coupled to 11 global climate models contained in the Coupled Model Intercomparison Project 5 archive, conducting 20-year simulations for present (1986–2005 and future (2081–2100 climate conditions, considering the Representative Concentration Pathway 8.5 climate scenario. The evolution of the urban heat island of eight different cities, located on three continents, is quantified and assessed, with an unprecedented horizontal resolution of a few hundred meters. For all cities, urban and rural air temperatures are found to increase strongly, up to 7 °C. However, the urban heat island intensity in most cases increases only slightly, often even below the range of uncertainty. A potential explanation, focusing on the role of increased incoming longwave radiation, is put forth. Finally, an alternative method for generating urban climate projections is proposed, combining the ensemble temperature change statistics and the results of the present-day urban climate.

Secondary Restoration Control of Islanded Microgrids With Decentralized Event-triggered Strategy

DEFF Research Database (Denmark)

Guerrero, Josep M.; Chen, Meng; Xiao, Xiangning

2018-01-01

in the feedback control laws, the proposed control strategies just require the communication between distributed secondary controllers at some particular instants while having frequency and voltage restoration function and accurate active power sharing. The stability and inter-event interval are also analyzed......Distributed cooperative control methods attract more and more attention in microgrid secondary control because they are more reliable and flexible. However, the traditional methods rely on the periodic communication, which is neither economic nor efficient due to its large communication burden...... in this paper. An islanded microgrid test system is built in PSCAD/EMTDC to validate the proposed control strategies. It shows that the proposed secondary control strategies based on event-triggered approach can highly reduce the inter-agent communication....

Detection of urban heat island in Ankara, Turkey

International Nuclear Information System (INIS)

Cicek, I.; Dogan, U.

2006-01-01

Ankara is the second largest city in Turkey after Istanbul, and the rate of population increase and urbanization are quite high. In this study, the effects of urbanization on temperature variation due to urbanization in Ankara were investigated. The intensities of urban heat island (UHI) for long and short term were analyzed. Analysis of both long- and short-term data revealed that there is a significant increase in the intensity of UHI (AT(u-r)) in winter during the period analyzed. Analysis of data collected for period of October 2001-September 2002 shows that intensity of maximum UHI is in February. In this month, positive UHI was observed in 26 nights and on all these days wind speed was less than 0.5ms.1. UHI is positive in all seasons and frequency and intensity of UHI in winter are higher than in the other seasons. This characteristic makes Ankara different from other temperate latitude cities

Decentralized Coordinated Control Strategy of Islanded Microgrids

DEFF Research Database (Denmark)

Wu, Dan

as grid voltage/frequency regulation. In order to enhance the reliability of overall islanded Microgrid operation, basic functions of coordinated control which taking into account the state of charge (SoC) limitation and power availability of renewable energy sources is implemented in a distributed level...... control strategies in this thesis, in order to promote the decentralization of the overall system. Especially the consensus algorithm based secondary level is investigated in the thesis in order to simplify the communication configuration which only flood information through the neighboring units......Facing the challenges brought by the traditional large power system concerning the environmental and economic issues, along recent years distributed generation is considered as an alternative solution to provide clean energy in a local manner. In this context, Microgrid which performing as a local...

Dose reduction strategies for cardiac CT

International Nuclear Information System (INIS)

Midgley, S.M.; Einsiedel, P.; Langenberg, F.; Lui, E.

2010-01-01

Full text: Recent advances in CT technology have produced brighter X-ray sources. gantries capable of increased rotation speeds, faster scintil lation materials arranged into multiple rows of detectors, and associated advances in 3D reconstruction methods. These innovations have allowed multi-detector CT to be turned to the diagnosis of cardiac abnormalities and compliment traditional imaging techniques such as coronary angiography. This study examines the cardiac imaging solution offered by the Siemens Somatom Definition Dual Source 64 slice CT scanner. Our dose reduction strategies involve optimising the data acquisition protocols according to diagnostic task, patient size and heart rate. The relationship between scan parameters, image quality and patient dose is examined and verified against measurements with phantoms representing the standard size patient. The dose reduction strategies are reviewed with reference to survey results of patient dose. Some cases allow the insertion of shielding to protect radiosensitive organs, and results are presented to quantify the dose saving.

Long Island Transportation Plan to Manage Congestion: Framework for Developing and Evaluating Improvement Strategies

Science.gov (United States)

2002-04-20

The Long Island Transportation Plan to Manage Congestion (LITP 2000) will establish an integrated, multi-modal transportation program of cost-effective strategies to manage congestion and improve the movement of people and goods in Nassau and Suffolk...

The use of reflective and permeable pavements as a potential practice for heat island mitigation and stormwater management

International Nuclear Information System (INIS)

Li, H; Harvey, J T; Holland, T J; Kayhanian, M

2013-01-01

To help address the built environmental issues of both heat island and stormwater runoff, strategies that make pavements cooler and permeable have been investigated through measurements and modeling of a set of pavement test sections. The investigation included the hydraulic and thermal performance of the pavements. The permeability results showed that permeable interlocking concrete pavers have the highest permeability (or infiltration rate, ∼0.5 cm s −1 ). The two permeable asphalt pavements showed the lowest permeability, but still had an infiltration rate of ∼0.1 cm s −1 , which is adequate to drain rainwater without generating surface runoff during most typical rain events in central California. An increase in albedo can significantly reduce the daytime high surface temperature in summer. Permeable pavements under wet conditions could give lower surface temperatures than impermeable pavements. The cooling effect highly depends on the availability of moisture near the surface layer and the evaporation rate. The peak cooling effect of watering for the test sections was approximately 15–35 °C on the pavement surface temperature in the early afternoon during summer in central California. The evaporative cooling effect on the pavement surface temperature at 4:00 pm on the third day (25 h after watering) was still 2–7 °C lower compared to that on the second day, without considering the higher air temperature on the third day. A separate and related simulation study performed by UCPRC showed that full depth permeable pavements, if designed properly, can carry both light-duty traffic and certain heavy-duty vehicles while retaining the runoff volume captured from an average California storm event. These preliminarily results indicated the technical feasibility of combined reflective and permeable pavements for addressing the built environment issues related to both heat island mitigation and stormwater runoff management. (letter)

Water conservation benefits of urban heat mitigation: can cooling strategies reduce water consumption in California?

Science.gov (United States)

Vahmani, P.; Jones, A. D.

2017-12-01

Urban areas are at the forefront of climate mitigation and adaptation efforts given their high concentration of people, industry, and infrastructure. Many cities globally are seeking strategies to counter the consequences of both a hotter and drier climate. While urban heat mitigation strategies have been shown to have beneficial effects on health, energy consumption, and greenhouse gas emissions, their implications for water conservation have not been widely examined. Here we show that broad implementation of cool roofs, an urban heat mitigation strategy, not only results in significant cooling of air temperature, but also meaningfully decreases outdoor water consumption by reducing evaporative and irrigation water demands. Based on a suite of satellite-supported, multiyear regional climate simulations, we find that cool roof adoption has the potential to reduce outdoor water consumption across the major metropolitan areas in California by up to 9%. Irrigation water savings per capita, induced by cool roofs, range from 1.8 to 15.4 gallons per day across 18 counties examined. Total water savings in Los Angeles county alone is about 83 million gallons per day. While this effect is robust across the 15 years examined (2001-2015), including both drought and non-drought years, we find that cool roofs are most effective during the hottest days of the year, indicating that they could play an even greater role in reducing outdoor water use in a hotter future climate. We further show that this synergistic relationship between heat mitigation and water conservation is asymmetrical - policies that encourage direct reductions in irrigation water use can lead to substantial regional warming, potentially conflicting with heat mitigation efforts designed to counter the effects of the projected warming climate.

Gender and poverty reduction strategy processes in Latin America

OpenAIRE

Dijkstra, Geske

2007-01-01

textabstractIn 1999, countries that wished to qualify for the Enhanced Initiative for the Heavily Indebted Poor Countries (HIPC initiative) had to elaborate Poverty Reduction Strategy Papers (PRSP) and had to do so with participation of civil society. Since then, the elaboration and subsequent implementation of PRSs (Poverty Reduction Strategies)have been seen as a tool for the international donor community to guarantee that not only debt relief, but also aid in general would be spent well. T...

Per-pack price reductions available from different cigarette purchasing strategies: United States, 2009-2010.

Science.gov (United States)

Pesko, Michael F; Xu, Xin; Tynan, Michael A; Gerzoff, Robert B; Malarcher, Ann M; Pechacek, Terry F

2014-06-01

Following cigarette excise tax increases, smokers may use cigarette price minimization strategies to continue their usual cigarette consumption rather than reducing consumption or quitting. This reduces the public health benefits of the tax increase. This paper estimates the price reductions for a wide-range of strategies, compensating for overlapping strategies. We performed regression analysis on the 2009-2010 National Adult Tobacco Survey (N=13,394) to explore price reductions that smokers in the United States obtained from purchasing cigarettes. We examined five cigarette price minimization strategies: 1) purchasing discount brand cigarettes, 2) using price promotions, 3) purchasing cartons, 4) purchasing on Indian reservations, and 5) purchasing online. Price reductions from these strategies were estimated jointly to compensate for overlapping strategies. Each strategy provided price reductions between 26 and 99cents per pack. Combined price reductions were possible. Additionally, price promotions were used with regular brands to obtain larger price reductions than when price promotions were used with generic brands. Smokers can realize large price reductions from price minimization strategies, and there are many strategies available. Policymakers and public health officials should be aware of the extent that these strategies can reduce cigarette prices. Published by Elsevier Inc.

Linking potential heat source and sink to urban heat island: Heterogeneous effects of landscape pattern on land surface temperature.

Science.gov (United States)

Li, Weifeng; Cao, Qiwen; Lang, Kun; Wu, Jiansheng

2017-05-15

Rapid urbanization has significantly contributed to the development of urban heat island (UHI). Regulating landscape composition and configuration would help mitigate the UHI in megacities. Taking Shenzhen, China, as a case study area, we defined heat source and heat sink and identified strong and weak sources as well as strong and weak sinks according to the natural and socioeconomic factors influencing land surface temperature (LST). Thus, the potential thermal contributions of heat source and heat sink patches were differentiated. Then, the heterogeneous effects of landscape pattern on LST were examined by using semiparametric geographically weighted regression (SGWR) models. The results showed that landscape composition has more significant effects on thermal environment than configuration. For a strong source, the percentage of patches has a positive impact on LST. Additionally, when mosaicked with some heat sink, even a small improvement in the degree of dispersion of a strong source helps to alleviate UHI. For a weak source, the percentage and density of patches have positive impacts on LST. For a strong sink, the percentage, density, and degree of aggregation of patches have negative impacts on LST. The effects of edge density and patch shape complexity vary spatially with the fragmentation of a strong sink. Similarly, the impacts of a weak sink are mainly exerted via the characteristics of percent, density, and shape complexity of patches. Copyright © 2017 Elsevier B.V. All rights reserved.

A response for substance and harm reduction in Pacific Island countries and territories.

Science.gov (United States)

Power, Robert; Schmich, Lucina; Nosa, Vili

2015-10-16

The Pacific is characterised as a region for the purposes of many international interventions and assistance programmes. Representatives of Pacific States participate in regional fora to build a strategic and unified approach to development. Regionally, bilateral trade agreements impact upon strategies to regulate alcohol imports. Policing and customs initiatives are increasingly supporting prevention of illicit drug production and trafficking, and model laws have been proposed to achieve consistency in enforcement. The aim of this commentary is to provide a response for policies using the case of alcohol and other drug research in the Pacific Islands Countries Territories. This commentary undertook a review of the current literature for regional developments for alcohol and other drug use in the Pacific Island Countries Territories region. A total of 14 articles were used in this article. The publication date for the articles used in this review ranged from 1997 to 2011. The findings of the review found that there should be a co-ordinated approach for adopting alcohol and other drug approaches. Furthermore, there should be a co-ordinated regional response with the inclusion of targeted domestic programming that will meet the needs for the Pacific Island countries and territories. Countries in the Pacific Island territories are characterised by varying degrees of political stability. Without stable government and democratic process, it is likely to remain difficult to develop consistent and effective legislation and policy for implementation of successful alcohol and other drug programmes. We found that there is a lack of robust and current data for alcohol and other drugs in Pacific Island countries and territories. Further research funding is needed to build the limited knowledge of alcohol and other drug substance use.

Efficiency potentials of heat pumps with combined heat and power. For maximum reduction of CO2 emissions and for electricity generation from fossil fuels with CO2 reduction in Switzerland

International Nuclear Information System (INIS)

Rognon, F.

2005-06-01

This comprehensive report for the Swiss Federal Office of Energy (SFOE) takes a look at how the efficiency potential of heat pumps together with combined heat and power systems can help provide a maximum reduction of CO 2 emissions and provide electricity generation from fossil fuel in Switzerland together with reductions in CO 2 emissions. In Switzerland, approximately 80% of the low-temperature heat required for space-heating and for the heating-up of hot water is produced by burning combustibles. Around a million gas and oil boilers were in use in Switzerland in 2000, and these accounted for approximately half the country's 41.1 million tonnes of CO 2 emissions. The authors state that there is a more efficient solution with lower CO 2 emissions: the heat pump. With the enormous potential of our environment it would be possible to replace half the total number of boilers in use today with heat pumps. This would be equivalent to 90 PJ p.a. of useful heat, or 500,000 systems. The power source for heat pumps should come from the substitution of electric heating systems (electric resistor-based systems) and from the replacement of boilers. This should be done by using combined heat and power systems with full heat utilisation. This means, according to the authors, that the entire required power source can be provided without the need to construct new electricity production plants. The paper examines and discusses the theoretical, technical, market and realisable potentials

Strategi for CO2-reduktion i den individuelle varmeforsyning: Strategy for CO2 reduction in the individual heat supply

OpenAIRE

Schjerling, Tina Gliese

2008-01-01

The project is made in cooperation with Lolland municipality, which has set a series of ambitious goals in relation to reducing the CO2 emissions in the municipality. One of the challenges faced by the municipality in this connection is to achieve a cleaner heat supply. The collective heat supply is almost 100% CO2-neutral, as the district heating plants primarily use CO2-neutral fuel. However, there are a great number of households outside the collective heat supply, which are heated by mean...

Energy access and security strategies in Small Island Developing States

International Nuclear Information System (INIS)

Wolf, Franziska; Surroop, Dinesh; Singh, Anirudh; Leal, Walter

2016-01-01

Small Islands Developing States (SIDS) are isolated and surrounded by ocean. The generation and use of energy resources are two very important aspects for the development of SIDS. Unfortunately, most of SIDS do not use their potential in respect of energy resources, and they as a result have to depend on the import of fossil fuels in order to meet their energy needs. This increases the overall vulnerability of SIDS as they have to depend on the rising or fluctuating fossil fuels prices. Some SIDS, especially in the geographically dispersed Pacific region, do not have proper access to energy whereas other SIDS struggle more with energy security issue. At the same time, SIDS are most vulnerable to the impacts and effects of climate change, as they are among the ones to be most severely affected in case of natural calamities and sea-level rise. Drawing on experiences from Fiji and Mauritius, this paper explains core elements related to energy access and security in SIDS, contextualizes and discusses barriers and list some of the strategies that may be used to ensure access to and a continuous supply of energy in SIDS. A situational analysis of two SIDS outlines their current energy situation and compares their energy policies to globally accepted criteria for SIDS policies as well as with each other. It is claimed that the diverging energy performances of Fiji and Mauritius cannot be explained by policies differences. The reasons for the varying energy performances may therefore lie in the administrative and institutional mechanisms used by the two countries in implementing their energy policies. Finally, to enable SIDS to reduce their overall vulnerability and become truly sustainable islands, it is recommended to undertake careful assessments of the particular local contexts under which island energy regimes operate. - Highlights: • Core elements related to energy access/security in SIDS, barriers and strategies. • Situational analysis of two SIDS: Fiji and

Impacts of city-block-scale countermeasures against urban heat-island phenomena upon a building's energy-consumption for air-conditioning

Energy Technology Data Exchange (ETDEWEB)

Kikegawa, Yukihiro [Department of Environmental Systems, Meisei University, 2-1-1 Hodokubo, Hino-shi, Tokyo 191-8506 (Japan); Genchi, Yutaka [Research Center for Life Cycle Assessment, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Kondo, Hiroaki [Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Hanaki, Keisuke [Department of Urban Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2006-06-15

This study quantifies the possible impacts of urban heat-island countermeasures upon buildings' energy use during summer in Tokyo metropolis. Considering the dependency of the buildings air temperature upon the local urban canopy structure, Tokyo urban canopies were classified in the city-block-scale using the sky-view factor (svf). Then, a multi-scale model system describing the interaction between buildings' energy use and urban meteorological conditions was applied to each classified canopy. In terms of urban warming alleviation and cooling energy saving, simulations suggested that the reduction in the air-conditioning anthropogenic heat could be the most effective measure in office buildings' canopies, and that vegetative fraction increase on the side walls of buildings in residential canopies. Both measures indicated daily and spatially averaged decreases in near-ground summer air temperature of 0.2-1.2{sup o}C. The simulations also suggested these temperature decreases could result in the buildings' cooling energy-savings of 4-40%, indicating remarkable savings in residential canopies. These temperature drops and energy savings tended to increase with the decrease of the svf of urban canopies. (author)

Effects of anthropogenic heat due to air-conditioning systems on an extreme high temperature event in Hong Kong

Science.gov (United States)

Wang, Y.; Li, Y.; Di Sabatino, S.; Martilli, A.; Chan, P. W.

2018-03-01

Anthropogenic heat flux is the heat generated by human activities in the urban canopy layer, which is considered the main contributor to the urban heat island (UHI). The UHI can in turn increase the use and energy consumption of air-conditioning systems. In this study, two effective methods for water-cooling air-conditioning systems in non-domestic areas, including the direct cooling system and central piped cooling towers (CPCTs), are physically based, parameterized, and implemented in a weather research and forecasting model at the city scale of Hong Kong. An extreme high temperature event (June 23-28, 2016) in the urban areas was examined, and we assessed the effects on the surface thermal environment, the interaction of sea-land breeze circulation and urban heat island circulation, boundary layer dynamics, and a possible reduction of energy consumption. The results showed that both water-cooled air-conditioning systems could reduce the 2 m air temperature by around 0.5 °C-0.8 °C during the daytime, and around 1.5 °C around 7:00-8:00 pm when the planetary boundary layer (PBL) height was confined to a few hundred meters. The CPCT contributed around 80%-90% latent heat flux and significantly increased the water vapor mixing ratio in the atmosphere by around 0.29 g kg-1 on average. The implementation of the two alternative air-conditioning systems could modify the heat and momentum of turbulence, which inhibited the evolution of the PBL height (a reduction of 100-150 m), reduced the vertical mixing, presented lower horizontal wind speed and buoyant production of turbulent kinetic energy, and reduced the strength of sea breeze and UHI circulation, which in turn affected the removal of air pollutants. Moreover, the two alternative air-conditioning systems could significantly reduce the energy consumption by around 30% during extreme high temperature events. The results of this study suggest potential UHI mitigation strategies and can be extended to

Correlation analysis of the urban heat island effect and the spatial and temporal distribution of atmospheric particulates using TM images in Beijing

International Nuclear Information System (INIS)

Xu, L.Y.; Xie, X.D.; Li, S.

2013-01-01

This study combines the methods of observation statistics and remote sensing retrieval, using remote sensing information including the urban heat island (UHI) intensity index, the normalized difference vegetation index (NDVI), the normalized difference water index (NDWI), and the difference vegetation index (DVI) to analyze the correlation between the urban heat island effect and the spatial and temporal concentration distributions of atmospheric particulates in Beijing. The analysis establishes (1) a direct correlation between UHI and DVI; (2) an indirect correlation among UHI, NDWI and DVI; and (3) an indirect correlation among UHI, NDVI, and DVI. The results proved the existence of three correlation types with regional and seasonal effects and revealed an interesting correlation between UHI and DVI, that is, if UHI is below 0.1, then DVI increases with the increase in UHI, and vice versa. Also, DVI changes more with UHI in the two middle zones of Beijing. -- Highlights: •We analyze the correlation from the spatial and temporal views. •We present correlation analyses among UHI, NDWI, NDVI, and DVI from three perspectives. •Three correlations are proven to exist with regional and seasonal effects. •If UHI is below 0.1, then DVI increases with the increase in UHI, and vice versa. •The DVI changes more with UHI in the two middle zones of Beijing. -- Generally, if UHI is below 0.1 in the weak heat island or green island range, then DVI increases with the increase in UHI, and vice versa

Ontario's Poverty Reduction Strategy: A Critical Discourse Analysis.

Science.gov (United States)

Benbow, Sarah; Gorlick, Carolyne; Forchuk, Cheryl; Ward-Griffin, Catherine; Berman, Helene

2016-01-01

This article overviews the second phase of a two-phase study which examined experiences of health and social exclusion among mothers experiencing homelessness in Ontario, Canada. A critical discourse analysis was employed to analyze the policy document, Realizing Our Potential: Ontario's Poverty Reduction Strategy, 2014-2019. In nursing, analysis of policy is an emerging form of scholarship, one that draws attention to the macro levels influencing health and health promotion, such as the social determinants of health, and the policies that impact them. The clear neo-liberal underpinnings, within the strategy, with a focus on productivity and labor market participation leave little room for an understanding of poverty reduction from a human rights perspective. Further, gender-neutrality rendered the poverty experienced by women, and mothers, invisible. Notably, there were a lack of deadlines, target dates, and thorough action and evaluation plans. Such absence troubles whether poverty reduction is truly a priority for the government, and society as a whole.

Fully-distributed Load Frequency Control Strategy in an Islanded Microgrid Considering Plug-In Electric Vehicles

Directory of Open Access Journals (Sweden)

Xiao Qi

2018-06-01

Full Text Available With large-scale integration of electric vehicles, this paper investigates the load frequency control problem in an islanded microgrid with plug-in electric vehicles (PEVs, which can be regarded as mobile battery energy storages to provide a valuable contribution to frequency regulation. A novel fully-distributed control strategy is proposed to achieve fast frequency regulation of islanded microgrids and effective coordination control of distributed energy sources. Firstly, distributed control based on an improved linear active disturbance rejection algorithm is realized through a multi-agent system, and it greatly enhances the anti-disturbance capability of the microgrid. Then, in order to guarantee the effectiveness of PEVs in frequency regulation, PEVs are controlled following the controllable power rate (CPR calculated from the consensus-based multi-agent system. Furthermore, the system control construction in this paper is well designed to avoid the negative effects caused by system communication time delay. Finally, numerical simulations under different disturbances are carried out to demonstrate the effectiveness of the proposed control strategy in comparison with other previous control strategies.

Quality and sensitivity of high-resolution numerical simulation of urban heat islands

Science.gov (United States)

Li, Dan; Bou-Zeid, Elie

2014-05-01

High-resolution numerical simulations of the urban heat island (UHI) effect with the widely-used Weather Research and Forecasting (WRF) model are assessed. Both the sensitivity of the results to the simulation setup, and the quality of the simulated fields as representations of the real world, are investigated. Results indicate that the WRF-simulated surface temperatures are more sensitive to the planetary boundary layer (PBL) scheme choice during nighttime, and more sensitive to the surface thermal roughness length parameterization during daytime. The urban surface temperatures simulated by WRF are also highly sensitive to the urban canopy model (UCM) used. The implementation in this study of an improved UCM (the Princeton UCM or PUCM) that allows the simulation of heterogeneous urban facets and of key hydrological processes, together with the so-called CZ09 parameterization for the thermal roughness length, significantly reduce the bias (Changing UCMs and PBL schemes does not alter the performance of WRF in reproducing bulk boundary layer temperature profiles significantly. The results illustrate the wide range of urban environmental conditions that various configurations of WRF can produce, and the significant biases that should be assessed before inferences are made based on WRF outputs. The optimal set-up of WRF-PUCM developed in this paper also paves the way for a confident exploration of the city-scale impacts of UHI mitigation strategies in the companion paper (Li et al 2014).

Conflicting strategies towards sustainable heating at an urban junction of heat infrastructure and building standards

International Nuclear Information System (INIS)

Späth, Philipp; Rohracher, Harald

2015-01-01

Approaches to ‘sustainability transitions’ stress the possibility of aligning actors around a shared vision of the future, e.g. at the scale of a city. Empirical accounts reveal how difficult such coordination often is due to contradictory views involved. How can we better understand related processes of searching and negotiation? What does this mean for the organization of decision making processes regarding long-term infrastructural change? We analyze a conflict which erupted in Freiburg, Germany when two strategies of reducing environmental impacts of space heating were to be applied in the Vauban ‘model district’: A) Efficient co-generation of heat and power (CHP) combined with district heating systems (DHS), and B) Reducing heat demand by low-energy designs and ambitious energy standards (‘passive house standard’). In order to understand the politics of infrastructure development, we unravel 1) enabling factors and driving forces of the conflict, 2) normative content of opposing viewpoints, 3) resources tapped into for settling the disagreement, and 4) the institutional setup of such decision making about energy policy priorities in the municipality. We reflect on implications of such a perspective on how policies and how governance arrangements should ideally be shaped and take a brief outlook on further research needed. - Highlights: • Foregrounds likeliness of conflicts over strategies within sustainability transitions. • District heating systems can be incommensurate with low energy building standards. • Studies one such conflict in an urban context (Freiburg, Germany) in depth. • Processes of urban planning can reveal frictions within and between infrastructures. • Can such junctions as opportunities for re-negotiation of strategies be anticipated?

Development of pollution reduction strategies for Mexico City: Estimating cost and ozone reduction effectiveness

International Nuclear Information System (INIS)

Thayer, G.R.; Hardie, R.W.; Barrera-Roldan, A.

1993-01-01

This reports on the collection and preparation of data (costs and air quality improvement) for the strategic evaluation portion of the Mexico City Air Quality Research Initiative (MARI). Reports written for the Mexico City government by various international organizations were used to identify proposed options along with estimates of cost and emission reductions. Information from appropriate options identified by SCAQMD for Southem California were also used in the analysis. A linear optimization method was used to select a group of options or a strategy to be evaluated by decision analysis. However, the reduction of ozone levels is not a linear function of the reduction of hydrocarbon and NO x emissions. Therefore, a more detailed analysis was required for ozone. An equation for a plane on an isopleth calculated with a trajectory model was obtained using two endpoints that bracket the expected total ozone precursor reductions plus the starting concentrations for hydrocarbons and NO x . The relationship between ozone levels and the hydrocarbon and NO x concentrations was assumed to lie on this plane. This relationship was used in the linear optimization program to select the options comprising a strategy

CFD prediction of heat island formation on growing Asian cities. Effect of urbanization in Shanghai; Kyodaikasuru Asia no toshi ni okeru heat island keisei ni kansuru CFD yosoku. Shanghai no toshika ga oyobosu eikyo ni kansuru kento

Energy Technology Data Exchange (ETDEWEB)

Ojima, T.; Murakami, S. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Mitsumoto, K. [Waseda University, Tokyo (Japan). School of Science and Engineering

1997-10-01

Study is conducted of the effect of change in land use and increase in artificial exhaust heat on heat island formation in Shanghai. Concerning the land use distribution in Shanghai, a point sampling survey was conducted in the 1930s using topographic charts, when the area was broken down into building-occupied region, paddy field, bare ground, and waters. In the 1990s, thanks to data from satellites, high-density and low-density urban regions have added. Calculation for Shanghai is performed, based on the rate of increase in Tokyo`s population and data predicted for Shanghai`s population, on the assumption that Shanghai`s population in the 2050s will grow 2.3 times larger than it is in the 1990s. The prediction thus produced indicates that the urban area in Shanghai in the 2050s will be as large as that of the present-day Tokyo that covers a 50km zone. Heat island formation prediction for Shanghai is worked out using computational fluid dynamics (CFD)-aided simulation. According to the prediction, while the maximum temperature in the 1930s was 29.6degC or 4degC higher than in the suburbs, it is 33.2degC or 7.6deg higher in the 1990s, and will be 34.4degC or 8.6degC higher in the 2050s. 16 refs., 11 figs., 1 tab.

Large Reduction of Hot Spot Temperature in Graphene Electronic Devices with Heat-Spreading Hexagonal Boron Nitride.

Science.gov (United States)

Choi, David; Poudel, Nirakar; Park, Saungeun; Akinwande, Deji; Cronin, Stephen B; Watanabe, Kenji; Taniguchi, Takashi; Yao, Zhen; Shi, Li

2018-04-04

Scanning thermal microscopy measurements reveal a significant thermal benefit of including a high thermal conductivity hexagonal boron nitride (h-BN) heat-spreading layer between graphene and either a SiO 2 /Si substrate or a 100 μm thick Corning flexible Willow glass (WG) substrate. At the same power density, an 80 nm thick h-BN layer on the silicon substrate can yield a factor of 2.2 reduction of the hot spot temperature, whereas a 35 nm thick h-BN layer on the WG substrate is sufficient to obtain a factor of 4.1 reduction. The larger effect of the h-BN heat spreader on WG than on SiO 2 /Si is attributed to a smaller effective heat transfer coefficient per unit area for three-dimensional heat conduction into the thick, low-thermal conductivity WG substrate than for one-dimensional heat conduction through the thin oxide layer on silicon. Consequently, the h-BN lateral heat-spreading length is much larger on WG than on SiO 2 /Si, resulting in a larger degree of temperature reduction.

Urban Heat Islands (UHI) and the influence of city parks within the urban environment.

Science.gov (United States)

Garcia, W.; Shandas, V.; Voelkel, J.; Espinoza, D.

2016-12-01

Urban Heat Islands (UHI) and the influence of city parks within the urban environment.As cities grow outward and their populations increase the Urban Heat Island (UHI) phenomena becomes an ever more important topic to reducing environmental stressors. When UHI combines with human sensitivities such as pre-existing health conditions, and other vulnerabilities, finding an effective way to cool our cities is a matter of life and death. One way to cool an area is to introduce vegetation; which is abundant is in city parks. This study measures the cooling effect and temperature gradient of city parks; characterizing the relationship between the cooling effects within parks and surrounding neighborhoods. Past studies of the UHI are largely based on satellite images and, more recently, car traverses across that describe the ambient temperatures. The present project aims to understand the effects of parks on the UHI by asking two research questions: (1) how do the physical characteristics and designs of city parks impact the variation in ambient temperatures? And (2) what effect does the park have on cooling the surrounding neighborhoods? We address these questions by using a bicycle mounted with a temperature probe, and a series of geospatial analytics. The bicycle collects temperature data every one second, and the traverse intervals are an hour long to prevent normal fluctuations of daily temperature. Preliminary analysis shows that there is a temperature gradient within the parks (Figure 1). Further, the average temperature of the urban park could cool the surrounding area by upwards of 2°C, depending on the physical characteristics of then park and neighborhood. Our results suggest that the role of smaller parks and their design can reduce heat stress particularly among the vulnerable populations. These results can help urban planners make informed decisions when developing future city infrastructure.

The Urban Heat Island Impact in Consideration of Spatial Pattern of Urban Landscape and Structure

Science.gov (United States)

Kim, J.; Lee, D. K.; Jeong, W.; Sung, S.; Park, J.

2015-12-01

Preceding study has established a clear relationship between land surface temperature and area of land covers. However, only few studies have specifically examined the effects of spatial patterns of land covers and urban structure. To examine how much the local climate is affected by the spatial pattern in highly urbanized city, we investigated the correlation between land surface temperature and spatial patterns of land covers. In the analysis of correlation, we categorized urban structure to four different land uses: Apartment residential area, low rise residential area, industrial area and central business district. Through this study, we aims to examine the types of residential structure and land cover pattern for reducing urban heat island and sustainable development. Based on land surface temperature, we investigated the phenomenon of urban heat island through using the data of remote sensing. This study focused on Daegu in Korea. This city, one of the hottest city in Korea has basin form. We used high-resolution land cover data and land surface temperature by using Landsat8 satellite image to examine 100 randomly selected sample sites of 884.15km2 (1)In each land use, we quantified several landscape-levels and class-level landscape metrics for the sample study sites. (2)In addition, we measured the land surface temperature in 3 year hot summer seasons (July to September). Then, we investigated the pattern of land surface temperature for each land use through Ecognition package. (3)We deducted the Pearson correlation coefficients between land surface temperature and each landscape metrics. (4)We analyzed the variance among the four land uses. (5)Using linear regression, we determined land surface temperature model for each land use. (6)Through this analysis, we aims to examine the best pattern of land cover and artificial structure for reducing urban heat island effect in highly urbanized city. The results of linear regression showed that proportional land

Fuelwood production in Prince Edward Island

International Nuclear Information System (INIS)

McCallum, B.

1992-01-01

The most recent Prince Edward Island Fuelwood Survey occurred in 1990-91. Consumption of fuelwood rose again to 49% of Prince Edward Island's 43,170 households. Total residential fuelwood consumption was estimated to be 242,000 m 3 . The fuelwood industry makes an important contribution to the economy of Prince Edward Island. In the 1990-91 heating season, fuelwood valued at USD 9 million displaced approximately 43 million litres of domestic heating oil valued at USD 16.4 million. In addition, it is estimated that 70 cents of every dollar spent on fuelwood remains in the province and contributes spin-off benefits, whereas 90 cents of every dollar spent on heating oil is lost to the economy of Prince Edward Island. The percentage of people cutting their own fuelwood decreased from 52 in 1984-85 to only 23.4 in 1990-91. The governments of Canada and Prince Edward Island have implemented a series of Forest Resource Development Agreements (FRDAs) starting in 1983. The current 1988-1993 FRDA provides USD 24 million for research and incentives for reforestation and management of Prince Edward Island woodlots. It is expected that 3,800 Prince Edward Island woodlot owners will be participating in a woodlot management program by 1993. Silviculture treatments of hardwood stands include thinning, stand conversion (removal of lowgrade softwoods such as balsam fir in mainly hardwood stands), and shelterwood (strip) cutting, particularly in marginal stands. (9 refs.)

Daytime urban heat islands from Landsat ETM+ and Corine land cover data: An application to major cities in Greece

Energy Technology Data Exchange (ETDEWEB)

Stathopoulou, Marina; Cartalis, Constantinos [Remote Sensing and Image Processing Laboratory, Division of Applied Physics, Department of Physics, Building PHYS-5, University Campus, 157 84 Athens (Greece)

2007-03-15

Satellite images in the thermal infrared can be used for assessing the thermal urban environment as well as for defining heat islands in urban areas. In this study, the thermal environment of major cities in Greece (Athens, Thessaloniki, Patra, Volos and Heraklion) is examined using satellite images provided by the Landsat Enhanced Thematic Mapper (ETM+) sensor on board Landsat 7 satellite corresponding to the daytime and warm period when the surface urban heat island (SUHI) phenomenon is best observed. The spatial structure of the thermal urban environment is analyzed in each case study and the ''hottest'' surfaces within the urban settings are identified and related to the urban surface characteristics and land use. For the needs of the study, the Corine land cover (CLC) database for Greece is also used, in an effort to define more effectively the link between surface emissivities, land surface temperatures and urban surface characteristics. (author)

Global warming and its implication to emission reduction strategies for residential buildings

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaoming; Chen, Dong; Ren, Zhengen [CSIRO Climate Adaptation Flagship and CSIRO Ecosystem Sciences, Commonwealth Scientific and Industrial Research Organisation (CSIRO), P.O. Box 56, Graham Road, Highett, Victoria 3190 (Australia)

2011-04-15

Carbon emission reduction schemes by improving residential building energy performance are often developed and assessed upon the assumption of current or stationary climates. This study investigated the heating and cooling (H-C) energy requirements and corresponding carbon emissions of residential houses in different climatic conditions in relation to global warming. This included assessing and quantifying the efficacy of emission reduction schemes based on emission reduction capacity (ERC). ERC represents the percentage of projected carbon emission reduction under changing climate in a specific year compared to the expected reduction by a scheme at current or stationary climates. It is shown that in a heating-dominated region with a cold climate or temperate climate with cold winter, ERC is projected to increase (or the projected emission reduction is higher than the expected reduction under the emission reduction scheme) in the presence of global warming. In contrast, in a cooling-dominated region with a hot dry or hot humid climate or an H-C balanced temperate climate, ERC is projected to decline. This implies that emission reductions will be lower than those initially targeted by the emission reduction scheme without consideration of global warming. Additionally, to reflect the changing carbon emission over years due to climate change, the average emission reduction capacity (AERC) was also proposed for the assessment of reduction schemes. It was concluded that the design and assessment of carbon emission reduction schemes for residential buildings need to move beyond its assumptions of a current or stationary climate to take into account climate change impacts. (author)

Strategies for emission reduction from thermal power plants.

Science.gov (United States)

Prisyazhniuk, Vitaly A

2006-07-01

Major polluters of man's environment are thermal power stations (TPS) and power plants, which discharge into the atmosphere the basic product of carbon fuel combustion, CO2, which results in a build-up of the greenhouse effect and global warm-up of our planet's climate. This paper is intended to show that the way to attain environmental safety of the TPS and to abide by the decisions of the Kyoto Protocol lies in raising the efficiency of the heat power stations and reducing their fuel consumption by using nonconventional thermal cycles. Certain equations have been derived to define the quantitative interrelationship between the growth of efficiency of the TPS, decrease in fuel consumption and reduction of discharge of dust, fuel combustion gases, and heat into the environment. New ideas and new technological approaches that result in raising the efficiency of the TPS are briefly covered: magneto-hydrodynamic resonance, the Kalina cycle, and utilizing the ambient heat by using, as the working medium, low-boiling substances.

Effective Behaviour Management Strategies for Australian Aboriginal and Torres Strait Islander Students: A Literature Review

Science.gov (United States)

Llewellyn, Linda L.; Boon, Helen J.; Lewthwaite, Brian E.

2018-01-01

This paper reports findings from a systematic literature review conducted to identify effective behaviour management strategies which create a positive learning environment for Aboriginal and Torres Strait Islander students. The search criteria employed resulted in 103 documents which were analysed in response to this focus. Results identified…

Fouling reduction characteristics of a no-distributor-fluidized-bed heat exchanger for flue gas heat recovery

Energy Technology Data Exchange (ETDEWEB)

Jun, Y.D.; Lee, K.B.; Islam, S.Z.; Ko, S.B. [Kongju National University, Kong Ju (Republic of Korea). Dept. for Mechanical Engineering

2008-07-01

In conventional flue gas heat recovery systems, the fouling by fly ashes and the related problems such as corrosion and cleaning are known to be major drawbacks. To overcome these problems, a single-riser no-distributor-fluidized-bed heat exchanger is devised and studied. Fouling and cleaning tests are performed for a uniquely designed fluidized bed-type heat exchanger to demonstrate the effect of particles on the fouling reduction and heat transfer enhancement. The tested heat exchanger model (1 m high and 54 mm internal diameter) is a gas-to-water type and composed of a main vertical tube and four auxiliary tubes through which particles circulate and transfer heat. Through the present study, the fouling on the heat transfer surface could successfully be simulated by controlling air-to-fuel ratios rather than introducing particles through an external feeder, which produced soft deposit layers with 1 to 1.5 mm thickness on the inside pipe wall. Flue gas temperature at the inlet of heat exchanger was maintained at 450{sup o}C at the gas volume rate of 0.738 to 0.768 CMM (0.0123 to 0.0128 m{sup 3}/sec). From the analyses of the measured data, heat transfer performances of the heat exchanger before and after fouling and with and without particles were evaluated. Results showed that soft deposits were easily removed by introducing glass bead particles, and also heat transfer performance increased two times by the particle circulation. In addition, it was found that this type of heat exchanger had high potential to recover heat of waste gases from furnaces, boilers, and incinerators effectively and to reduce fouling related problems.

Per-pack price reductions available from different cigarette purchasing strategies: United States, 2009–2010☆

Science.gov (United States)

Pesko, Michael F.; Xu, Xin; Tynan, Michael A.; Gerzoff, Robert B.; Malarcher, Ann M.; Pechacek, Terry F.

2015-01-01

Objective Following cigarette excise tax increases, smokers may use cigarette price minimization strategies to continue their usual cigarette consumption rather than reducing consumption or quitting. This reduces the public health benefits of the tax increase. This paper estimates the price reductions for a wide-range of strategies, compensating for overlapping strategies. Method We performed regression analysis on the 2009–2010 National Adult Tobacco Survey (N = 13,394) to explore price reductions that smokers in the United States obtained from purchasing cigarettes. We examined five cigarette price minimization strategies: 1) purchasing discount brand cigarettes, 2) using price promotions, 3) purchasing cartons, 4) purchasing on Indian reservations, and 5) purchasing online. Price reductions from these strategies were estimated jointly to compensate for overlapping strategies. Results Each strategy provided price reductions between 26 and 99 cents per pack. Combined price reductions were possible. Additionally, price promotions were used with regular brands to obtain larger price reductions than when price promotions were used with generic brands. Conclusion Smokers can realize large price reductions from price minimization strategies, and there are many strategies available. Policymakers and public health officials should be aware of the extent that these strategies can reduce cigarette prices. PMID:24594102

Urban heat island and bioclimatological conditions in a hot-humid tropical city: the example of Akure, Nigeria

Directory of Open Access Journals (Sweden)

Balogun, Ifeoluwa A.

2014-09-01

Full Text Available The impact of weather on human health has become an issue of increased significance in recent times, considering the increasing rate of urbanisation and the much associated heat island phenomenon. This study examines the urbanisation influence on human bioclimatic conditions in Akure, a medium sized hot-humid tropical city in Nigeria, utilising data from measurements at urban and rural sites in the city. Differences in the diurnal, monthly and seasonal variation of human bioclimatic characteristics between both environments were evaluated and tested for statistical significance. Higher frequencies of high temperatures observed in the city centre suggest a significant heat stress and health risk in this hot-humid city.

Green Space and Deaths Attributable to the Urban Heat Island Effect in Ho Chi Minh City.

Science.gov (United States)

Dang, Tran Ngoc; Van, Doan Quang; Kusaka, Hiroyuki; Seposo, Xerxes T; Honda, Yasushi

2018-04-01

To quantify heat-related deaths in Ho Chi Minh City, Vietnam, caused by the urban heat island (UHI) and explore factors that may alleviate the impact of UHIs. We estimated district-specific meteorological conditions from 2010 to 2013 using the dynamic downscaling model and calculated the attributable fraction and number of mortalities resulting from the total, extreme, and mild heat in each district. The difference in attributable fraction of total heat between the central and outer districts was classified as the attributable fraction resulting from the UHI. The association among attributable fraction, attributable number with a green space, population density, and budget revenue of each district was then explored. The temperature-mortality relationship between the central and outer areas was almost identical. The attributable fraction resulting from the UHI was 0.42%, which was contributed by the difference in temperature distribution between the 2 areas. Every 1-square-kilometer increase in green space per 1000 people can prevent 7.4 deaths caused by heat. Green space can alleviate the impacts of UHIs, although future studies conducting a heath economic evaluation of tree planting are warranted.

Developing the "Compendium of Strategies to Reduce Teacher Turnover in the Northeast and Islands Region." A Companion to the Database. Issues & Answers. REL 2008-No. 052

Science.gov (United States)

Ellis, Pamela; Grogan, Marian; Levy, Abigail Jurist; Tucker-Seeley, Kevon

2008-01-01

This report provides state-, regional-, and district-level decisionmakers in the Northeast and Islands Region with a description of the "Compendium of Strategies to Reduce Teacher Turnover in the Northeast and Islands Region," a searchable database of selected profiles of retention strategies implemented in Connecticut, Maine,…

Land Use and Land Cover Change, Urban Heat Island Phenomenon, and Health Implications: A Remote Sensing Approach

Science.gov (United States)

Lo, C. P.; Quattrochi, Dale A.

2003-01-01

Land use and land cover maps of Atlanta Metropolitan Area in Georgia were produced from Landsat MSS and TM images for 1973,1979,1983,1987,1992, and 1997, spanning a period of 25 years. Dramatic changes in land use and land cover have occurred with loss of forest and cropland to urban use. In particular, low-density urban use, which includes largely residential use, has increased by over 119% between 1973 and 1997. These land use and land cover changes have drastically altered the land surface characteristics. An analysis of Landsat images revealed an increase in surface temperature and a decline in NDVI from 1973 to 1997. These changes have forced the development of a significant urban heat island effect and an increase in ground level ozone production to such an extent, that Atlanta has violated EPA's ozone level standard in recent years. The urban heat island initiated precipitation events that were identified between 1996 and 2000 tended to occur near high-density urban areas but outside the I-285 loop that traverses around the Central Business District, i.e. not in the inner city area, but some in close proximity to the highways. The health implications were investigated by comparing the spatial patterns of volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions, the two ingredients that form ozone by reacting with sunlight, with those of rates of cardiovascular and chronic lower respiratory diseases. A clear core-periphery pattern was revealed for both VOC and NOx emissions, but the spatial pattern was more random in the cases of rates of cardiovascular and chronic lower respiratory diseases. Clearly, factors other than ozone pollution were involved in explaining the rates of these diseases. Further research is therefore needed to understand the health geography and its relationship to land use and land cover change as well as urban heat island effect. This paper illustrates the usefulness of a remote sensing approach for this purpose.

Cigarette price minimization strategies in the United States: price reductions and responsiveness to excise taxes.

Science.gov (United States)

Pesko, Michael F; Licht, Andrea S; Kruger, Judy M

2013-11-01

Because cigarette price minimization strategies can provide substantial price reductions for individuals continuing their usual smoking behaviors following federal and state cigarette excise tax increases, we examined independent price reductions compensating for overlapping strategies. The possible availability of larger independent price reduction opportunities in states with higher cigarette excise taxes is explored. Regression analysis used the 2006-2007 Tobacco Use Supplement of the Current Population Survey (N = 26,826) to explore national and state-level independent price reductions that smokers obtained from purchasing cigarettes (a) by the carton, (b) in a state with a lower average after-tax cigarette price than in the state of residence, and (c) in "some other way," including online or in another country. Price reductions from these strategies are estimated jointly to compensate for known overlapping strategies. Each strategy reduced the price of cigarettes by 64-94 cents per pack. These price reductions are 9%-22% lower than conventionally estimated results not compensating for overlapping strategies. Price reductions vary substantially by state. Following cigarette excise tax increases, the price reduction available from purchasing cigarettes by cartons increased. Additionally, the price reduction from purchasing cigarettes in a state with a lower average after-tax cigarette price is positively associated with state cigarette excise tax rates and border state cigarette excise tax rate differentials. Findings from this large, nationally representative study of cigarette smokers suggest that price reductions are larger in states with higher cigarette excise taxes, and increase as cigarette excise taxes rise.

District heating and cogeneration in the EU-28: Current situation, potential and proposed energy strategy for its generalisation

Directory of Open Access Journals (Sweden)

Enrique Rosales-Asensio

2016-10-01

Full Text Available Yearly, EU-28 conventional thermal generating plants reject a greater amount of energy than what ultimately is utilised by residential and commercial loads for heating and hot water. If this waste heat were to be used through district heating networks, given a previous energy valorisation, there would be a noticeable decrease in imported fossil fuels for heating. As a consequence, benefits in the form of an energy efficiency increase, an energy security improvement, and a minimisation of emitted greenhouse gases would occur. Given that it is not expected for heat demand to decrease significantly in the medium term, district heating networks show the greatest potential for the development of cogeneration. However, to make this happen, some barriers that are far from being technological but are mostly institutional and financial need to be removed. The purpose of this review is to provide information on the potential of using waste heat from conventional thermal power plants (subsequently converted into cogeneration plants in district heating networks located in the EU-28. For this, a preliminary assessment is conducted in order to show an estimate of the cost of adopting an energy strategy in which district heating networks are a major player of the energy mix. From this assessment, it is possible to see that even though the energy strategy proposed in this paper, which is based on a dramatic increase in the joint use of district heating networks and cogeneration, is capital-intensive and would require an annual investment of roughly 300 billion euros, its adoption would result in a reduction of yearly fuel expenses in the order of 100 billion euros and a shortening of about 15% of the total final energy consumption, which makes it of paramount interest as an enabler of the legal basis of the “Secure, Clean and Efficient Energy” future enacted by the EU-28 Horizon 2020.

Sensitivity of district heating system operation to heat demand reductions and electricity price variations: A Swedish example

International Nuclear Information System (INIS)

Åberg, M.; Widén, J.; Henning, D.

2012-01-01

In the future, district heating companies in Sweden must adapt to energy efficiency measures in buildings and variable fuel and electricity prices. Swedish district heating demands are expected to decrease by 1–2% per year and electricity price variations seem to be more unpredictable in the future. A cost-optimisation model of a Swedish local district heating system is constructed using the optimisation modelling tool MODEST. A scenario for heat demand changes due to increased energy efficiency in buildings, combined with the addition of new buildings, is studied along with a sensitivity analysis for electricity price variations. Despite fears that heat demand reductions will decrease co-generation of clean electricity and cause increased global emissions, the results show that anticipated heat demand changes do not increase the studied system's primary energy use or global CO 2 emissions. The results further indicate that the heat production plants and the fuels used within the system have crucial importance for the environmental impact of district heat use. Results also show that low seasonal variations in electricity price levels with relatively low winter prices promote the use of electric heat pumps. High winter prices on the other hand promote co-generation of heat and electricity in CHP plants. -- Highlights: ► A MODEST optimisation model of the Uppsala district heating system is built. ► The impact of heat demand change on heat and electricity production is examined. ► An electricity price level sensitivity analysis for district heating is performed. ► Heat demand changes do not increase the primary energy use or global CO 2 emissions. ► Low winter prices promote use of electric heat pumps for district heating production.

Heat islands over Mumbai as revealed by autorecorded thermograph data

Science.gov (United States)

Srivastava, A. K.; Voogt, James; Kshirsagar, S. R.; Srivastava, Kavita

2016-02-01

This study examined hourly temperature data of two locations of Mumbai metropolitan city. One data point (Coloba, Mumbai) is in centre of the city and the other one (Santacruz, Mumbai) is at the airport. The study finds that there were many occasions when night-time hourly temperatures over the city centre were considerably higher than that of the airport, even though temperature at the time of sunset at both the places was nearly same. In this study, the occasions, when hourly night-time temperature over city was more than that of the airport by objectively defined threshold value (3.0 ∘C in this study) for most of the hours in the night, were termed as heat island events. Analysis of the study reveals that these events are mostly confined to November-February months. The study also found that frequency of such events has doubled in recent two decades in comparison to the earlier two decades.

National Aboriginal and Torres Strait Islander Education Strategy 2015

Science.gov (United States)

Education Council, 2015

2015-01-01

Despite determined effort much more needs to be done to close the gap in Aboriginal and Torres Strait Islander education outcomes. Aboriginal and Torres Strait Islander people are the first Australians with the oldest continuing cultures in human history. Governments across Australia affirm the right of Aboriginal and Torres Islander people to…

Mass coral bleaching due to unprecedented marine heatwave in Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands).

Science.gov (United States)

Couch, Courtney S; Burns, John H R; Liu, Gang; Steward, Kanoelani; Gutlay, Tiffany Nicole; Kenyon, Jean; Eakin, C Mark; Kosaki, Randall K

2017-01-01

2014 marked the sixth and most widespread mass bleaching event reported in the Northwestern Hawaiian Islands, home to the Papahānaumokuākea Marine National Monument (PMNM), the world's second largest marine reserve. This event was associated with an unusual basin-scale warming in the North Pacific Ocean, with an unprecedented peak intensity of around 20°C-weeks of cumulative heat stress at Lisianksi Island. In situ bleaching surveys and satellite data were used to evaluate the relative importance of potential drivers of bleaching patterns in 2014, assess the subsequent morality and its effects on coral communities and 3D complexity, test for signs of regional acclimation, and investigate long-term change in heat stress in PMNM. Surveys conducted at four island/atoll (French Frigate Shoals, Lisianski Island, Pearl and Hermes Atoll, and Midway Atoll) showed that in 2014, percent bleaching varied considerably between islands/atolls and habitats (back reef/fore reef and depth), and was up to 91% in shallow habitats at Lisianski. The percent bleaching during the 2014 event was best explained by a combination of duration of heat stress measured by Coral Reef Watch's satellite Degree Heating Week, relative community susceptibility (bleaching susceptibility score of each taxon * the taxon's abundance relative to the total number of colonies), depth and region. Mean coral cover at permanent Lisianski monitoring sites decreased by 68% due to severe losses of Montipora dilatata complex, resulting in rapid reductions in habitat complexity. Spatial distribution of the 2014 bleaching was significantly different from the 2002 and 2004 bleaching events likely due to a combination of differences in heat stress and local acclimatization. Historical satellite data demonstrated heat stress in 2014 was unlike any previous event and that the exposure of corals to the bleaching-level heat stress has increased significantly in the northern PMNM since 1982, highlighting the increasing

Mass coral bleaching due to unprecedented marine heatwave in Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands.

Directory of Open Access Journals (Sweden)

Courtney S Couch

Full Text Available 2014 marked the sixth and most widespread mass bleaching event reported in the Northwestern Hawaiian Islands, home to the Papahānaumokuākea Marine National Monument (PMNM, the world's second largest marine reserve. This event was associated with an unusual basin-scale warming in the North Pacific Ocean, with an unprecedented peak intensity of around 20°C-weeks of cumulative heat stress at Lisianksi Island. In situ bleaching surveys and satellite data were used to evaluate the relative importance of potential drivers of bleaching patterns in 2014, assess the subsequent morality and its effects on coral communities and 3D complexity, test for signs of regional acclimation, and investigate long-term change in heat stress in PMNM. Surveys conducted at four island/atoll (French Frigate Shoals, Lisianski Island, Pearl and Hermes Atoll, and Midway Atoll showed that in 2014, percent bleaching varied considerably between islands/atolls and habitats (back reef/fore reef and depth, and was up to 91% in shallow habitats at Lisianski. The percent bleaching during the 2014 event was best explained by a combination of duration of heat stress measured by Coral Reef Watch's satellite Degree Heating Week, relative community susceptibility (bleaching susceptibility score of each taxon * the taxon's abundance relative to the total number of colonies, depth and region. Mean coral cover at permanent Lisianski monitoring sites decreased by 68% due to severe losses of Montipora dilatata complex, resulting in rapid reductions in habitat complexity. Spatial distribution of the 2014 bleaching was significantly different from the 2002 and 2004 bleaching events likely due to a combination of differences in heat stress and local acclimatization. Historical satellite data demonstrated heat stress in 2014 was unlike any previous event and that the exposure of corals to the bleaching-level heat stress has increased significantly in the northern PMNM since 1982, highlighting

Application of a New Dynamic Heating System Model Using a Range of Common Control Strategies

Directory of Open Access Journals (Sweden)

Joshua Fong

2016-06-01

Full Text Available This research investigates the overall heating energy consumptions using various control strategies, secondary heat emitters, and primary plant for a building. Previous research has successfully demonstrated that a dynamic distributed heat emitter model embedded within a simplified third-order lumped parameter building model is capable of achieving improved results when compared to other commercially available modelling tools. With the enhanced ability to capture transient effects of emitter thermal capacity, this research studies the influence of control strategies and primary plant configurations on the rate of energy consumption of a heating system. Four alternative control strategies are investigated: zone feedback; weather-compensated; a combination of both of these methods; and thermostatic control. The plant alternative configurations consist of conventional boilers, biomass boilers, and heat pumps supporting radiator heating and underfloor heating. The performance of the model is tested on a primary school building and can be applied to any residential or commercial building with a heating system. Results show that the new methods reported offer greater detail and rigor in the conduct of building energy modelling.

Development Options as Strategies for Conflict Reduction in ...

African Journals Online (AJOL)

This paper explores development options as effective strategies for conflict reduction in the Cross River National Park, Nigeria. It also discusses the tensions that result from the different development and conservation priorities that confront such humaninhabited protected areas as the Cross River National Park. The success ...

Daily variation of urban heat island effect and its correlations to urban greenery: A case study of Adelaide

Directory of Open Access Journals (Sweden)

Ali Soltani

2017-12-01

Full Text Available Urban structure and landscape cause an artificial temperature increase in cities, known as the urban heat island effect. The magnitude of such urban–rural temperature difference varies in daily and seasonal basis. Daily patterns of urban heat accumulation in Adelaide is under investigation. In this paper, East–West air temperature profile of Adelaide metropolitan area was mapped in 60 journeys alongside a straight cross route connecting Adelaide Hills to the West Beach under clear sky between 26 July and 15 August 2013. The most intense urban–rural temperature differences of 5.9 °C occurred during midnight in Adelaide. However, maximum urban heat variation occurred during the late afternoon when the near-surface urban heat fluctuates by 2 °C between the CBD East and Western Parklands. During summer heatwaves, the afternoon heat stress limits public life vibrancy in Adelaide. Increased urban greenery can facilitate resilience to heat by providing shadow and evaporative cooling. A better understanding of daily urban heat variations and the cooling effect of urban greenery assists urban policy making and public life management in the context of climate change.

Applicability of salt reduction strategies in pizza crust.

Science.gov (United States)

Mueller, Eva; Koehler, Peter; Scherf, Katharina Anne

2016-02-01

In an effort to reduce population-wide sodium intake from processed foods, due to major health concerns, several different strategies for sodium reduction in pizza crust without any topping were evaluated by sensory analyses. It was possible to reduce sodium by 10% in one single step or to replace 30% of NaCl by KCl without a noticeable loss of salty taste. The late addition of coarse-grained NaCl (crystal size: 0.4-1.4 mm) to pizza dough led to an enhancement of saltiness through taste contrast and an accelerated sodium delivery measured in the mouth and in a model mastication simulator. Likewise, the application of an aqueous salt solution to one side of the pizza crust led to an enhancement of saltiness perception through faster sodium availability, leading to a greater contrast in sodium concentration. Each of these two strategies allowed a sodium reduction of up to 25% while maintaining taste quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

The contribution of geology and groundwater studies to city-scale ground heat network strategies: A case study from Cardiff, UK

Science.gov (United States)

Boon, David; Farr, Gareth; Patton, Ashley; Kendall, Rhian; James, Laura; Abesser, Corinna; Busby, Jonathan; Schofield, David; White, Debbie; Gooddy, Daren; James, David; Williams, Bernie; Tucker, David; Knowles, Steve; Harcombe, Gareth

2016-04-01

monitoring have provided an initial indication of ground constraints and opportunities supporting development of aquifer thermal energy systems in Cardiff. Ground models should consider the past and future anthropogenic processes that influence and modify the condition of the ground. These include heat losses from buildings, modification of the groundwater regime by artificial pumping, sewers, and other GSH schemes, and construction hazards such as buried infrastructure, old foundations, land contamination and un-exploded ordnance. This knowledge base forms the foundation for a 'whole life' approach for sustainable thermal use of the subsurface. Benefits of the approach include; timely and easy to understand information for land use and financial resource planning, reduced financial risk for developers and investors, clear evidence to help improve public perception of GSHP technology, and provision of independent environmental data to satisfy the needs of the regulator. References: Patton, A.M., Farr, G.J., Boon, D.P., James, D.R., Williams, B., Newell, A.J. 2015. Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy. Geophysical Research Abstracts. EGU 2015 Vienna, Austria. (Poster)

U.S. Virgin Islands Energy Road Map: Analysis

Energy Technology Data Exchange (ETDEWEB)

Lantz, E.; Olis, D.; Warren, A.

2011-09-01

This report lays out the strategy envisioned by the stakeholders in the U.S. Virgin Islands, U.S. Department of Energy, and U.S. Department of Interior to achieve the ambitious goal of achieving a 60% reduction in business-as-usual fossil fuel demand by 2025 (60x25) within the electricity sector. This work and supporting analysis provides a framework within which decisions can begin to be made, a concrete vision of what the future might hold, and a guide to determine what questions should follow.

Community Empowerment Strategy Based on Social and Cultural Capital of Coastal Communities at Makassar Island

Science.gov (United States)

Tanzil, Tanzil

2018-05-01

The study aims to (1) analyze the form and the function of social capital in fisher communities of Makasar Island (2) formulate a strategy of empowerment through reinforcement of social capital in fisher communities in Makasar Island. The methodological design used is a case study. The data is then analysed through descriptive-qualitative, an analysis carried out continuously from the collection of data until the investigation is completed. The study findings showed that the fisher communities in Makasar Island have social and cultural capital that can be identified on the forms of trust, values/norms, and networks in which each social and cultural capital has become a power for fishermen to survive and adapt to its environment. The results of this study also identify various problems related to the process of empowering fishing communities on the island of Makassar. The problems also become a constraint for fishermen to improve their business so that they obtain relatively low incomes. The problems are: firstly, the weakness on the use of technology so that the productivity of fishermen is relatively low and the small business scale, the second, the difficulty in business development because of the limited access to capital and the third, the poor of business management as the result of limited ability in business management. These factors then lead the fishing communities on the island of Makasar powerless to exploit the rich potential of marine resources.

Renewable energy islands in Europe

Energy Technology Data Exchange (ETDEWEB)

Oestergaard, Iben [ed.

1998-12-31

This publication includes a compiled presentation of various aspects concerning the possible transformation of some European islands into renewable energy communities and these projects were presented by a selection of pioneer islands at the first European Seminar on Renewable Energy Islands, held on the Danish island of Samsoee, 29-30 June 1998. This issue has increased in importance with the presentation of the ambitious EU-White Paper: `Energy for the future: Renewable Sources of Energy` which was adopted in 1998. One of the key elements of the strategy for an accelerated implementation of renewable energy is to transform 100 localities within Europe into communities which are to be 100% self-sufficient with renewable energy before 2010. In line with this strategy, the Danish Government appointed the island of Samsoe towards the end of 1997 to be the first `official` Danish, renewable energy island. This is to serve as a demonstration project for other local communities, both in Denmark as well as in the rest Europe. Gothland, Madeira, Canary Islands, Cape Verde, Arki, Crete, Minorca and Orkney Islands were represented. Environmental advantages of wind, solar and wave power for distant island communities were indicated. Serious savings would be achieved by limitation of fossil fuel import and utilization of local resources. (EG)

FINE STRUCTURE IN MANHATTAN’S DAYTIME URBAN HEAT ISLAND: A NEW DATASET

Directory of Open Access Journals (Sweden)

Brian Vant-Hull

2014-01-01

Full Text Available A street-level temperature and humidity dataset with high resol ution spatial and temporal components has been created for the island of Manhattan, suitab le for use by the urban health and modelling communities. It cons ists of a set of pedestrian measurements over the course of two summers converted into anomaly maps, and a set of ten light -post mounted installations measuring temperature, relative humidity, and illumination at t hree minute intervals over three months. The quality control and data reduction used to produce the anomaly maps is described, and the relationships between spatial and temporal v ariability are investigated. The data sets are available for down load via the project website.

Interactive uncertainty reduction strategies and verbal affection in computer-mediated communication

NARCIS (Netherlands)

Antheunis, M.L.; Schouten, A.P.; Valkenburg, P.M.; Peter, J.

2012-01-01

The goal of this study was to investigate the language-based strategies that computer-mediated communication (CMC) users employ to reduce uncertainty in the absence of nonverbal cues. Specifically, this study investigated the prevalence of three interactive uncertainty reduction strategies (i.e.,

Voting strategy for artifact reduction in digital breast tomosynthesis

International Nuclear Information System (INIS)

Wu Tao; Moore, Richard H.; Kopans, Daniel B.

2006-01-01

Artifacts are observed in digital breast tomosynthesis (DBT) reconstructions due to the small number of projections and the narrow angular range that are typically employed in tomosynthesis imaging. In this work, we investigate the reconstruction artifacts that are caused by high-attenuation features in breast and develop several artifact reduction methods based on a 'voting strategy'. The voting strategy identifies the projection(s) that would introduce artifacts to a voxel and rejects the projection(s) when reconstructing the voxel. Four approaches to the voting strategy were compared, including projection segmentation, maximum contribution deduction, one-step classification, and iterative classification. The projection segmentation method, based on segmentation of high-attenuation features from the projections, effectively reduces artifacts caused by metal and large calcifications that can be reliably detected and segmented from projections. The other three methods are based on the observation that contributions from artifact-inducing projections have higher value than those from normal projections. These methods attempt to identify the projection(s) that would cause artifacts by comparing contributions from different projections. Among the three methods, the iterative classification method provides the best artifact reduction; however, it can generate many false positive classifications that degrade the image quality. The maximum contribution deduction method and one-step classification method both reduce artifacts well from small calcifications, although the performance of artifact reduction is slightly better with the one-step classification. The combination of one-step classification and projection segmentation removes artifacts from both large and small calcifications

Economic assessment of greenhouse gas reduction through low-grade waste heat recovery using organic Rankine cycle (ORC)

Energy Technology Data Exchange (ETDEWEB)

Imran, Muhammad; Park, Byung Sik; Kim, Hyouck Ju; Usman, Muhammad [University of Science and Technology, Daejeon (Korea, Republic of); Lee, Dong Hyun [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

2015-02-15

Low-grade waste heat recovery technologies reduce the environmental impact of fossil fuels and improve overall efficiency. This paper presents the economic assessment of greenhouse gas (GHG) reduction through waste heat recovery using organic Rankine cycle (ORC). The ORC engine is one of the mature low temperature heat engines. The low boiling temperature of organic working fluid enables ORC to recover low-temperature waste heat. The recovered waste heat is utilized to produce electricity and hot water. The GHG emissions for equivalent power and hot water from three fossil fuels-coal, natural gas, and diesel oil-are estimated using the fuel analysis approach and corresponding emission factors. The relative decrease in GHG emission is calculated using fossil fuels as the base case. The total cost of the ORC system is used to analyze the GHG reduction cost for each of the considered fossil fuels. A sensitivity analysis is also conducted to investigate the effect of the key parameter of the ORC system on the cost of GHG reduction. Throughout the 20-year life cycle of the ORC plant, the GHG reduction cost for R245fa is 0.02 $/kg to 0.04 $/kg and that for pentane is 0.04 $/kg to 0.05 $/kg. The working fluid, evaporation pressure, and pinch point temperature difference considerably affect the GHG emission.

Pure meat – public perceptions of risk reduction strategies in meat production

DEFF Research Database (Denmark)

Korzen, Sara Marie; Sandøe, Peter; Lassen, Jesper

2011-01-01

generally have an aversion to risk reduction strategies. Some variation was found, however, in the rejection of the strategies. Thus, more acceptable strategies are characterised by a low degree of technological interference, and by being close to the consumer’s experience in everyday life and/or familiar...

Integration of Small Solar tower Systems into Distributed Power Islands

Energy Technology Data Exchange (ETDEWEB)

Romero, M.; Marcos, M. J.; Tellez, F. M.; Blanco, M.; Fernandez, V.; Baonza, F.; Berger, S. [Ciemat, Madrid (Spain)

2000-07-01

One of the short-term priorities for renewable energies in Europe is their integration for local power supply into communities and energy islands (blocks of buildings, new neighborhoods in residential areas, shopping centers, hospitals, recreational areas, eco-paks, small rural areas or isolated ones such as islands or mountain communities). Following this strategy, the integration of small tower fields into so-called MIUS (Modular Integrated Utility Systems) is proposed. This application strongly influences field concepts leadings to modular multi-tower systems able to more closely track demand, meet reliability requirements with fewer megawatts of installed power and spread construction costs over time after output has begum. In addition, integration into single-cycle high-efficiency gas turbines plus waste-heat applications clearly increments the solar share. The chief questions are whether solar towers can be redesigned for such distributed markets and the keys to their feasibility. This paper includes the design and performance analysis of a 1.36-MW plant and integration in the MIUS system, as well as the expected cost of electricity and a sensitivity analysis of the small tower plant's performance with design parameters like heliostat configuration and tower height. A practical application is analyzed for a shopping center with 85% power demand during day-time by using a hybrid solar tower and a gas turbine producing electricity and waste heat for hot water and heating and cooling of spaces. The operation mode proposed is covering night demand with power from the grid and solar-gas power island mode during 14 hours daytime with a maximum power production of 1.36 MW. (Author) 26 refs.

Integration of Small Solar Tower Systems Into Distributed Power Islands

International Nuclear Information System (INIS)

Romero, M.; Marcos, M. J.; Tellez, F. M.; Blanco, M.; Fernandez, V.; Baonza, F.; Berger, S.

1999-01-01

One of the short-term priorities for renewable energies in Europe is their integration for local power supply into communities and energy islands (blocks of buildings, new neighborhoods in residential areas, shopping centers, hospitals, recreational areas, eco-parks, small rural areas or isolated ones such as islands or mountain communities). Following this strategy, the integration of small tower fields into so-called MIUS (Modular Integrated Utility Systems) is proposed. This application strongly influences field concepts leading to modular multi-tower systems able to more closely track demand, meet reliability requirements with fewer megawatts of installed power and spread construction costs over time after output has begun. In addition, integration into single-cycle high-efficiency gas turbines plus waste-heat applications clearly increments the solar share. The chief questions are whether solar towers can be redesigned for such distributed markets and the keys to their feasibility. This paper includes the design and performance analysis of a 1.36-MW plant and integration in the MIUS system, as well as the expected cost of electricity and a sensitivity analysis of the small tower plant's performance with design parameters like heliostats configuration and tower height. A practical application is analyzed for a shopping center with 85% power demand during day-time by using a hybrid solar tower and a gas turbine producing electricity and waste heat for hot water and heating and cooling of spaces. The operation mode proposed is covering night demand with power from the grid and solar-gas power island mode during 14 hours daytime with a maximum power production of 1.36 MW. (Author) 26 refs

Energy reduction in buildings in temperate and tropic regions utilizing a heat loss measuring device

DEFF Research Database (Denmark)

Sørensen, Lars Schiøtt

2012-01-01

There exist two ordinary ways to obtain global energy efficiency. One way is to make improvements on the energy production and supply side, and the other way is, in general, to reduce the consume of energy in the society. This paper has focus on the latter and especially the consume of energy...... for heating up, and cooling down our houses. There is a huge energy saving potential on this area reducing both the World climate problems and economy challenges as well. Heating of buildings in Denmark counts for approximately 40% of the entire national energy consume. Of this reason a reduction of heat...... losses from building envelopes are of great impor­tance in order to reach the Bologna CO2-emission reduction goals. Energy renovation of buildings is a topic of huge focus around the world these years. Not only expenses for heating in the tempered and arctic regions are of importance, but also expenses...

Canary Islands (Spain): Their Importance in NATO’s Strategy.

Science.gov (United States)

1987-04-22

considered to be divided into two groups of * islands. One is the eastern islands, made up of Gran Canaria, Lanzarote and Fuerteventura and the other...feet (1,370 to 2,130 meters) and Lanzarote and Fuerteventura, the islands closest to the African coast, do not exceed 2,400 feet (730 meters) in...heights. Each island, except Lanzarote and Fuerteventura, is divided into two faces, one to the north, exposed to the humid winds, full of vegetation

An urban heat island in tropical area investigated by remote sensing: Belo Horizonte City

International Nuclear Information System (INIS)

Gastelois, B.C.R.J.; de Assis, E.S.

1992-01-01

The inappropriate urbanization process in tropical areas causes local climatic alterations forming heat islands over the cities. In order to guide urban planning in the control of the environmental urban quality, as for the thermal comfort is concerned, it has developed a method to evaluate the thermal behavior of built and urban green areas. Two TM-LANDSAT images from Belo Horizonte City, the study area, were chosen based on summer and winter typical days statistically characterized. Bands 3 and 4 of these images were combined to produce a local vegetation index map. Band 6 was used to observe the warmer and cooler areas in the city. Some heat nucleons were identified through data analysis of remote sensing, meteorological and urban land use. The mean maximum temperature of the principal heat nuclei exceeds, in summer, the limit value of diurnal thermal comfort for the city climate, using Givoni's Bioclimatic Chart. During the day period, the areas with a lower vegetation index, more density and predominating horizontal settlements were the most warmer. The cooling effect of urban green areas was very local. Thus, it should be regularly distributed in the built areas. The limits of occupation density and edification could be fixed, too, considering its impacts on the urban thermal environment

Rwanda; Poverty Reduction Strategy Paper: Progress Report

OpenAIRE

International Monetary Fund

2011-01-01

Rwanda’s Economic Development and Poverty Reduction Strategy (EDPRS) covers the period 2008–12 and provides a medium-term framework for achieving the country’s long-term development aspirations as embodied in Rwanda Vision 2020, the seven-year Government of Rwanda (GoR) program, and the Millennium Development Goals. The economic cluster covers the macroeconomic and financial sector (energy, transport, information and communication technology (ICT) and Science, Technology and Innovation (STI),...

Spatio-Temporal Variability of Urban Heat Island and Urban Mobility

Science.gov (United States)

Kar, B.; Omitaomu, O.

2017-12-01

A 2016 report by the U.S. Census stated that while the rural areas cover 97% of the U.S. landmass, these areas house only 19.7% of the nation's population. Given that the U.S. coastal counties are home to more than 50% of the U.S. population, these urban areas are clustered along the coast that is susceptible to sea level rise induced impacts. In light of increasing climate variability and extreme events, it is pertinent to understand the Urban Heat Island (UHI) effect that results from increasing population density and mobility in the urban areas, and that contributes to increased energy consumption and temperature as well as unmitigated flooding events. For example, in Illinois, warmer summers contribute to heavy precipitation that overwhelms the region's drainage capacity. This study focuses on understanding the spatio-temporal variability of the relationship between population density and mobility distribution, and creation of UHI due to temperature change in selected cities across the U.S. This knowledge will help us understand the role of UHI in energy-water nexus in urban areas, specifically, energy consumption.

The Impact of Albedo Increase to Mitigate the Urban Heat Island in Terni (Italy Using the WRF Model

Directory of Open Access Journals (Sweden)

Elena Morini

2016-10-01

Full Text Available The impacts of the urban heat island (UHI phenomenon on energy consumption, air quality, and human health have been widely studied and described. Mitigation strategies have been developed to fight the UHI and its detrimental consequences. A potential countermeasure is the increase of urban albedo by using cool materials. Cool materials are highly reflective materials that can maintain lower surface temperatures and thus can present an effective solution to mitigate the UHI. Terni’s proven record of high temperatures along with related environmental and comfort issues in its urban areas have reflected the local consequences of global warming. On the other hand, it promoted integrated actions by the government and research institutes to investigate solutions to mitigate the UHI effects. In this study, the main goal is to investigate the effectiveness of albedo increase as a strategy to tackle the UHI, by using the Weather Research and Forecasting (WRF mesoscale model to simulate the urban climate of Terni (Italy. Three different scenarios through a summer heat wave in the summer of 2015 are analyzed. The Base Scenario, which simulates the actual conditions of the urban area, is the control case. In the Albedo Scenario (ALB Scenario, the albedo of the roof, walls and road of the whole urban area is increased. In the Albedo-Industrial Scenario (ALB-IND Scenario, the albedo of the roof, walls and road of the area occupied by the main industrial site of Terni, located in close proximity to the city center, is increased. The simulation results show that the UHI is decreased up to 2 °C both at daytime and at nighttime in the ALB and in ALB-IND Scenarios. Peak temperatures in the urban area can be decreased by 1 °C at daytime, and by about 2 °C at nighttime. Albedo increase in the area of interest might thus represent an opportunity to decrease the UHI effect and its consequences.

The contribution of urbanization to recent extreme heat events and white roof mitigation strategy in the Beijing-Tianjin-Hebei metropolitan area

Science.gov (United States)

Wang, Mingna

2015-04-01

The UHI effect can aggravate summertime heat waves and strongly influence human comfort and health, leading to greater mortality in metropolitan areas. Many geo-engineering technological strategies have been proposed to mitigate climate warming, and for the UHI, increasing the albedo of artificial urban surfaces (rooftops or pavements) has been considered a lucrative and effective way to cool cities. The objective of this work is to quantify the contribution of urbanization to recent extreme heat events of the early 21st century in the Beijing-Tianjin-Hebei metropolitan area, using the mesoscale WRF model coupled with a single urban canopy model and actual urban land cover datasets. This work also investigates a simulation of the regional effects of white roof technology by increasing the albedo of urban areas in the urban canopy model to mitigate the urban heat island, especially in extreme heat waves. The results show that urban land use characteristics that have evolved over the past ~20 years in the Beijing-Tianjin-Hebei metropolitan area have had a significant impact on the extreme temperatures occurring during extreme heat events. Simulations show that new urban development has caused an intensification and expansion of the areas experiencing extreme heat waves with an average increase in temperature of approximately 0.60°C. This change is most obvious at night with an increase up to 0.95°C, for which the total contribution of anthropogenic heat is 34%. We also simulate the effects of geo-engineering strategies increasing the albedo of urban roofs. White roofs reflect a large fraction of incoming sunlight in the daytime, which reduced the net radiation so that the roof surface keep at a lower temperature than regular solar-absorptive roofs. Urban net radiation decreases by approximately 200 W m-2 at local noon because of high solar reflectance of white roofs, which cools the daytime urban temperature afer sunrise, with the largest decrease of almost -0.80�

Pawtuxet River, Warwick, Rhode Island. Local Flood Damage Reduction Study. Detailed Project Report for Water Resources Development.

Science.gov (United States)

1982-06-01

Warwich (Belmont Park) Rhode Island. Cover Title Reads: Flood Damage Reduction IS. KEY WORDS (Ce൘.. asm towvee aide of mogoseem aid 1~110j IV MeMAw...cost of the premium paid by policy holders. The actual premium is less than the actuarial rate by the amount of the subsidy which represents one facet...coverage limits, therefore it was not necessary to calculate additional coverage premiums based on actuarial rates. The annual average subsidized

Heat stress control in the TMI-2 [Three Mile Island Unit 2] defueling and decontamination activities

International Nuclear Information System (INIS)

Schork, J.S.; Parfitt, B.A.

1988-01-01

During the initial stages of the Three Mile Island Unit 2 (TMI-2) defueling and decontamination activities for the reactor building, it was realized that the high levels of loose radioactive contamination would require the use of extensive protective clothing by entry personnel. While there was no doubt that layered protective clothing protects workers from becoming contaminated, it was recognized that these same layers of clothing would impose a very significant heat stress burden. To prevent the potentially serious consequences of a severe reaction to heat stress by workers in the hostile environment of the TMI-2 reactor building and yet maintain the reasonable work productivity necessary to perform the recovery adequately, an effective program of controlling worker exposure to heat stress had to be developed. Body-cooling devices produce a flow of cool air, which is introduced close to the skin to remove body heat through convection and increased sweat evaporation. The cooling effect produced by the Vortex tube successfully protected the workers from heat stress, however, there were several logistical and operational problems that hindered extensive use of these devices. The last type of cooling garment examined was the frozen water garment (FWG) developed by Elizier Kamon at the Pennsylvania State University as part of an Electric Power Research Institute research grant. Personal protection, i.e., body cooling, engineering controls, and administrative controls, have been implemented successfully

Preliminary study of the decay heat removal strategy for the gas demonstrator allegro

Energy Technology Data Exchange (ETDEWEB)

Mayer, Gusztáv, E-mail: gusztav.mayer@energia.mta.hu [Hungarian Academy of Sciences, Centre for Energy Research, P.O. Box 49, H-1525 Budapest (Hungary); Bentivoglio, Fabrice, E-mail: fabrice.bentivoglio@cea.fr [CEA/DEN/DM2S/STMF/LMES, F-38054, Grenoble (France)

2015-05-15

Highlights: • Improved decay heat removal strategy was adapted for the 75 MW ALLEGRO MOX core. • New nitrogen injection strategy was proposed for the DEC LOCA transients. • Preliminary CATHARE study shows that most of the investigated transients fulfill criteria. • Further improvements and optimizations are needed for nitrogen injection. - Abstract: The helium cooled Gas Fast Reactor (GFR) is one of the six reactor concepts selected in the frame of the Generation IV International Forum. Since no gas cooled fast reactor has ever been built, a medium power demonstrator reactor – named ALLEGRO – is necessary on the road towards the 2400 MWth GFR power reactor. The French Commissariat à l’Energie Atomique (CEA) completed a wide range of studies during the early stage of development of ALLEGRO, and later the ALLEGRO reactor concept was developed in several European Union projects in parallel with the GFR2400. The 75 MW thermal power ALLEGRO is currently developed in the frame of the European ALLIANCE project. As a result of the collaboration between CEA and the Hungarian Academy of Sciences Centre for Energy Research (MTA EK) new improvements were done in the safety approach of ALLEGRO. A complete Decay Heat Removal (DHR) strategy was devised, relying on the primary circuits as a first way to remove decay heat using pony-motors to drive the primary blowers, and on the secondary and tertiary circuits being able to work in forced or natural circulation. Three identical dedicated loops circulating in forced convection are used as a second way to remove decay heat, and these loops can circulate in natural convection for pressurized transients, providing a third way to remove decay heat in case of accidents when the primary circuit is still under pressure. The possibility to use nitrogen to enhance both forced and natural circulation is discussed. This DHR strategy is supported by a wide range of accident transient simulations performed using the CATHARE2 code

Effect of stigma reduction intervention strategies on HIV test uptake in low- and middle-income countries

DEFF Research Database (Denmark)

Thapa, Subash; Hannes, Karin; Cargo, Margaret

2015-01-01

BACKGROUND: Several stigma reduction intervention strategies have been developed and tested for effectiveness in terms of increasing human immunodeficiency virus (HIV) test uptake. These strategies have been more effective in some contexts and less effective in others. Individual factors......, such as lack of knowledge and fear of disclosure, and social-contextual factors, such as poverty and illiteracy, might influence the effect of stigma reduction intervention strategies on HIV test uptake in low- and middle-income countries. So far, it is not clearly known how the stigma reduction intervention...... strategies interact with these contextual factors to increase HIV test uptake. Therefore, we will conduct a review that will synthesize existing studies on stigma reduction intervention strategies to increase HIV test uptake to better understand the mechanisms underlying this process in low- and middle...

Reduction of NOx emissions when burning low heating value gas

International Nuclear Information System (INIS)

Gustafsson, R.; Oskarsson, J.; Waldheim, L.

1993-09-01

On the gasification of nitrogen-rich fuel the nitrogen from the fuel goes into the gas phase in the form of ammonia and hydrogen cyanide and also nitrogen containing tars. When the gas is combusted the nitrogen compounds are oxidized to a great extent to NO x and, therefore, high NO x emissions can be found on the combustion of low heating value gas produced from energy forest wood chips as is also the case with direct combustion of nitrogen rich fuels. An experimental study has been carried out where the important parameters for designing a combustion chamber for low heating value gases have been studied in order to obtain maximum reduction of NO x emissions. The effect of tar cracking using dolomite on these emissions and the effect of parameters such as the addition of steam has also been tested. The tests were carried out with energy forest wood chips with 0.3% nitrogen. The gasification was carried out in a pyrolysis reactor, operated to yield a low heating value gas, and which was coupled to a simplified gas turbine combustion chamber at atmospheric pressure. The results show that the main part of the nitrogen in the fuel is found as ammonia in the low heating value gas. With this type of gasification the conversion of fuel nitrogen to ammonia in the gas is equivalent to 500-600 mg/MJ, calculated as NO 2 . Only very low amounts of hydrogen cyanide have been noted and no nitrogen containing tar components have been found. No apparent effect of steam additions has been noted. On the other hand the distribution of air in the combustion chamber and residence time during the under stoichiometric conditions are of great importance for the NO x reduction. Depending on the air distribution the emissions of NO 2 varied between 100 and 250 mg/MJ, calculated as NO 2 . 23 refs, 11 figs, 2 tabs

Quality and sensitivity of high-resolution numerical simulation of urban heat islands

International Nuclear Information System (INIS)

Li, Dan; Bou-Zeid, Elie

2014-01-01

High-resolution numerical simulations of the urban heat island (UHI) effect with the widely-used Weather Research and Forecasting (WRF) model are assessed. Both the sensitivity of the results to the simulation setup, and the quality of the simulated fields as representations of the real world, are investigated. Results indicate that the WRF-simulated surface temperatures are more sensitive to the planetary boundary layer (PBL) scheme choice during nighttime, and more sensitive to the surface thermal roughness length parameterization during daytime. The urban surface temperatures simulated by WRF are also highly sensitive to the urban canopy model (UCM) used. The implementation in this study of an improved UCM (the Princeton UCM or PUCM) that allows the simulation of heterogeneous urban facets and of key hydrological processes, together with the so-called CZ09 parameterization for the thermal roughness length, significantly reduce the bias (<1.5 °C) in the surface temperature fields as compared to satellite observations during daytime. The boundary layer potential temperature profiles are captured by WRF reasonable well at both urban and rural sites; the biases in these profiles relative to aircraft-mounted senor measurements are on the order of 1.5 °C. Changing UCMs and PBL schemes does not alter the performance of WRF in reproducing bulk boundary layer temperature profiles significantly. The results illustrate the wide range of urban environmental conditions that various configurations of WRF can produce, and the significant biases that should be assessed before inferences are made based on WRF outputs. The optimal set-up of WRF-PUCM developed in this paper also paves the way for a confident exploration of the city-scale impacts of UHI mitigation strategies in the companion paper (Li et al 2014). (letter)

The role of city size and urban form in the surface urban heat island.

Science.gov (United States)

Zhou, Bin; Rybski, Diego; Kropp, Jürgen P

2017-07-06

Urban climate is determined by a variety of factors, whose knowledge can help to attenuate heat stress in the context of ongoing urbanization and climate change. We study the influence of city size and urban form on the Urban Heat Island (UHI) phenomenon in Europe and find a complex interplay between UHI intensity and city size, fractality, and anisometry. Due to correlations among these urban factors, interactions in the multi-linear regression need to be taken into account. We find that among the largest 5,000 cities, the UHI intensity increases with the logarithm of the city size and with the fractal dimension, but decreases with the logarithm of the anisometry. Typically, the size has the strongest influence, followed by the compactness, and the smallest is the influence of the degree to which the cities stretch. Accordingly, from the point of view of UHI alleviation, small, disperse, and stretched cities are preferable. However, such recommendations need to be balanced against e.g. positive agglomeration effects of large cities. Therefore, trade-offs must be made regarding local and global aims.

Remote Sensing of the Urban Heat Island Effect Across Biomes in the Continental USA

Science.gov (United States)

Imhoff, Marc L.; Zhang, Ping; Wolfe, Robert E.; Bounoua, Lahouari

2010-01-01

Impervious surface area (ISA) from the Landsat TM-based NLCD 2001 dataset and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) skin temperature amplitude and its relationship to development intensity, size, and ecological setting for 38 of the most populous cities in the continental United States. Development intensity zones based on %ISA are defined for each urban area emanating outward from the urban core to the nonurban rural areas nearby and used to stratify sampling for land surface temperatures and NDVI. Sampling is further constrained by biome and elevation to insure objective intercomparisons between zones and between cities in different biomes permitting the definition of hierarchically ordered zones that are consistent across urban areas in different ecological setting and across scales. We find that ecological context significantly influences the amplitude of summer daytime UHI (urban-rural temperature difference) the largest (8 C average) observed for cities built in biomes dominated by temperate broadleaf and mixed forest. For all cities combined, ISA is the primary driver for increase in temperature explaining 70% of the total variance in LST. On a yearly average, urban areas are substantially warmer than the non-urban fringe by 2.9 C, except for urban areas in biomes with arid and semiarid climates. The average amplitude of the UHI is remarkably asymmetric with a 4.3 C temperature difference in summer and only 1.3 C in winter. In desert environments, the LST's response to ISA presents an uncharacteristic "U-shaped" horizontal gradient decreasing from the urban core to the outskirts of the city and then increasing again in the suburban to the rural zones. UHI's calculated for these cities point to a possible heat sink effect. These observational results show that the urban heat island amplitude both increases with city size and is seasonally

A wedge strategy for mitigation of urban warming in future climate scenarios

Science.gov (United States)

Zhao, Lei; Lee, Xuhui; Schultz, Natalie M.

2017-07-01

Heat stress is one of the most severe climate threats to human society in a future warmer world. The situation is further exacerbated in urban areas by urban heat islands (UHIs). Because the majority of world's population is projected to live in cities, there is a pressing need to find effective solutions for the heat stress problem. We use a climate model to investigate the effectiveness of various urban heat mitigation strategies: cool roofs, street vegetation, green roofs, and reflective pavement. Our results show that by adopting highly reflective roofs, almost all the cities in the United States and southern Canada are transformed into white oases - cold islands caused by cool roofs at midday, with an average oasis effect of -3.4 K in the summer for the period 2071-2100, which offsets approximately 80 % of the greenhouse gas (GHG) warming projected for the same period under the RCP4.5 scenario. A UHI mitigation wedge consisting of cool roofs, street vegetation, and reflective pavement has the potential to eliminate the daytime UHI plus the GHG warming.

Radiant heat loss, an unexploited path for heat stress reduction in shaded cattle.

Science.gov (United States)

Berman, A; Horovitz, T

2012-06-01

Rbal with increasing roof height and a reduction in rate of decrease with increasing level of indirect radiation. Roof height as an Rbal attenuator declined with increasing indirect radiation level. The latter factor might be reduced by lowering roof surface radiation absorption and through roof heat transfer, as well as by use of shade structure elements to reduce indirect radiation in the shaded area. Radiant heat from the cow body surface may be reduced by lower cow density. Radiant heat attenuation may thus further elevate animal productivity in warm climates, with no associated operation costs. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Subjective heat stress of urban citizens: influencing factors and coping strategies

Science.gov (United States)

Kunz-Plapp, Tina; Hackenbruch, Julia; Schipper, Hans

2014-05-01

Given urbanization trend and a higher probability of heat waves in Europe, heat discomfort or heat stress for the population in cities is a growing concern that is addressed from various perspectives, such as urban micro climate, urban and spatial planning, human health, work performance and economic impacts. This presentation focuses on subjective heat stress experienced by urban citizens. In order to better understand individual subjective heat stress of urban citizens and how different measures to cope with heat stress in everyday life are applied, a questionnaire survey was conducted in Karlsruhe, Germany. Karlsruhe is located in one of the warmest regions in Germany and holds the German temperature record of 40.2°C in August 2003. In 2013, two hot weather periods with continuous heat warnings by the German Weather Service for 7 and 8 days occurred during the last 10 days of July and first 10 days of August 2013 with an inofficial maximum temperature of again 40.2°C on July 27th in Karlsruhe (not taken by the official network of the German Weather Service). The survey data was collected in the six weeks after the heat using an online-questionnaire on the website of the South German Climate Office that was announced via newspapers and social media channels to reach a wide audience in Karlsruhe. The questionnaire was additionally sent as paper version to groups of senior citizens to ensure having enough respondents from this heat sensitive social group in the sample. The 428 respondents aged 17-94 show differences in subjective heat stress experienced at home, at work and during various typical activities in daily routine. They differ also in the measures they used to adjust to and cope with the heat such as drinking more, evading the heat, seeking cooler places, changing daily routines, or use of air condition. Differences in heat stress can be explained by housing type, age, subjective health status, employment, and different coping measures and strategies

Reduction of deoxynivalenol in barley by treatment with aqueous sodium carbonate and heat.

Science.gov (United States)

Abramson, David; House, James D; Nyachoti, C Martin

2005-11-01

Naturally contaminated lots of Canadian barley containing either 18.4 or 4.3 microg/g deoxynivalenol (DON) were heated at 80 degrees C, with small amounts of water or 1 M sodium carbonate solution to study the rate of DON reduction. Samples were heated in sealed polypropylene containers for periods of up to 8 days. In the 18.4 microg/g DON barley, rapid reductions were observed: with no solutions added, DON declined to 14.7 microg/g after 1 day, and to 4.9 microg/g after 8 days solely due to heat; with water at 10 mL/100 g barley, DON levels reached 3.7 microg/g after 8 days; with 1 M sodium carbonate solution added at 10 mL/100 g barley, DON declined to 4.7 microg/g after 1 day, and to 0.4 microg/g after 8 days; with 20 mL/100 g barley, DON declined to 1.4 microg/g after 1 day and to near-zero levels after 8 days. In the 4.3 microg/g DON barley, more gradual reductions were evident: with no solutions added, DON declined to 2.9 microg/g after 8 days solely due to heat; with water at 10 mL/100 g barley, DON levels reached 2.3 microg/g after 8 days; with 1 M sodium carbonate solution added at 10 mL/100 g barley, DON declined to 2.7 microg/g after 1 day, and to near-zero levels after 8 days; with 20 mL/100 g barley, DON declined to 1.4 microg/g after 1 day and to near-zero levels after 3, 5 and 8 days.

The Impacts of Heating Strategy on Soil Moisture Estimation Using Actively Heated Fiber Optics.

Science.gov (United States)

Dong, Jianzhi; Agliata, Rosa; Steele-Dunne, Susan; Hoes, Olivier; Bogaard, Thom; Greco, Roberto; van de Giesen, Nick

2017-09-13

Several recent studies have highlighted the potential of Actively Heated Fiber Optics (AHFO) for high resolution soil moisture mapping. In AHFO, the soil moisture can be calculated from the cumulative temperature ( T cum ), the maximum temperature ( T max ), or the soil thermal conductivity determined from the cooling phase after heating ( λ ). This study investigates the performance of the T cum , T max and λ methods for different heating strategies, i.e., differences in the duration and input power of the applied heat pulse. The aim is to compare the three approaches and to determine which is best suited to field applications where the power supply is limited. Results show that increasing the input power of the heat pulses makes it easier to differentiate between dry and wet soil conditions, which leads to an improved accuracy. Results suggest that if the power supply is limited, the heating strength is insufficient for the λ method to yield accurate estimates. Generally, the T cum and T max methods have similar accuracy. If the input power is limited, increasing the heat pulse duration can improve the accuracy of the AHFO method for both of these techniques. In particular, extending the heating duration can significantly increase the sensitivity of T cum to soil moisture. Hence, the T cum method is recommended when the input power is limited. Finally, results also show that up to 50% of the cable temperature change during the heat pulse can be attributed to soil background temperature, i.e., soil temperature changed by the net solar radiation. A method is proposed to correct this background temperature change. Without correction, soil moisture information can be completely masked by the background temperature error.

Assessment of urban heat Island for Craiova from satellite-based LST

Science.gov (United States)

Udristioiu, Mihaela Tinca; Velea, Liliana; Bojariu, Roxana; Sararu, Silviu Constantin

2017-12-01

The urban heat island is defined as an excess of heating in urban areas compared with surrounding rural zones which is illustrated by higher surface and air temperatures in the inner part of the cities. The aim of this study is to identify the UHI effect for Craiova - the largest city in the South-Western part of Romania - and to assess its intensity during summer. To this end, MODIS Land surface temperature (LST) for day and night for summer months (June, July, August), in the interval 2002-2017, as well as yearly Land Cover Type (LCT) data also from MODIS were employed. Furthermore, measurements of air and soil temperature from meteorological station Craiova, available from the National Meteorological Administration database, were used to investigate their relation with LST. The analysis shows that in the urban area of Craiova the long-term summer mean LST is about 4 °C (2 °C), higher than in the rural area during daytime (nighttime). During high temperatures episodes, the mean daytime LST reaches 45-47 °C in the city, while the difference from the rural surrounding area is of 2-3 °C. A high correlation (0.77-0.83) is found between LST and air temperature for all land-use types in the area considered. Both LST and 2m-air temperature time-series manifest an increasing linear tendency over the period considered, being more pronounced during the day.

Reduction of repository heat load using advanced fuel cycles

International Nuclear Information System (INIS)

Preston, Jeff; Miller, L.F.

2008-01-01

With the geologic repository at Yucca Mountain already nearing capacity full before opening, advanced fuel cycles that introduce reprocessing, fast reactors, and temporary storage sites have the potential to allow the repository to support the current reactor fleet and future expansion. An uncertainty analysis methodology that combines Monte Carlo distribution sampling, reactor physics data simulation, and neural network interpolation methods enable investigation into the factor reduction of heat capacity by using the hybrid fuel cycle. Using a Super PRISM fast reactor with a conversion ratio of 0.75, burn ups reach up to 200 MWd/t that decrease the plutonium inventory by about 5 metric tons every 12 years. Using the long burn up allows the footprint of 1 single core loading of FR fuel to have an integral decay heat of about 2.5x10 5 MW*yr over a 1500 year period that replaces the footprint of about 6 full core loadings of LWR fuel for the number of years required to fuel the FR, which have an integral decay heat of about.3 MW*yr for the same time integral. This results in an increase of a factor of 4 in repository support capacity from implementing a single fast reactor in an equilibrium cycle. (authors)

Resonant island divertor experiments on text

International Nuclear Information System (INIS)

deGrassie, J.S.; Evans, T.E.; Jackson, G.L.

1988-09-01

The first experimental tests of the resonant island divertor (RID) concept have been carried out on the Texas Experimental Tokamak (TEXT). Modular perturbation coils produce static resonant magnetic fields at the tokamak boundary. The resulting magnetic islands are used to guide heat and particle fluxes around a small scoop limiter head. An enhancement in the limiter collection efficiency over the nonisland operation, as evidenced by enhanced neutral density within the limiter head, of up to a factor of 4 is obtained. This enhancement is larger than one would expect given the measured magnitude of the cross-field particle transport in TEXT. It is proposed that electrostatic perturbations occur which enhance the ion convection rate around the islands. Preliminary experiments utilizing electron cyclotron heating (ECH) in conjunction with RID operation have also have been performed. 6 refs., 3 figs

Predicting the impact of logging activities on soil erosion and water quality in steep, forested tropical islands

Science.gov (United States)

Wenger, Amelia S.; Atkinson, Scott; Santini, Talitha; Falinski, Kim; Hutley, Nicholas; Albert, Simon; Horning, Ned; Watson, James E. M.; Mumby, Peter J.; Jupiter, Stacy D.

2018-04-01

Increasing development in tropical regions provides new economic opportunities that can improve livelihoods, but it threatens the functional integrity and ecosystem services provided by terrestrial and aquatic ecosystems when conducted unsustainably. Given the small size of many islands, communities may have limited opportunities to replace loss and damage to the natural resources upon which they depend for ecosystem service provisioning, thus heightening the need for proactive, integrated management. This study quantifies the effectiveness of management strategies, stipulated in logging codes-of-practice, at minimizing soil erosion and sediment runoff as clearing extent increases, using Kolombangara Island, Solomon Islands as a case study. Further, we examine the ability of erosion reduction strategies to maintain sustainable soil erosion rates and reduce potential downstream impacts to drinking water and environmental water quality. We found that increasing land clearing—even with best management strategies in place—led to unsustainable levels of soil erosion and significant impacts to downstream water quality, compromising the integrity of the land for future agricultural uses, consistent access to clean drinking water, and important downstream ecosystems. Our results demonstrate that in order to facilitate sustainable development, logging codes of practice must explicitly link their soil erosion reduction strategies to soil erosion and downstream water quality thresholds, otherwise they will be ineffective at minimizing the impacts of logging activities. The approach taken here to explicitly examine soil erosion rates and downstream water quality in relation to best management practices and increasing land clearing should be applied more broadly across a range of ecosystems to inform decision-making about the socioeconomic and environmental trade-offs associated with logging, and other types of land use change.

GHG REDUCTION POTENTIAL OF BIOGAS RESOURCE UTILZATION IN HOLBÆK’S HEATING AND ELECTRICITY SECTOR

OpenAIRE

DAO, THI THU HUONG DIU

2013-01-01

This project is set out to identify the GHG reduction potentials of the 3 identified biogas plants in the Holbæk municipality. The GHG reduction of the 3 plants will be calculated in association with 2 biogas applications, which are CHP and upgrading biogas for individual heating purposes. The GHG reduction potentials of the 3 plants will be reflected to Holbæk’s specific GHG reduction target to see how these potentials contribute to the set goal. Departure from that, future version of biogas...

Desert heat island study in winter by mobile transect and remote sensing techniques

Science.gov (United States)

Sun, Chen-Yi; Brazel, Anthony J.; Chow, Winston T. L.; Hedquist, Brent C.; Prashad, Lela

2009-10-01

A familiar problem in urban environments is the urban heat island (UHI), which potentially increases air conditioning demands, raise pollution levels, and could modify precipitation patterns. The magnitude and pattern of UHI effects have been major concerns of a lot of urban environment studies. Typically, research on UHI magnitudes in arid regions (such as Phoenix, AZ, USA) focuses on summer. UHI magnitudes in Phoenix (more than three million population) attain values in excess of 5°C. This study investigated the early winter period—a time when summer potential evapotranspiration >250 mm has diminished to 8.0°C, comparable to summertime UHI conditions. Through analysis of the Oke (1998) weather factor ΦW, it was determined thermally induced nighttime cool drainage winds could account for inflating the UHI magnitude in winter.

"I Feel Suffocated:" Understandings of Climate Change in an Inner City Heat Island.

Science.gov (United States)

Singer, Merrill; Hasemann, Jose; Raynor, Abigail

2016-01-01

Global climate change is contributing to a range of adverse environmental and weather shifts, including more intense and more frequent heatwaves and an intensification of the urban heat island effect. These changes are known to produce a set of significant and differentially distributed health problems, with a particularly high burden among poor and marginalized populations. In this article, we report findings from a qualitative study of community knowledge, attitudes, health and other concerns, and behavioral responses regarding mounting urban temperatures and related environmental health issues among Latinos living in the city of Hartford, CT in northeast United States. Findings suggest the need for enhanced participation in knowledge dissemination and preparedness planning based on the coproduction of knowledge about climate change and community responses to it. The special role of anthropology in such efforts is highlighted.

The urban heat island in the city of Poznań as derived from Landsat 5 TM

Science.gov (United States)

Majkowska, Agnieszka; Kolendowicz, Leszek; Półrolniczak, Marek; Hauke, Jan; Czernecki, Bartosz

2017-05-01

To study urban heat island (UHI), Landsat 5 TM data and in situ measurements of air temperature from nine points in Poznań (Poland) for the period June 2008-May 2013 were used. Based on data from measurement points located in different types of land use, the surface urban heat island (SUHI) maps were created. All available and quality-controlled Landsat 5 TM images from 15 unique days were used to obtain the characteristics of land surface temperature (LST) and UHI intensity. In addition, spatial analysis of UHI was conducted on the basis of Corine Land Cover 2006 dataset. In situ measurements at a height of 2 m above ground level show that the UHI is a common occurrence in Poznań with a mean annual intensity of 1.0 °C. The UHI intensity is greater during the warm half of the year. Moreover, results based on the remote sensing data and the Corine Land Cover 2006 indicate that the highest value of the mean LST anomalies (3.4 °C) is attained by the continuous urban fabric, while the lowest value occurs within the broad-leaved forests (-3.1 °C). To re-count from LST to the air temperature at a height of 2 m above ground level ( T agl), linear and non-linear regression models were created. For both models, coefficients of determination equal about 0.80, with slightly higher value for the non-linear approach, which was applied to estimate the T agl spatial variability over the city of Poznań.

Definitional Hegemony as a Public Relations Strategy: The Rhetoric of the Nuclear Power Industry after Three Mile Island.

Science.gov (United States)

Dionisopoulos, George N.; Crable, Richard E.

1988-01-01

Examines (1) definitional hegemony as one of several rhetorical options available to issue managers; (2) the post-accident rhetorical context of the Three Mile Island nuclear crisis; and (3) the specific strategies utilized to deal with this crisis. Assesses the nuclear industry's public relations efforts. (MS)

Estimation of heat rejection based on the air conditioner use time and its mitigation from buildings in Taipei City

Energy Technology Data Exchange (ETDEWEB)

Hsieh, Chun-Ming; Aramaki, Toshiya; Hanaki, Keisuke [The University of Tokyo, Bunkyo-ku, Tokyo (Japan). Department of Urban Engineering

2007-09-15

The main work in the research focuses on the analysis and mitigation of the anthropogenic heat discharged from buildings, which is one of the main reasons leading to the heat island effect. The residential and commercial buildings, divided into 10 categories, with HVAC systems were analyzed by the building energy program, EnergyPlus. With the help of GIS, the heat rejection of all the residential and commercial buildings in DaAn Ward of Taipei City were evaluated, in which the spatial data and diurnal variation of the heat rejection were described by 3-h time periods. Furthermore, the effect of mitigation strategies was discussed. The first strategy was to change the wall/roof material of building envelope. The second and third strategies, from the viewpoint of energy saving, were to change the temperature setting of air conditioners and to turn off the lighting and equipment when not in use. The fourth strategy was to use a better efficiency of the cooling systems. Finally, the evaluation of installing the water-cooled cooling system, which discharges heat in the form of sensible and latent heat, was also included. (author)

[Harm reduction strategy in tobacco control].

Science.gov (United States)

Gorini, Giuseppe

2011-01-01

Potentially reduced exposure products (PREPs), already sold in USA and in some European Countries, are low-nitrosamine cigarettes, low-nitrosamine smokeless tobacco (e.g., the Swedish Snus), cigarette-like products, and medicinal nicotine products. Even e-cigarette delivers nicotine. With the exception of snus and medicinal nicotine, studies on the health effects of PREPs have not been carried out, although some PREPs are already sold and promoted as products that effectively reduce health risks. Thus, a second disaster similar to that occurred for light cigarettes could happen in the next years. Only medicinal nicotine and snus could be valid candidates to become PREPs, even if they pose some significant health risks. The World Health Organization, following a precautionary approach, has recently published a list of 9 carcinogens or toxicants recommended for mandated lowering (the tobacco-specific nitrosamines NNN and NNK, acetaldehyde, acrolein, benzene, benzo[a]pyrene, 1-3 butadiene, carbon monoxide, formaldehyde), and 9 carcinogens or toxicants for monitoring in usual cigarettes (not PREPs), underlining that tobacco companies cannot use this reduction strategy as a promotional message, as it occurred for light cigarettes in the 70s and 80s. The present status quo, in which cigarettes are freely available, medicinal nicotine, being a drug, is available under a regulated market, and Snus is prohibited, actually denies smokers the right to choose safer nicotine products. The solution suggested by the UK Royal College of Physicians is to balance the nicotine market, framing tobacco products and medicinal nicotine in the same regulation system; establishing a nicotine and tobacco regulatory authority;making medicinal nicotine more available; evaluating the feasibility of the introduction in the English market of Swedish Snus. California Government remarks that the nicotine maintenance is not a valid strategy, because it could induce smokers not to try to quit

Heat island effect on the quality of life in the city; Hitte-eilandeffect zet leefbaarheid in de stad verder onder druk

Energy Technology Data Exchange (ETDEWEB)

Van Harmelen, T.; Klok, L.; Doepp, S.; Dolevo, R.; Janssen, S. [Business Unit Milieu en Leefomgeving, TNO Bouw en Ondergrond, Delft (Netherlands)

2008-12-15

The global rise in temperature as a result of climate change becomes increasingly perceptible. The health effects of these changes, combined with air quality, are extra high in urban areas. It seems worth while to examine the consequences of increasing heat in urban areas in the Netherlands. In order to deal with the consequences in a responsible manner and to prepare for an even warmer future, answers will have to be found for the following two questions: (1) How large is the heat island effect in Dutch cities an what can we expect in the future?; and (2) What are the consequences of the heat island effect that we will have to take into account? [mk]. [Dutch] De mondiale temperatuurstijging ten gevolge van klimaatverandering is ook in Nederland steeds duidelijker waarneembaar. De gezondheidseffecten van deze veranderingen in combinatie met luchtkwaliteit zijn in het stedelijk gebied extra groot. Het lijkt daarom de moeite waard om onderzoek te doen naar de gevolgen van toenemende hitte in stedelijke gebieden in Nederland. Om op verantwoorde wijze met de gevolgen om te gaan en om voorbereid te zijn op een nog warmere toekomst zullen antwoorden moeten worden gevonden op twee wagen: (1) Hoe groot is het hitte-eilandeffect in de Nederlandse stad nu en wat kunnen we verwachten in de toekomst?; en (2) Met welke gevolgen van het hitte-eilandeffect moeten we rekening houden?.

Impact of different strategies to control Plasmodium infection and anaemia on the island of Bioko (Equatorial Guinea

Directory of Open Access Journals (Sweden)

Roche Jesús

2006-02-01

Full Text Available Abstract Background On the island of Bioko (Equatorial Guinea, insecticide-treated nets (ITNs have been the main tool used to control malaria over the last 13 years. In 2004, started an indoor residual spraying (IRS campaign to control malaria. The purpose of this study is to asses the impact of the two control strategies on the island of Bioko (Equatorial Guinea, with regards to Plasmodium infection and anaemia in the children under five years of age. Methods Two transversal studies, the first one prior to the start of the IRS campaign and the second one year later. Sampling was carried out by stratified clusters. Malaria infection was measured by means of thick and thin film, and the packed cell volume (PCV percentage. Data related to ITN use and information regarding IRS were collected. The Pearson's chi-square and logistic regression statistical tests were used to calculate odds ratios (OR Results In the first survey, 168 children were sampled and 433 children in the second one. The prevalence of infection was 40% in 2004, and significantly lower at 21.7% in 2005. PCV was 41% and 39%, respectively. 58% of the children surveyed in 2004 and 44.3% in 2005 had slept under an ITN. 78% of the dwellings studied in 2005 had been sprayed. In the 2005 survey, sleeping without a mosquito net meant a risk of infection 3 times greater than sleeping protected with a net hanged correctly and with no holes (p Conclusion IRS and ITNs have proven to be effective control strategies on the island of Bioko. The choice of one or other strategy is, above all, a question of operational feasibility and availability of local resources.

Urban weather data and building models for the inclusion of the urban heat island effect in building performance simulation.

Science.gov (United States)

Palme, M; Inostroza, L; Villacreses, G; Lobato, A; Carrasco, C

2017-10-01

This data article presents files supporting calculation for urban heat island (UHI) inclusion in building performance simulation (BPS). Methodology is used in the research article "From urban climate to energy consumption. Enhancing building performance simulation by including the urban heat island effect" (Palme et al., 2017) [1]. In this research, a Geographical Information System (GIS) study is done in order to statistically represent the most important urban scenarios of four South-American cities (Guayaquil, Lima, Antofagasta and Valparaíso). Then, a Principal Component Analysis (PCA) is done to obtain reference Urban Tissues Categories (UTC) to be used in urban weather simulation. The urban weather files are generated by using the Urban Weather Generator (UWG) software (version 4.1 beta). Finally, BPS is run out with the Transient System Simulation (TRNSYS) software (version 17). In this data paper, four sets of data are presented: 1) PCA data (excel) to explain how to group different urban samples in representative UTC; 2) UWG data (text) to reproduce the Urban Weather Generation for the UTC used in the four cities (4 UTC in Lima, Guayaquil, Antofagasta and 5 UTC in Valparaíso); 3) weather data (text) with the resulting rural and urban weather; 4) BPS models (text) data containing the TRNSYS models (four building models).

Efficient reduction of graphene oxide film by low temperature heat treatment and its effect on electrical conductivity

Energy Technology Data Exchange (ETDEWEB)

Hu, Xuebing; Chen, Zheng [Jingdezhen Ceramic Institute, Jingdezhen (China). Key Lab. of Inorganic Membrane; Yu, Yun [Shanghai Institute of Ceramics, Shanghai (China). Key Lab. of Inorganic Coating Materials; Zhang, Xiaozhen; Wang, Yongqing; Zhou, Jianer [Jingdezhen Ceramic Institute, Jingdezhen (China). Dept. of Materials Engineering

2018-03-01

Graphene-based conductive films have already attracted great attention due to their unique and outstanding physical properties. In this work, in order to develop a novel, effective method to produce these films with good electrical conductivity, a simple and green method is reported to rapidly and effectively reduce graphene oxide film using a low temperature heat treatment. The reduction of graphene oxide film is verified by XRD, FT-IR and Raman spectroscopy. Compared with graphene oxide film, the obtained reduced graphene oxide film has better electrical conductivity and its sheet resistance decreases from 25.3 kΩ x sq{sup -1} to 3.3 kΩ x sq{sup -1} after the heat treatment from 160 to 230 C. The mechanism of thermal reduction of the graphene oxide film mainly results from the removal of the oxygen-containing functional groups and the structural changes. All these results indicate that the low temperature heat treatment is a suitable and effective method for the reduction of graphene oxide film.

A Remote Sensing-based Characterization of the Urban Heat Island and its Implications for Modeled Estimates of Urban Biogenic Carbon Fluxes in Boston, MA.

Science.gov (United States)

Wang, J.; Friedl, M. A.; Hutyra, L.; Hardiman, B. S.

2015-12-01

Urban land use occupies a small but critical proportion of global land area for the carbon cycle, and in the coming decades, urban land area is expected to nearly double. Conversion of natural land cover to urban land cover imposes myriad ecological effects, including increased land surface and air temperatures via the urban heat island effect. In this study, we characterize the seasonal and spatial characteristics of the urban heat island over Boston, MA and estimate its consequences on biogenic carbon fluxes with a remote sensing-based model. Using a 12-year time series of emissivity- and atmospherically-corrected land surface temperatures from Landsat TM and ETM+ imagery, we find a high degree of spatial heterogeneity and consistent seasonal patterns in the thermal properties of Boston, controlled mainly by variations in vegetative cover. Field measurements of surface air temperature across an urbanization gradient show season- and vegetation-dependent patterns consistent with those observed in the Landsat data. With a fused data set that combines surface air temperature, MODIS, and Landsat observations, we modify and run the Vegetation Photosynthesis and Respiration Model (VPRM) to explore 1) how elevated temperatures affect diurnal and seasonal patterns of hourly urban biogenic carbon fluxes in Massachusetts in 2013 and 2014 and 2) to what extent these fluxes follow spatial patterns found in the urban heat island. Model modifications simulate the ecological effects of urbanization, including empirical adjustments to reanalysis-driven air temperatures (up to 5 K) and ecosystem respiration reduced by impervious surface area. Model results reveal spatio-temporal patterns consistent with strong land use and vegetation cover controls on biogenic carbon fluxes, with non-trivial biogenic annual net ecosystem exchange occurring in urban and suburban areas (up to -2.5 MgC/ha/yr). We specifically consider the feedbacks between Boston's urban heat island and landscape

A Control Strategy for Flywheel Energy Storage System for Frequency Stability Improvement in Islanded Microgrid

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A. A. Khodadoost Arani

2017-03-01

Full Text Available The Micro-Grid (MG stability is a significant issue that must be maintained in all operational modes. Usually, two control strategies can be applied to MG; V/f control and PQ control strategies. MGs with V/f control strategy should have some Distributed Generators (DGs which have fast responses versus load changes. The Flywheel Energy Storage System (FESS has this characteristic. The FESS, which converts the mechanical energy to electrical form, can generate electrical power or absorb the additional power in power systems or MGs. In this paper, the FESS structure modeled in detail and two control strategies (V/f and PQ control are applied for this application. In addition, in order to improve the MG frequency and voltage stability, two complementary controllers are proposed for the V/f control strategy; conventional PI and Fuzzy Controllers. A typical low voltage network, including FESS is simulated for four distinct scenarios in the MATLAB/ Simulink environment. It is shown that fuzzy controller has better performance than conventional PI controller in islanded microgrid.

Heat shock proteins and survival strategies in congeneric land snails (Sphincterochila) from different habitats.

Science.gov (United States)

Mizrahi, Tal; Heller, Joseph; Goldenberg, Shoshana; Arad, Zeev

2012-09-01

Polmunate land snails are subject to stress conditions in their terrestrial habitat, and depend on a range of behavioural, physiological and biochemical adaptations for coping with problems of maintaining water, ionic and thermal balance. The involvement of the heat shock protein (HSP) machinery in land snails was demonstrated following short-term experimental aestivation and heat stress, suggesting that land snails use HSPs as part of their survival strategy. As climatic variation was found to be associated with HSP expression, we tested whether adaptation of land snails to different habitats affects HSP expression in two closely related Sphincterochila snail species, a desert species Sphincterochila zonata and a Mediterranean-type species Sphincterochila cariosa. Our study suggests that Sphincterochila species use HSPs as part of their survival strategy following desiccation and heat stress, and as part of the natural annual cycle of activity and aestivation. Our studies also indicate that adaptation to different habitats results in the development of distinct strategies of HSP expression in response to stress, namely the reduced expression of HSPs in the desert-inhabiting species. We suggest that these different strategies reflect the difference in heat and aridity encountered in the natural habitats, and that the desert species S. zonata relies on mechanisms and adaptations other than HSP induction thus avoiding the fitness consequences of continuous HSP upregulation.

Neoclassical islands on COMPASS-D

International Nuclear Information System (INIS)

Gates, D.A.; Lloyd, B.; Morris, A.W.; McArdle, G.; O'Brien, M.R.; Valovic, M.; Warrick, C.D.; Wilson, H.R.

1997-01-01

Neoclassical magnetic islands are observed to limit the achievable β in COMPASS-D low collisionality single null divertor tokamak plasmas with ITER-like geometry (R 0 = 0.56 m, B 0 1.2 T, I p = 120-180 kA, κ = 1.6, ε = 0.3). The limiting β is typically well below that expected from ideal instabilities with maximum βN in the range of 1.6 to 2.1. The plasma is heated with up to 1.8 MW of 60 GHz electron cyclotron resonance heating (ECRH) at the second harmonic with X mode polarization. The time history of the measured island width is compared with the predictions of neoclassical tearing mode theory, with good agreement between theory and experiment. The measured islands have a threshold width below which the mode will not grow. The density scaling of the point of onset of the measured instabilities is compared with two theories that predict a threshold island width for the onset of neoclassical tearing modes. Applied resonant helical error fields are used to induce islands in collisionality regimes wherein the neoclassical islands do not occur naturally, allowing the study of the behaviour of neoclassical tearing modes in this regime. The critical β for the onset of neoclassical tearing modes is seen to be ∼3 times higher in the naturally stable region. This observation is compared with the predictions of both threshold theories. A simple expression for the q scaling of the maximum achievable β N in the presence of neoclassical tearing modes is derived on the basis of the assumption of a maximum allowable island width. The predicted q scaling of this β limit is compared with data from a q scan, and the results are in good agreement. (author)

Programming voltage reduction in phase change memory cells with tungsten trioxide bottom heating layer/electrode

International Nuclear Information System (INIS)

Rao Feng; Song Zhitang; Gong Yuefeng; Wu Liangcai; Feng Songlin; Chen, Bomy

2008-01-01

A phase change memory cell with tungsten trioxide bottom heating layer/electrode is investigated. The crystalline tungsten trioxide heating layer promotes the temperature rise in the Ge 2 Sb 2 Te 5 layer which causes the reduction in the reset voltage compared to a conventional phase change memory cell. Theoretical thermal simulation and calculation for the reset process are applied to understand the thermal effect of the tungsten trioxide heating layer/electrode. The improvement in thermal efficiency of the PCM cell mainly originates from the low thermal conductivity of the crystalline tungsten trioxide material.

Global Obesity Study on Drivers for Weight Reduction Strategies

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Carola Grebitus

2015-01-01

Full Text Available Objective: To assess factors determining the reaction of individuals to the threats of overweight and obesity and to examine the interdependencies between weight-reducing strategies. Methods: Cross-country survey covering 19 countries and 13,155 interviews. Data were analysed using a bivariate probit model that allows simultaneously analysing two weight-reducing strategies. Results: Results show that weight-reducing strategies chosen are not independent from each other. Findings also reveal that different strategies are chosen by different population segments. Women are more likely to change their dietary patterns and less likely to become physically active after surpassing a weight threshold. In addition, the probability of a dietary change in case of overweight differs considerably between countries. The study also reveals that attitudes are an important factor for the strategy choice. Conclusions: It is vital for public health policies to understand determinants of citizens' engagement in weight reduction strategies once a certain threshold is reached. Thus, results can support the design of public health campaigns and programmes that aim to change community or national health behaviour trends taking into account, e.g., national differences.

The Urban Heat Island phenomenon modelling and analysis as an adaptation of Maghreb cities to climate change

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Ouali Kaoutar

2018-01-01

Full Text Available The modeling of the urban microclimate, in particular the phenomenon of the Urban Heat Island (UHI, is becoming increasingly essential for city planning and urban design. The phenomenon analysis is henceforth possible thanks to the increase in computational power, the link between simulation tools and urban databases, which allow to represent explicitly the characteristics of the urban microclimate and to better understand its effects, through the analysis and evaluation of the different impacts of the urban climatic or anthropogenic contributors (urban morphology, land use, building sites, albedo, …. However, the choice of the scaleof the study depends on a balance between the precision of the modeling, the capacities of calculation and the availability and reliability of the data.The UHI phenomenon has been the subject of several research studies in the European countries since the 2000s. Thispaper focuses mainly on the description of the phenomenon, the different methodsused to evaluate and modeled its impacts, using some approaches for mitigating these ones.The contribution aims to highlight the phenomenon of the UHI based on a bibliographic study of the latest research on this topic in Maghreb cities.The state of art focuses on the progress made during the last 15 years taking into account the UHI in the different strategies for adapting cities to climate change and for improving their resilience.

Strategic GHG reduction through the use of ground source heat pump technology

International Nuclear Information System (INIS)

Hanova, J; Dowlatabadi, H

2007-01-01

Higher energy prices and concern about climate change is drawing increasing attention to ground source heat pump (GSHP) systems. Their clear advantage lies in being able to provide heating using 25 to 30% of the energy consumed by even the most efficient conventional alternatives. Their drawback has been high capital costs and uncertainty about whether the emissions associated with the electric power used to energise the system has higher system-wide emissions than the highest-efficiency furnaces. This study delineates circumstances under which GSHP systems achieve net emission reductions, for different electricity generation methods, heat pump efficiencies, and heating loads. We illustrate the effect of relative fuel prices on annual operating savings using fuel prices in multiple countries. Annual operating savings determine how rapidly the technology achieves payback and then generates return on the initial capital investment. Finally, we highlight the least cost supply curve for using GSHP to reduce greenhouse gas emissions. Using the United States as a base reference case, this study explores the potential of GSHP in cold-climate countries worldwide

Multigas reduction strategy under climate stabilization target

Energy Technology Data Exchange (ETDEWEB)

Kurosawa, A. [Inst. of Applied Energy, Tokyo (Japan)

2005-07-01

Global warming can be mitigated through the abatement of carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF{sub 6}). This study argued that multiple gas reduction flexibility should be assessed when considering effective greenhouse gas (GHG) mitigation strategies. Emissions of non-CO{sub 2} GHGs were calculated endogenously using an integrated assessment model. Multigas reduction potential was measured in relation to long-term atmospheric temperature targets, and the effects on gas life as well as abatement timing uncertainty were considered in terms of cost and technological availability. The model consisted of 5 nodules which considered issues related to energy, climate, land use, macroeconomics, and environmental impacts. The time horizon of the model was 2000 to 2100. An economic utility maximization technology was used to consider global trade balances. Emissions of non-CO{sub 2} gases from specific sources was calculated by multiplying the emission factor and the endogenous parameters within the model. Results were presented for GHG emissions and concentrations in 2 simulation cases: (1) a no climate policy case (NCP); and (2) a transient temperature stabilization (TTS) case. Actions to reduce non-CO{sub 2} GHGs included activity level changes in production and consumption, and additional reductions in abatement costs without sector activity changes. Results of the study showed that reducing global dependency on fossil fuels was an effective way to reduce GHG effects from CO{sub 2}, CH{sub 4} and N{sub 2}O. Additional abatements to reduce N{sub 2}O emissions are required in the agricultural sector. Economic incentives and public outreach programs are needed to offset the high transaction costs of GHG mitigation strategies. It was concluded that both short-term and long-term policies are required to reduce GHG in all sectors. Multigas mitigation is needed to

Investigating the vertical dimension of Singapore's urban heat island through quadcopter platforms: an pilot study

Science.gov (United States)

Chow, Winston; Ho, Dawn

2016-04-01

In numerous cities, measurements of urban warmth in most urban heat island (UHI) studies are generally constrained towards surface or near-surface (quadcopter platforms to measure urban temperature profiles up to 100 m above ground level in Singapore, which is a rapidly urbanizing major tropical metropolis. Three different land use/land cover categories were sampled; a high-rise residential estate, a university campus, and an urban park/green-space. Sorties were flown repeatedly at four different times - sunrise, noon, sunset and midnight. Initial results indicate significant variations in intra-site stability and inversion development between the urban canopy and boundary layers. These profiles are also temporally dynamic, depending on the time of day and larger-scale weather conditions.

Microplastics pollution and reduction strategies

Institute of Scientific and Technical Information of China (English)

Wei-Min Wu; Jun Yang; Craig S.Criddle

2017-01-01

Microplastic particles smaller than 5 mm in size are of increasing concern,especially in aquatic environments,such as the ocean.Primary source is microbeads (＜ 1 mm) used in cosmetics and cleaning agents and fiber fragments from washing of clothes,and secondary source such as broken down plastic litter and debris.These particles are mostly made from polyethylene (PE),polypropylene (PP),polystyrene (PS),polyethylene terephthalate (PET) and polyesters.They are ingested by diverse marine fauna,including zooplanktons,mussel,oyster,shrimp,fish etc.and can enter human food chains via several pathways.Strategy for control of microplastics pollution should primarily focus on source reduction and subsequently on the development of cost-effective clean up and remediation technologies.Recent research results on biodegradation of plastics have revealed a potential for microbial biodegradation and bioremediation of plastic pollutants,such as PE,PS and PET under appropriate conditions.

A wedge strategy for mitigation of urban warming in future climate scenarios

Directory of Open Access Journals (Sweden)

L. Zhao

2017-07-01

Full Text Available Heat stress is one of the most severe climate threats to human society in a future warmer world. The situation is further exacerbated in urban areas by urban heat islands (UHIs. Because the majority of world's population is projected to live in cities, there is a pressing need to find effective solutions for the heat stress problem. We use a climate model to investigate the effectiveness of various urban heat mitigation strategies: cool roofs, street vegetation, green roofs, and reflective pavement. Our results show that by adopting highly reflective roofs, almost all the cities in the United States and southern Canada are transformed into white oases – cold islands caused by cool roofs at midday, with an average oasis effect of −3.4 K in the summer for the period 2071–2100, which offsets approximately 80 % of the greenhouse gas (GHG warming projected for the same period under the RCP4.5 scenario. A UHI mitigation wedge consisting of cool roofs, street vegetation, and reflective pavement has the potential to eliminate the daytime UHI plus the GHG warming.

Storm Damage Reduction Project Design for Wallops Island, Virginia, Version 1.01

Science.gov (United States)

2011-10-01

photograph. Figure 2-4 shows the erosion and storm damage to the Wallops Island Association Clubhouse at the north end of the island in May 1949. Figure 2...uncertainty in what future rates will be. By the Bruun rule (Bruun 1962), small changes in sea level can be expected to have dramatic effects on shoreline...known. What is clear is that the north end of Wallops Island is accreting. Therefore, more sand is being delivered to this area than is leaving. 9.2

Arsenic flux dependence of island nucleation on InAs(001)

International Nuclear Information System (INIS)

Grosse, Frank; Barvosa-Carter, William; Zinck, Jenna; Wheeler, Matthew; Gyure, Mark F.

2002-01-01

The initial stages of InAs(001) homoepitaxial growth are investigated using a combination of kinetic Monte Carlo simulations based on ab initio density functional theory and scanning tunneling microscopy. In the two dimensional island nucleation mode investigated, the island number density is found to decrease with increasing As. This behavior is explained by a suppression of the effective In-adatom density leading to a reduction in island nucleation. The relevant microscopic processes responsible for this reduction are identified

Divertor Heat Flux Reduction and Detachment in the National Spherical Torus eXperiment.

Science.gov (United States)

Soukhanovskii, Vsevolod

2007-11-01

Steady-state handling of the heat flux is a critical divertor issue for both the International Thermonuclear Experimental Reactor and spherical torus (ST) devices. Because of an inherently compact divertor, it was thought that ST-based devices might not be able to fully utilize radiative and dissipative divertor techniques based on induced power and momentum loss. However, initial experiments conducted in the National Spherical Torus Experiment in an open geometry horizontal carbon plate divertor using 0.8 MA 2-6 MW NBI-heated lower single null H-mode plasmas at the lower end of elongations κ=1.8-2.4 and triangularities δ=0.45-0.75 demonstrated that high divertor peak heat fluxes, up to 6-10 MW/ m^2, could be reduced by 50-75% using a high-recycling radiative divertor regime with D2 injection. Furthermore, similar reduction was obtained with a partially detached divertor (PDD) at high D2 injection rates, however, it was accompanied by an X-point MARFE that quickly led to confinement degradation. Another approach takes advantage of the ST relation between strong shaping and high performance, and utilizes the poloidal magnetic flux expansion in the divertor region. Up to 60 % reduction in divertor peak heat flux was achieved at similar levels of scrape-off layer power by varying plasma shaping and thereby increasing the outer strike point (OSP) poloidal flux expansion from 4-6 to 18-22. In recent experiments conducted in highly-shaped 1.0-1.2 MA 6 MW NBI heated H-mode plasmas with divertor D2 injection at rates up to 10^22 s-1, a PDD regime with OSP peak heat flux 0.5-1.5 MW/m^2 was obtained without noticeable confinement degradation. Calculations based on a two point scrape-off layer model with parameterized power and momentum losses show that the short parallel connection length at the OSP sets the upper limit on the radiative exhaust channel, and both the impurity radiation and large momentum sink achievable only at high divertor neutral pressures are required

Djibouti; Poverty Reduction Strategy Paper: Annual Progress Report

OpenAIRE

International Monetary Fund

2012-01-01

The modern economy of the Republic of Djibouti is based on rents directly or indirectly originating from the international port of Djibouti and from the country’s strategic position. The Poverty Reduction Strategy Paper discusses that the growth recorded over the last five years is essentially driven by the increase in foreign direct investment—but especially by the activities of the Port of Djibouti. The informal economy constitutes a major proportion of the economic activities of Djibouti a...

Reduction of carbon dioxide emissions by solar water heating systems and passive technologies in social housing

International Nuclear Information System (INIS)

Bessa, Vanessa M.T.; Prado, Racine T.A.

2015-01-01

Growing global concern regarding climate change motivates technological studies to minimize environmental impacts. In this context, solar water heating (SWH) systems are notably prominent in Brazil, primarily because of the abundance of solar energy in the country. However, SWH designs have not always been perfectly developed. In most projects, the installation option of the solar system only considers the electric power economy aspects and not the particular characteristics of each climatic zone. Thus, the primary objective of this paper is to assess the potential of carbon dioxide reduction with the use of SWH in comparison with electric showers in social housing in several Brazilian climatic zones. The Brazilian government authorities have created public policies to encourage the use of these technologies primarily among the low-income population. The results of this paper indicate that hot climactic regions demonstrate a low reduction of CO 2 emissions with SWH installations. Thus, solar radiation is not useful for water heating in those regions, but it does lead to a large fraction of household cooling loads, implying a demand for electrical energy for air conditioning or requiring the adoption of passive techniques to maintain indoor temperatures below threshold values. -- Graphical abstract: Display Omitted -- Highlights: •Brazil has created public policies to increase the use of solar water heating in social housing. •We have evaluated the potential for reduction of CO 2 emissions installing solar water heating. •We have found that the coldest regions have the greatest potential for reducing emissions. •Passive technologies for thermal comfort in hot climate households are more useful than solar water heating systems

Effects of the generator and evaporator temperature differences on a double absorption heat transformer—Different control strategies on utilizing heat sources

International Nuclear Information System (INIS)

Wang, Hanzhi; Li, Huashan; Bu, Xianbiao; Wang, Lingbao

2017-01-01

Highlights: • Effects of the GETD on the DAHT system performance are analyzed. • Three different configurations are compared in detail. • Suggestions on the heat source control strategies are given. - Abstract: The combination of the absorption heat transformer with renewable energy systems, like solar thermal systems, is raising more and more concern. In those combined systems the strategies on utilizing heat sources can affect system thermodynamic performance significantly. Therefore, this study presents a detailed analysis on the effect of the heat source temperature and different heat source flow patterns on the performance of a double absorption heat transformer (DAHT). A detailed comparative study is carried out to clarify the impact of the generator and evaporator temperature differences (GETD) on the coefficient of performance (COP), exergy efficient (ECOP), exergy destruction rates in the individual components and heat transfer areas needed for each component. The results show that the generator, condenser and absorber-evaporator are responsible for most of the exergy destruction rate in the DAHT system; the parallel-flow configuration (the generator temperature is equal to the evaporator temperature) performs better under the high gross temperature lift conditions; in the case of the counter-flow configuration (the generator temperature is relatively higher), better performance can be obtained in both the COP and ECOP under the proper heat source temperature (85 and 95 °C); the fair-flow configuration (higher temperature in the evaporator) is not recommended in this paper due to no advantages found in either thermodynamic performance or system size.

Effect of heating strategies on whey protein denaturation--Revisited by liquid chromatography quadrupole time-of-flight mass spectrometry.

Science.gov (United States)

Akkerman, M; Rauh, V M; Christensen, M; Johansen, L B; Hammershøj, M; Larsen, L B

2016-01-01

Previous standards in the area of effect of heat treatment processes on milk protein denaturation were based primarily on laboratory-scale analysis and determination of denaturation degrees by, for example, electrophoresis. In this study, whey protein denaturation was revisited by pilot-scale heating strategies and liquid chromatography quadrupole time-of-flight mass spectrometer (LC/MC Q-TOF) analysis. Skim milk was heat treated by the use of 3 heating strategies, namely plate heat exchanger (PHE), tubular heat exchanger (THE), and direct steam injection (DSI), under various heating temperatures (T) and holding times. The effect of heating strategy on the degree of denaturation of β-lactoglobulin and α-lactalbumin was determined using LC/MC Q-TOF of pH 4.5-soluble whey proteins. Furthermore, effect of heating strategy on the rennet-induced coagulation properties was studied by oscillatory rheometry. In addition, rennet-induced coagulation of heat-treated micellar casein concentrate subjected to PHE was studied. For skim milk, the whey protein denaturation increased significantly as T and holding time increased, regardless of heating method. High denaturation degrees were obtained for T >100°C using PHE and THE, whereas DSI resulted in significantly lower denaturation degrees, compared with PHE and THE. Rennet coagulation properties were impaired by increased T and holding time regardless of heating method, although DSI resulted in less impairment compared with PHE and THE. No significant difference was found between THE and PHE for effect on rennet coagulation time, whereas the curd firming rate was significantly larger for THE compared with PHE. Micellar casein concentrate possessed improved rennet coagulation properties compared with skim milk receiving equal heat treatment. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Urban weather data and building models for the inclusion of the urban heat island effect in building performance simulation

Directory of Open Access Journals (Sweden)

M. Palme

2017-10-01

Full Text Available This data article presents files supporting calculation for urban heat island (UHI inclusion in building performance simulation (BPS. Methodology is used in the research article “From urban climate to energy consumption. Enhancing building performance simulation by including the urban heat island effect” (Palme et al., 2017 [1]. In this research, a Geographical Information System (GIS study is done in order to statistically represent the most important urban scenarios of four South-American cities (Guayaquil, Lima, Antofagasta and Valparaíso. Then, a Principal Component Analysis (PCA is done to obtain reference Urban Tissues Categories (UTC to be used in urban weather simulation. The urban weather files are generated by using the Urban Weather Generator (UWG software (version 4.1 beta. Finally, BPS is run out with the Transient System Simulation (TRNSYS software (version 17. In this data paper, four sets of data are presented: 1 PCA data (excel to explain how to group different urban samples in representative UTC; 2 UWG data (text to reproduce the Urban Weather Generation for the UTC used in the four cities (4 UTC in Lima, Guayaquil, Antofagasta and 5 UTC in Valparaíso; 3 weather data (text with the resulting rural and urban weather; 4 BPS models (text data containing the TRNSYS models (four building models.

Generalized Scaling of Urban Heat Island Effect and Its Applications for Energy Consumption and Renewable Energy

Directory of Open Access Journals (Sweden)

T.-W. Lee

2014-01-01

Full Text Available In previous work from this laboratory, it has been found that the urban heat island intensity (UHI can be scaled with the urban length scale and the wind speed, through the time-dependent energy balance. The heating of the urban surfaces during the daytime sets the initial temperature, and this overheating is dissipated during the night-time through mean convection motion over the urban surface. This may appear to be in contrast to the classical work by Oke (1973. However, in this work, we show that if the population density is used in converting the population data into urbanized area, then a good agreement with the current theory is found. An additional parameter is the “urban flow parameter,” which depends on the urban building characteristics and affects the horizontal convection of heat due to wind. This scaling can be used to estimate the UHI intensity in any cities and therefore predict the required energy consumption during summer months. In addition, all urbanized surfaces are expected to exhibit this scaling, so that increase in the surface temperature in large energy-consumption or energy-producing facilities (e.g., solar electric or thermal power plants can be estimated.

Effects of Urbanization and Seasonal Cycle on the Surface Urban Heat Island Patterns in the Coastal Growing Cities: A Case Study of Casablanca, Morocco

Directory of Open Access Journals (Sweden)

Hicham Bahi

2016-10-01

Full Text Available The urban heat island (UHI phenomenon is a harmful environmental problem in urban areas affecting both climatic and ecological processes. This paper aims to highlight and monitor the spatial distribution of Surface UHI (SUHI in the Casablanca region, Morocco, using remote sensing data. To achieve this goal, a time series of Landsat TM/ETM+/OLI-TIRS images was acquired from 1984 to 2016 and analyzed. In addition, nocturnal MODIS images acquired from 2005 to 2015 were used to evaluate the nighttime SUHI. In order to better analyze intense heat produced by urban core, SUHI intensity (SUHII was computed by quantifying the difference of land surface temperature (LST between urban and rural areas. The urban core SUHII appears more significant in winter seasons than during summer, while the pattern of SUHII becomes moderate during intermediate seasons. During winter, the average daytime SUHII gradually increased in the residential area of Casablanca and in some small peri-urban cities by more than 1 °C from 1984 to 2015. The industrial areas of the Casablanca region were affected by a significant rise in SUHII exceeding 15 °C in certain industrial localities. In contrast, daytime SUHII shows a reciprocal effect during summer with emergence of a heat island in rural areas and development of cool islands in urban and peri-urban areas. During nighttime, the SUHII remains positive in urban areas year-round with higher values in winter as compared to summer. The results point out that the seasonal cycle of daytime SUHII as observed in the Casablanca region is different from other mid-latitude cities, where the highest values are often observed in summer during the day.

Ground source heat pumps designed for earth-sheltered, low-energy atrium building

NARCIS (Netherlands)

Pawlovski, A.; Heim, D.; Hensen, J.L.M.

2003-01-01

One of the main strategies in design of earth-sheltered buildings is to reduce heat losses in the winter and heat gains in the summer by using the relatively stable thermal conditions of the soil. Additionally, construction work carried out at the site allows a reduction of the installation costs

Low-cost risk reduction strategy for small workplaces: how can we spread good practices?

Science.gov (United States)

Kogi, K

2006-01-01

Recent advances in health risk reduction approaches are examined based on inter-country networking experiences. A noteworthy progress is the wider application of low-cost improvements to risk reduction particularly in small enterprises and agriculture in both industrially developing and developed countries. This is helped by the readiness of managers and workers to implement these improvements despite many constraints. Typical improvements include mobile racks, simple workstation changes, screening hazards, better welfare facilities and teamwork arrangements. In view of the complex circumstances of work-related health risks, it is important to know whether a low-cost strategy can advance risk reduction practices effectively and what support measures are necessary. It is confirmed that the strategy can overcome related constraints through its advantages. Main advantages lie in (a) the facilitation of improved practices in multiple technical areas, (b) the strengthening of realistic stepwise risk reduction, and (c) the enhanced multiplier effects through training of local trainers. Action-oriented risk assessment tools, such as action checklists and low-cost improvement guides, can encourage risk-reducing measures adjusted to each local situation. It is suggested to spread the low-cost risk reduction strategy for improving small workplaces in diversified settings with the support of these locally tailored tools.

Learning Agent for a Heat-Pump Thermostat with a Set-Back Strategy Using Model-Free Reinforcement Learning

Directory of Open Access Journals (Sweden)

Frederik Ruelens

2015-08-01

Full Text Available The conventional control paradigm for a heat pump with a less efficient auxiliary heating element is to keep its temperature set point constant during the day. This constant temperature set point ensures that the heat pump operates in its more efficient heat-pump mode and minimizes the risk of activating the less efficient auxiliary heating element. As an alternative to a constant set-point strategy, this paper proposes a learning agent for a thermostat with a set-back strategy. This set-back strategy relaxes the set-point temperature during convenient moments, e.g., when the occupants are not at home. Finding an optimal set-back strategy requires solving a sequential decision-making process under uncertainty, which presents two challenges. The first challenge is that for most residential buildings, a description of the thermal characteristics of the building is unavailable and challenging to obtain. The second challenge is that the relevant information on the state, i.e., the building envelope, cannot be measured by the learning agent. In order to overcome these two challenges, our paper proposes an auto-encoder coupled with a batch reinforcement learning technique. The proposed approach is validated for two building types with different thermal characteristics for heating in the winter and cooling in the summer. The simulation results indicate that the proposed learning agent can reduce the energy consumption by 4%–9% during 100 winter days and by 9%–11% during 80 summer days compared to the conventional constant set-point strategy.

Review on Microwave-Matter Interaction Fundamentals and Efficient Microwave-Associated Heating Strategies

Science.gov (United States)

Sun, Jing; Wang, Wenlong; Yue, Qinyan

2016-01-01

Microwave heating is rapidly emerging as an effective and efficient tool in various technological and scientific fields. A comprehensive understanding of the fundamentals of microwave–matter interactions is the precondition for better utilization of microwave technology. However, microwave heating is usually only known as dielectric heating, and the contribution of the magnetic field component of microwaves is often ignored, which, in fact, contributes greatly to microwave heating of some aqueous electrolyte solutions, magnetic dielectric materials and certain conductive powder materials, etc. This paper focuses on this point and presents a careful review of microwave heating mechanisms in a comprehensive manner. Moreover, in addition to the acknowledged conventional microwave heating mechanisms, the special interaction mechanisms between microwave and metal-based materials are attracting increasing interest for a variety of metallurgical, plasma and discharge applications, and therefore are reviewed particularly regarding the aspects of the reflection, heating and discharge effects. Finally, several distinct strategies to improve microwave energy utilization efficiencies are proposed and discussed with the aim of tackling the energy-efficiency-related issues arising from the application of microwave heating. This work can present a strategic guideline for the developed understanding and utilization of the microwave heating technology. PMID:28773355

Monitoring Urban Heat Island Through Google Earth Engine: Potentialities and Difficulties in Different Cities of the United States

Science.gov (United States)

Ravanelli, R.; Nascetti, A.; Cirigliano, R. V.; Di Rico, C.; Monti, P.; Crespi, M.

2018-04-01

The aim of this work is to exploit the large-scale analysis capabilities of the innovative Google Earth Engine platform in order to investigate the temporal variations of the Urban Heat Island phenomenon as a whole. A intuitive methodology implementing a largescale correlation analysis between the Land Surface Temperature and Land Cover alterations was thus developed.The results obtained for the Phoenix MA are promising and show how the urbanization heavily affects the magnitude of the UHI effects with significant increases in LST. The proposed methodology is therefore able to efficiently monitor the UHI phenomenon.

Comparison of image quality in head CT studies with different dose-reduction strategies

DEFF Research Database (Denmark)

Johansen, Jeppe; Nielsen, Rikke; Fink-Jensen, Vibeke

The number of multi-detector CT examinations is increasing rapidly. They allow high quality reformatted images providing accurate and precise diagnosis at maximum speed. Brain examinations are the most commonly requested studies, and although they come at a lower effective dose than body CT, can...... account to a considerable radiation dose as many patients undergo repeated studies. Therefore, various dose-reduction strategies are applied such as automated tube current and voltage modulation and recently different iterative reconstruction algorithms. However, the trade-off of all dose......-reduction maneuvers is reduction of image quality due to image noise or artifacts. The aim of our study was therefore to find the best diagnostic images with lowest possible dose. We present results of dose- and image quality optimizing strategies of brain CT examinations at our institution. We compare sequential...

A comprehensive approach for the simulation of the Urban Heat Island effect with the WRF/SLUCM modeling system: The case of Athens (Greece)

Science.gov (United States)

Giannaros, Christos; Nenes, Athanasios; Giannaros, Theodore M.; Kourtidis, Konstantinos; Melas, Dimitrios

2018-03-01

This study presents a comprehensive modeling approach for simulating the spatiotemporal distribution of urban air temperatures with a modeling system that includes the Weather Research and Forecasting (WRF) model and the Single-Layer Urban Canopy Model (SLUCM) with a modified treatment of the impervious surface temperature. The model was applied to simulate a 3-day summer heat wave event over the city of Athens, Greece. The simulation, using default SLUCM parameters, is capable of capturing the observed diurnal variation of urban temperatures and the Urban Heat Island (UHI) in the greater Athens Area (GAA), albeit with systematic biases that are prominent during nighttime hours. These biases are particularly evident over low-intensity residential areas, and they are associated with the surface and urban canopy properties representing the urban environment. A series of sensitivity simulations unravels the importance of the sub-grid urban fraction parameter, surface albedo, and street canyon geometry in the overall causation and development of the UHI effect. The sensitivities are then used to determine optimal values of the street canyon geometry, which reproduces the observed temperatures throughout the simulation domain. The optimal parameters, apart from considerably improving model performance (reductions in mean temperature bias from 0.30 °C to 1.58 °C), are also consistent with actual city building characteristics - which gives confidence that the model set-up is robust, and can be used to study the UHI in the GAA in the anticipated warmer conditions in the future.

Implementing exertional heat illness prevention strategies in US high school football.

Science.gov (United States)

Kerr, Zachary Y; Marshall, Stephen W; Comstock, R Dawn; Casa, Douglas J

2014-01-01

Approximately 6500 high school football athletes are treated annually for exertional heat illness (EHI). In 2009, the National Athletic Trainers Association (NATA)-led Inter-Association Task Force (NATA-IATF) released preseason heat acclimatization guidelines to help athletes become accustomed to environmental factors contributing to EHI. This study examines compliance with NATA-IATF guidelines and related EHI prevention strategies. The study used a cross-sectional survey completed by 1142 certified athletic trainers (AT), which captured compliance with 17 NATA-IATF guidelines and EHI prevention strategies in high school football during the 2011 preseason. On average, AT reported football programs complying with 10.4 NATA-IATF guidelines (SD = 3.2); 29 AT (2.5%) reported compliance with all 17. Guidelines with the lowest compliance were as follows: "Single-practice days consisted of practice no more than three hours in length" (39.7%); and "During days 3-5 of acclimatization, only helmets and shoulder pads should be worn" (39.0%). An average of 7.6 EHI prevention strategies (SD = 2.5) were used. Common EHI prevention strategies were as follows: having ice bags/cooler available (98.5%) and having a policy with written instructions for initiating emergency medical service response (87.8%). Programs in states with mandated guidelines had higher levels of compliance with guidelines and greater prevalence of EHI prevention strategies. A low proportion of surveyed high school football programs fully complied with all 17 NATA-IATF guidelines. However, many EHI prevention strategies were voluntarily implemented. State-level mandated EHI prevention guidelines may increase compliance with recognized best practices recommendations. Ongoing longitudinal monitoring of compliance is also recommended.

Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

DEFF Research Database (Denmark)

Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas

2010-01-01

During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading...... of heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank-Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males...... from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature 1 degrees C), and during whole...

Multiple models guide strategies for agricultural nutrient reductions

Science.gov (United States)

Scavia, Donald; Kalcic, Margaret; Muenich, Rebecca Logsdon; Read, Jennifer; Aloysius, Noel; Bertani, Isabella; Boles, Chelsie; Confesor, Remegio; DePinto, Joseph; Gildow, Marie; Martin, Jay; Redder, Todd; Robertson, Dale M.; Sowa, Scott P.; Wang, Yu-Chen; Yen, Haw

2017-01-01

In response to degraded water quality, federal policy makers in the US and Canada called for a 40% reduction in phosphorus (P) loads to Lake Erie, and state and provincial policy makers in the Great Lakes region set a load-reduction target for the year 2025. Here, we configured five separate SWAT (US Department of Agriculture's Soil and Water Assessment Tool) models to assess load reduction strategies for the agriculturally dominated Maumee River watershed, the largest P source contributing to toxic algal blooms in Lake Erie. Although several potential pathways may achieve the target loads, our results show that any successful pathway will require large-scale implementation of multiple practices. For example, one successful pathway involved targeting 50% of row cropland that has the highest P loss in the watershed with a combination of three practices: subsurface application of P fertilizers, planting cereal rye as a winter cover crop, and installing buffer strips. Achieving these levels of implementation will require local, state/provincial, and federal agencies to collaborate with the private sector to set shared implementation goals and to demand innovation and honest assessments of water quality-related programs, policies, and partnerships.

The Three Mile Island Disaster.

Science.gov (United States)

Crosby, Emeral

1980-01-01

For the past decade, education has been experiencing meltdown, explosions, radiation leaks, heat pollution, and management crises, just like the Three Mile Island disaster. This article offers suggestions on how to deal with these problems. (Author/LD)

A new structure of permeable pavement for mitigating urban heat island.

Science.gov (United States)

Liu, Yong; Li, Tian; Peng, Hangyu

2018-09-01

The urban heat island (UHI) effect has been a great threat to human habitation, and how to mitigate this problem has been a global concern over decades. This paper addresses the cooling effect of a novel permeable pavement called evaporation-enhancing permeable pavement, which has capillary columns in aggregate and a liner at the bottom. To explore the efficiency of mitigating the UHI, bench-scale permeable pavement units with capillary columns were developed and compared with conventional permeable pavement. Criteria of capillary capacities of the column, evaporation rates, and surface temperature of the pavements were monitored under simulated rainfall and Shanghai local weather conditions. Results show the capillary column was important in increasing evaporation by lifting water from the bottom to the surface, and the evaporation-enhancing permeable pavement was cooler than a conventional permeable pavement by as much as 9.4°C during the experimental period. Moreover, the cooling effect of the former pavement could persist more than seven days under the condition of no further rainfall. Statistical analysis result reveals that evaporation-enhancing permeable pavement can mitigate the UHI effect significantly more than a conventional permeable pavement. Copyright © 2018 Elsevier B.V. All rights reserved.

Health Impacts of Climate Change in Pacific Island Countries: A Regional Assessment of Vulnerabilities and Adaptation Priorities.

Science.gov (United States)

McIver, Lachlan; Kim, Rokho; Woodward, Alistair; Hales, Simon; Spickett, Jeffery; Katscherian, Dianne; Hashizume, Masahiro; Honda, Yasushi; Kim, Ho; Iddings, Steven; Naicker, Jyotishma; Bambrick, Hilary; McMichael, Anthony J; Ebi, Kristie L

2016-11-01

Between 2010 and 2012, the World Health Organization Division of Pacific Technical Support led a regional climate change and health vulnerability assessment and adaptation planning project, in collaboration with health sector partners, in 13 Pacific island countries-Cook Islands, Federated States of Micronesia, Fiji, Kiribati, Marshall Islands, Nauru, Niue, Palau, Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu. We assessed the vulnerabilities of Pacific island countries to the health impacts of climate change and planned adaptation strategies to minimize such threats to health. This assessment involved a combination of quantitative and qualitative techniques. The former included descriptive epidemiology, time series analyses, Poisson regression, and spatial modeling of climate and climate-sensitive disease data, in the few instances where this was possible; the latter included wide stakeholder consultations, iterative consensus building, and expert opinion. Vulnerabilities were ranked using a "likelihood versus impact" matrix, and adaptation strategies were prioritized and planned accordingly. The highest-priority climate-sensitive health risks in Pacific island countries included trauma from extreme weather events, heat-related illnesses, compromised safety and security of water and food, vector-borne diseases, zoonoses, respiratory illnesses, psychosocial ill-health, non-communicable diseases, population pressures, and health system deficiencies. Adaptation strategies relating to these climate change and health risks could be clustered according to categories common to many countries in the Pacific region. Pacific island countries are among the most vulnerable in the world to the health impacts of climate change. This vulnerability is a function of their unique geographic, demographic, and socioeconomic characteristics combined with their exposure to changing weather patterns associated with climate change, the health risks entailed, and the limited capacity

The urban heat island of a city in an arid zone: the case of Eilat, Israel

Science.gov (United States)

Sofer, M.; Potchter, O.

2006-05-01

This study presents the results of a preliminary research that was conducted in the city of Eilat, located in an extreme hot and arid zone on the northern coast of the Red Sea. The purpose was to analyse the characteristics of the local urban heat island (UHI). Diurnal pre-dawn and early-afternoon measurements were taken in winter and summer weather conditions on three separate occasions for two consecutive years. The results show the development of a moderate UHI located around the most intensive area of human activity; the city business centre and dense hotel belt. The UHI is more significant at midday during the summer period, while early morning inversions in winter have a weakening effect on the UHI intensity. It was found that the topography and wind regime have a dominant effect on the location and intensity of the UHI, while the sea has a very marginal effect. Due to the UHI influences on the spatial distribution of the heat stress in the city, it is suggested that further applied UHI research should be focused on the summer period.

Model-based comparison of strategies for reduction of stormwater micropollutant emissions

DEFF Research Database (Denmark)

Vezzaro, Luca; Sharma, Anitha Kumari; Mikkelsen, Peter Steen

to improve the recipient quality by reducing the fluxes of heavy metals (copper, zinc) and organic compounds (fluoranthene) to natural waters. MP sources were identified by using GIS land usage data. When comparing the different control strategies, the integrated model showed the greater benefits......Strategies for reduction of micropollutant (MP) emissions from stormwater systems require the comparison of different scenarios including source control, end-of-pipe treatment, or their combination. Dynamic integrated models can be important tools for this comparison, as they can integrate...... the limited data provided by monitoring campaigns and evaluate the performance of different strategies based on model simulation results. This study presents an example where an integrated dynamic model, in combination with stormwater quality measurements, was used to evaluate 6 different strategies...

Analysis of Successful Strategy to Develop Sustainable Marine Ecotourism in Gili Bawean Island, Gresik, East Java

Science.gov (United States)

Wardani, M. P.; Fahrudin, A.; Yulianda, F.

2017-10-01

The sustainability of resources and marine ecotourism in Gili Bawean Island is still developing to the current day. The management is conducted individualistically and is currently far away from being integrated and sustainable. It is important that stakeholders understand the island’s condition and the urgency of coastal resources, to determine collective action, which leads to sustainable ecotourism on the island. This research aimed to discover stakeholders’ involvement in determining key variables and formulate a strategy of marine ecotourism development based on possible future scenarios in Gili Bawean Island, Gresik Regency, East Java. The field study was done through an expert meeting of stakeholder representatives on March-April 2017. The data was analyzed using Participatory Prospective Analysis (PPA), a comprehensive and quick framework, which was designed to demand requests in structural anticipation and exploration and also to focus on interaction and consensus among stakeholders. The results of this research show that five main variables should be emphasized in developing marine ecotourism on the island, including tourist activities, institutions, and economic activities, as well as the quality of human and natural resources. Counting heavily on those variables, it is hoped to create an integrated marine ecotourism development. Coordination among stakeholders can be declared successful when the tourist objects are managed better, and the quality of tourist destinations and the number of tourist visits increase noticeably. Good governance of marine ecotourism contributes to increments in tourist amenities, boosts the welfare of local communities, and secures sustainability of local natural resources.

Carbon Emissions Trading and Combined Heat and Power Strategies: Unintended Consequences

Science.gov (United States)

Tysseling, John C.; Vosevich, Mary; Boersma, Benjamin R.; Zumwalt, Jefferey A.

2009-01-01

Facility professionals continuously search for projects that reduce energy consumption and operating costs so as to directly benefit their bottom line. Many institutions nationwide have contemplated or made investments in combined heat and power (CHP) projects as a life-cycle strategy to minimize operating costs. However, recent sustainability and…

The Impact of Urban Growth and Climate Change on Heat Stress in an Australian City

Science.gov (United States)

Chapman, S.; Mcalpine, C. A.; Thatcher, M. J.; Salazar, A.; Watson, J. R.

2017-12-01

Over half of the world's population lives in urban areas. Most people will therefore be exposed to climate change in an urban environment. One of the climate risks facing urban residents is heat stress, which can lead to illness and death. Urban residents are at increased risk of heat stress due to the urban heat island effect. The urban heat island is a modification of the urban environment and increases temperatures on average by 2°C, though the increase can be much higher, up to 8°C when wind speeds and cloud cover are low. The urban heat island is also expected to increase in the future due to urban growth and intensification, further exacerbating urban heat stress. Climate change alters the urban heat island due to changes in weather (wind speed and cloudiness) and evapotranspiration. Future urban heat stress will therefore be affected by urban growth and climate change. The aim of this study was to examine the impact of urban growth and climate change on the urban heat island and heat stress in Brisbane, Australia. We used CCAM, the conformal cubic atmospheric model developed by the CSIRO, to examine temperatures in Brisbane using scenarios of urban growth and climate change. We downscaled the urban climate using CCAM, based on bias corrected Sea Surface Temperatures from the ACCESS1.0 projection of future climate. We used Representative Concentration Pathway (RCP) 8.5 for the periods 1990 - 2000, 2049 - 2060 and 2089 - 2090 with current land use and an urban growth scenario. The present day climatology was verified using weather station data from the Australian Bureau of Meteorology. We compared the urban heat island of the present day with the urban heat island with climate change to determine if climate change altered the heat island. We also calculated heat stress using wet-bulb globe temperature and apparent temperature for the climate change and base case scenarios. We found the urban growth scenario increased present day temperatures by 0.5°C in the

Reduction of seismic response in breeder plants

International Nuclear Information System (INIS)

Tajirian, F.F.; Somes, N.F.; Todeschini, R.A.

1984-01-01

Thin-walled vessels to be used in the Nuclear Steam Supply Systems (NSSS) of future LMFBR's will be more sensitive to seismic excitation than their equivalents used in conventional LWR plants. Optimization studies of building arrangement have indicated that embedment of future plants may be one feasible strategy for reducing seismic response. This paper presents the results of a three-dimensional soil-structure interaction analysis using the computer program SASSI. Two types of embedded buildings are considered: full embedment of the nuclear island, and embedment of the reactor cavity alone. A comparison, between the response of the embedded structure with that of a plant supported on the surface, indicates that the seismic response at the reactor vessel support ledge can be lowered by embedment of either the entire nuclear island or the reactor cavity alone. This reduction is larger when the plant is embedded in a softer site due to the increased effect of soil-structure interaction

Missing the target: including perspectives of women with overweight and obesity to inform stigma-reduction strategies.

Science.gov (United States)

Puhl, R M; Himmelstein, M S; Gorin, A A; Suh, Y J

2017-03-01

Pervasive weight stigma and discrimination have led to ongoing calls for efforts to reduce this bias. Despite increasing research on stigma-reduction strategies, perspectives of individuals who have experienced weight stigma have rarely been included to inform this research. The present study conducted a systematic examination of women with high body weight to assess their perspectives about a broad range of strategies to reduce weight-based stigma. Women with overweight or obesity ( N  = 461) completed an online survey in which they evaluated the importance, feasibility and potential impact of 35 stigma-reduction strategies in diverse settings. Participants (91.5% who reported experiencing weight stigma) also completed self-report measures assessing experienced and internalized weight stigma. Most participants assigned high importance to all stigma-reduction strategies, with school-based and healthcare approaches accruing the highest ratings. Adding weight stigma to existing anti-harassment workplace training was rated as the most impactful and feasible strategy. The family environment was viewed as an important intervention target, regardless of participants' experienced or internalized stigma. These findings underscore the importance of including people with stigmatized identities in stigma-reduction research; their insights provide a necessary and valuable contribution that can inform ways to reduce weight-based inequities and prioritize such efforts.

Agricultural diversification strategies in small island states

NARCIS (Netherlands)

Drori, I.; Gayle, D. J.

1991-01-01

Across the small island states of the Caribbean, the need for greater agricultural diversification is a constant policy concern, as exemplified by the case of Barbados. Although the cane sugar industry in Barbados remains one of the more cost-efficient in the world, the structures of both the

HOUSEHOLD HEATING IN THE LIGHT OF CLIMATE CHANGE

Directory of Open Access Journals (Sweden)

MÓNIKA PALÁDI

2014-12-01

Full Text Available Greenhouse gas emissions resulting from anthropogenic activities play a significant role in climate change. The residential heating should be mentioned one of the main polluting source of greenhouse gases.This paper aims to give a comprehensive view about the amount of CO2 emission as well as objectives and strategies for reduction the GHG emission. In addition, we illustrate the example of an average Hungarian family house (100 m2 , that biomass-based energy production what extent can reduce the current very high degree carbon dioxide emissions. We prepared investment analysis, as to what kind of ecological and economic benefits may result in heating modernization projects of a four-member family home. Additionally, a calculation method of CO2 emission from heating is demonstrated on the basis of IPPC report (2006; the role of biomass is explained in heating; furthermore I give an overview analysis about the significance of forests for reduction of CO2 concentration.

Genetic determinants of heat resistance in Escherichia coli

Directory of Open Access Journals (Sweden)

Ryan eMercer

2015-09-01

Full Text Available Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR. This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli.

Maximising the recovery of low grade heat: An integrated heat integration framework incorporating heat pump intervention for simple and complex factories

International Nuclear Information System (INIS)

Miah, J.H.; Griffiths, A.; McNeill, R.; Poonaji, I.; Martin, R.; Leiser, A.; Morse, S.; Yang, A.; Sadhukhan, J.

2015-01-01

period of about 5 years. In comparison, conventional direct and/or indirect heat integration without heat pumps showed an energy reduction potential of only 3.7–4.3%. Despite the long payback, the role of heat pumps combined with an integrated search by direct and indirect heat exchange from zonal to factory level can provide the maximum heat recovery. The framework has the potential to be applied across the process manufacturing community to inform longer-term energy integration strategies.

Least cost planning for CO2-reduction strategies

International Nuclear Information System (INIS)

Seifritz, W.

1990-01-01

A first recommendation for the determination of the minimum costs for a carbon-dioxide reduction strategy is presented. For this, the tabulation of so-called, 'CO 2 -ranking-lists', containing the relationship between the costs of a distinct measure to avoid the emission of certain amount of CO 2 (in dollar/t CO 2 ) versus its potential (in t CO 2 /yr), is indispensable. Some basic aspects of this approach are discussed and a first guess of the costs of some measures to avoid CO 2 -emissions into the atmosphere is presented. (orig.) [de

Comparison of Direct Solar Energy to Resistance Heating for Carbothermal Reduction of Regolith

Science.gov (United States)

Muscatello, Anthony C.; Gustafson, Robert J.

2011-01-01

A comparison of two methods of delivering thermal energy to regolith for the carbo thermal reduction process has been performed. The comparison concludes that electrical resistance heating is superior to direct solar energy via solar concentrators for the following reasons: (1) the resistance heating method can process approximately 12 times as much regolith using the same amount of thermal energy as the direct solar energy method because of superior thermal insulation; (2) the resistance heating method is more adaptable to nearer-term robotic exploration precursor missions because it does not require a solar concentrator system; (3) crucible-based methods are more easily adapted to separation of iron metal and glass by-products than direct solar energy because the melt can be poured directly after processing instead of being remelted; and (4) even with projected improvements in the mass of solar concentrators, projected photovoltaic system masses are expected to be even lower.

Energy management strategies for combined heat and electric power micro-grid

Directory of Open Access Journals (Sweden)

Barbarić Marina

2016-01-01

Full Text Available The increasing energy production from variable renewable energy sources such as wind and solar has resulted in several challenges related to the system reliability and efficiency. In order to ensure the supply-demand balance under the conditions of higher variability the micro-grid concept of active distribution networks arising as a promising one. However, to achieve all the potential benefits that micro-gird concept offer, it is important to determine optimal operating strategies for micro-grids. The present paper compares three energy management strategies, aimed at ensuring economical micro-grid operation, to find a compromise between the complexity of strategy and its efficiency. The first strategy combines optimization technique and an additional rule while the second strategy is based on the pure optimization approach. The third strategy uses model based predictive control scheme to take into account uncertainties in renewable generation and energy consumption. In order to compare the strategies with respect to cost effectiveness, a residential micro-grid comprising photovoltaic modules, thermal energy storage system, thermal loads, electrical loads as well as combined heat and power plant, is considered.

Strategies to Reduce the Harmful Effects of Extreme Heat Events: A Four-City Study

Directory of Open Access Journals (Sweden)

Jalonne L. White-Newsome

2014-02-01

Full Text Available Extreme heat events (EHEs are becoming more intense, more frequent and longer lasting in the 21st century. These events can disproportionately impact the health of low-income, minority, and urban populations. To better understand heat-related intervention strategies used by four U.S. cities, we conducted 73 semi-structured interviews with government and non-governmental organization leaders representing public health, general social services, emergency management, meteorology, and the environmental planning sectors in Detroit, MI; New York City, NY; Philadelphia, PA and Phoenix, AZ—cities selected for their diverse demographics, climates, and climate adaptation strategies. We identified activities these leaders used to reduce the harmful effects of heat for residents in their city, as well as the obstacles they faced and the approaches they used to evaluate these efforts. Local leaders provided a description of how local context (e.g., climate, governance and city structure impacted heat preparedness. Despite the differences among study cities, political will and resource access were critical to driving heat-health related programming. Upon completion of our interviews, we convened leaders in each city to discuss these findings and their ongoing efforts through day-long workshops. Our findings and the recommendations that emerged from these workshops could inform other local or national efforts towards preventing heat-related morbidity and mortality.

A study of the Oklahoma City urban heat island using ground measurements and remote sensing

Energy Technology Data Exchange (ETDEWEB)

Brown, M. J. (Michael J.); Ivey, A. (Austin); McPherson, T. N. (Timothy N.); Boswell, D. (David); Pardyjak, E. R. (Eric R.)

2004-01-01

Measurements of temperature and position were collected during the night from an instrumented van on routes through Oklahoma City and the rural outskirts. The measurements were taken as part of the Joint URBAN 2003 Tracer Field Experiment conducted in Oklahoma City from June 29, 2003 to July 30, 2003 (Allwine et al., 2004). The instrumented van was driven over four primary routes that included legs from the downtown core to four different 'rural' areas. Each route went through residential areas and most often went by a line of permanently fixed temperature probes (Allwine et al., 2004) for cross-checking purposes. Each route took from 20 to 40 minutes to complete. Based on seven nights of data, initial analyses indicate that there was a temperature difference of 0.5-6.5 C between the urban core and nearby 'rural' areas. Analyses also suggest that there were significant fine scale temperature differences over distances of tens of meters within the city and in the nearby rural areas. The temperature measurements that were collected are intended to supplement the meteorological measurements taken during the Joint URBAN 2003 Field Experiment, to assess the importance of the urban heat island phenomenon in Oklahoma City, and to test new urban canopy parameterizations that have been developed for regional scale meteorological codes (e.g., Chin et al., 2000; Holt and Shi, 2004). In addition to the ground measurements, skin temperature measurements were also analyzed from remotely sensed images taken from the Earth Observing System's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). A surface kinetic temperature thermal infrared image captured by the ASTER of the Oklahoma City area on July 21, 2001 was analyzed within ESRI's ArcGIS 8.3 to correlate variations in temperature with land use type. Analysis of this imagery suggests distinct variations in temperature across different land use categories. Through the use of

A Satellite-Derived Climatological Analysis of Urban Heat Island over Shanghai during 2000–2013

Directory of Open Access Journals (Sweden)

Weijiao Huang

2017-06-01

Full Text Available The urban heat island is generally conducted based on ground observations of air temperature and remotely sensing of land surface temperature (LST. Satellite remotely sensed LST has the advantages of global coverage and consistent periodicity, which overcomes the weakness of ground observations related to sparse distributions and costs. For human related studies and urban climatology, canopy layer urban heat island (CUHI based on air temperatures is extremely important. This study has employed remote sensing methodology to produce monthly CUHI climatology maps during the period 2000–2013, revealing the spatiotemporal characteristics of daytime and nighttime CUHI during this period of rapid urbanization in Shanghai. Using stepwise linear regression, daytime and nighttime air temperatures at the four overpass times of Terra/Aqua were estimated based on time series of Terra/Aqua-MODIS LST and other auxiliary variables including enhanced vegetation index, normalized difference water index, solar zenith angle and distance to coast. The validation results indicate that the models produced an accuracy of 1.6–2.6 °C RMSE for the four overpass times of Terra/Aqua. The models based on Terra LST showed higher accuracy than those based on Aqua LST, and nighttime air temperature estimation had higher accuracy than daytime. The seasonal analysis shows daytime CUHI is strongest in summer and weakest in winter, while nighttime CUHI is weakest in summer and strongest in autumn. The annual mean daytime CUHI during 2000–2013 is 1.0 and 2.2 °C for Terra and Aqua overpass, respectively. The annual mean nighttime CUHI is about 1.0 °C for both Terra and Aqua overpass. The resultant CUHI climatology maps provide a spatiotemporal quantification of CUHI with emphasis on temperature gradients. This study has provided information of relevance to urban planners and environmental managers for assessing and monitoring urban thermal environments which are constantly

Background information on a multimedia nitrogen emission reduction strategy; Hintergrundpapier zu einer multimedialen Stickstoffemissionsminderungsstrategie

Energy Technology Data Exchange (ETDEWEB)

Geupel; Jering; Frey (and others)

2009-04-15

The background information report on a multimedia nitrogen reduction strategy covers the following chapters: 1. Introduction: the nitrogen cascade and the anthropogenic influence, environmental impact of increased nitrogen emissions and effects on human health. 2. Sources and balancing of anthropogenic nitrogen emissions in Germany. 3. Environmental quality targets, activity goals of environmental measures and instruments of an integrated nitrogen reduction strategy. 4. Conclusions and perspectives. The attachments include emission sources, nitrogen release and nitrogen transport in Germany; catalogue of measures and instruments according the criteria efficiency and cost-efficacy.

Strategy to control the invasive alien tree Miconia calvescens in Pacific islands: Eradication, containment or something else?

Science.gov (United States)

Meyer, Jean-Yves; Loope, Lloyd; Goarant, Anne-Claire; Veitch, C.R.; Clout, M.N.; Towns, D. R.

2011-01-01

Miconia calvescens (Melastomataceae) is a notorious plant invader in the tropical islands of French Polynesia, Hawaii and New Caledonia. A small tree native to Central and South America, it was first introduced as an ornamental in private botanic gardens in Tahiti (1937), Honolulu (1961), and Nouméa (1970s) where it escaped, became naturalised, and formed dense monospecific stands. More than 80,000 ha are currently invaded in French Polynesia, 10,000 ha in the Hawaiian Islands and 140 ha in New Caledonia. Control programmes have been under way in the Hawaiian Islands (Oahu, Maui, Hawaii, Kauai) and French Polynesia (Raiatea, Tahaa, Nuku Hiva, Fatu Hiva) since the early 1990s, and in New Caledonia (Province Sud) since 2006. Despite more than 15 years of intensive control efforts and millions of plants destroyed, eradication has not been achieved in any of these islands, mainly because the species has multiple features that thwart its elimination (e.g., prolific seed production, active dispersal by alien and native frugivorous birds, large and persistent soil seed bank, shade-tolerance), combined with the difficulty of detecting and destroying plants on rough terrain and steep slopes, insufficient control frequency, and limited financial and human resources. Miconia’s life cycle requires at least four years growth from seedling to fruiting. Consequently, prevention of fruit production may be an effective management strategy for small populations. This “juvenilization” process may allow the eradication of small populations when carefully conducted over a quarter century. 

Fast uncertainty reduction strategies relying on Gaussian process models

International Nuclear Information System (INIS)

Chevalier, Clement

2013-01-01

This work deals with sequential and batch-sequential evaluation strategies of real-valued functions under limited evaluation budget, using Gaussian process models. Optimal Stepwise Uncertainty Reduction (SUR) strategies are investigated for two different problems, motivated by real test cases in nuclear safety. First we consider the problem of identifying the excursion set above a given threshold T of a real-valued function f. Then we study the question of finding the set of 'safe controlled configurations', i.e. the set of controlled inputs where the function remains below T, whatever the value of some others non-controlled inputs. New SUR strategies are presented, together with efficient procedures and formulas to compute and use them in real world applications. The use of fast formulas to recalculate quickly the posterior mean or covariance function of a Gaussian process (referred to as the 'kriging update formulas') does not only provide substantial computational savings. It is also one of the key tools to derive closed form formulas enabling a practical use of computationally-intensive sampling strategies. A contribution in batch-sequential optimization (with the multi-points Expected Improvement) is also presented. (author)

Technological significances to reduce the material problems. Feasibility of heat flux reduction

International Nuclear Information System (INIS)

Yamazaki, Seiichiro; Shimada, Michiya.

1994-01-01

For a divertor plate in a fusion power reactor, a high temperature coolant must be used for heat removal to keep thermal efficiency high. It makes the temperature and thermal stress of wall materials higher than the design limits. Issues of the coolant itself, e.g. burnout of high temperature water, will also become a serious problem. Sputtering erosion of the surface material will be a great concern of its lifetime. Therefore, it is necessary to reduce the heat and particle loads to the divertor plate technologically. The feasibility of some technological methods of heat reduction, such as separatrix sweeping, is discussed. As one of the most promising ideas, the methods of radiative cooling of the divertor plasma are summarized based on the recent results of large tokamaks. The feasibility of remote radiative cooling and gas divertor is discussed. The ideas are considered in recent design studies of tokamak power reactors and experimental reactors. By way of example, conceptual designs of divertor plate for the steady state tokamak power reactor are described. (author)

Assessing the effect of wind speed/direction changes on urban heat island intensity of Istanbul.

Science.gov (United States)

Perim Temizoz, Huriye; Unal, Yurdanur S.

2017-04-01

Assessing the effect of wind speed/direction changes on urban heat island intensity of Istanbul. Perim Temizöz, Deniz H. Diren, Cemre Yürük and Yurdanur S. Ünal Istanbul Technical University, Department of Meteorological Engineering, Maslak, Istanbul, Turkey City or metropolitan areas are significantly warmer than the outlying rural areas since the urban fabrics and artificial surfaces which have different radiative, thermal and aerodynamic features alter the surface energy balance, interact with the regional circulation and introduce anthropogenic sensible heat and moisture into the atmosphere. The temperature contrast between urban and rural areas is most prominent during nighttime since heat is absorbed by day and emitted by night. The intensity of the urban heat island (UHI) vary considerably depending on the prevailent meteorological conditions and the characteristics of the region. Even though urban areas cover a small fraction of Earth, their climate has greater impact on the world's population. Over half of the world population lives in the cities and it is expected to rise within the coming decades. Today almost one fifth of the Turkey's population resides in Istanbul with the percentage expected to increase due to the greater job opportunities compared to the other cities. Its population has been increased from 2 millions to 14 millions since 1960s. Eventually, the city has been expanded tremendously within the last half century, shifting the landscape from vegetation to built up areas. The observations of the last fifty years over Istanbul show that the UHI is most pronounced during summer season. The seasonal temperature differences between urban and suburban sites reach up to 3 K and roughly haft degree increase in UHI intensity is observed after 2000. In this study, we explore the possible range of heat load and distribution over Istanbul for different prevailing wind conditions by using the non-hydrostatic MUKLIMO3 model developed by DWD

Key Parameters for Urban Heat Island Assessment in A Mediterranean Context: A Sensitivity Analysis Using the Urban Weather Generator Model

Science.gov (United States)

Salvati, Agnese; Palme, Massimo; Inostroza, Luis

2017-10-01

Although Urban Heat Island (UHI) is a fundamental effect modifying the urban climate, being widely studied, the relative weight of the parameters involved in its generation is still not clear. This paper investigates the hierarchy of importance of eight parameters responsible for UHI intensity in the Mediterranean context. Sensitivity analyses have been carried out using the Urban Weather Generator model, considering the range of variability of: 1) city radius, 2) urban morphology, 3) tree coverage, 4) anthropogenic heat from vehicles, 5) building’s cooling set point, 6) heat released to canyon from HVAC systems, 7) wall construction properties and 8) albedo of vertical and horizontal surfaces. Results show a clear hierarchy of significance among the considered parameters; the urban morphology is the most important variable, causing a relative change up to 120% of the annual average UHI intensity in the Mediterranean context. The impact of anthropogenic sources of heat such as cooling systems and vehicles is also significant. These results suggest that urban morphology parameters can be used as descriptors of the climatic performance of different urban areas, easing the work of urban planners and designers in understanding a complex physical phenomenon, such as the UHI.

Epidemiologic survey of feline leukemia virus in domestic cats on Tsushima Island, Japan: management strategy for Tsushima leopard cats.

Science.gov (United States)

Makundi, Isaac; Koshida, Yushi; Kuse, Kyohei; Hiratsuka, Takahiro; Ito, Jumpei; Baba, Takuya; Watanabe, Shinya; Kawamura, Maki; Odahara, Yuka; Miyake, Ariko; Yamamoto, Hanae; Kuniyoshi, Sawako; Onuma, Manabu; Nishigaki, Kazuo

2017-11-01

The Tsushima leopard cat (TLC) Prionailurus bengalensis euptilurus, a subspecies of P. bengalensis, is designated a National Natural Monument of Japan, and lives only on Tsushima Island, Nagasaki Prefecture, Japan. TLCs are threatened by various infectious diseases. Feline leukemia virus (FeLV) causes a serious infectious disease with a poor prognosis in cats. Therefore, the transmission of FeLV from Tsushima domestic cats (TDCs) to TLCs may threaten the TLC population. We investigated the FeLV infection status of both TDCs and TLCs on Tsushima Island by screening blood samples for FeLV p27 antigen and using PCR to amplify the full-length FeLV env gene. The prevalence of FeLV was 6.4% in TDCs and 0% in TLCs. We also demonstrated that the virus can replicate in the cells of TLCs, suggesting its potential cross-species transmission. The viruses in TDCs were classified as genotype I/clade 3, which is prevalent on a nearby island, based on previous studies of FeLV genotypes and FeLV epidemiology. The FeLV viruses identified on Tsushima Island can be further divided into 2 lineages within genotype I/clade 3, which are geographically separated in Kamijima and Shimojima, indicating that FeLV may have been transmitted to Tsushima Island at least twice. Monitoring FeLV infection in the TDC and TLC populations is highly recommended as part of the TLC surveillance and management strategy.

Standardized Elemental Basis for Gas-Turbine Engine Heat Exchangers is the Key Factor for Their Cost Reduction

Institute of Scientific and Technical Information of China (English)

Soudarev A.V; Soudarev B.V; Kondratiev V.V; Lazarev M.V

2001-01-01

The competitiveness of the small gas turbine units (GTUs) (Ne＜300 kW) in the world power market is dependent on both the maintenance expenses and the capital costs of production. Reduction in the maintenance expenditures could be achieved by increasing the plant efficiency. This task could be solved by some methods: increasing the cycle inlet temperature TIT, getting the cycle more complex (use of heat regeneration and compressed air intermediate cooling), cutting the power consumption on heat-stressed parts cooling. Putting the above into effect is linked with introduction of novel structural materials, a sharp increase in the mass-size values and the plant manufacture expenditures, in particular, at provision of its self-regulation.In connection with the above, the development of the combined metal-ceramic airheaters and standardization of the elemental basis of the metal gas-gas heat exchangers will promote reduction in the expenditures of the maintenance and the manufacture of the small-size independent power GTEs.

Assessment of self-efficacy to employ self-initiated pornography use-reduction strategies.

Science.gov (United States)

Kraus, Shane W; Rosenberg, Harold; Tompsett, Carolyn J

2015-01-01

This study evaluated several psychometric properties of a newly developed questionnaire designed to assess individuals' self-efficacy (from 0% to 100%) to employ self-initiated cognitive-behavioral strategies intended to reduce the frequency and duration of their pornography use. Using a web-based data collection procedure, we recruited 1298 male users of pornography to complete questionnaires assessing hypersexuality, pornography use history, and general self-efficacy. Based on a principal component analysis and examination of inter-item correlations, we deleted 13 items from the initial pool of 21 strategies. The resulting 8-item questionnaire had excellent internal consistency reliability, and a moderate mean inter-item correlation considered indicative of unidimensionality. In support of criterion validity, self-efficacy to employ use-reduction strategies was significantly associated with the frequency with which participants used pornography, with scores on a measure of hypersexuality, and with the number of times one had attempted to cut back using pornography. In support of discriminant validity, we found that pornography use-reduction self-efficacy scores were not strongly correlated with general self-efficacy. Both researchers and clinicians could use this questionnaire to assess pornography users' confidence to employ self-initiated strategies intended to reduce the duration and frequency with which they use pornography. Published by Elsevier Ltd.

Optimization of a Gas Switching Combustion process through advanced heat management strategies

International Nuclear Information System (INIS)

Cloete, Schalk; Zaabout, Abdelghafour; Romano, Matteo C.; Chiesa, Paolo; Lozza, Giovanni; Gallucci, Fausto; Sint Annaland, Martin van; Amini, Shahriar

2017-01-01

Highlights: • GSC is a promising new reactor concept for power production with cost effective CO 2 capture. • The standalone fluidized bed reactors employed will allow for easy process scale-up. • The GSC simple configuration achieves higher efficiencies than conventional solutions. • Further increases in efficiency can be achieved via advanced heat management. • The 41.9% maximum efficiency is in line with other CLC–IGCC configurations. - Abstract: Gas Switching Combustion (GSC) is a promising new process concept for energy efficient power production with integrated CO 2 capture. In comparison to conventional Chemical Looping Combustion (CLC) carried out in interconnected fluidized beds, the GSC concept will be substantially easier to design and scale up, especially for pressurized conditions. One potential drawback of the GSC concept is the gradual temperature variation over the transient process cycle, which leads to a drop in electric efficiency of the plant. This article investigates heat management strategies to mitigate this issue both through simulations and experiments. Simulation studies of the GSC concept integrated into an IGCC power plant show that heat management using a nitrogen recycle stream can increase plant efficiency by 3 percentage points to 41.6% while maintaining CO 2 capture ratios close to 90%. Reactive multiphase flow simulations of the GSC reactor also showed that heat management can eliminate fuel slip problems. In addition, the GSC concept offers the potential to remove the need for a nitrogen recycle stream by implementing a concentrated air injection that extracts heat while only a small percentage of oxygen reacts. Experiments have shown that, similar to nitrogen recycle, this strategy reduces transient temperature variations across the cycle and therefore merits further investigation.

Determinants of underage college student drinking: implications for four major alcohol reduction strategies.

Science.gov (United States)

Paek, Hye-Jin; Hove, Thomas

2012-01-01

Guided by the assumptions of the social ecological model and the social marketing approach, this study provides a simultaneous and comprehensive assessment of 4 major alcohol reduction strategies for college campuses: school education programs, social norms campaigns, alcohol counter-marketing, and alcohol control policies. Analysis of nationally representative secondary survey data among 5,472 underage students reveals that alcohol marketing seems to be the most formidable risk factor for underage drinking, followed by perceived drinking norms (injunctive norm) and lax policy enforcement. This analysis suggests that, to make social norms campaigns and alcohol control policies more effective, alcohol reduction strategies should be developed to counter the powerful influence of alcohol marketing and promotions.

Control principles for blackstart and island operation of microgrid

Energy Technology Data Exchange (ETDEWEB)

Laaksonen, H.; Kauhaniemi, K. (University of Vaasa (Finland))

2008-07-01

In some unexpected situations a microgrid may become unstable after transition to islanded mode and all DG units must be disconnected from microgrid. In case of these events a restoration strategy for microgrid blackstart is needed. Also if the islanded microgrid is divided into different protection zones in case of a fault, fault management strategy with capability of very fast operation is needed to maintain stability in the healthy section of the islanded microgrid. The control of microgrid voltage and frequency during the microgrid blackstart is not possible without energy storage unit. In this paper sequence of actions for the microgrid blackstart operation as well as control principles of some DG units during blackstart are defined and simulated with two different microgrid configurations. Also one simulation case considering fault management strategy and control principles during fault in islanded microgrid is presented. Based on the simulations dimensioning principles for the needed energy storage and size of simultaneously controlled loads can be drawn. (orig.)

Dominica; Poverty Reduction Strategy Paper: Joint Staff Advisory Note

OpenAIRE

International Monetary Fund

2006-01-01

The Growth and Social Protection Strategy (GSPS) attaches great importance to the promotion of economic growth and job creation, given the nature of poverty in Dominica. The GSPS also stresses that existing health and education programs are essential to foster growth in the medium and long terms, but further efforts are needed. The GSPS contains a macroeconomic framework that is consistent with the proposed objectives of poverty reduction. The growth and fiscal targets envisaged in the macroe...

Republic of Armenia; Poverty Reduction Strategy Paper Progress Report

OpenAIRE

International Monetary Fund

2006-01-01

This paper evaluates Armenia’s Poverty Reduction Strategy Paper (PRSP) Progress Report covering August 2003–December 2004. The developments in 2003–04 are rather reassuring. The resulting pattern, overall, is more favorable than what was foreseen by the PRSP development scenario. Particularly, the economy grew twice as rapidly as the projected rate, and the government continues to implement a public expenditure policy that is focused on social sectors and infrastructure development. As a resu...

Case study: Bioremediation in the Aleutian Islands

International Nuclear Information System (INIS)

Steward, K.J.; Laford, H.D.

1995-01-01

This case study describes the design, construction, and operation of a bioremediation pile on Adak Island, which is located in the Aleutian Island chain. Approximately 1,900 m 3 of petroleum-contaminated soil were placed in the bioremediation pile. The natural bioremediation process was enhanced by an oxygen and nutrient addition system to stimulate microbial activity. Despite the harsh weather on the island, after the first 6 months of operation, laboratory analyses of soil samples indicated a significant (80%) reduction in diesel concentrations

District heating marketing. Strategies in the heating market. 2. ed.; Fernwaerme-Marketing. Strategien im Waermemarkt

Energy Technology Data Exchange (ETDEWEB)

Marschalleck, Helmut [MVV Energie AG, Mannheim (Germany); Arndt, Andreas [EnBW Vertriebs- und Servicegesellschaft, Karlsruhe (Germany); Behm, Norman [Stadtwerke Rostock AG (Germany)] [and others

2012-07-01

The assistance in the strategic and operational planning of an individual marketing strategy in the district heating market is the focus of the book under consideration. Starting from the definition of the actual situation (market analysis and marketing potential) and the strategic goal, a marketing concept and a marketing mix (product policy, pricing policy, distribution policy as well as communication policy) is established. Subsequently, the tools of the marketing controlling (incoming orders and turnover, marketing key performance indicators, reporting, marketing audit) are described.

Comparative Effectiveness of Personalized Lifestyle Management Strategies for Cardiovascular Disease Risk Reduction.

Science.gov (United States)

Chu, Paula; Pandya, Ankur; Salomon, Joshua A; Goldie, Sue J; Hunink, M G Myriam

2016-03-29

Evidence shows that healthy diet, exercise, smoking interventions, and stress reduction reduce cardiovascular disease risk. We aimed to compare the effectiveness of these lifestyle interventions for individual risk profiles and determine their rank order in reducing 10-year cardiovascular disease risk. We computed risks using the American College of Cardiology/American Heart Association Pooled Cohort Equations for a variety of individual profiles. Using published literature on risk factor reductions through diverse lifestyle interventions-group therapy for stopping smoking, Mediterranean diet, aerobic exercise (walking), and yoga-we calculated the risk reduction through each of these interventions to determine the strategy associated with the maximum benefit for each profile. Sensitivity analyses were conducted to test the robustness of the results. In the base-case analysis, yoga was associated with the largest 10-year cardiovascular disease risk reductions (maximum absolute reduction 16.7% for the highest-risk individuals). Walking generally ranked second (max 11.4%), followed by Mediterranean diet (max 9.2%), and group therapy for smoking (max 1.6%). If the individual was a current smoker and successfully quit smoking (ie, achieved complete smoking cessation), then stopping smoking yielded the largest reduction. Probabilistic and 1-way sensitivity analysis confirmed the demonstrated trend. This study reports the comparative effectiveness of several forms of lifestyle modifications and found smoking cessation and yoga to be the most effective forms of cardiovascular disease prevention. Future research should focus on patient adherence to personalized therapies, cost-effectiveness of these strategies, and the potential for enhanced benefit when interventions are performed simultaneously rather than as single measures. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Upstream-Downstream Joint Carbon Reduction Strategies Based on Low-Carbon Promotion

Directory of Open Access Journals (Sweden)

Xiqiang Xia

2018-06-01

Full Text Available A differential game model is established to analyze the impact of emissions reduction efforts and low-carbon product promotion on the reduction strategies of low-carbon product manufacturers (subsequently referred to as manufacturers and the retailers of such products in a dynamic environment. Based on this model, changes in emissions reduction efforts and promotional efforts are comparatively analyzed under three scenarios (retailers bearing the promotional cost, manufacturers bearing the promotional cost, and centralized decision-making. The results are as follows: (1 the trajectory of carbon emissions reduction per product unit is the highest when the supply chain is under centralized decision-making, followed by when manufacturers bear the promotional cost, and lastly when retailers bear the cost; (2 when manufacturers bear the promotional cost, the market demand, emissions reduction effort, and promotional effort are higher, although the unit retail price is higher than when retailers bear the promotional cost; and (3 under centralized decision-making, the unit retail price is the lowest; however, sales volume, the emissions reduction effort, and the promotional effort are all higher than those in the other scenarios.

Modeling nitrate-nitrogen load reduction strategies for the Des Moines River, Iowa using SWAT.

Science.gov (United States)

Schilling, Keith E; Wolter, Calvin F

2009-10-01

The Des Moines River that drains a watershed of 16,175 km(2) in portions of Iowa and Minnesota is impaired for nitrate-nitrogen (nitrate) due to concentrations that exceed regulatory limits for public water supplies. The Soil Water Assessment Tool (SWAT) model was used to model streamflow and nitrate loads and evaluate a suite of basin-wide changes and targeting configurations to potentially reduce nitrate loads in the river. The SWAT model comprised 173 subbasins and 2,516 hydrologic response units and included point and nonpoint nitrogen sources. The model was calibrated for an 11-year period and three basin-wide and four targeting strategies were evaluated. Results indicated that nonpoint sources accounted for 95% of the total nitrate export. Reduction in fertilizer applications from 170 to 50 kg/ha achieved the 38% reduction in nitrate loads, exceeding the 34% reduction required. In terms of targeting, the most efficient load reductions occurred when fertilizer applications were reduced in subbasins nearest the watershed outlet. The greatest load reduction for the area of land treated was associated with reducing loads from 55 subbasins with the highest nitrate loads, achieving a 14% reduction in nitrate loads achieved by reducing applications on 30% of the land area. SWAT model results provide much needed guidance on how to begin implementing load reduction strategies most efficiently in the Des Moines River watershed.

Measures against heat stress in the city of Gelsenkirchen, Germany

Directory of Open Access Journals (Sweden)

Dütemeyer, Dirk

2014-04-01

Full Text Available In the near-surface atmosphere, heat waves during the summer cause situations that may lead to human-biometeorological impairment. Because of their high population density, overheated cities are particularly strongly affected by heat stress. In the future, due to the effects of climate change, heat stress will increase in terms of its intensity and spatial expansion in the areas of concern. Taking the example of the city of Gelsenkirchen, Germany, this article presents a method for the identification of areas requiring adaptation or protection. A scenario of the future increase of heat stress events is presented, based on data of the German climate change model STAR II. For the identification of areas requiring adaptation and protection, spatial analyses of the urban heat island, land use and demographic aspects were performed using GIS tools. The application and assessment of adaptation measures is investigated for an urban quarter using the microscale numerical model ENVI-met. Finally adaptation measures in urban planning against heat stress are discussed. The relevant urban planning adaptation measures, which are also important in view of climate change, not only involve heat stress reduction in the residential areas already affected, but also involve the protection and optimisation of existing favourable and compensation areas.

Solid waste management on small islands. The case of Green Island, Taiwan

Energy Technology Data Exchange (ETDEWEB)

Chen, M.C.; Ruijs, A.; Wesseler, J. [Environmental Economics and Natural Resources Group, Wageningen University, P.O. Box 8130, 6700 EW Wageningen (Netherlands)

2005-09-01

Municipalities of small islands have limited capacities for waste disposal. In the case of Green Island, Taiwan, continuing with business as usual would only allow the disposal of waste on the island for another 8 years. Three alternatives for solid waste management (SWM) are compared. The cost-effective solution is the one, which is the most expensive in the short run: continuing business as usual and introducing an incineration plant in the year 2010. The results indicate furthermore that deviations from optimal timing of investment only slightly change average annual costs. In the long run, the municipality can hardly avoid transporting waste to the mainland. By investing in an incineration plant, they can buy additional time to investigate alternative SWM strategies.

A dynamic model for assessing the effects of management strategies on the reduction of construction and demolition waste

International Nuclear Information System (INIS)

Yuan Hongping; Chini, Abdol R.; Lu Yujie; Shen Liyin

2012-01-01

Highlights: ► We proposes a model for projecting C and D waste reduction of construction projects. ► The model can simulate effects of various management strategies on waste reduction. ► The model integrates all essential variables that affect C and D waste reduction. ► By using the model, best strategies could be identified before being implemented. - Abstract: During the past few decades, construction and demolition (C and D) waste has received increasing attention from construction practitioners and researchers worldwide. A plethora of research regarding C and D waste management has been published in various academic journals. However, it has been determined that existing studies with respect to C and D waste reduction are mainly carried out from a static perspective, without considering the dynamic and interdependent nature of the whole waste reduction system. This might lead to misunderstanding about the actual effect of implementing any waste reduction strategies. Therefore, this research proposes a model that can serve as a decision support tool for projecting C and D waste reduction in line with the waste management situation of a given construction project, and more importantly, as a platform for simulating effects of various management strategies on C and D waste reduction. The research is conducted using system dynamics methodology, which is a systematic approach that deals with the complexity – interrelationships and dynamics – of any social, economic and managerial system. The dynamic model integrates major variables that affect C and D waste reduction. In this paper, seven causal loop diagrams that can deepen understanding about the feedback relationships underlying C and D waste reduction system are firstly presented. Then a stock-flow diagram is formulated by using software for system dynamics modeling. Finally, a case study is used to illustrate the validation and application of the proposed model. Results of the case study not only

Carbon Reduction Strategies Based on an NW Small-World Network with a Progressive Carbon Tax

Directory of Open Access Journals (Sweden)

Bin Wu

2017-09-01

Full Text Available There is an increasingly urgent need to reduce carbon emissions. Devising effective carbon tax policies has become an important research topic. It is necessary to explore carbon reduction strategies based on the design of carbon tax elements. In this study, we explore the effect of a progressive carbon tax policy on carbon emission reductions using the logical deduction method. We apply experience-weighted attraction learning theory to construct an evolutionary game model for enterprises with different levels of energy consumption in an NW small-world network, and study their strategy choices when faced with a progressive carbon tax policy. The findings suggest that enterprises that adopt other energy consumption strategies gradually transform to a low energy consumption strategy, and that this trend eventually spreads to the entire system. With other conditions unchanged, the rate at which enterprises change to a low energy consumption strategy becomes faster as the discount coefficient, the network externality, and the expected adjustment factor increase. Conversely, the rate of change slows as the cost of converting to a low energy consumption strategy increases.

Effect of Heat Accumulation on Femtosecond Laser Reductive Sintering of Mixed CuO/NiO Nanoparticles

Directory of Open Access Journals (Sweden)

Mizue Mizoshiri

2018-05-01

Full Text Available Direct laser-writing techniques have attracted attention for their use in two- and three-dimensional printing technologies. In this article, we report on a micropatterning process that uses femtosecond laser reductive sintering of mixed CuO/NiO nanoparticles. The writing speed, laser fluence, and incident total energy were varied to investigate the influence of heat accumulation on the micropatterns formed by these materials. Heat accumulation and the thermal history of the laser irradiation process significantly affected the material composition and the thermoelectric properties of the fabricated micropatterns. Short laser irradiation durations and high laser fluences decrease the amount of metal oxide in the micropatterns. Selective fabrication of p-type and n-type thermoelectric micropatterns was demonstrated to be possible with control of the reduction and reoxidization reactions through the control of writing speed and total irradiation energy.

A new district heating system in the city of Bolanzo

DEFF Research Database (Denmark)

Mazzocato, Alessandro; Li, Hongwei; Marchiori, S.

2014-01-01

In the context of the EU project “Sinfonia”, that aims to reduce Bolzano’s primary energy consumption up to 40%, SEL AG, an Italian energy company is planning to extend the existing district heating and cooling (DHC) network and explore strategies to improve efficiency, environmental, and economic...... performance. This research aims to assess the potential energy saving of temperature and peak heating load reduction in the Bolzano’s DHC network. Historical performance data from district heating (DH) users were collected and residential building were classified based on construction year and energy...

Effect of heating strategy on power consumption and performance of a pilot plant anaerobic digester.

Science.gov (United States)

Espinosa-Solares, Teodoro; Valle-Guadarrama, Salvador; Bombardiere, John; Domaschko, Max; Easter, Michael

2009-05-01

The effect of heating strategy on power consumption and performance of a pilot plant anaerobic digester treating chicken litter, under thermophilic conditions, has been studied. Heating strategy was evaluated using three different spans (0.2 degrees C, 0.6 degrees C, and 1.0 degree C) for triggering the temperature control system from target temperature (56.7 degrees C). The hydraulic retention time in the pilot plant digester was in the range of 32 to 37 days, varying the total solids concentration fed from 5% to 6%. The results showed that under the experimental conditions, heating was the most energy-demanding process with 95.5% of the energy used. Increments up to 7.5% and 3.8%, respectively, on mechanical and heating power consumption, were observed as the span, for triggering the temperature control system from target temperature, was increased. Under the experimental conditions studied here, an increment of 30.6% on the global biodigester performance index was observed when a span of 1.0 degree C was compared to the one of 0.2 degrees C.

Numerical investigation of the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir: a case study of the Daming geothermal field in China.

Science.gov (United States)

Guo, Xuyang; Song, Hongqing; Killough, John; Du, Li; Sun, Pengguang

2018-02-01

The utilization of geothermal energy is clean and has great potential worldwide, and it is important to utilize geothermal energy in a sustainable manner. Mathematical modeling studies of geothermal reservoirs are important as they evaluate and quantify the complex multi-physical effects in geothermal reservoirs. However, previous modeling efforts lack the study focusing on the emission reduction efficiency and the deformation at geothermal wellbores caused by geothermal water extraction/circulation. Emission efficiency is rather relevant in geothermal projects introduced in areas characterized by elevated air pollution where the utilization of geothermal energy is as an alternative to burning fossil fuels. Deformation at geothermal wellbores is also relevant as significant deformation caused by water extraction can lead to geothermal wellbore instability and can consequently decrease the effectiveness of the heat extraction process in geothermal wells. In this study, the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir in Daming County, China, are numerically investigated based on a coupled multi-physical model. Relationships between the efficiency of emission reduction and heat extraction, deformation at geothermal well locations, and geothermal field parameters including well spacing, heat production rate, re-injection temperature, rock stiffness, and geothermal well placement patterns are analyzed. Results show that, although large heat production rates and low re-injection temperatures can lead to decreased heat production in the last 8 years of heat extraction, they still improve the overall heat production capacity and emission reduction capacity. Also, the emission reduction capacity is positively correlated with the heat production capacity. Deformation at geothermal wellbore locations is alleviated by smaller well spacing, lower heat production rates, and smaller numbers of injectors in the well pattern, and by

Occupational heat stress assessment and protective strategies in the context of climate change

Science.gov (United States)

Gao, Chuansi; Kuklane, Kalev; Östergren, Per-Olof; Kjellstrom, Tord

2018-03-01

Global warming will unquestionably increase the impact of heat on individuals who work in already hot workplaces in hot climate areas. The increasing prevalence of this environmental health risk requires the improvement of assessment methods linked to meteorological data. Such new methods will help to reveal the size of the problem and design appropriate interventions at individual, workplace and societal level. The evaluation of occupational heat stress requires measurement of four thermal climate factors (air temperature, humidity, air velocity and heat radiation); available weather station data may serve this purpose. However, the use of meteorological data for occupational heat stress assessment is limited because weather stations do not traditionally and directly measure some important climate factors, e.g. solar radiation. In addition, local workplace environmental conditions such as local heat sources, metabolic heat production within the human body, and clothing properties, all affect the exchange of heat between the body and the environment. A robust occupational heat stress index should properly address all these factors. This article reviews and highlights a number of selected heat stress indices, indicating their advantages and disadvantages in relation to meteorological data, local workplace environments, body heat production and the use of protective clothing. These heat stress and heat strain indices include Wet Bulb Globe Temperature, Discomfort Index, Predicted Heat Strain index, and Universal Thermal Climate Index. In some cases, individuals may be monitored for heat strain through physiological measurements and medical supervision prior to and during exposure. Relevant protective and preventive strategies for alleviating heat strain are also reviewed and proposed.

A tentative correlation between seismic activity and changes in the composition of thermal waters on Vulcano Island, Italy

Energy Technology Data Exchange (ETDEWEB)

Bolognesi, Luca [CNR-International Institute for Geothermal Research, Pisa (Italy)

1997-06-01

On Vulcano Island, Italy, the thermal water in the shallow water well W2 is a mixture of reservoir water and shallow steam-heated groundwater of meteoric origin. In the period 1986-1988, the composition of the W2 water changed just before two sequences of tectonic earthquakes, from the almost pure reservoir component to the almost pure steam-heated meteoric component. After the seismic activity, the W2 water returned to is pre-earthquake reservoir composition. These changes in composition could be explained by the dilatancy-fluid diffusion model. According to this model, the observed variations in W2 water composition could be in the consequence of stress build-up prior to the seismic events, and stress reduction afterwards. (Author)

Urban heat island investigations in Arctic cities of northwestern Russia

Science.gov (United States)

Shumilov, Oleg I.; Kasatkina, Elena A.; Kanatjev, Alexander G.

2017-12-01

Urban microclimate peculiarities in two Arctic cities in northwestern Russia—Kirovsk (67.62°N, 33.67°E) and Apatity (67.57°N, 33.38°E)—were investigated by using mobile temperature records. The experiment was carried out in and around Apatity and Kirovsk in February 2014 and December 2016. The DS18B20 digital thermometer was installed on the roof of a car (height: approximately 1.2 m) to measure and record temperature variations automatically. In addition to the digital thermometer, the car was also equipped with an onboard global positioning system, allowing every temperature measurement to be referenced with an altitude and a latitude/longitude position. The possibility of urban heat island formation in these polar cities, above the Arctic Circle, was studied. Our analysis indicated that on 11 February 2014, the temperature varied in accordance with the background environmental lapse rate (-0.0045°C m-1), and nearly corresponded to it (-0.0165°C m-1) on 12 February 2014. On 6 December 2016, a strong local temperature inversion with a positive value of 0.032°C m-1 was detected, seemingly caused by the formation of a cold air pool in the valley near Kirovsk. It was found that the temperature variations within and outside these cities are strongly influenced by local topographic effects and the physical conditions of the atmospheric boundary layer.

Nutritional impact of sodium reduction strategies on sodium intake from processed foods

NARCIS (Netherlands)

Hendriksen, M.A.H.; Verkaik-Kloosterman, J.; Noort, M.W.; Raaij, J.M.A. van

2015-01-01

Background/objectives: Sodium intake in the Netherlands is substantially above the recommended intake of 2400 mg/day. This study aimed to estimate the effect of two sodium reduction strategies, that is, modification of the composition of industrially processed foods toward the technologically

Nutritional impact of sodium reduction strategies on sodium intake from processed foods

NARCIS (Netherlands)

Hendriksen, M.A.H.; Verkaik-Kloosterman, J.; Noort, M.W.J.; Raaij, van J.M.A.

2015-01-01

Background/objectives: Sodium intake in the Netherlands is substantially above the recommended intake of 2400¿mg/day. This study aimed to estimate the effect of two sodium reduction strategies, that is, modification of the composition of industrially processed foods toward the technologically

Estimating the potential for industrial waste heat reutilization in urban district energy systems: method development and implementation in two Chinese provinces

Science.gov (United States)

Tong, Kangkang; Fang, Andrew; Yu, Huajun; Li, Yang; Shi, Lei; Wang, Yangjun; Wang, Shuxiao; Ramaswami, Anu

2017-12-01

Utilizing low-grade waste heat from industries to heat and cool homes and businesses through fourth generation district energy systems (DES) is a novel strategy to reduce energy use. This paper develops a generalizable methodology to estimate the energy saving potential for heating/cooling in 20 cities in two Chinese provinces, representing cold winter and hot summer regions respectively. We also conduct a life-cycle analysis of the new infrastructure required for energy exchange in DES. Results show that heating and cooling energy use reduction from this waste heat exchange strategy varies widely based on the mix of industrial, residential and commercial activities, and climate conditions in cities. Low-grade heat is found to be the dominant component of waste heat released by industries, which can be reused for both district heating and cooling in fourth generation DES, yielding energy use reductions from 12%-91% (average of 58%) for heating and 24%-100% (average of 73%) for cooling energy use in the different cities based on annual exchange potential. Incorporating seasonality and multiple energy exchange pathways resulted in energy savings reductions from 0%-87%. The life-cycle impact of added infrastructure was small (<3% for heating) and 1.9% ~ 6.5% (cooling) of the carbon emissions from fuel use in current heating or cooling systems, indicating net carbon savings. This generalizable approach to delineate waste heat potential can help determine suitable cities for the widespread application of industrial waste heat re-utilization.

Seasonal Variations of the Surface Urban Heat Island in a Semi-Arid City

Directory of Open Access Journals (Sweden)

Sirous Haashemi

2016-04-01

Full Text Available The process of the surface urban heat island (SUHI varies with latitude, climate, topography and meteorological conditions. This study investigated the seasonal variability of SUHI in the Tehran metropolitan area, Iran, with respect to selected surface biophysical variables. Terra Moderate Resolution Imaging Spectroradiometer (MODIS Land Surface Temperature (LST was retrieved as nighttime LST data, while daytime LST was retrieved from Landsat 8 Thermal Infrared Sensor (TIRS using the split-window algorithm. Both data covered the time period from September 2013 to September 2015. To assess SUHI intensity, we employed three SUHI indicators, i.e., the LST difference of urban-rural, that of urban-agriculture and that of urban-water. Physical and biophysical surface variables, including land use and land cover (LULC, elevation, impervious surface (IS, fractional vegetation cover (FVC and albedo, were selected to estimate the relationship between LST seasonal variability and the surface properties. Results show that an inversion of the SUHI phenomenon (i.e., surface urban cool island existed at daytime with the maximal value of urban-rural LST difference of −4 K in March; whereas the maximal value of SUHI at nighttime yielded 3.9 K in May. When using the indicators of urban-agriculture and urban-water LST differences, the maximal value of SUHI was found to be 8.2 K and 15.5 K, respectively. Both results were observed at daytime, suggesting the role of bare soils in the inversion of the SUHI phenomenon with the urban-rural indicator. Maximal correlation was observed in the relationship between night LST and elevation in spring (coefficient: −0.76, night LST and IS in spring (0.60, night LST and albedo in winter (−0.53 and day LST with fractional vegetation cover in summer (−0.41. The relationship between all surface properties with LST possessed large seasonal variations, and thus, using these relationships for SUHI modeling may not be

Modeling nitrate-nitrogen load reduction strategies for the des moines river, iowa using SWAT

Science.gov (United States)

Schilling, K.E.; Wolter, C.F.

2009-01-01

The Des Moines River that drains a watershed of 16,175 km2 in portions of Iowa and Minnesota is impaired for nitrate-nitrogen (nitrate) due to concentrations that exceed regulatory limits for public water supplies. The Soil Water Assessment Tool (SWAT) model was used to model streamflow and nitrate loads and evaluate a suite of basin-wide changes and targeting configurations to potentially reduce nitrate loads in the river. The SWAT model comprised 173 subbasins and 2,516 hydrologic response units and included point and nonpoint nitrogen sources. The model was calibrated for an 11-year period and three basin-wide and four targeting strategies were evaluated. Results indicated that nonpoint sources accounted for 95% of the total nitrate export. Reduction in fertilizer applications from 170 to 50 kg/ha achieved the 38% reduction in nitrate loads, exceeding the 34% reduction required. In terms of targeting, the most efficient load reductions occurred when fertilizer applications were reduced in subbasins nearest the watershed outlet. The greatest load reduction for the area of land treated was associated with reducing loads from 55 subbasins with the highest nitrate loads, achieving a 14% reduction in nitrate loads achieved by reducing applications on 30% of the land area. SWAT model results provide much needed guidance on how to begin implementing load reduction strategies most efficiently in the Des Moines River watershed. ?? 2009 Springer Science+Business Media, LLC.

An interdisciplinary approach to volcanic risk reduction under conditions of uncertainty: a case study of Tristan da Cunha

Science.gov (United States)

Hicks, A.; Barclay, J.; Simmons, P.; Loughlin, S.

2013-12-01

This research project adopted an interdisciplinary approach to volcanic risk reduction on the remote volcanic island of Tristan da Cunha (South Atlantic). New data were produced that: (1) established no spatio-temporal pattern to recent volcanic activity; (2) quantified the high degree of scientific uncertainty around future eruptive scenarios; (3) analysed the physical vulnerability of the community as a consequence of their geographical isolation and exposure to volcanic hazards; (4) evaluated social and cultural influences on vulnerability and resilience. Despite their isolation and prolonged periods of hardship, islanders have demonstrated an ability to cope with and recover from adverse events. This resilience is likely a function of remoteness, strong kinship ties, bonding social capital, and persistence of shared values and principles established at community inception. While there is good knowledge of the styles of volcanic activity on Tristan, given the high degree of scientific uncertainty about the timing, size and location of future volcanism, a qualitative scenario planning approach was used as a vehicle to convey this information to the islanders. This deliberative, anticipatory method allowed on-island decision makers to take ownership of risk identification, management and capacity building within their community. This paper demonstrates the value of integrating social and physical sciences with development of effective, tailored communication strategies in volcanic risk reduction.

Performance analysis of ORC power generation system with low-temperature waste heat of aluminum reduction cell

Science.gov (United States)

Wang, Zhiqi; Zhou, Naijun; Jing, Guo

Performance of organic Rankine cycle (ORC) system to recover low-temperature waste heat from aluminum reduction cell was analyzed. The temperature of waste heat is 80°C-200°C and the flow rate is 3×105m3/h. The pinch temperature difference between waste heat and working fluids is 10°C. The results show that there is optimal evaporating temperature for maximum net power under the same pinch point. For heat source temperature range of 80°C-140°C and 150°C-170°C, the working fluid given biggest net power is R227ea and R236fa, respectively. When the temperature is higher than 180°C, R236ea generates the biggest net power. The variation of heat source temperature has important effect on net power. When the temperature decreases 10%, the net power will deviate 30% from the maximum value.

Study of the Relationships between the Spatial Extent of Surface Urban Heat Islands and Urban Characteristic Factors Based on Landsat ETM+ Data

Directory of Open Access Journals (Sweden)

Jinqu Zhang

2008-11-01

Full Text Available Ten cities with different population and urban sizes located in the Pearl River Delta, Guangdong Province, P.R. China were selected to study the relationships between the spatial extent of surface urban heat islands (SUHI and five urban characteristic factors such as urban size, development area, water proportion, mean NDVI (Normalized Vegetation Index and population density, etc. The spatial extent of SUHI was quantified by using the hot island area (HIA. All the cities are almost at the same latitude, showing similar climate and solar radiation, the influence of which could thus be eliminated during our computation and comparative study. The land surface temperatures (LST were retrieved from the data of Landsat 7 Enhanced Thematic Mapper Plus (ETM+ band 6 using a mono-window algorithm. A variance-segmenting method was proposed to compute HIA for each city from the retrieved LST. Factors like urban size, development area and water proportion were extracted directly from the classification images of the same ETM+ data and the population density factor is from the official census. Correlation and regression analyses were performed to study the relationships between the HIA and the related factors, and the results show that HIA is highly correlated to urban size (r=0.95, population density (r=0.97 and development area (r=0.83 in this area. It was also proved that a weak negative correlation existed between HIA and both mean NDVI and water proportion for each city. Linear functions between HIA and its related factors were established, respectively. The HIA can reflect the spatial extent and magnitude of the surface urban heat island effect, and can be used as reference in the urban planning.

Swedish biomass strategies to reduce CO2 emission and oil use in an EU context

International Nuclear Information System (INIS)

Joelsson, Jonas; Gustavsson, Leif

2012-01-01

Swedish energy strategies for transportation, space heating and pulp industries were evaluated with a focus on bioenergy use. The aims were to 1) study trade-offs between reductions in CO 2 emission and oil use and between Swedish reductions and EU reductions, 2) compare the potential contributions of individual reduction measures, 3) quantify the total CO 2 emission and oil use reduction potentials. Swedish energy efficiency measures reduced EU CO 2 emission by 45–59 Mt CO 2 /a, at current biomass use and constant oil use. Doubling Swedish bioenergy use yielded an additional 40 Mt CO 2 /a reduction. Oil use could be reduced, but 36–81 kt of reductions in CO 2 emission would be lost per PJ of oil use reduction. Swedish fossil fuel use within the studied sectors could be nearly eliminated. The expansion of district heating and cogeneration of heat with a high electricity yield were important measures. Plug-in hybrid electric cars reduced CO 2 emission compared with conventional cars, and the difference was larger with increasing oil scarcity. The introduction of black liquor gasification in pulp mills also gave large CO 2 emission reduction. Motor fuel from biomass was found to be a feasible option when coal is the marginal fuel for fossil motor fuel production. -- Highlights: ► Bioenergy is compared to optimized fossil fuel use under different oil availability constraints. ► Swedish strategies are evaluated with respect to CO 2 emission and oil use reduction within Sweden and the EU. ► Efficiency measures give the largest reductions but increased bioenergy use is also important. ► District heating expansion, high electricity yield CHP, increased vehicle efficiency and PHEVs are important options. ► The studied sectors in Sweden could become nearly fossil-fuel free and yield an energy surplus.

Effect of urbanization activities towards the formation of urban heat island in Cameron Highlands, Malaysia

Science.gov (United States)

Ibrahim, M. H.; Latiff, N. A. A.; Ismail, K.; Isa, N. K. M.

2018-04-01

This study carried out to study the effect of urbanization activities towards the formation of Urban Heat Islands (UHI) in Cameron Highlands (CH).The aim of this study is to identify the formation of UHI in CH following the urbanization activities. This study also involved two main data that are primary through field survey and secondary data from collection data. In addition, this study was used qualitative and quantitative method. The data was taken two times a day, at a day and night between the hours of 12:00 to 14:00 and 19:00 to 21:00. Data in this study analyzed by using correlation analysis and analysis of Geographic Information Systems (GIS) which known as interpolation. Result found the formation of UHI in CH was concentrated at city centre namely in Pekan Tanah Rata. From the whole average value, city centre was recorded the highest reading of temperatures which is 30.5°C, while reading of temperature for subtown and suburban was recorded 28.6°C and 23.8°C. Average of humidity in CH during the day was recorded as highest reading in the suburban area namely Tringkap Bee Farm (station 11) which is 58.4%. Then, average of humidity in CH at night was recorded highest reading in the suburban area namely Habu Mini Market 91 (station 9) which the value is 83.2%. The reading of wind speed in CH during the day recorded the highest reading day at the suburban namely Tringkap Bee Farm (station 11) which the value is 2.3 m/s. While, following the reading of wind speed in CH at night, suburban namely Habu Mini Market 91(station 9) was recorded the highest reading which is 0.8 m/s. The Intensity of Urban Heat Island in CH during the day was recorded 2.8°C, while at night intensity of UHI was recorded 1.4°C. Overall, the urbanization activities in CH had caused the formation of UHI. Therefore, measures of legislation such as protect forest from development by control the urbanization activities need to be implemented so that the formation of UHI can be reduced and

Spatially Analyzing the Inequity of the Hong Kong Urban Heat Island by Socio-Demographic Characteristics

Directory of Open Access Journals (Sweden)

Man Sing Wong

2016-03-01

Full Text Available Recent studies have suggested that some disadvantaged socio-demographic groups face serious environmental-related inequities in Hong Kong due to the rising ambient urban temperatures. Identifying heat-vulnerable groups and locating areas of Surface Urban Heat Island (SUHI inequities is thus important for prioritizing interventions to mitigate death/illness rates from heat. This study addresses this problem by integrating methods of remote sensing retrieval, logistic regression modelling, and spatial autocorrelation. In this process, the SUHI effect was first estimated from the Land Surface Temperature (LST derived from a Landsat image. With the scale assimilated to the SUHI and socio-demographic data, a logistic regression model was consequently adopted to ascertain their relationships based on Hong Kong Tertiary Planning Units (TPUs. Lastly, inequity “hotspots” were derived using spatial autocorrelation methods. Results show that disadvantaged socio-demographic groups were significantly more prone to be exposed to an intense SUHI effect: over half of 287 TPUs characterized by age groups of 60+ years, secondary and matriculation education attainment, widowed, divorced and separated, low and middle incomes, and certain occupation groups of workers, have significant Odds Ratios (ORs larger than 1.2. It can be concluded that a clustering analysis stratified by age, income, educational attainment, marital status, and occupation is an effective way to detect the inequity hotspots of SUHI exposure. Additionally, inequities explored using income, marital status and occupation factors were more significant than the age and educational attainment in these areas. The derived maps and model can be further analyzed in urban/city planning, in order to mitigate the physical and social causes of the SUHI effect.

Developing a strategy for improving efficiency in the heating sector in central and eastern Europe

Energy Technology Data Exchange (ETDEWEB)

Meyer, A.S. [World Bank, Washington, DC (United States)

1995-12-31

Heating is a vital energy service in Central and Eastern Europe, but the current delivery mechanisms are riddled with problems. District heating (DH) in its present technical form and with the present management structures is an inefficient system which produces expensive heat. Customers cannot control it and react to overheating by opening windows, even in winter. DH facilities together with other forms of individual heating are responsible for air pollution, causing severe impacts on the health of urban residents. The issues relating to DH are discussed, the first World Bank activities and experiences with projects in Poland are analyzed, and the cornerstones of a strategy to support future World Bank financing and the development of sound heating policies in CEE are presented.

Comparative evaluation of three heat transfer enhancement strategies in a grooved channel

Energy Technology Data Exchange (ETDEWEB)

Herman, C.; Kang, E. [Dept. of Mechanical Engineering, Johns Hopkins Univ., Baltimore, MD (United States)

2001-09-01

Results of a comparative evaluation of three heat transfer enhancement strategies for forced convection cooling of a parallel plate channel populated with heated blocks, representing electronic components mounted on printed circuit boards, are reported. Heat transfer in the reference geometry, the asymmetrically heated parallel plate channel, is compared with that for the basic grooved channel, and the same geometry enhanced by cylinders and vanes placed above the downstream edge of each heated block. In addition to conventional heat transfer and pressure drop measurements, holographic interferometry combined with high-speed cinematography was used to visualize the unsteady temperature fields in the self-sustained oscillatory flow. The locations of increased heat transfer within one channel periodicity depend on the enhancement technique applied, and were identified by analyzing the unsteady temperature distributions visualized by holographic interferometry. This approach allowed gaining insight into the mechanisms responsible for heat transfer enhancement. Experiments were conducted at moderate flow velocities in the laminar, transitional and turbulent flow regimes. Reynolds numbers were varied in the range Re = 200-6500, corresponding to flow velocities from 0.076 to 2.36 m/s. Flow oscillations were first observed between Re = 1050 and 1320 for the basic grooved channel, and around Re = 350 and 450 for the grooved channels equipped with cylinders and vanes, respectively. At Reynolds numbers above the onset of oscillations and in the transitional flow regime, heat transfer rates in the investigated grooved channels exceeded the performance of the reference geometry, the asymmetrically heated parallel plate channel. Heat transfer in the grooved channels enhanced with cylinders and vanes showed an increase by a factor of 1.2-1.8 and 1.5-3.5, respectively, when compared to data obtained for the basic grooved channel; however, the accompanying pressure drop penalties

Isolation of thermotolerant Vermamoeba vermiformis strains from water sources in Lanzarote Island, Canary Islands, Spain.

Science.gov (United States)

Reyes-Batlle, María; Wagner, Carolina; Zamora-Herrera, Jonadab; Vargas-Mesa, Alejandro; Sifaoui, Ines; González, Ana C; López-Arencibia, Atteneri; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Lorenzo-Morales, Jacob

2016-09-01

In this study, twenty water samples were collected in the island of Lanzarote, Canary Islands, Spain in order to check for the presence of V. vermiformis strains in these samples. Water samples were cultured on 2% Non-Nutrient Agar (NNA) plates covered with a thin layer of heat killed E. coli and checked daily for the presence of Vermamoeba. After a week, V. vermiformis amoebae were observed in 2 of the 20 processed samples (10%) incubated at room temperature and 37°C. Molecular characterization was carried out by amplifying the 18S rDNA gene and DNA sequencing in order to confirm the identity of the isolated amoebic strains. To the best of our knowledge, this is the first report on the presence of FLA in environmental sources in Lanzarote Island and the first report of Vermamoeba vermiformis in water sources in this island. Furthermore, the two strains isolated in this study were collected in recreational areas with close contact with humans and thus awareness should be raised.

The Conundrum of Impacts of Climate Change on Urbanization and the Urban Heat Island Effect

Science.gov (United States)

Quattrochi, Dale A.

2011-01-01

The twenty-first century is the first urban century according to the United Nations Development Program. The focus on cities reflects awareness of the growing percentage of the world's population that lives in urban areas. In 2000, approximately 3 billion people representing about 40% of the global population resided in urban areas. The United Nations estimates that by 2025, 60% of the world s population will live in urban areas. As a consequence, the number of megacities (those cities with populations of 10 million inhabitants or more) will increase by 100 by 2025. Thus, there is a critical need to understand the spatial growth of urban areas and what the impacts are on the environment. Moreover, there is a critical need to assess how under global climate change, cities will affect the local, regional, and even global climate. As urban areas increase in size, it is anticipated there will be a concomitant growth of the Urban Heat Island effect (UHI), and the attributes that are related to its spatial and temporal dynamics. Therefore, how climate change, including the dynamics of the UHI, will affect the urban environment, must be explored to help mitigate potential impacts on the environment (e.g., air quality, heat stress, vectorborne disease) and on human health and well being, to develop adaptation schemes to cope with these impacts.

Different shades of green on small islands

Directory of Open Access Journals (Sweden)

Teresa Tiago

2016-11-01

Full Text Available Many small islands exist as tourism destinations worldwide. In the 1990s, the growth of environmental consciousness led some small islands to question their mass tourism offers and to refocus on more sustainable propositions. However, it remains unclear whether hospitality firms see these sustainability related efforts as drivers of success and whether tourists value this dimension when choosing or recommending a destination. This study chose a small island destination to address these questions using data covering firm and tourism perceptions of green products. The results show that tourists tend to value green efforts with different intensities, corresponding to three segments: Light Green, Green, and Super Green. These findings should help hotels adjust their communication strategies and develop new services. Further, destination marketing organizations can devise a consistent destination strategy, integrating all stakeholders by including their most valued concepts.

Roles of Urban Tree Canopy and Buildings in Urban Heat Island Effects: Parameterization and Preliminary Results

Science.gov (United States)

Loughner, Christopher P.; Allen, Dale J.; Zhang, Da-Lin; Pickering, Kenneth E.; Dickerson, Russell R.; Landry, Laura

2012-01-01

Urban heat island (UHI) effects can strengthen heat waves and air pollution episodes. In this study, the dampening impact of urban trees on the UHI during an extreme heat wave in the Washington, D.C., and Baltimore, Maryland, metropolitan area is examined by incorporating trees, soil, and grass into the coupled Weather Research and Forecasting model and an urban canopy model (WRF-UCM). By parameterizing the effects of these natural surfaces alongside roadways and buildings, the modified WRF-UCM is used to investigate how urban trees, soil, and grass dampen the UHI. The modified model was run with 50% tree cover over urban roads and a 10% decrease in the width of urban streets to make space for soil and grass alongside the roads and buildings. Results show that, averaged over all urban areas, the added vegetation decreases surface air temperature in urban street canyons by 4.1 K and road-surface and building-wall temperatures by 15.4 and 8.9 K, respectively, as a result of tree shading and evapotranspiration. These temperature changes propagate downwind and alter the temperature gradient associated with the Chesapeake Bay breeze and, therefore, alter the strength of the bay breeze. The impact of building height on the UHI shows that decreasing commercial building heights by 8 m and residential building heights by 2.5 m results in up to 0.4-K higher daytime surface and near-surface air temperatures because of less building shading and up to 1.2-K lower nighttime temperatures because of less longwave radiative trapping in urban street canyons.

Suburban heat island effect in groundwater energy utilisation in Nordic climate - case study

Science.gov (United States)

Arola, Teppo

2017-04-01

We present the preliminary results from the initial thermogeological characterization of Finland's first-ever planned large-scale aquifer thermal energy storage (ATES) facility. The site is located in the Asko area (Lahti), at a latitude of 60°59'N. In particular, emphasis is put on the results from an aquifer's pumping test performed in July / August 2016 to investigate the potential implication of suburban heat island (SUHI) effect to ATES system on the naturally cold groundwater area. The site has been under geological investigation since July 2015. At a regional scale, the groundwater's natural temperature is about 5.8- 6°C. However, preliminary measurements during the investigations revealed that local groundwater temperature ranged between 7.5 to 8.7 °C in Asko area. The highest temperature was observed underneath buildings, suggesting that higher-than-average temperature is most likely influenced due to anthropogenic heat flux into the ground. The pumping test was performed for 39 days, of which 28 days with groundwater withdrawal and 11 days of heads recovery. The pumped volumes range from 350 to 540 m3/d leading the total volume of 10400 m3 of groundwater. Groundwater temperatures were continuously measured from pumping test well and two observation piezometers during the entire test. The results indicated that aquifer's temperature remained nearly constant being between 7.4 to 7.9 °C during the test period. Heat pulses with temperature variation of 0.1 to 0.3 °C were observed in the pumping well and nearest monitoring well (19 meters from pumping well) during the pumping test and recovery phase. We estimate that the pulses were due to rapidly changed groundwater flowing conditions and pulse indicate "new groundwater" flow to the well. Overall, the preliminary test suggests that groundwater temperature are expected to remain elevated during the ATES system operation. Elevated temperature due the SUHI effect increases groundwater heating potential

Heat flow and radioactivity studies in the Ross Island-dry valley area, Antarctica and their tectonic implications

International Nuclear Information System (INIS)

Bucher, G.J.

1980-01-01

In conjunction with the Dry Valley Drilling Project, the University of Wyoming conducted heat flow and basement radioactivity studies in the Ross Island-dry valley area of southern Victoria Land, Antarctica. This part of Antarctica is characterized by late Cenozoic alkaline basaltic volcanism and uplift. Six heat flow (q) values for the area range from 1.4 to 2.0 HFU, with a mean value of 1.7 HFU. Radioactive heat production (A) values for basement rocks from the dry valleys range from 2.2 to 4.1 HGU, with a mean value of 3.0 HGU. The combined q-A data imply that this area is a zone of high reduced heat flow, similar to the Basin and Range province in the western United States and other zones of late Cenozoic tectonof Antarctica is probably in the range of 1.2 to 1.6 HFU, which is about 50 to 100% higher than the reduced flux which characterizes stable continental areas. The results of the transient conductive models presented herein imply that the high flux in this part of Antarctica cannot be explained by the residual thermal effects of a major episode of lithospheric thinning associated with the generation of the Ferrar Dolerites. The correlation between steady conductive thermal models and the late Cenozoic, silica-undersaturated, alkaline basalts of the region is similarly obscure. For example, purely conductive steady-state temperature-depth models predict partial melting at depths of only 45 to 50 km in the mantle, whereas geochemical data for the volcanic units are consistent with the basalts being generated at depths of at least 60 to 80 km

The role of poverty reduction strategies in achieving the millennium development goals

NARCIS (Netherlands)

Bezemer, Dirk; Eggen, Andrea

2008-01-01

We provide a literature overview of the linkages between Poverty Reduction Strategy Papers (PRSPs) and the Millenium Development Goals (MDGs) and use novel data to examine their relation. We find that introduction of a PRSP is associated with progress in four of the nine MDG indicators we study.

Heat Roadmap Europe

DEFF Research Database (Denmark)

Connolly, David; Mathiesen, Brian Vad; Lund, Henrik

2015-01-01

This document is a summary of the key technical inputs for the modelling of the heat strategy for Europe outlined in the latest Heat Roadmap Europe studies [1, 2]. These studies quantify the impact of alternative heating strategies for Europe in 2030 and 2050. The study is based on geographical...... information systems (GIS) and energy system analyses. In this report, the inputs for other modelling tools such as PRIMES are presented, in order to enable other researches to generate similar heating scenarios for Europe. Although Heat Roadmap Europe presents a complete heat strategy for Europe, which...... includes energy efficiency, individual heating units (such as boilers and heat pumps), and heat networks, the recommendations here are primarily relating to the potential and modelling of district heating. Although other solutions will play a significant role in decarbonising the heating and cooling sector...

Passive Decay Heat Removal Strategy of Integrated Passive Safety System (IPSS) for SBO-combined Accidents

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Ho; Chang, Soon Heung; Jeong, Yong Hoon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2014-10-15

The weak points of nuclear safety would be in outmoded nuclear power plants like the Fukushima reactors. One of the systems for the safety enhancement is integrated passive safety system (IPSS) proposed after the Fukushima accidents. It has the five functions for the prevention and mitigation of a severe accident. Passive decay heat removal (PDHR) strategy using IPSS is proposed for coping with SBO-combined accidents in this paper. The two systems for removing decay heat before core-melt were applied in the strategy. The accidents were simulated by MARS code. The reference reactor was OPR1000, specifically Ulchin-3 and 4. The accidents included loss-of-coolant accidents (LOCA) because the coolant losses could be occurred in the SBO condition. The examples were the stuck open of PSV, the abnormal open of SDV and the leakage of RCP seal water. Also, as LOCAs with the failure of active safety injection systems were considered, various LOCAs were simulated in SBO. Based on the thermal hydraulic analysis, the probabilistic safety analysis was carried out for the PDHR strategy to estimate the safety enhancement in terms of the variation of core damage frequency. AIMS-PSA developed by KAERI was used for calculating CDF of the plant. The IPSS was applied in the PDHR strategy which was developed in order to cope with the SBO-combined accidents. The estimation for initiating SGGI or PSIS was based on the pressure in RCS. The simulations for accidents showed that the decay heat could be removed for the safety duration time in SBO. The increase of safety duration time from the strategy provides the increase of time for the restoration of AC power.

Recurrent selection as breeding strategy for heat tolerance in wheat

OpenAIRE

Juarez Campolina Machado; Moacil Alves de Souza; Davi Melo de Oliveira; Adeliano Cargnin; Aderico Júnior Badaró Pimentel; Josiane Cristina de Assis

2010-01-01

The development of heat-tolerant varieties is an important goal of wheat breeding programs, requiringefficient selection methods. In the present study the use of recurrent selection was evaluated as a strategy to improve heatstress tolerance in wheat. Two cycles of recurrent selection were performed in experiments conducted in research areas of theUniversidade Federal de Viçosa, located in Coimbra-MG and Viçosa-MG, in 2004 and 2007, in two growing seasons (summerand winter). The genetic gain ...

Analysis of a combined heating and cooling system model under different operating strategies

Science.gov (United States)

Dzierzgowski, Mieczysław; Zwierzchowski, Ryszard

2017-11-01

The paper presents an analysis of a combined heating and cooling system model under different operating strategies. Cooling demand for air conditioning purposes has grown steadily in Poland since the early 1990s. The main clients are large office buildings and shopping malls in downtown locations. Increased demand for heat in the summer would mitigate a number of problems regarding District Heating System (DHS) operation at minimum power, affecting the average annual price of heat (in summertime the share of costs related to transport losses is a strong cost factor). In the paper, computer simulations were performed for different supply network water temperature, assuming as input, real changes in the parameters of the DHS (heat demand, flow rates, etc.). On the basis of calculations and taking into account investment costs of the Absorption Refrigeration System (ARS) and the Thermal Energy Storage (TES) system, an optimal capacity of the TES system was proposed to ensure smooth and efficient operation of the District Heating Plant (DHP). Application of ARS with the TES system in the DHS in question increases net profit by 19.4%, reducing the cooling price for consumers by 40%.

Effect of heating on the suppression of tearing modes in tokamaks.

Science.gov (United States)

Classen, I G J; Westerhof, E; Domier, C W; Donné, A J H; Jaspers, R J E; Luhmann, N C; Park, H K; van de Pol, M J; Spakman, G W; Jakubowski, M W

2007-01-19

The suppression of (neoclassical) tearing modes is of great importance for the success of future fusion reactors like ITER. Electron cyclotron waves can suppress islands, both by driving noninductive current in the island region and by heating the island, causing a perturbation to the Ohmic plasma current. This Letter reports on experiments on the TEXTOR tokamak, investigating the effect of heating, which is usually neglected. The unique set of tools available on TEXTOR, notably the dynamic ergodic divertor to create islands with a fully known driving term, and the electron cyclotron emission imaging diagnostic to provide detailed 2D electron temperature information, enables a detailed study of the suppression process and a comparison with theory.

Intraspecific variation in cellular and biochemical heat response strategies of Mediterranean Xeropicta derbentina [Pulmonata, Hygromiidae].

Directory of Open Access Journals (Sweden)

Sandra Troschinski

Full Text Available Dry and hot environments challenge the survival of terrestrial snails. To minimize overheating and desiccation, physiological and biochemical adaptations are of high importance for these animals. In the present study, seven populations of the Mediterranean land snail species Xeropicta derbentina were sampled from their natural habitat in order to investigate the intraspecific variation of cellular and biochemical mechanisms, which are assigned to contribute to heat resistance. Furthermore, we tested whether genetic parameters are correlated with these physiological heat stress response patterns. Specimens of each population were individually exposed to elevated temperatures (25 to 52°C for 8 h in the laboratory. After exposure, the health condition of the snails' hepatopancreas was examined by means of qualitative description and semi-quantitative assessment of histopathological effects. In addition, the heat-shock protein 70 level (Hsp70 was determined. Generally, calcium cells of the hepatopancreas were more heat resistant than digestive cells - this phenomenon was associated with elevated Hsp70 levels at 40°C.We observed considerable variation in the snails' heat response strategy: Individuals from three populations invested much energy in producing a highly elevated Hsp70 level, whereas three other populations invested energy in moderate stress protein levels - both strategies were in association with cellular functionality. Furthermore, one population kept cellular condition stable despite a low Hsp70 level until 40°C exposure, whereas prominent cellular reactions were observed above this thermal limit. Genetic diversity (mitochondrial cytochrome c oxidase subunit I gene within populations was low. Nevertheless, when using genetic indices as explanatory variables in a multivariate regression tree (MRT analysis, population structure explained mean differences in cellular and biochemical heat stress responses, especially in the group

Review of successful hospital readmission reduction strategies and the role of health information exchange.

Science.gov (United States)

Kash, Bita A; Baek, Juha; Davis, Elise; Champagne-Langabeer, Tiffany; Langabeer, James R

2017-08-01

The United States has invested substantially in technologies that enable health information exchange (HIE), which in turn can be deployed to reduce avoidable hospital readmission rates in many communities. With avoidable hospital readmissions as the primary focus, this study profiles successful hospital readmission rate reduction initiatives that integrate HIE as a strategy. We hypothesized that the use of HIE is associated with decreased hospital readmissions beyond other observed population health benefits. Results of this systematic review are used to describe and profile successful readmission reduction programs that integrate HIE as a tool. A systematic review of literature provided an understanding of the use of HIE as a strategy to reduce hospital readmission rates. We conducted a review of 4,862 citations written in English about readmission reduction strategies from January 2006 to September 2016 in the MEDLINE-PubMed database. Of these, 106 studies reported 30-day readmission rates as an outcome and only 13 articles reported using HIE. Only a very small number (12%) of hospitals incorporated HIE as a primary tool for evidence-based readmission reduction initiatives. Information exchange between providers has been suggested to play a key role in reducing avoidable readmission rates, yet there is not currently evidence supporting current HIE-enabled readmission initiatives. Most successful readmission reduction programs demonstrate collaboration with primary care providers to augment transitions of care to existing care management functions without additional staff while using effective information exchange capabilities. This research confirms there is very little integration of HIE into health systems readmissions initiatives. There is a great opportunity to achieve population health targets using the HIE infrastructure. Hospitals should consider partnering with primary care clinics to implement multifaceted transitions of care programs to significantly

Detailed profile of m=2 islands with TVTS on JFT-2M

International Nuclear Information System (INIS)

Yamauchi, T.; Grek, B.; Hoshino, K.; Le Blanc, B.; Johnson, D.; Felt, J.; Shiina, T.; Kurita, G.; Ishige, Y.; Kozawa, H.

1996-01-01

The detailed electron temperature profile (spatial resolution: 0.86 cm) of a low density JFT-2M plasma is measured with the TV Thomson scattering system (TVTS). Flat profiles showing the electron temperature shapes of m=2/n=1 islands are presented, which are in contrast to that without islands. On the other hand, the m=2/n=1 islands are effectively suppressed with local ECRH heating. (orig.)