Eric Graham - Academia.edu (original) (raw)

Papers by Eric Graham

Research paper thumbnail of Root Water Uptake, Leaf Water Storage and Gas Exchange of a Desert Succulent: Implications for Root System Redundancy

Annals of Botany

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Research paper thumbnail of Tracking the rhythm of the seasons in theface of global change: phenological researchin the 21st century

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Research paper thumbnail of SPAN: A Sensor Processing and Acquisition Network - field deployment lessons learned

ABSTRACT Background/Question/Methods In recent years, advances in sensor network technology have ... more ABSTRACT Background/Question/Methods In recent years, advances in sensor network technology have shown great potential to revolutionize environmental data collection. Still, these systems have remained the purview of the engineers and computer scientists who design them, rather than useful tools for the field scientists who need them. Today, there are many data logging options for basic data collection in the field, but scientists are still required to travel to their sites to collect data, and to manually import data into spreadsheets. Few end-to-end systems that can automatically collect and transfer data to a database in the lab exist, and these tend to be overly complex, usually only working with specific sensor hardware. We have designed and built a robust and flexible sensor network called Sensor Processing and Acquisition Network (SPAN). SPAN is hardware agnostic in that it uses commercially available hardware to create a turnkey solution for environmental observation systems. While developing SPAN, our goal was to create an end-to-end system that enabled data collection from various types of sensors in the field and provided a simple way to transfer those data in real-time to a database where they could be shared and analyzed. Results/Conclusions We developed SPAN using extensible building blocks that can be integrated to meet specific scientific requirements. As an open-source and flexible data acquisition architecture, not tied to a particular sensor brand or application, SPAN works with several commonly used data loggers in conjunction with analog, digital, and complex sensors (e.g. imagers and robotic sensors). SPAN allows real-time data access, and provides various options for long haul communication, including cellular and satellite links. This real-time communication enables field scientists to reconfigure sensors remotely and to monitor their status. SPAN offers intuitive user interfaces to configure, control, and monitor deployments from a lab desktop, or in the field, using a laptop or PDA. As such, the system facilitates sensor calibration and system tuning in the field. We employed a deployment driven design, build, and test approach in close collaboration with scientists, who provide requirements and technology verification to drive the design. SPAN has been used for diverse scientific applications throughout the world: from studying mercury cycling in rice paddies in China, to ecological research in the neotropical rainforests of Costa Rica, to monitoring the contamination of salt lakes in Argentina. In this poster we describe the SPAN architecture, experiences working with different scientific applications, and lessons learned from the deployments.

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Research paper thumbnail of Tansley Review: Environmental sensor networks in ecological research

Center For Embedded Network Sensing, 2009

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Research paper thumbnail of Project BudBurst Mobile

ABSTRACT Background/Question/Methods Project Budburst is a citizen science program aimed at engag... more ABSTRACT Background/Question/Methods Project Budburst is a citizen science program aimed at engaging the general public, K-12 as well as more scientifically advanced audiences in documenting how native and ornamental plants are changing their growing season phenology in response to changes in weather, climate and habitats across the United States. The advent of mobile phone technology offers many unprecedented opportunities to enhance the efficiency of our program, to improve data accuracy, and to engage new audiences. In this project we worked together to develop and test new software to evaluate the potential of this technology for citizen science programs aimed at general non-technical audiences, and specifically for Project Budburst. We wished to examine how practical this technology could be in acquiring accurate data for Budburst, and what advantages it offers for our target K-12 and general audiences. Results/Conclusions We were able to demonstrate that it is in fact possible and practical to develop mobile applications that can be used to collect all the data required for Project Budburst. Data can be seamlessly integrated into our online databases, and for users it offers many concrete advantages over previous technologies including much more efficient submission of data, and greater automation and simplification of environmental monitoring.

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Research paper thumbnail of Budburst and leaf area expansion measured with a novel mobile camera system and simple color thresholding

Environmental and Experimental Botany, Mar 1, 2009

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Research paper thumbnail of Overview of Terrestrial Ecology Observation Systems

Center For Embedded Network Sensing, May 12, 2009

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Research paper thumbnail of Epiphytic bromeliad and hosts communities composition along a rainfall gradient in the Yucatán Peninsula

ABSTRACT Families with a high proportion of epiphytic species, like the family Bromeliaceae, are ... more ABSTRACT Families with a high proportion of epiphytic species, like the family Bromeliaceae, are important ecological components in the neotropics contributing to the high biotic diversity present. This is the first study to compare the epiphytic bromeliad and host species composition and factors driving this distribution (microclimate, mesoclimate, canopy structure, host species identities) in dry environments, along five different vegetation types in a precipitation gradient of the Yucatan Peninsula, Mexico. We established plots in coastal sand dune, mangrove, and seasonally dry deciduous, semi-deciduous and sub-perennial forests to characterize the structure and composition of the epiphytic bromeliads and hosts communities, and measured the microclimate (light and VPD) in which bromeliads were growing. Within each plot, all possible hosts were counted, identified and tagged, adult bromeliads also were counted and identified; height of the canopy strata, were the epiphytes were found, was also recorded. The diversity of both host and epiphytic bromeliad species was assessed through species richness and the Shannon-Wiever and Simpson indexes; to distinguish the degree of similarity between the studied sites, we used the Sorensen quantitative index. We found a total of 15 species of epiphytic bromeliads and 98 species of phorophytes belonging to 88 genera. Of these genera, 46.2% had epiphytic bromeliads, suggesting a host preference. The number of bromeliads and hosts (both species and individuals) increased from the driest sites to wetter sites. We found low similarity in species composition of both epiphytic bromeliads and host between vegetation types. Although there is a high seasonal microclimatic variation in sites where most of the epiphytes occurred within the five vegetation types, the horizontal distribution of epiphytic bromeliads seemed to respond to the rainfall gradient and the increase in available niches due to increased canopy height.

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Research paper thumbnail of Digital cameras as environmental sensors (Invited)

Agu Fall Meeting Abstracts, Dec 1, 2010

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Research paper thumbnail of Using Imagers for Scaling Ecological Observations

Center For Embedded Network Sensing, May 12, 2009

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Research paper thumbnail of A Rainforest Ecological Portal

Center For Embedded Network Sensing, 2005

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Research paper thumbnail of TER 0: TEOS: Terrestrial Ecology Observing Systems Overview of Embedded Networked Systems and EMISSARY Tools for Instrument Management and Data Exploration

Center For Embedded Network Sensing, 2006

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Research paper thumbnail of Imagers as sensors: correlating plant CO

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Research paper thumbnail of Project BudBurst Mobile

Background/Question/Methods Project Budburst is a citizen science program aimed at engaging the g... more Background/Question/Methods Project Budburst is a citizen science program aimed at engaging the general public, K-12 as well as more scientifically advanced audiences in documenting how native and ornamental plants are changing their growing season phenology in response to changes in weather, climate and habitats across the United States. The advent of mobile phone technology offers many unprecedented opportunities to enhance the efficiency of our program, to improve data accuracy, and to engage new audiences. In this project we worked together to develop and test new software to evaluate the potential of this technology for citizen science programs aimed at general non-technical audiences, and specifically for Project Budburst. We wished to examine how practical this technology could be in acquiring accurate data for Budburst, and what advantages it offers for our target K-12 and general audiences. Results/Conclusions We were able to demonstrate that it is in fact possible and prac...

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Research paper thumbnail of Use of a digital camera to estimate heterogeneous temperatures and heat flux in a forest understory soil

Background/Question/Methods Soil temperature drives microbial activity, plant germination, rootin... more Background/Question/Methods Soil temperature drives microbial activity, plant germination, rooting, and CO2 fluxes. Soil energy balance is also used in calculations of eddy flux measurements. Because soil surface temperatures can be spatial heterogeneous due to uneven heating from partial shading by an overstory, calculating soil energy balances over large areas and predicting sub-surface temperatures in a forested environment is difficult. Using the analytical models for homogeneously conductive material introduces errors when trying to accurately predict sub-surface temperatures from those at the surface. However, complex patterns of soil surface and sub-surface temperatures due to partial shading by an overstory can be modeled using after the decomposition of the signals into a series of simpler sine waves of different frequencies. Simultaneously, the use of a digital camera to detect areas of solar radiation, coupled with measurements of air temperature, can be used to predict s...

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Research paper thumbnail of Leveraging Internet-connected cameras to create a transcontinental plant phenology monitoring system

Background/Question/Methods Phenology, measured as the timing of recurring biological events and ... more Background/Question/Methods Phenology, measured as the timing of recurring biological events and their environmental drivers, is highly sensitive to changes in environmental conditions and can vary widely across landscapes. Current technologies for observing plant phenology are either (1) ground-based for small-scale, high precision but labor-intensive measurements or (2) remote sensing-based for large-scale but low spatial resolution measurements, often too coarse to detect species and community level responses. We present a novel approach for detecting phenological events across North America utilizing freely-available Internet-connected cameras. We provide methodologies for detecting changes in ‘greenness’ and determining the timing of phenological events from webcam images. In addition, we compare the quality and precision of our detection with that of remote sensing MODIS (Moderate Resolution Imaging Spectroradiometer) products, currently used for large-scale environmental moni...

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Research paper thumbnail of Tracking the rhythm of the seasons in theface of global change: phenological researchin the 21st century

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Size class structure, growth rates, and orientation of the central Andean cushion Azorella compacta

PeerJ, 2015

Azorella compacta (llareta; Apiaceae) forms dense, woody, cushions and characterizes the high ele... more Azorella compacta (llareta; Apiaceae) forms dense, woody, cushions and characterizes the high elevation rocky slopes of the central Andean Altiplano. Field studies of an elevational gradient of A. compacta within Lauca National Park in northern Chile found a reverse J-shape distribution of size classes of individuals with abundant small plants at all elevations. A new elevational limit for A. compacta was established at 5,250 m. A series of cushions marked 14 years earlier showed either slight shrinkage or small degrees of growth up to 2.2 cm yr(-1). Despite their irregularity in growth, cushions of A. compacta show a strong orientation, centered on a north-facing aspect and angle of about 20° from horizontal. This exposure to maximize solar irradiance closely matches previous observations of a population favoring north-facing slopes at a similar angle. Populations of A. compacta appear to be stable, or even expanding, with young plants abundant.

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Research paper thumbnail of Imagers as sensors

Proceedings of the 4th workshop on Data management for sensor networks in conjunction with 33rd International Conference on Very Large Data Bases - DMSN '07, 2007

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Research paper thumbnail of Reductions in Indoor Black Carbon Concentrations from Improved Biomass Stoves in Rural India

Environmental science & technology, Jan 4, 2015

Deployment of improved biomass burning cookstoves is recognized as a black carbon (BC) mitigation... more Deployment of improved biomass burning cookstoves is recognized as a black carbon (BC) mitigation measure that has the potential to achieve health benefits and climate co-benefits. Yet, few field based studies document BC concentration reductions (and resulting human exposure) resulting from improved stove usage. In this paper, data are presented from 277 real-world cooking sessions collected during two field studies to document the impacts on indoor BC concentrations inside village kitchens as a result of switching from traditional stoves to improved forced draft (FD) stoves. Data collection utilized new low-cost cellphone methods to monitor BC, cooking duration, and fuel consumption. A cross sectional study recorded a reduction of 36% in BC during cooking sessions. An independent paired sample study demonstrated a statistically significant reduction of 40% in 24-hour BC concentrations when traditional stoves were replaced with FD stoves. Reductions observed in these field studies ...

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Research paper thumbnail of Root Water Uptake, Leaf Water Storage and Gas Exchange of a Desert Succulent: Implications for Root System Redundancy

Annals of Botany

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Tracking the rhythm of the seasons in theface of global change: phenological researchin the 21st century

Bookmarks Related papers MentionsView impact

Research paper thumbnail of SPAN: A Sensor Processing and Acquisition Network - field deployment lessons learned

ABSTRACT Background/Question/Methods In recent years, advances in sensor network technology have ... more ABSTRACT Background/Question/Methods In recent years, advances in sensor network technology have shown great potential to revolutionize environmental data collection. Still, these systems have remained the purview of the engineers and computer scientists who design them, rather than useful tools for the field scientists who need them. Today, there are many data logging options for basic data collection in the field, but scientists are still required to travel to their sites to collect data, and to manually import data into spreadsheets. Few end-to-end systems that can automatically collect and transfer data to a database in the lab exist, and these tend to be overly complex, usually only working with specific sensor hardware. We have designed and built a robust and flexible sensor network called Sensor Processing and Acquisition Network (SPAN). SPAN is hardware agnostic in that it uses commercially available hardware to create a turnkey solution for environmental observation systems. While developing SPAN, our goal was to create an end-to-end system that enabled data collection from various types of sensors in the field and provided a simple way to transfer those data in real-time to a database where they could be shared and analyzed. Results/Conclusions We developed SPAN using extensible building blocks that can be integrated to meet specific scientific requirements. As an open-source and flexible data acquisition architecture, not tied to a particular sensor brand or application, SPAN works with several commonly used data loggers in conjunction with analog, digital, and complex sensors (e.g. imagers and robotic sensors). SPAN allows real-time data access, and provides various options for long haul communication, including cellular and satellite links. This real-time communication enables field scientists to reconfigure sensors remotely and to monitor their status. SPAN offers intuitive user interfaces to configure, control, and monitor deployments from a lab desktop, or in the field, using a laptop or PDA. As such, the system facilitates sensor calibration and system tuning in the field. We employed a deployment driven design, build, and test approach in close collaboration with scientists, who provide requirements and technology verification to drive the design. SPAN has been used for diverse scientific applications throughout the world: from studying mercury cycling in rice paddies in China, to ecological research in the neotropical rainforests of Costa Rica, to monitoring the contamination of salt lakes in Argentina. In this poster we describe the SPAN architecture, experiences working with different scientific applications, and lessons learned from the deployments.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Tansley Review: Environmental sensor networks in ecological research

Center For Embedded Network Sensing, 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Project BudBurst Mobile

ABSTRACT Background/Question/Methods Project Budburst is a citizen science program aimed at engag... more ABSTRACT Background/Question/Methods Project Budburst is a citizen science program aimed at engaging the general public, K-12 as well as more scientifically advanced audiences in documenting how native and ornamental plants are changing their growing season phenology in response to changes in weather, climate and habitats across the United States. The advent of mobile phone technology offers many unprecedented opportunities to enhance the efficiency of our program, to improve data accuracy, and to engage new audiences. In this project we worked together to develop and test new software to evaluate the potential of this technology for citizen science programs aimed at general non-technical audiences, and specifically for Project Budburst. We wished to examine how practical this technology could be in acquiring accurate data for Budburst, and what advantages it offers for our target K-12 and general audiences. Results/Conclusions We were able to demonstrate that it is in fact possible and practical to develop mobile applications that can be used to collect all the data required for Project Budburst. Data can be seamlessly integrated into our online databases, and for users it offers many concrete advantages over previous technologies including much more efficient submission of data, and greater automation and simplification of environmental monitoring.

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Research paper thumbnail of Budburst and leaf area expansion measured with a novel mobile camera system and simple color thresholding

Environmental and Experimental Botany, Mar 1, 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Overview of Terrestrial Ecology Observation Systems

Center For Embedded Network Sensing, May 12, 2009

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Research paper thumbnail of Epiphytic bromeliad and hosts communities composition along a rainfall gradient in the Yucatán Peninsula

ABSTRACT Families with a high proportion of epiphytic species, like the family Bromeliaceae, are ... more ABSTRACT Families with a high proportion of epiphytic species, like the family Bromeliaceae, are important ecological components in the neotropics contributing to the high biotic diversity present. This is the first study to compare the epiphytic bromeliad and host species composition and factors driving this distribution (microclimate, mesoclimate, canopy structure, host species identities) in dry environments, along five different vegetation types in a precipitation gradient of the Yucatan Peninsula, Mexico. We established plots in coastal sand dune, mangrove, and seasonally dry deciduous, semi-deciduous and sub-perennial forests to characterize the structure and composition of the epiphytic bromeliads and hosts communities, and measured the microclimate (light and VPD) in which bromeliads were growing. Within each plot, all possible hosts were counted, identified and tagged, adult bromeliads also were counted and identified; height of the canopy strata, were the epiphytes were found, was also recorded. The diversity of both host and epiphytic bromeliad species was assessed through species richness and the Shannon-Wiever and Simpson indexes; to distinguish the degree of similarity between the studied sites, we used the Sorensen quantitative index. We found a total of 15 species of epiphytic bromeliads and 98 species of phorophytes belonging to 88 genera. Of these genera, 46.2% had epiphytic bromeliads, suggesting a host preference. The number of bromeliads and hosts (both species and individuals) increased from the driest sites to wetter sites. We found low similarity in species composition of both epiphytic bromeliads and host between vegetation types. Although there is a high seasonal microclimatic variation in sites where most of the epiphytes occurred within the five vegetation types, the horizontal distribution of epiphytic bromeliads seemed to respond to the rainfall gradient and the increase in available niches due to increased canopy height.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Digital cameras as environmental sensors (Invited)

Agu Fall Meeting Abstracts, Dec 1, 2010

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Using Imagers for Scaling Ecological Observations

Center For Embedded Network Sensing, May 12, 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A Rainforest Ecological Portal

Center For Embedded Network Sensing, 2005

Bookmarks Related papers MentionsView impact

Research paper thumbnail of TER 0: TEOS: Terrestrial Ecology Observing Systems Overview of Embedded Networked Systems and EMISSARY Tools for Instrument Management and Data Exploration

Center For Embedded Network Sensing, 2006

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Imagers as sensors: correlating plant CO

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Project BudBurst Mobile

Background/Question/Methods Project Budburst is a citizen science program aimed at engaging the g... more Background/Question/Methods Project Budburst is a citizen science program aimed at engaging the general public, K-12 as well as more scientifically advanced audiences in documenting how native and ornamental plants are changing their growing season phenology in response to changes in weather, climate and habitats across the United States. The advent of mobile phone technology offers many unprecedented opportunities to enhance the efficiency of our program, to improve data accuracy, and to engage new audiences. In this project we worked together to develop and test new software to evaluate the potential of this technology for citizen science programs aimed at general non-technical audiences, and specifically for Project Budburst. We wished to examine how practical this technology could be in acquiring accurate data for Budburst, and what advantages it offers for our target K-12 and general audiences. Results/Conclusions We were able to demonstrate that it is in fact possible and prac...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Use of a digital camera to estimate heterogeneous temperatures and heat flux in a forest understory soil

Background/Question/Methods Soil temperature drives microbial activity, plant germination, rootin... more Background/Question/Methods Soil temperature drives microbial activity, plant germination, rooting, and CO2 fluxes. Soil energy balance is also used in calculations of eddy flux measurements. Because soil surface temperatures can be spatial heterogeneous due to uneven heating from partial shading by an overstory, calculating soil energy balances over large areas and predicting sub-surface temperatures in a forested environment is difficult. Using the analytical models for homogeneously conductive material introduces errors when trying to accurately predict sub-surface temperatures from those at the surface. However, complex patterns of soil surface and sub-surface temperatures due to partial shading by an overstory can be modeled using after the decomposition of the signals into a series of simpler sine waves of different frequencies. Simultaneously, the use of a digital camera to detect areas of solar radiation, coupled with measurements of air temperature, can be used to predict s...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Leveraging Internet-connected cameras to create a transcontinental plant phenology monitoring system

Background/Question/Methods Phenology, measured as the timing of recurring biological events and ... more Background/Question/Methods Phenology, measured as the timing of recurring biological events and their environmental drivers, is highly sensitive to changes in environmental conditions and can vary widely across landscapes. Current technologies for observing plant phenology are either (1) ground-based for small-scale, high precision but labor-intensive measurements or (2) remote sensing-based for large-scale but low spatial resolution measurements, often too coarse to detect species and community level responses. We present a novel approach for detecting phenological events across North America utilizing freely-available Internet-connected cameras. We provide methodologies for detecting changes in ‘greenness’ and determining the timing of phenological events from webcam images. In addition, we compare the quality and precision of our detection with that of remote sensing MODIS (Moderate Resolution Imaging Spectroradiometer) products, currently used for large-scale environmental moni...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Tracking the rhythm of the seasons in theface of global change: phenological researchin the 21st century

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Size class structure, growth rates, and orientation of the central Andean cushion Azorella compacta

PeerJ, 2015

Azorella compacta (llareta; Apiaceae) forms dense, woody, cushions and characterizes the high ele... more Azorella compacta (llareta; Apiaceae) forms dense, woody, cushions and characterizes the high elevation rocky slopes of the central Andean Altiplano. Field studies of an elevational gradient of A. compacta within Lauca National Park in northern Chile found a reverse J-shape distribution of size classes of individuals with abundant small plants at all elevations. A new elevational limit for A. compacta was established at 5,250 m. A series of cushions marked 14 years earlier showed either slight shrinkage or small degrees of growth up to 2.2 cm yr(-1). Despite their irregularity in growth, cushions of A. compacta show a strong orientation, centered on a north-facing aspect and angle of about 20° from horizontal. This exposure to maximize solar irradiance closely matches previous observations of a population favoring north-facing slopes at a similar angle. Populations of A. compacta appear to be stable, or even expanding, with young plants abundant.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Imagers as sensors

Proceedings of the 4th workshop on Data management for sensor networks in conjunction with 33rd International Conference on Very Large Data Bases - DMSN '07, 2007

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Reductions in Indoor Black Carbon Concentrations from Improved Biomass Stoves in Rural India

Environmental science & technology, Jan 4, 2015

Deployment of improved biomass burning cookstoves is recognized as a black carbon (BC) mitigation... more Deployment of improved biomass burning cookstoves is recognized as a black carbon (BC) mitigation measure that has the potential to achieve health benefits and climate co-benefits. Yet, few field based studies document BC concentration reductions (and resulting human exposure) resulting from improved stove usage. In this paper, data are presented from 277 real-world cooking sessions collected during two field studies to document the impacts on indoor BC concentrations inside village kitchens as a result of switching from traditional stoves to improved forced draft (FD) stoves. Data collection utilized new low-cost cellphone methods to monitor BC, cooking duration, and fuel consumption. A cross sectional study recorded a reduction of 36% in BC during cooking sessions. An independent paired sample study demonstrated a statistically significant reduction of 40% in 24-hour BC concentrations when traditional stoves were replaced with FD stoves. Reductions observed in these field studies ...

Bookmarks Related papers MentionsView impact