As climate has warmed in recent decades, Alaska has experienced a variety of high-impact extreme events that include heat waves, wildfires, coastal storms and freezing rain. Because the warming is projected to continu...As climate has warmed in recent decades, Alaska has experienced a variety of high-impact extreme events that include heat waves, wildfires, coastal storms and freezing rain. Because the warming is projected to continue, it is essential to consider future changes when planning adaptation actions and building resilience. In this study, we synthesize information on future changes in extreme events in Alaska from an ensemble of regional climate model simulations performed as part of Arctic-CORDEX (Coordinated Regional Climate Downscaling Experiment). A set of 13 extreme event indices, based on those developed by the World Climate Research Programme’s Expert Team on Climate Change Detection and Indices (ETCCDI), are evaluated from the Arctic-CORDEX output for Alaska. Of the 13 indices, six pertain to temperature, five to total precipitation, one to wind and one to snow. The results for locations in seven different climate zones of Alaska include large increases (5˚C - 10˚C) in the temperature thresholds for the five hottest and coldest days of the year, and large increases in warm spell duration and decreases in cold spell duration. Changes in the cold day temperature threshold are generally larger than the changes in the hot day temperature threshold, consistent with the projections of a stronger warming in winter than in summer in Alaska yearly maximum 1-day and 5-day precipitation amounts as well as the yearly number of consecutive wet days are projected to increase at all locations. The indices for heavy snow days and high-wind days show mixed changes, although the results indicate increases in heavy snow days at the more northern locations and increases in windy days at coastal locations. The changes in the extreme event indices continue through 2100 under the higher-emission (RCP 8.5) emission scenario, while the changes generally stabilize under the lower-emission (RCP 4.5) scenario. .展开更多
This paper combines a review of recent advances in quantum thermodynamics, including work on objective collapse (Zurek’s quantum Darwinism) and quantum gravity (Verlinde’s quantum gravity explanation), with a redefi...This paper combines a review of recent advances in quantum thermodynamics, including work on objective collapse (Zurek’s quantum Darwinism) and quantum gravity (Verlinde’s quantum gravity explanation), with a redefinition of entropy generation as systems’ change process. These concepts are used as systems’ behaviour analysis tools to allow us to revisit Hartle and Hawking’s 1983 quantum universe and develop a hypothesis for how physically a universe starting in a quantum state could evolve into our current universe, based on systems analysis. The outcome of this analysis raises a question: do we already have the elements of a “theory of everything” hiding in plain sight within recent advances in quantum thermodynamics?展开更多
State Highway 35 (SH35) connects Opotiki to Gisborne along the Raukumara Peninsula in the North Island, New Zealand. This corridor passes through an area which is prone to landslides, especially during the wet season....State Highway 35 (SH35) connects Opotiki to Gisborne along the Raukumara Peninsula in the North Island, New Zealand. This corridor passes through an area which is prone to landslides, especially during the wet season. This, in turn, influences the traffic and has detrimental effects to the local economy, as it is dependent mainly on tourism and commercial transportation by road. This paper will focus on the landslides which occurred between June and September 2018, within the Bay of Plenty East on the north side of the Raukumara Peninsula. The paper will analyze both the nature and triggering mechanisms behind these landslides. As the landslides occur in the wet season, rainfall has been commonly considered the main trigger. However, the paper will argue that vehicle vibrations have been contributing to the instability of the slopes within the Bay of Plenty East. This paper will be instrumental in developing future transportation strategies in this part of the North Island.展开更多
Roof bolting has long been used in underground mines across the world to provide ground support.Modern roof bolts are cheap and easy to install with the use of specialized machines as a part of the production cycle. L...Roof bolting has long been used in underground mines across the world to provide ground support.Modern roof bolts are cheap and easy to install with the use of specialized machines as a part of the production cycle. Lhoist North America’s Crab Orchard Mine is an underground room and pillar limestone mine that uses mechanically anchored roof bolts for ground support. The mine currently employs two different roof bolting patterns: a standard 1.5 × 1.5 m pattern, and another 0.8 × 0.8 m pattern for use in areas with particularly hazardous roof conditions. The purpose of this study is to evaluate the relative effectiveness of each bolting pattern. A series of numerical models were created using Roc Science’s RS2. The models were based on a symmetrical section of the mine at its deepest point, and were modeled using generalized Hoek-Brown failure criterion along with a discrete fracture network. A series of sensitivity analyses were performed on the models by varying parameters such as joint friction angle, crack persistence, joint randomization, and tensile strength of the limestone. Based on the results of the original models and sensitivity analyses, it appeared that the standard bolting pattern provided sufficient roof support capacity under almost all the expected conditions at the mine, since safety factors below the design value of 1.5 were only found for individual bolts in a few of the worst test cases considered.These results can help improve the mine’s productivity and reduce operating costs without compromising safety.展开更多
In their ranges on east and south coasts of the Americas as well as their established invasions in the Adriatic and Baltic,blue crabs,Callinectes sapidus,inhabit estuaries,sounds and coastal oceans and are commerciall...In their ranges on east and south coasts of the Americas as well as their established invasions in the Adriatic and Baltic,blue crabs,Callinectes sapidus,inhabit estuaries,sounds and coastal oceans and are commercially and ecologically important.How crabs move in response to physical variables is important to management.We monitored life stages at canal control structures,assessed gender ratios with recreational crabbing,learned from crabbers,and studied movements of tagged crabs in a canal connecting Lake Mattamuskeet to the Pamlico sound.Juveniles enter the lake through two of 4 canals connecting to the sounds.Females migrate out through one canal.The lake standing population is about 70% male.Movements of 240 crabs in August 2012 and 102 crabs in October 2014 were quantified using RFID tags with co-located meteorological and oceanographic devices.Non-spawning females and males are nomadic.Crabs released in the canal move in response to changes in water depth and go with the flow,toward the Pamlico Sound(summer 76% and fall 78%).What crabbers describe as a fall migration appears to be concentration of crabs in warmer deeper canals and then southern movement with flow generated by strong north winds.To be effective,management strategies like migratory corridors require understanding of crab movements.展开更多
Extensive field tests of non-intrusive sensors for traffic volume, speed and classification detection were conducted under a variety of traffic composition and road width conditions. The accuracy challenges of utilizi...Extensive field tests of non-intrusive sensors for traffic volume, speed and classification detection were conducted under a variety of traffic composition and road width conditions. The accuracy challenges of utilizing non-intrusive sensors for traffic data collection were studied. Both fixed and portable sensors with infrared, microwave and image recognition technologies were tested. Most sensors obtained accurate or fairly accurate measurements of volume and speed, but vehicle classification counts were problematic even when classes were reduced to 3 to 5 compared to FHWA’s 13-class standard scheme.展开更多
Accurate and reliable groundwater contaminant source characterization with limited contaminant concentration monitoring measurement data remains a challenging problem. This study presents an illustrative application o...Accurate and reliable groundwater contaminant source characterization with limited contaminant concentration monitoring measurement data remains a challenging problem. This study presents an illustrative application of developed methodologies to a real-life contaminated aquifer. The source characterization and optimal monitoring network design methodologies are used sequentially for a contaminated aquifer site located in New South Wales, Australia. Performance of the integrated optimal source characterization methodology combining linked simulation-optimization, fractal singularity mapping technique (FSMT) and Pareto optimal solutions is evaluated. This study presents an integrated application of optimal source characterization with spatiotemporal concentration measurement data obtained from sequentially designed monitoring networks. The proposed sequential source characterization and monitoring network design methodology shows efficiency in identifying the unknown source characteristics. The designed monitoring network achieves comparable efficiency and accuracy utilizing much smaller number of monitoring locations as compared to a more ideal scenario where concentration measurements from a very large number of widespread monitoring wells are available. The proposed methodology is potentially useful for efficient characterization of unknown contaminant sources in a complex contaminated aquifer site, where very little initial concentration measurement data are available. The illustrative application of the methodology to a real-life contaminated aquifer site demonstrates the capability and efficiency of the proposed methodology.展开更多
This paper presents an analytical approach for estimating frictional resistance to pipe movement at soil and external pipe surface of buried coated pressurized steel pipes relative to the internal thrust force.The pro...This paper presents an analytical approach for estimating frictional resistance to pipe movement at soil and external pipe surface of buried coated pressurized steel pipes relative to the internal thrust force.The proposed analytical method was developed based on 36 experiments,which involved three coating types(cement mortar(CM),polyurethane type-I(PT-I),prefabricated plastic tape(PPT))on pipes’surfaces,three different soils(pea-gravel(PG),sand(S),silty-clay(SC)),and four simulated over burden depths above the pipe’s crown.Investigation showed frictional resistance decreased with increasing over burden depth above the pipe’s crown.The degree of frictional resistance at the pipe-soil interface was found to be in the order of PG>SC>S for all coating variations and overburden depths.CM coated pipe buried in all three types of soil produced significantly higher frictional resistance as compared to other coating types.Based on experimental data,the developed analytical introduced a dimensionless factor“Z”,which included effects of types of coatings,soil,and overburden depths for simplified rapid calculation.Analysis showed that the method provided a better prediction of frictional resistance forces,in comparison to previous analytical methods,which were barely close in predicting friction resistance for different coating variations,soil types,and overburden depths.Friction resistance force values reported herein could be considered conservative.展开更多
Building envelope is the sole interface with outdoors that can lie in the level of integrating control strategies to enhance occupant's comfort and building performance. However, in the literature, there is still ...Building envelope is the sole interface with outdoors that can lie in the level of integrating control strategies to enhance occupant's comfort and building performance. However, in the literature, there is still a lack of multi-purpose control strategies which can balance diverse and antagonistic aspects of occupant comfort while keeping the building energy consumption under control. Therefore, this research proposed an integrated simulation-based workflow using EnergyPlus and Python-based package, OpyPlus, to adjust a roller shade for single occupied office space in a hot and arid climate. The developed system aims to improve both occupant's visual and thermal comfort considering daylight level, potential glare at occupant's field of view, view to outdoor satisfaction, and Fanger PMV method, and then, managing the HVAC system in favor of enhancing building energy efficiency. Furthermore, the controller's performance was compared to multiple fixed controls and another multi-agent control scenario from visual and thermal comfort and energy performance perspectives. The developed control system could perform effectively to provide a glare-free view and higher thermally comfortable indoor environment by 99% for the occupant across the year, while improving the heating and cooling loads. The research provides novel insights and potential future integrations for facade designers and building operators.展开更多
文摘As climate has warmed in recent decades, Alaska has experienced a variety of high-impact extreme events that include heat waves, wildfires, coastal storms and freezing rain. Because the warming is projected to continue, it is essential to consider future changes when planning adaptation actions and building resilience. In this study, we synthesize information on future changes in extreme events in Alaska from an ensemble of regional climate model simulations performed as part of Arctic-CORDEX (Coordinated Regional Climate Downscaling Experiment). A set of 13 extreme event indices, based on those developed by the World Climate Research Programme’s Expert Team on Climate Change Detection and Indices (ETCCDI), are evaluated from the Arctic-CORDEX output for Alaska. Of the 13 indices, six pertain to temperature, five to total precipitation, one to wind and one to snow. The results for locations in seven different climate zones of Alaska include large increases (5˚C - 10˚C) in the temperature thresholds for the five hottest and coldest days of the year, and large increases in warm spell duration and decreases in cold spell duration. Changes in the cold day temperature threshold are generally larger than the changes in the hot day temperature threshold, consistent with the projections of a stronger warming in winter than in summer in Alaska yearly maximum 1-day and 5-day precipitation amounts as well as the yearly number of consecutive wet days are projected to increase at all locations. The indices for heavy snow days and high-wind days show mixed changes, although the results indicate increases in heavy snow days at the more northern locations and increases in windy days at coastal locations. The changes in the extreme event indices continue through 2100 under the higher-emission (RCP 8.5) emission scenario, while the changes generally stabilize under the lower-emission (RCP 4.5) scenario. .
文摘This paper combines a review of recent advances in quantum thermodynamics, including work on objective collapse (Zurek’s quantum Darwinism) and quantum gravity (Verlinde’s quantum gravity explanation), with a redefinition of entropy generation as systems’ change process. These concepts are used as systems’ behaviour analysis tools to allow us to revisit Hartle and Hawking’s 1983 quantum universe and develop a hypothesis for how physically a universe starting in a quantum state could evolve into our current universe, based on systems analysis. The outcome of this analysis raises a question: do we already have the elements of a “theory of everything” hiding in plain sight within recent advances in quantum thermodynamics?
文摘State Highway 35 (SH35) connects Opotiki to Gisborne along the Raukumara Peninsula in the North Island, New Zealand. This corridor passes through an area which is prone to landslides, especially during the wet season. This, in turn, influences the traffic and has detrimental effects to the local economy, as it is dependent mainly on tourism and commercial transportation by road. This paper will focus on the landslides which occurred between June and September 2018, within the Bay of Plenty East on the north side of the Raukumara Peninsula. The paper will analyze both the nature and triggering mechanisms behind these landslides. As the landslides occur in the wet season, rainfall has been commonly considered the main trigger. However, the paper will argue that vehicle vibrations have been contributing to the instability of the slopes within the Bay of Plenty East. This paper will be instrumental in developing future transportation strategies in this part of the North Island.
基金The research conducted for this study was funded by the National Institute for Occupational Safety and Health(NIOSH)under Grant Number 200-2016-90154.
文摘Roof bolting has long been used in underground mines across the world to provide ground support.Modern roof bolts are cheap and easy to install with the use of specialized machines as a part of the production cycle. Lhoist North America’s Crab Orchard Mine is an underground room and pillar limestone mine that uses mechanically anchored roof bolts for ground support. The mine currently employs two different roof bolting patterns: a standard 1.5 × 1.5 m pattern, and another 0.8 × 0.8 m pattern for use in areas with particularly hazardous roof conditions. The purpose of this study is to evaluate the relative effectiveness of each bolting pattern. A series of numerical models were created using Roc Science’s RS2. The models were based on a symmetrical section of the mine at its deepest point, and were modeled using generalized Hoek-Brown failure criterion along with a discrete fracture network. A series of sensitivity analyses were performed on the models by varying parameters such as joint friction angle, crack persistence, joint randomization, and tensile strength of the limestone. Based on the results of the original models and sensitivity analyses, it appeared that the standard bolting pattern provided sufficient roof support capacity under almost all the expected conditions at the mine, since safety factors below the design value of 1.5 were only found for individual bolts in a few of the worst test cases considered.These results can help improve the mine’s productivity and reduce operating costs without compromising safety.
文摘In their ranges on east and south coasts of the Americas as well as their established invasions in the Adriatic and Baltic,blue crabs,Callinectes sapidus,inhabit estuaries,sounds and coastal oceans and are commercially and ecologically important.How crabs move in response to physical variables is important to management.We monitored life stages at canal control structures,assessed gender ratios with recreational crabbing,learned from crabbers,and studied movements of tagged crabs in a canal connecting Lake Mattamuskeet to the Pamlico sound.Juveniles enter the lake through two of 4 canals connecting to the sounds.Females migrate out through one canal.The lake standing population is about 70% male.Movements of 240 crabs in August 2012 and 102 crabs in October 2014 were quantified using RFID tags with co-located meteorological and oceanographic devices.Non-spawning females and males are nomadic.Crabs released in the canal move in response to changes in water depth and go with the flow,toward the Pamlico Sound(summer 76% and fall 78%).What crabbers describe as a fall migration appears to be concentration of crabs in warmer deeper canals and then southern movement with flow generated by strong north winds.To be effective,management strategies like migratory corridors require understanding of crab movements.
文摘Extensive field tests of non-intrusive sensors for traffic volume, speed and classification detection were conducted under a variety of traffic composition and road width conditions. The accuracy challenges of utilizing non-intrusive sensors for traffic data collection were studied. Both fixed and portable sensors with infrared, microwave and image recognition technologies were tested. Most sensors obtained accurate or fairly accurate measurements of volume and speed, but vehicle classification counts were problematic even when classes were reduced to 3 to 5 compared to FHWA’s 13-class standard scheme.
文摘Accurate and reliable groundwater contaminant source characterization with limited contaminant concentration monitoring measurement data remains a challenging problem. This study presents an illustrative application of developed methodologies to a real-life contaminated aquifer. The source characterization and optimal monitoring network design methodologies are used sequentially for a contaminated aquifer site located in New South Wales, Australia. Performance of the integrated optimal source characterization methodology combining linked simulation-optimization, fractal singularity mapping technique (FSMT) and Pareto optimal solutions is evaluated. This study presents an integrated application of optimal source characterization with spatiotemporal concentration measurement data obtained from sequentially designed monitoring networks. The proposed sequential source characterization and monitoring network design methodology shows efficiency in identifying the unknown source characteristics. The designed monitoring network achieves comparable efficiency and accuracy utilizing much smaller number of monitoring locations as compared to a more ideal scenario where concentration measurements from a very large number of widespread monitoring wells are available. The proposed methodology is potentially useful for efficient characterization of unknown contaminant sources in a complex contaminated aquifer site, where very little initial concentration measurement data are available. The illustrative application of the methodology to a real-life contaminated aquifer site demonstrates the capability and efficiency of the proposed methodology.
文摘This paper presents an analytical approach for estimating frictional resistance to pipe movement at soil and external pipe surface of buried coated pressurized steel pipes relative to the internal thrust force.The proposed analytical method was developed based on 36 experiments,which involved three coating types(cement mortar(CM),polyurethane type-I(PT-I),prefabricated plastic tape(PPT))on pipes’surfaces,three different soils(pea-gravel(PG),sand(S),silty-clay(SC)),and four simulated over burden depths above the pipe’s crown.Investigation showed frictional resistance decreased with increasing over burden depth above the pipe’s crown.The degree of frictional resistance at the pipe-soil interface was found to be in the order of PG>SC>S for all coating variations and overburden depths.CM coated pipe buried in all three types of soil produced significantly higher frictional resistance as compared to other coating types.Based on experimental data,the developed analytical introduced a dimensionless factor“Z”,which included effects of types of coatings,soil,and overburden depths for simplified rapid calculation.Analysis showed that the method provided a better prediction of frictional resistance forces,in comparison to previous analytical methods,which were barely close in predicting friction resistance for different coating variations,soil types,and overburden depths.Friction resistance force values reported herein could be considered conservative.
文摘Building envelope is the sole interface with outdoors that can lie in the level of integrating control strategies to enhance occupant's comfort and building performance. However, in the literature, there is still a lack of multi-purpose control strategies which can balance diverse and antagonistic aspects of occupant comfort while keeping the building energy consumption under control. Therefore, this research proposed an integrated simulation-based workflow using EnergyPlus and Python-based package, OpyPlus, to adjust a roller shade for single occupied office space in a hot and arid climate. The developed system aims to improve both occupant's visual and thermal comfort considering daylight level, potential glare at occupant's field of view, view to outdoor satisfaction, and Fanger PMV method, and then, managing the HVAC system in favor of enhancing building energy efficiency. Furthermore, the controller's performance was compared to multiple fixed controls and another multi-agent control scenario from visual and thermal comfort and energy performance perspectives. The developed control system could perform effectively to provide a glare-free view and higher thermally comfortable indoor environment by 99% for the occupant across the year, while improving the heating and cooling loads. The research provides novel insights and potential future integrations for facade designers and building operators.
