Heat Recovery Ventilators(HRVs)are essential for improving indoor air quality(IAQ)and reducing energy consumption in residential buildings situated in cold climates.This study considers the efficiency and performance ...Heat Recovery Ventilators(HRVs)are essential for improving indoor air quality(IAQ)and reducing energy consumption in residential buildings situated in cold climates.This study considers the efficiency and performance optimization of HRVs under cold climatic conditions,where conventional ventilation systems increase heat loss.A comprehensive numerical model was developed using COMSOL Multiphysics,integrating fluid dynamics,heat transfer,and solid mechanics to evaluate the thermal efficiency and structural integrity of an HRV system.The methodology employed a detailed geometry with tetrahedral elements,temperature-dependent material properties,and coupled governing equations solved under Tehran-specific boundary conditions.A multi-objective optimization was implemented in the framework of the Nelder-Mead simplex algorithm,targeting the maximization of the average outlet temperature and minimization of the maximum von Mises thermal stress,with inlet flow velocity as the design variable(range:0.5–1.2m/s).Results indicate an optimal velocity of 0.51563 m/s,achieving an average outlet temperature of 289.44 K and maximum von Mises stress of 221 MPa,validated through mesh independence and detailed contour analyses of temperature,velocity,and stress distributions.展开更多
Constructed wetlands（CWs） have been successfully used for treating various wastewaters for decades and have been identified as a sustainable wastewater management option worldwide.However,the application of CW for w...Constructed wetlands（CWs） have been successfully used for treating various wastewaters for decades and have been identified as a sustainable wastewater management option worldwide.However,the application of CW for wastewater treatment in frigid climate presents special challenges.Wetland treatment of wastewater relies largely on biological processes,and reliable treatment is often a function of climate conditions.To date,the rate of adoption of wetland technology for wastewater treatment in cold regions has been slow and there are relatively few published reports on CW applications in cold climate.This paper therefore highlights the practice and applications of treatment wetlands in cold climate.A comprehensive review of the effectiveness of contaminant removal in different wetland systems including：（1） free water surface（FWS） CWs;（2） subsurface flow（SSF） CWs;and（3） hybrid wetland systems,is presented.The emphasis of this review is also placed on the influence of cold weather conditions on the removal efficacies of different contaminants.The strategies of wetland design and operation for performance intensification,such as the presence of plant,operational mode,effluent recirculation,artificial aeration and in-series design,which are crucial to achieve the sustainable treatment performance in cold climate,are also discussed.This study is conducive to further research for the understanding of CW design and treatment performance in cold climate.展开更多
In the process of mining coal resources, the mining site needs crushing, transportation and hydraulic equipment. Efficient use of mechanical equipment can ensure the stability and safety of the whole mining work to th...In the process of mining coal resources, the mining site needs crushing, transportation and hydraulic equipment. Efficient use of mechanical equipment can ensure the stability and safety of the whole mining work to the greatest extent. The crushing, transportation and hydraulic equipment have high requirements on the welding process, and the whole welding process is complicated. The quality of welding directly affects the safety and service life of equipment.展开更多
The global shift towards sustainable and environmentally friendly transportation options has led to the increasing adoption of electric buses(Ebuses).To optimize the deployment and operational strategies of Ebuses,it ...The global shift towards sustainable and environmentally friendly transportation options has led to the increasing adoption of electric buses(Ebuses).To optimize the deployment and operational strategies of Ebuses,it is imperative to accurately predict their energy consumption under varying conditions,particularly in cold climates where battery life is typically degraded.The exploration of this aspect within the Canadian context has been limited.In addition,we have found that existing models in the literature perform poorly in the Canadian environment,giving rise to the need for new models using Canadian data.This paper focuses on the development,comparison,and evaluation of various data-driven models designed to predict the energy consumption of different Ebuses with different heating technologies under a wide range of climate conditions.We specifically use Canadian data as a good representative of cold climates in general.The results show that the performance of the different bus types varies substantially under the exact same conditions.In addition,tree-based family of models proves to be the most suitable approach for predicting the Ebus consumption rate.The results indicate that the Random Forest method emerges as the superior choice for predicting the energy consumption rate,with a resulting mean absolute error of 0.09–0.1 kWh/km observed across the different models.Furthermore,SHAP analysis shows that the main variables influencing the energy consumption rate depend on the type of heating system(using the battery for heating or using an auxiliary system that utilizes diesel for heating)adopted.展开更多
The school commuting path is an important space for elementary school students to engage with society and nature.The design of these paths reflects concerns for children's rights and healthy development and has cr...The school commuting path is an important space for elementary school students to engage with society and nature.The design of these paths reflects concerns for children's rights and healthy development and has crucial impacts on creating supportive environments for children.The scientific evaluation of the child-friendly level of school commuting paths forms a significant basis for shaping child-friendly environments and promoting the comprehensive development of children.Additionally,due to the unique climatic conditions,cold climate cities excert a distinct impact on children's behavior,activities,and physical and mental health compared to cities in other climate zones.This study,from the perspective of child-friendliness,constructs an evaluation system for school commuting paths in cold climate cities,based on children's behavioral characteristics and environmental needs.The system includes dimensions such as safety,diversity,and comfort.With children and their caregivers as the evaluators,the study applies structural equation modeling to assign weights to the various dimension indicators in the evaluation system.The research focuses on five elementary schools in the Nangang District of Harbin City,using methods such as machine learning,space syntax,and field surveys to assess the school commuting paths.Building upon these findings,the study constructs the characteristic profile of the commuting paths and proposes evidence-based control and optimization strategies for different types of school commuting paths in cold climate cities from a child-friendly perspective.展开更多
Bioretention is a popular best management practice of low impact development that el/ecUvely restores urban hydrologic characteristics to those ofpredevelopment and improves water quality prior to conveyance to surfac...Bioretention is a popular best management practice of low impact development that el/ecUvely restores urban hydrologic characteristics to those ofpredevelopment and improves water quality prior to conveyance to surface waters. This is achieved by utilizing an engineered system containing a surface layer of mulch, a thick soil media often amended with a variety of materials to improve water oualitv, a variety of vegetation, and underdrains, depending on the surrounding soil characteristics.Bioretention systems have been studied quite extensively for warm climate applications, but ctata strongly supporting their long-tema efficacy and application in cold climates is sparse. Although it is apparent that biorelention is an effective stormwater management system, its design in cold climate needs further research. Existing cold climate research has shown that coarser media is required to prevent concrete frost from forming. For spring, summer and fall seasons, if sufficient permeability exists to drain the system prior to freezing, peak flow and volume reduction can be maintained. Additionally. contaminants that are removed via filtration are also not impacted by cold climates. In contrary, dissolved contaminants, nutrients, and organics are significantly more variable in their ability to be removed or degraded via bioretention in colder temperatures. Winter road maintenance salts have been shown to negatively impact the removal of some contaminants and positively impact others, while their effects on properly selected vegetation or bacteria health are also not well understood. Research in these water quality aspects has been inconsistent and therefore requires further study.展开更多
INTRODUCTION In cold climates,a large amount of heat is lost through windows during the winter.For instance,a double-pane window might allow as much as 10 times the amount of heat to leave a house compared to the same...INTRODUCTION In cold climates,a large amount of heat is lost through windows during the winter.For instance,a double-pane window might allow as much as 10 times the amount of heat to leave a house compared to the same area of a typical 2×6 wall.It makes sense to upgrade or insulate windows in order to improve the thermal envelope of a home,especially in an area with a long heating season;however,windows are a very expensive component of the building envelope to replace.Replacing a single window can cost several hundred to more than a thousand dollars;therefore,people often resort to cheaper methods to reduce heat loss,such as shutters or curtains.Others may already have high-performance windows,but want to reduce heat loss even further by placing movable insulation over their windows during the cold winter nights.To help guide these decisions,the Cold Climate Housing Research Center(CCHRC)in Fairbanks,Alaska,conducted a study of common window insulation methods and compared them in terms of thermal effectiveness,affordability,ease of installation,durability,functionality,and condensation resistance.The purpose of the study was to inform homeowners about the various advantages and disadvantages of different window treatments.As part of the research,CCHRC studied a variety of methods and windows in volunteers’homes to understand how the methods work in real-life situations.CCHRC also modeled the retrofit window treatments with Therm 6.3,a modeling program,to help explain more generally how they can help homeowners.展开更多
The authors investigate the dominant mode of climatological intraseasonal oscillation(CISO) of surface air temperature(SAT) and rainfall in China, and discuss the linkage of cold and wet climate in South China(SC) wit...The authors investigate the dominant mode of climatological intraseasonal oscillation(CISO) of surface air temperature(SAT) and rainfall in China, and discuss the linkage of cold and wet climate in South China(SC) with the Arctic circulation regime during the cold season(from November to March). Results show that a positive CISO displays a cold-dry climate in North China,whereas a cold-wet pattern prevails in SC with a quasi-30-day oscillation during the peak winter season. In SC, the intraseasonal variability of SAT plays a leading role, altering the cold-wet climate by the southward shift of a cold front. Evidence shows that the circulation regime related to the cold and wet climate in SC is mainly regulated by a pair of propagating ISO modes at the500-hPa geopotential height in the negative phase of Arctic Oscillation. It is demonstrated that the local cyclonic wave activity enhances the southward movement of the Siberian high, favoring an unstable atmosphere and resulting in the cold-wet climate over SC. Therefore, the cold-air activity acts as a precursor for subseasonal rainfall forecasting in SC.展开更多
Cold regions are a special combat environment in which low temperatures have a great impact on human metabolism and other vital functions, including the nervous, motion, cardiovascular, circulatory, respiratory, and u...Cold regions are a special combat environment in which low temperatures have a great impact on human metabolism and other vital functions, including the nervous, motion, cardiovascular, circulatory, respiratory, and urinary systems; consequently, low temperatures often aggravate existing trauma, leading to high mortality rates if rapid and appropriate treatment is not provided. Hypothermia is an independent risk factor of fatality following combat trauma; therefore, proactive preventative measures are needed to reduce the rate of mortality. After summarizing the basic research on battlefield environments and progress in the prevention and treatment of trauma, this article concludes that current treatment and prevention measures for combat trauma in cold regions are inadequate. Future molecular biology studies are needed to elucidate the mechanisms and relevant cell factors underlying bodily injury caused by cold environment, a research goal will also allow further exploration of corresponding treatments.展开更多
The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change...The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change is really a sensitive integral variation value of many variations, or a combined function of coupling effects of various big systems. Therefore the above mentioned superposed action of different systems and the coupling effect of sun earth and biological aspects may be called as sun earth biological coupling effect system. Based on this hypothesis, the corresponding sun dynamic, air dynamic, water dynamic and earth dynamic conceptional models are established in order to research the multiple coupling effects and feedback machsnism between these big systems. In order to determine the relations, effectness and coherent relation of different variations, the quantity, analysis is conducted through collective variation and stage division. The quantity analysis indicates that the earths spindle rotation speed is the dynamic mechanism controlling the sea level change of fluctuation. The change rate of sea level in the world is ＋1.32 ＋ 0.22 mm/a, while the sea level change rate in China is only＋1.39 ＋ 0.26 mm/a in average. If take the CO2 content as the climate marker, eight cold stages （periods） are grouped out since two hundreds years AC. The extreme cold of the eighth cold stage started approximately at 1850 years AC. and if the stage from the extreme cold to extreme warm is determined as long as 200 years, the present ongoing warm stage will end at about 2050 years, there after the temperature will begin to tower. If the stage between cold and warm extremes lasts for 250 years, then the temperature will become lower at about 2100 year. Until to that time, the sea-level is estimated to raise ＋7 - ＋11 ＋ 3.5 cm again, and there after, the sea level will begin the new lowering trend. In the same time, the climate will enter into next new cold stage subsequently.展开更多
The Northern Hemisphere(NH)often experiences frequent cold air outbreaks and heavy snowfalls during La Nina winters.In 2022,a third-year La Nina event has exceeded both the oceanic and atmospheric thresholds since spr...The Northern Hemisphere(NH)often experiences frequent cold air outbreaks and heavy snowfalls during La Nina winters.In 2022,a third-year La Nina event has exceeded both the oceanic and atmospheric thresholds since spring and is predicted to reach its mature phase in December 2022.Under such a significant global climate signal,whether the Eurasian Continent will experience a tough cold winter should not be assumed,despite the direct influence of mid-to high-latitude,large-scale atmospheric circulations upon frequent Eurasian cold extremes,whose teleconnection physically operates by favoring Arctic air invasions into Eurasia as a consequence of the reduction of the meridional background temperature gradient in the NH.In the 2022/23 winter,as indicated by the seasonal predictions from various climate models and statistical approaches developed at the Institute of Atmospheric Physics,abnormal warming will very likely cover most parts of Europe under the control of the North Atlantic Oscillation and the anomalous anticyclone near the Ural Mountains,despite the cooling effects of La Nina.At the same time,the possibility of frequent cold conditions in mid-latitude Asia is also recognized for this upcoming winter,in accordance with the tendency for cold air invasions to be triggered by the synergistic effect of a warm Arctic and a cold tropical Pacific on the hemispheric scale.However,how the future climate will evolve in the 2022/23 winter is still subject to some uncertainty,mostly in terms of unpredictable internal atmospheric variability.Consequently,the status of the mid-to high-latitude atmospheric circulation should be timely updated by medium-term numerical weather forecasts and sub-seasonal-to-seasonal prediction for the necessary date information and early warnings.展开更多
Ischemic stroke is the leading cause of death in the Chinese population.The incidence of cerebral infarction is higher in high-altitude regions,particularly those above 3,500 m,than in populations residing at lower al...Ischemic stroke is the leading cause of death in the Chinese population.The incidence of cerebral infarction is higher in high-altitude regions,particularly those above 3,500 m,than in populations residing at lower altitudes[1].There are various speculations regarding the mechanisms behind this phenomenon,one of which is that the low oxygen content and cold climate at high altitudes may increase the occurrence of vascular diseases[2].The multifactorial effect of high-altitude environments on residential populations makes it challenging for researchers to determine the specific pathways through which these diseases occur.展开更多
Selecting a sustainable heat energy supply system for high-altitude,cold climatic communities in developing countries is essential for both decision-makers and the scientific community.However,no comprehensive guide o...Selecting a sustainable heat energy supply system for high-altitude,cold climatic communities in developing countries is essential for both decision-makers and the scientific community.However,no comprehensive guide or framework exists to address this issue and decarbonize cold communities sustainably.This research aims to fill that gap by identifying and developing a methodology for selecting a suitable heat energy supply system,using Kyrgyzstan as a case study.The approach takes into account renewable energy sources,local conditions,and specific criteria necessary for designing a sustainable energy supply.The paper introduces a decision-making framework based on 17 criteria,covering geographical,environmental,economic,technical,and social aspects,derived from the opinions of over 20 experts.This framework serves as a guide for selecting and designing an appropriate heat energy supply system.Five heat supply options are analysed in Kyrgyzstan’s high-altitude,cold rural setting to demonstrate the framework’s potential.The analysis reveals that centralized district heating is the most suitable solution,scoring 79%for system selection.This methodology is partially or fully transferable to regions or countries with similar climates and local circumstances,offering a valuable resource for the development of sustainable heat energy solutions in cold,high-altitude communities.展开更多
The aim of the research was to evaluate, at site scale, the influence of freezing and freeze/thaw cycles on the survival of faecal coliforms and faecal enterococci in soil, in a climate change perspective. Before the ...The aim of the research was to evaluate, at site scale, the influence of freezing and freeze/thaw cycles on the survival of faecal coliforms and faecal enterococci in soil, in a climate change perspective. Before the winter period and during grazing, viable cells of faecal coliforms and faecal enterococci were detected only in the first 10 cm below ground, while,after the winter period and before the new seasonal grazing, a lower number of viable cells of both faecal indicators was detected only in some of the investigated soil profiles, and within the first 5 cm. Taking into consideration the results of specific investigations, we hypothesise that the non-uniform spatial distribution of grass roots within the studied soil can play an important role in influencing this phenomenon, while several abiotic factors do not play any significant role. Taking into account the local trend in the increase of air temperature, a different distribution of microbial pollution over time is expected in spring waters, in future climate scenarios. The progressive increase in air temperature will cause a progressive decrease in freeze/thaw cycles at higher altitudes, minimising cold shocks on microbial cells, and causing spring water pollution also during winter.展开更多
China’s winter sports boom is expanding beyond its traditional northern heartlands,fueling a dynamic ice-snow economy and culture nationwide.This seasonal surge is driven by sustained investment and innovative develo...China’s winter sports boom is expanding beyond its traditional northern heartlands,fueling a dynamic ice-snow economy and culture nationwide.This seasonal surge is driven by sustained investment and innovative development models that are turning cold climates into hot economic opportunities.展开更多
Passive House buildings with an annual energy demand of less than 15 kWh/m^(2)a(i.e.kWh/m^(2) per annum)can help Canada and other countries achieve thermal comfort with minimum energy use and carbon footprint through ...Passive House buildings with an annual energy demand of less than 15 kWh/m^(2)a(i.e.kWh/m^(2) per annum)can help Canada and other countries achieve thermal comfort with minimum energy use and carbon footprint through meticulous design and selection of highly efficient building envelope elements and appliances.Shipping con-tainer based passive houses can reduce the cost of passive house construction and also promote recycling.In this paper,a passive house built using shipping containers,orig-inally designed for Victoria,BC,Canada,is analyzed using Passive House Planning Package(PHPP)software in different climactic zones of Canada.The locations under consideration are:Halifax(Cool-Temperate),Toronto(Cold-Temperate),Edmonton(Cold),and Yellowknife(Arctic-Climate).This paper critically examines the energy demand changes in various climate zones and make necessary modifications to the design to achieve passive house energy performance requirements in selected climates.Results show that with modified designs shipping container passive houses can meet passive house requirements,except in the Arctic-Climate of Yellowknife.展开更多
The Tibetan Plateau,the highest and largest plateau on Earth,is characterized by low oxygen pressure,limited primary productivity,a cold climate,and high ecological fragility[1].Conventional wisdom has long suggested ...The Tibetan Plateau,the highest and largest plateau on Earth,is characterized by low oxygen pressure,limited primary productivity,a cold climate,and high ecological fragility[1].Conventional wisdom has long suggested that human settlement in this highaltitude region occurred relatively late in the global expansion of modern humans,likely during the terminal Pleistocene or Early to Middle Holocene[2].However,recent studies have pushed back the first human occupation of the Tibetan Plateau to the early part of Late Pleistocene or even the later Middle Pleistocene.These studies have also suggested that archaic hominins—specifically Denisovans—rather than modern humans,were the first pioneers of the plateau[3,4].展开更多
Road tunnels consume a large amount of energy,especially in the Canadian cold climate,where the roads are heated electrically or deicing during the winter.For a more sustainable and resilient road tunnel energy system...Road tunnels consume a large amount of energy,especially in the Canadian cold climate,where the roads are heated electrically or deicing during the winter.For a more sustainable and resilient road tunnel energy system,we conducted an exploratory study on installing a semi-transparent photovoltaic(STPV)canopy at the entrances and exits of a tunnel under a river.The proposed system generates solar-powered electricity,improves thermal and visual conditions,and reduces energy loads.In this study,field measurements of road surface temperature and air temperature were conducted,and numerical simulations with and without STPV were performed to study air and road surface temperatures under different traffic speeds.The field measurements show the road surface temperatures are higher than the air temperature on average.The interior air and road surface temperature were measured to be above 0°C,even though the outdoor temperature is far below 0°C,thus significantly reducing the need for deicing in winter using salts.The simulations show that the air and surface temperatures elevate due to the solar transmission heat through the STPV canopy,thus reducing deicing energy consumption significantly.The fire safety analysis also showed that the proposed system's top opening should be located near the tunnel entrance instead of the canopy entrance for better smoke exhaust during a fire.展开更多
There is a lack of facade design methods for early design stages to balance thermal comfort and daylight provision that consider the obstruction angle as an independent variable without using modeling and simulations....There is a lack of facade design methods for early design stages to balance thermal comfort and daylight provision that consider the obstruction angle as an independent variable without using modeling and simulations.This paper aims to develop easy-to use solar radiationbased prediction method for the design of office building facades(i.e.,design parameters:room size,window-to-floor ratio,and glazing thermal/optical properties)located in urban canyons to balance daylight provision according to the European standard EN 17037:2018 and thermal comfort through specific cooling capacity.We used a simulation-based methodology that includes correlation analyses between building performance metrics and design parameters,the development of design workflows,accuracy analysis,and validation through the application of the workflows to a new development office building facades located in Tallinn,Estonia.The validation showed that the mean percentage of right/conservative predictions of thermal comfort classes is 98.8%whereas for daylight provision,it is higher than 75.6%.The use of the proposed prediction method can help designers to work more efficiently during early design stages and to obtain optimal performative solutions in much shorter time:window sizing in 73,152 room combinations in 80 s.展开更多
Accurate short-term forecasting of heating energy demand is needed for achieving optimal building energy management,cost savings,environmental sustainability,and responsible energy consumption.Furthermore,short-term h...Accurate short-term forecasting of heating energy demand is needed for achieving optimal building energy management,cost savings,environmental sustainability,and responsible energy consumption.Furthermore,short-term heating energy prediction contributes to zero-energy building performance in cold climates.Given the critical importance of short-term forecasting in heating energy management,this study evaluated six prevalent deep-learning algorithms to predict energy load,including single and hybrid models.The overall best-performing predictors were hybrid models using Convolutional Neural Networks,regardless of whether they were multivariate or univariate.Nevertheless,while the multivariate models performed better in the first hour,the univariate models often were more accurate in the final 24 h.Thus,the best-performing predictor of the first timestep was a multivariate hybrid Convolutional Neural Network–Recurrent Neural Network model with a coefficient of determination(R^(2))of 0.98 and the lowest mean absolute error.Yet,the best-performing predictor of the final timestep was the univariate hybrid model Convolutional Neural Network–Long Short-Term Memory with an R^(2)of 0.80.Also,the prediction accuracy of the best-performing multivariate hybrid models reduced faster per hour compared to the univariate models.These findings suggest that multivariate models may be better suited for early timestep predictions,while univariate models may be better suited for later time steps.Hence,combining the models can enhance accuracy at various timesteps for achieving high fidelity in forecasting and offering a comprehensive tool for energy management.展开更多
文摘Heat Recovery Ventilators(HRVs)are essential for improving indoor air quality(IAQ)and reducing energy consumption in residential buildings situated in cold climates.This study considers the efficiency and performance optimization of HRVs under cold climatic conditions,where conventional ventilation systems increase heat loss.A comprehensive numerical model was developed using COMSOL Multiphysics,integrating fluid dynamics,heat transfer,and solid mechanics to evaluate the thermal efficiency and structural integrity of an HRV system.The methodology employed a detailed geometry with tetrahedral elements,temperature-dependent material properties,and coupled governing equations solved under Tehran-specific boundary conditions.A multi-objective optimization was implemented in the framework of the Nelder-Mead simplex algorithm,targeting the maximization of the average outlet temperature and minimization of the maximum von Mises thermal stress,with inlet flow velocity as the design variable(range:0.5–1.2m/s).Results indicate an optimal velocity of 0.51563 m/s,achieving an average outlet temperature of 289.44 K and maximum von Mises stress of 221 MPa,validated through mesh independence and detailed contour analyses of temperature,velocity,and stress distributions.
文摘Constructed wetlands（CWs） have been successfully used for treating various wastewaters for decades and have been identified as a sustainable wastewater management option worldwide.However,the application of CW for wastewater treatment in frigid climate presents special challenges.Wetland treatment of wastewater relies largely on biological processes,and reliable treatment is often a function of climate conditions.To date,the rate of adoption of wetland technology for wastewater treatment in cold regions has been slow and there are relatively few published reports on CW applications in cold climate.This paper therefore highlights the practice and applications of treatment wetlands in cold climate.A comprehensive review of the effectiveness of contaminant removal in different wetland systems including：（1） free water surface（FWS） CWs;（2） subsurface flow（SSF） CWs;and（3） hybrid wetland systems,is presented.The emphasis of this review is also placed on the influence of cold weather conditions on the removal efficacies of different contaminants.The strategies of wetland design and operation for performance intensification,such as the presence of plant,operational mode,effluent recirculation,artificial aeration and in-series design,which are crucial to achieve the sustainable treatment performance in cold climate,are also discussed.This study is conducive to further research for the understanding of CW design and treatment performance in cold climate.
文摘In the process of mining coal resources, the mining site needs crushing, transportation and hydraulic equipment. Efficient use of mechanical equipment can ensure the stability and safety of the whole mining work to the greatest extent. The crushing, transportation and hydraulic equipment have high requirements on the welding process, and the whole welding process is complicated. The quality of welding directly affects the safety and service life of equipment.
文摘The global shift towards sustainable and environmentally friendly transportation options has led to the increasing adoption of electric buses(Ebuses).To optimize the deployment and operational strategies of Ebuses,it is imperative to accurately predict their energy consumption under varying conditions,particularly in cold climates where battery life is typically degraded.The exploration of this aspect within the Canadian context has been limited.In addition,we have found that existing models in the literature perform poorly in the Canadian environment,giving rise to the need for new models using Canadian data.This paper focuses on the development,comparison,and evaluation of various data-driven models designed to predict the energy consumption of different Ebuses with different heating technologies under a wide range of climate conditions.We specifically use Canadian data as a good representative of cold climates in general.The results show that the performance of the different bus types varies substantially under the exact same conditions.In addition,tree-based family of models proves to be the most suitable approach for predicting the Ebus consumption rate.The results indicate that the Random Forest method emerges as the superior choice for predicting the energy consumption rate,with a resulting mean absolute error of 0.09–0.1 kWh/km observed across the different models.Furthermore,SHAP analysis shows that the main variables influencing the energy consumption rate depend on the type of heating system(using the battery for heating or using an auxiliary system that utilizes diesel for heating)adopted.
基金funded by National Natural Science Foundation of China Youth Project(No.52308018)China Higher Education Institution Industry-University-Research Innovation Fund(2024SE031)+1 种基金Doctoral Postdoctoral Funding Project in Heilongjiang Province(No.LBH-Z22159)Fundamental Research Funds for Central Universities(HIT.HSS.202312)。
文摘The school commuting path is an important space for elementary school students to engage with society and nature.The design of these paths reflects concerns for children's rights and healthy development and has crucial impacts on creating supportive environments for children.The scientific evaluation of the child-friendly level of school commuting paths forms a significant basis for shaping child-friendly environments and promoting the comprehensive development of children.Additionally,due to the unique climatic conditions,cold climate cities excert a distinct impact on children's behavior,activities,and physical and mental health compared to cities in other climate zones.This study,from the perspective of child-friendliness,constructs an evaluation system for school commuting paths in cold climate cities,based on children's behavioral characteristics and environmental needs.The system includes dimensions such as safety,diversity,and comfort.With children and their caregivers as the evaluators,the study applies structural equation modeling to assign weights to the various dimension indicators in the evaluation system.The research focuses on five elementary schools in the Nangang District of Harbin City,using methods such as machine learning,space syntax,and field surveys to assess the school commuting paths.Building upon these findings,the study constructs the characteristic profile of the commuting paths and proposes evidence-based control and optimization strategies for different types of school commuting paths in cold climate cities from a child-friendly perspective.
文摘Bioretention is a popular best management practice of low impact development that el/ecUvely restores urban hydrologic characteristics to those ofpredevelopment and improves water quality prior to conveyance to surface waters. This is achieved by utilizing an engineered system containing a surface layer of mulch, a thick soil media often amended with a variety of materials to improve water oualitv, a variety of vegetation, and underdrains, depending on the surrounding soil characteristics.Bioretention systems have been studied quite extensively for warm climate applications, but ctata strongly supporting their long-tema efficacy and application in cold climates is sparse. Although it is apparent that biorelention is an effective stormwater management system, its design in cold climate needs further research. Existing cold climate research has shown that coarser media is required to prevent concrete frost from forming. For spring, summer and fall seasons, if sufficient permeability exists to drain the system prior to freezing, peak flow and volume reduction can be maintained. Additionally. contaminants that are removed via filtration are also not impacted by cold climates. In contrary, dissolved contaminants, nutrients, and organics are significantly more variable in their ability to be removed or degraded via bioretention in colder temperatures. Winter road maintenance salts have been shown to negatively impact the removal of some contaminants and positively impact others, while their effects on properly selected vegetation or bacteria health are also not well understood. Research in these water quality aspects has been inconsistent and therefore requires further study.
基金the Alaska Housing Finance Corporation,who provided the funding for this project.
文摘INTRODUCTION In cold climates,a large amount of heat is lost through windows during the winter.For instance,a double-pane window might allow as much as 10 times the amount of heat to leave a house compared to the same area of a typical 2×6 wall.It makes sense to upgrade or insulate windows in order to improve the thermal envelope of a home,especially in an area with a long heating season;however,windows are a very expensive component of the building envelope to replace.Replacing a single window can cost several hundred to more than a thousand dollars;therefore,people often resort to cheaper methods to reduce heat loss,such as shutters or curtains.Others may already have high-performance windows,but want to reduce heat loss even further by placing movable insulation over their windows during the cold winter nights.To help guide these decisions,the Cold Climate Housing Research Center(CCHRC)in Fairbanks,Alaska,conducted a study of common window insulation methods and compared them in terms of thermal effectiveness,affordability,ease of installation,durability,functionality,and condensation resistance.The purpose of the study was to inform homeowners about the various advantages and disadvantages of different window treatments.As part of the research,CCHRC studied a variety of methods and windows in volunteers’homes to understand how the methods work in real-life situations.CCHRC also modeled the retrofit window treatments with Therm 6.3,a modeling program,to help explain more generally how they can help homeowners.
基金jointly supported by the National Natural Science Foundation of China [grant numbers 41475057,41775052,and41505049]the Special Fund for Public Welfare Industry [grant number GYHY20140619]+1 种基金the Basic Scientific Research and Operation Foundation of CAMS [grant numbers 2018Z006 and2017R001]the Jiangsu Collaborative Innovation Center for Climate Change
文摘The authors investigate the dominant mode of climatological intraseasonal oscillation(CISO) of surface air temperature(SAT) and rainfall in China, and discuss the linkage of cold and wet climate in South China(SC) with the Arctic circulation regime during the cold season(from November to March). Results show that a positive CISO displays a cold-dry climate in North China,whereas a cold-wet pattern prevails in SC with a quasi-30-day oscillation during the peak winter season. In SC, the intraseasonal variability of SAT plays a leading role, altering the cold-wet climate by the southward shift of a cold front. Evidence shows that the circulation regime related to the cold and wet climate in SC is mainly regulated by a pair of propagating ISO modes at the500-hPa geopotential height in the negative phase of Arctic Oscillation. It is demonstrated that the local cyclonic wave activity enhances the southward movement of the Siberian high, favoring an unstable atmosphere and resulting in the cold-wet climate over SC. Therefore, the cold-air activity acts as a precursor for subseasonal rainfall forecasting in SC.
文摘Cold regions are a special combat environment in which low temperatures have a great impact on human metabolism and other vital functions, including the nervous, motion, cardiovascular, circulatory, respiratory, and urinary systems; consequently, low temperatures often aggravate existing trauma, leading to high mortality rates if rapid and appropriate treatment is not provided. Hypothermia is an independent risk factor of fatality following combat trauma; therefore, proactive preventative measures are needed to reduce the rate of mortality. After summarizing the basic research on battlefield environments and progress in the prevention and treatment of trauma, this article concludes that current treatment and prevention measures for combat trauma in cold regions are inadequate. Future molecular biology studies are needed to elucidate the mechanisms and relevant cell factors underlying bodily injury caused by cold environment, a research goal will also allow further exploration of corresponding treatments.
基金supported by the National Natural Foundation of China(40940025)National Science Foundation of Tianjin(07ZCGYSF02400,09JCYBJC07400)+2 种基金Program of China"973"(2007CB411807)Open Fund of the Key Lab of Global Change and Marine-Atmospheric Chemistry,SOA(GCMAC0806)National Natural ScienceFoundation(41006002)
文摘The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change is really a sensitive integral variation value of many variations, or a combined function of coupling effects of various big systems. Therefore the above mentioned superposed action of different systems and the coupling effect of sun earth and biological aspects may be called as sun earth biological coupling effect system. Based on this hypothesis, the corresponding sun dynamic, air dynamic, water dynamic and earth dynamic conceptional models are established in order to research the multiple coupling effects and feedback machsnism between these big systems. In order to determine the relations, effectness and coherent relation of different variations, the quantity, analysis is conducted through collective variation and stage division. The quantity analysis indicates that the earths spindle rotation speed is the dynamic mechanism controlling the sea level change of fluctuation. The change rate of sea level in the world is ＋1.32 ＋ 0.22 mm/a, while the sea level change rate in China is only＋1.39 ＋ 0.26 mm/a in average. If take the CO2 content as the climate marker, eight cold stages （periods） are grouped out since two hundreds years AC. The extreme cold of the eighth cold stage started approximately at 1850 years AC. and if the stage from the extreme cold to extreme warm is determined as long as 200 years, the present ongoing warm stage will end at about 2050 years, there after the temperature will begin to tower. If the stage between cold and warm extremes lasts for 250 years, then the temperature will become lower at about 2100 year. Until to that time, the sea-level is estimated to raise ＋7 - ＋11 ＋ 3.5 cm again, and there after, the sea level will begin the new lowering trend. In the same time, the climate will enter into next new cold stage subsequently.
基金supported by the Key Research Program of Frontier Sciences,CAS(Grant No.ZDBS-LY-DQC010)the National Natural Science Foundation of China(Grant No.42175045)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB42000000)。
文摘The Northern Hemisphere(NH)often experiences frequent cold air outbreaks and heavy snowfalls during La Nina winters.In 2022,a third-year La Nina event has exceeded both the oceanic and atmospheric thresholds since spring and is predicted to reach its mature phase in December 2022.Under such a significant global climate signal,whether the Eurasian Continent will experience a tough cold winter should not be assumed,despite the direct influence of mid-to high-latitude,large-scale atmospheric circulations upon frequent Eurasian cold extremes,whose teleconnection physically operates by favoring Arctic air invasions into Eurasia as a consequence of the reduction of the meridional background temperature gradient in the NH.In the 2022/23 winter,as indicated by the seasonal predictions from various climate models and statistical approaches developed at the Institute of Atmospheric Physics,abnormal warming will very likely cover most parts of Europe under the control of the North Atlantic Oscillation and the anomalous anticyclone near the Ural Mountains,despite the cooling effects of La Nina.At the same time,the possibility of frequent cold conditions in mid-latitude Asia is also recognized for this upcoming winter,in accordance with the tendency for cold air invasions to be triggered by the synergistic effect of a warm Arctic and a cold tropical Pacific on the hemispheric scale.However,how the future climate will evolve in the 2022/23 winter is still subject to some uncertainty,mostly in terms of unpredictable internal atmospheric variability.Consequently,the status of the mid-to high-latitude atmospheric circulation should be timely updated by medium-term numerical weather forecasts and sub-seasonal-to-seasonal prediction for the necessary date information and early warnings.
基金supported by the National Natural Science Foundation of Chongqing,China(CSTB2022NSCQ-MSX1100)National Natural Science Foundation of China(grant no.82101499).
文摘Ischemic stroke is the leading cause of death in the Chinese population.The incidence of cerebral infarction is higher in high-altitude regions,particularly those above 3,500 m,than in populations residing at lower altitudes[1].There are various speculations regarding the mechanisms behind this phenomenon,one of which is that the low oxygen content and cold climate at high altitudes may increase the occurrence of vascular diseases[2].The multifactorial effect of high-altitude environments on residential populations makes it challenging for researchers to determine the specific pathways through which these diseases occur.
基金funded by the Federal Ministry of Education and Research(BMBF)of the Federal Republic of Germany within the CLIENT II funding programme International Partnerships for Sustainable Innovations under the project“ÖkoFlussPlan.”。
文摘Selecting a sustainable heat energy supply system for high-altitude,cold climatic communities in developing countries is essential for both decision-makers and the scientific community.However,no comprehensive guide or framework exists to address this issue and decarbonize cold communities sustainably.This research aims to fill that gap by identifying and developing a methodology for selecting a suitable heat energy supply system,using Kyrgyzstan as a case study.The approach takes into account renewable energy sources,local conditions,and specific criteria necessary for designing a sustainable energy supply.The paper introduces a decision-making framework based on 17 criteria,covering geographical,environmental,economic,technical,and social aspects,derived from the opinions of over 20 experts.This framework serves as a guide for selecting and designing an appropriate heat energy supply system.Five heat supply options are analysed in Kyrgyzstan’s high-altitude,cold rural setting to demonstrate the framework’s potential.The analysis reveals that centralized district heating is the most suitable solution,scoring 79%for system selection.This methodology is partially or fully transferable to regions or countries with similar climates and local circumstances,offering a valuable resource for the development of sustainable heat energy solutions in cold,high-altitude communities.
基金supported by the European Union (CC-Water S project, SEE/A/022/2.1/X)by the Ministero dell'Istruzione, dell'Università e della Ricerca (PRIN2008TL25YL)
文摘The aim of the research was to evaluate, at site scale, the influence of freezing and freeze/thaw cycles on the survival of faecal coliforms and faecal enterococci in soil, in a climate change perspective. Before the winter period and during grazing, viable cells of faecal coliforms and faecal enterococci were detected only in the first 10 cm below ground, while,after the winter period and before the new seasonal grazing, a lower number of viable cells of both faecal indicators was detected only in some of the investigated soil profiles, and within the first 5 cm. Taking into consideration the results of specific investigations, we hypothesise that the non-uniform spatial distribution of grass roots within the studied soil can play an important role in influencing this phenomenon, while several abiotic factors do not play any significant role. Taking into account the local trend in the increase of air temperature, a different distribution of microbial pollution over time is expected in spring waters, in future climate scenarios. The progressive increase in air temperature will cause a progressive decrease in freeze/thaw cycles at higher altitudes, minimising cold shocks on microbial cells, and causing spring water pollution also during winter.
文摘China’s winter sports boom is expanding beyond its traditional northern heartlands,fueling a dynamic ice-snow economy and culture nationwide.This seasonal surge is driven by sustained investment and innovative development models that are turning cold climates into hot economic opportunities.
文摘Passive House buildings with an annual energy demand of less than 15 kWh/m^(2)a(i.e.kWh/m^(2) per annum)can help Canada and other countries achieve thermal comfort with minimum energy use and carbon footprint through meticulous design and selection of highly efficient building envelope elements and appliances.Shipping con-tainer based passive houses can reduce the cost of passive house construction and also promote recycling.In this paper,a passive house built using shipping containers,orig-inally designed for Victoria,BC,Canada,is analyzed using Passive House Planning Package(PHPP)software in different climactic zones of Canada.The locations under consideration are:Halifax(Cool-Temperate),Toronto(Cold-Temperate),Edmonton(Cold),and Yellowknife(Arctic-Climate).This paper critically examines the energy demand changes in various climate zones and make necessary modifications to the design to achieve passive house energy performance requirements in selected climates.Results show that with modified designs shipping container passive houses can meet passive house requirements,except in the Arctic-Climate of Yellowknife.
基金supported by the National Natural Science Foundation of China(42472036)。
文摘The Tibetan Plateau,the highest and largest plateau on Earth,is characterized by low oxygen pressure,limited primary productivity,a cold climate,and high ecological fragility[1].Conventional wisdom has long suggested that human settlement in this highaltitude region occurred relatively late in the global expansion of modern humans,likely during the terminal Pleistocene or Early to Middle Holocene[2].However,recent studies have pushed back the first human occupation of the Tibetan Plateau to the early part of Late Pleistocene or even the later Middle Pleistocene.These studies have also suggested that archaic hominins—specifically Denisovans—rather than modern humans,were the first pioneers of the plateau[3,4].
基金This research project was supported by the Ministry of Transport of Quebec and the NSERC Discovery Grants[#RGPIN-2018-06734]from Canada5s Natural Sciences and Engineering Research Council.
文摘Road tunnels consume a large amount of energy,especially in the Canadian cold climate,where the roads are heated electrically or deicing during the winter.For a more sustainable and resilient road tunnel energy system,we conducted an exploratory study on installing a semi-transparent photovoltaic(STPV)canopy at the entrances and exits of a tunnel under a river.The proposed system generates solar-powered electricity,improves thermal and visual conditions,and reduces energy loads.In this study,field measurements of road surface temperature and air temperature were conducted,and numerical simulations with and without STPV were performed to study air and road surface temperatures under different traffic speeds.The field measurements show the road surface temperatures are higher than the air temperature on average.The interior air and road surface temperature were measured to be above 0°C,even though the outdoor temperature is far below 0°C,thus significantly reducing the need for deicing in winter using salts.The simulations show that the air and surface temperatures elevate due to the solar transmission heat through the STPV canopy,thus reducing deicing energy consumption significantly.The fire safety analysis also showed that the proposed system's top opening should be located near the tunnel entrance instead of the canopy entrance for better smoke exhaust during a fire.
基金supported by the Estonian Centre of Excellence in Zero Energy and Resource Efficient Smart Buildings and Districts,ZEBE(Grant No.2014-2020.4.01.15-0016)the Estonian Ministry of Education and Research and European Regional Fund(Grant 2014-2020.4.01.20-0289)the European Regional Development Fund and the Estonian Research Council(Grant No.PSG409).
文摘There is a lack of facade design methods for early design stages to balance thermal comfort and daylight provision that consider the obstruction angle as an independent variable without using modeling and simulations.This paper aims to develop easy-to use solar radiationbased prediction method for the design of office building facades(i.e.,design parameters:room size,window-to-floor ratio,and glazing thermal/optical properties)located in urban canyons to balance daylight provision according to the European standard EN 17037:2018 and thermal comfort through specific cooling capacity.We used a simulation-based methodology that includes correlation analyses between building performance metrics and design parameters,the development of design workflows,accuracy analysis,and validation through the application of the workflows to a new development office building facades located in Tallinn,Estonia.The validation showed that the mean percentage of right/conservative predictions of thermal comfort classes is 98.8%whereas for daylight provision,it is higher than 75.6%.The use of the proposed prediction method can help designers to work more efficiently during early design stages and to obtain optimal performative solutions in much shorter time:window sizing in 73,152 room combinations in 80 s.
基金funded by the Natural Sciences and Engineering Research Council(NSERC)Discovery Grant,grant number RGPIN-05481.
文摘Accurate short-term forecasting of heating energy demand is needed for achieving optimal building energy management,cost savings,environmental sustainability,and responsible energy consumption.Furthermore,short-term heating energy prediction contributes to zero-energy building performance in cold climates.Given the critical importance of short-term forecasting in heating energy management,this study evaluated six prevalent deep-learning algorithms to predict energy load,including single and hybrid models.The overall best-performing predictors were hybrid models using Convolutional Neural Networks,regardless of whether they were multivariate or univariate.Nevertheless,while the multivariate models performed better in the first hour,the univariate models often were more accurate in the final 24 h.Thus,the best-performing predictor of the first timestep was a multivariate hybrid Convolutional Neural Network–Recurrent Neural Network model with a coefficient of determination(R^(2))of 0.98 and the lowest mean absolute error.Yet,the best-performing predictor of the final timestep was the univariate hybrid model Convolutional Neural Network–Long Short-Term Memory with an R^(2)of 0.80.Also,the prediction accuracy of the best-performing multivariate hybrid models reduced faster per hour compared to the univariate models.These findings suggest that multivariate models may be better suited for early timestep predictions,while univariate models may be better suited for later time steps.Hence,combining the models can enhance accuracy at various timesteps for achieving high fidelity in forecasting and offering a comprehensive tool for energy management.
