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River ice is a common occurrence in cold climate hydrological systems. The annual cycle of river ice formation, growth, decay and clearance can include low flows and ice jams, as well as mid-winter and spring break-up events. Reports and associated data on river ice occurrence are often limited to site and season-specific studies. Within Canada, the National Hydrometric Program (NHP) operates a network of gauging stations with water level as the primary measured variable to derive discharge. In the late 1990s, the Water Science and Technology Directorate of Environment and Climate Change Canada initiated a long-term effort to compile, archive and extract river ice related information from NHP hydrometric records. This data article describes the original research data set produced by this near 20-year effort: the Canadian River Ice Database (CRID). The CRID holds almost 73,000 variables from a network of 196 NHP stations throughout Canada that were in operation within the period 1894 to 2015. Over 100,000 paper and digital files were reviewed representing 10,378 station-years of active operation. The task of compiling this database involved manual extraction and input of more than 460,000 data entries on water level, discharge, date, time and data quality rating. Guidelines on the data extraction, rating procedure and challenges are provided. At each location, a time series of up to 15 variables specific to the occurrence of freeze-up and winter-low events, mid-winter break-up, ice thickness, spring break-up and maximum open-water level were compiled. This database follows up on several earlier efforts to compile information on river ice, which are summarized herein, and expands the scope and detail for use in Canadian river ice research and applications. Following the Government of Canada Open Data initiative, this original river ice data set is available at: https://doi.org/10.18164/c21e1852-ba8e-44af-bc13-48eeedfcf2f4 (de Rham et al., 2020). [ABSTRACT FROM AUTHOR]

Cold weather conditions pose significant challenges to the performance and durability of concrete materials, construction processes, and structures. This paper aims to provide a comprehensive overview of the material-related challenges in cold weather concrete construction, including slow setting, reduced curing rate, and slower strength development, as well as frost damage, early freezing, and freeze–thaw actions. Various innovative materials and technologies may be implemented to address these challenges, such as optimizing the concrete mix proportions, chemical admixtures, supplementary cementitious materials, and advanced construction techniques. The paper also examines the impact of weather-related challenges for personnel, equipment, and machinery in cold environments and highlights the importance of effective planning, communication, and management strategies. Results indicate that the successful implementation of appropriate strategies can mitigate the challenges, reduce construction time, and enhance the performance, durability, and sustainability of concrete structures in cold and freezing temperatures. The paper emphasizes the importance of staying updated about the latest advancements and best practices in the field. Future trends include the development of smart and functional concrete materials, advanced manufacturing and construction techniques, integrated design, and optimization of tools, all with a strong focus on sustainability and resilience. [ABSTRACT FROM AUTHOR]

The operation of electric vehicles in cold weather is a concern, but there is not a lot of literature available regarding the precise nature of impacts on travel range. Two types of commercial battery electric vehicles, namely, the Nissan Leaf and the Mitsubishi i-MiEV, were driven to depletion across a broad range of temperatures that occur naturally in Winnipeg, MB, Canada, due to its climate. Analysis of data showed that the travel range can be reasonably interpreted as a function of ambient temperature using a series of simple linear segments: an upper plateau above about +20 °C, a lower plateau below about −15 °C, and a linearly varying segment in the middle. Both the Leaf and i-MiEV appeared to follow this model, with a good correlation of data for the middle (linearly varying) segment. Impacts of air conditioning on the travel range were also separately tested. This paper provides guidance for more rigorous assessments of electric-vehicle range performance into the future. [ABSTRACT FROM PUBLISHER]

Purpose This paper aims to investigate the flow characteristics of lubricating grease in extremely cold weather in which it is difficult to convey the grease due to a huge pressure drop.Design/methodology/approach The rheological behavior of grease at various temperatures is studied by a rotary rheometer to determine the constitutive equation of lubricating grease. Based on the Herschel–Bulkley (H–B) model, the flow pattern of grease is then simulated by computational fluid dynamics and compared with the test results.Findings The yield stress increased dramatically when the shear rate was less than 1s−1 in the rheological experiments of continuous shear mode, and the phenomenon was more significant with the decrease in temperature. The rheological data obtained from the continuous shear mode agrees with the H–B equation after the shear thinned. In extremely cold conditions, there is a large yield stress in the lubricating grease; the numerical results show that the viscosity of lubricating grease increased with an increase in temperature, and the viscosity and velocity of lubricating grease showed uneven distribution leading to difficulty of lubricating grease delivery.Originality/value This paper focuses on the flow characteristics of lubricating grease in extremely cold area conditions which is studied rarely. In addition, the continuous shear model and oscillatory model are combined to establish the constitutive equations. Experiment and numerical simulation method are all used by establishing the H–B models. [ABSTRACT FROM AUTHOR]

The Antarctic plateau, characterized by cold and dry weather conditions with very little precipitation, is mostly covered by snow at the surface. This paper describes an intercomparison of snow models, of varying complexity, used for numerical weather prediction or academic research. The results of offline numerical simulations, carried out during 15 d in 2009, on a single site on the Antarctic plateau, show that the simplest models are able to reproduce the surface temperature as well as the most complex models provided that their surface parameters are well chosen. Furthermore, it is shown that the diversity of the surface parameters of the models strongly impacts the numerical simulations, in particular the temporal variability of the surface temperature and the components of the surface energy balance. The models tend to overestimate the surface temperature by 2–5 K at night and underestimate it by 2 K during the day. The observed and simulated turbulent latent heat fluxes are small, of the order of a few W m -2 , with a tendency to underestimate, while the sensible heat fluxes are in general too intense at night as well as during the day. The surface temperature errors are consistent with too large a magnitude of sensible heat fluxes during the day and night. Finally, it is shown that the most complex multilayer models are able to reproduce well the propagation of the daily diurnal wave, and that the snow temperature profiles in the snowpack are very close to the measurements carried out on site. [ABSTRACT FROM AUTHOR]

Black Sea freezing in winter is observed regularly in its northern parts and near the Kerch Strait. The reason for this is the relatively shallow northwestern shelf part and the river inflow of the three major European rivers Danube, Dnieper, and Dniester, as well as Don through the Azov Sea, carrying a large amount of fresh water to this part of the Black Sea. The global warming that has been observed in recent decades has made these episodes less intense; nevertheless, they exist and impact people who live n the area. The aim of this study is to analyze the extent of sea-ice variability in the last 15 years, observed by satellite observations, and to describe the weather conditions favorable for freezing to occur. It is found that, in 2006, 2012 and 2017, sea ice extended unusually southward, which is related to the unusually cold winter and weather conditions in these years. The weather patterns associated with the periods of maximal sea ice in the Black Sea are discussed. In addition, we analyze how the winter conditions change in the period 1926–2021 by combining different data sources. The winter is classified as cold, moderate or mild through the Winter Severity Index following a previously published methodology. The findings in our paper could help to monitor and predict these events and to inform the interested end-users. [ABSTRACT FROM AUTHOR]

This paper addresses dynamic positioning of surface vessels moored to the seabed via a spread mooring system, referred to as position mooring. In normal weather conditions, the mooring system constrains the vessel and the controller applies thruster force for motion damping and heading control, only. When environmental loads due to wind, waves, and current increase, thruster assistance is required also for positioning in order to avoid damage to the mooring lines. While traditional position mooring systems apply thruster force based on constraining the vessel to lie within a predefined geographical region, the controller designed in this paper instead employs structural reliability measures for the mooring lines to restrict movement. These structural reliability measures become an intrinsic part of the controller, enabling it to automatically adjust the admissible region for the vessel in the presence of changing winds, currents, and waves. [ABSTRACT FROM AUTHOR]

It is mandatory in South Africa that water for firefighting is included in the demand estimates input when designing municipal water networks. To this end, guidelines for determining fire flows for different risk categories have been developed. The most commonly used guidelines are the South African National Standard (SANS) 10090 of 2018 and the Department of Human Settlements (DHS) guide of 2019 (also called the Red Book). The evolution of the built environment, firefighting technologies and approaches, and the availability of freshwater resources all require that the fire flows in the guidelines are current and adequately protect communities from the devastating impacts of fires – this while conserving depleting freshwater resources and contributing to optimal water network design. Currently, empirical research into the appropriateness of the fire flows in SANS 10090 and the Red Book to firefighting efforts in South African municipalities is limited. This paper therefore compares water for firefighting in these two guidelines with some international companions and local firefighting data, and also compares similar data from the six studies published on this topic in South Africa. Some highlights from this investigation include: (i) the fire risk categories and fire flows in SANS 10090 and the Red Book are misaligned, and are contradictory in at least one instance; (ii) when compared with firefighting data, the fire flows in SANS 10090 and the Red Book are conservative; (iii) a significant percentage of fires were extinguished between 30 and 120 minutes; (iv) 10 kℓ or less of water was employed to extinguish more than 87% of fires; and (v) the frequencies of fires were positively related to dry and/or cold weather conditions. [ABSTRACT FROM AUTHOR]

The precast industry, due to its specific early-age strength requirements for hollowcore (HC) slab products, has been reluctant to introduce alternative cementitious materials such as ground granulated blast-furnace slag (GGBS) due to the slower strength development of such materials. This paper reports on a study undertaken at a precast production facility to examine how to overcome the consequences of strength loss due to the replacement of up to 50% of CEM I (42·5R), as usually used in cold weather conditions, with GGBS, for environmental or durability reasons. The GGBS concrete slabs were activated using thermal, chemical and mechanical means to enhance their early-age strength gain. The results were compared at early ages in terms of the temperature profile during curing, cube compressive strengths, load-carrying capacities for transportability requirements, ultimate load and short-term creep. In addition, 28 d densities and strengths were compared for in situ cubes and cores extracted from HC slab samples. The experimental results showed a favourable potential for replacing CEM I (42·5R) cement with up to 50% GGBS in winter without compromising on factory productivity. [ABSTRACT FROM AUTHOR]

Copyright of Hungarian Law Enforcement / Magyar Rendészet is the property of National University of Public Service and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reducing greenhouse gas emissions by providing non-fossil fuel energy sources is imminently necessary. The area of particular interest in this paper is the agricultural greenhouse industry. In these structures, significant heating demands are present, especially in cold climates, and are typically met by combusting fossil fuels. In an effort towards a sustainable energy supply, the potential of closed greenhouse systems in a cold climate is explored. In these systems, natural ventilation for cooling and dehumidification is replaced with active systems, and the thermal energy removed can be re-used, reducing the overall heating demand. A transient greenhouse model is created using TRNSYS software and validated with natural gas usage data from a reference greenhouse. The annual heating and cooling demands, effect of varying cover materials and potential for heat recovery ventilation are explored for the most concentrated greenhouse areas in Canada. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Cold regions with subzero temperatures (−20°C to −45°C) have important impacts on the mechanical properties of structural steel used in lattice steel towers of overhead transmission line systems. The results from regular material tests are not appropriate for the accurate analysis of joint strength in cold weather conditions. This paper presents the tensile test results of 18 coupons of steel material and eight groups (18 specimens per group) of bolted joints with Q345 and Q420 steel under temperatures of 20°C, −20°C, and −45°C. The results show that the yield‐to‐ultimate strength ratio of the joints under low temperature conditions is beyond the range of 0.60 to 0.75 for Q420 structural steel. Suggestions are made on how to improve the accuracy of joint design for both the partial resistance factor and the design value of joint yield strength in cold regions. [ABSTRACT FROM AUTHOR]

Identifying critical source areas (CSAs) of a watershed by phosphorus (P) loss assessment tools is essential for optimal placement of beneficial management practices (BMPs) to address diffuse P pollution. However, lack of significant progress in tackling diffuse P pollution could be, in part, associated with inefficacy of P loss assessment tools for accurately identifying CSAs. Phosphorus loss assessment tools have been developed to simulate P loss from the landscape where runoff is mainly driven by rainfall events. Therefore, they may underperform in cold climates where the land is often frozen during winter and runoff is dominated by snowmelt. This paper (i) reviews the strengths and weaknesses of current P loss assessment tools and their underlying assumptions in simulating soil P dynamics and P transfer to runoff, and (ii) highlights a number of challenges associated with modeling P transfer from agricultural land to surface waters in cold climates. Current P loss assessment tools do not appear to fully represent hydrological and biogeochemical processes responsible for P loss from CSAs, particularly in cold climates. Effort should be made to develop P loss assessment tools that are capable of considering P dynamics through the landscape as a result of abiotic perturbations that are common in cold climates, predicting runoff and P movement over frozen/partially frozen soils, and considering material-P connectivity between landscape and surface waters. Evaluating P loss assessment tools with water quality data is necessary to ensure such modifications result in improved identification of CSAs. [ABSTRACT FROM AUTHOR]

The original version of this paper was unfortunately published with an error in Fig. 3. The published figure includes excess layers, which negatively affects the readability of the figure. The correct figure is displayed below. The authors apologize for this error. [ABSTRACT FROM AUTHOR]

Based on the analysis of Asian temperature, the Asian Warming Hole (AWH) index is proposed in this paper to measure the intensity during the cold events process under the background of global warming in the early 21st century winter. The results show that the Asian continent is indeed experiencing a cold stage in the early 21st century winter, but it is just in a cold phase and will become warmer in the future. The relationship of AWH with atmospheric circulation is statistically close. Moreover, the sea surface temperature (SST) lead of 6 months, shows a higher correlation coefficient with AHW index. The SST anomalies over mid-latitude and high latitude Pacific regions may play an important role in Asian cold events in winter, but it is not stable as a precursor factor. The mechanism of this phenomenon is very complex, the atmosphere can reflect some characteristics, while ENSO cycle signal is more and more significant in recent years. [ABSTRACT FROM AUTHOR]

In this paper, a direct-expansion heat pump water heater system integrated uninsulated micro-channel PV/T solar collector (UMC-PVT-SC) is proposed. This system can realize storage for both thermal energy and electricity, ensuring the supply of domestic hot water. The theoretical models of micro-channel PV/T solar collector, hot water storage tank, compressor and electronic expansion valve are established to investigate the performance of the micro-channel PV/T heat pump water heater system. R134a is used as refrigerant. The system performance is numerically simulated using MATLAB for different solar radiation intensity, ambient temperature and wind speed. The results show that solar radiation intensity has the largest influence on the system performance, followed by ambient temperature and wind speed. The coefficient of performance of the heat pump (COP HP) and the overall coefficient of performance (COP pvt) of the integrated system increase while the required operating time reduces, as solar radiation intensity and ambient temperature increase. The uninsulated micro-channel PV/T solar collector (evaporator) can absorb thermal energy from both ambient air and solar radiation and therefore achieve high COP HP , electric efficiency and COP pvt. Even under cold weather conditions, the proposed solar collector and heat pump heater demonstrate high efficiencies, heating and power generation capacities. When ambient temperature is −18.6 °C and solar irradiance is 322 W/m2, the collector efficiency and electric efficiency of UMC-PVT-SC are still at 0.718 and 0.244, respectively, and the COP HP and COP pvt of the heat pump heater are 3.5, 5.63, respectively. The present work is of potential value for delivering net zero. • A novel uninsulated micro-channel photovoltaic/thermal solar collector is designed. • The photovoltaic/thermal solar collector can absorb heat from air without sun. • The overall energy efficiency of photovoltaic/thermal solar collector can reach 1.86 in winter. • It is a simple and low-cost solution of the combination of solar energy and heat pump. • The solar assisted heat pump can operate independently without external electric power. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Renewable energy generation and its integration with the built environment are becoming one of the main concerns of the global construction industry. It is believed that this solution is essential in addressing the growing challenges of global energy scarcity and the consequences of greenhouse gas effect. Buildings are the major end-users of energy worldwide; therefore, any measures implemented by the industry to generate and apply renewable energy should lead to the target cuts in CO2 emissions. Kazakhstan, as a member of the international community, is not an exception. Rapid economic growth and associated booms in the construction industry have caused a sharp increase in energy usage, simultaneously causing a significant negative impact on the environment. The government is seeking ways of learning and transferring international knowledge and experience in this field to cope with the above mentioned challenges. Thus, this work outlines and discusses modern building design strategies and measures and the use of renewable technologies, with specific focus on countries with cold climates. It also attempts to develop up-to-date expertise on renewable energy integration into contemporary buildings. Among others, these include the use of alternative and low impact, renewable energy forms such as solar, wind, geothermal, and biomass energy. A case study was conducted in order to test the hypothesis that renewable energy technologies, solar photovoltaic (PV) systems in particular, can be a sensible and practical solution to reduce the building sector's energy use from the grid and subsequently diminish carbon dioxide emissions. Thus, the paper has attempted to estimate energy usage of a building model with and without installation of a PV system and makes a basic economic calculation based on approximate market prices for installation and maintenance. This has allowed an estimation of estimating the approximate payback periods and make conclusions on the rational of integration of this solar energy technology in Kazakhstan (for cold, as well as, warm temperatures). Findings have shown that with present underdeveloped PV market and prohibitively expensive initial cost, the payback period is far more than it is in developed countries. A number of recommendations have been made to the government of Kazakhstan to make this technology more applicable and financially viable. [ABSTRACT FROM AUTHOR]

The overall punctuality of the railway system is of particular importance for customers in order to use trains as a means of public transport. Investigating the drivers of low punctuality of trains is an essential step for improving their punctuality. Severe weather conditions are assumed to be one of the drivers of delays and low punctuality of the transportation system. This paper addresses the extent to which the weather factors such as temperature, snow, precipitation and wind influence the punctuality of trains on the Norwegian railways. The data for the study are collected from the passenger trains on the Nordland Line. The study period is 10 years, from the beginning of 2007 to the end of 2016. Data are analysed on a daily and weekly basis, and correlation and regression analyses are used to perform the statistical analysis. The results show that extreme cold weather during the winters is a crucial influencing factor contributing to delays and low punctuality. We also found that the weather variable that best explains variations in punctuality of passenger trains on this line is snow depth. [ABSTRACT FROM AUTHOR]

Purpose - This paper aims to deal with the thermal resistance of multilayer nonwovens. The effect of fibre denier, cross-sectional shape and positioning within the layers were analysed with respect to the thermal resistance. Moreover, effect of compression on thermal resistance of the multilayer nonwoven structure have also be studied. Design/methodology/approach - The study involves multiple layering of thermal bonded nonwoven webs and the effect of fibre denier and positioning of different nonwovens from the hot plate. To avoid the increase in thermal resistance because of the air gaps between layers, the nonwovens were enclosed within an acrylic frame to compress them to a thickness of 12 mm. Compressional behaviour of the nonwovens were tested at a rate of 5 mm/min with peak compressive load of 50 N.Multilayer nonwoven assemblies were tested for thermal resistance with compressive pressure of 3.5 gf/cm2 and compared with that tested at zero pressure. Findings - In the study, three-layered nonwoven structure, provided better thermal resistance than their single component counterparts. The structural characteristic of the multilayer nonwovens affected the conductive, convective and the radiative heat transfer. In a multi-layer nonwoven, the top most layer should have the finest fibre as possible. Second preference may be given to the middle and followed by bottom layers in terms of fibre fineness. However, fine solid fibres performed poorly in terms of compression and recovery resulting in poor thermal resistance under compressive load. Originality/value - The experimental approach of controlling thickness while evaluating the thermal resistance will help in nullify the effect of air gaps between the layer interface, thus focussing on the effect of fibre denier and the positioning of nonwovens. This paper also discusses the unique properties of fine solid fibre and hollow fibres and their role in providing better thermal insulation for extreme cold weather applications. [ABSTRACT FROM AUTHOR]

In winter, wind turbines often face the risk of blade icing, and traditional methods – which mostly rely on manual observation and sensors – are limited by the experience of testers and costs; therefore, they are not widely used in practice. With the development of artificial intelligence, data-driven methods have garnered increased attention. However, it is challenging to mine the effective hidden information within data. In this regard, this paper proposes a wind turbine blade icing detection method based on feature engineering and the PSO-ConvLSTM-Transformer. Firstly, feature engineering is carried out with the help of expert experience to construct the mechanism variables related to icing; secondly, the ConvLSTM-Transformer prediction model is constructed to mine the timing information between supervisory control and data acquisition (SCADA) data, and finally, the model hyper-parameters are optimized by using the particle swarm optimization (PSO) algorithm to improve the diagnostic performance and generalizability of the model. The proposed model is evaluated using two wind turbine blade icing datasets. The proposed PSO-ConvLSTM-Transformer has significant advantages over multiple baseline models. This study can inform wind farm operations in terms of optimizing maintenance strategies, ensuring the safe and efficient operation of wind turbines in cold weather conditions. • Constructing ConvLSTM-Transformers deep learning model for wind turbine icing detection. • Explored the impact of domain knowledge-based icing mechanism features on deep neural networks. • Tested the effect of different optimization algorithms on the performance of deep learning models. [ABSTRACT FROM AUTHOR]

In order to clarify the actual operation effect of the comprehensive environmental performance of the existing residential buildings after the green retrofitting in the severe cold and cold zones, this paper selects the existing residential buildings of typical city in the severe cold zone as the research object, using the established evaluation method—EM-GRERB (Evaluation Method of Green Retrofitting for Existing Residential Buildings in severe cold and cold zones) and through field investigation and field measurement, the comprehensive environmental performance improvement of the project is confirmed. The results show that the degree of green retrofitting of the project is not obvious, need to further enhance the green retrofitting effect. This paper further analyzes the problems existing in the green retrofitting of the project, and puts forward the green retrofitting program, which provides a reference for the green retrofitting of the existing residential buildings in severe cold and cold zones. [ABSTRACT FROM AUTHOR]

In the significant part of the territory of Russia and other northern countries, the snowstorm is a frequently observed hazardous meteorological phenomenon. The significant duration of the cold period and the presence of vast snow areas as well as synoptic and orographic factors that cause the formation of strong winds, create the conditions for the snowstorm activity in the most part of Russia. In the present paper, an algorithm is proposed of the snowstorm forecast (separately for overall and ground snowstorms) for Murmansk region and Central Federal District based on the data of WRF-ARW modern hydrodynamic regional model used in the operational practice in the Hydrometcenter of Russia. [ABSTRACT FROM AUTHOR]

This paper describes seasonal peculiarities of modern climate warming in the European region. It is shown that warming scenarios considerably differ in cold and warm periods of the year. The warming is accompanied with growth and considerable change in the phase of the yearly cycle in solarity data. A strong half-year cycle is recognized in seasonal variation of long-term trends over the last few years. Peculiarities of climate change in Europe and the increased influence of the tropics are discussed in view of the results obtained. [ABSTRACT FROM AUTHOR]

This paper considers the problem of hedging inventory risk for a seasonal product whose demand is sensitive to weather conditions, such as the average seasonal temperature. The newsvendor not only decides the order quantity, but also adopts a weather hedging strategy. A typical hedging strategy is to use an option (weather derivative) that is constructed on a weather index before the season begins, which will compensate the buyer of the option if the actual seasonal weather index is above (or below) a given strike level. We adopt the risk measure of Conditional-Value at Risk ( $$\hbox{CVaR}$$) and explore the joint decision problem in mean-CVaR criterion. We find that the weather derivative hedging can increase order quantity. Furthermore, it can help the risk-averse newsvendor improve both expected overall and downside profits. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibet railway, the highest railway in terms of elevation, was built under the harshest of weather conditions in the world. A new technique, called the ventiduct embankment, was used for the first time in railway construction in the Qinghai-Tibet permafrost region of China to overcome the specific difficulties of the permafrost plateau. To evaluate its effectiveness, several full-scale test embankments were constructed at a representative field site, the Qingshuihe experimental section. The effectiveness of the ventiduct embankment structure has been verified by comparing it with the performance of the nearby control embankment in terms of permafrost table, settlement, and thaw depth. These observations are presented in this paper. The ventiduct embankment structure based on this study has been adopted in Qinghai-Tibet permafrost railway construction. [ABSTRACT FROM AUTHOR]

The aim of this paper is focused on the energy performance of buildings containing massive wall alternatives. The analysis comprised the comparison of the heating and cooling loads of seven characteristic wall configurations of one sample building with different dynamic internal heat capacity (ISO 13790:2008) in spite of the equal thermal resistance. The equal thermal resistance, as derived from simple steady-state condition, was imposed in order to allow research of effects solely attributed to the wall heat capacity on the building performance. A detached one floor dwelling exposed to different climate conditions in Portugal was analysed to illustrate the effect of the same wall in terms of energy demand during cold and hot weather conditions. A whole building dynamic modelling using EnergyPlus was employed for the energy analysis. The best thermal performance was obtained with massive walls that were located at the inner side, for a very heavy weight building and high building time constant. [ABSTRACT FROM AUTHOR]

Cold weather remains one of the least explored environmental phenomena in the historiography of American slavery. By detailing the heightened vulnerabilities of the enslaved during the colder portions of the year and then describing the means by which enslaved people leveraged frigid weather against slaveholders, this paper highlights how slave and slaveholder differently mobilized the cold against one another in contests over power. It argues that in the lives of enslaved women and men in antebellum Maryland, cold weather was both an afflicting as well as empowering force. [ABSTRACT FROM PUBLISHER]

Extreme cold weather conditions affect construction workers' health and safety performance. Hence, the goal of this article is to identify and analyze these challenges so that effective measures can be developed and implemented to mitigate or eliminate them. To this end, a questionnaire was created and circulated through the online platform QuestionPro. The Kruskal–Walli's test was used to examine the physical and mental health issues identified by the 111 responders, and quantitative analysis was performed by using physiological indicators such as heart rate and personal indicators, including degree of comfort and acclimation. The results showed that physical obstacles such as hypothermia and respiratory issues were perceived differently based on heart rate and garment comfort; and mental issues, such as poor concentration and frequent mood swings, varied with the workers' heart rate and level of acclimatization. Some of the strategies developed for protecting the workers are ensuring that they wear sufficient layers of clothing and heated gloves and have access to technologies such as infrared heaters. Existing practices and legislation that control construction "workers" safety in extreme cold weather conditions are also addressed. The findings of this article will help construction industry professionals effectively manage projects while ensuring their workers' safety in harsh cold weather conditions. [ABSTRACT FROM AUTHOR]

A long growing season, mediated by the ability to grow at low temperatures early in the season, can result in higher yields in biomass of crop Miscanthus. In this paper, the chilling tolerance of two highly productive Miscanthus genotypes, the widely planted Miscanthus × giganteus and the Miscanthus sinensis genotype 'Goliath', was studied. Measurements in the field as well as under controlled conditions were combined with the main purpose to create basic comparison tools in order to investigate chilling tolerance in Miscanthus in relation to its field performance. Under field conditions, M. × giganteus was higher yielding and had a faster growth rate early in the growing season. Correspondingly, M. × giganteus displayed a less drastic reduction of the leaf elongation rate and of net photosynthesis under continuous chilling stress conditions in the growth chamber. This was accompanied by higher photochemical quenching and lower nonphotochemical quenching in M. × giganteus than that in M. sinensis 'Goliath' when exposed to chilling temperatures. No evidence of impaired stomatal conductance or increased use of alternative electron sinks was observed under chilling stress. Soluble sugar content markedly increased in both genotypes when grown at 12°C compared to 20°C. The concentration of raffinose showed the largest relative increase at 12°C, possibly serving as a protection against chilling stress. Overall, both genotypes showed high chilling tolerance for C plants, but M. × giganteus performed better than M. sinensis 'Goliath'. This was not due to its capacity to resume growth earlier in the season but rather due to a higher growth rate and higher photosynthetic efficiency at low temperatures. [ABSTRACT FROM AUTHOR]

Heavy snow associated with low temperatures and wind intensification are phenomena typically manifested during winter, in southwestern Romania. The occurrence of such events in the last decade of the month of March, when spring should already be installed, generates severe weather episodes with negative impact on the socio-economic activity. One such episode manifested in the interval between 25th and 29th of March 2013. Seriousness of such an episode being mainly shown by the damage caused in the agricultural sector, as the plants were in the early stages of development, alerady. This paper presents a synoptic and climatological analysis of the given month (March 2013), including the mesoscale and local synoptic conditions, which favored these extreme weather phenomena in Oltenia. [ABSTRACT FROM AUTHOR]

It is usually thought that adequate winter chill is required for the full flowering of many temperate woody species. This paper investigates the sensitivity of blackcurrant bud burst and flowering to natural weather fluctuations in a temperate maritime climate, and compares a range of chill models that have been proposed for assessing the accumulation of winter chill. Bud break for four contrasting cultivars are compared in an exceptionally cold and in a mild winter in Eastern Scotland. The results confirm the importance of chilling at temperatures lower than 0°C and demonstrate that no single chilling function applies equally to all blackcurrant cultivars. There is a pressing need for further model development to take into account the relationship between chilling temperatures and warming temperatures occurring both during and after the chill accumulation period. [ABSTRACT FROM AUTHOR]

The use of circular hollow steel members has attracted a great deal of attention during past few years because of having excellent structural properties, aesthetic appearance, corrosion and fire protection capability. However, no one can deny the structural deficiency of such structures due to reduction of strength when they are exposed to severe environmental conditions such as marine environment, cold and hot weather. Hence strengthening and retrofitting of structural steel members is now very imperative. This paper presents the findings of a research program that was conducted to study the bond durability of carbon fibre-reinforced polymer (CFRP) strengthened steel tubular members under cold weather and tested under four-point bending. Six number of CFRP-strengthened specimens and one unstrengthened specimen were considered in this program. The three specimens having sand blasted surface to be strengthened was pre-treated with MBrace primer and other three were remained untreated and then cured under ambient temperature at least four weeks and cold weather (3 °C) for three and six months period of time. Quasi-static tests were then performed on beams to failure under four-point bending. The structural response of each specimen was predicted in terms of failure load, mid-span deflection, composite beam behaviour and failure mode. The research outcomes show that the cold weather immersion had an adverse effect on durability of CFRP-strengthened steel structures. Moreover, the epoxy based adhesion promoter was found to enhance the bond durability in plastic range. The analytical models presented in this study were found to be in good agreement in terms of predicting ultimate load and deflection. Finally, design factors are proposed to address the short-terms durability performance under cold weather. [ABSTRACT FROM AUTHOR]

This paper aims to study the winter heating performance of the air source heat pump (ASHP) system in cold regions. To this end, a winter operation performance test platform of the ASHP was built in an office building of a university in Zhangjiakou area. In the heating season of 2017-2018, the field test on performance parameters such as heating capacity and power consumption of the ASHP system were conducted. The results showed that the ASHP system used in the test can operate normally in extremely cold weather conditions in Zhangjiakou area; the indoor temperature during the ASHP operation meets the winter heating requirements; the coefficient of performance (COP) during the deep cold period was between 1.32 and 3.29; with the outdoor temperature reduced, the heat pump defrosting and oil return process is one of the main factors for energy consumption increase; when the outdoor temperature is high, 10-hour operating mode can save more power compared to the full-day operation; when the outdoor temperature is low, it does not necessarily save more. The research findings provide a valuable reference for the application and improvement of the ASHPs in cold regions. [ABSTRACT FROM AUTHOR]

One of the most significant challenges facing optimization models for the demand-side management (DSM) is obtaining feasible solutions in a shorter time. In this paper, the DSM is formulated in a smart building as a linear constrained multi-objective optimization model to schedule both electrical and thermal loads over one day. Two objectives are considered, energy cost and discomfort caused by allowing flexibility of loads within an acceptable comfort range. To solve this problem, an integrative matheuristic is proposed by combining a multi-objective evolutionary algorithm as a master level with an exact solver as a slave level. To cope with the non-triviality of feasible solutions representation and NP-hardness of our optimization model, in this approach discrete decision variables are encoded as partial chromosomes and the continuous decision variables are determined optimally by an exact solver. This matheuristic is relevant for dealing with the constraints of our optimization model. To validate the performance of our approach, a number of simulations are performed and compared with the goal programming under various scenarios of cold and hot weather conditions. It turns out that our approach outperforms the goal programming with respect to some comparison metrics including the hypervolume difference, epsilon indicator, number of the Pareto solutions found, and computational time metrics. [ABSTRACT FROM AUTHOR]

The influence of weather conditions during the cold period of year on microclimate parameters of cowsheds and on the milk productivity of cows kept in traditional tethered conditions in typical brick cowsheds with natural ventilation was determined. It was established that in the conditions of Ukraine the temperature in cowsheds during the cold period of the year significantly depends on: the number of cows in them (r = 0.509; p = 0.018); the number of livestock per unit volume of the cowshed (r = 0.68; p = 0.001); the area of ventilation holes (r = 0.745; p<0.001). The humidity inside the cowsheds is most dependent on the outdoors air humidity (r = 0.514; p = 0.017), as well as on the number of cows per unit volume of the cowshed (r = 0.533; p = 0.013). In the cold period of the year the most problematic from the point of view of comfort for animals are periods of severe frosts. When cows were kept on a tether in typical brick cowsheds with natural ventilation and walking areas, the correlation coefficients between gross milk yield and: the average temperature outdoors were in the range of r = 0.625...0.636 (p<0.001); atmospheric pressure - r = -0.237...-0.276 (p≤0.001). A significant synchronicity of fluctuations in time of outdoor air temperature indicators and average milk yield per cow was established at periods of severe frosts: the decrease in daily milk yield due to frost reached 0.8 ... 2.2 kg per day (up to 21%). Cluster analysis established that for the synchronous distribution of days of the cold period into groups (clusters) based on the average outdoors night air temperature (tv) and gross milk yield (valmol), it is expedient to distribute the sample into 3 gradations. [ABSTRACT FROM AUTHOR]

This paper describes an improved edition of the climate division dataset for the conterminous United States (i.e., version 2). The first improvement is to the input data, which now include additional station networks, quality assurance reviews, and temperature bias adjustments. The second improvement is to the suite of climatic elements, which now includes both maximum and minimum temperatures. The third improvement is to the computational approach, which now employs climatologically aided interpolation to address topographic and network variability. Version 2 exhibits substantial differences from version 1 over the period 1895-2012. For example, divisional averages in version 2 tend to be cooler and wetter, particularly in mountainous areas of the western United States. Division-level trends in temperature and precipitation display greater spatial consistency in version 2. National-scale temperature trends in version 2 are comparable to those in the U.S. Historical Climatology Network whereas version 1 exhibits less warming as a result of historical changes in observing practices. Divisional errors in version 2 are likely less than 0.5°C for temperature and 20 mm for precipitation at the start of the record, falling rapidly thereafter. Overall, these results indicate that version 2 can supersede version 1 in both operational climate monitoring and applied climatic research. [ABSTRACT FROM AUTHOR]

This paper uses the comparative method in order to highlight the thermal anomalies, the impact of atmospheric circulation and the air masses through specific situations. Our preliminary study employs radio sounding data from Bucharest-Băneasa weather station, and this method is applied for an altitude interval bounded by Earth's surface and the geopotential surface of 900hPa. Thus, the results have been obtained from radio soundings up to the 900 hPa level, which corresponds to an altitude of 1000 meters, because above this level, there is a tendency towards generalization due to the decreased influence of the subjacent active surface and the impact of the particularities of the general atmospheric circulation above Bucharest. The aim of the study was to explain the temperature distribution through statistical shape/form indices and to measure their degree of flattening and asymmetry. Processing the radio - soundings data complemented, when not measured, by the remote sensing data available after 2007, involved the statistical modeling of time series for the cold season (October to March), which meant analyzing the temporal variations and the prognosis for the evolution of meteorological and climatic elements. A comparison of the values taken by different parameters of the analyzed thermal regime could not be achieved without a more detailed presentation of the thermal regime up to 900 hPa, by entirely taking into account thermal anomalies, exceptional thermal gradients and the altitude/height of isotherms directly involved in the analyzed phenomenon, and also by directly correlating these elements with the characteristic synoptic situations. [ABSTRACT FROM AUTHOR]

In the autumn of 2013, in Oltenia, weather evolution has been marked by an exceptional variability with fast transitions from a warm weather to an extremely cold and even excessively cold in some intervals and from an excessively rainy weather to a droughty weather. These fast transitions from one extreme to another of weather aspect are due to the increase of climatic variability, an aspect which is directly connected to climatic global warming. After the warmish summer of 2013, in the end of August, beginning with August 24, a cooling process has begun which has slowly continued during the whole month of September and has strengthened in the last two days. The cooling climax was registered in the interval October 4-5, when negative thermal minimum values were registered, frost in the air and ground and early hoarfrosts which affected crops, especially the vegetable crops. In November the high daily air temperature means led to gradual enforcements, and in the end of the month the autumn crops were in advanced development stages, and in rape the floral stems and studs appeared. The intense weather cooling and snowfalls were registered in the interval November 26-28 2013 which constituted a serious climatic hazard, surprising the unadapted crops to the intense weather cooling. The snow layer reached 22 cm in Caracal in Romanați Plain. The analysis of the climatic conditions in the south-west of Romania in the autumn of 2013 is a continuation of some extended studies on climate variability. The paper is useful to specialists, doctoral candidates and master graduates and to all people interested in the climate's evolution (Bogdan, Marinică, 2007, Marinică et al. 2012, 2013, Sandu et al. 2012). [ABSTRACT FROM AUTHOR]

In this paper we document dense water formation throughout the Adriatic shelf and coastal area in January/ February 2012, resulting in record-breaking densities observed during and after the event. The unprecedented dense water generation was preconditioned by a dry and warm year which resulted in a significant reduction of coastal freshwaters, superimposed on a long-term basin-wide salinity increase. The final event that triggered the dense water formation was an extended period of cold weather with strong and severe winds. Record-breaking potential density anomalies (above 30 kg m-3) were measured at several formation sites. Accumulated surface net heat and water losses in some coastal regions exceeded 1.5 GJ m-2 and 250 kg m-2 over 21 days, respectively. Excessiveness, importance of shelf-type dense water formation and effects on the thermohaline circulation and deep aquatic systems are discussed. [ABSTRACT FROM AUTHOR]

This paper is a review of studies of abrupt climate changes (ACCs) during the Holocene published during the past ten years. North Atlantic cold events are indicators of ACCs. As indicated by North Atlantic ice-rafted debris (IRD), there were nine confirmed cold events during the Holocene, occurring at 11.1 kyr, 10.3 kyr, 9.4 kyr, 8.1 kyr, 5.9 kyr, 4.2 kyr, 2.8 kyr, 1.4 kyr, and 0.4 kyr respectively according to most representative results from Bond et al. (1997). However, the identification of chronology has been made with some uncertainties. Considerable climatic proxy data have shown that, during the cold events, substantial climate abnormalities have occurred widely across the globe, particularly in the areas surrounding the North Atlantic. These abnormalities were in the form of high-latitude cold in the both hemispheres, expansion of the Westerlies to low latitudes, drought in the monsoon regions, recession of summer monsoons, and intensification of the winter monsoons. Studies have indicated that the four ACCs occurring in the early Holocene may be related to freshwater pulses from ice melting in the northern part of the North Atlantic, and the other five ACCs that occurred during the middle and late Holocene may be related to the decreased solar activity. [ABSTRACT FROM AUTHOR]

Inadequate and poorly maintained pavement markings are considered to be one of the largest contributing factors to fatal motor vehicle crashes. As a result, it is essential to apply the appropriate pavement marking material for all weather conditions in order to increase public safety and reduce motor vehicle crashes. Building a strategic plan to renew and re-stripe pavement marking is receiving increasing interest from companies/authorities that manage the pavement marking in order to reach the most cost-efficient management plan of the available pavement marking materials. The objective of this paper is to develop pavement marking performance models that predict the condition of different marking materials under various service conditions including weather, traffic and snow removal plans. The developed models are validated and the results show that the average percent validity varies from 87% to 99%. Marking performance is assessed using a condition rating scale, which numerically ranges from 1 to 5 and linguistically from excellent to critical, respectively. Deterioration curves are developed that assess the condition of the pavement marking based on the developed models. They are expected to benefit academics and practitioners (municipal engineers, consultants, and contractors) to prioritise inspection, stripping, and re-stripping planning for various pavement markings. [ABSTRACT FROM AUTHOR]

Pervious concrete pavement is a sustainable and environmentally conscious paving material. Use of pervious concrete pavement in freeze–thaw climates in Canada has been minimal to date. This paper describes the performance to date of five field sites in Canada. The test areas are monitored continually, starting at the construction stage, to understand the behaviour of pervious concrete in climates in Canada. Testing involves surface distress evaluations, permeability monitoring and evaluation of cast and cored samples. Winter and rehabilitative maintenance options are being performed and evaluated. Test areas are instrumented to track moisture movement through the pavement structure. The findings to date of this work indicate that freeze–thaw cycles are in general not the cause of distress development or failure. The areas that require the most attention to achieve success are the site design, mix design and construction stages. [ABSTRACT FROM AUTHOR]

Abstract In cold environments, flat plate solar collectors are of limited value because high heat losses lead to low efficiency. The integration of polymethyl methacrylate (PMMA) sheet into flat plate collector is presented in this paper. The performance of this collector in cold weather was investigated using a three-dimension simulation model. A simplified experiment was conducted to verify the precision of numerical model and the simulation data can agree very well with practical ones. The effects of the thickness and location for PMMA sheet on the performance of collector efficiency following steady state were analyzed. The transmittance of transparent insulation material is the key parameter to achieve high performance for the collector. The optimum thickness of the transparent insulation material is 1 mm in simulated conditions and the best location of PMMA sheet was achieved. The result shows that the increase of the collector efficiency from the conventional collector is 11.3%, when reduced temperature difference is equal to 0.1 m2 °C/W and the ambient temperature is −20 °C. Highlights • A 3D model for new designed flat-plate solar collector was developed. • The performance of the new designed collector was simulated in cold weather conditions. • A parametric study was performed to optimize the system design. • The changes of natural convective for various collectors in the air gap were studied. [ABSTRACT FROM AUTHOR]

Abstract Constructions ageing is a relevant problem in developed country like Italy. In particular, in case of existing masonry buildings, retrofitting interventions aimed at improving structural and thermal performances represents an obvious need. At the same time, sustainability awareness of buildings life-cycle has grown in the last years. Consequently, the whole life-cycle of constructions should be analyzed and assessed during the design of retrofitting interventions. In order to take into account these aspects new design and planning methods are necessary. This paper presents an integrated approach to evaluate structural and thermal retrofitting strategies for masonry walls. Economic and ecological costs of each examined retrofitting solution are compared, taking into account thermal and seismic capacity demand of the construction site. Given the economic cost , a set of retrofitting solutions for masonry panels have been mapped with a couple of parameters (structural strength Vs thermal insulation). An analogous mapping, considering the ecological cost due to equivalent CO2 production, have been performed. A methodology to find the best solution among a set of retrofitting solutions is presented, depending on the location of the building and its seismic and thermal characteristics. Examples, based on six retrofitting techniques located in four different sites in Italy, are analyzed to explain the effectiveness and the feasibility of the proposed method. The comparison between ecological and economical cost allowed to highlight the characteristics of the different interventions. Thermal performance proved to be more important in cold weather conditions while structural retrofitting is preferable in high seismic risk areas. [ABSTRACT FROM AUTHOR]