Cold Countries Research Articles

HIGH-SOLID ANAEROBIC CO-DIGESTION OF FOOD WASTE AND DAIRY MANURE: A PILOT SCALE STUDY AT LOW-TO-MODERATE TEMPERATURE CONDITIONS

Treating organic solid wastes economically is a challenge, predominantly in cold and high-altitude regions. Objective of this research was to determine the operating strategies to reduce the start-up phase of high-solid anaerobic digestion (HSAD) process and to improve the digestion of food waste (mainly fruits and vegetable wastes [FVW]) with or without animal manure in a low-cost AD system at 20-25°C. In addition, this study aimed to obtain the basic design criteria for starting up of scaled-up HSAD system using adapted liquid inoculum. Inoculum to feedstock ratio was varied from 6:1 to 3:1. The organic loading rate (OLR) expressed as volatile solids (VS) and operational cycle length was varied from 0.44 -2.1 KgVS Kginoculum-1 d-1 and 33 -14d, respectively. Obtained results show that methane (CH4) production from FVW was feasible at low-to-moderate temperature and specific methane yield of 0.4-0.6 L gVS-1 was observed even at high OLR. CH4 conversion rates and its quality were not affected, while maintaining the operational stability (e.g. no acidification or VFA accumulations). CH4 content reached over 60Ϻnd remained almost steady. Results also suggest that HSAD process at 25°C is comparatively efficient in saving heat energy and at the same time obtains the CH4 values close to mesophilic conditions. This means that the smaller size digester (in the case of HSAD) is preferred as there is no waste dilution involved and also suitable for cold countries. Using this concept, livestock producers can play a role in reducing GHG emissions while also earning C-offset credits.

Acute clouding of trifocal lens during implantation: a case report

BackgroundIntraoperative IOLs clouding of several kinds of hydrophilic acrylic intraocular lenses (IOLs) have been reported due to temperature changes. This phenomenon reported previously occurred in cold countries and during the winter months. However, no clinical case was reported about trifocal IOL opacification during operation. We report a case in which acute opacification of the optical region occurred simultaneously when AT LISA tri 839mp(Carl Zeiss) was implanted into the eye.Case presentationA 79-year-old woman with a cortex and nucleus cataract was scheduled to undergo right eye phacoemulsification assisted by femtosecond technique. The trifocal lens (AT LISA tri 839mp), which is made of hydrophilic acrylic (25%) with hydrophobic surface properties, was chosen for implantation. As the IOL was implanted into the eye, it became cloudy immediately. Then it was replaced by another AT LISA tri 839mp, which was transferred from lens company outside, the same phenomenon was observed. These two lenses underwent the same temperature fluctuation from cold outside to operating room. Finally, a ZCB00 (Allergan) was implanted.ConclusionsThe acute intraoperative clouding of trifocal lens(AT LISA tri 839mp) results from fluctuation of temperature should be noticed.

Adsorption cycle “heat from cold” for upgrading the ambient heat: The testing a lab-scale prototype with the composite sorbent CaClBr/silica

Adsorptive transformation of heat is an emerging technology that is especially promising for low-temperature heat sources. Recently, an adsorption cycle (the so-called “Heat from Cold” or HeCol) has been suggested for upgrading the ambient heat in cold countries. This paper addresses the selection of composite sorbents of methanol specialized for this cycle and the study of their sorption properties. First, we analyzed which adsorbent is optimal for the HeCol cycle and how its properties depend on the HeCol cycle boundary temperatures. Then, three composite sorbents, based on CaCl2, CaBr2 and their mixture confined inside the silica gel mesopores, were prepared and their sorption equilibrium with methanol was analyzed keeping in mind the HeCol cycles with various boundary temperatures. It was shown, that these composite sorbents exchange up to 0.48 g of methanol per 1 g of the composite that far exceeds this value for common activated carbons. Finally, a first lab-scale HeCol prototype was built and tested with one of the studied sorbents, namely CaClBr/SiO2, to evaluate the feasibility of the cycle.

Causes of energy poverty in a cold and resource-rich country: evidence from Kazakhstan

ABSTRACTKazakhstan is an upper-middle-income country and one of the coldest countries in the world with rich energy resources and energy prices considerably lower than in developed countries. This paper presents the first comprehensive overview of household fuel use in Kazakhstan and assesses the causes and extent of energy poverty using the Households Living Conditions Survey dataset of 12,000 households. The results show that there is an overwhelming reliance on coal in Kazakhstan: 40% of all surveyed households use coal for heating, cooking and other needs. In general, liquefied petroleum gas is mainly used for cooking, coal and firewood for heating, while electricity is rarely used for heating. Energy poverty was less prevalent in oil and gas rich regions, due to low gas prices and higher income levels in those regions, while households located in the North Kazakhstan, Central and East Kazakhstan mainly suffer from lack of cleaner fuel options, income poverty, longer and colder winters and consequently energy affordability. Despite low energy prices in Kazakhstan, the results demonstrate that 28% of surveyed households spend more than 10% of their income on energy. Gas and district heating infrastructure coverage and income inequality across its regions contributed the most to energy poverty in Kazakhstan. Energy prices are regulated and indirectly subsidised. Removing energy subsidies alone may worsen energy affordability of households. Offering direct subsidies to cover part of the energy expenditures may not fully solve the problem, but subsidies, interventions for efficient technologies and fuels, dwelling energy-efficiency improvements are necessary.

What Time Do We Dine?”- A Cultural Study To Evaluate People’s Views Of Set Meal Times Across Countries

Clinical Outcome Assessments (COAs) use names of mealtimes to refer to specific periods of the day, without specifying a given hour(s); this could lead to the intended timeframe being interpreted differently depending on country of origin. This study aims to assess how national differences in eating habits impact on respondent interpretation of these time periods. 49 participants across 22 countries were asked to identify when they typically eat their morning, midday and evening meal. The responses were assessed to ascertain similarities and differences between countries, and whether an indication of a set time is preferable alongside the meal name in COAs to ensure more consistent interpretations and responses. The responses indicate the variance in timings: Morning meal: range 0600 – 1200. 42% of these responses indicated it would be eaten between 0800 and 0900; 12% of all responses indicating 0600, and <1% indicating 1200. Midday meal: range 1100 – 1700. 83% of these responses indicated it would be eaten between 1200 and 1400; 3% of all responses indicating 1100, and 2% indicating 1400 – 1500. Evening meal: range 1700 – 2300. 25% of these responses indicated it would be eaten at 1900; 10% of all responses indicating 1700, and 5% indicating 2300. Meal times vary greatly across countries, indicating trends due to national and cultural differences. Participants from hotter climes, e.g. Greece, Italy and India typically stated the evening meal would take place between 2000 and 2200; whereas colder countries e.g. Denmark, the UK and Canada stated typically the same meal would be between 1700 and 1900. Respondents interpret meals to occur at different times, spanning a range of 6 hours per meal, depending on country of origin. To enable accurate data pooling, it is optimal to include a reference to the meal alongside a specific time range in COAs.

Channeling the Country’s Image: Illustrated Magazine Yugoslavia (1949–1959)

This paper briefly reviews and discusses the contents of the illustrated magazine Jugoslavija (Yugoslavia), published from 1949 to 1959, and edited by prolific Yugoslav intellectual and artist Oto Bihalji-Merin. This edition is critically examined as a means of creating an image of Yugoslavia in the years of momentous political and social changes in Yugoslav society, and during the height of the Cold War and country’s realignment in international relations. Serving also as a cultural window to the outside world, Jugoslavija promulgated concepts of a specific Yugoslav modernity, ethnic and national diversity, and a ‘third position’ on the global political and cultural map of the 1950s.

“Heat from Cold” – A new cycle for upgrading the ambient heat: Adsorbent optimal from the dynamic point of view

A new adsorptive cycle has recently been suggested for upgrading a temperature potential of the ambient heat in cold countries (the so-called “Heat from Cold” or HeCol cycle). Because of the low operating temperature and pressure, a special attention has to be paid on dynamic aspects of the HeCol cycle. In this paper, we analyze which adsorbents are optimal for the HeCol cycle from the dynamic point of view. Appropriate recommendations are made.

Control strategies for Energy Recovery Ventilators in the South of Europe for residential nZEB—Quantitative analysis of the air conditioning demand

Mechanical ventilation systems are essential for ensuring the indoor quality of air in nZEB (nearly Zero Energy Buildings) with a high level of airtightness. In cold countries, it has already been demonstrated that Heat Recovery Ventilators (HRV) recovering the sensible energy from air ventilation are needed to achieve the energy demand goals for nZEB set by Passivhaus. In tropical areas with hot temperatures and high relative humidity in the ambient air, the necessity of recovering latent and sensible energy with Energy Recovery Ventilators (ERV) has also been demonstrated. However, in warm climates with medium relative humidity levels, for example in cities located on the Mediterranean coast, the evaluation of the effectiveness of an EVR for residential buildings has to be analyzed and optimized.This article establishes the effectiveness of several control strategies for ventilation air systems including ERV with the aim of optimizing the air conditioning energy demand of dwellings located in several cities in the South of Europe. Possible control strategies have been analyzed to minimize the undesirable operation of ERVs which could otherwise increase the air conditioning energy demand for winter and summer seasons. The impact of the latent effectiveness and the effect of free-cooling on the air conditioning energy demand is also studied.

Changes of effective temperature and cold/hot days in late decades over China based on a high resolution gridded observation dataset

ABSTRACTThe effective temperature (ET) is employed to investigate observed changes of thermal comfort conditions over China during the late decades of the historical observational period. ET considers the aggregate effects of temperature, relative humidity, and wind speed to describe the human thermal sensitivity to weather and climate. The data used in the study is the recently produced gridded daily scale dataset CN05.1, which covers the period of 1961–2014 at a resolution of 0.25° latitude by 0.25° longitude. Results show a general increase of ET in both December‐January‐February (DJF) and June‐July‐August (JJA). The increase is mostly caused by an increase of temperature and a decrease of wind speed, while the contribution from relative humidity is small. As measured by ET, China is a cold country with many more cold days than hot days. Large decreases of cold days and increases of hot days are found following the increase of ET. The number of comfortable days shows larger values in the warm areas and during the warm seasons. During the analysis period, the number of annual comfortable days shows an increasing trend when considering the China‐wide average. However, the number of annual comfortable days during JJA decreases over warm areas.

Design of Frost Resistant Pavement Structure Based on Road Weather Stations (RWSs) Data

Frost is a decisive factor influencing pavement performance in cold countries. In the EU, millions of euros are spent annually on winter maintenance. About one-third of the maintenance budget is allocated to rehabilitation due to the negative impact of frost. The negative effect of frost is restricted by using non-frost-susceptible materials within the frost zone and regulating water accumulation. However, experience shows that the thickness of constructed pavement structure is often inadequate and that frost penetrates into the subgrade of frost-susceptible materials. The aim of this paper is to introduce the thickness calculation approach of the frost resistant pavement structure using road weather station (RWS) data. The subgrade susceptibility to frost and the number of equivalent single axle loads (ESALs) are considered as factors too. The calculated thickness of the frost resistant pavement structure is corrected according to the specific local conditions. After performing a statistical analysis of 2012–2014 data pertaining to 26 RWSs, Lithuania was divided into four regions according to the maximum frost depths, where the maximum values depending on RWS location varied from 110.4 cm to 179.1 cm.

Psychrophilic anaerobic digestion of semi-dry mixed municipal food waste: For North American context

Treating municipal organic solid wastes economically is a challenge, predominantly in cold and high-altitude regions, where the temperature can be below 20°C. The aim of this research was to improve the anaerobic digestion (AD) of food waste (FW) with or without animal manure in a low-cost psychrophilic anaerobic digestion in sequencing batch reactor (PADSBR) at 20°C. Feed solid content was varied from 37% to 13%, mainly to validate the stability of digestion process suitable for different scenarios and OLR was increased from 0.8 to a maximum of 4.2kg VS/m3d. Results showed that methane production from FW mixture was feasible at low-temperature and specific methane yield of 0.401±0.01m3 CH4/kg VSfed was observed even at high OLR. When loading rates applied to bioreactors were increased by 225%, methane conversion rates decreased only by 10%, while maintaining the operational stability (e.g. no foaming, no acidification). Methane content was constantly in the range of 64–69%, which shows the quality of biogas is excellent and remained almost steady. The results suggest that PADSBR at 20°C is comparatively efficient in saving the heat energy and at the same time obtains the CH4 values close to mesophilic/thermophilic conditions. This concept is particularly vital for cold countries facing energy constrains.

Evaluation of frost heave and moisture/chemical migration mechanisms in highway subsoil using a laboratory simulation method

Seasonal processes in cold countries significantly affect the engineering characteristics of highway subsoil over time. Cyclical freeze-thaw leads to changes in thermal and moisture conditions. As a result, road bearing capacity can progressively change from the initial design. In this work, a modified laboratory method was developed, with cyclical freeze-thaw of soil samples and simultaneous supply of deionised water and a de-icing agent (sodium chloride) to the base. The benefits of the test procedure included slow freezing, simulating the conditions that can be experienced by highway soils in cold environments, extended soil column heights and a larger number of identical soil samples, which allowed experimental variability to be assessed. The method included the monitoring of moisture and chemical mass transfer in the soils. Samples supplied with deionised water experienced ice segregation in their upper parts, and significant heave. While soils supplied with NaCl solution behaved in a similar fashion during their first freeze-thaw cycle, the second cycle saw a reduction in the rate of migration of the freezing front within the soils and also less ice segregation and less heave due to increased salinity. Salt was preferentially transferred upwards in the soil columns as a result of the thermal gradient, including negative pressure associated with cryosuction, and osmotic pressure. The new method provides a more realistic laboratory approach to assessing potential freeze-thaw impacts, and the effects of de-icing agents on soils beneath roads, and in different settings.

Elektrofüzyon Kaynaklı Polietilen 80 Kalite Doğalgaz Borularının Tokluğu

Standards used in electrofusion welding of polyethylene(PE) pipes, recommends to be carried out at the temperature range between -5oC and +30oC. However, when climatic conditions considered especially in cold countries and emergency situations when the welding process performed at lower ambient temperatures than specified; we need a detailed study about toughness of the weldments. For this purpose, medium density (PE80) pipes were joined with electrofusion welding method at the various environment temperatures (room temperature, 0oC and -30oC) as recieved. The impact resistance of weldments were investigated by Izod impact test and fracture surface inspection was carried out. As a result, the weldments impact resistance was determined to be affected by the ambient temperature.

Experimental Study of a Small Scale Hydraulic System for Mechanical Wind Energy Conversion into Heat

Significant potential for reducing thermal energy consumption in buildings of moderate and cold climate countries lies within wind energy utilisation. Unlike solar irradiation, character of wind speeds in Central and Northern Europe correspond to the actual thermal energy demand in buildings. However, mechanical wind energy undergoes transformation into electrical energy before being actually used as thermal energy in most wind energy applications. The study presented in this paper deals with hydraulic systems, designed for small-scale applications to eliminate the intermediate energy transformation as it converts mechanical wind energy into heat directly. The prototype unit containing a pump, flow control valve, oil tank and piping was developed and tested under laboratory conditions. Results of the experiments showed that the prototype system is highly efficient and adjustable to a broad wind velocity range by modifying the definite hydraulic system resistance. Development of such small-scale replicable units has the potential to promote “bottom-up” solutions for the transition to a zero carbon society.

The effect of real-time context-aware feedback on occupants’ heating behaviour and thermal adaptation

Studies have shown that building energy demand in identical dwellings could vary by a factor of three. Differences in occupant behaviour–i.e. purchase, operation and maintenance–have been implicated as a strong source of these differences. The literature suggests that feedback on energy use to building occupants–particularly real-time feedback–can be used to prompt lower operation-related energy behaviours. This is particularly true for thermal demand which, in cold countries, accounts for four times as much energy use as non-thermal demand. However, there is little evidence to support this claim. Further, there are concerns that the actions that allow occupants to lower heating energy use could negatively impact their comfort by lowering indoor temperatures or air quality below acceptable thresholds. We report results from a winter field study that used in-depth energy, environmental and motion sensing to generate real-time context-aware feedback through a smartphone application. Subjective data and clothing levels were concurrently collected through questionnaires. Our results suggest that real-time feedback could lower radiator and room temperatures without significantly affecting occupant thermal comfort. The results also show that real time feedback could contribute to an increase in occupant perceived environmental control (a key variable in the theory of adaptive thermal comfort) while prompting lower heating energy behaviours.

Effect of Freeze—Thaw Cycles on Mechanical Behavior of Lime-Stabilized Soil

Lime stabilization of clay soils is becoming, if not already, one of the most used construction techniques for road embankments and for subbase stabilization. In warm countries, lime stabilization is used without any problems; but in cold countries, some concerns are still present in relation to behavior of lime-stabilized soils at low temperatures, particularly in conditions of freezing and thawing. The research in this paper presents the results of an experimental campaign made on a typical Italian clay soil stabilized with lime. The research studies the evolution of mechanical performances of lime-stabilized soil under the effect of freeze and thaw cycles and after a series of several freezes and thaws. The results of the research clearly show that lime-stabilized soils can have proper mechanical performances after freeze and thaw cycles. In particular, the test campaign shows that lime-stabilized soils have decreased resistance after freeze and thaw cycles and that they almost fully recover their resistance if the temperature comes back constantly to 20°C.

Effect of radiator position and mass flux on the dryer room heat transfer rate

A room radiator as usually used in cold countries, is actually able to be used as a heat source to dry goods, especially in the rainy season where the sun seldom shines due to much rain and cloud. Experiments to investigate effects of radiator position and mass flux on heat transfer rate were performed. This study is to determine the best position of the radiator and the optimum mass flux. The radiator used was a finned radiator made of copper pipes and aluminum fins with an overall dimension of 220mm×50mm×310mm. The prototype room was constructed using plywood and wood frame with an overall size of 1000mm×1000mm×1000mm. The working fluid was heated water flowing inside the radiator and air circulating naturally inside the prototype room. The nominal mass fluxes employed were 800, 900 and 1000kg/m2s. The water was kept at 80°C at the radiator entrance, while the initial air temperature inside the prototype room was 30°C. Three positions of the radiator were examined. The results show that the effect of the mass flux on the forced and free convection heat transfer rate is insignificant but the radiator position strongly affects the heat transfer rate for both forced and free convection.

Images of the Russian People and Russia in the Contemporary English Novel

The mythological image of Russia in English fiction has been shaped and repeated over the course of many centuries. Russia was traditionally viewed as a distant, cold, unpredictable, and wild country. The aim of the article is to examine a new Russian cultural discourse that first appeared in English fiction in the early twentieth century and developed during the last decades of the twentieth and the first decade of the twenty-first centuries. Russia’s history in the twentieth century had a powerful impact on Russian themes in English literature. To prove this point, novels by three contemporary female English writers are analysed. In Penelope Lively’s The Moon Tiger (1987), Penelope Fitzgerald’s The Beginning of Spring (1988), and Helen Dunmore’s The Siege (2001) and The Betrayal (2011), Russian history is viewed sympathetically through the dramatic fates of normal people. The characters break down stereotypes and create a complex image of Russia and its people in contemporary English fiction.

A Comprehensive Review of Solutions and Strategies for Cold Start of Automotive Proton Exchange Membrane Fuel Cells

Proton exchange membrane fuel cell (PEMFC) can be a significant eco-friendly alternative power source for vehicles. However, under subfreezing conditions, cell degradation and irreversible performance decay can occur because of ice formation and repetitive thaw/freeze cycles. These problems have limited the further commercialization of PEMFC in cold weather countries. Thus, many improvements have been made to repair the freeze protection and rapid cold startup problems in PEMFC vehicles. In this paper, a comprehensive review dedicated to engineers of the recent research progress on the PEMFC cold start problems is presented. Systems and methods for fuel cell shutdown are summarized and classified into two categories: purge solution and material to avoid freezing. Regarding the system and solutions for PEMFC cold startup, different heating solutions are classified into two main groups depending on their heating sources and categorized as internal and external heating methods. This paper concludes with a detailed review of cold startup strategies based on an exhaustive survey of journal papers and patents.

Investigation of IAQ in Mechanically Ventilated Kindergartens and Elementary Schools in Korea

This study investigates the indoor pollutant levels in school buildings according to the operation of mechanical ventilation system. Three classrooms at two different elementary schools and four classrooms at two children's day care center in Korea were chosen for investigation of indoor air quality with mechanical ventilation systems. Measurements were conducted for particulate matter, formaldehyde, total volatile organic compounds, carbon monoxide, carbon dioxide, nitrogen dioxide, ozone, radon, and total bacteria counts. Differences in indoor pollutants concentrations with and without operation of ventilation systems in each classroom were analyzed. The results show that operation of ventilation systems could decrease the levels of indoor pollutants in the classrooms, especially showing the reduction of HCHO concentrations by 14.9-62.3%. representative samples in Singapore. This study reported that indoor CO 2 concentration levels were lower in Singapore child care centers when compared to child care centers from other cold climate countries due to the higher ventilation rate of child care centers in Singapore. St-Jean et al. (11) have assessed indoor air quality in 21 day care centers in Montreal, Canada and determined association between building characteristics and IAQ. They reported that over 85% of the day care centers had a mean CO 2 concentration higher than 1000 ppm. The mean formaldehyde concentration was 22.9 µg/m 3 . They also reported that the presence of a mechanical ventilation system and a large surface of play are per child were significantly associated with lower CO 2 levels. Chitra and Nagendra (4) have investigated indoor air quality parameters in a naturally ventilated school building located near an urban roadway in India. This study reported that the mean value of indoor PM 10 , PM 2.5 , PM 1 and CO concentrations were found to be 149 ± 69, 61 ± 29, 43 ± 24, 0.10 ± 0.18 and 95 ± 61, 32 ± 16, 18 ± 9 µg/m 3 , 0.11 ± 0.14 ppm, respectively for winter and summer seasons. Norback et al. (12) have studied the relationship between VOCs, respirable dust, and personal factors to prevalence and incidence of sick building syndrome in six primary schools. They reported that the average CO 2 concentrations in all sites were greater than 800 ppm and indicated inadequate ventilation. Lee and Chang (13) investigated IAQ of five classrooms in Hong Kong. This study showed that the average respirable suspended particulate matter (RSPM) concentrations were higher than the Hong Kong air quality objective (annual average, 55 µg/m 3