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The spread of the COVID-19 pandemic in 2020 has contributed a large impact on various economic sectors and the energy sector is no exception. In this paper, we analyze the time-varying correlation between COVID-19 shocks (positive and negative) and energy markets (natural gas, gasoil, heating oil, coal, and crude oil) in the time-varying environment. This study adds to the literature by implementing the Markov-switching dynamic copula with Student-t distribution to explore the unexpected COVID-19 pandemic shock effects on energy markets. Our results revealed that (i) there is evidence of correlation between COVID-19 shocks and all energy markets; (ii) the contributions of COVID-19 shocks on energy markets are not constant along 2020. (iii), there is evidence of a similar response of the energy markets to the positive and negative COVID-19 shocks.

Isolation is a separator between conductors in electrical equipment that prevents flashover, resulting in a short circuit or electrical failure. Isolation is critical in electrical appliances, exceptionally High Voltage Power Equipment (HVPE), to ensure the safety of circuit breakers, capacitors, and transformers. In addition to being an isolator, the insulating liquid material also serves to cool the heat generated by electrical appliances. Isolator with mineral oil-based transformer has various environmental issues, including non-biodegradability, non-renewability, and rarity. Because it is environmentally safe and extensively used, virgin coconut oil (VCO) is an alternative transformer oil insulation. This study aims to determine the properties of Virgin Coconut Oil (VCO) breakdown voltage using the IEC 156 standard and oil temperature conditioning. According to the test results, the oil breakdown voltage before heating (at room temperature) is 14 kV, which is much below the IEC 156 standard, and the breakdown voltage after heating at 90 ° is 35 kV, and 110 ° is 40 kV, which is even higher than the IEC 156 requirement

Indoor and outdoor concentrations of PM2.5 were measured for 24 h during heating and non-heating seasons in a rural solid fuel burning Native American community. Household building characteristics were collected during the initial home sampling visit using technician walkthrough questionnaires, and behavioral factors were collected through questionnaires by interviewers. To identify seasonal behavioral factors and household characteristics associated with indoor PM2.5 , data were analyzed separately by heating and non-heating seasons using multivariable regression. Concentrations of PM2.5 were significantly higher during the heating season (indoor: 36.2 μg/m3 ; outdoor: 22.1 μg/m3 ) compared with the non-heating season (indoor: 14.6 μg/m3 ; outdoor: 9.3 μg/m3 ). Heating season indoor PM2.5 was strongly associated with heating fuel type, housing type, indoor pests, use of a climate control unit, number of interior doors, and indoor relative humidity. During the non-heating season, different behavioral and household characteristics were associated with indoor PM2.5 concentrations (indoor smoking and/or burning incense, opening doors and windows, area of surrounding environment, building size and height, and outdoor PM2.5 ). Homes heated with coal and/or wood, or a combination of coal and/or wood with electricity and/or natural gas had elevated indoor PM2.5 concentrations that exceeded both the EPA ambient standard (35 μg/m3 ) and the WHO guideline (25 μg/m3 ).

As one of the three major vegetable oils in the world, rapeseed oil is appreciated for its high nutritional value and characteristic flavor. Flavor is an essential attribute, determining rapeseed oil quality and consumer acceptance. The present manuscript provides a systematic literature review of recent advances and knowledge on the flavor of rapeseed oil, which focuses on aroma-active as well as off-flavor compounds, flavor analysis techniques (i.e., extraction, qualitative, quantitative, sensory, and chemometric methods), and effects of treatments (storage, dehulling, roasting, microwave, flavoring with herbs, refining, and oil heating) on flavor from sensory and molecular perspectives. One hundred thirty-seven odorants found in rapeseed oil from literature are listed and possible formation pathways of some key aroma-active compounds are also proposed. Future flavor analysis techniques will evolve toward time-saving, portability, real-time monitoring, and visualization, which aims to obtain a "complete" flavor profile of rapeseed oil. The changes of volatile compounds in rapeseed oil under different treatments are summarized in this view. Studies to elucidate the influence of different treatments on the formation of aroma-active compounds are needed to get a deeper understanding of factors leading to the variations of rapeseed oil flavor.

Thyme oil, which is an anti-fungicide, was used to increase the physical and mechanical properties of wood as well as improve its strength, especially in outdoor conditions. For this purpose, Stone pine (Pinus pinea L.) wood samples classified according to the annual number of rings were exposed to either the impregnation process or the combined process, which was comprised of impregnation followed by heat treatment. As a result of the study, it was determined that the wood had different physical and mechanical properties based upon the number of annual rings. In addition, it was specified that the thyme oil used in the impregnation process improved the physical properties of the wood and also reduced the water absorption during the combined process. As a general conclusion, the impregnation process and the combined process increased the mechanical properties of the wood in parallel with an increase in the number of annual rings. The process of impregnation of wood materials with thyme oil is promising due to its anti-fungal and antibacterial properties, its ability to be used in small amounts in on-site impregnation, and it being an environmentally friendly product for the wood protection industry.

Using high frequency data and connectedness measures based on a time-varying parameter vector autoregression (TVP-VAR) model, we study dynamic connectedness among the realized volatility of 15 commodity futures (Gold, Heating oil, Light crude oil, Natural gas, Copper, Platinum, Cocoa, Coffee, Corn, Cotton, Orange Juice, Soybean, Soybean meal, Sugar, and Wheat) from September 22, 2008 to May 28, 2020. The results show strong and moderate levels of volatility connectedness among energy and metals and moderate connectedness levels within the group of agricultural commodities. Cross-commodity connectedness can explain a large portion of volatility connectedness in some cases, highlighting the importance of conducting realized volatility connectedness within a model allowing realized volatilities to be endogenously and simultaneously determined. Connectedness is robust to alternative specifications and varies with time. It is mostly driven by macroeconomic variables and uncertainty, including the term spread of interest rates and real economic activity. However, the analysis shows that some of the drivers of connectedness differ between upper and lower quantiles.

According to the US Department of Energy, succinic acid (SA) is a top platform chemical that can be produced from biomass. Bread waste, which has high starch content, is the second most wasted food in the UK and can serve as a potential low cost feedstock for the production of SA. This work evaluates the environmental performance of a proposed biorefinery concept for SA production by fermentation of waste bread using a cradle-to-factory gate life cycle assessment approach. The performance was assessed in terms of greenhouse gas (GHG) emissions and non-renewable energy use (NREU). Waste bread fermentation demonstrated a better environmental profile compared to the fossil-based system, however, GHG emissions were about 50% higher as compared to processes using other biomass feedstocks such as corn wet mill or sorghum grains. NREU for fermentative SA production using waste bread was significantly lower (~ 46%) than fossil-based system and about the same as that of established biomass-based processes, thus proving the great potential of waste bread as a valuable feedstock for bioproduction of useful chemicals. The results show that steam and heating oil used in the process were the biggest contributors to the NREU and GHG emissions. Sensitivity analyses highlighted the importance of the solid biomass waste generated in the process which can potentially be used as fish feed. The LCA analysis can be used for targeted optimization of SA production from bread waste, thereby enabling the utilization of an otherwise waste stream and leading to the establishment of a circular economy.

At present, steam-assisted gravity drainage technology has failed to meet the requirement for the large-scale development of abundant oil sands resources due to high production cost and serious environmental pollution caused by huge amounts of carbon emissions. Therefore, this paper proposes a radio frequency technology for heating oil sands and establishes a corresponding mathematical model that considers the phase transition of water. Then, a lab-scale experimental setup is designed to experimentally investigate the performance of radio frequency heating based on the phase change. Finally, the influences of phase transition of water on the temperature distribution of oil sand samples are analyzed in detail. The results show that the mathematical model of radio frequency heating can accurately predict the temperature distribution prior to the phase transition of water due to the little effect of phase transition on the thermal properties and density of oil sand samples. The failure to consider the effect of phase transition of water on electrical conductivity of oil sand in the mathematical model accounts for a large deviation between the measured temperature data and numerical results. So, in order to make the calculated temperature results more accurate, this effect should be considered during numerical simulation.

We develop an index of uncertainty, the COVID-19 induced uncertainty (CIU) index, and employ it to empirically examine the vulnerability of energy prices amidst the COVID-19 pandemic using a distributed lag model that jointly accounts for conditional heteroscedasticity, autocorrelation, persistence, and structural breaks, as well as day-of-the-week effect. The nexus between energy returns and uncertainty index is analyzed, using daily price returns of eight energy sources (Brent oil, diesel, gasoline, heating oil, kerosene, natural gas, propane, and WTI oil) and four news/information-based uncertainty proxies [CIU, EPU, Global Fear Index (GFI) and VIX]. The CIU and alternative indexes are used, respectively for the main estimation and sensitivity analysis. We show the outperformance of CIU over alternative news uncertainty proxies in the prediction of energy prices. News (aggregate) and bad news are found to negatively and significantly impact energy returns, while good news has a significantly positive impact. Imperatively, energy variables lack hedging potentials against the uncertainty occasioned by the COVID-19 pandemic, while we find no strong evidence of asymmetry. Our results are robust to the choice of news variables, forecast horizons employed, with likely sensitivity to energy prices.

Background Household air pollution (HAP) from residential combustion considerably affects human health in rural China. Large-scale population migration and rural lifestyle changes during the Spring Festival are supposed to change the household air pollution and health risks; however, limited field study has determined its impacts on HAP and short-term health outcomes. Methods A field study was conducted in rural areas of Southern China before and during the Spring Festival to explore the associations between HAP and blood pressure considering different factors such as cooking fuel, heating fuel, and smoking. Stationary real-time PM2.5 monitors were used to measure PM2.5 concentrations of the kitchen, living room, and yard of 156 randomly selected households. Personal exposure to PM2.5 was calculated based on the results of stationary samplers and corresponding time local residents spent in different microenvironments, and one adult resident was recruited of each family for the blood pressure measurement. Results Both personal exposure to PM2.5 and blood pressures of local residents increased during Spring Festival compared to the days before the holiday. Based on generalized linear model coupled with dominance analysis approach, it was found that personal PM2.5 exposure was positively associated with the factors of population size and the types of cooking and heating fuels with the relative contributions of approximately 82%, and systolic blood pressure (SBP, 100-120 mmHg as normal range for adults) was positively and significantly associated with personal PM2.5 exposures with the relative contribution of 11%. Conclusion The findings in this study demonstrated that Spring Festival can give rise to increase of HAP and hypertension risks, also related to tremendous solid fuel use, suggesting further policy making on promoting cleaner energy in rural areas and more attention on large population migration during national holidays.

The application progress of oil shale retorting process at home and abroad is mainly introduced, and the advantages and disadvantages of dry distillation furnaces in different countries are compared. The development trend of oil shale retorting process is prospected. At present, several oil shale retorting technologies have been applied and newly appeared in Fushun furnace retorting, fluidized bed retorting and decarbonization processes, convection heating oil shale mining processes, ATP dry distillation furnaces, ICP retorting furnaces, etc. Very mature, but the oil recovery rate using these technologies is relatively low. The industrialized dry distillation technology currently being put into production at home and abroad has been discussed, and the problems in the dry distillation technology have been studied.

This article provides an overview of the methods of managing the primary petroleum refining. To improve separation efficiency was proposed to stabilize the reflux ratio in the rectifying column. Purpose of work. To develop a system for automatic regulation of the reflux ratio of diesel fuel sec-tions in an atmospheric column of the refinery oil. To study the operating modes of an atmospheric column with the participation of the obtained automatic control system. Materials and methods. The article presented the features of the oil rectification process at the atmospheric unit of a small capacity refinery. The features of heat dissipation with intermediate circulation flash compared to a large-capacity unit will be shown in this article. The parameters of the facility were selected and divided into groups. A dynamic model of the section of shell-and-tube heat exchangers for heating oil with diesel fuel at a low-power refinery unit in the form of differential equations of heat balance has been developed to achieve the goal set work. An electrode dehydrator material balance equation has been compiled to find desalted oil consumption and saltwater consumption. The dependence of the reflux ratio of diesel fuel sections of the atmospheric column on the inlet and outlet temperatures of the atmospheric column circulation flash, the acute fractionation con-sumption, circulation flash, and oil fraction selection was obtained. The resulting model of the facili-ty consists of two parts: the linear part of the electric dehydrator and heat exchanger section, which determines the temperatures of the coolants, and the nonlinear output part, which determines the re-flux ratio depending on technological parameters. The proposed model makes it possible to investi-gate the effect of disturbances on the controlled parameters. The MATLAB/Simulink software prod-uct has been chosen as a tool to implement the model. A system of automatic regulation of the re-flux ratio in MATLAB/Simulink has been built with the participation of the developed model of the study object. Conclusion. The results of modeling a system for automatic regulation of the reflux ratio of diesel fuel sections in the atmospheric column of a low-power refinery unit has been ob-tained, taking into account the peculiarities of the process under disturbance conditions.

The effects of hot-cold bio-oil treatment on properties of wood material from pine species are not known. The purpose of this study is to determine the effect of hot-cold bio-oil treatment on oil uptake, density and moisture content properties of Brutia pine wood. This study used castor oil (Ricinus communis L.), flaxseed oil (Oleum linii), mixtured oil (castor oil + flaxseed oil) and Brutian pine sapwood (Pinus brutia Ten.). The wood samples were treated with hot oil (110 ºC ± 2 ºC) for 6 hours before cold oil (23 ºC ± 2 ºC) for 2 hours. Then, the oil uptake, density and moisture content of treated and untreated wood samples were measured. The data were analyzed by SPSS statistical program (p0.05). The results showed that hot-cold bio-oil treatment had a significant effect on oil uptake, density and moisture content of Brutia pine wood; and there were significant differences among these effects at 95% confidence level. Such treatment increased the treated wood density between 40.38% - 78.85% compared to untreated wood, while it reduced the moisture content between 93.44% - 96.72%. It was measured the highest density in linseed oil treatment, and the lowest density in castor oil treatment. Flaxseed oil treatment gave the lowest moisture content, while the highest moisture content was measured in mixed oil treatment. Mixed oil treatment increased the moisture content compared to others; increased the density compared to castor oil; reduced compared to flaxseed oil. Accordingly, the moisture diffusion may have been prevented. Because the porosity and penetration in Brutia wood have been limited with reduced the moisture content and increased the density., Sıcak-soğuk biyo-yağ işleminin yerli çam türü ağaç malzemenin özellikleri üzerine etkileri bilinmemektedir. Bu çalışmada sıcak-soğuk biyo-yağ işleminin kızılçam odunundan hazırlanan ağaç malzemede yağ alımı, yoğunluk ve rutubet miktarı üzerine etkisinin belirlenmesi amaçlanmıştır. Çalışmada, hint yağı (Ricinus communis L.), keten yağı (Oleum linii), karma yağ (hint yağı + keten yağı) ve kızılçam (Pinus brutia Ten.) diri odunu kullanılmıştır. Odun örnekleri 6 saat sıcak (110 ºC ± 2 ºC) yağ ile muamele edildikten sonra 2 saat soğuk (23 ºC ± 2 ºC) yağ ile muamele edilmiştir. Test ve kontrol örneklerinin yağ alımı, yoğunluk ve rutubet miktarları ölçülmüştür. Elde edilen veriler, SPPS istatistik programı yardımıyla analiz edilmiştir. Sonuçlar, sıcak-soğuk biyo-yağ işleminin kızılçam odununda yağ alımı, yoğunluk ve rutubet miktarını istatistiksel anlamda önemli derecede etkilediğini, bu etkiler arasında %95 güvenle önemli farklılıklar olduğunu göstermiştir. Bu uygulama ile test örneklerinin kontrole kıyasla yoğunluğu %40.38-%78.85 artarken, rutubet miktarı %93.44-%96.72 oranında azalmıştır. En yüksek yoğunluk keten yağı işleminde, en düşük yoğunluk ise hint yağı işleminde ölçülmüştür. Keten yağı muamelesi en düşük rutubet miktarını verirken en büyük rutubet miktarı karma yağ muamelesinde ölçülmüştür. Sıcak-soğuk karma yağ işlemi, diğerlerine göre rutubet miktarını yükseltirken, yoğunluğu hint yağına göre arttırmış, keten yağına göre azaltmıştır. Buna göre, denge rutubeti azalıp yoğunluğu artan kızılçam diri odununda porozite ve penetrasyon sınırlandığından rutubet difüzyonu engellenmiştir.

Background The health hazards of indoor air pollution are well-established but studies of the health effects due to pollution from heating are rare. This study investigated the association of heating and disability for activities of daily living among Chinese middle-aged and elderly. Methods We used two consecutive surveys in a cohort of over 17,000 adults aged 45 or older, who were interviewed first in 2011–2012 and then in 2013. In these surveys, taking advantage of random survey time, we applied a random effects logit regression model that included an interaction between pollution-producing heating fuel and a dummy variable, which measured interview time based on whether or not it was heating season. Results Exposure to pollution-producing heating fuel was associated with a 39.9% (OR 1.399; 95%CI 1.227–1.594) and 71.0% (OR 1.710; 95%CI 1.523–1.920) increase in the likelihood of disability in activities of daily living (DADL) and disability in instrumental activities of daily living (DIADL), respectively. In heating season between year 2011 and 2013, moving from clean heating energy for heating to pollution-producing fuel was linked with an increase in the likelihoods having DADL and DIADL, with the OR of 2.014 (95%CI 1.126–3.600) and 1.956 (95%CI 1.186–3.226), respectively. However, disability increases due to change from clean energy to pollution-producing heating energy did not appear in advantaged education respondents. Conclusions We found that exposure to heating by burning of coal, wood, or crop residue was associated with disability in performing daily living activities. Health policymakers should take indoor pollution due to heating into consideration as it is a major determinant of activities of daily living in elderly people; especially, such policy should focus on elderly people who have disadvantaged education.

In moderate climate, broiler chicken houses are important heating energy consumers and hence heating fuel consumption accounts for a large part in operating costs. They can be reduced by constructional measures, which in turn lead to important costs as well. On the other hand, a software solution to reduce energy would lead to considerably less follow-up costs. The main objective of our work was to assess if it is possible to save energy with a software solution and eventually quantify the savings for a given broiler house in the Swiss Plateau. The investigation was carried out in simulation: the particular broiler house was measured, and a dynamical model for it was derived and validated. To actually search for a particular behaviour of the software that would lead to energy savings, model predictive control was used. The idea was not to specify a particular behaviour of the software but rather to let the software itself find the best behaviour in an exhaustive search. The simulations showed that energy savings can be realised mainly by letting the indoor humidity deviate from what usually is used as setpoint and hence take profit of the outdoor climate, which changes naturally during a 24-hour course. We used expert opinions to determine how long and large these setpoint deviations may be without harming the broilers. The simulations showed alsothat the light control and the biological activity of the animals reduced the potential savings.

Significance This study uses data on ∼93 million individual homes to perform the most comprehensive study of greenhouse gases from residential energy use in the United States. We provide nationwide rankings of carbon intensity of homes in states and ZIP codes and offer correlations between affluence, floor space, and emissions. Scenarios demonstrate this sector cannot achieve the Paris Agreement 2050 target by decarbonizing electricity production alone. Meeting this target will also necessitate a broad portfolio of zero emission energy solutions and behavioral change associated with housing preferences. To support policy, we estimate the reductions in floor space and increases in density needed to build low-carbon communities., Residential energy use accounts for roughly 20% of greenhouse gas (GHG) emissions in the United States. Using data on 93 million individual households, we estimate these GHGs across the contiguous United States and clarify the respective influence of climate, affluence, energy infrastructure, urban form, and building attributes (age, housing type, heating fuel) in driving these emissions. A ranking by state reveals that GHGs (per unit floor space) are lowest in Western US states and highest in Central states. Wealthier Americans have per capita footprints ∼25% higher than those of lower-income residents, primarily due to larger homes. In especially affluent suburbs, these emissions can be 15 times higher than nearby neighborhoods. If the electrical grid is decarbonized, then the residential housing sector can meet the 28% emission reduction target for 2025 under the Paris Agreement. However, grid decarbonization will be insufficient to meet the 80% emissions reduction target for 2050 due to a growing housing stock and continued use of fossil fuels (natural gas, propane, and fuel oil) in homes. Meeting this target will also require deep energy retrofits and transitioning to distributed low-carbon energy sources, as well as reducing per capita floor space and zoning denser settlement patterns.

Purpose This paper aims to examine dynamic equicorrelations (DECO) and directional volatility spillover effects among four energy futures markets, namely, West Texas Intermediate crude oil, heating oil, natural gas and reformulated blendstock for oxygenate blending gasoline, by using a multivariate fractionally integrated asymmetric power ARCH–DECO–generalized autoregressive conditional heteroskedasticity (GARCH) model and the spillover index technique. Design/methodology/approach The empirical analysis uses the dynamic equicorrelation model of Engle and Kelly (2012) to examine time-varying correlations at equilibrium. The authors further analyze dynamic volatility transmission among energy futures by using Diebold and Yilmaz (2012) dynamic spillover index based on generalized value-at-risk framework. Findings The empirical results provide evidence of heightened equicorrelations at times of financial turmoil. More specifically, the dynamic spillover analysis shows that volatility is transmitted predominantly from crude oil to the other markets and risk transfer among four markets exhibits asymmetries. Spillovers are found to be highly responsive to dramatic events such as the 9/11 terror attack, 2008–2009 global financial crisis and 2014–2016 oil glut. Practical implications The results of this study have important practical implications for investors, portfolio managers and energy policymakers as the presence of time-varying co-movements and spillovers suggests the need for dynamic trading strategies. There are also implications regarding risk management practices, as there is evidence of increased volatility transmission at times of financial turmoil and uncertainty. Finally, the results provide insights to policymakers in a better understanding of the spillover dynamics. Originality/value This paper investigates the DECOs and spillover effects among crude oil, natural gas, heating oil and gasoline futures markets. To the best of the knowledge, this is one of a few studies that examine co-movements and risk transfer in energy futures in a comprehensive framework.

Oil heating has been degraded by thermal, air and moisture penetration leading to the creation of volatile and non-volatile materials serving as active substrate and increasing temperature and mass transmission levels. In this study, Fresh mustard oil was characterized to assess chemical properties like saponification value (SV), iodine value (IV), peroxide value (PV), p-Anisidine value (p-AV), Totox value (TV), acid value (AV),density and viscosity. The oil was reused (thermal process) for three sets of periods at different heat levels 120, 140, 160, 180 and 200 degrees the impact of the thermal process was examined through physicochemical, nutritional and sensory properties and compared with fresh mustard oil. Chemical compounds were identified for selected oils using GC-MS and FT-IR spectroscopy. The effect of spectra reveals there was a significant change in the thermal refined oils band (180 to 200 ° C) and higher temperature changes the band's exact positions and shifts when the fatty acid ratio has shifted. Similarly, the FT-IR study also found the drastic changes in the functional compounds at 180 to 200°C. The chemical property shows that primary and secondary level of rancidity were confirmed through peroxide value and p-Anisidine value respectively; the consistency and the flow rate was reduced due to the deterioration through rancidity.

An assessment of trends in main air pollutant concentrations (including CO, SO2, NO2, O3, PM2.5, and Asbestos) is conducted for the years 2005–2016 for the city of Tehran, Iran. The focus has been on the contribution of anthropogenic emissions to the observed trend, particularly the role of related mitigation plans implemented in the period of interest. A significant decreasing trend (about 50%) was observed in CO and SO2 concentrations during the considered time interval, which was explained by improvement plans in fuel quality and vehicle emission standards. While a substantial elevation (more than 50%) in NO2 levels was detected over the study period, variant trends were observed during different periods that appear to be driven by multiple factors including the increase in the number of vehicles and fuel consumption, changes in residential heating fuel from heavy oil to natural gas, etc. The analysis revealed that the O3 formation in Tehran's atmosphere was converted from NOx-limited to NOx-saturated regime around the years 2012–2013. The overall analysis showed a slight decreasing trend (about 30%) in PM2.5 concentrations between the years 2011–2015; however, a rise in PM2.5 levels was observed between the years 2015–2016. Apart from the contribution of anthropogenic drivers, general drought in Iran has caused a considerable increase in natural dust in total PM2.5 mass. Finally, a decline in annual mean airborne asbestos fibers (more than 60%) was indicated by the current study during the years 2012 and 2015.

Household heating in China has been ignored in the formulation of national energy plans until concerns with severe air pollution emerged. The government has started to implement the clean heating with ambitious targets. However, the specific heating status is not clear, especially in rural areas, thus leading to significant obstacles to policy formulation and air pollution control. In order to understand the current heating conditions and heating behaviors of households in more detail, we conduct a field survey of household heating in towns and villages across northern China from December 2017 to March 2018. The survey results show that more than 75% of rural households still rely on traditional heating methods, such as coal, firewood, kang, and a simple stove. Household income, awareness of using heating fuels, and government subsidies may have a certain impact on heating fuel choice. In addition, approximately 34.6% of rural households do not use any housing insulation measures, which is also of concern when focusing on the heating quality. Lastly, considering the huge cost of rural household clean energy transition, we suggest that only a few regions are encouraged to turn to electricity or natural gas for heating, while most other regions transition to using clean coal and attach more importance to improving the quality of heating stoves.

Purpose This paper aims to investigate the contemporaneous link between price volatility and trading volume in the futures markets of energy. Design/methodology/approach Non-parametric (local linear) regression models and formal statistical tests are used to assess monotonicity, linearity and symmetry. The data are daily price and volumes from five futures markets (West Texas Intermediate, Brent, gasoline, heating oil and natural gas) in the USA. Findings Trading volume and price volatility have, in all markets, a strong nonlinear relation to each other. There are violations of monotonicity locally but not globally. The qualitative nature of the price shocks may have implications for the trading activity locally. Originality/value To the authors’ best knowledge, this is the first manuscript that investigates simultaneously and formally all the three important issues (i.e. monotonicity, linearity and asymmetry) for the price volatility–volume relationship using a highly flexible nonparametric approach.

Highly viscous fuels present combustion challenges due to poor atomization and consequent inefficient air-fuel mixture, however, due to the demand for cheap heating fuels; burner design and fuel properties are continually optimized to enhance their combustion and emission performance. In this study, used engine oil was drained from the sump of a compression ignition engine; the oil was pre-treated to remove particulate matter, water and ferromagnetic materials. The oil samples were then blended with diesel fuel at different volumetric proportions and were characterized according to ASTM standard. The fuel samples were then combusted using atomizing swirl waste oil burner; flame temperature and flame size were measured using infrared thermometer and direct photography respectively. The burner was then mounted to a combustion chamber and the emission gases and flue gas temperatures were measured using a flue gas analyser and digital thermometer respectively. It was revealed that increasing diesel fuel blend decreases the density and viscosity of the fuel samples. All the blended fuel samples were found to form a homogenous mixture and generated flame temperature higher than the unblended oil sample (B0), B20 generated the highest flame temperature of 1400 °C with flame size of 340 × 210 mm and the lowest carbon monoxide (CO) emission of 0.49 %, unburned hydrocarbon (HC) of 249 ppm and the highest carbon dioxide (CO2) of 12.87 % levels. In view of this, diesel fuel can be used as a good blending candidate to used engine oil to improve flame temperature and decrease emission levels in swirl waste oil burners.

The effect of heavy stock oil heating by ultra-high frequency (microwave) electromagnetic field on oil viscosity changes is investigated in the present work. The influence of the phase state of supramolecular formations on the rheological properties of heavy oil after the application of various dielectric heating schemes is studied. The energy of the intermolecular interaction of asphaltene nanoaggregates of various sizes is estimated based on rheometric studies of heavy oil treated with microwave energy. It has been established that for a stable asphaltene oil, the hybrid microwave processing scheme is most effective.

We consider directional volatility connectedness among energy markets and financial markets over time and frequencies simultaneously during the period 2007–2018. We utilize and expand Barunik and Krehlik (J Financ Econom 16:271-296, 2018) connectedness measurements using HVAR in order to achieve a better perspective of energy markets. Our results indicate that during a crisis, the connectedness among markets increases dramatically. Furthermore, our findings support that markets are mostly driven by short-term factors and are highly speculative. Among energy markets, Natural Gas Futures contribute the least to other markets in all time frames. Besides, London Gas Oil Futures and Heating Oil Futures collaborate. Currencies and Natural Gas Futures are suitable choices for portfolio managers to hedge their risks especially in the long run. The findings of this article can offer new insights to policymakers about the mechanism of connectedness among different markets and international investors.

Recent studies have shown that heating oil to high temperature causes oxidative degradation of the oil, consequently producing characteristics odour, taste, colour and texture. However, this study was conducted to evaluate the stability of four different samples of edible oils. Acid value was found to be 5.22, 3.50, 0.73 and 1.29 mg KOH/g oil in fresh Melon, Bushmango, olive and Palm olein oils samples respectively. When the four oil samples were used for frying, the acid value was found to be; 6.73, 3.90, 2.24 and 2.24 mg KOH/g oil (24 hours after frying), 11.22, 7.86, 4.49 and 3.3 mg KOH/g oil (2 weeks after frying) and 19.17, 13.22, 5.82 and 4.4 mg KOH/g oil (4 weeks after frying), for melon, Bushmango, olive and palm olein oils samples respectively. Saponification values were ranged between 196.70-240.00 mg KOH/g oil in fresh oils of the samples, and between 197.80-252.33 mg KOH/g oil in the oils after using them for frying. Furthermore, Peroxide values ranged from 2.65 to 3.20 Meq/Kg in fresh oils of the samples, and from 2.71 to 24.00 Meq/Kg in frying oils were to exceed the permitted value of 20 meq/Kg for olive oil and 10 meq/Kg for other edible oils in nearly half the analyzed samples. In general, feeding on these kinds of edible oils which have high values of acidity and peroxides is very dangerous because of the destructive effects of peroxide compounds and acidity on the components of the membranes of the living cell.

In a gas turbine power plant, the lubrication oil must be hot enough for the turbine start-up where the unit is in standstill mode. Currently, the strategy to heat the lubrication oil of ANSALDO V94.2 gas turbine power plant is operating the units in turning gear mode or interval mode. However, these strategies cause to suffering the power plant from high power consumption rate and aging. In this study, an auxiliary portable heating system was added to the unit 5 of the MAPNA built MGT-70 (an Iranian version of V94.2) Aliabad Katoul-Iran power plant for increasing the lube oil temperature. Irreversibility, cost-effectiveness, and availability of the proposed heating system are studied by the concepts of exergy, economy, and reliability analyses, respectively. The result of the exergy analysis shows that by using the auxiliary portable lube oil heating system the exergy destruction decreases about 94.7% and 92.6% in comparison with turning gear mode and interval mode, respectively. The result of the economic analysis shows that the auxiliary portable heating system consumes less power rather than turning gear mode. Moreover, it is a cost-effective system which has no penalty and no non-profit production. Finally, the reliability analysis shows that the auxiliary portable lube oil heating system is a reliable tool during its lifetime. Keywords: Gas turbine, Lube oil, Lubrication system, Portable heater, Exergy, Reliability

The use of renewable energy sources increases the energy self-sustainability of cities, enabling citizens to reduce energy costs, which results in an increase in their standard of living. However, solar energy penetration in Bosnia and Herzegovina, and its capital Sarajevo, is not in line with the possibilities. Furthermore, the Sarajevo Canton is extremely polluted during the winter months because of the use of unacceptable heating fuel. The aim of this paper is to introduce photovoltaic power systems use in heating electrification system. In this paper AQI is calculated based on historical data and the hybrid model EMD-SARIMA for air pollution and a solar production forecast is presented. The methodology was tested in the Sarajevo Canton, taking into account 35,000 households. In order to ensure clean air, renewable electric energy use for household heating should be implemented. The widespread use of inefficient individual heating systems characterized by inefficient and expensive use of firewood and the use of coal in individual furnaces in populated areas are the main problems of internal and urban air pollution in Sarajevo Canton. In order to reduce energy poverty in Sarajevo Canton, the use of a floating photovoltaic power plant located on Lake Jablanica with a capacity of 30 MW and the solar prosumers with capacity of 115 MW to provide the 196 GWh necessary for heating electrification of 35,000 households is implemented in this paper. Finally, based on correlation between AQI forecast and solar production it was calculated that the values of the AQI, considering the application of solar energy during 150 days (five months) in one heating season, have significantly decreased. Also renewable energy sources have a very important role in reducing carbon dioxide (CO2) emissions into the atmosphere and reducing urban pollution. With this approach, households would be heated by renewable electricity, which would make Sarajevo a cleaner, smarter city.