Transportation carbon emission reduction has become an important driving point for China to achieve carbon peak and carbon neutrality. Based on the three-dimensional grey correlation analysis model, taking the five factors affecting transportation carbon emissions, namely, population, GDP, tertiary industry, energy structure and logistics scale, as the research object, the transportation carbon emissions of China’s low-carbon pilot and nonpilot provinces from 2010 to 2019 are calculated based on the Intergovernmental Panel on Climate Change (IPCC) carbon emission accounting method. The time series grey correlation degree and regional grey correlation degree of each influencing factor and traffic carbon emission are obtained using the provincial data, so as to provide policy suggestions for China to achieve the goal of “carbon peak and carbon neutrality” in the field of transportation. The results show that the descending order of the five influencing factors on transportation carbon em... [more]

The working life of a stack is basically determined by the behavior of its weakest monomer; therefore, during a dynamic loading process, high-voltage uniformity plays a key role in stack durability. This work experimentally investigated dynamic responses and voltage uniformity with different loading strategies from an initial state (open-circuit state) to a target current at subzero temperatures. The results presented that the maximum voltage coefficient variation Cv values, representing the relative standard deviation of the monomer voltage, increased from 19.75 to 35.65 and the voltage uniformity sharply decreased with the increase in loading sizes at the stack temperature of −4 °C. It was possible that this could result in the instability of the single cell voltage output and a voltage uniformity fluctuation with a high step loading amplitude. The voltage uniformity became worse as the stack temperature decreased from −2 °C to −8 °C, the voltage uniformity between single cells of th... [more]

Typically, reinforced concrete and brick masonry construction is the most common construction system of the majority of the southern European residential building stock. However, the lightweight steel framing (LSF) construction system has been progressively assuming a relevant position in the residential sector. Since LSF is not the traditional construction system, the indoor thermal environment of these buildings has not been widely studied and discussed considering the southern European climate context. The low thermal inertia of this construction system is commonly pointed to as a possible weakness in warmer climates. The present work aims to address this research gap by evaluating and comparing the LSF and masonry construction systems in terms of the indoor thermal environment focusing on the level of thermal inertia. The considered methodology lies in a long-term experimental campaign based on the construction and monitoring of two identical experimental test cells, differing only... [more]

Nanofluids as heat transfer fluids have been acquiring popularity ever since their beginning. Therefore, the refrigeration research could not keep itself away from the ever-rising horizon of nanofluid applications. On the other hand, nanofluid stability remains the critical bottleneck for use. A significant reduction in nanofluids’ performance can derivate from instability phenomena. Looking to industrial applications, nanofluid long-term stability and reusability are crucial requisites. Nanoparticles’ deposits induce microchannel circuit obstruction, limiting the proper functioning of the device and negating the beneficial characteristics of the nanofluid. The aggregation and sedimentation of the particles may also determine the increased viscosity and pumping cost, and reduced thermal properties. So, there is a need to address the features of nanofluid starting from realization, evaluation, stabilization methods, and operational aspects. In this review, investigations of nanorefriger... [more]

This contribution introduces a new hybrid enhanced oil recovery (EOR) method which combines smart water-assisted foam (SWAF) flooding, known as the SWAF process. The concept of applying SWAF flooding in carbonate reservoirs is a novel approach previously unexplored in the literature. The synergy effect of the SWAF technique has the potential to mitigate a number of limitations related to individual (i.e., conventional water injection and foam flooding) methods encountered in carbonates. In general, carbonate rocks are characterized by a mixed-wet to oil-wet wettability state, which contributes to poor oil recovery. Hence, the smart water solution has been designed to produce a dual-improvement effect of altering carbonate rock wettability towards more water-wet, which preconditions the reservoir and augments the stability of the foam lamellae, which has for some conditions more favorable relative permeability behavior. Then the smart water solution is combined with surfactant (surfacta... [more]

Although the conversion of lignocellulosic biomass into bio-oil with high yield/quality through hydrothermal liquefaction (HTL) is promising, it still faces many challenges. In this study, a Fex-Co(1-x)/Al2O3 catalyst was prepared with the coprecipitation method and low-content ethanol was used as the cosolvent for the HTL of poplar. The results showed that the Fex-Co(1-x)/Al2O3 catalyst significantly promoted the yield and energy recovery rate (ERR) of bio-oil compared with the control (10% ethanol content). At 260 °C for 30 min, 60Fe-40Co/Al2O3 had the best catalytic effect, achieving the highest bio-oil yield (67.35%) and ERR (93.07%). As a multifunctional bimetallic catalyst, Fex-Co(1-x)/Al2O3 could not only increase the degree of hydrogenation deoxidization of the product but also promote the diversity of phenolic compounds gained from lignin. The bio-oil obtained from HTL with Fex-Co(1-x)/Al2O3 as catalyst contained lower heterocyclic nitrogen, promoting the transfer of more bio-... [more]

Perovskites are a promising class of semiconductor materials, which are being studied intensively for their applications in emerging new flexible optoelectronic devices. In this paper, device manufacturing and characterization of quasi-interdigitated back-contact perovskite solar cells fabricated on flexible substrates are studied. The photovoltaic parameters of the prepared flexible quasi-interdigitated back-contact perovskite solar cells (FQIBC PSCs) are obtained for the front- and rear-side illumination options. The dependences of the device’s open-circuit potential and short-circuit current on the illumination intensity are investigated to determine the main recombination pathways in the devices. Spectral response analysis of the devices demonstrates that the optical transmission losses can be minimized when FQIBC PSCs are illuminated from the front-side. Optoelectronic simulations are used to rationalize the experimental results. It is determined that the obtained FQIBC PSCs have... [more]

Accurate wind power forecasting helps relieve the regulation pressure of a power system, which is of great significance to the power system’s operation. However, achieving satisfactory results in wind power forecasting is highly challenging due to the random volatility characteristics of wind power sequences. This study proposes a novel ultra-short-term wind power combined prediction method based on complementary ensemble empirical mode decomposition, the whale optimization algorithm (WOA), and the Elman neural network model. The model can not only solve the phenomenon of easy modal mixing in decomposition but also avoid the problems of reconstruction error and low efficiency in the decomposition process. Furthermore, a new metaheuristic algorithm, WOA, was introduced to optimize the model and improve the accuracy of wind power prediction. Considering a wind farm as an example, several wind turbines were selected to simulate and analyse wind power by using the established prediction mo... [more]

The purpose of the following article is to present the situation of the energy market from a household perspective between 2010 and 2020 in selected EU countries (the group of member states which joined EU after 2004). The selected countries when joining the EU had similar economic indicators and to some extent were similar in other macro-economic situations (personal income, unemployment rate, GDP level and annual growth). This article analyzes the past and current situation of the household ability expenditure on electricity and energy resources (petrol—eurosuper 95 and diesel and natural gas), taking into account price, tax conditions and the real possibility to purchase the analyzed energy sources (based on annual net salaries). The paper includes the conclusions and prospects for the future. The main objective of the study is to determine the ability amount of expenditure on electricity, natural gas and liquid fuels by household in the countries that joined the European Union afte... [more]

Energy-environmental planning for road transportation involves a vast investigation of vehicles’ technologies and electricity production. However, in developing countries where the public transportation sector is growing quickly, energy-environmental planning is urgently needed. This paper evaluates the future electricity demand, as well as fuel consumption and CO2 emissions reduction, due to the operation of an expected increasing number of electric vehicles (EVs) in Pakistan. The planning of EVs up to 2040 is performed with the ePop simulator that calculates the future EVs’ electricity demand, while EnergyPLAN® assesses the expected new power capacities. Two scenarios are investigated by penetrating 30% and 90% of 2/3 electric wheelers and cars by 2030 and 2040 compared to 2020, respectively. To fulfill the expected energy demand, PV in the daytime and the national electric grid at nighttime are here considered. Finally, a 9 GW of PV capacity is needed to satisfy the EVs’ electricity... [more]

Temporally and spatially resolved laser-induced breakdown spectroscopy (LIBS) was applied to a four-stroke, single-cylinder test engine’s cyclic exhaust gas to demonstrate engine performance. The LIBS technique provided quantitative air-to-fuel ratio (A/F) measurements by generating localized breakdown plasma during the compression and exhaust strokes. The results showed that the timing and duration settings of the emission energy ionization and molecular spectra affect the intensity peaks. Optimum measurements performed between 200 ns and 10 ms after breakdown resulted in observed atomic spectra of CI (248 nm), Hβ (485 nm), Hα (656 nm), NI (745, 824 nm), and OI (777, 844 nm). The intensities of CI (248 nm) and Hα (656 nm) decreased with increasing A/F, whereas the intensity ratios of NI and OI remained constant. A decrease in the intensity ratio of C/O and Hα/O was observed as the A/F increased. This study is a major step toward defining a means of using LIBS to control the A/F ratio... [more]

The United Nations Framework Convention on Climate Change Paris Agreement has been announced as a crucial step towards combating the global threat of climate change. In the light of ambitious plans for further renewable energy sources development, high demand for nonenergy materials critical for RES is greatly expected. In conclusion, future energy security will be surely based on nonenergy commodities critical for them. As this article directly relates to issues related to new technologies and energy security in new form, the main purpose of this study is to examine the impact of energy commodity prices, namely crude oil, natural gas and coal prices on selected metal prices such as aluminium, chromium, cobalt, copper, lead, nickel, silver, tin, or zinc, both before and over the Paris Agreement period. We are looking for new insights in terms of relationships between traditional fossil fuels and metals used in clean energy technologies potentially established or strengthened shortly af... [more]

The present work describes highly efficient hydrogen production from ethanol in a plasma-catalytic reactor depending on the discharge power and catalyst bed temperature. Hydrogen production increased as the power increased from 15 to 25 W. A further power increase to 35 W did not increase hydrogen production. The catalyst was already active at a temperature of 250 °C, and its activity increased with increasing temperature to 450 °C. The further temperature increase did not increase the activity of the cobalt catalyst. The most important advantage of using the catalyst was the increased ethanol conversion to CO2 instead of CO production. As a result, the hydrogen yield was very high and reached 4.1 mol(H2)/mol(C2H5OH). This result was obtained with a stoichiometric molar ratio of water to ethanol of 3.

Climate change, as well as the challenges that come with it, is one of the main issues in international and national politics today. Addressing the threats posed by climate change requires close cooperation at the international level and within each country, creating a dialogue between the political elite and society, thus promoting a common understanding and action across the European Union (EU). The aim of this research is to (1) identify what climate policy narratives are projected to the Latvian electorate (public) and (2) assess how these narratives are aligned with the EU-defined strategic climate policy narrative. The theoretical basis and methodological approach of the study is based on the concept of strategic narrative. It is assumed that the viability and impact of a strategic narrative is enhanced when there is coherence between all stages of the narrative life cycle (i.e., the EU level and the national policy level). The empirical basis of the study is based on the identif... [more]

The interpretation of subsurface fluid flow features in seismic reflection data is a key part of identifying the presence of hydrocarbon and active petroleum systems. Currently, this kind of study is mainly conducted utilizing offshore seismic reflection data with very limited cases utilizing onshore seismic reflection data. In addition, the Alamein basin is an area of prolific study in onshore Egypt, with most related studies concentrating on basin analysis and reservoir characterization. Therefore, in our study we aimed to make practical and effective use of onshore seismic reflection data with seismic attribute analysis to describe seismic facies, delineating and interpreting subsurface fluid flow features. The relatively vertical V-shaped and pipe or concave-up-shaped features with distorted reflections inside them are revealed through the analysis of variance, sweetness, chaos, instantaneous frequency and the RMS amplitude of seismic attributes. These subsurface fluid flow feature... [more]

The economic activity of businesses and the living standards of the population are largely dependent on inflation. Here, energy prices are of particular importance. Energy is what offers a competitive edge to economies. Therefore, many energy sectors still remain under state control. However, the fuel market is free although highly concentrated. The primary objective of this study was to determine the impact of fuel price changes on inflation in Poland. The research was based on causality models and regression models including asymmetry correction. The flow path was analyzed of price impulses from the basic raw material (i.e., crude oil) through wholesale diesel prices to inflation. The study demonstrates that with each successive stage of raw material processing, price volatility proves to be weaker. However, the final effect is still significant: inflation is largely shaped by energy carriers and, here, specifically by fuel prices. Such results have serious implications for the state... [more]

Blockchain technology is used as a distributed ledger to store and secure data and perform transactions between entities in smart grids. This paper proposes a platform based on blockchain technology and the multi-agent system paradigm to allow for the creation of an automated peer-to-peer electricity market in micro-grids. The use of a permissioned blockchain network has multiple benefits as it reduces transaction costs and enables micro-transactions. Moreover, an improvement in security is obtained, eliminating the single point of failure in the control and management of the platform along with creating the possibility to trace back the actions of the participants and a mechanism of identification. Furthermore, it provides the opportunity to create a decentralized and democratic energy market while complying with the current legislation and regulations on user privacy and data protection by incorporating Zero-Knowledge Proof protocols and ring signatures.

The interest in and need for carbon-free fuels that do not rely on fossil fuels are constantly growing from both environmental and energetic perspectives. Green hydrogen production is at the core of the transition away from conventional fuels. Along with popularly investigated pathways for hydrogen production, thermochemical water splitting using redox materials is an interesting option for utilizing thermal energy, as this approach makes use of temperature looping over the material to produce hydrogen from water. Herein, two-step thermochemical water splitting processes are discussed and the key aspects are analyzed using the most relevant information present in the literature. Redox materials and their compositions, which have been proven to be efficient for this reaction, are reported. Attention is focused on non-volatile redox oxides, as the quenching step required for volatile redox materials is unnecessary. Reactors that could be used to conduct the reduction and oxidation reacti... [more]

The high frequency PWM voltage pulses from a two-level six-switch inverter produce a common-mode voltage in an electric machine’s windings, a fraction of which appears on the machine shaft due to electrostatic (capacitive) coupling. When the shaft voltage exceeds the dielectric strength of the bearing lubricating grease, electric discharge machining (EDM) electrostatic discharges occur within the bearing, which can lead to premature failure. According to pulsed dielectric theory, the breakdown voltage across a dielectric increases with an increase in voltage slew rate (dv/dt). Therefore, the faster voltage rise times of wide bandgap devices are expected to produce higher magnitude shaft voltages and EDM bearing currents. This paper presents circuit modeling of EDM currents and compares the shaft voltage and bearing current amplitudes of silicon- and silicon carbide-based PWM inverters through experimental measurements and a statistical analysis using probability density functions. The... [more]

This article presents an approach to the diagnosis of the business area for new entities on the raw material market in Poland. In the face of the need for changes as a result of the assumptions of the Green Deal and the global transformation of production processes toward a sustainable approach and circular economy, a diagnosis was made of the area that can be explored by new entities in the raw material industry. After the diagnosis of this area, a PESTEL analysis was carried out, which may contribute to a better definition of business goals and the scope of activities for new entities on the market or those who want or need to change industries. PESTEL is an analysis aimed at assessing the macroeconomic environment of a company. It helps in making strategic decisions for the enterprise. The research results presented in this article are part of a project implemented as part of an international cooperation within the V4 countries. In each of them, there is a defined market of mineral... [more]

The paper shows the usage of destructive assay data from PWR fuel samples for the validation of the NFCSS burnup system developed by the IAEA. The results of radiochemical measurements of spent fuel isotopic composition were compared with the results of numerical modelling. In total, 254 samples from 15 PWRs, incorporated in the SFCOMPO database, were applied in the validation study. The paper shows the trends observed in the calculated-to-experimental ratios for eight major actinides and six minor actinides present in spent nuclear fuel. The data were quantified and analysed considering the enrichment, burnup and origin. The obtained results were compared with other studies on burnup validation using different numerical tools. In general, the results of numerical modelling for major actinides show rather good consistency with radiochemical measurements, while the results for minor actinides are less accurate.

Renewable energy sources and sustainability have been attracting increased focus and development worldwide. Qatar is no exception, as it has ambitious plans to deploy renewable energy sources on a mass scale. Qatar may also investigate initiating and permitting the deployment of rooftop photovoltaic (PV) systems for residential households. Therefore, a research gap has been introduced regarding the system design, grid compatibility, economic viability, and energy consumption produced from household rooftop PV systems. Additionally, the lack of supporting policies and a feed-in tariff creates further research and development topics. Therefore, using collected data regarding household power consumption and rooftop PV generation, the purposes of this research study are as follows: (1) determining the economic aspects and practicality of using energy storage systems for self-consumption values; and (2) evaluating the economic viability of rooftop PV systems under different policies and ele... [more]

Anaerobic digestion is one of the leading ways to manage livestock manure for energy production and move towards the target of carbon neutrality in the agricultural sector. Based on field survey data from China, a binary probit model and the propensity score matching method are employed to empirically examine the impact of agricultural training on livestock farmers’ installation of biogas digesters to manage livestock manure. The survey results show that beef cattle farmers in our study area are reluctant to install biogas digesters and the actual installation ratio of farmers is much lower than that that is willing to install. On the contrary, the beef cattle farmers are enthusiastic to participate in training (e.g., policy-oriented, technology-oriented, and field-based) related to sustainable farming practices. Regression results suggest that training can effectively promote the installation of biogas digesters, and with the increase of training intensity, the probability to install... [more]

Rate of penetration (ROP) prediction is critical for the optimization of drilling parameters and ROP improvement during drilling. However, it is still challenging to accurately predict ROP based on traditional empirical formula methods. This is usually the case for the development of the Wushi 17-2 oilfield block in the South China Sea. The Liushagang Formation is complex and the ROP is relatively low and difficult to increase. Ordinary data-driven ROP prediction models are not applicable because they do not take into account the complexity of formation conditions. In this work, we characterize the formation with acoustic transit time and build a data-driven ROP prediction model based on a deep neural network approach. By using the exploratory well data of the Wushi 17-2 oilfield for training and testing, the matching degree of the established model with the real data can reach 82%. In addition, we have developed a drilling parameter optimization process based on the ROP prediction mod... [more]

Islanding detection and prevention are involved in tandem with the rise of large- and small-scale distribution grids. To detect islanded buses, either the voltage or the frequency variation has been considered in the literature. A modified passive islanding detection strategy that coordinates the V-F (voltage−frequency) index was developed to reduce the non-detection zones (NDZs), and an islanding operation is proposed in this article. Voltage and frequency were measured at each bus to check the violation limits by implementing the proposed strategy. The power mismatch was alleviated in the identified islands by installing a battery and a diesel generator, which prevented islanding events. The proposed strategy was studied on the three distinct IEEE radial bus distribution systems, namely, 33-, 69-, and 118-bus systems. The results obtained in the above-mentioned IEEE bus systems were promising when the proposed strategy was implemented. The results of the proposed strategy were compar... [more]