Currently, in conditions of Industry 4.0, the use of cyber-physical systems in various fields is becoming widespread. This article is devoted to the problem of estimating CPS sustainability in the context of modern challenges faced by decision makers and IT developers in order to ensure effective proactive business process management using this innovative technology. The purpose of the research is to propose and substantiate a methodology for estimating CPS sustainability to ensure the reliability and strength of its elements, their interrelationships and interaction, as well as the effective functioning and development of this system in conditions of high dynamism and uncertainty of the external environment. In this study, we used methods of integral evaluation, synthesis, expert assessments, dynamic analysis, and systematic approach, and coined the term ‘CPS sustainability’. Our study showed that negative risks, external and internal threats may have a significant adverse impact on C... [more]

This study examines the concentrations of air pollution in the vicinity of a combined heat and power plant (CHP) and a communication route, using computer modeling of pollutant dispersion and spatial analysis based on real measurements in the city of Łódź, Poland, Europe. The research takes into account the concentrations of particulate matter (PM10, PM2.5, PM1.0) and gaseous pollutants (SO2 and VOC) in winter and summer. The spatial distribution of pollutants is discussed, including the presence of areas with increased accumulations of pollutants. Because atmospheric air has no natural boundaries, when analyzing any location, not only local sources of pollution, but also background pollution, should be analyzed. A clear difference was observed between the concentrations of pollutants in the summer and winter seasons, with significantly higher concentrations in the winter (heating) period. The impacts of road transport, individual heating systems, and combined heat and power plants wer... [more]

Taking a plateau high-pressure common-rail diesel engine as the research model, a model was established and simulated by AVL FIRE according to the structural parameters of a diesel engine. The combustion and emission characteristics of D, B20, and B50 diesel engines were simulated in the plateau atmospheric environment at 0 m, 1000 m, and 2000 m. The calculation results show that as the altitude increased, the peak in-cylinder pressure and the cumulative heat release of diesel decreased with different blending ratios. When the altitude increased by 1000 m, the cumulative heat release was reduced by about 5%. Furthermore, the emission trend of NO, soot, and CO was to first increase and then decrease. As the altitude increased, the mass fraction of NO emission decreased. As the altitude increased, the mass fractions of soot and CO increased. Additionally, when the altitude was 0 m and 1000 m, the maximum temperature, the mass fraction of OH, and the fuel−air ratio of B20 were higher and... [more]

Reservoir formation waters typically contain scaling ions which can precipitate and form mineral deposits. Such mineral deposition can be accelerated electrochemically, whereby the application of potential between two electrodes results in oxygen reduction and water electrolysis. Both processes change the local pH near the electrodes and affect the surface deposition of pH-sensitive minerals. In the context of the plugging and abandonment of wells, electrochemically enhanced deposition could offer a cost-effective alternative to the established methods that rely on setting cement plugs. In this paper, we tested the scale electro-deposition ability of six different formation waters from selected reservoirs along the Norwegian continental shelf using two experimental setups, one containing CO2 and one without CO2. As the electrochemical deposition of scaling minerals relies on local pH changes near the cathode, geochemical modelling was performed to predict oversaturation with respect to... [more]

Since the publication of the first comprehensive Probabilistic Safety Assessment (PSA) study—known as WASH-1400—in the US, PSA has developed into an effective and systematic method of identifying hazards, and evaluating and prioritizing the risks in nuclear facilities [...]

Ammonia combustion is a promising energy source as a carbon free fuel without greenhouse gas emissions. However, since the auto-ignition temperature is 651 degrees Celsius and the range of flammability limit is not wide compared to other fuels, fundamental studies on ammonia fires have rarely been conducted so far. Therefore, this study aims to numerically estimate fire spread characteristics when ammonia fuel in a high-pressure state leaks to the outside, especially focusing on the flammability limit according to oxygen concentration. Three kinds of reaction mechanism for numerical analysis were adopted to compare the flame structure, flammability limit, and combustion characteristics. Plank-mean absorption coefficients of nitrogen species were taken for the radiation model, in addition to the optically thin model. The effect of radiation heat loss could be identified from the maximum flame temperature trend at a low strain rate. It was confirmed that the pyrolysis of ammonia in the p... [more]

A synthetic review of the application of multi-objective optimization models to the design of climate-responsive buildings and neighbourhoods is carried out. The review focused on the software utilized during both simulation and optimization stages, as well as on the objective functions and the design variables. The hereby work aims at identifying knowledge gaps and future trends in the research field of automation in the design of buildings. Around 140 scientific journal articles, published between 2014 and 2021, were selected from Scopus and Web of Science databases. A three-step selection process was applied to refine the search terms and to discard works investigating mechanical, structural, and seismic topics. Meta-analysis of the results highlighted that multi-objective optimization models are widely exploited for (i) enhancing building’s energy efficiency, (ii) improving thermal and (iii) visual comfort, minimizing (iv) life-cycle costs, and (v) emissions. Reviewed workflows dem... [more]

Willows are one of the plants which can be used to produce biomass for energy purposes. Biomass production is classified as a renewable energy source. Increasing the share of renewable sources is one of the priority actions for European Union countries due to the need to reduce greenhouse gas emissions. To achieve the best possible growth of the willow and increase its biomass for fuel, it is crucial to provide optimal water conditions for its growth. The aim of the study was to determine the water requirements of willows under the conditions of the western Polish climate and to verify whether this area is potentially favourable for willow cultivation. The novelty of this paper lies in its multi-year climatic analysis in the context of willow water needs for the area of three voivodships: Lubusz, Lower Silesian, and West Pomeranian. This is one of the few willow water-needs analyses for this region which considers the potential for widespread willow cultivation and biomass production i... [more]

This paper focuses on a detailed numerical investigation combined with experimental research for a non-premixed swirl combustor, which aims to analyze the effects of the blade angle of the outer swirler and equivalence ratio on flow and combustion characteristics. In the experiment, the temperature in the furnace was obtained with a thermocouple, while a realizable k-ε turbulence model and two-step reaction mechanism of methane and air are used in the numerical method. The calculation results are in good agreement with the experimental data. The results reveal that the air flow rate through the swirler accounts for a small amount of the total air due to the influence of the draft fan, and there is no central recirculation zone (CRZ) despite the presence of the swirler. It was also found that NO emissions gradually decrease as the blade angle of the outer swirler increases. It was also indicated that the average temperature is 100 K higher than the general combustor with a 58° blade ang... [more]

In order to achieve Australia’s greenhouse gas emissions reduction targets, a majority of the existing residential building stock in Australia will require retrofitting in favour of energy-efficient solutions. This paper considers retrofitting for conditioning to be one of the most straightforward and offers the greatest potential to deliver significant comfort and energy-saving results. Radiant conditioning systems are not new, yet some game-changing innovations have taken place over the last decade that may require an entire paradigm shift in the manner we condition our buildings. The reiteration of the principle ‘thermally active systems’ suggests that our buildings need to accommodate these systems into the fabric of building components. However, extremely few products and/or innovative solutions for doing such seem to be provided by the industry. We seem incompetent with solutions that are not costing the Earth, insulating, lightweight, and offering an instant response time to con... [more]

Climate change and environmental pollution are considered to be among the main challenges faced by the modern world. The growth of environmental awareness and the adoption of a pro-environmental approach are considered to be the key megatrends with the greatest impact on the global economy in the upcoming years. According to Eurobarometer, EU citizens are particularly aware of the importance of protecting the environment. Although the negative environmental impact of European industry has improved over the past decades, EU citizens believe that there is further scope in terms of helping companies transition towards adopting more sustainable models. One of the factors contributing to the reduction in negative environmental impact is the participation of enterprises in voluntary programs such as the Environmental Management System (EMS), according to ISO 14001, or the Eco-management and Audit Scheme (EMAS). The whole population of Polish companies registered under the EMAS was included i... [more]

The performance of the air-cooler in refrigeration systems plays a key role in their energy efficiency. Here, the plenum-chamber coefficient was defined to investigate a possible way of enhancing the refrigeration coefficient that reflects the efficiency of the system. To investigate the influence of the plenum-chamber coefficient on the frosting and the cooling system of the air-cooler, three plenum-chamber coefficients (0.74, 0.97, 1.2) were studied under two different relative humidities. The temperature decreasing curve of the environmental chamber, the velocity distribution of the air-cooler, and the frost accumulation under and on the air-cooler were analyzed. We find that the homogeneity of the velocity distribution of the air-cooler and the frost accumulation increase with a growing plenum-chamber coefficient, while the frost accumulation on the fin will first increase and then decrease with the increase in the plenum-chamber coefficient. In general, frosting is more present wh... [more]

Solid circulation rate (Gs) represents the mass flux of circulating particles in circulating fluidized bed (CFB) systems and is a significant parameter for the design and operation of CFB reactors. Many measuring technologies for Gs have been proposed, though few of them can be applied in industrial units. This paper presents a comprehensive study on measuring technologies, and the results indicate that though the accumulation method is most widely applied, it is constrained by the disturbance of normal particle circulation. Some publications have proposed mathematic models based on pressure drop or other parameters to establish Gs measurement models; these necessitate the accurate modeling of complicated gas-solid flows in industrial devices. Methods based on certain measurement devices to specify parameters like velocity require device endurance in the industrial operation environment and stable local gas-solid flow. The Gs measuring technologies are strongly influenced by local gas-... [more]

The aim of the study is to draw attention to the fact that reducing methane and nitrous oxide emissions as a result of traditional manure storage for several months in a pile is not only a non-ecological solution, but also unprofitable. A solution that combines both aspects—environmental and financial—is the use of manure as a substrate for a biogas plant, but immediately—directly after its removal from the dairy barn. As part of the case study, the energy and economic balance of a model farm with dairy farming for the scenario without biogas plant and with a biogas plant using manure as the main substrate in methane fermentation processes was also performed. Research data on the average emission of ammonia and nitrous oxide from 1 Mg of stored manure as well as the results of laboratory tests on the yield of biogas from dairy cows manure were obtained on the basis of samples taken from the farm being a case study. The use of a biogas installation would allow the emission of carbon dio... [more]

Because of rapid urbanization, traffic problems, and other factors, underground spaces have been used more in the twenty-first century. Large underground spaces are required for underground city, metro, tunnel, mine, industrial and agricultural engineering, and civil air defense engineering. Underground spaces with varying thermal, ventilation, and lighting environments can face problems of comfort, health, and safety. High temperatures, high humidity, difficulty in flue gas emission, harmful microorganisms, radon, and physical and psychological problems are examples of issues. Air quality control technologies for underground spaces, such as ventilation, dehumidification, natural energy utilization, smoke extraction, and ventilation resistance reduction, are discussed. Ventilation for smoke-proofing/evacuation is also extensively addressed.

European Union Member States are called upon to meet internationally proposed environmental goals. This study is based, in particular, on the recommendation of the European Union (EU), which encourages Member States to pursue effective policies to reduce greenhouse gas (GHGs) emissions, including through appropriate changes in the behavioral habits of citizens. In this respect, among the main sectors involved, transport and mobility should certainly be mentioned. National institutions should be adequately involved in order to achieve the objectives set; in this regard, universities must certainly be considered for their educational value. These latter, for instance, could commit to improving the environmental performance of the mobility of their commuter students (to a not insignificant extent), since commuting modes are often the cause of high CO2 emissions; indeed, they still largely involve the use of internal combustion engines based on fossil fuels. In this paper, the effectivenes... [more]

Municipal waste management in the EU has been challenged to a thorough transformation towards a Circular Economy. It is addressed by a number of quantitative policy targets, including a restriction on municipal waste landfilling to 10% in 2035. This paper presents the data on municipal waste composition in a large Polish city, based on thorough waste sorting analyses. On average, 374 kg of municipal waste is collected per capita in Wroclaw, of which 41% are separately collected fractions. The approach to implement the EU recycling targets until 2035 is presented, including an increase of sorting and recycling efficiency and a significant share of recyclables being retrieved from the residual waste fraction. Notwithstanding the recycling targets, an important stream of residual waste remains, amounting to 200 k ton in 2020 and approx. 130 k ton in 2035, which is available for energy recovery. The respective LHV values range from 8.5 to 7.6 MJ/kg. The results indicate that the residual w... [more]

The mining industry plays an extremely important strategic role in China’s economic and social development. In the new era of pursuing circular/green/efficient development, the evaluation of the total factor environmental efficiency (TFEE) of China’s mining industry is essential for alleviating resource waste and environmental pollution. The Epsilon-Based Measure (EBM) model effectively solves the shortcomings of radial and non-radial DEA models. In addition, the Malmquist−Luenberger (ML) index can measure the dynamic change of efficiency value. Combining the EBM model and the ML productivity index, this paper evaluates the TFEE from the static and dynamic perspective in China’s 31 provincial mining industries over the period 2007−2016. The Theil index is employed to reveal the root of the overall provincial TFEE gap (OGTFEE) in China’s mining industry. The results show that the average total factor static environmental efficiency (TFSEE) of China’s provincial mining industry exhibits... [more]

Wellbore instability resulting from deep mudstone hydration severely restricts the development of oil and gas resources from deep reservoir in western China. Accurate evaluation of drilling fluid inhibition properties plays an important role in selecting drilling fluid that can control deep mudstone hydration and then sustain wellbore stability. The previous evaluations are conducted by qualitative analysis and cannot consider the influence of complex hydration conditions of deep mudstone (high temperature, high pressure and flushing action). The study proposes a quantitative method to evaluate drilling fluid’s inhibition property for deep mudstone under natural drilling conditions. In this method, the cohesive strength of mudstone after hydration is adopted as the inhibition index of the tested drilling fluid. An experimental platform containing a newly designed HPHT (High pressure and high temperature) hydration experiment apparatus and mechanics characterization of mudstone after hy... [more]

This paper reviews the major researchers of liquid, immersion, and two-phase cooling. Currently, liquids are used instead of air to cool the growing data centers. Immersion cooling shows a higher heat transfer coefficient than conventional cooling (<37 W/cm2). Because the use of liquids with high global warming potentials is prohibited, the number of liquids that can be used is limited. This paper discusses the existing, relevant literature from researchers who have studied the issue at least thrice. The authors were divided into those who focused on the surface and those who formed a structure on the surface. In summary, the authors suggested the following research directions: The experimental conditions of porous foam are not diverse, and there is a concern about the separation of foam and coating into the tub. The experimental conditions of the immersion tub should also be varied according to the heat and pressure over time. Structure-level research shows higher performance than... [more]

Universal access to energy is a global challenge for sustainable development that requires granting last-mile access to energy services to rural and isolated communities. However, achieving access is not sufficient: it must be done affordably, reliably and with an adequate quality. Universal access to energy goes beyond the mere selection of a technical solution or infrastructure; it demands being able to design management models for projects aiming to guarantee that households may access energy services in a sustainable way. This study analyzes the main elements (i.e., governance, technological and business models) of management models in universal access to energy projects and their impact on the different dimensions of sustainability (i.e., social, environmental, and economic). The study then presents three case studies of rural electrification projects having different configurations of the management model, with special focus on the differences in the business model, and it analyz... [more]

Modern theories that make up the paradigm of sustainable development, and the best practices derived from them, are based on the consistency of individual and public needs, factors of economic growth and ecosystem conservation [...]

Energy consumption in residential, commercial and industrial buildings is one of the major contributors to global warming. Due to the increase in the latter, and growing global energy crisis, more attention is being paid to renewable energy resources (RES). The use of innovative concepts in existing buildings is gaining popularity to provide reduction in energy requirements for electricity, heating and cooling. In this paper, an electricity, heating and cooling cooperation mechanism among neighboring buildings with RES is proposed. It relies on adjusting the RES tariff with a mutual agreement between the neighboring buildings, with an aim to minimize the operational costs. For this purpose, a mathematical model is developed for joint energy cooperation, where surplus energy in one of the buildings is shared with others, thereby reducing dependency on the grid. The optimization structure of the environment friendly energy cooperation is nonlinear, which is linearized using the McCormick... [more]

This paper presents the results of testing the electrical strength of an insulating system in a vacuum obtained from three noble gases: argon, neon, helium, and air. The breakdown voltages were measured for contact gaps of 1 mm and 2 mm. A difference was observed in the pressure range where the electrical strength was kept constant. The chamber filled with helium residual gases lost its insulating properties at the highest pressure among the tested gases (2.00 × 100 Pa at contact gap d = 2 mm), while the chamber filled with argon gas lost its insulating properties at the lowest pressure among the tested gases (2.00 × 10−1 Pa at contact gap d = 2 mm). After a decrease in electrical strength, an intense glow discharge was observed. A theoretical description related to the initiation of an electrical breakdown in vacuum insulating systems is also presented. The situation in which the discharge chamber with a contact system was filled with the mentioned gases was analyzed. The mean free pa... [more]

Hydropower depends on the elevation head and water flow of a river. However, other factors must be considered, such as the risk associated with surface processes and environmental factors. The study aims to analyze a landscape’s dynamics and locate potential sites for small-scale hydropower systems (<10 MW) using a geographic information system, the curve number method, and the TopoToolbox with a digital elevation model and available spatial datasets. Across Bohol Island in the central Philippines, the study found 94 potential sites with hydraulic heads ranging from 20−62.4 m, river discharges between 0.02 to 9.71 m3/s, and a total hydropower capacity of 13.595 MW. The river profile analysis classified the sites to five levels of risk to geo-hazards, with three-fourths of the sites being at ‘high’ to ‘very high’ risk levels while more than 50% of the total power can be generated in ‘low’ risk areas. Land-use and population constraints reduced the sites to 25 and the hydropower capac... [more]