An integrated geological and geophysical approach is presented for the recognition of unconventional targets in the Miocene formations of the Carpathian Foredeep, southern Poland. The subject of the analysis is an unconventional reservoir built of interlayered packets of sandstone, mudstone and claystone, called a “heterogeneous sequence”. This type of sequence acts as both a reservoir and as source rock for hydrocarbons and it consists of layers of insignificant thickness, below the resolution of seismic data. The interpretation of such a sequence has rarely been based on seismic stratigraphy analysis; however, such an approach is proposed here. The subject of interpretation is high-quality seismic data of high resolution that enable detailed depositional analysis. The reconstruction of the depositional history was possible due to the analysis of flattened chronostratigraphic horizons (Wheeler diagram). The identification of depositional positions in a sedimentary basin was the first... [more]

Solar radiation exposure at work is a relevant heath risk in the construction sector. Our objective was to monitor for a full month the individual solar ultraviolet radiation (UVR) exposure of a group of three construction workers active in Siena (latitude = 43°19′ N), a town in Tuscany (Italy). We used personal electronic dosimeters “X-2012-10” (Gigahertz, Turkenfeld, Germany) to register the UV irradiance in the UVA and UVB/C regions separately and we consulted a specific database to retrieve the corresponding ambient erythemal UVR dose (cloud-free conditions). In spring, construction workers from central Italy received a quite variable UVR dose, between 0.9 standard erythemal doses (SED) and 15.6 SED/day, 5.7 on average. Considering the proportion with respect to the potential environmental exposure, personal exposure resulted between 2.7% and 31.2% of the ambient erythemal dose, with a mean value of 12.5%. Cumulatively, the three construction workers received in one working month a... [more]

Biodegradable containers support zero-waste initiatives when alternative end-of-life scenarios are available (e.g., composting, bio digestion). Thermoplastic starch (TPS) has emerged as a readily biodegradable and inexpensive biomaterial that can replace traditional plastics in applications such as food service ware and packaging. This study has two aims. First, demonstrate the thermoformability of starch/polycaprolactone (PCL) as a thermoplastic material with varying starch loadings. Second, incorporate biochar as a sustainable filler that can potentially lower the cost and enhance compostability. Biochar is a stable form of carbon produced by thermochemical conversion of organic biomass, such as food waste, and its incorporation into consumer products could promote a circular economy. Thermoformed samples were successfully made with starch contents from 40 to 60 wt.% without biochar. Increasing the amount of starch increased the viscosity of the material, which in turn affected the c... [more]

It remains challenging to develop a techno-economically feasible method to remove alkali and alkaline earth metal species (AAEMs) from rice husk (RH), which is a widely available bioresource across the world. In this study, the AAEMs leaching effect of aqueous phases of both bio-crude prepared by hydrothermal liquefaction (AP-HT) and bio-oil prepared by pyrolysis (AP-Pyro) of RH were systematically investigated. The results indicated that although the acidity of AP-HT and AP-Pyro are much lower than that of HCl, they performed a comparable removal efficiency on AAEMs (Na: 56.2%, K: 96.7%, Mg: 91.0%, Ca: 46.1% for AP-HT, while Na: 58.9%, K: 96.9%, Mg: 94.0%, Ca: 86.3% for AP-Pyro) with HCl. The presence of phenolics in bio-oil could facilitate the penetration of water and organic acids into the inner area of RH cells, thus enhancing the AAEMs removal via chelate reactions. The thermal stability of leached RH during thermochemical conversions was studied via TG and Py-GC-MS. The results... [more]

Motorized spindle system is one of the crucial components affecting the machine tools energy performance. Many previous studies have examined its energy optimization problems, however, most such studies focused mainly on parameters optimization to improve material removal energy efficiency or reduce total energy consumption. A missing research area is energy optimization problem considering thermal stability and productivity constraints simultaneously. Against this background, an energy optimization approach of motorized spindle system is presented with consideration of thermal stability and productivity adequately, with the goal of maximization of energy efficiency and material removal rate, and minimization of spindle average temperature which is closely associated with thermal stability. Firstly, the energy characteristics of motorized spindle and its cooling system are mathematically modelled. Then, a multi-objective optimization model is established to take the maximum energy effi... [more]

Carbonated water injection (CWI) is a technology with significant sweep efficiency advantages in enhanced oil recovery (EOR), but the mechanism of the microscopic diffusion of CO2 is still unclear. In this study, the diffusion mechanism of CO2 from the aqueous phase to the oleic phase in a carbonated water (CW)−decane system was investigated by the molecular dynamics simulation method. This investigation also explored the diffusion capacity and interface properties of the CW−decane system. We found that the movement of CO2 from the aqueous phase to the oleic phase can be divided into two processes: the accumulation behavior of CO2 moving from the aqueous phase to the interface, and the dissolution behavior of CO2 moving from the interface to the decane phase. The increase in the temperature and CO2 concentration in carbonated water can improve the decane phase’s diffusion ability and reduce the water−decane interfacial tension. The difference in the interactions between water−CO2 and d... [more]

Stirling engine is a favorable technique in the application of waste heat recovery or cogeneration system. This paper aims at developing a beta-type Stirling engine which is operated at moderate heating temperature (773−973 K). Rhombic drive mechanism is utilized to make coaxial motion of displacer and piston. Based on the proposed dimensions, a theoretical model combining thermodynamic and dynamic analysis is built to predict the performance of the Stirling engine. Thermodynamic analysis deals with variations of properties in each chamber while dynamic analysis handles the resultant shaft torque produced by the Stirling engine. Furthermore, a prototype engine is manufactured, and experimental test is carried out to validate the simulated results in this research. Under heating temperature of 973 K, charged pressure of 8 bar, rotation speed of 1944 rpm, shaft power of 68 W is obtained from the prototype Stirling engine. Power density is calculated to be 1.889 W-c.c.−1 by theoretical pr... [more]

Using an analytical methodology taking into account heat flow density data, frictional heating, temperature variations due to the re-equilibrated conductive state after thrusting and geological constrains, we calculated surface heat flow, geotherms and isotherms along a balanced and restored regional geological cross-section. Our results highlight the impact of frictional heating produced by thrusts on the thermal structure of the study area, leading to a raising of the isotherms both in the inner Albanides to the E and in the Adriatic sector offshore. Minimum values of Qs in the surroundings of Tirana and the reconstructed 2D thermal structure suggest less favorable conditions for exploitation of geothermal energy, besides the direct use (Borehole Heat Exchanger-Geothermal Heat Pump systems). Nevertheless, the occurrence of the “Kruja geothermal zone”, partially overlapping this area and including hot spring manifestations, emphasize the structural control in driving hot fluids to the... [more]

Getting a clear understanding of the fluid velocity field in underground porous media is critical to various engineering applications, such as oil/gas reservoirs, CO2 sequestration, groundwater, etc. As an effective visualization tool and efficient transport behaviors solution algorithm, the streamline-based method was improved significantly by numerous studies conducted in the last couple of decades. However, the implementation of streamline simulation is still challenging while working with Finite Element Method (FEM) over 3D tetrahedral domains, where the mass conservation is not guaranteed. Considering the increased computational cost to enforce mass conservation in FEM and additional complexity, a new three-dimensional streamline tracing algorithm is presented that only relies on the velocity vector of a flow field on each vertex of a tetrahedron in a 3D unstructured mesh system. Owning to the shape functions and transformation equations between the master element and actual eleme... [more]

The construction sector is a great contributor to global warming both in new and existing buildings. Minimum energy buildings (MEBs) demand as little energy as possible, with an optimized architectural design, which includes passive solutions. In addition, these buildings consume as low energy as possible introducing efficient facilities. Finally, they produce renewable energy on-site to become zero energy buildings (ZEBs) or even plus zero energy buildings (+ZEB). In this paper, a deep analysis of the energy use and renewable energy production of a social dwelling was carried out based on data measurements. Unfortunately, in residential buildings, most renewable energy production occurs at a different time than energy demand. Furthermore, energy storage batteries for these facilities are expensive and require significant maintenance. The present research proposes a strategy, which involves rescheduling energy demand by changing the habits of the occupants in terms of domestic hot wate... [more]

A characteristic feature of lightweight constructions is their low thermal mass which causes high internal temperature fluctuations that require high heating and cooling demand throughout the year. Phase change materials (PCMs) are effective in providing thermal inertia to low-thermal-mass buildings. This paper aims to analyse the thermal behaviour of two proposed lightweight buildings designed for homeless people and to investigate the potential benefit achievable through the use of different types of PCM in the temperate climatic conditions of Christchurch, New Zealand. For this purpose, over 300 numerical simulations were conducted using DesignBuilder® simulation software. The bulk of the simulations were carried out under the assumption that the whole opaque building envelope is equipped with PCM. The results showed significant energy saving and comfort enhancement through the application of PCMs. The integration of PCM in single-structure components led to substantial energy savin... [more]

This paper considers simultaneous wireless information and power transfer (SWIPT) in a decode-and-forward two-way relay (DF-TWR) network, where a power splitting protocol is employed at the relay for energy harvesting. The goal is to jointly optimize power allocation (PA) at the source nodes, power splitting (PS) at the relay node, and time allocation (TA) of each duration to minimize the system outage probability. In particular, we propose a static joint resource allocation (JRA) scheme and a dynamic JRA scheme with statistical channel properties and instantaneous channel characteristics, respectively. With the derived closed-form expression of the outage probability, a successive alternating optimization algorithm is proposed to tackle the static JRA problem. For the dynamic JRA scheme, a suboptimal closed-form solution is derived based on a multistep optimization and relaxation method. We present a comprehensive set of simulation results to evaluate the proposed schemes and compare... [more]

Vegetable oil is extracted from oil rich seeds, such as soybeans. Genetic engineering of green plants to accumulate oil in vegetative tissue is a future source of oil that promises increased land productivity and the use of marginal lands. However, the low concentration of lipids in current engineered plant biomass samples makes the oil extraction process challenging and expensive. In this study, liquid hot water (LHW) pretreatment was investigated to enhance oil recovery from the solids and increase enzymatic hydrolysis efficiency of such feedstocks. Corn germ meal was chosen as a model feedstock representing lipid-producing energy crops. Germ meal was pretreated at 160 and 180 °C for 10 and 15 min at 20% w/w solids loading. Enzymatic hydrolysis on the pretreated solid was performed. After pretreatment, the oil concentration increased by 2.2 to 4.2 fold. The most severe pretreatment condition of LHW, at 180 °C for 15 min, gave the maximum oil concentration (9.7%, w/w), the highest tri... [more]

For improving control methods in the thermal environment, various algorithms have been studied to satisfy the specific conditions required by the characteristics of building spaces and to reduce the energy consumed in operation. In this research, a network-based learning control equipped with an adaptive controller is proposed to investigate the control performance for supply air conditions with maintaining the levels of indoor thermal comfort. In order to examine its performance, the proposed model is compared to two different models in terms of the patterns of heating and cooling energy use and the characteristics of operational signals and overshoots. As a result, the energy efficiency of the proposed control has been slightly decreased due to the energy consumption increased by precise controls, but the thermal comfort has improved by about 10.7% more than a conventional thermostat and by about 19.8% more than a deterministic control, respectively. This result can contribute to the... [more]

It is necessary to devise innovative techniques to design new high-performance tandem solar cells to meet increasing energy needs. In this study, the theoretical efficiency of intermediate band solar cells (IBSCs) was increased by integrating them with tandem solar cells to produce intermediate band tandem solar cells (IBTSCs). The spectral splitting analysis indicated that the efficient absorption of sub-photon energies was necessary to ensure optimal performance of the IBSCs at each junction of the IBTSC. For this calculation, we assumed all absorption of sub-photon energies are unity. In addition, we applied the variation of absorptivity to the detailed balance limit of a double-junction (DJ) IBTSC. Furthermore, we included the impact of series and shunt resistances of a typical DJ IBTSC to investigate the variations in electrical parameters (short circuit current, open circuit voltage). The performance efficiency also depended on the illumination concentration due to the charge car... [more]

Measuring the probability of flood risk is a key issue in the economics of natural disasters. This discipline studies actual and potential effects of natural disasters on the functioning of economic systems. In traditional economic understanding, it is assumed that both the decision making processes and market processes operate within a certain level of access to information. It is also assumed that the effects of certain phenomena are predictable. However, a natural disaster is difficult to predict. It is hard to predict the time of its occurrence, its impact, direct exposure to its effects and finally, its social and economic results. Exposure to a random hazard, combined with the amount of damage resulting from its potential materialization, is called risk. In this study, the authors focus on presenting a method for quantification of the random element of flood risk. We are using measurement data for cross-border areas between Poland and Germany who witnessed a flood of the century... [more]

Efforts to achieve Sustainable Development Goals (SDGs) have resulted in enhancement of the position of microalgae in feedstocks for food, feed, healthcare, and biofuels. However, stabile microalgal biorefineries require a sustainable and reliable management system of microalgae, which are sensitive to environmental changes. To expand microalgal applicability, assessment and maintenance of microalgal quality are crucial. Compared with conventional methods, including hemocytometry and turbidity, an automated- and image-based cell counter contributes to the establishment of routine management of microalgae with reduced work burden. This review presents the principle of an automated cell counter and highlights the functional capacities of the device for microalgal management. The method utilizing fluorescence function to evaluate the chlorophyll integrity of microalgae may lay the groundwork for making a large variety of microalgal biorefineries, creating an important step toward achievin... [more]

There is a burden of adequate energy supply for meeting demand and reducing emission to avoid the average global temperature of above 2 °C of the pre-industrial era. Therefore, this study presents the exergoeconomic and environmental analysis of a proposed integrated multi-generation plant (IMP), with supplemental biomass-based syngas firing. An in-service gas turbine plant, fired by natural gas, was retrofitted with a gas turbine (GT), steam turbine (ST), organic Rankine cycle (ORC) for cooling and power production, a modified Kalina cycle (KC) for power production and cooling, and a vapour absorption system (VAB) for cooling. The overall network, energy efficiency, and exergy efficiency of the IMP were estimated at 183 MW, 61.50% and 44.22%, respectively. The specific emissions were estimated at 122.2, 0.222, and 3.0 × 10−7 kg/MWh for CO2, NOx, and CO, respectively. Similarly, the harmful fuel emission factor, and newly introduced sustainability indicators—exergo-thermal index (ETI)... [more]

District heating (DH) is an energy efficient building heating system that entails low primary energy consumption and reduced environmental impact. The estimation of the required heating load provides information for operators to control district heating systems (DHSs) efficiently. It also yields historical datasets for intelligent management applications. Based on the existing virtual sensor capabilities to estimate physical variables, performance, etc., and to detect the anomaly detection in building energy systems, this paper proposes a virtual sensor-based method for the estimation of DH energy consumption in a residential building. Practical issues, including sensor absences and limited datasets corresponding to actual buildings, were also analyzed to improve the applicability of virtual sensors in a building. According to certain virtual sensor development processes, model-driven, data-driven, and grey-box virtual sensors were developed and compared in a case study. The grey-box v... [more]

This paper presents an application of a framework for Big Data Analytical Process and Mapping—BAProM—consisting of four modules: Process Mapping, Data Management, Data Analysis, and Predictive Modeling. The framework was conceived as a decision support tool for industrial business, encompassing the whole big data analytical process. The first module incorporates in big data analytical a mapping of processes and variables, which is not common in such processes. This is a proposal that proved to be adequate in the practical application that was developed. Next, an analytical “workbench” was implemented for data management and exploratory analysis (Modules 2 and 3) and, finally, in Module 4, the implementation of artificial intelligence algorithm support predictive processes. The modules are adaptable to different types of industry and problems and can be applied independently. The paper presents a real-world application seeking as final objective the implementation of a predictive mainte... [more]

The issues that are presented in the article concern the broadly understood parameters of the operation of lighting fixtures in mixed systems and the improvement of the quality of electricity, considered in two aspects: as receivers of the energy consumed, determining and generating reactive power, influencing the asymmetry of currents and the production of higher harmonics, determined by the parameters of current and supply voltage (independent of the consumers connected at the connection point), which are influenced by the consumers that are connected at the connection point. After the tests, in order to improve the quality of energy, a proprietary program for the design of passive resonance filters was developed. A wide range of measurements of various types of lighting devices was carried out in single, complex, and mixed systems. Luminaires with discharge and LED sources were selected for the analysis of energy parameters. The tests were carried out in accordance with the IEEE 145... [more]

Concerns on the lack sustainable end-of-life options for wind turbines have significantly increased in recent years. To ensure wind energy continuous growth, this research develops a novel spatiotemporal methodology that sustainably handles end-of-life activities for wind equipment. This research introduces the Global Wind Inventory for Future Decommissioning (GoWInD), which assesses and characterizes wind turbines according to individual spatiotemporal decommissioning and sustainability attributes. Applying data from GoWInD, the research developments networks of end-of-life (EoL) centers for wind turbines. The placement and operational levels of EoL centers optimize sustainable decommissioning according to changing spatiotemporal features of wind turbines. The methodology was evaluated for the United States, developing the United States Global Wind Inventory for Future Decommissioning (US—GoWInD), implementing the network of United States end-of-life (US—EoL) centers. Significant imba... [more]

This article presents a 125-day experiment to investigate model predictive heat pump control. The experiment was performed in two parallel operated systems with identical components during the heating season. One of the systems was operated by a standard controller and thus represented a reference to evaluate the model predictive control. Both test rigs were heated by an air-source heat pump which is influenced by real weather conditions. A single-family house model depending on weather measurement data ensured a realistic heat consumption in the test rigs. The adapted model predictive control algorithm aimed to minimize the operational costs of the heat pump. The evaluation of the measurement results showed that the electrical energy demand of the heat pump can be reduced and the coefficient of performance can be increased by applying the model predictive controller. Furthermore, the self-consumption of photovoltaic electricity, which is calculated by means of a photovoltaic model and... [more]

Vapor compression systems (VCS) cover a wide range of applications and consume large amounts of energy. In this context, previous research identified the optimization of the condenser fans speed as a promising measure to improve the energy efficiency of VCS. The present paper introduces a steady-state modeling approach of an air-cooled VCS to predict the ideal condenser fan speed. The model consists of a hybrid characterization of the main components of a VCS and the optimization problem is formulated as minimizing the total energy consumption by respectively adjusting the condenser fan and compressor speed. In contrast to optimization strategies found in the literature, the proposed model does not relay on algorithms, but provides a single optimization term to predict the ideal fan speed. A detailed experimental validation demonstrates the feasibility of the model approach and further suggests that the ideal condenser fan speed can be calculated with sufficient precision, assuming con... [more]

Reactive power management in microgrids with high penetration of distributed renewable energy sources (DRESs) is challenging. The intermittent generation of DRES makes the power management cumbersome. Generally, Flexible AC Transmission System (FACTS) devices such as Distribution Static Compensator (DSTATCOM) are employed for reactive power compensation in microgrids. However, for effective results in microgrids, coordinated operation between DSTATCOM and Distributed Energy Resources (DERs) is required. In this paper, IEC 61850 communication is proposed for realizing coordinated operation between microgrid controller (MGCC), DSTATCOM and DERs. In microgrids, there may be large number of DERs dispersed over a large area. Hence, the underlying communication network technology for IEC 61850 communication must be highly scalable with wide range. Recently developed communication technology Long Term Evolution (LTE) is a promising solution since it offers high data rates, reliability, scalab... [more]