In this paper, a flexible metamaterial-based electromagnetic harvester is proposed for wearable applications at microwave regime. The proposed harvesting structure is composed of a modified ...configuration from the conventional Split-Ring Resonator (SRR) inclusion and is printed on a grounded very thin flexible substrate. The proposed wearable harvester structure provides several interesting features, including its robustness, sustainability, and ease of integration with flexible electronics and sensors. Numerical full-wave studies are conducted, where results from a periodic arrangement of the proposed harvesting unit cell along with several two-dimensional arrays of harvesters are presented and discussed. Based on the numerical studies, the proposed electromagnetic harvesting structure exhibits good efficiency capability of power conversion from radio frequency received power to alternating-current harvested power across collecting loads above 90% for the three studied cases.
Nowadays, the global energy system is in a transition phase, in which the integration of renewable energy is among the main requirements for attenuating climate change. Wind power is a major ...alternative to supply clean energy; hence, its widespread penetration is being pursued in all end-use sectors. In particular, it is currently noteworthy to analyze the feasibility of deploying small-scale wind power technology to provide cleaner and cheaper energy in the residential sector. As a first step, a technical assessment must be carried out to provide crucial information to intensive energy consumers, providers of small-scale wind power technology, electric energy distribution utilities, and any other party, to help them decide whether or not to deploy small-scale wind turbines. With this aim, we propose to perform such an analysis using a suitable probabilistic paradigm to solve complex decision-making problems with uncertainty, namely Bayesian Intelligence, since wind resources and energy demands are intermittent variables, properly characterized by probability distribution functions. Then, the problem of determining the technical feasibility can be formulated as an investigation into whether or not small-scale wind turbine technology can produce enough energy to cover the excess demand of intensive energy residential consumers to get off high-priced tariffs. For this purpose, we introduce a novel model based on probabilistic reasoning to assess the suitability of small-scale wind turbine technology to produce the said energy, taking into consideration the availability of wind resources and the energy pricing structure. To demonstrate the usefulness and performance of the proposed model, we consider a case study of deploying 5 and 10 kW wind turbines and analyze the feasibility of their implementation in Mexico, where the energy pricing structure and scattered wind resource availability pose difficult challenges.
We examine how per capita income and relative fossil fuel prices influence the use of non-renewables (oil, coal and natural gas), nuclear, hydroelectric, and other renewables in electricity ...generation. Panel regressions are estimated using the fully modified ordinary least squares method and data across 29 countries (1985-2017).We include both developed and developing economies whose classification status is allowed to vary during the sample period depending on per capita income.Results suggest that oil prices play a dominant role in boosting the use of renewables, while gas serves as a transition fuel. For developing nations, income is a significant constraint in the use of renewables, while coal and gas prices do not significantly influence the use of hydro and nuclear. This finding supports a shift away from the exclusive use of pricing mechanisms towards set targets linked to per capita income to encourage the use of renewables in developing economies.
The policy synergy of coal resource-rich areas directly affects the process of regional green transformation and high-quality development. Shanxi, Shaanxi and Inner Mongolia are important coal energy ...bases, and studying the energy and environmental policies of these three provinces is of great significance to sustainable development. Using social network analysis, the Latent Dirichlet Allocation (LDA) topic model and textual similarity methods, we conducted a synergistic study of policy issuance subjects and policy text contents of Shanxi, Shaanxi and Inner Mongolia from both horizontal and vertical perspectives. The results show that: (1) in the policy subject dimension, Shanxi had the highest degree of synergy, but overall the synergy in all three provinces was insufficient, and the number of multi-subject joint texts was relatively small; (2) in the policy content dimension, the textual similarity and goal consistency between Inner Mongolia and the Central Government were better than that of Shaanxi and Shanxi. Therefore, the region of “Shanxi–Shaanxi–Inner Mongolia” should improve the synergistic ability of policy issuance subjects; it should also pay attention to the linkage and refinement of the policy content, and make flexible innovations based on the compatibility with the Central policy incentives, to better promote the low-carbon and green transformation of coal resource-rich areas.
Coal resources in China are developed in several regions with shallow groundwater, and large mining-related surface subsidence can have negative impacts on agriculture, land and water resources as ...well as existing and future socio-economic resources. All these are important for sustainable resource development. Dynamic subsidence reclamation (DSR) planning concepts are evaluated here for another case study with analyses over a 11-year period. In DSR topsoil, subsoil, farming, and water resources management are dynamically synergized concurrent with mining ahead of and behind the projected dynamic subsidence trough. The study area involved mining five longwall faces (and post-mining reclamation) to assess if DSR could have improved both the environment and socio-economic conditions for post-mining land use as compared to using traditional reclamation (TR) and TR-modified (TR(MOD)) approaches. The results show that: (1) Upon final reclamation, farmland area and water resources in DSR and TR (MOD) will have increased by 5.6% and 30.2% as compared to TR. Removing soils ahead of mining before they submerge into water is important for farmland reclamation and long-term economic development. (2) Due to topsoil and subsoil separation and storage in the DSR plan, reclaimed farmland productivity should recover quickly and agriculture production should be larger than TR and TR(MOD) plans. (3) For a simplified economic model, the total revenue in the DSR plan should be 2.8 times more than in TR and 1.2 times larger than in TR (MOD) plan. (4) The total net revenue of the TR(MOD) plan should be increased by 8.1% as compared with the TR plan. The benefits will be much greater for analyses over longer periods. Overall, the DSR plan will allow for an improved socio-economic environment for new businesses to support disrupted workforces during and after mining.
The current era of energy production from agricultural by-products comprises numerous criteria such as societal, economical, and environmental concerns, which is thought to be difficult, considering ...the complexities involved. Making the optimum choice among the various classes of organic waste substances with different physio-chemical characteristics based on their appropriateness for pyrolysis is made possible by a ranking system. By using a feasible model, which combines several attributes of decision-making processes, it is possible to select the ideal biomass feedstock from a small number of possibilities based on relevant traits that have an impact on the pyrolysis. In this study, a multi-criteria decision-making (MCDM) technique model based on the weight calculated from the analytical hierarchy process (AHP) tool has been applied to obtain a ranking of different types of agro-waste-derived biomass feedstock. The technique of order preference by similarity to ideal solution (TOPSIS) is used to examine the possibilities of using/utilizing locally available biomass. From this point of view, multi-criteria are explained to obtain yield maximum energy. The suggested approaches are supported by the experimental findings and exhibit a good correlation with one another. Six biomass alternatives and eight evaluation criteria are included in this study. Sawdust is the highest-ranking agricultural waste product with a closeness coefficient score of 0.9 out of the six biomass components that were chosen, followed by apple bagasse with 0.8. The hybrid approach model that has been built can be evaluated and validated for the ranking method using the Euclidian distance-based approximation. This study offers a unique perspective on decision-making, particularly concerning thermo-chemical conversion.
Noise is considered as one of the challenging problems in big cities. However, this noise could be utilized in producing energy especially in dense urban areas. Sound as a form of mechanical energy, ...it can be converted to electric energy through many approaches including heating, by using the diaphragm and through using piezoelectric materials. This research aims at utilizing noise through using piezoelectric materials as an approach of conversion to produce green sustainable electric energy that can be used to decrease the energy consumption from non-renewable sources and utilizing this energy in street lighting. The study was carried in three bus stations in Alexandria by having measurements during weekdays and weekends in order to study the noise produced in the selected stations and the amount of electric energy that could be produced and utilized in street lighting. The noise level index LDEN was calculated for each of the three selected locations. The equivalent noise level values were always exceeding the limits through the day, evening and night. At daytime they ranged between 75-85 dB which is higher that the permissible limit by 10-20 dB, at evening they ranged from 80-85 dB which is also higher than the permissible limit with 20-25 dB and at the night they ranged from 75-80 dB which is higher by 20-25 dB than the permissible limit. The research concluded that utilizing noise using the piezoelectric material is successful. The electric energy produced from an area of 1.45 m2 containing 690 piezoelectric QB220-503YB transducers at each of the selected stations was about 0.024 watt hr. This amount of electric energy is too small to be used in an application. So the application area should be maximized to hundreds of square meters to produce beneficial electric energy that can be used in lighting 1 LED street lamp or it can be stored and used when needed in applications that use greater amount of electric energy and this would help in reducing the energy consumed.
There exists a political goal in Sweden and elsewhere to increase the use of renewable energy and wind power seems to be a favourable choice from an environmental perspective. However, although the ...public generally expresses a positive attitude towards wind power, the experience often shows that specific wind power projects face resistance from the local population. This paper analyses the attitudes towards wind power among the electricity consumers as well as the foundations of these attitudes. Results are based on a postal survey that was sent out to 1000 Swedish house owners. According to the results, the public is generally positive towards wind power. The probability of finding an average individual in support of wind power decreases with age and income. People with an interest in environmental issues are, however, more likely to be positive towards wind power than the average respondent and the results do not support the NIMBY-hypothesis. In addition, people that are more inclined to express public preferences are also more likely to be positive towards wind electricity than people who are less inclined to do so. These results imply, for instance, that the potential of markets for “green” electricity may be limited, other support schemes is thus required if the politically stated goal to increase wind power capacity is to be fulfilled.
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