Natural Energy Sources Research Articles

A Practical Tool to Generate Complex Energy System Configurations Based on the SYNTHSEP Methodology

Traditional fossil fuelled power plants are commonly based on steam Rankine cycle or Brayton Joule cycle. Using water or air as working fluid is obviously the most obvious choice for the wide availability of these substances in nature. However, the scarcity of natural energy sources and the strong need of reducing environmental impact have necessarily drawn the research to new energy systems configurations operating with other working fluids, which are able to recover lower temperature sources, such as Sun or industrial wasted heat. The variety of new working fluids (refrigerants or organic fluids) widens the choice to a variety of configurations that can be tailored to the specific source characteristics and boundary constraints. It is not always easy or even possible to conceive the best configuration for given specifications with the mere experience of a common designer. To design a new system configuration, the designer normally uses some “non-codified rules” deriving from his knowledge of basic thermodynamics and energy engineering. This paper aims instead at showing a practical tool that is based on a new methodology, named SYNTHSEP, to generate new energy system configurations. This methodology starts from the simple thermodynamic cycles operated by a given fluid made up of the four fundamental processes (compression, heating, expansion and cooling) and uses a rigorous set of codified rules to build the final system configuration. The paper presents the basics of the new methodology and how it has been implemented in a practical tool that simply requires the information about the elementary cycles and their shared processes as input data.

Characterization of a Photosynthesis-based Bioelectrochemical Film Fabricated with a Carbon Nanotube Hydrogel

Microbial photo-bioelectrochemical cells (MPCs) generate energy through the photosynthetic process of microorganisms. However, all MPCs developed to date require oxidation-reduction mediators to transport electrons from the photosynthetic cells to the electrodes, due to which the power conversion efficiencies of such MPCs are usually low. In this study, we developed a method to increase the power conversion efficiency of MPCs by immobilizing Chlorella cells with multiwall carbon nanotubes (MWCNTs) using a UV-cured polyethylene glycol diacrylate (PEG-DA) hydrogel film within a microfluidic chamber. We report that the photosynthetic current obtained in our setup is ∼3-fold higher than that in normal Chlorella cells. Chronoamperometric measurements of hydrogel films with different ratios of MWCNTs and Chlorella indicate that more current is produced at higher MWCNT concentrations. Scanning electron micrographs were used to visualize immobilized MWCNTs and Chlorella cells, and energy dispersive spectrometry was used to quantify the carbon content of the hydrogel film. Impedance measurements also indicated that the increased current was due to improved harvesting of photosynthetic energy. The findings of this study would provide novel insights to design systems that use natural renewable energy sources for the production of electricity.

From Battery Enabled to Natural Harvesting: Enzymatic BioFuel Cell Assisted Integrated Analog Front-End in 130nm CMOS for Long-Term Monitoring

Biofuel cell as a natural energy source is a promising biocompatible technology which harvests the blood glucose into usable energy and replaces the toxic lithium-based battery solutions. However, the promise of this perennial non-toxic power is tempered by its unstable operation and low-voltage outputs leading to very limited operational lifetimes. This paper demonstrates a glucose-powered analog front-end with superior noise performance, which is enabled by standalone enzymatic biofuel cells operating for more than 30 min on active power without replenishment. Two biofuel cells are stacked to realize 0.5V output using commercially available glucose oxidase and the enzyme stability is improved via multipoint crosslinks by glutaraldehyde. To mitigate the effects of noisy and temperature-sensitive pseudo-resistors, a switched-resistor biasing scheme is applied to the input amplifier with the measured input-referred noise of 0.31 μV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RMS</sub> only. The proposed hybrid power scheme uses 1.6 μW from the battery with 1.9 μW provided by the biofuel cells. The entire analog front-end including a cascaded dual-supply amplifier with switched-capacitor SAR ADC and single-opamp relaxation oscillator occupies 1.12 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Measured of only 1.1 dB and 19.2 nV/√Hz, respectively, with noise (power) results show on-chip gain and noise variations across temperature efficient factor of 1.46 (1.63).

Study of Redox and Pseudocapacitive Processes of K-Ion Storage Using New Transition Metal Oxides Derived from PBA Type-Materials

The fast growing use of natural energy sources such as solar and wind to generate electricity, requires the development of reliable, affordable, and efficient electric energy storage systems [1]. Thus, electrochemical capacitor systems can offer excellent devices showing high power (>10 kW kg-1), high rate capability and long cycle life (>1 000 000 cycles) [2]. Many kind of materials have been widely investigated as supercapacitor electrodes, such as carbon materials, graphene-based composites of metal hydroxides and metal oxides. In this work, new pseudocapacitive materials were obtained by thermal descomposition of cyanometalates (PBAs) obtained by precipitation over different carbon structures (graphene oxide, carbon nanotubes and mesoporous carbon). The materials were characterized using XRD, Raman, ATR-FTIR, SEM, TEM and XPS. Furthermore, the electrochemical performance of the materials was tested by cyclic voltammetry, step potential electrochemical spectroscopy, electrochemical impedance spectroscopy and charge-discharge curves at different current rates in 1 M KOH. These techniques were applied in order to understand the double layer and pseudocapacitive mechanism of K ion storage. The material formed in presence of graphene oxide exhibited the best electrochemical behavior, maintaining almost constant its initial capacitance after 500 cycles at 1 A g-1.

Chapter 9 - WITHDRAWN: Challenges in seismology

This book has been withdrawn.

Optimal Operation Strategy of Multi-Energy Complementary Distributed CCHP System and its Application on Commercial Building

For distributed energy system, multi-energy sources and their comprehensive utilization are popularly concerned nowadays. In this paper, optimal operation of a multi-energy complementary distributed combined cooling, heating and power (CCHP) system is deeply studied. This system is applied on a commercial building in Beijing and it has complex configuration including natural gas energy source, renewable energy source and different energy conversion devices. Meanwhile, a separated cooling, heating and power (SCHP) supply system is also proposed. Their optimal operation strategies and performance are compared to show the advantages of multi-energy complementary system. Through simulation, the results show that the multi-energy complementary system operates with great performance and the optimal operation strategy is effective.

Leidenfrost evaporation of a single droplet of gasoline blends of ethanol

The increase in energy consumption is observed since the middle of the 20th century. At the same time, the International Energy Agency (IEA) forecasts a 50% increase in energy consumption by 2030. One of the ways to reduce the consumption of such fuels are small additions received from natural gas and renewable energy sources. Mixtures of alcohols with gasoline and diesel oil are produced. Their small additions allow for a certain share of energy from renewable sources without a noticeable change in the combustion characteristics of such fuels. The paper presents the studies on the evaporation of drops of gasoline with a total composition CnHn+2, where n = 5 to 7. Its components are distillation products of crude oil with a low flash point. It is a colourless liquid mixture which main components are: n-heptane, neohexane and cyclopentane. The evaporation characteristics of such a drop with the addition of ethanol are also given. The result of the conducted research is the loss of mass during the drop carried above the surface with temperature above the Leidefrost point.

ПЕРСПЕКТИВЫ ИСПОЛЬЗОВАНИЯ ПРИРОДНЫХ ИСТОЧНИКОВ ЭНЕРГИИ ДЛЯ ТЕПЛОСНАБЖЕНИЯ УГОЛЬНЫХ ШАХТ

ПЕРСПЕКТИВЫ ИСПОЛЬЗОВАНИЯ ПРИРОДНЫХ ИСТОЧНИКОВ ЭНЕРГИИ ДЛЯ ТЕПЛОСНАБЖЕНИЯ УГОЛЬНЫХ ШАХТ

Studi Ekologis Dalam Perencanaan Rumah Tinggal Di Nganjuk

To accommodate the daily activities of a small family, efforts are needed to present are presentative residence. harmony with nature, humans, and the built-in environment, sustainably and sustainably is the Start Point. The ‘Ecological Architecture’ approach in planning the Residence in Nganjuk is chosen as the guiding line. The basic thing is whether there is an alignment between the architectural concept and the end result of his work. This research methodology uses descriptive and literature studies. this research attempts to analyze the design work with the concept of ecological architecture, based on the theory of ecological architecture from (Heinz Frick., 2006). The results of this study indicate that this Residence is a small example of the application of ‘Ecological Architecture’.The parameters can be seen from Adjusting design work to the environment, maintaining environmental resources, saving natural energy sources, utilizing natural resources around the area for building systems, both related to building materials and for building utilities. Implement 4R (reduce, reuse, recycle, repair) on the material used. the type of material that can be returned to nature in accordance with the cycle. with a building orientation pattern (east-west) to dominant vista facing north-south to become the center of sensing into the interior layout along with the parks and water spots. DOI: https://doi.org/10.26905/lw.v10i2.2683

Broadcast network model of pulsars as beacons of extraterrestrial civilizations

AbstractAccording to the Kardashev scale, likely extraterrestrial civilizations above Type-I might use natural energy sources of the Universe, which is also true for transmitting their signals out to distances. A variety of studies have shown that radio pulsars are most likely candidates for this. First, the current study examined how the radio beams of pulsars scan across their environment. Later when the radio beams of pulsars have been modulated, a network model has been proposed on how many habitable planets possible to be home for other assumed advanced civilizations could be reached. It has been found that size of each pulsar's broadcast network depends on the inclination angle. If a civilization controls multiple pulsars, it could comb a considerable fraction of their own celestial sphere and pulsars share their signals in a decentralized fashion as in the mail servers. Moreover, it is briefly cited how beam-modulating mechanisms can be built and searched around pulsars.Highlights • It has been shown how pulsars would behave like beacons only when they have been used by modulating their radio signals.• It has also been indicated how each pulsar could constitute an increasingly growing broadcast network by sweeping geometries and in what way it would emerge as number of controlled pulsars increases.• It has been interpreted how a modulation mechanism could be established and searched under basic physical principles.

Concentration Flow Cells Based on Chloride-Ion Extraction and Insertion with Metal Chloride Electrodes for Efficient Salinity Gradient Energy Harvest

Salinity gradient (SG) is a natural and renewable energy source existing in estuaries, and can also be produced during various desalination and industrial processes. Here, a new method is proposed to efficiently recover SG energy based on chloride-ion (Cl–) extraction and insertion with metal chloride electrodes and the Donnan potential over a cation-exchange membrane in a concentration flow cell. Three different metal chloride electrodes (BiCl3, CoCl2, and VCl3) were investigated in the cell, and their properties after discharging in 30 g L–1 (seawater) and 1 g L–1 (river water) NaCl solutions were studied by cyclic voltammetry, electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy. The cell with BiCl3 electrodes yielded the largest power density (max. = 3.17 W m–2) compared to that of CoCl2 and VCl3 electrodes, which was higher than those of most previous technologies for SG energy recovery. Fast Cl– extraction and insertion processes were observed on BiCl3 electrodes due to small charge transfer resistance and Cl– diffusion resistance. BiCl3 was reduced to metal Bi as Cl– released from the electrode to river water, while metal Bi was oxidized to BiCl3 as Cl– inserted into the electrode from seawater.

Radioactive waste stranded as U.S. shifts from nuclear energy

The U.S. appears to be witnessing the slow death of nuclear power. Plants are aging out and retiring, and their place in the electricity marketplace is being captured by cheaper, simpler, and less controversial sources—particularly natural gas plants and renewable energy sources such as wind and solar. But even as reactors shut down and communities eye former nuclear sites for redevelopment, a big problem remains: Despite more than 50 years of laws, regulations, lawsuits, and debates, the U.S. has no long-term repository for nuclear waste—nor even much of a plan for one. A decade ago, more than 120 reactors generated electricity in the U.S., and the nuclear power industry and federal regulators were heralding a nuclear power renaissance. Today, however, operating reactors have dropped to 98. Twelve more reactors have committed to shutting down by 2024, according to the U.S. Nuclear Regulatory Commission (NRC), which regulates nuclear power generators. The

Evaluation of Diverse Values of Hydropower

Japan is suitable for hydropower generation because of its varying topology and abundant water resources. The use of natural energy resources has recently gained importance in Japan, and as such the subject of small- and medium-scale hydropower generation has drawn much attention. However, new developments have not advanced significantly. Hydropower has various advantages over other natural energy sources; it provides stable power output, and if construction and maintenance are implemented appropriately, it can provide electricity at low costs and over long timescales. Further, hydropower is environmentally friendly, and can protect and improve the environment when implemented in harmony with natural and social factors. Moreover, it has social benefits; it contributes to aspects such as regional revitalization, local attractiveness, and disaster prevention. The possibilities of hydropower are not fully understood, and methods have not yet been established for its comprehensive practical utilization. Hydropower in Japan has not been in full-scale development for a while. Therefore, there are currently only a few experts on hydropower development. Accordingly, technologies and institutions for the development of small- and medium-scale hydropower generation while ensuring harmony with the natural and social environment are required. Further, a system is also needed to allow experts to promote and support such technologies and institutions in a cross-sectional way.

A Combined Renewable Energy System Demonstration for Providing the Energy Need at Esentepe (Windhill) Campus in Sakarya University

Energy need of the world is directly increasing with population and technology. Limited traditional sources like fossil fuel are not sustainable and usage of these sources causes harmful conditions for environment. The continuous and increasing energy usage must be provided from the continuous, natural and renewable energy sources instead of traditional sources. Wind and solar energy applications are important types of renewable energy class with features like being clean and environmentally friendly. Because of these remarkable features, these renewable energy sources are preferred and used all over the world. In Turkey, an outstanding increase has taken place in installed power during last 10 years. In this study, the electricity requirement of a building on the campus of Sakarya University is aimed to be compensated with a combined solar/wind energy system. First, the amount of energy consumption of selected building in a year was evaluated. The required parameters for wind energy like wind speed were provided from the Ministry of Energy and Natural Resources page. And, solar energy parameters were taken from Institute for Energy and Transport (IET) established by European Commission. The calculations were made by using these parameters and return of the investment was determined.

AQUIFER THERMAL ENERGY STORAGE SYSTEMS: BASIC CONCEPTS AND GENERAL DESIGN METHODS

Renewable energy plays an important role in meeting the ever increasing energy demand of the modern world. At this point, underground thermal energy storage has been suggested as a clean and efficient alternative of energy extraction for the sustainable future as one of the renewable energy varieties. Thermal energy storage systems in the aquifers have preluded the energy market with great success in many countries. Hot and cold natural energy sources are stored in the aquifer by using underground water to store the heat in this system. Efficiency of the system depends on several factors including groundwater temperatures and flow characteristics. Among the different underground thermal energy storage options, one of the most promising and commercial option is known as aquifer thermal energy storage (ATES). Based on the recent developments reported in the literature, general design procedures and construction techniques as well as relationships related with the efficiency of ATES systems are reviewed within the scope of this paper. The applications from the world and Turkey were discussed in a comparative approach.

Energy use analysis in the presence of quality of life, poverty, health, and carbon dioxide emissions

Access to clean energy has a positive impact on societies, whereas excessive extraction of fossil fuels along with population growth, traps the world into serious problems. Global energy strategy is a manner to find a balance between positive and negative impacts of energy on societies, especially their quality of life. This paper proposes a framework to choose a decent global energy strategy in the presence of five factors including final energy consumption, quality of life, poverty, health, and carbon dioxide emissions. The core of the framework is “Trade-off Analysis”, which its outputs are analyzed by three defined scenarios in the presence of total population. According to the results, mitigation of carbon dioxide emissions and preservation of the natural energy sources are two factors with a higher priority to encourage developed countries to reduce energy consumption. In case of developing countries, in addition to the two previous factors, the poverty and quality of life are next priorities. For pre-developing countries, the first priority is poverty reduction, then health and quality of life improvement. Thereby, the paper proposes the eco-sufficiency and eco-efficiency policies for developed and developing countries respectively, while energy poverty policy for pre-developing countries.

An Analysis of India's Trade Intensity with UAE

Today no nation in the world is fully self-reliant on its own resources. All the nations of the world are somehow interdependent on others, because every nation has its own natural resources, climate, geographical conditions and sources of energy. International interdependence is the main feature of today's global economy. Trading links between India and UAE have existed since ancient times. Indo-UAE trade has grown enormously in recent years. Many statistical trade indices are available to measure trade between two countries. One of them is the trade intensity index. The trade intensity index appears in two forms, the export intensity index and import intensity index. A few studies have done to explore intricacies of the trade relationship between the two countries. Under such scenario this paper investigates the major trends of bilateral trade and explores issues associated with trade intensity. An attempt is made here to examine the India's Trade Intensity with UAE for the period from 2006 to 2016. The paper also suggests measures to enhance trade intensity between India and UAE. Time series data have been used to measure Trade Intensity Index (TII). The findings of the study reveal that India's trade with UAE is more intense in comparison with its other trading partners.

Connectivity Analysis in Clustered Wireless Sensor Networks Powered by Solar Energy

Emerging 5G communication paradigms, such as machine-type communication, have triggered an explosion in ad-hoc applications that require connectivity among the nodes of wireless networks. Ensuring a reliable network operation under fading conditions is not straightforward, as the transmission schemes and the network topology, i.e., uniform or clustered deployments, affect the performance and should be taken into account. Moreover, as the number of nodes increases, exploiting natural energy sources and wireless energy harvesting (WEH) could be the key to the elimination of maintenance costs while also boosting immensely the network lifetime. In this way, zero-energy wireless-powered sensor networks (WPSNs) could be achieved, if all components are powered by green sources. Hence, designing accurate mathematical models that capture the network behavior under these circumstances is necessary to provide a deeper comprehension of such networks. In this paper, we provide an analytical model for the connectivity in a large-scale zero-energy clustered WPSN under two common transmission schemes, namely, unicast and broadcast. The sensors are WEH-enabled, while the network components are solar-powered and employ a novel energy allocation algorithm. In our results, we evaluate the tradeoffs among the various scenarios via extensive simulations and identify the conditions that yield a fully connected zero-energy WPSN.

استخدام التقنیات الحدیثة فی تطویر الإضاءة الطبیعیة بالفراغات الداخلیة

The designer recognizes the effective role of environmental elements - especially natural lighting - in reaching a successful design that achieves the best performance. Natural lighting goes to the core of the architect's thinking; it could also inspire Architects different forms of spaces, colors and textures. There are many modern styles that help the architect to make his own decisions for design of building and how to take advantage of natural light inside buildings. These styles aim to increase certain consideration of the environment and propose different improvements in ecosystems such as thermal insulation, exploitation of natural energy sources and attention to natural lighting systems and building materials. Many Changes had been made to the external openings, to achieve better performance of the quality of glass and to increase the transmission of the light level with the efficiency of protection from solar radiation. There are many solutions that provide different levels of natural lighting. Hence the role of research in showing some of these modern styles and its role in helping to reach the suitable environmental design for natural lighting

Hybridized nanogenerator based on honeycomb-like three electrodes for efficient ocean wave energy harvesting

Ocean energy is one of the most promising clean and renewable natural energy sources, however, owing to traditional energy harvesting technology, the collection and utilization of ocean energy is extremely limited. In this work, a hybridized ocean wave nanogenerator (How-NG) based on honeycomb-like three electrodes has been proposed, which consists of a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG), where the TENG works in both in-plane sliding mode and vertical contact-separation mode. With innovative design in electrode structure and hybrid of TENG and EMG, the How-NG can harvest two types of wave energy, kinetic energy and potential energy of ocean surface wave. The honeycomb-like three electrode structure is designed to harvest wave energy in multi-angle range for random waves. In addition, by adjusting the weight of the magnet to achieve different resonance parameters, the How-NG could reach a resonant state and more efficient collection of ocean energy. Furthermore, the influence of the working frequency and sliding displacement on the electrical outputs of the TENG unit and EMG unit are investigated systematically. The maximum output energy of TENG and maximum power of EMG can reach 21.7 µJ and 8.23 µW respectively at fixed working frequency of 4.0 Hz and sliding displacement of 3.5 cm. In addition, those two basic units are assembled vertically into a sealed cylinder acrylic shell which is used to drive LEDs by harvesting the water wave energy. This work presents a novel and efficient approach toward large-scale blue energy harvesting from the ocean.