Self-sustaining System Research Articles

Solar-pond assisted reverse osmosis-electrodialysis system for seawater desalination and hydroponic fertilizer solution production

ABSTRACT A thermodynamic analysis is performed on a solar-pond assisted reverse osmosis-electrodialysis system to produce freshwater and a hydroponic fertilizer solution for sustainable desalination and waste recovery. The reverse osmosis unit desalinates seawater to produce freshwater and a waste concentrated salt solution rich in many useful ions and minerals. The reverse osmosis unit’s waste stream is sent to an electrodialysis unit that utilizes monovalent membranes to reject magnesium, calcium and sulfate ions. These ions are beneficial for plant growth and the product can be used as a hydroponic fertilizer solution for agricultural purposes. A solar pond is integrated into the system to reduce the power requirements. The solar pond utilizes energy from the sun to store thermal energy in a large body of concentrated salt water with temperatures up to 90°C in the lower convecting zone. This thermal energy is utilized in an organic Rankine cycle with the working fluid R113 to create a self-sustaining desalination and waste treatment system running on solar energy. The system produces about 4.52 kg/s of freshwater and 4.75 kg/s of hydroponic solution. The overall energy and exergy efficiencies of the integrated system are found to be 20.36% and 2.55%, respectively.

Povećanje učešća obnovljivih izvora energije u sistemima za daljinsko grejanje

This paper presents and elaborates the proposal for reorganization of district heating sector in the Republic of Serbia, in order to increase its efficiency, as well as the proposal for the introduction of a self-sustaining incentives system for investments in infrastructure and thermal systems using renewable energy sources (RES). The goal is to reduce the use of non-renewable energy sources, in order to mitigate environmental pollution, as well as to decrease the share of electricity used for space heating. That way, also the electric power system (EPS) would be relaxed and the degree of primary energy utilization would be increased, by avoiding its conversion into electric and then back into thermal energy. As a comparative example of the applicability of the reorganization proposal, the paper presents experiences from the process of reorganization of the electricity sector in the Republic of Serbia. Within the presented proposal of the incentives system, descriptions of the methods necessary for the establishment of such a system are given, too. Acceptance and implementation of these proposals would contribute to increasing the participation of RES in district heating systems and result in achieving the aforementioned, positive effects of wider social impact and significance.

A Broadband Dual-Polarized Solar Cell Phased Array Antenna

This study proposes a broadband dual-polarized solar cell phased array antenna. It is constructed by using crisscross distributed metal-meshed tie-shaped dipoles, an optical transparent glass substrate, feeding probes and ground probes, a solar cell, and a metal ground. The meshed tie-shaped dipoles are sputtered on the top surface of the glass substrate. Circular metal-meshed patches located at the crisscrossing points of the dipoles on the back surface of the glass substrate are introduced to extend the operational bandwidth of the solar cell antenna. The solar cell was placed on the ground of the antenna. We fabricated a sample of the solar cell antenna and measured the electromagnetic characteristics and its power output. The results of the measurements agreed with those of simulations. The proposed solar cell antenna array had a wide operational bandwidth of 2.5–5 GHz, a wide 2-D range of the phase scanning angle of ±45°, a high aperture efficiency of 68.9%–84.1%, and a high relative maximum output power ratio of 87.1% compared with a pure solar cell. It is scalable and can be used in a self-sustained 5G wireless communication system for sub-6 GHz applications.

Applying Compute-Proximal Energy Harvesting to Develop Self-Sustained Systems for Automobiles

A major cost, inconvenience, and source of failure for adding sensors and electronic accessories to automobiles is wiring the systems into the car’s power supply. We propose an alternative approach, computer-proximal energy harvesting, which harvests power locally, so wiring is not needed. In this article, we provide an overview of the principles and empirical evaluations for harvesting energy in and around the automobile exploring the role that wind, light, vibration, and heat can play in this process. To better explore these concepts, we demonstrate two prototypes—A thermoelectric energy-based parking assistant, which is attached to the exhaust pipe, and a wind-powered external pedestrian display, which is anchored to the front bumper of a car.

Domestic quarantine: An introspection and future perspectives on biosecurity interventions to contain pathogen spread in vegetatively propagated spices in India

Safeguarding biodiversity poses a major challenge that warrants preventive legislative and regulatory frameworks to ensure biosecurity, preserve intrinsic biodiversity and mitigate risks from the invasion of exotic pathogenic microbes thereby sustaining agricultural productivity and food safety. The anthropogenic activities contribute enormously towards transboundary movement of invasive alien pathogens through trade and transport of seeds/propagation materials that need to be regulated by enacting appropriate laws and policy guidelines. Black pepper, cardamom, ginger, turmeric and vanilla are the major vegetatively propagated spices cultivated in India. Since primary spread of the major pathogens in these spices are mediated through planting materials, it is imperative to formulate guidelines for flawless and meticulous implementation of quarantine measures which are otherwise not adopted. This review discusses the significance of domestic quarantine in major vegetatively propagated spices with a comprehensive background on plant biosecurity and invasive plant pathogens which could pose threat to spice cultivation in India. It further illustrates the constraints and possible strategies to annihilate the cryptically disseminated pathogens through vegetative planting materials ultimately to safeguard our self-sustaining agricultural systems.

A Self-Sustained System Spanning the Primary and Secondary Metabolism Stages to Boost the Productivity of Streptomyces.

Streptomyces species possess strong secondary metabolism, the switches of which from the primary metabolism are complex and thus a challenge to holistically optimize their productivities. To avoid the complex switches and to reduce the limitations of different metabolic stages on the synthesis of metabolites, we designed a Streptomyces self-sustained system (StSS) that contains two functional modules, the primary metabolism module (PM) and the secondary metabolism module (SM). The PM includes endogenous housekeeping sigma factor σhrdB and σhrdB-dependent promoters, which are used to express target genes in the primary metabolism phase. SM consists of the expression cassette of σhrdB under the control of a secondary metabolism promoter, which maintains continuous activity of the σhrdB-dependent promoters in the secondary metabolism phase. As a proof-of-principle, the StSS was used to boost the production of some non-toxic metabolites, including indigoidine, undecylprodigiosin (UDP), ergothioneine, and avermectin, in Streptomyces. All these metabolites can undergo a continuous production process spanning the primary and secondary metabolism stages instead of being limited to a specific stage. Scale-up of UDP fermentation in a 4 L fermentor indicated that the StSS is a stable and robust system, the titer of which was enhanced to 1.1 g/L, the highest at present. This study demonstrated that the StSS is a simple but powerful strategy to rationally engineer Streptomyces cell factories for the efficient production of non-toxic metabolites via reconstructing the relationships between primary and secondary metabolism.

Self-sustained bioelectrical reduction system assisted iron–manganese doped metal-organic framework membrane for the treatment of electroplating wastewater

Heavy metals seriously endanger human health. However, simultaneous and efficient removal of heavy metals from wastewater has always been a technical challenge. For this purpose, we developed a self-sustained bioelectrical reduction system (SBRS) for the efficient purification of heavy metal wastewater. A novel iron-manganese doped metal-organic framework membrane (FM-MOFM) based on conductive substrate is used as the catalytic cathode electrode. The performances of the SBRS assisted FM-MOFM for heavy metals reduction and self-energy generation for the treatment of simulated electroplating wastewater were investigated. The FM-MOFMs were characterized before and after operation by SEM, XRD, XPS and other methods. Copper, zinc, chromium, nickel heavy metal ions are almost completely removed by the SBRS (removal efficiency: Copper ion 99.9%, Zinc ion 99.9%, Chromium ion 99.7% and Nickel ion 99.8%). Moreover, the organic substrates in the wastewater were removed simultaneously and efficiently (removal efficiency: COD 95.3%, NH4+-N 99.9%, TP 95.9%), with the maximum power density of 1.6 W m−3. The possible electroreduction and electroflocculation mechanism of heavy metal ions can be understood by the characterization of the membrane electrode surface and precipitate. The study confirms that the SBRS is a potential and efficient candidate for the simultaneous removal of heavy metals from electroplating wastewater.

Exact dynamics of phase transitions in oscillator populations with nonlinear coupling

The Kuramoto model consisting of a population of coupled phase oscillators has served as an idealized tool for studying synchronization transitions in diverse self-sustained systems. It has been a common brief that the model exhibits a first-order discontinuous (hybrid) phase transition towards synchrony with the absence of partial locking by assuming that the natural frequencies are uniformly distributed. In this paper, we consider a variant of this model by modifying its global coupling to depend on a power law function of the macroscopic order parameter of the population via an exponent α. The generalization retains the uniform coupling and mean-field character of the system, where there is an interplay between the coupling and oscillator dynamics. Surprisingly, we show that the partial locking with the coexistence of the phase locked and drifting populations indeed exists for α<1, whereas it can never occur as long as α≥1. Through a remarkable ansatz of the frequency-dependent version of Ott–Antonsen manifold, we reveal that the long term macroscopic dynamics of the resulting model, as well as their corresponding critical properties can be analytically described. More importantly, we construct the characteristic function to give intuitive interpretations of a variety of dynamical phenomena occurring in the system, such as the emergence of the partial locking, vanishing synchronization onset, and the irreversibly abrupt desynchronization transition.

A facile and sustainable hygroelectric generator using whole-cell Geobacter sulfurreducens

Hygroelectric generator (HEG) technology based on ambient humidity is a promising self-sustained energy harvesting system, but it usually suffers from the disadvantages of expensive materials, complicated device construction processes, and unfavorable short-term power output. Herein, we propose a facile whole-cell HEG, which was fabricated from an easily prepared film of whole-cell Geobacter sulfurreducens (G.S.) and a low-cost indium tin oxide electrode. The HEG produced an open-circuit voltage of 0.3 V and a load current of 0.3 μA with a power density of 2.5 μW/cm2 that lasted for longer than 2160 h. The performance of HEGs constructed from G.S. nanowires (NWs), whole-cell G.S., and G.S.-without NWs was compared, which indicated that the energy harvesting behavior of the HEG was highly dependent on surface hydrophilicity and the ionization level, as determined by the content of hydrophilic groups in the film. Our results demonstrate a facile and inexpensive whole-cell HEG technology that generates sustainable hygroelectricity from ambient humidity. This development will greatly promote the practical application of hygroelectricity technology.

A novel approach to control the Jointed Arm Robot by tracking the position of the moving object on a conveyor using an Integrated Computer Vision system

Computer vision algorithms play a vital role in developing self-sustained autonomous systems. The objective of the present work is to integrate the robotic system with a moving conveyor using a single camera by adopting a Gaussian Mixture Model (GMM) based background subtraction method. In this work, a simple web camera is placed above the work cell to capture the continuous images of the moving objects on the conveyor along with a jointed arm robot are connected to a microcontroller through the computer. The position of the object with time and its features are extracted from the captured image frames by subtracting its background using the Gaussian Mixture Model (GMM). The output images of GMM are further processed by image processing techniques to extract the features like shape, color, center coordinates. The extracted coordinates of objects of interest are used as input parameters to the controller to activate the base rotation of a joint arm robot to perform different manipulations. The developed algorithm is evaluated on an indigenously fabricated work cell integrated with a computer vision setup.

Self-sustainable flow-velocity detection via electromagnetic/triboelectric hybrid generator aiming at IoT-based environment monitoring

Harvesting energy from the environment has aroused widespread interest and it can supply renewable power to achieve sustainable environment monitoring for the Internet of things (IoT). In this paper, a tri-cylinder-like hybrid generator composed of triboelectric nanogenerator (TENG) and electromagnetic generator (EMG) is presented to harvest the mechanical energy produced by various fluids as well as sense the real-time flow velocity ecofriendly. This generator can be driven to rotate through a windmill or waterwheel, leading to the reciprocating sliding of the internal spring-magnet structure. By arranging coil and foldable TENG structure, it can generate hybrid signals along with the rotation while gear pairs are further utilized for both boosting the output and expanding the sensing range. The experimental result shows more than twice and six times output can be realized by gear pairs for TENG and EMG, respectively, and the recognizable rotational frequency reaches 10 Hz with a transmission ratio of 5:1. The rotation speed and direction detection are realized based on the output voltage frequency and value of TENG caused by the difference of triboelectric layer number. Combined with two hybrid generators in a vertical layout, the wind directions are also investigated to be distinguished by computing the signal characteristics. Based on these sensing mechanisms, this hybrid generator is able to achieve wireless sensing as EMG boosted by gear pairs is sufficient to supply the energy for wireless transmission. This self-sustained sensory system shows its great potential for unmanned environment monitoring, disaster warning as well as the meteorological record in IoT applications.

What is a deliberative system? A tale of two ontologies

Deliberative systems theorists have not explained what a deliberative system is. There are two problems here for deliberative systems theory: an empirical problem of boundaries (how to delineate the content of a deliberative system) and a normative problem of evaluation (how to evaluate the deliberation within a deliberative system). We argue that an adequate response to these problems requires a clear ontology. The existing literature suggests two coherent but mutually exclusive ontologies. A functionalist ontology postulates self-sustaining deliberative systems with their own functional goals and logics independent of human intentionality. In contrast, an interpretive ontology conceives of deliberative systems as the products of the beliefs and actions of the actors in the relevant practices—deliberative systems derive from human intentionality. We conclude by showing how these conflicting ontologies lead to different empirical and normative agendas.

General Aspects, Islanding Detection, and Energy Management in Microgrids: A Review

Distributed generators (DGs) have emerged as an advanced technology for satisfying growing energy demands and significantly mitigating the pollution caused by emissions. Microgrids (MGs) are attractive energy systems because they offer the reliable integration of DGs into the utility grid. An MG-based approach uses a self-sustained system that can operate in a grid-tied mode under normal conditions, as well as in an islanded mode when grid disturbance occurs. Islanding detection is essential; islanding may injure utility operators and disturb electricity generation and supply because of unsynchronized re-closure. In MGs, an energy management system (EMS) is essential for the optimal use of DGs in intelligent, sustainable, reliable, and integrated ways. In this comprehensive review, the classification of different operating modes of MGs, islanding detection techniques (IDTs), and EMSs are presented and discussed. This review shows that the existing IDTs and EMSs can be used when operating MGs. However, further development of IDTs and EMSs is still required to achieve more reliable operation and cost-effective energy management of MGs in the future. This review also highlights various MG challenges and recommendations for the operation of MGs, which will enhance the cost, efficiency, and reliability of MG operation for next-generation smart grid applications.

The Vertical Greenery Systems Significant Role in Achieving Better Architectural and Urban Thermal Performance. (Dept. A)

Vertical Greenery Systems (VGS) are self-sustaining garden systems that can be designed on the building envelope, they represent an innovative approach to rebalance the urban heat island phenomena that have become a major problem in recent times, resulting from urbanization and activities polluting the environment, especially in cities and urban with high density. These systems are becoming common and require further knowledge about their particular impacts on the building and the environment. In recent decades, various studies have been conducted to demonstrate that these systems can contribute to improving the urban environment and enhancing buildings' efficiency, though thermal research remains the most predominant subject compared to others. The latest technology of VGS systems reflects a sustainable approach to urban improvement and retrofitting buildings. Green infrastructure research is advancing regularly, recognizing aesthetic enhancements as well as ecological, economical, and social benefits. A board overview of vertical greenery systems and a thorough analysis of the basic advantages of these green infrastructures are presented in the paper. The purpose of this study is to investigate the influence of vertical greenery systems on the thermal building performance in the hot climate and to apply new methods to improve its efficiency. The paper discusses numerous VGS implementation case studies, reviewing the challenges and limitations of the usage of VGS in Egypt and the MENA region. Finally, proposing various guidelines for use of vertical gardens as an advanced technology for a sustainable urban approach.

Long COVID-19 Syndrome: A Comprehensive Review of Its Effect on Various Organ Systems and Recommendation on Rehabilitation Plans.

The majority of people infected with SARS-CoV-2 fully recovered within a few weeks. However, a considerable number of patients of different ages still suffer from long-lasting problems similar to the multi-organ damage in its acute phase of infection, or experience symptoms continuously for a longer term after the recovery. The severity of the primary infection seems not to be associated with the possibility and severity of long-term symptoms. Various unresolved symptoms have been reported in COVID-19 survivors months after hospital discharge. Long COVID-19 Syndrome refers to survivors 4 months after initial symptoms onset. It is important to understand the systemic effects of Long COVID-19 Syndrome, its presentations, and the need for rehabilitations to restore functional recovery in survivors. Government, healthcare workers, and survivor groups should collaborate to establish a self-sustaining system to facilitate follow-up and rehabilitations, with prioritization of resources to more severely Long COVID-19 Syndrome survivors. This review looks into the systemic effects of Long COVID-19 Syndrome in various aspects: respiratory, cardiovascular, hematological, renal, gastrointestinal, neurological, and metabolic effects of Long COVID-19 Syndromes. Recommendations for follow-up and rehabilitations details have been explored to cope with the tremendous Long COVID-19 Syndrome patients.

The Role of Geometry on a Self-Sustaining Bio-Receptive Concrete Panel for Facade Application

Bio-receptivity refers to the aptitude of a material to allow for the natural growth of small plant species on stony surfaces with minimum external influence. Despite the numerous associated environmental benefits, the growth of mosses and lichens on facades has always been viewed as a negative phenomenon due to the random and shabby growth conditions. This research dealt with the design of a self-sustaining bio-receptive concrete facade system with an aim to create a more sustainable and green concrete for the construction industry. The research used surface geometry as a design variable to facilitate moss growth on concrete panels in an ordered and systematic manner. The exercise was an attempt to not only address the functional aspect of bio-receptivity but also its aesthetical quality, which has a primary influence on people’s perception of bio-receptivity and can promote mass use of this type of concrete material. The research was conducted in a top-down approach, where first, through design by research, six distinctly designed concrete panels were fabricated using adapted material composition (blast furnace cement with 75% slag, 0.6 water/cement, sand 0–4 mm and gravel 5–8 mm) as the boundary condition. The concrete mixture together with no curing policy resulted in highly porous concrete panels, suitable for bio-receptive properties. Next in the design validation phase, the influence of surface geometry/roughness on the water retention ability of the panels and the subsequent moss growth on the panels were evaluated through in vitro experiments. The water retention experiment of the panels was based on quantitative measurements for weight, relative humidity and temperature at several time intervals. The moss-growing experiment was carried out within an ideal greenhouse condition where the panels were initially inoculated with moss spores; the results were based on qualitative observation for a period of 4 months. According to the comparative analysis of these results, with the same material composition, Panel 2 showed the highest bio-colonization owing to its prominent surface geometry, whereas Panel 5 showed the least bio-colonization owing to its plain surface despite high absorption capacity. Thus, the role of geometry has been extensively proven in this research and as an outcome a set of general design guidelines have been formulated for a self-sustaining bio-receptive concrete facade panel, using geometry as a design variable for bio-receptivity.

Dynamics and control of a thermally self-sustaining energy storage system using integrated solid oxide cells for an islanded building

A solid oxide cell-based energy system is proposed for a solar-powered stand-alone building. The system is comprised of a 5 kWel solid oxide fuel cell (SOFC), a 9.5 kWel solid oxide electrolysis cell (SOEC), and the required balance of plant. The SOFC supplies: 1- building demand in the absence of sufficient solar power, 2- heat for SOEC in endothermic and standby modes. Thermal integration of SOFC and SOEC is implemented through a network of heat exchangers, combined with set of control algorithms. Two control strategies were implemented to actuate the SOFC in response to endothermic heat demands of SOEC by manipulating: 1- electric power, 2- fuel utilization. The results of dynamic simulation of system for two scenarios (sunny day and cloudy day) showed successful compliance of temperature constraints with both methods. Manipulation of fuel utilization, however, resulted in better system performance in terms of efficiency and H2 balance.

Exact solutions of the abrupt synchronization transitions and extensive multistability in globally coupled phase oscillator populations

The Kuramoto model consisting of large ensembles of globally coupled phase oscillators serves as a paradigm for modelling synchronization and collective behavior in diverse self-sustained systems. As interest in the effects of higher-order interactions, we study an extension of the Kuramoto model with higher-order structure by considering the correlations between frequency and coupling. The resulting model is exactly solvable and several novel dynamical phenomena including clustering, multistability, and abrupt synchronization (desynchronization) transition emerge. We demonstrate that the extensive multiclusters corresponding to different arrangements of oscillator populations on the circle are established in a universal way that are independent of the choices of frequency distributions (heterogeneity of the ensembles). Using the partial dimensionality reduction of the Ott–Antonsen, we present a rigorous analysis of various multi-cluster states by studying their spectrum in the thermodynamic limit. In particular, we prove that a large multiplicity of the synchronous states are asymptotically stable to perturbation in the tangent space, thereby determining an explicit stability condition for their occurrences in the high-dimensional phase space.

Establishing communicable disease surveillance systems

Humanitarian emergencies can result in an increase of communicable diseases, leading to a rise in mortality and/or morbidity in vulnerable populations. This requires a public health approach to re-establish control...

Mitochondria Encapsulation in Hydrogel-Based Artificial Cells as ATP Producing Subunits.

Artificial cells (ACs) aim to mimic selected structural and functional features of mammalian cells. In this context, energy generation is an important challenge to be addressed when self-sustained systems are desired. Here, mitochondria isolated from HepG2 cells are employed as natural subunits that facilitate chemically driven adenosine triphosphate (ATP) synthesis. The successful mitochondria isolation is confirmed by monitoring the preserved inner membrane potential, the respiration, and the ATP production ability. The encapsulation of the isolated mitochondria in gelatin-based hydrogels results in similar initial ATP production compared to mitochondria in solution with a sustained ATP production over 24 h. Furthermore, luciferase is coencapsulated with the mitochondria in gelatin-based particles to create ACs and employ the in situ produced ATP to drive the catalytic conversion of d-luciferin. The coencapsulation of luciferase-loaded liposomes with mitochondria in gelatin-based hydrogels is additionally explored where the encapsulation of mitochondria and liposomes resulted in clustering effects that are likely contributing to the functional performance of the active entities. Taken together, mitochondria show potential in cell mimicry to facilitate energy-dependent processes.