Economical Solution Research Articles

Critical measurement parameters estimation in liquid rocket engine using LSTM-based soft sensor

Liquid Rocket engines (LREs) need to be hot tested on the ground, in order to make them flight-worthy. Ground hot tests are critical, expensive, and involve considerable human efforts in acquiring the critical measurement parameters. Measurement sensors are prone to failure due to the hazardous propellant environment and are vulnerable to noise (internal and external) during the LRE ground hot tests. The usage of redundant sensors is not a viable solution for space applications due to cost, power, weight, and space constraints. Data-driven Soft Sensors (SS) are being used in different industrial processes. SS can provide an effective alternative and economical solution for space applications. The objective of the proposed work is to implement a suitable data-driven soft sensor for estimating three critical measurement parameters namely, turbine speed, chamber pressure (Pc), and propellant flow rate of LRE. Long Short-Term Memory (LSTM) networks are capable of learning order dependence in sequence prediction problems and are well-suited to make predictions based on time series data. As the selected LRE test data contain order dependence sequences, LSTM is well suited for the estimation of critical measurement parameters. LSTM-based soft sensor (LSTM-SS) was developed and trained using a large sample set of 59,80,000 data points collected over a period of 12 years of LRE ground hot tests. The maximum root mean square error (RMSE) of 6.06% was obtained for propellant flow-rate estimation, whereas the minimum RMSE of 0.22% for chamber pressure and RMSE of 0.87% for turbine speed were obtained. The obtained results show that the designed LSTM-SS has superior performance and better generalization for practical use.

A compact and economical AMC backed antenna solution for wearable biomedical applications

AbstractA rectangular monopole antenna with an extended ground, excited by Coplanar Waveguide (CPW) and backed by a 6 × 6 array of fractal artificial magnetic conductor (AMC) unit cells, resonating at 5.8 GHz in Industrial, Scientific, and Medical (ISM) band, is presented in this manuscript. To attain the objective of proposing a compact and economical antenna solution for employment in wearable biomedical domain, a novel approach of utilizing both surfaces of the same dielectric for engraving antenna element as well as AMC array is adopted. It results in the elimination of layers of expensive substrate (RO3003) and of thick separator (foam) between antenna and AMC array. During measurement in open space, the proposed antenna system exhibited an impedance bandwidth of 570 MHz with a gain of 7.9 dBi. While a total realized gain of 7.5 dBi, amounting to a gain enhancement of about 3 dB as compared to that of monopole alone, is observed when the integrated antenna system is placed just over a three-layer rectangular human body equivalent model. Specific absorption rate values, as calculated at 5.8 GHz and averaged over 1 and 10 g of human tissue, are 0.0117 and 0.00244 W/kg, respectively. Obtained results strongly advocate the use of the proposed antenna system in smart wearable healthcare devices.

Optimizing ecological and economic benefits in areas with complex land-use evolution based on spatial subdivisions

The increasing complexity of urban systems intensifies the ecological decline caused by disordered land-use patterns. However, inadequate recognition of complex land-use evolution and large-scale zoning management limits the performance of the classical planning paradigm. Furthermore, few studies have provided quantitative support for maintaining ecological benefits in land-use optimization. In this study, complex land-use evolution was quantitatively delineated and categorized by developing trends and evolutionary stages within subdivided units. Considering both ecological and economic benefits, flexible and practical solutions from multi-objective optimization are clustered and precisely matched to spatial units with diverse needs. The empirical results reveal that (1) the spatial pattern of land-use development trends exhibits a concentric ring structure in Xiamen, and its adaptive evolution stage is dominantly progressing from exploitation to conservation; (2) excessive pursuit of economic output (EO) of land-use leads to a reduction in ecological potential (EP) and ecological connectivity (EC), while a decline of EP and EC inversely reduces the marginal EO of construction land; and (3) large improvements in the EP of land use are observed in the development priority scenario while limited improvements in the EO of land use are observed in the conservation priority scenario. This approach can provide optimal area thresholds for different land-use types for decision-making that supports the planning and precise management of land uses. Additionally, the findings of this study provide important insights for sustainable urban land-use development.

Dust cycle, soiling effect and optimum cleaning schedule for PV modules in Iran: A long-term multi-criteria analysis

Mineral dust has a great effect on the performance of solar power plants not only by absorbing and scattering solar radiation, but also due to soiling effects. The aim of the present study is to investigate the characteristics of dust in Iran using the Modern-Era-Retrospective-Analysis for Research and Applications in 2000–2019. In this assessment, radiation effects, dust emission and deposition rate in Iran were investigated from the aspects of seasonal changes and trends. Then, the effect of soiling in a 100 MW power plant in a twenty-year period in different regions of Iran was investigated. Finally, 15 cleaning scenarios were examined from three technical, economic, and environmental perspectives, and the most appropriate scenario was selected in each region of Iran using the multi-criteria decision-making method (MCDM). The evaluation showed the most dust emission rate is occurred in the southwestern Iran. In addition, rainfall has only been able to reduce the soiling effects in the western part of Iran to some extent, but it cannot be a suitable economic solution to reduce this effect. With dust soiling effect, the Levelized cost of energy (LCOE) varies from 100 to 270$/MWh. However, cleaning can reduce LCOE to 50$/MWh and is vital solution to develop solar energy in dusty areas. The results of MCDM also showed that weekly and semi-weekly automatic cleaning are the most suitable periods in Iranian solar plants.

Municipal wastewater reclamation: Reclaimed water for hydrogen production by electrolysis – A case study

This paper presents an analysis of a treatment system selection for municipal wastewater stream based on the DuPont Water Solutions WAVE software. The results obtained based on an analysis of 7 different processing cases studies (ultrafiltration and reverse osmosis) confirmed that the application of 2-pass membrane systems enables the reclamation of water from municipal wastewater that fulfills the requirements concerning the quality of water intended as electrolyzer feedstock, as the obtained water exhibited a conductivity of < 5 µS/cm. Depending on the analyzed case study, the attainable level of water reclamation ranged from 68.8 to 84.1 % at an energy consumption of 606.1 – 2 694 kWh/d. The results of this work not only confirm that the selected processing solutions make it possible to reclaim water from municipal wastewater, but also confirm the necessity of using software to simulate the membrane system operation to select the most economic and cost-effective solution.

Hydrogeological spatial modelling: A comparison between frequentist and Bayesian statistics

Abstract Traditional and modern spatial prediction techniques are applied in the analysis of water quality, evidencing a new approach that allows the modeling of a hydrogeological system in the central area of Boyacá, Colombia. The objective is to determine the quality status of groundwater for human consumption. In the process, spatial predictions were made based on frequentist methods (kriging, cokriging) and Bayesian methods (R-INLA stochastic partial differential equation) as an alternative to Markov chain Monte Carlo methods that require a large computational cost. From the application of these methods, a comparison is made by statistical tests that determine the goodness of adjustment of the predictions. Our interest here is in the implementation of future more robust, economic and scientific solutions, particularly for hydrogeological data, and the proper management of water resources. Finally, the vulnerability of aquifers is analyzed with the DRASTIC method, which takes into account the surrounding media of the aquifers through the variables depth (D), net recharge (R), type of aquifer (A), soil (S), topography (T), impact of the vadose zone (I) and hydraulic conductivity (C).

Green engineered mulch for phosphorus and metal removal from stormwater runoff in bioretention systems

Phosphorus and metals in stormwater runoff are major causes of water quality degradation. Bioretention systems are increasingly implemented to improve stormwater quality and to better manage stormwater quantity. Many studies have focused on modifying the composition of the soil bed to improve pollutant removal. However, the pollutant removal performance of bioretention systems can diminish over time, such as when clogging of the media occurs. Sediment accumulation on the soil surface may inhibit infiltration into the soil bed, thus limiting pollutant removal. Soil replacement may be eventually required as pollutants accumulate in the soil. In this study, a green retrofit material, called green engineered mulch (GEM), was generated by coating regular wood mulch with aluminum-based water treatment residuals (WTR) via a simple and low-energy process (patent pending). The GEM was developed to serve as a green retrofit for bioretention systems to enhance the removal of phosphorus and metals from stormwater runoff. The GEM was placed in a rain garden in Secaucus, NJ, USA for 15 months, during which 12 storm events (ranging from 6.0 mm to 89.6 mm) were monitored. Runoff and infiltrate samples were analyzed for dissolved and total concentrations of phosphorus and metals, along with other key water quality parameters. The GEM significantly reduced (p < 0.05) the total concentrations of phosphorus and metals in stormwater infiltrate compared to the inlet, unlike the regular mulch. Minimal or no contact with the GEM resulted in no significant pollutant removal from surface runoff. No significant pollutant export from the GEM was observed. The spent GEM can be disposed of as non-hazardous waste in municipal landfills. This study demonstrates that the GEM is a safe and effective retrofit. Moreover, the GEM is a simple and economical retrofit solution that can be used in place of regular mulch in bioretention systems.

Ex situ bioremediation of diesel fuel-contaminated soil in two different climates

The petroleum industry is often faced with accidental spills and discharges that pollute valuable natural resources such as soil. The purpose of this study was to assess bioremediation potential of an on-site landfarming unit (LU), a highly economical solution that complies with the zero-waste policy, for bioremediation of the contaminated soil after an actual diesel fuel leakage in a fuel depot. The first aim was to evaluate the effects of different climates on hydrocarbon bioremediation. For this reason, a part of the contaminated soil was moved from the initial location with a sub-Mediterranean climate to an LU at another location with a temperate continental climate. Our results demonstrated that remediation in sub-Mediterranean climate is less effective than the remediation in a temperate continental climate. The second aim of this study was to evaluate the effect of different plant species on the microbial population during bioremediation. For that purpose, 365-day monitoring of phospholipid fatty acids (PLFA) was performed. Our results support the hypothesis that plant-assisted bioremediation can diminish toxic effects of diesel-polluted soil and that the changes in plant species during bioremediation cause changes in the microbial population.

Antimicrobial Nanoparticles Mediated Prevention and Control of Membrane Biofouling in Water and Wastewater Treatment: Current Trends and Future Perspectives.

Global water scarcity and water pollution necessitate wastewater reclamation for further use. As an alternative to conventional techniques, membrane technology is extensively used as an advanced method for water purification and wastewater treatment due to its selectivity, permeability, and efficient removal of pollutants. However, microbial biofouling is a major threat that deteriorates membrane performance and imparts operational challenges. It is a natural phenomenon caused by the undesirable colonization of microbes on membrane surfaces. The economic penalties associated with this menace are enormous. The traditional preventive measures are dominated by biocides, toxic chemicals, cleaners and antifouling surfaces, which are costly and often cause secondary pollution. Recent focus is thus being directed to promote inputs from nanotechnology to control and mitigate this major threat. Different anti-microbial nanomaterials can be effectively used to prevent the adhesion of microbes onto the membrane surfaces and eliminate microbial biofilms, to provide an economical and eco-friendly solution to biofouling. This review addresses the formation of microbial biofilms and biofouling in membrane operations. The potential of nanocomposite membranes in alleviating this problem and the challenges in commercialization are discussed. The antifouling mechanisms are also highlighted, which are not widely elucidated.

Economic load dispatch solution of large-scale power systems using an enhanced beluga whale optimizer

The aim of the optimization economic load dispatch (ELD) problem is to assign the optimal generated power of the thermal units for cost reduction with satisfying the loading of the operational constraints. The ELD is a high-dimensional and non-convex problem that became a more complex problem in the case of optimizing the output generated power of large-scale systems. In this regard, an enhanced version of the Beluga whale optimization (EBWO) is proposed to deal with the ELD of the large-scale systems. Beluga whale optimization (BWO) is an efficient new optimization technique that mimics the behavior of the Beluga whales (BWs) in preying, swimming, and whale fall. However, the BWO may suffer from stagnation in local optima and scarcity of population diversity like other metaheuristics. The proposed EBWO algorithm is presented to render the standard BWO more robust and powerful search by using two strategies including the cyclone foraging motion for boosting the exploitation phase of the optimization algorithm and the quasi-oppositional based learning (QOBL) for improving population diversity. Firstly, Simulations are carried out on seven benchmark functions to prove the validation of the proposed EBWO algorihm compared with five recent algorithms. Then, The performance of the EBWO is checked on 11-units, 40-units, and also 110-unit test systems, and the obtained results of EBWO are compared with other well-known techniques such as the classical BWO, FOX Optimization Algorithm (FOX), Skill Optimization Algorithm (SOA), and Sand Cat swarm optimization (SCSO) as well as the with existing algorithms from the literature including DE, TLBO, MPSO, NGWO, IGA, NPSO, CJAYA, SMA, PSO, PPSO, SSA, MPA, MGMPA, and HSSA. The Numerical results show that the proposed algorithm is very competitive compared with the other reported optimization algorithms in obtaining low fuel costs.

Modulation of gut microbiota and intestinal immune response in gilthead seabream (Sparus aurata) by dietary bile salt supplementation.

Given their role in lipid digestion, feed supplementation with bile salts could be an economic and sustainable solution to alterations in adiposity and intestinal inflammation generated by some strategies currently used in aquaculture. An important part of the metabolism of bile salts takes place in the intestine, where the microbiota transforms them into more toxic forms. Consequently, we aimed to evaluate the gut immune response and microbial populations in gilthead seabream (Sparus aurata) fed a diet supplemented with a blend of bile salts with proven background as a regulator of lipid metabolism and fat content. After the 90-day feeding trial, a differential modulation of the microbiota between the anterior and posterior intestine was observed. While in the anterior intestine the relative abundance of Desulfobacterota doubled, in the posterior intestine, the levels of Firmicutes increased and Proteobacteria, Actinobacteriota, and Campylobacterota were reduced when supplementing the diet with bile salts. Even so, only in the anterior intestine, there was a decrease in estimated richness (Chao1 and ACE indices) in presence of dietary bile salts. No significant differences were displayed in alpha (Shannon and Simpson indices) nor beta-diversity, showing that bile sales did not have a great impact on the intestinal microbiota. Regarding the gene expression profile in 2 h postprandial-fish, several changes were observed in the analyzed biomarkers of epithelial integrity, nutrient transport, mucus production, interleukins, cell markers, immunoglobulin production and pathogen recognition receptors. These results may indicate the development of an intestinal immune-protective status to tackle future threats. This work also suggests that this immune response is not only regulated by the presence of the dietary bile salts in the intestine, but also by the microbial populations that are in turn modulated by bile salts. After a fasting period of 2 days, the overall gene expression profile was stabilized with respect to fish fed the unsupplemented diet, indicating that the effect of bile salts was transient after short periods of fasting. On the balance, bile salts can be used as a dietary supplement to enhance S. aurata farming and production without compromising their intestinal health.

Camera-Based Smart Parking System Using Perspective Transformation

The concept of the “smart city” has emerged with the advancement of technology, but some facilities are not sufficiently intelligent, such as parking lots. Hence, this paper proposes an inexpensive and plug-to-play camera-based smart parking system for airports. The system utilizes inverse perspective mapping (IPM) to provide an aerial view image of the parking lot, which is then processed to extract parking space information. The system also includes a guidance system to assist drivers in finding available parking spaces. The system is simulated on a 3D scene based on the parking lot of Macao International Airport. In the experiment, our system achieved an accuracy rate of 97.03% and a mean distance error of 8.59 pixels. This research study shows the potential of enhancing parking lots using only cameras as data collectors, and the results show that the system is capable of providing accurate and useful information. It performs well in parking lots with open space, in particular. Moreover, it is an economical solution for implementing a smart parking lot.

Advanced Exergoeconomic Assessment of CO2 Emissions, Geo-Fluid and Electricity in Dual Loop Geothermal Power Plant

Binary geothermal power plants (GPPs) are mostly encountered in geothermal fields with medium and low temperatures. The design and operation of dual binary GPPs can be difficult due to the geothermal fluid properties. This affects their performance and feasibility. Thermoeconomics are essential elements for the design and operation of the GPPs. In this study, advanced exergoeconomic analysis is applied to a true dual binary GPP (as a case study) to further evaluate it from performance and economic perspectives. In analysis, the specific exergy cost (SPECO) method is used. Then, some specific indicators are presented to evaluate the performance and economics of the GPP. Thus, technical and economic solutions have been developed in the design and operation stages through the analysis. The results of the study indicated that the total operating cost of 1218 USD/h could be reduced to 186 USD/h by improving the operating conditions. This corresponds to an 85% decrease. The cost per electricity generated, cost per geothermal energy input, and cost per CO2 emission of the GPP are determined as 0.049 USD/kWh, 5.3 USD/GJ, and 0.13 USD/kg, respectively. As a result, while the savings potential of the GPP is 15%, it can result in a 15% reduction in CO2 emission cost.

Quality of Machinery and Equipment Provides a Strategy for the Breakthrough in Mechanical Engineering

The possibilities of solving the problems formed in modern engineering in Russia, associated with the low competitiveness of domestic technology, are investigated. Organizational, technological and economic solutions have been proposed that will accelerate the improvement of product quality and the expansion of production volumes in accordance with the requirements of technological modernization of the country's economy. At the core of these decisions there is the organization of large machine-building companies and complexes capable of raising the quality of mechanical engineering products to the level of the world's best analogues at all stages of the machines’ life cycle, as well as the reasonable choice of the areas of diversification and technological modernization of production, the organization of branded engineering and technical support for manufactured machines and equipment.

Constructing the adaptation economy: Climate resilient development and the economization of vulnerability

Climate resilient development is emerging as a global policy strategy that integrates climate adaptation and mitigation into sustainable development decisions. For the Caribbean small island developing state (SIDS) of Antigua and Barbuda, the national government is pursuing climate resilient development through multilateral climate funds to protect economic growth from climate and weather-related disasters. Critical adaptation literature argues that interpreting climate vulnerability through an economic growth lens prioritizes economic solutions over other development concerns, which can further the uneven distribution of climate vulnerability and risk. Despite revealing the consequences of market-based climate actions, research has yet to fully understand the economization of vulnerability, which describes the political techniques that render and reconfigure vulnerability in calculated ways. By tracing the discursive interactions between multilateral climate financial institutions and the Antigua and Barbuda national government, this paper empirically examines how vulnerability is economized through climate resilient development. Findings identify the construction of ‘adaptation economies’ in watershed areas, which are economies that can capitalize upon climate challenges within areas of highest vulnerability through fee-for-climate services. The results illustrate that economic growth rationalities characterize climate vulnerability problematizations, which incentivize solutions that enforce the economic development of areas with the highest disaster impacts. Based on these findings, this study emphasizes a need to critically evaluate national actor efforts to re-organize development under climate financing rationales, and its vulnerability-inducing effects.

Advances in Halloysite Nanotubes (HNTs)‐Based Mixed‐Matrix Membranes for CO2 Capture

AbstractMembrane technology promises a highly economical and efficient solution for CO2 separation. Many polymeric membranes have been reported in the past for the separation of gases specially to remove CO2 from natural gas and low‐pressure flue‐gas streams. The performance of membranes can be tailored by dispersing nanofillers in a polymeric matrix to produce mixed‐matrix membranes (MMMs). This not only adds mechanical strength to membranes but also reduces compaction of the polymeric layer at high pressure and maintains high performance. Halloysite nanotubes (HNTs) gained attention in gas separation technology and due to their tubular structure have been used in a variety of applications in biomedical, coating, composite, and electronic industries. However, very little but conclusive literature and reviews are available to indicate that functionalized and non‐functionalized HNTs can improve the performance of MMMs for efficient CO2 capture. The current status and gaps for potential applications of HNTs‐based membranes for gas separation are identified and reviewed.

Suspended solid removal efficiency of plate settlers and tube settlers analysed by CFD modelling.

Removal of suspended solids from raw water is an essential process in water treatment plants. Conventional sedimentation tanks in water treatment plants occupy a large area and become expensive in urban areas. The use of plate settlers or tube settlers in sedimentation tanks to increase the efficiency and hence reduce the footprint of sedimentation tanks is an economical solution in water treatment. This study investigated the effectiveness of plate and tube settlers compared to conventional settlers in a water treatment plant. A three-dimensional Computational Fluid Dynamics (CFD) model was set up using ANSYS-CFX 17.2. Seven cases (a conventional settler, three plate settlers and three tube settlers) were analysed to compare the settler performances. The maximum removal efficiencies of all solid classes were approximately equal in plate and tube settlers with the same plate spacing and tube depth: around 100%, 67%, 28% and 9% for the solid classes with particle diameters of 41, 17, 9.5 and 5.0 µm, respectively. The settling efficiency remained unchanged with the increase of the plate settling area beyond 60% of the conventional settler area under the given tank and flow conditions. The tube cross-section shape does not affect the particle removal efficiency of a tube settler.

Scalable, economical, and stable sequestration of agricultural fixed carbon.

We describe a scalable, economical solution to the carbon dioxide problem. CO2 is captured from the atmosphere by plants, and the harvested vegetation is then buried in an engineered dry biolandfill. Plant biomass can be preserved for hundreds to thousands of years by burial in a dry environment with sufficiently low thermodynamic "Water Activity," which is the relative humidity in equilibrium with the biomass. Maintaining a dry environment within the engineered dry biolandfill is assisted by salt that preserves biomass, which has been known since Biblical times. A "Water Activity" <60%, assisted by salt, will not support life, suppressing anaerobic organisms, thus preserving the biomass for thousands of years. Current agricultural costs, and biolandfill costs, indicate US$60/tonne of sequestered CO2 which corresponds to ~US$0.53 per gallon of gasoline. The technology is scalable owing to the large area of land available for nonfood biomass sources. If biomass production is scaled to the level of a major crop, existing CO2 can be extracted from the atmosphere, and will simultaneously sequester a significant fraction of world CO2 emissions.

Research on Smart Power Sales Strategy Considering Load Forecasting and Optimal Allocation of Energy Storage System in China

With the deepening reform of the power system, power sales companies need to adopt new power sales strategies to provide customers with better economic marketing solutions. Customer-side configuration of an energy storage system (ESS) can participate in power-related policies to reduce the comprehensive cost of electricity for commercial and industrial customers and improve customer revenue. For power sales companies, this can also attract new customers, expand sales and quickly capture the market. However, most of the ESS evaluation models studied so far are based on historical data configuration of typical daily storage capacity and charging and discharging scheduling instructions. In addition, most models do not adequately consider the performance characteristics of the ESS and cannot accurately assess the economics of the energy storage model. This study proposes an intelligent power sales strategy based on load forecasting with the participation of optimal allocation of ESS. Based on long short-term memory (LSTM) artificial neural network for predictive analysis of customer load, we evaluate the economics of adding energy storage to customers. Based on the premise of the two-part tariff, the ESS evaluation model is constructed with the objective of minimizing the annual comprehensive cost to the user by considering the energy tariff and the savings benefits of the basic tariff, assessing the annualized cost of ESS over its entire life cycle, and the impact of battery capacity decay on economics. The particle swarm optimization (PSO) algorithm is introduced to solve the model. By simulating the arithmetic example for real customers, their integrated electricity costs are significantly reduced. Moreover, this smart power sales strategy can provide different sales strategies according to the expected payback period of customers. This smart sales strategy can output more accurate declared maximum demand values than other traditional sales strategies, providing a more economical solution for customers.

Utilization of Waste Plastic in the Way of Synthetic Bricks

Nowadays plastic waste is a hazardous problem for mortality. Plastic waste is non-biodegradable waste that cannot decompose and creates environmental pollution. There is a big question about circular economy and recycling after the usage of plastic and their sustainable management. Most of the research presented that plastic waste is double every decade. Usually, bricks are made of clay, and due to excessive use of the clay, it shows results in resource depletion and environmental degradation. The present study explores a critical review of valuable and eco-friendly ways to minimize the environmental impact of waste plastic. Therefore, plastic wastes are used to prepare the bricks. It is the most economical solution in the construction industry. For this work, masonry brick blocks with different batching proportion of traditional raw materials with plastic were casted. Sample A was prepared with different ratio of sand and plastic pulp while sample B was organized with different ratio of powdered sample A1) and cement. Then they were allowed to dehydrating to confirm free from moisture. This research was compared density, water absorption, compressive strength and flexural strength of the sample A, sample B, and locally available conventional brick. According to the analysis the sample A1 was exhibited the peak value of compressive strength and flexural strength of 280 kg-cm-2and 70 kg-cm-2 respectively which is three times higher than the commercially available product in Sri Lanka. In addition to this, water absorption was revealed 1.23% which is six times lower than the sample brick and it was displayed an acceptable value of density (1872.45 kg-3). So, sample A1 (1:1, plastic: sand) is highly recommended for construction purposes.