Correction: Recent trends in carbon nanotube (CNT)-based biosensors for the fast and sensitive detection of human viruses: a critical review.

[This corrects the article DOI: 10.1039/D2NA00236A.].

Influence of high porous sponges for improving the interfacial evaporation from hemispherical solar distillers.

The present study aims to improve the palatable water production from the hemispherical cover solar distiller (HSD). To augment the palatable water produced from the hemispherical cover, a black sponge was utilized as a porous medium using different thicknesses, which augments the interfacial evaporation through the capillary effect of the water through the sponge. The rate of condensation of the hemispherical cover depends on the higher interaction of air from the ambient through wind velocity as the exposure area of the hemispherical cover is relatively higher as compared to the other traditional distillers. The rate of evaporation from the distillers depends on the interfacial materials used in the distillation unit, and this is achieved by using a highly porous black sponge to attain a higher evaporation rate. The thickness of the black porous sponge was optimized (1 to 4 cm), which was the operating parameter for better interfacial evaporation through the sponge, and the same has been compared to the conventional HSD without a porous sponge medium. Results showed a significant improvement in the evaporation rate using a porous medium as the palatable water produced from the HSD was improved by 72.29% using 3 cm as sponge thickness inside compared to the conventional HSD without the porous medium. The cumulative palatable water produced from the HSD using 3 cm as sponge thickness was found as 7150 mL/m2, whereas the conventional HSD without sponge, it was found as 4150 mL/m2. Moreover, using a porous sponge layer as an interfacial evaporation medium, the exergy and energy efficiencies were improved by about 512.87 and 70.53%, respectively. Similarly, with the influence of a porous sponge as an interfacial evaporation medium, the distilled water cost decreased by 41.67% more than the conventional HSD.

Experimental Investigation of a Plate-Frame Water Gap Membrane Distillation System for Seawater Desalination.

This study presented a detailed investigation into the performance of a plate-frame water gap membrane distillation (WGMD) system for the desalination of untreated real seawater. One approach to improving the performance of WGMD is through the proper selection of cooling plate material, which plays a vital role in enhancing the gap vapor condensation process. Hence, the influence of different cooling plate materials was examined and discussed. Furthermore, two different hydrophobic micro-porous polymeric membranes of similar mean pore sizes were utilized in the study. The influence of key operating parameters, including the feed water temperature and flow rate, was examined against the system vapor flux and gained output ratio (GOR). In addition, the used membranes were characterized by means of different techniques in terms of surface morphology, liquid entry pressure, water contact angle, pore size distribution, and porosity. Findings revealed that, at all conditions, the PTFE membrane exhibits superior vapor flux and energy efficiency (GOR), with 9.36% to 14.36% higher flux at a 0.6 to 1.2 L/min feed flow rate when compared to the PVDF membrane. The copper plate, which has the highest thermal conductivity, attained the highest vapor flux, while the acrylic plate, which has an extra-low thermal conductivity, recorded the lowest vapor flux. The increasing order of GOR values for different cooling plates is acrylic < HDPE < copper < aluminum < brass < stainless steel. Results also indicated that increasing the feed temperature increases the vapor flux almost exponentially to a maximum flux value of 30.36 kg/m2hr. The system GOR also improves in a decreasing pattern to a maximum value of 0.4049. Moreover, a long-term test showed that the PTFE membrane, which exhibits superior hydrophobicity, registered better salt rejection stability. The use of copper as a cooling plate material for better system performance is recommended, while cooling plate materials with very low thermal conductivities, such as a low thermally conducting polymer, are discouraged.

Characteristics estimation of natural fibre reinforced plastic composites using deep multi-layer perceptron (MLP) technique.

Polymer Matrix Composite (PMC/Plastic Composite) often referred to as Plastic Composite with Natural fibre reinforcement has a huge interest in industries to manufacture components for various applications including medical, transportation, sports equipment etc. In the universe, different types of natural fibres are available which can be used for the reinforcement in PMC/Plastic Composite. So, the selection of appropriate fibre for the PMC/Plastic Composite/Plastic composite is a challenging task, but it can be done using an effective metaheuristic or optimization techniques. But in this type of optimal reinforcement fibre or matrix material selection, the optimization is formulated based on any one of the parameters of the composition. Hence to analyse the various parameter of any PMC/Plastic Composite/Plastic Composite without real manufacturing, a machine learning technique is recommended. The conventional simple or single-layer machine learning techniques were not sufficient to emulate the exact real-time performance of the PMC/Plastic Composite. Thus, a deep multi-layer perceptron (Deep MLP) algorithm is proposed to analyse the various parameter of PMC/Plastic Composite with natural fibre reinforcement. In the proposed technique the MLP is modified by including around 50 hidden layers to enhance its performance. In every hidden layer, the basis function is evaluated and subsequently, the sigmodal function-based activation is calculated. The proposed Deep MLP is utilized to evaluate the various parameters of PMC/Plastic Composite Tensile Strength, Tensile Modulus, Flexural Yield Strength, Flexural Yield Modulus, Young's Modulus, Elastic Modulus and Density. Then the obtained parameter is compared with the actual value and the performance of the proposed Deep MLP is evaluated based on the accuracy, precision, and recall. The proposed Deep MLP attained 87.2%, 87.18%, and 87.22% of accuracy, precision, and recall. Ultimately the proposed system proves that the proposed Deep MLP can perform better for the prediction of various parameters of PMC/Plastic Composite with natural fibre reinforcement.

Sustainable wastewater treatment by RO and hybrid organic polyamide membrane nanofiltration system for clean environment.

One of the environmental pollution is happened by the discharge of industrial wastewater that needs to be adequately filtered. Given that the effluent from the leather industry contains high levels of chromium, heavy metals, lipids, and Sulphur, it is one of the wastewater disposals that are most damaging. This experimental study focuses on reverse osmosis and hybrid organic polyimide membrane for nanofiltration for sustainable wastewater treatment. In the RO and organic polyamide Nano-porous membranes, a thin film of polyamide membrane was used for efficient filtration. Taguchi analysis optimized process parameters such as pressure, temperature, pH, and volume reduction factor. The outcome shows an 89% reduction in total wastewater hardness, an 88% reduction in sulfate, and an 89% efficiency reduction in COD. As a result, the proposed technology significantly increased filtration efficiency.

The clean energy aspect of plastic waste - hydrogen gas production, CO2 reforming, and plastic waste management coincide with catalytic pyrolysis - an extensive review.

Clean hydrogen has future fuel capable of receiving an abundance of carbon-neutral energy from hydrogen. In the recent world, new hydrogen affirmation projects have been launched for a green environment. On another side, plastic waste and CO2 threaten the green environment. Vacuum in plastic waste management, plastic waste leads to exhibiting harmful chemicals to the environment. The growth rate of the CO2 concentration in air is 2.45 ppm per year, steadily increasing in 2022. It is realized that uneven climate change, temperature raising the global level, ocean mean level raising, and frequent acidification are dangerous to living and ecosystems. This review discussed tackling multiple harmful environmental fatly by pyrolysis techniques; catalytic pyrolysis is almost reaching the commercialization stage. Recent pyrolysis upgradation methods with hydrogen gas production and the continuous development and execution of sustainable solutions for plastic waste management and CO2 reforming are discussed. Production of carbon nanotubes by plastic waste, the importance of catalyst modification, and the effect of catalyst deactivation are discussed. From this study, integrating the different applications with catalytic modification creates room for multipurpose pyrolysis, CO2 reforming, and hydrogen gas production by pyrolysis techniques capable of giving a sustainable solution for climate change issues and a clean environment. Additionally, carbon utilization by way of carbon nanotube production is also done. Overall, the review supports achieving clean energy from plastic waste.

Performance evaluation of external compound parabolic concentrator integrated with thermal storage tank for domestic solar refrigeration system.

The aim of this research was to develop a model for a solar refrigeration system (SRS) that utilizes an External Compound Parabolic Collector and a thermal energy storage system (TESS) for solar water heating in Chennai, India. The system parameters were optimized using TRNSYS software by varying factors such as collector area, mass flow rate of heat transfer fluid, and storage system volume and height. The resulting optimized system was found to meet 80% of hot water requirements for the application on an annual basis, with an annual collector energy efficiency of 58% and an annual TESS exergy efficiency of 64% for a discharge period of 6 h per day. In addition, the thermal performance of 3.5 kW SRS was studied by connecting it to an optimized solar water heating system (SWHS). The system was found to generate an average cooling energy of 12.26 MJ/h annually, with a coefficient of performance of 0.59. By demonstrating the ability to efficiently generate both hot water and cooling energy, the results of this study indicate the potential for utilizing a SWHS in combination with STST and SRS. The optimization of system parameters and the use of exergy analysis provide valuable insights into the thermal behavior and performance of the system, which can inform future designs and improve the overall efficiency of similar systems.

A Review on CNTs-Based Electrochemical Sensors and Biosensors: Unique Properties and Potential Applications.

Carbon nanotubes (CNTs), are safe, biocompatible, bioactive, and biodegradable materials, and have sparked a lot of attention due to their unique characteristics in a variety of applications, including medical and dye industries, paper manufacturing and water purification. CNTs also have a strong film-forming potential, permitting them to be widely employed in constructing sensors and biosensors. This review concentrates on the application of CNT-based nanocomposites in the production of electrochemical sensors and biosensors. It emphasizes the synthesis and optimization of CNT-based sensors for a range of applications and outlines the benefits of using CNTs for biomolecule immobilization. In addition, the use of molecularly imprinted polymer (MIP)-CNTs in the production of electrochemical sensors is also discussed. The challenges faced by the current CNTs-based sensors, along with some the future perspectives and their future opportunities, are also briefly explained in this paper.

RESEARCH HIGHLIGHTSReview article on advanced Carbon-Nanotube (CNT)-based sensors and biosensors.The advantages of using CNTs for biomolecule immobilization and in electrochemical sensors and biosensors are discussed.The use of molecularly imprinted polymer-CNT nanocomposites in the production of electrochemical sensors is also discussed.Several characteristics, including sensor manufacturing, linear ranges, detection limits, and repeatability, are described in depth.Challenges and prospects using CNTs modified sensors have been proposed.

Recent trends in carbon nanotube (CNT)-based biosensors for the fast and sensitive detection of human viruses: a critical review.

The current COVID-19 pandemic, with its numerous variants including Omicron which is 50-70% more transmissible than the previously dominant Delta variant, demands a fast, robust, cheap, and easily deployed identification strategy to reduce the chain of transmission, for which biosensors have been shown as a feasible solution at the laboratory scale. The use of nanomaterials has significantly enhanced the performance of biosensors, and the addition of CNTs has increased detection capabilities to an unrivaled level. Among the various CNT-based detection systems, CNT-based field-effect transistors possess ultra-sensitivity and low-noise detection capacity, allowing for immediate analyte determination even in the presence of limited analyte concentrations, which would be typical of early infection stages. Recently, CNT field-effect transistor-type biosensors have been successfully used in the fast diagnosis of COVID-19, which has increased research and commercial interest in exploiting current developments of CNT field-effect transistors. Recent progress in the design and deployment of CNT-based biosensors for viral monitoring are covered in this paper, as are the remaining obstacles and prospects. This work also highlights the enormous potential for synergistic effects of CNTs used in combination with other nanomaterials for viral detection.

Computational fluid dynamics-based parametric study on the performance of solar air heater channel.

Computational fluid dynamics (CFD) plays a prominent role in the design and development of solar air heaters. The previous investigations have lagged in using a radiation model for the solar heat input; instead, most of the researchers simulated a constant heat flux model. Moreover, an extensive study on the geometrical and boundary conditions like confinement and transition length, suction, and blowing effects has not been studied. The present investigation deals with the aforementioned effects on the flow and heat transfer characteristics of the SAH channel, which is designed for residential space heating. The finite volume-based solver Ansys Fluent is used for finding the field variables. The confinement height is varied from 25 to 150 mm, and the transition length is varied from 250 to 1000 mm. The suction and blowing effect is investigated by changing the flow direction across the channel. Even though the temperature rise is less significant with respect to confinement height and transition length, the effective efficiency increases with decreasing channel height and increasing transition length. In general, blowing of air across the channel gives better performance than suction. When comparing them, the influence is less in temperature rise and more in pressure drop for the channel height of 25 mm, whereas the channel height of 150 mm has better influence in temperature rise and less influence in pressure drop.

Concentrator-assisted solar still for improving freshwater yield: an experimental approach.

The present experimental study aims to make advancements in the daily production of freshwater by a single solar still, with the ultimate goal of increasing its efficiency. The experiment was carried out in the solar still with and without integration at four different water masses within the basin, and metrics such as water, glass, basin temperature, and drinkable water generated were measured. The results showed that the daily distillate collected from the integrated system using 2.5 kg/h of mass flow in the parabolic concentrator produced 2.99 kg at the minimum water mass of 20 kg placed in the basin. When the flow velocity of water in the parabolic concentrator is raised from 2.5 to 5 kg/h, the amount of freshwater generated decreases from 2.99 to 2.66 kg. Compared to traditional single slope solar still, the potable water generated increases by roughly 18.24, 18.29, and 18.33% for water mass of 30, 40, and 50 kg, respectively, with the mass flow rate of water in the serpentine tubes as 2.5 kg/h. The results also reveals that, in addition to the PTC collector, the mass flowrate of fluid in the serpentine tube arrangement submerged in the basin affects daily solar efficiency. There is a significant reduction of about 1-2.3% in the daily efficiency of the system with increased mass flow rate of fluid in the serpentine tube arrangement. Similarly, the daily efficiency in all the cases reduces with increased water depth.

Hemispherical Solar Distiller Performance Utilizing Hybrid Storage Media, Paraffin Wax with Nanoparticles: An Experimental Study.

The traditional method of obtaining fresh water for drinking is by burning fossil fuels, emitting greenhouse gases into the atmosphere. However, renewable energy is gaining more traction since it is available free of cost for producing fresh water. In this study, Al2O3 nanoparticles were distributed in a phase change material (paraffin wax) that had been fixed at a hemispherical distiller water basin. Three scenarios with three hemispherical distillers were examined. A conventional hemispherical distiller (CHD), a conventional hemispherical distiller with paraffin wax as a phase change material (CHD-PCM), and a conventional hemispherical distiller with PCM partially filled with Al2O3 nanoparticles (CHD-N-PCM) were tested under the same climatic conditions. The experimental results showed that CHD gave a daily yield of 4.85 L/m2/day, while CHD-PCM increased the yield to up to 6.2 L/m2/day with a 27.84% daily yield enhancement. The addition of Al2O3 nanoparticles to paraffin wax CHD-N-PCM improved hemispherical distillate yield up to 8.3 L/m2/day with a 71.13% increase over CHD yield.

A review about COVID-19 in the MENA region: environmental concerns and machine learning applications.

Coronavirus disease 2019 (COVID-19) has delayed global economic growth, which has affected the economic life globally. On the one hand, numerous elements in the environment impact the transmission of this new coronavirus. Every country in the Middle East and North Africa (MENA) area has a different population density, air quality and contaminants, and water- and land-related conditions, all of which influence coronavirus transmission. The World Health Organization (WHO) has advocated fast evaluations to guide policymakers with timely evidence to respond to the situation. This review makes four unique contributions. One, many data about the transmission of the new coronavirus in various sorts of settings to provide clear answers to the current dispute over the virus's transmission were reviewed. Two, highlight the most significant application of machine learning to forecast and diagnose severe acute respiratory syndrome coronavirus (SARS-CoV-2). Three, our insights provide timely and accurate information along with compelling suggestions and methodical directions for investigators. Four, the present study provides decision-makers and community leaders with information on the effectiveness of environmental controls for COVID-19 dissemination.

Use of waste fish oil biodiesel blended with aluminium oxide nanoparticle in IC engines: an experimental on performance, combustion and emission study.

Alternate fuels are in great need as the world's natural resources are depleting with continuous consumption. Furthermore, with a continuous increase in the use of conventional fuel which emits a large number of harmful pollutants to the environment and thus increasing global warming, the need for alternative fuel is in great need. This investigation thus focused on the impact identification on the use of biodiesel from fish waste-based biodiesel [BDWFO (Bio-Diesel of Waste Fish Oil)] with Nanoparticles in single cylinder water cooled IC engine. The fish wastes in fish processing industries/fish markets are used to produce oil and its biodiesel is produced by the transesterification method. The individual BDWFO, Diesel, and blends of 20% of BDWFO were tested with the engine. Then another two combinations of fuel created 200 ppm of 40 nm Aluminium Oxide nanoparticles (AN) mixed with BDWFO, blends of 20% of BDWFO. These five fuels were considered to study the engine performance, combustion, and emissions from the exhaust. The experimental results confirmed the presence of aluminium oxide nanoparticles in BDWFO provides improved engine performance and reduced emissions from exhaust gas except for CO2.

An experimental approach on the utilization of palm oil biodiesel with higher concentration of Al2O3 nanoadditive for performance enhancement and emission reduction.

Demand for energy is one of the crises that the whole world is now facing as a direct result of the rapid depletion of fossil resources. Because of the many positive effects that biodiesel may have on both the economy and the environment, a significant amount of study has been conducted on the topic in recent years. In order to improve the physiochemical qualities, a number of researchers have been conducting studies to determine whether or not biodiesel can be used effectively as a renewable fuel in diesel engines. This research report presents the findings of an experimental investigation into the use of aluminium oxide nanoparticles as an additive in alternative fuel made from palm oil biodiesel. The investigation was carried out in the context of a nanoparticle mix. The method of transesterification is used in the manufacturing of biodiesel. The properties of the tested using American Society of Testing Methods (ASTM). The results showed that there is a significant increase in the brake thermal efficiency and a reduction of the brake-specific fuel consumption from the engine using biodiesel blends. When compared to the diesel fuel in the engine, the brake thermal efficiency of the engine fuelled using POBD20 with 50 ppm Al2O3 nanoadditive and POBD20 is found to be 11.78 and 4.76% respectively, while the engine is operated at peak load. However, the BTE is improved by about 14.16, 15.69, 20.55 and 18.39% using POBD20 and POBD20 with 25, 50 and 75 ppm Al2O3 nanoadditive respectively compared to neat palm oil biodiesel. The improvement in the BTE of the engine would be completely due to the existence of higher thermal conductivity nanoparticle which enhanced the surface to volume ratio with in the fuel. This acts as a chemical catalyst during the combustion and thereby increases the burning rate of fuel inside the combustion chamber. Furthermore, the analysis revealed that the NOx formation increased with other emissions such as carbon monoxide (CO) and unburnt hydrocarbons (UBHC) which are reduced.

Analysis of a solar still with photovoltaic modules and electrical heater - Energy and exergy approach.

The availability of drinkable water, along with food and air, is a fundamental human necessity. Because of the presence of higher amounts of salt and pollution, direct use of water from sources such as lakes, sea, rivers, and subsurface water reservoirs is not normally suggested. Solar is still a basic technology that can use solar energy to transform accessible waste or brackish water into drinkable water. Exergy analysis is a strong inferential technique for evaluating the performance of thermal systems. Exergy is becoming more popular as a predictive tool for analysis, and there is a rising interest in using it. In this paper, performance analysis on the aspect of energy and exergy from the proposed solar still (PSS) (conventional solar still with the photovoltaic modules-AC heater) was analyzed on three different water depths (Wd) conditions (1, 2, and 3 cm). Using a solar still with an electric heater, the daily potable water production was found as 8.54, 6.37, and 4.43 kg, for the variations in water depth (Wd) of 1, 2, and 3 cm respectively. The energy and exergy efficiency of the PSS at the Wd of 1, 2, and 3 cm were 75.67, 51.45, and 37.21% and 5.08, 2.29, and 1.03%, respectively. At 1 cm Wd, PSS produced the maximum freshwater yield as compared to the other two water depths. When the Wd is increased from 1 to 2 cm and from 1 to 3 cm, the yield is decreased up to 27.3 and 52.7%, respectively. Similarly, the energy and exergy efficiency is decreased up to 36.8 and 53.2% and 50.4 and 80.6%, respectively. The water cost of the modified solar still is calculated as 0.028 $/kg for the least water thickness.

Comparative studies on performance of solar towers with variable scale ratios.

Improvements in the geometry of solar towers are explained in this study. Both computational and experimental studies are carried out. Three different solar towers of 1:60, 1:70, and 1:122 scale ratios are taken for the study. All the studies are carried out in an open atmosphere, where a hot wire anemometer is used to measure the peak velocity at the collector-tower junction. The collector geometry is kept flat, inclined, and semi-divergent. The tower geometry is modified from the straight tower into semi-divergent and fully divergent towers. The fully divergent tower with a semi-convergent collector achieves the highest power output among the other two models. The area convergence is the prime factor for an increase in peak velocity. The divergent tower with a semi-convergent collector achieves 54% more power output than a cylindrical tower with a flat collector.

Solar distillation meets the real world: a review of solar stills purifying real wastewater and seawater.

Solar energy-driven evaporation-based freshwater production is one of the sustainable ways to purify contaminated/salty water. Recent advances in solar absorbers' assemblies, design modifications, and integrations with heating sources improved the rate of freshwater productivity. However, the type of feed water affects the evaporation rate in a solar desalination system (SDS). Many studies used tap water with added contaminants to test the performance of a SDS and studied the water quality improvement. As a typical result, pH, total dissolved solids (TDS), and electrical conductivity (µS/cm) are reduced after solar evaporation. The performance of SDSs for real wastewaters are also important to understand, e.g., the reduction of high organic pollutants after solar evaporation. In this aspect, the main objective of the present work is to review solar distillation of real wastewaters and seawater by using SDSs. Further, the mechanism of a solar distiller with heat transfer principles, parameters affecting evaporation process, real wastewaters and seawaters purified in a solar distillation system, improvement of various parameters before and after solar evaporation, pathways of handling wastewaters, challenges, and future perspectives are discussed. Conclusively, SDSs are found to remove pollutants effectively after solar evaporation. The evaporation rate is relatively slower due to high concentration of pollutants that reduce vapor pressure. The COD removal of various real wastewaters, including sludge, kitchen, textile, palm oil, petroleum, water plant, and municipal wastewaters, was 98.13%, 97.85%, 96.84%, 96.71%, 87.99%, 86.99%, and 85.67%, respectively. The reduction rate of salt concentration in real seawater after evaporation in the solar distiller was 99.99%.

Performance improvements of hemispherical solar still using internal aluminum foil sheet as reflector: energy and exergy analysis.

Various scientists are looking for effective and easy solutions for the augmentation of yield from the hemispherical solar still (HSS). In this study, aluminum foil sheet was used to reflect the intensity, hence augmenting the evaporation rate and daily yield. Experimentations were conducted on two SS: the first SS is HSS; the second SS is HSS with reflective aluminum foil sheet walls (HSS-RAFW). The highest distilled water production from the HSS and HSS-RAFW is 3.36 and 4.1 kg/m2, respectively. Compared to the HSS, the yield of distilled water was augmented by 22.21% when using the HSS-RAFW. The daily energy and exergy efficiencies (EnE and ExE) of the HSS are 26.27 and 1.04%, respectively, and the daily EnE and ExE of the HSS-RAFW are 32.75 and 1.71%, respectively.

Improving the potable water generation through tubular solar still using eggshell powder (bio-based energy source) as a natural energy storage material - an experimental approach.

The demand for fresh water is rapidly growing as a consequence of the increasing population and urbanization. Tubular solar still offers larger evaporative and condensing surface area as compared to single slope solar still. The aim of this study is to improve the performance of tubular solar still by employing eggshell powder (collected from Babcobb Broilers chicken) as the sensible energy storage material in form of bed, placed inside the basin of still to improve the water production. Results showed that the influence of eggshell powder as energy storage material in the basin improved the average water temperature by 3%, 6.2%, and 3.2% for the water thickness of 10, 15, and 20 mm, respectively. The usage of eggshells as a sensible energy storage in the basin augmented the peak hourly water yield by 67.64% with minimum water thickness. The total observed distillate output from the solar still is 1.45 kg without eggshell powder and 2.67 kg for with eggshell powder in the absorber at the lowest water thickness of 10 mm. TSS with eggshell powder as energy storage has a daily energy efficiency of 48.17%, 42.38%, and 36.38%, respectively, for water thicknesses of 10, 15, and 20 mm in the basin. Water thickness of 10, 15, and 20 mm has performance improvement ratios of 1.83, 1.81, and 1.78, respectively. Using cost analysis, it was found that the cost of drinkable water generated using eggshell as an energy storage material is 0.011$/kg, but the cost of water by traditional still without any storage material was 0.021$/kg.