Environmental Control Applications Research Articles

Bio-potentials for smart control applications

This study demonstrates the capabilities of bio-potentials especially Electrooculography (EOG) for smart environmental control applications. Furthermore, In this study, we have proposed a novel, user-friendly, low cost, and wearable Man Machine Interface (MMI) for practical use out of a controlled laboratory environment. EOG based MMI framework is designed by using consumer-grade single channel Brain-Computer Interface (BCI) device. Acquired signals are filtered and processed for feature extraction. Eye blink signals are detected and decoded using Application Program Interface (API) developed in MATLAB. Four setups for real-time control experiments spanning over 300 trials are conducted to test the efficiency of EOG signals for smart environmental control applications. Additionally, real-time wheelchair control experiments are performed by five volunteers for testing and cross-validating the quantitative and qualitative factors of designing MMI. Finally, results of wheelchair control experiments are compared and contrasted with similar established MMI frameworks. Overall, Four setups of smart control experiments conveyed an average precision of 96.44%, 99.30%, 97.11%, and 95.78%, respectively, with a good response time ranging between 1.65 s to 2.23 s for two participants with 300 trials. Whereas for wheelchair control experiment, wherein five subjects volunteered, an average accuracy of 93.89% and 62.29 bits/min of Information Transfer Rate (ITR) were obtained with zero collision and zero False Positive Rate (FPR). From the results it can be inferred that, EOG signals can be applied to different smart environment control application with great potential; Proposed single channel EOG based MMI framework can provide a robust, practical, user-friendly yet at the same time precise and responsive interface for control applications at a moderate cost. In this investigation, an effective, low cost, wearable inter has been presented for the variety of users and various applications. When contrasted with the recently established comparative MMIs, the displayed framework gives a novel and proficient interfaces without Graphical User Interface (GUI) with more prominent exactness and better ITR.

Surface cytometer for fluorescent detection and growth monitoring of bacteria over a large field-of-view.

Monitoring the early onset of bacterial film formation is critical in many clinical, environmental, and food quality control applications. We built a small inexpensive optical surface cytometer, in contrast with bulk spectroscopic methods, around a light-emitting diode (LED) and a complementary metal-oxide-semiconductor (CMOS) image sensor. It is designed to offer a large field-of-view of 200 mm2 and a large depth-of-field of 2-3 mm to overcome the limitations of routine methods like spectrophotometry and fluorescence microscopy. It provides a direct measurement without the need for complex image post-processing with a limit-of-detection around 104 cells/mm2, which is competitive with other similar yet more complex devices already available.

Fluorescent sensor for indirect measurement of methyl parathion based on alkaline-induced hydrolysis using N-doped carbon dots

High-performance measurement of methyl parathion (MP) is of great importance in both agricultural and environmental surveillance. Herein, we presented a facile fluorescent biosensor to indirectly measure MP using N-doped carbon dots (N-CDS) based on the inner filter effect (IFE). Methyl parathion was employed as the substrate of alkaline-catalytic hydrolysis, and p-nitrophenol (p-NP) was obtained by rapid the hydrolysis reaction under strong alkaline conditions without enzymes. Interestingly, the absorption band of p-NP appeared at 403 nm, which presented an overlapping spectrum with the excitation of N-CDs (410 nm). Due to its strong molar absorptivity, p-NP played the part of a powerful absorber in IFE to influence the excitation of fluorophore (N-CDs). Through the competitive absorption, the fluorescence intensity of N-CDs decreased extremely. With optimum conditions selected, the fluorescent sensor presented a concentration-dependent fluorescent response (ΔF) to MP ranging from 0.075 to 15 ppm (R2 =0.9956). The limit of detection was calculated to be 1.87 ppb (S/N = 3) with good selectivity. Successful measurement of MP in spiked river water and apple samples demonstrated that as-proposed optical sensor provided an alternative strategy for real applications in environmental and food safety control.

An SNN Ontology Based Environment Monitoring Method for Intelligent Irrigation System

In order to realize high precision of environment parameters detection in irrigation applications, a sensor and sensor network (SSN) ontology based data fusion method is proposed. An SSN sub-ontology for soilstate monitoring is revised, which includes the sensing devices hierarchies and measurement properties selection according to the detection feature interests. As for sensor data processing, a tuning data method by data pool filtering and clustering is adopted, as well as a useful data fusion method for multi-sensor system. The testing results show that both the accuracy and efficiency of the proposed method are higher after related filtering and clustering process, which enables a thorough monitoring for intelligent irrigation systems and can be extended into environment monitoring and control applications.

Magnetic Photocatalyst BiVO₄/Mn-Zn ferrite/Reduced Graphene Oxide: Synthesis Strategy and Its Highly Photocatalytic Activity.

Magnetic photocatalyst BiVO4/Mn-Zn ferrite (Mn1−xZnxFe2O4)/reduced graphene oxide (RGO) was synthesized by a simple calcination and reduction method. The magnetic photocatalyst held high visible light-absorption ability with low band gap energy and wide absorption wavelength range. Electrochemical impedance spectroscopies illustrated good electrical conductivity which indicated low charge-transfer resistance due to incorporation of Mn1−xZnxFe2O4 and RGO. The test of photocatalytic activity showed that the degradation ratio of rhodamine B (RhB) reached 96.0% under visible light irradiation after only 1.5 h reaction. The photocatalytic mechanism for the prepared photocatalyst was explained in detail. Here, the incorporation of RGO enhanced the specific surface area compared with BiVO4/Mn1−xZnxFe2O4.The larger specific surface area provided more active surface sites, more free space to improve the mobility of photo-induced electrons, and further facilitated the effective migration of charge carriers, leading to the remarkable improvement of photocatalytic performance. Meanwhile, RGO was the effective acceptor as well as transporter of photo-generated electron hole pairs. •O2− was the most active species in the photocatalytic reaction. BiVO4/Mn1−xZnxFe2O4/RGO had quite a wide application in organic contaminants removal or environmental pollution control.

The theory of acoustic sensors application in air quality control

Acoustic sensors based on piezoelectric resonators are widely used in the real-time monitoring of mass and in situ analysis of air composition, for example in environmental, health care and air quality control (AQC) applications, both indoor and outdoor. Recent advances in the QCM techniques include the possibility of measuring changes in resonance frequency, ∆f, and the dissipation, ∆D (so-called QCM-D sensors). Another field of application is measurements of different overtones, which can provide additional information about the system. The sensing layers in QCM devices are often polymer- or supported membrane-based, both of which are soft (viscoelastic) materials. Viscoelasticity of adsorbed layers must thus be taken into account for adequate interpretation of QCM data.This publication describes theoretical results, including analytical formulae for the resonance frequency shift and the dissipation of QCM-D, for two viscoelastic layers deposited onto resonator surface, as well as calculations for higher harmonics. In particular, the corrections in ∆f and ∆D due to the softness of the top layer, considered as a bulk, are written explicitly in terms of the layer's material parameters. The results can be useful for quantitative analysis of measured characteristics of QCM in AQC, environmental monitoring and biosensor applications.

Novel Electrically Stimulated Catalytic Converter Prototype for Replacement of Conventional Auto Exhaust Emission Converters

High voltage electrostatics and corona discharge are utilized for various applications in pollution and environmental control. The traditional applications have many flaws due to improper construction of electrode design and assembly that cause system failure, in particular when electrically stimulated devices are exposed to high humidity. A new innovative-patented design by Hamade, electrically stimulated catalytic converter (ESCC), eliminates such flaws and shows the wide practical applications of the new design. The new design utilized previous patented designs and work of the same inventor but retrofitted for catalytic auto exhaust emission control. The current and previous patents include: employing electrically stimulated filtration (ESF) to replace high efficiency particulate air (HEPA) filters, treatment of biological and infectious diseases, electret fabrication, and, most notably, the invention of a new electrically stimulated catalytic converter (ESCC). The electrically stimulated catalytic converter invention includes an exhaust conduit fed from the engine exhaust port with a housed corona charger apparatus. The opposite end is opened to the atmosphere outside of the vehicle or connected to a reduced-size catalytic converter. The corona charger is intrusively or non-intrusively associated with a main flow path defined by the exhaust conduit. The corona charger includes at least one electrode, which may be recessed away from, the main flow path. A plurality of corona chargers may be used in various combinations, optimally a two dimensional grid. The electrically stimulated catalytic converter is adapted to treat and eliminate auto exhaust pollution emission to air.

Fast quantification of fluoroquinolones in environmental water samples using molecularly imprinted polymers coupled with internal extractive electrospray ionization mass spectrometry.

In this study, a facile method based on molecularly imprinted polymers (MIPs) combined with internal extractive electrospray ionization tandem mass spectrometry (iEESI-MS/MS) was developed for the quantitative analysis of fluoroquinolones (FQs) in environmental water samples. FQ molecules in water samples were captured by the MIPs, which was retained on a 0.22 μm syringe filter. Then, an electrospray solution selected as the elution solution was employed to extract the FQs from the MIPs, getting an eluate of FQs for mass spectrometric interrogation. Under the optimized experimental conditions, low limits of detection (LODs, 0.015–0.026 μg L−1), with relative standard deviations (RSDs) less than 8.81% (n = 6) were obtained. The present method also provides good recoveries (91.14–103.60%) with acceptable precision (RSDs < 6.18%) and have no serious matrix effects for environmental water samples. The experimental results demonstrated that MIPs-iEESI-MS/MS has advantages including easy use, high speed (less than 3 min per sample) and high sensitivity for the analysis of FQs in environmental water samples, showing potential application in environmental science and water safety control.

A heavy metal module coupled with the SWAT model and its preliminary application in a mine-impacted watershed in China

Heavy metal behavior in soil and water requires modeling for a better understanding of the potential adverse impacts on the ecosystem as well as on humans. A heavy metal transport and transformation module is combined with the well-established SWAT (Soil and Water Assessment Tool) model for the purpose of simulating the fate and transport of metals at the watershed scale. The heavy metal module accounts for sorption, complexation and slow reactions among metal species; the heavy metals in the upland are allowed to transport vertically through percolation and evaporation-induced water rising as well as horizontally through soil erosion and surface/subsurface runoff; the heavy metals in the water body, in contrast, are modeled to undergo settling, resuspension, diffusion and burial processes. As a demonstration, the SWAT-laden heavy metal module (SWAT-HM) was calibrated to simulate zinc (Zn) and cadmium (Cd) dynamics in an upstream watershed of the Liuyang River in China, which has been impacted by mining activities for decades. The model simulations were found to agree reasonably well with the monitored results. In particular, the elevation of metal loads in channels with precipitation events was well represented, demonstrating that a considerable amount of Zn and Cd in the waste rock dumps and contaminated soil was released into rivers through rainfall. After a simulation of 6years (2009–2014), the simulated Zn and Cd concentrations were used as a surrogate for the Predicted Environmental Concentration (PEC), whereby an ecological risk assessment was conducted for the demonstrative mining area. This initiative toward developing a heavy metal module combined with SWAT has high potential for application in environmental risk analysis and pollution control.

Formation of organometallic microstructures via self-assembling of carboxylated zinc phthalocyanines with selective adsorption and visible light-driven photodegradation of cationic dyes

Self-assembled organometallic micro/nano-structures showing well-defined morphology and tunable functionality are receiving increasing interests for recent years. Herein, the flower- and rod-like organometallic micro/nano-structures have been constructed via a facile protonation-induced self-assembling of carboxylated zinc phthalocyanines (ZnPc carboxylate) at room temperature. Thanks to their hierarchical microstructures and active photosensitization feature, the formulated ZnPc micro/nano-structures exhibited simultaneous selective adsorption and visible light-driven photodegradation of cationic dye molecules, leading to a quite competitive removal capacity of methylene blue approaching to 80 mg g−1. Furthermore, the self-assembling of ZnPc micro/nano-structures was rationalized in terms of systematic characterization of their morphology evolution, crystalline structures, and optical properties. The ZnPc micro/nano-structures showing excellent adsorption capacity, photocatalytic degradation towards cationic dye molecules as well as the scalable fabrication will pave their way for future application in environmental remediation and water pollutants control.

Self-Diffusion Driven Ultrafast Detection of ppm-Level Nitroaromatic Pollutants in Aqueous Media Using a Hydrophilic Fluorescent Paper Sensor.

Development of fluorescent film probes for toxic nitroaromatic compound pollutants (NACs) such as 2,4,6-trinitrotoluene (TNT) in real water samples implies broad applications in environmental and industrial safety control. Despite many recent advances, there are still some difficult challenges facing this area, for example, the restricted sensitivity and long response time caused by hindered and slow diffusion of aqueous NACs samples inside a dense, solid film. Hence, we report herein a robust fluorescent paper sensor with improved sensing abilities, which is prepared by absorbing hydrophilic pyrene-functionalized polymer uniformly into cellulose-based filter papers. Thanks to the numerous oxygen-containing groups grafted on cellulose papers, they allow passive and ultrafast capillary force driving diffusion of aqueous NACs samples into their hydrophilic matrix. Specifically speaking, these paper sensors can offer efficient self-diffusion paths inside the test strips and immediately bring the pyrene fluorophores and NACs quenchers into close proximity. Therefore, the developed paper-based test strips enable both naked-eye detection of low-ppm-level TNT and ultrafast fluorescence quenching with a response time of only a few seconds, which are difficult to be achieved by conventional film probes.

A Multifunctional Brain-Computer Interface Intended for Home Use: An Evaluation with Healthy Participants and Potential End Users with Dry and Gel-Based Electrodes.

Current brain-computer interface (BCIs) software is often tailored to the needs of scientists and technicians and therefore complex to allow for versatile use. To facilitate home use of BCIs a multifunctional P300 BCI with a graphical user interface intended for non-expert set-up and control was designed and implemented. The system includes applications for spelling, web access, entertainment, artistic expression and environmental control. In addition to new software, it also includes new hardware for the recording of electroencephalogram (EEG) signals. The EEG system consists of a small and wireless amplifier attached to a cap that can be equipped with gel-based or dry contact electrodes. The system was systematically evaluated with a healthy sample, and targeted end users of BCI technology, i.e., people with a varying degree of motor impairment tested the BCI in a series of individual case studies. Usability was assessed in terms of effectiveness, efficiency and satisfaction. Feedback of users was gathered with structured questionnaires. Two groups of healthy participants completed an experimental protocol with the gel-based and the dry contact electrodes (N = 10 each). The results demonstrated that all healthy participants gained control over the system and achieved satisfactory to high accuracies with both gel-based and dry electrodes (average error rates of 6 and 13%). Average satisfaction ratings were high, but certain aspects of the system such as the wearing comfort of the dry electrodes and design of the cap, and speed (in both groups) were criticized by some participants. Six potential end users tested the system during supervised sessions. The achieved accuracies varied greatly from no control to high control with accuracies comparable to that of healthy volunteers. Satisfaction ratings of the two end-users that gained control of the system were lower as compared to healthy participants. The advantages and disadvantages of the BCI and its applications are discussed and suggestions are presented for improvements to pave the way for user friendly BCIs intended to be used as assistive technology by persons with severe paralysis.

Dispersion Characteristics and Sensitivity Properties of Graphene Surface Plasmon Sensor

In this work, dispersion characteristics and sensitivity of the propagation of TM surface plasmon through the proposed waveguide sensor. The proposed sensor containing a graphene at a finite distance filled with metamaterials (MTM) from plasmonic layer and sandwiched by dielectric layers. We numerically demonstrate the proposed waveguide structure as a novel graphene surface plasmons sensor. The obtained results can be useful for enhancing the sensitivity of plasmonic—graphene devices which could be used in further application in biosensing and environmental control.

Gradient-Hierarchic-Aligned Porosity SiOC Ceramics

This work describes a simple technique to produce porous ceramics with aligned porosity having very high permeability and specific surface area. SiOC-based compositions were processed from blends of three types of preceramic polymer and a catalyst, followed by curing and pyrolysis. The heating applied from the bottom of molds promoted the nucleation, expansion and rising of gas bubbles, and the creation of a ceramic matrix with axially oriented channels interconnected by small round pores. The samples were analyzed by SEM, tomography, BET, water immersion porosimetry and permeation to gas flow. The resulting bodies presented levels of open porosity (69.9–83.4%), average channel diameter (0.59–1.25 mm) and permeability (0.56–3.83 × 10−9 m2) comparable to those of ceramic foams and honeycomb monoliths, but with specific surface area (4.8–121.9 m2/g) typical adsorbents, enabling these lotus-type ceramics to be advantageously used as catalytic supports and adsorption components in several environmental control applications.

Green Synthesis of Iron Nanoparticles and Their Environmental Applications and Implications.

Recent advances in nanoscience and nanotechnology have also led to the development of novel nanomaterials, which ultimately increase potential health and environmental hazards. Interest in developing environmentally benign procedures for the synthesis of metallic nanoparticles has been increased. The purpose is to minimize the negative impacts of synthetic procedures, their accompanying chemicals and derivative compounds. The exploitation of different biomaterials for the synthesis of nanoparticles is considered a valuable approach in green nanotechnology. Biological resources such as bacteria, algae fungi and plants have been used for the production of low-cost, energy-efficient, and nontoxic environmental friendly metallic nanoparticles. This review provides an overview of various reports of green synthesised zero valent metallic iron (ZVMI) and iron oxide (Fe2O3/Fe3O4) nanoparticles (NPs) and highlights their substantial applications in environmental pollution control. This review also summarizes the ecotoxicological impacts of green synthesised iron nanoparticles opposed to non-green synthesised iron nanoparticles.

Polymer–Graphene Nanocomposite Materials for Electrochemical Biosensing

Biosensing is an important and rapidly developing field, with numerous potential applications in health care, food processing, and environmental control. Polymer-graphene nanocomposites aim to leverage the unique, attractive properties of graphene by combining them with those of a polymer matrix. Molecular imprinted polymers, in particular, offer the promise of artificial biorecognition elements. A variety of polymers, including intrinsically conducting polymers (polyaniline, polypyrrole), bio-based polymers (chitosan, polycatechols), and polycationic polymers (poly(diallyldimethylammonium chloride), polyethyleneimine), have been utilized as matrices for graphene-based nanofillers, yielding sensitive biosensors for various biomolecules, such as proteins, nucleic acids, and small molecules.

Hazardous aromatic VOC quantification through spectroscopic analysis and intelligent modeling to assess drinking water quality

Concentrations within the micromole range have been accurately determined for mixtures of two common aromatic volatile organic compounds (VOCs) that are hazardous for both the environment and human health: styrene and 1,2,4-trimethylbenzene. This task has been developed by combining 165 UV/Vis absorption measurements and intelligent modeling based on artificial neural networks (ANNs), and is especially relevant as these compounds have been located in sources of drinking water within the concentration range covered. The performance of the designed non-linear models proves the existence of a relation between spectroscopic information and compound concentration, as well as the ability to obtain reliable quantifying chemometric tools for environmental control applications. The average mean absolute errors for three internal validations were near 0.5μM and 1.5μM for styrene and 1,2,4-trimethylbenzene concentration estimation, respectively.

Highly sensitive SnO2 sensor via reactive laser-induced transfer.

Gas sensors based on tin oxide (SnO2) and palladium doped SnO2 (Pd:SnO2) active materials are fabricated by a laser printing method, i.e. reactive laser-induced forward transfer (rLIFT). Thin films from tin based metal-complex precursors are prepared by spin coating and then laser transferred with high resolution onto sensor structures. The devices fabricated by rLIFT exhibit low ppm sensitivity towards ethanol and methane as well as good stability with respect to air, moisture, and time. Promising results are obtained by applying rLIFT to transfer metal-complex precursors onto uncoated commercial gas sensors. We could show that rLIFT onto commercial sensors is possible if the sensor structures are reinforced prior to printing. The rLIFT fabricated sensors show up to 4 times higher sensitivities then the commercial sensors (with inkjet printed SnO2). In addition, the selectivity towards CH4 of the Pd:SnO2 sensors is significantly enhanced compared to the pure SnO2 sensors. Our results indicate that the reactive laser transfer technique applied here represents an important technical step for the realization of improved gas detection systems with wide-ranging applications in environmental and health monitoring control.

Construction and analysis of an intergeneric fusion from Pigmentiphaga sp. strain AAP-1 and Pseudomonas sp. CTN-4 for degrading acetamiprid and chlorothalonil.

Pseudomonas sp. CTN-4 degrades chlorothalonil (CTN) but not acetamiprid (AAP), and Pigmentiphaga sp. strain AAP-1 degrades AAP but not CTN. A functional strain, AC, was constructed through protoplast fusion of two parental strains (Pseudomonas sp. CTN-4 and Pigmentiphaga sp. strain AAP-1) in order to simultaneously improve the degradation efficiency of AAP and CTN. Fusant-AC with eight transfers on plates containing two antibiotics and CTN was obtained. For the purpose of identifying and confirming the genetic relationship between fusant-AC and its parents, randomly amplified polymorphic DNA (RAPD), scanning electron microscopy (SEM), and 16S ribosomal DNA (rDNA) analysis were performed. In toto, RAPD fingerprint analysis produced 194 clear bands with 9 primers, which not only had bands in common with strains CTN-4 and AAP-1, but also had its own novel fusant-specific bands. The genetic similarity indices between fusant-AC and parental strains CTN-4 and AAP-1 were 0.40 and 0.69, respectively. The result of SEM indicated that the cell morphology of fusant-AC differed from both its parents. The fusant strain AC possesses a strong capability for AAP and CTN degradation. At AAP concentration (50-300mgL(-1)), the degradation was achieved within 5h. At the initial dose of 50 and 100mgL(-1) CTN, the percentages reached 96 and 91% over a 36-h incubation period. The present study indicates that the protoplast-fusion technique may have possible applications in environmental pollution control.

Issues and mitigation of interference, attenuation and direction of arrival in IEEE 802.15.4/ZigBee to wireless sensors and networks based smart building

The performance metrics of IEEE 802.15.4 standard make it an only dominant option in short-range environmental monitoring and control applications. The heterogeneous sensor and actuator nodes based on the wireless technology are deployed into the smart building environment. Wireless technology deployed in building environment suffers from interference from different communication protocols operating in the same unlicensed ISM band, apart from the attenuation loss. A designer could not ignore these factors in the smart building because the adverse effect of these issues on system performance is considerable. Most of the researchers reported this but not with the aspects of the smart building. This research paper reports on the detailed experimental analysis and mitigation for different types of interference, the direction of arrival and attenuation losses associated with smart building condition. This research also tries to find the mitigation by direction of arrival of the radio signal. Our research aims to generate the customized methodology that will support and assist the smart building system designer to evaluate and measure the on-site performance so that these assessments will be precise, efficient and accurate. A realistic, smart home solution is applied to the building.