Maximum Index Value Research Articles

Strain self-sensing capability of a tidal turbine blade fabricated of PU-foam/glass fiber/epoxy composites using MWCNTs

A novel marine composite structure (experimental tidal turbine blade) made up of a polyurethane (PU) foam/glass fiber/epoxy resin composite with multiwall carbon nanotubes (MWCNTs) is proposed herein to self-sense its strain under a structural test scenario. To achieve this, MWCNTs were deposited onto glass fiber fabric by spray-coating technique in order to form an effective electrical percolation network onto the external skin surface of the tidal turbine blade which enables piezoresistive capability. After MWCNT deposition, the blade was manufactured by means of one-shot resin transfer molding (RTM) in a closed and heated metallic mold specially designed with a blade geometry of 67 cm length. The results confirm that the spray coating technique is a viable method to deposit MWCNTs onto glass fiber surface and form electrical networks into the blade at a relatively low MWCNT concentration. Finite element analysis (FEA) predicted a suitable structural blade design with a maximum failure index value of 0.9 attained in the blade shear web. The measured longitudinal strains of the tidal turbine blade were in good agreement with the numerical strain values predicted with FEA. Electromechanical tests carried out on a structural test rig designed and instrumented for tidal turbine blades showed that the electrical resistance change response of carbon nanotube (CNT) network integrated into the blade was capable of following the mechanical curve response up to the blade limit load, confirming its ability to self-sense its strain in real time.

Pilot Study of Pollution Characteristics and Ecological Risk of Disinfection Byproducts in Natural Waters in Hong Kong.

Increased disinfection efforts in various parts of China, including Hong Kong, to prevent the spread of the novel coronavirus may lead to elevated concentrations of disinfectants in domestic sewage and surface runoff in Hong Kong, generating large quantities of toxic disinfection byproducts. Our study investigated the presence and distribution of four trihalomethanes (THMs), six haloacetic acids (HAAs), and eight nitrosamines (NAMs) in rivers and seawater in Hong Kong. The concentrations of THMs (mean concentration: 1.6 µg/L [seawater], 3.0 µg/L [river water]), HAAs (mean concentration: 1.4 µg/L [seawater], 1.9 µg/L [river water]), and NAMs (mean concentration: 4.4 ng/L [seawater], 5.6 ng/L [river water]) did not significantly differ between river water and seawater. The total disinfection byproduct content in river water in Hong Kong was similar to that in Wuhan and Beijing (People's Republic of China), and the total THM concentration in seawater was significantly higher than that before the COVID‐19 pandemic. Among the regulated disinfection byproducts, none of the surface water samples exceeded the maximum index values for THM4 (80 μg/L), HAA5 (60 μg/L), and nitrosodimethylamine (100 ng/L) in drinking water. Among the disinfection byproducts detected, bromoform in rivers and seawater poses the highest risk to aquatic organisms, which warrants attention and mitigation efforts. Environ Toxicol Chem 2022;41:2613–2621. © 2022 SETAC

Characterization of the chemical shift and asymmetry indices of praseodium, neodymium, samarium, gadolinium, and terbium compounds by wavelength dispersive X-ray fluorescence (WDXRF)

Emitted X-ray energies, line shapes, fluorescence yields, absorption probabilities and absorption edges of the elements are X-ray fundamental parameters that are of practical significance because they facilitate compositional analysis of complex materials. They are also a potent test of atomic theory. The chemical effects may cause changes in the energy of the X-ray lines and line shapes, such as the full width at half maximum and asymmetry index values depending on the chemical state of the substance. Although these effects vary for each element, the causes of these differences have been investigated. In this study, changes in chemical action values of lanthanide group compounds were investigated using a single crystal wavelength dispersive X-ray spectrometer equipped with a rhodium anode X-ray tube. The Ll and Lη X-ray emission lines are characterized by fitting of the Lorentz function. The chemical shift was investigated according to the chemical bond type, molecular structure, and oxidation number.

A comparison of conventional and oxidative torrefaction of microalga Nannochloropsis Oceanica through energy efficiency analysis and life cycle assessment

Torrefaction is a promising method for producing microalgal solid biofuel. This study compared conventional torrefaction and oxidative torrefaction for microalgal solid biofuel production. Particular attention was paid to evaluating energy efficiency analysis and life cycle assessment, and several parameters and indexes were adopted and calculated. The results showed that mild oxidative torrefaction was the most energy-efficient operation, with the maximum value of relative upgrading energy index and relative energy return on investment. The life cycle assessment indicates that oxidative torrefaction had a lower environmental impact than conventional torrefaction, mainly due to its lower carrier gas consumption and electricity input. The environmental impact positively correlated with the torrefaction severity. The obtained results in this study can provide new insights on improving the cognition of energy efficiency evaluation and environmental impact assessment of the torrefaction process, which helps select optimal torrefaction conditions.

Multifractal Features of Particle-Size Distribution and Their Relationships With Soil Erosion Resistance Under Different Vegetation Types in Debris Flow Basin

Understanding the influence of vegetation types on soil particle-size distribution (PSD) is essential to evaluate the effects of sediment control by vegetation restoration. In this work, we studied the effects of different vegetation types, including bare land, meadow, shrub and forest on soil PSD in Jiangjiagou gully, Yunnan province, China. A total of 60 soil samples were collected and analyzed for soil particle size distribution using the laser diffraction method. Fractal theory was used to calculate multifractal parameters. The volume fraction of silt particles in shrub and forest is significantly higher than that in bare land, meadow, whereas the total volume fraction of sand particles in bare land and meadow exceed that in shrub and forest. The soil particle size distribution along soil layers has no significant difference in each vegetation type. The volumetric fractal dimension is significantly higher in forest and shrub than in bare land and grassland, but there is no significant difference between forest and shrub. In addition, soil erosion resistance exhibits significant differences of forest > shrub > grassland > bare land. Multifractal parameters are highest in bare land except for multifractal spectrum values (f (αmax) and f (αmin)) and the maximum value of singularity index (αmin). All generalized dimensions spectra curves of the PSD are sigmoidal, whereas the singular spectrum function shows an asymmetric upward convex curve. Furthermore, soil erosion resistance has significant relationships with multifractal parameters. Our results suggest that multifractal parameters of the soil PSD can predict its anti-ability to erosion. This study also provides an important insight for the evaluation of soil structure improvement and the effects of erosion control by vegetation restoration in dry-hot valley areas.

The Role of Sea State to the Morphological Changes of Prasonisi Tombolo, Rhodes Island, Greece

Wave-induced morphodynamic processes that cause formation, preservation, and destruction of the Prasonisi tombolo in Rhodes Island are investigated, based on satellite image analysis and numerical modeling. A new method is developed for extracting wave events that consist of successive wave data of similar characteristics. The wave events refer either to wind seas or swell seas. This process combined with the satellite image analysis is then utilized for the derivation of the most representative wave scenarios that affect tombolo and salient formation. In particular, the main factors that play a significant role in tombolo and salient evolution are the offshore wave conditions, the location and width of the surf zone, the maximum value of the wave breaking index in the study area, and the initial bottom bathymetry before the study area is exposed to a new sea state. In general, the proposed method provides a realistic insight into tombolo morphodynamics and can be used to provide a cost-effective approach and a wave data-reduction technique for coastal engineering studies.

Characteristics of subway air quality and favorable locations for passengers waiting and taking the subway

With the increase of commuters in Beijing subway, the air quality inside subway systems has caused widespread apprehension. The particulate matter (PM) level and potential health risk of PM on the platforms and carriages of Open (O) system, Half-height platform door (HPD) system, Full-height platform door (FPD) system, Platform screen door (PSD) system were studied. The average PM2.5 concentration was approximately twice the Chinese National Ambient Air Quality Standard Class II threshold and ten times the WHO Global Air Quality Guidelines. The average PM2.5 and PM10 ratios on the platform and inside carriages were 0.81 and 0.85, respectively. Compared to the FPD and HPD, the PSD has the highest ability to prevent tunnel dust entering the platform, whereas, the FPD's preventive ability is insignificant. The maximum comprehensive indoor-air quality index (CIAI) values for platform PM2.5 and PM10 are at a very unhealthy risk level and unhealthy risk level, respectively. The average PM2.5 doses deposited by adult males in extrathoracic (ET), tracheobronchial (TB) and alveolar-interstitial (AI) during a day's round-trip ride were 163.7 μg, 9.6 μg and 24.1 μg, respectively. The PM concentration at the station platform nearer to the entrance location is greater than the middle of the platform and the center of the station hall. The PM concentration at the middle of the carriage between two doors is lower than that at the door. The research results have important guidance for constructing a subway environmental control system, station passenger flow command desk setting, passenger waiting and taking the subway to reduce the health risk.

Insight into the physicochemical, structural, and in vitro hypoglycemic properties of bamboo shoot dietary fibre: comparison of physical modification methods

SummaryThe effects of high‐temperature cooking (HTC), high‐pressure homogenisation (HPH), ultrasonic treatment (UT), and their combination (i.e., UT–HTC, HPH–HTC, and UT–HPH) on the physicochemical, structural, and in vitro hypoglycemic properties of bamboo shoot dietary fibres (BSDF) were investigated and compared. The soluble dietary fibre, arabinose, and glucose contents increased in all modified samples. The BSDF obtained by UT had a loose structure with a honeycomb appearance on the surface. UT–HTC resulted in the highest water‐holding capacity (8.38 g g−1) and α‐amylase activity inhibition ratio (56.14%). The BSDF modified by HPH–HTC had the lowest relative crystallinity (27.96%). Compared with those of control check (CK), the oil‐holding and swelling capacities of samples treated by UT–HPH increased by 55.35% and 91.47%, respectively. The glucose adsorption capacity of samples followed the order: UT–HTC > UT–HPH > HPH–HTC > HPH > UT ≈ HTC. Furthermore, the maximum glucose dialysis retardation index values of BSDF treated by UT–HPH, HPH, and HPH–HTC increased by 44.51%, 30.61%, and 27.20%, respectively, in comparison with CK. This study indicated that UT–HTC, HPH–HTC, and UT–HPH are innovative and promising modification methods to obtain BSDF with excellent physicochemical and functional properties.

Different Effects of Cigarette Smoke, Heated Tobacco Product and E-Cigarette Vapour on Orbital Fibroblasts in Graves' Orbitopathy; a Study by Real Time Cell Electronic Sensing.

Thyroid autoimmunity in Graves’ disease (GD) is accompanied by Graves’ orbitopathy (GO) in 40% of the cases. Orbital fibroblasts (OF) play a key role in the pathogenesis and cigarette smoking is a known deteriorating factor. Alongside conventional cigarettes (CC) new alternatives became available for smokers, including heated tobacco products (HTP) and E-cigarettes (ECIG). We aimed to study the cellular effects of smoke extracts (SE) in orbital fibroblasts. Primary OF cultures from GO and NON-GO orbits were exposed to different concentrations of SE (1%, 50%) and the changes were followed using Real Time Cell Electronic Sensing (RT-CES). Untreated GO and NON-GO cells had different maximum cell index (CI) values of 3.3 and 2.79 respectively (p < 0.0001). CC, HTP and ECIG treated NON-GO fibroblasts exhibited peak CIs of 2.62, 3.32 and 3.41 while treated GO cells’ CIs were higher, 5.38, 6.25 and 6.33, respectively (p < 0.0001). The metabolic activity (MTT) decreased (p < 0.001) and hyaluronan production doubled (p < 0.02) after 50% of CC SE treatment in all cell cultures. GO fibroblasts were more sensitive to low concentration SE then NON-GO fibroblasts (p < 0.0001). The studied SEs exerted different effects. RT-CES is a sensitive technique to detect the effects of very low concentration of SE on fibroblasts.

Automation Reduces Human Error in Influx Detection and Well Control

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 208784, “Reducing Human Error Through Automatic Kick Detection, Space Out, and Dynamic Well Monitoring,” by Francesco Curina, Elia Abdo, SPE, and Hadi Mustapha, SPE, Drillmec. The paper has not been peer reviewed. Influx detection and well control are critical situations where the traditional human reaction has been the accepted standard for years. This paper discusses the results of the driller stress tests and the implementation of a system to assist the operator in kick detection, space out, and preparation for well shut-in. The system implements dynamic well monitoring to reduce the risk of false alarms. The objective is to prove how automation helps mitigate human factors. Operator Stress Test To design an automation system, the first step is to understand which parts of the operation require automation. To do this, a stress test was conducted on a number of drillers to identify periods during well control where stress levels were higher than usual. The indices used were based on two parameters: the body temperature and the sudomotor activity. The two parameters can be used to assign a stress index for the operator. The operators were tested using a well-control simulator and an internationally recognized standard well-control exercise. The test procedure was as follows: The operator would start performing a standard drilling operation while monitoring parameters. Once the kick occurs, the driller should be able to identify it using the correct parameters, perform a space out operation, and shut down the equipment. He should then, perform a flow check, and, if the check is positive, he should shut in the well. In one representative test, the operator was not able to instantaneously identify the influx. Once he did identify the kick, his stress levels increased, hitting the maximum stress index value of five (5). The period of relatively low stress that followed is a natural physiological reaction that usually occurs after a shocking event. During this stretch of time, the operator did not yet move to mitigate the situation. The operator then proceeded to conduct a space out per standard procedure. The constantly high stress level seen during the space out operation confirms a previously proposed theory that this operation is accompanied by a wide margin for errors and a high risk factor. With the space out completed, the operator stopped the rotation of the drill string, shut off the pumps, and conducted a flow check. Then he proceeded to shut in the well by closing the annular blowout preventer (BOP). In this specific trial, the annular BOP was configured to develop a leak. When the operator activated the annular BOP and proceeded with a flow check, the stress levels increased for a short duration while he was analyzing the parameters. The operator understood the faulty BOP element and proceeded to close the second element. In this case, the operator correctly performed the procedure; however, it took him some time to reach a conclusion and perform the needed process. The results of the tests clearly identify two moments where the driller either made mistakes, had a slow reaction time, or had a decreased clarity of mind caused by high level of stress.

A study on wheat crop for estimation of potassium efficiency, effect on growth, potential yield under agricultural and botanical practices

Wheat (Triticum aestivum L.) is one of the important crops of human diet around the globe. Purify flour of wheat contains less vitamins and causes constipation and malnourishment. The experiment was designed to study on wheat crop, botanical and agricultural parameters and advances in plant sciences and accomplished in Randomized Complete Block Design. Sowing was done in field with plot size of 216 m2. LAI is very crucial growth index which directly controls the interception of solar radiation and consequently dry matter production and accumulation. The LAD exhibits the tenacity of leaves to remain photo synthetically active during the growth season of a crop. The NAR indicates the dry matter accumulation in plants per unit canopy area. Recorded data was subjected to analysis of variance by using Statistix 8.1 software. It presented mean values of all treatments for crop growth rate. Maximum results for CGR observed under T3 with 14.3 mean values. While minimum observations had been shown by T1 that is 13.4. It showed mean values for all applied treatments and wheat showed maximum value of leaf area index of (3.3367) under treatment (T4) and minimum value of leaf area index that is 3.0233 was shown by plants under treatment (T7). Maximum results for flag leaf area observed under T4 with 114.73 mean values. While minimum observations had been shown by T1 that is 88.03. It is recommended that the farmers should use split dose of potassium fertilizer for better growth and yield of wheat and it may also be helpful in future prospects.

A quantitative structure activity relationship (QSAR) model for predicting the rate constant of the reaction between VOCs and NO3 radicals

NO3 radical is one of the important oxidants used for the chemical degradation of Volatile organic compounds (VOCs). Thus, the derivation of rate constant (kNO3) is critical to understand the removal kinetics of VOCs. To better estimate the kNO3, a quantitative structure activity relationship (QSAR) model was established using the kNO3 of 189 VOCs and quantum chemical parameters. The optimal QSAR model can predict the kNO3 with its R2, q2, and Qext2 being 0.880, 0.872, and 0.861, respectively. The QSAR analysis results indicate that the energy of the highest occupied molecular orbital (EHOMO) and the maximum value of electrophilic Fukui index (f(−)x) are two intrinsic factors determining the kNO3. Additionally, the analysis of the correlation between kNO3 values and quantum chemical parameters shows that the gap energy between LUMO and HOMO (EGAP), the minimum value of free radical Fukui index (f (0)n), and the maximum value of bond order (BOx) also significantly affect kNO3. The validations of the optimal QSAR model confirm the high realizability, stability and accuracy, and the wide applicability of the derived model for predicting kNO3.

Ecological study of zooplankton in the Shatt Al-Basrah canal, Basrah-Iraq

Seasonal abundance and distribution of Zooplankton were studied at three stations in the Shatt Al-Basrah canal, during the period from 2 April 2011 to 2 January 2012. The lowest value of zooplankton density recorded was 5 ind./m3 at station one in winter 2012, and the highest was 621200 ind./m3 at station three in spring 2011. Rotifera were dominated the zooplankton community (55%), followed by Copepoda (27%) then by Cirripede larvae (13%). Water temperatures, salinity, pH, dissolved oxygen and turbidity were measured at each station, as well as some ecological indices were calculated. Water temperature ranged from 12 to 33.2 ºC at stations one and three, respectively. Salinity values changed from 15.6 to 35.1 psu at stations one and three respectively with a decline in spring and an increase in summer. pH values were on the alkaline side, dissolved oxygen varied from 2.53 to 8.7 mg/l in spring and autumn at stations three and one, respectively. The maximum diversity index value was 0.7 at station one, richness index values was 0.54 at station three and evenness index value was 0.87 at station two. Higher similarity was obtained between stations 1 and 3 and lower value recorded between stations 2 and 3.

Hydrothermal and Second Law Analyses of Fluid Flow in Converging-Diverging (Hourglass) Microchannel

A three-dimensional numerical investigation is carried out to understand the mechanism of hydrothermal performance and second law analysis for a flow through converging-diverging (hourglass) microchannel. The fluid flow and convective heat transfer characteristics are investigated as a function of convergence-divergence angle, width ratio (ratio of bigger width to smaller width), and Reynolds number. The present study uses various parameters such as performance evaluation index, entropy generation, Bejan number, and augmented entropy generation number to examine the hydrothermal and thermodynamic performance characteristics of an hourglass microchannel. The parametric analysis reveals that the Nusselt number increases with an increase in convergence-divergence angle; however, it decreases with an increase in width ratio. Increasing the convergence-divergence angle effectively reduces the overall temperature gradient, whereas the width ratio has an opposite effect. The results also indicate that the hourglass microchannel shows better hydrothermal and thermodynamic performance than the uniform microchannel. For a given range of parameters, the maximum value of the performance evaluation index is 1.34, and the maximum reduction in entropy generation is 28% relative to a uniform microchannel. The findings obtained in this study may serve as a valuable roadmap for designing an hourglass microchannel in diverse heat transfer applications.

Ultrasound Features to Differentiate COVID-19 Vaccine-Induced Benign Adenopathy from Breast Cancer Related Malignant Adenopathy

Rationale and ObjectiveTo identify nodal features used to distinguish coronavirus disease 2019 (COVID-19) vaccine-Induced benign reactive adenopathy from malignant adenopathy.Materials and MethodsThis IRB-approved, single-institution, retrospective study compared features of 77 consecutive patients with benign adenopathy secondary to a messenger RNA COVID-19 vaccine with 76 patients with biopsy-proven malignant adenopathy from breast cancer. Patient demographics and nodal features were compared between the two groups using univariate and multivariate logistic regression models. A receiver operating characteristic analysis with the maximum value of Youden's index was performed for the cutoff value of cortical thickness for predicting nodal status.ResultsThe mean cortical thickness was 5.1 mm ± 2.8 mm among benign nodes and 8.9 mm ± 4.5 mm among malignant nodes (p < 0.001). A cortical thickness ≥3.0 mm had a sensitivity of 100% and a specificity of 21% (area under the curve [AUC] = 0.60, 95% confidence interval [CI]: 0.52-0.68). When the cutoff for cortical thickness was increased to ≥5.4 mm, the sensitivity decreased to 74%, while the specificity increased to 69% (AUC = 0.77, 95% CI: 0.70-0.84).Cortical thickness correlated with nodal morphology type (r2 = 0.57). An axillary node with generalized lobulated cortical thickening had a 7.5 odds ratio and a node with focal cortical lobulation had a 123.0 odds ratio compared to one with diffuse, uniform cortical thickening only (p < 0.001).ConclusionCortical thickness and morphology are predictive of malignancy. Cortical thickness cutoff of ≥5.4 mm demonstrates higher specificity and improved accuracy for detecting malignant adenopathy than a cutoff of ≥3.0 mm.

A sustainable approach to the development of highly degradable packaging films of pectin/guar gum/polyvinyl pyrrolidone: Thermal, biodegradation, and mechanical studies with statistical optimization

AbstractThe use of synthetic packaging materials and mulch films has retrogressive environmental effects. To replace these synthetic materials, high strength biodegradable polymer blends are synthesized using pectin, guar gum and polyvinyl pyrrolidone (PVP). The ternary blends are prepared with guar gum (10%–50%) and PVP (30%–50%), using the solvent casting technique. The experimentation is carried out using a 5 × 3 factorial design and analyzed by response surface methodology. Analysis of variance test is applied to analyze the ultimate tensile strength (UTS) and elongation at break and their simultaneous optimization is done by the desirability index method. The maximum desirability index value (0.877) is achieved at a guar gum content of 50% and PVP content of 41.73%. At this composition, the estimated value of UTS is 24.57 MPa and elongation at break is 27.29%. The thermal stability of the blends is almost similar and they are stable up to 170°C. Initial biodegradation (upto 30 days) of blends increases by 54.82% for samples with higher PVP content and decreases by 43.60% with the increase in guar gum content. All the blends are degraded completely within 90 days. The high tensile properties, sustained thermal stability and complete biodegradation of blends enable these for applications like packaging and agriculture mulch films.

Implantable Cardioverter Defibrillator Multisensor Monitoring during Home Confinement Caused by the COVID-19 Pandemic.

Simple SummaryDuring the COVID-19 pandemic, utilization of remote monitoring platforms was recommended. The HeartLogic algorithm identifies patients at risk of heart failure events, combining multiple sensors available on implantable cardioverter defibrillators. This analysis examined how multiple CIED sensors behave in periods of anticipated restrictions pertaining to physical activity. We demonstrated a significant drop in median activity level immediately after the implementation of stay-at-home orders, whereas there was no difference in the other contributing sensors. The weekly rate of heart failure alerts was significantly higher during the lockdown and post-lockdown than that reported in the pre-lockdown. Aims: The utilization of remote monitoring platforms was recommended amidst the COVID-19 pandemic. The HeartLogic index combines multiple implantable cardioverter defibrillator (ICD) sensors and has proved to be a predictor of impending heart failure (HF) decompensation. We examined how multiple ICD sensors behave in the periods of anticipated restrictions pertaining to physical activity. Methods: The HeartLogic feature was active in 349 ICD and cardiac resynchronization therapy ICD patients at 20 Italian centers. The period from 1 January to 19 July 2020, was divided into three phases: pre-lockdown (weeks 1–11), lockdown (weeks 12–20), post-lockdown (weeks 21–29). Results: Immediately after the implementation of stay-at-home orders (week 12), we observed a significant drop in median activity level whereas there was no difference in the other contributing parameters. The median composite HeartLogic index increased at the end of the Lockdown. The weekly rate of alerts was significantly higher during the lockdown (1.56 alerts/week/100 pts, 95%CI: 1.15–2.06; IRR = 1.71, p = 0.014) and post-lockdown (1.37 alerts/week/100 pts, 95%CI: 0.99–1.84; IRR = 1.50, p = 0.072) than that reported in pre-lockdown (0.91 alerts/week/100 pts, 95%CI: 0.64–1.27). However, the median duration of alert state and the maximum index value did not change among phases, as well as the proportion of alerts followed by clinical actions at the centers and the proportion of alerts fully managed remotely. Conclusions: During the lockdown, the system detected a significant drop in the median activity level and generated a higher rate of alerts suggestive of worsening of the HF status.

Multiple power quality disturbances analysis in photovoltaic integrated direct current microgrid using adaptive morphological filter with deep learning algorithm

In this paper, an adaptive multiscale enhanced average combination morphological filter is proposed to analyze voltage signals captured at the point of common coupling of the photovoltaic integrated direct current microgrid for diagnosing several power quality disturbances. This method performs multiscale operation on the power quality disturbance signals from which the optimized structuring element scales are chosen by using maximum value of sparse envelope kurtosis index. Further, statistical features are extracted by using optimized scales. The extracted features are used as inputs to a deep stacked extreme leaning machine autoencoder to retrieve the most distinguishable unsupervised features and these features are processed through kernel random vector functional link network based supervised classifier to classify the power quality disturbances. Further, to improve the classification performance of the proposed technique, a meta heuristic chaotic particle swarm optimization integrated with sine cosine optimization algorithm is used. This optimization algorithm optimizes the kernel parameters by minimizing the mean absolute error. The efficacy of the proposed technique is tested in terms of classification accuracy and confusion matrix and is verified by multifunction high-speed national instrument device for monitoring of power quality disturbances in the MATLAB/Simulink platform. The simulations and hardware results demonstrate that the proposed technique exhibits remarkable accuracy, faster training time and low computational complexity as compared with other existing methods.

Study of hydrothermal transport phenomena and performance characteristics for a flow through a diamond (diverging-converging) microchannel

A three-dimensional computational module is undertaken to assimilate the hydrothermal transport phenomena and performance characteristics of a single-phase laminar flow through a diamond (diverging-converging) microchannel. The fluid flow and heat transfer characteristics are investigated as a function of divergence-convergence angle, width ratio (ratio of bigger width to smaller width), and Reynolds number. The results are explained with the help of velocity and temperature profiles. The present study also utilizes thermal enhancement factor, pressure penalty factor, performance evaluation index, frictional and thermal entropy generation, Bejan number, and augmented entropy generation number to analyze the hydrothermal and thermodynamic performance characteristics of a diamond microchannel. The Nusselt number is found to be a direct function of the divergence-convergence angle, while it varies inversely with the width ratio. The varying divergence-convergence angle effectively constrains the rise in the overall temperature gradient, while the width ratio has a weak but opposite effect on the temperature gradients. The results also indicate that the diamond microchannel exhibits better hydrothermal and thermodynamic performance than the uniform microchannel. For a given range of parameters, the maximum value of the performance evaluation index is 1.42, and the maximum reduction in entropy generation is 28% relative to a uniform microchannel. These results would serve as a valuable guide for designing and optimizing microchannels with diverging-converging profiles required in several heat transfer applications.

Remote Sensing Mapping of Peat-Fire-Burnt Areas: Identification among Other Wildfires

Peat fires differ from other wildfires in their duration, carbon losses, emissions of greenhouse gases and highly hazardous products of combustion and other environmental impacts. Moreover, it is difficult to identify peat fires using ground-based methods and to distinguish peat fires from forest fires and other wildfires by remote sensing. Using the example of catastrophic fires in July–August 2010 in the Moscow region (the center of European Russia), in the present study, we consider the results of peat-fire detection using Terra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) hotspots, peat maps, and analysis of land cover pre- and post-fire according to Landsat-5 TM data. A comparison of specific (for detecting fires) and non-specific vegetation indices showed the difference index ΔNDMI (pre- and post-fire normalized difference moisture Index) to be the most effective for detecting burns in peatlands according to Landsat-5 TM data. In combination with classification (both unsupervised and supervised), this index offered 95% accuracy (by ground verification) in identifying burnt areas in peatlands. At the same time, most peatland fires were not detected by Terra/Aqua MODIS data. A comparison of peatland and other wildfires showed the clearest differences between them in terms of duration and the maximum value of the fire radiation power index. The present results may help in identifying peat (underground) fires and their burnt areas, as well as accounting for carbon losses and greenhouse gas emissions.