Analytical Frequency Research Articles

3D-printed electrochemical platform with multi-purpose carbon black sensing electrodes.

The 3D printing is described of a complete and portable system comprising a batch injection analysis (BIA) cell and an electrochemical platform with eight sensing electrodes. Both BIA and electrochemical cells were printed within 3.4 h using a multimaterial printer equipped with insulating, flexible, and conductive filaments at cost of ca. ~ U$ 1.2 per unit, and their integration was based on a threadable assembling without commercial component requirements. Printed electrodes were exposed to electrochemical/Fenton pre-treatments to improve the sensitivity. Scanning electron microscopy and electrochemical impedance spectroscopy measurements upon printed materials revealed high-fidelity 3D features (90 to 98%) and fast heterogeneous rate constants ((1.5 ± 0.1) × 10−3 cm s−1). Operational parameters of BIA cell were optimized using a redox probe composed of [Fe(CN)6]4−/3− under stirring and the best analytical performance was achieved using a dispensing rate of 9.0 µL s−1 and an injection volume of 2.0 µL. The proof of concept of the printed device for bioanalytical applications was evaluated using adrenaline (ADR) as target analyte and its redox activities were carefully evaluated through different voltammetric techniques upon multiple 3D-printed electrodes. The coupling of BIA system with amperometric detection ensured fast responses with well-defined peak width related to the oxidation of ADR applying a potential of 0.4 V vs Ag. The fully 3D-printed system provided suitable analytical performance in terms of repeatability and reproducibility (RSD ≤ 6%), linear concentration range (5 to 40 µmol L−1; R2 = 0.99), limit of detection (0.61 µmol L−1), and high analytical frequency (494 ± 13 h−1). Lastly, artificial urine samples were spiked with ADR solutions at three different concentration levels and the obtained recovery values ranged from 87 to 118%, thus demonstrating potentiality for biological fluid analysis. Based on the analytical performance, the complete device fully printed through additive manufacturing technology emerges as powerful, inexpensive, and portable tool for electroanalytical applications involving biologically relevant compounds.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s00604-022-05323-4.

Flood Hazard Assessment of the Bangshi River Floodplain using an Integrated 1D/2D Coupled Hydraulic Model

In the present study, the flood hazard of the Bangshi River, located in the Savar Industrial Area of Dhaka District, has been evaluated. The historical flood extent analysed from the Landsat satellite images suggests that most parts of the study area were flooded during the major flood events in Bangladesh. The flood flow data were fitted with different analytical frequency distribution functions, and it is found that the Pearson III distribution function best fits with the observed data based on the Chi-Squared statistical test. Then, the flood flow model of the Bangshi River as well as the surrounding floodplain area was developed using the HEC-RAS 1D-2D coupled hydraulic model. The model was simulated with an estimated flow of 100-year and 500-year return periods. The analysis of the historical flood data shows that the water level exceeds the danger level at the nearby monitoring station of the study area in different years. In the study area, devastating floods occurred in the years 1988 and 1998. The maximum flood level was 9.9 m during the flood event of 1988. The analysis of Landsat satellite images also shows that about 69% and 58% of the study area were flooded during the floods of 1988 and 1998, respectively. The roadways provide flood protection barriers in the western side of the study area for the flood water coming from the Bangshi River system unless the road is overtopped. The simulated result shows that about 68% and 79% of the study area will be inundated for the 100-year and 500-year return periods, respectively. The simulated maximum flood velocity for the 100-year and 500-year return period is 2.31 m/s and 4.52 m/s, and the flood duration for the same return periods is about 32.5 days and 48.95 days, respectively. The simulated flood depth, duration, and velocity maps can be used for any development activities within the study area. The Dhaka University Journal of Earth and Environmental Sciences, Centennial Special Volume June 2022: 167-186

An analytical approach to design horns and boosters of ultrasonic welding machines

This paper presents a new design approach for two main components of an ultrasonic plastic welding machine, booster and horn, based on an analytical model. The design procedure is developed due to the lack of a comprehensive and precise analytical model for rapid design and analysis of these components. The previous analytical models use the one-dimensional wave equation that causes significant errors in designing components with large lateral dimensions. Three-dimensional vibrations are considered for developing an analytical model using the apparent elasticity method. In this way, longitudinal frequency equations are coupled with radial frequency equations by mechanical coupling coefficients. Also, the damping of materials is taken into account. The model can be adapted to calculate the resonant length of the components or calculate the resonant frequency. To verify the model, the results are compared to a numerical simulation. The difference between analytical and numerical resonance frequency is less than 0.02%. Moreover, an experimental modal analysis is performed, which shows 0.9% error with analytical results.Article highlightsA new design approach for boosters and horns has been developed based on an analytical model.Three-dimensional vibrations are considered in the model using the apparent elasticity method.The accuracy of calculating resonant frequencies is more than one-dimensional design method.

3D-printed carbon black/polylactic acid electrochemical sensor combined with batch injection analysis: A cost-effective and portable tool for naproxen sensing

Additive manufacturing has emerged as an innovative technology for the large-scale development of low-cost and disposable electrochemical devices. Hence, in this paper, we highlight the use of a 3D-printed electrode using carbon black integrated polylactic acid (CB/PLA) conductive filament for electrochemical detection of naproxen (NPX), a highly consumed non-steroidal anti-inflammatory drug used in the treatment of rheumatoid arthritis, osteoarthritis, nonrheumatic inflammation, and migraine. Two designs of electrodes were fabricated using an extrusion-based 3D printer and a 3D pen (cylindrical and planar shapes) and both required only simple electrochemical surface treatment to improve their electrochemical activity towards the oxidation of NPX. The planar-shape sensor was incorporated into a 3D-printed Batch-injection analysis (BIA) cell to carry out amperometric detection (+1.3 V vs. Ag|AgCl|KCl(sat)) which provided sensing features comparable to more sophisticated sensors reported in the literature for NPX detection. Characteristics such as linear range (2 to 50 µmol L-1), limit of detection (0.9 µmol L-1), precision (RSD less than 6.7%, n = 20), high analytical frequency (105 injections h−1), and selectivity in relation to other electroactive species were achieved. Moreover, the method was applied in pharmaceutical, urine, and water samples and recovery values in the range of 88 to 105%, attesting to the accuracy and absence of matrix interference. For urine analysis, the selective detection of NPX was attained by using sequential amperometric detection to overcome the interference of electroactive species in the sample matrix. Thus, due to the great performance, the 3D-printed CB/PLA electrode proves to be an affordable and reliable platform for clinical, pharmaceutical and environmental purposes.

Determination of organophosphorus compounds in water and food samples using a non-enzymatic electrochemical sensor based on silver nanoparticles and carbon nanotubes nanocomposite coupled with batch injection analysis

This work presents, for the first time, a fast and highly sensitive electrochemical method for determination of three organophosphorus compounds (OPs), diazinon (DZN), malathion (MLT), and chlorpyrifos (CLPF), using a modified pyrolytic graphite electrode (PGE) coupled to batch injection analysis system with multiple pulse amperometric detection (BIA–MPA). The PGE was modified by a nanocomposite based on functionalized carbon nanotubes (CNTf) and silver nanoparticles (AgNPs). The OPs samples were directly analyzed on the modified working electrode surface by BIA-MPA system in Britton-Robinson (BR) buffer 0.15 mol L−1 at pH 6.0. The MPA detection of DZN, MLT and CLPF was performed using two potential pulses, which were sequentially applied on modified PGE at −1.3 V (100 ms) and +0.8 V (100 ms) for selective determination of these three OPs and working electrode cleaning, respectively. Under optimized conditions, the sensor presented a linear range of 0.1–20 μmol L−1 for DZN, 1.0–30 μmol L−1 for MLT and from 0.25 to 50 μmol L−1 for CLPF. The limits of detection (LOD) and quantification (LOQ) of 0.35 and 1.18 μmol L−1 for DZN, 0.89 and 2.98 μmol L−1 for MLT, and 0.53 and 1.78 μmol L−1 for CLPF were obtained. The proposed method exhibited high sensitivity of 0.068, 0.030 and 0.043 mA L μmol−1 for DZN, MLT and CLPF detection, respectively. Furthermore, the BIA-MPA system provided an analytical frequency of 71 determinations per hour for direct determination of these OPs in water and food samples. The modified PGE coupled to BIA-MPA system showed a high stability of electrochemical response for OPs detection with relative standard deviation (RSD) of 1.60% (n = 20). The addition-recovery studies of the proposed method were carried out in tap water, orange juice, and apple fruit real samples, which showed suitable recovery values between 77 and 124%. The analytical performance of the developed sensor provides an attractive alternative method for OPs determination with great potential for a fast and sensitive application in contaminated samples with these pesticides.

Magnetoelastic nonlinear free vibration of an annular plate under a nonuniform magnetic field of the long straight current‐carrying wire

AbstractIn this article, the magnetoelastic nonlinear free vibration of a thin conductive annular plate under the nonuniform toroidal magnetic field is investigated, where the magnetic field is generated by a long straight current‐carrying wire. Based on electromagnetic theory, expressions of the nonuniform magnetic field, electromagnetic forces are deduced. The nonlinear free vibration equation of plate is derived by using the Hamilton principle. Considering different boundary conditions, the axisymmetric vibration differential equation is achieved by the Galerkin method. The method of multiple scales is employed to obtain the second‐order approximate analytical solutions and natural frequency. In numerical calculation, the characteristics of nonlinear natural vibration and singular points varying with different parameters, for example, current intensity and plate size, are presented, respectively. The results indicate that, with the increase of current, natural frequency increases and then stabilizes in the inner‐clamped and out‐free (C‐F) boundary, but decreases and stabilizes in the cases of the inner‐clamped and out‐clamped (C‐C) boundary or inner‐simply and out‐simply (S‐S) boundary. Moreover, when wire current is off, natural frequency maintains a constant, where the equilibrium solution of the system is a center. In addition, for all boundary conditions, natural frequency increases significantly with increase of internal radius and thickness, but decreases with the increase of outer radius.

Efficiency of Geospatial Technology and Multi-Criteria Decision Analysis for Groundwater Potential Mapping in a Semi-Arid Region

The increasing water demand in Egypt causes massive stress on groundwater resources. The high variability in the groundwater depth, aquifer properties, terrain characteristics, and shortage of rainfall make it necessary to identify the groundwater potentiality in semi-arid regions. This study used the possibilities of multi-criteria decision approaches (MCDA), geographical information system (GIS), and groundwater field data to delineate potential groundwater zones in the Tushka area, west of Lake Nasser, South Egypt. Furthermore, groundwater potentiality identification can help decision-makers better plan and manage the water resources in this promising area. Eight controlling factors were utilized to achieve the objective of the present work using multi-criteria decision analysis (MCDA) approaches, namely the analytical hierarchy process (AHP) and frequency ratio (FR) models. The controlling parameters were integrated with the geographic information system (GIS) to develop the zones of groundwater potentialities. The results revealed that high and moderate-potential zones cover approximately 61% and 52% of the total area in the AHP and FR models, respectively. A total of 44 groundwater production wells along with the well yield were collected and used to validate the models. The results were evaluated using the receiver operating characteristics (ROC) curve. The best-performing prediction rates achieved by AHP and FR were 83% and 81%, respectively. Finally, the obtained results indicated that the AHP model achieved better performance than the FR model.

Comparative analysis of groundwater potentiality zone using fuzzy AHP, frequency ratio and Bayesian weights of evidence methods

Groundwater resource management in the urban area is one of the important aspects because of growing population demand and having inadequate water supply. So, proper information is needed to manage the future urban planning for such kinds of areas. This study emphasizes groundwater potentiality zone (GPZ) assessment in the Asansol urban agglomeration (AUA) region, West Bengal, India. For this purpose, we have incorporated eight conditioning factors namely LULC, lithology, slope, elevation, rainfall, drainage density, lineaments density, and soil map using conventional and remote sensing data in GIS software. All these conditioning factors have been reclassified in ArcGIS and processed by the fuzzy analytical hierarchy process (FAHP), frequency ratio (FR), and Bayesian weights of evidence (BWOE) statistical methods. Then, the groundwater potential index has been formulated, and finally, GPZ maps are generated based on of selected three models. The result shows that very high area of GPZ, e.g. 9.13%, 11.62% and 7.43% are under BWOE, FR and FAHP models, respectively. The receiver operating characteristic validation curves show that FR method (AUC = 96.4%) is well obtained for GPZ in comparison with both BWOE (AUC = 83.8%) and FAHP methods (AUC = 82.9%). Therefore, this statistical method is highly recommended for the study of groundwater potential assessment and this outcome is very suitable for the groundwater resources management in future land use planning. Precautionary works in low potential areas should be given priority for long-term planning. Thus, this study can be considered as a good document for decision support in water exploitation planning and sustainable groundwater management in AUA region.

Application of analytical hierarchal process, frequency ratio, and Shannon entropy approaches for landslide susceptibility mapping using geospatial technology: The case of Dejen district, Ethiopia

Application of analytical hierarchal process, frequency ratio, and Shannon entropy approaches for landslide susceptibility mapping using geospatial technology: The case of Dejen district, Ethiopia

Flexural–flexural internal resonances 3:1 in initially straight, extensible Timoshenko beams with an axial spring

This work investigates the dynamics of a hinged–simply supported beam with an axial spring in the neighbourhood of a 3:1 internal resonance between two successive transversal vibration modes. Multiple time scale method is applied to the analytical model of the planar extensible-shearable beam with associated boundary conditions, and a second order approximate solution is obtained. The phenomena that we investigate occur on the resonant branch of the frequency response curve around the main natural frequency, and consists of a localized extra (bent) peak on that branch. Also some detached branches have been theoretically detected in the neighbourhood of this extra peak. The analytical frequency response curves are analysed extensively and have been compared with finite element numerical simulations, finding an overall good agreement. Stability of the analytical solutions is checked by computing the eigenvalues of the Jacobian matrix and looking at the sign of their real part. Strain energies due to flexural, axial, shear deformability and axial spring are determined and compared between each other to ascertain their relative importance.

Lactoperoxidase potential in diagnosing subclinical mastitis in cows via image processing.

This report describes how image processing harnessed to multivariate analysis techniques can be used as a bio-analytical tool for mastitis screening in cows using milk samples collected from 48 animals (32 from Jersey, 7 from Gir, and 9 from Guzerat cow breeds), totalizing a dataset of 144 sequential images was collected and analyzed. In this context, this methodology was developed based on the lactoperoxidase activity to assess mastitis using recorded images of a cuvette during a simple experiment and subsequent image treatments with an R statistics platform. The color of the sample changed from white to brown upon its exposure to reagents, which is a consequence of lactoperoxidase enzymatic reaction. Data analysis was performed to extract the channels from the RGB (Red-Green-Blue) color system, where the resulting dataset was evaluated with Principal Component Analysis (PCA), Multiple Linear Regression (MLR), and Second-Order Regression (SO). Interesting results in terms of enzymatic activity correlation (R2 = 0.96 and R2 = 0.98 by MLR and SO, respectively) and of somatic cell count (R2 = 0.97 and R2 = 0.99 by MLR and SO, respectively), important mastitis indicators, were obtained using this simple method. Additionally, potential advantages can be accessed such as quality control of the dairy chain, easier bovine mastitis prognosis, lower cost, analytical frequency, and could serve as an evaluative parameter to verify the health of the mammary gland.

Portable amperometric method for selective determination of caffeine in samples with the presence of interfering electroactive chemical species

• Simple protocol to improve the selectivity of flow systems with amperometric detection. • Selective amperometric determination of compounds only oxidizable at high potentials. • Amperometric determination of caffeine in the presence of different interfering electroactive chemical substances. • Practical tool for the development of simple portable amperometric methods. In the present paper, we show that caffeine (only electrochemical oxidizable at high potentials) can be selectively determined in complex samples using a portable flow system with amperometric detection. The selective determination of caffeine was possible in several samples and in the presence of different interfering electroactive chemical species after a simple sample pretreatment step (dissolution and/or dilution in a supporting electrolyte). The results obtained were statistically similar (P > 0.05) to those acquired using an analytical separation technique (capillary electrophoresis). In addition to the improvement in selectivity, the developed method presented excellent analytical characteristics such as low limit of detection (0.26 µmol L −1 ), wide linear range (10 to 1445 µmol L −1 ; r = 0.999), high analytical frequency (130 injections h −1 ) and, adequate recovery values (108 ± 10%). The protocol proposed here shows great potential to improve the selectivity of portable amperometric methods.

Multi-Hazard Susceptibility Assessment Using the Analytical Hierarchy Process and Frequency Ratio Techniques in the Northwest Himalayas, Pakistan

Globally, natural hazards have become more destructive in recent times because of rapid urban development and exposure. Consequently, significant human life loss, the damage to property and infrastructure, and the collapse of the environment directed the attention of geoscientists to control the consequences and risk management in relation to geo-hazards. In this research, an effort was made to produce a compound map, geo-visualizing the susceptibility of multi-hazards, to select suitable sites for sustainable future development and other economic activities in the region. Muzaffarabad District was chosen as a case research area due to the high magnitude of hydro-meteorological and geological hazards. On the one hand, both selected geo-hazard inventories were developed using the field survey and remote sensing data. The subjective and objective weight of all the causative factors and their classes were calculated using the assembled geospatial techniques, such as the Analytical Hierarchy Process (AHP) and Frequency Ratio (FR) in the Geographic Information System (GIS). The results reveal that the most suitable areas are distributed in the southern and northwestern parts, which can be used for future sustainable development and other economic activities. In contrast, the eastern and western regions, including Muzaffarabad City, are within high and very susceptibility zones. Finally, more than 50% of the land area is located in very low and low susceptibility zones. The validation of the proposed model was checked by using three different techniques: the Receiver Operative Characteristic (ROC) curve, Seed Cell Area Index (SCAI), and Frequency Ratio (FR). Both ROCs, the Success Rate Curve (SRC) and the Predictive Rate Curve (PRC), showed the goodness of fit for both the selected geo-hazards: landslides (81.3%) and floods (93.2%), at 80.1% and 91.7%, respectively. All the validation techniques showed good fitness for both the individual and multi-hazard maps. The proposed model sets a baseline for policy implementation for all the stakeholders to minimize the risk and sustainable future development in areas of high frequent geo-hazards.

Integration of shannon entropy (SE), frequency ratio (FR) and analytical hierarchy process (AHP) in GIS for suitable groundwater potential zones targeting in the Yoyo river basin, Méiganga area, Adamawa Cameroon

Study regionYoyo river basin, Méiganga, Adamawa region, Cameroon. Study focusThe study aimed firstly to delineate and classify groundwater prospective zones in granito-gneissic terrain using advanced applications of remote sensing and geographical information systems through the integration of analytical hierarchy process (AHP), frequency ratio (FR) and Shannon entropy (SE). Secondly to compare the performance of these models to ensure effectiveness in computation. Thirteen groundwater influencing factors were adopted and weights were assigned to each thematic layer based on their relationship and characteristic with groundwater occurrence. Overlay weighted linear combination analysis tool in Arcgis environment was applied for groundwater prospect maps constructed. New hydrological insights for the regionGroundwater maps was classified into four categories:I poor, moderate, good and excellent. These maps analysis revealed that AHP have performed well for good and excellent classes with percentage of coved area of 23.73% and 23.75% respectively. These areas are localised in central, south-eastern, north-western and southern parts of the basin. Validation of outputs maps using wells location showed that AHP have higher accuracy (Kappa= 79.53%, AUC (predicted) = 82.40%, AUC (success) = 87.09%), compared to FR (Kappa= 74.62%, AUC (predicted) = 76.68%, AUC (success) = 77.21%) and to SE (Kappa= 77.75%, AUC (predicted) = 70.61.40%, AUC (success) = 75.78%). These results are reliable and useful for various decision-making processes and sustainable management of groundwater resources in the Yoyo river basin.

Predicting Parkinson's disease using gradient boosting decision tree models with electroencephalography signals

IntroductionParkinson's disease (PD) is a neurodegenerative disorder with only symptomatic treatments currently available. Although correct, early diagnoses of PD are important, the existing diagnostic method based on pathologic examinations only has an accuracy of approximately 80.6%. Although electroencephalography (EEG)-based assistive technology has been introduced, it has been difficult to implement in practice due to the high computational complexity and low accuracy of the analysis methods. This study proposed a fast, accurate PD prediction method using the Hjorth parameter and the gradient boosting decision tree (GBDT) algorithm. MethodWe used an open EEG dataset with 41 PD patients and 41 healthy controls (HCs); EEG signals were recorded from participants at the University of New Mexico (PD: 27 vs. HC: 27) and University of Iowa (PD: 14 vs. HC: 14). We explored the analytic time segment and frequency range in which the Hjorth parameter best represents the EEG characteristics of PD patients. ResultsOur best model (CatBoost-based) distinguished PD patients from controls with an accuracy of 89.3%, an area under the receiver operating characteristics curve (AUC) of 0.912, an F-score of 0.903, and an odds ratio of 115.5. These results showed that our models outperformed those of all other previous works and were even superior to previously known pathologic examination-based diagnoses with long-term follow-up (accuracy = 83.9%). ConclusionThe proposed methods are expected to be utilized as an effective method for improving the diagnosis of PD.

Azimuth-Invariant Motion Compensation and Imaging Chirp Scaling Algorithm for Multiple-Receiver Synthetic Aperture Sonar

To improve the imaging quality of conventional imaging algorithms without motion compensation (MOCO) and the efficiency of point-by-point MOCO algorithms for multiple-receiver synthetic aperture sonar (SAS) with azimuth-invariant six-degree of freedom (DOF) motion errors, an azimuth-invariant MOCO and imaging chirp scaling (CS) algorithm is presented in this paper. Taylor series approximation is used to process the range history in double square root form, while considering the fourth-order and inner terms with respect to the azimuth time. Using the method of series reversion and Fourier transform (FT) properties, the analytical two-dimensional frequency spectrum of the point target response of each receiver is derived. On this basis, the azimuth-invariant MOCO and imaging CS algorithm is proposed for six-DOF motion error compensation and multiple-receiver SAS imaging. Because it considers the azimuth-invariant six-DOF motion errors, the proposed algorithm has better imaging quality than conventional imaging algorithms without MOCO. Additionally, it has a significantly higher efficiency than point-by-point MOCO algorithms because the CS algorithm is a fast FT-based algorithm and does not require interpolation processing. The imaging simulation and experimental results verified the effectiveness and efficiency of the proposed algorithm.

A symplectic analytical approach for free vibration of orthotropic cylindrical shells with stepped thickness under arbitrary boundary conditions

Exact analytical solutions for free vibration of isotropic and orthotropic cylindrical shells with uniform and stepped thickness subject to general boundary conditions are presented by means of a symplectic analytical approach. The Reissner shell theory is adopted to formulate a theoretical model. By introducing a Hamiltonian system, the governing higher order partial differential equation is reduced to a set of ordinary differential equations which can be analytically solved by separating the variables. Applying the end boundary and interface continuous conditions, a set of analytical characteristic frequency equations are obtained, and exact solutions can be determined. To ensure accuracy and validity of the symplectic method, the analytical solutions for uniform and stepped cylindrical shells with isotropic or orthotropic material properties and with arbitrary boundary conditions are compared with available published data and FEM solution. A set of comprehensive new result for orthotropic stepped cylindrical shells under classical and elastic restraints are presented. Some typical mode shapes for various examples are illustrated. In addition, the effects of boundary conditions and orthotropic properties on vibration frequency are analyzed. The result shows that the fundamental frequency is higher for a boundary with more constraints.

Forest Fire Risk Zone Mapping of Eravikulam National Park in India

Forest fire is one of the most common natural hazards occurring in the Western Ghats region of Kerala and is one of the reasons for forest degradation. This natural disaster causes considerable damage to the biodiversity of this region during the dry fire season. The area selected for the present study, Eravikulam National Park, which is predominantly of grassland vegetation, is also prone to forest fires. This study aims to delineate the forest fire risk zones in Eravikulam National Park using remote sensing (RS) data and geographic information system (GIS) techniques. In the present study, methods such as Analytic Hierarchy Process (AHP) and Frequency Ratio (FR) were used to derive the weights, and the results were compared. We have used seven factors, i.e. land cover types, normalized difference vegetation index, normalized difference water index, slope angle, slope aspect, distance from the settlement, and distance from the road to prepare the fire risk zone map. The area of the prepared risk zone maps is divided into three zones, namely low, moderate, and high. From the study, it was found that the fire occurring in this area is due to natural as well as anthropogenic factors. The prepared forest fire risk zone maps are validated using the fire incidence data for the period from January 2003 to June 2019 collected from the records of the Forest Survey of India. The investigation revealed that 72% and 24% of the fire incidences occurred in the high risk zone of the maps prepared using the AHP and FR methods, respectively, which ascertained the superiority of the AHP method over the FR method for forest fire risk zone mapping. The receiver operating characteristic (ROC) curve analysis gives an area under the ROC curve (AUC) value of 0.767 and 0.567 for the AHP and FR methods, respectively. The risk zone maps will be useful for staff of the forest department, planners, and officials of the disaster management department to take effective preventive and mitigation measures.

“The Times They are A-Changin”: Introducing the Section on Contemporary Child Psychoanalytic Education

ABSTRACT Bob Dylan’s classic song, “The Times They are A-Changin,” is used to emphasize the importance for child analytic educators to address the urgency for the profession and those training future practitioners to accept the need for evolutionary change. Refusing to change our traditional ways of work and training will lead child analysis to go the way of the dinosaurs. There is already ample evidence that our field is dying as manifested in decreasing numbers of child analytic cases, child analytic candidates, and child analytic teachers and supervisors. This paper introduces a section devoted to various contemporary shifts and ideas that represent the sort of evolutionary changes required to ensure the survival and revival of child and adolescent psychoanalysis. These transformations involve expanding the role and presence of child analysis, integrating child and adult psychoanalytic curricula, redefining child analytic frequency, and incorporating parent work into child analytic theory of technique.

Simple and fast batch injection analysis method for monitoring diuron herbicide residues in juice and tap water samples using reduced graphene oxide sensor

In this paper, a new analytical method was developed using batch injection analysis with amperometric detection and reduced graphene oxide modified glassy carbon (GCE/rGO) electrode for the simple, fast, sensitive, and effective diuron (DIU) herbicide determination in tap water and food beverages (whole juice of grape and orange) samples. The GCE/rGO sensor provided a 7.6-fold increase in the DIU electrochemical oxidation current compared to the bare electrode, which resulted in a method with good sensitivity and detectability. The developed method provided important analytical characteristics for the DIU quantification, such as detection limit of 0.36 μmol L−1 (84 μg L-1) below the maximum residual limit of U.S Environmental Agency, linear range from 5 to 50 μmol L-1, good precision (RSD < 3.7 %), and accuracy (recovery levels ranging from 80.8–105.5 %). Furthermore, the minimal sample preparation (simple dilution in the supporting electrolyte) associated with a high analytical frequency (150 analyses per hour) stands out. In this sense, the proposed method proves to be an alternative analytical tool for applications in the environmental and food interest samples analysis.