Glycated hemoglobin (HbA1c) is considered as the best biomarker that can indicate glycemic level over a prolonged period of time (two to three months). Since its level corresponds to the long-term progression of diabetes without short-term variation in the glucose behavior, it has been used to diagnose diabetes. Different methods are used for HbA1c quantification including high-performance liquid chromatography, immunoassays, and electrophoresis. Despite their analytical performance, these techniques are expensive and time-consuming. In this context, we have developed a simple electrochemical aptasensor for HbA1c detection. For that, a glassy carbon electrode surface has been modified by electrochemical deposition of AuNPs. Then, L-cysteine has been chemically deposited to allow the immobilization of amino-modified HbA1c aptamer via L-cysteine carboxylic groups. Due to the affinity interaction between HbA1c and its aptamer, the incubation of this sensor in the HbA1c solution leads to the formation of an AuNPs-L-cyteine-Aptamer-HbA1c complex. Chemical surface modification was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Finally, the impedimetric detection of glycated hemoglobin was performed in presence of the redox active markers ferricyanide/ferrocyanide ions.

Naphthalimide derivatives have many interesting properties such as strong emission, high quantum efficiency, good photostability, thermal stability, etc. The electronic absorption and fluorescence spectra of naphthalimides are sensitive to the polarity of surrounding environment, and these derivatives can be excellent candidates for fluorescent sensors for water detection in solution because the emission is strongly depended on the solvent polarity and it is quenched even at low water levels. In order to find out more information about the excited state dynamics of the naphthalimide derivatives, time resolved fluorescence experiments were made in solvents of different polarities and lifetimes from 0.5 ns to 9 ns were obtained. The transient absorption map in dioxane, dimethylformamide and methanol in the presence or absence of water revealed ground state bleaching bands (GSB) in the range 230 - 290 nm, whereas an absorption band in excited state (ESA) occurs at shorter wavelengths from 210 to 295 nm. At longer wavelength negative bands appeared which can be assigned to the stimulated emissions (SE). Also, the quantum yields with absolute values from 0.01 to 0.87 were found depending on the solvent nature.

The identification and severity of structural damages in carbon fiber reinforced polymer (CFRP), especially in the early stage, is critical in structural health monitoring (SHM) of composite materials. Among several approaches used to accomplish this goal, ultrasound inspection using Lamb waves has taken place within non-destructive testing (NDT) methods. Likewise, the use of digital signal processing techniques for structural damage diagnosis has become popular due to the fact that it provides relevant information through feature extraction. In this context, this paper presents an alternative strategy based on the use of RMSD and CCDM representative indices to extract the most sensitive information related to damage in CFRP plates through ultrasonic NDT signals in specific frequency ranges. In the experimental analysis, CFRP coupons were subjected to two types of damages: cracking and delamination. The signals, generated by piezoelectric transducers attached to the host structure using the pitch-catch method of Lamb waves, were subject to signal processing parameters based on the proposed approach. The results reveal that the proposed method was able to characterize the different types of damage in CFRP, as well as their severity in specific frequency bands. The results indicate the feasibility of the proposed method to detect and characterize damage in composite materials in a simple way, which is attractive for industrial applications.

Affect recognition is a signal and pattern recognition problem that plays a major role in affective computing. The affective state of a person reflects their emotional state, which could be measured through the arousal and valence dimensions, as per the circumplex model. We attempt to predict the arousal and valence values by exploiting the Remote Collaborative and Affective Interactions (RECOLA) data set [1–3]. RECOLA is a publicly available data set of spontaneous and natural interactions that represent various human emotional and social behaviours, recorded as audio, video, electrodermal activity (EDA) and electrocardiogram (ECG) biomedical signals. In this work, we focus on the biomedical signal recordings contained in RECOLA. The signals are processed, accompanied with pre-extracted features, and accordingly labelled with their corresponding arousal or valence annotations. EDA and ECG features are fused at feature-level. Ensemble regressors are then trained and tested to predict arousal and valence values. The best performance is achieved by optimizable ensemble regression, with a testing root mean squared error (RMSE) of 0.0154 for arousal and 0.0139 for valence predictions. Our solution has achieved good prediction performance for the arousal and valence measures, using EDA and ECG features. Future work will integrate visual data into the solution.

Wireless charging technology has become increasingly popular, and demand for its inclusion in embedded systems has also risen. While there are multiple technologies available, each one has unique traits that may make a technology preferable in a given embedded system. This paper will address the prevalent technologies, including radio frequency-based wireless charging and inductive wireless charging, along with their suitability to integrate into embedded systems. This review will also provide a viable option for the most optimal wireless charging technology for small-footprint systems. After reviewing the advantages or limitations of all wireless charging technologies, it is evident that inductive coupling could be the most suitable one to implement in an embedded system when considering size, price, and efficiency. This review also presents the rationale behind this conclusion.

Wetland plays a vital role in sustainable ecological development. They hold balanced environment conditions and filter the surface and sub-surface water and moderate the local weather condition. But now-a-days wetlands are shrinking quickly due to climate change & anthropogenic activities and extinction of wetlands agitates the local environmental conditions with contexts to water and soil conditions. The current study is mainly focussed on assessment and monitoring of optically active water quality parameters viz. chlorophyll-a concentration and total suspended matters on wetland ecosystems over Harike and Keshopur wetland (designated as Ramsar site) in Punjab region, India. The sentinel-2 multispectral imager (MSI) product have been analysed in two phases: Pre-monsoon and Post-monsoon during period from 2018 to 2021 to extract spatial and temporal variations of water quality parameters. A normalised difference water index (NDWI) has been utilized to extract the water and non-water pixels and semi-analytical inversion model is used to retrieve the optically water quality parameters. A key input to semi-analytical inversion model is the pure spectral reflectance of bottom seagrass or sand to invert the corresponding for a given pixel. Accuracy of water column parameters retrievals is depends on the pure end-member of bottom which is used in the model during the inversion. For each pixel in an image, an inversion model run backward to find the best combination of input parameters value to give the closest match between the measured reflectance and the model output. The images of derived chlorophyll concentrations and total suspended matter have been found ranging from 0 to 36 mg/m³ and 0 to 156 mg/m³. This study revealed that semi-analytical model is very helpful to identify the small scale changes in optically active constituents using multispectral imagery. Water quality parameters monitoring is an important indicator to measure the productivity and eutrophication of the river water system. This research will help in understanding water cycle, water conditions and is paramount to researchers, scientists and policy makers for sustainable management. The current study also concluded that the significant reduction of highly biodiversity wetland area is required to conserve.

Microfluidic devices can provide means to handle the transport of (bio) particles within a fluid flow. The great advantage of microscale devices is that different components can be integrated in a single chip at low costs, with a negligible power consumption, compared to alternative solutions. In this work, a numerical investigation is provided on the exploitation of standing Surface Acoustic Waves (SAW) generated in a microfluidic channel to manipulate micro-particles. Far-field waves are generated via several InterDigital Transducers (IDT), travel on the surface of a piezoelectric substrate and finally interfere in the channel giving rise to a standing solution in terms of acoustic pressure. Results are reported for different geometries of the channel, to define the sensitivity of the acoustic pressure field to the relevant geometric features of the channel. This investigation shows how the acoustic radiation and drag forces interact with each other to move and focus the particles, possibly leading to a separation of heterogeneous ones, and generally provide a way to manipulate them at a small scale.

Microelectromechanical systems (MEMS) are nowadays widespread in the sensor market with a number of different applications. New production techniques and ever smaller device geometries require a continuous investigation of potential failure mechanisms in such devices. This work presents an experimental on-chip setup to assess the geometry- and material-dependent strength of stoppers adopted to limit the deformation of movable parts, using an electrostatically actuated device. A series of comb-fingers and parallel plates are used to provide a rather large stoke to a shuttle, connected to the anchors through flexible springs. Upon application of a varying voltage, failure of stoppers of variable size is observed and confirmed by postmortem ΔC-V curves. Results of an experimental campaign are collected to infer the stochastic property of the strength of polycrystalline, columnar silicon films.

This paper proposes a wireless resonant Inductive and Capacitive (LC) sensor for glucose sensing. A sensor composed of a capacitor with interdigital electrodes and an inductor for glucose sensing is presented. The resonance frequency and impedance were measured as the sensing parameters. A glucose beverage concentration from 0 to 44% is used, resulting in a resonance frequency change from 1.9217 MHz to 1.8681 MHz, and the impedance of the sensor changes from 170.33 Ω to 110.68 Ω. The resonance frequency and impedance relationship to glucose beverage concentration are well presented by a decreasing exponential function. Using an exponential regression, the resonance frequency shows an average regression error of 1.38%. Likewise, the impedance shows an average error of 3.47%. The linear range of the sensor is also analyzed at the glucose concentration range between 0 and 4%. The sensor exhibited a sensitivity of 424.6 kHz and 721.6416 Ω, respectively, with a linear regression (r2) of 0.9853 and 0.9553 respectively.

The natural environment is of the utmost significance not only for a particular location but also for the entire world. This is because the natural environment provides essential environmental services to the human population. However, the environment is being negatively impacted by human activity as well as population growth. The most significant impact was felt in the national capital region. Using the Google Earth Engine (GEE) cloud platform and the QGIS desktop, the purpose of this research is to analyse the changes in land use and land cover (LULC) transformations that have taken place in the Sonipat district of India over the past ten years (2011–2021). Change detection (CD) of a LULC map is a method that examines shifts in LULC throughout time. Landsat 7 and the Sentinel 2 satellite image collections were utilised in this study. The study area was divided into four LULC categories using the most likely classified approach to quantify the changes over the aforementioned period. The results indicated that between 2011 and 2021, cropland in the study area decreased by about 11%. Built-up and the urban area increased by 3%. With the help of this study, decision-makers will be able to make choices that are appropriate in the given situation. The findings emphasise the value of satellite monitoring in reducing the rate of environmental degradation in the Sonipat district.