Iskanje po katalogu digitalne knjižnice

Opis: This review presents recent advances in the non-enzymatic electrochemical detection and quantification of pesticides, focusing on the use of nanomaterial-based electrode modifiers and their corresponding analytical response. The use of bare glassy carbon electrodes, carbon paste electrodes, screen-printed electrodes, and other electrodes in this research area is presented. The sensors were modified with single nanomaterials, a binary composite, or triple and multiple nanocomposites applied to the electrodes’ surfaces using various application techniques. Regardless of the type of electrode used and the class of pesticides analysed, carbon-based nanomaterials, metal, and metal oxide nanoparticles are investigated mainly for electrochemical analysis because they have a high surface-to-volume ratio and, thus, a large effective area, high conductivity, and (electro)- chemical stability. This work demonstrates the progress made in recent years in the non-enzymatic electrochemical analysis of pesticides. The need for simultaneous detection of multiple pesticides with high sensitivity, low limit of detection, high precision, and high accuracy remains a challenge in analytical chemistry.
Ključne besede: electroanalysis, non-enzymatic sensors, nanomaterials, pesticides
Objavljeno v DKUM: 15.05.2025; Ogledov: 0; Prenosov: 7
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Opis: To equip computers with human communication skills and to enable natural interaction between the computer and a human, intelligent solutions are required based on artificial intelligence (AI) methods, algorithms, and sensor technology. This study aimed at identifying and analyzing the state-of-the-art AI methods and algorithms and sensors technology in existing human–computer intelligent interaction (HCII) research to explore trends in HCII research, categorize existing evidence, and identify potential directions for future research. We conduct a systematic mapping study of the HCII body of research. Four hundred fifty-four studies published in various journals and conferences between 2010 and 2021 were identified and analyzed. Studies in the HCII and IUI fields have primarily been focused on intelligent recognition of emotion, gestures, and facial expressions using sensors technology, such as the camera, EEG, Kinect, wearable sensors, eye tracker, gyroscope, and others. Researchers most often apply deep-learning and instance-based AI methods and algorithms. The support sector machine (SVM) is the most widely used algorithm for various kinds of recognition, primarily an emotion, facial expression, and gesture. The convolutional neural network (CNN) is the often-used deep-learning algorithm for emotion recognition, facial recognition, and gesture recognition solutions.
Ključne besede: human–computer intelligent interaction, intelligent user interfaces, IUI, sensors, artificial intelligence
Objavljeno v DKUM: 31.03.2025; Ogledov: 0; Prenosov: 8
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Opis: Benezediols are widely used in different areas of industry, thus identification and quantification of benzenediols is of utmost importance due to their toxicity and high environmental abundance. In this work, benzenediol isomers (pyrocatechol, resorcinol, and hydroquinone) were investigated by using the Bray–Liebhafsky (BL) oscillatory reaction. All three isomers exhibit different behavior in the BL reaction, which renders the BL system applicable as a chemosensor. The period between the fifth and sixth oscillation, the amplitude of the sixth oscillation and in the case of hydroquinone, the emergence of a new oscillation in the BL reaction were selected as the parameters used for the identification and quantification of these isomers. Furthermore, electron paramagnetic resonance spectroscopy and DFT calculations were performed in order to provide insights into the mechanism of benzenediols reactions with the BL system.
Ključne besede: oscillatory reactions, Bray–Liebhafsky reaction, benzenediols, chemical sensors, radical scavenging
Objavljeno v DKUM: 31.01.2025; Ogledov: 0; Prenosov: 8
Celotno besedilo (4,69 MB)
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Opis: Two new surfactant sensors were developed by synthesizing Pt-doped acid-activated multiwalled carbon nanotubes (Pt@MWCNTs). Two different ionophores using Pt@MWCNTs, a new plasticizer, and (a) cationic surfactant 1,3-dihexadecyl-1H-benzo[d]imidazol-3-ium-DHBI (Pt@MWCNT-DHBI ionophore) and (b) anionic surfactant dodecylbenzenesulfonate-DBS (Pt@MWCNT-DBS ionophore) composites were successfully synthesized and characterized. Both surfactant sensors showed a response to anionic surfactants (dodecylsulfate (SDS) and DBS) and cationic surfactants (cetylpyridinium chloride (CPC) and hexadecyltrimethylammonium bromide (CTAB)). The Pt@MWCNT-DBS sensor showed lower sensitivity than expected with the sub-Nernstian response of ≈23 mV/decade of activity for CPC and CTAB and ≈33 mV/decade of activity for SDS and DBS. The Pt@MWCNTDHBI surfactant sensor had superior response properties, including a Nernstian response to SDS (59.1 mV/decade) and a near-Nernstian response to DBS (57.5 mV/decade), with linear response regions for both anionic surfactants down to ≈2 × 10−6 M. The Pt@MWCNT-DHBI was also useful in critical micellar concentration (CMC) detection. Common anions showed very low interferences with the sensor. The sensor was successfully employed for the potentiometric titration of a technical grade cationic surfactant with good recoveries. The content of cationic surfactants was measured in six samples of complex commercial detergents. The Pt@MWCNT-DHBI surfactant sensor showed good agreement with the ISE surfactant sensor and classical two-phase titration and could be used as an analytical tool in quality control
Ključne besede: potentiometric surfactant sensor, metal-doped MWCNT, surfactants, carbon nanocomposite, sensors
Objavljeno v DKUM: 23.08.2024; Ogledov: 110; Prenosov: 12
Celotno besedilo (16,29 MB)

Opis: We proposed a method for measuring frequency differences of the order of a few Hz with an experimental error lower than 0.0001% by using two 4 MHz quartz oscillators, the frequencies of which are very close (a few 10 Hz difference) due to the dual mode operation (differential mode with two temperature-compensated signal frequencies or a mode with one signal and one reference frequency). We compared the existing methods for measuring frequency differences with the new method which is based on counting the number of transitions through zero within one beat period of the signal. The measuring procedure requires equal experimental conditions (temperature, pressure, humidity, parasitic impedances etc.) for both quartz oscillators. To ensure equal resonant conditions for oscillation two quartz crystals are needed, which form a temperature pair. The frequencies and resonant conditions of both oscillators must be almost equal, which is achieved by an external inductance or capacitance. In such a way, we minimized all the external effects and ensured highly stable oscillations and high sensitivity of the differential sensors. The counter detects one beat period by an external gate signal former. By using the method of counting transitions through zero within one beat period, we reduced the measuring error by three orders of magnitude, compared to the existing methods.
Ključne besede: small frequency difference measurement, temperature-compensated quartz sensors, differential sensors, quartz oscillators, transitions-through-zero method
Objavljeno v DKUM: 26.03.2024; Ogledov: 357; Prenosov: 246
Celotno besedilo (4,21 MB)
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