Video Imaging Techniques Research Articles

A New Interpretation of the Dominance and Diversity of Horseshoe Island (Antarctic Peninsula) Epibenthic Communities

This study investigates the epibenthic communities of Lystad Bay on Horseshoe Island (Western Antarctica) using underwater video imaging techniques during the eighth Turkish Antarctic Expedition in 2024. The primary objective of the study was to assess species diversity across different depths, substrate structures and potential ice scouring. Six sampling stations were selected, varying in depth (3–34 m) and substrate type (rocky, sandy, and muddy). Results show that a general tendency for an increase in species diversity with depth, particularly below 19 m, and is higher on sandy-muddy substrates than on rocky ones. The analysis of video footage identified 30 species from six phyla, with the highest species richness recorded at deeper stations (St 6) and the lowest at shallower rocky areas (St 1). The analysis of diversity indices (Shannon-Weiner, Margalef, and Pielou's evenness) inticates that substrate type exerts a significant influence on species richness, with sandy-mud habitats exhibiting higher diversity. Station 4 exhibited a low species richness, possibly as a result of local ice scouring impacts despite its depth and the presence of suitable benthic habitat. This study highlights the importance of oceanographic and environmental factors, such as ice scouring and terrestrial inputs, are in determining the organization of Antarctic benthic communities. Further research is required to understand the long-term effects of comprehend these elements on the biodiversity of the Antarctic ecosystem. This study is the inaugural comprehensive study in this region and will serve as a pivotal reference point for future research endeavours.

The gut-brain and gut-macrophage contribution to gastrointestinal dysfunction with systemic inflammation

The gastrointestinal tract is one of the main organs affected during systemic inflammation and disrupted gastrointestinal motility is a major clinical manifestation. Many studies have investigated the involvement of neuroimmune interactions in regulating colonic motility during localized colonic inflammation, i.e., colitis. However, little is known about how the enteric nervous system and intestinal macrophages contribute to dysregulated motility during systemic inflammation. Given that systemic inflammation commonly results from the innate immune response against bacterial infection, we mimicked bacterial infection by administering lipopolysaccharide (LPS) to rats and assessed colonic motility using ex vivo video imaging techniques. We utilized the Cx3cr1-Dtr rat model of transient depletion of macrophages to investigate the role of intestinal macrophages in regulating colonic motility during LPS infection. To investigate the role of inhibitory enteric neurotransmission on colonic motility following LPS, we applied the nitric oxide synthase inhibitor, Nω-nitro-L-arginine (NOLA). Our results confirmed an increase in colonic contraction frequency during LPS-induced systemic inflammation. However, neither the depletion of intestinal macrophages, nor the suppression of inhibitory enteric nervous system activity impacted colonic motility disruption during inflammation. This implies that the interplay between the enteric nervous system and intestinal macrophages is nuanced, and complex, and further investigation is needed to clarify their joint roles in colonic motility.

Settling velocity of atmospheric particles in seawater: Based on hydrostatic sedimentation method using video imaging techniques

When atmospheric particles deposit to the ocean, their settling velocities and residence times associated are critical for their effects on oceanic ecosystems. We developed a hydrostatic sedimentation method using video imaging techniques to track particles of 5–20 μm in diameter falling into seawater and determine the particle settling velocities in relation to their diameter, shape, organic matter contained, and seawater salinity. The measured settling velocities varied from 0.025 to 0.41 mm/s. Irregular particle shape and organic matter contained in particles also, however, reduced the values. The settling velocities were decelerated by the dissolution process of particle in seawater. Combined with the experimental results, a formula for calculating the settling velocity formulae for atmospheric particles was estimated. Using this equation, the residence time of particles is estimated to be less than one month in continental shelf sea and more than 100 days in the oceans.

Megalencephalic leukoencephalopathy with subcortical cysts protein-1: A new calcium-sensitive protein functionally activated by endoplasmic reticulum calcium release and calmodulin binding in astrocytes

BackgroundMLC1 is a membrane protein highly expressed in brain perivascular astrocytes and whose mutations account for the rare leukodystrophy (LD) megalencephalic leukoencephalopathy with subcortical cysts disease (MLC). MLC is characterized by macrocephaly, brain edema and cysts, myelin vacuolation and astrocyte swelling which cause cognitive and motor dysfunctions and epilepsy. In cultured astrocytes, lack of functional MLC1 disturbs cell volume regulation by affecting anion channel (VRAC) currents and the consequent regulatory volume decrease (RVD) occurring in response to osmotic changes. Moreover, MLC1 represses intracellular signaling molecules (EGFR, ERK1/2, NF-kB) inducing astrocyte activation and swelling following brain insults. Nevertheless, to date, MLC1 proper function and MLC molecular pathogenesis are still elusive. We recently reported that in astrocytes MLC1 phosphorylation by the Ca2+/Calmodulin-dependent kinase II (CaMKII) in response to intracellular Ca2+ release potentiates MLC1 activation of VRAC. These results highlighted the importance of Ca2+ signaling in the regulation of MLC1 functions, prompting us to further investigate the relationships between intracellular Ca2+ and MLC1 properties. MethodsWe used U251 astrocytoma cells stably expressing wild-type (WT) or mutated MLC1, primary mouse astrocytes and mouse brain tissue, and applied biochemistry, molecular biology, video imaging and electrophysiology techniques. ResultsWe revealed that WT but not mutant MLC1 oligomerization and trafficking to the astrocyte plasma membrane is favored by Ca2+ release from endoplasmic reticulum (ER) but not by capacitive Ca2+ entry in response to ER depletion. We also clarified the molecular events underlining MLC1 response to cytoplasmic Ca2+ increase, demonstrating that, following Ca2+ release, MLC1 binds the Ca2+ effector protein calmodulin (CaM) at the carboxyl terminal where a CaM binding sequence was identified. Using a CaM inhibitor and generating U251 cells expressing MLC1 with CaM binding site mutations, we found that CaM regulates MLC1 assembly, trafficking and function, being RVD and MLC-linked signaling molecules abnormally regulated in these latter cells. ConclusionOverall, we qualified MLC1 as a Ca2+ sensitive protein involved in the control of volume changes in response to ER Ca2+ release and astrocyte activation. These findings provide new insights for the comprehension of the molecular mechanisms responsible for the myelin degeneration occurring in MLC and other LD where astrocytes have a primary role in the pathological process.

DETERMINATION OF WAVE RUN-UP THROUGH THE TIMESTACK METHODOLOGY AND THROUGH A RESISTIVE WAVE GAUGE. A COMPARATIVE ANALYSIS

The objective of this work is the comparison of two methodologies used for run-up measurements in a two-dimensional physical model, which represented the protection breakwaters of the Peniche and Ericeira’s ports. Tests were carried out in the scope of the BSafe4sea project. The methodologies used were: a) the traditional measurement of the run-up height with a resistive wave gauge; b) the use of video cameras and image processing techniques images to infer the run-up heights, having its performance evaluated for some of the test conditions. Regarding the results obtained, in terms of Ru2% and Rumax, it was found that the magnitude of the values obtained with the two techniques were quite similar, although the video analysis returned slightly higher values than the wave gauge. Thus, it was found that the video image technique is a viable alternative to measure the run-up. It is recommended the use of diffused light during the tests, along with stabilizing the video camera, to improve the accuracy of the results obtained by the video-based technique. Besides, the quality of the video image and the use different colors of the armour units of the phicial model, could contribute to achieve better results with the TimeStack methodology.

Velocity measurement of pneumatically conveyed particles via a simple current signal technique and the influence of electrostatic charge

Particle velocity in pulse feeding pneumatic conveying was measured utilizing current signal analysis and video imaging. Glass beads and silica particles were conveyed in a conductive tube (ID of 4.57 × 10 −3 m) at gas velocities of 7, 15, and 30 m/s. To measure particle velocity, electrical current signal method was used with a new approach that uses raw current data and eliminates signal conditioning and cross-correlation analysis. This technique was successful and results were comparable to video imaging results. The conveyed particles' charge was measured to determine its influence on particle velocity. 30 m/s gas velocity resulted in a turbulent flow and greater charge generation causing more deviations between particle and gas velocity due to the enhancement of particles' radial motion. Finally, the comparison of results with predictions of existing models revealed that further research is necessary to better understand the effect of particles' motion and charge on their conveying velocity. Video imaging and current signal measurement techniques and the acquired electrostatic charge during pneumatic conveying. • Particle velocity in pneumatic conveying was measured based on particles charge. • A simplified technique based on electrical current signal method was proposed. • Influence of particles electrostatic charge on their velocity was investigated. • Existing models overestimated particle velocity in the presence of electrostatics. • Existing models predictions were not in agreement to the measurements at high gas velocities.

Examining enteric nervous system function in rat and mouse: an interspecies comparison of colonic motility.

Gastrointestinal motility is crucial to gut health and has been associated with different disorders such as inflammatory bowel diseases and postoperative ileus. Despite rat and mouse being the two animal models most widely used in gastrointestinal research, minimal studies in rats have investigated gastrointestinal motility. Therefore, our study provides a comparison of colonic motility in the mouse and rat to clarify species differences and assess the relative effectiveness of each animal model for colonic motility research. We describe the protocol modifications and optimization undertaken to enable video imaging of colonic motility in the rat. Apart from the broad difference in terms of gastrointestinal diameter and length, we identified differences in the fundamental histology of the proximal colon such that the rat had larger villus height-to-width and villus height-to-crypt depth ratios compared with mouse. Since gut motility is tightly regulated by the enteric nervous system (ENS), we investigated how colonic contractile activity within each rodent species responds to modulation of the ENS inhibitory neuronal network. Here we used Nω-nitro-l-arginine (l-NNA), an inhibitor of nitric oxide synthase (NOS) to assess proximal colon responses to the stimulatory effect of blocking the major inhibitory neurotransmitter, nitric oxide (NO). In rats, the frequency of proximal colonic contractions increased in the presence of l-NNA (vs. control levels) to a greater extent than in mice. This is despite a similar number of NOS-expressing neurons in the myenteric plexus across species. Given this increase in colonic contraction frequency, the rat represents another relevant animal model for investigating how gastrointestinal motility is regulated by the inhibitory neuronal network of the ENS.NEW & NOTEWORTHY Mice and rats are widely used in gastrointestinal research but have fundamental differences that make them important as different models for different questions. We found that mice have a higher villi length-to-width and villi length-to-crypt depth ratio than rat in proximal colon. Using the ex vivo video imaging technique, we observed that rat colon has more prominent response to blockade of major inhibitory neurotransmitter (nitric oxide) in myenteric plexus than mouse colon.

A simultaneous measurement technique for soot temperature and volume fraction of sooting flames considering self-absorption through hyperspectral imaging

Due to the complex optical properties of sooting flames, the accuracy of flame emission-based measurement techniques depends on an appropriate self-absorption correction strategy. Thus, this paper presents a novel iterative procedure to retrieve the soot temperature and volume fraction of sooting flames along with a self-absorption correction strategy through hyperspectral imaging. Numerical simulations were carried out on suppositional flames to investigate the performance of the proposed technique. Relative errors obtained from the simulations are below 1.5%, indicating a better accuracy can be achieved by the proposed reconstruction technique. A hybrid camera hyperspectral video imaging technique is designed and implemented with the concept of compressed sensing. A significant improvement in flame spectrum acquisition has been observed. Experiments were carried out under ethylene-air diffusion flames to validate the technique. The reconstructed flame soot temperature and volume fraction distributions demonstrated that the proposed hyperspectral video imaging technique improves the soot temperature and volume fraction reconstruction accuracy.

Experimental investigation of two-phase flow regimes in rectangular micro-channel with two mixer types

This study primarily aimed to explore the two-phase flow characteristics in a rectangular channel with a hydraulic diameter of 1.33 mm. High-speed video imaging techniques were used to capture two-phase flow behavior corresponding to different superficial gas and liquid velocities. To examine the effect of the gas–liquid mixer configuration on two-phase flow patterns, experiments were conducted using two types of mixers. The results show that the mixer configuration can affect the flow structure only in the slug flow regime. The present study provides a more detailed classification of flow regimes than previous studies. The flow regimes observed were classified into seven categories: slug, aerated-slug, transition, multiple, wavy-annular, smooth-annular, and dispersed-annular flows. Moreover, the quantitative characterization of flow regimes and transition boundaries in micro-channel flows using the standard deviation of differential pressure fluctuations was attempted. This study comprehensively reviews and assesses previous two-phase flow regime maps for both macro-channels and mini/micro-channels. It is shown that the two-phase flow pattern in mini/micro-channels is influenced by various factors, such as the channel hydraulic diameter, the channel cross-sectional shape, the gas–liquid mixer configuration, the difference in the hydraulic diameters between the mixer outlet and test channel, and the thermophysical properties of the working fluids. The comparison between the present experimental data and predictions of the previous flow regime maps demonstrates the necessity of developing a new flow regime map to accurately predict two-phase flow regimes in micro-channels.

Predicting vasovagal reactions to a virtual blood donation using facial image analysis.

BackgroundPeople with needle fear experience not only anxiety and stress but also vasovagal reactions (VVR), including nausea, dizziness, sweating, pallor changes, or even fainting. However, the mechanism behind needle fear and the VVR response are not yet well understood. The aim of our study was to explore whether fluctuations in facial temperature in several facial regions are related to the level of experienced vasovagal reactions, in a simulated blood donation.Study design and methodsWe recruited 45 students at Tilburg University and filmed them throughout a virtual blood donation procedure using an Infrared Thermal Imaging (ITI) camera. Participants reported their fear of needles and level of experienced vasovagal reactions. ITI data pre‐processing was completed on each video frame by detecting facial landmarks and image alignment before extracting the mean temperature from the six regions of interest.ResultsTemperatures of the chin and left and right cheek areas increased during the virtual blood donation. Mixed‐effects linear regression showed a significant association between self‐reported vasovagal reactions and temperature fluctuations in the area below the nose.DiscussionOur results suggest that the area below the nose may be an interesting target for measuring vasovagal reactions using video imaging techniques. This is the first in a line of studies, which assess whether it is possible to automatically detect levels of fear and vasovagal reactions using facial imaging, from which the development of e‐health solutions and interventions can benefit.

Ebselen prevents cigarette smoke-induced gastrointestinal dysfunction in mice.

Gastrointestinal (GI) dysfunction is a common comorbidity of chronic obstructive pulmonary disease (COPD) for which a major cause is cigarette smoking (CS). The underlying mechanisms and precise effects of CS on gut contractility, however, are not fully characterised. Therefore, the aim of the present study was to investigate whether CS impacts GI function and structure in a mouse model of CS-induced COPD. We also aimed to investigate GI function in the presence of ebselen, an antioxidant that has shown beneficial effects on lung inflammation resulting from CS exposure. Mice were exposed to CS for 2 or 6 months. GI structure was analysed by histology and immunofluorescence. After 2 months of CS exposure, ex vivo gut motility was analysed using video-imaging techniques to examine changes in colonic migrating motor complexes (CMMCs). CS decreased colon length in mice. Mice exposed to CS for 2 months had a higher frequency of CMMCs and a reduced resting colonic diameter but no change in enteric neuron numbers. Ten days cessation after 2 months CS reversed CMMC frequency changes but not the reduced colonic diameter phenotype. Ebselen treatment reversed the CS-induced reduction in colonic diameter. After 6 months CS, the number of myenteric nitric-oxide producing neurons was significantly reduced. This is the first evidence of colonic dysmotility in a mouse model of CS-induced COPD. Dysmotility after 2 months CS is not due to altered neuron numbers; however, prolonged CS-exposure significantly reduced enteric neuron numbers in mice. Further research is needed to assess potential therapeutic applications of ebselen in GI dysfunction in COPD.

Eksperymentalne badania pilotów dronów telewizyjnych: metody gromadzenia, wizualizacji i analizy danych dotyczących ruchu oka i głowy pilota w czasie lotu z widocznością drona

Obraz rejestrowany przez drony telewizyjne, włączany do materiałów reporterskich i relacji live, rozszerza możliwości informacyjne współczesnych telewizji. Ponieważ technologia ta wykorzystywana jest w przemyśle telewizyjnym od niedawna, badania dotyczące pilotów telewizyjnych dronów są jeszcze stosunkowo skromne. Kwerenda literatury wskazuje, że naukowcy stale poszukują najbardziej efektywnych metod badań pracy pilotów dronów telewizyjnych, m.in. w celu poprawy parametrów używanych przez tych pilotów kontrolerów lotu dronów. Cel: stworzenie i przetestowanie eksperymentalnej metody badawczej wykorzystującej techniki realizacji obrazu wideo, która, w zestawieniu z innymi metodami stosowanymi w badaniach medioznawczych (eyetracking i badania deklaratywne), pozwoli na uzyskanie komplementarnych danych dotyczących ruchów głowy i oka pilota drona umożliwiających obserwację drona i ekranu kontrolera drona. Metody badań: pomiary biometryczne: eyetracking, eksperymentalna metoda technik realizacji i analizy obrazu wideo, metoda sędziów kompetentnych, badanie ankietowe. Wyniki i wnioski: potwierdzono przydatność przyjętych metod w prowadzeniu badań dotyczących obserwacji drona i jego kontrolera w czasie lotu z widocznością drona. Wartość poznawcza: zastosowanie przyjętej metody eksperymentalnej pozwoliło na wyodrębnienie współczynnika lotu VLOS (lot z widocznością drona), którego wartość może wskazywać na poziom bezpieczeństwa i efektywności filmowania dronem. W wymiarze praktycznym współczynnik ten może być przydatny m.in. przy projektowaniu szkoleń dla pilotów dronów telewizyjnych oraz w ocenie ryzyka lotu w danej przestrzeni powietrznej.

Spreading of Normal Liquid Helium Drops.

We have used video imaging and interferometric techniques to investigate the dynamics of spreading of drops of ^{4}He on a solid surface for temperatures ranging from 5.2K (near the critical point) to 2.2K (near T_{λ}). After an initial transient, the drops become pancake-shaped with a radius that grows as R(t)≈t^{α}, with α=0.149±0.002. The drops eventually begin to shrink due to evaporation driven by gravitational and curvature effects, which limits their lifetime to about 1000s. Although helium completely wets the substrate, and the spreading takes place over a pre-existing adsorbed film, a distinct contact line with a contact angle of order one degree is visible throughout this process.

Propagation, deposition, and suspension characteristics of constant-volume particle-driven gravity currents

In this laboratory study, propagation behaviour, particle deposition patterns, and suspension characteristics of non-cohesive particle-driven gravity currents formed under constant-volume release conditions were investigated. The experimental gravity currents were created in a two-dimensional lock exchange type tank using two different particles (silicon carbide and glass beads) with four different median diameters. Video imaging and image processing techniques were utilized to monitor the current propagation, laser diffraction size analysis and dry weighing techniques were utilized to examine the size and mass characteristics of the deposits and suspensions, and acoustic Doppler velocimetry was utilized for flow velocity measurements for turbulence analysis. Our observations showed that the experimental gravity currents experienced two different propagation phases based upon the particle settling regimes. The first propagation phase was named as the propagation with the turbulence-dominated settling (TDS) and the later propagation phase was named as the propagation with gravity-dominated settling (GDS). It is found that a critical turbulent Reynolds number value (estimated to be O(1)) delineates the settling regimes, hence determines the transition between the propagation phases. With increasing particle settling velocity, the observed propagation phases in our experimental currents showed increasing deviations from the slumping, inertia-buoyancy, and viscous–buoyancy propagation phases that have been reported for homogeneous constant-volume gravity currents with no or negligible settling in the literature. Propagation observations showed that the initial median particle diameters of the currents have negligible effect on the current propagation characteristics during the TDS phase, but become important during the GDS phase. The currents with smaller initial median particle diameters propagated faster and a longer distance in the GDS phase than their counterparts with larger median particle diameters. The deposited particle characteristics indicated that particles of different sizes settle at similar speeds during the TDS phase due to turbulent mixing and the settling speed becomes dependent on the particle size during the GDS phase. As a result, size sorting of the deposited particles became more pronounced during the GDS phase. At the earlier stages of propagation, the vertical profiles of suspended particle concentrations in the current head showed some extent of vertical uniformity due to turbulent mixing around the half height of the current head. On the other hand, at the later stages of propagation, suspended particle concentration profiles exhibited an exponential profile. Deposited and suspended particle characteristics showed that horizontal particle sorting, that is size grading of particles in the flow direction, was more pronounced than the vertical particle sorting, that is size grading of particles at different elevations within the current head.

Does the Change in the Indications of Endoscopic Sinonasal Surgery Continue? Data between 1994-2018.

Endoscopic sinonasal surgery (ESS) has changing over the years in parallel with the developments in endoscopy devices, video-imaging techniques, and surgical instruments. In the present study we investigated whether the indications of patients who underwent surgery over a period of 25 years have accommodated to these changes. We retrospectively evaluated 1173 patients who underwent surgery in our clinic from 1994 through 2007, and 954 patients who underwent surgery from 2008 through 2018. The patients were divided into three groups as follows: chronic rhinosinusitis with polyps (CRSwNP), chronic rhinosinusitis without polyps (CRSsNP), and others. The changes in the indications during the first 14 years and the following 11 years were compared, and the results were statistically evaluated. A significant decrease was observed in the number of patients who underwent surgery following the diagnosis of CRSsNP (p<0.001). In addition, a statistically significant increase was found in CRSwNP (p<0.001) and other (p<0.001) indications. When ESS indications identified in our clinic were reviewed, it was observed that the increasing trend in CRSwNP rate in the first 14 years continued, there was a significant increase in non-CRS indications in the last 11 years, and there has been an increase in patients with fungal sinusitis, especially in this group.

Development and Application of Tunnel Apparent Distress Monitoring System Based on Video Image Analysis

With a lack of complete system and hardware equipment for long-term monitoring of distresses in an operating tunnel to address theoretical and technical issues, it is necessary to develop an IoT-based integrated system for long-term monitoring of lining crack, water leakage and spalling in an operating tunnel using video image processing technology and technique in conjunction with computer programming languages. Use of video image processing methods of this monitoring system allows rapid, accurate identification of distresses and the extent thereof. It is concluded that linear array CCD is the best option for engineering surveillance cameras since such CCD is able to accurately capture both static and dynamic targets; the use of higher-definition cameras provides for tiny target identification under remote monitoring conditions and the addition of temporary storage module for field data.

Nonverbal Synchrony of Facial Movements and Expressions Predict Therapeutic Alliance During a Structured Psychotherapeutic Interview

Nonverbal synchrony (NVS) of a patient’s and therapist’s body parts during a therapy session has been linked with therapeutic alliance. However, the link between NVS of face parts with therapeutic alliance remains unclear. The clarification of this link is important in understanding NVS. Accordingly, we used a video imaging technique to provide quantitative evidence of this link. The 55 participants in this study were the same as in a previous study. Both the participants’ and the therapist’s faces were video recorded during structured psychotherapeutic interviews. Our machine quantified 500,500 participants’ faces and 500,500 therapists’ faces from the perspectives of facial movements and expressions. Results show that absolute synchrony of happy and scared expressions were positively related to therapeutic alliance. However, symmetrical synchrony of left eye movements negatively predicted therapeutic alliance, although participants’ sex, age, volume of facial movements, and volume of facial expressions were controlled. Absolute synchrony of facial expressions was regarded as emotional interaction within 2 s delay, whereas symmetrical synchrony of left eye movements was regarded as a blocker of emotional interaction.

A Comprehensive Research on Video Imaging Techniques

In today’s world, Video imaging techniques are extremely important due to its manifold advantages as they contribute extensively to connectivity of people from one part of the world to another. In this constrain the authors focused to emphasize the numerous technologies available for video image process, highlights of the significant research works carried out in Video imaging techniques has been represented as a review article. Further the article will give the more information about latest techniques; it also summarizes the features of all works with respect to video imaging processing techniques. Hence, the objective of this work is to benefit scientists and new entrants in the field of Video imaging to get overview of the technologies.

L-Carnitine activates calcium signaling in human osteoblasts

L-Carnitine (L-C) is a conditionally essential nutrient required for β-oxidation and cell energy production whose unbalanced metabolism is associated with a variety of diseases. L-C increased cell proliferation, differentiation and mineralization of human osteoblast in culture. The present study evaluated the effect of L-C on intracellular calcium signaling, an important modulator of cell proliferation and differentiation in human osteoblasts by means of Fura-2 fluorescence coupled to video imaging technique. 5 mM L-C promoted a calcium influx from the extracellular milieu by depolarizing L-type calcium channels. Moreover, L-C depleted the calcium stores of the mitochondria and of the endoplasmic reticulum through phospholipase C activation. The inhibition of the calcium sensing receptor with 10 µM NPS-2143 prevented the L-C dependent cytosolic calcium increase suggesting that this calcium mobilization is mediated by Calcium Sensing Receptor activation. These results unravel that L-C might be part of a complex nutritional environment which tunes osteoblast activity.

Validating the early corrosion sensing functionality in poly (ether imide) coatings for enhanced protection of magnesium alloy AZ31

This work reports on the validation studies of early corrosion sensing poly ether imide (PEI) coatings with incorporated pH-sensing phenolphthalein loaded silica nano-sized capsules (SiNCs-PhPh) on AZ31 magnesium alloys. Immersion and drop tests validated the high sensing accuracy and PhPh color-signaling reproducibility of the coatings upon onset of corrosion. This behavior is correlated to the homogeneous dispersion of SiNC particle agglomerates confirmed by 3D Raman mapping and SEM analysis. Complementary differential video imaging technique (DVIT) assisted by electrochemical impedance spectroscopy (EIS) investigations provided clues for a good correlation between the kinetics of color signaling and the corrosion activity. Mechanistic insights into the pH-sensing/color-signaling functionality in PEI coatings are suggested.