Search Results (29)

Bats, as key ecological players, interact with a diverse array of organisms and perform essential roles in ecosystems, including pollination, pest control, and seed dispersal. However, their populations face significant threats from habitat contamination, particularly from microplastics (MPs). This study introduces a novel, efficient, and cost-effective method for visualizing transparent microplastics using ultraviolet (UV) light. By employing handheld UV flashlights with a wavelength range of 312 to 400 nm, we enhance the detection of MPs that may otherwise go unnoticed due to color overlap with filtration membranes. All necessary precautions were taken during sampling and analysis to minimize the risk of contamination and ensure the reliability of the results. Our findings demonstrate that the application of UV light significantly improves the visualization and identification of MPs, particularly transparent fibers. This innovative approach contributes to our understanding of plastic contamination in bat habitats and underscores the importance of monitoring environmental pollutants to protect bat populations and maintain ecosystem health. Full article

Traffic congestion has increased significantly in today’s rapidly urbanizing world, influencing people’s daily lives. Traffic signal control systems (TSCSs) play an important role in alleviating congestion by optimizing traffic light timings and improving road efficiency. Yet traditional TSCSs neglected pedestrians, cyclists, and other non-monitored road users, degrading traffic signal optimization (TSO). Therefore, this framework proposes a multi-object-based traffic flow analysis and intensity estimation model for efficient TSO using Upper Confidence Bound Multi-agent Reinforcement Learning Cubic Spline Fuzzy Logic (UCB-MRL-CSFL). Initially, the real-time traffic videos undergo frame conversion and redundant frame removal, followed by preprocessing. Then, the lanes are detected; further, the objects are detected using Temporal Context You Only Look Once (TC-YOLO). Now, the object counting in each lane is carried out using the Cumulative Vehicle Motion Kalman Filter (CVMKF), followed by queue detection using Vehicle Density Mapping (VDM). Next, the traffic flow is analyzed by Feature Variant Optical Flow (FVOF), followed by traffic intensity estimation. Now, based on the siren flashlight colors, emergency vehicles are separated. Lastly, UCB-MRL-CSFL optimizes the Traffic Signals (TSs) based on the separated emergency vehicle, pedestrian information, and traffic intensity. Therefore, the proposed framework outperforms the other conventional methodologies for TSO by considering pedestrians, cyclists, and so on, with higher computational efficiency (94.45%). Full article

This paper discusses three algorithmic strategies tailored for distinct applications, each aiming to tackle specific operational challenges. The first application unveils an innovative SMS messaging system that substitutes manual typing with voice interaction. The key algorithm facilitates real-time conversion from speech to text for message creation and from text to speech for message playback, thus turning SMS communication into an audio-focused exchange while preserving conventional messaging standards. The second application suggests a secure file management system for Android, utilizing encryption and access control algorithms to safeguard user privacy. Its mathematical framework centers on cryptographic methods for file security and authentication processes to prevent unauthorized access. The third application redefines flashlight functionality using an optimized touch interface algorithm. By employing a screen-wide double-tap gesture recognition system, this approach removes the reliance on a physical button, depending instead on advanced event detection and hardware control logic to activate the device’s flash. All applications are fundamentally based on mathematical modeling and algorithmic effectiveness, emphasizing computational approaches over implementation specifics. Full article

With the development of the chemical industry, the threat of mercury pollution to human health is increasing. Therefore, it is necessary to develop a low-cost, convenient and efficient Hg²⁺ detection method. In this study, anthracene-based Hg²⁺ fluorescent probes AN-2S and AN-4S were synthesized by a dithioacetal reaction for the rapid and efficient detection of the Hg²⁺ concentration in water. Through molecular structure design and synthesis route optimization, the complexity and cost of the probe synthesis were greatly reduced. AN-2S and AN-4S had good water solubility, rapid response abilities and anti-interference abilities, and could specifically detect Hg²⁺ using “turn-off” or “turn-on” detection modes within 1 min. The AN-4S probe showed a wide linear response range (0~40 μmol/L) and high sensitivity (4.93 × 10⁻⁸ mol/L) to Hg²⁺ in 99% aqueous solutions, over a pH range of 5~13. The reaction mechanism between the probe and Hg²⁺ was determined using 1H NMR and FT-IR spectra and Job’s curves. It was proven that the AN-2S and AN-4S probes react with Hg²⁺ in a molar ratio of 1:1 or 1:2. The dual-detection mode enabled the probes to be used not only for the accurate quantitative detection of Hg²⁺ under a fluorescence spectrometer, but also for rapid qualitative analysis using a UV flashlight as a test strip, showing a broad practical application potential. Full article

The emergence of prosumers, who actively participate in designing and producing goods, has generated a growing interest in homemade products. Factors such as design methods, component reuse, or digital fabrication empower prosumer designers to realize their ideas. Although there are cases of bioinspired products manufactured by prosumers, the interactions between bioinspired design methods in the prosumer field have not been addressed from an academic point of view. This article presents a case that combines bioinspired design methods with prosumer characteristics from the perspective of a designer who uses biological research results whilst acting as a prosumer. The proposal is to see whether working on a small scale, without the need for biomimetics experts, and independently, as a prosumer, is feasible and valuable. As a result, a bicycle flashlight is designed with a microgenerator bioinspired by the geometry of samara seeds, and is tested in a wind tunnel. This case shows that the integration of a bioinspired design in prosumer contexts poses unique challenges and requires a multidisciplinary approach. Furthermore, the application of a bioinspired approach in this case has not only provided a certain level of novelty to the final product, but has also improved its efficiency and reduced its financial expenditure. Full article

Traditional leaf chlorophyll estimation using Soil Plant Analysis Development (SPAD) devices and spectrophotometers is a high-cost mechanism in agriculture. Recently, research on chlorophyll estimation using leaf camera images and machine learning has been seen. However, these techniques use self-defined image color combinations where the system performance varies, and the potential utility has not been well explored. This paper proposes a new method that combines an improved contact imaging technique, the images’ original color parameters, and a 1-D Convolutional Neural Network (CNN) specifically for tea leaves’ chlorophyll estimation. This method utilizes a smartphone and flashlight to capture tea leaf contact images at multiple locations on the front and backside of the leaves. It extracts 12 different original color features, such as the mean of RGB, the standard deviation of RGB and HSV, kurtosis, skewness, and variance from images for 1-D CNN input. We captured 15,000 contact images of tea leaves, collected from different tea gardens across Assam, India to create a dataset. SPAD chlorophyll measurements of the leaves are included as true values. Other models based on Linear Regression (LR), Artificial Neural Networks (ANN), Support Vector Regression (SVR), and K-Nearest Neighbor (KNN) were also trained, evaluated, and tested. The 1-D CNN outperformed them with a Mean Absolute Error (MAE) of 2.96, Mean Square Error (MSE) of 15.4, Root Mean Square Error (RMSE) of 3.92, and Coefficient of Regression ($R^2$) of 0.82. These results show that the method is a digital replication of the traditional method, while also being non-destructive, affordable, less prone to performance variations, and simple to utilize for sustainable agriculture. Full article

Background: Fluorescence-aided identification technique (FIT) studies for orthodontic resins are relatively new, using an arbitrary selection of resins, lights, and work parameters. In order to provide FIT guidelines for optimal visualization, the objectives of this study were to describe the electromagnetic characteristics of fluorescent orthodontic resins, determine appropriate light specification, and describe light and work parameter effects on resin fluorescence. Methods: This in vitro study assessed five fluorescent orthodontic resins and a non-fluorescent control resin using spectrophotometry, a scaled image analysis of 25 μm thick resins to compare intensities, and a visual assessment. Light sources varied by flashlight lens (narrow [N], average [X], and magnified [Z]) and UV intensity (X and X High). Work parameters included distance (20–300 mm) and angulation (15–70°). Visual scores were assigned to determine discernibility. Results: The average excitation maxima was 384 nm. Fluorescence increased with more direct UV light exposure. The highest intensity was recorded with Light X High at 50 mm and 70°. Visual assessment followed image analysis trends, and fluorescence was clinically discernable for all 25 μm thick samples. Conclusions: Excitation wavelength range of 395–405 nm is appropriate for FIT illumination. All resins were anisotropic and showed greater fluorescence with greater angle, higher UV intensity, and closer proximity. Full article

A comprehensive entomological survey was undertaken in Alipurduar District, West Bengal, from 2018 to 2020 and in 2022. This study was prompted by reported malaria cases and conducted across nine villages, seven Sub-Centres, and three Primary Health Centres (PHCs). Mosquitoes were hand-collected with aspirators and flashlights from human dwellings and cattle sheds during the daytime. Both morphological and molecular techniques were used for species identification. Additionally, mosquitoes were tested for Plasmodium parasites and human blood presence. Mosquito species such as An. barbirostris s.l., An. hyrcanus s.l., An. splendidus, and An. vagus were morphologically identified. For species like An. annularis s.l., An. minimus s.s., An. culicifacies s.l., and An. maculatus s.s., a combination of morphological and molecular techniques was essential. The mitochondrial cytochrome c oxidase gene subunit 1 (CO1) was sequenced for An. annularis s.l., An. maculatus s.s., An. culicifacies s.l., An. vagus, and some damaged samples, revealing the presence of An. pseudowillmori and An. fluviatilis. The major Anopheles species were An. annularis s.l., An. culicifacies s.l., and An. maculatus s.s., especially in Kumargram and Turturi PHCs. Plasmodium positivity was notably high in An. annularis s.l. and An. maculatus s.s. with significant human blood meal positivity across most species. Morphological, molecular, and phylogenetic analyses are crucial, especially for archived samples, to accurately identify the mosquito fauna of a region. Notably, this study confirms the first occurrence of An. pseudowillmori and An. sawadwongporni in West Bengal and implicates An. maculatus s.s., An. culicifacies s.l., and An. annularis s.l. as significant vectors in the Alipurduar region. Full article

This paper evaluated the use of soft-probe scanning electrochemical microscopy complementarily with confocal laser scanning microscopy to study the effects of different antimicrobial agents and treatments on E. coli DH5α biofilm. The antimicrobial agents were sodium azide, silver nanoparticles, and a flashlight. The effects of these agents were monitored by measuring the change in biofilm properties, such as biofilm biomass, live/dead studies, and surface activity. The results showed that sodium azide, silver nanoparticles, and the flashlight effectively killed E. coli biofilms and explained the mode of action for each treatment. Sodium azide was more effective in killing the biofilm after a short treatment time by blocking the ATPase, while silver nanoparticles were more effective at killing the biofilm after longer treatment times through several antibiofilm actions. This work showed that scanning electrochemical microscopy (SECM) is a very valuable tool for studying the effects of antimicrobial agents on biofilms. SECM is a sensitive technique that can be used to monitor the changes in biofilm properties in real-time. Additionally, SECM does not require any sample preparation, which makes it a convenient and efficient technique. Overall, the results of this study could be used to develop new strategies for treating E. coli biofilm infections and provide valuable insights into the use of SECM to study the effects of antimicrobial agents on E. coli biofilms. Full article

The standard photometric stereo model makes several assumptions that are rarely verified in experimental datasets. In particular, the observed object should behave as a Lambertian reflector, and the light sources should be positioned at an infinite distance from it, along a known direction. Even when Lambert’s law is approximately fulfilled, an accurate assessment of the relative position between the light source and the target is often unavailable in real situations. The Hayakawa procedure is a computational method for estimating such information directly from data images. It occasionally breaks down when some of the available images excessively deviate from ideality. This is generally due to observing a non-Lambertian surface, or illuminating it from a close distance, or both. Indeed, in narrow shooting scenarios, typical, e.g., of archaeological excavation sites, it is impossible to position a flashlight at a sufficient distance from the observed surface. It is then necessary to understand if a given dataset is reliable and which images should be selected to better reconstruct the target. In this paper, we propose some algorithms to perform this task and explore their effectiveness. Full article

Three-dimensional capturing of underwater archeological sites or sunken shipwrecks can support important documentation purposes. In this study, a novel 3D scanning system based on structured illumination is introduced, which supports cultural heritage documentation and measurement tasks in underwater environments. The newly developed system consists of two monochrome measurement cameras, a projection unit that produces aperiodic sinusoidal fringe patterns, two flashlights, a color camera, an inertial measurement unit (IMU), and an electronic control box. The opportunities and limitations of the measurement principles of the 3D scanning system are discussed and compared to other 3D recording methods such as laser scanning, ultrasound, and photogrammetry, in the context of underwater applications. Some possible operational scenarios concerning cultural heritage documentation are introduced and discussed. A report on application activities in water basins and offshore environments including measurement examples and results of the accuracy measurements is given. The study shows that the new 3D scanning system can be used for both the topographic documentation of underwater sites and to generate detailed true-scale 3D models including the texture and color information of objects that must remain under water. Full article

Background: It is well-known that non-pathological axial myopic eyes present physiological and functional differences in comparison with emmetropic eyes due to altered retinal anatomy. Photostress tests have shown very significant capabilities to discriminate a normal retina from an abnormal retina. Accordingly, the aim of this work was to investigate the differences between myopic and emmetropic eyes in the measured photostress recovery time (PSRT) after retinal light-flashing in a population of young healthy subjects. Methods: A coaxial illumination total disability glare instrument was employed to measure the recovery time after photostress was induced by a 240 milliseconds flash-lighting (535 nm) exposure on 66 myopic and 66 emmetropic eyes. The measurements were carried out for different combinations of glare angles and contrasts of the visual stimuli. Results: In general terms, PSRT in myopic eyes was found at a statistically higher than in emmetropic eyes (Bonferroni correction). For both groups, the measured recovery strongly depends on the contrast of the test object used to measure baseline recovery function and markedly less on the source of glare angles explored. When the PSRTs obtained for different glare angles are averaged, the differences between PSRTs drastically increase with the reduction in the contrast of the stimuli between both groups of study. Conclusions: PSRT is higher for myopic than for young healthy emmetropic eyes (1.2 s and 0.2 s for 5% and 100% contrast test object, respectively). Though seemingly small, the magnitude of this finding can be relevant when flash-lighting happens while driving a car or while performing actions where the reaction time after a visual stimulus can be critical. Full article

Visible light communication (VLC ) is an emerging research area in wireless communication. The system works the same way as optical fiber-based communication systems. However, the VLC system uses free space as its transmission medium. The invention of the light-emitting diode (LED) significantly updated the technologies used in modern communication systems. In VLC, the LED acts as a transmitter and sends data in the form of light when the receiver is in the line of sight (LOS) condition. The VLC system sends data by blinking the light at high speed, which is challenging to identify by human eyes. The detector receives the flashlight at high speed and decodes the transmitted data. One significant advantage of the VLC system over other communication systems is that it is easy to implement using an LED and a photodiode or phototransistor. The system is economical, compact, inexpensive, small, low power, prevents radio interference, and eliminates the need for broadcast rights and buried cables. In this paper, we investigate the performance of an indoor VLC system using Optisystem simulation software. We simulated an indoor VLC system using LOS and non-line-of-sight (NLOS) propagation models. Our simulation analyzes the LOS propagation model by considering the direct path with a single LED as a transmitter. The NLOS propagation model-based VLC system analyses two scenarios by considering single and dual LEDs as its transmitter. The effect of incident and irradiance angles in an LOS propagation model and an eye diagram of LOS/NLOS models are investigated to identify the signal distortion. We also analyzed the impact of the field of view (FOV) of an NLOS propagation model using a single LED as a transmitter and estimated the bitrate $\left(R_b\right)$. Our theoretical results show that the system simulated in this paper achieved bitrates in the range of $2.1208\times {10}^7$ to $4.2147\times {10}^7$ bits/s when the FOV changes from ${30}^{\circ }$ to ${90}^{\circ }$. A VLC hardware design is further considered for real-time implementations. Our VLC hardware system achieved an average of 70% data recovery rate in the LOS propagation model and a 40% data recovery rate in the NLOS propagation model. This paper’s analysis shows that our simulated VLC results are technically beneficial in real-world VLC systems. Full article

This study aimed to evaluate the potential diagnostic value of a novel, sonographic, B-Flow (BFl)-based sign (“flashlight sign”, FLS) for the detection of wall-adherent, floating arterial structures (WAFAS). The FLS, characterized by a fast moving, very bright, intraluminal signal, was detected in 28 patients with WAFAS. We divided this cohort into three subgroups according to the affected vascular segments: (1) peripheral arteries (n = 10); (2) native abdominal aorta (n = 8); and (3) abdominal aorta after endovascular aortic repair (EVAR; n = 10). Clinical characteristics were analyzed and BFl-findings were compared with contrast-enhanced ultrasound (CEUS) and computed tomography angiography (CTA). Seven patients (25%) suffered from arterial embolism downstream to the FLS (EVAR, n = 4; native abdominal aorta, n = 1; peripheral arteries, n = 2). WAFAS of the abdominal aorta (native or after EVAR), as indicated by the FLS, were visible by CEUS and CTA in 60% and 93.3%, respectively. Based on the largest cohort (to this point) of patients with WAFAS, we propose a clinically useful, BFl-based sonographic sign for the detection of these underrated arterial pathologies in the abdominal aorta and the peripheral arteries. Full article

The aim of this study is to quantify potential systemic timing bias between fully automatic timing (FAT) and timing with iPhone camera (Apple Inc., Cupertino, CA, USA) and then consider whether an iPhone can be used as an inexpensive timing system for sprint events at athletics competitions. A flashlight was aimed at FAT camera (Lynx System Developers, Haverhill, MA, USA) and two iPhones, at 120 and 240 frames per second (fps), respectively, so that they could capture the light from it. By turning the flashlight on and off at varying intervals (1–33 s, average 9.5 s), the cameras captured a series of light beams. The time intervals between the start of two light beams were measured 31 times on the recordings from all the cameras. On each recording with the iPhones, two analyses were performed: one where the video image before the light beam (start before light) from the flashlight was set to 0 s and one where the first image with the light beam (start on light) was set to 0 s. Start on light showed no significant time differences compared to FAT. With 240 fps the standard deviation was ± 0.001 s, 29% of the times were the same as FAT, while 81% of the times are within ± 0.001 s. The largest deviation was a time of −0.003 s from FAT. With 120 fps there was a standard deviation of ± 0.003 and a maximum deviation of −0.006 s, where 39% of the times were within ± 0.001 s. At start before light, a significant but expected difference was found with an average deviation of +0.008 s with 120 fps and +0.004 s with 240 fps, with maximum deviations of +0.014 and +0.006 s. It can be concluded that the camera on an iPhone is accurate as we did not find any systematic bias from FAT with start on light. Full article