Trace element bioaccumulation, tissue distribution, and elimination in odontocetes stranded in Florida and Georgia, USA over a 15-year period (2007-2021).

Odontocetes obtain nutrients including essential elements through their diet and are exposed to heavy metal contaminants via ingestion of contaminated prey. We evaluated the prevalence, concentration, and tissue distribution of essential and non-essential trace elements, including heavy metal toxicants, in tissue (blubber, kidney, liver, skeletal muscle, skin) and fecal samples collected from 90 odontocetes, representing nine species, that stranded in Georgia and Florida, USA during 2007-2021. Samples were analyzed for concentrations of seven essential (cobalt, copper, iron, manganese, molybdenum, selenium, zinc) and five non-essential (arsenic, cadmium, lead, mercury, thallium) elemental analytes using inductively-coupled plasma mass spectrometry.

Novel adaptive loss weighted transfer network for partial domain fault diagnosis.

Mechanical fault transfer diagnosis has been confirmed as a feasible approach for tackling intelligent diagnosis with incomplete fault information and scarce labeled data on the basis of big data through the transfer of diagnostic knowledge from one or more conditions to any other condition. However, existing research has developed a hypothesis, i.e.

Ultra-sensitive and specific detection of pathogenic nucleic acids using composite-excited hyperfine plasma spectroscopy combs sensitized by Au nanoarrays functionalized with 2D TaC-MXene.

Accurate and rapid screening techniques on a population scale are crucial for preventing and managing epidemics like COVID-19. The standard gold test for nucleic acids in pathogenic infections is primarily the reverse transcription polymerase chain reaction (RT-PCR). However, this method is not suitable for widespread screening due to its reliance on large-scale equipment and time-consuming extraction and amplification processes.

Ultra-sensitive specific detection of nucleic acids in pathogenic infections by TaC-MXene sensitization-based ultrafine plasmon spectroscopy combs.

Accurate and rapid population-scale screening techniques based on SARS-CoV-2 RNA are essential in preventing and controlling the COVID-19 epidemic. However, the sensitivity and specificity of the assay signal are challenged by the problems of target dilution and sample contamination inherent in high-volume pooled testing. Here, we reported a collaborative system of high-loaded hybrid probes targeting N and OFR1a coupling with the novel TaC-M/Au/TFBG biosensor, providing high-intensity vector signals for detecting SARS-CoV-2.

Plasmonic optical fiber gratings based on few-layer TaC MXenes for refractive index sensing.

Tilted fiber Bragg grating (TFBG) is a widespread approach for developing refractive index (RI) sensors. The unique optoelectronic properties exhibited by MXene are expected to enhance the performance of TFBG-SPR sensors. In this study, a TaC coating appropriate for sensing was obtained by optimizing the photo-deposition time, which addressed the challenge of preparing large areas of MXene.

Phase Demodulation Method for Fringe Projection Measurement Based on Improved Variable-Frequency Coded Patterns.

The phase-to-height imaging model, as a three-dimensional (3D) measurement technology, has been commonly applied in fringe projection to assist surface profile measurement, where the efficient and accurate calculation of phase plays a critical role in precise imaging. To deal with multiple extra coded patterns and 2π jump error caused to the existing absolute phase demodulation methods, a novel method of phase demodulation is proposed based on dual variable-frequency (VF) coded patterns. In this paper, the frequency of coded fringe is defined as the number of coded fringes within a single sinusoidal fringe period.

An In Situ Reflectance Spectroscopic Investigation to Monitor Two-Dimensional MoS Flakes on a Sapphire Substrate.

In this work, we demonstrate the application of differential reflectance spectroscopy (DRS) to monitor the growth of molybdenum disulfide (MoS) using chemical vapor deposition (CVD). The growth process, optical properties, and structure evolution of MoS were recorded by in-situ DRS. Indeed, blue shifts of the characteristic peak B were discussed with the decrease of temperature.

Experimental Investigation of Impactor Diameter Effect on Low-Velocity Impact Response of CFRP Laminates in a Drop-Weight Impact Event.

The present study delved into the effect of impactor diameter on low velocity impact response and damage characteristics of CFRP. Moreover, the phased array ultrasonic technique (PAUT) was adopted to identify the impact damages based on double-sided scanning. Low-velocity impact tests were carried out using three hemispherical impactors with different diameters.

High Precision Detection Method for Delamination Defects in Carbon Fiber Composite Laminates Based on Ultrasonic Technique and Signal Correlation Algorithm.

This paper presents a method based on signal correlation to detect delamination defects of widely used carbon fiber reinforced plastic with high precision and a convenient process. The objective of it consists in distinguishing defect and non-defect signals and presenting the depth and size of defects by image. A necessary reference signal is generated from the non-defect area by using autocorrelation theory firstly.

Damage Localization of Composites Based on Difference Signal and Lamb Wave Tomography.

In order to deal with the problem of composite damage location, an imaging technique based on differential signal and Lamb wave tomography was proposed. Firstly, the feasibility of the technique put forward was verified by simulation. In this process, the composite model was regularly set down by the circular sensor array, with each sensor acting as an actuator in sequence to generate Lamb waves.

Improved unwrapped phase retrieval method of a fringe projection profilometry system based on fewer phase-coding patterns.

In this paper, based on two additional phase-coding patterns, an improved phase demodulation method is proposed. First, six equally spaced coding phases in the interval [$ - \pi $-π, $\pi $π] are embedded in different periods of the coded fringes following a certain sequence. Subsequently, since a group of phase orders can be uniquely determined by the four adjacent coding phases, the phase-order map of the object can be generated.

Direct Observation of Monolayer MoS Prepared by CVD Using In-Situ Differential Reflectance Spectroscopy.

The in-situ observation is of great significance to the study of the growth mechanism and controllability of two-dimensional transition metal dichalcogenides (TMDCs). Here, the differential reflectance spectroscopy (DRS) was performed to monitor the growth of molybdenum disulfide (MoS) on a SiO/Si substrate prepared by chemical vapor deposition (CVD). A home-built in-situ DRS setup was applied to monitor the growth of MoS in-situ.

Fast determination of oxides content in cement raw meal using NIR-spectroscopy and backward interval PLS with genetic algorithm.

Determining oxides content in cement raw meal with near infrared (NIR) spectroscopy, associated with partial least square (PLS) regression, is fast and potential for cement industry to realize cement raw material proportioning control. However, it has hardly been studied. Backward interval PLS (biPLS) with genetic algorithm (GA-biPLS) were applied to select characteristic variables closely related to the concentration of oxide of interest to establish calibration model.

Flexible calibration method of an FPP system based on a geometrical model and NLSM with fewer parameters: publisher's note.

This publisher's note amends the Funding section of Appl. Opt.58, A7 (2019)APOPAI0003-693510.

Flexible calibration method of an FPP system based on a geometrical model and NLSM with fewer parameters.

Fringe projection profilometry (FPP) technology is an important method for 3D reconstruction. In this paper, we proposed a flexible calibration method of an FPP system based on the imaging principle and geometrical structure of the system. The target coordinates are only related to its pixel coordinates and phase.

Development of an FBG Sensor Array for Multi-Impact Source Localization on CFRP Structures.

We proposed and studied an impact detection system based on a fiber Bragg grating (FBG) sensor array and multiple signal classification (MUSIC) algorithm to determine the location and the number of low velocity impacts on a carbon fiber-reinforced polymer (CFRP) plate. A FBG linear array, consisting of seven FBG sensors, was used for detecting the ultrasonic signals from impacts. The edge-filter method was employed for signal demodulation.

Refractive index sensor based on plastic optical fiber with tapered structure.

This work reports a refractive index sensor made of plastic optical fiber (POF) with tapered structure. Transmission loss is measured when the external environment's refractive index changes from 1.33 to 1.

[Spectral characteristics of refractive index based on nanocoated optical fiber F-P sensor].

An optical fiber Fabry-Perot (F-P) interferometer end surface was modified using layer-by-layer assembly and chemical covalent cross linking method, and the refractive index (RI) response characteristics of coated optical fiber F-P sensor were experimentally studied. Poly diallyldimethylammonium chloride (PDDA) and sodium polystyrene sulfonate (PSS) were chosen as nano-film materials. With the numbers of layers increasing, the reflection spectral contrast of optical fiber F-P sensor presents from high to low, then to high regularity.

TiO2 nanoparticle thin film-coated optical fiber Fabry-Perot sensor.

In this paper, a novel TiO(2) nanoparticle thin film coated optical fiber Fabry-Perot (F-P) sensor had been developed for refractive index (RI) sensing by monitoring the shifts of the fringe contrast in the reflectance spectra. Using in situ liquid phase deposition approach, the TiO(2) nanoparticle thin film could be formed on the fiber surface in a controlled fashion. The optical properties of as-prepared F-P sensors were investigated both theoretically and experimentally.

[Research on carbon monoxide multi-parameter detection based on ultra-narrow-linewidth laser].

Through measuring and analyzing the infrared absorption spectrum of carbon monoxide, a kind of carbon monoxide multi-parameter detection system was designed based on the characteristics of ultra-narrow-linewidth laser and the spectrum scanning technology. A ultra-narrow-linewidth tunable semiconductor laser was utilized as light source and carbon monoxide temperature detection was achieved by measuring direct absorption spectra at different temperatures. According to temperature data and the principle of differential absorption concentration detection, carbon monoxide concentration and temperature were obtained simultaneously.

[Research on gas detection based on spectrum scanning techniques of ultra-narrow-bandwidth laser].

Based on the basic principle of differential absorption detection and the spectrum scanning technology of ultra-narrow-bandwidth (UNB) laser, a kind of distributed carbon dioxide detection system with high precision was designed. An UNB laser was utilized as light source and a novel structure gas cell was also used in this system. By using the wavelength modulation technique and space division multiple access technique, the interference of other gas and dust was eliminated and the distributed detection of carbon dioxide was achieved.