Pipeline Elbow Corrosion Simulation for Strain Monitoring with Fiber Bragg Gratings.

This study addresses the limitation of traditional non-destructive testing methods in real-time corrosion monitoring of pipe elbows by proposing the utilization of fiber Bragg grating (FBG) strain sensors, renowned for their resilience in harsh environments. However, the current mathematical relationship model for strain representation of elbow corrosion is still lacking. This paper develops a finite element model to scrutinize the strain changes in the elbow due to corrosion under hydrostatic pressure and bending loads. To mitigate temperature loading effects, the corrosion degree is evaluated through the disparity between hoop and axial strains. Simulation outcomes reveal that, under hydrostatic pressure, the strain difference exhibits minimal changes with the increase in corrosion degree, while under bending moment loading, the strain difference escalates proportionally with corrosion progression. Consequently, strain induced by bending moment loading solely characterizes the corrosion degree. Moreover, the optimal placement for FBG sensors is identified at the extrados of the pipe elbow, where strain is most prominent. These insights enhance comprehension of strain-corrosion dynamics in pipe elbows, offering valuable guidance for developing an FBG-based monitoring system for real-time corrosion tracking and predictive maintenance of pipeline infrastructures.

Advancements in Battery Monitoring: Harnessing Fiber Grating Sensors for Enhanced Performance and Reliability.

Batteries play a crucial role as energy storage devices across various industries. However, achieving high performance often comes at the cost of safety. Continuous monitoring is essential to ensure the safety and reliability of batteries. This paper investigates the advancements in battery monitoring technology, focusing on fiber Bragg gratings (FBGs). By examining the factors contributing to battery degradation and the principles of FBGs, this study discusses key aspects of FBG sensing, including mounting locations, monitoring targets, and their correlation with optical signals. While current FBG battery sensing can achieve high measurement accuracies for temperature (0.1 °C), strain (0.1 µÎµ), pressure (0.14 bar), and refractive index (6 × 10-5 RIU), with corresponding sensitivities of 40 pm/°C, 2.2 pm/µÎµ, -0.3 pm/bar, and -18 nm/RIU, respectively, accurately assessing battery health in real time remains a challenge. Traditional methods struggle to provide real-time and precise evaluations by analyzing the microstructure of battery materials or physical phenomena during chemical reactions. Therefore, by summarizing the current state of FBG battery sensing research, it is evident that monitoring battery material properties (e.g., refractive index and gas properties) through FBGs offers a promising solution for real-time and accurate battery health assessment. This paper also delves into the obstacles of battery monitoring, such as standardizing the FBG encapsulation process, decoupling multiple parameters, and controlling costs. Ultimately, the paper highlights the potential of FBG monitoring technology in driving advancements in battery development.

Accurate wavelet thresholding method for ECG signals.

Current wavelet thresholding methods for cardiogram signals captured by flexible wearable sensors face a challenge in achieving both accurate thresholding and real-time signal denoising. This paper proposes a real-time accurate thresholding method based on signal estimation, specifically the normalized ACF, as an alternative to traditional noise estimation without the need for parameter fine-tuning and extensive data training. This method is experimentally validated using a variety of electrocardiogram (ECG) signals from different databases, each containing specific types of noise such as additive white Gaussian (AWG) noise, baseline wander noise, electrode motion noise, and muscle artifact noise. Although this method only slightly outperforms other methods in removing AWG noise in ECG signals, it far outperforms conventional methods in removing other real noise. This is attributed to the method's ability to accurately distinguish not only AWG noise that is significantly different spectrum of the ECG signal, but also real noise with similar spectra. In contrast, the conventional methods are effective only for AWG noise. In additional, this method improves the denoising visualization of the measured ECG signals and can be used to optimize other parameters of other wavelet methods to enhancing the denoised periodic signals, thereby improving diagnostic accuracy.

Effects of dietary vitamin K3 supplementation on production performance, egg quality, vitamin K-dependent proteins, and antioxidant properties in breeding geese during the laying period.

The aim of this work was to investigate the effects of dietary vitamin K3 (VK3) supplementation on production performance, egg quality, vitamin K-dependent proteins, and antioxidant properties in breeding geese during the laying period. A total of one hundred twenty 82-wk-old Wulong geese with similar body weights were randomly divided into 6 groups with 4 replicates and 5 geese each (1 male and 4 female). The geese in the control group were fed a basal diet, and the geese in the treatment groups were fed diets supplemented with different levels of VK3 (2.5, 5.0, 7.5, 10.0, and 12.5 mg/kg) for 11 wk. Dietary VK3 supplementation linearly and quadratically increased feed intake, egg mass, egg weight, and egg production (P < 0.05). Increasing VK3 levels linearly and quadratically increased albumen height, shell thickness and Haugh unit of eggs (P < 0.05). VK3 reduced osteocalcin (OC) and uncarboxylated osteocalcin (ucOC) levels in the serum. Dietary VK3 addition linearly decreased serum malondialdehyde (MDA) levels (P < 0.01). There was linear and quadratic effect in the activity of serum total superoxide dismutase (T-SOD) (P < 0.01), and linear effect in serum total antioxidant capacity (T-AOC) (P < 0.01). In conclusion, dietary VK3 supplementation enhanced the production performance, egg quality, vitamin K-dependent proteins, and antioxidant properties in breeding geese during the laying period. The optimal dose of dietary VK3 supplementation was 10.0 mg/kg.

Effects of dietary nicotinic acid supplementation on meat quality, carcass characteristics, lipid metabolism, and tibia parameters of Wulong geese.

The purpose of this study was to evaluate the effects of nicotinic acid (NA) supplementation on the meat quality, carcass characteristics, lipid metabolism, and tibia parameters in Wulong geese. A total of 360 twenty-nine-day-old Wulong geese were randomly divided into 6 treatments, and each treatment included 6 pens with 10 birds per pen. Birds were fed a basal diet supplemented with 0, 20, 40, 60, 80, or 100 mg/kg NA for 12 wk. Dietary NA supplementation linearly decreased L* value and increased pH and water-holding capacity in the breast muscle (P < 0.05). Increasing NA levels linearly and quadratically decreased shear force of breast muscle (P < 0.001). Dietary NA supplementation linearly reduced the thickness of subcutaneous fat plus the skin and percentage of abdominal fat, and enhanced the width of intermuscular fat band (P < 0.001). Dietary NA addition linearly and quadratically increased intramuscular fat (IMF) content (P ≤ 0.001). Increasing NA levels decreased serum total cholesterol and low-density lipoprotein cholesterol levels and increased serum lipase activity and hepatic mRNA expression of lipoprotein lipase in a linear manner (P < 0.05). There were linear and quadratic effects in serum triglycerides and high-density lipoprotein cholesterol (HDL-C) levels and malate dehydrogenase activity with the NA addition (P < 0.05). Feeding the NA-supplemented-diets linearly increased tibia length, circumference, fat-free dry weight, and ash content (P < 0.001). There were linear and quadratic increases in Ca and P contents with the NA supplementation (P < 0.05). According to the quadratic regression analyses fitted to shear force, IMF content, serum triglycerides and HDL-C levels, and tibial Ca and P contents, the optimal dietary NA supplementation was 80 to 90 mg/kg. In conclusion, NA addition enhanced meat quality and IMF content, regulated lipid metabolism, and increased tibia quality of Wulong geese. The dosage of 80 mg/kg NA in Wulong geese aged 5 to 16 wk was recommended.

Wideband-tunable nanotube Q-switched low threshold erbium doped fiber laser.

An all-fiber passively wideband-tunable nanotube Q-switched low threshold erbium doped fiber laser is presented. With a low insertion loss carbon nanotube based saturable absorber, C- and L-band tunable Q-switched lasers are achieved by tuning the transmission wavelength of one C-band tunable filter and the other L-band one, respectively. The threshold of the Q-switched operation is only 12.8 mW. The self-mode-locking effect on the Q-switching can be effectively reduced by introducing a spatial hole burning effect with two optical circulators. The tunable wavelength range of the Q-switching laser can be changed by inserting a variable optical attenuator in the laser cavity to tune the gain spectrum.

Switchable dual-wavelength single-longitudinal-mode erbium-doped fiber laser using an inverse-Gaussian apodized fiber Bragg grating filter and a low-gain semiconductor optical amplifier.

We present a stable and switchable dual-wavelength erbium-doped fiber laser. In the ring cavity, an inverse-Gaussian apodized fiber Bragg grating serves as an ultranarrow dual-wavelength passband filter, a semiconductor optical amplifier biased in the low-gain regime reduces the gain competition of the two wavelengths, and a feedback fiber loop acts as a mode filter to guarantee a stable single-longitudinal-mode operation. Two lasing lines with a wavelength separation of approximately 0.1 nm are obtained experimentally. A microwave signal at 12.51 GHz is demonstrated by beating the dual wavelengths at a photodetector.

Simultaneous strain and temperature measurement using a compact photonic crystal fiber inter-modal interferometer and a fiber Bragg grating.

An all-fiber sensor scheme for simultaneous strain and temperature measurement is presented. The sensing head is formed by serially connecting a polarization maintaining photonic-crystal-fiber-based inter-modal interferometer (IMI) with a fiber Bragg grating (FBG). The IMI, exhibiting an opposite strain response as compared to that of the FBG, is highly sensitive to strain, while it is insensitive to temperature. This has potential for improving the strain and temperature measurement resolutions. A sensor resolution of ±8.3 µÎµ in strain and ±2 °C in temperature are experimentally achieved within a strain range of 0-957.6 µÎµ and a temperature range of 24 °C-64 °C, respectively.

Inverse-Gaussian apodized fiber Bragg grating for dual-wavelength lasing.

A fiber Bragg grating (FBG) with an inverse-Gaussian apodization function is proposed and fabricated. It is shown that such a FBG possesses dual-wavelength narrow transmission peaks and the wavelength spacing between the two peaks is easily controllable during fabrication. Incorporating such a FBG filter into a fiber laser with a linear cavity, we obtain stable dual-wavelength emission with 0.146 nm wavelength spacing. This arrangement provides a simple and low cost way of achieving dual-wavelength fiber laser operation.

Strain-insensitive and high-temperature long-period gratings inscribed in photonic crystal fiber.

We fabricate and demonstrate strain-insensitive and high-temperature long-period gratings in endlessly single-mode photonic crystal fiber by use of focused pulses of a CO2 laser and a periodic stress relaxation technique without geometrical deformation and elongation of the fiber. The thermal dependence of mode coupling at 1299.59 nm is 10.9 pm/degrees C from 24 to 992 degrees C, whereas the coefficient of strain sensitivity is -0.192 pm/muepsilon up to the maximum strain of 2.74%epsilon. It is found for what is believed to be the first time that, in contrast with the traditional fiber case, the coupling resonance shifts toward shorter wavelengths under applied strain, indicating that the refractive index of the core is decreased as a result of the rebuilding of tension attributed to the stress-elastic effect, and the cladding modes is highly dispersive because of airholes arranged in the fiber cladding.

Proteomic analysis of nuclear matrix proteins during arsenic trioxide induced apoptosis in leukemia K562 cells.

BACKGROUND: Arsenic trioxide (As2O3) has been identified as a very potent anti-acute leukemic agent. However its role in apoptosis needs to be elucidated. As2O3 interferes with the proliferation and survival of tumor cells via a variety of mechanisms. Drug-target interactions at the level of nuclear matrix (NM) may be critical events in the induction of cell death by As2O3. This study dealt with As2O3-target interactions at the level of NM in chronic myelogenous leukemia cell line K562 by proteomics. METHODS: K562 cells were cultured in MEM and treated with different concentrations of As2O3. The nuclear matrix proteins were analyzed by high-resolution two-dimensional gel electrophoresis and computer-assisted image analysis. RESULTS: As2O3 significantly inhibited the growth of chronic myelogenous leukemia cell line K562 at low concentrations. While more than 200 protein spots were shared among the nuclear matrices, about 18 distinct spots in the nuclear matrices were found characteristic for As2O3 treated cells. CONCLUSIONS: As2O3 induces apoptosis in K562 cells in a dose and time-dependent manner. Our results demonstrated that for the detection of the onset of apoptosis, the alteration in the composition of nuclear matrix proteins was a more sensitive indicator than nucleosomal DNA fragmentation test. These results indicated that As2O3 might be clinically useful in the treatment of chronic myelogenous leukemia. The changes of nuclear matrix proteins in the treated cells can be used as a useful indicator for this treatment.

[Influence of transfected EGFR-cDNA on bcl-2 and Bax in glioblastoma cells].

OBJECTIVE: To investigate the correlation of bcl-2 and Bax protein with nuclear matrix in glioblastoma cell line U87 as well as the effect of EGFR-cDNA transfection on the expression of bcl-2 and Bax in U87 cells. METHODS: The correlation of bcl-2 and Bax protein with nuclear matrix in glioblastoma cell line U87 was studied by confocal microscopy and Western blot. The expression of bcl-2 and Bax in EGFR-cDNA transfected and untransfected glioblastoma cell lines was studied by Western blot. RESULTS: Confocal microscopic images showed that bcl-2 protein was localized in the periphery of the nuclear matrix and Bax in the nuclear matrix. A 26 kDa bcl-2 band and a specific band of Bax at about 66 000 were detected in nuclear matrix proteins by western blot. The expression of bcl-2 was lower but that of Bax was higher in EGFR-cDNA transfected cells than the control. CONCLUSION: Bcl-2 and Bax, being nuclear matrix associated proteins, are probably involved in the EGFR-cDNA induced malignant conversion of glioblastoma cells by introducing EGFR cDNA into the tumor cells.