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This study proposes an eddy current-based tensile force estimation technique for a post-tensioning (PT) tendon under varying temperature conditions. The tensile force in the internal PT tendon is inferred by measuring the compressive stress on the external anchor head. A dual-coil probe consisting of two identical eddy current coils with orthogonal orientations measures the unidirectional loading level based on the piezoresistive effect. The temperature effect is eliminated using identical eddy current signal alternations in the coils under temperature variation. The performance of the proposed technique was evaluated by estimating the tensile force of a PT tendon under various loading and temperature conditions. The uniqueness of this study lies in the (1) design and fabrication of a dual-coil probe for unidirectional loading level estimation, (2) elimination of the effect of temperature on tensile force estimation, and (3) experimental validation under various loading and temperature conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Functional food ingredients in functional food protect the body against various diseases through bio-functional activities. • Bioactive peptides purified from animal sources consider functional food ingredients. • Different bioactive peptides have been purified from duck processing by-products. Foods that contain components known for their health-promoting qualities, beyond just their nutritional value, are called functional foods. These particular components are referred to as functional food ingredients. Mainly, the bioactive peptides purified from food materials, including animal sources, have been identified as such functional food ingredients. In this review, we discuss the purification process of bioactive peptides from duck meat, egg and processing by-products. Additionally, we highlight the technologies currently used to purify bioactive peptides from sources other than duck, including modern computational techniques like insilico methodology or bioinformatics as well as and methods to enhance the purification process. These techniques can be applied in the future to purify bioactive peptides from duck in order to boost the efficacy of bioactive peptide purification. Furthermore, we summarize the bio-functional activities of bioactive peptides, purified from duck, which help to protect the body against various diseases, thereby proving their potential to be functional food ingredients. [ABSTRACT FROM AUTHOR]

• We investigated the inhibitory effects of cirsiliol on IL-6/STAT3 activation. • Cirsiliol inhibited the expression of p-JAK2 and p-ERK but not the interaction of IL-6 and IL-6R. • Cirsiliol could serve as a natural immunoregulatory compound. Many studies have identified and described various medicinal effects of cirsiliol. Here, we investigated the signaling pathway involved in the anti-inflammatory effects of cirsiliol on IL-6-induced activity. Cirsiliol showed no cytotoxicity and inhibited pSTAT3-induced luciferase activity. At the molecular level, cirsiliol suppressed the expression of IL-6-induced inflammatory marker genes such as CRP, IL-1β, ICAM-1 and SOCS3, IL-6-induced activation of Jak2, gp130, STAT3 and ERK and nuclear translocation of STAT3, as measured by PCR, immunofluorescence staining and western blot analysis. However, the interaction between IL-6 and its receptor was not affected by cirsiliol treatment. These results indicate that cirsiliol attenuates IL-6-induced cellular signaling by regulating Jak2 phosphorylation. Therefore, cirsiliol could be a therapeutic agent for IL-6-related inflammatory diseases. [ABSTRACT FROM AUTHOR]

This study presents an online fatigue crack failure warning system that can provide a warning of imminent failure of an aluminum plate structure with an initial notch when the plate is subject to constant-amplitude cyclic loading. For real-time warning, three piezoelectric transducers (PZT) are mounted on the surface of the structure for ultrasonic generation and sensing. Two sinusoidal input signals at distinct frequencies are applied respectively to two PZTs, and corresponding responses are measured by the third PZT. Ultrasonic waves cause crack closing and opening at the presence of a fatigue crack, and nonlinear ultrasonic modulation components appear at sum and difference of the input frequencies. The amplitudes of nonlinear ultrasonic modulation components initially increase as a fatigue crack grows. However, when the maximum stress intensity factor at the crack tip reaches the fracture toughness value of material, the modulation amplitudes suddenly decrease. The proposed failure warning system provides a failure warning by studying the patterns of measured nonlinear modulation components with respect to the fatigue crack growth. The performance of the proposed failure warning system is examined using aluminum plate specimens with various thicknesses and material properties. [ABSTRACT FROM AUTHOR]

Portulaca oleracea L. ( P . oleracea ) is an herb that is widely used in traditional medicine to treat various diseases. However, its effects on inflammatory diseases, such as inflammatory bowel disease (IBD), are not yet well characterized. Here, we investigated the impact of the ethyl acetate (EtOAc) and ethanol (EtOH) extracts of P . oleracea on lipopolysaccharide (LPS)-induced inflammatory responses and phosphorylation of ERK, JNK, and p38 expression in RAW264.7 macrophages. In addition, the inhibitory effects of these extracts and fractions on 3% dextran sulphate sodium (DSS)-induced ulcerative colitis were examined using an ICR mouse model. DSS-induced colitis, including body weight loss, reduced colon length, and histological colon injury, was significantly ameliorated in mice fed the P . oleracea extracts (200 and 500 mg/kg). In particular, P . oleracea extracts also inhibited pro-inflammatory cytokine (TNF-α, IL-6, and 1L-1β) production in mice with DSS-induced colitis; the P . oleracea extracts displayed higher and/or similar inhibitory activity to sulfasalazine at high concentrations. Furthermore, the chemical structures of active compounds separated from the EtOAc extract of P . oleracea were elucidated using nuclear magnetic resonance (NMR) spectroscopy (see Figure in supplementary materials), resulting in the identification of three known compounds. Among these active compounds, cis - N -feruloyl-3′-methoxytyramine ( 2 ) exhibited the strongest effects on preventing DSS-induced IBD in animal models. Thus, extract of P . oleracea and their active compounds represents a new therapeutic approach for patients with inflammatory bowel diseases. [ABSTRACT FROM AUTHOR]

This paper presents an automated hidden void detection and quantification technique for inspecting triplex bonding layers in liquefied natural gas (LNG) carriers using active lock-in thermography. Hidden voids are first detected and visualized by an amplitude image and a series of binary image processing. Then, the sizes of the detected voids are quantified using an empirical mapping function, relating the detected void sizes to the void sizes obtained by an independent X-ray testing. The performance of the proposed technique is blind tested using two triplex specimens. The experimental results reveal that the hidden voids can be successfully detected and quantified. [ABSTRACT FROM AUTHOR]

This paper presents a complete noncontact fatigue crack visualization technique based on nonlinear ultrasonic wave modulation and investigates the main source of nonlinear modulation generation. Two distinctive frequency input signals are created by two air-coupled transducers and the corresponding ultrasonic responses are scanned using a 3D laser Doppler vibrometer. The effectiveness of the proposed technique is tested using aluminum plates with different stages of fatigue crack formation such as micro and macro-cracks. Furthermore, the main source of nonlinear modulation is discussed based on the visualization results and the microscopic images. [ABSTRACT FROM AUTHOR]

Abstract: The impedance based damage detection technique utilizing piezoelectric materials has become a promising and attractive tool for structural health monitoring due to its high sensitivity to small local damage. However, impedance signals are also sensitive to time-varying environmental and operational conditions, and these ambient variations can often cause false-alarms. In this study, a data normalization technique using Kernel principal component analysis (KPCA) is developed to improve damage detectability under varying temperature and external loading conditions and to minimize false-alarms due to these variations. The proposed technique is used to detect bolt loosening within a metal fitting lug, which connects a composite aircraft wing to a fuselage. Model and full-scale tests are performed under realistic temperature and loading variations to validate the proposed technique. The uniqueness of this paper lies in that (1) a data normalization technique tailored for impedance based damage detection has been developed (2) multiple environmental parameters, such as temperature and static/dynamic loading are considered simultaneously for data normalization and (3) the effectiveness of the proposed technique is examined using data collected from a full-scale composite wing specimen with a complex geometry. [Copyright &y& Elsevier]

Abstract: In this paper, we present a competent mobility scheme based on Proxy Mobile IPv6 for enabling the global mobility support in the next-generation mobile networks. With the proposed mobility scheme, mobile hosts can hand off between local mobility domains with lower signaling loads than Mobile IPv6 even though the mobile hosts do not have any mobility stack. In the proposed mobility scheme, we introduce two type modes: tunneling mode and active binding update mode. The tunneling mode achieves the global mobility support by packet tunneling. On the other hand, in the active binding update mode, a local mobility agent sends binding update messages on behalf of a mobile host whenever the mobile host hands off across local mobility domains to accomplish the global mobility support. The results of performance evaluation demonstrate that the proposed active binding update mode reduces the signaling cost compared with Mobile IPv6 and the tunneling mode. However, the proposed tunneling mode also provides the lower signaling cost while the subnet crossing rate is low and the session size is small. [Copyright &y& Elsevier]

Nonlinear ultrasonic modulation, a promising fatigue-crack-detection technique, is investigated with various frequency combinations, and an algorithm that can comprehensively analyze the results by comparison with ambient noise is proposed. The magnitudes at the 1st sideband frequencies of the Fourier-transformed result and surrounding noises are measured. Experiments with aluminum specimens before and after fatigue-crack generation show that cracks are detected correctly in both pristine and damaged specimens. When the developed crack-detection method is employed while applying an external force, specimen defects are correctly detected, although the magnitudes of modulated waves decreased. The time and effort required for monitoring the structure's health can be reduced by using ambient noise as a reference. [ABSTRACT FROM AUTHOR]

• Non-contact fatigue crack detection technique for rotating steel shafts is developed. • Spectral correlation between ultrasonic modulation components is computed. • Spectral correlation measurements provide earlier crack detection than conventional nondestructive techniques. In this study, a noncontact fatigue crack detection technique for rotating steel shafts is developed using air-coupled transducers (ACTs). Two ACTs are used for ultrasonic wave generation at two distinctive frequencies, and a third ACT is used for sensing. The proposed technique is based on the premise that nonlinear ultrasonic modulation appears at the sum and difference of two input frequencies in the presence of any crack due to crack opening and closing. First, the spectral correlation (SC) between ultrasonic modulation components at the sum and difference of two input frequencies is computed. Next, an outlier analysis is performed on spectral correlations obtained from different input frequency combinations for automated crack diagnosis. To the best of the authors' knowledge, this is the first study in which a sub-millimeter fatigue crack is detected in a rotating steel shaft using noncontact transducers. In this study, real fatigue cracks on half-scale and full-scale steel shafts used in automobile assembly lines are produced through cyclic loading tests, and the performance of the proposed technique is experimentally validated using ultrasonic response data obtained from the half-scale and full-scale steel shaft specimens. The formation of fatigue cracks is confirmed using fluorescent magnetic particle inspection (MPI), fluorescent penetrant inspection (FPI), and metallographic analysis. [ABSTRACT FROM AUTHOR]

The demand for metal additive manufacturing (AM), also known as three-dimensional (3D) printing, is increasing owing to its ability to produce components with complex shapes, heterogeneous material properties, low material waste, etc. However, for broader acceptance of metal AM, quality assurance of mechanical properties, such as elastic (Young's) modulus, Poisson's ratio, and ductility, is becoming critical in additively manufactured components. This study proposes a non-contact, non-destructive and automated eddy-current technique for yield strength estimation of additively manufactured Ti–6Al–4V components with the potential for online operation during metal AM. After conducting the eddy-current measurement at a specific inspection point within the Ti–6Al–4V component, the relationship between the eddy-current phase value and electrical conductivity is established. Subsequently, the yield strength of the Ti–6Al–4V component is estimated by utilizing the analytical relationship between yield strength and electrical conductivity, which is based on Andrew's research and the Hall–Petch relationship. For experimental validation, Ti–6Al–4V test specimens with different electrical conductivities (yield strengths) were fabricated by adjusting the cooling rate during metal direct energy deposition AM. Then, the yield strengths estimated using the proposed technique were compared with those obtained using conventional destructive tensile tests. The results show that the proposed technique can estimate the yield strength with an error rate of less than 8%. The uniqueness of this study lies in (1) the theoretical derivation of the relationship between the eddy-current phase value and yield strength, (2) non-destructive, non-contact, and automated estimation of the yield strength using eddy-current measurements, and (3) performance evaluation using additively manufactured Ti–6Al–4V specimens with different yield strengths. [ABSTRACT FROM AUTHOR]

Worldwide demand for the seafood is increasing due to ongoing population increase. Meeting of that demand with environmentally sustainable and good quality seafood is suffering and the reliance on traditional aquaculture and fishing methods is insufficient to supply demand. Therefore, it is crucial to use modern technology, like cell-based cultured seafood, to produce seafood. In addition to addressing the food shortage, seafood produced through these advanced technologies plays an important role in addressing various environmental, health, welfare, and ethical concerns associated with traditional aquaculture. This includes combating issues such as pollution, severe illnesses like cancer and cardiovascular diseases, zoonotic diseases, and the problem of overfishing. Although the trend of cell-based seafood has been established for several years, it has not grown as much as meat manufacturing and is not widely discussed. Consequently, to improve the production of substitute seafood, it is necessary to understand and overcome the associated limitations and challenges of these technologies. [ABSTRACT FROM AUTHOR]

• Development of ultrasonic-based tensile force estimation technique. • Investigation and compensation of the temperature effect on ultrasonic response. • Tensile force estimation under varying temperature conditions. • Application to the cylindrical rod specimen identical to the those used in a real suspension bridge. This study presents the development of a tensile force estimation technique based on the ultrasonic bulk wave for cylindrical rod in a suspension bridge anchor system. Three piezoelectric macro fiber composites (MFC) transducers are installed on the surface of a cylindrical rod specimen for the generation and sensing of ultrasonic bulk waves. Ultrasonic responses are obtained at various tensile force levels and temperature conditions, and the relationship between the time lag of the ultrasonic response and the tensile force is established. In particular, the temperature effect on the tensile force estimation is theoretically derived and compensated for field applications. The originality of this study includes (1) theoretical derivation and investigation of the relationship between an applied tensile force level and the time lag of an ultrasonic response considering the variations of temperature, density, and elastic modulus, (2) development of a tensile force estimation and temperature compensation technique without temperature measurement, and (3) application to the tensile force estimation of the rod structure commonly used in a suspension bridge anchor system. The performance of the developed tensile force estimation technique was examined based on mock-up experiments of the rod structure of a real suspension bridge anchor system. [ABSTRACT FROM AUTHOR]

Abstract: This study proposes a new damage detection technique so that delamination in composite plates can be detected by comparing pitch-catch Lamb wave signals obtained from a piezoelectric transducer (PZT) network without using their own baseline signals obtained from the pristine condition. The proposed technique is based on the premise that the fundamental anti-symmetric (A 0) mode slows down when it passes through a delamination area while the speed of the fundamental symmetric mode is little affected by delamination. First, the A 0 mode in each path is isolated using a mode extraction technique. This mode extraction technique is able to isolate the A 0 mode without frequency or transducer size tuning using dual PZTs composed of concentric ring and circular PZTs. Once the A 0 modes are extracted from all paths in the transducer network, the relative time delay of the A 0 mode in each path with respect to the other paths is defined as a delamination sensitive feature. Then, an instantaneous outlier analysis is developed and performed on the damage sensitive feature to identify the path(s) affected by the delaminated region(s). Because the relative time delays of the A 0 modes are instantaneously compared, robust delamination detection is achieved even under varying temperature conditions. [Copyright &y& Elsevier]

The large emission of volatile organic compounds (VOCs) is an important environmental issue in Seoul, the capital of South Korea. However, the spatial distribution of VOC emissions has not yet been clearly revealed. In this study, passive air samplers (PASs) were seasonally deployed to measure 50 VOCs at 26 urban, 4 road, and 6 background sites in Seoul. Among the target compounds, toluene (summer: 8.72 μg/m3; winter: 5.47 μg/m3), ethyl acetate (summer: 2.36 μg/m3; winter: 3.51 μg/m3), and ethylbenzene (summer: 1.72 μg/m3; winter: 0.88 μg/m3) exhibited higher mean concentrations than other compounds. Printing offices and industrial facilities seem to have strong influences on the VOC levels in the center and southwest of Seoul, respectively. Diagnostic ratios indicated that the main sources of VOCs were related to local volatilization in summer and vehicular exhaust and transport from other areas in winter. Positive matrix factorization (PMF) suggested four major sources of VOCs: residential/commercial solvents for printing and painting (Factor 1); transport from other areas (Factor 2); industrial solvents for painting, manufacturing, and cleaning (Factor 3); and gasoline/diesel vehicular exhausts (Factor 4). Factors 1 and 3 were dominant in summer, and Factors 2 and 4 were dominant in winter. In conclusion, the seasonal meteorological conditions (e.g., temperature and wind patterns) were found to play an important role in the spatial distribution of VOCs in Seoul, and solvent use was a predominant source. Image 1 • Passive air samplers were deployed at 36 sites in Seoul, Korea in summer and winter. • Toluene, ethyl acetate, and ethylbenzene were dominant compounds in both seasons. • The high concentrations of VOCs were observed in the center and southwest of Seoul. • The main source of VOCs in summer was the local volatilization of solvents. • Vehicular exhaust and transport from other areas were dominant in winter. [ABSTRACT FROM AUTHOR]

Seoul, the capital of South Korea, is one of the largest megacities in northeast Asia. Previous studies have monitored atmospheric polycyclic aromatic hydrocarbons (PAHs) in Seoul, but few have produced highly spatially resolved data. In this study, a total of 144 polyurethane foam-passive air samplers (PUF-PASs) were deployed at 36 sites (4 road, 26 urban, and 6 background sites) in Seoul during the summer of 2016 and the winter of 2017. The concentrations of Σ 13 PAHs fell within a range of 2.6–49.9 ng/m3 in summer and 15.5–77.8 ng/m3 in winter. Low-molecular-weight PAHs with 3–4 rings were dominant (accounting for about 97% of all PAHs) at all sampling sites in both seasons compared to high-molecular-weight PAHs with 5–6 rings. Phenanthrene was the most abundant individual compound, accounting for 35–54% and 42–52% of the total PAHs in summer and winter, respectively. The spatial distribution of PAHs was determined by traffic, domestic heating, topography, transport, and meteorological conditions. The concentration of PAHs at the road sites was higher than at the urban and background sites, indicating that vehicular exhaust was a major source in both seasons. In addition, diagnostic ratios and principal component analysis revealed the influence of various sources, such as gasoline and diesel emissions and coal and biomass combustion. Backward air trajectory analysis highlighted the influence of long-range transport from northern China and North Korea during the winter, whereas the influence of local emissions and satellite cities appeared to dominate during the summer. In conclusion, passive air sampling was successfully employed to identify major sources of PAHs in an Asian megacity, indicating that it could produce data with a high spatial resolution for use in human risk assessment and air monitoring networks. • Passive air sampling was conducted at 36 sites in Seoul, Korea in summer and winter. • The mean concentration of PAHs in winter was higher than that in summer. • Road sites exhibited higher levels of PAHs than urban and background sites. • The influence of long-range transport was evident during the winter. • The influence of local emissions and satellite cities was dominant during the summer. [ABSTRACT FROM AUTHOR]