Distributed optical fiber sensors (DOFS) have been attracted significant attention from geotechnical engineering communities for a few decades. Innovative development of structural design, ...encapsulation and implementation methods of optical fiber sensors leads to many new applications in geotechnical monitoring field. This paper presents a comprehensive review of Brillouin based DOFS for health monitoring of various geotechnical structures include geotextiles, soil nails, anchors, pipelines, piles, retaining walls, tunnels, and landslides. Recent application status of using two successful commercialized technologies including Brillouin Optical Time Domain Reflectometry (BOTDR) and Brillouin Optical Time Domain Analysis (BOTDA) for geotechnical health monitoring was reviewed and discussed in details. Particular emphasis was given to sensor design, encapsulation, and installation methods of DOFS in various successful geotechnical applications. Comparison analysis regarding typical advantages and limitations of different technologies (DOFS, fiber Bragg grating sensors, and conventional sensors) for geotechnical health monitoring was also presented and discussed in this paper.
The development of efficient sequencing techniques has resulted in large numbers of genomes being available for evolutionary studies. However, only one genome is available for all amphibians, that of ...Xenopus tropicalis , which is distantly related from the majority of frogs. More than 96% of frogs belong to the Neobatrachia, and no genome exists for this group. This dearth of amphibian genomes greatly restricts genomic studies of amphibians and, more generally, our understanding of tetrapod genome evolution. To fill this gap, we provide the de novo genome of a Tibetan Plateau frog, Nanorana parkeri , and compare it to that of X. tropicalis and other vertebrates. This genome encodes more than 20,000 protein-coding genes, a number similar to that of Xenopus . Although the genome size of Nanorana is considerably larger than that of Xenopus (2.3 vs. 1.5 Gb), most of the difference is due to the respective number of transposable elements in the two genomes. The two frogs exhibit considerable conserved whole-genome synteny despite having diverged approximately 266 Ma, indicating a slow rate of DNA structural evolution in anurans. Multigenome synteny blocks further show that amphibians have fewer interchromosomal rearrangements than mammals but have a comparable rate of intrachromosomal rearrangements. Our analysis also identifies 11 Mb of anuran-specific highly conserved elements that will be useful for comparative genomic analyses of frogs. The Nanorana genome offers an improved understanding of evolution of tetrapod genomes and also provides a genomic reference for other evolutionary studies.
Significance We provide a de novo genome of the Tibetan frog, Nanorana parkeri , and conduct a series of comparisons with other vertebrates. Approximately one-half of the genome of Nanorana consists of transposable elements (TEs). The frequencies and distributional patterns of TEs differ considerably between Nanorana and Xenopus , the only other amphibian for which a genome has been sequenced. The genomes of these two frogs exhibit substantial homologous synteny blocks with rare interchromosomal and intrachromosomal rearrangements. We also identify 11 Mb of amphibian-specific conserved elements comprising 217 genes. These highly conserved genes provide a basis for comparative genomic analyses throughout frogs.
•Prefabricated RC column with replaceable steel fuse column-base connections proposed.•Stable hysteretic response was exhibited and repairability was achieved by replaceable steel fuses and padding ...blocks.•Lateral load capacity increased by 4.9% and 4.7% with increase in axial load and fuse areas considered.•Ultra-high toughness cementitious composite padding blocks found to be efficient in delaying buckling of steel fuses.•Two simplified theoretical models established to predict the flexural response of hybrid columns.
A new prefabricated RC column with replaceable column-base connection was proposed for moment-resisting frames. The column-base connection was assembled with replaceable steel fuses and padding blocks, which can be easily replaced after an earthquake, to accommodate inelastic deformation. Eight full-scale column specimens were tested to evaluate the effectiveness of various parameters on the seismic performance under lateral loads. The experimental results showed that the column-base connections exhibited stable hysteretic behavior in terms of strength, stiffness and energy dissipation. The lateral load capacity increased with increase in cross-sectional area of steel fuses (1200–1520 mm2) and axial load ratio (0.14–0.24). The seismic performance before and after the replacement of the damaged components was found to be almost identical which indicated that the replaceable column-base connection is feasible and effective. An idealized moment-rotation theoretical model and a simplified 2D nonlinear theoretical model were further developed to predict the flexural response of the proposed columns. Comparison of theoretical model responses with the experiment results showed satisfactory results in predicting the lateral load behavior. Both the models provide a reference for the design procedure and practical applications of the replaceable column-base connection.
The influence of ultrasonic pretreatment on the release and antioxidant activity of potential antioxidant peptides after in-vitro simulated gastrointestinal digestion of β-lactoglobulin (BLG) were ...measured by HPLC-MS/MS, chemical and cellular-based assays. The gastrointestinal digest was fractionated into four fractions by Sephadex G-25 gel filtration column, and fractions showed a considerable ABTS·
scavenging ability. The fraction with the strongest antioxidant activity was produced by ultrasonicated BLG after gastrointestinal digestion, which relies on ultrasonic-promoted proteolysis to produce many small-molecule antioxidant peptides. The best active fraction has better cellular antioxidant activity and protection of H
O
-induced oxidative HepG2 cell model, which significantly increases the activities of antioxidant enzyme, and is concentration-dependent. HPLC-MS/MS analysis showed that there were more potential antioxidant peptides in the best active fraction. This research will provide a basis for the further application of ultrasonic in dairy products, which can promote the release of more potential antioxidant peptides-derived from gastrointestinal digestion.
•Tests on flexural behavior of strengthened stone slabs with NSM steel wire ropes.•Effect of different parameters on bearing capacity of strengthened stone slabs.•Calculation models to evaluate the ...flexural strength of strengthened stone slabs.
In order to enhance the flexural behavior of the stone building structures, a technique of strengthening stone slabs using prestressed near-surface mounted (NSM) steel wire ropes is proposed. Six strengthened stone slabs were tested under four-point bending by considering the reinforcement ratio, level of prestressing and bonding agent as testing parameters. Additionally, a bare stone slab was also involved in the test program for comparison purpose. It was found from the experimental investigation that, the strengthened stone slabs exhibited ductile failure mode with visible deflection. Formation of multiple cracks in both constant bending zone and flexural-shear zone was observed in the strengthened stone slabs. As expected, abrupt fracture occurred in the bare stone slab as soon as the cracking moment was attained. Besides the improved failure mode, the flexural strength of the strengthened specimens was improved significantly and tended to enhance with the increase of prestressing level. No end slip of the steel wire ropes was observed highlighting the favourable bond characteristics between the constituent elements (steel wire ropes and stone slab). A simplified theoretical model to be used to predict the flexural strength of the strengthened stone slabs was developed and assessed.
This paper proposes a novel reinforced concrete column-steel beam (RCS) joint suitable for prefabricated hybrid structures. Twelve interior RCS joint subassemblies were tested under cyclic lateral ...loading. The main test parameters include beam-column capacity ratio coefficient (ηbc), joint capacity ratio coefficient (ηj), and thickness (t) of the joint web plate (JWP). The results showed that the proposed joint details ensured good integrity and deformation performance of the RCS joint subassemblies. The ultimate drift ratio of most specimens was up to 4.0%. The capacity ratio coefficients were the main factors affecting the failure mode. For the specimens with ηbc less than 1, the steel beam observed flexural failure mode, and featured stable full hysteretic loops. The specimens with ηbc greater than 1, the RC column observed flexural failure mode and exhibited a stable but slightly pinched hysteretic response. The specimens with ηj of less than 1 observed concrete damage in the joint region and showed a more pinched hysteretic response. The flexural deformation of steel beams and RC columns contributed to the lateral drift of the specimens. No brittle joint shear failure occurred in specimens, which showed that the proposed joint details can meet the requirements of strong joint-weak member in seismic design.
•A new type of RC column-steel beam (RCS) joint is proposed for prefabricated hybrid RCS frames.•Twelve prefabricated RCS joint subassemblies are tested under reversed cyclic loading.•Evaluating the influence of capacity ratio coefficient on the failure modes and displacement components of specimens.•Investigating the influence of failure modes on the seismic performance of RCS joints.•All the specimens show excellent structural integrity and seismic behavior.
Titanium dioxide/carbon (TiO2/C) composites are generally prepared from fossil resources, which contradicts carbon neutrality science and economics. This study used sawdust as the feedstock to make ...TiO2/C binary composites that were further used to photodegrade methylene blue (MB) under simulated sunlight irradiation. The composites were characterized by SEM, FT-IR, XRD, XPS, TG-DT G, UV–vis, and N2 adsorption-desorption. Carbon primarily existed in the outer layer of the composite, significantly enhancing sensitization. The direct band gap of the TiO2/C-550 composite was 2.7 eV. As a result, the visible light absorption of TiO2 widened, and the charge recombination rate decreased. The degradation ratio of MB aqueous solution reached nearly 100% within 30 min in the presence of TiO2/C-550 composites. Moreover, TiO2/C-550 still maintained about 95% photodegradation efficiency after 5 cycles. Meanwhile, the dominant role of •O2− produced in the reaction has been confirmed through free radical capture experiments. Compared with pure TiO2, the photodegradation performance of MB was significantly improved under visible light irradiation. In addition, the material preparation is green, simple, and low-cost. We can confirm that the TiO2/C composites prepared from waste sawdust had sustainable and efficient advantages, reducing the consumption of fossil resources.
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Attempts on merging isoindigo derivatives with C=N→B–O complex show that there is a glass ceiling for C=N→B–O complex formation and its ability to further enhance the electron-withdrawing capability ...of existing strong acceptors.
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Attempts to merge three isoindigo derivatives, namely diazaisoindigo (DAII), thiazoloisoindigo (TzII) and hydroxyisoindigo (OHII), with CN → B–O complex for stronger acceptors show that only OHII can form stable CN → B–O complexation, however, no obvious electron-withdrawing capability enhancement was observed.
•12 specimens with only the steel plates resisting the axial load were tested.•The buckling modes for different arrangements of tie bars were examined.•The average stress-strain curves of the steel ...plates were investigated.•Simplified equations for estimating the strengths of the steel plates were developed.
Tie bars have been frequently used in square or rectangular concrete-filled steel tubular (CFST) columns and concrete-filled steel plate (CFSP) composite shear walls for delaying local buckling of the steel plates and also improving the concrete confinement. This study investigated the entire response of steel plates in composite members with tie bars. Twelve specimens were designed and tested under axial compression. In these specimens, only the steel plates resisted the axial load, and the concrete was only used to restrain the inward buckling of the steel plates. The effects of the width-to-thickness ratio of the steel plate and the ratio of the vertical spacing of the tie bars to the steel plate width (abbreviated as vertical-spacing-to-width ratio) were investigated. It was found that the increase in the performance of the steel plates due to the tie-bar restraint was quite limited when the vertical-spacing-to-width ratio was 1/2 and became more significant when this ratio decreased to 1/3. The elastic buckling stresses of rectangular plates having boundary conditions similar to those in composite members were computed using the finite element method for further strength evaluation of the steel plates. It was found that the effect of the columns of tie-bars on the elastic buckling stress increased as the vertical-spacing-to-width ratio decreased and was negligible when this ratio was larger than 0.6. Simplified equations for estimating the maximum strength and reserved strength (defined as the average stress corresponding to the average strain of 3%) of the steel plates in composite members with tie bars were developed based on the test results and elastic buckling analyses.
The aim of this cross-sectional study was to examine the mediating effects of individual affect and relationship satisfaction on the relationship between self-esteem and Problematic Internet Use ...(PIU). Affect was measured using the Positive and Negative Affect Schedule (PANAS), relationship satisfaction was assessed using a positive and negative semantic dimension scale, self-esteem was measured using the Rosenberg Self-Esteem Scale, and PIU was measured using the Problematic Internet Use scale with a sample of 507 Chinese university students (Mage = 20.41 years, SD = 2.49). The relationships between the variables were tested using structural equation modelling with a multiple mediation model. The results revealed that negative affect and the negative semantic dimensions of relationship satisfaction mediated the relationship between self-esteem and PIU. The implications of the results and the study’s theoretical contributions are discussed.
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