Sehestedfisher6835

Based on the numerical study, the longitudinal web stiffener could prevent the web buckling of the slender GFRP beam and improved the maximum load by 136%. The maximum load may be further improved by increasing the thickness of the GFRP section and the size of rectangular hollow sections used for strengthening. It was found that the bond-slip at the concrete-GFRP interface affected the shear resistance of concrete-GFRP composite beam.Solute storage and release in groundwater are key processes in solute transport for groundwater remediation and protection. In karst areas where concentrated recharge conditions exist, pollution incidents can easily occur in springs that are hydraulically connected to densely inhabited karst depressions. The intrinsic heterogeneity common in karst media makes modeling solute transport very difficult with great uncertainty. Meanwhile, it is noteworthy that solute storage and release within subsurface conduits and fissures exhibit strong controlling function on pollutant attenuation during underground floods. Consequently, in this paper, we identified and estimated the solute storage and release processes in karst water systems under concentrated recharge conditions. The methodology uses the advection-dispersion method and field tracer tests to characterize solute transport in different flow paths. Two solute transport pathways were established (i.e., linear pathway (direct transport through karst conduits) and dynamic pathway (flow through fissures)). Advection-dispersion equations were used to fit the breakthrough curves in conduit flow, while the volume of solute storage in fissures were calculated by segmenting the best fitting curves from the total breakthrough curves. The results show that, greater recharge flow or stronger dynamic conditions leads to lower solute storage rate, with the storage rate values less than 10% at high water level conditions. In addition, longer residence time was recorded for solute exchange between conduits and fissures at the low water level condition, thereby contributing to a higher solute storage rate of 26% in the dynamic pathway.Conventional synthetic sorbents for oil spill removal are the most widely applied materials, although they are not the optimal choices from an economic and environmental point of view. The use of inexpensive, abundant, non-toxic, biodegradable, and reusable lignocellulosic materials might be an alternative to conventional sorbents, with obvious positive impact on sustainability and circular economy. The objective of this paper was to review reports on the use of natural-based adsorbing materials for the restoration of water bodies threatened by oil spills. The use of raw and modified natural sorbents as a restoration tool, their sorption capacity, along with the individual results in conditions that have been implemented, were examined in detail. Modification methods for improving the hydrophobicity of natural sorbents were also extensively highlighted. Furthermore, an attempt was made to assess the advantages and limitations of each natural sorbent since one material is unlikely to encompass all potential oil spill scenarios. Finally, an evaluation was conducted in order to outline an integrated approach based on the terms of material-environment-economy.Magnetic hydrogels have been commonly used in biomedical applications. As magnetite nanoparticles (MNPs) exhibit peroxidase enzyme-like activity, magnetic hydrogels have been actively used as signal transducers for biomedical assays. Droplet microfluidics, which uses photoinitiated polymerization, is a preferred method for the synthesis of magnetic hydrogels. However, light absorption by MNPs makes it difficult to obtain fully polymerized and homogeneous magnetic hydrogels through photoinitiated polymerization. Several methods have been reported to address this issue, but few studies have focused on investigating the light absorption properties of photoinitiators. In this study, we developed a simple method for the synthesis of poly(ethylene glycol) (PEG)-based uniform magnetic hydrogels that exploits the high ultraviolet absorption of a photoinitiator. Additionally, we investigated this effect on shape deformation and structural uniformity of the synthesized magnetic hydrogels. Two different photoinitiators, Darocur 1173 and lithium phenyl (2,4,6-trimethylbenzoyl) phosphinate (LAP), with significantly different UV absorption properties were evaluated based on the synthesis of magnetic hydrogels. The magnetic characteristics of the PEG-stabilized MNPs in hydrogels were investigated with a vibrating sample magnetometer. Finally, the colorimetric detection of hydrogen peroxide and glucose was conducted based on the enzyme-like property of MNPs and repeated several times to observe the catalytic activity of the magnetic hydrogels.Molecular recognition is a specific non-covalent and frequently reversible interaction between two or more systems based on synthetically predefined character of the receptor. This phenomenon has been extensively studied over past few decades, being of particular interest to researchers due to its widespread occurrence in biological systems. In fact, a straightforward inspiration by biological systems present in living matter and based on, e.g., hydrogen bonding is easily noticeable in construction of molecular probes. Selleckchem SLF1081851 A separate aspect also incorporated into the molecular recognition relies on the direct interaction between host and guest with a covalent bonding. To date, various artificial systems exhibiting molecular recognition and based on both types of interactions have been reported. Owing to their rich optoelectronic properties, chromophores constitute a broad and powerful class of receptors for a diverse range of substrates. This review focuses on BODIPY and porphyrin chromophores as probes for molecular recognition and chiral discrimination of amino acids and their derivatives.Spirolides belong to a group of marine phycotoxins produced by the marine planktonic dinophyte Alexandrium ostenfeldii. Composed of an imine moiety and a spiroketal ring system within a macrocylcle, spirolides are highly diverse with toxin types that vary among different strains. This study aims to characterize the spirolides from clonal A. ostenfeldii strains collected from the Netherlands, Greenland and Norway by mass spectral techniques. The structural characterization of unknown spirolides as inferred from high-resolution mass spectrometry (HR-MS) and collision induced dissociation (CID) spectra revealed the presence of nine novel spirolides that have the pseudo-molecular ions m/z 670 (1), m/z 666 (2), m/z 696 (3), m/z 678 (4), m/z 694 (5), m/z 708 (6), m/z 720 (7), m/z 722 (8) and m/z 738 (9). Of the nine new spirolides proposed in this study, compound 1 was suggested to have a truncated side chain in lieu of the commonly observed butenolide ring in spirolides. Moreover, there is indication that compound 5 might belong to new spirolide subclasses with a trispiroketal ring configuration having a 656 trispiroketal ring system.