The presence of cocaine and its metabolites and by-products has been identified in different aquatic matrices, making crack cocaine the target of recent studies. The aim of this study was to evaluate the sublethal effects of crack on the brown mussel Perna perna. Mussels were exposed to three concentrations of crack cocaine (0.5, 5.0, and 50.0 μg L-1) for 168 h. Gills, digestive glands, and hemolymph were extracted and analyzed after three different exposure times using a suite of biomarkers (EROD, DBF, GST, GPX, LPO, DNA damage, ChE, and lysosomal membrane stability [LMS]). After 48 and 96 h of exposure, EROD, DBF, GST, GPX activities and DNA strand breaks in the gills increased significantly after 48 and 96 h of exposure. Alterations in LMS were also observed in the mussels exposed to all crack concentrations after 96 and 168 h. Our results demonstrated that crack cocaine is metabolized by CYP-like and GST activities in the gills. GPX was not able to prevent primary genetic damage, and cytotoxic effects in the hemocytes were also observed in a dose- and time-dependent response. Our study shows that the introduction of illicit drugs into coastal ecosystems must be considered a threat to marine organisms.
Aquarix Crack
Greenhouse gasses generated from the degradation of solid waste pass through landfill covers and participate in climate change. The formation of desiccation cracks in surface soil leads to direct interaction of greenhouse gasses into the atmosphere. In current study, attempts were made to reduce crack damage and water evaporation of a sandy soil amended with intrusive aquatic biomass derived carbon (water hyacinth and dry algae) also known as biochar. The results show that, the addition of water hyacinth biochar (WHB) and algae biochar (AB) reduced the evaporation rate of densely compacted soil and increases the water retention capacity of soil at 5% and 10% application rate. Furthermore, WHB produced at high temperature has more potential in reducing cracks than that produced at lower temperature. WHB showed better performance than AB at any temperature (i.e. 300 C, 400 C and 700 C) due to its highly porous structure. The current study concludes that biochars from aquatic weeds can be utilized for soil remediation (i.e., minimizing cracking and evaporation rate), which is useful in both waste management and agricultural applications.
On Sunday, the Aquatic Team of Mecklenburg (ATOM) registered the top time the season in the mixed 200 free relay. Their swim of 1:39.67 also cracked the USA Swimming 15-16 national age group benchmark of 1:41.68 and the 17-18 benchmark of 1:40.25.
A renowned sports analyst has questioned China Civil Engineering Construction Corporation (CCECC) for the substandard work at the newly built Kamuzu Institute for Sports Aquatic Centre in Lilongwe after video footage has gone viral on social media showing huge cracks and land sinking on the surface and terraces of the newly built Sports facility.
Pond Armor Crack RX works to fill in cracks in surfaces like concrete prior to the application of Pond Armor Epoxy Liner. This gray polyurethane caulk eliminates many of the problems that occur with certain substrates, such as outgassing (where bubbles can form in the finished coat). This caulk is quick and easy to apply to a wide variety of surfaces, such as wood, metal, stone, or plastic. Perfect for preparing a surface for Pond Armor Epoxy Liner in order to make a pond, stock tank, pool, fountain, waterfall, and many more!
The Crack Back Bullet utilizes the same concept as the Split Case nymph, with a colored stripe across the back of the fly to simulate the nymphal shuck just beginning to crack open before emergence. This fly takes it a step farther, through, with a more fluorescent material combined with a hot collar to add some extra appeal to the fly's appearance. The slim design also sinks like a rock, getting the fly down to the fish quickly and effectively.
QUIKRETE Advanced Polymer Concrete Crack Sealant (No. 8620-17) is a solvent and isocyanate free line of high-performance, commercial-grade material that permanently seals and waterproofs cracks in concrete with textured matte finish. Designed to deliver or exceed the performance of traditional polyurethane or silicone sealants and adhesives, the single-component QUIKRETE Concrete Crack Sealant is an environmentally-friendly alternative that meets meet ASTM C920 standards. Available in 10-ounce tubes.
Your bath is meant to be a relaxing place. A place to soak and unwind after a long day. But when you notice a crack in your tub, it is anything but relaxing. Although cracks are no major cause for concern, they should be dealt with in a timely manner in order to avoid further damage. Find out what causes bathtubs to crack and what to do about it.
There are three primary causes of cracks forming on or in your bathtub. Damage can be caused by lack of support, heavy objects, and harsh cleaners. Lack of support underneath your bathtub can be a strong contributor to the downfall of your tub, especially when it comes to fiberglass surfaces. Fiberglass is very flexible and easily bends under weight. Continuous pressure from weight combined with improper support can lead to cracks over time.
A heavy object is the second culprit. When heavy objects are dropped in a bathtub, small divots and dents begin to form. These divots eventually lead to cracks. Finally, highly abrasive cleaners, such as bleach, can weaken your tub. These harsh cleaners cause the finish and gloss of your tub to erode, leaving openings for moisture to seep into the material and cause cracks.
There are two types of cracks that can show up in your bathtub. The first is a stress crack. Stress cracks form when a heavy object is dropped on the surface of the tub. They are surface cracks and are not cause for major concern. They may begin as a small divot or dents. Stress cracks are easy to repair.
The second type of crack you may see is a hairline crack. Hairline cracks will occur after consistent use and abuse of the material. They begin as small cracks and over time can damage the integrity of your tub. Similar to stress cracks, hairline cracks are repairable. Depending on the size and number of cracks, it may be worth it to contact a professional.
Using gelatin as an analogue for sediment (on the basis of its similar mechanical properties)1,2,4 and polarized light to visualize the burrow around N. virens, we investigated whether these worms burrow by crack propagation. Gelatin is birefringent, which enables its stress to be analysed5 during burrowing.
We found that the edges of the burrow were visible and that they showed evidence of a discoidal crack, which was held open by the dorsal and ventral surfaces of the animal (Fig. 1a, b). The arc of the crack extends laterally beyond the setae and anteriorly to the tips of the antennae. Visualization of stress fields by photoelastic stress analysis (for methods, see supplementary information) reveals a force exerted dorsoventrally by eversion of the animal's pharynx against the relatively flat wall of the crack (Fig. 1c).
a, Anterior view in crosspolarized light, showing the longer axis of the discoidal crack, which is parallel to the setae, and showing the dorsal and ventral surfaces against the gelatin substrate; the shape of the burrow follows the line encircling the crack. b, Dorsal view in crosspolarized light, showing the shape of the burrow around the animal. c, Side view in circularly polarized light, showing the stress field dorsal and ventral to the worm, and the crack extending anteriorly.
According to linear elastic fracture mechanics, the stress intensifies at the crack tip, propagating it when the critical stress intensity is reached1,6. Here, the everted pharynx acts as a wedge, with the radial force intensified at the tip of the crack, which propagates, allowing the animal to move forward (Fig. 2). The crack's aspect ratio (T/W in Fig. 2) is a function of the material properties of the sediment (the critical stress intensity and Young's modulus). Expansion of a subterminal body portion has previously been considered as an anchor7; we infer instead that a terminal or subterminal lateral expansion acts as a wedge in elastic mud.
Arrows extending vertically from the crack indicate forces. The worm everts its pharynx and exerts a force normal to the direction of movement (1), which causes the crack to propagate, releasing energy (2). The worm then retracts the pharynx and moves forward into the crack (3) before repeating the cycle (4). W is the longer axis of the discoidal crack; T, the shorter.
The first segment shows a dorsal view of Nereis virens burrowing in gelatin, in which the crack is clearly visible (with polarized light). When the animal everts its pharynx, the crack propagates. The second segment shows a lateral view, with the stress field around the burrowing animal visible as light passing through crossed polarizers. (MPG 14777 kb)
Dr. Dugong: Man seeks a good time, but he is not a hedonist. He seeks love! He just doesn't know where to look. He looks under the beds of whores and in the hot stem of a crack pipe. He should look to nature! Gentle aquatic mammals have all the answers!
Gulfstream Casino, Hallandale Beach, FL: The14-ft-diameter x 14-ft-high cylindrical aquarium opened at a fabricated (bonded) seam. The acrylic panels were 3 in. thick. A seam opened, instantaneously releasing thousands of gallons of water. After the event occurred, a quick-thinking maintenance person stuffed the crack with cloth napkins saving all the aquatic life, except for one shark. This failure was the result of poor bonding of a vertical seam during manufacturing. Over time, this seam opened slightly by crazing, creating a stress concentration, which led to the catastrophic event.
Mazatlan, Mexico: A large crack formed instantaneously in a 3-in.-thick curved overhead viewing panel on Feb. 3, 2017, shortly after the aquarium had closed for the day. The 1.2-million-gallon aquarium housed 13 large sharks at the time of the failure. The crack released over three quarters of the water in the aquarium, allowing for the safe removal of the sharks. This crack initiated at a large gouge mark at the exterior of the tank. 2ff7e9595c
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