It ends up creating air pockets underneath, which in turns provides liquid repellency.
|
|
PFAS are characterized by fluorine-carbon bonds, among other traits, which makes those chemicals especially useful, giving them traits including outstanding durability, heat resistance, and water- and oil-repellency.
|
|
The violent color scheme of Matt Saunders's set (banana, fuchsia, aqua) seems to be duking it out with Yi Zhao's lighting (which includes stroke-triggering strobe effects) for a prize in repellency.
|
|
Silicone fluids added to polishes or surface treatments deliver gloss, water repellency and improve rubout.
|
|
These have been underpinned by the investigation of fundamental mechanisms and scale-up. Examples include: antibacterial, fog harvesting, catalysis, non-fouling, optochiral switches, filtration, biochips, super-repellency, and nano-actuation.
|
|
Certain types of fabrics need to be re-treated to maintain water-repellency, as fluoropolymers decompose over time when exposed to water and chemicals. Washing the garment with harsh detergents usually accelerates DWR loss; in addition, soaps often leave a residue which attracts water and dirt. On the other hand, rain water or salt water affects DWRs less significantly. Affected garments can be treated with a 'spray-on' or 'wash-in' treatment to improve water-repellency.
|
|
Video tracking of a stable fly, demonstrating repellency of lemongrass oil Beekeepers sometimes use lemon grass oil in swarm traps to attract swarms. Lemon grass oil has also been tested for its ability to repel the pestilent stable fly, which bite domestic animals.
|
|
This system regenerates. This biochemical property is responsible for the functioning of the water repellency of the surface. The hydrophobicity of a surface can be measured by its contact angle. The higher the contact angle the higher the hydrophobicity of a surface.
|
|
Nepetalactone is a mosquito and fly repellent.Junwei J. Zhu, Christopher A. Dunlap, Robert W. Behle, Dennis R. Berkebile, Brian Wienhold. (2010). Repellency of a wax-based catnip- oil formulation against stable flies. Journal of Agricultural and Food Chemistry, 58 (23): 12320–12326 (8 Nov 2010, ).
|
|
Performance of surgical masks is evaluated based on such parameters as filtration (mask capture of exhaled aerosols), exposure (transfer of aerosols from outside), mask airflow resistance (pressure difference during breathing, ΔP, also known as breathability), liquid penetration resistance, air and water vapor permeability, water repellency (for outer and inner surfaces). Filtration and exposure is typically measured in bacterial filtration efficiency (BFE) and particulate filtration efficiency (PFE).
|
|
It causes the predator's feathers to mat, leading to the loss of flying ability and the loss of water repellency. This is especially dangerous for aquatic birds because their water repellent feathers protect them from hypothermia when diving for food. European roller chicks vomit a bright orange, foul smelling liquid when they sense danger. This repels prospective predators and may alert their parents to danger: they respond by delaying their return.
|
|
It is widely agreed that the water repellency of biological objects is due to the Cassie-Baxter equation. If water has a contact angle between 0< \theta <90^\circ, then the surface is classed as hydrophilic, whereas a surface producing a contact angle between 90^ \circ< \theta <180^ \circ is hydrophobic. In the special cases where the Contact angle is 150^ \circ< \theta, then it is known as superhydrophobic.
|
|
"Protection against Mosquitoes, Ticks, & Other Arthropods", U.S. Centers for Disease Control In an earlier report, the CDC found oil of lemon eucalyptus to be more effective than other plant-based treatments, with a similar effectiveness to low concentrations of DEET. However, a 2006 published study found in both cage and field studies that a product containing 40% oil of lemon eucalyptus was just as effective as products containing high concentrations of DEET.Carroll SP, Loye J, 2006, Journal of the American Mosquito Control Association 22(3):507-514, 510 Research has also found that neem oil is mosquito repellent for up to 12 hours. Citronella oil's mosquito repellency has also been verified by research,Jeong-Kyu KIM, Chang-Soo KANG, Jong-Kwon LEE, Young-Ran KIM, Hye-Yun HAN, Hwa Kyung YUN, Evaluation of Repellency Effect of Two Natural Aroma Mosquito Repellent Compounds, Citronella and Citronellal, Entomological Research 35 (2), 117–120, 2005 including effectiveness in repelling Aedes aegypti,Ibrahim Jantan, and Zaridah Mohd.
|
|
Hydrophobic soil – soil that is hydrophyllic – causes water to collect on the soil surface rather than infiltrate into the ground. Wild fires generally cause soils to be hydrophobic temporarily, which increases water repellency, surface runoff and erosion in post-burn sites. Soil dispersion due to sodification causes similar problems. Hydrophobic soils are created when hydrocarbon residue is created after organic material is burnt and soaks into empty pore spaces in the soils, making it impervious to water.
|
|
In the mind of Houtkamp, tattoos are connected with emotions pertaining to attraction, repellency, life, death, fear, and power. These motifs are made with vintage iconographs from old tattoo imagery and historical aesthetics. The popularity of Houtkamp’s skilled tattoos has captured the attention of multiple tattoo conventions, magazines, and art culture interviewers. Some of her more notable features are in articles of the publications of ITA and Penthouse, as well as Juxtapoz Art and Culture Magazine.
|
|
This oil can be deadly to birds, as it can cause matting of the feathers leading to the loss of flight or water repellency. Against threatening mammals (including humans) it is not outright dangerous, but due to its extremely offensive smell it is usually highly repulsive and liable to spoil a predator's hunting success for quite some time. The smell of the hydrophobic oil cannot be removed with water, and can persist (e.g. on clothing) for months or even years.
|
|
Affected birds accumulated a proteinaceous material on their feathers, causing a loss in the natural water repellency. However no toxins, such as domoic acid, saxitoxin or brevetoxin was detected in the water. It was the first documented case of its tide causing harm to birds. In 2009 a huge foam event blamed on Akashiwo sanguinea killed vast quantities of sea birds from the northern Oregon coast to the tip of the Olympic Peninsula in Washington state. The species’ blooms have also been linked to coral bleaching.
|
|
Neem-based formulations of pesticides reduced the amount of food ingest by S. eridania larvae. The growth that is disrupted by neem is determined not only by feeding inhibition but also by digestibility, as the S. eridania larvae showed reduced efficiency in converting ingested food. These setbacks in growth and food ingestion and digestion extend the development time of larvae. Neem-based pesticides are exceptional in having broad range of bioactivity against herbivores that include toxicity, growth regulation, repellency, feeding deterrency, and disruption of metamorphosis.
|
|
Video tracking of a stable fly, demonstrating repellency of citronella oil Citronella oil is popular as a natural insect repellent. Its mosquito repellent qualities have been verified by research, including effectiveness in repelling Aedes aegypti (dengue fever mosquito). To be continually effective, most citronella repellent formulas need to be reapplied to the skin every 30–60 minutes."Test: Mosquito Repellents, The Verdict" Choice, The Australian Consumers Association Citronella candles (which burn citronella oil) are no more effective than other candles at repelling insects, and experts do not recommend it as a useful method.
|
|
In some cases heat treatment can reactivate the factory applied repellent finish and aid in the repelling of water, and other liquids such as oils. On the other hand, some DWR products do not require heat treatment to be activated, and sometimes DWR treatments can be revitalized simply by washing the fabric with a suitable cleaner. Top part of the fabric has been ironed after re treatment washing and this heat application has revitalized the repellency of water. Bottom part of the fabric has not been ironed after re treatment washing and the water is still wetting out the fabric.
|
|
In 1970 waxless Nordic skis were made with fishscale bases. Klister, a sticky material, which provides grip on snow of all temperatures that has become coarse-grained as a result of multiple freeze- thaw cycles or wind packing, was invented and patented in 1913 by Peter Østbye. Recent advancements in wax have been the use of surfactants, introduced in 1974 by Hertel Wax, and fluorocarbons, introduced in 1986, to increase water and dirt repellency and increase glide. Many companies, including Swix, Toko, Holmenkol, Briko, and Maplus are dedicated to ski wax production and have developed a range of products to cover various conditions.
|
|
In England tansy is placed on window sills to repel flies; sprigs are placed in bed linen to drive away pests, and it has been used as an ant repellent. In the 1940s, distilled tansy oil mixed with fleabane, pennyroyal and diluted alcohol was a well-known mosquito repellent; collectors were paid five cents a pound for tansy in full bloom. Research has found that tansy extracts do indeed repel mosquitoes, but not as effectively as products containing DEET. In 2008, researchers in Sweden investigated the use of tansy to repel ticks, showing a 64–72 percent repellency for each oil constituent.
|
|
At high concentrations, these recalcitrant constituents can increase soil-water repellency, affect plant growth, reduce the ability of the soil to support a diverse community of organisms, and render the land farm no longer usable without treatment or amendment.Callahan et al. 2002 Recent studies have supported the idea that field-scale additions of earthworms with selected organic amendments may hasten the long-term recovery of conventionally treated petroleum contaminated soil. The burrowing and feeding activities of earthworms create space and allow food resources to become available to other soil organisms that would be unable to survive otherwise.
|
|
Essential oil repellents can be short-lived in their effectiveness, since essential oils can evaporate completely. A test of various insect repellents by an independent consumer organization found that repellents containing DEET or picaridin are more effective than repellents with "natural" active ingredients. All the synthetics gave almost 100% repellency for the first 2 hours, where the natural repellent products were most effective for the first 30 to 60 minutes, and required reapplication to be effective over several hours."Test: Mosquito Repellents, The Verdict" Choice, The Australian Consumers Association Although highly toxic to cats, permethrin is recommended as protection against mosquitoes for clothing, gear, or bed nets.
|
|
The use of insecticide treated mosquito nets (ITNs) are at the forefront of preventing mosquito bites that cause malaria. The prevalence of ITNs in sub-Saharan Africa has grown from 3% of households to 50% of households from 2000 to 2010 with over 254 million insecticide treated nets distributed throughout sub-Saharan Africa for use against the mosquito vectors Anopheles gambiae and Anopheles funestus which carry malaria. Because the Anopheles gambiae feeds indoors (endophagic) and rests indoors after feeding (endophilic), insecticide treated nets (ITNs) interrupt the mosquito's feeding pattern. The ITNs continue to offer protection, even after there are holes in the nets, because of their excito- repellency properties which reduce the number of mosquitoes that enter the home.
|
|
Ground or crushed dried chili pods may be used in birdseed to deter rodents, taking advantage of the insensitivity of birds to capsaicin. The Elephant Pepper Development Trust claims that using chili peppers as a barrier crop can be a sustainable means for rural African farmers to deter elephants from eating their crops. An article published in the Journal of Environmental Science and Health Part B in 2006 states that "Although hot chili pepper extract is commonly used as a component of household and garden insect-repellent formulas, it is not clear that the capsaicinoid elements of the extract are responsible for its repellency." The first pesticide product using solely capsaicin as the active ingredient was registered with the U.S. Department of Agriculture in 1962.
|
|
One study concluded that "DDT is still a viable insecticide in indoor residual spraying owing to its effectivity in well supervised spray operation and high excito-repellency factor." Studies of malaria-vector mosquitoes in KwaZulu- Natal Province, South Africa found susceptibility to 4% DDT (WHO's susceptibility standard), in 63% of the samples, compared to the average of 87% in the same species caught in the open. The authors concluded that "Finding DDT resistance in the vector An. arabiensis, close to the area where we previously reported pyrethroid-resistance in the vector An. funestus Giles, indicates an urgent need to develop a strategy of insecticide resistance management for the malaria control programmes of southern Africa." DDT can still be effective against resistant mosquitoes and the avoidance of DDT- sprayed walls by mosquitoes is an additional benefit of the chemical.
|
|