. SUPER HYDROPHOBICITY Soumya Ranjan Sahoo (711CH1025) NIT, Rourkela Abstract:
Superhydrophobicity as a sensation has turned into an increasing focus of research and technological movement, where its key viewpoints span surface chemistry, chemical physics, and cellular biology. Hydrophobic particles have a tendency to be non-polar and, accordingly, incline toward other neutral molecule and non-polar solvents. Hydrophobic atoms in water frequently bunch together, shaping micelles. Water on hydrophobic surfaces will display a high contact point. Superhydrophobic surfaces are exceptionally hydrophobic, i.e., greatly hard to wet. The contact angle of a water droplet surpasses 150° and the contact angle hysteresis is under 10°. This is also referred to as the Lotus impact, after the superhydrophobic leaves of the lotus plant.Rough and microstructured surfaces characteristically build hydrophobicity of hydrophobic surfaces through two altogether
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Modeling of Contact Angle for a Liquid in Contact with a Rough Surface
When a solid is in contact with liquid, the molecular attraction will reduce the energy of the system below that for the two separated surfaces. This is expressed by the Dupré equation Figure-1
2.1 Wenzel Model:
The Wenzel model (Robert N. Wenzel 1936) describes the homogeneous wetting regime, as seen in Figure 2, and is defined by the following equation for the contact angle on a rough surface.
where is the apparent contact angle which corresponds to the stable equilibrium state (i.e. minimum free energy state for the system). The roughness ratio, r, is a measure of how surface roughness affects a homogeneous surface. The roughness ratio is defined as the ratio of true area of the solid surface to the apparent area. Figure -2 : Wenzel
Drippy Drop started off in a cloud over Mount Everest, where the first step of the water cycle would occur, precipitation. Drippy Drop fell in the form of snow on the peak of Mount Everest. Seven months passed when the snow started to turn mushy. Some snow melted and created a run-off. So Drippy Drop fell to the very bottom and soaked into the fresh soil at the bottom of Mount Everest.
Both angles are measured with respect to the normal to the [surface]”
The golden ratio is a unique number approximately equalling 1.6180339887. The Greek letter ‘phi’, Φ, represents the golden ratio which can be found in many places including the human body, architecture, nature and art. The golden ratio has many different names including the: divine section, medial section, golden mean, divine proportion and golden proportion. If a line where to be split into two unequal sections and the whole length of the line divided by the longer section of the line equals the longer section of the line divided by the shorter section of the line, then this is called ‘phi’. The formula for finding if a line uses phi is: (a+b) ÷a= a÷b.
Essayist and Novelist David Foster Wallace, in his speech, “This is Water,” defends the true purpose of a liberal arts education, and emphasizes the necessity of thinking the right way in life. Wallace attempts to create a humble, personal tone through the use of informal diction, ethical appeals, and personal encounters in order to connect with his audience and shift them to see that they are not alone in this struggle, and they must prevail in order to truly be “living.” Wallace’s argument is successful due to the implementations of this tone, ethical appeals, and repetition of purposeful phrases. Wallace’s informal or low diction is shown through the use of words such as, “finger wagging,” “bullshit,” and, “god-damn people.” The effect of these words is the creation of a laid back, personable tone that ensures the audience does not feel like Wallace is “preaching” to them or giving them “moral advice.”
When the fate of the United States is in the hand of a terrorist, how else will the military gather intelligence? The use of waterboarding as a form of interrogation gathers intelligence unlike any other form of interrogation, but some Americans view this method as torture; however, this method is very effective. Should the United States government reinstate waterboarding as a form of interrogation? The United States government should reinstate the use of waterboarding as a form of interrogation in the United States. Waterboarding originated in the 14th century and has kept the same concept.
Aspect ratio is a mathematical expression of the ratio of the width of a screen size or film format to its height. In expressing an aspect ratio, the width, which is typically always the greater length, is given first, followed by the height. The screen aspect ratio of standard television is 1.33 to 1, which simply means that standard definition television screens and programming formatted to run on this aspect ratio are 1.33 times as wide as they are high. This is also more commonly expressed as a 4:3 aspect ratio. To make the math simple, this would simply mean that if a television screen were 30 inches high it would be 40 inches wide given its aspect ratio of 4:3.
Von Mises [3] states that “the forces due to viscosity appear as products of μ and expressions that have the dimensions area times (velocity / length)”. By further investigation, the mathematical analysis of these principles leads to a system of partial derivatives known as the Navier-Stokes equations. These equations are used to describe fluid flow and can be used to solve specific dynamic fluid flow cases. These include; velocities, pressure, temperature, density and can also be used to solve viscous problems of a dynamic fluid flow problems. These partial derivative equations relating to the specific variables are extremely complex and time-consuming to
Like fractals, details within details. They form a natural hierarchy. You cannot directly see hierarchies, you can only see the objects that make them up. But the hierarchies are there and they are very important. From “Half Inch Trim” (240) we know that the smallest scale we need be concerned with is about a half-inch, which is also about the same scale as decorative trim and handmade details.
The Golden Ratio is a number. A number that results when you split a line into two parts. You should be able to divide the longer part by the smaller part so that it is equal to the whole length divided by the smaller part. It is also known as phi, a letter of the Greek alphabet.
##contact-us-form## ##beforeandafter## Foundation Waterproofing When your property has been affected by strong rain, flooding isn’t far behind. You could end up with secondary damage, such as having mold and mildew in your basement or crawl space. While they may look harmless, they have the ability to cause respiratory problems if not dealt with immediately.
It calculates the distance of an object (oi) from the mean of the i-th dimension (Ei). If the chi-squared statistic is large, then it can be said that the object, oi, is an
Water has Been Discovered on Mars In 1969 man landed on the moon. In 1972 the land rover landed on the red planet. Now in 2015 the announcement of liquid water on Mars has been discovered. We’ve looked through massive telescopes, put them is space, all to answer the question; are we alone?
But it has an extraordinary ability; when it is scared, it produces a defensive slug slime that allows it to stick itself onto wet surfaces. As you probably know, when we are scared, we enter into fight-or-flight mode. As for the slug, when it gets frightened by, say, a bird, it secretes a sticky mucus from its skin. The mucus is so adhesive that it might prevent the bird from pulling it off a leaf— just like how a persistent chewing gum would refuse to leave the bottom of your shoe. This mucus inspired the material scientists from Harvard's Wyss Institute for Biologically Inspired Engineering to design the new form of
The fog forms drops in the air rather than on the surface of