Where did the water in the Oceans come from?
Outgassing (H2O, CO2) of the Earth from volcanoes, early in its history, but continuing today Sedimentary rocks as old as 3.8 billion years!A much smaller amount from comets that pass by.Weak electrical attraction makes for “sticky” molecules This explains its unique properties: heat capacity surface tension dissolving power
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: "Deleted in Malignant Brain Tumors 1 (DMBT1) is present in hyaline membranes and modulates surface tension of surfactant...
Surface effects in film coating
Michael E.Aulton SUMMARY This chapter will explain the significance of the stages of impingement, wetting, spreading and penetration of atomized droplets at the surface of tablet or multiparticulate cores. It will explain some of the fundamental aspects of solid-liquid interfaces which are important to the process of film coating. This chapter will emphasize the importance of controlling the ‘wetting power’ of the spray and the ‘wettability’ of the substrate, and will explain how this can be achieved by changes in formulation and process parameters.
The tension structures discussed in this book are predominantly roofing forms created from pre-stressed cable nets, cable trusses, and continuous membranes (fabric structures). A unique feature in their design is form-finding an interactive process of defining the shape of a structure under tension. The book discusses the role of stable minimal surfaces (minimum energy forms occurring in natural objects, such as soap films) in finding optimal shapes of membrane and cable structures.
Gas–liquid multiphase flows play an essential role in the workings of Nature and
the enterprises of mankind. Our everyday encounter with liquids is nearly always
at a free surface, such as when drinking, washing, rinsing, and cooking. Similarly,
such flows are in abundance in industrial applications: heat transfer by boiling is
the preferred mode in both conventional and nuclear power plants, and bubbledriven
circulation systems are used in metal processing operations such as steel
making, ladle metallurgy, and the secondary refining of aluminum and copper.
In the discussion above, high surface tension and low viscosity are required for good ﬂow-out and leveling. But high surface tension can cause cratering, and excessively low viscosity would result in sagging and poor edge coverage. To obtain an optimal coating, the balance between surface tension and viscosity is important. Figure 2.12 illustrates coating performance as a function of surface tension and melt viscosity. Coating is a fairly complex process; achieving an optimal result calls for the consideration of many factors....
Solution properties and atomization in film coating
Michael E.Aulton and Andrew M.Twitchell SUMMARY A little-considered stage of the film-coating process is the atomization of the coating solution by the spray gun. This chapter will show how formulation and process factors can cause marked changes in the characteristics of the spray, which may have important consequences for film formation and film properties.
We study random surfaces which arise as height functions of random perfect matchings (a.k.a. dimer conﬁgurations) on a weighted, bipartite, doubly periodic graph G embedded in the plane. We derive explicit formulas for the surface tension and local Gibbs measure probabilities of these models. The answers involve a certain plane algebraic curve, which is the spectral curve of the Kasteleyn operator of the graph. For example, the surface tension is the Legendre dual of the Ronkin function of the spectral curve.
There have been major breakthroughs in lung surfactant (LS) research over the
last two decades that have changed our concept of how and why the material
works well at the lung air–water interface. From the initial ideas of a surface
active material lining the alveoli to the seminal concepts of how low surface
tension is reached, the classical ideas about Comroe’s “extraordinary juice”
requires revision and re-thinking.
Physical water resource constraints make companies more susceptible to reputational risks.
Declines in water availability and quality can increase competition for clean water. In water-scarce
regions, tensions can arise between businesses and local communities, particularly in developing
countries where local populations often lack access to safe and reliable drinking water. Community
opposition to industrial water withdrawals and perceived or real inequities in use can emerge
quickly and affect businesses profoundly.
The electrospinning technique for the scaffolds designing utilizes the electrostatic force for
the production of polymeric fiber ranging from nanoscale to microscale. This process is
control by high intensity electric field between two electrodes having electric charges of
opposite polarity. One electrode is placed in the polymer solution and other is placed in
collector. Generally polymer solution is pumped as result in forming a drop of solution.
Conditions often arise in machines and mechanisms when stresses fluctuate between a upper and a lower limit. For example in figure-188.8.131.52, the fiber on the surface of a rotating shaft subjected to a bending load, undergoes both tension and compression for each revolution of the shaft.
Anaerobic bacteria are organisms that require reduced oxygen tension for growth, failing to grow on the surface of solid media in 10% CO 2 in air. (In contrast, microaerophilic bacteria can grow in an atmosphere of 10% CO2 in air or under anaerobic or aerobic conditions, although they grow best in the presence of only a small amount of atmospheric oxygen, and facultative bacteria can grow in the presence or absence of air.) This chapter describes infections caused by nonsporulating anaerobic bacteria. In general, anaerobes associated with human infections are relatively aerotolerant. ...