Archive | December 2011

Thoughts about the main new ideas for applications

The general thought is to create educational apps, possibly for children aged 8-12.

I examined three main concepts: air pollution (creation and actions to limit it), the solar system (comets, the planets and their atmospheres) and metereology.

The concept of air pollution seemed very interesting as it would result in an application that would be both education and promote eco-sensitivity. Unfortunately, my research on the matter showed that the factors of atmospheric pollution are so varied that it is difficult to use them as elements in an interactive application (the mechanism should be relatively simple and understandable), and also that the measures to limit are mostly related to legislation..the only thing I could possibly work with is biofilters, but that would result in a very specialised app rather than one of general interest for the target group.

Metereology is also a quite complicated mechanism, but it is not impossible to use if by simplifying it. After all, the purpose of the application would be to give the user some basic knowledge and understanding of weather conditions, not make him a professional metereologist! In this case, the user would be altering parameters of the weather (e.g. temperature / humidity) and the application would begin to rain..snow..throw hail stones..etc A lot of work is required to simplify this concept to the extent that it is appropriate for such an application and the compromise in terms of accuracy will be significant. It sounds good in theory, there are however several “IF”s that should be examined.

The solar system application seems interesting and is also a safer bet. The element of interaction will mostly be limited to the navigation system (and also the plan is to have the mouse cursor being pulled by the ‘gravitational force’ of the planets). Compared to the Magnet and Hair Dryer apps I created earlier in the module, it seems like a small step back in terms of interaction and a step forward in terms of transferring information – it is a different approach.


[BOOK: “The Atmosphere: an introduction to meteorology” by Frederick K. Lutgens, Edward J. Tarbuck.


“The nature of both weather and climate is expressed in terms of the same basic elements, those qualities or properties that are measured regularly. The most important of these are: (a) the temperature of the air, (b) the humidity of the air, (c) the type and amount of cloudiness, (d) the type and amount of precipitation, (e) the pressure exerted by the air, and (f) the speed and direction of the wind. These elements constitute the variables from which weather patterns and climatic types are deciphered.”


Humidity is the general term used to describe the amount of water vapour in the air.

At higher temperatures, more moisture is required for saturation. The amount of water vapour required for saturation at various temperatures is shown in Table 4-1.

Of the methods used to express humidity, absolute and specific humidity are similar in that they both specify the amount of water vapour contained in a unit of air.

Absolute humidity is stated as the weight of water vapour in a given volume of air (usually as grams per cubic meter). As air moves from one place to another, even without a change in moisture content, changes in temperature cause changes in volume and consequently the absolute humidity, thus limiting the usefulness of this index.

Specific humidity is expressed as the weight of water vapour per weight of a chosen mass of air, including the water vapour. Since it is measured in units of weight (usually grams per kilogram), specific humidity is not affected by changes in pressure or temperature.

The most familiar and perhaps the most misunderstood term used to describe the moisture content of air is relative humidity. Stated in an admittedly oversimplified manner, relative humidity is the ration of the air’s water vapour content to its water vapour capacity at a given temperature.  From Table 4-1 we see that at 25 C the capacity of the air is 20 grams per kilogram. If on a 25 C day the air contains 10 grams per kilogram, the relative humidity is expressed as 10/20 or 50 percent. When air is saturated, the relative humidity is 100 percent.”


“The result of the condensation process may be dew, fog or clouds. For any form of condensation to occur, the air must be saturated. Saturation occurs either when the air is cooled below the dew point, which most commonly happens, or when water vapour is added to the air. Second, there must generally be a surface on which the water vapour may condense. When dew occurs, objects at or near the ground serve this purpose. When condensation occurs in the air above the ground, tiny bits of particulate matter known as condensation nuclei serve as surfaces for the condensation of water vapour.


“In an actual situation the stability of the air is determined by examining the temperature of the atmosphere at various heights. Recall that this measure is called the lapse rate. You must not confuse the lapse rate, which is the temperature of the atmosphere as determined from observations made by balloons and air planes, with adiabatic temperature changes.  The latter measure indicates the change in temperature a parcel of air would experience as it moved vertically through the surface.”

“Stated quantitatively, absolute stability prevails when the lapse rate is less than the wet adiabatic rate. At the other extreme, air is said to exhibit absolute instability when the lapse rate is greater than the dry adiabatic rate. Another situation existing in the atmosphere is called conditional instability. This occurs when moist air has a lapse rate between the dry and wet adiabatic rates (between o.5 C and 1 C per 100 meters).”

“Since stable air resists upward movement, we might conclude that clouds would not form when stable conditions prevail in the atmosphere. Although this seems reasonable, processes do exist that force air aloft. When stable air is forced aloft, the clouds that form are widespread and have little vertical thickness in comparison to their horizontal dimension, and precipitation, if any, is light. By contrast, clouds associated with unstable air towering and are usually accompanied by heavy precipitation.”

“Any factor that causes the air near the surface to become warmed in relation to the air aloft increases instability. The opposite is also true; any factor that causes the surface air to be chilled results in the air becoming more stable.”

“Instability is increased by:

1. intense solar heating that warms the air from below

2. the heating of an air mass from below as it traverses a warm surface

3. forceful lifting of air, such as over an elevated land surface

4. upward movement of air associated with general convergence

5. radiation cooling from cloud tops

Stability is enhanced by:

1. radiation cooling of the earth’s surface after sunset

2. the cooling of an air mass from below as it traverses a cold surface

3. subsidence of an air column”


Sleet is a wintertime phenomenon and refers to the fall of small, clear to translucent particles of ice. In order for sleet to be produced, a layer of air with temperatures above freezing point must overlie s subfreezing layer near the ground.

On some occasions, when the vertical distribution of temperatures is similar to that associated with the formation of sleet, freezing rain or glaze results instead. In such situations, the subfreezing air near the ground is not thick enough to allow the raindrops to freeze.

Hail is precipitation in the form of hard rounded pellets or irregular lumps of ice. Hail is produced only in cumulonimbus clouds where updrafts are strong and where there is an abundant  supply of supercooled water.”


“Phycically, there is basically no difference between a fog and a cloud. The essential difference is the method and place of formation. While clouds occur when air rises and cools adiabatically, fogs (with the exception of upslope fogs) are the consequence of radiation cooling or the movement of air over a cold surface. In other circumstances, fogs are formed when enough water vapour is added to the air to bring about saturation (evaporation fogs)

Radiation fog, as the name implies, results from radiation cooling of the ground and adjacent air. Most common in the fall and winter, it is a nigh-time phenomenon that requires clear skies and a fairly high relative humidity.

Evaporation fogs: When cools air moves over warm water, enough moisture may evaporate from the water to produce saturation.”


“Fronts are defined are boundary surfaces separating air masses of different densities, one warmer and often higher in moisture content than the other. “


“Although hurricanes and tornadoes are, in fact, cyclones, the vast majority of cyclones are not hurricanes and tornadoes. The term cyclone simply refers to the circulation around any low-pressure center, no matter how large or intense it is.”


“Cyclones form along fronts and proceed through a somewhat predictable life cycle.”


“Any factor that destabilizes the air aids in generating a thunderstorm. Since many processes do affect the stability of the air, it should come as no surprise that thunderstorms can be triggered in a number of ways. For convenience of discussion, we will divide thunderstorms into three types: (1) isolated thunderstorms produced within tropical air masses, (2) thunderstorms produced by forceful lifting, either frontal or orographic, and (3) thunderstorms produced along squall lines”.


“Tornadoes are local storms of short duration that may be ranked high among nature’s most destructive forces. The lack of forewarning, the incredible fury of its winds, and the near total destruction of the stricken area have led many to liken its passage to a bombing raid during war.

Tornadoes, sometimes called twisters or cyclones, are intense centres of low pressure having a whirlpool-like structure of winds rotating around a central cavity where centrifugal force produces a partial vacuum.

Tornadoes are most often spawned along the cold front of a middle-latitude cyclone, in conjunction with cumulonimbus clouds and severe thunderstorms.”


“The whirling tropical cyclones that on occasion have wind speeds reaching 320 kilometres per hour are known in the United States as hurricane – the greatest storms on Earth.  These awesome storms form in all tropical waters (except those of the South Atlantic) between the latitudes of 5 degrees and 20 degrees (Figure 10-14).

A hurricane can be described as a heat engine that is fuelled by the energy liberated during the condensation of water vapour (latent heat).”

Air Pollution

[BOOK: “”The Big Smoke” by Peter Brimblecombe ]

(I have a small confession to make. This particular book, I chose it primarily because it just drew my attention. But I also thought it would be a nice introduction to the topic of air pollution. It’s about the condition of the coal burning London of the past.)

“London had gained its reputation as a foggy city from the German travellers of the late seventeenth century, and at first the visitors were disappointed when a fog restricted their view of the capital, but by the nineteenth century many were even more disappointed if they were not confronted by ‘London’s Particular’.”

“Gloom covered the city in the winter months. Even the meteorologists were willing to enter the word ‘gloom’ in their diaries with increasing frequency during the course of the nineteenth century. The psychological and meteorological gloom were no doubt interconnected as there are endless descriptions of the dismal conditions that prevailed in the early part of the London winter.”

“There was increased mortality from disease during times of fog.”

” E. F. Benson’s Description:

A sudden draught apparently had swept across the sky, and where before the thick black curtain had been opaquely stretched, there came sudden rents and illuminations. Swirls of orange-coloured vapour were momentarily mixed with the black, as if the celestial artist was trying the effects of some mixing of colours on his sky palate, and through these gigantic rents there suddenly appeared, like the spars of wrecked vessels, the chimneys of the houses opposite. Then the rents would be patched up again, and the dark chocolate-coloured pall swallowed up the momentary glimpse. But the commotion among the battling vapours grew ever more intense: blackness returned to one quarter, but in another all shades from deepest orange to the pale gray of dawn succeeded one another.”

[BOOK: “”Air Pollution” by Virginia Brodine ]

Hazard: High Air Pollution Potential (HAPP)

[p.70] “While the effect of human activities on the global scale is a controversial question, there is general agreement that these activities are now having an effect on the climate of cities. The thermal pollution of the atmosphere appears small when averaged for the whole globe or for the continents. In the areas where it is already concentrated, it looks much larger and the point when its effects could become severe seems much closer. In some places, man’s activities already rival the sun in producing heat near the surface. In the summer, the amount of heat produced by combustion alone in Manhattan is one-sixth that of the solar energy reaching the ground and in winter it is two and a half times the solar energy at the surface.

..Higher temperatures in cities are the result of surface changes and gaseous and particulate pollution, as well as combustion.

..Thermal radiation emitted at the surface is re-radiated downward by the pollution layer, warming the air over the city. Unlike the self-correcting effect of natural thermal distribution, this warming of the air has a elf-perpetuating tendency – it increases the stability of the atmosphere and thereby decreases the dispersion of pollutants. However, the warming effect of the pollution layer is partially offset by its cooling effect in reflecting and scattering the incoming solar radiation.”


[p.84] Vegetation acts as a sink for some of the gaseous pollutants. Plants remove hydrogen fluoride, sulfur dioxide, and some components of photochemical smog from the air… However, these other gases are not part of the plant’s natural chemistry and can damage or even kill it.
Chemical fallout: Sulfur /Nitrogen /Lead / Cadmium / Poisons

Radioactive fallout.


Legislation and advanced techniques regarding waste, fossil-fuel burning and pollution from the automobile.

[BOOK: “Biofiltration for air pollution control” by Joseph S. Devinny, Marc A. Deschusses and Todd S. Webster ]



There are two forms of applicable air emissions control. Source control involves the reduction of emissions through raw product substitution, reduction or recycling. However, these reduction mechanisms may reduce the quality of the product or may increase costs. Secondary control involves treatment of the waste gas after it has been produced.


Waste gas contaminants that are concentrated and have a high boiling point may be partially recovered by simultaneous cooling and compressing of the gaseous vapours.  If the waste gas is a mixed pollutant system, recycling will be virtually impossible, and incineration of the condensed liquid may be required.


Thermal and catalytic incineration are widely used and effective treatment processes for waste gases. Thermal incineration involves the combustion of pollutants at temperatures of 700 to 1400 C. Catalytic incineration allows process temperatures between 300 and 700 C with catalysts such as platinum, palladium and rubidium. Incineration is the most widely used secondary technique, but costs are high for low-concentration pollutant vapours because of the need for large amounts of fuel. In general, the technology is more suitable for concentrated streams with moderate flow rates.


Adsorption generally occurs on a fixed of fluidized bed of material such as activated carbon or zeolite and is most efficient for treatment of low concentration vapours.


Absorption removes the waste gas contaminant with a scrubbing solution. The gas enters a large contactor where the gaseous pollutants are transferred to a liquid phase. Water is the most frequently used scrubbing solution.

Membrane systems

Membrane systems can be used to transfer VOCs from an air stream to a water phase. In a membrane separation system, compression and condensation of the emission stream is followed by membrane separation.

Biological treatment

Gas-phase biological reactors utilize microbial metabolic reactions to treat contaminated air. Biological treatment is effective and economical for low concentrations of contaminant in large quantities of air.

Though a number of different configurations exist, the major air-phase biological reactors are biofilters, biotrickling filters and bioscrubbers.

[BOOK: “”Air Pollution- An introduction” by Jeremy Colls ]

Despite the book claiming that it is an introduction to air pollution, it proved to be very technical and did not offer me with things that could be of use in an app like the ones I have in mind. I did however find something that I thought was interesting visually:

thoughts about Danielle’s project

At some point I started thinking about Danielle’s project idea (“VJ Experience”) and I realised that this could be combined very well with my work with interactive applications which track the mouse pointer – except in this case the “mouse” is the person itself.

Some consoles which are already popular are able to track a person moving in front of them (this was displayed last year, at the TEDx Exhibition, by the guest from Sky) and this can be used to add interaction. In the case of Danielle’s project, the person would be dancing, the equipment would track this motion and the screen behind him/her would react to this visually (e.g.  a spotlight following the person, and Danielle’s visuals moving around the figure of the person on screen).

Some research will be needed to see which consoles have this ability and if they support Flash.

I can discuss this with Danielle after the holidays. It could turn out to be something interesting, and after all the module is called “Creative Interaction”..

Idea for app: solar system

When I researched comets I found interesting things to use visually. The same happened when I studied about the planets and their atmospheres. All these could be combined in an application about the solar system. The interactive element would be the navigation between the objects. The application does not to be perfectly accurately in terms of the visual representation of the information (e.g. in a photographic way). Since the application will be an educational application for kids, some elements may be exaggerated to add visual interest and a warmer or more illustrated feel may be adopted, while keeping the basic information itself intact.

The main screen of the application would be the solar system. (If possible using flash) the planets will have a “gravitational field” which will be moving the mouse cursor towards them..  At some point a passing comet could appear. At the suggested distance from the sun it would suddenly acquire it’s “coma” (the gases leaving the nucleus). The nucleus will be rotating. There could be lightness flashes.

When the user clicks on one of the planets (or it’s gravitational field absorbs the mouse cursor!), he will be taken to the “planet” itself. If this was Mars for instance, one of the visual elements would be the ice clouds (even though in reality these are made of tiny ice particles, in the application some illustrative elements/contours of compact ice could be used, adding a slight surreal touch..). Information will also be provided in written form (for instance by hovering over items).


planets (and their atmospheres)

The book focuses on three planets: Venus, Mars and Jupiter. It provided me with information about the atmospheres and climate conditions of these planets, which included some unexpected surprises which could be used visually.. The main findings are presented below.


Has very little water vapour. Rotates slowly on its axis, in opposite direction to its rotation around the sun. There are large-scale air flows in the above-cloud atmosphere. The clouds are composed of acid (sulphuric acid).

The length of one year is 224,7 days. Its radius is 6053 km. The height of visible clouds is 57km. The average surface temperature is 700 (+- 100) K. The atmospheric pressure is 65 (+25 -15 ) atm. The surface is heavily cratered and there are visible rocks. The are signs of intensive wind erosion.

Composition of lower atmosphere: 93-100% CO2, 0-7% Ar and N2, <0.1-2% water vapour.

Composition of atmosphere over the clouds: Small amounts of water vapour (0.5-40 ppm), sulphuric acid (~10 ppm), CO (50ppm), HCl (0.4 ppm), HF (0.01 ppm), o2 (<1 ppm), He (10 ppm).

The upper atmosphere rotates quickly, in the direction contrary to that of the planet’s rotation.


Distance from the sun: 228. 10^6 km. The year lasts 687 Earth days. Its orbit around the sun is elliptical.

The atmosphere is composed of Co2 by 96% , 2,5% N, 1,5% Ar-40. It is very moist. There are frequent dust storms, sometimes covering the whole atmosphere. There isn’t a global ozone layer. There are ice clouds (!).

The surface of Mars is heavily impacted by meteors. There exist huge mountains and deep canyons. The mean surface atmospheric pressure is close to 6 mbar, that is, very near the triple point of water substance. Some ice exists on the surface (in some areas). The temperature ranges from 286K to 180K, depending on area-graphic coordinates and time.

Mars is surrounded by a halo of hydrogen.   


Conditions are characteristic of both a star (predominant hydrogen composition of the atmosphere; the presence of the internal heat source; the large-scale convection) and a planet. Jupiter with its 16 satellites represents almost another solar system.

There is high stability of individual elements in its atmosphere. The Great Red Spot (a huge-scale anti-cyclonic storm) has existed for more than 180 years. There are powerful storms, always accompanied by lightning strikes.

Jupiter is a mass of liquid hyrdrogen and is probably deprived of solid crust (apparently the planet has a comparatively small solid kernel surrounded by a powerful atmosphere; at any rate, down to 10^4 km and a pressure of 10^6 bar, Jupiter should be liquid).

The radius of this giant planet constitutes 71600 (+-100) km i.e. 318 times that of the Earth. Its mass exceeds 2,5 times the total mass of all planets and is 300 times greater than the mass of the Earth. However, its density is very low because it consists mainly of such volatiles as hydrogen, helium, carbon and nitrogen.

A rotation around its axis takes 10 hours. The temperature of its atmosphere is about 170K at a level of 0,001 mbar.

Main structure of atmosphere:

– the outer atmosphere is a gas layer above the clouds, completely covering the planet

– a condensation zone or a cloud layer, is an aerosol cloud, the upper part which consists of solid particles (crystals) of the substance with a relatively high temperature of melting, the lower part of the cloud may have a water-drop microstructure;

-a sub-cloud atmosphere is a high-pressure region iwth very dense gas.



Some notes I made from the book.

Nucleus: A solid but fragile, ice-dust mixture of diameter 0.1 to 10 km. A “dirty snowball” which is exposed to cosmic rays, solar wind ions and and surface photoelectron currents.

The “coma” is formed when it passes with r~3 AU of the Sun. A tail may or may not follow.

The nucleus rotates!

Occasional “halos”.

Sometimes they have outbursts (brightness flares).

A diagram of the nucleus:

Comets were probably formed at the same time as the solar system.

They often split (!), usually at a great distance from the sun.

The most widely accepted place of origin for comets is the Oort Cloud, which is located in a vast area surrounding the sun and extending to 1/5 the distance to alpha Centauri, the nearest start to the sun.

Evaluating the situation:

There are  some really interesting things to use visually (nucleus rotating, the comet splitting into two, acquiring the “coma” when approaching the sun, brightness flares..) and the comet itself has some visual interest. How could it be turned into an interactive application though?