Monday, October 25, 2010

How Does Sunscreen Work?

Sunscreen combines organic and inorganic chemicals to filter the light from the sun so that less of it reaches the deeper layers of your skin. Like a screen door, some light penetrates, but not as much as if the door wasn't present. Sunblock, on the other hand, reflects or scatters the light away so that it doesn't reach the skin at all.
The reflective particles in sunblocks usually consist of zinc oxide or titanium oxide. In the past, you could tell who was using a sunblock just by looking, because the sunblock whited out the skin. Not all modern sunblocks are visible because the oxide particles are smaller, though you can still find the traditional white zinc oxide. Sunscreens usually include sunblocks as part of their active ingredients.
What Sunscreens Screen
The portion of the sunlight that is filtered or blocked is ultraviolet radiation. There are three regions of ultraviolet light.
  • UV-A penetrates deeply into the skin and can lead to cancer and premature skin aging.
  • UV-B is involved in tanning and burning of your skin.
  • UV-C is completely absorbed by the earth's atmosphere.
The organic molecules in sunscreen absorb the ultraviolet radiation and release it as heat.
  • PABA (para-aminobenzoic acid) absorbs UVB
  • Cinnamates absorb UVB
  • Benzophenones absorb UVA
  • Anthranilates absorb UVA and UVB
  • Ecamsules absorb UVA
What SPF Means
SPF stands for Sun Protection Factor. It's a number that you can use to help determine how long you can stay in the sun before getting a sunburn. Since sunburns are caused by UV-B radiation, SPF does not indicate protection from UV-A, which can cause cancer and premature aging of the skin.
Your skin has a natural SPF, partially determined by how much melanin you have, or how darkly pigmented your skin is. The SPF is a multiplication factor. If you can stay out in the sun 15 minutes before burning, using a sunscreen with an SPF of 10 would allow you to resist the burn for 10x longer or 150 minutes.
Although the SPF only applies to UV-B, the labels of most products indicate if they offer broad spectrum protection, which is some indication of whether or not they work against UV-A radiation. The particles in sunblock reflect both UV-A and UV-B

How Fireworks Work Firecrackers, Sparklers & Aerial Shell Fireworks

Fireworks have been a traditional part of New Year's celebrations since they were invented by the Chinese almost a thousand years ago. Today fireworks displays are seen on most holidays. Have you ever wondered how they work? There are different types of fireworks. Firecrackers, sparklers, and aerial shells are all examples of fireworks. Though they share some common characteristics, each type works a little differently. Firecrackers
Firecrackers are the original fireworks. In their simplest form, firecrackers consists of gunpowder wrapped in paper, with a fuse. Gunpowder consists of 75% potassium nitrate (KNO3), 15% charcoal (carbon) or sugar, and 10% sulfur. The materials will react with each other when enough heat is applied. Lighting the fuse supplies the heat to light a firecracker. The charcoal or sugar is the fuel. Potassium nitrate is the oxidizer, and sulfur moderates the reaction. Carbon (from the charcoal or sugar) plus oxygen (from the air and the potassium nitrate) forms carbon dioxide and energy. Potassium nitrate, sulfur, and carbon react to form nitrogen and carbon dioxide gases and potassium sulfide. The pressure from the expanding nitrogen and carbon dioxide explode the paper wrapper of a firecracker. The loud bang is the pop of the wrapper being blown apart.
A sparkler consists of a chemical mixture that is molded onto a rigid stick or wire. These chemicals often are mixed with water to form a slurry that can be coated on a wire (by dipping) or poured into a tube. Once the mixture dries, you have a sparkler. Aluminum, iron, steel, zinc or magnesium dust or flakes may be used to create the bright, shimmering sparks. An example of a simple sparkler recipe consists of potassium perchlorate and dextrin, mixed with water to coat a stick, then dipped in aluminum flakes. The metal flakes heat up until they are incandescent and shine brightly or, at a high enough temperature, actually burn. A variety of chemicals can be added to create colors. The fuel and oxidizer are proportioned, along with the other chemicals, so that the sparkler burns slowly rather than exploding like a firecracker. Once one end of the sparkler is ignited, it burns progressively to the other end. In theory, the end of the stick or wire is suitable to support it while burning.
Rockets & Aerial Shells
When most people think of 'fireworks' an aerial shell probably comes to mind. These are the fireworks that are shot into the sky to explode. Some modern fireworks are launched using compressed air as a propellent and exploded using an electronic timer, but most aerial shells remain launched and exploded using gunpowder. Gunpowder-based aerial shells essentially function like two-stage rockets. The first stage of an aerial shell is a tube containing gunpowder, that is lit with a fuse much like a large firecracker. The difference is that the gunpowder is used to propel the firework into the air rather than explode the tube. There is a hole at the bottom of the firework so the expanding nitrogen and carbon dioxide gases launch the firework into the sky. The second stage of the aerial shell is a package of gunpowder, more oxidizer, and colorants. The packing of the components determines the shape of the firework.

Sparklers are a type of firework that produces a shower of glittery sparks, but does not explode.
Sparklers are a type of firework that produces a shower of glittery sparks, but does not explode.

Hair Color Chemistry Haircoloring: Bleaching & Dyeing

The first safe commercial haircolor was created in 1909 by French chemist Eugene Schuller, using the chemical paraphenylenediamine. Hair coloring is very popular today, with over 75% of women coloring their hair and a growing percentage of men following suit. How does haircolor work? It's the result of a series of chemical reactions between the molecules in hair, pigments, as well as peroxide and ammonia, if present.
What is Hair?
Hair is mainly keratin, the same protein found in skin and fingernails. The natural color of hair depends on the ratio and quantities of two other proteins, eumelanin and phaeomelanin. Eumelanin is responsible for brown to black hair shades while phaeomelanin is responsible for golden blond, ginger, and red colors. The absence of either type of melanin produces white/gray hair.
Natural Colorants
People have been coloring their hair for thousands of years using plants and minerals. Some of these natural agents contain pigments (e.g., henna, black walnut shells) and others contain natural bleaching agents or cause reactions that change the color of hair (e.g., vinegar). Natural pigments generally work by coating the hair shaft with color. Some natural colorants last through several shampoos, but they aren't necessarily safer or more gentle than modern formulations. It's difficult to get consistent results using natural colorants, plus some people are allergic to the ingredients.
Temporary Hair Color
Temporary or semi-permanent haircolors may deposit acidic dyes onto the outside of the hair shaft or may consist of small pigment molecules that can slip inside the hair shaft, using a small amount of peroxide or none at all. In some cases, a collection of several colorant molecules enter the hair to form a larger complex inside the hair shaft. Shampooing will eventually dislodge temporary hair color. These products don't contain ammonia, meaning the hair shaft isn't opened up during processing and the hair's natural color is retained once the product washes out.
How Lightening Works
Bleach is used to lighten hair. The bleach reacts with the melanin in hair, removing the color in an irreversible chemical reaction. The bleach oxidizes the melanin molecule. The melanin is still present, but the oxidized molecule is colorless. However, bleached hair tends to have a pale yellow tint. The yellow color is the natural color of keratin, the structural protein in hair. Also, bleach reacts more readily with the dark eumelanin pigment than with the phaeomelanin, so some gold or red residual color may remain after lightening. Hydrogen peroxide is one of the most common lightening agents. The peroxide is used in an alkaline solution, which opens the hair shaft to allow the peroxide to react with the melanin.
Permanent Hair Color
The outer layer of the hair shaft, its cuticle, must be opened before permanent color can be deposited into the hair. Once the cuticle is open, the dye reacts with the inner portion of the hair, the cortex, to deposit or remove the color. Most permanent hair colors use a two-step process (usually occurring simultaneously) which first removes the original color of the hair and then deposits a new color. It's essentially the same process as lightening, except a colorant is then bonded within the hair shaft. Ammonia is the alkaline chemical that opens the cuticle and allows the hair color to penetrate the cortex of the hair. It also acts as a catalyst when the permanent hair color comes together with the peroxide. Peroxide is used as the developer or oxidizing agent. The developer removes pre-existing color. Peroxide breaks chemical bonds in hair, releasing sulfur, which accounts for the characteristic odor of haircolor. As the melanin is decolorized, a new permanent color is bonded to the hair cortex. Various types of alcohols and conditioners may also be present in hair color. The conditioners close the cuticle after coloring to seal in and protect the new color.

Periodic Table Elements in Fireworks

Periodic Table
Elements in Fireworks
Fireworks rely on the chemical characteristics of the elements that are used to make them. This special periodic table highlights the elements that have significance to fireworks and pyrotechnics. Click on the element to see what it does.
More Information

Toxic Chemicals in Cosmetics Hazardous Chemicals in Cosmetics and Personal Care Product

Some of the ingredients in cosmetics and personal care products are chemicals that may be hazardous to your health. Take a look at some of the ingredients to watch for and the health concerns raised by these chemicals.


This is the two-dimensional chemical structure of the antibacterial and antifungal agent triclosan.Harbin, public domain
Antibacterials (e.g., Triclosan) are found in many products, such as hand soaps, deodorants, toothpastes and body washes.

Health Hazards: Some antibacterial agents are absorbed through the skin. Triclosan has been shown to be secreted in breast milk. These chemicals may be toxic or carcinogenic. One study has found antibacterials may interfere with the functioning of testosterone in cells. Antibacterials can kill the 'good' protective bacteria as well as pathogens, actually increasing susceptibility to infection. The products may increase the rate of development of resistant strains of bacteria.

butyl acetate

Butyl acetate is found in nail strengtheners and nail polishes.

Health Hazards: Butyl acetate vapors may cause dizziness or drowsiness. Continued use of a product containing butyl acetate may cause skin to crack and become dry.

butylated hydroxytoluene

Butylated hydroxytoluene is found in a variety of cosmetics and personal care products. It is an antioxidant which helps slow the rate at which a product changes color over time.

Health Hazards: Butylated hydroxytoluene may cause skin and eye irritation.

coal tar

Coal tar is used to control itching and scaling, to soften skin, and as a colorant.

Health Hazards: Coal tar is a human carcinogen.

diethanolamine (DEA)

This is the two-dimensional chemical structure of diethanolamine or DEA.Edgar181, public domain
Diethanolamine is a contaminant associated with cocamide DEA and lauramide DEA, which are used as emulsifiers and foaming agents in products such as shampoos, shaving creams, moisturizers, and baby washes.

Health Hazards: DEA can be absorbed into the body through the skin. It can act as a carcinogen and can be converted to nitrosamine, which is also carcinogenic. DEA is a hormone disruptor and robs the body of choline needed for fetal brain development.


This is a contaminant that may be associated with sodium laureth sulfate, PEG, and most ethoxylated ingredients with names ending in -eth. These ingredients are found in many products, most notably shampoos and body washes.

1,4 dioxane is known to cause cancer in animals and has a high probability of carcinogenicity in humans.


Formaldehyde (IUPAC name methanal) is a chemical compound that is the simplest aldehyde.Ben Mills
Formaldehyde is used as a disinfectant and preservative in a variety of products, such as nail polish, soap, deodorant, shaving cream, eyelash adhesive and shampoo. Even when it isn't listed as an ingredient, it can result from the breakdown of other ingredients, most notably diazolidinyl urea, imidazolidinyl urea and quaternium compounds.

Health Hazards: The European Union has banned the use of formaldehyde in cosmetics and personal care products. It is associated with multiple health concerns, such as respiratory tract and eye irritation, cancer, immune system damage, genetic damage, and triggering asthma.


The catch-all name "fragrance" may be used to indicate any of a number of chemicals in a personal care product.

Health Hazards: Many fragrances are toxic. Some of these fragrances may be phthalates, which can act as obesogens (cause obesity) and may otherwise disrupt normal endocrine function, including reproductive health. Phthalates may cause developmental defects and delays.


Crystals of lead (II) acetate or sugar of lead.Dormroomchemist,
Lead typically occurs as a contaminant, such as in hydrated silica, an ingredient in toothpaste. Lead acetate is added as an ingredient in some lipsticks and men's hair dye.

Health Hazards: Lead is a neurotoxin. It can cause brain damage and developmental delays even at extremely low concentrations.


Mercury is a heavy silvery metal that is liquid at room temperature.Femto/Elementbox04,
The FDA permits the use of mercury compounds in eye makeup at concentrations up to 65 parts per million. The preservative thimerosol, found in some mascaras, is a mercury-containing product.

Health Hazards: Mercury is associated with a host of health concerns including allergic reactions, skin irritation, toxicity, neurological damage, bioacculumation, and environmental damage. Mercury readily passes into the body through the skin, so normal use of the product results in exposure.


Talc is used to absorb moisture and provide a hint of sparkle. It is found in eye shadow, blush, baby powder, deodorant and soap.

Talc is known to act as a human carcinogen and has been directly linked to ovarian cancer. Talc can act similarly to asbestos when inhaled and may lead to the formation of lung tumors.


This is the two-dimensional chemical structure of toluene, also known as methylbenzene or toluol.NEUROtiker, public domain
Toluene is found in nail polish and hair dye as a solvent, to improve adhesion, and to add gloss.

Health Hazard: Toluene is toxic. It is associated with reproductive and developmental damage. Toluene may be carcinogenic. In addition to decreasing fertility, toluene may cause liver and kidney damage.

Elements in the Human Body

Find out what elements are in the human body and what these elements do.
99% of the mass of the human body is made up of only six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Every organic molecule contains carbon. Since 65-90% of each body cell consists of water (by weight), it isn't surprising that oxygen and hydrogen are major components of the body.Here's is a look at the major elements in the body and what these elements do.

Images 1-11 of 11

Liquid oxygen is blue.OxygenPhotograph of graphite, one of the forms of elemental carbon.CarbonNGC 604, a region of ionized hydrogen in the Triangulum Galaxy.HydrogenImage of solid, liquid, and gaseous nitrogen.Nitrogen
Calcium is a metal.CalciumRed phosphorus is one of several forms taken by this element.PhosphorusChunk of potassium metal with peroxides/superoxides and ozonide on its surface.PotassiumSodium metal chunks under mineral oil.Sodium
This is a sample of pure chlorine gas. Chlorine gas is a pale greenish yellow color.ChlorinePhotograph of the element magnesium, with a penny to indicate size of the sample.MagnesiumCrystals of the nonmetallic element sulfur.Sulfur

Resources of Chemistry Topics

Chemistry Topics

(adapted from "Chemistry Cassettes")
These learning resources are designed for individual, self-paced learning and are appropriate for post-16 students in schools, colleges and universities
They were originally created as cassettes and booklets by the Educational Techniques Group of the RSC - hence the original name "Chemistry Cassettes". They are now available for personal private study in MP3 and PDF format.

Instructions and suggestions
MP3 files can played on many different types of software.
© Educational Techniques Group Trust

Chemistry Topics

Make a pH Rainbow Wand~~

Make a pH Rainbow Wand

Friday October 22, 2010
Here's an easy and colorful chemistry demonstration for you. Take a long glass tube and fill it with Universal Indicator solution. Add a few drops of 0.02M HCl to one end of the tube and seal it with a stopper. Add a couple of drops of 0.02M NaOH to the other end of the tube and seal it. The Universal Indicator will respond to the pH gradient by providing you with a lovely rainbow. You can invert the tube a few times to speed things up.

You can get a similar result using home chemistry. Fill a clear straw with red cabbage juice. Add a little lemon juice or vinegar to one end of the straw. Add a few drops of baking soda or laundry detergent solution to the other end of the straw.Another option is to set up a line of test tubes. Fill the tubes with liquids exhibiting a range of pH values and add universal indicator or cabbage juice to elicit a color change. Here's what you get with cabbage juice:

Red Cabbage Juice pH Indicator (V. Belkhir)

Where Does Alcohol Come From?

Where Does Alcohol Come From?

Saturday October 23, 2010
Ethanol (Ben Mills)The alcohol that you can drink is ethyl alcohol or ethanol. It is produced by fermenting carbohydrates, such as sugars or starches. Fermentation is an anerobic process used by yeast to convert sugars into energy. Ethanol and carbon dioxide are waste products of the reaction. The reaction for the fermentation of glucose to produce ethanol and carbon dioxide is: C6H12O6 → 2C2H5OH + 2CO2

The fermented product may be used (e.g., wine) or distillation may be used to concentrate and purify the alcohol (e.g., vodka, tequila).

Just about any plant matter can be used to produce alcohol. Here is a list of the source material for several popular alcoholic beverages.

Ale - fermented from malt with hops
Beer - brewed and fermented from malted cereal grain (as barley), flavored with hops
Bourbon - whiskey distilled from a mash of not less than 51 percent corn and aged in new charred oak barrels for a minimum of two years
Brandy - distilled from wine or fermented fruit juice
Cognac - a brandy distilled from white wine from a specific region of France
Gin - distilled or redistilled neutral grain spirits from a variety of sources, flavored with juniper berries and other aromatics
Rum - distilled from a sugarcane product such as molasses or sugarcane juice
Sake - produced by a brewing process using rice
Tequila - a Mexican liquor distilled from blue agave
Vodka - distilled from a mash as of potatoes, rye or wheat
Whiskey - distilled from mash of grain such as rye, corn, or barley
Scotch - whiskey distilled in Scotland typically from malted barley<
Wine - fermented juice of fresh grapes and/or other fruit (e.g., blackberry wine)

If you have other types of alcohol you'd like to add to the list, feel free to post a response.

Saturday, October 23, 2010

Mixtures and compounds.wmv

Li nk to video Mixtures and compounds.wmv
(The differences of mixture and compound)

Mixtures are heterogeneous forms of matter. Mixtures are composed of variable proportions of molecules and atoms.
Compounds are homogeneous forms of matter. Their constituent elements (atoms and/or ions) are always present in fixed proportions

Properties of Mixtures

  • The composition of a mixture is variable.
  • Each of its components retains its characteristic properties.
  • Its components are easily separated.

Properties of Compounds

  • The relative proportions of the elements in a compound are fixed.
  • The components of a compound do not retain their individual properties. Both sodium and chlorine are poisonous; their compound, table salt - NaCl - is absolutely essential to life.
  • It takes large inputs of energy to separate the components of a compound.

Separating the Components of a Mixture

Most laboratory work in biology requires the use of techniques to separate the components of mixtures. This is done by exploiting some property that distinguishes the components, such as their relative
  • size
  • density
  • solubility
  • electrical charge


Dialysis is the separation of small solute molecules or ions (e.g., glucose, Na+, Cl-) from macromolecules (e.g., starch) by virtue of their differing rates of diffusion through a differentially permeable membrane.

An example:

Cellophane is perforated with tiny pores that permit ions and small molecules to pass through but exclude molecules with molecular weights greater than about 12,000. If we fill a piece of cellophane tubing with a mixture of starch and sugar and place it in pure water, the sugar molecules (red dots) will diffuse out into the water until equilibrium is reached; that is, until their concentration is equal on both sides of the membrane. Because of their large size, all the starch (blue disks) will be retained within the tubing.


Chromatography is the term used for several techniques for separating the components of a mixture. Follow the links below for examples.
Link to a description of paper chromatography, where the molecules are separated by size and solubility
Link to a description of exclusion chromatography, where the molecules in a mixture are separated by size.
Link to a description of affinity chromatography, where molecules are separated on the basis of their attraction to material in the chromatographic column.


Electrophoresis uses a direct electric current to separate the components of a mixture by the differing electrical charge.
Link to a description of how the proteins in blood serum are separated by electrophoresis.

Pure Substances

Some of the pure substances isolated from mixtures cannot be further broken down. Oxygen (O2) is an example. It is one of the elements; the fundamental building blocks of matter.
Link to discussion of elements.
Most pure substances are compounds. Table salt, sodium chloride (NaCl), is an example; water (H2O) is another. If we pass an electrical current through molten NaCl, two new substances will be formed:
  • sodium, a shiny metal so reactive that it must be stored out of contact with the air
  • chlorine, a yellowish poisonous gas.
In this operation, a compound has been decomposed into its constitutive elements. Note the differences between separating the components of a mixture and those of a compound.
  • The decomposition of NaCl required a large input of energy. This is because of the strength of the ionic bonds holding the Na and Cl atoms together.
  • The ratio of the weights of the two products are always 23 parts of sodium to 35.5 parts of chlorine. This reflects:
    • the invariance of the ratio (1:1 in this case) of the number of atoms in a compound
      Link to discussion of valence.
    • the relative weights (23:35.5) of the atoms in table salt.
  • The properties of the components of the compound are not the same as those of the compound itself. Both sodium and chlorine are hazardous to life; their compound, sodium chloride, is a vital ingredient of all animal diets.

Wednesday, October 20, 2010

About Camstudio

What is it?
CamStudio is able to record all screen and audio activity on your computer and create industry-standard AVI video files and using its built-in SWF Producer can turn those AVIs into lean, mean, bandwidth-friendly Streaming Flash videos (SWFs)
Here are just a few ways you can use this software:
  • You can use it to create demonstration videos for any software program
  • Or how about creating a set of videos answering your most frequently asked questions?
  • You can create video tutorials for school or college class
  • You can use it to record a recurring problem with your computer so you can show technical support people
  • You can use it to create video-based information products you can sell
  • You can even use it to record new tricks and techniques you discover on your favourite software program, before you forget them
  • Don't like the sound of your voice? No problem.
    CamStudio can also add high-quality, anti-aliased (no jagged edges) screen captions to your recordings in seconds and with the unique Video Annotation feature you can even personalise your videos by including a webcam movie of yourself "picture-in-picture" over your desktop.
    And if all that wasn't enough, CamStudio also comes with its own Lossless Codec that produces crystal clear results with a much smaller filesize compared with other more popular codecs, like Microsoft Video 1.
    You have total control over the output of your video: you can choose to use custom cursors, to record the whole screen or just a section of it and can reduce or increase the quality of the recording depending on if you want smaller videos (for emailing to people, for instance) or you can have "best quality" ones for burning onto CD/DVD.
    But all of these features would be worthless if CamStudio wasn't easy to use ... fortunately that's not the case. CamStudio can be learned in a matter of minutes and comes with a comprehensive built-in helpfile, so if you do manage to get stuck, you can simply hit "Help" and get the answers you need.

    So where can I get it and how much does it cost?
    You can download and use it completely free - yep - completely 100% free for your personal and commercial projects as CamStudio and the Codec are released under the GPL (for more details on this license, click here.)
    There are no royalties or any monies to pay - although if you do use it for a commercial product, I wouldn't say no to a copy of whatever you produce

    Designed For XP - Windows Vista Capable
    Download Links
    CamStudio 2.0: CamStudio20.exe
    To manually install the codec, download the zipfile version, extract the contents to a folder, right click the camcodec.inf file and select Install.
    If you don't have a lot of experience or just plain can't be bothered with all that mucking around [grin], download the EXE version and double click it to begin the install process.

    CamStudio's History
    Over the last few months, quite a people have asked me about CamStudio's history and the confusion with the V2.1 that's around, so I thought I'd explain what the situation is, as I understand it ...
    CamStudio was originally released by a company called RenderSoft who were subsequently bought by a company called eHelp who used some of the technology in their program, RoboDemo ...
    Some time later, eHelp was bought by Macromedia who wanted RoboDemo (which was to become Captivate) ...
    Knowing that CamStudio did some of the stuff RoboDemo did for free (mainly export to streaming Flash), it looks like they released a newer version of CamStudio (2.1) which fixed some bugs but most importantly, removed certain features. Gone was the ability to create SWFs, added was the requirement to register to use it, and over time, links to the various webpages that had CamStudio and its source code, became broken.
    However, I've managed to find the earlier version 2.0 complete with the related CamStudio video codec (comparable to Techsmith's excellent TSCC), the source code for both and just put the website up so people can download them ...
    A number of people have mentioned having trouble viewing SWF videos generated by CamStudio. It turns out there's a bug which means you can't see anything if you try watching them with Netscape or Firefox (Internet Explorer works fine) ...
    The next update (2.5) will fix this but until then, here's a temporary workaround:
    Open the related HTML to the SWF you've just generated and look for the line starting with the "EMBED SRC" command ...
    Change the Width and Height values in this line to match values in the line starting with "OBJECT CLASSID".
    Save the file and you should be good to go ...
    I seem to be getting a lot of questions about a registration code ... the version of CamStudio available from this site (v2.0) doesn't require registration AND has more features, so uninstall v2.1 from your system, download and install v2.0 from here and you're good to go!
    If your computer's memory or virtual memory usage starts climbing rapidly when viewing a SWF authored by CamStudio to the point when your PC locks up so you have to reboot it, recreate the SWF from your source AVI file and in SWF Producer, make sure you select the Advanced tab and check the Memory Management tickbox (Manage Flash player internal memory). That should sort the problem out. Thanks to Ben Ward for the fix.

    AudioFlash is free audio recording software that will record you speaking via your computer and put it on your website with some nifty SWF control buttons.
    Just wanted to let you know, I've released another tool called Podcast Autocue, which you can download as well from here: Podcast Software
    There's now a "proper" blog for CamStudio where I'll post all the latest information, including updates on CamStudio V2.5. Click here to go to the blog

    CamStudio Update List
    If you'd like to be notified when I have some news related to CamStudio, signup using the form at the top of this page and you'll be "in the loop" ...
    Obviously, I won't be spamming you and your details won't be sold, given, traded or hired to any other third party under any circumstances.
    Enter your details here to add yourself to the CamStudio Users Update List
    Spread The Word ...
    I'd love to get CamStudio into the Top 10 Most Popular downloads at SourceForge ... for no other reason than ... um ... I'd like to, so tell as many people as possible ...
    If you'd like to link back to this site, here's some example code you can use:
    CamStudio - Free Streaming Video Desktop Recording Software
    A Plea For Help ...
    I've got big plans for CamStudio and want to continously improve it and the Codec as well ... but I'm not a programmer.
    The potential for CamStudio to be used as a professional training and support tool is huge and not just in the information technology and internet marketing arenas, but also in diverse markets and tasks like home eduation, recording online geneological research, keeping a video record of special offer prices on your favourite snowboarding (or whatever) website - you get the idea ...
    It doesn't matter if you're at home in Las Vegas or on an Alaskan Cruise - if you've got a laptop or PC you can use CamStudio.
    So if there are any Visual C++ programmers out there that have Flash, video encoding and codec experience who'd like a challenge, please get in touch.
    So, at some point in the near future I'd like to start accepting donations so any coders that work on this project will get some kind of financial reward in addition to the warm, fuzzy feeling they get from helping to resurrect this cracking piece of software ... so if you're feeling generous, please get in touch at the email address above and let me know.
    I'd also love to get your feedback on CamStudio ... what you liked, what you thought sucked and what you think is missing.

      By the way...

    You can use VirtualDub (free!) to change the frame-rate for playback to anything you like.

    Step 1 - load the video
    Step 2 - in either "Full Processing" (you're changing compression also) or "Direct Stream Copy" (you're just changing the frame rate) modes, under the "Video" menu select "Frame Rate"
    Step 3 - Under "Source Rate Adjustment" select the second radio button, "Change frame rate to (fps) and enter the desired frame rate. For time-lapse recorded stuff, selecting a slow frame rate of 1 frame per second or so will produce slide-show-like results. Move to higher numbers to speed up the playback.
    Step 4 - Process all frames. Click "OK"
    Step 5 - Under "File" select "Save as AVI" and re-save the video with the new frame rate for playback with a different descriptive filename (filename1fps, for instance)

    Now you'll have a time-lapse movie that outputs nicely. For really long intervals (like 10 minutes between frames), you can instead opt to output each frame as a separate "movie" to be loaded into an editor to allow cross-fading between every frame. VirtualDub does not have support for adding in transitions - I've only done such a thing in Windows Movie Maker.

    Step 1 - load the video
    Step 2 - Under "File" select "Save Segmented AVI"
    Step 3 - Check the box "Limit number of video frames per segment" and enter "1" there.
    Step 4 - Set "File segment size limit in MB (50-2048) to 50.
    Step 5 - select/create a folder to hold all the created segments.
    Step 6 - Click "Save"

    Or, alternatively, you can output all your frames as bitmap, jpeg (recommended), png or Targa images to use in Windows Photo Story 3, Quicktime Pro or another slide-show creation program to create a slide-show with transitions.

    Step 1 - load the video
    Step 2 - Under "File" select "Export ==> Image Sequence"
    Step 3 - Under "Filename" enter a base filename - each frame will add a number to that base filename
    Step 4 - Click on the radio button for the format you want to export the frames as and, if applicable, set the quality slider all the way to the right.
    Step 5 - click the box with three dots ... and select your target directory (this directory must already be created).
    Step 6 - Click OK

    Now the folder of images can be imported into Photo Story 3 or dropped into Quicktime Pro with transitions added.

Falsafah Pendidikan

Falsafah Pendidikan Kebangsaan

Falsafah Pendidikan Kebangsaan (FPK) dulunya disebut Falsafah Pendidikan Negara (FPN) merupakan dasar kepada pendidikan di Malaysia. Hal ini bermakna, semua aktiviti pendidikan dan persekolahan di Malaysia mestilah selaras dengan FPK ini. Justeru setiap bakal guru di Malaysia diwajibkan membaca, memahami dan mengingati falsafah ini agar setiap tindakan mereka melalui proses pengajaran dan pembelajaran sentiasa berada dilandasan yang betul. Intipati utama dalam FTK ini ialah melahirkan insan seimbang dari segi jasmani, emosi, rohani dan intelektual. Sosial yang sering disebut oleh guru-guru sebagai JERIS. Perlu diingat bahawa tidak ada yang lebih utama antara keempat-empat unsur tersebut, yakni tidak boleh dikatakan jasmani lebih penting daripada intelek atau sebaliknya.

Berikut adalah teks lengkap Falsafah Pendidikan Kebangsaan.
"Pendidikan di Malaysia adalah satu usaha berterusan ke arah memperkembangkan lagi potensi individu secara menyeluruh dan bersepadu untuk mewujudkan insan yang seimbang dan harmonis dari segi intelek, rohani, emosi dan jasmani. Usaha ini adalah bagi melahirkan rakyat Malaysia yang berilmu pengetahuan, berakhlak mulia, bertanggungjawab, berketrampilan dan berkeupayaan mencapai kesejahteraan diri serta memberi sumbangan terhadap keharmonian dan kemakmuran keluarga, masyarakat dan negara."

Falsafah Pendidikan Guru (FPG) 
Kami guru-guru Malaysia yakin bahawa tujuan utama pendidikan ialah berusaha menuju ke arah pembentukan warganegara yang berilmu, yang taat setia, yang bertanggung jawab dan berkebolehan, yang menyedari betapa penting usaha menuju kepada arah kebenaran dan ke arah pencapaian hasrat yang gemilang, dan yang percaya kepada demokrasi, kebebasan perseorangan dan prinsip-prinsip Rukun Negara.

Matlamat FPG
-Membina insan guru yang berakhlak mulia, berilmu, kreatif dan berdaya tahan yang boleh mendidik murid-murid dengan cekap dan berkesan.
-Mengembangkan maktab perguruan sebagai pusat rujukan dalam bidang keguruan
-Meningkatkan pengetahuan dan kecekapan guru terlatih secara berkesan.- Mengeluarkan guru permulaan yang mencukupi untuk sekolah-sekolah rendah dan menengah di Malaysia.

Berikut adalah teks lengkap Falsafah Pendidikan Guru.
  “Guru yang berpekerti mulia, berpandangan prograsif dan saintifik, bersedia menjunjung aspirasi Negara serta menyanjung warisan kebudayaan negara, menjamin perkembangan individu dan memelihra suatu masyarakat yang bersatu padu, demokratik, progresif dan berdisiplin”.

Friday, October 8, 2010

Mentos-Diet Coke Reaction

Have you heard about this experiment that some people have done with Mentos and Diet Coke? If you put a Mentos into a bottle of Diet Coke, it causes a geyser type reaction, causing the Diet Coke to shoot up with a powerful force. I have heard people talk about this and claim that it proves that Diet Coke is bad for you. I don't see how it proves that anything is bad for you, but simply that a reaction happens.

Some students at Appalachian State University actually studied why the reaction happens. They just published their results in the June 2008 issue of the American Journal of Physics. Here is what they found:

"In an opened container of soda, carbon dioxide gas bubbles out over the course of minutes or hours until the concentration of carbon dioxide left in the soda is proportional to the carbon dioxide in the surrounding air. This de-fizzing reaction is slow because the surface tension of the liquid is very high, which keeps the gas bubbles trapped.
But when a Mentos is dropped in the beverage, it breaks the surface tension and as it falls the candy’s surfactant coating further reduces the surface tension of the liquid. The candy’s rough surface also provides growth sites for the gas, making it easier for carbonation to escape as a foam geyser.
The geyser also occurs when sand, salt or lifesavers were added to the Diet Coke, but the mass lost and volume traveled is much less spectacular."

I will be able to sleep better tonight now knowing why this reaction happens, how about you? If you do decide to try this experiment at home, use caution when you drop it in and run for cover. The liquid can explode nearly 30 feet!

Serious Problems With Radiometric DATING