Pressure conversions

A radio station announcer reports the atmospheric pressure to be 99.6 kPa. What is the pressure in atmospheres? In millimeters of mercury?

Look up conversions factors in a table to convert between kilopascals and atmospheres and millimeters of mercury. Use a conversion factor approach to solve the problem:
99.6 kPa x 1 atm/101.3 kPa = 0.983 atm
0.983 atm x 760 mm Hg/1 atm = 747 mm Hg


0.983 atm; 747 mm Hg

Yasiel Hernandez

World's smallest pipette

Smallest pipette delivers zeptolitre volumes16 April 2007

The world's smallest pipette has been developed by US scientists. It is capable of dispensing drops of a molten gold-germanium alloy with a volume of a few zeptolitres, that is, a billionth of a trillionth of a litre. Watching these tiny drops led Eli and Peter Sutter of the Brookhaven National Laboratory, New York to make observations that challenge the classical theory of crystallisation. Their findings are published in the journal Nature Materials this week.1
Close up on world's smallest pipette
© Nature

To create the nanopipette the authors used a gold catalyst to grow a germanium nanotube with a tip containing a reservoir of molten Au-Ge alloy. The whole thing was encapsulated within sheets of graphene which was pierced at the tip with an electron beam allowing the melt to flow out.

When Eli Sutter explains that these drops are 'quite small', it's something of an understatement. The previous record was an attolitre pipette, producing volumes around 100 times larger.2 Now, drops containing only a few thousand atoms have been dispensed, and their size means they behave differently to bulk liquids when cooled to just above their melting point. They are too large, however for computer simulation which becomes too complicated above a few hundred atoms.

Conventional crystallisation theory states that crystals nucleate around an impurity somewhere in the bulk and grow outward from that point. But the pipette produces droplets so pure that this could be ruled out, meaning Sutter didn't know what to expect watching the drops cool with a transmission electron microscope.
Dancing droplet

© Nature
In fact, just above the melting point she saw the drop start to develop thin solid-like flat facets at the surface. These facets would disappear and re-appear elsewhere on the surface 'a little bit like a dance', said Sutter. A couple more degrees cooler and the facets became frozen in as the drop solidified from the outside in.

The drops were studied while suspended from the pipette tip by a 10 Å thread of alloy. This removes any interactions between a container and the drop surface that could hide such subtle effects. The drop is 'practically levitating' said Sutter, who also hinted that 'quasi-free' drops like these might shed light on how atmospheric droplets behave, with implications for modelling climate behaviour. Sutter cautions that the conditions in these experiments would be make it impossible to repeat them with water, however.

Andreas Bruckbauer of the Department of Chemistry, University of Cambridge said this was 'a truly amazing method' of dispensing liquids, for a specialized but 'very interesting and very important' purpose.

Harry Heinzelmann of the Centre Suisse d'Electronique et de Microtechnique in Switzerland developed the previous smallest pipette, and is similarly impressed. The new method is limited by the material being dispensed, but 'allows scientific work that was not possible before' and complements existing techniques, he said. Sutter now plans to repeat the experiments using alloys with different surface energies, and hopes this could lead to improved control of drop growth to atomic resolution.

Yasiel Hernandez

Bioethanol fuel

Bioethanol fuel 'as big a health risk as gasoline'18 April 2007
The use of ethanol as a gasoline substitute for motor vehicles may not be the environmental panacea that its proponents would have us believe, according to a US atmospheric scientist.
Bioethanol - ethanol derived from the fermentation of crops such as maize or sugar - is becoming increasingly available as a 'green' and sustainable alternative to gasoline. It is often sold at the fuel pumps as E85 - an 85:15 mixture of ethanol and gasoline.
How 'green' is green?Now, however, Mark Jacobson of Stanford University is calling into question the environmental credentials of fuels consisting mainly of bioethanol. Jacobson ran computer models of the impacts on atmospheric pollution and human health of vehicles running exclusively on an ethanol mixture and concluded that the number of respiratory-related deaths and illness would increase.
'Our results show that a high blend of ethanol poses an equal or greater risk to public health than gasoline,' Jacobson said.
He ran a series of simulations of atmospheric conditions around Los Angeles in the year 2020 comparing two scenarios: all vehicles running on gasoline versus all vehicles running on E85.
'We found that E85 vehicles reduce atmospheric levels of two carcinogens, benzene and butadiene, but increase two others - formaldehyde and acetaldehyde,' Jacobson said. 'As a result, cancer rates for E85 are likely to be similar to those for gasoline. However, in some parts of the country, E85 significantly increased ozone, a prime ingredient of smog.' The increased ozone, Jacobson suggested, would result in more asthma-related admissions to hospitals.
'There are alternatives, such as battery-electric, plug-in-hybrid and hydrogen-fuel cell vehicles, whose energy can be derived from wind or solar power,' Jacobson said. 'It would seem prudent, therefore, to address climate, health and energy with technologies that have known benefits.'
The Ford motor company, which produces 'Flexi-Fuel' cars that can run on both E85 and gasoline, was unimpressed by Jacobson's findings.
'The phasing in of E85 is in the interest of developing energy alternatives to petroleum and to encourage the use of renewable fuel to help with CO2 reduction for climate change,' a spokesman told Chemistry World. 'Local emission regulations, such as hydrocarbons, aldehydes or subsequent ozone, are not the compelling reason to pursue E85.'
In any event, the spokesman said, Ford's flexible fuel vehicles using E85 'must comply with the regulated emissions of HC, CO, NOx, formaldehyde, and particulate, as with any vehicle. Air quality regions, such as southern California, must be satisfied that the test results of these vehicles are acceptable for local air quality requirements. Vehicles that do not comply will not be sold.' He added that the baseline data used by Jacobson, from 2002, 'is not likely to be very representative of 2020 vehicles, particularly in ozone-constrained regions such as southern California where requirements are stringent, so care is needed in interpreting data this far into the future while technology continues to evolve. 'Unburned ethanol and associated acetaldehyde are concerns with E85 due to lower exhaust temperatures, making high catalyst efficiency more difficult, but we also think this issue can be resolved by the time E85 will be prevalent.'

Yasiel Hernandez

Making pH Paper Test Strips

Make pH Paper Test Strips
This is an example of a project that doesn't require a lab or special chemicals and that is safe and easy enough for kids to do. You can make your own pH paper using nothing more complicated than a cabbage and coffee filters. My instructions involve using a blender and a microwave, but you can just as easily chop the cabbage, steep it like a tea in a small amount of boiling water, and make pH paper from the juice. You say you don't have cabbage? That's okay, too. There are many other common plants that you can substitute. The reason cabbage is most often used is because it exhibits a wide color change range.
Greenish Yellow

Yasiel Hernandez


Have You Selected Wrong Materials for Chemicals?

this article i found it pretty interesting because Chemicals are very much a part of our lifestyles. Every household detergent, solvent, and bleach that you use in your homes is a result of some production efforts from manufacturing plants somewhere in the world around you. Fertilizer, automobile radiator coolant, shampoo, soap, insecticide, paint solvent, lubricants, fuel oil are just a few that I can name right now. I’m sure you can find more around you, but you get the point. We use chemicals everywhere. One of the main jobs for Plant Engineers is to maintain the numerous pumps installed at their plant. These pumps can count into the hundreds or even thousands, depending on the size of the plant. So you should realize that to do a proper preventive maintenance, it is no mean task. There must be regular schedules, proper tracking of jobs done, available manpower and skills, suitable tools, replacement parts, materials and a proper system of administration of all these.

Sometimes, even with all the maintenance activities being carried out, pumps do fail. And when they do, plant engineers will have to find out what causes them to fail. Especially with new pumps where there is very little record trend of breakdown, engineers will be hard pressed into finding solutions for this. This is when experience helps in pinpointing the causes of the failure. Engineers in such chemical processing plants need to know what materials are suitable to be used for their process. It is much more complex than just selecting materials for water pumps. Much detailed and careful selection choices based on the chemicals, the temperatures (because some of the plastic materials can weaken at temperatures that are considered normal for metals), chemical reactions, safety, spills and many others have to be taken.

With so many chemicals in use today, how do we know what materials can be used for what chemicals? Sometimes liquids to be pumped contain chemicals that are both corrosive and abrasive. Should we choose a plastic or a metal housing? Sometimes chemicals may become hot either through the process or through mis-operation of the system - perhaps, somebody forgot to open a valve. Plastic parts can weaken at high temperatures.

Rodrigo Monsalve

Green Sand!!!

Have you heard about any beach that has green sand??

This article that I foudn describes that this beach sand may be the only one in the world!!

The sand consists of spheres of olivine, or peridot. Each grain is a clear olive green. White sand primarily is quartz, which is an uncolored silicate (SiO2), and other light-colored minerals (white sand beaches in Hawaii, on the other hand, are almost entirely made from smoothed shells, or calcium carbonate, rather than inorganic minerals). Olivine is another silicate, though with magnesium and iron in its crystal matrix. The metals are responsible for the characteristic color.

As the author of the article shares her experience "You're not supposed to disturb sand at pretty much any beach in Hawaii, but I figure if you can walk on it, you can pick it up and photograph it. It's a deep layer of green, not just a sprinkling of green on top of regular sand. This beach is well worth the drive or hike to see firsthand"

Hopefully we could get to visit in ina near future!!!

Take care!! all you!!


Plastic modified to meet electronic needs

A U.S. scientist has modified a plastic so its ability to conduct electricity can be altered during manufacturing to meet future electronic device needs. Yueh-Lin Loo, an assistant professor of chemical engineering at The University of Texas at Austin, conducted her research with a plastic called polyaniline, which could serve as flexible, inexpensive wiring in future products such as military camouflage that changes colors, foldable electronic displays and medical sensors.
By combining polyaniline with a chemical that gives it conductivity, Loo discovered she could increase the plastic's conductivity one- to six-fold based on the version of the chemical added.
The results of her research involving the chemical polymer acid appear in the April 7 issue of the Journal of Materials Chemistry.
Copyright 2007 by United Press International. All Rights Reserved.
Further Information:
Posted: Vivian Coolen

Ice that Burns

You probably already know about regular ice -- frozen water -- and you may also be familiar with dry ice, frozen carbon dioxide. But have you every heard of ice that burns?
Methane hydrate, or gas hydrate, is an ice-like substance composed of methane (CH4) -- the main constituent of natural gas -- trapped inside cages of water molecules (H2O). Such a crystalline combination of a natural gas and water (known technically as a clathrate) looks very similar to ice but burns if it meets a lit match. It is formed at low temperatures and high pressures, with deposits found underneath permafrost in Arctic regions and beneath deep ocean floors.
Gas hydrates were first recognized 70 years ago and were considered a nuisance in the natural gas industry, an icy sludge that fouled natural gas pipelines. The fact that gas hydrates were first noticed in gas pipelines was no accident: pressurized lines contaminated with water happen to be a perfect environment for formation of the icy stuff.
In 1964, naturally occurring gas hydrates were found underground in a gas field in Siberia. Since then, geologists have found huge deposits of gas hydrates in ocean sediments that are at least 500 meters deep, where methane that is produced by decaying organisms or that is seeping up through the Earth's crust is trapped at high pressures (at least 26 times normal atmospheric pressure) and low temperatures (near the freezing point of water).
The U.S. Geological Survey and other studies have estimated that the energy locked up in methane hydrate deposits is equivalent to 250 trillion cubic meters of methane gas, more than twice the global reserves of all conventional gas, oil and coal deposits combined. The existence of this vast global storehouse of methane raises the possibility of using methane hydrate as a source of energy, especially since methane gas burns more efficiently and cleanly than any other fossil fuel, releasing less than half the amount of carbon dioxide when burned that oil and coal do.
CH4 + 2O2 CO2 + 2H2O (combustion of methane)
When brought to normal atmospheric pressure, methane hydrate will produce more than 160 times its original volume in gaseous methane. (Some have referred to it as a highly pressurized can of natural gas.) However, no method has been developed yet to extract the gas inexpensively, and no one knows how much is actually recoverable. A formidable obstacle to using hydrates as fuel is that when removed from its high-pressure,low-temperature environment the hydrate decomposes and releases the gas contained in it. Currently, there is no way to safely transport large amounts of hydrate to production facilities on land.
Gas hydrates could have serious implications for global warming. Methane, the main constituent of gas hydrates, is also a powerful greenhouse gas. It is 10 to 20 times more effective than carbon dioxide as a short-term greenhouse gas in causing climate warming. Thus, there is concern that release of even a small percentage of total deposits could have a serious effect on Earth's atmosphere.
There is controversy among scientists. Some believe that gas hydrates have contributed to climate changes several times during the last two million years. Some believe that fluctuating sea levels during the ice ages could have made large volumes of gas hydrate unstable, releasing great volumes of methane into the atmosphere. The current fear is that increasing global temperatures may also destabilize deposits of methane hydrate, releasing methane and producing rapid warming of Earth's atmosphere.

By- Linda Mamassian

Posted by- Karen Fuentes

Crusty Chemistry

Want to make a piece of pizza healthier? Try using whole-wheat dough. Give it a full 2 days to rise, and then cook the tomato pie a little longer and hotter than usual. That was the recipe shared last week by researchers at the American Chemical Society meeting in Chicago.
DEEP DISH BONANZA. The thick crust of "Chicago-style," deep-dish pizza makes it a good candidate for the longer, hotter baking that boosts whole wheat dough's antioxidant activity.iStockphoto
Jeffrey Moore and Liangli Lucy Yu of the University of Maryland at College Park have been experimenting with pizza-making techniques in hopes of unleashing the full antioxidant potential of trace nutrients in wheat bran. Oxidants, generally referred to as free radicals, are biologically reactive molecular fragments that can damage cells of the body. Many diseases stem from the body's inability to keep those fragments in check. However, studies have indicated that foods rich in antioxidants can quash such free radicals and sometimes spare tissues from damage.
Most pizza makers give their yeasty dough a few hours to ferment, the chemical-biological process responsible for its rise. Working with two common wheat flours, "we found that increasing fermentation time to 48 hours doubled the amount of antioxidants called phenolic acids in the dough," Moore says. In general, values climbed from about 4 micrograms of free, or unbound, phenolic acids per gram of starting wheat to 8 µg/g. Ferulic acid proved the main contributor to this antioxidant climb.
In a different set of experiments, the food chemists tinkered with baking conditions and then ran five different test-tube assays of the crust's antioxidant activity—its ability to quash free radicals. At the meeting, they reported finding a 60 percent increase in the crust's antioxidant activity for deep-dish, "Chicago-style," pizzas that had been baked at 400 °F for 14 minutes versus 7 minutes. If the scientists instead raised the temperature to 550°F, the antioxidant activity in a pizza baked for 7 minutes increased by 80 percent.
In principle, Moore says, pizza makers should be able to increase both baking time and temperature—if they watch the pie so it doesn't burn. Deep-dish pizzas are particularly good candidates for this recipe meddling, Moore says, because they generally require longer baking times than thin-crust pizzas do.
The Maryland team focused on whole wheat crust because it has abundant fiber—a nutrient short in most U.S. diets—and includes the source of most of the grain's antioxidants. Although white flour carries fewer antioxidants, crusts made from it should also be candidates for antioxidant boosting, Moore says. Nevertheless, he suspects that the spike wouldn't be nearly as impressive as for whole-wheat crust.
The researchers have begun probing why the antioxidant increase occurs. They suspect that something in fermentation and baking processes unleash phenolic acids otherwise rendered inert by being bound to other plant materials in flour.
Moore points out that there isn't anything magical about pizza dough. A similar tinkering with baking times and temperatures should give other whole wheat bakery goods—most notably breads—boosts in their antioxidant content and activity.

By: Janet Raloff

Posted: Karen fuentes


Device Uses Solar Energy To Convert Carbon Dioxide Into Fuel

There is a lot of time spent talking about what should be blamed for causing global warning and not enough on finding practical soloutions. Thankfully, scientists at the University of California are working on a way of exploiting sunlight to transfer greenhouse gas into useful products such as energy. The process involves splitting CO2 into carbon monoxide and oxygen. Doing this would have several benefits; it is more fuel efficient than splitting H2O, which is currently more common, it produces a useful chemical, which is used for various things such as making plastics, and more importantly, it reduces greenhouse gas.
Right now, the problem is making a semiconductor powerful enough to make the splitting of CO2 practical. They are looking at a gallium-phosphide semiconductor, which has a band gap large enough so that no additional energy source needs to be implemented for help. It is also a great absorber of energetic visible light.
Hopefully, they find out the missing piece of this puzzle as it can be very beneficial to our planet.

-Manuel Contreras

Here's the link to the article:


Nitric oxide-releasing polymers studied

U.S. scientists have created a new group of plastics that might have broad uses in medicine by releasing nitric oxide. The researchers -- Joseph Hrabie of the National Cancer Institute and colleagues at Northwestern University -- report synthesis of nitric oxide-releasing forms of the most commercially important polyacrylonitrile polymers. The new polymers include a textile, a plastic and a rubber.Hrabie said some of the materials continuously release small amounts of nitric oxide for months allowing the chemical to dilate blood vessels. The scientists believe such technology could be used to reduce undesirable effects such as blood vessel scaring and narrowing that tend to occur after coronary angioplasty and bypass surgery."Many applications of this chemistry in vascular surgery and other medical procedures can be envisioned," the researchers said. "Possible applications of these polymers include arterial stenting, bypass grafting and surgical endarterectomy."The research appeared in the April 4 issue of the Journal of the American Chemical Society.

Copyright 2007 by United Press International. All Rights Reserved.
Extra Information:
Posted by Vivian Coolen


NASA Predicts Non-Green Plants on Other Planets

Keeping with our planetary theme and life on other planets, NASA says there may be plants on other planets and they may be all sorts of different colors. The color of any alien plant is determined by the wavelength of light as well as the dominant color of photosynthesis on other planets. Both of these could drastically differ from our own sun's dominant wavelengths and our plants dominant photosynthesis color. The dominant color of photosynthesis may even be something like infrared. Finding this out is very useful; scientists can use the information to help determine the likeliness of life on distant planets as well as give us a better understanding of life on Earth.

Here's the link:
Manuel Contreras


Signs of water seen on planet outside solar system

Hope you guys like it!!!!!!!!!!!!

WASHINGTON (Reuters) - Evidence of water has been detected for the first time in a planet outside our solar system, an astronomer said on Tuesday, a tantalizing find for scientists eager to know whether life exists beyond Earth.
Travis Barman, an astronomer at Lowell Observatory in Flagstaff, Arizona, said water vapor has been found in the atmosphere of a large, Jupiter-like gaseous planet located 150 light years from Earth in the constellation Pegasus. The planet is known as HD 209458b.

Other scientists reported in February that they were unable to find evidence of water in this planet's atmosphere, as well as another Jupiter-like planet.

"I'm very confident," Barman said in an interview. "It's definitely good news because water has been predicted to be present in the atmosphere of this planet and many of the other ones for some time."

Lowell Observatory, a privately owned astronomical research institution, announced the finding, which has been accepted for publication in the Astrophysical Journal. The research was backed by NASA, it said.

The detection of the presence of water vapor was possible because this planet, from the vantage point of Earth, orbits directly in front of its star every 3-1/2 days, allowing crucial measurements to be made. It is what is known as a transiting planet.

Scientists searching for signs of life beyond Earth are keen to learn about the presence of water on other planets -- both in and beyond our solar system -- because water is thought to be fundamental to the existence of life.

Barman noted that a Jupiter-like gaseous planet such as this one, as opposed to a rocky one like Earth, is highly unlikely to harbor life, and said the finding about water vapor in its atmosphere does not answer one way or another questions about the existence of extraterrestrial life.


The findings, he said, "are not adequate to really address a question as deep and profound as the existence of life elsewhere. We're not there yet."

"Certainly this is part of that puzzle -- understanding the distribution of water in other solar systems is important for understanding whether or not conditions for life are possible. The presence of water does not exclude the possibility of life, but it doesn't mean it's there, either," Barman added.

He said his findings do provide good reason to believe other planets beyond our solar system also have water vapor in their atmospheres.

The conclusions stemmed from an analysis of Hubble Space Telescope measurements by Harvard University's Heather Knutson and new theoretical models developed by Barman, Lowell Observatory said.

Water is plentiful on Earth and has been found elsewhere in our solar system, for example in large deposits of ice at the north and south poles of Mars.

Planet HD 209458b also was the first planet outside the solar system found with an atmosphere and the first detected transiting planet. There are more than 200 known planets outside our solar system.

**** Mabel Abreu


Explosive chemicals- how dangerous are they?

Many people have a natural fear of chemicals that catch fire easily. In fact, the majority of us fear to enter in a lab where there are a majority of chemicals.

Flash Points Chemicals

Chemicals that are flammable will usually have a low flash point. What is this low flash point? It's the temperature at which the chemical will give out fumes sufficiently enough to catch fire when a lighted flame is brought near to it.

This means that a chemical having a lower flash point than room temperature will give out fumes capable of catching fire even though it is stored at normal room temperatures.

Thus, gasoline with flash point of -20 degree Centigrade will already be able to catch fire at normal room temperature if a light flame is present, while kerosene with flash point of 38 degree Centigrade will not burn when it is kept at a room temperature of 30 degree Centigrade.

Well, that's not totally correct either. In order to burn, three things must be present at the same time: fuel, oxygen and heat. When we talk about flash point, we are talking about the heat to generate sufficient gaseous fumes that can burn, but the chemical will not burn until a higher temperature is reached. That temperature is the ignition point.

Ignition Point

The ignition point can be reached if a lighted flame is brought near to the combustible fumes, or it can be from a sparking electrical contact or even from sparks produced from mechanical impact. Very often, it can even come from sparks generated by static electricity.

Even when all these conditions have been reached, fire will not start if there is not sufficient oxygen to support the combustion. This is a very important factor to consider especially when storing flammable chemicals.

Inert Gas Systems

On tanker ships, whenever crude oil or other flammable oil is pumped out, the space occupied by the oil must be replaced, otherwise, there will be a vacuum formed in the tank. This makes it impossible to pump the oil out further. To avoid atmospheric air from being sucked into the tank and creating an explosive mixture, inert gas is led into the tank at a slightly higher pressure than atmospheric.

This inert gas, containing mostly carbon dioxide and nitrogen, is generated from the burning of fuel in the steam boilers. This inert gas is pumped into the tank by means of blowers. The oxygen content in the exhaust gas must always be monitored. Usually it is around 5% and does not support combustion. To prevent corrosion and contamination of the oil, the exhaust gas is cleaned by passing them through a scrubber system. In this case, even though the tank may be nearly empty, the atmosphere above the chemical does not contain oxygen and there is no explosive mixture.

there are more different kinds of dangerous chemicals, feel free to stop by

Rodrigo Monsalve


Effectiveness of Sports Drinks

I found this to be quite interesting...hope you like it!!!!!!!!!!!!

Which Drink is Better?
What drink is best for getting and staying hydrated during exercise? Should you choose water? Are sports drinks best? What about juice or carbonated soft drinks? Coffee or tea? Beer?

The natural choice for hydration is water. It hydrates better than any other liquid, both before and during exercise. Water tends to be less expensive and more available than any other drink. You need to drink 4-6 ounces of water for every 15-20 minutes of exercise. That can add up to a lot of water! While some people prefer the taste of water over other drinks, most people find it relatively bland and will stop drinking water before becoming fully hydrated. Water is the best, but it only helps you if you drink it.

Sports Drinks

Sports drinks don't hydrate better than water, but you are more likely to drink larger volumes, which leads to better hydration.

The typical sweet-tart taste combination doesn't quench thirst, so you will keep drinking a sports drink long after water has lost its appeal. An attractive array of colors and flavors are available. You can get a carbohydrate boost from sports drinks, in addition to electrolytes which may be lost from perspiration, but these drinks tend to offer lower calories than juice or soft drinks.

Juice may be nutritious, but it isn't the best choice for hydration. The fructose, or fruit sugar, reduces the rate of water absorption so cells don't get hydrated very quickly. Juice is a food in its own right and it's uncommon for a person to drink sufficient quantities to keep hydrated. Juice has carbohydrates, vitamins, minerals, and electrolytes, but it isn't a great thirst quencher.

Carbonated Soft Drinks

When you get right down to it, the colas and uncolas of the world aren't good for the body. The acids used to carbonate and flavor these beverages will damage your teeth and may even weaken your bones. Soft drinks are devoid of any real nutritional content. Even so, they taste great! You are more likely to drink what you like, so if you love soft drinks then they might be a good way to hydrate. The carbohydrates will slow your absorption of water, but they will also provide a quick energy boost. In the long run, they aren't good for you, but if hydration is your goal, soft drinks aren't a bad choice. Avoid drinks with lots of sugar or caffeine, which will lessen the speed or degree of hydration.

Coffee and Tea

Coffee and tea can sabotage hydration. Both drinks act as diuretics, meaning they cause your kidneys to pull more water out of your bloodstream even as the digestive system is pulling water into your body. It's a two-steps-forward-one-step-back scenario. If you add milk or sugar, then you reduce the rate of water absorption even further. The bottom line? Save the latte for later.

Alcoholic Beverages

A beer might be great after the game, as long as you were the spectator and not the athlete. Alcohol dehydrates your body. Alcoholic beverages are better for hydration than, say, seawater, but that's about it.

The bottom line: Drink water for maximum hydration, but feel free to mix things up a bit to cater to your personal taste. You will drink more of what you like. In the end, the quantity of liquid is the biggest factor for getting and staying hydrated.

Mabel Abreu

Hair Color Chemistry

I found this interesting article describing the reactions that are involved when girls die their hair. According to the article, it is a result of a series of chemical reactions between the molecules in hair, pigments, as well as peroxide and ammonia, if present. 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. 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). People have been coloring their hair for thousands of years using plants and minerals. 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 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.

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. 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.


Mabel Abreu

When Every Day is Fry-Day

When Every Day is Fry-Day

A lot of frying goes on at food manufacturing businesses around the country. Potato chips, chicken strips, fish sticks, onion rings, French fries: the list goes on and on. This adds up to a lot of fried foods, as well as to a lot of frying oil needed for their manufacture.

The quantity of frying oil needed is huge, which makes the dilemma of knowing when to change the oil an economic concern. It’s also a health concern. Cooking oil degrades over time, especially when exposed to high heat; and it produces unsavory compounds that at best make your food taste bad and at worst could be harmful to your health. Change the oil too late and food quality suffers; however, change the oil before it is necessary, and resources are wasted.

Chemical tests can accurately determine the degree of oil deterioration, but have been impractical for many industries—the tests are time consuming, require designated lab space, and create chemical waste. In looking for alternatives, food scientists at the University of Nebraska–Lincoln developed a method that uses near-infrared spectroscopy, which takes a few minutes to determine the state of an oil sample accurately without the need for special lab space or waste disposal. The work is described in an article published in the February 2007 issue of Journal of Agricultural and Food Chemistry (2007, 55, 593–597).

Randy Wehling and Susan Cuppett, professors of food science and technology at the University of Nebraska–Lincoln, and doctoral student, Choo Lum Ng, collaborated on the project, which involved developing statistical models that relate spectral data to the extent of degradation in a soy-based oil.

To develop their models, the researchers first created a series of progressively degraded oil samples. They then analyzed each sample by using two methods typically used in gauging oil deterioration: one to determine quantities of polar materials and the other to measure free fatty acids. A near-infrared spectrum also was obtained for each sample.

These two parallel sets of data, one chemical and the other spectral, made it possible for the researchers to use statistical techniques to build several calibration models. Calibration models are mathematical algorithms that describe the relationship between the quantities of degraded oil products in any sample and the amount of infrared light absorbed by that sample.

Once their calibration models were built, the team checked their validity by creating new sets of degraded oils and determining how well each model predicted degradation within these samples. Chemical testing of the samples provided bona fide measures of degradation that could be compared with values predicted by the calibration models.

The results verified that several of the models could successfully be used to determine oil deterioration.

However, because oil doesn’t sit alone in commercial frying vats, the researchers needed to determine how the presence of food in oil might affect their method. In a follow-up study, Wehling et al. repeated their model-building experiments using three cooking scenarios: one that tested oil used to make French fries, another to make tortilla chips, and a third to make chicken nuggets.

The results indicate that the team’s model-building efforts can adapt to real-life situations. “For the oil that we were using, we were able to develop a single model that could accurately predict its level of degradation no matter which of those three foods had been involved,” Wehling says. He and his colleagues presented these results a few weeks ago at the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy.

Wehling expects that food production industries will be interested in the technique. Since no hazardous chemical reagents are used, there is no need for separate handling and disposal of chemical waste, so that an instrument can be set up next to a production line in a plant environment. “The goal ultimately would be to see if we could develop a small, portable hand-held type of instrument,” he says.

Wehling also notes that if such an instrument could be made to be inexpensive enough, it would be suitable for use in smaller food service establishments such as schools and restaurants.

Yasiel Hernandez

Natural Copy Cat

According to this article about Natural copy cat, green plants extract carbon dioxide gas from the air and turn it into sugar molecules using sunlight and give off oxygen. Chemists, on the other hand, have yet to find an efficient method for converting carbon dioxide into materials that might be useful as fuels or in manufacturing. Almost all our efforts rely on complex reaction schemes to produce the starting materials and then are so inefficient that the end product costs far more to produce, in terms of energy and economics, it is worthless. Chemical activation of carbon dioxide involves splitting, or cleaving, it in a chemical reaction, the researchers explains. Splitting the CO2 basically releases carbon monoxide, a chemically reactive form, and oxygen free radicals that can then react with other molecules to produce more complex and potentially useful products. This cleavage process is one of the biggest challenges facing synthetic chemistry today. The problem with attempting to activate carbon dioxide is that the double bonds between the central carbon atom and its two flanking oxygen atoms are very strong and stable. A lot of energy is needed to pull them apart and cleave the molecule. Plants have had millions of years to evolve the most effective way to use sunlight to activate carbon dioxide, but chemists have only had a few decades and, until recently, have expended a lot of energy developing special metal catalysts, which can cleave carbon dioxide, but are notoriously inefficient.

Rodrigo Monsalve