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
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
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.
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.
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.'
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.
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.
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: http://www.sciencedaily.com/
Posted: Vivian Coolen
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.
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.
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.
Here's the link to the article:
Copyright 2007 by United Press International. All Rights Reserved.
Extra Information: http://www.sciencedaily.com
Posted by Vivian Coolen
Here's the link:
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.
'PART OF PUZZLE'
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
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.
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 http://www.buzzle.com/articles/explosive-chemicals-dangerous.html
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 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.
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.
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.
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.
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.
You all know how difficult it can be to seperate certain chemical bonds. Recently, scientists have been able to mechanically force chemical bonds of a molecule called benzocyclobutene (BCB) to break apart. Doing this mechanically is better than the previous method of doing it chemically using light, heat, or electricity.
Now, the true significance of this new discovery is that seperating BCB mechanically allows it to reform into two identical shapes, meaning that polymeric substances made from BCB can be self-healing. Think about it, this means that scientists can make the substance into artificial bones that automatically repair any cracks or breaks they may encounter and actually thicken and harden, mimicking how actual living bone works.
Like any new discovery, perfecting this substance is still years away, but it is an important breakthrough nonetheless. Okay, just wanted to share that with you guys, take care.
For a more in-depth look at this new discovery, you can check out:
I found this interesting article, just in case for you to know, and do not make any dangerous mixtures at home! Since some of the common chemicals found in your home shouldn't be mixed together. It's one thing to say "don't mix bleach with ammonia", but it's not always easy to know what products contain these two chemicals. Here's are some products you may have around the home that shouldn't be combined.
Bleach with VinegarVinegar is a type of acid. Toxic chlorine vapor is produced. Don't mix chlorine bleach with any acid.
Bleach with AmmoniaToxic, potentially lethal vapors are produced.
Different Brands of One Type of ProductDon't mix different cleaners together. They may react violently, produce toxins, or become ineffective.
Highly Alkaline Products with Highly Acidic ProductsAcids and bases (alkalis) can react violently, presenting a splash hazard.
Acids and bases are caustic and may cause chemical burns.
Certain Disinfectants with DetegentsDon't mix disinfectants with 'quaternary ammonia' listed as an ingedient with a detergent. The effectiveness of the disinfectant may be neutralized.
Chlorine bleach is sometimes called “sodium hypochlorite” or “hypochlorite.” You will encounter it in chlorine bleach, automatic dishwashing detergents, chlorinated disinfectants and cleaners, chlorinated scouring powder, mildew removers, and toilet bowl cleaners. Do not mix products together. Do not mix them with ammonia or vinegar.
With this, just remember to read the labels of products in your home and following instructions for proper use. Many containers will state the most common dangers from interaction with other products.
So, after this, just try to have in mind all the instructions mentioned above!!
Nohora C. Duque
Coca-Cola® products range in pH from 2.5 - 4.2. Coca-Cola Classic® is the most acidic at 2.5. Other food liquids that might contain Carbonic acid could include lemon juice, vinegar, salad dressings, and pickle solutions.
We also discovered that the human stomach is pretty capable of regulating its own pH. If things do get out of control, it is not usually the hydrochloric acid itself that is dangerous. Digestive enzymes work best at their optimum pH. One enzyme in particular, pepsin, works a little too well if the stomach is allowed to approach pepsin's optimum pH of 1.5 - 1.6. Excessive enzyme activity (in effect, digesting the wrong meat) is the real reason that excess stomach acid leads to gastric ulcers—not stomach acid itself.
A curious note found at the end of the article is: Another fun experiment is to drop an unopened can of Diet Coke® and an unopened can of Coca-Cola Classic® in a tank, bowl or bucket of water. Although both cans contain the same amount of liquid, one floats and the other sinks because of the difference in density between sugar and aspartame, the sweetener used in Diet Coke®.
I’ve heard many myths that Coca-Cola is really bad for your stomach. This article covers pretty much this explanation answering the student’s question.Iif you may want to visit the web site, here is the link http://www.madsci.org/posts/archives/oct98/909181221.Ch.r.html
Hope you found it interesting!
Nohora C. Duque
None of the strong acids traditionally listed in a chemistry text holds the title of the world’s Strongest Acid. It used to be Fluorosulfuric Acid HFSO3, but the Caborane are millions of times stronger than the HFSO3, and also is more powerful than concentrated sulfuric acid.
The carborane acids are also incredible proton donors, but they are not corrosive. Corrosiveness is related to negatively-charged part of the acid. Hydrofluoric acid HF, it’s an example of a corrosive because it dissolves glass. But it’s not considered to be strong acid because it does not completely dissociate in water.
If you want to know more guys please visit http://chemistry.about.com/od/chemistryfaqs/f/strongestacid.htm
I read this article about how advancements in chemistry are allowing scientists to make synthetic diamonds that look just like mined diamonds. Synthetic diamonds are chemically and physically true diamonds, and they cost only about a third as much as the ones that are naturally found. These synthetics have been around for a while, but have only recently been made to sizes of more than one carat. Synthetic diamonds start out as tiny diamond "seeds" which chemists then grow.
Scientists are doing even more with diamonds; they can turn either natural or synthetic diamonds into different colors by introducing chemicals into the stone. For example, diamonds can be turned blue by carefully infusing them with boron.
Not only are these advancements interesting, but they may someday reduce the mining of natural diamonds, which is a harsh and dangeroud task.
Here's the article if you want to know more.
Here it is:
Chemical Names of Common Substances
Alternate Words for Familiar Materials
Chemical or scientific names are used to give an accurate description of a substance's composition. Even so, you rarely ask someone to pass the sodium chloride at the dinner table. It's important to remember that common names are inaccurate and vary from one place and time to another. Therefore, don't assume that you know the chemical composition of a substance based on its common name. This is a list of archaic names and common names for chemicals, with their modern or IUPAC equivalent name.
dimethyl ketone; 2-propanone (usually known as acetone)
acid potassium sulfate
acid of sugar
aluminum potassium sulfate
antimony red (vermillion)
aqueous solution of ammonium hydroxide
aromatic spirit of ammonia
ammonia in alcohol
mineral form of basic copper carbonate
banana oil (artificial)
bicarbonate of soda
sodium hydrogen carbonate or sodium bicarbonate
bichloride of mercury
crude form of sodium carbonate
black copper oxide
chlorinated lime; calcium hypochlorite
copper sulfate (crystals)
copper sulfate (crystals)
crude calcium phosphate
crude animal charcoal
sodium borate; sodium tetraborate
basic copper carbonate
anhydrous potassium aluminum sulfate
aqueous sodium chloride solution
butter of antimony
butter of tin
anhydrous stannic chloride
butter of zinc
mercury chloride; mercurous chloride
carbonic acid gas
basic lead chromate
chloride of soda
chloride of lime
chromic potassium sulfate
lead (VI) chromate
mercury (II) chloride
corundum (ruby, sapphire)
chiefly aluminum oxide
cream of tartar
impure aluminum oxide
anhydride iron (III) chloride
natural calcium fluoride
flowers of sulfur
'flowers of' any metal
oxide of the metal
aqueous formaldehyde solution
natural magnesium silicate
basic copper acetate
natural lead sulfide
basic copper carbonate
ferrous sulfate crystals
natural calcium sulfate
boiled linseed oil
sodium thiosulfate solution
crude form of carbon; charcoal
aqueous solution of calcium hydroxide
ammonium hydroxide solution
liver of sulfur
lye or soda lye
mainly calcium carbonate
mercury oxide, black
milk of lime
milk of magnesium
milk of sulfur
"muriate" of a metal
chloride of the metal
fuming sulfuric acid
oil of mars
deliquescent anhydrous iron (III) chloride
oil of vitriol
oil of wintergreen (artificial)
powdered calcium carbonate
pear oil (artificial)
plaster of Paris
aluminum acetate solution
red prussiate of potash
red prussiate of soda
potassium sodium tartrate
salt of lemon
salt of tartar
dilute sulfuric acid
spirit of hartshorn
ammonium hydroxide solution
spirit of salt
spirit of wine
spirits of nitrous ether
sugar of lead
talc or talcum
natural sodium carbonate
basic copper acetate
impure dilute acetic acid
basic lead carbonate
zinc sulfate crystals
yellow prussiate of potash
yellow prussiate of soda
The Liverpool scientists said they created a porous crystal that has "walls" of atoms and cavities acting as containers for molecules. They used that crystal to accommodate a set of molecules taking part in a chemical reaction, similar to reactions by enzymes and proteins that regulate and keep alive living systems. The crystal was put into a powerful X-ray diffraction machine to allow scientists to precisely pinpoint the positions of individual atoms, providing snapshots of their movement both before and after the reaction. The researchers say that marked the first time the positions of atoms both at the beginning and the end of a chemical process have been seen.
The research appears in the latest issue of Science magazine.
Posted by Vivian Coolen
I found this pretty interesting article on gasoline. I'm posting it because I think it's important for everyone to a little something about the type of fluids that are being used for their automobile. I hope you learn something from it :-)
2.) Elemental carbon can take the form of one of the hardest substances (diamond) or one of the softest (graphite).
3.) Carbon is the basis for organic chemistry, as it occurs in all living organisms.
4.) Carbon is made in the interiors of stars, though it was not produced in the Big Bang.
5.) Carbon compounds have limitless uses. In its elemental form, diamond is a gemstone and used for drilling/cutting; graphite is used in pencils, as a lubricant, and to protect against rust; while charcoal is used to remove toxins, tastes, and odors.
6.) Carbon has the highest melting/sublimation point of the elements. The melting point of diamond is ~3550°C, with the sublimation point of carbon around 3800°C.
7.) Pure carbon exists free in nature and has been known since prehistoric time.
8.) The origin of the name 'carbon' comes from the Latin word carbo, for charcoal. The German and French words for charcoal are similar.
9.) Pure carbon is considered non-toxic, although inhalation of fine particles, such as soot, can damage lung tissue.
10.) Carbon is the fourth most abundant element in the universe (hydrogen, helium, and oxygen are found in higher amounts, by mass).
i just think it was necessary that we all know get some information about this particular element carbon.
Analyzing human blood for a very low virus concentration or a sample of water for a bioterrorism agent has always been a time-consuming and difficult process. Researchers at the Georgia Institute of Technology and Emory University have developed an easier and faster method to detect these types of target molecules in liquid samples using highly porous, micron-sized, silica beads. The researchers developed a technique to simultaneously or sequentially add optical and magnetic nanoparticles into the beads. Adding magnetic nanoparticles allows the use of a magnetic field to attract and easily remove the beads from a liquid sample. The beads are mixed in a liquid such as urine. Viruses, proteins or other biomarkers are captured on the bead surface. After the beads are removed from the liquid, optical imaging is used to determine the concentration of a specific protein or virus in the liquid sample based on the number of proteins or viruses attached to the surface of the beads. For further research,
Okie, Vivian Coolen
Research has led to discoveries on what actually causes skin to tan or, to be more precise, what keeps light-skinned people from tanning. Previously, it was believed that UV radiation directly affected melanocyte cells, which are cells in the epidermis that produce pigment known as melanin. Actually, UV rays affect nearby cells called keratinocytes and those can affect the melanocyte cells through receptors that link the two. However, light-skinned people have faulty receptors and that keeps them from tanning.
This is interesting because now that they know more about what causes the skin to tan, they have also found a possible way to allow tanning in light-skinned people. In experiments with mice, scientists have been able to use a plant extract called forskolin to bypass the faulty receptors causing pigmentation.
The true significance behind this is that if scientists succeed in being able to give light-skinned people a natural tan, that will reduce the number of people that develop skin cancer since people with light skin are at higher risk. However, we won't see any of this for years since it's currently only been tested on mice meaning that much of the process is still only theoretical. It's a good start though.
Here's the link which goes further in depth if anyone's interested.
Unless you’ve avoided cooking, you probably cut up an onion and experienced the burning and tearing you get from the vapors. When you cut an onion, you break cells, releasing their contents. Amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to mix with the sulfenic acids to produce propanethiol S-oxide, a volatile sulfur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears to wash the irritant away.
I know most of you guys know this, but I wanted to share this article anyways…if you want to know more go to this website
Along with the previews posted article, I found this other interesting article. It is about the reason why bananas, apples, pears and potatoes turn brown after a certain time of being cut.
This fruits contain contain an enzyme (called polyphenol oxidase or tyrosinase) that reacts with oxygen and iron-containing phenols that are also found in the apple. The oxidation reaction basically forms a sort of rust on the surface of the fruit. You see the browning when the fruit is cut or bruised because these actions damage the cells in the fruit, allowing oxygen in the air to react with the enzyme and other chemicals.
This reaction that takes place could be slowed or prevented by inactivating the enzyme with heat (cooking), reducing the pH on the surface of the fruit (by adding lemon juice or another acid), reducing the amount of available oxygen (by putting cut fruit under water or vacuum packing it), or by adding certain preservative chemicals (like sulfur dioxide).
I found this interesting article that explains the truth behind Magic Candles used for birthday cakes! When you blow out a normal candle, you will see a thin ribbon of smoke rise up from the wick; while trick candles have fine flakes of the metal magnesium. Since it doesn't take too much heat to make magesium ignite (800° F or 430° C), but the magnesium itself burns white-hot and readily ignites the paraffin vapor, capable of being ignited by the relatively low temperature of the hot wick ember.
As I read this article, it came to my mind the last experiment that we did in our chemistri Lab class, since we also worked with Magnesium, remmembering it's bright appearance when it is heatted.
If you want to read more about this interesting article here is the link!
Nohora C. Duque
bubble logic that merges chemistry with computation technology. It relates how a new technology has been developed and it has replaced traditional electrical current in our computer chips to ones that work with the flow of tiny bubbles. Interesting isn't it?
The link is http://www.physorg.com/news90167885.html
I found a very interesting article, it says that “our brain requires a tenth of a calorie per minute”. The brain communicates with other neurons through body tissues. These neurons produce chemicals called “Transmitters” and in order to have neurotransmitters, every neuron removes 75% of glucose (available calories) and 20% of oxygen blood.
Well, this was like a short introduction for you guys, if you want to know more go check the website, they have pretty good articles also.
I found this interesting article, which is related to a question that was brought up by Francia in class, of Can drinking too much water lead to water intoxication? and in some how it is also related with solutes and dilution (seein in ch. 4).
It explains that when too much water enters the body's cells, the tissues swell with the excess fluid. Your cells maintain a specific concentration gradient, so excess water outside the cells (the serum) draws sodium from within the cells out into the serum in an attempt to re-establish the necessary concentration. As more water accumulates, the serum sodium concentration drops -- a condition known as hyponatremia.
The other way cells try to regain the electrolyte balance is for water outside the cells to rush into the cells via osmosis. The movement of water across a semipermeable membrane from higher to lower concentration is called osmosis. Although electrolytes are more concentrated inside the cells than outside, the water outside the cells is 'more concentrated' or 'less dilute' since it contains fewer electrolytes. Both electrolytes and water move across the cell membrane in an effort to balance concentration. Theoretically, cells could swell to the point of bursting.
BUt the truth is that , most adults need about three quarts of fluid each day. Much of that water comes from food, so 8-12 eight ounce glasses a day is a common recommended intake. You may need more water if the weather is very warm or very dry, if you are exercising, or if you are taking certain medications. The bottom line is this: it's possible to drink too much water, but unless you are running a marathon or an infant, water intoxication is a very uncommon condition.
If you want to read the complete article, this is the link http://chemistry.about.com/cs/5/f/blwaterintox.htm, Hope you enjoy it!!
Nohora C. Duque
I found this article that I thought was interesting. You've probably all heard of carbon monoxide detectors, but this gives you important details about them. I hope it benefits someone! :-)
Found another article, this is about the making of plastics. It states that most industrial palstics are made of oil. salt, air and water. Weird huh? It basically takes a long process of extracting, distiltion, cracking and boiling to make the magnificent wonder of plastic. What would we do without plastic bags, covers and other useful gadgets of plastics. To read the Article follow the link!! http://www.buzzle.com/editorials/5-6-2004-53813.asp.
Well um I was searching on-line looking for chemistry articles and I found this very interesting one that basically states that scientists in Italy have managed to develop this form of plastic packaging that is able to sensor food contamination and then displays a certain type of dye. By seeing this dye it alerts the person to realize that the food is no good and therefore it is disposed of. But what sounds really good for the environment is that the plastic packaging that it comes in is biodegradable- meaning that is can be broken down by micro-organisms found in soil or even sea water. Unlike billions of plastic wrappings that are produced and in the end are not disposed of properly without harming the environment.
If you guys want to read the artilce just copy and paste the link below.
Title- Intelligent Wrappers
by:James Mitchell Crow
Hope you Guys found it interesting!!