In the recent years, Various interesting research programmes have been conducted in universities and other research institutes to find out phytochemicals that are present in specific plants.
Phytochemistry is an areas that needs not be underestimated in the development of medicinal structures today in Africa and the world entirely. Being rich in various plant species, Africa has a very big potential to stand out independently in the field of medicinal research that can undoubtedly be successful looking at the expartise that it already has in different traditional ans university institutions.
The benefits of the studies are not a point to argue about particularly for Africa. Africa will lessen the burden of importing medicines from elsewhere when it has all the botanic resources required. What needs to be done is to ammasse the rest of the latest technological equipment that others are using elsewhere to help in the effectiveness of the business.
It is a matter of urgency for African govenments to consider putting in full political will in the field of medicinal research to see it being relieved of any handicaps in medicinal development.
Phytochemicals are what may bring a great revolution in the field of medicinal research.
Look out for more on phytochemical analysis.....
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More from Dr. Anne marie Helmenstine
Make Biodiesel - Instructions for Making Biodiesel from Vegetable Oil
Save Money Making Your Own Biodiesel
By Anne Marie Helmenstine, Ph.D., About.com
It's easy and cost-effective to make your own biodiesel.
Biodiesel Engine Biodiesel Plant How to Make Biodiesel Biodiesel Production Making Biodiesel
Biodiesel is a diesel fuel that is made by reacting vegetable oil (cooking oil) with other common chemicals. Biodiesel may be used in any diesel automotive engine in its pure form or blended with petroleum-based diesel. No modifications are required, and the result is a less-expensive, renewable, clean-burning fuel. Here's how to make biodiesel from fresh oil. You can also make biodiesel from waste cooking oil, but that is a little more involved, so let's start with the basics.
Materials for Making Biodiesel
· 1 liter of new vegetable oil (e.g, canola oil, corn oil, soybean oil)
· 3.5 grams (0.12 oz.) sodium hydroxide (also known as lye). Sodium hydroxide is used for some drain cleaners, such as Red Devil™ drain cleaner. The label should state that the product contains sodium hydroxide (not calcium hypochlorite, which is found in many other drain cleaners)
· 200 milliliters (6.8 fl. oz.) of methanol (methyl alcohol). Heet™ fuel treatment is methanol. Be sure the label says the product contains methanol (Isoheet™, for example, contains isopropyl alcohol and won't work).
· blender with a low speed option. The pitcher for the blender is to be used only for making biodiesel. You want to use one made from glass, not plastic, since the methanol you will use can react with plastic.
· digital scale [to accurately measure 3.5 grams (0.12 oz.)]
· glass container marked for 200 milliliters (6.8 fl. oz.). If you don't have a beaker, measure the volume using a measuring cup, pour it into a glass jar, then mark the fill-line on the outside of the jar.
· glass or plastic container that is marked for 1 liter (1.1 quart)
· wide mouth glass or plastic container that will hold at least 1.5 liters (2-quart pitcher works well)
· safety glasses, gloves, and probably an apron. You do not want to get sodium hydroxide or methanol on your skin, nor do you want to breathe the vapors from either chemical. Both chemicals are toxic. Please read the warning labels on the containers for these products! Methanol is readily absorbed through your skin, so do not get it on your hands. Sodium hydroxide is caustic and will give you a chemical burn. Prepare your biodiesel in a well-ventilated area. If you spill either chemical on your skin, rinse it off immediately with water.
Let's Make Biodiesel!
1. You want to prepare the biodiesel in a room-temperature (70° F) or warmer room since the chemical reaction will not proceed to completion if the temperature is too low.
2. If you haven't already, label all your containers as 'Toxic - Only Use for Making Biodiesel', since you don't want anyone drinking your supplies and you don't want to use the glassware for food again.
3. Pour 200 ml methanol (Heet) into the glass blender pitcher.
4. Turn the blender on its lowest setting and slowly add 3.5 g sodium hydroxide (lye). This reaction produces sodium methoxide, which must be used right away or else it loses its effectiveness. (Like sodium hydroxide, it can be stored away from air/moisture, but that might not be practical for a home setup.)
5. Mix the methanol and sodium hydroxide until the sodium hydroxide has completely dissolved (about 2 minutes), then add 1 liter of vegetable oil to this mixture.
6. Continue blending this mixture (on low speed) for 20-30 minutes.
7. Pour the mixture into a wide-mouth jar. You will see the liquid start to separate out into layers. The bottom layer will be glycerin. The top layer is the biodiesel.
8. Allow at least a couple of hours for the mixture to fully separate. You want to keep the top layer as your biodiesel fuel. If you like, you can keep the glycerin for other projects. You can either carefully pour off the biodiesel or use a pump or baster to pull the biodiesel off of the glycerin.
Using Biodiesel
Normally you can use pure biodiesel or a mixture of biodiesel and petroleum diesel as a fuel in any unmodified diesel engine. There are two situations in which you definitely should mix biodiesel with petroleum-based diesel.
· If you are going to be running the engine at a temperature lower than 55° F (13° C), you should mix biodiesel with petroleum diesel. A 50:50 mixture will work for cold weather. Pure biodiesel will thicken and cloud at 55° F, which could clog your fuel line and stop your engine. Pure petroleum diesel, in contrast, has a cloud point of -10° F (-24° C). The colder your conditions, the higher percentage of petroleum diesel you will want to use. Above 55° F you can use pure biodiesel without any problem. Both types of diesel return to normal as soon as the temperature warms above their cloud point.
· You will want to use a mixture of 20% biodiesel with 80% petroleum diesel (called B20) if your engine has natural rubber seals or hoses. Pure biodiesel can degrade natural rubber, though B20 tends not to cause problems. If you have an older engine (which is where natural rubber parts are found), you could replace the rubber with polymer parts and run pure biodiesel.
Biodiesel Stability & Shelf Life
You probably don't stop to think about it, but all fuels have a shelf life that depends on their chemical composition and storage conditions. The chemical stability of biodiesel depends on the oil from which it was derived. Biodiesel from oils that naturally contain the antioxidant tocopherol or vitamin E (e.g., rapeseed oil) remain usable longer than biodiesel from other types of vegetable oils. According to at least one source stability is noticeably diminished after 10 days and the fuel may be unusable after 2 months. Temperature also affects fuel stability in that excessive temperatures may denature the fuel.
What Is the Difference Between a Scientist and an Engineer?
By Anne Marie Helmenstine, Ph.D., About.com
Chemical engineers supervise the central pumping station at the Yukos Oil and Gas company in Nefteyugansk, Siberia.
Links
Chemical Software FreeMolecular Builder and Property Estimation Neural Networkwww.bestsystems.co.jp
Information SecurityYour Flexible Route To University! Sign Up At University of London Nowwww.LondonExternal.ac.uk
Virtual Chem LabFun Simulations & Guided Lessons Register & Get Next 6 Months Free.www.VirtLab.com
if(zs
Question: What Is the Difference Between a Scientist and an Engineer?
Scientist versus engineer... are they the same? Different? Here's a look at the definitions of scientist and engineer and the difference between a scientist and engineer.
Answer: A scientist is a person who has scientific training or who works in the sciences. An engineer is someone who is trained as an engineer. So, to my way of thinking, the practical difference lies in the educational degree and the description of the task being performed by the scientist or engineer. On a more philosophical level, scientists tend to explore the natural world and discover new knowledge about the universe and how it works.
Engineers apply that knowledge to solve practical problems, often with an eye toward optimizing cost, efficiency, or some other parameters.
There is considerable overlap between science and engineering, so you will find scientists who design and construct equipment and engineers who make important scientific discoveries. Information theory was founded by Claude Shannon, a theoretical engineer. Peter Debye won the Nobel Prize in Chemistry with a degree in electrical engineering and a doctorate in physics.
Do you feel there are important distinctions between scientists and engineers? You're invited to define the difference.
Why is Stainless Steel Stainless?
What It Is and How It Works!
By Anne Marie Helmenstine, Ph.D., About.com
What Is Stainless Steel and Why Is it Stainless?
In 1913, English metallurgist Harry Brearly, working on a project to improve rifle barrels, accidentally discovered that adding chromium to low carbon steel gives it stain resistance.
In addition to iron, carbon, and chromium, modern stainless steel may also contain other elements, such as nickel, niobium, molybdenum, and titanium. Nickel, molybdenum, niobium, and chromium enhance the corrosion resistance of stainless steel. It is the addition of a minimum of 12% chromium to the steel that makes it resist rust, or stain 'less' than other types of steel.
The chromium in the steel combines with oxygen in the atmosphere to form a thin, invisible layer of chrome-containing oxide, called the passive film. The sizes of chromium atoms and their oxides are similar, so they pack neatly together on the surface of the metal, forming a stable layer only a few atoms thick. If the metal is cut or scratched and the passive film is disrupted, more oxide will quickly form and recover the exposed surface, protecting it from oxidative corrosion. (Iron, on the other hand, rusts quickly because atomic iron is much smaller than its oxide, so the oxide forms a loose rather than tightly-packed layer and flakes away.)
The passive film requires oxygen to self-repair, so stainless steels have poor corrosion resistance in low-oxygen and poor circulation environments. In seawater, chlorides from the salt will attack and destroy the passive film more quickly than it can be repaired in a low oxygen environment.
Types of Stainless Steel
The three main types of stainless steels are austenitic, ferritic, and martensitic. These three types of steels are identified by their microstructure or predominant crystal phase.
Austenitic: Austenitic steels have austenite as their primary phase (face centered cubic crystal). These are alloys containing chromium and nickel (sometimes manganese and nitrogen), structured around the Type 302 composition of iron, 18% chromium, and 8% nickel. Austenitic steels are not hardenable by heat treatment.
The most familiar stainless steel is probably Type 304, sometimes called T304 or simply 304. Type 304 surgical stainless steel is an austenitic steel containing 18-20% chromium and 8-10% nickel.
Ferritic: Ferritic steels have ferrite (body centered cubic crystal) as their main phase. These steels contain iron and chromium, based on the Type 430 composition of 17% chromium. Ferritic steel is less ductile than austenitic steel and is not hardenable by heat treatment.
Martensitic: The characteristic orthorhombic martensite microstructure was first observed by German microscopist Adolf Martens around 1890. Martensitic steels are low carbon steels built around the Type 410 composition of iron, 12% chromium, and 0.12% carbon. They may be tempered and hardened. Martensite gives steel great hardness, but it also reduces its toughness and makes it brittle, so few steels are fully hardened.
There are also other grades of stainless steels, such as precipitation-hardened, duplex, and cast stainless steels. Stainless steel can be produced in a variety of finishes and textures and can be tinted over a broad spectrum of colors.
Suggested Reading
Metals & AlloysMetals QuizCopper Plate an Ornament
w('New posts to the Chemistry forums:Nernst Equation Worked ProblemChemistry Help PLEASE!!!electrochemistry help please')
Save Money Making Your Own Biodiesel
By Anne Marie Helmenstine, Ph.D., About.com
It's easy and cost-effective to make your own biodiesel.
Biodiesel Engine Biodiesel Plant How to Make Biodiesel Biodiesel Production Making Biodiesel
Biodiesel is a diesel fuel that is made by reacting vegetable oil (cooking oil) with other common chemicals. Biodiesel may be used in any diesel automotive engine in its pure form or blended with petroleum-based diesel. No modifications are required, and the result is a less-expensive, renewable, clean-burning fuel. Here's how to make biodiesel from fresh oil. You can also make biodiesel from waste cooking oil, but that is a little more involved, so let's start with the basics.
Materials for Making Biodiesel
· 1 liter of new vegetable oil (e.g, canola oil, corn oil, soybean oil)
· 3.5 grams (0.12 oz.) sodium hydroxide (also known as lye). Sodium hydroxide is used for some drain cleaners, such as Red Devil™ drain cleaner. The label should state that the product contains sodium hydroxide (not calcium hypochlorite, which is found in many other drain cleaners)
· 200 milliliters (6.8 fl. oz.) of methanol (methyl alcohol). Heet™ fuel treatment is methanol. Be sure the label says the product contains methanol (Isoheet™, for example, contains isopropyl alcohol and won't work).
· blender with a low speed option. The pitcher for the blender is to be used only for making biodiesel. You want to use one made from glass, not plastic, since the methanol you will use can react with plastic.
· digital scale [to accurately measure 3.5 grams (0.12 oz.)]
· glass container marked for 200 milliliters (6.8 fl. oz.). If you don't have a beaker, measure the volume using a measuring cup, pour it into a glass jar, then mark the fill-line on the outside of the jar.
· glass or plastic container that is marked for 1 liter (1.1 quart)
· wide mouth glass or plastic container that will hold at least 1.5 liters (2-quart pitcher works well)
· safety glasses, gloves, and probably an apron. You do not want to get sodium hydroxide or methanol on your skin, nor do you want to breathe the vapors from either chemical. Both chemicals are toxic. Please read the warning labels on the containers for these products! Methanol is readily absorbed through your skin, so do not get it on your hands. Sodium hydroxide is caustic and will give you a chemical burn. Prepare your biodiesel in a well-ventilated area. If you spill either chemical on your skin, rinse it off immediately with water.
Let's Make Biodiesel!
1. You want to prepare the biodiesel in a room-temperature (70° F) or warmer room since the chemical reaction will not proceed to completion if the temperature is too low.
2. If you haven't already, label all your containers as 'Toxic - Only Use for Making Biodiesel', since you don't want anyone drinking your supplies and you don't want to use the glassware for food again.
3. Pour 200 ml methanol (Heet) into the glass blender pitcher.
4. Turn the blender on its lowest setting and slowly add 3.5 g sodium hydroxide (lye). This reaction produces sodium methoxide, which must be used right away or else it loses its effectiveness. (Like sodium hydroxide, it can be stored away from air/moisture, but that might not be practical for a home setup.)
5. Mix the methanol and sodium hydroxide until the sodium hydroxide has completely dissolved (about 2 minutes), then add 1 liter of vegetable oil to this mixture.
6. Continue blending this mixture (on low speed) for 20-30 minutes.
7. Pour the mixture into a wide-mouth jar. You will see the liquid start to separate out into layers. The bottom layer will be glycerin. The top layer is the biodiesel.
8. Allow at least a couple of hours for the mixture to fully separate. You want to keep the top layer as your biodiesel fuel. If you like, you can keep the glycerin for other projects. You can either carefully pour off the biodiesel or use a pump or baster to pull the biodiesel off of the glycerin.
Using Biodiesel
Normally you can use pure biodiesel or a mixture of biodiesel and petroleum diesel as a fuel in any unmodified diesel engine. There are two situations in which you definitely should mix biodiesel with petroleum-based diesel.
· If you are going to be running the engine at a temperature lower than 55° F (13° C), you should mix biodiesel with petroleum diesel. A 50:50 mixture will work for cold weather. Pure biodiesel will thicken and cloud at 55° F, which could clog your fuel line and stop your engine. Pure petroleum diesel, in contrast, has a cloud point of -10° F (-24° C). The colder your conditions, the higher percentage of petroleum diesel you will want to use. Above 55° F you can use pure biodiesel without any problem. Both types of diesel return to normal as soon as the temperature warms above their cloud point.
· You will want to use a mixture of 20% biodiesel with 80% petroleum diesel (called B20) if your engine has natural rubber seals or hoses. Pure biodiesel can degrade natural rubber, though B20 tends not to cause problems. If you have an older engine (which is where natural rubber parts are found), you could replace the rubber with polymer parts and run pure biodiesel.
Biodiesel Stability & Shelf Life
You probably don't stop to think about it, but all fuels have a shelf life that depends on their chemical composition and storage conditions. The chemical stability of biodiesel depends on the oil from which it was derived. Biodiesel from oils that naturally contain the antioxidant tocopherol or vitamin E (e.g., rapeseed oil) remain usable longer than biodiesel from other types of vegetable oils. According to at least one source stability is noticeably diminished after 10 days and the fuel may be unusable after 2 months. Temperature also affects fuel stability in that excessive temperatures may denature the fuel.
What Is the Difference Between a Scientist and an Engineer?
By Anne Marie Helmenstine, Ph.D., About.com
Chemical engineers supervise the central pumping station at the Yukos Oil and Gas company in Nefteyugansk, Siberia.
Links
Chemical Software FreeMolecular Builder and Property Estimation Neural Networkwww.bestsystems.co.jp
Information SecurityYour Flexible Route To University! Sign Up At University of London Nowwww.LondonExternal.ac.uk
Virtual Chem LabFun Simulations & Guided Lessons Register & Get Next 6 Months Free.www.VirtLab.com
if(zs
Question: What Is the Difference Between a Scientist and an Engineer?
Scientist versus engineer... are they the same? Different? Here's a look at the definitions of scientist and engineer and the difference between a scientist and engineer.
Answer: A scientist is a person who has scientific training or who works in the sciences. An engineer is someone who is trained as an engineer. So, to my way of thinking, the practical difference lies in the educational degree and the description of the task being performed by the scientist or engineer. On a more philosophical level, scientists tend to explore the natural world and discover new knowledge about the universe and how it works.
Engineers apply that knowledge to solve practical problems, often with an eye toward optimizing cost, efficiency, or some other parameters.
There is considerable overlap between science and engineering, so you will find scientists who design and construct equipment and engineers who make important scientific discoveries. Information theory was founded by Claude Shannon, a theoretical engineer. Peter Debye won the Nobel Prize in Chemistry with a degree in electrical engineering and a doctorate in physics.
Do you feel there are important distinctions between scientists and engineers? You're invited to define the difference.
Why is Stainless Steel Stainless?
What It Is and How It Works!
By Anne Marie Helmenstine, Ph.D., About.com
What Is Stainless Steel and Why Is it Stainless?
In 1913, English metallurgist Harry Brearly, working on a project to improve rifle barrels, accidentally discovered that adding chromium to low carbon steel gives it stain resistance.
In addition to iron, carbon, and chromium, modern stainless steel may also contain other elements, such as nickel, niobium, molybdenum, and titanium. Nickel, molybdenum, niobium, and chromium enhance the corrosion resistance of stainless steel. It is the addition of a minimum of 12% chromium to the steel that makes it resist rust, or stain 'less' than other types of steel.
The chromium in the steel combines with oxygen in the atmosphere to form a thin, invisible layer of chrome-containing oxide, called the passive film. The sizes of chromium atoms and their oxides are similar, so they pack neatly together on the surface of the metal, forming a stable layer only a few atoms thick. If the metal is cut or scratched and the passive film is disrupted, more oxide will quickly form and recover the exposed surface, protecting it from oxidative corrosion. (Iron, on the other hand, rusts quickly because atomic iron is much smaller than its oxide, so the oxide forms a loose rather than tightly-packed layer and flakes away.)
The passive film requires oxygen to self-repair, so stainless steels have poor corrosion resistance in low-oxygen and poor circulation environments. In seawater, chlorides from the salt will attack and destroy the passive film more quickly than it can be repaired in a low oxygen environment.
Types of Stainless Steel
The three main types of stainless steels are austenitic, ferritic, and martensitic. These three types of steels are identified by their microstructure or predominant crystal phase.
Austenitic: Austenitic steels have austenite as their primary phase (face centered cubic crystal). These are alloys containing chromium and nickel (sometimes manganese and nitrogen), structured around the Type 302 composition of iron, 18% chromium, and 8% nickel. Austenitic steels are not hardenable by heat treatment.
The most familiar stainless steel is probably Type 304, sometimes called T304 or simply 304. Type 304 surgical stainless steel is an austenitic steel containing 18-20% chromium and 8-10% nickel.
Ferritic: Ferritic steels have ferrite (body centered cubic crystal) as their main phase. These steels contain iron and chromium, based on the Type 430 composition of 17% chromium. Ferritic steel is less ductile than austenitic steel and is not hardenable by heat treatment.
Martensitic: The characteristic orthorhombic martensite microstructure was first observed by German microscopist Adolf Martens around 1890. Martensitic steels are low carbon steels built around the Type 410 composition of iron, 12% chromium, and 0.12% carbon. They may be tempered and hardened. Martensite gives steel great hardness, but it also reduces its toughness and makes it brittle, so few steels are fully hardened.
There are also other grades of stainless steels, such as precipitation-hardened, duplex, and cast stainless steels. Stainless steel can be produced in a variety of finishes and textures and can be tinted over a broad spectrum of colors.
Suggested Reading
Metals & AlloysMetals QuizCopper Plate an Ornament
w('New posts to the Chemistry forums:Nernst Equation Worked ProblemChemistry Help PLEASE!!!electrochemistry help please')
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