Monthly Archives: January 2016

Periodic table in song !!

If you want to take a break, just look this video , moreover it could help you to memorize  utility  of  elements !

https://www.youtube.com/watch?v=VgVQKCcfwnU

Lyrics: hydrogen helium lithium beryllium boron carbon nitrogen oxygen fluorine neon sodium magnesium aluminum silicon phosphorus sulfur chlorine argon potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon cesium barium cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury thallium lead bismuth polonium astatine radon francium radium actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium ununbium ununtrium flerovium ununquadium ununpentrium livermorium ununseptium ununoctium

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Evolution of Prosthetics

Over the past hundreds of years, prosthetics has evolved immensely, and the most notable breakthroughs have been in the past century. As a result, there are various and several prosthetics available today, and they are constantly being improved. However, the cost, tests and ethics are a major factor in how far prosthetics could potentially go.

Prosthetics are artificial devices used as for externally as internally for replacing or restoring certain parts of the body. These prosthetics help regain the lost functionality of the body part that unfortunately missing or malfunctioning. We know the most common types of prosthetics today such as the arm or the leg, and more recently, the heart !

The first invented prosthetics were very limited , their functionality was simply to make movement easier for people who had lost an extremity. This meant that for a leg that needed to be amputated, or that was lost in any way, there was initially no other prosthetic like device that was put in its place. It is thus, we can see, over the hundreds of years from when prosthetics were first engineered this has changed according to engineering.

Many amputations were necessary for reasons which were other than being wounded in combat. Thus, it really was not until World War II that the importance of having functional prosthetics escalated. When wounded soldiers from combat would return at home, replace a member was a very useful way to live a « normal » life again. . At this point in time, the United States government decided to help fund development and research of prosthetics to design prosthetics that were functional. From this point forwards, breakthroughs like the suction sock for aboveknee prosthetics and computerized prosthetics have paved the way for modern prosthetics today.

Nowadays, there are now three very common types of prosthesis available in the market. The first type of prosthesis is the cosmetic prosthesis. This type of prosthetic has low, passive functionality, and is generally used for upper limb amputations. The next type of prosthesis is the body-powered prosthesis. This type of prosthetic has a moderate level of functionality that is provided from muscles near the relative area of the prosthetic; it is generally used for upper limb amputations. Then the third type of prosthesis is the myoelectric prosthesis

Sans nom 1

Of these three types of prosthesis, the most expensive is the myoelectric, ranging from $80,000-$100,000 due to the expensive technology in the device.

However, some major problems engineers and developers face is the relatively low amount of volunteers willing to test out new prototype designs. Prosthetics is a sensitive subject for most individuals and the majority do not feel comfortable testing out a prosthesis that is in the testing stage. An other major issue is the cost of the prosthesis. In order to have the most functional prosthetic on the market, it costs well above $80,000.

A main goal of current biomedical engineers working on prosthetics is to try to develop a more affordable prosthetic…

Science Fair Projects

Understanding and Using the Scientific Method

  The scientific method is the backbone of every science experiments, and understand it is critical to the success of our science fair experiment. Three different kinds of people can witness the same event, and each come up with a different account of how it occurred. Investigators know that this is true. You’ve probably had some experiences with this phenomenon, as well. Have you ever had other people who attended the same event give you completely different reports of what happened?

  These conflicting viewpoints occur because we all see the world differently. We all have beliefs, biases, and perceptions that cause us to view things the way we do.

  While these differences are what make us each unique and assure that the world is place and can make it difficult to determine what is really true and what isn’t.

  Scientists over the centuries found they faced the same problems when it came to sorting out the truth from nontruths. To solve the problem, they devised a methodical framework within which to work. This framework is called the scientific method, and it’s extremely important to your science fair project.

The Scientific Method Made Easy

  The scientific method is a tool that helps scientists and the all of us to solve problems and determine answers to questions in a logical format. It provides step-by-step, general directions to help us work through problems.

Basic Elements

  The scientific method is a series of steps that serve as guidelines for scientific endeavors. It’s a tool used to help solve problems and answer questions in an objective manner. You probably use the scientific method in your life, everyday without realize it.

Standard Procedure

  There are two forms of scientific method, but they both require the same objective reasoning and steps. The experimental method employs numerical data and graphs, while the descriptive method gathers information through visual observation and interviewing. The experimental method generally is used in physical sciences.

Without realizing it, you’ve just worked through the steps of the scientific method to solve a problem.

For our purposes, there are five steps to the scientific method :

1. Identify a problem.

2. Research the problem.

3. Formulate a hypothesis.

4. Conduct an experiment.

5. Reach a conclusion.

When your flashlight wouldn’t turn on, you knew you had a problem. That took care of the first step (Identify a problem). Your research,the second step, was conducted when you thought back to the last time your flashlight didn’t work. You completed the third step.

You conducted your experiment with the fourth step. You completed the fifth step of the scientific method and proved your hypothesis to be correct.

So you see, the scientific method is not mysterious or difficult, although you can use it to work through some difficult problems.

Very interesting !!

When you enter in the experimental world of chemistry, you can forget some easy rules learned some years ago. It’s for that I have searched about a website which summarizes all about we need, or remember.

Let’s go:

   1. Measurement in science

http://www.chemtutor.com/unit.htm#measur

   2. Elements

http://www.chemtutor.com/elem.htm

   3. Reactions

http://www.chemtutor.com/react.htm

  4. Solutions

http://www.chemtutor.com/solution.htm

  5. Atomic structure

http://www.chemtutor.com/struct.htm

  6. Periodic table

http://www.chemtutor.com/perich.htm

  7. Compounds

http://www.chemtutor.com/compoun.htm

   8. Acids and bases

http://www.chemtutor.com/acid.htm

Don’t have any doubt, click on the link you need, it’s the best choice to make when we want keep in mind our knowledges and applicate them in our own chemistry !!!

Use of washing baths in organometallic chemistry

Use of basic bath

(Composition: isopropanol, potash, water)

Only glassware used for sensitive products needs to be washed in basic bath, including glassware used in the glovebox such as schlenks, key, vials. Before place the glassware in the bath, clean them as any other organics glassware, if this is insufficient or ineffective, use different solvents (dichloromethane, pentane…) then rinse them with acetone. Don’t forget to remove the grease with pentane or petroleum ether, also remove all entries (markers), labels, or other external items (scotch, parafilm). Dirty glassware doesn’t be accumulated during the day on the bench; it is a work to be done throughout the day and not at the last moment before leaving the laboratory. Glassware will thus stay overnight in the bath then will be remove the following day before 12 a.m. Put them in the sink and wash abundantly the glassware with water from the tap then thoroughly with acetone, let them dry in open air on the drying racks. It was only after these steps that the glassware could be placed in the ovens.

Use of acid bath

(Composition: hydrochloric acid diluted in water) The acid bath is used according to the same procedure as the basic bath. Its use is less frequent, useful to eliminate residues of metal salts. It is very useful to penetrate into the pores of fried glass funnels also you can put the stirring bars. Once glassware is removed from the bath, proceed as described above for the basic wash thoroughly with warm water, rinse with acetone then let dry.

Useful links for scientists

     Often, we need to know the name of an abbreviation, of course you will find it on the web but what else of a single link about the abbreviations which give the name of the molecules, and the reactions that involves this molecule. You will find your satisfaction as mine in this link:

http://www.name-reaction.com/abbreviations

A little overview and don’t hesitate!

example:

Capture d’écran 2016-01-17 à 09.32.35

    You will enjoy this link if you often need the properties of a molecule, just enter the formula and you will have a comprehensive list about it: chemical names and formulas, structure diagram, 3D structure, basic properties, liquid properties , thermodynamic properties, phase diagram, chemical identifiers and toxicity properties.

http://www.wolframalpha.com/widgets/view.jsp?id=80f64ddcf98728dd1798bf92c133f45c

      It’s always useful to have a calculator of atomic mass at hand, you have to write the formula of your molecule and submit…

http://www.wolframalpha.com/widgets/view.jsp?id=4f4e6db491289533f41809892c14e549

example:

   pKa and pH calculator will make some joyful student, enter the name and the molarity, for example HCl (2M) and you will have pKa, Ka, pH,….

http://www.wolframalpha.com/widgets/view.jsp?id=4f41dd9d6beac8e8648b9c211f89546a

Journal titles and abbreviations

When you want to give a citation, sometimes, in the review, you haven’t the abbreviation of the Journal. For this, I post here a very useful link with all Journal categories, and the correspondent abbreviation.

For example:

Adv. Polym. Sci         —>        Advances in Polymer Science

So this link is made for that ! just chose the first letter of your Journal, and find in the list it !!!

http://www.rci.rutgers.edu/~longhu/ChemJournalAbbreviation_Hu.htm

Hope you enjoy the link !

And … have a happy new year