Pattie Maes: Unveiling game-changing wearable tech

Why Are Humans Made Of Carbon? Chemist Points To Electrons, Molecular Bonds

Everything on earth is made up of combinations of different elements – all of which can be found on the periodic table. Considering that the periodic table contains 118 elements it seems a pity that organic life tends to feature only five or six of those elements in any vast quantities. The main one being carbon.

As well as being the main element in organic matter, carbon atoms are the only element in both graphite and diamond.

It would be impossible for life on earth to exist without carbon. Carbon is the main component of sugars, proteins, fats, DNA, muscle tissue, pretty much everything in your body. The reason carbon is so special is down to the electron configuration of the individual atoms. Electrons exist in concentric ‘shells’ around the central nucleus and carbon has four electrons in its outermost shell. As the most stable thing for an atom to have is eight electrons, this means that each carbon can form four bonds with surrounding atoms.

For more click here.

Credit:  http://www.huffingtonpost.com

Chemistry of Cooking

WHAT ARE ACIDS AND BASES? An acid is defined as a solution with more positive hydrogen ions than negative hydroxyl ions, which are made of one atom of oxygen and one of hydrogen. Acidity and basicity are measured on a scale called the pH scale. The value of freshly distilled water is seven, which indicates a neutral solution. A value of less than seven indicates an acid, and a value of more than seven indicates a base. Common acids include lemon juice and coffee, while common bases include ammonia and bleach.

WHY DOES FOOD SPOIL? Processing and improper storage practices can expose food items to heat or oxygen, which causes deterioration. In ancient times, salt was used to cure meats and fish to preserve them longer, while sugar was added to fruits to prevent spoilage. Certain herbs, spices and vinegar can also be used as preservatives, along with anti-oxidants, most notably Vitamins C and E. In processed foods, certain FDA-approved chemical additives also help extend shelf life.

This report has been produced thanks to a generous grant from the Camille and Henry Dreyfus Foundation, Inc.

Reported January 2009

Credit: http://www.ivanhoe.com/science/story/2009/01/528si.html

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New page for Computational Chemistry will start soon. Guest bloggers can send their articles, which are highly welcomed, and will be published with full credit.

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Statistical Mechanics

Defining statistical mechanics: Statistical Mechanics provies the connection between microscopic motion of individual atoms of matter and macroscopically observable properties such as temperature, pressure, entropy, free energy, heat capacity, chemical potential, viscosity, spectra, reaction rates, etc. 

Why do we need Statistical Mechanics:

1. Statistical Mechanics provides the microscopic basis for thermodynamics, which, otherwise, is just a phenomenological theory.
2. Microscopic basis allows calculation of a wide variety of properties not dealt with in thermodynamics, such as structural properties, using distribution functions, and dynamical properties - spectra, rate constants, etc., using time correlation functions.
3. Because a statistical mechanical formulation of a problem begins with a detailed microscopic description, microscopic trajectories can, in principle and in practice, be generated providing a window into the microscopic world. This window often provides a means of connecting certain macroscopic properties with particular modes of motion in the complex dance of the individual atoms that compose a system, and this, in turn, allows for interpretation of experimental data and an elucidation of the mechanisms of energy and mass transfer in a system.

For more details and lecture notes click here.


Credit: Professor M. Tuckerman  

New 2-D Material for Next Generation High-Speed Electronics

Scientists at CSIRO and RMIT University have produced a new two-dimensional material that could revolutionise the electronics market, making “nano” more than just a marketing term.

The material – made up of layers of crystal known as molybdenum oxides – has unique properties that encourage the free flow of electrons at ultra-high speeds. 

In a paper published in the January issue of materials science journal Advanced Materials, the researchers explain how they adapted a revolutionary material known as graphene to create a new conductive nano-material.  For more details click here.

Artist impression of high carrier mobility through layered molybdenum oxide crystal lattice. (Credit: Dr Daniel J White, ScienceFX)

Credit: Dr Daniel J White, http://www.csiro.au

Discovery Opens up Possibilities for a New Generation of Targeted Therapies for Cancer.

In 1953, Cambridge researchers Watson and Crick published a paper describing the interweaving ‘double helix’ DNA structure – the chemical code for all life.

Now, in the year of that scientific landmark’s 60^th Anniversary, Cambridge researchers have published a paper proving that four-stranded ‘quadruple helix’ DNA structures – known as G-quadruplexes – also exist within the human genome. They form in regions of DNA that are rich in the building block guanine, usually abbreviated to ‘G’.  For more click here.

Credit: http://www.cam.ac.uk

Credit: Prof. Shankar Balasubramanian, University of Cambridge

Atomic Chemistry

Atom, smallest unit of a chemical element that can exist. In ancient Greek philosophy the word “atom” was used to describe the smallest bit of matter that could be conceived of. This “fundamental particle”, to use the present-day term for this concept, was thought of as indestructible; in fact, the Greek word for atom (atomos) means “not divisible”. 

Knowledge about the size and nature of the atom did not begin to be acquired until long after the beginnings of experimental science in the 16th and 17th centuries. Although many of the new “experimental philosophers” believed in the reality of atoms, the progress of science owed little to the idea. The first quantitative explanation of the behaviour of matter in terms of atoms was attempted by Daniel Bernoulli in 1738, but his work was largely ignored. However, chemistry was discovering things about matter that only the idea of atoms could explain. 

Chemists recognized that all liquids, gases, and solids can be broken down into their ultimate components, or elements. For example, salt is a chemical compound formed when the elements sodium and chlorine react together and become joined in an intimate form known as a chemical compound. Air, by contrast, was found to consist of a mixture of the gases nitrogen and oxygen, which do not react with each other.

Credit: library.thinkquest.org/

Reull Vallis: a river ran through it

Reull Vallis: A River Ran Through It

Credit: http://www.esa.int

Overview of Computational Chemistry

Chemists have been some of the most active and innovative participants in this rapid expansion of computational science. Computational chemistry is simply the application of chemical, mathematical and computing skills to the solution of interesting chemical problems. It uses computers to generate information such as properties of molecules or simulated experimental results. Some common computer software used for computational chemistry includes:

• Gaussian xx, Gaussian 09 currently
• GAMESS
• MOPAC
• Spartan
• Sybyl  

Click here for more details.

 

Credit: http://www.shodor.org/chemviz/overview/

Molecule of the Week - Nitrous oxide

Molecule of the Week - Nitrous oxide

Chemistry of Glass

Obsidian, a black volcanic glass, is probably the best known of the naturally occurring glasses. It was used by early man to form cutting tools, arrowheads and spearheads and is now used by modern man to make the sharpest surgical blades.

Synthetic glass was originally prepared by heating a mixture of sodium oxide (or sodium carbonate), calcium oxide and silicon dioxide (sand). If calcium oxide was not added to the melt, soda glass was obtained. Pure soda glass is not usable because of its high solubility in water. Soda lime glass has a large coefficient of expansion when heated and a low resistance to the effects of acids and bases. It usually has a green color due to the presence of iron oxide in the sand. It was later discovered that this color could be removed by adding manganese oxide to the melt when a colorless glass was desired. 

Manufactured glass is presumed to have been first used as a glaze for pottery. The earliest known glaze is on stone beads of the Badarian age of Egypt. These beads ranked in value with precious metals and stones at the time! The Egyptians first made vessels out of glass by the laborious process in which the glass was applied over a wooden or metal rod bit by bit. A cylinder of light blue glass made by this method dates back to the Akkad dynasty in 2600 B.C. Glass was first pressed into open molds in 1200 B.C. There is some evidence that Mesopotamia was the location where glass was first manufactured.

For more details click here.

Credit: Prof. Richard Banks, http://chemistry.boisestate.edu

Dye Chemistry

Look around you, at your clothes, the walls, the floor. Chances are that you see before you a riot of colour. Humans have been fascinated by colour for thousands of years and use colours to warn, to seduce and primarily to decorate. So, what about the chemistry behind the decoration? What makes one molecule coloured, and another not? Why do some clothes fade in the wash?

The chemical basis of colours is the reason many people choose to do chemistry. The basis of this project is the chemistry behind fabric dyes- what are they? What are the origins of dyes? How are they made? What affects the way they attach to different fibres?

The search for highly coloured, colour fast dyes has fuelled major industry from ancient times right up to the present, from the Roman dye factories at Tyre, to modern chemical companies such as ICI. Nowadays, the chemist with a knowledge of organic chemistry is at the forefront of new dye development, altering the structures of known dyes, and inventing new ones.

For more click here.

Credit: http://www.chm.bris.ac.uk/webprojects2002

Lecture on Environmental Chemistry

Environmental chemistry is that branch of chemical science that deals with the production, transport, reactions, effects, and fates of chemical species in the water, air, terrestrial, and biological  environment and the effects of human activities thereon. For more click here.

Credit: http://www.asdlib.org/onlineArticle

Graphene-derived Nanorings of Electronic Power

Computational Chemistry Highlights: Graphene-derived nanorings of electronic power: P. V. Avramov, D. G. Fedorov, P. B. Sorokin, S. Sakai, S. Entani, M. Ohtomo, Y. Matsumoto, H. Naramoto, J. Phys. Chem. Lett. 3 (2012) 2003-2...

Credit: http://www.compchemhighlights.org

Largest Known Structure in the Universe

An international team of astronomers, led by academics from the University of Central Lancashire (UCLan), has found the largest known structure in the universe. The large quasar group (LQG) is so large that it would take a vehicle travelling at the speed of light some 4 billion years to cross it. The team publish their results in the journal Monthly Notices of the Royal Astronomical Society. For more details click here.

The coloured background indicates the peaks and troughs in the occurrence of quasars at the distance of the LQG. Darker colours indicate more quasars, lighter colours indicate fewer quasars. The LQG is clearly seen as a long chain of peaks indicated by black circles. (The red crosses mark the positions of quasars in a different and smaller LQG). The horizontal and vertical axes represent right ascension and declination, the celestial equivalent of longitude and latitude. The map covers around 29.4 by 24 degrees on the sky, indicating the huge scale of the newly discovered structure. Credit: R. G. Clowes / UCLan

Credit: Royal Astronomical Society

Walking Molecules!

Nanomotors are used throughout biology to perform tasks. Spectacular examples include the motor protein myosin that makes muscles contract by "walking" along molecular tracks in the cell. 

Professor David Leigh's group have made the first synthetic walking molecules that move directionally along molecular tracks. The ultimate goal of such research is to produce artificial molecular vehicles that can transport cargoes and perform other complex tasks at the nanoscale. 

However, such 'molecular engineering' is not easy: at the molecular level gravity is too weak to hold the walkers onto tracks and special molecular glue, footholds and attachment points all have to be carefully designed to make a successful walking molecule (see video). 

Credit: Professor David Leigh and co-workers, University of Manchester

Molecule of the Week - Pancuronium Bromide

Molecule of the Week - Pancuronium Bromide (January 11)

Credit: http://portal.acs.org

Stars are responsible for forging every heavy element in the universe when they fuse hydrogen and when they explode at the ends of their lives. But they also create a strange third type of chemical bond between atoms, caused by their incredible magnetic fields. This previously unknown type of bond could lead to new research in quantum science, perhaps even quantum computing. For more click here.

White Dwarf Stars This image from the Hubble Space Telescope shows a close-up of ancient white dwarf stars in the Milky Way. NASA and H. Richer (University of British Columbia)

Credit: http://www.popsci.com/science/article. Article you can find here.

What is EPR Spectroscopy?

Electron spin resonance (ESR) spectroscopy, also referred to as electron paramagnetic resonance (EPR) spectroscopy, is a versatile, nondestructive analytical technique which can be used for a variety of applications including: oxidation and reduction processes, biradicals and triplet state molecules, reaction kinetics, as well as numerous additional applications in biology, medicine and physics. However, this technique can only be applied to samples having one or more unpaired electrons. For more details click here.

Image Credit: http://web.nmsu.edu

Credit: http://epr.cm.utexas.edu

A Tribute to Stephen Hawking - The Man of the Universe

Stephen Hawking is the former Lucasian Professor of Mathematics at the University of Cambridge and author of A Brief History of Time which was an international bestseller. Now Director of Research at the Centre for Theoretical Cosmology at Cambridge, his other books for the general reader include A Briefer History of Time, the essay collection Black Holes and Baby Universe and The Universe in a Nutshell. For more details click here.

Credit: http://www.hawking.org.uk/

Introduction to Mössbauer Spectroscopy: Part 1

The technique of Mössbauer spectroscopy is widely used in mineralogy to examine the valence state of iron, which is found in nature as Fe⁰ (metal), Fe²⁺, and Fe³⁺, as well as the type of coordination polyhedron occupied by iron atoms (trigonal, tetrahedral, octahedral, etc.). It is sometimes used to determine redox ratios in glasses and (less successfully) in rocks. Mössbauer spectroscopy is also used to assist in the identification of Fe oxide phases on the basis of their magnetic properties. For more details click here.

Credit: M. Darby Dyar, Department of Astronomy, Mount Holyoke College

Chemistry - Facts

It is vital that the next generation understands that chemistry is everywhere; is a transforming force that improves lives and our society; and is an important profession, because careers in chemistry offer opportunities to change the world.

Image Credit: http://hilary-gio.blogspot.in

Credit: ACS, Chemistry for Life

Air Pollution

Air pollution is the presence in the atmosphere of any substance at a concentration great enough to produce an undesirable effect on humans, animals, vegetation, or materials, or to significantly alter the natural balance of any ecosystem. Air pollutants can be solids, liquids, or gases, and can have local, regional, and global impacts.

Read more: http://www.chemistryexplained.com/A-Ar/Air-Pollution.html#ixzz2H551WaIS

Introduction to Supramolecular Chemistry

The emergence of supramolecular chemistry has had a profound effect on how efficiently chemists prepare structures of different sizes and shapes with dimension in the range of 1 to 100 nm using spontaneous secondary interactions such as hydrogen bonding, dipoledipole, charge transfer, van der Waals, and p-p stacking interactions. This so-called “bottom up” approach to construct nanostructures is advantageous over the “top down” approach such as microlithography which requires substantial effort to fabricate microstructures and devices as the target structures are extended to the range below 100 nm. For more details click here.

Image credit: Professor Kenneth N. Raymond
UC Berkeley Chancellor's Professor

Credit: http://scholar.lib.vt.edu

What is Laser?

The term laser should not sound alien to you. We often encounter laser in our daily life, examples include the laser pointer used in classrooms, and the CD-ROMs in a computer or in a hi-fi that are used to read the data stored in a CD. In industry, laser is often used for cutting and microscopic processing. For military purposes, laser is used to intercept guided missiles. Scientists have also accurately measured the distance between the Earth and the Moon by using laser; the error involved is only a few centimeters. These are some extensive applications of laser. So actually how is it produced? We will explain the basic principles of laser below. For more details click here.

Credit: http://www.hk-phy.org

Particle in a 1-D Box

For detailed derivation click here.

Image credit: http://chemwiki.ucdavis.edu

Credit: http://www.cobalt.chem.ucalgary.ca/ziegler/Lec.chm373/Lec9/CHAPTER7.pdf

Message to Students

Chemistry is everywhere. Our world is a chemical system and so are we. Learn something new in chemistry to learn something new about the world and yourself. 

Image credit: http://www.chemieisoveral.nl

Credit: Tweet from ChemandInd

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WISHING A HAPPY NEW YEAR TO ALL BLOG READERS...

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