Quotes of All Topics . Occasions . Authors
By combining chemical, biochemical and physical techniques, it has thus become possible to investigate the nature of enzymic catalysis in a novel manner, complementary to the other approaches which have developed over the same period.
Laboratory experiments, field observations and atmospheric modeling calculations have now established that chemical reactions occurring on PSC particles play a central role in polar ozone depletion.
No one knows what the nongenetic causes of individuality are. Perhaps people are shaped by modifications of genes that take place after conception, or by haphazard fluctuations in the chemical soup in the womb or the wiring up of the brain or the expression of the genes themselves.
In the three years since Obama invited Russia to help him renege on his 'red line' on the use of chemical weapons in Syria, the Syrian Network for Human Rights has documented 136 occasions in which the Assad regime has deployed poison gas in its war on the Syrian people.
Finally, as the digestive canal is a complex system, a series of separate chemical laboratories, I cut the connections between them in order to investigate the course of phenomena in each particular laboratory; thus I resolved the digestive canal into several separate parts.
Our chemical and other manufacturing concerns are all too often ready to let the Germans have Latin American markets, provided the American companies can work out an arrangement which will enable them to charge high prices to the consumer inside the United States.
As a black person in America, I am twice as likely as a white person to live in an area where air pollution poses the greatest risk to my health. I am five times more likely to live within walking distance of a power plant or chemical facility - which I do.
After all, the universe required ten billion years of evolution before life was even possible; the evolution of the stars and the evolving of new chemical elements in the nuclear furnaces of the stars were indispensable prerequisites for the generation of life.
The first true antibiotic to be derived from a culture of an actinomyces was isolated in our department in 1940. The organism, Actinomyces antibioticus, yielded a substance which was designated as actinomycin. It was soon crystallized, and its chemical and biological properties were established.
As soon as we can wrest from Nature the secret of the internal structure of the compounds produced by her, chemical science can then even surpass Nature by producing compounds as variations of the natural ones, which the living cell is unable to construct.
Syria is important because it lies at the heart of a region critical to U.S. security, a region that is home to friends and partners and one of our closest allies. It is important because the Syrian regime possesses stores of chemical weapons that they have recently used on a large scale and that we cannot allow to fall into terrorists' hands.
I've always seen My Chemical Romance as the band that would have represented who me and my friends were in high school, and the band that we didn't have to represent us - the kids that wore black - back then.
But the nature of my main work in chemistry can be better represented by more than 280 English publications, of which roughly 200 concern the theory of chemical reactions and related subjects.
There's another issue here - and I have some limits as to what I can say - but there's some real question as to the viability of the chemical masks, the protective gear used by our soldiers.
I'd like to see what fraction of things that chemists have figured out we could actually teach nature to do. Then we really could replace chemical factories with bacteria.
By recognizing that the chemical atom is composed of single separable electric quanta, humanity has taken a great step forward in the investigation of the natural world.
To the field of synthetic chemistry belongs an array of responsibilities which are crucial for the future of mankind, not only with regard to the health and needs of our society, but also for the attainment of a deep understanding of matter, chemical change, and life.
The well-known fact that the form of a specific substance, e.g. water, and hence its properties can alter without a change in composition was disposed of by the formal view that a physical, not a chemical, process was involved.
I take very seriously my responsibility as Secretary-General to make sure that the United Nations is doing everything it can to uphold the universal prohibition on the use of chemical weapons.
The United States, a signatory to the Chemical Weapons Convention, destroyed the last of its stocks of VX and other chemical agents on the Johnston Atoll, 825 miles southwest of Hawaii, in November 2000.
We found out that we were dealing with a completely unregulated chemical, this chemical PFOA. This was a chemical that was a completely manmade material invented right after World War Two, didn't exist on the planet prior to the 1940s.
It has been almost three years since U.S. President Barack Obama pipsqueaked on his chemical-weapons 'red line' in Syria and joined with Russian strongman Vladimir Putin in the pantomime that resulted in the Sept. 27, 2013 U.N. Security Council Resolution 2118, which called on Assad to surrender his chemical weapons stockpile.
This simple idea served to provide information on the geometrical shape of reacting molecules, and I was able to make the role of the frontier orbitals in chemical reactions more distinct through visualization, by drawing their diagrams.
The DNA-encoded catalytic machinery of the cell can rapidly learn to promote new chemical reactions when we provide new reagents and the appropriate incentive in the form of artificial selection.
The discovery of various phenomena has led to a recognition of the fact that the chemical atom is an individual which again is itself made up of several units into a selfcontained whole.
To a synthetic chemist, the complex molecules of nature are as beautiful as any of her other creations. The perception of that beauty depends on the understanding of chemical structures and their transformations, and, as with a treasured work of art, deepens as the subject is studied, perhaps even to a level approaching romance.
The distinction between the old and the new formulations consisting in the incorporation of the concept of the rate of chemical reactions is so great that it immediately asserted itself in the objective development of catalysis.
I believe that the topic of chemical weapons is critically important for international peace and security, and I take note of the ongoing debate over what course of action should be taken by the international community. All those actions should be taken within the framework of the U.N. Charter, as a matter of principle.
Leaders at the top of al Qaeda's hierarchy, the evidence shows, completed plans and obtained the materials required to manufacture two biological toxins - botulinum and salmonella - and the chemical poison cyanide.
And in my world, when I was dealing with this for our chemical company clients, you had lists of regulated hazardous materials, and things were permitted. And if you had a landfill and you had a permit, you had to comply with certain limits.
My whole interest is, how do you use evolution as an innovation engine? How does evolution solve new problems that life faces? And to have a system that can create a whole new chemical bond that biology hasn't done before, to me, demonstrates the power of nature to innovate.
With this in mind, for some twenty years I have set myself as my particular task the experimental investigation of the connexion between change in the structure and change in the spectra of chemical atoms.
In the first quarter of the nineteenth century the experimental proof for the interdependence of the composition and properties of chemical compounds resulted in the theory that they are mutually related, so that like composition governs like properties, and conversely.
At the height of Iraq's clandestine nuclear weapons program, which nearly succeeded in building a bomb in 1991, Tuwaitha incorporated research reactors, uranium mining and enrichment facilities, chemical engineering plants and an explosives fabrication center to build the device that detonates a nuclear core.
We're talking about a chemical that's out there. Not just on one farm in West Virginia, not even just in the public water of an entire community there, but it's now in water all over the country, all over the planet, in the blood of virtually every living thing.
For me, I was always the only woman in my cohort, first as a mechanical engineering undergraduate student, then as a chemical engineering graduate student. There were very few women getting degrees in those fields at the time. My role models were men - great men role models.
Moreover, the abundance of chemical compounds and their importance in daily life hindered the chemist from investigating the question, in what does the individuality of the atoms of different elements consist.
For under certain conditions the chemical atoms emit light waves of a specific length or oscillation frequency - their familiar characteristic spectra - and these can come in the form of electromagnetic waves only from accelerated electric quanta.