Most climatologists, ecologists, and even the World Bank have all reached a consensus that climate change is occurring. Experts and policymakers alike have attributed rising concentrations of carbon dioxide to net warming, but finding straightforward evidence of this can be difficult. Now, a team of researchers claims that they have identified, for the first time, how global warming is related to the amount of carbon emitted in a mathematical proof.
Solar power just hit one of its biggest milestones, in more ways than one. First Solar recently finished building Topaz, a 550-megawatt plant that represents the largest active solar farm on the planet.
Atoms with the same number of protons belong to the same element. Atomic nuclei with the same number of protons and different numbers of neutrons are called isotopes. The elements up to uranium (element 92) exist in nature (except for technetium ). The elements heavier than uranium are man-made. All elements are arranged in the periodic table of the elements. Their positions in the periodic table correspond to their proton number; elements in the same column (i.e., in the same group) feature similar and electronic shell structure, which characterizes the chemical behavior of an element. An element's position in the periodic table and thus provides information on its chemical behavior, e.g., as a metal or an inert gas.If atomic nuclei have too many protons (all of which repel each other) or have an this ratio is unfavorable proton to neutron ratio, the nuclei are not stable but undergo radioactive decay. The elements up to the element fermium (which has atomic number 100) can be produced at research reactors by irradiating a target of a heavy element with neutrons. The target atoms capture a neutrons and subsequently decay through β--emission, thus forming an element with the next higher proton number. This process can be repated, up to fermium.As there are no isotopes of fermium which decay through β--emission, no elements with higher proton number can be synthesized by this method.The heavier an atom is, the more protons are contained in its nucleus. With increasing proton number, the repulsive force of these protons will eventually lead to immediate disintegration of the nucleus. The elements with a proton number higher than 103 can only exist due to nuclear shell effects and are called the superheavy elements. A topic of intense research concerns the question of the heaviest possible element. To date, all elements up to element 112 as well as elements 114 and 116 are officially recognized as discovered, and reports about the observation also of element 113,115, 117, and 118 are also published. It is currently not clear, which element is the heaviest one that can exist.The production of 265Sg and its separation in GARIS was perfected in preparatory work led by Dr. Hiromitsu Haba from RIKEN Nishina Center (RNC) and his team. In this nuclear reaction, a few Sg atoms per hour can be produced.Seaborgium hexacarbonyl – Why is it so special?Carbon monoxide (CO) is known to form complexes with many transition metals. In 1890, Ludwig Mond, Carl Langer and Friedrich Quincke reported of the first synthesis of a carbonyl complex – nickeltetracarbonyl ( Ni(CO)4; see here). In this compound, the nickel (Ni) atom is surrounded by 4 carbon monoxide molecules (CO).In this type of molecule, coordination bonds (rather than covalent bonds) form between the metal and the carbon monoxide.The carbon monoxide ligands bind to the metal by forming a so-called σ-donation bond, and a π-backbond from the metal to the carbon monoxide ligand establishes. In the σ-donation bond the highest occupied molecular orbital (HOMO) of the CO donates electron density into the σ-symmetric orbitals of the metal (s or p1/2 or dz2 orbitals). In the π-backbonding, electron density for the π-symmetric d-orbital is donated to the lowest unoccupied molecular orbital (LUMO) of the CO-ligand. The σ-donation bond is the strongest bond, while the π-backbond is slightly weaker.Synthesis of carbonyl complexes with fusion products directly behind the target in a CO-containing atomosphere is not possible, as the primary beam would pass the gas and create a plasma. This would destroy the CO molecules. Therefore, only our new approach to perform chemical experiments behind a separator like TASCA or GARIS allows the synthesis and study of this compound class.Chemistry experiments with superheavy elements - with periodic numbers higher than 104 – are difficult to perform. First, scientists have to produce the element artificially in a particle accelerator. The production rates are really low, usually lower than a few atoms per day. Furthermore, these atoms are very instable, and survive in the best case less than 10 seconds. However, science is still very interested to investigate the characteristics of these superheavy elements, since they allow to test the influence of Einstein's relativity theory on chemistry. The high number of positively charged protons in the atomic nucleus of superheavy elements accelerate the electrons in the different shells to extremely high velocities - close to 80% of the speed of light. Due to the relativistic effects at these speeds, electrons are much heavier than when they are at rest, which in turn should have some influence on the chemical properties of the superheavy atom. These effects will be compared with elements that possess a similar atomic structure but are lighter. Such studies will be of enormous interest to all basic chemists in the world.
Via Dr. Stefan Gruenwald
“Discovery might ultimately lead to new, more energy-efficient transistors and microchips.”When moving through a conductive material in an electric field, electrons tend to follow the path of least resistance — which runs in the direction of that field.But now physicists at MIT and the University of Manchester have found an unexpectedly different behavior under very specialized conditions — one that might lead to new types of transistors and electronic circuits that could prove highly energy-efficient.They’ve found that when a sheet of graphene — a two-dimensional array of pure carbon — is placed atop another two-dimensional material, electrons instead move sideways, perpendicular to the electric field. This happens even without the influence of a magnetic field — the only other known way of inducing such a sideways flow.What’s more, two separate streams of electrons would flow in opposite directions, both crosswise to the field, canceling out each other’s electrical charge to produce a “neutral, chargeless current,” explains Leonid Levitov, an MIT professor of physics and a senior author of a paper describing these findings this week in the journal Science.The exact angle of this current relative to the electric field can be precisely controlled, Levitov says. He compares it to a sailboat sailing perpendicular to the wind, its angle of motion controlled by adjusting the position of the sail.Levitov and co-author Andre Geim at Manchester say this flow could be altered by applying a minute voltage on the gate, allowing the material to function as a transistor. Currents in these materials, being neutral, might not waste much of their energy as heat, as occurs in conventional semiconductors — potentially making the new materials a more efficient basis for computer chips.“It is widely believed that new, unconventional approaches to information processing are key for the future of hardware,” Levitov says. “This belief has been the driving force behind a number of important recent developments, in particular spintronics” — in which the spin of electrons, not their electric charge, carries information.
Via Dr. Stefan Gruenwald
In a petri dish in the bowels of Harvard Medical School scientists have tweaked three genes from the cells of an Asian elephant that help control the production of hemoglobin, the protein in blood that carries oxygen. Their goal is to make these genes more like those of an animal that last walked the planet thousands of years ago: the woolly mammoth.
"Asian elephants are closer to mammoths than either is to African elephants, yet quite different in appearance and temperature range," notes Harvard geneticist and technology developer George Church. "We are not trying to make an exact copy of a mammoth, but rather a cold-resistant elephant."
But what if the new—and fast advancing—techniques of genome editing allowed scientists to engineer not only cold-resistance traits but also other characteristics of the woolly mammoth into its living Asiatic relatives? Scientists have found mammoth cells preserved in permafrost. If they were to recover cells with intact DNA, they could theoretically “edit” an Asian elephant’s genome to match the woolly mammoth’s. A single cell contains the complete genetic instruction set for its species, and by replicating that via editing a new individual can, theoretically, be created. But wouldsuch a hybrid—scion of an Asian elephant mother and genetic tinkerers—count as a true woolly mammoth?
In other words, is de-extinction a real possibility?
The answer is yes. On January 6, 2000, a falling tree killed the last bucardo, a wild Iberian ibex, which is a goatlike animal. Her name was Celia. On July 30, 2003, Celia's clone was born. To make the clone scientists removed the nucleus of a cell from Celia intact and inserted it into the unfertilized egg cell of another kind of ibex. They then transferred the resulting embryo to the womb of a living goat. Nearly a year later theydelivered the clone by cutting her from her mother.
Although she lived for a scant seven minutes due to lung defects, Celia’s clone proved that not only is de-extinction real, "it has already happened," in the words of environmentalist Stewart Brand, whose San Francisco-based Long Now Foundation is funding some of this de-extinction research, including Church's effort as well as bids to bring back the passenger pigeon and heath hen, among other candidate species. Nor is the bucardo alone in the annals of de-extinction. Several viruses have already been brought back, including the flu variant responsible for the 1918 pandemic that killed more than 20 million people worldwide.
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