The following is a list of the group which is developing the telescope.
George P. Mitchell, founder of Mitchell Energy & Development Corp., and The Cynthia and George Mitchell Foundation are giving $25 million to help pay for the telescope.
Stinging nettle
Stinging nettles ("Urtica dioica") are a type of plant which have stinging defensive hairs on the leaves and stems. Stinging nettles can be found in America, Europe and Asia.
The hairs inject histamine and other chemicals that produce a stinging sensation when contacted by humans and other animals. Soaking stinging nettles in water or cooking removes the stinging chemicals from the plant, which allows them to be handled and eaten without injury.
The plant has been used as medicine, food, tea and fibre. Nettles are sometimes used in cheesemaking, as nettle soup or as substitute for spinach. Its stems contain a bast fibre that is used for the same purposes as linen. Nettles have been used to make clothing for 2,000 years.
Stinging nettles are important food plants for several butterflies, like the peacock butterfly and the small tortoiseshell. Also some deers and other animals eat the plant, preferred the leaf shot.
Ferrari F50
The Ferrari F50 is a sports car made by Ferrari in 1995. It was created to celebrate the company's 50th anniversary. The car has two doors. It is a two-seated convertible with a removable hardtop. It has a 4.7 L V12 engine that was based on the 3.5 L V12 used in the 1992 Ferrari F92A Formula One car.
Only 349 Ferrari F50's were made. This was because Ferrari wanted it to be rare. The last F50 was produced in Maranello, Italy in July 1997.
The Ferrari F50 can travel at over 200 miles per hour.
Mass spectrum
A mass spectrum is an intensity versus "m/z" (mass-to-charge ratio) plot that represents a chemical analysis. The mass spectrum of a sample is a pattern representing the distribution of ions by mass (more correctly: mass-to-charge ratio) in a sample. It is a histogram usually made using an instrument called a mass spectrometer. Not all mass spectra of a given substance are the same. It can depend on the operating conditions of the instrument. For example, some mass spectrometers break the analyte molecules into many pieces; others observe the intact molecular masses with little fragmentation. A mass spectrum can represent many different types of information based on the type of mass spectrometer and the specific experiment; however, all plots of intensity vs. mass-to-charge are called "mass spectra".
Common fragmentation processes for organic molecules are the McLafferty rearrangement and alpha cleavage.
In the past, chemists with PhD degrees were needed to interpret mass spectra. Today, computer programs read the data and identify the compounds in a sample.
Stuntman (video game)
Stuntman is a racing/action video game that was published by Infogrames and Atari. It was released for the PlayStation 2 and the Game Boy Advance systems. The game is also featured as a mobile phone game which could be downloaded. Stuntman was followed by the 2007 sequel, . The game received positive reviews, GameSpot gave it a 8.0 out of 10 and IGN gave it a 8.6 out of 10.
Eh, Eh (Nothing Else I Can Say)
"Eh, Eh (Nothing Else I Can Say)" is a single by Lady Gaga. It appeared on Gaga's debut album "The Fame" and was released as a single on January 10, 2009. Its music video references Gaga's Italian heritage. Though the single did not chart in the United States, the Recording Industry Association of America certified the song gold on February 29, 2016, for shipments and streams equal to 500,000 copies there. "Eh, Eh" charted in the top ten in France, New Zealand and Sweden.
SN2 reaction
The S2 reaction (also known as bimolecular nucleophilic substitution) is a substitution reaction in organic chemistry. It is a type of nucleophilic substitution, where a lone pair from a nucleophile attacks an electron deficient electrophilic center and bonds to it. This expels another group called a "leaving group". So, the incoming group replaces the leaving group in one step. Since two reacting species are involved in the slow, rate-determining step of the reaction, this leads to the name "bimolecular nucleophilic substitution", or "S2". Among inorganic chemists, the S2 reaction is often known as the "interchange mechanism".
The reaction most often occurs at an aliphatic sp carbon center with an electronegative, stable leaving group attached to it - 'X' - frequently a halide atom. The breaking of the C-X bond and the formation of the new C-Nu bond occur simultaneously to form a transition state in which the carbon under nucleophilic attack is pentacoordinate, and approximately sp hybridized. The nucleophile attacks the carbon at 180° to the leaving group, since this provides the best overlap between the nucleophile's lone pair and the C-X σ* antibonding orbital. The leaving group is then pushed off the opposite side and the product is formed.
If the substrate under nucleophilic attack is chiral, this can lead, although not necessarily, to an inversion of stereochemistry, called the Walden inversion.
In an example of the S2 reaction, the attack of OH (the nucleophile) on a bromoethane (the electrophile) results in ethanol, with bromide ejected as the leaving group:
A S2 reaction occurs if the backside route of attack is not blocked by other atoms in the molecule (sterically hindered by substituents on the substrate). So, this mechanism usually occurs at an unhindered primary carbon center. If there is steric crowding on the substrate near the leaving group, such as at a tertiary carbon center, the substitution will use an S1 rather than an S2 mechanism, (an S1 would also be more likely with blocked molecules because a sufficiently stable carbocation intermediary could be formed.)
In coordination chemistry, associative substitution proceeds by a similar mechanism as S2.
Four factors affect the rate of the reaction:
The rate of an S2 reaction is second order, as the rate-determining step depends on the nucleophile concentration, <nowiki>[</nowiki>Nu<nowiki>]</nowiki> as well as the concentration of substrate, <nowiki>[RX]</nowiki>.
This is a key difference between the S1 and S2 mechanisms. In the S1 reaction, the nucleophile attacks after the rate-limiting step is over. But in a S2 reaction, the nucleophile forces off the leaving group in the limiting step. In other words, the rate of S1 reactions depend only on the concentration of the substrate while the S2 reaction rate depends on the concentration of both the substrate and nucleophile. In cases where both mechanisms are possible (for example at a secondary carbon center), the mechanism depends on solvent, temperature, concentration of the nucleophile or on the leaving group.
S2 reactions are generally favored in primary alkyl halides or secondary alkyl halides with an aprotic solvent. They occur at a negligible rate in tertiary alkyl halides due to steric hindrance.
S2 and S1 are two extremes of a sliding scale of reactions. It is possible to find many reactions which exhibit both S2 and S1 character in their mechanisms. For instance, it is possible to get a contact ion pairs formed from an alkyl halide in which the ions are not fully separated. When these undergo substitution the stereochemistry will be inverted (as in S2) for many of the reacting molecules but a few may show retention of configuration. S2 reactions are more common than S1 reactions.
A common side reaction taking place with S2 reactions is E2 elimination: the incoming anion can act as a base rather than as a nucleophile, removing a proton and leading to formation of the alkene. This effect can be demonstrated in the gas-phase reaction between a sulfonate and a simple alkyl bromide taking place inside a mass spectrometer: