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What are the advantages and disadvantages of SMILES, InChIs and InChIKeys?
SMILES (Simplified Molecular Input Line Entry Specification) A major advantage of the SMILES system is the extensive software support of the algorithm. Many molecule editors allow for the conversion of the two-dimensional structure into the SMILES format. [|Link] Other friendly features of this system are it's simple and compact nature, allowing for it to be relatively human understandable. [|Link] In addition, it can also handle the representation of isotopes and reactions. [|Link]

InChIs (International Chemical Identifier) This is the first major non-proprietary computerized molecular structure representation algorithm that preserves the uniqueness of a particular compound. It was inspired by the IUPAC compound naming system. [|Link]However, this system presented an issue during searches.[| Link]

InChIKeys This format which is a hashed version of the InChI system was developed for the purpose of easier searching. [|Link] However, this hashed version of InChI allows for duplicate values. Though the probability of finding a duplicate value is very small. [|Link]

Summary of Article Investigation on combustion and emissions of DME/gasoline mixtures in a spark-ignition engine Fuel Volume 90, Issue 3, March 2011, Pages 1133-1138
 * Changwei Ji,****Chen Liang****, Shuofeng Wang**

[|DOI]
 * [Full Marks JCB]**


 * __Introduction__**
 * There are many chemical and physical properties that make dimethyl ether (DME) quite favorable for combustion in an internal combustion engine.
 * DME is also very environmentally friendly both before and after its combustion.
 * The relatively lower energy output of DME causes a decrease in octane rating of the gasoline it is mixed with.


 * __Experimental setup__**
 * The apparatus of the experiment, a spark ignition engine that had been fitted with additional injectors for DME, is described in detail.
 * The input parameters, output parameters and variables are prepared for recording by assorted instrumentation.
 * The error in each instrument is noted.


 * __Experimental procedure__**
 * Engine speed, manifold pressure and fluid temperatures were among some of the values listed at which the experiment was conducted.
 * While running the experiment, the DME content of the mixture was varied.
 * Equations for the DME energy fraction, reactant ratios, and the total energy flow rate are provided.


 * Constants and parameters that are used in the equations that are described in the previous paragraphs are listed with units.
 * Corrections to the spark timing is described.
 * The measurement software and the measurements it made are introduced.


 * __Fuel energy flow rate__**
 * The decrease in output energy as a function of increasing DME concentration is discussed.
 * It is noted that since the DME is injected in a gaseous phase it will be in competition for the same space that the air usually occupies. (A major influence on the total output)


 * __Brake thermal efficiency__**
 * A relationship between "brake thermal efficiency" and the "DME energy fraction" is presented.
 * This curve increases, peaks, then decreases, showing that the "brake thermal efficiency can be maximized at a certain reactant ratio.


 * __Combustion__**
 * The flame development duration and the flame propagation durations are defined.
 * These terms were used in the correction of the spark timing to achieve maximum torque with minimum knocking.


 * The flame development duration decreases as the DME ratio increases.
 * The reasons for this have to do with the premature oxidation of the DME and also with the modified spark timing at high DME ratios.


 * The flame propagation duration is described as a function of the DME ratio.
 * This curve decreases to a minimum, and then rises.
 * It is proposed that this minimum point could be caused by the DME accelerating the gasoline combustion with air.


 * The measurement of the baseline peak cylinder temperature is made by a run with only gasoline.
 * As the DME ratio increases, the peak cylinder temperature decreases, which is consistent with the lower combustion energy of DME.


 * __Cyclic variation__**
 * Statistical analyses are applied to assess the variation in the mean effective pressure.
 * This demonstrates the effects that flame development and propagation have on the system.


 * __Untreated emissions__**
 * The hydrocarbon emissions are reported as a function of %DME.
 * The data shows that the increased DME promotes a more complete combustion of hydrocarbons until it reaches a point that it begins to do the opposite.


 * The Nitrogen based emissions decrease as %DME increases. This is caused by the decrease in the air (nitrogen source) in the reactants.


 * The CO output reaches a minimum near the same input ratios as observed at the minimum of flame propagation time.
 * It is hypothesized that this could be due to the lack of time for carbon monoxide to oxidize to form carbon dioxide.


 * __Conclusions__**
 * In spite of the decrease in input potential energy with the addition of DME, the brake thermal efficiency increases.
 * The addition of DME reduced the operating temperature, reduced the unwanted emissions, and changed the flame characteristics.

Compound: Aspartame Chemical Property: Melting Point


 * < Source ||< Value ||< Source Unit ||< Common Value ||< Common Unit ||< Website ||
 * < Drug Bank ||< 246 - 247 ||< C ||< 519.65 ||< K ||< [] ||
 * < Oxford ||< 249 ||< C ||< 522.15 ||< K ||< [] ||
 * < Sigma-Aldrich ||< 248 - 250 ||< C ||< 522.15 ||< K ||< [|SUPELCO&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC] ||
 * < Alfa Aesar ||< 243 - 245 ||< ? ||< 517.15 ||< K ||< [] ||
 * < Science Lab ||< 248 ||< C ||< 521.15 ||< K ||< [] ||
 * CRC Handbook || 245 || C || 518.15 || K || [] ||


 * [Put in ChemInfo Sheet and I will grade it there JCB]**