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Methanol: a diagnostic tool for star formationLeurini, Silvia. Unknown Date (has links) (PDF)
University, Diss., 2004--Bonn.
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Physiology and biochemistry of primary alcohol oxidation in the gram-positive bacteria "amycolatopsis methanolica" and "bacillus methanolicus"Hektor, Harm Jan. January 1997 (has links)
Proefschrift Rijksuniversiteit Groningen. / Datum laatste controle: 03-06-1997. Auteursnaam op omslag: Hans Hektor. Lit.opg. - Met een samenvatting in het Nederlands.
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Computer Simulations of Water and Methanol in Carbon NanotubeWaghe, Aparna January 2007 (has links) (PDF)
No description available.
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Methanol as an automotive fuel : a summary of research in the M.I.T. Energy LaboratoryDonnelly, Richard George January 1976 (has links)
No description available.
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The origin of the ligand effect in supported and bulk metal oxide catalysis : in situ infrared, raman, UV-Vis DRS, and kinetic studies during methanol oxidation /Burcham, Loyd James. January 1999 (has links)
Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 281-284).
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Researches on methyl alcoholMenzies, Robert Charles January 1921 (has links)
No description available.
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Methanol amination using natural clinoptiloliteLevin, Lance Robin 10 September 2012 (has links)
M.Tech. / Clinoptilolite possesses acid and base properties, and is hydrothermally stable at high temperatures. It can be reactivated by simple oxidation, and is highly selective due to its unique-shape selectivity. It is also not harmful to the environment and it has shown benefits to soil as well (Mumpton,1977). An initial study of the reactions of methanol amination was done using both natural local and synthetic clinoptilolites. Characterization of each was done before and after modification using XRD, TPD and BET analysis. The BET analysis showed an increase in the surface area and pore diameter of both the natural and synthetic types after acid treatment and calcination. Most interesting of all was the large increase in surface area, where the natural type increased from 16 to 36.7 m 2/g after acid treatment and the synthetic type increased almost 13 times, from 2 to 27.7 m2/g after acid treatment. This effect had a strong influence on the selectivity of methylamines by allowing a larger surface area to be in contact with the feed reagents. The XRD of the treated and untreated natural and synthetic clinoptilolite were compared and discussed. The catalytic properties of zeolites depend on the treatment of clinoptilolite, and the characteristic peaks of natural and the acid treated form can be identified in the XRD plots.The TPD analyses showed that there were two acid sites associated with the clinoptilolite; one weak and one strong. The synthetic clinoptilolite weak acid site also showed a much lower ammonia uptake, than the natural clinoptilolite weak acid site. Clinoptilolite was shown to be successful as a catalyst for the production of dimethylamine with high selectivity. This was attributed to a transition state shape selectivity associated with the clinoptilolite channels. The natural clinoptilolite displayed good selectivities at 400°C and a 5:1 ratio of methanol to ammonia, and gave a high conversion of > 90% ammonia to amines. The synthetic clinoptilolite gave better conversions and lower TMA selectivity than the natural clinoptilolite over a large range of feed ratios and temperatures. This included conversions of over 90% for most ratios (at 400 and 450°C). The natural clinoptilolite gave better results than those obtained using the amorphous clinoptilolite, which is currently used in industry. For example, low TMA selectivity was observed when a ratio of 5:1 or greater (methanol to ammonia) was used. The TMA selectivity is still far lower than the thermodynamic equilibrium selectivities obtained without a catalyst (62%). The catalyst lifetime has been shown to deteriorate with time.
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Antibacterial properties of the methanol extract of helichrysum pedunculatumNcube, Nqobile S January 2008 (has links)
The methanol extract of Helichrisum pedunculatum was screened for antimicrobial activity up to a concentration of 5 mg/ml using the agar dilution technique. A number of test bacterial isolates, comprising both Gram negative and Gram positive organisms were susceptible to the crude extract of the plant. The minimum inhibitory concentrations (MICs) of the extract ranged between 1 and 5 mg/ml for the susceptible organisms. The MICs of the selected antibiotics, chloramphenicol and penicillin, ranged between 2 and 4 mg/L, and 2 and 32 mg/L respectively against Bacillus cereus, Proteus vulgaris and Staphylococcus aureus OKOH1. Bactericidal activity was determined by the time kill assay. The methanol extract of the plant was not bactericidal at 1 × MIC for B. cereus, P. vulgaris and Staph. aureus OKOH1. At 2 × MIC the extract was bacteriostatic against B. cereus but bactericidal against P. vulgaris and Staph. aureus OKOH1. Combination studies were done at 1/2 × MIC, 1 × MIC and 2 × MIC of the plant extract with 1 × MIC of the antibiotics. Combinations of the plant extract and chloramphenicol resulted in mostly indifferent interactions against P. vulgaris and Staph. aureus OKOH1 but synergistic interactions at higher concentration of the plant extract for B. cereus. Penicillin combinations gave synergistic interactions at lower concentrations of the plant for P.vulgaris and Staph. aureus OKOH1 but was mostly indifferent for B. cereus.
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Exploratory studies of photocyclization and photosolvolysis of biaryl methanolsShi, Yijian 26 July 2018 (has links)
The photocyclization and photosolvolysis of a series of hydroxy-substituted biaryl
methanols [special characters omitted] have been studied. The proposed mechanism involves
deprotonation of the HOAr moiety and heterolytic cleavage of the C-O bond of the
hydroxymethyl group [special characters omitted] in the first excited singlet state (S1), to give biaryl quinone
methide intermediates, which subsequently cyclize to the corresponding chromene product
and/or react with solvent to give the solvolysis product. The formation of these quinone
methide intermediates is facilitated by the excited state planarization and the subsequent
charge polarization (negative charge transferred from the HOAr ring into the [special characters omitted]
ring) of the biaryl. Although both of these processes are influenced by steric and
electronic factors, the latter turns out to have a more significant effect on reaction
efficiency.
When the geometry of the molecule goes from a twisted conformation to a more
planar form, the molecule becomes more conjugated and thus gains delocalization energy.
This energy is generally larger for the planarization in the S1 state than in the ground state.
When it is large enough to overcome the steric repulsion for twisting, biaryls can planarize
efficiently in the excited state, which is true for most biphenyl systems. However, it is
shown that the deprotonated forms [special characters omitted] of these biaryls have an even larger
driving force for S1 planarization than the neutral forms [special characters omitted]. Thus,
biaryls with naphthalene ring(s) joined at the 1-position which do not planarize efficiently
in the neutral form can still reach a more planar geometry after adiabatic deprotonation of
the phenolic hydroxy group in S1. That is, the photocyclization of these molecules
proceeds via initial adiabatic deprotonation from the twisted S1 state, followed by twisting
(to the planar form) and subsequent charge polarization which expels the hydroxy group at
the benzylic position [special characters omitted], to give the required quinone methide intermediate.
The o,o'-biaryl quinone methides derived from the o,o'-substituted biaryl methanols
are very short-lived due to rapid intramolecular ring closure and are therefore not
detectable by nanosecond laser flash photolysis. The o,p’- and p,p'-biphenyl quinone
methides, however, do not cyclize and as expected, are readily observable by nanosecond
laser flash photolysis. When the benzylic hydroxy group is replaced by other leaving
groups, the reaction can be used, in principle, as a photodeprotecting reaction and also to
photogenerate acid.
These and other results of the Thesis have uncovered many interesting mechanistic
details of this new class of reaction and hence have increased our general knowledge of
the excited state behavior of aromatic molecules. / Graduate
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Comparison of Conventional and Middle Vessel Batch Reactive Distillation Column: Application to Hydrolysis of Methyl Lactate to Lactic AcidEdreder, E.A., Mujtaba, Iqbal M., Emtir, M. January 2013 (has links)
No / Comparison of optimal operation between conventional batch reactive distillation column (CBRD) and middle-vessel batch reactive column (MVBRD) for the production of lactic acid via hydrolysis of methyl lactate has not been considered in the past. Therefore, it is the main focus in this work. A dynamic optimization problem incorporating a process model is formulated to minimize the batch time subject to constraints on the amount and purity of lactic acid. Control variables (reflux ratio or/and a reboil ratio) are treated as a piecewise constant. Optimization results indicate that MVBRD is more effective than CBRD in terms of saving in batch time which can be as high as of 20 %.
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