These are representative sample records from related to your search topic.
For comprehensive and current results, perform a real-time search at

3-pentanol: a new attractant present in volatile emissions from the ambrosia beetle, Megaplatypus mutatus.  


Megaplatypus mutatus (=Platypus mutatus) (Coleoptera: Platypodidae) is an ambrosia beetle that is native to South America. It attacks only standing live trees and causes severe stem breakage and death in commercial poplar (Populus) plantations. Previous work showed that male M. mutatus emits a sex pheromone composed mainly of (+)-sulcatol and sulcatone. We collected male volatile emissions during the hours of maximum emergence by using a specific polar microextraction phase; analyzed the extract by GC-MS; and tested the biological activity of selected compounds in the extract with a walking behavioral assay. Female M. mutatus emerged primarily between 7 and 11 h. In the chemical analyses of volatiles, a third compound, 3-pentanol, was identified in a small percentage of samples. Walking behavioral bioassays with video image analysis showed that at the doses tested, 3-pentanol elicited an attractive response from females. PMID:18850328

Gatti Liguori, Pablo; Zerba, Eduardo; Alzogaray, Raul A; Gonzalez Audino, Paola



Thermodynamic study of the n-octane-1-pentanol-sodium dodecyl sulfate solutions in water  

Microsoft Academic Search

The thermodynamic properties, PVTx (TS, PS, ?S), (?P\\/?T)VX, and CVVTx, of three microemulsions (water+n-octane+sodium dodecylsulfate+1-pentanol) with composition of solution-1: 0.0777 (H2O):0.6997 (n-C8H18):0.0777 (SDS):0.1449 (1-C5H11OH) mass fraction; solution-2: 0.6220 (H2O):0.1555 (n-C8H18):0.0777 (SDS):0.1448 (1-C5H11OH) mass fraction; and solution-3: 0.2720 (H2O):0.5054 (n-C8H18):0.0777 (SDS):0.1449 (1-C5H11OH) mass fraction were measured. Sodium dodecylsulfate (SDS) was used as an ionic surfactant, 1-pentanol used as stabilizer (cosurfactant), and

Nikolai G. Polikhronidi; Genadii V. Stepanov; Ilmutdin M. Abdulagatov; Rabiyat G. Batyrova



[In-situ research on Raman spectroscopy of 1-pentanol under high pressure].  


Raman spectra in 800-3 000 cm(-1) of 1-pentanol were studied under high pressure and at ambient temperature (23 degrees C) using a cubic zirconia anvil cell. The Raman peaks become sharper at higher pressure so that each individual C-H stretching mode is difficult to be distinguished. The Raman frequencies of the C-H stretching modes shift to a higher position with increasing pressures ranging between 0.1 MPa and 1.75 GPa. And the pressure induced frequency shifts are described by P(MPa) = 69.652 65 x (deltanu(p)) (single, T = 23 degrees C) + 105.806 93 where 0 < (deltanu(p)) single (cm(-1) < or = 23 and P(MPa) =77.974 04 x (Anu(p))( 2 960, T = 23 degrees 95.390 5 where 0 < (deltanu(p))2 960 (cm(-1)) < or = 21 and P(MPa) =126.956 39 x (deltanu(p)) (2 863, T = 23 degrees) -110.648 09 where 0 < (deltanu(p)) 2 863(cm(-1)) < or = 13, respectively. The global slope is (thetanu(single)/thetaP)T (14+/- 1) cm(-)1 x GPa(-1), which can be used as a pressure sensor. Both the jumping of the frequencies and the figure under microscope indicate that the frozen pressure of the 1-pentanol at room temperature is 1.75 GPa. The molar volume change of the 1-pentanol is deltaVm = 1.84 x 10(-6) m3 x mol(-1) in the phase transformation from a liquid to a solid at 23 degrees C. PMID:20545138

Tian, Feng; Zheng, Hai-Fei



Thermal decomposition of 1-pentanol and its isomers: a theoretical study.  


Pentanol is one of the promising "next generation" alcohol fuels with high energy density and low hygroscopicity. In the present work, dominant reaction channels of thermal decomposition of three isomers of pentanol: 1-pentanol, 2-methyl-1-butanol, and 3-methyl-1-butanol were investigated by CBS-QB3 calculations. Subsequently, the temperature- and pressure-dependent rate constants for these channels were computed by RRKM/master equation simulations. The difference between the thermal decomposition behavior of pentanol and butanol were discussed, while butanol as another potential alternative alcohol fuel has been extensively studied both experimentally and theoretically. Rate constants of barrierless bond dissociation reactions of pentanol isomers were treated by the variational transition state theory. The comparison between various channels revealed that the entropies of variational transition states significantly impact the rate constants of pentanol decomposition reactions. This work provides sound quality kinetic data for major decomposition channels of three pentanol isomers in the temperature range of 800-2000 K with pressure varying from 7.6 to 7.6 × 10(4) Torr, which might be valuable for developing detailed kinetic models for pentanol combustion. PMID:22909118

Zhao, Long; Ye, Lili; Zhang, Feng; Zhang, Lidong



Exploring the discrepancies between experiment, theory, and simulation for the homogeneous gas-to-liquid nucleation of 1-pentanol  

NASA Astrophysics Data System (ADS)

Using an efficient Monte Carlo approach known as Aggregation-Volume-bias Monte Carlo with self-adaptive Umbrella Sampling and Histogram Reweighting (AVUS-HR), we obtained the nucleation free energy profile of 1-pentanol at various temperatures from 220 to 360 K. From these profiles, differences between the free energy barrier heights obtained from our simulations and those predicted by the classical nucleation theory (CNT) were calculated. Our results strongly support that the logarithm of the nucleation rate ratio between simulation (or experiment) and CNT increases almost linearly with the inverse temperature. Among the various factors that contribute to the discrepancy between simulation and CNT nucleation rates, the nonzero surface free energy of the monomer included in the CNT makes the largest contribution. On the molecular level, the simulations indicate that a gas-phase cluster of 1-pentanol molecules is relatively compact and can contain multiple hydrogen bonded aggregates of various sizes and that this aggregate size distribution depends strongly on temperature and also on the overall size of the cluster system.

Nellas, Ricky B.; Keasler, Samuel J.; Siepmann, J. Ilja; Chen, Bin



Excess parameters for binary mixtures of ethyl benzoate with 1-propanol, 1-butanol and 1-pentanol at T=303, 308, 313, 318, and 323 K  

NASA Astrophysics Data System (ADS)

Various thermo-acoustic parameters, such as excess isentropic compressibility (KsE), excess molar volume (VE), excess free length (LfE), excess Gibb's free energy (?G*E), and excess Enthalpy (HE), have been calculated from the experimentally determined data of density, viscosity and speed of sound for the binary mixtures of ethyl benzoate+1-propanol, or +1-butanol, or +1-pentanol over the entire range of composition at different temperatures (303, 308, 313, 318 and 323 K). The excess functions have been fitted to the Redlich-Kister type polynomial equation. The deviations for excess thermo-acoustic parameters have been explained on the basis of the intermolecular interactions present in these binary mixtures.

Sreehari Sastry, S.; Babu, Shaik; Vishwam, T.; Parvateesam, K.; Sie Tiong, Ha.



Dependence on molecular parameters of the heat capacity critical behaviour for nitroalkane + alcohol binary systems  

NASA Astrophysics Data System (ADS)

Heat capacities per unit volume for a set of nitroalkane + alcohol critical mixtures near their upper consolute point are presented. The selected nitroalkanes were nitromethane and nitroethane whereas the 1-alcohol series from 1-propanol to 1-decanol was studied. The critical anomaly of nitroalkane + non-primary alcohols was also investigated; 2-propanol, 2-pentanol, 3-pentanol and 5-nonanol were chosen to this end. The heat capacity data are obtained at atmospheric pressure as a function of temperature in the homogeneous and heterogeneous regions by means of a differential scanning calorimeter. The exponent and amplitudes that characterises the observed critical anomaly are determined from experimental data, being their values coherent with previous results. In addition, the critical amplitude of the correlation length was calculated using the universality of the two-scale factor. Finally, the changes in the critical parameters as a function of the molecular structure of both nitroalkane and alcohol are analysed.

Souto-Caride, M.; Troncoso, J.; Losada-Pérez, P.; Peleteiro, J.; Carballo, E.; Romani, L.



Composition and Process for Retarding the Premature Aging of PMR Monomer Solutions and PMR Prepegs  

NASA Technical Reports Server (NTRS)

Polyimides are derived from solutions of at least one low-boiling organic solvent, e.g. isopropanol containing a mixture of polyimide-forming monomers. The monomeric solutions have an extended shelf life at ambient (room) temperatures as high as 80 C, and consist essentially of a mixture of monoalkyl ester-acids, alkyl diester-diacids and aromatic polyamines wherein the alkyl radicals of the esteracids are derived from lower molecular weight aliphatic secondary alcohols having 3 to 5 carbon atoms per molecule such as isopropanol, secondary butanol, 2-methyl-3-butanol, 2 pentanol or 3-pentanol. The solutions of the polyimide-forming monomers have a substantially improved shelf-life and are particularly useful in the aerospace and aeronautical industry for the preparation of polyimide reinforced fiber composites such as the polyimide cured carbon composites used in jet engines, missiles, and for other high temperature applications.

Alston, William B. (Inventor); Gahn, Gloria S. (Inventor)



Experimental neurotoxicity and urinary metabolites of the C5-C7 aliphatic hydrocarbons used as glue solvents in shoe manufacture.  


Rats were intermittently exposed (9 to 10 h/d, 5 to 6 d/week) to controlled concentrations of single analytical grad solvents in ambient air. After periods ranging from 7 to 30 weeks the animals were perfused with glutaraldehyde and samples of nerves were processed for light microscopy of sections and of teased fibers. Animals treated with n-hexane at 5000 ppm (14 weeks) or 2500 ppm (30 weeks) developed the typical giant axonal degeneration already described in rats treated continuously with 400 to 600 ppm of the same solvent for 7 weeks or more. No such alterations were found in rats subjected to the following intermittent respiratory treatments: n-hexane 500 ppm (30 weeks) or 1500 ppm (14 weeks), cyclohexane 1500 or 2500 (30 weeks), n-pentane 3000 ppm (30 weeks), n-heptane 1500 ppm (30 weeks), 2-methylpentane 1500 ppm (14 weeks), and 3-methylpentane 1500 ppm (14 weeks). The following metabolites were found in the urine of rats according to treatment (in parenthesis): 2-methyl-2-pentanol (2-methylpentane); 3-methyl-2-pentanol and 3-methyl-3-pentanol (3-methylpentane), 2-hexanol, 3-hexanol, gamma-valerolactone, 2,5-dimethylfuran, and 2,5-hexanedione (n-hexane). 2-Hexanol was found to be the main urinary metabolite of n-hexane, while 2,5-hexanedione was present only in a lesser proportion. This feature of rat metabolism suggests that in this species 2,5-hexanedione reaches an effective level at its site of action during intermittent respiratory treatment with n-hexane with difficulty and explains the high concentrations necessary to cause polyneuropathy in rats subjected to this treatment. PMID:6277548

Frontali, N; Amantini, M C; Spagnolo, A; Guarcini, A M; Saltari, M C; Brugnone, F; Perbellini, L



[Metabolism and toxicity of n-pentane and isopentane].  


n-Pentane and isopentane have a wide range of use, for example, for cleaning precision machinery, extracting essence and oil, and as liquid fuel for now very popular disposable lighters. They are contained in liquefied petroleum gas and natural gas as trace constituents. In our present experiments, we studied the metabolism and toxicity of these n-pentane and isopentane metabolites. Male mice of ICR strain were exposed to about 5% n-pentane for one hour while the oxygen in the environmental air was maintained at about 20%. Then their blood and liver tissue were collected and analyzed by means of GC and GC-MS. The metabolites thus obtained were 2-pentanol, 3-pentanol and 2-pentanone. The same procedure was repeated with isopentane; 3-methyl-2-butanol, 2-methyl-2-butanol and 3-methyl-2-butanone were detected as the resultant metabolites. In the presence of the NADPH-generating system liver microsomes were made to react to the substrate of saturated n-pentane or isopentane aqueous solution at 37 degrees C for one hour. As a result, the same metabolites were produced as obtained in the exposure experiment. It was therefore suggested that n-pentane and isopentane were metabolized chiefly by liver microsomes. Male mice of ICR strain were fed with 80 mg/kg b.w. of phenobarbital for consecutive four days and exposed to n-pentane or isopentane for one hour. This resulted in an increase in the amount of 2-pentanol and 2-pentanone in the n-pentane inhalation and 2-methyl-2-butanol in the isopentane inhalation experiment. The toxicity of each metabolite was studied on cultured cells. The metabolites were individually mixed with HeLa S3 cell suspension, incubated for three days, and their concentration which inhibited the growth of cells by 50% (IGC 50) were compared. It was demonstrated as a result that the IGC 50 for any of the metabolites was lower than that for methanol, ethanol or acetone used as control. PMID:1920919

Chiba, S; Oshida, S



Characteristics of chemical binding to alpha 2u-globulin in vitro--evaluating structure-activity relationships  

SciTech Connect

alpha 2u-Globulin (alpha 2u) has been shown to accumulate in the kidneys of male rats treated with 2,2,4-trimethylpentane (TMP). 2,4,4-Trimethyl-2-pentanol (TMP-2-OH), a metabolite of TMP, is found reversibly bound to alpha 2u isolated from the kidneys of these treated rats. The objectives of the following study were to characterize the ability of (3H)TMP-2-OH to bind to alpha 2u in vitro and to determine whether other compounds that cause this protein to accumulate have the same binding characteristics. Although compounds that have been shown to cause the accumulation of alpha 2u in male rat kidneys compete in vitro with (3H)TMP-2-OH for binding to alpha 2u, they do so to varying degrees. The binding affinity (Kd) of the (3H)TMP-2-OH-alpha 2u complex was calculated to be on the order of 10(-7) M. The inhibition constant values (Ki) determined for d-limonene, 1,4-dichlorobenzene, and 2,5-dichlorophenol were all in the range 10(-4) M, whereas the Ki values for isophorone, 2,4,4- or 2,2,4-trimethyl-1-pentanol, and d-limonene oxide were determined to be in the range 10(-6) and 10(-7) M, respectively. TMP and 2,4,4- and 2,2,4-trimethylpentanoic acid did not compete for binding. This suggests that other factors, besides binding, are involved in the accumulation of alpha 2u. In this study the ability of a chemical to bind to alpha 2u was used as a measure of biological activity to assess structure-activity relationships among the chemicals tested and known to cause the accumulation of alpha 2u. The results so far suggest that binding is dependent on both hydrophobic interactions and hydrogen bonding.

Borghoff, S.J.; Miller, A.B.; Bowen, J.P.; Swenberg, J.A. (Chemical Industry Institute of Toxicology, Research Triangle Park, NC (USA))



JASPERSE CHEM 360 TEST 1 VERSION 3 Reactions involving Alcohols  

E-print Network

1 JASPERSE CHEM 360 TEST 1 VERSION 3 Reactions involving Alcohols 1. 2-Methyl-3-pentanol is classified as: (3 points) a. a primary alcohol b. a secondary alcohol c. a tertiary alcohol d. none;6 10. Design syntheses of the following, starting from alcohols of 4 carbons. (7 points each) O #12;

Jasperse, Craig P.


Removal of PAHs from highly contaminated soils found at prior manufactured gas operations.  


Removal of PAHs from highly contaminated soil found at a manufactured gas site was evaluated using solvent washing with mixed solvents. The following solvents were considered as water miscible co-solvents in mixed solvents: ethanol, 2-propanol, acetone, and 1-pentanol. In batch solvent extraction of soil, ethanol and 2-propanol were selected as primary components of mixed solvents in addition to 1-pentanol. Using ternary solutions containing either ethanol or 2-propanol with a volume fraction of 1-pentanol ranging from 5 to 25% and a water volume fraction ranging from 5 to 30%, ethanol was more effective than 2-propanol in extracting PAHs from soil. A solvent mixture of 5% 1-pentanol, 10% water and 85% ethanol was selected as the extraction solvent. Using a 1g:4ml soil:solvent extraction ratio, extraction kinetics showed that from 65 to 90% of the extractable PAHs were removed within an hour of contact between soil and solvent. Using this 1g:4ml extraction ratio, PAHs were removed in a three-stage cross-current solvent washing process where the same batch of soil was extracted with clean solvent for 1h in each stage. PAH removals in three-stage cross-current solvent washing were comparable to PAH removals obtained with Soxhlet extraction. PMID:11080576

Khodadoust, A P; Bagchi, R; Suidan, M T; Brenner, R C; Sellers, N G



Comparative Experiments of Protein Denaturation for Studying Structural Difference of Homologous Membrane Proteins: P-450scc and P-45011?  

NASA Astrophysics Data System (ADS)

The topological difference between two homologous membrane proteins, cytochromes P-450scc and P-45011 ? in the inner membrane of bovine adrenocortical mitochondria, was studied by denaturation experiments, using urea and 1-pentanol as denaturants. Both P-450s denatured at the urea concentration of about 2.5 M that is in the concentration range of the denaturation of soluble proteins. In contrast, P-45011 ? was denatured by 1-pentanol, which is an efficient denaturant of membrane proteins, at a much lower concentration than P-450scc. These results suggested that the membrane domain is more strongly coupled with the soluble functional domain in P-45011 ? than P-450scc. It was also indicated that the comparative experiments of protein denaturation by urea and alcohol provide a simple method to identify the structural difference of homologous membrane proteins.

Suzuki-Tomii, Keiko; Ohta, Yoshihiro; Kawato, Suguru; Mitaku, Shigeki



Liquid phase hydrogenation of citral: suppression of side reactions  

Microsoft Academic Search

Selective hydrogenation of citral was investigated at 70°C in four different alcohols over Ru, Rh and Ni supported catalysts. The main aim was to suppress the side reaction, like acetalization and cyclization of citronellal. Acetalization could be suppressed either by using chloride-free catalyst precursors and other supports than active carbon or by using longer chained alcohols, like 2-pentanol and 2-methyl-2-propanol

Päivi Mäki-Arvela; Lasse-Pekka Tiainen; Ahmad Kalantar Neyestanaki; Rainer Sjöholm; Tiina-Kaisa Rantakylä; Ensio Laine; Tapio Salmi; Dmitry Yu Murzin



Liquid-phase hydrogenation of citral for production of citronellol: catalyst selection  

Microsoft Academic Search

Selective hydrogenation of citral to citronellol has been investigated over Ni supported catalysts. The aim was to compare different support materials and catalyst preparation methods. Selectivity to citronellol was dependent on conversion. The highest maximum selectivity towards citronellol for a Ni\\/Al2O3 (16.7wt.% Ni) catalyst at 2.3bar hydrogen increased from 70% in ethanol to 85% 2-pentanol, where acetalisation could be totally

P Mäki-Arvela; L.-P Tiainen; M Lindblad; K Demirkan; N Kumar; R Sjöholm; T Ollonqvist; J Väyrynen; T Salmi; D. Yu Murzin



Effect of surfactants and cosurfactants on the phase separation temperature and volatility of methanol\\/hydrocarbon\\/water blends  

Microsoft Academic Search

The effects of several surfactants and cosurfactants on the phase separation temperature and Reid vapor pressure of methanol\\/hydrocarbon\\/water blends were investigated. The surfactants studied were oleic acid, heptanoic acid, and four commercial nonylphenoxypoly(ethyleneoxy)ethanol surfactants (GAF Igepal CO-210, CO-430, CO-520, and CO-530). The cosurfactants studied were 1- and 2-pentanol. A simulated fuel consisting of a 50\\/50 vol % mixture of 2,2,4-trimethylpentane

Singgih Nitirahardjo; H. M. Cheung



Hydrated electrons in water-in-oil microemulsion: a pulse radiolysis study  

NASA Astrophysics Data System (ADS)

Half-life and yield of hydrated electron in water-in-oil microemulsion of cetyl trimethylammonium bromide-water-1-pentanol-cyclohexane system has been studied. Dose distribution calculation suggests scavenging of electrons that are generated in cyclohexane by water pools and hydroxyl radical generation by direct water radiolysis only. Dose distribution, half-life of e aq-, generation and solvation of e aq- in this system and its comparison with other systems have been discussed.

Joshi, Ravi; Mukherjee, T.



Comparative Experiments of Protein Denaturation for Studying Structural Difference of Homologous Membrane Proteins: P-450scc and P-45011beta  

Microsoft Academic Search

The topological difference between two homologous membrane proteins, cytochromes P-450scc and P-45011 beta in the inner membrane of bovine adrenocortical mitochondria, was studied by denaturation experiments, using urea and 1-pentanol as denaturants. Both P-450s denatured at the urea concentration of about 2.5 M that is in the concentration range of the denaturation of soluble proteins. In contrast, P-45011 beta was

Keiko Suzuki-Tomii; Yoshihiro Ohta; Suguru Kawato; Shigeki Mitaku



Chiral lithium amido sulfide ligands for asymmetric addition reactions of alkyllithium reagents to aldehydes  

Microsoft Academic Search

Six chiral amino sulfides have been synthesised from the amino acids phenylalanine, phenylglycine and valine. These amino sulfides were used as chiral ligands in the asymmetric addition of n-butyllithium and metyllithium to various aldehydes at low temperatures. The highest stereoselectivities were obtained with benzaldehyde, resulting in 1-phenyl-1-pentanol and 1-phenyl-1-ethanol in enantiomeric excesses of >98.5 and 95%, respectively. These stereoselectivities were

Johan Granander; Richard Sott; Göran Hilmersson



New Chemical Attractants for Trapping Lacanobia subjuncta, Mamestra configurata, and Xestia c-nigrum (Lepidoptera: Noctuidae)  

Microsoft Academic Search

Significant numbers of 3 pest species of noctuid moths were captured in traps baited with acetic acid, 3-methyl-1-butanol, and 3-methyl-1-pentanol. These were Lacanobia subjuncta (Grote & Robinson); Mamestra configurata Walker, bertha armyworm; and Xestia c-nigrum (L.), spotted cutworm. The combination of acetic acid and 3-methyl-1-butanol was superior to the individual chemicals in attracting all 3 species, whereas the combination of

Peter J. Landolt



Room temperature synthesis and optical properties of SrMoO 4 crystallites by w\\/o microemulsion  

Microsoft Academic Search

SrMoO4 crystallites with varying morphology have been prepared by the chemical reaction of strontium chloride and sodium molybdate in a reverse microemulsion system consisting of water, OP (p-octyl polyethylene glycol phenylether, non-ionic surfactant), 1-pentanol (co-surfactant) and cyclohexane (oil). The resultant powders were characterized in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and photoluminescent spectra

Jun Liu; Junfeng Ma; Botao Lin; Yang Ren; Xiaohui Jiang; Jiantao Tao; Xiaoyi Zhu



Synthesis of YPO 4 Nanoparticals vis Microemulsion Method and Its Friction Properties of Lubricating Oils  

Microsoft Academic Search

\\u000a Yttrium phosphate nanoparticles are preparedby precipitation in reverse microemulsions which used the cyclohexane as oil phase,\\u000a the Txiton X-100, CTAB, 1-Pentanol as surfactant and cosurfactant phase, and an aqueous Y(NO3)3 and Na3PO4 solution as the water phase. YPO4 particles obtained by file classical microemulsion method are found to be monodisperse amorphous spheres with the diameter\\u000a of about 40 ran. Transmission

Limin Zhao; Xin Shao; Yibin Yin; Wenzhi Li


A rhodamine-deoxylactam based sensor for chromo-fluorogenic detection of nerve agent simulant.  


N-(rhodamine B)-deoxylactam-5-amino-1-pentanol (dRB-APOH) was designed and prepared as the chromo-fluorogenic sensor for detection of a nerve agent simulant via analyte triggered tandem phosphorylation and opening of the intramolecular deoxylactam. The successful detection of diethyl chlorophosphate suggests the utility of rhodamine-deoxylactams as the chromo-fluorogenic signal reporting platform for design of sensors targeting reactive chemical species via various chemistries. PMID:22995618

Wu, Zhisheng; Wu, Xuanjun; Yang, Yuhui; Wen, Ting-bin; Han, Shoufa



Study of Dipolar Association in Binary System Acetyl Acetone in Aliphatic Alcohols  

NASA Astrophysics Data System (ADS)

The dielectric constant (\\varepsilonm) of binary mixtures of acetylacetone (HAA) with aliphatic alcohols viz. 1-pentanol, 1-butanol, 1-propanol has been measured at temperature 303.16 K and frequency 455 kHz. The data of dielectric constant are used to compute mutual correlation factor (gab), excess molar polarization (? P) and excess free energy of mixing (? Gab) to study the molecular interaction. The study reveals that interaction is maximum for HAA + pentanol system and microheterogeneous ?-clusters with antiparallel orientation of dissimilar molecules predominate in it.

Acharya, Swaroop; Mishra, Sarmistha; Mohanty, Gouranga Charan



Regioselective alkane hydroxylation with a mutant CYP153A6 enzyme  


Cytochrome P450 CYP153A6 from Myobacterium sp. strain HXN1500 was engineered using in-vivo directed evolution to hydroxylate small-chain alkanes regioselectively. Mutant CYP153A6-BMO1 selectively hydroxylates butane and pentane at the terminal carbon to form 1-butanol and 1-pentanol, respectively, at rates greater than wild-type CYP153A6 enzymes. This biocatalyst is highly active for small-chain alkane substrates and the regioselectivity is retained in whole-cell biotransformations.

Koch, Daniel J.; Arnold, Frances H.



Synthesis and tautomerization of hydroxylated isoflavones bearing heterocyclic hemi-aminals.  


The aminomethylation of hydroxylated isoflavones with 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, and 5-amino-1-pentanol in the presence of excess formaldehyde led principally to 9-(2-hydroalkyl)-9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]-oxazin-4-ones 4 and/or the tautomeric 7-hydroxy-8-(1,3-oxazepan-3-ylmethyl)-4H-chromen-4-ones 5. The ratio of these tautomers was dependent on solvent polarity, electronic effects of aryl substituents in the isoflavone and the structure of the amino alcohol. NMR studies confirmed the interconversion of tautomeric forms. PMID:25412895

Frasinyuk, Mykhaylo S; Bondarenko, Svitlana P; Khilya, Volodymyr P; Liu, Chunming; Watt, David S; Sviripa, Vitaliy M



Effect of release rate and enantiomeric composition on response to pheromones of Megaplatypus mutatus (Chapuis) in poplar plantations of Argentina and Italy.  


Megaplatypus mutatus (=Platypus sulcatus Chapuis) is an Ambrosia beetle native to South America, which was recently introduced in Italy and its presence there is causing severe damage to the local poplar plantations. The male M. mutatus pheromone is composed of (S)-(+)-6-methyl-5-hepten-2-ol [(+)-sulcatol], 6-methyl-5-hepten-2-one (sulcatone) and 3-pentanol. A series of field trials testing dose, blend and enantiomer composition performed in Argentina and Italy evaluated attraction and found that the optimal release rate of pheromone components as baits in cross vane baited traps (CIPEIN-CV) was 6, 6 and 30 mg day?1 of sulcatone, (+)-sulcatol and 3-pentanol, respectively. It was also determined that racemic sulcatol is as effective as the pure (+)-isomer for the purpose of beetle catch, due to the inert nature of the (?)-isomer allowing the usage of low cost racemic sulcatol instead of highly expensive (+)-sulcatol. The results of our work contribute to the development of pheromone-based local technologies with low environmental impact and low cost for control or monitoring of an important pest. PMID:23590828

Funes, Hernán; Zerba, Eduardo; Gonzalez-Audino, Paola



Diffusion cloud chamber operation and the background gas effect  

NASA Astrophysics Data System (ADS)

Key design and operational aspects for thermal diffusion cloud chamber (TDCC) applications are discussed in the context of a two-dimensional solution to the mass and energy balances describing diffusion through a stagnant background gas. The important issue of buoyancy-driven convective disturbances and their impact upon nucleation measurements made using a diffusion cloud chamber are discussed. A new derivation of the relation that predicts the upper limit of total pressure allowed for stable (the absence of buoyancy-driven convective disturbances) operation of the diffusion cloud chamber is presented. For the first time, this limit of stable operation can be predicted prior to making experimental measurements. Nucleation data obtained in our laboratory are examined in the context of this predicted limit of stable operation. New nucleation data are presented for 1-pentanol using helium as a background gas. Only data corresponding to stable operation in the cloud chamber is used in the analysis. The effect of background gas on nucleation we have reported previously is confirmed for 1-pentanol, as well as for all the other alcohols that have been investigated in our laboratory.

Bertelsmann, Anne; Heist, Richard H.


Correlation and prediction of thermodynamic properties of binary mixtures from perturbed chain statistical associating fluid theory  

NASA Astrophysics Data System (ADS)

Densities and viscosities for binary mixtures of Diethanolamine (DEA) + 2 alkanol (2 propanol up to 2 pentanol) were measured over the entire composition range and temperature interval of 293.15-323.15 K. From the density and viscosity data, values of various properties such as isobaric thermal expansibility, excess isobaric thermal expansibility, partial molar volumes, excess molar volumes and viscosity deviations were calculated. The observed variations of these parameters, with alkanols chain length and temperature, are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures. The ability of the perturbed chain statistical associating fluid theory (PC-SAFT) to correlate accurately the volumetric behavior of the binary mixtures is demonstrated.

Almasi, Mohammad



Bioethanol Production Optimization: A Thermodynamic Analysis  

NASA Astrophysics Data System (ADS)

In this work, the phase equilibrium of binary mixtures for bioethanol production by continuous extractive process was studied. The process is composed of four interlinked units: fermentor, centrifuge, cell treatment unit, and flash vessel (ethanol-congener separation unit). A proposal for modeling the vapor-liquid equilibrium in binary mixtures found in the flash vessel has been considered. This approach uses the Predictive Soave-Redlich-Kwong equation of state, with original and modified molecular parameters. The congeners considered were acetic acid, acetaldehyde, furfural, methanol, and 1-pentanol. The results show that the introduction of new molecular parameters r and q in the UNIFAC model gives more accurate predictions for the concentration of the congener in the gas phase for binary and ternary systems.

Álvarez, Víctor H.; Rivera, Elmer Ccopa; Costa, Aline C.; Filho, Rubens Maciel; Maciel, Maria Regina Wolf; Aznar, Martín


Optical constants of alcohols in the infrared  

NASA Technical Reports Server (NTRS)

The spectral reflectances at near-normal incidence for methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol are reported for the spectral range 6700-350 kaysers. The real and imaginary parts of the complex index of refraction of these liquids are obtained in the range 4000-400 kaysers by use of Kramers-Kronig phase-shift analysis. For all of the alcohols studied, the strength for the OH-stretch bands is directly proportional to the number of OH groups per unit volume; similar relations are established for CH- and CO-stretch bands. Absorption cross sections for stretch vibrations of the three groups are considered, and the role of characteristic group intensities in intensity spectroscopy is discussed.

Sethna, P. P.; Williams, D.



Bioethanol production optimization: a thermodynamic analysis.  


In this work, the phase equilibrium of binary mixtures for bioethanol production by continuous extractive process was studied. The process is composed of four interlinked units: fermentor, centrifuge, cell treatment unit, and flash vessel (ethanol-congener separation unit). A proposal for modeling the vapor-liquid equilibrium in binary mixtures found in the flash vessel has been considered. This approach uses the Predictive Soave-Redlich-Kwong equation of state, with original and modified molecular parameters. The congeners considered were acetic acid, acetaldehyde, furfural, methanol, and 1-pentanol. The results show that the introduction of new molecular parameters r and q in the UNIFAC model gives more accurate predictions for the concentration of the congener in the gas phase for binary and ternary systems. PMID:18418747

Alvarez, Víctor H; Rivera, Elmer Ccopa; Costa, Aline C; Filho, Rubens Maciel; Wolf Maciel, Maria Regina; Aznar, Martín



Solvent optimization for niacinamide adsorption on organo-functionalized SBA-15 mesoporous silica  

NASA Astrophysics Data System (ADS)

This work describes the application of organo-modified SBA-15 siliceous materials as the carrier for niacinamide. The surface functionalization of SBA-15 by a grafting strategy with triethoxyphenylsilane, triethoxy(4-methoxyphenyl)silane, triethoxymethylsilane and (3-mercaptopropyl)trimethoxysilane as modifying agents has been successfully achieved. The adsorption process was performed in acetonitrile, methanol, 2-propanol, 1-pentanol and ethyl acetate. The obtained results indicated a promote niacinamide adsorption on sulfopropyl-modified (119 mg/g) and non-modified (78 mg/g) SBA-15 from ethyl acetate. The pure and derivatized SBA-15 products have been characterized by elemental analysis, thermogravimetry, nitrogen adsorption and diffuse reflectance UV spectroscopy. After niacinamide adsorption the textural parameters of mesoporous carriers such as BET surface area, pore volume and microporosity were reduced. The mesoporous matrices loaded with niacinamide exhibited prolonged-release kinetics of this vitamin, especially from sulfopropyl-modified SBA-15 carrier.

Moritz, Micha?



Fluorous solvent for cell culture  

Microsoft Academic Search

Incubation of mouse melanoma B16 cells in fluorous solvents with low boiling point such as perfluoromethylcyclohexane, 1,1,1,3,3,3-hexafluoro-2-propanol, ethylpentafluoropropionate resulted in cell death. However, cells lived up to 2 days in fluorous alcohols such as 2,2,3,3,4,4,5,5-octafluoro-1-pentanol and 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexanol with relatively higher fluorine content. Remarkably, cells survived deprived of nutrition up to 4 days when incubated in 2,2,3,3,4,4,5,5,6,6,6-undecafluoro-1-hexanol or in 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptanol that

Maria Carmelita Z. Kasuya; Xiaonan Wen; Kenichi Hatanaka; Kageyasu Akashi



The stereoselectivity and catalytic properties of Xanthobacter autotrophicus 2-[(R)-2-Hydroxypropylthio]ethanesulfonate dehydrogenase are controlled by interactions between C-terminal arginine residues and the sulfonate of coenzyme M.  


2-[(R)-2-Hydroxypropylthio]ethanesulfonate (R-HPC) dehydrogenase (DH) catalyzes the reversible oxidation of R-HPC to 2-(2-ketopropylthio)ethanesulfonate (2-KPC) in a key reaction in the bacterial conversion of chiral epoxides to beta-keto acids. R-HPCDH is highly specific for the R-enantiomer of HPC, while a separate enzyme, S-HPCDH, catalyzes the oxidation of the corresponding S-enantiomer. In the present study, the features of substrate and enzyme imparting stereospecificity have been investigated for R-HPCDH. S-HPC was a substrate for R-HPCDH with a K(m) identical to that for R-HPC but with a k(cat) 600 times lower. Achiral 2-propanol and short-chain (R)- and (S)-2-alkanols were substrates for R-HPCDH. For (R)-alkanols, as the carbon chain length increased, K(m) decreased, with the K(m) for (R)-2-octanol being 1700 times lower than for 2-propanol. At the same time, k(cat) changed very little and was at least 90% lower than k(cat) for R-HPC and at least 22 times higher than k(cat) for S-HPC. (S)-2-Butanol and (S)-2-pentanol were substrates for R-HPCDH. The K(m) for (S)-2-butanol was identical to that for (R)-2-butanol, while the K(m) for (S)-2-pentanol was 7.5 times higher than for (R)-2-pentanol. Longer chain (S)-2-alkanols were sufficiently poor substrates for R-HPCDH that kinetic parameters could not be determined. Mutagenesis of C-terminal arginine residues of R-HPCDH revealed that R152 and R196 are essential for effective catalysis with the natural substrates R-HPC and 2-KPC but not for catalysis with 2-alkanols or ketones as substrates. Short-chain alkylsulfonates and coenzyme M (2-mercaptoethanesulfonate) were found to modify the kinetic parameters for 2-butanone reduction by R-HPCDH in a saturable fashion, with the general effect of increasing k(cat), decreasing K(m), and increasing the enantioselectivity of 2-butanone reduction to a theoretical value of 100% (S)-2-butanol. The modulating effects of ethanesulfonate and propanesulfonate provided thermodynamic binding constants close to K(m) for the natural substrates R-HPC and 2-KPC. The effects of alkylsulfonates on modulating the enantioselectivity and kinetic properties of R-HPCDH were abolished in R152A and R196A mutants but not in mutants of other C-terminal arginine residues. Collectively, the results suggest that interactions between the sulfonate of CoM and specific arginine residues are key to the enantioselectivity and catalytic efficiency of R-HPCDH. A model is proposed wherein sulfonate-arginine interactions within an alkylsulfonate binding pocket control the catalytic properties of R-HPCDH. PMID:15157110

Clark, Daniel D; Boyd, Jeffrey M; Ensign, Scott A



Synthesis of Short-Chain Diols and Unsaturated Alcohols from Secondary Alcohol Substrates by the Rieske Nonheme Mononuclear Iron Oxygenase MdpJ  

PubMed Central

The Rieske nonheme mononuclear iron oxygenase MdpJ of the fuel oxygenate-degrading bacterial strain Aquincola tertiaricarbonis L108 has been described to attack short-chain tertiary alcohols via hydroxylation and desaturation reactions. Here, we demonstrate that also short-chain secondary alcohols can be transformed by MdpJ. Wild-type cells of strain L108 converted 2-propanol and 2-butanol to 1,2-propanediol and 3-buten-2-ol, respectively, whereas an mdpJ knockout mutant did not show such activity. In addition, wild-type cells converted 3-methyl-2-butanol and 3-pentanol to the corresponding desaturation products 3-methyl-3-buten-2-ol and 1-penten-3-ol, respectively. The enzymatic hydroxylation of 2-propanol resulted in an enantiomeric excess of about 70% for the (R)-enantiomer, indicating that this reaction was favored. Likewise, desaturation of (R)-2-butanol to 3-buten-2-ol was about 2.3-fold faster than conversion of the (S)-enantiomer. The biotechnological potential of MdpJ for the synthesis of enantiopure short-chain alcohols and diols as building block chemicals is discussed. PMID:22752178

Schäfer, Franziska; Schuster, Judith; Würz, Birgit; Härtig, Claus; Harms, Hauke; Müller, Roland H.



Electrophysiological and Behavioral Responses of Male Fall Webworm Moths (Hyphantria cunea) to Herbivory-Induced Mulberry (Morus alba) Leaf Volatiles  

PubMed Central

Volatile organic compounds (VOCs) were collected from damaged and intact mulberry leaves (Morus alba L., Moraceae) and from Hyphantria cunea larvae by headspace absorption with Super Q columns. We identified their constituents using gas chromatography-mass spectrometry, and evaluated the responses of male H. cunea antennae to the compounds using gas chromatography-flame ionization detection coupled with electroantennographic detection. Eleven VOC constituents were found to stimulate antennae of male H. cunea moths: ?-ocimene, hexanal, cis-3-hexenal, limonene, trans-2-hexenal, cyclohexanone, cis-2-penten-1-ol, 6-methyl-5-hepten-2-one, 4-hydroxy-4-methyl-2-pentanone, trans-3-hexen-1-ol, and 2,4-dimethyl-3-pentanol. Nine of these chemicals were released by intact, mechanically-damaged, and herbivore-damaged leaves, while cis-2-penten-1-ol was released only by intact and mechanically-damaged leaves and ?-ocimene was released only by herbivore-damaged leaves. Results from wind tunnel experiments conducted with volatile components indicated that male moths were significantly more attracted to herbivory-induced volatiles than the solvent control. Furthermore, male moths' attraction to a sex pheromone lure was increased by herbivory-induced compounds and ?-ocimene, but reduced by cis-2-penten-1-ol. A proof long-range field trapping experiment showed that the efficiency of sex pheromone lures in trapping male moths was increased by ?-ocimene and reduced by cis-2-penten-1-ol. PMID:23166622

Tang, Rui; Zhang, Jin Ping; Zhang, Zhong Ning



Two Volatile Organic Compounds Trigger Plant Self-Defense against a Bacterial Pathogen and a Sucking Insect in Cucumber under Open Field Conditions.  


Systemic acquired resistance (SAR) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC)-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields. PMID:23698768

Song, Geun Cheol; Ryu, Choong-Min



Electrophysiological and behavioral responses of male fall webworm moths (Hyphantria cunea) to Herbivory-induced mulberry (Morus alba) leaf volatiles.  


Volatile organic compounds (VOCs) were collected from damaged and intact mulberry leaves (Morus alba L., Moraceae) and from Hyphantria cunea larvae by headspace absorption with Super Q columns. We identified their constituents using gas chromatography-mass spectrometry, and evaluated the responses of male H. cunea antennae to the compounds using gas chromatography-flame ionization detection coupled with electroantennographic detection. Eleven VOC constituents were found to stimulate antennae of male H. cunea moths: ?-ocimene, hexanal, cis-3-hexenal, limonene, trans-2-hexenal, cyclohexanone, cis-2-penten-1-ol, 6-methyl-5-hepten-2-one, 4-hydroxy-4-methyl-2-pentanone, trans-3-hexen-1-ol, and 2,4-dimethyl-3-pentanol. Nine of these chemicals were released by intact, mechanically-damaged, and herbivore-damaged leaves, while cis-2-penten-1-ol was released only by intact and mechanically-damaged leaves and ?-ocimene was released only by herbivore-damaged leaves. Results from wind tunnel experiments conducted with volatile components indicated that male moths were significantly more attracted to herbivory-induced volatiles than the solvent control. Furthermore, male moths' attraction to a sex pheromone lure was increased by herbivory-induced compounds and ?-ocimene, but reduced by cis-2-penten-1-ol. A proof long-range field trapping experiment showed that the efficiency of sex pheromone lures in trapping male moths was increased by ?-ocimene and reduced by cis-2-penten-1-ol. PMID:23166622

Tang, Rui; Zhang, Jin Ping; Zhang, Zhong Ning



Aroma enhancement and enzymolysis regulation of grape wine using ?-glycosidase  

PubMed Central

Adding ?-glycosidase into grape wine for enhancing aroma was investigated using gas chromatography-mass spectrometry (GC-MS) and Kramer sensory evaluation. Compared with the extract from control wines, the extract from enzyme-treated wines increased more aromatic compounds using steam distillation extraction (SDE) and GC-MS analyses. Theses aromatic compounds were as follows: 3-methyl-1-butanol formate, 3-pentanol, furfural, 3-methyl-butanoic acid, 2-methyl-butanoic acid, 3-hydroxy-butanoic acid ethyl ester, hexanoic acid, hexanoic acid ethyl ester, benzyl alcohol, octanoic acid, octanoic acid ethyl ester, dodecanoic acid, and ethyl ester. The enzymolysis regulation conditions, including enzymolysis temperature, enzymolysis time, and enzyme amount, were optimized through L9(34) orthogonal test. Kramer sensory evaluation was performed by an 11-man panel of judges. The optimum enzymolysis regulation conditions were found to be temperature of 45°C, enzymolysis time of 90 min, and enzyme amount of 58.32 U/mL grape wine, respectively. The Kramer sensory evaluation supported that the enzyme-treated wines produced a stronger fragrance. PMID:24804072

Zhu, Feng-Mei; Du, Bin; Li, Jun



Two Volatile Organic Compounds Trigger Plant Self-Defense against a Bacterial Pathogen and a Sucking Insect in Cucumber under Open Field Conditions  

PubMed Central

Systemic acquired resistance (SAR) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC)-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields. PMID:23698768

Song, Geun Cheol; Ryu, Choong-Min



Importance of the Debye interaction in organic solutions: Henry's law constants for polar liquids in nonpolar solvents and vice versa  

SciTech Connect

Henry's law constants have been determined for ..gamma..-butyrolactone (BL), ethyl acetate (EA), and 2-methyl-3-pentanol (MEP) in mixtures of iso-octane (ISO) and toluene (TOL), for BL, EA, TOL, and ISO in cinnamaldehyde (CIN) and for TOL and ISO in each other and in BL. From these data and published vapor pressures, the activity coefficients at infinite dilution and the standard molar Gibbs free energy of transfer, 2/..pi.. of the solutes from dilute solution in ISO to dilute solution in each solvent medium have been calculated. The different behavior patterns of BL and EA are attributed to differences in their abilities to exist in different conformations possessing different dipole moments. For polar solutes, 2//sup 0/ decreases with increasing polarizability of the solvent and with increasing dipole moment of the solute, suggesting increased contributions from dipole-induced dipole (Debye) interactions. The sigmoidal plot of 2//sup 0/ against the change in pair potential energy calculated from the classical expressions suggests that 2//sup 0/ seriously underestimates the strength of the Debye interactions in comparison with the London interactions.

Rytting, J.H.; McHan, D.R.; Higuchi, T.; Grant, D.J.W.



A Long-Chain Secondary Alcohol Dehydrogenase from Rhodococcus erythropolis ATCC 4277  

PubMed Central

A NAD-dependent secondary alcohol dehydrogenase has been purified from the alkane-degrading bacterium, Rhodococcus erythropolis ATCC 4277. The enzyme was found to be active against a broad range of substrates, particularly long-chain secondary aliphatic alcohols. Although optimal activity was observed with linear 2-alcohols containing between 6 and 11 carbon atoms, secondary alcohols as long as 2-tetradecanol were oxidized at 25% of the rate seen with mid-range alcohols. The purified enzyme was specific for the S-(+) stereoisomer of 2-octanol and had a specific activity for 2-octanol of over 200 (mu)mol/min/mg of protein at pH 9 and 37(deg)C, 25-fold higher than that of any previously reported S-(+) secondary alcohol dehydrogenase. Linear primary alcohols containing between 3 and 13 carbon atoms were utilized 20- to 40-fold less efficiently than the corresponding secondary alcohols. The apparent K(infm) value for NAD(sup+) with 2-octanol as the substrate was 260 (mu)M, whereas the apparent K(infm) values for the 2-alcohols ranged from over 5 mM for 2-pentanol to less than 2 (mu)M for 2-tetradecanol. The enzyme showed moderate thermostability (half-life of 4 h at 60(deg)C) and could potentially be useful for the synthesis of optically pure stereoisomers of secondary alcohols. PMID:16535152

Ludwig, B.; Akundi, A.; Kendall, K.



Volatile Compounds Originating from Mixed Microbial Cultures on Building Materials under Various Humidity Conditions  

PubMed Central

We examined growth of mixed microbial cultures (13 fungal species and one actinomycete species) and production of volatile compounds (VOCs) in typical building materials in outside walls, separating walls, and bathroom floors at various relative humidities (RHs) of air. Air samples from incubation chambers were adsorbed on Tenax TA and dinitrophenylhydrazine cartridges and were analyzed by thermal desorption-gas chromatography and high-performance liquid chromatography, respectively. Metabolic activity was measured by determining CO2 production, and microbial concentrations were determined by a dilution plate method. At 80 to 82% RH, CO2 production did not indicate that microbial activity occurred, and only 10% of the spores germinated, while slight increases in the concentrations of some VOCs were detected. All of the parameters showed that microbial activity occurred at 90 to 99% RH. The microbiological analyses revealed weak microbial growth even under drying conditions (32 to 33% RH). The main VOCs produced on the building materials studied were 3-methyl-1-butanol, 1-pentanol, 1-hexanol, and 1-octen-3-ol. In some cases fungal growth decreased aldehyde emissions. We found that various VOCs accompany microbial activity but that no single VOC is a reliable indicator of biocontamination in building materials. PMID:9687450

Korpi, Anne; Pasanen, Anna-Liisa; Pasanen, Pertti



Shape-tunable hollow silica nanomaterials based on a soft-templating method and their application as a drug carrier.  


A one-step soft-templating method for synthesizing shape-tunable hollow silica nanomaterials was developed in a reliable and highly reproducible way. For the first time, both nonspherical and spherical shapes with hollow interiors, including nanowire, nanospheres, and nanotadpole, were successfully obtained by simply changing the solvent. Poly(vinylpyrrolidone) (PVP)-water droplets were used as soft templates for the formation of hollow structures, while three different solvents, including 1-propanol, 1-pentanol, and ethanol, led to the designed shapes. It was found that the solvent, the formation of PVP-water droplets, the amount of ammonia, and the reaction time had great effects on the morphology of synthesized hollow nanomaterials. The effect of various factors on the morphology was systematically studied to propose a growth mechanism. The obtained hollow silica nanomaterials showed excellent reproducibility and great potential for a large-scale synthesis. Finally, the application of the developed hollow silica nanomaterials was demonstrated using the hollow spherical silica nanoparticles. Its drug-carrying ability was studied. The results could be extended for doping various target molecules into the hollow structures for a broad range of applications. PMID:25470033

Chen, Jiao; Wu, Xu; Hou, Xiaodong; Su, Xingguang; Chu, Qianli; Fahruddin, Nenny; Zhao, Julia Xiaojun



Dielectric barrier discharge carbon atomic emission spectrometer: universal GC detector for volatile carbon-containing compounds.  


It was found that carbon atomic emission can be excited in low temperature dielectric barrier discharge (DBD), and an atmospheric pressure, low power consumption, and compact microplasma carbon atomic emission spectrometer (AES) was constructed and used as a universal and sensitive gas chromatographic (GC) detector for detection of volatile carbon-containing compounds. A concentric DBD device was housed in a heating box to increase the plasma operation temperature to 300 °C to intensify carbon atomic emission at 193.0 nm. Carbon-containing compounds directly injected or eluted from GC can be decomposed, atomized, and excited in this heated DBD for carbon atomic emission. The performance of this new optical detector was first evaluated by determination of a series of volatile carbon-containing compounds including formaldehyde, ethyl acetate, methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, and absolute limits of detection (LODs) were found at a range of 0.12-0.28 ng under the optimized conditions. Preliminary experimental results showed that it provided slightly higher LODs than those obtained by GC with a flame ionization detector (FID). Furthermore, it is a new universal GC detector for volatile carbon-containing compounds that even includes those compounds which are difficult to detect by FID, such as HCHO, CO, and CO2. Meanwhile, hydrogen gas used in conventional techniques was eliminated; and molecular optical emission detection can also be performed with this GC detector for multichannel analysis to improve resolution of overlapped chromatographic peaks of complex mixtures. PMID:24328147

Han, Bingjun; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin



Temperature and viscosity dependence of the nonradiative decay rates of auramine-O and thioflavin-T in glass-forming solvents.  


Both auramine-O (AuO) and thioflavin-T (ThT) behave as fluorescent molecular rotors, meaning that their (non)radiative properties are markedly affected by the intramolecular rotation of the molecule. In this article, steady-state and time-resolved fluorescence of AuO and ThT were measured in three alcohols, 1-propanol, 1-butanol, and 1-pentanol, over a wide range of temperatures (86-260 K). These solvents are glass-forming liquids, and their viscosity and dielectric relaxation time increase by more than 10 orders of magnitude as the temperature is lowered from room temperature to ~100 K. Accordingly, the fluorescence nonradiative rates constants of AuO and ThT in these solvents decrease by about 3 orders of magnitude at the latter temperature range. We found very good correspondence between the temperature dependence of the nonradiative rate constant, k(nr), of both molecules and the dielectric relaxation rate of the solvents. The k(nr) values of AuO are twice those of ThT along the whole temperature range. The temperature dependence of k(nr) is consistent with the nonradiative model suggested by Glasbeek and co-workers. PMID:23176313

Erez, Yuval; Amdursky, Nadav; Gepshtein, Rinat; Huppert, Dan



Anticancer Properties of Novel Rhenium Pentylcarbanato Compounds against MDA-MB-468(HTB-132) Triple Node Negative Human Breast Cancer Cell Lines  

PubMed Central

Aim To study the efficacy of novel rhenium compounds to treat triple node negative breast cancer. Place and Duration Six (6) novel rhenium pentycarbanato compounds (PC1-6) were synthesized and triple node negative breast cancer cell lines HTB-132 and Balb/c mouse kidney cell lines were treated with each of them for 48 hours. The results were analyzed by a common trypan blue cell death assay system and statistically analyzed. Place and Duration The compounds were synthesized, analyzed and evaluated at the Department of Chemistryof Morgan State University, Baltimore, Maryland and the Pharmaceutical Sciences Department of Elizabeth City State University campus of the University of North Carolina system. Methodology The novel rhenium compounds were synthesized from one-pot reactions of Re2(CO)10 with the corresponding ?-diimine ligands in 1-pentanol.The compounds were characterized spectroscopically. The cell lines were cultured by standard cell culture procedure and treated with each of the six compounds in DMSO for 48 hours with a negative control and a DMSO vehicular control along with a cisplatin positive control.The cytotoxicity was evaluated by standard trypan blue assay and the results were statistically analyzed. Results The trypan blueassay reveals that these compounds have significant cytotoxicity against MDA-MB-468 (HTB-132) triple node negative breast cancer cell lines and are less nephrotoxic than cisplatin. Conclusion The novel rhenium compounds PC 1-6 can potentially find applications in the treatment of highly malignant triple node negative breast cancer. PMID:25419517

Parson, Carl; Smith, Valerie; Krauss, Christopher; Banerjee, Hirendra N.; Reilly, Christopher; Krause, Jeanette A.; Wachira, James M.; Giri, Dipak; Winstead, Angela; Mandal, Santosh K.



Selective detection of alkanolamine vapors by ion mobility spectrometry with ketone reagent gases.  


The ion mobility (IMS) spectra of the alkanolamines, monoethanolamine (MEA), 3-amino-1-propanol (PRA), 4-amino-1-butanol (BUA), and 5-amino-1-pentanol (PEA) with acetone and 4-heptanone reagent gases have been measured using a hand-held spectrometer. Monomer and dimer peak patterns were observed for all the alkanolamines with acetone reagent gas. Drift times of monomer and dimer ion clusters for each alkanolamine increased linearly in order of size of alkyl group. Ammonia, Freon 22, and F76 diesel vapors, having similar or coincident mobilities, caused severe interference. Replacement of acetone with 4-heptanone reagent gas resulted in good separation by the altering drift times of product ions. The limit of detection was 0.005 ppm having a linear range of 0.005-0.7 ppm, and signal saturation occurred above 0.88 ppm. Detection was reversible, with a response time of 4 min and a slower recovery time of > 60 min, at vapor levels of 0.7 ppm and ambient nozzle and drift-region temperatures. In contrast to acetone chemistry, single-peak patterns were observed for the alkanolamines with the 4-heptanone reagent. Further, drift times unexpectedly remained stagnant with increasing alkyl-group size. From atmospheric pressure chemical ionization (APcI) tandem mass spectral identifications and collision induced studies, dynamic changes in product-ion equilibria in the IMS drift region compensated by differences in collision cross sections were suggested as the governing causes of the unusual mobility effect. PMID:10701266

Gan, T H; Corino, G



Improvement of the Dimensional Stability of Powder Injection Molded Compacts by Adding Swelling Inhibitor into the Debinding Solvent  

NASA Astrophysics Data System (ADS)

Defects are frequently found in powder injection molded (PIM) compacts during solvent debinding due to the swelling of the binders. This problem can be alleviated by adjusting the composition of the debinding solvent. In this study, 10 vol pct swelling inhibitors were added into heptane, and the in-situ amounts of swelling and sagging of the specimen in the solvent were recorded using a noncontacting laser dilatometer. The results show that the addition of ethanol, 2-propanol, 1-butanol, and 1-pentanol reduced the amounts of swelling by 31, 21, 17, and 11 pct, respectively. This was because the small molecule alcohols, which do not dissolve paraffin wax (PW) or stearic acid (SA) in the binder system, could diffuse easily into the specimen and increased the portion of the swelling inhibitor inside. The amount of the extracted PW and SA also decreased, but only by 8.3, 6.1, 4.3, and 2.4 pct, respectively. The solubility parameters of 1-bromopropane (n-PB) and ethyl acetate (EA) are between those of heptane and alcohols, and they also yielded a slight reduction in the amounts of swelling by 6 and 11 pct, respectively. These results suggest that to reduce defects caused by binder swelling during solvent debinding, alcohols with high solubility parameters can be added into heptane without sacrificing significantly on the debinding rate.

Fan, Yang-Liang; Hwang, Kuen-Shyang; Su, Shao-Chin



Improved conversion efficiencies for n-fatty acid reduction to primary alcohols by the solventogenic acetogen "Clostridium ragsdalei".  


"Clostridium ragsdalei" is an acetogen that ferments synthesis gas (syngas, predominantly H2:CO2:CO) to ethanol, acetate, and cell mass. Previous research showed that C. ragsdalei could also convert propionic acid to 1-propanol and butyric acid to 1-butanol at conversion efficiencies of 72.3 and 21.0 percent, respectively. Our research showed that C. ragsdalei can also reduce pentanoic and hexanoic acid to the corresponding primary alcohols. This reduction occurred independently of growth in an optimized medium with headspace gas exchange (vented and gassed with CO) every 48 h. Under these conditions, conversion efficiencies increased to 97 and 100 % for propionic and butyric acid, respectively. The conversion efficiencies for pentanoic and hexanoic acid to 1-pentanol and 1-hexanol, respectively, were 82 and 62 %. C. ragsdalei also reduced acetone to 2-propanol at a conversion efficiency of 100 %. Further, we showed that C. ragsdalei uses an aldehyde oxidoreductase-like enzyme to reduce n-fatty acids to the aldehyde intermediates in a reaction that requires ferredoxin and exogenous CO. PMID:25410829

Isom, Catherine E; Nanny, Mark A; Tanner, Ralph S



Determination of paroxetine in blood and urine using micellar liquid chromatography with electrochemical detection.  


Paroxetine is a potent selective serotonin reuptake inhibitor used for the treatment of depression and related mood disorders. A micellar liquid chromatographic method was developed for the determination of paroxetine in serum and urine. Detection of paroxetine was carried out using a C18 column and a mobile phase of 0.15 M sodium dodecyl sulfate, 6% 1-pentanol at pH 3 (buffer salt 0.01 M NaH2PO4) running under isocratic mode at 1.0 mL/min and electrochemical detection at 0.8 V. The analyte was eluted without interferences in <15 min. The proposed methodology was validated under the guidelines of the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use in matrix in terms of specificity, linearity (r(2) > 0.9999; 0.5-5 ?g/mL range), accuracy (88-97.5%, recovery), repeatability (RSD < 0.54%), intermediate precision (RSD < 0.54%), limit of detection and quantification (0.001 and 0.005 ?g/mL, respectively) and robustness (RSD < 3.63%). Developed method was successfully applied to real blood and urine samples as well as in spiked serum and urine samples. The developed method was specific, rapid, precise, reliable, accurate, inexpensive and then suitable for routine analysis of paroxetine in monitorized samples. PMID:24448669

Agrawal, Nitasha; Marco-Peiró, Sergio; Esteve-Romero, Josep; Durgbanshi, Abhilasha; Bose, Devasish; Peris-Vicente, Juan; Carda-Broch, Samuel



A Boron-Complexation Strategy for Use with 1-Acyldipyrromethanes  

PubMed Central

1-Acyldipyrromethanes are important precursors in rational syntheses of diverse porphyrinic compounds. 1-Acyldipyrromethanes are difficult to purify, typically streaking upon chromatography and giving amorphous powders upon attempted crystallization. A solution to this problem has been achieved by reacting the 1-acyldipyrromethane with a dialkylboron triflate (e.g., Bu2B-OTf or 9-BBN-OTf) to give the corresponding B,B-dialkyl–B-(1-acyldipyrromethane)boron(III) complex. The reaction is selective for a 1-acyldipyrromethane in the presence of a dipyrromethane. The 1-acyldipyrromethane-boron complexes are stable to routine handling, are soluble in common organic solvents, crystallize readily, are hydrophobic, and chromatograph without streaking. The 1-acyldipyrromethane can be liberated in high yield from the boron complex upon treatment with 1-pentanol. Alternatively, the 1-acyldipyrromethane-boron complex can be used in the formation of a trans-A2B2-porphyrin. In summary, the boron-complexation strategy has broad scope and greatly facilitates the isolation of 1-acyldipyrromethanes. PMID:15287782

Muthukumaran, Kannan; Ptaszek, Marcin; Noll, Bruce; Scheidt, W. Robert; Lindsey, Jonathan S.



Experimental and computational study of the effect of alcohols on the solution and adsorption properties of a nonionic symmetric triblock copolymer.  


This study investigates the effect of alcohols on the solution and adsorption properties of symmetric triblock nonionic copolymers comprising blocks of ethylene oxide (EO) and propylene oxide (PO) (EO(37)PO(56)EO(37)). The cloud point, surface tension, critical micelle concentration (CMC), and maximum packing at the air-water interface are determined, and the latter is compared to the amount of polymer that adsorbs from solution onto polypropylene (PP) and cellulose surfaces. The interaction energy and radius of micelles are calculated by using molecular dynamics (MD) simulations. Equivalent MD bead parameters were used in dynamic density functional theory (DDFT) simulations to study the influence of alcohols on the phase behavior of EO(37)PO(56)EO(37) and its adsorption on PP from aqueous solutions. The simulation results agree qualitatively with the experimental observations. Ethanol acts as a good cosolvent for EO(37)PO(56)EO(37) and reduces the amount of EO(37)PO(56)EO(37) that adsorbs on PP surfaces; however, little or no influence is observed on the adsorption on cellulose. Interestingly, longer chain alcohols, such as 1-pentanol, produce the opposite effect. Overall, the solution and adsorption properties of nonionic symmetric triblock copolymers in the presence of alcohols are rationalized by changes in solvency and the hydrophobic effect. PMID:22188471

Liu, Xiaomeng; He, Feng; Salas, Carlos; Pasquinelli, Melissa A; Genzer, Jan; Rojas, Orlando J



Removal of acrylic coatings from works of art by means of nanofluids: understanding the mechanism at the nanoscale  

NASA Astrophysics Data System (ADS)

Conservation of works of art often involves the inappropriate application of synthetic polymers. We have proposed the use of alternative methodologies for conservation and formulated innovative cleaning nanostructured systems to remove previously applied polymer films and grime from painted surfaces. In particular, a novel ``micellar system'' composed of water, SDS, 1-pentanol, ethyl acetate and propylene carbonate was recently formulated and successfully used to remove acrylic and vinyl/acrylic copolymers from Mesoamerican wall paintings in the archeological site of Cholula, Mexico. This contribution reports on the mechanism of the interaction process that takes place between the nanostructured fluid and the polymer coating at the nanoscale. The structural properties of the ``micellar solution'' and of the polymer film are investigated before, during and after the interaction process using several surface and solution techniques. Rather than a classical detergency mechanism, we demonstrate that micelles act as solvent containers and interact with the polymer film leading to its swelling and detachment from the surface and to its segregation in a liquid droplet, which phase-separates from the aqueous bulk. After the removal process the micelles become smaller in size and undergo a structural re-arrangement due to the depletion of the organic solvents. These findings can be framed in an interaction mechanism which describes the removal process, opening up new perspectives in the design and formulation of new cleaning systems specifically tailored for intervention on particular conservation issues.

Baglioni, Michele; Rengstl, Doris; Berti, Debora; Bonini, Massimo; Giorgi, Rodorico; Baglioni, Piero



Primary and secondary metabolism of pentamidine by rats.  

PubMed Central

The antiprotozoal drug pentamidine [1,5-bis(4'-amidinophenoxy)pentane] has been previously shown to be metabolized by rat liver microsomes, and five of the seven putative primary metabolites have been identified. With the synthesis and identification of 5-(4'-amidinophenoxy)pentanoic acid and 5-(4'-amidinophenoxy)-1-pentanol as the remaining two metabolites, the primary metabolism of pentamidine in rats appears fully characterized. Use of [14C]pentamidine with rat liver microsomes confirms this conclusion, since no unidentified radioactive peaks were detected by high-performance liquid chromatography (HPLC). Isolated, perfused rat livers were used with [14C]pentamidine to identify secondary metabolites. Only two novel radioactive peaks were detected by HPLC analysis of perfused liver samples. The treatment of liver samples with sulfatase or beta-glucuronidase resulted in the reduction or elimination of these peaks and gave rise to peaks identified as para-hydroxybenzamidine and 5-(4'-amidinophenoxy)pentanoic acid. It was concluded from these results that only these two primary metabolites were conjugated with sulfate or glucuronic acid. After 4 h of incubation in the perfused liver system, approximately 15% of the recovered radiolabel was pentamidine. These results suggest that pentamidine metabolism can be rapid and extensive in rats. PMID:1416874

Berger, B J; Naiman, N A; Hall, J E; Peggins, J; Brewer, T G; Tidwell, R R



Effect of stirring on the safety of flammable liquid mixtures.  


Flash point is the most important variable employed to characterize fire and explosion hazard of liquids. The models developed for predicting the flash point of partially miscible mixtures in the literature to date are all based on the assumption of liquid-liquid equilibrium. In real-world environments, however, the liquid-liquid equilibrium assumption does not always hold, such as the collection or accumulation of waste solvents without stirring, where complete stirring for a period of time is usually used to ensure the liquid phases being in equilibrium. This study investigated the effect of stirring on the flash-point behavior of binary partially miscible mixtures. Two series of partially miscible binary mixtures were employed to elucidate the effect of stirring. The first series was aqueous-organic mixtures, including water+1-butanol, water+2-butanol, water+isobutanol, water+1-pentanol, and water+octane; the second series was the mixtures of two flammable solvents, which included methanol+decane, methanol+2,2,4-trimethylpentane, and methanol+octane. Results reveal that for binary aqueous-organic solutions the flash-point values of unstirred mixtures were located between those of the completely stirred mixtures and those of the flammable component. Therefore, risk assessment could be done based on the flammable component flash-point value. However, for the assurance of safety, it is suggested to completely stir those mixtures before handling to reduce the risk. PMID:20116168

Liaw, Horng-Jang; Gerbaud, Vincent; Chen, Chan-Cheng; Shu, Chi-Min



High efficiency solution processed fluorescent yellow organic light-emitting diode through fluorinated alcohol treatment at the emissive layer/cathode interface  

NASA Astrophysics Data System (ADS)

We compare solvent treatments using fluorinated alcohol (2,2,3,3,4,4,5,5-octafluoro- 1-pentanol) and ethanol in improving the efficiency of a polymer organic light-emitting diode (OLED) by spin coating the solvent on top of the emissive layer. The presence of fluorinated alcohol is confirmed using x-ray photoelectron spectroscopy. The electron current is found to be significantly enhanced following solvent treatment while the hole current remains the same. The solvent treatment by fluorinated alcohol on top of a ‘super-yellow’ poly-(p-phenylenevinylene) (SY-PPV) based OLED results in efficiency as high as 19.2 lm W-1 (20.9 cd A-1) at a brightness of 1000 cd m-2. The improvement of device efficiency through the use of fluorinated alcohol treatment can be attributed to its large dipole, which lowers the electron injection barrier. This work also suggests that fluorinated alcohol might be a better trap passivator for electrons than ethanol.

Ng, Calvin Yi Bin; Yeoh, Keat Hoe; Whitcher, Thomas J.; Azrina Talik, Noor; Woon, Kai Lin; Saisopa, Thanit; Nakajima, Hideki; Supruangnet, Ratchadaporn; Songsiriritthigul, Prayoon



Bacterial Degradation of tert-Amyl Alcohol Proceeds via Hemiterpene 2-Methyl-3-Buten-2-ol by Employing the Tertiary Alcohol Desaturase Function of the Rieske Nonheme Mononuclear Iron Oxygenase MdpJ  

PubMed Central

Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as this molecule possesses several potential hydroxylation sites. In Aquincola tertiaricarbonis L108 and Methylibium petroleiphilum PM1, a likely candidate catalyst for hydroxylations is the putative tertiary alcohol monooxygenase MdpJ. However, by comparing metabolite accumulations in wild-type strains of L108 and PM1 and in two mdpJ knockout mutants of strain L108, we could clearly show that MdpJ is not hydroxylating TAA to diols but functions as a desaturase, resulting in the formation of the hemiterpene 2-methyl-3-buten-2-ol. The latter is further processed via the hemiterpenes prenol, prenal, and 3-methylcrotonic acid. Likewise, 3-methyl-3-pentanol is degraded via 3-methyl-1-penten-3-ol. Wild-type strain L108 and mdpJ knockout mutants formed isoamylene and isoprene from TAA and 2-methyl-3-buten-2-ol, respectively. It is likely that this dehydratase activity is catalyzed by a not-yet-characterized enzyme postulated for the isomerization of 2-methyl-3-buten-2-ol and prenol. The vitamin requirements of strain L108 growing on TAA and the occurrence of 3-methylcrotonic acid as a metabolite indicate that TAA and hemiterpene degradation are linked with the catabolic route of the amino acid leucine, including an involvement of the biotin-dependent 3-methylcrotonyl coenzyme A (3-methylcrotonyl-CoA) carboxylase LiuBD. Evolutionary aspects of favored desaturase versus hydroxylation pathways for TAA conversion and the possible role of MdpJ in the degradation of higher tertiary alcohols are discussed. PMID:22194447

Schuster, Judith; Schäfer, Franziska; Hübler, Nora; Brandt, Anne; Rosell, Mònica; Härtig, Claus; Harms, Hauke; Müller, Roland H.



Can Volatile Organic Metabolites Be Used to Simultaneously Assess Microbial and Mite Contamination Level in Cereal Grains and Coffee Beans?  

PubMed Central

A novel approach based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–ToFMS) was developed for the simultaneous screening of microbial and mite contamination level in cereals and coffee beans. The proposed approach emerges as a powerful tool for the rapid assessment of the microbial contamination level (ca. 70 min versus ca. 72 to 120 h for bacteria and fungi, respectively, using conventional plate counts), and mite contamination (ca. 70 min versus ca. 24 h). A full-factorial design was performed for optimization of the SPME experimental parameters. The methodology was applied to three types of rice (rough, brown, and white rice), oat, wheat, and green and roasted coffee beans. Simultaneously, microbiological analysis of the samples (total aerobic microorganisms, moulds, and yeasts) was performed by conventional plate counts. A set of 54 volatile markers was selected among all the compounds detected by GC×GC–ToFMS. Principal Component Analysis (PCA) was applied in order to establish a relationship between potential volatile markers and the level of microbial contamination. Methylbenzene, 3-octanone, 2-nonanone, 2-methyl-3-pentanol, 1-octen-3-ol, and 2-hexanone were associated to samples with higher microbial contamination level, especially in rough rice. Moreover, oat exhibited a high GC peak area of 2-hydroxy-6-methylbenzaldehyde, a sexual and alarm pheromone for adult mites, which in the other matrices appeared as a trace component. The number of mites detected in oat grains was correlated to the GC peak area of the pheromone. The HS-SPME/GC×GC–ToFMS methodology can be regarded as the basis for the development of a rapid and versatile method that can be applied in industry to the simultaneous assessment the level of microbiological contamination and for detection of mites in cereals grains and coffee beans. PMID:23613710

Salvador, Ângelo C.; Baptista, Inês; Barros, António S.; Gomes, Newton C. M.; Cunha, Ângela; Almeida, Adelaide; Rocha, Silvia M.



Surface studies of dry and solid lubricants under different environmental conditions  

NASA Astrophysics Data System (ADS)

Advanced lubrication schemes depend on the presence of specific solids at or the continuous delivery of a gas to the sliding interface to manage friction and wear, and are known to have a strong environmental dependence. An in-vacuo pin-on-disc tribometer was designed to allow controlled environmental testing of the solid lubricants in order to determine the role of atmospheric components on their frictional behavior. Solid lubrication testing of highly oriented pyrolytic graphite, MoS2-Sb2O 3-Au, and MoS2-Sb2O3-C films was carried out under environments of 760 Torr air (50% relative humidity), 150 Torr oxygen, 8 Torr water, 610 Torr nitrogen, and 10-7 Torr vacuum. Dry lubrication testing of the native oxide of silicon (100) surfaces was carried out under environments of 760 Torr air (50% relative humidity), 1 Torr pentanol, and 10-7 Torr vacuum. Pin-on-disc tribometry revealed a strong dependence of friction and wear as a function of sliding environment. MoS2-Sb2O3-Au and MoS2-Sb 2O3-C films were strongly affected by the presence of water molecules. Friction and wear were observed to increase in the presence of partial pressures of water when compared to vacuum, oxygen, and nitrogen environmental testing. Spectroscopic analysis of the MoS2-Sb2O 3-Au and MoS2-Sb2O3-C films showed a general trend of MoS2 expression at the surface of low friction wear tracks. However, high friction could not be directly linked to the expression of a specific species within the wear track. X-ray photoelectron spectroscopy of the tracks created under ambient and water environments yielding high friction showed no clear relationship between the two conditions, even though their frictional behavior was similar. As revealed by atomic force microscopy measurements, the microstructure of the wear tracks of MoS2-Sb2O3-Au films produced under vacuum were predominantly low friction MoS2. The vacuum wear tracks of MoS2-Sb2O3-C films showed a mixed microstructure with both low friction MoS2, and moderate friction C. Ambient wear tracks for MoS2-Sb2O 3-Au films contained a minor, higher friction constituent, identified as Au, in the presence of the major constituent, MoS2. Ambient wear tracks for MoS2-Sb2O3-C films were more complex, expressing a majority of higher friction Sb2O3 and graphite constituents, with a reduced fraction of MoS2. These micro-tribometry measurements correlated well with those made by the pin-on-disc tribometer and X-ray photoelectron spectroscopy characterization. Dry or vapor-phase lubrication methods employing 1-pentanol were effective in reducing the friction of silicon (100) compared to sliding under ambient or vacuum environments. A continuous supply of 1-pentanol served to lubricate silicon surfaces through the formation of a tribochemical film which was composed primarily of (CH2)x species. However, the presence of a tribofilm was not responsible for the lowered friction coefficient, but it did enable the extreme wear protection previously reported for this lubrication technique.

Dudder, Gregory James


Analysis of thiabendazole, 4-tert-octylphenol and chlorpyrifos in waste and sewage water by direct injection - micellar liquid chromatography.  


A micellar liquid chromatographic method has been developed for the simultaneous quantification of the pesticides thiabendazole and chlorpyrifos, as well as an alkylphenol, which is included in pesticide formulations, i.e., 4-tert-octylphenol, in water. A sample was filtered and directly injected, avoiding large extraction steps using toxic solvents, thus expediting the experimental procedure. The contaminants were eluted without interferences in <17 min, using a mobile phase of 0.15 M sodium dodecyl sulfate - 6% 1-pentanol buffered at pH 3, running through a C18 column at 1 mL min(-1) under the isocratic mode. This optimal mobile phase was selected using a statistical approach, which considers the retention factor, efficiency and peak shape of the analytes measured in only a few mobile phases. The detection was carried out by measuring absorbance at 220 nm. The method was successfully validated in terms of specificity, calibration range (0.5-10 mg L(-1)), linearity (r(2) > 0.994), limit of detection and quantification (0.2-0.3; and 0.5-0.8 mg L(-1), respectively), intra- and interday accuracy (95.2-102.9%), precision (<8.3%), and ruggedness (<9.3%). The stability in storage conditions (at least 14 days) was studied. The method was safe, inexpensive, produced little pollutant and has a short analysis time, thus it is useful for the routine analysis of samples. Finally, the method was applied to analyse wastewater from the fruit-processing industry, wastewater treatment plants, and in sewage water belonging to the Castelló area (Spain). The results were similar to those obtained by an already reliable method. PMID:25604004

Romero-Cano, Ricard; Kassuha, Diego; Peris-Vicente, Juan; Roca-Genovés, Pasqual; Carda-Broch, Samuel; Esteve-Romero, Josep



Determination of volatile compounds in wine by gas chromatography-flame ionization detection: comparison between the U.S. Environmental Protection Agency 3sigma approach and Hubaux-Vos calculation of detection limits using ordinary and bivariate least squares.  


A capillary GC-flame ionization detection (FID) method to determine volatile compounds (ethyl acetate, 1,1-diethoxyethane, methyl alcohol, 1-propanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-butanol, and 2-butanol) in wine was investigated in terms of calculation of detection limits and calibration method. The main objectives were: (1) calculation of regression coefficient parameters by ordinary least-squares (OLS) and bivariate least-squares (BLS) regression models, taking into account errors in both axes; (2) estimation of linear dynamic range (LDR) according to International Conference on Harmonization recommendations; (3) performance evaluation of a method by using three different internal standards (ISs) such as acetonitrile, acetone, and 1-pentanol; (4) evaluation of LODs according to the U.S. Environmental Protection Agency (EPA) 3sigma approach and the Hubaux-Vos (H-V) method; (5) application of H-V theory to a gas chromatographic analytical method and to a food matrix; and (6) accuracy assessment of the method relative to methyl alcohol content through a Unione Italiana Vini (UIV) interlaboratory proficiency test. Calibration curves calculated via BLS and OLS show similar slopes, while intercepts are closer to zero in the first case, independent of the chosen IS. The studied ISs show a substantially equivalent behavior, even though the IS closer to the analyte retention time seems to be more appropriate in terms of LDR and LOD. Results indicate an underestimation of LODs using the EPA 3sigma approach instead of the more realistic H-V method, both with OLS and BLS regression models. Methanol contents compared with UIV average values indicate recovery between 90 and 110%. PMID:22649934

Caruso, Rosario; Scordino, Monica; Traulo, Pasqualino; Gagliano, Giacomo



Two-dimensional transport and wall effects in the thermal diffusion cloud chamber. II. Stability of operation  

NASA Astrophysics Data System (ADS)

In this paper, the second of a series of two presenting a detailed description of thermal diffusion cloud chamber operation, we address the operational stability of the vapor-gas mixture in a diffusion cloud chamber with respect to density profile extrema and the accompanying possibility of buoyancy-driven convective flow disturbances. We examine conditions for stable operation (no convective flow disturbances) in the central portion of the cloud chamber, as well as conditions necessary for stable operation in the vicinity of the cloud chamber wall. We find that the total density profile in the central portion of the cloud chamber can pass through a density minimum even though the density at the upper plate surface is less than the density at the lower plate surface. This local density profile inversion can result in unstable (convective) behavior that propagates through the cloud chamber. Furthermore, we find that local extrema in the total density profile near the chamber wall can lead to subtle, convective flows that are difficult to detect yet can exert a profound influence on nucleation in the central portion of the cloud chamber. We have developed a simple method to estimate the limiting total pressure in a cloud chamber that will support stable operation. From results of our investigations based upon this method, it appears that the thermal diffusion cloud chamber is best suited for experiments at higher temperatures where the accessible total pressure range is largest. Finally, we find that results of our investigation into the effects of total pressure and kind of background gas on nucleation in diffusion cloud chambers involving the low molecular weight alcohols and hydrogen and helium background gases cannot be explained on the basis of these kind of density disturbances occurring within the diffusion cloud chamber. Also, for (relatively) low vapor pressure materials, such as 1-pentanol or other high molecular weight alcohols and alkanes stability limitations may preclude nucleation measurements at low temperatures using a diffusion cloud chamber altogether.

Bertelsmann, Anne; Heist, Richard H.



Aliphatic ?-Nitroalcohols for Therapeutic Corneoscleral Cross-linking: Chemical Mechanisms and Higher Order Nitroalcohols  

PubMed Central

Purpose. The recent tissue cross-linking studies indicate that aliphatic ?-nitroalcohols (BNAs) may be useful as pharmacologic corneoscleral cross-linking agents. The present study was performed to identify the specific chemistry involved under physiologic conditions, with the intent of identifying more effective agents. Methods. The mechanism of chemical cross-linking at pH 7.4 and 37°C was studied using three techniques. The colorimetric Griess assay was used to follow the release of nitrite from three mono-nitroalcohols (2-nitroethanol [2ne], 2-nitro-1-propanol [2nprop]), and 3-nitro-2-pentanol [3n2pent]). Second, the evolution of 2nprop in 0.2 M NaH2PO4/Na2HPO4/D2O was studied using 1H-NMR. Third, thermal shrinkage temperature analysis (Ts), a measure of tissue cross-linking, was used to support information from 1the H-NMR studies. Results. A time-dependent release of nitrite was observed for all three mono-nitroalcohols studied. The maximum levels were comparable using either 2ne or 2nprop (?30%). However, much less (?10%) was observed from 3n2pent. Using 1H-NMR, 2nprop evolved into a unique splitting pattern. No match was observed with reference spectra from three possible products of denitration. In contrast, 2-methyl-2-nitro-1,3-propanediol (MNPD), a nitro-diol, was identified, implying the formation of formaldehyde from a retro-nitroaldol (i.e., reverse Henry) reaction. In support of this mechanism, Ts shifts induced by the nitro-triol 2-hydroxymethyl-2-nitro-1,3-propanediol (HNPD) were superior to the nitro-diol MNPD which were superior to the mono nitroalcohol 2nprop. Conclusions. BNAs function as both formaldehyde and nitrite donors under physiologic conditions to cross-link collagenous tissue. Higher order BNAs are more effective than mono nitroalcohols, raising the possibility of using these agents for therapeutic corneoscleral cross-linking. PMID:19797229

Solomon, Marissa R.; Wen, Quan; Turro, Nicholas J.; Trokel, Stephen L.



Initial Studies Using Aliphatic ?-Nitro Alcohols for Therapeutic Corneal Cross-Linking  

PubMed Central

Purpose Corneal collagen cross-linking through UVA-riboflavin photochemistry (UVAR) has been shown to be an effective treatment for keratoconus and related keratectasias. In recent studies using sclera, the authors observed that short-chain aliphatic ?-nitro alcohols can cross-link collagenous tissue under physiologic conditions. Thus, this study was undertaken to evaluate these agents as potential pharmacologic alternatives to UVAR. Methods Porcine corneal strips (8 × 4 mm) and corneoscleral complexes were cross-linked using 1 to 100 mM 2-nitroethanol (2ne), 2-nitro-1-propanol (2nprop), and 3-nitro-2-pentanol (3n2pent) at pH 7.4, 34°C. Cross-linking by UVAR was carried out for comparison. Thermal shrinkage temperature analysis was used to evaluate cross-linking effects, and changes in corneal light transmission were determined with a fiber-optic spectrophotometer. Results At 10 and 100 mM for 96 hours, initial shrinkage temperature (Ti) was shifted by 3.3°C (P < 0.001) and 9.8°C (P < 0.001) for 2ne, 2.9°C (P = 0.008) and 4.9°C (P < 0.001) for 2nprop, and 3.8°C (P = 0.003) and 4.9°C (P < 0.001) for 3n2pent. Reacting at 1 mM through daily exchange of fluid over 7 days shifted Ti by 3.8°C (P < 0.001), 4.4°C (P = 0.002), and 3.2°C (P = 0.005), for 2ne, 2nprop, and 3n2pent, respectively. These shifts were greater than cross-linking using UVAR (Ti = 1.9°C; P = 0.012). In the blue light region (400?500 nm), transmission was decreased by 5.6% (P = 0.003), 2.1% (P = 0.260), and 0% (P = 0.428) for 2ne, 2nprop, and 3n2pent, respectively. Conclusions ?-Nitro alcohols can induce corneal cross-linking in vitro better than the UVAR technique and can induce negligible effects on light transmission. These early results suggest that such compounds could be used as topical stiffening agents for keratoconus and related disorders. PMID:18836172

Paik, David C.; Wen, Quan; Braunstein, Richard E.; Airiani, Suzanna; Trokel, Stephen L.



Milk volatile organic compounds and fatty acid profile in cows fed timothy as hay, pasture, or silage.  


Nutrient composition and organoleptic properties of milk can be influenced by cow diets. The objective of this study was to evaluate the forage type effects on volatile organic compounds, fatty acid (FA) profile, and organoleptic properties of milk. Timothy grass was fed as hay, pasture, or silage during a period of 27 d to a group of 21 cows in a complete block design based on days in milk. Each cow also received 7.2 kg/d of a concentrate mix to meet their nutrient requirements. Forage dry matter intake averaged 13.9 kg/d and was not different among treatments. Milk yield was higher for cows fed pasture, intermediate for cows fed silage, and lowest for cows fed hay. However, milk fat content was higher for cows fed hay and silage, compared with cows fed pasture. As a result, fat-corrected milk and fat yield were not different among treatments. Increasing the supply of dietary cis-9,cis-12 18:2 (linoleic acid) and cis-9,cis-12,cis-15 18:3 (?-linolenic acid) when feeding pasture enhanced the concentration of these 2 essential FA in milk fat compared with feeding hay or silage. Moreover, the ratio of 16:0 (palmitic acid) to cis-9 18:1 (oleic acid), which is closely related to the melting properties of milk fat, was lower in milk from cows on pasture than in milk from cows fed hay or silage. Cows fed hay produced milk with higher levels of several free FA and ?-lactones, but less pentanal and 1-pentanol. More dimethyl sulfone and toluene were found in milk of cows on pasture. Cows fed silage produced milk with higher levels of acetone, 2-butanone, and ?-pinene. Results from a sensory evaluation showed that panelists could not detect a difference in flavor between milk from cows fed hay compared with silage. However, a significant number of assessors perceived a difference between milk from cows fed hay compared with milk from cows fed pasture. In a sensory ranking test, the percentage of assessors ranking for the intensity of total (raw milk, fresh milk, and farm milk), sweet (empyreumatic, vanilla, caramel, and sugar), and grassy (grass, leafy vegetable, and plant) flavors was higher for milk from cows fed pasture compared with hay and silage. Using timothy hay, pasture, or silage harvested at a similar stage of development, the current study shows that the taste of milk is affected by the forage type fed to cows. More research is, however, needed to establish a link between the sensory attributes of milk and the observed changes in volatile organic compounds and FA profile. PMID:24035021

Villeneuve, M-P; Lebeuf, Y; Gervais, R; Tremblay, G F; Vuillemard, J C; Fortin, J; Chouinard, P Y



Synthesis of p-iron(III) oxide, n-iron(III) oxide, and carbon-modified-n-titanium dioxide and their application in self-driven photoelectrochemical cells: p-iron(III) oxide/n-iron(III) oxide, p-iron(III) oxide/carbon-modified-n-titanium dioxide, and p-gallium indium phosphide/carbon-modified-n-titanium dioxide for direct water photoelectrolysis  

NASA Astrophysics Data System (ADS)

My Ph.D. Dissertation describes (1) the influence of metal dopants on the spray pyrolytic synthesis of p-type and n-type iron(III) oxide thin film semiconductors, (2) the fabrication of carbon-modified (CM) n-type titanium dioxide, and (3) various self-driven photoelectrochemical cells (PEC) for water splitting. (1) Stable thin films of iron(III) oxide was the first goal pursued in this work. Various metal dopants were investigated to ascertain their viability as good dopant for iron(III) oxide. These metals included copper, zinc, and magnesium. This was followed by investigating metals that could improve the conductivity of n-type iron(III) oxide, which included indium, iodine, manganese, and calcium. Research showed that zinc improved p-type characteristics the best, and considerably improved stability of p-type iron(III) oxide in acidic media. Indium-doped n-type iron(III) oxide showed improvement in photocurrent response over naturally-doped iron(III) oxide; however, there was a loss in the onset potential, which proved vital for developing a self-driven PEC. Importantly, the use of 1-pentanol as the spray solution solvent instead of ethanol improved the onset potential and photoresponse of n-type iron(III) oxide which helped to fabricate a self-driven p-type/n-type iron(III) oxide PEC for water splitting. (2) Carbon-modified n-type titanium dioxide electrodes were found to be extremely valuable towards fabrication of self-driven water splitting PEC, because the addition of carbon into the titanium dioxide crystal structure provided it with the ability to absorb light much further into the visible spectrum. Unmodified titanium dioxide can only absorb ˜13% of the total solar power (100 mW/cubic cm) of Air Mass (AM) 1.5; in other words wavelengths of light from ultraviolet to 414 nm. Carbon modification of n-type titanium dioxide allows it to absorb up to 535 nm, or ˜30% of the total solar power. (3) The most important part of this work is the fabrication of a self-driven PEC for water splitting using zinc-doped p-type iron(III) oxide and naturally-doped n-type iron(III) oxide; carbon-modified n-type titanium dioxide and zinc-doped p-type iron(III) oxide; and p-type gallium indium phosphide and carbon-modified n-type titanium dioxide.

Ingler, William B., Jr.


Experimental study of the effect of test-well arrangement for partitioning interwell tracer test on the estimation of NAPL saturation  

NASA Astrophysics Data System (ADS)

Partitioning interwell tracer test (PITT) is a method to quantify and qualify a contaminated site with NAPLs through a degree of retardation of partitioning tracers compared to a conservative one. Although PITT is known to be a more effective method to measure the saturation of spatially-distributed NAPL contaminant than the point investigation method, the saturation estimation from PITT is reported to be underestimated due to various factors including heterogeneity of the media, adsorption, source zone NAPL architecture, and long tailing in breakthrough curves of partitioning tracers. Analytical description of PITT assumes that the injection-pumping well pair is on the line of ambient groundwater flow direction, but the test-well pair could easily be off the line in the field site, which could be another erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair to ambient groundwater flow direction based on the result from PITT. The experiments were conducted in a small-scale 3D sandbox with dimensions of 0.5 m × 0.4 m × 0.15 m (LWH) of stainless steel. The surface is covered and sealed with a plexiglass plate to make the physical model a confined aquifer. Eight full-screened wells of Teflon material were installed along the perimeter of a 50 mm circle with 45 degree intervals in the middle of the physical model. Both ends of the sand box are connected to constant head reservoirs. The physical model was wet-packed with sieved and washed sand. Trichloroethylene (TCE) and bromide were used as the contaminant and the conservative tracer, respectively. Hexanol, 2,4-dimethyl-3-pentanol and 6-methyl-2-heptanol were used as partitioning tracers. Before the injection of TCE, a PITT was conducted to measure adsorption coefficient of partitioning tracers to the sand material. TCE of 4.5 mL, dyed with Sudan IV, was injected into the inner part of the circle of the wells. PITTs using the test-well pair parallel and with angles of 45 and 90 degrees to ambient flow direction were performed. Another PITT was conducted at an increased pumping rate with the test-well pair at a 45 degree angle to examine the effect of pumping rate. From the experiments, it was found that as the angles of the test-well pair to ambient groundwater flow direction increased, the estimated NAPL saturation decreased. Although the increase in pumping rate in this experiment reduces the effect of the obliqueness of the test-well arrangement, the effect of rate-limited transfer of partitioning tracers due to the increased pumping rate on the PITT should be examined in the interpretation. The results of these experiments revealed that the arrangement of the test-well pair is another controlling factor in performing and interpreting PITT in the field, in addition to the factors such as heterogeneity, source zone architecture, and tailing. Key words: PITT, test-well arrangement, ambient groundwater flow direction, NAPL saturation Acknowledgements: This research was supported by the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Knowledge Economy of Korea. 11-3414

Kim, B.; Kim, Y.; Yeo, I.; Yongcheol Kim, In Wook Yeo



Decontamination of Tritiated-Water Using Super-hydrophobic Pt-Catalyst Synthesized with Water-in-Supercritical CO{sub 2}  

SciTech Connect

Tritium, {sup 3}H, is one of the hydrogen isotopes, created in coolant of a fission reactor and to be utilized as fuel for nuclear fusion reactors. Since a large amount of tritium will be contained in a fusion reactor or in a fission reactor, a small fraction of the tritiated chemical species, in most cases, tritiated water, may leak to the environment. Tritium is, however, a radioactive isotope whose specific radioactivity is 4 x 10{sup 17} Bq kg{sup -1}, and easy to transfer in human body, its confinement is very important from the safety aspect. One of the problems of tritium confinement and decontamination of tritiated chemical species is related with necessity of its isotope separation from lighter hydrogen isotopes, {sup 2}H and {sup 1}H. Most of principles for the isotope separations are based on fractionations of isotopes in different chemical species. A large fractionation for hydrogen isotopes is observed in a chemical exchange of hydrogen atoms between water, Q{sub 2}O, and hydrogen gas, Q{sub 2}, where 'Q' denotes one of the hydrogen isotopes. Heavier isotopes are enriched significantly into Q{sub 2}O rather than Q{sub 2}. Therefore practical method of tritium removal would be established by hydrogen isotope separation with chemical exchange of water and hydrogen gas. At first, we prepared a catalyst, by reducing Pt{sup 4+} in reversed micelles where the reducing agent, aqueous solution of sodium tetra borohydrate, NaBH{sub 4} was also contained in reversed micelles prepared separately. In this situation, micelles containing Pt{sup 4+} and reducing reagent collided and produced Pt nanoparticles, which were expected to be impregnated in the hydrophobic structure after depressurization. After this type of earlier experiment we determined a mass of impregnated Pt by total dissolution of gauze with aqua regia followed by concentration measurement of Pt with ICP-AES. We performed several trials, unfortunately, however, the mass of Pt deposited on the gauze was very small to detect, and this approach turns to be not successful. As the second approach, we utilize CO{sub 2} soluble Pt precursor, CODMe{sub 2}Pt purchased from Sigma-Aldrich Co. and H{sub 2} gas as reducing agent, which could be completely mixed with SC-CO{sub 2}. This system was well-known for Pt particle formation by auto-catalytic growth. The second approach was aiming at increasing Pt amount deposited in the gauze. This approach was successful in increasing Pt amount, but the Pt particle size also increased to be more than 50 nm, which was not suitable for catalyst. Finally, we synthesized the catalyst by the following procedure: firstly, a reducing agent of NaBH{sub 4} was deposited on the nano-textured hydrophobic layer on the gauze. This step was realized by forming reversed micelles of aqueous NaBH{sub 4} solution using a surfactant AOT and a co-surfactant 2,2,3,3,4,4,5,5,-octafluoro-1-pentanol (F-pentanol) in SC-CO{sub 2}. This system of surfactant combination of AOT and F-pentanol has been found to work successfully in recent studies. In the second step, the gauze was contacted with CODMe{sub 2}Pt dissolved in SC-CO{sub 2} to synthesize seeds of Pt particles for the auto-catalytic reaction proceeding by CODMe{sub 2}Pt with hydrogen. The seeds were formed by the reaction between deposited NaBH{sub 4} and CODMe{sub 2}Pt in SC-CO{sub 2}. The physical characterization of this catalyst was performed by SEM-EDS. By this procedure, the Pt hydrophobic catalyst where Pt nanoparticle of 10 nm in diameter was locally deposited in the nano-textured layer was successfully prepared. Hydrophobicity after the chemical Pt deposition was tested by measurement of water absorbed on the gauze and the catalyst performance was evaluated by {sup 1}H{sup 2}H formation through the scrambling reaction from {sup 1}H{sub 2} and {sup 2}H{sub 2} and the reaction was successfully observed. We demonstrated a new hydrophobic catalyst preparation using SC-CO{sub 2} effectively. We can conclude that the approach of creating Pt nanoparticles in SC-CO{sub 2} and depositing them in

Youichi Enokida; Kayo Sawada [EcoTopia Science Institute (Japan)]|[Graduate School of Engineering, Nagoya University, 1 furo-cho, Nagoya 463-8603, Aichi-ken (Japan); Ryosuke Shimizu [EcoTopia Science Institute (Japan); Ichiro Yamamoto [Graduate School of Engineering, Nagoya University, 1 furo-cho, Nagoya 463-8603, Aichi-ken (Japan)