Catalytic degradation of the nerve agent VX by water-swelled polystyrene-supported ammonium fluorides.

PubMed

Marciano, Daniele; Goldvaser, Michael; Columbus, Ishay; Zafrani, Yossi

2011-10-21

The catalytic degradation of the nerve agent VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate) by water-swelled polymer-supported ammonium fluorides is described. VX (0.06-0.53 mol/mol F(-)) is rapidly degraded (t(1/2) ∼ 10-30 min) to form the "G-analogue" (O-ethyl methylphosphonofluoridate), which hydrolyzes (t(1/2) ∼ 1-1.5 h) to the nontoxic EMPA (ethyl methylphosphonic acid). The toxic desethyl-VX is not formed. The catalytic effect of fluoride is maintained even when 6 equiv of VX are loaded. GB (O-isopropyl methylphosphonofluoridate) and desethyl-VX agents are also degraded under these conditions.

Investigations into the chemistry, toxicology, metabolism and possible mode of action of O-ethyl S-methyl ethylphosphonothioate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hur, J.H.

1989-01-01

The chemical and metabolic oxidation of O-ethyl S-methyl ethylphosphonthioate (1) as a model compound was studied. This compound has the following toxicological properties: LD{sub 50} (rat) 4.6 mg/kg, LD{sub 50}(HF) 14.0 ug/g; k{sub i}(BAChE) {equals} 303, k{sub i}(HFAChE) {equals} 623. {sup 13} C- and {sup 31}P-NMR were mainly used in this study. The chemical oxidation of 1 with m-CPBA in CDCl{sub 3} resulted in the formation of O-ethyl ethylphosphonic acid (2), O-ethyl ethylphosphinyloxymethylsulfonate (3) and O-ethyl ethylphosphonic acid anhydride (4). However, oxidation reaction of the model compound 1 with MPPA in D{sub 2}O gave 2 and methylsulfonic acid. 1 wasmore » incubated in vitro with rat liver microsomal oxidase, and 2 and methylsulfenic acid were observed along with 1. For the in vivo study, a number of houseflies were treated with 14ug/g (LD{sub 50} level) of 1. Analysis of the extracts of metabolic products provided evidence of the formation of 2. The existence of 1 S-oxide was demonstrated by use of a trapping method and the observation of oxidation products. The S-oxide has been proposed as a possible active intermediate responsible for the high toxicity of 1 to animals. However, owing to its instability it is unlikely that the S-oxide intermediate would persist in an aqueous biological environment long enough to attack the target enzyme. 4 was shown to have high toxicity to the rat and housefly and was also a potent anticholinesterase against BAChE and HFAChE . The presence of 4 was observed directly by the monitoring experiments during the chemical oxidation in aqueous conditions. This provided evidence that this metabolite is stable enough to attack the target site in biological systems. The anhydride 4 is proposed as the active metabolite in in vivo systems, responsible for high toxicity of 1.« less

Reactions of VX, HD, and their simulants with NaY and AgY zeolites. Desulfurization of VX on AgY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, G.W.; Bartram, P.W.

1999-11-09

The room-temperature reactions of the chemical warfare agents VX (O-ethyl S-2-(diisopropylamino)-ethyl methylphosphonothioate), HD (2,2{prime}-dichloroethyl sulfide, or mustard), and their common simulants, O,S-diethyl phenylphosphonothioate (DEPPT) and 2-chloroethyl phenyl sulfide (CEPS), with NaY and silver-exchanged (AgY) zeolites have been studied using solid-state magic angle spinning NMR. VX hydrolyzes via exclusive cleavage of the P{single{underscore}bond}S bond on both NaY and AgY to yield ethyl methylphosphonate (EMPA). The reaction is significantly faster on AgY than on NaY, suggesting catalysis by silver. On AgY, an intermediate silver salt of EMPA is apparently formed which is slowly converted to ethyl 2-(diisopropylamino)ethyl methylphosphonate (QB, the desulfurized analoguemore » of VX) in about a 78% yield. DEPPT similarly hydrolyzes via P{single{underscore}bond}S cleavage on AgY to yield an apparent silver salt of ethyl phenylphosphonate, which does not undergo further reaction to the desulfurized analogue. No reaction is observed for DEPPT on NaY. HD on AgY forms both vinyl sulfide and the cyclic ether 1,4-thioxane. HD reacts faster on NaY to exclusively form the CH-TG sulfonium ion (HOCH{sub 2}CH{sub 2}SCH{sub 2}CH{sub 2}S{sup +}[CH{sub 2}CH{sub 2}OH]{sub 2}). CEPS also reacts faster on NaY, forming 2-hydroxyethyl phenyl sulfide. On AgY, CEPS does not give the vinyl product, but does yield the ether product PhSCH{sub 2}CH{sub 2}OCH{sub 2}CH{sub 2}SPh. A mechanism is proposed for the silver-catalyzed hydrolysis of VX, the desulfurization of the cleaved thiol, and the formation of QB.« less

Conformational and spectroscopic study of xanthogen ethyl formates, ROC(S)SC(O)OCH₂CH₃. Isolation of CH₃CH₂OC(O)SH.

PubMed

Juncal, Luciana C; Cozzarín, Melina V; Romano, Rosana M

2015-03-15

ROC(S)SC(O)OCH2CH3, with R=CH3-, (CH3)2CH- and CH3(CH2)2-, were obtained through the reaction between potassium xanthate salts, ROC(S)SK, and ethyl chloroformate, ClC(O)OCH2CH3. The liquid compounds were identified and characterized by (1)H and (13)C NMR and mass spectrometry. The conformations adopted by the molecules were studied by DFT methods. 6 conformers were theoretically predicted for R=CH3- and (CH3)2CH-, while the conformational flexibility of the n-propyl substituent increases the total number of feasible rotamers to 21. For the three molecules, the conformers can be associated in 3 groups, being the most stable the AS forms - the C=S double bond anti (A) with respect to the C-S single bond and the S-C single bond syn (S) with respect to the C=O double bond - followed by AA and SS conformers. The vibrational spectra were interpreted in terms of the predicted conformational equilibrium, presenting the ν(C=O) spectral region signals corresponding to the three groups of conformers. A moderated pre-resonance Raman enhancement of the ν(C=S) vibrational mode of CH3(CH2)2OC(S)SC(O)OCH2CH3 was detected, when the excitation radiation approaches the energy of a n→π∗ electronic transition associated with the C=S chromophore. UV-visible spectra in different solvents were measured and interpreted in terms of TD-DFT calculations. The unknown molecule CH3CH2OC(O)SH was isolated by the UV-visible photolysis of CH3OC(S)SC(O)OCH2CH3 isolated in Ar matrix, and also obtained as a side-product of the reaction between potassium xanthate salts, ROC(S)SK, and ethyl chloroformate, ClC(O)OCH2CH3. Copyright © 2014 Elsevier B.V. All rights reserved.

[(S)-1-Carbamoylethyl]bis(dimethylglyoximato-kappa2N,N')[(S)-1-phenylethylamine]cobalt(III) and bis(dimethylglyoximato-kappa2N,N')[(R)-1-(N-methylcarbamoyl)ethyl][(R)-1-phenylethylamine]cobalt(III) monohydrate.

PubMed

Orisaku, Keiko Komori; Hagiwara, Mieko; Ohgo, Yoshiki; Arai, Yoshifusa; Ohgo, Yoshiaki

2005-04-01

The title complexes, [Co(C3H6NO)(C4H7N2O2)2(C8H11N)] and [Co(C4H8NO)(C4H7N2O2)2(C8H11N)].H2O, were resolved from [(RS)-1-carbamoylethyl]bis(dimethylglyoximato)[(S)-1-phenylethylamine]cobalt(III) and bis(dimethylglyoximato)[(RS)-1-(N-methylcarbamoyl)ethyl][(R)-1-phenylethylamine]cobalt(III), respectively, and their crystal structures were determined in order to reveal the absolute configuration of the major enantiomer produced in the photoisomerization of each series of 2-carbamoylethyl and 2-(N-methylcarbamoyl)ethyl cobaloxime complexes.

Nanodispersive mixed oxides for destruction of warfare agents prepared by homogeneous hydrolysis with urea

NASA Astrophysics Data System (ADS)

Daněk, Ondřej; Štengl, Václav; Bakardjieva, Snejana; Murafa, Nataliya; Kalendová, Andrea; Opluštil, Frantisek

2007-05-01

Nanocrystalline mixed oxides of Ti, Zn, Al and Fe were prepared by a homogeneous hydrolysis of sulphates with urea at temperature of 100 °C in an aqueous solution. The prepared samples were characterized by BET and BJH measurements, an X-ray powder diffraction and scanning electron microscopy. These oxides were taken for an experimental evaluation of their reactivity with yperite (2,2‧-dichloroethyl sulphide), soman (3,3-dimethyl-2-butyl methylphosphonofluoridate) and matter VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothionate). An excellent activity in decomposition of chemical warfare agents was observed in these materials (conversion degree higher then 96%/h).

Analysis of chemical warfare agents in organic liquid samples with magnetic dispersive solid phase extraction and gas chromatography mass spectrometry for verification of the chemical weapons convention.

PubMed

Singh, Varoon; Purohit, Ajay Kumar; Chinthakindi, Sridhar; Goud, Raghavender D; Tak, Vijay; Pardasani, Deepak; Shrivastava, Anchal Roy; Dubey, Devendra Kumar

2016-05-27

A simple, sensitive and low temperature sample preparation method is developed for detection and identification of Chemical Warfare Agents (CWAs) and scheduled esters in organic liquid using magnetic dispersive solid phase extraction (MDSPE) followed by gas chromatography-mass spectrometry analysis. The method utilizes Iron oxide@Poly(methacrylic acid-co-ethylene glycol dimethacrylate) resin (Fe2O3@Poly(MAA-co-EGDMA)) as sorbent. Variants of these sorbents were prepared by precipitation polymerization of methacrylic acid-co-ethylene glycol dimethacrylate (MAA-co-EGDMA) onto Fe2O3 nanoparticles. Fe2O3@poly(MAA-co-EGDMA) with 20% MAA showed highest recovery of analytes. Extractions were performed with magnetic microspheres by MDSPE. Parameters affecting the extraction efficiency were studied and optimized. Under the optimized conditions, method showed linearity in the range of 0.1-3.0μgmL(-1) (r(2)=0.9966-0.9987). The repeatability and reproducibility (relative standard deviations (RSDs) %) were in the range of 4.5-7.6% and 3.4-6.2% respectively for organophosphorous esters in dodecane. Limits of detection (S/N=3/1) and limit of quantification (S/N=10/1) were found to be in the range of 0.05-0.1μgmL(-1) and 0.1-0.12μgmL(-1) respectively in SIM mode for selected analytes. The method was successfully validated and applied to the extraction and identification of targeted analytes from three different organic liquids i.e. n-hexane, dodecane and silicon oil. Recoveries ranged from 58.7 to 97.3% and 53.8 to 95.5% at 3μgmL(-1) and 1μgmL(-1) spiking concentrations. Detection of diethyl methylphosphonate (DEMP) and O-Ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX) in samples provided by the Organization for Prohibition of Chemical Weapons Proficiency Test (OPCW-PT) proved the utility of the developed method for the off-site analysis of CWC relevant chemicals. Copyright © 2016 Elsevier B.V. All rights reserved.

High Throughput Determination of VX in Drinking Water by ...

EPA Pesticide Factsheets

Methods Report This document provides the standard operating procedure for determination of the chemical warfare agent VX (O-Ethyl S-2-Diisopropylamino-Ethyl Methylphosphonothioate) in drinking water by isotope dilution liquid chromatography tandem mass spectrometer (LC/MS/MS). This method was adapted from one that was initially developed by the Centers for Disease Control and Prevention, in the National Center for Environmental Health for the determination and quantitation of VX in aqueous matrices. This method is designed to support site-specific cleanup goals of environmental remediation activities following a homeland security incident involving this analyte.

Highly sensitive sites for guanine-O6 ethylation in rat brain DNA exposed to N-ethyl-N-nitrosourea in vivo.

PubMed Central

Nehls, P; Rajewsky, M F; Spiess, E; Werner, D

1984-01-01

Brain chromosomal DNA isolated from fetal BDIX-rats 1 h after i.v. administration of the ethylating N-nitroso carcinogen N-ethyl-N-nitrosourea (75 micrograms/g body weight), statistically contained one molecule of O6-ethyl-2'-deoxyguanosine (O6-EtdGuo) per 81 micron of DNA, as determined in enzymatic DNA hydrolysates by competitive radio-immunoassay using a high-affinity anti-(O6-EtdGuo) monoclonal antibody (ER-6). After fragmentation of the DNA by the restriction enzyme AluI (average fragment length, Lav = 0.28 micron = 970 bp; length range, Lr = 1.87-0.02 micron = 6540 - 60 bp), a small (approximately 2%) fraction of DNA enriched in specific polypeptides tightly associated with DNA was separated from the bulk DNA by a glass fiber binding technique. As analyzed by immune electron microscopy, approximately 1% of the DNA molecules in this fraction contained clusters of 2-10 (O6-EtdGuo)-antibody binding sites (ABS). On the cluster-bearing fragments (Lav, 0.85 micron +/- 0.50 micron S.D.; corresponding to 2970 +/- 1760 bp) the average ABS-ABS interspace distance was 110 nm (= 390 bp; range approximately 9-600 nm), indicating a highly non-random distribution of O6-EtdGuo in target cell DNA. Images Fig. 2. PMID:6370677

Galantamine is a novel post-exposure therapeutic against lethal VX challenge.

PubMed

Hilmas, Corey J; Poole, Melissa J; Finneran, Kathryn; Clark, Matthew G; Williams, Patrick T

2009-10-15

The ability of galantamine hydrobromide (GAL HBr) treatment to antagonize O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX)-induced lethality, impairment of muscle tension, and electroencephalographic (EEG) changes was assessed in guinea pigs. Guinea pigs were challenged with 16.8 microg/kg VX (2LD50). One min after challenge, animals were administered 0.5 mg/kg atropine sulfate (ATR) and 25 mg/kg pyridine-2-aldoxime methochloride (2-PAM). In addition, guinea pigs were given 0, 1, 2, 4, 8 or 10 mg/kg GAL as a post-exposure treatment immediately prior to ATR and 2-PAM. Animals were either monitored for 24-h survival, scheduled for electroencephalography (EEG) recording, or euthanized 60 min later for measurement of indirectly-elicited muscle tension in the hemidiaphragm. Post-exposure GAL therapy produced a dose-dependent increase in survival from lethal VX challenge. Optimal clinical benefits were observed in the presence of 10 mg/kg GAL, which led to 100% survival of VX-challenged guinea pigs. Based on muscle physiology studies, GAL post-exposure treatment protected the guinea pig diaphragm, the major effector muscle of respiration, from fatigue, tetanic fade, and muscular paralysis. Protection against the paralyzing effects of VX was dose-dependent. In EEG studies, GAL did not alter seizure onset for all doses tested. At the highest dose tested (10 mg/kg), GAL decreased seizure duration when administered as a post-exposure treatment 1 min after VX. GAL also reduced the high correlation associated between seizure activity and lethality after 2LD50 VX challenge. GAL may have additional benefits both centrally and peripherally that are unrelated to its established mechanism as a reversible acetylcholinesterase inhibitor (AChEI).

2'-O-[2-[2-(N,N-Dimethylamino)ethoxy]ethyl] Modified Antisense Oligonucleotides: Symbiosis of Charge Interaction Factors and Stereoelectronic Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prhavc, M.; Prakash, T.P.; Minasov, G.

Oligonucleotides with a novel, 2'-O-[2-[2-(N,N-dimethylamino)ethoxy]ethyl] (2'-O-DMAEOE) modification have been synthesized. This modification, a cationic analogue of the 2'-O-(2-methoxyethyl) (2'-O-MOE) modification, exhibits high binding affinity to target RNA (but not to DNA) and exceptional resistance to nuclease degradation. Analysis of the crystal structure of a self-complementary oligonucleotide containing a single 2'-O-DMAEOE modification explains the importance of charge factors and gauche effects on the observed antisense properties. 2'-O-DMAEOE modified oligonucleotides are ideal candidates for antisense drugs.

Microtropins A-I: 6'-O-(2″S,3″R)-2″-ethyl-2″,3″-dihydroxybutyrates of aliphatic alcohol β-D-glucopyranosides from the branches of Microtropis japonica.

PubMed

Uemura, Yuka; Sugimoto, Sachiko; Matsunami, Katsuyoshi; Otsuka, Hideaki; Takeda, Yoshio; Kawahata, Masatoshi; Yamaguchi, Kentaro

2013-03-01

From the branches of Microtropis japonica (Celastraceae), nine aliphatic glucosides, named microtropins A-I, were isolated. The 6-position of glucose was esterified with (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid. Microtropins A-D contained a rare natured product nitrile functional group in their aglycones. The absolute structures of the (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid moiety and aglycone of microtropin A were determined by an X-ray crystallographic method. Copyright © 2012 Elsevier Ltd. All rights reserved.

Decomposition of adsorbed VX on activated carbons studied by {sup 31}P MAS NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishay Columbus; Daniel Waysbort; Liora Shmueli

2006-06-15

The fate of the persistent OP nerve agent O-ethyl S-(2-(diisopropylamino)ethyl) methylphosphonothioate (VX) on granular activated carbons that are used for gas filtration was studied by means of 31P magic angle spinning (MAS) NMR spectroscopy. Four types of activated carbon were used, including coal-based BPL. VX as vapor or liquid was adsorbed on carbon granules, and MAS NMR spectra were recorded periodically. The results show that at least 90% of the adsorbed VX decomposes within 20 days or less to the nontoxic ethyl methylphosphonic acid (EMPA) and bis(S-2-diisopropylaminoethane) ((DES){sub 2}). Decomposition occurred irrespective of the phase from which VX was loaded,more » the presence of metal impregnation on the carbon surface, and the water content of the carbon. Theoretical and practical aspects of the degradation are discussed. 17 refs., 6 figs., 3 tabs.« less

Galantamine is a novel post-exposure therapeutic against lethal VX challenge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hilmas, Corey J.; Poole, Melissa J.; Finneran, Kathryn

2009-10-15

The ability of galantamine hydrobromide (GAL HBr) treatment to antagonize O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX)-induced lethality, impairment of muscle tension, and electroencephalographic (EEG) changes was assessed in guinea pigs. Guinea pigs were challenged with 16.8 {mu}g/kg VX (2LD50). One min after challenge, animals were administered 0.5 mg/kg atropine sulfate (ATR) and 25 mg/kg pyridine-2-aldoxime methochloride (2-PAM). In addition, guinea pigs were given 0, 1, 2, 4, 8 or 10 mg/kg GAL as a post-exposure treatment immediately prior to ATR and 2-PAM. Animals were either monitored for 24-h survival, scheduled for electroencephalography (EEG) recording, or euthanized 60 min later for measurement of indirectly-elicitedmore » muscle tension in the hemidiaphragm. Post-exposure GAL therapy produced a dose-dependent increase in survival from lethal VX challenge. Optimal clinical benefits were observed in the presence of 10 mg/kg GAL, which led to 100% survival of VX-challenged guinea pigs. Based on muscle physiology studies, GAL post-exposure treatment protected the guinea pig diaphragm, the major effector muscle of respiration, from fatigue, tetanic fade, and muscular paralysis. Protection against the paralyzing effects of VX was dose-dependent. In EEG studies, GAL did not alter seizure onset for all doses tested. At the highest dose tested (10 mg/kg), GAL decreased seizure duration when administered as a post-exposure treatment 1 min after VX. GAL also reduced the high correlation associated between seizure activity and lethality after 2LD50 VX challenge. GAL may have additional benefits both centrally and peripherally that are unrelated to its established mechanism as a reversible acetylcholinesterase inhibitor (AChEI)« less

Active anatase (0 0 1)-like surface of hydrothermally synthesized titania nanotubes

NASA Astrophysics Data System (ADS)

Chen, Qiang; Mogilevsky, Gregory; Wagner, George W.; Forstater, Jacob; Kleinhammes, Alfred; Wu, Yue

2009-11-01

Using 31P and 13C NMR with DFT calculations we demonstrate the exposed surface of titania nanotubes (TiNTs) is a stable, unterminated anatase (0 0 1)-like surface and is catalytically active under ambient conditions. We find that methanol dissociatively adsorbs on the surface of TiNTs agreeing with the predicted activity of surface dissociation of organic molecules on the crystalline (0 0 1)-anatase surface. We further examined the catalytic activity of anatase power, TiNT, and nanosheets in catalytic hydrolysis of S-[2-(diisopropylamino)ethyl]- O-ethyl methylphosphonothioate (VX) via 31P NMR and demonstrate that titanate-like nanosheets are inactive in the reaction owing to their hydroxylated (0 0 1) surface.

Role of the Cu-ZrO 2 Interfacial Sites for Conversion of Ethanol to Ethyl Acetate and Synthesis of Methanol from CO 2 and H 2 [The Role of the Cu-ZrO 2 Interfacial Sites for Ethanol Conversion to Ethyl Acetate and Methanol Synthesis from CO 2 and H 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ro, Insoo; Liu, Yifei; Ball, Madelyn R.

Well-defined Cu catalysts containing different amounts of zirconia were synthesized by controlled surface reactions (CSRs) and atomic layer deposition methods and studied for the selective conversion of ethanol to ethyl acetate and for methanol synthesis. Selective deposition of ZrO 2 on undercoordinated Cu sites or near Cu nanoparticles via the CSR method was evidenced by UV–vis absorption spectroscopy, scanning transmission electron microscopy, and inductively coupled plasma absorption emission spectroscopy. The concentrations of Cu and Cu-ZrO 2 interfacial sites were quantified using a combination of subambient CO Fourier transform infrared spectroscopy and reactive N 2O chemisorption measurements. The oxidation states ofmore » the Cu and ZrO 2 species for these catalysts were determined using X-ray absorption near edge structure measurements, showing that these species were present primarily as Cu 0 and Zr 4+, respectively. Here, it was found that the formation of Cu-ZrO 2 interfacial sites increased the turnover frequency by an order of magnitude in both the conversion of ethanol to ethyl acetate and the synthesis of methanol from CO 2 and H 2.« less

Role of the Cu-ZrO 2 Interfacial Sites for Conversion of Ethanol to Ethyl Acetate and Synthesis of Methanol from CO 2 and H 2 [The Role of the Cu-ZrO 2 Interfacial Sites for Ethanol Conversion to Ethyl Acetate and Methanol Synthesis from CO 2 and H 2

DOE PAGES

Ro, Insoo; Liu, Yifei; Ball, Madelyn R.; ...

2016-09-06

Well-defined Cu catalysts containing different amounts of zirconia were synthesized by controlled surface reactions (CSRs) and atomic layer deposition methods and studied for the selective conversion of ethanol to ethyl acetate and for methanol synthesis. Selective deposition of ZrO 2 on undercoordinated Cu sites or near Cu nanoparticles via the CSR method was evidenced by UV–vis absorption spectroscopy, scanning transmission electron microscopy, and inductively coupled plasma absorption emission spectroscopy. The concentrations of Cu and Cu-ZrO 2 interfacial sites were quantified using a combination of subambient CO Fourier transform infrared spectroscopy and reactive N 2O chemisorption measurements. The oxidation states ofmore » the Cu and ZrO 2 species for these catalysts were determined using X-ray absorption near edge structure measurements, showing that these species were present primarily as Cu 0 and Zr 4+, respectively. Here, it was found that the formation of Cu-ZrO 2 interfacial sites increased the turnover frequency by an order of magnitude in both the conversion of ethanol to ethyl acetate and the synthesis of methanol from CO 2 and H 2.« less

Degradation mechanism of alachlor during direct ozonation and O(3)/H(2)O(2) advanced oxidation process.

PubMed

Qiang, Zhimin; Liu, Chao; Dong, Bingzhi; Zhang, Yalei

2010-01-01

The degradation of alachlor by direct ozonation and advanced oxidation process O(3)/H(2)O(2) was investigated in this study with focus on identification of degradation byproducts. The second-order reaction rate constant between ozone and alachlor was determined to be 2.5+/-0.1M(-1)s(-1) at pH 7.0 and 20 degrees C. Twelve and eight high-molecular-weight byproducts (with the benzene ring intact) from alachlor degradation were identified during direct ozonation and O(3)/H(2)O(2), respectively. The common degradation byproducts included N-(2,6-diethylphenyl)-methyleneamine, 8-ethyl-3,4-dihydro-quinoline, 8-ethyl-quinoline, 1-chloroacetyl-2-hydro-3-ketone-7-acetyl-indole, 2-chloro-2',6'-diacetyl-N-(methoxymethyl)acetanilide, 2-chloro-2'-acetyl-6'-ethyl-N-(methoxymethyl)-acetanilide, and two hydroxylated alachlor isomers. In direct ozonation, four more byproducts were also identified including 1-chloroacetyl-2,3-dihydro-7-ethyl-indole, 2-chloro-2',6'-ethyl-acetanilide, 2-chloro-2',6'-acetyl-acetanilide and 2-chloro-2'-ethyl-6'-acetyl-N-(methoxymethyl)-acetanilide. Degradation of alachlor by O(3) and O(3)/H(2)O(2) also led to the formation of low-molecular-weight byproducts including formic, acetic, propionic, monochloroacetic and oxalic acids as well as chloride ion (only detected in O(3)/H(2)O(2)). Nitrite and nitrate formation was negligible. Alachlor degradation occurred via oxidation of the arylethyl group, N-dealkylation, cyclization and cleavage of benzene ring. After O(3) or O(3)/H(2)O(2) treatment, the toxicity of alachlor solution examined by the Daphnia magna bioassay was slightly reduced. 2009 Elsevier Ltd. All rights reserved.

Crystal structure of ethyl (E)-2-cyano-3-(thio-phen-2-yl)acrylate: two conformers forming a discrete disorder.

PubMed

Castro Agudelo, Brian; Cárdenas, Juan C; Macías, Mario A; Ochoa-Puentes, Cristian; Sierra, Cesar A

2017-09-01

In the title compound, C 10 H 9 NO 2 S, all the non-H atoms, except for the ethyl fragment, lie nearly in the same plane. Despite the mol-ecular planarity, the ethyl fragment presents more than one conformation, giving rise to a discrete disorder, which was modelled with two different crystallographic sites for the eth-oxy O and eth-oxy α-C atoms, with occupancy values of 0.5. In the crystal, the three-dimensional array is mainly directed by C-H⋯(O,N) inter-actions, giving rise to inversion dimers with R 2 2 (10) and R 2 2 (14) motifs and infinite chains running along the [100] direction.

S-Ethyl dipropylthiocarbamate (EPTC)

Integrated Risk Information System (IRIS)

Integrated Risk Information System ( IRIS ) Chemical Assessment Summary U.S . Environmental Protection Agency National Center for Environmental Assessment This IRIS Summary has been removed from the IRIS database and is available for historical reference purposes . ( July 2016 ) S - Ethyl dipropylth

Studies on residue-free decontaminants for chemical warfare agents.

PubMed

Wagner, George W

2015-03-17

Residue-free decontaminants based on hydrogen peroxide, which decomposes to water and oxygen in the environment, are examined as decontaminants for chemical warfare agents (CWA). For the apparent special case of CWA on concrete, H2O2 alone, without any additives, effectively decontaminates S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate (VX), pinacolyl methylphosphorofluoridate (GD), and bis(2-choroethyl) sulfide (HD) in a process thought to involve H2O2 activation by surface-bound carbonates/bicarbonates (known H2O2 activators for CWA decontamination). A plethora of products are formed during the H2O2 decontamination of HD on concrete, and these are characterized by comparison to synthesized authentic compounds. As a potential residue-free decontaminant for surfaces other than concrete (or those lacking adsorbed carbonate/bicarbonate) H2O2 activation for CWA decontamination is feasible using residue-free NH3 and CO2 as demonstrated by reaction studies for VX, GD, and HD in homogeneous solution. Although H2O2/NH3/CO2 ("HPAC") decontaminants are active for CWA decontamination in solution, they require testing on actual surfaces of interest to assess their true efficacy for surface decontamination.

A semisynthesis of 3'-O-ethyl-5,6-dihydrospinosyn J based on the spinosyn A aglycone.

PubMed

Zhang, Kai; Liu, Shenglan; Liu, Anjun; Chai, Hongxin; Li, Jiarong; A, Lamusi

2017-01-01

Spinetoram, a mixture of 3'- O -ethyl-5,6-dihydrospinosyn J (XDE-175-J, major component) and 3'- O -ethylspinosyn L (XDE-175-L, minor component), is a novel kind of green and efficient insecticide with a broad range of action against various insects. Nowadays, spinetoram is widely used in agriculture and food storage. This work reports a 7-step semisynthesis of 3'- O -ethyl-5,6-dihydrospinosyn J from spinosyn A aglycone. The C9-OH and C17-OH of the aglycone are successively connected to 3- O -ethyl-2,4-di- O -methylrhamnose and D-forosamine after selective protection and deprotection steps. Then, with 10% Pd/C as catalyst, the 5,6-double bond of the macrolide was selectively reduced to afford 3'- O -ethyl-5,6-dihydrospinosyn J. In addition, the 3- O -ethyl-2,4-di- O -methylrhamnose is synthesized from rhamnose which is available commercially, while the D-forosamine and aglycone are obtained via the hydrolysis of spinosyn A. High yields were obtained in each step, and all intermediates in the synthesis were characterized by 1 H NMR, 13 C NMR and MS techniques. This study can be helpful for developing an efficient chemical synthesis of spinetoram, and it also offers opportunities to synthesize spinosyn analogues and rhamnose derivatives.

Biocatalytic Asymmetric Synthesis of (1R, 2S)-N-Boc-vinyl-ACCA Ethyl Ester with a Newly Isolated Sphingomonas aquatilis.

PubMed

Zhu, Shaozhou; Shi, Ying; Zhang, Xinyu; Zheng, Guojun

2018-02-01

1-amino cyclopropane-1-carboxylic acid (ACCA) and its derivatives are essential pharmacophoric unit that widely used in drug research and development. Specifically, (1R, 2S)-N-Boc-vinyl-ACCA ethyl ester (vinyl-ACCA) is a key chiral intermediate in the synthesis of highly potent hepatitis C virus (HCV) NS3/4A protease inhibitors such as asunaprevir and simeprevir. Developing strategies for the asymmetric synthesis of vinyl-ACCA is thus extremely high demand. In this study, 378 bacterial strains were isolated from soil samples using N-Boc-vinyl-ACCA ethyl ester as the sole carbon source and were screened for esterase activity. Fourteen of which worked effectively for the asymmetric synthesis of (1R, 2S)-N-Boc-1-vinyl ACCA ethyl ester. The strain CY-2, identified as Sphingomonas aquatilis, which showed the highest stability and enantioselectivity was selected as whole cell biocatalyst for further study. A systematic study of all factors influencing the enzymatic hydrolysis was performed. Under optimized conditions, resolution of rac-vinyl-ACCA to (1R, 2S)-N-Boc-1-vinyl ACCA ethyl ester with 88.2% ee and 62.4% conversion (E = 9) was achieved. Besides, S. aquatilis was also used to transform other 10 different substrates. Notably, it was found that 7 of them could be stereoselectively hydrolyzed, especially for (1R,2S)-1-amino-vinyl-ACCA ethyl ester hydrochloride (99.6% ee, E>200). Our investigations provide a new efficient whole cell biocatalyst for resolution of ACCA and might be developed for industry application.

The sources, fate, and toxicity of chemical warfare agent degradation products.

PubMed Central

Munro, N B; Talmage, S S; Griffin, G D; Waters, L C; Watson, A P; King, J F; Hauschild, V

1999-01-01

We include in this review an assessment of the formation, environmental fate, and mammalian and ecotoxicity of CW agent degradation products relevant to environmental and occupational health. These parent CW agents include several vesicants: sulfur mustards [undistilled sulfur mustard (H), sulfur mustard (HD), and an HD/agent T mixture (HT)]; nitrogen mustards [ethylbis(2-chloroethyl)amine (HN1), methylbis(2-chloroethyl)amine (HN2), tris(2-chloroethyl)amine (HN3)], and Lewisite; four nerve agents (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX), tabun (GA), sarin (GB), and soman (GD)); and the blood agent cyanogen chloride. The degradation processes considered here include hydrolysis, microbial degradation, oxidation, and photolysis. We also briefly address decontamination but not combustion processes. Because CW agents are generally not considered very persistent, certain degradation products of significant persistence, even those that are not particularly toxic, may indicate previous CW agent presence or that degradation has occurred. Of those products for which there are data on both environmental fate and toxicity, only a few are both environmentally persistent and highly toxic. Major degradation products estimated to be of significant persistence (weeks to years) include thiodiglycol for HD; Lewisite oxide for Lewisite; and ethyl methyl phosphonic acid, methyl phosphonic acid, and possibly S-(2-diisopropylaminoethyl) methylphosphonothioic acid (EA 2192) for VX. Methyl phosphonic acid is also the ultimate hydrolysis product of both GB and GD. The GB product, isopropyl methylphosphonic acid, and a closely related contaminant of GB, diisopropyl methylphosphonate, are also persistent. Of all of these compounds, only Lewisite oxide and EA 2192 possess high mammalian toxicity. Unlike other CW agents, sulfur mustard agents (e.g., HD) are somewhat persistent; therefore, sites or conditions involving potential HD contamination should include an

Development of a gas-cylinder-free plasma desorption/ionization system for on-site detection of chemical warfare agents.

PubMed

Iwai, Takahiro; Kakegawa, Ken; Aida, Mari; Nagashima, Hisayuki; Nagoya, Tomoki; Kanamori-Kataoka, Mieko; Miyahara, Hidekazu; Seto, Yasuo; Okino, Akitoshi

2015-06-02

A gas-cylinder-free plasma desorption/ionization system was developed to realize a mobile on-site analytical device for detection of chemical warfare agents (CWAs). In this system, the plasma source was directly connected to the inlet of a mass spectrometer. The plasma can be generated with ambient air, which is drawn into the discharge region by negative pressure in the mass spectrometer. High-power density pulsed plasma of 100 kW could be generated by using a microhollow cathode and a laboratory-built high-intensity pulsed power supply (pulse width: 10-20 μs; repetition frequency: 50 Hz). CWAs were desorbed and protonated in the enclosed space adjacent to the plasma source. Protonated sample molecules were introduced to the mass spectrometer by airflow through the discharge region. To evaluate the analytical performance of this device, helium and air plasma were directly irradiated to CWAs in the gas-cylinder-free plasma desorption/ionization system and the protonated molecules were analyzed by using an ion-trap mass spectrometer. A blister agent (nitrogen mustard 3) and nerve gases [cyclohexylsarin (GF), tabun (GA), and O-ethyl S-2-N,N-diisopropylaminoethyl methylphosphonothiolate (VX)] in solution in n-hexane were applied to the Teflon rod and used as test samples, after solvent evaporation. As a result, protonated molecules of CWAs were successfully observed as the characteristic ion peaks at m/z 204, 181, 163, and 268, respectively. In air plasma, the limits of detection were estimated to be 22, 20, 4.8, and 1.0 pmol, respectively, which were lower than those obtained with helium plasma. To achieve quantitative analysis, calibration curves were made by using CWA stimulant dipinacolyl methylphosphonate as an internal standard; straight correlation lines (R(2) = 0.9998) of the peak intensity ratios (target per internal standard) were obtained. Remarkably, GA and GF gave protonated dimer ions, and the ratios of the protonated dimer ions to the protonated

Role of the P-F bond in fluoride-promoted aqueous VX hydrolysis: an experimental and theoretical study.

PubMed

Marciano, Daniele; Columbus, Ishay; Elias, Shlomi; Goldvaser, Michael; Shoshanim, Ofir; Ashkenazi, Nissan; Zafrani, Yossi

2012-11-16

Following our ongoing studies on the reactivity of the fluoride ion toward organophosphorus compounds, we established that the extremely toxic and environmentally persistent chemical warfare agent VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate) is exclusively and rapidly degraded to the nontoxic product EMPA (ethyl methylphosphonic acid) even in dilute aqueous solutions of fluoride. The unique role of the P-F bond formation in the reaction mechanism was explored using both experimental and computational mechanistic studies. In most cases, the "G-analogue" (O-ethyl methylphosphonofluoridate, Et-G) was observed as an intermediate. Noteworthy and of practical importance is the fact that the toxic side product desethyl-VX, which is formed in substantial quantities during the slow degradation of VX in unbuffered water, is completely avoided in the presence of fluoride. A computational study on a VX-model, O,S-diethyl methylphosphonothioate (1), clarifies the distinctive tendency of aqueous fluoride ions to react with such organophosphorus compounds. The facility of the degradation process even in dilute fluoride solutions is due to the increased reactivity of fluoride, which is caused by the significant low activation barrier for the P-F bond formation. In addition, the unique nucleophilicity of fluoride versus hydroxide toward VX, in contrast to their relative basicity, is discussed. Although the reaction outcomes were similar, much slower reaction rates were observed experimentally for the VX-model (1) in comparison to VX.

Reactivity of 2-ethyl-1-hexanol in the atmosphere.

PubMed

Gallego-Iniesta García, María Paz; Moreno Sanroma, Alberto; Martín Porrero, María Pilar; Tapia Valle, Araceli; Cabañas Galán, Beatriz; Salgado Muñoz, María Sagrario

2010-04-07

Rate coefficients at room temperature for the reaction of 2-ethyl-1-hexanol with OH and NO(3) radicals and with Cl atoms have been determined in a 150 L PTFE chamber using GC-FID/SPME and FTIR as detection systems. The rate coefficients k (in units of cm(3) molecule(-1) s(-1)) obtained were: (1.13 +/- 0.31) 10(-11) for the OH reaction, (2.93 +/- 0.92) 10(-15) for the NO(3) reaction and (1.88 +/- 0.25) 10(-10) for the Cl reaction. Despite the high concentrations of 2-ethyl-1-hexanol, especially in indoor air, this is the first kinetic study carried out to date for these reactions. The results are consistent with the expected reactivity given the chemical structure of 2-ethyl-1-hexanol. Calculated atmospheric lifetimes reveal that the dominant loss process for 2-ethyl-1-hexanol is clearly the daytime reaction with the hydroxyl radical.

Absorption of the nerve agent VX (O-ethyl-S-[2(di-isopropylamino)ethyl] methyl phosphonothioate) through pig, human and guinea pig skin in vitro.

PubMed

Dalton, Christopher H; Hattersley, Ian J; Rutter, Stephen J; Chilcott, Robert P

2006-12-01

The physico-chemical properties of VX make the skin the most likely route of absorption into the human body. The development of effective medical countermeasures against such percutaneous threat agents relies on the use of appropriate animal models, as the inherent toxicity of nerve agents precludes the use of human volunteers. Previous studies have characterised the mechanism of nerve agent toxicity in rodent models, however, it is generally accepted that one of the most appropriate animal models for human skin absorption is the domestic pig. The purpose of the present study was to measure and compare the skin absorption kinetics of VX in vitro using pig, human and guinea pig skin to highlight any potential species differences in skin permeability. When undiluted VX was applied directly to the skin, the permeability of guinea pig skin was approximately 7-fold greater than human skin. There was no significant difference in the permeability of pig and human skin. When VX diluted with isopropyl alcohol was applied to the skin, the permeability of guinea pig skin was approximately 4-fold greater than human skin. There was no significant difference in the permeability of pig and human skin. From this data it may be inferred that dermatomed, abdominal pig skin is an appropriate model for the human skin absorption of VX.

40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

Code of Federal Regulations, 2013 CFR

2013-07-01

...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates...

40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

Code of Federal Regulations, 2014 CFR

2014-07-01

...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates...

40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

Code of Federal Regulations, 2012 CFR

2012-07-01

...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates...

40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

Code of Federal Regulations, 2011 CFR

2011-07-01

...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates...

Ethyl caffeate suppresses NF-kappaB activation and its downstream inflammatory mediators, iNOS, COX-2, and PGE2 in vitro or in mouse skin.

PubMed

Chiang, Yi-Ming; Lo, Chiu-Ping; Chen, Yi-Ping; Wang, Sheng-Yang; Yang, Ning-Sun; Kuo, Yueh-Hsiung; Shyur, Lie-Fen

2005-10-01

Ethyl caffeate, a natural phenolic compound, was isolated from Bidens pilosa, a medicinal plant popularly used for treating certain inflammatory syndromes. The purpose of this study was to investigate the structural activity, and the anti-inflammatory functions and mechanism(s) of ethyl caffeate. Ethyl caffeate was found to markedly suppress the lipopolysaccharide (LPS)-induced nitric oxide (NO) production (IC(50) = 5.5 microg ml(-1)), mRNA and protein expressions of inducible nitric oxide synthase (iNOS), and prostaglandin E(2) (PGE(2)) production in RAW 264.7 macrophages. Transient gene expression assays using human cox-2 promoter construct revealed that ethyl caffeate exerted an inhibitory effect on cox-2 transcriptional activity in 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated MCF-7 cells. Immunohistochemical studies of mouse skin demonstrated that TPA-induced COX-2 expression was significantly inhibited by ethyl caffeate with a superior effect to that of celecoxib, a nonsteroidal anti-inflammatory drug. The phosphorylation and degradation of inhibitor kappaB (IkappaB) and the translocation of nuclear transcription factor-kappaB (NF-kappaB) into the nucleus, as well as the activation of mitogen-activated protein kinases (MAPKs) induced by LPS in macrophages, were not affected by ethyl caffeate. Ethyl caffeate, however, could inhibit NF-kappaB activation by impairing the binding of NF-kappaB to its cis-acting element. These results suggest that ethyl caffeate suppresses iNOS and COX-2 expressions partly through the inhibition of the NF-kappaB.DNA complex formation. Structure-activity relationship analyses suggested that the catechol moiety and alpha,beta-unsaturated ester group in ethyl caffeate are important and essential structural features for preventing NF-kappaB.DNA complex formation. This study provides an insight into the probable mechanism(s) underlying the anti-inflammatory and therapeutic properties of ethyl caffeate.

D2 dopaminergic and 5-HT1A serotonergic activity of 2-(1-naphthyl)ethyl- and 2-(2-naphthyl)ethyl amines.

PubMed

Šukalović, V; Roglić, G; Husinec, S; Kostić-Rajaćić, S; Andrić, D; Šoškić, Vukić

2003-11-01

Several tertiary 2-phenylethyl, 2-(1-naphthyl)ethyl and 2-(2-naphthyl)ethyl amines were synthesized and their binding affinities for dopamine D(1), D(2) and serotonin 5-HT(1A) receptors evaluated in radioligand binding assays. All compounds were inactive in D(1) dopamine radioligand binding assay. The 2-(1-naphthyl)ethyl analogues expressed a low but significant binding affinity for the D(2) and moderate one for the 5-HT(1A) receptor subtypes. Most of the remaining compounds expressed binding affinity at the 5-HT(1A) receptor subtype but were inactive in D(2) receptor binding assay. Based on these results and considering the chemical characteristics of the compounds synthesized and evaluated for dopaminergic and serotonergic activity throughout the present study it can be concluded that hydrophobic type of interaction (stacking or edge-to-face) plays a significant role in the formation of receptor-ligand complexes of 2-(1-naphthyl)ethyl amines. This structural motive can be applied to design and synthesize new, more potent dopaminergic/serotonergic ligands by slight chemical modifications.

S-Nitroso-N-acetyl-L-cysteine ethyl ester (SNACET) and N-acetyl-L-cysteine ethyl ester (NACET)-Cysteine-based drug candidates with unique pharmacological profiles for oral use as NO, H2S and GSH suppliers and as antioxidants: Results and overview.

PubMed

Tsikas, Dimitrios; Schwedhelm, Kathrin S; Surdacki, Andrzej; Giustarini, Daniela; Rossi, Ranieri; Kukoc-Modun, Lea; Kedia, George; Ückert, Stefan

2018-02-01

S -Nitrosothiols or thionitrites with the general formula RSNO are formally composed of the nitrosyl cation (NO + ) and a thiolate (RS - ), the base of the corresponding acids RSH. The smallest S -nitrosothiol is HSNO and derives from hydrogen sulfide (HSH, H 2 S). The most common physiological S -nitrosothiols are derived from the amino acid L-cysteine (CysSH). Thus, the simplest S -nitrosothiol is S -nitroso-L-cysteine (CysSNO). CysSNO is a spontaneous potent donor of nitric oxide (NO) which activates soluble guanylyl cyclase to form cyclic guanosine monophosphate (cGMP). This activation is associated with multiple biological actions that include relaxation of smooth muscle cells and inhibition of platelet aggregation. Like NO, CysSNO is a short-lived species and occurs physiologically at concentrations around 1 nM in human blood. CysSNO can be formed from CysSH and higher oxides of NO including nitrous acid (HONO) and its anhydride (N 2 O 3 ). The most characteristic feature of RSNO is the S-transnitrosation reaction by which the NO + group is reversibly transferred to another thiolate. By this way numerous RSNO can be formed such as the low-molecular-mass S -nitroso- N -acetyl-L-cysteine (SNAC) and S -nitroso-glutathione (GSNO), and the high-molecular-mass S -nitrosol-L-cysteine hemoglobin (HbCysSNO) present in erythrocytes and S -nitrosol-L-cysteine albumin (AlbCysSNO) present in plasma at concentrations of the order of 200 nM. All above mentioned RSNO exert NO-related biological activity, but they must be administered intravenously. This important drawback can be overcome by lipophilic charge-free RSNO. Thus, we prepared the ethyl ester of SNAC, the S -nitroso- N -acetyl-L-cysteine ethyl ester (SNACET), from synthetic N -acetyl-L-cysteine ethyl ester (NACET). Both NACET and SNACET have improved pharmacological features over N -acetyl-L-cysteine (NAC) and S -nitroso- N -acetyl-L-cysteine (SNAC), respectively, including higher oral bioavailability. SNACET

The effect of malathion on the activity, performance, and microbial ecology of activated sludge

PubMed Central

Rauglas, Erik; Martin, Seth; Bailey, Kandace; Magnuson, Matthew; Phillips, Rebecca; Harper, Willie F.

2018-01-01

This study evaluated the effect of a VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) surrogate (malathion) on the activity, performance, and ecology of activated sludge bioreactors. In the presence of malathion, the maximum observed respiration rates varied between 43 and 53 μg/O2 min, generally similar to the 49 μg O2/min rates observed in controls. Malathion did not alter the respiration ratio of O2 consumed-to-CO2 produced nor did it impact the shape of the oxygen consumption curves during respirometry. Shorter term (12 h) batch tests showed that both chemical oxygen demand (COD) and ammonia removal were not negatively impacted by the presence of 0.1–3 mg/L malathion. Longer term continuous addition (i.e. 40 days) of 0.1 mg/L of malathion also had no effect on COD and ammonia removal. In contrast to shorter term exposures, longer term continuous addition of 3 mg/L of malathion negatively impacted both COD and nitrogen removal and was associated with shifts in the abundance of species that are common to activated sludge. These results illustrate the impact that chemicals like malathion may have on COD removal, and nitrification, as well as the robustness of activated sludge microbial communities. PMID:27594690

Multicomponent Diffusion of Penetrant Mixtures in Rubbery Polymers: A Molecular Dynamics Study

NASA Astrophysics Data System (ADS)

Bringuier, Stefan; Varady, Mark; Knox, Craig; Cabalo, Jerry; Pearl, Thomas; Mantooth, Brent

The importance of understanding transport of chemical species across liquid-solid boundaries is of particular interest in the decontamination of harmful chemicals absorbed within polymeric materials. To characterize processes associated with liquid-phase extraction of absorbed species from polymers, it is necessary to determine an appropriate physical description of species transport in multicomponent systems. The Maxwell-Stefan (M-S) formulation is a rigorous description of mass transport in multicomponent solutions, in which, mutual diffusivities determine the degree of relative motion between interacting molecules in response to a chemical potential gradient. The work presented focuses on the determination of M-S diffusivities from molecular dynamics (MD) simulations of nerve agent O-ethyl S-[2(diisopropylamino)ethyl] methylphosphonothioate (VX), water, and methanol mixtures within a poly(dimethylsiloxane) matrix. We investigate the composition dependence of M-S diffusivities and compare the results to values predicted using empirical relations for binary and ternary mixtures. Finally, we highlight the pertinent differences in molecular mechanisms associated with species transport and employ non-equilibrium MD to probe transport across the mixture-polymer interface.

Electron excitation cross sections for the 2s(2)2p(3)4S(O) -- 2s(2)2p(3)2D(O) (forbidden) and 4S(O) -- 2s2p(4) 4P (resonance) transitions in O II

NASA Technical Reports Server (NTRS)

Zuo, M.; Smith, Steven J.; Chutjian, A.; Williams, I. D.; Tayal, S. S.; Mclaughlin, Brendan M.

1995-01-01

Experimental and theoretical excitation cross sections are reported for the first forbidden transition 4S(O) -- 2S(2)2p(3) 2D(O) (lambda-lambda 3726, 3729) and the first allowed (resonance) transition 4S(O) -- 2s2p(4) 4P(lambda-833) in O II. Use is made of electron energy loss and merged-beams methods. The electron energy range covered is 3.33 (threshold) to 15 eV for the S -- D transition, and 14.9 (threshold) to 40 eV for the S -- P transition. Care was taken to assess and minimize the metastable fraction of the O II beam. An electron mirror was designed and tested to reflect inelastically backscattered electrons into the forward direction to account for the full range of polar scattering angles. Comparisons are made between present experiments and 11-state R-matrix calculations. Calculations are also presented for the 4S(O) -- 2s(2)2p(3)2P(O) (lambda-2470) transition.

Crystal structure of bis-(3-bromo-pyridine-κN)bis-(O-ethyl di-thio-carbonato-κ(2) S,S')nickel(II).

PubMed

Kant, Rajni; Kour, Gurvinder; Anthal, Sumati; Neerupama; Sachar, Renu

2015-01-01

In the title mol-ecular complex, [Ni(C3H5OS2)2(C5H4BrN)2], the Ni(2+) cation is located on a centre of inversion and has a distorted octa-hedral N2S4 environment defined by two chelating xanthate ligands and two monodentate pyridine ligands. The C-S bond lengths of the thio-carboxyl-ate group are indicative of a delocalized bond and the O-Csp (2) bond is considerably shorter than the O-Csp (3) bond, consistent with a significant contribution of one resonance form of the xanthate anion that features a formal C=O+ unit and a negative charge on each of the S atoms. The packing of the mol-ecules is stabilized by C-H⋯S and C-H⋯π inter-actions. In addition, π-π inter-actions between the pyridine rings [centroid-to-centroid distance = 3.797 (3) Å] are also present. In the crystal structure, mol-ecules are arranged in rows along [100], forming layers parallel to (010) and (001).

Analysis Of The Different Zones Of Glow Discharge Of Ethyl Alcohol (C2H6O)

NASA Astrophysics Data System (ADS)

Torres, C.; Reyes, P. G.; Mulia, J.; Castillo, F.; Martínez, H.

2014-05-01

The aim of this work is to explore the emission spectroscopy of ethyl alcohol in some regions, also is determine the result elements of the glow discharge, the spectrums were observed in a range of 200 at 1100 nm in the different zones inside of the tube at different distances of 20 and 30 cm. The elements are: in anode region C6H5 (483.02nm), CHO (519.56nm) and H2 (560.47nm), in the positive column CO2+ (315.52 y 337.00nm), O+ (357.48nm), CH+ (380.61nm) and CO+ (399.73nm); in the cathode region we observed O+ (391.19nm), CHOCHO (428.00nm), CO+ (471.12nm) and H2 (656.52nm). C6H5, CHO y H2 species occurring in all regions analyzed varying the glow discharge emission intensity.

Thermal decomposition of FC(O)OCH3 and FC(O)OCH2CH3.

PubMed

Berasategui, M; Argüello, G A; Burgos Paci, M A

2018-05-09

The thermal decomposition of methyl and ethyl formates has been extensively studied due to their importance in the oxidation of several fuels, pesticidal properties and their presence in interstellar space. We hitherto present the study of the thermal decomposition of methyl and ethyl fluoroformates, which could help in the elucidation of the reaction mechanisms. The reaction mechanisms were studied using FTIR spectroscopy in the temperature range of 453-733 K in the presence of different pressures of N2 as bath gas. For FC(O)OCH3 two different channels were observed; the unimolecular decomposition which is favored at higher temperatures and has a rate constant kFC(O)OCH3 = (5.3 ± 0.5) × 1015 exp[-(246 ± 10 kJ mol-1/RT)] (in units of s-1) and a bimolecular channel with a rate constant kFC(O)OCH3 = (1.6 ± 0.5) × 1011 exp[-(148 ± 10 kJ mol-1/RT)] (in units of s-1 (mol L)-1). However for ethyl formate, only direct elimination of CO2, HF and ethylene operates. The rate constants of the homogeneous first-order process fit the Arrhenius equation kFC(O)OCH2CH3 = (2.06 ± 0.09) × 1013 exp[-(169 ± 6 kJ mol-1/RT)] (in units of s-1). The difference between the mechanisms of the two fluoroformates relies on the stabilization of a six-centered transition state that only exists for ethyl formate. First principles calculations for the different channels were carried out to understand the dynamics of the decomposition.

Crystal structure of ethyl (E)-4-(4-chlorophen-yl)-4-meth-oxy-2-oxobut-3-enoate.

PubMed

Flores, Darlene Correia; Vicenti, Juliano Rosa de Menezes; Pereira, Bruna Ávila; da Silva, Gabriele Marques Dias; Zambiazi, Priscilla Jussiane

2014-09-01

In the title compound, C13H13ClO4, the dihedral angle between the chloro-benezene ring and the least-squares plane through the 4-meth-oxy-2-oxobut-3-enoate ethyl ester residue (r.m.s. deviation = 0.0975 Å) is 54.10 (5)°. In the crystal, mol-ecules are connected by meth-oxy-ketone and benzene-carboxyl-ate carbonyl C-H⋯O inter-actions, generating a supra-molecular layer in the ac plane.

Decontamination of 2-Chloroethyl Ethyl Sulfide by Pulsed Corona Plasma

NASA Astrophysics Data System (ADS)

Li, Zhanguo; Hu, Zhen; Cao, Peng; Zhao, Hongjie

2014-11-01

Decontamination of 2-chloroethyl ethyl sulfide (2-CEES, CH3CH2SCH2CH2Cl) by pulsed corona plasma was investigated. The results show that 212.6 mg/m3 of 2-CEES, with the gas flow rate of 2 m3/h, can be decontaminated to 0.09 mg/m3. According to the variation of the inlet and outlet concentration of 2-CEES vapor with retention time, it is found that the reaction of 2-CEES in a pulsed corona plasma system follows the first order reaction, with the reaction rate constant of 0.463 s-1. The decontamination mechanism is discussed based on an analysis of the dissociation energy of chemical bonds and decontamination products. The C-S bond adjacent to the Cl atom will be destroyed firstly to form CH3CH2S· and ·CH2CH2Cl radicals. CH3CH2S· can be decomposed to ·C2H5 and ·S. ·S can be oxidized to SO2, while ·C2H5 can be finally oxidized to CO2 and H2O. The C-Cl bond in the ·CH2CH2Cl radical can be destroyed to form ·CH2CH2. and ·Cl, which can be mineralized to CO2, H2O and HCl. The H atom in the ·CH2CH2Cl radical can also be substituted by ·Cl to form CHCl2-CHCl2.

2′-O-[2-[(N,N-dimethylamino)oxy]ethyl]-modified oligonucleotides inhibit expression of mRNA in vitro and in vivo

PubMed Central

Prakash, Thazha P.; Johnston, Joseph F.; Graham, Mark J.; Condon, Thomas P.; Manoharan, Muthiah

2004-01-01

Synthesis and antisense activity of oligonucleotides modified with 2′-O-[2-[(N,N-dimethylamino)oxy] ethyl] (2′-O-DMAOE) are described. The 2′-O-DMAOE-modified oligonucleotides showed superior metabolic stability in mice. The phosphorothioate oligonucleotide ‘gapmers’, with 2′-O-DMAOE- modified nucleoside residues at the ends and 2′-deoxy nucleosides residues in the central region, showed dose-dependent inhibition of mRNA expression in cell culture for two targets. ‘Gapmer’ oligonucleotides have one or two 2′-O-modified regions and a 2′-deoxyoligonucleotide phosphorothioate region that allows RNase H digestion of target mRNA. To determine the in vivo potency and efficacy, BalbC mice were treated with 2′-O-DMAOE gapmers and a dose-dependent reduction in the targeted C-raf mRNA expression was observed. Oligonucleotides with 2′-O-DMAOE modifications throughout the sequences reduced the intercellular adhesion molecule-1 (ICAM-1) protein expression very efficiently in HUVEC cells with an IC50 of 1.8 nM. The inhibition of ICAM-1 protein expression by these uniformly modified 2′-O-DMAOE oligonucleotides may be due to selective interference with the formation of the translational initiation complex. These results demonstrate that 2′-O-DMAOE- modified oligonucleotides are useful for antisense-based therapeutics when either RNase H-dependent or RNase H-independent target reduction mechanisms are employed. PMID:14762210

Chemo-Enzymatic Synthesis of Chiral Epoxides Ethyl and Methyl (S)-3-(Oxiran-2-yl)propanoates from Renewable Levoglucosenone: An Access to Enantiopure (S)-Dairy Lactone.

PubMed

Peru, Aurélien A M; Flourat, Amandine L; Gunawan, Christian; Raverty, Warwick; Jevric, Martyn; Greatrex, Ben W; Allais, Florent

2016-07-29

Chiral epoxides-such as ethyl and methyl (S)-3-(oxiran-2-yl)propanoates ((S)-1a/1b)-are valuable precursors in many chemical syntheses. Until recently, these compounds were synthesized from glutamic acid in four steps (deamination, reduction, tosylation and epoxide formation) in low to moderate overall yield (20%-50%). Moreover, this procedure requires some harmful reagents such as sodium nitrite ((eco)toxic) and borane (carcinogen). Herein, starting from levoglucosenone (LGO), a biobased chiral compound obtained through the flash pyrolysis of acidified cellulose, we propose a safer and more sustainable chemo-enzymatic synthetic pathway involving lipase-mediated Baeyer-Villiger oxidation, palladium-catalyzed hydrogenation, tosylation and treatment with sodium ethoxide/methoxide as key steps. This route afforded ethyl and methyl (S)-3-(oxiran-2-yl)propanoates in 57% overall yield, respectively. To demonstrate the potentiality of this new synthetic pathway from LGO, the synthesis of high value-added (S)-dairy lactone was undertaken from these epoxides and provided the target in 37% overall yield from LGO.

Prophylactic efficacy of S-2(2-aminoethylamino)ethyl phenyl sulfide (DRDE-07) against sulfur mustard induced lung toxicity in mice.

PubMed

Kannan, G M; Kumar, Pravin; Bhaskar, A S B; Pathak, U; Kumar, Deo; Nagar, D P; Pant, S C; Ganesan, K

2016-01-01

The present study was planned to investigate the prophylactic efficacy of S-2(2-aminoethylamino)ethyl phenyl sulfide (DRDE-07), against topically applied SM induced pulmonary toxicity in mouse. Animals were pretreated with S-2(2-aminoethylamino)ethyl phenyl sulfide (DRDE-07) (249.4 mg/kg by oral gavage) 30 minutes before SM exposure. The SM (6.48 mg/kg) was applied on hair clipped dorsocaudal region (percutaneous) of the animal. The animals were sacrificed on day 1, 3, 5 and 7. The biochemical changes those were observed in the bronchoalveolar lavage (BAL) fluid and lung tissue included protein, LDH, MPO, β-glucuronidase, MMP-2, MMP-9, activated macrophages, reduced glutathione and lipid peroxidation level. Pretreatment with DRDE-07 (0.2 LD50) attenuated SM-induced changes at all time point tested. BAL fluid biochemical endpoints indicated epithelial and endothelial cell damages as evidenced by increase in BAL protein, LDH level and increased number of activated macrophages. The increased myeloperoxidase activity and β-glucuronidase level exhibited the degranulation of neutrophils due to SM toxicity in lung. The zymogrphy analysis of BAL fluid showed a significant increase in matrix metalloproteases (MMP) activity due to inflammatory cells accumulation. Thirty minutes pretreatment with DRDE-07 decreased vascular permeability reduced the inflammation and oxidative stress, hence may be recommended as a potential prophylactic agent for SM intoxication.

Photoluminescence of Co: ZnNiO and Zr: ZnNiO nanocomposites capped with biodegradable polymer poly (2-ethyl-2-oxazoline)

NASA Astrophysics Data System (ADS)

John, Sam; George, James Baben; Joseph, Abraham

2018-05-01

The optical properties of the semiconducting nanomaterials has a wide variety of applications in the biological and industrial fields, which include the synthesis of UV laser, light emitting diodes, solar cells, gas sensors, piezoelectric transducers etc. Among the various types of optical properties, luminescence especially photoluminescence (PL) of metal oxides are more prominently studied. This is because PL spectrum is an effective way to investigate the electronic structure, optical and photochemical properties of semiconductor materials which deciphers information such as surface oxygen vacancies, defects, efficiency of charge carrier trapping, immigration, transfer etc. To overcome the drawbacks in luminescence studies of metal oxide nanomaterials, polymer technology has also been incorporated. The scientists found that the doping of some elements into the polymer capped ZnO nanocomposites enhanced the luminescence properties of the compound. In the current study, we are investigating the photoluminescence properties of ZnO nanocomposites capped with a biodegradable polymer poly (2-ethyl 2-oxazoline) and doped with the elements Cobalt and Zirconium. We obtained many strong fluorescence peaks in the visible and UV regions in the PL spectrum and UV absorption spectroscopy.

The effect of malathion on the activity, performance, and microbial ecology of activated sludge.

PubMed

Rauglas, Erik; Martin, Seth; Bailey, Kandace; Magnuson, Matthew; Phillips, Rebecca; Harper, Willie F

2016-12-01

This study evaluated the effect of a VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) surrogate (malathion) on the activity, performance, and ecology of activated sludge bioreactors. In the presence of malathion, the maximum observed respiration rates varied between 43 and 53 μg/O2 min, generally similar to the 49 μg O2/min rates observed in controls. Malathion did not alter the respiration ratio of O2 consumed-to-CO2 produced nor did it impact the shape of the oxygen consumption curves during respirometry. Shorter term (12 h) batch tests showed that both chemical oxygen demand (COD) and ammonia removal were not negatively impacted by the presence of 0.1-3 mg/L malathion. Longer term continuous addition (i.e. 40 days) of 0.1 mg/L of malathion also had no effect on COD and ammonia removal. In contrast to shorter term exposures, longer term continuous addition of 3 mg/L of malathion negatively impacted both COD and nitrogen removal and was associated with shifts in the abundance of species that are common to activated sludge. These results illustrate the impact that chemicals like malathion may have on COD removal, and nitrification, as well as the robustness of activated sludge microbial communities. Published by Elsevier Ltd.

Diaqua­bis[1-hydroxy-2-(imidazol-3-ium-1-yl)-1,1′-ethyl­idenediphophonato-κ2 O,O′]zinc(II)

PubMed Central

Freire, Eleonora; Vega, Daniel R.

2009-01-01

In the title complex, [Zn(C5H9NO7P2)2(H2O)2], the zinc atom is coordinated by two bidentate zoledronate [zoledronate = (2-(1-imidazole)-1-hydr­oxy-1,1′-ethyl­idenediphophonate)] ligands and two water mol­ecules. The coordination number is 6. There is one half-mol­ecule in the asymmetric unit with the zinc atom located on a crystallographic inversion centre. The anion exists as a zwitterion with an overall charge of −1; the protonated nitro­gen in the ring has a positive charge and the two phospho­nates groups each have a single negative charge. There are two intra­molecular O—H⋯O hydrogen bonds. The mol­ecules are linked into a chain by inter­molecular O—H⋯O hydrogen bonds. Adjacent chains are further linked by O—H⋯O hydrogen bonds involving the aqua ligands. An N—H⋯O inter­action is also observed. PMID:21578164

All-Weather Hydrogen Peroxide-Based Decontamination of CBRN Contaminants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, George W.; Procell, Lawrence R.; Sorrick, David C.

2010-03-11

A hydrogen peroxide-based decontaminant, Decon Green, is efficacious for the decontamination of chemical agents VX (S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate), GD (Soman, pinacolyl methylphosphonofluoridate), and HD (mustard, bis(2-chloroethyl) sulfide); the biological agent anthrax (Bacillus anthracis); and radiological isotopes Cs-137 and Co-60; thus demonstrating the ability of this decontamination approach to ameliorate the aftermath of all three types of weapons of mass destruction (WMD). Reaction mechanisms afforded for the chemical agents are discussed as are rationales for the enhanced removal efficacy of recalcitrant 60Co on certain surfaces. Decontaminants of this nature can be deployed, and are effective, at very low temperatures (-32 °C),more » as shown for studies done with VX and HD simulants, without the need for external heat sources. Finally, the efficacy of a lower-logistics, dry decontaminant powder concentrate (utilizing the solid active-oxygen compounds peracetyl borate and Peroxydone) which can be reconstituted with water in the field prior to use, is presented.« less

Reactive decontamination of absorbing thin film polymer coatings: model development and parameter determination

NASA Astrophysics Data System (ADS)

Varady, Mark; Mantooth, Brent; Pearl, Thomas; Willis, Matthew

2014-03-01

A continuum model of reactive decontamination in absorbing polymeric thin film substrates exposed to the chemical warfare agent O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (known as VX) was developed to assess the performance of various decontaminants. Experiments were performed in conjunction with an inverse analysis method to obtain the necessary model parameters. The experiments involved contaminating a substrate with a fixed VX exposure, applying a decontaminant, followed by a time-resolved, liquid phase extraction of the absorbing substrate to measure the residual contaminant by chromatography. Decontamination model parameters were uniquely determined using the Levenberg-Marquardt nonlinear least squares fitting technique to best fit the experimental time evolution of extracted mass. The model was implemented numerically in both a 2D axisymmetric finite element program and a 1D finite difference code, and it was found that the more computationally efficient 1D implementation was sufficiently accurate. The resulting decontamination model provides an accurate quantification of contaminant concentration profile in the material, which is necessary to assess exposure hazards.

1-(2-Cyano­ethyl)-2-(2-pyrid­yl)-1H,3H-benzimidazol-3-ium perchlorate

PubMed Central

Li, Yan; Tang, Xiaoliang; Chen, Jiayu; Wu, Daxiang; Liu, Weisheng

2010-01-01

The title compound, C15H13N4 +·ClO4 −, comprises a nonplanar 1-(2-cyano­ethyl)-2-(2-pyrid­yl)-1H,3H-benzimidazol-3-ium cation [dihedral angle between the imidazole and pyridine rings = 22.5 (8)°] and a perchlorate anion. The cation is formed by protonation of the N atom of the benzimidazole ring. A charged N—H⋯O hydrogen bond connects the anion and cation, and inter­molecular C—H⋯O and C—H⋯N inter­actions contribute to the crystal packing. PMID:21579831

Reactions of NO 3 with the man-made emissions 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene, ethyl vinyl ether, and the stress-induced plant emission ethyl vinyl ketone

NASA Astrophysics Data System (ADS)

Pfrang, Christian; Tooze, Christopher; Nalty, Andrew; Canosa-Mas, Carlos E.; Wayne, Richard P.

Rate coefficients for reactions of nitrate radicals (NO 3) with the anthropogenic emissions 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene, ethyl vinyl ether, and the stress-induced plant emission ethyl vinyl ketone (pent-1-en-3-one) were determined to be (9.3±1.1)×10 -12, (9.3±3.2)×10 -12, (1.7±1.3)×10 -12 and (9.4±2.7)×10 -17 cm 3 molecule -1 s -1. We performed kinetic experiments at room temperature and atmospheric pressure using a relative-rate technique with GC-FID analysis. Experiments with ethyl vinyl ether required a modification of our established procedure that might introduce additional uncertainties, and the errors suggested reflect these difficulties. Rate coefficients are discussed in terms of electronic and steric influences. Atmospheric lifetimes with respect to important oxidants in the troposphere were calculated. NO 3-initiated oxidation is found to be the strongly dominating degradation route for 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene and ethyl vinyl ether. Atmospheric concentrations of the alkenes and their relative contribution to the total NMHC emissions from trucks can be expected to increase if plans for the introduction of particle filters for diesel engines are implemented on a global scale. Thus more kinetic data are required to better evaluate the impact of these emissions.

Chloridobis(ethyl­enediamine-κ2 N,N′)(n-pentyl­amine-κN)cobalt(III) dichloride monhydrate

PubMed Central

Anbalagan, K.; Tamilselvan, M.; Nirmala, S.; Sudha, L.

2009-01-01

The title complex, [CoCl(C5H13N)(C2H8N2)2]Cl2·H2O, comprises one chloridobis(ethyl­enediamine)(n-pentyl­amine)cobalt(III) cation, two chloride counter-anions and a water mol­ecule. The CoIII atom of the complex is hexa­coordinated by five N and one Cl atoms. The five N atoms are from two chelating ethyl­enediamine and one n-pentyl­amine ligands. Neighbouring cations and anions are connected by N—H⋯Cl and N—H⋯O hydrogen bonds to each other and also to the water mol­ecule. PMID:21582753

Electrochemical Partial Reforming of Ethanol into Ethyl Acetate Using Ultrathin Co3O4 Nanosheets as a Highly Selective Anode Catalyst

PubMed Central

2016-01-01

Electrochemical partial reforming of organics provides an alternative strategy to produce valuable organic compounds while generating H2 under mild conditions. In this work, highly selective electrochemical reforming of ethanol into ethyl acetate is successfully achieved by using ultrathin Co3O4 nanosheets with exposed (111) facets as an anode catalyst. Those nanosheets were synthesized by a one-pot, templateless hydrothermal method with the use of ammonia. NH3 was demonstrated critical to the overall formation of ultrathin Co3O4 nanosheets. With abundant active sites on Co3O4 (111), the as-synthesized ultrathin Co3O4 nanosheets exhibited enhanced electrocatalytic activities toward water and ethanol oxidations in alkaline media. More importantly, over the Co3O4 nanosheets, the electrooxidation from ethanol to ethyl acetate was so selective that no other oxidation products were yielded. With such a high selectivity, an electrolyzer cell using Co3O4 nanosheets as the anode electrocatalyst and Ni–Mo nanopowders as the cathode electrocatalyst has been successfully built for ethanol reforming. The electrolyzer cell was readily driven by a 1.5 V battery to achieve the effective production of both H2 and ethyl acetate. After the bulk electrolysis, about 95% of ethanol was electrochemically reformed into ethyl acetate. This work opens up new opportunities in designing a material system for building unique devices to generate both hydrogen and high-value organics at room temperature by utilizing electric energy from renewable sources. PMID:27610415

Electrochemical Partial Reforming of Ethanol into Ethyl Acetate Using Ultrathin Co3O4 Nanosheets as a Highly Selective Anode Catalyst.

PubMed

Dai, Lei; Qin, Qing; Zhao, Xiaojing; Xu, Chaofa; Hu, Chengyi; Mo, Shiguang; Wang, Yu Olivia; Lin, Shuichao; Tang, Zichao; Zheng, Nanfeng

2016-08-24

Electrochemical partial reforming of organics provides an alternative strategy to produce valuable organic compounds while generating H2 under mild conditions. In this work, highly selective electrochemical reforming of ethanol into ethyl acetate is successfully achieved by using ultrathin Co3O4 nanosheets with exposed (111) facets as an anode catalyst. Those nanosheets were synthesized by a one-pot, templateless hydrothermal method with the use of ammonia. NH3 was demonstrated critical to the overall formation of ultrathin Co3O4 nanosheets. With abundant active sites on Co3O4 (111), the as-synthesized ultrathin Co3O4 nanosheets exhibited enhanced electrocatalytic activities toward water and ethanol oxidations in alkaline media. More importantly, over the Co3O4 nanosheets, the electrooxidation from ethanol to ethyl acetate was so selective that no other oxidation products were yielded. With such a high selectivity, an electrolyzer cell using Co3O4 nanosheets as the anode electrocatalyst and Ni-Mo nanopowders as the cathode electrocatalyst has been successfully built for ethanol reforming. The electrolyzer cell was readily driven by a 1.5 V battery to achieve the effective production of both H2 and ethyl acetate. After the bulk electrolysis, about 95% of ethanol was electrochemically reformed into ethyl acetate. This work opens up new opportunities in designing a material system for building unique devices to generate both hydrogen and high-value organics at room temperature by utilizing electric energy from renewable sources.

Benzoylated ethyl 1-thioglycosides: direct preparation from per-O-benzoylated sugars.

PubMed

Sail, Deepak; Kováč, Pavol

2012-08-01

D-Glucose, lactose, maltose, and melibiose were benzoylated with Bz(2)O-Et(3)N reagent to give fully benzoylated β products. Under the same conditions, D-mannose produced a mixture where the β-benzoate predominated. Treatment of the foregoing compounds with EtSH at slightly elevated temperature (50-60°C) in the presence of BF(3)·Et(2)O as a promoter gave the corresponding ethyl 1-thio glycosides in high yields. The α-products predominated in all cases in the anomeric mixtures formed. Individual products of all reactions were isolated by chromatography, they were obtained in analytically pure state, and were fully characterized by (1)H and (13)C NMR data and physical constants. Published by Elsevier Ltd.

Palladium(II) complexes with R(2)edda derived ligands. Part IV. O,O'-dialkyl esters of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride and their palladium(II) complexes: synthesis, characterization and in vitro antitumoral activity against chronic lymphocytic leukemia (CLL) cells.

PubMed

Vujić, Jelena M; Cvijović, Milica; Kaluderović, Goran N; Milovanović, Marija; Zmejkovski, Bojana B; Volarević, Vladislav; Arsenijević, Nebojsa; Sabo, Tibor J; Trifunović, Srećko R

2010-09-01

Four novel bidentate N,N'-ligand precursors, including O,O'-dialkyl esters (alkyl = ethyl, n-propyl, n-butyl and n-pentyl), L1 x 2 HCl-L4 x 2 HCl, of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride [(S,S)-H(4)eddl]Cl(2) and the corresponding palladium(II) complexes 1-4, were prepared and characterized by IR, (1)H NMR and (13)C NMR spectroscopy and elemental analysis. In vitro cytotoxicity of all compounds was determined against chronic lymphocytic leukemia cells (CLL). The compounds were found to exhibit higher antitumoral activity than cisplatin. The most active compound 2, [PdCl(2){(S,S)-nPr(2)eddl}], was found to be 13.6 times more active than cisplatin on CLL cells. 2010 Elsevier Masson SAS. All rights reserved.

2,2′-Bi(9,9-di­ethyl­fluorene)

PubMed Central

Park, Ki-Min; Oh, Hankook; Kang, Youngjin

2014-01-01

The title compound, C34H34, systematic name 9,9,9′,9′-tetra­ethyl-2,2′-bi(9H-fluorene), crystallized with two crystallographically independent mol­ecules (A and B) in the asymmetric unit. These differ mainly in the orientation of the lateral ethyl chains: in mol­ecule A, they are both on the same side of the mol­ecule whereas in mol­ecule B, one di­ethyl­fluorene moiety has undergone a 180° rotation such that the two pairs of ethyl residues appear on opposite sides of the mol­ecule. The fluorene ring systems subtend dihedral angles of 31.37 (4) and 43.18 (3)° in mol­ecules A and B, respectively. Hence the two fluorene moieties are tilted slightly toward one another. This may be due to the presence of inter­molecular C—H⋯π inter­actions between neighboring mol­ecules. The lateral ethyl chains (excluding H atoms) are also almost planar, with each pair almost perpendicular to the plane of the fluorene system to which they are attached with dihedral angles between the ethyl and fluorene planes in the range 86.04 (8)–89.5 (1)°. PMID:24764898

Continuous hydrogenation of ethyl levulinate to γ-valerolactone and 2-methyl tetrahydrofuran over alumina doped Cu/SiO2 catalyst: the potential of commercialization

NASA Astrophysics Data System (ADS)

Zheng, Junlin; Zhu, Junhua; Xu, Xuan; Wang, Wanmin; Li, Jiwen; Zhao, Yan; Tang, Kangjian; Song, Qi; Qi, Xiaolan; Kong, Dejin; Tang, Yi

2016-07-01

Hydrogenation of levulinic acid (LA) and its esters to produce γ-valerolactone (GVL) and 2-methyl tetrahydrofuran (2-MTHF) is a key step for the utilization of cellulose derived LA. Aiming to develop a commercially feasible base metal catalyst for the production of GVL from LA, with satisfactory activity, selectivity, and stability, Al2O3 doped Cu/SiO2 and Cu/SiO2 catalysts were fabricated by co-precipitation routes in parallel. The diverse physio-chemical properties of these two catalysts were characterized by XRD, TEM, dissociative N2O chemisorptions, and Py-IR methods. The catalytic properties of these two catalysts were systematically assessed in the continuous hydrogenation of ethyl levulinate (EL) in a fixed-bed reactor. The effect of acidic property of the SiO2 substrate on the catalytic properties was investigated. To justify the potential of its commercialization, significant attention was paid on the initial activity, proper operation window, by-products control, selectivity, and stability of the catalyst. The effect of reaction conditions, such as temperature and pressure, on the performance of the catalyst was also thoroughly studied. The development of alumina doped Cu/SiO2 catalyst strengthened the value-chain from cellulose to industrially important chemicals via LA and GVL.

Continuous hydrogenation of ethyl levulinate to γ-valerolactone and 2-methyl tetrahydrofuran over alumina doped Cu/SiO2 catalyst: the potential of commercialization

PubMed Central

Zheng, Junlin; Zhu, Junhua; Xu, Xuan; Wang, Wanmin; Li, Jiwen; Zhao, Yan; Tang, Kangjian; Song, Qi; Qi, Xiaolan; Kong, Dejin; Tang, Yi

2016-01-01

Hydrogenation of levulinic acid (LA) and its esters to produce γ-valerolactone (GVL) and 2-methyl tetrahydrofuran (2-MTHF) is a key step for the utilization of cellulose derived LA. Aiming to develop a commercially feasible base metal catalyst for the production of GVL from LA, with satisfactory activity, selectivity, and stability, Al2O3 doped Cu/SiO2 and Cu/SiO2 catalysts were fabricated by co-precipitation routes in parallel. The diverse physio-chemical properties of these two catalysts were characterized by XRD, TEM, dissociative N2O chemisorptions, and Py-IR methods. The catalytic properties of these two catalysts were systematically assessed in the continuous hydrogenation of ethyl levulinate (EL) in a fixed-bed reactor. The effect of acidic property of the SiO2 substrate on the catalytic properties was investigated. To justify the potential of its commercialization, significant attention was paid on the initial activity, proper operation window, by-products control, selectivity, and stability of the catalyst. The effect of reaction conditions, such as temperature and pressure, on the performance of the catalyst was also thoroughly studied. The development of alumina doped Cu/SiO2 catalyst strengthened the value-chain from cellulose to industrially important chemicals via LA and GVL. PMID:27377401

31P-edited diffusion-ordered 1H NMR spectroscopy for the spectral isolation and identification of organophosphorus compounds related to chemical weapons agents and their degradation products.

PubMed

Mayer, Brian P; Valdez, Carlos A; Hok, Saphon; Chinn, Sarah C; Hart, Bradley R

2012-12-04

Organophosphorus compounds represent a large class of molecules that include pesticides, flame-retardants, biologically relevant molecules, and chemical weapons agents (CWAs). The detection and identification of organophosphorus molecules, particularly in the cases of pesticides and CWAs, are paramount to the verification of international treaties by various organizations. To that end, novel analytical methodologies that can provide additional support to traditional analyses are important for unambiguous identification of these compounds. We have developed an NMR method that selectively edits for organophosphorus compounds via (31)P-(1)H heteronuclear single quantum correlation (HSQC) and provides an additional chromatographic-like separation based on self-diffusivities of the individual species via (1)H diffusion-ordered spectroscopy (DOSY): (1)H-(31)P HSQC-DOSY. The technique is first validated using the CWA VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) by traditional two-dimensional DOSY spectra. We then extend this technique to a complex mixture of VX degradation products and identify all the main phosphorus-containing byproducts generated after exposure to a zinc-cyclen organometallic homogeneous catalyst.

Continuum Model for Decontamination of Chemical Warfare Agent from a Rubbery Polymer using the Maxwell-Stefan Formulation

NASA Astrophysics Data System (ADS)

Varady, Mark; Bringuier, Stefan; Pearl, Thomas; Stevenson, Shawn; Mantooth, Brent

Decontamination of polymers exposed to chemical warfare agents (CWA) often proceeds by application of a liquid solution. Absorption of some decontaminant components proceed concurrently with extraction of the CWA, resulting in multicomponent diffusion in the polymer. In this work, the Maxwell-Stefan equations were used with the Flory-Huggins model of species activity to mathematically describe the transport of two species within a polymer. This model was used to predict the extraction of the nerve agent O-ethyl S-[2(diisopropylamino)ethyl] methylphosphonothioate (VX) from a silicone elastomer into both water and methanol. Comparisons with experimental results show good agreement with minimal fitting of model parameters from pure component uptake data. Reaction of the extracted VX with sodium hydroxide in the liquid-phase was also modeled and used to predict the overall rate of destruction of VX. Although the reaction proceeds more slowly in the methanol-based solution compared to the aqueous solution, the extraction rate is faster due to increasing VX mobility as methanol absorbs into the silicone, resulting in an overall faster rate of VX destruction.

Preparation of Fe 3O 4/poly(styrene-butyl acrylate-[2-(methacryloxy)ethyl]trimethylammonium chloride) by emulsifier-free emulsion polymerization and its interaction with DNA

NASA Astrophysics Data System (ADS)

Li, Xiaolong; Liu, Guoqiang; Yan, Wei; Chu, Paul K.; Yeung, Kelvin W. K.; Wu, Shuilin; Yi, Changfeng; Xu, Zushun

2012-04-01

Cationic magnetic polymer particles Fe3O4/poly(styrene-butyl acrylate-[2-(methacryloxy)ethyl]trimethylammonium chloride), a type of potential gene carrier, were prepared by emulsifier-free emulsion polymerization with oleic acid modified magnetite Fe3O4, styrene, butyl acrylate and [2-(methacryloxy)ethyl]trimethylammonium chloride) (METAC). The morphology of the particles was characterized by transmission electron microscopy and the composites of particles were characterized by FT-IR spectroscopy, X-ray diffraction. These results showed that magnetic particles were well dispersed in polymers with the content of about 15%(wt/wt). The composites exhibited superparamagnetism and possessed a certain level of magnetic response. The interactions between the particles with calf-thymus DNA (ct DNA) were confirmed by zeta potential measurement, UV-vis spectroscopy and fluorescence spectroscopy. The DNA-binding capacity determined by the agarose gel electrophoresis showed good binding capacity of the emulsion to DNA. These results suggested the potential of the cationic magnetic polymer emulsion as gene target delivery carrier.

Detection of interstellar ethyl cyanide

NASA Technical Reports Server (NTRS)

Johnson, D. R.; Lovas, F. J.; Gottlieb, C. A.; Gottlieb, E. W.; Litvak, M. M.; Thaddeus, P.; Guelin, M.

1977-01-01

Twenty-four millimeter-wave emission lines of ethyl cyanide (CH3CH2CN) have been detected in the Orion Nebula (OMC-1) and seven in Sgr B2. To derive precise radial velocities from the astronomical data, a laboratory measurement of the rotational spectrum of ethyl cyanide has been made at frequencies above 41 GHz. In OMC-1, the rotational temperature of ethyl cyanide is 90 K (in good agreement with other molecules), the local-standard-of-rest radial velocity is 4.5 + or - 1.0 km/s (versus 8.5 km/s for most molecules), and the column density is 1.8 by 10 to the 14th power per sq cm (a surprisingly high figure for a complicated molecule). The high abundance of ethyl cyanide in the Orion Nebula suggests that ethane and perhaps larger saturated hydrocarbons may be common constituents of molecular clouds and have escaped detection only because they are nonpolar or only weakly polar.

Experimental and theoretical study of pure and doped crystals: Gd2O2S, Gd2O2S:Eu3+ and Gd2O2S:Tb3+

NASA Astrophysics Data System (ADS)

Wang, Fei; Chen, Xiumin; Liu, Dachun; Yang, Bin; Dai, Yongnian

2012-08-01

Quantum chemistry and experimental method were used to study on pure and doped Gd2O2S crystals in this paper. The band structure and DOS diagrams of pure and doped Gd2O2S crystals which calculated by using DFT (Density Functional Theory) method were illustrated to explain the luminescent properties of impurities in crystals. The calculations of the crystal structure were finished by using the program of CASTEP (Cambridge Sequential Total Energy Package). The samples showed the characteristic emissions of Tb3+ ions with 5D4-7FJ transitions and Eu3+ ions with 5D0-7FJ transitions which emit pure green luminescence and red luminescence respectively. The experimental excitation spectra of Tb3+ and Eu3+ doped Gd2O2S are in agreement of the DOS diagrams over the explored energy range, which has allowed a better understanding of different luminescence mechanisms of Tb3+ and Eu3+ in Gd2O2S crystals.

Polysaccharide-thickened aqueous fluoride solutions for rapid destruction of the nerve agent VX. Introducing the opportunity for extensive decontamination scenarios.

PubMed

Elias, Shlomi; Saphier, Sigal; Columbus, Ishay; Zafrani, Yossi

2014-01-01

Among the chemical warfare agents, the extremely toxic nerve agent VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate) is a target of high importance in the development of decontamination methods, due to its indefinite persistence on common environmental surfaces. Liquid decontaminants are mostly characterized by high corrosivity, usually offer poor coverage, and tend to flow and accumulate in low areas. Therefore, the development of a noncorrosive decontaminant, sufficiently viscous to resist dripping from the contaminated surface, is necessary. In the present paper we studied different polysaccharides-thickened fluoride aqueous solutions as noncorrosive decontaminants for rapid and efficient VX degradation to the nontoxic product EMPA (ethyl methylphosphonic acid). Polysaccharides are environmentally benign, natural, and inexpensive. Other known decontaminants cannot be thickened by polysaccharides, due to the sensitivity of the latter toward basic or oxidizing agents. We found that the efficiency of VX degradation in these viscous solutions in terms of kinetics and product identity is similar to that of KF aqueous solutions. Guar gum (1.5 wt %) with 4 wt % KF was chosen for further evaluation. The benign nature, rheological properties, adhering capabilities to different surfaces, and decontamination from a porous matrix were examined. This formulation showed promising properties for implementation as a spray decontaminant for common and sensitive environmental surfaces.

Colonization on Cucumber Root and Enhancement of Chlorimuron-ethyl Degradation in the Rhizosphere by Hansschlegelia zhihuaiae S113 and Root Exudates.

PubMed

Zhang, Hao; Chen, Feng; Zhao, Hua-Zhu; Lu, Jia-Sen; Zhao, Meng-Jun; Hong, Qing; Huang, Xing

2018-05-09

The colonization of Hansschlegelia zhihuaiae S113 and its degradation of the herbicide chlorimuron-ethyl in the cucumber rhizosphere was investigated. The results reveal that S113 colonized the cucumber roots (2.14 × 10 5 cells per gram of roots) and were able to survive in the rhizosphere (maintained for 20 d). The root exudates promoted colonization on roots and increased the degradation of chlorimuron-ethyl by S113. Five organic acids in cucumber-root exudates were detected and identified by HPLC. Citric acid and fumaric acid significantly stimulated S113 colonization on cucumber roots, with 18.4 and 15.5% increases, respectively, compared with the control. After irrigation with an S113 solution for 10 days, chlorimuron-ethyl could not be detected in the roots, seedlings, or rhizosphere soil, which allowed for improved cucumber growth. Therefore, the degradation mechanism of chlorimuron-ethyl residues by S113 in the rhizosphere could be applied in situ for the bioremediation of chlorimuron-ethyl contaminated soil to ensure crop safety.

Solid state reactions of CeO 2, PuO 2, (U,Ce)O 2 and (U,Pu)O 2 with K 2S 2O 8

NASA Astrophysics Data System (ADS)

Keskar, Meera; Kasar, U. M.; Mudher, K. D. Singh; Venugopal, V.

2004-09-01

Solid state reactions of CeO 2, PuO 2 and mixed oxides (U,Ce)O 2 and (U,Pu)O 2 containing different mol.% of Ce and Pu, were carried out with K 2S 2O 8 at different temperatures to identify the formation of various products and to investigate their dissolution behaviour. X-ray, chemical and thermal analysis methods were used to characterise the products formed at various temperatures. The products obtained by heating two moles of K 2S 2O 8 with one mole each of CeO 2, PuO 2, (U,Ce)O 2 and (U,Pu)O 2 at 400 °C were identified as K 4Ce(SO 4) 4, K 4Pu(SO 4) 4, K 4(U,Ce)(SO 4) 4 and K 4(U,Pu)(SO 4) 4, respectively. K 4Ce(SO 4) 4 further decomposed to form K 4Ce(SO 4) 3.5 at 600 °C and mixture of K 2SO 4 and CeO 2 at 950 °C. Thus the products formed during the reaction of 2K 2S 2O 8 + CeO 2 show that cerium undergoes changes in oxidation state from +4 to +3 and again to +4. XRD data of K 4Ce(SO 4) 4 and K 4Ce(SO 4) 3.5 were indexed on triclinic and monoclinic system, respectively. PuO 2 + 2K 2S 2O 8 reacts at 400 °C to form K 4Pu(SO 4) 4 which was stable upto 750 °C and further decomposes to form K 2SO 4 + PuO 2 at 1000 °C. The products formed at 400 °C during the reactions of the oxides and mixed oxides were found to be readily soluble in 1-2 M HNO 3.

VX fate on common matrices: evaporation versus degradation.

PubMed

Columbus, Ishay; Waysbort, Daniel; Marcovitch, Itzhak; Yehezkel, Lea; Mizrahi, Dana M

2012-04-03

A study of the volatilization rate of the nerve agent VX (O-ethyl S-2-(N,N-diisopropylamino)ethyl methylphosphonothiolate) from various urban matrices in a specially designed climatic chamber (model system) is described. The performance of the model system combined with the analytical procedure produced profiles of vapor concentration obtained from samples of VX dispersed as small droplets on the surfaces of the matrices. The results indicated that the bitumen-containing surfaces such as asphalt blocks and bitumen sheets conserve VX and slow-release part of it over a long period of time. No complete mass balance could be obtained for these surfaces. Influence of environmental and experimental parameters as well as the efficacy of decontamination procedure were also measured. From smooth surface tiles a fast release of VX was measured and almost a complete mass balance was obtained, which characterizes the behavior of inert surfaces. Experiments carried out on concrete blocks showed fast decay of the concentration profile along with a very poor reconstruction of the initial quantity of VX, implying that this matrix degraded VX actively due to its multiple basic catalytic sites. To complement this study, solid-state NMR measurements were compared to add data concerning agent-fate within the matrices.

Microwave spectroscopy and curious molecular dynamics of ethyl trifluoroacetate

NASA Astrophysics Data System (ADS)

Bohn, Robert K.; Montgomery, John A.; Harvey Michels, H.; Acharte, Christian

2017-05-01

The first ethyl ester whose structure was determined by microwave spectroscopy is ethyl formate. It exists in two conformations. In the 1970s, that study was used as a model to determine the structures of other ethyl esters, ethyl cyanoformate, chloroformate, and trifluoroacetate. They display the same conformations as ethyl formate. But under the experimental conditions used, Stark modulation with a maximum electric field, static low pressure gas, rapid sweeping, and long detector time constants, each of those esters displays bands of an additional third species. A careful, high resolution study of ethyl cyanoformate only observed two conformers. A model has been proposed that the third species derives from a dense array of torsionally excited states with broadened transitions due to short lifetimes. The present study of ethyl trifluoroacetate in a pulsed jet Fourier Transform spectrometer is intended to clarify the earlier results. Two conformers are observed including all their monosubstituted 13C and 18O isotopologs. In a pulsed jet Fourier Transform spectrometer using argon as the carrier gas, only one conformer is observed. Switching to helium as the carrier gas, another, higher energy conformer is also observed.

Comparing the Thermodynamic Behaviour of Al(1)+ZrO2(s) to Al(1)+Al2O3(s)

NASA Technical Reports Server (NTRS)

Copland, Evan

2004-01-01

In an effort to better determine the thermodynamic properties of Al(g) and Al2O(g). the vapor in equilibrium with Al(l)+ZrO2(s) was compared to the vapor in equilibrium with Al(l)+Al2O3(s) over temperature range 1197-to-1509K. The comparison was made directly by Knudsen effusion-cell mass spectrometry with an instrument configured for a multiple effusion-cell vapor source (multi-cell KEMS). Second law enthalpies of vaporization of Al(g) and Al2O(g) together with activity measurements show that Al(l)+ZrO2(s) is thermodynamically equivalent to Al(l)+Al2O3(s), indicating Al(l) remained pure and Al2O3(s) was present in the ZrO2-cell. Subsequent observation of the Al(l)/ZrO2 and vapor/ZrO2 interfaces revealed a thin Al2O3-layer had formed, separating the ZrO2-cell from Al(l) and Al(g)+Al2O(g), effectively transforming it into an Al2O3 effusion-cell. This behavior agrees with recent observations made for Beta-NiAl(Pt) alloys measured in ZrO2 effusion-cell.

Dissociative photoionization of ethyl acrylate: Theoretical and experimental insights

NASA Astrophysics Data System (ADS)

Song, Yanlin; Chen, Jun; Ding, Mengmeng; Wei, Bin; Cao, Maoqi; Shan, Xiaobin; Zhao, Yujie; Huang, Chaoqun; Sheng, Liusi; Liu, Fuyi

2015-08-01

The photoionization and dissociation of ethyl acrylate have been investigated by time-of-flight mass spectrometer with tunable vacuum ultraviolet (VUV) source in the range of 9.0-20.0 eV. The photoionization mass spectrum (PIMS) for ethyl acrylate and photoionization efficiency (PIE) curves for its major fragment ions: C5H7O2+, C4H5O2+, C3H5O2+, C3H4O+, C3H3O+, C2H5O+, C2H3O+, C2H5+ and C2H4+ have been obtained. The formation channels of main fragments are predicted by Gaussian 09 program at G3B3 level and examined via their dissociation energies from experimental results. Based on our analysis, nine main dissociative photoionization channels are proposed: C5H7O2+ + H, C4H5O2+ + CH3, C3H5O2+ + C2H3, C3H4O+ + C2H4O, C3H3O+ + C2H5O, C2H5O+ + C3H3O, C2H3O+ + C3H5O, C2H5+ + C3H3O2, C2H4+ + C3H4O2, respectively. The results of this work lead to a better understanding of photochemistry in the environment.

Photoelectrochemical Properties of CuS-GeO2-TiO2 Composite Coating Electrode

PubMed Central

Wen, Xinyu; Zhang, Huawei

2016-01-01

The ITO (indium tin oxide) conductive glass-matrix CuS-GeO2-TiO2 composite coating was generated via EPD (electrophoretic deposition) and followed by a sintering treatment at 450°C for 40 minutes. Characterizations of the CuS-GeO2-TiO2 composite coating were taken by SEM (scanning electron microscope), XRD (X-ray diffraction), EDX (energy dispersive X-ray), UV-Vis DRS (ultraviolet-visible diffuse reflection spectrum), and FT-IR (Fourier transform infrared spectroscopy). Results showed that CuS and GeO2 had dispersed in this CuS-GeO2-TiO2 composite coating (mass percentages for CuS and GeO2 were 1.23% and 2.79%, respectively). The electrochemical studies (cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Tafel polarization) of this CuS-GeO2-TiO2 composite coating electrode were performed in pH = 9.51 Na2CO3-NaHCO3 buffer solution containing 0.50 mol/L CH3OH under the conditions of visible light, ultraviolet light (λ = 365 nm), and dark (without light irradiation as control), respectively. Electrochemical studies indicated that this CuS-GeO2-TiO2 composite coating electrode had better photoelectrocatalytic activity than the pure TiO2 electrode in the electrocatalysis of methanol under visible light. PMID:27055277

Photoelectrochemical Properties of CuS-GeO2-TiO2 Composite Coating Electrode.

PubMed

Wen, Xinyu; Zhang, Huawei

2016-01-01

The ITO (indium tin oxide) conductive glass-matrix CuS-GeO2-TiO2 composite coating was generated via EPD (electrophoretic deposition) and followed by a sintering treatment at 450°C for 40 minutes. Characterizations of the CuS-GeO2-TiO2 composite coating were taken by SEM (scanning electron microscope), XRD (X-ray diffraction), EDX (energy dispersive X-ray), UV-Vis DRS (ultraviolet-visible diffuse reflection spectrum), and FT-IR (Fourier transform infrared spectroscopy). Results showed that CuS and GeO2 had dispersed in this CuS-GeO2-TiO2 composite coating (mass percentages for CuS and GeO2 were 1.23% and 2.79%, respectively). The electrochemical studies (cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Tafel polarization) of this CuS-GeO2-TiO2 composite coating electrode were performed in pH = 9.51 Na2CO3-NaHCO3 buffer solution containing 0.50 mol/L CH3OH under the conditions of visible light, ultraviolet light (λ = 365 nm), and dark (without light irradiation as control), respectively. Electrochemical studies indicated that this CuS-GeO2-TiO2 composite coating electrode had better photoelectrocatalytic activity than the pure TiO2 electrode in the electrocatalysis of methanol under visible light.

Simultaneous quantification of VX and its toxic metabolite in blood and plasma samples and its application for in vivo and in vitro toxicological studies.

PubMed

Reiter, Georg; Mikler, John; Hill, Ira; Weatherby, Kendal; Thiermann, Horst; Worek, Franz

2011-09-15

The present study was initiated to develop a sensitive and highly selective method for the simultaneous quantification of the nerve agent VX (O-ethyl S-[2(diisopropylamino)ethyl] methylphosphonothioate) and its toxic metabolite (EA-2192) in blood and plasma samples in vivo and in vitro. For the quantitative detection of VX and EA-2192 the resolution was realized on a HYPERCARB HPLC phase. A specific procedure was developed to isolate both toxic analytes from blood and plasma samples. The limit of detection was 0.1 pg/ml and the absolute recovery of the overall sample preparation procedure was 74% for VX and 69% for EA-2192. After intravenous and percutaneous administration of a supralethal doses of VX in anaesthetised swine both VX and EA-2192 could be quantified over 540 min following exposure. This study is the first to verify the in vivo formation of the toxic metabolite EA-2192 after poisoning with the nerve agent VX. Further toxicokinetic and therapeutic studies are required in order to determine the impact of EA-2192 on the treatment of acute VX poisoning. Copyright © 2011 Elsevier B.V. All rights reserved.

Benzoylated ethyl 1-thioglycosides: direct preparation from per-O-benzoylated sugars

PubMed Central

Sail, Deepak; Kováč, Pavol

2012-01-01

D-Glucose, lactose, maltose, and melibiose were benzoylated with Bz2O–Et3N reagent to give fully benzoylated β products. Under the same conditions, D-mannose produced a mixture where the β-benzoate predominated. Treatment of the foregoing compounds with EtSH at slightly elevated temperature (50– 60 °C) in the presence of BF3·Et2O as a promoter gave the corresponding ethyl 1-thio glycosides in high yields. The α-products predominated in all cases in the anomeric mixtures formed. Individual products of all reactions were isolated by chromatography, they were obtained in analytically pure state, and were fully characterized by 1H and 13C NMR data and physical constants. PMID:22739243

Crystal structure of the tri-ethyl-ammonium salt of 3-[(4-hy-droxy-3-meth-oxy-phen-yl)(4-hy-droxy-2-oxo-2H-chromen-3-yl)meth-yl]-2-oxo-2H-chromen-4-olate.

PubMed

Ikram, Muhammad; Rehman, Sadia; Khan, Afzal; Schulzke, Carola

2018-03-01

The reaction between 3,3'-[(3-meth-oxy-4-hy-droxy-phen-yl)methanedi-yl]bis-(4-hy-droxy-2 H -chromen-2-one) and tri-ethyl-amine in methanol yielded the title compound tri-ethyl-ammonium 3-[(4-hy-droxy-3-meth-oxy-phen-yl)(4-hy-droxy-2-oxo-2 H -chromen-3-yl)meth-yl]-2-oxo-2 H -chromen-4-olate, C 6 H 16 N + ·C 26 H 17 O 8 - or (NHEt 3 ) + (C 26 H 17 O 8 ) - , which crystallized directly from its methano-lic mother liquor. The non-deprotonated coumarol substituent shares its H atom with the deprotonated coumarolate substituent in a short negative charge-assisted hydrogen bond in which the freely refined H atom is moved from its parent O atom towards the acceptor O atom, elongating the covalent O-H bond to 1.18 (3) Å. The respective H atom can therefore be described as being shared by two alcohol O atoms, culminating in the formation of an eight-membered ring.

Oxidation of atomically thin MoS2 on SiO2

NASA Astrophysics Data System (ADS)

Yamamoto, Mahito; Cullen, William; Einstein, Theodore; Fuhrer, Michael

2013-03-01

Surface oxidation of MoS2 markedly affects its electronic, optical, and tribological properties. However, oxidative reactivity of atomically thin MoS2 has yet to be addressed. Here, we investigate oxidation of atomic layers of MoS2 using atomic force microscopy and Raman spectroscopy. MoS2 is mechanically exfoliated onto SiO2 and oxidized in Ar/O2 or Ar/O3 (ozone) at 100-450 °C. MoS2 is much more reactive to O2 than an analogous atomic membrane of graphene and monolayer MoS2 is completely etched very rapidly upon O2 treatment above 300 °C. Thicker MoS2 (> 15 nm) transforms into MoO3 after oxidation at 400 °C, which is confirmed by a Raman peak at 820 cm-1. However, few-layer MoS2 oxidized below 400 °C exhibits no MoO3 Raman mode but etch pits are formed, similar to graphene. We find atomic layers of MoS2 shows larger reactivity to O3 than to O2 and monolayer MoS2 transforms chemically upon O3 treatment even below 100 °C. Work supported by the U. of Maryland NSF-MRSEC under Grant No. DMR 05-20741.

Determining the partial photoionization cross-sections of ethyl radicals.

PubMed

FitzPatrick, B L; Maienschein-Cline, M; Butler, L J; Lee, S-H; Lin, J J

2007-12-13

Using a crossed laser-molecular beam scattering apparatus, these experiments photodissociate ethyl chloride at 193 nm and detect the Cl and ethyl products, resolved by their center-of-mass recoil velocities, with vacuum ultraviolet photoionization. The data determine the relative partial cross-sections for the photoionization of ethyl radicals to form C2H5+, C2H4+, and C2H3+ at 12.1 and 13.8 eV. The data also determine the internal energy distribution of the ethyl radical prior to photoionization, so we can assess the internal energy dependence of the photoionization cross-sections. The results show that the C2H4++H and C2H3++H2 dissociative photoionization cross-sections strongly depend on the photoionization energy. Calibrating the ethyl radical partial photoionization cross-sections relative to the bandwidth-averaged photoionization cross-section of Cl atoms near 13.8 eV allows us to use these data in conjunction with literature estimates of the Cl atom photoionization cross-sections to put the present bandwidth-averaged cross-sections on an absolute scale. The resulting bandwidth-averaged cross-section for the photoionization of ethyl radicals to C2H5+ near 13.8 eV is 8+/-2 Mb. Comparison of our 12.1 eV data with high-resolution ethyl radical photoionization spectra allows us to roughly put the high-resolution spectrum on the same absolute scale. Thus, one obtains the photoionization cross-section of ethyl radicals to C2H5+ from threshold to 12.1 eV. The data show that the onset of the C2H4++H dissociative photoionization channel is above 12.1 eV; this result offers a simple way to determine whether the signal observed in photoionization experiments on complex mixtures is due to ethyl radicals. We discuss an application of the results for resolving the product branching in the O+allyl bimolecular reaction.

40 CFR 721.2465 - Xanthylium, 9-(2-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate.

Code of Federal Regulations, 2013 CFR

2013-07-01

...)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. 721.2465 Section 721.2465 Protection of...-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. (a) Chemical substance and significant...-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate (PMN P-00-1195; CAS No. 26694-69-9) is...

40 CFR 721.2465 - Xanthylium, 9-(2-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate.

Code of Federal Regulations, 2012 CFR

2012-07-01

...)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. 721.2465 Section 721.2465 Protection of...-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. (a) Chemical substance and significant...-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate (PMN P-00-1195; CAS No. 26694-69-9) is...

40 CFR 721.2465 - Xanthylium, 9-(2-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate.

Code of Federal Regulations, 2011 CFR

2011-07-01

...)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. 721.2465 Section 721.2465 Protection of...-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. (a) Chemical substance and significant...-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate (PMN P-00-1195; CAS No. 26694-69-9) is...

40 CFR 721.2465 - Xanthylium, 9-(2-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate.

Code of Federal Regulations, 2014 CFR

2014-07-01

...)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. 721.2465 Section 721.2465 Protection of...-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. (a) Chemical substance and significant...-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate (PMN P-00-1195; CAS No. 26694-69-9) is...

Quantum dot sensitized solar cell based on TiO2/CdS/Ag2S heterostructure

NASA Astrophysics Data System (ADS)

Pawar, Sachin A.; Patil, Dipali S.; Kim, Jin Hyeok; Patil, Pramod S.; Shin, Jae Cheol

2017-04-01

Quantum dot sensitized solar cell (QDSSC) is fabricated based on a stepwise band structure of TiO2/CdS/Ag2S to improve the photoconversion efficiency of TiO2/CdS system by incorporating a low band gap Ag2S QDs. Vertically aligned TiO2 nanorods assembly is prepared by a simple hydrothermal technique. The formation of CdS and Ag2S QDs over TiO2 nanorods assembly as a photoanode is carried out by successive ionic layer adsorption and reaction (SILAR) technique. The synthesized electrode materials are characterized by XRD, XPS, field emission scanning electron microscopy (FE-SEM), Optical, solar cell and electrochemical performances. The results designate that the QDs of CdS and Ag2S have efficiently covered exterior surfaces of TiO2 nanorods assembly. A cautious evaluation between TiO2/CdS and TiO2/CdS/Ag2S sensitized cells tells that CdS and Ag2S synergetically helps to enhance the light harvesting ability. Under AM 1.5G illumination, the photoanodes show an improved power conversion efficiency of 1.87%, in an aqueous polysulfide electrolyte with short-circuit photocurrent density of 7.03 mA cm-2 which is four fold higher than that of a TiO2/CdS system.

The stability of N-[2-(4-o-fluorophenylpiperazin-1-yl)ethyl]-2,5-dimethyl-1 -phenylpyrrole-3,4-dicarboximide in aqueous-organic solutions.

PubMed

Zajac, Marianna; Sobczak, Agnieszka; Malinka, Wiesław; Redzicka, Aleksandra

2010-01-01

The first-order reaction of solvolysis of N-[2-(4-o-fluorophenylpiperazin-1-yl)ethyl]-2,5-dimethyl-1-phenylpyrrole-3,4-dicarboximide (PDI) was investigated as a function of pH at 333, 328, 323, 318 and 308 K in the pH range 1.11 - 12.78. The decomposition of PDI was followed by the HPLC method (Nucleosil 10-C8 column (250 x 4 mm I.D., dp = 10 microm), mobile phase: 0.018 mol/L ammonia acetate - acetonitrile (40: 60 v/v), UV detector: 240 nm, flow rate: 1 mL/min. Specific acid-base catalysis involves solvolysis of the undissociated molecules of PDI catalyzed by hydroxide ions and spontaneous solvolysis of the undissociated and monoprotonated forms of PDI under the influence of solvents. The thermodynamic parameters of the reactions--activation energy (E(a)), enthalpy (DH(#)), entropy (DS(#))--were calculated.

Direct observation of surface ethyl to ethane interconversion upon C2H4 hydrogenation over Pt/Al2O3 catalyst by time-resolved FT-IR spectroscopy.

PubMed

Wasylenko, Walter; Frei, Heinz

2005-09-08

Time-resolved FT-IR spectra of ethylene hydrogenation over alumina-supported Pt catalyst were recorded at 25 ms resolution in the temperature range of 323-473 K using various H2 concentrations (1 atm total gas pressure). Surface ethyl species (2870 and 1200 cm(-1)) were detected at all temperatures along with the gas-phase ethane product (2954 and 2893 cm(-1)). The CH3CH2Pt growth was instantaneous on the time scale of 25 ms under all experimental conditions. At 323 K, the decay time of surface ethyl (122 +/- 10 ms) coincides with the rise time of ethane (144 +/- 14 ms). This establishes direct kinetic evidence for surface ethyl as the relevant reaction intermediate. Such a direct link between the temporal behavior of an unstable surface intermediate and the final product in a heterogeneous catalytic system has not been demonstrated before. A fraction (25%) of the asymptotic ethane growth at 323 K is prompt, indicating that there are surface ethyl species that react much faster than the majority of the CH3CH2Pt intermediates. The dispersive kinetics is attributed to the varying strength of interaction of the ethyl species with the Pt surface caused by heterogeneity of the surface environment. At 473 K, the majority of ethyl intermediates are hydrogenated prior to the recording of the first time slice (24 ms), and a correspondingly large prompt growth of ethane is observed. The yield and kinetics of the surface ethylidyne are in agreement with the known spectator nature of this species.

Diethyl 2,2'-(ethane-1,2-diyldi-oxy)di-benzo-ate.

PubMed

Shi, Huaduan; Qin, Haisha; Ma, Zhen

2014-05-01

The mol-ecular title compound, C20H22O6, was obtained by the reaction of ethyl 2-hy-droxy-benzoate with 1,2-di-chloro-ethane. The mol-ecule lies on a twofold rotation axis which passes through the middle of the central ethyl-ene bridge. This group exhibits a gauche conformation with the corresponding O-C-C-O torsion angle being 73.2 (2)°. The C atoms of the carboxyl group, the aryl and the O-CH2 group are coplanar, with an r.m.s. deviation of 0.01 Å. The two aryl rings form a dihedral angle of 67.94 (4)°. The ester ethyl group is disordered over two sets of sites with an occupancy ratio of 0.59 (2):0.41 (2). The crystal packing is dominated by van der Waals forces.

40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed triesters with...

40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed triesters with...

40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed triesters with...

40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed triesters with...

40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed triesters with...

Mixture Toxicity of SN2-Reactive Soft Electrophiles: 2—Evaluation of Mixtures Containing Ethyl α-Halogenated Acetates

PubMed Central

Mooneyham, T.; Jeyaratnam, J.; Schultz, T. W.; Pöch, G.

2011-01-01

Four ethyl α-halogenated acetates were tested in (1) sham and (2) nonsham combinations and (3) with a nonreactive nonpolar narcotic. Ethyl iodoacetate (EIAC), ethyl bromoacetate (EBAC), ethyl chloroacetate (ECAC), and ethyl fluoroacetate (EFAC), each considered to be an SN2-H-polar soft electrophile, were selected for testing based on their differences in electro(nucleo)philic reactivity and time-dependent toxicity (TDT). Agent reactivity was assessed using the model nucleophile glutathione, with EIAC and EBAC showing rapid reactivity, ECAC being less reactive, and EFAC lacking reactivity at ≤250 mM. The model nonpolar narcotic, 3-methyl-2-butanone (3M2B), was not reactive. Toxicity of the agents alone and in mixture was assessed using the Microtox acute toxicity test at three exposure durations: 15, 30 and 45 min. Two of the agents alone (EIAC and EBAC) had TDT values >100%. In contrast, ECAC (74 to 99%) and EFAC (9 to 12%) had partial TDT, whereas 3M2B completely lacked TDT (<0%). In mixture testing, sham combinations of each agent showed a combined effect consistent with predicted effects for dose-addition at each time point, as judged by EC50 dose-addition quotient values. Mixture toxicity results for nonsham ethyl acetate combinations were variable, with some mixtures being inconsistent with the predicted effects for dose-addition and/or independence. The ethyl acetate–3M2B combinations were somewhat more toxic than predicted for dose-addition, a finding differing from that observed previously for α-halogenated acetonitriles with 3M2B. PMID:21452006

Fabrication of polymerized crystalline colloidal array thin film modified β-cyclodextrin polymer for paraoxon-ethyl and parathion-ethyl detection.

PubMed

Bui, Minh-Phuong N; Seo, Seong S

2014-01-01

We have developed an optical chemical sensor for the detection of organophosphate (OP) compounds using a polymerized crystalline colloidal array (PCCA) thin film composed of a close-packed colloidal array of polystyrene particles. The PCCA thin film was modified with β-cyclodextrin (β-CD) polymer as a capping cavity for the selective detection of paraoxon-ethyl and parathion-ethyl chemical agents. The fabrication of the modified PCCA thin film was optimized and the structure was characterized using scanning electron microscopy (SEM). The arrangement of polystyrene particles in the PCCA follows a pattern of the fcc (111) planes with strong diffraction peak in the visible spectral region and pH dependence. The diffraction peak of the β-CD modified PCCA thin film showed a red shift according to the change of paraoxon-ethyl and parathion-ethyl concentrations at a fast response time (10 s) and high sensitivity with detection limits of 2.0 and 3.4 ppb, respectively. Furthermore, the proposed interaction mechanism of β-CD with paraoxon-ethyl and parathion-ethyl in the β-CD modified PCCA thin film were discussed.

Hydroxide as general base in the saponification of ethyl acetate.

PubMed

Mata-Segreda, Julio F

2002-03-13

The second-order rate constant for the saponification of ethyl acetate at 30.0 degrees C in H(2)O/D(2)O mixtures of deuterium atom fraction n (a proton inventory experiment) obeys the relation k(2)(n) = 0.122 s(-1) M(-1) (1 - n + 1.2n) (1 - n + 0.48n)/(1 - n + 1.4n) (1 - n + 0.68n)(3). This result is interpreted as a process where formation of the tetrahedral intermediate is the rate-determining step and the transition-state complex is formed via nucleophilic interaction of a water molecule with general-base assistance from hydroxide ion, opposite to the direct nucleophilic collision commonly accepted. This mechanistic picture agrees with previous heavy-atom kinetic isotope effect data of Marlier on the alkaline hydrolysis of methyl formate.

Characterization of chemical agent transport in paints.

PubMed

Willis, Matthew P; Gordon, Wesley; Lalain, Teri; Mantooth, Brent

2013-09-15

A combination of vacuum-based vapor emission measurements with a mass transport model was employed to determine the interaction of chemical warfare agents with various materials, including transport parameters of agents in paints. Accurate determination of mass transport parameters enables the simulation of the chemical agent distribution in a material for decontaminant performance modeling. The evaluation was performed with the chemical warfare agents bis(2-chloroethyl) sulfide (distilled mustard, known as the chemical warfare blister agent HD) and O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX), an organophosphate nerve agent, deposited on to two different types of polyurethane paint coatings. The results demonstrated alignment between the experimentally measured vapor emission flux and the predicted vapor flux. Mass transport modeling demonstrated rapid transport of VX into the coatings; VX penetrated through the aliphatic polyurethane-based coating (100 μm) within approximately 107 min. By comparison, while HD was more soluble in the coatings, the penetration depth in the coatings was approximately 2× lower than VX. Applications of mass transport parameters include the ability to predict agent uptake, and subsequent long-term vapor emission or contact transfer where the agent could present exposure risks. Additionally, these parameters and model enable the ability to perform decontamination modeling to predict how decontaminants remove agent from these materials. Published by Elsevier B.V.

Kinetic study of the reaction of the hydroxyl radical (OH) with methyl ethyl ketone (2-butanone) and its deuterated isotopomers at low pressure

NASA Astrophysics Data System (ADS)

Liljegren, J. A.; Stevens, P. S.

2012-12-01

Methyl ethyl ketone (2-butanone) in the atmosphere comes from a variety of sources. It is produced commercially as an industrial ketone. It can be formed as a result of the OH or Cl-initiated oxidation of C4-C6 alkanes, primarily n-butane, or from the reaction of some alkenes with OH or O3. Biogenic sources include direct emissions from certain plants as well as emissions from decaying plant matter. Methyl ethyl ketone is removed from the atmosphere primarily by its reaction with OH. A product of this reaction includes acetaldehyde, which is a hazardous air pollutant, can further react to produce peroxy acetyl nitrate (PAN), and can be a significant source of free radicals to the atmosphere. The absolute rate constant for the reaction of OH with methyl ethyl ketone has been measured as a function of temperature at low pressure using discharge-flow techniques coupled with laser induced fluorescence (LIF) detection of OH. In addition, measurements of the rate constants for the reactions of OH with two deuterated isotopomers of methyl ethyl ketone, including CD3C(O)CH2CH3 and CH3C(O)CD2CD3, will be presented to gain a better understanding of the mechanism for this reaction. Theoretical studies of the potential energy surface for this reaction suggest that the reaction proceeds through the formation of a hydrogen-bonded pre-reactive complex, similar to that of several other atmospherically relevant oxygenated VOCs such as acetone, acetic acid, and hydroxyacetone.

Synthesis and characterization of bis-(2-cyano-1-methyl-3-{2- {{(5-methylimidazol-4-yl)methyl}thio}ethyl)guanidine copper(II) sulfate tetrahydrate

NASA Astrophysics Data System (ADS)

Rahardjo, Sentot B.; Endah Saraswati, Teguh; Pramono, Edy; Fitriana, Nur

2016-02-01

Complex of copper(II) with 2-cyano-1-methyl-3-{2-{{(5-methylimidazol-4- yl)methyl}thio}ethyl)guanidin(xepamet) had been synthesized in 1 : 4 mole ratio of metal to the ligand in methanol. The complex was characterized by metal analysis, thermal gravimetry/differential thermal analyzer (TG/DTA), molar conductivity meter, (Fourier transform infrared spectroscopy) FT-IR, UV-Vis spectroscopy, and magnetic susceptibility balance. The molar conductivity measurement shows that the complex was 2: 1 for electrolyte and SO42- which was acting as a counter ion. The thermal analysis by Thermogravimetric (TG) indicates that the complex contained four molecules of H2O. The Infrared spectral data indicates that functional groups of (C=N) imidazole and (C-S) are coordinated to the center ion Cu2+. Magnetic moment measurement shows that the complex is paramagnetic with peff = 1.78 ± 0.01 BM. Electronic spectra of the complex show a broad band at 608 nm (16447.23 cm-1) are due to Eg→T2g transition. Based on those of characteristics, The complex formula was estimated as [Cu(xepamet)2]SO4.4H2O. The structure of [Cu(xepamet)2]SO4.4H2O complex is probably square planar.

Enhancement by O6-benzyl-N2-acetylguanosine of N'-[2-chloroethyl]-N-[2-(methylsulphonyl)ethyl]-N'-nitrosourea therapeutic index on nude mice bearing resistant human melanoma.

PubMed Central

Debiton, E.; Cussac-Buchdhal, C.; Mounetou, E.; Rapp, M.; Dupuy, J. M.; Maurizis, J. C.; Veyre, A.; Madelmont, J. C.

1997-01-01

The exposure of cells to O6-benzyl-N2-acetylguanosine (BNAG) and several guanine derivatives is known to reduce the activity of O6-alkylguanine-DNA alkyltransferase (MGMT) and to enhance the sensitivity of Mer+ (methyl enzyme repair positive) tumour cells to chloroethylnitrosoureas (CENUs) in vitro and in vivo. High water solubility and the pharmacokinetic properties of BNAG make it a candidate for simultaneous administration with CENUs by the i.v. route in human clinical use. In vivo we have shown previously that BNAG significantly increases the efficiency of N'-[2-chloroethyl]-N-[2-(methylsulphonyl)ethyl]-N'-nitrosourea (cystemustine) against M4Beu melanoma cells (Mer+) through its cytostatic activity by the i.p. route, but also increases its toxicity. To investigate the toxicity of BNAG and cystemustine when administered simultaneously in mice, we compared the maximum tolerated dose and LD50 doses of cystemustine alone or in combination with 40 mg kg(-1) BNAG by the i.p. route. The toxicity of cystemustine was enhanced by a factor of almost 1.44 when combined with BNAG. To compare the therapeutic index of cystemustine alone and the cystemustine/BNAG combination, pharmacological tests were carried out in nude mice bearing Mer+ M4Beu human melanoma cells. Isotoxic doses were calculated using the 1.44 ratio. The treatments were administered three times by the i.v. route on days 1, 5 and 9 after s.c. inoculation of tumour cells. Although the toxicities of the treatments were equal, BNAG strongly enhanced tumour growth inhibition. These results demonstrate the increase of the therapeutic index of cystemustine by BNAG and justify the use of BNAG to enhance nitrosourea efficiency in vivo by i.v. co-injection. PMID:9365163

The ν 3 and 2ν 3 bands of 32S 16O 3, 32S 18O 3, 34S 16O 3, and 34S 18O 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharpe, Steven W.; Blake, Thomas A.; Sams, Robert L.

2003-12-01

The fifth of a series of publications on the high resolution rotation-vibration spectra of sulfur trioxide reports the results of a systematic study of the v3(é) and 2v3(A1'+E') infrared bands of the four symmetric top isotopomers 32S 16O 3, 34S 16O 3, 32S 18O 3, and 34S 18O 3. An internal coupling between the l = 0 and l = +2 levels of the 2v3 (A1'+E') states was observed. This small perturbation results in a level crossing between K-l = 9 and 12, in consequence of which the band origins of the A1', l=0 “ghost” states could be determined tomore » a high degree of accuracy. Ground and upper state rotational as well as vibrational anharmonicity constants are reported. The constants for the center-of-mass substituted species 32S 16O 3 and 34S 16O 3 vary only slightly, as do the constants for the 32S 18O 3, 34S 18O 3 pair. The S-O bond lengths for the vibrational ground states of the species 32S 16O 3, 34S 16O 3, 32S 18O 3 and 34S 18O 3, are, respectively, 141.981992(6), 141.979412(20), 150.605240(73), and 150.602348(73) pm, where the uncertainties, given in parentheses, are two standard deviations and refer to the last digits of the associated quantity.« less

40 CFR 180.183 - O,O-Diethyl S-[2-(ethyl-thio)ethyl] phosphorodithioate; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Barley, straw 5.0 1/30/10 Bean, lima 0.75 None Bean, snap, succulent 0.75 None Broccoli 0.75 None..., meat byproducts 0.05 1/30/10 Cauliflower 0.75 None Coffee, green bean 0.2 None Cotton, undelinted seed...

40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10110 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10111 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10111 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10110 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10111 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10111 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10111 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10110 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10110 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexanoic acid, 2-ethyl-, mixed... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10110 Hexanoic acid, 2-ethyl-, mixed... to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, mixed diesters with...

Wild Raspberry Subjected to Simulated Gastrointestinal Digestion Improves the Protective Capacity against Ethyl Carbamate-Induced Oxidative Damage in Caco-2 Cells

PubMed Central

Chen, Wei; Xu, Yang; Zhang, Lingxia; Li, Ya; Zheng, Xiaodong

2016-01-01

Ethyl carbamate (EC), a probable human carcinogen, occurs widely in many fermented foods. Previous studies indicated that EC-induced cytotoxicity was associated with oxidative stress. Wild raspberries are rich in polyphenolic compounds, which possess potent antioxidant activity. This study was conducted to investigate the protective effect of wild raspberry extracts produced before (RE) and after in vitro simulated gastrointestinal digestion (RD) on EC-induced oxidative damage in Caco-2 cells. Our primary data showed that ethyl carbamate could result in cytotoxicity and genotoxicity in Caco-2 cells and raspberry extract after digestion (RD) may be more effective than that before digestion (RE) in attenuating toxicity caused by ethyl carbamate. Further investigation by fluorescence microscope revealed that RD may significantly ameliorate EC-induced oxidative damage by scavenging the overproduction of intracellular reactive oxygen species (ROS), maintaining mitochondrial function and preventing glutathione (GSH) depletion. In addition, HPLC-ESI-MS results showed that the contents of identified polyphenolic compounds (esculin, kaempferol O-hexoside, and pelargonidin O-hexoside) were remarkably increased after digestion, which might be related to the better protective effect of RD. Overall, our results demonstrated that raspberry extract undergoing simulated gastrointestinal digestion may improve the protective effect against EC-induced oxidative damage in Caco-2 cells. PMID:26788245

Degradation Kinetics of VX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gary S. Groenewold

2010-12-01

O-ethyl S-(2-diisopropylaminoethyl)phosphonothiolate (VX) is the most toxic of the conventional chemical warfare agents. It is a persistent compound, an attribute derived from its relative involatility and slow rates of hydrolysis. These properties suggest that VX can linger in an exposed environment for extended periods of time long after the air has cleared. Concern over prolonged risk from VX exposure is exacerbated by the fact that it poses a dermal contact hazard. Hence a detailed understanding of volatilization rates, and degradation pathways and rates occurring in various environments is needed. Historically, volatilization has not been considered to be an important mechanismmore » for VX depletion, but recent studies have shown that a significant fraction of VX may volatilize, depending on the matrix. A significant body of research has been conducted over the years to unravel VX degradation reaction pathways and to quantify the rates at which they proceed. Rigorous measurement of degradation rates is frequently difficult, and thus in many cases the degradation of VX has been described in terms of half lives, while in fewer instances rate constants have been measured. This variable approach to describing degradation kinetics reflects uncertainty regarding the exact nature of the degradation mechanisms. In this review, rates of VX degradation are compared on the basis of pseudo-first order rate constants, in order to provide a basis for assessing likelihood of VX persistence in a given environment. An issue of specific concern is that one VX degradation pathway produces S-2-(diisopropylaminoethyl) methylphosphonothioic acid (known as EA2192), which is a degradation product that retains much of the original toxicity of VX. Consequently degradation pathways and rates for EA2192 are also discussed.« less

Rotational isomers of N-(β-phenylpropionyl)alanine ethyl dithioester: a Raman spectroscopic and MO study

NASA Astrophysics Data System (ADS)

Fausto, R.; Teixeira-Dias, J. J. C.; Tonge, P. J.; Carey, P. R.

1994-07-01

Raman spectra of N-(β-phenylpropionyl)alanine ethyl dithioester (C 6H 5CH 2CH 2C(O)NHCH(CH 3)C(S)SC 2H 5) in CCl 4 and CH 3CN solutions were measured as a function of temperature and the enthalpy differences (Δ H) between rotational isomers differing by internal rotation around the NHCH(CH 3) and CH(CH 3)C(S) bonds (forms A, B and C 5) were evaluated from relative band intensities. The spectroscopic results are consistent with a greater thermodynamical stability of the B-type conformer, where the N and S (thiol) atoms are in close contact. In addition, a comparison of the measured Δ H(A-B) for the present molecules with previously reported values for a series of similar glycine-based ethyl dithioesters shows that the presence of the extra CH 3 group at the α-carbon atom leads to a stabilization of the B-type conformer relative to the A-type form in the alanine-based dithioester. Semiempirical AM1 molecular orbital calculations were also performed on the title molecule and on its glycine analogue, N(β-phenylpropionyl)glycine ethyl dithioester. In general terms, the results of these calculations agree with the experimental findings, thus providing good theoretical support for the experimental data.

40 CFR 721.7700 - Poly(oxy-1,2-ethanediyl), α-hydro-ω-(oxiranylmethoxy)-, ether with 2-ethyl-2-(hydroxymethyl)-1,3...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Poly(oxy-1,2-ethanediyl), α-hydro-Ï... Poly(oxy-1,2-ethanediyl), α-hydro-ω-(oxiranylmethoxy)-, ether with 2-ethyl-2-(hydroxymethyl)-1,3... substance identified as poly(oxy-1,2-ethanediyl),α-hydro-ω-(oxiranylmethoxy)-, ether with 2-ethyl-2...

40 CFR 721.7700 - Poly(oxy-1,2-ethanediyl), α-hydro-ω-(oxiranylmethoxy)-, ether with 2-ethyl-2-(hydroxymethyl)-1,3...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Poly(oxy-1,2-ethanediyl), α-hydro-Ï... Poly(oxy-1,2-ethanediyl), α-hydro-ω-(oxiranylmethoxy)-, ether with 2-ethyl-2-(hydroxymethyl)-1,3... substance identified as poly(oxy-1,2-ethanediyl),α-hydro-ω-(oxiranylmethoxy)-, ether with 2-ethyl-2...

Synthesis and Mesomorphic Behavior of Poly((2S, 3S)-(+)-2-Chloro-3- Methylpentyl 4’-(Omega-Vinyloxyalkyloxy)biphenyl-4-Carboxylate)s with Ethyl and Propyl Alkyl Groups

DTIC Science & Technology

1994-06-30

1 . Synthesis of (2S, 3S)-(+)-2-chloro-3-methyl-pentyl 4’-(2-vinyloxyethyloxy) biphenyl-4-carboxylate (15-2...CH2)2-),7.65 (d, 3=8.3Hz, 2 ArH, m to -COO-), 8.11 (d, J=7.4Hz, 2 ArH, o to -COO-). 3-Chloroprop~yl- 1 -vinyl ether (13-3) The mixture of 3- chloropropan ...VA .% fo - " A’* *i f’. - % .oL.,ae- a * 1 nOl-6..io. Ocw. ’•.1ý’ ..a.. :l•t :...•.t ;,,31 -. 1 " 1 . 2 . 10 1 -- Of , • l 0’ i’*J.. e t *no suaqetg

40 CFR 721.10130 - Quino[2,3-b]acridine-7,14-dione, 5,12-dihydro-ar-[4-[[2-(sulfooxy)ethyl]substituted]phenyl...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-dihydro-ar-[4-[[2-(sulfooxy)ethyl]substituted]phenyl]-, monosodium salt (generic). 721.10130 Section 721... Quino[2,3-b]acridine-7,14-dione, 5,12-dihydro-ar-[4-[[2-(sulfooxy)ethyl]substituted]phenyl]-, monosodium... substance identified generically as quino[2,3-b]acridine-7,14-dione, 5,12-dihydro-ar-[4-[[2-(sulfooxy)ethyl...

Chlorimuron-ethyl

Integrated Risk Information System (IRIS)

Integrated Risk Information System ( IRIS ) Chemical Assessment Summary U.S . Environmental Protection Agency National Center for Environmental Assessment This IRIS Summary has been removed from the IRIS database and is available for historical reference purposes . ( July 2016 ) Chlorimuron - ethyl

Effects of S-2-(3-Methylaminopropylamino)ethyl Phosphorothioic Acid (WR- 3689), Alone or Combined with Caffeine, on Catecholamine Content of Mouse Hypothalamus

DTIC Science & Technology

1993-01-01

INSTITUTE I cIEINTIFIC•IEPOET SR93-16 Effects of S-2-(3-Methylaminopropylamino)ethyl Phosphorothioic Acid (WR-3689), Alone or Combined with Caffeine...and 220 pg/mg and 69 and 94 pg/mg of hypothalamic tissue, respectively. WR- 3689 had no effect on the content of NE and DA. In contrast, NE increased...increased to 142 ± 13 pg/mg (P < 0.05) 4 hr after injection of 40 mg/kg of caffeine. The combination of WR-3689 and caffeine had no effect on NE and DA

Simultaneous Time-concentration Analysis of Soman and VX Adducts to Butyrylcholinesterase and Albumin by LC-MS-MS.

PubMed

Lee, Jin Young; Kim, Changhwan; Lee, Yong Han

2018-06-01

A sensitive method for the purification and determination of two protein adducts, organophosphorus (OP)-BChE and OP-albumin adducts, in a single sample using a simultaneous sample preparation method was developed and validated using liquid chromatography-tandem mass spectrometry. First, we isolated O-ethyl S-2-diisopropylaminoethyl methyl phosphonothiolate (VX) and O-pinacolyl methylphosphonofluoridate (soman, GD)-BChE adducts using an immunomagnetic separation (IMS) method and the HiTrap™ Blue affinity column was subsequently used to isolate and purify VX and GD-albumin adducts from the plasma of rhesus monkeys exposed to nerve agents. Additionally, we examined the time-concentration profiles of two biomarkers, VX and GD-nonapeptides and VX and GD-tyrosines, derived from OP-BChE and OP-albumin adducts up to 8 weeks after exposure. Based on the results, we determined that VX and GD-tyrosine is more suitable than VX and GD-nonapeptide as a biomarker owing to its longevity. This integrated approach is expected to be applicable for the quantification of other OP-BChE and OP-albumin adducts in human plasma, thus serving as a potential generic assay for exposure to nerve agents.

40 CFR 721.10401 - Oxirane, 2-ethyl-, polymer with oxirane, mono-C11-15-sec-alkyl ethers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Oxirane, 2-ethyl-, polymer with... Significant New Uses for Specific Chemical Substances § 721.10401 Oxirane, 2-ethyl-, polymer with oxirane...) The chemical substance identified as oxirane, 2-ethyl-, polymer with oxirane, mono C11-15-sec-alkyl...

40 CFR 721.10400 - Oxirane, 2-ethyl-, polymer with oxirane, mono-C12-14-sec-alkyl ethers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Oxirane, 2-ethyl-, polymer with... Significant New Uses for Specific Chemical Substances § 721.10400 Oxirane, 2-ethyl-, polymer with oxirane...) The chemical substance identified as oxirane, 2-ethyl-, polymer with oxirane, mono-C12-14-sec-alkyl...

THz and Ft-Ir Study of 18-O Isotopologues of Sulfur Dioxide: 32S16O18O and 32S18O_2

NASA Astrophysics Data System (ADS)

Margulès, L.; Motiyenko, R. A.; Demaison, J.; Perrin, Agnes; Kwabia Tchana, F.; Manceron, Laurent

2016-06-01

Sulfur dioxide is a molecule that have a great interest in different domains: for atmospheric and planetology chemistry, it is also ubiquitous and abundant in interstellar medium. If the 16O species were extensively studied, this is not the case of the 18O isotopologues. The aim of this study is first to complete the rotational spectra of the ground state with these new measurements up to 1.5 THz, previous measurements are up to 1050 GHz for the 32S16O18O species, and 145 GHz concerning the 32S18O_2 species. The second part is making a global fit of the rotational and vibrational transitions for the excited vibrational states. For the v_2 band, we will complete the recent I.R. analysis. About the triad (v_1, 2v_2, v_3): 32S18O_2 species was studied, but not the 32S16O18O one. and 145 GHz concerning the 32S18O_2 species. The second part is making a global fit of the rotational and vibrational transitions for the excited vibrational states. For the v_2 band, we will complete the recent I.R. analysis. About the triad (v_1, 2v_2, v_3): 32S18O_2 species was studied, but not the 32S16O18O one. The FT-IR spectra were recorded on the AILES Beamline at Synchrotron SOLEIL using the Synchrotron light source, coupled to the Bruker IFS125HR Fourier transform spectrometer. The THz spectra were obtained from 150 to 1500 GHz using the Lille's solid state spectrometer. The analysis is in progress, the latest results will be presented. Support from the French Laboratoire d'Excellence CaPPA (Chemical and Physical Properties of the Atmosphere) through contract ANR-10-LABX-0005 of the Programme d'Investissements d'Avenir is acknowledged Belov, S. P.; et al., 1998, J. Mol. Spectrosc. 191, 17 Lindermayer, J.; et al., 1985, J. Mol. Spectrosc. 110, 357 Gueye, F.; et al. Mol. Phys. in press Ulenikov, O. N.; et al., 2015, JQSRT 166, 13 Brubach, J.; et al., 2010, AIP Conf. Proc. 1214, 81 Zakharenko, O.; et al., 2015, J. Mol. Spectrosc. 317, 41

Kinetics of the gas-phase reaction between ozone and three unsaturated oxygenated compounds: Ethyl 3,3-dimethyl acrylate, 2-methyl-2-pentenal and 6-methyl-5-hepten-2-one at atmospheric pressure

NASA Astrophysics Data System (ADS)

Gaona Colmán, Elizabeth; Blanco, María B.; Barnes, Ian; Teruel, Mariano A.

2015-05-01

Rate coefficients for the gas-phase reactions of O3 molecules with three unsaturated oxygenated compounds have been determined using the relative kinetic technique in an environmental chamber with FTIR detection of the reactants at (298 ± 2) K in 760 Torr total pressure of synthetic air. The following rate coefficients (in units of 10-17 cm3 molecule-1 s-1) were determined: ethyl 3,3-dimethyl acrylate (0.82 ± 0.19), 2-methyl-2-pentenal (0.71 ± 0.16) and 6-methyl-5-hepten-2-one (26 ± 7). The different reactivity of the unsaturated oxygenated compounds toward O3 is discussed in terms of their chemical structure. In addition, a correlation between the reactivity of structurally different unsaturated compounds (alkenes and unsaturated oxygenated VOCs, such as ethers, esters, aldehydes, ketones and alcohols) toward O3 molecules and the HOMO (Highest Occupied Molecular Orbital) of the compounds is presented. Using the kinetic parameters determined in this work, residence times of these unsaturated compounds in the atmosphere with respect to reaction with O3 have been calculated. In urban and rural areas the main sink of 6-methyl-5-hepten-2-one is reaction with O3 molecules with a residence time in the order of few minutes.

S-TiO2/S-reduced graphene oxide for enhanced photoelectrochemical water splitting

NASA Astrophysics Data System (ADS)

Elbakkay, Mohamed H.; El Rouby, Waleed M. A.; El-Dek, S. I.; Farghali, Ahmed A.

2018-05-01

Sulfur-doped titanium oxide on the surface of sulfur-doped reduced graphene oxide nanocomposites (S-TiO2/S-RGO) were successfully synthesized for the first time through a simple low cost solvothermal reaction process. The sulfur doping was detected in both TiO2 matrix and carbon framework structure of reduced graphene oxide using X-ray photoelectron spectroscopy (XPS) and Energy-dispersive X-ray spectroscopy (EDX). Cross-sectional AFM analysis of S-RGO nanosheets reveals a thickness of 0.51 nm which is much thinner than those previously reported of heteroatom doped-RGO, confirming the single-layer feature. When the as-prepared (S-TiO2/S-RGO) nanocomposites are utilized as photoanodes for photoelectrochemical (PEC) water splitting, they exhibited an enhanced photoelectrochemical performance and long-term stability. The photocurrent density of S-TiO2/S-RGO(0.2) photoanode revealed 3.36 mA/cm2 at 1 V vs Ag/AgCl which is considered 3 times compared to bare synthesized TiO2. This improvement in the photocurrent density was attributed to the increased separation rate of photogenerated electrons and holes and efficient visible light harvesting as a result of the successful combination of the S-TiO2 and the S-RGO in the same nanocomposite photoanode. This promising result presents a new approach for the synthesis of high-efficient future metal-free photoelectrocatalysts.

40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... combined residues of the herbicide fenoxaprop-ethyl [(±)-ethyl 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy... herbicide fenoxaprop-ethyl, [(±)-ethyl 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoic acid], and its...

Mechanism of MnS Precipitation on Al2O3-SiO2 Inclusions in Non-oriented Silicon Steel

NASA Astrophysics Data System (ADS)

Li, Fangjie; Li, Huigai; Huang, Di; Zheng, Shaobo; You, Jinglin

2018-05-01

This study investigates the mechanism of MnS precipitation on Al2O3-SiO2 inclusions during the solidification of non-oriented silicon steel, especially the influence of the phase structures and sizes of the oxides on the MnS precipitation, by scanning electron microscopy and transmission electron microscopy coupled with energy dispersive spectrometry. The investigation results show that MnS tends to nucleate on submicron-sized Al2O3-SiO2 inclusions formed by interdendritic segregation and that it covers the oxides completely. In addition, MnS can precipitate on micron-sized oxides and its precipitation behavior is governed by the phase structure of the oxides. The MnS embryo formed in a MnO-containing oxide can act as a substrate for MnS precipitation, thus permitting further growth via diffusion of solute atoms from the matrix. MnS also precipitates in a MnO-free oxide by the heterogeneous nucleation mechanism. Furthermore, MnS is less prone to precipitation in the Al2O3-rich regions of the Al2O3-SiO2 inclusions; this can be explained by the high lattice disregistry between MnS and Al2O3.

Trapping {BW12}2 tungstoborate: synthesis and crystal structure of hybrid [{(H2BW12O42)2O}{Mo6O6S6(OH)4(H2O)2}]14- anion.

PubMed

Korenev, V S; Abramov, P A; Vicent, C; Mainichev, D A; Floquet, S; Cadot, E; Sokolov, M N; Fedin, V P

2012-12-28

Reaction between monolacunary {BW(11)} tungstoborate and oxothiocationic building block, {Mo(2)O(2)S(2)}, results in the formation of a new polyoxothiometalate with a unique architecture in which two [H(2)BW(12)O(43)](9-) tungstoborate subunits are linked together with a hexamolybdate [Mo(V)(6)O(6)S(6)(OH)(4)(H(2)O)(2)](2+) bridge.

Structure determination of two structural analogs, named 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-fluorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C23H16F2N4S) and 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-chlorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C23H16ClFN4S) by synchrotron X-ray powder diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gündoğdu, Gülsüm; Aytaç, Sevim Peri; Müller, Melanie

Two novel compounds, 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-fluorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C 23H 16F 2N 4S) (1) and 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-chlorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C 23H 16ClFN 4S) (2), have been designed and synthesized as cytotoxic agents. The compounds were characterized by infrared, proton nuclear magnetic resonance, mass spectral data, elemental analysis and X-ray powder diffraction. The present study comprises spectral data and crystal structures of these novel compounds determined from synchrotron X-ray powder diffraction data. The structure solutions were obtained by simulated annealing. The final structures were achieved by Rietveld refinement using soft restraints for all bond lengths, bond angles, and planar groups. Both compounds crystallize in space groupmore » $$P\\bar 1$$,Z= 2, with the unit-cell parametersa= 6.37433(9),b= 11.3641(2),c= 14.09115(19) Å,α= 80.1740(8)°,β= 85.1164(8)°,γ= 80.9831(10)°,V= 991.55(3) Å 3of compound (1) anda= 6.53736(6),b= 11.55725(15),c= 14.01373(13) Å,α= 80.3323(7)°,β= 84.8939(6)°,γ= 79.3954(8)°,V= 1024.08(2) Å 3of compound (2). Structural analyses reveal that the title compounds are isostructural.« less

40 CFR 721.4468 - 1H-Imidazole, 2-ethyl-4,5-dihydro-4-methyl-.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1H-Imidazole, 2-ethyl-4,5-dihydro-4... Specific Chemical Substances § 721.4468 1H-Imidazole, 2-ethyl-4,5-dihydro-4-methyl-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1H-imidazole...

High light harvesting efficiency CuInS2 quantum dots/TiO2/MoS2 photocatalysts for enhanced visible light photocatalytic H2 production.

PubMed

Yuan, Yong-Jun; Fang, Gaoliang; Chen, Daqin; Huang, Yanwei; Yang, Ling-Xia; Cao, Da-Peng; Wang, Jingjing; Yu, Zhen-Tao; Zou, Zhi-Gang

2018-04-24

Expanding the photoresponse range of TiO2-based photocatalysts is of great interest for photocatalytic H2 production. Herein, noble-metal-free CuInS2 quantum dots were employed as a novel inorganic dye to expand the visible light absorption of TiO2/MoS2 for solar H2 generation. The as-prepared CuInS2/TiO2/MoS2 photocatalysts exhibit broad absorption from the ultraviolet to near-infrared region. Under visible light irradiation (λ > 420 nm), the CuInS2/TiO2/MoS2 photocatalyst with 0.6 mmol g-1 CuInS2 and 0.5 wt% MoS2 showed the highest H2 evolution rate with a value of 1034 μmol h-1 g-1. Moreover, a considerable H2 evolution rate of 141 μmol h-1 g-1 was obtained under the irradiation of the optimized CuInS2/TiO2/MoS2 photocatalyst with >500 nm light. The reaction mechanism of the CuInS2/TiO2/MoS2 photocatalyst for photocatalytic H2 evolution was investigated in detail by photoluminescence decay study, and the results showed that the photoexcited electrons of CuInS2 can be transferred efficiently through TiO2 to MoS2 and then react with the absorbed protons to generate H2. The reported sensitization strategy tremendously improves the visible light absorption capacity and the photocatalytic performance of TiO2-based photocatalysts.

Synthesis of zinc sulfide nanoparticles during zinc oxidization by H2S and H2S/H2O supercritical fluids

NASA Astrophysics Data System (ADS)

Vostrikov, A. A.; Fedyaeva, O. N.; Sokol, M. Ya.; Shatrova, A. V.

2014-12-01

Formation of zinc sulfide nanoparticles was detected during interaction of bulk samples with hydrogen sulfide at supercritical parameters. Synthesis proceeds with liberation of H2 by the reaction nZn + nH2S = (ZnS) n + nH2. It has been found by the X-ray diffraction method, scanning electron microscopy, and mass spectrometry that the addition of water stimulates coupled reactions of nanoparticle synthesis nZn + nH2O = (ZnO) n + nH2 and (ZnO) n + nH2S = (ZnS) n + nH2O and brings about an increase in the synthesis rate and morphological changes of (ZnS) n nanoparticles.

Synthesis of TiO2-CNT hybrid nanocatalyst and its application in direct oxidation of H2S to S

NASA Astrophysics Data System (ADS)

Daraee, Maryam; Baniadam, Majid; Rashidi, Alimorad; Maghrebi, Morteza

2018-07-01

In this study, a TiO2-CNT hybrid catalyst has been synthesized and its catalytic activity in the oxidation of H2S to S has been investigated and compared with those of TiO2 nanoparticles and pyrolyzed TiO2-CNT hybrid (P-TiO2-CNT). The optimum catalyst amount was determined using central composite design (CCD) method. Catalysts were characterized by various analytical techniques. The H2S conversion, sulfur selectivity and yield at the optimal temperature of 200 °C and O2/H2S ratio of 0.5 were 98.3, 99.5 and 97%, respectively. TiO2-CNT16% catalyst has a higher surface area than TiO2 nanoparticles and P-TiO2-CNT. In addition, the former catalyst gives a high conversion of H2S and sulfur selectivity at 200 °C and O2/H2S ratio of 0.5 compared with the latter two catalysts. The superior conversion (over 10%) of TiO2-CNT16% hybrid compared to TiO2 nanoparticles can be attributed to the synergistic effects of TiO2 and CNT, the reduced band gap of TiO2-CNT16% hybrid and high specific surface area of the catalyst.

TiO2-SnS2 nanocomposites: solar-active photocatalytic materials for water treatment.

PubMed

Kovacic, Marin; Kusic, Hrvoje; Fanetti, Mattia; Stangar, Urska Lavrencic; Valant, Matjaz; Dionysiou, Dionysios D; Bozic, Ana Loncaric

2017-08-01

The study is aimed at evaluating TiO 2 -SnS 2 composites as effective solar-active photocatalysts for water treatment. Two strategies for the preparation of TiO 2 -SnS 2 composites were examined: (i) in-situ chemical synthesis followed by immobilization on glass plates and (ii) binding of two components (TiO 2 and SnS 2 ) within the immobilization step. The as-prepared TiO 2 -SnS 2 composites and their sole components (TiO 2 or SnS 2 ) were inspected for composition, crystallinity, and morphology using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) analyses. Diffuse reflectance spectroscopy (DRS) was used to determine band gaps of immobilized TiO 2 -SnS 2 and to establish the changes in comparison to respective sole components. The activity of immobilized TiO 2 -SnS 2 composites was tested for the removal of diclofenac (DCF) in aqueous solution under simulated solar irradiation and compared with that of single component photocatalysts. In situ chemical synthesis yielded materials of high crystallinity, while their morphology and composition strongly depended on synthesis conditions applied. TiO 2 -SnS 2 composites exhibited higher activity toward DCF removal and conversion in comparison to their sole components at acidic pH, while only in situ synthesized TiO 2 -SnS 2 composites showed higher activity at neutral pH.

Ethyl 4-anilino-2,6-bis­(4-chloro­phen­yl)-1-phenyl-1,2,5,6-tetra­hydro­pyridine-3-carboxyl­ate

PubMed Central

Yu, Jianfeng; Tang, Shiming; Zeng, Jingbin; Yan, Zifeng

2013-01-01

The title compound, C32H28Cl2N2O2, was synthesized by a multicomponent reaction of 4-chloro­benzaldehyde, aniline and ethyl aceto­acetate. The central 1,2,5,6-tetra­hydro­pyridine ring exhibits a distorted boat conformation and the two chloro­phenyl rings attached to the central ring at positions 2 and 6 are oriented in opposite directions. The two O atoms of the eth­oxy­carbonyl group are involved in intra­molecular N—H⋯O and C—H⋯O hydrogen bonds. In the crystal, weak C—H⋯O hydrogen bonds link mol­ecules related by translation along the b axis into chains. PMID:23795109

Impact of two ionic liquids, 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium methylphosphonate, on Saccharomyces cerevisiae: metabolic, physiologic, and morphological investigations.

PubMed

Mehmood, Nasir; Husson, Eric; Jacquard, Cédric; Wewetzer, Sandra; Büchs, Jochen; Sarazin, Catherine; Gosselin, Isabelle

2015-01-01

Ionic liquids (ILs) are considered as suitable candidates for lignocellulosic biomass pretreatment prior enzymatic saccharification and, obviously, for second-generation bioethanol production. However, several reports showed toxic or inhibitory effects of residual ILs on microorganisms, plants, and animal cells which could affect a subsequent enzymatic saccharification and fermentation process. In this context, the impact of two hydrophilic imidazolium-based ILs already used in lignocellulosic biomass pretreatment was investigated: 1-ethyl-3-methylimidazolium acetate [Emim][OAc] and 1-ethyl-3-methylimidazolium methylphosphonate [Emim][MeO(H)PO2]. Their effects were assessed on the model yeast for ethanolic fermentation, Saccharomyces cerevisiae, grown in a culture medium containing glucose as carbon source and various IL concentrations. Classical fermentation parameters were followed: growth, glucose consumption and ethanol production, and two original factors: the respiratory status with the oxygen transfer rate (OTR) and carbon dioxide transfer rate (CTR) of yeasts which were monitored online by respiratory activity monitoring systems (RAMOS). In addition, yeast morphology was characterized by environmental scanning electron microscope (ESEM). The addition of ILs to the growth medium inhibited the OTR and switched the metabolism from respiration (conversion of glucose into biomass) to fermentation (conversion of glucose to ethanol). This behavior could be observed at low IL concentrations (≤5% IL) while above there is no significant growth or ethanol production. The presence of IL in the growth medium also induced changes of yeast morphology, which exhibited wrinkled, softened, and holed shapes. Both ILs showed the same effects, but [Emim][MeO(H)PO2] was more biocompatible than [Emim][OAc] and could be better tolerated by S. cerevisiae. These two imidazolium-derived ILs were appropriate candidates for useful pretreatment of lignocellulosic biomass in the

Effect of Sulfur on Liquidus Temperatures in the ZnO-"FeO"-Al2O3-CaO-SiO2-S System in Equilibrium with Metallic Iron

NASA Astrophysics Data System (ADS)

Zhao, Baojun; Hayes, Peter C.; Jak, Evgueni

2011-10-01

The phase equilibria in the ZnO-"FeO"-Al2O3-CaO-SiO2-S system have been determined experimentally in equilibrium with metallic iron. A pseudoternary section of the form ZnO-"FeO"-(Al2O3+CaO+SiO2) for CaO/SiO2 = 0.71 (weight), (CaO+SiO2)/Al2O3 = 5.0 (weight), and fixed 2.0 wt pct S concentration has been constructed. It was found that the addition of 2.0 wt pct S to the liquid extends the spinel primary phase field significantly and decreases the size of the wustite primary phase field. The liquidus temperature in the wustite primary phase field is decreased by approximately 80 K and the liquidus temperature in the spinel primary phase field is decreased by approximately 10 K with addition of 2.0 wt pct S in the composition range investigated. It was also found that iron-zinc sulfides are present in some samples in the spinel primary phase field, which are matte appearing at low zinc concentrations and sphalerite (Zn,Fe)S at higher zinc concentrations. The presence of sulfur in the slag has a minor effect on the partitioning of ZnO between the wustite and liquid phases but no effect on the partitioning of ZnO between the spinel and liquid phases.

Commercial Ethyl Glucuronide (EtG) and Ethyl Sulfate (EtS) Testing is Not Vulnerable to Incidental Alcohol Exposure in Pregnant Women.

PubMed

Ondersma, Steven J; Beatty, Jessica R; Rosano, Thomas G; Strickler, Ronald C; Graham, Amy E; Sokol, Robert J

2016-01-02

Ethyl Glucoronide (EtG) and Ethyl Sulfate (EtS) have shown promise as biomarkers for alcohol and may be sensitive enough for use with pregnant women in whom even low-level alcohol use is important. However, there have been reports of over-sensitivity of EtG and EtS to incidental exposure to sources such as alcohol-based hand sanitizer. Further, few studies have evaluated these biomarkers among pregnant women, in whom the dynamics of these metabolites may differ. This study evaluated whether commercial EtG-EtS testing was vulnerable to high levels of environmental exposure to alcohol in pregnant women. Two separate samples of five nurses-one pregnant and the other postpartum, all of whom reported high levels of alcohol-based hand sanitizer use-provided urine samples before and 4-8 hours after rinsing with alcohol-based mouthwash and using hand sanitizer. The five pregnant nurses provided urine samples before, during, and after an 8-hour nursing shift, during which they repeatedly cleansed with alcohol-based hand sanitizer (mean 33.8 uses). The five postpartum nurses used hand sanitizer repeatedly between baseline and follow-up urine samples. No urine samples were positive for EtG-EtS at baseline or follow-up, despite use of mouthwash and-in the pregnant sample-heavy use of hand sanitizer (mean of 33.8 uses) throughout the 8-hour shift. Current, commercially available EtG-EtS testing does not appear vulnerable to even heavy exposure to incidental sources of alcohol among pregnant and postpartum women.

Commercial Ethyl Glucuronide (EtG) and Ethyl Sulfate (EtS) Testing is not Vulnerable to Incidental Alcohol Exposure in Pregnant Women

PubMed Central

Beatty, Jessica R.; Rosano, Thomas G.; Strickler, Ronald C.; Graham, Amy E.; Sokol, Robert J.

2016-01-01

Background Ethyl Glucoronide (EtG) and Ethyl Sulfate (EtS) have shown promise as biomarkers for alcohol and may be sensitive enough for use with pregnant women in whom even low-level alcohol use is important. However, there have been reports of over-sensitivity of EtG and EtS to incidental exposure to sources such as alcohol-based hand sanitizer. Further, few studies have evaluated these biomarkers among pregnant women, in whom the dynamics of these metabolites may differ. Objectives This study evaluated whether commercial EtG-EtS testing was vulnerable to high levels of environmental exposure to alcohol in pregnant women. Methods Two separate samples of five nurses—one pregnant and the other postpartum, all of whom reported high levels of alcohol-based hand sanitizer use—provided urine samples before and 4–8 hours after rinsing with alcohol-based mouthwash and using hand sanitizer. The five pregnant nurses provided urine samples before, during, and after an 8-hour nursing shift, during which they repeatedly cleansed with alcohol-based hand sanitizer (mean 33.8 uses). The five postpartum nurses used hand sanitizer repeatedly between baseline and follow-up urine samples. Results No urine samples were positive for EtG-EtS at baseline or follow-up, despite use of mouthwash and—in the pregnant sample—heavy use of hand sanitizer (mean of 33.8 uses) throughout the 8-hour shift. Conclusions/Importance Current, commercially available EtG-EtS testing does not appear vulnerable to even heavy exposure to incidental sources of alcohol among pregnant and postpartum women. PMID:26771303

49 CFR 173.322 - Ethyl chloride.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Ethyl chloride. 173.322 Section 173.322 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.322 Ethyl chloride. Ethyl chloride must be...

Crystal structure of (eth­oxy­ethyl­idene)di­methyl­aza­nium ethyl sulfate

PubMed Central

Tiritiris, Ioannis; Saur, Stefan; Kantlehner, Willi

2015-01-01

In the title salt, C6H14NO+·C2H5SO4 −, the C—N bond lengths in the cation are 1.2981 (14), 1.4658 (14) and 1.4707 (15) Å, indicating double- and single-bond character, respectively. The C—O bond length of 1.3157 (13) Å shows double-bond character, indicating charge delocalization within the NCO plane of the iminium ion. In the crystal, C—H⋯O hydrogen bonds between H atoms of the cations and O atoms of neighbouring ethyl sulfate anions are present, generating a three-dimensional network. PMID:26870525

Superconductivity in semimetallic B i 3 O 2 S 3

DOE PAGES

Li, L.; Parker, D.; Babkevich, P.; ...

2015-03-12

We report in this paper a further investigation on the thermodynamic and transport properties, and an assessment of theoretical calculations, for the BiS 2-layered Bi 3O 2S 3 superconductor. The polycrystalline sample is synthesized with a superconducting transition temperature of T c onset=5.75K and T c zero=4.03K (≈Tc mag) that drops to 3.3 K by applying a hydrostatic pressure of 6 kbar. Density-of-states (DOS) calculations give substantial hybridization between Bi, O, and S, with Bi the largest component of DOS, which supports the idea that the BiS 2 layer is relevant for producing electron-phonon coupling. An analysis of previously publishedmore » specific heat data for Bi 3O 2S 3 is additionally suggestive of a strong electron-phonon interaction in the Bi-O-S system. The analysis of the Seebeck coefficient results strongly suggests that Bi 3O 2S 3 is a semimetal. In fact, we found the semimetallic or narrow band gap behavior may occur in certain other materials in the BiS 2-layered class of materials, such as Bi 4O 4S 3.« less

Experimental studies of Debye-like process and structural relaxation in mixtures of 2-ethyl-1-hexanol and 2-ethyl-1-hexyl bromide

NASA Astrophysics Data System (ADS)

Preuß, M.; Gainaru, C.; Hecksher, T.; Bauer, S.; Dyre, J. C.; Richert, R.; Böhmer, R.

2012-10-01

Binary solutions of 2-ethyl-1-hexanol (2E1H) with 2-ethyl-1-hexyl bromide (2E1Br) are investigated by means of dielectric, shear mechanical, near-infrared, and solvation spectroscopy as well as dielectrically monitored physical aging. For moderately diluted 2E1H the slow Debye-like process, which dominates the dielectric spectra of the neat monohydroxy alcohol, separates significantly from the α-relaxation. For example, the separation in equimolar mixtures amounts to four decades in frequency. This situation of highly resolved processes allows one to demonstrate unambiguously that physical aging is governed by the α-process, but even under these ideal conditions the Debye process remains undetectable in shear mechanical experiments. Furthermore, the solvation experiments show that under constant charge conditions the microscopic polarization fluctuations take place on the time scale of the structural process. The hydrogen-bond populations monitored via near-infrared spectroscopy indicate the presence of a critical alcohol concentration, xc ≈ 0.5-0.6, thereby confirming the dielectric data. In the pure bromide a slow dielectric process of reduced intensity is present in addition to the main relaxation. This is taken as a sign of intermolecular cooperativity probably mediated via halogen bonds.

CdS-sensitized TiO2 nanocorals: hydrothermal synthesis, characterization, application.

PubMed

Mali, S S; Desai, S K; Dalavi, D S; Betty, C A; Bhosale, P N; Patil, P S

2011-10-01

Cadmium sulfide (CdS) nanoparticle-sensitized titanium oxide nanocorals (TNC) were synthesized using a two-step deposition process. The TiO(2) nanocorals were grown on the conducting glass substrates (FTO) using A hydrothermal process and CdS nanoparticles were loaded on TNC using successive ionic layer adsorption and reaction (SILAR) method. The TiO(2), CdS and TiO(2)-CdS samples were characterized by optical absorption, X-ray diffraction (XRD), FT-Raman, FT-IR, scanning electron microscopy (SEM) and contact angle. Further, their photoelectrochemical (PEC) performance was tested in NaOH, Na(2)S-NaOH-S and Na(2)S electrolytes, respectively. When CdS nanoparticles are coated on TNCs, the optical absorption is found to be enhanced and band edge is red-shifted towards visible region. The TiO(2)-CdS sample exhibits improved photoelectrochemical (PEC) performance with maximum short circuit current of (J(sc)) 1.04 mA cm(-2). After applying these TiO(2)-CdS electrodes in photovoltaic cells, the photocurrent was found to be enhanced by 2.7 and 32.5 times, as compared with those of bare CdS and TiO(2) nanocorals films electrodes respectively. Also, the power conversion efficiency of TiO(2)-CdS electrodes is 0.72%, which is enhanced by about 16 and 29 times for TiO(2), CdS samples. This journal is © The Royal Society of Chemistry and Owner Societies 2011

Properties of fluorosulfate-based ionic liquids and geometries of (FO2SOH)OSO2F- and (FO2SOH)2O2SOF-.

PubMed

Enomoto, Takeshi; Matsumoto, Kazuhiko; Hagiwara, Rika

2011-12-14

A room temperature ionic liquid (IL) based on the fluorosulfate anion (SO(3)F(-)) has been synthesized by the reaction of 1-ethyl-3-methylimidazolium (EMIm(+)) chloride and fluorosulfuric acid (HOSO(2)F). The viscosity, ionic conductivity, and electrochemical window of EMImSO(3)F at 25 °C are 46.6 mPa s, 10.8 mS cm(-1), and 4.3 V, respectively. According to a solvatochromic measurement using ILs, there is a trend in the donor ability of fluoro- and oxofluoroanions, PF(6)(-) < BF(4)(-) < N(SO(2)CF(3))(2)(-) < SO(3)CF(3)(-) < SO(3)F(-) < PO(2)F(2)(-), which is explained by the atomic charges obtained from quantum mechanical calculations. The 1 : 2 and 1 : 3 stoichiometric reactions of EMImCl and HOSO(2)F give EMIm(FO(2)SOH)OSO(2)F and EMIm(FO(2)SOH)(2)O(2)SOF, respectively. Both the salts are liquid at room temperature without a HOSO(2)F dissociation pressure (< 1 Pa) and have low viscosity and high ionic conductivity (9.2 mPa s and 30.8 mS cm(-1) for EMIm(FO(2)SOH)OSO(2)F and 5.1 mPa s and 43.2 mS cm(-1) for EMIm(FO(2)SOH)(2)O(2)SOF). The vibrational modes and bonding properties of these anionic species are discussed with the aid of quantum mechanical calculations. The (FO(2)SOH)OSO(2)F(-) anion in EMIm(FO(2)SOH)OSO(2)F does not have an inversion centre, which stands in contrast to the one with an inversion centre (e.g. observed in solid Cs(FO(2)SOH)OSO(2)F). The (FO(2)SOH)(2)O(2)SOF(-) anion in EMIm(FO(2)SOH)(2)O(2)SOF is characterized by vibrational spectroscopy under C(s) symmetry.

Functional Characterization of a Robust Marine Microbial Esterase and Its Utilization in the Stereo-Selective Preparation of Ethyl (S)-3-Hydroxybutyrate.

PubMed

Wang, Yilong; Zhang, Yun; Hu, Yunfeng

2016-11-01

One novel microbial esterase PHE21 was cloned from the genome of Pseudomonas oryzihabitans HUP022 identified from the deep sea of the Western Pacific. PHE21 was heterologously expressed and functionally characterized to be a robust esterase which behaved high resistance to various metal ions, organic solvents, surfactants, and NaCl. Despite the fact that the two enantiomers of ethyl 3-hydroxybutyrate were hard to be enzymatically resolved before, we successfully resolved racemic ethyl 3-hydroxybutyrate through direct hydrolysis reactions and generated chiral ethyl (S)-3-hydroxybutyrate using esterase PHE21. After process optimization, the enantiomeric excess, the conversion rate, and the yield of desired product ethyl (S)-3-hydroxybutyrate could reach 99, 65, and 87 %, respectively. PHE21 is a novel marine microbial esterase with great potential in asymmetric synthesis as well as in other industries.

Attapulgite-CeO2/MoS2 ternary nanocomposite for photocatalytic oxidative desulfurization

NASA Astrophysics Data System (ADS)

Li, Xiazhang; Zhang, Zuosong; Yao, Chao; Lu, Xiaowang; Zhao, Xiaobing; Ni, Chaoying

2016-02-01

Novel attapulgite(ATP)-CeO2/MoS2 ternary nanocomposites were synthesized by microwave assisted assembly method. The structures of the nanocomposites were characterized by XRD, FT-IR, UV-vis, XPS and in situ TEM. The photocatalytic activities of ATP-CeO2/MoS2 composites were investigated by degradating dibenzothiophene (DBT) in gasoline under visible light irradiation. The effect of the mass ratio of CeO2 to MoS2 on photocatalytic activity was investigated. The results indicate that the three-dimensional network structure is firmly constructed by ATP skeleton, CeO2 particles and MoS2 nanosheet which effectively increase the surface area of the composites and promote the separation of electrons and holes by resulting electronic transmission channels of multi-channel in space. The degradation rate of DBT can reach 95% under 3 h irradiation when the mass ratio of CeO2/MoS2 is 4/10. A plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite is put forward.

Scalable fabrication of SnO2 thin films sensitized with CuO islands for enhanced H2S gas sensing performance

NASA Astrophysics Data System (ADS)

Van Toan, Nguyen; Chien, Nguyen Viet; Van Duy, Nguyen; Vuong, Dang Duc; Lam, Nguyen Huu; Hoa, Nguyen Duc; Van Hieu, Nguyen; Chien, Nguyen Duc

2015-01-01

The detection of H2S, an important gaseous molecule that has been recently marked as a highly toxic environmental pollutant, has attracted increasing attention. We fabricate a wafer-scale SnO2 thin film sensitized with CuO islands using microelectronic technology for the improved detection of the highly toxic H2S gas. The SnO2-CuO island sensor exhibits significantly enhanced H2S gas response and reduced operating temperature. The thickness of CuO islands strongly influences H2S sensing characteristics, and the highest H2S gas response is observed with 20 nm-thick CuO islands. The response value (Ra/Rg) of the SnO2-CuO island sensor to 5 ppm H2S is as high as 128 at 200 °C and increases nearly 55-fold compared with that of the bare SnO2 thin film sensor. Meanwhile, the response of the SnO2-CuO island sensor to H2 (250 ppm), NH3 (250 ppm), CO (250 ppm), and LPG (1000 ppm) are low (1.3-2.5). The enhanced gas response and selectivity of the SnO2-CuO island sensor to H2S gas is explained by the sensitizing effect of CuO islands and the extension of electron depletion regions because of the formation of p-n junctions.

Evaluation of the DNA damaging potential of cannabis cigarette smoke by the determination of acetaldehyde derived N2-ethyl-2'-deoxyguanosine adducts.

PubMed

Singh, Rajinder; Sandhu, Jatinderpal; Kaur, Balvinder; Juren, Tina; Steward, William P; Segerbäck, Dan; Farmer, Peter B

2009-06-01

Acetaldehyde is an ubiquitous genotoxic compound that has been classified as a possible carcinogen to humans. It can react with DNA to form primarily a Schiff base N(2)-ethylidene-2'-deoxyguanosine (N(2)-ethylidene-dG) adduct. An online column-switching valve liquid chromatography tandem mass spectrometry (LC-MS/MS) selected reaction monitoring (SRM) method was developed for the determination of N(2)-ethylidene-dG adducts in DNA following reduction with sodium cyanoborohydride (NaBH(3)CN) to the chemically stable N(2)-ethyl-2'-deoxyguanosine (N(2)-ethyl-dG) adduct. Accurate quantitation of the adduct was obtained by the addition of the [(15)N(5)]N(2)-ethyl-dG stable isotope-labeled internal standard prior to enzymatic hydrolysis of the DNA samples to 2'-deoxynucleosides with the incorporation of NaBH(3)CN in the DNA hydrolysis buffer. The method required 50 microg of hydrolyzed DNA on column for the analysis, and the limit of detection for N(2)-ethyl-dG was 2.0 fmol. The analysis of calf thymus DNA treated in vitro with acetaldehyde (ranging from 0.5 to 100 mM) or with the smoke generated from 1, 5, and 10 cannabis cigarettes showed linear dose-dependent increases in the level of N(2)-ethyl-dG adducts (r = 0.954 and r = 0.999, respectively). Similar levels (332.8 +/- 21.9 vs 348.4 +/- 19.1 adducts per 10(8) 2'-deoxynucleosides) of N(2)-ethyl-dG adducts were detected following the exposure of calf thymus DNA to 10 tobacco or 10 cannabis cigarettes. No significant difference was found in the levels of N(2)-ethyl-dG adducts in human lung DNA obtained from nonsmokers (n = 4) and smokers (n = 4) with the average level observed as 13.3 +/- 0.7 adducts per 10(8) 2'-deoxynucleosides. No N(2)-ethyl-dG adducts were detected in any of the DNA samples following analysis with the omission of NaBH(3)CN from the DNA hydrolysis buffer. In conclusion, these results provide evidence for the DNA damaging potential of cannabis smoke, implying that the consumption of cannabis

Etude des mécanismes d'ionisation de H{2}O par interaction He^{*}(2 ^1S, 2 ^3S)/Ne^{*}(^3P{0}, ^3P{2})+H{2}O

NASA Astrophysics Data System (ADS)

Le Nadan, André; Sinou, Guillaume; Tuffin, Firmin

1993-06-01

Experimental observations of Penning ionisation of H{2}O by the helium metastables 21S and 23S and by the neon metastables ^3P{0} and ^3P{2} are reported. The kinetic energies of the ions created during the collision process (both parent and fragment) are analysed. Certain particularities of the experimental results are explained by involving the hypothesis of transfers of vibrational energy to kinetic energy. Furthermore, the forms of the energy distributions of the fragment ions are explained by th predissociation of the ^2B{2} state of H{2}O+. Nous avons étudié l'ionisation Penning de H{2}O par des métastables 21S et 23S de l'hélium, ainsi que ^3P{0} et ^3P{2} du néon. Nous avons analysé l'énergie cinétique des ions créés au cours de la collision (parents et fragments). Afin d'interpréter certaines particularités expérimentales, l'hypothèse de transferts d'énergie de vibration en énergie cinétique est proposées. Par ailleurs, les caractéristiques des distributions en énergie des ions fragments sont expliquées par la prédissociation de l'état ^2B{2} de H{2}O+.

Photodegradation of 4-tert-butylphenol in aqueous solution by UV-C, UV/H2O2 and UV/S2O8(2-) system.

PubMed

Wu, Yanlin; Zhu, Xiufen; Chen, Hongche; Dong, Wenbo; Zhao, Jianfu

2016-01-01

The photolytic degradation of 4-tert-butylphenol (4-t-BP) in aqueous solution was investigated using three kinds of systems: UV-C directly photodegradation system, UV/H2O2 and UV/S2O8(2-) system. Under experimental conditions, the degradation rate of 4-t-BP was in the order: UV/S2O8(2-) > UV/H2O2 > UV-C. The reaction kinetics of UV/S2O8(2-) system were thoroughly investigated. The increase of S2O8(2-) concentration enhanced the 4-t-BP degradation rate, which was inhibited when the concentration of S2O8(2-) exceeded 4.0 mM. The highest efficacy in 4-t-BP degradation was obtained at pH 6.5. The oxidation rate of 4-t-BP could be accelerated by increasing the reaction temperature and irradiation intensity. The highest rate constant (kobs = 8.4 × 10(-2) min(-1)) was acquired when the reaction temperature was 45 °C. The irradiation intensity was measured by irradiation distance, and the optimum irradiation distance was 10 cm. Moreover, the preliminary mechanism of 4-t-BP degradation was studied. The bond scission of the 4-t-BP molecule occurred by the oxidation of SO4(•-), which dimerized and formed two main primary products. Under the conditions of room temperature (25 °C ± 1 °C) and low concentration of K2S2O8 (0.5 mM), 35.4% of total organic carbon (TOC) was removed after 8.5-h irradiation. The results showed that UV/S2O8(2-) system was effective for the degradation of 4-t-BP.

SO2 Solvation in the 1-Ethyl-3-Methylimidazolium Thiocyanate Ionic Liquid by Incorporation into the Extended Cation-Anion Network.

PubMed

Firaha, Dzmitry S; Kavalchuk, Mikhail; Kirchner, Barbara

We have carried out an ab initio molecular dynamics study on the sulfur dioxide (SO 2 ) solvation in 1-ethyl-3-methylimidazolium thiocyanate for which we have observed that both cations and anions play an essential role in the solvation of SO 2 . Whereas, the anions tend to form a thiocyanate- and much less often an isothiocyanate-SO 2 adduct, the cations create a "cage" around SO 2 with those groups of atoms that donate weak interactions like the alkyl hydrogen atoms as well as the heavy atoms of the [Formula: see text]-system. Despite these similarities between the solvation of SO 2 and CO 2 in ionic liquids, an essential difference was observed with respect to the acidic protons. Whereas CO 2 avoids accepting hydrogen bonds form the acidic hydrogen atoms of the cations, SO 2 can from O(SO 2 )-H(cation) hydrogen bonds and thus together with the strong anion-adduct it actively integrates in the hydrogen bond network of this particular ionic liquid. The fact that SO 2 acts in this way was termed a linker effect by us, because the SO 2 can be situated between cation and anion operating as a linker between them. The particular contacts are the H(cation)[Formula: see text]O(SO 2 ) hydrogen bond and a S(anion)-S(SO 2 ) sulfur bridge. Clearly, this observation provides a possible explanation for the question of why the SO 2 solubility in these ionic liquids is so high.

The hydrogen bonding and hydration of 2'-OH in adenosine and adenosine 3'-ethyl phosphate.

PubMed

Acharya, Parag; Chattopadhyaya, Jyoti

2002-03-22

The 2'-OH group has major structural implications in the recognition, processing, and catalytic properties of RNA. We report here intra- and intermolecular H-bonding of 2'-OH in adenosine 3'-ethyl phosphate (1), 3'-deoxyadenosine (2), and adenosine (3) by both temperature- and concentration-dependent NMR studies, as well as by detailed endo ((3)J(H,H)) and exocyclic ((3)J(H,OH)) coupling constant analyses. We have also examined the nature of hydration and exchange processes of 2'-OH with water by a combination of NOESY and ROESY experiments in DMSO-d(6) containing 2 mol % HOD. The NMR-constrained molecular modeling (by molecular mechanics as well as by ab initio methods both in the gas and solution phase) has been used to characterize the energy minima among the four alternative dihedrals possible from the solution of the Karplus equation for (3)J(H2',OH) and (3)J(H3',OH) to delineate the preferred orientation of 2'-O-H proton in 1 and 2 as well as for 2'/3'-O-H protons in 3. The NMR line shape analysis of 2'-OH gave the DeltaG(H-bond)(298K) of 7.5 kJ mol(-1) for 1 and 8.4 kJ mol(-1) for 3; similar analyses of the methylene protons of 3'-ethyl phosphate moiety in 1 also gave comparable DeltaG(H-bond)(298K) of 7.3 kJ mol(-1). The donor nature of the 2'-OH in the intramolecular H-bonding in 3 is evident from its relatively reduced flexibility [-TDeltaS++](2'-OH) = -17.9(+/-0.5) kJ mol(-1)] because of the loss of conformational freedom owing to the intramolecular 2'O-H...O3' H-bonding, compared to the acceptor 3'-OH in 3 [-TDeltaS++](3'-OH) = -19.8 (+/- 0.6) kJ mol(-1)] at 298 K. The presence of intramolecular 2'-OH...O3' H-bonding in 3 is also corroborated by the existence of weak long-range (4)J(H2',OH3') in 3 (i.e., W conformation of H2'-C2'-C3'-O3'-H) as well as by (3)J(H,OH) dependent orientation of the 2'- and 3'-OH groups. The ROESY spectra for 1 and 3 at 308 K, in DMSO-d(6), show a clear positive ROE contact of both 2'- and 3'-OH with water. The presence of a

21 CFR 184.1293 - Ethyl alcohol.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl alcohol. 184.1293 Section 184.1293 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH. (b...

21 CFR 184.1293 - Ethyl alcohol.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH. (b...

Crystal structure of bis­(ethyl­enedi­thio)­tetra­thia­fulvalenium μ2-acetato-bis­[tri­bromido­rhenate(III)] 1,1,2-tri­chloro­ethane hemisolvate

PubMed Central

Golichenko, Alexander A.; Kravchenko, Andrey V.; Omelchenko, Irina V.; Chudak, Denis M.; Starodub, Vladimir A.; Barszcz, Boleslaw; Shtemenko, Alexander V.

2016-01-01

The asymmetric unit of the title salt, (C10H8S8)[Re2Br6(CH3COO)]·0.5C2H3Cl3, contains one bis­(ethyl­enedi­thio)­tetra­thia­fulvalene (ET) radical cation, one μ2-acetato-bis­[tri­bromido­rhenate(III)] anion and a 1,1,2-tri­chloro­ethane mol­ecule with half-occupancy disordered about a twofold rotation axis. The tetra­thia­fulvalene fragment adopts an almost planar configuration typical of the ET radical cation. The C atoms of both ethyl­enedi­thio fragments in the cation are disordered over two orientations with occupancy factors 0.65:0.35 and 0.77:0.23. In the anion, six Br atoms and a μ2-acetate ligand form a strongly distorted cubic O2Br6 coordination polyhedron around the Re2 dinuclear centre. In the crystal, centrosymmetrically related ET cations and Re2O2Br6 anions are linked into dimers by π–π stacking inter­actions [centroid-to-centroid distance = 3.826 (8) Å] and by pairs of additional Re⋯Br contacts [3.131 (3) Å], respectively. The dimers are further packed into a three-dimensional network by non-directional inter­ionic electrostatic forces and by C—H⋯Br and C—H⋯S hydrogen bonds. The disordered 1,1,2-tri­chloro­ethane mol­ecules occupy solvent-accessible channels along the b axis. PMID:27308025

Screen-printed SnO2/CNT quasi-solid-state gel-electrolyte supercapacitor

NASA Astrophysics Data System (ADS)

Kuok, Fei-Hong; Liao, Chen-Yu; Chen, Chieh-Wen; Hao, Yu-Chuan; Yu, Ing-Song; Chen, Jian-Zhang

2017-11-01

This study investigates a quasi-solid-state gel-electrolyte supercapacitor fabricated with nanoporous SnO2/CNT nanocomposite electrodes and a polyvinyl alcohol/sulfuric acid (PVA/H2SO4) gel electrolyte. First, pastes containing SnO2 nanoparticles, CNTs, ethyl cellulose, and terpineol are screen-printed onto carbon cloth. A tube furnace is then used for calcining the SnO2/CNT electrodes on carbon cloth. After furnace-calcination, the wettability of SnO2/CNT significantly improved; furthermore, the XPS analysis shows that number of C-O bond and oxygen content significantly decrease after furnace-calcination owing to the burnout of the ethyl cellulose by the furnace calcination processes. The furnace-calcined SnO2/CNT electrodes sandwich the PVA/H2SO4 gel electrolyte to form a supercapacitor. The fabricated supercapacitor exhibits an areal capacitance of 5.61 mF cm-2 when flat and 5.68 mF cm-2 under bending with a bending radius (R) of 1.0 cm. After a 1000 cycle stability test, the capacitance retention rates of the supercapacitor are 96% and 97% when flat and under bending (R  =  1.0 cm), respectively.

40 CFR 180.1323 - Ethyl-2E,4Z-decadienoate (Pear Ester); exemption from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Ethyl-2E,4Z-decadienoate (Pear Ester... RESIDUES IN FOOD Exemptions From Tolerances § 180.1323 Ethyl-2E,4Z-decadienoate (Pear Ester); exemption... for residues of the biochemical pesticide, ethyl-2E,4Z-decadienoate (pear ester), in or on all food...

Fabrication of MgFe2O4/MoS2 Heterostructure Nanowires for Photoelectrochemical Catalysis.

PubMed

Fan, Weiqiang; Li, Meng; Bai, Hongye; Xu, Dongbo; Chen, Chao; Li, Chunfa; Ge, Yilin; Shi, Weidong

2016-02-16

A novel one-dimensional MgFe2O4/MoS2 heterostructure has been successfully designed and fabricated. The bare MgFe2O4 was obtained as uniform nanowires through electrospinning, and MoS2 thin film appeared on the surface of MgFe2O4 after further chemical vapor deposition. The structure of the MgFe2O4/MoS2 heterostructure was systematic investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectrometry (XPS), and Raman spectra. According to electrochemical impedance spectroscopy (EIS) results, the MgFe2O4/MoS2 heterostructure showed a lower charge-transfer resistance compared with bare MgFe2O4, which indicated that the MoS2 played an important role in the enhancement of electron/hole mobility. MgFe2O4/MoS2 heterostructure can efficiently degrade tetracycline (TC), since the superoxide free-radical can be produced by sample under illumination due to the active species trapping and electron spin resonance (ESR) measurement, and the optimal photoelectrochemical degradation rate of TC can be achieved up to 92% (radiation intensity: 47 mW/cm(2), 2 h). Taking account of its unique semiconductor band gap structure, MgFe2O4/MoS2 can also be used as an photoelectrochemical anode for hydrogen production by water splitting, and the hydrogen production rate of MgFe2O4/MoS2 was 5.8 mmol/h·m(2) (radiation intensity: 47 mW/cm(2)), which is about 1.7 times that of MgFe2O4.

Cytotoxicity of copper(II)-complexes with some S-alkyl derivatives of thiosalicylic acid. Crystal structure of the binuclear copper(II)-complex with S-ethyl derivative of thiosalicylic acid

NASA Astrophysics Data System (ADS)

Nikolić, Miloš V.; Mijajlović, Marina Ž.; Jevtić, Verica V.; Ratković, Zoran R.; Novaković, Slađana B.; Bogdanović, Goran A.; Milovanović, Jelena; Arsenijević, Aleksandar; Stojanović, Bojana; Trifunović, Srećko R.; Radić, Gordana P.

2016-07-01

The spectroscopically predicted structure of the obtained copper(II)-complex with S-ethyl derivative of thiosalicylic acid was confirmed by X-ray structural study and compared to previously reported crystal structure of the Cu complex with S-methyl derivative. Single crystals suitable for X-ray measurements were obtained by slow crystallization from a water solution. Cytotoxic effects of S-alkyl (R = benzyl (L1), methyl (L2), ethyl (L3), propyl (L4) and butyl (L5)) derivatives of thiosalicylic acid and the corresponding binuclear copper(II)-complexes on murine colon carcinoma cell lines, CT26 and CT26.CL25 and human colon carcinoma cell line HCT-116 were reported here. The analysis of cancer cell viability showed that all the tested complexes had low cytotoxic effect on murine colon carcinoma cell lines, but several times higher cytotoxicity on normal human colon carcinoma cells.

[Complex application 2-ethyl-6-methyl-3-hydroxypyridine-succinate and vinpocetine in cerebrovascular disorder.

PubMed

Solovyeva, E Yu; Karneev, A N; Chekanov, A V; Baranova, O A; Choi, I V

Developing brain ischemia due to cerebral vascularization leads to disruption of brain metabolism. Chronic cerebral hypoperfusion leads to irreversible brain damage and plays an important role in the development of some types of dementia. Early use of antioxidants such as ethyl ether apovincamine acid (vinpocetine) and 2-ethyl-6-methyl-3-hydroxypyridine-succinate in the treatment of this pathology is seen as a real pathogenetically based method of correction of cerebral metabolism with cerebral vascular disorders, demonstrating the increase in cerebral blood flow and also neuroprotective effects. Clinical studies and studies on biological models show that the main mechanisms of action of vinpocetine and 2-ethyl-6-methyl-3-hydroxypyridine-succinate, although have a similar focus, but implementing neuroprotective and nootropic effects via various links in the pathogenesis of ischemic brain damage.

Environmental Fate of Organophosphorus Compounds Related to Chemical Weapons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davisson, M L; Love, A H; Vance, A

2005-02-08

Man-made organophosphorus compounds have been widely distributed throughout our environment as pesticides since their development during and after WWII. Many important studies have documented their relative persistence and toxicity. Development and use of some organophosphorus compounds as nerve agents gave rise to a separate but parallel effort to understand environmental persistence. In this latter case, the experiments have focused mainly on evaporation rates and first-order reaction kinetics. However, because organophosphorus compounds are easily polarized, the ionic content of a surrounding media directly factors into these reaction rates, but limited work in this regard has been done under environmentally relevant conditions.more » Furthermore, limited experiments investigating persistence of these agents on soil has resulted in widely varying degradation rates. Not surprisingly, no studies have investigated affinities of organophosphorus nerve agents to mineral or organic matter typically found in soil. As a result, we initiated laboratory experiments on dilute concentrations of nerve agent O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX) to quantify persistence in simulated environmental aqueous conditions. A quantitative analytical method was developed for VX and its degradation products using High Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (HPLC-ESI-MS). VX hydrolysis rate is known to have a pH-dependency, however, the type of buffer and the relative proportion of different nucleophiles in solution significantly affect the overall rate and mechanism of degradation. For example, dissolved carbonate, a weak nucleophile dominating natural water, yielded pseudo-first order rate constants of {approx} 8 x 10{sup -3}/hr at pH 5 and 2 x 10{sup -2}/hr at pH 11. This small pH-dependent variation departs significantly from widely accepted rates at this pH range (4 x 10{sup -4}/hr to 8 x 10{sup -2}/hr) that were

Evaluation of Chemical Warfare Agent Wipe Sampling ...

EPA Pesticide Factsheets

Report This investigation tested specific (CWAs), including sarin (GB), soman (GD), cyclosarin (GF), sulfur mustard (HD), and O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothioate (VX) on the non-ideal (e.g., porous and permeable) surfaces of drywall, vinyl tile, wood, laminate, and coated glass. Pesticides (diazinon and malathion) were used so that a comparison is possible with existing literature data (1). Experiments included testing with coupons having surface areas of 10 cm2 and 100 cm2. The 10-cm2 coupons were of a size that could easily be extracted in a 2 oz jar (to provide comparative data for CWA recoveries generated by direct extraction) and the 100-cm2 coupons better represented the area of a surface that might typically be sampled by wipe extraction. In addition, CWA, at a normalized surface concentration of 0.1 µg per cm2 surface area, were spiked on coupons of the tested surfaces. Wipes were wetted with either dichloromethane (DCM) or isopropanol (IPA) before sampling for CWA. Experimental parameters include multiple wipe types, porous/permeable surfaces, coupon surface area, solvent used to wet the wipe (i.e., wetting solvent), and the utility of VX-d14 as an extracted internal standard.

The dissociative recombination of O2(+) - The quantum yield of O(1S) and O(1D)

NASA Technical Reports Server (NTRS)

Abreu, V. J.; Solomon, S. C.; Sharp, W. E.; Hays, P. B.

1983-01-01

Data from the visible airglow experiment on the Atmosphere Explorer-E satellite have been used to determine the quantum yield of O(1S) and O(1D) from the dissociative recombination of O2(+). A range of values between 0.09 and 0.23 has been obtained for the quantum yield of O(1S). It is shown that the quantum yield of O(1S) depends on the ratio of electron density to atomic oxygen density. This suggests that the quantum yield of O(1S) may depend on the degree of vibrational excitation of the recombining O2(+). The quantum yield of O(1D) has been measured to be 1.23 + or - 0.42, with no dependence on the electron-oxygen ratio.

Diethyl 2,2′-(ethane-1,2-diyldi­oxy)di­benzo­ate

PubMed Central

Shi, Huaduan; Qin, Haisha; Ma, Zhen

2014-01-01

The mol­ecular title compound, C20H22O6, was obtained by the reaction of ethyl 2-hy­droxy­benzoate with 1,2-di­chloro­ethane. The mol­ecule lies on a twofold rotation axis which passes through the middle of the central ethyl­ene bridge. This group exhibits a gauche conformation with the corresponding O—C—C—O torsion angle being 73.2 (2)°. The C atoms of the carboxyl group, the aryl and the O—CH2 group are coplanar, with an r.m.s. deviation of 0.01 Å. The two aryl rings form a dihedral angle of 67.94 (4)°. The ester ethyl group is disordered over two sets of sites with an occupancy ratio of 0.59 (2):0.41 (2). The crystal packing is dominated by van der Waals forces. PMID:24860360

Ethyl 2-[(carbamothioyl-amino)-imino]-propano-ate.

PubMed

Corrêa, Charlane C; Graúdo, José Eugênio J C; de Oliveira, Luiz Fernando C; de Almeida, Mauro V; Diniz, Renata

2011-08-01

The title compound, C(6)H(11)N(3)O(2)S, consists of a roughly planar mol-ecule (r.m.s deviation from planarity = 0.077 Å for the non-H atoms) and has the S atom in an anti position to the imine N atom. This N atom is the acceptor of a strongly bent inter-nal N-H⋯N hydrogen bond donated by the amino group. In the crystal, mol-ecules are arranged in undulating layers parallel to (010). The mol-ecules are linked via inter-molecular amino-carboxyl N-H⋯O hydrogen bonds, forming chains parallel to [001]. The chains are cross-linked by N(carbazone)-H⋯S and C-H⋯S inter-actions, forming infinite sheets.

TiO{sub 2} flower-like nanostructures decorated with CdS/PbS nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trenczek-Zajac, Anita, E-mail: anita.trenczek-zajac@agh.edu.pl; Kusior, Anna; Lacz, Agnieszka

Highlights: • TiO{sub 2} flower-like nanostructures were prepared with the use of Ti foil and 30% H{sub 2}O{sub 2}. • QDs of CdS and PbS were deposited using the SILAR method. • The SILAR method makes it possible to control the size of QDs. • Band gap energy of CdS was found to be 2.35 eV. • Sensitization of TiO{sub 2} with CdS or PbS improves the photoelectrochemical properties. - Abstract: Flower-like nanostructures of TiO{sub 2} were prepared by immersing Ti foil in 30% H{sub 2}O{sub 2} at 80 °C for times varying from 15 to 240 min. Upon annealingmore » at 450 °C in an Ar atmosphere, the received amorphous samples crystallized in an anatase structure with rutile as a minority phase. SEM images revealed that partially formed flowers were present at the surface of the prepared samples as early as after 15 min of immersion. The size of the individual flowers increased from 400–800 nm after 15 min of reaction to 2.5–6.0 μm after 240 min. It was also found that surface is very rough and surface development is considerable. After 45 min of immersion, the nanoflowers were sensitized with CdS and PbS quantum dots (QDs-CdS/QDs-PbS) deposited using the SILAR method from water- and methanol-based precursor solutions at different concentrations (0.001–0.1 M). QDs-CdS crystallized in the hawleyite structure, while QDs-PbS in the galena form. SEM analysis showed the tendency of quantum dots to agglomerate at high concentrations of the precursor in water-based solutions. QDs obtained from methanol-based solutions were uniformly distributed. The produced QDs-PbS were smaller than QDs-CdS. Based on the optical reflectance spectra, the band-gap energies of TiO{sub 2} nanostructures with and without QDs were calculated to be 3.32 eV for flower-like TiO{sub 2} nanostructures and 2.35 eV for QDs-CdS. The photoelectrochemical behaviour of nanoflowers was found to improve significantly after the deposition of QDs-CdS.« less

Enantioselective quantitation of the ecstasy compound (R)- and (S)-N-ethyl-3,4-methylenedioxyamphetamine and its major metabolites in human plasma and urine.

PubMed

Buechler, Jochen; Schwab, Matthias; Mikus, Gerd; Fischer, Beate; Hermle, Leo; Marx, Claudia; Grön, Georg; Spitzer, Manfred; Kovar, Karl Artur

2003-08-15

An enantioselective HPLC method has been developed and validated for the stereospecific analysis of N-ethyl-3,4-methylenedioxyamphetamine (MDE) and its major metabolites N-ethyl-4-hydroxy-3-methoxyamphetamine (HME) and 3,4-methylenedioxyamphetamine (MDA). These compounds have been analyzed both from human plasma and urine after administration of 70 mg pure MDE-hydrochloride enantiomers to four subjects. The samples were prepared by hydrolysis of the o-glucuronate and sulfate conjugates using beta-glucuronidase/arylsulfatase and solid-phase extraction with a cation-exchange phase. A chiral stationary protein phase (chiral-CBH) was used for the stereoselective determination of MDE, HME and MDA in a single HPLC run using sodium dihydrogenphosphate, ethylendiaminetetraacetic acid disodium salt and isopropanol as the mobile phase (pH 6.44) and fluorimetric detection (lambda(ex) 286 nm, lambda(em) 322 nm). Moreover, a suitable internal standard (N-ethyl-3,4-methylenedioxybenzylamine) was synthesized and qualified for quantitation purposes. The method showed high recovery rates (>95%) and limits of quantitation for MDE and MDA of 5 ng/ml and for HME of 10 ng/ml. The RSDs for all working ranges of MDE, MDA and HME in plasma and urine, respectively, were less than 1.5%. After validation of the analytical methods in plasma and urine samples pharmacokinetic parameters were calculated. The plasma concentrations of (R)-MDE exceeded those of the S-enantiomer (ratio R:S of the area under the curve, 3.1) and the plasma half time of (R)-MDE was longer than that of (S)-MDE (7.9 vs. 4.0 h). In contrast, the stereochemical disposition of the MDE metabolites HME and MDA was reversed. Concentrations of the (S)-metabolites in plasma of volunteers were much higher than those of the (R)-enantiomers.

3-(2-amino-ethyl)-5-[3-(4-butoxyl-phenyl)-propylidene]-thiazolidine-2,4-dione (K145) ameliorated dexamethasone induced hepatic gluconeogenesis through activation of Akt/FoxO1 pathway.

PubMed

Shi, Yanan; Qiao, Jiayun; Mu, Biao; Zuo, Bingfeng; Yuan, Jihong

2017-11-04

3-(2-amino-ethyl)-5-[3-(4-butoxyl-phenyl)-propylidene]-thiazolidine-2,4-dione (K145) is identified as a selective SphK2 inhibitor. It was previously reported as an anti-tumor agent, in this study we demonstrated that K145 was able to regulate hepatic gluconeogenesis and improve glucose intolerance in mice. C57BL/6 mice treated with dexamethasone injection were used as experimental animals, which exhibited impaired glucose tolerance and increased gluconeogenetic enzymes. After K145 treatment, we found that the impairment of glucose tolerance and gluconeogenetic genes mRNA expression were improved. Besides, both in vivo and in votro studies suggested that K145 stimulated insulin dependent Akt phosphorylation and subsequently activates FoxO1 phosphorylation therefore inhibited gluconeogenetic genes expression including PEPCK and G6pase. Our study figures out a potential extent increase the value of developing K145 as therapeutic candidate for diabetes. Copyright © 2017. Published by Elsevier Inc.

Biomonitoring of N-ethyl-2-pyrrolidone in automobile varnishers.

PubMed

Koslitz, Stephan; Meier, Swetlana; Schindler, Birgit Karin; Weiss, Tobias; Koch, Holger Martin; Brüning, Thomas; Käfferlein, Heiko Udo

2014-12-01

N-alkyl-2-pyrrolidones are important organic solvents for varnishes in industry. This study investigates exposure to N-ethyl-2-pyrrolidone (NEP) in varnishing of hard plastic components in an automobile plant. Two specific biomarkers of exposure, 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI), were analyzed in urine samples of 14 workers. For this purpose, pre-shift, post-shift and next day pre-shift urine samples were collected midweek. Twelve workers performed regular work tasks (loading, wiping and packing), whereas two workers performed special work tasks including cleaning the sprayer system with organic solvents containing N-alkyl-2-pyrrolidones. Spot urine samples of nine non-exposed persons of the same plant served as controls. Median post-shift urinary levels of workers with regular work tasks (5-HNEP: 0.15 mg/L; 2-HESI: 0.19 mg/L) were ∼5-fold higher compared to the controls (0.03 mg/L each). Continuously increasing metabolite levels, from pre-shift via post-shift to pre-shift samples of the following day, were observed in particular for the two workers with the special working tasks. Maximum levels were 31.01 mg/L (5-HNEP) and 8.45 mg/L (2-HESI). No clear trend was evident for workers with regular working tasks. In summary, we were able to show that workers can be exposed to NEP during varnishing tasks in the automobile industry. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

ZrO2/MoS2 heterojunction photocatalysts for efficient photocatalytic degradation of methyl orange

NASA Astrophysics Data System (ADS)

Prabhakar Vattikuti, Surya Veerendra; Byon, Chan; Reddy, Chandragiri Venkata

2016-10-01

We report a simple solution-chemistry approach for the synthesis of ZrO2/MoS2 hybrid photocatalysts, which contain MoS2 as a cocatalyst. The material is usually obtained by a wet chemical method using ZrO(NO3)2 or (NH4)6Mo7O24·4H2O and C8H6S as precursors. The structural features of obtained materials were characterized by X-ray diffraction (XRD), highresolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), thermal analysis (TG-DTA), N2 adsorption-desorption, and photoluminescence (PL). The influence on the photocatalytic activity of the MoS2 cocatalyst concentration with ZrO2 nanoparticles was studied. The MZr-2 hybrid sample had the highest photocatalytic activity for the degradation of methyl orange (MO), which was 8.45 times higher than that of pristine ZrO2 ascribed to high specific surface area and absorbance efficiency. Recycling experiments revealed that the reusability of the MZr-2 hybrid was due to the low photocorrosive effect and good catalytic stability. PL spectra confirmed the electronic interaction between ZrO2 and MoS2. The photoinduced electrons could be easily transferred from CB of ZrO2 to the MoS2 cocatalyst, which facilitate effective charge separation and enhanced the photocatalytic degradation in the UV region. A photocatalytic mechanism is proposed. It is believed that the ZrO2/MoS2 hybrid structure has promise as a photocatalyst with low cost and high efficiency for photoreactions.

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2'-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2'-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

Enhancement of photoelectrochemical activity of SnS thin-film photoelectrodes using TiO2, Nb2O5, and Ta2O5 metal oxide layers

NASA Astrophysics Data System (ADS)

Vequizo, Junie Jhon M.; Yokoyama, Masanori; Ichimura, Masaya; Yamakata, Akira

2016-06-01

Tin sulfide (SnS) fine photoelectrodes fabricated by three-step pulsed electrodeposition were active for H2 evolution. The incident-photon-conversion-efficiency increases from 900 nm and offers a good fit with the absorption spectrum. The activity was enhanced by 3.4, 3.0, and 1.8 times compared to bare SnS by loading Nb2O5, TiO2, and Ta2O5, respectively. Nb2O5 was most efficient because its conduction band is low enough to facilitate effective electron transfer from SnS; it also has sufficiently high potential for H2 evolution. The overall activity is determined by the competitive interfacial electron transfer between SnS/metal-oxide and metal-oxide/water. Therefore, constructing appropriate heterojunctions is necessary for further improving photoelectrochemical systems.

Obtaining electrostatically bound CdS-SiO2 aggregates from electrophoretic concentrates of CdS nanoparticles

NASA Astrophysics Data System (ADS)

Bulavchenko, A. I.; Sap'yanik, A. A.; Demidova, M. G.; Rakhmanova, M. I.; Popovetskii, P. S.

2015-05-01

Nonaqueous electrophoresis reveals that the electrokinetic potential of CdS nanoparticles increases slightly (85-120 mV) along with the concentration (0-5 × 10-3 M) of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in n-decane, while negatively charged SiO2 particles acquire positive charge (switching from -75 up to +135 mV). The energies of interparticle interactions in CdS-CdS and CdS-SiO2 systems are calculated from these parameters and the literature values of the Hamaker constants according to the Deryaguin-Landau-Verwey-Overbeek (DLVO) theory. It is concluded that the presence of a minimum (2.5 k B T) on the potential dependences of the CdS-SiO2 system indicates the formation of CdS-SiO2 aggregates electrostatically bound by heterocoagulation at low concentrations of AOT. The luminescent properties of the obtained ultrafine CdS-SiO2 powders depend on the CdS content.

Characterization of Meldrum's acid derivative 5-(5-Ethyl-1,3,4-thiadiazol-2-ylamino)methylene-2,2-dimethyl-1,3-dioxane-4,6-dione by Raman and FT-IR spectroscopy and DFT calculations

NASA Astrophysics Data System (ADS)

de Toledo, T. A.; da Silva, L. E.; Teixeira, A. M. R.; Freire, P. T. C.; Pizani, P. S.

2015-07-01

In this study, the structural and vibrational properties of Meldrum's acid derivative 5-(5-Ethyl-1,3,4-thiadiazol-2-ylamino)methylene-2,2-dimethyl-1,3-dioxane-4,6-dione, C11H13N3O4S were studied combining experimental techniques such as Raman and FT-IR spectroscopy and density functional theory (DFT) calculations. The Raman and FT-IR spectra were recorded at room conditions in the regions from 80 to 3400 cm-1 and 400 to 4000 cm-1, respectively. Vibrational wavenumbers were predicted using DFT calculations with the hybrid functional B3LYP and basis set 6-31G(d,p). A comparison between experimental and theoretical data is provided for the Raman and FT-IR spectra. The descriptions of the normal modes were carried by means of potential energy distribution (PED).

Physiological basis for isoxadifen-ethyl induction of nicosulfuron detoxification in maize hybrids.

PubMed

Sun, Lanlan; Wu, Renhai; Su, Wangcang; Gao, Zenggui; Lu, Chuantao

2017-01-01

Isoxadifen-ethyl can effectively alleviate nicosulfuron injury in the maize. However, the effects of safener isoxadifen-ethyl on detoxifying enzymes in maize is unknown. The individual and combined effects of the sulfonylurea herbicide nicosulfuron and the safener isoxadifen-ethyl on the growth and selected physiological processes of maize were evaluated. Bioassays showed that the EC50 values of nicosulfuron and nicosulfuron plus isoxadifen-ethyl for maize cultivar Zhengdan958 were 18.87 and 249.28 mg kg-1, respectively, and were 24.8 and 275.51 mg kg-1, respectively, for Zhenghuangnuo No. 2 cultivar. Evaluations of the target enzyme of acetolactate synthase showed that the I50 values of nicosulfuron and nicosulfuron plus isoxadifen-ethyl for the ALS of Zhengdan958 were 15.46 and 28.56 μmol L-1, respectively, and were 0.57 and 2.17 μmol L-1, respectively, for the acetolactate synthase of Zhenghuangnuo No. 2. The safener isoxadifen-ethyl significantly enhanced tolerance of maize to nicosulfuron. The enhanced tolerance of maize to nicosulfuron in the presence of the safener, coupled with the enhanced injury observed in the presence of piperonyl butoxide, 1-aminobenzotriazole, and malathion, suggested cytochrome P450 monooxygenases may be involved in metabolism of nicosulfuron. We proposed that isoxadifen-ethyl increases plant metabolism of nicosulfuron through non-P450-catalyzed routes or through P450 monooxygenases not inhibited by piperonyl butoxide, 1-aminobenzotriazole, and malathion. Isoxadifen-ethyl, at a rate of 33 mg kg-1, completely reversed the effects of all doses (37.5-300 mg kg-1) of nicosulfuron on both of the maize cultivars. When the two compounds were given simultaneously, isoxadifen-ethyl enhanced activity of glutathione S-transferases (GSTs) and acetolactate synthase activity in maize. The free acid 4,5-dihydro-5,5-diphenyl-1,2-oxazole-3-carboxylic was equally effective at inducing GSTs as the parent ester and appeared to be the active safener

Physiological basis for isoxadifen-ethyl induction of nicosulfuron detoxification in maize hybrids

PubMed Central

Sun, Lanlan; Wu, Renhai; Su, Wangcang; Gao, Zenggui; Lu, Chuantao

2017-01-01

Isoxadifen-ethyl can effectively alleviate nicosulfuron injury in the maize. However, the effects of safener isoxadifen-ethyl on detoxifying enzymes in maize is unknown. The individual and combined effects of the sulfonylurea herbicide nicosulfuron and the safener isoxadifen-ethyl on the growth and selected physiological processes of maize were evaluated. Bioassays showed that the EC50 values of nicosulfuron and nicosulfuron plus isoxadifen-ethyl for maize cultivar Zhengdan958 were 18.87 and 249.28 mg kg-1, respectively, and were 24.8 and 275.51 mg kg-1, respectively, for Zhenghuangnuo No. 2 cultivar. Evaluations of the target enzyme of acetolactate synthase showed that the I50 values of nicosulfuron and nicosulfuron plus isoxadifen-ethyl for the ALS of Zhengdan958 were 15.46 and 28.56 μmol L-1, respectively, and were 0.57 and 2.17 μmol L-1, respectively, for the acetolactate synthase of Zhenghuangnuo No. 2. The safener isoxadifen-ethyl significantly enhanced tolerance of maize to nicosulfuron. The enhanced tolerance of maize to nicosulfuron in the presence of the safener, coupled with the enhanced injury observed in the presence of piperonyl butoxide, 1-aminobenzotriazole, and malathion, suggested cytochrome P450 monooxygenases may be involved in metabolism of nicosulfuron. We proposed that isoxadifen-ethyl increases plant metabolism of nicosulfuron through non-P450-catalyzed routes or through P450 monooxygenases not inhibited by piperonyl butoxide, 1-aminobenzotriazole, and malathion. Isoxadifen-ethyl, at a rate of 33 mg kg-1, completely reversed the effects of all doses (37.5–300 mg kg-1) of nicosulfuron on both of the maize cultivars. When the two compounds were given simultaneously, isoxadifen-ethyl enhanced activity of glutathione S-transferases (GSTs) and acetolactate synthase activity in maize. The free acid 4,5-dihydro-5,5-diphenyl-1,2-oxazole-3-carboxylic was equally effective at inducing GSTs as the parent ester and appeared to be the active safener

Distinguishing tautomerism in the crystal structure of (Z)-N-(5-ethyl-2,3-di-hydro-1,3,4-thiadiazol-2-ylidene) -4-methylbenzenesulfonamide using DFT-D calculations and {sup 13}C solid-state NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xiaozhou; Bond, Andrew D.; Johansson, Kristoffer E.

2014-08-01

The crystal structure of (Z)-N-(5-ethyl-2,3-di-hydro-1,3,4-thiadiazol-2-ylidene) -4-methylbenzenesulfonamide contains an imine tautomer, rather than the previously reported amine tautomer. The tautomers can be distinguished using dispersion-corrected density functional theory calculations and by comparison of calculated and measured {sup 13}C solid-state NMR spectra. The crystal structure of the title compound, C{sub 11}H{sub 13}N{sub 3}O{sub 2}S{sub 2}, has been determined previously on the basis of refinement against laboratory powder X-ray diffraction (PXRD) data, supported by comparison of measured and calculated {sup 13}C solid-state NMR spectra [Hangan et al. (2010 ▶). Acta Cryst. B66, 615–621]. The mol@@ecule is tautomeric, and was reported as an aminemore » tautomer [systematic name: N-(5-ethyl-1,3,4-thia@@diazol-2-yl)-p-toluene@@sulfonamide], rather than the correct imine tautomer. The protonation site on the mol@@ecule’s 1,3,4-thia@@diazole ring is indicated by the inter@@molecular contacts in the crystal structure: N—H⋯O hydrogen bonds are established at the correct site, while the alternative protonation site does not establish any notable inter molecular inter@@actions. The two tautomers provide essentially identical Rietveld fits to laboratory PXRD data, and therefore they cannot be directly distinguished in this way. However, the correct tautomer can be distinguished from the incorrect one by previously reported qu@@anti@@tative criteria based on the extent of structural distortion on optimization of the crystal structure using dispersion-corrected density functional theory (DFT-D) calculations. Calculation of the {sup 13}C SS-NMR spectrum based on the correct imine tautomer also provides considerably better agreement with the measured {sup 13}C SS-NMR spectrum.« less

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

CdS Nanoparticle-Modified α-Fe2O3/TiO2 Nanorod Array Photoanode for Efficient Photoelectrochemical Water Oxidation.

PubMed

Yin, Ruiyang; Liu, Mingyang; Tang, Rui; Yin, Longwei

2017-09-02

In this work, we demonstrate a facile successive ionic layer adsorption and reaction process accompanied by hydrothermal method to synthesize CdS nanoparticle-modified α-Fe 2 O 3 /TiO 2 nanorod array for efficient photoelectrochemical (PEC) water oxidation. By integrating CdS/α-Fe 2 O 3 /TiO 2 ternary system, light absorption ability of the photoanode can be effectively improved with an obviously broadened optical-response to visible light region, greatly facilitates the separation of photogenerated carriers, giving rise to the enhancement of PEC water oxidation performance. Importantly, for the designed abnormal type-II heterostructure between Fe 2 O 3 /TiO 2 , the conduction band position of Fe 2 O 3 is higher than that of TiO 2 , the photogenerated electrons from Fe 2 O 3 will rapidly recombine with the photogenerated holes from TiO 2 , thus leads to an efficient separation of photogenerated electrons from Fe 2 O 3 /holes from TiO 2 at the Fe 2 O 3 /TiO 2 interface, greatly improving the separation efficiency of photogenerated holes within Fe 2 O 3 and enhances the photogenerated electron injection efficiency in TiO 2 . Working as the photoanodes of PEC water oxidation, CdS/α-Fe 2 O 3 /TiO 2 heterostucture electrode exhibits improved photocurrent density of 0.62 mA cm - 2 at 1.23 V vs. reversible hydrogen electrode (RHE) in alkaline electrolyte, with an obviously negatively shifted onset potential of 80 mV. This work provides promising methods to enhance the PEC water oxidation performance of the TiO 2 -based heterostructure photoanodes.

40 CFR 721.6120 - Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. 721.6120 Section 721.6120 Protection of Environment...-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. (a) Chemical substances and significant new uses...

40 CFR 721.6120 - Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. 721.6120 Section 721.6120 Protection of Environment...-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. (a) Chemical substances and significant new uses...

40 CFR 721.6120 - Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. 721.6120 Section 721.6120 Protection of Environment...-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. (a) Chemical substances and significant new uses...

40 CFR 721.6120 - Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. 721.6120 Section 721.6120 Protection of Environment...-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. (a) Chemical substances and significant new uses...

40 CFR 721.6120 - Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid, 1,2-eth-a-ne-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. 721.6120 Section 721.6120 Protection of Environment...-diyl tet-ra-kis(2-chloro-1-meth-yl-ethyl) ester. (a) Chemical substances and significant new uses...

Optical, electrical and dielectric properties of TiO2-SiO2 films prepared by a cost effective sol-gel process.

PubMed

Vishwas, M; Rao, K Narasimha; Gowda, K V Arjuna; Chakradhar, R P S

2011-12-01

Titanium dioxide (TiO(2)) and silicon dioxide (SiO(2)) thin films and their mixed films were synthesized by the sol-gel spin coating method using titanium tetra isopropoxide (TTIP) and tetra ethyl ortho silicate (TEOS) as the precursor materials for TiO(2) and SiO(2) respectively. The pure and composite films of TiO(2) and SiO(2) were deposited on glass and silicon substrates. The optical properties were studied for different compositions of TiO(2) and SiO(2) sols and the refractive index and optical band gap energies were estimated. MOS capacitors were fabricated using TiO(2) films on p-silicon (100) substrates. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics were studied and the electrical resistivity and dielectric constant were estimated for the films annealed at 200°C for their possible use in optoelectronic applications. Copyright © 2011 Elsevier B.V. All rights reserved.

Synthesis of Nanoscale CaO-Al2O3-SiO2-H2O and Na2O-Al2O3-SiO2-H2O Using the Hydrothermal Method and Their Characterization

PubMed Central

Yang, Jingbin; Li, Dongxu; Fang, Yuan

2017-01-01

C-A-S-H (CaO-Al2O3-SiO2-H2O) and N-A-S-H (Na2O-Al2O3-SiO2-H2O) have a wide range of chemical compositions and structures and are difficult to separate from alkali-activated materials. Therefore, it is difficult to analyze their microscopic properties directly. This paper reports research on the synthesis of C-A-S-H and N-A-S-H particles with an average particle size smaller than 300 nm by applying the hydrothermal method. The composition and microstructure of the products with different CaO(Na2O)/SiO2 ratios and curing conditions were characterized using XRD, the RIR method, FTIR, SEM, TEM, and laser particle size analysis. The results showed that the C-A-S-H system products with a low CaO/SiO2 ratio were mainly amorphous C-A-S-H gels. With an increase in the CaO/SiO2 ratio, an excess of Ca(OH)2 was observed at room temperature, while in a high-temperature reaction system, katoite, C4AcH11, and other crystallized products were observed. The katoite content was related to the curing temperature and the content of Ca(OH)2 and it tended to form at a high-temperature and high-calcium environment, and an increase in the temperature renders the C-A-S-H gels more compact. The main products of the N-A-S-H system at room temperature were amorphous N-A-S-H gels and a small amount of sodalite. An increase in the curing temperature promoted the formation of the crystalline products faujasite and zeolite-P. The crystallization products consisted of only zeolite-P in the high-temperature N-A-S-H system and its content were stable above 70%. An increase in the Na2O/SiO2 ratio resulted in more non-bridging oxygen and the TO4 was more isolated in the N-A-S-H structure. The composition and microstructure of the C-A-S-H and N-A-S-H system products synthesized by the hydrothermal method were closely related to the ratio of the raw materials and the curing conditions. The results of this study increase our understanding of the hydration products of alkali-activated materials. PMID

Sequence distribution of acetaldehyde-derived N2-ethyl-dG adducts along duplex DNA.

PubMed

Matter, Brock; Guza, Rebecca; Zhao, Jianwei; Li, Zhong-ze; Jones, Roger; Tretyakova, Natalia

2007-10-01

Acetaldehyde (AA) is the major metabolite of ethanol and may be responsible for an increased gastrointestinal cancer risk associated with alcohol beverage consumption. Furthermore, AA is one of the most abundant carcinogens in tobacco smoke and induces tumors of the respiratory tract in laboratory animals. AA binding to DNA induces Schiff base adducts at the exocyclic amino group of dG, N2-ethylidene-dG, which are reversible on the nucleoside level but can be stabilized by reduction to N2-ethyl-dG. Mutagenesis studies in the HPRT reporter gene and in the p53 tumor suppressor gene have revealed the ability of AA to induce G-->A transitions and A-->T transversions, as well as frameshift and splice mutations. AA-induced point mutations are most prominent at 5'-AGG-3' trinucleotides, possibly a result of sequence specific adduct formation, mispairing, and/or repair. However, DNA sequence preferences for the formation of acetaldehyde adducts have not been previously examined. In the present work, we employed a stable isotope labeling-HPLC-ESI+-MS/MS approach developed in our laboratory to analyze the distribution of acetaldehyde-derived N2-ethyl-dG adducts along double-stranded oligodeoxynucleotides representing two prominent lung cancer mutational "hotspots" and their surrounding DNA sequences. 1,7,NH 2-(15)N-2-(13)C-dG was placed at defined positions within DNA duplexes derived from the K-ras protooncogene and the p53 tumor suppressor gene, followed by AA treatment and NaBH 3CN reduction to convert N2-ethylidene-dG to N2-ethyl-dG. Capillary HPLC-ESI+-MS/MS was used to quantify N2-ethyl-dG adducts originating from the isotopically labeled and unlabeled guanine nucleobases and to map adduct formation along DNA duplexes. We found that the formation of N2-ethyl-dG adducts was only weakly affected by the local sequence context and was slightly increased in the presence of 5-methylcytosine within CG dinucleotides. These results are in contrast with sequence

Self-cleaning cotton functionalized with TiO2/SiO2: focus on the role of silica.

PubMed

Pakdel, Esfandiar; Daoud, Walid A

2013-07-01

This manuscript aims to investigate the functionalization of cotton fabrics with TiO2/SiO2. In this study, the sol-gel method was employed to prepare titania and silica sols and the functionalization was carried out using the dip-pad-dry-cure process. Titanium tetra isopropoxide (TTIP) and tetra ethyl orthosilicate (TEOS) were utilized as precursors of TiO2 and SiO2, respectively. TiO2/SiO2 composite sols were prepared in three different Ti:Si molar ratios of 1:0.43, 1:1, and 1:2.33. The self-cleaning property of cotton samples functionalized with TiO2/SiO2 was assessed based on the coffee stain removal capability and the decomposition rate of methylene blue under UV irradiation. FTIR study of the TiO2/SiO2 photocatalyst confirmed the existence of Si-O-Si and Ti-O-Si bonds. Scanning electron microscopy was employed to investigate the morphology of the functionalized cotton samples. The samples coated with TiO2/SiO2 showed greater ability of coffee stain removal and methylene blue degradation compared with samples functionalized with TiO2 demonstrating improved self-cleaning properties. The role of SiO2 in improving these properties is also discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

Thermospheric production of O(1S) by dissociative recombination of vibrationally excited O2(+)

NASA Technical Reports Server (NTRS)

Yee, Jeng-Hwa; Killeen, T. L.

1986-01-01

High spectral resolution line profiles at 5577 A of the nighttime, F-region O(1S) emission measured by the Fabry-Perot interferometer on board the Dynamics Explorer satellite are analyzed using a continuous O(1S) relaxation model. The model is an improvement over the previous model of Killeen and Hays (1981) in that energy loss via elastic collision is considered in addition to the single collision, excitation exchange thermalization process. The results show that the active channel for O(1S) production is capture into the 1Sigma(+)u repulsive state of O2 and that the main contributor to its production is the dissociative recombination of O2(+) ions in vibrational levels v = 1 and 2 in agreement with the quantal calculations of Guberman (1983).

A comparative investigation of Lu2SiO5:Ce and Gd2O2S:Eu powder scintillators for use in x-ray mammography detectors

NASA Astrophysics Data System (ADS)

Michail, C. M.; Fountos, G. P.; David, S. L.; Valais, I. G.; Toutountzis, A. E.; Kalyvas, N. E.; Kandarakis, I. S.; Panayiotakis, G. S.

2009-10-01

The dominant powder scintillator in most medical imaging modalities for decades has been Gd2O2S:Tb due to the very good intrinsic properties and overall efficiency. Apart from Gd2O2S:Tb, there are alternative powder phosphor scintillators such as Lu2SiO5:Ce and Gd2O2S:Eu that have been suggested for use in various medical imaging modalities. Gd2O2S:Eu emits red light and can be combined mainly with digital mammography detectors such as CCDs. Lu2SiO5:Ce emits blue light and can be combined with blue sensitivity films, photocathodes and some photodiodes. For the purposes of the present study, two scintillating screens, one from Lu2SiO5:Ce and the other from Gd2O2S:Eu powders, were prepared using the method of sedimentation. The screen coating thicknesses were 25.0 and 33.1 mg cm-2 respectively. The screens were investigated by evaluating the following parameters: the output signal, the modulation transfer function, the noise equivalent passband, the informational efficiency, the quantum detection efficiency and the zero-frequency detective quantum efficiency. Furthermore, the spectral compatibility of those materials with various optical detectors was determined. Results were compared to published data for the commercially employed 'Kodak Min-R film-screen system', based on a 31.7 mg cm-2 thick Gd2O2S:Tb phosphor. For Gd2O2S:Eu, MTF data were found comparable to those of Gd2O2S:Tb, while the MTF of Lu2SiO5:Ce was even higher resulting in better spatial resolution and image sharpness properties. On the other hand, Gd2O2S:Eu was found to exhibit higher output signal and zero-frequency detective quantum efficiency than Lu2SiO5:Ce.

Synthesis of fruity ethyl esters by acyl coenzyme A: alcohol acyltransferase and reverse esterase activities in Oenococcus oeni and Lactobacillus plantarum.

PubMed

Costello, P J; Siebert, T E; Solomon, M R; Bartowsky, E J

2013-03-01

To assess the abilities of commercial wine lactic acid bacteria (LAB) to synthesize potentially flavour active fatty acid ethyl esters and determine mechanisms involved in their production. Oenococcus oeni AWRI B551 produced significant levels of ethyl hexanoate and ethyl octanoate following growth in an ethanolic test medium, and ester formation generally increased with increasing pH (4.5 > 3.5), anaerobiosis and precursor supplementation. Cell-free extracts of commercial O. oeni strains and Lactobacillus plantarum AWRI B740 were also tested for ester-synthesizing capabilities in a phosphate buffer via: (i) acyl coenzyme A: alcohol acyltransferase (AcoAAAT) activity and (ii) reverse esterase activity. For both ester-synthesizing activities, strain-dependent variation was observed, with AcoAAAT activity generally greater than reverse esterase. Reverse esterase in O. oeni AWRI B551 also esterified 1-propanol to produce propyl octanoate, and deuterated substrates ([(2)H(6)]ethanol and [(2)H(15)]octanoic acid) to produce the fully deuterated ester, [(2)H(5)]ethyl [(2)H(15)]octanoate. Wine LAB exhibit ethyl ester-synthesizing capability and possess two different ester-synthesizing activities, one of which is associated with an acyl coenzyme A: alcohol acyltransferase. This study demonstrates that wine LAB exhibit enzyme activities that can augment the ethyl ester content of wine. This knowledge will facilitate greater control over the impacts of malolactic fermentation on the fruity sensory properties and quality of wine. © 2012 Australian Wine Research Institute © 2012 The Society for Applied Microbiology.

Enhanced photocatalytic activity and synthesis of ZnO nanorods/MoS2 composites

NASA Astrophysics Data System (ADS)

Li, Hui; Shen, Hao; Duan, Libing; Liu, Ruidi; Li, Qiang; Zhang, Qian; Zhao, Xiaoru

2018-05-01

A stable and recyclable organic degradation catalyst based on MoS2 functionalized ZnO nanorods was introduced. ZnO nanorods were synthesized on the glass substrates (2 cm*2 cm) by sol-gel method and hydrothermal method and functionalized with MoS2 via an argon flow annealing method. The structure and morphology of the as-prepared samples were characterized by XRD, SEM and TEM. Results showed that a small amount of MoS2 was successfully wrapped on the surfaces of ZnO nanorods. XPS analyses showed the existence of Zn-S between ZnO and MoS2, indicating that the MoS2 was combined with ZnO through chemical bonds and formed the ZnO/MoS2 heterostructure. PL results revealed that ZnO/MoS2 had lower fluorescence spectra indicating an electron transport channel between ZnO and MoS2 which separated electrons and holes. Photocatalytic experiment showed that ZnO/MoS2 composites showed a better photodegradation performance of Rhodamine B (RhB) after functionalized with MoS2 under the UV light irradiation which could be attributed to the separation and transfer of photogenerated electrons and holes between ZnO and MoS2. Meanwhile, the high active adsorption sites on the edges of MoS2 also accelerated the degradation process. Furthermore, the scavengers were used to investigate the major active species and results indicated that h+ was the major reactive species for the degradation.

A beta-keto ester as a novel, efficient, and versatile ligand for copper(I)-catalyzed C-N, C-O, and C-S coupling reactions.

PubMed

Lv, Xin; Bao, Weiliang

2007-05-11

Employing ethyl 2-oxocyclohexanecarboxylate as a novel, efficient, and versatile ligand, the copper-catalyzed coupling reactions of various N/O/S nucleophilic reagents with aryl halides could be successfully carried out under mild conditions. A variety of products including N-arylamides, N-arylimidazoles, aryl ethers, and aryl thioethers were synthesized in good to excellent yields.

Synthesis and characterization of physical properties of Gd2O2S:Pr3+ semi-nanoflower phosphor

NASA Astrophysics Data System (ADS)

Bagheri, A.; Rezaee Ebrahim Saraee, Kh.; Shakur, H. R.; Zamani Zeinali, H.

2016-05-01

Pure gadolinium oxysulfide phosphor (Gd2O2S) and trivalent praseodymium-doped gadolinium oxysulfide phosphor (Gd2O2S:Pr3+) scintillators with semi-nanoflower crystalline structures were successfully synthesized through a precipitation method and subsequent calcination treatment as a converter for X-ray imaging detectors. The characterization such as the crystal structures and nanostructure of Gd2O2S:Pr3+ scintillator measured by XRD and FeE-SEM experiment. The optical properties of Gd2O2S:Pr3+ scintillator were studied. Luminescence spectra of Gd2O2S:Pr3+ under 320 nm UV excitation show a green emission at near 511 nm corresponding to the 3P0-3H4 of Pr ions. After scintillation properties of synthesized Gd2O2S:Pr3+ scintillator investigated, Gd2O2S:Pr3+ scintillating film fabricated on a glass substrate by a sedimentation method. X-ray imaging of the fabricated scintillators confirmed that the Gd2O2S:Pr3+ scintillator could be used for radiography applications in which good spatial resolution is needed.

Quantum Dot Sensitized Solar Cells Based on TiO2/AgInS2

NASA Astrophysics Data System (ADS)

Pawar, Sachin A.; Jeong, Jae Pil; Patil, Dipali S.; More, Vivek M.; Lee, Rochelle S.; Shin, Jae Cheol; Choi, Won Jun

2018-05-01

Quantum dot heterojunctions with type-II band alignment can efficiently separate photogenerated electron-hole pairs and, hence, are useful for solar cell studies. In this study, a quantum dot sensitized solar cell (QDSSC) made of TiO2/AgInS2 is achieved to boost the photoconversion efficiency for the TiO2-based system by varying the AgInS2 layer's thickness. The TiO2 nanorods array film is prepared by using a simple hydrothermal technique. The formation of a AgInS2 QD-sensitized TiO2-nanorod photoelectrode is carried out by successive ionic layer adsorption and reaction (SILAR) technique. The effect of the QD layer on the performance of the solar cell is studied by varying the SILAR cycles of the QD coating. The synthesized electrode materials are characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, high resolution transmission electron microscopy and solar cell performances. The results indicate that the nanocrystals have effectively covered the outer surfaces of the TiO2 nanorods. The interfacial structure of quantum dots (QDs)/TiO2 is also investigated, and the growth interface is verified. A careful comparison between TiO2/AgInS2 sensitized cells reveals that the trasfer of electrons and hole proceeds efficiently, the recombination is suppressed for the optimum thickness of the QD layer and light from the entire visible spectrum is utilised. Under AM 1.5G illumination, a high photocurrent of 1.36 mAcm-2 with an improved power conversion efficiency of 0.48% is obtained. The solar cell properties of our photoanodes suggest that the TiO2 nanorod array films co-sensitized by AgInS2 nanoclusters have potential applications in solar cells.

Hydrogenated MoS2 QD-TiO2 heterojunction mediated efficient solar hydrogen production.

PubMed

Saha, Arka; Sinhamahapatra, Apurba; Kang, Tong-Hyun; Ghosh, Subhash C; Yu, Jong-Sung; Panda, Asit B

2017-11-09

Herein, we report the development of a hydrogenated MoS 2 QD-TiO 2 (HMT) heterojunction as an efficient photocatalytic system via a one-pot hydrothermal reaction followed by hydrogenation. This synthetic strategy facilitates the formation of MoS 2 QDs with an enhanced band gap and a proper heterojunction between them and TiO 2 , which accelerates charge transfer process. Hydrogenation leads to oxygen vacancies in TiO 2 , enhancing the visible light absorption capacity through narrowing its band gap, and sulfur vacancies in MoS 2 , which enhance the active sites for hydrogen adsorption. Due to the band gap reduction of hydrogenated TiO 2 and the band gap enhancement of the MoS 2 QDs, the energy states are rearranged to create a reverse movement of electrons and holes facilitated the charge transfer process which enhance life-time of photo-generated charges. The photocatalyst showed stable, efficient and exceptionally high noble metal free sunlight-induced hydrogen production with a maximum rate of 3.1 mmol g -1 h -1 . The developed synthetic strategy also provides flexibility towards the shape of the MoS 2 , e.g. QDs/single or few layers, on TiO 2 and offers the opportunity to design novel visible light active photocatalysts for different applications.

First-principles study of Mn-S codoped anatase TiO2

NASA Astrophysics Data System (ADS)

Li, Senlin; Huang, Jinliang; Ning, Xiangmei; Chen, Yongcha; Shi, Qingkui

2018-04-01

In this work, the CASTEP program in Materials Studio 2017 software package was applied to calculate the electronic structures and optical properties of pure anatase TiO2, S-doped, Mn-doped and Mn-S co-doped anatase TiO2 by GGA + U methods based on the density function theory (DFT). The results indicate that the lattice is distorted and the lattice constant is reduce due to doping. The doping also introduces impurity energy levels into the forbidden band. After substitution of Mn for Ti atom, band gap narrowing of anatase TiO2 is caused by the impurity energy levels appearance in the near Fermi surface, which are contributed by Mn-3d orbital, Ti-3d orbital and O-2p orbital hybridization. After substitution of S for O atom, band gap narrowing is creited with the shallow accepter level under the conduction hand of S-3p orbital. The Mn-S co-doped anatase TiO2 could be a potential candidate for a photocatalyst because of tis enhanced absorption ability of visible light. The results can well explain the immanent cause of a band gap narrowing as well as a red shift in the spectrum for doped anatase TiO2.

O(1S) from dissociative recombination of O2(+) - Nonthermal line profile measurements from Dynamics Explorer

NASA Technical Reports Server (NTRS)

Killeen, T. L.; Hays, P. B.

1983-01-01

The measurements reported were made of the O(1S) emission line profile at 5577 A at high spectral resolution with the Fabry-Perot interferometer on the Dynamics Explorer spacecraft. It is found that the line profile has marked nonthermal characteristics in the nightglow. A simple collisional relaxation model is used to analyze the nighttime emission line profiles, measured in the equatorial region. The branching ratio is inferred for the dissociative recombination of O2(+) leading to O(1S). The result reveals that the O(1S) + O(1D) channel is favored over the O(1S). The result reveals that the O(1S) + O(1D) channel is favored over the O(1S) + O(3P) channel by a factor of 4; this does not agree with the ratio reported by Hernandez (1971). It is noted, however, that the result is consistent with the active channel for O(1S) production being via the 1Sigma u + repulsive state of O2, as suggested by the theoretical calculations of Guberman (1983). In addition, a value is obtained for the excitation exchange cross section for O(1S).

Data on the effect of improved TiO2/FTO interface and Ni(OH)2 cocatalyst on the photoelectrochemical performances and stability of CdS cased ZnIn2S4/TiO2 heterojunction.

PubMed

Mahadik, Mahadeo A; Shinde, Pravin S; Lee, Hyun Hwi; Cho, Min; Jang, Jum Suk

2018-04-01

This data article presents the experimental evidences of the effect of TiO 2 -fluorine doped tin oxide interface annealing and Ni(OH) 2 cocatalysts on the photoelectrochemical, structural, morphological and optical properties of Ni(OH) 2 /CdS/ZnIn 2 S 4 /TiO 2 heterojunction. The Raman spectroscopy exhibits the sharp features of the rutile phase of TiO 2 and in agreement with the X-ray diffraction data. The band gap energy of the 500 °C sample was found to be 3.12 eV, further it was increased to 3.20, 3.22 eV for samples annealed at 600 and 700 °C respectively. The decrease in the band gap energy at 500 °C related to the oxygen vacancies and was analysed by photoluminescence spectroscopy analysis. The synthesis, characterization methods and other experimental details of TiO 2 based heterostructure are also provided. The presence of CdS and ZnIn 2 S 4 coating on surface of TiO 2 electrodes providing a high surface area, extended visible absorption and helps to improve the change separation. This data article contains data related to the research article entitled "Highly efficient and stable 3D Ni(OH) 2 /CdS/ZnIn 2 S 4 /TiO 2 heterojunction under solar light: Effect of an improved TiO 2 /FTO interface and cocatalyst" (Mahadik et al., 2017) [1].

Wavelength Effect on the Action of a N-Phenylimide S-23142 and a Diphenylether Acifluorfen-Ethyl in Cotyledons of Cucumber (Cucumis sativus L.) Seedlings 1

PubMed Central

Sato, Ryo; Nagano, Eiki; Oshio, Hiromichi; Kamoshita, Katsuzo; Furuya, Masaki

1987-01-01

Specific wavelengths of light required for expression of phytotoxic activity of S-23142 (N-[4-chloro-2-fluoro-5-propargyloxy]phenyl-3,4,5,6-tetra- hydrophthalimide) and acifluorfen-ethyl (ethyl-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitro benzoic acid) were determined in cotyledons of cucumber seedlings using the Okazaki Large Spectrograph. Leakage of amino acids from the cotyledons was measured as an indication of the phytotoxic activity. The wavelength effects showed common major peaks of activity at 550 and 650 nanometers and a minor peak at 450 nanometers for both herbicides, indicating a common primary photoreaction. Concomitant application of DCMU (3-[3,4-dichlorophenyl]-1,1-dimethylurea) with S-23142 had little influence on the effective wavelengths for S-23142 activity. Light of 450 and 650 nanometers was relatively less effective in achlorophyllous tissue grown in far red light than in green tissue. These results strongly suggest that the phytotoxic action of S-23142 and diphenylethers involves multiple photoreactions and that one of the photoreceptor pigments may be chlorophyll or its related pigment, although photosynthesis is not involved. PMID:16665819

The preparation and photocatalytic activity of CdS/(Cal-Ta2O5-SiO2) composite photocatalyst under visible light

NASA Astrophysics Data System (ADS)

Li, Juxia

2018-02-01

CdS/(Cal-Ta2O5-SiO2) composite photocatalyst has been successfully fabricated via wet chemistry method. Ta2O5-SiO2 with multi-step Ta2O5 deposition on SiO2 has more Ta2O5 on SiO2 to ensure the active sites. Trough multi-step calcination, Ta2O5 can load on SiO2 with uniform and stable, which make it have high photocatalytic activity. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance ultraviolet-visible spectroscopy (UV-vis) and photoluminescence spectroscopy (PL). Without any co-catalysts, the as-prepared CdS/(Cal-Ta2O5-SiO2) exhibited remarkable photocatalytic activity and recyclability both in the degradation of rhodamine B and in the hydrogen production from water splitting under visible light.

Enhanced H2S Sensing Performance of a p-type Semiconducting PdO-NiO Nanoscale Heteromixture

NASA Astrophysics Data System (ADS)

Balamurugan, C.; Jeong, Y. J.; Lee, D. W.

2017-10-01

Semiconducting nanocrystalline nickel oxide (NiO) and PdO-doped NiO heteromixture (2, 5 and 10 wt%) have been synthesized via a metal-citrate complex method. The obtained materials were further characterized using TG/DTA, FT-IR, UV-vis, XRD, XPS, BET/BJH, SEM and TEM analyses to determine their structural and morphological properties. The results indicated that the spherical, uniform PdO nanoparticles were densely deposited on the NiO surface mainly in diameters of 10-15 nm. Moreover, the existence of various defect states was also analyzed with the help of photoluminescence (PL) spectroscopy. The gas response characteristics of synthesized materials were evaluated in the presence and absence of toxic gases such as hydrogen sulfide (H2S), carbon monoxide (CO), liquid petroleum gas (LPG), and ethanol (C2H5OH). The experimental results revealed that the sensitivity and selectivity of the NiO-based sensor material are dependent on the weight% of PdO loading in the NiO nanopowder. Among the investigated compound, the 5 wt% PdO-doped NiO sensor material showed excellent sensitivity and selectivity to 100 ppm H2S with a fast response/recovery characteristics of 6 s and 10 s, respectively. Furthermore, the 5 wt% PdO-doped NiO based sensor showed a linear relationship between the different concentrations of H2S gas and a significantly higher response to H2S even at the low concentration of 20 ppm (43%) at 60 °C. The dominant H2S gas sensing mechanisms in the NiO and 5 wt% PdO-doped NiO nanomaterials are systematically discussed based on the obtained characterization results.

Optical transmission larger than 1 (T>1) through ZnS -SiO2/AgOx/ZnS-SiO2 sandwiched thin films

NASA Astrophysics Data System (ADS)

Wei, Jingsong; Xiao, Mufei

2006-09-01

Optical transmission through flat media should be smaller than 1. However, we have observed optical transmission up to T =1.18. The samples were ZnS -SiO2/AgOx/ZnS-SiO2 sandwiched thin films on glass substrate. The supertransmission could only be observed in the near field. We attribute the supertransmission to the lateral propagation relayed by the laser activated and decomposed Ag nanoparticles.

Reactivation and reuse of TiO2-SnS2 composite catalyst for solar-driven water treatment.

PubMed

Kovacic, Marin; Kopcic, Nina; Kusic, Hrvoje; Stangar, Urska Lavrencic; Dionysiou, Dionysios D; Bozic, Ana Loncaric

2018-01-01

One of the most important features of photocatalytic materials intended to be used for water treatment is their long-term stability. The study is focused on the application of thermal and chemical treatments for the reactivation of TiO 2 -SnS 2 composite photocatalyst, prepared by hydrothermal synthesis and immobilized on the glass support using titania/silica binder. Such a catalytic system was applied in solar-driven treatment, solar/TiO 2 -SnS 2 /H 2 O 2 , for the purification of water contaminated with diclofenac (DCF). The effectiveness of studied reactivation methods for retaining TiO 2 -SnS 2 activity in consecutive cycles was evaluated on basis of DCF removal and conversion, and TOC removal and mineralization of organic content. Besides these water quality parameters, biodegradability changes in DCF aqueous solution treated by solar/TiO 2 -SnS 2 /H 2 O 2 process using simply reused (air-dried) and thermally and chemically reactivated composite photocatalyst through six consecutive cycles were monitored. It was established that both thermal and chemical reactivation retain TiO 2 -SnS 2 activity in the second cycle of its reuse. However, both treatments caused the alteration in the TiO 2 -SnS 2 morphology due to the partial transformation of visible-active SnS 2 into non-active SnO 2 . Such alteration, repeated through consecutive reactivation and reuse, was reflected through gradual activity loss of TiO 2 -SnS 2 composite in applied solar-driven water treatment.

Controlling Cellular Endocytosis at the Nanoscale

NASA Astrophysics Data System (ADS)

Battaglia, Giuseppe

2011-03-01

One of the most challenging aspects of drug delivery is the intra-cellular delivery of active agents. Several drugs and especially nucleic acids all need to be delivered within the cell interior to exert their therapeutic action. Small hydrophobic molecules can permeate cell membranes with relative ease, but hydrophilic molecules and especially large macromolecules such as proteins and nucleic acids require a vector to assist their transport across the cell membrane. This must be designed so as to ensure intracellular delivery without compromising cell viability. We have recently achieved this by using pH-sensitive poly(2-(methacryloyloxy)ethyl-phosphorylcholine)- co -poly(2-(diisopropylamino)ethyl methacrylate) (PMPC-PDPA) and poly(ethylene oxide)-co- poly(2-(diisopropylamino)ethyl methacrylate) (PEO-PDPA) diblock copolymers that self-assemble to form vesicles in aqueous solution. These vesicles combine a non-fouling PMPC or PEO block with a pH-sensitive PDPA block and have the ability to encapsulate both hydrophobic molecules within the vesicular membrane and hydrophilic molecules within their aqueous cores. The pH sensitive nature of the PDPA blocks make the diblock copolymers forming stable vesicles at physiological pH but that rapid dissociation of these vesicles occurs between pH 5 and pH 6 to form molecularly dissolved copolymer chains (unimers). We used these vesicles to encapsulate small and large macromolecules and these were successfully delivered intracellularly including nucleic acid, drugs, quantum dots, and antibodies. Dynamic light scattering, zeta potential measurements, and transmission electron microscopy were used to study and optimise the encapsulation processes. Confocal laser scanning microscopy, fluorescence flow cytometry and lysates analysis were used to quantify cellular uptake and to study the kinetics of this process in vitro and in vivo. We show the effective cytosolic delivery of nucleic acids, proteins, hydrophobic molecules

High-Rate and Long-Term Cycle Stability of Li-S Batteries Enabled by Li2S/TiO2-Impregnated Hollow Carbon Nanofiber Cathodes.

PubMed

Wang, Xinran; Bi, Xuanxuan; Wang, Shaona; Zhang, Yi; Du, Hao; Lu, Jun

2018-05-16

The high theoretical energy density of lithium-sulfur (Li-S) batteries makes them an alternative battery technology to lithium ion batteries. However, Li-S batteries suffer from low sulfur loading, poor charge transport, and dissolution of lithium polysulfide. In our study, we use the lithiated S, Li 2 S, as the cathode material, coupled with electrospun TiO 2 -impregnated hollow carbon nanofibers (TiO 2 -HCFs), which serve as the conductive agent and protective barrier for Li 2 S in Li-S batteries. TiO 2 -HCFs provide much improved electron/ionic conductivity and serve as a physical barrier, which prevents the dissolution of lithium polysulfides. The Li 2 S/TiO 2 -HCF composite delivers a discharge capacity of 851 mA h g Li 2 S -1 at 0.1C and the bilayer TiO 2 -HCFs/Li 2 S/TiO 2 -HCF composite delivers a high specific capacity of 400 mA h g Li 2 S -1 at 5C.

Crystal structure of azilsartan methyl ester ethyl acetate hemisolvate.

PubMed

Li, Zhengyi; Liu, Rong; Zhu, Meilan; Chen, Liang; Sun, Xiaoqiang

2015-02-01

The title compound, C26H22N4O5 (systematic name: methyl 2-eth-oxy-1-{4-[2-(5-oxo-4,5-di-hydro-1,2,4-oxa-diazol-3-yl)phenyl]benz-yl}-1H-1,3-benzo-diazole-7-carboxyl-ate ethyl acetate hemisolvate), was obtained via cyclization of methyl (Z)-2-eth-oxy-1-{(2'-(N'-hy-droxy-carbamimido-yl)-[1,1'-biphen-yl]-4-yl)meth-yl}-1H-benzo[d]imidazole-7-carboxyl-ate with diphen-yl carbonate. There are two independent mol-ecules (A and B) with different conformations and an ethyl acetate solvent mol-ecule in the asymmetric unit. In mol-ecule A, the dihedral angle between the benzene ring and its attached oxa-diazole ring is 59.36 (17); the dihedral angle between the benzene rings is 43.89 (15) and that between the benzene ring and its attached imidazole ring system is 80.06 (11)°. The corres-ponding dihedral angles in mol-ecule B are 58.45 (18), 50.73 (16) and 85.37 (10)°, respectively. The C-O-C-Cm (m = meth-yl) torsion angles for the eth-oxy side chains attached to the imidazole rings in mol-ecules A and B are 93.9 (3) and -174.6 (3)°, respectively. In the crystal, the components are linked by N-H⋯N and C-H⋯O hydrogen bonds, generating a three-dimensional network. Aromatic π-π stacking inter-actions [shortest centroid-centroid separation = 3.536 (3)Å] are also observed.

Diastereoselective synthesis of ethyl ( Z)-3-(8-methylimidazo-[1,2- a]pyrid-2-yl)-2-phenylthioacrylate. X-ray crystal structure and conformational analysis

NASA Astrophysics Data System (ADS)

Gautier, A.; Roche, D.; Métin, J.; Carpy, A.; Madesclaire, M.

1995-09-01

The title compound 2, a gem vinyl sulfide ester, has been obtained diastereoselectively (de > 98%) by action of the ethyl thiophenoxyacetate carbanion on the imidazo[1,2- a]pyridinecarbaldehyde 1 in a basic medium, at low temperature. The X-ray crystal structure of 2 (C 19H 19N 2O 2S: Mr = 338.43, triclinic, P 1¯, a = 8.193(3) Å, b = 10.090(2) Å, c = 10.981(4) Å, α = 88.12(2)°, β = 78.66(4)°, γ = 78.53(2)°, V = 872.3(6) Å3, Z = 2, Dcalc = 1.29 g cm -3, λ( Mo Kα) = 0.71069 Å, μ = 0.189 mm -1, F(000) = 356, T = 293 K, R = 0.043 for 3610 observed reflections) has been determined and confirmed the Z configuration. The molecule is almost planar except for the phenyl ring situated in an approximate perpendicular plane. Despite the presence of the conjugate double bonds of the vinyl ester group (acrylate), coplanar with the imidazopyridine heterocycle, there is no evidence of π-electron delocalization over the whole structure. The crystal cohesion is ensured by a dense network of van der Waals contacts. A conformational analysis of the Z and E isomers by means of a Monte Carlo search and a stochastic dynamics simulation in CHCl 3 has shown that according to the method the Z isomer is more stable than the E isomer by about 7 to 10 kJ mol -1.

White LED based on CaAl2Si2O8:Eu2+ Mn2+ phosphor and CdS/ZnS quantum dots

NASA Astrophysics Data System (ADS)

Shen, Changyu; Zhong, Chuan; Hou, Qianglong; Li, Ke

2011-02-01

Core/shell CdS/ZnS quantum dots (QDs) with the emission wavelength of 610nm, was synthesized by thermal deposition using cadmium oxide and selenium as precursors in a hot lauric acid and hexadecylamine trioctylphosphine oxide hybrid. CaAl2Si2O8:Eu2+ Mn2+ phosphor was synthesized by high-temperature solid state reaction at 1290 °C for 2 hours under the H2 reducing atmosphere, and X-ray powder diffraction analysis confirmed the formation of it. It has two emission bands peaking at 420 nm and 580nm originated from the transition 5d to 4f of Eu2+ and 4T1-6A1 of Mn2+, respectively. Blends of CaAl2Si2O8:Eu2+,Mn2+ phosphor and CdS/ZnS QDs exhibited the prominent spectral evolution with an increasing content of QDs. A hybrid white LED, which combines a blue LED with the blend of CaAl2Si2O8:Eu2+ Mn2+ phosphor and QDs with a weight ratio of 2:1, with the CIE coordinate of (0.3183, 0.3036) and CRI of 85 was obtained.

19 CFR 10.99 - Importation of ethyl alcohol for nonbeverage purposes.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Importation of ethyl alcohol for nonbeverage purposes. 10.99 Section 10.99 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND... Provisions Ethyl Alcohol § 10.99 Importation of ethyl alcohol for nonbeverage purposes. (a) If claim is made...

Effective Biotransformation of Ethyl 4-Chloro-3-Oxobutanoate into Ethyl (S)-4-Chloro-3-Hydroxybutanoate by Recombinant E. coli CCZU-T15 Whole Cells in [ChCl][Gly]-Water Media.

PubMed

Dai, Yong; Huan, Bin; Zhang, Hai-Sheng; He, Yu-Cai

2017-04-01

To increase the biocatalytic activity of Escherichia coli CCZU-T15 whole cells, choline chloride/glycerol ([ChCl][Gly]) was firstly used as biocompatible solvent for the effective biotransformation of ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (S)-4-chloro-3-hydroxybutanoate [(S)-CHBE]. Furthermore, L-glutamine (150 mM) was added into [ChCl][Gly]-water ([ChCl][Gly] 12.5 vol%, pH 6.5) media instead of NAD + for increasing the biocatalytic efficiency. To further improve the biosynthesis of (S)-CHBE (>99 % e.e.) by E. coli CCZU-T15 whole cells, Tween-80 (7.5 mM) was also added into this reaction media, and (S)-CHBE (>9 % e.e.) could be effectively synthesized from 2000 and 3000 mM COBE in the yields of 100 and 93.0 % by whole cells of recombinant E. coli CCZU-T15, respectively. TEM image indicated that the cell membrane was permeabilized and lost its integrity and when the cell was exposed to [ChCl][Gly]-water media with Tween-80. Clearly, this bioprocess has high potential for the effective biosynthesis of (S)-CHBE (>99 % e.e.).

Ethyl 3-[1-(4-methoxy-phen-yl)-4-oxo-3-phenylazetidin-2-yl]-2-nitro-1-phenyl-2,3,10,10a-tetra-hydro-1H,5H-pyrrolo[1,2-b]isoquinoline-10a-carboxyl-ate.

PubMed

Sundaresan, S S; Ramesh, P; Arumugam, N; Raghunathan, R; Ponnuswamy, M N

2010-02-17

In the title mol-ecule, C(37)H(35)N(3)O(6), the pyrrolidine ring adopts a twist conformation and the piperidine ring is in a distorted boat conformation. One of the phenyl rings is disordered over two positions with occupancies of 0.54 (2) and 0.46 (2) and the ethyl carboxyl-ate group is also disordered over two orientations with occupancies of 0.75 (1) and 0.25 (1).

Ag2S/CdS/TiO2 Nanotube Array Films with High Photocurrent Density by Spotting Sample Method.

PubMed

Sun, Hong; Zhao, Peini; Zhang, Fanjun; Liu, Yuliang; Hao, Jingcheng

2015-12-01

Ag2S/CdS/TiO2 hybrid nanotube array films (Ag2S/CdS/TNTs) were prepared by selectively depositing a narrow-gap semiconductor-Ag2S (0.9 eV) quantum dots (QDs)-in the local domain of the CdS/TiO2 nanotube array films by spotting sample method (SSM). The improvement of sunlight absorption ability and photocurrent density of titanium dioxide (TiO2) nanotube array films (TNTs) which were obtained by anodic oxidation method was realized because of modifying semiconductor QDs. The CdS/TNTs, Ag2S/TNTs, and Ag2S/CdS/TNTs fabricated by uniformly depositing the QDs into the TNTs via the successive ionic layer adsorption and reaction (SILAR) method were synthesized, respectively. The X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectrum (XPS) results demonstrated that the Ag2S/CdS/TNTs prepared by SSM and other films were successfully prepared. In comparison with the four films of TNTs, CdS/TNTs, Ag2S/TNTs, and Ag2S/CdS/TNTs by SILAR, the Ag2S/CdS/TNTs prepared by SSM showed much better absorption capability and the highest photocurrent density in UV-vis range (320~800 nm). The cycles of local deposition have great influence on their photoelectric properties. The photocurrent density of Ag2S/CdS/TNTs by SSM with optimum deposition cycles of 6 was about 37 times that of TNTs without modification, demonstrating their great prospective applications in solar energy utilization fields.

Adsorption of acetanilide herbicides on soil and its components. II. Adsorption and catalytic hydrolysis of diethatyl-ethyl on saturated Na(+)-, K(+)-, Ca(2+)-, and Mg(2+)-montmorillonite.

PubMed

Liu, W P; Fang, Z; Liu, H J; Yang, W C

2001-04-01

Adsorption and catalytic hydrolysis of the herbicide diethatyl-ethyl [N-chloroacetyl-N-(2,6-diethylphenyl)glycine ethyl ester] on homoionic Na(+)-, K(+)-, Ca(2+)-, and Mg(2+)-montmorillonite clays were investigated in water solution. The Freundlich adsorption coefficient, Ki, got from isotherms on clay followed the order of Na+ approximately K+ > Mg2+ approximately Ca2+. Analysis of FT-IR spectra of diethatyl-ethyl adsorbed on clay suggests probable bonding at the carboxyl and amide carbonyl groups of the herbicide. The rate of herbicide hydrolysis in homoionic clay suspensions followed the same order as that for adsorption, indicating that adsorption may have preceded and thus caused hydrolysis. Preliminary product identification showed that hydrolysis occurred via nucleophilic substitution at the carboxyl carbon, causing the cleavage of the ester bond and formation of diethatyl and its dechlorinated derivative, and at the amide carbon, yielding an ethyl ester derivative and its acid. These pathways also suggest that hydrolysis of diethatyl-ethyl was catalyzed by adsorption on the clay surface.

On the chemical ladder of esters. Detection and formation of ethyl formate in the W51 e2 hot molecular core

NASA Astrophysics Data System (ADS)

Rivilla, V. M.; Beltrán, M. T.; Martín-Pintado, J.; Fontani, F.; Caselli, P.; Cesaroni, R.

2017-03-01

Context. In recent years, the detection of organic molecules with increasing complexity and potential biological relevance is opening the possibility to understand the formation of the building blocks of life in the interstellar medium. One of the families of molecules of substantial astrobiological interest are the esters. The simplest ester, methyl formate (CH3OCHO), is rather abundant in star-forming regions. The next step in the chemical complexity of esters is ethyl formate, C2H5OCHO. Despite the increase in sensitivity of current telescopes, the detection of complex molecules with more than ten atoms such as C2H5OCHO is still a challenge. Only two detections of this species have been reported so far, which strongly limits our understanding of how complex molecules are formed in the interstellar medium. New detections towards additional sources with a wide range of physical conditions are crucial to differentiate between competing chemical models based on dust grain surface and gas-phase chemistry. Aims: We have searched for ethyl formate towards the W51 e2 hot molecular core, one of the most chemically rich sources in the Galaxy and one of the most promising regions to study prebiotic chemistry, especially after the recent discovery of the P-O bond, key in the formation of DNA. Methods: We have analyzed a spectral line survey towards the W51 e2 hot molecular core, which covers 44 GHz in the 1, 2 and 3 mm bands, carried out with the IRAM 30 m telescope. Results: We report the detection of the trans and gauche conformers of ethyl formate. A local thermodynamic equilibrium analysis indicates that the excitation temperature is 78 ± 10 K and that the two conformers have similar source-averaged column densities of (2.0 ± 0.3) × 10-16 cm-2 and an abundance of 10-8. We compare for the first time the observed molecular abundances of ethyl formate with different competing chemical models based on grain surface and gas-phase chemistry. Conclusions: We propose that

40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the commodities in...

40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

Code of Federal Regulations, 2012 CFR

2012-07-01

... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the commodities in...

40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the commodities in...

Fragmentation dynamics of the ethyl bromide and ethyl iodide cations: a velocity-map imaging study.

PubMed

Gardiner, Sara H; Karsili, Tolga N V; Lipciuc, M Laura; Wilman, Edward; Ashfold, Michael N R; Vallance, Claire

2014-02-07

The photodissociation dynamics of ethyl bromide and ethyl iodide cations (C2H5Br(+) and C2H5I(+)) have been studied. Ethyl halide cations were formed through vacuum ultraviolet (VUV) photoionization of the respective neutral parent molecules at 118.2 nm, and were photolysed at a number of ultraviolet (UV) photolysis wavelengths, including 355 nm and wavelengths in the range from 236 to 266 nm. Time-of-flight mass spectra and velocity-map images have been acquired for all fragment ions and for ground (Br) and spin-orbit excited (Br*) bromine atom products, allowing multiple fragmentation pathways to be investigated. The experimental studies are complemented by spin-orbit resolved ab initio calculations of cuts through the potential energy surfaces (along the RC-Br/I stretch coordinate) for the ground and first few excited states of the respective cations. Analysis of the velocity-map images indicates that photoexcited C2H5Br(+) cations undergo prompt C-Br bond fission to form predominantly C2H5(+) + Br* products with a near-limiting 'parallel' recoil velocity distribution. The observed C2H3(+) + H2 + Br product channel is thought to arise via unimolecular decay of highly internally excited C2H5(+) products formed following radiationless transfer from the initial excited state populated by photon absorption. Broadly similar behaviour is observed in the case of C2H5I(+), along with an additional energetically accessible C-I bond fission channel to form C2H5 + I(+) products. HX (X = Br, I) elimination from the highly internally excited C2H5X(+) cation is deemed the most probable route to forming the C2H4(+) fragment ions observed from both cations. Finally, both ethyl halide cations also show evidence of a minor C-C bond fission process to form CH2X(+) + CH3 products.

In vitro protection of biological macromolecules against oxidative stress and in vivo toxicity evaluation of Acacia nilotica (L.) and ethyl gallate in rats

PubMed Central

2014-01-01

Background Recently, enormous research has been focused on natural bioactive compounds possessing potential antioxidant and anticancer properties using cell lines and animal models. Acacia nilotica (L.) is widely distributed in Asia, Africa, Australia and Kenya. The plant is traditionally used to treat mouth, ear and bone cancer. However, reports on Acacia nilotica (L.) Wild. Ex. Delile subsp. indica (Benth.) Brenan regarding its toxicity profile is limited. Hence in this study, we investigated the antioxidant capacity and acute toxicity of ethyl gallate, a phenolic antioxidant present in the A. nilotica (L.) leaf extract. Methods The antioxidant activity of ethyl gallate against Fenton’s system (Fe3+/H2O2/ascorbic acid) generated oxidative damage to pBR322 DNA and BSA was investigated. We also studied the interaction of ethyl gallate to CT-DNA by wave scan and FTIR analysis. The amount of ethyl gallate present in the A. nilotica (L.) leaf extract was calculated using HPLC and represented in gram equivalence of ethyl gallate. The acute toxicity profile of ethyl gallate in the A. nilotica (L.) leaf extract was analyzed in albino Wistar rats. Measurement of liver and kidney function markers, total proteins and glucose were determined in the serum. Statistical analysis was done using statistical package for social sciences (SPSS) tool version 16.0. Results Ethyl gallate was found to be effective at 100 μg/mL concentration by inhibiting the free radical mediated damage to BSA and pBR322 DNA. We also found that the interaction of ethyl gallate and A. nilotica (L.) leaf extract to CT-DNA occurs through intercalation. One gram of A. nilotica (L.) leaf extract was found to be equivalent to 20 mg of ethyl gallate through HPLC analysis. Based on the acute toxicity results, A. nilotica (L.) leaf extract and ethyl gallate as well was found to be non-toxic and safe. Conclusions Results revealed no mortality or abnormal biochemical changes in vivo and the protective effect

Water mediated synthesis, spectral and structural studies of ethyl 6-amino-4-aryl-5-cyano-2-propyl-4H-pyran-3-carboxylates: Single crystal X-ray structure of ethyl 6-amino-4-(2-chlorophenyl)-5-cyano-2-propyl-4H-pyran-3-carboxylate

NASA Astrophysics Data System (ADS)

Udhaya Kumar, C.; Sethukumar, A.; Agilandeshwari, R.; Arul Prakasam, B.; Vidhyasagar, T.; Sillanpää, Mika

2014-02-01

An efficient and multifunctional three component synthetic protocol was developed to synthesize ethyl 6-amino-4-aryl-5-cyano-2-propyl-4H-pyran-3-carboxylates from ethyl 3-oxohexanoate, malononitrile and corresponding aldehydes (1a-11a) using K2CO3 as a catalyst under water solvent in good yields. The derived compounds have been analyzed by IR and NMR (1D and 2D) spectra. Single crystal X-ray structural analysis of 2a, evidences the flattened-boat conformation of pyran ring and the phenyl group is nearly perpendicular to the pyran ring.

Experimental and modeling study of fuel interactions with an alkyl nitrate cetane enhancer, 2-ethyl-hexyl nitrate

DOE PAGES

Goldsborough, S. S.; Johnson, M. V.; Banyon, C.; ...

2014-07-15

Our study investigates the autoignition behavior of two gasoline surrogates doped with an alkyl nitrate cetane enhancer, 2-ethyl-hexyl nitrate (2EHN) to better understand dopant interactions with the fuels, including influences of accelerating kinetic pathways and enhanced exothermicity. A primary reference fuel (PRF) blend of n-heptane/iso-octane, and a toluene reference fuel (TRF) blend of n-heptane/iso-octane/toluene are used where the aromatic fraction of the latter is set to 20% (liquid volume), while the content of n-heptane is adjusted so that the overall reactivity of the undoped fuels is similar, e.g., Anti-Knock Index (AKI) of similar to 91, Cetane Number (CN) similar tomore » 25. Doping levels of 0.1, 1.0 and 3.0% (liquid volume basis) are used where tests are conducted within a rapid compression machine (RCM) at a compressed pressure of 21 bar, covering temperatures from 675 to 1025 K with stoichiometric fuel-oxygen ratios at O-2 = 11.4%. At the experimental conditions, it is found that the doping effectiveness of 2EHN is fairly similar between the two fuels, though 2EHN is more effective in the aromatic blend at the lowest temperatures, while it is slightly more effective in the non-aromatic blend at intermediate temperatures. Furthermore, kinetic modeling of the experiments indicates that although some of the reactivity trends can be captured using a detailed model, the extents of predicted Cetane Number enhancement by 2EHN are too large, while differences in fuel interactions for the two fuels result in excessive stimulation of the non-aromatic blend. Sensitivity analysis using the kinetic model indicates that the CH 2O and CH 3O 2 chemistry are very sensitive to the dopant at all conditions. The rate of 2EHN decomposition is only important at low temperatures where its decomposition rate is slow due to the high activation energy of the reaction. At higher temperatures, dopant-derived 3-heptyl radicals are predicted to play an important role

MnO2-GO double-shelled sulfur (S@MnO2@GO) as a cathode for Li-S batteries with improved rate capability and cyclic performance

NASA Astrophysics Data System (ADS)

Huang, Xingkang; Shi, Keying; Yang, Joseph; Mao, George; Chen, Junhong

2017-07-01

Sulfur cathodes have attracted much attention recently because of their high energy density and power density. However, sulfur possesses very poor electrical conductivity, and lithium polysulfides, resulting from the lithiation of sulfur, are prone to dissolving into electrolytes, which leads to the loss of active materials and poor cyclic performance of the sulfur cathodes. Here we report an MnO2-graphene oxide (GO) double-shelled sulfur (S@MnO2@GO) with improved rate capability and cyclic performance, in which we propose a new reaction using sulfur-reducing KMnO4 to produce MnO2 that covers the surface of the excess sulfur in situ. The resulting MnO2 with honeycomb-like morphology provides excellent voids for storing polysulfides. The outermost GO was assembled to block the open pores of MnO2, thereby minimizing the opportunity for polysulfides to leach into the electrolytes. The GO significantly improved the electrical conductivity of the sulfur cathode, and the S@MnO2@GO exhibited excellent rate capability and long cycle life.

AgS2O6CF3: the first trifluoromethylsulfonylsulfate(VI).

PubMed

Malinowski, Przemysław J; Derzsi, Mariana; Grochala, Wojciech

2013-08-07

We describe the synthetic route towards a novel class of salts, trifluoromethylsulfonylsulfates, as exemplified by the silver(I) derivative (AgS2O6CF3). Formation proceeds via direct reaction between a triflate precursor, AgSO3CF3, and SO3. The title compound crystallizes in the P2(1)/c unit cell with a = 5.15746(14) Å, b = 25.8563(9) Å, c = 5.53970(14) Å and β = 101.1749(19)°. The structure is layered with the puckered [AgS2O6] 2D sheets; the terminal CF3 groups are separated by the van der Waals gap, as seen also for related metal triflates. The compound is very fragile thermally and it decomposes endothermally to AgSO3CF3 with concomitant evolution of SO3 even at 65 °C or upon grinding in an agate mortar; thus it may serve as a solid store of--otherwise volatile and corrosive--SO3. The IR and Raman spectra of AgS2O6CF3 have been tentatively assigned based on similarities to those of related Ag2S2O7 and AgSO3CF3 and phonon calculations. Synthesis and properties of KS2O6CF3 are also briefly described.

Alkylation of deoxyribonucleic acid by carcinogens dimethyl sulphate, ethyl methanesulphonate, N-ethyl-N-nitrosourea and N-methyl-N-nitrosourea. Relative reactivity of the phosphodiester site thymidylyl(3'-5')thymidine.

PubMed Central

Swenson, D H; Lawley, P D

1978-01-01

1. The ethyl phosphotriester of thymidylyl(3'-5')thymidine, dTp(Et)dT, was identified as a product from reaction of DNA with N-ethyl-N-nitrosourea, by procedures parallel to those reported previously for the methyl homologue produced by N-methyl-N-nitrosourea. 2. Enzymic degradation to yield alkyl phosphotriesters from DNA alkylated by these carcinogens and by dimethyl sulphate and ethyl methanesulphonate was studied quantitatively, and the relative yields of the triesters dTp(Alk)dT were determined. The relative reactivity of the phosphodiester group dTpdT to each of the four carcinogens was thus obtained, and compared with that of DNA overall, or with that of the N-7 atom of guanine in DNA. Relative reactivity of the phosphodiester group was lowest towards dimethyl sulphate, the least electrophilic of the reagents used, and was highest towards N-ethyl-N-nitrosourea, the most electrophilic reagent. 3. The nature of the alkyl group transferred also influenced reactivity of the phosphodiester site, since this site was relatively more reactive towards ethylation than would be predicted simply from the known Swain-Scott s values of the alkylating agents. It was therefore suggested that the steric accessibility of the weakly nucleophilic phosphodiester group on the outside of the DNA macromolecule favours its reaction with ethylating, as opposed to methylating, reagents. 4. Taking a value of the Swain-Scott nucleophilicity (n) of 2.5 for an average DNA nucleotide unit [Walles & Ehrenberg (1969) Acta Chem. Scand. 23, 1080-1084], a value of n of about 1 for the phosphodiester group was deduced, and this value was found to be 2-3 units less than that for the N-7 atom of guanine in DNA. 5. The reactivity of DNA overall was markedly high towards the alkylnitrosoureas, despite their relatively low s values. This was ascribed to an electrostatic factor that favoured reaction of the negatively charged polymer with alkyldiazonium cation intermediates. PMID:208508

[Ethyl 4-methyloctanoate, major component of male pherome in Oryctes rhinoceros (L.) (Coleoptera, Dynastidae)].

PubMed

Morin, J P; Rochat, D; Malosse, C; Lettere, M; de Chenon, R D; Wibwo, H; Descoins, C

1996-07-01

Ethyl 4-methyloctanoate, which has already been described in Oryctes monoceros, has been identified, using extracts of effluvia collected from males, as being a major component of the male pheromone of O. rhinoceros. Field trials have been carried out in North Sumatra, Indonesia. Ethyl 4-methyloctanoate synthesized in the laboratory and released at 10 mg/d resulted in the capture of 6.8 insects per week per trap, whereas ethyl chrysanthemate (40 mg/d), an allelochemical compound once used as an attractant, only led to the capture of 0.3 insects, and the control none at all. The insects captured with the pheromone were 81% females, the majority being sexually mature. Discovery of this compound opens up new prospects for O. rhinoceros control.

The photodissociation dynamics of the ethyl radical, C2H5, investigated by velocity map imaging.

PubMed

Steinbauer, Michael; Giegerich, Jens; Fischer, Kathrin H; Fischer, Ingo

2012-07-07

The photodissociation dynamics of the ethyl radical C(2)H(5) has been investigated by velocity map imaging. Ethyl was produced by flash pyrolysis from n-propyl nitrite and excited to the à (2)A(') (3s) Rydberg state around 250 nm. The energetically most favorable reaction channel in this wavelength region is dissociation to C(2)H(4) (ethene) + H. The H-atom dissociation products were ionized in a [1+1(')] process via the 1s-2p transition. The observed translational energy distribution is bimodal: A contribution of slow H-atoms with an isotropic angular distribution peaks at low translational energies. An expectation value for the fraction of excess energy released into translation of = 0.19 is derived from the data, typical for statistical dissociation reactions. In addition, a fast H-atom channel is observed, peaking around 1.8 eV. The latter shows an anisotropic distribution with β = 0.45. It originates from a direct dissociation process within less than a rotational period. Time-delay scans with varying extraction voltages indicate the presence of two rates for the formation of H-atoms. One rate with a sub-nanosecond time constant is associated with H-atoms with large translational energy; a second one with a time constant on the order of 100 ns is associated with H-atoms formed with low translational energy. The data confirm and extend those from previous experiments and remove some inconsistencies. Possible mechanisms for the dissociation are discussed in light of the new results as well as previous ones.

Crystal structure of aqua-1κO-{μ-2-[(2-hydroxy-ethyl)methylamino]ethanolato-2:1κ(4) O (1),N,O (2):O (1)}[μ-2,2'-(methylimino)diethanolato-1:2κ(4) O,N,O':O]dithiocyanato-1κN,2κN-chromium(III)copper(II).

PubMed

Rusanova, Julia A; Semenaka, Valentina V; Dyakonenko, Viktoriya V; Shishkin, Oleg V

2015-09-01

The title compound, [CrCu(C5H11NO2)(C5H12NO2)(NCS)2(H2O)] or [Cr(μ-mdea)Cu(μ-Hmdea)(NCS)2H2O], (where mdeaH2 is N-methylethanolamine, C5H13NO2) is formed as a neutral heterometal Cu(II)/Cr(III) complex. The mol-ecular structure of the complex is based on a binuclear {CuCr(μ-O)2} core. The coordination environment of each metal atom involves the N,O,O atoms of the tridentate ligand, one bridging O atom of the ligand and the N atom of the thio-cyanato ligands. The Cu(II) ion adopts a distorted square-pyramidal coordination while the Cr(III) ion has a distorted octa-hedral coordination geometry completed by the aqua ligand. In the crystal, the binuclear complexes are linked via two pairs of O-H⋯O hydrogen bonds to form inversion dimers, which are arranged in columns parallel to the a axis. In the μ-mdea ligand two -CH2 groups and the methyl group were refined as disordered over two sets of sites with equal occupancies. The structure was refined as a two-component twin with a twin scale factor of 0.242 (1).

Aeronomical determinations of the quantum yields of O (1S) and O (1D) from dissociative recombination of O2(+)

NASA Technical Reports Server (NTRS)

Yee, Jeng-Hwa; Abreu, Vincent J.; Colwell, William B.

1989-01-01

Data from the visible-airglow experiment on the Atmosphere Explorer-E satellite have been used to determine the quantum yields of O (1S) and O (1D) from the dissociative recombination of O2(+) based on a constant total recombination rate from each vibrational level. A range of values between 0.05 and 0.18 has been obtained for the quantum yield of O (1S) and shows a positive correlation with the extent of the vibrational excitation of O2(+). The quantum yield of O (1D) has been measured to be 0.9 + or - 0.2, with no apparent dependence on the vibrational distribution of O2(+).

Observation of GaSe-SnO2 Heterostructure by XPS and AES

NASA Astrophysics Data System (ADS)

Tatsuyama, Chiei; Ichimura, Shoji; Iwakuro, Hiroaki

1982-01-01

The depth profile of the elemental composition of the GaSe-SnO2 heterostructure has been studied by XPS and AES. The SnO2 layer was prepared by spraying a solution of SnCl4 and SbCl3 in ethyl alcohol on to the the cleaved surface of GaSe heated to ˜400°C in air. After the solution had been sprayed on for about 5 secs., an SnO2 layer of thickness ˜460 Å formed, and a Ga2O3 layer of thickness ˜120 Å formed under the SnO2 layer. The Ga2O3 layer is a likely origin of the high-resistivity layer observed in the GaSe-SnO2 heterostructure.

A promising p-type transparent conducting material: Layered oxysulfide [Cu2S2][Sr3Sc2O5

NASA Astrophysics Data System (ADS)

Liu, Min-Ling; Wu, Li-Bin; Huang, Fu-Qiang; Chen, Li-Dong; Chen, I.-Wei

2007-12-01

Sr3Cu2Sc2O5S2, a layered oxysulfide, composed of anti-PbO-like [Cu2S2] slabs alternating with perovskitelike [Sr3Sc2O5] slabs, was systematically studied as a p-type transparent conducting material. The material has a wide energy gap of 3.1eV and a p-type electrical conductivity of 2.8Scm-1 at room temperature. The hole mobility of +150cm2V-1S-1 at room temperature, which is much higher than the typical value of ˜10-1-10width="0.3em"/>cm2V-1S-1 found in other copper compounds. The performances of bulk undoped Sr3Cu2Sc2O5S2 show the promise of copper oxysulfides as a class of p-type transparent conductive materials that is essential for optoelectronic applications.

The microstructure and photoluminescence of ZnO-MoS2 core shell nano-materials

NASA Astrophysics Data System (ADS)

Yu, H.; Liu, C. M.; Huang, X. Y.; Lei, M. Y.

2017-01-01

In this paper, ZnO-MoS2-FT (FT is the fabrication temperature of MoS2) core shell nano-material samples (with ZnO as a core and MoS2 as a shell material) were fabricated on ITO substrate using hydrothermal method. The crystal structure, morphology, optical absorption and photoluminescence (PL) of samples were investigated. Compared with that of pure ZnO nanorods, ZnO-MoS2-FT samples show an enhanced light absorption. In addition, ultraviolet (UV) and visible (Vis) PL intensity of ZnO-MoS2-FT samples excited by 325 nm laser are greatly weakened. The UV PL peak position is not changed obviously. However, the Vis PL peak position is changed visibly. The Vis PL of ZnO-MoS2-FT samples under UV excitation indicates that the ratio of oxygen interstitial to oxygen vacancy is decreased. The suppression of UV PL of ZnO-MoS2-FT samples may be related to the weakening of crystal quality of ZnO, easier separation of electron-hole pairs, enhancement of light absorption, and newly introduced defects in the interface between ZnO and MoS2. Under 514 nm laser excitation, the PL peak position of ZnO-MoS2-FT samples has a red shift with FT being increased from 80 to 160 °C. The influence of excitation power (EP) on the PL of ZnO-MoS2-FT samples was also investigated. The PL of ZnO-MoS2-FT samples have a red shift with EP being increased. This may be due to the sample temperature is increased with EP, resulting an enhancement of electron-phonon interaction. A schematic diagram of charge generation and transfer is presented to understand the mechanism of PL of ZnO-MoS2 under UV and Vis excitation.

Synthesis, Spectral Characterization, In-vitro Antibacterial and Antifungal Activities of Novel (2e)-Ethyl-2-(2-(2, 4-Dinitrophenyl) Hydrazono)-4-(Naphthalen-2-yl)-6-Arylcyclohex-3-Enecarboxylates

PubMed Central

Kanagarajan, V; Thanusu, J; Gopalakrishnan, M

2011-01-01

In a search for new leads towards potent antimicrobial agents, an array of novel (2E)-ethyl-2-(2-(2,4-dinitrophenyl)hydrazono)-4-(naphthalen-2-yl)-6-arylcyclohex-3-ene carboxylates 17-24 were synthesized and characterized through their melting point, elemental analysis, MS, FT-IR, one-dimensional NMR (1H, D2O exchanged 1H and 13C), two dimensional HOMOCOR and HSQC spectroscopic data. In-vitro microbiological evaluations were carried out for all the newly synthesized compounds 17-24 against clinically isolated bacterial strains namely Salmonella typhii, Klebsiellapneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, β-Hemolytic streptococcus and Micrococcus luteusand also fungal strains namely Aspergillusflavus, Aspergillusniger, Mucor, Rhizopus and Microsporumgypseumand finally, the results of their structure activity relationship were discussed. The obtained results can be used as the key step for the building of novel chemical compounds with interesting antimicrobial profiles comparable to that of the standard drugs. PMID:24250406

Synthesis, Spectral Characterization, In-vitro Antibacterial and Antifungal Activities of Novel (2e)-Ethyl-2-(2-(2, 4-Dinitrophenyl) Hydrazono)-4-(Naphthalen-2-yl)-6-Arylcyclohex-3-Enecarboxylates.

PubMed

Kanagarajan, V; Thanusu, J; Gopalakrishnan, M

2011-01-01

In a search for new leads towards potent antimicrobial agents, an array of novel (2E)-ethyl-2-(2-(2,4-dinitrophenyl)hydrazono)-4-(naphthalen-2-yl)-6-arylcyclohex-3-ene carboxylates 17-24 were synthesized and characterized through their melting point, elemental analysis, MS, FT-IR, one-dimensional NMR ((1)H, D2O exchanged (1)H and (13)C), two dimensional HOMOCOR and HSQC spectroscopic data. In-vitro microbiological evaluations were carried out for all the newly synthesized compounds 17-24 against clinically isolated bacterial strains namely Salmonella typhii, Klebsiellapneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, β-Hemolytic streptococcus and Micrococcus luteusand also fungal strains namely Aspergillusflavus, Aspergillusniger, Mucor, Rhizopus and Microsporumgypseumand finally, the results of their structure activity relationship were discussed. The obtained results can be used as the key step for the building of novel chemical compounds with interesting antimicrobial profiles comparable to that of the standard drugs.

Detection of s-wave superconductivity on monolayer CuO2 films on Bi2Sr2CaCu2O8+δ.

NASA Astrophysics Data System (ADS)

Wang, Yang; Zhong, Yong; Han, Sha; Lv, Yanfeng; Wang, Wenlin; Zhang, Ding; Ding, Hao; Zhang, Yimin; Wang, Lili; He, Ke; Song, Canli; Ma, Xucun; Xue, Qikun

High temperature superconductivity emerges when the CuO2 layer touches the doped charge reservoir blocks. The redistributed charge carriers at these interfaces condense into coherent Cooper pairs, albeit the exact underlying mechanism is still highly controversial. Targeting at this, we have mimicked the CuO2/charge reservoir interface by depositing the monolayer CuO2 films on optimal doped Bi2Sr2CaCu2O8+δ substrates. Direct investigation on these superconducting CuO2 films, however, yields results in stark contrast with the common recognition. Despite of the well-known V shaped pseudogap, a U shaped gap is identified. This U shaped gap disappears at TC and is indifference to K, Cs and Ag adsorbates, in line with the traditional s-wave superconductivity. In view of these results, we propose that superconductivity in cuprates may indeed stem from the modulation doping induced two dimensional hole liquid, which is confined in the CuO2 layers. NSF and MOST of China.

Synthesis and visible-light-induced catalytic activity of Ag2S-coupled TiO2 nanoparticles and nanowires

NASA Astrophysics Data System (ADS)

Xie, Yi; Heo, Sung Hwan; Kim, Yong Nam; Yoo, Seung Hwa; Cho, Sung Oh

2010-01-01

We present the synthesis and visible-light-induced catalytic activity of Ag2S-coupled TiO2 nanoparticles (NPs) and TiO2 nanowires (NWs). Through a simple wet chemical process from a mixture of peroxo titanic acid (PTA) solution, thiourea and AgAc, a composite of Ag2S NPs and TiO2 NPs with sizes of less than 7 nm was formed. When the NP composite was further treated with NaOH solution followed by annealing at ambient conditions, a new nanocomposite material comprising Ag2S NPs on TiO2 NWs was created. Due to the coupling with such a low bandgap material as Ag2S, the TiO2 nanocomposites could have a visible-light absorption capability much higher than that of pure TiO2. As a result, the synthesized Ag2S/TiO2 nanocomposites exhibited much higher catalytic efficiency for the decomposition of methyl orange than commercial TiO2 (Degussa P25, Germany) under visible light.

First principles study of CuAlO2 doping with S

NASA Astrophysics Data System (ADS)

Gao, Haigen; Zhou, Jian; Lu, Minghui

2010-07-01

We study the electronic properties of CuAlO2 doped with S by the first principles calculations and find that the band gap of CuAlO2 is reduced after the doping. At the same time, the effective masses are also reduced and the density of states could cross the Fermi level. These results show that the conductivity of CuAlO2 could be enhanced by doping the impurities of S, which needs to be further studied.

Photosynthetic CO2 Conversion to Fatty Acid Ethyl Esters (FAEEs) Using Engineered Cyanobacteria.

PubMed

Lee, Hyun Jeong; Choi, Jaeyeon; Lee, Sun-Mi; Um, Youngsoon; Sim, Sang Jun; Kim, Yunje; Woo, Han Min

2017-02-15

Metabolic engineering of cyanobacteria has received attention as a sustainable strategy to convert carbon dioxide to fatty acid-derived chemicals that are widely used in the food and chemical industries. Herein, Synechococcus elongatus PCC 7942, a model cyanobacterium, was engineered for the first time to produce fatty acid ethyl esters (FAEEs) from CO 2 . Due to the lack of an endogenous ethanol production pathway and wax ester synthase (AftA) activity in the wild-type cyanobacterium, we metabolically engineered S. elongatus PCC 7942 by expressing heterologous AftA and introducing the ethanol pathway, resulting in detectable peaks of FAEEs. To enhance FAEE production, a heterologous phosphoketolase pathway was introduced in the FAEE-producing strain to supply acetyl-CoA. Subsequent optimization of the cyanobacterial culture with a hexadecane overlay resulted in engineered S. elongatus PCC 7942 that produced photosynthetic FAEEs (10.0 ± 0.7 mg/L/OD 730 ) from CO 2 . This paper is the first report of photosynthetic production of FAEEs from CO 2 in cyanobacteria.

Nitrosamine-induced carcinogenesis. The alkylation of N-7 of guanine of nucleic acids of the rat by diethylnitrosamine, N-ethyl-N-nitrosourea and ethyl methanesulphonate

PubMed Central

Swann, P. F.; Magee, P. N.

1971-01-01

1. The extent of ethylation of N-7 of guanine in the nucleic acids of rat tissue in vivo by diethylnitrosamine, N-ethyl-N-nitrosourea and ethyl methanesulphonate was measured. 2. All compounds produced measurable amounts of 7-ethyl-guanine. 3. A single dose of diethylnitrosamine or N-ethyl-N-nitrosourea produced tumours of the kidney in the rat. Three doses of ethyl methanesulphonate produced kidney tumours, but a single dose did not. 4. A single dose of diethylnitrosamine produced twice as much ethylation of N-7 of guanine in DNA of kidney as did N-ethyl-N-nitrosourea. A single dose of both compounds induced kidney tumours, although of a different histological type. 5. A single dose of ethyl methanesulphonate produced ten times as much ethylation of N-7 of guanine in kidney DNA as did N-ethyl-N-nitrosourea without producing tumours. 6. The relevance of these findings to the hypothesis that alkylation of a cellular component is the mechanism of induction of tumours by nitroso compounds is discussed. PMID:5145908

Reactivity and dynamics of H2S, NO, and O2 interacting with hemoglobins from Lucina pectinata.

PubMed

Ramos-Alvarez, Cacimar; Yoo, Byung-Kuk; Pietri, Ruth; Lamarre, Isabelle; Martin, Jean-Louis; Lopez-Garriga, Juan; Negrerie, Michel

2013-10-08

Hemoglobin HbI from the clam Lucina pectinata is involved in H2S transport, whereas homologous heme protein HbII/III is involved in O2 metabolism. Despite similar tertiary structures, HbI and HbII/III exhibit very different reactivity toward heme ligands H2S, O2, and NO. To investigate this reactivity at the heme level, we measured the dynamics of ligand interaction by time-resolved absorption spectroscopy in the picosecond to nanosecond time range. We demonstrated that H2S can be photodissociated from both ferric and ferrous HbI. H2S geminately rebinds to ferric and ferrous out-of-plane iron with time constants (τgem) of 12 and 165 ps, respectively, with very different proportions of photodissociated H2S exiting the protein (24% in ferric and 80% in ferrous HbI). The Gln(E7)His mutation considerably changes H2S dynamics in ferric HbI, indicating the role of Gln(E7) in controling H2S reactivity. In ferric HbI, the rate of diffusion of H2S from the solvent into the heme pocket (kentry) is 0.30 μM(-1) s(-1). For the HbII/III-O2 complex, we observed mainly a six-coordinate vibrationally excited heme-O2 complex with O2 still bound to the iron. This explains the low yield of O2 photodissociation and low koff from HbII/III, compared with those of HbI and Mb. Both isoforms behave very differently with regard to NO and O2 dynamics. Whereas the amplitude of geminate rebinding of O2 to HbI (38.5%) is similar to that of myoglobin (34.5%) in spite of different distal heme sites, it appears to be much larger for HbII/III (77%). The distal Tyr(B10) side chain present in HbII/III increases the energy barrier for ligand escape and participates in the stabilization of bound O2 and NO.

Magic wavelengths for the 6{s}^{2}{}^{1}{S}_{0}{--}6s6p{}^{3}{P}_{1}^{o} transition in ytterbium atom

NASA Astrophysics Data System (ADS)

Tang, Zhi-Ming; Yu, Yan-Mei; Jiang, Jun; Dong, Chen-Zhong

2018-06-01

The static and dynamic electric dipole polarizabilities of the 6{s}2{}1{S}0 and 6s6p{}3{P}1o states of Yb are calculated by using the relativistic ab initio method. Focusing on the red detuning region to the 6{s}2{}1{S}0{--}6s6p{}3{P}1o transition, we find two magic wavelengths at 1035.7(2) and 612.9(2) nm for the 6{s}2{}1{S}0{--}6s6p{}3{P}1o,{M}J=0 transition and three magic wavelengths at 1517.68(6), 1036.0(3) and 858(12) nm for the 6{s}2{}1{S}0{--}6s6p{}3{P}1o,{M}J=+/- 1 transitions. Such magic wavelengths are of particular interest for attaining the state-insensitive cooling, trapping, and quantum manipulation of neutral Yb atom.

Visible light CrO4(2-) reduction using the new CuAlO2/CdS hetero-system.

PubMed

Brahimi, R; Bessekhouad, Y; Nasrallah, N; Trari, M

2012-06-15

In this study, 64% of hexavalent chromium Cr(VI) reduction from the initial concentration (10(-4) M) is reported under visible light using the (CuAlO(2)/CdS) hetero-system. In this new hetero-system, low doped CuAlO(2) delafossite, synthesized by sol-gel works as an electrons reservoir with a wide space charge region (440 nm). In this case, the electron transfer to chromate is mediated via the hexagonal CdS variety, whose conduction band level is at -1.08 V with respect to the saturated calomel electrode which is more negative than the CrO(4)(2-)/Cr(3+) level. This high reduction rate is achieved under optimized pH and CuAlO(2) percentage. Moreover, salicylic acid gives the best performance among hole scavengers and CuAlO(2) approaches 100% photostability at pH 7.5. The photo-catalytic process follows a pseudo first order kinetic with a half life of 2h. The reaction products are identified by UV-visible spectrophotometry and linear voltametry at a platinum rotating electrode. The results reveal the presence of Cr(3+) after irradiation. Copyright © 2012. Published by Elsevier B.V.

Crystal structure of bis­(3-bromo­pyridine-κN)bis­(O-ethyl di­thio­carbonato-κ2 S,S′)nickel(II)

PubMed Central

Kant, Rajni; Kour, Gurvinder; Anthal, Sumati; Neerupama; Sachar, Renu

2015-01-01

In the title mol­ecular complex, [Ni(C3H5OS2)2(C5H4BrN)2], the Ni2+ cation is located on a centre of inversion and has a distorted octa­hedral N2S4 environment defined by two chelating xanthate ligands and two monodentate pyridine ligands. The C—S bond lengths of the thio­carboxyl­ate group are indicative of a delocalized bond and the O—Csp 2 bond is considerably shorter than the O—Csp 3 bond, consistent with a significant contribution of one resonance form of the xanthate anion that features a formal C=O+ unit and a negative charge on each of the S atoms. The packing of the mol­ecules is stabilized by C—H⋯S and C—H⋯π inter­actions. In addition, π–π inter­actions between the pyridine rings [centroid-to-centroid distance = 3.797 (3) Å] are also present. In the crystal structure, mol­ecules are arranged in rows along [100], forming layers parallel to (010) and (001). PMID:25705471

40 CFR 721.10457 - 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 1,2-Benzenedicarboxylic acid, mixed... Substances § 721.10457 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1... reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, mixed esters with benzyl...

40 CFR 721.10457 - 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 1,2-Benzenedicarboxylic acid, mixed... Substances § 721.10457 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1... reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, mixed esters with benzyl...

40 CFR 721.10595 - Octadecen-1-aminium, N-ethyl-N,N-dimethy-, ethyl sulfate (1:1).

Code of Federal Regulations, 2013 CFR

2013-07-01

...-dimethy-, ethyl sulfate (1:1). 721.10595 Section 721.10595 Protection of Environment ENVIRONMENTAL...-, ethyl sulfate (1:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as octadecen-1-aminium, N-ethyl-N,N-dimethy-, ethyl sulfate (1:1) (PMN P-11...

40 CFR 721.10595 - Octadecen-1-aminium, N-ethyl-N,N-dimethy-, ethyl sulfate (1:1).

Code of Federal Regulations, 2014 CFR

2014-07-01

...-dimethy-, ethyl sulfate (1:1). 721.10595 Section 721.10595 Protection of Environment ENVIRONMENTAL...-, ethyl sulfate (1:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as octadecen-1-aminium, N-ethyl-N,N-dimethy-, ethyl sulfate (1:1) (PMN P-11...

SiO2-induced release of sVEGFRs from pulmonary macrophages.

PubMed

Chao, Jie; Lv, Yan; Chen, Jin; Wang, Jing; Yao, Honghong

2018-01-01

The inhalation of silicon dioxide (SiO 2 ) particles causes silicosis, a stubborn pulmonary disease that is characterized by alveolar inflammation during the early stage. Soluble cytokine receptors (SCRs) play important roles in regulating inflammation by either attenuating or promoting cytokine signaling. However, the role of SCRs in silicosis remains unknown. Luminex assays revealed increased soluble vascular endothelial growth factor receptor (sVEGFR) family levels in the plasma of silicosis patients. In an enzyme-linked immunosorbent assay (ELISA), cells from the differentiated human monocytic cell line U937 released sVEGFR family proteins after exposure to SiO 2 (50μg/cm 2 ). Further Western blot experiments revealed that VEGFR expression was also elevated in U937 cells. In contrast, levels of sVEGFR family members did not change in the supernatants of human umbilical vein endothelial cells (HUVECs) after exposure to SiO 2 (50μg/cm 2 ). Interestingly, VEGFR expression in HUVECs decreased after SiO 2 treatment. In a scratch assay, HUVECs exhibited cell migration ability, indicating the acquisition of mesenchymal properties. Our findings highlight the important role of sVEGFRs in both inflammation and fibrosis induced by SiO 2 , suggesting a possible mechanism for the fibrogenic effects observed in pulmonary diseases associated with fibrosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Construction of Hierarchical CuO/Cu2O@NiCo2S4 Nanowire Arrays on Copper Foam for High Performance Supercapacitor Electrodes

PubMed Central

Zhou, Luoxiao; He, Ying; Jia, Congpu; Pavlinek, Vladimir; Saha, Petr; Cheng, Qilin

2017-01-01

Hierarchical copper oxide @ ternary nickel cobalt sulfide (CuO/Cu2O@NiCo2S4) core-shell nanowire arrays on Cu foam have been successfully constructed by a facile two-step strategy. Vertically aligned CuO/Cu2O nanowire arrays are firstly grown on Cu foam by one-step thermal oxidation of Cu foam, followed by electrodeposition of NiCo2S4 nanosheets on the surface of CuO/Cu2O nanowires to form the CuO/Cu2O@NiCo2S4 core-shell nanostructures. Structural and morphological characterizations indicate that the average thickness of the NiCo2S4 nanosheets is ~20 nm and the diameter of CuO/Cu2O core is ~50 nm. Electrochemical properties of the hierarchical composites as integrated binder-free electrodes for supercapacitor were evaluated by various electrochemical methods. The hierarchical composite electrodes could achieve ultrahigh specific capacitance of 3.186 F cm−2 at 10 mA cm−2, good rate capability (82.06% capacitance retention at the current density from 2 to 50 mA cm−2) and excellent cycling stability, with capacitance retention of 96.73% after 2000 cycles at 10 mA cm−2. These results demonstrate the significance of optimized design and fabrication of electrode materials with more sufficient electrolyte-electrode interface, robust structural integrity and fast ion/electron transfer. PMID:28914819

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2012 CFR

2012-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...

Development and Application of Binary Suspensions in the Ternary System Cr2O3-TiO2-Al2O3 for S-HVOF Spraying

NASA Astrophysics Data System (ADS)

Potthoff, Annegret; Kratzsch, Robert; Barbosa, Maria; Kulissa, Nick; Kunze, Oliver; Toma, Filofteia-Laura

2018-04-01

Compositions in the system Cr2O3-TiO2-Al2O3 are among the most used ceramic materials for thermally sprayed coating solutions. Cr2O3 coatings present good sliding wear resistance; Al2O3 coatings show excellent insulation behavior and TiO2 striking corrosion properties. In order to combine these properties, coatings containing more than one oxide are highly interesting. The conventional spraying process is limited to the availability of binary feedstock powders with defined compositions. The use of suspensions offers the opportunity for tailor-made chemical compositions: within the triangle of Cr2O3-TiO2-Al2O3, each mixture of oxides can be created. Criteria for the selection of raw materials as well as the relevant aspects for the development of binary suspensions in the Cr2O3-TiO2-Al2O3 system to be used as feedstock for thermal spraying are presented. This formulation of binary suspensions required the development of water-based single-oxide suspensions with suitable behavior; otherwise, the interaction between the particles while mixing could lead up to a formation of agglomerates, which affect both the stability of the spray process and the coating properties. For the validation of this formulation procedure, binary Cr2O3-TiO2 and Al2O3-TiO2 suspensions were developed and sprayed using the S-HVOF process. The binary coatings were characterized and discussed in terms of microstructure and microhardness.

The OI/1S/ state - Its quenching by O2 and formation by the dissociative recombination of vibrationally excited O2/+/ ions

NASA Technical Reports Server (NTRS)

Zipf, E. C.

1979-01-01

The rate coefficient for the quenching of metastable O(1S) atoms by O2 was measured as a function of temperature from 250 to 550 K. The resulting Arrhenius expression correlates well with previous laboratory work. It is suggested that the much larger value of the rate coefficient inferred from an analysis of artificial auroral experiment, Precede, may be explained by overestimation of the contribution of O(1S) production from O2(+) dissociative recombination. The possibility that O(1S) atoms are produced only by the dissociative recombination of vibrationally excited O2(+) ions is examined; such excited ions would not exist in the Precede experiment because of the rapid cooling of the ions by resonant charge transfer processes.

Furfuryl ethyl ether: important aging flavor and a new marker for the storage conditions of beer.

PubMed

Vanderhaegen, Bart; Neven, Hedwig; Daenen, Luk; Verstrepen, Kevin J; Verachtert, Hubert; Derdelinckx, Guy

2004-03-24

Recently, it was reported that furfuryl ethyl ether is an important flavor compound indicative of beer storage and aging conditions. A study of the reaction mechanism indicates that furfuryl ethyl ether is most likely formed by protonation of furfuryl alcohol or furfuryl acetate followed by S(N)2-substitution of the leaving group by the nucleophilic ethanol. For the reaction in beer, a pseudo-first-order reaction kinetics was derived. A close correlation was found between the values predicted by the kinetic model and the actual furfuryl ethyl ether concentration evolution during storage of beer. Furthermore, 10 commercial beers of different types, aged during 4 years in natural conditions, were analyzed, and it was found that the furfuryl ethyl ether flavor threshold was largely exceeded in each type of beer. In these natural aging conditions, lower pH, darker color, and higher alcohol content were factors that enhanced furfuryl ethyl ether formation. On the other hand, sulfite clearly reduced furfuryl ethyl ether formation. All results show that the furfuryl ethyl ether concentration is an excellent time-temperature integrator for beer storage.

Enhanced carrier mobility of multilayer MoS2 thin-film transistors by Al2O3 encapsulation

NASA Astrophysics Data System (ADS)

Kim, Seong Yeoul; Park, Seonyoung; Choi, Woong

2016-10-01

We report the effect of Al2O3 encapsulation on the carrier mobility and contact resistance of multilayer MoS2 thin-film transistors by statistically investigating 70 devices with SiO2 bottom-gate dielectric. After Al2O3 encapsulation by atomic layer deposition, calculation based on Y-function method indicates that the enhancement of carrier mobility from 24.3 cm2 V-1 s-1 to 41.2 cm2 V-1 s-1 occurs independently from the reduction of contact resistance from 276 kΩ.μm to 118 kΩ.μm. Furthermore, contrary to the previous literature, we observe a negligible effect of thermal annealing on contact resistance and carrier mobility during the atomic layer deposition of Al2O3. These results demonstrate that Al2O3 encapsulation is a useful method of improving the carrier mobility of multilayer MoS2 transistors, providing important implications on the application of MoS2 and other two-dimensional materials into high-performance transistors.

Enhanced photocatalytic performance from NiS/TiO2 p-n heterojunction nanosheet arrays

NASA Astrophysics Data System (ADS)

Qian, Long-Long; Li, Yan; Li, Jian-feng; Wang, Cheng-Wei

2018-05-01

A novel p-n heterostructural film photocatalyst of oriented NiS/TiO2 nanosheet arrays were designed and successfully fabricated via a simple two-step hydrothermal process, and its photodegradation activities of methyl orange (MO) were detailedly investigated. Combining p-type NiS nanoparticles with n-type TiO2 nanosheets to construct distributed p-n heterojunctions, the absorption edge of NiS/TiO2 red-shifted to about 471 nm and its photoresponse in visible range significantly enhanced. Compared with pure TiO2 nanosheet arrays (NSAs), the assembled NiS/TiO2 p-n heterostructural arrays with 0.003 M NiS in hydrothermal precursor solution showed an optimal degradation rate of k = 0.7368 h-1 for MO, achieving 76.3% photocatalytic efficiency within 120 min, which is about 2.34 times higher than that of pure TiO2 nanosheet arrays (k = 0.3144 h-1). Such enhanced photocatalytic activities should be attributed to both the high efficiency of photogenerated charge separation by the built-in electric field at interfaces of NiS-TiO2 and the oriented thin nanosheet structures for smoothly charge transportation for redox reactions at surfaces of NiS/TiO2.

Effects of HfO2 encapsulation on electrical performances of few-layered MoS2 transistor with ALD HfO2 as back-gate dielectric.

PubMed

Xu, Jingping; Wen, Ming; Zhao, Xinyuan; Liu, Lu; Song, Xingjuan; Lai, Pui-To; Tang, Wing-Man

2018-08-24

The carrier mobility of MoS 2 transistors can be greatly improved by the screening role of high-k gate dielectric. In this work, atomic-layer deposited (ALD) HfO 2 annealed in NH 3 is used to replace SiO 2 as the gate dielectric to fabricate back-gated few-layered MoS 2 transistors, and good electrical properties are achieved with field-effect mobility (μ) of 19.1 cm 2 V -1 s -1 , subthreshold swing (SS) of 123.6 mV dec -1 and on/off ratio of 3.76 × 10 5 . Furthermore, enhanced device performance is obtained when the surface of the MoS 2 channel is coated by an ALD HfO 2 layer with different thicknesses (10, 15 and 20 nm), where the transistor with a 15 nm HfO 2 encapsulation layer exhibits the best overall electrical properties: μ = 42.1 cm 2 V -1 s -1 , SS = 87.9 mV dec -1 and on/off ratio of 2.72 × 10 6 . These improvements should be associated with the enhanced screening effect on charged-impurity scattering and protection from absorption of environmental gas molecules by the high-k encapsulation. The capacitance equivalent thickness of the back-gate dielectric (HfO 2 ) is only 6.58 nm, which is conducive to scaling of the MoS 2 transistors.

40 CFR 721.2465 - Xanthylium, 9-(2-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2465 Xanthylium, 9-(2-(ethoxycarbonyl)phenyl)-3,6-bis(ethylamino)-2,7-dimethyl-, ethyl sulfate. (a) Chemical substance and significant...

Preparation of MoS2/TiO2 based nanocomposites for photocatalysis and rechargeable batteries: progress, challenges, and perspective.

PubMed

Chen, Biao; Meng, Yuhuan; Sha, Junwei; Zhong, Cheng; Hu, Wenbin; Zhao, Naiqin

2017-12-21

The rapidly increasing severity of the energy crisis and environmental degradation are stimulating the rapid development of photocatalysts and rechargeable lithium/sodium ion batteries. In particular, MoS 2 /TiO 2 based nanocomposites show great potential and have been widely studied in the areas of both photocatalysis and rechargeable lithium/sodium ion batteries due to their superior combination properties. In addition to the low-cost, abundance, and high chemical stability of both MoS 2 and TiO 2 , MoS 2 /TiO 2 composites also show complementary advantages. These include the strong optical absorption of TiO 2 vs. the high catalytic activity of MoS 2 , which is promising for photocatalysis; and excellent safety and superior structural stability of TiO 2 vs. the high theoretic specific capacity and unique layered structure of MoS 2 , thus, these composites are exciting as anode materials. In this review, we first summarize the recent progress in MoS 2 /TiO 2 -based nanomaterials for applications in photocatalysis and rechargeable batteries. We highlight the synthesis, structure and mechanism of MoS 2 /TiO 2 -based nanomaterials. Then, advancements and strategies for improving the performance of these composites in photocatalytic degradation, hydrogen evolution, CO 2 reduction, LIBs and SIBs are critically discussed. Finally, perspectives on existing challenges and probable opportunities for future exploration of MoS 2 /TiO 2 -based composites towards photocatalysis and rechargeable batteries are presented. We believe the present review would provide enriched information for a deeper understanding of MoS 2 /TiO 2 composites and open avenues for the rational design of MoS 2 /TiO 2 based composites for energy and environment-related applications.

Dual role of monolayer MoS{sub 2} in enhanced photocatalytic performance of hybrid MoS{sub 2}/SnO{sub 2} nanocomposite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Shuang-Shuang; Huang, Wei-Qing, E-mail: wqhuang@hnu.edu.cn, E-mail: gfhuang@hnu.edu.cn; Yang, Yin-Cai

2016-05-28

The enhanced photocatalytic performance of various MoS{sub 2}-based nanomaterials has recently been observed, but the role of monolayer MoS{sub 2} is still not well elucidated at the electronic level. Herein, focusing on a model system, hybrid MoS{sub 2}/SnO{sub 2} nanocomposite, we first present a theoretical elucidation of the dual role of monolayer MoS{sub 2} as a sensitizer and a co-catalyst by performing density functional theory calculations. It is demonstrated that a type-II, staggered, band alignment of ∼0.49 eV exists between monolayer MoS{sub 2} and SnO{sub 2} with the latter possessing the higher electron affinity, or work function, leading to the robustmore » separation of photoexcited charge carriers between the two constituents. Under irradiation, the electrons are excited from Mo 4d orbitals to SnO{sub 2}, thus enhancing the reduction activity of latter, indicating that the monolayer MoS{sub 2} is an effective sensitizer. Moreover, the Mo atoms, which are catalytically inert in isolated monolayer MoS{sub 2}, turn into catalytic active sites, making the monolayer MoS{sub 2} to be a highly active co-catalyst in the composite. The dual role of monolayer MoS{sub 2} is expected to arise in other MoS{sub 2}-semiconductor nanocomposites. The calculated absorption spectra can be rationalized by available experimental results. These findings provide theoretical evidence supporting the experimental reports and pave the way for developing highly efficient MoS{sub 2}-based photocatalysts.« less

Degradation and mineralization of Bisphenol A (BPA) in aqueous solution using advanced oxidation processes: UV/H2O2 and UV/S2O8(2-) oxidation systems.

PubMed

Sharma, Jyoti; Mishra, I M; Kumar, Vineet

2015-06-01

This work reports on the removal and mineralization of an endocrine disrupting chemical, Bisphenol A (BPA) at a concentration of 0.22 mM in aqueous solution using inorganic oxidants (hydrogen peroxide, H2O2 and sodium persulfate, Na2S2O8;S2O8(2-)) under UV irradiation at a wavelength of 254 nm and 40 W power (Io = 1.26 × 10(-6) E s(-1)) at its natural pH and a temperature of 29 ± 3 °C. With an optimum persulfate concentration of 1.26 mM, the UV/S2O8(2-) process resulted in ∼95% BPA removal after 240 min of irradiation. The optimum BPA removal was found to be ∼85% with a H2O2 concentration of 11.76 mM. At higher concentrations, either of the oxidants showed an adverse effect because of the quenching of the hydroxyl or sulfate radicals in the BPA solution. The sulfate-based oxidation process could be used over a wider initial pH range of 3-12, but the hydroxyl radical-based oxidation of BPA should be carried out in the acidic pH range only. The water matrix components (bicarbonate, chloride and humic acid) showed higher scavenging effect in hydroxyl radical-based oxidation than that in the sulfate radical-based oxidation of BPA. UV/S2O8(2-) oxidation system utilized less energy (307 kWh/m(3)) EE/O in comparison to UV/H2O2 system (509 kWh/m(3)) under optimum operating conditions. The cost of UV irradiation far outweighed the cost of the oxidants in the process. However, the total cost of treatment of persulfate-based system was much lower than that of H2O2-based oxidation system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of HCl and H2SO4 treatment of TiO2 powder on the photosensitized degradation of aqueous rhodamine B under visible light.

PubMed

Park, Se-Keun; Shin, Hyunho

2014-10-01

The acid treatments of TiO2 nanopowder with HCI or H2SO4 solution increase the concentration of the hydroxyl group on TiO2 surfaces compared to bare TiO2, which acts as a Brønsted acid site. For the case of the HCl-treated TiO2, the dissociation of Brønsted acid (proton donor) sites on TiO2 leads to a drop in the pH levels of rhodamine B (RhB) dye solutions (leading to the protonation of the RhB molecule), which allows the physisorption of the uncharged carboxyl acid group on the positively charged TiO2 surface. The carboxyl acid group is believed to afford a more efficient charge injection from the Visible-light-excited RhB to the conduction band of TiO2 compared to the N-ethyl group, yielding a significantly enhanced photodegradation of RhB mainly via the N-de-ethylation pathway. For the case of the H2SO4-treated TiO2, although the dissociation of Brønsted acid sites on TiO2 is also achieved, its photoactivity is much lower than that of the HCl-treated TiO2. It seems that the presence of SO4(2-) on the H2SO4-treated TiO2 behaves as an *OH scavenger to prevent the photodegradation of the dye.