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Sample records for acetone vapor sensing

  1. Acetone vapor sensing using a vertical cavity surface emitting laser diode coated with polystyrene

    DEFF Research Database (Denmark)

    Ansbæk, Thor; Nielsen, Claus Højgaard; Larsen, Niels Bent

    2009-01-01

    We report theoretical and experimental on a new vapor sensor, using a single-mode vertical-cavity surface-emitting laser (VCSEL) coated with a polymer sensor coating, which can detect acetone vapor at a volume fraction of 2.5%. The sensor provides the advantage of standard packaging, small form...

  2. An analysis of human response to the irritancy of acetone vapors

    NARCIS (Netherlands)

    Arts, J.H.E.; Mojet, J.; Gemert, L.J. van; Emmen, H.H.; Lammers, J.H.C.M.; Marquart, J.; Woutersen, R.A.; Feron, V.J.

    2002-01-01

    Studies on the irritative effects of acetone vapor in humans and experimental animals have revealed large differences in the lowest acetone concentration found to be irritative to the respiratory tract and eyes. This has brought on much confusion in the process of setting occupational exposure limit

  3. Enhanced Acetone Sensing Characteristics of ZnO/Graphene Composites.

    Science.gov (United States)

    Zhang, Hao; Cen, Yuan; Du, Yu; Ruan, Shuangchen

    2016-11-09

    ZnO/graphene (ZnO-G) hybrid composites are prepared via hydrothermal synthesis with graphite, N-methyl-pyrrolidone (NMP), and Zn(NO₃)₂·6H₂O as the precursors. The characterizations, including X-ray diffraction (XRD), thermogravimetric analyses (TGA), Raman spectroscopy, and transmission electron microscopy (TEM) indicate the formation of ZnO-G. Gas sensors were fabricated with ZnO-G composites and ZnO as sensing material, indicating that the response of the ZnO towards acetone was significantly enhanced by graphene doping. It was found that the ZnO-G sensor exhibits remarkably enhanced response of 13.3 at the optimal operating temperature of 280 °C to 100 ppm acetone, an improvement from 7.7 with pure ZnO.

  4. Enhanced Acetone Sensing Characteristics of ZnO/Graphene Composites

    OpenAIRE

    Hao Zhang; Yuan Cen; Yu Du; Shuangchen Ruan

    2016-01-01

    ZnO/graphene (ZnO-G) hybrid composites are prepared via hydrothermal synthesis with graphite, N-methyl-pyrrolidone (NMP), and Zn(NO3)2·6H2O as the precursors. The characterizations, including X-ray diffraction (XRD), thermogravimetric analyses (TGA), Raman spectroscopy, and transmission electron microscopy (TEM) indicate the formation of ZnO-G. Gas sensors were fabricated with ZnO-G composites and ZnO as sensing material, indicating that the response of the ZnO towards acetone was significant...

  5. Low temperature acetone detection by p-type nano-titania thin film: Equivalent circuit model and sensing mechanism

    Science.gov (United States)

    Bhowmik, B.; Dutta, K.; Hazra, A.; Bhattacharyya, P.

    2014-09-01

    Undoped nanocrystalline anatase p-type TiO2 thin film was deposited by sol-gel method on thermally oxidized p-Si (2-5 Ω cm, ) substrates. The thin film was characterized by X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) to confirm the formation of nanocrystalline anatase titania and to determine the crystallite size (∼7 nm). The resistive sensor structure was fabricated employing two lateral Pd electrodes on top of the TiO2 sensing layer. The developed sensor was tested in the temperature range of 50-200 °C for the detection of low ppm acetone (0.5-50 ppm). The maximum response of ∼115% was obtained at 150 °C with response/recovery time of 14 s/22 s at 50 ppm acetone (in air). Moreover, the sensors were capable of detecting acetone as low as 0.5 ppm with acceptable response magnitude. As titania acetone sensors are mostly n-TiO2 based, the acetone sensing mechanism for p-TiO2 is yet to be established authentically. To address the issue, an equivalent circuit model, based on the corresponding band diagram of nanocrystalline p-TiO2 with Pd electrode, was developed to describe the electron transfer mechanism through grain, grain boundary and Pd electrode under the influence of acetone vapor.

  6. Evaluation of acetone vapors toxicity on Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae) eggs.

    Science.gov (United States)

    Pourmirza, Ali Asghr; Nasab, Fershteh Sadeghi; Zadeh, Abas Hossein

    2007-08-01

    The efficacy of acetone vapors against carefully aged eggs of Plodia interpunctella (Hubner) at 17+/-1 and 27+/-1 degrees C at different dosage levels of acetone over various exposure times was determined. Acetone was found to be toxic to Indian meal moth eggs. Considerable variation in the susceptibility of different age groups of eggs was apparent in the fiducial limits of the LD50 values. An inverse relationship between LD50 values and exposure times was observed in age groups of tested eggs. At 27+/-1 degrees C and 24 h exposure period, eggs aged 1-2 day-old were more tolerant to acetone than other age groups, followed by 0-1 day-old, 2-3 day-old and 3-4 day-old eggs. A similar pattern of susceptibility of eggs was observed at 72 h exposure. In all bioassays, eggs exposed to higher dosages of acetone developed at smaller rate. This was significant for the eggs, which were exposed to the highest dosage for 24 h. Increasing the temperature from 17+/-1 to 27+/-1 degrees C greatly increased the efficacy of acetone. At 27+/-1 degrees C eggs of P. interpunctella were killed by less than one-third of the dosage required for control at 17+/-1 degrees C. Acetone achieved 50% mortality with a dosage of 82.76 mg L(-1) in 1-2 day-old eggs at 27+/-1 degrees C. At this temperature hatching was retarded and greatly diminished when eggs aged 1-2 day-old were exposed to 80 mg L(-1) of acetone for the 24 h exposure period. There was no evidence of a hatch delay longer than the time spent under vapors for eggs exposed at 17+/-1 or 27+/-1 degrees C, indicating that some development must have occurred under fumigation.

  7. Molybdenum disulfide catalyzed tungsten oxide for on-chip acetone sensing

    Science.gov (United States)

    Li, Hong; Ahn, Sung Hoon; Park, Sangwook; Cai, Lili; Zhao, Jiheng; He, Jiajun; Zhou, Minjie; Park, Joonsuk; Zheng, Xiaolin

    2016-09-01

    Acetone sensing is critical for acetone leak detection and holds a great promise for the noninvasive diagnosis of diabetes. It is thus highly desirable to develop a wearable acetone sensor that has low cost, miniature size, sub-ppm detection limit, great selectivity, as well as low operating temperature. In this work, we demonstrate a cost-effective on-chip acetone sensor with excellent sensing performances at 200 °C using molybdenum disulfide (MoS2) catalyzed tungsten oxide (WO3). The WO3 based acetone sensors are first optimized via combined mesoscopic nanostructuring and silicon doping. Under the same testing conditions, our optimized mesoporous silicon doped WO3 [Si:WO3(meso)] sensor shows 2.5 times better sensitivity with ˜1000 times smaller active device area than the state-of-art WO3 based acetone sensor. Next, MoS2 is introduced to catalyze the acetone sensing reactions for Si:WO3(meso), which reduces the operating temperature by 100 °C while retaining its high sensing performances. Our miniaturized acetone sensor may serve as a wearable acetone detector for noninvasive diabetes monitoring or acetone leakage detection. Moreover, our work demonstrates that MoS2 can be a promising nonprecious catalyst for catalytic sensing applications.

  8. Investigating the Impact of Acetone Vapor Smoothing on the Strength and Elongation of Printed ABS Parts

    Science.gov (United States)

    Gao, Harry; Kaweesa, Dorcas V.; Moore, Jacob; Meisel, Nicholas A.

    2017-03-01

    Acetone vapor smoothing is a chemical treatment that "melts" the surface of additively manufactured acrylonitrile butadiene styrene parts. The process fuses layers together and allows them to reform when vapor is removed, resulting in a smooth surface finish. Although commonly used to improve aesthetics, recent work has begun to investigate the effects of vapor smoothing on part strength. Nevertheless, most of this work has failed to take into account the anisotropic nature of printed parts. Prior research has shown that vapor smoothing reduces strength under best-case loading conditions, when the tensile load is parallel with the direction of the layers. In this article, the authors hypothesize that vapor smoothing may increase strength under nonoptimal loading conditions as a result of increased cohesion between layers and a reduction in stress concentrations. They use a design of experiments approach to identify the combined impact of printing and vapor smoothing parameters on part material properties.

  9. Polypyrrole nanoparticles fabricated via Triton X-100 micelles template approach and their acetone gas sensing property

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fake; Li, Hang [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Jiang, Hongmin [26th Research Institute, Chinese Electronics Scientific and Technical Group Company, Chongqing 400060 (China); Zhang, Kejun; Chang, Kai; Jia, Shuangrong; Jiang, Wenbin; Shang, Ya; Lu, Weiping [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Deng, Shaoli, E-mail: dengsl072@yahoo.com.cn [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Chen, Ming, E-mail: chenming1971@yahoo.com [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China)

    2013-09-01

    Nano-scaled polypyrrole (PPy) particles have been successfully synthesized with the help of Triton X-100 micelles via soft template approach. The polypyrrole nanoparticles have been spin-coated on surface acoustic wave (SAW) transducers to demonstrate their sensing capability toward acetone gas exposure. Field Emission Scanning Electron Microscopes (FE-SEM) and Fourier transform infrared (FT-IR) spectroscopy have been utilized to characterize these PPy nanoparticles. The PPy nanoparticles have an average diameter of 95 nm. The responses of the sensors are linearly associated with the acetone concentrations in the range from 5.5 ppm to 80 ppm. In response to 5.5 ppm acetone exposure, the response and recovery time are 9 s and 8.3 s, respectively. SAW sensors coated with PPy nanoparticles were potentially useful to detect acetone.

  10. Sensing performances to low concentration acetone for palladium doped LaFeO3 sensors

    Institute of Scientific and Technical Information of China (English)

    王小风; 秦宏伟; 裴金亮; 陈艳平; 李玲; 谢继浩; 胡季帆

    2016-01-01

    The PdCl2 was mixed with nanocrystalline powders LaFeO3 and subsequently followed by an annealing of 800 °C. PdO phase was formed and almost distributed uniformly on the surface of LaFeO3 nano-particles. With an increase of PdO amounts in composite powders, sensing sensitivityRg/Ra to low concentration acetone or ethanol for Pd doped LaFeO3 sensors increased at first, underwent the maximum with 2 wt.% PdCl2 dopant, and then doped again. Interestingly, appropriate Pd doping in LaFeO3 changed the selectivity behavior of gas sensing. LaFeO3 sensor showed good selectivity to ethanol, but 2 wt.% Pd doped LaFeO3 sensor showed good selectivity to acetone. The sensitivity for LaFeO3 at 200 °C was 1.32 to 1 ppm ethanol, and 1.19 to 1 ppm acetone. Whereas the sensitivity for 2 wt.% Pd doped LaFeO3 at 200 °C was 1.53 to 1 ppm ethanol, and 1.9 to 1 ppm acetone. The 2 wt.% Pd doped LaFeO3 sensor at 200 °C showed very short response time (4 s) and recovery time (2 s) to 1 ppm acetone gas, respectively. Such results showed that 2 wt.% Pd doped LaFeO3 sensor is a new promising sensing candidate for detecting low concentration acetone.

  11. Acetone gas sensing mechanism on zinc oxide surfaces: A first principles calculation

    Science.gov (United States)

    Sadeghian Lemraski, M.; Nadimi, E.

    2017-03-01

    Semiconducting metal oxide gas sensors have attracted growing interest as a result of their outstanding performance in the bio and industrial applications. Nevertheless, the sensing mechanism is yet not totally understood. In this study, we extensively investigate the adsorption mechanism of acetone molecule on ZnO-based thin film sensors by performing ab initio density functional theory calculations and employing quantum molecular dynamic simulations. Since the sensitivity of a metal oxide sensor is exceedingly depends on molecular oxygen exposure and operating temperature, we explore the competitive adsorption of acetone and oxygen molecule on the most stable orientation of ZnO surface (10 1 ̅ 0) at different temperatures. Results indicate that at elevated temperatures acetone gains required thermal energy to remove preadsorbed oxygen molecule from the surface in a competitive process. We will show that this competition is responsible for the resistive switching behavior in the ZnO-based gas sensors.

  12. Vapor Sensing Theoretical Study on Optical Microcavities

    Institute of Scientific and Technical Information of China (English)

    ZHANG Le-xin; ZHANG Ran; LI Zhi-quan

    2007-01-01

    When the organic vapors absorbed to the surface of porous silicon(PS), capillary condensation takes place due to the porous structure of the PS layer, accordingly resulting in the effective refractive index changing. For PS multi-layer microcavities, the different resonant peaks shift in the reflectivity spectrum of porous silicon microcavities(PSMs). The optical sensing model is set up by applying Bruggeman effective medium approximation theory, capillary condensation process and transfer matrix theoretically analytical method of one-dimensional photonic crystals. At the same time, comprehensively researched on are the sensing characteristics of PSMs which are exposed to give concentration organic vapors. At last, made is the theoretical simulation for sensing model of the PSMs in case of saturation by using computer numerical calculation, and found is the linearity relation between the refractive index of organic solvent and the peak-shift. At the same time deduced is the peak-shift as a function of the concentration of ethanol vapors.

  13. Effect of Gold Dispersion on the Photocatalytic Activity of Mesoporous Titania for the Vapor-Phase Oxidation of Acetone

    Directory of Open Access Journals (Sweden)

    S. V. Awate

    2008-01-01

    Full Text Available Mesostructured titanium dioxide photocatalyst, having uniform crystallite size (6–12 nm and average pore diameter of ∼4.2 nm, was synthesized by using a low-temperature nonsurfactant hydrothermal route, employing tartaric acid as a templating agent. Gold additions from 0.5 to 2 wt% were incorporated, either during the hydrothermal process or by postsynthesis wet impregnation. Compared to the impregnation-prepared samples, the samples synthesized hydrothermally contained smaller-size (≤1 nm gold clusters occluded in the pores of the host matrix. Whereas CO2 and H2O were the main reaction products in UV-assisted vapor-phase oxidation of acetone using these catalysts, C2H6 and HCO2CH3 were also produced for higher acetone concentrations in air. The conversion of acetone was found to increase with decrease in the size of both TiO2 and gold particles. In situ IR spectroscopy revealed that titania and gold particles serve as independent adsorption and reaction sites for acetone and oxygen molecules. Acetone molecules adsorb exclusively at TiO2 surface, giving rise to a strongly adsorbed (condensed state as well as to the formation of formate- and methyl formate-type surface species. Hydroxyl groups at titania surface participate directly in these adsorption steps. Nanosize gold particles, on the other hand, were primarily responsible for the adsorption and activation of oxygen molecules. Mechanistic aspects of the photochemical processes are discussed on the basis of these observations.

  14. Influence of Ce doping on microstructure of ZnO nanoparticles and their acetone sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, F.M.; Li, X.B. [College of Physics and Electronic Engineering, Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, Northwest Normal University, Lanzhou, Gansu 730070 (China); National Laboratory of Solid State Microstructures & Eco-Materials and Renewable Energy Research Center (ERERC) at Department of Physics, Nanjing University, Nanjing 210093 (China); Ma, S.Y., E-mail: lifaming1108074@sina.com [College of Physics and Electronic Engineering, Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, Northwest Normal University, Lanzhou, Gansu 730070 (China); Chen, L.; Li, W.Q.; Zhu, C.T.; Xu, X.L. [College of Physics and Electronic Engineering, Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, Northwest Normal University, Lanzhou, Gansu 730070 (China); Chen, Y. [Northwest University for Nationality, Lanzhou, Gansu 730030 (China); Li, Y.F.; Lawson, G. [Atech Systems, 6110 W. Highway 290, Austin, TX 78735 (United States)

    2015-11-15

    Electrospinning technology was generally used to synthesis nanofiber, here we use it to fabricate pure ZnO nanoparticles (ZnO NPs) and Ce-doped (0.1 wt%, 0.8 wt%, 1.5 wt%) ZnO nanoparticles (ZnO:Ce NPs) via decrease the molecular weight of PVP in precursor liquid. Their microstructures were characterized by X-ray diffraction, scanning electron microscopy, Brunauer-Emmet-Teller and photoluminescence spectra. The results clearly indicated that the 0.8 wt% ZnO:Ce NPs shows smaller average grain size (70 nm) and a higher specific surface area (21.5 m{sup 2}/g). The testing on gas sensing performance revealed that the 0.8 wt% ZnO:Ce NPs based sensor shows the highest response values and a well selectivity to acetone. The response and recovery time of ZnO NPs based sensors to 100 ppm acetone was about 13 and 7 s while these are about 10 and 9 s in ZnO:Ce NPs based sensors, respectively. These results demonstrated that the 0.8 wt% ZnO:Ce NPs based sensor can rapidly be detect and distinguish accurately acetone in ambient air. Moreover, the sensor shows good long-term stability and reproducibility of response. The sensing mechanism was also discussed and the results indicated that the gas diffusing channels and the electron depleted layer of the ZnO NPs based sensor was increased markedly after Ce-doped, which results in the response of the ZnO:Ce NPs based sensor increased. - Highlights: • The loose mesostructured provide more channel for gas diffusion. • Smaller average grain size (70 nm) and higher specific surface area (21.5 m{sup 2}/g). • The response and recovery time of ZnO:Ce NPs based sensor was about 10 and 9 s. • Suitable Ce-doped could improve the response of the ZnO NPs base sensors.

  15. Conducting Graphite/Cellulose Composite Film as a Candidate for Chemical Vapor-Sensing Material

    Directory of Open Access Journals (Sweden)

    Kaihua Liu

    2014-07-01

    Full Text Available A type of conductive graphite/cellulose composite film used for chemical vapor-sensing material was prepared at room temperature in the ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIm]Cl. Graphite was pretreated with both oxidation and reduction processes. Due to the use of N,N-carbonyldiimidazole (CDI, as a covalent cross-linking agent in [BMIm]Cl, there were limited chemical bonds between the graphite and cellulose. The composite film was analyzed using Fourier transform infrared spectroscopy (FT-IR, Raman spectroscopy, and X-ray photoelectron spectroscopy (XRD. When these conducting films were exposed to certain organic vapors, their electrical resistances quickly changed, showing gas sensitivity. The percolation threshold of the conducting film was about 5 wt%. The gas-sensing behavior of these films in solvent were the opposite of those gas-sensing materials based on a non-polar polymer matrix. A typical negative vapor coefficient (NVC was observed when the film was placed in polar organic solvents such as methanol, ethanol, and acetone.

  16. 2D Sn-doped ZnO ultrathin nanosheet networks for enhanced acetone gas sensing application

    KAUST Repository

    Al-Hadeethi, Yas

    2016-11-10

    In this paper, we report the synthesis, characterizations and gas sensing application of 2D Sn-doped ZnO ultrathin nanosheet networks synthesized by a simple and facile hydrothermal process. The synthesized nanosheets were characterized using several techniques in terms of their morphological, structural, optical and compositional properties. The detailed characterizations confirmed that the nanosheets are pure, grown in high-density, possessing well-crystalline wurtzite hexagonal phase and exhibiting good optical properties. Further, the synthesized nanosheets were used as functional material to develop nanosensor device by coating it on the alumina substrate with suitable electrodes. The fabricated sensor device was tested towards acetone gas which exhibited a maximum sensitivity of 5.556 (Ra/Rg) for 200 ppm of acetone at 320 °C.

  17. 丙酮肟甲醚饱和蒸气压测定及关联%Vapor Pressure Measurement and Correlation of Acetone Oxime Methyl Ether

    Institute of Scientific and Technical Information of China (English)

    叶长燊; 董佳; 李玲

    2013-01-01

      采用动态法,利用Rose釜测定了丙酮肟甲醚在307.75~344.05 K的饱和蒸气压,并应用Antoine方程进行关联,获得Antoine常数A、B、C分别为20.64,2338.72和−88.86,Antoine方程计算值与饱和蒸气压实验测定值之间的平均相对误差为0.45%.在此基础上,通过Clausius-Clapeyron方程计算得到丙酮肟甲醚在307.75~344.05 K温度范围内的平均摩尔蒸发热为36479.24 kJ⋅kmol−1.所得饱和蒸气压方程对丙酮肟甲醚精馏分离过程的设计与操作具有重要意义.%Saturated vapor pressures of acetone oxime methyl ether(AOME) were measured in the temperature range of 307.75~344.05 K by dynamic method in a Rose still. The measured saturated vapor pressures and temperatures were correlated by Antoine equation and the constants of equation were determinated as A=20.64, B = 2338.72, and C = −88.86 by nonlinear regression method. The averaged relative error between saturated vapor pressures calculated from the Antoine equation and the experimental data is 0.45%. Based on the experimental data of vapor pressures, the latent heat of vaporization of acetone oxime methyl ether was also obtained by Clausius-Clapeyron equation and its value is 36479.24 kJ⋅kmol−1 in the temperature range of 307.75~344.05 K. It is very important to provide the Antoine constants and latent heat of acetone oxime methyl ether for the design and operation of its distillation separation process.

  18. Nickel oxide nanowires: vapor liquid solid synthesis and integration into a gas sensing device.

    Science.gov (United States)

    Kaur, N; Comini, E; Zappa, D; Poli, N; Sberveglieri, G

    2016-05-20

    In the field of advanced sensor technology, metal oxide nanostructures are promising materials due to their high charge carrier mobility, easy fabrication and excellent stability. Among all the metal oxide semiconductors, nickel oxide (NiO) is a p-type semiconductor with a wide band gap and excellent optical, electrical and magnetic properties, which has not been much investigated. Herein, we report the growth of NiO nanowires by using the vapor liquid solid (VLS) technique for gas sensing applications. Platinum, palladium and gold have been used as a catalyst for the growth of NiO nanowires. The surface morphology of the nanowires was investigated through scanning electron microscopy to find out which catalyst and growth conditions are best for the growth of nanowires. GI-XRD and Raman spectroscopies were used to confirm the crystalline structure of the material. Different batches of sensors have been prepared, and their sensing performances towards different gas species such as carbon monoxide, ethanol, acetone and hydrogen have been explored. NiO nanowire sensors show interesting and promising performances towards hydrogen.

  19. 1-Butyl-3-Methylimidazolium Tetrafluoroborate Film as a Highly Selective Sensing Material for Non-Invasive Detection of Acetone Using a Quartz Crystal Microbalance

    Directory of Open Access Journals (Sweden)

    Wenyan Tao

    2017-01-01

    Full Text Available Breath acetone serves as a biomarker for diabetes. This article reports 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4], a type of room temperature ionic liquid (RTIL, as a selective sensing material for acetone. The RTIL sensing layer was coated on a quartz crystal microbalance (QCM for detection. The sensing mechanism is based on a decrease in viscosity and density of the [bmim][BF4] film due to the solubilization of acetone leading to a positive frequency shift in the QCM. Acetone was detected with a linear range from 7.05 to 750 ppmv. Sensitivity and limit of detection were found to be 3.49 Hz/ppmv and 5.0 ppmv, respectively. The [bmim][BF4]-modified QCM sensor demonstrated anti-interference ability to commonly found volatile organic compounds in breath, e.g., isoprene, 1,2-pentadiene, d-limonene, and dl-limonene. This technology is useful for applications in non-invasive early diabetic diagnosis.

  20. 1-Butyl-3-Methylimidazolium Tetrafluoroborate Film as a Highly Selective Sensing Material for Non-Invasive Detection of Acetone Using a Quartz Crystal Microbalance

    Science.gov (United States)

    Tao, Wenyan; Lin, Peng; Liu, Sili; Xie, Qingji; Ke, Shanming; Zeng, Xierong

    2017-01-01

    Breath acetone serves as a biomarker for diabetes. This article reports 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), a type of room temperature ionic liquid (RTIL), as a selective sensing material for acetone. The RTIL sensing layer was coated on a quartz crystal microbalance (QCM) for detection. The sensing mechanism is based on a decrease in viscosity and density of the [bmim][BF4] film due to the solubilization of acetone leading to a positive frequency shift in the QCM. Acetone was detected with a linear range from 7.05 to 750 ppmv. Sensitivity and limit of detection were found to be 3.49 Hz/ppmv and 5.0 ppmv, respectively. The [bmim][BF4]-modified QCM sensor demonstrated anti-interference ability to commonly found volatile organic compounds in breath, e.g., isoprene, 1,2-pentadiene, d-limonene, and dl-limonene. This technology is useful for applications in non-invasive early diabetic diagnosis. PMID:28117697

  1. Hybrid Vapor Stripping-Vapor Permeation Process for Recovery and Dehydration of 1-Butanol and Acetone/Butanol/Ethanol from Dilute Aqueous Solutions. Part 1. Process Simulations

    Science.gov (United States)

    BACKGROUND: Fermentative production of butanol is limited to low concentrations, typically less than 2 wt% solvent, due to product inhibition. The result is high separation energy demand by conventional distillation approaches, despite favorable vapor-liquid equilibrium and parti...

  2. Single-step synthesis of In{sub 2}O{sub 3} nanowires decorated with TeO{sub 2} nanobeads and their acetone-sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sunghoon; Kheel, Hyejoon; Sun, Gun-Joo; Lee, Chongmu [Inha University, Department of Materials Science and Engineering, Incheon (Korea, Republic of); Park, Sang Eon [Inha University, Department of Chemistry, Incheon (Korea, Republic of)

    2016-04-15

    In{sub 2}O{sub 3} nanowires decorated with TeO{sub 2} nanobeads were synthesized by a facile single-step thermal evaporation process, and their acetone-gas-sensing properties were examined. The diameters and lengths of the In{sub 2}O{sub 3} nanowires ranged from 10 to 20 nm and up to 100 μm, respectively, whereas the diameters of the TeO{sub 2} beads ranged from 50 to 200 nm. The TeO{sub 2}-decorated In{sub 2}O{sub 3} nanowire sensor showed stronger response to acetone gas than the pristine In{sub 2}O{sub 3} nanowire sensor. The pristine and TeO{sub 2}-decorated In{sub 2}O{sub 3} nanowires exhibited sensitivity of ∝10.13 and ∝24.87, respectively, to 200 ppm acetone at 300 C. The decorated nanowire sensor also showed much more rapid response and recovery than the latter. Both sensors showed the strongest response to acetone gas at 300 C, respectively. The mechanism and origin of the enhanced acetone-gas-sensing performance of the TeO{sub 2}-decorated In{sub 2}O{sub 3} nanowire sensor compared to the pristine In{sub 2}O{sub 3} nanowire sensor were discussed in detail. The enhanced sensing performance of the TeO{sub 2}-decorated In{sub 2}O{sub 3} nanowire is mainly due to the modulation of the potential barrier height at the TeO{sub 2}-In{sub 2}O{sub 3} interface, high catalytic activity of TeO{sub 2,} and creation of active adsorption sites by incorporation of TeO{sub 2}. (orig.)

  3. Polymer functionalized nanostructured porous silicon for selective water vapor sensing at room temperature

    Science.gov (United States)

    Dwivedi, Priyanka; Das, Samaresh; Dhanekar, Saakshi

    2017-04-01

    This paper highlights the surface treatment of porous silicon (PSi) for enhancing the sensitivity of water vapors at room temperature. A simple and low cost technique was used for fabrication and functionalization of PSi. Spin coated polyvinyl alcohol (PVA) was used for functionalizing PSi surface. Morphological and structural studies were conducted to analyze samples using SEM and XRD/Raman spectroscopy respectively. Contact angle measurements were performed for assessing the wettability of the surfaces. PSi and functionalized PSi samples were tested as sensors in presence of different analytes like ethanol, acetone, isopropyl alcohol (IPA) and water vapors in the range of 50-500 ppm. Electrical measurements were taken from parallel aluminium electrodes fabricated on the functionalized surface, using metal mask and thermal evaporation. Functionalized PSi sensors in comparison to non-functionalized sensors depicted selective and enhanced response to water vapor at room temperature. The results portray an efficient and selective water vapor detection at room temperature.

  4. Au-modified three-dimensional In2O3 inverse opals: synthesis and improved performance for acetone sensing toward diagnosis of diabetes

    Science.gov (United States)

    Xing, Ruiqing; Li, Qingling; Xia, Lei; Song, Jian; Xu, Lin; Zhang, Jiahuan; Xie, Yi; Song, Hongwei

    2015-07-01

    Analyzing the volatile organic compounds (VOCs) in exhaled breath effectively is crucial to medical treatment, which can provide a fast and noninvasive way to diagnose disease. Well-designed materials with controlled structures have great influence on the sensing performance. In this work, the ordered three dimensional inverse opal (3DIO) macroporous In2O3 films with additional via-hole architectures were fabricated and different amounts of gold nanoparticles (Au NPs) were loaded on the In2O3 films aiming at enhancing their electrical responses. The gas sensing to acetone toward diabetes diagnosis in exhaled breath was performed with different Au/In2O3 electrodes. Representatively, the best 3DIO Au/In2O3 sensor can detect acetone effectively at 340 °C with response of 42.4 to 5 ppm, the actual detection limit is as low as 20 ppb, and it holds a dynamic response of 11 s and a good selectivity. Moreover, clinical tests proved that the as-prepared 3DIO Au/In2O3 IO sensor could distinguish acetone biomarkers in human breath clearly. The excellent gas sensing properties of the Au/In2O3 electrodes were attributed to the ``spillover effects'' between Au and In2O3 and the special 3DIO structure. This work indicates that 3DIO Au/In2O3 composite is a promising electrode material for actual application in the monitoring and detection of diabetes through exhaled breath.Analyzing the volatile organic compounds (VOCs) in exhaled breath effectively is crucial to medical treatment, which can provide a fast and noninvasive way to diagnose disease. Well-designed materials with controlled structures have great influence on the sensing performance. In this work, the ordered three dimensional inverse opal (3DIO) macroporous In2O3 films with additional via-hole architectures were fabricated and different amounts of gold nanoparticles (Au NPs) were loaded on the In2O3 films aiming at enhancing their electrical responses. The gas sensing to acetone toward diabetes diagnosis in exhaled

  5. REMOTE SENSING OF WATER VAPOR CONTENT USING GROUND-BASED GPS DATA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Spatial and temporal resolution of water vapor content is useful in improving the accuracy of short-term weather prediction.Dense and continuously tracking regional GPS arrays will play an important role in remote sensing atmospheric water vapor content.In this study,a piecewise linear solution method was proposed to estimate the precipitable water vapor (PWV) content from ground-based GPS observations in Hong Kong.To evaluate the solution accuracy of the water vapor content sensed by GPS,the upper air sounding data (radiosonde) that are collected locally was used to calculate the precipitable water vapor during the same period.One-month results of PWV from both ground-based GPS sensing technique and radiosonde method are in agreement within 1~2 mm.This encouraging result will motivate the GPS meteorology application based on the establishment of a dense GPS array in Hong Kong.

  6. Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing

    Science.gov (United States)

    Piszter, Gábor; Kertész, Krisztián; Bálint, Zsolt; Biró, László Péter

    2016-01-01

    Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings. PMID:27618045

  7. Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing

    Directory of Open Access Journals (Sweden)

    Gábor Piszter

    2016-09-01

    Full Text Available Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings.

  8. Hybrid Vapor Stripping-Vapor Permeation Process for Recovery and Dehydration of 1-Butanol and Acetone/Butanol/Ethanol from Dilute Aqueous Solutions. Part 2. Experimental Validation with Simple Mixtures and Actual Fermentation Broth

    Science.gov (United States)

    BACKGROUND: In Part1 of this work, a process integrating vapor stripping, vapor compression, and a vapor permeation membrane separation step, Membrane Assisted Vapor Stripping (MAVS), was predicted to produce energy savings compared to traditional distillation systems for separat...

  9. Spectroscopy underlying microwave remote sensing of atmospheric water vapor

    Science.gov (United States)

    Tretyakov, M. Yu.

    2016-10-01

    The paper presents a spectroscopist's view on the problem of recovery of the atmosphere humidity profile using modern microwave radiometers. Fundamental equations, including the description of their limitations, related to modeling of atmospheric water vapor absorption are given. A review of all reported to date experimental studies aimed at obtaining corresponding numerical parameters is presented. Best estimates of these parameters related to the Voigt (Lorentz, Gross, Van Vleck - Weisskopf and other equivalent) profile based modeling of the 22- and 183-GHz water vapor diagnostic lines and to non-resonance absorption as well as corresponding uncertainties are made on the basis of their comparative analysis.

  10. 丙酮-水-丙酮连氮体系汽液平衡测定与关联%Measurement and correlation of vapor-liquid equilibria for acetone-water-azine system

    Institute of Scientific and Technical Information of China (English)

    李柏春; 王琮; 黄岩; 张文林

    2013-01-01

    Vapor-liquid equilibrium (VLE) data for acetone-azine binary system and parts of acetone water azine ternary system were determined in an Othmer equilibrium at atmospheric pressure (101.3 kPa). The experimental data was verified by Herington method and were consistent with thermodynamics. The data of acetone-azine binary system were correlated with the NRTL,Wilson and UNIQUAC models by using chemical engineering analogue software. Respectively,all the models were correlated well with the VLE data. NRTL model produced best data,with the average deviations of temperature of 0.0639 K and vapor-phase mole fraction of methanol of 0.0048. The NRTL model was used to correlate the VLE data of the ternary system,and the interaction parameters of acetone-azine,water-azine,and acetone-water were obtained. In order to verify the reliability of the VLE data of the ternary system and these interacting binary parameters,the vapor compositions were calculated and compared with the corresponding experimental VLE data of acetone-azine binary system. The agreement between the calculated and experimental data was satisfactory. The experimental and correlative data could provide a basis for distillation separation of acetone-water-azine’s VLE system.%采用汽液双循环平衡釜,在常压(101.3 kPa)下测定了丙酮-丙酮连氮二元组分物系以及部分丙酮-水-丙酮连氮三元组分物系的汽液平衡数据。实验数据经Herington面积积分法检验符合热力学一致性。通过化工过程模拟软件,分别采用 Wilson、NRTL、UNIQUAC 活度系数模型对丙酮-丙酮连氮二元组分物系实验数据进行关联得到模型参数。并对汽液平衡的计算值与实验值进行比较,3种模型都吻合良好,其中由NRTL方程关联得到的计算结果最为适合,平均温度偏差和汽相组成偏差分别为0.0639 K和0.0048。从三元汽液相平衡数据中拟合出了丙酮-丙酮连氮、丙酮-

  11. Temperature and saturation dependence in the vapor sensing of butterfly wing scales

    Energy Technology Data Exchange (ETDEWEB)

    Kertész, K., E-mail: kertesz.krisztian@ttk.mta.hu [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, 1525 Budapest, PO Box 49 (Hungary); Piszter, G. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, 1525 Budapest, PO Box 49 (Hungary); Jakab, E. [Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, H-1525 Budapest, P O Box 17 (Hungary); Bálint, Zs. [Hungarian Natural History Museum, H-1088, Budapest, Baross utca 13 (Hungary); Vértesy, Z.; Biró, L.P. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, 1525 Budapest, PO Box 49 (Hungary)

    2014-06-01

    The sensing of gasses/vapors in the ambient air is the focus of attention due to the need to monitor our everyday environment. Photonic crystals are sensing materials of the future because of their strong light-manipulating properties. Natural photonic structures are well-suited materials for testing detection principles because they are significantly cheaper than artificial photonic structures and are available in larger sizes. Additionally, natural photonic structures may provide new ideas for developing novel artificial photonic nanoarchitectures with improved properties. In the present paper, we discuss the effects arising from the sensor temperature and the vapor concentration in air during measurements with a photonic crystal-type optical gas sensor. Our results shed light on the sources of discrepancy between simulated and experimental sensing behaviors of photonic crystal-type structures. Through capillary condensation, the vapors will condensate to a liquid state inside the nanocavities. Due to the temperature and radius of curvature dependence of capillary condensation, the measured signals are affected by the sensor temperature as well as by the presence of a nanocavity size distribution. The sensing materials used are natural photonic nanoarchitectures present in the wing scales of blue butterflies. - Highlights: • We report optical gas sensing on blue butterfly wing scale nanostructures. • The sample temperature decrease effects a reversible break-down in the measured spectra. • The break-down is connected with the vapor condensation in the scales and wing surface. • Capillary condensation occurs in the wing scales.

  12. Ammonia vapor sensing properties of polyaniline-titanium(IV)phosphate cation exchange nanocomposite.

    Science.gov (United States)

    Khan, Asif Ali; Baig, Umair; Khalid, Mohd

    2011-02-28

    In this study, the electrically conducting polyaniline-titanium(IV)phosphate (PANI-TiP) cation exchange nanocomposite was synthesized by sol-gel method. The cation exchange nanocomposite based sensor for detection of ammonia vapors was developed at room temperature. It was revealed that the sensor showed good reversible response towards ammonia vapors ranging from 3 to 6%. It was found that the sensor with p-toluene sulphonic acid (p-TSA) doped exhibited higher sensing response than hydrochloric acid doped. This sensor has detection limit ≤1% ammonia. The response of resistivity changes of the cation exchange nanocomposite on exposure to different concentrations of ammonia vapors shows its utility as a sensing material. These studies suggest that the cation exchange nanocomposite could be a good material for ammonia sensor at room temperature.

  13. Measurement and correlation of vapor-liquid equilibria for dichloromethane-methanol-acetone-water system%二氯甲烷-甲醇-丙酮-水体系汽液平衡测定和关联

    Institute of Scientific and Technical Information of China (English)

    邵少花; 顾正桂

    2012-01-01

    In the chemical and medicine industry,the dichloromethane-methanol-acetone-water quaternary system is commonly existed in the liquid waste. It is essential of the vapor-liquid equilibrium ( VLE ) data for this system to recover them by separating process. Isobaric VLE data on the six pairs of binary mixtures of dichloromethane, methanol, acetone and water were determined with single stage vapor-liquid equilibrium still at atmospheric pressure. The result shows that the thermodynamic consistency of the experimental data is satisfied by means of point to point method. In the experiment, the vapor-liquid phase compositions were analyzed by using SP-6800 gas chromatograph. Six pairs of correlation parameters of Wilson model and the calculated values of vapor-phase compositions were observed by using non-linear least square method procedure of Matlab. Besides, the vapor-liquid equilibria in this quaternary system were measured experimentally at 100 kPa, correlated by the six pairs of model parameters, and compared with the experimental data. The results obtained show that the absolute deviation of experiment and calculation is less than 0. 05. It means that the Wilson model is reliable for the prediction and correlation of the VLE data of the dichloromethane-methanol-acetone-water quaternary system as to its exact fitting accuracy. The experimental and correlative data can provide a basis for extractive distillation separation of dichloromethane-methanol-acetone-water system.%二氯甲烷-甲醇-丙酮-水四元体系常见于化工、医药等行业生产的废液中,该体系分离回收的前提是进行汽液平衡数据的测定.现利用单级循环汽液平衡釜测定了二氯甲烷、甲醇、丙酮、水混合液中的6组二元体系在常压下的汽液平衡数据,同时对其进行了点对点法热力学一致性校验.实验中采用SP-6800型气相色谱仪分析汽液相组成,并运用Matlab中的非线性最小二乘法分别关联6

  14. Remotely sensed water vapor variations during CLEOPATRA `92

    Energy Technology Data Exchange (ETDEWEB)

    Meischner, P.F. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Kiemle, C. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Ehret, G. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Kaestner, M. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Schreiber, H.G. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Evtushenko, A.V. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Inst. Radiotekhniki i Ehlektroniki; Kutuza, B.G. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Inst. Radiotekhniki i Ehlektroniki; Petrenko, B.Z. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Inst. Radiotekhniki i Ehlektroniki; Smirnov, M.T. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Inst. Radiotekhniki i Ehlektroniki

    1994-11-01

    Total atmospheric water vapor contents have been measured during CLEOPATRA `92 using different methods. A multifrequency microwave radiometer system from IRE, Moskow operated from ground and an airborne DIAL system, DLR, performed measurements above the radiometer site. The results compare well if the atmosphric conditions are sufficiently homogeneous in the mesoscale and complement in a high space resolution for the DIAL measurements and a high time resolution of the microwave system. Under these conditions both measurement results further agree with radiosoundings and aircraft in situ measurements within the estimated measurement errors. Coordinated observations by the different systems with high time and high space resolution open a good change to separate between transports caused by advection or convection. Microwave radiometer measurements from ground are best suited for monitoring long term trends as well as fast fluctuations, whereas the DIAL measurements give more detailed insight in the diffusion processes within the atmospheric boundary layer ABL. The measurements on May 29 very impressively show the moisture fluxes from local lakes into the ABL. The observations support the ABL to act as a flux-averaging medium, thus contributing naturally to an upscaling which improves the use of remote measurements from space for the estimation of area averaged moisture fluxes. (orig.)

  15. Remotely sensed water vapor variations during CLEOPATRA `92

    Energy Technology Data Exchange (ETDEWEB)

    Meischner, P.F. [Inst. fuer Physik der Atmosphaere, DLR Oberpfaffenhofen, Wessling (Germany); Kiemle, C. [Inst. fuer Physik der Atmosphaere, DLR Oberpfaffenhofen, Wessling (Germany); Ehret, G. [Inst. fuer Physik der Atmosphaere, DLR Oberpfaffenhofen, Wessling (Germany); Kaestner, M. [Inst. fuer Physik der Atmosphaere, DLR Oberpfaffenhofen, Wessling (Germany); Schreiber, H.G. [Inst. fuer Physik der Atmosphaere, DLR Oberpfaffenhofen, Wessling (Germany); Evtushenko, A.V. [Inst. of Radioengineering and Electronics, RAS, Moscow (Russian Federation); Kutuza, B.G. [Inst. of Radioengineering and Electronics, RAS, Moscow (Russian Federation); Petrenko, B.Z. [Inst. of Radioengineering and Electronics, RAS, Moscow (Russian Federation); Smirnov, M.T. [Inst. of Radioengineering and Electronics, RAS, Moscow (Russian Federation)

    1994-11-01

    Total atmospheric water vapor contents have been measured during CLEOPATRA `92 using different methods. A multifrequency microwave radiometer system from IRE, Moskow operated from ground and an airborne DIAL system, DLR, performed measurements above the radiometer site. The results compare well if the atmospheric conditions are sufficiently homogeneous in the mesoscale and complement in a high space resolution for the DIAL measurements and a high time resolution of the microwave system. Under these conditions both measurement results further agree with radiosoundings and aircraft in situ measurements within the estimated measurement errors. Coordinated observations by the different systems with high time and high space resolution open a good chance to separate between transports caused by advection or convection. Microwave radiometer measurements from ground are best suited for monitoring long term trends as well as fast fluctuations, whereas the DIAL measurements give more detailed insight in the diffusion processes within the atmospheric boundary layer ABL. The measurement on May 29 very impressively show the moisture fluxes from local lakes into the ABL. The observations support the ABL to act as a flux-averaging medium, thus contributing naturally to an upscaling which improves the use of remote measurements from space for the estimation of area averaged moisture fluxes. (orig.) [Deutsch] Der Gesamtsaeulenwassergehalt der Atmosphaere wurde waehrend CLEOPATRA `92 aus verschiedenen Messmethoden bestimmt. Ein Mehrfrequenz-Mikrowellenradiometersystem des IRE, Moskau hat vom Boden aus gemessen, waehrend mit einem flugzeuggetragenen DIAL System der DLR ueber dem Mikrowellensystem nach unten gemessen wurde. Die Messergebnisse sind gut vergleichbar bei mesoskalig homogenen Bedingungen und ergaenzen sich gut, was die hohe zeitliche Aufloesung der Radiometer und die hohe raeumliche Aufloesung des DIALs betrifft. Auch mit den Ergebnissen von Radiosondenmessungen und den

  16. Functionalized bioinspired microstructured optical fiber pores for applications in chemical vapor sensing

    Science.gov (United States)

    Calkins, Jacob A.

    Chemical vapor sensing for defense, homeland security, environmental, and agricultural application is a challenge, which due combined requirements of ppt sensitivity, high selectivity, and rapid response, cannot be met using conventional analytical chemistry techniques. New sensing approaches and platforms are necessary in order to make progress in this rapidly evolving field. Inspired by the functionalized nanopores on moth sensilla hairs that contribute to the high selectivity and sensitivity of this biological system, a chemical vapor sensor based on the micro to nanoscale pores in microstructured optical fibers (MOFs) was designed. This MOF based chemical vapor sensor design utilizes MOF pores functionalized with organic self-assembled monolayers (SAMs) for selectivity and separations and a gold plasmonic sensor for detection and discrimination. Thin well-controlled gold films in MOF pores are critical components for the fabrication of structured plasmonic chemical vapor sensors. Thermal decomposition of dimethyl Au(II) trifluoroacetylacetonate dissolved in near-critical CO2 was used to deposit gold island films within the MOF pores. Using a 3mercatopropyltrimethoxysilane adhesion layer, continuous gold thin films as thin as 20--30 nm were deposited within MOF pores as small as 500 nm in diameter. The gold island films proved to be SERS active and were used to detect 900 ppt 2,4 DNT vapor in high pressure nitrogen and 6 ppm benzaldehyde. MOF based waveguide Raman (WGR), which can probe the air/silica interface between a waveguiding core and surrounding pores, was developed to detect and characterize SAMs and other thin films deposited in micro to nanoscale MOF pores. MOF based WGR was used to characterize an octadecyltrichlorosilane (OTS) SAM deposited in 1.6 mum diameter pores iv to demonstrate that the SAM was well-formed, uniform along the pore length, and only a single layer. MOF based WGR was used to detect a human serum albumin monolayer deposited on the

  17. Chemical sensing of copper phthalocyanine sol-gel glass through organic vapors

    Energy Technology Data Exchange (ETDEWEB)

    Ridhi, R.; Gawri, Isha; Abbas, Saeed J.; Saini, G. S. S.; Tripathi, S. K. [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh-160 014 (INDIA) Fax: +91-172-2783336; Tel.:+91-172-2544362 (India)

    2015-05-15

    The sensitivities of metallophthalocyanine to vapor phase electron donors has gained significance in many areas and disciplines due to their sensing properties and ease of operation. In the present study the interaction mechanism of organic vapors in Copper Phthalocyanine (CuPc) sol-gel glass has been studied. The interaction mechanism is affected by many factors like morphology, electrical or optical properties of film. CuPc sol-gel glass has been synthesized using chemical route sol-gel method. Its structural characterization was conducted using XRD and the amorphous nature of the silicate glass was observed with characteristic α polymorph phase of CuPc at around 6.64° with 13.30Å interplanar spacing. The size of the particle as determined using Debbye Scherre’s formula comes out around 15.5 nm. The presence of α phase of CuPc was confirmed using FTIR with the appearance of crystal parameter marker band at 787 cm-1. Apart from this A2u and Eu symmetry bands of CuPc have also been observed. The UV absorption spectrum of CuPc exhibits absorption peaks owing to π→ π* and n→ π* transitions. A blue shift in the prepared CuPc glass has been observed as compared to the dopant CuPc salt indicating increase of band gap. A split in B (Soret) band and Q band appears as observed with the help of Lorentzian fitting. CuPc sol gel glass has been exposed with chemical vapors of Methanol, Benzene and Bromine individually and the electrical measurements have been carried out. These measurements show the variation in conductivity and the interaction mechanism has been analyzed.

  18. Electrospinning of porphyrin/polyvinyl alcohol (PVA) nanofibers and their acid vapor sensing capability.

    Science.gov (United States)

    Jang, Kihun; Baek, Il Woong; Back, Sung Yul; Ahn, Heejoon

    2011-07-01

    Fluorescing 5,10,15,20-terakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate) (TMPyP)-embedded and -coated polyvinyl alcohol (PVA) nanofibers were fabricated by using the electrospinning technique. To improve nonpolar solvent solubility of TMPyP/PVA nanofibers, tetraethyl orthosilicate (TEOS) was used as a cross-linking agent. UV-vis spectroscopy showed a strong Q band and two relatively weak Soret bands from the TMPyP/PVA nanofibers, and revealed that the TMPyP molecules were homogeneously loaded to the fibers. Scanning electron microscopy revealed that the electrospun nanofibers had ultrafine structures with an average diameter of ca. 250 nm. X-ray photoelectron spectroscopy confirmed the compositional structure of TMPyP/PVA/TEOS nanofibers and revealed the relative coverage of TMPyP molecules on the surface of TMPyP-embedded and TMPyP-coated PVA/TEOS fibers. For the comparison of the acid vapor sensitivity, TMPyP-embedded PVA/TEOS films, and TMPyP-embedded PVA/TEOS fibers, TMPyP-coated PVA/TEOS fibers were exposed to 1N nitric-acid vapor for 20-60 seconds. Fluorescence microscopy revealed that TMPyP-coated PVA/TEOS nanofibers exhibited better acid-sensing capability than TMPyP-embedded PVA/TEOS nanofibers and films.

  19. A micro-system based on glass-nanoporous silicon for optical sensing of organic solvent vapor.

    Science.gov (United States)

    Kim, Young-You; Kim, Han-Jung; Kim, Ho-Jong; Choi, Dae-Geun; Cheng, Horchhong

    2012-06-01

    We present a recent experimental study on the application of nanoporous silicon (np-Si) to an optical vapor sensor. We fabricated the micro-system based on a glass-nanoporous silicon layer on a p(+)-type silicon wafer. To check the selectivity and sensitivity of the np-Si layer to organic vapors, we prepared three types of np-Si layer samples--a single layer, distributed Bragg reflector (DBR) layer, and microcavity layer--and investigated its reflectance spectra upon exposure to different concentrations of various organic vapors. When the np-Si layer samples were exposed to the organic vapors, a red-shift occurred in the reflectance spectrum, and we determined that this red-shift can be attributed to the changes in the refractive index induced by the capillary condensation of the organic vapor within the pores of the np-Si layer. The np-Si layer samples showed excellent sensing ability to different types and concentrations of organic vapors. After removing the organic vapors, the reflectance spectrum immediately returned to its original state.

  20. Two-way shift of wavelength in holographic sensing of organic vapor in nanozeolites dispersed acrylamide photopolymer.

    Science.gov (United States)

    Mao, Dongyao; Geng, Yaohui; Liu, Hongpeng; Zhou, Ke; Xian, Lihong; Yu, Dan

    2016-08-10

    Holographic sensing of alcohol organic vapor is characterized in detail at transmission and reflection geometries in Y nanozeolites dispersed acrylamide photopolymer. The two-way shift of the diffraction spectrum and its temporal evolution with various vapor concentrations are measured. Obvious blueshifts of diffraction spectrum peaks are observed and analyzed in two recording geometries. The competition mechanism between decreasing the average refractive index and swelling the grating fringe space is proposed for exploring the wavelength shift mechanism. In the reflection grating, as organic vapor increases, the redshift after the blueshift of the wavelength peaks are observed clearly. We further demonstrate the significance of this competition mechanism. In the low concentration region, at transmission blueshift of the wavelength is a significant factor in identifying an organic vapor with a low refractive index. These experimental results provide a probability for improving the applicability of a holographic sensor. This work can accelerate the development of the holographic sensing strategy and provide a novel identification method for organic vapor.

  1. Dynamics of chemical vapor sensing with MoS2 using 1T/2H phase contacts/channel

    Science.gov (United States)

    Friedman, Adam L.; Perkins, F. Keith; Hanbicki, Aubrey T.; Culbertson, James C.; Campbell, Paul M.

    2016-06-01

    Ultra-thin transition metal dichalcogenides (TMDs) films show remarkable potential for use in chemical vapor sensing devices. Electronic devices fabricated from TMD films are inexpensive, inherently flexible, low-power, amenable to industrial-scale processing because of emergent growth techniques, and have shown high sensitivity and selectivity to electron donor analyte molecules important for explosives and nerve gas detection. However, for devices reported to date, the conductance response to chemical vapors is dominated by Schottky contacts, to the detriment of the sensitivity, selectivity, recovery, and obscuring their intrinsic behavior. Here, we use contact engineering to transition the contacts in a MoS2 FET-based chemical vapor sensor to the 1T conducting phase, while leaving the channel in the 2H semiconducting state, and thus providing Ohmic contacts to the film. We demonstrate that the resultant sensors have much improved electrical characteristics, are more selective, and recover fully after chemical vapor exposure--all major enhancements to previously MoS2 sensor devices. We identify labile nitrogen-containing electron donors as the primary species that generate a response in MoS2, and we study the dynamics of the sensing reactions, identifying two possible qualitative models for the chemical sensing reaction.

  2. Rubrene endoperoxide acetone monosolvate

    Directory of Open Access Journals (Sweden)

    Kiyoaki Shinashi

    2012-04-01

    Full Text Available The title acetone solvate, C42H28O2·C3H6O [systematic name: 1,3,10,12-tetraphenyl-19,20-dioxapentacyclo[10.6.2.02,11.04,9.013,18]icosa-2(11,3,5,7,9,13,15,17-octaene acetone monosolvate], is a photooxygenation product of rubrene (systematic name: 5,6,11,12-tetraphenyltetracene. The molecule bends at the bridgehead atoms, which are linked by the O—O transannular bond, with a dihedral angle of 49.21 (6° between the benzene ring and the naphthalene ring system of the tetracene unit. In the crystal, the rubrene molecules are linked by C—H...O hydrogen bonds into a column along the c axis. The acetone solvent molecules form a dimer around a crystallographic inversion centre through a carbonyl–carbonyl dipolar interaction. A C—H...O hydrogen bond between the rubrene and acetone molecules is also observed.

  3. Synthesis of Ag-Au bimetallic film at liquid-liquid interface and its application in vapor sensing

    Energy Technology Data Exchange (ETDEWEB)

    Pasricha, Renu, E-mail: pasrichar@mail.nplindia.ernet.i [Material Characterization Division, National Physical Laboratory, New Delhi-110012 (India); Gupta, Shweta [Material Characterization Division, National Physical Laboratory, New Delhi-110012 (India); Sastry, M. [Tata Chemical Innovation Center, Anmol Pride, Baner Road, Pune-45 (India); Singh, Nahar; Gupta, Prabhat [Material Characterization Division, National Physical Laboratory, New Delhi-110012 (India)

    2010-11-30

    We demonstrate a novel process for preparing densely packed film of silver nanoparticles at the liquid-liquid interface followed by a transmetallation reaction with gold ion to yield a film of bimetallic nanoparticles. Films of assembled silver as well as Ag-Au bimetallic were characterized by UV-vis-spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analysis. I-V measurement shows linear behavior for both the films with ca. five orders of magnitude drop in resistance for the Ag-Au bimetallic film. Temperature dependent I-V measurement revealed a semiconductor to metal transition after transmetallation reaction. The films where checked for their potential application in chemical vapor sensing to ammonia vapors.

  4. Selective acetone gas sensors using porous WO{sub 3}-Cr{sub 2}O{sub 3} thin films prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Gao Peng; Ji Huiming, E-mail: jihuiming@tju.edu.cn; Zhou Yugui; Li Xiaolei

    2012-01-31

    WO{sub 3}-Cr{sub 2}O{sub 3} semiconducting thin films were prepared by sol-gel method. Acetone gas sensing properties were investigated. Monoclinic phase was obtained as determined by X-ray diffraction after WO{sub 3}-Cr{sub 2}O{sub 3} films were sintered in oxygen atmosphere for 1 h at 500 Degree-Sign C (quenched after sintering). Porous structure was observed by using field emission scanning electron microscopy. Electrical properties were studied by conductivity measurement. The acetone vapor sensing properties of these thin films were found strongly influenced by the porous structure, the content of Cr{sub 2}O{sub 3}, the sintering temperature, and the cooling way. As-prepared WO{sub 3}-Cr{sub 2}O{sub 3} thin films exhibit excellent acetone vapor sensing properties with the maximum sensitivity {approx} 8.91 at 320 Degree-Sign C in air atmosphere with fast response and recovery time. - Highlights: Black-Right-Pointing-Pointer Porous structure was prepared to improve the thin film's gas-sensing properties. Black-Right-Pointing-Pointer Dissymmetrical monoclinic structure was obtained to improve selectivity to acetone. Black-Right-Pointing-Pointer Quenching after sintering enables obtain dissymmetrical structure. Black-Right-Pointing-Pointer Effects of the sintering temperature and the Cr{sub 2}O{sub 3} content were discussed. Black-Right-Pointing-Pointer As prepared sensors can diagnose diabetes based on human breath analysis.

  5. Physico-chemical mechanism for the vapors sensitivity of photoluminescent InP quantum dots

    Science.gov (United States)

    Prosposito, P.; De Angelis, R.; De Matteis, F.; Hatami, F.; Masselink, W. T.; Zhang, H.; Casalboni, M.

    2016-03-01

    InP/InGaP surface quantum dots are interesting materials for optical chemical sensors since they present an intense emission at room temperature, whose intensity changes rapidly and reversibly depending on the composition of the environmental atmosphere. We present here their emission properties by time resolved photoluminescence spectroscopy investigation and we discuss the physico-chemical mechanism behind their sensitivity to the surrounding atmosphere. Photoluminescence transients in inert atmosphere (N2) and in solvent vapours of methanol, clorophorm, acetone and water were measured. The presence of vapors of clorophorm, acetone and water showed a very weak effect on the transient times, while an increase of up to 15% of the decay time was observed for methanol vapour exposure. On the basis of the vapor molecule nature (polarity, proticity, steric hindrance, etc.) and of the interaction of the vapor molecules with the quantum dots surface a sensing mechanism involving quantum dots non-radiative surface states is proposed.

  6. Graphene/Silicon heterojunction Schottky diode for vapors sensing using impedance spectroscopy.

    Science.gov (United States)

    Fattah, Ali; Khatami, Saeid; Mayorga-Martinez, Carmen C; Medina-Sánchez, Mariana; Baptista-Pires, Luis; Merkoçi, Arben

    2014-10-29

    A graphene(G)/Silicon(Si) heterojunction Schottky diode and a simple method that evaluates its electrical response to different chemical vapors using electrochemical impedance spectroscopy (EIS) are implemented. To study the impedance response of the device of a given vapor, relative impedance change (RIC) as a function of the frequency is evaluated. The minimum value of RIC for different vapors corresponds to different frequency values (18.7, 12.9 and 10.7 KHz for chloroform, phenol, and methanol vapors respectively). The impedance responses to phenol, beside other gases used as model analytes for different vapor concentrations are studied. The equivalent circuit of the device is obtained and simplified, using data fitting from the extracted values of resistances and capacitances. The resistance corresponding to interphase G/Si is used as a parameter to compare the performance of this device upon different phenol concentrations and a high reproducibility with a 4.4% relative standard deviation is obtained. The efficiency of the device fabrication, its selectivity, reproducibility and easy measurement mode using EIS makes the developed system an interesting alternative for gases detection for environmental monitoring and other industrial applications.

  7. ZnO–PDMS Nanohybrids: A Novel Optical Sensing Platform for Ethanol Vapor Detection at Room Temperature

    KAUST Repository

    Klini, Argyro

    2015-01-08

    © 2014 American Chemical Society. A new optical gas sensor platform based on highly luminescent ZnO-polymer nanohybrids is demonstrated. The nanohybrids consist of ZnO nanoparticles, typically 125 (±25) nm in size, dispersed in an inert cross-linked polydimethylsiloxane (PDMS) matrix. Upon exposure to ethanol-enriched air at room temperature, the nanocomposites exhibit a clear increase in their photoluminescence (PL) emission, which shows a nearly Langmuir dependence on the alcohol vapor pressure. The response time is on the order of 50 s, particularly at low ethanol concentrations. The limit of ethanol vapor detection (LOD) is as low as 0.4 Torr, while the sensor remains unaffected by the presence of water vapor, demonstrating the potential of the ZnO-PDMS system as an optical gas sensing device. The interaction of the ZnO nanoparticles with molecular oxygen plays an essential role on the overall performance of the sensor, as shown in comparative experiments performed in the presence and absence of atmospheric air. Notably, O2 was found to be quite effective in accelerating the sensor recovery process compared to N2 or vacuum.

  8. Vapor sensing by means of a ZnO-on-Si surface acoustic wave resonator

    Science.gov (United States)

    Martin, S. J.; Schweizer, K. S.; Schwartz, S. S.; Gunshor, R. L.

    Surface Acoustic Wave (SAW) devices can function as sensitive detectors of vapors. The high surface acoustic energy density of the device makes it extremely sensitive to the presence of molecules adsorbed from the gas phase. Mass loading by the adsorbate is the primary mechanism for the surface wave velocity perturbation. If the device is used as the frequency control element of an oscillator, perturbations in wave velocity on the order of 10 parts per billion may be resolved by means of a frequency counter. Zno-on-Si SAW resonators have been examined as vapor sensors. The piezoelectric ZnO layer permits transduction between electrical and acoustic energies, as well as endowing the surface with particular adsorptive properties. These devices exhibit C-values up to 12,000 at a resonant frequency of 109 MHZ. The resonant frequency of the device shifts upon exposure to a vapor-air mixture, with a transient response which is distinct for each of the organic vapors tested. Due to the permeability of the polycrystalline ZnO layer, the instantaneous reversibility of the resonant frequency shift is found to depend on the type of adsorbed molecule.

  9. Acetone:isomedzation and aggregation

    Institute of Scientific and Technical Information of China (English)

    HU Zhan; JIN Ming-xing; XU Xue-song; CHENG Xi-hui; DING Da-jun

    2006-01-01

    The advanced experimental and theoretical techniques enable us to obtain information on the rearrangement of atoms or molecules in a reaction nowadays.As an example,we report on our research work on acetone isomerization and aggregation to give an insight into the reaction pathways,the products and their structures,and the growth regularity of aggregation.The evidences on the structural change of acetone and the stability of acetone clusters are found by a laser ionization mass spectrometer and the results are interpreted from theoretical analysis based on the DFT/B3LYP method.Various isomerization channels of acetone have been established and the optimal structures of the neutral clusters (CH3COCH3)n and the protonated acetone clusters (CH3COCHa)n H+ for n=1-7 have been determined.

  10. Discourse on the utilization of polyaniline coatings for surface plasmon resonance sensing of ammonia vapor.

    Science.gov (United States)

    Menegazzo, Nicola; Herbert, Bryon; Banerji, Soame; Booksh, Karl S

    2011-09-15

    Surface plasmon resonance spectroscopy is sensitive to near-surface (gas-phase sensing with SPR include conducting metal oxides, polymers and organometallic dyes. Electrically conducting polymers, like polyaniline and polypyrrole, display dramatic conductivity changes in the presence of certain compounds. This property has resulted in their routine incorporation into different sensing schemes. However, application of electrically conducting polymers to SPR gas-phase sensing has been limited to a few examples, despite encouraging results. The emeraldine salt form of polyaniline (PAni) demonstrates a decreased electrical conductivity correlated to NH(3) concentration. In this contribution, PAni doped with camphorsulfonic acid (PAni-CSA) was applied to gas-phase sensing of NH(3) by way of SPR spectroscopy. Spectroscopic ellipsometry was used to determine the optical constants (n and k) for emeraldine salt and emeraldine base forms of PAni, confirming the wavelength-dependent response observed via SPR. The analytical performance of the coatings show that a limit of detection of 32 ppm NH(3) based on precision of the mass-flow controllers used and an estimated method limit of detection of ∼0.2 ppm based on three standard deviations of the blank. This is directly comparable to other, more established sensing architectures.

  11. Catalyst-Free Vapor-Phase Method for Direct Integration of Gas Sensing Nanostructures with Polymeric Transducing Platforms

    Directory of Open Access Journals (Sweden)

    Stella Vallejos

    2014-01-01

    Full Text Available Tungsten oxide nanoneedles (NNs are grown and integrated directly with polymeric transducing platforms for gas sensors via aerosol-assisted chemical vapor deposition (AACVD method. Material analysis shows the feasibility to grow highly crystalline nanomaterials in the form of NNs with aspect ratios between 80 and 200 and with high concentration of oxygen vacancies at the surface, whereas gas testing demonstrates moderate sensing responses to hydrogen at concentrations between 10 ppm and 50 ppm, which are comparable with results for tungsten oxide NNs grown on silicon transducing platforms. This method is demonstrated to be an attractive route to fabricate next generation of gas sensors devices, provided with flexibility and functionality, with great potential in a cost effective production for large-scale applications.

  12. Sorption and Diffusion of Water Vapor and Carbon Dioxide in Sulfonated Polyaniline as Chemical Sensing Materials

    Directory of Open Access Journals (Sweden)

    Qiuhua Liang

    2016-04-01

    Full Text Available A hybrid quantum mechanics (QM/molecular dynamics (MD simulation is performed to investigate the effect of an ionizable group (–SO3−Na+ on polyaniline as gas sensing materials. Polymers considered for this work include emeraldine base of polyaniline (EB-PANI and its derivatives (Na-SPANI (I, (II and (III whose rings are partly monosubstituted by –SO3−Na+. The hybrid simulation results show that the adsorption energy, Mulliken charge and band gap of analytes (CO2 and H2O in polyaniline are relatively sensitive to the position and the amounts of –SO3−Na+, and these parameters would affect the sensitivity of Na-SPANI/EB-PANI towards CO2. The sensitivity of Na-SPANI (III/EB-PANI towards CO2 can be greatly improved by two orders of magnitude, which is in agreement with the experimental study. In addition, we also demonstrate that introducing –SO3−Na+ groups at the rings can notably affect the gas transport properties of polyaniline. Comparative studies indicate that the effect of ionizable group on polyaniline as gas sensing materials for the polar gas molecule (H2O is more significant than that for the nonpolar gas molecule (CO2. These findings contribute in the functionalization-induced variations of the material properties of polyaniline for CO2 sensing and the design of new polyaniline with desired sensing properties.

  13. Strong Fluorescent Smart Organogel as a Dual Sensing Material for Volatile Acid and Organic Amine Vapors.

    Science.gov (United States)

    Xue, Pengchong; Yao, Boqi; Wang, Panpan; Gong, Peng; Zhang, Zhenqi; Lu, Ran

    2015-11-23

    An L-phenylalanine derivative (C12PhBPCP) consisting of a strong emission fluorophore with benzoxazole and cyano groups is designed and synthesized to realize dual responses to volatile acid and organic amine vapors. The photophysical properties and self-assembly of the said derivative in the gel phase are also studied. C12PhBPCP can gelate organic solvents and self-assemble into 1 D nanofibers in the gels. UV/Vis absorption spectral results show H-aggregate formation during gelation, which indicates strong exciton coupling between fluorophores. Both wet gel and xerogel emit strong green fluorescence because the cyano group suppresses fluorescence quenching in the self-assemblies. Moreover, the xerogel film with strong green fluorescence can be used as a dual chemosensor for quantitative detection of volatile acid and organic amine vapors with fast response times and low detection limits owing to its large surface area and amplified fluorescence quenching. The detection limits are 796 ppt and 25 ppb for gaseous aniline and trifluoroacetic acid (TFA), respectively.

  14. Optimizing detection of RDX vapors using designed experiments for remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Robert G.; Heredia-Langner, Alejandro; Warner, Marvin G.

    2014-03-24

    Abstract: This paper presents results of experiments performed to study the effect of four factors on the detection of RDX vapors from desorption into an atmospheric flow tube mass spectrometer (AFT-MS). The experiments initially included four independent factors: gas flow rate, desorption current, solvent evaporation time and RDX mass. The values of three detection responses, peak height, peak width, and peak area were recorded but only the peak height response was analyzed. Results from the first block of experiments indicated that solvent evaporation time was not statistically significant. A second round of experiments was performed using flow rate, current, and RDX mass as factors and the results were used to create a model to predict conditions resulting in maximum peak height. Those conditions were confirmed experimentally and used to obtain data for a calibration model. The calibration model represented RDX amounts ranging from 1 to 25 pg desorbed into an air flow of 7 L/min. Air samples from a shipping container that held 2 closed explosive storage magazines were collected on metal filaments for varying amounts for time ranging from 5 to 90 minutes. RDX was detected from all of the filaments sampled by desorption into the AFT-MS. From the calibration model, RDX vapor concentrations within the shipping container were calculated to be in the range of 1 to 50 parts-per-quadrillion from data collected on 2 separate days.

  15. STW resonator with organo-functionalized metallic nanoparticle film for vapor sensing.

    Science.gov (United States)

    Strashilov, Vesseline L; Alexieva, Gergana E; Velichkov, Velitchko N; Avramov, Ivan D; Evans, Stephen D

    2009-05-01

    A 1 GHz surface transverse wave resonator on 36 degrees Y-cut quartz plate coated with organothiol-functionalized gold nanoparticle film has been studied as a chemical gas sensor. Considerable sensitivity of the resonant frequency to vapors of ethanol, methanol, chloroform, and acetic acid has been found. Owing to the high short-term stability of the oscillator built, the detection limit is in the low ppm range. The results qualitatively confirm previous results on the same film type obtained by conductivity measurements. In the present case, the conductivity effect resulting from variable separation of nanoparticles is accompanied with surface-attached mass of the absorbed gas. The film matrix exhibits considerable capacity to absorb large amounts of molecules at high gas concentrations.

  16. Fabrication of a SnO2-Based Acetone Gas Sensor Enhanced by Molecular Imprinting

    Directory of Open Access Journals (Sweden)

    Wenhu Tan

    2014-12-01

    Full Text Available This work presents a new route to design a highly sensitive SnO2–based sensor for acetone gas enhanced by the molecular imprinting technique. Unassisted and acetone-assisted thermal synthesis methods are used to synthesis SnO2 nanomaterials. The prepared SnO2 nanomaterials have been characterized by X-ray powder diffraction, scanning electron microscopy and N2 adsorption−desorption. Four types of SnO2 films were obtained by mixing pure deionized water and liquid acetone with the two types of as-prepared powders, respectively. The acetone gas sensing properties of sensors coated by these films were evaluated. Testing results reveal that the sensor coated by the film fabricated by mixing liquid acetone with the SnO2 nanomaterial synthesized by the acetone-assisted thermal method exhibits the best acetone gas sensing performance. The sensor is optimized for the smooth adsorption and desorption of acetone gas thanks to the participation of acetone both in the procedure of synthesis of the SnO2 nanomaterial and the device fabrication, which results in a distinct response–recovery behavior.

  17. Green synthesis of CdFe2O4 nanoparticles and their application for vapor sensing

    Directory of Open Access Journals (Sweden)

    Sachin Bangale

    2013-03-01

    Full Text Available The work reported about preparation of nanocrystalline CdFe2O4 through an combustion method and characterization of their microstructural, morphological and gas sensing properties. The structural properties investigated by X-ray diffraction revealed with CdFe2O4 cubic structure. crystallite size was found to be ~ 64 nm. The morphological study characterized by scanning electron microscopy and transmission electron microscopy. The sensor fabricated from these nanocrystalline CdFe2O4 exhibits high sensitivity and rapid response/recovery to ethanol at 350 °C. The sensitivity was up to 59.23% when the sensor was exposed to 50 to 200 ppm ethanol and the response and recovery time is about 40 and 50 s respectively. The linear dependence of sensitivity on the ethanol concentration was found in the range 50-200 ppm. Hence studies revealled that nanocrystalline CdFe2O4 can be used as sensing material for fabricating high performance ethanol sensors.

  18. The microwave opacity of ammonia and water vapor: Application to remote sensing of the atmosphere of Jupiter

    Science.gov (United States)

    Hanley, Thomas Ryan

    2008-06-01

    The object of this research program has been to provide a baseline for microwave remote sensing of ammonia and water vapor in the atmosphere of Jupiter through laboratory measurements of their microwave absorption properties. Jupiter is not only the largest planet in our solar system, but one of the most interesting and complex. Despite a handful of spacecraft missions and many astronomical measurements, much of Jupiter's atmospheric dynamics and composition remain a mystery. Although constraints have been formed on the amount of certain gases present, the global abundances and distributions of water vapor (H 2 O) and ammonia (NH 3 ) are relatively unknown. Measurements of H 2 O and NH 3 in the Jovian atmosphere to hundreds of bars of pressure are best accomplished via passive microwave emission measurements. For these measurements to be accurately interpreted, however, the hydrogen and helium pressure-broadened microwave opacities of H 2 O and NH 3 must be well characterized, a task that is very difficult if based solely on theory and limited laboratory measurements. Therefore, accurate laboratory measurements have been taken under a broad range of conditions that mimic those of the Jovian atmosphere. These measurements, performed using a newly redesigned high- accuracy system, and the corresponding models of microwave opacity that have been developed from them comprise the majority of this work. The models allow more accurate retrievals of H 2 O and NH 3 abundances from previous as well as future missions to Jupiter and the outer planets, such as the NASA New Frontiers class Juno mission scheduled for launch in 2011. This information will enable a greater understanding of the concentration and distribution of H 2 O and NH 3 in the Jovian atmosphere, which will reveal much about how Jupiter and our solar system formed and how similar planets could form in other solar systems, even planets that may be hospitable to life.

  19. Unencapsulated Air-stable Organic Field Effect Transistor by All Solution Processes for Low Power Vapor Sensing

    Science.gov (United States)

    Feng, Linrun; Tang, Wei; Zhao, Jiaqing; Yang, Ruozhang; Hu, Wei; Li, Qiaofeng; Wang, Ruolin; Guo, Xiaojun

    2016-02-01

    With its excellent mechanical flexibility, low-cost and low-temperature processing, the solution processed organic field-effect transistor (OFET) is a promising platform technology for developing ubiquitous sensor applications in digital health, environment monitoring and Internet of Things. However, a contradiction between achieving low voltage operation and having stable performance severely hinder the technology to become commercially viable. This work shows that, by reducing the sub-gap density of states (DOS) at the channel for low operation voltage and using a proper low-k non-polar polymer dielectric layer, such an issue can be addressed. Stable electrical properties after either being placed for weeks or continuously prolonged bias stressing for hours in ambient air are achieved for all solution processed unencapsulated OFETs with the channel being exposed to the ambient air for analyte detection. The fabricated device presents a steep subthreshold swing less than 100 mV/decade, and an ON/OFF ratio of 106 at a voltage swing of 3 V. The low voltage and stable operation allows the sensor made of the OFET to be incorporated into a battery-powered electronic system for continuously reliable sensing of ammonia vapor in ambient air with very small power consumption of about 50 nW.

  20. Quantification of acetone emission from pine plants

    Institute of Scientific and Technical Information of China (English)

    SHAO; Min; (邵敏); Jürgen; Wildt

    2002-01-01

    Acetone emission from pine plants (pinus sylvestris) is measured by continuously stirred tank reactor. Under a constant light intensity, acetone emission rates increase exponentially with leaf temperature. When leaf temperature is kept constant, acetone emission increases with light intensity. And acetone emission in darkness is also detected. Acetone emitted from pine is quickly labeled by 13C when the plants are exposed to air with 630 mg/m3 13CO2. However, no more than 20% of acetone is 13C labeled. Acetone emission from pine may be due to both leaf temperature- controlled process and light intensity-controlled process. Based on these understandings, an algorithm is used to describe the short term acetone emission rates from pine.

  1. A Remote Sensing Method for Estimating Surface Air Temperature and Surface Vapor Pressure on a Regional Scale

    Directory of Open Access Journals (Sweden)

    Renhua Zhang

    2015-05-01

    Full Text Available This paper presents a method of estimating regional distributions of surface air temperature (Ta and surface vapor pressure (ea, which uses remotely-sensed data and meteorological data as its inputs. The method takes into account the effects of both local driving force and horizontal advection on Ta and ea. Good correlation coefficients (R2 and root mean square error (RMSE between the measurements of Ta/ea at weather stations and Ta/ea estimates were obtained; with R2 of 0.77, 0.82 and 0.80 and RMSE of 0.42K, 0.35K and 0.20K for Ta and with R2 of 0.85, 0.88, 0.88 and RMSE of 0.24hpa, 0.35hpa and 0.16hpa for ea, respectively, for the three-day results. This result is much better than that estimated from the inverse distance weighted method (IDW. The performance of Ta/ea estimates at Dongping Lake illustrated that the method proposed in the paper also has good accuracy for a heterogeneous surface. The absolute biases of Ta and ea estimates at Dongping Lake from the proposed method are less than 0.5Kand 0.7hpa, respectively, while the absolute biases of them from the IDW method are more than 2K and 3hpa, respectively. Sensitivity analysis suggests that the Ta estimation method presented in the paper is most sensitive to surface temperature and that the ea estimation method is most sensitive to available energy.

  2. Multivariable passive RFID vapor sensors: roll-to-roll fabrication on a flexible substrate.

    Science.gov (United States)

    Potyrailo, Radislav A; Burns, Andrew; Surman, Cheryl; Lee, D J; McGinniss, Edward

    2012-06-21

    We demonstrate roll-to-roll (R2R) fabrication of highly selective, battery-free radio frequency identification (RFID) sensors on a flexible polyethylene terephthalate (PET) polymeric substrate. Selectivity of our developed RFID sensors is provided by measurements of their resonance impedance spectra, followed by the multivariate analysis of spectral features, and correlation of these spectral features to the concentrations of vapors of interest. The multivariate analysis of spectral features also provides the ability for the rejection of ambient interferences. As a demonstration of our R2R fabrication process, we employed polyetherurethane (PEUT) as a "classic" sensing material, extruded this sensing material as 25, 75, and 125-μm thick films, and thermally laminated the films onto RFID inlays, rapidly producing approximately 5000 vapor sensors. We further tested these RFID vapor sensors for their response selectivity toward several model vapors such as toluene, acetone, and ethanol as well as water vapor as an abundant interferent. Our RFID sensing concept features 16-bit resolution provided by the sensor reader, granting a highly desired independence from costly proprietary RFID memory chips with a low-resolution analog input. Future steps are being planned for field-testing of these sensors in numerous conditions.

  3. (RS-Efonidipine acetone hemisolvate

    Directory of Open Access Journals (Sweden)

    Yu-Heng Liu

    2016-09-01

    Full Text Available The asymmetric unit of the title compound, C34H38N3O7P·0.5C3H6O {systematic name: (RS-2-[phenyl(phenylmethylamino]ethyl 5-(5,5-dimethyl-2-oxo-1,3-dioxa-2λ5-phosphacyclohex-2-yl-2,6-dimethyl-4-(3-nitrophenyl-1,4-dihydropyridine-3-carboxylate acetone hemisolvate}, contains one R-efonidipine molecule, one S-efonidipine molecule and half of a solvate acetone molecule. In both efonidipine molecules, the six-membered rings of the dioxaphosphinanyl moieties display a chair conformation and the dihydropyridine rings display a flattened boat conformation. In the crystal, N—H...O, C—H...O hydrogen bonds and weak C—H...π interactions link the molecules into a three-dimensional supramolecular structure. A solvent-accessible void of 199 Å3 is found in the structure; the contribution of the heavily disordered solvate molecule was suppressed by use of the SQUEEZE routine in PLATON [Spek (2015. Acta Cryst. C71, 9–18].

  4. Conditioned Place Preference to Acetone Inhalation and the Effects on Locomotor Behavior and 18FDG Uptake

    Energy Technology Data Exchange (ETDEWEB)

    Pai, J.C.; Dewey, S.L.; Schiffer, W.; Lee, D.

    2006-01-01

    Acetone is a component in many inhalants that have been widely abused. While other solvents have addictive potential, such as toluene, it is unclear whether acetone alone contains addictive properties. The locomotor, relative glucose metabolism and abusive effects of acetone inhalation were studied in animals using the conditioned place preference (CPP) paradigm and [18F]2-fluorodeoxy-D-glucose (18FDG) imaging. The CPP apparatus contains two distinct conditioning chambers and a middle adaptation chamber, each lined with photocells to monitor locomotor activity. Adolescent Sprague-Dawley rats (n=16; 90-110 g) were paired with acetone in least preferred conditioning chamber, determined on the pretest day. The animals were exposed to a 10,000 ppm dose for an hour, alternating days with air. A CPP test was conducted after the 3rd, 6th and 12th pairing. In these same animals, the relative glucose metabolism effects were determined using positron emission tomography (PET) imaging with 18FDG. Following the 3rd pairing, there was a significant aversion to the acetone paired chamber (190.9 ± 13.7 sec and 241.7 ± 16.9 sec, acetone and air, respectively). After the 6th pairing, there was no significant preference observed with equal time spent in each chamber (222 ± 21 sec and 207 ± 20 sec, acetone and air-paired, respectively). A similar trend was observed after the 12th pairing (213 ± 21 sec and 221 ± 22 sec, acetone and air-paired, respectively). Locomotor analysis indicated a significant decrease (p<0.05) from air pairings to acetone pairings on the first and sixth pairings. The observed locomotor activity was characteristic of central nervous system (CNS) depressants, without showing clear abusive effects in this CPP model. In these studies, acetone vapors were not as reinforcing as other solvents, shown by overall lack of preference for the acetone paired side of the chamber. PET imaging indicated a regionally specific distribution of 18FDG uptake following

  5. An Acetone Microsensor with a Ring Oscillator Circuit Fabricated Using the Commercial 0.18 μm CMOS Process

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Yang

    2014-07-01

    Full Text Available This study investigates the fabrication and characterization of an acetone microsensor with a ring oscillator circuit using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS process. The acetone microsensor contains a sensitive material, interdigitated electrodes and a polysilicon heater. The sensitive material is α-Fe2O3 synthesized by the hydrothermal method. The sensor requires a post-process to remove the sacrificial oxide layer between the interdigitated electrodes and to coat the α-Fe2O3 on the electrodes. When the sensitive material adsorbs acetone vapor, the sensor produces a change in capacitance. The ring oscillator circuit converts the capacitance of the sensor into the oscillation frequency output. The experimental results show that the output frequency of the acetone sensor changes from 128 to 100 MHz as the acetone concentration increases 1 to 70 ppm.

  6. Applied light-side coupling with optimized spiral-patterned zinc oxide nanorod coatings for multiple optical channel alcohol vapor sensing

    Science.gov (United States)

    Bin Abdul Rahim, Hazli Rafis; Bin Lokman, Muhammad Quisar; Harun, Sulaiman Wadi; Hornyak, Gabor Louis; Sterckx, Karel; Mohammed, Waleed Soliman; Dutta, Joydeep

    2016-07-01

    The width of spiral-patterned zinc oxide (ZnO) nanorod coatings on plastic optical fiber (POF) was optimized theoretically for light-side coupling and found to be 5 mm. Structured ZnO nanorods were grown on large core POFs for the purpose of alcohol vapor sensing. The aim of the spiral patterns was to enhance signal transmission by reduction of the effective ZnO growth area, thereby minimizing light leakage due to backscattering. The sensing mechanism utilized changes in the output signal due to adsorption of methanol, ethanol, and isopropanol vapors. Three spectral bands consisting of red (620 to 750 nm), green (495 to 570 nm), and blue (450 to 495 nm) were applied in measurements. The range of relative intensity modulation (RIM) was determined to be for concentrations between 25 to 300 ppm. Methanol presented the strongest response compared to ethanol and isopropanol in all three spectral channels. With regard to alcohol detection RIM by spectral band, the green channel demonstrated the highest RIM values followed by the blue and red channels, respectively.

  7. Investigation of efficiency of air cleaning from acetone using a segmental construction biofilter

    Directory of Open Access Journals (Sweden)

    Denas Bacevičius

    2015-10-01

    Full Text Available Volatile organic compounds, e. g. acetone, have a direct impact on climate change, decrease of ozone in the air, and on the growth of greenhouse effect. One of the most popular air purifying methods from VOC is a biological air cleaning. Experimental investigations were conducted to determine the efficiency of the new structure of biofilter with polypropylene plates segments. During the investigations the efficiency of segmental construction biofilter of air purification at different initial concentrations of pollutants was determined. Different concentrations of pollutants were estimated during the acetone dilution with water. During the tests the efficiency of biofilter air purification from acetone vapor and its change under different concentrations of vapors was set. Based on test results, the maximum efficiency of biofilter air purification was up to 93%. Studies have shown that increasing the allowable pollutant concentration, the efficiency of air purification unit decreases. Increasing the concentration of supplied acetone vapor into the biofilter from 232 to 701 mg/m3, cleaning efficiency decreased from 92.8 to 82.3%. Since microorganisms fail to oxidize organic compounds, the filter works better at lower initial concentrations of pollutants.

  8. Self-assembly and sensing-group graft of pre-modified CNTs on resonant micro-cantilevers for specific detection of volatile organic compound vapors

    Science.gov (United States)

    Xu, Pengcheng; Li, Xinxin; Yu, Haitao; Liu, Min; Li, Jungang

    2010-11-01

    This paper reports MWCNT (multi-wall carbon nano-tube)-modified resonant micro-cantilever chemical sensors for detection of trinitrotoluene (TNT) vapor. The MWCNTs are pre-modified and then area-selectively self-assembled at the free-end gold pad of a micro-cantilever, in which a resonance-exciting heater and a signal-readout piezoresistive Wheatstone bridge are integrated. Featuring a high specific surface area, the MWCNTs are further functionalized with TNT-sensitive groups by grafting onto the sidewalls of the MWCNTs. To lower the non-specific absorption of water and other small organic molecules, the SiO2 surface of the micro-cantilever was also pre-treated for hydrophobicity and oleophobicity by self-assembling a monolayer of heptadecafluorodecyltrimethoxysilane. The results of our sensing experiments have shown a capability to rapidly detect ppb-level TNT vapor, and a high specificity of the functionalized groups to TNT molecules. The experiment has also confirmed a good long-term stability in detecting sensitivity.

  9. Composition measurement of bicomponent droplets using laser-induced fluorescence of acetone

    Science.gov (United States)

    Maqua, C.; Depredurand, V.; Castanet, G.; Wolff, M.; Lemoine, F.

    2007-12-01

    Commercial fuels are complex mixtures, the evaporation of which remains particularly difficult to model. Experimental characterization of the differential vaporization of the components is a problem that is seldom addressed. In this paper, the evaporation of binary droplets made of ethyl-alcohol and acetone is investigated using a technique of measurement of the droplet composition developed in purpose. This technique exploits the laser induced fluorescence of acetone which acts as a fluorescent tracer as well as the more volatile component of the fuel associated with an accurate measurement of the droplet diameter by forward scattering interferometry. A model of the fluorescence intensity of the binary mixture, taking into account the absorption of the acetone molecules, is proposed and validated. The sensitivity of the technique is discussed. Finally, the reliability of the technique is demonstrated on binary combusting droplets in linear stream.

  10. Breath acetone monitoring by portable Si:WO{sub 3} gas sensors

    Energy Technology Data Exchange (ETDEWEB)

    Righettoni, Marco; Tricoli, Antonio; Gass, Samuel [Particle Technology Laboratory, Department of Mechanical and Process Engineering ETH Zurich, CH-8092 Zurich (Switzerland); Schmid, Alex; Amann, Anton [Univ.-Clinic for Anesthesia, Innsbruck Medical University, A-6020 Innsbruck (Austria); Breath Research Institute of the Austrian Academy of Sciences, A-6850 Dornbirn (Austria); Pratsinis, Sotiris E., E-mail: sotiris.pratsinis@ptl.mavt.ethz.ch [Particle Technology Laboratory, Department of Mechanical and Process Engineering ETH Zurich, CH-8092 Zurich (Switzerland)

    2012-08-13

    Highlights: Black-Right-Pointing-Pointer Portable sensors were developed and tested for monitoring acetone in the human breath. Black-Right-Pointing-Pointer Acetone concentrations down to 20 ppb were measured with short response times (<30 s). Black-Right-Pointing-Pointer The present sensors were highly selective to acetone over ethanol and water. Black-Right-Pointing-Pointer Sensors were applied to human breath: good agreement with highly sensitive PTR-MS. Black-Right-Pointing-Pointer Tests with people at rest and during physical activity showed the sensor robustness. - Abstract: Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO{sub 3} nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone ({approx}20 ppb) with short response (10-15 s) and recovery times (35-70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80-90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques.

  11. Atmospheric heteroseneous reaction of acetone: Adsorption and desorption kinetics and mechanisms on SiO2 particles

    Institute of Scientific and Technical Information of China (English)

    JIE ChongYu; CHEN ZhongMing; WANG HongLi; HUA Wei; WANG CaiXia; LI Shuang

    2008-01-01

    Acetone plays an important role in photooxidation processes in the atmosphere. Up to date, little is known regarding the heterogeneous fate of acetone. In this study, the adsorption and desorption processes of acetone on SiO2 particles, which are the major constituent of mineral dust in the atmos-phere, have been investigated for the first time under the simulated atmospheric conditions, using in situ transmission Fourier transform infrared spectroscopy. It is found that acetone molecules are ad-sorbed on the surfaces of SiO2 particles by van der Waals forces and hydrogen bonding forces in a nonreactive and reversible state. The rates of initial adsorption and initial desorption, initial uptake coefficients and adsorption concentrations at equilibrium have been determined at different relative humidity. The presence of water vapor cannot result in the formation of new substances, but can de-crease the adsorption ability by consuming or overlapping the isolated OH groups on the surfaces of SiO2 particles. In the desorption process, a considerable amount of acetone molecules will remain on SiO2 particles in dry air, whereas acetone molecules are almost completely desorbed at a high relative humidity. In order to evaluate the role of heterogeneous reactions of acetone and other carbonyl compounds in the atmosphere, a new model fitting the atmospheric conditions is needed.

  12. Measuring breath acetone for monitoring fat loss: Review

    OpenAIRE

    Anderson, Joseph C.

    2015-01-01

    Objective Endogenous acetone production is a by‐product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in...

  13. Porphyrin nanoassemblies via surfactant-assisted assembly and single nanofiber nanoelectronic sensors for high-performance H₂O₂ vapor sensing.

    Science.gov (United States)

    Guo, Peipei; Zhao, Guangyao; Chen, Penglei; Lei, Bin; Jiang, Lang; Zhang, Hantang; Hu, Wenping; Liu, Minghua

    2014-04-22

    Porphyrins are recognized as important π-conjugated molecules correlating supramolecular chemistry, nanoscience, and advanced materials science. So far, as their supramolecular nanoassemblies are addressed, most efforts focus on the photo- or opto-related subjects. Beyond these traditional subjects, it is strongly desired to develop advanced porphyrin nanoassemblies in some other new topics of paramount importance. By means of a surfactant-assisted assembly, we herein show that porphyrins of different central metal ions, 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (H2TPyP), zinc 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (ZnTPyP), and oxo-[5,10,15,20-tetra(4-pyridyl)porphyrinato]titanium(IV) (TiOTPyP), could be organized to form irregular aggregates, short nanorods, and long yet straight nanofibers, respectively. Remarkably, in terms of an organic ribbon mask technique, we show that such long yet straight TiOTPyP nanofibers could be integrated into single nanofiber-based two-end nanoelectronics. Such simple nanodevices could serve as high-performance sensors of a satisfactory stability, reproducibility, and selectivity for an expeditious detection of vapor-phase H2O2. This provides a new alternative for a fast sensing of vapor-phase H2O2, which is currently an important issue in the fields of anti-terrorism, industrial healthcare, etc. In contrast to the traditional investigations focusing on the photo- or opto-related topics, our work endows porphyrin nanostructures with new opportunities as advanced nanomaterials in terms of portable yet high-performance nanoelectronic sensors, which is an issue of general concern in modern advanced nanomaterials.

  14. Microbial acetone oxidation in coastal seawater

    Directory of Open Access Journals (Sweden)

    Joanna Lee Dixon

    2014-05-01

    Full Text Available Acetone is an important oxygenated volatile organic compound in the troposphere where it influences the oxidising capacity of the atmosphere. However, the air-sea flux is not well quantified, in part due to a lack of knowledge regarding which processes control oceanic concentrations, and, specifically whether microbial oxidation to CO2 represents a significant loss process. We demonstrate that 14C labelled acetone can be used to determine microbial oxidation to 14CO2. Linear microbial rates of acetone oxidation to CO2 were observed for between 0.75-3.5 hours at a seasonally eutrophic coastal station located in the western English Channel (L4. A kinetic experiment in summer at station L4 gave a Vmax of 4.1 pmol L-1 h-1, with a Km constant of 54 pM. We then used this technique to obtain microbial acetone loss rates ranging between 1.2-42 pmol L-1 h-1 (monthly averages over an annual cycle at L4, with maximum rates observed during winter months. The biological turnover time of acetone (in situ concentration divided by microbial oxidation rate in surface waters varied from ~3 days in February 2011, when in situ concentrations were 3 ± 1 nM, to >240 days in June 2011, when concentrations were more than 2 fold higher at 7.5 ± 0.7 nM. These relatively low marine microbial acetone oxidation rates, when normalised to in situ concentrations, suggest that marine microbes preferentially utilise other oxygenated volatile organic compounds such as methanol and acetaldehyde.

  15. Dispensing fuel with aspiration of condensed vapors

    Energy Technology Data Exchange (ETDEWEB)

    Butkovich, M.S.; Strock, D.J.

    1993-08-10

    A vapor recovery process is described, comprising the steps of: fueling a motor vehicle with gasoline by discharging gasoline into a fill opening or filler pipe of a tank of said vehicle through a fuel outlet conduit of a nozzle; emitting gasoline vapors from said tank during said fueling; substantially collecting said vapors during said fueling with a vapor return conduit of said nozzle and passing said vapors through said vapor return conduit in counter current flow relationship to said discharging gasoline in said fuel conduit; conveying said vapors from said vapor return conduit to a vapor return hose; at least some of said vapors condensing to form condensate in said vapor return hose; substantially removing said condensate from said vapor return hose during said fueling with a condensate pickup tube from said nozzle by passing said condensate through said condensate pickup tube in counter current flow relationship to said conveying vapors in said vapor return hose; sensing the presence of gasoline with a liquid sensing tube in said vapor return conduit of said nozzle between inner and outer spouts of said nozzle to detect when said tank of said vehicle is filled with said fuel conduit being within the inner spout of said nozzle; and automatically shutting off said fueling and condensate removing when said liquid sensing tube detects when said tank of said vehicle is filled and fuel enters said vapor return conduit.

  16. Marine Vibrio Species Produce the Volatile Organic Compound Acetone

    OpenAIRE

    Nemecek-Marshall, M; Wojciechowski, C; Kuzma, J.; Silver, G. M.; Fall, R.

    1995-01-01

    While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine...

  17. Synthesis and characterization of carbon nanofilms for chemical sensing

    Science.gov (United States)

    Kumar, Vivek

    Carbon nanofilms obtained by high temperature graphitization of diamond surface in inert atmospheres or vacuum are modified by treatment in plasma of different precursor gases. At temperatures above 1000 °C, a stable conductive film of thickness between 10 - 100 nm and specific resistivity 10-3-10-4 Ωm, depending upon the heating conditions and the growth atmosphere, is formed on diamond surface. A gray, thin film of high surface resistivity is obtained in high vacuum, while at low vacuum (below 10-4 mbar), a thick black film of low surface resistivity forms. It is observed that the exposure to plasma reduces the surface conductance of carbon nanofilms as result of a partial removal of carbon and the plasma-stimulated amorphization. The rate of the reduction of conductance and hence the etching ability of plasma depends on the type of precursor gas. Hydrogen reveals the strongest etching ability, followed by oxygen and argon, whereas SF6 is ineffective. The carbon nanofilms show significant sensitivity of their electrical conductance to temperature and exposure to the vapors of common organic compounds. The oxygen plasma treated films exhibit selective response to acetone and water vapors. The fast response and recovery of the conductance are the features of the carbon nanofilms. The plasma-treated carbon nanofilm on graphitized diamond surface is discussed as a promising sensing material for development of all-carbon chemical sensors, which may be suitable for biological and medical applications. An alternative approach of fabrication of temperature and chemical sensitive carbon nanofilms on insulating substrates is proposed. The films are obtained by direct deposition of sputtered carbon on highly polished quartz substrates followed by subsequent annealing at temperatures above 400 °C. It is observed that the as-deposited films are essentially amorphous, while the heating induces irreversible structural ordering and gradual conversion of amorphous carbon in

  18. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  19. Sensing the Vapors of Truth.

    Science.gov (United States)

    Berger, Peter N.

    1998-01-01

    Describes the story told in Lois Lowry's novel for young adults, "The Giver." Notes also the hyperbolic description of books on their book jackets. Suggests seven activities for stimulating student response to the book. (SR)

  20. Antimutagenicity of an acetone extract of yogurt.

    Science.gov (United States)

    Nadathur, S R; Gould, S J; Bakalinsky, A T

    1995-04-01

    Reconstituted non-fat dry milk powder, fermented by a mixture of Streptococcus thermophilus CH3 and Lactobacillus bulgaricus 191R to produce yogurt, was freeze-dried and extracted in acetone. After evaporation of the acetone, the extract was dissolved in dimethyl sulfoxide (DMSO) and tested for antimutagenicity. In the Ames test, significant dose-dependent activity was observed against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitro-quinoline-N-oxide (4NQO), 3,2'-dimethyl-4-aminobiphenyl (DMAB), 9,10-dimethyl-1,2-benz[a]anthracene (DMBA), and 3-amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2). Weak activity was observed against 1,2,7,8-diepoxyoctane (DEO), and no activity was observed against methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), or aflatoxin B1 (AFB1). In a related assay (Saccharomyces cerevisiae D7), significant antimutagenic activity was detected against MNNG and 4NQO. Activity against the experimental colon carcinogens MNNG and DMAB was examined further, as assayed in the Ames test (Salmonella typhimurium TA100). Compounds responsible for both activities were less soluble in aqueous solutions than in DMSO. Adjustment of yogurt pH to 3, 7.6, or 13 prior to freeze-drying and acetone extraction did not significantly alter the amount of anti-MNNG activity recovered. In contrast, extractability of anti-DMAB activity was significantly greater at acidic pH. Conjugated linoleic acid, a known dairy anticarcinogen, failed to inhibit mutagenesis caused by either mutagen, suggesting that other yogurt-derived compound(s) are responsible. Unfermented milk was treated with lactic acid, yogurt bacteria without subsequent growth, or both, to determine if formation of antimutagenic activity required bacterial growth. Extracts of the milk treatments exhibited the same weak antimutagenicity observed in unfermented milk, approximately 2.5-fold less than in the yogurt extracts, suggesting that antimutagenic activity is associated with bacterial

  1. Nanostructure Engineered Chemical Sensors for Hazardous Gas and Vapor Detection

    Science.gov (United States)

    Li, Jing; Lu, Yijiang

    2005-01-01

    A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs) and metal oxides nanowires or nanobelts, on a pair of interdigitated electrodes (IDE) processed with a silicon based microfabrication and micromachining technique. The IDE fingers were fabricated using thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to hazardous gases and vapors, such as acetone, benzene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing in our sensor platform can be understood by electron modulation between the nanostructure engineered device and gas molecules. As a result of the electron modulation, the conductance of nanodevice will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost.

  2. Apparatus and method for monitoring breath acetone and diabetic diagnostics

    Science.gov (United States)

    Duan, Yixiang; Cao, Wenqing

    2008-08-26

    An apparatus and method for monitoring diabetes through breath acetone detection and quantitation employs a microplasma source in combination with a spectrometer. The microplasma source provides sufficient energy to produce excited acetone fragments from the breath gas that emit light. The emitted light is sent to the spectrometer, which generates an emission spectrum that is used to detect and quantify acetone in the breath gas.

  3. Inhalation developmental toxicology studies: Teratology study of acetone in mice and rats: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mast, T.J.; Evanoff, J.J.; Rommereim, R.L.; Stoney, K.H.; Weigel, R.J.; Westerberg, R.B.

    1988-11-01

    Acetone, an aliphatic ketone, is a ubiquitous industrial solvent and chemical intermediate; consequently, the opportunity for human exposure is high. The potential for acetone to cause developmental toxicity was assessed in Sprague-Dawley rats exposed to 0, 440, 2200, or 11000 ppm, and in Swiss (CD-1) mice exposed to 0, 440, 2200, and 6600 ppm acetone vapors, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and approx.32 positively mated rats or mice. Positively mated mice were exposed on days 6-17 of gestation (dg), and rats on 6-19 dg. The day of plug or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. 46 refs., 6 figs., 27 tabs.

  4. Using remotely sensed data from AIRS to estimate the vapor flux on the Greenland ice sheet: Comparisons with observations and a regional climate model

    Science.gov (United States)

    Boisvert, Linette N.; Lee, Jae N.; Lenaerts, Jan T. M.; Noël, Brice; Broeke, Michiel R.; Nolin, Anne W.

    2017-01-01

    Mass loss from the Greenland ice sheet (GrIS) in recent years has been dominated by runoff from surface melt. It is currently being studied extensively, while little interest has been given to the smallest component of surface mass balance (SMB): the vapor flux. Although poorly understood, it is not negligible and could potentially play a larger role in SMB in a warming climate where temperature, relative humidity, and precipitation changes remain uncertain. Here we present an innovative approach to estimate the vapor flux using the Atmospheric Infrared Sounder (AIRS) version 6 data and a modified vapor flux model (BMF13) over the GrIS between 2003 and 2014. One modification to the BMF13 model includes a new Multiangle Imaging SpectroRadiometer surface aerodynamic roughness product, which likely produces more accurate estimates of the drag coefficient on the ice sheet. When comparing AIRS data with GC-Net and Programme for Monitoring of the Greenland Ice Sheet automatic weather station observations of skin temperature, near-surface air temperature, and humidity, they agree within 2 K, 2.68 K, and 0.34 g kg-1. Largest differences occur in the ablation zone where there is significant subgrid heterogeneity. Overall, the average vapor flux from the GrIS between 2003 and 2014 was found to be 14.6 ± 3.6 Gt yr-1. No statistically significant trends were found during the data record. This data set is compared to the Regional Atmospheric Climate Model (RACMO2.3) vapor flux, and BMF13 produced smaller vapor fluxes in the summer ( 0.05 Gt d-1) and slightly more deposition in the winter ( 9.4 × 10-3 Gt d-1). Annually, differences between BMF13 and RACMO2.3 were only 30 ± 15%.

  5. Hydrothermal Synthesis of ZnO Structures Formed by High-Aspect-Ratio Nanowires for Acetone Detection.

    Science.gov (United States)

    Cao, Zhen; Wang, Yong; Li, Zhanguo; Yu, Naisen

    2016-12-01

    Snowflake-like ZnO structures originating from self-assembled nanowires were prepared by a low-temperature aqueous solution method. The as-grown hierarchical ZnO structures were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The results showed that the snowflake-like ZnO structures were composed of high-aspect-ratio nanowires. Furthermore, gas-sensing properties to various testing gases of 10 and 50 ppm were measured, which confirms that the ZnO structures were of good selectivity and response to acetone and could serve for acetone sensor to detect low-concentration acetone.

  6. Reduction of acetone to isopropanol using producer gas fermenting microbes.

    Science.gov (United States)

    Ramachandriya, Karthikeyan D; Wilkins, Mark R; Delorme, Marthah J M; Zhu, Xiaoguang; Kundiyana, Dimple K; Atiyeh, Hasan K; Huhnke, Raymond L

    2011-10-01

    Gasification-fermentation is an emerging technology for the conversion of lignocellulosic materials into biofuels and specialty chemicals. For effective utilization of producer gas by fermenting bacteria, tar compounds produced in the gasification process are often removed by wet scrubbing techniques using acetone. In a preliminary study using biomass generated producer gas scrubbed with acetone, an accumulation of acetone and subsequent isopropanol production was observed. The effect of 2 g/L acetone concentrations in the fermentation media on growth and product distributions was studied with "Clostridium ragsdalei," also known as Clostridium strain P11 or P11, and Clostridium carboxidivorans P7 or P7. The reduction of acetone to isopropanol was possible with "C. ragsdalei," but not with P7. In P11 this reaction occurred rapidly when acetone was added in the acidogenic phase, but was 2.5 times slower when added in the solventogenic phase. Acetone at concentrations of 2 g/L did not affect the growth of P7, but ethanol increased by 41% and acetic acid concentrations decreased by 79%. In the fermentations using P11, growth was unaffected and ethanol concentrations increased by 55% when acetone was added in the acidogenic phase. Acetic acid concentrations increased by 19% in both the treatments where acetone was added. Our observations indicate that P11 has a secondary alcohol dehydrogenase that enables it to reduce acetone to isopropanol, while P7 lacks this enzyme. P11 offers an opportunity for biological production of isopropanol from acetone reduction in the presence of gaseous substrates (CO, CO₂, and H₂).

  7. Dissociative electron attachment studies on acetone

    Energy Technology Data Exchange (ETDEWEB)

    Prabhudesai, Vaibhav S., E-mail: vaibhav@tifr.res.in; Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E. [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

    2014-10-28

    Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0–20 eV. H{sup −} is found to be the most dominant fragment followed by O{sup −} and OH{sup −} with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H{sup −} and O{sup −} fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

  8. Facile synthesis of porous ZnO microbelts and analysis of their gas-sensing property

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jiarui, E-mail: jrhuang@mail.anhu.edu.cn; Shi, Chengcheng; Fu, Guijun; Sun, Pingping; Wang, Xinyue; Gu, Cuiping, E-mail: cpgu2008@mail.ahnu.edu.cn

    2014-04-01

    Porous ZnO microbelts were achieved using a facile chemical solution method combined with subsequent calcination. The micro-nanostructures were characterized through X-ray diffraction, field emission scanning electron microscopy, thermogravimetric-differential thermal analysis, and Brunauer–Emmett–Teller N{sub 2} adsorption-desorption analyses, among others. The BET surface area of the porous ZnO microbelts was calculated at 23.0 m² g{sup −1}. Furthermore, the gas sensing properties of the as-prepared porous ZnO microbelts were investigated using volatile organic compounds. Compared with ZnO microflowers, the porous ZnO microbelts exhibited higher response with certain organic vapors, such as formaldehyde, acetone, and ethanol. The responses to 100 ppm formaldehyde, acetone, and ethanol were 45.7, 40.6, and 38.4, respectively, at a working temperature of 300 °C. The results showed that the porous ZnO microbelts are highly promising candidates for gas sensing applications. - Highlights: • Zinc glycinate monohydrate microwires were obtained by a chemical solution method. • Porous ZnO microbelts were achieved after calcinations. • The porous ZnO microbelts exhibit superior gas-sensing property.

  9. Optical Properties of Sol-Gel Nb2O5 Films with Tunable Porosity for Sensing Applications

    Directory of Open Access Journals (Sweden)

    Rosen Georgiev

    2015-01-01

    Full Text Available Thin Nb2O5 films with tunable porosity are deposited by the sol-gel and evaporation induced self-assembly methods using organic template Pluronic PE6100 with different molar fractions with respect to NbCl5 used as a precursor for synthesis of Nb sol. Surface morphology and structure of the films are studied by Transmission Electron Microscopy and Selected Area Electron Diffraction. The optical characterization of the films is carried out through reflectance spectra measurements of the films deposited on silicon substrates and theoretical modeling in order to obtain refractive index, extinction coefficient, and thickness of the films. The overall porosity of the films and the amount of adsorbed acetone vapors in the pores are quantified by means of Bruggeman effective medium approximation using already determined optical constants. The sensing properties of the samples are studied by measuring both the reflectance spectra and room-temperature photoluminescence spectra prior to and after exposure to acetone vapors and liquid, respectively. The potential of using the studied mesoporous Nb2O5 films for chemooptical sensing is demonstrated and discussed.

  10. Effect of Cobalt Particle Size on Acetone Steam Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junming; Zhang, He; Yu, Ning; Davidson, Stephen; Wang, Yong

    2015-06-11

    Carbon-supported cobalt nanoparticles with different particle sizes were synthesized and characterized by complementary characterization techniques such as X-ray diffraction, N-2 sorption, acetone temperature-programmed desorption, transmission electron microscopy, and CO chemisorption. Using acetone steam reforming reaction as a probe reaction, we revealed a volcano-shape curve of the intrinsic activity (turnover frequency of acetone) and the CO2 selectivity as a function of the cobalt particle size with the highest activity and selectivity observed at a particle size of approximately 12.8nm. Our results indicate that the overall performance of acetone steam reforming is related to a combination of particle-size-dependent acetone decomposition, water dissociation, and the oxidation state of the cobalt nanoparticles.

  11. High-Pressure Solvent Vapor Annealing with a Benign Solvent To Rapidly Enhance the Performance of Organic Photovoltaics.

    Science.gov (United States)

    Jung, Buyoung; Kim, Kangmin; Eom, Yoomin; Kim, Woochul

    2015-06-24

    A high-pressure solvent vapor annealing (HPSVA) treatment is suggested as an annealing process to rapidly achieve high-performance organic photovoltaics (OPVs); this process can be compatible with roll-to-roll processing methods and uses a benign solvent: acetone. Solvent vapor annealing can produce an advantageous vertical distribution in the active layer; however, conventional solvent vapor annealing is also time-consuming. To shorten the annealing time, high-pressure solvent vapor is exposed on the active layer of OPVs. Acetone is a nonsolvent for poly(3-hexylthiophene-2,5-diyl) (P3HT), but it can dissolve small amounts of 1-(3-methoxycarbonyl)-propyl-1,1-phenyl-(6,6)C61 (PCBM). Acetone vapor molecules can penetrate into the active layer under high vapor pressure conditions to alter the morphology. HPSVA induces a PCBM-rich phase near the cathode and facilitates the transport of free charge carriers to the electrode. Although P3HT is not soluble in acetone, locally rearranged P3HT crystallites are generated. The performance of OPV films was enhanced after HPSVA; the film treated at 30 kPa for 10 s showed optimum performance. Additionally, this HPSVA method could be adapted for mass production because the temporary exposure of films to high-pressure acetone vapor in ambient conditions also improved performance.

  12. Vapor Bubbles

    Science.gov (United States)

    Prosperetti, Andrea

    2017-01-01

    This article reviews the fundamental physics of vapor bubbles in liquids. Work on bubble growth and condensation for stationary and translating bubbles is summarized and the differences with bubbles containing a permanent gas stressed. In particular, it is shown that the natural frequency of a vapor bubble is proportional not to the inverse radius, as for a gas bubble, but to the inverse radius raised to the power 2/3. Permanent gas dissolved in the liquid diffuses into the bubble with strong effects on its dynamics. The effects of the diffusion of heat and mass on the propagation of pressure waves in a vaporous bubbly liquid are discussed. Other topics briefly touched on include thermocapillary flow, plasmonic nanobubbles, and vapor bubbles in an immiscible liquid.

  13. Rational Design of a Nile Red/Polymer Composite Film for Fluorescence Sensing of Organophosphonate Vapors using Hydrogen Bond Acidic Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Levitsky, Igor (Altair Center); Krivoshlykov, Sergei G.(ALTAIR Center, LLC); Grate, Jay W.(BATTELLE (PACIFIC NW LAB))

    2000-12-01

    The solvatochromic dye Nile Red dispersed in selected hydrogen-bond acidic polymer matrices demonstrated strong fluorescence enhancement at the presence of dimethyl methylphosphonate (DMMP) vapors. Two hydrogen bond acidic polymers were examined as dye matrices, one with fluorinated alcohol groups on a polystyrene backbone (PSFA), and the other with fluorinated bisphenol groups alternating with oligodimethylsiloxane segments (BSP3). The combination of hydrogen-bond acidic polymer (a strong sorbent for DMMP) with the solvatochromic dye led to initial depression of the dye fluorescence and a significant red shift in the absorbance and fluorescence spectra. DMMP sorption changed the dye environment and dramatically altered the fluorescence spectrum and intensity, resulting in a strong fluorescence enhancement. It is proposed that this fluorescence enhancement is due to the competition set up between the dye and the sorbed vapor for polymeric hydrogen bonding sites. The highest responses were obtained with BSP3. DMMP detection has been demonstrated at sub-ppm DMMP concentrations, indicating very low detection limits compared to previous Nile Red/polymer matrix fluorescence vapor sensors. Nile Red/poly(methyl methacrylate) films prepared for comparisons exhibited substantially lower response to DMMP. Rational selection of polymers providing high sorption for DMMP and competition for hydrogen-bonding interactions with Nile Red yielded fluorescent films with high sensitivity.

  14. Synthesis of α-MoO3 nano-flakes by dry oxidation of RF sputtered Mo thin films and their application in gas sensing

    Science.gov (United States)

    Dwivedi, Priyanka; Dhanekar, Saakshi; Das, Samaresh

    2016-11-01

    Synthesis of orthorhombic (α) MoO3 nano-flakes by dry oxidation of RF sputtered Mo thin film is presented. The influence of Mo thickness variation, oxidation temperature and time on the crystallographic structure, surface morphology and roughness of MoO3 thin films was studied using SEM, AFM, XRD and Raman spectroscopy. A structural study shows that MoO3 is polycrystalline in nature with an α phase. It was noticed that oxidation temperature plays an important role in the formation of nano-flakes. The synthesis technique proposed is simple and suitable for large scale productions. The synthesis parameters were optimized for the fabrication of sensors. Chrome gold-based IDE (interdigitated electrodes) structures were patterned for the electrical detection of organic vapors. Sensors were exposed to wide range 5-100 ppm of organic vapors like ethanol, acetone, IPA (isopropanol alcohol) and water vapors. α-MoO3 nano-flakes have demonstrated selective sensing to acetone in the range of 10-100 ppm at 150 °C. The morphology of such nanostructures has potential in applications such as sensor devices due to their high surface area and thermal stability.

  15. Studies on the toxicity of acetone, acrolein and carbon dioxide on stored-product insects and wheat seed.

    Science.gov (United States)

    Pourmirza, Ali Asghar; Tajbakhsh, Mehdie

    2008-04-01

    In laboratory experiments toxicity of acetone, acrolein and carbon dioxide were investigated against 4 species of stored-product insects. In all experiments, acrolein was the most toxic compound to the tested insects. In empty-space trials, estimated LD50 values of acrolein for adults of Tribolium castaneum (Herbst) (Tenebrionidae), Rhizopertha dominica (F.) (Bostrychidae), Sitophilus oryzae L. (Curculionidae) and Oryzaephilus surinamensis L. (Silvanidae) were 7.26, 6.09, 6.37 and 5.65 microl L(-1), respectively. Penetration tests revealed that acetone and acrolein vapors could penetrate into the wheat mass and kill concealed insects in interkernel spaces. Comparison of LD50 values of acrolein between empty-space tests and penetration experiments indicated that the increase in penetration toxicity was 4.96, 4.54, 3.64 and 3.43-fold for T. castaneum, R. dominica, S. oryzae and O. surinamensis, respectively. The effect of carbon dioxide on the toxicity of acrolein and acetone was synergistic. In the hidden infestation trials, the acrolein vapors destroyed the developmental stages of S. oryzae concealed inside the wheat kernels and resulted in a complete control with concentration of 80 microl L(-1) for 24 h and subsequently observed during 8 weeks after the exposure. Wheat germination and plumule length was reduced following exposure to all doses of acrolein. Acetone and carbon dioxide were harmless to wheat seed viability. The mixture of carbon dioxide with acrolein can be considered as a potential fumigant for replacing methyl bromide or phosphine under ambient storage conditions specifically in empty-space fumigations.

  16. Raman lidar measurements of water vapor and aerosols during the atmospheric radiation measurement (ARM) remote clouds sensing (RCS) intensive observation period (IOP)

    Energy Technology Data Exchange (ETDEWEB)

    Melfi, S.H.; Starr, D.O`C.; Whiteman, D. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)] [and others

    1996-04-01

    The first Atmospheric Radiation Measurement (ARM) remote Cloud Study (RCS) Intensive Operations Period (IOP) was held during April 1994 at the Southern Great Plains (SGP) site. This experiment was conducted to evaluate and calibrate state-of-the-art, ground based remote sensing instruments and to use the data acquired by these instruments to validate retrieval algorithms developed under the ARM program.

  17. Viscosities and refractive indices of binary systems acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol

    Directory of Open Access Journals (Sweden)

    Živković Emila M.

    2014-01-01

    Full Text Available Viscosities and refractive indices of three binary systems, acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol, were measured at eight temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, 323.15K and at atmospheric pressure. From these data viscosity deviations and deviations in refractive index were calculated and fitted to the Redlich-Kister equation. The viscosity modelling was done by two types of models: predictive UNIFAC-VISCO and ASOG VISCO and correlative Teja-Rice and McAlister equations. The refractive indices of binary mixtures were predicted by various mixing rules and compared with experimental data. [Projekat Ministarstva nauke Republike Srbije, br. 172063

  18. Detection of TATP precursor acetone at trace levels using rf sputtered SnO2 thin film-based sensors

    Science.gov (United States)

    Chowdhuri, Arijit; Sharma, Anjali; Gupta, Vinay

    2011-05-01

    Emerging threats of improvised explosive devices (IEDs) and homemade explosives (HMEs) have created a demand for reliable and unambiguous recognition of constituent analytes. Triacetone triperoxide (TATP), a cyclic peroxide based explosive has become a weapon of choice [1] in the hands of resourceful urban insurgents mainly because of ease of manufacture with readily available precursor constituents (acetone and concentrated hydrogen peroxide). Failure of conventional EDDs due to absence of nitrogen compounds coupled with the fact that TATP exhibits no significant absorption in UV region and does not demonstrate fluorescence has confined its detection to IR and Raman spectroscopy besides some enzyme-based tests and mass spectrometry [2]. Hence there is an urgent need for highly sensitive technique with a fast response speed that can detect presence of TATP at extremely low vapour pressure and purposely camouflaged physically or under cross-contamination with interfering compounds. In the present work trace level (20 ppm) acetone (precursor of TATP) sensing characteristics of rf sputtered semiconducting SnO2 thin films having embedded Pt interdigital electrodes have been investigated. Specifically a fast response speed of 08 seconds is noted and sensing characteristics of bare SnO2 and catalyst-SnO2 hetero-structures are compared. Innovative catalyst dispersal technique is shown to enhance sensor response as also reduce response times. Novel sensing hetero-structures with reversible acetone detection capabilities are shown to provide a feasible alternative for real-field operation along with remote detection with limited sample size.

  19. Bis(tetraphenylphosphonium tetraiodidomanganate(II acetone monosolvate

    Directory of Open Access Journals (Sweden)

    Sven Lidin

    2010-03-01

    Full Text Available The title compound, (C24H20P2[MnI4]·(CH32CO, prepared from the reaction of manganese powder, iodine and tetraphenylphosphonium iodide in acetone shows a tetrahedral complex anion [Mn—I = 2.6868 (5–2.7281 (4 Å and I—Mn—I = 104.011 (13–116.164 (15°], two tetraphenylphosphonium cations and one molecule of acetone.

  20. Characterization of Acetone-Solution Casting Film of PMMA

    Institute of Scientific and Technical Information of China (English)

    Xue Feng; Fu Weiwen; Cheng Rongshi

    2006-01-01

    Acetone solution-casting films of poly(methylmethacrylate)were analyzed by differential scanning calorimetry and pyrolysis gas chromatography-mass spectroscopy under natural evaporation and ultrasonic vibration,respectively.Analytical results indicate that both the condensed structure of the polymer and the residue solvent in the films vary in different film-forming conditions and that the residuesolvated acetone in films prepared under natural evaporation is 12 times greater than that under ultrasonic vibration.

  1. Cross-Selectivity Enhancement of Poly(vinylidene fluoride-hexafluoropropylene-Based Sensor Arrays for Detecting Acetone and Ethanol

    Directory of Open Access Journals (Sweden)

    Ali Daneshkhah

    2017-03-01

    Full Text Available Two methods for cross-selectivity enhancement of porous poly(vinylidene fluoride-hexafluoropropylene (PVDF-HFP/carbon black (CB composite-based resistive sensors are provided. The sensors are tested with acetone and ethanol in the presence of humid air. Cross-selectivity is enhanced using two different methods to modify the basic response of the PVDF-HFP/CB sensing platform. In method I, the adsorption properties of PVDF-HFP/CB are altered by adding a polyethylene oxide (PEO layer or by treating with infrared (IR. In method II, the effects of the interaction of acetone and ethanol are enhanced by adding diethylene carbonate (DEC or PEO dispersed in DEC (PEO/DEC to the film. The results suggest the approaches used in method I alter the composite ability to adsorb acetone and ethanol, while in method II, they alter the transduction characteristics of the composite. Using these approaches, sensor relative response to acetone was increased by 89% compared with the PVDF-HFP/CB untreated film, whereas sensor relative response to ethanol could be decreased by 57% or increased by 197%. Not only do these results demonstrate facile methods for increasing sensitivity of PVDF-HFP/CB film, used in parallel they demonstrate a roadmap for enhancing system cross-selectivity that can be applied to separate units on an array. Fabrication methods, experimental procedures and results are presented and discussed.

  2. Acetone production with metabolically engineered strains of Acetobacterium woodii.

    Science.gov (United States)

    Hoffmeister, Sabrina; Gerdom, Marzena; Bengelsdorf, Frank R; Linder, Sonja; Flüchter, Sebastian; Öztürk, Hatice; Blümke, Wilfried; May, Antje; Fischer, Ralf-Jörg; Bahl, Hubert; Dürre, Peter

    2016-07-01

    Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation.

  3. Numerical Modeling and Experimental Validation by Calorimetric Detection of Energetic Materials Using Thermal Bimorph Microcantilever Array: A Case Study on Sensing Vapors of Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    Kang, Seok-Won; Fragala, Joe; Banerjee, Debjyoti

    2015-01-01

    Bi-layer (Au-Si3N4) microcantilevers fabricated in an array were used to detect vapors of energetic materials such as explosives under ambient conditions. The changes in the bending response of each thermal bimorph (i.e., microcantilever) with changes in actuation currents were experimentally monitored by measuring the angle of the reflected ray from a laser source used to illuminate the gold nanocoating on the surface of silicon nitride microcantilevers in the absence and presence of a designated combustible species. Experiments were performed to determine the signature response of this nano-calorimeter platform for each explosive material considered for this study. Numerical modeling was performed to predict the bending response of the microcantilevers for various explosive materials, species concentrations, and actuation currents. The experimental validation of the numerical predictions demonstrated that in the presence of different explosive or combustible materials, the microcantilevers exhibited unique trends in their bending responses with increasing values of the actuation current. PMID:26334276

  4. Numerical Modeling and Experimental Validation by Calorimetric Detection of Energetic Materials Using Thermal Bimorph Microcantilever Array: A Case Study on Sensing Vapors of Volatile Organic Compounds (VOCs

    Directory of Open Access Journals (Sweden)

    Seok-Won Kang

    2015-08-01

    Full Text Available Bi-layer (Au-Si3N4 microcantilevers fabricated in an array were used to detect vapors of energetic materials such as explosives under ambient conditions. The changes in the bending response of each thermal bimorph (i.e., microcantilever with changes in actuation currents were experimentally monitored by measuring the angle of the reflected ray from a laser source used to illuminate the gold nanocoating on the surface of silicon nitride microcantilevers in the absence and presence of a designated combustible species. Experiments were performed to determine the signature response of this nano-calorimeter platform for each explosive material considered for this study. Numerical modeling was performed to predict the bending response of the microcantilevers for various explosive materials, species concentrations, and actuation currents. The experimental validation of the numerical predictions demonstrated that in the presence of different explosive or combustible materials, the microcantilevers exhibited unique trends in their bending responses with increasing values of the actuation current.

  5. trans-Carbonylchloridobis(tri-p-tolylphosphinerhodium(I acetone solvate

    Directory of Open Access Journals (Sweden)

    Brian R. James

    2008-03-01

    Full Text Available The title compound, [RhCl(C21H21P2(CO]·C3H6O, was precipitated in trace yield from a reaction of RhCl(cod(THP with P(p-tol3 in a 1:1 acetone-d6/CD3OD solution under a hydrogen atmosphere [p-tol = p-tolyl, THP = tris(hydroxymethylphosphine, P(CH2OH3, and cod = 1,5-cyclooctadiene]. The complex displays a square-planar geometry around the RhI atom. The complex molecules and the acetone molecules are linked into a chain along the a axis by intermolecular C—H...Cl and C—H...O hydrogen bonds.

  6. Non-Isothermal Desolvation Kinetics of Erythromycin A Acetone Solvate

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The desolvation of erythromycin acetone solvate was investigated under non-isothermal conditions by a thermogravimetric analyzer. This paper emphasized the kinetic analysis of non-isothermal TG-DTA data by Achar method and Coats-Redfern method to fit various solid-state reaction models, and to achieve kinetic parameters of desolvation. The mechanism of thermal desolvation was evaluated using the kinetic compensation effect. The results show that kinetics of desolvation of erythromycin acetone solvate was compatible with the mechanism of a two-dimensional diffusion controlled and was best expressed by Valensi equation. Corresponding to the integral method and the differential method, the activation energy of desolvation of erythromycin acetone solvate was estimated to be 51.26-57.11 kJ/mol, and the pre-exponential factor was 8.077 × 106 s-1-4.326 × 107 s-1,respectively.

  7. Acetone Powder From Dormant Seeds of Ricinus communis L

    Science.gov (United States)

    Cavalcanti, Elisa D. C.; Maciel, Fábio M.; Villeneuve, Pierre; Lago, Regina C. A.; Machado, Olga L. T.; Freire, Denise M. G.

    The influence of several factors on the hydrolytic activity of lipase, present in the acetone powder from dormant castor seeds (Ricinus communis) was evaluated. The enzyme showed a marked specificity for short-chain substrates. The best reaction conditions were an acid medium, Triton X-100 as the emulsifying agent and a temperature of 30°C. The lipase activity of the acetone powder of different castor oil genotypes showed great variability and storage stability of up to 90%. The toxicology analysis of the acetone powder from genotype Nordestina BRS 149 showed a higher ricin (toxic component) content, a lower 2S albumin (allergenic compound) content, and similar allergenic potential compared with untreated seeds.

  8. Synthesis and Analysis of Resorcinol-Acetone Copolymer

    Directory of Open Access Journals (Sweden)

    Gen-ichi Konishi

    2009-01-01

    Full Text Available Synthesis and characterization of resorcinol-acetone copolymer is described. The polymer was prepared by trifluoroacetic acid-catalyzed polymerization of resorcinol with acetone. According to the 1H-NMR, 13C-NMR, and MALDI-TOF Mass spectra data, the obtained polymer had three types of repeating units: isopropylidene bridged-resorcinol, chromane ring, and spiro-shaped double chromane ring, indicating that polymerization proceeded via simultaneous addition-condensation and cyclization of resorcinol with acetone. The obtained polymer can be useful not only for the development of plastic materials such as thermosets, adhesives, and coatings but also for the synthesis of biomaterials such as antimicrobial agents, pesticides, and medicines.

  9. Design of PolyMUMPS device for diabetes screening via acetone vapor detection in exhaled breath

    Science.gov (United States)

    Rabih, Almur A. S.; Dennis, J. O.; Khir, M. H. Md; Ahmed, Mawahib Gafare; Mian, Muhammad Umer

    2016-11-01

    Diabetes is a chronic disease that occurs due to deficiency or improper use of insulin by body tissues. It is currently diagnosed invasively by measuring blood glucose. This paper reports modelling and simulation of a PolyMUMPS device proposed for a non-invasive screening of diabetes. The device is electromagnetically driven at its resonance frequency using Lorenz force, while the output is detected by capacitive means. The resonance frequency of the first mode was obtained by CoventorWare software and it was found to be 18.552 kHz compared to its modelled value of 17.211 kHz, within an error of 7.2 %. Maximum displacement of 8.35 µm and capacitance of 29.57 fF were obtained when the device was driven by applying 15 mA current and 50 mT magnetic field.

  10. Acetone Sensors Based on La~(3+) Doped ZnO Nano-rods Prepared by Solvothermal Method

    Institute of Scientific and Technical Information of China (English)

    Xiangfeng Chu; Xiaohua Zhu; Yongping Dong; Xiutao Ge; Shouquan Zhang; Wenqi Sun

    2012-01-01

    La3+ doped ZnO nano-rods with different doping concentration were prepared via solvothermal method.The doped ZnO nano-rods were characterized by X-ray diffraction(XRD) and scanning electron microscopy(SEM),respectively.The effect of La3+ doping on the gas-sensing properties was investigated.The results revealed that the sensor based on 6 mol% La3+ doped ZnO nano-rods exhibited high response to dilute acetone,and the responses to 0.01×10-6 acetone reached 2.4 when operating at 425 ℃.The response time and the recovery time for 0.01×10-6 acetone were only 16 and 3 s,respectively.

  11. Solvent vapor annealing of an insoluble molecular semiconductor

    KAUST Repository

    Amassian, Aram

    2010-01-01

    Solvent vapor annealing has been proposed as a low-cost, highly versatile, and room-temperature alternative to thermal annealing of organic semiconductors and devices. In this article, we investigate the solvent vapor annealing process of a model insoluble molecular semiconductor thin film - pentacene on SiO 2 exposed to acetone vapor - using a combination of optical reflectance and two-dimensional grazing incidence X-ray diffraction measurements performed in situ, during processing. These measurements provide valuable and new insight into the solvent vapor annealing process; they demonstrate that solvent molecules interact mainly with the surface of the film to induce a solid-solid transition without noticeable swelling, dissolving or melting of the molecular material. © 2010 The Royal Society of Chemistry.

  12. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach

    Directory of Open Access Journals (Sweden)

    Ateeq Rahman

    2011-01-01

    Full Text Available The catalytic hydrogenation of acetone is an important area of catalytic process to produce fine chemicals. Hydrogenation of acetone has important applications for heat pumps, fuel cells or in fulfilling the sizeable demand for the production of 2-propanol. Catalytic vapour phase hydrogenation of acetone has gained attention over the decades with variety of homogeneous catalysts notably Iridium, Rh, Ru complexes and heterogeneous catalysts comprising of Raney Nickel, Raney Sponge, Ni/Al2O3, Ni/SiO2, or Co-Al2O3, Pd, Rh, Ru, Re, or Fe/Al2O3 supported on SiO2 or MgO and even CoMgAl, NiMg Al layered double hydroxide, Cu metal, CuO, Cu2O. Nano catalysts are developed for actone reduction Ni maleate, cobalt oxide prepared in organic solvents. Author present a review on acetone hydrogenation under different conditions with various homogeneous and heterogeneous catalysts studied so far in literature and new strategies to develop economic and environmentally benign approach. ©2010 BCREC UNDIP. All rights reserved(Received: 16th June 2010, Revised: 18th October 2010; Accepted: 25th October 2010[How to Cite:Ateeq Rahman. (2010. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 113-126. doi:10.9767/bcrec.5.2.798.113-126][DOI: http://dx.doi.org/10.9767/bcrec.5.2.798.113-126 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/798

  13. A fully integrated standalone portable cavity ringdown breath acetone analyzer

    Science.gov (United States)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  14. Effect of using acetone and distilled water on the performance of open loop pulsating heat pipe (OLPHP) with different filling ratios

    Science.gov (United States)

    Rahman, Md. Lutfor; Afrose, Tonima; Tahmina, Halima Khatun; Rinky, Rumana Parvin; Ali, Mohammad

    2016-07-01

    Pulsating heat pipe (PHP) is a new innovation in the modern era of miniaturizes thermal management system for its higher heating and cooling capacity. The objective of this experiment is to observe the performance of open loop pulsating heat pipe using two fluids at different filling ratios. This OLPHP is a copper capillary tube of 2.5mm outer diameter and 2mm inner diameter. It consists of 8 loops where the evaporative section is 50mm, adiabatic section is 120mm and condensation section is 80mm. The experiment is conducted with distilled water and acetone at 40%, 50%, 60%, and 70% filling ratios where 0° (vertical) is considered as definite angle of inclination. Distilled water and acetone are selected as working fluids considering their different latent heat of vaporization and surface tension. It is found that acetone shows lower thermal resistance than water at all heat inputs. Best performance of acetone is attained at 70% filling ratio. Water displays better heat transfer capability at 50% filling ratio.

  15. Stage 2 vapor recovery system

    Energy Technology Data Exchange (ETDEWEB)

    Koch, W.H.; Strock, D.J.; Butkovich, M.S.; Hartman, H.B.

    1993-05-25

    A vapor recovery system is described, comprising: a set of elongated underground storage tanks, each storage tank containing a different grade of gasoline; vent pipes; a series of dispensing units; fuel flow lines; vapor return lines; an array of fuel pumps for pumping gasoline from said storage tanks to said dispenser units; an elongated condensate liquid pickup tube; an elongated inner spout providing a fuel conduit and having an outer tip defining a fuel outlet for discharging gasoline into a filler pipe of a motor vehicle tank during fueling; an outer spout assembly; extending into and engaging said spout-receiving socket, said outer spout assembly comprising an outer spout providing a vapor return conduit and defining apertures providing a vapor inlet spaced from said fuel outlet for withdrawing, removing, and returning a substantial amount of gasoline vapors emitted during said fueling; an elongated liquid sensing tube; a manually operable level; a flow control valve assembly; an automatic shutoff valve assembly; and a venturi sleeve assembly positioned in said venturi sleeve receiving chamber.

  16. Acetone Formation in the Vibrio Family: a New Pathway for Bacterial Leucine Catabolism

    OpenAIRE

    Nemecek-Marshall, Michele; Wojciechowski, Cheryl; William P. Wagner; Fall, Ray

    1999-01-01

    There is current interest in biological sources of acetone, a volatile organic compound that impacts atmospheric chemistry. Here, we determined that leucine-dependent acetone formation is widespread in the Vibrionaceae. Sixteen Vibrio isolates, two Listonella species, and two Photobacterium angustum isolates produced acetone in the presence of l-leucine. Shewanella isolates produced much less acetone. Growth of Vibrio splendidus and P. angustum in a fermentor with controlled aeration revealed...

  17. Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC

    NARCIS (Netherlands)

    Oosterkamp, M.J.; Boeren, S.; Atashgahi, S.; Plugge, C.M.; Schaap, P.J.; Stams, A.J.M.

    2015-01-01

    Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In

  18. Evaluation of unbound free heme in plant cells by differential acetone extraction.

    Science.gov (United States)

    Espinas, Nino A; Kobayashi, Koichi; Takahashi, Shigekazu; Mochizuki, Nobuyoshi; Masuda, Tatsuru

    2012-07-01

    Heme functions not only as a prosthetic group of hemoproteins but also as a regulatory molecule, suggesting the presence of 'free' heme. Classically, total non-covalently bound heme is extracted from plant samples with acidic acetone after removal of pigments with basic and neutral acetone. Earlier work proposed that free heme can be selectively extracted into basic acetone. Using authentic hemoproteins, we confirmed that acidic acetone can quantitatively extract heme, while no heme was extracted into neutral acetone. Meanwhile, a certain amount of heme was extracted into basic acetone from hemoglobin and myoglobin. Moreover, basic acetone extracted loosely bound heme from bovine serum albumin, implying that the nature of hemoproteins largely influences heme extraction into basic acetone. Using a highly sensitive heme assay, we found that basic and neutral acetone can extract low levels of heme from plant samples. In addition, neutral acetone quantitatively extracted free heme when it was externally added to plant homogenates. Furthermore, the level of neutral acetone-extractable heme remained unchanged by precursor (5-aminolevulinic acid) feeding, while increased by norflurazon treatment which abolishes chloroplast biogenesis. However, changes in these heme levels did not correlate to genomes uncoupled phenotypes, suggesting that the level of unbound free heme would not affect retrograde signaling from plastids to the nucleus. The present data demonstrate that the combination of single-step acetone extraction following a sensitive heme assay is the ideal method for determining total and free heme in plants.

  19. Multiphoton ionization of acetone-water clusters at 355 nm

    Institute of Scientific and Technical Information of China (English)

    WANG Reng; KONG Xiang-he; ZHANG Shu-dong; ZHANG Xia; FAN Xing-yan; ZHAO Shu-yan

    2006-01-01

    @@ The multiphoton ionization of acetone-water clusters were detected at 355 nm laser wavelength by using the time of flight mass spectrometer(TOF-MS).The experiments show that all products are protonated.Three main products such as (CH3COCH3)n-(H2O)n-2H+,(CH3COCH3)n-(H2O)n-1H+ and (CH3COCH3)n-(H2O)nH+ are concluded from the results.In order to study the equilibrium structures of the (CH3COCH3)n-(H2O)n-2H+,the ab-initio calculation is used on them.The experiment is even done when the volume rate of acetone to water is 1:2.

  20. Effect of Coadsorbed Water on the Photodecomposition of Acetone on TiO2(110)

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Michael A.

    2008-06-10

    The influence of coadsorbed water on the photodecomposition of acetone on TiO2 was examined using temperature programmed desorption (TPD) and the rutile TiO2(110) surface as a model photocatalyst. Of the two major influences ascribed to water in the heterogeneous photocatalysis literature (promotion via OH radical supply and inhibition due to site blocking), only the negative influence of water was observed. As long as the total water and acetone coverage was maintained well below the first layer saturation coverage (‘1 ML’), little inhibition of acetone photodecomposition was observed. However, as the total water+acetone coverage exceeded 1 ML, acetone was preferentially displaced from the first layer to physisorbed states by water and the extent of acetone photodecomposition attenuated. The displacement originated from water compressing acetone into high coverage regions where increased acetone-acetone repulsions caused displacement from the first layer. The immediate product of acetone photodecomposition was adsorbed acetate, which occupies twice as many surface sites per molecule as compared to acetone. Since the acetate intermediate was more stable on the TiO2(110) surface than either water or acetone (as gauged by TPD) and since its photodecomposition rate was less than that of acetone, additional surface sites were not opened up during acetone photodecomposition for previously displaced acetone molecules to re-enter the first layer. Results in this study suggest that increased molecular-level repulsions between organic molecules brought about by increased water coverage are as influential in the inhibiting effect of water on photooxidation rates as are water-organic repulsions.

  1. Excess protons in mesoscopic water-acetone nanoclusters

    OpenAIRE

    Semino, Rocío; Martí Rabassa, Jordi; Guàrdia Manuel, Elvira; Laria, Daniel

    2012-01-01

    We carried out molecular dynamics simulation experiments to examine equilibrium and dynamical characteristics of the solvation of excess protons in mesoscopic, [m:n] binary polar clusters comprising m = 50 water molecules and n = 6, 25, and 100 acetone molecules. Contrasting from what is found in conventional macroscopic phases, the characteristics of the proton solvation are dictated, to a large extent, by the nature of the concentration fluctuations prevailing within the clusters. At low ac...

  2. In vitro antimycobacterial activity of acetone extract of Glycyrrhiza glabra

    Directory of Open Access Journals (Sweden)

    Swapna S. Nair

    2015-08-01

    Full Text Available Context: Glycyrrhiza glabra (licorice has been used since ages as expectorant, antitussive and demulcent. G. glabra has been indicated in Ayurveda as an antimicrobial agent for the treatment of respiratory infections and tuberculosis. Aims: To evaluate the antimycobacterial activity of acetone extract of G. glabra by in vitro techniques. Methods: The anti-tubercular activity of acetone extract of G. glabra, obtained by Soxhlet extraction, was evaluated against Mycobacterium tuberculosis H37Rv (ATCC 27294. The in vitro anti-tubercular activity was determined by Resazurin Microtiter Plate Assay (REMA and colony count method. Further, the anti-tubercular activity of acetone extract of G. glabra was determined in human macrophage U937 cell lines and was compared against that of the standard drugs isoniazid, rifampicin and ethambutol. Results: G. glabra extract showed significant activity against Mycobacterium tuberculosis, when evaluated by REMA/colony count methods and in U937 human macrophage cell lines infected with Mycobacterium tuberculosis H37Rv. The activity of the extract was comparable to those of standard drugs. It was observed that the extract showed time and concentration dependent antimycobacterial activity. Conclusions: The present study reveals that G. glabra extract has promising anti-tubercular activity by preliminary in vitro techniques and in U937 macrophage cell line. Therefore, it has the definite potential to be developed as an affordable, cost-effective drug against tuberculosis.

  3. Template-free synthesis of hierarchical ZnFe2O4 yolk-shell microspheres for high-sensitivity acetone sensors

    Science.gov (United States)

    Zhou, Xin; Wang, Boqun; Sun, Hongbin; Wang, Chen; Sun, Peng; Li, Xiaowei; Hu, Xiaolong; Lu, Geyu

    2016-03-01

    Metal oxides with hierarchical microstructures have attracted tremendous attention with respect to their enhanced gas sensing properties. Herein, we reported the facile synthesis of hierarchical ZnFe2O4 yolk-shell microspheres via a template-free solvothermal strategy and the subsequent annealing and chemical etching process. Electron microscopy images undoubtedly demonstrated that the novel ZnFe2O4 architecture was constructed of a large number of nanosheet subunits with a thickness around 20 nm. As a proof-of-concept demonstration of the function, when evaluated as gas sensing materials, the as-prepared ZnFe2O4 yolk-shell microspheres manifested an extremely high response and a low detection limit to acetone at the operating temperature of 200 °C. Significantly, the response to 20 ppm acetone was retained well even after 200 cycles and continuous measurement for 30 days, indicating superior cyclability and long-term stability.Metal oxides with hierarchical microstructures have attracted tremendous attention with respect to their enhanced gas sensing properties. Herein, we reported the facile synthesis of hierarchical ZnFe2O4 yolk-shell microspheres via a template-free solvothermal strategy and the subsequent annealing and chemical etching process. Electron microscopy images undoubtedly demonstrated that the novel ZnFe2O4 architecture was constructed of a large number of nanosheet subunits with a thickness around 20 nm. As a proof-of-concept demonstration of the function, when evaluated as gas sensing materials, the as-prepared ZnFe2O4 yolk-shell microspheres manifested an extremely high response and a low detection limit to acetone at the operating temperature of 200 °C. Significantly, the response to 20 ppm acetone was retained well even after 200 cycles and continuous measurement for 30 days, indicating superior cyclability and long-term stability. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06308f

  4. A New Strategy for Humidity Independent Oxide Chemiresistors: Dynamic Self-Refreshing of In2 O3 Sensing Surface Assisted by Layer-by-Layer Coated CeO2 Nanoclusters.

    Science.gov (United States)

    Yoon, Ji-Wook; Kim, Jun-Sik; Kim, Tae-Hyung; Hong, Young Jun; Kang, Yun Chan; Lee, Jong-Heun

    2016-08-01

    The humidity dependence of the gas sensing characteristics of metal oxide semiconductors has been one of the greatest obstacles for gas sensor applications during the last five decades because ambient humidity dynamically changes with the environmental conditions. Herein, a new and novel strategy is reported to eliminate the humidity dependence of the gas sensing characteristics of oxide chemiresistors via dynamic self-refreshing of the sensing surface affected by water vapor chemisorption. The sensor resistance and gas response of pure In2 O3 hollow spheres significantly change and deteriorate in humid atmospheres. In contrast, the humidity dependence becomes negligible when an optimal concentration of CeO2 nanoclusters is uniformly loaded onto In2 O3 hollow spheres via layer-by-layer (LBL) assembly. Moreover, In2 O3 sensors LBL-coated with CeO2 nanoclusters show fast response/recovery, low detection limit (500 ppb), and high selectivity to acetone even in highly humid conditions (relative humidity 80%). The mechanism underlying the dynamic refreshing of the In2 O3 sensing surfaces regardless of humidity variation is investigated in relation to the role of CeO2 and the chemical interaction among CeO2 , In2 O3 , and water vapor. This strategy can be widely used to design high performance gas sensors including disease diagnosis via breath analysis and pollutant monitoring.

  5. On the relationship between acetone and carbon monoxide in different air masses

    Directory of Open Access Journals (Sweden)

    M. de Reus

    2003-01-01

    Full Text Available Carbon monoxide and acetone measurements are presented for five aircraft measurement campaigns at mid-latitudes, polar and tropical regions in the northern hemisphere. Throughout all campaigns, free tropospheric air masses, which were influenced by anthropogenic emissions, showed a similar linear relation between acetone and CO, with a slope of 21-25 pptv acetone/ppbv CO. Measurements in the anthropogenically influenced marine boundary layer revealed a slope of 13-16 pptv acetone/ppbv CO. The different slopes observed in the marine boundary layer and the free troposphere indicate that acetone is emitted by the ocean in relatively clean air masses and taken up by the ocean in polluted air masses. In the lowermost stratosphere, a good correlation between acetone and CO was observed as well, however, with a much smaller slope (~5 pptv acetone/ppbv CO compared to the troposphere. This is caused by the longer photochemical lifetime of CO compared to acetone in the lower stratosphere, due to the increasing photolytic loss of acetone and the decreasing OH concentration with altitude. No significant correlation between acetone and CO was observed over the tropical rain forest due to the large direct and indirect biogenic emissions of acetone. The common slopes of the linear acetone-CO relation in various layers of the atmosphere, during five field experiments, makes them useful for model calculations. Often a single observation of the acetone-CO correlation, determined from stratospheric measurements, has been used in box model applications. This study shows that different slopes have to be considered for marine boundary layer, free tropospheric and stratospheric air masses, and that the acetone-CO relation cannot be used for air masses which are strongly influenced by biogenic emissions.

  6. Insights into Acetone Photochemistry on Rutile TiO2(110). 1. Off-Normal CH3 Ejection from Acetone Diolate.

    Energy Technology Data Exchange (ETDEWEB)

    Petrik, Nikolay G.; Henderson, Michael A.; Kimmel, Gregory A.

    2015-06-04

    Thermal- and photon-stimulated reactions of acetone co-adsorbed with oxygen on rutile TiO2(110) surface are studied with infrared reflection-adsorption spectroscopy (IRAS) combined with temperature programmed desorption and angle-resolved photon stimulated desorption. IRAS results show that n2-acetone diolate ((CH3)2COO) is produced via thermally-activated reactions between the chemisorbed oxygen with co-adsorbed acetone. Formation of acetone diolate is also consistent with 18O / 16O isotopic exchange experiments. During UV irradiation at 30 K, CH3 radicals are ejected from the acetone diolate with a distribution that is peaked at .-. +- 66 degrees from the surface normal along the azimuth (i.e. perpendicular to the rows of bridging oxygen and Ti5c ions). This distribution is also consistent with the orientation of the C–CH3 bonds in the n2-acetone diolate on TiO2(110). The acetone diolate peaks disappear from the IRAS spectra after UV irradiation and new peaks are observed and associated with n2-acetate. The data presented here demonstrate direct signatures of the proposed earlier 2-step mechanism for acetone photooxidation on TiO2(110)

  7. Research of remote sensing technology of atmospheric water vapor by using ground-based GPS and application system of meteorological operations%地基GPS水汽监测技术及气象业务化应用系统的研究

    Institute of Scientific and Technical Information of China (English)

    李国平

    2011-01-01

    本研究建立了川渝地区地基GPS(global positioning system,全球定位系统)遥感水汽的本地化计算模型,开发出GPS遥感水汽的计算软件包,开展了局域地基GPS观测网遥感大气水汽的试验及业务应用,反演出30 min间隔的高时间分辨率GPS可降水量序列。评估了反演精度,研究了GPS水汽产品在气象业务应用的可行性。研发了可搭建在MICAPS(meteorological information comprehensive analysis and process system)平台上的地基G%This study established local computing model of remote sensing water vapor by using ground-based GPS(global positioning system) in the region of Sichuan-Chongqing,and developed computing software packages of GPS remote sensing water vapor.Then the experiment and operational application of remote sensing water vapor by using ground-based GPS in this local network was done,by which the high time resolution GPS precipitable water vapor(PWV) sequence of 30 min intervals was derived.This paper also gives the assessment of the retrieval accuracy,as well as the feasibility of meteorological operations application of GPS water vapor products.The major results of this study include developing the operations application system of remote sensing atmospheric water vapor by using ground-based GPS,which can be build on the MICAPS(meteorological information comprehensive analysis and process system) as an operational application system,and realizing the real-time transmission,data solution,deriving of PWV by a local ground-based GPS network and visualization of GPS water vapor products.This meteorological operations system played a unique role in the heavy rain,blizzard and other severe weather forecast in its trial-run.Systematical study of the temporal variation,horizontal distribution of GPS-PWV was done by our research group.Furthermore,the relationship between PWV derived by GPS among surface air temperature,pressure,specific humidity,solar radiation

  8. Phase transitions of amorphous solid acetone in confined geometry investigated by reflection absorption infrared spectroscopy.

    Science.gov (United States)

    Shin, Sunghwan; Kang, Hani; Kim, Jun Soo; Kang, Heon

    2014-11-26

    We investigated the phase transformations of amorphous solid acetone under confined geometry by preparing acetone films trapped in amorphous solid water (ASW) or CCl4. Reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) were used to monitor the phase changes of the acetone sample with increasing temperature. An acetone film trapped in ASW shows an abrupt change in the RAIRS features of the acetone vibrational bands during heating from 80 to 100 K, which indicates the transformation of amorphous solid acetone to a molecularly aligned crystalline phase. Further heating of the sample to 140 K produces an isotropic solid phase, and eventually a fluid phase near 157 K, at which the acetone sample is probably trapped in a pressurized, superheated condition inside the ASW matrix. Inside a CCl4 matrix, amorphous solid acetone crystallizes into a different, isotropic structure at ca. 90 K. We propose that the molecularly aligned crystalline phase formed in ASW is created by heterogeneous nucleation at the acetone-water interface, with resultant crystal growth, whereas the isotropic crystalline phase in CCl4 is formed by homogeneous crystal growth starting from the bulk region of the acetone sample.

  9. In situ FT-IR measurements of competitive vapor adsorption into porous thin films containing silica nanoparticles.

    Science.gov (United States)

    Evans, Charles R; Spurlin, Tighe A; Frey, Brian L

    2002-03-01

    Vapor adsorption into porous ultrathin films on a gold surface is investigated with in situ surface plasmon resonance (SPR) and polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS). The thin films are prepared by the electrostatic self-assembly of oppositely charged poly(L-lysine) (PL) and silica nanoparticles on a chemically modified gold surface. Characterization with ex situ SPR and PM-IRRAS demonstrates the buildup of multiple PL/SiO2 bilayers as well as an excellent correlation between the quantitative results from these two techniques. In situ vapor adsorption experiments with these thin films show evidence of porosity, reproducibility, and rapid reversibility. Exposure to acetone vapor (P/P0 = 0.032) causes the film to adsorb 9% acetone by volume, which corresponds to coverage of approximately one-half of the silica nanoparticle surface area. In situ PM-IRRAS provides much information about the molecular interactions occurring in the film upon adsorption or desorption of vapors. Dosing with a mixture of vapors leads to a competition for adsorption into the film, and PM-IRRAS results show that acetone slightly outcompetes nitromethane. These experiments with nanoparticle thin films demonstrate the advantages of using in situ PM-IRRAS for studying reversible adsorption in the presence of vapor mixtures.

  10. Aldol Condensation of Citral with Acetone on Basic Solid Catalysts

    Directory of Open Access Journals (Sweden)

    NODA C.

    1998-01-01

    Full Text Available The catalytic performance of solids with basic properties, such as CaO, MgO and hydrotalcites, was evaluated in the aldol condensation of citral and acetone, the first step in the synthesis of ionones from citral. The best results were obtained with CaO and hydrotalcite with high conversions (98% and selectivities (close to 70% for the main product observed for both of the catalyst. Such pseudoionone yields were greater than those reported in the literature for the homogeneous reaction.

  11. Saving Energy and Reducing Emission When Recycling Acetone during the Production of Soy Phospholipid

    Institute of Scientific and Technical Information of China (English)

    Liu Daicheng; Wang Yan; Tao Yinhua

    2008-01-01

    Acetone, which is volatile, flammable, toxic, expen-sive and causing serious air pollution, is often used as extracting solvent in the production of powdery soy phospholipid. Recycling and reusing acetone is the key of reducing the cost of production. Therefore, saving energy and reducing emission when recycling acetone are the most important technologies during the production of phospholipid. On the basis of the productivity of powdery phospholipid being 2.4 t every day, 43.2 t acetone is reused every 8 h and the total volume of acetone gas emitted is 450.75 m3 (about 901.5 kg). According to the current price of acetone, the lost money is about 7212 yuan RMB.

  12. The Effect of Fluorocarbon Surfactant Additives on the Effective Viscosity of Acetone Solutions of Cellulose Diacetate,

    Science.gov (United States)

    2014-09-26

    34 FOREIGN TECHNOLOGY DIVISION i00 Lfl .. THE EFFECT OF FLUOROCARBON SURFACTANT ADDITIVES ON THE EFFECTIVE VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE ...ADDITIVES ON TH~ .. t- ’_ ition EFFECTIVE VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE DIACETATE D~rbt~l By: L.A. Shits, N. Yu. Kal’nova Codesuton English...VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE DIACETATE L. A. Shits, N. Yu. Kal’nova (Institute of Physical Chemistry of the AS USSR, Moscow) ! - The

  13. Fluorometric biosniffer (biochemical gas sensor) for breath acetone as a volatile indicator of lipid metabolism

    Science.gov (United States)

    Mitsubayashi, Kohji; Chien, Po-Jen; Ye, Ming; Suzuki, Takuma; Toma, Koji; Arakawa, Takahiro

    2016-11-01

    A fluorometric acetone biosniffer (biochemical gas sensor) for assessment of lipid metabolism utilizing reverse reaction of secondary alcohol dehydrogenase was constructed and evaluated. The biosniffer showed highly sensitivity and selectivity for continuous monitoring of gaseous acetone. The measurement of breath acetone concentration during fasting and aerobic exercise were also investigated. The acetone biosniffer provides a novel analytical tool for noninvasive evaluation of human lipid metabolism and it is also expected to use for the clinical and physiological applications such as monitoring the progression of diabetes.

  14. Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

    Institute of Scientific and Technical Information of China (English)

    FANG,Yu(房喻); YIN,Yi-Qing(尹艺青); HU,Dao-Dao(胡道道); GAO,Gai-Ling(高改玲)

    2002-01-01

    The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques. It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes. The aggregates are not solvolyzed in acetone, and do not take part in any chemical reactions either. It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone. The aggregation is reversible, and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.

  15. The Effectof Temperature on the Dynmaic Viscosity of Acetone Sunflower-Seed Oil Mixtures

    OpenAIRE

    TOPALLAR, Hüseyin; BAYRAK, Yüksel

    1998-01-01

    The effect of acetone on the dynamic viscosity of sunflower-seed oil was studied under a dynamic heating regime at temeparuters ranging from 25oC to 50oC at 5oC intervals. Acetone dramatically reduced the viscosity of sunflower-seed oil. The reduction of viscosity was far less with further addition of acetone. A linear relationship was found between the density of sunflower-seed oil and temperature. The influence of a solvent on the density of the sunflower-seed oil/acetone solution can be ac...

  16. Recent Progresses in Atmospheric Remote Sensing Research in China-- Chinese National Report on Atmospheric Remote Sensing Research in China during 1999-2003

    Institute of Scientific and Technical Information of China (English)

    邱金桓; 陈洪滨

    2004-01-01

    Progresses of atmospheric remote sensing research in China during 1999-2003 are summarily introduced.This research includes: (1) microwave remote sensing of the atmosphere; (2) Lidar remote sensing; (3)remote sensing of aerosol optical properties; and (4) other research related to atmospheric remote sensing,including GPS remote sensing of precipitable water vapor and radiation model development.

  17. Evaluating the Potential Importance of Monoterpene Degradation for Global Acetone Production

    Science.gov (United States)

    Kelp, M. M.; Brewer, J.; Keller, C. A.; Fischer, E. V.

    2015-12-01

    Acetone is one of the most abundant volatile organic compounds (VOCs) in the atmosphere, but estimates of the global source of acetone vary widely. A better understanding of acetone sources is essential because acetone serves as a source of HOx in the upper troposphere and as a precursor to the NOx reservoir species peroxyacetyl nitrate (PAN). Although there are primary anthropogenic and pyrogenic sources of acetone, the dominant acetone sources are thought to be from direct biogenic emissions and photochemical production, particularly from the oxidation of iso-alkanes. Recent work suggests that the photochemical degradation of monoterpenes may also represent a significant contribution to global acetone production. We investigate that hypothesis using the GEOS-Chem chemical transport model. In this work, we calculate the emissions of eight terpene species (α-pinene, β-pinene, limonene, Δ3-carene, myrcene, sabinene, trans-β-ocimene, and an 'other monoterpenes' category which contains 34 other trace species) and couple these with upper and lower bound literature yields from species-specific chamber studies. We compare the simulated acetone distributions against in situ acetone measurements from a global suite of NASA aircraft campaigns. When simulating an upper bound on yields, the model-to-measurement comparison improves for North America at both the surface and in the upper troposphere. The inclusion of acetone production from monoterpene degradation also improves the ability of the model to reproduce observations of acetone in East Asian outflow. However, in general the addition of monoterpenes degrades the model comparison for the Southern Hemisphere.

  18. Acetone-CO enhancement ratios in the upper troposphere based on 7 years of CARIBIC data: new insights and estimates of regional acetone fluxes

    Science.gov (United States)

    Fischbeck, Garlich; Bönisch, Harald; Neumaier, Marco; Brenninkmeijer, Carl A. M.; Orphal, Johannes; Brito, Joel; Becker, Julia; Sprung, Detlev; van Velthoven, Peter F. J.; Zahn, Andreas

    2017-02-01

    Acetone and carbon monoxide (CO) are two important trace gases controlling the oxidation capacity of the troposphere; enhancement ratios (EnRs) are useful in assessing their sources and fate between emission and sampling, especially in pollution plumes. In this study, we focus on in situ data from the upper troposphere recorded by the passenger-aircraft-based IAGOS-CARIBIC (In-service Aircraft for a Global Observing System-Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) observatory over the periods 2006-2008 and 2012-2015. This dataset is used to investigate the seasonal and spatial variation of acetone-CO EnRs. Furthermore, we utilize a box model accounting for dilution, chemical degradation and secondary production of acetone from precursors. In former studies, increasing acetone-CO EnRs in a plume were associated with secondary production of acetone. Results of our box model question this common presumption and show increases of acetone-CO EnR over time without taking secondary production of acetone into account. The temporal evolution of EnRs in the upper troposphere, especially in summer, is not negligible and impedes the interpretation of EnRs as a means for partitioning of acetone and CO sources in the boundary layer. In order to ensure that CARIBIC EnRs represent signatures of source regions with only small influences by dilution and chemistry, we limit our analysis to temporal and spatial coherent events of high-CO enhancement. We mainly focus on North America and Southeast Asia because of their different mix of pollutant sources and the good data coverage. For both regions, we find the expected seasonal variation in acetone-CO EnRs with maxima in summer, but with higher amplitude over North America. We derive mean (± standard deviation) annual acetone fluxes of (53 ± 27) 10-13 kg m-2 s-1 and (185 ± 80) 10-13 kg m-2 s-1 for North America and Southeast Asia, respectively. The derived flux for North America

  19. Recent trends in acetone, butanol, and ethanol (ABE production

    Directory of Open Access Journals (Sweden)

    Keikhosro Karim

    2015-12-01

    Full Text Available Among the renewable fuels considered as a suitable substitute to petroleum-based gasoline, butanol has attracted a great deal of attention due to its unique properties. Acetone, butanol, and ethanol (ABE can be produced biologically from different substrates, including sugars, starch, lignocelluloses, and algae. This process was among the very first biofuel production processes which was commercialized during the First World War. The present review paper discusses the different aspects of the ABE process and the recent progresses made. Moreover, the microorganisms and the biochemistry of the ABE fermentation as well as the feedstocks used are reviewed. Finally, the challenges faced such as low products concentration and products` inhibitory effects on the fermentation are explained and different possible solutions are presented and reviewed.

  20. Seasonal variability of upper tropospheric acetone using ACE-FTS observations and LMDz-INCA model simulations

    Science.gov (United States)

    Dufour, Gaëlle; Harrison, Jeremy; Szopa, Sophie; Bernath, Peter

    2014-05-01

    The vertically-resolved distributions of oxygenated organic compounds (oVOCs) are mainly inferred from surface and airborne measurements with limited spatial and temporal coverage. This results in a limited understanding of the atmospheric budget of these compounds and of their impact on the upper tropospheric chemistry. In the last decade, satellite observations which complement in-situ measurements have become available, providing global distributions of several oVOCs. For example, Scisat-1, also known as the Atmospheric Chemistry Experiment (ACE) has measured several oVOCs including methanol and formaldehyde. ACE is a Canadian-led satellite mission for remote sensing of the Earth's atmosphere that has been in operation since 2004. The primary instrument on board is a Fourier transform spectrometer (FTS) featuring broad spectral coverage in the infrared (750-4400 cm-1) with high spectral resolution (0.02 cm-1). The FTS instrument can measure down to 5 km altitude with a high signal-to-noise ratio using solar occultation. The ACE-FTS has the ability to measure seasonal and height-resolved distributions of minor tropospheric constituents on a near-global scale and provides the opportunity to evaluate our understanding of important atmospheric oxygenated organic species. ACE-FTS acetone retrievals will be presented. The spatial distribution and seasonal variability of acetone will be described and compared to LMDz-INCA model simulations.

  1. Weak carbonyl-methyl intermolecular interactions in acetone clusters explored by IR plus VUV spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Jiwen [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China); Hu, Yongjun, E-mail: yjhu@scnu.edu.cn [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China); Xie, Min [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China); Bernstein, Elliot R. [Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872 (United States)

    2012-09-11

    Highlights: Black-Right-Pointing-Pointer The carbonyl overtone of acetone clusters is observed by IR-VUV spectroscopy. Black-Right-Pointing-Pointer Acetone molecules in the dimer are stacked with an antiparallel way. Black-Right-Pointing-Pointer The structure of the acetone trimer and the tetramer are the cyclic structures. Black-Right-Pointing-Pointer The carbonyl groups would interact with the methyl groups in acetone clusters. Black-Right-Pointing-Pointer These weak interactions are further confirmed by H/D substitution experiment. -- Abstract: Size-selected IR-VUV spectroscopy is employed to detect vibrational characteristics in the region 2850 {approx} 3550 cm{sup -1} of neutral acetone and its clusters (CH{sub 3}COCH{sub 3}){sub n} (n = 1-4). Features around 3440 cm{sup -1} in the spectra of acetone monomer and its clusters are assigned to the carbonyl stretch (CO) overtone. These features red-shift from 3455 to 3433 cm{sup -1} as the size of the clusters increases from the monomer to the tetramer. Based on calculations, the experimental IR spectra in the C=O overtone region suggest that the dominant structures for the acetone trimer and tetramer should be cyclic in the supersonic expansion sample. This study also suggests that the carbonyl groups interact with the methyl groups in the acetone clusters. These weak interactions are further confirmed by the use of deuterium substitution.

  2. Application of LaserBreath-001 for breath acetone measurement in subjects with diabetes mellitus

    Science.gov (United States)

    Wang, Zhennan; Sun, Meixiu; Chen, Zhuying; Zhao, Xiaomeng; Li, Yingxin; Wang, Chuji

    2016-11-01

    Breath acetone is a promising biomarker of diabetes mellitus. With an integrated standalone, on-site cavity ringdown breath acetone analyzer, LaserBreath-001, we tested breath samples from 23 type 1 diabetic (T1D) patients, 312 type 2 diabetic (T2D) patients, 52 healthy subjects. In the cross-sectional studies, the obtained breath acetone concentrations were higher in the diabetic subjects compared with those in the control group. No correlation between breath acetone and simultaneous BG was observed in the T1D, T2D, and healthy subjects. A moderate positive correlation between the mean individual breath acetone concentrations and the mean individual BG levels was observed in the 20 T1D patients without ketoacidosis. In a longitudinal study, the breath acetone concentrations in a T1D patient with ketoacidosis decreased significantly and remained stable during the 5-day hospitalization. The results from a relatively large number of subjects tested indicate that an elevated mean breath acetone concentration exists in diabetic patients in general. Although many physiological parameters affect breath acetone concentrations, fast (diabetic screening and management under a specifically controlled condition.

  3. 77 FR 28266 - Acetone; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2012-05-14

    ... (LOAEL) from the toxicity studies are discussed in this unit. The toxicity data base for acetone includes... (approximately 3,086 mg/kg/day). Acetone is normally eliminated mainly by enzymatic metabolism (70- 80% of the...--as a key product of intermediary metabolism--can enter various pathways, e.g. gluconeogenesis or...

  4. Skin barrier disruption by acetone: observations in a hairless mouse skin model

    NARCIS (Netherlands)

    Rissmann, R.; Oudshoorn, M.H.M.; Hennink, W.E.; Ponec, M.; Bouwstra, J.A.

    2009-01-01

    To disrupt the barrier function of the skin, different in vivo methods have been established, e.g., by acetone wiping or tape-stripping. In this study, the acetone-induced barrier disruption of hairless mice was investigated in order to establish a reliable model to study beneficial, long-term effec

  5. Antibacterial Activities and Mechanism of Action of Acetone Extracts from Rabdosia rubescens

    Directory of Open Access Journals (Sweden)

    Li Ping Cheng

    2014-12-01

    Full Text Available The antibacterial activities and mechanism of action of acetone extracts from R. rubescens were reported in this paper. The results showed that 80% acetone extracts had both the highest contents of total phenolics and flavonoids. Acetone extracts showed better antibacterial activities against Gram-positive bacterial strains and there were no inhibitory effects found on tested Gram-negative bacteria. In addition, 80% acetone extracts from R. rubescens had relatively higher antibacterial activities with the lowest values of MIC and MBC at 2.5 mg/mL and 5 mg/mL against B. subtilis. The antibacterial mechanism of 80% acetone extracts against Bacillus subtilis might be described as disrupting cell wall, increasing cell membrane permeability, and finally leading to the leakage of cell constituents

  6. Characterization of transient species in laser photolysis of aromatic amino acids using acetone as photosensitizer

    Institute of Scientific and Technical Information of China (English)

    宋钦华; 徐业平; 俞书勤; 陈从香; 马兴孝; 王文锋; 姚思德; 林念芸

    1999-01-01

    The photochemical processes of aromatic amino acids were investigated in aqueous solution using acetone as photosensitizer by KrF (248 nm) laser flash photolysis. Laser-induced transient species were characterized according to kinetic analysis and quenching experiments. The intermediates recorded were assigned to the excited triplet state of tryptophan, the radicals of tryptophan and tyrosine. The excited triplet state of tryptophan produced via a triplet-triplet excitation transfer and the radicals arising from electron transfer reaction has been identified. Neither electron transfer nor energy transfer between triplet acetone and phenylalanine can occur in photolysis of phenylalanine aqueous solution which contains acetone. Furthermore, triplet acetone-induced radical transformation: Trp/N-Tyr→Trp-Tyr/O was observed directly in photolysis of dipeptide (Trp-Tyr) aqueous solution containing acetone, and the transformation resulting from intramolecular electron transfer was suggested.

  7. Structure and internal rotation dynamics of the acetone-neon complex studied by microwave spectroscopy

    Science.gov (United States)

    Gao, Jiao; Seifert, Nathan A.; Thomas, Javix; Xu, Yunjie; Jäger, Wolfgang

    2016-12-01

    The microwave spectra of the van der Waals complexes acetone-20Ne and acetone-22Ne were measured using a cavity-based supersonic jet Fourier-transform microwave spectrometer in the region from 5 to 18 GHz. For these two isotopologues, both c- and weaker a-type transitions were observed. The transitions are split into multiplets due to the internal rotation of the two methyl groups in acetone. Initial electronic structure calculations were performed at the MP2/6-311++g (2d, p) level of theory and the internal rotation barrier height of the methyl groups was calculated to be ∼2.8 kJ/mol. The ab initio rotational constants were the basis for the spectroscopic searches, but the multiplet structures and floppiness of the complex made the quantum number assignment very difficult. The assignment was finally achieved with the aid of constructing closed frequency loops and predicting internal rotation splittings using the XIAM internal rotation program. The acetone methyl group tunneling barrier height was determined experimentally to be 3.10(6) kJ mol-1 [259(5) cm-1] in the acetone-Ne complex, which is lower than in the acetone monomer but comparable to the acetone-Ar complex (Kang et al., 2002). Experimental data and high-level CCSD(T)/aug-cc-pVTZ calculations suggest that the Ne atom lies directly above the plane formed by the carbonyl group and the two carbon-carbon bonds, which is different than the slightly offset position found previously in the acetone-Ar complex. Additionally, ab initio calculations and Quantum Theory of Atoms in Molecules analyses were used to analyze the methyl internal rotation motions in acetone and acetone-Ne.

  8. Heat transfer performance of a pulsating heat pipe charged with acetone-based mixtures

    Science.gov (United States)

    Wang, Wenqing; Cui, Xiaoyu; Zhu, Yue

    2016-12-01

    Pulsating heat pipes (PHPs) are used as high efficiency heat exchangers, and the selection of working fluids in PHPs has a great impact on the heat transfer performance. This study investigates the thermal resistance characteristics of the PHP charged with acetone-based binary mixtures, where deionized water, methanol and ethanol were added to and mixed with acetone, respectively. The volume mixing ratios were 2:1, 4:1 and 7:1, and the heating power ranged from 10 to 100 W with filling ratios of 45, 55, 62 and 70%. At a low filling ratio (45%), the zeotropic characteristics of the binary mixtures have an influence on the heat transfer performance of the PHP. Adding water, which has a substantially different boiling point compared with that of acetone, can significantly improve the anti-dry-out ability inside the PHP. At a medium filling ratio (55%), the heat transfer performance of the PHP is affected by both phase transition characteristics and physical properties of working fluids. At high heating power, the thermal resistance of the PHP with acetone-water mixture is between that with pure acetone and pure water, whereas the thermal resistance of the PHP with acetone-methanol and acetone-ethanol mixtures at mixing ratios of 2:1 and 4:1 is less than that with the corresponding pure fluids. At high filling ratios (62 and 70%), the heat transfer performance of the PHP is mainly determined by the properties of working fluids that affects the flow resistance. Thus, the PHP with acetone-methanol and acetone-ethanol mixtures that have a lower flow resistance shows better heat transfer performance than that with acetone-water mixture.

  9. Vertical-cavity surface-emitting laser vapor sensor using swelling polymer reflection modulation

    DEFF Research Database (Denmark)

    Ansbæk, Thor; Nielsen, Claus Højgård; Dohn, Søren

    2012-01-01

    Vapor detection using a low-refractive index polymer for reflection modulation of the top mirror in a vertical-cavity surface-emitting laser (VCSEL) is demonstrated. The VCSEL sensor concept presents a simple method to detect the response of a sensor polymer in the presence of volatile organic co...... compounds. We model the physics as a change in the top mirror loss caused by swelling of the polymer upon absorbing the target volatile organic compound. Further we show how acetone vapors at 82 000 ppm concentration can change the polymer coated VCSEL output power by 20 mu W....

  10. Selective gas sensing for photonic crystal lasers

    DEFF Research Database (Denmark)

    Smith, Cameron; Christiansen, Mads Brøkner; Buss, Thomas;

    2011-01-01

    We facilitate photonic crystal lasers to sense gases via an additional swelling polymer film. We describe the transduction transfer function and experimentally demonstrate an enhanced ethanol vapor sensitivity over 15 dB with low humidity crosstalk....

  11. Remote sensing for gas plume monitoring using state-of-the-art infrared hyperspectral imaging

    Science.gov (United States)

    Hinnrichs, Michele

    1999-02-01

    Under contract to the US Air Force and Navy, Pacific Advanced Technology has developed a very sensitive hyperspectral imaging infrared camera that can perform remote imaging spectro-radiometry. One of the most exciting applications for this technology is in the remote monitoring of gas plume emissions. Pacific Advanced Technology (PAT) currently has the technology available to detect and identify chemical species in gas plumes using a small light weight infrared camera the size of a camcorder. Using this technology as a remote sensor can give advanced warning of hazardous chemical vapors undetectable by the human eye as well as monitor the species concentrations in a gas plume from smoke stack and fugitive leaks. Some of the gas plumes that have been measured and species detected using an IMSS imaging spectrometer are refinery smoke stacks plumes with emission of CO2, CO, SO2, NOx. Low concentration vapor unseen by the human eye that has been imaged and measured is acetone vapor evaporating at room temperature. The PAT hyperspectral imaging sensor is called 'Image Multi-spectral Sensing or IMSS.' The IMSS instrument uses defractive optic technology and exploits the chromatic aberrations of such lenses. Using diffractive optics for both imaging and dispersion allows for a very low cost light weight robust imaging spectrometer. PAT has developed imaging spectrometers that span the spectral range from the visible, midwave infrared (3 to 5 microns) and longwave infrared (8 to 12 microns) with this technology. This paper will present the imaging spectral data that we have collected on various targets with our hyperspectral imaging instruments as will also describe the IMSS approach to imaging spectroscopy.

  12. Highly sensitive room temperature organic vapor sensor based on polybenzoxazine-derived carbon aerogel thin film composite

    Energy Technology Data Exchange (ETDEWEB)

    Thubsuang, Uthen [Materials Science and Engineering, School of Engineering and Resources, Walailak University, Nakhon Si Thammarat 80160 (Thailand); Sukanan, Darunee [The Petroleum and Petrochemical College and the Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330 (Thailand); Sahasithiwat, Somboon [National Metal and Materials Technology Center, Thailand Science Park (TSP), Khlong Luang, Pathum Thani 12120 (Thailand); Wongkasemjit, Sujitra [The Petroleum and Petrochemical College and the Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330 (Thailand); Chaisuwan, Thanyalak, E-mail: thanyalak.c@chula.ac.th [The Petroleum and Petrochemical College and the Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330 (Thailand)

    2015-10-15

    Graphical abstract: - Highlights: • Activated carbon aerogel with high surface area can be prepared from polybenzoxazine. • Activated carbon aerogel enhances the adsorption capacity of gas sensor. • Organic vapors with very low concentration can be detected by the as-prepared sensor. • The as-prepared sensor shows impressive short exposure and recovery time. • The response to different organic vapors can be tailored by changing polymer matrix. - Abstract: Gas sensing composites were fabricated using polybenzoxazine-based activated carbon aerogel as a conductive filler. The activated carbon aerogel is a nano-porous material, which has high pore volume of 0.57 cm{sup 3}/g and surface area of 917 m{sup 2}/g. The activated carbon aerogel/polybutadiene composite displayed good response of 11.2 and 6.7 to toluene and n-hexane, respectively, compared to those of graphite/polybutadiene composite. The activated carbon aerogel/polybutadiene composite also showed high sensitivity of 3.09 × 10{sup 2} ppm{sup −1} to toluene. However, the sensitivity of activated carbon aerogel/polybutadiene composite drastically decreased to 1.99 ppm{sup −1} and zero when exposed to acetone and water, respectively. Contrarily, when polyvinyl alcohol was used as a matrix, the sensitivity was about 4.19 ppm{sup −1} to water. While the composite was found to be not sensitive to toluene. The activated carbon aerogel/polybutadiene composite also showed good recovery as the electrical resistance came back to the original value within minutes when exposed to nitrogen gas.

  13. 短脉冲激光作用下丙酮液池的温度场计算%Temperature Calculation in Acetone Pool Under Short Pulsed Laser - heated

    Institute of Scientific and Technical Information of China (English)

    金仁喜; 华顺芳; 刘登瀛; 张正芳

    2001-01-01

    采用短脉冲激光加热浸没在丙酮液体里的钥薄膜电阻,并结合数值模拟计算,研究了高温升率条件下丙酮液体温度场随时间的变化规律及汽泡行为,得到丙酮液池温度过界层的数量级大约为30~40μm。认为薄汽膜的形成和热边界层外移是激光脉冲过后很长一段时间内汽泡依然长大的主要原因,确定了铂薄膜电阻的激光反射损失。%Extremely small platinum film that is immersed in acetone pool is heated by short pulsed laser. Acetone temperature variations and its boiling bubble behavior are studied experimentally and by two -dimensional heat conduction numerical simulation. It shows that the thermal boundary layer in acetone is an order of 30~ 40μm, and the formation of vapor and thermal boundary layer being thicker are the main reasons that vapor bubble still grows up long after laser pulse shorts. Laser reflection loss by platinum film is calculated.

  14. Theory of supercompression of vapor bubbles and nanoscale thermonuclear fusion

    Science.gov (United States)

    Nigmatulin, Robert I.; Akhatov, Iskander Sh.; Topolnikov, Andrey S.; Bolotnova, Raisa Kh.; Vakhitova, Nailya K.; Lahey, Richard T.; Taleyarkhan, Rusi P.

    2005-10-01

    This paper provides the theoretical basis for energetic vapor bubble implosions induced by a standing acoustic wave. Its primary goal is to describe, explain, and demonstrate the plausibility of the experimental observations by Taleyarkhan et al. [Science 295, 1868 (2002); Phys. Rev. E 69, 036109 (2004)] of thermonuclear fusion for imploding cavitation bubbles in chilled deuterated acetone. A detailed description and analysis of these data, including a resolution of the criticisms that have been raised, together with some preliminary HYDRO code simulations, has been given by Nigmatulin et al. [Vestnik ANRB (Ufa, Russia) 4, 3 (2002); J. Power Energy 218-A, 345 (2004)] and Lahey et al. [Adv. Heat Transfer (to be published)]. In this paper a hydrodynamic shock (i.e., HYDRO) code model of the spherically symmetric motion for a vapor bubble in an acoustically forced liquid is presented. This model describes cavitation bubble cluster growth during the expansion period, followed by a violent implosion during the compression period of the acoustic cycle. There are two stages of the bubble dynamics process. The first, low Mach number stage, comprises almost all the time of the acoustic cycle. During this stage, the radial velocities are much less than the sound speeds in the vapor and liquid, the vapor pressure is very close to uniform, and the liquid is practically incompressible. This process is characterized by the inertia of the liquid, heat conduction, and the evaporation or condensation of the vapor. The second, very short, high Mach number stage is when the radial velocities are the same order, or higher, than the sound speeds in the vapor and liquid. In this stage high temperatures, pressures, and densities of the vapor and liquid take place. The model presented herein has realistic equations of state for the compressible liquid and vapor phases, and accounts for nonequilibrium evaporation/condensation kinetics at the liquid/vapor interface. There are interacting

  15. Experimental results of acetone hydrogenation on a heat exchanger type reactor for solar chemical heat pump; Solar chemical heat pump ni okeru acetone suisoka hanno netsu kaishu jikken

    Energy Technology Data Exchange (ETDEWEB)

    Takashima, T.; Doi, T.; Tanaka, T.; Ando, Y. [Electrotechnical Laboratory, Tsukuba (Japan); Miyahara, R.; Kamoshida, J. [Shibaura Institute of Technology, Tokyo (Japan)

    1996-10-27

    With the purpose of converting solar heat energy to industrial heat energy, an experiment of acetone hydrogenation was carried out using a heat exchanger type reactor that recovers heat generated by acetone hydrogenation, an exothermic reaction, and supplies it to an outside load. In the experiment, a pellet-like activated carbon-supported ruthenium catalyst was used for the acetone hydrogenation with hydrogen and acetone supplied to the catalyst layer at a space velocity of 400-1,200 or so. In the external pipe of the double-pipe type reactor, a heating medium oil was circulated in parallel with the flow of the reactant, with the heat of reaction recovered that was generated from the acetone hydrogenation. In this experiment, an 1wt%Ru/C catalyst and a 5wt%Ru/C catalyst were used so as to examine the effects of variation in the space velocity. As a result, from the viewpoint of recovering the heat of reaction, it was found desirable to increase the reaction speed by raising catalytic density and also to supply the reactant downstream inside the reaction pipe by increasing the space velocity. 1 ref., 6 figs., 1 tab.

  16. Acetone, butanol, and ethanol production from wastewater algae.

    Science.gov (United States)

    Ellis, Joshua T; Hengge, Neal N; Sims, Ronald C; Miller, Charles D

    2012-05-01

    Acetone, butanol, and ethanol (ABE) fermentation by Clostridium saccharoperbutylacetonicum N1-4 using wastewater algae biomass as a carbon source was demonstrated. Algae from the Logan City Wastewater Lagoon system grow naturally at high rates providing an abundant source of renewable algal biomass. Batch fermentations were performed with 10% algae as feedstock. Fermentation of acid/base pretreated algae produced 2.74 g/L of total ABE, as compared with 7.27 g/L from pretreated algae supplemented with 1% glucose. Additionally, 9.74 g/L of total ABE was produced when xylanase and cellulase enzymes were supplemented to the pretreated algae media. The 1% glucose supplement increased total ABE production approximately 160%, while supplementing with enzymes resulted in a 250% increase in total ABE production when compared to production from pretreated algae with no supplementation of extraneous sugar and enzymes. Additionally, supplementation of enzymes produced the highest total ABE production yield of 0.311 g/g and volumetric productivity of 0.102 g/Lh. The use of non-pretreated algae produced 0.73 g/L of total ABE. The ability to engineer novel methods to produce these high value products from an abundant and renewable feedstock such as algae could have significant implications in stimulating domestic energy economies.

  17. Photochromism and polarization spectroscopy of p-methyl(thiobenzoyl)acetone

    Energy Technology Data Exchange (ETDEWEB)

    Gorski, Alexander [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw (Poland); Posokhov, Yevgen [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw (Poland); Hansen, Bjarke K.V. [Department of Life Sciences and Chemistry, Roskilde University, P.O. Box 260, DK-4000, Roskilde (Denmark); Spanget-Larsen, Jens [Department of Life Sciences and Chemistry, Roskilde University, P.O. Box 260, DK-4000, Roskilde (Denmark); Jasny, Jan [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw (Poland); Duus, Fritz [Department of Life Sciences and Chemistry, Roskilde University, P.O. Box 260, DK-4000, Roskilde (Denmark); Hansen, Poul Erik [Department of Life Sciences and Chemistry, Roskilde University, P.O. Box 260, DK-4000, Roskilde (Denmark); Waluk, Jacek [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw (Poland)], E-mail: waluk@ichf.edu.pl

    2006-09-29

    Photochromism of p-methyl(thiobenzoyl)acetone (1) has been studied in argon and xenon cryogenic matrices. Application of linearly polarized light to induce the phototransformation resulted in partial alignment of both the initial structure and the photochromic product. Different orientations were achieved by using irradiation wavelengths corresponding to differently polarized electronic transitions. This was followed by measurements of linear dichroism (LD) in the IR region. The analysis of the IR spectra, combined with the results of DFT B3LYP/cc-pVDZ calculations enabled determining the structures of the most stable ground state species and of the photoproduct. Similarly to the recently reported cases of thioacetylacetone and monothiodibenzoylmethane, the initial structure of 1 corresponds to an intramolecularly hydrogen-bonded enol form, and the photochromic species to an 'open', nonchelated enethiolic form. Vibrational assignments have been made for both species, greatly helped by the analysis of the LD spectra. It is concluded that DFT calculations for 1 quite reliably predict not only vibrational frequencies and intensities, but also transition moment directions, in both IR and electronic spectra.

  18. Evaluation of Tribulus terrestris Linn (Zygophyllaceae) acetone extract for larvicidal and repellence activity against mosquito vectors.

    Science.gov (United States)

    Singh, S P; Raghavendra, K; Singh, R K; Mohanty, S S; Dash, A P

    2008-12-01

    Acetone extracts of leaves and seeds from the Tribulus terrestris (Zygophyllaceae) were tested against mature and immature different mosquito vectors under laboratory condition. The extract showed strong larvicidal, properties 100 per cent mortality in the 3rd-instar larvae was observed in the bioassays with An. culicifacies Giles species A, An. stephensi Liston, Culex quinquefasciatus Say and Aedes aegypti Linn, against 200 ppm of the leaf acetone extract and 100 ppm seed acetone extract. The LC50 values of leaf acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 117, 124, 168 and 185 ppm respectively. The LC50 values of seed acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 100, 72, 91 and 91 ppm respectively. It is confirmed from the LC50 values that the seed acetone extract of T. terrestris is more effective compared to leaf extracts. A significant (P<0.004) higher concentration of acetone extract leaf was required to kill equal number of larvae i.e. against acetone extract of seed. The seed acetone extract showed strong repellent activity against adults mosquitoes. Per cent protection obtained against Anopheles culicifacies species A 100% repellency in 1 h, 6 h; Anopheles stephensi 100% repellency in 0 h, 4 h, 6 h; and Culex quinquefasciatus 100% repellency in 0 h, 2 h, 4 h, at 10% concentration respectively. Against Deet- 2.5% An. culicifacies Giles species A has shown 100% repellency in 1 h, 2 h, 6 h, An. stephensi Liston 99% repellency in 4 h, and Culex quinquefasciatus Say has shown 100% repellency in 1 h, 2 h.

  19. North American acetone sources determined from tall tower measurements and inverse modeling

    OpenAIRE

    Hu,L; D. B. Millet; Kim, S Y; K. C. Wells; Griffis, T. J.; E. V. Fischer; Helmig, D.; J. Hueber; A. J. Curtis

    2013-01-01

    We apply a full year of continuous atmospheric acetone measurements from the University of Minnesota tall tower Trace Gas Observatory (KCMP tall tower; 244 m a.g.l.), with a 0.5° × 0.667° GEOS-Chem nested grid simulation to develop quantitative new constraints on seasonal acetone sources over North America. Biogenic acetone emissions in the model are computed based on the MEGANv2.1 inventory. An inverse analysis of the tall tower observations implies a 37% underestimate of e...

  20. Measurement of Solubilities of o-Phenylphenol in Petroleum Ether and DDP in Acetone + Water Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Li-sheng; LONG Bing-wen; XIONG You-qing; WU Jun-sheng; KANG Hui-bao

    2006-01-01

    [(6-oxide-6H-dibenze(c, e)(1, 2) oxaphosphorin-6-yl) methyl]-butanedioic acid (DDP) was prepared and characterized. Solubilities of o-phenylphenol(OPP) in petroleum ether and DDP in acetone + water solution were measured by a gravimetrical method. The solubility data of OPP were well correlated using Francis equation. For the solubility of DDP in acetone aqueous solution, it was found that at each fixed temperature there existed a maximum when the acetone mass fraction in the solvent reached a certain concentration. The experiment shows that the fraction is approximately 0.6. The solubility data would be helpful for their industrial crystallization process.

  1. Ozonolysis at vegetation surfaces. a source of acetone, 4-oxopentanal, 6-methyl-5-hepten-2-one, and geranyl acetone in the troposphere

    Science.gov (United States)

    Fruekilde, P.; Hjorth, J.; Jensen, N. R.; Kotzias, D.; Larsen, B.

    The present study gives a possible explanation for the ubiquitous occurrence of 6-methyl-5-hepten-2-one and acetone in ambient air and reports for the first time on a widespread occurrence of geranyl acetone and 4-oxopentanal. We have conducted a series of laboratory experiments in which it is demonstrated that significant amounts of geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO), 4-oxopentanal (4-OPA), and acetone are formed by the reaction of ozone with foliage of common vegetation in the Mediterranean area ( Quercus ilex>Citrus sinensis>Quercus suber>Quercus freinetto>Pinus pinea). In order to rule out biological formation, epicuticular waxes were extracted from the leaves, dispersed on glass wool and allowed to react with a flow of artificial air. Significant amounts of 6-MHO and 4-OPA were formed at ozone concentrations of 50-100 ppbv, but not at zero ozone. A number of terpenoids common in vegetation contain the structural element necessary for ozonolytic formation of 6-MHO. Two sesquiterpenes (nerolidol; farnesol), and a triterpene (squalene) selected as representative test compounds were demonstrated to be strong precursors for acetone, 4-OPA, and 6-MHO. Squalene was also a strong precursor for geranyl acetone. The atmospheric lifetime of geranyl acetone and 6-MHO is less than 1 h under typical conditions. For the present study, we have synthesized 4-OPA and investigated the kinetics of its gas-phase reaction with OH, NO 3, and O 3. A tropospheric lifetime longer than 17 h under typical conditions was calculated from the measured reaction rate constants, which explains the tropospheric occurrence of 4-OPA. It is concluded that future atmospheric chemistry investigations should included geranyl acetone, 6-MHO, and 4-OPA. In a separate experiment it was demonstrated that human skin lipid which contains squalene as a major component is a strong precursor for the four above-mentioned compounds plus nonanal and decanal. The accidental touching of material

  2. Soybean lecithin: acetone insoluble residue fractionation and their volatile components

    Directory of Open Access Journals (Sweden)

    Aly, Saadia M.

    2002-09-01

    Full Text Available The acetone insoluble residue was isolated from soybean lecithin. This residue was solvent fractionated resulted in four fractions, namely, acetic acid soluble, acetic acid insoluble, benzene phase and benzene insoluble phase. Concerning phospholipid constitution of these four fractions, it was found that the first fraction contains PC, PE and PI in percentages of 56.0, 21.6 and 19.0 respectively. The 2nd fraction makes 39 % PC and 60 % CER, besides some traces of PE and PI. The benzene phase is mainly all PC with some traces of PE. The last fraction is 80.6 % CER and 20 % PC. The fatty acid composition of these four fractions besides soluble in acetone, crude and degummed soybean oil and total phospholipids was recorded. Generally, it was found that the major saturated and unsaturated fatty acids were palmitic and linoleic. Volatile components of these samples except acetic acid insoluble were reported. Fourty nine compounds were separated. Thirty two components including aliphatic aldehydes, ketones, alcohols, esters and acids were identified. Aldehydes and ketones showed a changed through the seven samples. They increased by degumming.4,5-Dimethylelisoxazole had a strong lecithin like flavour, so it can be used as an indicator for the degumming process.2-Pentylfuran showed a significant decrease by degumming. Other compounds, such as esters and alcohols had no distinguish effect on the volatile products through process.El residuo insoluble en acetona fue aislado de la lecitina de soja. Este residuo fue fraccionado por solventes en cuatro fracciones: soluble en ácido acético, insoluble en ácido acético, fase benceno y fase insoluble en benceno. Concerniente a la constitución de los fosfolípidos de estas cuatro fracciones, se encontró que la primera fracción contiene PC, PE y PI en porcentajes del 56.0, 21.6 y 19.0 respectivamente. La segunda fracción tuvo 39 % PC y 60 % CER, junto a algunas trazas de PE y PI. La fase benceno est

  3. ZnO:Al Thin Film Gas Sensor for Detection of Ethanol Vapor

    Directory of Open Access Journals (Sweden)

    Min Hsiung Hon

    2006-10-01

    Full Text Available The ZnO:Al thin films were prepared by RF magnetron sputtering on Si substrateusing Pt as interdigitated electrodes. The structure was characterized by XRD and SEManalyses, and the ethanol vapor gas sensing as well as electrical properties have beeninvestigated and discussed. The gas sensing results show that the sensitivity for detecting400 ppm ethanol vapor was ~20 at an operating temperature of 250°C. The high sensitivity,fast recovery, and reliability suggest that ZnO:Al thin film prepared by RF magnetronsputtering can be used for ethanol vapor gas sensing.

  4. A visual and organic vapor sensitive photonic crystal sensor consisting of polymer-infiltrated SiO2 inverse opal.

    Science.gov (United States)

    Zhang, Yuqi; Qiu, Jianhua; Hu, Rongrong; Li, Pei; Gao, Loujun; Heng, Liping; Tang, Ben Zhong; Jiang, Lei

    2015-04-21

    A photonic crystal (PC) sensor that can selectively detect organic vapors through visual color changes has been proposed. The sensor was fabricated by infiltrating a tetraphenylethene polymer (TPEP) into the voids of SiO2 inverse opal photonic crystal. When the sensor was exposed to tetrahydrofuran or acetone vapor, a red shift of the stopband of more than 50 nm could be clearly observed; meanwhile, the film's color changed from violet to cyan. Subsequently, when exposed to air, the stopband underwent a blue shift and the color returned to violet. The reason for the observed change is that a reversible adsorption-desorption process occurs on alternate exposure of the sensor to organic vapor and air, due to the high specific surface area of the inverse opal macroporous structure and the high affinity of TPEP to tetrahydrofuran and acetone. The adsorption of vapor analyte can increase the PC's effective refractive index, which will induce the stopband red shift and the resulting color change according to Bragg's Law. The reversible adsorption-desorption of organic vapors varied the effective refractive index of the sensor repeatedly, causing the reversible stopband shift and color change, and providing a general method for the design of visual vapor sensors.

  5. Site Competition During Coadsorption of Acetone with Methanol and Water on TiO2(110)

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Mingmin; Henderson, Michael A.

    2011-08-02

    The competitive interaction between acetone and two solvent molecules (methanol and water) for surface sites on rutile TiO2(110) was studied using temperature programmed desorption (TPD). On a vacuum reduced TiO2(110) surface, which possessed ~5% oxygen vacancy sites, excess methanol displaced preadsorbed acetone molecules to weakly bound and physisorbed desorption states below 200 K, whereas acetone was stabilized to 250 K against displacement by methanol on an oxidized surface through formation of an acetone-diolate species. These behaviors of acetone differ from the competitive interactions between acetone and water in that acetone is less susceptible to displacement by water. Examination of acetone+methanol and acetone+water multilayer combinations shows that acetone is more compatible in water-ice films than in methanol-ice films, presumably because water has greater potential as a hydrogen-bond donor than does methanol. Acetone molecules displaced from the TiO2(110) surface by water are more likely to be retained in the near-surface region, having a greater opportunity to revisit the surface, than when methanol is used as a coadsorbate. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  6. Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

    Institute of Scientific and Technical Information of China (English)

    FANG,Yu; YIN,Yi-Qing; 等

    2002-01-01

    The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques.It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes.The aggregates are not solvolyzed in acetone,and do not take part n any chemical reactions either.It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone.The aggregation is reversible,and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.

  7. Concentration dependences of the physicochemical properties of a water-acetone system

    Science.gov (United States)

    Fedyaeva, O. A.; Poshelyuzhnaya, E. G.

    2017-01-01

    Concentration dependences of the UV spectrum, refractive index, specific electrical conductivity, boiling point, pH, surface tension, and heats of dissolution of a water-acetone system on the amount of acetone in the water are studied. It is found that the reversible protolytic interaction of the components occurs in all such solutions, resulting in the formation of hydroxyl and acetonium ions. It is shown that shifts of the equilibrium between the molecules and ions in the solution leads to extreme changes in their electrical properties. It is concluded that the formation of acetone solutions of water is accompanied by heat absorption, while the formation of aqueous solutions of acetone is accompanied by heat release.

  8. AMTEC vapor-vapor series connected cells

    Science.gov (United States)

    Underwood, Mark L.; Williams, Roger M.; Ryan, Margaret A.; Nakamura, Barbara J.; Oconnor, Dennis E.

    1995-08-01

    An alkali metal thermoelectric converter (AMTEC) having a plurality of cells structurally connected in series to form a septum dividing a plenum into two chambers, and electrically connected in series, is provided with porous metal anodes and porous metal cathodes in the cells. The cells may be planar or annular, and in either case a metal alkali vapor at a high temperature is provided to the plenum through one chamber on one side of the wall and returned to a vapor boiler after condensation at a chamber on the other side of the wall in the plenum. If the cells are annular, a heating core may be placed along the axis of the stacked cells. This arrangement of series-connected cells allows efficient generation of power at high voltage and low current.

  9. Electrocatalytic reduction of acetone in a proton-exchange-membrane reactor: a model reaction for the electrocatalytic reduction of biomass.

    Science.gov (United States)

    Green, Sara K; Tompsett, Geoffrey A; Kim, Hyung Ju; Bae Kim, Won; Huber, George W

    2012-12-01

    Acetone was electrocatalytically reduced to isopropanol in a proton-exchange-membrane (PEM) reactor on an unsupported platinum cathode. Protons needed for the reduction were produced on the unsupported Pt-Ru anode from either hydrogen gas or electrolysis of water. The current efficiency (the ratio of current contributing to the desired chemical reaction to the overall current) and reaction rate for acetone conversion increased with increasing temperature or applied voltage for the electrocatalytic acetone/water system. The reaction rate and current efficiency went through a maximum with respect to acetone concentration. The reaction rate for acetone conversion increased with increasing temperature for the electrocatalytic acetone/hydrogen system. Increasing the applied voltage for the electrocatalytic acetone/hydrogen system decreased the current efficiency due to production of hydrogen gas. Results from this study demonstrate the commercial feasibility of using PEM reactors to electrocatalytically reduce biomass-derived oxygenates into renewable fuels and chemicals.

  10. 萃取精馏分离丙酮-四氢呋喃的研究%Separation of acetone-tetrahydrofuran by extractive distillation

    Institute of Scientific and Technical Information of China (English)

    刘岩; 白鹏

    2012-01-01

    In order to separate acetone-tetrahydrofuran mixture, ethylbenzene as the solvent for separating acetone-tetrahydrofuran mixture by extractive distillation was chosen according to the basic selection rules. The simulation of vapor-liquid equilibrium using NRTL model for acetone-tetrahydrofuran system with and without ethylbenzene under atmospheric pressure and the vapor-liquid equilibrium experiment were performed. The simulation results agree well with the experimental data. The effectiveness of the solvent selected was also investigated by the batch extractive distillation experiments. The results show that ethylbenzene can eliminate the azeotropic point of acetone-tetrahydrofuran system. The batch distillation was carried out in a packed column of 40 theoretical plates. With the reflux ratio of 5 and the solvent mole ratio of 2. 5 : 1 ,the product mass fraction of acetone reaches 99. 34% , which reveals that the extractive distillation with ethylbenzene as solvent is useful in the separation of acetone-tetrahydrofuran. At last,the flow sheet of separating this azeotrope by batch and continual extractive distillation were simulated. The technological parameters obtained can provide the theoretical basis for further industrial application.%为了分离丙酮-四氢呋喃共沸混合物,研究了萃取精馏在丙酮-四氢呋喃物系中的应用.通过溶剂选择原理初选出乙苯作为萃取精馏分离此共沸物系的溶剂,同时采用NRTL模型对常压下丙酮-四氢呋喃物系和加入溶剂乙苯后的汽液平衡进行模拟和实验验证,模拟结果与实验数据吻合较好.然后进行了间歇萃取精馏分离此共沸物的实验研究来进一步考察所选萃取剂的效果.结果表明:乙苯能够消除丙酮-四氢呋喃共沸物系的共沸点,采用有40块理论板的填料塔,回流比为5,溶剂摩尔比为2.5∶1时塔顶可以得到质量分数为99.34%的丙酮产品,说明采用乙苯作萃取剂分离丙

  11. Expression of Clostridium acetobutylicum ATCC 824 Genes in Escherichia coli for Acetone Production and Acetate Detoxification

    OpenAIRE

    Bermejo, Lourdes L.; Welker, Neil E.; Papoutsakis, Eleftherios T.

    1998-01-01

    A synthetic acetone operon (ace4) composed of four Clostridium acetobutylicum ATCC 824 genes (adc, ctfAB, and thl, coding for the acetoacetate decarboxylase, coenzyme A transferase, and thiolase, respectively) under the control of the thl promoter was constructed and was introduced into Escherichia coli on vector pACT. Acetone production demonstrated that ace4 is expressed in E. coli and resulted in the reduction of acetic acid levels in the fermentation broth. Since different E. coli strains...

  12. Oscillatory bromate-oxalic acid-Ce-acetone-sulfuric acid reaction, in CSTR

    OpenAIRE

    Pereira,Janaina A. M.; Roberto B Faria

    2004-01-01

    Periodic oscillations were observed for the first time, in a CSTR, in the system bromate-oxalic acid-Ce(IV)-acetone-sulfuric acid, in a CSTR. A reaction between Ce(IV) and acetone, until now not described in the literature and occurring before the addition of the reagents to the reactor, was identified as a decisive factor for the appearing of the regular oscillations.

  13. Vapor Control Layer Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-09-08

    This information sheet describes the level of vapor control required on the interior side of framed walls with typical fibrous cavity insulation (fibreglass, rockwool, or cellulose, based on DOE climate zone of construction.

  14. Gasoline Vapor Recovery

    Science.gov (United States)

    1979-01-01

    Gasoline is volatile and some of it evaporates during storage, giving off hydrocarbon vapor. Formerly, the vapor was vented into the atmosphere but anti-pollution regulations have precluded that practice in many localities, so oil companies and storage terminals are installing systems to recover hydrocarbon vapor. Recovery provides an energy conservation bonus in that most of the vapor can be reconverted to gasoline. Two such recovery systems are shown in the accompanying photographs (mid-photo at right and in the foreground below). They are actually two models of the same system, although.configured differently because they are customized to users' needs. They were developed and are being manufactured by Edwards Engineering Corporation, Pompton Plains, New Jersey. NASA technological information proved useful in development of the equipment.

  15. Acetone and isopropanol in ruminal fluid and feces of lactating dairy cows.

    Science.gov (United States)

    Sato, Hiroshi; Shiogama, Yumiko

    2010-03-01

    Acetone and its metabolite isopropanol are produced by gut microbes as well as by the host's metabolism. To evaluate the production of acetone and isopropanol in alimentary tracts, a total of 80 pair-samples of feces and ruminal fluid were taken in lactating dairy cows that had been fed silage-containing diets. Acetone and isopropanol were analyzed, together with ethanol and volatile fatty acids (VFAs). Isopropanol was detected in 57 fecal and all the ruminal samples; however, the ruminal isopropanol and ethanol concentrations were distinctly lower than those in the feces. Acetone was detected in 13 fecal and 53 ruminal samples; however, there was no significant difference in acetone concentrations between the feces and the ruminal fluid. The group with higher fecal isopropanol concentration showed higher fecal proportions of acetate accompanied by low proportion of minor VFA, which consisted of isobutyrate and iso- and n-valerate. In the group with higher ruminal isopropanol concentration, ethanol concentration was higher; the ruminal VFA profiles showed only a negligible difference. Fecal and ruminal ethanol concentrations were not affected by feed ethanol. Thus, the colon showed an accelerated alcoholic fermentation compared with the rumen of dairy cows; however, acetone was present at higher frequency in the rumen than in the feces.

  16. A modified pathway for the production of acetone in Escherichia coli.

    Science.gov (United States)

    May, Antje; Fischer, Ralf-Jörg; Maria Thum, Simone; Schaffer, Steffen; Verseck, Stefan; Dürre, Peter; Bahl, Hubert

    2013-01-01

    A modified synthetic acetone operon was constructed. It consists of two genes from Clostridium acetobutylicum (thlA coding for thiolase and adc coding for acetoacetate decarboxylase) and one from Bacillus subtilis or Haemophilus influenzae (teII(srf) or ybgC, respectively, for thioesterase). Expression of this operon in Escherichia coli resulted in the production of acetone starting from the common metabolite acetyl-CoA via acetoacetyl-CoA and acetoacetate. The thioesterases do not need a CoA acceptor for acetoacetyl-CoA hydrolysis. Thus, in contrast to the classic acetone pathway of Clostridium acetobutylicum and related microorganisms which employ a CoA transferase, the new pathway is acetate independent. The genetic background of the host strains was crucial. Only E. coli strains HB101 and WL3 were able to produce acetone via the modified plasmid based pathway, up to 64mM and 42mM in 5-ml cultures, respectively. Using glucose fed-batch cultures the concentration could be increased up to 122mM acetone with HB101 carrying the recombinant plasmid pUC19ayt (thioesterase from H. influenzae). The formation of acetone led to a decreased acetate production by E. coli.

  17. Acetone production in solventogenic Clostridium species: new insights from non-enzymatic decarboxylation of acetoacetate.

    Science.gov (United States)

    Han, Bei; Gopalan, Venkat; Ezeji, Thaddeus Chukwuemeka

    2011-08-01

    Development of a butanologenic strain with high selectivity for butanol production is often proposed as a possible route for improving the economics of biobutanol production by solventogenic Clostridium species. The acetoacetate decarboxylase (aadc) gene encoding acetoacetate decarboxylase (AADC), which catalyzes the decarboxylation of acetoacetate into acetone and CO(2), was successfully disrupted by homologous recombination in solventogenic Clostridium beijerinckii NCIMB 8052 to generate an aadc ( - ) mutant. Our fermentation studies revealed that this mutant produces a maximum acetone concentration of 3 g/L (in P2 medium), a value comparable to that produced by wild-type C. beijerinckii 8052. Therefore, we postulated that AADC-catalyzed decarboxylation of acetoacetate is not the sole means for acetone generation. Our subsequent finding that non-enzymatic decarboxylation of acetoacetate in vitro, under conditions similar to in vivo acetone-butanol-ethanol (ABE) fermentation, produces 1.3 to 5.2 g/L acetone between pH 6.5 and 4 helps rationalize why various knock-out and knock-down strategies designed to disrupt aadc in solventogenic Clostridium species did not eliminate acetone production during ABE fermentation. Based on these results, we discuss alternatives to enhance selectivity for butanol production.

  18. Fermentation and genomic analysis of acetone-uncoupled butanol production by Clostridium tetanomorphum.

    Science.gov (United States)

    Gong, Fuyu; Bao, Guanhui; Zhao, Chunhua; Zhang, Yanping; Li, Yin; Dong, Hongjun

    2016-02-01

    In typical acetone-butanol-ethanol (ABE) fermentation, acetone is the main by-product (50 % of butanol mass) of butanol production, resulting in a low yield of butanol. It is known that some Clostridium tetanomorphum strains are able to produce butanol without acetone in nature. Here, we described that C. tetanomorphum strain DSM665 can produce 4.16 g/L butanol and 4.98 g/L ethanol at pH 6.0, and 9.81 g/L butanol and 1.01 g/L ethanol when adding 1 mM methyl viologen. Butyrate and acetate could be reassimilated and no acetone was produced. Further analysis indicated that the activity of the acetate/butyrate:acetoacetyl-CoA transferase responsible for acetone production is lost in C. tetanomorphum DSM665. The genome of C. tetanomorphum DSM665 was sequenced and deposited in DDBJ, EMBL, and GenBank under the accession no. APJS00000000. Sequence analysis indicated that there are no typical genes (ctfA/B and adc) that are typically parts of an acetone synthesis pathway in C. tetanomorphum DSM665. This work provides new insights in the mechanism of clostridial butanol production and should prove useful for the design of a high-butanol-producing strain.

  19. Lipid peroxidation and antioxidant system in rats acutely treated with acetone.

    Science.gov (United States)

    Mathias, M G; Almeida, B B de; Bueno, J E; Portari, G V; Jordao, A A

    2010-06-01

    Cascades of metabolic changes leading to acetone production are induced in states of energy catabolism such as starvation or the use of a ketogenic diet. The reduced capacity for cell detoxification or the increased generation of free radicals is responsible for the toxic effect of acetone. The objective of the present study was to determine the effects of acute treatment (AT) with acetone on the oxidative and metabolic status of rats. The AT group (n=16) was treated by gavage with a single administration of 7.0 g acetone/kg body weight at a concentration of 25% (m/v). Eight rats were euthanized 6 h later (AT6) and eight 24 h later (AT24). Acetone levels were determined in blood and urine and oxidative parameters were analyzed by determining thiobarbituric acid reactive species (TBARS, indicators of lipid peroxidation) and reduced glutathione (GSH) and vitamin E as antioxidant parameters. Serum glucose, blood cholesterol and triglycerieds and hepatic fat were also determined. The results indicated a significant difference in the hepatic oxidative parameters, serum glucose and in plasma triglycerides between the groups. Thus, we conclude that the administration of acute acetone doses can promote changes in some biochemical parameters and in the hepatic oxidative profile.

  20. Structural properties and gas sensing behavior of sol-gel grown nanostructured zinc oxide

    Science.gov (United States)

    Rajyaguru, Bhargav; Gadani, Keval; Rathod, K. N.; Solanki, Sapana; Kansara, S. B.; Pandya, D. D.; Shah, N. A.; Solanki, P. S.

    2016-05-01

    In this communication, we report the results of the studies on structural properties and gas sensing behavior of nanostructured ZnO grown using acetone precursor based modified sol-gel technique. Final product of ZnO was sintered at different temperatures to vary the crystallite size while their structural properties have been studied using X-ray diffraction (XRD) measurement performed at room temperature. XRD results suggest the single phasic nature of all the samples and crystallite size increases from 11.53 to 20.96nm with increase in sintering temperature. Gas sensing behavior has been studied for acetone gas which indicates that lower sintered samples are more capable to sense the acetone gas and related mechanism has been discussed in the light of crystallite size, crystal boundary density, defect mechanism and possible chemical reaction between gas traces and various oxygen species.

  1. Structural and micro structural studies of PbO-doped SnO2 sensor for detection of methanol,propanol and acetone

    Institute of Scientific and Technical Information of China (English)

    J.K.Srivastava; Preeti Pandey; V.N.Mishra; R.Dwivedi

    2011-01-01

    In the present work the structural information of PbO-doped SnO2 thick film sensor has been investigated with X-ray diffractometer(XRD)and scanning electron microscope(SEM).Initially,SnO2 powder was derived using sol-gel process and was subsequently doped with PbO and ground up to nanosized particles.A suitable gas sensor structure was fabricated on 1"× 1"alumina substrate using thick film technology.The necessary paste for screen printing was also developed.SEM results showed sol-gel derived powder gets more agglomerated in the thick film form.The sensitivity of the sensor has been investigated at different temperatures(150℃-350℃)upon exposure to methanol,propanol and acetone,yielding a maximum at 250℃ for acetone with 1 wt% PbO-doping while at 350℃ for propanol with 3 wt% PbO-doping of the sensor.The reduction of particle size to nanometers(validated through XRD)leads to a dramatic improvement in sensitivity of sensors for the chosen organic vapors.The results also correlate well with the microstructural properties of the material and the dopant.

  2. Determination of residual acetone and acetone related impurities in drug product intermediates prepared as Spray Dried Dispersions (SDD) using gas chromatography with headspace autosampling (GCHS).

    Science.gov (United States)

    Quirk, Emma; Doggett, Adrian; Bretnall, Alison

    2014-08-05

    Spray Dried Dispersions (SDD) are uniform mixtures of a specific ratio of amorphous active pharmaceutical ingredient (API) and polymer prepared via a spray drying process. Volatile solvents are employed during spray drying to facilitate the formation of the SDD material. Following manufacture, analytical methodology is required to determine residual levels of the spray drying solvent and its associated impurities. Due to the high level of polymer in the SDD samples, direct liquid injection with Gas Chromatography (GC) is not a viable option for analysis. This work describes the development and validation of an analytical approach to determine residual levels of acetone and acetone related impurities, mesityl oxide (MO) and diacetone alcohol (DAA), in drug product intermediates prepared as SDDs using GC with headspace (HS) autosampling. The method development for these analytes presented a number of analytical challenges which had to be overcome before the levels of the volatiles of interest could be accurately quantified. GCHS could be used after two critical factors were implemented; (1) calculation and application of conversion factors to 'correct' for the reactions occurring between acetone, MO and DAA during generation of the headspace volume for analysis, and the addition of an equivalent amount of polymer into all reference solutions used for quantitation to ensure comparability between the headspace volumes generated for both samples and external standards. This work describes the method development and optimisation of the standard preparation, the headspace autosampler operating parameters and the chromatographic conditions, together with a summary of the validation of the methodology. The approach has been demonstrated to be robust and suitable to accurately determine levels of acetone, MO and DAA in SDD materials over the linear concentration range 0.008-0.4μL/mL, with minimum quantitation limits of 20ppm for acetone and MO, and 80ppm for DAA.

  3. Covalent binding of acetone to aminophospholipids in vitro and in vivo.

    Science.gov (United States)

    Kuksis, Arnis; Ravandi, Amir; Schneider, Michael

    2005-06-01

    We have determined the ions characteristic of acetone adducts of reference aminophospholipids and have used them as markers for identification of acetone adducts of aminophospholipids in commercial lecithin, acetone extracts of tissue lipids, and in plasma and red blood cells of diabetic subjects. The acetonation products were determined by normal-phase high-performance liquid chromatography (HPLC) with on-line electrospray-mass spectrometry, and electrospray/collision-induced dissociation in the negative ion mode. The major acetone complexes of PtdEtn and PtdSer were identified as the diacetone derivatives [PtdEtn+116-H2O]- and [PtdSer+116-H2O]-, respectively, although ions corresponding to monoacetone [PtdEtn+58-H2O]- and doubly dehydrated diacetone adducts [PtdSer+116-2 x 18]- were also observed. Upon increase of the capillary exit voltage (CapEx) from -160 to -300 V, new ions appeared with the original retention time but with 58 masses (one acetone molecule) lower than the mass of the parent compounds, along with fragment ions corresponding to lysoGPE+40 and free fatty acids. Scanning of chloroform/methanol extracts of red blood cell lipids of two of five diabetic subjects examined yielded elevated levels (in relation to nondiabetic subjects) for ions corresponding to the diacetone adducts [M+98]- of the major molecular species of PtdEtn and PtdSer. Because of possible overlap with major molecular species of PtdIns, the identification of the acetonated PtdSer in diabetic blood requires further confirmation.

  4. Vapor pressures and enthalpies of vaporization of azides

    Energy Technology Data Exchange (ETDEWEB)

    Verevkin, Sergey P., E-mail: sergey.verevkin@uni-rostock.de [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059 Rostock (Germany); Emel' yanenko, Vladimir N. [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059 Rostock (Germany); Algarra, Manuel [Centro de Geologia do Porto, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Manuel Lopez-Romero, J. [Department of Organic Chemistry, University of Malaga. Campus de Teatinos s/n, 29071 Malaga (Spain); Aguiar, Fabio; Enrique Rodriguez-Borges, J.; Esteves da Silva, Joaquim C.G. [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2011-11-15

    Highlights: > We prepared and measured vapor pressures and vaporization enthalpies of 7 azides. > We examined consistency of new and available in the literature data. > Data for geminal azides and azido-alkanes selected for thermochemical calculations. - Abstract: Vapor pressures of some azides have been determined by the transpiration method. The molar enthalpies of vaporization {Delta}{sub l}{sup g}H{sub m} of these compounds were derived from the temperature dependencies of vapor pressures. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of similarly structured compounds.

  5. Potentiometric detection of chemical vapors using molecularly imprinted polymers as receptors

    Science.gov (United States)

    Liang, Rongning; Chen, Lusi; Qin, Wei

    2015-07-01

    Ion-selective electrode (ISE) based potentiometric gas sensors have shown to be promising analytical tools for detection of chemical vapors. However, such sensors are only capable of detecting those vapors which can be converted into ionic species in solution. This paper describes for the first time a polymer membrane ISE based potentiometric sensing system for sensitive and selective determination of neutral vapors in the gas phase. A molecularly imprinted polymer (MIP) is incorporated into the ISE membrane and used as the receptor for selective adsorption of the analyte vapor from the gas phase into the sensing membrane phase. An indicator ion with a structure similar to that of the vapor molecule is employed to indicate the change in the MIP binding sites in the membrane induced by the molecular recognition of the vapor. The toluene vapor is used as a model and benzoic acid is chosen as its indicator. Coupled to an apparatus manifold for preparation of vapor samples, the proposed ISE can be utilized to determine volatile toluene in the gas phase and allows potentiometric detection down to parts per million levels. This work demonstrates the possibility of developing a general sensing principle for detection of neutral vapors using ISEs.

  6. Hydrogen-bond acid group functionalized mesoporous-silica KIT-5 as sensing material to detect trace level organophosphorus vapor%氢键酸性基团功能化介孔敏感材料检测痕量有机磷气体

    Institute of Scientific and Technical Information of China (English)

    郭拴宝; 程振兴

    2015-01-01

    以3-碘基丙基三甲氧基硅烷为媒介,将具有氢键酸性化合物2,2-双(4-羟基苯基)六氟丙烷(BH-PHFP)嫁接到具有3D 介孔结构和高比表面积的KIT-5介孔材料上,得到有机磷检测敏感材料。利用TEM、HR-SEM、傅立叶红外光谱、N2吸附脱附等温曲线和热重分析对材料进行了表征,并与石英晶体微天平(QCM)结合构建质量敏感型气体传感器,可实现了对有机磷气体的痕量检测,该传感器且具有灵敏度高、重复性好和选择性高的优点。%The hydrogen-bond acid compound 2,2-bis (4-hydroxyphenyl)-hexafluoropropane (BHPHFP)has been used as a sensing group progressively grafted on the mesoporous-silica KIT-5 via chemical coupling reac-tion by 3-iodopropyl trimethoxysilane.Furthermore,it has been successfully characterized by transmission elec-tron microscopy (TEM),high resolution scanning electron microscopy (HR-SEM),Flourier transform infrared (FT-IR),N2 sorption isotherms and thermogravimetry analysis (TGA)curves.Then taking the quartz crystal microbalance sensor (QCM)as platform to form the organophosphorus vapor detection sensor,the QCM sensor obtains a higher sensitivity,repeatability and selectivity to detect the ppb-level concentration of organophospho-rus vapor.

  7. Evaluation of COSHH essentials: methylene chloride, isopropanol, and acetone exposures in a small printing plant.

    Science.gov (United States)

    Lee, Eun Gyung; Harper, Martin; Bowen, Russell B; Slaven, James

    2009-07-01

    The current study evaluated the Control of Substances Hazardous to Health (COSHH) Essentials model for short-term task-based exposures and full-shift exposures using measured concentrations of three volatile organic chemicals at a small printing plant. A total of 188 exposure measurements of isopropanol and 187 measurements of acetone were collected and each measurement took approximately 60 min. Historically, collected time-weighted average concentrations (seven results) were evaluated for methylene chloride. The COSHH Essentials model recommended general ventilation control for both isopropanol and acetone. There was good agreement between the task-based exposure measurements and the COSHH Essentials predicted exposure range (PER) for cleaning and print preparation with isopropanol and for cleaning with acetone. For the other tasks and for full-shift exposures, agreement between the exposure measurements and the PER was either moderate or poor. However, for both isopropanol and acetone, our findings suggested that the COSHH Essentials model worked reasonably well because the probabilities of short-term exposure measurements exceeding short-term occupational exposure limits (OELs) or full-shift exposures exceeding the corresponding full-shift OELs were <0.05 under the recommended control strategy. For methylene chloride, the COSHH Essentials recommended containment control but a follow-up study was not able to be performed because it had already been replaced with a less hazardous substance (acetone). This was considered a more acceptable alternative to increasing the level of control.

  8. Efficient acetone-butanol-ethanol production by Clostridium beijerinckii from sugar beet pulp.

    Science.gov (United States)

    Bellido, Carolina; Infante, Celia; Coca, Mónica; González-Benito, Gerardo; Lucas, Susana; García-Cubero, María Teresa

    2015-08-01

    Sugar beet pulp (SBP) has been investigated as a promising feedstock for ABE fermentation by Clostridium beijerinckii. Although lignin content in SBP is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. Autohydrolysis at pH 4 has been selected as the best pretreatment for SBP in terms of sugars release and acetone and butanol production. The best overall sugars release yields from raw SBP ranged from 66.2% to 70.6% for this pretreatment. The highest ABE yield achieved was 0.4g/g (5.1g/L of acetone and 6.6g/L butanol) and 143.2g ABE/kg SBP (62.3g acetone and 80.9g butanol) were obtained when pretreated SBP was enzymatically hydrolyzed at 7.5% (w/w) solid loading. Higher solid loadings (10%) offered higher acetone and butanol titers (5.8g/L of acetone and 7.8g/L butanol). All the experiments were carried out under not-controlling pH conditions reaching about 5.3 in the final samples.

  9. Thermodynamic Properties of the Azeotropic Mixture of Acetone, Cyclohexane and Methanol

    Institute of Scientific and Technical Information of China (English)

    WANG Xiu-Rong; NAN Zhao-Dong; TAN Zhi-Cheng

    2006-01-01

    Molar heat capacities of the pure samples of acetone, methanol and the azeotropic mixture composed of acetone,cyclohexane and methanol were measured by an adiabatic calorimeter from 78 to 320 K. The solid-solid and solid-liquid phase transitions of the pure samples and the mixture were determined based on the curve of the heat capacity with respect to temperature. The phase transitions took place at (126.16±0.68) and (178.96±1.47) K for the sample of acetone, (157.79±0.95) and (175.93±0.95) K for methanol, which were corresponding to the solid-solid and the solid-liquid phase transitions of the acetone and the methanol, respectively. And the phase transitions occurred in the temperature ranges of 120 to 190 K and 278 to 280 K corresponding to the solid-solid and the solid-liquid phase transitions of mixture of acetone, cyclohexane and methanol, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature of 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.

  10. Influence of acetone on nanostructure and electrochemical properties of interfacial synthesized polyaniline nanofibers

    Institute of Scientific and Technical Information of China (English)

    Jianyun Zhao; Zongyi Qin; Tao Li; Zhuozhan Li; Zhe Zhou; Meifang Zhu

    2015-01-01

    The growth of polyaniline (PANI) nanofibers through interfacial polymerization can be well controlled by adding a small amount of acetone in the water/chloroform system. It was found that the polymerization rate became slower in the presence of acetone, yielding PANI nanofibers with larger aspect ratios. The influences of the acetone addition on the morphology, microstructure and properties of as-prepared PANI nanofibers were studied by scanning electron microscope (FE-SEM), ultraviolet–visible spectra (UV–vis), Fourier transform infrared (FT-IR) and Raman spectroscopy, X-ray diffraction (XRD), thermogravity analysis (TGA), and electrical and electrochemical measurements. The experimental results showed that PANI nanofibers prepared by using ammonium persulfate (APS) as an oxidant with acetone exhibited slower growth, the larger ratio of length to diameter, and higher crystallinity (2θ¼ 61, 191, 261) than that without acetone, meanwhile remained larger yield of 11.23% and higher conductivity 1.8 ? 10 ? 2 S/cm compared with that obtained by replacing APS with FeCl3. More importantly, these PANI nanofibers exhibited better electrochemical behaviors, which benefitted from their high crystallinity and good conductivity.

  11. Biofiltration of mixtures of gas-phase styrene and acetone with the fungus Sporothrix variecibatus

    Energy Technology Data Exchange (ETDEWEB)

    Rene, Eldon R.; Spackova, Radka; Veiga, Maria C. [University of La Coruna, Dpt. of Chemical Engineering, Campus da Zapateira, Rua da Fraga, 10, 15008 La Coruna (Spain); Kennes, Christian, E-mail: kennes@udc.es [University of La Coruna, Dpt. of Chemical Engineering, Campus da Zapateira, Rua da Fraga, 10, 15008 La Coruna (Spain)

    2010-12-15

    The biodegradation performance of a biofilter, inoculated with the fungus Sporothrix variecibatus, to treat gas-phase styrene and acetone mixtures under steady-state and transient conditions was evaluated. Experiments were carried out by varying the gas-flow rates (0.05-0.4 m{sup 3} h{sup -1}), leading to empty bed residence times as low as 17.1 s, and by changing the concentrations of gas-phase styrene (0.01-6.3 g m{sup -3}) and acetone (0.01-8.9 g m{sup -3}). The total elimination capacities were as high as 360 g m{sup -3} h{sup -1}, with nearly 97.5% removal of styrene and 75.6% for acetone. The biodegradation of acetone was inhibited by the presence of styrene, while styrene removal was affected only slightly by the presence of acetone. During transient-state experiments, increasing the overall pollutant load by almost 3-fold, i.e., from 220 to 600 g m{sup -3} h{sup -1}, resulted in a sudden drop of removal efficiency (>90-70%), but still high elimination capacities were maintained. Periodic microscopic observations revealed that the originally inoculated Sporothrix sp. remained present in the reactor and actively dominant in the biofilm.

  12. Application of finite inverse gas chromatography in hypromellose acetate succinate-water-acetone systems.

    Science.gov (United States)

    Chiu, Sheng-Wei; Sturm, Derek R; Moser, Justin D; Danner, Ronald P

    2016-09-30

    A modification of a GC was developed to investigate both infinitely dilute and finite concentrations of solvents in polymers. Thermodynamic properties of hypromellose acetate succinate (HPMCAS-L)-acetone-water systems are important for the optimization of spray-drying processes used in pharmaceutical manufacturing of solid dispersion formulations. These properties, at temperatures below the glass transition temperature, were investigated using capillary column inverse gas chromatography (CCIGC). Water was much less soluble in the HPMCAS-L than acetone. Experiments were also conducted at infinitely dilute concentrations of one of the solvents in HPMCAS-L that was already saturated with the other solvent. Overall the partitioning of the water was not significantly affected by the presence of either water or acetone in the polymer. The acetone partition coefficient decreased as either acetone or water was added to the HPMCAS-L. A representation of the HPMCAS-L structure in terms of UNIFAC groups has been developed. With these groups, the UNIFAC-vdw-FV model did a reasonable job of predicting the phase equilibria in the binary and ternary systems. The Flory-Huggins correlation with fitted interaction parameters represented the data well.

  13. Influence of acetone on nanostructure and electrochemical properties of interfacial synthesized polyaniline nanofibers

    Directory of Open Access Journals (Sweden)

    Jianyun Zhao

    2015-08-01

    Full Text Available The growth of polyaniline (PANI nanofibers through interfacial polymerization can be well controlled by adding a small amount of acetone in the water/chloroform system. It was found that the polymerization rate became slower in the presence of acetone, yielding PANI nanofibers with larger aspect ratios. The influences of the acetone addition on the morphology, microstructure and properties of as-prepared PANI nanofibers were studied by scanning electron microscope (FE-SEM, ultraviolet–visible spectra (UV–vis, Fourier transform infrared (FT-IR and Raman spectroscopy, X-ray diffraction (XRD, thermogravity analysis (TGA, and electrical and electrochemical measurements. The experimental results showed that PANI nanofibers prepared by using ammonium persulfate (APS as an oxidant with acetone exhibited slower growth, the larger ratio of length to diameter, and higher crystallinity (2θ=6°, 19°, 26° than that without acetone, meanwhile remained larger yield of 11.23% and higher conductivity 1.8×10−2 S/cm compared with that obtained by replacing APS with FeCl3. More importantly, these PANI nanofibers exhibited better electrochemical behaviors, which benefitted from their high crystallinity and good conductivity.

  14. Polymer-Silicon Flexible Structures for Fast Chemical Vapor Detection

    Science.gov (United States)

    2007-01-01

    Engineering and School of Polymer, Textile and Fiber Engineering Georgia Institute of Technology Atlanta, GA 30332 (USA) E-mail: vladimir@mse.gatech.edu Dr...induce differential stress in a bimaterial cantilever for vapor sensing.[40] However, these coatings, amongst others (such as spin-coating, and inkjet

  15. 浅议丙酮肟在引进分厂锅炉给水系统中的应用%Application of acetone oxime in the boiler feed system in Injin Natural Gas Purification Plant

    Institute of Scientific and Technical Information of China (English)

    唐浠; 瞿杨; 蒋宇; 吴高亮; 秦婧

    2014-01-01

    Because of the reasons that hydrazine is flammable and explosive ,slowly reacts with oxygen ,toxic ,etc .,it is substituted by acetone oxime as deoxidant in Yinjin Branch of Chongqing Natural Gas Purification Plant General .Analysis results show that the acetone oxime has better deoxidization effect and lower toxicity than hydrazine ,and it does not affect the water vapor system ,so that it can protect the equipment and has inhibit effect .Further more ,acetone oxime can also reduce the production cost ,therefore ,it is more economical and practical .%重庆天然气净化总厂引进分厂原来在锅炉给水系统中一直使用联氨作为除氧剂,但由于联氨易燃易爆、除氧速度慢、具有毒性等原因,则采用丙酮肟代替联氨进行除氧。分析使用丙酮肟除氧后的数据,丙酮肟较联氨而言,除氧效果更好,毒性更低,不影响水汽系统,对设备有保护作用和缓蚀效果,并减少了生产成本,更具有经济效益和实用性。

  16. Designing and creating a modularized synthetic pathway in cyanobacterium Synechocystis enables production of acetone from carbon dioxide.

    Science.gov (United States)

    Zhou, Jie; Zhang, Haifeng; Zhang, Yanping; Li, Yin; Ma, Yanhe

    2012-07-01

    Ketones are a class of important organic compounds. As the simplest ketone, acetone is widely used as solvents or precursors for industrial chemicals. Presently, million tonnes of acetone is produced worldwide annually, from petrochemical processes. Here we report a biotechnological process that can produce acetone from CO(2), by designing and creating a modularized synthetic pathway in engineered cyanobacterium Synechocystis sp. PCC 6803. The engineered Synechocystis cells are able to produce acetone (36.0 mgl(-1) culture medium) using CO(2) as the sole carbon source, thus opens the gateway for biosynthesis of ketones from CO(2).

  17. Using acetone as solvent to study removal of anthracene in soil inhibits microbial activity and alters nitrogen dynamics.

    Science.gov (United States)

    Núñez, Edgar Vázquez; Rodríguez, Viviana; Gaytán, Alejandro García; Luna-Guido, Marco; Betancur-Galvis, Liliana A; Marsch, Rodolfo; Dendooven, Luc

    2009-08-01

    Acetone is often used as a carrier to contaminate soil with polycyclic aromatic hydrocarbons (PAHs) and then to study the factors that control their removal. Acetone is an organic solvent that might affect soil processes. An alkaline saline (Texcoco soil) and an agricultural soil (Acolman soil) were amended with or without acetone, nitrogen + phosphorus (NP), and contaminated with anthracene at 520 mg/kg soil while emissions of CO2 and N2O and concentrations of NH4+, NO2(-) and NO3(-) were monitored. The CO2 emission rate decreased greater than 10 times in the soils amended with acetone. Emission of N2O decreased 70 times in the Acolman soil amended with acetone and NP and 5 times in the Texcoco soil. The concentration of NH4+ decreased in the unamended Acolman and Texcoco soil but increased when acetone was added in the first and remained constant in the latter. Acetone inhibited the increase in the amount of NO3(-) in the Acolman soil but not in the Texcoco soil. It was found that microbial activity as evidenced by the emission of CO2, nitrification, and production of N2O were inhibited by acetone. The amount of acetone used as solvent should thus be kept to a minimum, but it can be assumed that its effect on soil processes will be temporary, as microorganisms are known to repopulate soil quickly.

  18. Increased blood concentration of isopropanol in ketotic dairy cows and isopropanol production from acetone in the rumen.

    Science.gov (United States)

    Sato, Hiroshi

    2009-08-01

    To evaluate acetone and isopropanol metabolism in bovine ketosis, the blood concentrations of isopropanol, acetone, plasma 3-hydroxybutyrate (3-HB) and other metabolites were analyzed in 12 healthy controls and 15 ketotic dairy cows including fatty liver and inferior prognosis after laparotomy for displaced abomasum. In ruminal fluid taken from 6 ketotic cows, ruminal isopropanol and acetone were also analyzed. Ketotic cows showed higher concentrations of isopropanol, acetone, 3-HB and nonesterified fatty acid, and higher activities of aspartate transaminase and gamma-glutamyl transferase than control cows. Blood samples had higher concentration of isopropanol accompanied by increased acetone. In the ketotic cows, acetone was detected not only in blood but also in ruminal fluid, while higher ruminal isopropanol did not necessarily accompany its elevation in the blood. Using 2 steers with rumen cannula, all ruminal content was emptied and then substituted with artificial saliva to evaluate the importance of ruminal microbes in isopropanol production. Under each condition of intact and emptied rumen, acetone was infused into the rumen and blood isopropanol was analyzed. The elevation in the blood isopropanol concentration after acetone infusion was markedly inhibited by the emptying. Here, increased blood concentrations of isopropanol and acetone were observed in ketotic cows, and the importance of ruminal microbes in isopropanol production was confirmed.

  19. (Ternary liquid + liquid) equilibria for (water + acetone + {alpha}-pinene, or {beta}-pinene, or limonene) mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoli [Department of Chemistry and Chemical Engineering, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Tamura, Kazuhiro, E-mail: tamura@t.kanazawa-u.ac.j [Department of Chemistry and Chemical Engineering, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)

    2010-11-15

    (Ternary liquid + liquid) equilibria (tie-lines) of (water + acetone + {alpha}-pinene) at T = (288.15, 298.15, and 308.15) K and (water + acetone + {beta}-pinene, or limonene) at T = 298.15 K have been measured. The experimental (ternary liquid + liquid) equilibrium data have been correlated successfully by the original UNIQUAC and modified UNIQUAC models. The modified UNIQUAC model reproduced accurately the experimental results for the (water + acetone + {alpha}-pinene) system at all the temperatures but fairly agreed with the experimental data for the (water + acetone + {beta}-pinene, or limonene) systems.

  20. Water vapor: An extraordinary terahertz wave source under optical excitation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Keith [Massachusetts Institute of Technology, PO Box 380792, Cambridge, MA 02238-0792 (United States); HydroElectron Ventures Inc., 1303 Greene Avenue Suite 102, Westmount, QC, H3Z 2A7 (Canada)], E-mail: kjohnson@mit.edu; Price-Gallagher, Matthew [HydroElectron Ventures Inc., 1303 Greene Avenue Suite 102, Westmount, QC, H3Z 2A7 (Canada); Mamer, Orval; Lesimple, Alain [Mass Spectroscopy Unit, 740 Dr. Penfield, Suite 5300, McGill University, Montreal, QC, H3A 1A4 (Canada); Fletcher, Clark [HydroElectron Ventures Inc., 1303 Greene Avenue Suite 102, Westmount, QC, H3Z 2A7 (Canada); Chen Yunqing; Lu Xiaofei; Yamaguchi, Masashi; Zhang, X.-C. [W.M. Keck Laboratory for Terahertz Science, Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

    2008-09-15

    In modern terahertz (THz) sensing and imaging spectroscopy, water is considered a nemesis to be avoided due to strong absorption in the THz frequency range. Here we report the first experimental demonstration and theoretical implications of using femtosecond laser pulses to generate intense broadband THz emission from water vapor. When we focused an intense laser pulse in water vapor contained in a gas cell or injected from a gas jet nozzle, an extraordinarily strong THz field from optically excited water vapor is observed. Water vapor has more than 50% greater THz generation efficiency than dry nitrogen. It had previously been assumed that the nonlinear generation of THz waves in this manner primarily involves a free-electron plasma, but we show that the molecular structure plays an essential role in the process. In particular, we found that THz wave generation from H{sub 2}O vapor is significantly stronger than that from D{sub 2}O vapor. Vibronic activities of water cluster ions, occurring naturally in water vapor, may possibly contribute to the observed isotope effect along with rovibrational contributions from the predominant monomers.

  1. Mn-doped ZnS quantum dots for the determination of acetone by phosphorescence attenuation

    Energy Technology Data Exchange (ETDEWEB)

    Sotelo-Gonzalez, Emma; Fernandez-Argueelles, Maria T. [Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julian Claveria 8, E-33006 Oviedo (Spain); Costa-Fernandez, Jose M., E-mail: jcostafe@uniovi.es [Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julian Claveria 8, E-33006 Oviedo (Spain); Sanz-Medel, Alfredo, E-mail: asm@uniovi.es [Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julian Claveria 8, E-33006 Oviedo (Spain)

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Colloidal Mn:ZnS QDs exhibiting intense and long-lasting phosphorescence were synthesized and exhaustively characterized. Black-Right-Pointing-Pointer Several experimental factors that influence classical phosphorescence do not modify the Mn:ZnS QDs phosphorescence emission. Black-Right-Pointing-Pointer Mn:ZnS QDs have been applied for phosphorescence-based acetone determination. Black-Right-Pointing-Pointer A mechanism has been proposed to explain acetone quenching effect on QDs phosphorescence. - Abstract: Quantum dot (QD) nanoparticles (NPs) are increasingly used as highly valuable fluorescent biomarkers and as sensitive (bio)chemical probes. Interestingly, if certain metal impurities are incorporated during the NPs synthesis, phosphorescent QDs with analytical potential can be obtained. We report here the synthesis of colloidal manganese-doped ZnS nanoparticles which have been surface-modified with L-cysteine that exhibit an intense room temperature phosphorescence (RTP) emission in aqueous media even in the presence of dissolved oxygen (i.e. sample deoxygenation is not needed). An exhaustive RTP photoluminescent and morphological characterization of the synthesized QDs and their potential for development of phosphorescent analytical methodologies is described. Application to analytical control of acetone ('model analyte' from the ketones family) in water and urine samples is carried out by measuring the QDs phosphorescence quenching rate. The observed results showed a high selectivity of Mn{sup 2+}-doped ZnS QDs towards acetone. The linear range of the developed methodology turned out to be at least up to 600 mg L{sup -1} with a detection limit (DL) for acetone dissolved in aqueous medium of 0.2 mg L{sup -1}. The developed methodology was finally applied for acetone determination in different spiked water and urine samples, and the recoveries fall in the range of 93-107%.

  2. Antioxidant effect of water and acetone extracts of Fucus vesiculosuson oxidative stability of skin care emulsions

    DEFF Research Database (Denmark)

    Poyato, Candelaria; Thomsen, Birgitte Raagaard; Hermund, Ditte Baun

    2017-01-01

    A water and an acetone extract of the Icelandic brown algae Fucus vesiculosus were evaluated as potential natural sources of antioxidant compounds in skin care emulsions. To assess their efficacy in inhibiting lipid oxidation caused by photo- or thermoxidation, they were stored in darkness and room...... temperature. High temperature also caused greater increments in the droplet size of the emulsions. The analysis of the tocopherol content, peroxide value and volatile compounds during the storage revealed that, whereas both water and acetone extracts showed (at 2 mg/g of emulsion) protective effect against...

  3. Promotion of dropwise condensation of ethyl alcohol, methyl alcohol, and acetone by polytetrafluoroethylene

    Science.gov (United States)

    Kirby, C. E.

    1972-01-01

    Coating condensing surfaces with thin layer of nonpolar Teflon results in dropwise condensation of polar organic vapor. Greater heat transfer coefficients are produced increasing effectiveness of condensing system. Investigation shows that vapors with strong dipole moment tend to condense dropwise.

  4. Fiber endface Fabry-Perot vapor microsensors fabricated by multiphoton polymerization technique

    Science.gov (United States)

    Melissinaki, Vasileia; Konidakis, Ioannis; Farsari, Maria; Pissadakis, Savros

    2015-03-01

    Three different designs of Fabry-Perot optical sensing microresonators fabricated by direct laser writing on the endface of a standard telecom fiber using a zirconium-silicon, organic-inorganic hybrid photosensitive material, are demonstrated. These endface optical fiber sensing probes are used for the detection of common organic alcohols and chlorinated solvents vapors. The devices operate in the spectral region lying between 1440 nm and 1660 nm, while the spectra recorded in reflection mode correlate to refractive index or absorption changes due to different vapors trapped inside the microcavities. A sensitivity of 1503nm/RIU, for a concentration of 4ppm ethanol vapors was succeeded. The microresonator sensing probe is explained in terms of standard physisorption and molecule packing mechanisms of organic vapors onto porous surfaces.

  5. Effects of acetone and fasting on cytochrome P-450 and xenobiotic metabolism in intact and hypophysectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Williams, M.T.; Simonet, L.

    1987-05-01

    Hypophysectomized and intact male and female rats were fasted for 24-48 hrs or given acetone (5ml/kg body weight) in order to evaluate the effects of these treatments on hepatic microsomal cytochrome P-450 and xenobiotic metabolism. Fasting and acetone treatment resulted in a significant increase (p < 0.05) in total P-450 in intact female rats. However, there was no significant changes in P-450 in microsomes from fasted or acetone-treated hypophysectomized rats. Fasting and acetone treatment resulted in significant increases in nitrosamine metabolism in intact rats. This effect was markedly reduced in the hypophysectomized rat. When intact male rats were fasted or treated with acetone there was a significant increase in P-450 in microsomes from acetone treated rats. Aryl hydrocarbon hydroxylase activity was significantly increased in both intact and hypophysectomized male and female rats treated with acetone. These results suggest that the pituitary gland or some product markedly influences acetone-stimulated nitrosamine metabolism.

  6. Neurotoxicity associated with occupational exposure to acetone, methyl ethyl ketone, and cyclohexanone.

    Science.gov (United States)

    Mitran, E; Callender, T; Orha, B; Dragnea, P; Botezatu, G

    1997-01-01

    The neurotoxic effects of acetone, methyl ethyl ketone (MEK), and cyclohexanone on Romanian workers and the impact of those effects on industry environmental standards have been controversial subjects. To scientifically substantiate the standards, a study was conducted on three groups of workers to determine the changes induced by ketone solvents on the central and peripheral nervous systems. Groups of exposed workers and matched controls were studied for each solvent: acetone, 71 exposed and 86 controls from a coin printing factory; MEK, 41 exposed and 63 controls from a cable factory; and cyclohexanone, 75 exposed and 85 controls from a furniture factory. The subjects' mean age was 36 years. The mean length of exposure was 14 years. Study participants completed a questionnaire, responded to questions about alcohol consumption, submitted to a clinical examination, submitted samples for identification of biological exposure markers, and underwent motor nerve conduction velocity and neurobehavioral tests. Results showed that workers exposed to acetone were most affected in terms of human performance and evidence of neurotoxicity, followed by workers exposed to MEK and workers exposed to cyclohexanone. On the basis of the results, it was proposed that the 6-hr permissible exposure limits for acetone, MEK, and cyclohexanone be reduced to less than 500, 200, and 150 mg/m3, respectively.

  7. Stable gold nanoparticles obtained in pure acetone by laser ablation with different wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Giorgetti, Emilia, E-mail: emilia.giorgetti@fi.isc.cnr.it [Consiglio Nazionale delle Ricerche, INSTM and Istituto dei Sistemi Complessi (Italy); Muniz-Miranda, Maurizio [Universita di Firenze, Dipartimento di Chimica ' Ugo Schiff' (Italy); Marsili, Paolo; Scarpellini, David [Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi (Italy); Giammanco, Francesco [University of Pisa, Department of Physics ' E. Fermi' (Italy)

    2012-01-15

    We prepared gold nanoparticles (NPs) by ps laser ablation in pure acetone and water with 532 and 1,064 nm wavelengths. The NPs obtained in pure acetone are stable for years and, depending on the fabrication conditions, they can be very small, quasi monodisperse and fluorescent. These properties are not lost when they are transferred from acetone to water. Post-irradiation tests of the colloids with 532 nm pulses, before and after phase transfer to water, and surface enhanced Raman spectroscopy (SERS), either on liquid and on dried samples, suggest that the stabilization mechanism in acetone is related to the light-induced formation on the gold surface of enolate which, in some cases, can undergo degradation with formation of amorphous carbon. Micro-SERS tests were also used to demonstrate that functionalization of the particles with 1,10-phenanthroline or adenine is possible after transfer to the water phase, which opens the way to the use of such structures for biological and medical applications, such as biocompatible fluorescent or Raman markers.

  8. Design of a solvent extraction process for PAH-contaminated sediments : The WAU-acetone process

    NARCIS (Netherlands)

    Rulkens, W.H.; Bruning, H.; Hasselt, H.J. van; Rienks, J.; Veen, H.J. van; Terlingen, J.P.M.

    1998-01-01

    Solvent extraction is one of the possibilities to clean-up polluted sediments. It is especially attractive when the sediment mainly consists of clay particles polluted with contaminants which are not, or not easily, biodegradable. Using acetone as extracting agent the extraction process has been inv

  9. Improvement of the cold flow characteristics of biodiesel containing dissolved polymer wastes using acetone

    Directory of Open Access Journals (Sweden)

    Pouya Mohammadi

    2014-03-01

    Full Text Available Due to the fast fossil fuel depletion and at the same time global warming phenomenon anticipated for the next coming years, the necessity of developing alternative fuels e.g. biofuels (i.e. bioethanol, biodiesel, biogas and etc. has turned into an important concern. Recently, the application of the bio-solvency properties of biodiesel for recycling waste polymers has been highlighted. However, the impact of polymer dissolution on cold flow characteristics of biodiesel was never investigated. The present study was set to explore the impact of different solvents in stabilizing biodiesel-polymer solution. Among them, acetone was proved to be the best fuel stabilizer. Subsequently, cold flow characteristic i.e. cloud point, of the biodiesel-polymer-acetone fuel was found to have improved (decreased due to the inclusion of acetone. Finally, flash point analysis of the fuel blends containing acetone was done to ensured high safety of the fuel blend by dramatically increasing the flash point values of biodiesel-polymer fuel blends.

  10. Production of acetone, butanol, and ethanol from biomass of the green seaweed Ulva lactuca

    NARCIS (Netherlands)

    Wal, van der H.; Sperber, B.L.H.M.; Houweling-Tan, G.B.N.; Bakker, R.R.C.; Brandenburg, W.A.; Lopez Contreras, Ana

    2013-01-01

    Green seaweed Ulva lactuca harvested from the North Sea near Zeeland (The Netherlands) was characterized as feedstock for acetone, ethanol and ethanol fermentation. Solubilization of over 90% of sugars was achieved by hot-water treatment followed by hydrolysis using commercial cellulases. A hydrolys

  11. Lignin depolymerisation in supercritical carbon dioxide/acetone/water fluid for the production of aromatic chemicals

    NARCIS (Netherlands)

    Gosselink, R.J.A.; Teunissen, W.; Dam, van J.E.G.; Jong, de E.; Gellerstedt, G.; Scott, E.L.; Sanders, J.P.M.

    2012-01-01

    Valorisation of lignin plays a key role in further development of lignocellulosic biorefinery processes the production of biofuels and bio-based materials. In the present study, organosolv hardwood and wheat straw lignins were converted in a supercritical fluid consisting of carbon dioxide/acetone/w

  12. Carbon and proton Overhauser DNP from MD simulations and ab initio calculations: TEMPOL in acetone.

    Science.gov (United States)

    Küçük, Sami Emre; Biktagirov, Timur; Sezer, Deniz

    2015-10-14

    A computational analysis of the Overhauser effect is reported for the proton, methyl carbon, and carbonyl carbon nuclei of liquid acetone doped with the nitroxide radical TEMPOL. A practical methodology for calculating the dynamic nuclear polarization (DNP) coupling factors by accounting for both dipole-dipole and Fermi-contact interactions is presented. The contribution to the dipolar spectral density function of nuclear spins that are not too far from TEMPOL is computed through classical molecular dynamics (MD) simulations, whereas the contribution of distant spins is included analytically. Fermi contacts are obtained by subjecting a few molecules from every MD snapshot to ab initio quantum mechanical calculations. Scalar interaction is found to be an essential part of the (13)C Overhauser DNP. While mostly detrimental to the carbonyl carbon of acetone it is predicted to result in large enhancements of the methyl carbon signal at magnetic fields of 9 T and beyond. In contrast, scalar coupling is shown to be negligible for the protons of acetone. The additional influence of proton polarization on the carbon DNP (three-spin effect) is also analyzed computationally. Its effect, however, is concluded to be practically insignificant for liquid acetone.

  13. Initial Dynamics of The Norrish Type I Reaction in Acetone: Probing Wave Packet Motion

    DEFF Research Database (Denmark)

    Brogaard, Rasmus Y.; Sølling, Theis I.; Møller, Klaus Braagaard

    2011-01-01

    The Norrish Type I reaction in the S1 (nπ*) state of acetone is a prototype case of ketone photochemistry. On the basis of results from time-resolved mass spectrometry (TRMS) and photoelectron spectroscopy (TRPES) experiments, it was recently suggested that after excitation the wave packet travels...

  14. Synthesis and Characterization of New Material——La/Zr/MMT Employed in Acetone Oxidation

    Institute of Scientific and Technical Information of China (English)

    FAN,Li-Ping; CHEN,Min; ZHANG,Yi-Gai; ZHOU,Ren-Xian; ZHENG,Xiao-Ming

    2007-01-01

    A new material of zirconium pillared montmorillonite added with lanthanum (denoted as La/Zr/MMT) was prepared for acetone oxidation. Surface properties of the catalysts were investigated by means of XRD, TEM,TG-DTA and BET methods. The XRD result indicated that the interlayer space of the montmorillonite was enlarged from 1.57 to 4.85 nm after the treatment with zirconium pillaring and the addition of lanthanum. N2 adsorption-desorption result showed that by the process of zirconium pillaring, the specific surface area of the sample was increased to 128.0 m2/g, which was two times almost as large as pure montmorillonite. Simultaneously, the thermal stability was also enhanced. The activity of the new material on the total oxidation of acetone was investigated, and the results indicated that the catalytic activity of the montmorillonite was greatly improved. Over the sample of La/Zr/MMT, the T98 of acetone was obtained at 350℃, while it needs 400℃ over the pure montmorillonite. After 0.1% Pd was supported on the sample of La/Zr/MMT, the T98 decreased from 350 to 280 ℃, indicating the montmorillonite is a promising material for the control of some types of the volatile organic compounds such as acetone.

  15. Breath acetone to monitor life style interventions in field conditions: an exploratory study.

    NARCIS (Netherlands)

    Samudrala, D.; Lammers, G.; Mandon, J.B.; Blanchet, Lionel; Schreuder, T.H.A.; Hopman, M.T.E.; Harren, F.J.M.; Tappy, L.; Cristescu, S.M.

    2014-01-01

    OBJECTIVE: To assess whether breath acetone concentration can be used to monitor the effects of a prolonged physical activity on whole body lipolysis and hepatic ketogenesis in field conditions. METHODS: Twenty-three non-diabetic, 11 type 1 diabetic, and 17 type 2 diabetic subjects provided breath a

  16. Thermal and Ablative Properties of Ipns and Composites of High Ortho Resole Resin and Difurfurylidene Acetone

    Directory of Open Access Journals (Sweden)

    Tariq S. NAJIM

    2008-12-01

    Full Text Available High ortho resole resin was prepared by condensation of phenol with excess of formaldehyde in the presence of magnesium oxide as catalyst. Reaction of furfuraldehyde with acetone in basic medium led to difurfurylidene acetone (DFA. Their interpenetrating polymer network (IPNS were obtained by the reaction of predetermined quantities of difurfurylidene acetone and high ortho resole using p-toluene sulphonic acid (PTSA as curing agent. The thermal behavior of the resins was studied using thermogravimetry (TG under ambient and nitrogen atmospheres over a temperature range of (25-1000 Cº. It was observed that the IPN of 20% DFA – 80% resole has higher thermal stability than that of resole alone and the decomposition temperature was higher by 80 Cº. This behavior was attributed to highly cross linked structure and thermally stable backbone of ploy difurfurylidene acetone due to formation of ladder structure.Impregnation of chopped fiber glass type (E with the polymeric solutions was used to prepare their composites, and the ablative properties were investigated according to ASTM E-285 –80. It was observed that the IPN of (DFA- resol perform better than the resole composite alone.

  17. High dilutions of acetone affect the Avena sativa growth in vitro

    Directory of Open Access Journals (Sweden)

    Kely Karina Belato

    2011-09-01

    Full Text Available Introduction: Acetone is an organic solvent with molecular structure CH3(COCH3, its endogenous production in the animal body is called ketosis. The production of this compound increases with the fat. Acetone influences the lipid membrane, altering its fluidity and lipid composition [1], causing cell damage and leakage and can cause cell death. The use of herbicides in organic farming is not accepted by the Brazilian legislation [2]. So the weed control becomes a problem for organic farmers. The aim of this study is to evaluate the herbicide potential of high dilutions of acetone on Avena sativa L. Materials and Methods: The preliminary tests were conducted at the Laboratory of Plant Physiology and Homeopathy, State University of Maringá (UEM. The seeds of Avena sativa are placed in Petri dishes. Fitty seeds were germinated and grown in Petri dishes containing 15ml of high dilution of acetone and maintained at 25°C ± 2 and 12h photoperiod. Acetone dilutions (6, 12, 18, 24 and 30cH were obtained according to the Brazilian Homeopathic Pharmacopoeia [3]. Were evaluated the shoot length (cm, total length (cm, fresh root (mg and total dry mass (mg. The plants growth was measured after 7 days. The control consisted of distilled water. The experiment evaluated 4 replicates of each treatment and the data were analyzed by ANOVA and means were compared by Scott-Knott test (P ≤ 0.05. Results and Discussion: Dilutions 6, 24 and 30 cH inhibited the growth of the shoot and total seedling of A. sativa. The root fresh weight was significantly reduced by 4 dilutions (6,12,24 and 30x, with no difference of 24x compared to the control. The total dry mass of plants of A. sativa was reduced in all the dilutions studied, showing an inhibitory effect on growth of seedlings subjected to treatment. Somehow, acetone diluited inhibited the growth and accumulation of biomass of these seedlings, suggesting an imbalance in metabolism

  18. Hydrogen bond dynamics and vibrational spectral diffusion in aqueous solution of acetone: A first principles molecular dynamics study

    Indian Academy of Sciences (India)

    Bhabani S Mallik; Amalendu Chandra

    2012-01-01

    We present an ab initio molecular dynamics study of vibrational spectral diffusion and hydrogen bond dynamics in aqueous solution of acetone at room temperature. It is found that the frequencies of OD bonds in the acetone hydration shell have a higher stretch frequency than those in the bulk water. Also, on average, the frequencies of hydration shell OD modes are found to increase with increase in the acetone-water hydrogen bond distance. The vibrational spectral diffusion of the hydration shell water molecules reveals three time scales: A short-time relaxation (∼80 fs) corresponding to the dynamics of intact acetone-water hydrogen bonds, a slower relaxation (∼1.3 ps) corresponding to the lifetime of acetone-water hydrogen bonds and another longer time constant (∼12 ps) corresponding to the escape dynamics of water from the solute hydration shell. The present first principles results are compared with those of available experiments and classical simulations.

  19. Toluene metabolism in isolated rat hepatocytes: effects of in vivo pretreatment with acetone and phenobarbital

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Kielland, A.; Ripel, A. (National Inst. of Forensic Toxicology, Oslo (Norway))

    1993-02-01

    Hepatocytes isolated from control, acetone- and phenobarbital-pretreated rats were used to study the metabolic conversion of toluene to benzyl alcohol, benzaldehyde, benzoic acid and hippuric acid at low (<100 [mu]M) and high (100-500 [mu]M) toluene concentrations. The baseline formation rates of toluene metabolites (benzyl alcohol, benzoic acid and hippuric acid) were 2.9[+-]1.7 and 10.0[+-]2.3 nmol/mg cell protein/60 min at low and high toluene concentrations, respectively. In vivo pretreatment of rats with acetone and phenobarbital increased the formation of metabolites: at low toluene concentrations 3- and 5-fold, respectively; at high toluene concentrations no significant increase (acetone) and 8-fold increase (phenobarbital). Apparent inhibition by ethanol, 7 and 60 mM, was most prominent at low toluene concentrations: 63% and 69%, respectively, in control cells; 84% and 91% in acetone-pretreated cells, and 32% (not significant) and 51% in phenobarbital-pretreated cells. Ethanol also caused accumulation of benzyl alcohol. The apparent inhibition by isoniazid was similar to that of ethanol at low toluene concentrations. Control and acetone-pretreated cells were apparently resistant towards metyrapone; the decrease was 49% and 64% in phenobarbital-pretreated cells at low and high toluene concentrations, respectively. In these cells, the decrease in presence of combined ethanol and metyrapone was 95% (low toluene concentrations). 4-Methylpyrazole decreased metabolite formation extensively in all groups. Benzaldehyde was only found in the presence of an aldehyde dehydrogenase inhibitor. Increased ratio benzoic/hippuric acid was observed at high toluene concentrations. These results demonstrate that toluene oxidation may be studied by product formation in isolated hepatocytes. However, the influence of various enzymes in the overall metabolism could not be ascertained due to lack of inhibitor specificity. (orig.).

  20. Remote Sensing

    CERN Document Server

    Khorram, Siamak; Koch, Frank H; van der Wiele, Cynthia F

    2012-01-01

    Remote Sensing provides information on how remote sensing relates to the natural resources inventory, management, and monitoring, as well as environmental concerns. It explains the role of this new technology in current global challenges. "Remote Sensing" will discuss remotely sensed data application payloads and platforms, along with the methodologies involving image processing techniques as applied to remotely sensed data. This title provides information on image classification techniques and image registration, data integration, and data fusion techniques. How this technology applies to natural resources and environmental concerns will also be discussed.

  1. Profiling and relative quantification of phosphatidylethanolamine based on acetone stable isotope derivatization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiang [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Wei, Fang, E-mail: willasa@163.com [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Xu, Ji-qu; Lv, Xin; Dong, Xu-yan [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Han, Xianlin [Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL 32827 (United States); College of Basic Medical Sciences, Zhejiang Chinese Medical University, 548 Bingwen Road, Hangzhou, Zhejiang 310053 (China); Quek, Siew-young [School of Chemical Science, The University of Auckland, Auckland 1142 (New Zealand); Huang, Feng-hong [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Chen, Hong, E-mail: chenhong@oilcrops.cn [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China)

    2016-01-01

    Phosphatidylethanolamine (PE) is considered to be one of the pivotal lipids for normal cellular function as well as disease initiation and progression. In this study, a simple, efficient, reliable, and inexpensive method for the qualitative analysis and relative quantification of PE, based on acetone stable isotope derivatization combined with double neutral loss scan-shotgun electrospray ionization tandem-quadrupole mass spectrometry analysis (ASID-DNLS-Shotgun ESI-MS/MS), was developed. The ASID method led to alkylation of the primary amino groups of PE with an isopropyl moiety. The use of acetone (d{sub 0}-acetone) and deuterium-labeled acetone (d{sub 6}-acetone) introduced a 6 Da mass shift that was ideally suited for relative quantitative analysis, and enhanced sensitivity for mass analysis. The DNLS model was introduced to simultaneously analyze the differential derivatized PEs by shotgun ESI-MS/MS with high selectivity and accuracy. The reaction specificity, labeling efficiency, and linearity of the ASID method were thoroughly evaluated in this study. Its excellent applicability was validated by qualitative and relative quantitative analysis of PE species presented in liver samples from rats fed different diets. Using the ASID-DNLS-Shotgun ESI-MS/MS method, 45 PE species from rat livers have been identified and quantified in an efficient manner. The level of total PEs tended to decrease in the livers of rats on high fat diets compared with controls. The levels of PE 32:1, 34:3, 34:2, 36:3, 36:2, 42:10, plasmalogen PE 36:1 and lyso PE 22:6 were significantly reduced, while levels of PE 36:1 and lyso PE 16:0 increased. - Highlights: • A novel isotope reagent acetone was explored for the derivatization of PEs. • The labeling reaction was carried out under mild conditions with high specificity. • Enhanced detection sensitivity of PEs was achieved after derivatization. • The ASID-DNLS-Shotgun MS/MS method was used to relative quantification of PEs.

  2. APPLICATION OF INFRARED SPECTROSCOPY TO THE ANALYSIS OF INORGANIC NITRATES. PHASE 1. SPECTRA OF INORGANIC NITRATES IN ACETONE AND THE USE OF SUCH SPECTRA IN ANALYTICAL CHEMISTRY

    Science.gov (United States)

    A study was made of the spectra of soluble inorganic nitrates in acetone solution and the use of such spectra in analytical chemistry . The spectra of...solubilities of anhydrous inorganic nitrates in acetone. The applications of the spectra of inorganic nitrates in acetone to analytical chemistry is

  3. Insights on Clusters Formation Mechanism by Time of Flight Mass Spectrometry. 2. The Case of Acetone-Water Clusters

    Science.gov (United States)

    Apicella, B.; Li, X.; Passaro, M.; Russo, C.

    2016-11-01

    This paper is the second of a series dealing with clusters formation mechanism. In part 1, water clusters with the addition of an electrophilic molecule such as ethanol were studied by Time Of Flight Mass Spectrometry (TOFMS). Mass distributions of molecular clusters of ethanol, water and ethanol-water mixed clusters, were obtained by means of two different ionization methods: Electron Ionization (EI) and picosecond laser Photo-Ionization (PI) at a wavelength of 355 nm. In part 2, the same experimental approach was employed to obtain mass spectra of clusters generated by acetone-water binary mixtures with a different composition. Strong dependence of the mass spectra of clusters with EI and PI on the acetone-water mixing ratio was observed. It was shown that the spectral pattern changes gradually and water-rich cluster signals become fainter while acetone-rich cluster signals become more intensive with increasing acetone concentrations from 0.3% to 40%. Owing to the hydrogen bond acceptor character of acetone, its self-association is discouraged with respect to ethanol. The autocorrelation function (AF) was used to analyze the variation of the water clusters composition with the increase of the acetone concentration in terms of fundamental periodicities. However, although acetone and ethanol present a very different hydrogen-bonding ability, similarly to ethanol-water system, in acetone-water system the formation of water-rich clusters and subsequent metastable fragmentation are the dominant process that determine the clusters distribution, irrespective of the ionization process, while the ionization process significantly affects the acetone-rich clusters distribution.

  4. DSC and curing kinetics study of epoxy grouting diluted with furfural -acetone slurry

    Science.gov (United States)

    Yin, H.; Sun, D. W.; Li, B.; Liu, Y. T.; Ran, Q. P.; Liu, J. P.

    2016-07-01

    The use of furfural-acetone slurry as active diluents of Bisphenol-A epoxy resin (DGEBA) groutings has been studied by dynamic and non-isothermal DSC for the first time. Curing kinetics study was investigated by non-isothermal differential scanning calorimetries at different heating rates. Activation enery (Ea) was calculated based on Kissinger and Ozawa Methods, and the results showed that Ea increased from 58.87 to 71.13KJ/mol after the diluents were added. The furfural-acetone epoxy matrix could cure completely at the theoretical curing temperature of 365.8K and the curing time of 139mins, which were determined by the kinetic model parameters.

  5. Electron Thermal Capacity in Plasma Generated at Cavitation Bubble Collapse in D-acetone

    CERN Document Server

    Kostenko, B F

    2004-01-01

    The latest experimental data on nuclear reaction product registration at cavitation bubble collapse in deuterated acetone (C$_3$D$_6$O) still argue in favour of existence of a new possibility to realize the thermonuclear synthesis. Theoretical description based on numerical solution of simultaneous conservation equations for gaseous and liquid phases also confirms this possibility, although it requires further more precise definitions. In particular, description of electron degrees of freedom in very dense nonequilibrium plasma generated at the final stage of bubble collapse needs specification. In the present paper, calculations of electron thermal capacity in the deuterated acetone multiple ionization region at electron temperatures $T_e \\simeq 10^4 $ K and above and compression range $\\rho/\\rho_0 \\simeq 1 \\div 100$ have been fulfilled on the basis of direct numerical solution of equation for chemical potential.

  6. Production of acetone, butanol, and ethanol from biomass of the green seaweed Ulva lactuca.

    Science.gov (United States)

    van der Wal, Hetty; Sperber, Bram L H M; Houweling-Tan, Bwee; Bakker, Robert R C; Brandenburg, Willem; López-Contreras, Ana M

    2013-01-01

    Green seaweed Ulva lactuca harvested from the North Sea near Zeeland (The Netherlands) was characterized as feedstock for acetone, ethanol and ethanol fermentation. Solubilization of over 90% of sugars was achieved by hot-water treatment followed by hydrolysis using commercial cellulases. A hydrolysate was used for the production of acetone, butanol and ethanol (ABE) by Clostridium acetobutylicum and Clostridium beijerinckii. Hydrolysate-based media were fermentable without nutrient supplementation. C. beijerinckii utilized all sugars in the hydrolysate and produced ABE at high yields (0.35 g ABE/g sugar consumed), while C. acetobutylicum produced mostly organic acids (acetic and butyric acids). These results demonstrate the great potential of U. lactuca as feedstock for fermentation. Interestingly, in control cultures of C. beijerinckii on rhamnose and glucose, 1,2 propanediol was the main fermentation product (9.7 g/L).

  7. Technical and economic assessment of processes for the production of butanol and acetone

    Science.gov (United States)

    1982-01-01

    This report represents a preliminary technical and economic evaluation of a process which produces mixed solvents (butaol/acetone/ethanol) via fermentation of sugars derived from renewable biomass resources. The objective is to assess the technology of producing butanol/acetone from biomass, and select a viable process capable of serving as a base case model for technical and economic analysis. It is anticipated that the base case process developed herein can then be used as the basis for subsequent studies concerning biomass conversion processes capable of producing a wide range of chemicals. The general criteria utilized in determining the design basis for the process are profit potential and non-renewable energy displacement potential. The feedstock chosen, aspen wood, was selected from a number of potential renewable biomass resources as the most readily available in the United States and for its relatively large potential for producing reducing sugars.

  8. Kinetic Model of Resin-Catalyzed Decomposition of Acetone Cyanohydrin in Organic Solvent

    Institute of Scientific and Technical Information of China (English)

    章亭洲; 杨立荣; 朱自强; 吴坚平

    2003-01-01

    Decomposition of acetone cyanohydrin is the first-step reaction for preparing (S)-α-cyano-3-phenoxybenzyl alcohol (CPBA) by the one-pot method in organic media. Considering the compatibility of biocatalysts with chemical catalysts and the successive operation in the bioreactor, anion exchange resin (D301) was used as catalyst for this reaction. External diffusion limitation was excluded by raising rotational speed to higher than 190r·min-1 in both solvents. Internal diffusion limitation was verified to be insignificant in this reaction system. The effect of acetone cyanohydrin concentration on the reaction was also investigated. An intrinsic kinetic model was proposed when the mass transfer limitation was excluded, and the average deviation of the model is 10.5%.

  9. Graphene oxide foams and their excellent adsorption ability for acetone gas

    Energy Technology Data Exchange (ETDEWEB)

    He, Yongqiang [Department of Applied Chemistry, Yuncheng University, Yuncheng 044000 (China); School of Science, Tianjin University, Tianjin 300072 (China); Zhang, Nana; Wu, Fei; Xu, Fangqiang; Liu, Yu [School of Science, Tianjin University, Tianjin 300072 (China); Gao, Jianping, E-mail: jianpingg@eyou.com [School of Science, Tianjin University, Tianjin 300072 (China)

    2013-09-01

    Graphical abstract: - Highlights: • GO and RGO foams were prepared using a simple and green method, unidirectional freeze-drying. • The porous structure of the foams can be adjusted by changing GO concentrations. • GO and RGO foams show good adsorption efficiency for acetone gas. - Abstract: Graphene oxide (GO) and reduced graphene oxide (RGO) foams were prepared using a unidirectional freeze-drying method. These porous carbon materials were characterized by thermal gravimetric analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy and scanning electron microscopy. The adsorption behavior of the two kinds of foams for acetone was studied. The result showed that the saturated adsorption efficiency of the GO foams was over 100%, and was higher than that of RGO foams and other carbon materials.

  10. Various Preconcentrator Structures For Determination of Acetone in a Wide Range of Concentration

    Directory of Open Access Journals (Sweden)

    Artur Maciej Rydosz

    2016-01-01

    Full Text Available In this paper, the investigation results on preconcentration of acetone at various initial concentrations are presented. The structures were made of conventional materials, such as stainless steel, quartz tube as well as fabricated in MEMS technology - micropreconcentrators. All structures have the same ‘active’ area to obtain more suitable comparison. The adsorbent materials were selected from commercial available Sigma-Aldrich Carbon Adsorbent Sampler Kit, consisting of 8 various adsorbents. The highest concentration factors were obtained by utilization of micropreconcentrator filled with Carboxen-1018, which is recommended for adsorption of C2-C3 compounds. The preconcentrators were placed into microsystem, and semiconductor gas sensor array was used as a detector unit. The microsystem was previously tested and designed for exhaled breath acetone analysis. The obtained results show that micropreconcentrator can be a useful tool for an increasing sensor sensitivity.

  11. Detection of acetone in exhaled breath with the use of micropreconcentrator and a commercial gas sensor

    Science.gov (United States)

    Michoń, Dagmara; Rydosz, Artur; Domański, Krzysztof; Maziarz, Wojciech; Pisarkiewicz, Tadeusz

    2016-12-01

    This paper presents investigation results obtained with the measuring system enabling detection of acetone with concentrations lower than 1 ppm. In the experiment we used both conventional preconcentrators made from materials such as stainless steel and quartz tubes and a micropreconcentrator manufactured in MEMS technology. The active volume of all preconcentrators was equal to enable comparisons of their performance. As a gas detector at the output of the measurement system we used both commercial semiconductor gas sensor and a mass spectrometer for comparison purposes. The obtained results show that the measurement system with micropreconcentrator and a commercial gas sensor can be used for detection of low level acetone present in the air exhaled by diabetics.

  12. Proton transfer reactions between nitric acid and acetone, hydroxyacetone, acetaldehyde and benzaldehyde in the solid phase.

    Science.gov (United States)

    Lasne, Jérôme; Laffon, Carine; Parent, Philippe

    2012-12-01

    The heterogeneous and homogeneous reactions of acetone, hydroxyacetone, acetaldehyde and benzaldehyde with solid nitric acid (HNO(3)) films have been studied with Reflection-Absorption Infrared Spectroscopy (RAIRS) under Ultra-High Vacuum (UHV) conditions in the 90-170 K temperature range. In the bulk or at the surface of the films, nitric acid transfers its proton to the carbonyl function of the organic molecules, producing protonated acetone-H(+), hydroxyacetone-H(+), acetaldehyde-H(+) and benzaldehyde-H(+), and nitrate anions NO(3)(-), a reaction not observed when nitric acid is previously hydrated [J. Lasne, C. Laffon and Ph. Parent, Phys. Chem. Chem. Phys., 2012, 14, 697]. This provides a molecular-scale description of the carbonyl protonation reaction in an acid medium, the first step of the acid-catalyzed condensation of carbonyl compounds, fuelling the growth of secondary organic aerosols (SOA) in the atmosphere.

  13. Glucose Sensing

    CERN Document Server

    Geddes, Chris D

    2006-01-01

    Topics in Fluorescence Spectroscopy, Glucose Sensing is the eleventh volume in the popular series Topics in Fluorescence Spectroscopy, edited by Drs. Chris D. Geddes and Joseph R. Lakowicz. This volume incorporates authoritative analytical fluorescence-based glucose sensing reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. Glucose Sensing is an essential reference for any lab working in the analytical fluorescence glucose sensing field. All academics, bench scientists, and industry professionals wishing to take advantage of the latest and greatest in the continuously emerging field of glucose sensing, and diabetes care & management, will find this volume an invaluable resource. Topics in Fluorescence Spectroscopy Volume 11, Glucose Sensing Chapters include: Implantable Sensors for Interstitial Fluid Smart Tattoo Glucose Sensors Optical Enzyme-based Glucose Biosensors Plasmonic Glucose Sens...

  14. Uptake of acetone, ethanol and benzene to snow and ice: effects of surface area and temperature

    Science.gov (United States)

    Abbatt, J. P. D.; Bartels-Rausch, T.; Ullerstam, M.; Ye, T. J.

    2008-10-01

    The interactions of gas-phase acetone, ethanol and benzene with smooth ice films and artificial snow have been studied. In one technique, the snow is packed into a cylindrical column and inserted into a low-pressure flow reactor coupled to a chemical-ionization mass spectrometer for gas-phase analysis. At 214 and 228 K, it is found for acetone and ethanol that the adsorbed amounts per surface area match those for adsorption to thin films of ice formed by freezing liquid water, when the specific surface area of the snow (as determined from Kr adsorption at 77 K) and the geometric surface area of the ice films are used. This indicates that freezing thin films of water leads to surfaces that are smooth at the molecular level. Experiments performed to test the effect of film growth on ethanol uptake indicate that uptake is independent of ice growth rate, up to 2.4 µm min-1. In addition, traditional Brunauer-Emmett-Teller (BET) experiments were performed with these gases on artificial snow from 238 to 266.5 K. A transition from a BET type I isotherm indicative of monolayer formation to a BET type II isotherm indicative of multilayer uptake is observed for acetone at T>=263 K and ethanol at T>=255 K, arising from solution formation on the ice. When multilayer formation does not occur, as was the case for benzene at T<=263 K and for acetone at T<=255 K, the saturated surface coverage increased with increasing temperature, consistent with the quasi-liquid layer affecting adsorption prior to full dissolution/multilayer formation.

  15. Uptake of acetone, ethanol and benzene to snow and ice: effects of surface area and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Abbatt, J P D; Bartels-Rausch, T; Ullerstam, M; Ye, T J [Department of Chemistry, University of Toronto, 80 St George Street, Toronto, ON M5S 3H6 (Canada)

    2008-10-15

    The interactions of gas-phase acetone, ethanol and benzene with smooth ice films and artificial snow have been studied. In one technique, the snow is packed into a cylindrical column and inserted into a low-pressure flow reactor coupled to a chemical-ionization mass spectrometer for gas-phase analysis. At 214 and 228 K, it is found for acetone and ethanol that the adsorbed amounts per surface area match those for adsorption to thin films of ice formed by freezing liquid water, when the specific surface area of the snow (as determined from Kr adsorption at 77 K) and the geometric surface area of the ice films are used. This indicates that freezing thin films of water leads to surfaces that are smooth at the molecular level. Experiments performed to test the effect of film growth on ethanol uptake indicate that uptake is independent of ice growth rate, up to 2.4 {mu}m min{sup -1}. In addition, traditional Brunauer-Emmett-Teller (BET) experiments were performed with these gases on artificial snow from 238 to 266.5 K. A transition from a BET type I isotherm indicative of monolayer formation to a BET type II isotherm indicative of multilayer uptake is observed for acetone at T{>=}263 K and ethanol at T{>=}255 K, arising from solution formation on the ice. When multilayer formation does not occur, as was the case for benzene at T{<=}263 K and for acetone at T{<=}255 K, the saturated surface coverage increased with increasing temperature, consistent with the quasi-liquid layer affecting adsorption prior to full dissolution/multilayer formation.

  16. Optimization of Wastewater Microalgae Pretreatment for Acetone, Butanol, and Ethanol Fermentation

    OpenAIRE

    Castro, Yessica A.

    2014-01-01

    Acetone-butanol-ethanol (ABE) fermentation from wastewater microalgae by Clostridium saccharoperbutylacetonicum N1-4 is a novel bioprocess that utilizes waste substrate to generate valuable solvents. Butanol, the most abundant product resulting from ABE fermentation, is an environmentally safe and high performing fuel that can be utilized as a drop-in-fuel; however, high operational costs and low ABE yield present challenge in scale-up of the process. The utilization of algae as a substrate r...

  17. Surface tension isotherms of the dioxane-acetone-water and glycerol-ethanol-water ternary systems

    Science.gov (United States)

    Dzhambulatov, R. S.; Dadashev, R. Kh.; Elimkhanov, D. Z.; Dadashev, I. N.

    2016-10-01

    The results of the experimental and theoretical studies of the concentration dependence of surface tension of aqueous solutions of the 1,4-dioxane-acetone-water and glycerol-ethanol-water ternary systems were given. The studies were performed by the hanging-drop method on a DSA100 tensiometer. The maximum error of surface tension was 1%. The theoretical models for calculating the surface tension of the ternary systems of organic solutions were analyzed.

  18. Shock-Tube Measurement of Acetone Dissociation Using Cavity-Enhanced Absorption Spectroscopy of CO.

    Science.gov (United States)

    Wang, Shengkai; Sun, Kai; Davidson, David F; Jeffries, Jay B; Hanson, Ronald K

    2015-07-16

    A direct measurement for the rate constant of the acetone dissociation reaction (CH3COCH3 = CH3CO + CH3) was conducted behind reflected shock wave, utilizing a sub-ppm sensitivity CO diagnostic achieved by cavity-enhanced absorption spectroscopy (CEAS). The current experiment eliminated the influence from secondary reactions and temperature change by investigating the clean pyrolysis of shock-tube kinetics studies.

  19. Micromachined silicon plates for sensing molecular interactions

    NARCIS (Netherlands)

    Carlen, E.T.; Weinberg, M.S.; Dube, C.E.; Zapata, A.M.; Borenstein, J.T.

    2006-01-01

    A micromachined surface stress sensor based on a thin suspended crystalline silicon circular plate measures differential surface stress changes associated with vapor phase chemisorption of an alkanethiol self-assembled monolayer. The isolated face of the suspended silicon plate serves as the sensing

  20. Sources and sinks of acetone, methanol, and acetaldehyde in North Atlantic air

    Directory of Open Access Journals (Sweden)

    A. C. Lewis

    2005-03-01

    Full Text Available Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and 5 acetaldehyde contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene. The observations showed anomalies in the variance and abundance of acetaldehyde and acetone 10 over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass mo15 tion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.

  1. Sources and sinks of acetone, methanol, and acetaldehyde in North Atlantic marine air

    Directory of Open Access Journals (Sweden)

    A. C. Lewis

    2005-01-01

    Full Text Available Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and acetaldehyde contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene. The observations showed anomalies in the variance and abundance of acetaldehyde and acetone over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass motion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.

  2. Metal-Exchanged β Zeolites as Catalysts for the Conversion of Acetone to Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Aurora J. Cruz-Cabeza

    2012-01-01

    Full Text Available Various metal-β zeolites have been synthesized under similar ion-exchange conditions. During the exchange process, the nature and acid strength of the used cations modified the composition and textural properties as well as the Brönsted and Lewis acidity of the final materials. Zeolites exchanged with divalent cations showed a clear decrease of their surface Brönsted acidity and an increase of their Lewis acidity. All materials were active as catalysts for the transformation of acetone into hydrocarbons. Although the protonic zeolite was the most active in the acetone conversion (96.8% conversion, the metal-exchanged zeolites showed varied selectivities towards different products of the reaction. In particular, we found the Cu-β to have a considerable selectivity towards the production of isobutene from acetone (over 31% yield compared to 7.5% of the protonic zeolite. We propose different reactions mechanisms in order to explain the final product distributions.

  3. Vertical fluxes and atmospheric cycling of methanol, acetaldehyde, and acetone in a coastal environment

    Directory of Open Access Journals (Sweden)

    M. Yang

    2013-03-01

    Full Text Available We present here vertical fluxes of methanol, acetaldehyde, and acetone measured directly with eddy covariance (EC during March to July 2012 near the southwest coast of the UK. The performance of the proton-transfer reaction mass spectrometer (PTR-MS for flux measurement is characterized, with additional considerations given to the homogeneity and stationarity assumptions required by EC. Concentrations and fluxes of these compounds vary significantly with time of day and wind direction. Higher values of acetaldehyde and acetone are usually observed in the daytime and from the direction of a forested park, most likely due to light-driven emissions from terrestrial plants. Methanol concentration and flux do not demonstrate clear diel variability, suggesting sources in addition to plants. We estimate air–sea exchange and photochemical rates of these compounds, which are compared to measured vertical fluxes. For acetaldehyde, the mean (1σ concentration of 0.13 (0.02 ppb at night may be maintained by oceanic emission, while photochemical destruction outpaces production during the day. Air-sea exchange and photochemistry are probably net sinks of methanol and acetone in this region. Their nighttime concentrations of 0.46 (0.20 and 0.39 (0.08 ppb appear to be affected more by terrestrial emissions and long distance transport, respectively.

  4. FTIR study of acetone oxime interaction with H-ZSM-5 and Cu-ZSM-5

    Science.gov (United States)

    Simakov, Andrey V.; Stoyanov, Evgenii S.; Rebrov, Evgenii V.; Sazonova, N. N.

    2004-08-01

    Copper based catalysts are of great importance as catalysts for NO removal from exhaust industrial gases. Earlier authors have shown that NO reaction with acetone oxime (AO) is the rate determining step of NO catalytic reduction by propane over Cu-ZSM-5 catalyst at temperatures below 300oC. Aim of the present work is to clarify the peculiarities of acetone oxime coordination over surface of H-ZSM-5 zeolite and that doped with Cu(II) and Cu(I)-cations. We studied AO coordination in CCl4 solutions and then data obtained were used for analysis of spectra of AO adsorbed on pure zeolite and that dopped with Cu (I) and Cu (II) cations. It was shown that there are monomers and several associates of AO in CCl4 solution differing in size and type of bonding with their own characteristic bands in IR spectra. The spectrum of acetone oxime adsorbed on pure zeolite includes non symmetrical band at 1710 cm-1 due to AO strongly bonded with zeolite surface through H-bond. There are four AO adspecies on zeolite dopped with copper with two different types of AO coordination to Cu(I) or to Cu(II) cations: one with participation of O atom and another one with N atom. Complexes of AO with Cu(I) ions are much more stable then those with Cu(II) ions.

  5. Fenton oxidation of 2, 4-and 2, 6-dinitrotoluene and acetone inhibition

    Institute of Scientific and Technical Information of China (English)

    Yiliang HE; Bin ZHAO; Joseph B.HUGHES; Sunh Soo HAN

    2008-01-01

    The performances and kinetic parameters of Fenton oxidation of 2, 4- and 2, 6-dinitrotoluene (DNT) in water-acetone mixtures and explosive contaminated soil washing-out solutions were investigated at a labor-atory scale. The experimental results show that acetone can be a significant hydroxyl radical scavenger and result in serious inhibition of Fenton oxidation of 2, 4- and 2, 6-DNT. Although no serious inhibition was found in con-taminated soil washing-out solutions, longer reaction time was needed to remove 2, 4- and 2, 6-DNT completely, mainly due to the competition of hydroxyl radicals. Fenton oxidation of 2, 4- and 2, 6-DNT fit well with the first-order kinetics and the presence of acetone also reduced DNT's degradation kinetics. Based on the com-parison and matching of retention time and ultraviolet (UV) spectra between high performance liquid chromato-graphy (HPLC) and standards, the following reaction pathway for 2, 4-DNT primary degradation was pro-posed: 2, 4-DNT→2, 4-dinitro-benzaldehyde→2, 4-dini-trobenzoic acid→1, 3-dinitrobenzene→3-nitrophenol.

  6. Toxicity study of di(2-ethylhexyl)phthalate (DEHP) in combination with acetone in rats

    DEFF Research Database (Denmark)

    Dalgaard, M.; Østergaard, G.; Lam, Henrik Rye

    2000-01-01

    In two separate studies with exposure duration 9 weeks or 4 weeks, male Wistar rats were dosed with di(2-ethylhexyl)phthalate (DEHP) by gavage and exposed to drinking water with or without acetone (0.5% wt/v in the 9-week study, 1.0% wt/v in the 4-week study). In the 9-week study the doses of DEHP...... were 0, 125, 250, 500 or 1000 mg/kg b.wt. In the 4-week study the doses of DEHP were increased to 1000, 5000 and 10,000 mg/kg b.wt. In the 9-week study, the relative liver weight was increased in the rats exposed to 500 and 1000 mg/kg b.wt. No interaction of DEHP and acetone was observed in any...... of the measured parameters. In the 4-week study DEHP, at the highest dose level, resulted in severe general toxicity. The group exposed to DEHP in combination with acetone was more affected. Male fertility was decreased. Body weight was decreased, and the relative weight of the liver, kidney, heart, brain...

  7. Pyrolysis of furfural-acetone resin as matrix precursor for new carbon materials

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to increase the understanding of the pyrolysis mechanism,Fourier transform infrared spectroscopy (FT-IR) and thermogravimetry-mass spectrometric coupling technique (TG-MS) were used to study the pyrolysis behavior of furfural-acetone resin used for new carbon materials.The curing and carbonization mechanisms of furfural-acetone resin were mainly investigated;structural changes and volatile products evolved during pyrolysis were analyzed.The results indicate that,during pyrolysis of furfural-acetone resin adding 7% (mass fraction) phosphorous acid as curing agent,the rupture of C-O bond in the five-membered heterocycle firstly takes place to release oxygen atoms and then does the C--H bond,which enable the molecular chain to cross-link and condense,then lead to the formation of three dimensional networking structure.With the increase of pyrolyzing temperature,the scission of methyl and the opening of furan ring are generated.As a result,the recomposition of molecular chain structure isgenerated and a hexatomic fused ring containing double bonds is built.The main volatile products during pyrolysis of furfuralacetone resin are H2O,and a small mount of CO,CO2 and CH4.At elevated temperatures,dehydrogenation takes place and hydrogen gas is evolved.

  8. Iron bromide vapor laser

    Science.gov (United States)

    Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

    2016-03-01

    We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

  9. Solvents and vapor intrusion pathways.

    Science.gov (United States)

    Phillips, Scott D; Krieger, Gary R; Palmer, Robert B; Waksman, Javier C

    2004-08-01

    Vapor intrusion must be recognized appropriately as a separate pathway of contamination. Although many issues resemble those of other forms of contamination (particularly its entryway, which is similar to that of radon seepage), vapor intrusion stands apart as a unique risk requiring case-specific action. This article addresses these issues and the current understanding of the most appropriate and successful remedial actions.

  10. Vapor phase heat transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Hedstrom, J.C.; Neeper, D.A.

    1985-09-01

    This report describes progress in theoretical and experimental investigations of various forms of a vapor transport system for solar space heating, which could also be applied to service water heating. Refrigerant is evaporated in a solar collector, which may be located on the external wall or roof of a building. The vapor is condensed in a passively discharged thermal storage unit located within the building. The condensed liquid can be returned to the collector either by a motor-driven pump or by a completely passive self-pumping mechanism in which the vapor pressure lifts the liquid from the condenser to the collector. The theoretical investigation analyzes this self-pumping scheme. Experiments in solar test cells compare the operation of both passive and active forms of the vapor system with the operation of a passive water wall. The vapor system operates as expected, with potential advantages over other passive systems in design flexibility and energy yield.

  11. 33 CFR 154.828 - Vapor recovery and vapor destruction units.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vapor recovery and vapor... SECURITY (CONTINUED) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154.828 Vapor recovery and vapor destruction units. (a) The inlet to a vapor recovery unit...

  12. Conductometric Sensors for Detection of Elemental Mercury Vapor

    Science.gov (United States)

    Ryan, M. A.; Homer, M. L.; Shevade, A. V.; Lara, L. M.; Yen, S.-P. S.; Kisor, A. K.; Manatt, K. S.

    2008-01-01

    Several organic and inorganic materials have been tested for possible incorporation into a sensing array in order to add elemental mercury vapor to the suite of chemical species detected. Materials have included gold films, treated gold films, polymer-carbon composite films, gold-polymer-carbon composite films and palladium chloride sintered films. The toxicity of mercury and its adverse effect on human and animal health has made environmental monitoring of mercury in gas and liquid phases important (1,2). As consumer products which contain elemental mercury, such as fluorescent lighting, become more widespread, the need to monitor environments for the presence of vapor phase elemental mercury will increase. Sensors in use today to detect mercury in gaseous streams are generally based on amalgam formation with gold or other metals, including noble metals and aluminum. Recently, NASA has recognized a need to detect elemental mercury vapor in the breathing atmosphere of the crew cabin in spacecraft and has requested that such a capability be incorporated into the JPL Electronic Nose (3). The detection concentration target for this application is 10 parts-per-billion (ppb), or 0.08 mg/m3. In order to respond to the request to incorporate mercury sensing into the JPL Electronic Nose (ENose) platform, it was necessary to consider only conductometric methods of sensing, as any other transduction method would have required redesign of the platform. Any mercury detection technique which could not be incorporated into the existing platform, such as an electrochemical technique, could not be considered.

  13. A Lithium Vapor Box similarity experiment employing water vapor

    Science.gov (United States)

    Schwartz, Ja; Jagoe, C.; Goldston, Rj; Jaworski, Ma

    2016-10-01

    Handling high power loads and heat flux in the divertor is a major challenge for fusion power plants. A detached plasma will likely be required. However, hydrogenic and impurity puffing experiments show that detached operation leads easily to X-point MARFEs, impure plasmas, degradation in confinement, and lower helium pressure at the exhaust. The concept of the Lithium Vapor Box Divertor is to use local evaporation and strong differential pumping through condensation to localize the gas-phase material that absorbs the plasma heat flux, and so avoid those difficulties. In order to design such a box first the vapor without plasma must be simulated. The density of vapor required can be estimated using the SOL power, major radius, poloidal box length, and cooling energy per lithium atom. For an NSTX-U-sized machine, the Knudsen number Kn spans 0.01 to 1, the transitional flow regime. This regime cannot handled by fluid codes or collisionless Monte Carlo codes, but can be handled by Direct Simulation Monte Carlo (DSMC) codes. To validate a DSMC model, we plan to build a vapor box test stand employing more-convenient water vapor instead of lithium vapor as the working fluid. Transport of vapor between the chambers at -50C will be measured and compared to the model. This work supported by DOE Contract No. DE-AC02-09CH11466.

  14. Reaction Kinetics of Acetone Peroxide Formation and Structure Investigations Using Raman Spectroscopy and X-ray Diffraction

    DEFF Research Database (Denmark)

    Jensen, Lars; Mortensen, Peter Mølgaard; Trane, Rasmus

    2009-01-01

    Triacetone triperoxide (TATP) has been prepared in order to study the effect of pH and temperature on the reaction kinetics. Raman spectra of liquid mixtures of acetone and hydrogen peroxide were recorded versus time throughout the experiments. The spectral data of the liquid phases indicate...... that at 25 degrees C the reaction between acetone and hydrogen peroxide proceeds to form intermediates within one day. Based on the assumption that a likely reaction path involves a sequence of reaction steps between acetone and hydrogen peroxide, calculations of Raman spectra were performed using a density...... functional theory (DFT)/Hartree-Fock approach. It was not possible from this to assess with certainty which intermediate products formed most extensively in an acetone/hydrogen peroxide mixture. However, it was concluded that the most likely reaction mixture is a mixture of the different intermediate...

  15. First discovery of acetone extract from cottonseed oil sludge as a novel antiviral agent against plant viruses.

    Science.gov (United States)

    Zhao, Lei; Feng, Chaohong; Hou, Caiting; Hu, Lingyun; Wang, Qiaochun; Wu, Yunfeng

    2015-01-01

    A novel acetone extract from cottonseed oil sludge was firstly discovered against plant viruses including Tobacco mosaic virus (TMV), Rice stripe virus (RSV) and Southern rice black streaked dwarf virus (SRBSDV). Gossypol and β-sitosterol separated from the acetone extract were tested for their effects on anti-TMV and analysed by nuclear magnetic resonance (NMR) assay. In vivo and field trials in different geographic distributions and different host varieties declared that this extract mixture was more efficient than the commercial agent Ningnanmycin with a broad spectrum of anti-plant-viruses activity. No phytotoxic activity was observed in the treated plants and environmental toxicology showed that this new acetone extract was environmentally friendly, indicating that this acetone extract has potential application in the control of plant virus in the future.

  16. Vapor pressure measured with inflatable plastic bag

    Science.gov (United States)

    1965-01-01

    Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

  17. Co-production of acetone and ethanol with molar ratio control enables production of improved gasoline or jet fuel blends.

    Science.gov (United States)

    Baer, Zachary C; Bormann, Sebastian; Sreekumar, Sanil; Grippo, Adam; Toste, F Dean; Blanch, Harvey W; Clark, Douglas S

    2016-10-01

    The fermentation of simple sugars to ethanol has been the most successful biofuel process to displace fossil fuel consumption worldwide thus far. However, the physical properties of ethanol and automotive components limit its application in most cases to 10-15 vol% blends with conventional gasoline. Fermentative co-production of ethanol and acetone coupled with a catalytic alkylation reaction could enable the production of gasoline blendstocks enriched in higher-chain oxygenates. Here we demonstrate a synthetic pathway for the production of acetone through the mevalonate precursor hydroxymethylglutaryl-CoA. Expression of this pathway in various strains of Escherichia coli resulted in the co-production of acetone and ethanol. Metabolic engineering and control of the environmental conditions for microbial growth resulted in controllable acetone and ethanol production with ethanol:acetone molar ratios ranging from 0.7:1 to 10.0:1. Specifically, use of gluconic acid as a substrate increased production of acetone and balanced the redox state of the system, predictively reducing the molar ethanol:acetone ratio. Increases in ethanol production and the molar ethanol:acetone ratio were achieved by co-expression of the aldehyde/alcohol dehydrogenase (AdhE) from E. coli MG1655 and by co-expression of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) from Z. mobilis. Controlling the fermentation aeration rate and pH in a bioreactor raised the acetone titer to 5.1 g L(-1) , similar to that obtained with wild-type Clostridium acetobutylicum. Optimizing the metabolic pathway, the selection of host strain, and the physiological conditions employed for host growth together improved acetone titers over 35-fold (0.14-5.1 g/L). Finally, chemical catalysis was used to upgrade the co-produced ethanol and acetone at both low and high molar ratios to higher-chain oxygenates for gasoline and jet fuel applications. Biotechnol. Bioeng. 2016;113: 2079-2087. © 2016 Wiley

  18. Bionanomaterials and Bioinspired Nanostructures for Selective Vapor Sensing

    Science.gov (United States)

    2013-04-03

    RFID Handbook. Fundamentals and Applications in Contactless Smart Cards and Identification. Hoboken, NJ: Wiley www.annualreviews.org • Materials for...sensors that adapt wireless communication concepts originally developed for radio-frequency identification ( RFID ) tags are also known as RFID sensors (144...quantitation with passive 13.56-MHz radio frequency identification ( RFID ) sensors. Talanta 75:624–28 57. Potyrailo RA, Morris WG, Sivavec T, Tomlinson HW

  19. Chemical Vapor Sensing with Monolayer MoS2

    Science.gov (United States)

    2013-01-04

    hydrogen atoms are light gray. Nano Letters Letter dx.doi.org/10.1021/nl3043079 | Nano Lett. XXXX, XXX, XXX−XXXE ■ REFERENCES (1) Geim, A. K.; Novoselov , K...Association: Austin, TX, 2011; http://www. itrs.net. (3) Novoselov , K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Griorieva, I. V...Blake, P.; Katsnelson, M. I.; Novoselov , K. S. Detection of individual gas molecules adsorbed on graphene. Nat. Mater. 2007, 6, 652−655. (15) Dan

  20. Remote Sensing.

    Science.gov (United States)

    Williams, Richard S., Jr.; Southworth, C. Scott

    1983-01-01

    The Landsat Program became the major event of 1982 in geological remote sensing with the successful launch of Landsat 4. Other 1982 remote sensing accomplishments, research, publications, (including a set of Landsat worldwide reference system index maps), and conferences are highlighted. (JN)

  1. Resonance-Enhanced Raman Spectroscopy on Explosives Vapor at Standoff Distances

    Directory of Open Access Journals (Sweden)

    Anneli Ehlerding

    2012-01-01

    Full Text Available Resonance-enhanced Raman spectroscopy has been used to perform standoff measurements on nitromethane (NM, 2,4-DNT, and 2,4,6-TNT in vapor phase. The Raman cross sections for NM, DNT, and TNT in vapor phase have been measured in the wavelength range 210–300 nm under laboratory conditions, in order to estimate how large resonance enhancement factors can be achieved for these explosives. The results show that the signal is enhanced up to 250,000 times for 2,4-DNT and up to 60,000 times for 2,4,6-TNT compared to the nonresonant signal at 532 nm. Realistic outdoor measurements on NM in vapor phase at 13 m distance were also performed, which indicate a potential for resonance Raman spectroscopy as a standoff technique for detection of vapor phase explosives. In addition, the Raman spectra of acetone, ethanol, and methanol were measured at the same wavelengths, and their influence on the spectrum from NM was investigated.

  2. Electrospray droplet exposure to organic vapors: metal ion removal from proteins and protein complexes.

    Science.gov (United States)

    DeMuth, J Corinne; McLuckey, Scott A

    2015-01-20

    The exposure of aqueous nanoelectrospray droplets to various organic vapors can dramatically reduce sodium adduction on protein ions in positive ion mass spectra. Volatile alcohols, such as methanol, ethanol, and isopropanol lead to a significant reduction in sodium ion adduction but are not as effective as acetonitrile, acetone, and ethyl acetate. Organic vapor exposure in the negative ion mode, on the other hand, has essentially no effect on alkali ion adduction. Evidence is presented to suggest that the mechanism by which organic vapor exposure reduces alkali ion adduction in the positive mode involves the depletion of alkali metal ions via ion evaporation of metal ions solvated with organic molecules. The early generation of metal/organic cluster ions during the droplet desolvation process results in fewer metal ions available to condense on the protein ions formed via the charged residue mechanism. These effects are demonstrated with holomyoglobin ions to illustrate that the metal ion reduction takes place without detectable protein denaturation, which might be revealed by heme loss or an increase in charge state distribution. No evidence is observed for denaturation with exposure to any of the organic vapors evaluated in this work.

  3. Atmospheric Hydrodeoxygenation of Biomass Fast Pyrolysis Vapor by MoO3

    DEFF Research Database (Denmark)

    Zhou, Guofeng; Jensen, Peter Arendt; Le, Duy Michael

    2016-01-01

    MoO3 has been tested as a catalyst in hydrodeoxygenation (HDO) of both model compounds (acetone and guaiacol) and real biomass pyrolysis vapors under atmospheric pressure. The pyrolysis vapor was obtained by fast pyrolysis of wood or lignin in a continuous fast pyrolysis reactor at a fixed...... temperature of 500 °C, and it subsequently passed through a downstream, close coupled, fixed bed reactor containing the MoO3 catalyst. The influences of the catalyst temperature and the concentration of H2 on the HDO of the pyrolysis vapors were investigated. The level of HDO of the biomass pyrolysis vapors......, which is inactive in HDO. The catalyst experienced severe reduction at temperatures higher than 400 °C. The yields of coke relative to the fed biomass were in the range of 3–4 wt %daf for lignin and 5–6 wt %daf for wood. Compared to untreated bio-oil the upgraded lignin organic liquid showed improved...

  4. First lidar measurements of water vapor and aerosols from a high-altitude aircraft

    Science.gov (United States)

    Browell, Edward V.; Ismail, Syed

    1995-01-01

    Water vapor plays an important role in many atmospheric processes related to radiation, climate change, atmospheric dynamics, meteorology, the global hydrologic cycle, and atmospheric chemistry, and yet our knowledge of the global distribution of water vapor is very limited. The differential absorption lidar (DIAL) technique has the potential of providing needed high resolution water vapor measurements from aircraft and from space, and the Lidar Atmospheric Sensing Experiment (LASE) is a key step in the development of this capability. The LASE instrument is the first fully engineered, autonomous DIAL system, and it is designed to operate from a high-altitude aircraft (ER-2) and to make water vapor and aerosol profile measurements across the troposphere. The LASE system was flown from the NASA Wallops Flight Facility in a series of engineering flights during September 1994. This paper discusses the characteristics of the LASE system and presents the first LASE measurements of water vapor and aerosol profiles.

  5. Multiwavelength Strontium Vapor Lasers

    Science.gov (United States)

    Soldatov, A. N.; Yudin, N. A.

    2016-08-01

    Based on an analysis of experimental and theoretical works, modern notion on conditions of forming of population density inversion on self-terminating IR transitions of alkali-earth metals is given. It is demonstrated that there is a significant difference in the inversion formation in lasers on self-terminating transitions in the visible and near-IR ranges and lasers on self-terminating transitions of alkali-earth metals lasing IR lines in the mid-IR range. It is shown that in the discharge circuit of lasers on self-terminating metal atom transitions (LSMT) there are processes strengthening the influence of the known mechanism limiting the frequency and energy characteristics (FEC) of radiation caused by the presence of prepulse electron concentration. The mechanism of influence of these processes on FEC of the LSMT and technical methods of their neutralization are considered. The possibility of obtaining average lasing power of ~200 W from one liter volume of the active medium of the strontium vapor laser is demonstrated under conditions of neutralization of these processes.

  6. Archimedes Mass Filter Vaporizer

    Science.gov (United States)

    Putvinski, S.; Agnew, A. F.; Cluggish, B. P.; Ohkawa, T.; Sevier, L.; Umstadter, K. R.; Dresvin, S. V.; Kuteev, B. V.; Feygenson, O. N.; Ivanov, D. V.; Zverev, S. G.; Miroshnikov, I. V.; Egorov, S. M.; Kiesewetter, D. V.; Maliugin, V. I.

    2001-10-01

    Archimedes Technology Group, Inc., is developing a plasma mass separator called the Archimedes Filter that separates waste oxide mixtures ion by ion into two mass groups: light and heavy. Since high-level waste at Hanford has 99.9its radioactivity associated with heavy elements, the Archimedes Filter can effectively decontaminate over three-quarters of that waste. The Filter process involves some preprocessing followed by volatilization and separation by the magnetic and electric fields of the main plasma. This presentation describes the approach to volatilization of the waste oxy-hydroxide mixture by means of a very high heat flux (q > 10 MW/m2). Such a high heat flux is required to ensure congruent evaporation of the complex oxy-hydroxide mixture and is achieved by injection of small droplets of molten waste into an inductively coupled plasma (ICP) torch. This presentation further addresses different issues related to evaporation of the waste including modeling of droplet evaporation, estimates of parameters of plasma torch, and 2D modeling of the plasma. The experimental test bed for oxide vaporization and results of the initial experiments on oxide evaporation in 60 kW ICP torch will also be described.

  7. Acetone gas sensor based on NiO/ZnO hollow spheres: Fast response and recovery, and low (ppb) detection limit.

    Science.gov (United States)

    Liu, Chang; Zhao, Liupeng; Wang, Boqun; Sun, Peng; Wang, Qingji; Gao, Yuan; Liang, Xishuang; Zhang, Tong; Lu, Geyu

    2017-06-01

    NiO/ZnO composites were synthesized by decorating numerous NiO nanoparticles on the surfaces of well dispersed ZnO hollow spheres using a facile solvothermal method. Various kinds of characterization methods were utilized to investigate the structures and morphologies of the hybrid materials. The results revealed that the NiO nanoparticles with a size of ∼10nm were successfully distributed on the surfaces of ZnO hollow spheres in a discrete manner. As expected, the NiO/ZnO composites demonstrated dramatic improvements in sensing performances compared with pure ZnO hollow spheres. For example, the response of NiO/ZnO composites to 100ppm acetone was ∼29.8, which was nearly 4.6 times higher than that of primary ZnO at 275°C, and the response/recovery time were 1/20s, respectively. Meanwhile, the detection limit could extend down to ppb level. The likely reason for the improved gas sensing properties was also proposed.

  8. Puffing and micro-explosion behavior in combustion of butanol/Jet A-1 and acetone-butanol-ethanol (A-B-E)/Jet A-1 fuel droplets

    CERN Document Server

    Rao, D Chaitanya Kumar; Som, S K

    2016-01-01

    The present investigation deals with the puffing and micro-explosion characteristics in the combustion of a single droplet comprising butanol/Jet A-1, acetone-butanol-ethanol (A-B-E)/Jet A-1 blends, and A-B-E. The onset of nucleation, growth of vapor bubble and subsequent breakup of droplet for various fuel blends have been analyzed from the high-speed images. Puffing was observed to be the dominant phenomenon in 30% butanol blend, while micro-explosion was found to be the dominant one in other fuel blends (blend with 50% butanol or 30% A-B-E or 50% A-B-E). It was observed that puffing always preceded the micro-explosion. The probability of micro-explosion in droplets with A-B-E blends was found to be higher than that of butanol blends. Although the rate of bubble growth was almost similar for all butanol and A-B-E blends, the final bubble diameter before the droplet breakup was found to be higher for 50/50 blends than that of 30/70 blends. The occurrence of micro-explosion shortened the droplet lifetime, and...

  9. Water Vapor Products from Differential-InSAR with Auxiliary Calibration Data: Accuracy and Statistics

    Science.gov (United States)

    Gong, W.; Meyer, F. J.; Webley, P.

    2014-12-01

    Although water vapor disturbance has been long term recognized as the major error source in differential Interferometric Synthetic Aperture Radar (d-InSAR) techniques for the ground deformation monitoring and topography reconstruction, it provides opportunities to extract the atmospheric water-vapor information from satellite SAR imageries that can be further used to support studies on earth energy budget, climate, the hydrological cycle, and meteorological forecasting, etc. The water vapor contribution in interferometric phases is normally referred as the atmospheric delay dominated by water vapor rather than condensed water (e.g. cloud). D-InSAR can produce maps of the column water vapor amounts (equivalent to integrated water vapor (IWV) or Precipitable Water Vapor (PWV) in other literatures) that are important parameters quantitatively describe the total amount of water vapor overlying a point on the earth surface. Similar products have been operationally produced in multi-spectrum remote sensing, e.g. Moderate-resolution Imaging Spectroradiometer (MODIS) with a spatial resolution in 500 m to 1km; Whereas, the PWV products derived by d-InSAR have remarkably high spatial resolution that can capture fine scale of water vapor variations in space as small as tens of meters or even less. In recent years, some efforts have been made to derive the water vapor products from interferogram and analyze the corresponding products quality, such as studies comparing integrated water vapor derived from interferometric phases to other measurements (e.g. MERIS, MODIS, GNSS), studies on deriving absolute water vapor products from d-InSAR, and studies on integrating d-InSAR water vapor products in meteorological numerical forecast. In this study, considering these limitation factors and based on previous studies, we discuss the accuracy and statistics of the water vapor products from satellite SAR, including (1) Accuracy of the differential water vapor products; (2) Sources of

  10. Modeling vapor dominated geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Marconcini, R.; McEdwards, D.; Neri, G.; Ruffilli, C.; Schroeder, R.; Weres, O.; Witherspoon, P.

    1977-09-12

    The unresolved questions with regard to vapor-dominated reservoir production and longevity are reviewed. The simulation of reservoir behavior and the LBL computer program are discussed. The geology of Serrazzano geothermal field and its reservoir simulation are described. (MHR)

  11. Vapor Intrusion Facilities - South Bay

    Data.gov (United States)

    U.S. Environmental Protection Agency — POINT locations for the South Bay Vapor Instrusion Sites were derived from the NPL data for Region 9. One site, Philips Semiconductor, was extracted from the...

  12. Multi-species time-history measurements during high-temperature acetone and 2-butanone pyrolysis

    KAUST Repository

    Lam, Kingyiu

    2013-01-01

    High-temperature acetone and 2-butanone pyrolysis studies were conducted behind reflected shock waves using five species time-history measurements (ketone, CO, CH3, CH4 and C2H4). Experimental conditions covered temperatures of 1100-1600 Kat 1.6 atm, for mixtures of 0.25-1.5% ketone in argon. During acetone pyrolysis, the CO concentration time-history was found to be strongly sensitive to the acetone dissociation rate constant κ1 (CH3COCH3 → CH3 + CH3CO), and this could be directly determined from the CO time-histories, yielding κ1(1.6 atm) = 2.46 × 1014 exp(-69.3 [kcal/mol]/RT) s-1 with an uncertainty of ±25%. This rate constant is in good agreement with previous shock tube studies from Sato and Hidaka (2000) [3] and Saxena et al. (2009) [4] (within 30%) at temperatures above 1450 K, but is at least three times faster than the evaluation from Sato and Hidaka at temperatures below 1250 K. Using this revised κ1 value with the recent mechanism of Pichon et al. (2009) [5], the simulated profiles during acetone pyrolysis show excellent agreement with all five species time-history measurements. Similarly, the overall 2-butanone decomposition rate constant κtot was inferred from measured 2-butanone time-histories, yielding κ tot(1.5 atm) = 6.08 × 1013 exp(-63.1 [kcal/mol]/RT) s -1 with an uncertainty of ±35%. This rate constant is approximately 30% faster than that proposed by Serinyel et al. (2010) [11] at 1119 K, and approximately 100% faster at 1412 K. Using the measured 2-butanone and CO time-histories and an O-atom balance analysis, a missing removal pathway for methyl ketene was identified. The rate constant for the decomposition of methyl ketene was assumed to be the same as the value for the ketene decomposition reaction. Using the revised κtot value and adding the methyl ketene decomposition reaction to the Serinyel et al. mechanism, the simulated profiles during 2-butanone pyrolysis show good agreement with the measurements for all five species.

  13. Recovery of dilute acetone-butanol-ethanol (ABE) solvents from aqueous solutions via membrane distillation

    Energy Technology Data Exchange (ETDEWEB)

    Banat, F.A.; Al-Shannag, M. [Jordan Univ. of Science and Technology, Irbid (Jordan). Dept. of Chemical Engineering

    2000-12-01

    The simultaneous recovery of dilute acetone-butanol-ethanol (ABE) solvents from aqueous solutions by air gap membrane distillation was theoretically assessed. A previously developed and validated Stefan-Maxwell based mathematical model was used for this purpose. It was found that membrane distillation could successfully be used for the recovery of these solvents. Interestingly it was found that butanol could be separated with the highest selectivity and flux though it has the highest boiling point. The effect of operating conditions such as feed and cooling surface temperatures, air gap width, and individual component concentration on the flux and selectivity of these solvents was examined and discussed in this paper. (orig.)

  14. OPTIMIZATION OF PRODUCTION OF 5-HYDROXYMETHYLFURFURAL FROM GLUCOSE IN A WATER: ACETONE BIPHASIC SYSTEM

    Directory of Open Access Journals (Sweden)

    A. D. M. Mendonça

    2015-06-01

    Full Text Available Abstract5-Hydroxymethylfurfural (HMF is considered to be an important building block for biorefineries and has a high potential for the production of chemicals and fuels. Production of HMF from glucose was studied using phosphoric acid as catalyst, in a water:acetone system with volume ratio of 1:2 and NaCl. An experimental design was applied to examine the influence of temperature, time and concentration of catalyst on the HMF yield. HMF yields of more than 50 % were obtained when using 200 ºC, 8.4 min and 0.8% of catalyst. The temperature is the main factor influencing the HMF yield.

  15. DFT Study on the (S)-Proline-catalyzed Direct Aldol Reaction between Acetone and 4-Nitrobenzaldehyde

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    DFT/6-31G* calculations were applied to study the direct aldol reaction between acetone and 4-nitrobenzaldehyde catalyzed by (S)-proline. Four transition states associated with the stereo-controlling step, corresponding to syn and anti arrangements of methylene moiety related to the carboxylic acid group in enamine intermediate and re and si attacks to the aldehyde carbonyl carbon have been obtained. The solvent effect of DMSO was investigated with polarized continuum model. The computed energies of transition states reveal the stereo-selectivity of the reaction.

  16. Poly[[aquadi-μ3-malonato-hexaphenyl­ditin(IV)] acetone solvate

    OpenAIRE

    2010-01-01

    The asymmetric unit of the title polymeric complex, {[Sn2=(C6H5)6(C3H2O4)(H2O)]·C3H6O}n, comprises of two Sn cations, one malonate anion and a non-coordinating acetone solvent molecule. Both crystallographically independent Sn cations are five-coordinated by two O and three C atoms in a distorted trigonal-bipyrimidal geometry. One of the Sn cations is bridged by the malonate units, affording polymeric chains which run along [001]. Weak intramolecular C—H...π intera...

  17. Different sensing mechanisms in single wire and mat carbon nanotubes chemical sensors

    CERN Document Server

    Neumann, P L; Dobrik, G; Kertész, K; Horváth, E; Lukács, I E; Biró, L P; Horváth, Z E

    2014-01-01

    Chemical sensing properties of single wire and mat form sensor structures fabricated from the same carbon nanotube (CNT) materials have been compared. Sensing properties of CNT sensors were evaluated upon electrical response in the presence of five vapours as acetone, acetic acid, ethanol, toluene, and water. Diverse behaviour of single wire CNT sensors was found, while the mat structures showed similar response for all the applied vapours. This indicates that the sensing mechanism of random CNT networks cannot be interpreted as a simple summation of the constituting individual CNT effects, but is associated to another robust phenomenon, localized presumably at CNT-CNT junctions, must be supposed.

  18. Vapor Leak Sensor Using Polarization Property and Stereoscopic Measurement for Plant Inspection

    Science.gov (United States)

    Nakashima, Toshiro; Nakajima, Hajime; Matoba, Osamu

    This paper reports a sensor for the plant inspections to detect leaking vapor. Plants are usually inspected by patrolling inspectors. It requires high level skills to selectively detect abnormal phenomena occurring in various types of equipment under the complicated environments. In this research, we developed a remote detecting sensor for the vapor leaking from piping, which is one of the priority control items inside plants. The basic principle of the sensor is specifically to sense the scattered light when laser beam is illuminated on the vapor. It is also discovered in our basic experiments that there is big difference in the polarization property between the light scattered by vapor and surface structures inside plants. The sensor can discriminate the light scattered by vapor from other types of scattered light utilizing the difference of the polarization property, then detecting the light scattered by vapor only. A prototype model is fabricated for substantiating the basic property of leaking vapor detection. As a result, it is confirmed that the prototype model not only has sufficient detecting capability, but can selectively detect vapor only. In conclusion, it is confirmed that the developed sensor satisfies the requirements for the plant inspection sensors, and has sufficient capability for practical usage.

  19. A Review of Vapor Intrusion Models

    OpenAIRE

    Yao, Yijun; Suuberg, Eric M.

    2013-01-01

    A complete vapor intrusion (VI) model, describing vapor entry of volatile organic chemicals (VOCs) into buildings located on contaminated sites, generally consists of two main parts-one describing vapor transport in the soil and the other its entry into the building. Modeling the soil vapor transport part involves either analytically or numerically solving the equations of vapor advection and diffusion in the subsurface. Contaminant biodegradation must often also be included in this simulatio...

  20. Recent advances in vapor intrusion site investigations.

    Science.gov (United States)

    McHugh, Thomas; Loll, Per; Eklund, Bart

    2017-02-22

    Our understanding of vapor intrusion has evolved rapidly since the discovery of the first high profile vapor intrusion sites in the late 1990s and early 2000s. Research efforts and field investigations have improved our understanding of vapor intrusion processes including the role of preferential pathways and natural barriers to vapor intrusion. This review paper addresses recent developments in the regulatory framework and conceptual model for vapor intrusion. In addition, a number of innovative investigation methods are discussed.

  1. Oxygenated compounds in aged biomass burning plumes over the Eastern Mediterranean: evidence for strong secondary production of methanol and acetone

    Directory of Open Access Journals (Sweden)

    R. Holzinger

    2004-10-01

    Full Text Available Airborne measurements of acetone, methanol, PAN, acetonitrile (by Proton Transfer Reaction Mass Spectrometry, and CO (by Tunable Diode Laser Absorption Spectroscopy have been performed during the Mediterranean Intensive Oxidants Study (MINOS, August 2001. In the course of the campaign 10 biomass burning plumes, identified by strongly elevated acetonitrile mixing ratios, were found. The characteristic biomass burning signatures obtained from these plumes reveal secondary production of acetone and methanol, while CO photochemically declines in the plumes. Mean excess mixing ratios – normalized to CO – of 1.8%, 0.20%, 3.8%, and 0.65% for acetone, acetonitrile, methanol, and PAN, respectively, were found in the plumes. By scaling to an assumed global annual source of 663–807 Tg CO, biomass burning emissions of 25–31 and 29–35 Tg/yr for acetone and methanol are estimated, respectively. Our measurements suggest that the present biomass burning contributions of acetone and methanol are significantly underestimated due to the neglect of secondary formation. Median acetonitrile mixing ratios throughout the troposphere were around 150 pmol/mol; this is in accord with current biomass burning inventories and an atmospheric lifetime of ~6 months.

  2. Conversion of Alcohols to Bromides by Trimethylsilane and lithium Bromide in Acetone

    Institute of Scientific and Technical Information of China (English)

    Wei Feng; Zhang Xiao-xia; Zhang Qing; Wang Ji-yu; Chen Dai-mo

    2004-01-01

    Conversion of alcohols to alkyl bromides is one of the most frequently used functional group transformation reactions. Phosphorus tribromide is one of the most popular classical reagents.Triphenylphosphine has been used in combination with bromine,carbon tetrabromide,N-halo imides and other bromide compounds as a mild reagents for the preparation of alkyl bromides.More reacently, halotrimethylsilanes were found to be useful for halogenation of alcohols. George A.Olah successfully converted alcohols to bromides with chlorotrimethylsilane/lithium bromide in acetonitrile. But in our research, we found that we got no bromides but methylation products when we planed to convered our substances to bromides according to Gerge's method. We did some experiments, and we found that when the substituent group in the 2-N was donor group,we got the methylation products,but when it was acceptor group,the bromide could be got.(Scheme 1).Then we did some experiments with several other solvents, we found excitedly that when the solvent was acetone ,the bromides could be got even the substituent group was donor.(Scheme 2).When we changed the substances to normal alcohols ,such as ethyl alcohol,benzyl alcohol,isopropyl alcohol and 3,4-dimethoxy benzyl alcohol,we also got the bromides.In conclusion, we found a simple method to convert alcohols to bromides with trimethylsilane/li thium bromide in acetone,which was better than Geroge's method.

  3. Acetone mediated electrophoretic deposition of nanocrystalline SDC on NiO-SDC ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Bhosale, A.G. [Smt. Kusumtai Rajarambapu Patil Kanya Mahavidyalaya, Islampur 415409, Maharashtra (India); Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India); Joshi, Rajeev [Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India); Department of Technology, D.Y Patil University, Kolhapur 416006, Maharashtra (India); Subhedar, K.M. [Department of Electrical Engineering, The Technion - Israel Institute of Technology, Haifa 32000 (Israel); Mishra, R. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India); Pawar, S.H., E-mail: pawar_s_h@yahoo.co [Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India); Department of Technology, D.Y Patil University, Kolhapur 416006, Maharashtra (India)

    2010-07-30

    Films of Ce{sub 0.8}Sm{sub 0.2}O{sub 1.9} (SDC) were electrophoretically deposited on non-conducting NiO-SDC ceramics using the suspension of nanocrystalline SDC in acetone. The effect of iodine addition on suspension stability was investigated by measuring the zeta potential of SDC particle and pH of the suspension. The highest zeta potential was 42.1 mV with the addition of 2 mg iodine at pH 5.7 indicating formation of relatively stable suspension. The particle size distribution reveals the agglomerate size of SDC in acetone with iodine addition was of the order of 222 nm. The surface morphology and sintering effect on grain growth of the deposited films were investigated by scanning electron microscope (SEM). The structural investigation of the sintered film was done by X-ray diffraction (XRD) technique and it revealed phase pure SDC with cubic structure. Impedance study of sintered SDC/NiO-SDC hetero-structure showed decrease in total resistance with increase in temperature.

  4. Central nervous system activity of an aqueous acetonic extract of Ficus carica L. in mice

    Directory of Open Access Journals (Sweden)

    Mittal M Bhanushali

    2014-01-01

    Full Text Available Background: Ficus carica Linn. is reported to possess variety of activities, but its potential in CNS disorders is still to be explored. Objective: The present study was carried out to evaluate the CNS depressant activity of aqueous acetonic extract of Ficus carica Linn on different models in mice. Materials and Methods: The aerial parts of the plant Ficus carica L. were extracted with aqueous acetone and the solvent was removed by rotary vacuum evaporator under reduced pressure. A crude extract was given orally and its effects were tested on ketamine-induced sleeping time, muscle-coordination, anxiety (elevated-plus maze and Staircase test, convulsions [maximal electroshock (MES and pentylenetetrazole (PTZ-induced seizures], and nociception. In addition, we determined the levels of neurotransmitters, norepinephrine (NE and 5-hydroxytryptamine (5-HT. Results: Results from the experimental models tested showed: (1 a delay on onset and prolongation of sleep of ketamine-induced sleeping time; (2 significant muscle relaxant activity; (3 a significant attenuation in the anxiety-response (4 a delay in the onset of seizures and reduction in duration of seizures and mortality induced by MES and PTZ; (5 a reduction in the licking time in nociception test and (6 increased levels of NE and 5-HT. Conclusion: This suggests that Ficus carica L. exerts its CNS depressive effect by modulating the neurotransmitters NE and 5-HT in the brain.

  5. Simultaneous saccharification and fermentation of lignocellulosic residues pretreated with phosphoric acid-acetone for bioethanol production.

    Science.gov (United States)

    Li, Hui; Kim, Nag-Jong; Jiang, Min; Kang, Jong Won; Chang, Ho Nam

    2009-07-01

    Bermudagrass, reed and rapeseed were pretreated with phosphoric acid-acetone and used for ethanol production by means of simultaneous saccharification and fermentation (SSF) with a batch and fed-batch mode. When the batch SSF experiments were conducted in a 3% low effective cellulose, about 16 g/L of ethanol were obtained after 96 h of fermentation. When batch SSF experiments were conducted with a higher cellulose content (10% effective cellulose for reed and bermudagrass and 5% for rapeseed), higher ethanol concentrations and yields (of more than 93%) were obtained. The fed-batch SSF strategy was adopted to increase the ethanol concentration further. When a higher water-insoluble solid (up to 36%) was applied, the ethanol concentration reached 56 g/L of an inhibitory concentration of the yeast strain used in this study at 38 degrees C. The results show that the pretreated materials can be used as good feedstocks for bioethanol production, and that the phosphoric acid-acetone pretreatment can effectively yield a higher ethanol concentration.

  6. Organosolv pretreatment of rice straw for efficient acetone, butanol, and ethanol production.

    Science.gov (United States)

    Amiri, Hamid; Karimi, Keikhosro; Zilouei, Hamid

    2014-01-01

    Acetone-butanol-ethanol (ABE) was produced from rice straw using a process containing ethanol organosolv pretreatment, enzymatic hydrolysis, and fermentation by Clostridium acetobutylicum bacterium. Pretreatment of the straw with 75% (v/v) aqueous ethanol containing 1% w/w sulfuric acid at 150 °C for 60 min resulted in the highest total sugar concentration of 31 g/L in the enzymatic hydrolysis. However, the highest ABE concentration and productivity (10.5 g/L and 0.20 g/Lh, respectively) were obtained from the straw pretreated at 180 °C for 30 min. Enzymatic hydrolysis of the straw pretreated at 180 °C for 30 min with 5% solid loading resulted in glucose yield of 46.2%, which was then fermented to 80.3 g butanol, 21.1 g acetone, and 22.5 g ethanol, the highest overall yield of ABE production. Thus, the organosolv pretreatment can be applied for efficient production of the solvents from rice straw.

  7. Recent progress on industrial fermentative production of acetone-butanol-ethanol by Clostridium acetobutylicum in China.

    Science.gov (United States)

    Ni, Ye; Sun, Zhihao

    2009-06-01

    China is one of the few countries, which maintained the fermentative acetone-butanol-ethanol (ABE) production for several decades. Until the end of the last century, the ABE fermentation from grain was operated in a few industrial scale plants. Due to the strong competition from the petrochemical industries, the fermentative ABE production lost its position in the 1990s, when all the solvent fermentation plants in China were closed. Under the current circumstances of concern about energy limitations and environmental pollution, new opportunities have emerged for the traditional ABE fermentation industry since it could again be potentially competitive with chemical synthesis. From 2006, several ABE fermentation plants in China have resumed production. The total solvent (acetone, butanol, and ethanol) production capacity from ten plants reached 210,000 tons, and the total solvent production is expected to be extended to 1,000,000 tons (based on the available data as of Sept. 2008). This article reviews current work in strain development, the continuous fermentation process, solvent recovery, and economic evaluation of ABE process in China. Challenges for an economically competitive ABE process in the future are also discussed.

  8. Acetone cataluminescence as an indicator for evaluation of heterogeneous base catalysts in biodiesel production.

    Science.gov (United States)

    Zhang, Lijuan; Chen, Yingchun; He, Nan; Lu, Chao

    2014-01-07

    Rapid and effective evaluation techniques for heterogeneous base catalysts in biodiesel production are highly desirable with increased global demand for biofuels. In this work, we have discovered direct connections between the number of medium-strength basic sites of heterogeneous base catalysts in biodiesel production and cataluminescence intensity in acetone aldol condensation reactions. Accordingly, acetone cataluminescence has been employed as an indicator for rapid evaluation of heterogeneous base catalysts in biodiesel production. Its practical feasibility has been first established using commercially available heterogeneous base catalysts in biodiesel production (including MgO, Al2O3, TiO2, and ZnO), indicating a good matching between the proposed cataluminescence screening method and routine temperature-programmed desorption measurements. Subsequently, the proposed cataluminescence method can be used to effectively distinguish a set of layered double hydroxides and layered double oxide with fewer differences of basic sites, and the relative standard deviation (RSD) of the proposed method is 2.90%. The developed cataluminescence platform is able to take advantage of low cost, simple configuration, fast response, long-term stability, and easy operation. This work has a great potential in distinguishing weak/strong basic sites and even acidic sites of each catalyst system by tuning molecular probes.

  9. Micronization of Griseofulvin by Ress in Supercritical CO2 with Cosolvent Acetone

    Institute of Scientific and Technical Information of China (English)

    胡国勤; 陈鸿雁; 蔡建国; 邓修

    2003-01-01

    Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).

  10. Theoretical study on the mechanism of cycloaddition between dimethyl methylene carbene and acetone

    Institute of Scientific and Technical Information of China (English)

    LU Xiuhui; WU Weirong; YU Haibin; XU Yuehua

    2005-01-01

    The mechanism of the cycloaddition reaction of singlet dimethyl methylene carbene and acetone has been studied by using second-order Moller-Plesset perturbation and density functional theory. The geometrical parameters, harmonic vibrational frequencies and energy of stationary points on the potential energy surface are calculated by MP2/6-31G* and B3LYP/6-31G* methods. The results show that path b of the cycloaddition reaction (1) would be the major reactive channel of the cycloaddition reaction between singlet dimethyl methylene carbene and acetone, which proceeds in two steps: i) The two reactants form an energy-rich intermediate (INT1b), which is an exothermic reaction of 23.3 kJ/mol with no energy barrier. ii) The intermediate INT1b isomerizes to a three-membered ring product (P1) via transition state TS1b with energy barrier of 22.2 kJ/mol. The reaction rate of this reaction and its competitive reactions do greatly differ, with excellent selectivity. In view of dynamics and thermodynamics, this reaction is suitable for occurring at 1 atm and temperature range of 300―800 K, in which the reaction will have not only the larger spontaneous tendency and equilibrium constant but also the faster reaction rate.

  11. The Influence of PEG400 and Acetone on Polysulfone Membrane Morphology and Fouling Behaviour

    Directory of Open Access Journals (Sweden)

    P.T.P. Aryanti

    2016-05-01

    Full Text Available Modification of polysulfone ultrafiltration membrane was conducted by blending polysulfone with PEG400 and acetone as additives. The influence of each additive on the resulted membrane morphology and fouling characteristics were investigated. The experimental results showed that the hydrophilicity of the polysulfone membrane was improved by the increase of PEG400 in the polysulfone membrane. The water contact angle of the membrane was decreased from 76.1° to 38.31° when 35 %wt of PEG400 was added into the polysulfone solution, while the water content of the membrane was increased by around 38%. The high concentration of PEG400 in the polysulfone solution led to the formation of longer finger-like cavities in the membrane structure and resulted in a thicker membrane skin layer. The high concentration of PEG400 also contributed to the increase in hydraulic resistance of the membrane due to organic matter fouling. This problem could be minimized by the addition of acetone into the polysulfone solution, which resulted in a lower fouling resistance of organic matter during up to five hours of peat water filtration.

  12. [Toluene, Benzene and Acetone Adsorption by Activated Carbon Coated with PDMS].

    Science.gov (United States)

    Liu, Han-bing; Jiang, Xin; Wang, Xin; Yang, Bing; Xue, Nan-dong; Zhang, Shi-lei

    2016-04-15

    To improve the adsorption selectivity of volatile organic compounds ( VOCs) , activated carbon ( AC) was modified by polydimethylsiloxane (PDMS) and characterized by BET analysis and Boehm titration. Dynamic adsorption column experiments were conducted and Yoon-Neslon(Y-N) model was used to identify adsorption effect for toluene, beuzene and acetone on AC when relative humidity was 0%, 50% and 90%, respectively. The results showed that the BET area, micropore volume and surface functional groups decreased with the PDMS modification, and surface hydrophobicity of the modified AC was enhanced leading to a lower water adsorption capacity. The results of dynamic adsorption showed that the adsorption kinetics and capacity of Bare-AC decreased with the increase of relative humidity, and the adsorption capacities of PDMS coated AC were 1.86 times (toluene) and 1.92 times (benzene) higher than those of Bare-AC, while a significant improvement of adsorption capacity for acetone was not observed. These findings suggest that polarity of molecule can be an important influencing factor for adsorption on hydrophobic surface developed by PDMS.

  13. The charging of neutral dimethylamine and dimethylamine-sulphuric acid clusters using protonated acetone

    Directory of Open Access Journals (Sweden)

    K. Ruusuvuori

    2014-11-01

    Full Text Available Sulphuric acid is generally considered one of the most important substances taking part in atmospheric particle formation. However, in typical atmospheric conditions in the lower troposphere sulphuric acid and water alone are unable to form particles. It has been suggested that strong bases may stabilize sulphuric acid clusters so that particle formation may occur. More to the point, amines – strong organic bases – have become the subject of interest as possible cause for such stabilisation. To probe whether amines play a role in atmospheric nucleation, we need to be able to measure accurately the gas-phase amine vapour concentration. Such measurements often include charging the neutral molecules and molecular clusters in the sample. Since amines are bases, the charging process should introduce a positive charge. This can be achieved for example using a positively charged reagent with a suitable proton affinity. In our study, we have used quantum chemical methods combined with a cluster dynamics code to study the use of acetone as a reagent in chemical ionization and compared the results with measurements performed with a chemical ionization atmospheric pressure interface time-of-flight mass spectrometer (CI-APi-TOF. The computational results indicate that protonated acetone is an effective reagent in chemical ionization. However, in the experiments the charger ions were not depleted at the predicted dimethylamine concentrations, indicating that either the modelling scheme or the experimental results – or both – contain unidentified sources of error.

  14. Lignin Hydrolysis and Phosphorylation Mechanism during Phosphoric Acid–Acetone Pretreatment: A DFT Study

    Directory of Open Access Journals (Sweden)

    Wu Qin

    2014-12-01

    Full Text Available The study focused on the structural sensitivity of lignin during the phosphoric acid–acetone pretreatment process and the resulting hydrolysis and phosphorylation reaction mechanisms using density functional theory calculations. The chemical stabilities of the seven most common linkages (β-O-4, β-β, 4-O-5, β-1, 5-5, α-O-4, and β-5 of lignin in H3PO4, CH3COCH3, and H2O solutions were detected, which shows that α-O-4 linkage and β-O-4 linkage tend to break during the phosphoric acid–acetone pretreatment process. Then α-O-4 phosphorylation and β-O-4 phosphorylation follow a two-step reaction mechanism in the acid treatment step, respectively. However, since phosphorylation of α-O-4 is more energetically accessible than phosphorylation of β-O-4 in phosphoric acid, the phosphorylation of α-O-4 could be controllably realized under certain operational conditions, which could tune the electron and hole transfer on the right side of β-O-4 in the H2PO4− functionalized lignin. The results provide a fundamental understanding for process-controlled modification of lignin and the potential novel applications in lignin-based imprinted polymers, sensors, and molecular devices.

  15. Antimicrobial activity of Aqueous, Ethanol and Acetone extracts of Sesbania grandiflora leaves and its phytochemical characterization

    Directory of Open Access Journals (Sweden)

    K. Padmalochana

    2014-12-01

    Full Text Available Plants are being highly explored as a major source of medicinal compounds due to the presence of various phytochemical groups. Leaves of Sesbania grandiflora was consumed in traditional medicinal system of Ayurveda for numerous harmful syndromes and infections. This present study was explored the various phytochemicals present in the plant leaves of S. grandiflora. The qualitative analysis of various phytochemicals was exploited using different solvent systems. The aqueous, 80% ethanol and 70% acetone extraction was carried out in this study. Ethanolic extract shown presence of high amount of Alkaloids, Tannins, Saponins, Glycosides and steroids were confirmed by formation of colour intensity during chemical reactions. All the three extracts were tested for antimicrobial activity against pathogenic micro-organisms especially methicillin resistant Staphylococcus aureus and dermatophytes Candida sp using Agar well diffusion method. Among these three extracts ethanol extracts shows good antibacterial activity compared with aqueous and acetone extracts. Because of the presence of alkaloids, flavonoids, tannins and steroids ethanol extract shows high antibacterial activity. So these active compounds can be used in the field of medicine as therapeutic agent.

  16. Lignin hydrolysis and phosphorylation mechanism during phosphoric acid-acetone pretreatment: a DFT study.

    Science.gov (United States)

    Qin, Wu; Wu, Lingnan; Zheng, Zongming; Dong, Changqing; Yang, Yongping

    2014-12-18

    The study focused on the structural sensitivity of lignin during the phosphoric acid-acetone pretreatment process and the resulting hydrolysis and phosphorylation reaction mechanisms using density functional theory calculations. The chemical stabilities of the seven most common linkages (β-O-4, β-β, 4-O-5, β-1, 5-5, α-O-4, and β-5) of lignin in H3PO4, CH3COCH3, and H2O solutions were detected, which shows that α-O-4 linkage and β-O-4 linkage tend to break during the phosphoric acid-acetone pretreatment process. Then α-O-4 phosphorylation and β-O-4 phosphorylation follow a two-step reaction mechanism in the acid treatment step, respectively. However, since phosphorylation of α-O-4 is more energetically accessible than phosphorylation of β-O-4 in phosphoric acid, the phosphorylation of α-O-4 could be controllably realized under certain operational conditions, which could tune the electron and hole transfer on the right side of β-O-4 in the H2PO4- functionalized lignin. The results provide a fundamental understanding for process-controlled modification of lignin and the potential novel applications in lignin-based imprinted polymers, sensors, and molecular devices.

  17. Acetone-soluble cellulose acetate extracted from waste blended fabrics via ionic liquid catalyzed acetylation.

    Science.gov (United States)

    Sun, Xunwen; Lu, Canhui; Zhang, Wei; Tian, Dong; Zhang, Xinxing

    2013-10-15

    Isolation of cellulose from waste polyester/cotton blended fabrics (WBFs) is a bottleneck for recycling and exploiting waste textiles. The objective of this study was to provide a new environmental-friendly and efficient approach for extracting cellulose derivatives and polyester from WBFs. A Bronsted acidic ionic liquid (IL) N-methyl-imidazolium bisulfate, [Hmim]HSO4, was used as a novel catalyst for acetylation of cellulose rather than a solvent with the aim to overcome low isolation efficiency associated with the very high viscosity and relatively high costs of ILs. The extraction yield of acetone-soluble cellulose acetate (CA) was 49.3%, which corresponded to a conversion of 84.5% of the cellulose in the original WBFs; meanwhile, 96.2% of the original poly(ethylene terephthalate) (PET) was recovered. The extracted CA was characterized by (1)H NMR, FTIR, XRD and TGA analysis, and the results indicated that high purity acetone-soluble CA and carbohydrate-free PET could be isolated in this manner from WBFs.

  18. Ro om temp erature gas sensing prop erty and sensing mechanism of Sn-dop ed ZnO thin film%Sn掺杂ZnO薄膜的室温气敏性能及其气敏机理∗

    Institute of Scientific and Technical Information of China (English)

    邢兰俊; 常永勤; 邵长景; 王琳; 龙毅

    2016-01-01

    Sn-doped ZnO and pure ZnO thin films are deposited on glass substrates with prepared electrode by the chemical vapor deposition method. The gas sensing performances of Sn-doped ZnO and pure ZnO thin films are investigated by our home-made system at room temperature, and the gas sensing test results reveal that Sn-doped ZnO thin film exhibits high gas response to ethanol and acetone, while no response is detected for pure ZnO to ethanol or acetone at room temperature. Sn-doped ZnO thin film also has high selectivity that the response to ethanol is higher than that to acetone in the same measurement conditions, and the response of Sn-doped ZnO thin film sample to ethanol is almost the third largest when the concentration is 320 ppm. The typical scanning electron microscopy images reveal that these two samples are tetrapod-shaped ZnO whiskers with diameters in a range of about 150–400 nm. X-ray diffraction results indicate that all the samples are of wurtzite structure. Neither trace of Sn, nor that of Sn alloy nor that of Sn oxide is detected in the Sn-doped ZnO film, while its diffraction peak shifts towards the left compared with that of pure ZnO sample, which suggests that Sn atoms exist in the form of interstitial atoms in the ZnO crystal. The energy dispersive spectrum shows that the Sn-doped ZnO thin film is composed of Zn and O elements, and no Sn signal is defected. Photoluminescence spectra reveal that both Sn-doped ZnO and pure ZnO films have ultraviolet light emission peaks and green emission peaks, while the intensities of the defect emissions are significantly enhanced by doping of Sn. In addition, no gas response to ethanol is detected after Sn-doped ZnO thin film has been annealed in the air, which indicates that the room temperature gas sensitivity of the Sn-doped ZnO thin film may be related to its high defect concentration. The working mechanism of Sn-doped ZnO thin film is explained by a free electron random scattering model. As is well known, Zn

  19. The Lithium Vapor Box Divertor

    Science.gov (United States)

    Goldston, Robert; Hakim, Ammar; Hammett, Gregory; Jaworski, Michael; Myers, Rachel; Schwartz, Jacob

    2015-11-01

    Projections of scrape-off layer width to a demonstration power plant suggest an immense parallel heat flux, of order 12 GW/m2, which will necessitate nearly fully detached operation. Building on earlier work by Nagayama et al. and by Ono et al., we propose to use a series of differentially pumped boxes filled with lithium vapor to isolate the buffering vapor from the main plasma chamber, allowing stable detachment. This powerful differential pumping is only available for condensable vapors, not conventional gases. We demonstrate the properties of such a system through conservation laws for vapor mass and enthalpy, and then include plasma entrainment and ultimately an estimate of radiated power. We find that full detachment should be achievable with little leakage of lithium to the main plasma chamber. We also present progress towards solving the Navier-Stokes equation numerically for the chain of vapor boxes, including self-consistent wall boundary conditions and fully-developed shocks, as well as concepts for an initial experimental demonstration-of-concept. This work supported by DOE Contract No. DE-AC02-09CH11466.

  20. Theoretical study on the vibrational state distribution of product CO in the photolysis of acetone CH3COCH3-→2CH3 + CO

    Institute of Scientific and Technical Information of China (English)

    李杏利; 李宗; 马思渝

    1999-01-01

    The photolysis of acetone has been studied at 6-311G basis set using unrestricted Hartree-Fock method. The results show that ground state acetone (S0) cannot easily dissociate. The electrons of acetone undergo n→Ⅱ transition in laser, and excited acetone (T1) can easily dissociate: and acetyl can further undergo thermolytic dissociation: CH3CO→CH3+CO(R2). The dynamic information (ωK, BKF, V0(S)) of reaction R2 is obtained and the vibrational state distributions of product CO are calculated. The calculated value consists with the experimental value.

  1. KINETIC STUDY OF SELECTIVE GAS-PHASE OXIDATION OF ISOPROPANOL TO ACETONE USING MONOCLINIC ZRO2 AS A CATALYST

    Directory of Open Access Journals (Sweden)

    Mohammad Sadiq

    2015-08-01

    Full Text Available Zirconia was prepared by a precipitation method and calcined at 723 K, 1023 K, and 1253 K in order to obtain monoclinic zirconia. The prepared zirconia was characterized by XRD, SEM, EDX, surface area and pore size analyzer, and particle size analyzer. Monoclinic ZrO2 as a catalyst was used for the gas-phase oxidation of isopropanol to acetone in a Pyrex-glass-flow-type reactor with a temperature range of 443 K - 473 K. It was found that monoclinic ZrO2 shows remarkable catalytic activity (68% and selectivity (100% for the oxidation of isopropanol to acetone. This kinetic study reveals that the oxidation of isopropanol to acetone follows the L-H mechanism.

  2. Suspension Plasma-Sprayed ZnFe2O4 Nanostructured Coatings for ppm-Level Acetone Detection

    Science.gov (United States)

    You, Jiajun; Chen, Xia; Zheng, Bingbing; Geng, Xin; Zhang, Chao

    2017-02-01

    Zinc ferrite (ZnFe2O4) sensitive coatings have been deposited by suspension plasma spraying. The phase constitution of the coatings was characterized by x-ray diffraction while the top surface and cross-sectional morphology of the coatings were inspected by scanning electron microscopy. The response to acetone was tested with the concentration in the range of 25-500 ppm at the working temperature from 175 to 275 °C. The sensors that were deposited at an arc current of 400 A showed better performance than those at 600 A owing to small grain size and high porosity. The sensor response increased with acetone concentration. The optimized sensors showed excellent response/recovery time and selectivity to acetone at 200 °C.

  3. Effect of Maclura pomifera total acetonic extract, pomiferin and osajin on the autooxidation of purified sunflower triacylglycerols

    Directory of Open Access Journals (Sweden)

    Hussein, Ahmed A.

    2005-03-01

    Full Text Available omiferin and osajin have been isolated from the acetonic extract of M. pomifera fruits. Effects of total acetonic extract, pomiferin and osajin on the autooxidation of purified sunflower triacylglycerol were studied. Pomiferin showed a high antioxidant activity whereas total acetonic extract showed moderate and osajin revealed a low activity.Se han aislado la pomiferina y la osajina del extracto de hexano del fruto de M. pomifera. Se han estudiado los efectos sobre la oxidación de triglicéridos purificados del aceite de girasol, del extracto de acetona, de la pomiferina y de la osajina. La pomiferina mostró una actividad antioxidante elevada en cambio, el extracto de acetona mostró una actividad moderada y la osajina baja.

  4. Measurements of integrated water vapor and cloud liquid water from microwave radiometers at the DOE ARM Cloud and Radiation Testbed in the U.S. Southern Great Plains

    Energy Technology Data Exchange (ETDEWEB)

    Liljegren, J.C. [Pacific Northwest Lab., Richland, WA (United States); Lesht, B.M.

    1996-06-01

    The operation and calibration of the ARM microwave radiometers is summarized. Measured radiometric brightness temperatures are compared with calculations based on the model using co-located radiosondes. Comparisons of perceptible water vapor retrieved from the radiometer with integrated soundings and co-located GPS retrievals are presented. The three water vapor sensing systems are shown to agree to within about 1 mm.

  5. Pervasive sensing

    Science.gov (United States)

    Nagel, David J.

    2000-11-01

    The coordinated exploitation of modern communication, micro- sensor and computer technologies makes it possible to give global reach to our senses. Web-cameras for vision, web- microphones for hearing and web-'noses' for smelling, plus the abilities to sense many factors we cannot ordinarily perceive, are either available or will be soon. Applications include (1) determination of weather and environmental conditions on dense grids or over large areas, (2) monitoring of energy usage in buildings, (3) sensing the condition of hardware in electrical power distribution and information systems, (4) improving process control and other manufacturing, (5) development of intelligent terrestrial, marine, aeronautical and space transportation systems, (6) managing the continuum of routine security monitoring, diverse crises and military actions, and (7) medicine, notably the monitoring of the physiology and living conditions of individuals. Some of the emerging capabilities, such as the ability to measure remotely the conditions inside of people in real time, raise interesting social concerns centered on privacy issues. Methods for sensor data fusion and designs for human-computer interfaces are both crucial for the full realization of the potential of pervasive sensing. Computer-generated virtual reality, augmented with real-time sensor data, should be an effective means for presenting information from distributed sensors.

  6. Study on acetone of iodinated reaction%“丙酮碘化”实验的探究

    Institute of Scientific and Technical Information of China (English)

    陈芳; 张丽; 刘钰莹; 陆江林

    2011-01-01

    对物理化学实验教学中的典型动力学实验-丙酮碘化进行了研究,探讨了实验测试波长的选择、碘溶液的适宜浓度范围及所用酸和丙酮的最佳浓度范围。%The physical chemistry experiment teaching of typical dynamic experiment-acetone of iodinated reaction were studied.Selection of the experimental wavelength,the appropriate concentration of iodine solution and the best acid and acetone concentration were discussed.

  7. Acetone-water complexes at MRCI level using localized orbitals: n ->pi* and pi ->pi* electronic transitions

    DEFF Research Database (Denmark)

    Hoyau, S.; Ben Amor, N.; Borini, Stefano

    2008-01-01

    The n -> pi* and pi -> pi* vertical electronic transitions of acetone with two and four H2O which correspond to a first solvation shell are considered. By using localized orbitals, and thanks to the MRCI approach which permits to know the wave function, the role of the various solvent molecules...... is analysed in details. Distinguishing the solvent molecules allows one to consider them at different calculation levels. The methodology is to compare the spectra obtained with four H2O, with two H2O either in the acetone plane or in a perpendicular plane and when they are completely or partly frozen....

  8. BaFe{sub 12}O{sub 19} powder with high magnetization prepared by acetone-aided coprecipitation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hsuan-Fu, E-mail: hfyu@mail.tku.edu.tw

    2013-09-15

    BaFe{sub 12}O{sub 19} particles with high magnetization were produced using an acetone-aided coprecipitation process. An aqueous solution of iron and barium nitrates, in an Fe{sup 3+}/Ba{sup 2+} molar ratio of 12, was added in a stirred precipitation liquid medium composed of H{sub 2}O, CH{sub 3}(CO)CH{sub 3} and NH{sub 4}OH. After reacting metallic ions with ammonia, the precipitates were formed, centrifugally filtered, freeze dried and calcined. Effects of amount of the acetone in the precipitation liquid medium on the formation of crystalline BaFe{sub 12}O{sub 19} were investigated. The presence of acetone in the precipitation liquid medium can greatly promote formation of the crystalline BaFe{sub 12}O{sub 19} at temperature as low as 650 °C and can enhance magnetization of the derived particles. On the other hand, raising the calcination temperature can effectively accelerate development of crystallite morphology and magnetic characters of the barium hexaferrites. While the barium hexaferrite powder obtained without acetone additions and calcined at 1000 °C had magnetization (measured at 50 kOe; M(50 kOe)) of 63.5 emu/g, remanence magnetization (Mr) of 31.3 emu/g and coercivity (Hc) of 4.7 kOe, the single magnetic domain size BaFe{sub 12}O{sub 19} powder with M(50 kOe) of 70.6 emu/g, Mr of 34.4 emu/g and Hc of 3.7 kOe was produced at 1000 °C, using a precipitation liquid medium of 64 vol% acetone. - Highlights: • BaFe{sub 12}O{sub 19} with high magnetic characters was produced by an acetone-aided coprecipitation. • The effects of acetone addition in the precipitation on the formation of BaFe{sub 12}O{sub 19} were studied. • Acetone presence in the precipitation liquid medium promoted BaFe{sub 12}O{sub 19} formation at ≥650 °C. • BaFe{sub 12}O{sub 19} with M(50 kOe) of 70.6 emu/g, Mr of 34.4 emu/g and Hc of 3.7 kOe was obtained.

  9. Organic Vapour Sensing Properties of Area-Ordered and Size-Controlled Silicon Nanopillar

    Directory of Open Access Journals (Sweden)

    Wei Li

    2016-11-01

    Full Text Available Here, a silicon nanopillar array (Si-NPA was fabricated. It was studied as a room-temperature organic vapour sensor, and the ethanol and acetone gas sensing properties were detected with I-V curves. I-V curves show that these Si-NPA gas sensors are sensitive to ethanol and acetone organic vapours. The turn-on threshold voltage is about 0.5 V and the operating voltage is 3 V. With 1% ethanol gas vapour, the response time is 5 s, and the recovery time is 15 s. Furthermore, an evaluation of the gas sensor stability for Si-NPA was performed. The gas stability results are acceptable for practical detections. These excellent sensing characteristics can mainly be attributed to the change of the overall dielectric constant of Si-NPA caused by the physisorption of gas molecules on the pillars, and the filling of the gas vapour in the voids.

  10. Organic Vapour Sensing Properties of Area-Ordered and Size-Controlled Silicon Nanopillar.

    Science.gov (United States)

    Li, Wei; Feng, Zhilin; Dai, Enwen; Xu, Jie; Bai, Gang

    2016-11-09

    Here, a silicon nanopillar array (Si-NPA) was fabricated. It was studied as a room-temperature organic vapour sensor, and the ethanol and acetone gas sensing properties were detected with I-V curves. I-V curves show that these Si-NPA gas sensors are sensitive to ethanol and acetone organic vapours. The turn-on threshold voltage is about 0.5 V and the operating voltage is 3 V. With 1% ethanol gas vapour, the response time is 5 s, and the recovery time is 15 s. Furthermore, an evaluation of the gas sensor stability for Si-NPA was performed. The gas stability results are acceptable for practical detections. These excellent sensing characteristics can mainly be attributed to the change of the overall dielectric constant of Si-NPA caused by the physisorption of gas molecules on the pillars, and the filling of the gas vapour in the voids.

  11. Acetone photolysis at 248 nm revisited: pressure dependence of the CO and CO2 quantum yields.

    Science.gov (United States)

    Somnitz, H; Ufer, T; Zellner, R

    2009-10-14

    Pressure dependent CO and CO2 quantum yields in the laser pulse photolysis of acetone at 248 nm and T = 298 K have been measured directly using quantitative infrared diode laser absorption. The experiments cover the pressure range from 50 to 900 mbar. It is found that the quantum yields show a significant dependence on total pressure, with Phi(CO) decreasing from around 0.5 at 20 mbar to approximately 0.3 at 900 mbar. The corresponding CO2 yields as observed when O2 exists in the reaction mixture, exhibit exactly the opposite behaviour. For the sum of both a value of 1.05(-0.05)(+0.02) independent of pressure is obtained, showing that the sum of (Phi(CO) + Phi(CO2)) is a measure for the primary quantum yield in the photolysis of acetone. In addition, CO quantum yields and corresponding pressure dependences were measured in experiments using different bath gases including He, Ar, Kr, SF6, and O2 as third body colliders. The theoretical framework in which we discuss these data is based on our previous findings that the pressure dependence of the CO yield is a consequence of a stepwise fragmentation mechanism during which acetone decomposes initially into methyl and a vibrationally 'hot' acetyl radical, with the latter being able to decompose promptly into methyl plus CO. The pressure dependence of the CO yield then originates from the second step and is modelled quantitatively via statistical dynamical calculations using a combination of RRKM theory with a time-dependent master equation (ME) approach. From a comparison of experiment with theory the amount of excess energy in the vibrationally hot acetyl radicals (E* approximately 65 kJ mol(-1)) as well as the characteristic collision parameters for interaction of acetyl with the different bath gases were derived. Values of 90, 280, 310, 545, 550 and 1800 cm(-1) for the average energy transferred per downward collision for the bath gases He, Ar, Kr, O2, N2, and SF6, respectively, are obtained. The calculations also

  12. Nanostructure Sensing and Transmission of Gas Data

    Science.gov (United States)

    Li, Jing (Inventor)

    2011-01-01

    A system for receiving, analyzing and communicating results of sensing chemical and/or physical parameter values, using wireless transmission of the data. Presence or absence of one or more of a group of selected chemicals in a gas or vapor is determined, using suitably functionalized carbon nanostructures that are exposed to the gas. One or more physical parameter values, such as temperature, vapor pressure, relative humidity and distance from a reference location, are also sensed for the gas, using nanostructures and/or microstructures. All parameter values are transmitted wirelessly to a data processing site or to a control site, using an interleaving pattern for data received from different sensor groups, using I.E.E.E. 802.11 or 802.15 protocol, for example. Methods for estimating chemical concentration are discussed.

  13. Millimeter-wave Radiometer for High Sensitivity Water Vapor Profiling in Arid Regions

    Energy Technology Data Exchange (ETDEWEB)

    Pazmany, Andrew

    2006-11-09

    Abstract - ProSensing Inc. has developed a G-band (183 GHz) water Vapor Radiometer (GVR) for long-term, unattended measurements of low concentrations of atmospheric water vapor and liquid water. Precipitable water vapor and liquid water path are estimated from zenith brightness temperatures measured from four double-sideband receiver channels, centered at 183.31 1, 3 and 7, and 14 GHz. A prototype ground-based version of the instrument was deployed at the DOE ARM program?s North Slope of Alaska site near Barrow AK in April 2005, where it collected data continuously for one year. A compact, airborne version of this instrument, packaged to operate from a standard 2-D PMS probe canister, has been tested on the ground and is scheduled for test flights in the summer of 2006. This paper presents design details, laboratory test results and examples of retrieved precipitable water vapor and liquid water path from measured brightness temperature data.

  14. Estimated vapor pressure for WTP process streams

    Energy Technology Data Exchange (ETDEWEB)

    Pike, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-01-01

    Design assumptions during the vacuum refill phase of the Pulsed Jet Mixers (PJMs) in the Hanford Waste Treatment and Immobilization Plant (WTP) equate the vapor pressure of all process streams to that of water when calculating the temperature at which the vacuum refill is reduced or eliminated. WTP design authority asked the authors to assess this assumption by performing calculations on proposed feed slurries to calculate the vapor pressure as a function of temperature. The vapor pressure was estimated for each WTP waste group. The vapor pressure suppression caused by dissolved solids is much greater than the increase caused by organic components such that the vapor pressure for all of the waste group compositions is less than that of pure water. The vapor pressure for each group at 145°F ranges from 81% to 98% of the vapor pressure of water. If desired, the PJM could be operated at higher temperatures for waste groups with high dissolved solids that suppress vapor pressure. The SO4 group with the highest vapor pressure suppression could be operated up to 153°F before reaching the same vapor pressure of water at 145°F. However, most groups would reach equivalent vapor pressure at 147 to 148°F. If any of these waste streams are diluted, the vapor pressure can exceed the vapor pressure of water at mass dilution ratios greater than 10, but the overall effect is less than 0.5%.

  15. Perovskite-type Mixed Oxides Catalyst for Complete Oxidation of Acetone

    Institute of Scientific and Technical Information of China (English)

    DUAN; ZhiYing

    2001-01-01

    The catalytic oxidation of VOCs (volatile organic compounds) is an attractive subject in the field of environmental protection now. Furthermore, most countries have made out regulations m controlling the maximum content of VOCs in some places. Presently, the leading way of domestic and foreign means to eliminate VOCs is to completely oxidize VOCs into carbon dioxide and water in presence of noble metal catalyst. But noble metal is expensive for lack of resource[2]. So it is insistent to research a low-cost catalyst for removal of VOCs. In this work, we have used some base metals (such as La, Sr, Ce, Ni, Cu) to synthesize mixed oxides catalyst supported on γ-A12O3. We have investigated the catalytic properties in the complete oxidation of acetone over the catalyst prepared and achieved an exciting result.……

  16. Theoretical Studies on the Iodine-catalyzed Nucleophilic Addition of Acetone with Five-membered Heterocycles

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-hua; LI Li; CHEN Xue-song

    2008-01-01

    The iodine-catalyzed nucleophilic addition reactions of pyrrole,furan,or thiophene with acetone were studied in gas and solvent by the density functional theory at the level of Lan12DZ*,It was seen that the halogen bond between iodine and carbonyl oxygen appeared to have an important catalytic effect on such reactions,and the first iodine molecule maximally diminished the barrier height by 41 kJ/mol,while the second iodine molecule could not improve such reactions largely,It was concluded that the C2-addition was generally more favorable than the C3-addition for the three heterocycles;however,iodine considerably more effectively catalyzed the C3-addition than the C2-addition for pyrrole,It was also revealed by PCM calculation that the iodine-catalyzed nucleophilic additions occurred more easily in solvent than in gas,which explained the experiment performed by Bandgar et al..

  17. Perovskite-type Mixed Oxides Catalyst for Complete Oxidation of Acetone

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ The catalytic oxidation of VOCs (volatile organic compounds) is an attractive subject in the field of environmental protection now. Furthermore, most countries have made out regulations m controlling the maximum content of VOCs in some places. Presently, the leading way of domestic and foreign means to eliminate VOCs is to completely oxidize VOCs into carbon dioxide and water in presence of noble metal catalyst. But noble metal is expensive for lack of resource[2]. So it is insistent to research a low-cost catalyst for removal of VOCs. In this work, we have used some base metals (such as La, Sr, Ce, Ni, Cu) to synthesize mixed oxides catalyst supported on γ-A12O3. We have investigated the catalytic properties in the complete oxidation of acetone over the catalyst prepared and achieved an exciting result.

  18. 1,3-Di-1-adamantylimidazolium (phthalocyaninatolithium(I acetone hemisolvate monohydrate

    Directory of Open Access Journals (Sweden)

    David A Grossie

    2009-01-01

    Full Text Available The asymmetric unit of the title compound, (C23H33N2[Li(C32H16N8]·0.5C3H6O·H2O, consists of two symmetry-unrelated lithium phthalocyanine (LiPc− half-anions, centered at (1,0,0 and (0,{script{1over 2}},0, respectively, the bis(adamantylimidazolium cation (BAI+, occupying a general site, an acetone molecule, disordered about the inversion centre at (0, {script{1over 2}}, {script{1over 2}} and a water molecule at a general site. The LiPc− anions pack in a stepped pattern enclosing the bis(adamantylimidazolium cation. Attractions between the anion and cation are mediated by a water molecule which forms O—H...N hydrogen bonds. In addition, two C—H...O interactions are seen.

  19. Continuous acetone-butanol-ethanol production by corn stalk immobilized cells.

    Science.gov (United States)

    Zhang, Yuedong; Ma, Yujiu; Yang, Fangxiao; Zhang, Chunhui

    2009-08-01

    Corn stalk was used as a support to immobilize Clostridia beijerinckii ATCC 55025 in the fermentation process of acetone, butanol, and ethanol production. The effect of the dilution rate on solvent production was examined in a steady-state 20-day continuous flow operation. The maximum total solvent concentration of 8.99 g l(-1) was obtained at a dilution rate of 0.2 h(-1). Increasing the dilution rate between 0.2 and 1.0 h(-1) resulted in an increased solvent productivity, and the highest solvent productivity was obtained at 5.06 g l(-1) h(-1) with a dilution rate of 1 h(-1). The maximum solvent yield from glucose of 0.32 g g(-1) was observed at 0.25 h(-1). The cell adsorption and morphology change during the growth on corn stalk support were examined by the SEM.

  20. Studies on Acetone Powder and Purified Rhus Laccase Immobilized on Zirconium Chloride for Oxidation of Phenols

    Directory of Open Access Journals (Sweden)

    Rong Lu

    2012-01-01

    Full Text Available Rhus laccase was isolated and purified from acetone powder obtained from the exudates of Chinese lacquer trees (Rhus vernicifera from the Jianshi region, Hubei province of China. There are two blue bands appearing on CM-sephadex C-50 chromatography column, and each band corresponding to Rhus laccase 1 and 2, the former being the major constituent, and each had an average molecular weight of approximately 110 kDa. The purified and crude Rhus laccases were immobilized on zirconium chloride in ammonium chloride solution, and the kinetic properties of free and immobilized Rhus laccase, such as activity, molecular weight, optimum pH, and thermostability, were examined. In addition, the behaviors on catalytic oxidation of phenols also were conducted.

  1. ACETONE REMOVAL AND BIOELECTRICITY GENERATION IN DUAL CHAMBER MICROBIAL FUEL CELL

    Directory of Open Access Journals (Sweden)

    Mostafa Rahimnejad

    2012-01-01

    Full Text Available Synthetic waste water contain organic compound can be oxidized in an anaerobic conditions in microbial fuel cell while biodegradation of Chemical Oxygen Demand (COD takes place under anaerobic condition in anode compartment. The microorganisms for biological treatment of the organic matter were obtained from a UASFB bioreactor. In the treatment of waste water, ones COD was removed the current and power was generated and record. Also polarization curve was obtained. In cathode compartment ferocynide and potassium permanganate with several concentration were add for enhancement of proton oxidation. The performance of MFC for maximum current and power generation were obtained with 300 µM L-1 potassium permanganate as oxidizers agent. Maximum generated power and current densities were 22 mW/m2 and 70 mA/m2, respectively. Active microorganisms used acetone as electron donors and COD removal was 69% at the end of process.

  2. Poly[[aquadi-μ3-malonato-hexaphenylditin(IV] acetone solvate

    Directory of Open Access Journals (Sweden)

    Yip Foo Win

    2010-06-01

    Full Text Available The asymmetric unit of the title polymeric complex, {[Sn2=(C6H56(C3H2O4(H2O]·C3H6O}n, comprises of two Sn cations, one malonate anion and a non-coordinating acetone solvent molecule. Both crystallographically independent Sn cations are five-coordinated by two O and three C atoms in a distorted trigonal-bipyrimidal geometry. One of the Sn cations is bridged by the malonate units, affording polymeric chains which run along [001]. Weak intramolecular C—H...π interactions stabilize the molecular structure. In the crystal structure, adjacent chains are interconnected by intermolecular O—H...O and C—H...O hydrogen bonds into a three-dimensional supramolecular structure. A weak intermolecular C—H...π interaction is also observed.

  3. Poly[[aquadi-μ(3)-malonato-hexaphenyl-ditin(IV)] acetone solvate].

    Science.gov (United States)

    Win, Yip Foo; Teoh, Siang Guan; Vikneswaran, M R; Goh, Jia Hao; Fun, Hoong-Kun

    2010-05-22

    The asymmetric unit of the title polymeric complex, {[Sn(2)=(C(6)H(5))(6)(C(3)H(2)O(4))(H(2)O)]·C(3)H(6)O}(n), comprises of two Sn cations, one malonate anion and a non-coordinating acetone solvent mol-ecule. Both crystallographically independent Sn cations are five-coordinated by two O and three C atoms in a distorted trigonal-bipyrimidal geometry. One of the Sn cations is bridged by the malonate units, affording polymeric chains which run along [001]. Weak intra-molecular C-H⋯π inter-actions stabilize the mol-ecular structure. In the crystal structure, adjacent chains are inter-connected by inter-molecular O-H⋯O and C-H⋯O hydrogen bonds into a three-dimensional supra-molecular structure. A weak inter-molecular C-H⋯π inter-action is also observed.

  4. Numerical simulation for isothermal dendritic growth of succinonitrile-acetone alloy

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi; CHEN Chang-le; HAO Li-mei

    2008-01-01

    Numerical simulation based on phase field method was developed to describe the solidification of two-dimensional isothermal binary alloys.The evolution of the interface morphology was shown and the effects of phase field parameters were formulated for succinonitrile-acetone alloy.The results indicate that an anti-trapping current (ATC) can suppress many trapped molten packets,which is caused by the thickened interface.With increasing the anisotropy value from 0 to 0.05,a small circular seed grows to develope secondary dendritic,dendritic tip velocity increases monotonically,and the solute accumulation of solid/liquid interface is diminished distinctly.Furthermore,with the increase of the coupling parameter value,the interface becomes unstable and the side branches of crystals appear and grow gradually.

  5. High Efficiency Pulse Acetone Liquid Raman Laser Using DCM Fluorescent Dye as the Enhancement Medium

    Institute of Scientific and Technical Information of China (English)

    CHENG Andrew Yuk-Sun; YANG Jing-Guo; CHAN Mau-Hing

    2006-01-01

    Pumped by a frequency-doubled Nd:YAG laser, 10-Hz repetition rate, 320-mJ pump energy, and 5.1-ns pulse width, a liquid Raman laser using acetone as the Raman shifting medium has been established. The residual pump laser pulse and the generated Stokes pulse are directed to a DCM dye cell for energy enhancement of the Stokes pulse. The Raman laser system is capable to produce a laser pulse at wavelength 630 nm, with single pulse energy of 120 mJ, peak power of 70 MW and an average power of 1200 mW. The energy conversion efficiency is 37.5%, or equivalently a quantum efficiency of 44.5%.

  6. Pressure swing adsorption modeling of acetone and toluene on activated carbon

    Institute of Scientific and Technical Information of China (English)

    唐琳; 李立清; 邢俊东; 刘峥; 姚小龙

    2013-01-01

    A five steps pressure swing adsorption process was designed for acetone and toluene mixtures separation and recovery. Dynamic distributions of gas phase content and temperature were investigated. Based on the theory of Soret and Dufour, a non-isothermal mathematical model was developed to simulate the PSA process. Effects of heat and mass transfer coefficients were studied. The coupled Soret and Dufour effects were also evaluated. It is found that the heat transfer coefficient has little effect on mass transfer in adsorption stage. However, it has some impacts in desorption stage. The maximum value of C/C0 increases by about 25% as heat transfer coefficient decreases. The temperature variation is less than 0.05 K with the change of mass transfer coefficient, so that the effect of mass transfer coefficient on heat transfer can be ignored. It is also concluded that the Soret and Dufour coupled effects are not obvious in pressure swing adsorption compared with fixed-bed adsorption.

  7. Disentangling Multichannel Photodissociation Dynamics in Acetone by Time-Resolved Photoelectron-Photoion Coincidence Spectroscopy.

    Science.gov (United States)

    Maierhofer, Paul; Bainschab, Markus; Thaler, Bernhard; Heim, Pascal; Ernst, Wolfgang E; Koch, Markus

    2016-08-18

    For the investigation of photoinduced dynamics in molecules with time-resolved pump-probe photoionization spectroscopy, it is essential to obtain unequivocal information about the fragmentation behavior induced by the laser pulses. We present time-resolved photoelectron-photoion coincidence (PEPICO) experiments to investigate the excited-state dynamics of isolated acetone molecules triggered by two-photon (269 nm) excitation. In the complex situation of different relaxation pathways, we unambiguously identify three distinct pump-probe ionization channels. The high selectivity of PEPICO detection allows us to observe the fragmentation behavior and to follow the time evolution of each channel separately. For channels leading to fragment ions, we quantitatively obtain the fragment-to-parent branching ratio and are able to determine experimentally whether dissociation occurs in the neutral molecule or in the parent ion. These results highlight the importance of coincidence detection for the interpretation of time-resolved photochemical relaxation and dissociation studies if multiple pathways are present.

  8. Final OSWER Vapor Intrusion Guidance

    Science.gov (United States)

    EPA is preparing to finalize its guidance on assessing and addressing vapor intrusion, which is defined as migration of volatile constituents from contaminated media in the subsurface (soil or groundwater) into the indoor environment. In November 2002, EPA issued draft guidance o...

  9. Simple Chemical Vapor Deposition Experiment

    Science.gov (United States)

    Pedersen, Henrik

    2014-01-01

    Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

  10. Hydrazine vapor inactivates Bacillus spores

    Science.gov (United States)

    Schubert, Wayne W.; Engler, Diane L.; Beaudet, Robert A.

    2016-05-01

    NASA policy restricts the total number of bacterial spores that can remain on a spacecraft traveling to any planetary body which might harbor life or have evidence of past life. Hydrazine, N2H4, is commonly used as a propellant on spacecraft. Hydrazine as a liquid is known to inactivate bacterial spores. We have now verified that hydrazine vapor also inactivates bacterial spores. After Bacillus atrophaeus ATCC 9372 spores deposited on stainless steel coupons were exposed to saturated hydrazine vapor in closed containers, the spores were recovered from the coupons, serially diluted, pour plated and the surviving bacterial colonies were counted. The exposure times required to reduce the spore population by a factor of ten, known as the D-value, were 4.70 ± 0.50 h at 25 °C and 2.85 ± 0.13 h at 35 °C. These inactivation rates are short enough to ensure that the bioburden of the surfaces and volumes would be negligible after prolonged exposure to hydrazine vapor. Thus, all the propellant tubing and internal tank surfaces exposed to hydrazine vapor do not contribute to the total spore count.

  11. Does acetone react with HO2 in the upper-troposphere?

    Directory of Open Access Journals (Sweden)

    J. Lelieveld

    2010-07-01

    Full Text Available Recent theoretical calculations showed that reaction of HO2 with acetone (CH3C(OCH3 could be a potentially important sink for acetone and source for acetic acid in cold parts of the atmosphere (e.g. the tropopause region. The reaction HO2+CH3C(OCH3⇌(CH32C(OHOO (R1, R-1 was therefore studied experimentally at low-temperatures for the first time. HO2 was generated by pulsed laser photolysis, and converted by reaction with NO to OH for detection by laser induced fluorescence. Reduced yields of OH at T32C(OHOO at such temperatures. In contrast, no evidence for (R1 was observed at T>230 K, probably due to rapid thermal dissociation of the peroxy radical product back to reactants (R-1. The experimental data indicate that the rate coefficient for the forward reaction, k1(207 K, is larger than 1.6×10-12 cm3 molecule−1 s−1, in line with recent quantum mechanical calculations. In contrast, an upper limit for the equilibrium constant K1(T=k1(T/k-1(T of 7.8×1028exp(50.6 kJ mol-1/RT was obtained, considerably smaller than calculated from theory. Incorporation of these results into a global 3-D chemical model demonstrated that (R1 is neither a significant loss process for CH3C(OCH3 nor a significant source of acetic acid in the atmosphere.

  12. Acetone-butanol-ethanol production with high productivity using Clostridium acetobutylicum BKM19.

    Science.gov (United States)

    Jang, Yu-Sin; Malaviya, Alok; Lee, Sang Yup

    2013-06-01

    Conventional acetone-butanol-ethanol (ABE) fermentation is severely limited by low solvent titer and productivities. Thus, this study aims at developing an improved Clostridium acetobutylicum strain possessing enhanced ABE production capability followed by process optimization for high ABE productivity. Random mutagenesis of C. acetobutylicum PJC4BK was performed by screening cells on fluoroacetate plates to isolate a mutant strain, BKM19, which exhibited the total solvent production capability 30.5% higher than the parent strain. The BKM19 produced 32.5 g L(-1) of ABE (17.6 g L(-1) butanol, 10.5 g L(-1) ethanol, and 4.4 g L(-1) acetone) from 85.2 g L(-1) glucose in batch fermentation. A high cell density continuous ABE fermentation of the BKM19 in membrane cell-recycle bioreactor was studied and optimized for improved solvent volumetric productivity. Different dilution rates were examined to find the optimal condition giving highest butanol and ABE productivities. The maximum butanol and ABE productivities of 9.6 and 20.0 g L(-1)  h(-1) , respectively, could be achieved at the dilution rate of 0.85 h(-1) . Further cell recycling experiments were carried out with controlled cell-bleeding at two different bleeding rates. The maximum solvent productivities were obtained when the fermenter was operated at a dilution rate of 0.86 h(-1) with the bleeding rate of 0.04 h(-1) . Under the optimal operational condition, butanol and ABE could be produced with the volumetric productivities of 10.7 and 21.1 g L(-1)  h(-1) , and the yields of 0.17 and 0.34 g g(-1) , respectively. The obtained butanol and ABE volumetric productivities are the highest reported productivities obtained from all known-processes.

  13. Acetone-butanol-ethanol production from substandard and surplus dates by Egyptian native Clostridium strains.

    Science.gov (United States)

    Abd-Alla, Mohamed Hemida; Zohri, Abdel-Naser Ahmed; El-Enany, Abdel-Wahab Elsadek; Ali, Shimaa Mohamed

    2015-04-01

    One hundred and seven mesophilic isolates of Clostridium were isolated from agricultural soils cultivated with different plants in Assuit Governorate, Egypt. Eighty isolates (out of 107) showed the ability to produce ABE (Acetone, butanol and ethanol) on T6 medium ranging from 0.036 to 31.89 g/L. The highest numbers of ABE producing isolates were obtained from soil samples of potato contributing 27 isolates, followed by 18 isolates from wheat and 10 isolates from onion. On the other hand, there were three native isolates that produced ABE more than those produced by the reference isolate Clostridium acetobutylicum ATCC 824 (11.543 g/L). The three isolates were identified based on phenotypic and gene encoding 16S rRNA as Clostridium beijerinckii ASU10 (KF372577), Clostridium chauvoei ASU55 (KF372580) and Clostridium roseum ASU58 (KF372581). The highest ABE level from substandard and surplus dates was produced by C. beijerinckii ASU10 (24.07 g/L) comprising butanol 67.15% (16.16 g/L), acetone 30.73% (7.4 g/L) and ethanol 2.12% (0.51 g/L), while C. roseum ASU58 and C. chauvoei ASU55 produced ABE contributing 20.20 and 13.79 g/L, respectively. ABE production by C. acetobutylicum ATCC 824 was 15.01 g/L. This study proved that the native strains C. beijerinckii ASU10 and C. roseum ASU58 have high competitive efficacy on ABE production from economical substrate as substandard and surplus date fruits. Additionally, using this substrate without any nutritional components is considered to be a commercial substrate for desired ABE production.

  14. Acetones Removal with Fe Doped Titanium Nano Tube Catalysts Prepared from Slag Iron in Steel Plant.

    Science.gov (United States)

    Lin, Yu-Jung; Wen-ZhiCao; Chang, Chang-Tang

    2016-01-01

    TiO₂ has been studied most commonly because it has high stability, non-toxicity, high catalytic activity, and highly conductivity. Many studies have shown that TiO₂ would generate electron-hole pairs illuminated with UV and surround more energy than that before being illuminated. However, the surface area of TiO₂ is not large enough and the adsorption capacity is small. In this study, the titanium nano tube (TNT) catalysts were prepared to increase the surface area and adsorption capacity. The Fe-TNT was also prepared from slag iron since many slag iron cause waste treatment problems. In this study, the effect of Fe loading, including 0.77%, 1.13%, 2.24% and 4.50%, on acetone removal was also assessed since TNT doped with transitional or precious metals can be used to improve catalytic reaction efficiency. Furthermore, four kinds of VOCs concentration, including 250, 500, 1000 and 1500 ppm were tested. Four kinds of retention time, including 0.4, 0.8, 4.0 and 6.0 sec, and four kinds of dosage, including 0.15, 0.25, 0.30 and 0.45 g cm⁻³, were also assessed. In this study, the adsorption capacity of Fe-TNT was 18.8, 23.3, 28.9 and 32.6 mg g⁻¹ for acetone of 250, 500, 1000 and 1500 ppm, respectively. Four kinds of temperature, including 150, 200, 250 and 300 °C were tested in catalytic reaction system. The results showed removal efficiency increased with increasing temperature. The efficiency can be reached 95% under the conditions with the dosage higher than 0.3 g cm⁻³, temperature higher than 270 °C and retention time higher than 270 °C. Reaction efficiency was 20, 31, 41 and 96% at the temperature of 150, 200, 250 and 300 °C, respectively.

  15. Thermodynamic study of the solubility of ibuprofen in acetone and dichloromethane

    Directory of Open Access Journals (Sweden)

    Diana Marcela Aragón

    2010-06-01

    Full Text Available Thermodynamic functions, Gibbs energy, enthalpy and entropy for the solution processes of ibuprofen (IBP in acetone and dichloromethane (DCM were calculated from solubility values obtained at temperatures ranging from 293.15 K to 313.15 K. The respective thermodynamic functions for mixing and solvation processes as well as the activity coefficients for the solute were calculated. IBP solubility was high and proved similar in both solvents but was greater in DCM than acetone. In addition, the thermodynamic quantities for the transfer process of this drug from cyclohexane to the organic solvents were also calculated in order to estimate the contributions of hydrogen-bonds or of other dipolar interactions. The results were discussed in terms of solute-solvent interactions.As funções termodinâmicas, energia de Gibbs, entalpia e entropia dos processos de solução de ibuprofeno (IBP em acetona e em diclorometano (DCM foram calculadas a partir dos valores de solubilidade, obtidos em intervalos de temperatura de 293,15 K a 313,15 K. As funções termodinâmicas respectivas para os processos de mistura e solvatação e os coeficientes de atividade para o soluto também foram calculados. A solubilidade do IBP foi grande e semelhante em ambos os solventes, mas, maior em DCM do que em acetona. Em adição, as quantidades termodinâmicas relativas ao processo de transferência desse fármaco do cicloexano para os solventes orgânicos foram, também, calculadas com o objetivo de estimar as contribuições devidas às ligações de hidrogênio ou a outras interações dipolares. Os resultados foram discutidos nos termos das interações soluto-solvente.

  16. Reaction kinetics and critical phenomena: iodination of acetone in isobutyric acid + water near the consolute point.

    Science.gov (United States)

    Hu, Baichuan; Baird, James K

    2010-01-14

    The rate of iodination of acetone has been measured as a function of temperature in the binary solvent isobutyric acid (IBA) + water near the upper consolute point. The reaction mixture was prepared by the addition of acetone, iodine, and potassium iodide to IBA + water at its critical composition of 38.8 mass % IBA. The value of the critical temperature determined immediately after mixing was 25.43 degrees C. Aliquots were extracted from the mixture at regular intervals in order to follow the time course of the reaction. After dilution of the aliquot with water to quench the reaction, the concentration of triiodide ion was determined by the measurement of the optical density at a wavelength of 565 nm. These measurements showed that the kinetics were zeroth order. When at the end of 24 h the reaction had come to equilibrium, the critical temperature was determined again and found to be 24.83 degrees C. An Arrhenius plot of the temperature dependence of the observed rate constant, k(obs), was linear over the temperature range 27.00-38.00 degrees C, but between 25.43 and 27.00 degrees C, the values of k(obs) fell below the extrapolation of the Arrhenius line. This behavior is evidence in support of critical slowing down. Our experimental method and results are significant in three ways: (1) In contrast to in situ measurements of optical density, the determination of the optical density of diluted aliquots avoided any interference from critical opalescence. (2) The measured reaction rate exhibited critical slowing down. (3) The rate law was pseudo zeroth order both inside and outside the critical region, indicating that the reaction mechanism was unaffected by the presence of the critical point.

  17. FABRICATION OF DIAMOND TUBES IN BIAS-ENHANCED HOT-FILAMENT CHEMICAL VAPOR DEPOSITION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    CHEN Ming; MA Yuping; XIANG Daohui; SUN Fanghong

    2007-01-01

    Deposition of diamond thin films on tungsten wire Substrate with the gas mixture of acetone and hydrogen by using bias-enhanced hol filament chemical vapor deposition (CVD) with the tantalum wires being optimized arranged is investigated. The self-supported diamond tubes are obtained by etching away the tungsten Substrates. The quality of the diamond film before and after the removal of Substrates is observed by scanning electron microscope (SEM) and Raman spectrum. The results show that the cylindrical diamond tubes with good quality and uniform thickness are obtained on tungsten wires by using bias enhanced hot filament CVD. The compressive stress in diamond film formed during the deposition is released after the Substrate etches away by mixture of H202 and NH4OH. There is no residual stress in diamond tube after Substrate removal.

  18. Stable isotopes in atmospheric water vapor and applications to the hydrologic cycle

    Science.gov (United States)

    Galewsky, Joseph; Steen-Larsen, Hans Christian; Field, Robert D.; Worden, John; Risi, Camille; Schneider, Matthias

    2016-12-01

    The measurement and simulation of water vapor isotopic composition has matured rapidly over the last decade, with long-term data sets and comprehensive modeling capabilities now available. Theories for water vapor isotopic composition have been developed by extending the theories that have been used for the isotopic composition of precipitation to include a more nuanced understanding of evaporation, large-scale mixing, deep convection, and kinetic fractionation. The technologies for in situ and remote sensing measurements of water vapor isotopic composition have developed especially rapidly over the last decade, with discrete water vapor sampling methods, based on mass spectroscopy, giving way to laser spectroscopic methods and satellite- and ground-based infrared absorption techniques. The simulation of water vapor isotopic composition has evolved from General Circulation Model (GCM) methods for simulating precipitation isotopic composition to sophisticated isotope-enabled microphysics schemes using higher-order moments for water and ice size distributions. The incorporation of isotopes into GCMs has enabled more detailed diagnostics of the water cycle and has led to improvements in its simulation. The combination of improved measurement and modeling of water vapor isotopic composition opens the door to new advances in our understanding of the atmospheric water cycle, in processes ranging from the marine boundary layer, through deep convection and tropospheric mixing, and into the water cycle of the stratosphere. Finally, studies of the processes governing modern water vapor isotopic composition provide an improved framework for the interpretation of paleoclimate proxy records of the hydrological cycle.

  19. Boiler for generating high quality vapor

    Science.gov (United States)

    Gray, V. H.; Marto, P. J.; Joslyn, A. W.

    1972-01-01

    Boiler supplies vapor for use in turbines by imparting a high angular velocity to the liquid annulus in heated rotating drum. Drum boiler provides a sharp interface between boiling liquid and vapor, thereby, inhibiting the formation of unwanted liquid droplets.

  20. Conversational sensing

    Science.gov (United States)

    Preece, Alun; Gwilliams, Chris; Parizas, Christos; Pizzocaro, Diego; Bakdash, Jonathan Z.; Braines, Dave

    2014-05-01

    Recent developments in sensing technologies, mobile devices and context-aware user interfaces have made it pos- sible to represent information fusion and situational awareness for Intelligence, Surveillance and Reconnaissance (ISR) activities as a conversational process among actors at or near the tactical edges of a network. Motivated by use cases in the domain of Company Intelligence Support Team (CoIST) tasks, this paper presents an approach to information collection, fusion and sense-making based on the use of natural language (NL) and controlled nat- ural language (CNL) to support richer forms of human-machine interaction. The approach uses a conversational protocol to facilitate a ow of collaborative messages from NL to CNL and back again in support of interactions such as: turning eyewitness reports from human observers into actionable information (from both soldier and civilian sources); fusing information from humans and physical sensors (with associated quality metadata); and assisting human analysts to make the best use of available sensing assets in an area of interest (governed by man- agement and security policies). CNL is used as a common formal knowledge representation for both machine and human agents to support reasoning, semantic information fusion and generation of rationale for inferences, in ways that remain transparent to human users. Examples are provided of various alternative styles for user feedback, including NL, CNL and graphical feedback. A pilot experiment with human subjects shows that a prototype conversational agent is able to gather usable CNL information from untrained human subjects.

  1. Effects of Bronsted acidity in the mechanism of selective oxidation of propane to acetone on CaY zeolite at room temperature.

    NARCIS (Netherlands)

    Xu, Jiang; Mojet, Barbara L.; Ommen, van Jan G.; Lefferts, Leon

    2005-01-01

    The importance of Brønsted acid sites for partial oxidation of propane to acetone in CaY was investigated by in situ FTIR spectroscopy. With an increasing number of protons in Ca-Y, Volcano plots were observed for (1) amount of adsorbed propane; (2) initial acetone formation rate; (3) total amount o

  2. 40 CFR 721.6660 - Polymer of alkanepolyol and poly-alkyl-poly-iso-cyan-ato-car-bo-mo-no-cycle, acetone oxime...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of alkanepolyol and poly-alkyl-poly-iso-cyan-ato-car-bo-mo-no-cycle, acetone oxime-blocked (generic name). 721.6660 Section 721.6660... Polymer of alkanepolyol and poly-alkyl-poly-iso-cyan-ato-car-bo-mo-no-cycle, acetone...

  3. COMPARATIVE STUDY OF ANTHELMINTIC ACTIVITY BETWEEN ACETONE AND ETHANOLIC STEM BARK EXTRACTS OF SPONDIAS PINNATA (LINN.F KURZ

    Directory of Open Access Journals (Sweden)

    Panda B.K

    2011-04-01

    Full Text Available Spondias Pinnata (Linn.F Kurz is found in tribal area of Mayurbhanj district and extensively used traditionally by the tribal people as Anthelmintic, Anti-inflammatory, Regulate menstruation, Anti-pyretic, Anti-tumor and Anti-bacterial activity1-6. The present study is attempted to explore the anthelmintic activity of acetone and ethanol extract of bark of plant Spondias Pinnata in a comparative study. The various doses of acetone and ethanol extracts were evaluated for their anthelmintic activities on adult Indian earthworms, Pheretima postuma. All extracts of both the solvents were able to show anthelmintic activity at (10, 25, 50 and 100 mg/ml concentration. The activities are well comparable with standard drugs, Piperazine citrate and Albendazole (10 mg/ml.All the doses of acetone and ethanol extract of Spondias Pinnata showed better anthelmintic activities than the standard drugs. When the dose of extract is increased, a gradual increase in anthelmintic activity was observed. Ethanol extract showed better anthelmintic activity in comparison to the acetone extract of Spondias Pinnata. The data was verified as statistically significance by using ANOVA at 5% level of significance (P< 0.05.

  4. Phenolic content, antioxidant and antifungal activities of acetonic, ethanolic and petroleum ether extracts of Hypericum perforatum L.

    Directory of Open Access Journals (Sweden)

    Mašković Pavle Z.

    2011-01-01

    Full Text Available The objective of this study was to evaluate antifungal and antioxidant activities of Hypericum perforatum L. extracts against the growth of certain fungi. The ethanolic, acetonic and petroleum ether extracts of the plant were evaluated for phenols, flavonoids and non-flavonoids. The highest amounts of phenols (17.6 mg EPC/g dry extract and flavonoids (16.85 mg EPC/g dry extract were found in the acetonic extract. The highest inhibitory effect on the growth of Penicillium canescens, Fusarium oxysporum, Alternaria alternata, Aspergillus glaucus and Phialophora fastigiata by the disk diffusion method was exhibited by the ethanolic extract at the concentration of 25 mg/disk. The minimum inhibitory concentration (MIC of the ethanolic and petroleum ether extracts was 20 mg/mL. The acetonic extract did not affect the growth of the tested fungi. Antioxidant activity was assessed by determining 1,1-Diphenyl-2-picryl-hydrazyl-hydrate (DPPH free radical scavenging activity. The results showed that the ethanolic extract of Hypericum perforatum L. possesses antioxidant activity. The IC50 values, defined as the concentration of the test sample leading to 50% reduction of the free radical concentration, determined for each measurement were <7.8125, 105.9, 5.99 and 12.77 μg/ml for the ethanolic extract, the acetonic extract, ascorbic acid and BHT, respectively, for DPPH free radical scavenging activity.

  5. Utilisation of saccharides in extruded domestic organic waste by Clostridium acetobutylicum ATCC 824 for production of acetone, butanol and ethanol

    NARCIS (Netherlands)

    Lopez-Contreras, A.M.; Claassen, P.A.; Mooibroek, H.; Vos, de W.M.

    2000-01-01

    Domestic organic waste (DOW) collected in The Netherlands was analysed and used as substrate for acetone, butanol and ethanol (ABE) production. Two different samples of DOW, referred to as fresh DOW and dried DOW, were treated by extrusion in order to expand the polymer fibres present and to obtain

  6. High acetone concentrations throughout the 0-12 km altitude range over the tropical rainforest in Surinam

    NARCIS (Netherlands)

    Poschl, U; Williams, J; Hoor, P; Fischer, H; Crutzen, PJ; Warneke, C; Holzinger, R; Hansel, A; Jordan, A; Lindinger, W; Scheeren, HA; Peters, W; Lelieveld, J

    2001-01-01

    Airborne measurements of acetone were performed over the tropical rainforest in Surinam (2 degrees -7 degrees N, 54 degrees -58 degrees W, 0-12 km altitude) during the LBA-CLAIRE campaign in March 1998, using a novel proton transfer reaction mass spectrometer (PTR-MS) that enables the on-line monito

  7. Modification of an acetone-sodium dodecyl sulfate disruption method for cellular protein extraction from neuropathogenic Clostridium botulinum

    Science.gov (United States)

    An acetone-sodium dodecyl sulfate (SDS) disruption method was used for the extraction of cellular proteins from neurotoxigenic Clostridium botulinum. The amount of protein extracted per gram of dry weight and the protein profile as revealed by polyacrylamide gel electrophoresis (PAGE) was comparabl...

  8. Acetalization of acetone with glycerol catalyzed by niobium-aluminum mixed oxides synthesized by a sol–gel process

    NARCIS (Netherlands)

    Rodrigues, Raphael; Mandelli, Dalmo; Gonçalves, Norberto S.; Pescarmona, Paolo P.; Carvalho, Wagner A.

    2016-01-01

    Niobium-aluminum-based catalysts were synthesized by a sol–gel process and successfully applied to the reaction of acetalization of acetone with glycerol yielding 2,2-dimethyl-1,3-dioxolane-4-methanol (solketal) and 2,2-dimethyl-1,3-dioxan-5-ol. The synthesis procedure was developed using high-throu

  9. Development of vapor deposited thin films for bio-microsystems

    Science.gov (United States)

    Popat, Ketul Chandrakant

    Increasing demands for more biocompatible and sophisticated bio-microsystems in recent years has led to the development of a new technology called BioMEMS (biological micro-electro-mechanical systems). The foundation of this technology is the same as that of the traditional field of IC (integrated circuits), but an emphasis on developing new diagnostic and therapeutic modalities. Micro- and nano-fabrication techniques are currently being used to develop implants that can record, sense, stimulate and deliver to biological systems. Micromachined substrates can provide unique advantages over traditional implantable devices in terms of their ability to control surface micro-architecture, topography and feature size in micron and nano sizes. However, as BioMEMS technology is rapidly being developed, the practical use of these bio-microsystems is limited due to the inability to effectively interface with the biological system in non-immunogenic and stable manner. This is one of the most important considerations, and hence it is useful to focus on the fundamental scientific issues relating to material science, surface chemistry and immunology of silicon based bio-microsystems. This results in development of biomolecular interfaces that are compatible with both microfabrication processing and biological systems. The overall thrust of this research is to develop, characterize and integrate vapor deposited thin films with bio-microsystems in a manner that it is both reproducible and fully integrated with existing technologies. The main strategy is to use silane coatings precursor coatings on which poly (ethylene glycol) (PEG) will be coated in vapor phase. Silane has been coated user vapor phase, but its chemical and biological characterization and stability of the films under physiological conditions has not been investigated for biological applications. PEG has been coated in solution phase on silicon surface. However, it has not been coated under vapor phase. Here we are

  10. Chemicapacitors as a versatile platform for miniature gas and vapor sensors

    Science.gov (United States)

    Blue, Robert; Uttamchandani, Deepak

    2017-02-01

    Recent years have seen the rapid growth in the need for sensors throughout all areas of society including environmental sensing, health-care, public safety and manufacturing quality control. To meet this diverse need, sensors have to evolve from specialized and bespoke systems to miniaturized, low-power, low-cost (almost disposable) ubiquitous platforms. A technology that has been developed which gives a route to meet these challenges is the chemicapacitor sensor. To date the commercialization of these sensors has largely been restricted to humidity sensing, but in this review we examine the progress over recent years to expand this sensing technology to a wide range of gases and vapors. From sensors interrogated with laboratory instrumentation, chemicapacitor sensors have evolved into miniaturized units integrated with low power readout electronics that can selectively detect target molecules to ppm and sub-ppm levels within vapor mixtures.

  11. Preparation and Characterization of Epoxy Resin Cross-Linked with High Wood Pyrolysis Bio-Oil Substitution by Acetone Pretreatment

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2017-03-01

    Full Text Available The use of cost effective solvents may be necessary to store wood pyrolysis bio-oil in order to stabilize and control its viscosity, but this part of the production system has not been explored. Conversely, any rise in viscosity during storage, that would occur without a solvent, will add variance to the production system and render it cost ineffective. The purpose of this study was to modify bio-oil with a common solvent and then react the bio-oil with an epoxy for bonding of wood without any loss in properties. The acetone pretreatment of the bio-oil/epoxy mixture was found to improve the cross-linking potential and substitution rate based on its mechanical, chemical, and thermal properties. Specifically, the bio-oil was blended with epoxy resin at weight ratios ranging from 2:1 to 1:5 and were then cured. A higher bio-oil substitution rate was found to lower the shear bond strength of the bio-oil/epoxy resins. However, when an acetone pretreatment was used, it was possible to replace the bio-oil by as much as 50% while satisfying usage requirements. Extraction of the bio-oil/epoxy mixture with four different solvents demonstrated an improvement in cross-linking after acetone pretreatment. ATR-FTIR analysis confirmed that the polymer achieved a higher cross-linked structure. DSC and TGA curves showed improved thermal stability with the addition of the acetone pretreatment. UV-Vis characterization showed that some functional groups of the bio-oil to epoxy system were unreacted. Finally, when the resin mixture was utilized to bond wood, the acetone pretreatment coupled with precise tuning of the bio-oil:epoxy ratio was an effective method to control cross-linking while ensuring acceptable bond strength.

  12. Reformation for production process of acetone cyanohydrin%丙酮氰醇生产工艺改造

    Institute of Scientific and Technical Information of China (English)

    赵永亮; 李晓光; 钱有程

    2013-01-01

    The production capacity of acetone cyanohydrin unit is 80 000 t/a,the consumption of raw acetone is 60 000 t/a,producing incineration wastewater 3 000 t/a. Because of acetone cyanohydrin production process backward, using inorganic alkali hydroxide as catalyst, the production process produced a large amount of sodium sulfate crystal impurity,device operation cycle was short,the crystallization cauldron cleaning for three days at a time, refining tower cleaning for five days at a time, causing high consumption of acetone and wastewater,so the production cost was high;highly toxic plant startup and shutdown for cleaning frequent operation, which cause safety problems. According to the existence problem, we put forward a new production process of acetone cyanohydrin using organic alkali as catalyst,which can bring numerous economic benefits.%丙酮氰醇装置生产能力为8万t/a,消耗原料丙酮6万t/a,产生焚烧废水3 000 t/a.因丙酮氰醇生产工艺落后,用无机碱氢氧化钠做催化剂,生产过程中产生大量硫酸钠晶体杂质,装置运行周期短,结晶釜3d清洗1次,精制塔5d清洗1次,造成原料丙酮、废水消耗偏高,产品生产成本高;剧毒装置开停车清洗操作频繁,安全隐患大.根据装置存在问题,提出生产丙酮氰醇生产用有机碱做催化剂,具有显著的经济效益和社会效益.

  13. In situ hydrogen, acetone, butanol, ethanol and microdiesel production by Clostridium acetobutylicum ATCC 824 from oleaginous fungal biomass.

    Science.gov (United States)

    Hassan, Elhagag Ahmed; Abd-Alla, Mohamed Hemida; Bagy, Magdy Mohamed Khalil; Morsy, Fatthy Mohamed

    2015-08-01

    An in situ batch fermentation technique was employed for biohydrogen, acetone, butanol, ethanol and microdiesel production from oleaginous fungal biomass using the anaerobic fermentative bacterium Clostridium acetobutylicum ATCC 824. Oleaginous fungal Cunninghamella echinulata biomass which has ability to accumulate up to 71% cellular lipid was used as the substrate carbon source. The maximum cumulative hydrogen by C. acetobutylicum ATCC 824 from crude C. echinulata biomass was 260 ml H2 l(-1), hydrogen production efficiency was 0.32 mol H2 mole(-1) glucose and the hydrogen production rate was 5.2 ml H2 h(-1). Subsequently, the produced acids (acetic and butyric acids) during acidogenesis phase are re-utilized by ABE-producing clostridia and converted into acetone, butanol, and ethanol. The total ABE produced by C. acetobutylicum ATCC 824 during batch fermentation was 3.6 g l(-1) from crude fungal biomass including acetone (1.05 g l(-1)), butanol (2.19 g l(-1)) and ethanol (0.36 g l(-1)). C. acetobutylicum ATCC 824 has ability to produce lipolytic enzymes with a specific activity 5.59 U/mg protein to hydrolyze ester containing substrates. The lipolytic potential of C. acetobutylicum ATCC 824 was used as a biocatalyst for a lipase transesterification process using the produced ethanol from ABE fermentation for microdiesel production. The fatty acid ethyl esters (microdiesel) generated from the lipase transesterification of crude C. echinulata dry mass was analyzed by GC/MS as 15.4% of total FAEEs. The gross energy content of biohydrogen, acetone, butanol, ethanol and biodiesel generated through C. acetobutylicum fermentation from crude C. echinulata dry mass was 3113.14 kJ mol(-1). These results suggest a possibility of integrating biohydrogen, acetone, butanol and ethanol production technology by C. acetobutylicum with microdiesel production from crude C. echinulata dry mass and therefore improve the feasibility and commercialization of bioenergy production.

  14. A path integral molecular dynamics study of the hyperfine coupling constants of the muoniated and hydrogenated acetone radicals

    Science.gov (United States)

    Oba, Yuki; Kawatsu, Tsutomu; Tachikawa, Masanori

    2016-08-01

    The on-the-fly ab initio density functional path integral molecular dynamics (PIMD) simulations, which can account for both the nuclear quantum effect and thermal effect, were carried out to evaluate the structures and "reduced" isotropic hyperfine coupling constants (HFCCs) for muoniated and hydrogenated acetone radicals (2-muoxy-2-propyl and 2-hydoxy-2-propyl) in vacuo. The reduced HFCC value from a simple geometry optimization calculation without both the nuclear quantum effect and thermal effect is -8.18 MHz, and that by standard ab initio molecular dynamics simulation with only the thermal effect and without the nuclear quantum effect is 0.33 MHz at 300 K, where these two methods cannot distinguish the difference between muoniated and hydrogenated acetone radicals. In contrast, the reduced HFCC value of the muoniated acetone radical by our PIMD simulation is 32.1 MHz, which is about 8 times larger than that for the hydrogenated radical of 3.97 MHz with the same level of calculation. We have found that the HFCC values are highly correlated with the local molecular structures; especially, the Mu—O bond length in the muoniated acetone radical is elongated due to the large nuclear quantum effect of the muon, which makes the expectation value of the HFCC larger. Although our PIMD result calculated in vacuo is about 4 times larger than the measured experimental value in aqueous solvent, the ratio of these HFCC values between muoniated and hydrogenated acetone radicals in vacuo is in reasonable agreement with the ratio of the experimental values in aqueous solvent (8.56 MHz and 0.9 MHz); the explicit presence of solvent molecules has a major effect on decreasing the reduced muon HFCC of in vacuo calculations for the quantitative reproduction.

  15. HORIZON SENSING

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Stolarczyk

    2003-03-18

    With the aid of a DOE grant (No. DE-FC26-01NT41050), Stolar Research Corporation (Stolar) developed the Horizon Sensor (HS) to distinguish between the different layers of a coal seam. Mounted on mining machine cutter drums, HS units can detect or sense the horizon between the coal seam and the roof and floor rock, providing the opportunity to accurately mine the section of the seam most desired. HS also enables accurate cutting of minimum height if that is the operator's objective. Often when cutting is done out-of-seam, the head-positioning function facilitates a fixed mining height to minimize dilution. With this technology, miners can still be at a remote location, yet cut only the clean coal, resulting in a much more efficient overall process. The objectives of this project were to demonstrate the feasibility of horizon sensing on mining machines and demonstrate that Horizon Sensing can allow coal to be cut cleaner and more efficiently. Stolar's primary goal was to develop the Horizon Sensor (HS) into an enabling technology for full or partial automation or ''agile mining''. This technical innovation (R&D 100 Award Winner) is quickly demonstrating improvements in productivity and miner safety at several prominent coal mines in the United States. In addition, the HS system can enable the cutting of cleaner coal. Stolar has driven the HS program on the philosophy that cutting cleaner coal means burning cleaner coal. The sensor, located inches from the cutting bits, is based upon the physics principles of a Resonant Microstrip Patch Antenna (RMPA). When it is in proximity of the rock-coal interface, the RMPA impedance varies depending on the thickness of uncut coal. The impedance is measured by the computer-controlled electronics and then sent by radio waves to the mining machine. The worker at the machine can read the data via a Graphical User Interface, displaying a color-coded image of the coal being cut, and direct the machine

  16. Altitude and Latitude Distribution of Atmospheric Aerosol and Water Vapor from the Narrow-Band Lunar Eclipse Photometry

    CERN Document Server

    Ugolnikov, Oleg S

    2007-01-01

    The work contains the description of two narrow IR-bands observational data of total lunar eclipse of March, 3, 2007, one- and two-dimensional procedures of radiative transfer equation solution. The results of the procedure are the extinction values for atmospheric aerosol and water vapor at different altitudes in the troposphere along the Earth's terminator crossing North America, Arctic, Siberia and South-Eastern Asia. The altitude range and possible latitude and altitude resoltion of atmosphere remote sensing by the lunar eclipses observation are fixed. The results of water vapor retrieval are compared with data of space experiment, the scale of vertical water vapor distribution is found.

  17. A copper vapor laser by using a copper-vapor-complex reaction at a low temperature

    OpenAIRE

    Kano, Toshiyuki; Taniguchi, Hiroshi; Saito, Hiroshi

    1987-01-01

    A copper vapor laser performance by using ametal-vapor-complex reaction (Cu+AlBr3) is reported. The laser operation is obtained at a low temperature without externalheating because of the AlBr3 vapors evaporating at a room temperature. The copper vapor laser using this metal-vapor-complex reaction has an advantage of deposition-free of a metallic copper to the laser tube wall, which is different from the copper halide and the organometallic copper lasers.

  18. What Good is Raman Water Vapor Lidar?

    Science.gov (United States)

    Whitman, David

    2011-01-01

    Raman lidar has been used to quantify water vapor in the atmosphere for various scientific studies including mesoscale meteorology and satellite validation. Now the international networks of NDACC and GRUAN have interest in using Raman water vapor lidar for detecting trends in atmospheric water vapor concentrations. What are the data needs for addressing these very different measurement challenges. We will review briefly the scientific needs for water vapor accuracy for each of these three applications and attempt to translate that into performance specifications for Raman lidar in an effort to address the question in the title of "What good is Raman water vapor Iidar."

  19. High temperature vapors science and technology

    CERN Document Server

    Hastie, John

    2012-01-01

    High Temperature Vapors: Science and Technology focuses on the relationship of the basic science of high-temperature vapors to some areas of discernible practical importance in modern science and technology. The major high-temperature problem areas selected for discussion include chemical vapor transport and deposition; the vapor phase aspects of corrosion, combustion, and energy systems; and extraterrestrial high-temperature species. This book is comprised of seven chapters and begins with an introduction to the nature of the high-temperature vapor state, the scope and literature of high-temp

  20. Vapor stabilizing surfaces for superhydrophobicity

    Science.gov (United States)

    Patankar, Neelesh

    2010-11-01

    The success of rough substrates designed for superhydrophobicity relies crucially on the presence of air pockets in the roughness grooves. This air is supplied by the surrounding environment. However, if the rough substrates are used in enclosed configurations, such as in fluidic networks, the air pockets may not be sustained in the roughness grooves. In this work a design approach based on sustaining a vapor phase of the liquid in the roughness grooves, instead of relying on the presence of air, is explored. The resulting surfaces, referred to as vapor stabilizing substrates, are deemed to be robust against wetting transition even if no air is present. Applications of this approach include low drag surfaces, nucleate boiling, and dropwise condensation heat transfer, among others.

  1. Active Hydrazine Vapor Sampler (AHVS)

    Science.gov (United States)

    Young, Rebecca C.; Mcbrearty, Charles F.; Curran, Daniel J.

    1993-01-01

    The Active Hydrazine Vapor Sampler (AHVS) was developed to detect vapors of hydrazine (HZ) and monomethylhydrazine (MMH) in air at parts-per-billion (ppb) concentration levels. The sampler consists of a commercial personal pump that draws ambient air through paper tape treated with vanillin (4-hydroxy-3-methoxybenzaldehyde). The paper tape is sandwiched in a thin cardboard housing inserted in one of the two specially designed holders to facilitate sampling. Contaminated air reacts with vanillin to develop a yellow color. The density of the color is proportional to the concentration of HZ or MMH. The AHVS can detect 10 ppb in less than 5 minutes. The sampler is easy to use, low cost, and intrinsically safe and contains no toxic material. It is most beneficial for use in locations with no laboratory capabilities for instrumentation calibration. This paper reviews the development, laboratory test, and field test of the device.

  2. Vaporization chambers and associated methods

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Terry D.; Wilding, Bruce M.; McKellar, Michael G.; Shunn, Lee P.

    2017-02-21

    A vaporization chamber may include at least one conduit and a shell. The at least one conduit may have an inlet at a first end, an outlet at a second end and a flow path therebetween. The shell may surround a portion of each conduit and define a chamber surrounding the portion of each conduit. Additionally, a plurality of discrete apertures may be positioned at longitudinal intervals in a wall of each conduit, each discrete aperture of the plurality of discrete apertures sized and configured to direct a jet of fluid into each conduit from the chamber. A liquid may be vaporized by directing a first fluid comprising a liquid into the inlet at the first end of each conduit, directing jets of a second fluid into each conduit from the chamber through discrete apertures in a wall of each conduit and transferring heat from the second fluid to the first fluid.

  3. Internal Water Vapor Photoacoustic Calibration

    Science.gov (United States)

    Pilgrim, Jeffrey S.

    2009-01-01

    Water vapor absorption is ubiquitous in the infrared wavelength range where photoacoustic trace gas detectors operate. This technique allows for discontinuous wavelength tuning by temperature-jumping a laser diode from one range to another within a time span suitable for photoacoustic calibration. The use of an internal calibration eliminates the need for external calibrated reference gases. Commercial applications include an improvement of photoacoustic spectrometers in all fields of use.

  4. Critical points of metal vapors

    Energy Technology Data Exchange (ETDEWEB)

    Khomkin, A. L., E-mail: alhomkin@mail.ru; Shumikhin, A. S. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-09-15

    A new method is proposed for calculating the parameters of critical points and binodals for the vapor–liquid (insulator–metal) phase transition in vapors of metals with multielectron valence shells. The method is based on a model developed earlier for the vapors of alkali metals, atomic hydrogen, and exciton gas, proceeding from the assumption that the cohesion determining the basic characteristics of metals under normal conditions is also responsible for their properties in the vicinity of the critical point. It is proposed to calculate the cohesion of multielectron atoms using well-known scaling relations for the binding energy, which are constructed for most metals in the periodic table by processing the results of many numerical calculations. The adopted model allows the parameters of critical points and binodals for the vapor–liquid phase transition in metal vapors to be calculated using published data on the properties of metals under normal conditions. The parameters of critical points have been calculated for a large number of metals and show satisfactory agreement with experimental data for alkali metals and with available estimates for all other metals. Binodals of metals have been calculated for the first time.

  5. Water vapor diffusion membrane development

    Science.gov (United States)

    Tan, M. K.

    1977-01-01

    An application of the water vapor diffusion technique is examined whereby the permeated water vapor is vented to space vacuum to alleviate on-board waste storage and provide supplemental cooling. The work reported herein deals primarily with the vapor diffusion-heat rejection (VD-HR) as it applies to the Space Shuttle. A stack configuration was selected, designed and fabricated. An asymmetric cellulose acetate membrane, used in reverse osmosis application was selected and a special spacer was designed to enhance mixing and promote mass transfer. A skid-mount unit was assembled from components used in the bench unit although no attempt was made to render it flight-suitable. The operating conditions of the VD-HR were examined and defined and a 60-day continuous test was carried out. The membranes performed very well throughout the test; no membrane rupture and no unusual flux decay was observed. In addition, a tentative design for a flight-suitable VD-HR unit was made.

  6. Acetone-butanol-ethanol (ABE) fermentation in an immobilized cell trickle bed reactor.

    Science.gov (United States)

    Park, C H; Okos, M R; Wankat, P C

    1989-06-05

    Acetone-butanol-ethanol (ABE) fermentation was successfully carried out in an immobilized cell trickle bed reactor. The reactor was composed of two serial columns packed with Clostridium acetobutylicum ATCC 824 entrapped on the surface of natural sponge segments at a cell loading in the range of 2.03-5.56 g dry cells/g sponge. The average cell loading was 3.58 g dry cells/g sponge. Batch experiments indicated that a critical pH above 4.2 is necessary for the initiation of cell growth. One of the media used during continuous experiments consisted of a salt mixture alone and the other a nutrient medium containing a salt mixture with yeast extract and peptone. Effluent pH was controlled by supplying various fractions of the two different types of media. A nutrient medium fraction above 0.6 was crucial for successful fermentation in a trickle bed reactor. The nutrient medium fraction is the ratio of the volume of the nutrient medium to the total volume of nutrient plus salt medium. Supplying nutrient medium to both columns continuously was an effective way to meet both pH and nutrient requirement. A 257-mL reactor could ferment 45 g/L glucose from an initial concentration of 60 g/L glucose at a rate of 70 mL/h. Butanol, acetone, and ethanol concentrations were 8.82, 5.22, and 1.45 g/L, respectively, with a butanol and total solvent yield of 19.4 and 34.1 wt %. Solvent productivity in an immobilized cell trickle bed reactor was 4.2 g/L h, which was 10 times higher than that obtained in a batch fermentation using free cells and 2.76 times higher than that of an immobilized CSTR. If the nutrient medium fraction was below 0.6 and the pH was below 4.2, the system degenerated. Oxygen also contributed to the system degeneration. Upon degeneration, glucose consumption and solvent yield decreased to 30.9 g/L and 23.0 wt %, respectively. The yield of total liquid product (40.0 wt %) and butanol selectivity (60.0 wt %) remained almost constant. Once the cells were degenerated

  7. Synthesis and evaluation of inhaled [11C]butane and intravenously injected [11C]acetone as potential radiotracers for studying inhalant abuse.

    Science.gov (United States)

    Gerasimov, Madina R; Ferrieri, Richard A; Pareto, Deborah; Logan, Jean; Alexoff, David; Ding, Yu-Shin

    2005-02-01

    The phenomenon of inhalant abuse is a growing problem in the US and many countries around the world. Yet, relatively little is known about the pharmacokinetic properties of inhalants that underlie their abuse potential. While the synthesis of 11C-labeled toluene, acetone and butane has been proposed in the literature, none of these compounds has been developed as radiotracers for PET studies. In the present report we extend our previous studies with [11C]toluene to include [11C]acetone and [11C]butane with the goal of comparing the pharmacokinetic profiles of these three volatile abused substances. Both [11C]toluene and [11C]acetone were administered intravenously and [11C]butane was administered via inhalation to anesthesized baboons. Rapid and efficient uptake of radiolabeled toluene and acetone into the brain was followed by fast clearance in the case of toluene and slower kinetics in the case of acetone. [11C]Butane was detected in the blood and brain following inhalation, but the levels of radioactivity in both tissues dropped to half of the maximal values over the period of less than a minute. To our knowledge, this is the first reported study of the in vivo brain pharmacokinetics of labeled acetone and butane in nonhuman primates. These data provide insight into the pharmacokinetic features possibly associated with the abuse liability of toluene, acetone and butane.

  8. Kinetic and mechanism of atmospheric degradation of three volatile organics compounds: acetone, phenol and catechol; Cinetique et mecanisme de degradation atmospherique de trois composes organiques volatils: l'acetone, le phenol et le catechol

    Energy Technology Data Exchange (ETDEWEB)

    Turpin, E.

    2004-12-01

    In this thesis, atmospheric degradation of three VOC (volatile organic compound), acetone, phenol and catechol, has been studied. These compounds are renowned to be some of main compounds in the atmosphere because the relative importance of their primary emissions (biogenic, gas fumes,...) and secondary emissions (VOCs oxidation). This work has been realised in two laboratories using two complementary devices. These instruments are the fast flow tube with LIF (laser induce fluorescence) and a smog Teflon chamber with gas-phase chromatography with FTIR, FID, MS. The both use of these techniques enable to determine the main pathway of the acetone oxidation with OH radical. The smog chamber's studies of the phenol and catechol reactions with OH radical enable to determine some relative rate constants and mechanisms. It's the first mechanism proposition for the catechol + OH radical reaction. These obtained results have been used to mention the atmospheric impact of these compounds. (author)

  9. Infrastructure sensing.

    Science.gov (United States)

    Soga, Kenichi; Schooling, Jennifer

    2016-08-01

    Design, construction, maintenance and upgrading of civil engineering infrastructure requires fresh thinking to minimize use of materials, energy and labour. This can only be achieved by understanding the performance of the infrastructure, both during its construction and throughout its design life, through innovative monitoring. Advances in sensor systems offer intriguing possibilities to radically alter methods of condition assessment and monitoring of infrastructure. In this paper, it is hypothesized that the future of infrastructure relies on smarter information; the rich information obtained from embedded sensors within infrastructure will act as a catalyst for new design, construction, operation and maintenance processes for integrated infrastructure systems linked directly with user behaviour patterns. Some examples of emerging sensor technologies for infrastructure sensing are given. They include distributed fibre-optics sensors, computer vision, wireless sensor networks, low-power micro-electromechanical systems, energy harvesting and citizens as sensors.

  10. Sensing temperature.

    Science.gov (United States)

    Sengupta, Piali; Garrity, Paul

    2013-04-22

    Temperature is an omnipresent physical variable reflecting the rotational, vibrational and translational motion of matter, what Richard Feynman called the "jiggling" of atoms. Temperature varies across space and time, and this variation has dramatic effects on the physiology of living cells. It changes the rate and nature of chemical reactions, and it alters the configuration of the atoms that make up nucleic acids, proteins, lipids and other biomolecules, significantly affecting their activity. While life may have started in a "warm little pond", as Charles Darwin mused, the organisms that surround us today have only made it this far by devising sophisticated systems for sensing and responding to variations in temperature, and by using these systems in ways that allow them to persist and thrive in the face of thermal fluctuation.

  11. Initial dynamics of the Norrish Type I reaction in acetone: probing wave packet motion.

    Science.gov (United States)

    Brogaard, Rasmus Y; Sølling, Theis I; Møller, Klaus B

    2011-02-10

    The Norrish Type I reaction in the S(1) (nπ*) state of acetone is a prototype case of ketone photochemistry. On the basis of results from time-resolved mass spectrometry (TRMS) and photoelectron spectroscopy (TRPES) experiments, it was recently suggested that after excitation the wave packet travels toward the S(1) minimum in less than 30 fs and stays there for more than 100 picoseconds [Chem. Phys. Lett.2008, 461, 193]. In this work we present simulated TRMS and TRPES signals based on ab initio multiple spawning simulations of the dynamics during the first 200 fs after excitation, getting quite good agreement with the experimental signals. We can explain the ultrafast decay of the experimental signals in the following manner: the wave packet simply travels, mainly along the deplanarization coordinate, out of the detection window of the ionizing probe. This window is so narrow that subsequent revival of the signal due to the coherent deplanarization vibration is not observed, meaning that from the point of view of the experiment the wave packets travels directly to the S(1) minimum. This result stresses the importance of pursuing a closer link to the experimental signal when using molecular dynamics simulations in interpreting experimental results.

  12. Integrated, systems metabolic picture of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum.

    Science.gov (United States)

    Liao, Chen; Seo, Seung-Oh; Celik, Venhar; Liu, Huaiwei; Kong, Wentao; Wang, Yi; Blaschek, Hans; Jin, Yong-Su; Lu, Ting

    2015-07-07

    Microbial metabolism involves complex, system-level processes implemented via the orchestration of metabolic reactions, gene regulation, and environmental cues. One canonical example of such processes is acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum, during which cells convert carbon sources to organic acids that are later reassimilated to produce solvents as a strategy for cellular survival. The complexity and systems nature of the process have been largely underappreciated, rendering challenges in understanding and optimizing solvent production. Here, we present a system-level computational framework for ABE fermentation that combines metabolic reactions, gene regulation, and environmental cues. We developed the framework by decomposing the entire system into three modules, building each module separately, and then assembling them back into an integrated system. During the model construction, a bottom-up approach was used to link molecular events at the single-cell level into the events at the population level. The integrated model was able to successfully reproduce ABE fermentations of the WT C. acetobutylicum (ATCC 824), as well as its mutants, using data obtained from our own experiments and from literature. Furthermore, the model confers successful predictions of the fermentations with various network perturbations across metabolic, genetic, and environmental aspects. From foundation to applications, the framework advances our understanding of complex clostridial metabolism and physiology and also facilitates the development of systems engineering strategies for the production of advanced biofuels.

  13. Green synthesis of silver nanoparticles as antibacterial agent using Rhodomyrtus tomentosa acetone extract

    Science.gov (United States)

    Voravuthikunchai, Supayang P.; Chorachoo, Julalak; Jaiswal, Lily; Shankar, Shiv

    2013-12-01

    The capability of Rhodomyrtus tomentosa acetone extract (RAE) for the production of silver nanoparticles (AgNPs) has been explored for the first time. Silver nanoparticles with a surface plasmon resonance band centered at 420-430 nm were synthesized by reacting RAE with AgNO3. Reaction time, temperature, concentration of AgNO3 and RAE could accelerate the reduction rate of Ag+ and affect AgNPs size. The nanoparticles were found to be 10-30 nm in size and spherical in shape. XRD data demonstrated crystalline nature of AgNPs dominated by (200) facets. FTIR results showed decrease in intensity of peaks at 3394, 1716 and 1618 cm-1 indicating the involvement of O-H, carbonyl group and C=C stretching with the formation of AgNPs with RAE, respectively. The C-O-C and C-N stretching suggested the presence of many phytochemicals on the surface of the nanoparticles. High negative zeta potential values confirmed the stability of AgNPs in water. In vitro antibacterial activity of AgNPs was tested against Staphylococcus aureus using broth microdilution method. AgNPs capped with RAE demonstrated profound antibacterial activity against the organisms with minimum inhibitory concentration and minimum bactericidal concentration in the range between 3.1-6.2 and 6.2-50 μgmL-1, respectively. The synthesized nanoparticles could be applied as an effective antimicrobial agent against staphylococcal infections.

  14. Effects of nutritional enrichment on the production of acetone-butanol-ethanol (ABE) by Clostridium acetobutylicum.

    Science.gov (United States)

    Choi, Sung Jun; Lee, Joungmin; Jang, Yu-Sin; Park, Jin Hwan; Lee, Sang Yup; Kim, In Ho

    2012-12-01

    Clostridium acetobutylicum is an industrially important organism that produces acetone-butanol-ethanol (ABE). The main objective of this study was to characterize the effects of increased cell density on the production of ABE during the phase transition from acidogenesis to solventogenesis in C. acetobutylicum. The increased ABE productivity of C. acetobutylicum was obtained by increasing the cell density using a newly designed medium (designated C. a cetobutylicum medium 1; CAM1). The maximum OD(600) value of C. acetobutylicum ATCC 824 strain obtained with CAM1 was 19.7, which is 1.8 times higher than that obtained with clostridial growth medium (CGM). The overall ABE productivity obtained in the CAM1-fermetation of the ATCC 824 strain was 0.83 g/L/h, which is 1.5 times higher than that (0.55 g/L/h) obtained with CGM. However, the increased productivity obtained with CAM1 did not result in an increase in the final ABE titer, because phase transition occurred at a high titer of acids.

  15. Improvement of acetone, butanol, and ethanol production from woody biomass using organosolv pretreatment.

    Science.gov (United States)

    Amiri, Hamid; Karimi, Keikhosro

    2015-10-01

    A suitable pretreatment is a prerequisite of efficient acetone-butanol-ethanol (ABE) production from wood by Clostridia. In this study, organosolv fractionation, an effective pretreatment with ability to separate lignin as a co-product, was evaluated for ABE production from softwood pine and hardwood elm. ABE production from untreated woods was limited to the yield of 81 g ABE/kg wood and concentration of 5.5 g ABE/L. Thus, the woods were pretreated with aqueous ethanol at elevated temperatures before hydrolysis and fermentation to ABE by Clostridium acetobutylicum. Hydrolysis of pine and elm pretreated at 180 °C for 60 min resulted in the highest sugar concentrations of 16.8 and 23.2 g/L, respectively. The hydrolysate obtained from elm was fermented to ABE with the highest yield of 121.1 g/kg and concentration of 11.6 g/L. The maximum yield of 87.9 g/kg was obtained from pine pretreated for 30 min at 150 °C. Moreover, structural modifications in the woods were investigated and related to the improvements. The woody biomasses are suitable feedstocks for ABE production after the organosolv pretreatment. Effects of the pretreatment conditions on ABE production might be related to the reduced cellulose crystallinity, reduced lignin and hemicellulose content, and lower total phenolic compounds in the hydrolysates.

  16. Lignin depolymerisation in supercritical carbon dioxide/acetone/water fluid for the production of aromatic chemicals.

    Science.gov (United States)

    Gosselink, Richard J A; Teunissen, Wouter; van Dam, Jan E G; de Jong, Ed; Gellerstedt, Göran; Scott, Elinor L; Sanders, Johan P M

    2012-02-01

    Valorisation of lignin plays a key role in further development of lignocellulosic biorefinery processes the production of biofuels and bio-based materials. In the present study, organosolv hardwood and wheat straw lignins were converted in a supercritical fluid consisting of carbon dioxide/acetone/water (300-370°C, 100bar) to a phenolic oil consisting of oligomeric fragments and monomeric aromatic compounds with a total yield of 10-12% based on lignin. These yields are similar to the state-of-the-art technologies such as base-catalysed thermal processes applied for lignin depolymerisation. Addition of formic acid increases the yield of monomeric aromatic species by stabilizing aromatic radicals. Supercritical depolymerisation of wheat straw and hardwood lignin yielded monomeric compounds in different compositions with a maximum yield of 2.0% for syringic acid and 3.6% for syringol, respectively. The results of the present study showed that under the applied conditions competition occurred between lignin depolymerisation and recondensation of fragments.

  17. Butanol production in acetone-butanol-ethanol fermentation with in situ product recovery by adsorption.

    Science.gov (United States)

    Xue, Chuang; Liu, Fangfang; Xu, Mengmeng; Tang, I-Ching; Zhao, Jingbo; Bai, Fengwu; Yang, Shang-Tian

    2016-11-01

    Activated carbon Norit ROW 0.8, zeolite CBV901, and polymeric resins Dowex Optipore L-493 and SD-2 with high specific loadings and partition coefficients were studied for n-butanol adsorption. Adsorption isotherms were found to follow Langmuir model, which can be used to estimate the amount of butanol adsorbed in acetone-butanol-ethanol (ABE) fermentation. In serum-bottle fermentation with in situ adsorption, activated carbon showed the best performance with 21.9g/L of butanol production. When operated in a fermentor, free- and immobilized-cell fermentations with adsorption produced 31.6g/L and 54.6g/L butanol with productivities of 0.30g/L·h and 0.45g/L·h, respectively. Thermal desorption produced a condensate containing ∼167g/L butanol, which resulted in a highly concentrated butanol solution of ∼640g/L after spontaneous phase separation. This in situ product recovery process with activated carbon is energy efficient and can be easily integrated with ABE fermentation for n-butanol production.

  18. Kinetic modeling and sensitivity analysis of acetone-butanol-ethanol production.

    Science.gov (United States)

    Shinto, Hideaki; Tashiro, Yukihiro; Yamashita, Mayu; Kobayashi, Genta; Sekiguchi, Tatsuya; Hanai, Taizo; Kuriya, Yuki; Okamoto, Masahiro; Sonomoto, Kenji

    2007-08-01

    A kinetic simulation model of metabolic pathways that describes the dynamic behaviors of metabolites in acetone-butanol-ethanol (ABE) production by Clostridium saccharoperbutylacetonicum N1-4 was proposed using a novel simulator WinBEST-KIT. This model was validated by comparing with experimental time-course data of metabolites in batch cultures over a wide range of initial glucose concentrations (36.1-295 mM). By introducing substrate inhibition, product inhibition of butanol, activation of butyrate and considering the cessation of metabolic reactions in the case of insufficiency of energy after glucose exhaustion, the revised model showed 0.901 of squared correlation coefficient (r(2)) between experimental time-course of metabolites and calculated ones. Thus, the final revised model is assumed to be one of the best candidates for kinetic simulation describing dynamic behavior of metabolites in ABE production. Sensitivity analysis revealed that 5% increase in reaction of reverse pathway of butyrate production (R(17)) and 5% decrease in reaction of CoA transferase for butyrate (R(15)) highly contribute to high production of butanol. These system analyses should be effective in the elucidation which pathway is metabolic bottleneck for high production of butanol.

  19. Acetone-butanol-ethanol production in a novel continuous flow system.

    Science.gov (United States)

    Elbeshbishy, Elsayed; Dhar, Bipro Ranjan; Hafez, Hisham; Lee, Hyung-Sool

    2015-08-01

    This study investigates the potential of using a novel integrated biohydrogen reactor clarifier system (IBRCS) for acetone-butanol-ethanol (ABE) production using a mixed culture at different organic loading rates (OLRs). The results of this study showed that using a setting tank after the fermenter and recycle the settled biomass to the fermenter is a practical option to achieve high biomass concentration in the fermenter and thus sustainable ABE fermentation in continuous mode. The average ABE concentrations of 2.3, 7.0, and 14.6gABE/L which were corresponding to ABE production rates of 0.4, 1.4, and 2.8gABE/Lreactorh were achieved at OLRs of 21, 64, and 128gCOD/Lreactord, respectively. The main volatile fatty acids components in the effluent were acetic, propionic, and butyric acids. Acetic acid was the predominant component in the OLR-1, while butyric acid was the predominant acid in OLRs 2 and 3.

  20. Acetone-butanol-ethanol production from Kraft paper mill sludge by simultaneous saccharification and fermentation.

    Science.gov (United States)

    Guan, Wenjian; Shi, Suan; Tu, Maobing; Lee, Yoon Y

    2016-01-01

    Paper mill sludge (PS), a solid waste from pulp and paper industry, was investigated as a feedstock for acetone-butanol-ethanol (ABE) production by simultaneous saccharification and fermentation (SSF). ABE fermentation of paper sludge by Clostridium acetobutylicum required partial removal of ash in PS to enhance its enzymatic digestibility. Enzymatic hydrolysis was found to be a rate-limiting step in the SSF. A total of 16.4-18.0g/L of ABE solvents were produced in the SSF of de-ashed PS with solid loading of 6.3-7.4% and enzyme loading of 10-15FPU/g-glucan, and the final solvent yield reached 0.27g/g sugars. No pretreatment and pH control were needed in ABE fermentation of paper sludge, which makes it an attractive feedstock for butanol production. The results suggested utilization of paper sludge should not only consider the benefits of buffering effect of CaCO3 in fermentation, but also take into account its inhibitory effect on enzymatic hydrolysis.

  1. Optical properties of Germanium nanoparticles synthesized by pulsed laser ablation in acetone

    Directory of Open Access Journals (Sweden)

    Saikiran eVadavalli

    2014-10-01

    Full Text Available Germanium (Ge nanoparticles (NPs are synthesized by means of pulsed laser ablation of bulk germanium target immersed in acetone with ns laser pulses at different pulse energies. The fabricated NPs are characterized by employing different techniques such as UV-visible absorption spectroscopy, photoluminescence, micro-Raman spectroscopy, transmission electron microscopy (TEM and field emission scanning electron microscopy (FESEM. The mean size of the Ge NPs is found to vary from few nm to 40 nm with the increase in laser pulse energy. Shift in the position of the absorption spectra is observed and also the photoluminescence peak shift is observed due to quantum confinement effects. High resolution TEM combined with micro-Raman spectroscopy confirms the crystalline nature of the generated germanium nanoparticles. The formation of various sizes of germanium NPs at different laser pulse energies is evident from the asymmetry in the Raman spectra and the shift in its peak position towards the lower wavenumber side. The FESEM micrographs confirm the formation of germanium micro/nanostructures at the laser ablated position of the bulk germanium. In particular, the measured NP sizes from the micro-Raman phonon quantum confinement model are found in good agreement with TEM measurements of Ge NPs.

  2. Anthelmintic activity of acetone extracts from South African plants used on egg hatching of Haemonchus contortus

    Directory of Open Access Journals (Sweden)

    Gerda Fouche

    2016-03-01

    Full Text Available The nematode, Haemonchus contortus, is responsible for major economic losses in the livestock industry. The management of parasites such as H. contortus has been through the use of synthetic parasiticides. This has resulted in the presence of residues in meat and milk, which affects food safety. The development of resistance to available anthelmintics coupled with their high cost has further complicated matters. This has led to the investigation of alternative methods to manage nematodes, including the use of plants and plant extracts as a potential source of novel anthelmintics. Acetone extracts were prepared from 15 South African plant species and their anthelmintic activity determined using the egg hatch assay (EHA. The leaf extract of Cleome gynandra had the best inhibitory activity (68% ± 3% at a concentration of 2.5 mg/mL, followed by the stem extract of Maerua angolensis (65% ± 5%. The extracts had a relatively low toxicity on Vero cells determined by the MTT (3-(4,5-dimethylthiazol-2-yl-2,5- diphenyltetrazolium bromide cellular assay.

  3. Poly[[aquadi-μ3-malonato-hexaphenyl­ditin(IV)] acetone solvate

    Science.gov (United States)

    Win, Yip Foo; Teoh, Siang Guan; Vikneswaran, M. R.; Goh, Jia Hao; Fun, Hoong-Kun

    2010-01-01

    The asymmetric unit of the title polymeric complex, {[Sn2=(C6H5)6(C3H2O4)(H2O)]·C3H6O}n, comprises of two Sn cations, one malonate anion and a non-coordinating acetone solvent mol­ecule. Both crystallographically independent Sn cations are five-coordinated by two O and three C atoms in a distorted trigonal-bipyrimidal geometry. One of the Sn cations is bridged by the malonate units, affording polymeric chains which run along [001]. Weak intra­molecular C—H⋯π inter­actions stabilize the mol­ecular structure. In the crystal structure, adjacent chains are inter­connected by inter­molecular O—H⋯O and C—H⋯O hydrogen bonds into a three-dimensional supra­molecular structure. A weak inter­molecular C—H⋯π inter­action is also observed. PMID:21579332

  4. Optimization of wastewater microalgae saccharification using dilute acid hydrolysis for acetone, butanol, and ethanol fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Yessica; Ellis, Joshua T.; Miller, Charles D.; Sims, Ronald C.

    2015-02-01

    Exploring and developing sustainable and efficient technologies for biofuel production are crucial for averting global consequences associated with fuel shortages and climate change. Optimization of sugar liberation from wastewater algae through acid hydrolysis was determined for subsequent fermentation to acetone, butanol, and ethanol (ABE) by Clostridium saccharoperbutylacetonicum N1-4. Acid concentration, retention time, and temperature were evaluated to determine optimal hydrolysis conditions by assessing the sugar and ABE yield as well as the associated costs. Sulfuric acid concentrations ranging from 0-1.5 M, retention times of 40-120 min, and temperatures from 23°C- 90°C were combined to form a full factorial experiment. Acid hydrolysis pretreatment of 10% dried wastewater microalgae using 1.0 M sulfuric acid for 120 min at 80-90°C was found to be the optimal parameters, with a sugar yield of 166.1 g for kg of dry algae, concentrations of 5.23 g/L of total ABE, and 3.74 g/L of butanol at a rate of USD $12.83 per kg of butanol.

  5. [Photodissociation of Acetylene and Acetone using Step-Scan Time-Resolved FTIR Emission Spectroscopy

    Science.gov (United States)

    McLaren, Ian A.; Wrobel, Jacek D.

    1997-01-01

    The photodissociation of acetylene and acetone was investigated as a function of added quenching gas pressures using step-scan time-resolved FTIR emission spectroscopy. Its main components consist of Bruker IFS88, step-scan Fourier Transform Infrared (FTIR) spectrometer coupled to a flow cell equipped with Welsh collection optics. Vibrationally excited C2H radicals were produced from the photodissociation of acetylene in the unfocused experiments. The infrared (IR) emission from these excited C2H radicals was investigated as a function of added argon pressure. Argon quenching rate constants for all C2H emission bands are of the order of 10(exp -13)cc/molecule.sec. Quenching of these radicals by acetylene is efficient, with a rate constant in the range of 10(exp -11) cc/molecule.sec. The relative intensity of the different C2H emission bands did not change with the increasing argon or acetylene pressure. However, the overall IR emission intensity decreased, for example, by more than 50% when the argon partial pressure was raised from 0.2 to 2 Torr at fixed precursor pressure of 160mTorr. These observations provide evidence for the formation of a metastable C2H2 species, which are collisionally quenched by argon or acetylene. Problems encountered in the course of the experimental work are also described.

  6. Acetone-butanol-ethanol production from corn stover pretreated by alkaline twin-screw extrusion pretreatment.

    Science.gov (United States)

    Zhang, Yuedong; Hou, Tongang; Li, Bin; Liu, Chao; Mu, Xindong; Wang, Haisong

    2014-05-01

    In this study, the alkaline twin-screw extrusion pretreated corn stover was subjected to enzymatic hydrolysis after washing. The impact of solid loading and enzyme dose on enzymatic hydrolysis was investigated. It was found that 68.2 g/L of total fermentable sugar could be obtained after enzymatic hydrolysis with the solid loading of 10 %, while the highest sugar recovery of 91.07 % was achieved when the solid loading was 2 % with the cellulase dose of 24 FPU/g substrate. Subsequently, the hydrolyzate was fermented by Clostridium acetobutylicum ATCC 824. The acetone-butanol-ethanol (ABE) production of the hydrolyzate was compared with the glucose, xylose and simulated hydrolyzate medium which have the same reducing sugar concentration. It was shown that 7.1 g/L butanol and 11.2 g/L ABE could be produced after 72 h fermentation for the hydrolyzate obtained from enzymatic hydrolysis with 6 % solid loading. This is comparable to the glucose and simulated hydrozate medium, and the overall ABE yield could reach 0.112 g/g raw corn stover.

  7. Hepatoprotective effect of acetone semicarbazone on Ehrlich ascites carcinoma induced carcinogenesis in experimental mice

    Institute of Scientific and Technical Information of China (English)

    Farhadul Islam; Shaikh Mohummad Mohsin Ali; Jahan Ara Khanam

    2013-01-01

    Objective:To determine the hepatoprotective effect of acetone semicarbazone (ASC) in vivo in normal and Ehrlich ascites carcinoma (EAC) bearing male Swiss albino mice. Methods:Drug-induced changes in biochemical and behavioral parameters at dose of 2.0 mg/kg body weight for 14 d and nullifying the toxicity induced by EAC cells were studied. The histopathology studies of the protective effects of ASC on vital organs were also assessed. Results:The administration of ASC made insignificant changes in body weight and behavioral (salivation, diarrhea, muscular numbness) changes during treatment period due to minor toxicity were minimized after the treatment in normal mice. The biochemical parameters, including serum glutamate pyruvate transaminase, glutamate oxaloactate transaminase, alkaline phosphatase, serum glucose, cholesterol, urea, triglyceride and billirubin changed modestly in normal mice receiving ASC. Though the treatment continued, these values gradually decreased to normal level after the treatment. In EAC bearing mice, the toxic effects due to EAC cells in all cases were nullified by treatment with the ASC. Significant abnormalities were not detected in histology of the various organs of the normal mice treated with ASC. Conclusions: ASC can, therefore, be considered safe in formulating novel anticancer drug, as it exhibits strong protective effect against EAC cell bearing mice.

  8. 用修正的Polanyi-Dubinin方程描述有机蒸气-水蒸气在活性炭上的吸附平衡%MODIFIED POLANYI-DUBININ EQUATION TO ORRELATE ADSORPTION EQUILIBRIUM OF VOC-WATER VAPOR MIXTURES ON ACTIVATED CARBON

    Institute of Scientific and Technical Information of China (English)

    高华生; 汪大翚; 叶芸春; 谭天恩

    2001-01-01

    Long-column method was used to determine the adsorption isotherms of 4 VOCs (benzene, toluene, chloroform and acetone) in concentration range of 250~5000?mg*m-3 on a commercial activated-carbon under different humidity levels at 30?℃.A modified Polanyi-Dubinin equation was proposed to correlate the adsorption equilibrium of different VOC-water vapor systems. Among 3 methods of calculating the Relative Affinity Coefficient β used,the Molar Volume method and the Molecular Parachor method proved to be suitable for the calculation with better precision than the Electronic Polarization method. Calculation results were satisfactory for the benzene-, toluene-, and chloroform-water vapor/activated carbon systems, but poor for acetone possibly because of its strong polarity.The equation could be used to estimate the detaining effect of atmospheric humidity on the adsorption equilibrium of VOCs on activated carbon.

  9. Performances of electrically heated microgroove vaporizers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An electrically heated microgroove vaporizer was proposed. The vaporizer mainly comprised an outer tube, an inner tube and an electrical heater cartridge. Microgrooves were fabricated on the external surface of the inner tube by micro-cutting method,which formed the flow passage for fluid between the external surface of the inner tube and the internal surface of the outer tube.Experiments related to the temperature rise response of water and the thermal conversion efficiency of vaporizer were done to estimate the influences of microgroove's direction, feed flow rate and input voltage on the performances of the vaporizer. The results indicate that the microgroove's direction dominates the vaporizer performance at a lower input voltage. The longitudina lmicrogroove vaporizer exhibits the best performances for the temperature rise response of water and thermal conversion efficiency of vaporizer. For a moderate input voltage, the microgroove's direction and the feed flow rate of water together govern the vaporizer performances. The input voltage becomes the key influencing factor when the vaporizer works at a high input voltage, resulting in the similar performances of longitudinal, oblique and latitudinal microgroove vaporizers.

  10. Production Technology and Market of Phenol and Acetone in China%我国苯酚丙酮生产技术及市场

    Institute of Scientific and Technical Information of China (English)

    朱丽娜; 李洪涛; 姜道华; 刘龙; 何英华; 刘方舟; 张德顺

    2014-01-01

    Phenol/acetone production technology was introduced. The phenol/acetone productivity, market supply and demand in China was summarized. Some suggestions were given for the development of phenol/acetone.%介绍了苯酚/丙酮的生产技术,并对几种生产技术进行了比较。另外,简要介绍了目前我国苯酚/丙酮的产能及市场供需情况,对苯酚/丙酮的发展提出了建议。

  11. Complex dynamic behavior in the bromate-oxalic acid-acetone-Mn(II) oscillating reaction in a continuous stirred tank reactor (CSTR)

    Science.gov (United States)

    Silva, Lucyane C.; Faria, Roberto B.

    2007-05-01

    The oscillating reaction bromate-oxalic acid-acetone-Mn(II)-sulfuric acid was observed for the first time in a CSTR at 20 °C. Depending on the bromate concentrations and flow rate, the system showed large amplitude oscillations, two kinds of mixed mode oscillations, quasiperiodicity and bursts of large amplitude oscillations, all mapped in a phase diagram. More complex behavior was favored at low bromate concentrations. The system without acetone was discovered to oscillate too, but the more complex patterns were not seen, indicating that acetone is implied in their formation.

  12. Molecular orbital imaging of the acetone S2 excited state using time-resolved (e, 2e) electron momentum spectroscopy.

    Science.gov (United States)

    Yamazaki, Masakazu; Oishi, Keiya; Nakazawa, Hiroyuki; Zhu, Chaoyuan; Takahashi, Masahiko

    2015-03-13

    We report a time-resolved (e, 2e) experiment on the deuterated acetone molecule in the S2 Rydberg state with a lifetime of 13.5 ps. The acetone S2 state was prepared by a 195 nm pump laser and probed with electron momentum spectroscopy using a 1.2 keV incident electron beam of 1 ps temporal width. In spite of the low data statistics as well as of the limited time resolution (±35  ps) due to velocity mismatch, the experimental results clearly demonstrate that electron momentum spectroscopy measurements of short-lived transient species are feasible, opening the door to time-resolved orbital imaging in momentum space.

  13. Characterization of Upper-Troposphere Water Vapor Measurements during AFWEX Using LASE

    Energy Technology Data Exchange (ETDEWEB)

    Ferrare, Richard; Browell, E. V.; Ismail, S.; Barrick, J. D. W.; Diskin, G. S.; Sachse, G. W.; Kooi, S. A.; Brasseur, L. H.; Brackett, V. G.; Clayton, M. B.; Goldsmith, John E M.; Lesht, B. M.; Podolske, J. R.; Schmidlin, F. J.; Turner, David D.; Whiteman, D. N.; Demoz, B. B.; Tobin, D. C.; Revercomb, Henry E.; Miloshevich, Larry M.; di Girolamo, P.

    2004-12-01

    Water vapor profiles from NASA's Lidar Atmospheric Sensing Experiment (LASE) system acquired during the ARM/FIRE Water Vapor Experiment (AFWEX) are used to characterize upper troposphere water vapor (UTWV) measured by ground-based Raman lidars, radiosondes, and in situ aircraft sensors over the Department of Energy Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site in northern Oklahoma. LASE was deployed from the NASA DC-8 aircraft and measured water vapor over the ARM SGP Central Facility (CF) site during seven flights between November 27 and December 10, 2000. Initially, the DOE ARM SGP Cloud and Radiation Testbed (CART) Raman lidar (CARL) UTWV profiles were about 5-7% wetter than LASE in the upper troposphere, and the Vaisala RS80-H radiosonde profiles were about 10% drier than LASE between 8-12 km. Scaling the Vaisala water vapor profiles to match the precipitable water vapor (PWV) measured by the ARM SGP microwave radiometer (MWR) did not change these results significantly. By accounting for an overlap correction of the CARL water vapor profiles and by employing schemes designed to correct the Vaisala RS80-H calibration method and account for the time response of the Vaisala RS80H water vapor sensor, the average differences between the CARL and Vaisala radiosonde upper troposphere water vapor profiles are reduced to about 5%, which is within the ARM goal of mean differences of less than 10%. The LASE and DC-8 in situ Diode Laser Hygrometer (DLH) UTWV measurements generally agreed to within about 3 to 4%. The DC-8 in situ frost point cryogenic hygrometer and Snow White chilled mirror measurements were drier than the LASE, Raman lidars, and corrected Vaisala RS80H measurements by about 10-25% and 10-15%, respectively. Sippican (formerly VIZ manufacturing) carbon hygristor radiosondes exhibited large variabilities and poor agreement with the other measurements. PWV derived from the LASE profiles agreed to within about 3% on average with

  14. Photoelectron spectroscopy of phthalocyanine vapors

    Energy Technology Data Exchange (ETDEWEB)

    Berkowitz, J.

    1979-01-01

    The He(I) photoelectron spectra of several metal phthalocyanines and metal-free phthalocyanine vapor shows that: a sharp peak at 4.99 eV is an artifact due to ionization of atomic He by He(II) radiation; the first phthalocyanine peak (metal-containing or metal-free) occurs at 6.4 eV; and the metal-like d orbitals lie at least 1 to 2 eV deeper, except in the case of Fe. (DLC)

  15. Simple Method to Synthesize Functionalized Carbon Nanotubes Employing Cobalt Nitrate and Acetone by Using Spray Pyrolysis Deposition Technique

    Directory of Open Access Journals (Sweden)

    Jorge A. Gómez

    2012-01-01

    Full Text Available Recently alcohols and ketones have been employed to sensitize CNT by CVD. A study has shown the importance of the chemical nature of those carbon precursors on the characteristics of the CNT (carbon nanotubes obtained. In the present work we show the influence of the catalyst employed on the synthesis of functionalized multiwall carbon nanotubes (MWCNTs utilizing acetone as carbon source and cobalt nitrate Co(NO32 as catalyst.

  16. Achieving concentrated graphene dispersions in water/acetone mixtures by the strategy of tailoring Hansen solubility parameters

    Science.gov (United States)

    Yi, Min; Shen, Zhigang; Zhang, Xiaojing; Ma, Shulin

    2013-01-01

    Although exfoliating graphite to give graphene paves a new way for graphene preparation, a general strategy of low-boiling-point solvents and high graphene concentration is still highly required. In this study, using the strategy of tailoring Hansen solubility parameters (HSP), a method based on exfoliation of graphite in water/acetone mixtures is demonstrated to achieve concentrated graphene dispersions. It is found that in the scope of blending two mediocre solvents, tailoring the HSP of water/acetone mixtures to approach the HSP of graphene could yield graphene dispersions at a high concentration of up to 0.21 mg ml-1. The experimentally determined optimum composition of the mixtures occurs at an acetone mass fraction of ˜75%. The trend of concentration varying with mixture compositions could be well predicated by the model, which relates the concentration to the mixing enthalpy within the scope of HSP theory. The resultant dispersion is highly stabilized. Atomic force microscopic statistical analysis shows that up to ˜50% of the prepared nanosheets are less than 1 nm thick after 4 h sonication and 114g centrifugation. Analyses based on diverse characterizations indicate the graphene sheets to be largely free of basal plane defects and oxidation. The filtered films are also investigated in terms of their electrical and optical properties to show reasonable conductivity and transparency. The strategy of tailoring HSP, which can be easily extended to various solvent systems, and water/acetone mixtures here, extends the scope for large-scale production of graphene in low-boiling-point solutions.

  17. Direct evidence of iNOS-mediated in vivo free radical production and protein oxidation in acetone-induced ketosis.

    Science.gov (United States)

    Stadler, Krisztian; Bonini, Marcelo G; Dallas, Shannon; Duma, Danielle; Mason, Ronald P; Kadiiska, Maria B

    2008-08-01

    Diabetic patients frequently encounter ketosis that is characterized by the breakdown of lipids with the consequent accumulation of ketone bodies. Several studies have demonstrated that reactive species are likely to induce tissue damage in diabetes, but the role of the ketone bodies in the process has not been fully investigated. In this study, electron paramagnetic resonance (EPR) spectroscopy combined with novel spin-trapping and immunological techniques has been used to investigate in vivo free radical formation in a murine model of acetone-induced ketosis. A six-line EPR spectrum consistent with the alpha-(4-pyridyl-1-oxide)-N-t-butylnitrone radical adduct of a carbon-centered lipid-derived radical was detected in the liver extracts. To investigate the possible enzymatic source of these radicals, inducible nitric oxide synthase (iNOS) and NADPH oxidase knockout mice were used. Free radical production was unchanged in the NADPH oxidase knockout but much decreased in the iNOS knockout mice, suggesting a role for iNOS in free radical production. Longer-term exposure to acetone revealed iNOS overexpression in the liver together with protein radical formation, which was detected by confocal microscopy and a novel immunospin-trapping method. Immunohistochemical analysis revealed enhanced lipid peroxidation and protein oxidation as a consequence of persistent free radical generation after 21 days of acetone treatment in control and NADPH oxidase knockout but not in iNOS knockout mice. Taken together, our data demonstrate that acetone administration, a model of ketosis, can lead to protein oxidation and lipid peroxidation through a free radical-dependent mechanism driven mainly by iNOS overexpression.

  18. 1,1,2,2-Tetrakis(dimethylaminoethane-1,2-diium bis(tetraphenylborate acetone disolvate

    Directory of Open Access Journals (Sweden)

    Willi Kantlehner

    2012-05-01

    Full Text Available The title compound, C10H24N42+·2C24H20B−·2C3H6O, crystallizes with two acetone solvent molecules per asymmetric unit. In the dication, both amidinium units are twisted about the central C—C single bond by 63.8 (3° and the positive charges are delocalized over both N—C—N planes.

  19. Thickness dependency of sol-gel derived ZnO thin films on gas sensing behaviors

    Energy Technology Data Exchange (ETDEWEB)

    Kakati, Nitul; Jee, Seung Hyun; Kim, Su Hyun; Oh, Jun Young; Yoon, Young Soo, E-mail: yoonys@yonsei.ac.k

    2010-10-29

    ZnO thin films were fabricated by a sol-gel method using Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O as starting material in order to prepare an acetone gas sensor. A homogeneous and stable solution was prepared by dissolving the zinc acetate in a solution of ethanol and monoethanolamine. The sol-gel solution is coated on alumina substrates with various thicknesses by spin coating technique and heat treated to grow crystalline ZnO thin films. The effect of thickness on physical and electrical properties of as deposited ZnO thin films has been studied. The as deposited ZnO thin films were characterized by X-ray diffraction spectroscopy, field emission scanning electron microscopy and atomic force microscopy. The root mean square surface roughness factors increase with thickness of the films and found 3.9, 6.6, 9.0, and 11.28 nm for 80-, 220-, 450- and 620-nm-thin films respectively. The activation energies of the films are calculated from the resistance temperature characteristics. The sensitivities of the ZnO films towards the acetone gas were determined at an operating temperature of 200 {sup o}C. The sensitivity towards acetone vapor is strongly depending on surface morphology of the ZnO thin films.

  20. Change in tensile properties of neoprene and nitrile gloves after repeated exposures to acetone and thermal decontamination.

    Science.gov (United States)

    Gao, Pengfei; Tomasovic, Beth

    2005-11-01

    This study investigated the change in tensile properties of neoprene and nitrile gloves after repeated cycles of exposure to acetone, followed by thermal decontamination. The glove was exposed to acetone (outer surface in contact with chemical), subjected to thermal decontamination, and tested for the tensile strength and the ultimate elongation. Thermal decontamination was carried out inside an oven for 16 hours at 100 degrees C. The exposure/decontamination procedure was repeated for a maximum of 10 cycles. For neoprene versus acetone, the mean tensile strength consistently decreased after each exposure/decontamination cycle. Multiple comparisons indicated that the mean tensile strengths between the new swatches and each exposure/decontamination group were significantly different (p 0.05). The mean tensile strength for the new swatches was 37.1 MPa and the mean tensile strength after nine exposure/decontamination cycles was 36.0 MPa, with a loss less than 3%. The largest single cycle loss for ultimate elongation occurred during the first exposure/decontamination cycle for both glove materials. In our previous study, decisions regarding the effectiveness of the decontamination process were based on having no discernible change in the breakthrough time and steady-state permeation rate. The results of this study indicate that the effectiveness of the decontamination process cannot be based on permeation parameters alone but must also take into account the change in physical properties.

  1. Antifungal activity of acetone extracts from Punica granatum L., Quercus suber L. and Vicia faba L.

    Science.gov (United States)

    Akroum, S

    2017-03-01

    Human and animal mycoses become more frequent and more resistant to traditional treatments. In this work, we tested the in vitro antifungal activity of acetonic extracts of Punica granatum L., Quercus suber L. and Vicia faba L. against seven pathogen fungi and the in vivo antifungal activity against Candida albicans and Trichophyton mentagrophytes. The phytochemical screening was also carried out and showed that the extracts contained mainly proanthocyanidins. Other polyphenols were also present but in low quantity. The acetone extract of V. faba L. gave a good in vitro inhibition of yeasts and was the most active for treating candidiasis in mice. It decreased the percentage of mortality with only 20μg. But the in vivo antifungal activity of this extract on T. mentagrophytes was low. It only showed a small diminution of crusting and erythema after the administration of 100μg. On the contrary, the acetone extracts of P. granatum L. had a poor activity against yeasts and a better one against moulds. It gave the best in vivo antifungal activity against T. mentagrophytes by healing animals with 40μg. The extract of P. granatum L. gave also an interesting in vivo antifungal activity against T. mentagrophytes with an active dose of 80μg.

  2. Production of an acetone-butanol-ethanol mixture from Clostridium acetobutylicum and its conversion to high-value biofuels.

    Science.gov (United States)

    Sreekumar, Sanil; Baer, Zachary C; Pazhamalai, Anbarasan; Gunbas, Gorkem; Grippo, Adam; Blanch, Harvey W; Clark, Douglas S; Toste, F Dean

    2015-03-01

    Clostridium acetobutylicum is a bacterial species that ferments sugar to a mixture of organic solvents (acetone, butanol and ethanol). This protocol delineates a methodology to combine solventogenic clostridial fermentation and chemical catalysis via extractive fermentation for the production of biofuel blendstocks. Extractive fermentation of C. acetobutylicum is operated in fed-batch mode with a concentrated feed solution (500 grams per liter glucose and 50 grams per liter yeast extract) for 60 h, producing in excess of 40 g of solvents (acetone, butanol and ethanol) between the completely immiscible extractant and aqueous phases of the bioreactor. After distillation of the extractant phase, the acetone, butanol and ethanol mixture is upgraded to long-chain ketones over a palladium-hydrotalcite (Pd-HT) catalyst. This reaction is generally carried out in batch with a high-pressure Q-tube for 20 h at 250 °C. Following this protocol enables the production of ∼0.5 g of high-value biofuel precursors from a 1.7-g portion of fermentation solvents.

  3. Effect of Tween 80 and Acetone on the Secretion, 
Structure and Antioxidant Activities of Exopolysaccharides from Lentinus tigrinus.

    Science.gov (United States)

    He, Peixin; Wu, Shuangshuang; Pan, Lige; Sun, Siwen; Mao, Duobin; Xu, Chunping

    2016-09-01

    In this study, the effects of the addition of Tween 80 and acetone on secretion, structure and antioxidant activities of Lentinus tigrinus exopolysaccharides (EPS) were investigated. It was found that Tween 80 and acetone displayed a stimulatory effect on EPS secretion. The EPS obtained by the addition of Tween 80 (EPS-T), acetone (EPS-A) and control (EPS--C) were purified by Sepharose CL-6B gel filtration chromatography and molecular mass of purified fractions was estimated to be 22.1, 137 and 12 kDa, respectively. Monosaccharide composition analysis indicated that EPS-T, EPS-A and EPS-C were mainly composed of glucose and mannose. Congo Red test indicated that EPS-T and EPS-A had a highly ordered conformation of triple helix, while EPS-C had a random coil conformation. Furthermore, EPS-A exhibited higher DPPH scavenging and antiproliferative activities than EPS--C and EPS-T, which might be attributed to the molecular mass.

  4. The Acetone Extract of Sclerocarya birrea (Anacardiaceae Possesses Antiproliferative and Apoptotic Potential against Human Breast Cancer Cell Lines (MCF-7

    Directory of Open Access Journals (Sweden)

    Nicoline Fri Tanih

    2013-01-01

    Full Text Available Interesting antimicrobial data from the stem bark of Sclerocarya birrea, which support its use in traditional medicine for the treatment of many diseases, have been delineated. The current study was aimed to further study some pharmacological and toxicological properties of the plant to scientifically justify its use. Anticancer activity of water and acetone extracts of S. birrea was evaluated on three different cell lines, HT-29, HeLa, and MCF-7 using the cell titre blue viability assay in 96-well plates. Apoptosis was evaluated using the acridine orange and propidium iodide staining method, while morphological structure of treated cells was examined using SEM. The acetone extract exhibited remarkable antiproliferative activities on MCF-7 cell lines at dose- and time-dependent manners (24 h and 48 h of incubation. The extract also exerted apoptotic programmed cell death in MCF-7 cells with significant effect on the DNA. Morphological examination also displayed apoptotic characteristics in the treated cells, including clumping, condensation, and culminating to budding of the cells to produce membrane-bound fragmentation, as well as formation of apoptotic bodies. The acetone extract of S. birrea possesses antiproliferative and apoptotic potential against MCF-7-treated cells and could be further exploited as a potential lead in anticancer therapy.

  5. Adsorption characteristics of acetone, chloroform and acetonitrile on sludge-derived adsorbent, commercial granular activated carbon and activated carbon fibers.

    Science.gov (United States)

    Tsai, Jiun-Horng; Chiang, Hsiu-Mei; Huang, Guan-Yinag; Chiang, Hung-Lung

    2008-06-15

    The adsorption characteristics of chloroform, acetone, and acetonitrile on commercial activated carbon (C1), two types of activated carbon fibers (F1 and F2), and sludge adsorbent (S1) was investigated. The chloroform influent concentration ranged from 90 to 7800 ppm and the acetone concentration from 80 to 6900 ppm; the sequence of the adsorption capacity of chloroform and acetone on adsorbents was F2>F1 approximately C1 approximately S1. The adsorption capacity of acetonitrile ranged from 4 to 100 mg/g, corresponding to the influent range from 43 to 2700 ppm for C1, S1, and F1. The acetonitrile adsorption capacity of F2 was approximately 20% higher than that of the other adsorbents at temperaturescarbon fibers is higher than that of the other adsorbents due to their smaller fiber diameter and higher surface area. The micropore diffusion coefficient of VOC on activated carbon and sludge adsorbent was approximately 10(-4) cm2 s(-1). The diffusion coefficient of VOC on carbon fibers ranged from 10(-8) to 10(-7) cm2 s(-1). The small carbon fiber pore size corresponds to a smaller diffusion coefficient.

  6. Vapor Pressure Data Analysis and Statistics

    Science.gov (United States)

    2016-12-01

    Army Edgewood Chemical Biological Center P vapor pressure (Pa) p vapor pressure (Torr) R ideal gas constant RVX O-isobutyl-S-[2(diethylamino...Respondents should be aware that notwithstanding any other provision of law , no person shall be subject to any penalty for failing to comply with a...1-Hexadecanol Vapor Pressure Data from Kemme and Kreps11 .......................................10 2. Antoine Constants (Equation 3), Standard

  7. Does acetone react with HO2 in the upper-troposphere?

    Directory of Open Access Journals (Sweden)

    J. Lelieveld

    2012-02-01

    Full Text Available Recent theoretical calculations showed that reaction with HO2 could be an important sink for acetone (CH3C(OCH3 and source of acetic acid (CH3C(OOH in cold parts of the atmosphere (e.g. the tropopause region. This work details studies of HO2 + CH3C(OCH3 (CH32C(OHOO (R1 in laboratory-based and theoretical chemistry experiments; the atmospheric significance of Reaction (R1 was assessed in a global 3-D chemical model. Pulsed laser-kinetic experiments were conducted, for the first time, at the low-temperatures representative of the tropopause. Reaction with NO converted HO2 to OH for detection by laser induced fluorescence. Reduced yields of OH at T 2 by CH3C(OCH3 with a forward rate coefficient greater than 2 × 10−12 cm3 molecule−1 s−1. No evidence for Reaction (R1 was observed at T > 230 K, probably due to rapid thermal dissociation back to HO2 + CH3C(OCH3. Numerical simulations of the data indicate that these experiments were sensitive to only (R1a HO2-CH3C(OCH3 complex formation, the first step in (R1. Rearrangement (R1b of the complex to form peroxy radicals, and hence the atmospheric significance of (R1 has yet to be rigorously verified by experiment. Results from new quantum chemical calculations indicate that K1 is characterised by large uncertainties of at least an order of magnitude at T 3C(OCH3 near the tropopause, it cannot explain observations of CH3C(OOH throughout the troposphere.

  8. A model to assess the feasibility of shifting reaction equilibrium by acetone removal in the transamination of ketones using 2‐propylamine

    DEFF Research Database (Denmark)

    Tufvesson, Pär; Bach, Christian; Woodley, John

    2014-01-01

    Acetone removal by evaporation has been proposed as a simple and cheap way to shift the equilibrium in the biocatalytic asymmetric synthesis of optically pure chiral amines, when 2‐propylamine is used as the amine donor. However, dependent on the system properties, this may or may not be a suitable...... strategy. To avoid excessive laboratory work a model was used to assess the process feasibility. The results from the current study show that a simple model of the acetone removal dependence on temperature and sparging gas flowrate can be developed and fits the experimental data well. The model for acetone...... volatilities (Henry's constant). The simulations were used to estimate the substrate losses and also the maximum yield that could be expected. The approach was seen to give a clear indication for which target amines the acetone evaporation strategy would be feasible and for which amines it would not. The study...

  9. Influence of Soil Moisture on Soil Gas Vapor Concentration for Vapor Intrusion

    OpenAIRE

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    Mathematical models have been widely used in analyzing the effects of various environmental factors in the vapor intrusion process. Soil moisture content is one of the key factors determining the subsurface vapor concentration profile. This manuscript considers the effects of soil moisture profiles on the soil gas vapor concentration away from any surface capping by buildings or pavement. The “open field” soil gas vapor concentration profile is observed to be sensitive to the soil moisture di...

  10. Photo-catalytic oxidation of acetone on a TiO2 powder: An in situ FTIR investigation

    Energy Technology Data Exchange (ETDEWEB)

    Szanyi, János; Kwak, Ja Hun

    2015-09-01

    In situ transmission infrared spectroscopy was used to investigate the photo-oxidation of acetone on a commercial, oxidized TiO2 (P25) powder catalyst under UV irradiation at ambient temperature, in the absence and presence of gas phase O2. The photochemistry of a number of organic molecules (1-butanone, methanol and acetic acid,) under the same conditions was also studied in order to identify reaction intermediates and products formed in the photo-oxidation of acetone. Under anaerobic conditions (in the absence of gas phase oxygen) limited extent of photo-oxidation of acetone took place on the oxidized TiO2 sample. In the presence of O2 in the gas phase, however, acetone was completely converted to acetates and formates, and ultimately CO2. The initial step in the sequence of photo-induced reactions is the ejection of a methyl radical, resulting in the formation of surface acetates (from the acetyl group) and formates (from the methyl radicals). Acetate ions are also converted to formates, that, in turn, photo-oxidized to CO2. Under the experimental conditions applied the accumulation of carbonates and bicarbonates were observed on the TiO2 surface as the photo-oxidation of acetone proceeded (this was also observed during the course of photo-oxidation of all the other organics studied here). When the initial radical ejection step produced hydrocarbons containing more than one C atoms (as in the case in 2-butanone and mesytil oxide), the formation of aldehydes on the catalyst surface was also observed as a result of secondary reactions. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy. JHK also acknowledges the support of this work by the 2014 Research Fund of UNIST (Ulsan National Institute of Science and Technology, Ulsan, Korea). The authors thank M

  11. 乙醚与丙酮燃烧反应机理%Mechanisms of Ethyl Ether and Acetone Combustion Reactions

    Institute of Scientific and Technical Information of China (English)

    高志崇

    2012-01-01

    利用公式△H=-0.1196n/A计算了乙醚和丙酮分别在氧气和空气中燃烧反应的温度,并推测了乙醚和丙酮燃烧反应的机理.乙醚在氧气中燃烧反应的火焰温度理论值为3272K,与测定温度3134K接近,误差为4.40%.丙酮在空气中燃烧反应的火焰温度理论值为1292K,与测定温度173K接近,误差为1.49%.根据乙醚和丙酮燃烧反应的火焰温度,推测乙醚和丙酮燃烧反应机理为:(1)O2+hv→2O·;(2)(C2H5)2O→4C+4H2+H2O(乙醚),CH3COCH3→3C+2H2+H2O(丙酮);(3)H2+O·→H2O+hv;(4)C+O·→CO+hv;(5)2CO+O2→2CO2.%The flame temperatures produced by ethyl ether and acetone burning in oxygen and air in order were calculated by the formula △H = -0. 1196nA, and the mechanisms of ethyl ether and acetone combustion reactions were deduced. The theoretical flame temperature of ethyl ether burning in oxygen was 3272K, near to its actual temperature 3134K, the error was 4.40%. The theoretical flame temperature of acetone burning in air was 1292K, near to its actual temperature 1273K, the error was 1.49%. According to the flame tempera- tures, the mechanisms of ethyl ether and acetone combustion reactions were deduced as follow: ( 1 ) O2 + hv→ 2O ; (2) ( C2 H5 ) 2O→4C + 4H2 + H2O ( ethyl ether), CH3 COCH3→3 C + 2 H2 + H2O ( acetone ) ; ( 3 ) H2 +O→H2O + bv; (4)C + O→CO + hv; (5)2CO + O2→2CO2.

  12. Detection of Organic Vapors Based on Photoluminescent Bragg-Reflective Porous Silicon Interferomete.

    Science.gov (United States)

    Ahn, Jihoon; Cho, Bomin; Kim, Sungsoo; Sohn, Honglae

    2015-07-01

    Novel photoluminescent Bragg-reflective porous silicon, exhibiting dual optical properties, both the optical reflectivity and photoluminescence, was developed and used for sensing organic vapors. Photoluminescent Bragg-reflective porous silicon samples were prepared by an electrochemical etch of n-type silicon under the illumination. The etching solution consisted of a 3:1 volume mixture of aqueous 48% hydrofluoric acid and absolute ethanol. The typical etch parameters for the generation of photoluminescent Bragg-reflective porous silicon involved a periodic square wave current with 50 repeats. The surface of photoluminescent Bragg-reflective porous silicon was characterized by a FT-IR spectroscopy. Both reflectivity and photoluminescence were simultaneously measured under the exposure of organic vapors. The shift of reflection band to the longer wavelength and the quenching of photoluminescence under the exposure of various organic vapors were observed.

  13. Using Si Diodes To Detect H2 Liquid/Vapor Interfaces

    Science.gov (United States)

    Dempsey, Paula Jean; Fabik, Richard

    1994-01-01

    Commercially available silicon-diode temperature sensors used to detect interfaces between hydrogen liquid and hydrogen vapor at steady-state saturation conditions. Sensors mounted at short intervals along rod to form rake-like array. Array inserted in tank with rod oriented vertically, where it senses level of liquid hydrogen to resolution equal to interval between sensors. Basic idea to measure voltage across sensor while supplying small electric current that heats sensor. Because vapor cools sensor less effectively than liquid does, sensor's steady-state temperature greater when sensor surrounded by vapor than when immersed in liquid. Voltage output decreases as temperature increases for silicon diodes. Thus, temperature (voltage) reading used to determine whether liquid level above or below sensor.

  14. Measurements of acetone and other gas phase product yields from the OH-initiated oxidation of terpenes by proton-transfer-reaction mass spectrometry (PTR-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Wisthaler, A.; Lindinger, W. [University of Innsbruck (Austria). Institut fuer Ionenphysik; Jensen, N.R.; Winterhalter, R.; Hjorth, J. [Joint Research Centre, European Commission, Environment Institute, Ispra (Italy)

    2001-07-01

    The atmospheric oxidation of several terpenes appears to be a potentially relevant source of acetone in the atmosphere. Proton-transfer-reaction mass spectrometry was used as an on-line analytical method in a chamber study to measure acetone and other gas phase products from the oxidation of {alpha}- and {beta}-pinene initiated by OH radicals in air and in the presence of NO{sub x}. Acetone may be formed promptly, following attack by the OH radical on the terpene, via a series of highly unstable radical intermediates. It can also be formed by slower processes, via degradation of stable non-radical intermediates such as pinonaldehyde and nopinone. Primary acetone and pinonaldehyde molar yields of 11{+-}2% (one {sigma}) and 34{+-}9% (one {sigma}), respectively, were found from the reaction between {alpha}-pinene and the OH radical. After all {alpha}-pinene had been consumed, an additional formation of acetone due to the degradation of stable non-radical intermediates was observed. The total amount of acetone formed was 15{+-}2% (one {sigma}) of the reacted {alpha}-pinene. An upper limit of 12{+-}3% (one {sigma}) for the acetone molar yield from the oxidation of pinonaldehyde was established. From the reaction between {beta}-pinene and the OH radicals, primary acetone and nopinone molar yields of 13{+-}2% (one {sigma}) and 25{+-}3% (one {sigma}), respectively, were observed. Additional amounts of acetone were formed by the further degradation of the primary product, such as the most abundant product nopinone. The total amount of acetone formed was 16{+-}2% (one {sigma}) of the reacted {beta}-pinene. An upper limit of 12{+-}2% (one {sigma}) for the acetone molar yield from the oxidation of nopinone was established. The observed product yields from {alpha}- and {beta}-pinene are in good agreement with other studies using mass-spectrometric and gas chromatographic analytical techniques, but differ significantly from previous studies using spectroscopic methods. Possible

  15. Physical synthesis methodology and enhanced gas sensing and photoelectrochemical performance of 1D serrated zinc oxide-zinc ferrite nanocomposites.

    Science.gov (United States)

    Liang, Yuan-Chang; Liu, Shang-Luen; Hsia, Hao-Yuan

    2015-12-01

    We successfully prepared one-dimensional ZnO-ZnFe2O4 (ZFO) heterostructures for acetone gas-sensing and photoelectrochemical applications, by using sputter deposition of ZFO crystallites on ZnO nanostructure templates. The nanoscale ZFO crystallites were homogeneously coated on the surfaces of the ZnO nanostructures. Electron microscope images revealed that the ZnO-ZFO heterostructures exhibited a serrated surface morphology. Coating the ZnO nanostructures with a ZFO aggregated layer appreciably enhanced their acetone gas-sensing capability at 250 °C in comparison with pure ZnO nanostructures. The presence of many depleted nanoscale ZFO crystallites, the rugged surface of the heterostructures, and electron depletion at the ZnO/ZFO interface might contribute to the enhanced acetone gas-sensing response. Furthermore, the larger surface area and higher light absorption of ZnO-ZFO relative to the surface area and light absorption of ZnO were correlated with a substantial enhancement of the photocurrent value of ZnO-ZFO in photoelectrochemical tests produced by the simulated solar light irradiation.

  16. Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

    Directory of Open Access Journals (Sweden)

    Dora M. Paolucci

    2011-03-01

    Full Text Available A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index and sensor response are discussed.

  17. A portable fluorescence detector for fast ultra trace detection of explosive vapors

    Science.gov (United States)

    Xin, Yunhong; He, Gang; Wang, Qi; Fang, Yu

    2011-10-01

    This paper developed a portable detector based on a specific material-based fluorescent sensing film for an ultra trace detection of explosives, such as 2,4,6-trinitrotoluene (TNT) or its derivate 2,4-dinitrotoluene (DNT), in ambient air or on objects tainted by explosives. The fluorescent sensing films are based on single-layer chemistry and the signal amplification effect of conjugated polymers, which exhibited higher sensitivity and shorter response time to TNT or DNT at their vapor pressures. Due to application of the light emitting diode and the solid state photomultiplier and the cross-correlation-based circuit design technology, the device has the advantages of low-power, low-cost, small size, and an improved signal to noise ratio. The results of the experiments showed that the detector can real-time detect and identify of explosive vapors at extremely low levels; it is suitable for the identification of suspect luggage, forensic analyses, or battlefields clearing.

  18. Radio-frequency Electrometry Using Rydberg Atoms in Vapor Cells: Towards the Shot Noise Limit

    Science.gov (United States)

    Kumar, Santosh; Fan, Haoquan; Jahangiri, Akbar; Kuebler, Harald; Shaffer, James P.; 5. Physikalisches Institut, Universitat Stuttgart, Germany Collaboration

    2016-05-01

    Rydberg atoms are a promising candidate for radio frequency (RF) electric field sensing. Our method uses electromagnetically induced transparency with Rydberg atoms in vapor cells to read out the effect that the RF electric field has on the Rydberg atoms. The method has the potential for high sensitivity (pV cm-1 Hz- 1 / 2) and can be self-calibrated. Some of the main factors limiting the sensitivity of RF electric field sensing from reaching the shot noise limit are the residual Doppler effect and the sensitivity of the optical read-out using the probe laser. We present progress on overcoming the residual Doppler effect by using a new multi-photon scheme and reaching the shot noise detection limit using frequency modulated spectroscopy. Our experiments also show promise for studying quantum optical effects such as superradiance in vapor cells using Rydberg atoms. This work is supported by DARPA, ARO, and NRO.

  19. Assessment of response of the Intoxilyzer 8000C to volatiles of forensic relevance in vitro, part I: acetone, isopropanol, and methanol.

    Science.gov (United States)

    Watterson, James H

    2009-03-01

    The response of the Intoxilyzer 8000C (version approved for evidentiary breath alcohol testing in Canada) to volatile solvents in vitro is described. Acetone, isopropanol, and methanol were prepared as aqueous solutions or dilutions of standard alcohol solution (SAS; 1.21 mg ethanol/mL) to generate apparent blood ethanol concentrations (aBEC) of 50 or 80 mg/dL. Solvent concentrations examined were relevant to clinical or impaired driving scenarios. Replicates of 20 aBEC measurements were made for each mixture and the actuation of the "INTERFERANT DETECT" message (IDM) was noted. Measurements of aqueous acetone (0-40 mg acetone/dL), isopropanol (0-100 mg isopropanol/dL), and methanol (0-100 mg methanol/dL) yielded aBECs of 0, 0-43, and 0-55 mg/dL, respectively. The minimum concentration examined at which the IDM was actuated in 100% of replicates was 25, 30, and 100 mg/dL for acetone, isopropanol, and methanol, respectively. The maximum concentration examined at which the IDM was actuated in none of the replicates was 5, 10, and 50 mg/dL for acetone, isopropanol, and methanol, respectively. In examinations of acetone/isopropanol mixtures in diluted SAS where the IDM was not always actuated, the maximum BEC overestimation was 10 mg/dL. Overall, the potential for significant undetected BEC overestimation is low and may be further reduced through truncation of test results and subject observation.

  20. Analysis of the origin and importance of acetone and isopropanol levels in the blood of the deceased for medico-legal testimony

    Directory of Open Access Journals (Sweden)

    Aleksandra Borowska-Solonynko

    2015-03-01

    Full Text Available The aim of the study was to analyze the incidence of acetone and isopropanol in the blood of the deceased, and to assess cases in which the compounds have been detected with a focus on their origin and usefulness for medico-legal testimony. Material and methods: The study material consisted of results of tests detecting ethyl alcohol and reports of autopsies performed at the Department of Forensic Medicine, Medical University of Warsaw, from January 2008 to April 2009 – a total of 2,475 cases. The test group proper (group B comprised only those cases in which acetone was detected in blood, either with or without isopropanol [n = 202 (8.2%]. The blood levels of isopropanol varied depending on the cause of death. The need for differentiating the origin of isopropanol in the case of its presence in the blood of the deceased was pointed out. Results : The results of the present study show that the differentiation should be based on the isopropanol and acetone concentration ratio, as isopropanol concentration alone is not sufficient for preparing expert opinions. Even high concentrations of isopropanol, when accompanied by even higher concentrations of acetone, imply that isopropanol could have been formed as a result of acetone transformations. Isopropanol concentrations exceeding acetone levels strongly point to the exogenous origin of isopropanol, particularly when high levels of ethanol are concurrently detected.

  1. Origin of Enhanced Reactivity of a Microsolvated Nucleophile in Ion Pair SN2 Reactions: The Cases of Sodium p-Nitrophenoxide with Halomethanes in Acetone.

    Science.gov (United States)

    Li, Qiang-Gen; Xu, Ke; Ren, Yi

    2015-04-30

    In a kinetic experiment on the SN2 reaction of sodium p-nitrophenoxide with iodomethane in acetone-water mixed solvent, Humeres et al. (J. Org. Chem. 2001, 66, 1163) found that the reaction depends strongly on the medium, and the fastest rate constant was observed in pure acetone. The present work tries to explore why acetone can enhance the reactivity of the title reactions. Accordingly, we make a mechanistic study on the reactions of sodium p-nitrophenoxide with halomethanes (CH3X, X = Cl, Br, I) in acetone by using a supramolecular/continuum model at the PCM-MP2/6-311+G(d,p)//B3LYP/6-311+G(d,p) level, in which the ion pair nucleophile is microsolvated by one to three acetone molecules. We compared the reactivity of the microsolvated ion pair nucleophiles with solvent-free ion pair and anionic ones. Our results clearly reveal that the microsolvated ion pair nucleophile is favorable for the SN2 reactions; meanwhile, the origin of the enhanced reactivity induced by microsolvation of the nucleophile is discussed in terms of the geometries of transition state (TS) structures and activation strain model, suggesting that lower deformation energies and stronger interaction energies between the deformed reactants in the TS lead to the lower overall reaction barriers for the SN2 reaction of microsolvated sodium p-nitrophenoxide toward halomethanes in acetone.

  2. Supramolecular sensing with phosphonate cavitands.

    Science.gov (United States)

    Pinalli, Roberta; Dalcanale, Enrico

    2013-02-19

    Molecular recognition is a recurrent theme in chemical sensing because of the importance of selectivity for sensor performances. The popularity of molecular recognition in chemical sensing has resulted from the progress made in mastering weak interactions, which has enabled the design of synthetic receptors according to the analyte to be detected. However, the availability of a large pool of modular synthetic receptors so far has not had a significant impact on sensors used in the real world. This technological gap has emerged because of the difficulties in transferring the intrinsic molecular recognition properties of a given receptor from solution to interfaces and in finding high fidelity transduction modes for the recognition event. This Account focuses on the ways to overcome these two bottlenecks, and we recount our recent efforts to produce highly selective supramolecular sensors using phosphonate cavitands as receptors. Through two examples, we present an overview of the different operating strategies that are implemented depending on whether the interface is vapor-solid or liquid-solid. First we describe the selective detection of short chain aliphatic alcohols in the vapor phase. In this example, we solved a key issue common to all sensors for organic vapors: the dissection of the specific interaction (between cavitand and the alcohol) from ubiquitous nonspecific dispersion interactions (between the analytes and interferents in the solid layer). We removed responses resulting from the nonspecific interactions of the analytes with interferents by directly connecting the recognition event at the interface to the transduction mechanism (photoinduced charge transfer). The second example addresses the specific detection of sarcosine in urine. Recent research has suggested that sarcosine can serve as reliable biomarker of the aggressive forms of prostate cancer. Tetraphosphonate cavitands can complex N-methyl ammonium salts with impressive selectivity in

  3. Soil vapor extraction with dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, N.R. [Univ. of Waterloo, Ontario (Canada)

    1996-08-01

    The physical treatment technology of soil vapor extraction (SVE) is reliable, safe, robust, and able to remove significant amounts of mass at a relatively low cost. SVE combined with a pump-and-treat system to create a dewatered zone has the opportunity to remove more mass with the added cost of treating the extracted groundwater. Various limiting processes result in a significant reduction in the overall mass removal rates from a SVE system in porous media. Only pilot scale, limited duration SVE tests conducted in low permeability media have been reported in the literature. It is expected that the presence of a fracture network in low permeability media will add another complexity to the limiting conditions surrounding the SVE technology. 20 refs., 4 figs.

  4. Tungsten chemical vapor deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Kiichi; Takeda, Nobuo.

    1993-07-13

    A tungsten chemical vapor deposition method is described, comprising: a first step of selectively growing a first thin tungsten film of a predetermined thickness in a desired region on the surface of a silicon substrate by reduction of a WF[sub 6] gas introduced into an atmosphere of a predetermined temperature containing said silicon substrate; and a second step of selectively growing a second tungsten film of a predetermined thickness on said first thin tungsten film by reduction of said WF[sub 6] with a silane gas further introduced into said atmosphere, wherein the surface state of said substrate is monitored by a pyrometer and the switching from said first step to said second step is performed when the emissivity of infrared light from the substrate surfaces reaches a predetermined value.

  5. Can a drawover vaporizer be a pushover?

    Science.gov (United States)

    Taylor, J C; Restall, J

    1994-10-01

    Bench testing was carried out to establish whether the vapour output from an OMV50 vaporizer, as used in the Triservice apparatus, differs according to whether the carrier gas is either drawn or pushed through the vaporizer. Results show that the differences in output concentration between the two modes were clinically insignificant.

  6. Boron carbide whiskers produced by vapor deposition

    Science.gov (United States)

    1965-01-01

    Boron carbide whiskers have an excellent combination of properties for use as a reinforcement material. They are produced by vaporizing boron carbide powder and condensing the vapors on a substrate. Certain catalysts promote the growth rate and size of the whiskers.

  7. Vapor Pressures of Several Commercially Used Alkanolamines

    NARCIS (Netherlands)

    Klepacova, Katarina; Huttenhuis, Patrick J. G.; Derks, Peter W. J.; Versteeg, Geert F.; Klepáčová, Katarína

    2011-01-01

    For the design of acid gas treating processes, vapor-liquid equilibrium (VLE) data must be available of the solvents to be applied. In this study the vapor pressures of seven frequently industrially used alkanolamines (diethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, N,N-diethylethano

  8. Engineering vapor-deposited polyimides

    Science.gov (United States)

    Tsai, Feng-Yu

    The vapor deposition polymerization (VDP) of PMDA-ODA polyimide was studied parametrically to produce microcapsules and thin films with desirable properties and quality for the Inertial Confinement Fusion (ICF) experiments. The mechanical properties and gas permeability were determined at temperatures from 10 to 573 K. The VDP polyimide possessed distinct properties including lower gas permeability and stronger tensile properties from those of solution-cast Kapton, which were attributed to the presence of cross-linking. Processing parameters determining the properties of the VDP polyimide were identified: (1) utilizing air instead of nitrogen as the atmosphere of imidization increased the permeability by 140%, lowered the activation energy for permeation, and reduced the tensile strength by 30% without affecting the Young's modulus; (2) imidizing at faster heating rates increased the permeability by up to 50% and reduced the activation energy for permeation with 50% lowered tensile strength and impervious Young's modulus; (3) bi-axial stretching increased the permeability by up to three orders of magnitude. Analyses via IR spectroscopy, X-ray diffraction, and density measurement revealed that the effects of the processing parameters were results of the modifications in the crystallinity and molecular weight. The VDP polyimide underwent minor degradation in the tensile strength and elongation at break with unaffected Young's modulus and permeability upon absorbing 120 MGy of beta-radiation. Substituting a fluorinated dianhydride monomer, 6FDA, for PMDA in the optimized VDP process yielded 6FDA-ODA polyimide microcapsules and films with 50-fold increased permeability and comparable mechanical properties. The results of this study enable the production of polyimide microcapsules that will greatly facilitate the ICF experiments, and will broaden the applications of vapor-deposited polyimides in other technology fields.

  9. Microbial growth with vapor-phase substrate

    Energy Technology Data Exchange (ETDEWEB)

    Hanzel, Joanna; Thullner, Martin; Harms, Hauke [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, 04318 Leipzig (Germany); Wick, Lukas Y., E-mail: lukas.wick@ufz.de [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, 04318 Leipzig (Germany)

    2011-04-15

    Limited information exists on influences of the diffusive transport of volatile organic contaminants (VOC) on bacterial activity in the unsaturated zone of the terrestrial subsurface. Diffusion of VOC in the vapor-phase is much more efficient than in water and results in effective VOC transport and high bioavailability despite restricted mobility of bacteria in the vadose zone. Since many bacteria tend to accumulate at solid-water, solid-air and air-water interfaces, such phase boundaries are of a special interest for VOC-biodegradation. In an attempt to evaluate microbial activity toward air-borne substrates, this study investigated the spatio-temporal interplay between growth of Pseudomonas putida (NAH7) on vapor-phase naphthalene (NAPH) and its repercussion on vapor-phase NAPH concentrations. Our data demonstrate that growth rates of strain PpG7 were inversely correlated to the distance from the source of vapor-phase NAPH. Despite the high gas phase diffusivity of NAPH, microbial growth was absent at distances above 5 cm from the source when sufficient biomass was located in between. This indicates a high efficiency of suspended bacteria to acquire vapor-phase compounds and influence headspace concentration gradients at the centimeter-scale. It further suggests a crucial role of microorganisms as biofilters for gas-phase VOC emanating from contaminated groundwater or soil. - Research highlights: > Suspended bacteria have a high efficiency to degrade vapor-phase naphthalene. > Bacteria influence NAPH vapor-phase concentration gradients at centimeter-scale. > Microbial growth on vapor-phase naphthalene is inversely correlated to its source. > Bacteria are good biofilters for gas-phase NAPH emanating from contaminated sites. - Suspended bacteria have a high efficiency to degrade vapor-phase naphthalene and effectively influence vapor-phase naphthalene concentration gradients at the centimeter scale.

  10. HANFORD CHEMICAL VAPORS WORKER CONCERNS & EXPOSURE EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    ANDERSON, T.J.

    2006-12-20

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors.

  11. Directional Solidification of Pure Succinonitrile and a Succinonitrile-Acetone Alloy

    Science.gov (United States)

    Simpson, James E.; deGroh, Henry C., III; Garimella, Suresh V.

    2000-01-01

    An experimental study of the horizontal Bridgman growth of pure succinonitrile (SCN) and of a succinonitrile-1.0 mol% acetone alloy (SCN-1.0 mol.% ACE) has been performed. Experiments involving both a stationary thermal field (no-growth case) and a translating thermal field (growth case) were conducted. Growth rates of 2 and 40 micrometers/sec were investigated. For the pure SCN experiments, the velocity field in the melt was estimated using video images of seed particles in the melt. Observations of the seed particles indicate that a primary longitudinal convective cell is formed. The maximum velocity of two different particles which traveled along similar paths was the same and equal to 1.49 +/- 0.01 mm/s. The general accuracy of velocity measurements is estimated to be +/-0.08 mm/s, though the data shows consistency to within +/- 0.02 mm/s. The shape of the solid/liquid interface was also quantitatively determined. The solid/liquid interface was stable (non-dendritic and non-cellular) but not flat: rather it was significantly distorted by the influence of connection in the melt and, for the growth case, by the moving temperature boundary conditions along the ampoule. It was found that the interface shape and position were highly dependent on the alignment of the ampoule in the apparatus. Consequently, the ampoule was carefully aligned for all experiments. The values for front location agree with those determined in previous experiments. For the alloy experiments, the solid/liquid interface was determined to be unstable at growth rates greater than 2.8 micrometers/sec, but stable for the cases of no-growth and growth at 2 micrometers/sec. When compared to the shape of the pure SCN interface, the alloy interface forms closer to the cold zone, indicating that the melting temperature decreased due to the alloying element. Extensive temperature measurements were performed on the outside of the ampoule containing pure SCN. The resulting thermal profiles are presented

  12. Adsorption of some metal complexes derived from acetyl acetone on activated carbon and purolite S-930

    Directory of Open Access Journals (Sweden)

    Salam A.H. Al-Ameri

    2014-12-01

    Full Text Available A new Schiff base (HL derived from condensation of p-anisidine and acetyl acetone has been prepared and used as a chelating ligand to prepare Cr(III, Mn(II, Co(II, Ni(II and Cu(II complexes. The study of the nature of these complexes formed in ethanol solution following the mole ratio method (2:1, L:M gave results which were compared successfully with these obtained from isolated solid state studies. These studies revealed that the complexes having square planner geometry of the type (ML2, M = Co(II, Ni(II and Cu(II, and octahedral geometry of the type [CrIIIL2(H2O2]Cl and [MNIIL2(H2O2]. The adsorption studies of three complexes Cr(III, Mn(II, and Co(II on activated carbon, H and Na-forms of purolite S-930 resin show high adsorption percentage for Cr(III on purolite S-930 due to ion exchange interaction compared with high adsorption of neutral Mn(II, Co(II complexes on activated charcoal. Linear plot of log Qe versus log Ce showed that the adsorption isotherm of these three complexes on activated carbon, H and Na-forms of purolite S-930 surface obeys Freundlich isotherm and was similar to S-curve type according to Giles classification which investigates heterogeneous adsorption. The regression values indicate that the adsorption data for these complexes fitted well within the Freundlich isothermal plots for the concentration studied. The accuracy and precision of the concentration measurements of these complexes were determined by preparing standard laboratory samples, the results show relative error ranging from ±1.08 to 5.31, ±1.04 to 4.82 and ±0.28 to 3.09 and the relative standard deviation did not exceed ±6.23, ±2.77 and ±4.38% for A1, A2 and A3 complexes, respectively.

  13. Seasonal variations of acetone in the upper troposphere-lower stratosphere of the northern midlatitudes as observed by ACE-FTS

    Science.gov (United States)

    Dufour, G.; Szopa, S.; Harrison, J. J.; Boone, C. D.; Bernath, P. F.

    2016-05-01

    This study reports on the climatological acetone distribution and seasonal variations in the upper troposphere and lower stratosphere of the northern midlatitudes, derived from observations by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) onboard SCISAT. The acetone profiles retrieved from 5 to ∼20 km cover the period from January 2004 to September 2010. The 1σ statistical fitting errors are typically ∼5-20% within the upper troposphere (UT), increasing in the lower stratosphere (LS) with decreasing acetone. The systematic errors range between 15% and 20%. The largest UT acetone mixing ratios (∼1200 ppt on average in July over Siberia) are observed in summer in the northern mid- and high latitudes. Mixing ratios are larger over continental regions than over the ocean. Comparisons with airborne measurements available in the literature point toward a possible underestimation in acetone retrieved from ACE-FTS. The largest differences occur primarily in winter and for the background values. This underestimation is attributed to the complexity of the spectral region used for the retrieval. The annual cycle of acetone for the 30-70°N midlatitude band shows a maximum during summer, reflecting the annual cycle of the primary terrestrial biogenic source of acetone. By comparison with ACE-FTS, the LMDz-INCA global climate-chemistry model systematically overestimates acetone mixing ratios lower than 400 ppt. This overestimation is thus generalized for the lower stratosphere, the Tropics and beyond 70°N for the upper troposphere. In contrast, in the upper troposphere of the 30-70°N region, where the acetone levels are the highest (>450 ppt on average), the model-observation differences are in the range of the observation uncertainty. However, in this region, the model fails to capture the annual cycle of acetone, culminating in July. A seasonal cycle can only be obtained by considering high biogenic emissions but this cycle is shifted

  14. The Shell Structure Effect on the Vapor Selectivity of Monolayer-Protected Gold Nanoparticle Sensors

    Directory of Open Access Journals (Sweden)

    Rui-Xuan Huang

    2014-02-01

    Full Text Available Four types of monolayer-protected gold nanoclusters (MPCs were synthesized and characterized as active layers of vapor sensors. An interdigitated microelectrode (IDE and quartz crystal microbalance (QCM were used to measure the electrical resistance and mass loading changes of MPC films during vapor sorption. The vapor sensing selectivity was influenced by the ligand structure of the monolayer on the surface of gold nanoparticles. The responses of MPC-coated QCM were mainly determined according to the affinity between the vapors and surface ligands of MPCs. The responses to the resistance changes of the MPC films were due to the effectiveness of the swelling when vapor was absorbed. It was observed that resistive sensitivity to polar organics could be greatly enhanced when the MPC contained ligands that contain interior polar functional groups with exterior nonpolar groups. This finding reveals that reducing interparticle attraction by using non-polar exterior groups could increase effective swelling and therefore enhance the sensitivity of MPC-coated chemiresistors.

  15. Reusable macroporous photonic crystal-based ethanol vapor detectors by doctor blade coating.

    Science.gov (United States)

    Ko, Ya-Ling; Tsai, Hui-Ping; Lin, Kun-Yi; Chen, Ying-Chu; Yang, Hongta

    2017-02-01

    This research reports the development of sensitive and reversible vapor detection by using three-dimensional macroporous photonic crystals. A scalable and roll-to-roll compatible doctor blade coating technology is utilized to fabricate flexible macroporous poly(ethoxylated trimethylolpropane triacrylate) (PETPTA) films with hexagonal close-packed pores which are interconnected. The pores are then coated with a layer of poly(2-hydroxyethyl methacrylate) (PHEMA) to create macroporous PHEMA/PETPTA films. The condensation of vapors in the PHEMA coated macroporous films leads to the increase of both the PHEMA swelling degree and the effective refractive index of the diffractive medium, resulting in the red-shift and amplitude reduction of the optical stop bands. The optical measurements reveal that the diffraction from the as-prepared macroporous photonic crystals sensitively monitors the vapor pressure of ethanol since the PHEMA layer displays a great volume dependence on ethanol due to a decreased Flory-Huggins mixing parameter. The dependence of the diffraction wavelength on vapor pressure and the reproducibility of vapor sensing have also been investigated in this study.

  16. A Nanoengineered Conductometric Device for Accurate Analysis of Elemental Mercury Vapor.

    Science.gov (United States)

    Griffin, Matthew J; Kabir, K M Mohibul; Coyle, Victoria E; Kandjani, Ahmad Esmaielzadeh; Sabri, Ylias M; Ippolito, Samuel J; Bhargava, Suresh K

    2016-02-01

    We developed a novel conductometric device with nanostructured gold (Au) sensitive layer which showed high-performance for elemental mercury (Hg(0)) vapor detection under simulated conditions that resemble harsh industrial environments. That is, the Hg(0) vapor sensing performance of the developed sensor was investigated under different operating temperatures (30-130 °C) and working conditions (i.e., humid) as well as in the presence of various interfering gas species, including ammonia (NH3), hydrogen sulfide (H2S), nitric oxide (NO), carbon mono-oxide (CO), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen (H2), methane (CH4), and volatile organic compounds (VOCs) such as ethylmercaptan (EM), acetaldehyde (MeCHO) and methyl ethyl ketone (MEK) among others. The results indicate that the introduction of Au nanostructures (referred to as nanospikes) on the sensor's surface enhanced the sensitivity toward Hg(0) vapor by up-to 450%. The newly developed sensor exhibited a limit of detection (LoD) (∼35 μg/m(3)), repeatability (∼94%), desorption efficiency (100%) and selectivity (∼93%) when exposed to different concentrations of Hg(0) vapor (0.5 to 9.1 mg/m(3)) and interfering gas species at a chosen operating temperature of 105 °C. Furthermore, the sensor was also found to show 91% average selectivity when exposed toward harsher industrial gases such as NO, CO, CO2, and SO2 along with same concentrations of Hg(0) vapor in similar operating conditions. In fact, this is the first time a conductometric sensor is shown to have high selectivity toward Hg(0) vapor even in the presence of H2S. Overall results indicate that the developed sensor has immense potential to be used as accurate online Hg(0) vapor monitoring technology within industrial processes.

  17. A New Technique for the Retrieval of Near Surface Water Vapor Using DIAL Measurements

    Science.gov (United States)

    Ismail, Syed; Kooi, Susan; Ferrare, Richard; Winker, David; Hair, Johnathan; Nehrir, Amin; Notari, Anthony; Hostetler, Chris

    2015-01-01

    Water vapor is one of the most important atmospheric trace gas species and influences radiation, climate, cloud formation, surface evaporation, precipitation, storm development, transport, dynamics, and chemistry. For improvements in NWP (numerical weather prediction) and climate studies, global water vapor measurements with higher accuracy and vertical resolution are needed than are currently available. Current satellite sensors are challenged to characterize the content and distribution of water vapor in the Boundary Layer (BL) and particularly near the first few hundred meters above the surface within the BL. These measurements are critically needed to infer surface evaporation rates in cloud formation and climate studies. The NASA Langley Research Center Lidar Atmospheric Sensing Experiment (LASE) system, which uses the Differential Absorption Lidar (DIAL) technique, has demonstrated the capability to provide high quality water vapor measurements in the BL and across the troposphere. A new retrieval technique is investigated to extend these DIAL water vapor measurements to the surface. This method uses signals from both atmospheric backscattering and the strong surface returns (even over low reflectivity oceanic surfaces) using multiple gain channels to cover the large signal dynamic range. Measurements can be made between broken clouds and in presence of optically thin cirrus. Examples of LASE measurements from a variety of conditions encountered during NASA hurricane field experiments over the Atlantic Ocean are presented. Comparisons of retrieved water vapor profiles from LASE near the surface with dropsonde measurements show very good agreement. This presentation also includes a discussion of the feasibility of developing space-based DIAL capability for high resolution water vapor measurements in the BL and above and an assessment of the technology needed for developing this capability.

  18. Single Molecule DNA Detection with an Atomic Vapor Notch Filter

    CERN Document Server

    Uhland, Denis; Widmann, Matthias; Lee, Sang-Yun; Wrachtrup, Jörg; Gerhardt, Ilja

    2015-01-01

    The detection of single molecules has facilitated many advances in life- and material-sciences. Commonly, it founds on the fluorescence detection of single molecules, which are for example attached to the structures under study. For fluorescence microscopy and sensing the crucial parameters are the collection and detection efficiency, such that photons can be discriminated with low background from a labeled sample. Here we show a scheme for filtering the excitation light in the optical detection of single stranded labeled DNA molecules. We use the narrow-band filtering properties of a hot atomic vapor to filter the excitation light from the emitted fluorescence of a single emitter. The choice of atomic sodium allows for the use of fluorescent dyes, which are common in life-science. This scheme enables efficient photon detection, and a statistical analysis proves an enhancement of the optical signal of more than 15% in a confocal and in a wide-field configuration.

  19. Water vapor stable isotope observations from tropical Australia

    KAUST Repository

    Parkes, Stephen

    2015-04-01

    The response of the tropical hydrological cycle to anthropogenically induced changes in radiative forcing is one of the largest discrepancies between climate models. Paleoclimate archives of the stable isotopic composition of precipitation in the tropics indicate a relationship with precipitation amount that could be exploited to study past hydroclimate and improve our knowledge of how this region responds to changes in climate forcing. Recently modelling studies of convective parameterizations fitted with water isotopes and remote sensing of water vapor isotopes in the tropics have illustrated uncertainty in the assumed relationship with rainfall amount. Therefore there is a need to collect water isotope data in the tropics that can be used to evaluate these models and help identify the relationships between the isotopic composition of meteoric waters and rainfall intensity. However, data in this region is almost non-existent. Here we present in-situ water vapor isotopic measurements and the HDO retrievals from the co-located Total Column Carbon Observing Network (TCCON) site at Darwin in Tropical Australia. The Darwin site is interestingly placed within the tropical western pacific region and is impacted upon by a clear monsoonal climate, and key climate cycles including ENSO and Madden Julian Oscillations. The analysis of the data illustrated relationships between water vapor isotopes and humidity which demonstrated the role of precipitation processes in the wet season and air mass mixing during the dry season. Further the wet season observations show complex relationships between humidity and isotopes. A simple Rayleigh distillation model was not obeyed, instead the importance of rainfall re-evaporation in generating the highly depleted signatures was demonstrated. These data potentially provide a useful tool for evaluating model parameterizations in monsoonal regions as they demonstrate relationships with precipitation processes that cannot be observed with

  20. Reactions of acetone oxide stabilized Criegee intermediate with SO2, NO2, H2O and O3

    Science.gov (United States)

    Kukui, Alexandre; Chen, Hui; Xiao, Shan; Mellouki, Wahid; Daële, Veronique

    2015-04-01

    Atmospheric aerosol particles represent a critical component of the atmosphere, impacting global climate, regional air pollution, and human health. The formation of new atmospheric particles and their subsequent growth to larger sizes are the key processes for understanding of the aerosol effects. Sulphuric acid, H2SO4, has been identified to play the major role in formation of new atmospheric particles and in subsequent particle growth. Until recently the reaction of OH with SO2 has been considered as the only important source of H2SO4 in the atmosphere. However, recently it has been suggested that the oxidation of SO2 by Criegee biradicals can be a significant additional atmospheric source of H2SO4 comparable with the reaction of SO2 with OH. Here we present some results about the reactions of the acetone oxide stabilized Criegee intermediate, (CH3)2=OO, produced in the reaction of 2,3-dimethyl-butene (TME) with O3. The formation of the H2SO4 in the reaction of acetone oxide with SO2 was investigated in the specially constructed atmospheric pressure laminar flow reactor. The Criegee intermediate was generated by ozonolysis of TME. The H2SO4, generated by addition of SO2, was directly monitored with Chemical Ionization Mass Spectrometer (SAMU, LPC2E). Relative rates of reactions of acetone oxide with SO2, NO2, H2O and ozone were determined from the dependencies of the H2SO4 yield at different concentrations of the reactants. Atmospheric applications of the obtained results are discussed in relation to the importance of this additional H2SO4 formation pathway compared to the reaction of OH with SO2.

  1. High acetone-butanol-ethanol production in pH-stat co-feeding of acetate and glucose.

    Science.gov (United States)

    Gao, Ming; Tashiro, Yukihiro; Wang, Qunhui; Sakai, Kenji; Sonomoto, Kenji

    2016-08-01

    We previously reported the metabolic analysis of butanol and acetone production from exogenous acetate by (13)C tracer experiments (Gao et al., RSC Adv., 5, 8486-8495, 2015). To clarify the influence of acetate on acetone-butanol-ethanol (ABE) production, we first performed an enzyme assay in Clostridium saccharoperbutylacetonicum N1-4. Acetate addition was found to drastically increase the activities of key enzymes involved in the acetate uptake (phosphate acetyltransferase and CoA transferase), acetone formation (acetoacetate decarboxylase), and butanol formation (butanol dehydrogenase) pathways. Subsequently, supplementation of acetate during acidogenesis and early solventogenesis resulted in a significant increase in ABE production. To establish an efficient ABE production system using acetate as a co-substrate, several shot strategies were investigated in batch culture. Batch cultures with two substrate shots without pH control produced 14.20 g/L butanol and 23.27 g/L ABE with a maximum specific butanol production rate of 0.26 g/(g h). Furthermore, pH-controlled (at pH 5.5) batch cultures with two substrate shots resulted in not only improved acetate consumption but also a further increase in ABE production. Finally, we obtained 15.13 g/L butanol and 24.37 g/L ABE at the high specific butanol production rate of 0.34 g/(g h) using pH-stat co-feeding method. Thus, in this study, we established a high ABE production system using glucose and acetate as co-substrates in a pH-stat co-feeding system with C. saccharoperbutylacetonicum N1-4.

  2. Quaternary liquid/liquid equilibria of sodium sulfate, sodium sulfite and water with two solvents: Acetone and 2-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Schiozer, A.L.

    1994-03-01

    Aqueous solutions of sodium sulfate and sodium sulfite are produced from sodium carbonate in flue-gas scrubbers; recovery of these salts often requires multi-effect evaporators; however, a new energy-efficient unit operation called extractive crystallization has been shown to have reduced energy costs. In this process, an organic solvent is added to the aqueous salt solution to precipitate salt. Acetone is a suitable solvent for this process, better than 2-propanol. Liquid/liquid/solid equilibria for ternary systems containing a salt, water, and an organic solvent were measured. Systems investigated were sodium sulfite/water/acetone and sodium sulfite/water/2-propanol. Experiments were conducted at salt saturation covering a temperature range between the lower consolute temperature and 48.6{degrees}C. In the attempt to improve the extractive crystallization process for recovery of sodium sulfate from flue-gas scrubbers, attention was given to a feed containing a mixture of sodium sulfite and sodium sulfate. Liquid-liquid equilibria for quaternary systems containing two salts, water, and an organic solvent were experimentally determined at 35{degrees}C. The systems investigated were sodium sulfate/sodium sulfite/water/acetone and sodium sulfate/sodium sulfite/water/2propanol. The systems were studied at three salt ratios. For each salt ratio, experiments were conducted starting at saturation, water was then added until the one-phase region was reached. Mixtures of the two salts proved to have a small disadvantage relative to the 100 % sulfate feed process. Therefore, a sulfate-based extractive crystallization process is recommended.

  3. Optical microresonator based on hollow sphere with porous wall for chemical sensing.

    Science.gov (United States)

    Wang, Hanzheng; Yuan, Lei; Kim, Cheol-Woon; Han, Qun; Wei, Tao; Lan, Xinwei; Xiao, Hai

    2012-01-01

    A porous-wall hollow glass microsphere (PW-HGM) was investigated as an optical resonator for chemical vapor sensing. A single mode optical fiber taper was used to interrogate the microresonator. Adsorption of chemical molecules into the nanosized pores induced a refractive index change of the thin wall and thus a shift in its resonance spectrum. The PW-HGM resonator had shown higher vapor detection sensitivity in comparison with a solid microsphere under similar test conditions.

  4. Kinetic parameters of oscillating reaction of amino acid-BrO-3-Mn2+-H2SO4-acetone system

    Institute of Scientific and Technical Information of China (English)

    LI Zongxiao; YUAN Chunlan; NIE Fei

    2005-01-01

    The oscillating behavior of thirteen amino acids [leucine (Leu), threonine (Thr), arginine (Arg), lysine (Lys), histidine (His), alanine (Ala), glutamine (Glu), glycine (Gly), methionine (Met), cystine (Cys), tryptophan (Trp), serine (Ser) and tyrosine (Tyr)] in amino acid--Mn2+-H2SO4-acetone system is studied by using a potentiometric determination. With the help of the oscillatory induction period and oscillation period obtained by the oscillating wave, and Arrhenius equation, the kinetic parameters [the apparent activation energy (E) and pre-exponential constant (A)] and rate constant (k) of the above-mentioned oscillating reaction are estimated.

  5. El vapor de ruedas "Cid": de pionero de la navegación comercial a vapor a primer vapor hospital

    Directory of Open Access Journals (Sweden)

    O. González García

    Full Text Available La aparición de la máquina de vapor había hecho realidad el sueño de navegar sin depender de las fuerzas de la naturaleza. La carrera por lograr un vapor comercial eficiente había comenzado. Con retraso por la Guerra de la Independencia, España se incorporó a la carrera. Entre los primeros vapores comerciales estaba el vapor "Cid". En 1859, en la Guerra de África, ante la necesidad de una evacuación regular de bajas se designa al "Cid" como buque hospital, fue la primera vez en el mundo que se usó un vapor hospital. El Dr. Nicasio Landa fue el responsable de realizar la misión con una organización moderna, eficaz y ejemplar. Pronto los vapores de ruedas perdieron su batalla con los de hélice y el "Cid" quedó obsoleto. Sin embargo, a pesar de su corta vida operativa, poco más de quince años, escribió una importante página en la historia de la navegación en España.

  6. Analytical modeling of the subsurface volatile organic vapor concentration in vapor intrusion.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2014-01-01

    The inhalation of volatile and semi-volatile organic compounds that intrude from a subsurface contaminant source into indoor air has become the subject of health and safety concerns over the last twenty years. Building subslab and soil gas contaminant vapor concentration sampling have become integral parts of vapor intrusion field investigations. While numerical models can be of use in analyzing field data and in helping understand the subslab and soil gas vapor concentrations, they are not widely used due to the perceived effort in setting them up. In this manuscript, we present a new closed-form analytical expression describing subsurface contaminant vapor concentrations, including subslab vapor concentrations. The expression was derived using Schwarz-Christoffel mapping. Results from this analytical model match well the numerical modeling results. This manuscript also explores the relationship between subslab and exterior soil gas vapor concentrations, and offers insights on what parameters need to receive greater focus in field studies.

  7. The combustion chemistry of a fuel tracer: Measured flame speeds and ignition delays and a detailed chemical kinetic model for the oxidation of acetone

    Energy Technology Data Exchange (ETDEWEB)

    Pichon, S.; Black, G.; Simmie, J.M.; Curran, H.J. [Combustion Chemistry Centre, National University of Ireland, Galway (Ireland); Chaumeix, N.; Yahyaoui, M. [Institut de Combustion Aerothermique Reactivite et Environnement, CNRS, Orleans (France); Donohue, R. [Information Technology, National University of Ireland, Galway (Ireland)

    2009-02-15

    Acetone ignition delay and stretch-free laminar flame speed measurements have been carried out and a kinetic model has been developed to simulate these and literature data for acetone and for ketene, which was found to be an important intermediate in its oxidation. The mechanism has been based on one originally devised for dimethyl ether and modified through validation of the hydrogen, carbon monoxide and methane sub-mechanisms. Acetone oxidation in argon was studied behind reflected shock waves in the temperature range 1340-1930 K, at 1 atm and at equivalence ratios of 0.5, 1 and 2; it is also shown that the addition of up to 15% acetone to a stoichiometric n-heptane mixture has no effect on the measured ignition delay times. Flame speeds at 298 K and 1 atm of pure acetone in air were measured in a spherical bomb; a maximum flame speed of {proportional_to}35 cm s{sup -1} at {phi}=1.15 is indicated. (author)

  8. An Optimized Trichloroacetic Acid/Acetone Precipitation Method for Two-Dimensional Gel Electrophoresis Analysis of Qinchuan Cattle Longissimus Dorsi Muscle Containing High Proportion of Marbling.

    Directory of Open Access Journals (Sweden)

    Ruijie Hao

    Full Text Available Longissimus dorsi muscle (LD proteomics provides a novel opportunity to reveal the molecular mechanism behind intramuscular fat deposition. Unfortunately, the vast amounts of lipids and nucleic acids in this tissue hampered LD proteomics analysis. Trichloroacetic acid (TCA/acetone precipitation is a widely used method to remove contaminants from protein samples. However, the high speed centrifugation employed in this method produces hard precipitates, which restrict contaminant elimination and protein re-dissolution. To address the problem, the centrifugation precipitates were first grinded with a glass tissue grinder and then washed with 90% acetone (TCA/acetone-G-W in the present study. According to our result, the treatment for solid precipitate facilitated non-protein contaminant removal and protein re-dissolution, ultimately improving two-dimensional gel electrophoresis (2-DE analysis. Additionally, we also evaluated the effect of sample drying on 2-DE profile as well as protein yield. It was found that 30 min air-drying did not result in significant protein loss, but reduced horizontal streaking and smearing on 2-DE gel compared to 10 min. In summary, we developed an optimized TCA/acetone precipitation method for protein extraction of LD, in which the modifications improved the effectiveness of TCA/acetone method.

  9. Suppressive effects of acetone extract from the stem bark of three Acacia species on nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophage cells

    Institute of Scientific and Technical Information of China (English)

    Kandhasamy Sowndhararajan; Rameshkumar Santhanam; Sunghyun Hong; Jin-Woo Jhoo; Songmun Kim

    2016-01-01

    Objective: To compare the inhibitory effects of acetone extracts from the stem bark of three Acacia species(Acacia dealbata, Acacia ferruginea and Acacia leucophloea) on nitric oxide production.Methods: The lipopolysaccharide(LPS)-stimulated RAW 264.7 macrophage cells were used to investigate the regulatory effect of acetone extracts of three Acacia stem barks on nitric oxide production and the expression of inducible nitric oxide synthase,cyclooxygenase-2 and tumor necrosis factor-a. Further, the phenolic profile of acetone extracts from the Acacia barks was determined by liquid chromatography-mass spectrometry/mass spectrometry analysis.Results: All the three extracts significantly decreased LPS-induced NO production as well as the expression of inducible nitric oxide synthase, cyclooxygenase-2 and tumor necrosis factor-a in a concentration dependent manner(25, 50 and 75 mg/m L). In the liquid chromatography-mass spectrometry/mass spectrometry analysis, acetone extract of Acacia ferruginea bark revealed the presence of 12 different phenolic components including quercetin, catechin, ellagic acid and rosmanol. However, Acacia dealbata and Acacia leucophloea barks each contained 6 different phenolic components.Conclusions: The acetone extracts of three Acacia species effectively inhibited the NO production in LPS-stimulated RAW 264.7 cells and the presence of different phenolic components in the bark extracts might be responsible for reducing the NO level in cells.

  10. Ultrathin Gas Permeable Oxide Membranes for Chemical Sensing: Nanoporous Ta2O5 Test Study

    Directory of Open Access Journals (Sweden)

    Alexander Imbault

    2015-09-01

    Full Text Available Conductometric gas sensors made of gas permeable metal oxide ultrathin membranes can combine the functions of a selective filter, preconcentrator, and sensing element and thus can be particularly promising for the active sampling of diluted analytes. Here we report a case study of the electron transport and gas sensing properties of such a membrane made of nanoporous Ta2O5. These membranes demonstrated a noticeable chemical sensitivity toward ammonia, ethanol, and acetone at high temperatures above 400 °C. Different from traditional thin films, such gas permeable, ultrathin gas sensing elements can be made suspended enabling advanced architectures of ultrasensitive analytical systems operating at high temperatures and in harsh environments.

  11. A membrane bioreactor for the simultaneous treatment of acetone, toluene, limonene and hexane at trace level concentrations.

    Science.gov (United States)

    Lebrero, R; Volckaert, D; Pérez, R; Muñoz, R; Van Langenhove, H

    2013-05-01

    The performance of a flat-membrane biofilm reactor (MBR) for the removal of acetone, toluene, limonene and hexane at concentrations ranging from 1.3 to 3.2 mg m(-3) was investigated at different gas residence times (GRT): 60, 30, 15 and 7 s. A preliminary abiotic test was conducted to assess the mass transport of the selected volatile organic compounds (VOCs) through the membrane. A reduced transport of limonene and hexane was observed with water present over the dense side of the membrane. The presence of a biofilm attached on the dense side of the membrane following bioreactor inoculation significantly increased VOC transport. High acetone and toluene removals (>93%) were recorded in the MBR regardless of the GRT. To remediate the low hexane removal performance (RE hexane-degrading consortium embedded in silicon oil was performed. Although hexane removal did not exceed 27%, this re-inoculation increased limonene removals up to 90% at a GRT of 7 s. The absence of inhibition of hexane biodegradation by substrate competition confirmed that hexane removal in the MBR was indeed limited by the mass transfer through the membrane. Despite the low carbon source spectrum and load, the microbiological analysis of the communities present in the MBR showed high species richness (Shannon-Wiener indices of 3.2-3.5) and a high pair-wise similarity (84-97%) between the suspended and the attached biomass.

  12. Hepatoprotective Activity of Aqueous Acetone Extract from Cienfuegosia digitata Cav. (Malvaceae Against Alcohol Hepatotoxicity in Albinos Wistar Rats

    Directory of Open Access Journals (Sweden)

    K. Konaté

    2012-06-01

    Full Text Available The present study was conducted to evaluate the hepatoprotective effects of aqueous acetone extract of Cienfuegosia digitata Cav. (Malvaceae an herbal plant used in Burkina Faso to treat traditionally liver disease in albinos Wistar rats. Animals received by gavage 25, 50 and 100 mg/kg body weight of extract daily for a period of 28 days. Control groups received alcohol 35% and water. In vivo administration of 35% ethanol for a period of 28 days in rats showed an activity of liver marker enzymes (AST, ALT, ALP and GGT, triglycerides, total cholesterol, total bilirubin and direct bilirubin in serum compared with rats which received water (control water. However, administration of 35% ethanol along with aqueous acetone extract decreased the activities of liver markers enzyme in serum comparatively to the control water group (p0.05 and p<0.05. This study revealed that Cienfuegosia digitata presents a hepatoprotective potential and this plant could be traditionally exploited in the treatment of liver disease particularly hepatitis B in Burkina Faso.

  13. Modifying the product pattern of Clostridium acetobutylicum: physiological effects of disrupting the acetate and acetone formation pathways.

    Science.gov (United States)

    Lehmann, Dörte; Hönicke, Daniel; Ehrenreich, Armin; Schmidt, Michael; Weuster-Botz, Dirk; Bahl, Hubert; Lütke-Eversloh, Tina

    2012-05-01

    Clostridial acetone-butanol-ethanol (ABE) fermentation is a natural source for microbial n-butanol production and regained much interest in academia and industry in the past years. Due to the difficult genetic accessibility of Clostridium acetobutylicum and other solventogenic clostridia, successful metabolic engineering approaches are still rare. In this study, a set of five knock-out mutants with defects in the central fermentative metabolism were generated using the ClosTron technology, including the construction of targeted double knock-out mutants of C. acetobtuylicum ATCC 824. While disruption of the acetate biosynthetic pathway had no significant impact on the metabolite distribution, mutants with defects in the acetone pathway, including both acetoacetate decarboxylase (Adc)-negative and acetoacetyl-CoA:acyl-CoA transferase (CtfAB)-negative mutants, exhibited high amounts of acetate in the fermentation broth. Distinct butyrate increase and decrease patterns during the course of fermentations provided experimental evidence that butyrate, but not acetate, is re-assimilated via an Adc/CtfAB-independent pathway in C. acetobutylicum. Interestingly, combining the adc and ctfA mutations with a knock-out of the phosphotransacetylase (Pta)-encoding gene, acetate production was drastically reduced, resulting in an increased flux towards butyrate. Except for the Pta-negative single mutant, all mutants exhibited a significantly reduced solvent production.

  14. Two-stage pervaporation process for effective in situ removal acetone-butanol-ethanol from fermentation broth.

    Science.gov (United States)

    Cai, Di; Hu, Song; Miao, Qi; Chen, Changjing; Chen, Huidong; Zhang, Changwei; Li, Ping; Qin, Peiyong; Tan, Tianwei

    2017-01-01

    Two-stage pervaporation for ABE recovery from fermentation broth was studied to reduce the energy cost. The permeate after the first stage in situ pervaporation system was further used as the feedstock in the second stage of pervaporation unit using the same PDMS/PVDF membrane. A total 782.5g/L of ABE (304.56g/L of acetone, 451.98g/L of butanol and 25.97g/L of ethanol) was achieved in the second stage permeate, while the overall acetone, butanol and ethanol separation factors were: 70.7-89.73, 70.48-84.74 and 9.05-13.58, respectively. Furthermore, the theoretical evaporation energy requirement for ABE separation in the consolidate fermentation, which containing two-stage pervaporation and the following distillation process, was estimated less than ∼13.2MJ/kg-butanol. The required evaporation energy was only 36.7% of the energy content of butanol. The novel two-stage pervaporation process was effective in increasing ABE production and reducing energy consumption of the solvents separation system.

  15. Crystal structure of bis[μ-bis(diphenylphosphanylmethane-κ2P:P′]digold(I dichloride acetone monosolvate monohydrate

    Directory of Open Access Journals (Sweden)

    Chien Ing Yeo

    2015-08-01

    Full Text Available In the title complex salt, [Au2{(C6H52PCH2P(C6H52}]Cl2·(CH32C=O·H2O, the dication forms an eight-membered {—PCPAu}2 ring with a transannular aurophilic interaction [Au...Au = 2.9743 (2 Å]. The ring approximates a flattened boat conformation, with the two methylene C atoms lying ca 0.58–0.59 Å above the least-squares plane defined by the Au2P4 atoms (r.m.s. deviation = 0.0849 Å. One Cl− anion functions as a weak bridge between the AuI atoms [Au...Cl = 2.9492 (13 and 2.9776 (12 Å]. The second Cl− anion forms two (waterO—H...Cl hydrogen bonds about a centre of inversion, forming a centrosymmetric eight-membered {...HOH...Cl}2 supramolecular square. Globally, the dications and loosely associated Cl− anions assemble into layers lying parallel to the ac plane, being connected by C—H...Cl,π(phenyl interactions. The supramolecular squares and solvent acetone molecules are sandwiched in the inter-layer region, being connected to the layers on either side by C—H...Cl,O(acetone interactions.

  16. Leidenfrost Vapor Layer Stabilization on Superhydrophobic Surfaces

    Science.gov (United States)

    Vakarelski, Ivan; Patankar, Neelesh; Marston, Jeremy; Chan, Derek; Thoroddsen, Sigurdur

    2012-11-01

    We have performed experiments to investigate the influence of the wettability of a superheated metallic sphere on the stability of a thin vapor layer during the cooling of a sphere immersed in water. For high enough sphere temperatures, a continuous vapor layer (Leidenfrost regime) is observed on the surface of non-superhydrophobic spheres, but below a critical sphere temperature the layer becomes unstable and explosively switches to nuclear boiling regime. In contrast, when the sphere surface is textured and superhydrophobic, the vapor layer is stable and gradually relaxes to the sphere surface until the complete cooling of the sphere, thus avoiding the nuclear boiling transition altogether. This finding could help in the development of heat exchange devices and of vapor layer based drag reducing technologies.

  17. Static Water Vapor Feed Electrolyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a static vapor feed electrolyzer utilizing an advanced bipolar plate that produces sub-saturated H2 and O2 is proposed. This novel bipolar design can...

  18. DMSP SSMT/2 - Atmospheric Water Vapor Profiler

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SSM/T-2 sensor is a five channel, total power microwave radiometer with three channels situated symmetrically about the 183.31 GHz water vapor resonance line and...

  19. Mobile Sensing Systems

    Directory of Open Access Journals (Sweden)

    Elsa Macias

    2013-12-01

    Full Text Available Rich-sensor smart phones have made possible the recent birth of the mobile sensing research area as part of ubiquitous sensing which integrates other areas such as wireless sensor networks and web sensing. There are several types of mobile sensing: individual, participatory, opportunistic, crowd, social, etc. The object of sensing can be people-centered or environment-centered. The sensing domain can be home, urban, vehicular… Currently there are barriers that limit the social acceptance of mobile sensing systems. Examples of social barriers are privacy concerns, restrictive laws in some countries and the absence of economic incentives that might encourage people to participate in a sensing campaign. Several technical barriers are phone energy savings and the variety of sensors and software for their management. Some existing surveys partially tackle the topic of mobile sensing systems. Published papers theoretically or partially solve the above barriers. We complete the above surveys with new works, review the barriers of mobile sensing systems and propose some ideas for efficiently implementing sensing, fusion, learning, security, privacy and energy saving for any type of mobile sensing system, and propose several realistic research challenges. The main objective is to reduce the learning curve in mobile sensing systems where the complexity is very high.

  20. Mobile Sensing Systems

    Science.gov (United States)

    Macias, Elsa; Suarez, Alvaro; Lloret, Jaime

    2013-01-01

    Rich-sensor smart phones have made possible the recent birth of the mobile sensing research area as part of ubiquitous sensing which integrates other areas such as wireless sensor networks and web sensing. There are several types of mobile sensing: individual, participatory, opportunistic, crowd, social, etc. The object of sensing can be people-centered or environment-centered. The sensing domain can be home, urban, vehicular… Currently there are barriers that limit the social acceptance of mobile sensing systems. Examples of social barriers are privacy concerns, restrictive laws in some countries and the absence of economic incentives that might encourage people to participate in a sensing campaign. Several technical barriers are phone energy savings and the variety of sensors and software for their management. Some existing surveys partially tackle the topic of mobile sensing systems. Published papers theoretically or partially solve the above barriers. We complete the above surveys with new works, review the barriers of mobile sensing systems and propose some ideas for efficiently implementing sensing, fusion, learning, security, privacy and energy saving for any type of mobile sensing system, and propose several realistic research challenges. The main objective is to reduce the learning curve in mobile sensing systems where the complexity is very high. PMID:24351637

  1. Analytical modeling of the subsurface volatile organic vapor concentration in vapor intrusion

    OpenAIRE

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The inhalation of volatile and semi-volatile organic compounds that intrude from a subsurface contaminant source into indoor air has become the subject of health and safety concerns over the last twenty years. Building subslab and soil gas contaminant vapor concentration sampling have become integral parts of vapor intrusion field investigations. While numerical models can be of use in analyzing field data and in helping understand the subslab and soil gas vapor concentrations, they are not w...

  2. Histochemical detection of GM1 ganglioside using cholera toxin-B subunit. Evaluation of critical factors optimal for in situ detection with special emphasis to acetone pre-extraction

    Directory of Open Access Journals (Sweden)

    T. Petr

    2010-05-01

    Full Text Available A comparison of histochemical detection of GM1 ganglioside in cryostat sections using cholera toxin B-subunit after fixation with 4% formaldehyde and dry acetone gave tissue-dependent results. In the liver no pre-treatment showed detectable differences related to GM1 reaction products, while studies in the brain showed the superiority of acetone pre-extraction (followed by formaldehyde, which yielded sharper images compared with the diffuse, blurred staining pattern associated with formaldehyde. Therefore, the aim of our study was to define the optimal conditions for the GM1 detection using cholera toxin B-subunit. Ganglioside extractability with acetone, the ever neglected topic, was tested comparing anhydrous acetone with acetone containing admixture of water. TLC analysis of acetone extractable GM1 ganglioside from liver sections did not exceed 2% of the total GM1 ganglioside content using anhydrous acetone at -20°C, and 4% at room temperature. The loss increased to 30.5% using 9:1 acetone/water. Similarly, photometric analysis of lipid sialic acid, extracted from dried liver homogenates with anhydrous acetone, showed the loss of gangliosides into acetone 3.0±0.3% only. The loss from dried brain homogenate was 9.5±1.1%. Thus, anhydrous conditions (dry tissue samples and anhydrous acetone are crucial factors for optimal in situ ganglioside detection using acetone pre-treatment. This ensures effective physical fixation, especially in tissues rich in polar lipids (precipitation, prevention of in situ diffusion, and removal of cholesterol, which can act as a hydrophobic blocking barrier.

  3. Vapor Pressure of 2-Chlorovinyl Dichloroarsine (Lewisite)

    Science.gov (United States)

    2009-02-01

    Streams of Compounds for Determining Vapor Pressure 11 3. Vapor Pressure of Lewisite I from Multiple Sources: Conant, Sumner, Lewis, Keyes, Price ...number of publications in the open literature by Green and Price ,4 Lewis and Perkins,5 Mann and Pope, Mohler and Polya7 and Gibson and Johnson.8...point. (2) Banks et al.,14 reported that during the fractional distillation of the reaction products of phenyl dichloroarsine and acetylene , 2

  4. Binary Schemes of Vapor Bubble Growth

    Science.gov (United States)

    Zudin, Yu. B.

    2015-05-01

    A problem on spherically symmetric growth of a vapor bubble in an infi nite volume of a uniformly superheated liquid is considered. A description of the limiting schemes of bubble growth is presented. A binary inertial-thermal bubble growth scheme characterized by such specifi c features as the "three quarters" growth law and the effect of "pressure blocking" in a vapor phase is considered.

  5. A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

    Science.gov (United States)

    McCarron, Daniel J; Hughes, Ifan G; Tierney, Patrick; Cornish, Simon L

    2007-09-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D(2) transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude.

  6. Vapor Hydrogen Peroxide Sterilization Certification

    Science.gov (United States)

    Chen, Fei; Chung, Shirley; Barengoltz, Jack

    For interplanetary missions landing on a planet of potential biological interest, United States NASA planetary protection currently requires that the flight system must be assembled, tested and ultimately launched with the intent of minimizing the bioload taken to and deposited on the planet. Currently the only NASA approved microbial reduction method is dry heat sterilization process. However, with utilization of such elements as highly sophisticated electronics and sensors in modern spacecraft, this process presents significant materials challenges and is thus an undesirable bioburden reduction method to design engineers. The objective of this work is to introduce vapor hydrogen peroxide (VHP) as an alternative to dry heat microbial reduction to meet planetary protection requirements. The VHP sterilization technology is widely used by the medical industry, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal of our study is determine the minimum VHP process conditions for PP acceptable microbial reduction levels. A series of experiments were conducted using Geobacillus stearothermophilus to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters -hydrogen peroxide concentration, number of pulses, and exposure duration -the investigation also considered the possible effect of environmental pa-rameters. Temperature, relative humidity, and material substrate effects on lethality were also studied. Based on the results, a most conservative D value was recommended. This recom-mended D value was also validated using VHP "hardy" strains that were isolated from clean-rooms and environmental populations collected from spacecraft relevant areas. The efficiency of VHP at ambient condition as well as VHP material compatibility will also be

  7. Bioeffects due to acoustic droplet vaporization

    Science.gov (United States)

    Bull, Joseph

    2015-11-01

    Encapsulated micro- and nano-droplets can be vaporized via ultrasound, a process termed acoustic droplet vaporization. Our interest is primarily motivated by a developmental gas embolotherapy technique for cancer treatment. In this methodology, infarction of tumors is induced by selectively formed vascular gas bubbles that arise from the acoustic vaporization of vascular microdroplets. Additionally, the microdroplets may be used as vehicles for localized drug delivery, with or without flow occlusion. In this talk, we examine the dynamics of acoustic droplet vaporization through experiments and theoretical/computational fluid mechanics models, and investigate the bioeffects of acoustic droplet vaporization on endothelial cells and in vivo. Early timescale vaporization events, including phase change, are directly visualized using ultra-high speed imaging, and the influence of acoustic parameters on droplet/bubble dynamics is discussed. Acoustic and fluid mechanics parameters affecting the severity of endothelial cell bioeffects are explored. These findings suggest parameter spaces for which bioeffects may be reduced or enhanced, depending on the objective of the therapy. This work was supported by NIH grant R01EB006476.

  8. Decoration of vertical graphene with aerosol nanoparticles for gas sensing

    Science.gov (United States)

    Cui, Shumao; Guo, Xiaoru; Ren, Ren; Zhou, Guihua; Chen, Junhong

    2015-08-01

    A facile method was demonstrated to decorate aerosol Ag nanoparticles onto vertical graphene surfaces using a mini-arc plasma reactor. The vertical graphene was directly grown on a sensor electrode using a plasma-enhanced chemical vapor deposition (PECVD) method. The aerosol Ag nanoparticles were synthesized by a simple vapor condensation process using a mini-arc plasma source. Then, the nanoparticles were assembled on the surface of vertical graphene through the assistance of an electric field. Based on our observation, nonagglomerated Ag nanoparticles formed in the gas phase and were assembled onto vertical graphene sheets. Nanohybrids of Ag nanoparticle-decorated vertical graphene were characterized for ammonia gas detection at room temperature. The vertical graphene served as the conductance channel, and the conductance change upon exposure to ammonia was used as the sensing signal. The sensing results show that Ag nanoparticles significantly improve the sensitivity, response time, and recovery time of the sensor.

  9. Gas sensing based on detection of light radiation from a region of modified cladding (nanocrystalline ZnO) of an optical fiber

    Science.gov (United States)

    Devendiran, S.; Sastikumar, D.

    2017-03-01

    A new type of fiber optic gas sensor is proposed by detecting a light radiated from a region of cladding modified with metal oxide (nanocrystalline ZnO). The intensity of radiated light is found to vary with different gasses and concentrations. Sensing characteristics are studied for ammonia, methanol, ethanol and acetone gasses. Gas sensitivity of the proposed sensor is compared with clad-modified fiber optic gas sensor. The new sensor exhibits enhanced sensitivity. Time response characteristics of the sensor are reported.

  10. Introduction to remote sensing

    CERN Document Server

    Cracknell, Arthur P

    2007-01-01

    Addressing the need for updated information in remote sensing, Introduction to Remote Sensing, Second Edition provides a full and authoritative introduction for scientists who need to know the scope, potential, and limitations in the field. The authors discuss the physical principles of common remote sensing systems and examine the processing, interpretation, and applications of data. This new edition features updated and expanded material, including greater coverage of applications from across earth, environmental, atmospheric, and oceanographic sciences. Illustrated with remotely sensed colo

  11. 33 CFR 154.808 - Vapor control system, general.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vapor control system, general... (CONTINUED) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154.808 Vapor control system, general. (a) A vapor control system design and installation must...

  12. Sense of moving

    DEFF Research Database (Denmark)

    Christensen, Mark Schram; Grünbaum, Thor

    2017-01-01

    In this chapter, we assume the existence of a sense of “movement activity” that arises when a person actively moves a body part. This sense is usually supposed to be part of sense of agency (SoA). The purpose of the chapter is to determine whether the already existing experimental paradigms can...

  13. The Formation of 2,2,4-Trimethyl-2,3-dihydro-1H-1,5-Benzodiazepine from 1,2-Diaminobenzene in the Presence of Acetone

    Directory of Open Access Journals (Sweden)

    Felix Odame

    2013-11-01

    Full Text Available In an attempt to synthesize a 2-substituted benzimidazole from the reaction of o-phenylenediamine and isophthalic acid in the presence of acetone and ethanol under microwave irradiation, a salt of the isophthalate ion and 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepin-5-ium ion was obtained. The condensation of two moles of acetone with the amine groups resulted in the formation of the benzodiazepine which crystallized as an iminium cation forming a salt with the isophthalate anion. The formation of benzodiazepine was also confirmed by performing the reaction of o-phenylenediamine with excess acetone in ethanol under conventional heating conditions. The compounds were characterized by NMR, FTIR, HRMS and microanalysis as well as X-ray crystallography. The reaction mechanism leading to the formation of benzodiazepine is also discussed.

  14. Increasing butanol/acetone ratio and solvent productivity in ABE fermentation by consecutively feeding butyrate to weaken metabolic strength of butyrate loop.

    Science.gov (United States)

    Li, Xin; Shi, Zhongping; Li, Zhigang

    2014-08-01

    In this study, we attempted to increase butanol/acetone ratio and total solvent productivity in ABE fermentations with corn- and cassava-based media, by consecutively feeding a small amount of butyrate/acetate during solventogenic phase to weaken the metabolic strengths in butyrate/acetate closed-loops. Consecutively feeding a small amount of butyrate (a total of 3.0 g/L-broth) is most effective in improving performance of corn-based ABE fermentations, as it simultaneously increased average butanol/acetone ratio by 23 % (1.92-2.36) and total solvent productivity by 16 % (0.355-0.410 g/L/h) as compared with those of control. However, the butyrate feeding strategy could not improve butanol/acetone ratio and total solvent productivity in cassava-based ABE fermentations, where the metabolic strength of butyrate closed-loop had already been very low.

  15. Methanol Gas-Sensing Properties of SWCNT-MIP Composites

    Science.gov (United States)

    Zhang, Jin; Zhu, Qin; Zhang, Yumin; Zhu, Zhongqi; Liu, Qingju

    2016-11-01

    The single-walled carbon nanotube (SWCNT)-molecularly imprinted powder (MIP) composites in this paper were prepared by mixing SWCNTs with MIPs. The structure and micrograph of the as-prepared SWCNTs-MIPs samples were characterized by XRD and TEM. The gas-sensing properties were tested through indirect-heating sensors based on SWCNT-MIP composites fabricating on an alumina tube with Au electrodes and Pt wires. The results showed that the structure of SWCNTs-MIPs is of orthogonal perovskite and the average particle size of the SWCNTs-MIPs was in the range of 10-30 nm. SWCNTs-MIPs exhibit good methanol gas-sensitive properties. At 90 °C, the response to 1 ppm methanol is 19.7, and the response to the interferent is lower than 5 to the other interferent gases (ethanol, formaldehyde, toluene, acetone, ammonia, and gasoline). The response time and recovery time are 50 and 58 s, respectively.

  16. Key Roles of Lewis Acid-base Pairs on ZnxZryOz in Direct Ethanol/Acetone to Isobutene Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junming; Baylon, Rebecca A.; Liu, Changjun; Mei, Donghai; Martin, Kevin J.; Venkitasubramanian, Padmesh; Wang, Yong

    2016-01-20

    The effects of surface acidity on the cascade ethanol-to-isobutene conversion were studied using ZnxZryOz catalysts. The ethanol-to-isobutene reaction was found to be limited by the secondary reaction of the key intermediate, acetone, namely the acetone-to-isobutene reaction. Although the catalysts with coexisting Brønsted acidity could catalyze the rate-limiting acetone-to-isobutene reaction, the presence of Brønsted acidity is also detrimental. First, secondary isobutene isomerization is favored, producing a mixture of butene isomers. Second, undesired polymerization and coke formation prevail, leading to rapid catalyst deactivation. Most importantly, both steady-state and kinetic reaction studies as well as FTIR analysis of adsorbed acetone-d6 and D2O unambiguously showed that a highly active and selective nature of balanced Lewis acid-base pairs was masked by the coexisting Brønsted acidity in the aldolization and self-deoxygenation of acetone to isobutene. As a result, ZnxZryOz catalysts with only Lewis acid-base pairs were discovered, on which nearly a theoretical selectivity to isobutene (~88.9%) was successfully achieved, which has never been reported before. Moreover, the absence of Brønsted acidity in such ZnxZryOz catalysts also eliminates the side isobutene isomerization and undesired polymerization/coke reactions, resulting in the production of high purity isobutene with significantly improved catalyst stability (< 2% activity loss after 200 h time-on-stream). This work not only demonstrates a balanced Lewis acid-base pair for the highly active and selective cascade ethanol-to-isobutene reaction, but also sheds light on the rational design of selective and robust acid-base catalyst for C-C coupling via aldolization reaction.

  17. Binary and ternary complexes of some inner transition metal ions with amino acids and acetyl acetone

    Science.gov (United States)

    Abu-Eittah, R. H.; Abdou, M. M.; Salem, M. B.

    1998-05-01

    The stability constants of the 1:1 and 1:2 (whenever possible) complexes formed between La3+, Ce3+, Th4+ and the amino acid anions L-alaninate, L-phenylalaninate and L-histidinate were determined by potentiometric titration in aqueous solution (25± 1 ^circC, I = 0.1 M KCl) and compared together with the constants previously determined. The various formation degree of the resulting M(L) and M(L)2 were determined. In order to relate the formation degree of M(L) and M(L)2 with the basicity of the amino acid anion (L^-), the acidity constants of the protonated amino acids, H2L^+, were also measured. The main results of this work prove that Th4+ ion forms the strongest complex with the studied amino acids. It is the only ion which forms a 1:2 complex. The heterocyclic ring of histidine plays a significant role in complexing with the studied metal ions as is clearly seen from the distribution of the degree of formation of the different complexes. The stability constants of the 1:1:1, 1:2:1 and 1:1:2 complexes formed between La3+, Ce3+, Th4+ and the anions L-alaninate, L-phenylalaninate and L-histidinate together with the acetyl acetonate ion were also determined following the same experimental set up used in the study of the simple complexes. The mixed-ligand complexes turned out to be very much stronger than the simple ligand complexes. Formation of a mixed ligand complex can be considered as a type of senergism. Les constantes de stabilité des complexes 1:1 et 2:2 (lorsque cela est possible) formés entre La3+, Ce3+, Th4+ et les anions aminoacides L-alaninate, L-phénylalaninate et L-histidinate ont été déterminées par dosage potentiométrique en solution aqueuse (25± 1 ^circC, I = 0,1 M KCl), et comparées à celles de la littérature. Les différents degrés de formation de M(L) et M(L)2 ont été quantifiés. Pour mettre en évidence la relation entre le degré de formation de M(L) et M(L)2 et la basicité des anions aminoacides (L^-), les constantes d

  18. Acetone-butanol fermatative production using cellobiose%纤维二糖发酵生产丙酮丁醇

    Institute of Scientific and Technical Information of China (English)

    熊莲; 潘微; 陈新德; 唐绿蓉; 马隆龙

    2012-01-01

    分别考察C.acetobutylicum 810705、810706以不同浓度的麸皮和玉米粉添加物作为营养元素,纤维二糖直接进行丙酮丁醇(ABE)发酵的结果,发现2株菌对于玉米粉和麸皮的浓度变化趋势一致,C.acetobutylicum 810706转化率较高.纤维二糖ABE发酵工艺条件表明:玉米粉添加量为总糖含量的30%、底物糖质量浓度60 g/L,pH 6.5、温度35℃时,C.acetobutylicum 810706转化率达到37.38%,总溶剂质量浓度22.43 g/L,比葡萄糖、木糖ABE发酵转化率高.模拟纤维素酶水解产物配制混合糖培养基,其溶剂转化率较单独的葡萄糖、木糖发酵的转化率高,为34.95%.对比纤维素酶水解条件,C.acetobutylicum 810706具有优良的纤维素酶水解同步糖化ABE发酵能力.%Fermantative production of acetone-butanol by C. Acetobutylicum 810705 and C. Acetobutylicum 810706 was studied from cellobiose with different additive amounts of bran and corn starch. The same variation tendency of solvent concentration and substrate conversion was testified, and substrate conversion of C. Acetobutylicum 810706 was a little higher. Corn starch was proved to be better nutritional supplements than bran, and the optimum additive ratio was 30% of total sugar. Based on the optimization of culture conditions, C. Acetobutylicum 810706 achieved a 37. 38% substrate conversion and 22. 43 g/L solvent concerntration, and it was better than fermantative production of acetone-butanol from glucose and xylose while cultured at 35 ℃ with 60 g/L sugar concentration of substrate and initial pH 6. 5. Mixed sugar substrate prepared by imitating the concentration of cellulose enzymatic hydrolysis was fermented. 34. 95% of substrate conversion was obtained, and it was higher than any single sugar. Results showed that C. Acetobutylicum 810706 had excellent potential of cellulose saccharified by enzymatic hydrolysis and acetone-butanol fermentation simultaneously.

  19. Enhanced Gas-Sensing Properties of the Hierarchical TiO₂ Hollow Microspheres with Exposed High-Energy {001} Crystal Facets.

    Science.gov (United States)

    Yang, Yong; Liang, Yan; Wang, Guozhong; Liu, Liangliang; Yuan, Cailei; Yu, Ting; Li, Qinliang; Zeng, Fanyan; Gu, Gang

    2015-11-11

    Anatase hierarchical TiO2 with innovative designs (hollow microspheres with exposed high-energy {001} crystal facets, hollow microspheres without {001} crystal facets, and solid microspheres without {001} crystal facets) were synthesized via a one-pot hydrothermal method and characterized. Based on these materials, gas sensors were fabricated and used for gas-sensing tests. It was found that the sensor based on hierarchical TiO2 hollow microspheres with exposed high-energy {001} crystal facets exhibited enhanced acetone sensing properties compared to the sensors based on the other two materials due to the exposing of high-energy {001} crystal facets and special hierarchical hollow structure. First-principle calculations were performed to illustrate the sensing mechanism, which suggested that the adsorption process of acetone molecule on TiO2 surface was spontaneous, and the adsorption on high-energy {001} crystal facets would be more stable than that on the normally exposed {101} crystal facets. Further characterization indicated that the {001} surface was highly reactive for the adsorption of active oxygen species, which was also responsible for the enhanced sensing performance. The present studies revealed the crystal-facets-dependent gas-sensing properties of TiO2 and provided a new insight into improving the gas sensing performance by designing hierarchical hollow structure with special-crystal-facets exposure.

  20. Influence of Soil Moisture on Soil Gas Vapor Concentration for Vapor Intrusion.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2013-10-01

    Mathematical models have been widely used in analyzing the effects of various environmental factors in the vapor intrusion process. Soil moisture content is one of the key factors determining the subsurface vapor concentration profile. This manuscript considers the effects of soil moisture profiles on the soil gas vapor concentration away from any surface capping by buildings or pavement. The "open field" soil gas vapor concentration profile is observed to be sensitive to the soil moisture distribution. The van Genuchten relations can be used for describing the soil moisture retention curve, and give results consistent with the results from a previous experimental study. Other modeling methods that account for soil moisture are evaluated. These modeling results are also compared with the measured subsurface concentration profiles in the U.S. EPA vapor intrusion database.

  1. Differentiation of Chemical Components in a Binary Solvent Vapor Mixture Using Carbon/Polymer Composite-Based Chemiresistors

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Sanjay V.; Jenkins, Mark W.; Hughes, Robert C.; Yelton, W. Graham; Ricco, Antonio J.

    1999-07-19

    We demonstrate a ''universal solvent sensor'' constructed from a small array of carbon/polymer composite chemiresistors that respond to solvents spanning a wide range of Hildebrand volubility parameters. Conductive carbon particles provide electrical continuity in these composite films. When the polymer matrix absorbs solvent vapors, the composite film swells, the average separation between carbon particles increases, and an increase in film resistance results, as some of the conduction pathways are broken. The adverse effects of contact resistance at high solvent concentrations are reported. Solvent vapors including isooctane, ethanol, dlisopropyhnethylphosphonate (DIMP), and water are correctly identified (''classified'') using three chemiresistors, their composite coatings chosen to span the full range of volubility parameters. With the same three sensors, binary mixtures of solvent vapor and water vapor are correctly classified, following classification, two sensors suffice to determine the concentrations of both vapor components. Polyethylene vinylacetate and polyvinyl alcohol (PVA) are two such polymers that are used to classify binary mixtures of DIMP with water vapor; the PVA/carbon-particle-composite films are sensitive to less than 0.25{degree}A relative humidity. The Sandia-developed VERI (Visual-Empirical Region of Influence) technique is used as a method of pattern recognition to classify the solvents and mixtures and to distinguish them from water vapor. In many cases, the response of a given composite sensing film to a binary mixture deviates significantly from the sum of the responses to the isolated vapor components at the same concentrations. While these nonlinearities pose significant difficulty for (primarily) linear methods such as principal components analysis, VERI handles both linear and nonlinear data with equal ease. In the present study the maximum speciation accuracy is achieved by an array

  2. Vapor scavenging by atmospheric aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, E.

    1996-05-01

    Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

  3. Thermodynamics and Kinetics of Silicate Vaporization

    Science.gov (United States)

    Jacobson, Nathan S.; Costa, Gustavo C. C.

    2015-01-01

    Silicates are a common class of materials that are often exposed to high temperatures. The behavior of these materials needs to be understood for applications as high temperature coatings in material science as well as the constituents of lava for geological considerations. The vaporization behavior of these materials is an important aspect of their high temperature behavior and it also provides fundamental thermodynamic data. The application of Knudsen effusion mass spectrometry (KEMS) to silicates is discussed. There are several special considerations for silicates. The first is selection of an appropriate cell material, which is either nearly inert or has well-understood interactions with the silicate. The second consideration is proper measurement of the low vapor pressures. This can be circumvented by using a reducing agent to boost the vapor pressure without changing the solid composition or by working at very high temperatures. The third consideration deals with kinetic barriers to vaporization. The measurement of these barriers, as encompassed in a vaporization coefficient, is discussed. Current measured data of rare earth silicates for high temperature coating applications are discussed. In addition, data on magnesium-iron-silicates (olivine) are presented and discussed.

  4. Explosive vapor detection payload for small robots

    Science.gov (United States)

    Stimac, Phil J.; Pettit, Michael; Wetzel, John P.; Haas, John W.

    2013-05-01

    Detection of explosive hazards is a critical component of enabling and improving operational mobility and protection of US Forces. The Autonomous Mine Detection System (AMDS) developed by the US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) is addressing this challenge for dismounted soldiers. Under the AMDS program, ARA has developed a vapor sampling system that enhances the detection of explosive residues using commercial-off-the-shelf (COTS) sensors. The Explosives Hazard Trace Detection (EHTD) payload is designed for plug-and-play installation and operation on small robotic platforms, addressing critical Army needs for more safely detecting concealed or exposed explosives in areas such as culverts, walls and vehicles. In this paper, we describe the development, robotic integration and performance of the explosive vapor sampling system, which consists of a sampling "head," a vapor transport tube and an extendable "boom." The sampling head and transport tube are integrated with the boom, allowing samples to be collected from targeted surfaces up to 7-ft away from the robotic platform. During sample collection, an IR lamp in the sampling head is used to heat a suspected object/surface and the vapors are drawn through the heated vapor transport tube to an ion mobility spectrometer (IMS) for detection. The EHTD payload is capable of quickly (less than 30 seconds) detecting explosives such as TNT, PETN, and RDX at nanogram levels on common surfaces (brick, concrete, wood, glass, etc.).

  5. Acute and Subacute Toxicity study of the Acetone Leaf extract of Centella asiatica in Experimental Animal Models

    Institute of Scientific and Technical Information of China (English)

    PK Chauhan; V Singh

    2012-01-01

    Objective: To evaluate acute and subacute toxicity of the acetone extract of Centella asiatica (Brahmi). Methods: Toxicity of Centella asiatica was evaluated in Swiss mice after ingestion of the extract during one day (acute model) and during 15 days (subacute model). The Biochemical parameters evaluated included creatinine, calcium, inorganic phosphorous, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were assessed using commercial kits. Results: The results of the present investigation revealed that the LD50 of the extract is higher than 4000mg/kg and subacute treatment did not shows any change in corporal weight and hematological parameters. However, a change in liver weight but not in hepatic enzymes was observed. This suggested that the liver function is not altered by Centella asiatica. Some changes in the creatinine content were observed but could not be relative with the extract dose.Conclusions:The results suggest that the plant seems to be destitute of toxic effects in mice.

  6. A comparison of the energy use of in situ product recovery techniques for the Acetone Butanol Ethanol fermentation.

    Science.gov (United States)

    Outram, Victoria; Lalander, Carl-Axel; Lee, Jonathan G M; Davis, E Timothy; Harvey, Adam P

    2016-11-01

    The productivity of the Acetone Butanol Ethanol (ABE) fermentation can be significantly increased by application of various in situ product recovery (ISPR) techniques. There are numerous technically viable processes, but it is not clear which is the most economically viable in practice. There is little available information about the energy requirements and economics of ISPR for the ABE fermentation. This work compares various ISPR techniques based on UniSim process simulations of the ABE fermentation. The simulations provide information on the process energy and separation efficiency, which is fed into an economic assessment. Perstraction was the only technique to reduce the energy demand below that of a batch process, by approximately 5%. Perstraction also had the highest profit increase over a batch process, by 175%. However, perstraction is an immature technology, so would need significant development before being integrated to an industrial process.

  7. Oil palm empty fruit bunch as alternative substrate for acetone-butanol-ethanol production by Clostridium butyricum EB6.

    Science.gov (United States)

    Ibrahim, Mohamad Faizal; Abd-Aziz, Suraini; Razak, Mohamad Nafis Abdul; Phang, Lai Yee; Hassan, Mohd Ali

    2012-04-01

    Acetone-butanol-ethanol (ABE) production from renewable resources has been widely reported. In this study, Clostridium butyricum EB6 was employed for ABE fermentation using fermentable sugar derived from treated oil palm empty fruit bunch (OPEFB). A higher amount of ABE (2.61 g/l) was produced in a fermentation using treated OPEFB as the substrate when compared to a glucose based medium that produced 0.24 g/l at pH 5.5. ABE production was increased to 3.47 g/l with a yield of 0.24 g/g at pH 6.0. The fermentation using limited nitrogen concentration of 3 g/l improved the ABE yield by 64%. The study showed that OPEFB has the potential to be applied for renewable ABE production by C. butyricum EB6.

  8. Ultrasound promoted catalytic liquid-phase dehydrogenation of isopropanol for Isopropanol-Acetone-Hydrogen chemical heat pump.

    Science.gov (United States)

    Xu, Min; Xin, Fang; Li, Xunfeng; Huai, Xiulan; Liu, Hui

    2015-03-01

    The apparent kinetic of the ultrasound assisted liquid-phase dehydrogenation of isopropanol over Raney nickel catalyst was determined in the temperature range of 346-353 K. Comparison of the effects of ultrasound and mechanical agitation on the isopropanol dehydrogenation was investigated. The ultrasound assisted dehydrogenation rate was significantly improved when relatively high power density was used. Moreover, the Isopropanol-Acetone-Hydrogen chemical heat pump (IAH-CHP) with ultrasound irradiation, in which the endothermic reaction is exposure to ultrasound, was proposed. A mathematical model was established to evaluate its energy performance in term of the coefficient of performance (COP) and the exergy efficiency, into which the apparent kinetic obtained in this work was incorporated. The operating performances between IAH-CHP with ultrasound and mechanical agitation were compared. The results indicated that the superiority of the IAH-CHP system with ultrasound was present even if more than 50% of the power of the ultrasound equipment was lost.

  9. L-Proline catalyzed aldol reactions between acetone and aldehydes in supercritical fluids:An environmentally friendly reaction procedure

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The direct asymmetric aldol reaction between various aldehydes and acetone catalyzed by L-proline catalyst was successfully carried out in supercritical CO2 (scCO2) and 1,1,1,2-tetrafluoroethane (R-134a) fluids.The enantioselectivity of 84% ee to the targeted product was achieved under 20 MPa,40 °C,and 15 mol% of the catalyst in supercritical CO2 (scCO2) fluid.The effects of reaction parameters,such as temperature,pressure,catalyst loading and different substituted aldehydes on both enantioselectivity and aldol yield were discussed.The titled reaction was also performed in 1,1,1,2-tetrafluoroethane,and the obtained results were compared with those in scCO2.This new reaction procedure provides an environmental asymmetric aldol reaction system as compared with that in organic solvents.

  10. Acetone-butanol-ethanol from sweet sorghum juice by an immobilized fermentation-gas stripping integration process.

    Science.gov (United States)

    Cai, Di; Wang, Yong; Chen, Changjing; Qin, Peiyong; Miao, Qi; Zhang, Changwei; Li, Ping; Tan, Tianwei

    2016-07-01

    In this study, sweet sorghum juice (SSJ) was used as the substrate in a simplified ABE fermentation-gas stripping integration process without nutrients supplementation. The sweet sorghum bagasse (SSB) after squeezing the fermentable juice was used as the immobilized carrier. The results indicated that the productivity of ABE fermentation process was improved by gas stripping integration. A total 24g/L of ABE solvents was obtained from 59.6g/L of initial sugar after 80h of fermentation with gas stripping. Then, long-term of fed-batch fermentation with continuous gas stripping was further performed. 112.9g/L of butanol, 44.1g/L of acetone, 9.5g/L of ethanol (total 166.5g/L of ABE) was produced in overall 312h of fermentation. At the same time, concentrated ABE product was obtained in the condensate of gas stripping.

  11. A Numerical Investigation of Vapor Intrusion — the Dynamic Response of Contaminant Vapors to Rainfall Events

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1 m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in

  12. A numerical investigation of vapor intrusion--the dynamic response of contaminant vapors to rainfall events.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2012-10-15

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in determining

  13. Direct effects of Moringa oleifera Lam (Moringaceae) acetone leaf extract on broiler chickens naturally infected with Eimeria species.

    Science.gov (United States)

    Ola-Fadunsin, Shola David; Ademola, Isaiah Oluwafemi

    2013-08-01

    Avian coccidiosis is one of the most important diseases of poultry and it is responsible for a large number of all broiler mortalities worldwide. The control of this disease relies mainly on the use of anticoccidial drugs. However, herbal preparations could be an alternative for the treatment against coccidiosis in chickens. The direct effects of Moringa oleifera acetone extracts on broiler chickens naturally infected with mixed Eimeria species was investigated to determine the relative efficacy of the extracts against coccidiosis in birds. The investigations were carried out in seven groups (ten chickens per group). The birds were given various doses (1.0, 2.0, 3.0, 4.0 and 5.0 g/kg body weight) of acetone extract of leaves of M. toltrazuril (positive control) and untreated (negative control). The extract was evaluated for anticoccidial activity by means of inhibition of oocyst output in faeces, faecal score, weight gain and mortality. Haematological indices were evaluated by standard methods. The group treated with 1.0 g/ kg body weight Moringa oleifera extract produced the least inhibitory effect on oocyst shed in the faeces (96.4%), while the groups treated with 2.0 g/kg, 3.0 g/kg, 4.0 g/kg and 5.0 g/kg body weight of the extract produced 97.4, 98.7, 99.1 and 99.8%, respectively. Body weight gains of infected chickens treated with the extract significantly improved (p Moringa oleifera leaves could find application in the treatment of avian coccidiosis in veterinary practice.

  14. Anthelmintic activity of acetone-water extracts against Haemonchus contortus eggs: interactions between tannins and other plant secondary compounds.

    Science.gov (United States)

    Vargas-Magaña, J J; Torres-Acosta, J F J; Aguilar-Caballero, A J; Sandoval-Castro, C A; Hoste, H; Chan-Pérez, J A

    2014-12-15

    This study aimed at (i) describing the effects of acetone-water extracts obtained from a range of different plant materials, on the hatching process of Haemonchus contortus eggs under in vitro conditions and (ii) identifying the role of tannins and other plant secondary compounds (PSC), on these AH effects by using polyvinylpolypyrrolidone (PVPP), an inhibitor of tannins and other polyphenols. An egg hatch assay (EHA) was used to determine the AH effect. Acetone-water (70:30) extracts from different foliages (Lysiloma latisiliquum, Laguncularia racemosa, Rizophora mangle, Avicennia germinans) and plant by-products (Theobroma cacao seed husk and pulp, and percolated Coffea arabica) were obtained. Fresh H. contortus eggs were incubated in PBS with increasing concentrations of each extract (0, 600, 1200, 2400 and 3600 μg/ml PBS). A general linear model was used to determine the dose effect of each extract. A mild ovicidal activity was only recorded for T. cacao extracts (seed husk and pulp). The main anthelmintic (AH) effect for all the extracts, except for C. arabica, was to block the eclosion of larvated eggs. The use of PVPP at 3600 μg/ml PBS showed that tannins of the L. racemosa extract were responsible for blocking eclosion of larvated eggs. Extracts of L. latisiliquum, A. germinans, T. cacao seed husk and pulp also blocked eclosion of larvated eggs but the addition of PVPP indicated that tannins were not responsible for that activity. In contrast, it suggested unfavorable interactions between polyphenols and other PSC contained in those extracts, limiting the AH effect on the egg hatching process. The present results suggest that the interactions between tannins and other PSC are complex and may reduce the AH effects against H. contortus eggs.

  15. Dew point fast measurement in organic vapor mixtures using quartz resonant sensor

    Science.gov (United States)

    Nie, Jing; Liu, Jia; Meng, Xiaofeng

    2017-01-01

    A fast dew point sensor has been developed for organic vapor mixtures by using the quartz crystal with sensitive circuits. The sensor consists of the quartz crystal and a cooler device. Proactive approach is taken to produce condensation on the surface of the quartz crystal, and it will lead to a change in electrical features of the quartz crystal. The cessation of oscillation was measured because this phenomenon is caused by dew condensation. Such a phenomenon can be used to detect the dew point. This method exploits the high sensitivity of the quartz crystal but without frequency measurement and also retains the stability of the resonant circuit. It is strongly anti-interfered. Its performance was evaluated with acetone-methanol mixtures under different pressures. The results were compared with the dew points predicted from the universal quasi-chemical equation to evaluate the performance of the proposed sensor. Though the maximum deviations of the sensor are less than 1.1 °C, it still has a fast response time with a recovery time of less than 10 s, providing an excellent dehumidifying performance.

  16. Water vapor release from biofuel combustion

    Science.gov (United States)

    Parmar, R. S.; Welling, M.; Andreae, M. O.; Helas, G.

    2008-03-01

    We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are compared to carbon in the biofuel. Fuel types included hardwood (oak and African musasa), softwood (pine and spruce, partly with green needles), and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7 on average, indicating the presence of water that is not chemically bound. This biofuel moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biofuel contributes distinctly to the water vapor in biomass burning emissions, and its influence on meteorology needs to be evaluated.

  17. Water vapor release from biomass combustion

    Science.gov (United States)

    Parmar, R. S.; Welling, M.; Andreae, M. O.; Helas, G.

    2008-10-01

    We report on the emission of water vapor from biomass combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are referenced to carbon in the biomass. The investigated fuel types include hardwood (oak and African musasa), softwood (pine and spruce, partly with green needles), and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7, indicating the presence of water that is not chemically bound. This non-bound biomass moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biomass contributes significantly to the water vapor in biomass burning emissions, and its influence on the behavior of fire plumes and pyro-cumulus clouds needs to be evaluated.

  18. Water vapor release from biofuel combustion

    Directory of Open Access Journals (Sweden)

    R. S. Parmar

    2008-03-01

    Full Text Available We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are compared to carbon in the biofuel. Fuel types included hardwood (oak and African musasa, softwood (pine and spruce, partly with green needles, and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7 on average, indicating the presence of water that is not chemically bound. This biofuel moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biofuel contributes distinctly to the water vapor in biomass burning emissions, and its influence on meteorology needs to be evaluated.

  19. Possible seasonal variability of mesospheric water vapor

    Science.gov (United States)

    Bevilacqua, R. M.; Schwartz, P. R.; Wilson, W. J.; Ricketts, W. B.; Howard, R. J.

    1985-01-01

    Ground-based spectral line measurements of the 22.2 GHz water vapor line in atmospheric emission were made at the Jet Propulsion Laboratory, which have been used to deduce the mesospheric water vapor profile. The measurements were made nearly continuously in the spring and early summer of 1984. The results indicate a temporal increase in the water vapor mixing ratio in the upper mesosphere from April through June. At 75 km, this increase is nearly by a factor of 2. Comparison of the present results with the results of a similar series of measurements made at the Haystack (radio astronomy) Observatory indicate that this temporal increase is part of a seasonal variation.

  20. CdSe quantum dots-poly(3-hexylthiophene) nanocomposite sensors for selective chloroform vapor detection at room temperature

    Science.gov (United States)

    Mondal, S. P.; Bera, S.; Narender, G.; Ray, S. K.

    2012-10-01

    Olive oil capped CdSe quantum dots (QDs) of average size ˜6 nm have been grown by a green chemical route synthesis for the fabrication of nanocomposite organic vapor sensing devices. A highly selective, room temperature chloroform vapor sensor has been fabricated using capped CdSe QDs and conducting polymer [poly(3-hexylthiophene)] nanocomposites. The nanocomposite sensor has been tested with the choloroform vapor of concentration varying from 100-1200 ppm at room temperature using different bias voltages. The recovery time of the sensor has been found to be improved on illumination with a monochromatic light of 600 nm, due to the photo-induced enhancement of charge transfer in nanocomposites.