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Sample records for week in-situ enhancement

  1. Chemically enhanced in situ recovery

    Sale, T. [CH2M Hill, Denver, CO (United States); Pitts, M.; Wyatt, K. [Surtek, Inc., Golden, CO (United States)] [and others

    1996-08-01

    Chemically enhanced recovery is a promising alternative to current technologies for management of subsurface releases of organic liquids. Through the inclusion of surfactants, solvents, polymers, and/or alkaline agents to a waterflood, the transport of targeted organic compounds can be increased and rates of recovery enhanced. By far, the vast majority of work done in the field of chemically enhanced recovery has been at a laboratory scale. The following text focuses on chemically enhanced recovery from a field application perspective with emphasis given to chlorinated solvents in a low permeability setting. While chlorinated solvents are emphasized, issues discussed are also relevant to organic liquids less dense than water such as petroleum products. Topics reviewed include: (1) Description of technology; (2) General technology considerations; (3) Low permeability media considerations; (4) Cost and reliability considerations; (5) Commercial availability; and (6) Case histories. Through this paper an appreciation is developed of both the potential and limitations of chemically enhanced recovery. Excluded from the scope of this paper is the in situ destruction of organic compounds through processes such as chemical or biological oxidation, chemically enhanced recovery of inorganic compounds, and ex situ soil treatment processes. 11 refs., 2 figs., 1 tab.

  2. Enhancing in situ bioremediation with pneumatic fracturing

    A major technical obstacle affecting the application of in situ bioremediation is the effective distribution of nutrients to the subsurface media. Pneumatic fracturing can increase the permeability of subsurface formations through the injection of high pressure air to create horizontal fracture planes, thus enhancing macro-scale mass-transfer processes. Pneumatic fracturing technology was demonstrated at two field sites at Tinker Air Force Base, Oklahoma City, Oklahoma. Tests were performed to increase the permeability for more effective bioventing, and evaluated the potential to increase permeability and recovery of free product in low permeability soils consisting of fine grain silts, clays, and sedimentary rock. Pneumatic fracturing significantly improved formation permeability by enhancing secondary permeability and by promoting removal of excess soil moisture from the unsaturated zone. Postfracture airflows were 500% to 1,700% higher than prefracture airflows for specific fractured intervals in the formation. This corresponds to an average prefracturing permeability of 0.017 Darcy, increasing to an average of 0.32 Darcy after fracturing. Pneumatic fracturing also increased free-product recovery rates of number 2 fuel from an average of 587 L (155 gal) per month before fracturing to 1,647 L (435 gal) per month after fracturing

  3. In situ hydrogenation of molybdenum oxide nanowires for enhanced supercapacitors

    Shakir, Imran

    2014-01-01

    In situ hydrogenation of orthorhombic molybdenum trioxide (α-MoO 3) nanowires has been achieved on a large scale by introducing alcohol during the hydrothermal synthesis for electrochemical energy storage supercapacitor devices. The hydrogenated molybdenum trioxide (H xMoO3) nanowires yield a specific capacitance of 168 F g-1 at 0.5 A g-1 and maintain 108 F g-1 at 10 A g-1, which is 36-fold higher than the capacitance obtained from pristine MoO3 nanowires at the same conditions. The electrochemical devices made with HxMoO3 nanowires exhibit excellent cycling stability by retaining 97% of their capacitance after 3000 cycles due to an enhanced electronic conductivity and increased density of hydroxyl groups on the surface of the MoO3 nanowires. This journal is © The Royal Society of Chemistry.

  4. Enhancement of in situ Remediation of Hydrocarbon Contaminated Soil

    Palmroth, M.

    2006-07-01

    Approximately 750 000 sites of contaminated land exist across Europe. The harmful chemicals found in Finnish soils include heavy metals, oil products, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorophenols, and pesticides. Petroleum and petroleum products enter soil from ruptured oil pipelines, land disposal of refinery products, leaking storage tanks and through accidents. PAH contamination is caused by the spills of coal tar and creosote from coal gasification and wood treatment sites in addition to oil spills. Cleanup of soil by bioremediation is cheaper than by chemical and physical processes. However, the cleaning capacity of natural attenuation and in situ bioremediation is limited. The purpose of this thesis was to find feasible options to enhance in situ remediation of hydrocarbon contaminants. The aims were to increase the bioavailability of the contaminants and microbial activity at the subsurface in order to achieve higher contaminant removal efficiency than by intrinsic biodegradation alone. Enhancement of microbial activity and decrease of soil toxicity during remediation were estimated by using several biological assays. The performance of these assays was compared in order to find suitable indicators to follow the progress of remediation. Phytoremediation and chemical oxidation are promising in situ techniques to increase the degradation of hydrocarbons in soil. Phytoremediation is plant-enhanced decontamination of soil and water. Degradation of hydrocarbons is enhanced in the root zone by increased microbial activity and through the detoxifying enzymes of plants themselves. Chemical oxidation of contaminants by Fenton's reaction can produce degradation products which are more biodegradable than the parent compounds. Fenton's reaction and its modifications apply solutions of hydrogen peroxide and iron for the oxidation of organic chemicals. The cost of oxidation can be reduced by aiming at partial instead of full oxidation of contaminants and by integrating the process to biological treatment, in which the formed degradation products can be biodegraded. Phytoremediation was used to remove fresh and aged petroleum hydrocarbons from soil, and modified FentonAEs reaction combined with biodegradation was used to remove aged creosote oil from soil. The effects of hydrocarbon aging, different plant species and soil amendments on the removal efficiency were studied in phytoremediation experiments. Lab-scale experiments were made with fresh diesel fuel, and a field study was made with aged hydrocarbons deriving from diesel fuel and lubricants. The used plant species were pine, poplar, a grass mixture and a legume mixture. The experiments with modified Fenton's treatment were carried out in soil columns, to which concentrated H{sub 2}O{sub 2} was added simulating in situ injection. Iron was not added since the soil was rich in iron. After FentonAEs treatment, the soil was incubated in serum bottles to determine the effects on bioavailability of PAHs by modified FentonAEs oxidation and to simulate the potential of intrinsic remediation. In addition to hydrocarbon analyses, the effects of both methods on soil microbial activities and toxicity were determined. In the presence of white clover and green pea, pine or poplar, 89 to 98 % of diesel fuel was removed, whereas the presence of grasses did not increase diesel fuel removal compared to treatment without plants, where up to 86 % of diesel fuel was removed. When diesel was applied to the trees for a second time, reduction in one month was 9 to 25 % higher than what was achieved after first month of first application. During the four growing season study with soil contaminated with aged hydrocarbon contaminants, the presence of vegetation did not increase hydrocarbon removal in unfertilised soil. Vegetation cover was denser in amended soil than in unfertilised soil. The addition of compost or NPK fertiliser enhanced hydrocarbon removal. However, the toxicity of aged hydrocarbon contaminated soil to Vibrio fischeri (a luminescent bacterium) and Enchytraeus albidus (enchytraeid) was low, and thus these toxicity indicators do not reliably reflect the progress of remediation of this aged hydrocarbon contaminated soil. All studied hydrocarbon contaminated soils contained metabolically active bacteria capable of degrading hydrocarbons. Both phytoremediation and modified Fenton's oxidation enhanced removal of hydrocarbons. However, the performance of these in situ remediation processes was case-dependent, the removal of aged hydrocarbon contaminants being more difficult than that of fresh hydrocarbon contaminants. Therefore, phytoremediation can be recommended to remove fresh diesel fuel contamination, but the removal of aged hydrocarbons requires other treatment methods, especially if remediation has to be achieved fast.

  5. Depth enhancement techniques for the in situ vitrification process

    In-situ vitrification (ISV) is a process by which electrical energy is supplied to a soil/waste matrix. The resulting Joule heat raises the temperature of the soil/waste matrix, producing a pool of molten soil. Since its inception, there have been many successful applications of the technology to both staged and actual waste sites. However, there has been some difficulty in extending the attainable treatment melt depth to levels greater than 5 m. Results obtained from application of two novel approaches for extending the ultimate treatment depth attainable with in-situ vitrification (ISV) are presented. In the first, the electrode design is modified to concentrate the Joule heat energy delivered to the soil/waste matrix in the lower region of the target melt zone. This electrode design has been dubbed the hot-tip electrode. Results obtained from both computational and experimental investigations of this design concept indicate that some benefit toward ISV depth enhancement was realized with these hot-tip electrodes. A second, alternative approach to extending process depth with ISV involves initiating the melt at depth and propagating it in either vertical direction (e.g., downward, upward, or both) to treat the target waste zone. A series of engineering-scale experiments have been conducted to assess the benefits of this approach. The results from these tests indicate that ISV may be effectively initiated and sustained using this subsurface start-up technique. A survey of these experiments and the associated results are presented herein, together with brief discussion of some considerations regarding setup and implementation of this subsurface start-up technique

  6. In situ enhanced soil mixing. Innovative technology summary report

    In Situ Enhanced Soil Mixing (ISESM) is a treatment technology that has been demonstrated and deployed to remediate soils contaminated with volatile organic compounds (VOCs). The technology has been developed by industry and has been demonstrated with the assistance of the U.S. Department of Energy's Office of Science and Technology and the Office of Environmental Restoration. The technology is particularly suited to shallow applications, above the water table, but can be used at greater depths. ISESM technologies demonstrated for this project include: (1) Soil mixing with vapor extraction combined with ambient air injection. [Contaminated soil is mixed with ambient air to vaporize volatile organic compounds (VOCs). The mixing auger is moved up and down to assist in removal of contaminated vapors. The vapors are collected in a shroud covering the treatment area and run through a treatment unit containing a carbon filter or a catalytic oxidation unit with a wet scrubber system and a high efficiency particulate air (HEPA) filter.] (2) soil mixing with vapor extraction combined with hot air injection [This process is the same as the ambient air injection except that hot air or steam is injected.] (3) soil mixing with hydrogen peroxide injection [Contaminated soil is mixed with ambient air that contains a mist of diluted hydrogen peroxide (H2O2) solution. The H2O2 solution chemically oxidizes the VOCs to carbon dioxide (CO2) and water.] (4) soil mixing with grout injection for solidification/stabilization [Contaminated soil is mixed as a cement grout is injected under pressure to solidify and immobilize the contaminated soil in a concrete-like form.] The soils are mixed with a single-blade auger or with a combination of augers ranging in diameter from 3 to 12 feet

  7. [Effects on phenol removal in the process of enhanced coagulation by manganese dioxide formed in situ].

    Zhang, Li-Zhu; Chen, Xiao-Dong; Ma, Jun; Yu, Min; Li, Xin

    2011-10-01

    Phenol was selected as a model compound. Factors, such as Ca2+, tannic acid, dose of kaolinite, dose of manganese dioxide formed in situ and pH, were invested on phenol removal in the process of enhanced coagulation by manganese dioxide formed in situ. Results showed that the addition of Ca2+ is beneficial for phenol removal. In the range of Ca2+ varied from 0 to 1.0 mmol x L(-1), the efficiency of phenol removal was enhanced more than 10%. Tannic acid can enhance phenol removal significantly when they are coexisted in water. As tannic acid was added to 10 mg x L(-1), phenol removal can be increased about 30% and 50% in the process of coagulation by AlCl3 and enhanced coagulation by manganese dioxide formed in situ, respectively. The dose of coagulant can be reduced in the process of enhanced coagulation with the addition of manganese dioxide formed in situ. The point of 1 mg x L(-1) manganese dioxide formed in situ linked with 30 mg x L(-1) AlCl3 can have the same phenol removal efficiency as the addition of 50 mg x L(-1) AlCl3. In the range of pH varied from 5 to 9, phenol can be removed with the high efficiency in the process of enhanced coagulation by manganese dioxide formed in situ. While under the strong acid condition and strong basic condition, phenol has lower removal efficiency. PMID:22279903

  8. Cost studies of thermally enhanced in situ soil remediation technologies

    This report describes five thermally enhanced technologies that may be used to remediate contaminated soil and water resources. The standard methods of treating these contaminated areas are Soil Vapor Extraction (SVE), Excavate ampersand Treat (E ampersand T), and Pump ampersand Treat (P ampersand T). Depending on the conditions at a given site, one or more of these conventional alternatives may be employed; however, several new thermally enhanced technologies for soil decontamination are emerging. These technologies are still in demonstration programs which generally are showing great success at achieving the expected remediation results. The cost savings reported in this work assume that the technologies will ultimately perform as anticipated by their developers in a normal environmental restoration work environment. The five technologies analyzed in this report are Low Frequency Heating (LF or Ohmic, both 3 and 6 phase AC), Dynamic Underground Stripping (DUS), Radio Frequency Heating (RF), Radio Frequency Heating using Dipole Antennae (RFD), and Thermally Enhanced Vapor Extraction System (TEVES). In all of these technologies the introduction of heat to the formation raises vapor pressures accelerating contaminant evaporation rates and increases soil permeability raising diffusion rates of contaminants. The physical process enhancements resulting from temperature elevations permit a greater percentage of volatile organic compound (VOC) or semi- volatile organic compound (SVOC) contaminants to be driven out of the soils for treatment or capture in a much shorter time period. This report presents the results of cost-comparative studies between these new thermally enhanced technologies and the conventional technologies, as applied to five specific scenarios

  9. Passive in-situ cometabolic biotreatment of gasoline and diesel in soil and groundwater: An electrokinetic enhanced bioremediation case history

    This paper presents the results of passive in-situ biotreatment of gasoline and diesel conducted at the subject facility in Hayward, California. Past spills of petroleum hydrocarbon fuels from an underground storage tank farm caused soil and shallow groundwater contamination in the clayey Bay Mud. The soil contamination was limited to a depth of about 10 feet with total petroleum hydrocarbons (TPH) concentration of 100 to 3,900 ppm. Due to the low permeability of the clayey Bay Mud, a passive in-situ biotreatment (PISB) system was designed and implemented for both soil and groundwater plumes. The PISB consisted of a system of electrokinetic, oxygen, nutrient and moisture enhancement units covering the soil and groundwater plumes. The electrokinetic system was installed to promote rapid migration of nutrient oxidant between electrodes to enhance the in-situ biodegradation processes. The gasoline and diesel in soil was remediated to less than 100 ppm of TPH. The TPH in groundwater was remediated to less than 10 ppm of TPH. The TPH in groundwater was remediated to less than 10 ppm. The groundwater remediation is in progress and the target cleanup levels were to be less than 10 ppm TPH and BTEX to less than 0.005, 1.0, 0.7 and 10.0 ppm respectively which are all below the MCL under the EPA primary drinking water standard. The total duration of this PISB was completed in less than 4 weeks

  10. In situ microbial systems for the enhancement of oil recovery

    Microbial Enhancement of Oil Recovery (MEOR) offers important new opportunities in the quest for increased oil production. It refers not to a single technique but rather to a collection of methodologies, analogous to parallel non-microbiological methods. MEOR has relevance for many type of production and reservoir problems detailed protocols: may be tailored specifically to a range of individual reservoir conditions. Microorganisms downhole can generate a wide variety of chemical products from inexpensive feed stocks: where these are more cost-effective than oil field chemicals injected from the surface, microbial methods may win widespread acceptance. MEOR methods must be defined precisely; in any particular reservoir procedure their proposed mechanism of action must be clearly understood and criteria established for evaluating their success. The most important applications for MEOR are 1) the production f insoluble or highly viscous polymer to control coning or to plug selectively high permeability thief zones and fractures, 2) the continuous generation of the active agents for polymer-and/or surfactant floods, 3) matrix acidisation and acid fracturing in carbonate rocks stimulate flows into production wells. All these approaches are currently actively been explored; several programmes for field-testing microbial EOR methods already exist, or are being readied, and rapid progress is likely within the next few years. (author)

  11. DEMONSTRATION BULLETIN: IN SITU STEAM ENHANCED RECOVERY PROCESS - HUGHES ENVIRONMENTAL SYSTEMS, INC.

    The Steam Enhanced Recovery Process (SERP) is designed to remove volatile compounds such as halogenated solvents and petroleum hydrocarbons, and semi-volatile compounds from contaminated soils in situ. The vapor pressures of most contaminants will increase by the addition of ste...

  12. Review of in situ derivatization techniques for enhanced bioanalysis using liquid chromatography with mass spectrometry.

    Baghdady, Yehia Z; Schug, Kevin A

    2016-01-01

    Accurate and specific analysis of target molecules in complex biological matrices remains a significant challenge, especially when ultra-trace detection limits are required. Liquid chromatography with mass spectrometry is often the method of choice for bioanalysis. Conventional sample preparation and clean-up methods prior to the analysis of biological fluids such as liquid-liquid extraction, solid-phase extraction, or protein precipitation are time-consuming, tedious, and can negatively affect target recovery and detection sensitivity. An alternative or complementary strategy is the use of an off-line or on-line in situ derivatization technique. In situ derivatization can be incorporated to directly derivatize target analytes in their native biological matrices, without any prior sample clean-up methods, to substitute or even enhance the extraction and preconcentration efficiency of these traditional sample preparation methods. Designed appropriately, it can reduce the number of sample preparation steps necessary prior to analysis. Moreover, in situ derivatization can be used to enhance the performance of the developed liquid chromatography with mass spectrometry-based bioanalysis methods regarding stability, chromatographic separation, selectivity, and ionization efficiency. This review presents an overview of the commonly used in situ derivatization techniques coupled to liquid chromatography with mass spectrometry-based bioanalysis to guide and to stimulate future research. PMID:26496130

  13. Transparent Raman-enhancing substrates for microbiological monitoring and in situ pollutant detection

    Wang, Huai-Hsien; Wang, Yuh-Lin [Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Cheng, Tian-You [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan (China); Sharma, Pradeep; Chiang, Fang-Yi; Chiu, Shirley Wen-Yu; Wang, Juen-Kai, E-mail: jkwang@ccms.ntu.edu.tw, E-mail: ylwang@pub.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China)

    2011-09-23

    Opaque Raman-enhancing substrates made of Ag nanoparticles on incompletely oxidized aluminum templates have been rendered transparent by an ion-drift process to complete the oxidation. The result shows that the transparent substrates exhibit high/uniform surface-enhanced Raman scattering (SERS) capability and good optical transmissivity, allowing for concurrent SERS characterization and high contrast transmission-mode optical imaging of S. aureus bacteria. We also demonstrate that the transparent substrates can used in conjunction with optical fibers as SERS sensors for in situ detection of malachite green down to 10{sup -9} M.

  14. Enhancing the design of in situ chemical barriers with multicomponent reactive transport modeling

    This paper addresses the need for systematic control of field-scale performance in the emplacement and operation of in situ chemical treatment barriers; in particular, it addresses the issue of how the local coupling of reaction kinetics and material heterogeneities at the laboratory or bench scale can be accurately upscaled to the field. The authors have recently developed modeling analysis tools that can explicitly account for all relevant chemical reactions that accompany the transport of reagents and contaminants through a chemically and physically heterogeneous subsurface rock or soil matrix. These tools are incorporated into an enhanced design methodology for in situ chemical treatment technologies, and the new methodology is demonstrated in the ongoing design of a field experiment for the In Situ Redox Manipulation (ISRM) project at the U.S. Department of Energy (DOE) Hanford Site. The ISRM design approach, which systematically integrates bench-scale and site characterization information, provides an ideal test for the new reactive transport techniques. The need for the enhanced chemistry capability is demonstrated by an example that shows how intra-aqueous redox kinetics can affect the transport of reactive solutes. Simulations are carried out on massively parallel computer architectures to resolve the influence of multiscale heterogeneities on multicomponent, multidimensional reactive transport. The technology will soon be available to design larger-scale remediation schemes

  15. IPCS: An integrated process control system for enhanced in-situ bioremediation

    To date, there has been little or no research related to process control of subsurface remediation systems. In this study, a framework to develop an integrated process control system for improving remediation efficiencies and reducing operating costs was proposed based on physical and numerical models, stepwise cluster analysis, non-linear optimization and artificial neural networks. Process control for enhanced in-situ bioremediation was accomplished through incorporating the developed forecasters and optimizers with methods of genetic algorithm and neural networks modeling. Application of the proposed approach to a bioremediation process in a pilot-scale system indicated that it was effective in dynamic optimization and real-time process control of the sophisticated bioremediation systems. - A framework of process control system was developed to improve in-situ bioremediation efficiencies and reducing operating costs

  16. Enhanced magnetic moment of ultrathin Co films measured by in situ electrodeposition in a SQUID

    Topolovec, Stefan; Krenn, Heinz; Würschum, Roland

    2016-01-01

    A special electrochemical cell enabling in situ electrodeposition in a SQUID magnetometer is applied to study the magnetic moment of ultrathin Co films during growth on an Au(111) substrate. The in situ electrodeposition approach allows a total elimination of the magnetic background signal of the substrate, thus the magnetic moment which arises exclusively from the deposited Co film could be measured with monolayer sensitivity. The average thickness of the deposited Co films dav as determined from the transferred charge can be adjusted easily by varying the parameters of the electrodeposition. Hence, the magnetic moment of Co thin films could be determined in absolute terms as a function of the film thickness dav. For the first few atomic layers an enhancement of the magnetic moment per Co atom compared to the bulk could be observed, which increases steadily with lowering dav, reaching up to 40%.

  17. One-week postoperative patency of lower extremity in situ bypass graft comparing epidural and general anesthesia

    Wiis, Julie Therese; Jensen-Gadegaard, Peter; Altintas, Ümit; Seidelin, Claus; Martusevicius, Robertas; Mantoni, Teit

    2014-01-01

    under epidural (n = 386) or general (n = 499) anesthesia. Thirty-day mortality (3.4% for epidural anesthesia versus 4.4% general anesthesia; P = 0.414) and comorbidity were comparable in the 2 groups. Graft occlusion within 7 days after surgery was reported in 93 patients, with a similar incidence in...... the epidural (10.1%) and general (10.8%) anesthesia groups (P = 0.730). When examining a subgroup of patients (n = 242) exposed to surgery on smaller vessels (femorodistal in situ bypass procedures, n = 253), the incidence of graft occlusion was also similar in the 2 groups at 14.0% and 9.......4%, respectively (P = 0.262). CONCLUSION: This retrospective study has shown that when graft patency is evaluated 7 days after surgery, anesthetic choice (epidural or general anesthesia) does not influence outcome....

  18. BCL11A enhancer dissection by Cas9-mediated in situ saturating mutagenesis.

    Canver, Matthew C; Smith, Elenoe C; Sher, Falak; Pinello, Luca; Sanjana, Neville E; Shalem, Ophir; Chen, Diane D; Schupp, Patrick G; Vinjamur, Divya S; Garcia, Sara P; Luc, Sidinh; Kurita, Ryo; Nakamura, Yukio; Fujiwara, Yuko; Maeda, Takahiro; Yuan, Guo-Cheng; Zhang, Feng; Orkin, Stuart H; Bauer, Daniel E

    2015-11-12

    Enhancers, critical determinants of cellular identity, are commonly recognized by correlative chromatin marks and gain-of-function potential, although only loss-of-function studies can demonstrate their requirement in the native genomic context. Previously, we identified an erythroid enhancer of human BCL11A, subject to common genetic variation associated with the fetal haemoglobin level, the mouse orthologue of which is necessary for erythroid BCL11A expression. Here we develop pooled clustered regularly interspaced palindromic repeat (CRISPR)-Cas9 guide RNA libraries to perform in situ saturating mutagenesis of the human and mouse enhancers. This approach reveals critical minimal features and discrete vulnerabilities of these enhancers. Despite conserved function of the composite enhancers, their architecture diverges. The crucial human sequences appear to be primate-specific. Through editing of primary human progenitors and mouse transgenesis, we validate the BCL11A erythroid enhancer as a target for fetal haemoglobin reinduction. The detailed enhancer map will inform therapeutic genome editing, and the screening approach described here is generally applicable to functional interrogation of non-coding genomic elements. PMID:26375006

  19. Enhancement of in situ biodegradation of organic compounds in groundwater by targeted pump and treat intervention

    Highlights: • Pumping reduces contaminant toxicity below levels which stimulate in situ biodegradation. • Pumping increases the mixing of background oxidants into the plume for anaerobic respiration. • Bacterial sulphate reduction is very sensitive to contaminant concentrations. • Stable isotope analysis confirms the contribution of different biodegradation processes. • Targeted pump and treatment can enhance the natural attenuation of complex plumes. - Abstract: This study demonstrates the value of targeted pump and treatment (PAT) to enhance the in situ biodegradation of organic contaminants in groundwater for improved restoration. The approach is illustrated for a plume of phenolic compounds in a sandstone aquifer, where PAT is used for hydraulic containment and removal of dissolved phase contaminants from specific depth intervals. Time-series analysis of the plume hydrochemistry and stable isotope composition of dissolved species (δ34S-SO4, δ13C-CH4, δ13C-TDIC (TDIC = Total Dissolved Inorganic Carbon)) in groundwater samples from high-resolution multilevel samplers were used to deduce changes in the relative significance of biodegradation processes and microbial activity in the plume, induced by the PAT system over 3 years. The PAT system has reduced the maximum contaminant concentrations (up to 6800 mg L−1 total phenols) in the plume by 50% to ∼70% at different locations. This intervention has (i) stimulated in situ biodegradation in general, with an approximate doubling of contaminant turnover based on TDIC concentration, which has increased from <200 mg L−1 to >350 mg L−1, (ii) enhanced the activity of SO4-reducing microorganisms (marked by a declining SO4 concentration with corresponding increase in SO4-δ34S to values >7–14‰V-CDT relative to background values of 1.9–6.5‰V-CDT), and (iii) where the TDIC increase is greatest, has changed TDIC-δ13C from values of −10 to −15‰V-PDB to ∼−20‰V-PDB. This indicates an increase in the relative importance of respiration processes (including denitrification and anaerobic methane oxidation, AMO) that yield 13C-depleted TDIC over fermentation and acetoclastic methanogenesis that yield 13C-enriched TDIC in the plume, leading to higher contaminant turnover. The plume fringe was found to be a zone of enhanced biodegradation by SO4-reduction and methanogenesis. Isotopically heavy methane compositions (up to −47.8‰V-PDB) and trends between δ13C-TDIC and δ13C-CH4 suggest that AMO occurs at the plume fringe where the contaminant concentrations have been reduced by the PAT system. Mass and isotope balances for inorganic carbon in the plume confirm the shift in spatial dominance of different biodegradation processes and significant increase in contribution of anaerobic respiration for contaminant biodegradation in zones targeted by the PAT system. The enhanced in situ biodegradation results from a reduction in organic contaminant concentrations in the plume to levels below those that formerly suppressed microbial activity, combined with increased supply of soluble electron acceptors (e.g. nitrate) into the plume by dispersion. An interruption of the PAT system and recovery of the dissolved organic contaminant concentrations towards former values highlights the dynamic nature of this enhancement on restoration and relatively rapid response of the aquifer microorganisms to changing conditions induced by the PAT system. In situ restoration using this combined engineered and passive approach has the potential to manage plumes of biodegradable contaminants over shorter timescales than would be possible using these methods independently. The application of PAT in this way strongly depends on the ability to ensure an adequate flux of dissolved electron acceptors into the plume by advection and dispersion, particularly in heterogeneous aquifers

  20. Enhanced production of β-glucosides by in-situ UDP-glucose regeneration.

    Huang, Fong-Chin; Hinkelmann, Jens; Hermenau, Alexandra; Schwab, Wilfried

    2016-04-20

    Glycosyltransferase (GT)-mediated methodology is recognized as one of the most practical approaches for large-scale production of glycosides. However, GT enzymes require a sugar nucleotide as donor substrate that must be generated in situ for preparative applications by recycling of the nucleotide moiety, e.g. by sucrose synthase (SUS). Three plant GT genes CaUGT2, VvGT14a, and VvGT15c and the fungal SbUGTA1 were successfully co-expressed with GmSUS from soybean in Escherichia coli BL21 and W cells. In vitro, the crude protein extracts prepared from four GT genes and GmSUS co-expressing cells were able to convert several small molecules to the corresponding glucosides, when sucrose and UDP were supplied. In addition, GmSUS was able to enhance the glucosylation efficiency and reduced the amount of supplying UDP-glucose. In the biotransformation system, co-expression of VvGT15c with GmSUS also improved the glucosylation of geraniol and enhanced the resistance of the cells against the toxic terpenol. GT-EcW and GTSUS-EcW cells tolerated up to 2mM geraniol and converted more than 99% of the substrate into the glucoside at production rates exceeding 40μgml(-1)h(-1). The results confirm that co-expression of SUS allows in situ regeneration of UDP-sugars and avoids product inhibition by UDP. PMID:26912290

  1. A Nanoplasmonic Strategy for Precision in-situ Measurements of Tip-enhanced Raman and Fluorescence Spectroscopy

    Meng, Lingyan; Sun, Mengtao; Chen, Jianing; Yang, Zhilin

    2016-01-01

    We theoretically investigate an optimized tip-film system that supports in-situ measurement of tip-enhanced Raman spectroscopy (TERS) and tip-enhanced fluorescence (TEF) of dye molecules. A scanning tunneling microscope (STM) is proposed to precisely control the tip-film distance, and thus in-situ measurement of TERS and TEF can be realized utilizing the specific surface plasmon resonance (SPR) properties of the tip-film system. Our calculations show that the optimized tip-film distance of 2?nm suggests a possibility of efficient acquisition of TERS and TEF in-situ. The calculated spatial resolution of TERS and spectral resolution of TEF can be down to 6.5?nm and 10?nm, respectively. Our theoretical results may find promising application in developing multiple functional nano-spectroscopy through which Raman and fluorescence can be measured in-situ at the nanoscale level.

  2. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs

  3. Observations of in-situ generated gravity waves during a stratospheric temperature enhancement (STE event

    A. J. Gerrard

    2011-05-01

    Full Text Available Observations of in-situ generated atmospheric gravity waves associated with a stratospheric temperature enhancement (STE are presented. Two sets of gravity waves are observed by molecular-aerosol lidar in conjunction with the early December 2000 STE event above Sondrestrom, Greenland. The first set of gravity waves shows downward phase progression with a vertical wavelength of ~8 km while the second set shows upward phase progression with a vertical wavelength of ~9 km. With estimates of the background wind fields from synoptic analyses, the various intrinsic gravity wave parameters of these two wave structures are found. The observed waves compare well to numerical modeling predictions, though the potential observation of a downward propagating wave would be unexpected.

  4. Enhancing field emission performance of aligned Si nanowires via in situ partial oxidization.

    Qian, Zhongjian; Liu, Xianyun; Yang, Ye; Yin, Qiaoxia

    2014-08-01

    Partially oxidized Si nanowire (NW) arrays have been achieved via a combinatorial process of selectively etching Si wafer to obtain vertically aligned single crystalline Si NW arrays and subsequent in situ partially oxidizing the as-etched bare Si NWs. The resultant Si products are Si-SiOx nanocable-like structures consisting of single-crystalline Si NW inner cores and outer shells of insulating SiOx. Field emission measurements demonstrate that surface partial oxidization enhances the field emission current of the as-etched bare Si NWs effectively, which can be ascribed to the outer shell of insulating SiOx that has small electron affinity (0.6-0.8 eV) and can protect Si NW inner cores. The results indicate that the partially oxidized Si NW arrays would act as the excellent field emitters in the future vacuum micro- and nano-electronic devices. PMID:25936088

  5. Microbial and Chemical Enhancement of In-Situ Carbon Mineralization in Geological Formation

    Matter, J.; Chandran, K.

    2013-05-31

    Predictions of global energy usage suggest a continued increase in carbon emissions and rising concentrations of CO{sub 2} in the atmosphere unless major changes are made to the way energy is produced and used. Various carbon capture and storage (CCS) technologies are currently being developed, but unfortunately little is known regarding the fundamental characteristics of CO{sub 2}-mineral reactions to allow a viable in-situ carbon mineralization that would provide the most permanent and safe storage of geologically-injected CO{sub 2}. The ultimate goal of this research project was to develop a microbial and chemical enhancement scheme for in-situ carbon mineralization in geologic formations in order to achieve long-term stability of injected CO{sub 2}. Thermodynamic and kinetic studies of CO{sub 2}-mineral-brine systems were systematically performed to develop the in-situ mineral carbonation process that utilizes organic acids produced by a microbial reactor. The major participants in the project are three faculty members and their graduate and undergraduate students at the School of Engineering and Applied Science and at the Lamont-Doherty Earth Observatory at Columbia University: Alissa Park in Earth and Environmental Engineering & Chemical Engineering (PI), Juerg Matter in Earth and Environmental Science (Co-PI), and Kartik Chandran in Earth and Environmental Engineering (Co-PI). Two graduate students, Huangjing Zhao and Edris Taher, were trained as a part of this project as well as a number of graduate students and undergraduate students who participated part-time. Edris Taher received his MS degree in 2012 and Huangjing Zhao will defend his PhD on Jan. 15th, 2014. The interdisciplinary training provided by this project was valuable to those students who are entering into the workforce in the United States. Furthermore, the findings from this study were and will be published in referred journals to disseminate the results. The list of the papers is given at the end of the report for reference.

  6. Enhanced sulfate formation by nitrogen dioxide: Implications from in situ observations at the SORPES station

    Xie, Yuning; Ding, Aijun; Nie, Wei; Mao, Huiting; Qi, Ximeng; Huang, Xin; Xu, Zheng; Kerminen, Veli-Matti; Petäjä, Tuukka; Chi, Xuguang; Virkkula, Aki; Boy, Michael; Xue, Likun; Guo, Jia; Sun, Jianning; Yang, Xiuqun; Kulmala, Markku; Fu, Congbin

    2015-12-01

    Investigating sulfate formation processes is important not only for air pollution control but also for understanding the climate system. Although the mechanisms of secondary sulfate production have been widely studied, in situ observational evidence implicating an important role of NO2 in SO2 oxidation in the real atmosphere has been rare. In this study, we report two unique cases, from an intensive campaign conducted at the Station for Observing Regional Processes of the Earth System (SORPES) in East China, showing distinctly different mechanisms of sulfate formation by NO2 and related nitrogen chemistry. The first case occurred in an episode of mineral dust mixed with anthropogenic pollutants and especially high concentrations of NOx. It reveals that NO2 played an important role, not only in surface catalytic reactions of SO2 but also in dust-induced photochemical heterogeneous reactions of NO2, which produced additional sources of OH radicals to promote new particle formation and growth. The second case was caused by aqueous oxidation of S(IV) by NO2 under foggy/cloudy conditions with high NH3 concentration. As a by-product, the formed nitrite enhanced HONO formation and further promoted the gas-phase formation of sulfate in the downwind area. This study highlights the effect of NOx in enhancing the atmospheric oxidizing capacity and indicates a potentially very important impact of increasing NOx on particulate pollution formation and regional climate change in East Asia.

  7. In situ analysis of dynamic laminar flow extraction using surface-enhanced Raman spectroscopy

    Wang, Fei; Wang, Hua-Lin; Qiu, Yang; Chang, Yu-Long; Long, Yi-Tao

    2015-12-01

    In this study, we performed micro-scale dynamic laminar flow extraction and site-specific in situ chloride concentration measurements. Surface-enhanced Raman spectroscopy was utilized to investigate the diffusion process of chloride ions from an oil phase to a water phase under laminar flow. In contrast to common logic, we used SERS intensity gradients of Rhodamine 6G to quantitatively calculate the concentration of chloride ions at specific positions on a microfluidic chip. By varying the fluid flow rates, we achieved different extraction times and therefore different chloride concentrations at specific positions along the microchannel. SERS spectra from the water phase were recorded at these different positions, and the spatial distribution of the SERS signals was used to map the degree of nanoparticle aggregation. The concentration of chloride ions in the channel could therefore be obtained. We conclude that this method can be used to explore the extraction behaviour and efficiency of some ions or molecules that enhance the SERS intensity in water or oil by inducing nanoparticle aggregation.

  8. SITE DEMONSTRATION OF ENHANCED IN SITU BIOREMEDIATION OF CHLORINATED AND NON-CHLORINATED ORGANIC COMPOUNDS IN FRACTURED BEDROCK

    A field demonstration of an enhanced in situ bioremediation technology was conducted between March 1998 and August 1999 at the ITT Industries Nithg Vision (ITTNV) Division plant in Roanoke, Virginia. The bioremediation process was evaluated for its effectiveness in treating both ...

  9. Induced metal redistribution and bioavailability enhancement in contaminated river sediment during in situ biogeochemical remediation.

    Liu, Tongzhou; Zhang, Zhen; Mao, Yanqing; Yan, Dickson Y S

    2016-04-01

    In situ sediment remediation using Ca(NO3)2 or CaO2 for odor mitigation and acid volatile sulfide (AVS) and organic pollutant (such as TPH and PAHs) removal was reported in many studies and fieldwork. Yet, the associated effects on metal mobilization and potential distortion in bioavailability were not well documented. In this study, contaminated river sediment was treated by Ca(NO3)2 and CaO2 in bench studies. Through the investigation of AVS removal, organic matter removal, the changes in sediment oxidation-reduction potential (ORP), microbial activity, and other indigenous parameters, the effects on metal bioavailability, bioaccessibility, and fraction redistribution in sediment were evaluated. The major mechanisms for sediment treated by Ca(NO3)2 and CaO2 are biostimulation with indigenous denitrifying bacteria and chemical oxidation, respectively. After applying Ca(NO3)2 and CaO2, the decreases of metal concentrations in the treated sediment were insignificant within a 35-day incubation period. However, the [SEMtot-AVS]/f OC increased near to the effective boundary of toxicity (100 μmol g(-1) organic carbon (OC)), indicating that both bioavailability and bioaccessibility of metals (Cu, Zn, and Ni) to benthic organisms are enhanced after remediation. Metals were found redistributed from relatively stable fractions (oxidizable and residual fractions) to weakly bound fractions (exchangeable and reducible fractions), and the results are in line with the enhanced metal bioavailability. Compared with Ca(NO3)2, CaO2 led to higher enhancement in metal bioavailability and bioaccessibility, and more significant metal redistribution, probably due to its stronger chemical reactive capacity to AVS and sediment organic matter. The reactions in CaO2-treated sediment would probably shift from physicochemical to biochemical heterotrophic oxidation for sediment organic matter degradation. Therefore, further investigation on the long-term metal redistribution and associated mobility as well as bioavailability is recommended. PMID:26620860

  10. Emerging Technologies for Enhanced In Situ Biodenitrification of Nitrate Contaminated Ground Water

    Faris, B.; Faris, B.

    2001-05-01

    One of the most pervasive ground water contaminants in the U.S. is nitrate. Traditional technologies for the remediation of nitrate-contaminated ground water are generally costly, lengthy, and often only partly effective. Enhanced in situ biodenitrification (EISBD) is a developing technology for remediating nitrate contaminated ground water and protecting public and domestic supply wells through in situ reduction. Natural denitrification processes have been well understood for some time. However, managing these processes to effectively remediated contaminated ground water in a timely fashion is innovative. EISBD is a remediation technology through which a carbon source (electron donor) is introduced to a nitrate-contaminated aquifer. Since many aquifers are aerobic, indigenous aerobic bacteria utilize the introduced carbon as a food source and oxygen serves as an electron acceptor. Oxygen in the aquifer becomes depleted, forming an anaerobic aquifer. When this occurs and an abundant carbon source is present, indigenous denitrifying bacteria proliferate and reduce nitrate to nitrogen gas through anaerobic respiration. EISBD technology deployments are currently underway for either remediation of sizable nitrate plumes in ground water systems or the reduction of nitrate contaminated ground water around public and/or domestic well fields dedicated to the production of drinking water. Regulatory enforcement of nitrate plumes has been limited. Pollution prevention programs are in place to limit further nitrate contamination, however, once a site becomes contaminated with nitrates above standards, the deployment of remediation technologies is lacking. With the development and further deployment of EISBD technologies, a cost-effective short-term tool is available for nitrate remediation. A multi-disciplinary team of the Interstate Technology Regulatory Cooperation published a Technology Overview guidance document on the emerging technology of EISBD. ITRC is a state-led, national coalition of personnel from the regulatory and technology programs from 40 states and the District of Columbia; federal agencies; and tribal, public, and industry stakeholders. ITRC is devoted to reducing barriers and speeding interstate deployment of better, more cost-effective, innovative environmental technologies.

  11. In-situ growth of zinc tungstate nanorods on graphene for enhanced photocatalytic performance

    Graphical abstract: Graphene/ZnWO4 (GZnWO4) nanorod composite photocatalysts were prepared by a simple one-step method. Namely, the reduction of graphene oxide and the growth of ZnWO4 nanorod occurred simultaneously in one single process. An enhancement in the photocatalytic activities were observed in GZnWO4 composites compared with pure ZnWO4 under UV light irradiation. - Highlights: GrapheneZnWO4 composite photocatalyst was prepared for the first time. The as-prepared composite photocatalysts show high activity for dye degradation. Effect of graphene amount on the photocatalytic activity was investigated. - Abstract: Graphenezinc tungstate (GZnWO4) hybrid photocatalysts were prepared by an in-situ growth method in which the reduction of graphene oxide (GO) and the growth of ZnWO4 crystals occurred simultaneously. The materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UVvis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. The photocatalytic activity was investigated by the degradation of dye methylene blue (MB). An enhancement in the photocatalytic activity was observed for GZnWO4 hybrids compared with pure ZnWO4 under UV light. This improvement was attributed to the following two reasons: increased migration efficiency of photo-induced electrons and increased adsorption activity for dye molecules. The effect of the amount of graphene on the photocatalytic activity was also investigated. Results showed that there was an optimum amount of 2%

  12. In-situ growth of zinc tungstate nanorods on graphene for enhanced photocatalytic performance

    Rao, Lei [College of Mechanical and Electronic Engineering, Hohai University, Changzhou, Jiangsu 213022 (China); Xu, Junling [College of Mechanical and Electronic Engineering, Hohai University, Changzhou, Jiangsu 213022 (China); Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098 (China); Ao, Yanhui, E-mail: andyao@hhu.edu.cn [College of Mechanical and Electronic Engineering, Hohai University, Changzhou, Jiangsu 213022 (China); Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098 (China); Wang, Peifang [College of Mechanical and Electronic Engineering, Hohai University, Changzhou, Jiangsu 213022 (China); Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098 (China)

    2014-09-15

    Graphical abstract: Graphene/ZnWO{sub 4} (GZnWO{sub 4}) nanorod composite photocatalysts were prepared by a simple one-step method. Namely, the reduction of graphene oxide and the growth of ZnWO{sub 4} nanorod occurred simultaneously in one single process. An enhancement in the photocatalytic activities were observed in GZnWO{sub 4} composites compared with pure ZnWO{sub 4} under UV light irradiation. - Highlights: GrapheneZnWO{sub 4} composite photocatalyst was prepared for the first time. The as-prepared composite photocatalysts show high activity for dye degradation. Effect of graphene amount on the photocatalytic activity was investigated. - Abstract: Graphenezinc tungstate (GZnWO{sub 4}) hybrid photocatalysts were prepared by an in-situ growth method in which the reduction of graphene oxide (GO) and the growth of ZnWO{sub 4} crystals occurred simultaneously. The materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UVvis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. The photocatalytic activity was investigated by the degradation of dye methylene blue (MB). An enhancement in the photocatalytic activity was observed for GZnWO{sub 4} hybrids compared with pure ZnWO{sub 4} under UV light. This improvement was attributed to the following two reasons: increased migration efficiency of photo-induced electrons and increased adsorption activity for dye molecules. The effect of the amount of graphene on the photocatalytic activity was also investigated. Results showed that there was an optimum amount of 2%.

  13. Enhanced spectroscopic gas sensors using in-situ grown carbon nanotubes

    De Luca, A.; Cole, M. T.; Hopper, R. H.; Boual, S.; Warner, J. H.; Robertson, A. R.; Ali, S. Z.; Udrea, F.; Gardner, J. W.; Milne, W. I.

    2015-05-01

    In this letter, we present a fully complementary-metal-oxide-semiconductor (CMOS) compatible microelectromechanical system thermopile infrared (IR) detector employing vertically aligned multi-walled carbon nanotubes (CNT) as an advanced nano-engineered radiation absorbing material. The detector was fabricated using a commercial silicon-on-insulator (SOI) process with tungsten metallization, comprising a silicon thermopile and a tungsten resistive micro-heater, both embedded within a dielectric membrane formed by a deep-reactive ion etch following CMOS processing. In-situ CNT growth on the device was achieved by direct thermal chemical vapour deposition using the integrated micro-heater as a micro-reactor. The growth of the CNT absorption layer was verified through scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The functional effects of the nanostructured ad-layer were assessed by comparing CNT-coated thermopiles to uncoated thermopiles. Fourier transform IR spectroscopy showed that the radiation absorbing properties of the CNT adlayer significantly enhanced the absorptivity, compared with the uncoated thermopile, across the IR spectrum (3 μm-15.5 μm). This led to a four-fold amplification of the detected infrared signal (4.26 μm) in a CO2 non-dispersive-IR gas sensor system. The presence of the CNT layer was shown not to degrade the robustness of the uncoated devices, whilst the 50% modulation depth of the detector was only marginally reduced by 1.5 Hz. Moreover, we find that the 50% normalized absorption angular profile is subsequently more collimated by 8°. Our results demonstrate the viability of a CNT-based SOI CMOS IR sensor for low cost air quality monitoring.

  14. Enhanced spectroscopic gas sensors using in-situ grown carbon nanotubes

    In this letter, we present a fully complementary-metal-oxide-semiconductor (CMOS) compatible microelectromechanical system thermopile infrared (IR) detector employing vertically aligned multi-walled carbon nanotubes (CNT) as an advanced nano-engineered radiation absorbing material. The detector was fabricated using a commercial silicon-on-insulator (SOI) process with tungsten metallization, comprising a silicon thermopile and a tungsten resistive micro-heater, both embedded within a dielectric membrane formed by a deep-reactive ion etch following CMOS processing. In-situ CNT growth on the device was achieved by direct thermal chemical vapour deposition using the integrated micro-heater as a micro-reactor. The growth of the CNT absorption layer was verified through scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The functional effects of the nanostructured ad-layer were assessed by comparing CNT-coated thermopiles to uncoated thermopiles. Fourier transform IR spectroscopy showed that the radiation absorbing properties of the CNT adlayer significantly enhanced the absorptivity, compared with the uncoated thermopile, across the IR spectrum (3??m15.5??m). This led to a four-fold amplification of the detected infrared signal (4.26??m) in a CO2 non-dispersive-IR gas sensor system. The presence of the CNT layer was shown not to degrade the robustness of the uncoated devices, whilst the 50% modulation depth of the detector was only marginally reduced by 1.5?Hz. Moreover, we find that the 50% normalized absorption angular profile is subsequently more collimated by 8. Our results demonstrate the viability of a CNT-based SOI CMOS IR sensor for low cost air quality monitoring

  15. Enhanced spectroscopic gas sensors using in-situ grown carbon nanotubes

    De Luca, A.; Cole, M. T.; Milne, W. I. [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Hopper, R. H.; Boual, S.; Ali, S. Z. [Cambridge CMOS Sensors Ltd., Deanland House, 160 Cowley Road, Cambridge CB4 0DL (United Kingdom); Warner, J. H.; Robertson, A. R. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Udrea, F. [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Cambridge CMOS Sensors Ltd., Deanland House, 160 Cowley Road, Cambridge CB4 0DL (United Kingdom); Gardner, J. W. [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2015-05-11

    In this letter, we present a fully complementary-metal-oxide-semiconductor (CMOS) compatible microelectromechanical system thermopile infrared (IR) detector employing vertically aligned multi-walled carbon nanotubes (CNT) as an advanced nano-engineered radiation absorbing material. The detector was fabricated using a commercial silicon-on-insulator (SOI) process with tungsten metallization, comprising a silicon thermopile and a tungsten resistive micro-heater, both embedded within a dielectric membrane formed by a deep-reactive ion etch following CMOS processing. In-situ CNT growth on the device was achieved by direct thermal chemical vapour deposition using the integrated micro-heater as a micro-reactor. The growth of the CNT absorption layer was verified through scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The functional effects of the nanostructured ad-layer were assessed by comparing CNT-coated thermopiles to uncoated thermopiles. Fourier transform IR spectroscopy showed that the radiation absorbing properties of the CNT adlayer significantly enhanced the absorptivity, compared with the uncoated thermopile, across the IR spectrum (3 μm–15.5 μm). This led to a four-fold amplification of the detected infrared signal (4.26 μm) in a CO{sub 2} non-dispersive-IR gas sensor system. The presence of the CNT layer was shown not to degrade the robustness of the uncoated devices, whilst the 50% modulation depth of the detector was only marginally reduced by 1.5 Hz. Moreover, we find that the 50% normalized absorption angular profile is subsequently more collimated by 8°. Our results demonstrate the viability of a CNT-based SOI CMOS IR sensor for low cost air quality monitoring.

  16. Enhancing the mechanical properties of cement paste by growing in-situ fiber reinforcement during hydration

    Constantinides, Margarita

    Efforts to improve the mechanical properties of concrete by modifying the cement paste matrix have focused entirely on strength enhancement. But the intrinsic brittleness of the cement paste matrix limits the possible improvement in the mechanical properties of concrete, and in particular the toughness of the material. Increasing the toughness of the cement paste matrix could lead to a reduction in flaw sensitivity by delaying unstable crack propagation. Consequently, the resistance of the material to cracking due to drying shrinkage, thermal shrinkage, expansive deterioration processes, and applied loads could increase considerably. The goal of this study was to grow in-situ fiber reinforcement in cement paste, a technique never before applied to cement-based materials, to enhance the toughness of the material. Ettringite, an existing, fiber-like hydration product was selected as the fiber reinforcement. Ettringite met all the necessary criteria to act as reinforcement in cement paste: adequate distribution in the matrix; adjustable volume fraction, aspect ratio and size; high stiffness along the fiber length; and finally compatibility with existing hydration products. Alkali-free accelerators were selected as the admixtures used to grow the ettringite in the cement paste. X-ray diffraction and scanning electron microscopy experiments were performed to study the volume fraction, distribution, size, and morphology of the ettringite crystals in the cement paste matrix (both plain and accelerator-containing). Mechanical tests (compression, splitting tension, flexural, compact tension) were used to evaluate the effect of the accelerators on the strength and toughness of cement paste. Microindentations on the surface of the cement paste matrix were performed to study the morphology of the cracks and the toughening mechanisms taking place. Through the characterization tests we identified that while more ettringite forms with the addition of the alkali-free accelerators, some of that ettringite forms in highly-porous inclusions distributed throughout the matrix. The compact tension specimen results showed that the accelerated specimens had a higher toughness and ductility compared to the control specimens. The dominant toughening mechanism identified was constrained microcracking, with the ettringite inclusions contributing to microcracking.

  17. Microwave assisted in situ synthesis of Ag–NaCMC films and their reproducible surface-enhanced Raman scattering signals

    Jiang, Tao; Li, Junpeng; Zhang, Li; Wang, Binbing; Zhou, Jun, E-mail: zhoujun@nbu.edu.cn

    2014-07-25

    Graphical abstract: Two kinds of Ag–NaCMC films for surface-enhanced Raman scattering (SERS) were prepared by conventional heating and microwave assisted in situ reduction methods without any additional capping or reducing agents. A relatively narrow and symmetric surface plasmon resonance band was observed in the absorption spectra of the films fabricated by the microwave assisted in situ reduction method. More uniform silver nanoparticles (NPs) implied by the symmetric absorption spectrum were further confirmed by the scanning electron microscopy images. After the simulation of the E-field intensity distribution around the silver NPs in NaCMC film, the Raman scattering enhancement factors (EFs) of these films were then investigated with 4-mercaptobenzoic acid molecule as a SERS reporter. Improved reproducibility of SERS signal was obtained in the microwave assisted synthesized Ag–NaCMC film, although it maintained an EF as only 1.11 × 10{sup 8}. The reproducible SERS signal of the Ag–NaCMC film is particularly attractive and this microwave assisted in situ reduction method is suitable for the production of excellent substrate for biosensor application. - Highlights: • The synthesis of Ag–NaCMC films was successfully fulfilled by a low-cost microwave method. • More uniform silver nanoparticles were observed in Ag–NaCMC film synthesized by microwave. • Improved reproducibility of SERS signal was obtained in microwave synthesized Ag–NaCMC film. - Abstract: Two kinds of Ag–NaCMC films for surface-enhanced Raman scattering (SERS) were prepared by conventional heating and microwave assisted in situ reduction methods without any additional capping or reducing agents. A relatively narrow and symmetric surface plasmon resonance band was observed in the absorption spectra of the films fabricated by the microwave assisted in situ reduction method. More uniform silver nanoparticles (NPs) implied by the symmetric absorption spectrum were further confirmed by the scanning electron microscopy images. After the simulation of the E-field intensity distribution around the silver NPs in NaCMC film, the Raman scattering enhancement factors (EFs) of these films were then investigated with 4-mercaptobenzoic acid molecule as a SERS reporter. Improved reproducibility of SERS signal was obtained in the microwave assisted synthesized Ag–NaCMC film, although it maintained an EF as only 1.11 × 10{sup 8}. The reproducible SERS signal of the Ag–NaCMC film is particularly attractive and this microwave assisted in situ reduction method is suitable for the production of excellent substrate for biosensor application.

  18. Microwave assisted in situ synthesis of Ag–NaCMC films and their reproducible surface-enhanced Raman scattering signals

    Graphical abstract: Two kinds of Ag–NaCMC films for surface-enhanced Raman scattering (SERS) were prepared by conventional heating and microwave assisted in situ reduction methods without any additional capping or reducing agents. A relatively narrow and symmetric surface plasmon resonance band was observed in the absorption spectra of the films fabricated by the microwave assisted in situ reduction method. More uniform silver nanoparticles (NPs) implied by the symmetric absorption spectrum were further confirmed by the scanning electron microscopy images. After the simulation of the E-field intensity distribution around the silver NPs in NaCMC film, the Raman scattering enhancement factors (EFs) of these films were then investigated with 4-mercaptobenzoic acid molecule as a SERS reporter. Improved reproducibility of SERS signal was obtained in the microwave assisted synthesized Ag–NaCMC film, although it maintained an EF as only 1.11 × 108. The reproducible SERS signal of the Ag–NaCMC film is particularly attractive and this microwave assisted in situ reduction method is suitable for the production of excellent substrate for biosensor application. - Highlights: • The synthesis of Ag–NaCMC films was successfully fulfilled by a low-cost microwave method. • More uniform silver nanoparticles were observed in Ag–NaCMC film synthesized by microwave. • Improved reproducibility of SERS signal was obtained in microwave synthesized Ag–NaCMC film. - Abstract: Two kinds of Ag–NaCMC films for surface-enhanced Raman scattering (SERS) were prepared by conventional heating and microwave assisted in situ reduction methods without any additional capping or reducing agents. A relatively narrow and symmetric surface plasmon resonance band was observed in the absorption spectra of the films fabricated by the microwave assisted in situ reduction method. More uniform silver nanoparticles (NPs) implied by the symmetric absorption spectrum were further confirmed by the scanning electron microscopy images. After the simulation of the E-field intensity distribution around the silver NPs in NaCMC film, the Raman scattering enhancement factors (EFs) of these films were then investigated with 4-mercaptobenzoic acid molecule as a SERS reporter. Improved reproducibility of SERS signal was obtained in the microwave assisted synthesized Ag–NaCMC film, although it maintained an EF as only 1.11 × 108. The reproducible SERS signal of the Ag–NaCMC film is particularly attractive and this microwave assisted in situ reduction method is suitable for the production of excellent substrate for biosensor application

  19. Prospects for Enhancing In Situ CO2 Mineralization in the Peridotite Aquifer of the Samail Ophiolite

    Paukert, A. N.; Matter, J. M.; Kelemen, P. B.; Shock, E.; Havig, J. R.

    2011-12-01

    The mantle peridotite section of the Samail Ophiolite in the Sultanate of Oman is a site of exceptionally well-developed, naturally occurring in situ CO2 mineralization and serves as a natural analog to an enhanced process. The evolution of groundwater along the CO2 mineralization pathway in ultramafic rocks is generally thought to follow a progression from surface water to shallow Mg-HCO3 groundwater to deep, alkaline Ca-OH groundwater [e.g., 1-3], but the timescale for this evolution is not known. In order to assess the prospects for an enhanced CO2 mineralization process, we must first have a better understanding of the time necessary to attain natural CO2 mineralization, as well as the rate-limiting factors for the natural process. To that end, a reactive transport model was developed to simulate water-rock interaction during the natural CO2 mineralization process in the peridotite of the Samail Ophiolite aquifer. The model was created using the geochemical code EQ3/6 v.8.0 4, and it tracks a two stage process in which surface water first interacts with peridotite in a shallow aquifer open to atmosphere, and then progresses to a closed system in which the water interacts with peridotite isolated from the atmosphere. The incorporation of dissolution kinetics for the primary minerals in peridotite allowed for an estimate of the time required for water to evolve to the extent seen in the field. Model results suggest that it may take less than 50 years to develop the shallow Mg-HCO3 water, but up to 5,600 years to form the deeper, alkaline Ca-OH water. Rock and water chemistry collected from the Samail Ophiolite and its aquifer were used to calibrate the model. The modeled water chemistry is in agreement with that seen in the field, suggesting that the model offers a fair representation of the natural CO2 mineralization process. The natural system model indicates that CO2 availability is the limiting factor for mineralization in the subsurface, so the model was expanded to include CO2 injection scenarios to determine if increasing the supply could enhance the rate of CO2 mineralization. Model results show that CO2 injection at 100 bar pCO2 and ambient temperature (30oC) would result in a 40x increase in CO2 mineralization over a 30 year period, while injection at 90oC would result in a 3,600x increase in mineralization. Thus far, these model results do not include hydrogeological parameters for the system. Porosity and permeability, and their change with secondary mineralization, may affect the injectivity of CO2 into the aquifer, so they should be included when modeling CO2 injection. However, permeability and porosity in fractured rock aquifers are notoriously complex and remain poorly constrained for the peridotite of the Samail Ophiolite; these parameters warrant further study prior to their inclusion in a model. Results from permeability tests on peridotite cores from the Samail Ophiolite will be presented, with emphasis on how these measurements contribute to our understanding of the potential for enhanced CO2 mineralization in the peridotite of the Samail Ophiolite aquifer. 1Barnes and O'Neil, 1969; 2Stanger, 1986; 3Bruni et al., 2002; 4Wolery and Jarek, 2003

  20. Tip-enhanced Raman spectroscopy (TERS) for in situ identification of indigo and iron gall ink on paper.

    Kurouski, Dmitry; Zaleski, Stephanie; Casadio, Francesca; Van Duyne, Richard P; Shah, Nilam C

    2014-06-18

    Confirmatory, nondestructive, and noninvasive identification of colorants in situ is of critical importance for the understanding of historical context and for the long-term preservation of cultural heritage objects. Although there are several established techniques for analyzing cultural heritage materials, there are very few analytical methods that can be used for molecular characterization when very little sample is available, and a minimally invasive approach is required. Tip-enhanced Raman spectroscopy (TERS) is a powerful analytical technique whose key features include high mass sensitivity, high spatial resolution, and precise positioning of the tip. In the current proof-of-concept study we utilized TERS to identify indigo dye and iron gall ink in situ on Kinwashi paper. In addition, TERS was used to identify iron gall ink on a historical document with handwritten text dated to the 19th century. We demonstrate that TERS can identify both of these colorants directly on paper. Moreover, vibrational modes from individual components of a complex chemical mixture, iron gall ink, can be identified. To the best of our knowledge, this is the first demonstration of in situ TERS for colorants of artistic relevance directly on historical materials. Overall, this work demonstrates the great potential of TERS as an additional spectroscopic tool for minimally invasive compositional characterization of artworks in situ and opens exciting new possibilities for cultural heritage research. PMID:24848305

  1. Enhanced catalytic performance of carbon supported palladium nanoparticles by in-situ synthesis for formic acid electrooxidation

    Yao, Shikui; Li, Guoqiang; Liu, Changpeng; Xing, Wei

    2015-06-01

    The development of facile, surfactant-free strategy for the scale-up production of catalysts with superior performance for energy science is an interesting challenge. Pd/C is synthesized using an in-situ method from PdO/C for formic acid electrooxidation based on the reducibility of formic acid. The morphology, composition and electrocatalytic properties are investigated using transmission electronmicroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, linear scan voltammograms (LSV) and chronoamperometry. The in-situ synthesized Pd nanoparticles show better distribution and smaller average particle size than the normally synthesized Pd/C, which indicates that the well-known Ostwald ripening is most limited in the synthesis process. The electrochemical measurements show that the Pd/C catalyst exhibits enhanced performance towards formic acid electrooxidation. For example, the peak current of the Pd/C catalyst is approximately three times that of the homemade Pd/C catalyst and twice as high as that of the commercial Pd/C catalyst in the LSV test. The in-situ synthesized Pd/C catalyst has potential application for direct formic acid fuel cells, and the in-situ route should be an effective strategy to synthesize high performance catalysts.

  2. IN-SITU CHEMICAL STABILIZATION OF METALS AND RADIONUCLIDES THROUGH ENHANCED ANAEROBIC REDUCTIVE PRECIPITATION

    Christopher C. Lutes; Angela Frizzell, PG; Todd A. Thornton; James M. Harrington

    2003-08-01

    The objective of this NETL sponsored bench-scale study was to demonstrate the efficacy of enhanced anaerobic reductive precipitation (EARP) technology for precipitating uranium using samples from contaminated groundwater at the Fernald Closure Project (FCP) in Cincinnati, Ohio. EARP enhances the natural biological reactions in the groundwater through addition of food grade substrates (typically molasses) to drive the oxidative-reductive potential of the groundwater to a lower, more reduced state, thereby precipitating uranium from solution. In order for this in-situ technology to be successful in the long term, the precipitated uranium must not be re-dissolved at an unacceptable rate once groundwater geochemical conditions return to their pretreatment, aerobic state. The approach for this study is based on the premise that redissolution of precipitated uranium will be slowed by several mechanisms including the presence of iron sulfide precipitates and coatings, and sorption onto fresh iron oxides. A bench-scale study of the technology was performed using columns packed with site soil and subjected to a continuous flow of uranium-contaminated site groundwater (476 {micro}g/L). The ''treated'' column received a steady stream of dilute food grade molasses injected into the contaminated influent. Upon attainment of a consistently reducing environment and demonstrated removal of uranium, an iron sulfate amendment was added along with the molasses in the influent solution. After a month long period of iron addition, the treatments were halted, and uncontaminated, aerobic, unamended water was introduced to the treated column to assess rebound of uranium concentrations. In the first two months of treatment, the uranium concentration in the treated column decreased to the clean-up level (30 {micro}g/L) or below, and remained there for the remainder of the treatment period. A brief period of resolubilization of uranium was observed as the treated column returned to aerobic conditions, but the concentration later returned to below the clean-up level. Speciation analysis was conducted on soil collected from the treated column after rebound testing. The experimental results show that: (a) The mass of uranium resolubilized in more than four months of column testing was much lower than the amount precipitated. (b) The majority of the uranium was precipitated in the first few inches of the treated column. The majority of the uranium precipitated was associated with iron oxides or in other immobile/sequestered phases. It is important to contrast this result with the results reported by Bryan (2003) who shows that most of the uranium associated with contaminated aquifer solids at Fernald under the existing natural attenuation/pump and treat with reinjection conditions is carbonate bound. Carbonate bound forms are traditionally seen as fairly mobile, but may not be under a calcite/dolomite saturated condition. Fernald is currently conducting further studies to investigate the mobility of the carbonate bound forms. (c) Though reoxidation concentrations from the bench-scale column exceeded 30 {micro}g/L for a time, they later returned to below this value. Effluent concentrations from the treated column are expected to over predict full-scale concentrations for reasons discussed in depth in the text. Finally, these results must be viewed in light of the site's ongoing pump-and-treat with reinjection system. There is reason to believe that although the pump-and-treat technology is currently effectively controlling the uranium plume and reducing the groundwater concentration, it may not be able to reach the treatment standard of 30 {micro}g/L within an economical operating lifetime and then maintain that concentration without rebound. This study suggests that Enhanced Anaerobic Reductive Precipitation can change the speciation and thus reduce the mobility of uranium at the site and expedite closure.

  3. In situ growth rate measurements during plasma-enhanced chemical vapour deposition of vertically aligned multiwall carbon nanotube films

    In situ laser reflectivity measurements are used to monitor the growth of multiwalled carbon nanotube (MWCNT) films grown by DC plasma-enhanced chemical vapour deposition (PECVD) from an iron catalyst film deposited on a silicon wafer. In contrast to thermal CVD growth, there is no initial increase in the growth rate; instead, the initial growth rate is high (as much as 10 ?m min-1) and then drops off rapidly to reach a steady level (2 ?m min-1) for times beyond 1 min. We show that a limiting factor for growing thick films of multiwalled nanotubes (MWNTs) using PECVD can be the formation of an amorphous carbon layer at the top of the growing nanotubes. In situ reflectivity measurements provide a convenient technique for detecting the onset of the growth of this layer

  4. In Situ Monitoring of Electrooxidation Processes at Gold Single Crystal Surfaces Using Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy.

    Li, Chao-Yu; Dong, Jin-Chao; Jin, Xi; Chen, Shu; Panneerselvam, Rajapandiyan; Rudnev, Alexander V; Yang, Zhi-Lin; Li, Jian-Feng; Wandlowski, Thomas; Tian, Zhong-Qun

    2015-06-24

    Identifying the intermediate species in an electrocatalytic reaction can provide a great opportunity to understand the reaction mechanism and fabricate a better catalyst. However, the direct observation of intermediate species at a single crystal surface is a daunting challenge for spectroscopic techniques. In this work, electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (EC-SHINERS) is utilized to in situ monitor the electrooxidation processes at atomically flat Au(hkl) single crystal electrode surfaces. We systematically explored the effects of crystallographic orientation, pH value, and anion on electrochemical behavior of intermediate (AuOH/AuO) species. The experimental results are well correlated with our periodic density functional theory calculations and corroborate the long-standing speculation based on theoretical calculations in previous electrochemical studies. The presented in situ electrochemical SHINERS technique offers a unique way for a real-time investigation of an electrocatalytic reaction pathway at various well-defined noble metal surfaces. PMID:26052930

  5. A new principle for rapid immunoassay of proteins based on in situ precipitate-enhanced ellipsometry.

    Robers, M.; Rensink, I.J.; Hack, C.E.; AARDEN, L. A.; Reutelingsperger, C.P.; Glatz, J.F.; Hermens, W T

    1999-01-01

    A new technique is presented that allows measurement of protein concentrations in the picomolar range with an assay time of only 10-20 min. The method is an enzyme-linked immunosorbent assay (ELISA), but uses in-situ ellipsometric measurement of a precipitating enzyme product instead of the usual colorimetric detection of accumulating enzyme product in solution. Quantitative validation was obtained by use of annexin V, a protein with high binding affinity for phosphatidylserine-containing pho...

  6. JV Task 59-Demonstration of Accelerated In Situ Contaminant Degradation by Vacuum-Enhanced Nutrient Distribution

    Jaroslav Solc

    2007-03-15

    The Energy & Environmental Research Center (EERC) conducted remediation of hydrocarbon-contaminated soils and groundwater at a former Mohler Oil site in Bismarck, North Dakota. The remedial strategy was based on the application of two innovative concepts: (1) design and deployment of the mobile extraction, treatment, and injection units to overcome site limitations associated with urban settings in high-traffic areas and (2) vacuum-controlled nutrient injection within and on the periphery of an induced hydraulic and pneumatic depression. Combined contaminant recovery since the beginning of the project in June 2003 totals over 13,600 lb ({approx}6,170 kg) of hydrocarbons, equivalent to 2176 gallons (8236 l) of product. In situ delivery of 1504 Ib (682 kg) of ionic nitrate and 540 Ib (245 kg) of dissolved oxygen translates into further reduction of about 489 Ib (222 kg) of benzene for the same period and provides for long-term stimulation of the natural attenuation process. In addition to contaminant recovered by extraction and reduced by in situ biodegradation, a total of 4136 Ib (1876 kg) of oxygen was delivered to the saturated zone, resulting in further in situ reduction of an estimated 1324 lb (600 kg) of dissolved-phase hydrocarbons. Based on the results of the EERC demonstration, the North Dakota Department of Health approved site abandonment and termination of the corrective action.

  7. A capillary-based probe for in situ detection of enhanced fluorescence signals

    A simple, compact, and high sensitivity capillary-based probe for the in situ detection of fluorescence signals with high sensitivity is demonstrated. A home-made singlemulti-mode fiber coupler that is coaxially aligned with the capillary-based probe provides for the transmission of excitation light and the collection and transmission of fluorescence. We propose a conceptually straightforward theoretical model to optimize the factors affecting the fluorescence-capture capability of the capillary-based probe. The fluorescence signal detected by fiber-optic spectroscopy non-linearly increases with the length of the capillary-based probe. In addition, the thicker the capillary tube wall is, the less the fluorescence signals determined are. The performance of the proposed probe is evaluated experimentally by measuring the fluorescence spectra of Cy5.5 dye and blue-green algae. The experimental results show that the proposed probe provides more than a ten-fold increase in fluorescence signal compared with direct measurements by a flat-tipped multi-mode fiber probe. The advantages of the capillary-based probe, which include its simple and compact structure, excellent light collection efficiency, requirement of small sample volume, and recoverability of samples, allow its wide application to in situ detection in the medical, forensic, biological, geological, and environmental fields with high sensitivity. (letter)

  8. A capillary-based probe for in situ detection of enhanced fluorescence signals

    Long, F.; Xiao, R.; Zhu, A. N.; Shi, H. C.; Wang, S. Q.

    2013-07-01

    A simple, compact, and high sensitivity capillary-based probe for the in situ detection of fluorescence signals with high sensitivity is demonstrated. A home-made single-multi-mode fiber coupler that is coaxially aligned with the capillary-based probe provides for the transmission of excitation light and the collection and transmission of fluorescence. We propose a conceptually straightforward theoretical model to optimize the factors affecting the fluorescence-capture capability of the capillary-based probe. The fluorescence signal detected by fiber-optic spectroscopy non-linearly increases with the length of the capillary-based probe. In addition, the thicker the capillary tube wall is, the less the fluorescence signals determined are. The performance of the proposed probe is evaluated experimentally by measuring the fluorescence spectra of Cy5.5 dye and blue-green algae. The experimental results show that the proposed probe provides more than a ten-fold increase in fluorescence signal compared with direct measurements by a flat-tipped multi-mode fiber probe. The advantages of the capillary-based probe, which include its simple and compact structure, excellent light collection efficiency, requirement of small sample volume, and recoverability of samples, allow its wide application to in situ detection in the medical, forensic, biological, geological, and environmental fields with high sensitivity.

  9. Enhanced visible-light induced degradation of benzene on Mg-ferrite/hematite/PANI nanospheres: In situ FTIR investigation

    Graphical abstract: The dramatic enhanced visible-light photocatalytic activity of Mg-ferrite/hematite nanospheres photocatalyst on benzene were obtained after hybridized by polyaniline (PANI) using the chemisorption method. The enhancement of photocatalytic degradation of benzene under visible-light irradiation was mainly ascribed to the high efficiency of charge separation induced by the hybrid effect of PANI and Mg-ferrite/hematite. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO2 is produced as the final product during the reaction process. Highlights: ► Mg-ferrite/hematite/PANI photocatalysts showed enhanced photocatalytic activity. ► Ethyl acetate, carboxylic acid and aldehyde were the intermediate products. ► CO2 was produced as the final product during the reaction process. ► The high efficiency of charge separation was mainly ascribed to the hybrid effect. - Abstract: The dramatic enhanced visible-light photocatalytic activity of Mg-ferrite/hematite nanospheres photocatalysts on benzene were obtained after hybridized by polyaniline (PANI) using the chemisorption method. The samples were characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectra and UV–Vis diffuse reflectance spectroscopy. The enhancement of photocatalytic degradation of benzene under visible-light irradiation was mainly ascribed to the high efficiency of charge separation induced by the hybrid effect of PANI and Mg-ferrite/hematite. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO2 is determined as the final product during the reaction process.

  10. Enhanced visible-light induced degradation of benzene on Mg-ferrite/hematite/PANI nanospheres: In situ FTIR investigation

    Shen, Yu [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028 (China); Zhao, Qidong [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Li, Xinyong, E-mail: xyli@dlut.edu.cn [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia); Yuan, Deling; Hou, Yang [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Liu, Shaomin, E-mail: shaomin.liu@curtin.edu.au [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)

    2012-11-30

    Graphical abstract: The dramatic enhanced visible-light photocatalytic activity of Mg-ferrite/hematite nanospheres photocatalyst on benzene were obtained after hybridized by polyaniline (PANI) using the chemisorption method. The enhancement of photocatalytic degradation of benzene under visible-light irradiation was mainly ascribed to the high efficiency of charge separation induced by the hybrid effect of PANI and Mg-ferrite/hematite. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO{sub 2} is produced as the final product during the reaction process. Highlights: Black-Right-Pointing-Pointer Mg-ferrite/hematite/PANI photocatalysts showed enhanced photocatalytic activity. Black-Right-Pointing-Pointer Ethyl acetate, carboxylic acid and aldehyde were the intermediate products. Black-Right-Pointing-Pointer CO{sub 2} was produced as the final product during the reaction process. Black-Right-Pointing-Pointer The high efficiency of charge separation was mainly ascribed to the hybrid effect. - Abstract: The dramatic enhanced visible-light photocatalytic activity of Mg-ferrite/hematite nanospheres photocatalysts on benzene were obtained after hybridized by polyaniline (PANI) using the chemisorption method. The samples were characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectra and UV-Vis diffuse reflectance spectroscopy. The enhancement of photocatalytic degradation of benzene under visible-light irradiation was mainly ascribed to the high efficiency of charge separation induced by the hybrid effect of PANI and Mg-ferrite/hematite. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO{sub 2} is determined as the final product during the reaction process.

  11. Enhanced visible-light photocatalytic activities of Ag3PO4/MWCNT nanocomposites fabricated by facile in situ precipitation method

    Highlights: • Ag3PO4/MWCNT composites were facilely fabricated via in situ precipitation method. • Ag3PO4/MWCNT composites exhibited enhanced visible-light photocatalytic activity. • Ag3PO4/MWCNT composites showed good photostability compared with Ag3PO4 particles. • Possible photocatalytic mechanism under visible-light irradiation was proposed. - Abstract: The Ag3PO4/MWCNT nanocomposites were facilely fabricated via in situ precipitation method by adding (NH4)2HPO4 into the mixture of multi-walled carbon nanotube (MWCNT) and AgNO3 solution under stirring. The as-prepared Ag3PO4/MWCNT nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), the Brunauer–Emmett–Teller surface area (BET) and UV–vis diffuse reflectance spectroscopy. The TEM results showed that the Ag3PO4 nanoparticles were distributed on the surface of MWCNT uniformly with an average diameter of 70 nm, indicating excellent loading result. The photocatalytic activities of Ag3PO4/MWCNT nanocomposites were investigated by degrading methylene blue (MB) and malachite green (MG) under visible-light irradiation. It was found that the Ag3PO4/MWCNT nanocomposite exhibited excellent photocatalytic performance with enhanced photocatalytic efficiency and good photostability compared with bare Ag3PO4. Furthermore, a possible mechanism for the photocatalytic oxidative degradation was also discussed

  12. Glycerol supplementation of the growth medium enhances in situ detoxification of furfural by Clostridium beijerinckii during butanol fermentation.

    Ujor, Victor; Agu, Chidozie Victor; Gopalan, Venkat; Ezeji, Thaddeus Chukwuemeka

    2014-01-01

    Lignocellulose-derived microbial inhibitors such as furfural and 5-hydroxymethyl furfural adversely affect fermentation of lignocellulosic biomass hydrolysates to fuels and chemicals due to their toxicity on fermenting microbes. To harness the potential of lignocellulose as a cheap source of fermentable sugars, in situ detoxification of furfural and other lignocellulose-derived microbial inhibitors is essential. To enhance in situ detoxification and tolerance of furfural by Clostridium beijerinckii NCIMB 8052 during acetone-butanol-ethanol (ABE) fermentation, the effect of glycerol on NADH/NADPH generation and ABE production by furfural (4, 5, and 6 g/L)-challenged cultures was investigated in this study. In all instances, beneficial outcomes were observed. For example, the fermentation medium supplemented with glycerol and subjected to 5 g/L furfural elicited up to 1.8- and 3-fold increases, respectively, in NADH and NADPH levels in C. beijerinckii 8052 relative to the control culture. These critical changes are the likely underpinnings for the glycerol-mediated 2.3-fold increase in the rate of detoxification of 5 g/L furfural, substrate consumption, and ABE production compared to the unsupplemented medium. Collectively, these results demonstrate that increased intracellular NADH/NADPH in C. beijerinckii 8052 due to glycerol utilization engenders favorable effects on many aspects of cellular metabolism, including enhanced furfural reduction and increased ABE production. PMID:24839212

  13. In-situ rf plasma treatment of multi-wall carbon nanotubes with various reactive gases for enhanced field emission

    Ahn, Kyoung Soo; Kim, Ji Hoon; Lee, Kyoung Nam; Lee, Chang Hyo; Kim, Chae Ok; Hong, Jin Pyo [Hanyang University, Seoul (Korea, Republic of); Jeon, Yu Jin; Cheong, Hyeon Sik [Sogang Unversity, Seoul (Korea, Republic of)

    2004-07-15

    Well-aligned multi-wall carbon nanotubes (MWNTs) were fabricated at a low temperature of 400 .deg. C by utilizing a radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWNTs were in-situ treated with external rf plasma sources, such as hydrogen (H{sub 2}) and ammonia (NH{sub 3}), in order to enhance the structural and electrical properties of the MWNTs. Structural properties of carbon nanotubes were investigated by using scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive spectrometry and transmission electron microscopy. Finally, the emission properties of the MWNTs treated with various gases were also measured, for application in field emission displays in the near future.

  14. Surface-enhanced laser desorption ionization time-of-flight mass spectrometry used to screen serum diagnostic markers of colon cancer recurrence in situ following surgery

    ZHOU, ZHONG-YIN; JI, Tuo; Luo, He-Sheng

    2015-01-01

    The aim of the present study was to identify specific serum biomarkers in patients with colon cancer recurrence in situ following surgery. The study was conducted at the Renmin Hospital of Wuhan University (Wuhan, China) between January 2012 and January 2014. Surface-enhanced laser desorption ionization time-of-flight mass spectrometry was used to compare and analyze the serum protein profiles of patients with (n=50) and patients without (n=50) recurrence in situ. Biomarker Wizard software wa...

  15. Enhancing RHIC luminosity capabilities with in-situ beam piple coating

    Herschcovitch,A.; Blaskiewicz, M.; Fischer, W.; Poole, H. J.

    2009-05-04

    Electron clouds have been observed in many accelerators, including the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory (BNL). They can limit the machine performance through pressure degradation, beam instabilities or incoherent emittance growth. The formation of electron clouds can be suppressed with beam pipe surfaces that have low secondary electron yield. At the same time, high wall resistivity in accelerators can result in levels of ohmic heating unacceptably high for superconducting magnets. This is a concern for the RHIC machine, as its vacuum chamber in the superconducting dipoles is made from relatively high resistivity 316LN stainless steel. The high resistivity can be addressed with a copper (Cu) coating; a reduction in the secondary electron yield can be achieved with a titanium nitride (TiN) or amorphous carbon (a-C) coating. Applying such coatings in an already constructed machine is rather challenging. We started developing a robotic plasma deposition technique for in-situ coating of long, small diameter tubes. The technique entails fabricating a device comprised of staged magnetrons and/or cathodic arcs mounted on a mobile mole for deposition of about 5 {micro}m (a few skin depths) of Cu followed by about 0.1 {micro}m of TiN (or a-C).

  16. In Situ Resource Utilization Technologies for Enhancing and Expanding Mars Scientific and Exploration Missions

    Sridhar, K. R.; Finn, J. E.

    2000-07-01

    The primary objectives of the Mars exploration program are to collect data for planetary science in a quest to answer questions related to Origins, to search for evidence of extinct and extant life, and to expand the human presence in the solar system. The public and political engagement that is critical for support of a Mars exploration program is based on all of these objectives. In order to retain and to build public and political support, it is important for NASA to have an integrated Mars exploration plan, not separate robotic and human plans that exist in parallel or in sequence. The resolutions stemming from the current architectural review and prioritization of payloads may be pivotal in determining whether NASA will have such a unified plan and retain public support. There are several potential scientific and technological links between the robotic-only missions that have been flown and planned to date, and the combined robotic and human missions that will come in the future. Taking advantage of and leveraging those links are central to the idea of a unified Mars exploration plan. One such link is in situ resource utilization (ISRU) as an enabling technology to provide consumables such as fuels, oxygen, sweep and utility gases from the Mars atmosphere.

  17. Asenapine maleate in situ forming biodegradable implant: an approach to enhance bioavailability.

    Avachat, Amelia M; Kapure, Sayali S

    2014-12-30

    Biodegradable injectable in-situ forming implants (ISFI) correspond to an alternative parenteral depot system to microspheres and surgical implants. Objective of present work was to formulate and evaluate long acting implant of asenapine maleate (ASM) using PLGA which would release drug uniformly for 21 days. PLGA 50:50 with different drug: polymer ratios were tried. N-methyl-2-pyrrolidone and dimethyl sulphoxide were used as organic solvents. The influence of various parameters viz. polymer concentration, solvent ratio, viscosity and morphology on formation of implant was investigated. In-vitro dissolution studies indicated that drug: polymer ratio of 1:2 and N-methyl-2-pyrrolidone (0.3ml) gave desired release profile, total cumulative drug released being 97.66% at the end of 21 days. Mathematical models point towards erosion mechanism with zero order kinetics. Ex-vivo studies confirmed the formation of implant in extensor digitorum muscle with desired drug release profile. In-vivo study was performed in Sprague- Dawley rats. Compared to marketed sublingual formulation area under curve of ASM implant was found to increase 2.215 fold. The Cmax was found to be 11ng/ml. Thus long acting ISFI of ASM was successfully formulated showing improved therapeutic results for the treatment of schizophrenia and bipolar disorders which could be a potentialsubstitute to marketed sublingual tablets. PMID:25305379

  18. Enhancement in bioavailability of ketorolac tromethamine via intranasal in situ hydrogel based on poloxamer 407 and carrageenan.

    Li, Chenxi; Li, Chunyan; Liu, Zheshuo; Li, Qiuhong; Yan, Xueying; Liu, Yu; Lu, Weiyue

    2014-10-20

    The objective of this study was to construct a new in situ gel system based on the combination of poloxamer 407 and carrageenan (carrageenan-poloxamer 407 hydrogel, CPH) for intranasal delivery of ketorolac tromethamine. CPH showed potassium ion concentration - dependent erosion characteristics which ensured slow erosion in aqueous environment containing potassium ion at the physiological level. Loading with ketorolac tromethamine influenced erosion, drug release and thermosensitive properties of CPH. CPH containing 15% ketorolac tromethamine showed suitable gelation temperature (near 35°C) and in vitro sustained release profiles. Pharmacokinetic study of intranasal CPH containing 15% ketorolac tromethamine in rats demonstrated enhanced absolute bioavailability (68.8 ± 23.3%) and prolonged mean residence time (8.8 ± 3.5h) in comparison with the intranasal solution group (24.8 ± 13.8%, 3.9 ± 0.6h). Nasal ciliotoxicity evaluation on an in situ toad palate model preliminarily showed the safety of CPH for intranasal use. All results suggested the potential of CPH as a new sustained - release platform for the intranasal delivery of ketorolac tromethamine. PMID:25138250

  19. In situ purity enhancement/surface modification of single-walled carbon nanotubes synthesized by induction thermal plasma

    Shahverdi, Ali; Kim, Keun Su; Alinejad, Yasaman; Soucy, Gervais, E-mail: Gervais.Soucy@Usherbrooke.ca [Universite de Sherbrooke, Department of Chemical and Biotechnological Engineering (Canada)

    2012-02-15

    A simple, cost-effective and energy-efficient approach was developed for in situ purity enhancement and surface modification of single-walled carbon nanotubes (SWCNTs) produced using an induction thermal plasma process. In this process, SWCNT-containing materials are thermally treated with oxygen flow inside a filtration chamber, while they are assembled into the sheets during the synthesis process. Owing to selective thermal oxidation, the amount of amorphous carbon was significantly reduced in the final product resulting in higher purity SWCNT-containing materials. Parametric study indicated that the amorphous carbon content was noticeably diminished in the product at an oxygen volume concentration of 10% in the synthesis system. Raman analysis indicated a decrease in the population of the SWCNTs with diameters smaller than 1.3 nm after in situ exposure to 10 vol.% of oxygen. In addition to the successful reduction of amorphous carbon content, the oxygen-functionalized SWCNTs were also observed in the final product using this process.

  20. In situ protein-DNA interactions at a dioxin-responsive enhancer associated with the cytochrome P1-450 gene.

    Durrin, L K; Whitlock, J P

    1987-01-01

    We used an in situ exonuclease III protection technique (C. Wu, Nature [London] 309:229, 1984) to analyze protein-DNA interactions at a dioxin-responsive enhancer. Our results imply that the 2,3,7,8-tetrachlorodibenzo-p-dioxin-receptor complex interacts with the dioxin-responsive enhancer to activate transcription of the cytochrome P1-450 gene.

  1. Remote plasma enhanced chemical vapor deposition of GaP with in situ generation of phosphine precursors

    Choi, S. W.; Lucovsky, G.; Bachmann, Klaus J.

    1993-01-01

    Thin homoepitaxial films of gallium phosphide (GaP) were grown by remote plasma enhanced chemical vapor deposition utilizing in situ generated phosphine precursors. The GaP forming reaction is kinetically controlled with an activation energy of 0.65 eV. The increase of the growth rate with increasing radio frequency (rf) power between 20 and 100 W is due to the combined effects of increasingly complete excitation and the spatial extension of the glow discharge toward the substrate, however, the saturation of the growth rate at even higher rf power indicates the saturation of the generation rate of phosphine precursors at this condition. Slight interdiffusion of P into Si and Si into GaP is indicated from GaP/Si heterostructures grown under similar conditions as the GaP homojunctions.

  2. One-step in situ synthesis of graphene–TiO{sub 2} nanorod hybrid composites with enhanced photocatalytic activity

    Sun, Mingxuan, E-mail: mingxuansun@sues.edu.cn; Li, Weibin; Sun, Shanfu; He, Jia; Zhang, Qiang; Shi, Yuying

    2015-01-15

    Chemically bonded graphene/TiO{sub 2} nanorod hybrid composites with superior dispersity were synthesized by a one-step in situ hydrothermal method using graphene oxide (GO) and TiO{sub 2} (P25) as the starting materials. The as-prepared samples were characterized by XRD, XPS, TEM, FE-SEM, EDX, Raman, N{sub 2} adsorption, and UV–vis DRS techniques. Enhanced light absorption and a red shift of absorption edge were observed for the composites in the ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS). Their effective photocatalytic activity was evaluated by the photodegradation of methylene blue under visible light irradiation. An enhancement of photocatalytic performance was observed over graphene/TiO{sub 2} nanorod hybrid composite photocatalysts, as 3.7 times larger than that of pristine TiO{sub 2} nanorods. This work demonstrated that the synthesis of TiO{sub 2} nanorods and simultaneous conversion of GO to graphene “without using reducing agents” had shown to be a rapid, direct and clean approach to fabricate chemically bonded graphene/TiO{sub 2} nanorod hybrid composites with enhanced photocatalytic performance.

  3. One-step in situ synthesis of graphene–TiO2 nanorod hybrid composites with enhanced photocatalytic activity

    Chemically bonded graphene/TiO2 nanorod hybrid composites with superior dispersity were synthesized by a one-step in situ hydrothermal method using graphene oxide (GO) and TiO2 (P25) as the starting materials. The as-prepared samples were characterized by XRD, XPS, TEM, FE-SEM, EDX, Raman, N2 adsorption, and UV–vis DRS techniques. Enhanced light absorption and a red shift of absorption edge were observed for the composites in the ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS). Their effective photocatalytic activity was evaluated by the photodegradation of methylene blue under visible light irradiation. An enhancement of photocatalytic performance was observed over graphene/TiO2 nanorod hybrid composite photocatalysts, as 3.7 times larger than that of pristine TiO2 nanorods. This work demonstrated that the synthesis of TiO2 nanorods and simultaneous conversion of GO to graphene “without using reducing agents” had shown to be a rapid, direct and clean approach to fabricate chemically bonded graphene/TiO2 nanorod hybrid composites with enhanced photocatalytic performance

  4. in Situ Formation of a Biocatalytic Alginate Membrane by Enhanced Concentration Polarization

    Marpani, Fauziah; Luo, Jianquan; Mateiu, Ramona Valentina; Meyer, Anne S.; Pinelo, Manuel

    2015-01-01

    immobilized enzyme loadings, which would benefit from the decreased flux in terms of increased enzyme/substrate contact time. The study was performed in a sequential fashion: first, the most suitable types of alginate able to induce a very thin, sustainable gel layer by pressure-driven membrane filtration...... consequence on the type of immobilization promoted in each phase. The results suggested that the strategy proposed could be efficiently used to enhance the enzyme loading on polymer membranes....

  5. Modeling Enhanced In Situ CO2 Mineralization in the Samail Ophiolite Aquifer

    Paukert, A. N.; Matter, J. M.; Kelemen, P. B.; Shock, E.; Streit, E.

    2010-12-01

    The Samail Ophiolite aquifer in the Sultanate of Oman is a site of exceptionally well-developed naturally occurring in situ CO2 mineralization, and serves as a natural analog for an engineered CO2 sequestration process. Natural processes within the aquifer can be described by the following reactions [e.g.1,2]: near the surface, infiltrating rainwater dissolves peridotite, increasing dissolved Mg, Ca, and Si; interaction with soil CO2 and carbonate rocks and dust further increases Ca and dissolved C. At deeper levels, groundwater is cut off from the atmosphere-and hence its CO2 source- but continues to dissolve peridotite, and precipitates serpentine, magnesite, and dolomite. The resulting water has a high Ca-OH concentration, essentially no Mg or dissolved C, and ultrabasic pH. When this alkaline water reaches the shallow subsurface or surface, it mixes with CO2-saturated shallow groundwater or absorbs CO2 directly from the atmosphere. Dissolved C reacts with Ca to precipitate calcite on the surface, lowering the pH to basic. This process forms abundant carbonate minerals, both in the subsurface and in surficial travertine terraces. Water chemistry data can be used to determine the amount of CO2 sequestered. The quantity of CO2 mineralized at the surface as CaCO3 can be calculated from the removal of Ca from alkaline water once it discharges at springs, assuming CaCO3 precipitation is the only surficial Ca sink. Water samples from 22 alkaline spring outlets and 16 surface water bodies were used to calculate the average decrease in Ca and increase in TIC as alkaline spring water discharges and flows along the surface, losing its high pH and converting to basic surface water; the values are 1.26 mmol/L Ca and 3.13 mmol/L TIC, respectively. The increase in TIC can be attributed to absorption of atmospheric CO2. In regions with known flow rates, it is possible to determine the total amount of CO2 mineralized annually. For example, near Masibt where the flow rate of a single spring is 3x107 L/yr, the annual loss of Ca is 3.8x104 moles/yr and the amount of CO2 mineralized as CaCO3 by that spring is 0.85 kg/yr. Over 70 alkaline springs have been mapped throughout the Samail Ophiolite3, and doubtless many more exist. At the surface, Ca availability limits carbonate mineral formation; however, in the subsurface, dissolved CO2 must be the limiting species. TIC decreases from 3.24 mmol/L in shallow groundwater to 0.27 mmol/L in alkaline springs. The loss of 2.96 mmol/L TIC likely occurs by magnesite precipitation, meaning that this amount of CO2 is mineralized in the subsurface. If the availability of dissolved CO2 is the limiting factor in mineralization by the Samail Ophiolite aquifer, it may be possible to engineer the system to increase the rate of sequestration by injecting CO2 into the aquifer. To simulate the outcome of such an engineered system, data from the natural system have been incorporated into a reactive transport model. Results of this simulation will be presented. 1Barnes and ONeil, 1969; 2Bruni et al., 2002; 3Stanger, 1986

  6. Vascularization of the Dermal Support Enhances Wound Re-Epithelialization by In Situ Delivery of Epidermal Keratinocytes

    Lugo, Liana M.; Lei, Pedro

    2011-01-01

    Despite significant advances in management of severe wounds such as burns and chronic ulcers, autologous split-thickness skin grafts are still the gold standard of care. The main problems with this approach include pain and discomfort associated with harvesting autologous tissue, limited availability of donor sites, and the need for multiple surgeries. Although tissue engineering has great potential to provide alternative approaches for tissue regeneration, several problems have hampered progress in translating technological advances to clinical reality. Specifically, engineering of skin substitutes requires long culture times and delayed vascularization after implantation compromises graft survival. To address these issues we developed a novel two-prong strategy for tissue regeneration in vivo: (1) vascularization of acellular dermal scaffolds by infiltration of angiogenic factors; and (2) generation of stratified epidermis by in situ delivery of epidermal keratinocytes onto the prevascularized dermal support. Using athymic mouse as a model system, we found that incorporation of angiogenic factors within acellular human dermis enhanced the density and diameter of infiltrating host blood vessels. Increased vascularization correlated with enhanced proliferation and stratification of the neoepidermis originating from the fibrin-keratinocyte cell suspension. This strategy promoted tissue regeneration in vivo with no need for engineering skin substitutes; therefore, it may be useful for treatment of major wounds when skin donor sites are scarce and rapid wound coverage is required. PMID:20929281

  7. Silver nanoparticles doped agarose disk: highly sensitive surface-enhanced Raman scattering substrate for in situ analysis of ink dyes.

    Raza, Ali; Saha, Basudeb

    2013-12-10

    Raman spectroscopy is a preferred analytical tool for forensic trace analysis due to its non-invasive nature. This technique has been utilized in examination of organic colorants present in fibers and ink, but high fluorescent nature of these compounds is a problem. In the present study, silver-doped agarose gel disk, having property of quenching fluorescence and enhancing Raman signals, is found to be effective as surface-enhanced Raman scattering (SERS) substrates for analysis of rhodamine 6G (Rh 6G) and crystal violet (CV) dyes. As-prepared and well characterized by UV, TEM-EDAX and XRD techniques, the investigated silver-doped agarose gel disk proves to have minimal invasive as confirmed by the ATR-FTIR method and effective for in situ SERS analysis of blue and red ballpoint ink. The disk is stable upon storage and hence can be re-used and re-examined. The present method offers new possibilities in trace forensic analysis with minimal destruction. PMID:24314497

  8. Enhanced photoelectrochemical performance of WO3/Ti photoanode due to in situ formation of a thin interfacial composite layer

    Lee, Won Jae; Shinde, Pravin S.; Go, Geun Ho; Doh, Chil Hoon

    2013-04-01

    Nanostructured WO3 thin films were prepared on titanium sheet substrates using a doctor blade technique. X-ray diffraction, Raman and field emission scanning electron microscopy studies revealed that the synthesized WO3 films are having monoclinic crystal structure, porous, polycrystalline with average grain size of ∼50 nm. The photoelectrochemical responses of WO3 films prepared on treated Ti sheets were recorded in 0.5 M H2SO4 electrolyte under simulated 100 mW/cm2 illumination. WO3 film prepared on polished Ti sheet showed considerable enhancement in photocurrent as compared to WO3 films made on unpolished and pre-oxidized Ti sheets. These results suggest that in situ formation of a thin WOx-TiOy interfacial composite layer and improved adhesion of WO3 nanoparticles owing to increased reactive sites on polished Ti substrate play a significant role in enhancing the photoresponse. Such photoanodes are potential candidates in photoelectrochemical water splitting system for hydrogen generation.

  9. Nano-socketed nickel particles with enhanced coking resistance grown in situ by redox exsolution

    Neagu, Dragos; Oh, Tae-Sik; Miller, David N.; Mnard, Herv; Bukhari, Syed M.; Gamble, Stephen R.; Gorte, Raymond J.; Vohs, John M.; Irvine, John T. S.

    2015-09-01

    Metal particles supported on oxide surfaces are used as catalysts for a wide variety of processes in the chemical and energy conversion industries. For catalytic applications, metal particles are generally formed on an oxide support by physical or chemical deposition, or less commonly by exsolution from it. Although fundamentally different, both methods might be assumed to produce morphologically and functionally similar particles. Here we show that unlike nickel particles deposited on perovskite oxides, exsolved analogues are socketed into the parent perovskite, leading to enhanced stability and a significant decrease in the propensity for hydrocarbon coking, indicative of a stronger metal-oxide interface. In addition, we reveal key surface effects and defect interactions critical for future design of exsolution-based perovskite materials for catalytic and other functionalities. This study provides a new dimension for tailoring particle-substrate interactions in the context of increasing interest for emergent interfacial phenomena.

  10. In Situ Formation of a Biocatalytic Alginate Membrane by Enhanced Concentration Polarization.

    Marpani, Fauziah; Luo, Jianquan; Mateiu, Ramona Valentina; Meyer, Anne S; Pinelo, Manuel

    2015-08-19

    A thin alginate layer induced on the surface of a commercial polysulfone membrane was used as a matrix for noncovalent immobilization of enzymes. Despite the expected decrease of flux across the membrane resulting from the coating, the initial hypothesis was that such a system should allow high immobilized enzyme loadings, which would benefit from the decreased flux in terms of increased enzyme/substrate contact time. The study was performed in a sequential fashion: first, the most suitable types of alginate able to induce a very thin, sustainable gel layer by pressure-driven membrane filtration were selected and evaluated. Then, an efficient method to make the gel layer adhere to the surface of the membrane was developed. Finally, and after confirming that the enzyme loading could remarkably be enhanced by using this method, several strategies to increase the permeate flux were evaluated. Alcohol dehydrogenase (EC 1.1.1.1), able to catalyze the conversion of formaldehyde into methanol, was selected as the model enzyme. An enzyme loading of 71.4% (44.8 ?g/cm(2)) was attained under the optimal immobilization conditions, which resulted in a 40% conversion to methanol as compared to the control setup (without alginate) where only 10.8% (6.9 ?g/cm(2)) enzyme was loaded, with less than 5% conversion. Such conversion increased to 60% when polyethylene glycol (PEG) was added during the construction of the gel layer, as a strategy to increase flux. No enzyme leakage was observed for both cases (with/without PEG addition). Modeling results showed that the dominant fouling mechanism during gel layer induction (involving enzyme entrapment) was cake layer formation in the initial and intermediate phases, while pore blocking was the dominant mechanism in the final phase. Such mechanisms had a direct consequence on the type of immobilization promoted in each phase. The results suggested that the strategy proposed could be efficiently used to enhance the enzyme loading on polymer membranes. PMID:26208080

  11. Development of an In Situ Biosurfactant Production Technology for Enhanced Oil Recovery

    M.J. McInerney; R.M. Knapp; Kathleen Duncan; D.R. Simpson; N. Youssef; N. Ravi; M.J. Folmsbee; T.Fincher; S. Maudgalya; Jim Davis; Sandra Weiland

    2007-09-30

    The long-term economic potential for enhanced oil recovery (EOR) is large with more than 300 billion barrels of oil remaining in domestic reservoirs after conventional technologies reach their economic limit. Actual EOR production in the United States has never been very large, less than 10% of the total U. S. production even though a number of economic incentives have been used to stimulate the development and application of EOR processes. The U.S. DOE Reservoir Data Base contains more than 600 reservoirs with over 12 billion barrels of unrecoverable oil that are potential targets for microbially enhanced oil recovery (MEOR). If MEOR could be successfully applied to reduce the residual oil saturation by 10% in a quarter of these reservoirs, more than 300 million barrels of oil could be added to the U.S. oil reserve. This would stimulate oil production from domestic reservoirs and reduce our nation's dependence on foreign imports. Laboratory studies have shown that detergent-like molecules called biosurfactants, which are produced by microorganisms, are very effective in mobilizing entrapped oil from model test systems. The biosurfactants are effective at very low concentrations. Given the promising laboratory results, it is important to determine the efficacy of using biosurfactants in actual field applications. The goal of this project is to move biosurfactant-mediated oil recovery from laboratory investigations to actual field applications. In order to meet this goal, several important questions must be answered. First, it is critical to know whether biosurfactant-producing microbes are present in oil formations. If they are present, then it will be important to know whether a nutrient regime can be devised to stimulate their growth and activity in the reservoir. If biosurfactant producers are not present, then a suitable strain must be obtained that can be injected into oil reservoirs. We were successful in answering all three questions. The specific objectives of the project were (1) to determine the prevalence of biosurfactant producers in oil reservoirs, and (2) to develop a nutrient regime that would stimulate biosurfactant production in the oil reservoir.

  12. In situ detection and identification of hair dyes using surface-enhanced Raman spectroscopy (SERS).

    Kurouski, Dmitry; Van Duyne, Richard P

    2015-03-01

    Hair is one of the most common types of physical evidence found at a crime scene. Forensic examination may suggest a connection between a suspect and a crime scene or victim, or it may demonstrate an absence of such associations. Therefore, forensic analysis of hair evidence is invaluable to criminal investigations. Current hair forensic examinations are primarily based on a subjective microscopic comparison of hair found at the crime scene with a sample of suspect's hair. Since this is often inconclusive, the development of alternative and more-accurate hair analysis techniques is critical. In this study, we utilized surface-enhanced Raman spectroscopy (SERS) to demonstrate that artificial dyes can be directly detected on hair. This spectroscopic technique is capable of a confirmatory identification of analytes with single molecule resolution, requires minimal sample, and has the advantage of fluorescence quenching. Our study reveals that SERS can (1) identify whether hair was artificially dyed or not, (2) determine if a permanent or semipermanent colorants were used, and (3) distinguish the commercial brands that are utilized to dye hair. Such analysis is rapid, minimally destructive, and can be performed directly at the crime scene. This study provides a novel perspective of forensic investigations of hair evidence. PMID:25635868

  13. In situ stimulation vs. bioaugmentation: Can microbial inoculation of plant roots enhance biodegradation of organic compounds?

    Kingsley, M.T.; Metting, F.B. Jr.; Fredrickson, J.K. [Pacific Northwest Lab., Richland, WA (United States); Seidler, R.J. [Environmental Protection Agency, Corvallis, OR (United States). Environmental Research Lab.

    1993-06-01

    The use of plant roots and their associated rhizosphere bacteria for biocontainment and biorestoration offers several advantages for treating soil-dispersed contaminants and for application to large land areas. Plant roots function as effective delivery systems, since root growth transports bacteria vertically and laterally along the root in the soil column (see [ 1,2]). Movement of microbes along roots and downward in the soil column can be enhanced via irrigation [1-4]. For example, Ciafardini et al. [3] increased the nodulation and the final yield of soybeans during pod filling by including Bradyrhizobium japonicum in the irrigation water. Using rhizosphere microorganisms is advantageous for biodegradation of compounds that are degraded mainly by cometabolic processes, e.g., trichloroethylene (TCE). The energy source for bacterial growth and metabolism is supplied by the plant in the form of root exudates and other sloughed organic material. Plants are inexpensive, and by careful choice of species that possess either tap or fibrous root growth patterns, they can be used to influence mass transport of soil contaminants to the root surface via the transpiration stream [5]. Cropping of plants to remove heavy metals from contaminated soils has been proposed as a viable, low-cost, low-input treatment option [6]. The interest in use of plants as a remediation strategy has even reached the popular press [7], where the use of ragweed for the reclamation of sites contaminated with tetraethyl lead and other heavy metals was discussed.

  14. In Situ Integration of Anisotropic SnO₂ Heterostructures inside Three-Dimensional Graphene Aerogel for Enhanced Lithium Storage.

    Yao, Xin; Guo, Guilue; Ma, Xing; Zhao, Yang; Ang, Chung Yen; Luo, Zhong; Nguyen, Kim Truc; Li, Pei-Zhou; Yan, Qingyu; Zhao, Yanli

    2015-12-01

    Three-dimensional (3D) graphene aerogel (GA) has emerged as an outstanding support for metal oxides to enhance the overall energy-storage performance of the resulting hybrid materials. In the current stage of the studies, metals/metal oxides inside GA are in uncrafted geometries. Introducing structure-controlled metal oxides into GA may further push electrochemical properties of metal oxide-GA hybrids. Using rutile SnO2 as an example, we demonstrated here a facile hydrothermal strategy combined with a preconditioning technique named vacuum-assisted impregnation for in situ construction of controlled anisotropic SnO2 heterostructures inside GA. The obtained hybrid material was fully characterized in detail, and its formation mechanism was investigated by monitoring the phase-transformation process. Rational integration of the two advanced structures, anisotropic SnO2 and 3D GA, synergistically led to enhanced lithium-storage properties (1176 mAh/g for the first cycle and 872 mAh/g for the 50th cycle at 100 mA/g) as compared with its two counterparts, namely, rough nanoparticles@3D GA and anisotropic SnO2@2D graphene sheets (618 and 751 mAh/g for the 50th cycle at 100 mA/g, respectively). It was also well-demonstrated that this hybrid material was capable of delivering high specific capacity at rapid charge/discharge cycles (1044 mAh/g at 100 mA/g, 847 mAh/g at 200 mA/g, 698 mAh/g at 500 mA/g, and 584 mAh/g at 1000 mA/g). The in situ integration strategy along with vacuum-assisted impregnation technique presented here shows great potential as a versatile tool for accessing a variety of sophisticated smart structures in the form of anisotropic metals/metal oxides within 3D GA toward useful applications. PMID:26554275

  15. FIELD TEST OF CYCLODEXTRIN FOR ENHANCED IN-SITU FLUSHING OF MULTIPLE-COMPONENT IMMISCIBLE ORGANIC LIQUID CONTAMINATION: PROJECT OVERVIEW AND INITIAL RESULTS

    The purpose of this paper is to present an overview and the initial results of a pilot-scale experiment designated to test the use of cyclodextrin for enhanced in-situ flushing of an aquifer contaminated by immiscible liquid. This is the first field test of this technology, terme...

  16. Chemical Looping Gasification for Hydrogen Enhanced Syngas Production with In-Situ CO2 Capture

    Kathe, Mandar [Ohio State University, Columbus, OH (United States); Xu, Dikai [Ohio State University, Columbus, OH (United States); Hsieh, Tien-Lin [Ohio State University, Columbus, OH (United States); Simpson, James [Ohio State University, Columbus, OH (United States); Statnick, Robert [Ohio State University, Columbus, OH (United States); Tong, Andrew [Ohio State University, Columbus, OH (United States); Fan, Liang-Shih [Ohio State University, Columbus, OH (United States)

    2014-12-31

    This document is the final report for the project titled “Chemical Looping Gasification for Hydrogen Enhanced Syngas Production with In-Situ CO2 Capture” under award number FE0012136 for the performance period 10/01/2013 to 12/31/2014.This project investigates the novel Ohio State chemical looping gasification technology for high efficiency, cost efficiency coal gasification for IGCC and methanol production application. The project developed an optimized oxygen carrier composition, demonstrated the feasibility of the concept and completed cold-flow model studies. WorleyParsons completed a techno-economic analysis which showed that for a coal only feed with carbon capture, the OSU CLG technology reduced the methanol required selling price by 21%, lowered the capital costs by 28%, increased coal consumption efficiency by 14%. Further, using the Ohio State Chemical Looping Gasification technology resulted in a methanol required selling price which was lower than the reference non-capture case.

  17. In situ plasma fabrication of ceramic-like structure on polymeric implant with enhanced surface hardness, cytocompatibility and antibacterial capability.

    Liu, Jun; Zhang, Wei; Shi, Haigang; Yang, Kun; Wang, Gexia; Wang, Pingli; Ji, Junhui; Chu, Paul K

    2016-05-01

    Polymeric materials are commonly found in orthopedic implants due to their unique mechanical properties and biocompatibility but the poor surface hardness and bacterial infection hamper many biomedical applications. In this study, a ceramic-like surface structure doped with silver is produced by successive plasma implantation of silicon (Si) and silver (Ag) into the polyamine 66 (PA66) substrate. Not only the surface hardness and elastic modulus are greatly enhanced due to the partial surface carbonization and the ceramic-like structure produced by the reaction between energetic Si and the carbon chain of PA66, but also the antibacterial activity is improved because of the combined effects rendered by Ag and SiC structure. Furthermore, the modified materials which exhibit good cytocompatibility upregulate bone-related genes and proteins expressions of the contacted bone mesenchymal stem cells (BMSCs). For the first time, it explores out that BMSCs osteogenesis on the antibacterial ceramic-like structure is mediated via the iNOS and nNOS signal pathways. The results reveal that in situ plasma fabrication of an antibacterial ceramic-like structure can endow PA66 with excellent surface hardness, cytocompatibility, as well as antibacterial capability. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1102-1112, 2016. PMID:26825052

  18. In Situ Analysis of a Silver Nanoparticle-Precipitating Shewanella Biofilm by Surface Enhanced Confocal Raman Microscopy.

    Schkolnik, Gal; Schmidt, Matthias; Mazza, Marco G; Harnisch, Falk; Musat, Niculina

    2015-01-01

    Shewanella oneidensis MR-1 is an electroactive bacterium, capable of reducing extracellular insoluble electron acceptors, making it important for both nutrient cycling in nature and microbial electrochemical technologies, such as microbial fuel cells and microbial electrosynthesis. When allowed to anaerobically colonize an Ag/AgCl solid interface, S. oneidensis has precipitated silver nanoparticles (AgNp), thus providing the means for a surface enhanced confocal Raman microscopy (SECRaM) investigation of its biofilm. The result is the in-situ chemical mapping of the biofilm as it developed over time, where the distribution of cytochromes, reduced and oxidized flavins, polysaccharides and phosphate in the undisturbed biofilm is monitored. Utilizing AgNp bio-produced by the bacteria colonizing the Ag/AgCl interface, we could perform SECRaM while avoiding the use of a patterned or roughened support or the introduction of noble metal salts and reducing agents. This new method will allow a spatially and temporally resolved chemical investigation not only of Shewanella biofilms at an insoluble electron acceptor, but also of other noble metal nanoparticle-precipitating bacteria in laboratory cultures or in complex microbial communities in their natural habitats. PMID:26709923

  19. Positive enhancement integral values in dynamic contrast enhanced magnetic resonance imaging of breast carcinoma: Ductal carcinoma in situ vs. invasive ductal carcinoma

    Nadrljanski, Mirjan, E-mail: dr.m.nadrljanski@gmail.com [Clinic for Radiology and Radiation Oncology, Institute of Oncology and Radiology of Serbia, Pasterova 14, 11000 Belgrade (Serbia); Maksimović, Ružica [Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Pasterova 2, 11000 Belgrade (Serbia); Faculty of Medicine, University of Belgrade, Dr Subotića 8, 11000 Belgrade (Serbia); Plešinac-Karapandžić, Vesna; Nikitović, Marina [Clinic for Radiology and Radiation Oncology, Institute of Oncology and Radiology of Serbia, Pasterova 14, 11000 Belgrade (Serbia); Faculty of Medicine, University of Belgrade, Dr Subotića 8, 11000 Belgrade (Serbia); Marković-Vasiljković, Biljana [Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Pasterova 2, 11000 Belgrade (Serbia); Faculty of Medicine, University of Belgrade, Dr Subotića 8, 11000 Belgrade (Serbia); Milošević, Zorica [Clinic for Radiology and Radiation Oncology, Institute of Oncology and Radiology of Serbia, Pasterova 14, 11000 Belgrade (Serbia); Faculty of Medicine, University of Belgrade, Dr Subotića 8, 11000 Belgrade (Serbia)

    2014-08-15

    Objectives: The aim of this study was to contribute to the standardization of the numeric positive enhancement integral (PEI) values in breast parenchyma, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) and to evaluate the significance of the difference in PEI values between IDC and parenchyma, DCIS and parenchyma and IDC and DCIS. Materials and Methods: In the prospective trial, we analyzed the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of 60 consecutive patients with histologically confirmed unilateral DCIS (n = 30) and IDC (n = 30) and defined the PEI values (range; mean ± SD) for the lesions and the breast parenchyma. Tumor-to-non-tumor (T/NT) ratios were calculated for DCIS and IDC and compared. PEI color maps (PEICM) were created. The differences in PEI values between IDC and parenchyma and between DCIS and parenchyma were tested according to t-test. Analysis of variance (ANOVA) was used to test the differences between the mean PEI values of parenchyma, DCIS and IDC. Results: IDC showed highly statistically different PEI numeric values compared to breast parenchyma (748.7 ± 32.2 vs. 74.6 ± 17.0; p < 0.0001). The same applied to the differences in the group of patients with DCIS (428.0 ± 25.0 vs. 66.0 ± 10.6; p < 0.0001). The difference between IDC, DCIS and parenchyma were also considered highly statistically significant (p < 0.0001) and so were the T/NT ratios for IDC and DCIS (10.1 ± 2.4 vs. 6.6 ± 1.4; p < 0.0001). Conclusions: PEI numeric values may contribute to differentiation between invasive and in situ breast carcinoma.

  20. Positive enhancement integral values in dynamic contrast enhanced magnetic resonance imaging of breast carcinoma: Ductal carcinoma in situ vs. invasive ductal carcinoma

    Objectives: The aim of this study was to contribute to the standardization of the numeric positive enhancement integral (PEI) values in breast parenchyma, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) and to evaluate the significance of the difference in PEI values between IDC and parenchyma, DCIS and parenchyma and IDC and DCIS. Materials and Methods: In the prospective trial, we analyzed the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of 60 consecutive patients with histologically confirmed unilateral DCIS (n = 30) and IDC (n = 30) and defined the PEI values (range; mean ± SD) for the lesions and the breast parenchyma. Tumor-to-non-tumor (T/NT) ratios were calculated for DCIS and IDC and compared. PEI color maps (PEICM) were created. The differences in PEI values between IDC and parenchyma and between DCIS and parenchyma were tested according to t-test. Analysis of variance (ANOVA) was used to test the differences between the mean PEI values of parenchyma, DCIS and IDC. Results: IDC showed highly statistically different PEI numeric values compared to breast parenchyma (748.7 ± 32.2 vs. 74.6 ± 17.0; p < 0.0001). The same applied to the differences in the group of patients with DCIS (428.0 ± 25.0 vs. 66.0 ± 10.6; p < 0.0001). The difference between IDC, DCIS and parenchyma were also considered highly statistically significant (p < 0.0001) and so were the T/NT ratios for IDC and DCIS (10.1 ± 2.4 vs. 6.6 ± 1.4; p < 0.0001). Conclusions: PEI numeric values may contribute to differentiation between invasive and in situ breast carcinoma

  1. The health-enhancing efficacy of Zumba® fitness: An 8-week randomised controlled study.

    Domene, Pablo A; Moir, Hannah J; Pummell, Elizabeth; Knox, Allan; Easton, Chris

    2016-08-01

    The purpose of this study was to gain a holistic understanding of the efficacy of Zumba® fitness in a community-recruited cohort of overweight and physically inactive women by evaluating (i) its physiological effects on cardiovascular risk factors and inflammatory biomarkers and (ii) its mental health-enhancing effects on factors of health-related quality of life (HRQoL). Participants were randomly assigned to either engagement in one to two 1 h classes of Zumba® fitness weekly (intervention group; n = 10) or maintenance of habitual activity (control group; n = 10). Laboratory assessments were conducted pre- (week 0) and post-intervention (week 8) with anthropometric, physiological, inflammatory and HRQoL data collected. In the intervention group, maximal oxygen uptake significantly increased (P < 0.05; partial η(2) = 0.56) by 3.1 mL · kg(-1) · min(-1), per cent body fat significantly decreased (P < 0.05; partial η(2) = 0.42) by -1.2%, and interleukin-6 and white blood cell (WBC) count both significantly decreased (P < 0.01) by -0.4 pg · mL(-1) (partial η(2) = 0.96) and -2.1 × 10(9) cells · L(-1) (partial η(2) = 0.87), respectively. Large magnitude enhancements were observed in the HRQoL factors of physical functioning, general health, energy/fatigue and emotional well-being. When interpreted in a community-based physical activity and psychosocial health promotion context, our data suggest that Zumba® fitness is indeed an efficacious health-enhancing activity for adults. PMID:26571136

  2. Direct observation of hydrogen-enhanced plasticity in super duplex stainless steel by means of in situ electrochemical methods

    In situ electrochemical hydrogen charging in combination with atomic force microscopy and optical microscopy has been used to study the effect of hydrogen on the austenite phase in super duplex stainless steel. Observations showed that hydrogen charging results in an irreversible deformation of austenite. High residual tensile stresses form in austenite during quench annealing. These stresses, in combination with the activation of dislocation sources by hydrogen, result in formation of slip lines on the austenite surface during in situ hydrogen charging.

  3. In situ formation of nanocrystals from a self-microemulsifying drug delivery system to enhance oral bioavailability of fenofibrate

    Lin YM

    2011-10-01

    Full Text Available You-Meei Lin1, Jui-Yu Wu2, Ying-Chen Chen3, Yu-Der Su3, Wen-Tin Ke3, Hsiu-O Ho31Department of Pharmacy, Shuang Ho Hospital, 2Department of Biochemistry, School of Medicine, 3School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan, ROCObjectives: In situ formation of nanocrystals and dissolution profiles of fenofibrate (FFB from a self-microemulsifying drug delivery system (SMEDDS were characterized.Methods: SMEDDS formulated with Myritol® and surfactant mixture (Smix of D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS and either Tween® 20 (A, C, E, G, M, S, N, T, O or Tween® 80 (B, D, F, H, P, U, Q, V, R at various oil/Smix ratios (Group I: A and B of 0.42, C and D of 0.25, E and F of 0.11; Group II: G and H of 1.38, M and P of 1.11, S and U of 0.9, N and Q of 0.73, T and V of 0.58, and O and R of 0.46 and water contents (1: 9.5%, 2: 5.0%, 3: 0.0%, G-V: 4.5%. Their dissolutions were conducted at different rotation speeds. Two optimal SMEDDSs containing Tween 80(B2 or a higher oil/Smix ratio(Q and B2(solution were selected for pharmacokinetic study.Results: FFB particles formed within the nanosize range from Group I gradually increased with time but decreased with increasing stirring rates. However, the mean size of FFB formed by B series was as low as 200 nm, which was smaller than that of A series at three stirring rates. The release rate from both groups obviously increased with increasing stirring rate. However, incomplete release was observed for S and N in Tween 20 series, whereas a faster release rate and complete release were observed for Tween 80 series with an insignificant difference among them. Results of pharmacokinetic study demonstrated that the highest-ranked area under the curve and Cmax values were for Q(SMEDDS and B2(solution, respectively. The relative bioavailability of Q(SMEDDS with respect to Tricor® was enhanced by about 1.14-1.22-fold.Conclusion: SMEDDS, consisting of Myritol 318 and TPGS combined with Tween 80 at 4:1, was able to enhance the oral bioavailability of FFB.Keywords: SMEDDS, fenofibrate, microemulsion, dissolution, TPGS

  4. In situ vertical profiles of aerosol extinction, mass, and composition over the southeast United States during SENEX and SEAC4RS: observations of a modest aerosol enhancement aloft

    Wagner, N. L.; Brock, C. A.; Angevine, W. M.; A. Beyersdorf; P. Campuzano-Jost; Day, D. A.; Gouw, J.A. De; Diskin, G. S.; Gordon, T. D.; Graus, M. G.; Huey, G.; Jimenez, J.L.; Lack, D. A.; Liao, J.; X. LIU

    2015-01-01

    Vertical profiles of submicron aerosol over the southeastern United States (SEUS) during the summertime from in situ aircraft-based measurements were used to construct aggregate profiles of chemical, microphysical, and optical properties. Shallow cumulus convection was observed during many profiles. These conditions enhance vertical transport of trace gases and aerosol and create a cloudy transition layer on top of the sub-cloud mixed layer. The trace gas and ...

  5. Monitoring of the growth of microcrystalline silicon by plasma-enhanced chemical vapor deposition using in-situ Raman spectroscopy

    Muthmann, S.; Koehler, F.; Meier, M.; Huelsbeck, M.; Carius, R.; Gordijn, A. [IEK5-Photovoltaik, Forschungszentrum Juelich, 52425 Juelich (Germany)

    2011-04-15

    Raman spectra of microcrystalline silicon layers have been recorded in-situ during growth. The spectra have been collected under realistic conditions for solar cell deposition. To enable these measurements an electrode with an optical feed through has been developed. By using a metallic grid to shield the feed through it is possible to achieve homogeneous deposition of {mu}c-Si:H at a sufficient optical transmission. In-situ Raman measurements were carried out during the deposition of a layer with an intentionally introduced gradient in crystallinity that was seen in-situ as well in reference measurements performed on the same layer ex-situ. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Enhanced hydrogen embrittlement of Pd-coated niobium metal membrane detected by in situ small punch test under hydrogen permeation

    The hydrogen embrittlement of pure niobium metal membrane was investigated under a hydrogen atmosphere by using a newly developed in situ small punch apparatus. The boundary for the ductile-to-brittle transition of the palladium-coated pure niobium was determined from a series of the in situ small punch tests. The measured boundary was found to be shifted greatly to the lower hydrogen content region as compared to that of palladium non-coated niobium membrane. The present result will provide us a clue to the design of niobium-based permeable membrane against the hydrogen embrittlement

  7. Differentiation between ductal carcinoma in situ and mastopathy using dynamic contrast-enhanced magnetic resonance imaging and a model of contrast enhancement

    The purpose of this study was to retrospectively evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to differentiate between ductal carcinoma in situ (DCIS) and mastopathy by analyzing their time-intensity curves (TICs) using the two-compartment pharmacokinetic model with an assumption of instantaneous injection of contrast medium (TCPM). After the pre-contrast MRI was performed using a 1.5 T MRI system, DCE-MRI was performed four times after the intravenous administration of contrast medium. We set the volumes of interest (VOIs) on the tumor and normal mammary gland, and obtained the TICs in these VOIs. We calculated the following parameters by fitting these TICs to the equation derived from TCPM; the initial slope of the TIC (Slopeini), the area under the TIC (AUC), the time to peak enhancement (TTP) and the peak enhancement (PeakE). We calculated these parameters in both the lesion and normal mammary gland and the ratios of the parameters in the lesion to those in the normal gland (rSlopeini, rAUC, rTTP and rPeakE). There were significant differences in Slopeini (P = 0.009), PeakE (P = 0.019), rSlopeini (P = 0.010), and rTTP (P = 0.005) between DCIS and mastopathy. The areas under the receiver operating characteristic curve for Slopeini, PeakE, rSlopeini, and rTTP were 0.67 ± 0.06 (P = 0.009), 0.65 ± 0.06 (P = 0.019), 0.67 ± 0.06 (P = 0.01), and 0.68 ± 0.06 (P = 0.005), respectively. In conclusion, our results suggest that analysis of TICs obtained by DCE-MRI using TCPM appears to be useful for differentiating between DCIS and mastopathy.

  8. In situ synthesis of Bi2S3 sensitized WO3 nanoplate arrays with less interfacial defects and enhanced photoelectrochemical performance.

    Liu, Canjun; Yang, Yahui; Li, Wenzhang; Li, Jie; Li, Yaomin; Chen, Qiyuan

    2016-01-01

    In this study, Bi2S3 sensitive layer has been grown on the surface of WO3 nanoplate arrays via an in situ approach. The characterization of samples were carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and ultraviolet-visible absorption spectroscopy (UV-vis). The results show that the Bi2S3 layer is uniformly formed on the surface of WO3 nanoplates and less interfacial defects were observed in the interface between the Bi2S3 and WO3. More importantly, the Bi2S3/WO3 films as photoanodes for photoelectrochemical (PEC) cells display the enhanced PEC performance compared with the Bi2S3/WO3 films prepared by a sequential ionic layer adsorption reaction (SILAR) method. In order to understand the reason for the enhanced PEC properties, the electron transport properties of the photoelectrodes were studied by using the transient photocurrent spectroscopy and intensity modulated photocurrent spectroscopy (IMPS). The Bi2S3/WO3 films prepared via an in situ approach have a greater transient time constant and higher electron transit rate. This is most likely due to less interfacial defects for the Bi2S3/WO3 films prepared via an in situ approach, resulting in a lower resistance and faster carrier transport in the interface between WO3 and Bi2S3. PMID:26988275

  9. Encapsulation of LiFePO4 by in-situ graphitized carbon cage towards enhanced low temperature performance as cathode materials for lithium ion batteries

    The severe capacity decay of LiFePO4 at low temperatures (≤0 °C) limits its wide applications as cathode materials for energy storage batteries. Creating comprehensive carbon network between particles with improved electronic conductivity is a well known solution to this problem. Here, a novel structured LiFePO4/C composite was prepared by a facile solid state route, in which nanosized LiFePO4 spheres were encapsulated by in-situ graphitized carbon cages. With the enhancement in electronic conductivity (2.15e−1 S cm−1), the composite presented excellent rate performance at room temperature and remarkable capacity retention at −40 °C, with charge transfer resistance much lower than commercial LiFePO4. - Graphical abstract: A novel structured LiFePO4/C composite was prepared by a facile solid state route, in which nanosized LiFePO4 spheres were encapsulated by in-situ graphitized carbon cages. - Highlights: • Several nano-sized LiFePO4 particles are encapsulated in carbon cage. • Carbon is in-situ graphitized with enhanced electronic conductivity. • The as prepared LiFePO4 exhibits notable capacity retention at −40 °C. • Rct is lowered by a factor of ∼10 compared with commercial LiFePO4

  10. Comparative studies of atomic layer deposition and plasma-enhanced atomic layer deposition Ta2O5 and the effects on electrical properties of in situ nitridation

    Ta2O5 and TaOxNy thin films were deposited by atomic layer deposition (ALD) from Ta(NMe2)5 (PDMAT) with water, oxygen plasma, and nitrogen added oxygen plasma. The film properties were comparatively investigated focusing on the electrical properties from metal oxide semiconductor capacitor structure with 10 nm Ta2O5 or TaOxNy. The results show that plasma-enhanced ALD (PE-ALD) Ta2O5 film has better electrical properties including lower interface state density and leakage current than thermal ALD. Moreover, PE-ALD TaOxNy shows the best properties, indicating the beneficial effects of in situ nitridation. Especially, time dependent dielectric breakdown was significantly improved up to 4000 times of thermal ALD Ta2O5. These results show that, intentional in situ nitrogen incorporation with good electrical properties was successfully achieved by PE-ALD using nitrogen-oxygen mixture. (author)

  11. Long-term population dynamics and in situ physiology in activated sludge systems with enhanced biological phosphorus removal operated with and without nitrogen removal

    Lee, N.; Nielsen, P.H.; Aspegren, H.; Henze, Mogens; Schleifer, K.-H.; Jansen, J.l.C.

    2003-01-01

    removal (EBPR). The two systems received the same influent wastewater, but were differently operated (with and without nitrogen removal, respectively). Both systems showed a significant P removal that increased when different substrates (phosphorus (P), acetate and glucose, respectively) were added to the......Quantitative fluorescence in situ hybridization (FISH) and the combination of FISH with microautoradiography (MAR) were used in order to study the long-term population dynamics (2.5 years) and the in situ physiology in two parallel activated sludge pilot systems with enhanced biological phosphorus....... However, we observed a lower correlation (0.9). The Actinobacteria were the only additional group of bacteria which showed a similar degree of correlation to the P content in activated sludge as the Rhodocyclus-related bacteria - but only for the system without nitrogen removal. Significant amounts (less...

  12. In-situ treatment of a mixed hydrocarbon plume through enhanced bio-remediation and a PRB system

    Groundwater is frequently polluted with mixtures of contaminants that are amenable to different types of remediation. One example is the combination of petroleum hydrocarbons (BTEX) and chlorinated solvents (PCE, TCE, DCE, VC), as it occurs in the groundwater beneath the industrial site that is the objective of the present case study. The site is located in Italy near a main river (Arno), which is supposed to be the final recipient of the contamination and where a possible exposure might take place. The aim of the treatment is the plume containment within the site boundaries in order to avoid further migration of the contaminants towards the river. The design of the remediation system was based on an extensive site characterization that included - but was not limited to - the following information: geological and geochemical, microbiological and hydrological data, together with analytical data (i.e. contaminant concentrations). Pilot tests were also implemented in order to collect the necessary parameters for the full-scale treatment design and calibration. The monitoring of the site conditions was carried out throughout a period of several months, both with periodical measurements and sampling and with fixed monitoring probes, in order to record the aquifer changes (levels, concentrations, etc.) related both to seasonal variations and to the pilot tests. The groundwater is located in a highly heterogeneous aquifer, with a saturated thickness of 1.5 m and an average hydraulic conductivity of 2.5 x 10-5 m/s. The seepage velocity is extremely low, with a mean value around 1.3 mm/d. This results in a long residence time and limited volumes per time unit to be treated. The site was contaminated by a mixed plume of more than 15 different contaminants, ranging from BTEX, to MTBE, to PAH, to chlorinated solvents. The concentration peaks were in the order of 1-100 mg/l for each contaminant. Petroleum hydrocarbons are quickly degradable through oxidative mechanisms (especially aerobic biodegradation), whereas fully-chlorinated compounds are only biodegradable via reductive pathways. Therefore, a mixed plume of both types of contaminants requires a combined approach with the application of different treatment technologies. The remediation strategy elaborated combines an enhanced bio-remediation of the hot spots with a permeable reactive barrier (PRB) in a funnel and gate configuration for the down-gradient plume containment. Pilot tests were carried out in order to assess the efficiency and feasibility of such technologies in the site of interest. The enhanced bio-remediation is going to be carried out by means of injections of hydrogen release compounds (HRC) and oxygen release compounds (ORC) for the biodegradation of chlorinated solvents and petroleum hydrocarbons respectively. A pilot test was conducted to determine the degradation rates of the different contaminants. The pilot test was monitored with a periodic sampling and analysis of the groundwater and with a continuous monitoring of the physical-chemical parameters (temperature, pH, conductivity, redox potential and dissolved oxygen) in the monitoring wells placed immediately down-gradient of the injection points. The tests showed the possibility to use the enhanced bio-remediation with the double aim to reduce the hot spot concentrations, in order to lower the contaminant load on the PRB, and to control the lateral spreading of the plume in the side regions. Permeable reactive barriers are passive groundwater treatment systems that are able to decontaminate groundwater as it flows through a permeable treatment medium under natural gradients. The main advantage of this technology over ex-situ and other in-situ groundwater remediation approaches is the reduced operation- and maintenance costs. For the permeable reactive barrier, a funnel and gate configuration was selected. This system uses low permeability materials (funnel) to direct groundwater towards a permeable treatment zone (gate). To ensure that flow beneath the system does not occur, funnel and gate systems must be keyed into an underlying low permeable zone (marl, in our case). A geotechnical test was conducted in order to choose the most suitable material for the impermeable portion of the barrier (the funnel). For the selection of the reactive media (gate), different materials were tested. The efficiency of zero-valent iron (ZVI) was investigated through laboratory tests for the reductive dechlorination of aliphatic halo-carbons. Granular activated carbon (GAC) was also laboratory tested for the removal of a wide range of contaminants from the groundwater. Primary objectives of the tests were the assessment of the degradation or removal rates, the minimum thickness of the gate required for a sufficient removal of the contaminants (down-gradient concentrations below the law limits) and the costs for a full-scale treatment. In the end, a combined gate with ZVI followed by GAC was selected for the full-scale PRB implemented at the site. The article describes the tests that have been carried out and the results achieved, together with the selected treatment train, its design and dimensioning

  13. X-231A demonstration of in-situ remediation of DNAPL compounds in low permeability media by soil fracturing with thermally enhanced mass recovery or reactive barrier destruction

    The overall goal of the program of activities is to demonstrate robust and cost-effective technologies for in situ remediation of DNAPL compounds in low permeability media (LPM), including adaptations and enhancements of conventional technologies to achieve improved performance for DNAPLs in LPM. The technologies sought should be potential for application at simple, small sites (e.g., gasoline underground storage tanks) as well as at complex, larger sites (e.g., DOE land treatment units). The technologies involved in the X-231A demonstration at Portsmouth Gaseous Diffusion Plant (PORTS) utilized subsurface manipulation of the LPM through soil fracturing with thermally enhanced mass recovery or horizontal barrier in place destruction. To enable field evaluation of these approaches, a set of four test cells was established at the X-231A land treatment unit at the DOE PORTS plant in August 1996 and a series of demonstration field activities occurred through December 1997. The principal objectives of the PORTS X-231A demonstration were to: determine and compare the operational features of hydraulic fractures as an enabling technology for steam and hot air enhanced soil vapor extraction and mass recovery, in situ interception and reductive destruction by zero valent iron, and in situ interception and oxidative destruction by potassium permanganate; determine the interaction of the delivered agents with the LPM matrix adjacent to the fracture and within the fractured zone and assess the beneficial modifications to the transport and/or reaction properties of the LPM deposit; and determine the remediation efficiency achieved by each of the technology strategies

  14. X-231A demonstration of in-situ remediation of DNAPL compounds in low permeability media by soil fracturing with thermally enhanced mass recovery or reactive barrier destruction

    Siegrist, R.L. [Oak Ridge National Lab., TN (United States)]|[Colorado School of Mines, Golden, CO (United States). Environmental Science and Engineering Div.; Lowe, K.S. [Oak Ridge National Lab., Grand Junction, CO (United States). Life Sciences Div.; Murdoch, L.D. [FRx, Inc., Cincinnati, OH (United States)]|[Clemson Univ., SC (United States); Slack, W.W. [FRx, Inc., Cincinnati, OH (United States); Houk, T.C. [Lockheed Martin Energy Systems, Piketon, OH (United States)

    1998-03-01

    The overall goal of the program of activities is to demonstrate robust and cost-effective technologies for in situ remediation of DNAPL compounds in low permeability media (LPM), including adaptations and enhancements of conventional technologies to achieve improved performance for DNAPLs in LPM. The technologies sought should be potential for application at simple, small sites (e.g., gasoline underground storage tanks) as well as at complex, larger sites (e.g., DOE land treatment units). The technologies involved in the X-231A demonstration at Portsmouth Gaseous Diffusion Plant (PORTS) utilized subsurface manipulation of the LPM through soil fracturing with thermally enhanced mass recovery or horizontal barrier in place destruction. To enable field evaluation of these approaches, a set of four test cells was established at the X-231A land treatment unit at the DOE PORTS plant in August 1996 and a series of demonstration field activities occurred through December 1997. The principal objectives of the PORTS X-231A demonstration were to: determine and compare the operational features of hydraulic fractures as an enabling technology for steam and hot air enhanced soil vapor extraction and mass recovery, in situ interception and reductive destruction by zero valent iron, and in situ interception and oxidative destruction by potassium permanganate; determine the interaction of the delivered agents with the LPM matrix adjacent to the fracture and within the fractured zone and assess the beneficial modifications to the transport and/or reaction properties of the LPM deposit; and determine the remediation efficiency achieved by each of the technology strategies.

  15. In situ plasma enhanced atomic layer deposition half cycle study of Al2O3 on AlGaN/GaN high electron mobility transistors

    A half cycle study of plasma enhanced atomic layer deposited (PEALD) Al2O3 on AlGaN is investigated using in situ X-ray photoelectron spectroscopy, low energy ion scattering, and ex situ electrical characterizations. A faster nucleation or growth is detected from PEALD relative to purely thermal ALD using an H2O precursor. The remote O2 plasma oxidizes the AlGaN surface slightly at the initial stage, which passivates the surface and reduces the OFF-state leakage. This work demonstrates that PEALD is a useful strategy for Al2O3 growth on AlGaN/GaN devices

  16. In situ plasma enhanced atomic layer deposition half cycle study of Al2O3 on AlGaN/GaN high electron mobility transistors

    Qin, Xiaoye; Wallace, Robert M.

    2015-08-01

    A half cycle study of plasma enhanced atomic layer deposited (PEALD) Al2O3 on AlGaN is investigated using in situ X-ray photoelectron spectroscopy, low energy ion scattering, and ex situ electrical characterizations. A faster nucleation or growth is detected from PEALD relative to purely thermal ALD using an H2O precursor. The remote O2 plasma oxidizes the AlGaN surface slightly at the initial stage, which passivates the surface and reduces the OFF-state leakage. This work demonstrates that PEALD is a useful strategy for Al2O3 growth on AlGaN/GaN devices.

  17. Microwave-assisted in situ synthesis of reduced graphene oxide-BiVO4 composite photocatalysts and their enhanced photocatalytic performance for the degradation of ciprofloxacin

    Highlights: ► Microwave-assisted in situ growth of RGO-BiVO4 composite was proposed. ► A relatively small particle size with organic-additives free. ► Graphene was formed during the microwave-heating by oxygen capture. ► GB-2 sample exhibits the highest CIP degradation ratio (3 times over pure BiVO4). ► The enhancements of activities result from the effective charge separation. -- Abstract: To improve the photodegradation efficiency for ciprofloxacin (CIP), a new-type microwave-assisted in situ growth method is developed for the preparation of reduced graphene oxide (RGO) -BiVO4 composite photocatalysts. The as-produced RGO-BiVO4 composite photocatalysts show extremely high enhancement of CIP degradation ratio over the pure BiVO4 photocatalyst under visible light. Specially, the 2 wt% RGO-BiVO4 composite photocatalyst exhibits the highest CIP degradation ratio (68.2%) in 60 min, which is over 3 times than that (22.7%) of the pure BiVO4 particles. The enhancement of photocatalytic activities of RGO-BiVO4 photocatalysts can be attributed to the effective separation of electron–hole pairs rather than the improvement of light absorption

  18. Double-wall TiO2 nanotube arrays: enhanced photocatalytic activity and in situ TEM observations at high temperature.

    Xue, Chaorui; Narushima, Takashi; Ishida, Yohei; Tokunaga, Tomoharu; Yonezawa, Tetsu

    2014-11-26

    By decreasing the water content in an NH4F and glycerol-water electrolyte, the transition from single-wall to double-wall TiO2 nanotube arrays was successfully achieved using an anodization method. The double-wall TiO2 nanotube structures exhibited better photocatalytic activity than the typical single-wall structures. After modification with platinum nanoparticles, the photocatalytic activity of both the single- and double-wall TiO2 nanotubes was improved further. In situ observations at the annealing temperature of the TiO2 nanotubes were performed using a transmission electron microscopy (TEM) system. A slower structural failure of the nanotubes was obtained with the introduction of oxygen gas into the TEM column compared with the structural changes observed under high-vacuum conditions without the introduction of oxygen gas. These behaviors suggest that oxygen injection is an important factor in stabilizing the TiO2 nanotubes during the in situ TEM annealing process. The high-magnification TEM images of the double-wall TiO2 nanotubes revealed that the sintering of the inner wall can draw a clear distinction between the inner and outer walls. PMID:25401270

  19. Enhancement of the sweep efficiency of waterflooding operations by the in-situ microbial population of petroleum reservoirs

    Brown, L.R.; Vadie, A.A.; Stephens, J.O.; Azadpour, A.

    1995-12-31

    Live cores were obtained from five reservoirs using special precautions to prevent contamination by exogenous microorganisms and minimize exposure to oxygen. The depths from which the cores were obtained ranged from 2,705 ft to 6,568 ft. Core plugs were cut radially from live cores, encased in heat-shrink plastic tubes, placed in core holders, and fitted with inlets and outlets. Nutrient additions stimulated the in-situ microbial population to increase, dissolve stratal material, produce gases, and release oil. Reduction in flow through the core plugs was observed in some cases, while in other cases flow was increased, probably due to the dissolution of carbonates in the formation. A field demonstration of the ability of the in-situ microbial population to increase oil recovery by blocking the more permeable zones of the reservoir is currently underway. This demonstration is being conducted in the North Blowhorn Creek Unit situated in Lamar County, Alabama. Live cores were obtained from a newly drilled well in the field and tested as described above. The field project involves four test patterns each including one injector, four to five producers, and a comparable control injector with its four to five producers. Nutrient injection in the field began November 1994.

  20. Enhanced electron emission from carbon nanotubes through density control using in situ plasma treatment of catalyst metal

    We controlled the density of carbon nanotubes (CNTs) through in situ NH3 plasma pretreatment and investigated field emission properties with the density variation. Ni catalytic layer was transformed into small nanoparticles with NH3 plasma pretreatment time and power. As NH3 plasma pretreatment time was increased, the growth rate of grown CNTs was gradually decreased. Also, the density of CNTs reduced from 2x109 to 8x106/cm2 with an increase in NH3 plasma pretreatment time from 10 to 30 min for the Ni layer of 10 Aa. With a decrease in the density of CNTs, the emission current density was increased and turn on electric field was decreased. We obtained large and uniform emission current (about 9 mA/emission area of 0.49 cm2) from CNTs film with the density of 8x106/cm2

  1. In situ polymerization of graphene oxide and cyanate ester-epoxy with enhanced mechanical and thermal properties

    Ren, Fang; Zhu, Guangming; Ren, Penggang; Wang, Yongkun; Cui, Xiaoping

    2014-10-01

    Uniformly dispersed graphene oxide (GO)/cyanate ester (CE)-epoxy (EP) composites were successfully synthesized by in situ polymerization. Both the results of FT-IR and XPS verified that epoxide groups on the GO sheets reacted with cyanate group (Osbnd Ctbnd N) in the resin. These results could provide excellent dispersion of GO and strong interfacial interaction between GO and CE matrix. TEM confirmed that GO tended to be a single layer. XRD and SEM indicated that matrix molecules could be inserted into the interplanar spacing of GO. The mechanical properties and thermal behavior of the composites were investigated in detail. It is observed that GO reinforced EP-CE composites demonstrated improved mechanical properties and better thermal stability than that of EP-CE matrix, which make them suitable for use in aerospace applications and structural composites.

  2. In situ loading of well-dispersed silver nanoparticles on nanocrystalline magnesium oxide for real-time monitoring of catalytic reactions by surface enhanced Raman spectroscopy

    Zhang, Kaige; Li, Gongke; Hu, Yuling

    2015-10-01

    The surface-enhanced Raman spectroscopy (SERS) technique is of great importance for insight into the transient reaction intermediates and mechanistic pathways involved in heterogeneously catalyzed chemical reactions under actual reaction conditions, especially in water. Herein, we demonstrate a facile method for in situ synthesis of nanocrystalline magnesium oxide-Ag(0) (nano MgO-Ag(0)) hybrid nanomaterials with dispersed Ag nanoparticles (Ag NPs) on the surface of nanocrystalline magnesium oxide (nano MgO) via Sn2+ linkage and reduction. As a benefit from the synergy effect of nano MgO and Ag NPs, the nano MgO-Ag(0) exhibited both excellent SERS and catalytic activities for the reduction of 4-nitrothiophenol in the presence of NaBH4. The nano MgO-Ag(0) was used for real-time monitoring of the catalytic reaction process of 4-nitrothiophenol to 4-aminothiophenol in an aqueous medium by observing the SERS signals of the reactant, intermediate and final products. The intrinsic reaction kinetics and reaction mechanism of this reaction were also investigated. This SERS-based synergy technique provides a novel approach for quantitative in situ monitoring of catalytic chemical reaction processes.The surface-enhanced Raman spectroscopy (SERS) technique is of great importance for insight into the transient reaction intermediates and mechanistic pathways involved in heterogeneously catalyzed chemical reactions under actual reaction conditions, especially in water. Herein, we demonstrate a facile method for in situ synthesis of nanocrystalline magnesium oxide-Ag(0) (nano MgO-Ag(0)) hybrid nanomaterials with dispersed Ag nanoparticles (Ag NPs) on the surface of nanocrystalline magnesium oxide (nano MgO) via Sn2+ linkage and reduction. As a benefit from the synergy effect of nano MgO and Ag NPs, the nano MgO-Ag(0) exhibited both excellent SERS and catalytic activities for the reduction of 4-nitrothiophenol in the presence of NaBH4. The nano MgO-Ag(0) was used for real-time monitoring of the catalytic reaction process of 4-nitrothiophenol to 4-aminothiophenol in an aqueous medium by observing the SERS signals of the reactant, intermediate and final products. The intrinsic reaction kinetics and reaction mechanism of this reaction were also investigated. This SERS-based synergy technique provides a novel approach for quantitative in situ monitoring of catalytic chemical reaction processes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05718c

  3. Performance enhancements and muscular adaptations of a 16-week recreational football intervention for untrained women

    Bangsbo, Jens; Nielsen, Jens Jung; Mohr, Magni; Randers, Morten Bredsgaard; Krustrup, Birgitte Rejkjær; Brito, J.; Nybo, Lars; Krustrup, Peter

    -hydroxyacyl-CoA dehydrogenase (HAD) activity was 9% and 8%, respectively, higher (P<0.05) than before training in FG with no further changes during the last 12 weeks. In RG, CS increased (P<0.05) by 12% after 4 weeks and no significant increase was observed for HAD. In FG, the number of capillaries per fiber...... was 18% higher (P<0.05) after 16 weeks (2.44 +/- 0.15 vs 2.07 +/- 0.05 cap/fiber), with no significant difference for RG. No differences were observed between 0 and 16 weeks for CO. In conclusion, recreational women's football leads to significant increases in VO(2max), performance and muscular...

  4. Two-Step Resonance-Enhanced Desorption Laser Mass Spectrometry for In Situ Analysis of Organic-Rich Environments

    Getty, S. A.; Grubisic, A.; Uckert, K.; Li, X.; Cornish, T.; Cook, J. E.; Brinckerhoff, W. B.

    2016-01-01

    A wide diversity of planetary surfaces in the solar system represent high priority targets for in situ compositional and contextual analysis as part of future missions. The planned mission portfolio will inform our knowledge of the chemistry at play on Mars, icy moons, comets, and primitive asteroids, which can lead to advances in our understanding of the interplay between inorganic and organic building blocks that led to the evolution of habitable environments on Earth and beyond. In many of these environments, the presence of water or aqueously altered mineralogy is an important indicator of habitable environments that are present or may have been present in the past. As a result, the search for complex organic chemistry that may imply the presence of a feedstock, if not an inventory of biosignatures, is naturally aligned with targeted analyses of water-rich surface materials. Here we describe the two-step laser mass spectrometry (L2MS) analytical technique that has seen broad application in the study of organics in meteoritic samples, now demonstrated to be compatible with an in situ investigation with technique improvements to target high priority planetary environments as part of a future scientific payload. An ultraviolet (UV) pulsed laser is used in previous and current embodiments of laser desorption/ionization mass spectrometry (LDMS) to produce ionized species traceable to the mineral and organic composition of a planetary surface sample. L2MS, an advanced technique in laser mass spectrometry, is selective to the aromatic organic fraction of a complex sample, which can provide additional sensitivity and confidence in the detection of specific compound structures. Use of a compact two-step laser mass spectrometer prototype has been previously reported to provide specificity to key aromatic species, such as PAHs, nucleobases, and certain amino acids. Recent improvements in this technique have focused on the interaction between the mineral matrix and the organic analyte. The majority of planetary targets of astrobiological interest are characterized by the presence of water or hydrated mineral phases. Water signatures can indicate a history of available liquid water that may have played an important role in the chemical environment of these planetary surfaces and subsurfaces. The studies we report here investigate the influence of water content on the detectability of organics by L2MS in planetary analog samples.

  5. Enhanced Production of Botrallin and TMC-264 with in Situ Macroporous Resin Adsorption in Mycelial Liquid Culture of the Endophytic Fungus Hyalodendriella sp. Ponipodef12

    Haiyu Luo

    2014-09-01

    Full Text Available Hyalodendriella sp. Ponipodef12, an endophytic fungus from the hybrid “Neva” of Populus deltoides × P. nigra, is a high producer of the bioactive dibenzo-α-pyrones botrallin and TMC-264. However, both the botrallin and TMC-264 produced by Hyalodendriella sp. Ponipodef12 were retained as both intracellular and extracellular products. The aim of this study was to evaluate an in situ macroporous resin adsorption for enhancement of botrallin and TMC-264 production in mycelial liquid culture of Hyalodendriella sp. Ponipodef12. Production of botrallin and TMC-264 was most effectively enhanced by macroporous resin DM-301 among the thirteen nonionic macroporous resins tested. The highest botrallin yield (51.47 mg/L, which was 2.29-fold higher than the control at 22.49 mg/L was obtained by adding resin DM-301 at 4.38% (g/mL to the culture broth on day 24 and allowing a period of 4 days for adsorption. The highest TMC-264 yield reached 47.74 mg/L, which was 11.76-fold higher than that of the control (4.06 mg/L, and was achieved by adding DM-301 resin at 4.38% (w/v in the culture broth on day 24 and allowing a period of 6 days for adsorption. The results show that in situ resin adsorption is an effective strategy for enhancing production of botrallin and TMC-264, and also for facilitating their recovery from mycelial liquid culture of Hyalodendriella sp. Ponipodef12.

  6. In situ spectroscopic ellipsometry study of TiO2 films deposited by plasma enhanced chemical vapour deposition

    TiO2 thin films of 300400 nm were deposited at low pressure (3 mTorr) and temperature (b). The impact of growth interruptions on the film characteristics was studied by in situ spectroscopic ellipsometry (SE), scanning electron microscopy (SEM) and X-ray diffraction. The interruptions were carried out by stopping the plasma generation and gas injection once the increase of the layer thickness during each deposition step was about 100 nm. Suitable ellipsometric models were built to account for the structural and optical differences among the layers grown at different stages. When no bias is applied or Vb = ?10 V, the films deposited with and without interruptions are composed of a dense layer near substrate, an intermediate gradient layer and a top roughness layer. But the growth interruptions result in an increase of the dense layer thickness and a decrease of surface roughness. The discrepancy of the refractive index measured by SE between bottom and upper layers can be reduced by growth interruptions or biasing the substrate. In the case of Vb = ?50 V, the film becomes well organized, the top surface appears smoother, and the refractive index can be increased greatly, without significant effect of growth interruptions.

  7. Usage of waste products from thermal recycling of plastics waste in enhanced oil recovery or in-situ coal conversion

    Fink, M.; Fink, J.K. [Montanuniversitaet Leoben (Austria)

    1998-09-01

    In this contribution a thermal method for crude oil mobilization and in-situ liquefaction of coal is discussed, which will finally yield more organic material, as which has been put in from plastics waste originally into the process. The conversion product from thermal treatment is pumped down into exhausted crude oil reservoirs, where the hydrogen can degrade the residual high viscous oil to cause it to become more prone to flow so that it can be recovered. Such a process will envision two goals: 1. more organic raw material (as crude oil) will be recovered than is initially put in as waste product. 2. atmospheric pollutants from the conversion plant will be trapped in the reservoir, which simplifies the construction of the plant. An analogous process may be performed with coal seams. Coal seams with their high porosity and large specific surface are believed to be in particular useful to filter atmospheric pollutants. Depending on the type of coal the mobilization of organic material by this process may be in the background. (orig./SR)

  8. In situ generation of steam and alkaline surfactant for enhanced oil recovery using an exothermic water reactant (EWR)

    Robertson, Eric P

    2011-05-24

    A method for oil recovery whereby an exothermic water reactant (EWR) encapsulated in a water soluble coating is placed in water and pumped into one or more oil wells in contact with an oil bearing formation. After the water carries the EWR to the bottom of the injection well, the water soluble coating dissolves and the EWR reacts with the water to produce heat, an alkali solution, and hydrogen. The heat from the EWR reaction generates steam, which is forced into the oil bearing formation where it condenses and transfers heat to the oil, elevating its temperature and decreasing the viscosity of the oil. The aqueous alkali solution mixes with the oil in the oil bearing formation and forms a surfactant that reduces the interfacial tension between the oil and water. The hydrogen may be used to react with the oil at these elevated temperatures to form lighter molecules, thus upgrading to a certain extent the oil in situ. As a result, the oil can flow more efficiently and easily through the oil bearing formation towards and into one or more production wells.

  9. Two-stage in situ gas stripping for enhanced butanol fermentation and energy-saving product recovery

    Xue, C; Zhao, JB; Liu, FF; Lu, CC; Yang, ST; Bai, FW

    2013-05-01

    Two-stage gas stripping for butanol recovery from acetone-butanol-ethanol (ABE) fermentation with Clostridium acetobutylicum JB200 in a fibrous bed bioreactor was studied. Compared to fermentation without in situ gas stripping, more ABE (10.0 g/L acetone, 19.2 g/L butanol, 1.7 g/L ethanol vs. 7.9 g/L acetone, 16.2 g/L butanol, 1.4 g/L ethanol) were produced, with a higher butanol yield (0.25 g/g vs. 0.20 g/g) and productivity (0.40 g/L.h vs. 0.30 g/L-h) due to reduced butanol inhibition. The first-stage gas stripping produced a condensate containing 175.6 g/L butanol (227.0 g/L ABE), which after phase separation formed an organic phase containing 612.3 g/L butanol (660.7 g/L ABE) and an aqueous phase containing 101.3 g/L butanol (153.2 g/L ABE). After second-stage gas stripping, a highly concentrated product containing 420.3 g/L butanol (532.3 g/L ABE) was obtained. The process is thus effective in producing high-titer butanol that can be purified with much less energy. (C) 2012 Elsevier Ltd. All rights reserved.

  10. In situ growth of TiO2 in interlayers of expanded graphite for the fabrication of TiO2-graphene with enhanced photocatalytic activity.

    Jiang, Baojiang; Tian, Chungui; Zhou, Wei; Wang, Jianqiang; Xie, Ying; Pan, Qingjiang; Ren, Zhiyu; Dong, Youzhen; Fu, Dan; Han, Jiale; Fu, Honggang

    2011-07-18

    We present a facile route for the preparation of TiO(2)-graphene composites by in situ growth of TiO(2) in the interlayer of inexpensive expanded graphite (EG) under solvothermal conditions. A vacuum-assisted technique combined with the use of a surfactant (cetyltrimethylammonium bromide) plays a key role in the fabrication of such composites. Firstly, the vacuum environment promotes full infusion of the initial solution containing Ti(OBu)(4) and the surfactant into the interlayers of EG. Subsequently, numerous TiO(2) nanoparticles uniformly grow in situ in the interlayers with the help of the surfactant, which facilitates the exfoliation of EG under the solvothermal conditions in ethanol, eventually forming TiO(2)-graphene composites. The as-prepared samples have been characterized by Raman and FTIR spectroscopies, SEM, TEM, AFM, and thermogravimetic analysis. It is shown that a large number of TiO(2) nanoparticles homogeneously cover the surface of high-quality graphene sheets. The graphene exhibits a multi-layered structure (5-7 layers). Notably, the TiO(2)-graphene composite (only 30 wt?% of which is TiO(2)) synthesized by subsequent thermal treatment at high temperature under nitrogen shows high photocatalytic activity in the degradation of phenol under visible and UV lights in comparison with bare Degussa P25. The enhanced photocatalytic performance is attributed to increased charge separation, improved light absorbance and light absorption width, and high adsorptivity for pollutants. PMID:21656583

  11. Characterization of HfOxNy thin film formation by in-situ plasma enhanced atomic layer deposition using NH3 and N2 plasmas

    Highlights: • Analysis of PE-ALD grown HfON thin films using NH3 and N2 plasmas. • PE-ALD grown HfON film showed high dielectric constant and thermal stability. • PE-ALD grown HfON film suppressed the interfacial layer. • High leakage current of HfON film was caused by bandgap lowing and band offset. - Abstract: The structural and electrical characteristics of in-situ nitrogen-incorporated plasma enhanced atomic layer deposition (PE-ALD) HfOxNy thin films using NH3 and N2 plasmas as reactants were comparatively studied. The HfOxNy test structures prepared using NH3 and N2 plasmas were analyzed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and high resolution transmission electron microscopy (HR-TEM) to investigate the chemical composition, crystallinity, and cross-sectional layers including the interfacial layer, respectively. By utilizing NH3 and N2 plasmas, the nitrogen-incorporated HfOxNy thin films fabricated by in-situ PE-ALD showed a high dielectric constant and thermal stability, which suppresses the interfacial layer and increases the crystallization temperature. The high leakage current densities of the HfOxNy thin film test structures fabricated using NH3 and N2 plasmas caused by lowering the energy bandgap and band offset are related to the Hf−N bond ratio and dielectric constant

  12. In situ vertical profiles of aerosol extinction, mass, and composition over the southeast United States during SENEX and SEAC4RS: observations of a modest aerosol enhancement aloft

    N. L. Wagner

    2015-02-01

    Full Text Available Vertical profiles of submicron aerosol over the southeastern United States (SEUS during the summertime from in situ aircraft-based measurements were used to construct aggregate profiles of chemical, microphysical, and optical properties. Shallow cumulus convection was observed during many profiles. These conditions enhance vertical transport of trace gases and aerosol and create a cloudy transition layer on top of the sub-cloud mixed layer. The trace gas and aerosol concentrations in the transition layer were modeled as a mixture with contributions from the mixed layer below and the free troposphere above. The amount of vertical mixing, or entrainment of air from the free troposphere, was quantified using the observed mixing ratio of carbon monoxide (CO. Although the median aerosol mass, extinction, and volume decreased with altitude in the transition layer, they were ~10% larger than expected from vertical mixing alone. This enhancement was likely due to secondary aerosol formation in the transition layer. Although the transition layer enhancements of the particulate sulfate and organic aerosol (OA were both similar in magnitude, only the enhancement of sulfate was statistically significant. The column integrated extinction, or aerosol optical depth (AOD, was calculated for each individual profile, and the transition layer enhancement of extinction typically contributed less than 10% to the total AOD. Our measurements and analysis were motivated by two recent studies that have hypothesized an enhanced layer of secondary organic aerosol (SOA aloft to explain the summertime enhancement of AOD (23 times greater than winter over the southeastern United States. In contrast to this hypothesis, the modest enhancement we observed in the transition layer was not dominated by OA and was not a large fraction of the summertime AOD.

  13. Cavity-Enhanced Gas Analyzer for In-Situ Sampling of Biogenic Gases and Their Isotopes Project

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project concerns the novel application of cavity-enhanced absorption spectroscopy to quantify biogenic gases (CH4,...

  14. Efficient Blue-Colored Solid-State Dye-Sensitized Solar Cells: Enhanced Charge Collection by Using an in Situ Photoelectrochemically Generated Conducting Polymer Hole Conductor.

    Zhang, Jinbao; Vlachopoulos, Nick; Hao, Yan; Holcombe, Thomas W; Boschloo, Gerrit; Johansson, Erik M J; Grätzel, Michael; Hagfeldt, Anders

    2016-05-18

    A high power conversion efficiency (PCE) of 5.5 % was achieved by efficiently incorporating a diketopyrrolopyrrole-based dye with a conducting polymer poly(3,4-ethylenediothiophene) (PEDOT) hole-transporting material (HTM) that was formed in situ, compared with a PCE of 2.9 % for small molecular spiro-OMeTAD-based solid-state dye solar cells (sDSCs). The high PCE for PEDOT-based sDSCs is mainly attributed to the significantly enhanced charge-collection efficiency, as a result of the three-order-of-magnitude higher hole conductivity (0.53 S cm(-1) ) compared with that of the widely used low molecular weight HTM spiro-OMeTAD (3.5×10(-4)  S cm(-1) ). PMID:26919196

  15. Facile in situ solvothermal method to synthesize MWCNT/SnIn4S8 composites with enhanced visible light photocatalytic activity

    Highlights: • MWCNT/SnIn4S8 composites were facilely fabricated via in situ solvothermal method. • MWCNT/SnIn4S8 composites exhibited significantly enhanced visible-light activity. • MWCNT/SnIn4S8 composites showed remarkable visible light photocatalytic activity. • MWCNT/SnIn4S8 composites exhibited excellent photo-stability. • Possible photocatalytic mechanism under visible-light irradiation was proposed. - Abstract: Superior photocatalytic activity could be achieved by multi-walled carbon nanotube (MWCNT) incorporated in the porous assembly of marigold-like SnIn4S8 heterostructures synthesized by a flexible in-situ solvothermal method. The as-prepared MWCNT/SnIn4S8 composites were well-characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalytic properties of the as-prepared samples were tested by photo-degradation of aqueous malachite green (MG) under the irradiation of visible light. It was found that the MWCNT/SnIn4S8 composites showed enhanced visible light photocatalytic activity for dye degradation, and an optimum photocatalytic activity was observed over 3.0 wt.% MWCNT incorporated SnIn4S8 composites. The superior photocatalytic activity of MWCNT/SnIn4S8 composites could be ascribed to the existence of MWCNT which could serve as a good electron acceptor, mediator as well as the co-catalyst for dye degradation. The synergistic effect between SnIn4S8 and MWCNT in the composites facilitated the interfacial charge transfer driven by the excitation of SnIn4S8 under visible-light irradiation. Furthermore, a possible mechanism for the photocatalytic degradation of MWCNT/SnIn4S8 composites was also discussed

  16. Enhanced visible-light photocatalytic activities of Ag{sub 3}PO{sub 4}/MWCNT nanocomposites fabricated by facile in situ precipitation method

    Liu, Bo [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Li, Zhongyu, E-mail: zhongyuli@mail.tsinghua.edu.cn [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Changzhou Expansion New Stuff Technology Limited Company, Changzhou 213122 (China); Jilin Institute of Chemical Technology, Jilin 132022 (China); Xu, Song, E-mail: cyanine123@163.com [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Han, Dandan; Lu, Dayong [Jilin Institute of Chemical Technology, Jilin 132022 (China)

    2014-05-01

    Highlights: • Ag{sub 3}PO{sub 4}/MWCNT composites were facilely fabricated via in situ precipitation method. • Ag{sub 3}PO{sub 4}/MWCNT composites exhibited enhanced visible-light photocatalytic activity. • Ag{sub 3}PO{sub 4}/MWCNT composites showed good photostability compared with Ag{sub 3}PO{sub 4} particles. • Possible photocatalytic mechanism under visible-light irradiation was proposed. - Abstract: The Ag{sub 3}PO{sub 4}/MWCNT nanocomposites were facilely fabricated via in situ precipitation method by adding (NH{sub 4}){sub 2}HPO{sub 4} into the mixture of multi-walled carbon nanotube (MWCNT) and AgNO{sub 3} solution under stirring. The as-prepared Ag{sub 3}PO{sub 4}/MWCNT nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), the Brunauer–Emmett–Teller surface area (BET) and UV–vis diffuse reflectance spectroscopy. The TEM results showed that the Ag{sub 3}PO{sub 4} nanoparticles were distributed on the surface of MWCNT uniformly with an average diameter of 70 nm, indicating excellent loading result. The photocatalytic activities of Ag{sub 3}PO{sub 4}/MWCNT nanocomposites were investigated by degrading methylene blue (MB) and malachite green (MG) under visible-light irradiation. It was found that the Ag{sub 3}PO{sub 4}/MWCNT nanocomposite exhibited excellent photocatalytic performance with enhanced photocatalytic efficiency and good photostability compared with bare Ag{sub 3}PO{sub 4}. Furthermore, a possible mechanism for the photocatalytic oxidative degradation was also discussed.

  17. In situ growth of CdS nanoparticles on UiO-66 metal-organic framework octahedrons for enhanced photocatalytic hydrogen production under visible light irradiation

    Zhou, Jian-Jian; Wang, Rong; Liu, Xin-Ling; Peng, Fu-Min [School of Chemistry and Chemical Engineering and Innovation Lab for Clean Energy & Green Catalysis, Anhui University, Hefei 230601 (China); Li, Chuan-Hao, E-mail: chuanhao.li@yale.edu [School of Chemistry and Chemical Engineering and Innovation Lab for Clean Energy & Green Catalysis, Anhui University, Hefei 230601 (China); Department of Chemical & Environmental Engineering, Yale University, New Haven 06511 (United States); Teng, Fei [Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Sciences and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044 (China); Yuan, Yu-Peng, E-mail: yupengyuan@ahu.edu.cn [School of Chemistry and Chemical Engineering and Innovation Lab for Clean Energy & Green Catalysis, Anhui University, Hefei 230601 (China); Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Sciences and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044 (China)

    2015-08-15

    Graphical abstract: Enhanced photocatalytic hydrogen generation was achieved though constructing the CdS/UiO-66 MOF hybrids. In addition, the resultant hybrids show excellent photostability for hydrogen generation. - Highlights: • CdS nanoparticles were hydrothermally grown on UiO-66 octahedrons. • The resultant CdS/UiO-66 hybrids show enhanced photocatalytic H{sub 2} generation under visible light irradiation. • CdS/UiO-66 hybrids possess excellent photostability for long-term hydrogen generation. - Abstract: CdS nanoparticles acting as photosensitizer was grown in situ upon UiO-66 metal-organic framework octahedrons through a hydrothermal process. The resultant CdS/UiO-66 hybrid photocatalysts show remarkably active hydrogen evolution under visible light irradiation as compared to CdS and UiO-66 alone. The optimum hybrid with 16 wt% CdS loading shows a hydrogen production rate of 235 μmol h{sup −1}, corresponding to 1.2% quantum efficiency at 420 nm. The improved photocatalytic hydrogen production over hybrid CdS/UiO-66 is ascribed to the efficient interfacial charge transfer from CdS to UiO-66, which effectively suppresses the recombination of photogenerated electron-hole pairs and thereby enhancing the photocatalytic efficiency.

  18. In situ growth of CdS nanoparticles on UiO-66 metal-organic framework octahedrons for enhanced photocatalytic hydrogen production under visible light irradiation

    Graphical abstract: Enhanced photocatalytic hydrogen generation was achieved though constructing the CdS/UiO-66 MOF hybrids. In addition, the resultant hybrids show excellent photostability for hydrogen generation. - Highlights: • CdS nanoparticles were hydrothermally grown on UiO-66 octahedrons. • The resultant CdS/UiO-66 hybrids show enhanced photocatalytic H2 generation under visible light irradiation. • CdS/UiO-66 hybrids possess excellent photostability for long-term hydrogen generation. - Abstract: CdS nanoparticles acting as photosensitizer was grown in situ upon UiO-66 metal-organic framework octahedrons through a hydrothermal process. The resultant CdS/UiO-66 hybrid photocatalysts show remarkably active hydrogen evolution under visible light irradiation as compared to CdS and UiO-66 alone. The optimum hybrid with 16 wt% CdS loading shows a hydrogen production rate of 235 μmol h−1, corresponding to 1.2% quantum efficiency at 420 nm. The improved photocatalytic hydrogen production over hybrid CdS/UiO-66 is ascribed to the efficient interfacial charge transfer from CdS to UiO-66, which effectively suppresses the recombination of photogenerated electron-hole pairs and thereby enhancing the photocatalytic efficiency

  19. Resolution of an important discrepancy between remote and in-situ measurements of tropospheric BrO during Antarctic enhancements

    H. K. Roscoe

    2012-08-01

    Full Text Available Tropospheric BrO was measured by a ground-based remote-sensing spectrometer at Halley in Antarctica, and BrO was measured by remote-sensing spectrometers in space using similar spectral regions and Differential Optical Absorption Spectroscopy (DOAS analyses. Near-surface BrO was simultaneously measured at Halley by Chemical Ionisation Mass Spectrometry (CIMS, and in an earlier year near-surface BrO was measured at Halley over a long path by a DOAS spectrometer. During enhancement episodes, total amounts of tropospheric BrO from the ground-based remote-sensor were similar to those from space, but if we assume that the BrO was confined to the boundary layer they were very much larger than values measured by either near-surface technique. This large apparent discrepancy can be resolved if substantial amounts of BrO were in the free troposphere during most enhancement episodes. Amounts observed by the ground-based remote sensor at different elevation angles, and their formal inversions to vertical profiles, also show that much of the BrO was often in the free troposphere. This is consistent with the ~5 day lifetime of Bry, from the enhanced BrO observed during some Antarctic blizzards, and from aircraft measurements of BrO well above the surface in the Arctic.

  20. Microbiological-enhanced mixing across scales during in-situ bioreduction of metals and radionuclides at Department of Energy Sites

    Bioreduction is being actively investigated as an effective strategy for subsurface remediation and long-term management of DOE sites contaminated by metals and radionuclides (i.e. U(VI)). These strategies require manipulation of the subsurface, usually through injection of chemicals (e.g., electron donor) which mix at varying scales with the contaminant to stimulate metal reducing bacteria. There is evidence from DOE field experiments suggesting that mixing limitations of substrates at all scales may affect biological growth and activity for U(VI) reduction. Although current conceptual models hold that biomass growth and reduction activity is limited by physical mixing processes, a growing body of literature suggests that reaction could be enhanced by cell-to-cell interaction occurring over length scales extending tens to thousands of microns. Our project investigated two potential mechanisms of enhanced electron transfer. The first is the formation of single- or multiple-species biofilms that transport electrons via direct electrical connection such as conductive pili (i.e. nanowire) through biofilms to where the electron acceptor is available. The second is through diffusion of electron carriers from syntrophic bacteria to dissimilatory metal reducing bacteria (DMRB). The specific objectives of this work are (i) to quantify the extent and rate that electrons are transported between microorganisms in physical mixing zones between an electron donor and electron acceptor (e.g. U(IV)), (ii) to quantify the extent that biomass growth and reaction are enhanced by interspecies electron transport, and (iii) to integrate mixing across scales (e.g., microscopic scale of electron transfer and macroscopic scale of diffusion) in an integrated numerical model to quantify these mechanisms on overall U(VI) reduction rates. We tested these hypotheses with five tasks that integrate microbiological experiments, unique micro-fluidics experiments, flow cell experiments, and multi-scale numerical models. Continuous fed-batch reactors were used to derive kinetic parameters for DMRB, and to develop an enrichment culture for elucidation of syntrophic relationships in a complex microbial community. Pore and continuum scale experiments using microfluidic and bench top flow cells were used to evaluate the impact of cell-to-cell and microbial interactions on reaction enhancement in mixing-limited bioactive zones, and the mechanisms of this interaction. Some of the microfluidic experiments were used to develop and test models that considers direct cell-to-cell interactions during metal reduction. Pore scale models were incorporated into a multi-scale hybrid modeling framework that combines pore scale modeling at the reaction interface with continuum scale modeling. New computational frameworks for combining continuum and pore-scale models were also developed

  1. Microbiological-enhanced mixing across scales during in-situ bioreduction of metals and radionuclides at Department of Energy Sites

    Valocchi, Albert [Univ. of Illinois, Urbana-Champaign, IL (United States); Werth, Charles [Univ. of Texas, Austin, TX (United States); Liu, Wen-Tso [Univ. of Illinois, Urbana-Champaign, IL (United States); Sanford, Robert [Univ. of Illinois, Urbana-Champaign, IL (United States); Nakshatrala, Kalyan [Univ. of Houston, TX (United States)

    2015-10-20

    Bioreduction is being actively investigated as an effective strategy for subsurface remediation and long-term management of DOE sites contaminated by metals and radionuclides (i.e. U(VI)). These strategies require manipulation of the subsurface, usually through injection of chemicals (e.g., electron donor) which mix at varying scales with the contaminant to stimulate metal reducing bacteria. There is evidence from DOE field experiments suggesting that mixing limitations of substrates at all scales may affect biological growth and activity for U(VI) reduction. Although current conceptual models hold that biomass growth and reduction activity is limited by physical mixing processes, a growing body of literature suggests that reaction could be enhanced by cell-to-cell interaction occurring over length scales extending tens to thousands of microns. Our project investigated two potential mechanisms of enhanced electron transfer. The first is the formation of single- or multiple-species biofilms that transport electrons via direct electrical connection such as conductive pili (i.e. ‘nanowires’) through biofilms to where the electron acceptor is available. The second is through diffusion of electron carriers from syntrophic bacteria to dissimilatory metal reducing bacteria (DMRB). The specific objectives of this work are (i) to quantify the extent and rate that electrons are transported between microorganisms in physical mixing zones between an electron donor and electron acceptor (e.g. U(IV)), (ii) to quantify the extent that biomass growth and reaction are enhanced by interspecies electron transport, and (iii) to integrate mixing across scales (e.g., microscopic scale of electron transfer and macroscopic scale of diffusion) in an integrated numerical model to quantify these mechanisms on overall U(VI) reduction rates. We tested these hypotheses with five tasks that integrate microbiological experiments, unique micro-fluidics experiments, flow cell experiments, and multi-scale numerical models. Continuous fed-batch reactors were used to derive kinetic parameters for DMRB, and to develop an enrichment culture for elucidation of syntrophic relationships in a complex microbial community. Pore and continuum scale experiments using microfluidic and bench top flow cells were used to evaluate the impact of cell-to-cell and microbial interactions on reaction enhancement in mixing-limited bioactive zones, and the mechanisms of this interaction. Some of the microfluidic experiments were used to develop and test models that considers direct cell-to-cell interactions during metal reduction. Pore scale models were incorporated into a multi-scale hybrid modeling framework that combines pore scale modeling at the reaction interface with continuum scale modeling. New computational frameworks for combining continuum and pore-scale models were also developed

  2. AIDS–Related Pancreatic Burkitt ’S Lymphoma. EUS–FNA Enhanced Diagnosis with Fluorescence in Situ Hybridization (FISH

    Carlos Marra-López Valenciano

    2008-09-01

    Full Text Available Context Non-Hodgkin's lymphoma is a common complication in HIV-patients that most frequently affects the gastrointestinal tract. Primary pancreatic lymphomas and Burkitt Lymphoma involving the pancreas are uncommon. It is important to recognize them because can mimic an adenocarcinoma or pancreatitis, but their management is completely different. Case report We report a case of a forty-seven-year-old man who presented with an AIDS-related Burkitt Lymphoma with acute pancreatitis as initial manifestation. Initially patient was admitted with abdominal pain and high amylase levels. Computed tomography imaging was suggestive of acute pancreatitis. Later was found to be human immunodeficiency virus seropositive. 4-weeks later, a control computed tomography scan revealed growth of a well-defined large pancreatic mass, with diffuse enlargement of the gland, and a normal-appearing pancreatic duct. Consequently an endoscopic ultrasound-guided fine needle aspiration was performed with a 19-gauge needle and revealed a proliferation of medium lymphocytes, inconspicuous cytoplasm and frequent mitosis. The lymphocytes were positive for CD20 and CD10. The Ki-67 labeling index was almost 80%. BCL-2 and MYC FISH molecular analysis was performed and confirmed t(8;14(q24;q32. On the basis of these results, pancreatic Burkitt's lymphoma was diagnosed. Positive emission tomography scan completed staging and showed uptake in the pancreas and multiple metastasis. Accordingly patient received chemotherapy by PHETEMA BURKIMAB protocol, obtaining complete remission. Conclusion Pancreatic Lymphoma should be considered in differential diagnosis of pancreatic masses. EUS-FNA including flow cytometry and molecular analysis are useful techniques that may help to establish early diagnosis and prompt treatment avoiding unnecessary surgery.

  3. In situ vertical profiles of aerosol extinction, mass, and composition over the southeast United States during SENEX and SEAC4RS: observations of a modest aerosol enhancement aloft

    Wagner, N. L.; Brock, C. A.; Angevine, W. M.; Beyersdorf, A.; Campuzano-Jost, P.; Day, D.; de Gouw, J. A.; Diskin, G. S.; Gordon, T. D.; Graus, M. G.; Holloway, J. S.; Huey, G.; Jimenez, J. L.; Lack, D. A.; Liao, J.; Liu, X.; Markovic, M. Z.; Middlebrook, A. M.; Mikoviny, T.; Peischl, J.; Perring, A. E.; Richardson, M. S.; Ryerson, T. B.; Schwarz, J. P.; Warneke, C.; Welti, A.; Wisthaler, A.; Ziemba, L. D.; Murphy, D. M.

    2015-06-01

    Vertical profiles of submicron aerosol from in situ aircraft-based measurements were used to construct aggregate profiles of chemical, microphysical, and optical properties. These vertical profiles were collected over the southeastern United States (SEUS) during the summer of 2013 as part of two separate field studies: the Southeast Nexus (SENEX) study and the Study of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys (SEAC4RS). Shallow cumulus convection was observed during many profiles. These conditions enhance vertical transport of trace gases and aerosol and create a cloudy transition layer on top of the sub-cloud mixed layer. The trace gas and aerosol concentrations in the transition layer were modeled as a mixture with contributions from the mixed layer below and the free troposphere above. The amount of vertical mixing, or entrainment of air from the free troposphere, was quantified using the observed mixing ratio of carbon monoxide (CO). Although the median aerosol mass, extinction, and volume decreased with altitude in the transition layer, they were ~10 % larger than expected from vertical mixing alone. This enhancement was likely due to secondary aerosol formation in the transition layer. Although the transition layer enhancements of the particulate sulfate and organic aerosol (OA) were both similar in magnitude, only the enhancement of sulfate was statistically significant. The column integrated extinction, or aerosol optical depth (AOD), was calculated for each individual profile, and the transition layer enhancement of extinction typically contributed less than 10 % to the total AOD. Our measurements and analysis were motivated by two recent studies that have hypothesized an enhanced layer of secondary aerosol aloft to explain the summertime enhancement of AOD (2-3 times greater than winter) over the southeastern United States. The first study attributes the layer aloft to secondary organic aerosol (SOA) while the second study speculates that the layer aloft could be SOA or secondary particulate sulfate. In contrast to these hypotheses, the modest enhancement we observed in the transition layer was not dominated by OA and was not a large fraction of the summertime AOD.

  4. In situ nanoscale refinement by highly controllable etching of the (111) silicon crystal plane and its influence on the enhanced electrical property of a silicon nanowire

    Nanoscale refinement on a (100) oriented silicon-on-insulator (SOI) wafer was introduced by using tetra-methyl-ammonium hydroxide (TMAH, 25 wt%) anisotropic silicon etchant, with temperature kept at 50 °C to achieve precise etching of the (111) crystal plane. Specifically for a silicon nanowire (SiNW) with oxide sidewall protection, the in situ TMAH process enabled effective size reduction in both lateral (2.3 nm/min) and vertical (1.7 nm/min) dimensions. A sub-50 nm SiNW with a length of microns with uniform triangular cross-section was achieved accordingly, yielding enhanced field effect transistor (FET) characteristics in comparison with its 100 nm-wide pre-refining counterpart, which demonstrated the feasibility of this highly controllable refinement process. Detailed examination revealed that the high surface quality of the (111) plane, as well as the bulk depletion property should be the causes of this electrical enhancement, which implies the great potential of the as-made cost-effective SiNW FET device in many fields. (semiconductor materials)

  5. In-situ doping of erbium in hydrogenated amorphous carbon by low temperature metalorganic radio frequency plasma enhanced chemical vapor deposition

    Hsu, Hui-Lin; Leong, Keith R.; Halamicek, Michael [Department of Electrical and Computer Engineering, University of Toronto, ON M5S 3G4 (Canada); Teng, I-Ju [Centre for Interdisciplinary Science, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Mahtani, Pratish [Department of Electrical and Computer Engineering, University of Toronto, ON M5S 3G4 (Canada); Juang, Jenh-Yih [Centre for Interdisciplinary Science, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Jian, Sheng-Rui [Department of Materials Science and Engineering, I-Shou University, Kaohsiung 84001, Taiwan (China); Qian, Li, E-mail: l.qian@utoronto.ca [Department of Electrical and Computer Engineering, University of Toronto, ON M5S 3G4 (Canada); Kherani, Nazir P., E-mail: kherani@ecf.utoronto.ca [Department of Electrical and Computer Engineering, University of Toronto, ON M5S 3G4 (Canada); Department of Materials Science and Engineering, University of Toronto, ON M5S 3E4 (Canada)

    2014-11-03

    A significant improvement in the photoluminescence of erbium doped amorphous carbon (a-C:H(Er)) is reported. The effects of the RF power on the anode and cathode a-C:H films were investigated in terms of the microstructural and local bonding features. It was determined that Er doped a-C:H films should be placed on the anode to obtain wider bandgap and lower percentage of sp{sup 2} carbon bonding. The metalorganic compound, tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) Erbium(+ III) or Er(fod){sub 3}, was incorporated in-situ into an a-C:H host by metalorganic rf plasma enhanced chemical vapor deposition. This technique provides the capability of doping Er in a vertically uniform profile. The high erbium concentration (3.9 at.%), partial fluorination of the surrounding ligands, and the large optical bandgap of the host a-C:H are the primary factors that enable enhancement of the photoluminescence. - Highlights: High and uniform Er concentration (3.9 at.%) in a-C:H(Er) films is achieved. Room-temperature photoluminescence peaking at 1.54 ?m is demonstrated. Optically active Er{sup 3+} ions are preserved in as-grown samples at low growth temperature. Non-radiative C-H vibrational quenching is reduced by fluorination of a-C host. Metalorganic-RF-PECVD provides the potential of doping Er in vertically uniform profiles.

  6. Rational in-situ construction of three-dimensional reduced graphene oxide supported Li2S/C composite as enhanced cathode for rechargeable lithium-sulfur batteries

    Wang, D. H.; Xia, X. H.; Xie, D.; Niu, X. Q.; Ge, X.; Gu, C. D.; Wang, X. L.; Tu, J. P.

    2015-12-01

    The construction of advanced cathode materials is indispensable and vital for developing high-performance lithium-sulfur batteries. Herein, we develop a facile in-situ route to synthesize three-dimensional reduced graphene oxide supported Li2S/carbon composite (3D-rGO-Li2S/C). The Li2S/C nanoparticles are intimately anchored on the surface of 3D-rGO forming an integrated 3D porous composite. Due to the improved conductivity and reduced polysulfide dissolution, the 3D-rGO-Li2S/C cathode exhibits enhanced electrochemical performances with a high initial capacity of 819 mAh g-1 at 0.1C, as well as good cycling stability with a capacity retention of 415 mAh g-1 after 100 cycles at 1C. The integrated 3D conductive network is responsible for the enhancement of the electrochemical properties by providing fast ion/electron transfer and high mechanical stability.

  7. Facile in situ solvothermal method to synthesize MWCNT/SnIn{sub 4}S{sub 8} composites with enhanced visible light photocatalytic activity

    Ding, Chaoying; Tian, Li [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); College of Hua Loogeng, Changzhou University, Changzhou 213164 (China); Liu, Bo; Liang, Qian [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Li, Zhongyu, E-mail: zhongyuli@mail.tsinghua.edu.cn [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); College of Hua Loogeng, Changzhou University, Changzhou 213164 (China); Key Laboratory of Regional Environment and Ecoremediation (Ministry of Education), Shenyang University, Shenyang 110044 (China); Xu, Song [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Liu, Qiaoli; Lu, Dayong [Department of Materials Science and Engineering, Jilin Institute of Chemical Technology, Jilin 132022 (China)

    2015-06-05

    Highlights: • MWCNT/SnIn{sub 4}S{sub 8} composites were facilely fabricated via in situ solvothermal method. • MWCNT/SnIn{sub 4}S{sub 8} composites exhibited significantly enhanced visible-light activity. • MWCNT/SnIn{sub 4}S{sub 8} composites showed remarkable visible light photocatalytic activity. • MWCNT/SnIn{sub 4}S{sub 8} composites exhibited excellent photo-stability. • Possible photocatalytic mechanism under visible-light irradiation was proposed. - Abstract: Superior photocatalytic activity could be achieved by multi-walled carbon nanotube (MWCNT) incorporated in the porous assembly of marigold-like SnIn{sub 4}S{sub 8} heterostructures synthesized by a flexible in-situ solvothermal method. The as-prepared MWCNT/SnIn{sub 4}S{sub 8} composites were well-characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalytic properties of the as-prepared samples were tested by photo-degradation of aqueous malachite green (MG) under the irradiation of visible light. It was found that the MWCNT/SnIn{sub 4}S{sub 8} composites showed enhanced visible light photocatalytic activity for dye degradation, and an optimum photocatalytic activity was observed over 3.0 wt.% MWCNT incorporated SnIn{sub 4}S{sub 8} composites. The superior photocatalytic activity of MWCNT/SnIn{sub 4}S{sub 8} composites could be ascribed to the existence of MWCNT which could serve as a good electron acceptor, mediator as well as the co-catalyst for dye degradation. The synergistic effect between SnIn{sub 4}S{sub 8} and MWCNT in the composites facilitated the interfacial charge transfer driven by the excitation of SnIn{sub 4}S{sub 8} under visible-light irradiation. Furthermore, a possible mechanism for the photocatalytic degradation of MWCNT/SnIn{sub 4}S{sub 8} composites was also discussed.

  8. In situ construction of g-C3N4/g-C3N4 metal-free heterojunction for enhanced visible-light photocatalysis.

    Dong, Fan; Zhao, Zaiwang; Xiong, Ting; Ni, Zilin; Zhang, Wendong; Sun, Yanjuan; Ho, Wing-Kei

    2013-11-13

    The photocatalytic performance of the star photocatalyst g-C3N4 was restricted by the low efficiency because of the fast charge recombination. The present work developed a facile in situ method to construct g-C3N4/g-C3N4 metal-free isotype heterojunction with molecular composite precursors with the aim to greatly promote the charge separation. Considering the fact that g-C3N4 samples prepared from urea and thiourea separately have different band structure, the molecular composite precursors of urea and thiourea were treated simultaneously under the same thermal conditions, in situ creating a novel layered g-C3N4/g-C3N4 metal-free heterojunction (g-g CN heterojunction). This synthesis method is facile, economic, and environmentally benign using easily available earth-abundant green precursors. The confirmation of isotype g-g CN heterojunction was based on XRD, HRTEM, valence band XPS, ns-level PL, photocurrent, and EIS measurement. Upon visible-light irradiation, the photogenerated electrons transfer from g-C3N4 (thiourea) to g-C3N4 (urea) driven by the conduction band offset of 0.10 eV, whereas the photogenerated holes transfer from g-C3N4 (urea) to g-C3N4 (thiourea) driven by the valence band offset of 0.40 eV. The potential difference between the two g-C3N4 components in the heterojunction is the main driving force for efficient charge separation and transfer. For the removal of NO in air, the g-g CN heterojunction exhibited significantly enhanced visible light photocatalytic activity over g-C3N4 alone and physical mixture of g-C3N4 samples. The enhanced photocatalytic performance of g-g CN isotype heterojunction can be directly ascribed to efficient charge separation and transfer across the heterojunction interface as well as prolonged lifetime of charge carriers. This work demonstrated that rational design and construction of isotype heterojunction could open up a new avenue for the development of new efficient visible-light photocatalysts. PMID:24144400

  9. Differentiation of acute and four-week old myocardial infarct with Gd(ABE-DTTA-enhanced CMR

    Ruzsics Balazs

    2010-04-01

    Full Text Available Abstract Background Standard extracellular cardiovascular magnetic resonance (CMR contrast agents (CA do not provide differentiation between acute and older myocardial infarcts (MI. The purpose of this study was to develop a method for differentiation between acute and older myocardial infarct using myocardial late-enhancement (LE CMR by a new, low molecular weight contrast agent. Dogs (n = 6 were studied in a closed-chest, reperfused, double myocardial infarct model. Myocardial infarcts were generated by occluding the Left Anterior Descending (LAD coronary artery with an angioplasty balloon for 180 min, and four weeks later occluding the Left Circumflex (LCx coronary artery for 180 min. LE images were obtained on day 3 and day 4 after second myocardial infarct, using Gd(DTPA (standard extracellular contrast agent and Gd(ABE-DTTA (new, low molecular weight contrast agent, respectively. Triphenyltetrazolium chloride (TTC histomorphometry validated existence and location of infarcts. Hematoxylin-eosin and Masson's trichrome staining provided histologic evaluation of infarcts. Results Gd(ABE-DTTA or Gd(DTPA highlighted the acute infarct, whereas the four-week old infarct was visualized by Gd(DTPA, but not by Gd(ABE-DTTA. With Gd(ABE-DTTA, the mean SD signal intensity enhancement (SIE was 366 166% and 24 59% in the acute infarct and the four-week old infarct, respectively (P Conclusions Late enhancement CMR with separate administrations of standard extracellular contrast agent, Gd(DTPA, and the new low molecular weight contrast agent, Gd(ABE-DTTA, differentiates between acute and late subacute infarct in a reperfused, double infarct, canine model.

  10. Characterizing early contrast uptake of ductal carcinoma in situ with high temporal resolution dynamic contrast-enhanced MRI of the breast: a pilot study

    Improvements in the reliable diagnosis of preinvasive ductal carcinoma in situ (DCIS) by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are needed. In this study, we present a new characterization of early contrast kinetics of DCIS using high temporal resolution (HiT) DCE-MRI and compare it with other breast lesions and normal parenchyma. Forty patients with mammographic calcifications suspicious for DCIS were selected for HiT imaging using T1-weighted DCE-MRI with ∼7 s temporal resolution for 90 s post-contrast injection. Pixel-based and whole-lesion kinetic curves were fit to an empirical mathematical model (EMM) and several secondary kinetic parameters derived. Using the EMM parameterized and fitted concentration time curve for subsequent analysis allowed for calculation of kinetic parameters that were less susceptible to fluctuations due to noise. The parameters' initial area under the curve (iAUC) and contrast concentration at 1 min (C1min) provided the highest diagnostic accuracy in the task of distinguishing pathologically proven DCIS from normal tissue. There was a trend for DCIS lesions with solid architectural pattern to exhibit a negative slope at 1 min (i.e. increased washout rate) compared to those with a cribriform pattern (p < 0.04). This pilot study demonstrates the feasibility of quantitative analysis of early contrast kinetics at high temporal resolution and points to the potential for such an analysis to improve the characterization of DCIS. (note)

  11. Structure Modification Function of g-C3 N4 for Al2 O3 in the In Situ Hydrothermal Process for Enhanced Photocatalytic Activity.

    Li, Fa-tang; Liu, Shao-jia; Xue, Ya-bin; Wang, Xiao-jing; Hao, Ying-juan; Zhao, Jun; Liu, Rui-hong; Zhao, Dishun

    2015-07-01

    Heterojunctions of g-C3 N4 /Al2 O3 (g-C3 N4 =graphitic carbon nitride) are constructed by an in situ one-pot hydrothermal route based on the development of photoactive γ-Al2 O3 semiconductor with a mesoporous structure and a high surface area (188 m(2) g(-1) ) acting as electron acceptor. A structure modification function of g-C3 N4 for Al2 O3 in the hydrothermal process is found, which can be attributed to the coordination between unoccupied orbitals of the Al ions and lone-pair electrons of the N atoms. The as-synthesized heterojunctions exhibit much higher photocatalytic activity than pure g-C3 N4 . The hydrogen generation rate and the reaction rate constant for the degradation of methyl orange over 50 % g-C3 N4 /Al2 O3 under visible-light irradiation (λ>420 nm) are 2.5 and 7.3 times, respectively, higher than those over pristine g-C3 N4 . The enhanced activity of the heterojunctions is attributed to their large specific surface areas, their close contact, and the high interfacial areas between the components as well as their excellent adsorption performance, and efficient charge transfer ability. PMID:26043440

  12. Cooperative cathode electrode and in situ deposited copper for subsequent enhanced Cd(II) removal and hydrogen evolution in bioelectrochemical systems.

    Wang, Qiang; Huang, Liping; Pan, Yuzhen; Zhou, Peng; Quan, Xie; Logan, Bruce E; Chen, Hongbo

    2016-01-01

    Bioelectrochemical systems (BESs) were first operated in microbial fuel cell mode for recovering Cu(II), and then shifted to microbial electrolysis cells for Cd(II) reduction on the same cathodes of titanium sheet (TS), nickel foam (NF) or carbon cloth (CC). Cu(II) reduction was similar to all materials (4.79-4.88mg/Lh) whereas CC exhibited the best Cd(II) reduction (5.860.25mg/Lh) and hydrogen evolution (0.350.07m(3)/m(3)d), followed by TS (5.270.43mg/Lh and 0.150.02m(3)/m(3)d) and NF (4.960.48mg/Lh and 0.800.07m(3)/m(3)d). These values were higher than no copper controls by factors of 2.0 and 5.0 (TS), 4.2 and 2.0 (NF), and 1.8 and 7.0 (CC). These results demonstrated cooperative cathode electrode and in situ deposited copper for subsequent enhanced Cd(II) reduction and hydrogen production in BESs, providing an alternative approach for efficiently remediating Cu(II) and Cd(II) co-contamination with simultaneous hydrogen production. PMID:26528907

  13. Immobilization of serum albumin and peptide aptamer for EPC on polydopamine coated titanium surface for enhanced in-situ self-endothelialization.

    Chen, Zhuoyue; Li, Quanli; Chen, Jialong; Luo, Rifang; Maitz, Manfred F; Huang, Nan

    2016-03-01

    Restenosis and thrombosis are two major complications associated with vascular stents and grafts. The homing of circulating endothelial progenitor cells (EPCs) onto implant surfaces brings a new strategy to solve these problems by accelerating self -endothelialization in situ. Peptide aptamers with high affinity and specific recognition of EPCs can be immobilized to capture EPCs from the circulating blood. In this study, a biotinylated peptide aptamer (TPSLEQRTVYAK-GGGC-K-Biotin) for EPC, and bovine serum albumin (BSA) were co-immobilized onto titanium surface through avidin-biotin recognition to endow the surface with specific affinity for EPC and anti-platelet adhesion properties. Quartz crystal microbalance with dissipation (QCM-D), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and water contact angle measuring were adopted for coating characterization. EPC affinity and hemocompatibility of the coating were also investigated in vitro. The results demonstrated that aptamer and BSA co-immobilized surface significantly reduced platelet adhesion and fibrinogen adsorption/activation. Besides, such functional surface could remarkably enhance EPC adhesion, without affecting the behavior of endothelial cells (ECs) and smooth muscle cells (SMCs) obviously. The result shows the possibility of utilizing such a multifunctional surface in cardiovascular implants. PMID:26706525

  14. In-situ sonosynthesis of nano N-doped ZnO on wool producing fabric with photo and bio activities, cell viability and enhanced mechanical properties.

    Behzadnia, Amir; Montazer, Majid; Rad, Mahnaz Mahmoudi

    2015-08-01

    Here, a simple processing route is introduced for preparation of N-doped nano structure ZnO at 75-80°C using in-situ sonosynthesis method through hydrolysis of zinc acetate at pH≈9-10 adjusting with ammonia. Synthesis and fabrication of nano N-doped ZnO were carried out on the wool fabric through impregnation of the fabric in ultrasound bath using different concentrations of zinc acetate followed by curing. The antibacterial and antifungal activities of the treated fabrics were assessed against two common pathogenic bacteria including Escherichia coli, Staphylococcus aureus and the diploid fungus namely Candida albicans. The photo-catalytic activity of nano N-doped ZnO particles on the wool fabric was determined by degradation of Methylene Blue under daylight irradiation. Increasing zinc acetate and prolonged sonication time led to higher photo-catalytic activity as more dye stain degraded from the stained treated fabric under daylight. Higher photo-catalytic activity was observed on the nano N-doped ZnO sonotreated wool fabric having more hydrophilicity. Finally, the treatment indicated no negative effect on the fabric safety while reduced alkaline solubility and yellowness even enhanced the fabric tensile strength. The response surface methodology was also utilized to optimize the wool fabric treatment conditions. PMID:26057020

  15. In situ plasmonic Ag nanoparticle anchored TiO2 nanotube arrays as visible-light-driven photocatalysts for enhanced water splitting.

    Ge, Ming-Zheng; Cao, Chun-Yan; Li, Shu-Hui; Tang, Yu-Xin; Wang, Lu-Ning; Qi, Ning; Huang, Jian-Ying; Zhang, Ke-Qin; Al-Deyab, S S; Lai, Yue-Kun

    2016-02-25

    An ultrasonication-assisted in situ deposition strategy was utilised to uniformly decorate plasmonic Ag nanoparticles on vertically aligned TiO2 nanotube arrays (NTAs) to construct a Ag@TiO2 NTA composite. The Ag nanoparticles act as efficient surface plasmon resonance (SPR) photosensitizers to drive photocatalytic water splitting under visible light irradiation. The Ag nanoparticles were uniformly deposited on the surface and inside the highly oriented TiO2 nanotubes. The visible-light-driven hydrogen production activities of silver nanoparticle anchored TiO2 nanotube array photocatalysts were evaluated using methanol as a sacrificial reagent in water under a 500 W Xe lamp with a UV light cutoff filter (λ ≥ 420 nm). It was found that the hydrogen production rate of the Ag@TiO2 NTAs prepared with ultrasonication-assisted deposition for 5 min was approximately 15 times higher than that of its pristine TiO2 NTAs counterpart. The highly efficient photocatalytic hydrogen evolution is attributed to the SPR effect of Ag for enhanced visible light absorption and boosting the photogenerated electron-hole separation/transfer. This strategy is promising for the design and construction of high efficiency TiO2 based photocatalysts for solar energy conversion. PMID:26878901

  16. In-Situ Generation of Oxide Nanowire Arrays from AgCuZn Alloy Sulfide with Enhanced Electrochemical Oxygen-Evolving Performance.

    Xie, Minghao; Ai, Shiqi; Yang, Jian; Yang, Yudi; Chen, Yihan; Jin, Yong

    2015-08-12

    In this study, AgCuZn sulfide is fabricated on the surface of AgCuZn alloys by hydrothermal sulfuration. This ternary metal sulfide is equipped with enhanced activity toward oxygen evolution reaction (OER) in an alkaline electrolyte. Through comparison of the alloys with diverse compositions, we find out the best electrochemical property of a particular alloy sulfide forming on a AgCuZn substrate (Ag:Cu:Zn=43:49:8). The alloy sulfide exhibits an onset overpotential (?) of 0.27 V with a Tafel slope of 952 mV dec(-1) and a current density of 130 mA cm(-2) at ? of 0.57 V. Moreover, the obtained AgCuZn sulfide displays excellent stability, where the current density can increase to 130% of the initial value after a water electrolysis test for 100,000 s (27.7 h). Through investigating the electrode before and after the electrocatalysis, we find a remarkable activated process during which self-supported copper-silver oxide nanowire (CuO-Ag2O NW) arrays in situ form on the surface of the electrode. This work provides a feasible strategy for synthesis of high performance nonprecious metal electrocatalysts for water splitting. PMID:26181359

  17. Enhanced lithium storage in a VO2(B)-multiwall carbon nanotube microsheet composite prepared via an in situ hydrothermal process

    A novel VO2(B)-multiwall carbon nanotube (MWCNT) composite with a sheet-like morphology was synthesized by a simple in situ hydrothermal process. The morphology and structural properties of the samples were investigated by X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). FE-SEM observations demonstrated that the nanosheets are frequently grown together in the form of bundles composed of numerous nanosheets, each with a smooth surface and a typical length of 300-500 nm, width of 50-150 nm, and thickness of 10-50 nm. Electrochemical measurements were carried out using different discharge cut-off voltages. Electrochemical tests show that the VO2(B)-MWCNT composite cathode features long-term cycling stability and high discharge capacity (177 mAh g-1) in the voltage range of 2.0-3.25 V at 1 C with a capacity retention of 92% after 100 cycles. The electrochemical impedance spectra (EIS) indicate that the VO2(B)-MWCNT composite electrode has very low charge-transfer resistance compared with pure VO2(B), indicating the enhanced ionic conductivity of the VO2(B)-MWCNT composite. The enhanced cycling stability is attributed to the fact that the VO2(B)-MWCNT composite can prevent the aggregation of active materials, accommodate the large volume variation, and maintain good electronic contact. We strongly believe that the VO2(B)-MWCNT composite can be considered as a potential cathode material for lithium-ion batteries.

  18. In situ formation of a ZnO/ZnSe nanonail array as a photoelectrode for enhanced photoelectrochemical water oxidation performance

    Wang, Liyang; Tian, Guohui; Chen, Yajie; Xiao, Yuting; Fu, Honggang

    2016-04-01

    In this study, a ZnO/ZnSe nanonail array was prepared via a two-step sequential hydrothermal synthetic route. In this synthetic process, the ZnO nanorod array was first grown on a fluorine-doped tin oxide (FTO) substrate using a seed-mediated growth approach via the hydrothermal process. Then, the ZnO nanonail array was obtained via in situ growth of ZnSe nano caps onto the ZnO nanorod array via a hydrothermal process in the presence of a Se source. The surface morphology and amount of ZnSe grown on the surface of the ZnO nanorods can be regulated by varying the reaction time and reactant concentration. Compared with pure ZnO nanorods, this unique nanonail array heterostructure exhibits enhanced visible light absorption. The transient photocurrent condition, in combination with steady-state and time-resolved photoluminescence spectroscopy, reveals that the ZnO/ZnSe nanonail array electrode has the highest charge separation rate, highest electron injection efficiency, and highest chemical stability. The photocurrent density of the ZnO/ZnSe nanonail array heterostructure reaches 1.01 mA cm-2 at an applied potential of 0.1 V (vs. Ag/AgCl), which is much higher than that of the ZnO/ZnSe nanorod array (0.71 mA cm-2), the pristine ZnO nanorod array (0.39 mA cm-2), and the ZnSe electrode (0.21 mA cm-2), indicating its significant visible light driven activities for photoelectrochemical water oxidation. This unique morphology of nail-capped nanorods might be important for providing better insight into the correlation between heterostructure and photoelectrochemical activity.In this study, a ZnO/ZnSe nanonail array was prepared via a two-step sequential hydrothermal synthetic route. In this synthetic process, the ZnO nanorod array was first grown on a fluorine-doped tin oxide (FTO) substrate using a seed-mediated growth approach via the hydrothermal process. Then, the ZnO nanonail array was obtained via in situ growth of ZnSe nano caps onto the ZnO nanorod array via a hydrothermal process in the presence of a Se source. The surface morphology and amount of ZnSe grown on the surface of the ZnO nanorods can be regulated by varying the reaction time and reactant concentration. Compared with pure ZnO nanorods, this unique nanonail array heterostructure exhibits enhanced visible light absorption. The transient photocurrent condition, in combination with steady-state and time-resolved photoluminescence spectroscopy, reveals that the ZnO/ZnSe nanonail array electrode has the highest charge separation rate, highest electron injection efficiency, and highest chemical stability. The photocurrent density of the ZnO/ZnSe nanonail array heterostructure reaches 1.01 mA cm-2 at an applied potential of 0.1 V (vs. Ag/AgCl), which is much higher than that of the ZnO/ZnSe nanorod array (0.71 mA cm-2), the pristine ZnO nanorod array (0.39 mA cm-2), and the ZnSe electrode (0.21 mA cm-2), indicating its significant visible light driven activities for photoelectrochemical water oxidation. This unique morphology of nail-capped nanorods might be important for providing better insight into the correlation between heterostructure and photoelectrochemical activity. Electronic supplementary information (ESI) available: SEM, EDS, XPS and photocurrent test. See DOI: 10.1039/c6nr01969b

  19. Electrochemical and in-situ Surface-Enhanced Raman Spectroscopic (SERS) study of passive films formed on low-carbon steel in highly alkaline environments

    Mancio, Mauricio

    In reinforced concrete, a passive layer forms because of the alkaline conditions in the pores of the cement paste, where large concentrations of hydroxides create a solution with pH typically between 12 and 14. The corrosion resistance of the material depends on the characteristics and integrity of the passive film; however, currently very limited information is available about the passive films formed on carbon steel under such conditions. This work presents an electrochemical and in-situ Surface-Enhanced Raman Spectroscopic (SERS) study of passive films formed on low-carbon steel in highly alkaline environments. More specifically, the study focuses on the characterization of the films formed on ASTM A36 steel reinforcing bar exposed to aqueous solutions that aim to reproduce the chemistry of the environment typically found within the cement paste. Electrochemical techniques such as cyclic potentiodynamic polarization curves, galvanostatic cathodic polarization and linear polarization resistance were employed, in addition to in-situ Surface Enhanced Raman Spectroscopy (SERS). The experimental setup was built in a way that SERS experiments could be performed simultaneously with potentiodynamic polarization curves, enabling a detailed analysis of the formation and reduction of the surface films as a function of applied potential. Three solutions with different pH levels were used for the polarization and SERS experiments, namely 0.55M KOH + 0.16M NaOH ([OH-]=0.71), 0.08M KOH + 0.02M NaOH ([OH-]=0.10) and 0.008M KOH + 0.002M NaOH ([OH-]=0.01). Additional NaOH solutions in which the pH was varied from 13 to 9 and the ionic strength from 10 -5 to 10-1 were prepared for a pilot study using linear polarization resistance. Results show that the features observed in the cyclic potentiodynamic polarization curves correlated well with the potential arrests observed in the GCP plots as well as with the changes observed in the SERS spectra, providing valuable information about the formation of passive films on carbon steel in each of the environments studied in this research. Although there are key differences among the films formed in the different solutions tested---particularly regarding their thickness and protectiveness---once the film-formation processes had been completed, generally the films were characterized by an inner layer of Fe(II) and an outer layer of Fe(III). A Fe(OH)2-like species appears consistently as dominating the inner Fe(II) layer, while the outer typically composed mostly by gamma-Fe2O3 and/or gamma-FeOOH. Film thickness varied from about 22 nm to 266 nm depending on the pH of the solution, and decreased as pH was reduced.

  20. In situ plasmonic Ag nanoparticle anchored TiO2 nanotube arrays as visible-light-driven photocatalysts for enhanced water splitting

    Ge, Ming-Zheng; Cao, Chun-Yan; Li, Shu-Hui; Tang, Yu-Xin; Wang, Lu-Ning; Qi, Ning; Huang, Jian-Ying; Zhang, Ke-Qin; Al-Deyab, S. S.; Lai, Yue-Kun

    2016-02-01

    An ultrasonication-assisted in situ deposition strategy was utilised to uniformly decorate plasmonic Ag nanoparticles on vertically aligned TiO2 nanotube arrays (NTAs) to construct a Ag@TiO2 NTA composite. The Ag nanoparticles act as efficient surface plasmon resonance (SPR) photosensitizers to drive photocatalytic water splitting under visible light irradiation. The Ag nanoparticles were uniformly deposited on the surface and inside the highly oriented TiO2 nanotubes. The visible-light-driven hydrogen production activities of silver nanoparticle anchored TiO2 nanotube array photocatalysts were evaluated using methanol as a sacrificial reagent in water under a 500 W Xe lamp with a UV light cutoff filter (λ >= 420 nm). It was found that the hydrogen production rate of the Ag@TiO2 NTAs prepared with ultrasonication-assisted deposition for 5 min was approximately 15 times higher than that of its pristine TiO2 NTAs counterpart. The highly efficient photocatalytic hydrogen evolution is attributed to the SPR effect of Ag for enhanced visible light absorption and boosting the photogenerated electron-hole separation/transfer. This strategy is promising for the design and construction of high efficiency TiO2 based photocatalysts for solar energy conversion.An ultrasonication-assisted in situ deposition strategy was utilised to uniformly decorate plasmonic Ag nanoparticles on vertically aligned TiO2 nanotube arrays (NTAs) to construct a Ag@TiO2 NTA composite. The Ag nanoparticles act as efficient surface plasmon resonance (SPR) photosensitizers to drive photocatalytic water splitting under visible light irradiation. The Ag nanoparticles were uniformly deposited on the surface and inside the highly oriented TiO2 nanotubes. The visible-light-driven hydrogen production activities of silver nanoparticle anchored TiO2 nanotube array photocatalysts were evaluated using methanol as a sacrificial reagent in water under a 500 W Xe lamp with a UV light cutoff filter (λ >= 420 nm). It was found that the hydrogen production rate of the Ag@TiO2 NTAs prepared with ultrasonication-assisted deposition for 5 min was approximately 15 times higher than that of its pristine TiO2 NTAs counterpart. The highly efficient photocatalytic hydrogen evolution is attributed to the SPR effect of Ag for enhanced visible light absorption and boosting the photogenerated electron-hole separation/transfer. This strategy is promising for the design and construction of high efficiency TiO2 based photocatalysts for solar energy conversion. Electronic supplementary information (ESI) available: EDS and mapping spectra of Ag@TiO2 NTAs with an ultrasonication-assisted deposition time of 5 min, the size distribution of Ag nanoparticles of Ag@TiO2 NTAs with different deposition times, SEM images and EDS spectra of TiO2 NTAs with an ultrasonication-assisted deposition time of 5 min with 5, 20, and 40 mM AgNO3, photocurrent responses and hydrogen production rate of as-prepared pure TiO2 NTAs and Ag@TiO2 NTAs with an ultrasonication-assisted deposition time of 5 min with different concentrations of AgNO3. See DOI: 10.1039/c5nr08341a

  1. Enhanced cycle stability of micro-sized Si/C anode material with low carbon content fabricated via spray drying and in situ carbonization

    Highlights: • Micro-sized Si/C composites were fabricated via. spray drying and carbonization. • Multi-morphology carbon was formed in the Si/C composites. • Si/C composite with 5.6 wt.% C provides significant improved cycling stability. • Multi-morphology carbon plays effective role in improving the electrochemical property. • The method provides potential for mass production of superior Si-based anode materials. - Abstract: Micro-sized Si/C composites with in situ introduced carbon of multi-morphology were fabricated via spray drying a suspension of commercial micro-sized Si and citric acid followed by a carbonization. Different ratios of Si to citric acid were used to optimize the composition and structure of the composites and thus the electrochemical performance. Carbon flakes including crooked and flat ones were well dispersed in between the Si particles, forming Si/C composites. Floc-like carbon layers and carbon fragments were also found to cover partially the Si particles. The Si/C composite with a low carbon content of 5.6 wt.% provides an initial reversible capacity of 2700 mA h/g and a capacity of 1860 mA h/g after 60 cycles at a current density of 100 mA/g as anode material for lithium-ion batteries (LIBs), which are much higher than those of pristine Si and the Si/C composites with higher carbon content. The mechanism of the enhancement of electrochemical performance of the micro-sized Si/C composite is discussed. The fabrication method and the structure design of the composites offer valuable potential in developing adaptable Si-based anode materials for industrial applications

  2. In situ assembly of well-dispersed Au nanoparticles on TiO2/ZnO nanofibers: A three-way synergistic heterostructure with enhanced photocatalytic activity

    Graphical abstract: We describe a route to synthesize TiO2/ZnO/Au three-way synergistic heterostructure nanofibers with high efficiency photocatalysts. Highlights: ? Synthesis of tri-component TiO2/ZnO/Au nanofibers. ? TiO2/ZnO/Au nanofibers showed excellent photocatalytic activity. ? Easy photocatalyst separation and reuse. - Abstract: The TiO2/ZnO nanofibers embedded by Au nanoparticles (TiO2/ZnO/Au NFs) were fabricated by combining the electrospinning technique (for TiO2/ZnO nanofibers) and an in situ reduction approach (for Au nanoparticles). X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electronmicroscopy, X-ray photoelectron spectroscopy, UVvis diffuse reflectance spectroscopy and photoluminescence spectroscopy, were used to characterize the as-synthesized nanofibers. The results showed that small Au nanoparticles (Au NPs) were well dispersed on the TiO2/ZnO nanofibers (TiO2/ZnO NFs). And, the TiO2/ZnO/Au nanofibers showed high charge separation efficiency under ultraviolet excitation, as evidenced by photoluminescence spectra. The photocatalytic studies revealed that the TiO2/ZnO/Au NFs exhibited enhanced photocatalytic efficiency of photodegradation of Methyl orange (MO) and 4-nitrophenol (4-NP) compared with the pure TiO2 nanofibers, ZnO nanofibers and TiO2/ZnO NFs under ultraviolet excitation, which might be attributed to the high separation efficiency of photogenerated electronhole pairs based on the photosynergistic effect among the three components of TiO2, ZnO and Au. And, the TiO2/ZnO/Au NFs could be easily separated and recycled due to their one-dimensional nanostructural property.

  3. Enhanced cycle stability of micro-sized Si/C anode material with low carbon content fabricated via spray drying and in situ carbonization

    Wang, Dingsheng; Gao, Mingxia, E-mail: gaomx@zju.edu.cn; Pan, Hongge; Liu, Yongfeng; Wang, Junhua; Li, Shouquan; Ge, Hongwei

    2014-08-01

    Highlights: • Micro-sized Si/C composites were fabricated via. spray drying and carbonization. • Multi-morphology carbon was formed in the Si/C composites. • Si/C composite with 5.6 wt.% C provides significant improved cycling stability. • Multi-morphology carbon plays effective role in improving the electrochemical property. • The method provides potential for mass production of superior Si-based anode materials. - Abstract: Micro-sized Si/C composites with in situ introduced carbon of multi-morphology were fabricated via spray drying a suspension of commercial micro-sized Si and citric acid followed by a carbonization. Different ratios of Si to citric acid were used to optimize the composition and structure of the composites and thus the electrochemical performance. Carbon flakes including crooked and flat ones were well dispersed in between the Si particles, forming Si/C composites. Floc-like carbon layers and carbon fragments were also found to cover partially the Si particles. The Si/C composite with a low carbon content of 5.6 wt.% provides an initial reversible capacity of 2700 mA h/g and a capacity of 1860 mA h/g after 60 cycles at a current density of 100 mA/g as anode material for lithium-ion batteries (LIBs), which are much higher than those of pristine Si and the Si/C composites with higher carbon content. The mechanism of the enhancement of electrochemical performance of the micro-sized Si/C composite is discussed. The fabrication method and the structure design of the composites offer valuable potential in developing adaptable Si-based anode materials for industrial applications.

  4. In situ formation of a ZnO/ZnSe nanonail array as a photoelectrode for enhanced photoelectrochemical water oxidation performance.

    Wang, Liyang; Tian, Guohui; Chen, Yajie; Xiao, Yuting; Fu, Honggang

    2016-04-28

    In this study, a ZnO/ZnSe nanonail array was prepared via a two-step sequential hydrothermal synthetic route. In this synthetic process, the ZnO nanorod array was first grown on a fluorine-doped tin oxide (FTO) substrate using a seed-mediated growth approach via the hydrothermal process. Then, the ZnO nanonail array was obtained via in situ growth of ZnSe nano caps onto the ZnO nanorod array via a hydrothermal process in the presence of a Se source. The surface morphology and amount of ZnSe grown on the surface of the ZnO nanorods can be regulated by varying the reaction time and reactant concentration. Compared with pure ZnO nanorods, this unique nanonail array heterostructure exhibits enhanced visible light absorption. The transient photocurrent condition, in combination with steady-state and time-resolved photoluminescence spectroscopy, reveals that the ZnO/ZnSe nanonail array electrode has the highest charge separation rate, highest electron injection efficiency, and highest chemical stability. The photocurrent density of the ZnO/ZnSe nanonail array heterostructure reaches 1.01 mA cm(-2) at an applied potential of 0.1 V (vs. Ag/AgCl), which is much higher than that of the ZnO/ZnSe nanorod array (0.71 mA cm(-2)), the pristine ZnO nanorod array (0.39 mA cm(-2)), and the ZnSe electrode (0.21 mA cm(-2)), indicating its significant visible light driven activities for photoelectrochemical water oxidation. This unique morphology of nail-capped nanorods might be important for providing better insight into the correlation between heterostructure and photoelectrochemical activity. PMID:27091395

  5. Radiologic Findings of Ductal Carcinoma in Situ Arising Within a Juvenile Fibroadenoma: Mammographic, Sonographic and Dynamic Contrast-Enhanced Breast MRI Features

    Juvenile fibroadenoma is an uncommon histologic variant of fibroadenoma that frequently shows a remarkable and rapid growth. The development of a carcinoma within a fibroadenoma, either in situ or invasive, is a rare condition. We encountered a 36-year-old woman with a palpable mass in the right breast. The radiologic findings were indicative of a fibroadenoma in the breast. Sonographic guided biopsy using a 14G core needle revealed the presence of ductal carcinoma in situ (DCIS) within the juvenile fibroadenoma. Focal excision was performed and the patient underwent radiation therapy in the right breast after surgery

  6. Mechanism of Enhanced Electrochemical Oxidation of 2,4-dichlorophenoxyacetic Acid with in situ Microwave Activated Boron-doped Diamond and Platinum Anodes

    Gao, Junxia; Zhao, Guohua; Liu, Meichuan; Li, Dongming

    2009-09-01

    Remarkable enhancement in degradation effect is achieved at in situ activated boron-doped diamond (BDD) and Pt anodes with different extent through electrochemical oxidation (EC) of 2,4-dichlorophenoxyacetic acid (2,4-D) with microwave (MW) radiation in a flow system. Results show that when EC is activated with MW radiation, the complete mineralization time of 2,4-D at the BDD is reduced quickly from 10 to 4 h while Chemical oxygen demand (COD) removal at Pt is increased from 37.7 to 58.3% at 10 h; the initial current efficiency is both improved about 1.5 times while the pseudo-first-order rate constant is increased by 153 and 119% at the BDD and Pt, respectively. To gain insight into the higher efficiency in microwave activated EC, the mechanism has therefore been systematically evaluated from the essence of electrochemical reaction and the accumulated hydroxyl radical concentration. 2,4-Dichlorophenol, catechol, benquinone, and maleic and oxalic acids are the main intermediates on the Pt anode measured by high performance liquid chromatography (HPLC), while the intermediates on the BDD electrode include 2,4-dichlorophenol, hydroquinone, and maleic and oxalic acids. The reaction pathway with microwave radiation is the same as that in a conventional electrochemical oxidation on both electrodes. While less and lower aromatic intermediates produce at the BDD with MW, which suggests the higher ring-open ratio and the faster oxidation of carboxylic acids. With microwave radiation, the ring-open ratio at the BDD is increased to 98.8% from 85.6%; the value at Pt is increased to 67.3% from 35.9%. So microwave radiation can activate the electrochemical oxidation, which leads to the higher efficiency. This promotion is mainly due to the higher accumulated hydroxyl radical concentration and the effects by microwave radiation. All the results prove that the BDD electrode presents much better mineralization performance with MW. To the best of our knowledge, it is the first time the systematic analysis of the mechanism of microwave activated EC has been reported.

  7. IN-SITU AIR INJECTION, SOIL VACUUM EXTRACTION AND ENHANCED BIODEGRADATION: A CASE STUDY IN A JP-4 JET FUEL CONTAMINATED SITE

    The U.S. Environmental Protection Agency (U.S. EPA) and the U.S. Coast Guard (USCG) conducted a joint demonstration of in situ remediation of a JP-4 jet fuel spill at the USCG Support Center in Elizabeth City, North Carolina. The jet fuel was trapped beneath a clay layer that ext...

  8. In-situ spectroscopic ellipsometry of microcrystalline silicon deposited by plasma-enhanced chemical vapor deposition on flexible Fe–Ni alloy substrate for photovoltaic applications

    Crystallinity and material quality of hydrogenated microcrystalline silicon (μc-Si:H) films change during their growth, leading to a complex material structure. In order to identify the composition of those inhomogeneous films, deposited on iron–nickel (Fe–Ni) alloy substrates, in-situ ellipsometric data were taken during the thin film growth at regular time intervals. The analysis of the in-situ data taken at the photon energy range between 2.8 and 4.5 eV allowed us to identify the composition of the thin film surface as it grows. The time evolution of the crystalline and amorphous silicon fractions and the surface roughness shows clearly three important phases of the thin film growth: the initial growth of nanocone shaped crystals, the collision phase of neighboring crystals, and the semi-homogeneous material growth until the end of the deposition. The analysis of in-situ data taken during depositions on three different Fe–Ni alloy substrates with different crystal sizes and surface textures shows significant differences in the crystalline silicon fraction of deposited films. The proposed method provides the means to analyze the growth process on flexible Fe–Ni alloy substrates and to optimize the quality of deposited μc-Si:H films by finding the most suitable Fe–Ni substrates. - Highlights: • Crystallinity of microcrystalline silicon films changes during their deposition. • In-situ ellipsometry is used to characterize inhomogeneous material growth. • Films deposited on Fe–Ni substrates show differences in monocrystalline fraction. • Important phases of the thin film growth were observed

  9. In situ vertical profiles of aerosol extinction, mass, and composition over the southeast United States during SENEX and SEAC4RS: observations of a modest aerosol enhancement aloft

    Wagner, N. L.; Brock, C. A.; Angevine, W. M.; A. Beyersdorf; P. Campuzano-Jost; Day, D; Gouw, J.A. De; Diskin, G. S.; Gordon, T. D.; Graus, M. G.; Holloway, J.S.; Huey, G.; Jimenez, J.L.; Lack, D. A.; Liao, J.

    2015-01-01

    Vertical profiles of submicron aerosol from in situ aircraft-based measurements were used to construct aggregate profiles of chemical, microphysical, and optical properties. These vertical profiles were collected over the southeastern United States (SEUS) during the summer of 2013 as part of two separate field studies: the Southeast Nexus (SENEX) study and the Study of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys (SEAC4RS). Shallow ...

  10. An innovative bioelectrochemical-anaerobic digestion-coupled system for in-situ ammonia recovery and biogas enhancement: process performance and microbial ecology

    Zhang, Yifeng; Angelidaki, Irini

    2014-01-01

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production. In batch experiment, the ammonia c...

  11. In-situ spectroscopic ellipsometry of microcrystalline silicon deposited by plasma-enhanced chemical vapor deposition on flexible Fe–Ni alloy substrate for photovoltaic applications

    Mrázková, Z. [LPICM–CNRS, Ecole Polytechnique, 91128 Palaiseau (France); Nanotechnology Centre and Department of Physics, Technical University of Ostrava, 708 33 Ostrava-Poruba (Czech Republic); Torres-Rios, A. [LPICM–CNRS, Ecole Polytechnique, 91128 Palaiseau (France); Ruggeri, R. [LPICM–CNRS, Ecole Polytechnique, 91128 Palaiseau (France); IMM-CNR, Strada VIII n°5 Zona Industriale, 95121 Catania (Italy); Foldyna, M., E-mail: martin.foldyna@polytechnique.edu [LPICM–CNRS, Ecole Polytechnique, 91128 Palaiseau (France); Postava, K.; Pištora, J. [Nanotechnology Centre and Department of Physics, Technical University of Ostrava, 708 33 Ostrava-Poruba (Czech Republic); Roca i Cabarrocas, P. [LPICM–CNRS, Ecole Polytechnique, 91128 Palaiseau (France)

    2014-11-28

    Crystallinity and material quality of hydrogenated microcrystalline silicon (μc-Si:H) films change during their growth, leading to a complex material structure. In order to identify the composition of those inhomogeneous films, deposited on iron–nickel (Fe–Ni) alloy substrates, in-situ ellipsometric data were taken during the thin film growth at regular time intervals. The analysis of the in-situ data taken at the photon energy range between 2.8 and 4.5 eV allowed us to identify the composition of the thin film surface as it grows. The time evolution of the crystalline and amorphous silicon fractions and the surface roughness shows clearly three important phases of the thin film growth: the initial growth of nanocone shaped crystals, the collision phase of neighboring crystals, and the semi-homogeneous material growth until the end of the deposition. The analysis of in-situ data taken during depositions on three different Fe–Ni alloy substrates with different crystal sizes and surface textures shows significant differences in the crystalline silicon fraction of deposited films. The proposed method provides the means to analyze the growth process on flexible Fe–Ni alloy substrates and to optimize the quality of deposited μc-Si:H films by finding the most suitable Fe–Ni substrates. - Highlights: • Crystallinity of microcrystalline silicon films changes during their deposition. • In-situ ellipsometry is used to characterize inhomogeneous material growth. • Films deposited on Fe–Ni substrates show differences in monocrystalline fraction. • Important phases of the thin film growth were observed.

  12. Ad-hoc surface-enhanced Raman spectroscopy methodologies for the detection of artist dyestuffs: thin layer chromatography-surface enhanced Raman spectroscopy and in situ on the fiber analysis.

    Brosseau, Christa L; Gambardella, Alessa; Casadio, Francesca; Grzywacz, Cecily M; Wouters, Jan; Van Duyne, Richard P

    2009-04-15

    Tailored ad-hoc methods must be developed for successful identification of minute amounts of natural dyes on works of art using Surface-Enhanced Raman Spectroscopy (SERS). This article details two of these successful approaches using silver film over nanosphere (AgFON) substrates and silica gel coupled with citrate-reduced Ag colloids. The latter substrate functions as the test system for the coupling of thin-layer chromatography and SERS (TLC-SERS), which has been used in the current research to separate and characterize a mixture of several artists' dyes. The poor limit of detection of TLC is overcome by coupling with SERS, and dyes which co-elute to nearly the same spot can be distinguished from each other. In addition, in situ extractionless non-hydrolysis SERS was used to analyze dyed reference fibers, as well as historical textile fibers. Colorants such as alizarin, purpurin, carminic acid, lac dye, crocin, and Cape jasmine were thus successfully identified. PMID:19317457

  13. In-situ remediation strategy for enhanced microbial de-acidification of geogenic sulphuric acid mining lakes - mesocosmic studies; In situ-Sanierungsstrategie zur Foerderung der mikrobiellen Entsaeuerung von geogen schwefelsauren Bergbaurestseen - Mesokosmosstudien

    Froemmichen, R.

    2001-07-01

    The author investigated whether neutralisation of acid mining lakes can be enhanced by adding low-cost, complex organic carbon sources. Subjects: Selection of a complex carbon source suited for stimulation of dissimilatory iron and sulfate reduction; design and observation of a near-natural landscape compartment (mesocosmos) at different scales as a preparation for the field study; Description of reactions in the mesocosmic lake water and sediment; Assessment of neutralisation equivalents and neutralisation rates on the basis of an identification of reduced iron and sulphur compounds. [German] Die Hypothese, dass durch Zugabe kostenguenstiger komplexer organischer Kohlenstoffquellen in die sedimentnahe Wasserzone eines sauren Tagebaurestsees seeinterne Neutralisierungsprozesse gefoerdert werden, liegt dieser Arbeit zu Grunde. Seeinterne Neutralisationsprozesse, wie die dissimilatorische Eisen- und Sulfatreduktion, fuehren ueber die Akkumulierung von reduzierten Eisen- und Schwefelverbindungen im Sediment zur Alkalinitaetsbildung im Gewaessersystem und im Seewasser zu hoeheren pH-Werten. Daher leiten sich folgende Ziele fuer diese Arbeit ab: - Auswahl einer geeigneten komplexen Kohlenstoffquelle zur Stimulierung der dissimilatorischen Eisen- und Sulfatreduktion - Design und Beobachtung eines naturnahen Landschaftsausschnittes (Mesokosmos) unterschiedlicher Massstabsebenen in Vorbereitung fuer die Fallstudie im Freiland - Beschreibung von Stoffumsetzungen im Seewasser und -sediment der Mesokosmen - Abschaetzung von Neutralisationsaequivalenten und Bestimmung von Neutralisationsraten anhand der Identifizierung reduzierter Eisen- und Schwefelverbindungen. (orig.)

  14. Microwave-antenna induced in situ synthesis of Cu nanowire threaded ZIF-8 with enhanced catalytic activity in H2 production

    Zhang, Dieqing; Liu, Peijue; Xiao, Shuning; Qian, Xufang; Zhang, Hui; Wen, Meicheng; Kuwahara, Yasutaka; Mori, Kohsuke; Li, Hexing; Yamashita, Hiromi

    2016-03-01

    A microwave-antenna strategy was developed for the in situ synthesis of Cu nanowire (CuNW) threaded ZIF-8. The CuNWs acted as microwave-antennas to generate surface ``super hot'' dots. The high temperature of ``super hot'' dots induced adsorption and coordination of metal ions and organic ligands, followed by in situ assembly and crystal-growth along the CuNWs. This catalyst exhibited high activity and stability in H2 production via NH3BH3 hydrolysis owing to the synergetic effect. The CuNWs supplied a rapid electron transfer channel while ZIF-8 assembled on the CuNWs offered a large capacity for adsorbing reactants and channels for rapidly transferring H-/H+ ions toward Cu active sites. Other one-dimensional threaded MOFs, including CuNW threaded MOF-5 and UIO-66, or carbon nanotube threaded ZIF-8 and ZIF-67 could also be prepared using the microwave-antenna strategy.A microwave-antenna strategy was developed for the in situ synthesis of Cu nanowire (CuNW) threaded ZIF-8. The CuNWs acted as microwave-antennas to generate surface ``super hot'' dots. The high temperature of ``super hot'' dots induced adsorption and coordination of metal ions and organic ligands, followed by in situ assembly and crystal-growth along the CuNWs. This catalyst exhibited high activity and stability in H2 production via NH3BH3 hydrolysis owing to the synergetic effect. The CuNWs supplied a rapid electron transfer channel while ZIF-8 assembled on the CuNWs offered a large capacity for adsorbing reactants and channels for rapidly transferring H-/H+ ions toward Cu active sites. Other one-dimensional threaded MOFs, including CuNW threaded MOF-5 and UIO-66, or carbon nanotube threaded ZIF-8 and ZIF-67 could also be prepared using the microwave-antenna strategy. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07505j

  15. Characterisation of vertical BrO distribution during events of enhanced tropospheric BrO in Antarctica, from combined remote and in-situ measurements

    Roscoe, H. K.; Brough, N.; Jones, A E; Wittrock, F.; Richter, A; Van Roozendael, M.; Hendrick, F.

    2014-01-01

    Tropospheric BrO was measured by a ground-based remote-sensing spectrometer at Halley in Antarctica in spring 2007, and BrO was measured by satellite-borne remote-sensing spectrometers using similar spectral regions and similar Differential Optical Absorption Spectroscopy (DOAS) analyses. Near-surface BrO was simultaneously measured in situ at Halley by Chemical Ionisation Mass Spectrometer (CIMS), and in an earlier year near-surface BrO was measured at Halley over a long path by a ground-bas...

  16. Enhanced performance of polymer solar cell with ZnO nanoparticle electron transporting layer passivated by in situ cross-linked three-dimensional polymer network

    An in situ cross-linked three-dimensional polymer network has been developed to passivate ZnO nanoparticles as an electron transporting layer (ETL) to improve the performance of inverted organic solar cells. The passivated ZnO ETL-based devices achieve efficiencies of 3.26% for poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and 7.37% for poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  17. In-Situ Simulation

    Bjerregaard, Anders Thais; Slot, Susanne; Paltved, Charlotte; Musaeus, Peter

    2015-01-01

    Introduction: In situ simulation offers on-site training to healthcare professionals. It refers to a training strategy where simulation technology is integrated into the clinical encounter. Training in the simulation laboratory does not easily tap into situational resources, e.g. individual, team......, and organisational characteristic. Therefore, it might fail to fully mimic real clinical team processes. Though research on in situ simulation in healthcare is in its infancy, literature is abundant on patient safety and team training1. Patient safety reporting systems that identify risks to patients...... can improve patient safety if coupled with training and organisational support. This study explored the use of critical incidents and adverse events reports for in situ simulation and short-term observations were used to create learning objectives and training scenarios. Method: This study used an...

  18. In situ groundwater bioremediation

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  19. Microwave-antenna induced in situ synthesis of Cu nanowire threaded ZIF-8 with enhanced catalytic activity in H2 production.

    Zhang, Dieqing; Liu, Peijue; Xiao, Shuning; Qian, Xufang; Zhang, Hui; Wen, Meicheng; Kuwahara, Yasutaka; Mori, Kohsuke; Li, Hexing; Yamashita, Hiromi

    2016-03-31

    A microwave-antenna strategy was developed for the in situ synthesis of Cu nanowire (CuNW) threaded ZIF-8. The CuNWs acted as microwave-antennas to generate surface "super hot" dots. The high temperature of "super hot" dots induced adsorption and coordination of metal ions and organic ligands, followed by in situ assembly and crystal-growth along the CuNWs. This catalyst exhibited high activity and stability in H2 production via NH3BH3 hydrolysis owing to the synergetic effect. The CuNWs supplied a rapid electron transfer channel while ZIF-8 assembled on the CuNWs offered a large capacity for adsorbing reactants and channels for rapidly transferring H(-)/H(+) ions toward Cu active sites. Other one-dimensional threaded MOFs, including CuNW threaded MOF-5 and UIO-66, or carbon nanotube threaded ZIF-8 and ZIF-67 could also be prepared using the microwave-antenna strategy. PMID:27001205

  20. Enhancement in statistical and image analysis for in situ µSXRF studies of elemental distribution and co-localization, using Dioscorea balcanica

    Dučić, Tanja, E-mail: tanja.ducic@desy.de; Borchert, Manuela [DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Savić, Aleksandar; Kalauzi, Aleksandar; Mitrović, Aleksandra; Radotić, Ksenija, E-mail: tanja.ducic@desy.de [University of Belgrade, Kneza Višeslava 1, 11000 Belgrade (Serbia)

    2013-03-01

    Synchrotron-radiation-based X-ray microfluorescence has been used for in situ investigation of the distribution of micronutrient and macronutrient elements in an unstained cross section of a stem of monocotyledonous liana plant Dioscorea balcanica Košanin. The elemental allocation has been quantified and the grouping/co-localization in straight and twisted stem internodes has been analysed. Synchrotron-based X-ray microfluorescence (µSXRF) is an analytical method suitable for in situ investigation of the distribution of micronutrient and macronutrient elements in several-micrometres-thick unstained biological samples, e.g. single cells and tissues. Elements are mapped and quantified at sub-p.p.m. concentrations. In this study the quantity, distribution and grouping/co-localization of various elements have been identified in straight and twisted internodes of the stems of the monocotyledonous climber D. balcanica Košanin. Three different statistical methods were employed to analyse the macro-nutrient and micronutrient distributions and co-localization. Macronutrient elements (K, P, Ca, Cl) are distributed homogeneously in both straight and twisted internodes. Micronutrient elements are mostly grouped in the vasculature and in the sclerenchyma cell layer. In addition, co-localization of micronutrient elements is much more prominent in twisted than in straight internodes. These image analyses and statistical methods provided very similar outcomes and could be applied to various types of biological samples imaged by µSXRF.

  1. Enhancement in statistical and image analysis for in situ µSXRF studies of elemental distribution and co-localization, using Dioscorea balcanica

    Synchrotron-radiation-based X-ray microfluorescence has been used for in situ investigation of the distribution of micronutrient and macronutrient elements in an unstained cross section of a stem of monocotyledonous liana plant Dioscorea balcanica Košanin. The elemental allocation has been quantified and the grouping/co-localization in straight and twisted stem internodes has been analysed. Synchrotron-based X-ray microfluorescence (µSXRF) is an analytical method suitable for in situ investigation of the distribution of micronutrient and macronutrient elements in several-micrometres-thick unstained biological samples, e.g. single cells and tissues. Elements are mapped and quantified at sub-p.p.m. concentrations. In this study the quantity, distribution and grouping/co-localization of various elements have been identified in straight and twisted internodes of the stems of the monocotyledonous climber D. balcanica Košanin. Three different statistical methods were employed to analyse the macro-nutrient and micronutrient distributions and co-localization. Macronutrient elements (K, P, Ca, Cl) are distributed homogeneously in both straight and twisted internodes. Micronutrient elements are mostly grouped in the vasculature and in the sclerenchyma cell layer. In addition, co-localization of micronutrient elements is much more prominent in twisted than in straight internodes. These image analyses and statistical methods provided very similar outcomes and could be applied to various types of biological samples imaged by µSXRF

  2. In-situ bioremediation via horizontal wells

    This project is designed to demonstrate in situ bioremediation of groundwater and sediment contaminated with chlorinated solvents. Indigenous microorganisms were stimulated to degrade TCE, PCE and their daughter products in situ by addition of nutrients to the contaminated zone. In situ biodegradation is a highly attractive technology for remediation because contaminants are destroyed, not simply moved to another location or immobilized, thus decreasing costs, risks, and time, while increasing efficiency and public and regulatory acceptability. Bioremediation has been found to be among the least costly technologies in applications where it will work (Radian 1989). Subsurface soils and water adjacent to an abandoned process sewer line at the SRS have been found to have elevated levels of TCE (Marine and Bledsoe 1984). This area of subsurface and groundwater contamination is the focus of a current integrated demonstration of new remediation technologies utilizing horizontal wells. Bioremediation has the potential to enhance the performance of in situ air stripping as well as offering stand-alone remediation of this and other contaminated sites (Looney et al. 1991). Horizontal wells could also be used to enhance the recovery of groundwater contaminants for bioreactor conversions from deep or inaccessible areas (e.g., under buildings) and to enhance the distribution of nutrient or microbe additions in an in situ bioremediation

  3. Uranium in situ leaching

    Despite the depressed situation that has affected the uranium industry during the past years, the second Technical Committee Meeting on Uranium In Situ Leaching, organized by the International Atomic Energy Agency and held in Vienna from 5 to 8 October 1992, has attracted a relatively large number of participants. A notable development since the first meeting was that the majority of the contributions came from the actual operators of in situ leaching uranium production. At the present meeting, presentations on operations in the USA were balanced by those of the eastern European and Asian countries. Contributions from Bulgaria, China, Czechoslovakia, Germany (from the operation in the former German Democratic Republic), the Russian Federation and Uzbekistan represent new information not commonly available. In situ leach mining is defined in one of the paper presented as a ''mining method where the ore mineral is preferentially leached from the host rock in place, or in situ, by the use of leach solutions, and the mineral value is recovered. Refs, figs and tabs

  4. In situ preparation of novel pn junction photocatalyst BiOI/(BiO)2CO3 with enhanced visible light photocatalytic activity

    Graphical abstract: Novel pn junction photocatalysts BiOI/(BiO)2CO3 with different contents of BiOI were in situ synthesized by simple etching (BiO)2CO3 precursor with hydroiodic acid (HI). XRD, FE-SEM, HRTEM, FT-IR, EDS and DRS were employed to study the structures, morphologies and optical properties of the as-prepared samples. Under visible light (? > 420 nm), BiOI/(BiO)2CO3 hybrid displayed much higher photocatalytic activity than pure (BiO)2CO3 and BiOI for the degradation of methyl orange (MO). The increased photocatalytic activity of BiOI/(BiO)2CO3 could be attributed to the formation of the pn junction between p-BiOI and n-(BiO)2CO3, which effectively suppresses the recombination of photoinduced electronhole pairs. Moreover, the tests of radical scavengers confirmed that O2?and h+ were the main reactive species for the degradation of MO. Highlights: ? BiOI/(BiO)2CO3 was synthesized using an in situ hydroiodic acid etching way. ? BiOI/(BiO)2CO3 displayed excellent photocatalytic activity under visible light. ? O2? and h+ played the major roles for MO degradation over BiOI/(BiO)2CO3. ? p-BiOI/n-(BiO)2CO3 junction significantly affected MO degradation. - Abstract: Novel pn junction photocatalysts BiOI/(BiO)2CO3 with different contents of BiOI were in situ synthesized by etching (BiO)2CO3 precursor with hydroiodic acid (HI) solution. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrometry (FT-IR), energy-dispersive spectroscopy (EDS) and UVvis diffuse reflectance spectroscopy (DRS) were employed to study the structures, morphologies and optical properties of the as-prepared samples. Under visible light (? > 420 nm), BiOI/(BiO)2CO3 hybrid displayed much higher photocatalytic activity than pure (BiO)2CO3 and BiOI for the degradation of methyl orange (MO). The increased photocatalytic activity of BiOI/(BiO)2CO3 could be attributed to the formation of the pn junction between p-BiOI and n-(BiO)2CO3, which effectively suppresses the recombination of photoinduced electronhole pairs. Moreover, the tests of radical scavengers confirmed that O2? and h+ were the main reactive species for the degradation of MO.

  5. Enhancement of growth and structure properties of YBa2Cu3O7-? thin layers by in situ incorporation of gold nano-clusters

    For most hetero-epitactic growth techniques, structural defects due to the lattice misfit, namely tilts, precipitates or holes, turn out to be limiting factors for the successful fabrication of multilayer systems. A new approach of an in situ growth technique dealing with this problem by incorporation of gold nano-clusters is examined. Therefore, pulsed laser deposition (PLD) of a high-TC YBa2Cu3O7-? (YBCO) layer onto a strontium titanate (STO) template with a temporary interlayer of gold with a well-defined film thickness is investigated. Within this process, the gold interlayer shows nano-clustering behavior. Effects on the properties of structure like crystallographic or surface features of the ablated YBCO layer by variation of the film thickness of the gold and YBCO layers are presented. Moreover, distribution and clustering behavior of the crystallized gold nano-particles as well as the basic superconducting properties of the layer system are analyzed.

  6. In situ deposition of graphene nanosheets on wood surface by one-pot hydrothermal method for enhanced UV-resistant ability

    Wan, Caichao, E-mail: wancaichaojy@163.com; Jiao, Yue, E-mail: yjiao123@126.com; Li, Jian, E-mail: lijiangroup@tom.com

    2015-08-30

    Graphical abstract: - Highlights: • The graphene/wood nanocomposites were fabricated via a mild fast one-pot hydrothermal method. • Graphene nanosheets were in situ deposited on the surface of the wood matrix. • The incorporation of graphene nanosheets results in the improvement in the thermal stability of the graphene/wood. • The graphene/wood exhibits superior UV resistance performance. - Abstract: Graphene nanosheets were successfully in situ deposited on the surface of the wood matrix via a mild fast one-pot hydrothermal method, and the resulting hybrid graphene/wood (GW) were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman spectroscopy, and thermogravimetric analysis (TGA). According to the results, the wood matrix was evenly coated by dense uninterrupted multilayer graphene membrane structure, which was formed by layer-by-layer self-assembly of graphene nanosheets. Meanwhile, the graphene coating also induced significant improvement in the thermal stability of GW in comparison with that of the original wood (OW). Accelerated weathering tests were employed to measure and determine the UV-resistant ability of OW and GW. After about six hundred hours of experiments, the surface color change of GW was much less than that of OW; besides, the Fourier transform infrared spectroscopy (FTIR) analysis also proved the less significant changes in surface chemical compositions of GW. The results both indicated that the graphene coating effectively protected wood surface from UV damage. Therefore, this class of GW composite might be expected to be served as high-performance wooden building material for outdoor or some particular harsh environments like strong UV radiation regions use.

  7. In situ deposition of graphene nanosheets on wood surface by one-pot hydrothermal method for enhanced UV-resistant ability

    Graphical abstract: - Highlights: • The graphene/wood nanocomposites were fabricated via a mild fast one-pot hydrothermal method. • Graphene nanosheets were in situ deposited on the surface of the wood matrix. • The incorporation of graphene nanosheets results in the improvement in the thermal stability of the graphene/wood. • The graphene/wood exhibits superior UV resistance performance. - Abstract: Graphene nanosheets were successfully in situ deposited on the surface of the wood matrix via a mild fast one-pot hydrothermal method, and the resulting hybrid graphene/wood (GW) were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman spectroscopy, and thermogravimetric analysis (TGA). According to the results, the wood matrix was evenly coated by dense uninterrupted multilayer graphene membrane structure, which was formed by layer-by-layer self-assembly of graphene nanosheets. Meanwhile, the graphene coating also induced significant improvement in the thermal stability of GW in comparison with that of the original wood (OW). Accelerated weathering tests were employed to measure and determine the UV-resistant ability of OW and GW. After about six hundred hours of experiments, the surface color change of GW was much less than that of OW; besides, the Fourier transform infrared spectroscopy (FTIR) analysis also proved the less significant changes in surface chemical compositions of GW. The results both indicated that the graphene coating effectively protected wood surface from UV damage. Therefore, this class of GW composite might be expected to be served as high-performance wooden building material for outdoor or some particular harsh environments like strong UV radiation regions use

  8. Two weeks of metformin treatment induces AMPK dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

    Kristensen, Jonas Møller; Treebak, Jonas Thue; Schjerling, Peter; Goodyear, Laurie; Wojtaszewski, Jorgen F P; Wojtaszewski, Jørgen

    2014-01-01

    signaling. Methods: Oral doses of metformin or saline treatment were given muscle-specific kinase α2 dead AMPK mice (KD) and wild type (WT) littermates either once or chronically for 2 weeks. Soleus and Extensor Digitorum Longus (EDL) muscles were used for measurements of glucose transport and Western blot...

  9. Effectiveness of Start to Run, a 6-week training program for novice runners, on increasing health-enhancing physical activity: a controlled study

    Ooms, L; Veenhof, C.; Bakker, D.H. de

    2013-01-01

    Background The use of the organized sports sector as a setting for health-promotion is a relatively new strategy. In the past few years, different countries have been investing resources in the organized sports sector for promoting health-enhancing physical activity. In the Netherlands, National Sports Federations were funded to develop and implement “easily accessible” sporting programs, aimed at the least active population groups. Start to Run, a 6-week training program for novice runners, ...

  10. In situ photo-assisted deposition and photocatalysis of ZnIn2S4/transition metal chalcogenides for enhanced degradation and hydrogen evolution under visible light.

    Lim, Wei Yang; Hong, Minghui; Ho, Ghim Wei

    2015-12-22

    The effective immobilization of a transition chalcogenide co-catalyst via an in situ aqueous photo-assisted deposition technique has shown great accessibility to complex ZnIn2S4 host hierarchical nanostructured materials with homogeneous distribution. The complementary photo-assisted deposition readily deposits finely-dispersed co-catalyst particles and simultaneously generates photocatalytic hydrogen. Another added advantage is that the photo-assisted deposition of the co-catalyst does not compromise the crystal structure or the integrity of the host photocatalyst, hence offering a better alternative to the doping technique. A systematic study of various transition metal chalcogenide co-catalysts and optimization of wt% MoS2, CuS and Ag2S loadings were demonstrated. Among them, the ZnIn2S4/MoS2 composite exhibits exceptional photocatalytic hydrogen production and stability as well as superior MO degradation under visible light irradiation. The present methodology is expected to be extendable to various transition metal oxides/chalcogenides since ionic derivatives exhibit high affinity to a variety of materials under photoirradiation. PMID:26605503

  11. In situ fabrication of Ag3PO4/TiO2 nanotube heterojunctions with enhanced visible-light photocatalytic activity.

    Tong, Zhen Wei; Yang, Dong; Sun, Yuan Yuan; Tian, Yao; Jiang, Zhong Yi

    2015-05-14

    Ag3PO4/TiO2 nanotube (TNT) heterojunctions were fabricated via a facile in situ growth method. Hemispherical Ag3PO4 nanocrystals were uniformly grown on the TNT surface, and their size was confined to 5-10 nm. A joint area was distinctly observed between the Ag3PO4 nanocrystals and TNT, indicating the formation of a Ag3PO4/TNT heterojunction. Compared with pure Ag3PO4, the Ag3PO4/TNT heterojunction possesses more active sites, less bulk defects, more efficient electron-hole separation, as well as better dye adsorption properties, and thus exhibits a significantly elevated photocatalytic activity for Rhodamine B (RhB) degradation. The study of the reactive species demonstrates that the photocatalytic degradation of RhB over the Ag3PO4/TNT heterojunction is primarily driven by both photogenerated h(+) and ?OH radicals. This easily-fabricated Ag3PO4/TNT heterojunction with promising photocatalytic activity may find potential applications in energy and environmental related areas. PMID:25884048

  12. Determination of HER-2 status on FNAC material from breast carcinomas using in situ hybridization with dual chromogen visualization with silver enhancement (dual SISH

    Beraki Elsa

    2010-01-01

    Full Text Available During the last years, HER-2 status kits and protocols for chromogen visualization of hybridization signals have come on the market. The first generation using chromogen visualization used single color probes. The second generation, now emerging on the market, uses dual chromogen visualization. The aim of this study has been to test a new dual color chromogen kit (Ventana INFORM HER2 Dual Colour ISH Roche ® and compare the results with our in-house method(s. The material consisted primarily of cytological material from invasive breast carcinomas in 49 women. Dual SISH was done on all 49 cytological and histological specimens. The histological specimens were treated according to the manufacturer′s recommendations. The procedure was modified in several steps in order to adapt it to the cytological material. Hybridization failed in two cytological specimens. Dual SISH showed concordant results on cytological and histological material as to amplified/not amplified. The included cases had the same HER-2 expression in the invasive and the in situ components on histology. Four IDC showed HER-2 amplification (8.5%. Polysomy was found in two cases. All dual SISH results except for one concurred with the results of the in-house method(s (1/47=2.1%. The dual SISH is suitable for cytological examination of HER-2 status. The protocol must be optimized for cytological material.

  13. The in-situ decontamination of sand and gravel aquifers by chemically enhanced solubilization of multiple-component DNAPLS with surfactant solutions. Topical report

    NONE

    1995-01-01

    Laboratory, numerical simulation, and field studies have been conducted to assess the potential use of micellar-surfactant solutions to solubilize chlorinated solvents contaminating sand and gravel aquifers. Laboratory studies were conducted at the State University of New York at Buffalo (SUNY) while numerical simulation and field work were undertaken by INTERA Inc. in collaboration with Martin Marietta Energy Systems Inc. at the Paducah Gaseous Diffusion Plant (PGDP) in Kentucky. Ninety-nine surfactants were screened for their ability to solubilize trichloroethene (TCE), perchloroethylene (PCE), and carbon tetrachloride (CTET). Ten of these were capable of solubilizing TCE to concentrations greater than 15,000 mg/L, compared to its aqueous solubility of 1,100 mg/L. Four surfactants were identified as good solubilizers of all three chlorinated solvents. Of these, a secondary alcohol ethoxylate was the first choice for in situ testing because of its excellent solubilizing ability and its low propensity to sorb. However, this surfactant did not meet the Commonwealth of Kentucky`s acceptance criteria. Consequently, it was decided to use a surfactant approved for use by the Food and Drug Administration as a food-grade additive. As a 1% micellar-surfactant solution, this sorbitan monooleate has a solubilization capacity of 16,000 mg TCE/L, but has a higher propensity to sorb to clays than has the alcohol ethoxylate.

  14. In situ loading of Ag2WO4 on ultrathin g-C3N4 nanosheets with highly enhanced photocatalytic performance.

    Li, Yunfeng; Jin, Renxi; Fang, Xu; Yang, Yang; Yang, Man; Liu, Xianchun; Xing, Yan; Song, Shuyan

    2016-08-01

    The g-C3N4 nanosheets (g-C3N4NS) exhibit more excellent property than common bulk g-C3N4 (g-C3N4-B) due to their large surface areas, improved electron transport ability and well dispersion in water. In this work, ultrathin g-C3N4NS with a thickness of about 2.7nm have been synthesized by a simple thermal exfoliation of bulk g-C3N4, and then Ag2WO4 nanoparticles are in situ loaded on their surface to construct the Ag2WO4/g-C3N4NS heterostructured photocatalysts. Due to their unique physicochemical properties, the as-prepared heterostructures possess a fast interfacial charge transfer and increased lifetime of photo-excited charge carriers, and exhibit much higher photocatalytic activity. Under visible light irradiation, the optimum photocatalytic activity of Ag2WO4/g-C3N4NS composites is almost 53.6 and 26.5 times higher than that of pure g-C3N4-B and Ag2WO4/g-C3N4-B heterostructures towards the degradation of rhodamine B, respectively, and is almost 30.6 and 9.8 times higher towards the degradation of methyl orange, respectively. In addition, the natural sunlight photocatalytic activities of the as-prepared samples are also investigated. PMID:27107322

  15. In Situ Mass Spectrometer Project

    National Aeronautics and Space Administration — The In Situ Mass Spectrometer projects focuses on a specific subsystem to leverage advanced research for laser-based in situ mass spectrometer development...

  16. Time-resolved in situ detection of CO in a shock tube using cavity-enhanced absorption spectroscopy with a quantum-cascade laser near 4.6 m.

    Sun, Kai; Wang, Shengkai; Sur, Ritobrata; Chao, Xing; Jeffries, Jay B; Hanson, Ronald K

    2014-10-01

    Cavity-enhanced absorption spectroscopy (CEAS) using a mid-infrared DFB quantum-cascade laser is reported for sensitive time-resolved (10 ?s) in situ CO measurements in a shock tube. Off-axis alignment and fast scanning of the laser wavelength were used to minimize coupling noise in a low-finesse cavity. An absorption gain factor of 91 was demonstrated, which enabled sub-ppm detection sensitivity for gas temperatures of 1000-2100K in a 15 cm diameter shock tube. This substantial improvement in detection sensitivity compared to conventional single-pass absorption measurements, shows great potential for the study of reaction pathways of high-temperature combustion kinetics mechanisms in shock tubes. PMID:25322031

  17. LEAKING UNDERGROUND STORAGE TANKS: REMEDIATION WITH EMPHASIS ON 'IN SITU' BIORESTORATION

    The current literature indicates that in situ biorestoration has great potential for remediation of aquifers contaminated by leaking underground storage tanks. In situ aquifer restoration involves the enhancement of the indigenous microflora to degrade subsurface pollutants. The ...

  18. LEAKING UNDERGROUND STORAGE TANKS: REMEDIATION WITH EMPHASIS ON IN SITU BIORESTORATION

    The current literature indicates that in situ biorestoration has great potential for remediation of aquifers contaminated by leaking underground storage tanks. In situ aquifer restoration involves the enhancement of the indigenous microflora to degrade subsurface pollutants. The ...

  19. Efficacy monitoring of in situ fuel bioremediation

    The wide-scale, multiple-purpose use of fossil fuels throughout the industrialized world has resulted in the inadvertent contamination of myriad environments. Given the scope and magnitude of these environmental contamination problems, bioremediation often represents the only practical and economically feasible solution. This is especially true when depth of contamination, magnitude of the problem, and nature of contaminated material preclude other remedial actions, short of the no-response alternative. From the perspective, the effective, safe and scientifically valid use of in situ bioremediation technologies requires cost-efficient and effective implementation strategies in combination with unequivocal approaches for monitoring efficacy of performance. Accordingly, with support from the SERDP program, the authors are field-testing advanced in situ bioremediation strategies and new approaches in efficacy monitoring that employ techniques instable carbon and nitrogen isotope biogeochemistry. One field demonstration has been initiated at the NEX site in Port Hueneme, CA (US Navy's National Test Site). The objectives are: (1) to use stable isotopes as a biogeochemical monitoring tool for in situ bioremediation of refined petroleum (i.e., BTEX), and (2) to use vertical groundwater circulation technology to effect in situ chemical containment and enhanced in situ bioremediation

  20. Ductal carcinoma in situ.

    Bleicher, Richard J

    2013-04-01

    Management of ductal carcinoma in situ (DCIS) has evolved from radical surgery to the option of a more minimally invasive approach. Data show that breast conservation surgery performed with administration of radiotherapy, like mastectomy, is feasible and safe. Because efforts to find a safe group for elimination of radiotherapy have resulted in data that conflict, radiotherapy still remains standard of care as a part of breast conservation for DCIS. Tamoxifen has also shown a significant recurrence benefit and has become standard in the treatment of receptor-positive disease. Investigation of other agents, such as anastrazole and trastuzumab, are ongoing. PMID:23464692

  1. Two weeks of metformin treatment enhances mitochondrial respiration in skeletal muscle of AMPK kinase dead but not wild type mice

    Kristensen, Jonas Møller; Larsen, Steen; Helge, Jørn Wulff; Dela, Flemming; Wojtaszewski, Jørgen

    2013-01-01

    associated with stimulation of mitochondrial function and biogenesis. However, a causal relationship in skeletal muscle has not been investigated. We hypothesized that potential effects of in vivo metformin treatment on mitochondrial function and protein expressions in skeletal muscle are dependent upon AMPK......Metformin is used as an anti-diabetic drug. Metformin ameliorates insulin resistance by improving insulin sensitivity in liver and skeletal muscle. Reduced mitochondrial content has been reported in type 2 diabetic muscles and it may contribute to decreased insulin sensitivity characteristic for...... signaling. We investigated this by two weeks of oral metformin treatment of muscle specific kinase dead a(2) (KD) AMPK mice and wild type (WT) littermates. We measured mitochondrial respiration and protein activity and expressions of key enzymes involved in mitochondrial carbohydrate and fat metabolism and...

  2. Continuous delta 1-hydrocortisone dehydrogenation with in situ product recovery.

    Silbiger, E; Freeman, A

    1991-11-01

    A continuous aerated process for delta 1-hydrocortisone dehydrogenation by polyacrylamide-hydrazide (PAAH) bead-entrapped A. simplex cells was developed. The process allows for stable conversion of 1.6 g l-1 hydrocortisone (x 5 the solubility in water), made possible by the incorporation of selected cosolvent [5% (v/v) triethyleneglycol]. A large difference in substrate and product solubilities in the cosolvent-buffer medium allowed for in situ product recovery in an aerated, fluidized-bed, immobilized-cell reactor by the controlled addition of fine product-adsorbing powder (microcrystalline cellulose). The product was recovered at the reactor outlet as a fine complex with the adsorbent. Stable continuous operation of at least 4 weeks was recorded for a prototype reactor configuration, followed by the exhibition of similar operational stability in a modified version of a commercially available 2.5-l airlift reactor. Our results demonstrate that in addition to an obvious desirable cosolvent effect on substrate solubility enhancement, it may also enable easy in situ product recovery by creating a large gap in the solubilities of the substrate and the product in the cosolvent-containing reaction medium. PMID:1367997

  3. Solvothermal in situ synthesis of Fe3O4-multi-walled carbon nanotubes with enhanced heterogeneous Fenton-like activity

    Graphical abstract: After purification, the multi-wall carbon nanotubes (MWCNTs) act as seeds for Fe3O4 nanoparticles heterogeneous nucleation. The Fe3O4 nanoparticles with diameter range of 4.2–10.0 nm synthesized in situ on the MWCNTs under solvothermal condition. The formed nano Fe3O4-MWCNTs decolorized the Acid Orange II effectively via Fenton-like reaction. Highlights: ► The amount of water tunes size and size distribution of the Fe3O4 nanoparticles (FNs). ► FNs are homogeneously coated on the multi-walled carbon nanotubes (MWCNTs). ► FNs have diameters in the range of 4.2–10.0 nm, average grain size of 7.4 nm. ► Fe3O4-MWCNTs are used as a Fenton-like catalyst to decompose Acid Orange II. ► Fe3O4-MWCNTs displayed a higher activity than nanometer-size Fe3O4. -- Abstract: Fe3O4-multi-walled carbon nanotubes (Fe3O4-MWCNTs) hybrid materials were synthesized by a solvothermal process using acid treated MWCNTs and iron acetylacetonate in a mixed solution of ethylene glycol and ultrapure water. The materials were characterized using X-ray powder diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometry. The results showed that a small amount of water in the synthesis system played a role in controlling crystal phase formation, size of Fe3O4, and the homogeneous distribution of the Fe3O4 nanoparticles deposited on the MWCNTs. The Fe3O4 nanoparticles had diameters in the range of 4.2–10.0 nm. They displayed good superparamagnetism at room temperature and their magnetization was influenced by the reaction conditions. They were used as a Fenton-like catalyst to decompose Acid Orange II and displayed a higher activity than nanometer-size Fe3O4.

  4. Significant plasticity enhancement of ZrCu-based bulk metallic glass composite dispersed by in situ and ex situ Ta particles

    Graphical abstract: Confinement zone of Ta particles provide a plastic shielding to obstruct shear banding and so as to significantly increase the plasticity of Zr-based BMGC. Evidence of remarkable plasticity improvement of Zr-based BMGC dispersed by the combination of in situ and ex situ Ta particles can be seen from the stress–strain curve (a) as well as the fractured samples of monolithic BMG ((b): brittle fracture) and BMGC ((c): severe plastic deformation). Highlights: ► Shear bands are arrested by the interface of glassy matrix/Ta in the Zr-based BMGCs. ► Ta particles of BMGC distributed as a semi-uniform confinement zone. ► Confinement zone exhibits smaller size than plastic zone of crack-tip in the BMGC. ► Confinement zone of Ta provide a plastic shielding to obstruct shear banding. ► Plasticity can be improved from 0% (monolithic BMG) to 44% plastic strain (BMGC). - Abstract: Using two-step arc melting process and suction casting, the Zr47.3Cu32Al8Ag8Ta4Si0.7-based bulk metallic glass composites (BMGCs) rods with ex situ added micro-sized Ta particles have been successfully fabricated. The structure and thermal properties of these BMGCs samples were examined by differential scanning calorimeter (DSC) and X-ray diffraction (XRD). It was found that these BMGCs with ex situ added Ta exhibit similar thermal properties in comparison with their base alloy counterpart, with relatively high glass forming ability (GFA). For the mechanical study, the results of compression test show that more than 25% compressive plastic strain and 1800 MPa fracture strength at room temperature can be obtained for the 2 mm diameter rod of the ZrCu-based BMGC ex situ added 6 and 9 vol.% Ta particles, respectively. Images from SEM on the fractured surfaces show that the homogeneously distributed Ta particles (20 ± 8 μm) would form semi-uniform confinement zones to restrict the shear band propagation. In other words, the inter-particle free space and the size of confinement zone (mean free path of shear bands) is apparently the controlling factor in affecting the plasticity of BMGCs.

  5. Effectiveness of weekly cognitive stimulation therapy for people with dementia and the additional impact of enhancing cognitive stimulation therapy with a carer training program

    Cove J

    2014-12-01

    Full Text Available Jennifer Cove,1 Nicola Jacobi,2 Helen Donovan,3 Martin Orrell,4 Josh Stott,5 Aimee Spector5 1Department of Clinical, Educational and Health Psychology, University College London, London, 2Department of Psychology, City University, London, 3Clinical Psychology Service, South Essex Partnership NHS Foundation Trust, Bedford, 4Department of Psychiatry, 5Department of Clinical,Educational and Health Psychology, University College London, London, UKPurpose of the study: Cognitive stimulation therapy (CST is a widely used, evidence-based intervention for people with dementia (PwD. Although designed as a 14 session, twice weekly intervention, many services in the UK deliver CST once a week for 14 weeks. However, this method of delivery has yet to be evaluated. In addition, CST does not include any formal carer training. This study aimed to evaluate the effectiveness of once weekly CST and determine any additional impact when enhanced with a carer training program.Design and methods: A single blind, randomized controlled trial was conducted. Sixty eight PwD and their carers were recruited through three community Memory Assessment Services. PwD and their carers were randomized to one of three conditions: CST plus carer training, CST only, or a wait list control. PwD were administered standardized measures of cognition, quality of life, and quality of relationship with carer at baseline and the 15 week follow-up.Results: There were no baseline differences across the three groups. At follow-up, there were no significant differences between PwD in the three groups on any outcomes. Implications: Weekly CST with or without carer training may not be an effective form of delivery. Several possible explanations for the outcomes are proposed. Weekly CST may not offer the necessary dose required to combat decline, and equally the carer training may have been too brief to have made a difference. Services currently offering weekly CST should collect routine outcome data to support its use and provide practice-based evidence.Keywords: Alzheimers disease, cognition, intervention, caregiver

  6. A NEW METHOD FOR IN-SITU CHARACTERIZATION OF IMPORTANT ACTINIDES AND TECHNETIUM COMPOUNDS VIA FIBEROPTIC SURFACE ENHANCED RAMAN SPECTROSCOPY (SERS)

    This project serves to fill information gap through the development of a novel surface-enhanced Raman scattering (SERS) spectroscopy to selectively and sensitively monitor and characterize the chemical speciation of radionuclides at trace levels. The SERS technique permits both o...

  7. FIELD TEST OF CYCLODEXTRIN FOR ENHANCED IN-SITU FLUSHING OF MULTIPLE-COMPONENT IMMISCIBLE ORGANIC LIQUID CONTAMINATION: COMPARISON TO WATER FLUSHING

    A pilot-scale field experiment was conducted to compare the remediation effectiveness of an enhanced-solubilization technique to that of water flushing for removal of multicomponent nonaqueous-phase organic liquid (NAPL) contaminants form a phreatic aquifer. This innovative remed...

  8. Facile in situ synthesis of 2D porous g-C3N4 and g-C3N4/P25(N) heterojunction with enhanced quantum effect for efficient photocatalytic application

    Highlights: • N doped P25 is efficient in synthesizing g-C3N4 with enhanced quantum effect. • The few-layered g-C3N4 has a two-dimensional and porous structure. • The few-layered g-C3N4 is superior to the bulk g-C3N4 for photocatalysis. • Efficient heterojunction is in situ formed between g-C3N4 and N doped P25. • The mass ratio of g-C3N4 to N doped P25 affects the photocatalytic activity. - Abstract: The major challenge of employing photocatalysis for environment protection is to develop high efficient, low cost, and stable semiconductor photocatalysts. In the present study, an in situ annealing strategy is employed for large scale synthesis of two-dimensional (2D) porous graphitic carbon nitride (g-C3N4) and efficient g-C3N4/P25(N) (N doped P25) heterojunction with enhanced quantum effect. The P25 not only serves as the template for g-C3N4 polymerization, but is also modified by the N species to enhance the visible light absorption. Compared to the normal bulk g-C3N4, the 2D porous g-C3N4 with enhanced quantum effect is found to be more efficient in improving the specific surface area and the electron–hole pair’s separation, even its light absorption edge is blue-shifted. Photocatalytic degradation of Rhodamine B (RhB) and phenol indicates the 2D g-C3N4 and g-C3N4/P25(N) are very efficient and stable under the xenon lamp irradiation. It is also found that the original mass ratio of urea, which is the precursor for g-C3N4 synthesis and P25 modification, to P25 also plays a significant effect on the photocatalytic activity. The optimized photocatalyst (mass ratio of P25 to urea is 1:8) can decompose total RhB aqueous solution (10 mg/L, 100 ml) in 25 min. Based on systematic characterizations and discussions, a possible photocatalytic mechanism for the excellent photocatalytic performance is proposed

  9. Facile in situ synthesis of 2D porous g-C{sub 3}N{sub 4} and g-C{sub 3}N{sub 4}/P25(N) heterojunction with enhanced quantum effect for efficient photocatalytic application

    Ding, Mingye [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Wang, Wei, E-mail: wwnjut@hotmail.com [School of Physics and Optoelectronic Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Zhou, Yingjie [School of Physics and Optoelectronic Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Lu, Chunhua; Ni, Yaru; Xu, Zhongzi [College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009 (China)

    2015-06-25

    Highlights: • N doped P25 is efficient in synthesizing g-C{sub 3}N{sub 4} with enhanced quantum effect. • The few-layered g-C{sub 3}N{sub 4} has a two-dimensional and porous structure. • The few-layered g-C{sub 3}N{sub 4} is superior to the bulk g-C{sub 3}N{sub 4} for photocatalysis. • Efficient heterojunction is in situ formed between g-C{sub 3}N{sub 4} and N doped P25. • The mass ratio of g-C{sub 3}N{sub 4} to N doped P25 affects the photocatalytic activity. - Abstract: The major challenge of employing photocatalysis for environment protection is to develop high efficient, low cost, and stable semiconductor photocatalysts. In the present study, an in situ annealing strategy is employed for large scale synthesis of two-dimensional (2D) porous graphitic carbon nitride (g-C{sub 3}N{sub 4}) and efficient g-C{sub 3}N{sub 4}/P25(N) (N doped P25) heterojunction with enhanced quantum effect. The P25 not only serves as the template for g-C{sub 3}N{sub 4} polymerization, but is also modified by the N species to enhance the visible light absorption. Compared to the normal bulk g-C{sub 3}N{sub 4}, the 2D porous g-C{sub 3}N{sub 4} with enhanced quantum effect is found to be more efficient in improving the specific surface area and the electron–hole pair’s separation, even its light absorption edge is blue-shifted. Photocatalytic degradation of Rhodamine B (RhB) and phenol indicates the 2D g-C{sub 3}N{sub 4} and g-C{sub 3}N{sub 4}/P25(N) are very efficient and stable under the xenon lamp irradiation. It is also found that the original mass ratio of urea, which is the precursor for g-C{sub 3}N{sub 4} synthesis and P25 modification, to P25 also plays a significant effect on the photocatalytic activity. The optimized photocatalyst (mass ratio of P25 to urea is 1:8) can decompose total RhB aqueous solution (10 mg/L, 100 ml) in 25 min. Based on systematic characterizations and discussions, a possible photocatalytic mechanism for the excellent photocatalytic performance is proposed.

  10. An enhanced postnatal autoimmune profile in 24 week-old C57BL/6 mice developmentally exposed to TCDD

    Developmental exposure of mice to the environmental contaminant and AhR agonist, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), causes persistent postnatal suppression of T cell-mediated immune responses. The extent to which prenatal TCDD may induce or exacerbate postnatal autoimmune disease remains unknown. In the present study, time-pregnant high affinity AhR C57BL/6 mice received a single oral administration of 0, 2.5, or 5 μg/kg TCDD on gestation day (gd) 12. Offspring of these mice (n = 5/gender/treatment) were evaluated at 24 weeks-of-age and showed considerable immune dysregulation that was often gender-specific. Decreased thymic weight and percentages of CD4+CD8+ thymocytes, and increased CD4+CD8- thymocytes, were present in the female but not male offspring. Males but not females showed decreased CD4-CD8+ T cells, and increased Vβ3+ and Vβ17a+ T cells, in the spleen. Males but not females also showed increased percentages of bone marrow CD24-B220+ B cell progenitors. Antibody titers to dsDNA, ssDNA and cardiolipin displayed increasing trends in both male and female mice, reaching significance for anti-dsDNA in both genders and for ssDNA in males at 5 μg/kg TCDD. Immunofluorescent staining of IgG and C3 deposition in kidney glomeruli increased in both genders of prenatal TCDD-exposed mice, suggestive of early stages of autoimmune glomerulonephritis. Collectively, these results show that exposure to TCDD during immune system development causes persistent humoral immune dysregulation as well as altered cell-mediated responses, and induces an adult profile of changes suggestive of increased risk for autoimmune disease

  11. BCG for carcinoma in situ.

    Jakse, G

    1992-01-01

    Bacillus Calmette-Guérin (BCG) is the most effective intravesical therapy of carcinoma in situ of the urinary bladder. Six, weekly instillations of BCG result in a complete remission in about 70-80% of patients. The optimal dose however has still to be defined, and the value of maintenance therapy is also a matter of debate. Recurrent tumours after complete remission occur mainly in the distal ureter and prostatic urethra. In these patients, cystectomy may be required. In about 60-80% of patients, local (e.g. cystitis) and/or systemic (e.g. fever, malaise) side effects are observed. The occurrence of cystitis is associated with the number of instillations, BCG dose and a positive skin test. Systemic side effects are connected with pre-existing dysuria or bacterial cystitis and with traumatic catheterization. Severe toxicity occurs in about 5% of the patients. Prognostic parameters indicating complete remission have yet to be determined, but there is evidence that cytokines detected in the urine and immune-cell infiltration into the bladder wall revealed by immunohistochemistry, can be of value in this respect. PMID:1396945

  12. An innovative bioelectrochemical-anaerobic digestion-coupled system for in-situ ammonia recovery and biogas enhancement: process performance and microbial ecology

    Zhang, Yifeng; Angelidaki, Irini

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell...... performance was enhanced. In addition, the coexistence of other cations in CSTR or cathode had no negative effect on the ammonia transportation. In continuous reactor operation, 112% extra biogas production was achieved due to ammonia recovery. High-throughput molecular sequencing analysis showed an impact of...

  13. Melatonin enhances interleukin-10 expression and suppresses chemotaxis to inhibit inflammation in situ and reduce the severity of experimental autoimmune encephalomyelitis.

    Chen, Shyi-Jou; Huang, Shing-Hwa; Chen, Jing-Wun; Wang, Kai-Chen; Yang, Yung-Rong; Liu, Pi-Fang; Lin, Gu-Jiun; Sytwu, Huey-Kang

    2016-02-01

    Melatonin is the major product secreted by the pineal gland at night and displays multifunctional properties, including immunomodulatory functions. In this study, we investigated the therapeutic effect of melatonin in experimental autoimmune encephalomyelitis (EAE). We demonstrated that melatonin exhibits a therapeutic role by ameliorating the clinical severity and restricting the infiltration of inflammatory Th17 cells into the CNS of mice with myelin oligodendrocyte glycoprotein (MOG)-induced EAE. Furthermore, melatonin enhances splenic interleukin (IL)-10 expression in regulatory T cells by inducing IL-27 expression in the splenic DC; it also suppresses the expression of IFN-γ, IL-17, IL-6, and CCL20 in the CNS and inhibits antigen-specific T cell proliferation. However, there were no significant differences in the percentage of splenic regulatory T cells. These data provide the first evidence that the therapeutic administration of melatonin is effective in mice with EAE and modulates adaptive immunity centrally and peripherally. Thus, we suggest that melatonin could play an adjunct therapeutic role in treating human CNS autoimmune diseases such as multiple sclerosis. Melatonin merits further studies in animals and humans. PMID:26735612

  14. Cadmium oxide nanoparticles grown in situ on reduced graphene oxide for enhanced photocatalytic degradation of methylene blue dye under ultraviolet irradiation.

    Kumar, Sumeet; Ojha, Animesh K; Walkenfort, Bernd

    2016-06-01

    Cadmium oxide (CdO) nanoparticles (NPs), reduced graphene oxide (rGO) and rGO-CdO nanocomposites have been synthesized using one step hydrothermal method. The structural and optical properties of CdO NPs, rGO, and rGO-CdO nanocomposites were investigated by X-ray diffraction (XRD), energy dispersive X-ray (EDX), high resolution transmission electron microscopy (HR-TEM), Raman spectroscopy (RS), ultraviolet-visible spectroscopy (UV-Vis.) and photoluminescence (PL) spectroscopy techniques. The rGO has a sharp 2D peak compared to GO. The sharp nature of 2D band may be due to the larger contribution from single layer sheet. The photocatalytic activity of the synthesized samples has been investigated under UV irradiation. The results of photocatalytic measurements revealed that ~80% of MB dye is degraded by adding the rGO-CdO nanocomposites as photocatalysts into the dye solution. The decrease in the intensity of emission peaks indicates that the photogenerated charge carriers have been transferred from CdO NPs to rGO sheets, which causes to increase the density of O2(-) and OH radicals in the dye solution. The CdO nanoparticles gown on the rGO sheets showed enhanced ferromagnetism (FM) at room temperature, which may be attributed to the short range magnetic interaction of magnetic moments of CdO NPs and spin units present on the rGO sheets. PMID:27045279

  15. In Situ Fabrication of Bi2Ti2O7/TiO2 Heterostructure Submicron Fibers for Enhanced Photocatalytic Activity.

    Zhou, Di; Yang, Hu; Tu, Yafang; Tian, Yu; Cai, Yaxuan; Hu, Zhenglong; Zhu, Xiaolong

    2016-12-01

    A facile two-step synthesis route combining electrospinning and hydrothermal techniques has been performed to obtain Bi2Ti2O7/TiO2 heterostructured submicron fibers. Bi2Ti2O7 nanosheets were grown on the surface of TiO2 submicron fibers. The density of the nanosheets increased with higher precursor concentration of the Bi/Ti reaction raw materials. UV-visible (UV-vis) diffuse reflectance spectroscopy indicated that the absorption spectrum of the Bi2Ti2O7/TiO2 composite extended into the visible-light region. Photocatalytic tests showed that the Bi2Ti2O7/TiO2 heterostructures possess a much higher degradation rate of rhodamine B than the unmodified TiO2 submicron fibers under visible light. The enhanced photocatalytic activity can be attributed to the synergistic effect between improved visible-light absorption and the internal electric field created by the heterojunctions. The effective separation of photogenerated carriers driven by the photoinduced potential was demonstrated by the photoelectrochemical analysis. PMID:27071680

  16. Green synthesis of Pt-on-Pd bimetallic nanodendrites on graphene via in situ reduction, and their enhanced electrocatalytic activity for methanol oxidation

    Graphical abstract: - Highlights: • Porous 3D dendrite-like structure of Pt-on-Pd bimetallic nanostructures supported on graphene were prepared. • The surface of nanostructures was very “clean” because of the surfactant-free formation process and the use of green reagent. • The hetero-nanostructures showed excellent electrocatalytic performance in methanol oxidation. - Abstract: A green synthesis of Pt-on-Pd bimetallic nanodendrites supported on graphene (GPtPdNDs) with a Pd interior and a dendrite-like Pt exterior was achieved using a two-step preparation, mixing graphene and PdCl42− first, then adding PtCl42− and ethanol without any other solvent. The morphology, structure and composition of the thus-prepared GPtPdNDs were characterized by transmission electron microscopy (TEM), high resolution TEM, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Because no halide ions (refer in particular to Br-, I−) or surfactant was involved in the synthesis, the prepared GPtPdNDs were directly modified onto a glassy carbon electrode and showed excellent electrocatalytic performance in methanol oxidation without any pretreatments. Moreover, with the special structure of PtPdNDs and the synergetic effects of Pt and Pd and the enhanced electron transfer by graphene, the GPtPdNDs composites exhibited higher electrocatalytic activity and better tolerance to Pt nanoparticles supported on graphene (GPtNPs) and Pt/C for methanol oxidation

  17. Cellulose Nanocrystals--Bioactive Glass Hybrid Coating as Bone Substitutes by Electrophoretic Co-deposition: In Situ Control of Mineralization of Bioactive Glass and Enhancement of Osteoblastic Performance.

    Chen, Qiang; Garcia, Rosalina Pérez; Munoz, Josemari; Pérez de Larraya, Uxua; Garmendia, Nere; Yao, Qingqing; Boccaccini, Aldo R

    2015-11-11

    Surface functionalization of orthopedic implants is being intensively investigated to strengthen bone-to-implant contact and accelerate bone healing process. A hybrid coating, consisting of 45S5 bioactive glass (BG) individually wrapped and interconnected with fibrous cellulose nanocrystals (CNCs), is deposited on 316L stainless steel from aqueous suspension by a one-step electrophoretic deposition (EPD) process. Apart from the codeposition mechanism elucidated by means of zeta-potential and scanning electron microscopy measurements, in vitro characterization of the deposited CNCs-BG coating in simulated body fluid reveals an extremely rapid mineralization of BG particles on the coating (e.g., the formation of hydroxyapatite crystals layer after 0.5 day). A series of comparative trials and characterization methods were carried out to comprehensively understand the mineralization process of BG interacting with CNCs. Furthermore, key factors for satisfying the applicability of an implant coating such as coating composition, surface topography, and adhesion strength were quantitatively investigated as a function of mineralization time. Cell culture studies (using MC3T3-E1) indicate that the presence of CNCs-BG coating substantially accelerated cell attachment, spreading, proliferation, differentiation, and mineralization of extracellular matrix. This study has confirmed the capability of CNCs to enhance and regulate the bioactivity of BG particles, leading to mineralized CNCs-BG hybrids for improved bone implant coatings. PMID:26460819

  18. In Situ Fabrication of Bi2Ti2O7/TiO2 Heterostructure Submicron Fibers for Enhanced Photocatalytic Activity

    Zhou, Di; Yang, Hu; Tu, Yafang; Tian, Yu; Cai, Yaxuan; Hu, Zhenglong; Zhu, Xiaolong

    2016-04-01

    A facile two-step synthesis route combining electrospinning and hydrothermal techniques has been performed to obtain Bi2Ti2O7/TiO2 heterostructured submicron fibers. Bi2Ti2O7 nanosheets were grown on the surface of TiO2 submicron fibers. The density of the nanosheets increased with higher precursor concentration of the Bi/Ti reaction raw materials. UV-visible (UV-vis) diffuse reflectance spectroscopy indicated that the absorption spectrum of the Bi2Ti2O7/TiO2 composite extended into the visible-light region. Photocatalytic tests showed that the Bi2Ti2O7/TiO2 heterostructures possess a much higher degradation rate of rhodamine B than the unmodified TiO2 submicron fibers under visible light. The enhanced photocatalytic activity can be attributed to the synergistic effect between improved visible-light absorption and the internal electric field created by the heterojunctions. The effective separation of photogenerated carriers driven by the photoinduced potential was demonstrated by the photoelectrochemical analysis.

  19. In situ growth of vanadia-titania nano/micro-porous layers with enhanced photocatalytic performance by micro-arc oxidation

    Micro-arc oxidation process was used to synthesize V2O5-TiO2 porous layers for the first time. Surface morphology and topography of the layers were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques were also employed to evaluate phase structure and chemical composition of the layers. It was found that the V2O5-TiO2 layers consisted of anatase, rutile, and vanadium pentoxide phases fraction of which varied with the applied voltage and the electrolyte concentration. It was also revealed that pore size and surface roughness increased with the applied voltage and the electrolyte concentration. Optical properties of the layers were studied by a UV-vis spectrophotometer, and the band gap energies of the MAO-grown pure TiO2 and V2O5-TiO2 layers were respectively calculated as 3.21 and 2.56 eV. Furthermore, the composite layers exhibited a significantly enhanced photo-activity when compared to pure TiO2 layers. The photocatalytic reaction rate constants of degradation of methylene blue on the surface of the V2O5-TiO2 layers under ultraviolet and visible irradiations were measured as 0.0228 and 0.0117 min-1, respectively. As a consequence, micro-arc oxidation was deduced to be an appropriate and efficient method for synthesis of V2O5-TiO2 porous layers.

  20. Modeling in situ vitrification

    In Situ Vitrification (ISV) process is being assessed by the Idaho National Engineering Laboratory (INEL) to determine its applicability to transuranic and mixed wastes buried at INEL'S Subsurface Disposal Area (SDA). This process uses electrical resistance heating to melt waste and contaminated soil in place to produce a durable glasslike material that encapsulates and immobilizes buried wastes. This paper outlines the requirements for the model being developed at the INEL which will provide analytical support for the ISV technology assessment program. The model includes representations of the electric potential field, thermal transport with melting, gas and particulate release, vapor migration, off-gas combustion and process chemistry. The modeling objectives are to help determine the safety of the process by assessing the air and surrounding soil radionuclides and chemical pollution hazards, the nuclear criticality hazard, and the explosion and fire hazards, help determine the suitability of the ISV process for stabilizing the buried wastes involved, and help design laboratory and field tests and interpret results. 3 refs., 2 figs., 1 tab

  1. Enhanced thermal and mechanical properties of poly(trimethylene terephthalate-block-poly(tetramethylene oxide segmented copolymer based hybrid nanocomposites prepared by in situ polymerization via synergy effect between SWCNTs and graphene nanoplatelets

    S. Paszkiewicz

    2015-06-01

    Full Text Available Graphene nanoplatelets/single walled carbon nanotubes/poly(trimethylene terephthalate-block-poly(tetramethylene oxide segmented copolymer (GNP/SWCNT/PTT-PTMO hybrid nanocomposites were synthesized via in situ polymerization. A remarkable synergistic effect between GNPs and SWCNTs on improving thermal and mechanical properties of nanocomposites based on segmented block copolymers was observed. Heterogeneous structure of the PTT-PTMO allowed for a better and more uniform distribution of both types of nanoparticles and stabilized the structure in question. This enabled us to observe a so-called synergistic effect, caused by the use of mixture of carbon nanotubes and graphene nanopletelets, on the enhancement of thermal and mechanical properties of the obtained polymer. In order to ascertain the influence of mentioned carbon nanostructures on the nano-phase-separated structure of the synthesized PTT-PTMO block copolymers, differential scanning calorimetric (DSC and dynamic mechanical thermoanalysis (DMTA measurements were performed. Scanning electron microscopic (SEM and transmission electron microscopic (TEM images of the PTTPTMO nanocomposites displayed that hybrid nanofillers exhibited better distribution and compatibility than SWCNTs and GNPs did individually. The tensile modulus of 0.5SWCNT/0.1GNP/PTT-PTMO composites was 68% higher than that of the PTT-PTMO alone, compared to only a 10 and 28% increase in tensile modulus for 0.3GNP/PTT-PTMO and 0.3SWCNT/PTT-PTMO composites respectively (the highest concentration when single nanofiller was added.

  2. In-situ uranium leaching

    This invention provides a method for improving the recovery of mineral values from ore bodies subjected to in-situ leaching by controlling the flow behaviour of the leaching solution. In particular, the invention relates to an in-situ leaching operation employing a foam for mobility control of the leaching solution. A foam bank is either introduced into the ore bed or developed in-situ in the ore bed. The foam then becomes a diverting agent forcing the leaching fluid through the previously non-contacted regions of the deposit

  3. In Situ Aerosol Detector Project

    National Aeronautics and Space Administration — NASA is developing new platform systems that have the potential to benefit Earth science research activities, which include in situ instruments for atmospheric...

  4. In situ leaching of uranium

    A process is described for the in-situ leaching of uranium-containing ores employing an acidic leach liquor containing peroxymonosulphuric acid. Preferably, additionally, sulphuric acid is present in the leach liquor. (author)

  5. In Situ Non-Invasive T2*-Weighted MRI Derived Parameters Determine Ex Vivo Structural Properties of an ACL Reconstruction or Bio-enhanced Primary Repair in a Porcine Model

    Biercevicz, Alison M.; Miranda, Danny L.; Machan, Jason T.; Murray, Martha M.; Fleming, Braden C.

    2012-01-01

    Background Magnetic resonance imaging (MRI) is a noninvasive technology that can quantitatively access ACL graft size and signal intensity. However, how those properties relate to reconstructed or repaired ligament strength during the healing process is yet unknown. Purpose We hypothesized that MR derived measures of graft volume and signal intensity are significant predictors of the structural properties of a healing ACL or ACL graft after 15 weeks and 52 weeks of healing. Study Design Controlled Laboratory Experiment Methods The current data were gathered from two experiments evaluating ACL reconstruction and repair techniques. In the first experiment, pigs underwent unilateral ACL transection and received: 1) ACL reconstruction, 2) ACL reconstruction with collagen platelet composite (CPC), or 3) no treatment. The surgical legs were harvested following 15 weeks of healing. In the second experiment, pigs underwent ACL transection and received: 1) ACL reconstruction, 2) ACL reconstruction with CPC, 3) bio-enhanced ACL primary repair with CPC, or 4) no treatment. The surgical legs were harvested after 52 weeks. The harvested knees were imaged using a T2* weighted 3D-CISS sequence. Each ligament was segmented from the scans, and the intra-articular volume and the median grayscale values were determined. Mechanical testing was performed to establish the ligament structural properties. Results Volume significantly predicted the structural properties (maximum load, yield load, linear stiffness) of the ligaments and grafts (R2 = 0.56, 0.56, 0.49; p?0.001). Likewise, the median grayscale values significantly predicted the structural properties of the ligaments and grafts (R2 = 0.42, 0.37, 0.40; p<0.001). The combination of these two parameters in a multiple regression model improved the predictions (R2 = 0.73, 0.72, 0.68; p?0.001). Conclusion Volume and grayscale values from high resolution T2* weighted MRI images are predictive of structural properties of the healing ligament or graft in a porcine model. Clinical Relevance This study provides a critical step in the development of a non-invasive method to predict the structural properties of the healing ACL graft or repair. This technique may prove beneficial as a surrogate outcome measure in pre-clinical animal and clinical studies. PMID:23348076

  6. In situ solution mining technique

    A method of in situ solution mining is disclosed in which a primary leaching process employing an array of 5-spot leaching patterns of production and injection wells is converted to a different pattern by converting to injection wells all the production wells in alternate rows

  7. In situ biofilm coupon device

    Peyton, Brent M. (Kennewick, WA); Truex, Michael J. (Richland, WA)

    1997-01-01

    An apparatus for characterization of in-situ microbial biofilm populations in subsurface groundwater. The device permits biofilm-forming microorganisms to adhere to packing material while emplaced in a groundwater strata, so that the packing material can be later analyzed for quantity and type of microorganisms, growth rate, and nutrient requirements.

  8. In situ dehydration of yugawaralite

    Artioli, G.; Ståhl, Kenny; Cruciani, G.; Gualtieri, A.; Hanson, J. C.

    The structural response of the natural zeolite yugawaralite (CaAl2Si6O16. 4H(2)O) upon thermally induced dehydration has been studied by Rietveld analysis of temperature-resolved powder diffraction data collected in situ in the temperature range 315-791 K using synchrotron radiation. The room-tem...

  9. In situ bypass og diabetes

    Jensen, Leif Panduro; Schroeder, T V; Lorentzen, J E

    1993-01-01

    From 1986 through to 1990 a total of 483 in situ bypass procedures were performed in 444 patients. Preoperative risk-factors were equally distributed among diabetic (DM) and non-diabetic (NDM) patients, except for smoking habits (DM:48%, NDM:64%, p = 0.002) and cardiac disease (DM:45%, NDM:29%, p...

  10. In situ uranium stabilization by microbial metabolites

    Microbial melanin production by autochthonous bacteria was explored in this study as a means to increase U immobilization in U contaminated soil. This article demonstrates the application of bacterial physiology and soil ecology for enhanced U immobilization in order to develop an in situ, U bio-immobilization technology. We have demonstrated microbial production of a metal chelating biopolymer, pyomelanin, in U contaminated soil from the Tims Branch area of the Department of Energy (DOE), Savannah River Site (SRS), South Carolina, as a result of tyrosine amendments. Bacterial densities of pyomelanin producers were >106 cells per g wet soil. Pyomelanin demonstrated U complexing and mineral binding capacities at pH 4 and 7. In laboratory studies, in the presence of goethite or illite, pyomelanin enhanced U sequestration by these minerals. Tyrosine amended soils in a field test demonstrated increased U sequestration capacity following pyomelanin production up to 13 months after tyrosine treatments

  11. In situ atomic force microscope imaging of supported lipid bilayers

    Kaasgaard, Thomas; Leidy, Chad; Ipsen, John Hjorth; Mouritsen, Ole G.; Jrgensen, Kent

    2001-01-01

    In situ AFM images of phospholipase A/sub 2/ (PLA/sub 2/) hydrolysis of mica-supported one- and two-component lipid bilayers are presented. For one-component DPPC bilayers an enhanced enzymatic activity is observed towards preexisting defects in the bilayer. Phase separation is observed in two...

  12. Single cylinder in situ scanning electron microscope fatigue system

    This article introduces a single cylinder fatigue machine adaptable to a scanning electron microscope chamber. The machine includes a node control mechanism to create a still observation node at any location on the specimen as fatigue cycling occurs, thereby allowing a point of interest to remain within view. The exceptional stability of this machine enables improved in situ study of the fatigue cracking phenomenon. For example, an in situ machine enhances the researcher's ability to record material structural changes that precede crack nucleation and allows observation of the influences of microstructure (grain structure) on the early stages of crack propagation

  13. IN SITU URANIUM STABILIZATION BY MICROBIAL METABOLITES

    Turick, C; Anna Knox, A; Chad L Leverette,C; Yianne Kritzas, Y

    2006-11-29

    Soil contaminated with U was the focus of this study in order to develop in-situ, U bio-immobilization technology. We have demonstrated microbial production of a metal chelating biopolymer, pyomelanin, in U contaminated soil from the Tims Branch area of the Department of Energy (DOE) Savannah River Site (SRS) as a result of tyrosine amendments. Bacterial densities of pyomelanin producers were >106 cells/g wet soil. Pyomelanin demonstrated U chelating and mineral binding capacities at pH 4 and 7. In laboratory studies, in the presence of goethite or illite, pyomelanin enhanced U sequestration by these minerals. Tyrosine amended soils in field tests demonstrated increased U sequestration capacity following pyomelanin production up to 13 months after tyrosine treatments.

  14. Four Models of In Situ Simulation

    Musaeus, Peter; Krogh, Kristian; Paltved, Charlotte

    2014-01-01

    four fruitful approaches to in situ simulation: (1) In situ simulation informed by reported critical incidents and adverse events from emergency departments (ED) in which team training is about to be conducted to write scenarios. (2) In situ simulation through ethnographic studies at the ED. (3) Using....... Perspective and relevance Empirical and theoretical research is needed to develop in situ simulation and to theorize and experiment with how we best take reported critical incidents and adverse events back to the clinic. In situ simulation offers a unique way to study team interactions there are widely...

  15. Oil field development using in-situ combustion in combination with foam systems and alkaline solution

    Abasov, M.T.; Khismetov, T.V. (Inst. of Deep Oil and Deposits, Academy of Sciences, Azerbaijanu (USSR))

    1991-01-01

    In this paper the results of experimental and field investigation of enhanced oil recovery (EOR) methods combining in-situ combustion with foam systems injection and alkaline flooding are generalized. 4 figs.

  16. An evaluation of satellite and in situ based sea surface temperature datasets in the North Indian Ocean region

    Sreejith, O.P.; Shenoi, S.S.C.

    Satellite based daily fields of Pathfinder SST (PFSST) and blended-analysed fields like National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) and Reynolds weekly SST data were compared with the in situ...

  17. In situ treatability test plan

    This document describes the plans for the in situ treatment zone (ISTZ) treatability test for groundwater contaminated with strontium-90. The treatability test is to be conducted at the Hanford Site in Richland, Washington, in a portion of the 100-N Area adjacent to the Columbia River referred to as N-Springs. The purpose of the treatability test is to evaluate the effectiveness of an innovative technology to prevent the discharge of strontium-90 contaminated groundwater into the Columbia River. The ISTZ is a passive technology that consists of placing a treatment agent in the path of the groundwater. The treatment agent must restrict target radioactive contaminants and provide time for the contaminant to decay to acceptable levels. The permeability of the treatment zone must be greater than or equal to that of the surrounding sediments to ensure that the contaminated groundwater flows through the treatment zone agent and not around the agent

  18. DOE In Situ Remediation Integrated Program

    The In Situ Remediation Integrated Program (ISRP) supports and manages a balanced portfolio of applied research and development activities in support of DOE environmental restoration and waste management needs. ISRP technologies are being developed in four areas: containment, chemical and physical treatment, in situ bioremediation, and in situ manipulation (including electrokinetics). the focus of containment is to provide mechanisms to stop contaminant migration through the subsurface. In situ bioremediation and chemical and physical treatment both aim to destroy or eliminate contaminants in groundwater and soils. In situ manipulation (ISM) provides mechanisms to access contaminants or introduce treatment agents into the soil, and includes other technologies necessary to support the implementation of ISR methods. Descriptions of each major program area are provided to set the technical context of the ISM subprogram. Typical ISM needs for major areas of in situ remediation research and development are identified

  19. A bio-inspired approach for in situ synthesis of tunable adhesive

    Inspired by the strong adhesive produced by English ivy, this paper proposes an in situ synthesis approach for fabricating tunable nanoparticle enhanced adhesives. Special attention was given to tunable features of the adhesive produced by the biological process. Parameters that may be used to tune properties of the adhesive will be proposed. To illustrate and validate the proposed approach, an experimental platform was presented for fabricating tunable chitosan adhesive enhanced by Au nanoparticles synthesized in situ. This study contributes to a bio-inspired approach for in situ synthesis of tunable nanocomposite adhesives by mimicking the natural biological processes of ivy adhesive synthesis. (paper)

  20. Training for teamwork through in situ simulations

    Sorensen, Asta; Poehlman, Jon; Bollenbacher, John; Riggan, Scott; Davis, Stan; Miller, Kristi; Ivester, Thomas; Kahwati, Leila

    2015-01-01

    In situ simulations allow healthcare teams to practice teamwork and communication as well as clinical management skills in a team's usual work setting with typically available resources and equipment. The purpose of this video is to demonstrate how to plan and conduct in situ simulation training sessions, with particular emphasis on how such training can be used to improve communication and teamwork. The video features an in situ simulation conducted at a labour and delivery unit in response ...

  1. Innovative Raman spectroscopic concepts for in situ monitoring of chemicals in seawater

    Sowoidnich, Kay; Fernández López, María.; Kronfeldt, Heinz-Detlef

    2013-05-01

    Optical sensors based on Raman spectroscopy are suitable for a rapid identification and quantification of pollutants such as Polycyclic Aromatic Hydrocarbons (PAHs). Additionally, Surface enhanced Raman spectroscopy (SERS) has gained increasing attention as a powerful technique for in-situ monitoring of these substances in seawater to achieve limits of detection (LODs) in the sub-nmol/l range. A low-cost method based on electroless plating solution of chloroauric acid (HAuCl4) and hydrogen peroxide (H2O2) was developed in our group to construct a gold island film as SERS substrate to achieve a well reproducible, high sensitive and seawater resistant SERS sensor. The substrates show good resistance against seawater determined by long-term stability tests carried out over 12 weeks of storage of the substrates in artificial seawater. The investigations show that the substrates still have about 50 % of their initial activity after 4 weeks of storage and about 15 % after two months. This type of substrate is reproducible with variability in the SERS intensities of about 8 %. Shifted excitation Raman difference spectroscopy (SERDS) was applied by using a microsystem diode laser emitting at 784.3 nm and 784.8 nm to remove the fluorescence interference and to improve the Raman signals. This combination of SERS and SERDS yields a limit of detection of 1 nmol/l for pyrene which was selected as representative PAH. These quantitative results show that the designed SERS substrates are suitable for the in-situ monitoring of PAHs in the marine environment.

  2. Methods and systems for in-situ electroplating of electrodes

    Zappi, Guillermo Daniel; Zarnoch, Kenneth Paul; Huntley, Christian Andrew; Swalla, Dana Ray

    2015-06-02

    The present techniques provide electrochemical devices having enhanced electrodes with surfaces that facilitate operation, such as by formation of a porous nickel layer on an operative surface, particularly of the cathode. The porous metal layer increases the surface area of the electrode, which may result in increasing the efficiency of the electrochemical devices. The formation of the porous metal layer is performed in situ, that is, after the assembly of the electrodes into an electrochemical device. The in situ process offers a number of advantages, including the ability to protect the porous metal layer on the electrode surface from damage during assembly of the electrochemical device. The enhanced electrode and the method for its processing may be used in any number of electrochemical devices, and is particularly well suited for electrodes in an electrolyzer useful for splitting water into hydrogen and oxygen.

  3. In situ remediation integrated program: Development of containment technology

    The In Situ Remediation Integrated Program (ISR IP) is supporting the development of subsurface containment barrier technology for use in site restoration applications at contaminated sites throughout the US Department of Energy (DOE) complex. The types of subsurface barriers being developed include impermeable barriers and sorbent barriers. The specific containment technology projects described in this paper include frozen soil barriers, flowable grout techniques, hydraulic and diffusion barriers, horizontal grout barriers, chemically enhanced barriers, and viscous liquid barriers

  4. Technology assessment of in situ uranium mining

    The objective of the PNL portion of the Technology Assessment project is to provide a description of the current in situ uranium mining technology; to evaluate, based on available data, the environmental impacts and, in a limited fashion, the health effects; and to explore the impediments to development and deployment of the in situ uranium mining technology

  5. In situ simulation: Taking reported critical incidents and adverse events back to the clinic

    Juul, Jonas; Paltved, Charlotte; Krogh, Kristian; Musaeus, Peter

    2014-01-01

    adverse events coupled with a contextual needs analysis and short-term observations might aid in scenario design for in situ simulation. This will shed light on how to develop specific learning goals for in situ simulation based on clinical challenges in acute healthcare settings. Third, in situ......Introduction In situ simulation offers a novel approach to training in the healthcare setting. It models clinical processes in a real clinical environment and provides the opportunity to correct errors and adjust team interactions without endangering patients. Training in the simulation laboratory...... improve patient safety if coupled with training and organisational support2. Insight into the nature of reported critical incidents and adverse events can be used in writing in situ simulation scenarios and thus lead to interventions that enhance patient safety. The patient safety literature emphasises...

  6. Enhancement of growth and structure properties of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin layers by in situ incorporation of gold nano-clusters

    Erlebach, Ralf; Huebner, Michael; Christke, Sandra; Grosse, Veit; Schmidl, Frank; Seidel, Paul [Friedrich-Schiller-University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena (Germany); Kraeusslich, Juergen [Friedrich-Schiller-University Jena, Institute of Optics and Quantum Electronics, Max-Wien-Platz 1, 07743 Jena (Germany); Rettenmayr, Markus [Friedrich-Schiller-University Jena, Institute of Materials Science and Technology, Loebdergraben 32, 07743 Jena (Germany)

    2011-07-01

    For most hetero-epitactic growth techniques, structural defects due to the lattice misfit, namely tilts, precipitates or holes, turn out to be limiting factors for the successful fabrication of multilayer systems. A new approach of an in situ growth technique dealing with this problem by incorporation of gold nano-clusters is examined. Therefore, pulsed laser deposition (PLD) of a high-T{sub C} YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) layer onto a strontium titanate (STO) template with a temporary interlayer of gold with a well-defined film thickness is investigated. Within this process, the gold interlayer shows nano-clustering behavior. Effects on the properties of structure like crystallographic or surface features of the ablated YBCO layer by variation of the film thickness of the gold and YBCO layers are presented. Moreover, distribution and clustering behavior of the crystallized gold nano-particles as well as the basic superconducting properties of the layer system are analyzed.

  7. At Least 39 Weeks

    Full Text Available ... Ovulation calendar 39 weeks is best Order bereavement materials News Moms Need Blog News & Media News Videos Mission ... Ovulation calendar 39 weeks is best Order bereavement materials News Moms Need Blog Stories & Media News & Media News ...

  8. At Least 39 Weeks

    Full Text Available ... questions Ask our health experts Calculating your due date Ovulation calendar 39 weeks is best Order bereavement ... questions Ask our health experts Calculating your due date Ovulation calendar 39 weeks is best Order bereavement ...

  9. At Least 39 Weeks

    Full Text Available ... Ovulation calendar 39 weeks is best Order bereavement materials News Moms Need Blog News & Media News Videos ... Ovulation calendar 39 weeks is best Order bereavement materials News Moms Need Blog Stories & Media News & Media ...

  10. Discerning in situ performance of an eor agent in the midst of geological uncertainty:

    Fatemi, S.A.; Jansen, J.D.; Rossen, W.R.

    2015-01-01

    An enhanced-oil-recovery pilot test has multiple goals, among them to verify the properties of the EOR agent in situ. Given the complexity of EOR processes and the inherent uncertainty in the reservoir description, it is a challenge to discern the properties of the EOR agent in situ. We present a simple case study to illustrate this challenge: a polymer EOR process in a 2D layer-cake reservoir. The intended polymer design value is 21 cp in situ but we allow it might be that intended in the ...

  11. Magic angle spinning nuclear magnetic resonance apparatus and process for high-resolution in situ investigations

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Mehta, Hardeep S.; Peden, Charles H. F.

    2015-11-24

    A continuous-flow (CF) magic angle sample spinning (CF-MAS) NMR rotor and probe are described for investigating reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions in situ. The rotor includes a sample chamber of a flow-through design with a large sample volume that delivers a flow of reactants through a catalyst bed contained within the sample cell allowing in-situ investigations of reactants and products. Flow through the sample chamber improves diffusion of reactants and products through the catalyst. The large volume of the sample chamber enhances sensitivity permitting in situ .sup.13C CF-MAS studies at natural abundance.

  12. In-situ SHG and Raman spectroscopy at electrodes

    Second harmonic generation and surface Raman spectroscopy at metal electrodes are in-situ spectroscopies for the study of the metallic and electrolyte side of the electric double layer at the interface, and in this sense both spectroscopies are supplemental to some extent: Surface (un)enhanced Raman spectroscopy yields via vibronic spectra insight in electrochemical processes such as adsorption or reaction pathways. With second harmonic generation, however, one can monitor in-situ at a Au(111) electrode not only the formation or lifting of the (1x23) surface reconstruction, but also (indirectly) the specific adsorption of ions as they alter the non-linear in-plane and perpendicular polarizability of metal electrons at the interface in a distinct way. Hence, chemisorption processes can be studied in a novel way. (author). 90 refs, 1 fig., 1 tab

  13. In situ Gas Conditioning in Fuel Reforming for Hydrogen Generation

    Bandi, A.; Specht, M.; Sichler, P.; Nicoloso, N.

    2002-09-20

    The production of hydrogen for fuel cell applications requires cost and energy efficient technologies. The Absorption Enhanced Reforming (AER), developed at ZSW with industrial partners, is aimed to simplify the process by using a high temperature in situ CO2 absorption. The in situ CO2 removal results in shifting the steam reforming reaction equilibrium towards increased hydrogen concentration (up to 95 vol%). The key part of the process is the high temperature CO2 absorbent. In this contribution results of Thermal Gravimetric Analysis (TGA) investigations on natural minerals, dolomites, silicates and synthetic absorbent materials in regard of their CO2 absorption capacity and absorption/desorption cyclic stability are presented and discussed. It has been found that the inert parts of the absorbent materials have a structure stabilizing effect, leading to an improved cyclic stability of the materials.

  14. Design Games for In-Situ Design

    Kristiansen, Erik

    2013-01-01

    design problem where an in-situ design practice may further the early design process: the case of designing a pervasive game. Pervasive games are computer games, played using the city as a game board and often using mobile phones with GPS. Some contextual design methods exist, but we propose an approach...... that calls for the designer to conceptualise and perform ideas in-situ, that is on the site, where the game is supposed to be played. The problem was to design a creativity method that incorporated in-situ design work and which generated game concepts for pervasive games. The proposed design method...

  15. In Situ Mechanical Testing Techniques for Real-Time Materials Deformation Characterization

    Rudolf, Chris; Boesl, Benjamin; Agarwal, Arvind

    2016-01-01

    In situ mechanical property testing has the ability to enhance quantitative characterization of materials by revealing the occurring deformation behavior in real time. This article will summarize select recent testing performed inside a scanning electron microscope on various materials including metals, ceramics, composites, coatings, and 3-Dimensional graphene foam. Tensile and indentation testing methods are outlined with case studies and preliminary data. The benefits of performing a novel double-torsion testing technique in situ are also proposed.

  16. Scientific rationale of Saturn's in situ exploration

    Mousis, O; Lebreton, J -P; Wurz, P; Cavalié, T; Coustenis, A; Courtin, R; Gautier, D; Helled, R; Irwin, P G J; Morse, A D; Nettelmann, N; Marty, B; Rousselot, P; Venot, O; Atkinson, D H; Waite, J H; Reh, K R; Simon-Miller, A; Atreya, S; André, N; Blanc, M; Daglis, I A; Fischer, G; Geppert, W D; Guillot, T; Hedman, M M; Hueso, R; Lellouch, E; Lunine, J I; Murray, C D; O'Donoghue, J; Rengel, M; Sanchez-Lavega, A; Schmider, F -X; Spiga, A; Spilker, T; Petit, J -M; Tiscareno, M S; Ali-Dib, M; Altwegg, K; Bouquet, A; Briois, C; Fouchet, T; Guerlet, S; Kostiuk, T; Lebleu, D; Moreno, R; Orton, G S; Poncy, J

    2014-01-01

    Remote sensing observations meet some limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the superiority of in situ probe measurements is illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. This paper describes the main scientific goals to be addressed by the future in situ exploration of Saturn placing the Galileo probe exploration of Jupiter in a broader context and before the future probe exploration of the more remote ice giants. In situ exploration of Saturn's atmosphere addresses two broad themes that are discussed throughout this paper: first, the formation history of our solar system and second, the processes at play in planetary atmospheres. In this context, we detail the reasons why measurements of Saturn's bulk element...

  17. In-situ characterization of heterogeneous catalysts

    Rodriguez, Jose A; Chupas, Peter J

    2013-01-01

    Helps researchers develop new catalysts for sustainable fuel and chemical production Reviewing the latest developments in the field, this book explores the in-situ characterization of heterogeneous catalysts, enabling readers to take full advantage of the sophisticated techniques used to study heterogeneous catalysts and reaction mechanisms. In using these techniques, readers can learn to improve the selectivity and the performance of catalysts and how to prepare catalysts as efficiently as possible, with minimum waste. In-situ Characterization of Heterogeneous Catalysts feat

  18. In-situ Ground-Based and Airborne Formaldehyde Measurements in the Houston Area During TexAQS-II

    Rappenglueck, B.; Byun, D.; Alvarez, S.; Buhr, M.; Coarfa, V.; Czader, B.; Dasgupta, P.; Estes, M.; Kim, S.; Leuchner, M.; Luke, W.; Shauck, M.; Zanin, G.

    2007-12-01

    Formaldehyde is considered to play a significant role in summertime photochemistry in the Houston area, in particular it is considered an important source for radicals. Secondary formation seems to be the most important fraction of ambient HCHO. Enhanced nighttime values may indicate primary sources. Potential sources may include mobile sources such as traffic exhaust, in particular not well maintained Diesel engines. Other possible sources may include point sources such as coffee roasting and flares from refineries. In this study we focused on the TexAQS-II continuous in-situ formaldehyde data set based on Hantzsch reaction which was obtained in the Ship Channel area (HRM3 and Lynchburg Ferry site) and at the Moody Tower for several weeks. We also include in-situ HCHO measurements obtained with the same technique aboard the Baylor aircraft during TexAQS-II flight missions. Formaldehyde data was compared to several trace gases that are supposed to be coemitted including CO (traffic), ethylene (flares), and SO2 (industry). In order to keep photochemical processes at a minimum special focus was on nighttime data. Case studies will be discussed where meteorological conditions including recirculation and boundary layer developments seem to play a major role in the redistribution of HCHO. Observations will be compared to CMAQ model studies.

  19. In Situ Measurement of Tritium Permeation Through Stainless Steel

    Luscher, Walter G.; Senor, David J.; Clayton, Kevin; Longhurst, Glen

    2013-06-01

    The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292 and 330C. In-situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. An irradiation enhancement factor (IEF) was determined by comparing in-situ permeation data with a correlation for ex-reactor hydrogen permeation through austenitic stainless steel developed from literature data and reported by Le Claire. Nominal values for the IEF ranged between 3 and 5 for 316 SS. In-situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

  20. IN-SITU MEASUREMENT OF TRITIUM PERMEATION THROUGH STAINLESS STEEL

    Luscher, Walter G.; Senor, David J.; Clayton, Kevin; Longhurst, Glen R.

    2013-06-01

    The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292 and 330C. In-situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. An irradiation enhancement factor (IEF) was determined by comparing in-situ permeation data with a correlation for ex-reactor hydrogen permeation through austenitic stainless steel developed from literature data and reported by Le Claire. Nominal values for the IEF ranged between 3 and 5 for 316 SS. In-situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

  1. Demonstration testing and evaluation of in situ soil heating

    A Treatability Study planned for the demonstration of the in situ electromagnetic (EM) heating process to remove organic solvents is described in this Work Plan. The treatability study will be conducted by heating subsurface vadose-zone soils in an organic plume adjacent to the Classified Burial Ground K-1070-D located at K-25 Site, Oak Ridge. The test is scheduled to start during the fourth quarter of FY94 and will be completed during the first quarter of FY95. The EM heating process for soil decontamination is based on volumetric heating technologies developed during the '70s for the recovery of fuels from shale and tar sands by IIT Research Institute (IITRI) under a co-operative program with the US Department of Energy (DOE). Additional modifications of the technology developed during the mid '80s are currently used for the production of heavy oil and waste treatment. Over the last nine years, a number of Government agencies (EPA, Army, AF, and DOE) and industries sponsored further development and testing of the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site under the proposed treatability study. Most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 to 95 C. The efficiency of the treatment will be determined by comparing the concentration of contaminants in soil samples. Samples will be obtained before and after the demonstration for a measurement of the concentration of contaminants of concern

  2. Excursion control at in situ uranium mines

    Intensive research and development of in situ uranium mining took place in the United States during the 1970's. By the end of the decade, nearly 10% of all uranium production came from in situ mines. Recent poor market conditions, however, forced the closure of all domestic in situ uranium mines. When market conditions improve, domestic in situ mining is expected to make a modest recovery. Successful licensing of future in situ mines depends to a large extend on the ability to contain the leach solutions (lixiviant) within the ore zone. Uncontrolled movement of lixiviant beyond the ore zone is called an excursion. Early detection of an excursion is a necessary prelude to the implementation of timely corrective action to return escaping fluid to the well-field. Without timely corrective action, a large quantity of valuable production fluid may be irretrievably lost and serious contamination of adjacent groundwater resources may result. Two types of excursion are recognized: horizontal and vertical. In horizontal excursions lixiviant remains strata bound but migrates laterally away from the production well-field. In vertical excursions lixiviant escapes into aquifers above or below the ore bearing strata

  3. In situ forming polymeric drug delivery systems

    Madan M

    2009-01-01

    Full Text Available In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid, poly(DL-lactide-co-glycolide and poly-caprolactone. The choice of solvents like water, dimethylsulphoxide, N-methyl pyrrolidone, triacetin and 2-pyrrolidone for these formulations depends on the solubility of polymer used. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost.

  4. Fabrication of in-situ grown graphene reinforced Cu matrix composites.

    Chen, Yakun; Zhang, Xiang; Liu, Enzuo; He, Chunnian; Shi, Chunsheng; Li, Jiajun; Nash, Philip; Zhao, Naiqin

    2016-01-01

    Graphene/Cu composites were fabricated through a graphene in-situ grown approach, which involved ball-milling of Cu powders with PMMA as solid carbon source, in-situ growth of graphene on flaky Cu powders and vacuum hot-press sintering. SEM and TEM characterization results indicated that graphene in-situ grown on Cu powders guaranteed a homogeneous dispersion and a good combination between graphene and Cu matrix, as well as the intact structure of graphene, which was beneficial to its strengthening effect. The yield strength of 244?MPa and tensile strength of 274?MPa were achieved in the composite with 0.95?wt.% graphene, which were separately 177% and 27.4% enhancement over pure Cu. Strengthening effect of in-situ grown graphene in the matrix was contributed to load transfer and dislocation strengthening. PMID:26763313

  5. MENDING THE IN SITU MANIPULATION BARRIER

    PETERSEN, S.W.

    2006-02-06

    In early 2004, the U.S. Department of Energy (DOE) Richland and Fluor Hanford requested technical assistance from the DOE Headquarters EM-23 Technical Assistance Program to provide a team of technical experts to develop recommendations for mending the In Situ Redox Manipulation (ISRM) Barrier in the 100-D Area of the Hanford Site in Washington State. To accommodate this request, EM-23 provided support to convene a group of technical experts from industry, a national laboratory, and a DOE site to participate in a 2 1/2-day workshop with the objective of identifying and recommending options to enhance the performance of the 100-D Area reactive barrier and of a planned extension to the northeast. This report provides written documentation of the team's findings and recommendations. In 1995, a plume of dissolved hexavalent chromium [Cr(VI)], which resulted from operation of the D/DR Reactors at the Hanford site, was discovered along the Columbia River shoreline and in the 100-D Area. Between 1999 and 2003, a reactive barrier using the In Situ Redox Manipulation (ISRM) technology, was installed a distance of 680 meters along the river to reduce the Cr(VI) in the groundwater. The ISRM technology creates a treatment zone within the aquifer by injection of sodium dithionite, a strong reducing agent that scavenges dissolved oxygen (DO) from the aquifer and reduces ferric iron [Fe(III)], related metals, and oxy-ions. The reduction of Fe(III) to ferrous [Fe(II)] iron provides the primary reduction capacity to reduce Cr(VI) to the +3 state, which is less mobile and less toxic. Bench-scale and field-scale treatability tests were initially conducted to demonstrate proof-of principle and to provide data for estimation of barrier longevity. These calculations estimated barrier longevity in excess of twenty years. However, several years after initial and secondary treatment, groundwater in a number of wells has been found to contain elevated chromium (Cr) concentrations, indicating some loss of reductive capacity within the aquifer. The Technical Assistance Team (TAT) was requested to perform the following activities: (1) evaluate the most probable condition(s) that has led to the presence of Cr(VI) in 12 different barrier wells (i.e. premature loss of reductive capacity), (2) recommend methods for determining the cause of the problem, (3) recommend methods for evaluating the magnitude of the problem, (4) recommend practicable method(s) for mending the barrier that involves a long-term solution, and (5) recommend methods for extending the barrier to the northeast (e.g., changing injection procedure, changing or augmenting the injected material). Since the March 2004 workshop, a decision has been made to place a hold on the barrier extension until more is known about the cause of the problem. However, the report complies with the original request for information on all of the above activities, but focuses on determining the cause of the problem and mending of the existing barrier.

  6. in situ Calcite Precipitation for Contaminant Immobilization

    Yoshiko Fujita; Robert W. Smith

    2009-08-01

    in situ Calcite Precipitation for Contaminant Immobilization Yoshiko Fujita (Yoshiko.fujita@inl.gov) (Idaho National Laboratory, Idaho Falls, Idaho, USA) Robert W. Smith (University of Idaho-Idaho Falls, Idaho Falls, Idaho, USA) Subsurface radionuclide and trace metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE’s greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent trace ions, such as the short-lived radionuclide strontium-90, is co-precipitation in calcite. Calcite, a common mineral in the arid western U.S., can form solid solutions with trace metals. The rate of trace metal incorporation is susceptible to manipulation using either abiotic or biotic means. We have previously demonstrated that increasing the calcite precipitation rate by stimulating the activity of urea hydrolyzing microorganisms can result in significantly enhanced Sr uptake. Urea hydrolysis causes the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity, and also by liberating the reactive cations from the aquifer matrix via exchange reactions involving the ammonium ion derived from urea: H2NCONH2 + 3H2O ? 2NH4+ + HCO3- + OH- urea hydrolysis >X:2Ca + 2NH4+ ? 2>X:NH4 + Ca2+ ion exchange Ca2+ + HCO3- + OH- ? CaCO3(s) + H2O calcite precipitation where >X: is a cation exchange site on the aquifer matrix. This contaminant immobilization approach has several attractive features. Urea hydrolysis is catalyzed by the urease enzyme, which is produced by many indigenous subsurface microorganisms. Addition of foreign microbes is unnecessary. In turn the involvement of the native microbes and the consequent in situ generation of reactive components in the aqueous phase (e.g., carbonate and Ca or Sr) can allow dissemination of the reaction over a larger volume and/or farther away from an amendment injection point, as compared to direct addition of the reactants at a well (which can lead to clogging). A final particularly attractive characteristic of this approach is its long-term sustainability; the remediation scheme is geared toward environments that are already saturated with respect to calcite, and in such systems the bulk of any newly precipitated calcite will remain stable once engineered manipulations cease. This means that the co-precipitated contaminants will be effectively sequestered over the long term. We are currently conducting integrated field, laboratory, and computational research to evaluate a) the relationships between urea hydrolysis rate, calcite precipitation rate, and trace metal partitioning under environmentally relevant conditions; and b) the coupling between flow/flux manipulations and calcite precipitate distribution and metal uptake. We are also assessing the application of geophysical and molecular biological tools to monitor the relevant chemical and physical processes. The primary emphasis is on field-scale processes, with the laboratory and modeling activities designed specifically to support the field studies. Field experiments are being conducted in perched water (vadose zone) at the Vadose Zone Research Park (VZRP) at the Idaho National Laboratory; the VZRP provides an uncontaminated setting that is an analog of the 90Sr-contaminated vadose zone at the Idaho Nuclear Technology and Engineering Center. A summary of results to date will be presented.

  7. At Least 39 Weeks

    Full Text Available ... Conference 2015 Prematurity research centers What is team science? A unique Transdisciplinary Approach More than 75 years ... questions Ask our health experts Calculating your due date Ovulation calendar 39 weeks is best Order bereavement ...

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    Full Text Available ... for your baby Feeding your baby Common illnesses New parents Family health & safety Complications & Loss Pregnancy complications ... 37 Prenatal care: Early pregnancy visits 4:56 New Partnership 1:10 39 weeks public service announcement ...

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    Full Text Available ... Your e-mail was sent. Save to my dashboard Sign in or Sign up to save this ... saved this page It's been added to your dashboard . At least 39 weeks 3:36 Stanford Prematurity ...

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    Full Text Available ... premature birth and infant mortality. Solving premature birth Stanford University Prematurity Research Center Featured articles The impact ... your dashboard . At least 39 weeks 3:36 Stanford Prematurity Research Center Launch 3:25 Newborn care: ...

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    Full Text Available ... 39 weeks Description | Related videos | Most played video E-mail to a friend Please fill in all fields. Please enter a valid e-mail address. Your information: Your recipient's information: Your ...

  12. In Vivo Osteogenic Differentiation of Human Embryoid Bodies in an Injectable in Situ-Forming Hydrogel

    Moon Suk Kim; Seung-Yup Ku; Shin Yong Moon; Yoon Young Kim; Hai Bang Lee; Da Yeon Kim

    2013-01-01

    In this study, we examined the in vivo osteogenic differentiation of human embryoid bodies (hEBs) by using an injectable in situ-forming hydrogel. A solution containing MPEG-b-(polycaprolactone-ran-polylactide) (MCL) and hEBs was easily prepared at room temperature. The MCL solution with hEBs and osteogenic factors was injected into nude mice and developed into in situ-forming hydrogels at the injection sites; these hydrogels maintained their shape even after 12 weeks in vivo, thereby indicat...

  13. In situ macromolecular crystallography using microbeams.

    Axford, Danny; Owen, Robin L; Aishima, Jun; Foadi, James; Morgan, Ann W; Robinson, James I; Nettleship, Joanne E; Owens, Raymond J; Moraes, Isabel; Fry, Elizabeth E; Grimes, Jonathan M; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S; Stuart, David I; Evans, Gwyndaf

    2012-05-01

    Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams. PMID:22525757

  14. Oil companies push in-situ recovery

    Possibly, a third Athabaska tar-sand plant using surface mining will be built in the 1980's, but future development beyond that point will probably depend on in-situ recovery. The discussion of in-situ recovery focusses on the effect it will have on the Canadian chemical industry, for example, the market for sodium hydroxide. To obtain the highest yields of oil from bitumen, an external source of hydrogen is necessary; for example Syncrude imports natural gas to make hydrogen for desulphurization. Gasification of coal is a possible source of hydrogen. Research on hydrocracking is progressing. Use of a prototype CANDU OCR reactor to raise the hot steam necessary for in-situ recovery has been suggested. Venezuela is interested in Canadian upgrading technology. (N.D.H.)

  15. In-situ vitrification of waste materials

    A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed. 7 figs

  16. In situ lithotripsy of ureteral calculi

    Over 7,000 kidneys and ureters have been treated with lithotripsy at the authors institution. Included among this group were 541 ureters containing single calculi that were treated in situ after retrograde manipulations had failed. One hundred thirty-five (25%) of these calculi were located in the distal ureter, below the superior border of the SI joint. The remainder were located in the middle or upper ureter. All but one of these calculi were successfully treated with lithotripsy and combined radiologic and urologic interventions. The number and type of interventions have been examined. In situ lithotripsy of ureteral calculi after unsuccessful retrograde manipulation has been shown to be feasible

  17. In-situ vitrification of waste materials

    Powell, James R. (Shoreham, NY); Reich, Morris (Kew Gardens Hills, NY); Barletta, Robert (Wading River, NY)

    1997-11-14

    A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed.

  18. In-situ observation of ettringite crystals

    Komatsu, Ryuichi; Mizukoshi, Norihiro; Makida, Koji; Tsukamoto, Katsuo

    2009-01-01

    In-situ observation of growing ettringite crystals in solution has been carried out and the morphology change of ettringite has been investigated under various conditions. In particular, the acceleration behavior of ettringite growth in the presence of calcite, the cause of which is not yet understood, is examined. Spherulite with calcite in its core is formed first followed by the generation of acicular crystals. Compared with the in-situ observation result of crystal growth in a solution with no calcite, the effect of added calcite can be explained as a decrease in the activation energy of nucleation for ettringite around calcite.

  19. In situ monitoring of gas emissions

    Classical extraction apparatuses for gaseous effluents analysis require important maintenance costs. A new in situ system for flue gas monitoring has been developed by the Californian Air Instruments and Measurements Inc. society and installed at the Red Wing refuse-fueled power plant in Minnesota. This system allows the in situ quantitative analysis of carbon monoxide and dioxide effluents using a self calibrating infrared spectrometer. This paper describes the numerous advantages and the maintenance costs reduction provided by this system. (J.S.). 2 photos

  20. In situ soil remediation using electrokinetics

    Electrokinetics is emerging as a promising technology for in situ soil remediation. This technique is especially attractive for Superfund sites and government operations which contain large volumes of contaminated soil. The approach uses an applied electric field to induce transport of both radioactive and hazardous waste ions in soil. The transport mechanisms include electroosmosis, electromigration, and electrophoresis. The feasibility of using electrokinetics to move radioactive 137Cs and 60Co at the Hanford Site in Richland, Washington, is discussed. A closed cell is used to provide in situ measurements of 137Cs and 60Co movement in Hanford soil. Preliminary results of ionic movement, along with the corresponding current response, are presented

  1. In situ ply strengths - An initial assessment

    Chamis, C. C.; Sullivan, T. L.

    1978-01-01

    The in situ ply strengths in several composites were calculated using a computational procedure developed for this purpose. Laminate fracture data for appropriate low modulus and high modulus fiber composites were used in the laminate analysis in conjunction with the method of least squares. The laminate fracture data were obtained from tests on Modmor-I graphite/epoxy, AS-graphite/epoxy, boron/epoxy and E-glass/epoxy. The results obtained show that the calculated in situ ply strengths can be considerably different from those measured in unidirectional composites, especially the transverse strengths and those in angleplied laminates with transply cracks.

  2. In situ bioremediation of trichloroethylene-contaminated water by a resting-cell methanotrophic microbial filter

    The Lawrence Livermore National Laboratory is testing and developing an in situ microbial filter technology for remediating migrating subsurface plumes contaminated with low concentrations of trichloroethylene (TCE). Their current focus is the establishment of a replenishable bioactive zone (catalytic filter) along expanding plume boundaries by the Injection of a representative methanotrophic bacterium, Methylosinus trichosporium OB3b. We have successfully demonstrated this microbial filter strategy using emplaced, attached resting cells (no methane additions) in a 1.1-m flow-through test bed loaded with water-saturated sand. Two separate 24 h pulses of TCE (109 ppb and 85 ppb), one week apart, were pumped through the system at a flow velocity of 1.5 cm/h; no TCE (<0.5 ppb) was detected on the downstream side of the microbial filter. Subsequent excavation of the wet sand confirmed the existence of a TCE-bioactive zone 19 days after it had been created. An enhanced longevity of the cellular, soluble-form methane monooxygenase produced by this methanotroph Is a result of our laboratory bioreactor culturing conditions. Additional experiments with cells in sealed vials and emplaced in the 1.1-m test bed yielded a high resting-cell finite TCE biotransformation capacity of ∼ 0.25 mg per mg of bacteria; this is suitable for a planned sand-filled trench field demonstration at a Lawrence Livermore National Laboratory site

  3. Aquifer restoration at in-situ leach uranium mines: evidence for natural restoration processes

    Pacific Northwest Laboratory conducted experiments with aquifer sediments and leaching solution (lixiviant) from an in-situ leach uranium mine. The data from these laboratory experiments and information on the normal distribution of elements associated with roll-front uranium deposits provide evidence that natural processes can enhance restoration of aquifers affected by leach mining. Our experiments show that the concentration of uranium (U) in solution can decrease at least an order of magnitude (from 50 to less than 5 ppM U) due to reactions between the lixiviant and sediment, and that a uranium solid, possibly amorphous uranium dioxide, (UO2), can limit the concentration of uranium in a solution in contact with reduced sediment. The concentrations of As, Se, and Mo in an oxidizing lixiviant should also decrease as a result of redox and precipitation reactions between the solution and sediment. The lixiviant concentrations of major anions (chloride and sulfate) other than carbonate were not affected by short-term (less than one week) contact with the aquifer sediments. This is also true of the total dissolved solids level of the solution. Consequently, we recommend that these solution parameters be used as indicators of an excursion of leaching solution from the leach field. Our experiments have shown that natural aquifer processes can affect the solution concentration of certain constituents. This effect should be considered when guidelines for aquifer restoration are established

  4. Accelerated in situ bioremediation of groundwater

    Truex, M.J.; Hooker, B.S.; Anderson, D.B.

    1996-07-01

    In situ bioremediation, as applied in this project, is based on the principal of biostimulation: supplying nutrients to indigenous microbes to stimulate their metabolic activity and subsequent degradation of contaminants. Typically, a network of injection and extraction wells are used to recirculate groundwater into which amendments are added and distributed within the aquifer. The objective of the in situ process is to create in the aquifer a microbially active zone that maximizes contaminant destruction while controlling the distribution of microbial growth. It is important to control microbial growth to avoid plugging the aquifer near the injection well and to establish and sustain maximum treatment zones for each injection well. Figure I illustrates this concept for in situ bioremediation. The technology described herein is innovative in its use of the computer-based Accelerated Bioremediation Design Tool (ABDT) to aid in selecting appropriate system designs and to determine optimal operating strategies. In addition, numerical simulations within the design tool proved to be valuable during remediation operations to determine appropriate changes in the` operating strategy as the bioremediation process progressed. This is particularly important because in situ bioremediation is not a steady- state process, and corrective actions to operating parameters are typically needed to maintain both rapid destruction rates and hydraulic containment.

  5. Two cases of subungual melanoma in situ.

    Imakado, Sumihisa; Sato, Hiroyuki; Hamada, Kazutoshi

    2008-11-01

    Melanonychia, which is characterized by brown or black pigmentation within the nail plate, includes heterogeneous conditions such as pigmented nevus, subungual melanoma and lentigo. We treated two cases of subungual melanoma in situ. One case was a 58-year-old woman who suffered from a malignant melanoma in situ of the left third fingernail, who had also suffered from melanonychia of the fingers for more than 30 years. She had a past history of carcinoma of the uterine cervix. The other patient was a 42-year-old man, who suffered from a malignant melanoma in situ of the right fifth fingernail. He had a past history of carcinoma of the stomach for which he had undergone surgery 2 years earlier. Both cases were accompanied by Hutchinson's sign on the fingertip skin, and the presence of this sign led to the correct diagnosis of subungual melanoma in situ. Judging from previously reported cases, it is unlikely that patients with malignant melanoma have an increased risk of carcinoma of the uterine cervix or of the stomach. PMID:19120774

  6. Refueling with In-Situ Produced Propellants

    Chato, David J.

    2014-01-01

    In-situ produced propellants have been identified in many architecture studies as key to implementing feasible chemical propulsion missions to destinations beyond lunar orbit. Some of the more noteworthy ones include: launching from Mars to return to Earth (either direct from the surface, or via an orbital rendezvous); using the Earth-Moon Lagrange point as a place to refuel Mars transfer stages with Lunar surface produced propellants; and using Mars Moon Phobos as a place to produce propellants for descent and ascent stages bound for the Mars surface. However successful implementation of these strategies require an ability to successfully transfer propellants from the in-situ production equipment into the propellant tankage of the rocket stage used to move to the desired location. In many circumstances the most desirable location for this transfer to occur is in the low-gravity environment of space. In support of low earth orbit propellant depot concepts, extensive studies have been conducted on transferring propellants in-space. Most of these propellant transfer techniques will be applicable to low gravity operations in other locations. Even ground-based transfer operations on the Moon, Mars, and especially Phobos could benefit from the propellant conserving techniques used for depot refueling. This paper will review the literature of in-situ propellants and refueling to: assess the performance benefits of the use in-situ propellants for mission concepts; review the parallels with propellant depot efforts; assess the progress of the techniques required; and provide recommendations for future research.

  7. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  8. In Situ Flash Pyrolysis of Straw

    Bech, Niels

    In-Situ Flash Pyrolysis of Straw Ph.D. dissertation by Niels Bech Submitted: April 2007. Supervisors: Professor Kim Dam-Johansen, Associate Professor Peter Arendt Jensen Erfaringerne med forbrænding af halm opnået gennem et årti har vist, at en proces der kan koncentrere energien på marken, fjerne...

  9. In Situ TEM Creation of Nanowire Devices

    Alam, Sardar Bilal

    Integration of silicon nanowires (SiNWs) as active components in devices requires that desired mechanical, thermal and electrical interfaces can be established between the nanoscale geometry of the SiNW and the microscale architecture of the device. In situ transmission electron microscopy (TEM),...

  10. In Situ Cleanable Alternative HEPA Filter Media

    The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of Energy's Hazardous Facilities'', found that conventional glass fiber HEPA filters are structurally weak and easily damaged by water or fire. The structurally stronger sintered metal and ceramic filters would reduce the potential of a catastrophic HEPA filter failure due to filter media breakthrough in the process ventilation system. An in situ regenerable system may also find application in recovering nuclear materials, such as plutonium, collected on glove box exhaust HEPA filters. This innovative approach of the in situ regenerative filtration system may be a significant improvement upon the shortfalls of conventional disposable HEPA filters

  11. In Situ Cleanable Alternative HEPA Filter Media

    Adamson, D. J.; Terry, M. T.

    2002-02-28

    The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of Energy's Hazardous Facilities'', found that conventional glass fiber HEPA filters are structurally weak and easily damaged by water or fire. The structurally stronger sintered metal and ceramic filters would reduce the potential of a catastrophic HEPA filter failure due to filter media breakthrough in the process ventilation system. An in situ regenerable system may also find application in recovering nuclear materials, such as plutonium, collected on glove box exhaust HEPA filters. This innovative approach of the in situ regenerative filtration system may be a significant improvement upon the shortfalls of conventional disposable HEPA filters.

  12. In Situ Remediation Integrated Program: Technology summary

    The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces, in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP intends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years. ISR IP is an applied research and development program broadly addressing known DOE environmental restoration needs. Analysis of a sample of 334 representative sites by the Office of Environmental Restoration has shown how many sites are amenable to in situ remediation: containment--243 sites; manipulation--244 sites; bioremediation--154 sites; and physical/chemical methods--236 sites. This needs assessment is focused on near-term restoration problems (FY93--FY99). Many other remediations will be required in the next century. The major focus of the ISR EP is on the long term development of permanent solutions to these problems. Current needs for interim actions to protect human health and the environment are also being addressed

  13. In Situ SERS Monitoring of Photochemistry within a Nanojunction Reactor

    2013-01-01

    We demonstrate a powerful SERS-nanoreactor concept composed of self-assembled gold nanoparticles (AuNP) linked by the sub-nm macrocycle cucurbit[n]uril (CB[n]). The CB[n] functions simultaneously as a nanoscale reaction vessel, sequestering and templating a photoreaction within, and also as a powerful SERS-transducer through the large field enhancements generated within the nanojunctions that CB[n]s define. Through the enhanced Raman fingerprint, the real-time SERS-monitoring of a prototypical stilbene photoreaction is demonstrated. By choosing the appropriate CB[n] nanoreactor, selective photoisomerism or photodimerization is monitored in situ from within the AuNP-CB[n] nanogap. PMID:24188432

  14. A Week in Creativity

    Jane Piirto

    2012-01-01

    The author recounts a week in October, describing her teaching, writing, thinking, mail, and other activities that relate to her professional and personal work on creativity. This personal creative nonfiction piece also contains poetry and references to her books and lectures. The author chose this form in order to emphasize the autobiographical nature of work in the area of creativity.

  15. At Least 39 Weeks

    Full Text Available ... 39 weeks 3:36 Stanford Prematurity Research Center Launch 3:25 Newborn care: Breastfeeding 3:48 Groundbreaking ... Frequently asked questions Peristats Nursing programs Prematurityprevention.org Product Catalog Get Involved Volunteer Volunteer leaders Team Youth ...

  16. At Least 39 Weeks

    Full Text Available ... premature birth The newborn intensive care unit (NICU) Birth defects & other health conditions Loss & grief Tools & Resources Frequently asked health questions Ask our health experts Calculating your due date Ovulation calendar 39 weeks is best Order bereavement materials News Moms Need Blog News & Media ...

  17. International Week '13

    Kirchhübel, Nicola; Fattoul, Soufian

    2012-01-01

    This project deals with planning the event International Week 2013 - to raise awareness about the international standing of RUC and what it has to offer both international and Danish students. The project features a discussion of potential collaborative partners that could be involved, the marketing strategies that could be used, and the mechanics of achieving the end goal.

  18. Osteogenic efficiency of in situ gelling poloxamine systems with and without bone morphogenetic protein-2

    A Rey-Rico

    2011-04-01

    Full Text Available In situ gelling solutions for minimally invasive local application of bone growth factors are attracting increasing attention as efficient and patient-friendly alternative to bone grafts and solid scaffolds for repairing bone defects. Poloxamines, i.e., X-shaped poly(ethylene oxide-poly(propylene oxide block copolymers with an ethylenediamine core (Tetronic®, were evaluated both as an active osteogenic component and as a vehicle for rhBMP-2 injectable implants. After cytotoxicity screening of various poloxamine varieties, Tetronic 908, 1107, 1301 and 1307 solutions were chosen as the most cytocompatible and their sol-to-gel transitions were rheologically characterized. Viscoelastic gels, formed at 37 ºC, sustained protein release under physiological-like conditions. Formulations of rhBMP-2 led to differentiation of mesenchymal stem cells to osteoblasts, quantified as alkaline phosphatase activity with a maximum at day 7, and to mineralized nodules. Interestingly, poloxamine solely gels led to an initial proliferation of the mesenchymal stem cells (first week, followed by differentiation to osteoblasts (second to third week. Histochemical analysis revealed that Tetronic 908 is only osteoinductive; Tetronic 1107 is mostly osteoinductive, although its use leads to a minor differentiation to adipocytes; Tetronic 1307, solely or loaded with rhBMP-2, causes differentiation of both osteoblasts and adipocytes. Enhanced expression levels of CBFA-1 and collagen type I were observed for Tetronic 908, 1107 and 1307, both solely and combined with rhBMP-2. The intrinsic osteogenic activity of poloxamines (not observed for Pluronic F127 offers novel perspectives for bone regeneration using minimally invasive procedures (i.e., injectable scaffolds and overcoming the safety and the cost/effectiveness concerns associated with large scale clinical use of recombinant growth factors.

  19. Osteogenic potential of in situ TiO2 nanowire surfaces formed by thermal oxidation of titanium alloy substrate

    Highlights: • In situ titanium dioxide (TiO2) nanowire surface structures were fabricated on Ti-6Al-4V substrate using thermal oxidation. • Initial cell adhesion, cell proliferation, cell differentiation, cell mineralization, and osteogenic related gene expression of primary human osteoblasts were examined on the TiO2 nanowire surfaces. • TiO2 nanowire surfaces showed enhanced osteogenic potential as compared to the planar surface. - Abstract: Titanium dioxide (TiO2) nanowire surface structures were fabricated in situ by a thermal oxidation process, and their ability to enhance the osteogenic potential of primary osteoblasts was investigated. Human osteoblasts were isolated from nasal bone and cultured on a TiO2 nanowires coated substrate to assess its in vitro cellular interaction. Bare featureless Ti-6Al-4V substrate was used as a control surface. Initial cell adhesion, cell proliferation, cell differentiation, cell mineralization, and osteogenic related gene expression were examined on the TiO2 nanowire surfaces as compared to the control surfaces after 2 weeks of culturing. Cell adhesion and cell proliferation were assayed by field emission scanning electron microscope (FESEM) and Alamar Blue reduction assay, respectively. The nanowire surfaces promoted better cell adhesion and spreading than the control surface, as well as leading to higher cell proliferation. Our results showed that osteoblasts grown onto the TiO2 nanowire surfaces displayed significantly higher production levels of alkaline phosphatase (ALP), extracellular (ECM) mineralization and genes expression of runt-related transcription factor (Runx2), bone sialoprotein (BSP), ostoepontin (OPN) and osteocalcin (OCN) compared to the control surfaces. This suggests the potential use of such surface modification on Ti-6Al-4V substrates as a promising means to improve the osteointegration of titanium based implants

  20. Osteogenic potential of in situ TiO{sub 2} nanowire surfaces formed by thermal oxidation of titanium alloy substrate

    Tan, A.W. [Department of Biomedical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Ismail, R.; Chua, K.H. [Department of Physiology, Faculty of Medicine, National University of Malaysia, 50300 Kuala Lumpur (Malaysia); Ahmad, R. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Akbar, S.A. [Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210 (United States); Pingguan-Murphy, B., E-mail: bpingguan@um.edu.my [Department of Biomedical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-11-30

    Highlights: • In situ titanium dioxide (TiO{sub 2}) nanowire surface structures were fabricated on Ti-6Al-4V substrate using thermal oxidation. • Initial cell adhesion, cell proliferation, cell differentiation, cell mineralization, and osteogenic related gene expression of primary human osteoblasts were examined on the TiO{sub 2} nanowire surfaces. • TiO{sub 2} nanowire surfaces showed enhanced osteogenic potential as compared to the planar surface. - Abstract: Titanium dioxide (TiO{sub 2}) nanowire surface structures were fabricated in situ by a thermal oxidation process, and their ability to enhance the osteogenic potential of primary osteoblasts was investigated. Human osteoblasts were isolated from nasal bone and cultured on a TiO{sub 2} nanowires coated substrate to assess its in vitro cellular interaction. Bare featureless Ti-6Al-4V substrate was used as a control surface. Initial cell adhesion, cell proliferation, cell differentiation, cell mineralization, and osteogenic related gene expression were examined on the TiO{sub 2} nanowire surfaces as compared to the control surfaces after 2 weeks of culturing. Cell adhesion and cell proliferation were assayed by field emission scanning electron microscope (FESEM) and Alamar Blue reduction assay, respectively. The nanowire surfaces promoted better cell adhesion and spreading than the control surface, as well as leading to higher cell proliferation. Our results showed that osteoblasts grown onto the TiO{sub 2} nanowire surfaces displayed significantly higher production levels of alkaline phosphatase (ALP), extracellular (ECM) mineralization and genes expression of runt-related transcription factor (Runx2), bone sialoprotein (BSP), ostoepontin (OPN) and osteocalcin (OCN) compared to the control surfaces. This suggests the potential use of such surface modification on Ti-6Al-4V substrates as a promising means to improve the osteointegration of titanium based implants.

  1. In Vivo Osteogenic Differentiation of Human Embryoid Bodies in an Injectable in Situ-Forming Hydrogel

    Moon Suk Kim

    2013-07-01

    Full Text Available In this study, we examined the in vivo osteogenic differentiation of human embryoid bodies (hEBs by using an injectable in situ-forming hydrogel. A solution containing MPEG-b-(polycaprolactone-ran-polylactide (MCL and hEBs was easily prepared at room temperature. The MCL solution with hEBs and osteogenic factors was injected into nude mice and developed into in situ-forming hydrogels at the injection sites; these hydrogels maintained their shape even after 12 weeks in vivo, thereby indicating that the in situ-forming MCL hydrogel was a suitable scaffold for hEBs. The in vivo osteogenic differentiation was observed only in the in situ gel-forming MCL hydrogel in the presence of hEBs and osteogenic factors. In conclusion, this preliminary study suggests that hEBs and osteogenic factors embedded in an in situ-forming MCL hydrogel may provide numerous benefits as a noninvasive alternative for allogeneic tissue engineering applications.

  2. The use of hydraulic fracturing to enhance in situ bioremediation

    Bioremediation was determined to be a viable method of degrading the hydrocarbon contaminants at a fuel distribution and storage facility in Dayton, Ohio. Laboratory tests done by the on-site contractor indicated that percolating water containing oxygen and nutrients through the soil would result in biodegradation of the contaminants. The site is underlain by silty clay till of relatively low hydraulic conductivity, so conventional methods of delivery were expected to result in either slow rates of percolation, and thus slow rates of remediation, or excessive drilling costs. Therefore, the site was selected as a candidate for hydraulic fracturing, a technique of creating high permeability channel ways in tight soils. 1 fig

  3. At Least 39 Weeks

    Full Text Available ... Newborn care: Crying 2:14 39 Weeks Study: Healthy Babies Are Worth the Wait 2:05 Don't You Dare: Tips for Preconception 9:31 North Carolina ... make a difference and let your friends know you are helping end premature birth. Become the first of your ... babies. We help moms have full-term pregnancies and healthy babies. If something goes wrong, we offer information ...

  4. The determination of the in situ structure by nuclear spin contrast variation

    Polarized neutron scattering from polarized nuclear spins in hydrogenous substances opens a new way of contrast variation. The enhanced contrast due to proton spin polarization was used for the in situ structure determination of tRNA of the functional complex of the E.coli ribosome

  5. The determination of the in situ structure by nuclear spin contrast variation

    Stuhrmann, H.B. [GKSS Forschungszentrum, Geesthacht (Germany); Nierhaus, K.H. [Max-Planch-Institut fuer Molekulare Genetik, Berlin (Germany)

    1994-12-31

    Polarized neutron scattering from polarized nuclear spins in hydrogenous substances opens a new way of contrast variation. The enhanced contrast due to proton spin polarization was used for the in situ structure determination of tRNA of the functional complex of the E.coli ribosome.

  6. Inherently safe in situ uranium recovery

    Krumhansl, James L; Brady, Patrick V

    2014-04-29

    An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

  7. In situ bioremediation of Hanford groundwater

    Liquid wastes containing radioactive, hazardous, and regulated chemicals have been generated throughout the 40+ years of operations at the US Department of Energy's (DOE) Hanford Site. Some of these wastes were discharged to the soil column and many of the waste components, including nitrate, carbon tetrachloride (CCl4), and several radionuclides, have been detected in the Hanford groundwater. Current DOE policy prohibits the disposal of contaminated liquids directly to the environment, and remediation of existing contaminated groundwaters may be required. In situ bioremediation is one technology currently being developed at Hanford to meet the need for cost effective technologies to clean groundwater contaminated with CCl4, nitrate, and other organic and inorganic contaminants. This paper focuses on the latest results of an on going effort to develop effective in situ remediation strategies through the use of predictive simulations

  8. Ductal carcinoma in situ: a challenging disease

    Sevilay Altintas; Manon T. Huizing; Eric Van Marck; Vermorken, Jan B; Tjalma, Wiebren A.

    2011-01-01

    Ductal carcinoma in situ (DCIS) represents a heterogenous group of lesions with variable malignant potential. Although it is clearly pre-invasive, not all lesions progress to an invasive malignant disease. The significant increase in the frequency of diagnosis is the result of both widespread use of screening mammography and better recognition among pathologists. Treatment is controversial, but for several decades total mastectomy has been considered as the appropriate treatment. The tendency...

  9. In situ determination of salinity by PGNAA

    Borsaru, M. [CSIRO Exploration and Mining, P.O. Box 883, Kenmore, Qld. 4069 (Australia)]. E-mail: mihai.borsaru@csiro.au; Smith, C. [CSIRO Exploration and Mining, P.O. Box 883, Kenmore, Qld. 4069 (Australia); Merritt, J. [Anglo Coal (Capcoal Management) Pty. Ltd., PMB, Middlemount. Qld. 4746 (Australia); Aizawa, T. [Suncoh Consultants Co., Ltd, 1-8-9, Kameido, Koto-Ku, Tokyo, 136-8522 (Japan); Rojc, A. [CSIRO Exploration and Mining, P.O. Box 883, Kenmore, Qld. 4069 (Australia)

    2006-05-15

    Salinity is a very important environmental issue all around the world. In many cases salinity was produced from human activities like farming and mining. Different soluble salts contribute to salinity, however, NaCl is the most common salt producing salinity. This work deals with the application of the prompt gamma neutron activation analysis (PGNAA) technique for in situ determination of salinity. The technique is based on the measurement of chlorine, a component of the common salt, by PGNAA.

  10. In-Situ Generated Active Substances

    Van de Plassche, Erik

    2015-01-01

    Biocidal active substances are called in-situ generated active substances if they are generated from one or more precursors at the place of use, like active chlorine generated from sodium chloride by electrolysis, active bromine generated from sodium bromide and sodium hypochlorite and hydrogen peroxide generated from sodium percarbonate by dissolution in water. The approval of these substances in the European Union (EU) requires evaluation of the generated active substance and of the precurs...

  11. In situ health monitoring of piezoelectric sensors

    Jensen, Scott L. (Inventor); Drouant, George J. (Inventor)

    2013-01-01

    An in situ health monitoring apparatus may include an exciter circuit that applies a pulse to a piezoelectric transducer and a data processing system that determines the piezoelectric transducer's dynamic response to the first pulse. The dynamic response can be used to evaluate the operating range, health, and as-mounted resonance frequency of the transducer, as well as the strength of a coupling between the transducer and a structure and the health of the structure.

  12. Femtosecond laser in laser in situ keratomileusis

    Salomo, Marcella Q.; Wilson, Steven E.

    2010-01-01

    Flap creation is a critical step in laser in situ keratomileusis (LASIK). Efforts to improve the safety and predictability of the lamellar incision have fostered the development of femtosecond lasers. Several advantages of the femtosecond laser over mechanical microkeratomes have been reported in LASIK surgery. In this article, we review common considerations in management and complications of this step in femtosecond laserLASIK and concentrate primarily on the IntraLase laser because most p...

  13. In situ ion irradiation of zirconium carbide

    Ulmer, Christopher J.; Motta, Arthur T.; Kirk, Mark A.

    2015-11-01

    Zirconium carbide (ZrC) is a candidate material for use in one of the layers of TRISO coated fuel particles to be used in the Generation IV high-temperature, gas-cooled reactor, and thus it is necessary to study the effects of radiation damage on its structure. The microstructural evolution of ZrCx under irradiation was studied in situ using the Intermediate Voltage Electron Microscope (IVEM) at Argonne National Laboratory. Samples of nominal stoichiometries ZrC0.8 and ZrC0.9 were irradiated in situ using 1 MeV Kr2+ ions at various irradiation temperatures (T = 20 K-1073 K). In situ experiments made it possible to continuously follow the evolution of the microstructure during irradiation using diffraction contrast imaging. Images and diffraction patterns were systematically recorded at selected dose points. After a threshold dose during irradiations conducted at room temperature and below, black-dot defects were observed which accumulated until saturation. Once created, the defect clusters did not move or get destroyed during irradiation so that at the final dose the low temperature microstructure consisted only of a saturation density of small defect clusters. No long-range migration of the visible defects or dynamic defect creation and elimination were observed during irradiation, but some coarsening of the microstructure with the formation of dislocation loops was observed at higher temperatures. The irradiated microstructure was found to be only weakly dependent on the stoichiometry.

  14. In situ diesel fuel bioremediation: A case history

    As a result of a ruptured fuel line, the study site had diesel fuel soil contamination and free product more than 2 ft (0.75 m) thick on the groundwater surface. Diesel fuel, which is composed of a high percentage of nonvolatile compounds, has proven difficult to remediate using conventional extraction remediation techniques. A number of remedial alternatives were reviewed, and the patented in situ biodegradation BioSpargeSM technology was selected for the site and performed under license by a specialty contractor. BioSpargeSM is a field-proven closed-loop (no vapor emissions) system that supplies a continuous, steady supply of oxygen, moisture, and additional heat to enhance microorganism activity. The system injects an enriched airstream beneath the groundwater surface elevation and/or within the contaminant plume and removes residual vapors from vadose zone soil within and above the contaminant plume. The technology has no air discharge, which is critical in areas where strict air discharge regulations apply. The focus of this paper is the viability of in situ biodegradation as an effective remediation alternative for reducing nonvolatile petroleum products

  15. Software Tools for In-Situ Documentation of Built Heritage

    Smars, P.

    2013-07-01

    The paper presents open source software tools developed by the author to facilitate in-situ documentation of architectural and archæological heritage. The design choices are exposed and related to a general issue in conservation and documentation: taking decisions about a valuable object under threat . The questions of level of objectivity is central to the three steps of this process. It is our belief that in-situ documentation has to be favoured in this demanding context, full of potential discoveries. The very powerful surveying techniques in rapid development nowadays enhance our vision but often tend to bring back a critical part of the documentation process to the office. The software presented facilitate a direct treatment of the data on the site. Emphasis is given to flexibility, interoperability and simplicity. Key features of the software are listed and illustrated with examples (3D model of Gothic vaults, analysis of the shape of a column, deformation of a wall, direct interaction with AutoCAD).

  16. Laser deposition of in situ Ti-TiB composites

    Banerjee, R.; Collins, P.C.; Fraser, H.L. [Department of Mat. Science and Eng., The Ohio State University, Columbus, OH 43210 (United States)

    2002-11-01

    Due to their enhanced mechanical properties and potentially wide applicability, there is considerable interest in the development of metal-matrix composites consisting of titanium borides in a titanium alloy matrix. Despite the development of a variety of different processing routes for these composites, there are relatively few ones capable of processing a fully dense, near-net shape component with a relatively fine dispersion of boride precipitates. This paper will discuss the in situ laser deposition of Ti-TiB composites using the laser engineered net-shaping (LENS{sup TM}) process from a blend of elemental titanium (or titanium alloy) and boron powders. The microstructure of the LENS{sup TM} deposited Ti-TiB composite has been compared with that of a conventionally cast in situ composite of the same composition. The conventionally cast composite exhibits a significantly coarser scale microstructure. Thus, the ability to produce a fine dispersion of TiB precipitates in dense Ti-TiB composites of near-net shape using LENS{sup TM} processing can be attributed to the rapid solidification effects during such processing. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  17. IN SITU FIELD TESTING OF PROCESSES

    J.S.Y. YANG

    2004-11-08

    The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes REV 02. The scientific analysis of data for inputs to model calibration and validation as documented in REV 02 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in this scientific analysis report and associated UZ flow and transport model reports. No additional testing or analyses were performed as part of this revision. The list of relevant acceptance criteria is provided by ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654]), Table 3-1. Additional deviations from the TWP regarding the features, events, and processes (FEPs) list are discussed in Section 1.3. Documentation in this report includes descriptions of how, and under what conditions, the tests were conducted. The descriptions and analyses provide data useful for refining and confirming the understanding of flow, drift seepage, and transport processes in the UZ. The UZ testing activities included measurement of permeability distribution, quantification of the seepage of water into the drifts, evaluation of fracture-matrix interaction, study of flow along faults, testing of flow and transport between drifts, characterization of hydrologic heterogeneity along drifts, estimation of drying effects on the rock surrounding the drifts due to ventilation, monitoring of moisture conditions in open and sealed drifts, and determination of the degree of minimum construction water migration below drift. These field tests were conducted in two underground drifts at Yucca Mountain, the Exploratory Studies Facility (ESF) drift, and the cross-drift for Enhanced Characterization of the Repository Block (ECRB), as described in Section 1.2. Samples collected in boreholes and underground drifts have been used for additional hydrochemical and isotopic analyses for additional understanding of the UZ setting. The UZ transport tests conducted at the nearby Busted Butte site (see Figure 1-4) are also described in this scientific analysis report.

  18. IN SITU FIELD TESTING OF PROCESSES

    The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes2. The scientific analysis of data for inputs to model calibration and validation as documented in2 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in this scientific analysis report and associated UZ flow and transport model reports. No additional testing or analyses were performed as part of this revision. The list of relevant acceptance criteria is provided by ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654]), Table 3-1. Additional deviations from the TWP regarding the features, events, and processes (FEPs) list are discussed in Section 1.3. Documentation in this report includes descriptions of how, and under what conditions, the tests were conducted. The descriptions and analyses provide data useful for refining and confirming the understanding of flow, drift seepage, and transport processes in the UZ. The UZ testing activities included measurement of permeability distribution, quantification of the seepage of water into the drifts, evaluation of fracture-matrix interaction, study of flow along faults, testing of flow and transport between drifts, characterization of hydrologic heterogeneity along drifts, estimation of drying effects on the rock surrounding the drifts due to ventilation, monitoring of moisture conditions in open and sealed drifts, and determination of the degree of minimum construction water migration below drift. These field tests were conducted in two underground drifts at Yucca Mountain, the Exploratory Studies Facility (ESF) drift, and the cross-drift for Enhanced Characterization of the Repository Block (ECRB), as described in Section 1.2. Samples collected in boreholes and underground drifts have been used for additional hydrochemical and isotopic analyses for additional understanding of the UZ setting. The UZ transport tests conducted at the nearby Busted Butte site (see Figure 1-4) are also described in this scientific analysis report

  19. In-Situ Nitrogen Doping of the TiO2 Photocatalyst Deposited by PEALD for Visible Light Activity

    In this paper, an N-doped titanium oxide (TiO2) photocatalyst is deposited by a plasma-enhanced atomic layer deposition (PEALD) system through the in-situ doping method. X-ray photoelectron spectroscopy (XPS) analysis indicates that substitutional nitrogen atoms (∼395.9 eV) with 1 atom% are effectively doped into TiO2 films. UV-VIS spectrometry shows that the in-situ nitrogen doping method indeed enhances the visible-activity of TiO2 films in the 425–550 nm range, and the results of the performance tests of the N-doped TiO2 films also imply that the photocatalysis activity is improved by in-situ doping. The in-situ doping mechanism of the N-doped TiO2 film is suggested according to the XPS results and the typical atomic layer deposition process

  20. CERN safety week

    DG Unit

    2009-01-01

    Following an increase in the number of accidents in 2008, the Safety Commission is organising a CERN safety week from 8 to 12 June for riders of bicycles, scooters and motorbikes. We invite you to take part in the programme, which will be held in the Main Building (Bldg. 500) and will consist of an exhibition, organised events and hands-on activities, including demonstrations of emergency braking, a driving simulator, simulation of what it feels like to drive under the influence of alcohol, demonstrations by the Fire Brigade, video projections, etc. There will also be a number of prizes to be won. Please sign up via your DSO.

  1. In-Situ Remediation Approaches for the Management of Contaminated Sites: A Comprehensive Overview.

    Kuppusamy, Saranya; Palanisami, Thavamani; Megharaj, Mallavarapu; Venkateswarlu, Kadiyala; Naidu, Ravi

    2016-01-01

    Though several in-situ treatment methods exist to remediate polluted sites, selecting an appropriate site-specific remediation technology is challenging and is critical for successful clean up of polluted sites. Hence, a comprehensive overview of all the available remediation technologies to date is necessary to choose the right technology for an anticipated pollutant. This review has critically evaluated the (i) technological profile of existing in-situ remediation approaches for priority and emerging pollutants, (ii) recent innovative technologies for on-site pollutant remediation, and (iii) current challenges as well as future prospects for developing innovative approaches to enhance the efficacy of remediation at contaminated sites. PMID:26423073

  2. 30 CFR 828.11 - In situ processing: Performance standards.

    2010-07-01

    ... in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing... processing activities shall submit for approval as part of the application for permit under 30 CFR 785.22... 30 Mineral Resources 3 2010-07-01 2010-07-01 false In situ processing: Performance standards....

  3. ATLAS overview week highlights

    D. Froidevaux

    2005-01-01

    A warm and early October afternoon saw the beginning of the 2005 ATLAS overview week, which took place Rue de La Montagne Sainte-Geneviève in the heart of the Quartier Latin in Paris. All visitors had been warned many times by the ATLAS management and the organisers that the premises would be the subject of strict security clearance because of the "plan Vigipirate", which remains at some level of alert in all public buildings across France. The public building in question is now part of the Ministère de La Recherche, but used to host one of the so-called French "Grandes Ecoles", called l'Ecole Polytechnique (in France there is only one Ecole Polytechnique, whereas there are two in Switzerland) until the end of the seventies, a little while after it opened its doors also to women. In fact, the setting chosen for this ATLAS overview week by our hosts from LPNHE Paris has turned out to be ideal and the security was never an ordeal. For those seeing Paris for the first time, there we...

  4. In situ reacted rare-earth hexaaluminate interphases

    A novel in situ reaction between a ceria-doped zirconia interphase coating on Saphikon fibers and an outer alumina coating has resulted in the formation of oriented hexaaluminate platelets which can act as a low fracture energy interface barrier for crack deflection in oxide-oxide ceramic-matrix composites (CMCs). The reaction proceeds only in reducing environments where the reduction of the cerium and zirconium ions to their 3+ valent state causes a destabilization phenomenon consistent with previously reported findings. The diffusion of the cerium from the zirconia into solid solution with the alumina can stabilize the layered hexaaluminate structure. Preferred orientational growth of the hexaaluminate parallel to the coating interface was observed which is the required orientation for enhanced debonding at the fiber/matrix interface in long-fiber-reinforced CMCs

  5. In-situ groundwater remediation by selective colloid mobilization

    Seaman, John C. (New Ellenton, SC); Bertch, Paul M. (Aiken, SC)

    1998-01-01

    An in-situ groundwater remediation pump and treat technique effective for reclamation of aquifers that have been contaminated with a mixed, metal-containing waste, which promotes selective mobilization of metal oxide colloids with a cationic surfactant, preferably a quaternary alkylammonium surfactant, without significantly reducing formation permeability that often accompanies large-scale colloid dispersion, thus increasing the efficiency of the remediation effort by enhancing the capture of strongly sorbing contaminants associated with the oxide phases. The resulting suspension can be separated from the bulk solution with controlled pH adjustments to destabilize the oxide colloids, and a clear supernatant which results that can be recycled through the injection well without further waste treatment.

  6. Air-coupled acoustic thermography for in-situ evaluation

    Zalameda, Joseph N. (Inventor); Winfree, William P. (Inventor); Yost, William T. (Inventor)

    2010-01-01

    Acoustic thermography uses a housing configured for thermal, acoustic and infrared radiation shielding. For in-situ applications, the housing has an open side adapted to be sealingly coupled to a surface region of a structure such that an enclosed chamber filled with air is defined. One or more acoustic sources are positioned to direct acoustic waves through the air in the enclosed chamber and towards the surface region. To activate and control each acoustic source, a pulsed signal is applied thereto. An infrared imager focused on the surface region detects a thermal image of the surface region. A data capture device records the thermal image in synchronicity with each pulse of the pulsed signal such that a time series of thermal images is generated. For enhanced sensitivity and/or repeatability, sound and/or vibrations at the surface region can be used in feedback control of the pulsed signal applied to the acoustic sources.

  7. Radiation-induced autologous in situ tumor vaccines

    Radiation therapy (RT) has been used as a definitive treatment for many solid tumors. While tumoricidal properties of RT are instrumental for standard clinical application, irradiated tumors can potentially serve as a source of tumor antigens in vivo, where dying tumor cells would release tumor antigens and danger signals and serve as autologous in situ tumor vaccines. Using murine tumor models of prostate, metastatic lung cancer and melanoma, we have demonstrated evidence of radiation-enhanced tumor-specific immune response that resulted in improved primary tumor control and reduction in systemic metastasis and cure. We will discuss the immunogenic properties of RT and determine how immunotherapeutic approaches can synergize with RT in boosting immune cells cell function. (author)

  8. In situ electrical transport measurementof superconductive ultrathin films

    Liu, Can-Hua; Jia, Jin-Feng

    2015-11-01

    The discovery of an extraordinarily superconductive large energy gap in SrTiO3 supported single-layer FeSe films has recently initiated a great deal of research interests in surface-enhanced superconductivity and superconductive ultrathin films fabricated on crystal surfaces. On account of the instability of ultra-thin films in air, it is desirable to perform electrical transport measurement in ultra-high vaccum (UHV). Here we review the experimental techniques of in situ electrical transport measurement and their applications on superconductive ultrathin films. The work in SJTU was supported by the National Basic Research Program of China (Grant Nos. 2013CB921902 and 2011CB922200) and the National Natural Science Foundation of China (Grant Nos. 11227404, 11274228, 11521404, 11174199, and 11134008).

  9. In Situ Analysis of Nitrifying Biofilms as Determined by In Situ Hybridization and the Use of Microelectrodes

    Okabe, Satoshi; Satoh, Hisashi; Watanabe, Yoshimasa

    1999-01-01

    We investigated the in situ spatial organization of ammonia-oxidizing and nitrite-oxidizing bacteria in domestic wastewater biofilms and autotrophic nitrifying biofilms by using microsensors and fluorescent in situ hybridization (FISH) performed with 16S rRNA-targeted oligonucleotide probes. The combination of these techniques made it possible to relate in situ microbial activity directly to the occurrence of nitrifying bacterial populations. In situ hybridization revealed that bacteria belon...

  10. Development on device for lifting submersible pump in production well of in-situ leaching

    Aimed at the feature of pumping lixivium with submersible pump in in-situ leaching mine, the electro vehicle carried device for lifting submersible pump is developed. The device is simple in structure, easy to operation, stable in performance and reliable in safety. It is applied with perfect results in the field test of in-situ leaching of uranium in Xinjiang. In the practical application, compared with the ways of lifting submersible pump of manhandling and hoister, the device can greatly enhance operating efficiency, facilitates field multi-well operation (because it can come along car removing). The problem difficult of lifting submersible pump in the production well of in-situ leaching mine is solved

  11. In situ Raman spectroscopy for growth monitoring of vertically aligned multiwall carbon nanotubes in plasma reactor

    Labbaye, T.; Gaillard, M.; Lecas, T.; Kovacevic, E.; Boulmer-Leborgne, Ch.; Guimbretière, G. [GREMI, Université-CNRS, BP6744, 45067 Orléans Cedex 2 (France); Canizarès, A.; Raimboux, N.; Simon, P.; Ammar, M. R., E-mail: mohamed-ramzi.ammar@cnrs-orleans.fr [CNRS, CEMHTI UPR3079, Univ. Orléans, F-45071 Orléans Cedex 2 (France); Strunskus, T. [Institute of Material Science, Chritian-Albrechts-University of Kiel, D-24143 Kiel (Germany)

    2014-11-24

    Portable and highly sensitive Raman setup was associated with a plasma-enhanced chemical vapor deposition reactor enabling in situ growth monitoring of multi-wall carbon nanotubes despite the combination of huge working distance, high growth speed and process temperature and reactive plasma condition. Near Edge X-ray absorption fine structure spectroscopy was used for ex situ sample analysis as a complementary method to in situ Raman spectroscopy. The results confirmed the fact that the “alternating” method developed here can accurately be used for in situ Raman monitoring under reactive plasma condition. The original analytic tool can be of great importance to monitor the characteristics of these nanostructured materials and readily define the ultimate conditions for targeted results.

  12. In situ Raman spectroscopy for growth monitoring of vertically aligned multiwall carbon nanotubes in plasma reactor

    Portable and highly sensitive Raman setup was associated with a plasma-enhanced chemical vapor deposition reactor enabling in situ growth monitoring of multi-wall carbon nanotubes despite the combination of huge working distance, high growth speed and process temperature and reactive plasma condition. Near Edge X-ray absorption fine structure spectroscopy was used for ex situ sample analysis as a complementary method to in situ Raman spectroscopy. The results confirmed the fact that the “alternating” method developed here can accurately be used for in situ Raman monitoring under reactive plasma condition. The original analytic tool can be of great importance to monitor the characteristics of these nanostructured materials and readily define the ultimate conditions for targeted results

  13. In situ Raman spectroscopy for growth monitoring of vertically aligned multiwall carbon nanotubes in plasma reactor

    Labbaye, T.; Canizarès, A.; Gaillard, M.; Lecas, T.; Kovacevic, E.; Boulmer-Leborgne, Ch.; Strunskus, T.; Raimboux, N.; Simon, P.; Guimbretière, G.; Ammar, M. R.

    2014-11-01

    Portable and highly sensitive Raman setup was associated with a plasma-enhanced chemical vapor deposition reactor enabling in situ growth monitoring of multi-wall carbon nanotubes despite the combination of huge working distance, high growth speed and process temperature and reactive plasma condition. Near Edge X-ray absorption fine structure spectroscopy was used for ex situ sample analysis as a complementary method to in situ Raman spectroscopy. The results confirmed the fact that the "alternating" method developed here can accurately be used for in situ Raman monitoring under reactive plasma condition. The original analytic tool can be of great importance to monitor the characteristics of these nanostructured materials and readily define the ultimate conditions for targeted results.

  14. Liquid crystalline polymer nanocomposites reinforced with in-situ reduced graphene oxide

    D. Pedrazzoli

    2015-08-01

    Full Text Available In this work liquid-crystalline polymer (LCP nanocomposites reinforced with in-situ reduced graphene oxide are investigated. Graphene oxide (GO was first synthesized by the Hummers method, and the kinetics of its thermal reduction was assessed. GO layers were then homogeneously dispersed in a thermotropic liquid crystalline polymer matrix (Vectran®, and an in-situ thermal reduction of GO into reduced graphene oxide (rGO was performed. Even at low rGO amount, the resulting nanocomposites exhibited an enhancement of both the mechanical properties and the thermal stability. Improvements of the creep stability and of the thermo-mechanical behavior were also observed upon nanofiller incorporation. Furthermore, in-situ thermal reduction of the insulating GO into the more electrically conductive rGO led to an important surface resistivity decrease in the nanofilled samples.

  15. Next generation in-situ optical Raman sensor for seawater investigations

    Kolomijeca, A.; Kwon, Y.-H.; Ahmad, H.; Kronfeldt, H.-D.

    2012-04-01

    We introduce the next generation of optical sensors based on a combination of surfaced enhanced Raman scattering (SERS) and shifted excitation Raman difference spectroscopy (SERDS) suited for investigations of tiny concentrations of pollutions in the seawater. First field measurements were carried out in the Arctic area which is of global interest since it is more affected by global warming caused climatic changes than any other areas of our planet and it is a recipient for many toxic organic pollutants. A significant long-range atmospheric transport of pollutants to Svalbard is mainly originated from industrialized countries in Europe and North America during the last decades. Therefore, the main interest is to investigate the Arctic water column and also the sediments. Standard chemical methods for water/sediment analysis are extremely accurate but complex and time-consuming. The primary objective of our study was to develop a fast response in-situ optical sensor for easy to use and quick analysis. The system comprises several components: a handheld measurement head containing a 671 nm microsystem diode laser and the Raman optical bench, a laser driver electronics board, a custom-designed miniature spectrometer with an optical resolution of 8 cm-1 and a netbook to control the spectrometer as well as for data evaluation. We introduced for the first time the portable Raman sensor system on an Artic sea-trial during a three week cruise on board of the James Clark Ross research vessel in August 2011. Numerous Raman and SERS measurements followed by SERDS evaluations were taken around locations 78 N and 9 E. Different SERS substrates developed for SERS measurements in sea-water were tested for their capability to detect different substances (PAHs) in the water down to very small (nmol/l) concentrations. Stability tests of the substrates were carried out also for the applicability of our system e.g. on a mooring. Details of the in-situ Raman sensor were presented together with the measurements results from the Arctic area.

  16. Tests of in situ formation scenarios for compact multiplanet systems

    Schlaufman, Kevin C., E-mail: kschlauf@mit.edu [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2014-08-01

    Kepler has identified over 600 multiplanet systems, many of which have several planets with orbital distances smaller than that of Mercury. Because these systems may be difficult to explain in the paradigm of core accretion and disk migration, it has been suggested that they formed in situ within protoplanetary disks with high solid surface densities. The strong connection between giant planet occurrence and stellar metallicity is thought to be linked to enhanced solid surface densities in disks around metal-rich stars, so the presence of a giant planet can be a sign of planet formation in a high solid surface density disk. I formulate quantitative predictions for the frequency of long-period giant planets in these in situ models by translating the proposed increase in disk mass into an equivalent metallicity enhancement. I rederive the scaling of giant planet occurrence with metallicity as P{sub gp}=0.05{sub −0.02}{sup +0.02}×10{sup (2.1±0.4)[M/H]}=0.08{sub −0.03}{sup +0.02}×10{sup (2.3±0.4)[Fe/H]} and show that there is significant tension between the frequency of giant planets suggested by the minimum mass extrasolar nebula scenario and the observational upper limits. Consequently, high-mass disks alone cannot explain the observed properties of the close-in Kepler multiplanet systems and therefore migration is still important. More speculatively, I combine the metallicity scaling of giant planet occurrence with small planet occurrence rates to estimate the number of solar system analogs in the Galaxy. I find that in the Milky Way there are perhaps 4 × 10{sup 6} true solar system analogs with an FGK star hosting both a terrestrial planet in the habitable zone and a long-period giant planet companion.

  17. Detection of denitrification genes by in situ rolling circle amplification - fluorescence in situ hybridization (in situ RCA-FISH) to link metabolic potential with identity inside bacterial cells

    Hoshino, Tatsuhiko; Schramm, Andreas

    2010-01-01

    A target-primed in situ rolling circle amplification (in situ RCA) protocol was developed for detection of single-copy genes inside bacterial cells and optimized with Pseudomonas stutzeri, targeting nitrite and nitrous oxide reductase genes (nirS and nosZ). Two padlock probes were designed per gene...... identified as Candidatus Accumulibacter phosphatis by combining in situ RCA-FISH with 16S rRNA-targeted FISH. While not suitable for quantification because of its low detection frequency, in situ RCA-FISH will allow to link metabolic potential with 16S rRNA (gene)-based identification of single microbial...

  18. In situ gelling systems of ofloxacin: Comparative performance of in vivo precorneal drainage and pharmacokinetic study

    Vrushali S Kashikar

    2013-01-01

    Full Text Available Our present work describes the formulation and evaluation of an ocular deliver system of ofloxacin based on the concept of temperature-and ion-activated in situ gelling system. A combination of Pluronic F-127 and Pluronic F-68 along with chitosan, (pH-sensitive polymer also acts as a permeation enhancer was used in temperature and pH-triggered in situ gelling systems while gellan alone was used in ion-activated in situ gelling system. The formulation allows its easy instillation into the eye as a liquid (drops, forms transparent gel, and spreads over the corneal surface. At the formulation pH, transcorneal permeation profile of ofloxacin was comparable to that of in vitro release profile. In situ gel-forming ability of the developed systems significantly controls precorneal drainage as studied by gamma scintigraphy. Thus, increased residence time in the eye would help to increase the ocular bioavailability. The formulation was also found to be nonirritant and well tolerable. Cmax of in situ gelling formulation was found to be 1.5 times higher than marketed eye drops solution at the similar Tmax of 1 h.

  19. In situ surface biodegradation of restorative materials.

    Padovani, Gc; Fcio, Sbp; Ambrosano, Gmb; Sinhoreti, Mac; Puppin-Rontani, Rm

    2014-01-01

    SUMMARY This study aimed to evaluate the surface characteristics of restorative materials (roughness, hardness, chemical changes by energy-dispersive spectroscopy [EDX], and scanning electron microscopy [SEM]) submitted to in situ biodegradation. Fifteen discs of each material (IPS e.max [EM], Filtek Supreme [FS], Vitremer [VI], Ketac Molar Easymix [KM], and Amalgam GS-80 [AM]) were fabricated in a metallic mold (4.0 mm 1.5 mm). Roughness, hardness, SEM, and EDX were then evaluated. Fifteen healthy volunteers used a palatal device containing one disc of each restorative material for seven days. After the biodegradation, the roughness, hardness, SEM, and EDX were once again evaluated. Data obtained from the roughness and hardness evaluations were submitted to Kolmogorov-Smirnov and Tukey-Kramer tests (phardness among the materials were seen: EM>AM>FS>KM>VI. After biodegradation, the hardness was significantly altered among the materials studied: EM>AM>FS=KM>VI, along with a significant increase in the hardness for AM, KM, and VI. SEM images indicated degradation on the surface of all materials, showing porosities, cracks, and roughness. Furthermore, after biodegradation, FS showed the presence of Cl, K, and Ca on the surface, while F was not present on the VI and KM surfaces. EM and AM did not have alterations in their chemical composition after biodegradation. It was concluded that the dental biofilm accumulation in situ on different restorative materials is a material-dependent parameter. Overall, all materials changed after biodegradation: esthetic restorative materials showed increased roughness, confirmed by SEM, and the ionomer materials and silver amalgam showed a significantly higher hardness. Finally, the initial chemical composition of the composite resin and ionomer materials evaluated was significantly altered by the action of the biofilm in situ. PMID:24555699

  20. The treatment of in situ breast cancer

    Carcinoma in situ is the earliest histologically recognisable form of malignancy and as such provides an opportunity to treat the disease in a curative way. The two major variants, ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS) will be considered separately as the two conditions have divergent natural histories. DCIS is increasing in incidence since microcalcification may be detected radiologically in the screening of asymptomatic women. The extent of microcalcification may not indicate the extent of disease. It has yet to be determined whether there is a difference in behaviour of the tumour forming and the asymptomatic types of DCIS. After a biopsy has shown DCIS there will be residual DCIS at the biopsy site in one-third of patients, and multifocal DCIS in another third. A coexistent infiltrating carcinoma may be present in up to 16%. Due to sampling problems areas of invasion may be missed. Axillary nodal metastases are found in only 1% of patients with histological DCIS. Radical surgery by total or modified mastectomy is almost curative, but 3% of patients will die of metastases. Taking results of uncontrolled trials, local relapse rates are as follows: excision alone 50%, wide excision 30%, wide excision plus radiotherapy 20%. Two prospective trials are underway run by the EORTC and NSABP in which patients with DCIS are treated by wide excision with or without external radiotherapy. LCIS is usually an incidental finding with a bilateral predisposition to subsequent infiltrating carcinomas. Curative procedures such as bilateral mastectomy with reconstruction may represent overtreatment. A systemic rather than local approach would seem appropriate and a trial is now underway run by the EORTC in which patients with histologically confirmed LCIS are randomised to observation alone or to receive tamoxifen 20 mg daily for 5 years. (orig./MG)

  1. The treatment of in situ breast cancer

    Fentiman, I.S. (Guy' s Hospital, London (UK). Clinical Oncology Unit)

    1989-01-01

    Carcinoma in situ is the earliest histologically recognisable form of malignancy and as such provides an opportunity to treat the disease in a curative way. The two major variants, ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS) will be considered separately as the two conditions have divergent natural histories. DCIS is increasing in incidence since microcalcification may be detected radiologically in the screening of asymptomatic women. The extent of microcalcification may not indicate the extent of disease. It has yet to be determined whether there is a difference in behaviour of the tumour forming and the asymptomatic types of DCIS. After a biopsy has shown DCIS there will be residual DCIS at the biopsy site in one-third of patients, and multifocal DCIS in another third. A coexistent infiltrating carcinoma may be present in up to 16%. Due to sampling problems areas of invasion may be missed. Axillary nodal metastases are found in only 1% of patients with histological DCIS. Radical surgery by total or modified mastectomy is almost curative, but 3% of patients will die of metastases. Taking results of uncontrolled trials, local relapse rates are as follows: excision alone 50%, wide excision 30%, wide excision plus radiotherapy 20%. Two prospective trials are underway run by the EORTC and NSABP in which patients with DCIS are treated by wide excision with or without external radiotherapy. LCIS is usually an incidental finding with a bilateral predisposition to subsequent infiltrating carcinomas. Curative procedures such as bilateral mastectomy with reconstruction may represent overtreatment. A systemic rather than local approach would seem appropriate and a trial is now underway run by the EORTC in which patients with histologically confirmed LCIS are randomised to observation alone or to receive tamoxifen 20 mg daily for 5 years. (orig./MG).

  2. In-situ thermal testing program strategy

    In the past year the Yucca Mountain Site Characterization Project has implemented a new Program Approach to the licensing process. The Program Approach suggests a step-wise approach to licensing in which the early phases will require less site information than previously planned and necessitate a lesser degree of confidence in the longer-term performance of the repository. Under the Program Approach, the thermal test program is divided into two principal phases: (1) short-term in situ tests (in the 1996 to 2000 time period) and laboratory thermal tests to obtain preclosure information, parameters, and data along with bounding information for postclosure performance; and (2) longer-term in situ tests to obtain additional data regarding postclosure performance. This effort necessitates a rethinking of the testing program because the amount of information needed for the initial licensing phase is less than previously planned. This document proposes a revised and consolidated in situ thermal test program (including supporting laboratory tests) that is structured to meet the needs of the Program Approach. A customer-supplier model is used to define the Project data needs. These data needs, along with other requirements, were then used to define a set of conceptual experiments that will provide the required data within the constraints of the Program Approach schedule. The conceptual thermal tests presented in this document represent a consolidation and update of previously defined tests that should result in a more efficient use of Project resources. This document focuses on defining the requirements and tests needed to satisfy the goal of a successful license application in 2001, should the site be found suitable

  3. High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in-situ production

    X. Fan

    2013-05-01

    Full Text Available We present high-resolution measurements of carbon monoxide (CO concentrations from continuous analysis of a shallow ice core from the North Greenland Eemian Ice Drilling project (NEEM-2011-S1. An Optical Feedback Cavity Enhanced Absorption Spectrometer (OF-CEAS was coupled to a continuous melter system during a 4-week laboratory-based measurement campaign. This analytical setup generates highly stable measurements of CO concentrations with an external precision of 7.8 ppbv (1 sigma based on a comparison of replicate cores. The NEEM-2011-S1 CO record spans 1800 yr and exhibits highly variable concentrations at the scale of annual layers, ranging from 75 to 1327 ppbv. The most recent section of this record (i.e. since 1700 AD agrees with existing discrete CO measurements from the Eurocore ice core and the deep NEEM firn. However, it is difficult to interpret in terms of atmospheric CO variation due to high frequency, high amplitude spikes in the data. 68% of the elevated CO spikes are observed in ice layers enriched with pyrogenic aerosols. Such aerosols, originating from boreal biomass burning emissions, contain organic compounds, which can be oxidized or photodissociated to produce CO in-situ. We suggest that elevated CO concentration features could present a new integrative proxy for past biomass burning history. Furthermore, the NEEM-2011-S1 record reveals an increase in baseline CO level prior to 1700 AD (129 m depth, with the concentration remaining high even for ice layers depleted in dissolved organic carbon (DOC. Overall, the processes driving in-situ production of CO within the NEEM ice are complex and may involve multiple chemical pathways.

  4. High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in-situ production

    Fan, X.; Chappellaz, J.; Rhodes, R. H.; Stowasser, C.; Blunier, T.; McConnell, J. R.; Brook, E. J.; Preunkert, S.; Legrand, M.; Desbois, T.; Romanini, D.

    2013-05-01

    We present high-resolution measurements of carbon monoxide (CO) concentrations from continuous analysis of a shallow ice core from the North Greenland Eemian Ice Drilling project (NEEM-2011-S1). An Optical Feedback - Cavity Enhanced Absorption Spectrometer (OF-CEAS) was coupled to a continuous melter system during a 4-week laboratory-based measurement campaign. This analytical setup generates highly stable measurements of CO concentrations with an external precision of 7.8 ppbv (1 sigma) based on a comparison of replicate cores. The NEEM-2011-S1 CO record spans 1800 yr and exhibits highly variable concentrations at the scale of annual layers, ranging from 75 to 1327 ppbv. The most recent section of this record (i.e. since 1700 AD) agrees with existing discrete CO measurements from the Eurocore ice core and the deep NEEM firn. However, it is difficult to interpret in terms of atmospheric CO variation due to high frequency, high amplitude spikes in the data. 68% of the elevated CO spikes are observed in ice layers enriched with pyrogenic aerosols. Such aerosols, originating from boreal biomass burning emissions, contain organic compounds, which can be oxidized or photodissociated to produce CO in-situ. We suggest that elevated CO concentration features could present a new integrative proxy for past biomass burning history. Furthermore, the NEEM-2011-S1 record reveals an increase in baseline CO level prior to 1700 AD (129 m depth), with the concentration remaining high even for ice layers depleted in dissolved organic carbon (DOC). Overall, the processes driving in-situ production of CO within the NEEM ice are complex and may involve multiple chemical pathways.

  5. In situ force-balance tensiometry

    Lapham, G. S.; Dowling, D. R.; Schultz, W. W.

    Although a fundamental physical parameter, surface tension is difficult to measure. Common tensiometry inaccuracy comes from failure to control air-liquid-solid contact conditions, or account for liquid meniscus geometry and buoyancy corrections. This paper describes an in situ tensiometry technique, based on withdrawal of a thin-walled tube from the liquid interface, that enforces a known air-liquid-solid contact condition. This technique can be pursued at any level of experimental hygiene. Experimental results for filtered tap water, an alcohol-water solution, and a surfactant-water solution show that results repeatable to three significant digits are obtained with modest effort for a variety of geometrical parameters.

  6. Development of in-situ monitoring system

    Development of in-situ monitoring system using an optical fiber to measure the real time temperature variation of subsurface water for the evaluation of flow characteristics. We describe the feasibility of developing a fiber-optic temperature sensor using a thermochromic material. A sensor-tip is fabricated by mixing of a thermochromic material powder. The relationships between the temperatures and the output voltages of detectors are determined to measure the temperature of water. It is expected that the fiber-optic temperature monitoring sensor using thermochromic material can be used to measure the real time temperature variation of subsurface water

  7. In Situ Preservation of Historic Spacecraft

    Barclay, R.; Brooks, R.

    The loss of the Mir space station is shown to symbolize a new consciousness of the value of space artefacts. The reasons why such artefacts as Mir become historic objects worthy of preservation are examined. Preservation of space vehicles in situ is discussed, with particular reference to safety, monitoring and long term costs. An argument is made for a wider definition for World Heritage designations to include material beyond the surface of the Earth, and for international bodies to assess, monitor and oversee these projects. Such heritage sites are seen as an economic driver for the development of space tourism in the 21st century.

  8. In-situ combustion simulation with dynamic grid; Simulacao de combustao in-situ com grades dinamicas

    Ferraz, C.H.A.; Almeida, M.P.; Vasconcelos, H.H.M.; Oliveira, C.L.N. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Fisica

    2008-07-01

    In this work, we study the effects of the introduction of 3D dynamics grids on in-situ combustion simulation results as means of describing the most realistically possible the dynamics of these processes, in particular of the combustion front. The dynamic refinement of grid blocks is important because in thesis it enhances the precision in the calculations once that more grid blocks are considered in the grid, especially within the narrow region of high temperature of the combustion front. We have performed dry combustion simulation (only water injection) and wet combustion simulation (air + water injection) for forward combustion in a variety of well configurations. Our initial results have shown changes in oil, water and gas productions when we use dynamics grids in the simulations, making clear the relevance of its usage in the understanding of the dynamics of these processes. (author)

  9. Apparatus for in situ monitoring of copper in coastal waters.

    Chapman, Conrad S; Cooke, Richard D; Salaün, Pascal; van den Berg, Constant M G

    2012-10-26

    Apparatus is designed and tested to determine metals in situ in seawater. Voltammetry with a vibrating gold microwire electrode (VGME) is combined with a battery powered potentiostat and a processor board and is tested for in situ monitoring of copper (Cu) in coastal waters. The VGME was combined with solid state reference and counter electrodes to make a single vibrating probe which was rated up to a depth of 40 m. The measuring mode for Cu was square-wave anodic stripping voltammetry whilst dissolved oxygen (DO) was monitored by a linear sweep scan in a negative potential direction. The working electrode was reactivated between measurements using a suitable potential sequence. The novelties of this work are the field-testing of apparatus incorporating a VGME for copper monitoring, which eliminates the need for pumping and reagents, but has sufficient sensitivity for low ambient levels of copper, and the use of a novel potential sequence to stabilise the response over a long time period. The apparatus has a measuring time of about 6 weeks and a measuring frequency of 12 h(-1). Measurement is reagent-free and power use is low as no pump is required. Experiments are carried out to test the stability of response of the system at various temperatures and its robustness with respect to long-term copper monitoring. Preliminary data were obtained during autonomous deployment over several weeks on a buoy in the Irish Sea. Vertical movement of the buoy caused individual measurements to have a variability of about 15%. It was found that longer term variability of the electrode could be minimised by normalisation of the Cu response over that of DO as the response was related to diffusion through the electrode surface which was similarly affected. The detected fraction of Cu (labile Cu) amounted to 1.5-4 nM during different deployments at a total Cu concentration of ∼10 nM. The same ratio was found by voltammetry in samples taken to the laboratory. The new apparatus has demonstrated that metals in coastal waters can be monitored at trace level, much facilitating the monitoring of outfalls and local water contamination. Because of its sensitivity the apparatus would be of use in estuarine as well as coastal waters, with the aim of monitoring intermittent variability in the copper concentration. PMID:22983404

  10. Formation of neuromuscular junctions in transplanted peroneus longus muscles in the rat. A quantitative comparison with reinnervation of the muscle in situ.

    Vedung, S; Olsson, Y

    1983-01-01

    The formation of neuromuscular junctions in free heterotopic muscle transplants in the rat has been studied quantitatively and compared with the reinnervation of the muscle in situ. The AChE-containing area and the nerve terminal were stained in the same longitudinal section and the length of end-plate, the average number of nerve terminal branch points within the end-plate and the terminal innervation ratio (TIR) were determined. In denervated muscles we noticed early disappearance of nerves whereas the AChE-stained end-plates were visible after eight weeks. The reinnervation of the muscle in situ and after transplantation showed considerable similarities. Early during reinnervation the number of AChE positive areas increased and many of them were innervated by more than one axon. Terminal axons were also seen innervating more than one end-plate situated on the same or on different muscle fibres. Later the number of end-plates decreased and they were innervated by only one axon. The end-plate length reached normal value in the reinnervated muscle in situ but remained smaller in the transplanted muscle. In all reinnervated muscles ultraterminal sprouting was found as indicated by an increased number of nerve terminal branch points within the end-plate area. The TIR was increased in all reinnervated muscles due to terminal and ultraterminal sprouting of the axon. No significant difference in reinnervation was noted between normal and predenervated transplants. The reinnervation of transplanted muscles obviously has similarities not only with the reinnervation of normal muscles but also with the development of muscular innervation during early postnatal growth. In spite of the plasticity of the peripheral nerve the transplanted muscles underwent considerable atrophy which may have been enhanced by the unphysiological placement of the muscles in the abdomen. However, this experimental model made it possible to study reinnervation of muscle fibres only originating from the graft. PMID:6622987

  11. Molecular cytogenetics using fluorescence in situ hybridization

    Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

    1990-12-07

    Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

  12. Inherently safe in situ uranium recovery.

    Krumhansl, James Lee; Beauheim, Richard Louis; Brady, Patrick Vane; Arnold, Bill Walter; Kanney, Joseph F.; McKenna, Sean Andrew

    2009-05-01

    Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

  13. Biophotonic in situ sensor for plant leaves

    Conejo, Elian; Frangi, Jean-Pierre; Rosny, Gilles de

    2010-04-01

    Knowledge of the water concentration of plants can be helpful in several environmental and agricultural domains. There are many methods for the determination of water content in plant leaves; however, most of them give a relative moisture level or an analytical measure after a previous calibration procedure. Even for other biochemical compounds such as dry matter or chlorophyll, the measurement techniques could be destructive. For this reason, a nondestructive method has been developed to measure the biochemical compounds of a plant leaf, using an infrared spectroscopy technique. One important advantage is the simplicity of the device (RAdiometre portatif de Mesure In Situ, RAMIS) and its capability to perform measurements in situ. The prototype is a leaf-clip configuration and is made of LEDs at five wavelengths (656, 721, 843, 937, and 1550 nm), and a silicon/germanium photosensor. To compute the water content of vegetative leaves, the radiative transfer model PROSPECT was implemented. This model can accurately predict spectral transmittances in the 400 nm to 2500 nm spectral region as a function of the principal leaf biochemical contents: water, dry matter, and chlorophyll. Using the transmittance measured by RAMIS into an inversion procedure of PROSPECT: A Model of Leaf Optical Properties Spectra, we are able to compute the values of water contents that show an agreement with the water contents measured directly using dry weight procedures. This method is presented as a possibility to estimate other leaf biochemical compounds using appropriate wavelengths.

  14. In situ migration experiment in argillaceous formation

    International cooperative R and D has been performed within the five years framework of the bilateral agreement between PNC (Power Reactor and Nuclear Fuel Development Corporation) and SCK/CEN (Studiecentrum voor Kernergie/Centre D'etude de L'energie Nucleaire, Mol, Belgium) which is focused on 'The Migration Experiment in argillaceous formation.' This Tertiary argillaceous formation, called Boom clay, is located at about 230m depth in Mol-Dessel area, Belgium. The argillaceous rock is considered to have a high capability for retardation to radionuclides when they migrate in geosphere because of a high content of clay minerals and dissolved carbon-rich pore water. The main purpose of this collaboration work is to characterize the migration phenomena in sedimentary rock through understanding of the behaviour of radionuclides migration in the argillaceous formation. The present report describes the preliminary results of in situ one-dimensional migration experiment with labelled clay core emplaced in borehole under advective condition. In the experiment, radioactive tracer Sr-85 and Eu-152+154 have been used in order to determine the apparent dispersion coefficient and retardation factor of Boom clay. Finally, the following conclusions were obtained by in situ measurement and calculation based on a appropriate migration model; a) From the Sr-85 experiment, diffusive behavior is interpreted to be a dominant phenomena on radionuclides transportation. b) From the Eu-152+154 experiment, very small non-retarded fraction is observed. (author)

  15. GAS TURBINE REHEAT USING IN SITU COMBUSTION

    D.M. Bachovchin; T.E. Lippert; R.A. Newby P.G.A. Cizmas

    2004-05-17

    In situ reheat is an alternative to traditional gas turbine reheat design in which fuel is fed through airfoils rather than in a bulky discrete combustor separating HP and LP turbines. The goals are to achieve increased power output and/or efficiency without higher emissions. In this program the scientific basis for achieving burnout with low emissions has been explored. In Task 1, Blade Path Aerodynamics, design options were evaluated using CFD in terms of burnout, increase of power output, and possible hot streaking. It was concluded that Vane 1 injection in a conventional 4-stage turbine was preferred. Vane 2 injection after vane 1 injection was possible, but of marginal benefit. In Task 2, Combustion and Emissions, detailed chemical kinetics modeling, validated by Task 3, Sub-Scale Testing, experiments, resulted in the same conclusions, with the added conclusion that some increase in emissions was expected. In Task 4, Conceptual Design and Development Plan, Siemens Westinghouse power cycle analysis software was used to evaluate alternative in situ reheat design options. Only single stage reheat, via vane 1, was found to have merit, consistent with prior Tasks. Unifying the results of all the tasks, a conceptual design for single stage reheat utilizing 24 holes, 1.8 mm diameter, at the trailing edge of vane 1 is presented. A development plan is presented.

  16. In situ SU-8 silver nanocomposites

    Søren V. Fischer

    2015-07-01

    Full Text Available Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution to this problem, an easy new method of fabricating silver nanocomposites by an in situ reduction of precursors within the epoxy-based photoresist SU-8 has been developed. AgNO3 dissolved in acetonitrile and mixed with the epoxy-based photoresist SU-8 forms silver nanoparticles primarily during the pre- and post-exposure soft bake steps at 95 °C. A further high-temperature treatment at 300 °C resulted in the formation of densely homogeneously distributed silver nanoparticles in the photoresist matrix. No particle growth or agglomeration of nanoparticles is observed at this point. The reported new in situ silver nanocomposite materials can be spin coated as homogeneous thin films and structured by using UV lithography. A resolution of 5 µm is achieved in the lithographic process. The UV exposure time is found to be independent of the nanoparticle concentration. The fabricated silver nanocomposites exhibit high plasmonic responses suitable for the development of new optoelectronic and optical sensing devices.

  17. A memorable week

    2012-01-01

    This has been a memorable week for CERN, starting with the award of a Special Fundamental Physics Prize and ending with the handover of the CERN Council Presidency from Michel Spiro to Agnieszka Zalewska. In between, the LHC team demonstrated its expertise with a successful pilot run with 25 nanosecond bunch spacing, a new application for Associate Membership was received, and we had good news on the budget.   The award of the Fundamental Physics Prize, and the manner in which it was divided between ATLAS, CMS and the LHC, is fitting recognition of the efforts of the thousands of people who have contributed over many years to the success of our flagship scientific endeavour. In making the award, the Milner Foundation aims to raise the profile of fundamental physics and its value to society. The Fundamental Physics Prize comes hot on the heels of the European Physical Society’s first Edison Volta Prize, which Sergio Bertolucci, Steve Myers and I were honoured to accept on behalf of t...

  18. Data of low-dose phase-based X-ray imaging for in situ soft tissue engineering assessments.

    Izadifar, Zohreh; Honaramooz, Ali; Wiebe, Sheldon; Belev, George; Chen, Xiongbiao; Chapman, Dean

    2016-03-01

    This article presents the data of using three phase-based X-ray imaging techniques to characterize biomaterial scaffold and soft tissues in situ, as reported in our study "Low-dose phase-based X-ray imaging techniques for in situ soft tissue engineering assessments" [1]. The examined parameters include the radiation dose, scan time, and image quality, which are all critical to longitudinal in situ live animal assessments. The data presented were obtained from three dimensional imaging of scaffolds in situ cartilage by means of synchrotron-based computed tomography-diffraction enhanced imaging (CT-DEI), analyzer based imaging (CT-ABI), and in-line phase contrast imaging (CT-PCI) at standard and low dose imaging modalities. PMID:26909381

  19. In situ vitrification large-scale operational acceptance test analysis

    A thermal treatment process is currently under study to provide possible enhancement of in-place stabilization of transuranic and chemically contaminated soil sites. The process is known as in situ vitrification (ISV). In situ vitrification is a remedial action process that destroys solid and liquid organic contaminants and incorporates radionuclides into a glass-like material that renders contaminants substantially less mobile and less likely to impact the environment. A large-scale operational acceptance test (LSOAT) was recently completed in which more than 180 t of vitrified soil were produced in each of three adjacent settings. The LSOAT demonstrated that the process conforms to the functional design criteria necessary for the large-scale radioactive test (LSRT) to be conducted following verification of the performance capabilities of the process. The energy requirements and vitrified block size, shape, and mass are sufficiently equivalent to those predicted by the ISV mathematical model to confirm its usefulness as a predictive tool. The LSOAT demonstrated an electrode replacement technique, which can be used if an electrode fails, and techniques have been identified to minimize air oxidation, thereby extending electrode life. A statistical analysis was employed during the LSOAT to identify graphite collars and an insulative surface as successful cold cap subsidence techniques. The LSOAT also showed that even under worst-case conditions, the off-gas system exceeds the flow requirements necessary to maintain a negative pressure on the hood covering the area being vitrified. The retention of simulated radionuclides and chemicals in the soil and off-gas system exceeds requirements so that projected emissions are one to two orders of magnitude below the maximum permissible concentrations of contaminants at the stack

  20. In-situ calibration of the implantable force transducer.

    Herzog, W; Hasler, E M; Leonard, T R

    1996-12-01

    Recently, an implantable force transducer (IFT) has been introduced [Xu et al. (1992, J. Biomech. Engng 114, 170-177)] which can be used in tight spaces where force recordings with established transducers, such as the buckle-type transducers, are not possible because of impingement artifacts. The IFT is easily implanted in chronic animal preparations; however, calibration of the IFT in terminal experiments has produced unreliable results. The problems of IFT calibration are that minute movements of the transducer within the tendon, slight misalignments of the tendon, or slight errors in the line of pull cause dramatic changes in the IFT voltage output for a given applied calibration load. Here, we propose a method that eliminates the above calibration problems primarily because the target tendon is left in situ, the calibration loads are applied by the muscles which insert into the target tendon, and the transducer is implanted into the target tendon about two weeks prior to calibration. The theoretical and experimental approaches are demonstrated for the cat patellar tendon, but in principle can be performed with any tendon. The results are repeatable, lie within expected values, and reproduce some of the basic properties which have been observed in prior IFT testing. PMID:8945667

  1. In-situ bioaugmentation of vadose zone restoration

    Leakage from an underground gasoline storage tank caused evacuation from a restaurant and an insurance company. An engineering consultant was engaged to correct the problem. Upon remedy of the habitability situation, a groundwater recovery system was designed to recover whatever open-quotes free productclose quotes gasoline could be collected. Since traditional open-quotes Pump and treatclose quotes remedial technologies are successful only to the extent that the contaminant is mobile, an alternative is necessary to effectively remediate that contamination which is recalcitrant. At this point, Waste Stream Technology was enlisted to propose an in-situ remedial action plan. Approximately five injection wells were installed around the perimeter and in the zone of influence of each of eight recovery wells. The injection wells were designed to distribute the bacteria at various depths in the vadose zone. Bacteria were cultured on site in Waste Stream's proprietary bioreactor. Bacterial and nutrient applications were injected on a weekly basis. Bacterial population dynamics and BETX levels were monitored throughout the course of the remediation. Although the remediation is currently in progress, disappearance of open-quotes free productclose quotes on the water table and elimination of benzene in the groundwater over a reasonable time period marked the success of this project

  2. Support Routines for In Situ Image Processing

    Deen, Robert G.; Pariser, Oleg; Yeates, Matthew C.; Lee, Hyun H.; Lorre, Jean

    2013-01-01

    This software consists of a set of application programs that support ground-based image processing for in situ missions. These programs represent a collection of utility routines that perform miscellaneous functions in the context of the ground data system. Each one fulfills some specific need as determined via operational experience. The most unique aspect to these programs is that they are integrated into the large, in situ image processing system via the PIG (Planetary Image Geometry) library. They work directly with space in situ data, understanding the appropriate image meta-data fields and updating them properly. The programs themselves are completely multimission; all mission dependencies are handled by PIG. This suite of programs consists of: (1)marscahv: Generates a linearized, epi-polar aligned image given a stereo pair of images. These images are optimized for 1-D stereo correlations, (2) marscheckcm: Compares the camera model in an image label with one derived via kinematics modeling on the ground, (3) marschkovl: Checks the overlaps between a list of images in order to determine which might be stereo pairs. This is useful for non-traditional stereo images like long-baseline or those from an articulating arm camera, (4) marscoordtrans: Translates mosaic coordinates from one form into another, (5) marsdispcompare: Checks a Left Right stereo disparity image against a Right Left disparity image to ensure they are consistent with each other, (6) marsdispwarp: Takes one image of a stereo pair and warps it through a disparity map to create a synthetic opposite- eye image. For example, a right eye image could be transformed to look like it was taken from the left eye via this program, (7) marsfidfinder: Finds fiducial markers in an image by projecting their approximate location and then using correlation to locate the markers to subpixel accuracy. These fiducial markets are small targets attached to the spacecraft surface. This helps verify, or improve, the pointing of in situ cameras, (8) marsinvrange: Inverse of marsrange . given a range file, re-computes an XYZ file that closely matches the original. . marsproj: Projects an XYZ coordinate through the camera model, and reports the line/sample coordinates of the point in the image, (9) marsprojfid: Given the output of marsfidfinder, projects the XYZ locations and compares them to the found locations, creating a report showing the fiducial errors in each image. marsrad: Radiometrically corrects an image, (10) marsrelabel: Updates coordinate system or camera model labels in an image, (11) marstiexyz: Given a stereo pair, allows the user to interactively pick a point in each image and reports the XYZ value corresponding to that pair of locations. marsunmosaic: Extracts a single frame from a mosaic, which will be created such that it could have been an input to the original mosaic. Useful for creating simulated input frames using different camera models than the original mosaic used, and (12) merinverter: Uses an inverse lookup table to convert 8-bit telemetered data to its 12-bit original form. Can be used in other missions despite the name.

  3. In situ studies of fracture in solids

    Electron microscope studies were made of the propagation of microcracks during in situ tensile deformation of stainless steel, molybdenum and magnesium oxide representing ductile, semi-brittle and brittle solids. As the stress is applied, the cracks are initiated at the edge of holes in the thinned foils. The extent of plastic activity around the cracks is measured in terms of the density and the distribution of dislocations and is sensitive to the ductile/brittle nature of the solid. The slip systems of the dislocations are determined by contrast analysis and stereoscopic observation. In stainless steel and magnesium oxide, the dislocations are relatively straight and they lie nearly perpendicular to the direction of the crack propagation, whereas in molybdenum the dislocations are in the form of irregular tangles which are stretched along the direction of the crack propagation. These observations are discussed in terms of the model of Dugdale concerning the formation of plastic zones under uniaxial loading in plane stress conditions

  4. In situ corrosion monitoring of steam generators

    An ac electrochemical technique which meets the basic requirements for an in situ localized corrosion monitor within the secondary coolant of PWR steam generators has been investigated. The technique uses two electrodes to measure the electrochemical impedance of a surface in an occluded region with high heat flux. The impedance is related to the kinetics of corrosion. Marked decreases indicate the onset of a high corrosion rate. Experiments have demonstrated the ability of the technique to determine the onset of corrosion under conditions of high solution resistance and solution agitation due to local boiling. Experiments have shown the technique operates similarly in pressurized 3000C water, 1,400 ppM in Na2SO4

  5. In situ erosion of cohesive sediment

    There has been increasing interest in tidal power schemes and the effect of a tidal energy barrage on the environment. A large man-made environmental change, such as a barrage, would be expected to have significant effects on the sediment distribution and stability of an estuary and these effects need to be assessed when considering a tidal barrage project. This report describes the development of apparatus for in-situ measurements of cohesive sediment erosion on inter-tidal mudflats. Development of the prototype field erosion bell and field testing was commissioned on behalf of the Department of Trade and Industry by the Energy Technology Support Unit (ETSU). This later work commenced in August 1991 and was completed in September 1992. (Author)

  6. In situ soil remediation: Bacteria or fungi?

    Contamination of the environment is not a new problem. For most of recorded history, the unwanted byproducts of industrial and residential processes have been dumped into unlined pits or nearby streams. Although disposal techniques have greatly improved, significant quantities of hazardous materials are still being released to the environment via accidental spills and leaking underground storage tanks. One particular group of contaminants of critical environmental concern is polycyclic aromatic hydrocarbons (PAHs). PAH-contaminated sites typically cover large areas; therefore, the development of in situ remediation techniques such as bioremediation is strongly emphasized. In situations when inherent microorganisms are not capable of degrading the contaminants, foreign strains must be used. Bioremediation experiments were conducted to compare the remediation efficiencies of a bacteria and a fungus for an industrially PAH contaminated soil. Specifically, the use of three supplemental nutrient solutions were investigated in conjunction with the bacteria Achromobacter sp. and fungus Cunninghamella echinulata var. elegans

  7. In situ corrosion monitoring of steam generators

    An a.c. electrochemical technique that meets the basic requirements for an in situ localized corrosion monitor within the secondary coolant of PWR steam generators has been investigated. The technique uses two electrodes to measure the electrochemical impedance of a surface in an occluded region with high heat flux. This impedance is related to the kinetics of corrosion and marked decreases indicate the onset of a high corrosion rate. Experiments have demonstrated the ability of the technique to determine the onset of corrosion under conditions of high solution resistance and solution agitation due to local boiling. The technique operates similarly in pressurized 3000C water containing 1400 ppm Na2SO4. (author)

  8. Exprimentation in situ : principes et perspectives

    Olivier Geffard, Benoit Ferrari, Arnaud Chaumot et Bernard Montuelle

    2010-05-01

    Full Text Available Identifier l'origine d'une perturbation, discriminer un stress physique ou chimique, et quantifier les liens de cause effet des pollutions supposent de recueillir des donnes ncessaires l'valuation de la qualit des eaux. l'heure actuelle, la majorit des donnes est issue de tests de laboratoire, obtenue dans un cadre trs contrl. Les donnes recueillies dans les conditions naturelles sont trs parcellaires et encore peu rpandues mme si leur dveloppement serait extrmement utile. Quels sont les principes de ces exprimentations in situ, leur intrt, dans quelle mesure peuvent-elles tre dployes une large chelle ? Les auteurs font le point sur ces questions.

  9. In situ investigations at Avery Island

    Descriptions and representative data are given for the in situ investigations being performed in the Avery Island Mine. Sufficient detail is presented such that investigators can judge whether any of the studies being performed would be valuable for their numerical modeling exercises. The basic investigations being performed include heater tests, brine migration experiments, and flatjack tests. The heater tests consist of the emplacement of single simulated waste canisters with different power levels. The bulk thermal and mechanical response is measured of the salt surrounding the emplacement. The brine migration studies involve the measurement of moisture inflow into heated boreholes. The flatjack studies are an investigation of the deformation of the borehole when subjected to controlled boundary conditions of stress and temperature

  10. In situ secondary ion mass spectrometry analysis

    Groenewold, G.S.; Applehans, A.D.; Ingram, J.C.; Delmore, J.E.; Dahl, D.A.

    1993-01-01

    The direct detection of tributyl phosphate (TBP) on rocks using molecular beam surface analysis [MBSA or in situ secondary ion mass spectrometry (SIMS)] is demonstrated. Quantities as low as 250 ng were detected on basalt and sandstone with little or no sample preparation. Detection of TBP on soil has proven to be more problematic and requires further study. Ethylenediaminetetraacetic acid (EDTA) is more difficult to detect because it is very reactive with surfaces of interest. Nevertheless, it is possible to detect EDTA if the acidity of the surface is controlled. The detection of EDTA-metal complexes is currently an open question, but evidence is presented for the detection of ions arising from a EDTA-lead complex. Carboxylic acids (i.e., citric, ascorbic, malic, succinic, malonic, and oxalic) give characteristic SIM spectra, but their detection on sample surfaces awaits evaluation.

  11. Minimally Invasive In Situ Cubital Tunnel Decompression.

    Koehler, Steven M; Lovy, Andrew J; Guerra, Sara M; Chawla, Harshvardhan; Hausman, Michael R

    2016-03-01

    The purpose of this study is to describe a modified technique for a minimally invasive approach to in situ ulnar nerve decompression and to provide long-term follow-up. Thirty-one patients were included. DASH and MHQ scores were measured. Mean postoperative DASH score was 10. Eighty percent of patients achieved a postoperative DASH score under 10. Average postoperative MHQ scores were as follows: overall hand function 89, activities of daily living 93, work 92, pain 7, esthetics 95, and satisfaction 84. There were no postoperative neurological complications. No patient required open decompression or transposition. There were no wound complications. This technique addresses all points of possible compression, results in outcomes similar to those reported in the literature, and results in excellent cosmesis. It is a simple and safe technique that avoids the complexities of endoscopy and transposition and has proven to be successful. PMID:26829676

  12. Reverse osmosis membrane allows in situ regeneration

    The use of mineral membranes on metallic supports has provided a novel solution to the problem of filtration by the reverse osmosis process. A new reverse osmosis membrane is described which is capable of resisting high operational temperatures (1200C), fluctuations in pH(3 to 12) and high pressure (100 bar), as well as significant chlorine concentrations. In addition, the membrane can be regenerated in-situ on the same porous metal support. Numerous membranes can thus be used over the multi-year life of the porous support. Moreover, accidental damage to the membrane is of no great consequence as the membrane itself can be easily replaced. The life of the installation can thus be extended and the overall cost of filtration reduced. The membrane's various applications include water and effluent treatment in the nuclear power industry. (author)

  13. Unannounced in situ simulation of obstetric emergencies

    Sorensen, Jette Led; Lottrup, Pernille; van der Vleuten, Cees; Andersen, Kristine Sylvan; Simonsen, Mette; Emmersen, Pernille; Rosthøj, Susanne; Ottesen, Bent

    2014-01-01

    AIM: To describe how unannounced in situ simulation (ISS) was perceived by healthcare professionals before and after its implementation, and to describe the organisational impact of ISS. STUDY DESIGN: Ten unannounced ISS involving all staff were scheduled March-August 2007. Questionnaire surveys on...... staff perceptions were conducted before (2003-2006) and after (2007-2008) implementation of unannounced ISS. Information from the debriefing sessions following each ISS constituted a proxy measure of the organisational impact of the ISS. RESULTS: Five out of ten of the unannounced ISS scheduled were...... conducted. Twenty-three members of the staff at work on a scheduled day for ISS were randomly selected to participate. Questionnaires before implementation revealed that 137/196 (70%) of staff members agreed or strongly agreed that ISS was a good idea and 52/199 (26%) thought it likely to be stressful and...

  14. Underground openings for in situ experiments

    In situ tests include a wide variety of heater experiments with single and multiple arrays at full and reduced scale, block tests, heated room and pillar tests, brine and water migration experiments, permeability tests, fracture hydrology and groundwater chemistry studies, instrumentation development and testing, and other investigations. This article describes the identification of underground openings to accommodate such tests and the concept of a coupled hydrologic-thermomechanical experiment. The hydro/thermomechanical experimental program has five stages: 1) design and fabrication; 2) baseline studies; 3) chamber excavation; 4) test chamber experiment; and 5) data analysis and modeling. From the calculations presented, it was concluded that a large volume of rock (approximately 50 times that in the Stripa full-scale heater test) can be influenced within a reasonable time in the hydro/thermomechanical experiment, thereby bridging the gap between laboratory and repository-sized experiments

  15. Chemoport anchoring the in situ technique

    Krishnamachar Harish

    2011-08-01

    Full Text Available Chemoports are subcutaneously placed long term central venous access devices usually inserted under local anaesthesia. Rare complications include port inversion or flip over. These can be prevented by anchoring the port to the tissues at its base. We describe an in situ technique of port anchoring. Here, the port is first fixed temporarily to the overlying skin by Huber needle, thus facilitating placement of fixing sutures without port manipulation. The described technique is safe and we have not encountered complications. In addition, ex - planting the port was easier due to the use of delayed absorbable sutures. It is safer to anchor the port even if the port pocket ensures that the port fits in snugly. This described technique results in minimal manipulation of portcatheter system thereby ensuring that the catheter tip which is properly placed remains unaltered.

  16. In-situ Resources In Space

    Curreri, Peter A.

    2005-01-01

    This tutorial is a primer on the motivational and materials science basis for utilizing space resources to lower the cost and increase the safety and reliability of human systems beyond Earth's orbit. Past research in materials processing in orbit will be briefly reviewed to emphasize the challenges and advantages inherent in processing materials in space. Data on resource availability from human Lunar and robotic/sensor missions beyond the Moon will be overviewed for resource relevance to human exploration and development of space. Specific scenarios such as propellant production on the Moon and Mars, and lunar photovoltaic power production from in-situ materials will be discussed in relation to exploration and commercialization of space. A conclusion will cover some of the visionary proposals for the use of space resources to extend human society and prosperity beyond Earth.

  17. Demonstration testing and evaluation of in situ soil heating. Revision 1, Demonstration system design

    Over the last nine years IIT Research Institute (IITRI) has been developing and testing the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. The vaporized contaminants, water vapor and air are recovered from the heated zone by means of a vacuum manifold system which collects gases from below surface as well as from the soil surface. A vapor barrier is used to prevent fugitive emissions of the contaminants and to control air infiltration to minimize dilution of the contaminant gases and vapors. The recovered gases and vapors are conveyed to an on site vapor treatment system for the clean up of the vent gases. Electrical energy is applied to the soil by forming an array of electrodes in the soil which are electrically interconnected and supplied with power. The electrodes are placed in drilled bore holes which are made through the contaminated zone. There are two versions of the in situ heating and soil treatment process: the f irst version is called the In Situ Radio Frequency (RF) Soil Decontamination Process and the second version is called the In Situ Electromagnetic (EM) Soil Decontamination Process. The first version, the RF Process is capable of heating the soil in a temperature range of 100 degrees to 400 degrees C. The soil temperature in the second version, the EM Process, is limited to the boiling point of water under native conditions. Thus the soil will be heated to a temperature of about 85 degrees to 95 degrees C. In this project IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site due to the fact that most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 degrees to 95 degrees C

  18. In situ exploration of large dynamic networks.

    Hadlak, Steffen; Schulz, Hans-Jrg; Schumann, Heidrun

    2011-12-01

    The analysis of large dynamic networks poses a challenge in many fields, ranging from large bot-nets to social networks. As dynamic networks exhibit different characteristics, e.g., being of sparse or dense structure, or having a continuous or discrete time line, a variety of visualization techniques have been specifically designed to handle these different aspects of network structure and time. This wide range of existing techniques is well justified, as rarely a single visualization is suitable to cover the entire visual analysis. Instead, visual representations are often switched in the course of the exploration of dynamic graphs as the focus of analysis shifts between the temporal and the structural aspects of the data. To support such a switching in a seamless and intuitive manner, we introduce the concept of in situ visualization--a novel strategy that tightly integrates existing visualization techniques for dynamic networks. It does so by allowing the user to interactively select in a base visualization a region for which a different visualization technique is then applied and embedded in the selection made. This permits to change the way a locally selected group of data items, such as nodes or time points, are shown--right in the place where they are positioned, thus supporting the user's overall mental map. Using this approach, a user can switch seamlessly between different visual representations to adapt a region of a base visualization to the specifics of the data within it or to the current analysis focus. This paper presents and discusses the in situ visualization strategy and its implications for dynamic graph visualization. Furthermore, it illustrates its usefulness by employing it for the visual exploration of dynamic networks from two different fields: model versioning and wireless mesh networks. PMID:22034354

  19. PERFORMANCE CONFIRMATION IN-SITU INSTRUMENTATION

    The purpose of this document is to identify and analyze the types of in-situ instruments and methods that could be used in support of the data acquisition portion of the Performance Confirmation (PC) program at the potential nuclear waste repository at Yucca Mountain. The PC program will require geomechanical , geophysical, thermal, and hydrologic instrumentation of several kinds. This analysis is being prepared to document the technical issues associated with each type of measurement during the PC period. This analysis utilizes the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a) as its starting point. The scope of this analysis is primarily on the period after the start of waste package emplacement and before permanent closure of the repository, a period lasting between 15 and 300 years after last package emplacement (Stroupe 2000, Attachment 1, p. 1). The primary objectives of this analysis are to: (1) Review the design criteria as presented in the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a). The scope of this analysis will be limited to the instrumentation related to parameters that require continuous monitoring of the conditions underground. (2) Preliminary identification and listing of the data requirements and parameters as related to the current repository layout in support of PC monitoring. (3) Preliminary identification of methods and instrumentation for the acquisition of the required data. Although the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a) defines a broad range of data that must be obtained from a variety of methods, the focus of this analysis is on instrumentation related to the performance of the rock mass and the formation of water in the repository environment, that is obtainable from in-situ observation, testing, and monitoring

  20. PERFORMANCE CONFIRMATION IN-SITU INSTRUMENTATION

    N.T. Raczka

    2000-05-23

    The purpose of this document is to identify and analyze the types of in-situ instruments and methods that could be used in support of the data acquisition portion of the Performance Confirmation (PC) program at the potential nuclear waste repository at Yucca Mountain. The PC program will require geomechanical , geophysical, thermal, and hydrologic instrumentation of several kinds. This analysis is being prepared to document the technical issues associated with each type of measurement during the PC period. This analysis utilizes the ''Performance Confirmation Input Criteria'' (CRWMS M&O 1999a) as its starting point. The scope of this analysis is primarily on the period after the start of waste package emplacement and before permanent closure of the repository, a period lasting between 15 and 300 years after last package emplacement (Stroupe 2000, Attachment 1, p. 1). The primary objectives of this analysis are to: (1) Review the design criteria as presented in the ''Performance Confirmation Input Criteria'' (CRWMS M&O 1999a). The scope of this analysis will be limited to the instrumentation related to parameters that require continuous monitoring of the conditions underground. (2) Preliminary identification and listing of the data requirements and parameters as related to the current repository layout in support of PC monitoring. (3) Preliminary identification of methods and instrumentation for the acquisition of the required data. Although the ''Performance Confirmation Input Criteria'' (CRWMS M&O 1999a) defines a broad range of data that must be obtained from a variety of methods, the focus of this analysis is on instrumentation related to the performance of the rock mass and the formation of water in the repository environment, that is obtainable from in-situ observation, testing, and monitoring.

  1. In Situ Field Testing of Processes

    The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture monitoring using in-drift sensors or in-borehole sensors, to evaluate the impact of excavation, ventilation, and construction-water usage on the surrounding rocks. The liquid-release tests and air-injection tests provide an evaluation of in situ fracture flow and the competing processes of matrix imbibition. Only the findings from testing and data not covered in the ''Seepage Calibration Model and Seepage Testing Data'' are analyzed in detail in the AMR

  2. In situ permeability testing of rock salt

    Storage of transuranic (TRU) wastes in bedded salt formations requires a knowledge of the in situ permeability of SENM rock salt. Since assumptions for safety assessments have been made in which these wastes could generate gas pressures on the order of the lithostatic pressure over geologic time scales, the permeability of the surrounding formation becomes an important parameter for determining the manner in which the gases will be contained or dispersed. This report describes the series of tests conducted in the AEC-7 borehole, located near the WIPP site, to determine the in situ gas flow characteristics of the bedded salt. In these tests, compressed air was injected into the borehole and flow into the surrounding formation measured. These measured flow rates were interpreted in terms of formation permeabilities and porosities which were, in turn, used as modeling parameters for the repository response analysis. Two series of field tests were performed. The first series consisted of a number of whole-hole flow tests conducted to provide preliminary design information required for future operation of a guarded straddle packer system capable of measuring permeabilities > or = 0.1 ?darcy. The second series of tests were conducted using the Systems, Science and Software (S-Cubed) designed guarded straddle packer system. In these interval permeability tests, 100-foot lengths of borehole were isolated and the flow characteristics of the surrounding formation examined. In this report, a complete description of the test procedures, instrumentation, and measurement techniques is first given. The analytical/numerical methods used for data interpretation are then presented, followed by results of the interval and permeability tests. (The whole-hole tests are summarized in Appendix A.) Conclusions are presented in the final section

  3. In Situ Field Testing of Processes

    J. Wang

    2001-12-14

    The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture monitoring using in-drift sensors or in-borehole sensors, to evaluate the impact of excavation, ventilation, and construction-water usage on the surrounding rocks. The liquid-release tests and air-injection tests provide an evaluation of in situ fracture flow and the competing processes of matrix imbibition. Only the findings from testing and data not covered in the ''Seepage Calibration Model and Seepage Testing Data'' are analyzed in detail in the AMR.

  4. Studies on the intercalation of naproxen into layered double hydroxide and its thermal decomposition by in situ FT-IR and in situ HT-XRD

    Wei, Min; Shi, Shuxian; Wang, Ji; Li, Yong; Duan, Xue

    2004-07-01

    Layered double hydroxides, novel anionic clay, meet the first requirement as inorganic matrices for encapsulating functional drugs or biomolecules with negative charge in aqueous media. In this study, naproxen has been intercalated into Mg-Al layered double hydroxide by the methods of ion exchange. The structure and composition of the intercalated material have been studied by X-ray diffraction (XRD), UV-vis spectroscopy and inductively coupled plasma emission spectroscopy. A schematic model has been proposed. Furthermore, in situ Fourier transform infrared spectroscopy, in situ high-temperature XRD, and thermogravimetry (TG) have been used to characterize the thermal decomposition of the hybrid material. It has been found that the thermal stability of the intercalated naproxen is significantly enhanced compared with the pure form before intercalation, which suggests that this drug-inorganic layered material may have prospective application as the basis of a novel drug delivery system.

  5. Studies on the intercalation of naproxen into layered double hydroxide and its thermal decomposition by in situ FT-IR and in situ HT-XRD

    Layered double hydroxides, novel anionic clay, meet the first requirement as inorganic matrices for encapsulating functional drugs or biomolecules with negative charge in aqueous media. In this study, naproxen has been intercalated into Mg-Al layered double hydroxide by the methods of ion exchange. The structure and composition of the intercalated material have been studied by X-ray diffraction (XRD), UV-vis spectroscopy and inductively coupled plasma emission spectroscopy. A schematic model has been proposed. Furthermore, in situ Fourier transform infrared spectroscopy, in situ high-temperature XRD, and thermogravimetry (TG) have been used to characterize the thermal decomposition of the hybrid material. It has been found that the thermal stability of the intercalated naproxen is significantly enhanced compared with the pure form before intercalation, which suggests that this drug-inorganic layered material may have prospective application as the basis of a novel drug delivery system

  6. Economic analysis of open-pit and in situ mining

    Today, in any feasibility study of uranium properties, the project manager would be prudent to compare the economics of in situ methods with conventional surface and underground techniques. In this comparison of in situ and open-pit uranium mining, a group of hypothetical uranium deposits was evaluated, using the three most sensitive depositional characteristics of depth, size and grade. In situ mining was shown to challenge conventional open pit methods and, even at lower uranium recoveries, to yield higher profits

  7. An expert support model for in situ soil remediation

    Okx, J.P.; Stein, A. (Alwina)

    2000-01-01

    This article presents an expert support model for in situ soil remediation. It combines knowledge and experiences obtained from previous in situ soil remediations. The aim of this model is to optimise knowledge transfer among the various parties involved in contaminated site management. Structured Knowledge Engineering (SKE) has been used as a framework for model development. This approach requires scrutinising all relevant data to answer questions related to an in situ soil remediation opera...

  8. In-situ gelling polymers for biomedical applications

    2015-01-01

    This book presents the research involving in situ gelling polymers and can be used as a guidebook for academics, industrialists and postgraduates interested in this area. This work summaries the academic contributions from the top authorities in the field and explore the fundamental principles of in situ gelling polymeric networks, along with examples of their major applications. This book aims to provide an up-to-date resource of in situ gelling polymer research.

  9. A simplified in-situ electrochemical decontamination of lead from polluted soil (abstract)

    This paper reports a simplified In-Situ electrochemical method for remediation of field soil contaminated with lead. A series of electrochemical decontamination experiments including variable conditions such as operating duration and application of enhancement reagent were performed to demonstrate the efficiency of lead removal from spiked and polluted soil samples collected from Lahore, Pakistan. The results showed that the efficiency of lead removal from the contaminated soil increased with increasing the operating duration under a set of experimental conditions. The reagent used as complexing and solubilizing agent i.e. EDTA was found to be efficient in removing lead from the polluted soil. After 15 days duration, 85 % lead removal efficiency was observed in spiked soil under enhanced conditions , however, 63 % lead removal was achieved from the polluted soil samples by the simplified In-situ electrochemical decontamination method. The method is simple, rapid, cheaper and suitable for soil remediation purposes. (author)

  10. Melanoma "in situ" tratado con Imiquimod Melanoma in situ treated with Imiquimod

    RE Achenbach

    Full Text Available Comunicamos un caso con dos melanomas "in situ", en un varn de 86 aos, localizados en ambos lados de la cara con alto riesgo quirrgico, quien fuera tratado con imiquimod al 5% una vez al da durante dos meses; los resultados hasta el momento, clnicos e histolgicos han sido satisfactorios.A 86 years-old man with two melanomas "in situ" at both sides of his face, treated with imiquimod 5% are presented. The patient has a cardiovascular high risk due to isquemic heart disease, for that reason we start the treatment with imiquimod once a day for two months. The clinical and histological response was good and a follow up will be as long as we can.

  11. Osteogenic potential of in situ TiO2 nanowire surfaces formed by thermal oxidation of titanium alloy substrate

    Tan, A. W.; Ismail, R.; Chua, K. H.; Ahmad, R.; Akbar, S. A.; Pingguan-Murphy, B.

    2014-11-01

    Titanium dioxide (TiO2) nanowire surface structures were fabricated in situ by a thermal oxidation process, and their ability to enhance the osteogenic potential of primary osteoblasts was investigated. Human osteoblasts were isolated from nasal bone and cultured on a TiO2 nanowires coated substrate to assess its in vitro cellular interaction. Bare featureless Ti-6Al-4V substrate was used as a control surface. Initial cell adhesion, cell proliferation, cell differentiation, cell mineralization, and osteogenic related gene expression were examined on the TiO2 nanowire surfaces as compared to the control surfaces after 2 weeks of culturing. Cell adhesion and cell proliferation were assayed by field emission scanning electron microscope (FESEM) and Alamar Blue reduction assay, respectively. The nanowire surfaces promoted better cell adhesion and spreading than the control surface, as well as leading to higher cell proliferation. Our results showed that osteoblasts grown onto the TiO2 nanowire surfaces displayed significantly higher production levels of alkaline phosphatase (ALP), extracellular (ECM) mineralization and genes expression of runt-related transcription factor (Runx2), bone sialoprotein (BSP), ostoepontin (OPN) and osteocalcin (OCN) compared to the control surfaces. This suggests the potential use of such surface modification on Ti-6Al-4V substrates as a promising means to improve the osteointegration of titanium based implants.

  12. Dynamics of silver nanoparticle release from wound dressings revealed via in situ nanoscale imaging

    Holbrook, R. David; Rykaczewski, Konrad; Staymates, Matthew E.

    2014-01-01

    The use of silver nanoparticles (AgNPs) in textiles for enhanced anti-microbial properties has led to concern about their release and impact on both human and environmental health. Here a novel method for in situ visualization of AgNP release from silver-impregnated wound dressings is introduced. By combining an environmental scanning electron microscope, a gaseous analytical detector and a peltier cooling stage, this technique provides near-instantaneous nanoscale characterization of interac...

  13. Fluorescence in situ hybridization in combination with the comet assay and micronucleus test in genetic toxicology

    Hovhannisyan Galina G

    2010-01-01

    Abstract Comet assay and micronucleus (MN) test are widely applied in genotoxicity testing and biomonitoring. While comet assay permits to measure direct DNA-strand breaking capacity of a tested agent MN test allows estimating the induced amount of chromosome and/or genome mutations. The potential of these two methods can be enhanced by the combination with fluorescence in situ hybridization (FISH) techniques. FISH plus comet assay allows the recognition of targets of DNA damage and repairing...

  14. Oriented Arrays of Graphene in a Polymer Matrix by in situ Reduction of Graphite Oxide Nanosheets

    Ansari, Seema

    2010-01-18

    Graphite oxide-Nafion hybrids with a high degree of alignment are cast from aqueous solution in the absence of any external field and reduced in situ by exposure to hydrazine to produce graphene-Nafion hybrids. Dramatic enhancement of electrical conductivity indicates sufficient accessibility of the inorganic nanosheets to the reducing agent, through the nanochannels formed by the polymeric ionic domains. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

  15. IN-SITU TRITIUM BETA DETECTOR

    J.W. Berthold; L.A. Jeffers

    1998-04-15

    The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector that would use the fluor-doped fibers as primary sensors of tritium concentration in water. The major conclusions from the characterization work are: A polystyrene optical fiber with fluor dopant concentration of 2% gave best performance. This fiber had the highest dopant concentration of any fibers tested. Stability may be a problem. The fibers exposed to a 22-day soak in 120 F water experienced a 10x reduction in sensitivity. It is not known whether this was due to the build up of a deposit (a potentially reversible effect) or an irreversible process such as leaching of the scintillating dye. Based on the results achieved, it is premature to initiate Phase 2 and commit to a prototype design for construction and test. Significant improvements must be made in fluor-doped fiber performance in order to use the method for in situ monitoring to verify compliance with current EPA drinking water standards. Additional Phase 1 fiber development work should be performed to increase the fluor dopant concentration above 2% until the self-absorption limit is observed. Continued fiber optimization work is expected to improve the sensitivity limits, and will enable application of the detector to verify compliance with the US EPA drinking water standard of 20,000 pico Curies per liter. However, if the need for monitoring higher levels of tritium in water at concentrations greater than 200,000 pico Curies per liter is justified, then prototype development and testing could proceed either as a Phase 2 stand-alone effort or in parallel with continued Phase 1 development work.

  16. IN-SITU TRITIUM BETA DETECTOR

    The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector that would use the fluor-doped fibers as primary sensors of tritium concentration in water. The major conclusions from the characterization work are: A polystyrene optical fiber with fluor dopant concentration of 2% gave best performance. This fiber had the highest dopant concentration of any fibers tested. Stability may be a problem. The fibers exposed to a 22-day soak in 120 F water experienced a 10x reduction in sensitivity. It is not known whether this was due to the build up of a deposit (a potentially reversible effect) or an irreversible process such as leaching of the scintillating dye. Based on the results achieved, it is premature to initiate Phase 2 and commit to a prototype design for construction and test. Significant improvements must be made in fluor-doped fiber performance in order to use the method for in situ monitoring to verify compliance with current EPA drinking water standards. Additional Phase 1 fiber development work should be performed to increase the fluor dopant concentration above 2% until the self-absorption limit is observed. Continued fiber optimization work is expected to improve the sensitivity limits, and will enable application of the detector to verify compliance with the US EPA drinking water standard of 20,000 pico Curies per liter. However, if the need for monitoring higher levels of tritium in water at concentrations greater than 200,000 pico Curies per liter is justified, then prototype development and testing could proceed either as a Phase 2 stand-alone effort or in parallel with continued Phase 1 development work

  17. Debottlenecking product inhibition in 1,3-propanediol fermentation by In-Situ Product Recovery.

    Kaur, Guneet; Srivastava, A K; Chand, Subhash

    2015-12-01

    The present work describes the application of liquid-liquid extraction as an In-Situ product recovery (ISPR) technique to overcome the problem of product inhibition in 1,3-PD fermentation. As a part of initial screening experiments, six solvents were subjected to phase separation and biocompatibility tests to find the best extractant for in-situ removal of 1,3-PD from the bioreactor. These included tributylphosphate, ethyl acetate, butyl acetate, oleyl alcohol, oleic acid and hexanol. Of these, ethyl acetate was found to be the most suitable solvent for 1,3-PD extraction. Use of the selected extractant in continuous integrated fermentation-extraction was established by batch and fed-batch extractive fermentations which demonstrated a significantly improved 1,3-PD production of 35g/L and 74.5g/L, respectively. A steady state 1,3-PD concentration of 58g/L was obtained in continuous extractive system. Continuous cultivation with in-situ cell retention and in-situ 1,3-PD removal demonstrated a 5-fold enhancement in 1,3-PD productivity over non-extractive batch. PMID:26356117

  18. Preparation and characterization of electrospun in-situ cross-linked gelatin-graphite oxide nanofibers.

    Zhan, Jianchao; Morsi, Yosry; Ei-Hamshary, Hany; Al-Deyab, Salem S; Mo, Xiumei

    2016-04-01

    Electrospun gelatin(Gel) nanofibers scaffold has such defects as poor mechanical property and quick degradation due to high solubility. In this study, the in situ cross-linked electrospinning technique was used for the production of gelatin nanofibers. Deionized water was chosen as the spinning solvent and graphite oxide (GO) was chosen as the enhancer. The morphological structure, porosity, thermal property, moisture absorption, and moisture retention performance, hydrolysis resistance, mechanical property, and biocompatibility of the produced nanofibers were investigated. Compared with in situ cross-linked gelatin nanofibers scaffold, in situ cross-linked Gel-GO nanofibers scaffold has the following features: (1) the hydrophilicity, moisture absorption, and moisture retention performance slightly reduce, while the hydrolysis resistance is improved; (2) the breaking strength, breaking elongation, and Young's modulus are significantly improved; (3) the porosity slightly reduces while the biocompatibility considerably increases. The in situ cross-linked Gel-GO nanofibers scaffold is likely to be applied in such fields as drug delivery and scaffold for skin tissue engineering. PMID:26733331

  19. In situ gas-phase hydrosilylation of plasma-synthesized silicon nanocrystals.

    Jariwala, Bhavin N; Dewey, Oliver S; Stradins, Paul; Ciobanu, Cristian V; Agarwal, Sumit

    2011-08-01

    Surface passivation of semiconductor nanocrystals (NCs) is critical in enabling their utilization in novel optoelectronic devices, solar cells, and biological and chemical sensors. Compared to the extensively used liquid-phase NC synthesis and passivation techniques, gas-phase routes provide the unique opportunity for in situ passivation of semiconductor NCs. Herein, we present a method for in situ gas-phase organic functionalization of plasma-synthesized, H-terminated silicon (Si) NCs. Using real-time in situ attenuated total reflection Fourier transform IR spectroscopy, we have studied the surface reactions during hydrosilylation of Si NCs at 160 °C. First, we show that, during gas-phase hydrosilylation of Si NCs using styrene (1-alkene) and acetylene (alkyne), the reaction pathways of the alkenes and alkynes chemisorbing onto surface SiH(x) (x = 1-3) species are different. Second, utilizing this difference in reactivity, we demonstrate a novel pathway to enhance the surface ligand passivation of Si NCs via in situ gas-phase hydrosilylation using the combination of a short-chain alkyne (acetylene) and a long-chain 1-alkene (styrene). The quality of surface passivation is further validated through IR and photoluminescence measurements of Si NCs exposed to air. PMID:21774486

  20. Numerical study on in-situ leaching uranium with pressure fluctuation

    Recent researches and innovation of in-situ leaching focus on the chemical process, which can not solve the low recovery in 'dead leaching zone' and 'non-preferential zone' caused by preferential flow and solute transport phenomena in heterogeneous ore deposits. Based on hydrodynamic effects and phenomena in highly heterogeneous porous media, gas injection experiments and laboratory experiment results, an innovative method for in-situ leaching, named as leaching with pressure fluctuation, was put forward to enhance the leaching effect and uranium recovery, especially in those uranium ore deposits with high heterogeneity. Based on the characteristics of gas/liquid mixture and flow-reactive-transport theory, a numerical modeling tool is established. By the numerical simulation, the field-scale traditional leaching method and the new method were studied. The simulation results show that the gas-liquid mixture will expand/shrink greatly in different flow zone during the pressure fluctuation process, and the deformation will enhance the solute transport effect among different flow zones, especially in non-preferential flow zone, and enhance the uranium recovery. The primary results show that in-situ leaching with pressure fluctuation is feasible technically. (authors)

  1. Elective caesarean section at 38 weeks versus 39 weeks

    Glavind, Julie; Kindberg, S F; Uldbjerg, N; Khalil, Mohammed; Møller, A M; Mortensen, B B; Rasmussen, O B; Christensen, J T; Jørgensen, J S; Henriksen, T B

    2013-01-01

    To investigate whether elective caesarean section before 39 completed weeks of gestation increases the risk of adverse neonatal or maternal outcomes.......To investigate whether elective caesarean section before 39 completed weeks of gestation increases the risk of adverse neonatal or maternal outcomes....

  2. Innovative technologies for in-situ remediation

    LLNL is developing several innovative remediation technologies as long-term improvements to the current pump and treat approaches to cleaning up contaminated soils and groundwater. These technologies include dynamic underground stripping, in-situ microbial filters, and remediation using bremsstrahlung radiation. Concentrated underground organic contaminant plumes are one of the most prevalent groundwater contamination sources. The solvent or fuel can percolate deep into the earth, often into water-bearing regions. Collecting as a separate, liquid organic phase called dense non-aqueous-phase liquids (DNAPLs), or light NAPLs (LNAPLs), these contaminants provide a source term that continuously compromises surrounding groundwater. This type of spill is one of the most difficult environmental problems to remediate. Attempts to remove such material requires a huge amount of water which must be washed through the system to clean it, requiring decades. Traditional pump and treat approaches have not been successful. LLNL has developed several innovative technologies to clean up NAPL contamination. Detailed descriptions of these technologies are given

  3. Backfilling of deposition tunnels, in situ alternative

    The backfilling process described in this report is based on in situ compaction of a mixture of bentonite and ballast (30:70) into the deposition tunnel. This method has been tested in practice in various field tests by SKB, most recently in the Prototype repository test performed at Aespoe HRL. The backfill mixture is prepared above ground and transported to the repository level with a tank truck. The material is compacted into layers with an inclination of 35 deg C and a thickness of approximately 20 cm. The compaction is performed with a vibratory plate attached to a boom of an excavator. In order to keep up with the required canister installation rate determined for the Finnish repository, at least 13 layers need to be compacted daily. This means working in 2-3 shifts on the working days that are available for backfilling operations. The dry densities achieved in field tests for the wall/roof section of the backfill have been insufficient compared with the dry density criteria set for the backfill. In theory, it may be possible to reach dry densities that fulfil the criteria, although with a relatively small safety margin. Another open issue is whether the mixture of bentonite and ballast has sufficient self-healing ability to seal-off erosion channels after the tunnels have been closed and the backfill has reached full saturation. (orig.)

  4. In-situ heat transfer experiment (ISHTE)

    The Applied Physics Laboratory (APL) of the University of Washington is building and testing equipment to support in-situ heat transfer experiment (ISHTE). This experiment will implant a heat source in the clay sediments of the deep ocean and monitor the effects of the heat on the sediment for one year. At the end of the experiment the equipment and samples of the heat-affected sediment will be recovered for study. The experiment is part of the near-field studies in the Subseabed Disposal Program. APL is in the equipment design and testing phase of the project. Major tasks this year have been focused toward two field activities. The first was an oceanographic cruise aboard the USNS De Steiguer at MPG-I during May. The main objectives of the cruise were to recover a mooring deployed in 1980, to test a hydrostatic corer and to evaluate the acoustic data transmission system. The second activity was a scale model test of ISHTE in a pressure chamber at the David Taylor Naval Ship Research and Development Center at Annapolis, Maryland, during the last quarter of 1981

  5. Cubesat in-situ degradation detector (CIDD)

    Rievers, Benny; Milke, Alexander; Salden, Daniel

    2015-07-01

    The design of the thermal control and management system (TCS) is a central task in satellite design. In order to evaluate and dimensionize the properties of the TCS, material parameters specifying the conductive and radiative properties of the different TCS components have to be known including their respective variations within the mission lifetime. In particular the thermo-optical properties of the outer surfaces including critical TCS components such as radiators and thermal insulation are subject to degradation caused by interaction with the space environment. The evaluation of these material parameters by means of ground testing is a time-consuming and expensive endeavor. Long-term in-situ measurements on board the ISS or large satellites not only realize a better implementation of the influence of the space environment but also imply high costs. Motivated by this we propose the utilization of low-cost nano-satellite systems to realize material tests within space at a considerably reduced cost. We present a nanosat-scale degradation sensor concept which realizes low power consumption and data rates compatible with nanosat boundaries at UHF radio. By means of a predefined measurement and messaging cycle temperature curves are measured and evaluated on ground to extract the change of absorptivity and emissivity over mission lifetime.

  6. In situ vitrification of radioactive underground tanks

    Koegler, S.S.; Gibby, R.D.; Thompson, L.E.

    1991-10-01

    In situ vitrification (ISV) is a treatment process with great potential for remediating underground tanks previously used for storing radioactive and hazardous chemical wastes at US Department of Energy (DOE) sites. Tests at several scales have demonstrated the utility of ISV for these tanks. An engineering-scale test vitrified a 30-cm-diameter buried steel and concrete tank that contained simulated tank sludge. Hazardous components of the tank sludge were immobilized, or removed and captured in the off-gas treatment system, and the tank walls were melted or incorporated into the ISV block. A pilot-scale ISV test vitrified a 1-m simulated underground tank than contained a simulated refractory sludge. The ISV process completely vitrified the tank, its contents, and the soil below the tank to a depth of 2.4 m, producing a uniform glass and crystalline monolith with an estimated mass of 30 tons. A large-scale underground tank test is scheduled for early 1991. 5 refs., 4 figs.

  7. In Situ and Satellite Measured Temperature Comparability

    Schmidlin, F. J.; Goldberg, R. A.; Bedrick, M.; Rose, R.

    2011-12-01

    Following the International Geophysical Year in the late 1950's, small meteorological rockets caught the interest of scientists as a potentially inexpensive method to obtain meteorological information (density, temperature, wind) above balloon-borne radiosonde altitudes. These small rocketsondes have served many important observational roles in terms of studies conducted of atmospheric structure and processes, enabling many new ideas about the atmosphere to emerge. Although no longer manufactured a small residual inventory of meteorological rocketsondes exist for specific research projects. The value of data from meteorological rocketsondes is without question but with their disappearance data from many different satellites are filling the need, some able to resolve high-altitude temperatures quite well. However, the rocketsonde vertical profile is more localized to the launch site whereas satellites move several kilometers per second. The objective of this presentation is to compare in situ temperature data with remotely measured/retrieved temperature data. There have been a number of U.S. conducted missions utilizing the passive falling sphere data that we use to verify the comparability of retrieved temperatures from these satellites. Missions, some as early as 1991, were conducted in polar, equatorial, and mid-latitude locations. An important aspect is that a single satellite profile compared to a falling sphere profile often does not agree while high density satellite measurements when averaged over an area near the rocketsonde data area seems to be in better agreement. Radiosonde temperature data are used in the analysis when appropriate.

  8. Photonic MEMS for NIR in-situ

    Bond, T C; Cole, G D; Goddard, L L; Behymer, E

    2007-07-03

    We report on a novel sensing technique combining photonics and microelectromechanical systems (MEMS) for the detection and monitoring of gas emissions for critical environmental, medical, and industrial applications. We discuss how MEMS-tunable vertical-cavity surface-emitting lasers (VCSELs) can be exploited for in-situ detection and NIR spectroscopy of several gases, such as O{sub 2}, N{sub 2}O, CO{sub x}, CH{sub 4}, HF, HCl, etc., with estimated sensitivities between 0.1 and 20 ppm on footprints {approx}10{sup -3} mm{sup 3}. The VCSELs can be electrostatically tuned with a continuous wavelength shift up to 20 nm, allowing for unambiguous NIR signature determination. Selective concentration analysis in heterogeneous gas compositions is enabled, thus paving the way to an integrated optical platform for multiplexed gas identification by bandgap and device engineering. We will discuss here, in particular, our efforts on the development of a 760 nm AlGaAs based tunable VCSEL for O{sub 2} detection.

  9. An overview of in situ waste treatment technologies

    In situ technologies are becoming an attractive remedial alternative for eliminating environmental problems. In situ treatments typically reduce risks and costs associated with retrieving, packaging, and storing or disposing-waste and are generally preferred over ex situ treatments. Each in situ technology has specific applications, and, in order to provide the most economical and practical solution to a waste problem, these applications must be understood. This paper presents an overview of thirty different in situ remedial technologies for buried wastes or contaminated soil areas. The objective of this paper is to familiarize those involved in waste remediation activities with available and emerging in situ technologies so that they may consider these options in the remediation of hazardous and/or radioactive waste sites. Several types of in situ technologies are discussed, including biological treatments, containment technologies, physical/chemical treatments, solidification/stabilization technologies, and thermal treatments. Each category of in situ technology is briefly examined in this paper. Specific treatments belonging to these categories are also reviewed. Much of the information on in situ treatment technologies in this paper was obtained directly from vendors and universities and this information has not been verified

  10. Zebrafish Whole-Mount In Situ Hybridization Followed by Sectioning

    Doganli, Canan; Nyengaard, Jens Randel; Lykke-Hartmann, Karin

    2016-01-01

    In situ hybridization is a powerful technique used for locating specific nucleic acid targets within morphologically preserved tissues and cell preparations. A labeled RNA or DNA probe hybridizes to its complementary mRNA or DNA sequence within a sample. Here, we describe RNA in situ hybridization...

  11. Some implications of in situ uranium mining technology development

    A technology assessment was initiated in March 1979 of the in-situ uranium mining technology. This report explores the impediments to development and deployment of this technology and evaluates the environmental impacts of a generic in-situ facility. The report is divided into the following sections: introduction, technology description, physical environment, institutional and socioeconomic environment, impact assessment, impediments, and conclusions

  12. In situ detection of horizontal transfer of mobile genetic elements

    Haagensen, Janus Anders Juul; Hansen, Susse Kirkelund; Johansen, Tove; Molin, Søren

    2002-01-01

    , was used to monitor bacterial growth activity in situ. Differential tagging of mobilizing and mobilizable plasmids with different genes encoding fluorescent proteins with varying emission wavelengths allowed in situ detection of plasmid mobilization and detection of retro-transfer on agar surfaces...... donor/recipient positioning, cellular activity and appearance of transconjugants....

  13. Development of the integrated in situ Lasagna process

    Contamination in deep, low permeability soils poses a significant technical challenge to in-situ remediation efforts. Poor accessibility to the contaminants and difficulty in uniform delivery of treatment reagents have rendered existing in-situ methods such as bioremediation, vapor extraction, and pump and treat rather ineffective when applied to low permeability soils present at many contaminated sites

  14. Some implications of in situ uranium mining technology development

    Cowan, C.E.; Parkhurst, M.A.; Cole, R.J.; Keller, D.; Mellinger, P.J.; Wallace, R.W.

    1980-09-01

    A technology assessment was initiated in March 1979 of the in-situ uranium mining technology. This report explores the impediments to development and deployment of this technology and evaluates the environmental impacts of a generic in-situ facility. The report is divided into the following sections: introduction, technology description, physical environment, institutional and socioeconomic environment, impact assessment, impediments, and conclusions. (DLC)

  15. An overview of in situ waste treatment technologies

    Walker, S.; Hyde, R.A.; Piper, R.B.; Roy, M.W.

    1992-08-01

    In situ technologies are becoming an attractive remedial alternative for eliminating environmental problems. In situ treatments typically reduce risks and costs associated with retrieving, packaging, and storing or disposing-waste and are generally preferred over ex situ treatments. Each in situ technology has specific applications, and, in order to provide the most economical and practical solution to a waste problem, these applications must be understood. This paper presents an overview of thirty different in situ remedial technologies for buried wastes or contaminated soil areas. The objective of this paper is to familiarize those involved in waste remediation activities with available and emerging in situ technologies so that they may consider these options in the remediation of hazardous and/or radioactive waste sites. Several types of in situ technologies are discussed, including biological treatments, containment technologies, physical/chemical treatments, solidification/stabilization technologies, and thermal treatments. Each category of in situ technology is briefly examined in this paper. Specific treatments belonging to these categories are also reviewed. Much of the information on in situ treatment technologies in this paper was obtained directly from vendors and universities and this information has not been verified.

  16. An overview of in situ waste treatment technologies

    Walker, S.; Hyde, R.A.; Piper, R.B.; Roy, M.W.

    1992-01-01

    In situ technologies are becoming an attractive remedial alternative for eliminating environmental problems. In situ treatments typically reduce risks and costs associated with retrieving, packaging, and storing or disposing-waste and are generally preferred over ex situ treatments. Each in situ technology has specific applications, and, in order to provide the most economical and practical solution to a waste problem, these applications must be understood. This paper presents an overview of thirty different in situ remedial technologies for buried wastes or contaminated soil areas. The objective of this paper is to familiarize those involved in waste remediation activities with available and emerging in situ technologies so that they may consider these options in the remediation of hazardous and/or radioactive waste sites. Several types of in situ technologies are discussed, including biological treatments, containment technologies, physical/chemical treatments, solidification/stabilization technologies, and thermal treatments. Each category of in situ technology is briefly examined in this paper. Specific treatments belonging to these categories are also reviewed. Much of the information on in situ treatment technologies in this paper was obtained directly from vendors and universities and this information has not been verified.

  17. In situ monitoring of liquid phase electroepitaxial growth

    Okamoto, A.; Isozumi, S.; Lagowski, J.; Gatos, H. C.

    1982-01-01

    In situ monitoring of the layer thickness during liquid phase electroepitaxy (LPEE) was achieved with a submicron resolution through precise resistance measurements. The new approach to the study and control of LPEE was applied to growth of undoped and Ge-doped GaAs layers. The in situ determined growth kinetics was found to be in excellent agreement with theory.

  18. CGS and In Situ Measurements in Gävle 1999

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim

    1999-01-01

    Calibration of CGS-equipment.In situ measuremts with HPGe-detector (and dose rate meter)in Gävle Sweden as part of the Nordic exercise RESUME99.......Calibration of CGS-equipment.In situ measuremts with HPGe-detector (and dose rate meter)in Gävle Sweden as part of the Nordic exercise RESUME99....

  19. Applications of in situ optical measurements in ecological and biogeochemical studies - a framework for a user-driven national network

    Bergamaschi, B. A.; Pellerin, B. A.; Downing, B. D.; Saraceno, J.; Aiken, G.; Stumpner, P.

    2010-12-01

    A critical challenge for understanding the dynamics between water quality, and ecological processes is obtaining data at time scales in which changes occur. Traditional, discrete sampling, approaches for data collection are often limited by analytical and field costs, site access, and logistical challenges, for long-term sampling at a large number of sites. The timescales of change, however, are often minutes, hours, or years. In situ optical (absorbance and fluorescence) instruments offer opportunities to help overcome these difficulties by directly or indirectly measuring constituents of interest. In situ optical instrumentation have been in use in oceanographic studies for well over 50 years, and as advances in the science, engineering and technology of these sensors have improved, optical sensors have become more commercially viable and available for research. We present several examples that highlight applications of in situ optical measurements for understanding dynamics in stream, river, and estuary systems. Examples illustrate the utility of in situ optical sensors for studies over short-duration events of days to weeks (diurnal cycles, tidal cycles, storm events and snowmelt periods) as well as longer-term continuous monitoring for months to years. We also highlight applied in situ optical measurements as proxies for constituents that are difficult and expensive to measure at high spatiotemporal resolution, for example, dissolved organic carbon, dissolved organic nitrogen, mercury and methylmercury, trihalomethane precursors, harmful algal blooms, and others. We propose that relatively simple absorbance and fluorescence measurements made in situ could be incorporated into short and long-term ecological research and monitoring programs, resulting in advanced understanding of sources that contribute to water quality improvements or degradation, contaminant and carbon cycling, and the occurrence and persistence of harmful algal blooms. Linking these efforts through common calibration and validation techniques, as well as hosted data sharing and online user forums - as has been proposed by CUAHSI and USGS - will permit more rapid advances in applications of in situ optical sensors as well as in our understanding of aquatic processes.

  20. In situ containment and stabilization of buried waste

    Allan, M.L.; Kukacka, L.E.; Heiser, J.H.

    1992-11-01

    The objective of the project was to develop, demonstrate and implement advanced grouting materials for the in-situ installation of impermeable, durable subsurface barriers and caps around waste sites and for the in-situ stabilization of contaminated soils. Specifically, the work was aimed at remediation of the Chemical Waste (CWL) and Mixed Waste Landfills (MWL) at Sandia National Laboratories (SNL) as part of the Mixed Waste Landfill Integrated Demonstration (MWLID). This report documents this project, which was conducted in two subtasks. These were (1) Capping and Barrier Grouts, and (2) In-situ Stabilization of Contaminated Soils. Subtask 1 examined materials and placement methods for in-situ containment of contaminated sites by subsurface barriers and surface caps. In Subtask 2 materials and techniques were evaluated for in-situ chemical stabilization of chromium in soil.

  1. A NOVEL OPHTHALMIC DRUG DELIVERY SYSTEM: IN-SITU GEL

    A.P. Patil*, A.A. Tagalpallewar, G.M. Rasve, A.V. Bendre, P.G. Khapekar

    2012-09-01

    Full Text Available The ophthalmic in-situ gels now days proved an palpable sustained drug delivery in various eye diseases. The formulation of in-situ gels for eye which carries the advantages like easy for administration, reduces frequency of dose and improves patient compliance. The formation of in-situ gels depends on phase transition system or sol-gel transition system. The formulation approaches like temperature intonation, pH change and presence of ions from which the drug gets released in a sustained and controlled manner are utilised for in-situ gels. Various polymers that are used for the formulation of in-situ gels include chitosan, Pluronic F-127, poly-caprolactone, gellan gum, alginic acid, xyloglucan, pectin etc.

  2. Reconstruction of Traumatic Bone Defect With In Situ Implantation of Dropped Traumatic Segmental Bone Fragments.

    Lin, Dasheng; Luo, Deqing; Lian, Kejian; Zhai, Wenliang; Ding, Zhenqi

    2016-01-01

    This study was conducted to determine whether in situ implantation of a dropped traumatic segmental bone fragment is safe and whether the authors' method would reduce the incidence of infectious and related complications. The authors retrospectively reviewed 16 patients with open fractures, including 11 with Gustilo-Anderson type IIIA fractures and 5 with Gustilo-Anderson type IIIB fractures who had a dropped traumatic segmental bone fragment between January 2002 and January 2012. Mean patient age was 35.4 years (range, 19-47 years). There were 10 femurs and 6 tibias. Average postoperative follow-up was 26.8 months (range, 12-60 months). The dropped traumatic segmental bone fragments were cleaned with 3% hydrogen peroxide, placed in separate sterile cups, and soaked in 1% iodophor for 30 minutes. Initial treatment included surgical debridement, wound irrigation, in situ implantation of the dropped traumatic segmental bone fragment, and temporary external fixation. Approximately 4 to 8 weeks later, after successful reconstruction of the soft tissue envelope, minimally invasive plate osteosynthesis was performed. Mean duration of treatment was 8 weeks (range, 6-14 weeks). All patients had fracture union at final follow-up. Mean healing time was 21.8 weeks (range, 14-48 weeks). One patient did not achieve primary union and required bone grafting. One patient with a Gustilo-Anderson type IIIB fracture had deep infection and removal of the dropped traumatic segmental bone fragment and bone grafting. According to the Klemm and Börner classification, 11 patients had excellent results, 3 had good results, and 2 had poor results. With adequate soft tissue coverage, this method was acceptable for the management of open fractures with bone defects. [Orthopedics. 2016; 39(1):e14-e18.]. PMID:26709568

  3. Common In-Situ Consumable Production Plant for Robotic Mars Exploration

    Sanders, G. B.; Trevathan, J. R.; Peters, T. A.; Baird, R. S.

    2000-01-01

    Utilization of extraterrestrial resources, or In-Situ Resource Utilization (ISRU), is viewed by the Human Exploration and Development of Space (HEDS) Enterprise as an enabling technology for the exploration and commercial development of space. A key subset of ISRU which has significant cost, mass, and risk reduction benefits for robotic and human exploration, and which requires a minimum of infrastructure, is In-Situ Consumable Production (ISCP). ISCP involves acquiring, manufacturing, and storing mission consumables from in situ resources, such as propellants, fuel cell reagents, and gases for crew and life support, inflation, science and pneumatic equipment. One of the four long-term goals for the Space Science Enterprise (SSE) is to 'pursue space science programs that enable and are enabled by future human exploration beyond low-Earth orbit - a goal exploiting the synergy with the human exploration of space'. Adequate power and propulsion capabilities are critical for both robotic and human exploration missions. Minimizing the mass and volume of these systems can reduce mission cost or enhance the mission by enabling the incorporation of new science or mission-relevant equipment. Studies have shown that in-situ production of oxygen and methane propellants can enhance sample return missions by enabling larger samples to be returned to Earth or by performing Direct Earth Return (DER) sample return missions instead of requiring a Mars Orbit Rendezvous (MOR). Recent NASA and Department of Energy (DOE) work on oxygen and hydrocarbon-based fuel cell power systems shows the potential of using fuel cell power systems instead of solar arrays and batteries for future rovers and science equipment. The development and use of a common oxygen/methane ISCP plant for propulsion and power generation can extend and enhance the scientific exploration of Mars while supporting the development and demonstration of critical technologies and systems for the human exploration of Mars.

  4. Reinforcement of nitrile rubber by in situ formed zinc disorbate

    2010-09-01

    Full Text Available Zinc disorbate (ZDS was in situ formed by the reaction between sorbic acid (SA and zinc oxide (ZnO in nitrile rubber (NBR. The effects of SA amount on the curing characteristics, crosslink density and mechanical properties of peroxide- cured NBR were studied. The results showed that ZDS was generated mainly during the rubber vulcanization, rather than the open mill compounding phase. The results from the crosslink density determinations showed that the formation of ZDS significantly increased the ionic bond content in the vulcanizates. In addition, the formation of ZDS greatly enhanced the mechanical properties of NBR vulcanizates. The modulus, tensile strength, tear strength and hardness were found to be increased with the loading of ZDS. Preheating the compounds before compression moulding was beneficial to the formation of ZDS, and consequently the increases in mechanical properties. At 40 parts per hundred rubber (phr of SA and 16 phr ZnO, five to six folds of tensile strength and tear strength of the neat NBR vulcanizate were achieved. Transmission electron microscopy (TEM results confirmed the nano-dispersion structure of the polymerized ZDS in the NBR matrix.

  5. In situ recycling of contaminated soil uses bioremediation

    OxyChem Pipeline Operations, primarily an ethylene and propylene products mover, has determined that substantial savings can be realized by adopting a bioremediation maintenance and recycling approach to hydrocarbon-contaminated soil. By this method, the soil can be recycled in situ, or in containers. To implement the soil-recycling program, OxyChem elected to use a soil remediator and natural absorbent product, Oil Snapper. This field maintenance material, based on an Enhanced Urea Technology, provides a diet to stimulate the growth of hydrocarbon-eating microbes. It works well either with indigenous soil microbes or with commercial microbes. The product is carried in field vehicles, which makes it immediately available when leaks or spills are discovered. Procedure for clean-up is to apply product and mix it into affected soil. Thus the contaminant is contained, preventing further migration; the contaminant is dispersed throughout the product, making it more accessible to the microbes; nutrients are immediately available to the microbes; and the material contributes aeration and moisture-retention properties

  6. In situ treatment of VOCs by recirculation technologies

    The project described herein was conducted by Oak Ridge National Laboratory (ORNL) to identify processes and technologies developed in Germany that appeared to have near-term potential for enhancing the cleanup of volatile organic compound (VOC) contaminated soil and groundwater at DOE sites. Members of the ORNL research team identified and evaluated selected German technologies developed at or in association with the University of Karlsruhe (UoK) for in situ treatment of VOC contaminated soils and groundwater. Project activities included contacts with researchers within three departments of the UoK (i.e., Applied Geology, Hydromechanics, and Soil and Foundation Engineering) during fall 1991 and subsequent visits to UoK and private industry collaborators during February 1992. Subsequent analyses consisted of engineering computations, groundwater flow modeling, and treatment process modeling. As a result of these project efforts, two processes were identified as having near-term potential for DOE: (1) the vacuum vaporizer well/groundwater recirculation well and (2) the porous pipe/horizontal well. This document was prepared to summarize the methods and results of the assessment activities completed during the initial year of the project. The project is still ongoing, so not all facets of the effort are completely described in this document. Recommendations for laboratory and field experiments are provided

  7. Comparing in situ removal strategies for improving styrene bioproduction.

    McKenna, Rebekah; Moya, Luis; McDaniel, Matthew; Nielsen, David R

    2015-01-01

    As an important conventional monomer compound, the biological production of styrene carries significant promise with respect to creating novel sustainable materials. Since end-product toxicity presently limits styrene production by previously engineered Escherichia coli, in situ product removal by both solvent extraction and gas stripping were explored as process-based strategies for circumventing its inhibitory effects. In solvent extraction, the addition of bis(2-ethylhexyl)phthalate offered the greatest productivity enhancement, allowing net volumetric production of 83664mg/L to be reached, representing a 320% improvement over single-phase cultures. Gas stripping rates, meanwhile, were controlled by rates of bioreactor agitation and, to a greater extent, aeration. A periodic gas stripping protocol ultimately enabled up to 56115mg/L styrene to be attained. Lastly, by relieving the effects of styrene toxicity, new insight was gained regarding subsequent factors limiting its biosynthesis in E. coli and strategies for future strain improvement are discussed. PMID:25034182

  8. In situ radionuclide transfers in the deep-sea Lysianassidae amphipod Eurythenes gryllus

    Previous studies at the NEA dumpsite confirmed the existence of the scavenging amphipod Eurythenes gryllus. The aim of this study was to inquire if, under deep-sea conditions of low temperature and high pressure, this species of crustacean would retain artificial radionuclides in the same organ as those observed in similar coastal species of the same family. This necrophagous species is easily attracted by bait. It can ingest 30 to 60% of its body weight in 30 ± 10 min. In addition, this species can store ingested food for several weeks. Thus, the ingestion of radiolabelled food over a period of several days could be considered as a single-meal contamination experiment. For all these reasons Eurythenes gryllus appeared to be a good test animal to compare laboratory experiments on coastal species with in situ radionuclide retention studies on deep-sea fauna. In order to prevent any disturbance of their physiological conditions, a special device was used to attract and feed the animals with radiolabelled baits, in situ at a depth of 4000 m, rather than recovering amphipods without decompression and keeping them alive aboard ship. Qualitatively speaking results yielded by in situ experiments support those obtained from laboratory studies with coastal animals and the same radionuclides

  9. Ecological impact assessment of metallurgic effluents using in situ biomarker assays

    An ecological impact study was performed based on in situ biomarker assays with the waterflea Daphnia magna. The effects of metallurgic effluents on the energy metabolism, anti-oxidative metabolism and DNA damage were assessed in caged daphnids during a 4-week study. In situ survival and reproduction studies demonstrated a clear impact on these parameters in organisms exposed in the most polluted areas. At the downstream-sublethal-zone the organisms were disturbed within their tolerance limits, resulting in alterations of their energy metabolism. These data suggest an acclimation hypothesis, which was tested through the analysis of the energy metabolism of resident species: isopods and amphipods. These organisms had shifted to a decrease in their overall energy metabolism compared to the upstream region. This change in some biochemical processes suggests a selective advantage to cope with the prevailing environmental conditions. In addition, we found clear genotoxic effects caused by the industrial discharges that might correlate with a reduction in (long-term) survival. - In situ monitoring of metallurgic effluents using biomarker analysis

  10. In situ X-ray investigations of oxygen precipitation in semiconductor silicon; In-situ-Roentgenuntersuchungen der Sauerstoffpraezipitation in Halbleitersilizium

    Grillenberger, Hannes

    2011-03-04

    The precipitation of oxygen in Czochralski grown semiconductor silicon is investigated in situ during thermal treatments up to 1000 C with high energy X-rays. All investigations are performed with a focusing Laue diffractometer. The parameters of the diffraction curve are the relative full width at half maximum (rFHWM) and the enhancement of the integral intensity (EII). A readout software has been developed to extract these automatically from the detector image for the measured 220, -220 and 040 Bragg peaks. The sample thickness is set to 15 mm as this enhances the sensitivity of the method and the samples are processed after the strain-field diffraction (SFD) experiments to wafers for an ex situ characterization demanding wafers. Three experimental series with a total of 21 in situ SFD experiments with different thermal treatments have been performed. The slope of the initial temperature ramp is set to 1 K/min in the first and the third series to generate a high precipitate (Bulk Micro Defect, BMD) density. In the second series the slope is chosen as 10 K/min to generate a lower density in the same silicon material. It is shown with all experiments and with preliminary works that the built up of strain during the heat treatment is caused by BMDs during the high temperature period of the treatment. The detection limit of series 1 is found at 7 nm at a density of 10{sup 13}/cm{sup 3}, of series 2 at 40 nm at a density of 2 x 10{sup 8}/cm{sup 3}, and at 8 nm at a density of 4.8 x 10{sup 12}/cm{sup 3} for series 3. The local maximum of the EII at 450 C, which emerges coincident with a local minimum of the rFWHM in series 2 may be caused by thermal donors (TD). With the experiments is shown that SFD operates in the infrared-laser scattering tomography detection range, but also reaches in a region covered only by transmission electron microscopy (TEM) so far. In contrast to these methods SFD is not limited to low temperatures and in situ experiments can be done. Thus not only the ex situ verified BMD parameters but their temporal development can detected by SFD for the first time with a laboratory setup. An other difference to TEM is the number of BMDs detected. Measurements of the BMD parameters of a small number of BMDs can be done with TEM at a very high resolution to deduce the properties of the total BMD ensemble. The SFD signal is influenced directly by all BMDs in the analyzed sample volume being in the order of 10{sup 14}/cm{sup 3}. Correlations of the EII and BMD parameters are made for the first and the third series. A linear relation is found between the EII level and the BMD diameter if the BMD density is constant as in series 1. The influence of the BMD density on the EII signal is considerably in series 3. The final EII level is mainly depending on the density of the BMDs. The BMD diameters in the series may be assumed as constant in most of the samples, as the distribution of the diameters within one sample is wider than between the samples. A correlation of the BMD density measured with TEM with the maximum of the slope of the EII shows a strong linear relationship for first and third series. Values of the second series reduce the correlation coefficient, as the EII signal depends on the BMD diameter which is in a different order of magnitude in this series. (orig.)

  11. Ductal carcinoma in situ: a challenging disease

    Sevilay Altintas

    2011-12-01

    Full Text Available Ductal carcinoma in situ (DCIS represents a heterogenous group of lesions with variable malignant potential. Although it is clearly pre-invasive, not all lesions progress to an invasive malignant disease. The significant increase in the frequency of diagnosis is the result of both widespread use of screening mammography and better recognition among pathologists. Treatment is controversial, but for several decades total mastectomy has been considered as the appropriate treatment. The tendency to be less aggressive in terms of surgery has followed the pattern of events observed in the treatment of invasive breast carcinomas. More recently, it has become clear that breastconserving procedures could be applied and selected on the basis of diagnostics and risk factors. When all patients with DCIS are considered, the overall mortality is extremely low, only about 1–2%. On the other hand, breast-conserving surgery is only curative in 75–85%; 50% of the local recurrences have proven to be invasive with a mortality rate of 12–15%. There is no place for axillary node dissection, adjuvant hormonal treatment or chemotherapy in the treatment. Important factors in predicting local recurrence are age, family history, nuclear grade, comedo-type necrosis, tumor size and margin width. With the addition of radiation therapy to excisional surgery, there is a 50% reduction in the overall local recurrence rate. The Van Nuys Prognostic Index (VNPI, recently updated, is a tool that quantifies measurable prognostic factors that can be used in the decision-making process of treatment. Recent data from large cohort studies and randomized trials have emerged to guide treatment. DCIS is now understood to have diverse malignant potential and it is unlikely that there will be a single treatment for this wide range of lesions. Advances in molecular biology and gene expression profiling of human breast tumors have been providing important insights into the relationship between DCIS and invasive breast cancer.

  12. In-situ chemical oxidation of MTBE

    In-situ chemical oxidation (ISCO) can be a cost-effective method for the destruction of source areas of methyl tertiary butyl ether (MTBE). Several ISCO processes have been tested successfully under laboratory conditions and a few have proven successful when field tested for the destruction of MTBE. This paper reviews the state of the art with respect to MTBE oxidation for several common oxidants and Advanced Oxidation Processes (AOPs). Four frequently used oxidants are reviewed in this paper: hydrogen peroxide (H2O2), ozone (O3), permanganate (MnO4- ), and persulfate (S2O82- ). When choosing an oxidant for a specific remediation strategy, trade-offs exist between oxidant strength and stability in the subsurface. Aquifer and water quality parameters such as pH, alkalinity, and soil oxidant demand (SOD) may influence the initiation and effectiveness of the ISCO reaction and may significantly increase the amount of oxidant required to treat the target contaminant. Oxidation end products are an important consideration in the selection of an oxidant, as not all oxidants have proven successful in complete mineralization of MTBE. Tert-butyl formate (TBF) and tert-butyl alcohol (TBA) are the major intermediate products in the oxidative reactions of MTBE and may pose a greater health hazard than MTBE. Other factors, including regulatory restrictions, need to be considered when choosing an oxidant for a specific application. This paper will highlight the chemistry of the oxidant/MTBE reactions, successes or limitations observed under laboratory and field conditions, and practical design advice when employing the oxidant. (author)

  13. Retinal detachment after laser In Situ keratomileusis

    Saba Al-Rashaed

    2011-01-01

    Full Text Available Purpose : To report characteristics and outcome of rhegmatogenous retinal detachment (RRD after laser in situ keratomileusis (LASIK for myopia. Materials and Methods : A retrospective chart review of patients who presented with RRD after myopic LASIK over a 10-year period. Results : Fourteen eyes were identified with RRD. Of these, two of 6112 LASIK procedures were from our center. The mean age of patients with RRD was 35.43 years. The mean interval of RRD after LASIK was 37.71 months (range, 4 months to 10 years. The macula was involved in eight eyes and spared in six eyes. Retinal breaks included a macular hole in two eyes, and giant tear in two eyes. Multiple breaks (>2 breaks occurred in 6 cases. Pars plana vitrectomy (PPV was performed in 3 (21.4% eyes, a scleral buckle (SB was performed in 4 (28.5% eyes and 7 (50% eyes underwent combined PPV and SB. Mean follow-up was 15.18 months (range, 1 month to 7 years. The retina was successfully attached in all cases. The final visual acuity was 20/40 or better in 7 (50% eyes, 20/40 to 20/60 in 4 (28.5% eyes, and 20/200 or less in 3 (21.4% eyes. Poor visual outcome was secondary to proliferative vitreoretinopathy, epiretinal membrane, macular scar and amblyopia. Conclusion : The prevalence of RRD after LASIK was low at our institute. Anatomical and visual outcomes were acceptable in eyes that were managed promptly. Although there is no cause-effect relationship between LASIK and RRD, a dilated fundus examination is highly recommended before and after LASIK for myopia.

  14. Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

    Hatzinger, P.B.; Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

    2009-01-01

    Environmental context. Perchlorate (ClO4-) and nitrate (NO3-) are common co-contaminants in groundwater, with both natural and anthropogenic sources. Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater. Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations. However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions. In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4- (Cl and O) and NO3- (N and O) resulting from biodegradation in an aquifer. Abstract. An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br- as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (18O/37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ???0.8 (18O/15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (18O/37Cl, 18O/15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion. ?? CSIRO 2009.

  15. Conservative Management of an Advanced Abdominal Pregnancy at 22 Weeks

    Louis Marcellin

    2014-05-01

    Full Text Available Objective - We report an uneventful conservative approach of an advanced abdominal pregnancy discovered at 22 weeks of gestation. Study Design - This study is a case report. Results - Attempting to extend gestation of an advanced abdominal pregnancy is not a common strategy and is widely questioned. According to the couple's request, the management consisted in continuous hospitalization, regular ultrasound scan, and antenatal corticosteroids. While the woman remained asymptomatic, surgery was planned at 32 weeks, leading to the birth of a preterm child without any long-term complications. Placenta was left in situ with a prophylactic embolization, and its resorption was monitored. Conclusion - Depending on multidisciplinary cares and agreement of the parents, when late discovered, prolonging advanced abdominal pregnancy appears to be a reasonable option.

  16. Supramolecular hydrogels from in situ host-guest inclusion between chemically modified cellulose nanocrystals and cyclodextrin.

    Lin, Ning; Dufresne, Alain

    2013-03-11

    When grafted ?-cyclodextrin is used as targeting sites, Pluronic polymers have been introduced on the surface of cellulose nanocrystals by means of inclusion interaction between ?-cyclodextrin and hydrophobic segment of the polymer. Because of the steric stabilization effect, surface poly(ethylene glycol) chains facilitate the dispersion and compatibility of nanocrystals, which also enhance the loading levels of nanocrystals in the hydrogel system. Meanwhile, uncovered poly(ethylene glycol) segments render the participating inclusion of ?-cyclodextrin for the architecture of in situ hydrogels. Surface grafting and inclusion reactions were proved by solid (13)C NMR and FTIR. Grafting efficiency of ?-cyclodextrin and inclusion efficiency of Pluronic on the surface of nanocrystals were confirmed by UV spectroscopy and elemental analysis. A significant enhancement of the structural and thermal stability of in situ hydrogels with high loading levels of modified nanocrystals (>5.77 wt %) was observed by rheological analysis. Further study reveals the performance and behavior of hydrogels under a different pH environment. Finally, in situ hydrogels were used as drug carrier for in vitro release of doxorubicin and exhibit the behavior of prolonged drug release with special release kinetics. PMID:23347071

  17. Preparation and thermal properties of mesoporous silica/phenolic resin nanocomposites via in situ polymerization

    J. Lv

    2012-10-01

    Full Text Available In order to enhance the adhesion between inorganic particles and polymer matrix, in this paper, the mesoporous silica SBA-15 material was synthesized by the sol-gel method. The surface of SBA-15 was modified using γ-glycidyloxypropyltrimethoxysilane (GOTMS as a coupling agent, and then mesoporous silica/phenolic resin (SBA-15/PF nanocomposites were prepared via in situ polymerization. The structural parameters and physical properties of SBA-15, SBA-15-GOTMS (SBA-15 surface treated using GOTMS as coupling agents and E-SBA-15/PF (SBA-15/PF nanocomposites extracted using ethanol as solvent were characterized by X-ray diffraction (XRD, N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, transmission electron microscopy (TEM and thermogravimetric analysis (TGA. The thermal properties of the nanocomposites were studied by differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. The results demonstrated that the GOTMS were successfully grafted onto the surface of SBA-15, and chemical bonds between PF and SBA-15-GOTMS were formed after in situ polymerization. In addition, it is found that the in situ polymerization method has great effects on the textural parameters of SBA-15. The results also showed that the glass transition temperatures and thermal stability of the PF nanocomposites were obviously enhanced as compared with the pure PF at silica contents between 1–3 wt%, due to the uniform dispersion of the modified SBA-15 in the matrix.

  18. In situ bioremediation strategies for oiled shoreline environments

    Despite advances in preventative measures, recent events have demonstrated that accidental oil spills at sea will still occur. While physical (e.g. booms and skimmers) and chemical (e.g. chemical dispersants) methods have been developed to recover and/or disperse oil spilled at sea, they are not 100% effective and are frequently limited by operational constraints attributed to sea state and/or nature of the contamination. As a result, oil spills frequently impact shoreline environments. In situ bioremediation, the addition of substances or modification of habitat at contaminated sites to accelerate natural biodegradation processes, is now recognised as an alternative spill response technology of the remediation of these sites. Recommended for use following the physical removal of bulk oil, this treatment strategy has an operational advantage in that it breaks down and/or removes the residual contamination in place. Laboratory experiments and field trials have demonstrated the feasibility and success of bioremediation strategies such as nutrient enrichment to enhance bacterial degradation of oil on cobble, sand beach and salt marsh environments. With improved knowledge of the factors that limit natural oil degradation rates, the feasibility of other strategies such as phytoremediation, enhanced oil-mineral fines interaction and the addition of oxygen or alternative electron acceptors are now being evaluated. Laboratory and field test protocols are being refined for the selection of effective bioremediation agents and methods of application. It is recommended that future operational guidelines include real time product efficacy test and environmental effects monitoring programs. Termination of treatment should be implemented when: 1) it is no longer effective; 2) the oil has degraded to acceptable biologically benign concentrations; or 3) toxicity due to the treatment is increasing. (Author)

  19. In Situ Hydrocarbon Degradation by Indigenous Nearshore Bacterial Populations

    Potential episodic hydrocarbon inputs associated with oil mining and transportation together with chronic introduction of hydrocarbons via urban runoff into the relatively pristine coastal Florida waters poses a significant threat to Florida's fragile marine environment. It is therefore important to understand the extent to which indigenous bacterial populations are able to degrade hydrocarbon compounds and also determine factors that could potentially control and promote the rate at which these compounds are broken down in situ. Previous controlled laboratory experiments carried out by our research group demonstrated that separately both photo-oxidation and cometabolism stimulate bacterial hydrocarbon degradation by natural bacterial assemblages collected from a chronically petroleum contaminated site in Bayboro Bay, Florida. Additionally, we also demonstrated that stable carbon and radiocarbon abundances of respired CO2 could be used to trace in situ hydrocarbon degradation by indigenous bacterial populations at this same site. This current proposal had two main objectives: (a) to evaluate the cumulative impact of cometabolism and photo-oxidation on hydrocarbon degradation by natural bacterial assemblages collected the same site in Bayboro Bay, Florida and (b) to determine if in situ hydrocarbon degradation by indigenous bacterial populations this site could be traced using natural radiocarbon and stable carbon abundances of assimilated bacterial carbon. Funds were used for 2 years of full support for one ESI Ph.D. student, April Croxton. To address our first objective a series of closed system bacterial incubations were carried out using photo-oxidized petroleum and pinfish (i.e. cometabolite). Bacterial production of CO2 was used as the indicator of hydrocarbon degradation and (delta)13C analysis of the resultant CO2 was used to evaluate the source of the respired CO2 (i.e. petroleum hydrocarbons or the pinfish cometabolite). Results from these time series experiments demonstrated that short-term exposure of petroleum to UV light enhanced hydrocarbon degradation by 48% over that observed for non-photo-oxidized petroleum. Despite the greater bio-availability of the photo-oxidized over the non-photo-oxidized petroleum, an initial lag in CO2 production was observed indicating potential phototoxicity of the photo- by-products. (delta)13C analysis and mass balance calculations reveal that co-metabolism with pinfish resulted in increased hydrocarbon degradation for both photo-oxidized and non-photo-oxidized petroleum each by over 100%. These results demonstrate the cumulative effect of photo-oxidation and co-metabolism on petroleum hydrocarbon degradation by natural bacterial populations indigenous to systems chronically impacted by hydrocarbon input. To address the second objective of this proposal bacterial concentrates were collected from Bayboro Harbor in April 2001 for nucleic acid extraction and subsequent natural radiocarbon abundance analyses. Unfortunately, however, all of these samples were lost due to a faulty compressor in our -70 freezer. The freezer was subsequently repaired and samples were again collected from Bayboro Harbor in June 2002 and again December 2002. Several attempts were made to extract the nucleic acid samples--however, the student was not able to successfully extract and an adequate amount of uncontaminated nucleic acid samples for subsequent natural radiocarbon abundance measurements of the bacterial carbon by accelerator mass spectrometry (i.e. require at least 50 (micro)g carbon for AMS measurement). Consequently, we were not able to address the second objective of this proposed work

  20. Metalloprotein Adsorption on Au(111) and Polycrystalline Platinum Investigated by In Situ Scanning Tunnelling Microscopy with Molecular and Sub-Molecular Resolution

    Friis, Esben P.; Andersen, Jens Enevold Thaulov; Madsen, Lars Lithen; Møller, Per; Nichols, R.J.; Ulstrup, Jens

    at the molecular level. In addition to broadly recognized problems of in situ STM/AFM imaging, sample prep- aration, mobility, and adsorbate stability are, however, particular problems. We illustrate here the perspec- tives by recent in situ STM imaging of covalently bound horse heart cytochrome c on...... linking, facile ET routes through the protein, and tunnel enhancement by the low-lying redox level of the copper atom. The particular electronic-vibrational three-level con®guration in in situ STM of metalloproteins, ®nally, o€ers a new way of distinction between superexchange, coherent, and sequential ET...

  1. Doxorubicin-loaded zein in situ gel for interstitial chemotherapy of colorectal cancer

    Ning Shen

    2012-12-01

    Full Text Available The aim of this research was to evaluate doxorubicin (DOX-loaded zein in situ gels, a new drug delivery system in which a liquid state drug can be transformed into semi-solid after intratumoral injection. In vitro release of DOX-loaded zein was investigated and the pharmacokinetics, biodistribution and therapeutic efficacy of these DOX-loaded zein formulations were investigated using BALB/c nude tumor-bearing mice. In vitro release of DOX from the gels extended up to 7 days. Efficient accumulation of DOX in the tumor with lower drug concentration in blood and normal organs was obtained resulting in effective inhibition of tumor growth and fewer off-target side effects. In conclusion, a DOX-loaded in situ gel was developed with sustained release, enhanced anti-cancer efficacy for colorectal cancer in vivo, and especially with reduced off-target side effects.

  2. The growth and in situ characterization of chemical vapor deposited SiO2

    Iyer, R.; Chang, R. R.; Lile, D. L.

    1987-01-01

    This paper reports the results of studies of the kinetics of remote (indirect) plasma enhanced low pressure CVD growth of SiO2 on Si and InP and of the in situ characterization of the electrical surface properties of InP during CVD processing. In the latter case photoluminescence was employed as a convenient and sensitive noninvasive method for characterizing surface trap densities. It was determined that, provided certain precautions are taken, the growth of SiO2 occurs in a reproducible and systematic fashion that can be expressed in an analytic form useful for growth rate prediction. Moreover, the in situ photoluminescence studies have yielded information on sample degradation resulting from heating and chemical exposure during the CVD growth.

  3. Combining Space-Based and In-Situ Measurements to Track Flooding in Thailand

    Chien, Steve; Doubleday, Joshua; Mclaren, David; Tran, Daniel; Tanpipat, Veerachai; Chitradon, Royal; Boonya-aaroonnet, Surajate; Thanapakpawin, Porranee; Khunboa, Chatchai; Leelapatra, Watis; Plermkamon, Vichian; Raghavendra, Cauligi; Mandl, Daniel

    2011-01-01

    We describe efforts to integrate in-situ sensing, space-borne sensing, hydrological modeling, active control of sensing, and automatic data product generation to enhance monitoring and management of flooding. In our approach, broad coverage sensors and missions such as MODIS, TRMM, and weather satellite information and in-situ weather and river gauging information are all inputs to track flooding via river basin and sub-basin hydrological models. While these inputs can provide significant information as to the major flooding, targetable space measurements can provide better spatial resolution measurements of flooding extent. In order to leverage such assets we automatically task observations in response to automated analysis indications of major flooding. These new measurements are automatically processed and assimilated with the other flooding data. We describe our ongoing efforts to deploy this system to track major flooding events in Thailand.

  4. An in situ operando MEMS platform for characterization of Li-ion battery electrodes

    Jung, H.; Gerasopoulos, K.; Zhang, X.; Ghodssi, R.

    2015-12-01

    This paper presents an in situ operando approach that allows characterization of lithium-ion battery electrodes. A MEMS sensor is designed and integrated with a commercially available Raman spectroscope to enable monitoring the stress and structural changes in the electrodes. An interferometric method with an enhanced image processing algorithm is applied for analyzing the crystal phase-dependent stress changes - contributing to higher sensitivity compared to a previously reported technique - while the structural changes are monitored using Raman spectroscopy. New capabilities of our platform are highlighted, allowing visual observation of crystal phase-dependent structural changes in the electrode. Simultaneous characterization of the stress and structural changes are achieved concurrently in situ operando. The results show excellent agreement with previous literature reports on both phenomena.

  5. Demonstration, testing, and evaluation of in situ heating of soil. Volume 1, Final report

    This document is a final reports in two volumes. Volume I contains the technical report and Volume II contains appendices with background information and data. In this project approximately 300 cubic yards of clayey soil containing a low concentration plume of volatile organic chemicals was heated in situ by the application of electrical energy. It was shown that as a result of heating the effective permeability of soil to air flow was increased such that in situ soil vapor extraction could be performed. The initial permeability of soil was so low that the soil gas flow rate was immeasurably small even at high vacuum levels. It was demonstrated that the mass flow rate of the volatile organic chemicals was enhanced in the recovered soil gas as a result of heating

  6. Orientation relationship in WC-Co composite nanoparticles synthesized by in situ reactions

    Wang, Xilong; Song, Xiaoyan; Liu, Xuemei; Liu, Xingwei; Wang, Haibin; Zhou, Cheng

    2015-04-01

    Using the nanoscale violet tungsten oxide as the tungsten source, the WC-Co composite powder was synthesized by the in situ reactions. The particle size of the WC-Co composite powder has a narrow distribution with the mean particle size below 100 nm, and the single composite particle has a nanocrystalline structure with a mean grain size smaller than 10 nm. The detailed characterizations of the nanoparticle microstructure reveal that the orientation relationship and coherence at the interfaces can form during the in situ reactions and further inherit in the consolidated cemented carbide bulk material. The favorable crystallographic characteristics of the WC-Co composite nanoparticles play a significant role in the enhancement of the mechanical properties of the prepared cemented carbide bulk material.

  7. In situ luminescence qualification of radiation damage in aluminas: F-aggregation and Al colloids

    Malo, M., E-mail: marta.malo@ciemat.es; Moroo, A.; Hodgson, E.R.

    2014-10-15

    Highlights: Correlation between IBIL and surface electrical degradation. Potential to remotely monitor degradation of insulating materials. Possibility for in situ recovery of the insulating properties by thermal annealing. -- Abstract: Recent work for in situ sequential measurement of ion beam induced luminescence and surface electrical conductivity has identified a correlation between surface electrical degradation and the luminescence for aluminas and sapphire during 45 keV He ion bombardment. Detailed measurements for the initial stages of degradation where rapid changes in the luminescence emission bands occur, have now identified processes related to oxygen vacancy (F centre) aggregation and aluminium colloid production as precursors to measurable surface electrical degradation in the irradiated region. This understanding enhances the possibility of using ion beam induced luminescence as a potential monitoring tool for material evolution and insulator surface degradation during irradiation, not only in ITER and future fusion devices, but also in present experimental reactor materials test programmes.

  8. NOVEL IN-SITU METAL AND MINERAL EXTRACTION TECHNOLOGY

    Glenn O' Gorman; Hans von Michaelis; Gregory J. Olson

    2004-09-22

    This white paper summarizes the state of art of in-situ leaching of metals and minerals, and describes a new technology concept employing improved fragmentation of ores underground in order to prepare the ore for more efficient in-situ leaching, combined with technology to continuously improve solution flow patterns through the ore during the leaching process. The process parameters and economic benefits of combining the new concept with chemical and biological leaching are described. A summary is provided of the next steps required to demonstrate the technology with the goal of enabling more widespread use of in-situ leaching.

  9. Proximal deletion of chromosome 21 confirmed by in situ hybridization and molecular studies

    Courtens, W.; Peterson, M.B.; Noeel, J.C.; Flament-Durand, J.; Van Regemorter, N.; Delneste, D.; Cochaux, P.; Verschraegen-Spae, M.R.; Van Roy, N.; Speleman, F. [Brugmann Univ. Hospital, Brussels (Belgium)] [and others

    1994-07-01

    Foetal blood sampling was performed at 35 weeks of gestation due to abnormal foetal ultrasound findings. There was apparent monosomy 21 (45,XX,-21) in all mitoses analyzed. The infant died at 37 weeks during delivery. Examination disclosed facial anomalies, clubfeet, hypoplasia of the left urogenital tract, agenesis of corpus callosum, ventricular dilatation, and heterotopias. Reevaluation of the karyotype showed an unbalanced translocation (1;21) (q44;q22.11) which resulted from a maternal balanced translocation. These findings were confirmed by fluorescence in situ hybridization and molecular studies with chromosome 21 specific markers. The latter showed a proximal deletion of the maternally derived chromosome 21 including all loci from centrometer down to the D21S210 locus. This case illustrates the need for complementary cytogenetic and molecular investigations in cases of apparent monosomy 21. 41 refs., 4 figs., 2 tabs.

  10. In Situ Probe Science at Saturn

    Atkinson, D.H.; Lunine, J.I.; Simon-Miller, A. A.; Atreya, S. K.; Brinckerhoff, W.; Colaprete, A.; Coustenis, A.; Fletcher, L. N.; Guillot, T.; Lebreton, J.-P.; Mahaffy, P.; Mousis, O.; Orton, G. S.; Reh, K.; Spilker, L. J.; Spilker, T. R.; Webster, C.

    2014-01-01

    A fundamental goal of solar system exploration is to understand the origin of the solar sys-tem, the initial stages, conditions, and processes by which the solar system formed, how the formation pro-cess was initiated, and the nature of the interstellar seed material from which the solar system was born. Key to understanding solar system formation and subsequent dynamical and chemical evolution is the origin and evolution of the giant planets and their atmospheres. Several theories have been put forward to explain the process of solar system formation, and the origin and evolution of the giant planets and their atmospheres. Each theory offers quantifiable predictions of the abundances of noble gases He, Ne, Ar, Kr, and Xe, and abundances of key isotopic ratios 4He3He, DH, 15N14N, 18O16O, and 13C12C. Detection of certain dis-equilibrium species, diagnostic of deeper internal pro-cesses and dynamics of the atmosphere, would also help discriminate between competing theories. Measurements of the critical abundance profiles of these key constituents into the deeper well-mixed at-mosphere must be complemented by measurements of the profiles of atmospheric structure and dynamics at high vertical resolution and also require in situ explora-tion. The atmospheres of the giant planets can also serve as laboratories to better understand the atmospheric chem-istries, dynamics, processes, and climates on all planets including Earth, and offer a context and provide a ground truth for exoplanets and exoplanetary systems. Additionally, Giant planets have long been thought to play a critical role in the development of potentially habitable planetary systems. In the context of giant planet science provided by the Galileo, Juno, and Cassini missions to Jupiter and Sat-urn, a small, relatively shallow Saturn probe capable of measuring abundances and isotopic ratios of key at-mospheric constituents, and atmospheric structure in-cluding pressures, temperatures, dynamics, and cloud locations and properties not accessible by remote sens-ing can serve to test competing theories of solar system and giant planet origin, chemical, and dynamical evolution.

  11. Magnetospheric Interaction at Jupiter's Galilean Moons Io, Europa, Ganymede, Callisto: Galileo in-Situ Measurements Compared with Simulation Results

    Krupp, N.; Jia, X.; Roussos, E.; Fraenz, M.

    2014-12-01

    Between 1995 and 2003 the Galileo spacecraft orbited Jupiter and flew-by multiple times at the Galilean satellites Io (7), Europa (12), Ganymede (5), and Callisto (8). The wealth of new unprecedented data from Galileo in-situ measurements in comparison to hybrid- and MHD simulation results enhanced our view of the understanding of the interaction between the moons (or in the case of Ganymede's own magnetosphere) and the surrounding highly dynamic Jovian magnetosphere. In this paper the in-situ particles and fields measurements are reviewed in the context of the future ESA-mission JUICE to arrive in the Jovian system in 2030.

  12. Adult Learners' Week in Australia.

    Cross, John

    2002-01-01

    Promotional materials and activities for Australia's Adult Learners Week, which are shaped by a variety of stakeholders , include media strategies and a website. Activities are evaluated using a market research company and website and telephone hotline statistics. (SK)

  13. Development of an rRNA-targeted oligonucleotide probe specific for the genus Acinetobacter and its application for in situ monitoring in activated sludge.

    M. Wagner; Erhart, R; Manz, W; Amann, R; Lemmer, H; Wedi, D; Schleifer, K H

    1994-01-01

    Enhanced biological phosphate removal in an anaerobic-aerobic activated sludge system has generally been ascribed to members of the genus Acinetobacter. A genus-specific 16S rRNA-targeted oligonucleotide probe was developed to investigate the role of Acinetobacter spp. in situ. Nonisotopic dot blot hybridization to 66 reference strains, including the seven described Acinetobacter spp., demonstrated the expected probe specificity. Fluorescent derivatives were used for in situ monitoring of Aci...

  14. Novel Instrumentation for In Situ Combustion Measurements Project

    National Aeronautics and Space Administration The objective of the Phase I is to develop, demonstrate and test a novel instrument based on laser absorption diagnostics for fast, in situ measurements of...

  15. Advanced hydraulic fracturing methods to create in situ reactive barriers

    This article describes the use of hydraulic fracturing to increase permeability in geologic formations where in-situ remedial action of contaminant plumes will be performed. Several in-situ treatment strategies are discussed including the use of hydraulic fracturing to create in situ redox zones for treatment of organics and inorganics. Hydraulic fracturing methods offer a mechanism for the in-situ treatment of gently dipping layers of reactive compounds. Specialized methods using real-time monitoring and a high-energy jet during fracturing allow the form of the fracture to be influenced, such as creation of assymmetric fractures beneath potential sources (i.e. tanks, pits, buildings) that should not be penetrated by boring. Some examples of field applications of this technique such as creating fractures filled with zero-valent iron to reductively dechlorinate halogenated hydrocarbons, and the use of granular activated carbon to adsorb compounds are discussed

  16. In situ bioremediation of chlorinated solvent with natural gas

    A bioremediation system for the removal of chlorinated solvents from ground water and sediments is described. The system involves the the in-situ injection of natural gas (as a microbial nutrient) through an innovative configuration of horizontal wells

  17. In situ sampling cart development engineering task plan

    This Engineering Task Plan (ETP) supports the development for facility use of the next generation in situ sampling system for characterization of tank vapors. In situ sampling refers to placing sample collection devices (primarily sorbent tubes) directly into the tank headspace, then drawing tank gases through the collection devices to obtain samples. The current in situ sampling system is functional but was not designed to provide the accurate flow measurement required by today's data quality objectives (DQOs) for vapor characterization. The new system will incorporate modern instrumentation to achieve much tighter control. The next generation system will be referred to in this ETP as the New In Situ System (NISS) or New System. The report describes the current sampling system and the modifications that are required for more accuracy

  18. Process for in-situ leaching of uranium

    An in-situ leaching process employs a carbonate or bicarbonate leaching agent and an oxidizing agent. The lixiviant is heated to a temperature of at least 1100F prior to injection into the uranium deposit

  19. In-situ polymerization PLOT columns I: divinylbenzene

    Shen, T. C.

    1992-01-01

    A novel method for preparation of porous-layer open-tubular (PLOT) columns is described. The method involves a simple and reproducible, straight-forward in-situ polymerization of monomer directly on the metal tube.

  20. In Situ Oxygen Production from Lunar and Martian Regolith Project

    National Aeronautics and Space Administration — In situ oxygen production is of immense importance to NASA in the support of the NASA initiative to sustain man's permanent presence in space. The oxygen produced...

  1. In-situ Airborne Sampler for Advanced Guided Dropsonde Project

    National Aeronautics and Space Administration — The proposed innovation is a low-cost, retrievable and reusable, autonomously guided dropsonde capable of in-situ atmospheric measurements. The proposed effort will...

  2. Novel Instrumentation for In Situ Combustion Measurements Project

    National Aeronautics and Space Administration — The objective of the Phase I is to develop, demonstrate and test a novel instrument based on laser absorption diagnostics for fast, in situ measurements of...

  3. An Efficient Heat Exchanger for In Situ Resource Utilization Project

    National Aeronautics and Space Administration — In situ resource utilization (ISRU) is essential for several of NASA's future flagship missions. Currently envisioned ISRU plants include production of oxygen from...

  4. The in-situ decontamination of sand and gravel aquifers by chemically enhanced solubilization of multiple-compound DNAPLs with surfactant solutions. Phase 1: Laboratory and pilot field-scale testing. Phase 2: Solubilization test and partitioning interwell tracer tests. Final report

    Laboratory, numerical simulation, and field studies have been conducted to assess the potential use of micellar-surfactant solutions to solubilize chlorinated solvents contaminating sand and gravel aquifers. Ninety-nine surfactants were screened for their ability to solubilize trichloroethene (TCE), perchloroethylene (PCE), and carbon tetrachloride (CTET). The field test was conducted in the alluvial aquifer which is located 20 to 30 meters beneath a vapor degreasing operation at Paducah Gaseous Diffusion Plant. This aquifer has become contaminated with TCE due to leakage of perhaps 40,000 liters of TCE, which has generated a plume of dissolved TCE extending throughout an area of approximately 3 km2 in the aquifer. Most of the TCE is believed to be present in the overlying lacustrine deposits and in the aquifer itself as a dense, non-aqueous phase liquid, or DNAPL. The objective of the field test was to assess the efficacy of the surfactant for in situ TCE solubilization. Although the test demonstrated that sorbitan monooleate was unsuitable as a solubilizer in this aquifer, the single-well test was demonstrated to be a viable method for the in situ testing of surfactants or cosolvents prior to proceeding to full-scale remediation

  5. The in-situ decontamination of sand and gravel aquifers by chemically enhanced solubilization of multiple-compound DNAPLs with surfactant solutions: Phase 1 -- Laboratory and pilot field-scale testing and Phase 2 -- Solubilization test and partitioning and interwell tracer tests. Final report

    NONE

    1997-10-24

    Laboratory, numerical simulation, and field studies have been conducted to assess the potential use of micellar-surfactant solutions to solubilize chlorinated solvents contaminating sand and gravel aquifers. Ninety-nine surfactants were screened for their ability to solubilize trichloroethene (TCE), perchloroethylene (PCE), and carbon tetrachloride (CTET). The field test was conducted in the alluvial aquifer which is located 20 to 30 meters beneath a vapor degreasing operation at Paducah Gaseous Diffusion Plant. This aquifer has become contaminated with TCE due to leakage of perhaps 40,000 liters of TCE, which has generated a plume of dissolved TCE extending throughout an area of approximately 3 km{sup 2} in the aquifer. Most of the TCE is believed to be present in the overlying lacustrine deposits and in the aquifer itself as a dense, non-aqueous phase liquid, or DNAPL. The objective of the field test was to assess the efficacy of the surfactant for in situ TCE solubilization. Although the test demonstrated that sorbitan monooleate was unsuitable as a solubilizer in this aquifer, the single-well test was demonstrated to be a viable method for the in situ testing of surfactants or cosolvents prior to proceeding to full-scale remediation.

  6. Remediation of SRS Basins by In Situ Stabilization/Solidification

    In the late summer of 1998, the Savannah River Site began remediation of two radiologically contaminated basins using in situ stabilization. These two high-risk, unlined basins contain radiological contaminants, which potentially pose significant risks to human health and the environment. The selected remedy involves in situ stabilization/solidification of the contaminated wastes (basin and pipeline soils, pipelines, vegetation, and other debris) followed by installation of a low permeability soil cover

  7. Characterization of VPO ammoxidation catalysts by in situ methods

    Martin, A.; Luecke, B.; Brueckner, A.; Steinike, U. [Institut fuer Angewandte Chemie Berlin-Adlershof e.V., Berlin (Germany); Brzezinka, K.W. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Meisel, M. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Chemie

    1998-12-31

    In-situ methods are well known as powerful tools in studying catalyst formation processes, their solid state properties under working conditions and the interaction with the feed, intermediates and products to reveal reaction mechanisms. This paper gives a short overview on results of intense studies using in-situ techniques to reveal VPO catalyst generation processes, interaction of educts, intermediates and products with VPO catalyst surfaces and mechanistic insights. Catalytic data of the ammoxidation of toluene on different VPOs complete these findings. The precursor-catalyst transformation processes were preferently investigated by in-situ XRD, in-situ Raman and in-situ ESR spectroscopy. The interaction of aromatic molecules and intermediates, resp., and VPO solid surfaces was followed by in-situ ESR and in-situ FTIR spectroscopy. Mechanistic information was mainly obtained using in-situ FTIR spectroscopy and the temporal-analysis-of-products (TAP) technique. Catalytic studies were carried out in a fixed-bed microreactor on pure (NH{sub 4}){sub 2}(VO){sub 3}(P{sub 2}O{sub 7}){sub 2}, generated [(NH{sub 4}){sub 2}(VO{sub 3})(P{sub 2}O{sub 7}){sub 2}+V{sub x}O{sub y}] catalysts, having different V{sub x}O{sub y} proportions by use of VOHPO{sub 4} x 1/2H{sub 2}O (V/P=1) and recently studied (VO){sub 3}(PO{sub 4}){sub 2} x 7 H{sub 2}O (V/P=1.5) precursors; the well-known (VO){sub 2}P{sub 2}O{sub 7} was used for comparison. (orig.)

  8. BAW and SAW sensors for in-situ analysis

    Bar-Cohen, Y.; Bao, X. Q.; Chang, Z.; Sherrit, S.

    2003-01-01

    In-situ analysis is a major goal in current and future NASA exploration missions. In general in-situ analysis experiments are designed to investigate chmical, biological or geological markers or properties to determine the complex history of the body being studied. In order to expand the number of applicable sensor schemes an investigation into piezoelectric bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators has been initiated.

  9. In Situ Resource Utilization (ISRU II) Technical Interchange Meeting

    Kaplan, David (Compiler); Saunders, Stephen R. (Compiler)

    1997-01-01

    This volume contains extended abstracts that have been accepted for presentation at the In Situ Resource Utilization (ISRU II) Technical Interchange Meeting, November 18-19, 1997, at the Lunar and Planetary Institute, Houston, Texas. Included are topics which include: Extraterrestrial resources, in situ propellant production, sampling of planetary surfaces, oxygen production, water vapor extraction from the Martian atmosphere, gas generation, cryogenic refrigeration, and propellant transport and storage.

  10. Matrix diffusion model. In situ tests using natural analogues

    Rasilainen, K. [VTT Energy, Espoo (Finland)

    1997-11-01

    Matrix diffusion is an important retarding and dispersing mechanism for substances carried by groundwater in fractured bedrock. Natural analogues provide, unlike laboratory or field experiments, a possibility to test the model of matrix diffusion in situ over long periods of time. This thesis documents quantitative model tests against in situ observations, done to support modelling of matrix diffusion in performance assessments of nuclear waste repositories. 98 refs. The thesis includes also eight previous publications by author.

  11. In situ Management and Domestication of Plants in Mesoamerica

    Casas, Alejandro; Otero-Arnaiz, Adriana; Pérez-Negrón, Edgar; Valiente-Banuet, Alfonso

    2007-01-01

    Background and Aims Ethnobotanical studies in Mexico have documented that Mesoamerican peoples practise systems of in situ management of wild and weedy vegetation directed to control availability of useful plants. In situ management includes let standing, encouraging growing and protection of individual plants of useful species during clearance of vegetation, which in some cases may involve artificial selection. The aim of this study was to review, complement and re-analyse information from t...

  12. Polypropylene/graphite nanocomposites by in situ polymerization

    This work presents the synthesis of nanocomposites of polypropylene/graphite by in situ polymerization using metallocene catalyst and graphene nanosheets. Initially was analyzed which of the metallocene catalysts rac-Et(Ind)2ZrCl2 or rac-Me2Si(Ind)2ZrCl2 produces polypropylene with mechanical properties more relevant. Then it were performed the in situ polymerization reactions to obtain the nanocomposites. The polymeric materials were characterized by XRD, DSC, GPC and DMTA. (author)

  13. Numerical simulation of vertical infiltration for leaching fluid in situ

    Based on the analysis of movement law of leaching fluid in breaking and leaching experiment in situ, the movement of leaching fluid can be divided into two main stages in the leaching process in situ: Vertical Infiltration in unsaturation zone and horizontal runoff in saturation zone. The corresponding mathematics models are sep up, and the process of vertical infiltration of leaching fluid is numerically simulated

  14. Superconducting proximity effect for in situ and model layered systems

    The primary drawback for in situ composites is that the ac losses are higher than for mechanically produced multifilamentary wire. To develop an understanding of the proximity effect so that analytical expressions will be available for design, a model system is developed based on PbCd. Items discussed include boundary conditions at SN interface, phonon spectral function, supercurrents through normal barriers, flux entry fields, and implications for in situ composites

  15. Matrix diffusion model. In situ tests using natural analogues

    Matrix diffusion is an important retarding and dispersing mechanism for substances carried by groundwater in fractured bedrock. Natural analogues provide, unlike laboratory or field experiments, a possibility to test the model of matrix diffusion in situ over long periods of time. This thesis documents quantitative model tests against in situ observations, done to support modelling of matrix diffusion in performance assessments of nuclear waste repositories

  16. High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in situ production

    Fan, X.; Chappellaz, J.; Rhodes, R. H.; Stowasser, C.; Blunier, T.; McConnell, J. R.; Brook, E. J.; Preunkert, S.; Legrand, M.; Debois, T.; Romanini, D.

    2014-05-01

    We present high-resolution measurements of carbon monoxide (CO) concentrations from a shallow ice core of the North Greenland Eemian Ice Drilling project (NEEM-2011-S1). An optical-feedback cavity-enhanced absorption spectrometer (OF-CEAS) coupled to a continuous melter system performed continuous, online analysis during a four-week measurement campaign. This analytical setup generated stable measurements of CO concentrations with an external precision of 7.8 ppbv (1?), based on repeated analyses of equivalent ice core sections. However, this first application of this measurement technique suffered from a poorly constrained procedural blank of 48 25 ppbv and poor accuracy because an absolute calibration was not possible. The NEEM-2011-S1 CO record spans 1800 yr and the long-term trends within the most recent section of this record (i.e., post 1700 AD) resemble the existing discrete CO measurements from the Eurocore ice core. However, the CO concentration is highly variable (75-1327 ppbv range) throughout the ice core with high frequency (annual scale), high amplitude spikes characterizing the record. These CO signals are too abrupt and rapid to reflect atmospheric variability and their prevalence largely prevents interpretation of the record in terms of atmospheric CO variation. The abrupt CO spikes are likely the result of in situ production occurring within the ice itself, although the unlikely possibility of CO production driven by non-photolytic, fast kinetic processes within the continuous melter system cannot be excluded. We observe that 68% of the CO spikes are observed in ice layers enriched with pyrogenic aerosols. Such aerosols, originating from boreal biomass burning emissions, contain organic compounds, which may be oxidized or photodissociated to produce CO within the ice. However, the NEEM-2011-S1 record displays an increase of ~0.05 ppbv yr-1 in baseline CO level prior to 1700 AD (129 m depth) and the concentration remains elevated, even for ice layers depleted in dissolved organic carbon (DOC). Thus, the processes driving the likely in situ production of CO within the NEEM ice may involve multiple, complex chemical pathways not all related to past fire history and require further investigation.

  17. In situ measurement of conductivity during nanocomposite film deposition

    Blattmann, Christoph O.; Pratsinis, Sotiris E.

    2016-05-01

    Flexible and electrically conductive nanocomposite films are essential for small, portable and even implantable electronic devices. Typically, such film synthesis and conductivity measurement are carried out sequentially. As a result, optimization of filler loading and size/morphology characteristics with respect to film conductivity is rather tedious and costly. Here, freshly-made Ag nanoparticles (nanosilver) are made by scalable flame aerosol technology and directly deposited onto polymeric (polystyrene and poly(methyl methacrylate)) films during which the resistance of the resulting nanocomposite is measured in situ. The formation and gas-phase growth of such flame-made nanosilver, just before incorporation onto the polymer film, is measured by thermophoretic sampling and microscopy. Monitoring the nanocomposite resistance in situ reveals the onset of conductive network formation by the deposited nanosilver growth and sinternecking. The in situ measurement is much faster and more accurate than conventional ex situ four-point resistance measurements since an electrically percolating network is detected upon its formation by the in situ technique. Nevertheless, general resistance trends with respect to filler loading and host polymer composition are consistent for both in situ and ex situ measurements. The time lag for the onset of a conductive network (i.e., percolation) depends linearly on the glass transition temperature (Tg) of the host polymer. This is attributed to the increased nanoparticle-polymer interaction with decreasing Tg. Proper selection of the host polymer in combination with in situ resistance monitoring therefore enable the optimal preparation of conductive nanocomposite films.

  18. In-situ diffusion in granite: results from scoping experiments

    This report describes the scoping experiments carried out, both in the laboratory and in-situ at a depth of ∼450 m in the Underground Research Laboratory, for the study to determine the diffusion parameters of intact granite/granodiorite under natural high-stress conditions. The study includes four in-situ diffusion experiments (one each in four separate boreholes with experiment times from six months to two years), and supporting laboratory experiments. Tentative conclusions from the first 203-day in-situ experiment in hole DIF4 indicate that the in-situ tortuosity value of granodiorite under high stress conditions may be significantly higher than those obtained from measurements on the same rock under ambient conditions in the laboratory. Because problems were encountered during drilling of the in-situ sample core, potentially adversely affecting the analytical data, further work needs to be carried out to substantiate these tentative conclusions. Tortuosity values obtained in the laboratory for de-stressed rock from the in-situ experiment zones range between 2.4 and 4.6, falling well within the range of tortuosity values reported by Davison et al. (1994) that were used for the assessment modelling of the reference disposal system (Goodwin et al. 1994). The granodiorite samples have lower tortuosity values (between 2.4 and 3.9) compared with that of the single granite sample (4.6). (author)

  19. In situ leaching of uranium: Technical, environmental and economic aspects

    Within the framework of its activities in nuclear raw materials the International Atomic Energy Agency has convened a series of meetings to discuss various aspects of uranium ore processing technology, recovery of uranium from non-conventional resources and development of projects for the production of uranium concentrates including economic aspects. As part of this continuing effort to discuss and document important aspects of uranium production the IAEA convened a Technical Committee Meeting on Technical, Economic and Environmental Aspects of In-Situ Leaching. Although the use of this technique is limited by geological and economic constraints, it has a significant potential to produce uranium at competitive prices. This is especially important in the current uranium market which is mainly characterised by large inventories, excess production capability and low prices. This situation is not expected to last indefinitely but it is unlikely to change drastically in the next ten years or so. This Technical Committee Meeting was held in Vienna from 3 to 6 November 1987 with the attendance of 24 participants from 12 countries. Eight papers were presented. Technical sessions covered in-situ mining research, environmental and licensing aspects and restoration of leached orebodies; the technological status of in-situ leaching, the current status and future prospects of in-situ leaching of uranium in Member States, general aspects of planning and implementation of in-situ projects and the economics of in-situ leaching. Refs, figs and tabs

  20. Probing initial-stages of ALD growth with dynamic in situ spectroscopic ellipsometry

    Graphical abstract: - Highlights: • Dynamic in situ spectroscopic ellipsometry to study ALD growth initiation. • Sub-monolayer ALD growth is modeled as diffusive film growth mode. • Bruggeman's EMA model used to analyze d-iSE data. • Plasma enhanced ALD of ZrN is presented as example. • Surface coverage of ZrN film is calculated after every ALD cycle. - Abstract: The initial stages of ALD surface reactions are probed using dynamic in situ spectroscopic ellipsometry (d-iSE) technique during plasma-enhanced ALD of zirconium nitride (ZrN) thin films in spectral range of 0.73–6.4 eV. The measured change in the ellipsometry parameter Δ, with every precursor (TDMAZr) and reactant (forming gas plasma) exposure is interpreted as the combined effect of film growth and change in surface chemistry during ALD. We present application of Bruggeman's effective-medium approximation (B-EMA) in the analysis of d-iSE data to determine fractional surface coverage (θ) of ALD grown film at the end of every deposition cycle. During the deposition of first few ZrN monolayers, d-iSE datasets are analyzed on the basis of surface diffusion enhanced ALD growth, where the surface adsorbed precursor molecules can diffuse over substrate surface to occupy energetically favorable surface sites. The determined surface coverage of ZrN films highlights the effects of substrate enhanced ALD growth

  1. Effect of in situ acids removal on mixed glucose and xylose fermentation by Clostridium tyrobutyricum.

    Baroi, George Nabin; Skiadas, Ioannis V; Westermann, Peter; Gavala, Hariklia N

    2015-12-01

    In the present study, the effect of potassium ions and increasing concentrations of glucose and xylose on the growth of a strain of Clostridium tyrobutyricum, adapted to wheat straw hydrolysate, was investigated. Application of continuous fermentation of a mixture of glucose and xylose and in situ acid removal by reverse electro enhanced dialysis (REED) was investigated as a method to alleviate potassium and end-product inhibition and consequently enhance the sugar consumption rates and butyric acid productivity. It was found that glucose and xylose were not inhibitory up to a concentration of 50 and 37g L(-1) respectively, and that they were consumed at comparable rates when fermented alone. However, continuous fermentation of a mixture of glucose and xylose resulted in a significantly decreased xylose consumption rate compared to that of glucose alone, supporting the conclusion that C. tyrobutyricum has a lower affinity for xylose than for glucose. Potassium ions negatively affected the effective maximum growth rate of C. tyrobutyricum at concentrations higher than 5g L(-1) exhibiting a non-competitive type of inhibition. Continuous fermentation of a glucose and xylose mixture with simultaneous acid removal by REED resulted in a two to threefold increase of the glucose consumption rate, while the xylose consumption rate was enhanced sixfold compared to continuous fermentation without in situ acid removal. Similarly, butyricacid productivity was enhanced by a factor of 2-3, while the yield remained unaffected. PMID:26516087

  2. Formulation and evaluation of microemulsion-based in situ ion-sensitive gelling systems for intranasal administration of curcumin.

    Wang, Shuang; Chen, Ping; Zhang, Lin; Yang, Chunfen; Zhai, Guangxi

    2012-12-01

    The purpose of our study was to develop a microemulsion-based in situ ion-sensitive gelling system for intranasal administration of curcumin. A new microemulsion composition for curcumin was optimized with the simple lattice design. And the microemulsion-based in situ ion-sensitive gelling system consisted of Capryol 90 as oil phase, Solutol HS15 as surfactant, Transcutol HP as cosurfactant and 0.3% DGG solution as water phase. The physicochemical properties such as morphology, droplet size distribution, zeta value and the in vitro release were investigated. In addition, the histological section studies on the reaction between the obtained formulation and nasal mucosa showed that the microemulsion-based in situ ion-sensitive gelling system could not produce obvious damage to nasal mucosa. The pharmacokinetics results showed that the absolute bioavailability of curcumin in the microemulsion-based in situ ion-sensitive gelling system was 55.82% by intranasal administration. And the brain targeting index (BTI) was 6.50, and in the tissue distribution experiment, the value of (AUC(brain)/AUC(blood)) following intranasal administration was higher than that following intravenous administration, suggesting that the obvious brain targeting property by nasal delivery be attributed to a direct nose-to-brain drug transport. It can be concluded that the microemulsion-based in situ gelling as an effective and safe vehicle could greatly enhance the in vivo absorption and facilitate the delivery of curcumin to brain by intranasal administration. PMID:22934854

  3. Toward biocompatible nuclear hyperpolarization using signal amplification by reversible exchange: quantitative in situ spectroscopy and high-field imaging.

    Hövener, Jan-Bernd; Schwaderlapp, Niels; Borowiak, Robert; Lickert, Thomas; Duckett, Simon B; Mewis, Ryan E; Adams, Ralph W; Burns, Michael J; Highton, Louise A R; Green, Gary G R; Olaru, Alexandra; Hennig, Jürgen; von Elverfeldt, Dominik

    2014-02-01

    Signal amplification by reversible exchange (SABRE) of a substrate and parahydrogen at a catalytic center promises to overcome the inherent insensitivity of magnetic resonance. In order to apply the new approach to biomedical applications, there is a need to develop experimental equipment, in situ quantification methods, and a biocompatible solvent. We present results detailing a low-field SABRE polarizer which provides well-controlled experimental conditions, defined spins manipulations, and which allows in situ detection of thermally polarized and hyperpolarized samples. We introduce a method for absolute quantification of hyperpolarization yield in situ by means of a thermally polarized reference. A maximum signal-to-noise ratio of ∼10(3) for 148 μmol of substance, a signal enhancement of 10(6) with respect to polarization transfer field of SABRE, or an absolute (1)H-polarization level of ≈10(-2) is achieved. In an important step toward biomedical application, we demonstrate (1)H in situ NMR as well as (1)H and (13)C high-field MRI using hyperpolarized pyridine (d3) and (13)C nicotinamide in pure and 11% ethanol in aqueous solution. Further increase of hyperpolarization yield, implications of in situ detection, and in vivo application are discussed. PMID:24397559

  4. Rapid Optical Characterization Suite for in situ Target Analysis of Rock Surfaces Project

    National Aeronautics and Space Administration ROCSTAR is an in situ instrument suite that can accomplish rapid mineral and molecular identification without sample preparation for in situ planetary exploration;...

  5. In-situ fluorometry for dispersant effectiveness monitoring

    Tan, S.H. [Oil Spill Response Ltd., Singapore, (Singapore)

    2009-07-01

    The use of chemical dispersant for oil spills on water is often a preferred response option because it reduces the overall environmental impact by reducing the likelihood of shoreline impact. Dispersants consist of a solvent carrier and a surfactant to enhance the natural dispersion processes of spilled oil. They generate large amounts of tiny oil droplets, producing a coffee-coloured plume under the water surface. When dispersant is applied, its effectiveness must be verified continually so that the response can be terminated as soon as the dispersant is no longer effective. This is normally done by visual observation, but this may be impaired due to poor weather or light conditions, high sediment content in waters and when dispersing pale-coloured oils. This paper demonstrated that advancement in detection and communication technology has made it possible to monitor dispersed oil in water column in a more scientific manner using instrumentation that provides real-time feedback to the incident command centre to help in the decision making process. Oil Spill Response Limited has acquired the capability to conduct in-situ fluorometry monitoring. The system consists of a solid state fluorometer, a laptop with built in global positioning system (GPS), a georeferencing software and satellite communication. The system provides a qualitative indication of a relative increase of oil in the water column, the location of monitoring points and high quality images that can be delivered to clients via Internet. This paper reported on results of a recent deployment of the system in an offshore oil response operation in Australia. The lessons learned were discussed along with the limitation and operational challenges of the system. Fluorometry was shown to be a sensitive but not necessarily accurate means of oil determination. 25 refs., 5 figs.

  6. In-situ fluorometry for dispersant effectiveness monitoring

    The use of chemical dispersant for oil spills on water is often a preferred response option because it reduces the overall environmental impact by reducing the likelihood of shoreline impact. Dispersants consist of a solvent carrier and a surfactant to enhance the natural dispersion processes of spilled oil. They generate large amounts of tiny oil droplets, producing a coffee-coloured plume under the water surface. When dispersant is applied, its effectiveness must be verified continually so that the response can be terminated as soon as the dispersant is no longer effective. This is normally done by visual observation, but this may be impaired due to poor weather or light conditions, high sediment content in waters and when dispersing pale-coloured oils. This paper demonstrated that advancement in detection and communication technology has made it possible to monitor dispersed oil in water column in a more scientific manner using instrumentation that provides real-time feedback to the incident command centre to help in the decision making process. Oil Spill Response Limited has acquired the capability to conduct in-situ fluorometry monitoring. The system consists of a solid state fluorometer, a laptop with built in global positioning system (GPS), a georeferencing software and satellite communication. The system provides a qualitative indication of a relative increase of oil in the water column, the location of monitoring points and high quality images that can be delivered to clients via Internet. This paper reported on results of a recent deployment of the system in an offshore oil response operation in Australia. The lessons learned were discussed along with the limitation and operational challenges of the system. Fluorometry was shown to be a sensitive but not necessarily accurate means of oil determination. 25 refs., 5 figs.

  7. Cold cap subsidence for in situ vitrification and electrodes therefor

    Buelt, James L.; Carter, John G.; Eschbach, Eugene A.; FitzPatrick, Vincent F.; Koehmstedt, Paul L.; Morgan, William C.; Oma, Kenton H.; Timmerman, Craig L.

    1992-01-01

    An electrode for use in in situ vitrification of soil comprises a molybdenum rod received within a conductive sleeve or collar formed of graphite. Electrodes of this type are placed on either side of a region containing buried waste material and an electric current is passed therebetween for vitrifying the soil between the electrodes. The graphite collar enhances the thermal conductivity of the electrode, bringing heat to the surface, and preventing the formation of a cold cap of material above the ground surface. The annulus between the molybdenum rod electrode and the graphite collar is filled with a conductive ceramic powder of a type that sinters upon the molybdenum rod, protecting the same from oxidation as the graphite material is consumed, or a metal powder which liquifies at operating temperatures. The molybdenum rod in the former case may be coated with an oxidation protectant, e.g. of molybdenum disilicide. As insulative blanket is suitably placed on the surface of the soil during processing to promote subsidence by allowing off-gassing and reducing surface heat loss. In other embodiments, connection to vitrification electrodes is provided below ground level to avoid loss of connection due to electrodes deterioration, or a sacrificial electrode may be employed when operation is started. Outboard electrodes can be utilized to square up the vitrified area. Further, the center of the molybdenum rod can be made hollow and filled with a powdered metal, such as copper, which liquifies at operating temperatures. In one embodiment, the molybdenum rod and the graphite collar are physically joined at the bottom.

  8. Chelator induced phytoextraction and in situ soil washing of Cu

    In a soil column experiment, we investigated the effect of 5 mmol kg-1 soil addition of citric acid, ethylenediamine tetraacetate (EDTA), diethylenetriamine-pentaacetate (DTPA) and [S,S]-stereoisomer of ethylenediamine-disuccinate (EDDS) on phytoextraction of Cu from a vineyard soil with 162.6 mg kg-1 Cu, into the test plant Brassica rapa var. pekinensis. We also examined the use of a horizontal permeable barrier, composed of layers of nutrient enriched sawdust and apatite, for reduction of chelator induced Cu leaching. The addition of all chelators, except citric acid, enhanced Cu mobility and caused leaching of 19.5-23% of initial total Cu from the soil column. However, Cu plant uptake did not increase accordingly; the most effective was the EDDS treatment, in which plant Cu concentration reached 37.81.3 mg kg-1 Cu and increased by 3.3-times over the control treatment. The addition of none of the chelators in the concentration range from 5 to 15 mmol kg-1 exerted any toxic effect on respiratory soil microorganisms. When EDDS was applied into the columns with horizontal permeable barriers, only 0.530.32% of the initial total Cu was leached. Cu (36.7%) was washed from the 18 cm soil layer above the barrier and accumulated in the barrier. Our results indicate that rather than for a reduction of Cu leaching during rather ineffective chelate induced Cu phytoextraction, horizontal permeable barriers could be more effective in a new remediation technique of controlled in situ soil washing of Cu with biodegradable chelates

  9. Chelator induced phytoextraction and in situ soil washing of Cu

    Kos, Bostjan; Lestan, Domen

    2004-11-01

    In a soil column experiment, we investigated the effect of 5 mmol kg{sup -1} soil addition of citric acid, ethylenediamine tetraacetate (EDTA), diethylenetriamine-pentaacetate (DTPA) and [S,S]-stereoisomer of ethylenediamine-disuccinate (EDDS) on phytoextraction of Cu from a vineyard soil with 162.6 mg kg{sup -1} Cu, into the test plant Brassica rapa var. pekinensis. We also examined the use of a horizontal permeable barrier, composed of layers of nutrient enriched sawdust and apatite, for reduction of chelator induced Cu leaching. The addition of all chelators, except citric acid, enhanced Cu mobility and caused leaching of 19.5-23% of initial total Cu from the soil column. However, Cu plant uptake did not increase accordingly; the most effective was the EDDS treatment, in which plant Cu concentration reached 37.8{+-}1.3 mg kg{sup -1} Cu and increased by 3.3-times over the control treatment. The addition of none of the chelators in the concentration range from 5 to 15 mmol kg{sup -1} exerted any toxic effect on respiratory soil microorganisms. When EDDS was applied into the columns with horizontal permeable barriers, only 0.53{+-}0.32% of the initial total Cu was leached. Cu (36.7%) was washed from the 18 cm soil layer above the barrier and accumulated in the barrier. Our results indicate that rather than for a reduction of Cu leaching during rather ineffective chelate induced Cu phytoextraction, horizontal permeable barriers could be more effective in a new remediation technique of controlled in situ soil washing of Cu with biodegradable chelates.

  10. Degradation of Bimetallic Model Electrocatalysts ___ an in situ XAS Study

    Friebel, Daniel

    2011-06-22

    One of the major challenges in the development of clean energy fuel cells is the performance degradation of the electrocatalyst, which, apart from poisoning effects, can suffer from corrosion due to its exposure to a harsh environment under high potentials. In this communication, we demonstrate how interactions of Pt with a transition metal support affect not only, as commonly intended, the catalytic activity, but also the reactivity of Pt towards oxide formation or dissolution. We use two well-defined single-crystal model systems, Pt/Rh(111) and Pt/Au(111) and a unique x-ray spectroscopy technique with enhanced energy resolution to monitor the potential-dependent oxidation state of Pt, and find two markedly different oxidation mechanisms on the two different substrates. This information can be of great significance for future design of more active and more stable catalysts. We have studied the potential-induced degradation of Pt monolayer model electrocatalysts on Rh(111) and Au(111) single-crystal substrates. The anodic formation of Pt oxides was monitored using in situ high energy resolution fluorescence detection x-ray absorption spectroscopy (HERFD XAS). Although Pt was deposited on both substrates in a three-dimensional island growth mode, we observed remarkable differences during oxide formation that can only be understood in terms of strong Pt-substrate interactions throughout the Pt islands. Anodic polarization of Pt/Rh(111) up to +1.6 V vs. RHE (reversible hydrogen electrode) leads to formation an incompletely oxidized passive layer, whereas formation of PtO2 and partial Pt dissolution is observed for Pt/Au(111).

  11. The ATLAS Glasgow Overview Week

    Richard Hawkings

    2007-01-01

    The ATLAS Overview Weeks always provide a good opportunity to see the status and progress throughout the experiment, and the July week at Glasgow University was no exception. The setting, amidst the traditional buildings of one of the UK's oldest universities, provided a nice counterpoint to all the cutting-edge research and technology being discussed. And despite predictions to the contrary, the weather at these northern latitudes was actually a great improvement on the previous few weeks in Geneva. The meeting sessions comprehensively covered the whole ATLAS project, from the subdetector and TDAQ systems and their commissioning, through to offline computing, analysis and physics. As a long-time ATLAS member who remembers plenary meetings in 1991 with 30 people drawing detector layouts on a whiteboard, the hardware and installation sessions were particularly impressive - to see how these dreams have been translated into 7000 tons of reality (and with attendant cabling, supports and services, which certainly...

  12. In-situ Analysis of Zinc Electrodeposition within an Ionic Liquid Electrolyte

    Keist, Jayme Scot

    Ionic liquids have received considerable attention as an alternative electrolyte for rechargeable battery systems. The goal of this investigation is to develop an understanding on the electrodeposition behavior of zinc within ionic liquid electrolytes and determine whether the unique properties of ionic liquids may allow for enhanced cyclability of the zinc electrode for rechargeable battery systems. Three different analysis techniques are employed for the investigation of the zinc deposition behavior within an imidazolium based ionic liquid electrolyte. First, the electrochemical behavior of the electrodeposition behavior is analyzed by cyclic voltammetry and potential step methods. Second, in-situ atomic force microscopy (AFM) is conducted to investigate the morphological evolution of zinc during electrodeposition. Finally, in-situ ultra-small-angle X-ray scattering (USAXS) is conducted during the electrodeposition of zinc to understand how the electrode surface evolves during electrodeposition and help confirm the results obtained from the in-situ AFM analysis. The ionic liquid electrolyte chosen for the investigation of zinc electrodeposition is an imidazolium based system consisting of zinc trifluoromethanesulfonate (Zn(OTf)2) dissolved within 1-butyl-3-methyl-imidazolium trifluoromethanesulfonate (BMIm OTf), and electrodeposition analysis is conducted on a Pt disk electrode. The behavior of Zn/Zn(II) within the ionic liquid electrolyte is analyzed at various deposition overpotentials, Zn(OTf)2 concentrations, and temperatures. Three distinct morphological behaviors are observed during the in-situ AFM analysis: growth of boulder like morphology, growth dominated by favorably oriented grains, and the formation of surface instabilities that manifested as agglomerate islands. The electrodeposition growth of Zn dominated by favorably oriented grains obtains a steady state where the surface roughness remained constant despite continued growth. The in-situ USAXS analysis confirms the results observed by the in-situ AFM analysis. In addition, the USAXS data shows that the zinc deposition behavior is hierarchical whereby the main scattering entities exhibited a sub-structure that remains constant in size with continued deposition. The results of this research indicate that zinc deposition within an ionic liquid electrolyte can obtain a compact and dense morphology. Furthermore, the morphology can evolve under a steady state condition under certain deposition parameters identified by this research. The improved deposition morphology of zinc within ionic liquid electrolytes may help improve the cycling performance of the zinc electrode and help make zinc based rechargeable batteries a viable alternative for energy storage applications.

  13. Evidence for the microbial in situ conversion of oil to methane in the Dagang oilfield

    Jimenez, N.; Richnow, H.H. [Helmholtz-Zentrum fuer Umweltforschung (UFZ), Leipzig (Germany). Abt. Isotopenbiogeochemie; Cai, M. [Helmholtz-Zentrum fuer Umweltforschung (UFZ), Leipzig (Germany). Abt. Isotopenbiogeochemie; University of Science and Technology, Beijing (China). School of Civil and Environment Engineering; Straaten, N.; Krueger, M. [Bundesanstalt fuer Geowissenschaften und Rohstoffe BGR Geozentrum (BGR), Hannover (Germany). Fachbereich Geochemie der Rohstoffe; Yao, Jun [University of Science and Technology, Beijing (China). School of Civil and Environment Engineering

    2013-08-01

    In situ biotransformation of oil to methane was investigated in a reservoir in Dagang, China using chemical fingerprinting, isotopic analyses, and molecular and biological methods. The reservoir is highly methanogenic despite chemical indications of advanced oil degradation, such as depletion of n-alkanes, alkylbenzenes, and light polycyclic aromatic hydrocarbon (PAHs) fractions or changes in the distribution of several alkylated polycyclic aromatic hydrocarbons. The degree of degradation strongly varied between different parts of the reservoir, ranging from severely degraded to nearly undegraded oil compositions. Geochemical data from oil, water and gas samples taken from the reservoir are consistent with in situ biogenic methane production linked to aliphatic and aromatic hydrocarbon degradation. Microcosms were inoculated with production and injection waters in order to characterize these processes in vitro. Subsequent degradation experiments revealed that autochthonous microbiota are capable of producing methane from {sup 13}C-labelled n-hexadecane or 2-methylnaphthalene, and suggest that further methanogenesis may occur from the aromatic and polyaromatic fractions of Dagang reservoir fluids. The microbial communities from produced oil-water samples were composed of high numbers of microorganisms (on the order to 10{sup 7}), including methane-producing Archaea within the same order of magnitude. In summary, the investigated sections of the Dagang reservoir may have significant potential for testing the viability of in situ conversion of oil to methane as an enhanced recovery method, and biodegradation of the aromatic fractions of the oil may be an important methane source. (orig.)

  14. Ex Situ and In Situ Conservation of Agricultural Biodiversity: Major Advances and Research Needs

    Mohammad Ehsan DULLOO

    2010-09-01

    Full Text Available The effective conservation and use of agricultural biodiversity is vital for creating and maintaining sustainable increases in the productivity of healthy food for mankind, as well as contributing to the increased resilience of agricultural systems. Major advances in the two main complementary strategies for agricultural biodiversity conservation, namely ex situ and in situ, over the last decade are presented to reflect on their current global status and trends. The FAO Second State of the World Report on Plant Genetic Resources for Food and Agriculture reports that the total number of accessions conserved in ex situ collections is about 7.4 million, in over 1750 genebanks around the world. There has also been increasing awareness of the importance and value of conserving crop wild relatives (CWR in situ and a greater understanding of the scientific issues surrounding on farm management of genetic diversity. Recent research outputs produced by Bioversity International to ensure the effective and efficient conservation and use of genetic diversity are cited. These have involved development of best practices for genebank management and the development of enhanced technologies and methodologies for conserving and promoting the use of the genetic diversity. Bioversity International has led the development of methodologies for on farm conservation, and promoted the drafting of policies and strategies for the in situ conservation of crop wild relatives and their management inside and outside protected areas. Also an outlook of the research priorities and needs for conservation and use of agricultural biodiversity is described.

  15. In search of in-situ radiocarbon in Law Dome ice and firn

    Smith, A.M. E-mail: ams@ansto.gov.au; Levchenko, V.A.; Etheridge, D.M.; Lowe, D.C.; Hua, Q.; Trudinger, C.M.; Zoppi, U.; Elcheikh, A

    2000-10-01

    Results of AMS radiocarbon measurements on CO and CO{sub 2} separated from firn air directly pumped from the ice sheet, and on CO{sub 2} separated from air extracted from ice cores by a dry grating technique, are presented. The firn air samples and ice cores used in this study were collected from the region of Law Dome, Antarctica. No evidence of in-situ {sup 14}CO{sub 2} was found in the firn air samples or the ice core air samples from one site although a slight enhancement of {sup 14}CO above expected polar atmospheric concentrations was observed for some firn air samples. A clear in-situ {sup 14}CO{sub 2} signal for ice pre-dating the radiocarbon bomb pulse was found, however, in air samples extracted from an ice core from a second site. We compare these results and propose an hypothesis to explain this apparent contradiction. The degree to which in-situ {sup 14}C is released from the ice crystals during trapping and bubble formation is considered and discussed. The selectivity of the dry grating technique for the extraction of trapped atmospheric gases from ice cores is also discussed and compared with other methods.

  16. In search of in-situ radiocarbon in Law Dome ice and firn

    Smith, A M; Etheridge, D M; Lowe, D C; Hua, Q; Trudinger, C M; Zoppi, U; El-Cheikh, A

    2000-01-01

    Results of AMS radiocarbon measurements on CO and CO sub 2 separated from firn air directly pumped from the ice sheet, and on CO sub 2 separated from air extracted from ice cores by a dry grating technique, are presented. The firn air samples and ice cores used in this study were collected from the region of Law Dome, Antarctica. No evidence of in-situ sup 1 sup 4 CO sub 2 was found in the firn air samples or the ice core air samples from one site although a slight enhancement of sup 1 sup 4 CO above expected polar atmospheric concentrations was observed for some firn air samples. A clear in-situ sup 1 sup 4 CO sub 2 signal for ice pre-dating the radiocarbon bomb pulse was found, however, in air samples extracted from an ice core from a second site. We compare these results and propose an hypothesis to explain this apparent contradiction. The degree to which in-situ sup 1 sup 4 C is released from the ice crystals during trapping and bubble formation is considered and discussed. The selectivity of the dry grat...

  17. In search of in-situ radiocarbon in Law Dome ice and firn

    Results of AMS radiocarbon measurements on CO and CO2 separated from firn air directly pumped from the ice sheet, and on CO2 separated from air extracted from ice cores by a dry grating technique, are presented. The firn air samples and ice cores used in this study were collected from the region of Law Dome, Antarctica. No evidence of in-situ 14CO2 was found in the firn air samples or the ice core air samples from one site although a slight enhancement of 14CO above expected polar atmospheric concentrations was observed for some firn air samples. A clear in-situ 14CO2 signal for ice pre-dating the radiocarbon bomb pulse was found, however, in air samples extracted from an ice core from a second site. We compare these results and propose an hypothesis to explain this apparent contradiction. The degree to which in-situ 14C is released from the ice crystals during trapping and bubble formation is considered and discussed. The selectivity of the dry grating technique for the extraction of trapped atmospheric gases from ice cores is also discussed and compared with other methods

  18. Influence of basement structures on in situ stresses over the Surat Basin, southeast Queensland

    Brooke-Barnett, Samuel; Flottmann, Thomas; Paul, Pijush K.; Busetti, Seth; Hennings, Peter; Reid, Ray; Rosenbaum, Gideon

    2015-07-01

    The Jurassic to Cretaceous sedimentary rocks of the Surat Basin in southeast Queensland host a significant volume of coal seam gas resources. Consequently, knowledge of the in situ stress is important for coal permeability enhancement and wellbore stability. Using wireline log data and direct stress measurements, we have calculated stress orientations from 36 wells and stress magnitudes from 7 wells across the Surat Basin. Our results reveal a relationship between high tectonic stress and proximity to structures within the underlying "basement" rocks. The influence of tectonic stresses is diminished with depth in areas with thicker sedimentary cover that are relatively far from the basement structures. We suggest that this relationship is due to the redistribution of in situ stresses around areas where basement is shallower and where basement structures, such as the Leichhardt-Burunga Fault System, are present. This behavior is explained by a lower rigidity in the thickest basin cover, which reduces the ability to maintain higher tectonic stress. Over the entire Surat Basin, a significant amount of variability in in situ stress orientation is observed. The authors attribute this stress variability to complex plate boundary interactions on the northern and eastern margins of the Indo-Australian Plate.

  19. Preparation and mechanical properties of in situ TiCx–Ni (Si, Ti) alloy composites

    Novel in situ TiCx reinforced Ni (Si, Ti) alloy composites with superior mechanical properties were prepared at 1250 °C for 30 min by pressureless sintering Ti3SiC2 (10 and 20 vol%) and Ni as precursors. The Ti3SiC2 particles decomposed into substoichiometric TiCx phase, while the additional Si and partial Ti atoms derived from Ti3SiC2 diffused into Ni matrix to form Ni (Si, Ti) alloy. The in situ formed TiCx phases are mainly dispersed on the grain boundaries of the Ni (Si, Ti) alloying, forming a strong skeleton and refining the microstructures of the metal matrix. The hardness, the yield stress σ0.2% and ultimate compressive strength of 20.6 vol%TiCx–Ni(Si, Ti) composite can reach 2.15±0.04 GPa, 466.8±55.8 MPa and 733.3±78.4 MPa, respectively. The enhanced mechanical properties of TiCx–Ni(Si, Ti) composites are due to the in situ formation of TiCx skeleton, the refined microstructures of Ni (Si, Ti) alloys and solid solution effects as well as good wettability between TiCx and Ni (Si, Ti) matrix

  20. Atomic Structure of Pt3Ni Nanoframe Electrocatalysts by in Situ X-ray Absorption Spectroscopy.

    Becknell, Nigel; Kang, Yijin; Chen, Chen; Resasco, Joaquin; Kornienko, Nikolay; Guo, Jinghua; Markovic, Nenad M; Somorjai, Gabor A; Stamenkovic, Vojislav R; Yang, Peidong

    2015-12-23

    Understanding the atomic structure of a catalyst is crucial to exposing the source of its performance characteristics. It is highly unlikely that a catalyst remains the same under reaction conditions when compared to as-synthesized. Hence, the ideal experiment to study the catalyst structure should be performed in situ. Here, we use X-ray absorption spectroscopy (XAS) as an in situ technique to study Pt3Ni nanoframe particles which have been proven to be an excellent electrocatalyst for the oxygen reduction reaction (ORR). The surface characteristics of the nanoframes were probed through electrochemical hydrogen underpotential deposition and carbon monoxide electrooxidation, which showed that nanoframe surfaces with different structure exhibit varying levels of binding strength to adsorbate molecules. It is well-known that Pt-skin formation on Pt-Ni catalysts will enhance ORR activity by weakening the binding energy between the surface and adsorbates. Ex situ and in situ XAS results reveal that nanoframes which bind adsorbates more strongly have a rougher Pt surface caused by insufficient segregation of Pt to the surface and consequent Ni dissolution. In contrast, nanoframes which exhibit extremely high ORR activity simultaneously demonstrate more significant segregation of Pt over Ni-rich subsurface layers, allowing better formation of the critical Pt-skin. This work demonstrates that the high ORR activity of the Pt3Ni hollow nanoframes depends on successful formation of the Pt-skin surface structure. PMID:26652294

  1. A sediment ecotoxicity assessment platform for in situ measures of chemistry, bioaccumulation and toxicity. Part 2: Integrated application to a shallow estuary

    A comprehensive, weight-of-evidence based ecological risk assessment approach integrating laboratory and in situ bioaccumulation and toxicity testing, passive sampler devices, hydrological characterization tools, continuous water quality sensing, and multi-phase chemical analyses was evaluated. The test site used to demonstrate the approach was a shallow estuarine wetland where groundwater seepage and elevated organic and inorganic contaminants were of potential concern. Although groundwater was discharging into the surficial sediments, little to no chemical contamination was associated with the infiltrating groundwater. Results from bulk chemistry analysis, toxicity testing, and bioaccumulation, however, suggested possible PAH toxicity at one station, which might have been enhanced by UV photoactivation, explaining the differences between in situ and laboratory amphipod survival. Concurrently deployed PAH bioaccumulation on solid-phase micro-extraction fibers positively correlated (r2 ? 0.977) with in situ PAH bioaccumulation in amphipods, attesting to their utility as biomimetics, and contributing to the overall improved linkage between exposure and effects demonstrated by this approach. - Highlights: ? In situ bioassays help improve linkages between exposure and effects. ? SEA Ring is an in situ assessment tool for characterizing sediment quality. ? In situ bioassays and physicochemical assessment tools can link exposure and effects. ? Groundwater seepage presented limited risk at estuarine sediment site. - In situ bioassays and multiple other concomitantly linked lines of evidence were valuable towards accurate characterization of ecological risk at an estuarine sediment site with groundwater seepage.

  2. IN SITU GEL FORMING INJECTABLE DRUG DELIVERY SYSTEM

    Amruta B. Kumbhar*, Ashwini K. Rakde, P.D. Chaudhari

    2013-02-01

    Full Text Available Recently, controlled and sustained drug delivery has become the standard in modern pharmaceutical design and an intensive research have been undertaken in achieving much better drug product effectiveness, reliability and safety. This interest has been sparked by the advantages shown by in situ gel forming drug delivery systems such as ease of administration and reduced frequency of administration, improved patient compliance and comfort. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various biodegradable polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL lactic acid, poly(DL-lactide-co-glycolide and poly-caprolactone. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. In situ gel forming injectable drug delivery system is the ability to inject a drug incorporated into a polymer to a localized site and have the polymer form a semi-solid gel drug depot has a number of advantages. Among these advantages is ease of application and localized, prolonged drug delivery. Biodegradable injectable in situ gel forming drug delivery systems represent an attractive alternative to microspheres, liposomes and emulsion as parenteral depot systems. For these reasons a large number of in situ gelling polymeric delivery systems have been developed and investigated for use in delivering a wide variety of drugs. The various strategies that have been used to prepare in situ gelling systems and outline their advantages and disadvantages as localized drug delivery systems. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost.

  3. In situ vitrification: application analysis for stabilization of transuranic waste

    Oma, K.H.; Farnsworth, R.K.; Rusin, J.M.

    1982-09-01

    The in situ vitrification process builds upon the electric melter technology previously developed for high-level waste immobilization. In situ vitrification converts buried wastes and contaminated soil to an extremely durable glass and crystalline waste form by melting the materials, in place, using joule heating. Once the waste materials have been solidified, the high integrity waste form should not cause future ground subsidence. Environmental transport of the waste due to water or wind erosion, and plant or animal intrusion, is minimized. Environmental studies are currently being conducted to determine whether additional stabilization is required for certain in-ground transuranic waste sites. An applications analysis has been performed to identify several in situ vitrification process limitations which may exist at transuranic waste sites. Based on the process limit analysis, in situ vitrification is well suited for solidification of most in-ground transuranic wastes. The process is best suited for liquid disposal sites. A site-specific performance analysis, based on safety, health, environmental, and economic assessments, will be required to determine for which sites in situ vitrification is an acceptable disposal technique. Process economics of in situ vitrification compare favorably with other in-situ solidification processes and are an order of magnitude less than the costs for exhumation and disposal in a repository. Leachability of the vitrified product compares closely with that of Pyrex glass and is significantly better than granite, marble, or bottle glass. Total release to the environment from a vitrified waste site is estimated to be less than 10/sup -5/ parts per year. 32 figures, 30 tables.

  4. In situ vitrification: application analysis for stabilization of transuranic waste

    The in situ vitrification process builds upon the electric melter technology previously developed for high-level waste immobilization. In situ vitrification converts buried wastes and contaminated soil to an extremely durable glass and crystalline waste form by melting the materials, in place, using joule heating. Once the waste materials have been solidified, the high integrity waste form should not cause future ground subsidence. Environmental transport of the waste due to water or wind erosion, and plant or animal intrusion, is minimized. Environmental studies are currently being conducted to determine whether additional stabilization is required for certain in-ground transuranic waste sites. An applications analysis has been performed to identify several in situ vitrification process limitations which may exist at transuranic waste sites. Based on the process limit analysis, in situ vitrification is well suited for solidification of most in-ground transuranic wastes. The process is best suited for liquid disposal sites. A site-specific performance analysis, based on safety, health, environmental, and economic assessments, will be required to determine for which sites in situ vitrification is an acceptable disposal technique. Process economics of in situ vitrification compare favorably with other in-situ solidification processes and are an order of magnitude less than the costs for exhumation and disposal in a repository. Leachability of the vitrified product compares closely with that of Pyrex glass and is significantly better than granite, marble, or bottle glass. Total release to the environment from a vitrified waste site is estimated to be less than 10-5 parts per year. 32 figures, 30 tables

  5. A sediment ecotoxicity assessment platform for in situ measures of chemistry, bioaccumulation and toxicity. Part 1: System description and proof of concept

    In situ-based testing using aquatic organisms has been widely reported, but is often limited in scope and practical usefulness in making decisions on ecological risk and remediation. To provide this capability, an integrated deployment system, the Sediment Ecotoxicity Assessment (SEA) Ring was developed, which incorporates rapid in situ hydrological, chemical, bioaccumulation, and toxicological Lines-of-Evidence (LoE) for assessing sediment and overlying water contamination. The SEA Ring system allows for diver-assisted, or diverless, deployment of multiple species of ecologically relevant and indigenous organisms in three different exposures (overlying water, sediment–water interface, and bulk sediment) for periods ranging from two days to three weeks, in a range of water systems. Measured endpoints were both sublethal and lethal effects as well as bioaccumulation. In addition, integrated passive sampling devices for detecting nonpolar organics (solid phase micro-extraction fibers) and metals (diffusive gradients in thin films) provided gradient measures in overlying waters and surficial sediments. - Highlights: ▶ In situ bioassays help improve linkages between exposure and effects. ▶ SEA Ring is an in situ assessment tool for characterizing sediment quality. ▶ In situ bioassays and physicochemical assessment tools can link exposure and effects. ▶ Groundwater seepage presented limited risk at estuarine sediment site. - An in situ platform was created for evaluating the exposure and effects to multiple aquatic species.

  6. Demonstration testing and evaluation of in situ soil heating. Treatability study work plan (Revision 2)

    A Treatability Study planned for the demonstration of the in situ electromagnetic (EM) heating process to remove organic solvents is described in this Work Plan. The treatability study will be conducted by heating subsurface vadose-zone soils in an organic plume adjacent to the Classified Burial Ground K-1070-D located at K-25 Site, Oak Ridge. The test is scheduled to start during the fourth quarter of FY94 and will be completed during the first quarter of FY95. Over the last nine years, a number of Government agencies (EPA, Army, AF, and DOE) and industries sponsored further development and testing of the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site under the proposed treatability study. Most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 degrees to 95 degrees C. The efficiency of the treatment will be determined by comparing the concentration of contaminants in soil samples. Samples will be obtained before and after the demonstration for a measurement of the concentration of contaminants of concern. This document is a Treatability Study Work Plan for the demonstration program. The document contains a description of the proposed treatability study, background of the EM heating process, description of the field equipment, and demonstration test design

  7. In situ acoustic and laboratory ultrasonic sound speed and attenuation measured in heterogeneous soft seabed sediments: Eel River shelf, California

    Gorgas, T.J.; Wilkens, R.H.; Fu, S.S.; Neil, Frazer L.; Richardson, M.D.; Briggs, K.B.; Lee, H.

    2002-01-01

    We compared in situ and laboratory velocity and attenuation values measured in seafloor sediments from the shallow water delta of the Eel River, California. This region receives a substantial volume of fluvial sediment that is discharged annually onto the shelf. Additionally, a high input of fluvial sediments during storms generates flood deposits that are characterized by thin beds of variable grain-sizes between the 40- and 90-m isobaths. The main objectives of this study were (1) to investigate signatures of seafloor processes on geoacoustic and physical properties, and (2) to evaluate differences between geoacoustic parameters measured in situ at acoustic (7.5 kHz) and in the laboratory at ultrasonic (400 kHz) frequencies. The in situ acoustic measurements were conducted between 60 and 100 m of water depth. Wet-bulk density and porosity profiles were obtained to 1.15 m below seafloor (m bsf) using gravity cores of the mostly cohesive fine-grained sediments across- and along-shelf. Physical and geoacoustic properties from six selected sites obtained on the Eel margin revealed the following. (1) Sound speed and wet-bulk density strongly correlated in most cases. (2) Sediment compaction with depth generally led to increased sound speed and density, while porosity and in situ attenuation values decreased. (3) Sound speed was higher in coarser- than in finer-grained sediments, on a maximum average by 80 m s-1. (4) In coarse-grained sediments sound speed was higher in the laboratory (1560 m s-1) than in situ (1520 m s-1). In contrast, average ultrasonic and in situ sound speed in fine-grained sediments showed only little differences (both approximately 1480 m s-1). (5) Greater attenuation was commonly measured in the laboratory (0.4 and 0.8 dB m-1 kHz-1) than in situ (0.02 and 0.65 dB m-1 kHz-1), and remained almost constant below 0.4 m bsf. We attributed discrepancies between laboratory ultrasonic and in situ acoustic measurements to a frequency dependence of velocity and attenuation. In addition, laboratory attenuation was most likely enhanced due to scattering of sound waves at heterogeneities that were on the scale of ultrasonic wavelengths. In contrast, high in situ attenuation values were linked to stratigraphic scattering at thin-bed layers that form along with flood deposits. ?? 2002 Published by Elsevier Science B.V.

  8. Synthesis and characterization of in situ formed titanium diboride particulate reinforced AA7075 aluminum alloy cast composites

    Highlights: ► Fabrication of AA7075/TiB2 AMC by in situ reaction K2TiF6 and KBF4 salts. ► Most of the TiB2 particles were located in inter granular regions. ► Uniform distribution of TiB2 particles having clear interface and good bonding. ► TiB2 particles displayed various shapes such as cubic, spherical and hexagonal. ► TiB2 particles enhanced the mechanical properties of the AMC. -- Abstract: In situ fabrication of aluminum matrix composites (AMCs) has gathered widespread attention of researchers due to inherent advantages over ex situ methods. Aluminum alloy AA7075 reinforced with various amounts (0, 3, 6 and 9 wt.%) of TiB2 particles were prepared by the in situ reaction of inorganic salts such as K2TiF6 and KBF4 to molten aluminum. X-ray diffraction patterns of the prepared AMCs clearly revealed the formation of TiB2 particles without the presence of any other intermetallic compounds. The microstructures of the AMCs were studied using optical and scanning electron microscopy. The in situ formed TiB2 particles were characterized with uniform distribution, clear interface, good bonding and various shapes such as cubic, spherical and hexagonal. The formation of TiB2 particles enhanced the microhardness and ultimate tensile strength (UTS) of the AMCs.

  9. Multisite high resolution measurements of carbon monoxide along Greenland ice cores: evidence for in-situ production and potential for atmospheric reconstruction

    Fan, Xavier; Chappellaz, Jrme; Rhodes, Rachael; Stowasser, Christopher; Blunier, Thomas; McConnell, Joseph; Brook, Edward; Desbois, Thibault; Romanini, Daniele

    2014-05-01

    Carbon monoxide (CO) is the principal sink for hydroxyl radicals (OH) in the troposphere. Consequently, changes in atmospheric CO levels can considerably perturb the oxidizing capacity of the atmosphere, affecting mixing ratios of a host of chemical species oxidized by OH, including methane. In addition, CO variations (and changes in its stable isotopic composition) are expected to be good tracers of changes in biomass burning emissions. Investigating past mixing ratios of carbon monoxide is thus a promising approach towards reducing uncertainty related to the past oxidative capacity of the atmosphere and biogeochemical cycling of methane. Recent developments in optical spectrometry (Optical Feedback Cavity Enhanced Absorption Spectrometry, OFCEAS), combined with continuous flow analysis (CFA) systems, allow efficient, precise measurements of CO concentrations in ice cores. Coupling our OFCEAS spectrometer with the CFA melter operated at DRI (Reno, USA) provided the first continuous CO measurements along the NEEM (Greenland) core covering the last 1800 yr at an unprecedented resolution. Although the most recent section of this record (i.e., since 1700 AD) agreed with existing discrete CO measurements from the Eurocore ice core and the deep NEEM firn, it was difficult to interpret in terms of atmospheric CO variation due to high frequency, high amplitudes spikes related to in-situ production (Fan et al., Climate of the Past Discussion). During a recent 8-week analytical campaign, three different ice archives from Greenland were melted on the DRI CFA and analyzed continuously for CO with the OFCEAS spectrometer: (i) the D4 core (spanning the last 170 yr), (ii) the NEEM core (extending the existing record from 200 AD to 800 BC), and (iii) the Tunu core (spanning the last 1800 yr). Although in-situ production of CO is observed at all sites, these new records reveal different CO patterns and trends. This multisite approach allows us to better characterize the processes involved in CO in-situ production by evaluating the influence of site-specific factors such as surface accumulation rate (10, 22 and 41 cm ice yr-1 for Tunu, NEEM, and D4 respectively), surface temperature, or aerosols loading (with e.g., median black carbon concentration ranging from 0.9 to 2.3 ng g-1 among the investigated sites). However, a quantitative understanding of the past evolution of atmospheric CO above Greenland remains challenging due to the existence of these artifacts.

  10. Impact of in Situ Isolated Bacterial Strains on Nitrogen Fixation in Alfalfa

    Carmen Dragomir

    2013-05-01

    Full Text Available Symbiosis relationships among legumes and nitrogen fixing bacteria play a crucial role in agriculture since they provide the opportunity of converting atmospheric molecular nitrogen into an ammonia form of nitrogen that the plants can use in protein formation. To enhance this process we have selected nitrogen fixing bacterial strains commercialised under different forms depending on the cultivation technologies in legume species. In our research, we have pointed out the efficacy of in situ isolated nitrogen fixing bacteria in alfalfa in two ways: rhizobia taken directly from the nodosities on the alfalfa roots and rhizobia taken from the alfalfa root system.

  11. Fiber optic Raman spectrograph for in situ environmental monitoring. Final report

    Carrabba, M.M. [EIC Labs., Inc., Norwood, MA (United States)

    1992-11-01

    This report discusses the development and testing of a small laboratory prototype, field Raman spectrometer which can be used with a fiber optic sampling probe incorporting substrates tailored for surface enhanced Raman spectroscopy (SERS) for low level detection of chemical species. The report also discusses demonstration of apparatus for both laboratory and field environmental samples typical of DOE environmental restoration sites. Preliminary results establish a new technique which can be used in,the field to identify and profile in situ a wide variety of pollutants at the action levels required for remediation.

  12. In situ strengthening of thin-wall structures using pressurized foam

    Ashrafi, M.; Woodsum, C.J.; Papadopoulos, J; Hamouda, Abdelmagid S.; Nayeb-Hashemi, H.; Vaziri, A.

    2015-01-01

    A simple and effective in situ method for strengthening or healing thin-wall structures is presented. In this method, a liquid-state gap-sealing foam is injected within the enclosed spaces of a structure. After injection it expands to fill and pressurize the cavities, then solidifies in few hours. The stiff pressurized foam enhances load carrying capacity both by supporting part of the load, and by retarding the buckling of thin-wall structural components. A simple demonstration of the propos...

  13. Methods of producing alkylated hydrocarbons from an in situ heat treatment process liquid

    Roes, Augustinus Wilhelmus Maria; Mo, Weijian; Muylle, Michel Serge Marie; Mandema, Remco Hugo; Nair, Vijay

    2009-09-01

    A method for producing alkylated hydrocarbons is disclosed. Formation fluid is produced from a subsurface in situ heat treatment process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. The liquid stream is fractionated to produce at least a second gas stream including hydrocarbons having a carbon number of at least 3. The first gas stream and the second gas stream are introduced into an alkylation unit to produce alkylated hydrocarbons. At least a portion of the olefins in the first gas stream enhance alkylation.

  14. In situ transmission electron microscope observation of the formation of fuzzy structures on tungsten

    To investigate the formation processes of tungsten nano-structures, so called fuzz, in situ transmission electron microscope observations during helium ion irradiation and high temperature annealing have been performed. The irradiation with 3keVHe+ from room temperature to 1273K is found to cause high-density helium bubbles in tungsten with no significant change in the surface structure. At higher temperatures, surface morphology changes were observed even without helium irradiation due probably to surface diffusion of tungsten atoms driven by surface tension. It is clearly shown that this morphology change is enhanced with helium irradiation, i.e. the formation of helium bubbles. (paper)

  15. A quantitative framework for understanding complex interactions between competing interfacial processes and in situ biodegradation

    Johnson, Mark A.; Song, Xin; Seagren, Eric A.

    2013-03-01

    In situ bioremediation of contaminated groundwater is made technologically challenging by the physically, chemically, and biologically heterogeneous subsurface environment. Subsurface heterogeneities are important because of influences on interfacial mass transfer processes that impact the availability of substrates to microorganisms. The goal of this study was to perform a "proof-of-concept" evaluation of the utility of a quantitative framework based on a set of dimensionless coefficients for evaluating the effects of competing physicochemical interfacial and biokinetic processes at the field scale. First, three numerical modeling experiments were completed, demonstrating how the framework can be used to identify the rate-limiting process for the overall bioremediation rate, and to predict what engineered enhancements will alleviate the rate-limiting process. Baseline conditions for each scenario were established to examine intrinsic biodegradation with a given rate-limiting process (either dispersion, biokinetics, or sorption). Then different engineering treatments were examined. In each case, the treatment predicted to be appropriate for addressing the overall rate-limiting process based on the quantitative framework alleviated the limitation more successfully, and enhanced the in situ biodegradation rate more than the alternative enhancements. Second, the quantitative framework was applied to a series of large-scale laboratory and field-scale experiments, using reported parameter estimates to calculate the relevant dimensionless coefficients and predict the rate-limiting process(es). Observations from the studies were then used to evaluate those predictions.

  16. In situ Measurements of Phytoplankton Fluorescence Using Low Cost Electronics

    Dana L. Wright

    2013-06-01

    Full Text Available Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open source sharing of architecture and software will allow students to reconstruct and customize the sensor on a small budget. Research applications that require numerous in situ fluorometers or expendable fluorometers can also benefit from this study. The sensor costs US$150.00 and can be constructed with little to no previous experience. The sensor uses a blue LED to excite chlorophyll a and measures fluorescence using a silicon photodiode. The sensor is controlled by an Arduino microcontroller that also serves as a data logger.

  17. Nanoparticles laden in situ gel for sustained ocular drug delivery

    Himanshu Gupta

    2013-01-01

    Full Text Available Proper availability of drug on to corneal surface is a challenging task. However, due to ocular physiological barriers, conventional eye drops display poor ocular bioavailability of drugs (< 1%. To improve precorneal residence time and ocular penetration, earlier our group developed and evaluated in situ gel and nanoparticles for ocular delivery. In interest to evaluate the combined effect of in situ gel and nanoparticles on ocular retention, we combined them. We are the first to term this combination as "nanoparticle laden in situ gel", that is, poly lactic co glycolic acid nanoparticle incorporated in chitosan in situ gel for sparfloxacin ophthalmic delivery. The formulation was tested for various physicochemical properties. It showed gelation pH near pH 7.2. The observation of acquired gamma camera images showed good retention over the entire precorneal area for sparfloxacin nanoparticle laden in situ gel (SNG as compared to marketed formulation. SNG formulation cleared at a very slow rate and remained at corneal surface for longer duration as no radioactivity was observed in systemic circulation. The developed formulation was found to be better in combination and can go up to the clinical evaluation and application.

  18. Management of Adenocarcinoma In Situ of Cervix in Pregnancy

    Alireza Abidi

    2008-03-01

    Full Text Available Adenocarcinoma in situ is one of the premalignant lesions of the cervix and its incidence is believed to be increasing while the pathogenesis of the disease is not clearly understood. Management of Adenocarcinoma in situ (AIS unlike carcinoma in situ (CIS has not been clearly described in the current literature. Here we describe conservative management and serial colposcopy of two pregnant women with adenocarcinoma in situ of the cervix. Both of the cases were diagnosed initially with abnormal Pap smears and were confirmed by colposcopic directed biopsy. None of the patients agreed with any invasive procedure during pregnancy and both of them were followed with serial colposcopy. None of the lesions showed any evidence of progression. All cases underwent cold knife cone biopsies in their postpartum period. Hysterectomy as the final treatment has been done in both cases with no evidence of progression of the disease during pregnancy. We concluded that adenocarcinoma in situ of the cervix during pregnancy could be managed conservatively with definite treatment postponed till after delivery.

  19. Room-temperature in situ nuclear spin hyperpolarization from optically pumped nitrogen vacancy centres in diamond

    King, Jonathan P.; Jeong, Keunhong; Vassiliou, Christophoros C.; Shin, Chang S.; Page, Ralph H.; Avalos, Claudia E.; Wang, Hai-Jing; Pines, Alexander

    2015-12-01

    Low detection sensitivity stemming from the weak polarization of nuclear spins is a primary limitation of magnetic resonance spectroscopy and imaging. Methods have been developed to enhance nuclear spin polarization but they typically require high magnetic fields, cryogenic temperatures or sample transfer between magnets. Here we report bulk, room-temperature hyperpolarization of 13C nuclear spins observed via high-field magnetic resonance. The technique harnesses the high optically induced spin polarization of diamond nitrogen vacancy centres at room temperature in combination with dynamic nuclear polarization. We observe bulk nuclear spin polarization of 6%, an enhancement of ~170,000 over thermal equilibrium. The signal of the hyperpolarized spins was detected in situ with a standard nuclear magnetic resonance probe without the need for sample shuttling or precise crystal orientation. Hyperpolarization via optical pumping/dynamic nuclear polarization should function at arbitrary magnetic fields enabling orders of magnitude sensitivity enhancement for nuclear magnetic resonance of solids and liquids under ambient conditions.

  20. In Situ Sensors for the Chemical Industry- Final Report

    Tate, J.D.; Knittel, Trevor

    2006-06-30

    The project focused on analytical techniques that can be applied in situ. The innovative component of this project is the focus on achieving a significant breakthrough in two of the three primary Process Analytical (PA) fields. PA measurements can roughly be broken down into: ? Single component measurements, ? Multiple component measurements and ? Multiple component isomer analysis. This project targeted single component measurements and multiple component measurements with two basic technologies, and to move these measurements to the process, achieving many of the process control needs. During the project the following achievements were made: ? Development of a low cost Tunable Diode Laser (TDL) Analyzer system for measurement of 1) Oxygen in process and combustion applications, 2) part per million (ppm) H2O impurities in aggressive service, 3) ppm CO in large scale combustion systems. This product is now commercially available ? Development of a process pathlength enhanced (high sensitivity) Laser Based Analyzer for measurement of product impurities. This product is now commercially available. ? Development of signal processing methods to eliminate measurement errors in complex and changing backgrounds (critical to chemical industry measurements). This development is incorporated into 2 commercially available products. ? Development of signal processing methods to allow multi-component measurements in complex chemical streams. This development is incorporated into 2 commercially available products. ? Development of process interface designs to allow in-situ application of TDL technology in aggressive (corrosive, high temperature, high pressure) commonly found in chemical processes. This development is incorporated in the commercially available ASI TDL analyzer. ? Field proving of 3 laser-based analyzer systems in process control and combustion applications at Dow Chemical. Laser based analyzers have been available for >5yrs, however significant product price/performance issues have minimized their applicability in the chemical industry. In order to take advantage of the promise of this technology a number of technology advances were required, within price limits for market acceptance. This project significantly advanced the state of TDL technology for application in chemical industry applications. With these advances a commercially available product now exists that has already achieved market success and is installed in critical applications. The ability to make fast, sensitive and accurate measurements inside the chemical processes is now delivering improved process control, energy efficiency and emissions control within the U.S. Chemical Industry. Despite the success we enjoyed for the laser-based sensors, there were significant technical barriers for the solid-state sensors. With exception of a generic close-coupled extractive housing and electronics interface, there were significant issues with all of the solid-state sensor devices we sought to develop and test. Ultimately, these issues were roadblocks that prevented further development and testing. The fundamental limitations of available sensor materials that we identified, formulated and tested were overwhelming. This situation forced our team to cancel these portions of the project and focus our resources on laser-based sensor techniques. The barriers of material compatibility, sensitivity, speed of response, chemical interferences, etc. are surmountable in the field of solid-state sensors. Inability to address any single one of these attributes will prevent wide-implementation into this market. This situation is plainly evident by the lack of such devices in the online analyzer market (for petrochemicals).