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Sample records for submicron scale previous

  1. Microscopic imaging ellipsometry of submicron-scale bacterial cells ...

    African Journals Online (AJOL)

    Microscopic imaging ellipsometry of submicron-scale bacterial cells. ... Conclusion: MIE is a sensitive non-optical technique that can be used to image biological systems without the need for labeling of molecules. Keywords: Objective plane, Imaging ellipsometry, Submicron-scale bacterial cells, Streptococcus mutans, ...

  2. Acoustic Emission Patterns and the Transition to Ductility in Sub-Micron Scale Laboratory Earthquakes

    Science.gov (United States)

    Ghaffari, H.; Xia, K.; Young, R.

    2013-12-01

    We report observation of a transition from the brittle to ductile regime in precursor events from different rock materials (Granite, Sandstone, Basalt, and Gypsum) and Polymers (PMMA, PTFE and CR-39). Acoustic emission patterns associated with sub-micron scale laboratory earthquakes are mapped into network parameter spaces (functional damage networks). The sub-classes hold nearly constant timescales, indicating dependency of the sub-phases on the mechanism governing the previous evolutionary phase, i.e., deformation and failure of asperities. Based on our findings, we propose that the signature of the non-linear elastic zone around a crack tip is mapped into the details of the evolutionary phases, supporting the formation of a strongly weak zone in the vicinity of crack tips. Moreover, we recognize sub-micron to micron ruptures with signatures of 'stiffening' in the deformation phase of acoustic-waveforms. We propose that the latter rupture fronts carry critical rupture extensions, including possible dislocations faster than the shear wave speed. Using 'template super-shear waveforms' and their network characteristics, we show that the acoustic emission signals are possible super-shear or intersonic events. Ref. [1] Ghaffari, H. O., and R. P. Young. "Acoustic-Friction Networks and the Evolution of Precursor Rupture Fronts in Laboratory Earthquakes." Nature Scientific reports 3 (2013). [2] Xia, Kaiwen, Ares J. Rosakis, and Hiroo Kanamori. "Laboratory earthquakes: The sub-Rayleigh-to-supershear rupture transition." Science 303.5665 (2004): 1859-1861. [3] Mello, M., et al. "Identifying the unique ground motion signatures of supershear earthquakes: Theory and experiments." Tectonophysics 493.3 (2010): 297-326. [4] Gumbsch, Peter, and Huajian Gao. "Dislocations faster than the speed of sound." Science 283.5404 (1999): 965-968. [5] Livne, Ariel, et al. "The near-tip fields of fast cracks." Science 327.5971 (2010): 1359-1363. [6] Rycroft, Chris H., and Eran Bouchbinder

  3. Effective Use of Focused Ion Beam (FIB) in Investigating Fundamental Mechanical Properties of Metals at the Sub-Micron Scale

    OpenAIRE

    Greer, Julia R.

    2006-01-01

    Recent advances in the 2-beam focused ion beams technology (FIB) have enabled researchers to not only perform high-precision nanolithography and micro-machining, but also to apply these novel fabrication techniques to investigating a broad range of materials' properties at the submicron and nano-scales. In our work, the FIB is utilized in manufacturing of sub-micron cylinders, or nano-pillars, as well as of TEM cross-sections to directly investigate plasticity of metals at thes...

  4. Accurate submicron edge detection using the phase change of a nano-scale shifting laser spot

    Science.gov (United States)

    Hai, Hoang Hong; Chen, Liang-Chia; Nguyen, Duc Trung; Lin, Shyh-Tsong; Yeh, Sheng Lih; Yao, Ying

    2017-07-01

    Accurate edge detection with lateral super-resolution has been a critical issue in optical measurement because of the barrier imposed by the optical diffraction limit. In this study, a diffraction model that applies scalar diffraction theory of Fresnel-Kirchhoff is developed to simulate phase variance and distribution along edge location. Edge position is detected based on the phase variation that occurs on the edge with a surface step-height jump. To detect accurate edge positioning beyond the optical diffraction limit, a nanopositioning stage is used to scan the super steep edge of a single-edge and multi-edges submicron grating with nano-scale, and its phase distribution is captured. Model simulation is performed to confirm the phase-shifting phenomenon of the edge. A phase-shifting detection algorithm is developed to spatially detect the edge when a finite step scanning with a pitch of several tenth nanometers is used. A 180 nm deviation can occur during detection when the step height of the detecting edge varies, or the detecting laser spot covers more than one edge. Preliminary experimental results show that for the edge detection of the submicron line width of the grating, the standard deviation of the optical phase difference detection measurement is 38 nm. This technique provides a feasible means to achieve optical super-resolution on micro-grating measurement.

  5. Large-scale self-assembly of uniform submicron silver sulfide material driven by precise pressure control

    Science.gov (United States)

    Qi, Juanjuan; Chen, Ke; Zhang, Shuhao; Yang, Yun; Guo, Lin; Yang, Shihe

    2017-03-01

    The controllable self-assembly of nanosized building blocks into larger specific structures can provide an efficient method of synthesizing novel materials with excellent properties. The self-assembly of nanocrystals by assisted means is becoming an extremely active area of research, because it provides a method of producing large-scale advanced functional materials with potential applications in the areas of energy, electronics, optics, and biologics. In this study, we applied an efficient strategy, namely, the use of ‘pressure control’ to the assembly of silver sulfide (Ag2S) nanospheres with a diameter of approximately 33 nm into large-scale, uniform Ag2S sub-microspheres with a size of about 0.33 μm. More importantly, this strategy realizes the online control of the overall reaction system, including the pressure, reaction time, and temperature, and could also be used to easily fabricate other functional materials on an industrial scale. Moreover, the thermodynamics and kinetics parameters for the thermal decomposition of silver diethyldithiocarbamate (Ag(DDTC)) are also investigated to explore the formation mechanism of the Ag2S nanosized building blocks which can be assembled into uniform sub-micron scale architecture. As a method of producing sub-micron Ag2S particles by means of the pressure-controlled self-assembly of nanoparticles, we foresee this strategy being an efficient and universally applicable option for constructing other new building blocks and assembling novel and large functional micromaterials on an industrial scale.

  6. Atmospheric pressure plasma assisted calcination by the preparation of TiO2 fibers in submicron scale

    Science.gov (United States)

    Medvecká, Veronika; Kováčik, Dušan; Zahoranová, Anna; Černák, Mirko

    2018-01-01

    Atmospheric pressure plasma assisted calcination by the preparation of TiO2 submicron fibers as a low-temperature alternative to the conventional thermal annealing was studied. A special type of dielectric barrier discharge was used for plasma treatment of hybrid titanium butoxide/polyvinylpyrrolidone (Ti(Bu)/PVP) fibers prepared by forcespinning to decompose and oxidize the base polymer and precursor. The obtained fibers were characterized by changes in chemical bonds on the surface using Fourier Transform Infrared Spectroscopy (FTIR), chemical composition by using Energy-Dispersive X-Ray Spectroscopy (EDX), X-ray Photoelectron Spectroscopy (XPS). The morphology of fibers was investigated by Scanning Electron Microscopy (SEM). A significant decrease of organic components was reached by short plasma exposure times less than 1 h. The obtained fibers exhibit a high surface porosity without degradation of the fibrous structure. The results obtained indicate that atmospheric pressure plasma assisted calcination can be a viable low-temperature, energy- and time-saving alternative or pre-treatment method for the conventional high-temperature thermal calcination.

  7. In situ visualisation and characterisation of the capacity of highly reactive minerals to preserve soil organic matter (SOM) in colloids at submicron scale.

    Science.gov (United States)

    Xiao, Jian; Wen, Yongli; Li, Huan; Hao, Jialong; Shen, Qirong; Ran, Wei; Mei, Xinlan; He, Xinhua; Yu, Guanghui

    2015-11-01

    Mineral-organo associations (MOAs) are a mixture of identifiable biopolymers associated with highly reactive minerals and microorganisms. However, the in situ characterization and correlation between soil organic matter (SOM) and highly reactive Al and Fe minerals are still unclear for the lack of technologies, particularly in the long-term agricultural soil colloids at submicron scale. We combined several novel techniques, including nano-scale secondary ion mass spectrometry (NanoSIMS), X-ray absorption near edge structure (XANES) and confocal laser scanning microscopy (CLSM) to characterise the capacity of highly reactive Al and Fe minerals to preserve SOM in Ferralic Cambisol in south China. Our results demonstrated that: (1) highly reactive minerals were strongly related to SOM preservation, while SOM had a more significant line correlation with the highly reactive Al minerals than the highly reactive Fe minerals, according to the regions of interest correlation analyses using NanoSIMS; (2) allophane and ferrihydrite were the potential mineral species to determine the SOM preservation capability, which was evaluated by the X-ray photoelectron spectroscopy (XPS) and Fe K-edge XANES spectroscopy techniques; and (3) soil organic biopolymers with dominant compounds, such as proteins, polysaccharides and lipids, were distributed at the rough and clustered surface of MOAs with high chemical and spatial heterogeneity according to the CLSM observation. Our results also promoted the understanding of the roles played by the highly reactive Al and Fe minerals in the spatial distribution of soil organic biopolymers and SOM sequestration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Rapid Antibiotic Susceptibility Testing of Uropathogenic E. coli by Tracking Submicron Scale Motion of Single Bacterial Cells.

    Science.gov (United States)

    Syal, Karan; Shen, Simon; Yang, Yunze; Wang, Shaopeng; Haydel, Shelley E; Tao, Nongjian

    2017-08-25

    To combat antibiotic resistance, a rapid antibiotic susceptibility testing (AST) technology that can identify resistant infections at disease onset is required. Current clinical AST technologies take 1-3 days, which is often too slow for accurate treatment. Here we demonstrate a rapid AST method by tracking sub-μm scale bacterial motion with an optical imaging and tracking technique. We apply the method to clinically relevant bacterial pathogens, Escherichia coli O157: H7 and uropathogenic E. coli (UPEC) loosely tethered to a glass surface. By analyzing dose-dependent sub-μm motion changes in a population of bacterial cells, we obtain the minimum bactericidal concentration within 2 h using human urine samples spiked with UPEC. We validate the AST method using the standard culture-based AST methods. In addition to population studies, the method allows single cell analysis, which can identify subpopulations of resistance strains within a sample.

  9. Transglutaminase-induced or citric acid-mediated cross-linking of whey proteins to tune the characteristics of subsequently desolvated sub-micron and nano-scaled particles.

    Science.gov (United States)

    Bagheri, Leila; Yarmand, Mohammadsaeed; Madadlou, Ashkan; Mousavi, Mohammad E

    2014-01-01

    Whey proteins were inter-connected either by the enzyme transglutaminase or citric acid and then desolvated with ethanol to generate particles. Both samples comprised of sub-micron (>300 nm) and nano-scaled (~100 nm) particles based on the hydrodynamic size measurements. Enzyme-induced cross-linking of proteins yielded more monodisperse particles and decreased the mean size of the major (nano-scaled) fraction of particles. Scanning electron microscopy images revealed a spherical morphology for all samples with mean sizes of particles from enzymatically cross-linked proteins. The mediating role of citric acid in bridging the proteins was confirmed by Fourier transform infrared spectroscopy. Differential scanning calorimetry indicated that pre-heating of protein solution before cross-linking and desolvation denatured the proteins entirely. In vitro degradation of whey protein particles in a simulated gastric fluid demonstrated that cross-linking of whey proteins before desolvation stage enhanced significantly the digestion stability of particles.

  10. Scaling down the two-dimensional electron gas spin resonance (ESR) phenomena in GaAs/AlGaAs heterostructures to sub-micron samples

    Science.gov (United States)

    Bandaru, Prabhakar; Yablonovitch, Eli; Jiang, Hong-Wen

    2002-03-01

    Electron Spin Resonance (ESR) has been proposed as a technique for achieving single electron and subsequently single spin control, important for the emerging fields of spintronics and quantum computing. In this paper, we report on ESR in the quantum Hall regime, of sub-micron structures containing a few hundred electrons. These phenomena are contrasted with ESR phenomena in structures containing 10^7 - 10^9 electrons, which have been performed so far (Reference 1). There are several novel features observed in the ESR of small structures, such as a very large decrease of resistance and shift in the quantum Hall minima to lower magnetic fields after the resonance. These imply a reduction in the number of electrons and could result from the greater influence of the surface and impurity potential fluctuations intrinsic to a small sample. The ESR peak intensity is hypothesized to result from the transfer of electrons from the localized states to the extended states. References: 1.H.W.Jiang and E. Yablonovitch, Phys. Rev.B., 64, R041307, (2001) 2.M.Dobers, K.v. Klitzing and G. Weimann,Phys. Rev. B, 38, 5453, (1988).

  11. Droplet fragmentation: 3D imaging of a previously unidentified pore-scale process during multiphase flow in porous media.

    Science.gov (United States)

    Pak, Tannaz; Butler, Ian B; Geiger, Sebastian; van Dijke, Marinus I J; Sorbie, Ken S

    2015-02-17

    Using X-ray computed microtomography, we have visualized and quantified the in situ structure of a trapped nonwetting phase (oil) in a highly heterogeneous carbonate rock after injecting a wetting phase (brine) at low and high capillary numbers. We imaged the process of capillary desaturation in 3D and demonstrated its impacts on the trapped nonwetting phase cluster size distribution. We have identified a previously unidentified pore-scale event during capillary desaturation. This pore-scale event, described as droplet fragmentation of the nonwetting phase, occurs in larger pores. It increases volumetric production of the nonwetting phase after capillary trapping and enlarges the fluid-fluid interface, which can enhance mass transfer between the phases. Droplet fragmentation therefore has implications for a range of multiphase flow processes in natural and engineered porous media with complex heterogeneous pore spaces.

  12. Submicron-Scale Control of the Three-Dimensional Modes 1, 2, and 3 of Targets Imploded in the Direct-Drive Configuration on OMEGA

    Science.gov (United States)

    Michel, D. T.; Igumenshchev, I. V.; Davis, A. K.; Edgell, D. H.; Froula, D. H.; Goncharov, V. N.; Jacobs-Perkins, D. W.; Regan, S. P.; Shvydky, A.; Campbell, E. M.

    2017-10-01

    Reducing low-mode nonuniformities has been identified as a critical step to demonstrate conditions for laser-direct-drive targets that are hydrodynamically equivalent to ignition when scaled to the megajoule energies at the National Ignition Facility. The 3-D shape of the imploding target was tomographically recorded using four lines-of-sight x-ray measurements of the ablation front. The projected ablation-front contours during the implosion phase were measured with framing cameras using the x-ray self-emission shadowgraphy technique. The projected ablation-front motions were obtained by comparing the positions of the contours on the framing cameras with the corresponding contour positions measured on a nonimploding solid CH ball shot. The amplitudes of the modes were determined within +/-0.15% by decomposition into spherical harmonics of the contours oriented perpendicular to the lines-of-sight and shifted by the measured motions. The variations of the amplitudes in modes 1, 2, and 3 between shots were shown to change linearly (within +/-0.25%) with the variations of the mode amplitudes of the laser beam energy balance making it possible to compensate the residual target modes (that remain when the laser is balanced) within 1%. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  13. Chemical mapping of proterozoic organic matter at submicron spatial resolution.

    Science.gov (United States)

    Oehler, Dorothy Z; Robert, François; Mostefaoui, Smail; Meibom, Anders; Selo, Madeleine; McKay, David S

    2006-12-01

    A NanoSIMS ion microprobe was used to map the submicron-scale distributions of carbon, nitrogen, sulfur, silicon, and oxygen in organic microfossils and laminae in a thin section of the approximately 0.85 billion year old Bitter Springs Formation of Australia. The data provide clues about the original chemistry of the microfossils, the silicification process, and the biosignatures of specific microorganisms and microbial communities. Chemical maps of fossil unicells and filaments revealed distinct wall- and sheath-like structures enriched in C, N, and S, consistent with their accepted biological origin. Surprisingly, organic laminae, previously considered to be amorphous, also exhibited filamentous and apparently compressed spheroidal structures defined by strong enrichments in C, N, and S. By analogy to NanoSIMS data from the well-preserved microfossils, these structures were interpreted as being of biological origin, most likely representing densely packed remnants of microbial mats. Given that the preponderance of organic matter in Precambrian sediments is similarly "amorphous," our findings indicate that a re-evaluation of ancient specimens via in situ structural, chemical, and isotopic study is warranted. Our analyses have led us to propose new criteria for assessing the biogenicity of problematic kerogenous materials, and, thus, these criteria can be applied to assessments of poorly preserved or fragmentary organic residues in early Archean sediments and any that might occur in meteorites or other extraterrestrial samples.

  14. Scanning SQUID susceptometers with sub-micron spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Kirtley, John R., E-mail: jkirtley@stanford.edu; Rosenberg, Aaron J.; Palmstrom, Johanna C.; Holland, Connor M.; Moler, Kathryn A. [Department of Applied Physics, Stanford University, Stanford, California 94305-4045 (United States); Paulius, Lisa [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Spanton, Eric M. [Department of Physics, Stanford University, Stanford, California 94305-4045 (United States); Schiessl, Daniel [Attocube Systems AG, Königinstraße 11A, 80539 Munich (Germany); Jermain, Colin L.; Gibbons, Jonathan [Department of Physics, Cornell University, Cornell, Ithaca, New York 14853 (United States); Fung, Y.-K.K.; Gibson, Gerald W. [IBM Research Division, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Huber, Martin E. [Department of Physics, University of Colorado Denver, Denver, Colorado 80217-3364 (United States); Ralph, Daniel C. [Department of Physics, Cornell University, Cornell, Ithaca, New York 14853 (United States); Kavli Institute at Cornell, Ithaca, New York 14853 (United States); Ketchen, Mark B. [OcteVue, Hadley, Massachusetts 01035 (United States)

    2016-09-15

    Superconducting QUantum Interference Device (SQUID) microscopy has excellent magnetic field sensitivity, but suffers from modest spatial resolution when compared with other scanning probes. This spatial resolution is determined by both the size of the field sensitive area and the spacing between this area and the sample surface. In this paper we describe scanning SQUID susceptometers that achieve sub-micron spatial resolution while retaining a white noise floor flux sensitivity of ≈2μΦ{sub 0}/Hz{sup 1/2}. This high spatial resolution is accomplished by deep sub-micron feature sizes, well shielded pickup loops fabricated using a planarized process, and a deep etch step that minimizes the spacing between the sample surface and the SQUID pickup loop. We describe the design, modeling, fabrication, and testing of these sensors. Although sub-micron spatial resolution has been achieved previously in scanning SQUID sensors, our sensors not only achieve high spatial resolution but also have integrated modulation coils for flux feedback, integrated field coils for susceptibility measurements, and batch processing. They are therefore a generally applicable tool for imaging sample magnetization, currents, and susceptibilities with higher spatial resolution than previous susceptometers.

  15. On the dry deposition of submicron particles

    Energy Technology Data Exchange (ETDEWEB)

    Wesely, M. L.

    1999-10-08

    The air-surface exchange of particles can have a strong role in determining the amount, size, and chemical composition of particles in the troposphere. Here the authors consider only dry processes (deposition processes not directly aided by precipitation) and mostly address particles less than about 2 {micro}m in diameter (often referred to as submicron particles because most of such particles are less than 1 {micro}m in diameter). The processes that control the dry exchange of particulate material between the atmosphere and the surface of the Earth are numerous, highly varied, and sometimes poorly understood. As a result, determining which of the surface processes to parameterize or simulate in modeling the tropospheric mass budget of a particulate substance can be a significant challenge. Dry deposition, for example, can be controlled by a combination of Brownian diffusion, impaction, interception, and gravitational settling, depending on the size of the particles, the roughness of the surface on both micrometeorological and microscopic scales, the geometrical structure of vegetative canopies, and other surface characteristics such as wetness. Particles can be added to the lower atmosphere by resuspension from land surfaces and sea spray. The roles of rapid gas-to-particle conversion and growth or shrinkage of particles as a result of water condensation or evaporation in the lower few meters of the atmosphere can also have a significant impact on particle concentrations in the lower atmosphere. Here, a few micrometeorological observations and inferences on particle air-surface exchange are briefly addressed.

  16. Measuring Basic Needs Satisfaction: Evaluating Previous Research and Conducting New Psychometric Evaluations of the Basic Needs Satisfaction in General Scale

    Science.gov (United States)

    Johnston, Mary M.; Finney, Sara J.

    2010-01-01

    Self-Determination Theory specifies the existence of three basic psychological needs: autonomy, competence, and relatedness. The current set of studies (a) provides a narrative review of past research on the Basic Needs Satisfaction in General Scale, (b) examines its dimensionality which has been assumed but not empirically studied, and (c)…

  17. Surfactants and submicron sea spray generation

    NARCIS (Netherlands)

    Sellegri, K.; O'Dowd, C.D.; Yoon, Y.J.; Jennings, S.G.; Leeuw, G. de

    2006-01-01

    Laboratory experiments have been carried out to elucidate the role of surfactants on the primary marine aerosol production of submicron marine aerosols. A synthetic surfactant SDS was used in conjunction with artificially generated seawater, and the resultant bubble-mediated aerosol produced was

  18. Fabrication and characterization of submicron polymer waveguides by micro-transfer molding

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Te-Wei [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    Various methods exist for fabrication of micron and submicron sized waveguide structures. However, most of them include expensive and time consuming semiconductor fabrication techniques. An economical method for fabricating waveguide structures is introduced and demonstrated in this thesis. This method is established based on previously well-developed photonic crystal fabrication method called two-polymer microtransfer molding. The waveguide in this work functions by a coupler structure that diffracts the incident light into submicron polymer rods. The light is then guided through the rods. Characterization is done by collecting the light that has been guided through the waveguide and exits the end of these submicron polymer bars. The coupling and waveguiding capabilities are demonstrated using two light sources, a laser and white light.

  19. Micromagnetic Simulations of Submicron Cobalt Dots

    Energy Technology Data Exchange (ETDEWEB)

    Parker, G.J.; Cerjan, C.

    1999-08-30

    Numerical simulations of submicron Co extruded elliptical dots were performed to illustrate the relative importance of different physical parameters on the switching behavior in the easy direction. Shape, size, magnetic moment magnitude and crystalline anisotropy, both magnitude and distribution, were varied. The simulation includes calculation of the magnetostatic, exchange and crystalline anisotropy fields on a structured mesh using finite difference techniques. The smooth boundary of the dots are accurately represented by use of the Embedded Curve Boundary method.

  20. Submicron Surface-Patterned Fibers and Textiles

    Science.gov (United States)

    2016-11-04

    The patterned fiber surface behaves as an optical diffraction grating when the feature size is comparable with visible light wavelengths. A red laser...the optical fiber gratings For the first diffraction order of the micron and submicron patterned fiber , we utilize the formula α tanh (where s...e) SEM images of patterned PMMA fiber are depicted. The inset shows the cross- section of this fiber . Submitted to 20 Figure S3

  1. A Novel Leakage-tolerant Domino Logic Circuit With Feedback From Footer Transistor In Ultra Deep Submicron CMOS

    DEFF Research Database (Denmark)

    Moradi, Farshad; Peiravi, Ali; Mahmoodi, Hamid

    As the CMOS manufacturing process scales down into the ultra deep sub-micron regime, the leakage current becomes an increasingly more important consideration in VLSI circuit design. In this paper, a high speed and noise immune domino logic circuit is presented which uses the property of the footer...... transistor to alleviate the sensitivity of the dynamic node to noise and results in improved performance. The new circuit has been added to conventional footed standard domino logic for highly improving leakage tolerance, especially at the beginning of the evaluation phase. According to simulation results...... obtained using the 70nm Berkeley predictive models, our proposed circuit increases the noise immunity by least 2times compared to previous circuits...

  2. High Proportions of Sub-micron Particulate Matter in Icelandic Dust Storms in 2015

    Science.gov (United States)

    Dagsson Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur; Magnusdottir, Agnes

    2017-04-01

    Iceland is extremely active dust region and desert areas of over 44,000 km2 acknowledge Iceland as the largest Arctic and European desert. Frequent dust events, up to 135 dust days annually, transport dust particles far distances towards the Arctic and Europe. Satellite MODIS pictures have revealed dust plumes exceeding 1,000 km. The annual dust deposition was calculated as 40.1 million tons yr-1. Two dust storms were measured in transverse horizontal profile about 90 km far from different dust sources in southwestern Iceland in the summer of 2015. Aerosol monitor DustTrak DRX 8533EP was used to measure PM mass concentrations corresponding to PM1, PM2.5, PM4, PM10 and the total PM15 at several places within the dust plume. Images from camera network operated by the Icelandic Road and Coastal Administration were used to estimate the visibility and spatial extent of measured dust events. A numerical simulation of surface winds was carried out with the numerical model HIRLAM with horizontal resolution of 5 km and used to calculate the total dust flux from the sources. The in situ measurements inside the dust plumes showed that aeolian dust can be very fine. The study highlights that suspended volcanic dust in Iceland causes air pollution with extremely high PM1 concentrations comparable to the polluted urban stations in Europe or Asia rather than reported dust event observations from around the world. The PM1/PM2.5 ratios are generally low during dust storms outside of Iceland, much lower than > 0.9 and PM1/PM10 ratios of 0.34-0.63 found in our study. It shows that Icelandic volcanic dust consists of higher proportion of submicron particles compared to crustal dust. The submicron particles are predicted to travel long distances. Moreover, such submicron particles pose considerable health risk because of high potential for entering the lungs. Icelandic volcanic glass has often fine pipe-vesicular structures known from asbestos and high content of heavy metals. Previous

  3. Laser direct writing using submicron-diameter fibers.

    Science.gov (United States)

    Tian, Feng; Yang, Guoguang; Bai, Jian; Xu, Jianfeng; Hou, Changlun; Liang, Yiyong; Wang, Kaiwei

    2009-10-26

    In this paper, a novel direct writing technique using submicron-diameter fibers is presented. The submicron-diameter fiber probe serves as a tightly confined point source and it adopts micro touch mode in the process of writing. The energy distribution of direct writing model is analyzed by Three-Dimension Finite-Difference Time-Domain method. Experiments demonstrate that submicron-diameter fiber direct writing has some advantages: simple process, 350-nm-resolution (lower than 442-nm-wavelength), large writing area, and controllable width of lines. In addition, by altering writing direction of lines, complex submicron patterns can be fabricated.

  4. A Facile Method for Separating and Enriching Nano and Submicron Particles from Titanium Dioxide Found in Food and Pharmaceutical Products.

    Science.gov (United States)

    Faust, James J; Doudrick, Kyle; Yang, Yu; Capco, David G; Westerhoff, Paul

    2016-01-01

    Recent studies indicate the presence of nano-scale titanium dioxide (TiO2) as an additive in human foodstuffs, but a practical protocol to isolate and separate nano-fractions from soluble foodstuffs as a source of material remains elusive. As such, we developed a method for separating the nano and submicron fractions found in commercial-grade TiO2 (E171) and E171 extracted from soluble foodstuffs and pharmaceutical products (e.g., chewing gum, pain reliever, and allergy medicine). Primary particle analysis of commercial-grade E171 indicated that 54% of particles were nano-sized (i.e., particle analysis of five consumer goods intended to be ingested revealed differences in the percent of nano-sized particles from 32%‒58%. Separation and enrichment of nano- and submicron-sized particles from commercial-grade E171 and E171 isolated from foodstuffs and pharmaceuticals was accomplished using rate-zonal centrifugation. Commercial-grade E171 was separated into nano- and submicron-enriched fractions consisting of a nano:submicron fraction of approximately 0.45:1 and 3.2:1, respectively. E171 extracted from gum had nano:submicron fractions of 1.4:1 and 0.19:1 for nano- and submicron-enriched, respectively. We show a difference in particle adhesion to the cell surface, which was found to be dependent on particle size and epithelial orientation. Finally, we provide evidence that E171 particles are not immediately cytotoxic to the Caco-2 human intestinal epithelium model. These data suggest that this separation method is appropriate for studies interested in isolating the nano-sized particle fraction taken directly from consumer products, in order to study separately the effects of nano and submicron particles.

  5. In situ quantitative measurement of concentration profiles in a microreactor with submicron resolution using multiplex CARS microscopy

    NARCIS (Netherlands)

    Schafer, D.; Squier, J.A.; van Maarseveen, J.; Bonn, D.; Bonn, M.; Müller, M.

    2008-01-01

    In situ quantitative imaging of concentration profiles of reactants and products inside a microfluidic reactor is achieved, with submicron spatial resolution with similar to mM sensitivity and on similar to ms time scales, for a given position. The label-free approach relies on quantitative

  6. Zirconia nanocrystals as submicron level biological label

    Science.gov (United States)

    Smits, K.; Liepins, J.; Gavare, M.; Patmalnieks, A.; Gruduls, A.; Jankovica, D.

    2012-08-01

    Inorganic nanocrystals are of increasing interest for their usage in biology and pharmacology research. Our interest was to justify ZrO2 nanocrystal usage as submicron level biological label in baker's yeast Saccharomyces cerevisia culture. For the first time (to our knowledge) images with sub micro up-conversion luminescent particles in biologic media were made. A set of undoped as well as Er and Yb doped ZrO2 samples at different concentrations were prepared by sol-gel method. The up-conversion luminescence for free standing and for nanocrystals with baker's yeast cells was studied and the differences in up-conversion luminescence spectra were analyzed. In vivo toxic effects of ZrO2 nanocrystals were tested by co-cultivation with baker's yeast.

  7. CHARACTERISATION AND MEASUREMENT TO THE SUB-MICRON SCALE OF A REFERENCE WIRE POSITION CARACTERISATION ET MESURE SUB-MICROMETRIQUE DE LA POSITION D’UN FIL DE REFERENCE

    CERN Document Server

    SANZ , Claude; MAINAUD DURAND , Hélène; MORANTZ , Paul; SHORE , Paul

    2015-01-01

    L’étude suivante est réalisée dans le cadre du projet PACMAN (a study on Particle Accelerator Components Metrology and Alignment to the Nanometre scale) : une étude sur la métrologie et l’alignement à l’échelle nanométrique des composants d’un accélérateur de particules. C’est un programme Marie Curie supporté par la Commission Européenne et hébergé par le CERN. Le but de ce programme est de faire travailler en équipe de jeunes chercheurs sur le développement d’un banc de pré-alignement pour l’accélérateur linéaire CLIC (Compact Linear Collider). Sur ce banc, chaque composant sera aligné au niveau requis en une seule opération basée sur l’utilisation d’un fil tendu. Pendant cette opération, le fil matérialisera les axes magnétiques et électriques des composants, c’est-à-dire qu’il sera à la position théorique du faisceau de particules. Puis il servira de référence et la position de son axe sera mesurée avec autant de précision que possible par une machin...

  8. Directed assembly of conducting polymers on sub-micron templates by electrical fields

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Jia; Wei, Ming [National Science Foundation (NSF) Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Busnaina, Ahmed [National Science Foundation (NSF) Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, Northeastern University, Boston, MA 02115 (United States); Barry, Carol [National Science Foundation (NSF) Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Mead, Joey, E-mail: Joey_Mead@uml.edu [National Science Foundation (NSF) Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, University of Massachusetts Lowell, Lowell, MA 01854 (United States)

    2013-02-20

    Highlights: Black-Right-Pointing-Pointer Nanoscale patterns with dimensions of assembled PANi down to 100 nm were fabricated. Black-Right-Pointing-Pointer We use electrophoretic and dielectrophoretic assembly to deposit PANi. Black-Right-Pointing-Pointer Electrophoretic and dielectrophoretic assembly of PANi finished in less than 1 min. Black-Right-Pointing-Pointer Effect of process parameters on assembly of PANi onto nanoscale pattern was studied. Black-Right-Pointing-Pointer The assembled PANi can be transferred to other flexible substrates. - Abstract: Patterning of conducting polymer into sub-micron patterns over large areas at high rate and low cost is significant for commercial manufacturing of novel devices. Electrophoretic and dielectrophoretic assembly provide an easily scaled approach with high fabrication rates. In this work, electrophoretic and dielectrophoretic assembly were used to assemble polyaniline (PANi) into multiscale sub-micron size patterns in less than 1 min. The process was controlled by assembly time, amplitude, and frequency of the electric field. Dielectrophoretic assembly is preferable for manufacturing as it reduces damage to the templates used to control the assembly. Using this method, sub-micron patterns with dimensions of the assembled PANi down to 100 nm were fabricated over large areas in short times. The assembled PANi was further transferred to other flexible polymer substrates by a thermoforming process, providing a fast, easily controlled and promising approach for fabrication of nanoscale devices.

  9. Submicron Emulsions and Their Applications in Oral Delivery.

    Science.gov (United States)

    Mundada, Veenu; Patel, Mitali; Sawant, Krutika

    2016-01-01

    A "submicron emulsion" is an isotropic mixture of drug, lipids, and surfactants, usually with hydrophilic cosolvents and with droplet diameters ranging from 10 to 500 nm. Submicron emulsions are of increasing interest in medicine due to their kinetic stability, high solubilizing capacity, and tiny globule size. Because of these properties, they have been applied in various fields, such as personal care, cosmetics, health care, pharmaceuticals, and agrochemicals. Submicron emulsions are by far the most advanced nanoparticulate systems for the systemic delivery of biologically active agents for controlled drug delivery and targeting. They are designed mainly for pharmaceutical formulations suitable for various routes of administration like parenteral, ocular, transdermal, and oral. This review article describes the marked potential of submicron emulsions for oral drug delivery owing to their numerous advantages like reduced first pass metabolism, inhibition of P-glycoprotein efflux system, and enhanced absorption via intestinal lymphatic pathway. To overcome the limitations of liquid dosage forms, submicron emulsions can be formulated into solid dosage forms such as solid self-emulsifying systems. This article covers various types of submicron emulsions like microemulsion, nanoemulsion, and self-emulsifying drug delivery system (SEDDS), and their potential pharmaceutical applications in oral delivery with emphasis on their advantages, limitations, and advancements.

  10. Submicron Features in Higher Manganese Silicide

    Directory of Open Access Journals (Sweden)

    Yatir Sadia

    2013-01-01

    Full Text Available The world energy crisis had increased the demand for alternative energy sources and as such is one of the topics at the forefront of research. One way for reducing energy consumption is by thermoelectricity. Thermoelectric effects enable direct conversion of thermal into electrical energy. Higher manganese silicide (HMS, MnSi1.75 is one of the promising materials for applications in the field of thermoelectricity. The abundance and low cost of the elements, combined with good thermoelectric properties and high mechanical and chemical stability at high temperatures, make it very attractive for thermoelectric applications. Recent studies have shown that Si-rich HMS has improved thermoelectric properties. The most interesting of which is the unusual reduction in thermal conductivity. In the current research, transmission (TEM and scanning (SEM electron microscopy as well as X-ray diffraction methods were applied for investigation of the govern mechanisms resulting in very low thermal conductivity values of an Si-rich HMS composition, following arc melting and hot-pressing procedures. In this paper, it is shown that there is a presence of sub-micron dislocations walls, stacking faults, and silicon and HMS precipitates inside each other apparent in the matrix, following a high temperature (0.9 Tm hot pressing for an hour. These are not just responsible for the low thermal conductivity values observed but also indicate the ability to create complicate nano-structures that will last during the production process and possibly during the application.

  11. Microscopic imaging ellipsometry of submicron-scale bacterial cells

    African Journals Online (AJOL)

    Raman spectroscopy and MIE provide different but complementary information of the sample. MIE can detect very thin layers and measure their precise thickness, while Raman spectroscopy is sensitive to the chemical nature ... consists of three main components: laser arm, sample stage, and detector arm as shown in.

  12. Subdecadal-scale vegetation responses to a previously unknown late-Allerød climate fluctuation and Younger Dryas cooling at Lake Meerfelder Maar (Germany)

    NARCIS (Netherlands)

    Engels, S.; Brauer, A.; Buddelmeijer, N.; Martín-Puertas, C.; Rach, O.; Sachse, D.; van Geel, B.

    2016-01-01

    Lake Meerfelder Maar (MFM) is the northernmost Western European sediment record with annual laminations across the Younger Dryas (YD), and the onset of the YD in the record of MFM has previously been defined as an increase in non-arboreal pollen abundance at ca. 12 680 varve a BP. Here we present a

  13. Optical Response to Submicron Digital Elements Simulated by FDTD Wavelets with Refractive Impulse

    Directory of Open Access Journals (Sweden)

    Antony J. Bourdillon

    2014-01-01

    Full Text Available Accurate simulation from digital, submicron, optical elements is obtained by finite difference time domain (FDTD results that are phase analyzed as sources for Huygens wavelets on fine scales much shorter than the wavelength used. Results, from the MIT electromagnetic evaluation program, are renormalized by a method here called “refractive impulse.” This is valid for polarized responses from digital diffractive and focusing optics. The method is employed with plane wave incidence at any angle or with diverging or converging beams. It is more systematic, more versatile, and more accurate than commercial substitutes.

  14. Electrospun submicron bioactive glass fibers for bone tissue scaffold.

    Science.gov (United States)

    Lu, H; Zhang, T; Wang, X P; Fang, Q F

    2009-03-01

    Submicron bioactive glass fibers 70S30C (70 mol% SiO(2), 30 mol% CaO) acting as bone tissue scaffolds were fabricated by electrospinning method. The scaffold is a hierarchical pore network that consists of interconnected fibers with macropores and mesopores. The structure, morphological characterization and mechanical properties of the submicron bioactive glass fibers were studied by XRD, EDS, FIIR, SEM, N(2) gas absorption analyses and nanoindentation. The effect of the voltage on the morphology of electrospun bioactive glass fibers was investigated. It was found that decreasing the applied voltage from 19 to 7 kV can facilitate the formation of finer fibers with fewer bead defects. The hardness and Young's modulus of submicron bioactive glass fibers were measured as 0.21 and 5.5 GPa, respectively. Comparing with other bone tissue scaffolds measured by nanoindentation, the elastic modulus of the present scaffold was relatively high and close to the bone.

  15. NATO Advanced Study Institute on Physics of Submicron Semiconductor Devices

    CERN Document Server

    Ferry, David; Jacoboni, C

    1988-01-01

    The papers contained in the volume represent lectures delivered as a 1983 NATO ASI, held at Urbino, Italy. The lecture series was designed to identify the key submicron and ultrasubmicron device physics, transport, materials and contact issues. Nonequilibrium transport, quantum transport, interfacial and size constraints issues were also highlighted. The ASI was supported by NATO and the European Research Office. H. L. Grubin D. K. Ferry C. Jacoboni v CONTENTS MODELLING OF SUB-MICRON DEVICES.................. .......... 1 E. Constant BOLTZMANN TRANSPORT EQUATION... ... ...... .................... 33 K. Hess TRANSPORT AND MATERIAL CONSIDERATIONS FOR SUBMICRON DEVICES. . .. . . . . .. . . . .. . .. . .... ... .. . . . .. . . . .. . . . . . . . . . . 45 H. L. Grubin EPITAXIAL GROWTH FOR SUB MICRON STRUCTURES.................. 179 C. E. C. Wood INSULATOR/SEMICONDUCTOR INTERFACES.......................... 195 C. W. Wilms en THEORY OF THE ELECTRONIC STRUCTURE OF SEMICONDUCTOR SURFACES AND INTERFACES...................

  16. Magnetic and Optical Properties of Submicron-Size Hollow Spheres

    Directory of Open Access Journals (Sweden)

    Hirofumi Yoshikawa

    2010-02-01

    Full Text Available Magnetic hollow spheres with a controlled diameter and shell thickness have emerged as an important class of magnetic nanomaterials. The confined hollow geometry and pronouncedly curved surfaces induce unique physical properties different from those of flat thin films and solid counterparts. In this paper, we focus on recent progress on submicron-size spherical hollow magnets (e.g., cobalt- and iron-based materials, and discuss the effects of the hollow shape and the submicron size on magnetic and optical properties.

  17. An introduction to deep submicron CMOS for vertex applications

    CERN Document Server

    Campbell, M; Cantatore, E; Faccio, F; Heijne, Erik H M; Jarron, P; Santiard, Jean-Claude; Snoeys, W; Wyllie, K

    2001-01-01

    Microelectronics has become a key enabling technology in the development of tracking detectors for High Energy Physics. Deep submicron CMOS is likely to be extensively used in all future tracking systems. Radiation tolerance in the Mrad region has been achieved and complete readout chips comprising many millions of transistors now exist. The choice of technology is dictated by market forces but the adoption of deep submicron CMOS for tracking applications still poses some challenges. The techniques used are reviewed and some of the future challenges are discussed.

  18. Bloch-Wave Engineered Submicron Diameter Micropillars with Quality Factors Exceeding 10,000

    DEFF Research Database (Denmark)

    Hofling, S.; Lermer, M.; Gregersen, Niels

    2011-01-01

    Adiabatic design submicron diameter quantum-dot micropillars have been designed and implemented for cavity quantum electrodynamics experiments. Ultra-high experimental quality factors (>10,000) are obtained for submicron diameters and strong light-matter interaction is observed.......Adiabatic design submicron diameter quantum-dot micropillars have been designed and implemented for cavity quantum electrodynamics experiments. Ultra-high experimental quality factors (>10,000) are obtained for submicron diameters and strong light-matter interaction is observed....

  19. Submicron particles of Co, Ni and Co–Ni alloys

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 24; Issue 5 ... Magnetic Materials Volume 24 Issue 5 October 2001 pp 515-521 ... Magnetic sub-micron sized particles (with diameters in the range 100–600 nm) of Co, Ni and Co–Ni alloys, protected with polyvinylpyrrolidone have been prepared in gram quantities ...

  20. UV Light–Induced Aggregation of Titania Submicron Particles

    Directory of Open Access Journals (Sweden)

    Can Zhou

    2016-11-01

    Full Text Available In this study, aggregation of TiO2 (rutile and anatase submicron particles in deionized (DI water under ultra-violet (UV light irradiation was investigated. While no aggregation was observed in the dark, rutile and anatase submicron particles started aggregating upon application of UV light and ceased aggregation in about 2 and 8.4 h, respectively. It has been demonstrated that UV light directly mitigated the particle mobility of TiO2, resulting in a neutralization effect of the Zeta potential. It was also observed that rutile particles aggregated much faster than anatase particles under UV radiation, indicating that the Zeta potential of as-prepared rutile is less than that of anatase in deionized (DI water. In addition, the interaction energy of rutile and anatase particles was simulated using the Derjaguin–Landau–Verwey–Overbeek (DLVO model. The results showed a significant reduction of barrier energy from 118.2 kBT to 33.6 kBT for rutile and from 333.5 kBT to 46.1 kBT for anatase, respectively, which further validated the remarkable influence of UV irradiation on the aggregation kinetics of rutile and anatase submicron particles. This work presents a further understanding of the aggregation mechanism of light-controlled submicron particles and has a promising potential application in environmental remediation.

  1. Submicron particle chemistry: Vapor condensation analogous to liquid solidification

    Science.gov (United States)

    Jenkins, Neil T.; Eagar, Thomas W.

    2003-06-01

    The chemical composition of submicron particles condensed from vapor can vary with particle size. This chemical variation with size affects industrial health estimates and technological innovation. A model based on similar behavior during the solidification of liquids is proposed to explain this behavior.

  2. Deep-submicron CMOS Single Photon Detectors and Quantum Effects

    NARCIS (Netherlands)

    Karami, M.A.

    2011-01-01

    Quantum parasitic effects and miniaturization of Single Photon Avalanche Diodes in deep-submicron technologies have been studied in this thesis in detail. Tunneling noise and Random Telegraph Signal (RTS) noise have been the main two parasitic effects addressed comprehensively. While the fundamental

  3. Laser smoothing of sub-micron grooves in hydroxyl-rich fused silica

    Energy Technology Data Exchange (ETDEWEB)

    Shen Nan [Lawrence Livermore National Laboratory, 7000 East Avenue, L-491, Livermore, CA 94550-9234 (United States); Matthews, Manyalibo J., E-mail: ibo@llnl.gov [Lawrence Livermore National Laboratory, 7000 East Avenue, L-491, Livermore, CA 94550-9234 (United States); Fair, James E.; Britten, Jerald A.; Nguyen, Hoang T.; Cooke, Diane; Elhadj, Selim; Yang, Steven T. [Lawrence Livermore National Laboratory, 7000 East Avenue, L-491, Livermore, CA 94550-9234 (United States)

    2010-04-01

    Nano- to micrometer-sized surface defects on UV-grade fused silica surfaces are known to be effectively smoothed through the use of high-temperature localized CO{sub 2} laser heating, thereby enhancing optical properties. However, the details of the mass transport and the effect of hydroxyl content on the laser smoothing of defective silica at sub-micron length scales are still not completely understood. In this study, we examine the morphological evolution of sub-micron, dry-etched periodic surface structures on type II and type III SiO{sub 2} substrates under 10.6 {mu}m CO{sub 2} laser irradiation using atomic force microscopy (AFM). In situ thermal imaging was used to map the transient temperature field across the heated region, allowing assessment of the T-dependent mass transport mechanisms under different laser-heating conditions. Computational fluid dynamics simulations correlated well with experimental results, and showed that for large effective capillary numbers (N{sub c} > 2), surface diffusion is negligible and smoothing is dictated by capillary action, despite the relatively small spatial scales studied here. Extracted viscosity values over 1700-2000 K were higher than the predicted bulk values, but were consistent with the surface depletion of OH groups, which was confirmed using confocal Raman microscopy.

  4. Laser smoothing of sub-micron grooves in hydroxyl-rich fused silica

    Energy Technology Data Exchange (ETDEWEB)

    Shen, N; Matthews, M J; Fair, J E; Britten, J A; Nguyen, H T; Cooke, D; Elhadj, S; Yang, S T

    2009-10-30

    Nano- to micrometer-sized surface defects on UV-grade fused silica surfaces are known to be effectively smoothed through the use of high-temperature localized CO{sub 2} laser heating, thereby enhancing optical properties. However, the details of the mass transport and the effect of hydroxyl content on the laser smoothing of defective silica at submicron length scales is still not completely understood. In this study, we examine the morphological evolution of sub-micron, dry-etched periodic surface structures on type II and type III SiO{sub 2} substrates under 10.6 {micro}m CO{sub 2} laser irradiation using atomic force microscopy (AFM). In-situ thermal imaging was used to map the transient temperature field across the heated region, allowing assessment of the T-dependent mass transport mechanisms under different laser-heating conditions. Computational fluid dynamics simulations correlated well with experimental results, and showed that for large effective capillary numbers (N{sub c} > 2), surface diffusion is negligible and smoothing is dictated by capillary action, despite the relatively small spatial scales studied here. Extracted viscosity values over 1700-2000K were higher than the predicted bulk values, but were consistent with the surface depletion of OH groups, which was confirmed using confocal Raman microscopy.

  5. Sub-micron Cu/SSZ-13: Synthesis and application as selective catalytic reduction (SCR) catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Prodinger, Sebastian; Derewinski, Miroslaw A.; Wang, Yilin; Washton, Nancy M.; Walter, Eric D.; Szanyi, János; Gao, Feng; Wang, Yong; Peden, Charles H. F.

    2017-02-01

    For the first time, sub-micron Cu/SSZ-13, obtained by modifying an existing synthesis procedure, was shown to be an effective and stable catalyst for selective catalytic reduction reactions, such as NO reduction. Characterization of the materials with X-ray diffraction, N2-physisorption and 27Al MAS NMR shows that hydrothermal aging, simulating SCR reaction conditions, is more destructive in respect to dealumination for smaller particles prior to Cu-exchange. However, the catalytic performance and hydrothermal stability for Cu/SSZ-13 is independent of the particle size. In particular, the stability of tetrahedral framework Al is improved in the sub-micron Cu/SSZ-13 catalysts of comparable Cu loading. This indicates that variations in the Al distribution for different SSZ-13 synthesis procedures have a more critical influence on stabilizing isolated Cu-ions during harsh hydrothermal aging than the particle size. This study is of high interest for applications in vehicular DeNOx technologies where high loadings of active species on wash coats can be achieved by using sub-micron Cu/SSZ-13. The authors would like to thank B. W. Arey and J. J. Ditto for performing electron microscope imaging. The authors gratefully acknowledge the US Department of Energy (DOE), Energy Efficiency and Renewable Energy, Vehicle Technologies Office for the support of this work. S. P and M. A. D also acknowledge support by the Materials Synthesis and Simulation Across Scales (MS3 Initiative) conducted under the Laboratory Directed Research & Development Program at PNNL. The research described in this paper was performed in the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle.

  6. Submicron/nano-structured icephobic surfaces made from fluorinated polymethylsiloxane and octavinyl-POSS

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yancai; Luo, Chenghao; Li, Xiaohui; Zhang, Kaiqiang; Zhao, Yunhui; Zhu, Kongying; Yuan, Xiaoyan, E-mail: yuanxy@tju.edu.cn

    2016-01-01

    Graphical abstract: The submicron/nano-structured morphology induced by OVPOSS has a strong effect on ice attachment. The OVPOSS particles aggregated on the top surface could decrease the ice adhesion strength. - Highlights: • Fluorinated hybrid films were fabricated from PMHS–xFMA and OVPOSS. • The hybrid films presented icephobic surfaces in submicron/nano-structure. • PMHS–17FMA could enhance hydrophobicity rather than icephobic properties. • Proper OVPOSS content (10–15 wt%) favored reducing the ice adhesion strength. • Rougher surface morphology (R{sub q} > 90 nm) was benefit for repelling water droplets. - Abstract: Fluorinated hybrid films composed of fluorinated polymethylsiloxane (PMHS–xFMA, x = 6, 13, 17) and octavinyl-polyhedral oligomeric silsesquioxanes (OVPOSS) were prepared for icephobic applications. PMHS–xFMA with diverse fluorinated side groups were synthesized via hydrosilylation of polymethylhydrosiloxane (PMHS) with fluorinated methacrylate (xFMA), i.e., hexafluorobutyl methacrylate (6FMA), tridecafluorooctyl methacrylate (13FMA) and heptadecafluorodecyl methacrylate (17FMA), respectively. Characterizations of atomic force microscope and scanning electron microscope indicated that surfaces of the hybrid films consisted of submicron/nano-scaled OVPOSS aggregates, and the root-mean-square roughness (S{sub q}) could vary from 42.6 nm to 145.2 nm with various OVPOSS content (5–20 wt%). Wettability measurements of the prepared films demonstrated that the relatively longer fluorinated side groups in PMHS–17FMA were beneficial for decreasing surface energy and enhancing hydrophobic properties. However, the fluorinated hybrid films with PMHS–17FMA presented higher ice shear strengths due to the stronger interfacial interactions between the film surface and ice/water. The film prepared by PMHS–13FMA and 10 wt% of OVPOSS with proper roughness (90.2 nm) performed the lowest ice shear strength (188.2 ± 13.4 kPa) among all the

  7. Surfactant-assisted solvothermal synthesis of pure nickel submicron spheres with microwave-absorbing properties

    Science.gov (United States)

    Guo, Heng; Pu, Bingxue; Chen, Haiyuan; Yang, Jin; Zhou, Yajun; Yang, Jian; Bismark, Boateng; Li, Handong; Niu, Xiaobin

    2016-07-01

    Pure metallic nickel submicron spheres (Ni-SSs), flower-like nickel nanoflakes, and hollow micrometer-sized nickel spheres/tubes were controllably synthesized by a facile and efficient one-step solvothermal method with no reducing agent. The characteristics of these nickel nanostructures include morphology, structure, and purification. Possible synthesis mechanisms were discussed in detail. The resultant Ni-SSs had a wide diameter distribution of 200~800 nm through the aggregation of small nickel nanocrystals. The ferromagnetic behaviors of Ni-SSs investigated at room temperature showed high coercivity values. Furthermore, the microwave absorption properties of magnetic Ni-SSs were studied in the frequency range of 0.5-18.0 GHz. The minimum reflection loss reached -17.9 dB at 17.8 GHz with a thin absorption thickness of 1.2 mm, suggesting that the submicron spherical structures could exhibit excellent microwave absorption properties. More importantly, this one-pot synthesize route provides a universal and convenient way for preparation of larger scale pure Ni-SSs, showing excellent microwave absorption properties.

  8. Stochastic process variation in deep-submicron CMOS circuits and algorithms

    CERN Document Server

    Zjajo, Amir

    2014-01-01

    One of the most notable features of nanometer scale CMOS technology is the increasing magnitude of variability of the key device parameters affecting performance of integrated circuits. The growth of variability can be attributed to multiple factors, including the difficulty of manufacturing control, the emergence of new systematic variation-generating mechanisms, and most importantly, the increase in atomic-scale randomness, where device operation must be described as a stochastic process. In addition to wide-sense stationary stochastic device variability and temperature variation, existence of non-stationary stochastic electrical noise associated with fundamental processes in integrated-circuit devices represents an elementary limit on the performance of electronic circuits. In an attempt to address these issues, Stochastic Process Variation in Deep-Submicron CMOS: Circuits and Algorithms offers unique combination of mathematical treatment of random process variation, electrical noise and temperature and ne...

  9. Single Mode ZnO Whispering-Gallery Submicron Cavity and Graphene Improved Lasing Performance.

    Science.gov (United States)

    Li, Jitao; Lin, Yi; Lu, Junfeng; Xu, Chunxiang; Wang, Yueyue; Shi, Zengliang; Dai, Jun

    2015-07-28

    Single-mode ultraviolet (UV) laser of ZnO is still in challenge so far, although it has been paid great attention along the past decades. In this work, single-mode lasing resonance was realized in a submicron-sized ZnO rod based on serially varying the dimension of the whispering-gallery mode (WGM) cavities. The lasing performance, such as the lasing quality factor (Q) and the lasing intensity, was remarkably improved by facilely covering monolayer graphene on the ZnO submicron-rod. The mode structure evolution from multimodes to single-mode was investigated systematically based on the total internal-wall reflection of the ZnO microcavities. Graphene-induced optical field confinement and lasing emission enhancement were revealed, indicating an energy coupling between graphene SP and ZnO exciton emission. This result demonstrated the response of graphene in the UV wavelength region and extended its potential applications besides many previous reports on the multifunctional graphene/semiconductor hybrid materials and devices in advanced electronics and optoelectronics areas.

  10. Changes of propagation light in optical fiber submicron wires

    Science.gov (United States)

    Stasiewicz, K. A.; Łukowski, A.; Jaroszewicz, L. R.

    2013-05-01

    At the moment technology allows to miniaturize measurement system to several micrometers. Application of an optical fiber taper in such system needs to manufacture a new one with diameters below single micrometers which is very difficult and expensive. Another way to obtain this level of diameters is the process of tapering from the existing fibers. In the paper, experimental results of propagation light from a supercontinnum sources of the wavelength generates the wavelength of 350-2000 nm, in different optical fiber submicron wires made from tapers manufactured from single mode fibers are presented. Biconical optical fibers' tapers were manufactured in low pressure gas burner technique. There are presented spectral characteristics of a propagated beam. For the test, there was manufactured an optical fiber submicron wires with a different length of waist region with a diameter near one micrometer. We put to the test a taper made from a standard telecommunication fiber SMF-28 with a cutoff wavelength equal to 1260.

  11. Submicron bioactive glass tubes for bone tissue engineering.

    Science.gov (United States)

    Xie, Jingwei; Blough, Eric R; Wang, Chi-Hwa

    2012-02-01

    Herein we describe a method to fabricate submicron bioactive glass tubes using sol-gel and coaxial electrospinning techniques for applications in bone tissue engineering. Heavy mineral oil and gel solution were delivered by two independent syringe pumps during the coaxial electrospinning process. Subsequently, submicron bioactive glass tubes were obtained by removal of poly(vinyl pyrrolidone) and heavy mineral oil via calcination at 600 °C for 5 h. Tubular structure was confirmed by scanning electron microscopy and transmission electron microscopy imaging. We examined the bioactivity of submicron bioactive glass tubes and fibers and evaluated their biocompatibility, using electrospun poly(ε-caprolactone) fibers--a bioinactive material--for comparison. The bioactivity of the glass tubes was examined in a simulated body fluid and they demonstrated the formation of hydroxyapatite-like minerals on both the outer and inner surfaces. In contrast, mineralization only occurred on their surface for bioactive glass solid fibers. Energy-dispersive X-ray data suggested that the bioactive glass tubes had a faster induction of mineral formation than the solid fibers. We demonstrate that the proliferation rate of mouse preosteoblastic MC3T3-E1 cells on bioactive glass tubes was comparable to that on solid fibers. We also show that bioactive glass tubes can be loaded with a model protein drug, bovine serum albumin, and that these structures exhibit delayed release properties. The bioactivity of released lysozyme can be as high as 90.9%. Taken together, these data suggest that submicron bioactive glass tubes could hold great potential for use in bone tissue engineering as well as topical drug or gene delivery. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  12. Energy Efficient Signaling in Deep-submicron Technology

    Directory of Open Access Journals (Sweden)

    Imed Ben Dhaou

    2002-01-01

    Full Text Available In deep-submicron technology, global interconnect capacitances have started reaching several orders of magnitude greater than the intrinsic capacitances of the CMOS gates. The dynamic power consumption of a CMOS gate driving a global wire is the sum of the power dissipated due to (discharging (i the intrinsic capacitance of the gate, and (ii the wire capacitance. The latter is referred to as on-chip signaling power consumption.

  13. Submicron plasticity: yield stress, dislocation avalanches, and velocity distribution

    OpenAIRE

    Ispánovity, Péter Dusán; Groma, István; Györgyi, Géza; Csikor, Ferenc F.; Weygand, Daniel

    2010-01-01

    The existence of a well defined yield stress, where a macroscopic piece of crystal begins to plastically flow, has been one of the basic observations of materials science. In contrast to macroscopic samples, in micro- and nanocrystals the strain accumulates in distinct, unpredictable bursts, which makes controlled plastic forming rather difficult. Here we study by simulation, in two and three dimensions, plastic deformation of submicron objects under increasing stress. We show that, while the...

  14. Submicron Resolution Spectral-Domain Optical Coherence Tomography

    KAUST Repository

    Alarousu, Erkki

    2013-11-14

    Apparatuses and systems for submicron resolution spectral-domain optical coherence tomography (OCT) are disclosed. The system may use white light sources having wavelengths within 400-1000 nanometers, and achieve resolution below 1 .mu.m. The apparatus is aggregated into a unitary piece, and a user can connect the apparatus to a user provided controller and/or light source. The light source may be a supercontinuum source.

  15. Pressing induced polymorphic phase transition in submicron-sized gamma-HMX

    Science.gov (United States)

    Moore, David; Lee, Kien-Yin

    2007-06-01

    Submicron HMX has been produced and characterized to be less sensitive than impact standard HMX in small-scale sensitivity tests. The sm-HMX was found to be the gamma polymorph and to be stable under ambient conditions for at least a year. Pressing of sm-HMX in a small diameter pellet press at pressures from 10 000 psi to 31 000 psi and 1 to 5 minute hold times was found to promote the gamma to beta polymorphic phase transition. The fraction converted and rate of conversion versus time after pellet removal from the press were found to fit a sigmoidal curve, indicating nucleation and growth as a possible polymorphic transition mechanism.

  16. Effect of Microstructure Scale on Negative Thermal Expansion of Antiperovskite Manganese Nitride

    National Research Council Canada - National Science Library

    Zhonghua Sun Xiaoyan Song

    The negative thermal expansion (NTE) properties of the antiperovskite manganese nitrides with micron-scale, submicron-scale and nanometer-scale microstructures, respectively, were investigated using...

  17. Neurotoxicity of low-dose repeatedly intranasal instillation of nano- and submicron-sized ferric oxide particles in mice

    Energy Technology Data Exchange (ETDEWEB)

    Wang Bing; Feng Weiyue, E-mail: fengwy@mail.ihep.ac.cn; Zhu Motao; Wang Yun; Wang Meng [Chinese Academy of Sciences, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics (China); Gu Yiqun [Maternity Hospital of Haidian District (China); Ouyang Hong; Wang Huajian; Li Ming; Zhao Yuliang, E-mail: zhaoyuliang@mail.ihep.ac.cn; Chai Zhifang [Chinese Academy of Sciences, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics (China); Wang Haifang [Peking University, College of Chemistry and Molecular Engineering (China)

    2009-01-15

    Olfactory tract has been demonstrated to be an important portal for inhaled solid nanoparticle transportation into the central nervous system (CNS). We have previously demonstrated that intranasally instilled Fe{sub 2}O{sub 3} nanoparticles could transport into the CNS via olfactory pathway. In this study, we investigated the neurotoxicity and size effect of repeatedly low-dose (130 {mu}g) intranasal exposure of nano- and submicron-sized Fe{sub 2}O{sub 3} particles (21 nm and 280 nm) to mice. The biomarkers of oxidative stress, activity of nitric oxide synthases and release of monoamine neurotransmitter in the brain were studied. Our results showed that significant oxidative stress was induced by the two sizes of Fe{sub 2}O{sub 3} particles. The activities of GSH-Px, Cu,Zn-SOD, and cNOS significantly elevated and the total GSH and GSH/GSSG ratio significantly decreased in the olfactory bulb and hippocampus after the nano- and submicron-sized Fe{sub 2}O{sub 3} particle treatment (p < 0.05). The nano-sized Fe{sub 2}O{sub 3} generally induced greater alteration and more significant dose-effect response than the submicron-sized particle did. Some slight perturbation of monoamine neurotransmitters were found in the hippocampus after exposure to the two sizes of Fe{sub 2}O{sub 3} particle. The TEM image showed that some ultrastructural alterations in nerve cells, including neurodendron degeneration, membranous structure disruption and lysosome increase in the olfactory bulb, slight dilation in the rough endoplasmic reticulum and lysosome increase in the hippocampus were induced by the nano-sized Fe{sub 2}O{sub 3} treatment. In contrast, in the submicron-sized Fe{sub 2}O{sub 3} treated mice, slightly swollen mitochondria and some vacuoles were observed in the olfactory bulb and hippocampus, respectively. These results indicate that intranasal exposure of Fe{sub 2}O{sub 3} nanoparticles could induce more severe oxidative stress and nerve cell damage in the brain than the

  18. Interaction between submicron COD crystals and renal epithelial cells.

    Science.gov (United States)

    Peng, Hua; Ouyang, Jian-Ming; Yao, Xiu-Qiong; Yang, Ru-E

    2012-01-01

    This study aims to investigate the adhesion characteristics between submicron calcium oxalate dihydrate (COD) with a size of 150 ± 50 nm and African green monkey kidney epithelial cells (Vero cells) before and after damage, and to discuss the mechanism of kidney stone formation. Vero cells were oxidatively injured by hydrogen peroxide to establish a model of injured cells. Scanning electron microscopy was used to observe Vero-COD adhesion. Inductively coupled plasma emission spectrometry was used to quantitatively measure the amount of adhered COD microcrystals. Nanoparticle size analyzer and laser scanning confocal microscopy were performed to measure the change in the zeta potential on the Vero cell surface and the change in osteopontin expression during the adhesion process, respectively. The level of cell injury was evaluated by measuring the changes in malonaldehyde content, and cell viability during the adhesion process. The adhesion capacity of Vero cells in the injury group to COD microcrystals was obviously stronger than that of Vero cells in the control group. After adhesion to COD, cell viability dropped, both malonaldehyde content and cell surface zeta potential increased, and the fluorescence intensity of osteopontin decreased because the osteopontin molecules were successfully covered by COD. Submicron COD further damaged the cells during the adhesion process, especially for Vero cells in the control group, leading to an elevated amount of attached microcrystals. Submicron COD can further damage injured Vero cells during the adhesion process. The amount of attached microcrystals is proportional to the degree of cell damage. The increased amount of microcrystals that adhered to the injured epithelial cells plays an important role in the formation of early-stage kidney stones.

  19. Highly sensitive measurement of submicron waveguides based on Brillouin scattering

    Science.gov (United States)

    Godet, Adrien; Ndao, Abdoulaye; Sylvestre, Thibaut; Beugnot, Jean-Charles; Phan Huy, Kien

    2017-02-01

    Fabrication and characterization of submicron optical waveguides is one of the major challenges in modern photonics, as they find many applications from optical sensors to plasmonic devices. Here we report on a novel technique that allows for a complete and precise characterization of silica optical nanofibers. Our method relies on the Brillouin backscattering spectrum analysis that directly depends on the waveguide geometry. Our method was applied to several fiber tapers with diameter ranging from 500 nm to 3 μm. Results were compared to scanning electron microscopy (SEM) images and numerical simulations with very good agreement and similar sensitivity.

  20. Electron acceleration via high contrast laser interacting with submicron clusters

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lu; Chen Liming; Wang Weiming; Yan Wenchao; Yuan Dawei; Mao Jingyi; Wang Zhaohua; Liu Cheng; Shen Zhongwei; Li Yutong; Dong Quanli; Lu Xin; Ma Jinglong; Wei Zhiyi [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Faenov, Anatoly; Pikuz, Tatiana [Joint Institute for High Temperature of the Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412 (Russian Federation); Quantum Beams Science Directorate, JAEA, Kizugawa, Kyoto (Japan); Li Dazhang [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Institute of High Energy Physics, CAS, Beijing 100049 (China); Sheng Zhengming [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang Jie [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2012-01-02

    We experimentally investigated electron acceleration from submicron size argon clusters-gas target irradiated by a 100 fs, 10 TW laser pulses having a high-contrast. Electron beams are observed in the longitudinal and transverse directions to the laser propagation. The measured energy of the longitudinal electron reaches 600 MeV and the charge of the electron beam in the transverse direction is more than 3 nC. A two-dimensional particle-in-cell simulation of the interaction has been performed and it shows an enhancement of electron charge by using the cluster-gas target.

  1. Submicron particle monitoring of paving and related road construction operations.

    Science.gov (United States)

    Freund, Alice; Zuckerman, Norman; Baum, Lisa; Milek, Debra

    2012-01-01

    This study identified activities and sources that contribute to ultrafine and other submicron particle exposure that could trigger respiratory symptoms in highway repair workers. Submicron particle monitoring was conducted for paving, milling, and pothole repair operations in a major metropolitan area where several highway repair workers were identified as symptomatic for respiratory illness following exposures at the 2001 World Trade Center disaster site. Exposure assessments were conducted for eight trades involved in road construction using a TSI P-Trak portable condensation particle counter. Direct readings near the workers' breathing zones and observations of activities and potential sources were logged on 7 days on 27 workers using four different models of pavers and two types of millers. Average worker exposure levels ranged from 2 to 3 times background during paving and from 1 to 4 times background during milling. During asphalt paving, average personal exposures to submicron particulates were 25,000-60,000, 28,000-70,000, and 23,000-37,000 particles/ cm(3) for paver operators, screed operators, and rakers, respectively. Average personal exposures during milling were 19,000-111,000, 28,000-81,000, and 19,000 particles/cm(3) for the large miller operators, miller screed operators, and raker, respectively. Personal peak exposures were measured up to 467,000 and 455,000 particles/cm(3) in paving and milling, respectively. Several sources of submicron particles were identified. These included the diesel and electric fired screed heaters; engine exhaust from diesel powered construction vehicles passing by or idling; raking, dumping, and paving of asphalt; exhaust from the hotbox heater; pavement dust or fumes from milling operations, especially when the large miller started and stopped; and secondhand cigarette smoke. To reduce the potential for health effects in workers, over 40 recommendations were made to control exposures, including improved maintenance of

  2. Novel Translucent and Strong Submicron Alumina Ceramics for Dental Restorations.

    Science.gov (United States)

    Zhao, M; Sun, Y; Zhang, J; Zhang, Y

    2017-10-01

    An ideal ceramic restorative material should possess excellent aesthetic and mechanical properties. We hypothesize that the high translucency and strength of polycrystalline ceramics can be achieved through microstructural tailoring. The aim of this study is to demonstrate the superior optical and mechanical properties of a new class of submicron grain-sized alumina ceramics relative to the current state-of-the-art dental ceramic materials. The translucency, the in-line transmission ( TIT) in particular, of these submicron alumina ceramics has been examined with the Rayleigh-Gans-Debye light-scattering model. The theoretical predictions related very well with the measured TIT values. The translucency parameter ( TP) and contrast ratio ( CR) of the newly developed aluminas were measured with a reflectance spectrophotometer on a black-and-white background. For comparison, the TIT, TP, and CR values for a variety of dental ceramics, mostly measured in-house but also cited from the literature, were included. The flexural strength of the aluminas was determined with the 4-point bending test. Our findings have shown that for polycrystalline alumina ceramics, an average grain size <1 µm coupled with a porosity level <0.7% could yield translucency values ( TIT, TP, CR) similar to those of the commercial high-translucency porcelains. These values are far superior to the high-translucency lithium disilicate glass-ceramic and zirconias, including the most translucent cubic-containing zirconias. The strength of these submicron grain-sized aluminas was significantly higher than that of the cubic-containing zirconia (e.g., Zpex Smile) and lithia-based glass-ceramics (e.g., IPS e.max CAD HT). A coarse-grained alumina could also reach a translucency level comparable to that of dental porcelain. However, the relatively low strength of this material has limited its clinical indications to structurally less demanding applications, such as orthodontic brackets. With a combined high

  3. Online submicron particle sizing by dynamic light scattering using autodilution

    Science.gov (United States)

    Nicoli, David F.; Elings, V. B.

    1989-01-01

    Efficient production of a wide range of commercial products based on submicron colloidal dispersions would benefit from instrumentation for online particle sizing, permitting real time monitoring and control of the particle size distribution. Recent advances in the technology of dynamic light scattering (DLS), especially improvements in algorithms for inversion of the intensity autocorrelation function, have made it ideally suited to the measurement of simple particle size distributions in the difficult submicron region. Crucial to the success of an online DSL based instrument is a simple mechanism for automatically sampling and diluting the starting concentrated sample suspension, yielding a final concentration which is optimal for the light scattering measurement. A proprietary method and apparatus was developed for performing this function, designed to be used with a DLS based particle sizing instrument. A PC/AT computer is used as a smart controller for the valves in the sampler diluter, as well as an input-output communicator, video display and data storage device. Quantitative results are presented for a latex suspension and an oil-in-water emulsion.

  4. Submicron magnetic core conducting polypyrrole polymer shell: Preparation and characterization.

    Science.gov (United States)

    Tenório-Neto, Ernandes Taveira; Baraket, Abdoullatif; Kabbaj, Dounia; Zine, Nadia; Errachid, Abdelhamid; Fessi, Hatem; Kunita, Marcos Hiroiuqui; Elaissari, Abdelhamid

    2016-04-01

    Magnetic particles are of great interest in various biomedical applications, such as, sample preparation, in vitro biomedical diagnosis, and both in vivo diagnosis and therapy. For in vitro applications and especially in labs-on-a-chip, microfluidics, microsystems, or biosensors, the needed magnetic dispersion should answer various criteria, for instance, submicron size in order to avoid a rapid sedimentation rate, fast separations under an applied magnetic field, and appreciable colloidal stability (stable dispersion under shearing process). Then, the aim of this work was to prepare highly magnetic particles with a magnetic core and conducting polymer shell particles in order to be used not only as a carrier, but also for the in vitro detection step. The prepared magnetic seed dispersions were functionalized using pyrrole and pyrrole-2-carboxylic acid. The obtained core-shell particles were characterized in terms of particle size, size distribution, magnetization properties, FTIR analysis, surface morphology, chemical composition, and finally, the conducting property of those particles were evaluated by cyclic voltammetry. The obtained functional submicron highly magnetic particles are found to be conducting material bearing function carboxylic group on the surface. These promising conducting magnetic particles can be used for both transport and lab-on-a-chip detection. Copyright © 2015. Published by Elsevier B.V.

  5. Separating the signal from the noise: Expanding flow cytometry into the sub-micron range.

    Science.gov (United States)

    Cytometry Part A Special Section: Separating the signal from the noise: Expanding flow cytometry into the sub-micron range. The current Cytometry Part A Special Section presents three studies that utilize cytometers to study sub-micron particles. The three studies involve the 1...

  6. Magnetic trapping of superconducting submicron particles produced by laser ablation in superfluid helium

    Science.gov (United States)

    Takahashi, Yuta; Suzuki, Junpei; Yoneyama, Naoya; Tokawa, Yurina; Suzuki, Nobuaki; Matsushima, Fusakazu; Kumakura, Mitsutaka; Ashida, Masaaki; Moriwaki, Yoshiki

    2017-02-01

    We produced spherical superconducting submicron particles by laser ablation of their base metal tips in superfluid helium, and trapped them using a quadrupole magnetic field owing to the diamagnetism caused by the Meissner effect. We also measured their critical temperatures of superconductivity, by observing the threshold temperatures for the confinement of superconducting submicron particles in the trap.

  7. Submicron-resolution photoacoustic microscopy of endogenous light-absorbing biomolecules

    Science.gov (United States)

    Zhang, Chi

    Photoacoustic imaging in biomedicine has the unique advantage of probing endogenous light absorbers at various length scales with a 100% relative sensitivity. Among the several modalities of photoacoustic imaging, optical-resolution photoacoustic microscopy (OR-PAM) can achieve high spatial resolution, on the order of optical wavelength, at targets fluorescent markers, label-free PAM avoids the major concerns that the fluorescent labeling probes may disturb the function of biomolecules and may have an insufficient density. This dissertation aims to advance label-free OR-PAM to the subcellular scale. The first part of this dissertation describes the technological advancement of PAM yielding high spatial resolution in 3D. The lateral resolution was improved by using optical objectives with high numerical apertures for optical focusing. The axial resolution was improved by using broadband ultrasonic transducers for ultrasound detection. We achieved 220 nm lateral resolution in transmission mode, 0.43 microm lateral resolution in reflection mode, 7.6 microm axial resolution in normal tissue, and 5.8 microm axial resolution with silicone oil immersion/injection. The achieved lateral resolution and axial resolution were the finest reported at the time. With high-resolution in 3D, PAM was demonstrated to resolve cellular and subcellular structures in vivo, such as red blood cells and melanosomes in melanoma cells. Compared with previous PAM systems, our high-resolution PAM could resolve capillaries in mouse ears more clearly. As an example application, we demonstrated intracellular temperature imaging, assisted by fluorescence signal detection, with sub-degree temperature resolution and sub-micron lateral resolution. The second part of this dissertation describes the exploration of endogenous light-absorbing biomolecules for PAM. We demonstrated cytochromes and myoglobin as new absorption contrasts for PAM and identified the corresponding optimal wavelengths for imaging

  8. Discovering sub-micron ice particles across Dione' surface

    Science.gov (United States)

    Scipioni, Francesca; Schenk, Pual; Tosi, Federico; Clark, Roger; Dalle Ore, Cristina; Combe, Jean-Philippe

    2015-11-01

    Water ice is the most abundant component of Saturn’s mid-sized moons. However, these moons show an albedo asymmetry - their leading sides are bright while their trailing side exhibits dark terrains. Such differences arise from two surface alteration processes: (i) the bombardment of charged particles from the interplanetary medium and driven by Saturn’s magnetosphere on the trailing side, and (ii) the impact of E-ring water ice particles on the satellites’ leading side. As a result, the trailing hemisphere appears to be darker than the leading side. This effect is particularly evident on Dione's surface. A consequence of these surface alteration processes is the formation or the implantation of sub-micron sized ice particles.The presence of such particles influences and modifies the surfaces' spectrum because of Rayleigh scattering by the particles. In the near infrared range of the spectrum, the main sub-micron ice grains spectral indicators are: (i) asymmetry and (ii) long ward minimum shift of the absorption band at 2.02 μm (iii) a decrease in the ratio between the band depths at 1.50 and 2.02 μm (iv) a decrease in the height of the spectral peak at 2.6 μm (v) the suppression of the Fresnel reflection peak at 3.1 μm and (vi) the decrease of the reflection peak at 5 μm relative to those at 3.6 μm.We present results from our ongoing work mapping the variation of sub-micron ice grains spectral indicators across Dione' surface using Cassini-VIMS cubes acquired in the IR range (0.8-5.1 μm). To characterize the global variations of spectral indicators across Dione' surface, we divided it into a 1°x1° grid and then averaged the band depths and peak values inside each square cell.We will investigate if there exist a correspondence with water ice abundance variations by producing water ice' absorption band depths at 1.25, 1.52 and 2.02 μm, and with surface morphology by comparing the results with ISS color maps in the ultraviolet, visible and infrared

  9. Size effects in piezoelectric cantilevers at submicron thickness levels due to flexoelectricity

    Science.gov (United States)

    Moura, Adriane G.; Erturk, Alper

    2017-04-01

    In elastic dielectrics, piezoelectricity is the response of polarization to applied mechanical strain, and vice versa. Piezoelectric coupling is controlled by a third-rank tensor and is allowed only in materials that are non-centrosymmetric. Flexoelectricity, however, is the generation of electric polarization by the application of a non-uniform mechanical strain field, i.e. a strain gradient, and is expected to be pronounced at submicron thickness levels, especially at the nano-scale. Flexoelectricity is controlled by a fourth-rank tensor and is therefore allowed in materials of any symmetry. As a gradient effect, flexoelectricity is size dependent, while piezoelectric coupling has no size dependence. Any ordinary piezoelectric cantilever model developed for devices above micron-level thickness has to be modified for nano-scale piezoelectric devices since the effect of flexoelectric coupling will change the electroelastic dynamics at such small scales. In this work, we establish and explore a complete analytical framework by accounting for both the piezoelectric and flexoelectric effects. The focus is placed on the development of governing electroelastodynamic piezoelectric-flexoelectric equations for the problems of energy harvesting, sensing, and actuation. The coupled governing equations are analyzed to obtain the frequency response. The coupling coefficient for the bimorph configuration is identified and its size dependence is explored.

  10. Short range investigation of sub-micron zirconia particles

    Energy Technology Data Exchange (ETDEWEB)

    Caracoche, M C; Martinez, J A [Departamento de Fisica, IFLP, Facultad de Ciencias Exactas, CICPBA, Universidad Nacional de La Plata (Argentina); Rivas, P C [IFLP-CONICET, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata (Argentina); Bondioli, F; Cannillo, V [Dipartimento di Ingegniria dei Materiali e dell' Ambiente, Facolta di Ingegneria, Universita di Modena e Reggio Emilia (Italy); Ferrari, A M, E-mail: cristina@fisica.unlp.edu.a [Dipartimento di Scienza a Metodi dell' Ingegneria, Universita di Modena e Reggio Emilia (Italy)

    2009-05-01

    The Perturbed Angular Correlations technique was used to determine the configurations around Zirconium ions and their thermal behavior in non-aggregated sub-micron zirconia spherical particles. Three residues containing- Zr surroundings were determined for the non-crystalline starting particles, which were identified under the assumption of a certain chemical reactions sequence during synthesis. While the one made up mainly by hydroxyl groups was common to both samples, the two involving mainly organic residues were particle size dependent. Upon crystallization, both samples stabilized in the t'- and t- tetragonal forms and the Xc-cubic form but their amounts and temperatures of appearance were different. On heating, the structure of the smaller particles became gradually monoclinic achieving total degradation upon the subsequent cooling to RT.

  11. Chemical strategies for die/wafer submicron alignment and bonding.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, James Ellis; Baca, Alicia I.; Chu, Dahwey; Rohwer, Lauren Elizabeth Shea

    2010-09-01

    This late-start LDRD explores chemical strategies that will enable sub-micron alignment accuracy of dies and wafers by exploiting the interfacial energies of chemical ligands. We have micropatterned commensurate features, such as 2-d arrays of micron-sized gold lines on the die to be bonded. Each gold line is functionalized with alkanethiol ligands before the die are brought into contact. The ligand interfacial energy is minimized when the lines on the die are brought into registration, due to favorable interactions between the complementary ligand tails. After registration is achieved, standard bonding techniques are used to create precision permanent bonds. We have computed the alignment forces and torque between two surfaces patterned with arrays of lines or square pads to illustrate how best to maximize the tendency to align. We also discuss complex, aperiodic patterns such as rectilinear pad assemblies, concentric circles, and spirals that point the way towards extremely precise alignment.

  12. Submicron Plasticity: Yield Stress, Dislocation Avalanches, and Velocity Distribution

    Science.gov (United States)

    Ispánovity, Péter Dusán; Groma, István; Györgyi, Géza; Csikor, Ferenc F.; Weygand, Daniel

    2010-08-01

    The existence of a well-defined yield stress, where a macroscopic crystal begins to plastically flow, has been a basic observation in materials science. In contrast with macroscopic samples, in microcrystals the strain accumulates in random bursts, which makes controlled plastic formation difficult. Here we study by 2D and 3D simulations the plastic deformation of submicron objects under increasing stress. We show that, while the stress-strain relation of individual samples exhibits jumps, its average and mean deviation still specify a well-defined critical stress. The statistical background of this phenomenon is analyzed through the velocity distribution of dislocations, revealing a universal cubic decay and the appearance of a shoulder due to dislocation avalanches.

  13. Microscopic methods in analysis of submicron phospholipid dispersions

    Directory of Open Access Journals (Sweden)

    Płaczek Marcin

    2016-03-01

    Full Text Available Microscopy belongs to the group of tests, used in pharmaceutical technology, that despite the lapse of time and the development of new analytical methods, still remain irreplaceable for the characterization of dispersed drug dosage forms (e.g., suspensions and emulsions. To obtain complete description of a specific drug formulation, such as parenteral colloidal products, a combination of different microscopic techniques is sometimes required. Electron microscopy methods are the most useful ones; however, even such basic methods as optical microscopy may be helpful for determination of some properties of a sample. The publication explicates the most popular microscopical techniques used nowadays for characterization of the morphology of nanoparticles suspended in pharmaceutical formulations; ad vantages and disadvantages of these methods are also discussed. Parenteral submicron formulations containing lecithin or a particular phospholipid were chosen as examples.

  14. Large area sub-micron chemical imaging of magnesium in sea urchin teeth.

    Science.gov (United States)

    Masic, Admir; Weaver, James C

    2015-03-01

    The heterogeneous and site-specific incorporation of inorganic ions can profoundly influence the local mechanical properties of damage tolerant biological composites. Using the sea urchin tooth as a research model, we describe a multi-technique approach to spatially map the distribution of magnesium in this complex multiphase system. Through the combined use of 16-bit backscattered scanning electron microscopy, multi-channel energy dispersive spectroscopy elemental mapping, and diffraction-limited confocal Raman spectroscopy, we demonstrate a new set of high throughput, multi-spectral, high resolution methods for the large scale characterization of mineralized biological materials. In addition, instrument hardware and data collection protocols can be modified such that several of these measurements can be performed on irregularly shaped samples with complex surface geometries and without the need for extensive sample preparation. Using these approaches, in conjunction with whole animal micro-computed tomography studies, we have been able to spatially resolve micron and sub-micron structural features across macroscopic length scales on entire urchin tooth cross-sections and correlate these complex morphological features with local variability in elemental composition. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. [Study on preparation of intravenous submicron emulsions of Oleum Cinnamomi oil of Miao nationality herbal].

    Science.gov (United States)

    Li, Jiang; Liu, Ying-bo

    2007-11-01

    To study the prescription and preparation of intravenous submicron emulsion of Oleum Cinnamomi oil of Miao nationality herbal. Using the high speed blender mixed round the Oleum Cinnamomi oil with the soybean phospholipids and Pluronic F68 as emulsifier, then using the high pressure homogenizer made the intravenous submicron emulsion of the Oleum Cinnamomi oil and investigate its grain path and distributing. Having been done by using hydroextractor 4,500 r min(-1) 15 minutes the submicron emulsion grain path has well proportioned distribution. The preparation technology is simple and has good stability, so it can be used as a method to make the intravenous submicron emulsion of the Oleum Cinnamomi oil of Miao nationality herbal.

  16. Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming

    Science.gov (United States)

    Li, Ting [Ventura, CA

    2011-04-26

    The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

  17. Beschrijving van een verdampings-condensatie aerosol generator voor de produktie van submicron aerosol

    NARCIS (Netherlands)

    Feijt; A.*; Meulen; A.van der

    1985-01-01

    Dit rapport is een handleiding voor een bedrijfszeker, routinematig gebruik van een zgn. Evaporation-Condensation aerosol Conditioner. Met deze aerosol generatie apparatuur kunnen op stabiele, reproduceerbare manier zeer hoge concentraties (tot 1 miljoen deeltjes per cc) monodispers submicron

  18. Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming

    Science.gov (United States)

    Li, Ting

    2013-08-13

    The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

  19. Characteristics of Submicron Aerosols in 2013 summer of Beijing

    Science.gov (United States)

    Guo, Song; Hu, Min; Shang, Dongjie; Zheng, Jing; Du, Zhuofei; Wu, Yusheng; Lu, Sihua; Zeng, Limin; Zhang, Renyi

    2016-04-01

    To characterize the air pollution of North China Plain of China, CAREBEIJING-2013 field campaign (Campaigns of Air quality REsearch in BEIJING and surrounding region) was conducted in summer of 2013. Submicron aerosols were measured at an urban site PKU (Peking University, 39° 59'21"N, 116° 18'25"E) from July 28th to September 31st 2013. A suite of integrated instruments was used to measure the size distribution, effective density and hygroscopicity of ambient particles. The chemical composition of submicron particles were measured by using an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) (Billerica, MA, USA). The average PM2.5 concentration was 73.0±70.7 μg m-3 during the measurement. The particulate pollution showed distinct 4-7 days cycles controlled by the meteorological conditions. Each cycle started with low PM2.5 mass concentrations (air mass was from relatively clean mountainous area. The particle number concentrations were high, but and the sizes were small (60 μg day-1, and the particle mean diameter grew to >100 nm. It is interesting to note that the mean diameters showed similar trend to PM2.5 mass concentrations, indicating the particle pollution attributed to the growth of the newly formed small particles. During the measurement, the average particle densities are between 1.3-1.5 g cm-3, indicating organics and sulfate were dominant in the particles. The densities of smaller particles, i.e. 46 nm, 81nm, showed single peak at 1.3-1.5 g cm-3, indicating the particles are internal mixed sulfate and organics. While the 150nm and 240 nm particle densities exhibited bimodal distribution with an additional small peak at ˜1.1 g cm-3, which is considered as external mixed organic particles or aged soot particles. The particle hygroscopic growth factor for all the measured sizes at RH of 90% showed bimodal distribution, attributing to external mixed organics (or aged soot) and internal mixed organics and sulfate. Both the

  20. Rapid heterogeneous oxidation of organic coatings on submicron aerosols

    Science.gov (United States)

    Lim, C. Y.; Browne, E. C.; Sugrue, R. A.; Kroll, J. H.

    2017-03-01

    Laboratory studies have found that heterogeneous oxidation can affect the composition and loading of atmospheric organic aerosol particles over time scales of several days, but most studies have examined pure organic particles only. In this study, in order to probe the reactivity of organic species confined near the particle surface, the rates and products of the OH-initiated oxidation of pure squalane particles are compared to oxidation of thin coatings of squalane on ammonium sulfate particles. The squalane reaction rate constant shows a linear dependence on the organic surface area-to-volume ratio, with rate constants for coated particles up to 10 times larger than for pure particles. Changes in the carbon oxidation state and fraction of particulate carbon remaining show similar enhancements, implying that heterogeneous oxidation may exhibit a stronger effect on the loadings and properties of organic aerosol than previously estimated from laboratory studies.

  1. Controlled motion of domain walls in submicron amorphous wires

    Directory of Open Access Journals (Sweden)

    Mihai Ţibu

    2016-05-01

    Full Text Available Results on the control of the domain wall displacement in cylindrical Fe77.5Si7.5B15 amorphous glass-coated submicron wires prepared by rapid quenching from the melt are reported. The control methods have relied on conical notches with various depths, up to a few tens of nm, made in the glass coating and in the metallic nucleus using a focused ion beam (FIB system, and on the use of small nucleation coils at one of the sample ends in order to apply magnetic field pulses aimed to enhance the nucleation of reverse domains. The notch-based method is used for the first time in the case of cylindrical ultrathin wires. The results show that the most efficient technique of controlling the domain wall motion in this type of samples is the simultaneous use of notches and nucleation coils. Their effect depends on wire diameter, notch depth, its position on the wire length, and characteristics of the applied pulse.

  2. Controlled motion of domain walls in submicron amorphous wires

    Energy Technology Data Exchange (ETDEWEB)

    Ţibu, Mihai; Lostun, Mihaela; Rotărescu, Cristian; Atiţoaie, Alexandru; Lupu, Nicoleta; Óvári, Tibor-Adrian, E-mail: taovari@phys-iasi.ro; Chiriac, Horia [Department of Magnetic Materials and Devices, National Institute of Research and Development for Technical Physics, Iaşi, 700050 (Romania); Allwood, Dan A. [Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD (United Kingdom)

    2016-05-15

    Results on the control of the domain wall displacement in cylindrical Fe{sub 77.5}Si{sub 7.5}B{sub 15} amorphous glass-coated submicron wires prepared by rapid quenching from the melt are reported. The control methods have relied on conical notches with various depths, up to a few tens of nm, made in the glass coating and in the metallic nucleus using a focused ion beam (FIB) system, and on the use of small nucleation coils at one of the sample ends in order to apply magnetic field pulses aimed to enhance the nucleation of reverse domains. The notch-based method is used for the first time in the case of cylindrical ultrathin wires. The results show that the most efficient technique of controlling the domain wall motion in this type of samples is the simultaneous use of notches and nucleation coils. Their effect depends on wire diameter, notch depth, its position on the wire length, and characteristics of the applied pulse.

  3. Submicron Surface Vibration Profiling Using Doppler Self-Mixing Techniques

    Directory of Open Access Journals (Sweden)

    Tânia Pereira

    2014-01-01

    Full Text Available Doppler self-mixing laser probing techniques are often used for vibration measurement with very high accuracy. A novel optoelectronic probe solution is proposed, based on off-the-shelf components, with a direct reflection optical scheme for contactless characterization of the target’s movement. This probe was tested with two test bench apparatus that enhance its precision performance, with a linear actuator at low frequency (35 µm, 5–60 Hz, and its dynamics, with disc shaped transducers for small amplitude and high frequency (0.6 µm, 100–2500 Hz. The results, obtained from well-established signal processing methods for self-mixing Doppler signals, allowed the evaluation of vibration velocity and amplitudes with an average error of less than 10%. The impedance spectrum of piezoelectric (PZ disc target revealed a maximum of impedance (around 1 kHz for minimal Doppler shift. A bidimensional scan over the PZ disc surface allowed the categorization of the vibration mode (0, 1 and explained its deflection directions. The feasibility of a laser vibrometer based on self-mixing principles and supported by tailored electronics able to accurately measure submicron displacements was, thus, successfully demonstrated.

  4. A new circuit technique for reduced leakage current in Deep Submicron CMOS technologies

    Directory of Open Access Journals (Sweden)

    A. Schmitz

    2005-01-01

    Full Text Available Modern CMOS processes in the Deep Submicron regime are restricted to supply voltages below 2 volts and further to account for the transistors' field strength limitations and to reduce the power per logic gate. To maintain the high switching performance, the threshold voltage must be scaled according with the supply voltage. However, this leads to an increased subthreshold current of the transistors in standby mode (VGS=0. Another source of leakage is gate current, which becomes significant for gate oxides of 3nm and below. We propose a Self-Biasing Virtual Rails (SBVR - CMOS technique which acts like an adaptive local supply voltage in case of standby mode. Most important sources of leakage currents are reduced by this technique. Moreover, SBVR-CMOS is capable of conserving stored information in sleep mode, which is vital for memory circuits. Memories are exposed to radiation causing soft errors. This well-known problem becomes even worse in standby mode of typical SRAMs, that have low driving performance to withstand alpha particle hits. In this paper, a 16-transistor SRAM cell is proposed, which combines the advantage of extremely low leakage currents with a very high soft error stability.

  5. Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics.

    Science.gov (United States)

    Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Jaung, Jae Yun; Kim, Yong-Hoon; Park, Sung Kyu

    2015-09-28

    The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

  6. Minimizing biases associated with tracking analysis of submicron particles in heterogeneous biological fluids.

    Science.gov (United States)

    Wang, Ying-Ying; Nunn, Kenetta L; Harit, Dimple; McKinley, Scott A; Lai, Samuel K

    2015-12-28

    Tracking the dynamic motion of individual nanoparticles or viruses offers quantitative insights into their real-time behavior and fate in different biological environments. Indeed, particle tracking is a powerful tool that has facilitated the development of drug carriers with enhanced penetration of mucus, brain tissues and other extracellular matrices. Nevertheless, heterogeneity is a hallmark of nanoparticle diffusion in such complex environments: identical particles can exhibit strongly hindered or unobstructed diffusion within microns of each other. The common practice in 2D particle tracking, namely analyzing all trackable particle traces with equal weighting, naturally biases towards rapidly diffusing sub-populations at shorter time scales. This in turn results in misrepresentation of particle behavior and a systematic underestimate of the time necessary for a population of nanoparticles to diffuse specific distances. We show here via both computational simulation and experimental data that this bias can be rigorously corrected by weighing the contribution by each particle trace on a 'frame-by-frame' basis. We believe this methodology presents an important step towards objective and accurate assessment of the heterogeneous transport behavior of submicron drug carriers and pathogens in biological environments. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Plastic deformation of submicron-sized crystals studied by in-situ Kikuchi diffraction and dislocation imaging

    DEFF Research Database (Denmark)

    Zhang, Xiaodan; Godfrey, Andrew; Winther, Grethe

    2012-01-01

    confirms that the active dislocations are from slip systems with the highest Schmid factors. These results from testing of micropillars are in good agreement with the deformation behaviour previously reported for both single- and poly-crystal samples with dimensions in the millimetre range. © 2012 Elsevier......The plastic deformation of submicron-size copper single crystals in the form of pillars has been characterized during in-situ compression in the transmission electron microscope up to strains of 28–33% using a state-of-the-art holder (PI-95 PicoIndenter). The dimensions of the crystals used were...... approx. 500×250×200 nm3 with the compression axis oriented 1.6° from [110]. Local crystallographic orientations have been determined with high accuracy using a Kikuchi diffraction method and glide of dislocations over a pillar has also been observed directly by dark field imaging. The variation...

  8. Penetration of sub-micron particles into dentinal tubules using ultrasonic cavitation.

    Science.gov (United States)

    Vyas, N; Sammons, R L; Pikramenou, Z; Palin, W M; Dehghani, H; Walmsley, A D

    2017-01-01

    Functionalised silica sub-micron particles are being investigated as a method of delivering antimicrobials and remineralisation agents into dentinal tubules. However, their methods of application are not optimised, resulting in shallow penetration and aggregation. The aim of this study is to investigate the impact of cavitation occurring around ultrasonic scalers for enhancing particle penetration into dentinal tubules. Dentine slices were prepared from premolar teeth. Silica sub-micron particles were prepared in water or acetone. Cavitation from an ultrasonic scaler (Satelec P5 Newtron, Acteon, France) was applied to dentine slices immersed inside the sub-micron particle solutions. Samples were imaged with scanning electron microscopy (SEM) to assess tubule occlusion and particle penetration. Qualitative observations of SEM images showed some tubule occlusion. The particles could penetrate inside the tubules up to 60μm when there was no cavitation and up to ∼180μm when there was cavitation. The cavitation bubbles produced from an ultrasonic scaler may be used to deliver sub-micron particles into dentine. This method has the potential to deliver such particles deeper into the dentinal tubules. Cavitation from a clinical ultrasonic scaler may enhance penetration of sub-micron particles into dentinal tubules. This can aid in the development of novel methods for delivering therapeutic clinical materials for hypersensitivity relief and treatment of dentinal caries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. One-Step Synthesis and Characterization of Silica Nano-/Submicron Spheres by Catalyst-Assisted Pyrolysis of a Preceramic Polymer

    Directory of Open Access Journals (Sweden)

    Feng Gao

    2013-01-01

    Full Text Available Silica nanospheres have attracted tremendous interest due to their importance in extensive applications. However, the direct large-scale fabrication of silica nanospheres with controlled morphology and high purity remains a significant challenge. In this work, silica nano-/submicron spheres were successfully synthesized by a simple method through pyrolysis of an amorphous polysilazane preceramic powder with catalyst FeCl2. The synthesized spheres possess well-designed shape with diameter of 600–800 nm and high purity. The surfaces of the spheres are smooth and clean without any flaws. Besides, the spheres are identified as amorphous silica, and their growth mechanism was also proposed.

  10. A DC SQUID with instrinsically shunted submicron junctions near the hysteretic limit exhibiting an extremely large dV/dphi-transfer function

    Energy Technology Data Exchange (ETDEWEB)

    Houwman, E.P.; Cantor, R.; Peters, M.; Scheer, H.J.; Koch, H.

    1989-03-01

    A new fabrication process yielding submicron scaled Josephson junctions has been developed. The junction consists of two metal striplines lying in line and separated by a vertical barrier. Thus the contact area is determined by the width and thickness of the stripline. The capacitive coupling is only due to the small contact area, because there is no layer overlap. The process was applied to all Nb thin film junction technology with nitrided Si-barriers. The IV-curves of these junctions show the characteristic features of SNS-contacts. DC SQUIDs made out of these junctions exhibit characteristics competitive to those of high quality tunnel junction DC SQUIDS.

  11. Deciphering sub-micron ice particles on Enceladus surface

    Science.gov (United States)

    Scipioni, F.; Schenk, P.; Tosi, F.; D'Aversa, E.; Clark, R.; Combe, J.-Ph.; Ore, C. M. Dalle

    2017-07-01

    The surface of Saturn's moon Enceladus is composed primarily by pure water ice. The Cassini spacecraft has observed present-day geologic activity at the moon's South Polar Region, related with the formation and feeding of Saturn's E-ring. Plumes of micron-sized particles, composed of water ice and other non-ice contaminants (e.g., CO2, NH3, CH4), erupt from four terrain's fractures named Tiger Stripes. Some of this material falls back on Enceladus' surface to form deposits that extend to the North at ∼40°W and ∼220°W, with the highest concentration found at the South Pole. In this work we analyzed VIMS-IR data to identify plumes deposits across Enceladus' surface through the variation in band depth of the main water ice spectral features. To characterize the global variation of water ice band depths across Enceladus, the entire surface was sampled with an angular resolution of 1° in both latitude and longitude, and for each angular bin we averaged the value of all spectral indices as retrieved by VIMS. The position of the plumes' deposits predicted by theoretical models display a good match with water ice band depths' maps on the trailing hemisphere, whereas they diverge significantly on the leading side. Space weathering processes acting on Enceladus' surface ionize and break up water ice molecules, resulting in the formation of particles smaller than one micron. We also mapped the spectral indices for sub-micron particles and we compared the results with the plumes deposits models. Again, a satisfactory match is observed on the trailing hemisphere only. Finally, we investigated the variation of the depth of the water ice absorption bands as a function of the phase angle. In the visible range, some terrains surrounding the Tiger Stripes show a decrease in albedo when the phase angle is smaller than 10°. This unusual effect cannot be confirmed by near infrared data, since observations with a phase angle lower than 10° are not available. For phase angle

  12. Anthropogenic influences on the physical state of submicron particulate matter over a tropical forest

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, Adam P.; Gong, Zhaoheng; Harder, Tristan H.; de Sá, Suzane S.; Wang, Bingbing; Castillo, Paulo; China, Swarup; Liu, Yingjun; O& amp; apos; Brien, Rachel E.; Palm, Brett B.; Shiu, Hung-Wei; Cirino, Glauber G.; Thalman, Ryan; Adachi, Kouji; Alexander, M. Lizabeth; Artaxo, Paulo; Bertram, Allan K.; Buseck, Peter R.; Gilles, Mary K.; Jimenez, Jose L.; Laskin, Alexander; Manzi, Antonio O.; Sedlacek, Arthur; Souza, Rodrigo A. F.; Wang, Jian; Zaveri, Rahul; Martin, Scot T.

    2017-02-06

    The occurrence of nonliquid and liquid physical states of submicron atmospheric particulate matter (PM) downwind of an urban region in central Amazonia was investigated. Measurements were conducted during two intensive operating periods (IOP1 and IOP2) that took place during the wet and dry seasons of the GoAmazon2014/5 campaign. Air masses representing variable influences of background conditions, urban pollution, and regional- and continental-scale biomass burning passed over the research site. As the air masses varied, particle rebound fraction, an indicator of physical state, was measured in real time at ground level using an impactor apparatus. Micrographs collected by transmission electron microscopy confirmed that liquid particles adhered, while nonliquid particles rebounded. Relative humidity (RH) was scanned to collect rebound curves. When the apparatus RH matched ambient RH, 95 % of the particles adhered as a campaign average. Secondary organic material, produced for the most part by the oxidation of volatile organic compounds emitted from the forest, produces liquid PM over this tropical forest. During periods of anthropogenic influence, by comparison, the rebound fraction dropped to as low as 60 % at 95 % RH. Analyses of the mass spectra of the atmospheric PM by positive-matrix factorization (PMF) and of concentrations of carbon monoxide, total particle number, and oxides of nitrogen were used to identify time periods affected by anthropogenic influences, including both urban pollution and biomass burning. The occurrence of nonliquid PM at high RH correlated with these indicators of anthropogenic influence. A linear model having as output the rebound fraction and as input the PMF factor loadings explained up to 70 % of the variance in the observed rebound fractions. Anthropogenic influences can contribute to the presence of nonliquid PM in the atmospheric particle population through the combined effects of molecular species that increase viscosity

  13. The efficiency and stability of bubble formation by acoustic vaporization of submicron perfluorocarbon droplets

    NARCIS (Netherlands)

    Reznik, Nikita; Shpak, O.; Gelderblom, E.C.; Williams, Ross; de Jong, N.; Versluis, Andreas Michel; Burns, Peter N.

    2013-01-01

    Submicron droplets of liquid perfluorocarbon converted into microbubbles with applied ultrasound have been studied, for a number of years, as potential next generation extravascular ultrasound contrast agents. In this work, we conduct an initial ultra-high-speed optical imaging study to examine the

  14. Analysis and Design of Monolithic Inductors in Sub-micron CMOS

    DEFF Research Database (Denmark)

    Fallesen, Carsten; Jørgensen, Allan

    1997-01-01

    In the last few years the CMOS processes have gone into deep sub-micron channel lengths. This means that it is now possible to make GHz applications in CMOS. In analog GHz applications it is often necessary to have access to inductors. This report describes the development of a physical model of ...

  15. Submicron organic nanofiber devices with different anode-cathode materials: A simple approach

    DEFF Research Database (Denmark)

    Henrichsen, Henrik Hartmann; Sturm, Heinz; Bøggild, Peter

    2010-01-01

    The authors present a simple general method for simultaneously producing tens of submicron electrode gaps with different cathode and anode materials on top of nanofibers, nanowires, and nanotubes, with an optional gap size variation. Using this method, an ensemble of para-hexaphenylene (p6P...

  16. A Comprehensive Evaluation of Nanoparticle Tracking Analysis (NanoSight) for Characterization of Proteinaceous Submicron Particles

    NARCIS (Netherlands)

    Tian, X.; Nejadnik, M.R.; Baunsgaard, D.; Henriksen, A.; Rischel, C.; Jiskoot, W.

    2016-01-01

    Nanoparticle tracking analysis (NTA) has attracted great interest for application in the field of submicron particle characterization for biopharmaceuticals. It has the virtue of direct sample visualization and particle-by-particle tracking, but the complexity of method development has limited its

  17. Thermophoretic motion behavior of submicron particles in boundary-layer-separation flow around a droplet.

    Science.gov (United States)

    Wang, Ao; Song, Qiang; Ji, Bingqiang; Yao, Qiang

    2015-12-01

    As a key mechanism of submicron particle capture in wet deposition and wet scrubbing processes, thermophoresis is influenced by the flow and temperature fields. Three-dimensional direct numerical simulations were conducted to quantify the characteristics of the flow and temperature fields around a droplet at three droplet Reynolds numbers (Re) that correspond to three typical boundary-layer-separation flows (steady axisymmetric, steady plane-symmetric, and unsteady plane-symmetric flows). The thermophoretic motion of submicron particles was simulated in these cases. Numerical results show that the motion of submicron particles around the droplet and the deposition distribution exhibit different characteristics under three typical flow forms. The motion patterns of particles are dependent on their initial positions in the upstream and flow forms. The patterns of particle motion and deposition are diversified as Re increases. The particle motion pattern, initial position of captured particles, and capture efficiency change periodically, especially during periodic vortex shedding. The key effects of flow forms on particle motion are the shape and stability of the wake behind the droplet. The drag force of fluid and the thermophoretic force in the wake contribute jointly to the deposition of submicron particles after the boundary-layer separation around a droplet.

  18. Mountain pine beetle-killed lodgepole pine for the production of submicron lignocellulose fibrils

    Science.gov (United States)

    Ingrid Hoeger; Rolland Gleisner; Jose Negron; Orlando J. Rojas; J. Y. Zhu

    2014-01-01

    The elevated levels of tree mortality attributed to mountain pine beetle (MPB) (Dendroctonus ponderosae Hopkins) in western North American forests create forest management challenges. This investigation introduces the production of submicron or nanometer lignocellulose fibrils for value-added materials from the widely available resource represented by dead pines after...

  19. A Novel Step-Doping Fully-Depleted Silicon-on-Insulator Metal-Oxide-Semiconductor Field-Effect Transistor for Reliable Deep Sub-micron Devices

    Science.gov (United States)

    Elahipanah, Hossein; Orouji, Ali A.

    2009-11-01

    For first time, we report a novel deep sub-micron fully-depleted silicon-on-insulator metal-oxide-semiconductor field-effect-transistor (FD SOI MOSFET) where the channel layer consists of two sections with a step doping (SD) region in order to increase performance and reliability of the device. This new structure that called SD FD SOI structure (SDFD-SOI MOSFET), were used for reaching suitable threshold voltage upon device scaling and reliability improvement. We demonstrate that the electric field was modified in the channel and common peak near the source junction have been reduced in the SDFD-SOI structure. The device demonstrates large enhancements in performance areas such as current drive capability, output resistance, hot-carrier reliability and threshold voltage roll-off. It was found that the device performance is very much dependent upon the SD region parameters. Simulation results show that the proposed structure improved on/off current ratio, and saturated output characteristics compared with conventional SOI structure (C-SOI MOSFET). Also, it was shown that substrate current of SDFD-SOI MOSFET is much lower than the C-SOI MOSFET which presented the lower hot-carrier degradation in proposed MOSFET. Results show that the most short-channel problems in very large scale integrated circuits (VLSI) could be solved and the proposed SDFD-SOI MOSFETs can work very well in deep sub-micron and nanoscale regime.

  20. Deviation from threshold model in ultrafast laser ablation of graphene at sub-micron scale

    Energy Technology Data Exchange (ETDEWEB)

    Gil-Villalba, A.; Xie, C.; Salut, R.; Furfaro, L.; Giust, R.; Jacquot, M.; Lacourt, P. A.; Dudley, J. M.; Courvoisier, F., E-mail: francois.courvoisier@femto-st.fr [Institut FEMTO-ST, UMR 6174 CNRS, Universite de Bourgogne Franche-Comte, 25030 Besançon Cedex (France)

    2015-08-10

    We investigate a method to measure ultrafast laser ablation threshold with respect to spot size. We use structured complex beams to generate a pattern of craters in CVD graphene with a single laser pulse. A direct comparison between beam profile and SEM characterization allows us to determine the dependence of ablation probability on spot-size, for crater diameters ranging between 700 nm and 2.5 μm. We report a drastic decrease of ablation probability when the crater diameter is below 1 μm which we interpret in terms of free-carrier diffusion.

  1. Pressure sensitivity of dislocation density in copper single crystals at submicron scale

    Science.gov (United States)

    Hu, Jianqiao; Chen, Zhen; Liu, Zhanli; Zhuang, Zhuo

    2018-01-01

    It is known that the mechanical responses of metallic samples are insensitive to confining pressure at macroscale. As a result, von Mises elastoplasticity has been commonly used to model metals in engineering practice. With the use of discrete dislocation dynamics in this study, we explore the dislocation behavior of finite-sized copper single crystals of different sizes under uniaxial compression and hydrostatic pressure, respectively. It is found that the dislocation density approaches a stable value with the increase of hydrostatic pressure while it still keeps increasing under uniaxial compression as the size-dependent yield stress is reached. This difference is also dependent on the loading rate. The yield stress under uniaxial compression exhibits the conventional loading rate effect, while the stable value of dislocation density under hydrostatic compression increases with the increase of loading rate. Moreover, a transition from being pressure-insensitive to pressure-sensitive on the evolution of dislocation density is observed under hydrostatic compression as the sample size becomes small. These findings provide useful insights into the elastoplastic responses of metallic samples at microscale.

  2. Dynamics of vortex matter in YBCO sub-micron bridges

    Science.gov (United States)

    Papari, G.; Carillo, F.; Stornaiuolo, D.; Massarotti, D.; Longobardi, L.; Beltram, F.; Tafuri, F.

    2014-11-01

    We have developed a fabrication process that allows us to realize pure YBCO nanowires displaying robust superconductivity at widths w as low as 160 nm. We can modify the process in order to maintain a Au protective layer. This allows us to scale our nanowires even further to widths as low as 50 nm. We have studied how the presence of vortices and the occurrence of phase slips affect the transport properties of nanowires in the width range ξ entry barrier is found to scale with the width. Our findings confirm that for widths ξ < w < λ nanowires are better protected against phase slips and vortex flow.

  3. Metrology of sub-micron structured polymer surfaces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Tosello, Guido; Salaga, J.

    surface replication of the tool insert component when moulding the polymer melt [1]. This aspect is particularly critical when dealing with increasingly small dimensional scales in micro- and nano-structured surfaces [2, 3].In this context, a metrological investigation of polymer replicated surfaces using...

  4. Preparation of a Novel Nano or Submicron Tourmaline Ceramic and Its Ability to Inhibit the Activity of the Sulfate-Reducing Bacterium

    Science.gov (United States)

    Li, Chun-ying

    2017-07-01

    In this study, novel nano- or submicron-scale tourmaline bacteriostatic ceramics in which nano or submicron tourmaline is one of the central materials, together with nano-zinc oxide, are prepared using ion exchange and solid-phase synthesis techniques. The material is then examined with IR, XRD and XPS and is tested for the ability to inhibit the activity of the sulfate-reducing bacterium (SRB). The calcination temperature of the ceramic is 600 °C, and the main components are present at 11.17% for Si2p, 3.12% for Mo3d, 3.47% for Zn2p3, 2.86% for Mn2p and 2.35% for Cu2p. Additionally, the density of this material is 1.4-3.5 g/cm3, and its compressive strength exceeds 5.2 MPa, meeting the requirements of ceramic standards. Consequently, the bacteriostatic ceramic inhibits the activity of the sulfate-reducing bacterium effectively without inhibiting the removal of COD and NO3 -. These results indicate that the sulfate-reducing bacterium maintains its functional metabolism, apart from its sulfate reduction potential, when using this bacteriostatic ceramic, thus achieving the goal of inhibiting the action of the sulfate-reducing bacterium.

  5. Enhancements of the refractory submicron aerosol fraction in the Arctic polar vortex: feature or exception?

    Science.gov (United States)

    Weigel, R.; Volk, C. M.; Kandler, K.; Hösen, E.; Günther, G.; Vogel, B.; Grooß, J.-U.; Khaykin, S.; Belyaev, G. V.; Borrmann, S.

    2014-11-01

    In situ measurements with a four-channel stratospheric condensation particle counter (CPC) were conducted at up to 20 km altitude on board the aircraft M-55 Geophysica from Kiruna, Sweden, in January through March (EUPLEX 2003, RECONCILE 2010) and in December (ESSenCe 2011). During all campaigns air masses from the upper stratosphere and mesosphere were subsiding inside the Arctic winter vortex, thus initializing a transport of refractory aerosol into the lower stratosphere (Θ content of nitrous oxide (70 nmol mol-1 of N2O). This indicates that refractory aerosol originates from the upper stratosphere or the mesosphere. Derived from the mixing ratio of the simultaneously measured long-lived tracer N2O, an empirical index serves to differentiate probed air masses according to their origin: inside the vortex, the vortex edge region, or outside the vortex. Previously observed high fractions of refractory submicron aerosol in the 2003 Arctic vortex were ascribed to unusually strong subsidence during that winter. However, measurements under perturbed vortex conditions in 2010 and during early winter in December 2011 revealed similarly high values. Thus, the abundance of refractory aerosol in the lower stratosphere within the Arctic vortices appears to be a regular feature rather than the exception. During December, the import from aloft into the lower stratosphere appears to be developing; thereafter the abundance of refractory aerosol inside the vortex reaches its highest levels in March. The correlations of refractory aerosol with N2O suggest that, apart from mean subsidence, diabatic dispersion inside the vortex significantly contributes to the transport of particles to the Arctic lower stratosphere. A measurement-based estimate of the total mass of refractory aerosol inside the vortex is provided for each campaign. Based on the derived increase of particle mass in the lower stratospheric vortex (100-67 hPa pressure altitude) by a factor of 4.5 between early and

  6. Influence of locational states of submicron fibers added into matrix on mechanical properties of plain-woven Carbon Fiber Composite

    National Research Council Canada - National Science Library

    Soichiro Kumamoto; Kazuya Okubo; Toru Fujii

    2016-01-01

    The aim of this study was to show the influence of locational states of submicron fibers added into epoxy matrix on mechanical properties of modified plane-woven carbon fiber reinforced plastic (CFRP...

  7. Moment expansion approach to calculate impact ionization rate in submicron silicon devices

    Science.gov (United States)

    Sonoda, Ken-ichiro; Yamaji, Mitsuru; Taniguchi, Kenji; Hamaguchi, Chihiro; Dunham, Scott T.

    1996-11-01

    A method to calculate the impact ionization rate in submicron silicon devices is developed using both an average energy and an average square energy of electrons. The method consists of an impact ionization model formulated with the average energy and conservation equations for the average square energy in the framework of an energy transport model. Parameters for the transport equations are extracted in such a way that calculated moments based on these equations match Monte Carlo simulation results. The impact ionization generation rate in an n+nn+ structure calculated with this method agrees well with the results obtained from Monte Carlo simulation. The new method is also applied to a submicron n-MOSFET. The calculated distribution of the generation rate is found to be quite different from the results based on a conventional method.

  8. Separation of submicron particles from biofuel combustion with flue gas condensation or wet condensing electrostatic precipitator. Analysis of possibilities; Avskiljning av submikrona partiklar vid biobraenslefoerbraenning med roekgaskondensering eller kondenserande vaata elfilter. Analys av moejligheterna

    Energy Technology Data Exchange (ETDEWEB)

    Roennbaeck, Marie; Gustavsson, Lennart [Swedish National Testing and Research Inst., Boraas (Sweden)

    2006-11-15

    particles with high resistivity. The wet electrostatic precipitator can be designed condensing, and in doing this the latent heat of condensation can be recovered. Ongoing and published R and D show that basic studies concerning larger biofuel plants are in progress. On smaller appliances (from single house-scale up to three MW), there are some studies published and several ongoing. The published studies from smaller appliances have targeted high degree of separation, high availability and good economy without pre-separation of dust. It may be possible to use experience from small scale appliances to larger plants in the sphere of interest of Vaermeforsk. The literature survey shows that it is theoretically possible to separate submicron particles using flue gas condensation, or using a wet electrostatic precipitator. A next step is to investigate the economy and to apply and evaluate technique. Simultaneously, the knowledge about formation and reduction mechanism of dust from biofuels has to increase, in order to reduce the need for secondary cleaning of flue gas. The ongoing studies should be followed up.

  9. The surface characterisation and comparison of two potential sub-micron, sugar bulking excipients for use in low-dose, suspension formulations in metered dose inhalers.

    Science.gov (United States)

    James, Jeff; Crean, Barry; Davies, Martyn; Toon, Richard; Jinks, Phil; Roberts, Clive J

    2008-09-01

    This study compares the surface characteristics and surface energetics of two potential bulking excipients, anhydrous sub-micron alpha-lactose and sub-micron sucrose, for use with low-dose, suspension formulations in pressurised metered dose inhalers (pMDIs). Both sub-micron bulking excipients are processed from parent materials (alpha-lactose monohydrate/alpha-lactose monohydrate and silk grade sucrose, respectively) so the surface characteristics of each material were determined and compared. Additionally, the surface energetics and adhesive interactions between each sub-micron bulking excipient and some chosen active pharmaceutical ingredients (APIs) used in pMDI formulations were also determined. From this data, it was possible to predict the potential degree of interaction between the APIs and each sub-micron bulking excipient, thus determining suitable API-excipient combinations for pMDI formulation optimisation. Salmon calcitonin was also investigated as a potential API due to the current interest in, and the potential low-dose requirements for, the pulmonary delivery of proteins. The size and morphology of each sub-micron excipient (and parent materials) were determined using scanning electron microscopy (SEM) and the crystalline nature of each sub-micron excipient and parent material was assessed using X-ray diffraction (XRD). The surface chemistry of each sub-micron excipient was analysed using X-ray photoelectron spectroscopy (XPS). The surface energies of each sub-micron excipient, along with their respective parent materials and any intermediates, were determined using two techniques. The surface energies of these materials were determined via (a) single particle adhesive interactions using atomic force microscopy (AFM) and (b) 'bulk' material surface interactions using contact angle measurements (CA). From the CA data, it was possible to calculate the theoretical work of adhesion values for each API-excipient interaction using the surface component

  10. Submicron ionography of nanostructures using a femtosecond-laser-driven-cluster-based source

    OpenAIRE

    Faenov, A. Ya; Pikuz, T. A.; Fukuda, Y.(Miyagi University of Education, Department of Physics, Sendai, Japan); Kando, M; Kotaki, H.; Homma, T.; KAWASE, K; Kameshima, T.; Pirozkhov, A.; Yogo, A.; Tampo, M.; Mori, M.; Sakaki, H.; Hayashi, Y; Nakamura, T.

    2009-01-01

    An intense isotropic source of multicharged carbon and oxygen ions with energy above 300 keV and particle number >108 per shot was obtained by femtosecond Ti:Sa laser irradiation of submicron clusters. The source was employed for high-contrast contact ionography images with 600 nm spatial resolution. A variation in object thickness of 100 nm was well resolved for both Zr and polymer foils.

  11. Comprehensive investigation of the dynamics of micron and submicron lunar ejecta in heliocentric space

    Energy Technology Data Exchange (ETDEWEB)

    Hargrave, A.D.

    1984-01-01

    The forces which act on micron and submicron dust particles in interplanetary space are studied in detail. Particular attention is given to Mie scattering theory as it applies to the calculation of the force due to radiation pressure. All of the forces are integrated into a computer model to study the heliocentric orbits of lunar ejecta. It is shown that lunar ejecta contribute to a geocentric dust cloud, as well as to a heliocentric dust belt.

  12. Assessment of Sub-Micron Particles by Exploiting Charge Differences with Dielectrophoresis

    Directory of Open Access Journals (Sweden)

    Maria F. Romero-Creel

    2017-08-01

    Full Text Available The analysis, separation, and enrichment of submicron particles are critical steps in many applications, ranging from bio-sensing to disease diagnostics. Microfluidic electrokinetic techniques, such as dielectrophoresis (DEP have proved to be excellent platforms for assessment of submicron particles. DEP is the motion of polarizable particles under the presence of a non-uniform electric field. In this work, the polarization and dielectrophoretic behavior of polystyrene particles with diameters ranging for 100 nm to 1 μm were studied employing microchannels for insulator based DEP (iDEP and low frequency (<1000 Hz AC and DC electric potentials. In particular, the effects of particle surface charge, in terms of magnitude and type of functionalization, were examined. It was found that the magnitude of particle surface charge has a significant impact on the polarization and dielectrophoretic response of the particles, allowing for successful particle assessment. Traditionally, charge differences are exploited employing electrophoretic techniques and particle separation is achieved by differential migration. The present study demonstrates that differences in the particle’s surface charge can also be exploited by means of iDEP; and that distinct types of nanoparticles can be identified by their polarization and dielectrophoretic behavior. These findings open the possibility for iDEP to be employed as a technique for the analysis of submicron biological particles, where subtle differences in surface charge could allow for rapid particle identification and separation.

  13. Continuous Draw Spinning of Extra-Long Silver Submicron Fibers with Micrometer Patterning Capability.

    Science.gov (United States)

    Bai, Xiaopeng; Liao, Suiyang; Huang, Ya; Song, Jianan; Liu, Zhenglian; Fang, Minghao; Xu, Chencheng; Cui, Yi; Wu, Hui

    2017-03-08

    Ultrathin metal fibers can serve as highly conducting and flexible current and heat transport channels, which are essential for numerous applications ranging from flexible electronics to energy conversion. Although industrial production of metal fibers with diameters of down to 2 μm is feasible, continuous production of high-quality and low-cost nanoscale metal wires is still challenging. Herein, we report the continuous draw spinning of highly conductive silver submicron fibers with the minimum diameter of ∼200 nm and length of more than kilometers. We obtained individual AgNO3/polymer fibers by continuous drawing from an aqueous solution at a speed of up to 8 m/s. With subsequent heat treatment, freestanding Ag submicron fibers with high mechanical flexibility and electric conductivity have been obtained. Woven mats of aligned Ag submicron fibers were used as transparent electrodes with high flexibility and high performance with sheet resistance of 7 Ω sq(-1) at a transparency of 96%. Continuous draw spinning opened new avenues for scalable, flexible, and ultralow-cost fabrication of extra-long conductive ultrathin metal fibers.

  14. Influence of PEG Stoichiometry on Structure-Tuned Formation of Self-Assembled Submicron Nickel Particles

    Directory of Open Access Journals (Sweden)

    Bingxue Pu

    2018-01-01

    Full Text Available Self-assembled submicron nickel particles were successfully synthesized via the one-step surfactant-assisted solvothermal method. The impact of surfactant and reducing agent stoichiometry is investigated in this manuscript. Different morphologies and structures of Ni particles, including flower-like nanoflakes, hydrangea-like structures, chain structures, sphere-like structures, and hollow structures were prepared through different processing conditions with two parameters such as temperature and time. Based on scanning electron microscopy (SEM, X-ray diffraction (XRD, thermal gravimetric analysis (TGA and vibrating sample magnetometry (VSM, the submicron nickel particles show good saturation magnetization and excellent thermal stabilities with a possible growth mechanism for the variety of the structure-tuned formation. Importantly, the microwave absorption properties of the submicron nickel particles were studied. The lowest reflection loss of Ni-P9/T200/H15 with a thin layer thickness of 1.7 mm can reach −42.6 dB at 17.3 GHz.

  15. The study to reduce the hemolysis side effect of puerarin by a submicron emulsion delivery system.

    Science.gov (United States)

    Yue, Peng-Fei; Hai-Long Yuan, Hai-Long; Zhu, Wei-Feng; Cong, Long-Bo; Xie, Huan; Liu, Zhi-Guo; Wang, Lu-Jun; Xiao, Xiao-He

    2008-01-01

    A safe and effective delivery system with a submicron emulsion for puerarin was studied. Puerarin submicron emulsion was prepared by a novel complex-phase inversion-high press homogenization technology. The mechanism to reduce the hemolysis side effect of puerarin was studied by blood cell counts in rabbits. The average diameter, zeta potential and entrapment efficiency of the emulsion prepared was 198.14+/-8.61 nm, -29.45+/-1.47 mV, 87.32+/-0.34%, respectively. Compared with control group, the red blood cell values, packed cell volume, plasma hemoglobin level, haptoglobin level and osmotic fragility of puerarin i.v. group was significantly different (pemulsion group were not significantly different (p>0.05) in contrast to control group. Such observations indicated that the intravascular hemolysis occurred at 42, 43 d in puerarin i.v. group rabbits, the hemolysis did not occur for puerarin emulsion group rabbits. As an explanation for these results, it was proposed that the puerarin was either incorporated into the lipophilic core or intercalated between the phospholipid molecules at the interface. It could be concluded that puerarin submicron emulsions prepared markedly reduced the hemolysis effect of puerarin.

  16. A flow cytometry-based submicron-sized bacterial detection system using a movable virtual wall.

    Science.gov (United States)

    Choi, Hyoungseon; Jeon, Chang Su; Hwang, Inseong; Ko, Juhui; Lee, Saram; Choo, Jaebum; Boo, Jin-Hyo; Kim, Hee Chan; Chung, Taek Dong

    2014-07-07

    Detection of pathogenic bacteria requires a sensitive, accurate, rapid, and portable device. Given that lethal microbes are of various sizes, bacterial sensors based on DC (direct current) impedance on chips should be equipped with channels with commensurate cross sections. When it comes to counting and interrogation of individual bacteria on a microfluidic chip, very narrow channels are required, which are neither easy nor cost-effective to fabricate. Here, we report a flow cytometry-based submicron-sized bacterial detection system using a movable virtual wall made of a non-conducting fluid. We show that the effective dimension of a microfluidic channel can be adjusted by varying the respective flow rates of a sample solution as well as the liquid wall therein. Using such a virtual wall, we have successfully controlled the channel width and detected submicron-sized Francisella tularensis, a lethal, tularemia-causing bacterium. Since the system is capable of monitoring changes in DC impedance and fluorescence simultaneously, we were also able to discriminate between different types of bacterial mixtures containing F. tularensis and E. coli BL21 that have different gamuts of size distributions. The proposed flow cytometry-based system represents a promising way to detect bacteria including, but not limited to, submicron-sized pathogenic microbes.

  17. Aerodynamics and deposition effects of inhaled submicron drug aerosol in airway diseases.

    Science.gov (United States)

    Faiyazuddin, Md; Mujahid, Md; Hussain, Talib; Siddiqui, Hefazat H; Bhatnagar, Aseem; Khar, Roop K; Ahmad, Farhan J

    2013-01-01

    Particle engineering is the prime focus to improve pulmonary drug targeting with the splendor of nanomedicines. In recent years, submicron particles have emerged as prettyful candidate for improved fludisation and deposition. For effective deposition, the particle size must be in the range of 0.5-5 μm. Inhalers design for the purpose of efficient delivery of powders to lungs is again a crucial task for pulmonary scientists. A huge number of DPI devices exist in the market, a significant number are awaiting FDA approval, some are under development and a large number have been patented or applied for patent. Even with superior design, the delivery competence is still deprived, mostly due to fluidisation problems which cause poor aerosol generation and deposition. Because of the cohesive nature and poor flow characteristics, they are difficult to redisperse upon aerosolization with breath. These problems are illustrious in aerosol research, much of which is vastly pertinent to pulmonary therapeutics. A technical review is presented here of advances that have been utilized in production of submicron drug particles, their in vitro/in vivo evaluations, aerosol effects and pulmonary fate of inhaled submicron powders.

  18. Development of high efficient ESP for submicron particle collection. Sabumikuron ryushi no kokoritsu shujin hoshiki no kaihatsu. ; Seiden gyoshu sochi naizo denki shujin hoshiki no gyoshusayo to shujin koritsu

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T.; Suda, T.

    1989-11-01

    The result of testing the operation of an electrostatic agglomeration appratus (ESA) is reported, which has been developed at Central Research Institute of Electric Power Industry (CRIEPI). Details of the apparatus is given in the authors {prime} previous papaer (1988). At first a description is given of an apparatus which produces the aerosol for laboratory use comprising submicron-sized carbon particles and micron-sized flyash particles. This aerosol is similar in quality to that produced by a combustion furnance at CRIEPI. An apparatus provided with mesh electrodes for charging aerosol particles is also developed. Thus preparing aerosol samples, the effect of agglomeration produced by the ESA On the samples is examined to demonstrate that particle sizes in diameter are increased by a factor of four on average and the percentage of submicron-sized particles (less than 1 {mu} m in diameter) is reduced by 20% in weight. Combined with this type of ESA, the efficiency of ESP (electrostatic precipitator) in collecting submicron-sized particles is theoretically calculated to increase by about 1 - 3% when it is used at a thermal power plant of 520MW. 4refs., 21 figs., 6 tabs.

  19. Aerosols in the tropical and subtropical UT/LS: in-situ measurements of submicron particle abundance and volatility

    Directory of Open Access Journals (Sweden)

    S. Borrmann

    2010-06-01

    Full Text Available Processes occurring in the tropical upper troposphere (UT, the Tropical Transition Layer (TTL, and the lower stratosphere (LS are of importance for the global climate, for stratospheric dynamics and air chemistry, and for their influence on the global distribution of water vapour, trace gases and aerosols. In this contribution we present aerosol and trace gas (in-situ measurements from the tropical UT/LS over Southern Brazil, Northern Australia, and West Africa. The instruments were operated on board of the Russian high altitude research aircraft M-55 "Geophysica" and the DLR Falcon-20 during the campaigns TROCCINOX (Araçatuba, Brazil, February 2005, SCOUT-O3 (Darwin, Australia, December 2005, and SCOUT-AMMA (Ouagadougou, Burkina Faso, August 2006. The data cover submicron particle number densities and volatility from the COndensation PArticle counting System (COPAS, as well as relevant trace gases like N2O, ozone, and CO. We use these trace gas measurements to place the aerosol data into a broader atmospheric context. Also a juxtaposition of the submicron particle data with previous measurements over Costa Rica and other tropical locations between 1999 and 2007 (NASA DC-8 and NASA WB-57F is provided. The submicron particle number densities, as a function of altitude, were found to be remarkably constant in the tropical UT/LS altitude band for the two decades after 1987. Thus, a parameterisation suitable for models can be extracted from these measurements. Compared to the average levels in the period between 1987 and 2007 a slight increase of particle abundances was found for 2005/2006 at altitudes with potential temperatures, Θ, above 430 K. The origins of this increase are unknown except for increases measured during SCOUT-AMMA. Here the eruption of the Soufrière Hills volcano in the Caribbean caused elevated particle mixing ratios. The vertical profiles from Northern hemispheric mid-latitudes between 1999 and 2006 also are

  20. A bioactive coating with submicron-sized titania crystallites fabricated by induction heating of titanium after tensile deformations.

    Science.gov (United States)

    Li, Ning-Bo; Xu, Wen-Hua; Xiao, Gui-Yong; Zhao, Jun-Han; Lu, Yu-Peng

    2017-11-01

    Thermal oxidation technology was widely investigated as one of effective surface modification method for improving the bioactivity and biocompatibility of titanium and its alloys. In this work, the induction heat oxidization method, a fast, efficient, economical and environmental protective technology, was applied to prepare the submicron-morphological oxide coating with variable rutile TiO2 equiaxed crystallites on the surface of pure Ti substrates after cold-drawing with 10-20% deformations. The results showed the plastic-deformed Ti cylinders recrystallized during induction heating treatment (IHT) for 10-20s which resulted in evolution of microstructures as well as slight improvement of microhardness. The surface characteristics of TiO2 crystallites in oxidation layers were determined by the microstructural evolutions of Ti substrate in terms of the nucleation and growth of TiO2 crystallites. Specially, the oxidized surface with 50-75nm roughness and more uniform and finer equiaxed oxide grains remarkablely improved the apatite deposition after bioactive evaluation in 1.5 × SBF for 7 days. This work provided a potential method to create controlled bioactive oxide coatings with submicro-/nano-scaled TiO2 crystallites on titanium substrate in terms of the role of metallographic microstructure in the formation process of titanium oxides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Evaluating model parameterizations of submicron aerosol scattering and absorption with in situ data from ARCTAS 2008

    Directory of Open Access Journals (Sweden)

    M. J. Alvarado

    2016-07-01

    Full Text Available Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS campaign. The four models are the NASA Global Modeling Initiative (GMI Combo model, GEOS-Chem v9-02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT, and the Optical Properties of Aerosol and Clouds (OPAC v3.1 package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1 to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution are used, and examine the impact of different mixing rules for black carbon (BC on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10–23 %, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GC-RT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding a variable size distribution, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass

  2. Development of a reflective optical encoder with submicron accuracy

    Science.gov (United States)

    Ye, Guoyong; Liu, Hongzhong; Ban, Yaowen; Shi, Yongsheng; Yin, Lei; Lu, Bingheng

    2018-03-01

    Signal distortion is a key issue that limits the measurement resolution and accuracy of optical encoders. In this paper, an optical encoder based on generalized grating imaging using a two-dimensional index grating is presented. The general expression of intensity distribution for generalized grating imaging including the relative displacement between the scale grating and the reading head is derived, and the formation of the signal distortion of the optical encoder is analyzed. Then, a two-dimensional index grating, which consists of multiple grating tracks with defined offsets, is proposed to suppress the dominant third and fifth order harmonic signals. The operating principle of the two-dimensional index grating is explained in detail and a reflective optical encoder is developed. In the experiment, approximately ideal Lissajous figure of the encoder signals is obtained. Fourier analysis of the encoder signals shows that both the third and fifth order harmonic distortions are below 0.6%. Experimental results show that the interpolation error of the optical encoder is within ± 0 . 18 μm, and the accuracy is better than ± 0 . 3 μm over 255 mm travel range with a maximum variation of 0.136 μm.

  3. Electron Beam Column Developments for Submicron- and Nanolithography

    Science.gov (United States)

    Gesley, Mark; Abboud, Frank; Colby, Dave; Raymond, Frederick; Watson, Sterling

    1993-12-01

    Recent advances in thermal field emission (TFE) electron beam optics column design for lithography are described. Innovations include source vibration mode mapping, accelerating electron gun lens, gun arc-suppression, automated cathode pyrometer, and experimental deflection control system. Several of these column optics and system enhancements, which improve the accuracy and reliability of MEBES\\textregistered IV-TFE systems, have enabled patterning of 64 Mbit dynamic random access memory (DRAM) 5×-reduction reticles. A 13000-hour cathode lifetime has been achieved in a production environment. Automated column setups over the entire operating range with 99% success and 5 min average times are possible. Blanking at 160 MHz with 30 nm (3σ) critical dimension control is achieved. Data obtained with a new experimental deflection control method can quickly compensate stripe butting drift to high accuracy. Challenges in mask patterning for advanced applications are then considered. Several accuracy and throughput issues for advanced 5× reticles for DRAM, 1× masks, and nanolithography are discussed. Examples are given of scaling recent system data as a means of estimating future error budget components.

  4. Influence of locational states of submicron fibers added into matrix on mechanical properties of plain-woven Carbon Fiber Composite

    Science.gov (United States)

    Kumamoto, Soichiro; Okubo, Kazuya; Fujii, Toru

    2016-01-01

    The aim of this study was to show the influence of locational states of submicron fibers added into epoxy matrix on mechanical properties of modified plane-woven carbon fiber reinforced plastic (CFRP). To change the locational states of submicron fibers, two kinds of fabrication processes were applied in preparing specimen by hand lay-up method. Submicron fibers were simply added into epoxy resin with ethanol after they were stirred by a dispersion process using homogenizer to be located far from the interface between reinforcement and matrix. In contrast, submicron fibers were attached onto the carbon fibers by injecting from a spray nozzle accompanying with ethanol to be located near the interface, after they were tentatively contained in ethanol. The plain-woven CFRP plates were fabricated by hand lay-up method and cured at 80 degree-C for 1 hour and then at 150 degree-C for 3 hours. After curing, the plain-woven CFRP plates were cut into the dimension of specimen. Tensile shear strength and Mode-II fracture toughness of CFRP were determined by tensile lap-shear test and End-notched flexure(ENF) test, respectively. When submicron fibers were located far from the interface between carbon fibers and epoxy resin, tensile shear strength and Mode-II fracture toughness of CFRP were improved 30% and 18% compared with those of unmodified case. The improvement ratio in modified case was rather low (about few percentages) in the case where submicron fibers were located near the interface. The result suggested that crack propagation should be prevented when submicron fibers were existed far from the interface due to the effective stress state around the crack tip.

  5. Influence of locational states of submicron fibers added into matrix on mechanical properties of plain-woven Carbon Fiber Composite

    Directory of Open Access Journals (Sweden)

    Kumamoto Soichiro

    2016-01-01

    Full Text Available The aim of this study was to show the influence of locational states of submicron fibers added into epoxy matrix on mechanical properties of modified plane-woven carbon fiber reinforced plastic (CFRP. To change the locational states of submicron fibers, two kinds of fabrication processes were applied in preparing specimen by hand lay-up method. Submicron fibers were simply added into epoxy resin with ethanol after they were stirred by a dispersion process using homogenizer to be located far from the interface between reinforcement and matrix. In contrast, submicron fibers were attached onto the carbon fibers by injecting from a spray nozzle accompanying with ethanol to be located near the interface, after they were tentatively contained in ethanol. The plain-woven CFRP plates were fabricated by hand lay-up method and cured at 80 degree-C for 1 hour and then at 150 degree-C for 3 hours. After curing, the plain-woven CFRP plates were cut into the dimension of specimen. Tensile shear strength and Mode-II fracture toughness of CFRP were determined by tensile lap-shear test and End-notched flexure(ENF test, respectively. When submicron fibers were located far from the interface between carbon fibers and epoxy resin, tensile shear strength and Mode-II fracture toughness of CFRP were improved 30% and 18% compared with those of unmodified case. The improvement ratio in modified case was rather low (about few percentages in the case where submicron fibers were located near the interface. The result suggested that crack propagation should be prevented when submicron fibers were existed far from the interface due to the effective stress state around the crack tip.

  6. A novel multi-level IC-compatible surface microfabrication technology for MEMS with independently controlled lateral and vertical submicron transduction gaps

    Science.gov (United States)

    Cicek, Paul-Vahe; Elsayed, Mohannad; Nabki, Frederic; El-Gamal, Mourad

    2017-11-01

    An above-IC compatible multi-level MEMS surface microfabrication technology based on a silicon carbide structural layer is presented. The fabrication process flow provides optimal electrostatic transduction by allowing the creation of independently controlled submicron vertical and lateral gaps without the need for high resolution lithography. Adopting silicon carbide as the structural material, the technology ensures material, chemical and thermal compatibility with modern semiconductor nodes, reporting the lowest peak processing temperature (i.e. 200 °C) of all comparable works. This makes this process ideally suited for integrating capacitive-based MEMS directly above standard CMOS substrates. Process flow design and optimization are presented in the context of bulk-mode disk resonators, devices that are shown to exhibit improved performance with respect to previous generation flexural beam resonators, and that represent relatively complex MEMS structures. The impact of impending improvements to the fabrication technology is discussed.

  7. [Nasal submicron emulsion of Scutellariae Radix extract preparation technology research based on phase transfer of solute technology].

    Science.gov (United States)

    Shi, Ya-jun; Shi, Jun-hui; Chen, Shi-bin; Yang, Ming

    2015-07-01

    Based on the demand of nasal drug delivery high drug loadings, using the unique phase transfer of solute, integrating the phospholipid complex preparation and submicron emulsion molding process of Scutellariae Radix extract, the study obtained the preparation of the high drug loadings submicron emulsion of Scutellariae Radix extract. In the study of drug solution dispersion method, the uniformity of drug dispersed as the evaluation index, the traditional mixing method, grinding, homogenate and solute phase transfer technology were investigated, and the solute phase transfer technology was adopted in the last. With the adoption of new technology, the drug loading capacity reached 1.33% (phospholipid complex was 4%). The drug loading capacity was improved significantly. The transfer of solute method and timing were studied as follows,join the oil phase when the volume of phospholipid complex anhydrous ethanol solution remaining 30%, the solute phase transfer was completed with the continued recycling of anhydrous ethanol. After drug dissolved away to oil phase, the preparation technology of colostrum was determined with the evaluation index of emulsion droplet form. The particle size of submicron emulsion, PDI and stability parameters were used as evaluation index, orthogonal methodology were adopted to optimize the submicron emulsion ingredient and main influential factors of high pressure homogenization technology. The optimized preparation technology of Scutellariae Radix extract nasal submicron emulsion is practical and stable.

  8. A novel inlet system for online chemical analysis of semi-volatile submicron particulate matter

    Science.gov (United States)

    Eichler, P.; Müller, M.; D'Anna, B.; Wisthaler, A.

    2015-03-01

    We herein present a novel modular inlet system designed to be coupled to low-pressure gas analyzers for online chemical characterization of semi-volatile submicron particles. The "chemical analysis of aerosol online" (CHARON) inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle collimation combined with an inertial sampler for the particle-enriched flow and a thermodesorption unit for particle volatilization prior to chemical analysis. The denuder was measured to remove gas-phase organics with an efficiency > 99.999% and to transmit particles in the 100-750 nm size range with a 75-90% efficiency. The measured average particle enrichment factor in the subsampling flow from the aerodynamic lens was 25.6, which is a factor of 3 lower than the calculated theoretical optimum. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) which quantitatively detects most organic analytes and ammonia. The combined CHARON-PTR-ToF-MS setup is thus capable of measuring both the organic and the ammonium fraction in submicron particles in real time. Individual organic compounds can be detected down to levels of 10-20 ng m-3. Two proof-of-principle studies were carried out for demonstrating the analytical power of this new instrumental setup: (i) oxygenated organics and their partitioning between the gas and the particulate phase were observed from the reaction of limonene with ozone and (ii) nicotine was measured in cigarette smoke particles demonstrating that selected organic target compounds can be detected in submicron particles in real time.

  9. Impact-disrupted gunshot residue: A sub-micron analysis using a novel collection protocol

    Directory of Open Access Journals (Sweden)

    V. Spathis

    2017-06-01

    Full Text Available The analysis of gunshot residue (GSR has played an integral role within the legal system in relation to shooting cases. With a characteristic elemental composition of lead, antimony, barium, and a typically discriminative spheroidal morphology, the presence and distribution of GSR can aid in firearm investigations. In this experiment, three shots of low velocity rim-fire ammunition were fired over polished silicon collection substrates placed at six intervals over a 100 cm range. The samples were analysed using a Field Emission Gun Scanning Electron Microscope (FEG-SEM in conjunction with an X-flash Energy Dispersive X-ray (EDX detector, allowing for GSR particle analyses of composition and structure at the sub-micron level. The results of this experiment indicate that although classic spheroidal particles are present consistently throughout the entire range of samples their sizes vary significantly, and at certain distances from the firearm particles with an irregular morphology were discerned, forming “impact-disrupted” GSR particles, henceforth colloquially referred to as “splats”. Upon further analysis, trends with regards to the formation of these splat particles were distinguished. An increase in splat frequency was observed starting at 10 cm from the firearm, with 147 mm−2 splat density, reaching a maximal flux at 40 cm (451 mm−2, followed by a gradual decrease to the maximum range sampled. Moreover, the structural morphology of the splats changes throughout the sampling range. At the distances closest to the firearm, molten-looking particles were formed, demonstrating the metallic residues were in a liquid state when their flight path was disrupted. However, at increased distances-primarily where the discharge plume was at maximum dispersion and moving away from the firearm, the residues have had time to cool in-fight resulting in semi-congealed and solid particles that subsequently disrupted upon impact, forming more

  10. Reduced impact of induced gate noise on inductively degenerated LNAs in deep submicron CMOS technologies

    DEFF Research Database (Denmark)

    Rossi, P.; Svelto, F.; Mazzanti, A.

    2005-01-01

    Designers of radio-frequency inductively-degenerated CMOS low-noise-amplifiers have usually not followed the guidelines for achieving minimum noise figure. Nonetheless, state-of-the- art implementations display noise figure values very close to the theoretical minimum. In this paper, we point out...... that this is due to the effect of the parasitic overlap capacitances in the MOS device. In particular, we show that overlap capacitances lead to a significant induced-gate-noise reduction, especially when deep sub-micron CMOS processes are used....

  11. Note: Aligned deposition and modal characterization of micron and submicron poly(methyl methacyrlate) fiber cantilevers.

    Science.gov (United States)

    Nain, Amrinder S; Filiz, Sinan; Ozdoganlar, O Burak; Sitti, Metin; Amon, Cristina

    2010-01-01

    Polymeric micro-/nanofibers are finding increasing use as sensors for novel applications. Here, we demonstrate the ability to deposit an array of poly(methyl methacyrlate) fibers with micron and submicron diameters in aligned configurations on customized piezoelectric shakers. Using lateral motion of an atomic force microscope tip, fibers are broken to obtain fiber cantilevers of high aspect ratio (length/diameter > 20). The resonant frequencies of fabricated microfiber cantilevers are experimentally measured using a laser Doppler vibrometer. An average Young's modulus of 3.5 GPa and quality factor of 20 were estimated from the experimentally obtained frequency responses.

  12. Pressing Induced Polymorphic Phase Transition in Submicron-Sized Gamma-Hmx

    Science.gov (United States)

    Lee, K.-Y.; Moore, D. S.

    2007-12-01

    Using Raman spectroscopy, a novel submicron-sized HMX (sm-HMX) was determined to be both the gamma polymorph and stable with respect to conversion to beta-HMX under ambient conditions for at least a year. Pressing of sm-HMX powder in a small diameter pellet press at pressures from 10,000 psi to 31,000 psi and 1 to 5 minute hold times was found to promote the gamma to beta polymorphic phase transition. The fraction converted and rate of conversion versus time after pellet removal from the press, measured using Raman spectroscopy, fit a sigmoidal curve, indicating nucleation and growth as a possible polymorphic transition mechanism.

  13. Bloch-wave engineered submicron-diameter quantum-dot micropillars for cavity QED experiments

    DEFF Research Database (Denmark)

    Gregersen, Niels; Lermer, Matthias; Reitzenstein, Stephan

    2013-01-01

    The semiconductor micropillar is attractive for cavity QED experiments. For strong coupling, the figure of merit is proportional to Q/√V, and a design combining a high Q and a low mode volume V is thus desired. However, for the standard submicron diameter design, poor mode matching between the ca...... the cavity and the DBR Bloch mode limits the Q. We present a novel adiabatic design where Bloch-wave engineering is employed to improve the mode matching, allowing the demonstration of a record-high vacuum Rabi splitting of 85 μeV and a Q of 13600 for a 850 nm diameter micropillar....

  14. An Empirical Algorithm for Power Analysis in Deep Submicron Electronic Designs

    Directory of Open Access Journals (Sweden)

    May Huang

    2002-01-01

    Full Text Available An empirical algorithm applied to logic level power analysis in deep submicron VLSI designs is introduced in the paper. The method explores a static analysis strategy using unit functions to represent signal transitions. It can be extended to the use of a Register Transfer Level (RTL power analysis after RTL codes are translated to Boolean equations. A new method for representing state-dependent power models is also introduced in the paper to reduce the complexity of power modeling and to improve the performance of power analysis. The modeling method supports not only the empirical power analysis, but also general simulation-based power analysis methods.

  15. Variations in the chemical composition of the submicron aerosol and in the sources of the organic fraction at a regional background site of the Po Valley (Italy)

    Science.gov (United States)

    Bressi, Michael; Cavalli, Fabrizia; Belis, Claudio A.; Putaud, Jean-Philippe; Fröhlich, Roman; Martins dos Santos, Sebastiao; Petralia, Ettore; Prévôt, André S. H.; Berico, Massimo; Malaguti, Antonella; Canonaco, Francesco

    2016-10-01

    Fine particulate matter (PM) levels and resulting impacts on human health are in the Po Valley (Italy) among the highest in Europe. To build effective PM abatement strategies, it is necessary to characterize fine PM chemical composition, sources and atmospheric processes on long timescales (> months), with short time resolution (organic fraction. Although previous studies have been conducted in this region, none of them addressed all these aspects together. For the first time in the Po Valley, we investigate the chemical composition of nonrefractory submicron PM (NR-PM1) with a time resolution of 30 min at the regional background site of Ispra during 1 full year, using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) under the most up-to-date and stringent quality assurance protocol. The identification of the main components of the organic fraction is made using the Multilinear-Engine 2 algorithm implemented within the latest version of the SoFi toolkit. In addition, with the aim of a potential implementation of ACSM measurements in European air quality networks as a replacement of traditional filter-based techniques, parallel multiple offline analyses were carried out to assess the performance of the ACSM in the determination of PM chemical species regulated by air quality directives. The annual NR-PM1 level monitored at the study site (14.2 µg m-3) is among the highest in Europe and is even comparable to levels reported in urban areas like New York City and Tokyo. On the annual basis, submicron particles are primarily composed of organic aerosol (OA, 58 % of NR-PM1). This fraction was apportioned into oxygenated OA (OOA, 66 %), hydrocarbon-like OA (HOA, 11 % of OA) and biomass burning OA (BBOA, 23 %). Among the primary sources of OA, biomass burning (23 %) is thus bigger than fossil fuel combustion (11 %). Significant contributions of aged secondary organic aerosol (OOA) are observed throughout the year. The unexpectedly high degree of oxygenation

  16. Enhancement in electrical conductivity of pastes containing submicron Ag-coated Cu filler with palmitic acid surface modification

    Science.gov (United States)

    Choi, Eun Byeol; Lee, Jong-Hyun

    2017-09-01

    The fabrication and applied use of submicron Ag-coated Cu (Cu@Ag) particles as a filler material for epoxy-based conductive pastes having the advantages of a lower material cost and antioxidation behavior were studied. Submicron Cu@Ag particles were successfully prepared and surface-modified using palmitic acid. Diffuse reflectance infrared Fourier transform spectroscopy and thermogravimetric differential scanning calorimetry results indicated the formation of an organic layer by the chemical interaction between the Cu@Ag surface and palmitic acid and the survival of the organic layer after treatment at 160 °C for 3 h in air. The printed pastes containing both commercial micron Cu@Ag flakes and the fabricated submicron Cu@Ag particles showed a greatly reduced electrical resistivity (4.68 × 10-4 Ω cm) after surface modification compared to an initial value of 1.85 × 10-3 Ω cm when cured.

  17. Airborne studies of submicron aerosol in the troposphere over West Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Panchenko, M.V.; Zuev, V.E.; Belan, B.D.; Terpugova, S.A. [Institute of Atmospheric Optics, Tomsk (Russian Federation)

    1996-04-01

    Submicron fraction particles that have the longest lifespan and are included in almost all atmospheric processes are of special importance among the great variety of sizes of particles present in the atmosphere. Submicron particles mainly determine the opticle state of the atmosphere in the visible spectral range, essentially cause the absorption of infrared radiation and, since they are the products and participants in all aerosol-to-gas transformations, accumulate of a lot of various chemical compounds and transfer them to large distances. Investigation of the processes of the spatial-temporal variability of aerosol particles for different climatic zones of the earth is the experimental base for studying their effect on climatically and ecologically significant factors and estimating their unfavorable tendencies. The increasing anthropogenic loading of the earth`s atmosphere is creating an urgency for aerosol research. Regardless of how perfect the analytical and numerical methods of solving radiation problems may be, success in forecasting climatic change is mainly determined by the reliability of the experimental data on optical parameters of the atmosphere and of the description of their variability under the effect of external factors.

  18. Preparation of superhard cubic boron nitride sintered from commercially available submicron powders

    Science.gov (United States)

    Liu, Teng; Kou, Zili; Lu, Jingrui; Yan, Xiaozhi; Liu, Fangming; Li, Xin; Ding, Wei; Liu, Jin; Zhang, Qiang; Wang, Qiang; Ma, Dejiang; Lei, Li; He, Duanwei

    2017-03-01

    Using submicron cubic boron nitride (cBN) powder as a starting material, polycrystalline cBN (PcBN) samples without additives were sintered from 8.0-14.0 GPa at 1750 °C, and their sintering behaviour and mechanical properties were investigated. Transmission electron microscopy analysis showed that high-density nanotwins could be generated from common submicron cBN grains during high pressure and high temperature treatment. The dislocation glide and (111) mechanical micro-twinning are the main mechanisms that underlie plastic deformation in the sintering process, and this contributes to the grain refinement. A refinement in the grain size (˜120 nm), micro-defect (nanotwin and stacking faults), and strong covalent bonding between the grains are crucial for improving the sample mechanical properties. The PcBN sintered at 11.0 GPa/1750 °C possessed outstanding mechanical properties, including a high Vickers hardness (˜72 GPa), fracture toughness (˜12.4 MPam1/2), and thermal stability (˜1273 °C in air).

  19. Submicron polycaprolactone particles as a carrier for imaging contrast agent for in vitro applications.

    Science.gov (United States)

    Iqbal, Muhammad; Robin, Sophie; Humbert, Philippe; Viennet, Céline; Agusti, Geraldine; Fessi, Hatem; Elaissari, Abdelhamid

    2015-12-01

    Fluorescent materials have recently attracted considerable attention due to their unique properties and high performance as imaging agent in biomedical fields. Different imaging agents have been encapsulated in order to restrict its delivery to a specific area. In this study, a fluorescent contrast agent was encapsulated for in vitro application by polycaprolactone (PCL) polymer. The encapsulation was performed using modified double emulsion solvent evaporation technique with sonication. Fluorescent nanoparticles (20 nm) were incorporated in the inner aqueous phase of double emulsion. A number of samples were fabricated using different concentrations of fluorescent contrast agent. The contrast agent-containing submicron particle was characterized by a zetasizer for average particle size, SEM and TEM for morphology observations and fluorescence spectrophotometer for encapsulation efficiency. Moreover, contrast agent distribution in the PCL matrix was determined by confocal microscopy. The incorporation of contrast agent in different concentrations did not affect the physicochemical properties of PCL particles and the average size of encapsulated particles was found to be in the submicron range. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Optimizing a manufacturing submicron CMOS process for low-voltage applications

    Science.gov (United States)

    Ma, Jun; Cheng, Sunny; Pryor, Bob; Klein, Kevin

    1996-09-01

    A low threshold voltage (Vt) is desired to improve a CMOS circuit performance when operating at reduced supply voltages to save power. In this paper, a practical approach to reduce Vt for a conventional, manufacturing submicron CMOS process is presented. This `evolutionary' approach to reduce Vt is taken so as the ensure manufacturability and to reduce process cost. This is found to be useful especially before a deep-submicron or a sophisticated process targeted for low voltage application becomes available and manufacturable. Vt reduction is achieved by the integration of a thinner, in the case presented here a 105 angstroms, gate oxide into a 0.65 micrometers process. The process is then optimized to provide the device with highest current-drive while obtaining lowest Vt with acceptable subthreshold leakage with conventional front-end and back-end process. It is shown that, with the minimal changes to the 0.65 micrometers conventional manufacturing process, the Vt's for nominal n- and p-channel devices can be reduced by 20% - 30%, with more than 1.5X improvement in current drive at 3.3 V compared to devices with 150 angstroms gate oxide. The enhancement of circuit performance is demonstrated with measurements of benchmark circuits including CPU, ROM, and FSRAM, where successful operation has been obtained near IV and operating frequencies are nearly doubled at supply voltage near 1.6 V compared to conventional 0.65 micrometers process.

  1. Single-Mode Lasers Based on Cesium Lead Halide Perovskite Submicron Spheres.

    Science.gov (United States)

    Tang, Bing; Dong, Hongxing; Sun, Liaoxin; Zheng, Weihao; Wang, Qi; Sun, Fangfang; Jiang, Xiongwei; Pan, Anlian; Zhang, Long

    2017-11-28

    Single-mode laser is realized in a cesium lead halide perovskite submicron sphere at room temperature. All-inorganic cesium lead halide (CsPbX 3 , X = Cl, Br, I) microspheres with tunable sizes (0.2-10 μm) are first fabricated by a dual-source chemical vapor deposition method. Due to smooth surface and regular geometry structure of microspheres, whispering gallery resonant modes make a single-mode laser realized in a submicron sphere. Surprisingly, a single-mode laser with a very narrow line width (∼0.09 nm) was achieved successfully in the CsPbX 3 spherical cavity at low threshold (∼0.42 μJ cm -2 ) with a high cavity quality factor (∼6100), which are the best specifications of lasing modes in all natural nano/microcavities ever reported. By modulating the halide composition and sizes of the microspheres, the wavelength of a single-mode laser can be continuously tuned from red to violet (425-715 nm). This work illustrates that the well-controlled synthesis of metal cesium lead halide perovskite nano/microspheres may offer an alternative route to produce a widely tunable and greatly miniaturized single-mode laser.

  2. Development of eco-friendly submicron emulsions stabilized by a bio-derived gum.

    Science.gov (United States)

    Pérez-Mosqueda, Luis María; Ramírez, Pablo; Trujillo-Cayado, Luis Alfonso; Santos, Jenifer; Muñoz, José

    2014-11-01

    Many traditional organic solvents are being gradually replaced by ecofriendly alternatives. D-Limonene is a terpenic (bio)-solvent that fulfils the requirements to be considered a green solvent. D-Limonene sub-micron emulsions suffer from Ostwald ripening destabilization. In this study, we examined the influence of the addition of a natural gum (rosin gum) to D-limonene in order to prevent Ostwald ripening. This contribution deals with the study of emulsions formulated with a mixture of D-limonene and rosin gum as dispersed phase and Pluronic PE9400 as emulsifier. The procedure followed for the development of these formulations was based on the application of product design principles. This led to the optimum ratio rosin gum/D-limonene and subsequently to the optimum surfactant concentration. The combination of different techniques (rheology, laser diffraction and multiple light scattering) was demonstrated to be a powerful tool to assist in the prediction of the emulsions destabilization process. Not only did the addition of rosin gum highly increase the stability of these emulsions by inhibiting the Ostwald ripening, but it also reduced the emulsions droplet size. Thus, we found that stable sub-micron D-limonene-in-water emulsions have been obtained in the range 3-6 wt% Pluronic PE-9400 by means of a single-step rotor/stator homogenizing process. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Thymol-based submicron emulsions exhibit antifungal activity against Fusarium graminearum and inhibit Fusarium head blight in wheat.

    Science.gov (United States)

    Gill, T A; Li, J; Saenger, M; Scofield, S R

    2016-10-01

    Fusarium graminearum is a very destructive fungal pathogen that leads to Fusarium head blight (FHB) in wheat, a disease which costs growers millions of dollars annually both in crop losses and in remediation efforts. Current countermeasures include the deployment of wheat varieties with some resistance to FHB in conjunction with timed fungicide treatments. In this article, we introduce a fungicide based on thymol, a naturally occurring plant phenolic derived from essential oils. To overcome the hydrophobicity of thymol, the thymol active was incorporated into a low-surfactant submicron emulsion with and without a carrier oil. The minimum fungicidal concentration of F. graminearum was found to be both 0·02% for thymol emulsions with and without an oil component. Time-to-kill experiments showed that thymol emulsions were able to inactivate F. graminearum in as little as 10 s at concentrations above 0·06%. Spraying the thymol emulsions (~0·1% range) on the wheat variety Bobwhite demonstrated significant reductions in FHB infection rate (number of infected spikelets). However, with 0·5% thymol, the wheat heads exhibited premature senescence. Transmission and scanning electron micrographs suggest that the mechanism of antifungal action is membrane mediated, as conidia exposed to thymol showed complete organelle disorganization and evidence of lipid emulsification. The collective experimental data suggest that thymol emulsions may be an effective naturally derived alternative to the current thymol treatments, and chemical fungicides in ameliorating FHB. This is the first thymol-derived nanoemulsion particles resuspended into water and not DMSO, exhibiting the same antibacterial/antifungal activity as previously described thymol and thyme oil treatments. This drastically reduces the environmental footprint thymol will leave if utilized as a fungicide treatment on field crops. © 2016 The Society for Applied Microbiology.

  4. The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaofei; Deane, Grant B.; Moore, Kathryn A.; Ryder, Olivia S.; Stokes, M. Dale; Beall, Charlotte M.; Collins, Douglas B.; Santander, Mitchell V.; Burrows, Susannah M.; Sultana, Camille M.; Prather, Kimberly A.

    2017-06-19

    Covering 71% of the Earth’s surface, oceans represent a significant global source of atmospheric aerosols. The size and composition of sea spray aerosols (SSA) affect their ability to serve as cloud seeds and thus understanding the factors controlling their composition is critical to predicting their impact on clouds and climate. SSA particles have been shown to be an external mixture of particles with different compositions. Film and jet drop production mechanisms ultimately determine the individual particle compositions which are comprised of an array of salt/organic mixtures ranging from pure sea salt to nearly pure organic particles. It is often assumed that the majority of submicron SSA are formed by film drops produced from bursting hydrophobic organic-rich bubble film caps at the sea surface, and in contrast, jet drops are postulated to produce larger supermicron particles from underlying seawater comprised largely of salts and water soluble organic species. However, here we show that jet drops produced by bursting sub-100 m bubbles account for up to 40 % of all submicron particles. They have distinct chemical compositions, organic volume fractions and ice nucleating activities from submicron film drops. Thus a substantial fraction of submicron particles will not necessarily be controlled by the composition of the sea surface microlayer as has been assumed in many studies. This finding has significant ramifications for the size-resolved mixing states of SSA particles which must be taken into consideration when accessing SSA impacts on clouds.

  5. A Nordic project on high speed low power design in sub-micron CMOS technology for mobile phones

    DEFF Research Database (Denmark)

    Olesen, Ole

    This paper is a survey paper presenting the Nordic CONFRONT project and reporting some results from the group at CIE/DTU, Denmark. The objective of the project is to demonstrate the feasibility of sub-micron CMOS for the realisation of RF front-end circuits operating at frequencies in the 1...

  6. Do nanofill or submicron composites show improved smoothness and gloss? A systematic review of in vitro studies

    NARCIS (Netherlands)

    Kaizer, M.R.; Oliveira-Ogliari, A. de; Cenci, M.S.; Opdam, N.J.M.; Moraes, R.R.

    2014-01-01

    OBJECTIVES: Despite nanofill and submicron composites' aim to provide high initial polishing combined with superior smoothness and gloss retention, the question still remains whether clinicians should consider using these new materials over traditional microhybrids. The aim of this paper was to

  7. Submicron InP DHBT technology for high-speed high-swing mixed-signal ICs

    DEFF Research Database (Denmark)

    Godin, Jean; Nodjiadjim, V.; Riet, Muriel

    2008-01-01

    We report on the development of a submicron InP DHBT technology, optimized for the fabrication of 50-GHz-clock mixed signal ICs. In-depth study of device geometry and structure has allowed to get the needed performances and yield. Special attention has been paid to critical thermal behavior. Vari...

  8. Organic solar cells with submicron-thick polymer:fullerene bulk heterojunction films

    Science.gov (United States)

    Lee, Seungsoo; Nam, Sungho; Kim, Hwajeong; Kim, Youngkyoo

    2010-09-01

    We report the viability of organic solar cells with submicron-thick bulk heterojunction films, which were fabricated by mixing poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester at a solid concentration of 90 mg/ml. To elucidate the physics behind the thick film solar cells, optical transmittance and electrical characteristics were compared for film thicknesses between 520 and 1000 nm. Results showed that the device (520 nm thick film; efficiency=3.68%) exhibited similar performance to that of a control device (170 nm thick). A decreasing device performance was measured for much thicker films (efficiency=0.34% for the 1000 nm thick device).

  9. Submicron optical waveguides and microring resonators fabricated by selective oxidation of tantalum.

    Science.gov (United States)

    Rabiei, Payam; Ma, Jichi; Khan, Saeed; Chiles, Jeff; Fathpour, Sasan

    2013-03-25

    Submicron tantalum pentoxide ridge and channel optical waveguides and microring resonators are demonstrated on silicon substrates by selective oxidation of the refractory metal, tantalum. The novel method eliminates the surface roughness problem normally introduced during dry etching of waveguide sidewalls and also simplifies fabrication of directional couplers. It is shown that the measured propagation loss is independent of the waveguide structure and thereby limited by the material loss of tantalum pentoxide in waveguides core regions. The achieved microring resonators have cross-sectional dimensions of ~600 nm × ~500 nm, diameters as small as 80 µm with a quality, Q, factor of 4.5 × 10(4), and a finesse of 120.

  10. The fabrication of integrated carbon pipes with sub-micron diameters

    Science.gov (United States)

    Kim, B. M.; Murray, T.; Bau, H. H.

    2005-08-01

    A method for fabricating integrated carbon pipes (nanopipettes) of sub-micron diameters and tens of microns in length is demonstrated. The carbon pipes are formed from a template consisting of the tip of a pulled alumino-silicate glass capillary coated with carbon deposited from a vapour phase. This method renders carbon nanopipettes without the need for ex situ assembly and facilitates parallel production of multiple carbon-pipe devices. An electric-field-driven transfer of ions in a KCl solution through the integrated carbon pipes exhibits nonlinear current-voltage (I-V) curves, markedly different from the Ohmic I-V curves observed in glass pipettes under similar conditions. The filling of the nanopipette with fluorescent suspension is also demonstrated.

  11. EQUIPMENT FOR NONDESTRUCTIVE TESTING OF SILICON WAFERS SUBMICRON TOPOLOGY DURING THE FABRICATION OF INTEGRATED CIRCUITS

    Directory of Open Access Journals (Sweden)

    S. A. Chizhik

    2013-01-01

    Full Text Available The advantages of using an atomic force microscopy in manufacturing of submicron integrated circuits are described. The possibilities of characterizing the surface morphology and the etching profile for silicon substrate and bus lines, estimation of the periodicity and size of bus lines, geometrical stability for elementary bus line are shown. Methods of optical and atomic force microcopies are combined in one diagnostic unit. Scanning  probe  microscope  (SPM  200  is  designed  and  produced.  Complex  SPM  200  realizes  nondestructive control of microelectronics elements made on silicon wafers up to 200 mm in diameter and it is introduced by JSC «Integral» for the purpose of operational control, metrology and acceptance of the final product.

  12. A 45 nm Stacked CMOS Image Sensor Process Technology for Submicron Pixel.

    Science.gov (United States)

    Takahashi, Seiji; Huang, Yi-Min; Sze, Jhy-Jyi; Wu, Tung-Ting; Guo, Fu-Sheng; Hsu, Wei-Cheng; Tseng, Tung-Hsiung; Liao, King; Kuo, Chin-Chia; Chen, Tzu-Hsiang; Chiang, Wei-Chieh; Chuang, Chun-Hao; Chou, Keng-Yu; Chung, Chi-Hsien; Chou, Kuo-Yu; Tseng, Chien-Hsien; Wang, Chuan-Joung; Yaung, Dun-Nien

    2017-12-05

    A submicron pixel's light and dark performance were studied by experiment and simulation. An advanced node technology incorporated with a stacked CMOS image sensor (CIS) is promising in that it may enhance performance. In this work, we demonstrated a low dark current of 3.2 e-/s at 60 °C, an ultra-low read noise of 0.90 e-·rms, a high full well capacity (FWC) of 4100 e-, and blooming of 0.5% in 0.9 μm pixels with a pixel supply voltage of 2.8 V. In addition, the simulation study result of 0.8 μm pixels is discussed.

  13. Formation of stable submicron peptide or protein particles by thin film freezing

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Keith P.; Engstrom, Joshua; Williams, III, Robert O.

    2017-04-18

    The present invention includes compositions and methods for preparing micron-sized or submicron-sized particles by dissolving a water soluble effective ingredient in one or more solvents; spraying or dripping droplets solvent such that the effective ingredient is exposed to a vapor-liquid interface of less than 50, 100, 150, 200, 250, 200, 400 or 500 cm.sup.-1 area/volume to, e.g., increase protein stability; and contacting the droplet with a freezing surface that has a temperature differential of at least 30.degree. C. between the droplet and the surface, wherein the surface freezes the droplet into a thin film with a thickness of less than 500 micrometers and a surface area to volume between 25 to 500 cm.sup.-1.

  14. Vectors and submicron precision: redundancy and 3D stacking in silicon pixel detectors

    CERN Document Server

    Heijne, E H M; Wong, W; Idarraga, J; Visser, J; Jakubek, J; Leroy, C; Turecek, D; Visschers, J; Pospisil, S; Ballabriga, R; Vykydal, Z; Vermeulen, J; Plackett, R; Heijne, E H M; Llopart, X; Boltje, D; Campbell, M

    2010-01-01

    Measurements are shown of GeV pions and muons in two 300 mu m thick, Si Medipix pixel detector assemblies that are stacked on top of each other, with a 25 mu m thick brass foil in between. In such a radiation imaging semiconductor matrix with a large number of pixels along the particle trail, one can determine local space vectors for the particle trajectory instead of points. This improves pattern recognition and track reconstruction, especially in a crowded environment. Stacking of sensor planes is essential for resolving directional ambiguities. Signal charge sharing can be employed for measuring positions with submicron precision. In the measurements one notices accompanying `delta' electrons that emerge outside the particle trail, far beyond the boundaries of the 55 mu m pixel cells. The frequency of such corrupted position measurements is similar to one per 2.5mm of traversed Si.

  15. Submicron particle mass concentrations and sources in the Amazonian wet season (AMAZE-08)

    Science.gov (United States)

    Chen, Q.; Farmer, D. K.; Rizzo, L. V.; Pauliquevis, T.; Kuwata, M.; Karl, T. G.; Guenther, A.; Allan, J. D.; Coe, H.; Andreae, M. O.; Pöschl, U.; Jimenez, J. L.; Artaxo, P.; Martin, S. T.

    2015-04-01

    Real-time mass spectra of the non-refractory species in submicron aerosol particles were recorded in a tropical rainforest in the central Amazon Basin during the wet season from February to March 2008, as a part of the Amazonian Aerosol Characterization Experiment (AMAZE-08). Organic material accounted on average for more than 80% of the non-refractory submicron particle mass concentrations during the period of measurements. There was insufficient ammonium to neutralize sulfate. In this acidic, isoprene-rich, HO2-dominant environment, positive-matrix factorization of the time series of particle mass spectra identified four statistical factors to account for the 99% of the variance in the signal intensities of the organic constituents. The first factor was identified as associated with regional and local pollution and labeled "HOA" for its hydrocarbon-like characteristics. A second factor was associated with long-range transport and labeled "OOA-1" for its oxygenated characteristics. A third factor, labeled "OOA-2," was implicated as associated with the reactive uptake of isoprene oxidation products, especially of epoxydiols to acidic haze, fog, or cloud droplets. A fourth factor, labeled "OOA-3," was consistent with an association with the fresh production of secondary organic material (SOM) by the mechanism of gas-phase oxidation of biogenic volatile organic precursors followed by gas-to-particle conversion of the oxidation products. The suffixes 1, 2, and 3 on the OOA labels signify ordinal ranking with respect to the extent of oxidation represented by the factor. The process of aqueous-phase oxidation of water-soluble products of gas-phase photochemistry might also have been associated to some extent with the OOA-2 factor. The campaign-average factor loadings had a ratio of 1.4:1 for OOA-2 : OOA-3, suggesting the comparable importance of particle-phase compared to gas-phase pathways for the production of SOM during the study period.

  16. Analysis of major air pollutants and submicron particles in New York City and Long Island

    Science.gov (United States)

    Masiol, M.; Hopke, P. K.; Felton, H. D.; Frank, B. P.; Rattigan, O. V.; Wurth, M. J.; LaDuke, G. H.

    2017-01-01

    A year-long sampling campaign of major air pollutants and submicron particle number size distributions was conducted at two sites taken as representative of city-wide air quality in New York City and Long Island, respectively. A number of species were quantified with hourly time resolution, including particle number concentrations in 6 size ranges (20-30 nm, 30-50 nm, 50-70 nm, 70-100 nm, 100-200 nm, and >200 nm), nitrogen oxides, sulfur dioxide, ozone, carbon monoxide, methane, non-methane hydrocarbons, PM2.5 mass concentration and some PM major components (sulfate, organic and elemental carbon). Hourly concentrations of primary and secondary organic carbon were estimated using the EC tracer method. Data were matched with weather parameters and air parcel back-trajectories. A series of tools were thus applied to: (i) study the seasonal, weekly, diurnal cycles of pollutants; (ii) investigate the relationships amongst pollutants through correlation and lagged correlation analyses; (iii) depict the role of atmospheric photochemical processes; (iv) examine the location of the potential sources by mean of conditional bivariate probability function analysis and (v) investigate the role of regional transport of air masses to the concentrations of analyzed species. Results indicate that concentrations of NOx, SO2, CO, non-methane hydrocarbons, primary OC and EC are predominantly determined by local sources, but are also affected by regional transports of polluted air masses. On the contrary, the transport of continental polluted air masses has a main effect in raising the concentrations of secondary PM2.5 (sulfate and secondary organic carbon). By providing direct information on the concentrations and trends of key pollutants and submicron particle number concentrations, this study finally enables some general considerations about air quality status and atmospheric processes over the New York City metropolitan area.

  17. Submicron particle mass concentrations and sources in the Amazonian wet season (AMAZE-08)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.; Farmer, D. K.; Rizzo, L. V.; Pauliqueivis, T.; Kuwata, Mikinori; Karl, Thomas G.; Guenther, Alex B.; Allan, James D.; Coe, H.; Andreae, M. O.; Poeschl, U.; Jiminez, J. L.; Artaxo, Paulo; Martin, Scot T.

    2015-01-01

    Real-time mass spectra of non-refractory component of submicron aerosol particles were recorded in a tropical rainforest in the central Amazon basin during the wet season of 2008, as a part of the Amazonian Aerosol Characterization Experiment (AMAZE-08). Organic components accounted on average for more than 80% of the non-refractory submicron particle mass concentrations during the period of measurements. Ammonium was present in sufficient quantities to halfway neutralize sulfate. In this acidic, isoprene-dominated, low-NOx environment the high-resolution mass spectra as well as mass closures with ion chromatography measurements did not provide evidence for significant contributions of organosulfate species, at least at concentrations above uncertainty levels. Positive-matrix factorization of the time series of particle mass spectra identified four statistical factors to account for the variance of the signal intensities of the organic constituents: a factor HOA having a hydrocarbon-like signature and identified as regional emissions of primary organic material, a factor OOA-1 associated with fresh production of secondary organic material by a mechanism of BVOC oxidation followed by gas-to-particle conversion, a factor OOA-2 consistent with reactive uptake of isoprene oxidation products, especially epoxydiols by acidic particles, and a factor OOA-3 associated with long range transport and atmospheric aging. The OOA-1, -2, and -3 factors had progressively more oxidized signatures. Diameter-resolved mass spectral markers also suggested enhanced reactive uptake of isoprene oxidation products to the accumulation mode for the OOA-2 factor, and such size partitioning can be indicative of in-cloud process. The campaign-average factor loadings were in a ratio of 1.1:1.0 for the OOA-1 compared to the OOA-2 pathway, suggesting the comparable importance of gas-phase compared to particle-phase (including cloud waters) production pathways of secondary organic material during

  18. Bacterial characterization in ambient submicron particles during severe haze episodes at Ji'nan, China.

    Science.gov (United States)

    Xu, Caihong; Wei, Min; Chen, Jianmin; Wang, Xinfeng; Zhu, Chao; Li, Jiarong; Zheng, Lulu; Sui, Guodong; Li, Weijun; Wang, Wenxing; Zhang, Qingzhu; Mellouki, Abdelwahid

    2017-02-15

    In January 2014, severe haze episodes which sweep across Chinese cities have attracted public concern and interest at home and abroad. In addition to the physicochemical properties of air pollutants, bacteria are thought to be responsible for the spread of respiratory diseases and various allergies. We attempted the bacterial characterization of submicron particles (PM 0.18-0.32 , PM 0.32-0.56 , and PM 0.56-1 ) under severe haze episodes using high-throughput sequencing and real-time quantitative PCR detecting system based on 21 samples collected from January to March 2014 at Ji'nan, China. The high bacterial concentration in PM 0.32-0.56 (7314cells m -3 ), PM 0.18-0.32 (7212cells m -3 ), and PM 0.56-1 (6982cells m -3 ) showed significant negative correlations with SO 2 , NO 2, and O 3 . Under sufficient sequencing depth, 37 phyla, 71 classes, 137 orders, 236 families, and 378 genera were classified, and the bacterial community structure varied significantly in different size fractions. For example, Holophagaceae (Acidobacteria) in PM 0.32-0.56 showed 6-fold higher abundance than that in PM 0.18-0.32 . Moreover, functional categories and bacterial species (Lactococcus piscium, Pseudomonas fragi, Streptococcus agalactiae, and Pseudomonas cichorii) that may potentially be responsible for infections and allergies were also discovered. Source track analysis showed that the ambient bacteria mainly originated from soils, leaf surfaces, and feces. Our results highlighted the importance of airborne microbial communities by understanding the concentration, structure, ecological and health effects, especially those in submicron particles during haze episodes. Copyright © 2016. Published by Elsevier B.V.

  19. Phase transformation and intense 2.7 μm emission from Er3+ doped YF3/YOF submicron-crystals.

    Science.gov (United States)

    Chai, Guanqi; Dong, Guoping; Qiu, Jianrong; Zhang, Qinyuan; Yang, Zhongmin

    2013-01-01

    Yttrium fluoride YF3:Er(3+) and yttrium oxyfluoride YOF:Er(3+) submicron-crystals with mid-infrared fluorescent emissions were synthesized for the first time. The rhombohedral phase YOF submicron-crystals were synthesized by the crystalline phase transformation from pure orthorhombic YF3 submicron-crystals, which were prepared by co-precipitation method. The composition and morphology were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM), which showed that submicron-crystals were quasi-spherical with the particle size of ~400 nm. A novel formation mechanism of YOF submicron-crystals was proposed. Photoluminescence (PL) spectra indicated the 2.7 μm emission of Er(3+) has remarkably enhanced with the increase of Er(3+) doping concentration, and a novel dynamic circulatory energy transfer mechanism was proposed. Fourier transform infrared spectra (FTIR) were used to demonstrate the change of hydroxyl content. These oxyfluoride submicron-crystals provide a new material for nano/submicron-crystals-glass composites, and open a brand new field for the realization of mid-infrared micro/nano-lasers.

  20. Highly transparent poly(glycidyl methacrylate-co-acryloisobutyl POSS) for 100 μm-thick submicron patterns with an aspect ratio over 100.

    Science.gov (United States)

    Kim, Kwanghyun; Yu, Sunyoung; Kim, Sung-Wook; Kim, Taegeon; Kim, Sang-Min; Kang, Se-Young; Han, Seung Min; Jang, Ji-Hyun

    2017-07-18

    This is the first report on the fabrication of defect-free submicron structures with more than 100 μm thickness and an aspect ratio over 100. Highly transparent poly(glycidyl methacrylate-co-acryloisobutyl POSS) (PGP) was synthesized via radical polymerization. The mechanical properties of the PGP submicron structure displayed a Young's modulus of 6.09 GPa and a hardness of 0.16 GPa, 4.2 and 8 times, respectively, than those of SU8 nanopatterns. These enhancements enable the utilization of ultrathick 2D-/3D-submicron structures as an ideal platform for microelectromechanical systems, big data storage systems, energy devices, etc.

  1. Sub-micron and nanoscale feature depth modulates alignment of stromal fibroblasts and corneal epithelial cells in serum-rich and serum-free media.

    Science.gov (United States)

    Fraser, Sarah A; Ting, Yuk-Hong; Mallon, Kelly S; Wendt, Amy E; Murphy, Christopher J; Nealey, Paul F

    2008-09-01

    Topographic features are generally accepted as being capable of modulating cell alignment. Of particular interest is the potential that topographic feature geometry induces cell alignment indirectly through impacting adsorbed proteins from the cell culture medium on the surface of the substrate. However, it has also been reported that micron-scale feature depth significantly impacts the level of alignment of cellular populations on topography, despite being orders of magnitude larger than the average adsorbed protein layer (nm). In order to better determine the impact of biomimetic length scale topography and adsorbed protein interaction on cellular morphology we have systematically investigated the effect of combinations of sub-micron to nanoscale feature depth and lateral pitch on corneal epithelial cell alignment. In addition we have used the unique properties of a serum-free media alternative in direct comparison to serum-rich medium to investigate the role of culture medium protein composition on cellular alignment to topographically patterned surfaces. Our observation that increasing groove depth elicited larger populations of corneal epithelial cells to align regardless of culture medium composition and of cell orientation with respect to the topography, suggests that these cells can sense changes in topographic feature depths independent of adsorbed proteins localized along ridge edges and tops. However, our data also suggests a strong combinatory effect of topography with culture medium composition, and also a cell type dependency in determining the level of cell elongation and alignment to nanoscale topographic features.

  2. Sub-micron and nanoscale feature depth modulates alignment of stromal fibroblasts and corneal epithelial cells in serum-rich and serum-free media

    Science.gov (United States)

    Fraser, Sarah A.; Ting, Yuk-Hong; Mallon, Kelly S.; Wendt, Amy E.; Murphy, Christopher J.; Nealey, Paul F.

    2011-01-01

    Topographic features are generally accepted as being capable of modulating cell alignment. Of particular interest is the potential that topographic feature geometry induces cell alignment indirectly through impacting adsorbed proteins from the cell culture medium on the surface of the substrate. However, it has also been reported that micron-scale feature depth significantly impacts the level of alignment of cellular populations on topography, despite being orders of magnitude larger than the average adsorbed protein layer (nm). In order to better determine the impact of biomimetic length scale topography and adsorbed protein interaction on cellular morphology we have systematically investigated the effect of combinations of sub-micron to nanoscale feature depth and lateral pitch on corneal epithelial cell alignment. In addition we have used the unique properties of a serum-free media alternative in direct comparison to serum-rich medium to investigate the role of culture medium protein composition on cellular alignment to topographically patterned surfaces. Our observation that increasing groove depth elicited larger populations of corneal epithelial cells to align regardless of culture medium composition and of cell orientation with respect to the topography, suggests that these cells can sense changes in topographic feature depths independent of adsorbed proteins localized along ridge edges and tops. However, our data also suggests a strong combinatory effect of topography with culture medium composition, and also a cell type dependency in determining the level of cell elongation and alignment to nanoscale topographic features. PMID:18041718

  3. Scaling of graphene integrated circuits.

    Science.gov (United States)

    Bianchi, Massimiliano; Guerriero, Erica; Fiocco, Marco; Alberti, Ruggero; Polloni, Laura; Behnam, Ashkan; Carrion, Enrique A; Pop, Eric; Sordan, Roman

    2015-05-07

    The influence of transistor size reduction (scaling) on the speed of realistic multi-stage integrated circuits (ICs) represents the main performance metric of a given transistor technology. Despite extensive interest in graphene electronics, scaling efforts have so far focused on individual transistors rather than multi-stage ICs. Here we study the scaling of graphene ICs based on transistors from 3.3 to 0.5 μm gate lengths and with different channel widths, access lengths, and lead thicknesses. The shortest gate delay of 31 ps per stage was obtained in sub-micron graphene ROs oscillating at 4.3 GHz, which is the highest oscillation frequency obtained in any strictly low-dimensional material to date. We also derived the fundamental Johnson limit, showing that scaled graphene ICs could be used at high frequencies in applications with small voltage swing.

  4. Characteristics and sources of submicron aerosols above the urban canopy (260 m) in Beijing, China during 2014 APEC summit

    Science.gov (United States)

    Chen, C.; Sun, Y. L.; Xu, W. Q.; Du, W.; Zhou, L. B.; Han, T. T.; Wang, Q. Q.; Fu, P. Q.; Wang, Z. F.; Gao, Z. Q.; Zhang, Q.; Worsnop, D. R.

    2015-08-01

    The megacity of Beijing has experienced frequent severe fine particle pollution during the last decade. Although the sources and formation mechanisms of aerosol particles have been extensively investigated on the basis of ground measurements, real-time characterization of aerosol particle composition and sources above the urban canopy in Beijing is rare. In this study, we conducted real-time measurements of non-refractory submicron aerosol (NR-PM1) composition at 260 m at the 325 m Beijing Meteorological Tower (BMT) from 10 October to 12 November 2014, by using an aerosol chemical speciation monitor (ACSM) along with synchronous measurements of size-resolved NR-PM1 composition at near ground level using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). The NR-PM1 composition above the urban canopy was dominated by organics (46 %), followed by nitrate (27 %) and sulfate (13 %). The high contribution of nitrate and high NO3-/SO42- mass ratios illustrate an important role of nitrate in particulate matter (PM) pollution during the study period. The organic aerosol (OA) was mainly composed by secondary OA (SOA), accounting for 61 % on an average. Different from that measured at the ground site, primary OA (POA) correlated moderately with SOA, likely suggesting a high contribution from regional transport above the urban canopy. The Asia-Pacific Economic Cooperation (APEC) summit with strict emission controls provides a unique opportunity to study the impacts of emission controls on aerosol chemistry. All aerosol species were shown to have significant decreases of 40-80 % during APEC from those measured before APEC, suggesting that emission controls over regional scales substantially reduced PM levels. However, the bulk aerosol composition was relatively similar before and during APEC as a result of synergetic controls of aerosol precursors such as SO2, NOx, and volatile organic compounds (VOCs). In addition to emission controls, the routine

  5. Characteristics and sources of submicron aerosols above the urban canopy (260 m) in Beijing, China, during the 2014 APEC summit

    Science.gov (United States)

    Chen, C.; Sun, Y. L.; Xu, W. Q.; Du, W.; Zhou, L. B.; Han, T. T.; Wang, Q. Q.; Fu, P. Q.; Wang, Z. F.; Gao, Z. Q.; Zhang, Q.; Worsnop, D. R.

    2015-11-01

    The megacity of Beijing has experienced frequent severe fine particle pollution during the last decade. Although the sources and formation mechanisms of aerosol particles have been extensively investigated on the basis of ground measurements, real-time characterization of aerosol particle composition and sources above the urban canopy in Beijing is rare. In this study, we conducted real-time measurements of non-refractory submicron aerosol (NR-PM1) composition at 260 m at the Beijing 325 m meteorological tower (BMT) from 10 October to 12 November 2014, by using an aerosol chemical speciation monitor (ACSM) along with synchronous measurements of size-resolved NR-PM1 composition near ground level using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The NR-PM1 composition above the urban canopy was dominated by organics (46 %), followed by nitrate (27 %) and sulfate (13 %). The high contribution of nitrate and high NO3- / SO42- mass ratios illustrates an important role of nitrate in particulate matter (PM) pollution during the study period. The organic aerosol (OA) was mainly composed of secondary OA (SOA), accounting for 61 % on an average. Different from that measured at the ground site, primary OA (POA) correlated moderately with SOA, likely suggesting a high contribution from regional transport above the urban canopy. The Asia-Pacific Economic Cooperation (APEC) summit with strict emission controls provides a unique opportunity to study the impacts of emission controls on aerosol chemistry. All aerosol species were shown to have significant decreases of 40-80 % during APEC from those measured before APEC, suggesting that emission controls over regional scales substantially reduced PM levels. However, the bulk aerosol composition was relatively similar before and during APEC as a result of synergetic controls of aerosol precursors. In addition to emission controls, the routine circulations of mountain-valley breezes were also found to play

  6. Fluxes of Submicron Organic Aerosol above London Measured by Eddy Covariance using the Aerodyne HR-ToF-AMS

    Science.gov (United States)

    Phillips, G. J.; di Marco, C. F.; Farmer, D.; Kimmel, J. R.; Jimenez, J. L.; Nemitz, E.

    2009-12-01

    Urban centres are large sources of sub-micron particles. The myriad of emission sources combined with the complex interaction between regional aerosol and the particulate and gaseous photochemistry make for a complex system. It is evident that particulate emissions from cities will affect the regional atmosphere as well as the environment within the urban area. Aerosol particles have been associated with respiratory and cardio-vascular disease and are also linked with the climate through scattering of radiation and indirect effects such as cloud formation. The Aerodyne Aerosol Mass Spectrometer (AMS) provides a powerful tool to elucidate the sources and processing of organic aerosol in the urban atmosphere. Normally this is done through concentration measurements, by statistical analysis of the organic mass spectra, e.g. using Positive Matrix Factorization (PMF). Recently the quadrupole based AMS (Q-AMS) has been used for the micrometeorological measurement of organic aerosol fluxes above several cities, based on high frequency measurements of individual masses (m/z) representative of different organic mass fractions. While providing a major step forward towards quantification of urban organic aerosol emissions and processing, the interpretation of Q-AMS flux data requires assumptions to scale up signals on individual m/z to total organic mass fluxes. In this paper we present chemically-speciated and size-segregated number aerosol fluxes measured using the next generation eddy covariance flux system based on the Aerodyne HR-ToF-AMS, now capable of recording fast-response eddy-covariance time-series of all m/z simultaneously. This allows organic mass fluxes to be calculated more quantitatively and provides 'flux mass spectra' in addition to concentration mass spectra, which produces novel information on the local emission and processing of organic aerosols in the urban environment, while concentration analysis includes the regional background. The measurements were

  7. Water ice and sub-micron ice particles on Tethys and Mimas

    Science.gov (United States)

    Scipioni, Francesca; Nordheim, Tom; Clark, Roger Nelson; D'Aversa, Emiliano; Cruikshank, Dale P.; Tosi, Federico; Schenk, Paul M.; Combe, Jean-Philippe; Dalle Ore, Cristina M.

    2017-10-01

    IntroductionWe present our ongoing work, mapping the variation of the main water ice absorption bands, and the distribution of the sub-micron particles, across Mimas and Tethys’ surfaces using Cassini-VIMS cubes acquired in the IR range (0.8-5.1 μm). We present our results in the form of maps of variation of selected spectral indicators (depth of absorption bands, reflectance peak height, spectral slopes).Data analysisVIMS acquires hyperspectral data in the 0.3-5.1 μm spectral range. We selected VIMS cubes of Tethys and Mimas in the IR range (0.8-5.1 μm). For all pixels in the selected cubes, we measured the band depths for water-ice absorptions at 1.25, 1.5 and 2.02 μm and the height of the 3.6 μm reflection peak. Moreover, we considered the spectral indictors for particles smaller than 1 µm [1]: (i) the 2 µm absorption band is asymmetric and (ii) it has the minimum shifted to longer λ (iii) the band depth ratio 1.5/2.0 µm decreases; (iv) the reflection peak at 2.6 µm decreases; (v) the Fresnel reflection peak is suppressed; (vi) the 5 µm reflectance is decreased relative to the 3.6 µm peak. To characterize the global variation of water-ice band depths, and of sub-micron particles spectral indicators, across Mimas and Tethys, we sampled the two satellites’ surfacees with a 1°x1° fixed-resolution grid and then averaged the band depths and peak values inside each square cell.3. ResultsFor both moons we find that large geologic features, such as the Odysseus and Herschel impact basins, do not correlate with water ice’s abundance variation. For Tethys, we found a quite uniform surface on both hemispheres. The only deviation from this pattern shows up on the trailing hemisphere, where we notice two north-oriented, dark areas around 225° and 315°. For Mimas, the leading and trailing hemispheres appear to be quite similar in water ice abundance, the trailing portion having water ice absorption bands lightly more suppressed than the leading side

  8. Sub-micron resolution high-speed spectral domain optical coherence tomography in quality inspection for printed electronics

    Science.gov (United States)

    Czajkowski, J.; Lauri, J.; Sliz, R.; Fält, P.; Fabritius, T.; Myllylä, R.; Cense, B.

    2012-04-01

    We present the use of sub-micron resolution optical coherence tomography (OCT) in quality inspection for printed electronics. The device used in the study is based on a supercontinuum light source, Michelson interferometer and high-speed spectrometer. The spectrometer in the presented spectral-domain optical coherence tomography setup (SD-OCT) is centered at 600 nm and covers a 400 nm wide spectral region ranging from 400 nm to 800 nm. Spectra were acquired at a continuous rate of 140,000 per second. The full width at half maximum of the point spread function obtained from a Parylene C sample was 0:98 m. In addition to Parylene C layers, the applicability of sub-micron SD-OCT in printed electronics was studied using PET and epoxy covered solar cell, a printed RFID antenna and a screen-printed battery electrode. A commercial SD-OCT system was used for reference measurements.

  9. Fate of Multimeric Oligomers, Submicron, and Micron Size Aggregates of Monoclonal Antibodies Upon Subcutaneous Injection in Mice.

    Science.gov (United States)

    Kijanka, Grzegorz; Bee, Jared S; Bishop, Steven M; Que, Ivo; Löwik, Clemens; Jiskoot, Wim

    2016-05-01

    The aim of this study was to examine the fate of differently sized protein aggregates upon subcutaneous injection in mice. A murine and a human monoclonal immunoglobulin G 1 (IgG1) antibody were labeled with a fluorescent dye and subjected to stress conditions to create aggregates. Aggregates fractionated by centrifugation or gel permeation chromatography were administered subcutaneously into SKH1 mice. The biodistribution was measured by in vivo fluorescence imaging for up to 1 week post injection. At several time points, mice were sacrificed and selected organs and tissues were collected for ex vivo analysis. Part of injected aggregated IgGs persisted much longer at the injection site than unstressed controls. Aggregate fractions containing submicron (0.1-1 μm) or micron (1-100 μm) particles were retained to a similar extent. Highly fluorescent "hot-spots" were detected 24 h post injection in spleens of mice injected with submicron aggregates of murine IgG. Submicron aggregates of human IgG showed higher accumulation in draining lymph nodes 1 h post injection than unstressed controls or micron size aggregates. For both tested proteins, aggregated fractions seemed to be eliminated from circulation more rapidly than monomeric fractions. The biodistribution of monomers isolated from solutions subjected to stress conditions was similar to that of unstressed control. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  10. 77 FR 70176 - Previous Participation Certification

    Science.gov (United States)

    2012-11-23

    ... URBAN DEVELOPMENT Previous Participation Certification AGENCY: Office of the Chief Information Officer... digital submission of all data and certifications is available via HUD's secure Internet systems. However...: Previous Participation Certification. OMB Approval Number: 2502-0118. Form Numbers: HUD-2530 . Description...

  11. Spectral photosensitivity of an organic semiconductor in a submicron metal grating

    Energy Technology Data Exchange (ETDEWEB)

    Blinov, L. M., E-mail: lev39blinov@gmail.com; Lazarev, V. V.; Yudin, S. G.; Palto, S. P. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2016-02-15

    The photoelectric effect in films of the copper phthalocyanine organic semiconductor (α-CuPc) has been experimentally studied for two fundamentally different geometries. A sample in the first, normal geometry is fabricated in the form of a sandwich with an α-CuPc film between a transparent SnO{sub 2} electrode on a substrate and an upper reflecting Al electrode. In the second case of the planar geometry, the semiconductor is deposited on the substrate with a system of submicron chromium interdigital electrodes. It has been found that the effective photoconductivity in the planar geometry is more than two orders of magnitude higher than that in the normal geometry. In addition to the classical model (without excitons), a simple exciton model has been proposed within which a relation has been obtained between the probability of the formation of electron–hole pairs and the characteristic recombination and dissociation times of excitons. An increase in the photoconductivity in the planar geometry has been explained within the exciton model by an increase in the rate of dissociation of excitons into electron–hole pairs owing to acceptor oxygen molecules, which diffuse more efficiently into the film in the case of the planar geometry where the upper electrode is absent.

  12. Modelling size and structure of nanoparticles formed from drying of submicron solution aerosols

    Science.gov (United States)

    Bandyopadhyay, Arpan A.; Pawar, Amol A.; Venkataraman, Chandra; Mehra, Anurag

    2015-01-01

    Drying of submicron solution aerosols, under controlled conditions, has been explored to prepare nanoparticles for drug delivery applications. A computational model of solution drop evaporation is developed to study the evolution of solute gradients inside the drop and predict the size and shell thickness of precipitating nanoparticles. The model considers evaporation as a two-stage process involving droplet shrinkage and shell growth. It was corroborated that droplet evaporation rate controls the solute distribution within a droplet and the resulting particle structure (solid or shell type). At higher gas temperatures, rapid build-up of solute near drop surface from high evaporation rates results in early attainment of critical supersaturation solubility and a steeper solute gradient, which favours formation of larger, shell-type particles. At lower gas temperatures, formation of smaller, solid nanoparticles is indicated. The computed size and shell thickness are in good agreement with experimentally prepared lipid nanoparticles. This study indicates that solid or shell structure of precipitated nanoparticles is strongly affected by evaporation rate, while initial solute concentration in the precursor solution and atomized droplet size affect shell thickness. For the gas temperatures considered, evaporative cooling leads to droplet temperature below the melting point of the lipid solute. Thus, we conclude that control over nanoparticle size and structure, of thermolabile precursor materials suitable for drug delivery, can be achieved by controlling evaporation rates, through selection of aerosol processing conditions.

  13. Low density lipoprotein peptide conjugated submicron emulsions for combating prostate cancer.

    Science.gov (United States)

    Sun, Pengchao; Zhang, Nan; Hua, Haiying; Liang, Qian; Zhang, Xuexiao; Sun, Qian; Zhao, Yongxing

    2017-02-01

    Submicron emulsions (SEs) is an advanced formulation that possesses good biocompatibility, high loading of hydrophobic drugs, and good stability through autoclave sterilization. To enhance tumor targeting and tumor cell uptake, SEs could be modified with positive charge and targeting moieties. In the present study, three formulations were prepared: Docetaxel-loaded SEs (DocSEs), cationic DocSEs (DocCSEs), and low density lipoprotein receptor (LDLR) targeted peptide-RLT (CEKLKEAFRLTRKRGLKLA) modified DocCSEs (RLT-DocCSEs). The optimized RLT-DocCSEs showed a particle size 182.2±10nm, a zeta potential 39.62±2.41mV, and a loading efficiency of Docetaxel (Doc) 98%. RLT-DocCSEs demonstrated sustained release in 96h and was stable for two months at 4°C. Compared to DocSEs and DocCSEs, RLT-DocCSEs caused significantly more PC-3 cell inhibition and cell apoptosis. RLT-DocCSEs also showed more cellular uptake and slower cellular elimination than that of DocSEs and DocCSEs. The present study indicated RLT-DocCSEs could be a potential formulation for injection of anti-cancer therapeutics with increased tumor targeting and anti-tumor efficacy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  14. Pharmacokinetics, tissue distribution and anti-tumor effect of low density lipoprotein peptide conjugated submicron emulsions.

    Science.gov (United States)

    Zhang, Nan; Miao, Jinhong; Sun, Pengchao; Liang, Qian; Hua, Haiying; Xu, Yusheng; Zhao, Yongxing

    2016-08-01

    Docetaxel (Doc) is a potent chemotherapy for cancer but its application is limited by poor water solubility and high risk of side effects. To improve these issues, low density lipoprotein receptor (LDLR) targeted peptide-RLT (CEKLKEAFRLTRKRGLKLA) modified Docetaxel-loaded submicron emulsions (RLT-DocSEs) had been developed. Docetaxel-loaded SEs (DocSEs) and cationic DocSEs (DocCSEs) were also prepared for comparison. To evaluate the tumor-targeting ability and anti-tumor efficacy, DocSEs, DocCSEs, and RLT-DocSEs were administrated intravenously to rats respectively. The pharmacokinetic parameters of three formulations were significantly different. In vivo distribution study was conducted in mice and the results indicated that RLT-DocSEs possessed increased tumor targeting ability than DocSEs and DocCSEs. RLT-DocSEs also resulted in a higher tumor inhibition rate and a better anti-tumor efficacy in mice. All the results suggested that RLT-DocSEs could be a potential formulation for the injection of Doc with enhanced tumor targeting and anti-tumor efficacy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. Cefquinome Controlled Size Submicron Particles Precipitation by SEDS Process Using Annular Gap Nozzle

    Directory of Open Access Journals (Sweden)

    Kefeng Xiao

    2017-01-01

    Full Text Available An annular gap nozzle was applied in solution enhanced dispersion by supercritical fluids (SEDS process to prepare cefquinome controlled size submicron particles so as to enhance their efficacy. Analysis results of orthogonal experiments indicated that the concentration of solution was the primary factor to affect particle sizes in SEDS process, and feeding speed of solution, precipitation pressure, and precipitation temperature ranked second to fourth. Meanwhile, the optimal operating conditions were that solution concentration was 100 mg/mL, feeding speed was 9 mL/min, precipitation pressure was 10 MPa, and precipitation temperature was 316 K. The confirmatory experiment showed that D50 of processed cefquinome particles in optimal operating conditions was 0.73 μm. Moreover, univariate effect analysis showed that the cefquinome particle size increased with the increase of concentration of the solution or precipitation pressure but decreased with the increase of solution feeding speed. When precipitation temperature increased, the cefquinome particle size showed highest point. Moreover, characterization of processed cefquinome particles was analyzed by SEM, FT-IR, and XRD. Analysis results indicated that the surface appearance of processed cefquinome particles was flakes. The chemical structure of processed cefquinome particles was not changed, and the crystallinity of processed cefquinome particles was a little lower than that of raw cefquinome particles.

  16. Synthesis of gelatin nano/submicron particles by binary nonsolvent aided coacervation (BNAC) method.

    Science.gov (United States)

    Patra, Shamayita; Basak, Piyali; Tibarewala, D N

    2016-02-01

    A newly developed modified coacervation method is utilized to synthesize gelatin nano/submicron particles (GN/SPs) as a drug carrier. Binary nonsolvent aided coacervation (BNAC) method is a modified single step coacervation method, which has yielded approximately a threefold lower particle size and higher average yield in terms of weight percentage of around 94% in comparison to the conventional phase separation methods. In this study 0.5% (w/v) gelatin aqueous solution with a binary nonsolvent system of acetone and ethanol was used. Nanoparticle synthesis was optimized with respect to nonsolvent system type and pH. pH7 has resulted a minimum particle size of 55.67 (±43.74) nm in anhydrous medium along with a swollen particle size of 776nm (±38.57) in aqueous medium with a zeta potential of (-16.3±3.51) mV in aqueous medium. Swelling ratio of 13.95 confirms the crosslinked hydrogel nature of the particles. Furthermore, drug loading efficiency of the gelatin particles prepared at 7pH was observed with nitrofurazone as the model drug. Results of drug release study indicate the potential use of GN/SPs as drug loading matrix for wound management such as burn wound management. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Sub-micron Hard X-ray Fluorescence Imaging of Synthetic Elements

    Science.gov (United States)

    Jensen, Mark P.; Aryal, Baikuntha P.; Gorman-Lewis, Drew; Paunesku, Tatjana; Lai, Barry; Vogt, Stefan; Woloschak, Gayle E.

    2013-01-01

    Synchrotron-based X-ray fluorescence microscopy (SXFM) using hard X-rays focused into sub-micron spots is a powerful technique for elemental quantification and mapping, as well as microspectroscopic measurement such as μ-XANES (X-ray absorption near edge structure). We have used SXFM to image and simultaneously quantify the transuranic element plutonium at the L3 or L2 edge as well as lighter biologically essential elements in individual rat pheochromocytoma (PC12) cells after exposure to the long-lived plutonium isotope 242Pu. Elemental maps reveal that plutonium localizes principally in the cytoplasm of the cells and avoids the cell nucleus, which is marked by the highest concentrations of phosphorus and zinc, under the conditions of our experiments. The minimum detection limit under typical acquisition conditions for an average 202 μm2 cell is 1.4 fg Pu/cell or 2.9 × 10−20 moles Pu/μm2, which is similar to the detection limit of K-edge SXFM of transition metals at 10 keV. Copper electron microscopy grids were used to avoid interference from gold X-ray emissions, but traces of strontium present in naturally occurring calcium can still interfere with plutonium detection using its Lα X-ray emission. PMID:22444530

  18. Mechanically Robust, Stretchable Solar Absorbers with Submicron-Thick Multilayer Sheets for Wearable and Energy Applications.

    Science.gov (United States)

    Lee, Hye Jin; Jung, Dae-Han; Kil, Tae-Hyeon; Kim, Sang Hyeon; Lee, Ki-Suk; Baek, Seung-Hyub; Choi, Won Jun; Baik, Jeong Min

    2017-05-31

    A facile method to fabricate a mechanically robust, stretchable solar absorber for stretchable heat generation and an enhanced thermoelectric generator (TEG) is demonstrated. This strategy is very simple: it uses a multilayer film made of titanium and magnesium fluoride optimized by a two-dimensional finite element frequency-domain simulation, followed by the application of mechanical stresses such as bending and stretching to the film. This process produces many microsized sheets with submicron thickness (∼500 nm), showing great adhesion to any substrates such as fabrics and polydimethylsiloxane. It exhibits a quite high light absorption of approximately 85% over a wavelength range of 0.2-4.0 μm. Under 1 sun illumination, the solar absorber on various stretchable substrates increased the substrate temperature to approximately 60 °C, irrespective of various mechanical stresses such as bending, stretching, rubbing, and even washing. The TEG with the absorber on the top surface also showed an enhanced output power of 60%, compared with that without the absorber. With an incident solar radiation flux of 38.3 kW/m 2 , the output power significantly increased to 24 mW/cm 2 because of the increase in the surface temperature to 141 °C.

  19. Chemical compositions, sources and evolution processes of the submicron aerosols in Nanjing, China during wintertime

    Science.gov (United States)

    Wu, Y.; He, Y.; Ge, X.; Wang, J.; Yu, H.; Chen, M.

    2016-12-01

    Elevated atmospheric particulate matter pollution is one of the most significant environmental issues in the Yangtze River Delta (YRD), China. Thus it is important to unravel the characteristics, sources and evolution processes of the ambient aerosols in order to improve the air quality. In this study, we report the real-time monitoring results on submicron aerosol particles (PM1) in suburban Nanjing during wintertime of 2015, using an Aerodyne soot particle aerosol mass spectrometer (SP-AMS). This instrument allows the fast measurement of refractory black carbon simultaneously with other aerosol components. Results show that organics was on average the most abundant species of PM1 (25.9%), but other inorganic species, such as nitrate (23.7%) and sulfate (23.3%) also comprised large mass fractions. As the sampling site is heavily influenced by various sources including industrial, traffic and other anthropogenic emissions, etc., six organic aerosol (OA) factors were identified from Positive matrix factorization (PMF) analysis of the SP-AMS OA mass spectra. These factors include three primary OA factors - a hydrocarbon-like OA, an industry-related OA (IOA) and a cooking OA (COA), and three secondary OA factors, i.e., a local OOA (LSOA), a semi-volatile OOA (SV-OOA) and a low-volatility OOA (LV-OOA). Overall, the primary organic aerosol (POA) (HOA, IOA and COA) dominated the total OA mass. Behaviors and evolution processes of these OA factors will be discussed in combining with the other supporting data.

  20. Immunogenicity Studies of Bivalent Inactivated Virions of EV71/CVA16 Formulated with Submicron Emulsion Systems

    Directory of Open Access Journals (Sweden)

    Chih-Wei Lin

    2014-01-01

    Full Text Available We assessed two strategies for preparing candidate vaccines against hand, foot, and mouth disease (HFMD caused mainly by infections of enterovirus (EV 71 and coxsackievirus (CV A16. We firstly design and optimize the potency of adjuvant combinations of emulsion-based delivery systems, using EV71 candidate vaccine as a model. We then perform immunogenicity studies in mice of EV71/CVA16 antigen combinations formulated with PELC/CpG. A single dose of inactivated EV71 virion (0.2 μg emulsified in submicron particles was found (i to induce potent antigen-specific neutralizing antibody responses and (ii consistently to elicit broad antibody responses against EV71 neutralization epitopes. A single dose immunogenicity study of bivalent activated EV71/CVA16 virion formulated with either Alum or PELC/CpG adjuvant showed that CVA16 antigen failed to elicit CVA16 neutralizing antibody responses and did not affect EV71-specific neutralizing antibody responses. A boosting dose of emulsified EV71/CVA16 bivalent vaccine candidate was found to be necessary to achieve high seroconversion of CVA16-specific neutralizing antibody responses. The current results are important for the design and development of prophylactic vaccines against HFMD and other emerging infectious diseases.

  1. Quantitative cellular uptake of double fluorescent core-shelled model submicronic particles

    Energy Technology Data Exchange (ETDEWEB)

    Leclerc, Lara, E-mail: leclerc@emse.fr [Ecole Nationale Superieure des Mines, CIS-EMSE, LINA (France); Boudard, Delphine [LINA (France); Pourchez, Jeremie; Forest, Valerie [Ecole Nationale Superieure des Mines, CIS-EMSE, LINA (France); Marmuse, Laurence; Louis, Cedric [NANO-H S.A.S (France); Bin, Valerie [LINA (France); Palle, Sabine [Universite Jean Monnet, Centre de Microscopie Confocale Multiphotonique (France); Grosseau, Philippe; Bernache-Assollant, Didier [Ecole Nationale Superieure des Mines, CIS-EMSE, LINA (France); Cottier, Michele [LINA (France)

    2012-11-15

    The relationship between particles' physicochemical parameters, their uptake by cells and their degree of biological toxicity represent a crucial issue, especially for the development of new technologies such as fabrication of micro- and nanoparticles in the promising field of drug delivery systems. This work was aimed at developing a proof-of-concept for a novel model of double fluorescence submicronic particles that could be spotted inside phagolysosomes. Fluorescein isothiocyanate (FITC) particles were synthesized and then conjugated with a fluorescent pHrodo Trade-Mark-Sign probe, red fluorescence of which increases in acidic conditions such as within lysosomes. After validation in acellular conditions by spectral analysis with confocal microscopy and dynamic light scattering, quantification of phagocytosis was conducted on a macrophage cell line in vitro. The biological impact of pHrodo functionalization (cytotoxicity, inflammatory response, and oxidative stress) was also investigated. Results validate the proof-of-concept of double fluorescent particles (FITC + pHrodo), allowing detection of entirely engulfed pHrodo particles (green and red labeling). Moreover incorporation of pHrodo had no major effects on cytotoxicity compared to particles without pHrodo, making them a powerful tool for micro- and nanotechnologies.

  2. Fabrication of micron and submicron gratings by using plasma treatment on the curved polydimethylsiloxane surfaces

    Science.gov (United States)

    Yang, Jiangtao; Tang, Jun; Guo, Hao; Liu, Wenyao; Shen, Chong; Liu, Jun; Qin, Li

    2017-10-01

    Here, a simple and low-cost fabrication strategy to efficiently construct well-ordered micron and submicron gratings on polymeric substrates by oxygen plasma treatment is reported. The Polydimethylsiloxane (PDMS) substrate is prepared on the polyethylene (PET) by spin-coating method, then the curved PDMS-PET substrates are processed in oxygen plasma. After appropriate surface treatment time in plasma the curved substrates are flattened, and well-ordered wrinkling shape gratings are obtained, due to the mechanical buckling instability. It is also demonstrated that changing the curvature radius of PDMS-PET substrates and the time of plasma treatment, the period of the wrinkling patterns and the amplitude of grating also change accordingly. It is found the period of the wrinkling patterns increased with the radius of curvature; while the amplitude decreased with that. It also shows good optical performance in transmittance diffraction testing experiments. Thus the well-ordered grating approach may further develop portable and economical applications and offer a valuable method to fabricate other optical micro strain gauges devices.

  3. 2D light scattering static cytometry for label-free single cell analysis with submicron resolution.

    Science.gov (United States)

    Xie, Linyan; Yang, Yan; Sun, Xuming; Qiao, Xu; Liu, Qiao; Song, Kun; Kong, Beihua; Su, Xuantao

    2015-11-01

    Conventional optical cytometric techniques usually measure fluorescence or scattering signals at fixed angles from flowing cells in a liquid stream. Here we develop a novel cytometer that employs a scanning optical fiber to illuminate single static cells on a glass slide, which requires neither microfluidic fabrication nor flow control. This static cytometric technique measures two dimensional (2D) light scattering patterns via a small numerical aperture (0.25) microscope objective for label-free single cell analysis. Good agreement is obtained between the yeast cell experimental and Mie theory simulated patterns. It is demonstrated that the static cytometer with a microscope objective of a low resolution around 1.30 μm has the potential to perform high resolution analysis on yeast cells with distributed sizes. The capability of the static cytometer for size determination with submicron resolution is validated via measurements on standard microspheres with mean diameters of 3.87 and 4.19 μm. Our 2D light scattering static cytometric technique may provide an easy-to-use, label-free, and flow-free method for single cell diagnostics. © 2015 International Society for Advancement of Cytometry.

  4. Ultrathin oxides for the SCM analysis of sub-micron doping profiles

    Energy Technology Data Exchange (ETDEWEB)

    Ciampolini, Lorenzo; Bertin, F.; Hartmann, J.M.; Rochat, N.; Holliger, Ph.; Laugier, F.; Chabli, A

    2003-09-15

    Attenuated total reflection (ATR) spectroscopy and spectroscopic ellipsometry (SE) have been used to characterize oxides used for the scanning capacitance microscopy (SCM) technique. SCM has been used to study boron and phosphorous doped Si test structures epitaxially grown on (100) Si substrates. SCM samples have one-dimensional (1D) doping profiles with sub-micron features, with staircase-like steps in the unipolar sample and a smoother profile in the bipolar sample, as obtained by secondary ion mass spectrometry (SIMS) profiling. Cross-sectional SCM results obtained on samples oxidized by the standard low-temperature UV-ozone method are presented, discussed and compared to results obtained on cleaved samples oxidized by a simple exposure to air. The results show that the native oxide covering a (110) cleaved section may yield SCM images of sufficient quality, with no contrast reversal on a wide range of doping levels, as well as observed on sections prepared with the UV-ozone technique. However, the long-term stability of the SCM signal on native oxides is poor, and UV-ozone oxidation can be used to recover a valid SCM signal. Realistic ultrathin oxide thickness data obtained by SE on (110) substrates are presented together with ATR results, which confirm the superior quality of UV-ozone oxides with respect to other kinds of oxides.

  5. High energy density supercapacitors from lignin derived submicron activated carbon fibers in aqueous electrolytes

    Science.gov (United States)

    Hu, Sixiao; Zhang, Sanliang; Pan, Ning; Hsieh, You-Lo

    2014-12-01

    Highly porous submicron activated carbon fibers (ACFs) were robustly generated from low sulfonated alkali lignin and fabricated into supercapacitors for capacitive energy storage. The hydrophilic and high specific surface ACFs exhibited large-size nanographites and good electrical conductivity to demonstrate outstanding electrochemical performance. ACFs from KOH activation, in particular, showed very high 344 F g-1 specific capacitance at low 1.8 mg cm-2 mass loading and 10 mV s-1 scan rate in aqueous electrolytes. Even at relatively high scan rate of 50 mV s-1 and mass loading of 10 mg cm-2, a decent specific capacitance of 196 F g-1 and a remarkable areal capacitance of 0.55 F cm-2 was obtained, leading to high energy density of 8.1 Wh kg-1 based on averaged electrodes mass. Furthermore, over 96% capacitance retention rates were achieved after 5000 charge/discharge cycles. Such excellent performance demonstrated great potential of lignin derived carbons for electrical energy storage.

  6. Assessment of intrinsic small signal parameters of submicron SiC MESFETs

    Science.gov (United States)

    Riaz, Mohammad; Ahmed, Muhammad Mansoor; Rafique, Umair; Ahmed, Umer Farooq

    2018-01-01

    In this paper, a technique has been developed to estimate intrinsic small signal parameters of submicron SiC MESFETs, designed for high power microwave applications. In the developed technique, small signal parameters are extracted by involving drain-to-source current, Ids instead of Schottky barrier depletion layer expression. It has been demonstrated that in SiC MESFETs, the depletion layer gets modified due to intense transverse electric field and/or self-heating effects, which are conventionally not taken into account. Thus, assessment of AC small signal parameters by employing depletion layer expression loses its accuracy for devices meant for high power applications. A set of expressions for AC small signal elements has been developed using Ids and its dependence on device biasing has been discussed. The validity of the proposed technique has been demonstrated using experimental data. Dr. Ahmed research interests are in Microelectronics, Microwave and RF Engineering and he has supervised numerous MS and PhD research projects. He authored over 100 research papers in the field of microelectronics. Dr. Ahmed is a fellow of the Institution of Engineering and Technology (IET), UK.; a Chartered Engineer (CEng) from the UK Engineering Council and holds the title of European Engineer (Eur Ing) from the European Federation of National Engineering Association (FEANI), Brussels. He is a life member of PEC (Pak); EDS & MTTS (USA).

  7. Fabrication Techniques for Self-Aligned GaAs-BASED HBTs and Submicron Gate Length FETs

    Science.gov (United States)

    Ren, F.

    Process technologies for self-aligned AlGaAs/GaAs and InGaP/GaAs heterojunction bipolar transistors (HBTs) as well as gate definition and dry etching fabrication schemes for submicron gate length AlGaAs/GaAs-based field effect transistors (FETs) are presented. Multiple energy F+ and H+ ions were used to isolate the active devices for HBTs. The resistance of test wafers at 200° C showed no change over periods of more than 50 days. Highly selective dry and wet etch techniques for InGaP/GaAs and AlGaAs/GaAs material systems were used to uniformly expose heterojunctions. Reliability of the alloyed ohmic contact and feasibility of the nonalloyed ohmic contact metallizations for both p and n type GaAs layers will be discussed. The reproducible gate recess etching is one of the critical steps for AlGaAs/GaAs-based FETs. The etching selectivity, damage, pre- and post-clean procedures were studied in terms of device performance. A simple low temperature SiNx deposition and an etch-back process with optical stepper were used to demonstrate 0.1 µm Y-shape gate feature.

  8. Analysis of local deformation effects in resistive strain sensing of a submicron-thickness AFM cantilever

    Science.gov (United States)

    Adams, Jonathan D.; Schwalb, Christian H.; Winhold, Marcel; Šńukić, Maja; Huth, Michael; Fantner, Georg E.

    2013-05-01

    Incorporating resistive strain-sensing elements into MEMS devices is a long-standing approach for electronic detection of the device deformation. As the need for more sensitivity trends the device dimensions downwards, the size of the strain-sensor may become comparable to the device size, which can have significant impact on the mechanical behaviour of the device. To study this effect, we modelled a submicron-thickness silicon nitride AFM cantilever with strain-sensing element. Using finite element analysis, we calculated the strain in the sensor elements for a deflected cantilever. The sensor element contributes to a local stiffening effect in the device structure which lowers the strain in the sensor. By varying the sensor geometry, we investigated the degree to which this effect impacts the strain. Minimizing the sensor size increases the strain, but the reduction in sensor cross-sectional area increases the resistance and expected sensor noise. The optimal sensor geometry must therefore account for this effect. We used our analysis to optimize geometric variations of nanogranular tunnelling resistor (NTR) strain sensors arranged in a Wheatstone bridge on a silicon nitride AFM cantilever. We varied the dimensions of each sensor element to maintain a constant cross-sectional area but maximize the strain in the sensor element. Through this approach, we expect a 45% increase in strain in the sensor and corresponding 20% increase in the Wheatstone bridge signal. Our results provide an important consideration in the design geometry of resistive strainsensing elements in MEMS devices.

  9. Variations in the chemical composition of the submicron aerosol and in the sources of the organic fraction at a regional background site of the Po Valley (Italy

    Directory of Open Access Journals (Sweden)

    M. Bressi

    2016-10-01

    Full Text Available Fine particulate matter (PM levels and resulting impacts on human health are in the Po Valley (Italy among the highest in Europe. To build effective PM abatement strategies, it is necessary to characterize fine PM chemical composition, sources and atmospheric processes on long timescales (> months, with short time resolution (< day, and with particular emphasis on the predominant organic fraction. Although previous studies have been conducted in this region, none of them addressed all these aspects together. For the first time in the Po Valley, we investigate the chemical composition of nonrefractory submicron PM (NR-PM1 with a time resolution of 30 min at the regional background site of Ispra during 1 full year, using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM under the most up-to-date and stringent quality assurance protocol. The identification of the main components of the organic fraction is made using the Multilinear-Engine 2 algorithm implemented within the latest version of the SoFi toolkit. In addition, with the aim of a potential implementation of ACSM measurements in European air quality networks as a replacement of traditional filter-based techniques, parallel multiple offline analyses were carried out to assess the performance of the ACSM in the determination of PM chemical species regulated by air quality directives. The annual NR-PM1 level monitored at the study site (14.2 µg m−3 is among the highest in Europe and is even comparable to levels reported in urban areas like New York City and Tokyo. On the annual basis, submicron particles are primarily composed of organic aerosol (OA, 58 % of NR-PM1. This fraction was apportioned into oxygenated OA (OOA, 66 %, hydrocarbon-like OA (HOA, 11 % of OA and biomass burning OA (BBOA, 23 %. Among the primary sources of OA, biomass burning (23 % is thus bigger than fossil fuel combustion (11 %. Significant contributions of aged secondary organic aerosol (OOA

  10. Enhanced computational performance of the lattice Boltzmann model for simulating micron- and submicron-size particle flows and non-Newtonian fluid flows

    Science.gov (United States)

    Başağaoğlu, Hakan; Harwell, John R.; Nguyen, Hoa; Succi, Sauro

    2017-04-01

    Significant improvements in the computational performance of the lattice-Boltzmann (LB) model, coded in FORTRAN90, were achieved through application of enhancement techniques. Applied techniques include optimization of array memory layouts, data structure simplification, random number generation outside the simulation thread(s), code parallelization via OpenMP, and intra- and inter-timestep task pipelining. Effectiveness of these optimization techniques was measured on three benchmark problems: (i) transient flow of multiple particles in a Newtonian fluid in a heterogeneous fractured porous domain, (ii) thermal fluctuation of the fluid at the sub-micron scale and the resultant Brownian motion of a particle, and (iii) non-Newtonian fluid flow in a smooth-walled channel. Application of the aforementioned optimization techniques resulted in an average 21 × performance improvement, which could significantly enhance practical uses of the LB models in diverse applications, focusing on the fate and transport of nano-size or micron-size particles in non-Newtonian fluids.

  11. NATO Advanced Study Institute on Improved Methods for Examining the Submicron World

    CERN Document Server

    McGowan, J; Shinozaki, Douglas

    1986-01-01

    An Institute like ours cannot help but lend credence to the notion of the late Derek J. de Solla Price of Yale University that "the scientific revolution was largely the improvement, invention and use of a series of instruments . . . . that expanded the reach of science in innumerable directions". Most of science today and in years gone by depends on the experimental observation of struc­ ture on the small scale with microscopes, and on the large scale with telescopes. The first instruments to expand the observational range of the human eye were simple optical systems, designed in the case of microscopes and telescopes to magnify the image. The big breakthrough in the 17th century was not when Galileo first turned his telescope to the heavens, but when improvements in lens-grinding techniques allowed eyeglass makers to make the first telescope. Early microscopy revealed new and previously unsuspected microstruc­ tures in biological and non-biological materials and thus helped to enlarge on the understanding...

  12. Tenogenic differentiation of human induced pluripotent stem cell-derived mesenchymal stem cells dictated by properties of braided submicron fibrous scaffolds.

    Science.gov (United States)

    Czaplewski, Sarah K; Tsai, Tsung-Lin; Duenwald-Kuehl, Sarah E; Vanderby, Ray; Li, Wan-Ju

    2014-08-01

    Tendon and ligament (T/L) engineering is a growing area of research with potential to address the inadequacies of current T/L defect treatments. Our group previously developed braided submicron fibrous scaffolds (BSMFSs) and demonstrated the viability of BSMFSs for T/L tissue engineering. The objective of this study was to investigate the effect of fiber chemistry and braiding angle on BSMFS mechanical properties and in turn, tenogenic differentiation of human induced pluripotent stem cell-derived mesenchymal stem cells (hiPSC-MSCs) seeded on BSMFSs subjected to cyclic tensile stimulation in the absence of tenogenic medium. By varying fiber chemistry and/or braiding angle, BSMFSs with a range of mechanical properties were produced. We found that fiber chemistry dictated cell adhesion while braiding angle dictated the tissue-specific lineage commitment of hiPSC-MSCs. Scaffolds braided with large angles better supported hiPSC-MSC tenogenic differentiation as evidenced by the production of T/L-associated markers, downregulation of osteogenic markers, and expression of fibroblast-like, spindle cell morphology compared to scaffolds braided with small angles. Our results demonstrate the importance of substrate properties and mechanical stimulation on tenogenic differentiation. These results also demonstrate the versatility of BSMFSs and the potential of hiPSC-MSCs for T/L tissue engineering. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. 3D Online Submicron Scale Observation of Mixed Metal Powder's Microstructure Evolution in High Temperature and Microwave Compound Fields

    Directory of Open Access Journals (Sweden)

    Dan Kang

    2014-01-01

    Full Text Available In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT technique; the spatial resolution was enhanced to 0.37 μm/pixel through the designed equipment and the introduction of excellent reconstruction method for the first time. The process of microstructure evolution during sintering was clearly distinguished from 2D and 3D reconstructed images. Typical sintering parameters such as sintering neck size, porosity, and particle size of the sample were presented for quantitative analysis of the influence on the mechanical properties and the sintering kinetics during microwave sintering. The neck size-time curve was obtained and the neck growth exponent was 7.3, which indicated that surface diffusion was the main diffusion mechanism; the reason was the eddy current loss induced by the external microwave fields providing an additional driving force for mass diffusion on the particle surface. From the reconstructed images and the curve of porosity and average particle size versus temperature, it was believed that the presence of liquid phase aluminum accelerated the densification and particle growth.

  14. 3D online submicron scale observation of mixed metal powder's microstructure evolution in high temperature and microwave compound fields.

    Science.gov (United States)

    Kang, Dan; Xu, Feng; Hu, Xiao-fang; Dong, Bo; Xiao, Yu; Xiao, Ti-qiao

    2014-01-01

    In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT) technique; the spatial resolution was enhanced to 0.37  μm/pixel through the designed equipment and the introduction of excellent reconstruction method for the first time. The process of microstructure evolution during sintering was clearly distinguished from 2D and 3D reconstructed images. Typical sintering parameters such as sintering neck size, porosity, and particle size of the sample were presented for quantitative analysis of the influence on the mechanical properties and the sintering kinetics during microwave sintering. The neck size-time curve was obtained and the neck growth exponent was 7.3, which indicated that surface diffusion was the main diffusion mechanism; the reason was the eddy current loss induced by the external microwave fields providing an additional driving force for mass diffusion on the particle surface. From the reconstructed images and the curve of porosity and average particle size versus temperature, it was believed that the presence of liquid phase aluminum accelerated the densification and particle growth.

  15. Submicron and nano formulations of titanium dioxide and zinc oxide stimulate unique cellular toxicological responses in the green microalga Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Gunawan, Cindy, E-mail: c.gunawan@unsw.edu.au [ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Engineering, The University of New South Wales, Sydney, NSW (Australia); Sirimanoonphan, Aunchisa [ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Engineering, The University of New South Wales, Sydney, NSW (Australia); Teoh, Wey Yang [Clean Energy and Nanotechnology (CLEAN) Laboratory, School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region (Hong Kong); Marquis, Christopher P., E-mail: c.marquis@unsw.edu.au [School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW (Australia); Amal, Rose [ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Engineering, The University of New South Wales, Sydney, NSW (Australia)

    2013-09-15

    Highlights: • Uptake of TiO{sub 2} solids by C. reinhardtii generates ROS as an early stress response. • Submicron and nanoTiO{sub 2} exhibit benign effect on cell proliferation. • Uptake of ZnO solids and leached zinc by C. reinhardtii inhibit the alga growth. • No cellular oxidative stress is detected with submicron and nano ZnO exposure. • The toxicity of particles is not necessarily mediated by cellular oxidative stress. -- Abstract: The work investigates the eco-cytoxicity of submicron and nano TiO{sub 2} and ZnO, arising from the unique interactions of freshwater microalga Chlamydomonas reinhardtii to soluble and undissolved components of the metal oxides. In a freshwater medium, submicron and nano TiO{sub 2} exist as suspended aggregates with no-observable leaching. Submicron and nano ZnO undergo comparable concentration-dependent fractional leaching, and exist as dissolved zinc and aggregates of undissolved ZnO. Cellular internalisation of solid TiO{sub 2} stimulates cellular ROS generation as an early stress response. The cellular redox imbalance was observed for both submicron and nano TiO{sub 2} exposure, despite exhibiting benign effects on the alga proliferation (8-day EC50 > 100 mg TiO{sub 2}/L). Parallel exposure of C. reinhardtii to submicron and nano ZnO saw cellular uptake of both the leached zinc and solid ZnO and resulting in inhibition of the alga growth (8-day EC50 ≥ 0.01 mg ZnO/L). Despite the sensitivity, no zinc-induced cellular ROS generation was detected, even at 100 mg ZnO/L exposure. Taken together, the observations confront the generally accepted paradigm of cellular oxidative stress-mediated cytotoxicity of particles. The knowledge of speciation of particles and the corresponding stimulation of unique cellular responses and cytotoxicity is vital for assessment of the environmental implications of these materials.

  16. X, Ku-band microwave-absorption properties of polyarylene ether nitriles terminated with phthalonitrile/Fe{sub 3}O{sub 4} hybrid submicron spheres

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Lifen, E-mail: 361626614@qq.com; Pu, Zejun; Huang, Xu; Liu, Xiaobo, E-mail: liuxb@uestc.edu.cn

    2014-05-01

    Highlights: • PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid spheres were prepared via one-step solvothermal method. • Polymer compatibility is introduced into inorganic submicron spheres successfully. • PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid submicron spheres possessed good ferrimagnetism. • Control the microwave absorption band of PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid submicron spheres. - Abstract: A novel series of PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid submicron spheres with different additions of PEN-t-Ph have been prepared successfully via solvothermal method, and their structures and morphologies were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometer (EDS), Fourier transform infrared spectrophotometer (FTIR), and scanning electron microscopy (SEM). The results revealed that the crystallinity, dispersity, and size of hybrid submicron spheres can be controlled by altering the addition content of PEN-t-Ph. Magnetization measurement showed that the PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid submicron spheres possessed good ferrimagnetism. The electromagnetic measurement indicated that the resonance peaks of complex permittivity, complex permeability, dielectric loss, and magnetic loss were shifted to the higher frequency as the addition of PEN-t-Ph increased. Moreover, the microwave absorption band was also shifted to higher frequency as the addition of PEN-t-Ph increased. Through this method, the polymer compatibility can be introduced into inorganic submicron spheres, which could provide the inorganic particles with more applications.

  17. Size-Dependent Photodynamic Anticancer Activity of Biocompatible Multifunctional Magnetic Submicron Particles in Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Kyong-Hoon Choi

    2016-09-01

    Full Text Available In this study, newly designed biocompatible multifunctional magnetic submicron particles (CoFe2O4-HPs-FAs of well-defined sizes (60, 133, 245, and 335 nm were fabricated for application as a photosensitizer delivery agent for photodynamic therapy in cancer cells. To provide selective targeting of cancer cells and destruction of cancer cell functionality, basic cobalt ferrite (CoFe2O4 particles were covalently bonded with a photosensitizer (PS, which comprises hematoporphyrin (HP, and folic acid (FA molecules. The magnetic properties of the CoFe2O4 particles were finely adjusted by controlling the size of the primary CoFe2O4 nanograins, and secondary superstructured composite particles were formed by aggregation of the nanograins. The prepared CoFe2O4-HP-FA exhibited high water solubility, good MR-imaging capacity, and biocompatibility without any in vitro cytotoxicity. In particular, our CoFe2O4-HP-FA exhibited remarkable photodynamic anticancer efficiency via induction of apoptotic death in PC-3 prostate cancer cells in a particle size- and concentration-dependent manner. This size-dependent effect was determined by the specific surface area of the particles because the number of HP molecules increased with decreasing size and increasing surface area. These results indicate that our CoFe2O4-HP-FA may be applicable for photodynamic therapy (PDT as a PS delivery material and a therapeutic agent for MR-imaging based PDT owing to their high saturation value for magnetization and superparamagnetism.

  18. A statistical analysis of North East Atlantic (submicron aerosol size distributions

    Directory of Open Access Journals (Sweden)

    M. Dall'Osto

    2011-12-01

    Full Text Available The Global Atmospheric Watch research station at Mace Head (Ireland offers the possibility to sample some of the cleanest air masses being imported into Europe as well as some of the most polluted being exported out of Europe. We present a statistical cluster analysis of the physical characteristics of aerosol size distributions in air ranging from the cleanest to the most polluted for the year 2008. Data coverage achieved was 75% throughout the year. By applying the Hartigan-Wong k-Means method, 12 clusters were identified as systematically occurring. These 12 clusters could be further combined into 4 categories with similar characteristics, namely: coastal nucleation category (occurring 21.3 % of the time, open ocean nucleation category (occurring 32.6% of the time, background clean marine category (occurring 26.1% of the time and anthropogenic category (occurring 20% of the time aerosol size distributions. The coastal nucleation category is characterised by a clear and dominant nucleation mode at sizes less than 10 nm while the open ocean nucleation category is characterised by a dominant Aitken mode between 15 nm and 50 nm. The background clean marine aerosol exhibited a clear bimodality in the sub-micron size distribution, with although it should be noted that either the Aitken mode or the accumulation mode may dominate the number concentration. However, peculiar background clean marine size distributions with coarser accumulation modes are also observed during winter months. By contrast, the continentally-influenced size distributions are generally more monomodal (accumulation, albeit with traces of bimodality. The open ocean category occurs more often during May, June and July, corresponding with the North East (NE Atlantic high biological period. Combined with the relatively high percentage frequency of occurrence (32.6%, this suggests that the marine biota is an important source of new nano aerosol particles in NE Atlantic Air.

  19. Simulation of hurricane response to suppression of warm rain by sub-micron aerosols

    Directory of Open Access Journals (Sweden)

    D. Rosenfeld

    2007-07-01

    Full Text Available The feasibility of hurricane modification was investigated for hurricane Katrina using the Weather Research and Forecasting Model (WRF. The possible impact of seeding of clouds with submicron cloud condensation nuclei (CCN on hurricane structure and intensity as measured by nearly halving of the area covered by hurricane force winds was simulated by "turning–off" warm rain formation in the clouds at Katrina's periphery (where wind speeds were less than 22 m s−1. This simplification of the simulation of aerosol effects is aimed at evaluating the largest possible response. This resulted in the weakening of the hurricane surface winds compared to the "non-seeded" simulated storm during the first 24 h within the entire tropical cyclone (TC area compared to a control simulation without warm rain suppression. Later, the seeding-induced evaporative cooling at the TC periphery led to a shrinking of the eye and hence to some increase in the wind within the small central area of the TC. Yet, the overall strength of the hurricane, as defined by the area covered by hurricane force winds, decreased in response to the suppressed warm rain at the periphery, as measured by a 25% reduction in the radius of hurricane force winds. In a simulation with warm rain suppression throughout the hurricane, the radius of the hurricane force winds was reduced by more than 42%, and although the diameter of the eye shrunk even further the maximum winds weakened. This shows that the main mechanism by which suppressing warm rain weakens the TC is the low level evaporative cooling of the un-precipitated cloud drops and the added cooling due to melting of precipitation that falls from above.

  20. Sub-micron opto-chemical probes for studying living neurons

    Science.gov (United States)

    Hossein-Zadeh, M.; Delgado, J.; Schweizer, F.; Lieberman, R.

    2017-02-01

    We have fabricated sub-micron opto-chemical probes for pH, oxygen and calcium monitoring and demonstrated their application in intracellular and extracellular monitoring of neurons (cortical neuronal cultures and acute hippocampal slices). Using these probes, we have measured extracellular pH in the stratum radiatum of the CA1 region of mouse hippocampus upon stimulation of presynaptic Schaffer collateral axons. Synaptic transmission was monitored using standard electrophysiological techniques. We find that the local pH transiently changes in response to synaptic stimulation. In addition, the geometry of the functionalized region on the probe combined with high sensitivity imaging enables simultaneous monitoring of spatially adjacent but distinct compartments. As proof of concept we impaled cultured neurons with the probe measured calcium and pH inside as well as directly outside of neurons as we changed the pH and calcium concentration in the physiological solution in the perfusion chamber. As such these probes can be used to study the impact of the environment on both cellular and extra-cellular space. Additionally as the chemical properties of the surrounding medium can be controlled and monitored with high precision, these probes enable differential measurement of the target parameter referenced to a stable bath. This approach eliminates the uncertainties associated with non-chemical fluctuations in the fluorescent emission and result in a self-calibrated opto-chemical probe. We have also demonstrated multifunctional probes that are capable of measuring up to three parameters in the extracellular space in brain slices.

  1. Submicron Matrices Embedded in a Polymeric Caplet for Extended Intravaginal Delivery of Zidovudine.

    Science.gov (United States)

    Mashingaidze, Felix; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Maharaj, Vinesh; Buchmann, Eckhart; Pillay, Viness

    2017-11-01

    In this study, an intravaginal delivery system able to deliver an anti-HIV-1 agent for the purpose of potentially reducing HIV-1 transmission acting over an extended duration was successfully formulated. This delivery system was a composite polymeric caplet comprising zidovudine-loaded polyethylene glycol enclatherated pectin-mucin submicron matrices embedded within a poly (D,L-lactide), magnesium stearate, Kollidon® SR, and Carbopol® 974P NF-based polymeric caplet matrix. A three-factor and three-level Box-Behnken statistical design was utilized to optimize the polymeric caplet. The optimized directly compressed composite polymeric caplet hardness was 22.1 ± 0.3 N and the matrix resilience was 62.4 ± 0.6%. The swelling- and diffusion-controlled fractional zidovudine (AZT) release from the optimized caplet was 0.74 ± 0.01 in simulated vaginal fluid (SVF), which increased to 0.81 ± 0.21 in phosphate-buffered saline (PBS) simulating seminal fluid, over 30 days. Caplet matrix swelling was directly related to the percentage Carbopol 974P NF composition. An intravaginal system for AZT delivery was tested in the pig model over 28 days. X-ray analysis depicted delivery system swelling with matrix contrast fading over time as vaginal fluid permeated the matrix core. Plasma, vaginal fluid swab eluates, and tissue AZT concentrations were measured by gradient ultra-performance liquid chromatography (UPLC)-tandem photodiode array detection. Vaginal tissue and vaginal fluid swab eluate AZT concentrations remained above effective levels over 28 days and were higher than plasma AZT concentrations, availing a system with reduced systemic toxicity and more effective inhibition of viral replication at the site of entry.

  2. Physical properties of an oxide photoresist film for submicron pattern lithography

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Donyau [Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, 30076, Taiwan (China); Chang, Chun-Ming [Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, 30076, Taiwan (China); Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei, 10617, Taiwan (China); Chen, Shi-Wei [Nano Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan (China); Yang, Chin-Tien [Nanotechnology Research Center, Industrial Technology Research Institute, Hsinchu, 31040, Taiwan (China); Hsueh, Wen-Jeng [Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei, 10617, Taiwan (China)

    2013-09-02

    The minimum etched pits of 300 nm diameter and the trenches of 300 nm width with a 50 nm depth for both geometries are prepared in the GeSbSn oxide photoresist on the silicon substrates. The lithographic patterns are recorded by direct laser writing, using a 405 nm laser diode and 0.9 numerical aperture media disc mastering system. The developed pit diameters in an inorganic oxide photoresist are smaller than the exposed laser beam spot diameter due to thermal lithography. The crystal structures of the as-sputtered and the annealed powder samples scraped from the sputtered films are examined by X-ray diffractometer. The effect of the heating rate on the crystallization temperatures is evaluated by a differential scanning calorimeter and the crystallization activation energy is determined from Kissinger's plot. The optical and absorption characteristics of the oxides are strongly dependent on the oxygen flow rate during the reactive magnetron sputtering process. The transmittance of the deposited films increases and the absorption decreases with increasing oxygen flow rate, which implies that at high oxygen flow rate, the film resembles dielectric material. The oxygen flow rate during the deposition process is defined within a limited range to obtain the proper extinction coefficient. The working extinction coefficients of the films ranging from 0.5 to 0.8 are applied in this study to achieve the sharp and vertical edge of the etched pits and trenches of 50 nm depth. - Highlights: • A photoresist layer consisting GeSbSnO with submicron patterning for optical device applications. • The thermal, optical properties and crystallization behaviors are reported. • A better working extinction coefficient ranges are decided experimentally. • The ranges define minimum size of the etched marks with smooth boundary. • Thermal lithography concept is introduced to explain experimental results.

  3. Effect of short-term regional traffic restriction on urban submicron particulate pollution.

    Science.gov (United States)

    Zhao, Suping; Yu, Ye

    2017-05-01

    During the 2013 and 2015 Lanzhou International Marathon Events (LIME1 and LIME2), the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To fill the gap in information on the effect of short-period (several hours) traffic control on urban air quality, submicron particle size distributions and meteorological data were measured simultaneously during June 2013 and June 2015 in urban Lanzhou. The number and surface area concentrations of particles in the 100-200nm range declined by 67.2% and 65.0% for LIME1 due to traffic control, while they decreased by 39.2% and 37.1% for LIME2. The impact of traffic restriction on air pollution near the sampling site lagged behind the traffic control period for LIME2. In addition, the effect of traffic restriction on air pollution near the sampling site was dependent on the distance between the relative orientation of the sampling site and traffic-restricted zones, as well as meteorological conditions such as wind direction. The influence of traffic restrictions on the particle concentrations differed for different particle sizes. The size range most affected by traffic restriction was 60-200 and 60-300nm for number and surface area concentrations in the urban environment, respectively, while for the particle volume concentration it was the 100-600nm range. This study will provide a basis for implementation of future urban traffic-induced particulate pollution control measures. Copyright © 2016. Published by Elsevier B.V.

  4. Empowerment perceptions of educational managers from previously ...

    African Journals Online (AJOL)

    The perceptions of educational manag ers from previously disadvantaged primary and high schools in the Nelson Mandela Metropole regarding the issue of empowerment are outlined and the perceptions of educational managers in terms of various aspects of empowerment at different levels reflected. A literature study ...

  5. Knowledge and Previous Contraceptive Use by Pregnant ...

    African Journals Online (AJOL)

    Information obtained included demographic characteristics, knowledge of and previous use of contraception. Results: Respondents displayed a high level of contraceptive knowledge, as 277 (91.7%) were aware of it. The condom and the combined oral pill were the two contraceptive methods most commonly known, by 254 ...

  6. Subsequent pregnancy outcome after previous foetal death

    NARCIS (Netherlands)

    Nijkamp, J. W.; Korteweg, F. J.; Holm, J. P.; Timmer, A.; Erwich, J. J. H. M.; van Pampus, M. G.

    Objective: A history of foetal death is a risk factor for complications and foetal death in subsequent pregnancies as most previous risk factors remain present and an underlying cause of death may recur. The purpose of this study was to evaluate subsequent pregnancy outcome after foetal death and to

  7. Laboratory Grouping Based on Previous Courses.

    Science.gov (United States)

    Doemling, Donald B.; Bowman, Douglas C.

    1981-01-01

    In a five-year study, second-year human physiology students were grouped for laboratory according to previous physiology and laboratory experience. No significant differences in course or board examination performance were found, though correlations were found between predental grade-point averages and grouping. (MSE)

  8. Chemical Mapping of Proterozoic Organic Matter at Sub-Micron Spatial Resolution

    Science.gov (United States)

    Oehler, Dorothy Z.; Robert, Francois; Mostefaoui, Smail; Meibom, Anders; Selo, Madeleine; McKay, David S.

    2006-01-01

    We have used a NanoSIMS ion microprobe to map sub-micron-scale distributions of carbon, nitrogen, sulfur, silicon, and oxygen in organic microfossils and laminae from the approximately 0.85 Ga Bitter Springs Formation of Australia. The data provide clues about the original chemistry of the microfossils, the silicification process, and biosignatures of specific microorganisms and microbial communities. Chemical maps of fossil unicells and filaments reveal distinct wall-and sheath-like structures enriched in C, N and S, consistent with their accepted biological origin. Surprisingly, organic laminae, previously considered to be amorphous, also exhibit filamentous and apparently compressed spheroidal structures defined by strong enrichments in C, N and S. By analogy to data from the well-preserved microfossils, these structures are interpreted as being of biological origin, most likely representing densely packed remnants of microbial mats. Because the preponderance of organic matter in Precambrian sediments is similarly "amorphous," our findings open a large body of generally neglected material to in situ structural, chemical, and isotopic study. Our results also offer new criteria for assessing biogenicity of problematic kerogenous materials and thus can be applied to assessments of poorly preserved or fragmentary organic residues in early Archean sediments and any that might occur in meteorites or other extraterrestrial samples.

  9. Single-crystal and textured polycrystalline Nd2Fe14B flakes with a submicron or nanosize thickness

    Energy Technology Data Exchange (ETDEWEB)

    Cui, BZ; Zheng, LY; Li, WF; Liu, JF; Hadjipanayis, GC

    2012-02-01

    This paper reports on the fabrication, structure and magnetic property optimization of Nd2Fe14B single-crystal and [0 0 1] textured poly-nanocrystalline flakes prepared by surfactant-assisted high-energy ball milling (HEBM). Single-crystal Nd2Fe14B flakes first with micron and then with submicron thicknesses were formed via continuous basal cleavage along the (1 1 0) planes of the irregularly shaped single-crystal microparticles during the early stage of HEBM. With further milling, [0 0 1] textured polycrystalline submicron Nd2Fe14B flakes were formed. Finally, crystallographically anisotropic polycrystalline Nd2Fe14B nanoflakes were formed after milling for 5-6 h. Anisotropic magnetic behavior was found in all of the flake samples. Nd2Fe14B flakes prepared with either oleic acid (OA) or oleylamine (OY) as the surfactant exhibited similar morphology, structure and magnetic properties. Both the addition of some low-melting-point eutectic Nd70Cu30 alloy and an appropriate post-annealing can increase the coercivity of the Nd2Fe14B flakes. The coercivity of Nd2Fe14B nanoflakes with an addition of 16.7 wt.% Nd70Cu30 by milling for 5 h in heptane with 20 wt.% OY increased from 3.7 to 6.8 kOe after annealing at 450 degrees C for 0.5 h. The mechanism for formation and coercivity enhancement of Nd2Fe14B single-crystal and textured poly-nanocrystalline flakes with a submicron or nanosize thickness was discussed. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. Submicron organic aerosol in Tijuana, Mexico, from local and Southern California sources during the CalMex campaign

    Science.gov (United States)

    Takahama, S.; Johnson, A.; Guzman Morales, J.; Russell, L. M.; Duran, R.; Rodriguez, G.; Zheng, J.; Zhang, R.; Toom-Sauntry, D.; Leaitch, W. R.

    2013-05-01

    The CalMex campaign was conducted from May 15 to June 30 of 2010 to study the properties and sources of air pollution in Tijuana, Mexico. In this study, submicron organic aerosol mass (OM) composition measured by Fourier Transform Infrared Spectroscopy (FTIR), Aerosol Chemical Speciation Monitor (ACSM), and X-ray spectromicroscopy are combined with statistical analysis and measurements of other atmospheric constituents. The average (±one standard deviation) OM concentration was 3.3 ± 1.7 μg m-3. A large source of submicron aerosol mass at this location was determined to be vehicular sources, which contributed approximately 40% to the submicron OM; largely during weekday mornings. The O/C ratio estimated from ACSM measurements was 0.64 ± 0.19; diurnal variations in this value and the more oxygenated fraction of OM as determined from Positive Matrix Factorization and classification analyses suggest the high degree of oxygenation originates from aged OM, rather than locally-produced secondary organic aerosol. A large contribution of this oxygenated aerosol to Tijuana from various source classes was observed; some fraction of this aerosol mass may be associated with non-refractory components, such as dust or BC. Backtrajectory simulations using the HYSPLIT model suggest that the mean wind vector consistently originated from the northwest region, over the Pacific Ocean and near the Southern California coast, which suggests that the origin of much of the oxygenated organic aerosol observed in Tijuana (as much as 60% of OM) may have been the Southern California Air Basin. The marine aerosol contribution to OM during the period was on average 23 ± 24%, though its contribution varied over synoptic rather than diurnal timescales. BB aerosol contributed 20 ± 20% of the OM during the campaign period, with notable BB events occurring during several weekend evenings.

  11. Radiation tolerant VLSI circuits in standard deep submicron CMOS technologies for the LHC experiments practical design aspects

    CERN Document Server

    Anelli, G; Delmastro, M; Faccio, F; Floria, S; Giraldo, A; Heijne, Erik H M; Jarron, Pierre; Kloukinas, Kostas C; Marchioro, A; Moreira, P; Snoeys, W

    1999-01-01

    We discuss design issues related to the extensive use of Enclosed Layout Transistors (ELT's) and guard rings in deep submicron CMOS technologies in order to improve radiation tolerance of ASIC's designed for the LHC experiments (the Large Hadron Collider at present under construction at CERN). We present novel aspects related to the use of ELT's: noise measured before and after irradiation up to 100 Mrad (SiO/sub 2/), a model to calculate the W/L ratio and matching properties of these devices. Some conclusions concerning the density and the speed of IC's conceived with this design approach are finally drawn. (16 refs).

  12. A Nordic project on high speed low power design in sub-micron CMOS technology for mobile phones

    DEFF Research Database (Denmark)

    Olesen, Ole

    This paper is a survey paper presenting the Nordic CONFRONT project and reporting some results from the group at CIE/DTU, Denmark. The objective of the project is to demonstrate the feasibility of sub-micron CMOS for the realisation of RF front-end circuits operating at frequencies in the 1.......8-2.0 GHz range. The ultimate goal is a single-chip transceiver, requiring only an external band-pass filter between the chip and the antenna. DECT has been chosen as a comparative standard to compare the new approaches developed in the work as well as to facilitate good knowledge transfer to industry. All...

  13. A simple and wide-range refractive index measuring approach by using a sub-micron grating

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun-Wei; Wu, Chun-Che; Lin, Shih-Chieh [Department of Power Mechanical Engineering, National Tsing Hua University, 101 Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

    2015-04-13

    This paper presents the design and simulation results of a high-precision low-cost refractometer that demonstrates the main advantage of a wide measurement range (1 ≤ n ≤ 2). The proposed design is based on the diffractive properties of sub-micron gratings and Snell's Law. The precision and uncertainty factors of the proposed system were tested and analyzed, revealing that the proposed refractometer demonstrates a wide measurement range with sensitivity of 10{sup −4}.

  14. Transport in arrays of submicron Josephson junctions over a ground plane

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Teressa Rae [Univ. of California, Berkeley, CA (United States)

    1997-12-01

    One-dimensional (1D) and two-dimensional (2D) arrays of Al islands linked by submicron Al/AlxOy/Al tunnel junctions were fabricated on an insulating layer grown on a ground plane. The arrays were cooled to temperatures as low as 20 mK where the Josephson coupling energy EJ of each junction and the charging energy EC of each island were much greater than the thermal energy kBT. The capacitance Cg between each island and the ground plane was much greater than the junction capacitance C. Two classes of arrays were studied. In the first class, the normal state tunneling resistance of the junctions was much larger than the resistance quantum for single electrons, RN>> RQe≡ h/e2 ~ 25.8 kΩ, and the islands were driven normal by an applied magnetic field such that EJ = 0 and the array was in the Coulomb blockade regime. The arrays were made on degenerately-doped Si, thermally oxidized to a thickness of approximately 100 nm. The current-voltage (I - V) characteristics of a 1D and a 2D array were measured and found to display a threshold voltage VT below which little current flows. In the second class of arrays, the normal state tunneling resistance of the junctions was close to the resistance quantum for Cooper pairs, RN≈RQ≡h/4e2≈6.45kΩ, such that EJ/EC≈1. The arrays were made on GaAs/Al0.3Ga0.7As heterostructures with a two-dimensional electron gas approximately 100 nm below the surface. One array displayed superconducting behavior at low temperature. Two arrays displayed insulating behavior at low temperature, and the size of the Coulomb gap increased with increasing Rg.

  15. Two-Dimensional Analysis of Narrow Gate Effects in Micron and Submicron Mosfets

    Science.gov (United States)

    Chung, Shao-Shiun

    characteristics are also developed, based on the 2-D results. It is shown that good agreement is obtained between the model, experimental data and 2-D numerical results. Proposed models of the threshold voltage shift and subthreshold characteristics for submicron MOSFETs also show good agreement between numerical results and modeled results.

  16. Chemical characterization and source apportionment of submicron aerosols measured in Senegal during the 2015 SHADOW campaign

    Directory of Open Access Journals (Sweden)

    L.-H. Rivellini

    2017-09-01

    Full Text Available The present study offers the first chemical characterization of the submicron (PM1 fraction in western Africa at a high time resolution, thanks to collocated measurements of nonrefractory (NR species with an Aerosol Chemical Speciation Monitor (ACSM, black carbon and iron concentrations derived from absorption coefficient measurements with a 7-wavelength Aethalometer, and total PM1 determined by a TEOM-FDMS (tapered element oscillating microbalance–filtered dynamic measurement system for mass closure. The field campaign was carried out over 3 months (March to June 2015 as part of the SHADOW (SaHAran Dust Over West Africa project at a coastal site located in the outskirts of the city of Mbour, Senegal. With an averaged mass concentration of 5.4 µg m−3, levels of NR PM1 in Mbour were 3 to 10 times lower than those generally measured in urban and suburban polluted environments. Nonetheless the first half of the observation period was marked by intense but short pollution events (NR PM1 concentrations higher than 15 µg m−3, sea breeze phenomena and Saharan desert dust outbreaks (PM10 up to 900 µg m−3. During the second half of the campaign, the sampling site was mainly under the influence of marine air masses. The air masses on days under continental and sea breeze influences were dominated by organics (36–40 %, whereas sulfate particles were predominant (40 % for days under oceanic influence. Overall, measurements showed that about three-quarters of the total PM1 were explained by NR PM1, BC (black carbon and Fe (a proxy for dust concentrations, leaving approximately one-quarter for other refractory species. A mean value of 4.6 % for the Fe ∕ PM1 ratio was obtained. Source apportionment of the organic fraction, using positive matrix factorization (PMF, highlighted the impact of local combustion sources, such as traffic and residential activities, which contribute on average to 52 % of the total organic

  17. Enhanced hydrophobicity and volatility of submicron aerosols under severe emission control conditions in Beijing

    Science.gov (United States)

    Wang, Yuying; Zhang, Fang; Li, Zhanqing

    2017-04-01

    A series of strict emission control measures were implemented in Beijing and the surrounding seven provinces to ensure good air quality during the 2015 China Victory Day parade, rendering a unique opportunity to investigate anthropogenic impact of aerosol properties. Submicron aerosol hygroscopicity and volatility were measured during and after the control period using a hygroscopic and volatile tandem differential mobility analyzer (H/V-TDMA) system. Three periods, namely, the control clean period (Clean1), the non-control clean period (Clean2), and the non-control pollution period (Pollution), were selected to study the effect of the emission control measures on aerosol hygroscopicity and volatility. Aerosol particles became more hydrophobic and volatile due to the emission control measures. The hygroscopicity parameter (κ) of 40-200 nm particles decreased by 32.0%-8.5% during the Clean1 period relative to the Clean2 period, while the volatile shrink factor (SF) of 40-300 nm particles decreased by 7.5%-10.5%. The emission controls also changed the diurnal variation patterns of both the probability density function of κ (κ-PDF) and the probability density function of SF (SF-PDF). During Clean1 the κ-PDF showed one nearly-hydrophobic (NH) mode for particles in the nucleation mode, which was likely due to the dramatic reduction in industrial emissions of inorganic trace gases. Compared to the Pollution period, particles observed during the Clean1 and Clean2 periods exhibited a more significant non-volatile (NV) mode throughout the day, suggesting a more externally-mixed state particularly for the 150 nm particles. Aerosol hygroscopicities increased as particle sizes increased, with the greatest increases seen during the Pollution period. Accordingly, the aerosol volatility became weaker (i.e., SF increased) during the Clean1 and Clean2 periods, but no apparent trend was observed during the Pollution period. Based on a correlation analysis of the number fractions

  18. Chemical characterization and source apportionment of submicron aerosols measured in Senegal during the 2015 SHADOW campaign

    Science.gov (United States)

    Rivellini, Laura-Hélèna; Chiapello, Isabelle; Tison, Emmanuel; Fourmentin, Marc; Féron, Anaïs; Diallo, Aboubacry; N'Diaye, Thierno; Goloub, Philippe; Canonaco, Francesco; Prévôt, André Stephan Henry; Riffault, Véronique

    2017-09-01

    The present study offers the first chemical characterization of the submicron (PM1) fraction in western Africa at a high time resolution, thanks to collocated measurements of nonrefractory (NR) species with an Aerosol Chemical Speciation Monitor (ACSM), black carbon and iron concentrations derived from absorption coefficient measurements with a 7-wavelength Aethalometer, and total PM1 determined by a TEOM-FDMS (tapered element oscillating microbalance-filtered dynamic measurement system) for mass closure. The field campaign was carried out over 3 months (March to June 2015) as part of the SHADOW (SaHAran Dust Over West Africa) project at a coastal site located in the outskirts of the city of Mbour, Senegal. With an averaged mass concentration of 5.4 µg m-3, levels of NR PM1 in Mbour were 3 to 10 times lower than those generally measured in urban and suburban polluted environments. Nonetheless the first half of the observation period was marked by intense but short pollution events (NR PM1 concentrations higher than 15 µg m-3), sea breeze phenomena and Saharan desert dust outbreaks (PM10 up to 900 µg m-3). During the second half of the campaign, the sampling site was mainly under the influence of marine air masses. The air masses on days under continental and sea breeze influences were dominated by organics (36-40 %), whereas sulfate particles were predominant (40 %) for days under oceanic influence. Overall, measurements showed that about three-quarters of the total PM1 were explained by NR PM1, BC (black carbon) and Fe (a proxy for dust) concentrations, leaving approximately one-quarter for other refractory species. A mean value of 4.6 % for the Fe / PM1 ratio was obtained. Source apportionment of the organic fraction, using positive matrix factorization (PMF), highlighted the impact of local combustion sources, such as traffic and residential activities, which contribute on average to 52 % of the total organic fraction. A new organic aerosol (OA) source

  19. Chemical characteristics of submicron particles at the central Tibetan Plateau: insights from aerosol mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Xu

    2018-01-01

    Full Text Available Recent studies have revealed a significant influx of anthropogenic aerosol from South Asia to the Himalayas and Tibetan Plateau (TP during pre-monsoon period. In order to characterize the chemical composition, sources, and transport processes of aerosol in this area, we carried out a field study during June 2015 by deploying a suite of online instruments including an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS and a multi-angle absorption photometer (MAAP at Nam Co station (90°57′ E, 30°46′ N; 4730 m a.s.l. at the central of the TP. The measurements were made at a period when the transition from pre-monsoon to monsoon occurred. The average ambient mass concentration of submicron particulate matter (PM1 over the whole campaign was  ∼  2.0 µg m−3, with organics accounting for 68 %, followed by sulfate (15 %, black carbon (8 %, ammonium (7 %, and nitrate (2 %. Relatively higher aerosol mass concentration episodes were observed during the pre-monsoon period, whereas persistently low aerosol concentrations were observed during the monsoon period. However, the chemical composition of aerosol during the higher aerosol concentration episodes in the pre-monsoon season was on a case-by-case basis, depending on the prevailing meteorological conditions and air mass transport routes. Most of the chemical species exhibited significant diurnal variations with higher values occurring during afternoon and lower values during early morning, whereas nitrate peaked during early morning in association with higher relative humidity and lower air temperature. Organic aerosol (OA, with an oxygen-to-carbon ratio (O ∕ C of 0.94, was more oxidized during the pre-monsoon period than during monsoon (average O ∕ C ratio of 0.72, and an average O ∕ C was 0.88 over the entire campaign period, suggesting overall highly oxygenated aerosol in the central TP. Positive matrix factorization of the

  20. The role of adsorbed water on the friction of a layer of submicron particles

    Science.gov (United States)

    Sammis, Charles G.; Lockner, David A.; Reches, Ze’ev

    2011-01-01

    Anomalously low values of friction observed in layers of submicron particles deformed in simple shear at high slip velocities are explained as the consequence of a one nanometer thick layer of water adsorbed on the particles. The observed transition from normal friction with an apparent coefficient near μ = 0.6 at low slip speeds to a coefficient near μ = 0.3 at higher slip speeds is attributed to competition between the time required to extrude the water layer from between neighboring particles in a force chain and the average lifetime of the chain. At low slip speeds the time required for extrusion is less than the average lifetime of a chain so the particles make contact and lock. As slip speed increases, the average lifetime of a chain decreases until it is less than the extrusion time and the particles in a force chain never come into direct contact. If the adsorbed water layer enables the otherwise rough particles to rotate, the coefficient of friction will drop to μ = 0.3, appropriate for rotating spheres. At the highest slip speeds particle temperatures rise above 100°C, the water layer vaporizes, the particles contact and lock, and the coefficient of friction rises to μ = 0.6. The observed onset of weakening at slip speeds near 0.001 m/s is consistent with the measured viscosity of a 1 nm thick layer of adsorbed water, with a minimum particle radius of approximately 20 nm, and with reasonable assumptions about the distribution of force chains guided by experimental observation. The reduction of friction and the range of velocities over which it occurs decrease with increasing normal stress, as predicted by the model. Moreover, the analysis predicts that this high-speed weakening mechanism should operate only for particles with radii smaller than approximately 1 μm. For larger particles the slip speed required for weakening is so large that frictional heating will evaporate the adsorbed water and weakening will not occur.

  1. Number size distributions and seasonality of submicron particles in Europe 2008-2009

    Science.gov (United States)

    Asmi, A.; Wiedensohler, A.; Laj, P.; Fjaeraa, A.-M.; Sellegri, K.; Birmili, W.; Weingartner, E.; Baltensperger, U.; Zdimal, V.; Zikova, N.; Putaud, J.-P.; Marinoni, A.; Tunved, P.; Hansson, H.-C.; Fiebig, M.; Kivekäs, N.; Lihavainen, H.; Asmi, E.; Ulevicius, V.; Aalto, P. P.; Swietlicki, E.; Kristensson, A.; Mihalopoulos, N.; Kalivitis, N.; Kalapov, I.; Kiss, G.; de Leeuw, G.; Henzing, B.; Harrison, R. M.; Beddows, D.; O'Dowd, C.; Jennings, S. G.; Flentje, H.; Weinhold, K.; Meinhardt, F.; Ries, L.; Kulmala, M.

    2011-06-01

    Two years of harmonized aerosol number size distribution data from 24 European field monitoring sites have been analysed. The results give a comprehensive overview of the European near surface aerosol particle number concentrations and number size distributions between 30 and 500 nm of dry particle diameter. Spatial and temporal distribution of aerosols in the particle sizes most important for climate applications are presented. We also analyse the annual, weekly and diurnal cycles of the aerosol number concentrations, provide log-normal fitting parameters for median number size distributions, and give guidance notes for data users. Emphasis is placed on the usability of results within the aerosol modelling community. We also show that the aerosol number concentrations of Aitken and accumulation mode particles (with 100 nm dry diameter as a cut-off between modes) are related, although there is significant variation in the ratios of the modal number concentrations. Different aerosol and station types are distinguished from this data and this methodology has potential for further categorization of stations aerosol number size distribution types. The European submicron aerosol was divided into characteristic types: Central European aerosol, characterized by single mode median size distributions, unimodal number concentration histograms and low variability in CCN-sized aerosol number concentrations; Nordic aerosol with low number concentrations, although showing pronounced seasonal variation of especially Aitken mode particles; Mountain sites (altitude over 1000 m a.s.l.) with a strong seasonal cycle in aerosol number concentrations, high variability, and very low median number concentrations. Southern and Western European regions had fewer stations, which decreases the regional coverage of these results. Aerosol number concentrations over the Britain and Ireland had very high variance and there are indications of mixed air masses from several source regions; the

  2. Sub-micron particle number size distribution characteristics at two urban locations in Leicester

    Science.gov (United States)

    Hama, Sarkawt M. L.; Cordell, Rebecca L.; Kos, Gerard P. A.; Weijers, E. P.; Monks, Paul S.

    2017-09-01

    The particle number size distribution (PNSD) of atmospheric particles not only provides information about sources and atmospheric processing of particles, but also plays an important role in determining regional lung dose. Owing to the importance of PNSD in understanding particulate pollution two short-term campaigns (March-June 2014) measurements of sub-micron PNSD were conducted at two urban background locations in Leicester, UK. At the first site, Leicester Automatic Urban Rural Network (AURN), the mean number concentrations of nucleation, Aitken, accumulation modes, the total particles, equivalent black carbon (eBC) mass concentrations were 2002, 3258, 1576, 6837 # cm-3, 1.7 μg m-3, respectively, and at the second site, Brookfield (BF), were 1455, 2407, 874, 4737 # cm-3, 0.77 μg m-3, respectively. The total particle number was dominated by the nucleation and Aitken modes, with both consisting of 77%, and 81% of total number concentrations at AURN and BF sites, respectively. This behaviour could be attributed to primary emissions (traffic) of ultrafine particles and the temporal evolution of mixing layer. The size distribution at the AURN site shows bimodal distribution at 22 nm with a minor peak at 70 nm. The size distribution at BF site, however, exhibits unimodal distribution at 35 nm. This study has for the first time investigated the effect of Easter holiday on PNSD in UK. The temporal variation of PNSD demonstrated a good degree of correlation with traffic-related pollutants (NOX, and eBC at both sites). The meteorological conditions, also had an impact on the PNSD and eBC at both sites. During the measurement period, the frequency of NPF events was calculated to be 13.3%, and 22.2% at AURN and BF sites, respectively. The average value of formation and growth rates of nucleation mode particles were 1.3, and 1.17 cm-3 s-1 and 7.42, and 5.3 nm h-1 at AURN, and BF sites, respectively. It can suggested that aerosol particles in Leicester originate mainly

  3. Systematic Sub-Micron Na/Ca Banding in Orbulina universa and bilobata

    Science.gov (United States)

    Bonnin, E. A.; Zhu, Z.; Spero, H. J.; Hoenisch, B.; Russell, A. D.; Fehrenbacher, J. S.; Gagnon, A. C.

    2016-02-01

    Mg/Ca ratios in planktic foraminifera are used widely as a proxy for past sea-surface temperatures. However, over the last decade, it has become clear that these ratios are not constant throughout the shell. Instead these ratios vary systematically by several fold between day and night independent of temperature, a phenomenon that has yet to be explained mechanistically. Determining whether elements other than Mg also exhibit sub-micron banding is essential to properly interpret Me/Ca-based paleoproxies and could help constrain the mechanisms causing Me/Ca variability. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS), an isotope mapping technique with a spatial resolution of roughly 200 nm, we discovered systematic Na/Ca banding in individuals of the symbiont-bearing planktic foraminifer Orbulina universa that had been cultured at constant temperature. Using stable-isotope time stamps, we show that this Na/Ca banding varies inversely with Mg/Ca, with high Na/Ca during the day and low Na/Ca at night for most individuals. Using a combination of analytical models and complementary instrumental techniques, we test whether these patterns can be explained by various ion transport processes. In addition to this Na/Ca banding pattern, there is a distinct region of both high Mg/Ca and high Na/Ca at the location of the primary organic membrane. This POM signature may be a useful way to map organic layers in foraminifera, a method we tested in bilobata, a rare morphotype of O. universa that develops a secondary sphere. Mapping Na/Ca and Mg/Ca in bilobata, we show that an additional organic layer is required during secondary sphere growth and that mineralization occurs over both spheres when this additional quasi-chamber forms. Applying ToF-SIMS and our new understanding of Na/Ca heterogeneity to bilobata is a first step towards connecting the extensive geochemical knowledge developed in O. universa to the multi-chambered species used in paleoceanography.

  4. Helicity scalings

    Energy Technology Data Exchange (ETDEWEB)

    Plunian, F [ISTerre, CNRS, Universite Joseph Fourier, Grenoble (France); Lessinnes, T; Carati, D [Physique Statistique et Plasmas, Universite Libre de Bruxelles (Belgium); Stepanov, R, E-mail: Franck.Plunian@ujf-grenoble.fr [Institute of Continuous Media Mechanics of the Russian Academy of Science, Perm (Russian Federation)

    2011-12-22

    Using a helical shell model of turbulence, Chen et al. (2003) showed that both helicity and energy dissipate at the Kolmogorov scale, independently from any helicity input. This is in contradiction with a previous paper by Ditlevsen and Giuliani (2001) in which, using a GOY shell model of turbulence, they found that helicity dissipates at a scale larger than the Kolmogorov scale, and does depend on the helicity input. In a recent paper by Lessinnes et al. (2011), we showed that this discrepancy is due to the fact that in the GOY shell model only one helical mode (+ or -) is present at each scale instead of both modes in the helical shell model. Then, using the GOY model, the near cancellation of the helicity flux between the + and - modes cannot occur at small scales, as it should be in true turbulence. We review the main results with a focus on the numerical procedure needed to obtain accurate statistics.

  5. Submicron Particles during Macro- and Micro-Weldings Procedures in Industrial Indoor Environments and Health Implications for Welding Operators

    Directory of Open Access Journals (Sweden)

    Pasquale Avino

    2015-06-01

    Full Text Available One of the emerging risks in the engineering and electronic industries is the exposure of workers to ultrafine particles during (micro-welding operations, i.e., processes used for joining two metal parts heated locally, which constitute the base metal, with or without addition of another metal which is the filler metal, melted between the edges to be joined. The process is accompanied by formation of metallic fumes arising from the molten metal as well as by the emission of metal fumes of variable composition depending on the alloys welded and fused. The aim of this paper is to investigate the number, concentration and size distribution of submicron particles produced by (micro-welding processes. Particle number size distribution is continuously measured during (micro-welding operations by means of two instruments, i.e., Fast Mobility Particle Sizer and Nanoparticle Surface Area Monitor. The temporal variation of the particle number size distribution across the peaks evidences the strong and fast-evolving contribution of nucleation mode particles: peak values are maintained for less than 10 s. The implication of such contribution on human health is linked to the high deposition efficiency of submicronic particles in the alveolar interstitial region of the human respiratory system, where gas exchange occurs.

  6. Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging

    Directory of Open Access Journals (Sweden)

    Shengtao Lin

    2017-06-01

    Full Text Available We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1 photoacoustic imaging contrast, 2 ultrasound contrast with optical activation, and 3 ultrasound contrast with acoustic activation. This agent, which we name ‘Cy-droplet’, has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a ‘microbubble condensation’ method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ. Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical ‘triggerability’ can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.

  7. High-Q AlAs/GaAs adiabatic micropillar cavities with submicron diameters for cQED experiments

    DEFF Research Database (Denmark)

    Lermer, M.; Gregersen, Niels; Dunzer, F.

    stringent requirements to the design and the processing of the micropillars which show a drastic decrease of the Q factor in the low diameter limit due to sidewall scattering losses and mode mismatch. Indeed, these effects limit the Q factor to ~2,000 in the submicron diameter range for a standard...... microcavity design [1, 2]. To overcome the trade-off between high Q and low Vmode, we designed and implemented a novel adiabatic AlAs/GaAs cavity design (MC1) with 3 taper segments (Fig. 1 (a)) as it was suggested by Zhang et al. for SiO2/TiO2 micropillar cavities [3]. Comparative measurements of the Q factor...... were performed between a standard one-λ microcavity structure (MC2) and MC1 for pillars with diameters ranging from 0.70 μm to 1.50 μm (Fig. 1 (b; bottom)). As can be seen in Fig. 1(b) MC1 shows significantly higher Q-factors exceeding 10.000 in the submicron diameter range due to the adiabatic cavity...

  8. A Novel Inlet System for On-line Chemical Analysis of Semi-Volatile Submicron Particulate Matter

    Science.gov (United States)

    Wisthaler, A.; Eichler, P.; Müller, M.; D'anna, B.

    2014-12-01

    We herein present the concept of a novel modular inlet system that allows using gas-phase analyzers for on-line chemical characterization of semi-volatile submicron particles. The "Chemical analysis of aerosol on-line" (CHARON) inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle enrichment in the sampling flow and a thermo-desorption unit for particle volatilization prior to chemical analysis. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) which quantitatively detects most organic analytes and ammonia. The combined set-up measures submicron organic and ammonium nitrate/sulfate particles online. Proof-of-principle studies were carried out for demonstrating the analytical power of the new set-up in analyzing primarily emitted and secondarily generated particles. A promising future application is the study of the partitioning of organic compounds between the gas and the particulate phase.

  9. Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging.

    Science.gov (United States)

    Lin, Shengtao; Shah, Anant; Hernández-Gil, Javier; Stanziola, Antonio; Harriss, Bethany I; Matsunaga, Terry O; Long, Nicholas; Bamber, Jeffrey; Tang, Meng-Xing

    2017-06-01

    We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1) photoacoustic imaging contrast, 2) ultrasound contrast with optical activation, and 3) ultrasound contrast with acoustic activation. This agent, which we name 'Cy-droplet', has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a 'microbubble condensation' method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ . Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical 'triggerability' can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.

  10. X-ray imaging with sub-micron resolution using large-area photon counting detectors Timepix

    Science.gov (United States)

    Dudak, J.; Karch, J.; Holcova, K.; Zemlicka, J.

    2017-12-01

    As X-ray micro-CT became a popular tool for scientific purposes a number of commercially available CT systems have emerged on the market. Micro-CT systems have, therefore, become widely accessible and the number of research laboratories using them constantly increases. However, even when CT scans with spatial resolution of several micrometers can be performed routinely, data acquisition with sub-micron precision remains a complicated task. Issues come mostly from prolongation of the scan time inevitably connected with the use of nano-focus X-ray sources. Long exposure time increases the noise level in the CT projections. Furthermore, considering the sub-micron resolution even effects like source-spot drift, rotation stage wobble or thermal expansion become significant and can negatively affect the data. The use of dark-current free photon counting detectors as X-ray cameras for such applications can limit the issue of increased image noise in the data, however the mechanical stability of the whole system still remains a problem and has to be considered. In this work we evaluate the performance of a micro-CT system equipped with nano-focus X-ray tube and a large area photon counting detector Timepix for scans with effective pixel size bellow one micrometer.

  11. Books average previous decade of economic misery.

    Science.gov (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  12. Induced vaginal birth after previous caesarean section

    Directory of Open Access Journals (Sweden)

    Akylbek Tussupkaliyev

    2016-11-01

    Full Text Available Introduction The rate of operative birth by Caesarean section is constantly rising. In Kazakhstan, it reaches 27 per cent. Research data confirm that the percentage of successful vaginal births after previous Caesarean section is 50–70 per cent. How safe the induction of vaginal birth after Caesarean (VBAC remains unclear. Methodology The studied techniques of labour induction were amniotomy of the foetal bladder with the vulsellum ramus, intravaginal administration of E1 prostaglandin (Misoprostol, and intravenous infusion of Oxytocin-Richter. The assessment of rediness of parturient canals was conducted by Bishop’s score; the labour course was assessed by a partogram. The effectiveness of labour induction techniques was assessed by the number of administered doses, the time of onset of regular labour, the course of labour and the postpartum period and the presence of complications, and the course of the early neonatal period, which implied the assessment of the child’s condition, described in the newborn development record. The foetus was assessed by medical ultrasound and antenatal and intranatal cardiotocography (CTG. Obtained results were analysed with SAS statistical processing software. Results The overall percentage of successful births with intravaginal administration of Misoprostol was 93 per cent (83 of cases. This percentage was higher than in the amniotomy group (relative risk (RR 11.7 and was similar to the oxytocin group (RR 0.83. Amniotomy was effective in 54 per cent (39 of cases, when it induced regular labour. Intravenous oxytocin infusion was effective in 94 per cent (89 of cases. This percentage was higher than that with amniotomy (RR 12.5. Conclusions The success of vaginal delivery after previous Caesarean section can be achieved in almost 70 per cent of cases. At that, labour induction does not decrease this indicator and remains within population boundaries.

  13. Characteristics of submicron particulate matter at the urban roadside in downtown Hong Kong—Overview of 4 months of continuous high-resolution aerosol mass spectrometer measurements

    Science.gov (United States)

    Lee, Berto P.; Li, Yong Jie; Yu, Jian Zhen; Louie, Peter K. K.; Chan, Chak K.

    2015-07-01

    Hong Kong, one of the world's most densely populated cities and an international financial center, has been suffering from traffic-related air pollution. This study presents the first real-time high-resolution aerosol mass spectrometry measurements of submicron nonrefractory particulate matter (NR-PM1) at the urban roadside in Hong Kong from March to July 2013 with the aim to identify major sources, to assess local and nonlocal emissions, and to characterize trends at different time scales. Organics were dominant, with fresh primary organic aerosol representing two thirds of the total measured organics. Cooking contributions in organic aerosol were assessed directly for the first time in Hong Kong and exceeded those related to vehicles although traffic was still the major PM1 source when elemental carbon was included. These findings were supported by additional measurements including traffic data, elemental/organic carbon, and VOC data. Springtime concentrations were about double of those in summer, due to a strong seasonal transition which affected meteorological conditions and street-level circulation. Local formation of secondary species was not clearly discernible in either season. The elemental composition of organic aerosol remained stable with similar elemental ratios across the covered seasons: OM/OC: 1.49 ± 0.13, O/C: 0.25 ± 0.10, H/C: 1.68 ± 0.08 for spring and OM/OC: 1.43 ± 0.14, O/C: 0.21 ± 0.11, H/C: 1.69 ± 0.08 for summer. Diurnal changes in H/C and O/C as a result of mixing of primary organic aerosol and secondary organic aerosol were evident in the van Krevelen plot.

  14. Hygroscopicity of Chemically Aged, sub-micron Squalane Particles: On the Role of Size and Composition towards the Hygroscopicity Parameter κ

    Science.gov (United States)

    Harmon, C. W.; Smith, J. D.; Che, D. L.; Leone, S. R.; Wilson, K. R.

    2010-12-01

    Measurements presented herein explore cloud condensation nuclei (CCN) activity of sub-micron squalane particles chemically aged by hydroxyl radicals as a function of size and OH exposure. As squalane particles are exposed to OH radicals, size-selected 100, 150, and 200 nm particles monotically decrease in size with increasing OH exposure. Concurrently, their CCN derived hygroscopicity parameter values, κ, increase with OH exposure until saturating at 0.165 in the 100 nm data set, 0.140 in the 150 nm data set, and reach a maximum value of 0.075 in the 200 nm data set at the highest level of OH exposure. The critical super-saturation relative humidity (RH) at which CCN activity is achieved decreases initially with increasing OH exposure and then increases with OH exposure, most notably for the 100 nm data set and weakly with the 150 nm data set. Chemically aged squalane particles from the 200 nm data set show a monotonic decrease in critical super-saturation RH with all values of increasing OH exposure between 0.1-2.5 × 10^13 s molec./cc. The measured O:C ratios of 160 nm chemically aged squalane particles, which were reported previously, are compared to κ values by the CCN derived relationship reported in literature: κ = 0.30*O:C and reasonable agreement is attained in the size-selected 150 nm data set. These values are also compared with the hygroscopic growth factor derived relationship in literature: κ = 0.49*(O:C -0.25) and reasonable agreement is attained at O:C > 0.35.

  15. Surgery of intracranial aneurysms previously treated endovascularly.

    Science.gov (United States)

    Tirakotai, Wuttipong; Sure, Ulrich; Yin, Yuhua; Benes, Ludwig; Schulte, Dirk Michael; Bien, Siegfried; Bertalanffy, Helmut

    2007-11-01

    To perform a retrospective study on the patients who underwent aneurysmal surgery following endovascular treatment. We performed a retrospective study on eight patients who underwent aneurysmal surgery following endovascular treatment (-attempts) with gugliemi detachable coils (GDCs). The indications for surgery, surgical techniques and clinical outcomes were analyzed. The indications for surgical treatment after GDC coiling of aneurysm were classified into three groups. First group: surgery of incompletely coiled aneurysms (n=4). Second group: surgery of mass effect on the neural structures due to coil compaction or rebleeding (n=2). Third group: surgery of vascular complications after endovascular procedure due to parent artery occlusion or thrombus propagation from aneurysm (n=2). Aneurysm obliterations could be performed in all cases confirmed by postoperative angiography. Six patients had an excellent outcome and returned to their profession. Patient's visual acuity was improved. One individual experienced right hemiparesis (grade IV/V) and hemihypesthesia. Microsurgical clipping is rarely necessary for previously coiled aneurysms. Surgical treatment is uncommonly required when an acute complication arises during endovascular treatment, or when there is a dynamic change of a residual aneurysm configuration over time that is considered to be insecure.

  16. Cathepsin K-targeted sub-micron particles for regenerative repair of vascular elastic matrix.

    Science.gov (United States)

    Jennewine, Brenton; Fox, Jonathan; Ramamurthi, Anand

    2017-04-01

    Abdominal Aortic Aneurysms (AAA) involve slow dilation and weakening of the aortic wall due to breakdown of structural matrix components, such as elastic fibers by chronically overexpressed matrix metalloproteinases (MMPs), primarily, MMPs-2 and -9. Auto-regenerative repair of disrupted elastic fibers by smooth muscle cells (SMCs) at the AAA site is intrinsically poor and together with chronic proteolysis prevents restoration of elastin homeostasis, necessary to enable AAA growth arrest or regression to a healthy state. Oral doxycycline (DOX) therapy can inhibit MMPs to slow AAA growth, but has systemwide side-effects and inhibits new elastin deposition within AAA tissue, diminishing prospects for restoring elastin homeostasis preventing the arrest/regression of AAA growth. We have thus developed cationic amphiphile (DMAB)-modified submicron particles (SMPs) that uniquely exhibit pro-elastogenic and anti-proteolytic properties, separate from similar effects of the encapsulated drug. These SMPs can enable sustained, low dose DOX delivery within AAA tissue to augment elastin regenerative repair. To provide greater specificity of SMP targeting, we have conjugated the DOX-SMP surface with an antibody against cathepsin K, a lysosomal protease that is highly overexpressed within AAA tissue. We have determined conditions for efficient cathepsin K Ab conjugation onto the SMPs, improved SMP binding to aneurysmal SMCs in culture and to injured vessel walls ex vivo, conjugation did not affect DOX release from the SMPs, and improved pro-elastogenic and anti-proteolytic effects due to the SMPs likely due to their increased proximity to cells via binding. Our study results suggest that cathepsin K Ab conjugation is a useful targeting modality for our pro-regenerative SMPs. Future studies will investigate SMP retention and biodistribution following targeting to induced AAAs in rat models through intravenous or catheter-based aortal infusion and thereafter their efficacy for

  17. Volatility measurement of atmospheric submicron aerosols in an urban atmosphere in southern China

    Directory of Open Access Journals (Sweden)

    L.-M. Cao

    2018-02-01

    Full Text Available Aerosol pollution has been a very serious environmental problem in China for many years. The volatility of aerosols can affect the distribution of compounds in the gas and aerosol phases, the atmospheric fates of the corresponding components, and the measurement of the concentration of aerosols. Compared to the characterization of chemical composition, few studies have focused on the volatility of aerosols in China. In this study, a thermodenuder aerosol mass spectrometer (TD-AMS system was deployed to study the volatility of non-refractory submicron particulate matter (PM1 species during winter in Shenzhen. To our knowledge, this paper is the first report of the volatilities of aerosol chemical components based on a TD-AMS system in China. The average PM1 mass concentration during the experiment was 42.7±20.1 µg m−3, with organic aerosol (OA being the most abundant component (43.2 % of the total mass. The volatility of chemical species measured by the AMS varied, with nitrate showing the highest volatility, with a mass fraction remaining (MFR of 0.57 at 50 °C. Organics showed semi-volatile characteristics (the MFR was 0.88 at 50 °C, and the volatility had a relatively linear correlation with the TD temperature (from the ambient temperature to 200 °C, with an evaporation rate of 0.45 % °C−1. Five subtypes of OA were resolved from total OA using positive matrix factorization (PMF for data obtained under both ambient temperature and high temperatures through the TD, including a hydrocarbon-like OA (HOA, accounting for 13.5 %, a cooking OA (COA, 20.6 %, a biomass-burning OA (BBOA, 8.9 %, and two oxygenated OAs (OOAs: a less-oxidized OOA (LO-OOA, 39.1 % and a more-oxidized OOA (MO-OOA, 17.9 %. Different OA factors presented different volatilities, and the volatility sequence of the OA factors at 50 °C was HOA (MFR of 0.56  >  LO-OOA (0.70  >  COA (0.85  ≈  BBOA (0.87

  18. Evidence of Ostwald ripening during evolution of micro-scale solid carbon spheres.

    Science.gov (United States)

    Ham, Heon; Park, No-Hyung; Kim, Sang Sub; Kim, Hyoun Woo

    2014-01-06

    Ostwald ripening is an evolutionary mechanism that results in micro-scale carbon spheres from nano-scale spheres. Vapor-phase carbon elements from small carbon nanoparticles are transported to the surface of submicron-scale carbon spheres, eventually leading to their evolution to micro-scale spheres via well-known growth mechanisms, including the layer-by-layer, island, and mixed growth modes. The results obtained from this work will pave the way to the disclosure of the evolutionary mechanism of micro-scale carbon spheres and open a new avenue for practical applications.

  19. In-vivo pharmacokinetics, tissue distribution and anti-tumour effect of hydroxycamptothecin delivered in oil-in-water submicron emulsions.

    Science.gov (United States)

    Zhao, Yong-Xing; Liu, Dan-Xing; Liang, Wen-Quan; Ye, Zhi-Wei

    2012-06-01

    The aim of this study was to investigate the pharmacokinetics, tissue distribution and anti-tumour effect of hydroxycamptothecin submicron emulsions (HCPT-SEs). HCPT-SEs or HCPT injection (HCPT-I) was administered intravenously into the tail vein of rats or S180 tumour-bearing mice.   HCPT-SEs increased the plasma concentration of HCPT compared with HCPT-I at all time points. The AUC(0-∞) , elimination half-life and mean residence time of anionic submicron emulsions containing HCPT (HCPT-ASEs) and cationic submicron emulsions containing HCPT (HCPT-CSEs) were significantly greater than those of HCPT-I (P  anti-tumour effect studies showed that HCPT-SEs improved the therapeutic efficiency of HCPT compared with HCPT-I. The percentage of tumour growth suppression rate of mice treated with HCPT-CSEs (2.0 mg HCPT eq./kg) increased 2.1 fold compared with that of HCPT-I. Submicron emulsions can alter the pharmacokinetic characteristics and tissue distribution of HCPT, and enhance tumour targeting and anti-tumour activity. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

  20. Investigation of the enhanced spatial density of submicron lunar ejecta between L values 1.2 and 3.0 in the earth's magnetosphere: Theory

    Science.gov (United States)

    Alexander, W. M.; Tanner, W. G.; Goad, H. S.

    1987-01-01

    Initial results from the measurement conducted by the dust particle experiment on the lunar orbiting satellite Lunar Explorer 35 (LE 35) were reported with the data interpreted as indicating that the moon is a significant source of micrometeroids. Primary sporadic and stream meteoroids impacting the surface of the moon at hypervelocity was proposed as the source of micron and submicron particles that leave the lunar craters with velocities sufficient to escape the moon's gravitational sphere of influence. No enhanced flux of lunar ejecta with masses greater than a nanogram was detected by LE 35 or the Lunar Orbiters. Hypervelocity meteoroid simulation experiments concentrating on ejecta production combined with extensive analyses of the orbital dynamics of micron and submicron lunar ejecta in selenocentric, cislunar, and geocentric space have shown that a pulse of these lunar ejecta, with a time correlation relative to the position of the moon relative to the earth, intercepts the earth's magnetopause surface (EMPs). As shown, a strong reason exists for expecting a significant enhancement of submicron dust particles in the region of the magnetosphere between L values of 1.2 and 3.0. This is the basis for the proposal of a series of experiments to investigate the enhancement or even trapping of submicron lunar ejecta in this region. The subsequent interaction of this mass with the upper-lower atmosphere of the earth and possible geophysical effects can then be studied.

  1. Effects of brief and intermediate exposures to sulfate submicron aerosols and sulfate injections on cardiopulmonary function of dogs and tracheal mucous velocity of sheep

    Energy Technology Data Exchange (ETDEWEB)

    Sackner, M.A. (Mount Sinai Medical Center, Miami Beach, FL); Dougherty, R.L.; Chapman, G.A.; Cipley, J.; Perez, D.; Kwoka, M.; Reinhart, M.; Brito, M.; Schreck, R.

    1981-06-01

    Pulmonary mechanics of anesthetized dogs were not changed or were minimally altered by breathing the following compounds as submicron aerosols in concentrations up to 17.3 mg/m/sup 3/ for 7.5 min: (1) sodium chloride (as a control), (2) sodium sulfate, (3) ammonium sulfate, (4) zinc sulfate, (5) zinc ammonium sulfate, (6) ammonium bisulfate, (7) aluminum sulfate, (8) manganese sulfate, (9) nickel sulfate, (10) copper sulfate, (11) ferrous fulfate, and (12) ferric sulfate. Submicron aerosols of these compounds in concentrations of 4.1 to 8.8 mg/m/sup 3/, administered for 4 h to anesthetized dogs, did not affect mechanics of breathing, hemodynamics, and arterial blood gases. In conscious sheep, tracheal mucous velocity was not altered by exposure to the submicron aerosols of the sulfate compounds. None of these compounds, injected iv in a dose of 1 mg, had adverse effects on mechanics of breathing, pulmonary and systemic hemodynamics, or arterial blood gases. In 100-mg injections, zinc sulfate and zinc ammonium sulfate produced a fall in cardiac output, systemic hypotension, hypoxemia, and metabolic acidosis. Copper sulfate at this dose produced pulmonary hypertension, a fall in cardiac output, hypoxemia, respiratory acidosis, and a decrease of specific total respiratory conductance. It is concluded that submicron aerosols of sulfate salts do not have adverse cardiopulmonary effects when administered in high concentrations for up to 4 h. However, prolonged exposure to high concentrations of zinc sulfate, zinc ammonium sulfate, and copper sulfate aerosols might have adverse cardiopulmonary effects.

  2. Nano patterning of micro-scale topographies for biological applications

    DEFF Research Database (Denmark)

    Bennetsen, Dines Tilsted

    2011-01-01

    topographies and mechanical properties. Cells are also exposed to a number of biological moieties, such as soluble cytokines, growth factors and trans-membrane receptor ligands. Since all these factors affect the cells concomitantly, it is challenging to elucidate the effect of a single factor. Simplifying...... the complex 3 dimensional ECM into a 2 dimensional model system is a way to study the effect of topography or mechanical properties. Presented here is a method that combines nanometer and submicron scale features with micron scale features by combining photolithography and nanosphere lithography...

  3. Fabrication of high aspect ratio submicron gratings on ˜100nm titanium membranes using electron beam lithography

    Science.gov (United States)

    Tiwari, Pragya; Mondal, Puspen; Srivastava, A. K.; Naik, P. A.

    2017-05-01

    We have developed a new technique for fabrication of 1:1 submicron gratings by means of single step electron beam lithography coupled with thin film deposition. The edge profile and the width ratio (line-to-groove) are easily controlled. Metal like gold or copper transmission gratings can be produced by an additional lift-off process. A 30kV electron beam was used to generate 500nm lines on standalone ˜2.3μm thick PMMA/Titanium. The dimensions of fabricated features together with their surface morphology and profiles were investigated by optical microscope and SEM. Low current slow writing coupled with special development is optimized to write structures smaller than the thickness of the resist membrane.

  4. Preparation of 1-pyrenebutyric acid and pyrene submicron dots by laser-induced molecular micro-jet implantation

    Energy Technology Data Exchange (ETDEWEB)

    Pihosh, Y., E-mail: Yuriy.Pihosh@nims.go.j [Materials Reliability Center, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Goto, M.; Kasahara, A.; Tosa, M. [Materials Reliability Center, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2009-11-30

    Pyrene and 1-pyrenebuturic acid molecules were deposited on glass and copper substrates with the formation of submicron dots by laser-induced molecular micro-jet implantation through polar and non-polar liquid layers. The size of the smallest 1-pyrenebuturic acid molecules dots prepared on a glass substrate by implantation through water and diiodomethane was estimated to be about 400 nm and 300 nm at laser fluences of 235 J/cm{sup 2} and 326 J/cm{sup 2}, respectively. The fluorescence and the Raman spectra showed that the implanted 1-pyrenebutyric acid molecules did not decompose during the implantation process. The smallest size of a pyrene dot was 700 nm at the laser fluence of 378 J/cm{sup 2}. However, the pyrene dots could be formed only by implantation through a water layer.

  5. Studies on solvatochromic properties of aminophenylstyryl-quinolinum dye, LDS 798, and its application in studying submicron lipid based structure.

    Science.gov (United States)

    Sarkar, Pabak; Luchowski, Rafal; Raut, Sangram; Sabnis, Nirupama; Remaley, Alan; Lacko, Andras G; Thamake, Sanjay; Gryczynski, Zygmunt; Gryczynski, Ignacy

    2010-12-01

    The styryl group of dyes has been used in cellular studies for over 20 years because of their solvatochromic and/or electrochromic properties. Here we report characterization of solubility and solvatochromic properties of a near infra-red styryl dye, styryl 11 or LDS 798. We have extended our studies to small unilamellar vesicles and lipid based nanoparticles and found that solvatochromic properties of this dye used in tandem with fluorescence correlation spectroscopy can be used to efficiently determine the diffusion coefficient and hence the size of the submicron lipid based particles. This technique has the potential to provide essential information about liposomal and vesicular structures and their movement in vitro and in situ. Published by Elsevier B.V.

  6. A Nordic Project Project on High Speed Low Power Design in Sub-micron CMOS Technology for Mobile

    DEFF Research Database (Denmark)

    Olesen, Ole

    1997-01-01

    This paper is a survey paper presenting the Nordic CONFRONT project and reporting some results from the group at CIE/DTU, Denmark. The objective of the project is to demonstrate the feasibility of sub-micron CMOS for the realisation of RF front-end circuits operating at frequencies in the 1.......8-2.0 GHz range. The ultimate goal is a single-chip transceiver, requiring only an external band-pass filter between the chip and the antenna. DECT has been chosen as a comparative standard to compare the new approaches developed in the work as well as to facilitate good knowledge transfer to industry. All...... of including good off-chip components in the design by use of innovative, inexpensive package technology.To achieve a higher level of integration, the project will use a novel codesign approach to the design strategy. Rather than making specifications based on a purely architectural approach, the work uses...

  7. Application of I-structure though-glass interconnect filled with submicron gold particles to a hermetic sealing device

    Science.gov (United States)

    Nomura, Kazuya; Okada, Akiko; Shoji, Shuichi; Ogashiwa, Toshinori; Mizuno, Jun

    2016-10-01

    We propose hermetic sealing of a glass-to-glass structure with an I-structure through-glass interconnect via (TGV) filled with submicron Au particles. The top and bottom bumps and the TGV were formed by a simple filling process with a bump-patterned dry film resist. The sealing devices consisting of two glass substrates were bonded via Au interlayers. Vacuum ultraviolet irradiation in the presence of oxygen gas (VUV/O3) pretreatment was used for low-temperature Au-Au bonding at 200 °C. The bonded samples showed He leakage rates of less than 1.3  ×  10-9 Pa m3 s-1. The cross-sectional scanning electron microscope images of the fabricated I-structure TGV showed perfect adhesion between the I-structure TGV and glass substrate. These results indicate that the proposed I-structure TGV is suitable for hermetic sealing devices.

  8. High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, N.; MacDowell, A.A.; Celestre, R.S.; Padmore, H.A.; Valek, B.C.; Bravman, J.C.; Spolenak, R.; Brown, W.L.; Marieb, T.; Fujimoto, H.; Batterman, B.W.; Patel, J.R.

    2002-03-26

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area 2D detector technology, have allowed us to develop an X-ray synchrotron technique capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular level. Owing to the relatively low absorption of X-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

  9. High Spatial Resolution Grain Orientation and Strain Mapping in Thin Films using Polychromatic Submicron X-ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Jamshed R.

    2002-06-14

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area 2D detector technology, have allowed us to develop a X-ray synchrotron technique capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular level. Owing to the relatively low absorption of X-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

  10. Submicron Y2O3 particles codoped with Eu and Tb ions: size controlled synthesis and tuning the luminescence emission.

    Science.gov (United States)

    Atabaev, Timur Sh; Kim, Hyung-Kook; Hwang, Yoon-Hwae

    2012-05-01

    Eu(3+) and Tb(3+) codoped Y(2)O(3) submicron particles were prepared using the simple urea homogeneous precipitation method. X-ray diffraction patterns revealed the synthesized particles to have a pure cubic Y(2)O(3) structure. Field-emission scanning electron microscopy and field-emission transmission electron microscopy showed that the synthesized particles had almost uniform spherical shapes. The luminescence color emission of the synthesized particles could be tuned from red due to the effective (5)D(0)→(7)F(j) (j=0, 1, 2 and 3) transitions within Eu(3+) to green due to the (5)D(4)→(7)F(5) transition within Tb(3+) by switching the excitation wavelength from 255 to 310 nm. Luminescence quenching was observed at high dopant concentrations. Strong and effective color-tunable emission is expected to find a wide range of applications in industry. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Scanning x-ray microdiffraction with submicron white beam for strain and orientation mapping in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, N.; MacDowell, A.A.; Spolenak, R.; Valek, B.C.; Bravman, J.C.; Brown, W.L.; Celestre, R.S.; Padmore, H.A.; Batterman, B.W.; Patel, J.R.

    2003-01-14

    Scanning X-ray Microdiffraction (m-SXRD) combines the use of high brilliance synchrotron sources with the latest achromatic X-ray focusing optics and fast large area 2D-detector technology. Using white beams or a combination of white and monochromatic beams, it allows for orientation and strain/stress mapping of polycrystalline thin films with submicron spatial resolution. The technique is described in detail as applied to the study of thin aluminium and copper blanket films and lines following electromigration testing and/or thermal cycling experiments. It is shown that there are significant orientation and strain/stress variations between grains and inside individual grains. A polycrystalline film when investigated at the granular (micron) level shows a highly mechanically inhomogeneous medium that allows insight into its mesoscopic properties. If the m-SXRD data are averaged over a macroscopic range, results show good agreement with direct macroscopic texture and stress measurements .

  12. Characterization and source apportionment of submicron aerosol with aerosol mass spectrometer during the PRIDE-PRD 2006 campaign

    Directory of Open Access Journals (Sweden)

    R. Xiao

    2011-07-01

    Full Text Available Size-resolved chemical compositions of non-refractory submicron aerosol were measured using an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS at the rural site Back Garden (BG, located ~50 km northwest of Guangzhou in July 2006. This paper characterized the submicron aerosol particles of regional air pollution in Pearl River Delta (PRD in the southern China. Organics and sulfate dominated the submicron aerosol compositions, with average mass concentrations of 11.8 ± 8.4 μg m−3 and 13.5 ± 8.7 μg m−3, respectively. Unlike other air masses, the air masses originated from Southeast-South and passing through the PRD urban areas exhibited distinct bimodal size distribution characteristics for both organics and sulfate: the first mode peaked at vacuum aerodynamic diameters (Dva ∼200 nm and the second mode occurred at Dva from 300–700 nm. With the information from AMS, it was found from this study that the first mode of organics in PRD regional air masses was contributed by both secondary organic aerosol formation and combustion-related emissions, which is different from most findings in other urban areas (first mode of organics primarily from combustion-related emissions. The analysis of AMS mass spectra data by positive matrix factorization (PMF model identified three sources of submicron organic aerosol including hydrocarbon-like organic aerosol (HOA, low volatility oxygenated organic aerosol (LV-OOA and semi-volatile oxygenated organic aerosol (SV-OOA. The strong correlation between HOA and EC indicated primary combustion emissions as the major source of HOA while a close correlation between SV-OOA and semi-volatile secondary species nitrate as well as between LV-OOA and nonvolatile secondary species sulfate suggested secondary aerosol formation as the major source of SV-OOA and LV-OOA at the BG site. However, LV-OOA was more aged than SV-OOA as its spectra was highly

  13. Characterization and source apportionment of submicron aerosol with aerosol mass spectrometer during the PRIDE-PRD 2006 campaign

    Science.gov (United States)

    Xiao, R.; Takegawa, N.; Zheng, M.; Kondo, Y.; Miyazaki, Y.; Miyakawa, T.; Hu, M.; Shao, M.; Zeng, L.; Gong, Y.; Lu, K.; Deng, Z.; Zhao, Y.; Zhang, Y. H.

    2011-07-01

    Size-resolved chemical compositions of non-refractory submicron aerosol were measured using an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS) at the rural site Back Garden (BG), located ~50 km northwest of Guangzhou in July 2006. This paper characterized the submicron aerosol particles of regional air pollution in Pearl River Delta (PRD) in the southern China. Organics and sulfate dominated the submicron aerosol compositions, with average mass concentrations of 11.8 ± 8.4 μg m-3 and 13.5 ± 8.7 μg m-3, respectively. Unlike other air masses, the air masses originated from Southeast-South and passing through the PRD urban areas exhibited distinct bimodal size distribution characteristics for both organics and sulfate: the first mode peaked at vacuum aerodynamic diameters (Dva) ∼200 nm and the second mode occurred at Dva from 300-700 nm. With the information from AMS, it was found from this study that the first mode of organics in PRD regional air masses was contributed by both secondary organic aerosol formation and combustion-related emissions, which is different from most findings in other urban areas (first mode of organics primarily from combustion-related emissions). The analysis of AMS mass spectra data by positive matrix factorization (PMF) model identified three sources of submicron organic aerosol including hydrocarbon-like organic aerosol (HOA), low volatility oxygenated organic aerosol (LV-OOA) and semi-volatile oxygenated organic aerosol (SV-OOA). The strong correlation between HOA and EC indicated primary combustion emissions as the major source of HOA while a close correlation between SV-OOA and semi-volatile secondary species nitrate as well as between LV-OOA and nonvolatile secondary species sulfate suggested secondary aerosol formation as the major source of SV-OOA and LV-OOA at the BG site. However, LV-OOA was more aged than SV-OOA as its spectra was highly correlated with the reference spectra of fulvic acid, an indicator of aged and

  14. One year online chemical speciation of submicron particulate matter (PM1) sampled at a French industrial and coastal site

    Science.gov (United States)

    Zhang, Shouwen; Riffault, Véronique; Dusanter, Sébastien; Augustin, Patrick; Fourmentin, Marc; Delbarre, Hervé

    2015-04-01

    The harbor of Dunkirk (Northern France) is surrounded by different industrial plants (metallurgy, petrochemistry, food processing, power plant, etc.), which emit gaseous and particulate pollutants such as Volatile Organic Compounds (VOCs), oxides of nitrogen (NOx) and sulfur (SO2), and submicron particles (PM1). These emissions are poorly characterized and their impact on neighboring urban areas has yet to be assessed. Studies are particularly needed in this type of complex environments to get a better understanding of PM1sources, especially from the industrial sector, their temporal variability, and their transformation. Several instruments, capable of real-time measurements (temporal resolution ≤ 30 min), were deployed at a site located downwind from the industrial area of Dunkirk for a one-year duration (July 2013-September 2014). An Aerosol Chemical Speciation Monitor (ACSM) and an Aethalometer monitored the main chemical species in the non-refractory submicron particles and black carbon, respectively. Concomitant measurements of trace gases and wind speed and direction were also performed. This dataset was analyzed considering four wind sectors, characteristics of marine, industrial, industrial-urban, and urban influences, and the different seasons. We will present a descriptive analysis of PM1, showing strong variations of ambient concentrations, as well as evidences of SO2 to SO4 gas-particle conversion when industrial plumes reached the monitoring site. The organic fraction measured by ACSM (37% of the total mass on average) was analyzed using a source-receptor model based on Positive Matrix Factorization (PMF) to identify chemical signatures of main emission sources and to quantify the contribution of each source to the PM1 budget given the wind sector. Four main factors were identified: hydrocarbon organic aerosol (HOA), oxygenated organic aerosol (OOA), biomass burning organic aerosol (BBOA) and cooking-like organic aerosol (COA). Overall, the total PM

  15. Thermal, structural and morphological properties of High Density Polyethylene matrix composites reinforced with submicron agro silica particles and Titania particles

    Directory of Open Access Journals (Sweden)

    Oluyemi O. Daramola

    2017-07-01

    Full Text Available HDPE—based composites samples filled with 2, 4, 6, 8 and 10 wt.% submicron agro-waste silica particles extracted from rice husk ash (RHA at constant 0.3 wt.% Titania loading were prepared using rapra single screw extruder at temperature of 200–230 °C. The extrudates were compressed with a laboratory carver press at a temperature of 230 °C for 10 min under applied pressure of 0.2 kPa and water cooled at 20 °C min−1. Thermal, structural and morphological properties of the composites were studied. The results of the thermogravimetric analysis (TGA revealed that the composites with 10 wt.% SiO2 have the best maximum thermal degradation temperature of 438.73 °C. The crystal structure of neat HDPE, and the siliceous composites developed revealed two obvious diffractive peaks of about 21.3° and 23.7° corresponding to typical crystal plane (1 1 0 and (2 0 0 of orthorhombic phase respectively. The diffractive peaks do not shift with the addition of silica particles; this clearly indicates that the addition of silica particles did not exert much effect on the crystalline structure of HDPE. There is no much difference in the interplanar distance (d-value. Lamellar thickness (L of HDPE increases with the addition of silica particles, which implies that silica particles aid the formation of more perfect crystals. Scanning electron microscopy studies indicated that there were chains inter diffusion and entanglement between HDPE matrix and the silica particles at lower weight fraction (2–4 wt.% of submicron silica particles which resulted into homogeneous dispersion of the particles within the matrix.

  16. Pulmonary clearance kinetics and extrapulmonary translocation of seven titanium dioxide nano- and submicron materials following intratracheal administration in rats.

    Science.gov (United States)

    Shinohara, Naohide; Oshima, Yutaka; Kobayashi, Toshio; Imatanaka, Nobuya; Nakai, Makoto; Ichinose, Takayuki; Sasaki, Takeshi; Kawaguchi, Kenji; Zhang, Guihua; Gamo, Masashi

    2015-01-01

    We evaluated and compared the pulmonary clearance kinetics and extrapulmonary translocations of seven titanium dioxide (TiO2) nano- and submicron particles with different characteristics, including size, shape and surface coating. Varying doses of TiO2 nano- and submicron particles dispersed in 0.2% disodium phosphate solution were intratracheally administered to male F344 rats. The rats were euthanized under anesthesia for 3, 28 and 91 days after administration. Ti levels in pulmonary and various extrapulmonary organs were determined using inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The lungs, including bronchoalveolar lavage fluid (BALF), contained 55-89% of the administered TiO2 dose at 3 days after administration. The pulmonary clearance rate constants, estimated using a one-compartment model, were higher after administration of 0.375-2.0 mg/kg body weight (bw) (0.016-0.020/day) than after administration of 3.0-6.0 mg/kg bw (0.0073-0.013/day) for six uncoated TiO2. In contrast, the clearance rate constant was 0.011, 0.0046 and 0.00018/day following administration of 0.67, 2.0 and 6.0 mg/kg bw TiO2 nanoparticle with Al(OH)3 coating, respectively. Translocation of TiO2 from the lungs to the thoracic lymph nodes increased in a time- and dose-dependent manner. Furthermore, the translocation of TiO2 from the lungs to the thoracic lymph nodes after 91 days was higher when Al(OH)3 coated TiO2 was administered (0.93-6.4%), as compared to uncoated TiO2 (0.016-1.8%). Slight liver translocation was observed (kidney, spleen and brain.

  17. Rates of induced abortion in Denmark according to age, previous births and previous abortions

    Directory of Open Access Journals (Sweden)

    Marie-Louise H. Hansen

    2009-11-01

    Full Text Available Background: Whereas the effects of various socio-demographic determinants on a woman's risk of having an abortion are relatively well-documented, less attention has been given to the effect of previous abortions and births. Objective: To study the effect of previous abortions and births on Danish women's risk of an abortion, in addition to a number of demographic and personal characteristics. Data and methods: From the Fertility of Women and Couples Dataset we obtained data on the number of live births and induced abortions by year (1981-2001, age (16-39, county of residence and marital status. Logistic regression analysis was used to estimate the influence of the explanatory variables on the probability of having an abortion in a relevant year. Main findings and conclusion: A woman's risk of having an abortion increases with the number of previous births and previous abortions. Some interactions were was found in the way a woman's risk of abortion varies with calendar year, age and parity. The risk of an abortion for women with no children decreases while the risk of an abortion for women with children increases over time. Furthermore, the risk of an abortion decreases with age, but relatively more so for women with children compared to childless women. Trends for teenagers are discussed in a separate section.

  18. A solvent-shrinkage method for producing polymeric microsieves with sub-micron size pores

    NARCIS (Netherlands)

    Vriezekolk, Erik; Kemperman, Antonius J.B.; Girones nogue, Miriam; de Vos, Wiebe Matthijs; Nijmeijer, Dorothea C.

    2013-01-01

    This paper presents a thorough investigation of a simple method to decrease the dimensions of polymeric microsieves. Pore sizes of microsieves are usually in the micrometer scale, but need to be reduced to below 1 µm to make the microsieves attractive for aqueous filtration applications. In this

  19. Bragg diffraction from sub-micron particles isolated by optical tweezers

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yuan, E-mail: ygao0709@anl.gov; Harder, Ross; Southworth, Stephen; Guest, Jeffrey; Ocola, Leonidas; Young, Linda [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Scherer, Norbert; Yan, Zijie [Department of Chemistry, University of Chicago, Chicago, IL 60637 (United States); Pelton, Matthew [Department of Physics, University of Maryland, Baltimore County, MD 21250 (United States)

    2016-07-27

    We describe an apparatus using dynamic holographic optical tweezers which is capable of trapping and aligning a single micron scale anisotropic ZnO particle for x-ray Bragg diffraction experiments. The optical tweezers demonstrate enough stability to perform coherent x-ray diffraction imaging.

  20. Analysis and Test Development for Parasitic Fails in Deep Sub-Micron Memory Devices

    NARCIS (Netherlands)

    Irobi, I.S.

    2011-01-01

    Emerging technology trends are gravitating towards extremely high levels of integration at the package and chip levels, and use of deeply scaled technology in nanometer, approaching 10nm CMOS. Challenges will arise due to the ability to design complex systems such as robots that encompass sensors,

  1. Experimental Hypervelocity Dust Impact in Olivine: FIB/TEM Characterization of Micron-Scale Craters with Comparison to Natural and Laser-Simulated Small-Scale Impact Effects

    Science.gov (United States)

    Christoffersen, R.; Loeffler, M. J.; Rahman, Z.; Dukes, C.; IMPACT Team

    2017-01-01

    The space weathering of regoliths on airless bodies and the formation of their exospheres is driven to a large extent by hypervelocity impacts from the high relative flux of micron to sub-micron meteoroids that comprise approximately 90 percent of the solar system meteoroid population. Laboratory hypervelocity impact experiments are crucial for quantifying how these small impact events drive space weathering through target shock, melting and vaporization. Simulating these small scale impacts experimentally is challenging because the natural impactors are both very small and many have velocities above the approximately 8 kilometers-per-second limit attainable by conventional chemical/light gas accelerator technology. Electrostatic "dust" accelerators, such as the one recently developed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS), allow the experimental velocity regime to be extended up to tens of kilometers-per-second. Even at these velocities the region of latent target damage created by each impact, in the form of microcraters or pits, is still only about 0.1 to 10 micrometers in size. Both field-emission analytical scanning electron microscopy (FE-SEM) and advanced field-emission scanning transmission electron microscopy (FE-STEM) are uniquely suited for characterizing the individual dust impact sites in these experiments. In this study, we have used both techniques, along with focused ion beam (FIB) sample preparation, to characterize the micrometer to nanometer scale effects created by accelerated dust impacts into olivine single crystals. To our knowledge this work presents the first TEM-scale characterization of dust impacts into a key solar system silicate mineral using the CCLDAS facility. Our overarching goal for this work is to establish a basis to compare with our previous results on natural dust-impacted lunar olivine and laser-irradiated olivine.

  2. Organic composition of single and submicron particles in different regions of western North America and the eastern Pacific during INTEX-B 2006

    Directory of Open Access Journals (Sweden)

    D. A. Day

    2009-08-01

    Full Text Available Single particles were collected from an aircraft platform as part of the Intercontinental Chemical Transport Experiment – Phase B (INTEX-B conducted over the eastern Pacific and western North America. Single particle spectra were obtained using scanning transmission X-ray microscopy-near edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS. Bulk submicron particles were also collected and organic functional group and elemental concentrations were quantified with Fourier transform infrared (FTIR spectroscopy and X-ray fluorescence (XRF. Single particle spectra were classified into metaclasses associated with different sources and atmospheric processing. Particles with spectra indicative of secondary organic aerosol production and combustion sources were found at several locations and a range of altitudes. At lower altitudes, particles with spectra resembling soil dust and biomass burning fingerprints were commonly observed. The types of particle spectra most commonly observed aloft were similar to those observed during a previous study over the northwestern Pacific, indicating that long-range transport may have been an important particle source. Single particle spectra provided evidence that condensation and surface-limited oxidation contributed to particle growth. Organic mass (OM concentrations ranged from 1 to 7 μg m−3 and averaged 2.4–4.1 μg m−3. Alkane functional groups were the largest fraction of OM, averaging 1.9–2.1 μg m−3 or 50–76% of OM, followed by alcohol functional groups (0.35–0.39 μg m−3, 9–14%. Organic and elemental concentrations are compared within and among geographical air mass regions: "Pacific" free troposphere, "Continental" free troposphere, "Seattle" metropolitan region, and the California "Central Valley". OM concentrations were highest and most variable in the Central Valley (3.5±2 μg m−3. Oxygen-to-carbon ratios were

  3. Seasonal characterization of submicron aerosol chemical composition and organic aerosol sources in the southeastern United States: Atlanta, Georgia,and Look Rock, Tennessee

    Science.gov (United States)

    Hapsari Budisulistiorini, Sri; Baumann, Karsten; Edgerton, Eric S.; Bairai, Solomon T.; Mueller, Stephen; Shaw, Stephanie L.; Knipping, Eladio M.; Gold, Avram; Surratt, Jason D.

    2016-04-01

    A year-long near-real-time characterization of non-refractory submicron aerosol (NR-PM1) was conducted at an urban (Atlanta, Georgia, in 2012) and rural (Look Rock, Tennessee, in 2013) site in the southeastern US using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) collocated with established air-monitoring network measurements. Seasonal variations in organic aerosol (OA) and inorganic aerosol species are attributed to meteorological conditions as well as anthropogenic and biogenic emissions in this region. The highest concentrations of NR-PM1 were observed during winter and fall seasons at the urban site and during spring and summer at the rural site. Across all seasons and at both sites, NR-PM1 was composed largely of OA (up to 76 %) and sulfate (up to 31 %). Six distinct OA sources were resolved by positive matrix factorization applied to the ACSM organic mass spectral data collected from the two sites over the 1 year of near-continuous measurements at each site: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), semi-volatile oxygenated OA (SV-OOA), low-volatility oxygenated OA (LV-OOA), isoprene-derived epoxydiols (IEPOX) OA (IEPOX-OA) and 91Fac (a factor dominated by a distinct ion at m/z 91 fragment ion previously observed in biogenic influenced areas). LV-OOA was observed throughout the year at both sites and contributed up to 66 % of total OA mass. HOA was observed during the entire year only at the urban site (on average 21 % of OA mass). BBOA (15-33 % of OA mass) was observed during winter and fall, likely dominated by local residential wood burning emission. Although SV-OOA contributes quite significantly ( ˜ 27 %), it was observed only at the urban site during colder seasons. IEPOX-OA was a major component (27-41 %) of OA at both sites, particularly in spring and summer. An ion fragment at m/z 75 is well correlated with the m/z 82 ion associated with the aerosol mass spectrum of IEPOX-derived secondary organic aerosol (SOA). The

  4. Submicron structure random field on granular soil material with retinex algorithm optimization

    OpenAIRE

    Liang Yu; Tao Chenyuan; Zhou Bingcheng; Huang Shuai; Huang Linchong

    2017-01-01

    In this paper, a Retinex scale optimized image enhancement algorithm is proposed, which can enhance the micro vision image and eliminate the influence of the uneven illumination. Based on that, a random geometric model of the microstructure of granular materials is established with Monte-Carlo method, the numerical simulation including consolidation process of granular materials is compared with the experimental data. The results have proved that the random field method with Retinex image enh...

  5. Study of Submicron Particle Size Distributions by Laser Doppler Measurement of Brownian Motion.

    Science.gov (United States)

    1984-10-29

    acquisition and recording apparatus; and c) Development of appropriate software for analysis of signals obtained from the Brownian motion instrument...time scales (e.g., the transit time of the A-17 .- -. . , " 2.0 19 _j 1.2 08 0.6 0.4 0.2 0.0 0 500 1000 1500 2000 TIPOE STEP (10 ns/step) 2.0 1.8

  6. Characterization of near-highway submicron aerosols in New York City with a high-resolution aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    Y. L. Sun

    2012-02-01

    Full Text Available Knowledge of the variations of mass concentration, chemical composition and size distributions of submicron aerosols near roadways is of importance for reducing exposure assessment uncertainties in health effects studies. The goal of this study is to deploy and evaluate an Atmospheric Sciences Research Center-Mobile Laboratory (ASRC-ML, equipped with a suite of rapid response instruments for characterization of traffic plumes, adjacent to the Long Island Expressway (LIE – a high-traffic highway in the New York City Metropolitan Area. In total, four measurement periods, two in the morning and two in the evening were conducted at a location approximately 30 m south of the LIE. The mass concentrations and size distributions of non-refractory submicron aerosol (NR-PM1 species were measured in situ at a time resolution of 1 min by an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer, along with rapid measurements (down to 1 Hz of gaseous pollutants (e.g. HCHO, NO2, NO, O3, and CO2, etc., black carbon (BC, and particle number concentrations and size distributions. Particulate organics varied dramatically during periods with high traffic influences from the nearby roadway. The variations were mainly observed in the hydrocarbon-like organic aerosol (HOA, a surrogate for primary OA from vehicle emissions. The inorganic species (sulfate, ammonium, and nitrate and oxygenated OA (OOA showed much smoother variations indicating minor impacts from traffic emissions. The concentration and chemical composition of NR-PM1 also varied differently on different days depending on meteorology, traffic intensity and vehicle types. Overall, organics dominated the traffic-related NR-PM1 composition (>60% with HOA accounting for a major fraction of OA. The traffic-influenced organics showed two distinct modes in mass-weighted size distributions, peaking at ∼120 nm and 500 nm (vacuum

  7. Fabrication of a high-aspect-ratio sub-micron tool using a cathode coated with stretched-out insulating layers

    Science.gov (United States)

    Zeng, Yongbin; Wang, Yufeng; Qu, Ningsong; Zhu, Di

    2013-09-01

    This paper describes a method for preparing a high-aspect-ratio sub-micron tool using a cathode coated with stretched-out insulating layers and a straight reciprocating motion applied at the anode via the liquid membrane electrochemical machining (ECM). Simulation results indicate that the application of a cathode coated with stretched-out insulating layers is beneficial for the localization of ECM. Moreover, a mathematical model was derived to estimate the final average diameter of the fabricated tools. Experiments were conducted to verify the versatility and feasibility of the proposed method and its mathematical model. It was observed that the calculated and the experimental results are in good agreement with each other. A sub-micron tool with an average diameter 140.8 nm and an aspect ratio up to 50 was fabricated using the proposed method.

  8. Enhanced Etching, Surface Damage Recovery, and Submicron Patterning of Hybrid Perovskites using a Chemically Gas-Assisted Focused-Ion Beam for Subwavelength Grating Photonic Applications

    KAUST Repository

    Alias, Mohd Sharizal

    2015-12-22

    The high optical gain and absorption of organic–inorganic hybrid perovskites have attracted attention for photonic device applications. However, owing to the sensitivity of organic moieties to solvents and temperature, device processing is challenging, particularly for patterning. Here, we report the direct patterning of perovskites using chemically gas-assisted focused-ion beam (GAFIB) etching with XeF2 and I2 precursors. We demonstrate etching enhancement in addition to controllability and marginal surface damage compared to focused-ion beam (FIB) etching without precursors. Utilizing the GAFIB etching, we fabricated a uniform and periodic submicron perovskite subwavelength grating (SWG) absorber with broadband absorption and nanoscale precision. Our results demonstrate the use of FIB as a submicron patterning tool and a means of providing surface treatment (after FIB patterning to minimize optical loss) for perovskite photonic nanostructures. The SWG absorber can be patterned on perovskite solar cells to enhance the device efficiency through increasing light trapping and absorption.

  9. Enhanced Etching, Surface Damage Recovery, and Submicron Patterning of Hybrid Perovskites using a Chemically Gas-Assisted Focused-Ion Beam for Subwavelength Grating Photonic Applications.

    Science.gov (United States)

    Alias, Mohd S; Yang, Yang; Ng, Tien K; Dursun, Ibrahim; Shi, Dong; Saidaminov, Makhsud I; Priante, Davide; Bakr, Osman M; Ooi, Boon S

    2016-01-07

    The high optical gain and absorption of organic-inorganic hybrid perovskites have attracted attention for photonic device applications. However, owing to the sensitivity of organic moieties to solvents and temperature, device processing is challenging, particularly for patterning. Here, we report the direct patterning of perovskites using chemically gas-assisted focused-ion beam (GAFIB) etching with XeF2 and I2 precursors. We demonstrate etching enhancement in addition to controllability and marginal surface damage compared to focused-ion beam (FIB) etching without precursors. Utilizing the GAFIB etching, we fabricated a uniform and periodic submicron perovskite subwavelength grating (SWG) absorber with broadband absorption and nanoscale precision. Our results demonstrate the use of FIB as a submicron patterning tool and a means of providing surface treatment (after FIB patterning to minimize optical loss) for perovskite photonic nanostructures. The SWG absorber can be patterned on perovskite solar cells to enhance the device efficiency through increasing light trapping and absorption.

  10. Facile synthesis and stable cycling ability of hollow submicron silicon oxide–carbon composite anode material for Li-ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joong-Yeon; Nguyen, Dan Thien [Department of Fine Chemical Engineering & Applied Chemistry, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kang, Joon-Sup [Department of Energy Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Song, Seung-Wan, E-mail: swsong@cnu.ac.kr [Department of Fine Chemical Engineering & Applied Chemistry, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Department of Energy Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2015-06-05

    Highlights: • Hollow submicron SiO{sub 2}–carbon composite material was synthesized using Si{sup 4+}-citrate chelation. • Composite material possessed a homogeneous distribution of SiO{sub 2} and carbon. • Composite electrode delivered ⩾600 mAh/g with a stable cycling stability. • This materials design and synthesis provides a useful platform for scalable production. - Abstract: Advanced SiO{sub 2}–carbon composite anode active material for lithium-ion battery has been synthesized through a simple chelation of silicon cation with citrate in a glyme-based solvent. The resultant composite material demonstrates a homogeneous distribution of constituents over the submicron particles and a unique hollow spherical microstructure, which provides an enhanced electrical conductivity and better accommodation of volume change of silicon during electrochemical charge–discharge cycling, respectively. As a result, the composite electrode exhibits a high cycling stability delivering the capacity retention of 91% at the 100th cycle and discharge capacities of 662–602 mAh/g and coulombic efficiencies of 99.8%. This material synthesis is scalable and cost-effective in preparing various submicron or micron composite electrode materials.

  11. SiO2/ZnO Composite Hollow Sub-Micron Fibers: Fabrication from Facile Single Capillary Electrospinning and Their Photoluminescence Properties.

    Science.gov (United States)

    Song, Guanying; Li, Zhenjiang; Li, Kaihua; Zhang, Lina; Meng, Alan

    2017-02-24

    In this work, SiO2/ZnO composite hollow sub-micron fibers were fabricated by a facile single capillary electrospinning technique followed by calcination, using tetraethyl orthosilicate (TEOS), polyvinylpyrrolidone (PVP) and ZnO nanoparticles as raw materials. The characterization results of the scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) spectra indicated that the asprepared composite hollow fibers consisted of amorphous SiO2 and hexagonal wurtzite ZnO. The products revealed uniform tubular structure with outer diameters of 400-500 nm and wall thickness of 50-60 nm. The gases generated and the directional escaped mechanism was proposed to illustrate the formation of SiO2/ZnO composite hollow sub-micron fibers. Furthermore, a broad blue emission band was observed in the photoluminescence (PL) of SiO2/ZnO composite hollow sub-micron fibers, exhibiting great potential applications as blue light-emitting candidate materials.

  12. SiO2/ZnO Composite Hollow Sub-Micron Fibers: Fabrication from Facile Single Capillary Electrospinning and Their Photoluminescence Properties

    Directory of Open Access Journals (Sweden)

    Guanying Song

    2017-02-01

    Full Text Available In this work, SiO2/ZnO composite hollow sub-micron fibers were fabricated by a facile single capillary electrospinning technique followed by calcination, using tetraethyl orthosilicate (TEOS, polyvinylpyrrolidone (PVP and ZnO nanoparticles as raw materials. The characterization results of the scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD and Fourier transform infrared spectroscopy (FT-IR spectra indicated that the asprepared composite hollow fibers consisted of amorphous SiO2 and hexagonal wurtzite ZnO. The products revealed uniform tubular structure with outer diameters of 400–500 nm and wall thickness of 50–60 nm. The gases generated and the directional escaped mechanism was proposed to illustrate the formation of SiO2/ZnO composite hollow sub-micron fibers. Furthermore, a broad blue emission band was observed in the photoluminescence (PL of SiO2/ZnO composite hollow sub-micron fibers, exhibiting great potential applications as blue light-emitting candidate materials.

  13. Technology Scaling Impact on Embedded ADC Design for Telecom Receivers

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Andreani, Pietro; Malcovati, Piero

    2005-01-01

    This paper is concerned with the impact of technology scaling on the choice of A/D converters in telecom receivers. It is shown that the trend of diminishing feature size, together with better matching of passive components, allows the use of A/D topologies traditionally confined to low......-frequency, medium-resolution applications. The design of a 10 bit 20 MS/s ADC using the successive approximation algorithm is presented in order to validate the presented concepts. By using a deep-submicron technology, the speed of the chosen architecture is pushed to meet the desired output rate....

  14. Nanometer-Scale Chemistry of a Calcite Biomineralization Template: Implications for Skeletal Composition and Nucleation

    Science.gov (United States)

    Bonnin, Elisa A.; Perea, Daniel E.; Spero, Howard J.; Zhu, Zihua; Winters, Maria; Hönisch, Bärbel; Russell, Ann D.; Fehrenbacher, Jennifer S.; Gagnon, Alexander C.

    2016-01-01

    Plankton, corals, and other organisms produce calcium carbonate skeletons that are integral to their survival, form a key component of the global carbon cycle, and record an archive of past oceanographic conditions in their geochemistry. A key aspect of the formation of these biominerals is the interaction between organic templating structures and mineral precipitation processes. Laboratory-based studies have shown that these atomic-scale processes can profoundly influence the architecture and composition of minerals, but their importance in calcifying organisms is poorly understood because it is difficult to measure the chemistry of in vivo biomineral interfaces at spatially relevant scales. Understanding the role of templates in biomineral nucleation, and their importance in skeletal geochemistry requires an integrated, multiscale approach, which can place atom-scale observations of organic-mineral interfaces within a broader structural and geochemical context. Here we map the chemistry of an embedded organic template structure within a carbonate skeleton of the foraminifera Orbulina universa using both atom probe tomography (APT), a 3D chemical imaging technique with Ångström-level spatial resolution, and time-of-flight secondary ionization mass spectrometry (ToF-SIMS), a 2D chemical imaging technique with submicron resolution. We quantitatively link these observations, revealing that the organic template in O. universa is uniquely enriched in both Na and Mg, and contributes to intraskeletal chemical heterogeneity. Our APT analyses reveal the cation composition of the organic surface, offering evidence to suggest that cations other than Ca2+, previously considered passive spectator ions in biomineral templating, may be important in defining the energetics of carbonate nucleation on organic templates. PMID:27794119

  15. Beam diameter thresholds as applying light depolarization for effective submicron and micron root mean square roughness evaluation.

    Science.gov (United States)

    Liu, Linsheng; Nonaka, Kazuhiro

    2017-09-01

    To further study the microscopic mechanism and beam diameter effect during light depolarization (LDP), we developed a compact laser instrument (λ=632.8  nm) with an adjustable beam diameter of ≥18  μm (approximately 28λ). Six nickel plate samples with rms roughness, Rq, of 42 nm to 2.3 μm (i.e., 0.067-3.7λ) fabricated by the fine-honing method are examined. To analyze the beam diameter effect as applying LDP for submicron and micron Rq evaluation, the cross-sectional beam-spot size (BSS) is adjusted from 20 μm to 650 μm during off-specular inspections. The results of BSS ≤40  μm (i.e., 60λ) have a 10-nm-level Rq sensitivity, while those of BSS ≥140  μm (220λ) have about a 100 times weaker sensitivity. It means that BSS of 60λ and 220λ should have instructional significance as applying LDP for precision levels of 10 nm and 1 μm surface roughness analyses, respectively. In addition, since the instrument is simple, portable, stable, and low-cost, it has great potential for both LDP analyses and practical online roughness testing.

  16. A novel method to detect unlabeled inorganic nanoparticles and submicron particles in tissue by sedimentation field-flow fractionation

    Directory of Open Access Journals (Sweden)

    Yost Garold S

    2008-12-01

    Full Text Available Abstract A novel methodology to detect unlabeled inorganic nanoparticles was experimentally demonstrated using a mixture of nano-sized (70 nm and submicron (250 nm silicon dioxide particles added to mammalian tissue. The size and concentration of environmentally relevant inorganic particles in a tissue sample can be determined by a procedure consisting of matrix digestion, particle recovery by centrifugation, size separation by sedimentation field-flow fractionation (SdFFF, and detection by light scattering. Background Laboratory nanoparticles that have been labeled by fluorescence, radioactivity, or rare elements have provided important information regarding nanoparticle uptake and translocation, but most nanomaterials that are commercially produced for industrial and consumer applications do not contain a specific label. Methods Both nitric acid digestion and enzyme digestion were tested with liver and lung tissue as well as with cultured cells. Tissue processing with a mixture of protease enzymes is preferred because it is applicable to a wide range of particle compositions. Samples were visualized via fluorescence microscopy and transmission electron microscopy to validate the SdFFF results. We describe in detail the tissue preparation procedures and discuss method sensitivity compared to reported levels of nanoparticles in vivo. Conclusion Tissue digestion and SdFFF complement existing techniques by precisely identifying unlabeled metal oxide nanoparticles and unambiguously distinguishing nanoparticles (diameter

  17. A novel method to detect unlabeled inorganic nanoparticles and submicron particles in tissue by sedimentation field-flow fractionation

    Science.gov (United States)

    Deering, Cassandra E; Tadjiki, Soheyl; Assemi, Shoeleh; Miller, Jan D; Yost, Garold S; Veranth, John M

    2008-01-01

    A novel methodology to detect unlabeled inorganic nanoparticles was experimentally demonstrated using a mixture of nano-sized (70 nm) and submicron (250 nm) silicon dioxide particles added to mammalian tissue. The size and concentration of environmentally relevant inorganic particles in a tissue sample can be determined by a procedure consisting of matrix digestion, particle recovery by centrifugation, size separation by sedimentation field-flow fractionation (SdFFF), and detection by light scattering. Background Laboratory nanoparticles that have been labeled by fluorescence, radioactivity, or rare elements have provided important information regarding nanoparticle uptake and translocation, but most nanomaterials that are commercially produced for industrial and consumer applications do not contain a specific label. Methods Both nitric acid digestion and enzyme digestion were tested with liver and lung tissue as well as with cultured cells. Tissue processing with a mixture of protease enzymes is preferred because it is applicable to a wide range of particle compositions. Samples were visualized via fluorescence microscopy and transmission electron microscopy to validate the SdFFF results. We describe in detail the tissue preparation procedures and discuss method sensitivity compared to reported levels of nanoparticles in vivo. Conclusion Tissue digestion and SdFFF complement existing techniques by precisely identifying unlabeled metal oxide nanoparticles and unambiguously distinguishing nanoparticles (diameter<100 nm) from both soluble compounds and from larger particles of the same nominal elemental composition. This is an exciting capability that can facilitate epidemiological and toxicological research on natural and manufactured nanomaterials. PMID:19055780

  18. Cold Spray Coating of Submicronic Ceramic Particles on Poly(vinyl alcohol) in Dry and Hydrogel States

    Science.gov (United States)

    Moreau, David; Borit, François; Corté, Laurent; Guipont, Vincent

    2017-06-01

    We report an approach using cold spray technology to coat poly(vinyl alcohol) (PVA) in polymer and hydrogel states with hydroxyapatite (HA). Using porous aggregated HA powder, we hypothesized that fragmentation of the powder upon cold spray could lead to formation of a ceramic coating on the surface of the PVA substrate. However, direct spraying of this powder led to complete destruction of the swollen PVA hydrogel substrate. As an alternative, HA coatings were successfully produced by spraying onto dry PVA substrates prior to swelling in water. Dense homogeneous HA coatings composed of submicron particles were obtained using rather low-energy spraying parameters (temperature 200-250 °C, pressure 1-3 MPa). Coated PVA substrates could swell in water without removal of the ceramic layer to form HA-coated hydrogels. Microscopic observations and in situ measurements were used to explain how local heating and impact of sprayed aggregates induced surface roughening and strong binding of HA particles to the molten PVA substrate. Such an approach could lead to design of ceramic coatings whose roughness and crystallinity can be finely adjusted to improve interfacing with biological tissues.

  19. Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes

    Energy Technology Data Exchange (ETDEWEB)

    Famiano, M.A.

    1997-07-07

    A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time ({approximately}1 {micro}s to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, {sup 137}Cs gamma rays, and electrons from a {sup 90}Sr/{sup 90}Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired.

  20. Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%.

    KAUST Repository

    Kim, Hui-Seon

    2012-08-21

    We report on solid-state mesoscopic heterojunction solar cells employing nanoparticles (NPs) of methyl ammonium lead iodide (CH(3)NH(3))PbI(3) as light harvesters. The perovskite NPs were produced by reaction of methylammonium iodide with PbI(2) and deposited onto a submicron-thick mesoscopic TiO(2) film, whose pores were infiltrated with the hole-conductor spiro-MeOTAD. Illumination with standard AM-1.5 sunlight generated large photocurrents (J(SC)) exceeding 17 mA/cm(2), an open circuit photovoltage (V(OC)) of 0.888 V and a fill factor (FF) of 0.62 yielding a power conversion efficiency (PCE) of 9.7%, the highest reported to date for such cells. Femto second laser studies combined with photo-induced absorption measurements showed charge separation to proceed via hole injection from the excited (CH(3)NH(3))PbI(3) NPs into the spiro-MeOTAD followed by electron transfer to the mesoscopic TiO(2) film. The use of a solid hole conductor dramatically improved the device stability compared to (CH(3)NH(3))PbI(3) -sensitized liquid junction cells.

  1. Characterization of the critical current and physical properties of superconducting epitaxial NbTiN sub-micron structures

    Energy Technology Data Exchange (ETDEWEB)

    Klimov, A., E-mail: aklimov@ite.waw.pl [Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warsaw (Poland); Słysz, W.; Guziewicz, M. [Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warsaw (Poland); Kolkovsky, V.; Zaytseva, I.; Malinowski, A. [Institute of Physics Polish Academy of Science, Al. Lotników 32/46, 02-668 Warsaw (Poland)

    2017-05-15

    Highlights: • This manuscript presents investigation of the critical current dependence of Nb(Ti)N nanostructured superconducting single photon detectors (SNSPD) in function of temperature and applied magnetic field. • Presented results are complimentary and compared with the same data received for submicron-wide single bridge Nb(Ti)N structures. • Our data demonstrate significant influence of local constrictions on physical properties of our SNSPD detectors. - Abstract: Measurements of critical current in NbTiN as a function of applied magnetic field and temperature are reported for two samples: 700-nm-wide bridge and 100-nm-wide meander. In 700-nm-wide NbTiN bridge we pinpointed the limiting factors for the critical current density to be current-driven vortex de-pinning at low temperatures and thermally activated flux flow closer to the transition temperature. In 100-nm-wide NbTiN meander we found phase slips activation, accompanied by hotspots formation at all measured temperatures. These two types of structures demonstrate different dependence of the critical current on the applied magnetic field. Although our NbTiN meander structures has high de-pairing critical current densities ∼10{sup 7} A/cm{sup 2} at low temperatures, the real critical currents are smaller due to the presence of the local constrictions.

  2. Effects of food intake on the mucoadhesive and gastroretentive properties of submicron-sized chitosan-coated liposomes.

    Science.gov (United States)

    Sugihara, Hikaru; Yamamoto, Hiromitsu; Kawashima, Yoshiaki; Takeuchi, Hirofumi

    2012-01-01

    The gastrointestinal transition of mucoadhesive drug carriers may be affected by food intake, since food changes the physiological conditions of the gastrointestinal tract, and the food content itself is a physical obstruction for the drug carriers. Here we investigated the effects of food intake on the gastrointestinal transition and mucoadhesive function of submicron-sized chitosan-coated liposomes (ssCS-Lip). The stomach and small intestine were removed after oral administration of ssCS-Lip and non-coated liposomes (ssLip) containing fluorescent dye to fasted or fed rats, and retentive properties were quantitatively confirmed by measuring the amount of dye in each part of the gastrointestinal tract. Both types of liposome were retained in the stomach at approx. 40% in the fed rats at 1 h after oral administration, whereas transitions in the intestine were reduced compared to the fasted rats. However, the transition of ssCS-Lip in intestine was prolonged compared to ssLip even, in the fed state. The mucoadhesive behavior of ssCS-Lip was evaluated by confocal laser scanning microscopy. The ssCS-Lip tended to penetrate into the mucosal part of the intestine, and in addition, ssCS-Lip was detected in the basolateral side in both conditions, and therefore the mucopenetrative function was confirmed in the fed condition. Based on these results, we confirmed that ssCS-Lip shows a predominant gastrointestinal transition and mucopenetration, even after food intake.

  3. Chemical vapor deposition of silicon nanodots on TiO{sub 2} submicronic powders in vibrated fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Cadoret, L. [Laboratoire de Genie Chimique, UMR CNRS 5503, Universite de Toulouse, ENSIACET/INPT, 4 allee Emile Monso, BP 74233, 31432 Toulouse Cedex 4 (France); Rossignol, C.; Dexpert-Ghys, J. [CEMES, UPR CNRS 8011, UPS-Toulouse, 29 rue Jean Marvig, 31055 Toulouse Cedex 4 (France); Caussat, B., E-mail: Brigitte.Caussat@ensiacet.fr [Laboratoire de Genie Chimique, UMR CNRS 5503, Universite de Toulouse, ENSIACET/INPT, 4 allee Emile Monso, BP 74233, 31432 Toulouse Cedex 4 (France)

    2010-06-15

    Silicon nanodots have been deposited on TiO{sub 2} submicronic powders in a vibrated fluidized bed chemical vapor deposition (FBCVD) reactor from silane SiH{sub 4}. Deposition conditions involving very low deposition rates have been studied. After treatment, powders are under the form of micronic agglomerates. In the operating range tested, this agglomerates formation mainly depends on the fluidization conditions and not on the CVD parameters. The best results have been obtained for anatase TiO{sub 2} powders for which the conditions of fluidization have been the most optimized. For these anatase powders, agglomerates are porous. SEM and TEM imaging prove that silicon nanodots (8-10 nm in size) have been deposited on the surface of particles and that this deposition is uniform on the whole powders and conformal around each grain, even if not fully continuous. Raman spectroscopy shows that the TiO{sub 2} powders have been partially reduced into TiO{sub 2-x} during deposition. The TiO{sub 2} stoichiometry can be recovered by annealing under air, and IR spectroscopy indicates that the deposited silicon nanodots have been at least partly oxidized into SiO{sub 2} after this annealing.

  4. Mie scattering from submicron-sized CO2 clusters formed in a supersonic expansion of a gas mixture.

    Science.gov (United States)

    Jinno, S; Fukuda, Y; Sakaki, H; Yogo, A; Kanasaki, M; Kondo, K; Faenov, A Ya; Skobelev, I Yu; Pikuz, T A; Boldarev, A S; Gasilov, V A

    2013-09-09

    A detailed mathematical model is presented for a submicron-sized cluster formation in a binary gas mixture flowing through a three-staged conical nozzle. By measuring the angular distribution of light scattered from the clusters, the size of CO(2) clusters, produced in a supersonic expansion of the mixture gas of CO(2)(30%)/H(2)(70%) or CO(2)(10%)/He(90%), has been evaluated using the Mie scattering method. The mean sizes of CO(2) clusters are estimated to be 0.28 ± 0.03 μm for CO(2)/H(2) and 0.26 ± 0.04 μm for CO(2)/He, respectively. In addition, total gas density profiles in radial direction of the gas jet, measuring the phase shift of the light passing through the target by utilizing an interferometer, are found to be agreed with the numerical modeling within a factor of two. The dryness (= monomer/(monomer + cluster) ratio) in the targets is found to support the numerical modeling. The apparatus developed to evaluate the cluster-gas targets proved that our mathematical model of cluster formation is reliable enough for the binary gas mixture.

  5. Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%

    Science.gov (United States)

    Kim, Hui-Seon; Lee, Chang-Ryul; Im, Jeong-Hyeok; Lee, Ki-Beom; Moehl, Thomas; Marchioro, Arianna; Moon, Soo-Jin; Humphry-Baker, Robin; Yum, Jun-Ho; Moser, Jacques E.; Grätzel, Michael; Park, Nam-Gyu

    2012-01-01

    We report on solid-state mesoscopic heterojunction solar cells employing nanoparticles (NPs) of methyl ammonium lead iodide (CH3NH3)PbI3 as light harvesters. The perovskite NPs were produced by reaction of methylammonium iodide with PbI2 and deposited onto a submicron-thick mesoscopic TiO2 film, whose pores were infiltrated with the hole-conductor spiro-MeOTAD. Illumination with standard AM-1.5 sunlight generated large photocurrents (JSC) exceeding 17 mA/cm2, an open circuit photovoltage (VOC) of 0.888 V and a fill factor (FF) of 0.62 yielding a power conversion efficiency (PCE) of 9.7%, the highest reported to date for such cells. Femto second laser studies combined with photo-induced absorption measurements showed charge separation to proceed via hole injection from the excited (CH3NH3)PbI3 NPs into the spiro-MeOTAD followed by electron transfer to the mesoscopic TiO2 film. The use of a solid hole conductor dramatically improved the device stability compared to (CH3NH3)PbI3 -sensitized liquid junction cells. PMID:22912919

  6. Submicron structure random field on granular soil material with retinex algorithm optimization

    Science.gov (United States)

    Liang, Yu; Tao, Chenyuan; Zhou, Bingcheng; Huang, Shuai; Huang, Linchong

    2017-06-01

    In this paper, a Retinex scale optimized image enhancement algorithm is proposed, which can enhance the micro vision image and eliminate the influence of the uneven illumination. Based on that, a random geometric model of the microstructure of granular materials is established with Monte-Carlo method, the numerical simulation including consolidation process of granular materials is compared with the experimental data. The results have proved that the random field method with Retinex image enhancement algorithm is effective, the image of microstructure of granular materials becomes clear and the contrast ratio is improved, after using Retinex image enhancement algorithm to enhance the CT image. The fidelity of enhanced image is higher than that dealing with other method, which have explained that the algorithm can preserve the microstructure information of the image well. The result of numerical simulation is similar with the one obtained from conventional three axis consolidation test, which proves that the simulation result is reliable.

  7. Submicron structure random field on granular soil material with retinex algorithm optimization

    Directory of Open Access Journals (Sweden)

    Liang Yu

    2017-01-01

    Full Text Available In this paper, a Retinex scale optimized image enhancement algorithm is proposed, which can enhance the micro vision image and eliminate the influence of the uneven illumination. Based on that, a random geometric model of the microstructure of granular materials is established with Monte-Carlo method, the numerical simulation including consolidation process of granular materials is compared with the experimental data. The results have proved that the random field method with Retinex image enhancement algorithm is effective, the image of microstructure of granular materials becomes clear and the contrast ratio is improved, after using Retinex image enhancement algorithm to enhance the CT image. The fidelity of enhanced image is higher than that dealing with other method, which have explained that the algorithm can preserve the microstructure information of the image well. The result of numerical simulation is similar with the one obtained from conventional three axis consolidation test, which proves that the simulation result is reliable.

  8. Assessment of the diffusion battery for determining low concentration submicron aerosol distributions in microelectronics clean rooms

    Energy Technology Data Exchange (ETDEWEB)

    Locke, B.R.; Donovan, R.P.; Ensor, D.S.; Caviness, A.L.

    Traditional particle size determinations for aerosols below 0.1 ..mu..m diameter have been made by both electrical mobility and diffusional methods. Difficulties in determining particle size spectra in the sub-0.1-..mu..m diameter range arise when air from microelectronics manufacturing cleanrooms is sampled because of the low concentration of particulates and the low sampling rates of currently available instruments. Previously reported data indicate that the differential electrical mobility method does not provide reliable aerosol distributions for concentrations below about 1 particle/cm/sup 3/. Laboratory and operating cleanroom measurements with the collimated hole diffusion battery gave particle distributions spanning the range from about 0.001 particles/cm/sup 3/ to 1 x 10/sup 5/ particles/cm/sup 3/. The low concentration particle spectra in cleanrooms at rest showed peak aerosol concentrations at about 0.1 ..mu..m with few particles at sizes below this peak.

  9. Measurements of Submicron Particle Adsorption and Particle Film Elasticity at Oil-Water Interfaces.

    Science.gov (United States)

    Manga, Mohamed S; Hunter, Timothy N; Cayre, Olivier J; York, David W; Reichert, Matthew D; Anna, Shelly L; Walker, Lynn M; Williams, Richard A; Biggs, Simon R

    2016-05-03

    The influence of particle adsorption on liquid/liquid interfacial tension is not well understood, and much previous research has suggested conflicting behaviors. In this paper we investigate the surface activity and adsorption kinetics of charge stabilized and pH-responsive polymer stabilized colloids at oil/water interfaces using two tensiometry techniques: (i) pendant drop and (ii) microtensiometer. We found, using both techniques, that charge stabilized particles had little or no influence on the (dynamic) interfacial tension, although dense silica particles affected the "apparent" measured tension in the pendent drop, due to gravity driven elongation of the droplet profile. Nevertheless, this apparent change additionally allowed the study of adsorption kinetics, which was related qualitatively between particle systems by estimated diffusion coefficients. Significant and real interfacial tension responses were measured using ∼53 nm core-shell latex particles with a pH-responsive polymer stabilizer of poly(methyl methacrylate)-b-poly(2-(dimethylamino)ethyl methacrylate) (pMMA-b-pDMAEMA) diblock copolymer. At pH 2, where the polymer is strongly charged, behavior was similar to that of the bare charge-stabilized particles, showing little change in the interfacial tension. At pH 10, where the polymer is discharged and poorly soluble in water, a significant decrease in the measured interfacial tension commensurate with strong adsorption at the oil-water interface was seen, which was similar in magnitude to the surface activity of the free polymer. These results were both confirmed through droplet profile and microtensiometry experiments. Dilational elasticity measurements were also performed by oscillation of the droplet; again, changes in interfacial tension with droplet oscillation were only seen with the responsive particles at pH 10. Frequency sweeps were performed to ascertain the dilational elasticity modulus, with measured values being significantly higher

  10. Experimental Investigations of the Physical and Optical Properties of Individual Micron/Submicron-Size Dust Grains in Astrophysical Environments

    Science.gov (United States)

    Abbas, M. M.; Tankosic, D.; LeClair, A.

    2014-01-01

    Dust grains constitute a significant component of matter in the universe, and play an important and crucial role in the formation and evolution of the stellar/planetary systems in interstellar dust clouds. Knowledge of physical and optical properties of dust grains is required for understanding of a variety of processes in astrophysical and planetary environments. The currently available and generally employed data on the properties of dust grains is based on bulk materials, with analytical models employed to deduce the corresponding values for individual small micron/submicron-size dust grains. However, it has been well-recognized over a long period, that the properties of individual smallsize dust grains may be very different from those deduced from bulk materials. This has been validated by a series of experimental investigations carried out over the last few years, on a laboratory facility based on an Electrodynamic Balance at NASA, which permits levitation of single small-size dust grains of desired composition and size, in vacuum, in simulated space environments. In this paper, we present a brief review of the results of a series of selected investigations carried out on the analogs of interstellar and planetary dust grains, as well as dust grains obtained by Apollo-l1-17 lunar missions. The selected investigations, with analytical results and discussions, include: (a) Direct measurements of radiation on individual dust grains (b) Rotation and alignments of dust grains by radiative torque (c) Charging properties of dust grains by: (i) UV Photo-electric emissions (ii) Electron Impact. The results from these experiments are examined in the light of the current theories of the processes involved.

  11. Oxygenated organic functional groups and their sources in single and submicron organic particles in MILAGRO 2006 campaign

    Directory of Open Access Journals (Sweden)

    S. Liu

    2009-09-01

    Full Text Available Fourier Transform Infrared (FTIR and X-ray Fluorescence (XRF were used to measure organic functional groups and elements of submicron particles collected during MILAGRO in March 2006 on three platforms: the Mexico City urban area (SIMAT, the high altitude site at 4010 m (Altzomoni, and the NCAR C130 aircraft. Scanning Transmission X-ray Microscopy (STXM and Near-Edge X-ray Absorption Fine Structure (NEXAFS were applied to single particle organic functional group abundance analysis of particles simultaneously collected at SIMAT and C130. Correlations of elemental concentrations showed different groups of source-related elements at SIMAT, Altzomoni, and C130, suggesting different processes affecting the air masses sampled at the three platforms. Cluster analysis resulted in seven distinct clusters of FTIR spectra, with the last three clusters consisting of spectra collected almost exclusively on the C130 platform, reflecting the variety of sources contributing to C130 samples. Positive Matrix Factorization (PMF of STXM-NEXAFS spectra identified three main factors representing soot, secondary, and biomass burning type spectra. PMF of FTIR spectra resulted in two fossil fuel combustion factors and one biomass burning factor, the former representative of source regions to the northeast and southwest of SIMAT. Alkane, carboxylic acid, amine, and alcohol functional groups were mainly associated with combustion related sources, while non-acid carbonyl groups were likely from biomass burning events. The majority of OM and O/C was attributed to combustion sources, although no distinction between direct emissions and atmospherically processed OM could be identified.

  12. Evaluation of traffic exhaust contributions to ambient carbonaceous submicron particulate matter in an urban roadside environment in Hong Kong

    Science.gov (United States)

    Lee, Berto Paul; Kwok Keung Louie, Peter; Luk, Connie; Keung Chan, Chak

    2017-12-01

    Road traffic has significant impacts on air quality particularly in densely urbanized and populated areas where vehicle emissions are a major local source of ambient particulate matter. Engine type (i.e., fuel use) significantly impacts the chemical characteristics of tailpipe emission, and thus the distribution of engine types in traffic impacts measured ambient concentrations. This study provides an estimation of the contribution of vehicles powered by different fuels (gasoline, diesel, LPG) to carbonaceous submicron aerosol mass (PM1) based on ambient aerosol mass spectrometer (AMS) and elemental carbon (EC) measurements and vehicle count data in an urban inner city environment in Hong Kong with the aim to gauge the importance of different engine types to particulate matter burdens in a typical urban street canyon. On an average per-vehicle basis, gasoline vehicles emitted 75 and 93 % more organics than diesel and LPG vehicles, respectively, while EC emissions from diesel vehicles were 45 % higher than those from gasoline vehicles. LPG vehicles showed no appreciable contributions to EC and thus overall represented a small contributor to traffic-related primary ambient PM1 despite their high abundance (˜ 30 %) in the traffic mix. Total carbonaceous particle mass contributions to ambient PM1 from diesel engines were only marginally higher (˜ 4 %) than those from gasoline engines, which is likely an effect of recently introduced control strategies targeted at commercial vehicles and buses. Overall, gasoline vehicles contributed 1.2 µg m-3 of EC and 1.1 µ m-3 of organics, LPG vehicles 0.6 µg m-3 of organics and diesel vehicles 2.0 µg m-3 of EC and 0.7 µg m-3 of organics to ambient carbonaceous PM1.

  13. Evaluation of traffic exhaust contributions to ambient carbonaceous submicron particulate matter in an urban roadside environment in Hong Kong

    Directory of Open Access Journals (Sweden)

    B. P. Lee

    2017-12-01

    Full Text Available Road traffic has significant impacts on air quality particularly in densely urbanized and populated areas where vehicle emissions are a major local source of ambient particulate matter. Engine type (i.e., fuel use significantly impacts the chemical characteristics of tailpipe emission, and thus the distribution of engine types in traffic impacts measured ambient concentrations. This study provides an estimation of the contribution of vehicles powered by different fuels (gasoline, diesel, LPG to carbonaceous submicron aerosol mass (PM1 based on ambient aerosol mass spectrometer (AMS and elemental carbon (EC measurements and vehicle count data in an urban inner city environment in Hong Kong with the aim to gauge the importance of different engine types to particulate matter burdens in a typical urban street canyon. On an average per-vehicle basis, gasoline vehicles emitted 75 and 93 % more organics than diesel and LPG vehicles, respectively, while EC emissions from diesel vehicles were 45 % higher than those from gasoline vehicles. LPG vehicles showed no appreciable contributions to EC and thus overall represented a small contributor to traffic-related primary ambient PM1 despite their high abundance (∼ 30 % in the traffic mix. Total carbonaceous particle mass contributions to ambient PM1 from diesel engines were only marginally higher (∼ 4 % than those from gasoline engines, which is likely an effect of recently introduced control strategies targeted at commercial vehicles and buses. Overall, gasoline vehicles contributed 1.2 µg m−3 of EC and 1.1 µ m−3 of organics, LPG vehicles 0.6 µg m−3 of organics and diesel vehicles 2.0 µg m−3 of EC and 0.7 µg m−3 of organics to ambient carbonaceous PM1.

  14. Annual trends in occurrence of submicron particles in ambient air and health risk posed by particle bound metals.

    Science.gov (United States)

    Izhar, Saifi; Goel, Anubha; Chakraborty, Abhishek; Gupta, Tarun

    2016-03-01

    Risk analysis is highly important in toxicology and public health studies. Health risk related to exposure to toxic metals of PM1 was assessed. Concentrations of 13 heavy metals, adsorbed to submicron particulate matter PM1 were experimentally examined but only 12 metals were found at detectable levels inside IIT Kanpur campus in 2008-2009 for all months excluding June and October. A total of 90 samples collected for 8 h sampling time by a single stage round nozzle, grease impaction substrate based impactor type PM1 sampler were analysed by ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometry). Results showed daily average PM1 concentration is 102.46 ± 35.9 μg/m(3) and metal concentration followed the trend: Ca > Fe > Mg > Zn > Pb > Cu > Cr > Ni > Se > Cd > V > As. Contamination level assessment using geo-accumulation index showed Ca, Fe and Mg exhibited non contamination whereas metals like Cr, Zn, As, Cd, Pb, Se, Ni and Cu exhibited ranges from moderate to extreme contamination. Ingestion is found to be the major exposure pathway for heavy metals. Non-carcinogenic health risk assessment for Pb, Cd and Cr (HI > 1) signified strong chances of adverse impact on children whereas adults are well under safe limit. Cancer Risk for adults and children followed the same decreasing order, Cr(VI)>Cd > Ni > As > Pb. It was found to be higher than permissible limits (10(-6)) for adults and children both. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Effects of submicron ammonium sulfate particles on the growth and yield of komatsuna (Brassica rapa L. var. perviridis)

    Science.gov (United States)

    Motai, Akira; Nakaba, Satoshi; Lenggoro, I. Wuled; Watanabe, Makoto; Wada, Yoshiharu; Izuta, Takeshi

    2017-11-01

    The aim of this study was to determine the effects of submicron ammonium sulfate (AS) particles on komatsuna (Brassica rapa L. cv. Hakkei) plants. First, we optimized a leaf-washing method to measure the amount of AS particles deposited on the leaf surface of the plants. Then, we used this method to determine the retention time of particles deposited on the leaf surface of the plants. We also investigated the effects of AS particles on the growth and yield of the plants. Almost all the AS particles deposited on the leaf surface were removed within 1 min washing time with ultrapure water, and ion leaching from the leaf was relatively slow but continuous during the leaf-washing procedure. On the basis of these results, we determined that 1 min was a suitable washing time to remove most of the AS particles while minimizing the influence of ion leaching from the leaf. The amount of particulate SO42- deposited on the leaf surface decreased over time, probably because AS particles deposited on the leaf surface deliquesced, allowing ions such as SO42- in the deliquescence solution to be absorbed into the leaf. The plants were grown and exposed to AS particles for 16 days in naturally lit phytotrons. The daily mean increase in the concentration of SO42- in PM2.5 by the exposure to AS particles was 22.5 μg m-3 in the phytotrons. The growth and yield of the plants were significantly reduced by the exposure to AS particles. The exposure to AS particles did not affect the leaf concentrations of nitrogen and chlorophyll, but significantly reduced stomatal conductance. Therefore, stomatal closure is one of the reasons for the AS particle-induced reductions in the growth and yield of komatsuna plants.

  16. Imaging of vaporised sub-micron phase change contrast agents with high frame rate ultrasound and optics.

    Science.gov (United States)

    Lin, Shengtao; Zhang, Ge; Jamburidze, Akaki; Chee, Melisse; Leow, Chee Hau; Garbin, Valeria; Tang, Meng-Xing

    2018-01-31

    Phase-change ultrasound contrast agent (PCCA), or nanodroplet shows promises as an alternative to conventional microbubble agent over a wide range of diagnostic applications. In the meantime, high-frame-rate (HFR) ultrasound imaging with microbubbles enables unprecedentedly temporal resolution compared to traditional contrast-enhanced ultrasound imaging. The combination of HFR ultrasound imaging and PCCAs can offer opportunities to observe and better understand PCCA behaviour after vaporisation capturing the fast phenomenon at a high temporal resolution. In this study, we utilised HFR ultrasound at frame rates in the kilohertz range (5-20 kHz) to image the native and size-selected PCCA populations immediately after vaporisation in vitro with clinical acoustic parameters. The size-selected PCCAs through filtration are shown to preserve submicron-sized (mean diameter < 200 nm) population without micron-sized outliers (> 1 µm) that are originally from the native PCCA emulsion. The results demonstrate imaging signals with different amplitude and temporal features compared to that of microbubbles. Compared with microbubbles, both B-mode and Pulse-Inversion (PI) signals from vaporised PCCA populations were reduced significantly in the first tens of milliseconds, while only B-mode signals from the PCCAs recovered during the next 400 ms, suggesting significant changes to the size distribution of PCCAs after vaporisation. It is also shown that such recovery in signal over time is not evident when using size-selective PCCAs. Furthermore, it was found that signals from the vaporised PCCA populations are affected by the amplitude and frame rate of the HFR ultrasound imaging. Using high-speed optical camera observation (30 kHz), we observed the particle size change in the vaporised PCCA populations exposed to the HFR ultrasound imaging pulses. These findings can benefit the understandings of PCCA behaviour under HFR ultrasound imaging. © 2018 Institute of Physics and

  17. 22 CFR 40.91 - Certain aliens previously removed.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a result...

  18. Bilateral orbital infarction and retinal detachment in a previously ...

    African Journals Online (AJOL)

    Bone infarction involving the orbit in sickle cell disease is not common. Bilateral orbital infarction in a previously undiagnosed sickle cell hemoglobinopathy has not been previously reported. In this report, we present a case of an 11‑year‑old previously undiagnosed sickle cell disease Nigerian girl with severe acute bilateral ...

  19. Biological scaling and physics

    Indian Academy of Sciences (India)

    Unknown

    Kleiber scaling in the previous paragraph has the growth in Q kept smaller in spite of the high power dependence on R in eq. (1). 4. Conclusions. The arguments that have been advanced so far by pre- vious authors swing to extremes at either end. Thus, the rich variety and diversity in biology, including of scaling exponents ...

  20. Seasonal characterization of submicron aerosol chemical composition and organic aerosol sources in the southeastern United States: Atlanta, Georgia,and Look Rock, Tennessee

    Directory of Open Access Journals (Sweden)

    S. H. Budisulistiorini

    2016-04-01

    Full Text Available A year-long near-real-time characterization of non-refractory submicron aerosol (NR-PM1 was conducted at an urban (Atlanta, Georgia, in 2012 and rural (Look Rock, Tennessee, in 2013 site in the southeastern US using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM collocated with established air-monitoring network measurements. Seasonal variations in organic aerosol (OA and inorganic aerosol species are attributed to meteorological conditions as well as anthropogenic and biogenic emissions in this region. The highest concentrations of NR-PM1 were observed during winter and fall seasons at the urban site and during spring and summer at the rural site. Across all seasons and at both sites, NR-PM1 was composed largely of OA (up to 76 % and sulfate (up to 31 %. Six distinct OA sources were resolved by positive matrix factorization applied to the ACSM organic mass spectral data collected from the two sites over the 1 year of near-continuous measurements at each site: hydrocarbon-like OA (HOA, biomass burning OA (BBOA, semi-volatile oxygenated OA (SV-OOA, low-volatility oxygenated OA (LV-OOA, isoprene-derived epoxydiols (IEPOX OA (IEPOX-OA and 91Fac (a factor dominated by a distinct ion at m∕z 91 fragment ion previously observed in biogenic influenced areas. LV-OOA was observed throughout the year at both sites and contributed up to 66 % of total OA mass. HOA was observed during the entire year only at the urban site (on average 21 % of OA mass. BBOA (15–33 % of OA mass was observed during winter and fall, likely dominated by local residential wood burning emission. Although SV-OOA contributes quite significantly ( ∼  27 %, it was observed only at the urban site during colder seasons. IEPOX-OA was a major component (27–41 % of OA at both sites, particularly in spring and summer. An ion fragment at m∕z 75 is well correlated with the m∕z 82 ion associated with the aerosol mass spectrum of IEPOX

  1. Second-hand smoke exposure generated by new electronic devices (IQOS® and e-cigs) and traditional cigarettes: submicron particle behaviour in human respiratory system.

    Science.gov (United States)

    Protano, C; Manigrasso, M; Avino, P; Sernia, S; Vitali, M

    2016-01-01

    Passive exposure profiles to submicronic particles (SMPs, 5.6-560 nm) of traditional cigarettes and new electronic commercial devices (e-cig and IQOS®, a new heat-not-burn smoking device) were compared. During smoking, SMPs released by traditional cigarettes resulted four-times higher than those released by electronic and heat-not-burn devices and remained high for at least one hour, while SMPs values returned immediately similar to background for electronic and heat-not-burn devices. In all experiments, approximately half of SMPs resulted so small to reach the alveolar region.

  2. Do previous experience and geographic proximity matter? Possible predictors for diagnosing Adjustment disorder vs. PTSD.

    Science.gov (United States)

    Mahat-Shamir, Michal; Ring, Lia; Hamama-Raz, Yaira; Ben-Ezra, Menachem; Pitcho-Prelorentzos, Shani; David, Udi Y; Zaken, Adi; Lavenda, Osnat

    2017-12-01

    The minority of people who have experienced a traumatic event and were diagnosed as either suffering from PTSD or from Adjustment disorder, may suggest that victims of a traumatic event vary in risk factors for the disorders. The current research aimed at examining the association between reports of Adjustment disorder and PTSD symptoms (In accordance with the proposed revisions of the ICD-11) and several vulnerability variables: previous traumatic event, previous stressful event and physical proximity to the terror attack. Using an online survey, 379 adult participants were recruited, and filled out Adjustment disorder, PTSD symptomatology scales, as well as a previous exposure, magnitude of exposure and death anxiety scales. Findings revealed that previous experience of traumatic events was a significant predictor associated with both PTSD and Adjustment disorder symptoms. Previous experience of stressful events was a significant predictor associated with Adjustment disorder alone. Physical proximity to the site of the attack was a significant predictor associated with PTSD symptoms but not Adjustment disorder symptoms. The importance of previous traumatic events, previous stressful events and physical proximity to the terror attack as factors which are associated with Adjustment disorder and PTSD symptomatology is discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Simulation of Flow and Transport at the Micro (Pore) Scale

    Energy Technology Data Exchange (ETDEWEB)

    Trebotich, D; Miller, G H

    2007-04-05

    An important problem in porous media involves the ability of micron and submicron-sized biological particles such as viruses or bacteria to move in groundwater systems through geologic media characterized by rock or mixed gravel, clay and sand materials. Current simulation capabilities require properly upscaled (continuum) models of colloidal filtration and adsorption to augment existing theories of fluid flow and chemical transport. Practical models typically address flow and transport behavior in aquifers over distances of 1 to 10 km where, for example, fluid momentum balance is governed by the simple Darcy's Law as a function of a pressure gradient, elevation gradient and a medium-dependent permeability parameter. In addition to fluid advection, there are multiple transport processes occurring in these systems including diffusion, dispersion and chemical interactions with solids or other aqueous chemical species. Particle transport is typically modeled in the same way as dissolved species, except that additional loss terms are incorporated to model particle filtration (physical interception), adsorption (chemical interception) and inactivation. Proper resolution of these processes at the porous medium continuum scale constitutes an important closure problem in subsurface science. We present a new simulation capability based on enabling technologies developed for microfluidics applications to model transport of colloidal-sized particles at the microscale, with relevance to the pore scale in geophysical subsurface systems. Particulate is represented by a bead-rod polymer model and is fully-coupled to a Newtonian solvent described by Navier-Stokes. Finite differences are used to discretize the interior of the domain; a Cartesian grid embedded boundary/volume-of-fluid method is used near boundaries and interfaces. This approach to complex geometry is amenable to direct simulation on grids obtained from surface extractions of tomographic image data. Short

  4. A comparative study of submicron particle sizing platforms: accuracy, precision and resolution analysis of polydisperse particle size distributions.

    Science.gov (United States)

    Anderson, Will; Kozak, Darby; Coleman, Victoria A; Jämting, Åsa K; Trau, Matt

    2013-09-01

    The particle size distribution (PSD) of a polydisperse or multimodal system can often be difficult to obtain due to the inherent limitations in established measurement techniques. For this reason, the resolution, accuracy and precision of three new and one established, commercially available and fundamentally different particle size analysis platforms were compared by measuring both individual and a mixed sample of monodisperse, sub-micron (220, 330, and 410 nm - nominal modal size) polystyrene particles. The platforms compared were the qNano Tunable Resistive Pulse Sensor, Nanosight LM10 Particle Tracking Analysis System, the CPS Instruments's UHR24000 Disc Centrifuge, and the routinely used Malvern Zetasizer Nano ZS Dynamic Light Scattering system. All measurements were subjected to a peak detection algorithm so that the detected particle populations could be compared to 'reference' Transmission Electron Microscope measurements of the individual particle samples. Only the Tunable Resistive Pulse Sensor and Disc Centrifuge platforms provided the resolution required to resolve all three particle populations present in the mixed 'multimodal' particle sample. In contrast, the light scattering based Particle Tracking Analysis and Dynamic Light Scattering platforms were only able to detect a single population of particles corresponding to either the largest (410 nm) or smallest (220 nm) particles in the multimodal sample, respectively. When the particle sets were measured separately (monomodal) each platform was able to resolve and accurately obtain a mean particle size within 10% of the Transmission Electron Microscope reference values. However, the broadness of the PSD measured in the monomodal samples deviated greatly, with coefficients of variation being ~2-6-fold larger than the TEM measurements across all four platforms. The large variation in the PSDs obtained from these four, fundamentally different platforms, indicates that great care must still be taken in

  5. Trends and sources of ozone and sub-micron aerosols at the Mt. Bachelor Observatory during 2004-2015

    Science.gov (United States)

    Zhang, L.; Jaffe, D. A.; Hee, J.

    2016-12-01

    Tropospheric ozone (O3) and airborne particles have significant impacts on human health and the environment. The Mt. Bachelor Observatory (MBO, 2.8 km a.s.l.) in Central Oregon, USA, now has one of the longest continuous free tropospheric records of O3, CO and aerosols in North America. In this study, we report on sources and trends of O3 and sub-micron aerosol scattering at MBO for 2004-2015. For O3, the seasonal cycle shows a bimodal pattern with peaks in April and July, while aerosol scattering (σsp) is lognormally distributed with a very high average in August and a smaller maximum in May. Mean O3 concentrations show a positive and significant trend in all seasons except winter, with an increase of approximately 0.6 ppb/year. This trend appears to be driven by Asian pollution in spring and regional wildfires in summer. For aerosol scattering, we see a significant increase only in summer, driven by recent increases in wildfire activity in the western US. Monthly criteria for isolating free troposphere (FT) and boundary layer (BL) air masses at MBO were obtained based on comparison of MBO water vapor (WV) distributions to those of Salem (SLE) and Medford (MFR), Oregon at equivalent pressure level. In all seasons, FT O3 is, on average, higher than BL O3, but the seasonal patterns are rather similar. For σsp the mean in summer is significantly higher than the FT, indicating the importance of regional wildfire smoke. We have identified four types of air masses that impact O3, CO and aerosols: Asian long range transport (ALRT), regional wildfires, regional industrial pollution, and upper troposphere and lower stratosphere (UTLS) intrusions. Over the 12 years of observations, we have identified 204 individual plume events based on the criteria of 8 consecutive polluted hours with elevated σsp, O3 or CO. Multi-pollutant correlations and backward trajectories were used to differentiate background source categories. A series of enhancement ratios (ERs) including

  6. Trends and sources of ozone and sub-micron aerosols at the Mt. Bachelor Observatory (MBO) during 2004-2015

    Science.gov (United States)

    Zhang, Lei; Jaffe, Daniel A.

    2017-09-01

    In this paper, we report the climatology of tropospheric ozone (O3) and sub-micron aerosol scattering at the Mt. Bachelor Observatory (MBO, 2.8 km asl) in central Oregon, USA, during 2004-2015. The seasonal cycle for O3 showed a bimodal pattern with peaks in April and July, while aerosol scattering (σsp) was lognormally distributed with a very high peak in August and a smaller peak in May. The mean O3 concentrations showed positive and significant trends in all seasons except winter, with a slope of 0.6-0.8 ppbv yr-1. Monthly criteria for isolating free tropospheric (FT) and boundary layer influenced (BLI) air masses at MBO were obtained based on comparison of MBO water vapor (WV) distributions to those of Salem (SLE) and Medford (MFR), Oregon, at equivalent pressure level. In all seasons, FT O3 was, on average, higher than BLI O3, but the seasonal patterns were rather similar. For σsp the FT mean in spring was higher, but the BLI mean in summer was significantly higher, indicating the importance of regional wildfire smoke. To better understand the causes for the seasonal and interannual trends at MBO, we identified four major categories of air masses that impact O3, carbon monoxide (CO) and aerosols: upper troposphere and lower stratosphere (UTLS) O3 intrusion, Asian long-range transport (ALRT), Arctic air pollution (AAP) and plumes from the Pacific Northwest region (PNW). ALRT and PNW plumes can be further divided into wildfires (WF), industrial pollution (IP) and mineral dust (MD). Over the 12 years of observations, 177 individual plume events have been identified. Enhancement ratios (ERs) and Ångström exponents (AEs) of aerosols were calculated for all events. The lowest slope of Δσsp/ΔO3 is a unique feature of UTLS events. PNW-WF events have the highest averages for Δσsp/ΔCO, Δσsp/ΔO3 and Δσsp/ΔNOy compared to other events. These ERs decrease during long-range transport due to the shorter residence time of aerosols compared to the other

  7. Seasonal variations in high time-resolved chemical compositions, sources, and evolution of atmospheric submicron aerosols in the megacity Beijing

    Science.gov (United States)

    Hu, Wei; Hu, Min; Hu, Wei-Wei; Zheng, Jing; Chen, Chen; Wu, Yusheng; Guo, Song

    2017-08-01

    A severe regional haze problem in the megacity Beijing and surrounding areas, caused by fast formation and growth of fine particles, has attracted much attention in recent years. In order to investigate the secondary formation and aging process of urban aerosols, four intensive campaigns were conducted in four seasons between March 2012 and March 2013 at an urban site in Beijing (116.31° E, 37.99° N). An Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) was deployed to measure non-refractory chemical components of submicron particulate matter (NR-PM1). The average mass concentrations of PM1 (NR-PM1+black carbon) were 45.1 ± 45.8, 37.5 ± 31.0, 41.3 ± 42.7, and 81.7 ± 72.4 µg m-3 in spring, summer, autumn, and winter, respectively. Organic aerosol (OA) was the most abundant component in PM1, accounting for 31, 33, 44, and 36 % seasonally, and secondary inorganic aerosol (SNA, sum of sulfate, nitrate, and ammonium) accounted for 59, 57, 43, and 55 % of PM1 correspondingly. Based on the application of positive matrix factorization (PMF), the sources of OA were obtained, including the primary ones of hydrocarbon-like (HOA), cooking (COA), biomass burning OA (BBOA) and coal combustion OA (CCOA), and secondary component oxygenated OA (OOA). OOA, which can be split into more-oxidized (MO-OOA) and less-oxidized OOA (LO-OOA), accounted for 49, 69, 47, and 50 % in four seasons, respectively. Totally, the fraction of secondary components (OOA+SNA) contributed about 60-80 % to PM1, suggesting that secondary formation played an important role in the PM pollution in Beijing, and primary sources were also non-negligible. The evolution process of OA in different seasons was investigated with multiple metrics and tools. The average carbon oxidation states and other metrics show that the oxidation state of OA was the highest in summer, probably due to both strong photochemical and aqueous-phase oxidations. It was indicated by the good correlations

  8. Adolescents previously involved in Satanism experiencing mental health problems

    OpenAIRE

    H. Heathcote

    1999-01-01

    No research has previously been done regarding the phenomenon of adolescents who have previously been involved in Satanism and who experience obstacles in their strive for mental health. Adolescents previously involved in Satanism present behavioral problems like aggressive outbursts, depression, “ psychosis” or suicide attempts, that could lead to suicide. In the phenomenonanalysis semi-structured, phenomenological interviews were performed with the respondents and their parents. The respond...

  9. Submicron Systems Architecture

    Science.gov (United States)

    1983-11-01

    circuit simulator, and will not treat elements such as ideal opamps , current controlled current sources, ideal transformers, or nonlinear elements that...transistors, or resistive opens or shorts. We have implemented a faul simulator FMOSSIM based on this algorithm. The capabilities and the performance of this...sequence to improve its fault coverag. open or stuck-closed transistors, or resistive opens Such a tool is invaluable for developing test pat- or shorts

  10. Submicron Systems Architecture Project

    Science.gov (United States)

    1990-10-01

    Thompson, Bozena, Frederick B Thompson, and Tai-Ping Ho I 5035:TR:82 $9.00 Type Inference in a Declarationless, Object-Oriented Language, MS Thesis Holstege ...Declarationless, Object-Oriented Language, MS Thesis Holstege , Eric 5034:TR:82 $12.OOHybrid Processing, PhD Thesis Carroll, Chris 5033:TR:82 $4.00 MOSSIM II: A...Oriented Language, MS Thesis Holstege , Eric -- 5034:TR:82 $12.00 Hybrid Processing, PhD Thesis Carroll, Chris --.. 5033:TR:82 $4.00 MOSSIM II: A Switch

  11. Submicron Silicon MOSFET

    Science.gov (United States)

    Daud, T.

    1986-01-01

    Process for making metal-oxide/semiconductor field-effect transistors (MOSFET's) results in gate-channel lengths of only few hundred angstroms about 100 times as small as state-of-the-art devices. Gates must be shortened to develop faster MOSFET's; proposed fabrication process used to study effects of size reduction in MOS devices and eventually to build practical threedimensional structures.

  12. The Modification of Polymer Surfaces and the Fabrication of Submicron- Scale Functionalized Structures by Deep-UV and Electron Beam Lithography

    Science.gov (United States)

    1993-06-10

    studied under the fluorescence microscope . Accelerating voltages in the range 5 to 40 kV and dosages between I and 75 iC cm2 were studied. For all dosages...avidin-fluorescein 3. Figure 3 shows the patterns visualized under a fluorescence microscope . Two control experiments were performed. A...under the fluorescence microscope indicating that there was little non-specific absorption of either amino-biotin or avidin-fluorescein conjugate on the

  13. Influence of Mechanical Loading on the Integrity and Performance of Energy Harvesting and Storage Materials at the Micron and Submicron Scales

    Science.gov (United States)

    2016-04-01

    including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing ...ZnO TCO layer, an 1 μm thick amorphous Si p-n junction diode, a 0.1 μm thick conductive polyimide Kapton ™ layer acting as the bottom electrode, and a

  14. Characterization of size, morphology and elemental composition of nano-, submicron, and micron particles of street dust separated using field-flow fractionation in a rotating coiled column.

    Science.gov (United States)

    Fedotov, Petr S; Ermolin, Mikhail S; Karandashev, Vasily K; Ladonin, Dmitry V

    2014-12-01

    For the first time, nano- and submicron particles of street dust have been separated, weighted, and analyzed. A novel technique, sedimentation field-flow fractionation in a rotating coiled column, was applied to the fractionation of dust samples with water being used as a carrier fluid. The size and morphology of particles in the separated fractions were characterized by electronic microscopy before digestion and the determination of the concentration of elements by ICP-AES and ICP-MS. The elements that may be of anthropogenic origin (Zn, Cr, Ni, Cu, Cd, Sn, Pb) were found to concentrate mainly in particles present only about 0.1 mass% of the sample they are of special concern due to their increased mobility and ability to penetrate into the deepest alveolar area of the lungs. For rare earth elements (La, Ce, Pr, Nd, Sm) that are evidently of natural source and may be found in soil minerals, in contrary, higher concentrations were observed in large particles (10-100 μm). Sc was an exception that needs further studies. The proposed approach to the fractionation and analysis of nano-, submicron, and micron particles can be a powerful tool for risk assessment related to toxic elements in dust, ash, and other particulate environmental samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Improved Light Conversion Efficiency Of Dye-Sensitized Solar Cell By Dispersing Submicron-Sized Granules Into The Nano-Sized TiO2 Layer

    Directory of Open Access Journals (Sweden)

    Song S.A.

    2015-06-01

    Full Text Available In this work, TiO2 nanoparticles and submicron-sized granules were synthesized by a hydrothermal method and spray pyrolysis, respectively. Submicron-sized granules were dispersed into the nano-sized TiO2 layer to improve the light conversion efficiency. Granules showed better light scattering, but lower in terms of the dye-loading quantity and recombination resistance compared with nanoparticles. Consequently, the nano-sized TiO2 layer had higher cell efficiency than the granulized TiO2 layer. When dispersed granules into the nanoparticle layer, the light scattering was enhanced without the loss of dye-loading quantities. The dispersion of granulized TiO2 led to increase the cell efficiency up to 6.51%, which was about 5.2 % higher than that of the electrode consisting of only TiO2 nanoparticles. Finally, the optimal hydrothermal temperature and dispersing quantity of granules were found to be 200°C and 20 wt%, respectively.

  16. Hydrothermal Synthesis Au-Bi2Te3 Nanocomposite Thermoelectric Film with a Hierarchical Sub-Micron Antireflection Quasi-Periodic Structure

    Directory of Open Access Journals (Sweden)

    Junlong Tian

    2015-06-01

    Full Text Available In this work, Au-Bi2Te3 nanocomposite thermoelectric film with a hierarchical sub-micron antireflection quasi-periodic structure was synthesized via a low-temperature chemical route using Troides helena (Linnaeus forewing (T_FW as the biomimetic template. This method combines chemosynthesis with biomimetic techniques, without the requirement of expensive equipment and energy intensive processes. The microstructure and the morphology of the Au-Bi2Te3 nanocomposite thermoelectric film was analyzed by X-ray diffraction (XRD, field-emission scanning-electron microscopy (FESEM, and transmission electron microscopy (TEM. Coupled the plasmon resonances of the Au nanoparticles with the hierarchical sub-micron antireflection quasi-periodic structure, the Au-Bi2Te3 nanocomposite thermoelectric film possesses an effective infrared absorption and infrared photothermal conversion performance. Based on the finite difference time domain method and the Joule effect, the heat generation and the heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film were studied. The heterogeneity of heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film opens up a novel promising technique for generating thermoelectric power under illumination.

  17. Sub-micron resolution surface plasmon resonance imaging enabled by nanohole arrays with surrounding Bragg mirrors for enhanced sensitivity and isolation.

    Science.gov (United States)

    Lindquist, Nathan C; Lesuffleur, Antoine; Im, Hyungsoon; Oh, Sang-Hyun

    2009-02-07

    We present nanohole arrays in thin gold films as sub-micron resolution surface plasmon resonance (SPR) imaging pixels in a microarray format. With SPR imaging, the resolution is not limited by diffraction, but by the propagation of surface plasmon waves to adjacent sensing areas, or nanohole arrays, causing unwanted interference. For ultimate scalability, several issues need to be addressed, including: (1) as several nanohole arrays are brought close to each other, surface plasmon interference introduces large sources of error; and (2) as the size of the nanohole array is reduced, i.e. fewer holes, detection sensitivity suffers. To address these scalability issues, we surround each biosensing pixel (a 3-by-3 nanohole array) with plasmonic Bragg mirrors, blocking interference between adjacent SPR sensing pixels for high-density packing, while maintaining the sensitivity of a 50 x larger footprint pixel (a 16-by-16 nanohole array). We measure real-time, label-free streptavidin-biotin binding kinetics with a microarray of 600 sub-micron biosensing pixels at a packing density of more than 10(7) per cm(2).

  18. 14 CFR 47.33 - Aircraft not previously registered anywhere.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Aircraft not previously registered anywhere... TRANSPORTATION AIRCRAFT AIRCRAFT REGISTRATION Certificates of Aircraft Registration § 47.33 Aircraft not previously registered anywhere. (a) A person who is the owner of an aircraft that has not been registered...

  19. 2 CFR 220.40 - Relationship to previous issuance.

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Relationship to previous issuance. 220.40 Section 220.40 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR EDUCATIONAL INSTITUTIONS (OMB CIRCULAR A-21) § 220.40 Relationship to previous issuance. (a...

  20. 2 CFR 230.45 - Relationship to previous issuance.

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Relationship to previous issuance. 230.45 Section 230.45 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR NON-PROFIT ORGANIZATIONS (OMB CIRCULAR A-122) § 230.45 Relationship to previous issuance. (a...

  1. 2 CFR 1.215 - Relationship to previous issuances.

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Relationship to previous issuances. 1.215 Section 1.215 Grants and Agreements ABOUT TITLE 2 OF THE CODE OF FEDERAL REGULATIONS AND SUBTITLE A Introduction toSubtitle A § 1.215 Relationship to previous issuances. Although some of the guidance was...

  2. Large Bowel Obstruction Caused by Adhesions without Previous ...

    African Journals Online (AJOL)

    Background: Large bowel obstruction is rarely caused by adhesions. To our knowledge, the few cases reported in literature are secondary to previous abdomino-pelvic surgery, and are in female patients. Case Reports: We report two cases of large bowel obstruction due to adhesions in males with no previous abdominal ...

  3. 75 FR 76056 - FEDERAL REGISTER CITATION OF PREVIOUS ANNOUNCEMENT:

    Science.gov (United States)

    2010-12-07

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Sunshine Act Meeting FEDERAL REGISTER CITATION OF PREVIOUS ANNOUNCEMENT: STATUS: Closed meeting. PLACE: 100 F Street, NE., Washington, DC. DATE AND TIME OF PREVIOUSLY ANNOUNCED MEETING: Thursday...

  4. Induction of labour in women with one previous caesarean section.

    Science.gov (United States)

    Gupta, P; Elmardi, A; Bathula, U; Chandru, S; Charlesworth, D

    2011-01-01

    We conducted a postal survey of NHS obstetric consultants working in England regarding their own practice and views on induction of labour in women with one previous caesarean section. Out of 480 consultant obstetricians across England, 322 replied, giving a response rate of 67%. Our survey has revealed a wide variation in practice of consultants across England, regarding induction of labour at term or post-term in women with one previous caesarean section. Hence, we feel that there is a need for a national audit of induction of labour in women with one previous caesarean section, with uterine rupture following induction of labour in such women as an auditable standard.

  5. Adolescents previously involved in Satanism experiencing mental health problems

    Directory of Open Access Journals (Sweden)

    H Heathcote

    1999-09-01

    Full Text Available No research has previously been done regarding the phenomenon of adolescents who have previously been involved in Satanism and who experience obstacles in their strive for mental health. Adolescents previously involved in Satanism present behavioral problems like aggressive outbursts, depression, “ psychosis” or suicide attempts, that could lead to suicide. In the phenomenonanalysis semi-structured, phenomenological interviews were performed with the respondents and their parents. The respondents were requested to write a naïve sketch about their life. After completion of the data-control, guidelines for nursing staff were set.

  6. Integrating Women into Previously All Male Air Force Units.

    Science.gov (United States)

    1980-05-31

    scales. Table 4 reports correlations of values for three different types of measures. Cadet conceptions of their masculinity and feminity are included as...essentially masculine traits? Tables 10 and 11 contain scores on the Bem masculinity and feminity scales for both the first and last years at the Academy...changes in cadet conceptions of masculinity and feminity at West Point are different than at the Air Force Academy. For example, both males and females

  7. Ulcerative colitis may not necessarily be rare as previously thought ...

    African Journals Online (AJOL)

    Ulcerative colitis may not necessarily be rare as previously thought in tropical and subtropical Africa. With increasing westernized life style, greater utilization and accessibility to modern medical practice,availability of tertiary level health care di.

  8. Influence of previous participation in physical activity on its ...

    African Journals Online (AJOL)

    ... participation can influence perceptions of PA among the students. Physical activity promotion programmes should consider the role of these factors which should be emphasised from childhood. Keywords: physical activity, students, perceived benefits, perceived barriers, previous participation, sedentary lifestyle, Rwanda

  9. Is Previous Respiratory Disease a Risk Factor for Lung Cancer?

    NARCIS (Netherlands)

    Denholm, Rachel; Schüz, Joachim; Straif, Kurt; Stücker, Isabelle; Jöckel, Karl-Heinz; Brenner, Darren R; De Matteis, Sara; Boffetta, Paolo; Guida, Florence; Brüske, Irene; Wichmann, Heinz-Erich; Landi, Maria Teresa; Caporaso, Neil; Siemiatycki, Jack; Ahrens, Wolfgang; Pohlabeln, Hermann; Zaridze, David; Field, John K; McLaughlin, John; Demers, Paul; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Dumitru, Rodica Stanescu; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Kendzia, Benjamin; Peters, Susan; Behrens, Thomas; Vermeulen, Roel; Brüning, Thomas; Kromhout, Hans; Olsson, Ann

    2014-01-01

    Rationale: Previous respiratory diseases have been associated with increased risk of lung cancer. Respiratory conditions often co-occur and few studies have investigated multiple conditions simultaneously. Objectives: Investigate lung cancer risk associated with chronic bronchitis, emphysema,

  10. Hypoparathyroidism after total thyroidectomy in patients with previous gastric bypass.

    Science.gov (United States)

    Droeser, Raoul A; Ottosson, Johan; Muth, Andreas; Hultin, Hella; Lindwall-Åhlander, Karin; Bergenfelz, Anders; Almquist, Martin

    2017-03-01

    Case reports suggest that patients with previous gastric bypass have an increased risk of severe hypocalcemia after total thyroidectomy, but there are no population-based studies. The prevalence of gastric bypass before thyroidectomy and the risk of hypocalcemia after thyroidectomy in patients with previous gastric bypass were investigated. By cross-linking The Scandinavian Quality Registry for Thyroid, Parathyroid and Adrenal Surgery with the Scandinavian Obesity Surgery Registry patients operated with total thyroidectomy without concurrent or previous surgery for hyperparathyroidism were identified and grouped according to previous gastric bypass. The risk of treatment with intravenous calcium during hospital stay, and with oral calcium and vitamin D at 6 weeks and 6 months postoperatively was calculated by using multiple logistic regression in the overall cohort and in a 1:1 nested case-control analysis. We identified 6115 patients treated with total thyroidectomy. Out of these, 25 (0.4 %) had undergone previous gastric bypass surgery. In logistic regression, previous gastric bypass was not associated with treatment with i.v. calcium (OR 2.05, 95 % CI 0.48-8.74), or calcium and/or vitamin D at 6 weeks (1.14 (0.39-3.35), 1.31 (0.39-4.42)) or 6 months after total thyroidectomy (1.71 (0.40-7.32), 2.28 (0.53-9.75)). In the nested case-control analysis, rates of treatment for hypocalcemia were similar in patients with and without previous gastric bypass. Previous gastric bypass surgery was infrequent in patients undergoing total thyroidectomy and was not associated with an increased risk of postoperative hypocalcemia.

  11. Source apportionment of submicron organic aerosol at an urban background and a road site in Barcelona (Spain during SAPUSS

    Directory of Open Access Journals (Sweden)

    M. Alier

    2013-10-01

    Full Text Available This study investigates the contribution of potential sources to the submicron (PM1 organic aerosol (OA simultaneously detected at an urban background (UB and a road site (RS in Barcelona during the 30 days of the intensive field campaign of SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies, September–October 2010. A total of 103 filters at 12 h sampling time resolution were collected at both sites. Thirty-six neutral and polar organic compounds of known emission sources and photo-chemical transformation processes were analyzed by gas chromatography–mass spectrometry (GC-MS. The concentrations of the trace chemical compounds analyzed are herein presented and discussed. Additionally, OA source apportionment was performed by multivariate curve resolution–alternating least squares (MCR-ALS and six OA components were identified at both sites: two were of primary anthropogenic OA origin and three of secondary OA origin, while a sixth one was not clearly defined. Primary organics from emissions of local anthropogenic activities (urban primary organic aerosol, or POA Urban, mainly traffic emissions but also cigarette smoke, contributed 43% (1.5 μg OC m−3 and 18% (0.4 μg OC m−3 to OA at RS and UB, respectively. A secondary primary source – biomass burning (BBOA – was found in all the samples (average values 7% RS; 12% UB; 0.3 μg OC m−3, but this component was substantially contributing to OA only when the sampling sites were under influence of regional air mass circulation (REG.. Three secondary organic aerosol (SOA components (describing overall 60% of the variance were observed in the urban ambient PM1. Products of isoprene oxidation (SOA ISO – i.e. 2-methylglyceric acid, C5 alkene triols and 2-methyltetrols – showed the highest abundance at both sites when the city was under influence of inland air masses. The overall concentrations of SOA ISO were similar at both sites (0.4 and 0.3 μg m−3, or 16% and 7%, at

  12. [Surgery for bronchial carcinoma after treatment of a previous cancer].

    Science.gov (United States)

    Mordant, P; Pages, P-B; Foucault, C; Badia, A; Fabre, E; Dujon, A; Le Pimpec Barthes, F; Riquet, M

    2013-05-01

    The increase in the number of cancer survivors, together with the improvement of their follow-up, lead to the frequent diagnosis of resectable non-small cell lung cancer (NSCLC) in patients with history of previous malignancy. We sought to analyse the outcomes of these patients. Patients undergoing surgical resection for NSCLC between January 1980 and December 2009 were retrospectively reviewed. For each patient, the presence of previous malignancy was noted, and classified into five groups: oro-pharyngeal cancer, lung cancer, haematopoietic malignancy, other organ malignancy, and more than two cancers. The overall population included 5846 patients. Among them, 1243 (21%) had a history of previous malignancy, of whom 383 (31%) presented with synchronous cancer. Patients with history of previous malignancy were more often female, older, with more adenocarcinomas, more limited disease, less pneumonectomies, but higher postoperative morbidity and mortality. Overall survival was worse in patients with a history of previous malignancy than in patients without (median, 5 and 10 year: 33 months, 34.3%, 17.8% versus 47 months, 44.6%, 28.8%). A history of previous malignancy impacted significantly the prognosis of patients operated on for limited NSCLC. However, only surgical resection led to improved long-term survival at 5 years. Copyright © 2013 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  13. Secondary recurrent miscarriage is associated with previous male birth.

    LENUS (Irish Health Repository)

    Ooi, Poh Veh

    2012-01-31

    Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

  14. Secondary recurrent miscarriage is associated with previous male birth.

    LENUS (Irish Health Repository)

    Ooi, Poh Veh

    2011-01-01

    Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

  15. Corneal biomechanical properties in eyes with no previous surgery, with previous penetrating keratoplasty and with deep anterior lamellar keratoplasty.

    Science.gov (United States)

    Acar, Banu Torun; Akdemir, Mehmet Orcun; Acar, Suphi

    2013-01-01

    To compare the biomechanical properties of the cornea in eyes with no previous surgery, with keratoconus with previous penetrating keratoplasty (PK) and with keratoconus with previous deep anterior lamellar keratoplasty (DALK) using the Reichert Ocular Response Analyzer (ORA). One hundred twenty eyes of 120 patients were included in this prospective comparative study. Forty eyes were with no previous ocular surgery (group 1), 40 eyes were with previous PK for keratoconus (group 2), and 40 eyes were with previous DALK for keratoconus (group 3). Corneal hysteresis (CH) and the corneal resistance factor (CRF) were measured with ORA. The CH and CRF values in group 2 were significantly lower than in group 1 and group 3 (p = 0.001). The CH and CRF values were similar in group 1 and group 3. There was no statistically significant difference between group 1 and 3. Although the post-PK keratoconus cornea has weaker biomechanical properties, post-DALK keratoconus cornea is similar to normal cornea. A cornea weakened by keratoconus can be strengthened with lamellar keratoplasty.

  16. Anisometropia magnitude and visual deficits in previously untreated anisometropic amblyopia

    Directory of Open Access Journals (Sweden)

    Bin-Bin Chen

    2013-10-01

    Full Text Available AIM:To assess the quantitative association between anisometropia magnitude and the losses of resolution and contrast sensitivity; and to exemplify how the function of fusion and stereopsis vary with anisometropia magnitude (AM in previously untreated anisometropic amblyopes.METHODS:A total of 57 patients with previously untreated anisometropic amblyopia without strabismus (range:8-35 years, were measured refractive error, best corrected visual acuity (BCVA, fusion and stereopsis, and 48 patients have completed contrast sensitivity function test. AM was determined by dioptric vector addition model, and the amblyopia depth was determined by the difference of BCVA in logMAR units between the amblyopic and fellow eyes.RESULTS: AM was significantly correlated with both amblyopia depth (Pearson R=0.728, PPPCONCLUSION: In the patients with previously untreated anisometropia amblyopia, higher degree of anisometropia is significantly associated with deeper amblyopia, worse contrast sensitivity, fusion and stereopsis functions.

  17. Intravitreal ranibizumab for diabetic macular oedema in previously vitrectomized eyes

    DEFF Research Database (Denmark)

    Laugesen, Caroline Schmidt; Ostri, Christoffer; Brynskov, Troels

    2017-01-01

    PURPOSE: There is little information about the efficacy of intravitreal vascular endothelial growth factor (VEGF) inhibition in vitrectomized eyes. This study aimed to evaluate the efficacy of anti-VEGF (ranibizumab) on diabetic macular oedema in previously vitrectomized eyes. METHODS: A nationwide...... retrospective review of medical records from 2010 to 2013. RESULTS: We identified 33 previously vitrectomized eyes in 28 patients treated with ranibizumab injections for diabetic macular oedema. Median follow-up was 323 days (interquartile range 72-1404 days). Baseline mean visual acuity was 0.57 logMAR (95% CI......). The mean reduction in CFT was 14% (95% CI 4-24%, p = 0.01). Sixteen eyes (48.5%) became devoid of oedema on the last OCT scan. Despite the significant reduction in CFT, the visual acuity remained unchanged. CONCLUSION: Intravitreal ranibizumab can be effective in previously vitrectomized eyes with diabetic...

  18. Concepts of scale and scaling

    Science.gov (United States)

    Jianguo Wu; Harbin Li

    2006-01-01

    The relationship between pattern and process is of great interest in all natural and social sciences, and scale is an integral part of this relationship. It is now well documented that biophysical and socioeconomic patterns and processes operate on a wide range of spatial and temporal scales. In particular, the scale multiplicity and scale dependence of pattern,...

  19. High-temperature dc superconducting quantum interference device with deep-submicron YBa sub 2 Cu sub 3 O sub 7 weak links

    Energy Technology Data Exchange (ETDEWEB)

    Romaine, S.E.; Mankiewich, P.M.; Skocpol, W.J. (Department of Physics, Boston University, Boston, Massachusetts (USA)); Westerwick, E. (AT T Bell Laboratories, Holmdel, New Jersey (USA))

    1991-11-11

    We have fabricated a YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) thin-film dc superconducting quantum interference device (SQUID) with lithographically defined deep-submicron weak links. At 77 K the voltage response to dc flux is sinusoidal and nonhysteretic, with maximum peak-to-peak amplitude of 5 {mu}V. The maximum response is 8 {mu}V at 70 K, where 2{ital LI}{sub 0}/{Phi}{sub 0}{approx}1. At lower temperatures, the maximum response oscillates in the range 4--6 {mu}V. Random telegraph noise was observed near 30--40 K. Well-behaved Shapiro steps were observable at all measured temperatures below {ital T}{sub {ital c}}.

  20. Superheated Water Atomization: Some New Aspects of Control and Determining Disperse Characteristics of Atomization Plume in Micron and Submicron Ranges of Droplet Size*

    Science.gov (United States)

    Zalkind, V. I.; Zeigarnik, Yu. A.; Nizovskiy, V. L.; Nizovskiy, L. V.; Schigel, S. S.

    2017-11-01

    New experimental data on superheated water atomization is presented. It is shown that in contrast to the case of short cylindrical nozzles, which provide bimodal water-droplet sprays, the application of divergent nozzles makes it possible to obtain one-modal water atomization with droplets of about micron diameter being obtained. This fact is due to changes in the mechanism of superheated water jet fragmentation and it is very important for engineering applications. A modified experimental technique for processing integral monochromatic scattering indicatrix was developed and tested. In addition, a new calculation code was worked out for calculating atomized water drop-size distribution (on the basis of Mi theory) in micron and submicron ranges.

  1. The Effect of Submicron Second-Phase Particles on the Rate of Grain Refinement in a Copper-Oxygen Alloy During Cold Spray

    Science.gov (United States)

    Zhang, Yinyin; Brodusch, Nicolas; Descartes, Sylvie; Shockley, J. Michael; Gauvin, Raynald; Chromik, Richard R.

    2017-10-01

    The effect of non-deformable submicron second-phase particles ( d = 200-500 nm) on microstructural refinement during cold spray was examined. Using single particle impact testing, two types of splats were fabricated using two different feedstocks: a Cu-0.21wt.%O powder containing Cu2O second-phase particles and a single-phase Cu. Microstructural evolution analysis using high-resolution electron backscatter diffraction shows grain refinement occurred at a higher rate in the Cu-0.21wt.%O powder. That was due to dynamic recrystallization initiated by particle-stimulated nucleation (PSN). High-strain-rate deformation of cold spray was found to be the key to activate PSN. The present study suggests cold spray is a possible technique to fabricate ultrafine-grained materials by using feedstock containing second-phase particles.

  2. Rapid fish stock depletion in previously unexploited seamounts: the ...

    African Journals Online (AJOL)

    Rapid fish stock depletion in previously unexploited seamounts: the case of Beryx splendens from the Sierra Leone Rise (Gulf of Guinea). F Salmerón, J.C. Báez, D Macías, L Fernandez-Peralta, A Ramos ...

  3. Choice of contraception after previous operative delivery at a family ...

    African Journals Online (AJOL)

    Context: Effective contraceptive use is important after a caesarean or operative delivery because of the possible risks a woman may face in subsequent pregnancies. Objectives: The objective of the present study was to determine the uptake and choices of contraception among women with previous operative delivery.

  4. 2 CFR 225.45 - Relationship to previous issuance.

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Relationship to previous issuance. 225.45 Section 225.45 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR STATE, LOCAL, AND INDIAN TRIBAL GOVERNMENTS (OMB CIRCULAR A-87) § 225.45 Relationship to...

  5. Recovery of Previously Uncultured Bacterial Genera from Three Mediterranean Sponges

    NARCIS (Netherlands)

    Versluis, Dennis; McPherson, Kyle; Passel, van Mark W.J.; Smidt, Hauke; Sipkema, Detmer

    2017-01-01

    Sponges often harbour a dense and diverse microbial community. Presently, a large discrepancy exists between the cultivable bacterial fraction from sponges and the community in its natural environment. Here, we aimed to acquire additional insights into cultivability of (previously uncultured)

  6. Snowfall in coastal West Antarctica much greater than previously assumed

    NARCIS (Netherlands)

    van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; van de Berg, W.J.|info:eu-repo/dai/nl/304831611; van Meijgaard, E.

    2006-01-01

    A new Antarctic accumulation distribution, based on regional model output calibrated with 1900 in-situ observations, is used to re-assess accumulation in 24 Antarctic ice drainage basins. When compared to the previous compilation, good agreement is found for 19 of the 24 basins, representing 93% of

  7. 5 CFR 9701.352 - Use of highest previous rate.

    Science.gov (United States)

    2010-01-01

    ... HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Pay Administration § 9701.352 Use of... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Use of highest previous rate. 9701.352 Section 9701.352 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT...

  8. Suburethral sling procedures after previous surgery for urinary ...

    African Journals Online (AJOL)

    Objective. To compare the outcome of suburethral sling procedures (tension-free vaginal tape (TVT), obturator tape (Ob-tape)) for stress urinary incontinence (SUI) in women with previous surgery for SUI or pelvic organ prolapse (POP). Methods. A comparative, descriptive, retrospective study was done using information ...

  9. The effect of previous traumatic injury on homicide risk.

    Science.gov (United States)

    Griffin, Russell L; Davis, Gregory G; Levitan, Emily B; MacLennan, Paul A; Redden, David T; McGwin, Gerald

    2014-07-01

    Research has reported that a strong risk factor for traumatic injury is having a previous injury (i.e., recidivism). To date, the only study examining the relationship between recidivism and homicide reported strong associations, but was limited by possible selection bias. The current matched case-control study utilized coroner's data from 2004 to 2008. Subjects were linked to trauma registry data to determine whether the person had a previous traumatic injury. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for the association between homicide and recidivism. Homicide risk was increased for those having a previous traumatic injury (OR 1.81, 95% CI 1.09-2.99) or a previous intentional injury (OR 2.53, 95% CI 1.24-5.17). These results suggest an association between homicide and injury recidivism, and that trauma centers may be an effective setting for screening individuals for secondary prevention efforts of homicide through violence prevention programs. © 2014 American Academy of Forensic Sciences.

  10. 24 CFR 1710.552 - Previously accepted state filings.

    Science.gov (United States)

    2010-04-01

    ... HOUSING AND URBAN DEVELOPMENT (INTERSTATE LAND SALES REGISTRATION PROGRAM) LAND REGISTRATION Certification... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Previously accepted state filings. 1710.552 Section 1710.552 Housing and Urban Development Regulations Relating to Housing and Urban...

  11. Cryptococcal meningitis in a previously healthy child | Chimowa ...

    African Journals Online (AJOL)

    An 8-year-old previously healthy female presented with a 3 weeks history of headache, neck stiffness, deafness, fever and vomiting and was diagnosed with cryptococcal meningitis. She had documented hearing loss and was referred to tertiary-level care after treatment with fluconazole did not improve her neurological ...

  12. Haemophilus influenzae type f meningitis in a previously healthy boy

    DEFF Research Database (Denmark)

    Ronit, Andreas; Berg, Ronan M G; Bruunsgaard, Helle

    2013-01-01

    Non-serotype b strains of Haemophilus influenzae are extremely rare causes of acute bacterial meningitis in immunocompetent individuals. We report a case of acute bacterial meningitis in a 14-year-old boy, who was previously healthy and had been immunised against H influenzae serotype b (Hib...

  13. The impact of previous knowledge and experience on the ...

    African Journals Online (AJOL)

    The impact of previous knowledge and experience on the entrepreneurial attitudes of Grade 12 learners. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, ...

  14. Abiraterone in metastatic prostate cancer without previous chemotherapy

    NARCIS (Netherlands)

    Ryan, C.J.; Smith, M.R.; Bono, J. De; Molina, A.; Logothetis, C.J.; Souza, P. de; Fizazi, K.; Mainwaring, P.; Piulats, J.M.; Ng, S.; Carles, J.; Mulders, P.F.A.; Basch, E.; Small, E.J.; Saad, F.; Schrijvers, D.; Poppel, H. van; Mukherjee, S.D.; Suttmann, H.; Gerritsen, W.R.; Flaig, T.W.; George, D.J.; Yu, E.Y.; Efstathiou, E.; Pantuck, A.; Winquist, E.; Higano, C.S.; Taplin, M.E.; Park, Y.; Kheoh, T.; Griffin, T.; Scher, H.I.; Rathkopf, D.E.

    2013-01-01

    BACKGROUND: Abiraterone acetate, an androgen biosynthesis inhibitor, improves overall survival in patients with metastatic castration-resistant prostate cancer after chemotherapy. We evaluated this agent in patients who had not received previous chemotherapy. METHODS: In this double-blind study, we

  15. Outcome Of Pregnancy Following A Previous Lower Segment ...

    African Journals Online (AJOL)

    Background: A previous ceasarean section is an important variable that influences patient management in subsequent pregnancies. A trial of vaginal delivery in such patients is a feasible alternative to a secondary section, thus aiding to reduce the ceasarean section rate and its associated co-morbidities. Objective: To ...

  16. A previously undescribed coronavirus associated with respiratory disease in humans.

    NARCIS (Netherlands)

    R.A.M. Fouchier (Ron); N.G. Hartwig (Nico); T.M. Bestebroer (Theo); B. Niemeyer (Berend); J.H. Simon (James); A.D.M.E. Osterhaus (Albert); J.C. de Jong (Jan)

    2004-01-01

    textabstractThe etiology of acute respiratory tract illnesses is sometimes unclear due to limitations of diagnostic tests or the existence of as-yet-unidentified pathogens. Here we describe the identification and characterization of a not previously recognized coronavirus obtained from an 8-mo-old

  17. 31 CFR 202.5 - Previously designated depositaries.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Previously designated depositaries. 202.5 Section 202.5 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE DEPOSITARIES AND FINANCIAL AGENTS...

  18. The job satisfaction of principals of previously disadvantaged schools

    African Journals Online (AJOL)

    The aim of this study was to identify influences on the job satisfaction of previously disadvantaged school principals in North-West Province. Evans's theory of job satis- faction, morale and motivation was useful as a conceptual framework. A mixed- methods explanatory research design was important in discovering issues ...

  19. The job satisfaction of principals of previously disadvantaged schools

    African Journals Online (AJOL)

    The aim of this study was to identify influences on the job satisfaction of previously disadvantaged school principals in North-West Province. Evans's theory of job satisfaction, morale and motivation was useful as a conceptual framework. A mixedmethods explanatory research design was important in discovering issues with ...

  20. Toward Quantifying the Mass-Based Hygroscopicity of Individual Submicron Atmospheric Aerosol Particles with STXM/NEXAFS and SEM/EDX

    Science.gov (United States)

    Yancey Piens, D.; Kelly, S. T.; OBrien, R. E.; Wang, B.; Petters, M. D.; Laskin, A.; Gilles, M. K.

    2014-12-01

    The hygroscopic behavior of atmospheric aerosols influences their optical and cloud-nucleation properties, and therefore affects climate. Although changes in particle size as a function of relative humidity have often been used to quantify the hygroscopic behavior of submicron aerosol particles, it has been noted that calculations of hygroscopicity based on size contain error due to particle porosity, non-ideal volume additivity and changes in surface tension. We will present a method to quantify the hygroscopic behavior of submicron aerosol particles based on changes in mass, rather than size, as a function of relative humidity. This method results from a novel experimental approach combining scanning transmission x-ray microscopy with near-edge x-ray absorption fine spectroscopy (STXM/NEXAFS), as well as scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM/EDX) on the same individual particles. First, using STXM/NEXAFS, our methods are applied to aerosol particles of known composition ‒ for instance ammonium sulfate, sodium bromide and levoglucosan ‒ and validated by theory. Then, using STXM/NEXAFS and SEM/EDX, these methods are extended to mixed atmospheric aerosol particles collected in the field at the DOE Atmospheric Radiation Measurement (ARM) Climate Research Facility at the Southern Great Planes sampling site in Oklahoma, USA. We have observed and quantified a range of hygroscopic behaviors which are correlated to the composition and morphology of individual aerosol particles. These methods will have implications for parameterizing aerosol mixing state and cloud-nucleation activity in atmospheric models.

  1. Effectiveness of sound therapy in patients with tinnitus resistant to previous treatments: importance of adjustments

    Directory of Open Access Journals (Sweden)

    Flavia Alencar de Barros Suzuki

    Full Text Available ABSTRACT INTRODUCTION: The difficulty in choosing the appropriate therapy for chronic tinnitus relates to the variable impact on the quality of life of affected patients and, thus, requires individualization of treatment. OBJECTIVE: To evaluate the effectiveness of using sound generators with individual adjustments to relieve tinnitus in patients unresponsive to previous treatments. METHODS: A prospective study of 10 patients with chronic tinnitus who were unresponsive to previous drug treatments, five males and five females, with ages ranging from 41 to 78 years. Bilateral sound generators (Reach 62 or Mind 9 models were used daily for at least 6 h during 18 months. The patients were evaluated at the beginning, after 1 month and at each 3 months until 18 months through acuphenometry, minimum masking level, the Tinnitus Handicap Inventory, visual analog scale, and the Hospital Anxiety and Depression Scale. The sound generators were adjusted at each visit. RESULTS: There was a reduction of Tinnitus Handicap Inventory in nine patients using a protocol with a customized approach, independent of psychoacoustic characteristics of tinnitus. The best response to treatment occurred in those with whistle-type tinnitus. A correlation among the adjustments and tinnitus loudness and minimum masking level was found. Only one patient, who had indication of depression by Hospital Anxiety and Depression Scale, did not respond to sound therapy. CONCLUSION: There was improvement in quality of life (Tinnitus Handicap Inventory, with good response to sound therapy using customized settings in patients who did not respond to previous treatments for tinnitus.

  2. Submicron-sized fluid inclusions and distribution of hydrous components in jadeite, quartz and symplectite-forming minerals from UHP jadeite-quartzite in the Dabie Mountains, China: TEM and FTIR investigation

    Energy Technology Data Exchange (ETDEWEB)

    Meng Dawei [Faculty of Materials Science and Chemical Engineering, China University of Geosciences, Wuhan 430074 (China); Wu Xiuling, E-mail: xlwu@cug.edu.cn [Faculty of Materials Science and Chemical Engineering, China University of Geosciences, Wuhan 430074 (China); Fan Xiaoyu [Faculty of Materials Science and Chemical Engineering, China University of Geosciences, Wuhan 430074 (China); Meng Xin [Imperial College, London SW7 2AZ (United Kingdom); Zheng Jianping; Mason, Roger [Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074 (China)

    2009-04-15

    Fluid inclusions and clusters of water molecules at nanometer-to submicron-scale in size have been investigated using transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) in jadeite, quartz and symplectite aegirine-augite, albite, taramite and magnetite corona minerals from ultrahigh-pressure (UHP) jadeite-quartzite at Shuanghe, the Dabie Mountains, China. Fluid inclusions from 0.003 {mu}m to 0.78 {mu}m in size occur in jadeite and quartz crystals, and a small number of fluid inclusions from 0.001 {mu}m to 0.25 {mu}m have also been detected in symplectite-forming minerals. Most of the fluid inclusions have round or negative crystal morphology and contain aqueous fluids, but some contain CO{sub 2}-rich fluids. They are usually connected to dislocations undetectable at an optical scale. The dislocations represent favorable paths for fluid leakage, accounting for non-decrepitation of most fluid inclusions when external pressure decreased at later stages, although there was partial decrepitation of some fluid inclusions unconnected to defect microstructures resulting from internal overpressure. Non-decrepitation and partial decrepitation of fluid inclusions resulted in changes of original composition and/or density. It is clear that identification of hidden re-equilibration features has significant implications for the petrological interpretation of post-peak metamorphic processes. Micro-FTIR results show that all jadeite and quartz samples contain structural water occurring as hydroxyl ions (OH{sup -}) and free water (H{sub 2}O) in the form of clusters of water molecules. The H{sub 2}O transformed from OH{sup -} during exhumation and could have triggered and enhanced early retrograde metamorphism of the host rocks and facilitated plastic deformation of jadeite and quartz grains by dislocation movement, and thus the H{sub 2}O released during decompression might represent early-stage retrograde metamorphic fluid. The nominally

  3. A theoretical explanation for previously infertile mothers' vulnerability to depression.

    Science.gov (United States)

    Olshansky, Ellen

    2003-01-01

    To present a theoretical approach to understanding the potential vulnerability to depression in previously infertile new mothers. This approach was developed by synthesizing results of a series of grounded theory studies of experiences of infertility and pregnancy and of parenting after infertility. These results were further synthesized with the relational cultural theory (RCT). Previously infertile new mothers have experienced repeated and sustained interferences with significant relationships over the course of their infertility, which could lead to depression. Implications of this theoretical perspective include: (a) it is a new approach to understanding a significant and sometimes minimized issue in women's health; (b) it is a basis for designing an intervention for women coping with infertility and its aftermath; and (c) it might be applied to other women's health issues.

  4. Robotic Assisted Laparoscopic Prostatectomy Performed after Previous Suprapubic Prostatectomy.

    Science.gov (United States)

    Tsui, Johnson F; Feuerstein, Michael; Jazayeri, Seyed Behzad; Samadi, David B

    2016-01-01

    Operative management of prostate cancer in a patient who has undergone previous open suprapubic simple prostatectomy poses a unique surgical challenge. Herein, we describe a case of intermediate risk prostate cancer in a man who had undergone simple prostatectomy ten years prior to presentation. The patient was found to have Gleason 7 prostate cancer on MRI fusion biopsy of the prostate for elevated PSA and underwent an uncomplicated robot assisted laparoscopic radical prostatectomy.

  5. Robotic Assisted Laparoscopic Prostatectomy Performed after Previous Suprapubic Prostatectomy

    Directory of Open Access Journals (Sweden)

    Johnson F. Tsui

    2016-01-01

    Full Text Available Operative management of prostate cancer in a patient who has undergone previous open suprapubic simple prostatectomy poses a unique surgical challenge. Herein, we describe a case of intermediate risk prostate cancer in a man who had undergone simple prostatectomy ten years prior to presentation. The patient was found to have Gleason 7 prostate cancer on MRI fusion biopsy of the prostate for elevated PSA and underwent an uncomplicated robot assisted laparoscopic radical prostatectomy.

  6. Antenatal diagnosis of Patau syndrome with previous anomalous baby

    OpenAIRE

    Keerthi Kocherla; Vasantha Kocherla

    2014-01-01

    Patau syndrome is the least common and most severe of the viable autosomal trisomies with median survival of fewer than 3 days was first identified as a cytogenetic syndrome in 1960. Patau syndrome is caused by an extra copy of chromosome 13. In this case report, we present antenatal imaging findings and gross foetal specimen correlation of foetus with Patau syndrome confirmed by karyotyping in third gravida who had significant previous obstetric history of gastrochisis in monochorionic and...

  7. A previously unidentified host protein protects retroviral DNA from autointegration

    OpenAIRE

    Lee, Myung Soo; Craigie, Robert

    1998-01-01

    Integration of a DNA copy of the viral genome into a host chromosome is an essential step in the retrovirus life cycle. The machinery that carries out the integration reaction is a nucleoprotein complex derived from the core of the infecting virion. To successfully integrate into host DNA, the viral DNA within this complex must avoid self-destructive integration into itself, a reaction termed autointegration. We have previously shown [Lee, M. S. and Craigie, R. (1994) Proc. Natl. Acad. Sci. U...

  8. Previous Violent Events and Mental Health Outcomes in Guatemala

    Science.gov (United States)

    Puac-Polanco, Victor D.; Lopez-Soto, Victor A.; Kohn, Robert; Xie, Dawei; Richmond, Therese S.

    2015-01-01

    Objectives. We analyzed a probability sample of Guatemalans to determine if a relationship exists between previous violent events and development of mental health outcomes in various sociodemographic groups, as well as during and after the Guatemalan Civil War. Methods. We used regression modeling, an interaction test, and complex survey design adjustments to estimate prevalences and test potential relationships between previous violent events and mental health. Results. Many (20.6%) participants experienced at least 1 previous serious violent event. Witnessing someone severely injured or killed was the most common event. Depression was experienced by 4.2% of participants, with 6.5% experiencing anxiety, 6.4% an alcohol-related disorder, and 1.9% posttraumatic stress disorder (PTSD). Persons who experienced violence during the war had 4.3 times the adjusted odds of alcohol-related disorders (P < .05) and 4.0 times the adjusted odds of PTSD (P < .05) compared with the postwar period. Women, indigenous Maya, and urban dwellers had greater odds of experiencing postviolence mental health outcomes. Conclusions. Violence that began during the civil war and continues today has had a significant effect on the mental health of Guatemalans. However, mental health outcomes resulting from violent events decreased in the postwar period, suggesting a nation in recovery. PMID:25713973

  9. Evaluation of cleansing methods for previously worn prostheses.

    Science.gov (United States)

    Glass, R Thomas; Conrad, Robert S; Bullard, James W; Goodson, Leigh B; Mehta, Naresh; Lech, Stanley J; Loewy, Zvi G

    2011-04-01

    Although there are many product claims that address the issue of denture sanitization, controlled scientific studies on previously worn dentures have not been performed. The purpose of this study was to evaluate procedures directed at sanitizing previously worn contaminated dentures from two regions of the United States. This study examined 51 previously worn dentures from two regions. An established method of denture retrieval, sectioning, and culturing was used, including isolation of anaerobes. Evaluation of microbial contamination posttreatment was used to determine the effects of soaking dentures in Polident (US and European formulations) for varying periods of times/temperatures, microwaving dentures with varying temperatures, sonicating dentures, and immersing the dentures while using a vacuum. A combination of analysis of variance (ANOVA) and general linear model (GLM) of the SPSS was used to analyze the data with P sanitization rather than sterilization. Denture-borne microorganisms can be significantly reduced by using a Polident solution for 8 hours at room temperature or for 5 minutes at 65 degrees C. Microwaving, sonication, and use of a vacuum were less effective. ClLINICAL IMPLICATIONS The importance of daily use of Polident solution for 8 hours or for 5 minutes at 65 degrees C to sanitize worn prostheses must be stressed.

  10. Subsequent pregnancy outcomes in women previously diagnosed with subclinical hypothyroidism.

    Science.gov (United States)

    Nelson, David B; Casey, Brian M; McIntire, Donald D; Cunningham, F Gary

    2014-01-01

    To evaluate subsequent pregnancy outcomes in women previously identified during an index pregnancy to have subclinical hypothyroidism (SCH). From 2000 to 2003, thyroid analytes were measured in 17,298 women. Using their index pregnancy thyroid-analyte classification, pregnancy outcomes were compared between the returning cohorts. There were 6,985 women previously screened and subsequently delivered at our hospital though 2011 with 230 (3.3%) designated to have SCH and 6,645 (95.1%) euthyroid. Significant differences between the two cohorts included risk for diabetes (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.2 to 2.7, p = 0.005), gestational diabetes (OR 1.74, 95% CI 1.13 to 2.69, p = 0.015), and stillbirth (OR 3.5, 95% CI 1.05 to 11.68, p = 0.042). After adjustment, the increased likelihood of diabetes (adjusted OR 1.58, 95% CI 1.04 to 2.40, p = 0.032) and stillbirth (adjusted OR 3.41, 95% CI 1.01 to 11.49, p = 0.048) persisted. Women identified during a previous pregnancy with SCH are at increased risk for some adverse perinatal outcomes during a subsequent pregnancy. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  11. The theory of n-scales

    Science.gov (United States)

    Dündar, Furkan Semih

    2018-01-01

    We provide a theory of n-scales previously called as n dimensional time scales. In previous approaches to the theory of time scales, multi-dimensional scales were taken as product space of two time scales [1, 2]. n-scales make the mathematical structure more flexible and appropriate to real world applications in physics and related fields. Here we define an n-scale as an arbitrary closed subset of ℝn. Modified forward and backward jump operators, Δ-derivatives and Δ-integrals on n-scales are defined.

  12. Women with previous stress fractures show reduced bone material strength.

    Science.gov (United States)

    Duarte Sosa, Daysi; Fink Eriksen, Erik

    2016-12-01

    Background and purpose - Bone fragility is determined by bone mass, bone architecture, and the material properties of bone. Microindentation has been introduced as a measurement method that reflects bone material properties. The pathogenesis of underlying stress fractures, in particular the role of impaired bone material properties, is still poorly understood. Based on the hypothesis that impaired bone material strength might play a role in the development of stress fractures, we used microindentation in patients with stress fractures and in controls. Patients and methods - We measured bone material strength index (BMSi) by microindentation in 30 women with previous stress fractures and in 30 normal controls. Bone mineral density by DXA and levels of the bone markers C-terminal cross-linking telopeptide of type-1 collagen (CTX) and N-terminal propeptide of type-1 procollagen (P1NP) were also determined. Results - Mean BMSi in stress fracture patients was significantly lower than in the controls (SD 72 (8.7) vs. 77 (7.2); p = 0.02). The fracture subjects also had a significantly lower mean bone mineral density (BMD) than the controls (0.9 (0.02) vs. 1.0 (0.06); p = 0.03). Bone turnover-as reflected in serum levels of the bone marker CTX-was similar in both groups, while P1NP levels were significantly higher in the women with stress fractures (55 μg/L vs. 42 μg/L; p = 0.03). There was no correlation between BMSi and BMD or bone turnover. Interpretation - BMSi was inferior in patients with previous stress fracture, but was unrelated to BMD and bone turnover. The lower values of BMSi in patients with previous stress fracture combined with a lower BMD may contribute to the increased propensity to develop stress fractures in these patients.

  13. Sofosbuvir, Velpatasvir, and Voxilaprevir for Previously Treated HCV Infection.

    Science.gov (United States)

    Bourlière, Marc; Gordon, Stuart C; Flamm, Steven L; Cooper, Curtis L; Ramji, Alnoor; Tong, Myron; Ravendhran, Natarajan; Vierling, John M; Tran, Tram T; Pianko, Stephen; Bansal, Meena B; de Lédinghen, Victor; Hyland, Robert H; Stamm, Luisa M; Dvory-Sobol, Hadas; Svarovskaia, Evguenia; Zhang, Jie; Huang, K C; Subramanian, G Mani; Brainard, Diana M; McHutchison, John G; Verna, Elizabeth C; Buggisch, Peter; Landis, Charles S; Younes, Ziad H; Curry, Michael P; Strasser, Simone I; Schiff, Eugene R; Reddy, K Rajender; Manns, Michael P; Kowdley, Kris V; Zeuzem, Stefan

    2017-06-01

    Patients who are chronically infected with hepatitis C virus (HCV) and who do not have a sustained virologic response after treatment with regimens containing direct-acting antiviral agents (DAAs) have limited retreatment options. We conducted two phase 3 trials involving patients who had been previously treated with a DAA-containing regimen. In POLARIS-1, patients with HCV genotype 1 infection who had previously received a regimen containing an NS5A inhibitor were randomly assigned in a 1:1 ratio to receive either the nucleotide polymerase inhibitor sofosbuvir, the NS5A inhibitor velpatasvir, and the protease inhibitor voxilaprevir (150 patients) or matching placebo (150 patients) once daily for 12 weeks. Patients who were infected with HCV of other genotypes (114 patients) were enrolled in the sofosbuvir-velpatasvir-voxilaprevir group. In POLARIS-4, patients with HCV genotype 1, 2, or 3 infection who had previously received a DAA regimen but not an NS5A inhibitor were randomly assigned in a 1:1 ratio to receive sofosbuvir-velpatasvir-voxilaprevir (163 patients) or sofosbuvir-velpatasvir (151 patients) for 12 weeks. An additional 19 patients with HCV genotype 4 infection were enrolled in the sofosbuvir-velpatasvir-voxilaprevir group. In the three active-treatment groups, 46% of the patients had compensated cirrhosis. In POLARIS-1, the rate of sustained virologic response was 96% with sofosbuvir-velpatasvir-voxilaprevir, as compared with 0% with placebo. In POLARIS-4, the rate of response was 98% with sofosbuvir-velpatasvir-voxilaprevir and 90% with sofosbuvir-velpatasvir. The most common adverse events were headache, fatigue, diarrhea, and nausea. In the active-treatment groups in both trials, the percentage of patients who discontinued treatment owing to adverse events was 1% or lower. Sofosbuvir-velpatasvir-voxilaprevir taken for 12 weeks provided high rates of sustained virologic response among patients across HCV genotypes in whom treatment with a DAA regimen

  14. Cutaneous protothecosis in a patient with previously undiagnosed HIV infection.

    Science.gov (United States)

    Fong, Kenneth; Tee, Shang-Ian; Ho, Madeline S L; Pan, Jiun Yit

    2015-08-01

    Protothecosis is an uncommon condition resulting from infection by achlorophyllous algae of the Prototheca species. Immunocompromised individuals are generally most susceptible to protothecal infection and tend to develop severe and disseminated disease. However, the association between protothecosis and HIV-induced immunosuppression is not clear, with only a handful of cases having been described to date. Here we report a case of cutaneous protothecosis in a Chinese man with previously undiagnosed HIV infection that responded well to oral itraconazole. © 2014 The Australasian College of Dermatologists.

  15. Atrial fibrillation after taser exposure in a previously healthy adolescent.

    Science.gov (United States)

    Multerer, Sara; Berkenbosch, John W; Das, Bibhuti; Johnsrude, Christopher

    2009-12-01

    We are reporting a previously healthy adolescent who developed atrial fibrillation after being tased. He has a structurally normal heart on echocardiogram, normal electrolyte level and thyroid function test results, and a urine toxicology screen positive for marijuana. The patient ultimately required external defibrillation to convert his cardiac rhythm to normal sinus rhythm and has had no recurrent arrhythmias since hospital discharge (approximately 1 year). This is the first reported case of atrial fibrillation developing after a Taser shot, occurring in an adolescent without other risk factors. This case illustrates the arrhythmogenic potential of a Taser in otherwise healthy young individuals, and further study of occurrence of Taser-induced arrhythmias is warranted.

  16. HEART TRANSPLANTATION IN PATIENTS WITH PREVIOUS OPEN HEART SURGERY

    Directory of Open Access Journals (Sweden)

    R. Sh. Saitgareev

    2016-01-01

    Full Text Available Heart Transplantation (HTx to date remains the most effective and radical method of treatment of patients with end-stage heart failure. The defi cit of donor hearts is forcing to resort increasingly to the use of different longterm mechanical circulatory support systems, including as a «bridge» to the follow-up HTx. According to the ISHLT Registry the number of recipients underwent cardiopulmonary bypass surgery increased from 40% in the period from 2004 to 2008 to 49.6% for the period from 2009 to 2015. HTx performed in repeated patients, on the one hand, involves considerable technical diffi culties and high risks; on the other hand, there is often no alternative medical intervention to HTx, and if not dictated by absolute contradictions the denial of the surgery is equivalent to 100% mortality. This review summarizes the results of a number of published studies aimed at understanding the immediate and late results of HTx in patients, previously underwent open heart surgery. The effect of resternotomy during HTx and that of the specifi c features associated with its implementation in recipients previously operated on open heart, and its effects on the immediate and long-term survival were considered in this review. Results of studies analyzing the risk factors for perioperative complications in repeated recipients were also demonstrated. Separately, HTx risks after implantation of prolonged mechanical circulatory support systems were examined. The literature does not allow to clearly defi ning the impact factor of earlier performed open heart surgery on the course of perioperative period and on the prognosis of survival in recipients who underwent HTx. On the other hand, subject to the regular fl ow of HTx and the perioperative period the risks in this clinical situation are justifi ed as a long-term prognosis of recipients previously conducted open heart surgery and are comparable to those of patients who underwent primary HTx. Studies

  17. Moyamoya disease in a child with previous acute necrotizing encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taik-Kun; Cha, Sang Hoon; Chung, Kyoo Byung; Kim, Jung Hyuck; Kim, Baek Hyun; Chung, Hwan Hoon [Department of Diagnostic Radiology, Korea University College of Medicine, Ansan Hospital, 516 Kojan-Dong, Ansan City, Kyungki-Do 425-020 (Korea); Eun, Baik-Lin [Department of Pediatrics, Korea University College of Medicine, Seoul (Korea)

    2003-09-01

    A previously healthy 24-day-old boy presented with a 2-day history of fever and had a convulsion on the day of admission. MRI showed abnormal signal in the thalami, caudate nuclei and central white matter. Acute necrotising encephalopathy was diagnosed, other causes having been excluded after biochemical and haematological analysis of blood, urine and CSF. He recovered, but with spastic quadriparesis. At the age of 28 months, he suffered sudden deterioration of consciousness and motor weakness of his right limbs. MRI was consistent with an acute cerebrovascular accident. Angiography showed bilateral middle cerebral artery stenosis or frank occlusion with numerous lenticulostriate collateral vessels consistent with moyamoya disease. (orig.)

  18. Fulminant Pneumococcal Pericarditis in a Previously Healthy Patient.

    Science.gov (United States)

    Trpkov, Cvetan; Nath, Ermin; Moon, Michael; Windram, Jonathan; Graham, Michelle M

    2017-04-01

    Purulent pericarditis is a rare acutely life-threatening condition. Initial symptoms, signs, and investigations can be nonspecific. Echocardiography is invaluable for establishing the diagnosis and initial management. We present a case of a previously healthy patient with purulent pericarditis caused by Streptococcus pneumoniae in the absence of a primary focus of infection. The patient deteriorated rapidly with cardiac tamponade and septic shock and was managed successfully by a combined medical and surgical approach. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  19. Global Distribution of Extreme Precipitation and High-Impact Landslides in 2010 Relative to Previous Years

    Science.gov (United States)

    Kirschbaum, Dalia; Adler, Robert; Adler, David; Peters-Lidard, Christa; Huffman, George

    2012-01-01

    It is well known that extreme or prolonged rainfall is the dominant trigger of landslides worldwide. While research has evaluated the spatiotemporal distribution of extreme rainfall and landslides at local or regional scales using in situ data, few studies have mapped rainfall-triggered landslide distribution globally due to the dearth of landslide data and consistent precipitation information. This study uses a newly developed Global Landslide Catalog (GLC) and a 13-year satellite-based precipitation record from TRMM data. For the first time, these two unique products provide the foundation to quantitatively evaluate the co-occurrence of precipitation and landslides globally. Evaluation of the GLC indicates that 2010 had a large number of high-impact landslide events relative to previous years. This study considers how variations in extreme and prolonged satellite-based rainfall are related to the distribution of landslides over the same time scales for three active landslide areas: Central America, the Himalayan Arc, and central-eastern China. Several test statistics confirm that TRMM rainfall generally scales with the observed increase in landslide reports and fatal events for 2010 and previous years over each region. These findings suggest that the co-occurrence of satellite precipitation and landslide reports may serve as a valuable indicator for characterizing the spatiotemporal distribution of landslide-prone areas in order to establish a global rainfall-triggered landslide climatology. This study characterizes the variability of satellite precipitation data and reported landslide activity at the globally scale in order to improve landslide cataloging, forecasting and quantify potential triggering sources at daily, monthly and yearly time scales.

  20. Melanoma diagnosed in lesions previously treated by laser therapy.

    Science.gov (United States)

    Delker, Sarah; Livingstone, Elisabeth; Schimming, Tobias; Schadendorf, Dirk; Griewank, Klaus G

    2017-01-01

    Laser therapy has become a routine procedure in dermatological practice and is frequently also used for pigmented lesions. Few reports exist of melanomas diagnosed in lesions previously treated by laser therapy. Between 2007 and 2014, we identified 11 patients who presented to our department with a melanoma diagnosed in a region previously treated by laser therapy. The course of events until the diagnosis of melanoma was assessed as well as patient outcome including treatment for disease progression. No histological assessment had been performed prior to laser therapy in nine of 11 (82%) cases. Benign melanocytic lesions had been diagnosed by biopsy prior to laser therapy in the other two cases. Time from laser therapy to diagnosis of melanoma ranged from less than 1 to 10 years. Stage of disease at diagnosis varied from stage IA to IIIC. Four patients progressed to stage IV disease, of whom at least one died of melanoma. We conclude that laser treatment of pigmented lesions can complicate the diagnosis of melanoma and lead to diagnosis delay with potentially fatal consequences. Considering this risk, we believe laser therapy for pigmented lesions should either be avoided entirely or at a minimum performed only after prior histological assessment. © 2016 Japanese Dermatological Association.

  1. Does previous healthcare experience increase success in physician assistant training?

    Science.gov (United States)

    Hegmann, Theresa; Iverson, Katie

    2016-06-01

    Healthcare experience is used by many physician assistant (PA) programs to rank applicants. Despite a large healthcare literature base evaluating admissions factors, little information is available on the relationship of healthcare experience and educational outcomes. We aimed to test whether previous healthcare experience is associated with increased success during the clinical portion of the PA educational process. Hours of direct healthcare experience reported on Central Application Service for Physician Assistants applications for 124 students in the classes of 2009 through 2013 were associated with a calculated average preceptor evaluation score for each student and with average standardized-patient examination scores for a subset of students. Average student age was 28.7 years and median healthcare experience was 2,257 hours (range 390-16,400). Previous healthcare experience was not significantly correlated with preceptor evaluations or standardized-patient examination scores. This 5-year single institution pilot study did not support the hypothesis that healthcare experience is associated with improved clinical year outcomes.

  2. Kidnapping Detection and Recognition in Previous Unknown Environment

    Directory of Open Access Journals (Sweden)

    Yang Tian

    2017-01-01

    Full Text Available An unaware event referred to as kidnapping makes the estimation result of localization incorrect. In a previous unknown environment, incorrect localization result causes incorrect mapping result in Simultaneous Localization and Mapping (SLAM by kidnapping. In this situation, the explored area and unexplored area are divided to make the kidnapping recovery difficult. To provide sufficient information on kidnapping, a framework to judge whether kidnapping has occurred and to identify the type of kidnapping with filter-based SLAM is proposed. The framework is called double kidnapping detection and recognition (DKDR by performing two checks before and after the “update” process with different metrics in real time. To explain one of the principles of DKDR, we describe a property of filter-based SLAM that corrects the mapping result of the environment using the current observations after the “update” process. Two classical filter-based SLAM algorithms, Extend Kalman Filter (EKF SLAM and Particle Filter (PF SLAM, are modified to show that DKDR can be simply and widely applied in existing filter-based SLAM algorithms. Furthermore, a technique to determine the adapted thresholds of metrics in real time without previous data is presented. Both simulated and experimental results demonstrate the validity and accuracy of the proposed method.

  3. Suicidal imagery in a previously depressed community sample.

    Science.gov (United States)

    Crane, Catherine; Shah, Dhruvi; Barnhofer, Thorsten; Holmes, Emily A

    2012-01-01

    This study sought to replicate previous findings of vivid suicide-related imagery in previously suicidal patients in a community sample of adults with a history of depression. Twenty-seven participants were interviewed regarding suicidal imagery. Seventeen participants reported prior suicidal ideation or behaviour in the clinical assessment, and the vast majority of these also reported experiencing suicide-related imagery when at their most depressed and despairing, in many cases in the form of flash-forwards to imagined future suicidal acts. Interestingly, five of the 10 participants who did not report suicidal ideation or behaviour in the clinical interview also described prominent imagery related to themes of death and suicide, but in several cases, these images were associated with meanings that seemed to act to reduce the likelihood of subsequent suicidal acts. Severity of prior suicidality was associated with lower levels of imagery-related distress and higher levels of imagery-related comfort. These findings support the idea that suicide-related imagery is an important component in the phenomenology of depression and despair and hint at potentially important differences in the meaning associated with such imagery between those individuals who report experiencing suicidal ideation or behaviour when depressed and those who do not. The findings are consistent with Joiner's model of acquired capability for suicide through habituation to pain and fear of suicide and suggest that it may be useful to tackle such imagery directly in the treatment of suicidal patients. Copyright © 2011 John Wiley & Sons, Ltd.

  4. Are previous suicide attempts a risk factor for completed suicide?

    Science.gov (United States)

    Goñi-Sarriés, Adriana; Blanco, Miriam; Azcárate, Leire; Peinado, Rubén; López-Goñi, José J

    2018-02-01

    A previous suicide attempt is a clinically relevant factor for completed suicide. In this paper people who committed suicide on their first attempt are compared with those who did so after previous attempts. A review of the Computerised Clinical Histories in the Navarro Health Service-Osasunbidea (2010-2013) in Spain. Of the 166 cases, 31.9% (n = 53) presented at least one prior attempt. Of these 53, 65.3% modified the method of suicide. Women presented significantly more attempts (χ2 = 14.3; df = 3; p = .002). Three sub-samples were identified according to the attempts and diagnoses. The diagnoses of personality disorders (90.9%; n = 10) and women under 51 years of age with a diagnosis of affective, anxiety, or substance abuse disorders (82.4%; n = 14) presented the highest numbers of attempts. People without a psychiatric diagnosis and with psychotic or organic mental disorders presented the smallest proportion of attempts (13.2%; n = 10) together with people over 51 years of age diagnosed with affective, anxiety, or substance abuse disorders (22.5%; n = 9). Prior attempts are suicide risk factors only in specific clinical sub-samples. Prevention and intervention programs should consider these results.

  5. Incidence of Acneform Lesions in Previously Chemically Damaged Persons-2004

    Directory of Open Access Journals (Sweden)

    N Dabiri

    2008-04-01

    Full Text Available ABSTRACT: Introduction & Objective: Chemical gas weapons especially nitrogen mustard which was used in Iraq-Iran war against Iranian troops have several harmful effects on skin. Some other chemical agents also can cause acne form lesions on skin. The purpose of this study was to compare the incidence of acneform in previously chemically damaged soldiers and non chemically damaged persons. Materials & Methods: In this descriptive and analytical study, 180 chemically damaged soldiers, who have been referred to dermatology clinic between 2000 – 2004, and forty non-chemically damaged people, were chosen randomly and examined for acneform lesions. SPSS software was used for statistic analysis of the data. Results: The mean age of the experimental group was 37.5 ± 5.2 and that of the control group was 38.7 ± 5.9 years. The mean percentage of chemical damage in cases was 31 percent and the time after the chemical damage was 15.2 ± 1.1 years. Ninety seven cases (53.9 percent of the subjects and 19 people (47.5 percent of the control group had some degree of acne. No significant correlation was found in incidence, degree of lesions, site of lesions and age of subjects between two groups. No significant correlation was noted between percentage of chemical damage and incidence and degree of lesions in case group. Conclusion: Incidence of acneform lesions among previously chemically injured peoples was not higher than the normal cases.

  6. Do emotional intelligence and previous caring experience influence student nurse performance? A comparative analysis.

    Science.gov (United States)

    Stenhouse, Rosie; Snowden, Austyn; Young, Jenny; Carver, Fiona; Carver, Hannah; Brown, Norrie

    2016-08-01

    Reports of poor nursing care have focused attention on values based selection of candidates onto nursing programmes. Values based selection lacks clarity and valid measures. Previous caring experience might lead to better care. Emotional intelligence (EI) might be associated with performance, is conceptualised and measurable. To examine the impact of 1) previous caring experience, 2) emotional intelligence 3) social connection scores on performance and retention in a cohort of first year nursing and midwifery students in Scotland. A longitudinal, quasi experimental design. Adult and mental health nursing, and midwifery programmes in a Scottish University. Adult, mental health and midwifery students (n=598) completed the Trait Emotional Intelligence Questionnaire-short form and Schutte's Emotional Intelligence Scale on entry to their programmes at a Scottish University, alongside demographic and previous caring experience data. Social connection was calculated from a subset of questions identified within the TEIQue-SF in a prior factor and Rasch analysis. Student performance was calculated as the mean mark across the year. Withdrawal data were gathered. 598 students completed baseline measures. 315 students declared previous caring experience, 277 not. An independent-samples t-test identified that those without previous caring experience scored higher on performance (57.33±11.38) than those with previous caring experience (54.87±11.19), a statistically significant difference of 2.47 (95% CI, 0.54 to 4.38), t(533)=2.52, p=.012. Emotional intelligence scores were not associated with performance. Social connection scores for those withdrawing (mean rank=249) and those remaining (mean rank=304.75) were statistically significantly different, U=15,300, z=-2.61, p$_amp_$lt;0.009. Previous caring experience led to worse performance in this cohort. Emotional intelligence was not a useful indicator of performance. Lower scores on the social connection factor were associated

  7. Nivolumab in previously untreated melanoma without BRAF mutation.

    Science.gov (United States)

    Robert, Caroline; Long, Georgina V; Brady, Benjamin; Dutriaux, Caroline; Maio, Michele; Mortier, Laurent; Hassel, Jessica C; Rutkowski, Piotr; McNeil, Catriona; Kalinka-Warzocha, Ewa; Savage, Kerry J; Hernberg, Micaela M; Lebbé, Celeste; Charles, Julie; Mihalcioiu, Catalin; Chiarion-Sileni, Vanna; Mauch, Cornelia; Cognetti, Francesco; Arance, Ana; Schmidt, Henrik; Schadendorf, Dirk; Gogas, Helen; Lundgren-Eriksson, Lotta; Horak, Christine; Sharkey, Brian; Waxman, Ian M; Atkinson, Victoria; Ascierto, Paolo A

    2015-01-22

    Nivolumab was associated with higher rates of objective response than chemotherapy in a phase 3 study involving patients with ipilimumab-refractory metastatic melanoma. The use of nivolumab in previously untreated patients with advanced melanoma has not been tested in a phase 3 controlled study. We randomly assigned 418 previously untreated patients who had metastatic melanoma without a BRAF mutation to receive nivolumab (at a dose of 3 mg per kilogram of body weight every 2 weeks and dacarbazine-matched placebo every 3 weeks) or dacarbazine (at a dose of 1000 mg per square meter of body-surface area every 3 weeks and nivolumab-matched placebo every 2 weeks). The primary end point was overall survival. At 1 year, the overall rate of survival was 72.9% (95% confidence interval [CI], 65.5 to 78.9) in the nivolumab group, as compared with 42.1% (95% CI, 33.0 to 50.9) in the dacarbazine group (hazard ratio for death, 0.42; 99.79% CI, 0.25 to 0.73; Psurvival was 5.1 months in the nivolumab group versus 2.2 months in the dacarbazine group (hazard ratio for death or progression of disease, 0.43; 95% CI, 0.34 to 0.56; Psurvival benefit with nivolumab versus dacarbazine was observed across prespecified subgroups, including subgroups defined by status regarding the programmed death ligand 1 (PD-L1). Common adverse events associated with nivolumab included fatigue, pruritus, and nausea. Drug-related adverse events of grade 3 or 4 occurred in 11.7% of the patients treated with nivolumab and 17.6% of those treated with dacarbazine. Nivolumab was associated with significant improvements in overall survival and progression-free survival, as compared with dacarbazine, among previously untreated patients who had metastatic melanoma without a BRAF mutation. (Funded by Bristol-Myers Squibb; CheckMate 066 ClinicalTrials.gov number, NCT01721772.).

  8. Sub-micron indent induced plastic deformation in copper and irradiated steel; Deformation plastique induite par l'essai d'indentation submicronique, dans le cuivre et l'acier 316L irradie

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Ch

    1999-07-01

    In this work we aim to study the indent induced plastic deformation. For this purpose, we have developed a new approach, whereby the indentation curves provides the mechanical behaviour, while the deformation mechanisms are observed thanks to Transmission Electron Microscopy (TEM). In order to better understand how an indent induced dislocation microstructure forms, numerical modeling of the indentation process at the scale of discrete dislocations has been worked out as well. Validation of this modeling has been performed through direct comparison of the computed microstructures with TEM micrographs of actual indents in pure Cu (001]. Irradiation induced modifications of mechanical behaviour of ion irradiated 316L have been investigated, thanks to the mentioned approach. An important hardening effect was reported from indentation data (about 50%), on helium irradiated 316L steel. TEM observations of the damage zone clearly show that this behaviour is associated with the presence of He bubbles. TEM observations of the indent induced plastic zone also showed that the extent of the plastic zone is strongly correlated with hardness, that is to say: harder materials gets a smaller plastic zone. These results thus clearly established that the selected procedure can reveal any irradiation induced hardening in sub-micron thick ion irradiated layers. The behaviour of krypton irradiated 316L steel is somewhat more puzzling. In one hand indeed, a strong correlation between the defect cluster size and densities on the irradiation temperature is observed in the 350 deg. C - 600 deg. C range, thanks to TEM observations of the damage zone. On the other hand, irradiation induced hardening reported from indentation data is relatively small (about 10%) and shows no dependence upon the irradiation temperature (within the mentioned range). In addition, it has been shown that the reported hardening vanishes following appropriate post-irradiation annealing, although most of the TEM

  9. The long-term consequences of previous hyperthyroidism

    DEFF Research Database (Denmark)

    Hjelm Brandt Kristensen, Frans

    2015-01-01

    vascular state. While it is biologically plausible that these changes may induce long-term consequences, the insight into morbidity as well as mortality in patients with previous hyperthyroidism is limited. The reasons for this are a combination of inadequately powered studies, varying definitions......,400 non-hyperthyroid control individuals (matched for age and sex), all identified from a random 5% sample of the Danish background population (n=339,481). In the second study population, 625 same-sex twin pairs, discordant for hyperthyroidism, were included. For each individual, the degree of co......-up (>10 years) as well as control for co-morbidity and genetic confounding. The results provide a number of interesting insights into the long-term consequences of hyperthyroidism. Firstly, hyperthyroidism is associated with an approximately 30% increased all-cause mortality. The all-cause mortality does...

  10. Malignant tumor formation in dogs previously irradiated for acanthomatous epulis.

    Science.gov (United States)

    McEntee, Margaret C; Page, Rodney L; Théon, Alain; Erb, Hollis N; Thrall, Donald E

    2004-01-01

    In this retrospective study of 57 dogs irradiated for oral acanthomatous epulis, 2 (3.5%) dogs developed a second tumor (sarcoma, osteosarcoma) in the radiation treatment field at 5.2 and 8.7 years after the end of radiation therapy. As opposed to previous reports, no second epithelial tumors developed in the radiation treatment field. There is a risk of radiation-induced carcinogenesis, but it appears that it is a relatively low risk and an event that occurs years after radiation therapy. Radiation-induced tumors are of more concern in younger dogs that undergo radiation therapy for tumors that are radioresponsive, such as acanthomatous epulis, where long-term survival is expected. The only statistically significant variable in the survival analysis was age, with dogs less than 8.3 years old having a significantly longer median overall survival (2322 days) than dogs older than 8.3 years (1106 days; P<0.0001).

  11. MISSE Thermal Control Materials with Comparison to Previous Flight Experiments

    Science.gov (United States)

    Finckenor, Miria; Pippin, H. Gary; Frey, George

    2008-01-01

    Many different passive thermal control materials were flown as part of the Materials on International Space Station Experiment (MISSE), including inorganic coatings, anodized aluminum, and multi-layer insulation materials. These and other material samples were exposed to the low Earth orbital environment of atomic oxygen, ultraviolet radiation, thermal cycling, and hard vacuum, though atomic oxygen exposure was limited for some samples. Materials flown on MISSE-1 and MISSE-2 were exposed to the space environment for nearly four years. Materials flown on MISSE-3, MISSE-4, and MISSE-5 were exposed to the space environment for one year. Solar absorptance, infrared emittance, and mass measurements indicate the durability of these materials to withstand the space environment. Effects of short duration versus long duration exposure on ISS are explored, as well as comparable data from previous flight experiments, such as the Passive Optical Sample Assembly (POSA), Optical Properties Monitor (OPM), and Long Duration Exposure Facility (LDEF).

  12. Lessons from Previous Expeditions for the Human Exploration of Mars

    Science.gov (United States)

    Stuster, J.

    Anecdotal comparisons frequently are made between expeditions of the past and future space missions. From an engineering perspective, the differences between future and past expeditions are considerable. Spacecraft are far more complex than sailing ships, and one of the factors that drives the complexity is the requirement to support the crew in the hostile environment of space. The technological differences are significant, but from a behavioral perspective, are the differences really that great between confinement in a small wooden ship locked in the polar ice cap and confinement in a small high-technology ship hurtling through interplanetary space? The psychological differences probably are few. This paper discusses some of the most salient behavioral and technical lessons from previous expeditions that can be applied to facilitate the human explora- tion of Mars.

  13. Effect of previous induced abortions on postabortion contraception selection.

    Science.gov (United States)

    Keene, Melissa; Roston, Alicia; Keith, Louis; Patel, Ashlesha

    2015-05-01

    The objective was to compare contraceptive method selection in women undergoing their first pregnancy termination versus women undergoing repeat pregnancy termination in an urban abortion clinic. We hypothesized that women undergoing repeat abortions will select highly effective contraceptives (intrauterine device, subdermal implant, tubal ligation) more often than patients undergoing their first abortion. We conducted a retrospective analysis of all women undergoing first-trimester surgical abortion at John H. Stroger, Jr., Hospital of Cook County from October 1, 2009, to October 31, 2011. We compared contraceptive method selection in the postabortion period after receipt of contraceptive counseling for 7466 women, stratifying women by history of no prior abortion versus one or more abortions. Of the 7466 women, 48.6% (3625) had no history of previous abortion. After controlling for age, race and number of living children, women with a history of abortion were more likely to select a highly effective method [odds ratio (OR) 1.19, 95% confidence interval (CI) 1.06-1.33]. Most significantly, having living children was the strongest predictor of a highly effective method with an OR of 3.17 (95% CI 2.69-3.75). In women having a first-trimester abortion, the factors most predictive of selecting a highly effective method for postabortion contraception include history of previous abortion and having living children. The latter holds true independent of abortion history. This paper is unique in its ability to demonstrate the high interest in highly effective contraceptive selection in high-risk, low-income women with prior abortion history. Efforts to integrate provision of highly effective methods of contraception for postabortion care are essential for the reduction of future unintended pregnancies. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Typing DNA profiles from previously enhanced fingerprints using direct PCR.

    Science.gov (United States)

    Templeton, Jennifer E L; Taylor, Duncan; Handt, Oliva; Linacre, Adrian

    2017-07-01

    Fingermarks are a source of human identification both through the ridge patterns and DNA profiling. Typing nuclear STR DNA markers from previously enhanced fingermarks provides an alternative method of utilising the limited fingermark deposit that can be left behind during a criminal act. Dusting with fingerprint powders is a standard method used in classical fingermark enhancement and can affect DNA data. The ability to generate informative DNA profiles from powdered fingerprints using direct PCR swabs was investigated. Direct PCR was used as the opportunity to generate usable DNA profiles after performing any of the standard DNA extraction processes is minimal. Omitting the extraction step will, for many samples, be the key to success if there is limited sample DNA. DNA profiles were generated by direct PCR from 160 fingermarks after treatment with one of the following dactyloscopic fingerprint powders: white hadonite; silver aluminium; HiFi Volcano silk black; or black magnetic fingerprint powder. This was achieved by a combination of an optimised double-swabbing technique and swab media, omission of the extraction step to minimise loss of critical low-template DNA, and additional AmpliTaq Gold(®) DNA polymerase to boost the PCR. Ninety eight out of 160 samples (61%) were considered 'up-loadable' to the Australian National Criminal Investigation DNA Database (NCIDD). The method described required a minimum of working steps, equipment and reagents, and was completed within 4h. Direct PCR allows the generation of DNA profiles from enhanced prints without the need to increase PCR cycle numbers beyond manufacturer's recommendations. Particular emphasis was placed on preventing contamination by applying strict protocols and avoiding the use of previously used fingerprint brushes. Based on this extensive survey, the data provided indicate minimal effects of any of these four powders on the chance of obtaining DNA profiles from enhanced fingermarks. Copyright © 2017

  15. Is Previous Respiratory Disease a Risk Factor for Lung Cancer?

    Science.gov (United States)

    Denholm, Rachel; Schüz, Joachim; Straif, Kurt; Stücker, Isabelle; Jöckel, Karl-Heinz; Brenner, Darren R.; De Matteis, Sara; Boffetta, Paolo; Guida, Florence; Brüske, Irene; Wichmann, Heinz-Erich; Landi, Maria Teresa; Caporaso, Neil; Siemiatycki, Jack; Ahrens, Wolfgang; Pohlabeln, Hermann; Zaridze, David; Field, John K.; McLaughlin, John; Demers, Paul; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Dumitru, Rodica Stanescu; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Kendzia, Benjamin; Peters, Susan; Behrens, Thomas; Vermeulen, Roel; Brüning, Thomas; Kromhout, Hans

    2014-01-01

    Rationale: Previous respiratory diseases have been associated with increased risk of lung cancer. Respiratory conditions often co-occur and few studies have investigated multiple conditions simultaneously. Objectives: Investigate lung cancer risk associated with chronic bronchitis, emphysema, tuberculosis, pneumonia, and asthma. Methods: The SYNERGY project pooled information on previous respiratory diseases from 12,739 case subjects and 14,945 control subjects from 7 case–control studies conducted in Europe and Canada. Multivariate logistic regression models were used to investigate the relationship between individual diseases adjusting for co-occurring conditions, and patterns of respiratory disease diagnoses and lung cancer. Analyses were stratified by sex, and adjusted for age, center, ever-employed in a high-risk occupation, education, smoking status, cigarette pack-years, and time since quitting smoking. Measurements and Main Results: Chronic bronchitis and emphysema were positively associated with lung cancer, after accounting for other respiratory diseases and smoking (e.g., in men: odds ratio [OR], 1.33; 95% confidence interval [CI], 1.20–1.48 and OR, 1.50; 95% CI, 1.21–1.87, respectively). A positive relationship was observed between lung cancer and pneumonia diagnosed 2 years or less before lung cancer (OR, 3.31; 95% CI, 2.33–4.70 for men), but not longer. Co-occurrence of chronic bronchitis and emphysema and/or pneumonia had a stronger positive association with lung cancer than chronic bronchitis “only.” Asthma had an inverse association with lung cancer, the association being stronger with an asthma diagnosis 5 years or more before lung cancer compared with shorter. Conclusions: Findings from this large international case–control consortium indicate that after accounting for co-occurring respiratory diseases, chronic bronchitis and emphysema continue to have a positive association with lung cancer. PMID:25054566

  16. Surgical treatment of breast cancer in previously augmented patients.

    Science.gov (United States)

    Karanas, Yvonne L; Leong, Darren S; Da Lio, Andrew; Waldron, Kathleen; Watson, James P; Chang, Helena; Shaw, William W

    2003-03-01

    The incidence of breast cancer is increasing each year. Concomitantly, cosmetic breast augmentation has become the second most often performed cosmetic surgical procedure. As the augmented patient population ages, an increasing number of breast cancer cases among previously augmented women can be anticipated. The surgical treatment of these patients is controversial, with several questions remaining unanswered. Is breast conservation therapy feasible in this patient population and can these patients retain their implants? A retrospective review of all breast cancer patients with a history of previous augmentation mammaplasty who were treated at the Revlon/UCLA Breast Center between 1991 and 2001 was performed. During the study period, 58 patients were treated. Thirty patients (52 percent) were treated with a modified radical mastectomy with implant removal. Twenty-eight patients (48 percent) underwent breast conservation therapy, which consisted of lumpectomy, axillary lymph node dissection, and radiotherapy. Twenty-two of the patients who underwent breast conservation therapy initially retained their implants. Eleven of those 22 patients (50 percent) ultimately required completion mastectomies with implant removal because of implant complications (two patients), local recurrences (five patients), or the inability to obtain negative margins (four patients). Nine additional patients experienced complications resulting from their implants, including contracture, erosion, pain, and rupture. The data illustrate that breast conservation therapy with maintenance of the implant is not ideal for the majority of augmented patients. Breast conservation therapy with explantation and mastopexy might be appropriate for rare patients with large volumes of native breast tissue. Mastectomy with immediate reconstruction might be a more suitable choice for these patients.

  17. Twelve previously unknown phage genera are ubiquitous in global oceans.

    Science.gov (United States)

    Holmfeldt, Karin; Solonenko, Natalie; Shah, Manesh; Corrier, Kristen; Riemann, Lasse; Verberkmoes, Nathan C; Sullivan, Matthew B

    2013-07-30

    Viruses are fundamental to ecosystems ranging from oceans to humans, yet our ability to study them is bottlenecked by the lack of ecologically relevant isolates, resulting in "unknowns" dominating culture-independent surveys. Here we present genomes from 31 phages infecting multiple strains of the aquatic bacterium Cellulophaga baltica (Bacteroidetes) to provide data for an underrepresented and environmentally abundant bacterial lineage. Comparative genomics delineated 12 phage groups that (i) each represent a new genus, and (ii) represent one novel and four well-known viral families. This diversity contrasts the few well-studied marine phage systems, but parallels the diversity of phages infecting human-associated bacteria. Although all 12 Cellulophaga phages represent new genera, the podoviruses and icosahedral, nontailed ssDNA phages were exceptional, with genomes up to twice as large as those previously observed for each phage type. Structural novelty was also substantial, requiring experimental phage proteomics to identify 83% of the structural proteins. The presence of uncommon nucleotide metabolism genes in four genera likely underscores the importance of scavenging nutrient-rich molecules as previously seen for phages in marine environments. Metagenomic recruitment analyses suggest that these particular Cellulophaga phages are rare and may represent a first glimpse into the phage side of the rare biosphere. However, these analyses also revealed that these phage genera are widespread, occurring in 94% of 137 investigated metagenomes. Together, this diverse and novel collection of phages identifies a small but ubiquitous fraction of unknown marine viral diversity and provides numerous environmentally relevant phage-host systems for experimental hypothesis testing.

  18. Source apportionment of fine PM and sub-micron particle number concentrations at a regional background site in the western Mediterranean: a 2.5 year study

    Directory of Open Access Journals (Sweden)

    M. Cusack

    2013-05-01

    Full Text Available The chemical composition and sources of ambient fine particulate matter (PM1 over a period of 2.5 years for a regional background site in the western Mediterranean are presented in this work. Furthermore, sub-micron particle number concentrations and the sources of these particles are also presented. The mean PM1 concentration for the measurement period was 8.9 μg m−3, with organic matter (OM and sulphate comprising most of the mass (3.2 and 1.5 μg m−3 respectively. Six sources were identified in PM1 by Positive Matrix Factorisation (PMF: secondary organic aerosol, secondary nitrate, industrial, traffic + biomass burning, fuel oil combustion and secondary sulphate. Typically anthropogenic sources displayed elevated concentrations during the week with reductions at weekends. Nitrate levels were elevated in winter and negligible in summer, whereas secondary sulphate levels underwent a contrasting seasonal evolution with highest concentrations in summer, similar to the fuel oil combustion source. The SOA source was influenced by episodes of sustained pollution as a result of anticyclonic conditions occurring during winter, giving rise to thermal inversions and the accumulation of pollutants in the mixing layer. Increased levels in summer were owing to higher biogenic emissions and regional recirculation of air masses. The industrial source decreased in August due to decreased emissions during the vacation period. Increases in the traffic + biomass burning source were recorded in January, April and October, which were attributed to the occurrence of the aforementioned pollution episodes and local biomass burning emission sources, which include agriculture and domestic heating systems. Average particle number concentrations (N9-825 nm from 5/11/2010 to 01/06/2011 and from 15/10/2011 to 18/12/2011 reached 3097 cm−3. Five emission sources of particle of sub-micron particles were determined by Principal Component Analysis (PCA; industrial

  19. Maslowian Scale.

    Science.gov (United States)

    Falk, C.; And Others

    The development of the Maslowian Scale, a method of revealing a picture of one's needs and concerns based on Abraham Maslow's levels of self-actualization, is described. This paper also explains how the scale is supported by the theories of L. Kohlberg, C. Rogers, and T. Rusk. After a literature search, a list of statements was generated…

  20. Combined Nivolumab and Ipilimumab or Monotherapy in Previously Untreated Melanoma

    Science.gov (United States)

    Larkin, James; Chiarion-Sileni, Vanna; Gonzalez, Rene; Grob, Jean Jacques; Cowey, C. Lance; Lao, Christopher D.; Schadendorf, Dirk; Dummer, Reinhard; Smylie, Michael; Rutkowski, Piotr; Ferrucci, Pier Francesco; Hill, Andrew; Wagstaff, John; Carlino, Matteo S.; Haanen, John B.; Maio, Michele; Marquez-Rodas, Ivan; McArthur, Grant A.; Ascierto, Paolo A.; Long, Georgina V.; Callahan, Margaret K.; Postow, Michael A.; Grossmann, Kenneth; Sznol, Mario; Dreno, Brigitte; Bastholt, Lars; Yang, Arvin; Rollin, Linda M.; Horak, Christine; Hodi, F. Stephen; Wolchok, Jedd D.

    2017-01-01

    Background The results of phase 1 and phase 2 studies suggest that nivolumab (a PD-1 checkpoint inhibitor) and ipilimumab (a CTLA-4 checkpoint inhibitor) have complementary activity in metastatic melanoma. In this randomized, double-blind, phase 3 study, nivolumab alone or nivolumab combined with ipilimumab versus ipilimumab alone were evaluated in patients with metastatic melanoma. Methods We randomly assigned 945 previously untreated patients with unresectable stage III or IV melanoma, in 1:1:1 ratio, to nivolumab alone (3 mg per kilogram of body weight every 2 weeks), or to nivolumab (at a dose of 1 mg per kilogram) plus ipilimumab (at a dose of 3 mg per kilogram) every 3 weeks for 4 doses followed by nivolumab (3 mg per kilogram every 2 weeks), or to ipilimumab alone (3 mg per kilogram every 3 weeks for 4 doses). Progression-free and overall survival were co-primary end points. Patients continue to be followed for overall survival. Results Median progression-free survival was 11.5 months (95% confidence interval [CI], 8.9 to 16.7) for nivolumab plus ipilimumab as compared with 2.9 months (95% CI, 2.8 to 3.4) for ipilimumab alone (hazard ratio, 0.42; 95% CI, 0.31 to 0.57; Pnivolumab alone (hazard ratio in the comparison with ipilimumab alone, 0.57; 95% CI, 0.43 to 0.76; Pnivolumab plus ipilimumab and nivolumab alone groups, but in PD-L1-negative patients, progression-free survival was longer with the combination as compared with nivolumab alone (11.2 months [95% CI, 8.0 to not reached] versus 5.3 months [95% CI, 2.8 to 7.1]). Grade 3–4 drug-related adverse events occurred in 16.3%, 55.0%, and 27.3% of patients in the nivolumab, nivolumab plus ipilimumab, and ipilimumab alone groups, with 1, 0, and 1 drug-related deaths, respectively. Conclusions Nivolumab alone or combined with ipilimumab significantly improved progression-free survival, as compared with ipilimumab, among previously untreated patients with metastatic melanoma. Results with the combination

  1. 76 FR 6525 - Airworthiness Directives; Cessna Aircraft Company (Type Certificate Previously Held by Columbia...

    Science.gov (United States)

    2011-02-07

    ... Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing (Previously the Lancair... Aircraft Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing (Previously The... Aircraft Company (type certificate previously held by Columbia Aircraft Manufacturing (previously The...

  2. Disability progression in multiple sclerosis is slower than previously reported.

    Science.gov (United States)

    Tremlett, Helen; Paty, Donald; Devonshire, Virginia

    2006-01-24

    To investigate disease progression and risk factors in a large geographically based population with multiple sclerosis (MS), using two different inception points--clinical onset and date of birth. The authors reviewed a database of subjects with definite MS and symptom onset prior to July 1988. The main outcome was sustained progression to Expanded Disability Status Scale (EDSS) 6 (requires a cane), using the date of birth and date of MS onset as inception points in separate analyses. Risk factors examined were sex, relapsing vs primary progressive course, onset age, and onset symptoms. The study included 2,837 patients, followed prospectively for 22,723 patient years. The median time to EDSS 6 was 27.9 years, 15 years after onset; only 21% reached EDSS 6, and by age 50, 28% required a cane. Men progressed 38% more quickly than women from onset (p men and 60.1 for women (p = 0.082). A younger onset age predicted a slower progression, but those older at onset were consistently older when reaching EDSS 6. A primary progressive course predicted a more rapid progression from both onset (p multiple sclerosis (MS) accrued more slowly than found in earlier longitudinal studies. The authors also challenged two fundamental concepts in MS, demonstrating that neither male sex nor older onset age was associated with worse disease outcome.

  3. Multispecies Coevolution Particle Swarm Optimization Based on Previous Search History

    Directory of Open Access Journals (Sweden)

    Danping Wang

    2017-01-01

    Full Text Available A hybrid coevolution particle swarm optimization algorithm with dynamic multispecies strategy based on K-means clustering and nonrevisit strategy based on Binary Space Partitioning fitness tree (called MCPSO-PSH is proposed. Previous search history memorized into the Binary Space Partitioning fitness tree can effectively restrain the individuals’ revisit phenomenon. The whole population is partitioned into several subspecies and cooperative coevolution is realized by an information communication mechanism between subspecies, which can enhance the global search ability of particles and avoid premature convergence to local optimum. To demonstrate the power of the method, comparisons between the proposed algorithm and state-of-the-art algorithms are grouped into two categories: 10 basic benchmark functions (10-dimensional and 30-dimensional, 10 CEC2005 benchmark functions (30-dimensional, and a real-world problem (multilevel image segmentation problems. Experimental results show that MCPSO-PSH displays a competitive performance compared to the other swarm-based or evolutionary algorithms in terms of solution accuracy and statistical tests.

  4. Optimal temperature for malaria transmission is dramaticallylower than previously predicted

    Science.gov (United States)

    Mordecai, Eerin A.; Paaijmans, Krijin P.; Johnson, Leah R.; Balzer, Christian; Ben-Horin, Tal; de Moor, Emily; McNally, Amy; Pawar, Samraat; Ryan, Sadie J.; Smith, Thomas C.; Lafferty, Kevin D.

    2013-01-01

    The ecology of mosquito vectors and malaria parasites affect the incidence, seasonal transmission and geographical range of malaria. Most malaria models to date assume constant or linear responses of mosquito and parasite life-history traits to temperature, predicting optimal transmission at 31 °C. These models are at odds with field observations of transmission dating back nearly a century. We build a model with more realistic ecological assumptions about the thermal physiology of insects. Our model, which includes empirically derived nonlinear thermal responses, predicts optimal malaria transmission at 25 °C (6 °C lower than previous models). Moreover, the model predicts that transmission decreases dramatically at temperatures > 28 °C, altering predictions about how climate change will affect malaria. A large data set on malaria transmission risk in Africa validates both the 25 °C optimum and the decline above 28 °C. Using these more accurate nonlinear thermal-response models will aid in understanding the effects of current and future temperature regimes on disease transmission.

  5. Use of robotic colonoscopy in patients with previous incomplete colonoscopy.

    Science.gov (United States)

    Tumino, E; Parisi, G; Bertoni, M; Bertini, M; Metrangolo, S; Ierardi, E; Cervelli, R; Bresci, G; Sacco, R

    2017-02-01

    Conventional colonoscopy (CC) is the gold standard to diagnostic and therapeutic approach to colon. However, in few cases, cecal intubation could fail due to colon anatomy, patient compliance and physician expertise. Endotics robotic colonoscopy is a novel, safe, mini-invasive modality to explore the entire colon. Our aim was to assess, in a retrospective study, Endotics ability of cecal intubation in all cases in which CC failed. Between January 2008 and December 2012, 276 Endotics robotic colonscopy examinations were performed at the Gastroenterology and Metabolic Diseases Unit of Pisa University Hospital, Pisa, Italy, in a series of consecutive patients who had undergone CC and failed cecal intubation. We assessed the cecal intubation rate in 102 patients addressed to Endotics after previous incomplete CC. Overall, endotics system was successful in 93.1% of the incomplete conventional colonoscopy cases (95% performance). Whenever the intended exploration of the entire colon with CC failed, the endotics robotic endoscopy represented a useful tool as it helped examine the entire colon in almost all cases.

  6. Pleomorphic dermal sarcoma: a more aggressive neoplasm than previously estimated.

    Science.gov (United States)

    Tardío, Juan C; Pinedo, Fernando; Aramburu, José A; Suárez-Massa, Dolores; Pampín, Ana; Requena, Luis; Santonja, Carlos

    2016-02-01

    Pleomorphic dermal sarcoma (PDS) is a rare neoplasm sharing pathological features with atypical fibroxanthoma, but adding tumor necrosis, invasion beyond superficial subcutis or vascular or perineural infiltration. Although its metastatic risk has been estimated to be less than 5%, its real outcome is presently uncertain because of its rarity and to the lack of homogeneous criteria used in reported cases. Retrospective clinicopathological study of 18 cases of PDS. The lesions presented as tumors or plaques (size: 7-70 mm) on the head of elderly patients (median: 81 years), without a gender predominance. Histopathologically, they consisted of spindle cells arranged in a fascicular pattern, containing pleomorphic epithelioid and giant multinucleated cells in varying proportions, and usually exhibiting numerous mitotic figures and infiltrative tumor margins. No immunoexpression for cytokeratins, S100 protein, desmin or CD34 was observed. Necrosis and venous invasion were found in three tumors each (17%). Follow-up was available in 15 cases (median: 33 months). Three patients (20%) had local recurrences, all with incomplete primary surgical resections. Three patients (20%) developed distant metastases in the skin, regional lymph nodes and/or lungs and died from the disease. Our data suggest that PDS may be a more aggressive neoplasm than previously estimated. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Global functional atlas of Escherichia coli encompassing previously uncharacterized proteins.

    Directory of Open Access Journals (Sweden)

    Pingzhao Hu

    2009-04-01

    Full Text Available One-third of the 4,225 protein-coding genes of Escherichia coli K-12 remain functionally unannotated (orphans. Many map to distant clades such as Archaea, suggesting involvement in basic prokaryotic traits, whereas others appear restricted to E. coli, including pathogenic strains. To elucidate the orphans' biological roles, we performed an extensive proteomic survey using affinity-tagged E. coli strains and generated comprehensive genomic context inferences to derive a high-confidence compendium for virtually the entire proteome consisting of 5,993 putative physical interactions and 74,776 putative functional associations, most of which are novel. Clustering of the respective probabilistic networks revealed putative orphan membership in discrete multiprotein complexes and functional modules together with annotated gene products, whereas a machine-learning strategy based on network integration implicated the orphans in specific biological processes. We provide additional experimental evidence supporting orphan participation in protein synthesis, amino acid metabolism, biofilm formation, motility, and assembly of the bacterial cell envelope. This resource provides a "systems-wide" functional blueprint of a model microbe, with insights into the biological and evolutionary significance of previously uncharacterized proteins.

  8. Motivational activities based on previous knowledge of students

    Science.gov (United States)

    García, J. A.; Gómez-Robledo, L.; Huertas, R.; Perales, F. J.

    2014-07-01

    Academic results depend strongly on the individual circumstances of students: background, motivation and aptitude. We think that academic activities conducted to increase motivation must be tuned to the special situation of the students. Main goal of this work is analyze the students in the first year of the Degree in Optics and Optometry in the University of Granada and the suitability of an activity designed for those students. Initial data were obtained from a survey inquiring about the reasons to choose this degree, their knowledge of it, and previous academic backgrounds. Results show that: 1) the group is quite heterogeneous, since students have very different background. 2) Reasons to choose the Degree in Optics and Optometry are also very different, and in many cases were selected as a second option. 3) Knowledge and motivations about the Degree are in general quite low. Trying to increase the motivation of the students we designed an academic activity in which we show different topics studied in the Degree. Results show that students that have been involved in this activity are the most motivated and most satisfied with their election of the degree.

  9. High-Grade Leiomyosarcoma Arising in a Previously Replanted Limb

    Directory of Open Access Journals (Sweden)

    Tiffany J. Pan

    2015-01-01

    Full Text Available Sarcoma development has been associated with genetics, irradiation, viral infections, and immunodeficiency. Reports of sarcomas arising in the setting of prior trauma, as in burn scars or fracture sites, are rare. We report a case of a leiomyosarcoma arising in an arm that had previously been replanted at the level of the elbow joint following traumatic amputation when the patient was eight years old. He presented twenty-four years later with a 10.8 cm mass in the replanted arm located on the volar forearm. The tumor was completely resected and pathology examination showed a high-grade, subfascial spindle cell sarcoma diagnosed as a grade 3 leiomyosarcoma with stage pT2bNxMx. The patient underwent treatment with brachytherapy, reconstruction with a free flap, and subsequently chemotherapy. To the best of our knowledge, this is the first case report of leiomyosarcoma developing in a replanted extremity. Development of leiomyosarcoma in this case could be related to revascularization, scar formation, or chronic injury after replantation. The patient remains healthy without signs of recurrence at three-year follow-up.

  10. Measles Outbreak among Previously Immunized Adult Healthcare Workers, China, 2015

    Directory of Open Access Journals (Sweden)

    Zhengyi Zhang

    2016-01-01

    Full Text Available Measles is caused by measles virus belonging to genus Morbillivirus of the family Paramyxoviridae. Vaccination has played a critical role in controlling measles infection worldwide. However, in the recent years, outbreaks of measles infection still occur in many developing countries. Here, we report an outbreak of measles among healthcare workers and among the 60 measles infected patients 50 were healthcare workers including doctors, nurses, staff, and medics. Fifty-one patients (85% tested positive for IgM antibodies against the measles virus and 50 patients (83.3% tested positive for measles virus RNA. Surprisingly, 73.3% of the infected individuals had been previously immunized against measles. Since there is no infection division in our hospital, the fever clinics are located in the Emergency Division. In addition, the fever and rash were not recognized as measles symptoms at the beginning of the outbreak. These factors result in delay in isolation and early confirmation of the suspected patients and eventually a measles outbreak in the hospital. Our report highlights the importance of following a two-dose measles vaccine program in people including the healthcare workers. In addition, vigilant attention should be paid to medical staff with clinical fever and rash symptoms to avoid a possible nosocomial transmission of measles infection.

  11. Abiraterone in metastatic prostate cancer without previous chemotherapy.

    Science.gov (United States)

    Ryan, Charles J; Smith, Matthew R; de Bono, Johann S; Molina, Arturo; Logothetis, Christopher J; de Souza, Paul; Fizazi, Karim; Mainwaring, Paul; Piulats, Josep M; Ng, Siobhan; Carles, Joan; Mulders, Peter F A; Basch, Ethan; Small, Eric J; Saad, Fred; Schrijvers, Dirk; Van Poppel, Hendrik; Mukherjee, Som D; Suttmann, Henrik; Gerritsen, Winald R; Flaig, Thomas W; George, Daniel J; Yu, Evan Y; Efstathiou, Eleni; Pantuck, Allan; Winquist, Eric; Higano, Celestia S; Taplin, Mary-Ellen; Park, Youn; Kheoh, Thian; Griffin, Thomas; Scher, Howard I; Rathkopf, Dana E

    2013-01-10

    Abiraterone acetate, an androgen biosynthesis inhibitor, improves overall survival in patients with metastatic castration-resistant prostate cancer after chemotherapy. We evaluated this agent in patients who had not received previous chemotherapy. In this double-blind study, we randomly assigned 1088 patients to receive abiraterone acetate (1000 mg) plus prednisone (5 mg twice daily) or placebo plus prednisone. The coprimary end points were radiographic progression-free survival and overall survival. The study was unblinded after a planned interim analysis that was performed after 43% of the expected deaths had occurred. The median radiographic progression-free survival was 16.5 months with abiraterone-prednisone and 8.3 months with prednisone alone (hazard ratio for abiraterone-prednisone vs. prednisone alone, 0.53; 95% confidence interval [CI], 0.45 to 0.62; Pchemotherapy, opiate use for cancer-related pain, prostate-specific antigen progression, and decline in performance status. Grade 3 or 4 mineralocorticoid-related adverse events and abnormalities on liver-function testing were more common with abiraterone-prednisone. Abiraterone improved radiographic progression-free survival, showed a trend toward improved overall survival, and significantly delayed clinical decline and initiation of chemotherapy in patients with metastatic castration-resistant prostate cancer. (Funded by Janssen Research and Development, formerly Cougar Biotechnology; ClinicalTrials.gov number, NCT00887198.).

  12. Influence of Previous Knowledge in Torrance Tests of Creative Thinking

    Directory of Open Access Journals (Sweden)

    María Aranguren

    2015-07-01

    Full Text Available The aim of this work is to analyze the influence of study field, expertise and recreational activities participation in Torrance Tests of Creative Thinking (TTCT, 1974 performance. Several hypotheses were postulated to explore the possible effects of previous knowledge in TTCT verbal and TTCT figural university students’ outcomes. Participants in this study included 418 students from five study fields: Psychology;Philosophy and Literature, Music; Engineering; and Journalism and Advertising (Communication Sciences. Results found in this research seem to indicate that there in none influence of the study field, expertise and recreational activities participation in neither of the TTCT tests. Instead, the findings seem to suggest some kind of interaction between certain skills needed to succeed in specific studies fields and performance on creativity tests, such as the TTCT. These results imply that TTCT is a useful and valid instrument to measure creativity and that some cognitive process involved in innovative thinking can be promoted using different intervention programs in schools and universities regardless the students study field.

  13. Cerebral Metastasis from a Previously Undiagnosed Appendiceal Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Antonio Biroli

    2012-01-01

    Full Text Available Brain metastases arise in 10%–40% of all cancer patients. Up to one third of the patients do not have previous cancer history. We report a case of a 67-years-old male patient who presented with confusion, tremor, and apraxia. A brain MRI revealed an isolated right temporal lobe lesion. A thorax-abdomen-pelvis CT scan showed no primary lesion. The patient underwent a craniotomy with gross-total resection. Histopathology revealed an intestinal-type adenocarcinoma. A colonoscopy found no primary lesion, but a PET-CT scan showed elevated FDG uptake in the appendiceal nodule. A right hemicolectomy was performed, and the specimen showed a moderately differentiated mucinous appendiceal adenocarcinoma. Whole brain radiotherapy was administrated. A subsequent thorax-abdomen CT scan revealed multiple lung and hepatic metastasis. Seven months later, the patient died of disease progression. In cases of undiagnosed primary lesions, patients present in better general condition, but overall survival does not change. Eventual identification of the primary tumor does not affect survival. PET/CT might be a helpful tool in detecting lesions of the appendiceal region. To the best of our knowledge, such a case was never reported in the literature, and an appendiceal malignancy should be suspected in patients with brain metastasis from an undiagnosed primary tumor.

  14. Effect of Previous Gastrectomy on the Performance of Postoperative Colonoscopy

    Science.gov (United States)

    Kim, Sunghwan; Choi, Jeongmin; Kim, Tae Han; Suh, Yun-Suhk; Im, Jong Pil; Lee, Hyuk-Joon; Kim, Sang Gyun; Jeong, Seung-Yong; Kim, Joo Sung; Yang, Han-Kwang

    2016-01-01

    Purpose The purpose of this study was to determine the effect of a prior gastrectomy on the difficulty of subsequent colonoscopy, and to identify the surgical factors related to difficult colonoscopies. Materials and Methods Patients with a prior gastrectomy who had undergone a colonoscopy between 2011 and 2014 (n=482) were matched (1:6) to patients with no history of gastrectomy (n=2,892). Cecal insertion time, intubation failure, and bowel clearance score were compared between the gastrectomy and control groups, as was a newly generated comprehensive parameter for a difficult/incomplete colonoscopy (cecal intubation failure, cecal insertion time >12.9 minutes, or very poor bowel preparation scale). Surgical factors including surgical approach, extent of gastrectomy, extent of lymph node dissection, and reconstruction type, were analyzed to identify risk factors for colonoscopy performance. Results A history of gastrectomy was associated with prolonged cecal insertion time (8.7±6.4 vs. 9.7±6.5 minutes; P=0.002), an increased intubation failure rate (0.1% vs. 1.9%; P<0.001), and a poor bowel preparation rate (24.7 vs. 29.0; P=0.047). Age and total gastrectomy (vs. partial gastrectomy) were found to be independent risk factors for increased insertion time, which slowly increased throughout the postoperative duration (0.35 min/yr). Total gastrectomy was the only independent risk factor for the comprehensive parameter of difficult/incomplete colonoscopy. Conclusions History of gastrectomy is related to difficult/incomplete colonoscopy performance, especially in cases of total gastrectomy. In any case, it may be that a pre-operative colonoscopy is desirable in selected patients scheduled for gastrectomy; however, it should be performed by an expert endoscopist each time. PMID:27752394

  15. Gastrointestinal tolerability with ibandronate after previous weekly bisphosphonate treatment

    Directory of Open Access Journals (Sweden)

    Richard Derman

    2009-09-01

    Full Text Available Richard Derman1, Joseph D Kohles2, Ann Babbitt31Department of Obstetrics and Gynecology, Christiana Hospital, Newark, DE, USA; 2Roche, Nutley, NJ, USA; 3Greater Portland Bone and Joint Specialists, Portland, ME, USAAbstract: Data from two open-label trials (PRIOR and CURRENT of women with postmenopausal osteoporosis or osteopenia were evaluated to assess whether monthly oral and quarterly intravenous (IV ibandronate dosing improved self-reported gastrointestinal (GI tolerability for patients who had previously experienced GI irritation with bisphosphonate (BP use. In PRIOR, women who had discontinued daily or weekly BP treatment due to GI intolerance received monthly oral or quarterly IV ibandronate for 12 months. The CURRENT subanalysis included women receiving weekly BP treatment who switched to monthly oral ibandronate for six months. GI symptom severity and frequency were assessed using the Osteoporosis Patient Satisfaction Questionnaire™. In PRIOR, mean GI tolerability scores increased significantly at month 1 from screening for both treatment groups (oral: 79.3 versus 54.1; IV: 84.4 versus 51.0; p < 0.001 for both. Most patients reported improvement in GI symptom severity and frequency from baseline at all post-screening assessments (>90% at Month 10. In the CURRENT subanalysis >60% of patients reported improvements in heartburn or acid reflux and >70% indicated improvement in other stomach upset at month 6. Postmenopausal women with GI irritability with daily or weekly BPs experienced improvement in symptoms with extended dosing monthly or quarterly ibandronate compared with baseline.Keywords: ibandronate, osteoporosis, bisphosphonate, gastrointestinal

  16. Rosiglitazone and myocardial infarction in patients previously prescribed metformin.

    Directory of Open Access Journals (Sweden)

    Colin R Dormuth

    Full Text Available OBJECTIVE: Rosiglitazone was found associated with approximately a 43% increase in risk of acute myocardial infarction (AMI in a two meta-analyses of clinical trials. Our objective is to estimate the magnitude of the association in real-world patients previously treated with metformin. RESEARCH DESIGN AND METHODS: We conducted a nested case control study in British Columbia using health care databases on 4.3 million people. Our cohort consisted of 158,578 patients with Type 2 diabetes who used metformin as first-line drug treatment. We matched 2,244 cases of myocardial infarction (AMI with up to 4 controls. Conditional logistic regression models were used to estimate matched odds ratios for AMI associated with treatment with rosiglitazone, pioglitazone and sulfonylureas. RESULTS: In our cohort of prior metformin users, adding rosiglitazone for up to 6 months was not associated with an increased risk of AMI compared to adding a sulfonylurea (odds ratio [OR] 1.38; 95% confidence interval [CI], 0.91-2.10, or compared to adding pioglitazone (OR for rosi versus pio 1.41; 95% CI, 0.74-2.66. There were also no significant differences between rosiglitazone, pioglitazone and sulfonylureas for longer durations of treatment. Though not significantly different from sulfonylureas, there was a transient increase in AMI risk associated with the first 6 months of treatment with a glitazone compared to not using the treatment (OR 1.53; 95% CI, 1.13-2.07 CONCLUSIONS: In our British Columbia cohort of patients who received metformin as first-line pharmacotherapy for Type 2 diabetes mellitus, further treatment with rosiglitazone did not increase the risk of AMI compared to patients who were treated with pioglitazone or a sulfonylurea. Though not statistically significantly different compared from each other, an increased risk of AMI observed after starting rosiglitazone or sulfonylureas is a matter of concern that requires more research.

  17. Repeat immigration: A previously unobserved source of heterogeneity?

    Science.gov (United States)

    Aradhya, Siddartha; Scott, Kirk; Smith, Christopher D

    2017-07-01

    Register data allow for nuanced analyses of heterogeneities between sub-groups which are not observable in other data sources. One heterogeneity for which register data is particularly useful is in identifying unique migration histories of immigrant populations, a group of interest across disciplines. Years since migration is a commonly used measure of integration in studies seeking to understand the outcomes of immigrants. This study constructs detailed migration histories to test whether misclassified migrations may mask important heterogeneities. In doing so, we identify a previously understudied group of migrants called repeat immigrants, and show that they differ systematically from permanent immigrants. In addition, we quantify the degree to which migration information is misreported in the registers. The analysis is carried out in two steps. First, we estimate income trajectories for repeat immigrants and permanent immigrants to understand the degree to which they differ. Second, we test data validity by cross-referencing migration information with changes in income to determine whether there are inconsistencies indicating misreporting. From the first part of the analysis, the results indicate that repeat immigrants systematically differ from permanent immigrants in terms of income trajectories. Furthermore, income trajectories differ based on the way in which years since migration is calculated. The second part of the analysis suggests that misreported migration events, while present, are negligible. Repeat immigrants differ in terms of income trajectories, and may differ in terms of other outcomes as well. Furthermore, this study underlines that Swedish registers provide a reliable data source to analyze groups which are unidentifiable in other data sources.

  18. Previously unidentified morbidity in patients with intellectual disability

    Science.gov (United States)

    Baxter, Helen; Lowe, Kathy; Houston, Helen; Jones, Glyn; Felce, David; Kerr, Michael

    2006-01-01

    Background Adults with a learning disability frequently have unmet health needs. The cause for this is complex and may be related to difficulties in accessing usual primary care services. Health checks have been widely recommended as a solution to this need. Aim To determine the likelihood that a structured health check by the primary care team supported by appropriate education would identify and treat previously unrecognised morbidity in adults with an intellectual disability. Design of study Individuals were identified within primary care teams and a structured health check performed by the primary care team. This process was supported by an educational resource. Face-to-face audit with the team was performed 3 months following the check. Setting Forty general practices within three health authorities in south and mid-Wales participated. They had a combined registered patient population of 354 000. Method Health checks were conducted for 190 (60%) of 318 identified individuals; 128 people moved, died, withdrew from the study, or refused to participate. Results Complete data were available on 181 health checks; 51% had new needs recognised, of whom 63% had one health need, 25% two health needs, and 12% more than two. Sixteen patients (9%) had serious new morbidity discovered. Management had been initiated for 93% of the identified health needs by the time of audit. This study is the first to identify new disease findings in a primary care population and the likelihood that such disease will be treated. Conclusions The findings reflect a concern that current care delivery leaves adults with an intellectual disability at risk of both severe and milder illness going unrecognised. Health checks present one mechanism for identifying and treating such illness in primary care. PMID:16464321

  19. Sacrococcygeal pilonidal disease: analysis of previously proposed risk factors

    Directory of Open Access Journals (Sweden)

    Ali Harlak

    2010-01-01

    Full Text Available PURPOSE: Sacrococcygeal pilonidal disease is a source of one of the most common surgical problems among young adults. While male gender, obesity, occupations requiring sitting, deep natal clefts, excessive body hair, poor body hygiene and excessive sweating are described as the main risk factors for this disease, most of these need to be verified with a clinical trial. The present study aimed to evaluate the value and effect of these factors on pilonidal disease. METHOD: Previously proposed main risk factors were evaluated in a prospective case control study that included 587 patients with pilonidal disease and 2,780 healthy control patients. RESULTS: Stiffness of body hair, number of baths and time spent seated per day were the three most predictive risk factors. Adjusted odds ratios were 9.23, 6.33 and 4.03, respectively (p<0.001. With an adjusted odds ratio of 1.3 (p<.001, body mass index was another risk factor. Family history was not statistically different between the groups and there was no specific occupation associated with the disease. CONCLUSIONS: Hairy people who sit down for more than six hours a day and those who take a bath two or less times per week are at a 219-fold increased risk for sacrococcygeal pilonidal disease than those without these risk factors. For people with a great deal of hair, there is a greater need for them to clean their intergluteal sulcus. People who engage in work that requires sitting in a seat for long periods of time should choose more comfortable seats and should also try to stand whenever possible.

  20. Framing scales and scaling frames

    NARCIS (Netherlands)

    Lieshout, van M.; Dewulf, A.; Aarts, M.N.C.; Termeer, C.J.A.M.

    2009-01-01

    Policy problems are not just out there. Actors highlight different aspects of a situation as problematic and situate the problem on different scales. In this study we will analyse the way actors apply scales in their talk (or texts) to frame the complex decision-making process of the establishment

  1. Challenging comparison of stroke scales

    Directory of Open Access Journals (Sweden)

    Kavian Ghandehari

    2013-01-01

    Full Text Available Stroke scales can be classified as clinicometric scales and functional impairment, handicap scales. All studies describing stroke scales were reviewed by internet searching engines with the final search performed on January 1, 2013. The following string of keywords was entered into search engines; stroke, scale, score and disability. Despite advantages of modified National Institute of Health Stroke Scale and Scandinavian stroke scale comparing to the NIHSS, including their simplification and less inter-rater variability; most of the stroke neurologists around the world continue using the NIHSS. The modified Rankin scale (mRS and Barthel index (BI are widely used functional impairment and disability scales. Distinction between grades of mRS is poorly defined. The Asian stroke disability scale is a simplified functional impairment, handicap scale which is as valid as mRS and BI. At the present time, the NIHSS, mRS and BI are routine stroke scales because physicians have used to work with these scales for more than two decades, although it could not be an acceptable reason. On the other side, results of previous stroke trials, which are the basis of stroke management guidelines are driven using these scales.

  2. Image-Guided Ultrasound Characterization of Volatile Sub-Micron Phase-Shift Droplets in the 20-40 MHz Frequency Range.

    Science.gov (United States)

    Sheeran, Paul S; Daghighi, Yasaman; Yoo, Kimoon; Williams, Ross; Cherin, Emmanuel; Foster, F Stuart; Burns, Peter N

    2016-03-01

    Phase-shift perfluorocarbon droplets are designed to convert from the liquid to the gas state by the external application of acoustic or optical energy. Although droplet vaporization has been investigated extensively at ultrasonic frequencies between 1 and 10 MHz, few studies have characterized performance at the higher frequencies commonly used in small animal imaging. In this study, we use standard B-mode imaging sequences on a pre-clinical ultrasound platform to both image and activate sub-micron decafluorobutane droplet populations in vitro and in vivo at center frequencies in the range of 20-40 MHz. Results show that droplets remain stable against vaporization at low imaging pressures but are vaporized at peak negative pressures near 3.5 MPa at the three frequencies tested. This study also found that a small number of size outliers present in the distribution can greatly influence droplet performance. Removal of these outliers results in a more accurate assessment of the vaporization threshold and produces free-flowing microbubbles upon vaporization in the mouse kidney. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  3. Synthesis and self-assembly of dumbbell shaped ZnO sub-micron structures using low temperature chemical bath deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Borade, P. [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India); Joshi, K.U. [Anton-Paar India Pvt. Ltd., Thane (W), 400607 (India); Gokarna, A.; Lerondel, G. [Laboratoire de Nanotechnologie et D' Instrumentation Optique, Institut Charles Delaunay, CNRS UMR 6281, Université de Technologie de Troyes, 12 Rue Marie Curie, BP 2060, 10010 Troyes (France); Walke, P. [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India); Late, D. [National Chemical Laboratory (NCL), Pune 400027 (India); Jejurikar, S.M., E-mail: jejusuhas@gmail.com [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India)

    2016-02-01

    We report well dispersed horizontal growth of ZnO sub-micron structures using simplest technique ever known i.e. chemical bath deposition (CBD). A set of samples were prepared under two different cases A) dumbbell shaped ZnO grown in CBD bath and B) tubular ZnO structures evolved from dumbbell shaped structures by dissolution mechanism. Single phase wurtzite ZnO formation is confirmed using X-ray diffraction (XRD) technique in both cases. From the morphological investigations performed using scanning electron microscopy (SEM), sample prepared under case A indicate formation of hex bit tool (HBT) shaped ZnO crystals, which observed to self-organize to form dumbbell structures. Further these microstructures are then converted into tubular structures as a fragment of post CBD process. The possible mechanism responsible for the self-assembly of HBT units to form dumbbell structures is discussed. Observed free excitonic peak located at 370 nm in photoluminescence (PL) spectra recorded at 18 K indicate that the micro/nanostructures synthesized using CBD are of high optical quality. - Highlights: • Controlled growth of Dumbbell shaped ZnO using Chemical Bath Deposition (CBD). • Growth mechanism of dumbbell shaped ZnO by self-assembling was discussed. • Quick Transformation of ZnO dumbbell structures in to tubular structures by dissolution. • Sharp UV Emission at 370 nm from both dumbbell and tubular structures.

  4. Post-processing optimization of electrospun submicron poly(3-hydroxybutyrate) fibers to obtain continuous films of interest in food packaging applications.

    Science.gov (United States)

    Cherpinski, Adriane; Torres-Giner, Sergio; Cabedo, Luis; Lagaron, Jose M

    2017-10-01

    Polyhydroxyalkanoates (PHAs) are one of the most researched family of biodegradable polymers based on renewable materials due to their thermoplastic nature and moisture resistance. The present study was targeted to investigate the preparation and characterization of poly(3-hydroxybutyrate) (PHB) films obtained through the electrospinning technique. To convert them into continuous films and then to increase their application interest in packaging, the electrospun fiber mats were subsequently post-processed by different physical treatments. Thus, the effect of annealing time and cooling method on morphology, molecular order, thermal, optical, mechanical, and barrier properties of the electrospun submicron PHB fibers was studied. Annealing at 160°C, well below the homopolyester melting point, was found to be the minimum temperature at which homogeneous transparent films were produced. The film samples that were cooled slowly after annealing showed the lowest permeability to oxygen, water vapor, and limonene. The optimally post-processed electrospun PHB fibers exhibited similar rigidity to conventional compression-molded PHA films, but with enhanced elongation at break and toughness. Films made by this electrospinning technique have many potential applications, such as in the design of barrier layers, adhesive interlayers, and coatings for fiber- and plastic-based food packaging materials.

  5. High-performance UV and DUV lenses for projection-lithographic generation of submicron patterns down to 0.4 μm

    Science.gov (United States)

    Merkel, Klaus; Hofmann, Christian

    1990-07-01

    Manufacturing of modern microelectronic circuits requires projection- lithographic generation of submicron patterns by using high-aperture diffraction-limited UV- and DUV-lenses. Realized image quality of such high-performance leiises is mainly determined by the control of the extremly narrowed fabrication tolerances by new developed special high technologies for production and measurement of such lenses1. Contactless optical precision measurement of surfacy topography, thickness, distances, and decentring of optical elements , computer-controlled correction polishing" , manufacturing of nanometer-asperic surfaces by CNC-correction polishing or by ion-beam etching, computer-assisted assembly , wave- front analysis on the basis of measurement of geometrical-optical beam aberrations, and image quality testing with near-coherent illumination are such new techniques. The correction of such lenses is more difficult because the available optical media are limited to those which sufficiently good transmission in the UV resp. DUV region. Optical media used in DUV-lenses are fused silica glass, calcium or barium fluoride, and eventually fluorphosphate crown glass. This media restriction leads to an increase in number of lenses, constructional length, and technological difficulties in the manufacturing.

  6. Bottom-up synthesis of up-converting submicron-sized Er{sup 3+}-doped LiNbO{sub 3} particles

    Energy Technology Data Exchange (ETDEWEB)

    Jardiel, T., E-mail: jardiel@icv.csic.es [Departamento de Electroceramica, Instituto de Ceramica y Vidrio-CSIC, Kelsen 5, 28049 Madrid (Spain); Caballero, A.C. [Departamento de Electroceramica, Instituto de Ceramica y Vidrio-CSIC, Kelsen 5, 28049 Madrid (Spain); Marin-Dobrincic, M.; Cantelar, E.; Cusso, F. [Departamento de Fisica de Materiales, C-04, Facultad de Ciencias, Universidad Autonoma de Madrid, Avda. Francisco Tomas y Valiente 7, 28049 Madrid (Spain)

    2012-08-15

    A new and simple wet chemical synthesis method is proposed to prepare submicron-sized Erbium-doped LiNbO{sub 3} powders. The synthesis procedure comprises the co-precipitation of lithium and erbium ions from common precursors and their subsequent reaction with niobium ethoxide. A systematic characterization by means of X-Ray Diffraction (XRD), X-ray Fluorescence (XRF), Inductively Coupled Plasma (ICP-OES), Atomic Absorption (AAS), Field Emission Scanning Electron Microscopy (FE-SEM), as well as by the examination of the luminescence properties, evidence that with this method a congruent Er{sup 3+}-doped LiNbO{sub 3} single phase material can be obtained without using complex and time-consuming processing steps. The synthesized powders exhibit efficient IR to VIS up-conversion emissions under 974 nm pumping. -- Highlights: Black-Right-Pointing-Pointer A novel chemical route to the preparation of LiNbO{sub 3} powders has been developed. Black-Right-Pointing-Pointer This process avoids complex and time-consuming processing steps. Black-Right-Pointing-Pointer A congruent Er{sup 3+}-doped LiNbO{sub 3} single phase material can be obtained by this way. Black-Right-Pointing-Pointer The luminescence properties are the expected for this composition.

  7. The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols

    Science.gov (United States)

    Smith, J. D.; Kroll, J. H.; Cappa, C. D.; Che, D. L.; Liu, C. L.; Ahmed, M.; Leone, S. R.; Worsnop, D. R.; Wilson, K. R.

    2009-05-01

    The heterogeneous reaction of OH radicals with sub-micron squalane particles, in the presence of O2, is used as a model system to explore the fundamental chemical mechanisms that control the oxidative aging of organic aerosols in the atmosphere. Detailed kinetic measurements combined with elemental mass spectrometric analysis reveal that the reaction proceeds sequentially by adding an average of one oxygenated functional group per reactive loss of squalane. The reactive uptake coefficient of OH with squalane particles is determined to be 0.3±0.07 at an average OH concentration of ~1×1010 molecules cm-3. Based on a comparison between the measured particle mass and model predictions it appears that significant volatilization of a reduced organic particle would be extremely slow in the real atmosphere. However, as the aerosols become more oxygenated, volatilization becomes a significant loss channel for organic material in the particle-phase. Together these results provide a chemical framework in which to understand how heterogeneous chemistry transforms the physiochemical properties of particle-phase organic matter in the troposphere.

  8. The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols

    Directory of Open Access Journals (Sweden)

    J. D. Smith

    2009-05-01

    Full Text Available The heterogeneous reaction of OH radicals with sub-micron squalane particles, in the presence of O2, is used as a model system to explore the fundamental chemical mechanisms that control the oxidative aging of organic aerosols in the atmosphere. Detailed kinetic measurements combined with elemental mass spectrometric analysis reveal that the reaction proceeds sequentially by adding an average of one oxygenated functional group per reactive loss of squalane. The reactive uptake coefficient of OH with squalane particles is determined to be 0.3±0.07 at an average OH concentration of ~1×1010 molecules cm−3. Based on a comparison between the measured particle mass and model predictions it appears that significant volatilization of a reduced organic particle would be extremely slow in the real atmosphere. However, as the aerosols become more oxygenated, volatilization becomes a significant loss channel for organic material in the particle-phase. Together these results provide a chemical framework in which to understand how heterogeneous chemistry transforms the physiochemical properties of particle-phase organic matter in the troposphere.

  9. Sub-micron Polymer–Zeolitic Imidazolate Framework Layered Hybrids via Controlled Chemical Transformation of Naked ZnO Nanocrystal Films

    Energy Technology Data Exchange (ETDEWEB)

    Meckler, Stephen M.; Li, Changyi; Queen, Wendy L.; Williams, Teresa E.; Long, Jeffrey R.; Buonsanti, Raffaella; Milliron, Delia J.; Helms, Brett A.

    2015-11-24

    Here we show that sub-micron coatings of zeolitic imidazolate frameworks (ZIFs) and even ZIF–ZIF bilayers can be grown directly on polymers of intrinsic microporosity from zinc oxide (ZnO) nanocrystal precursor films, yielding a new class of all-microporous layered hybrids. The ZnO-to-ZIF chemical transformation proceeded in less than 30 min under microwave conditions using a solution of the imidazole ligand in N,N-dimethylformamide (DMF), water, or mixtures thereof. By varying the ratio of DMF to water, it was possible to control the morphology of the ZIF-on-polymer from isolated crystallites to continuous films. Grazing incidence X-ray diffraction was used to confirm the presence of crystalline ZIF in the thin films, and X-ray absorption spectroscopy was used to quantify film purity, revealing films with little to no residual ZnO. The role solvent plays in the transformation mechanism is discussed in light of these findings, which suggest the ZnO nanocrystals may be necessary to localize heterogeneous nucleation of the ZIF to the polymer surface.

  10. Sub-micron Polymer–Zeolitic Imidazolate Framework Layered Hybrids via Controlled Chemical Transformation of Naked ZnO Nanocrystal Films

    Energy Technology Data Exchange (ETDEWEB)

    Meckler, Stephen M.; Li, Changyi; Queen, Wendy L. [Department; Williams, Teresa E.; Long, Jeffrey R.; Buonsanti, Raffaella; Milliron, Delia J. [McKetta; Helms, Brett A.

    2015-11-02

    Here we show that sub-micron coatings of zeolitic imidazolate frameworks (ZIFs) and even ZIF–ZIF bilayers can be grown directly on polymers of intrinsic microporosity from zinc oxide (ZnO) nanocrystal precursor films, yielding a new class of all-microporous layered hybrids. The ZnO-to-ZIF chemical transformation proceeded in less than 30 min under microwave conditions using a solution of the imidazole ligand in N,N-dimethylformamide (DMF), water, or mixtures thereof. By varying the ratio of DMF to water, it was possible to control the morphology of the ZIF-on-polymer from isolated crystallites to continuous films. Grazing incidence X-ray diffraction was used to confirm the presence of crystalline ZIF in the thin films, and X-ray absorption spectroscopy was used to quantify film purity, revealing films with little to no residual ZnO. The role solvent plays in the transformation mechanism is discussed in light of these findings, which suggest the ZnO nanocrystals may be necessary to localize heterogeneous nucleation of the ZIF to the polymer surface.

  11. Spectroscopy of asteroid pairs - new observations support previous conclusions

    Science.gov (United States)

    Polishook, David; Oszkiewicz, Dagmara Anna; None Kwiatkowski, Tomasz

    2015-08-01

    Asteroid pairs were split due to fast rotation of a strengthless body. Study them can reveal fundamental principles in asteroid interiors and evolution. We continue our spectroscopic survey of asteroid pairs in the near-IR range (IRTF) and work on completing the spectral coverage in the visible wavelength (SALT, NOT).Our new observations support our previous conclusions (Polishook et al. 2014):1. Primary and secondary members have very similar reflectance spectra supporting the claim that every pair originated from a single progenitor. We measured 2 more pairs that present the same taxonomy (4905-7813, 15107-291188). This increases to 22 the number of asteroid pairs with spectral similarities and supports the claim of a single progenitor for each pair to a significance of over 5 sigma.2. Rotational fission is not a function of the asteroid composition rather the asteroid’s structure. We present new reflectance spectra of S- and C-complex pairs that differ in their composition.3. Some asteroid pairs present spectral parameters that imply a fresh, non-weathered surface. This includes spectral slope, and a deep and wide absorption band at 1 micron. Among these, the asteroid 8306 can now be re-classified as a Q-type asteroid, a common class in the near-Earth environment, but rare in the main belt. 8306 is the 4th Q-type discovered within asteroid pairs (all locate in the main belt).4. A secondary member of an asteroid pair composed of ordinary chondrite (S-complex) might present a reflectance spectrum with lower spectral slope compared to its primary member. This is seen in the new measured reflectance spectrum of secondary 291188). This result supports the theory of Jacobson & Scheeres (2011) of continuous disintegration of the secondaries while still in the vicinity of their primaries.5. With time, the fresh surface becomes weathered. Dynamical calculations limit the disintegration time of the progenitor of the pair 4905-7813 to 1.65 millions years ago, what makes

  12. The Yellowstone magma reservoir is 50% larger than previously imaged

    Science.gov (United States)

    Farrell, J.; Smith, R. B.; Husen, S.

    2013-12-01

    Earlier tomographic studies of the Yellowstone crustal magma system have revealed a low P-wave crustal anomaly beneath the 0.64 Ma Yellowstone caldera that has been interpreted to be the magma reservoir of partial melt that provides the thermal energy for Yellowstone's youthful volcanic and hydrothermal systems. The Yellowstone seismic network has evolved over the last decade into a modern real-time volcano monitoring system that consists of 36 short-period, broadband, and borehole seismometers that cover the entire Yellowstone volcanic field and surrounding tectonic areas. Until recently, limited seismograph coverage did not provide for adequate resolution of the velocity structure northeast of the caldera, an area of the largest negative Bouguer gravity field of -60 mGal whose 3D density model reveals a shallow, low density body that extends ~20 km northeast of the caldera. Recent upgrades to the Yellowstone Seismic Network (YSN), including the addition of nine 3-component and broadband seismic stations providing much better ray coverage of the entire Yellowstone area with greater bandwidth data. This allows much-expanded and improved resolution coverage of the Yellowstone crustal velocity structure. We have compiled waveforms for the Yellowstone earthquake catalog from 1984-2011 with 45,643 earthquakes and 1,159,724 waveforms to analyze P-wave arrival times with an automatic picker based on an adaptive high-fidelity human mimicking algorithm. Our analysis reduced the data to the 4,520 best-located earthquakes with 48,622 P-wave arrival times to invert for the velocity structure. The resulting 3D P-wave model reveals a low Vp body (up to -7% ΔVp) that is interpreted to be the Yellowstone crustal magma reservoir and is ~50% larger than previously imaged. It extends as an oblong shaped anomalous body ~90 km NE-SW, ~20 km NE of the 0.64 Ma caldera, and up to 30 km wide and markedly shallowing from 15 km depth beneath the caldera to less than ~2 km deep northeast of

  13. Tubal anastomosis after previous sterilization: a systematic review.

    Science.gov (United States)

    van Seeters, Jacoba A H; Chua, Su Jen; Mol, Ben W J; Koks, Carolien A M

    2017-05-01

    Female sterilization is one of the most common contraceptive methods. A small number of women, however, opt for reversal of sterilization procedures after they experience regret. Procedures can be performed by laparotomy or laparoscopy, with or without robotic assistance. Another commonly utilized alternative is IVF. The choice between surgery and IVF is often influenced by reimbursement politics for that particular geographic location. We evaluated the fertility outcomes of different surgical methods available for the reversal of female sterilization, compared these to IVF and assessed the prognostic factors for success. Two search strategies were employed. Firstly, we searched for randomized and non-randomized clinical studies presenting fertility outcomes of sterilization reversal up to July 2016. Data on the following outcomes were collected: pregnancy rate, ectopic pregnancy rate, cost of the procedure and operative time. Eligible study designs included prospective or retrospective studies, randomized controlled trials, cohort studies, case-control studies and case series. No age restriction was applied. Exclusion criteria were patients suffering from tubal infertility from any other reason (e.g. infection, endometriosis and adhesions from previous surgery) and studies including sterilization reversal procedures were then evaluated: female age, BMI and duration and method of sterilization. Secondly, we searched for randomized and non-randomized clinical studies that compared reversal of sterilization to IVF and evaluated them for pregnancy outcomes and cost effectiveness. We included 37 studies that investigated a total of 10 689 women. No randomized controlled trials were found. Most studies were retrospective cohort studies of a moderate quality. The pooled pregnancy rate after sterilization reversal was 42-69%, with heterogeneity seen from the different methods utilized. The reported ectopic pregnancy rate was 4-8%. The only prognostic factor affecting the

  14. Characterization and analysis of micro channels and sub-micron surface roughness of injection moulded microfluidic systems using optical metrology

    DEFF Research Database (Denmark)

    Tosello, Guido; Marinello, Francesco; Hansen, Hans Nørgaard

    2012-01-01

    Precision injection moulding of miniaturized products with micro features such as channels for microfluidic applications poses the greatest challenges in terms of tooling technology and process optimization. The injection moulding process window of polypropylene was validated using a metrological...... approach for the production of a microfluidic substrate. Dimensional accuracy of micro channels 48 µm wide and 110 µm deep, as well as quality surface topography replication (surface roughness from 30 nm to 360 nm) were investigated using non-contact measuring instruments such as an optical coordinate...... measuring machine and a white light interferometer respectively. The effect of the dimensional scale range on the micro/nano features replication was evaluated and it was found to be the dominant parameter if compared with the effect of the other process-related parameters investigated (melt and mould...

  15. Characterization and analysis of micro channels and sub-micron surface roughness of injection moulded microfluidic systems using optical metrology

    DEFF Research Database (Denmark)

    Tosello, Guido; Marinello, Francesco; Hansen, Hans Nørgaard

    2009-01-01

    Precision injection moulding of miniaturized products with micro features such as channels for microfluidic applications poses the greatest challenges in terms of tooling technology and process optimization. The injection moulding process window of polypropylene was validated using a metrological...... approach for the production of a microfluidic substrate. Dimensional accuracy of micro channels 48 µm wide and 110 µm deep, as well as quality surface topography replication (surface roughness from 30 nm to 360 nm) were investigated using non-contact measuring instruments such as an optical coordinate...... measuring machine and a white light interferometer respectively. The effect of the dimensional scale range on the micro/nano features replication was evaluated and it was found to be the dominant parameter if compared with the effect of the other process-related parameters investigated (melt and mould...

  16. Influence of biomass burning on mixing state of sub-micron aerosol particles in the North China Plain

    Science.gov (United States)

    Kecorius, Simonas; Ma, Nan; Teich, Monique; van Pinxteren, Dominik; Zhang, Shenglan; Gröβ, Johannes; Spindler, Gerald; Müller, Konrad; Iinuma, Yoshiteru; Hu, Min; Herrmann, Hartmut; Wiedensohler, Alfred

    2017-09-01

    Particulate emissions from crop residue burning decrease the air quality as well as influence aerosol radiative properties on a regional scale. The North China Plain (NCP) is known for the large scale biomass burning (BB) of field residues, which often results in heavy haze pollution episodes across the region. We have been able to capture a unique BB episode during the international CAREBeijing-NCP intensive field campaign in Wangdu in the NCP (38.6°N, 115.2°E) from June to July 2014. It was found that aerosol particles originating from this BB event showed a significantly different mixing state compared with clean and non-BB pollution episodes. BB originated particles showed a narrower probability density function (PDF) of shrink factor (SF). And the maximum was found at shrink factor of 0.6, which is higher than in other episodes. The non-volatile particle number fraction during the BB episode decreased to 3% and was the lowest measured value compared to all other predefined episodes. To evaluate the influence of particle mixing state on aerosol single scattering albedo (SSA), SSA at different RHs was simulated using the measured aerosol physical-chemical properties. The differences between the calculated SSA for biomass burning, clean and pollution episodes are significant, meaning that the variation of SSA in different pollution conditions needs to be considered in the evaluation of aerosol direct radiative effects in the NCP. And the calculated SSA was found to be quite sensitive on the mixing state of BC, especially at low-RH condition. The simulated SSA was also compared with the measured values. For all the three predefined episodes, the measured SSA are very close to the calculated ones with assumed mixing states of homogeneously internal and core-shell internal mixing, indicating that both of the conception models are appropriate for the calculation of ambient SSA in the NCP.

  17. 75 FR 66009 - Airworthiness Directives; Cessna Aircraft Company (Type Certificate Previously Held by Columbia...

    Science.gov (United States)

    2010-10-27

    ... Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing (Previously the Lancair... directive (AD): Cessna Aircraft Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing... Company (type certificate previously held by Columbia Aircraft Manufacturing (previously The Lancair...

  18. Scaling down

    Directory of Open Access Journals (Sweden)

    Ronald L Breiger

    2015-11-01

    Full Text Available While “scaling up” is a lively topic in network science and Big Data analysis today, my purpose in this essay is to articulate an alternative problem, that of “scaling down,” which I believe will also require increased attention in coming years. “Scaling down” is the problem of how macro-level features of Big Data affect, shape, and evoke lower-level features and processes. I identify four aspects of this problem: the extent to which findings from studies of Facebook and other Big-Data platforms apply to human behavior at the scale of church suppers and department politics where we spend much of our lives; the extent to which the mathematics of scaling might be consistent with behavioral principles, moving beyond a “universal” theory of networks to the study of variation within and between networks; and how a large social field, including its history and culture, shapes the typical representations, interactions, and strategies at local levels in a text or social network.

  19. In vivo dentate nucleus MRI relaxometry correlates with previous administration of Gadolinium-based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Tedeschi, Enrico; Canna, Antonietta; Cocozza, Sirio; Russo, Carmela; Angelini, Valentina; Brunetti, Arturo [University ' ' Federico II' ' , Neuroradiology, Department of Advanced Biomedical Sciences, Naples (Italy); Palma, Giuseppe; Quarantelli, Mario [National Research Council, Institute of Biostructure and Bioimaging, Naples (Italy); Borrelli, Pasquale; Salvatore, Marco [IRCCS SDN, Naples (Italy); Lanzillo, Roberta; Postiglione, Emanuela; Morra, Vincenzo Brescia [University ' ' Federico II' ' , Department of Neurosciences, Reproductive and Odontostomatological Sciences, Naples (Italy)

    2016-12-15

    To evaluate changes in T1 and T2* relaxometry of dentate nuclei (DN) with respect to the number of previous administrations of Gadolinium-based contrast agents (GBCA). In 74 relapsing-remitting multiple sclerosis (RR-MS) patients with variable disease duration (9.8±6.8 years) and severity (Expanded Disability Status Scale scores:3.1±0.9), the DN R1 (1/T1) and R2* (1/T2*) relaxation rates were measured using two unenhanced 3D Dual-Echo spoiled Gradient-Echo sequences with different flip angles. Correlations of the number of previous GBCA administrations with DN R1 and R2* relaxation rates were tested, including gender and age effect, in a multivariate regression analysis. The DN R1 (normalized by brainstem) significantly correlated with the number of GBCA administrations (p<0.001), maintaining the same significance even when including MS-related factors. Instead, the DN R2* values correlated only with age (p=0.003), and not with GBCA administrations (p=0.67). In a subgroup of 35 patients for whom the administered GBCA subtype was known, the effect of GBCA on DN R1 appeared mainly related to linear GBCA. In RR-MS patients, the number of previous GBCA administrations correlates with R1 relaxation rates of DN, while R2* values remain unaffected, suggesting that T1-shortening in these patients is related to the amount of Gadolinium given. (orig.)

  20. Natural attenuation is enhanced in previously contaminated and coniferous forest soils.

    Science.gov (United States)

    Kauppi, Sari; Romantschuk, Martin; Strömmer, Rauni; Sinkkonen, Aki

    2012-01-01

    Prevalence of organic pollutants or their natural analogs in soil is often assumed to lead to adaptation in the bacterial community, which results in enhanced bioremediation if the soil is later contaminated. In this study, the effects of soil type and contamination history on diesel oil degradation and bacterial adaptation were studied. Mesocosms of mineral and organic forest soil (humus) were artificially treated with diesel oil, and oil hydrocarbon concentrations (GC-FID), bacterial community composition (denaturing gradient gel electrophoresis, DGGE), and oil hydrocarbon degraders (DGGE + sequencing of 16S rRNA genes) were monitored for 20 weeks at 16°C. Degradation was advanced in previously contaminated soils as compared with pristine soils and in coniferous organic forest soil as compared with mineral soil. Contamination affected bacterial community composition especially in the pristine mineral soil, where diesel addition increased the number of strong bands in the DGGE gel. Sequencing of cloned 16S rRNA gene fragments and DGGE bands showed that potential oil-degrading bacteria were found in mineral and organic soils and in both pristine and previously contaminated mesocosms. Fast oil degradation was not associated with the presence of any particular bacterial strain in soil. We demonstrate at the mesocosm scale that previously contaminated and coniferous organic soils are superior environments for fast oil degradation as compared with pristine and mineral soil environments. These results may be utilized in preventing soil pollution and planning soil remediation.

  1. Efficiency of five chemical protective clothing materials against nano and submicron aerosols when submitted to mechanical deformations.

    Science.gov (United States)

    Ben Salah, Mehdi; Hallé, Stéphane; Tuduri, Ludovic

    2016-01-01

    Due to their potential toxicity, the use of nanoparticles in the workplace is a growing concern. Some studies indicate that nanoparticles can penetrate the skin and lead to adverse health effects. Since chemical protective clothing is the last barrier to protect the skin, this study aims to better understand nanoparticle penetration behaviour in dermal protective clothing under mechanical deformation. For this purpose, five of the most common types of fabrics used in protective clothing, one woven and four nonwoven, were chosen and submitted to different simulated exposure conditions. They were tested against polydispersed NaCl aerosols having an electrical-mobility diameter between 14 and 400 nm. A bench-scale exposure setup and a sampling protocol was developed to measure the level of penetration of the aerosols through the material samples of disposable coveralls and lab coat, while subjecting them to mechanical deformations to simulate the conditions of usage in the workplace. Particle size distribution of the aerosol was determined upstream and downstream using a scanning mobility particle sizer (SMPS). The measured efficiencies demonstrated that the performances of nonwoven materials were similar. Three nonwovens had efficiencies above 99%, while the woven fabric was by far, the least effective. Moreover, the results established that mechanical deformations, as simulated for this study, did not have a significant effect on the fabrics' efficiencies.

  2. Scaling Rules!

    Science.gov (United States)

    Malkinson, Dan; Wittenberg, Lea

    2015-04-01

    Scaling is a fundamental issue in any spatially or temporally hierarchical system. Defining domains and identifying the boundaries of the hierarchical levels may be a challenging task. Hierarchical systems may be broadly classified to two categories: compartmental and continuous ones. Examples of compartmental systems include: governments, companies, computerized networks, biological taxonomy and others. In such systems the compartments, and hence the various levels and their constituents are easily delineated. In contrast, in continuous systems, such as geomorphological, ecological or climatological ones, detecting the boundaries of the various levels may be difficult. We propose that in continuous hierarchical systems a transition from one functional scale to another is associated with increased system variance. Crossing from a domain of one scale to the domain of another is associated with a transition or substitution of the dominant drivers operating in the system. Accordingly we suggest that crossing this boundary is characterized by increased variance, or a "variance leap", which stabilizes, until crossing to the next domain or hierarchy level. To assess this we compiled sediment yield data from studies conducted at various spatial scales and from different environments. The studies were partitioned to ones conducted in undisturbed environments, and those conducted in disturbed environments, specifically by wildfires. The studies were conducted in plots as small as 1 m2, and watersheds larger than 555000 ha. Regressing sediment yield against plot size, and incrementally calculating the variance in the systems, enabled us to detect domains where variance values were exceedingly high. We propose that at these domains scale-crossing occurs, and the systems transition from one hierarchical level to another. Moreover, the degree of the "variance leaps" characterizes the degree of connectivity among the scales.

  3. Consideration of the respiratory cycle asymmetry in the numerical modeling of the submicron particles deposition in the human nasal cavity

    Science.gov (United States)

    Ganimedov, V. L.; Muchnaya, M. I.

    2017-10-01

    A detailed study of the behavior of the U-shaped curve was conducted, which described deposition efficiency of inhaled particles in human nasal cavity. The particles in the range from 1 nm to 20 µm are considered. Calculations of air flow and particles deposition were carried out for symmetrical (idealized) and asymmetrical (real) breathing cycles at the same volume of inhaled air, which corresponded to calm breathing. The calculations were performed on the base of the mathematical model of the nasal cavity of healthy person using software package ANSYS (FLUENT 12). The comparison of the results was made between these calculations, and also with the results obtained at quasi-stationary statement of the problem for several values of flow rate. The comparison of the results of quasi-stationary calculations with available calculated and experimental data (in vivo i in vitro) was fulfilled previously. Good agreement of the results was obtained. It is shown that the real distribution of deposition efficiency as a function of the particle size can be obtained via a certain combination of the results of quasi-stationary calculations, without the use of laborious and time-consuming non-stationary calculation.

  4. The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles.

    Science.gov (United States)

    Wang, Xiaofei; Deane, Grant B; Moore, Kathryn A; Ryder, Olivia S; Stokes, M Dale; Beall, Charlotte M; Collins, Douglas B; Santander, Mitchell V; Burrows, Susannah M; Sultana, Camille M; Prather, Kimberly A

    2017-07-03

    The oceans represent a significant global source of atmospheric aerosols. Sea spray aerosol (SSA) particles comprise sea salts and organic species in varying proportions. In addition to size, the overall composition of SSA particles determines how effectively they can form cloud droplets and ice crystals. Thus, understanding the factors controlling SSA composition is critical to predicting aerosol impacts on clouds and climate. It is often assumed that submicrometer SSAs are mainly formed by film drops produced from bursting bubble-cap films, which become enriched with hydrophobic organic species contained within the sea surface microlayer. In contrast, jet drops formed from the base of bursting bubbles are postulated to mainly produce larger supermicrometer particles from bulk seawater, which comprises largely salts and water-soluble organic species. However, here we demonstrate that jet drops produce up to 43% of total submicrometer SSA number concentrations, and that the fraction of SSA produced by jet drops can be modulated by marine biological activity. We show that the chemical composition, organic volume fraction, and ice nucleating ability of submicrometer particles from jet drops differ from those formed from film drops. Thus, the chemical composition of a substantial fraction of submicrometer particles will not be controlled by the composition of the sea surface microlayer, a major assumption in previous studies. This finding has significant ramifications for understanding the factors controlling the mixing state of submicrometer SSA particles and must be taken into consideration when predicting SSA impacts on clouds and climate.

  5. The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles

    Science.gov (United States)

    Wang, Xiaofei; Deane, Grant B.; Moore, Kathryn A.; Ryder, Olivia S.; Stokes, M. Dale; Beall, Charlotte M.; Collins, Douglas B.; Santander, Mitchell V.; Burrows, Susannah M.; Sultana, Camille M.; Prather, Kimberly A.

    2017-07-01

    The oceans represent a significant global source of atmospheric aerosols. Sea spray aerosol (SSA) particles comprise sea salts and organic species in varying proportions. In addition to size, the overall composition of SSA particles determines how effectively they can form cloud droplets and ice crystals. Thus, understanding the factors controlling SSA composition is critical to predicting aerosol impacts on clouds and climate. It is often assumed that submicrometer SSAs are mainly formed by film drops produced from bursting bubble-cap films, which become enriched with hydrophobic organic species contained within the sea surface microlayer. In contrast, jet drops formed from the base of bursting bubbles are postulated to mainly produce larger supermicrometer particles from bulk seawater, which comprises largely salts and water-soluble organic species. However, here we demonstrate that jet drops produce up to 43% of total submicrometer SSA number concentrations, and that the fraction of SSA produced by jet drops can be modulated by marine biological activity. We show that the chemical composition, organic volume fraction, and ice nucleating ability of submicrometer particles from jet drops differ from those formed from film drops. Thus, the chemical composition of a substantial fraction of submicrometer particles will not be controlled by the composition of the sea surface microlayer, a major assumption in previous studies. This finding has significant ramifications for understanding the factors controlling the mixing state of submicrometer SSA particles and must be taken into consideration when predicting SSA impacts on clouds and climate.

  6. Highly porous acrylonitrile-based submicron particles for UO2(2+) absorption in an immunosensor assay.

    Science.gov (United States)

    Sahiner, Nurettin; Yu, Haini; Tan, Grace; He, Jibao; John, Vijay T; Blake, Diane A

    2012-01-01

    Our laboratory has previously reported an antibody-based assay for hexavalent uranium (UO(2)(2+)) that could be used on-site to rapidly assess uranium contamination in environmental water samples (Melton, S. J.; et al. Environ. Sci. Technol. 2009, 43, 6703-6709). To extend the utility of this assay to less-characterized sites of uranium contamination, we required a uranium-specific adsorbent that would rapidly remove the uranium from groundwater samples, while leaving the concentrations of other ions in the groundwater relatively unaltered. This study describes the development of hydrogel particles containing amidoxime groups that can rapidly and selectively facilitate the uptake of uranyl ions. A miniemulsion polymerization technique using SDS micelles was employed for the preparation of the hydrogel as linked submicrometer particles. In polymerization, acrylonitrile was used as the initial monomer, ethylene glycol dimethacrylate as the crosslinker and 2-hydroxymethacrylate, 1-vinyl-2-pyrrolidone, acrylic acid, or methacrylic acid were added as co-monomers after the initial seed polymerization of acrylonitrle. The particles were characterized by transmission electron spectroscopy, scanning electron microscopy (SEM) and cryo-SEM. The amidoximated particles were superior to a commercially available resin in their ability to rapidly remove dissolved UO(2)(2+) from spiked groundwater samples. © 2011 American Chemical Society

  7. Developing a News Media Literacy Scale

    Science.gov (United States)

    Ashley, Seth; Maksl, Adam; Craft, Stephanie

    2013-01-01

    Using a framework previously applied to other areas of media literacy, this study developed and assessed a measurement scale focused specifically on critical news media literacy. Our scale appears to successfully measure news media literacy as we have conceptualized it based on previous research, demonstrated through assessments of content,…

  8. Source apportionment of submicron organic aerosol collected from Atlanta, Georgia, during 2014-2015 using the aerosol chemical speciation monitor (ACSM)

    Science.gov (United States)

    Rattanavaraha, Weruka; Canagaratna, Manjula R.; Budisulistiorini, Sri Hapsari; Croteau, Philip L.; Baumann, Karsten; Canonaco, Francesco; Prevot, Andre S. H.; Edgerton, Eric S.; Zhang, Zhenfa; Jayne, John T.; Worsnop, Douglas R.; Gold, Avram; Shaw, Stephanie L.; Surratt, Jason D.

    2017-10-01

    The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) was redeployed at the Jefferson Street (JST) site in downtown Atlanta, Georgia (GA) for 1 year (March 20, 2014-February 08, 2015) to chemically characterize non-refractory submicron particulate matter (NR-PM1) in near real-time and to assess whether organic aerosol (OA) types and amounts change from year-to-year. Submicron organic aerosol (OA) mass spectra were analyzed by season using multilinear engine (ME-2) to apportion OA subtypes to potential sources and chemical processes. A suite of real-time collocated measurements from the Southeastern Aerosol Research and Characterization (SEARCH) network was compared with ME-2 factor solutions to aid in the interpretation of OA subtypes during each season. OA tracers measured from high-volume filter samples using gas chromatography interfaced with electron ionization-mass spectrometry (GC/EI-MS) also aided in identifying OA sources. The initial application of ME-2 to the yearlong ACSM dataset revealed that OA source apportionment by season was required to better resolve sporadic OA types. Spring and fall OA mass spectral datasets were separated into finer periods to capture potential OA sources resulting from non-homogeneous emissions during transitioning periods. NR-PM1 was highest in summer (16.7 ± 8.4 μg m-3) and lowest in winter (8.0 ± 5.7 μg m-3), consistent with prior studies. OA dominated NR-PM1 mass (56-74% on average) in all seasons. Hydrocarbon-like OA (HOA) from primary emissions was observed in all seasons, averaging 5-22% of total OA mass. Strong correlations of HOA with carbon monoxide (CO) (R = 0.71-0.88) and oxides of nitrogen (NOx) (R = 0.55-0.79) indicated that vehicular traffic was the likely source. Biomass burning OA (BBOA) was observed in all seasons, with lower contributions (2%) in summer and higher in colder seasons (averaging 8-20% of total OA mass). BBOA correlated strongly with levoglucosan (R = 0.78-0.95) during colder seasons

  9. Submicron sized ultra-high molecular weight polyethylene wear particle analysis from revised SB Charité III total disc replacements.

    Science.gov (United States)

    Punt, Ilona; Baxter, Ryan; van Ooij, André; Willems, Paul; van Rhijn, Lodewijk; Kurtz, Steven; Steinbeck, Marla

    2011-09-01

    Submicron sized particles are frequently observed in retrieved total hip and knee periprosthetic tissues and appear to be critical in the activation of the phagocytic inflammatory response. In this paper the concentration, size and shape of ultra-high molecular weight polyethylene (UHMWPE) wear particles between 0.05 and 2.00μm were determined after isolation from periprosthetic tissues from retrieved lumbar SB Charité III total disc replacements (TDR) using scanning electron microscopy (SEM). For comparison, UHMWPE wear particles were isolated from γ-radiation-air sterilized total hip arthroplasty (THA) revision tissues. The mean concentration of UHMWPE particles in TDR tissues was 1.6×10(9)g(-1)tissue (range 1.3-2.0), which was significantly lower than the concentration of 2.3×10(9)g(-1) THA revision tissue (range 1.8-3.2) (P=0.03). The mean particle size (equivalent circular diameter: TDR, 0.46μm; THA 0.53μm, P=0.60) and mean shape were comparable between TDR and THA (aspect ratio: TDR, 1.89; THA, 1.99, P=0.35; roundness: TDR, 0.58; THA, 0.56, P=0.35). However, the TDR particles tended to be smaller and more round. Although no correlations were found between visible damage to the UHMWPE core and the concentration or shape of the UHMWPE particles, a positive correlation was found between increasing particle size and increasing rim penetration of the TDR core (P=0.04). The presence of UHMWPE particles of similar size and shape in TDR tissue, albeit lower in concentration, might explain why, unlike THA, pain rather than osteolysis is the major reason for revision surgery. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. Osteoblast viability on hydroxyapatite with well-adjusted submicron and micron surface roughness as monitored by the proliferation reagent WST-1.

    Science.gov (United States)

    Holthaus, Marzellus Große; Treccani, Laura; Rezwan, Kurosch

    2013-03-01

    The impact of the cell surface roughness on titanium alloys used for biomedical implants has been extensively studied, whereas the dependency of human osteoblast viability on hydroxyapatite (HA) submicron and micron surface roughness has hitherto not yet been investigated in detail. Therefore, we investigate in this study the effect of HA substrates with different well-adjusted surface roughness on human osteoblast proliferation using the standard colorimetric reagent WST-1. By grinding, we obtained HA surfaces with six levels of well-defined surface roughness ranging from Sa = 3.36 µm down to 0.13 µm, resulting in hydrophilic contact angles from 11° to 27°. Energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray fluorescence measurements confirmed that neither grinding paper residues nor changes of the crystal structure were introduced to the HA substrates by the grinding process. By applying this simple surface treatment, we were able to isolate other effects from surface chemistry, crystal structure, and relative density. The changes of the osteoblast proliferation (WST-1 assay) on these different roughened HA surfaces after 7 days were found to be insignificant (p > 0.05), evaluated by one-way analysis of variance and Tuckey's Multiple Comparison Method. The results of this study show that all roughened HA surfaces, regardless of the microtopography, are biocompatible and allow osteoblast attachment, proliferation, and collagen type I production. The comparison with surface roughness used for standard Ti-based implants yielded that for HA no finishing process is necessary to ensure a sound human osteoblast cell proliferation in vitro.

  11. Airborne measurement of submicron aerosol number concentration and CCN activity in and around the Korean Peninsula and their comparison to ground measurement in Seoul

    Science.gov (United States)

    Park, M.; Kim, N.; Yum, S. S.

    2016-12-01

    Aerosols exert impact not only on human health and visibility but also on climate change directly by scattering or absorbing solar radiation and indirectly by acting as cloud condensation nuclei (CCN) and thus altering cloud radiative and microphysical properties. Aerosol indirect effects on climate has been known to have large uncertainty because of insufficient measurement data on aerosol and CCN activity distribution. Submicron aerosol number concentration (NCN, TSI CPC) and CCN number concentration (NCCN, DMT CCNC) were measured on board the NASA DC-8 research aircraft and at a ground site at Olympic Park in Seoul from May 2nd to June 10th, 2016. CCNC on the airborne platform was operated with the fixed internal supersaturation of 0.6% and CCNC at the ground site was operated with the five different supersaturations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). The NASA DC-8 conducted 20 research flights (about 150 hours) in and around the Korean Peninsula and the ground measurement at Olympic Park was continuously made during the measurement period. Both airborne and ground measurements showed spatially and temporally varied aerosol number concentration and CCN activity. Aerosol number concentration in the boundary layer measured on airborne platform was highly affected by pollution sources on the ground. The average diurnal distribution of ground aerosol number concentration showed distinct peaks are located at about 0800, 1500, and 2000. The middle peak indicates that new particle formation events frequently occurred during the measurement period. CCN activation ratio at 0.6% supersaturation (NCCN/NCN) of the airborne measurement ranged from 0.1 to 0.9, indicating that aerosol properties in and around the Korean Peninsula varied so much (e. g. size, hygroscopicity). Comprehensive analysis results will be shown at the conference.

  12. Facile Synthesis of Novel Heterostructure Based on SnO2 Nanorods Grown on Submicron Ni Walnut with Tunable Electromagnetic Wave Absorption Capabilities.

    Science.gov (United States)

    Zhao, Biao; Fan, Bingbing; Shao, Gang; Zhao, Wanyu; Zhang, Rui

    2015-08-26

    In this work, the magnetic-dielectric core-shell heterostructure composites with the core of Ni submicron spheres and the shell of SnO2 nanorods were prepared by a facile two-step route. The crystal structure and morphology were investigated by X-ray diffraction analysis, transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM). FESEM and TEM measurements present that SnO2 nanorods were perpendicularly grown on the surfaces of Ni spheres and the density of the SnO2 nanorods could be tuned by simply varying the addition amount of Sn(2+) in this process. The morphology of Ni/SnO2 composites were also determined by the concentration of hydrochloric acid and a plausible formation mechanism of SnO2 nanorods-coated Ni spheres was proposed based on hydrochloric acid concentration dependent experiments. Ni/SnO2 composites exhibit better thermal stability than pristine Ni spheres based on thermalgravimetric analysis (TGA). The measurement on the electromagnetic (EM) parameters indicates that SnO2 nanorods can improve the impedance matching condition, which is beneficial for the improvement of electromagnetic wave absorption. When the coverage density of SnO2 nanorod is in an optimum state (diameter of 10 nm and length of about 40-50 nm), the optimal reflection loss (RL) of electromagnetic wave is -45.0 dB at 13.9 GHz and the effective bandwidth (RL below -10 dB) could reach to 3.8 GHz (12.3-16.1 GHz) with the absorber thickness of only 1.8 mm. By changing the loading density of SnO2 nanorods, the best microwave absorption state could be tuned at 1-18 GHz band. These results pave an efficient way for designing new types of high-performance electromagnetic wave absorbing materials.

  13. Particle formation and plasma radiative losses during laser ablation suitability of the Sedov-Taylor scaling.

    Science.gov (United States)

    Palanco, Santiago; Marino, Salvatore; Gabás, Mercedes; Bijani, Shanti; Ayala, Luis; Ramos-Barrado, José R

    2014-06-30

    Deviations of the Sedov-Taylor scaling at three different laser ablation regimes (500 mJ in a 0.8 mm spot, 50 mJ in a 0.8 mm spot and 500 mJ in a 2.5 mm spot) were investigated using Schlieren photography in combination with optical scattering and optical emission spectrometry, among others. For each case, the time evolution of the shock front was related to the formation, expansion and properties of the plasma. Both, the time scale of the different radiative processes and that observed for vapor condensation into nanoparticles and sub-micron particles are compatible with the divergences found between the model and experimental data.

  14. Children and adolescents previously treated with glucocorticoids display lower verbal intellectual abilities

    DEFF Research Database (Denmark)

    Holm, Sara Krøis; Vestergaard, Martin; Madsen, Kathrine Skak

    2015-01-01

    /kg (range 21-723) and the mean time that had elapsed since treatment was three-and-a-half (standard deviation 2.2) years. Intellectual abilities were assessed with the Wechsler Intelligence Scale for Children and memory performance and behavioural problems with a pattern recognition memory task......AIM: Perinatal exposure to glucocorticoids has been associated with adverse cerebral effects, but little is known about their effect on cognitive development and exposure later in childhood. This study examined intellectual abilities, memory and behavioural problems in children previously treated...... and the Child Behaviour Check List. RESULTS: There were no significant differences between the groups in pattern recognition memory, perceptual organisation index or behavioural problems, but patients had a significantly lower verbal comprehension index and this difference was present in both disease groups...

  15. Nuclear scales

    Energy Technology Data Exchange (ETDEWEB)

    Friar, J.L.

    1998-12-01

    Nuclear scales are discussed from the nuclear physics viewpoint. The conventional nuclear potential is characterized as a black box that interpolates nucleon-nucleon (NN) data, while being constrained by the best possible theoretical input. The latter consists of the longer-range parts of the NN force (e.g., OPEP, TPEP, the {pi}-{gamma} force), which can be calculated using chiral perturbation theory and gauged using modern phase-shift analyses. The shorter-range parts of the force are effectively parameterized by moments of the interaction that are independent of the details of the force model, in analogy to chiral perturbation theory. Results of GFMC calculations in light nuclei are interpreted in terms of fundamental scales, which are in good agreement with expectations from chiral effective field theories. Problems with spin-orbit-type observables are noted.

  16. Comparison of Reduced Displacement Potentials from Spe Free Field Measurements: SPE-4PRIME Versus Previous Events

    Science.gov (United States)

    Patton, H. J.; Rougier, E.

    2015-12-01

    Since 2010, the U. S. Department of Energy has funded a series of chemical tests at the National Nuclear Security Site (NNSS) in Climax Stock granite as part of the Source Physics Experiment (SPE) with the aim of gaining a better understanding of the generation and propagation of seismic energy from underground explosions in hard rock media. To date, four tests have been conducted in the same borehole with yields of 100, 1000, 900 and 100 kg at different depths of burials. The nominal scaled depths of burial are 938, 363, 376 and 1556 m/kt1/3 compared to standard containment practices of ~120 m/kt1/3. A quite dense array of free field accelerometers were installed around the borehole, both on and off shot depth. Acceleration data were corrected for shock-generated baseline-shifts, and free field ground velocity waveforms were obtained. This work concentrates on the qualitative analysis of the reduced displacement potentials and the explosion source spectra for the last shot of the series (SPE-4Prime) and the comparison of the obtained results against the previous events. Finally, the results obtained from the experimental data are compared to the Mueller-Murphy empirical explosion model both using the Heard and Ackerman and Denny and Johnson cavity radius scaling laws.

  17. Biased ART: a neural architecture that shifts attention toward previously disregarded features following an incorrect prediction.

    Science.gov (United States)

    Carpenter, Gail A; Gaddam, Sai Chaitanya

    2010-04-01

    Memories in Adaptive Resonance Theory (ART) networks are based on matched patterns that focus attention on those portions of bottom-up inputs that match active top-down expectations. While this learning strategy has proved successful for both brain models and applications, computational examples show that attention to early critical features may later distort memory representations during online fast learning. For supervised learning, biased ARTMAP (bARTMAP) solves the problem of over-emphasis on early critical features by directing attention away from previously attended features after the system makes a predictive error. Small-scale, hand-computed analog and binary examples illustrate key model dynamics. Two-dimensional simulation examples demonstrate the evolution of bARTMAP memories as they are learned online. Benchmark simulations show that featural biasing also improves performance on large-scale examples. One example, which predicts movie genres and is based, in part, on the Netflix Prize database, was developed for this project. Both first principles and consistent performance improvements on all simulation studies suggest that featural biasing should be incorporated by default in all ARTMAP systems. Benchmark datasets and bARTMAP code are available from the CNS Technology Lab Website: http://techlab.bu.edu/bART/. Copyright 2009 Elsevier Ltd. All rights reserved.

  18. Prognostic value of a previous medical or surgical admission in outpatients with symptomatic pulmonary embolism.

    Science.gov (United States)

    Ruiz-Artacho, P; Rodríguez-López, I; Pérez Peña, C; González Del Castillo, J; Calvo, E; Martín-Sánchez, F J

    2016-03-01

    To determine whether an earlier medical (MA) or surgical (SA) admission in the previous three months is a factor associated with mortality at 30 days in outpatients with acute symptomatic pulmonary embolism. Observational, retrospective cohort study on adult patients diagnosed with acute symptomatic pulmonary embolism in a tertiary hospital over a period of 6 years. The study included 870 patients with a mean age of 72.7 years: 10.6% (92) had a prior MA, 4.9% (43) had a SA and 12.9% (112) died within the first 30 days. The MA group showed a higher frequency of simplified Pulmonary Embolism Severity Index (PESI) of high risk (≥1) (MA 90.2% vs SA 65.1% vs no prior admission 67.0%; p<0.001) and mortality at 30 days (MA 20.7% vs SA 7.0% vs no prior admission 12.9%; p=0.038). The logistic regression analysis demonstrated that a simplified PESI≥1 was the only independent risk factor for mortality at 30 days. The severity of the acute episode, as assessed by the simplified PESI scale, is independently associated with mortality at 30 days in outpatients with acute symptomatic pulmonary embolism. An earlier MA in the previous 3 months usually involves greater severity in the acute episode. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  19. Previous medical history of diseases in children with attention deficit hyperactivity disorder and their parents

    Directory of Open Access Journals (Sweden)

    Ayyoub Malek

    2014-02-01

    Full Text Available Introduction: The etiology of Attention deficit hyperactivity disorder (ADHD is complex and most likely includes genetic and environmental factors. This study was conducted to evaluatethe role of previous medical history of diseases in ADHD children and their parents during theearlier years of the ADHD children's lives. Methods: In this case-control study, 164 ADHD children attending to Child and AdolescentPsychiatric Clinics of Tabriz University of Medical Sciences, Iran, compared with 166 normal children selected in a random-cluster method from primary and guidance schools. ADHDrating scale (Parents version and clinical interview based on schedule for Schedule forAffective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version(K-SADS were used to diagnose ADHD cases and to select the control group. Two groupswere compared for the existence of previous medical history of diseases in children andparents. Fisher's exact test and logistic regression model were used for data analysis. Results: The frequency of maternal history of medical disorders (28.7% vs. 12.0%; P = 0.001was significantly higher in children with ADHD compared with the control group. The frequency of jaundice, dysentery, epilepsy, asthma, allergy, and head trauma in the medicalhistory of children were not significantly differed between the two groups. Conclusion: According to this preliminary study, it may be concluded that the maternal historyof medical disorders is one of contributing risk factors for ADHD.

  20. Fullerene-Containing Electrically Conducting Electron Beam Resist for Ultrahigh Integration of Nanometer Lateral-Scale Organic Electronic Devices.

    Science.gov (United States)

    Nakajima, Anri; Tabei, Tetsuo; Yasukawa, Tatsuya

    2017-06-27

    An outstanding issue with organic devices is the difficulty of simultaneously controlling the lateral size and position of structures at submicron or nanometer scales. In this study, nanocomposite electron beam (EB) organic resists are proved to be excellent candidates for electrically conductive and/or memory component materials for submicron or nanometer lateral-scale organic electronic devices. The memory and the resist patterning characteristics are investigated for a positive electron beam resist of ZEP520a containing [6,6]-phenyl-C61 butyric acid methyl ester (PCBM). Regarding the memory characteristics, good programming and excellent retention characteristics are obtained for electrons. The carrier transfer and retention mechanisms are also investigated. Regarding the resist patterning characteristics, it is found that line patterns (square patterns) of ZEP520a containing PCBM can be made with widths (side lengths) of less than 200 nm by using an extremely simple process with only EB exposures and developments. The distribution of PCBM molecules or their aggregations is also clarified in ZEP520a containing PCBM. The results of this study open the door to the simple fabrication of highly integrated flexible memories and electrical wires as well as of single-electron or quantum devices, including quantum information devices and sensitive biosensors for multiplexed and simultaneous diagnoses.

  1. Protein Supplement Usage Among Male University Students: Comparisons Between Current and Previous Users.

    Science.gov (United States)

    Sung, Youngmo; Choi, Jinkyung

    2018-02-01

    Interest in specialized dietary supplements is leading market growth, and protein supplements are popular for increasing muscle mass among young males. Therefore, this study investigated the attitudes toward and satisfaction with protein supplements to identify detailed consumer behaviors related to the consumption of protein supplements. The study sample includes male university students in their 20s in South Korea. In total, 223 responses were entered for analysis. Questions related to attitudes, satisfaction, and future behavioral intentions were asked using 5-point Likert scales. The responses were divided into two groups, current and previous users, to identify significant differences in terms of attitudes, satisfaction, and future behavioral intentions. A descriptive analysis, analysis of variance (ANOVA), and multiple regression were run. The majority of respondents prefer the powdered form of supplements in bulk with a price range between 30,000 won and 60,000 won. Online shopping was preferred, while word of mouth and friends/family were considered credible information sources. The most common side effects experienced were problems with digestion and hives, although more than 78% did not experience side effects. In comparison between current and previous users in terms of attitudes and satisfaction, the following areas showed significances. Regarding attitudes, the importance of brand, preference for products from overseas, the search for nutritional facts, and reading carefully all product information were significant, while regarding satisfaction, price, effectiveness, and ease of consumption were significant. All significances showed that current users had more positive attitudes and greater satisfaction. Overall, consumers' satisfaction regarding ease of consumption influenced future behavioral intentions. The market for protein supplements has been growing, so measuring consumers' attitudes and satisfaction would help attract potential consumers. In

  2. Female Sexual Dysfunction in the Late Postpartum Period Among Women with Previous Gestational Diabetes Mellitus.

    Science.gov (United States)

    Sargin, Mehmet Akif; Yassa, Murat; Taymur, Bilge Dogan; Taymur, Bulent; Akca, Gizem; Tug, Niyazi

    2017-04-01

    To compare the status of female sexual dysfunction (FSD) between women with a history of previous gestational diabetes mellitus (GDM) and those with follow-up of a healthy pregnancy, using the female sexual function index (FSFI) questionnaire. Cross-sectional study. Department of Obstetrics and Gynecology, Fatih Sultan Mehmet Training and Research Hospital, Istanbul, Turkey, from September to December 2015. Healthy sexually active adult parous females were included. Participants were asked to complete the validated Turkish versions of the FSFI and Hospital Anxiety and Depression Scale (HADS) questionnaires. Student's t-test was used for two-group comparisons of normally distributed variables and quantitative data. Mann-Whitney U-test was used for two-group comparisons of non-normally distributed variables. Pearson's chi-squared test, the Fisher-FreemanHalton test, Fisher's exact test, and Yates' continuity correction test were used for comparison of qualitative data. The mean FSFI scores of the 179 participants was 23.50 ±3.94. FSFI scores and scores of desire, arousal, lubrication, orgasm, satisfaction, and pain were not statistically significantly different (p>0.05), according to a history of GDM and types of FSD (none, mild, severe). HADS scores and anxiety and depression types did not statistically significantly differ according to the history of GDM (p>0.05). An association could not be found in FSFI scores between participants with both the history of previous GDM and with healthy pregnancy; subclinical sexual dysfunction may be observed in the late postpartum period among women with a history of previous GDM. This may adversely affect their sexual health.

  3. Neutron and proton irradiation for latch-up suppression in a radiation-tolerant commercial submicron CMOS process; Suppression du latchup sur une technologie commerciale CMOS submicronique tolerante aux radiations par irradiation de neutrons et de protons

    Energy Technology Data Exchange (ETDEWEB)

    Lacoe, R.C.; Moss, S.C.; Mayer, D.C.; Osborn, J.V.; Janousek, B.K.; Lalumondiere, S.D.; Brown, S. [Electronics Technology Center, The Aerospace Corp., Los Angeles, CA (United States)

    1999-07-01

    We have measured the effects of neutron and proton irradiation on test structures fabricated at a radiation-tolerant commercial submicron CMOS foundry. The effects of neutron and proton irradiation were to monotonically decrease the parasitic bipolar transistor gains with increasing fluence. For the neutron irradiated test structures the latch-up threshold increases monotonically with increasing fluence, while for the proton irradiated test structures, the latch-up threshold initially decreased before increasing with increasing fluence. These results will be discussed in terms of the effects of random and localized damage on minority carrier lifetime and the implications for mitigating latch-up in commercial parts for space application. (authors)

  4. Submicron Structures and Various Technology

    Science.gov (United States)

    1990-06-01

    develop- The fiber ring is or’e realization of a fiber ring ment of (1) analytical and computer tools for gyro utilizing the Sagnac effect. Unfortu- the...because the noise describing optical pulse interactions and for that is in phase with the Sagnac signal is not experimentally verifying their...of basic quantum physics, for metrology , as rotation sensors, and, perhaps, ultimately as devices to make ultra-small structures using atom holograms

  5. Submicron patterns obtained by thermal-induced reconstruction of self-assembled monolayer of Ag nanoparticles and their application in SERS

    Science.gov (United States)

    Ruan, Weidong; Zhou, Tieli; Cui, Yinqiu; Dong, Yujie; Liu, Zhuo; Dong, Fengxia; Wang, Haiyang; Luan, Xintong; Wang, Xu; Song, Wei; Zhao, Bing

    2014-08-01

    The layer-by-layer (LbL) self-assembly technique was employed for the deposition of poly(diallyldimethylammonium chloride) (PDDA) and triangular Ag nanoplates on glass substrates. A thermal-induced reconstruction of these polyelectrolyte-linked nanoparticle (NP) films was presented. Before the reconstruction, triangular Ag nanoplates were distributed uniformly on the surface with an average interval of 50 ± 15 nm. After the reconstruction, the triangular Ag nanoplates accumulated into discrete stacks with an average interval of 90 ± 25 nm. The temperature-dependent experiments were done and the optimal temperature for the formation of the reconstructed patterns was 120 °C. The possible mechanism of the NP movement and stacking was analyzed. Under the experimental conditions, a hydrophobic environment was formed because of the vacuum and heating. As a result the polyelectrolyte-linked Ag NPs preferred to congregate due to the lowered surface energy. Finally the submicron patterns were formed. The ultraviolet-visible (UV-vis) absorption and surface-enhanced Raman scattering (SERS) properties of the films before and after the reconstruction was investigated. The reconstructed films with submicron patterns had better SERS enhancement ability, which was 1300 times to the original films. The reconstruction method of the monolayer films showed great potential in the surface design and related applications. AFM images were obtained to clarify the three dimensional structures of the reconstructed films obtained at 120 °C. As shown in Fig. 2, the Ag NP stacks had an average diameter of 1.0 ± 0.2 μm and an average height of 170 ± 30 nm. The diameter and height of the stacks were shaped by the aggregates of tens of triangular Ag nanoplates. The AFM cross-sectional contour showed the clear intervals of the stacks, which was corresponding to the SEM characterization.XRD patterns of the polyelectrolyte-linked NP films before and after thermal post-treatment are showed in

  6. Tailored synthesis of monodispersed nano/submicron porous silicon oxycarbide (SiOC) spheres with improved Li-storage performance as an anode material for Li-ion batteries

    Science.gov (United States)

    Shi, Huimin; Yuan, Anbao; Xu, Jiaqiang

    2017-10-01

    A spherical silicon oxycarbide (SiOC) material (monodispersed nano/submicron porous SiOC spheres) is successfully synthesized via a specially designed synthetic strategy involving pyrolysis of phenyltriethoxysilane derived pre-ceramic polymer spheres at 900 °C. In order to prevent sintering of the pre-ceramic polymer spheres upon heating, a given amount of hollow porous SiO2 nanobelts which are separately prepared from tetraethyl orthosilicate with CuO nanobelts as templates are introduced into the pre-ceramic polymer spheres before pyrolysis. This material is investigated as an anode for lithium-ion batteries in comparison with the large-size bulk SiOC material synthesized under the similar conditions but without hollow SiO2 nanobelts. The maximum reversible specific capacity of ca. 900 mAh g-1 is delivered at the current density of 100 mA g-1 and ca. 98% of the initial capacity is remained after 100 cycles at 100 mA g-1 for the SiOC spheres material, which are much superior to the bulk SiOC material. The improved lithium storage performance in terms of specific capacity and cyclability is attributed to its particular morphology of monodisperse nano/submicron porous spheres as well as its modified composition and microstructure. This SiOC material has higher Li-storage activity and better stability against volume expansion during repeated lithiation and delithiation cycling.

  7. Exposure to submicron particles (PM1.0) from diesel exhaust and pollen allergens of human lung epithelial cells induces morphological changes of mitochondria tonifilaments and rough endoplasmic reticulum.

    Science.gov (United States)

    Mazzarella, Gennaro; Lucariello, Angela; Bianco, Andrea; Calabrese, Cecilia; Thanassoulas, Theodoros; Savarese, Leonilde; Fiumarella, Angelamaria; Esposito, Vincenzo; DE Luca, Antonio

    2014-01-01

    In recent literature, little has been said regarding the morphological changes that occur in lung cells after treatment with particles and nanoparticles. Using an in vitro model of type-II lung epithelium (A549), we studied the effects of submicron particles (PM1.0), Parietaria officinalis (ALL), and PM1.0 + ALL together. To date several biochemical effects have been described, instead few data exist in literature regarding morphological events following these treatments, in particular we focused on the morphological changes and distribution of mitochondria, tonifilaments and rough endoplasmic reticulum, using a transmission electron microscopic (TEM) approach. After exposure to PM1.0 particles (PM1.0), Parietaria officinalis as allergen, and PM1.0 with P. officinalis, changes in the cytoplasmic area were observed, such as damage to mitochondria and morphological alterations of the tonifilaments and rough endoplasmic reticulum. The data obtained strongly support the hypothesis that cells in contact with submicron particles (PM1.0), or P. officinalis, undergo alteration of their metabolism. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  8. A methodology for modeling photocatalytic reactors for indoor pollution control using previously estimated kinetic parameters

    Energy Technology Data Exchange (ETDEWEB)

    Passalia, Claudio; Alfano, Orlando M. [INTEC - Instituto de Desarrollo Tecnologico para la Industria Quimica, CONICET - UNL, Gueemes 3450, 3000 Santa Fe (Argentina); FICH - Departamento de Medio Ambiente, Facultad de Ingenieria y Ciencias Hidricas, Universidad Nacional del Litoral, Ciudad Universitaria, 3000 Santa Fe (Argentina); Brandi, Rodolfo J., E-mail: rbrandi@santafe-conicet.gov.ar [INTEC - Instituto de Desarrollo Tecnologico para la Industria Quimica, CONICET - UNL, Gueemes 3450, 3000 Santa Fe (Argentina); FICH - Departamento de Medio Ambiente, Facultad de Ingenieria y Ciencias Hidricas, Universidad Nacional del Litoral, Ciudad Universitaria, 3000 Santa Fe (Argentina)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Indoor pollution control via photocatalytic reactors. Black-Right-Pointing-Pointer Scaling-up methodology based on previously determined mechanistic kinetics. Black-Right-Pointing-Pointer Radiation interchange model between catalytic walls using configuration factors. Black-Right-Pointing-Pointer Modeling and experimental validation of a complex geometry photocatalytic reactor. - Abstract: A methodology for modeling photocatalytic reactors for their application in indoor air pollution control is carried out. The methodology implies, firstly, the determination of intrinsic reaction kinetics for the removal of formaldehyde. This is achieved by means of a simple geometry, continuous reactor operating under kinetic control regime and steady state. The kinetic parameters were estimated from experimental data by means of a nonlinear optimization algorithm. The second step was the application of the obtained kinetic parameters to a very different photoreactor configuration. In this case, the reactor is a corrugated wall type using nanosize TiO{sub 2} as catalyst irradiated by UV lamps that provided a spatially uniform radiation field. The radiative transfer within the reactor was modeled through a superficial emission model for the lamps, the ray tracing method and the computation of view factors. The velocity and concentration fields were evaluated by means of a commercial CFD tool (Fluent 12) where the radiation model was introduced externally. The results of the model were compared experimentally in a corrugated wall, bench scale reactor constructed in the laboratory. The overall pollutant conversion showed good agreement between model predictions and experiments, with a root mean square error less than 4%.

  9. Pore-scale capillary pressure analysis using multi-scale X-ray micromotography

    Science.gov (United States)

    Garing, Charlotte; de Chalendar, Jacques A.; Voltolini, Marco; Ajo-Franklin, Jonathan B.; Benson, Sally M.

    2017-06-01

    A multi-scale synchrotron-based X-ray microtomographic dataset of residually trapped air after gravity-driven brine imbibition was acquired for three samples with differing pore topologies and morphologies; image volumes were reconstructed with voxel sizes from 4.44 μm down to 0.64 μm. Capillary pressure distributions among the population of trapped ganglia were investigated by calculating interfacial curvature in order to assess the potential for remobilization of residually-trapped non-wetting ganglia due to differences in capillary pressure presented by neighbor ganglia. For each sample, sintered glass beads, Boise sandstone and Fontainebleau sandstone, sub-volumes with different voxel sizes were analyzed to quantify air/brine interfaces and interfacial curvatures and investigate the effect of image resolution on both fluid phase identification and curvature estimates. Results show that the method developed for interfacial curvature estimation leads to reliable capillary pressure estimates for gas ganglia. Higher resolution images increase confidence in curvature calculations, especially for the sandstone samples that display smaller gas-brine interfaces which are then represented by a higher number of voxels when imaged with a micron or sub-micron voxels size. The analysis of sub-volumes from the Boise and Fontainebleau dataset highlights the presence of a residually-trapped gas phase consisting of ganglia located in one or few pores and presenting significantly different capillary pressures, especially in the case of Fontainebleau sandstone. As a result, Ostwald ripening could occur, leading to gas transfer from ganglia with higher capillary pressure to surrounding ganglia with lower capillary pressures. More generally, at the pore-scale, most gas ganglia do present similar capillary pressures and Ostwald ripening would then not represent a major mechanism for residually-trapped gas transfer and remobilization.

  10. Comparative genomics of grass EST libraries reveals previously uncharacterized splicing events in crop plants.

    Science.gov (United States)

    Chuang, Trees-Juen; Yang, Min-Yu; Lin, Chuang-Chieh; Hsieh, Ping-Hung; Hung, Li-Yuan

    2015-02-05

    Crop plants such as rice, maize and sorghum play economically-important roles as main sources of food, fuel, and animal feed. However, current genome annotations of crop plants still suffer false-positive predictions; a more comprehensive registry of alternative splicing (AS) events is also in demand. Comparative genomics of crop plants is largely unexplored. We performed a large-scale comparative analysis (ExonFinder) of the expressed sequence tag (EST) library from nine grass plants against three crop genomes (rice, maize, and sorghum) and identified 2,879 previously-unannotated exons (i.e., novel exons) in the three crops. We validated 81% of the tested exons by RT-PCR-sequencing, supporting the effectiveness of our in silico strategy. Evolutionary analysis reveals that the novel exons, comparing with their flanking annotated ones, are generally under weaker selection pressure at the protein level, but under stronger pressure at the RNA level, suggesting that most of the novel exons also represent novel alternatively spliced variants (ASVs). However, we also observed the consistency of evolutionary rates between certain novel exons and their flanking exons, which provided further evidence of their co-occurrence in the transcripts, suggesting that previously-annotated isoforms might be subject to erroneous predictions. Our validation showed that 54% of the tested genes expressed the newly-identified isoforms that contained the novel exons, rather than the previously-annotated isoforms that excluded them. The consistent results were steadily observed across cultivated (Oryza sativa and O. glaberrima) and wild (O. rufipogon and O. nivara) rice species, asserting the necessity of our curation of the crop genome annotations. Our comparative analyses also inferred the common ancestral transcriptome of grass plants and gain- and loss-of-ASV events. We have reannotated the rice, maize, and sorghum genomes, and showed that evolutionary rates might serve as an indicator

  11. Effects of resistance training on performance in previously trained endurance runners: A systematic review.

    Science.gov (United States)

    Alcaraz-Ibañez, Manuel; Rodríguez-Pérez, Manuel

    2018-03-01

    The aim of this work was to identify, synthesize and evaluate the results of randomized controlled trials examining the effects of resistance training on performance indicators in previously trained endurance runners. A database search was carried out in PubMed, Science Direct, OvidSPMedLine, Wiley, Web of Science, ProQuest and Google Scholar. In accordance with the PRISMA checklist, 18 published articles dated prior to May 2016 involving 321 endurance runners were reviewed using the PEDro scale. Resistance training led to general improvements in muscular strength, running economy, muscle power factors, and direct performance in distances between 1,500 and 10,000 m. Such improvements were not accompanied by a significant increase in body mass or signs of overtraining. However, improvements did not occur in all cases, suggesting that they might depend on the specific characteristics of the resistance training applied. Although current evidence supports the effectiveness of resistance training to improve performance in already trained endurance runners, the methodological inconsistencies identified suggest that the results should be interpreted with caution. Future studies ought to investigate the benefits of resistance training in endurance runners while considering the existence of possible differentiated effects based on the specific characteristics of the resistance training carried out.

  12. Tempering Expectations of Recovery for Previously Exploited Populations in a Fully Protected Marine Reserve

    Directory of Open Access Journals (Sweden)

    Jennifer K. Schultz

    2011-01-01

    Full Text Available Centuries of resource extraction have impacted coral reef ecosystems worldwide. In response, area and fishery closures are often enacted to restore previously exploited populations and reestablish diminished ecosystem function. During the 19th and 20th centuries, monk seals, pearl oysters, and two lobster species were overharvested in the Northwestern Hawaiian Islands, now managed as the Papahānaumokuākea Marine National Monument, one of the largest conservation areas in the world. Despite years of protection, these taxa have failed to recover. Here, we review each case, discussing possible factors that limit population growth, including: Allee effects, interspecific interactions, and time lags. Additionally, large-scale climate changes may have altered the overall productivity of the system. We conclude that overfishing of coral reef fauna may have broad and lasting results; once lost, valuable resources and services do not quickly rebound to pre-exploitation levels. In such instances, management options may be limited to difficult choices: waiting hundreds of years for recovery, actively restoring populations, or accepting the new, often less desirable, alternate state.

  13. Characterization of submicron particles influenced by mixed biogenic and anthropogenic emissions using high-resolution aerosol mass spectrometry: results from CARES

    Energy Technology Data Exchange (ETDEWEB)

    Setyan, Ari; Zhang, Qi; Merkel, M.; Knighton, Walter B.; Sun, Y.; Song, Chen; Shilling, John E.; Onasch, Timothy B.; Herndon, Scott C.; Worsnop, Douglas R.; Fast, Jerome D.; Zaveri, Rahul A.; Berg, Larry K.; Wiedensohler, A.; Flowers, B. A.; Dubey, Manvendra K.; Subramanian, R.

    2012-09-11

    The Carbonaceous Aerosols and Radiative Effects Study (CARES) took place in the Sacramento Valley of California in summer 2010. We present results obtained at Cool, CA, the T1 site of the project ({approx}40 km downwind of urban emissions from Sacramento), where we deployed an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) in parallel with complementary instrumentation to characterize the sources and processes of submicron particles (PM1). Cool is located at the foothill of the Sierra Nevada Mountains, where intense biogenic emissions are periodically mixed with urban outflow transported by daytime southwesterly winds from the Sacramento metropolitan area. The particle mass loading was low (3.0 {micro}gm{sup -3} on average) and dominated by organics (80% of the PM1 mass) followed by sulfate (9.9 %). Organics and sulfate appeared to be externally mixed, as suggested by their different time series (r2 = 0.13) and size distributions. Sulfate showed a bimodal distribution with a droplet mode peaking at {approx}400nm in vacuum aerodynamic diameter (Dva), and a condensation mode at {approx}150 nm, while organics generally displayed a broad distribution in 60-600nm (Dva). New particle formation and growth events were observed almost every day, emphasizing the roles of organics and sulfate in new particle growth, especially that of organics. The organic aerosol (OA) had a nominal formula of C{sub 1}H{sub 1.38}N{sub 0.004}O{sub 0.44}, thus an average organic mass-to-carbon (OM/OC) ratio of 1.70. Two different oxygenated OA (OOA, 90% of total OA mass) and a hydrocarbon-like OA (HOA, 10 %) were identified by Positive matrix factorization (PMF) of the high resolution mass spectra. The more oxidized MO-OOA (O/C = 0.54) corresponded to secondary OA (SOA) primarily influenced by biogenic emissions, while the less oxidized LO-OOA (O/C = 0.42) corresponded to SOA associated with urban transport. The HOA factor corresponded to primary emissions mainly

  14. On the sub-micron aerosol size distribution in a coastal-rural site at El Arenosillo Station (SW – Spain

    Directory of Open Access Journals (Sweden)

    M. Sorribas

    2011-11-01

    Full Text Available This study focuses on the analysis of the sub-micron aerosol characteristics at El Arenosillo Station, a rural and coastal environment in South-western Spain between 1 August 2004 and 31 July 2006 (594 days. The mean total concentration (NT was 8660 cm−3 and the mean concentrations in the nucleation (NNUC, Aitken (NAIT and accumulation (NACC particle size ranges were 2830 cm−3, 4110 cm−3 and 1720 cm−3, respectively. Median size distribution was characterised by a single-modal fit, with a geometric diameter, median number concentration and geometric standard deviation of 60 nm, 5390 cm−3 and 2.31, respectively. Characterisation of primary emissions, secondary particle formation, changes to meteorology and long-term transport has been necessary to understand the seasonal and annual variability of the total and modal particle concentration. Number concentrations exhibited a diurnal pattern with maximum concentrations around noon. This was governed by the concentrations of the nucleation and Aitken modes during the warm seasons and only by the nucleation mode during the cold seasons. Similar monthly mean total concentrations were observed throughout the year due to a clear inverse variation between the monthly mean NNUC and NACC. It was related to the impact of desert dust and continental air masses on the monthly mean particle levels. These air masses were associated with high values of NACC which suppressed the new particle formation (decreasing NNUC. Each day was classified according to a land breeze flow or a synoptic pattern influence. The median size distribution for desert dust and continental aerosol was dominated by the Aitken and accumulation modes, and marine air masses were dominated by the nucleation and Aitken modes. Particles

  15. Seasonal variations of ultra-fine and submicron aerosols in Taipei, Taiwan: implications for particle formation processes in a subtropical urban area

    Directory of Open Access Journals (Sweden)

    H. C. Cheung

    2016-02-01

    Full Text Available The aim of this study is to investigate the seasonal variations in the physicochemical properties of atmospheric ultra-fine particles (UFPs, d ≤ 100 nm and submicron particles (PM1, d ≤ 1 µm in an east Asian urban area, which are hypothesized to be affected by the interchange of summer and winter monsoons. An observation experiment was conducted at TARO (Taipei Aerosol and Radiation Observatory, an urban aerosol station in Taipei, Taiwan, from October 2012 to August 2013. The measurements included the mass concentration and chemical composition of UFPs and PM1, as well as the particle number concentration (PNC and the particle number size distribution (PSD with size range of 4–736 nm. The results indicated that the mass concentration of PM1 was elevated during cold seasons with a peak level of 18.5 µg m−3 in spring, whereas the highest concentration of UFPs was measured in summertime with a mean of 1.64 µg m−3. Moreover, chemical analysis revealed that the UFPs and PM1 were characterized by distinct composition; UFPs were composed mostly of organics, whereas ammonium and sulfate were the major constituents of PM1. The seasonal median of total PNCs ranged from 13.9  ×  103 cm−3 in autumn to 19.4  ×  103 cm−3 in spring. Median concentrations for respective size distribution modes peaked in different seasons. The nucleation-mode PNC (N4 − 25 peaked at 11.6  ×  103 cm−3 in winter, whereas the Aitken-mode (N25 − 100 and accumulation-mode (N100 − 736 PNC exhibited summer maxima at 6.0  ×  103 and 3.1  ×  103 cm−3, respectively. The change in PSD during summertime was attributed to the enhancement in the photochemical production of condensable organic matter that, in turn, contributed to the growth of aerosol particles in the atmosphere. In addition, clear photochemical production of particles was observed, mostly in the summer season

  16. A Note on Scale Economies in Transport

    National Research Council Canada - National Science Library

    Tae Hoon Oum; Yimin Zhang

    1997-01-01

    .... Using the results previously obtained by Caves et al. (1984, 1985), and incorporating the estimated link between operating characteristics and scale of outputs, mildly increasing returns for the airline sample in Caves et al. (1984...

  17. Comparison of knowledge, perception and attitudes of concussion in previously concussed versus non-concussed youth soccer players.

    Science.gov (United States)

    Myrdal, Caitlyn N; Huang, Shuang; Beach, Holly N; Waterbrook, Anna L

    2017-09-01

    To examine if history of concussion is correlated with a difference in knowledge, attitude, and perception of concussive injuries in youth soccer players. A convenience sample of youth soccer athletes aged 14 to 18 years completed a survey assessing prior history of concussive injury, knowledge of concussive injury, self-reporting attitudes, and perception of the injury. The survey consists of 16 knowledge questions (eleven on a scale of 1-2, and five on a scale of 1-4) and 12 attitude questions (seven on a scale of 1-4, and five on a scale of 1-5). The primary outcomes are the total scores calculated by summing the standardized raw scores for all knowledge questions and attitude questions, respectively. Linear regression was used to estimate the mean difference in the primary outcomes between previously concussed and non-concussed athletes (calculated as previously concussed - non-concussed). Surveys were obtained from 90 athletes, with 32 (36%) previously sustaining at least one concussion. Thirty-one out of these 32 concussions were diagnosed by a medical provider. On average, the mean total raw scores of all knowledge questions are 34.6 (82.2% of 42 possible points) and 33.7 (80.2% of 42 total points) for previously concussed and non-concussed athletes, respectively, and the mean total raw scores of all attitude questions are 38.7 (72.9% of 53 possible points) and 39.6 (74.7% of 53 possible points), respectively. Mean differences estimated from univariate linear regression in the standardized total scores of knowledge questions and attitude questions are 1.56(95% confidence interval: -1.52-4.65) and -1.23 (%95 confidence interval: -4.64-2.19), respectively. Adjusting for age and years of playing soccer gave similar results. Although we did not find significant differences between previously concussed and non-concussed athletes in either the knowledge or the attitude questions as measured by their total scores, this study showed a high level of awareness of

  18. Production of fine zinc borate in industrial scale

    National Research Council Canada - National Science Library

    Çakal Gaye Ö

    2012-01-01

    In this study, zinc borate production in an industrial scale batch reactor was carried out at the optimum process conditions determined in the previous studies performed at the laboratory and pilot scale reactors...

  19. Re-scaling Landscape. Re-scaling Identity

    Directory of Open Access Journals (Sweden)

    Julia Sulina

    2012-05-01

    Full Text Available To understand the bonds cultural groups living in Estonia have with their cultural landscape and why they identify themselves with a particular territory (region, the general process of presenting the landscape role in their identity needs to be analysed. Scales of landscape and regional identity of cultural groups are examined as belonging to different historical social formation periods, including nowadays, also taking into account the identity and physical setting relationship, as well as the results of questionnaires and previous studies. The tendency is that becoming more open the society is influenced by globalisation, new technologies and freedom of movement, thus changing both the identities and landscapes scales.

  20. Universal geometrical scaling of the elliptic flow

    Directory of Open Access Journals (Sweden)

    Andrés C.

    2015-01-01

    Full Text Available The presence of scaling variables in experimental observables provide very valuable indications of the dynamics underlying a given physical process. In the last years, the search for geometric scaling, that is the presence of a scaling variable which encodes all geometrical information of the collision as well as other external quantities as the total energy, has been very active. This is motivated, in part, for being one of the genuine predictions of the Color Glass Condensate formalism for saturation of partonic densities. Here we extend these previous findings to the case of experimental data on elliptic flow. We find an excellent scaling for all centralities and energies, from RHIC to LHC, with a simple generalization of the scaling previously found for other observables and systems. Interestingly, the case of the photons, difficult to reconcile in most formalisms, nicely fit the scaling curve. We discuss on the possible interpretations of this finding in terms of initial or final state effects.

  1. Kalman plus weights: a time scale algorithm

    Science.gov (United States)

    Greenhall, C. A.

    2001-01-01

    KPW is a time scale algorithm that combines Kalman filtering with the basic time scale equation (BTSE). A single Kalman filter that estimates all clocks simultaneously is used to generate the BTSE frequency estimates, while the BTSE weights are inversely proportional to the white FM variances of the clocks. Results from simulated clock ensembles are compared to previous simulation results from other algorithms.

  2. New silicon photonics integration platform enabled by novel micron-scale bends

    CERN Document Server

    Cherchi, Matteo; Harjanne, Mikko; Kapulainen, Markku; Aalto, Timo

    2013-01-01

    Even though submicron silicon waveguides have been proposed for dense integration of photonic devices, to date the lightwave circuits on the market mainly rely on waveguides with micron-scale core dimensions. These larger waveguides feature easier fabrication, higher reliability and better interfacing to optical fibres. Single-mode operation with large core dimensions is obtained with low lateral refractive index contrast. Hence, the main limitation in increasing the level of integration and in reducing the cost of micron-scale waveguide circuits is their mm- to cm-scale minimum bending radius. Fortunately, single-mode rib waveguides with a micron-scale silicon core can be locally transformed into multi-mode strip waveguides that have very high lateral index contrast. Here we show how Euler spiral bends realized with these waveguides can have bending radii below 10 {\\mu}m and losses below 0.02 dB/90{\\deg} for the fundamental mode, paving way for a novel densely integrated platform based on micron-scale wavegu...

  3. The Relationship of Previous Training and Experience of Journal Peer Reviewers to Subsequent Review Quality

    Science.gov (United States)

    Callaham, Michael L; Tercier, John

    2007-01-01

    Background Peer review is considered crucial to the selection and publication of quality science, but very little is known about the previous experiences and training that might identify high-quality peer reviewers. The reviewer selection processes of most journals, and thus the qualifications of their reviewers, are ill defined. More objective selection of peer reviewers might improve the journal peer review process and thus the quality of published science. Methods and Findings 306 experienced reviewers (71% of all those associated with a specialty journal) completed a survey of past training and experiences postulated to improve peer review skills. Reviewers performed 2,856 reviews of 1,484 separate manuscripts during a four-year study period, all prospectively rated on a standardized quality scale by editors. Multivariable analysis revealed that most variables, including academic rank, formal training in critical appraisal or statistics, or status as principal investigator of a grant, failed to predict performance of higher-quality reviews. The only significant predictors of quality were working in a university-operated hospital versus other teaching environment and relative youth (under ten years of experience after finishing training). Being on an editorial board and doing formal grant (study section) review were each predictors for only one of our two comparisons. However, the predictive power of all variables was weak. Conclusions Our study confirms that there are no easily identifiable types of formal training or experience that predict reviewer performance. Skill in scientific peer review may be as ill defined and hard to impart as is “common sense.” Without a better understanding of those skills, it seems unlikely journals and editors will be successful in systematically improving their selection of reviewers. This inability to predict performance makes it imperative that all but the smallest journals implement routine review ratings systems to

  4. Impaired insulin-stimulated nonoxidative glucose metabolism in glucose-tolerant women with previous gestational diabetes

    DEFF Research Database (Denmark)

    Damm, P; Vestergaard, H; Kühl, Carl Erik

    1996-01-01

    Our purpose was to investigate insulin sensitivity and insulin secretion in women with previous gestational diabetes.......Our purpose was to investigate insulin sensitivity and insulin secretion in women with previous gestational diabetes....

  5. Generalized expectancies for negative mood regulation and major depressive disorder: the role of previous depressive episodes and comorbid mental disorders.

    Science.gov (United States)

    Pfeiffer, Nils; Kaemmerer, Annette; Mearns, Jack; Catanzaro, Salvatore J; Backenstrass, Matthias

    2011-01-01

    Generalized expectancies for negative mood regulation (NMR) have important consequences for the ability to regulate negative mood. This study tests two resulting hypotheses. NMR expectancies should correlate with the number of previous depressive episodes. Furthermore, there should be a correlation between NMR expectancies and the number of DSM-IV axis I disorders comorbid to depression. In order to test these hypotheses with an efficient instrument, this article presents the NMR-SF as a short form of the NMR Scale. During inpatient treatment, a sample of 40 depressed patients was interviewed by a clinical psychologist with the Structural Clinical Interview for DSM-IV to assess the number of previous depressive episodes as well as the number of axis I comorbidities. Patients completed the NMR-SF to measure NMR expectancies. Additionally, a nonclinical sample of 560 participants completed the NMR-SF to test its reliability and validity. The findings indicate that the NMR-SF is reliable and valid. In the clinical sample, NMR expectancies did not correlate significantly with the number of previous depressive episodes. There was a significant correlation between NMR expectancies and the number of comorbid mental disorders. Previous depressive episodes do not seem to result in lower NMR expectancies. The findings are in line with the hypothesis that NMR expectancies are involved in the etiology of mental disorders comorbid to depression. Copyright © 2011 S. Karger AG, Basel.

  6. The relationship between emotional intelligence, previous caring experience and mindfulness in student nurses and midwives: a cross sectional analysis.

    Science.gov (United States)

    Snowden, Austyn; Stenhouse, Rosie; Young, Jenny; Carver, Hannah; Carver, Fiona; Brown, Norrie

    2015-01-01

    Emotional Intelligence (EI), previous caring experience and mindfulness training may have a positive impact on nurse education. More evidence is needed to support the use of these variables in nurse recruitment and retention. To explore the relationship between EI, gender, age, programme of study, previous caring experience and mindfulness training. Cross sectional element of longitudinal study. 938year one nursing, midwifery and computing students at two Scottish Higher Education Institutes (HEIs) who entered their programme in September 2013. Participants completed a measure of 'trait' EI: Trait Emotional Intelligence Questionnaire Short Form (TEIQue-SF); and 'ability' EI: Schutte's et al. (1998) Emotional Intelligence Scale (SEIS). Demographics, previous caring experience and previous training in mindfulness were recorded. Relationships between variables were tested using non-parametric tests. Emotional intelligence increased with age on both measures of EI [TEIQ-SF H(5)=15.157 p=0.001; SEIS H(5)=11.388, p=0.044]. Females (n=786) scored higher than males (n=149) on both measures [TEIQ-SF, U=44,931, z=-4.509, pintelligence. Mindfulness training was associated with higher 'ability' emotional intelligence. Implications for recruitment, retention and further research are explored. Copyright © 2014. Published by Elsevier Ltd.

  7. Role of ammonium ion and transition metals in the formation of secondary organic aerosol and metallo-organic complex within fog processed ambient deliquescent submicron particles collected in central part of Indo-Gangetic Plain.

    Science.gov (United States)

    Singh, Dharmendra Kumar; Gupta, Tarun

    2017-08-01

    In this study we observed the role of ammonium ion (NH4+) and transition metals (Fe, Mn, Cr, and Cu) present in ambient submicron particles in stabilizing and enhancing the yield of water soluble organic carbon (WSOC). A good correlation of WSOC with transition metals and NH4+ was found (R2 = 0.87 and 0.71), respectively within foggy episode collected ambient PM1 (particles having aerodynamic diameter ≤1.0 μm) suggesting plausibleness of alternate oxidation (primarily various carbonyls into their respective organic acids, esters and other derivatives.) and aging mechanisms. Molar concentration of ammonium ion was observed to be exceeded over and above to require in neutralizing the sulphate and nitrate which further hints its role in the neutralization, stabilization and enhancement of subset of WSOC such as water soluble organic acids. Transition metals were further apportioned using enrichment factor analysis. The source of Fe, Mn, and Cr was found to be crustal and Cu was tagged to anthropogenic origin. This study also described the plausible role of significant predictors (Fe and Cu) in the secondary organic aerosol (SOA) formation through effect of Fenton chemistry. Mass-to-charge ratio of identified oxalic acid from our published recent field study (carried out from same sampling location) was used for understanding the possible metallo-organic complex with Fe supports the substantial role of Fe in SOA formation in the deliquescent submicron particles facilitated by aqueous-phase chemistry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Effects of chemical composition and mixing state on size-resolved hygroscopicity and cloud condensation nuclei activity of submicron aerosols at a suburban site in northern Japan in summer

    Science.gov (United States)

    Müller, Astrid; Miyazaki, Yuzo; Aggarwal, Shankar G.; Kitamori, Yasuyuki; Boreddy, Suresh K. R.; Kawamura, Kimitaka

    2017-09-01

    Ambient hygroscopic properties, numbers of size-segregated cloud condensation nuclei (CCN) at different supersaturations (0.1%-0.8%), and the chemical composition of submicron particles were simultaneously measured at a suburban site in northern Japan in summer. Two distinct periods with different growth factors (GF), CCN activation diameters, and chemical compositions were observed. The data suggest that internally mixed sulfate aerosols dominated the accumulation size mode in relatively aged aerosols during the first period, whereas particles observed during the latter periods showed external mixing dominated by organics, which was linked to low hygroscopicity and CCN activity. In particular, the higher loading of water-soluble organic matter (WSOM; 60% of OM by mass) with increased WSOM/sulfate ratios corresponded to a low hygroscopicity parameter derived from the CCN measurement (κCCN = 0.15 ± 0.02) at a dry diameter (Ddry) of 146 nm. The results suggest that WSOM, likely dominated by the influence of biogenic sources, contributed to reducing the hygroscopicity and CCN activation at this particle size. Temporal variations in the number concentrations for low GF mode at Ddry = 49.6 nm were similar to those in the elemental carbon (EC) concentration, suggesting that EC contributed to reducing hygroscopicity at this smaller size. Our results suggest that chemical composition and mixing state are important factors controlling the hygroscopicity and CCN activation of submicron particles. These results provide useful data sets of size-resolved subsaturated and supersaturated hygroscopicity and highlight the importance of the abundance of OM relative to sulfate in predicting the effects on climate change.

  9. 78 FR 11567 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2013-02-19

    ... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Airplanes AGENCY... Previously Held by Israel Aircraft Industries, Ltd.) Model Gulfstream G150 airplanes. This AD was prompted by...: 2013-03-23 Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd...

  10. 77 FR 44432 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2012-07-30

    ... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Airplanes AGENCY... previously held by Israel Aircraft Industries, Ltd.) Model Astra SPX, 1125 Westwind Astra, and Gulfstream 100... new AD: 2012-15-06 Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft...

  11. 77 FR 64767 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2012-10-23

    ... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Airplanes AGENCY... airworthiness directive (AD) for certain Gulfstream Aerospace LP (Type Certificate previously held by Israel... Certificate previously held by Israel Aircraft Industries, Ltd.) Model Galaxy and Gulfstream 200 airplanes...

  12. 76 FR 70040 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2011-11-10

    ... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Airplanes AGENCY... previously held by Israel Aircraft Industries, Ltd.) Model Galaxy and Gulfstream G150 airplanes; and...: 2011-23-07 Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd...

  13. 40 CFR 152.93 - Citation of a previously submitted valid study.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Citation of a previously submitted... Data Submitters' Rights § 152.93 Citation of a previously submitted valid study. An applicant may... the citation is necessary. (b) Study previously submitted by another person. If the applicant is not...

  14. 76 FR 1349 - Airworthiness Directives; Cessna Aircraft Company (Cessna) (Type Certificate A00003SE Previously...

    Science.gov (United States)

    2011-01-10

    ... Company (Cessna) (Type Certificate A00003SE Previously Held by Columbia Aircraft Manufacturing (Previously... airworthiness directive (AD): 2010-26-54 Cessna Aircraft Company (Type Certificate A00003SE previously held by...) None. Applicability (c) This AD applies to the following Cessna Aircraft Company (Cessna) (Type...

  15. The Unintentional Procrastination Scale.

    Science.gov (United States)

    Fernie, Bruce A; Bharucha, Zinnia; Nikčević, Ana V; Spada, Marcantonio M

    2017-01-01

    Procrastination refers to the delay or postponement of a task or decision and is often conceptualised as a failure of self-regulation. Recent research has suggested that procrastination could be delineated into two domains: intentional and unintentional. In this two-study paper, we aimed to develop a measure of unintentional procrastination (named the Unintentional Procrastination Scale or the 'UPS') and test whether this would be a stronger marker of psychopathology than intentional and general procrastination. In Study 1, a community sample of 139 participants completed a questionnaire that consisted of several items pertaining to unintentional procrastination that had been derived from theory, previous research, and clinical experience. Responses were subjected to a principle components analysis and assessment of internal consistency. In Study 2, a community sample of 155 participants completed the newly developed scale, along with measures of general and intentional procrastination, metacognitions about procrastination, and negative affect. Data from the UPS were subjected to confirmatory factor analysis and revised accordingly. The UPS was then validated using correlation and regression analyses. The six-item UPS possesses construct and divergent validity and good internal consistency. The UPS appears to be a stronger marker of psychopathology than the pre-existing measures of procrastination used in this study. Results from the regression models suggest that both negative affect and metacognitions about procrastination differentiate between general, intentional, and unintentional procrastination. The UPS is brief, has good psychometric properties, and has strong associations with negative affect, suggesting it has value as a research and clinical tool.

  16. SCIL nanoimprint solutions: high-volume soft NIL for wafer scale sub-10nm resolution

    Science.gov (United States)

    Voorkamp, R.; Verschuuren, M. A.; van Brakel, R.

    2016-10-01

    Nano-patterning materials and surfaces can add unique functionalities and properties which cannot be obtained in bulk or micro-structured materials. Examples range from hetro-epitaxy of semiconductor nano-wires to guiding cell expression and growth on medical implants. [1] Due to the cost and throughput requirements conventional nano-patterning techniques such as deep UV lithography (cost and flat substrate demands) and electron-beam lithography (cost, throughput) are not an option. Self-assembly techniques are being considered for IC manufacturing, but require nano-sized guiding patterns, which have to be fabricated in any case.[2] Additionally, the self-assembly process is highly sensitive to the environment and layer thickness, which is difficult to control on non-flat surfaces such as PV silicon wafers or III/V substrates. Laser interference lithography can achieve wafer scale periodic patterns, but is limited by the throughput due to intensity of the laser at the pinhole and only regular patterns are possible where the pattern fill fraction cannot be chosen freely due to the interference condition.[3] Nanoimprint lithography (NIL) is a promising technology for the cost effective fabrication of sub-micron and nano-patterns on large areas. The challenges for NIL are related to the technique being a contact method where a stamp which holds the patterns is required to be brought into intimate contact with the surface of the product. In NIL a strong distinction is made between the type of stamp used, either rigid or soft. Rigid stamps are made from patterned silicon, silica or plastic foils and are capable of sub-10nm resolution and wafer scale patterning. All these materials behave similar at the micro- to nm scale and require high pressures (5 - 50 Bar) to enable conformal contact to be made on wafer scales. Real world conditions such as substrate bow and particle contaminants complicate the use of rigid stamps for wafer scale areas, reducing stamp lifetime and

  17. Attribute and topology based change detection in a constellation of previously detected objects

    Science.gov (United States)

    Paglieroni, David W.; Beer, Reginald N.

    2016-01-19

    A system that applies attribute and topology based change detection to networks of objects that were detected on previous scans of a structure, roadway, or area of interest. The attributes capture properties or characteristics of the previously detected objects, such as location, time of detection, size, elongation, orientation, etc. The topology of the network of previously detected objects is maintained in a constellation database that stores attributes of previously detected objects and implicitly captures the geometrical structure of the network. A change detection system detects change by comparing the attributes and topology of new objects detected on the latest scan to the constellation database of previously detected objects.

  18. Radioiodine treatment of recurrent hyperthyroidism in patients previously treated for Graves' disease by subtotal thyroidectomy

    DEFF Research Database (Denmark)

    Vestergaard, H; Laurberg, P

    1992-01-01

    Radioiodine therapy is often employed for treatment of patients with relapse of hyperthyroidism due to Graves' disease, after previous thyroid surgery. Little is known about the outcome of this treatment compared to patients with no previous surgery. A total of 20 patients who had received surgical...... treatment for Graves' hyperthyroidism 1-46 years previously and with relapse of the hyperthyroidism, and 25 patients with hyperthyroidism due to Graves' disease and no previous thyroid surgery were treated with radioiodine, following the same protocol. Early after treatment the previously operated patients...

  19. Learner Autonomy Scale: A Scale Development Study

    Science.gov (United States)

    Orakci, Senol; Gelisli, Yücel

    2017-01-01

    The goal of the study is to develop a scale named "Learner Autonomy Scale" (LAS) for determining the learner autonomy of the students toward English lesson. The proposal scale, composed of 29 items, was applied to two study groups in Turkey. The group of Exploratory Factor Analysis that aims to determine the psychometric properties…

  20. Revision and redescription of the species previously included in the genus Amphilaphis Studer and Wright in Studer, 1887 (Octocorallia: Primnoidae

    Directory of Open Access Journals (Sweden)

    Rebeca Zapata-Guardiola

    2011-11-01

    Full Text Available The taxonomy of the primnoid genus Amphilaphis Studer and Wright in Studer, 1887 has been in a confused state for a long time and a revision of the species included in that genus has become a necessity. We have revised and redescribed the species previously included in the genus using up-to-date technology, such as polyp and sclerite images obtained with scanning electron microscopy (SEM. As a result of this study, because the type species of Amphilaphis is actually a Thouarella species, we consider the genus Amphilaphis to be no longer valid. One of the species previously considered in Amphilaphis has a set of morphological characters that are not recognizable in any of the current primnoid genera. Primnocapsa n. gen. has a dichotomous branching pattern, polyps placed singly, in spirals around the branchlets, 8 opercular scales with the inner surface keeled and with 2 mounds basally and 8 marginal scales offset from the operculars. The new genus is described and illustrated. Moreover, one of the re-examined species has been included in a new subgenus, Faxiella n. subgen. of Plumarella Gray, 1870 because it has polyps placed in pairs. Finally, the remaining re-examined species have been included in the genus Thouarella Gray, 1870, one of the most specious primnoid genera.