Sputtering and ion plating

NASA Technical Reports Server (NTRS)

1972-01-01

The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

The Use af Ion Vapor Deposited Aluminum (IVD) for the Space Shuttle Solid Rocket Booster (SRB)

NASA Technical Reports Server (NTRS)

Novak, Howard L.

2002-01-01

The USA LLC Materials & Processes (M&P) Engineering Department had recommended the application and evaluation of Ion Vapor Deposition (IVD) aluminum to SRB Hardware for corrosion protection and elimination of hazardous materials and processes such as cadmium plating. IVD is an environmentally friendly process that has no volatile organic compounds (VOCs), or hazardous waste residues. It lends itself to use with hardware exposed to corrosive seacoast environments as found at Kennedy Space Center (KSC), and Cape Canaveral Air Force Station (CCAFS), Florida. Lifting apparatus initially coated with cadmium plating for corrosion protection; was stripped and successfully re-coated with IVD aluminum after the cadmium plating no longer protected the GSE from corrosion, Since then, and after completion of a significant test program, the first flight application of the IVD Aluminum process on the Drogue Parachute Ratchet Assembly is scheduled for 2002.

Sputtering and ion plating for aerospace applications

NASA Technical Reports Server (NTRS)

Spalvins, T.

1981-01-01

Sputtering and ion plating technologies are reviewed in terms of their potential and present uses in the aerospace industry. Sputtering offers great universality and flexibility in depositing any material or in the synthesis of new ones. The sputter deposition process has two areas of interest: thin film and fabrication technology. Thin film sputtering technology is primarily used for aerospace mechanical components to reduce friction, wear, erosion, corrosion, high temperature oxidation, diffusion and fatigue, and also to sputter-construct temperature and strain sensors for aircraft engines. Sputter fabrication is used in intricate aircraft component manufacturing. Ion plating applications are discussed in terms of the high energy evaporant flux and the high throwing power. Excellent adherence and 3 dimensional coverage are the primary attributes of this technology.

Sputtering and ion plating for aerospace applications

NASA Technical Reports Server (NTRS)

Spalvins, T.

1981-01-01

Sputtering and ion plating technologies are reviewed in terms of their potential and present uses in the aerospace industry. Sputtering offers great universality and flexibility in depositing any material or in the synthesis of new ones. The sputter deposition process has two areas of interest: thin film and fabrication technology. Thin film sputtering technology is primarily used for aerospace mechanical components to reduce friction, wear, erosion, corrosion, high temperature oxidation, diffusion and fatigue, and also to sputter-construct temperature and strain sensors for aircraft engines. Sputter fabrication is used in intricate aircraft component manufacturing. Ion plating applications are discussed in terms of the high energy evaporant flux and the high throwing power. Excellent adherence and 3-dimensional coverage are the primary attributes of this technology.

Optimization and testing of solid thin film lubrication deposition processes

NASA Astrophysics Data System (ADS)

Danyluk, Michael J.

A novel method for testing solid thin films in rolling contact fatigue (RCF) under ultra-high vacuum (UHV) and high rotational speeds (130 Hz) is presented in this thesis. The UHV-RCF platform is used to quantify the adhesion and lubrication aspects of two thin film coatings deposited on ball-bearings using a physical vapor deposition ion plating process. Plasma properties during ion plating were measured using a Langmuir probe and there is a connection between ion flux, film stress, film adhesion, process voltage, pressure, and RCF life. The UHV-RCF platform and vacuum chamber were constructed using off-the-shelf components and 88 RCF tests in high vacuum have been completed. Maximum RCF life was achieved by maintaining an ion flux between 10 13 to 1015 (cm-2 s-1) with a process voltage and pressure near 1.5 kV and 15 mTorr. Two controller schemes were investigated to maintain optimal plasma conditions for maximum RCF life: PID and LQR. Pressure disturbances to the plasma have a detrimental effect on RCF life. Control algorithms that mitigate pressure and voltage disturbances already exist. However, feedback from the plasma to detect disturbances has not been explored related to deposition processes in the thin-film science literature. Manometer based pressure monitoring systems have a 1 to 2 second delay time and are too slow to detect common pressure bursts during the deposition process. Plasma diagnostic feedback is much faster, of the order of 0.1 second. Plasma total-current feedback was used successfully to detect a typical pressure disturbance associated with the ion plating process. Plasma current is related to ion density and process pressure. A real-time control application was used to detect the pressure disturbance by monitoring plasma-total current and converting it to feedback-input to a pressure control system. Pressure overshoot was eliminated using a nominal PID controller with feedback from a plasma-current diagnostic measurement tool.

Plasma assisted surface coating/modification processes - An emerging technology

NASA Technical Reports Server (NTRS)

Spalvins, T.

1987-01-01

A broad understanding of the numerous ion or plasma assisted surface coating/modification processes is sought. An awareness of the principles of these processes is needed before discussing in detail the ion nitriding technology. On the basis of surface modifications arising from ion or plasma energizing and interactions, it can be broadly classified as deposition of distinct overlay coatings (sputtering-dc, radio frequency, magnetron, reactive; ion plating-diode, triode) and surface property modification without forming a discrete coating (ion implantation, ion beam mixing, laser beam irradiation, ion nitriding, ion carburizing, plasma oxidation. These techniques offer a great flexibility and are capable in tailoring desirable chemical and structural surface properties independent of the bulk properties.

Plasma assisted surface coating/modification processes: An emerging technology

NASA Technical Reports Server (NTRS)

Spalvins, T.

1986-01-01

A broad understanding of the numerous ion or plasma assisted surface coating/modification processes is sought. An awareness of the principles of these processes is needed before discussing in detail the ion nitriding technology. On the basis of surface modifications arising from ion or plasma energizing and interactions, it can be broadly classified as deposition of distinct overlay coatings (sputtering-dc, radio frequency, magnetron, reactive; ion plating-diode, triode) and surface property modification without forming a discrete coating (ion implantation, ion beam mixing, laser beam irradiation, ion nitriding, ion carburizing, plasma oxidation). These techniques offer a great flexibility and are capable in tailoring desirable chemical and structural surface properties independent of the bulk properties.

Ion plating for the future

NASA Technical Reports Server (NTRS)

Spalvins, T.

1981-01-01

The ion plating techniques are classified relative to the instrumental set up, evaporation media, and mode of transport. A distinction is drawn between the low vacuum (plasma) and high vacuum (ion beam) techniques. Ion plating technology is discussed at the fundamental and industrial level. At the fundamental level, the capabilities and limitations of the plasma (evaporant flux) and film characteristics are evaluated. And on the industrial level, the performance and potential uses of ion plated films are discussed.

Ion plating for the future

NASA Technical Reports Server (NTRS)

Spalvins, T.

1981-01-01

The ion plating techniques are classified relative to the instrumental set up, evaporation media and mode of transport. Distinction is drawn between the low vacuum (plasma) and high vacuum (ion beam) techniques. Ion plating technology is discussed at the fundamental and industrial level. At the fundamental level, the capabilities and limitations of the plasma (evaporant flux) and film characteristics are evaluated. On the industrial level, the performance and potential uses of ion plated films are discussed.

Ion cyclotron resonance cell

DOEpatents

Weller, Robert R.

1995-01-01

An ion cyclotron resonance cell having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions.

Structure of first- and second-stage mineralized elements in teeth of the sea urchin Lytechinus variegatus.

PubMed

Robach, J S; Stock, S R; Veis, A

2009-12-01

Microstructure of the teeth of the sea urchin Lytechinus variegatus was investigated using optical microscopy, SEM (scanning electron microscopy) and SIMS (secondary ion mass spectroscopy). The study focused on the internal structure of the first-stage mineral structures of high Mg calcite (primary, secondary and carinar process plates, prisms) and on morphology of the columns of second-stage mineral (very high Mg calcite) that cement the first-stage material together. Optical micrographs under polarized light revealed contrast in the centers (midlines) of carinar process plates and in prisms in polished sections; staining of primary and carinar process plates revealed significant dye uptake at the plate centers. Demineralization with and without fixation revealed that the midlines of primary and carinar process plates (but not secondary plates) and the centers of prisms differed from the rest of the plate or prism, and SIMS showed proteins concentrated in these plate centers. SEM was used to study the morphology of columns, the fracture surfaces of mature teeth and the 3D morphology of prisms. These observations of internal structures in plates and prisms offer new insight into the mineralization process and suggest an important role for protein inclusions within the first-stage mineral. Some of the 3D structures not reported previously, such as twisted prisms and stacks of carinar process plates with nested wrinkles, may represent structural strengthening strategies.

Structure of first- and second-stage mineralized elements in teeth of the sea urchin Lytechinus variegatus

PubMed Central

Robach, J. S.; Stock, S. R.; Veis, A.

2009-01-01

Microstructure of the teeth of the sea urchin Lytechinus variegatus was investigated using optical microscopy, SEM (scanning electron microscopy) and SIMS (secondary ion mass spectroscopy). The study focused on the internal structure of the first-stage mineral structures of high Mg calcite (primary, secondary and carinar process plates; prisms) and on morphology of the columns of second-stage mineral (very high Mg calcite) that cement the first-stage material together. Optical micrographs under polarized light revealed contrast in the centers (midlines) of carinar process plates and in prisms in polished sections; staining of primary and carinar process plates revealed significant dye uptake at the plate centers. Demineralization with and without fixation revealed that the midlines of primary and carinar process plates (but not secondary plates) and the centers of prisms differed from the rest of the plate or prism, and SIMS showed proteins concentrated in these plate centers. SEM was used to study the morphology of columns, the fracture surfaces of mature teeth and the 3D morphology of prisms. These observations of internal structures in plates and prisms offer new insight into the mineralization process and suggest an important role for protein inclusions within the first-stage mineral. Some of the 3D structures not reported previously, such as twisted prisms and stacks of carinar process plates with nested wrinkles, may represent structural strengthening strategies. PMID:19616101

Electrochemical decomposition of fluorinated wetting agents in plating industry waste water.

PubMed

Fath, Andreas; Sacher, Frank; McCaskie, John E

2016-01-01

Electrochemical decomposition of fluorinated surfactants (PFAS, perfluorinated alkyl substances) used in the plating industry was analyzed and the decomposition process parameters optimized at the laboratory scale and production scale of a 500-liter reactor using lead electrodes. The method and system was successfully demonstrated under production conditions to treat PFAS) with up to 99% efficiency in the concentration range of 1,000-20,000 μg/l (1 ppm-20 ppm). The treatment also reduced hexavalent chromium (Cr(6+)) ions to trivalent chromium (Cr(3+)) ions in the wastewater. If the PFAS-containing wastewater is mixed with other wastewater streams, specifically from nickel plating drag out solution or when pH values >5, the treatment process is ineffective. For the short chain PFAS, (perfluorobutylsulfonate) the process was less efficient than C6-C8 PFAS. The process is automated and has safety procedures and controls to prevent hazards. The PFAS were decomposed to hydrogen fluoride (HF) under the strong acid electrochemical operating conditions. Analytical tests showed no evidence of organic waste products remaining from the process. Conventional alternative PFAS removal systems were tested on the waste streams and compared with each other and with the-E-destruct (electrochemical oxidation) process. For example, ion exchange resin (IX resin) treatment of wastewater to complex and remove PFAS was found to be seven times more efficient when compared to the conventional activated carbon absorption (C-treat) process. However, the E-destruct process is higher in capacity, exhibits longer service life and lower operating costs than either IX or C-treat methods for elimination of PFAS from these electroplating waste streams.

Ion cyclotron resonance cell

DOEpatents

Weller, R.R.

1995-02-14

An ion cyclotron resonance cell is disclosed having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions. 5 figs.

Metal vapor arc ion plating

DOEpatents

Bertram, L.A.; Fisher, R.W.; Mattox, D.M.; Zanner, F.J.

1986-09-09

A method and apparatus for ion plating are described. The apparatus uses more negative than a first electrode voltage in a vacuum arc remelt system to attract low energy ions from the anode electrode to the article to be plated. 2 figs.

Industrial Processes to Reduce Generation of Hazardous Waste at DoD facilities. Phase 3 Report. Summary of Projects of Excellence Workshops

DTIC Science & Technology

1985-12-01

cation impurities from the plating solution and anodes to oxidize trivalent chromium to hexavalent chromium . Hexa- . valent chromium ions remain on the...corrosion, or to improve its engineering properties (harlness, durability, solderability, or frictional characteristics). Chromium ic used principally...facturing consists of machining the worn part or stripping a portion of the old plate, overplating it with a thick layer of chromium (hard chrome plating

Ion plating with an induction heating source

NASA Technical Reports Server (NTRS)

Spalvins, T.; Brainard, W. A.

1976-01-01

Induction heating is introduced as an evaporation heat source in ion plating. A bare induction coil without shielding can be directly used in the glow discharge region with no arcing. The only requirement is to utilize an rf inductive generator with low operating frequency of 75 kHz. Mechanical simplicity of the ion plating apparatus and ease of operation is a great asset for industrial applications; practically any metal such as nickel, iron, and the high temperature refractories can be evaporated and ion plated.

Bactericidal effects of negative air ions on airborne and surface Salmonella enteritidis from an artificially generated aerosol.

PubMed

Seo, K H; Mitchell, B W; Holt, P S; Gast, R K

2001-01-01

The bactericidal effect of high levels of negative ions was studied using a custom-built electrostatic space charge device. To investigate whether the ion-enriched air exerted a bactericidal effect, an aerosol containing Salmonella Enteritidis (SE) was pumped into a sealed plastic chamber. Plates of XLT4 agar were attached to the walls, top, and bottom of the chamber and exposed to the aerosol for 3 h with and without the ionizer treatment. The plates were then removed from the chamber, incubated at 37 degrees C for 24 h, and colonies were counted. An average of greater than 10(3) CFU/plate were observed on plates exposed to the aerosol without the ionizer treatment (control) compared with an average of less than 53 CFU/plate on the ionizer-treated plates. In another series of experiments, the SE aerosol was pumped for 3 h into an empty chamber containing only the ionizer and allowed to collect on the internal surfaces. The inside surfaces of the chamber were then rinsed with 100 ml phosphate-buffered saline that was then plated onto XLT4 plates. While the rinse from the control chamber contained colony counts greater than 400 CFU/ml of wash, no colonies were found in the rinse from the ionizer-treatment chamber. These results indicate that high levels of negative air ions can have a significant impact on the airborne microbial load, and that most of this effect is through direct killing of the organisms. This technology, which also causes significant reduction in airborne dust, has already been successfully applied for poultry hatching cabinets and caged layer rooms. Other potential applications include any enclosed space such as food processing areas, medical institutions, the workplace, and the home, where reduction of airborne and surface pathogens is desired.

Through-silicon via plating void metrology using focused ion beam mill

NASA Astrophysics Data System (ADS)

Rudack, A. C.; Nadeau, J.; Routh, R.; Young, R. J.

2012-03-01

3D IC integration continues to increase in complexity, employing advanced interconnect technologies such as throughsilicon vias (TSVs), wafer-to-wafer (W2W) bonding, and multi-chip stacking. As always, the challenge with developing new processes is to get fast, effective feedback to the integration engineer. Ideally this data is provided by nondestructive in-line metrology, but this is not always possible. For example, some form of physical cross-sectioning is still the most practical way to detect and characterize TSV copper plating voids. This can be achieved by cleaving, followed by scanning electron microscope (SEM) inspection. A more effective physical cross-sectioning method has been developed using an automated dual-beam focused ion beam (FIB)-SEM system, in which multiple locations can be sectioned and imaged while leaving the wafer intact. This method has been used routinely to assess copper plating voids over the last 24 months at SEMATECH. FIB-SEM feedback has been used to evaluate new plating chemistries, plating recipes, and process tool requalification after downtime. The dualbeam FIB-SEM used for these studies employs a gallium-based liquid metal ion source (LMIS). The overall throughput of relatively large volumes being milled is limited to 3-4 hours per section due to the maximum available beam current of 20 nA. Despite the larger volumetric removal rates of other techniques (e.g., mechanical polishing, broad-ion milling, and laser ablation), the value of localized, site-specific, and artifact-free FIB milling is well appreciated. The challenge, therefore, has been to reap the desired FIB benefits, but at faster volume removal rates. This has led to several system and technology developments for improving the throughput of the FIB technique, the most recent being the introduction of FIBs based on an inductively coupled plasma (ICP) ion source. The ICP source offers much better performance than the LMIS at very high beam currents, enabling more than 1 μA of ion beam current for fast material removal. At a lower current, the LMIS outperforms the ICP source, but imaging resolution below 30 nm has been demonstrated with ICP-based systems. In addition, the ICP source allows a wide range of possible ion species, with Xe currently the milling species of choice, due to its high mass and favorable ion source performance parameters. Using a 1 μA Xe beam will have an overall milling rate for silicon some 20X higher than a Ga beam operating at 65 nA. This paper will compare the benefits already seen using the Ga-based FIB-SEM approach to TSV metrology, with the improvements in throughput and time-to-data obtained by using the faster material removal capabilities of a FIB based on an ICP ion source. Plasma FIB (PFIB) is demonstrated to be a feasible tool for TSV plating void metrology.

Cell killing and chromatid damage in primary human bronchial epithelial cells irradiated with accelerated 56Fe ions

NASA Technical Reports Server (NTRS)

Suzuki, M.; Piao, C.; Hall, E. J.; Hei, T. K.

2001-01-01

We examined cell killing and chromatid damage in primary human bronchial epithelial cells irradiated with high-energy 56Fe ions. Cells were irradiated with graded doses of 56Fe ions (1 GeV/nucleon) accelerated with the Alternating Gradient Synchrotron at Brookhaven National Laboratory. The survival curves for cells plated 1 h after irradiation (immediate plating) showed little or no shoulder. However, the survival curves for cells plated 24 h after irradiation (delayed plating) had a small initial shoulder. The RBE for 56Fe ions compared to 137Cs gamma rays was 1.99 for immediate plating and 2.73 for delayed plating at the D10. The repair ratio (delayed plating/immediate plating) was 1.67 for 137Cs gamma rays and 1.22 for 56Fe ions. The dose-response curves for initially measured and residual chromatid fragments detected by the Calyculin A-mediated premature chromosome condensation technique showed a linear response. The results indicated that the induction frequency for initially measured fragments was the same for 137Cs gamma rays and 56Fe ions. On the other hand, approximately 85% of the fragments induced by 137Cs gamma rays had rejoined after 24 h of postirradiation incubation; the corresponding amount for 56Fe ions was 37%. Furthermore, the frequency of chromatid exchanges induced by gamma rays measured 24 h after irradiation was higher than that induced by 56Fe ions. No difference in the amount of chromatid damage induced by the two types of radiations was detected when assayed 1 h after irradiation. The results suggest that high-energy 56Fe ions induce a higher frequency of complex, unrepairable damage at both the cellular and chromosomal levels than 137Cs gamma rays in the target cells for radiation-induced lung cancers.

Screen Cage Ion Plating (SCIP) and scratch testing of polycrystalline aluminum oxide

NASA Technical Reports Server (NTRS)

Spalvins, Talivaldis; Sliney, Harold E.; Deadmore, Daniel L.

1992-01-01

A screen cage ion plating (SCIP) technique was developed to apply silver films on electrically nonconducting aluminum oxide. It is shown that SCIP has remarkable throwing power; surfaces to be coated need not be in direct line of sight with the evaporation source. Scratch tests, employing a diamond stylus with a 200 micro m radius tip, were performed on uncoated and on silver coated alumina. Subsequent surface analysis show that a significant amount of silver remains on the scratched surfaces, even in areas where high stylus load produced severe crack patterns in the ceramic. Friction coefficients were lowered during the scratch tests on the coated alumina indicating that this modification of the ion planting process should be useful for applying lubricating films of soft metals to electrical insulating materials. The very good throwing power of SCIP also strongly suggests general applicability of this process in other areas of technology, e.g., electronics, in addition to tribology.

Ion plating studies for high temperature applications

NASA Technical Reports Server (NTRS)

Davis, J. H.

1980-01-01

An experimental project was undertaken to ion plate, by electron beam evaporation, Al films onto 4340 steel substrates using (and at the time troubleshooting) the custom built V.T.A. 7375 electron beam ion plating system. A careful recent literature and commercial vendor survey indicates possible means of improving the trouble plagued V.T.A. system.

CALUTRON RECEIVER

DOEpatents

York, H.F.

1959-07-01

A receiver construction is presented for calutrons having two or more ion sources and an individual receiver unit for each source. Design requirements dictate that the face plate defining the receiver entrance slots be placed at an angle to the approaching beam, which means that ions striking the face plate are likely to be scattcred into the entrance slots of other receivers. According to the present invention, the face plate has a surface provided with parallel ridges so disposed that one side only of each ridge's exposed directly to the ion beam. The scattered ions are directed away from adjacent receivers by the ridges on the lace plate.

CALUTRON ION SOURCE

DOEpatents

Oppenheimer, F.F.

1959-06-01

A shielding arrangement for eliminating oscillating electrons in the ion source region of calutrons is offered. Metal plates are attached to the ion generator so as to intercept the magnetic field between ion generator and accelerating electrode. The oscillating electrons are discharged on the plates. (T.R.H.)

Ion plating technique improves thin film deposition

NASA Technical Reports Server (NTRS)

Mattox, D. M.

1968-01-01

Ion plating technique keeps the substrate surface clean until the film is deposited, allows extensive diffusion and chemical reaction, and joins insoluble or incompatible materials. The technique involves the deposition of ions on the substrate surface while it is being bombarded with inert gas ions.

Aluminum and chromium ion particle studies for enhancement of surface properties

NASA Technical Reports Server (NTRS)

1982-01-01

An experimental project was undertaken which produced ion plated coatings on steel substrates. About twenty tensile samples of 4340 steel were ion plated in the Denton system with aluminum using resistance heating evaporation boats. In the V.T.A. 7375 system, ten samples were chromium ion plated; four on 4340 steel disks and the other six onto 440-C stainless steel rods for roller bearing wear improvement testing. Each of the samples was plated on a separate run to correlate the film parameters with the run parameters. Some of the chromium literature was reviewed, and improvements to the vacuum system were made.

Arcing in space structures in low Earth orbit

NASA Technical Reports Server (NTRS)

Upschulte, B. L.; Marinelli, W. J.; Weyl, G.; Carleton, K. L.

1992-01-01

This report describes results of an experimental and theoretical program to investigate arcing of structures containing dielectric and conducting materials when they are biased negatively with respect to a plasma. An argon ion source generated Ar(+) ions of directed energy 20 to 40 eV and density approximately 10(exp 7) cm(exp -3) that impinged upon samples containing a dielectric material on top of a negatively biased Kovar plate. Arcing events were studied for bias voltages between -300 and -1000V with respect to the ion beam. The samples were Dow Corning 93-500 adhesive on Kovar, fused silica cover slips bonded on Kovar, and silicon solar cells mounted on Kovar. Measurements of discharge current, Kovar plate voltage, and radiation from the arc versus time were carried out. Microsecond duration exposure images and optical spectra in the 0.24 to 0.40 micron band were also acquired during arcing events. Arcing events were found to be associated with exposed adhesive and means were found to eliminate arcing altogether. The charging of a silica cover plate and the fields around the plate were calculated using a particle-in-cell code. Models were developed to explain the ignition of the arc and the physical processes occurring during the discharge.

Simultaneous removal of arsenite and fluoride via an integrated electro-oxidation and electrocoagulation process.

PubMed

Zhao, Xu; Zhang, Baofeng; Liu, Huijuan; Qu, Jiuhui

2011-04-01

An integrated electro-oxidation and electrocoagulation system was designed and used to remove As(III) and F(-) ions from water simultaneously. Dimensionally stable anodes (DSA), Fe electrodes, and Al electrodes were combined into an electrochemical system. Two pieces of DSA electrodes were assigned as the outside of the Fe and Al electrodes and were directly connected to the power supply as anode and cathode, respectively. The Fe and Al ions were generated by electro-induced process simultaneously. Subsequently, hydroxides of Fe and Al were formed. Arsenic ions are mainly removed by iron hydroxides and F(-) ions are mainly removed by the Al oxides. At the initial concentration of 1.0 mg L(-1), most of As(III) was transferred into As(V) within 40 min at current density of 4 mA cm(-2), whereas F(-) ions can be efficiently removed simultaneously. The effect of the ratio of Fe and Al plate electrodes and current density on the removal of As(III) and F(-) was investigated. With one piece of Fe plate electrode and three pieces of Al plate electrodes, it is observed that As(III) with concentration of 1 mg L(-1) and F(-) with concentration of 4.5 mg L(-1) can be removed and their final concentrations were below the values of 10 μg L(-1) and 1.0 mg L(-1), respectively within 40 min. Removal efficiency of As(III) increases with the increase of solution pH. However, in the pH range of 6-7, removal efficiency of F(-) is the largest. Copyright © 2011 Elsevier Ltd. All rights reserved.

Development efforts to improve curved-channel microchannel plates

NASA Technical Reports Server (NTRS)

Corbett, M. B.; Feller, W. B.; Laprade, B. N.; Cochran, R.; Bybee, R.; Danks, A.; Joseph, C.

1993-01-01

Curved-channel microchannel plate (C-plate) improvements resulting from an ongoing NASA STIS microchannel plate (MCP) development program are described. Performance limitations of previous C-plates led to a development program in support of the STIS MAMA UV photon counter, a second generation instrument on the Hubble Space Telescope. C-plate gain, quantum detection efficiency, dark noise, and imaging distortion, which are influenced by channel curvature non-uniformities, have all been improved through use of a new centrifuge fabrication technique. This technique will be described, along with efforts to improve older, more conventional shearing methods. Process optimization methods used to attain targeted C-plate performance goals will be briefly characterized. Newly developed diagnostic measurement techniques to study image distortion, gain uniformity, input bias angle, channel curvature, and ion feedback, will be described. Performance characteristics and initial test results of the improved C-plates will be reported. Future work and applications will also be discussed.

Experimental Observation of the Effects of Translational and Rotational Electrode Misalignment on a Planar Linear Ion Trap Mass Spectrometer

NASA Astrophysics Data System (ADS)

Tian, Yuan; Decker, Trevor K.; McClellan, Joshua S.; Wu, Qinghao; De la Cruz, Abraham; Hawkins, Aaron R.; Austin, Daniel E.

2018-04-01

The performance of miniaturized ion trap mass analyzers is limited, in part, by the accuracy with which electrodes can be fabricated and positioned relative to each other. Alignment of plates in a two-plate planar LIT is ideal to characterize misalignment effects, as it represents the simplest possible case, having only six degrees of freedom (DOF) (three translational and three rotational). High-precision motorized actuators were used to vary the alignment between the two ion trap plates in five DOFs—x, y, z, pitch, and yaw. A comparison between the experiment and previous simulations shows reasonable agreement. Pitch, or the degree to which the plates are parallel along the axial direction, has the largest and sharpest impact to resolving power, with resolving power dropping noticeably with pitch misalignment of a fraction of a degree. Lateral displacement (x) and yaw (rotation of one plate, but plates remain parallel) both have a strong impact on ion ejection efficiency, but little effect on resolving power. The effects of plate spacing (y-displacement) on both resolving power and ion ejection efficiency are attributable to higher-order terms in the trapping field. Varying the DC (axial) trapping potential can elucidate the effects where more misalignments in more than one DOF affect performance. Implications of these results for miniaturized ion traps are discussed. [Figure not available: see fulltext.

Optical and electronic properties of sub-surface conducting layers in diamond created by MeV B-implantation at elevated temperatures

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

Willems van Beveren, L. H., E-mail: laurensw@unimelb.edu.au; Bowers, H.; Ganesan, K.

2016-06-14

Boron implantation with in-situ dynamic annealing is used to produce highly conductive sub-surface layers in type IIa (100) diamond plates for the search of a superconducting phase transition. Here, we demonstrate that high-fluence MeV ion-implantation, at elevated temperatures avoids graphitization and can be used to achieve doping densities of 6 at. %. In order to quantify the diamond crystal damage associated with implantation Raman spectroscopy was performed, demonstrating high temperature annealing recovers the lattice. Additionally, low-temperature electronic transport measurements show evidence of charge carrier densities close to the metal-insulator-transition. After electronic characterization, secondary ion mass spectrometry was performed to mapmore » out the ion profile of the implanted plates. The analysis shows close agreement with the simulated ion-profile assuming scaling factors that take into account an average change in diamond density due to device fabrication. Finally, the data show that boron diffusion is negligible during the high temperature annealing process.« less

Ion plated gold films: Properties, tribological behavior and performance

NASA Technical Reports Server (NTRS)

Spalvins, Talivaldis

1987-01-01

The glow discharge energizing favorably modifies and controls the coating/substrate adherence and the nucleation and growth sequence of ion plated gold films. As a result the adherence, coherence, internal stresses, and morphology of the films are significantly improved. Gold ion plated films because of their graded coating/substrate interface and fine uniform densely packed microstructure not only improve the tribological properties but also induce a surface strengthening effect which improves the mechanical properties such as yield, tensile, and fatigue strength. Consequently significant improvements in the tribological performance of ion plated gold films as compared to vapor deposited gold films are shown in terms of decreased friction/wear and prolonged endurance life.

Rolling contact fatigue life of chromium ion plated 440C bearing steel

NASA Technical Reports Server (NTRS)

Bhat, B. N.; Davis, J. H.

1985-01-01

Rolling contact fatigue (RCF) test specimens of heat treated 440C bearing steel were chromium ion plated in thicknesses from 0.1 to 8.0 micron and tested in RCF tester using 700 ksi maximum Hertzian stress. Heavy coatings, greater than about 5 micron in thickness, peeled off or spalled readily, whereas thin coatings, less than 3 micron thick, were tenacious and did not come off. Furthermore, significant improvement in RCF life was obtained with thin chromium ion plated test specimens. The average increase in B10 life was 75% compared with unplated 440C. These preliminary results indicate that ion plating is a promising way to improve bearing life.

Calibration of BAS-TR image plate response to high energy (3-300 MeV) carbon ions

NASA Astrophysics Data System (ADS)

Doria, D.; Kar, S.; Ahmed, H.; Alejo, A.; Fernandez, J.; Cerchez, M.; Gray, R. J.; Hanton, F.; MacLellan, D. A.; McKenna, P.; Najmudin, Z.; Neely, D.; Romagnani, L.; Ruiz, J. A.; Sarri, G.; Scullion, C.; Streeter, M.; Swantusch, M.; Willi, O.; Zepf, M.; Borghesi, M.

2015-12-01

The paper presents the calibration of Fuji BAS-TR image plate (IP) response to high energy carbon ions of different charge states by employing an intense laser-driven ion source, which allowed access to carbon energies up to 270 MeV. The calibration method consists of employing a Thomson parabola spectrometer to separate and spectrally resolve different ion species, and a slotted CR-39 solid state detector overlayed onto an image plate for an absolute calibration of the IP signal. An empirical response function was obtained which can be reasonably extrapolated to higher ion energies. The experimental data also show that the IP response is independent of ion charge states.

Calibration of BAS-TR image plate response to high energy (3-300 MeV) carbon ions.

PubMed

Doria, D; Kar, S; Ahmed, H; Alejo, A; Fernandez, J; Cerchez, M; Gray, R J; Hanton, F; MacLellan, D A; McKenna, P; Najmudin, Z; Neely, D; Romagnani, L; Ruiz, J A; Sarri, G; Scullion, C; Streeter, M; Swantusch, M; Willi, O; Zepf, M; Borghesi, M

2015-12-01

The paper presents the calibration of Fuji BAS-TR image plate (IP) response to high energy carbon ions of different charge states by employing an intense laser-driven ion source, which allowed access to carbon energies up to 270 MeV. The calibration method consists of employing a Thomson parabola spectrometer to separate and spectrally resolve different ion species, and a slotted CR-39 solid state detector overlayed onto an image plate for an absolute calibration of the IP signal. An empirical response function was obtained which can be reasonably extrapolated to higher ion energies. The experimental data also show that the IP response is independent of ion charge states.

Low pressure spark gap triggered by an ion diode

DOEpatents

Prono, Daniel S.

1985-01-01

Spark gap apparatus for use as an electric switch operating at high voltage, high current and high repetition rate. Mounted inside a housing are an anode, cathode and ion plate. An ionizable fluid is pumped through the chamber of the housing. A pulse of current to the ion plate causes ions to be emitted by the ion plate, which ions move into and ionize the fluid. Electric current supplied to the anode discharges through the ionized fluid and flows to the cathode. Current stops flowing when the current source has been drained. The ionized fluid recombines into its initial dielectric ionizable state. The switch is now open and ready for another cycle.

Low-pressure spark gap triggered by an ion diode

DOEpatents

Prono, D.S.

1982-08-31

Spark gap apparatus for use as an electric switch operating at high voltage, high current and high repetition rate. Mounted inside a housing are an anode, cathode and ion plate. An ionizable fluid is pumped through the chamber of the housing. A pulse of current to the ion plate causes ions to be emitted by the ion plate, which ions move into and ionize the fluid. Electric current supplied to the anode discharges through the ionized fluid and flows to the cathode. Current stops flowing when the current source has been drained. The ionized fluid recombines into its initial dielectric ionizable state. The switch is now open and ready for another cycle.

Alloy vapor deposition using ion plating and flash evaporation

NASA Technical Reports Server (NTRS)

Spalvins, T.

1971-01-01

Method extends scope of ion plating technique to include deposition of alloy films without changing composition of plating alloy. Coatings flow with specimen material without chipping or peeling. Technique is most effective vacuum deposition method for depositing alloys for strong and lasting adherence.

Preparation of polyacrylonitrile nanofibrous membrane for fabrication of separator of lithium ion batteries

NASA Astrophysics Data System (ADS)

Arifeen, W. U.; Dong, T.; Kurniawan, R.; Ko, T. J.

2018-03-01

In this paper, the manufacturing process and morphology of nano fibrous membranes are discussed. These membranes are explored as separators in rechargeable lithium ion batteries. The function of separator is to allow the flow of ions while protecting the physical contact between positive and negative electrode. Therefore, the porosity, mechanical strength and thermal stability of separators possess significant importance. The separators are manufactured by electrospinning process and later the morphology is studied with the help of scanning electron microscope (SEM) images. The separator is prepared by polyacrylonitrile (PAN) and then exposed to the hot plate. The uniform, continuous and dense nano fibrous membrane is prepared with the help of electrospinning process providing the prevention of physical contact between electrode and stable enough to work in high temperatures leading to high performance lithium ion batteries separators.

DUAL HEATED ION SOURCE STRUCTURE HAVING ARC SHIFTING MEANS

DOEpatents

Lawrence, E.O.

1959-04-14

An ion source is presented for calutrons, particularly an electrode arrangement for the ion generator of a calutron ion source. The ion source arc chamber is heated and an exit opening with thermally conductive plates defines the margins of the opening. These plates are electrically insulated from the body of the ion source and are connected to a suitable source of voltage to serve as electrodes for shaping the ion beam egressing from the arc chamber.

Industrial potential, uses, and performance of sputtered and ion plated films

NASA Technical Reports Server (NTRS)

Spalvins, T.

1979-01-01

The sputtering and ion plating technology is reviewed in terms of their potential, uses and performance. It offers the greatest flexibility in coating preparation, since coatings can be tailored in any preferred chemical combination, and graded type interfaces (ceramic to metal seals) can be formed. Sputtered and ion plated film characteristics such as the degree of adherence, coherence and morphological growth which contribute to film performance and reliability are described and illustrated as used in practice. It is concluded that the potential future of sputtered and ion plated films for industrial applications will depend primarily upon greater comprehension of materials selection, possible elimination of restrictions for coating/substrate combinations and the awareness of utilizing the proper deposition parameters.

Dependence of ion beam current on position of mobile plate tuner in multi-frequencies microwaves electron cyclotron resonance ion source

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

Kurisu, Yosuke; Kiriyama, Ryutaro; Takenaka, Tomoya

2012-02-15

We are constructing a tandem-type electron cyclotron resonance ion source (ECRIS). The first stage of this can supply 2.45 GHz and 11-13 GHz microwaves to plasma chamber individually and simultaneously. We optimize the beam current I{sub FC} by the mobile plate tuner. The I{sub FC} is affected by the position of the mobile plate tuner in the chamber as like a circular cavity resonator. We aim to clarify the relation between the I{sub FC} and the ion saturation current in the ECRIS against the position of the mobile plate tuner. We obtained the result that the variation of the plasmamore » density contributes largely to the variation of the I{sub FC} when we change the position of the mobile plate tuner.« less

A FRET system built on quartz plate as a ratiometric fluorescence sensor for mercury ions in water.

PubMed

Liu, Baoyu; Zeng, Fang; Liu, Yan; Wu, Shuizhu

2012-04-07

Due to the hazardous nature of mercury ions, the development of a cost effective, sensitive and field-portable sensor is of high significance for both industry and civilian use. In this work, a FRET-based ratiometric sensor for detecting mercury ions in water was fabricated by depositing a multilayered silica structure on a quartz plate. For the preparation of the film-based sensor, a silica support layer was first deposited on the quartz plate by using the sol-gel spin-coating procedure, and three ultrathin functional layers (donor, spacer and receptor) were then deposited on the support layer by dip-coating in a stepwise manner in toluene solution. As the film-based sensor was placed into an aqueous solution of Hg(2+), the non-fluorescent receptor (a spirolactam rhodamine derivative) on the film surface could form a complex with the mercury ion and act as the acceptor of the energy transfer. Upon excitation, the donor (a nitrobenzoxadiazolyl derivative, NBD) could transfer its excited energy from the donor layer to the acceptor on the film surface via the 'through space' energy transfer process, thus realizing the FRET-based ratiometric sensing for mercury ions. The sensor can selectively detect Hg(2+) in water with the detection limit of 1 μM. This solid film sensor is capable of being easily-portable and visualized detection. This strategy may offer new approaches for constructing other FRET-based solid-state devices.

Designing dual-plate meteoroid shields: A new analysis

NASA Technical Reports Server (NTRS)

Swift, H. F.; Bamford, R.; Chen, R.

1982-01-01

Physics governing ultrahigh velocity impacts onto dual-plate meteor armor is discussed. Meteoroid shield design methodologies are considered: failure mechanisms, qualitative features of effective meteoroid shield designs, evaluating/processing meteoroid threat models, and quantitative techniques for optimizing effective meteoroid shield designs. Related investigations are included: use of Kevlar cloth/epoxy panels in meteoroid shields for the Halley's Comet intercept vehicle, mirror exposure dynamics, and evaluation of ion fields produced around the Halley Intercept Mission vehicle by meteoroid impacts.

Evaluation of stabilization techniques for ion implant processing

NASA Astrophysics Data System (ADS)

Ross, Matthew F.; Wong, Selmer S.; Minter, Jason P.; Marlowe, Trey; Narcy, Mark E.; Livesay, William R.

1999-06-01

With the integration of high current ion implant processing into volume CMOS manufacturing, the need for photoresist stabilization to achieve a stable ion implant process is critical. This study compares electron beam stabilization, a non-thermal process, with more traditional thermal stabilization techniques such as hot plate baking and vacuum oven processing. The electron beam processing is carried out in a flood exposure system with no active heating of the wafer. These stabilization techniques are applied to typical ion implant processes that might be found in a CMOS production process flow. The stabilization processes are applied to a 1.1 micrometers thick PFI-38A i-line photoresist film prior to ion implant processing. Post stabilization CD variation is detailed with respect to wall slope and feature integrity. SEM photographs detail the effects of the stabilization technique on photoresist features. The thermal stability of the photoresist is shown for different levels of stabilization and post stabilization thermal cycling. Thermal flow stability of the photoresist is detailed via SEM photographs. A significant improvement in thermal stability is achieved with the electron beam process, such that photoresist features are stable to temperatures in excess of 200 degrees C. Ion implant processing parameters are evaluated and compared for the different stabilization methods. Ion implant system end-station chamber pressure is detailed as a function of ion implant process and stabilization condition. The ion implant process conditions are detailed for varying factors such as ion current, energy, and total dose. A reduction in the ion implant systems end-station chamber pressure is achieved with the electron beam stabilization process over the other techniques considered. This reduction in end-station chamber pressure is shown to provide a reduction in total process time for a given ion implant dose. Improvements in the ion implant process are detailed across several combinations of current and energy.

CALUTRON ASSEMBLING AND DISASSEMBLING MEANS

DOEpatents

Andrews, R.E.; Thornton, J.

1959-01-27

This patent relates to the assembling and disassembling of a calutron and, more specifically describes a calutron having the ion separating mechanism carried by a fuce plate removably secured to the tank. When it is desired to withdraw the ion separating mechanism from the tank, a motor is energized and a carriage attached through a bracket to the fuce plate is driven along a track. The face plate moves out from the tank in substantially a linear direction, preventing injury to the ion separating mechanism.

Obtaining accurate amounts of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, Mark W.; George, William A.

1987-01-01

A process for obtaining pre-determined, accurate rate amounts of mercury. In one embodiment, predetermined, precise amounts of Hg are separated from HgO and plated onto a cathode wire. The method for doing this involves dissolving a precise amount of HgO which corresponds to a pre-determined amount of Hg desired in an electrolyte solution comprised of glacial acetic acid and H.sub.2 O. The mercuric ions are then electrolytically reduced and plated onto a cathode producing the required pre-determined quantity of Hg. In another embodiment, pre-determined, precise amounts of Hg are obtained from Hg.sub.2 Cl.sub.2. The method for doing this involves dissolving a precise amount of Hg.sub.2 Cl.sub.2 in an electrolyte solution comprised of concentrated HCl and H.sub.2 O. The mercurous ions in solution are then electrolytically reduced and plated onto a cathode wire producing the required, pre-determined quantity of Hg.

Obtaining accurate amounts of mercury from mercury compounds via electrolytic methods

DOEpatents

Grossman, M.W.; George, W.A.

1987-07-07

A process is described for obtaining pre-determined, accurate rate amounts of mercury. In one embodiment, predetermined, precise amounts of Hg are separated from HgO and plated onto a cathode wire. The method for doing this involves dissolving a precise amount of HgO which corresponds to a pre-determined amount of Hg desired in an electrolyte solution comprised of glacial acetic acid and H[sub 2]O. The mercuric ions are then electrolytically reduced and plated onto a cathode producing the required pre-determined quantity of Hg. In another embodiment, pre-determined, precise amounts of Hg are obtained from Hg[sub 2]Cl[sub 2]. The method for doing this involves dissolving a precise amount of Hg[sub 2]Cl[sub 2] in an electrolyte solution comprised of concentrated HCl and H[sub 2]O. The mercurous ions in solution are then electrolytically reduced and plated onto a cathode wire producing the required, pre-determined quantity of Hg. 1 fig.

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

Elizondo-Decanini, Juan M.

Short pulse neutron generators are described herein. In a general embodiment, the short pulse neutron generator includes a Blumlein structure. The Blumlein structure includes a first conductive plate, a second conductive plate, a third conductive plate, at least one of an inductor or a resistor, a switch, and a dielectric material. The first conductive plate is positioned relative to the second conductive plate such that a gap separates these plates. A vacuum chamber is positioned in the gap, and an ion source is positioned to emit ions in the vacuum chamber. The third conductive plate is electrically grounded, and themore » switch is operable to electrically connect and disconnect the second conductive plate and the third conductive plate. The at least one of the resistor or the inductor is coupled to the first conductive plate and the second conductive plate.« less

Transition from moving to stationary double layers in a single-ended Q machine

NASA Technical Reports Server (NTRS)

Song, Bin; Merlino, R. L.; D'Angelo, N.

1990-01-01

Large-amplitude (less than about 100 percent) relaxation oscillations in the plasma potential are known to be generated when the cold endplate of a single-ended Q machine is biased positively. These oscillations are associated with double layers that form near the hot plate (plasma source) and travel toward the endplate at about the ion-acoustic velocity. At the endplate they dissolve and then form again near the hot plate, the entire process repeating itself in a regular manner. By admitting a sufficient amount of neutral gas into the system, the moving double layers were slowed down and eventually stopped. The production of stationary double layers requires an ion source on the high-potential side of the double layers. These ions are provided by ionization of the neutral gas by electrons that are accelerated through the double layer. The dependence of the critical neutral gas pressure required for stationary double-layer formation on endplate voltage, magnetic field strength, and neutral atom mass has been examined. These results are discussed in terms of a simple model of ion production and loss, including ion losses across the magnetic field.

Sputtering Holes with Ion Beamlets

NASA Technical Reports Server (NTRS)

Byers, D. C.; Banks, B. A.

1974-01-01

Ion beamlets of predetermined configurations are formed by shaped apertures in the screen grid of an ion thruster having a double grid accelerator system. A plate is placed downstream from the screen grid holes and attached to the accelerator grid. When the ion thruster is operated holes having the configuration of the beamlets formed by the screen grid are sputtered through the plate at the accelerator grid.

Improved Miniaturized Linear Ion Trap Mass Spectrometer Using Lithographically Patterned Plates and Tapered Ejection Slit

NASA Astrophysics Data System (ADS)

Tian, Yuan; Decker, Trevor K.; McClellan, Joshua S.; Bennett, Linsey; Li, Ailin; De la Cruz, Abraham; Andrews, Derek; Lammert, Stephen A.; Hawkins, Aaron R.; Austin, Daniel E.

2018-02-01

We present a new two-plate linear ion trap mass spectrometer that overcomes both performance-based and miniaturization-related issues with prior designs. Borosilicate glass substrates are patterned with aluminum electrodes on one side and wire-bonded to printed circuit boards. Ions are trapped in the space between two such plates. Tapered ejection slits in each glass plate eliminate issues with charge build-up within the ejection slit and with blocking of ions that are ejected at off-nominal angles. The tapered slit allows miniaturization of the trap features (electrode size, slit width) needed for further reduction of trap size while allowing the use of substrates that are still thick enough to provide ruggedness during handling, assembly, and in-field applications. Plate spacing was optimized during operation using a motorized translation stage. A scan rate of 2300 Th/s with a sample mixture of toluene and deuterated toluene (D8) and xylenes (a mixture of o-, m-, p-) showed narrowest peak widths of 0.33 Th (FWHM).

RADIATION MEASURING DEVICES

DOEpatents

Bouricius, G.M.B.; Rusch, G.K.

1960-03-22

A radiation-measuring device is described having an a-c output. The apparatus has a high-energy particle source responsive to radiation flux disposed within a housing having a pair of collector plates. A potential gradient between the source and collector plates causes ions to flow to the plates. By means of electrostatic or magnetic deflection elements connected to an alternating potential, the ions are caused to flow alternately to each of the collector plates causing an a-c signal thereon.

High resolution Thomson Parabola Spectrometer for full spectral capture of multi-species ion beams.

PubMed

Alejo, A; Kar, S; Tebartz, A; Ahmed, H; Astbury, S; Carroll, D C; Ding, J; Doria, D; Higginson, A; McKenna, P; Neumann, N; Scott, G G; Wagner, F; Roth, M; Borghesi, M

2016-08-01

We report on the experimental characterisation of laser-driven ion beams using a Thomson Parabola Spectrometer (TPS) equipped with trapezoidally shaped electric plates, proposed by Gwynne et al. [Rev. Sci. Instrum. 85, 033304 (2014)]. While a pair of extended (30 cm long) electric plates was able to produce a significant increase in the separation between neighbouring ion species at high energies, deploying a trapezoidal design circumvented the spectral clipping at the low energy end of the ion spectra. The shape of the electric plate was chosen carefully considering, for the given spectrometer configuration, the range of detectable ion energies and species. Analytical tracing of the ion parabolas matches closely with the experimental data, which suggests a minimal effect of fringe fields on the escaping ions close to the wedged edge of the electrode. The analytical formulae were derived considering the relativistic correction required for the high energy ions to be characterised using such spectrometer.

High resolution Thomson Parabola Spectrometer for full spectral capture of multi-species ion beams

NASA Astrophysics Data System (ADS)

Alejo, A.; Kar, S.; Tebartz, A.; Ahmed, H.; Astbury, S.; Carroll, D. C.; Ding, J.; Doria, D.; Higginson, A.; McKenna, P.; Neumann, N.; Scott, G. G.; Wagner, F.; Roth, M.; Borghesi, M.

2016-08-01

We report on the experimental characterisation of laser-driven ion beams using a Thomson Parabola Spectrometer (TPS) equipped with trapezoidally shaped electric plates, proposed by Gwynne et al. [Rev. Sci. Instrum. 85, 033304 (2014)]. While a pair of extended (30 cm long) electric plates was able to produce a significant increase in the separation between neighbouring ion species at high energies, deploying a trapezoidal design circumvented the spectral clipping at the low energy end of the ion spectra. The shape of the electric plate was chosen carefully considering, for the given spectrometer configuration, the range of detectable ion energies and species. Analytical tracing of the ion parabolas matches closely with the experimental data, which suggests a minimal effect of fringe fields on the escaping ions close to the wedged edge of the electrode. The analytical formulae were derived considering the relativistic correction required for the high energy ions to be characterised using such spectrometer.

High resolution Thomson Parabola Spectrometer for full spectral capture of multi-species ion beams

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

Alejo, A.; Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.

2016-08-15

We report on the experimental characterisation of laser-driven ion beams using a Thomson Parabola Spectrometer (TPS) equipped with trapezoidally shaped electric plates, proposed by Gwynne et al. [Rev. Sci. Instrum. 85, 033304 (2014)]. While a pair of extended (30 cm long) electric plates was able to produce a significant increase in the separation between neighbouring ion species at high energies, deploying a trapezoidal design circumvented the spectral clipping at the low energy end of the ion spectra. The shape of the electric plate was chosen carefully considering, for the given spectrometer configuration, the range of detectable ion energies and species.more » Analytical tracing of the ion parabolas matches closely with the experimental data, which suggests a minimal effect of fringe fields on the escaping ions close to the wedged edge of the electrode. The analytical formulae were derived considering the relativistic correction required for the high energy ions to be characterised using such spectrometer.« less

Preliminary results with microchannel array plates employing curved microchannels to inhibit ion feedback. [for photon counters

NASA Technical Reports Server (NTRS)

Timothy, J. G.; Bybee, R. L.

1977-01-01

Up to now, microchannel array plates (MCPs) have been constructed with microchannels having a straight geometry and hence have been prone to ion-feedback instabilities at high operating potentials and high ambient pressures. This paper describes the performances of MCPs with curved (J and C configuration) microchannels to inhibit ion feedback. Plates with curved microchannels have demonstrated performances comparable to those of conventional channel electron multipliers with saturated output pulse-height distributions and modal gain values in excess of 10 to the 6th electrons/pulse.

Corrosion-resistant uranium

DOEpatents

Hovis, V.M. Jr.; Pullen, W.C.; Kollie, T.G.; Bell, R.T.

1981-10-21

The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

Corrosion-resistant uranium

DOEpatents

Hovis, Jr., Victor M.; Pullen, William C.; Kollie, Thomas G.; Bell, Richard T.

1983-01-01

The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

Genetic changes in mammalian cells transformed by helium ions

NASA Astrophysics Data System (ADS)

Durante, M.; Grossi, G.; Yang, T. C.; Roots, R.

Midterm Syrian Hamster embryo (SHE) cells were employed to study high LET-radiation induced tumorigenesis. Normal SHE cells (secondary passage) were irradiated with accelerated helium ions at an incident energy of 22 MeV/u (9-10 keV/μm). Transformed clones were isolated after growth in soft agar of cells obtained from the foci of the initial monolayer plated postirradiation. To study the progression process of malignant transformation, the transformed clones were followed by monolayer subculturing for prolonged periods of time. Subsequently, neoplasia tests in nude mice were done. In this work, however, we have focused on karyotypic changes in the banding patterns of the chromosomes during the early part of the progressive process of cell transformation for helium ion-induced transformed cells.

Surface modification by carbon ion implantation for the application of ni-based amorphous alloys as bipolar plate in proton exchange membrane fuel cells

NASA Astrophysics Data System (ADS)

Kim, Min-Uk; Kim, Do-Hyang; Han, Seung-hee; Fleury, Eric; Seok, Hyun-Kwang; Cha, Pil-Ryung; Kim, Yu-Chan

2011-04-01

Ni-based amorphous alloys with surface modification by carbon ion implantation are proposed as an alternative bipolar plate material for polymer electrolyte membrane fuel cells (PEMFCs). Both Ni60Nb20Ti10Zr10 alloys with and without carbon ion implantation have corrosion resistance as good as graphite as well as much lower contact resistance than 316L stainless steel in the PEMFC environment. The formation of conductive surface carbide due to carbon ion implantation results in a decrease in the contact resistance to a level comparable to that of graphite. This combination of excellent properties indicates that carbon ion implanted Ni-based amorphous alloys can be potential candidate materials for bipolar plates in PEMFCs.

Investigation on the Oxidation and Reduction of Titanium in Molten Salt with the Soluble TiC Anode

NASA Astrophysics Data System (ADS)

Wang, Shulan; Wan, Chaopin; Liu, Xuan; Li, Li

2015-12-01

To reveal the oxidation process of titanium from TiC anode and the reduction mechanism of titanium ions in molten NaCl-KCl, the polarization curve of TiC anode in molten NaCl-KCl and cyclic voltammograms of the molten salt after polarization were studied. Investigation on the polarization curve shows that titanium can be oxidized and dissociated from the TiC anode at very low potential. The cyclic voltammograms demonstrated that the reduction reaction of titanium ions in the molten salt is a one-step process. By potentiostatic electrolysis, dendritic titanium is obtained on the steel plate. The work promotes the understanding on the process of electrochemical oxidization/dissociation of titanium from TiC anode and the reduction mechanism of titanium ions in molten salt.

Optical and Scratch Resistant Properties of Diamondlike Carbon Films Deposited with Single and Dual Ion Beams

NASA Technical Reports Server (NTRS)

Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

1993-01-01

Amorphous diamond-like carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance, frictional, and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

Optical and scratch resistant properties of diamondlike carbon films deposited with single and dual ion beams

NASA Technical Reports Server (NTRS)

Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

1993-01-01

Amorphous diamondlike carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance and frictional and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

The new applications of sputtering and ion plating

NASA Technical Reports Server (NTRS)

Spalvins, T.

1977-01-01

The potential industrial applications of sputtering and ion plating are strictly governed by the unique features these methods possess. The outstanding features of each method, the resultant coating characteristics and the various sputtering modes and configurations are discussed. New, more complex coatings and deposits can be developed such as graded composition structures (metal-ceramic seals), laminated and dispersion strengthened composites which improve the mechanical properties and high temperature stability. Specific industrial areas where future effort of sputtering and ion plating will concentrate to develop intricate alloy or compound coatings and solve difficult problem areas are discussed.

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

Wei, Zi-an; Ma, J. X., E-mail: jxma@ustc.edu.cn

Ion sheaths formed in the up- and downstream sides of a negatively biased metal plate/mesh in an ion-beam-background-plasma system were experimentally investigated in a double plasma device. Measured potential profiles near the plate exhibit asymmetric structure, showing thicker sheath in the downstream side. The presence of the ion beam causes the shrink of the sheaths on both sides. The sheath thickness decreases with the increase of beam energy and density. Furthermore, the sheaths near the mesh are substantially thinner than that near the plate because of the partial transmission of the mesh to the ions. In addition, the increase ofmore » neutral gas pressure leads to the reduction of the beam energy and density, resulting in the increase of the sheath thickness.« less

Fiber Optic Couplers.

DTIC Science & Technology

1979-11-01

over a 1 x 4 inch glass plate. A further problem has been that the surface over the ion diffused region is submerged 2 pm below that of the substrate...of varying mask openings (35, 45, 55, 65, 78, 85 pm ). The ion exchange processing time was varied using 20, 25, 35 and 40 minutes. We found that the...pattern is then overcoated with a thick layer of SiO 2 (lO0 pm thick). This thick layer and the SiO 2 substrate thus com- pletely surround the dopant

CALUTRON ASSEMBLING AND DISASSEMBLING APPARATUS

DOEpatents

Andrews, R.E.

1959-01-27

A closure plate assembly is presented for a calutron tank. Due to the size and weight of the calutron tank a special face plate, hinges and latch construction are required. The salient feature of the invention is the provision of a face plate carrying the ion separating niechanism and adapted to close an open side of a calutron tank. A spring-type hinge secured to the face plate at one end prevents injury to the sealing gasket as the face plate is inserted and withdrawn. In additions a hinged support for the face plate comprises readily separable hinge elements, so that the face plate may first be swung outwardly from its operative position far enough to clear the ion separating meehanism carried thereby, and may thereafter be elevated and transported by a convcntional overhead crane.

Coincidence ion imaging with a fast frame camera

NASA Astrophysics Data System (ADS)

Lee, Suk Kyoung; Cudry, Fadia; Lin, Yun Fei; Lingenfelter, Steven; Winney, Alexander H.; Fan, Lin; Li, Wen

2014-12-01

A new time- and position-sensitive particle detection system based on a fast frame CMOS (complementary metal-oxide semiconductors) camera is developed for coincidence ion imaging. The system is composed of four major components: a conventional microchannel plate/phosphor screen ion imager, a fast frame CMOS camera, a single anode photomultiplier tube (PMT), and a high-speed digitizer. The system collects the positional information of ions from a fast frame camera through real-time centroiding while the arrival times are obtained from the timing signal of a PMT processed by a high-speed digitizer. Multi-hit capability is achieved by correlating the intensity of ion spots on each camera frame with the peak heights on the corresponding time-of-flight spectrum of a PMT. Efficient computer algorithms are developed to process camera frames and digitizer traces in real-time at 1 kHz laser repetition rate. We demonstrate the capability of this system by detecting a momentum-matched co-fragments pair (methyl and iodine cations) produced from strong field dissociative double ionization of methyl iodide.

Correlation potential of a test ion near a strongly charged plate.

PubMed

Lu, Bing-Sui; Xing, Xiangjun

2014-03-01

We analytically calculate the correlation potential of a test ion near a strongly charged plate inside a dilute m:-n electrolyte. We do this by calculating the electrostatic Green's function in the presence of a nonlinear background potential, the latter having been obtained using the nonlinear Poisson-Boltzmann theory. We consider the general case where the dielectric constants of the plate and the electrolyte are distinct. The following generic results emerge from our analyses: (1) If the distance to the plate Δz is much larger than a Gouy-Chapman length, the plate surface will behave effectively as an infinitely charged surface, and the dielectric constant of the plate effectively plays no role. (2) If Δz is larger than a Gouy-Chapman length but shorter than a Debye length, the correlation potential can be interpreted in terms of an image charge that is three times larger than the source charge. This behavior is independent of the valences of the ions. (3) The Green's function vanishes inside the plate if the surface charge density is infinitely large; hence the electrostatic potential is constant there. In this respect, a strongly charged plate behaves like a conductor plate. (4) If Δz is smaller than a Gouy-Chapman length, the correlation potential is dominated by the conventional image charge due to the dielectric discontinuity at the interface. (5) If Δz is larger than a Debye length, the leading order behavior of the correlation potential will depend on the valences of the ions in the electrolyte. Furthermore, inside an asymmetric electrolyte, the correlation potential is singly screened, i.e., it undergoes exponential decay with a decay width equal to the Debye length.

Electrodeposition of Isolated Platinum Atoms and Clusters on Bismuth-Characterization and Electrocatalysis.

PubMed

Zhou, Min; Dick, Jeffrey E; Bard, Allen J

2017-12-06

We describe a method for the electrodeposition of an isolated single Pt atom or small cluster, up to 9 atoms, on a bismuth ultramicroelectrode (UME). This deposition was immediately followed by electrochemical characterization via the hydrogen evolution reaction (HER) that occurs readily on the electrodeposited Pt but not on Bi. The observed voltammetric current plateau, even for a single atom, which behaves as an electrode, allows the estimation of deposit size. Pt was plated from solutions of femtomolar PtCl 6 2- , which allowed precise control of the arrival of ions and thus the plating rate on the Bi UME, to one ion every few seconds. This allowed the atom-by-atom fabrication of isolated platinum deposits, ranging from single atoms to 9-atom clusters. The limiting currents in voltammetry gave the size and number of atoms of the clusters. Given the stochasticity of the plating process, we show that the number of atoms plated over a given time (10 and 20 s) follows a Poisson distribution. Taking the potential at a certain current density as a measure of the relative rate of the HER, we found that the potential shifted positively as the size increased, with single atoms showing the largest overpotentials compared to bulk Pt.

Deionization and desalination using electrostatic ion pumping

DOEpatents

Bourcier, William L.; Aines, Roger D.; Haslam, Jeffery J.; Schaldach, Charlene M.; O& #x27; Brien, Kevin C.; Cussler, Edward

2013-06-11

The present invention provides a new method and apparatus/system for purifying ionic solutions, such as, for example, desalinating water, using engineered charged surfaces to sorb ions from such solutions. Surface charge is applied externally, and is synchronized with oscillatory fluid movements between substantially parallel charged plates. Ions are held in place during fluid movement in one direction (because they are held in the electrical double layer), and released for transport during fluid movement in the opposite direction by removing the applied electric field. In this way the ions, such as salt, are "ratcheted" across the charged surface from the feed side to the concentrate side. The process itself is very simple and involves only pumps, charged surfaces, and manifolds for fluid collection.

Deionization and desalination using electrostatic ion pumping

DOEpatents

Bourcier, William L [Livermore, CA; Aines, Roger D [Livermore, CA; Haslam, Jeffery J [Livermore, CA; Schaldach, Charlene M [Pleasanton, CA; O'Brien, Kevin C [San Ramon, CA; Cussler, Edward [Edina, MN

2011-07-19

The present invention provides a new method and apparatus/system for purifying ionic solutions, such as, for example, desalinating water, using engineered charged surfaces to sorb ions from such solutions. Surface charge is applied externally, and is synchronized with oscillatory fluid movements between substantially parallel charged plates. Ions are held in place during fluid movement in one direction (because they are held in the electrical double layer), and released for transport during fluid movement in the opposite direction by removing the applied electric field. In this way the ions, such as salt, are "ratcheted" across the charged surface from the feed side to the concentrate side. The process itself is very simple and involves only pumps, charged surfaces, and manifolds for fluid collection.

The X-ray photoelectron spectroscopy depth profiling and tribological characterization of ion-plated gold on various metals

NASA Technical Reports Server (NTRS)

Miyoshi, K.; Spalvins, T.; Buckley, D. H.

1983-01-01

For the case of ion-plated gold, the graded interface between gold and a nickel substrate and a nickel substrate, such tribological properties as friction and microhardness are examined by means of X-ray photoelectron spectroscopy analysis and depth profiling. Sliding was conducted against SiC pins in both the adhesive process, where friction arises from adhesion between sliding surfaces, and abrasion, in which friction is due to pin indentation and groove-plowing. Both types of friction are influenced by coating depth, but with opposite trends: the graded interface exhibited the highest adhesion, but the lowest abrasion. The coefficient of friction due to abrasion is inversely related to hardness. Graded interface microhardness values are found to be the highest, due to an alloying effect. There is almost no interface gradation between the vapor-deposited gold film and the substrate.

Photosensitivity enhancement of PLZT ceramics by positive ion implantation

DOEpatents

Land, Cecil E.; Peercy, Paul S.

1983-01-01

The photosensitivity of lead lanthanum zirconate titanate (PLZT) ceramic material used in high resolution, high contrast, and non-volatile photoferroelectric image storage and display devices is enhanced significantly by positive ion implantation of the PLZT near its surface. Implanted ions include H.sup.+, He.sup.+, Ne.sup.+, Ar.sup.+, as well as chemically reactive ions from Fe, Cr, and Al. The positive ion implantation advantageously serves to shift the absorption characteristics of the PLZT material from near-UV light to visible light. As a result, photosensitivity enhancement is such that the positive ion implanted PLZT plate is sensitive even to sunlight and conventional room lighting, such as fluorescent and incandescent light sources. The method disclosed includes exposing the PLZT plate to the positive ions at sufficient density, from 1.times.10.sup.12 to 1.times.10.sup.17, and with sufficient energy, from 100 to 500 KeV, to provide photosensitivity enhancement. The PLZT material may have a lanthanum content ranging from 5 to 10%, a lead zirconate content of 62 to 70 mole %, and a lead titanate content of 38 to 30%. The ions are implanted at a depth of 0.1 to 2 microns below the surface of the PLZT plate.

Development towards a fast ion loss detector for the reversed field pinch.

PubMed

Bonofiglo, P J; Anderson, J K; Almagri, A F; Kim, J; Clark, J; Capecchi, W; Sears, S H; Egedal, J

2016-11-01

A fast ion loss detector has been constructed and implemented on the Madison Symmetric Torus (MST) to investigate energetic ion losses and transport due to energetic particle and MHD instabilities. The detector discriminates particle orbits solely on pitch and consists of two thin-foil, particle collecting plates that are symmetric with respect to the device aperture. One plate collects fast ion signal, while the second aids in the minimization of background and noise effects. Initial measurements are reported along with suggestions for the next design phase of the detector.

Dielectric particle injector for material processing

NASA Technical Reports Server (NTRS)

Leung, Philip L. (Inventor)

1992-01-01

A device for use as an electrostatic particle or droplet injector is disclosed which is capable of injecting dielectric particles or droplets. The device operates by first charging the dielectric particles or droplets using ultraviolet light induced photoelectrons from a low work function material plate supporting the dielectric particles or droplets, and then ejecting the charged particles or droplets from the plate by utilizing an electrostatic force. The ejected particles or droplets are mostly negatively charged in the preferred embodiment; however, in an alternate embodiment, an ion source is used instead of ultraviolet light to eject positively charged dielectric particles or droplets.

Means for obtaining a metal ion beam from a heavy-ion cyclotron source

DOEpatents

Hudson, E.D.; Mallory, M.L.

1975-08-01

A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

Coatings for wear and lubrication

NASA Technical Reports Server (NTRS)

Spalvins, T.

1978-01-01

Recent advances in the tribological uses of rf-sputtered and ion plated films of solid film lubricants (laminar solids, soft metals, organic polymers) and wear resistant refractory compounds (carbides, nitrides, silicides) are reviewed. The sputtering and ion plating potentials and the corresponding coatings formed were evaluated relative to the friction coefficient, wear endurance life and mechanical properties. The tribological and mechanical properties for each kind of film are discussed in terms of film adherence, coherence, density, grain size, morphology, internal stresses, thickness, and substrate conditions such as temperature, topography, chemistry and dc-biasing. The ion plated metallic films in addition to improved tribological properties also have better mechanical properties such as tensile strength and fatigue life.

Ion guiding accompanied by formation of neutrals in polyethylene terephthalate polymer nanocapillaries: Further insight into a self-organizing process

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

Juhasz, Z.; Sulik, B.; Racz, R.

2010-12-15

A relatively large yield of neutralized atoms was observed when 3 keV Ar{sup 7+} ions were guided trough polyethylene terephthalate nanocapillaries. Time and deposited-charge dependence of the angular distribution of both the guided ions and the neutrals was measured simultaneously using a two-dimensional multichannel plate detector. The yield of neutrals increased significantly faster than that of guided ions and saturated typically at a few percent level. In accordance with earlier observations, both the yield and the mean emission angle of the guided ions exhibited strong oscillations. For the atoms, the equilibrium was achieved not only faster, but also without significantmore » oscillations in yield and angular position. A phase analysis of these time dependencies provides insight into the dynamic features of the self-organizing mechanisms, which leads to ion guiding in insulating nanocapillaries.« less

Gated charged-particle trap

DOEpatents

Benner, W.H.

1999-03-09

The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector. 5 figs.

Harmonic generation and parametric decay in the ion cyclotron frequency range

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

Skiff, F.N.; Wong, K.L.; Ono, M.

1984-06-01

Harmonic generation and parametric decay are examined in a toroidal ACT-I plasma using electrostatic plate antennas. The harmonic generation, which is consistent with sheath rectification, is sufficiently strong that the nonlinearly generated harmonic modes themselves decay parametrically. Resonant and nonresonant parametric decay of the second harmonic are observed and compared with uniform pump theory. Resonant decay of lower hybrid waves into lower hybrid waves and slow ion cyclotron waves is seen for the first time. Surprisingly, the decay processes are nonlinearly saturated, indicating absolute instability.

Gaseous phase ion detection method based on laser-induced fluorescence for ion mobility spectrometer

NASA Astrophysics Data System (ADS)

Guo, Kaitai; Ni, Kai; Ou, Guangli; Zhang, Xiaoguo; Yu, Quan; Qian, Xiang; Wang, Xiaohao

2015-08-01

Ion mobility spectrometry (IMS) is widely used in the field of chemical composition analysis. Faraday cup is the most classical method to detect ions for IMS in the atmospheric pressure. However, the performance of Faraday plate was limited by many kinds of factors, including interfering electromagnetic waves, thermal(Johnson) noise, induced current , gain bandwidth product, etc. There is a theoretical limit in detection of ions at ambient condition which is approximately 106 ions per second. In this paper, we introduced a novel way using laser-induced fluorescence (LIF) to bypass the limitation of Faraday plate. Fluorescent ions which were selected by IMS get excited when they fly through the laser excitation area. The fluorescence emitted by the excited ions was captured exponentially and amplified through proper optoelectronic system. Rhodamine 6G (R6G) was selected as the fluorochrome for the reason that excitation wavelength, emission wavelength, and fluorescence quantum yield were more appropriate than others. An orthometric light path is designed to eliminate the adverse impact which was caused by induced laser. The experiment result shows that a fluorescence signal from the sample ions of the IMS could be observed. Compared with Faraday plate, the LIF-IMS may find a potential application in more system at the atmosphere condition.

Preparation of dumbbell manganese dioxide/gelatin composites and their application in the removal of lead and cadmium ions.

PubMed

Wang, Xiu; Huang, Kai; Chen, Ying; Liu, Jiafa; Chen, Shan; Cao, Jianlei; Mei, Surong; Zhou, Yikai; Jing, Tao

2018-05-15

The nano-sized sorbents restrict their practical application in flow-through system due to excessive pressure. In this study, dumbbell MnO 2 /gelatin composites were synthesized based on the protein-assisted synthesis technology. Then they were immobilized on the amino-modified polymethyl methacrylate (PMMA) plate. SEM, TEM, XRD, XPS and FT-IR were employed to study the surface properties and the adsorption mechanism of MnO 2 /gelatin composites. Adsorption experiments for Pb(II) and Cd(II) ions were performed to study the adsorption isotherms, kinetics, and thermodynamics as well as the influencing factors. The maximum adsorption capacities of Pb(II) and Cd(II) ions were 318.7 mg g -1 and 105.1 mg g -1 respectively. The adsorption process met the pseudo-second-order kinetic model. Subsequently, MnO 2 /gelatin composites modified plates were used to remove the heavy metal ions in surface water and wastewater samples. The removal efficiencies of Pb(II) ion was changed from 83% (wastewater) to 100% (surface water), when the initial concentration was 10 mg L -1 . This device exhibited great application prospect in the removal of heavy metals taking advantage of its high removal efficiency, excellent stability and reusability and ease of operation. Copyright © 2018 Elsevier B.V. All rights reserved.

Analysis of in vivo corrosion of 316L stainless steel posterior thoracolumbar plate systems: a retrieval study.

PubMed

Majid, Kamran; Crowder, Terence; Baker, Erin; Baker, Kevin; Koueiter, Denise; Shields, Edward; Herkowitz, Harry N

2011-12-01

One hundred eighteen patients retrieved 316L stainless steel thoracolumbar plates, of 3 different designs, used for fusion in 60 patients were examined for evidence of corrosion. A medical record review and statistical analysis were also carried out. This study aims to identify types of corrosion and examine preferential metal ion release and the possibility of statistical correlation to clinical effects. Earlier studies have found that stainless steel spine devices showed evidence of mild-to-severe corrosion; fretting and crevice corrosion were the most commonly reported types. Studies have also shown the toxicity of metal ions released from stainless steel corrosion and how the ions may adversely affect bone formation and/or induce granulomatous foreign body responses. The retrieved plates were visually inspected and graded based on the degree of corrosion. The plates were then analyzed with optical microscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy. A retrospective medical record review was performed and statistical analysis was carried out to determine any correlations between experimental findings and patient data. More than 70% of the plates exhibited some degree of corrosion. Both fretting and crevice corrosion mechanisms were observed, primarily at the screw plate interface. Energy dispersive x-ray spectroscopy analysis indicated reductions in nickel content in corroded areas, suggestive of nickel ion release to the surrounding biological environment. The incidence and severity of corrosion was significantly correlated with the design of the implant. Stainless steel thoracolumbar plates show a high incidence of corrosion, with statistical dependence on device design.

The Automated Array Assembly Task of the Low-cost Silicon Solar Array Project, Phase 2

NASA Technical Reports Server (NTRS)

Coleman, M. G.; Grenon, L.; Pastirik, E. M.; Pryor, R. A.; Sparks, T. G.

1978-01-01

An advanced process sequence for manufacturing high efficiency solar cells and modules in a cost-effective manner is discussed. Emphasis is on process simplicity and minimizing consumed materials. The process sequence incorporates texture etching, plasma processes for damage removal and patterning, ion implantation, low pressure silicon nitride deposition, and plated metal. A reliable module design is presented. Specific process step developments are given. A detailed cost analysis was performed to indicate future areas of fruitful cost reduction effort. Recommendations for advanced investigations are included.

Enhanced production of electron cyclotron resonance plasma by exciting selective microwave mode on a large-bore electron cyclotron resonance ion source with permanent magnet.

PubMed

Kimura, Daiju; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Imai, Youta; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

2014-02-01

We are constructing a tandem type ECRIS. The first stage is large-bore with cylindrically comb-shaped magnet. We optimize the ion beam current and ion saturation current by a mobile plate tuner. They change by the position of the plate tuner for 2.45 GHz, 11-13 GHz, and multi-frequencies. The peak positions of them are close to the position where the microwave mode forms standing wave between the plate tuner and the extractor. The absorbed powers are estimated for each mode. We show a new guiding principle, which the number of efficient microwave mode should be selected to fit to that of multipole of the comb-shaped magnets. We obtained the excitation of the selective modes using new mobile plate tuner to enhance ECR efficiency.

Corrosion resistance and mechanical properties of titanium nitride plating on orthodontic wires.

PubMed

Sugisawa, Haruki; Kitaura, Hideki; Ueda, Kyosuke; Kimura, Keisuke; Ishida, Masahiko; Ochi, Yumiko; Kishikawa, Akiko; Ogawa, Saika; Takano-Yamamoto, Teruko

2018-03-30

Titanium nitride (TiN) coating by ion plating has properties such as high hardness, wear resistance, corrosion resistance, and surface lubricity, therefore TiN coating is often used in various dental appliances and materials. In this study, we evaluated the corrosion behaviors and mechanical properties of TiN coated stainless steel (SS) and nickel titanium (Ni-Ti) orthodontic wires prepared by ion plating. TiN coating by ion plating improves the corrosion resistance of orthodontic wires. The corrosion pitting of the TiN coated wire surface become small. The tensile strength and stiffness of SS wire were increased after TiN coating. In contrast, its elastic force, which is a property for Ni-Ti wire, was decreased. In addition, TiN coating provided small friction forces. The low level of friction may increase tooth movement efficiently. Therefore, TiN coated SS wire could be useful for orthodontics treatment.

Steven Chu - Patents

Science.gov Websites

searchQuery x Find DOE R&D Acccomplishments Navigation dropdown arrow The Basics dropdown arrow Home About , Steven; et. al.; May 3, 1988 An ion energy filter of the type useful in connection with secondary ion mass spectrometry is disclosed. The filter is composed of a stack of 20 thin metal plates, each plate

Tribological characteristics of gold films deposited on metals by ion plating and vapor deposition

NASA Technical Reports Server (NTRS)

Miyoshi, K.; Spalvins, T.; Buckley, D. H.

1984-01-01

The graded interface between an ion-plated film and a substrate is discussed as well as the friction and wear properties of ion-plated gold. X-ray photoelectron spectroscopy (XPS) depth profiling and microhardness depth profiling were used to investigate the interface. The friction and wear properties of ion-plated and vapor-deposited gold films were studied both in an ultra high vacuum system to maximize adhesion and in oil to minimize adhesion. The results indicate that the solubility of gold on the substrate material controls the depth of the graded interface. Thermal diffusion and chemical diffusion mechanisms are thought to be involved in the formation of the gold-nickel interface. In iron-gold graded interfaces the gold was primarily dispersed in the iron and thus formed a physically bonded interface. The hardness of the gold film was influenced by its depth and was also related to the composition gradient between the gold and the substrate. The graded nickel-gold interface exhibited the highest hardness because of an alloy hardening effect. The effects of film thickness on adhesion and friction were established.

Tribological characteristics of gold films deposited on metals by ion plating and vapor deposition

NASA Technical Reports Server (NTRS)

Miyoshi, K.; Spalvins, T.; Buckley, D. H.

1986-01-01

The graded interface between an ion-plated film and a substrate is discussed as well as the friction and wear properties of ion-plated gold. X-ray photoelectron spectroscopy (XPS) depth profiling and microhardness depth profiling were used to investigate the interface. The friction and wear properties of ion-plated and vapor-deposited gold films were studied both in an ultra high vacuum system to maximize adhesion and in oil to minimize adhesion. The results indicate that the solubility of gold on the substrate material controls the depth of the graded interface. Thermal diffusion and chemical diffusion mechanisms are thought to be involved in the formation of the gold-nickel interface. In iron-gold graded interfaces the gold was primarily dispersed in the iron and thus formed a physically bonded interface. The hardness of the gold film was influenced by its depth and was also related to the composition gradient between the gold and the substrate. The graded nickel-gold interface exhibited the highest hardness because of an alloy hardening effect. The effects of film thickness on adhesion and friction were established.

Fusion of Night Vision and Thermal Images

DTIC Science & Technology

2006-12-01

with the walls of the MCP channels. Thus, a thin metal oxide coating commonly known as an ion barrier film is added to the input side of the MCP to...with film ion barrier to filmless gated tubes. An important improvement for Gen 4 products is a greater target identification range and higher target...Metal Seals with S-25 Cathode Mircro-channel plate Ceramic/Metal Seals with GaAS Cathode Mircro-channel plate with ion barrier film Ceramic

Hybrid Ion-Detector/Data-Acquisition System for a TOF-MS

NASA Technical Reports Server (NTRS)

Burton, William D., Jr.; Schultz, J. Albert; Vaughn, Valentine; McCully, Michael; Ulrich, Steven; Egan, Thomas F.

2006-01-01

A modified ion-detector/data-acquisition system has been devised to increase the dynamic range of a time-of-flight mass spectrometer (TOF-MS) that, previously, included a microchannel-plate detector and a data-acquisition system based on counting pulses and time-tagging them by use of a time-to-digital converter (TDC). The dynamic range of the TOF-MS was limited by saturation of the microchannel plate detector, which can handle no more than a few million counts per second. The modified system includes (1) a combined microchannel plate/discrete ion multiplier and (2) a hybrid data-acquisition system that simultaneously performs analog current or voltage measurements and multianode single-ion-pulse-counting time-of-flight measurements to extend the dynamic range of a TDC into the regime in which a mass peak comprises multiple ions arriving simultaneously at the detector. The multianode data are used to determine, in real time, whether the detector is saturated. When saturation is detected, the data-acquisition system selectively enables circuitry that simultaneously determines the ion-peak intensity by measuring the time profile of the analog current or voltage detector-output signal.

In-situ electrochemical study of interaction of tribology and corrosion in artificial hip prosthesis simulators.

PubMed

Yan, Yu; Dowson, Duncan; Neville, Anne

2013-02-01

The second generation Metal-on-Metal (MoM) hip replacements have been considered as an alternative to commonly used Polyethylene-on-Metal (PoM) joint prostheses due to polyethylene wear debris induced osteolysis. However, the role of corrosion and the biofilm formed under tribological contact are still not fully understood. Enhanced metal ion concentrations have been reported widely from hair, blood and urine samples of patients who received metal hip replacements and in isolated cases when abnormally high levels have caused adverse local tissue reactions. An understanding of the origin of metal ions is really important in order to design alloys for reduced ion release. Reciprocating pin-on-plate wear tester is a standard instrument to assess the interaction of corrosion and wear. However, more realistic hip simulator can provide a better understanding of tribocorrosion process for hip implants. It is very important to instrument the conventional hip simulator to enable electrochemical measurements. In this study, simple reciprocating pin-on-plate wear tests and hip simulator tests were compared. It was found that metal ions originated from two sources: (a) a depassivation of the contacting surfaces due to tribology (rubbing) and (b) corrosion of nano-sized wear particles generated from the contacting surfaces. Copyright © 2012 Elsevier Ltd. All rights reserved.

Friction and Wear Properties of Selected Solid Lubricating Films. Part 2; Ion-Plated Lead Films

NASA Technical Reports Server (NTRS)

Miyoshi, Kazuhisa; Iwaki, Masanori; Gotoh, Kenichi; Obara, Shingo; Imagawa, Kichiro

2000-01-01

To evaluate commercially developed dry solid film lubricants for aerospace bearing applications, an investigation was conducted to examine the friction and wear behavior of ion-plated lead films in sliding contact with 6-mm-diameter American Iron and Steel Institute (AISI) 440C stainless steel balls. Unidirectional sliding friction experiments were conducted with a load of 5.9 N (600 g), a mean Hertzian contact pressure of 0.79 GPa (maximum Hertzian contact pressure of 1.2 GPa), and a sliding velocity of 0.2 m/s. The experiments were conducted at room temperature in three environments: ultrahigh vacuum (vacuum pressure, 7 x 10(exp -7 Pa), humid air (relative humidity, approx. 20 percent), and dry nitrogen (relative humidity, less then 1 percent). The resultant films were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and surface profilometry. Marked differences in the friction and wear of the ion-plated lead films investigated herein resulted from the environmental conditions. The main criteria for judging the performance of the ion-plated lead films were coefficient of friction and wear rate, which had to be less than 0.3 and on the order of 1(exp -6) cu mm/N.m or less, respectively. The ion-plated lead films met both criteria only in ultrahigh vacuum but failed in humid air and in dry nitrogen, where the coefficient of friction was higher than the criterion. Both the lead film wear rate and the ball wear rate met that criterion in all three environments. Adhesion and plastic deformation played important roles in the friction and wear of the ion-plated lead films in contact with 440C stainless steel balls in the three environments. All sliding involved adhesive transfer of materials: transfer of lead wear debris to the counterpart 440C stainless steel and transfer of 440C stainless steel wear debris to the counterpart lead.

An Investigation of Ionic Flows in a Sphere-Plate Electrode Gap

NASA Astrophysics Data System (ADS)

Z. Alisoy, H.; Alagoz, S.; T. Alisoy, G.; B. Alagoz, B.

2013-10-01

This paper presents analyses of ion flow characteristics and ion discharge pulses in a sphere-ground plate electrode system. As a result of variation in electric field intensity in the electrode gap, the ion flows towards electrodes generate non-uniform discharging pulses. Inspection of these pulses provides useful information on ionic stream kinetics, the effective thickness of ion cover around electrodes, and the timing of ion clouds discharge pulse sequences. A finite difference time domain (FDTD) based space-charge motion simulation is used for the numerical analysis of the spatio-temporal development of ionic flows following the first Townsend avalanche, and the simulation results demonstrate expansion of the positive ion flow and compression of the negative ion flow, which results in non-uniform discharge pulse characteristics.

Atmospheric pressure ion focusing in a high-field asymmetric waveform ion mobility spectrometer

NASA Astrophysics Data System (ADS)

Guevremont, Roger; Purves, Randy W.

1999-02-01

The focusing of ions at atmospheric pressure and room temperature in a high-field asymmetric waveform ion mobility spectrometer (FAIMS) has been investigated. FAIMS operates with the application of a high-voltage, high-frequency asymmetric waveform across parallel plates. This establishes conditions wherein an ion migrates towards one of the plates because of a difference in the ion mobility at the low and high electric field conditions during application of the waveform. The migration can be stopped by applying a dc compensation voltage (CV) which serves to create a "balanced" condition wherein the ion experiences no net transverse motion. This method has also been called "transverse field compensation ion mobility spectrometry" and "field ion spectrometry®." If this experiment is conducted using a device with cylindrical geometry, rather than with flat plates, an ion focusing region can exist in the annular space between the two concentric cylinders. Ion trajectory modeling showed that the behavior of the ions in the cylindrical geometry FAIMS analyzer was unlike any previously described atmospheric pressure ion optics system. The ions appeared to be trapped, or focused by being caught between two opposing forces. Requirements for establishing this focus for a given ion were identified: the applied waveform must be asymmetric, the electric field must be sufficiently high that the mobility of the ion deviates from its low-field value during the high-voltage portion of the asymmetric waveform, and finally, the electric field must be nonuniform in space (e.g., cylindrical or spherical geometry). Experimental observations with a prototype FAIMS device, which was designed to measure the radial distribution of ions in the FAIMS analyzer region, have confirmed the results of ion trajectory modeling.

AN ENVIRONMENTAL AND ECONOMIC COMPARISON OF ION EXCHANGE AND RECENTLY COMMERCIALIZED ELECTROCHEMICAL TECHNOLOGIES FOR THE RECOVERY OF RINSE WATER IN BRIGHT NICKEL PLATING FACILITY

EPA Science Inventory

Researchers at USEPA are testing and evaluating two commercial electrochemical technologies for the purification of rinse water and the recovery of copper and nickel from a variety of electroplating processes. One of the investigated technologies is based on the application of hi...

Plasma Processing of Materials

DTIC Science & Technology

1985-02-22

inert gas or in a reduced pressure environment) one can obtain rapidly solidified metastable (i.e., amorphous, microcrystalline, and supersaturated...integrated circuits dnd thus is an area of’vital : importance to our electronics industry. Applications utilizing noble gas plasmas, such as ion-plating...phenomena and probably will not benefit -ubstantially from acditional basic research. Applications utilizing molecular gas plasmas, where reactive species

Verification of high efficient broad beam cold cathode ion source

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

Abdel Reheem, A. M., E-mail: amreheem2009@yahoo.com; Radiation Physics Department, National Center for Radiation Research and Technology; Ahmed, M. M.

2016-08-15

An improved form of cold cathode ion source has been designed and constructed. It consists of stainless steel hollow cylinder anode and stainless steel cathode disc, which are separated by a Teflon flange. The electrical discharge and output characteristics have been measured at different pressures using argon, nitrogen, and oxygen gases. The ion exit aperture shape and optimum distance between ion collector plate and cathode disc are studied. The stable discharge current and maximum output ion beam current have been obtained using grid exit aperture. It was found that the optimum distance between ion collector plate and ion exit aperturemore » is equal to 6.25 cm. The cold cathode ion source is used to deposit aluminum coating layer on AZ31 magnesium alloy using argon ion beam current which equals 600 μA. Scanning electron microscope and X-ray diffraction techniques used for characterizing samples before and after aluminum deposition.« less

WE-EF-BRA-05: Experimental Design for High-Throughput In-Vitro RBE Measurements Using Protons, Helium and Carbon Ions

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

Guan, F; Titt, U; Patel, D

2015-06-15

Purpose: To design and validate experimental setups for investigation of dose and LET effects in cell kill for protons, helium and carbon ions, in high throughput and high accuracy cell experiments. Methods: Using the Geant4 Monte Carlo toolkit, we designed 3 custom range compensators to simultaneously expose cancer cells to different doses and LETs from selected portions of pristine ion beams from the entrance to points just beyond the Bragg peak. To minimize the spread of LET, we utilized mono-energetic uniformly scanned beams at the HIT facility with support from the DKFZ. Using different entrance doses and LETs, a matrixmore » of cell survival data was acquired leading to a specific RBE matrix. We utilized the standard clonogenic assay for H460 and H1437 lung-cancer cell lines grown in 96-well plates. Using these plates, the data could be acquired in a small number of exposures. The ion specific compensators were located in a horizontal beam, designed to hold two 96-wells plates (12 columns by 8 rows) at an angle of 30o with respect to the beam direction. Results: Using about 20 hours of beam time, a total of about 11,000 wells containing cancer cells could be irradiated. The H460 and H1437 cell lines exhibited a significant dependence on LET when they were exposed to comparable doses. The results were similar for each of the investigated ion species, and indicate the need to incorporate RBE into the ion therapy planning process. Conclusion: The experimental design developed is a viable approach to rapidly acquire large amounts of accurate in-vitro RBE data. We plan to further improve the design to achieve higher accuracy and throughput, thereby facilitating the irradiation of multiple cell types. The results are indicative of the possibility to develop a new degree of freedom (variable RBE) for future clinical ion therapy optimization. Work supported by the Sister Institute Network Fund (SINF), University of Texas MD Anderson Cancer Center.« less

Advancements in ion beam figuring of very thin glass plates (Conference Presentation)

NASA Astrophysics Data System (ADS)

Civitani, M.; Ghigo, M.; Hołyszko, J.; Vecchi, G.; Basso, S.; Cotroneo, V.; DeRoo, C. T.; Schwartz, E. D.; Reid, P. B.

2017-09-01

The high-quality surface characteristics, both in terms of figure error and of micro-roughness, required on the mirrors of a high angular resolution x-ray telescope are challenging, but in principle well suited with a deterministic and non-contact process like the ion beam figuring. This process has been recently proven to be compatible even with very thin (thickness around 0.4mm) sheet of glasses (like D263 and Eagle). In the last decade, these types of glass have been investigated as substrates for hot slumping, with residual figure errors of hundreds of nanometres. In this view, the mirrors segments fabrication could be envisaged as a simple two phases process: a first replica step based on hot slumping (direct/indirect) followed by an ion beam figuring which can be considered as a post-fabrication correction method. The first ion beam figuring trials, realized on flat samples, showed that the micro-roughness is not damaged but a deeper analysis is necessary to characterize and eventually control/compensate the glass shape variations. In this paper, we present the advancements in the process definition, both on flat and slumped glass samples.

CALUTRON ION SOURCE

DOEpatents

Lofgren, E.J.

1959-02-17

An improvement is described in ion source mechanisms whereby the source structure is better adapted to withstanid the ravages of heat, erosion, and deterioration concomitant with operation of an ion source of the calutron type. A pair of molybdenum plates define the exit opening of the arc chamber and are in thermal contact with the walls of the chamber. These plates are maintained at a reduced temperature by a pair of copper blocks in thermal conducting contact therewith to form subsequent diverging margins for the exit opening.

Coincidence ion imaging with a fast frame camera

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

Lee, Suk Kyoung; Cudry, Fadia; Lin, Yun Fei

2014-12-15

A new time- and position-sensitive particle detection system based on a fast frame CMOS (complementary metal-oxide semiconductors) camera is developed for coincidence ion imaging. The system is composed of four major components: a conventional microchannel plate/phosphor screen ion imager, a fast frame CMOS camera, a single anode photomultiplier tube (PMT), and a high-speed digitizer. The system collects the positional information of ions from a fast frame camera through real-time centroiding while the arrival times are obtained from the timing signal of a PMT processed by a high-speed digitizer. Multi-hit capability is achieved by correlating the intensity of ion spots onmore » each camera frame with the peak heights on the corresponding time-of-flight spectrum of a PMT. Efficient computer algorithms are developed to process camera frames and digitizer traces in real-time at 1 kHz laser repetition rate. We demonstrate the capability of this system by detecting a momentum-matched co-fragments pair (methyl and iodine cations) produced from strong field dissociative double ionization of methyl iodide.« less

Space Plasma Ion Processing of Ilmenite in the Lunar Soil: Insights from In-Situ TEM Ion Irradiation Experiments

NASA Technical Reports Server (NTRS)

Christoffersen, R.; Keller, L. P.

2007-01-01

Space weathering on the moon and asteroids results largely from the alteration of the outer surfaces of regolith grains by the combined effects of solar ion irradiation and other processes that include deposition of impact or sputter-derived vapors. Although no longer considered the sole driver of space weathering, solar ion irradiation remains a key part of the space weathering puzzle, and quantitative data on its effects on regolith minerals are still in short supply. For the lunar regolith, previous transmission electron microscope (TEM) studies performed by ourselves and others have uncovered altered rims on ilmenite (FeTiO3) grains that point to this phase as a unique "witness plate" for unraveling nanoscale space weathering processes. Most notably, the radiation processed portions of these ilmenite rims consistently have a crystalline structure, in contrast to radiation damaged rims on regolith silicates that are characteristically amorphous. While this has tended to support informal designation of ilmenite as a "radiation resistant" regolith mineral, there are to date no experimental data that directly and quantitatively compare ilmenite s response to ion radiation relative to lunar silicates. Such data are needed because the radiation processed rims on ilmenite grains, although crystalline, are microstructurally and chemically complex, and exhibit changes linked to the formation of nanophase Fe metal, a key space weathering process. We report here the first ion radiation processing study of ilmenite performed by in-situ means using the Intermediate Voltage Electron Microscope- Tandem Irradiation facility (IVEM-Tandem) at Argonne National Laboratory. The capability of this facility for performing real time TEM observations of samples concurrent with ion irradiation makes it uniquely suited for studying the dose-dependence of amorphization and other changes in irradiated samples.

Lithium/water battery with lithium ion conducting glass-ceramics electrolyte

NASA Astrophysics Data System (ADS)

Katoh, Takashi; Inda, Yasushi; Nakajima, Kousuke; Ye, Rongbin; Baba, Mamoru

Lithium/water batteries have attracted considerable attention as high power supply devices because they use high energy density lithium metal as an anode and water as a cathode. In this study, we investigate the use of lithium/water batteries that use a glass-ceramics plate as an electrolyte. A lithium ion conducting glass-ceramics plate has no through-holes and does not exhibit moisture permeation. Such a plate has stable ionic conductivity in water. Lithium/water batteries that used a glass-ceramics plate as an electrolyte had a long and stable discharge for 50 days at room temperature when the lithium metal was prevented from coming into contact with water. Lithium/seawater batteries using a glass-ceramics plate as an electrolyte also operated well in the 10-70 °C temperature range.

Photosensitivity enhancement of PLZT ceramics by positive ion implantation

DOEpatents

Peercy, P.S.; Land, C.E.

1980-06-13

The photosensitivity of lead lanthanum zirconate titanate (PLZT) ceramic material used in high resolution, high contrast, and non-volatile photoferroelectric image storage and display devices is enhanced significantly by positive ion implantation of the PLZT near its surface. Ions that are implanted include H/sup +/, He/sup +/, Ar/sup +/, and a preferred co-implant of Ar/sup +/ and Ne/sup +/. The positive ion implantation advantageously serves to shift the band gap energy threshold of the PLZT material from near-uv light to visible blue light. As a result, photosensitivity enhancement is such that the positive ion implanted PLZT plate is sensitive even to sunlight and conventional room lighting, such as fluorescent and incandescent light sources. The method disclosed includes exposing the PLZT plate to these positive ions of sufficient density and with sufficient energy to provide an image. The PLZT material may have a lanthanum content ranging from 5 to 10%; a lead zirconate content ranging from 62 to 70 mole %; and a lead titanate content ranging from 38 to 30%. The region of ion implantation is in a range from 0.1 to 2 microns below the surface of the PLZT plate. Density of ions is in the range from 1 x 10/sup 12/ to 1 x 10/sup 17/ ions/cm/sup 2/ and having an energy in the range from 100 to 500 keV.

Porous electrode apparatus for electrodeposition of detailed metal structures or microelectronic interconnections

DOEpatents

Griffiths, Stewart K.; Nilson, Robert H.; Hruby, Jill M.

2002-01-01

An apparatus and procedure for performing microfabrication of detailed metal structures by electroforming metal deposits within small cavities. Two primary areas of application are: the LIGA process which manufactures complex three-dimensional metal parts and the damascene process used for electroplating line and via interconnections of microelectronic devices. A porous electrode held in contact or in close proximity with a plating substrate or mold top to ensure one-dimensional and uniform current flow into all mold cavities is used. Electrolyte is pumped over the exposed surface of the porous electrode to ensure uniform ion concentrations at this external surface. The porous electrode prevents electrolyte circulation within individual mold cavities, avoiding preferential enhancement of ion transport in cavities having favorable geometries. Both current flow and ion transport are one-dimensional and identical in all mold cavities, so all metal deposits grow at the same rate eliminating nonuniformities of the prior art.

Chromatic characterization of ion-exchanged glass binary phase plates for mode-division multiplexing.

PubMed

Prieto-Blanco, Xesús; Montero-Orille, Carlos; Moreno, Vicente; Mateo, Eduardo F; Liñares, Jesús

2015-04-10

Mode-division multiplexing (MDM) in few-mode fibers is regarded as a promising candidate to increase optical network capacity. A fundamental element for MDM is a modal transformer to LP modes which can be implemented in a free-space basis by using multiregion phase plates, that is, LP plates. Likewise, several wavelengths have to be used due to wavelength multiplexing purposes, optical amplification tasks, and so on. In this work we show that efficient monolithic binary phase plates for different wavelengths can be fabricated by ion-exchange in glass and used for MDM tasks. We introduce an optical characterization method of the chromatic properties of such phase plates which combines the inverse Wentzel-Kramers-Brillouin (IWKB) together with Mach-Zehnder and Michelson-based interferometric techniques. The interferometric method provides a measurement of the phase step for several wavelengths, which characterizes the chromatic properties of the phase plate. Consequently, it is shown that the IWKB method allows us to design and characterize the phase plates in an easy and fast way.

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers.

PubMed

Alejo, A; Kar, S; Ahmed, H; Krygier, A G; Doria, D; Clarke, R; Fernandez, J; Freeman, R R; Fuchs, J; Green, A; Green, J S; Jung, D; Kleinschmidt, A; Lewis, C L S; Morrison, J T; Najmudin, Z; Nakamura, H; Nersisyan, G; Norreys, P; Notley, M; Oliver, M; Roth, M; Ruiz, J A; Vassura, L; Zepf, M; Borghesi, M

2014-09-01

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C(6+), O(8+), etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

NASA Astrophysics Data System (ADS)

Alejo, A.; Kar, S.; Ahmed, H.; Krygier, A. G.; Doria, D.; Clarke, R.; Fernandez, J.; Freeman, R. R.; Fuchs, J.; Green, A.; Green, J. S.; Jung, D.; Kleinschmidt, A.; Lewis, C. L. S.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Nersisyan, G.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Ruiz, J. A.; Vassura, L.; Zepf, M.; Borghesi, M.

2014-09-01

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C6 +, O8 +, etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Versatile, high-sensitivity faraday cup array for ion implanters

DOEpatents

Musket, Ronald G.; Patterson, Robert G.

2003-01-01

An improved Faraday cup array for determining the dose of ions delivered to a substrate during ion implantation and for monitoring the uniformity of the dose delivered to the substrate. The improved Faraday cup array incorporates a variable size ion beam aperture by changing only an insertable plate that defines the aperture without changing the position of the Faraday cups which are positioned for the operation of the largest ion beam aperture. The design enables the dose sensitivity range, typically 10.sup.11 -10.sup.18 ions/cm.sup.2 to be extended to below 10.sup.6 ions/cm.sup.2. The insertable plate/aperture arrangement is structurally simple and enables scaling to aperture areas between <1 cm.sup.2 and >750 cm.sup.2, and enables ultra-high vacuum (UHV) applications by incorporation of UHV-compatible materials.

Scintillator-based fast ion loss measurements in the EAST.

PubMed

Chang, J F; Isobe, M; Ogawa, K; Huang, J; Wu, C R; Xu, Z; Jin, Z; Lin, S Y; Hu, L Q

2016-11-01

A new scintillator-based fast ion loss detector (FILD) has been installed on Experimental Advanced Superconducting Tokamak (EAST) to investigate the fast ion loss behavior in high performance plasma with neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH). A two dimensional 40 mm × 40 mm scintillator-coated (ZnS:Ag) stainless plate is mounted in the front of the detector, capturing the escaping fast ions. Photons from the scintillator plate are imaged with a Phantom V2010 CCD camera. The lost fast ions can be measured with the pitch angle from 60° to 120° and the gyroradius from 10 mm to 180 mm. This paper will describe the details of FILD diagnostic on EAST and describe preliminary measurements during NBI and ICRH heating.

Chromium ion plating studies for enhancement of bearing lifetime

NASA Technical Reports Server (NTRS)

Davis, J. H.

1982-01-01

Six 440-C hardened stainless steel roller bearing test rods were ion plated with various chromium films of thicknesses from .2 microns to 7 microns. The thinner (approximately .2 microns) coating sample had 3 times the fatigue life of the unplated (standard) specimens. Contrastingly, the samples having thicker coatings (several microns) had short fatigue lives (about 3% of the unplated standard).

Electrochemical Corrosion Characteristics of Arc-Ion-Plated AlTiN Coating for Marine Application.

PubMed

Lee, Jung-Hyung; Kim, MyoungJun; Kim, Seong-Jong

2016-02-01

In this study, aluminum titanium nitride (AlTiN) coating was deposited by arc ion plating onto mirror finish STS 304 plate. The surface and cross-section of the coating was characterized by SEM and EDX analysis. Several electrochemical corrosion experiments were performed including rest potential measurement, potentiodynamic polarization experiment and Tafel analysis. The result of the experiments indicated that the AlTiN coating presented lower corrosion current density than the substrate material (STS 304) under uniform corrosion environment. It was also observed that AlTiN coating may have a risk of being attacked by localized corrosion attack such as pitting when pores or micro/nano particles in the coating are exposed to chloride ion containing corrosion environment, especially marine environment.

Characterization of TiCN coatings deposited by magnetron sputter-ion plating process: RBS and GDOS complementary analyses

NASA Astrophysics Data System (ADS)

Freire, F. L., Jr.; Senna, L. F.; Achete, C. A.; Hirsch, T.

1998-03-01

Hard TiCN films were deposited by dc-magnetron sputter-ion plating technique onto high-speed carbon steel S-6-5-2 (M 2). For selected deposition conditions, TiCN films were also deposited onto Si substrates. A Ti target was sputtered in ArCH 4N 2 atmosphere. The argon flux (12 sccm) was fixed and corresponds to 90% of the total flux, whereas the N 2 flux ranged from 3% to 9% of the total flux. The total pressure in the chamber during film deposition was 8-9 × 10 -2Pa. The substrate bias, Vb, was between 0 and -140V and the substrate temperature, Ts, was 350°C. Film composition and depth profile of the elements were obtained by Rutherford backscattering spectrometry (RBS) and glow discharge optical spectroscopy (GDOS). Some limitations of both techniques in analysing TiCN films were presented. The effect of methane poisoing of the Ti target and how it influences the film composition was discussed.

Heavy-ion beam induced effects in enriched gadolinium target films prepared by molecular plating

NASA Astrophysics Data System (ADS)

Mayorov, D. A.; Tereshatov, E. E.; Werke, T. A.; Frey, M. M.; Folden, C. M.

2017-09-01

A series of enriched gadolinium (Gd, Z = 64) targets was prepared using the molecular plating process for nuclear physics experiments at the Cyclotron Institute at Texas A&M University. After irradiation with 48Ca and 45Sc projectiles at center-of-target energies of Ecot = 3.8-4.7 MeV/u, the molecular films displayed visible discoloration. The morphology of the films was examined and compared to the intact target surface. The thin films underwent a heavy-ion beam-induced density change as identified by scanning electron microscopy and α-particle energy loss measurements. The films became thinner and more homogenous, with the transformation occurring early on in the irradiation. This transformation is best described as a crystalline-to-amorphous phase transition induced by atomic displacement and destruction of structural order of the original film. The chemical composition of the thin films was surveyed using energy dispersive spectroscopy and X-ray diffraction, with the results confirming the complex chemistry of the molecular films previously noted in other publications.

Ion sputter textured graphite electrode plates

NASA Technical Reports Server (NTRS)

Curren, A. N.; Forman, R.; Sovey, J. S.; Wintucky, E. G. (Inventor)

1983-01-01

A specially textured surface of pyrolytic graphite exhibits extremely low yields of secondary electrons and reduced numbers of reflected primary electrons after impingement of high energy primary electrons. Electrode plates of this material are used in multistage depressed collectors. An ion flux having an energy between 500 iV and 1000 iV and a current density between 1.0 mA/sq cm and 6.0 mA/sq cm produces surface roughening or texturing which is in the form of needles or spires. Such textured surfaces are especially useful as anode collector plates in high tube devices.

Absolute ion detection efficiencies of microchannel plates and funnel microchannel plates for multi-coincidence detection

NASA Astrophysics Data System (ADS)

Fehre, K.; Trojanowskaja, D.; Gatzke, J.; Kunitski, M.; Trinter, F.; Zeller, S.; Schmidt, L. Ph. H.; Stohner, J.; Berger, R.; Czasch, A.; Jagutzki, O.; Jahnke, T.; Dörner, R.; Schöffler, M. S.

2018-04-01

Modern momentum imaging techniques allow for the investigation of complex molecules in the gas phase by detection of several fragment ions in coincidence. For these studies, it is of great importance that the single-particle detection efficiency ɛ is as high as possible, as the overall efficiency scales with ɛn, i.e., the power of the number of detected particles. Here we present measured absolute detection efficiencies for protons of several micro-channel plates (MCPs), including efficiency enhanced "funnel MCPs." Furthermore, the relative detection efficiency for two-, three-, four-, and five-body fragmentation of CHBrClF has been examined. The "funnel" MCPs exhibit an efficiency of approximately 90%, gaining a factor of 24 (as compared to "normal" MCPs) in the case of a five-fold ion coincidence detection.

Unsteady Heat and Mass Transfer of Chemically Reacting Micropolar Fluid in a Porous Channel with Hall and Ion Slip Currents

PubMed Central

2014-01-01

This paper presents an incompressible two-dimensional heat and mass transfer of an electrically conducting micropolar fluid flow in a porous medium between two parallel plates with chemical reaction, Hall and ion slip effects. Let there be periodic injection or suction at the lower and upper plates and the nonuniform temperature and concentration at the plates are varying periodically with time. The flow field equations are reduced to nonlinear ordinary differential equations using similarity transformations and then solved numerically by quasilinearization technique. The profiles of velocity components, microrotation, temperature distribution and concentration are studied for different values of fluid and geometric parameters such as Hartmann number, Hall and ion slip parameters, inverse Darcy parameter, Prandtl number, Schmidt number, and chemical reaction rate and shown in the form of graphs. PMID:27419211

Materials Processes (MP) Engineering Internship Projects

NASA Technical Reports Server (NTRS)

Tomsik, Elizabeth

2017-01-01

This poster illustrates my major and minor projects worked on during my entire time interning at KSC in the Materials Science Branch. My major projects consist of three Failure Analyses, a research project on Magnesium Alloys, and the manufacturing and mechanical testing of the Advanced Plant Habitat. My three Failure Analyses are Umbilical Testing Ground Plates, Lithium Ion Battery Locking Spring Blade, and a Liquid Oxygen Poppet.

METHOD OF APPLYING COPPER COATINGS TO URANIUM

DOEpatents

Gray, A.G.

1959-07-14

A method is presented for protecting metallic uranium, which comprises anodic etching of the uranium in an aqueous phosphoric acid solution containing chloride ions, cleaning the etched uranium in aqueous nitric acid solution, promptly electro-plating the cleaned uranium in a copper electro-plating bath, and then electro-plating thereupon lead, tin, zinc, cadmium, chromium or nickel from an aqueous electro-plating bath.

Coaxial ion trap mass spectrometer: concentric toroidal and quadrupolar trapping regions.

PubMed

Peng, Ying; Hansen, Brett J; Quist, Hannah; Zhang, Zhiping; Wang, Miao; Hawkins, Aaron R; Austin, Daniel E

2011-07-15

We present the design and results for a new radio-frequency ion trap mass analyzer, the coaxial ion trap, in which both toroidal and quadrupolar trapping regions are created simultaneously. The device is composed of two parallel ceramic plates, the facing surfaces of which are lithographically patterned with concentric metal rings and covered with a thin film of germanium. Experiments demonstrate that ions can be trapped in either region, transferred from the toroidal to the quadrupolar region, and mass-selectively ejected from the quadrupolar region to a detector. Ions trapped in the toroidal region can be transferred to the quadrupole region using an applied ac signal in the radial direction, although it appears that the mechanism of this transfer does not involve resonance with the ion secular frequency, and the process is not mass selective. Ions in the quadrupole trapping region are mass analyzed using dipole resonant ejection. Multiple transfer steps and mass analysis scans are possible on a single population of ions, as from a single ionization/trapping event. The device demonstrates better mass resolving power than the radially ejecting halo ion trap and better sensitivity than the planar quadrupole ion trap.

Coincidence electron/ion imaging with a fast frame camera

NASA Astrophysics Data System (ADS)

Li, Wen; Lee, Suk Kyoung; Lin, Yun Fei; Lingenfelter, Steven; Winney, Alexander; Fan, Lin

2015-05-01

A new time- and position- sensitive particle detection system based on a fast frame CMOS camera is developed for coincidence electron/ion imaging. The system is composed of three major components: a conventional microchannel plate (MCP)/phosphor screen electron/ion imager, a fast frame CMOS camera and a high-speed digitizer. The system collects the positional information of ions/electrons from a fast frame camera through real-time centroiding while the arrival times are obtained from the timing signal of MCPs processed by a high-speed digitizer. Multi-hit capability is achieved by correlating the intensity of electron/ion spots on each camera frame with the peak heights on the corresponding time-of-flight spectrum. Efficient computer algorithms are developed to process camera frames and digitizer traces in real-time at 1 kHz laser repetition rate. We demonstrate the capability of this system by detecting a momentum-matched co-fragments pair (methyl and iodine cations) produced from strong field dissociative double ionization of methyl iodide. We further show that a time resolution of 30 ps can be achieved when measuring electron TOF spectrum and this enables the new system to achieve a good energy resolution along the TOF axis.

CALUTRON

DOEpatents

Schmidt, F.H.

1958-08-12

An improved ion source is described for accurately presetting the size amd location of the gas and ion efflux opening. for determining the contour of the electrical field in the vicinity of the arc, and for generally improving the operation of the calutron source. The above features are accomplished by the use of a pair of electrically conductive coplanar plates mounted on opposite sides of the ion exit passage of the source ionization chamber and electrically connected to the source block. The plates are mounted on thc block for individual movement tramsversely of the exit slit and can be secured in place by clannping means.

Facile solvothermal synthesis of NaTi2(PO4)3/C porous plates as electrode materials for high-performance sodium ion batteries

NASA Astrophysics Data System (ADS)

Huang, Zhifeng; Liu, Li; Yi, Lingguang; Xiao, Wei; Li, Min; Zhou, Qian; Guo, Guoxiong; Chen, Xiaoying; Shu, Hongbo; Yang, Xiukang; Wang, Xianyou

2016-09-01

NaTi2(PO4)3/C porous plates have been successfully synthesized via solvothermal approach with ammonia as inductive agent combined in-situ carbon coating. It reveals that the inductive agent plays a critical role in morphology-controllable fabrication. The morphology, structure, and electrochemical properties of NaTi2(PO4)3/C composites with multilayered plates, single-layered plate, porous multilayered plates all have been investigated, which are prepared by using urea, triethylamine, and ammonia, respectively. Among these samples, NaTi2(PO4)3/C porous multilayered plates with ammonia addition exhibit the best electrochemical properties due to their unique mesoporous structure. NaTi2(PO4)3/C porous multilayered plates deliver an initial specific capacity of 125 and 110 mAh g-1 at 0.1 and 1 C, respectively. Furthermore, NaTi2(PO4)3/C porous multilayered plates show a good rate capability, whose capacity and corresponding capacity retention reach 85 mAh g-1 and 82.4%, respectively, after 120 cycles under the high rate of 10 C. The excellent results indicate that the NaTi2(PO4)3/C porous multilayered plates are a promising electrode candidate for sodium ion battery.

Image intensifier gain uniformity improvements in sealed tubes by selective scrubbing

DOEpatents

Thomas, S.W.

1995-04-18

The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible. 4 figs.

Image intensifier gain uniformity improvements in sealed tubes by selective scrubbing

DOEpatents

Thomas, Stanley W.

1995-01-01

The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible.

AMS implications of charge-changing during acceleration

NASA Astrophysics Data System (ADS)

Knies, D. L.; Grabowski, K. S.; Cetina, C.; Demoranville, L. T.; Dougherty, M. R.; Mignerey, A. C.; Taylor, C. L.

2007-08-01

The NRL Accelerator Mass Spectrometer facility was recently reconfigured to incorporate a modified Cameca IMS 6f Secondary Ion Mass Spectrometer as a high-performance ion source. The NRL accelerator facility supplants the mass spectrometer portion of the IMS 6f instrument. As part of the initial testing of the combined instrument, charge-state scans were performed under various conditions. These provided the basis for studying the effects of terminal gas pressure on the process of charge-changing during acceleration. A combined system of transmission-micro-channel plate and energy detector was found to remove ghost beams produced from Pd charge-changing events in the accelerator tube.

The automated array assembly task of the low-cost silicon solar array project, phase 2

NASA Technical Reports Server (NTRS)

Coleman, M. G.; Pryor, R. A.; Sparks, T. G.; Legge, R.; Saltzman, D. L.

1980-01-01

Several specific processing steps as part of a total process sequence for manufacturing silicon solar cells were studied. Ion implantation was identified as the preferred process step for impurity doping. Unanalyzed beam ion implantation was shown to have major cost advantages over analyzed beam implantation. Further, high quality cells were fabricated using a high current unanalyzed beam. Mechanically masked plasma patterning of silicon nitride was shown to be capable of forming fine lines on silicon surfaces with spacings between mask and substrate as great as 250 micrometers. Extensive work was performed on advances in plated metallization. The need for the thick electroless palladium layer was eliminated. Further, copper was successfully utilized as a conductor layer utilizing nickel as a barrier to copper diffusion into the silicon. Plasma etching of silicon for texturing and saw damage removal was shown technically feasible but not cost effective compared to wet chemical etching techniques.

Development of a beam ion velocity detector for the heavy ion beam probe

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

Fimognari, P. J., E-mail: PJFimognari@XanthoTechnologies.com; Crowley, T. P.; Demers, D. R.

2016-11-15

In an axisymmetric plasma, the conservation of canonical angular momentum constrains heavy ion beam probe (HIBP) trajectories such that measurement of the toroidal velocity component of secondary ions provides a localized determination of the poloidal flux at the volume where they originated. We have developed a prototype detector which is designed to determine the beam angle in one dimension through the detection of ion current landing on two parallel planes of detecting elements. A set of apertures creates a pattern of ion current on wires in the first plane and solid metal plates behind them; the relative amounts detected bymore » the wires and plates determine the angle which beam ions enter the detector, which is used to infer the toroidal velocity component. The design evolved from a series of simulations within which we modeled ion beam velocity changes due to equilibrium and fluctuating magnetic fields, along with the ion beam profile and velocity dispersion, and studied how these and characteristics such as the size, cross section, and spacing of the detector elements affect performance.« less

CALUTRON FACE PLATE

DOEpatents

Brobeck, W.M.

1959-08-25

The construction of a removable cover plate for a calutron tank is described. The plate is fabricated of a rectangular frame member to which is welded a bowed or dished plate of thin steel, reinforced with transverse stiffening ribs. When the tank is placed between the poles of a magnet, the plate may be pivoted away from the tank and magnet and is adapted to support the ion separation mechanism secured to its inner side as well as the vacuum load within the tank.

Small Deflection Energy Analyzer for Energy and Angular Distributions

NASA Technical Reports Server (NTRS)

Herrero, Federico A.

2009-01-01

The development of the Small Deflection Energy Analyzer (SDEA) charged-particle spectrometer for energy and angle distributions responds to a longstanding need to measure the wind velocity vector in Earth s thermosphere, and to obtain the ion-drift vector in the ionosphere. The air and ions above 120 km are endowed with bulk velocities and temperatures just like air near the ground, but with separate spatial and temporal variations. It is important to understand these not only for study of the physics and chemistry of the Sun-Earth connection, but also for spacecraft orbit predictions, and communications through the ionosphere. The SDEA consists of a pair of parallel conducting plates separated by a small distance, with an entrance slit on one end, and an exit slit on the other. A voltage applied to these plates develops an electric field between the plates, and this field deflects ions passing through it. If an ion has too little energy, it will strike one of the plates. If it has too much, it will strike the back wall. An ion with the amount of energy being searched for will have its trajectory bent just enough to exit the back slit. The SDEA units are compact, rectangular, and operate with low voltages. The units can be built up into small arrays. These arrays could be used either to widen the field of view or to sharpen an existing one. This approach can also be used to obtain angular distributions in two planes simultaneously, thus cutting down the ion source power requirements in half. This geometry has enabled a new mass-spectrometer concept that can provide miniaturized mass spectrometers for use in industrial plants, air-pollution monitoring, and noxious-gas detection.

Plasma monitoring of the RLVIP-process with a Langmuir probe

NASA Astrophysics Data System (ADS)

Huber, D.; Hallbauer, A.; Pulker, H. K.

2005-09-01

The aim of this investigation was to study the characteristics of a reactive-low-voltage-high-current-ion-plating plasma and to correlate the observed plasma data with the properties of films deposited under such conditions. A Langmuir probe system (Smart Probe - Scientific Systems) was inserted into a Balzers BAP 800 ion plating plant above the e-gun evaporation source close to the insulated substrate holder. In this position during RLVIP deposition, plasma potential, floating potential, self-bias voltage, electron temperature, ion current density, and particle number density were measured and calculated, respectively. All measurements were performed in dependence of arc current (20-80A) and oxygen partial pressure (1 - 36 x 10-4mbar). With rising arc current the number of charged particles, the self-bias voltage between plasma and substrates as well as the energy of the condensing and bombarding species were increased. These data explain the increase of density, refractive index and mechanical stress of RLVIP-metal-oxide-layers, like Ta2O5 and Nb2O5, deposited with higher arc currents. An increase of gas pressure decreased the energy of the particles and therefore reduced slightly film density and refractive index. However, it improved chemistry and eliminated unwanted residual optical absorption and also decreased compressive mechanical film stress.

Removal of copper from aqueous solution using perlite

NASA Astrophysics Data System (ADS)

Tanaydin, Mehmet Kayra; Tanaydin, Zümra Bakici; Ince, Muharrem; Demırkiran, Nizamettin

2017-04-01

The wastewaters containing organic and inorganic pollutants after many industrial processes such as metal plating, mining, textile, alloy, battery and industrial chemicals, are often discharged to environment. Heavy metals among these pollutants have highly stable, toxic, non-degradable and carcinogenic characters. They affect not only ecological system, but also human health and many life forms. Therefore, these contaminants should be eliminated or reduced to allowable levels before releasing to environment. Most of heavy metals have toxic character even at low concentrations of about 0.1-0.3 ppm. Treatment technologies such as filtration, ion exchange, precipitation, electrodeposition, reverse osmosis, sedimentation, and adsorption have been applied for removal of heavy metals from aqueous solutions. Adsorption is one of the most common and widely applied methods to eliminate the metal ions from waste solutions because of its simplicity and cost effectiveness. Activated carbon, clay minerals, ion exchange resins and various agricultural residues can be used as adsorbent materials in this process [1-3].

Cadmium biosorption rate in protonated Sargassum biomass

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

Yang, J.; Volesky, B.

1999-03-01

Biosorption of the heavy metal ion Cd{sup 2+} by protonated nonliving brown alga Sargassum fluitans biomass was accompanied by the release of hydrogen protons from the biomass. The uptake of cadmium and the release of proton matched each other throughout the biosorption process. The end-point titration methodology was used to maintain the constant pH 4.0 for developing the dynamic sorption rate. The sorption isotherm could be well represented by the Langmuir sorption model. A mass transfer model assuming the intraparticle diffusion in a one-dimensional thin plate as a controlling step was developed to describe the overall biosorption rate of cadmiummore » ions in flat seaweed biomass particles. The overall biosorption mathematical model equations were solved numerically yielding the effective diffusion coefficient D{sub e} about 3.5 {times} 10{sup {minus}6} cm{sup 2}/s. This value matches that obtained for the desorption process and is approximately half of that of the molecular diffusion coefficient for cadmium ions in aqueous solution.« less

Metal deposition by electroless plating on polydopamine functionalized micro- and nanoparticles.

PubMed

Mondin, Giovanni; Wisser, Florian M; Leifert, Annika; Mohamed-Noriega, Nasser; Grothe, Julia; Dörfler, Susanne; Kaskel, Stefan

2013-12-01

A novel approach for the fabrication of metal coated micro- and nanoparticles by functionalization with a thin polydopamine layer followed by electroless plating is reported. The particles are initially coated with polydopamine via self-polymerization. The resulting polydopamine coated particles have a surface rich in catechols and amino groups, resulting in a high affinity toward metal ions. Thus, they provide an effective platform for selective electroless metal deposition without further activation and sensitization steps. The combination of a polydopamine-based functionalization with electroless plating ensures a simple, scalable, and cost-effective metal coating strategy. Silver-plated tungsten carbide microparticles, copper-plated tungsten carbide microparticles, and copper-plated alumina nanoparticles were successfully fabricated, showing also the high versatility of the method, since the polymerization of dopamine leads to the formation of an adherent polydopamine layer on the surface of particles of any material and size. The metal coated particles produced with this process are particularly well suited for the production of metal matrix composites, since the metal coating increases the wettability of the particles by the metal, promoting their integration within the matrix. Such composite materials are used in a variety of applications including electrical contacts, components for the automotive industries, magnets, and electromagnetic interference shielding. Copyright © 2013 Elsevier Inc. All rights reserved.

A simulation study of a dual-plate in-room PET system for dose verification in carbon ion therapy

NASA Astrophysics Data System (ADS)

Chen, Ze; Hu, Zheng-Guo; Chen, Jin-Da; Zhang, Xiu-Ling; Guo, Zhong-Yan; Xiao, Guo-Qing; Sun, Zhi-Yu; Huang, Wen-Xue; Wang, Jian-Song

2014-08-01

During carbon ion therapy, lots of positron emitters such as 11C, 15O, 10C are generated in irradiated tissues by nuclear reactions, and can be used to track the carbon beam in the tissue by a positron emission tomography (PET) scanner. In this study, an dual-plate in-room PET scanner has been designed and evaluated based on the GATE simulation platform to monitor patient dose in carbon ion therapy. The dual-plate PET is designed to avoid interference with the carbon beamline and with patient positioning. Its performance was compared with that of four-head and full-ring PET scanners. The dual-plate, four-head and full-ring PET scanners consisted of 30, 60, 60 detector modules, respectively, with a 36 cm distance between directly opposite detector modules for dose deposition measurements. Each detector module consisted of a 24×24 array of 2 mm×2 mm×18 mm LYSO pixels coupled to a Hamamatsu H8500 PMT. To estimate the production yield of positron emitters, a 10 cm×15 cm×15 cm cuboid PMMA phantom was irradiated with 172, 200, 250 MeV/u 12C beams. 3D images of the activity distribution measured by the three types of scanner are produced by an iterative reconstruction algorithm. By comparing the longitudinal profile of positron emitters along the carbon beam path, it is indicated that use of the dual-plate PET scanner is feasible for monitoring the dose distribution in carbon ion therapy.

Additive-free size-controlled synthesis of gold square nanoplates using photochemical reaction in dynamic phase-separating media.

PubMed

Kajimoto, Shinji; Shirasawa, Daisuke; Horimoto, Noriko Nishizawa; Fukumura, Hiroshi

2013-05-14

Ultrafast phase separation of water and 2-butoxyethanol mixture was induced by nanosecond IR laser pulse irradiation. After a certain delay time, a UV laser pulse was introduced to induce photoreduction of aurate ions, which led to the formation of gold nanoparticles in dynamic phase-separating media. The structure and size of the nanoparticles varied depending on the delay time between the IR and UV pulses. For a delay time of 5 and 6 μs, gold square plates having edge lengths of 150 and 100 nm were selectively obtained, respectively. With a delay time of 3 μs, on the other hand, the size of the square plates varied widely from 100 nm to a few micrometers. The size of the gold square plates was also varied by varying the total irradiation time of the IR and UV pulses. The size distribution of the square plates obtained under different conditions suggests that the growth process of the square plates was affected by the size of the nanophases during phase separation. Electron diffraction patterns of the synthesized square plates showed that the square plates were highly crystalline with a Au(100) surface. These results showed that the nanophases formed during laser-induced phase separation can provide detergent-free reaction fields for size-controlled nanomaterial synthesis.

A revisit to self-excited push pull vacuum tube radio frequency oscillator for ion sources and power measurements

NASA Astrophysics Data System (ADS)

Hlondo, L. R.; Lalremruata, B.; Punte, L. R. M.; Rebecca, L.; Lalnunthari, J.; Thanga, H. H.

2016-04-01

Self-excited push-pull vacuum tube oscillator is one of the most commonly used oscillators in radio frequency (RF)-ion plasma sources for generation of ions using radio frequency. However, in spite of its fundamental role in the process of plasma formation, the working and operational characteristics are the most frequently skip part in the descriptions of RF ion sources in literatures. A more detailed treatment is given in the present work on the RF oscillator alone using twin beam power tetrodes 829B and GI30. The circuit operates at 102 MHz, and the oscillation conditions, stability in frequency, and RF output power are studied and analyzed. A modified form of photometric method and RF peak voltage detection method are employed to study the variation of the oscillator output power with plate voltage. The power curves obtained from these measurements are quadratic in nature and increase with increase in plate voltage. However, the RF output power as measured by photometric methods is always less than the value calculated from peak voltage measurements. This difference is due to the fact that the filament coil of the ordinary light bulb used as load/detector in photometric method is not a perfect inductor. The effect of inductive reactance on power transfer to load was further investigated and a technique is developed to estimate the amount of power correction needed in the photometric measurement result.

A revisit to self-excited push pull vacuum tube radio frequency oscillator for ion sources and power measurements

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

Hlondo, L. R.; Lalremruata, B.; Punte, L. R. M.

Self-excited push-pull vacuum tube oscillator is one of the most commonly used oscillators in radio frequency (RF)-ion plasma sources for generation of ions using radio frequency. However, in spite of its fundamental role in the process of plasma formation, the working and operational characteristics are the most frequently skip part in the descriptions of RF ion sources in literatures. A more detailed treatment is given in the present work on the RF oscillator alone using twin beam power tetrodes 829B and GI30. The circuit operates at 102 MHz, and the oscillation conditions, stability in frequency, and RF output power aremore » studied and analyzed. A modified form of photometric method and RF peak voltage detection method are employed to study the variation of the oscillator output power with plate voltage. The power curves obtained from these measurements are quadratic in nature and increase with increase in plate voltage. However, the RF output power as measured by photometric methods is always less than the value calculated from peak voltage measurements. This difference is due to the fact that the filament coil of the ordinary light bulb used as load/detector in photometric method is not a perfect inductor. The effect of inductive reactance on power transfer to load was further investigated and a technique is developed to estimate the amount of power correction needed in the photometric measurement result.« less

A revisit to self-excited push pull vacuum tube radio frequency oscillator for ion sources and power measurements.

PubMed

Hlondo, L R; Lalremruata, B; Punte, L R M; Rebecca, L; Lalnunthari, J; Thanga, H H

2016-04-01

Self-excited push-pull vacuum tube oscillator is one of the most commonly used oscillators in radio frequency (RF)-ion plasma sources for generation of ions using radio frequency. However, in spite of its fundamental role in the process of plasma formation, the working and operational characteristics are the most frequently skip part in the descriptions of RF ion sources in literatures. A more detailed treatment is given in the present work on the RF oscillator alone using twin beam power tetrodes 829B and GI30. The circuit operates at 102 MHz, and the oscillation conditions, stability in frequency, and RF output power are studied and analyzed. A modified form of photometric method and RF peak voltage detection method are employed to study the variation of the oscillator output power with plate voltage. The power curves obtained from these measurements are quadratic in nature and increase with increase in plate voltage. However, the RF output power as measured by photometric methods is always less than the value calculated from peak voltage measurements. This difference is due to the fact that the filament coil of the ordinary light bulb used as load/detector in photometric method is not a perfect inductor. The effect of inductive reactance on power transfer to load was further investigated and a technique is developed to estimate the amount of power correction needed in the photometric measurement result.

CALUTRON ION SOURCE

DOEpatents

Brobeck, W.M.

1959-02-24

An ion source is described wherein a portion of the filament serving as a cathode for the arc is protected from the effects of non-ionized particles escaping from the ionizing mechanism. In the described ion source, the source block has a gas chamber and a gas passage extending from said gas chamber to two adjacent faces of the source block. A plate overlies the passage and abuts one of the aforementioned block faces, while extending beyond the other face. In addition, the plate is apertured in line with the block passage. The filament overlies the aperture to effectively shield the portion of the filament not directiy aligned with the passage where the arc is produced.

In Situ Field Sequencing and Life Detection in Remote (79°26'N) Canadian High Arctic Permafrost Ice Wedge Microbial Communities.

PubMed

Goordial, J; Altshuler, Ianina; Hindson, Katherine; Chan-Yam, Kelly; Marcolefas, Evangelos; Whyte, Lyle G

2017-01-01

Significant progress is being made in the development of the next generation of low cost life detection instrumentation with much smaller size, mass and energy requirements. Here, we describe in situ life detection and sequencing in the field in soils over laying ice wedges in polygonal permafrost terrain on Axel Heiberg Island, located in the Canadian high Arctic (79°26'N), an analog to the polygonal permafrost terrain observed on Mars. The life detection methods used here include (1) the cryo-iPlate for culturing microorganisms using diffusion of in situ nutrients into semi-solid media (2) a Microbial Activity Microassay (MAM) plate (BIOLOG Ecoplate) for detecting viable extant microorganisms through a colourimetric assay, and (3) the Oxford Nanopore MinION for nucleic acid detection and sequencing of environmental samples and the products of MAM plate and cryo-iPlate. We obtained 39 microbial isolates using the cryo-iPlate, which included several putatively novel strains based on the 16S rRNA gene, including a Pedobacter sp. (96% closest similarity in GenBank) which we partially genome sequenced using the MinION. The MAM plate successfully identified an active community capable of L-serine metabolism, which was used for metagenomic sequencing with the MinION to identify the active and enriched community. A metagenome on environmental ice wedge soil samples was completed, with base calling and uplink/downlink carried out via satellite internet. Validation of MinION sequencing using the Illumina MiSeq platform was consistent with the results obtained with the MinION. The instrumentation and technology utilized here is pre-existing, low cost, low mass, low volume, and offers the prospect of equipping micro-rovers and micro-penetrators with aggressive astrobiological capabilities. Since potentially habitable astrobiology targets have been identified (RSLs on Mars, near subsurface water ice on Mars, the plumes and oceans of Europa and Enceladus), future astrobiology missions will certainly target these areas and there is a need for direct life detection instrumentation.

Target Plate Material Influence on Fullerene-C60 Laser Desorption/Ionization Efficiency

NASA Astrophysics Data System (ADS)

Zeegers, Guido P.; Günthardt, Barbara F.; Zenobi, Renato

2016-04-01

Systematic laser desorption/ionization (LDI) experiments of fullerene-C60 on a wide range of target plate materials were conducted to gain insight into the initial ion formation in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The positive and negative ion signal intensities of precursor, fragment, and cluster ions were monitored, varying both the laser fluence (0-3.53 Jcm-2) and the ion extraction delay time (0-950 ns). The resulting species-specific ion signal intensities are an indication for the ionization mechanisms that contribute to LDI and the time frames in which they operate, providing insight in the (MA)LDI primary ionization. An increasing electrical resistivity of the target plate material increases the fullerene-C60 precursor and fragment anion signal intensity. Inconel 625 and Ti90/Al6/V4, both highly electrically resistive, provide the highest anion signal intensities, exceeding the cation signal intensity by a factor ~1.4 for the latter. We present a mechanism based on transient electrical field strength reduction to explain this trend. Fullerene-C60 cluster anion formation is negligible, which could be due to the high extraction potential. Cluster cations, however, are readily formed, although for high laser fluences, the preferred channel is formation of precursor and fragment cations. Ion signal intensity depends greatly on the choice of substrate material, and careful substrate selection could, therefore, allow for more sensitive (MA)LDI measurements.

Ion-ion coincidence imaging at high event rate using an in-vacuum pixel detector.

PubMed

Long, Jingming; Furch, Federico J; Durá, Judith; Tremsin, Anton S; Vallerga, John; Schulz, Claus Peter; Rouzée, Arnaud; Vrakking, Marc J J

2017-07-07

A new ion-ion coincidence imaging spectrometer based on a pixelated complementary metal-oxide-semiconductor detector has been developed for the investigation of molecular ionization and fragmentation processes in strong laser fields. Used as a part of a velocity map imaging spectrometer, the detection system is comprised of a set of microchannel plates and a Timepix detector. A fast time-to-digital converter (TDC) is used to enhance the ion time-of-flight resolution by correlating timestamps registered separately by the Timepix detector and the TDC. In addition, sub-pixel spatial resolution (<6 μm) is achieved by the use of a center-of-mass centroiding algorithm. This performance is achieved while retaining a high event rate (10 4 per s). The spectrometer was characterized and used in a proof-of-principle experiment on strong field dissociative double ionization of carbon dioxide molecules (CO 2 ), using a 400 kHz repetition rate laser system. The experimental results demonstrate that the spectrometer can detect multiple ions in coincidence, making it a valuable tool for studying the fragmentation dynamics of molecules in strong laser fields.

Ion-ion coincidence imaging at high event rate using an in-vacuum pixel detector

NASA Astrophysics Data System (ADS)

Long, Jingming; Furch, Federico J.; Durá, Judith; Tremsin, Anton S.; Vallerga, John; Schulz, Claus Peter; Rouzée, Arnaud; Vrakking, Marc J. J.

2017-07-01

A new ion-ion coincidence imaging spectrometer based on a pixelated complementary metal-oxide-semiconductor detector has been developed for the investigation of molecular ionization and fragmentation processes in strong laser fields. Used as a part of a velocity map imaging spectrometer, the detection system is comprised of a set of microchannel plates and a Timepix detector. A fast time-to-digital converter (TDC) is used to enhance the ion time-of-flight resolution by correlating timestamps registered separately by the Timepix detector and the TDC. In addition, sub-pixel spatial resolution (<6 μm) is achieved by the use of a center-of-mass centroiding algorithm. This performance is achieved while retaining a high event rate (104 per s). The spectrometer was characterized and used in a proof-of-principle experiment on strong field dissociative double ionization of carbon dioxide molecules (CO2), using a 400 kHz repetition rate laser system. The experimental results demonstrate that the spectrometer can detect multiple ions in coincidence, making it a valuable tool for studying the fragmentation dynamics of molecules in strong laser fields.

Isotope separation apparatus

DOEpatents

Arnush, Donald; MacKenzie, Kenneth R.; Wuerker, Ralph F.

1980-01-01

Isotope separation apparatus consisting of a plurality of cells disposed adjacent to each other in an evacuated container. A common magnetic field is established extending through all of the cells. A source of energetic electrons at one end of the container generates electrons which pass through the cells along the magnetic field lines. Each cell includes an array of collector plates arranged in parallel or in tandem within a common magnetic field. Sets of collector plates are disposed adjacent to each other in each cell. Means are provided for differentially energizing ions of a desired isotope by applying energy at the cyclotron resonant frequency of the desired isotope. As a result, the energized desired ions are preferentially collected by the collector plates.

Effect of an annealing on magnetic properties of Fe-Ni films electroplated in citric-acid-based plating baths

NASA Astrophysics Data System (ADS)

Yanai, T.; Koda, K.; Eguchi, K.; Morimura, T.; Takashima, K.; Nakano, M.; Fukunaga, H.

2018-04-01

We have already reported Fe-Ni films with good soft magnetic properties prepared by using an electroplating method. In the present study, we employed an annealing for further improvement in soft magnetic properties of the electroplated Fe-Ni films. The annealing reduces the coercivity of the films, and the reduction rate of the coercivity depended on the Cl- ion concentration in the bath. The Fe22Ni78 films prepared in the plating bath with high Cl- ion concentration showed large reduction rate of the coercivity, and we found that the annealing is more effective for high Cl- ion concentration bath since much lower coercivity value can be obtained compared with that for low Cl- ion concentration one.

[Analysis of bactericidal material generated by electrical devices advertising bactericidal ability against bacteria on the agar gel plates].

PubMed

Nishimura, Hidekazu

2012-11-01

Several Japanese companies sell electrical devices advertised as effective in inactivating viruses and killing bacteria by releasing special materials, e.g., Plasmacluster ions, Nanoe particle and minus ions, into the air. These companies claim that their devices killed bacteria on plates in their own experiments. We tested device effectiveness using the same experiments from the Plasmacluster ioniser SHARP Co., Japan, the Nanoe generator Panasonic Co., Japan, and the Vion KING JIM Co., Japan, to test their advertising claims. Bactericidal ability on agar plate was tested, using Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus cereus, and Enterococcus faecalis as follows: the medium containing a certain amount of each bacterium was put onto an agar plate and smeared. Plates were kept in a closed chamber (inner volume 14.4 m3) or a glove box (inner volume 0.2 m), with one of the devices run for 2 hours. Plates not exposed to any device were used as controls. Each plate was retrieved and put in an incubator to count the number of bacterial colonies formed on the plate. There was no significant difference in the number of colonies on plates exposed to devices compared to control, in the number for all devices, or in all bacteria tested in experiments in the 14.4 m3 chamber. These results strongly suggest that these devices have almost no bactericidal effect, at least in space exceeding this volume. Colony formation was suppressed in the glove box in all devices and in all bacteria tested except P. aeruginosa, although the degree of suppression differed among experiments. The colony formation suppression mechanism was analyzed, and indicated that:colony formation did not change even after the removal of Plasmacluster ions, Nanoe particles, or negative ions from the air, while colony formation was decreased drastically by the removal of ozone from space, which was revealed to be generated inevitably during device operation. These results strongly suggest that the bactericidal effect seen only on the agar plate in narrow space was explained by ozone released in space as a by-product, not by special materials as advertising claimed. It is thus important to analyze the effect of special materials such as those done in this study and to suggest the involvement of ozone as the true cause, as have been done in this study, in evaluating bactericidal effect or viral inactivation as advertised by these companies.

Method of preparing mercury with an arbitrary isotopic distribution

DOEpatents

Grossman, Mark W.; George, William A.

1986-01-01

This invention provides for a process for preparing mercury with a predetermined, arbitrary, isotopic distribution. In one embodiment, different isotopic types of Hg.sub.2 Cl.sub.2, corresponding to the predetermined isotopic distribution of Hg desired, are placed in an electrolyte solution of HCl and H.sub.2 O. The resulting mercurous ions are then electrolytically plated onto a cathode wire producing mercury containing the predetermined isotopic distribution. In a similar fashion, Hg with a predetermined isotopic distribution is obtained from different isotopic types of HgO. In this embodiment, the HgO is dissolved in an electrolytic solution of glacial acetic acid and H.sub.2 O. The isotopic specific Hg is then electrolytically plated onto a cathode and then recovered.

Method of preparing mercury with an arbitrary isotopic distribution

DOEpatents

Grossman, M.W.; George, W.A.

1986-12-16

This invention provides for a process for preparing mercury with a predetermined, arbitrary, isotopic distribution. In one embodiment, different isotopic types of Hg[sub 2]Cl[sub 2], corresponding to the predetermined isotopic distribution of Hg desired, are placed in an electrolyte solution of HCl and H[sub 2]O. The resulting mercurous ions are then electrolytically plated onto a cathode wire producing mercury containing the predetermined isotopic distribution. In a similar fashion, Hg with a predetermined isotopic distribution is obtained from different isotopic types of HgO. In this embodiment, the HgO is dissolved in an electrolytic solution of glacial acetic acid and H[sub 2]O. The isotopic specific Hg is then electrolytically plated onto a cathode and then recovered. 1 fig.

A mass filter based on an accelerating traveling wave.

PubMed

Wiedenbeck, Michael; Kasemset, Bodin; Kasper, Manfred

2008-01-01

We describe a novel mass filtering concept based on the acceleration of a pulsed ion beam through a stack of electrostatic plates. A precisely controlled traveling wave generated within such an ion guide will induce a mass-selective ion acceleration, with mass separation ultimately accomplished via a simple energy-filtering system. Crucial for successful filtering is that the velocity with which the traveling wave passes through the ion guide must be dynamically controlled in order to accommodate the acceleration of the target ion species. Mass selection is determined by the velocity and acceleration with which the wave traverses the ion guide, whereby the target species will acquire a higher kinetic energy than all other lighter as well as heaver species. Finite element simulations of this design demonstrate that for small masses a mass resolution M/DeltaM approximately 1000 can be achieved within an electrode stack containing as few as 20 plates. Some of the possible advantages and drawbacks which distinguish this concept from established mass spectrometric technologies are discussed.

High-throughput process development: determination of dynamic binding capacity using microtiter filter plates filled with chromatography resin.

PubMed

Bergander, Tryggve; Nilsson-Välimaa, Kristina; Oberg, Katarina; Lacki, Karol M

2008-01-01

Steadily increasing demand for more efficient and more affordable biomolecule-based therapies put a significant burden on biopharma companies to reduce the cost of R&D activities associated with introduction of a new drug to the market. Reducing the time required to develop a purification process would be one option to address the high cost issue. The reduction in time can be accomplished if more efficient methods/tools are available for process development work, including high-throughput techniques. This paper addresses the transitions from traditional column-based process development to a modern high-throughput approach utilizing microtiter filter plates filled with a well-defined volume of chromatography resin. The approach is based on implementing the well-known batch uptake principle into microtiter plate geometry. Two variants of the proposed approach, allowing for either qualitative or quantitative estimation of dynamic binding capacity as a function of residence time, are described. Examples of quantitative estimation of dynamic binding capacities of human polyclonal IgG on MabSelect SuRe and of qualitative estimation of dynamic binding capacity of amyloglucosidase on a prototype of Capto DEAE weak ion exchanger are given. The proposed high-throughput method for determination of dynamic binding capacity significantly reduces time and sample consumption as compared to a traditional method utilizing packed chromatography columns without sacrificing the accuracy of data obtained.

Absolute and angular efficiencies of a microchannel-plate position-sensitive detector

NASA Technical Reports Server (NTRS)

Gao, R. S.; Gibner, P. S.; Newman, J. H.; Smith, K. A.; Stebbings, R. F.

1984-01-01

This paper presents a characterization of a commercially available position-sensitive detector of energetic ions and neutrals. The detector consists of two microchannel plates followed by a resistive position-encoding anode. The work includes measurement of absolute efficiencies of H(+), He(+), and O(+) ions in the energy range between 250 and 5000 eV, measurement of relative detection efficiencies as a function of particle impact angle, and a simple method for accurate measurement of the time at which a particle strikes the detector.

Ionic conductivity, structural deformation, and programmable anisotropy of DNA origami in electric field.

PubMed

Li, Chen-Yu; Hemmig, Elisa A; Kong, Jinglin; Yoo, Jejoong; Hernández-Ainsa, Silvia; Keyser, Ulrich F; Aksimentiev, Aleksei

2015-02-24

The DNA origami technique can enable functionalization of inorganic structures for single-molecule electric current recordings. Experiments have shown that several layers of DNA molecules, a DNA origami plate, placed on top of a solid-state nanopore is permeable to ions. Here, we report a comprehensive characterization of the ionic conductivity of DNA origami plates by means of all-atom molecular dynamics (MD) simulations and nanocapillary electric current recordings. Using the MD method, we characterize the ionic conductivity of several origami constructs, revealing the local distribution of ions, the distribution of the electrostatic potential and contribution of different molecular species to the current. The simulations determine the dependence of the ionic conductivity on the applied voltage, the number of DNA layers, the nucleotide content and the lattice type of the plates. We demonstrate that increasing the concentration of Mg(2+) ions makes the origami plates more compact, reducing their conductivity. The conductance of a DNA origami plate on top of a solid-state nanopore is determined by the two competing effects: bending of the DNA origami plate that reduces the current and separation of the DNA origami layers that increases the current. The latter is produced by the electro-osmotic flow and is reversible at the time scale of a hundred nanoseconds. The conductance of a DNA origami object is found to depend on its orientation, reaching maximum when the electric field aligns with the direction of the DNA helices. Our work demonstrates feasibility of programming the electrical properties of a self-assembled nanoscale object using DNA.

Time-of-flight direct recoil ion scattering spectrometer

DOEpatents

Krauss, A.R.; Gruen, D.M.; Lamich, G.J.

1994-09-13

A time-of-flight direct recoil and ion scattering spectrometer beam line is disclosed. The beam line includes an ion source which injects ions into pulse deflection regions and separated by a drift space. A final optics stage includes an ion lens and deflection plate assembly. The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions. 23 figs.

Rolling contact fatigue behavior of Cu and TiN coatings on bearing steel substrates

NASA Technical Reports Server (NTRS)

Hochman, R. F.; Erdemir, A.; Dolan, F. J.; Thom, R. L.

1985-01-01

The resistance of copper and TiN coatings on various bearing substrates to high-load rolling contact fatigue (RCF) is investigated. Special attention is given to the lubricating characteristics of copper deposited by ion plating, and the wear resistant characteristics of TiN deposited by ion plating and magnetron sputtering techniques. RCF samples of 440C and AMS 5749 bearing steels were coated. Sputter deposited and ion plated films were on the RCF samples in a range of thickness from about 2000 A to 2 microns. Results showed a marked improvement of the RCF for pure copper tested on 440C, but a degradation for copper on AMS 5749. It is also found that the 2000 A TiN films behave favorably on the 440C and AMS 5749 bearing steels at RCF stress levels of 786 ksi. Scanning electron microscopy, X-ray diffraction, and electron spectroscopy for chemical analysis were used during the investigation.

Effects of dithiothreitol on end-plate currents.

PubMed Central

Terrar, D A

1978-01-01

1. End-plate currents have been studied in frog cutaneus pectoris nerve-muscle preparations mounted in continuously flowing solution, using the voltage clamp technique. 2. Exposure of the muscle to 1 mM-dithiothreitol reduced the amplitude of end-plate currents by a factor of 2.7 (mean; range 1.6-3.4; twelve fibres). 3. 1 mM-dithiothreitol also caused a 2.7-fold (2.3-3.1) increase in the rate of decay, and a 1.4-fold (1.3-1.6) decrease in the time to peak of end-plate currents. During the onset of action of dithiothreitol, there was little or no indication of departure of end-plate current decay from a simple exponential. 4. Dithiothreitol actions on amplitude and decay of end-plate currents developed with similar time courses and both effects were slower in onset at pH 7.2 than at pH 8.5. 5. The actions of dithiothreitol were reversed by exposure of the muscle to 1 mM-5,5'-dithio-bis-(2-nitrobenzoic acid). 6. Following dithiothreitol treatment, the rates of decay of end-plate currents continued to depend on membrane potential; there was little or no change in the slope of the relation between in (rate of decay) and membrane potential, consistent with little or no change in the dipole moment of a gating molecule for ion channels. 7. Dithiothreitol changed the relation between peak end-plate current and membrane potential, so that peak conductance increased at more negative membrane potentials; this finding could be accounted for in terms of the closure of ion-channel gates becoming faster though remaining voltage-sensitive after exposure to dithiothreitol. 8. It is concluded that dithiothreitol causes changes in the kinetics of gating of ion channels associated with receptors and that these changes accompany changes in the binding of ACh to receptors. PMID:25960

Tracking rare-isotope beams with microchannel plates

DOE PAGES

Rogers, A. M.; Sanetullaev, A.; Lynch, W. G.; ...

2015-06-06

A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival Limes of ions at the reaction target. Furthermore, the current design is an adaptation of an assembly used for low-energy beams (~1.4 MeV/nucleon). In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1 mm formore » beam intensities up to 5 x 10 5 pps.« less

Tracking rare-isotope beams with microchannel plates

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

Rogers, A. M.; Sanetullaev, A.; Lynch, W. G.

A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival Limes of ions at the reaction target. Furthermore, the current design is an adaptation of an assembly used for low-energy beams (~1.4 MeV/nucleon). In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1 mm formore » beam intensities up to 5 x 10 5 pps.« less

Mass spectrometer calibration of Cosmic Dust Analyzer

NASA Astrophysics Data System (ADS)

Ahrens, Thomas J.; Gupta, Satish C.; Jyoti, G.; Beauchamp, J. L.

2003-02-01

The time-of-flight (TOF) mass spectrometer (MS) of the Cosmic Dust Analyzer (CDA) instrument aboard the Cassini spacecraft is expected to be placed in orbit about Saturn to sample submicrometer-diameter ring particles and impact ejecta from Saturn's satellites. The CDA measures a mass spectrum of each particle that impacts the chemical analyzer sector of the instrument. Particles impact a Rh target plate at velocities of 1-100 km/s and produce some 10-8 to 10-5 times the particle mass of positive valence, single-charged ions. These are analyzed via a TOF MS. Initial tests employed a pulsed N2 laser acting on samples of kamacite, pyrrhotite, serpentine, olivine, and Murchison meteorite induced bursts of ions which were detected with a microchannel plate and a charge sensitive amplifier (CSA). Pulses from the N2 laser (1011 W/cm2) are assumed to simulate particle impact. Using aluminum alloy as a test sample, each pulse produces a charge of ~4.6 pC (mostly Al+1), whereas irradiation of a stainless steel target produces a ~2.8 pC (Fe+1) charge. Thus the present system yields ~10-5% of the laser energy in resulting ions. A CSA signal indicates that at the position of the microchannel plate, the ion detector geometry is such that some 5% of the laser-induced ions are collected in the CDA geometry. Employing a multichannel plate detector in this MS yields for Al-Mg-Cu alloy and kamacite targets well-defined peaks at 24 (Mg+1), 27(Al+1), and 64 (Cu+1) and 56 (Fe+1), 58 (Ni+1), and 60 (Ni+1) dalton, respectively.

Target Plate Material Influence on Fullerene-C60 Laser Desorption/Ionization Efficiency.

PubMed

Zeegers, Guido P; Günthardt, Barbara F; Zenobi, Renato

2016-04-01

Systematic laser desorption/ionization (LDI) experiments of fullerene-C60 on a wide range of target plate materials were conducted to gain insight into the initial ion formation in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The positive and negative ion signal intensities of precursor, fragment, and cluster ions were monitored, varying both the laser fluence (0-3.53 Jcm(-2)) and the ion extraction delay time (0-950 ns). The resulting species-specific ion signal intensities are an indication for the ionization mechanisms that contribute to LDI and the time frames in which they operate, providing insight in the (MA)LDI primary ionization. An increasing electrical resistivity of the target plate material increases the fullerene-C60 precursor and fragment anion signal intensity. Inconel 625 and Ti90/Al6/V4, both highly electrically resistive, provide the highest anion signal intensities, exceeding the cation signal intensity by a factor ~1.4 for the latter. We present a mechanism based on transient electrical field strength reduction to explain this trend. Fullerene-C60 cluster anion formation is negligible, which could be due to the high extraction potential. Cluster cations, however, are readily formed, although for high laser fluences, the preferred channel is formation of precursor and fragment cations. Ion signal intensity depends greatly on the choice of substrate material, and careful substrate selection could, therefore, allow for more sensitive (MA)LDI measurements. Graphical Abstract ᅟ.

Phytofilter - environmental friendly solution for purification of surface plate from urbanized territories

NASA Astrophysics Data System (ADS)

Ruchkinova, O.; Shchuckin, I.

2017-06-01

Its proved, that phytofilters are environmental friendly solution of problem of purification of surface plate from urbanized territories. Phytofilters answer the nowadays purposes to systems of purification of land drainage. The main problem of it is restrictions, connecter with its use in the conditions of cold temperature. Manufactured a technology and mechanism, which provide a whole-year purification of surface plate and its storage. Experimentally stated optimal makeup of filtering load: peat, zeolite and sand in per cent of volume, which provides defined hydraulic characteristics. Stated sorbate and ion-selective volume of complex filtering load of ordered composition in dynamic conditions. Estimated dependences of exit concentrations of oil products and heavy metals on temperature by filtering through complex filtering load of ordered composition. Defined effectiveness of purification at phytofiltering installation. Fixed an influence of embryophytes on process of phytogeneration and capacity of filtering load. Recommended swamp iris, mace reed and reed grass. Manufactured phytofilter calculation methodology. Calculated economic effect from use of phytofiltration technology in comparison with traditional block-modular installations.

Copper circuit patterning on polymer using selective surface modification and electroless plating

NASA Astrophysics Data System (ADS)

Park, Sang Jin; Ko, Tae-Jun; Yoon, Juil; Moon, Myoung-Woon; Oh, Kyu Hwan; Han, Jun Hyun

2017-02-01

We have examined a potential new and simple method for patterning a copper circuit on PET substrate by copper electroless plating, without the pretreatment steps (i.e., sensitization and activation) for electroless plating as well as the etching processes of conventional circuit patterning. A patterned mask coated with a catalyst material, Ag, for the reduction of Cu ions, is placed on a PET substrate. Subsequent oxygen plasma treatment of the PET substrate covered with the mask promotes the selective generation of anisotropic pillar- or hair-like nanostructures coated with co-deposited nanoparticles of the catalyst material on PET. After oxygen plasma treatment, a Cu circuit is well formed just by dipping the plasma-treated PET into a Cu electroless plating solution. By increasing the oxygen gas pressure in the chamber, the height of the nanostructures increases and the Ag catalyst particles are coated on not only the top but also the side surfaces of the nanostructures. Strong mechanical interlocking between the Cu circuit and PET substrate is produced by the large surface area of the nanostructures, and enhances peel strength. Results indicate this new simple two step (plasma surface modification and pretreatment-free electroless plating) method can be used to produce a flexible Cu circuit with good adhesion.

Time-of-flight direct recoil ion scattering spectrometer

DOEpatents

Krauss, Alan R.; Gruen, Dieter M.; Lamich, George J.

1994-01-01

A time of flight direct recoil and ion scattering spectrometer beam line (10). The beam line (10) includes an ion source (12) which injects ions into pulse deflection regions (14) and (16) separated by a drift space (18). A final optics stage includes an ion lens and deflection plate assembly (22). The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions (14) and (16).

Solid-phase materials for chelating metal ions and methods of making and using same

DOEpatents

Harrup, Mason K.; Wey, John E.; Peterson, Eric S.

2003-06-10

A solid material for recovering metal ions from aqueous streams, and methods of making and using the solid material, are disclosed. The solid material is made by covalently bonding a chelating agent to a silica-based solid, or in-situ condensing ceramic precursors along with the chelating agent to accomplish the covalent bonding. The chelating agent preferably comprises a oxime type chelating head, preferably a salicylaldoxime-type molecule, with an organic tail covalently bonded to the head. The hydrocarbon tail includes a carbon-carbon double bond, which is instrumental in the step of covalently bonding the tail to the silica-based solid or the in-situ condensation. The invented solid material may be contacted directly with aqueous streams containing metal ions, and is selective to ions such as copper (II) even in the presence of such ions as iron (III) and other materials that are present in earthen materials. The solid material with high selectivity to copper may be used to recover copper from mining and plating industry streams, to replace the costly and toxic solvent extraction steps of conventional copper processing.

Ion-driven wind: Aerodynamics, performance limits, and optimization

NASA Astrophysics Data System (ADS)

Rickard, Matthew James Alan

When a strong electric field is generated between a sharp, charged object and a grounded electrode in a gas medium, ions that are generated via a corona discharge near the tip of the sharp object migrate to the electrical ground, setting the neutral hulk gas in motion. The strength of the flow generated from such a process; known as a "corona", "ionic", or "ion-driven" wind, increases with electric field until electrical breakdown is reached. Previous studies have found an upper bound on the velocity of the ion-driven wind, even when a series of electrode stages are aggregated. With the intent of maximizing the gas flow front such devices, this dissertation describes a series of experiments that have been conducted and a numerical model that has been employed. Although typical hardware configurations include a wire parallel to a plate, a wire placed concentrically within a cylinder, or a needle facing a perpendicular plate or mesh, the chosen setup for this study is a needle facing a concentric ring. Using multiple experimental techniques and numerical simulation, velocity profiles have been observed at the ring exit and are sensitive to the design of the mounting hardware. The numerical model predicts the ideal electrode geometry for maximizing flow through a single unit. A modular, multi-staged system has been constructed and, when loaded with an exit nozzle, the exit velocity can be substantially increased. Further, if a small-scale (sub-millimeter) system is created, it is expected that the velocity will increase with multi-staging, even in the absence of an exit nozzle.

Screen-Cage Ion Plating Of Silver On Polycrystalline Alumina

NASA Technical Reports Server (NTRS)

Spalvins, Talivaldis; Sliney, Harold E.; Deadmore, Daniel L.

1995-01-01

Screen-cage ion plating (SCIP) cost-effective technique offering high throwing power for deposition of adherent metal films on ceramic substrates. Applies silver films to complexly shaped substrates of polycrystalline alumina. Silver adheres tenaciously and reduces friction. SCIP holds promise for applying lubricating soft metallic films to high-temperature ceramic components of advanced combustion engines. Other potential uses include coating substrates with metal for protection against corrosion, depositing electrical conductors on dielectric substrates, making optically reflective or electrically or thermally conductive surface layers, and applying decorative metal coats to ceramic trophies or sculptures.

Effect of ion-plated films of germanium and silicon on friction, wear, and oxidation of 52100 bearing steel

NASA Technical Reports Server (NTRS)

Buckley, D. H.; Spalvins, T.

1977-01-01

Friction and wear experiments were conducted with ion plated films of germanium and silicon on the surface of 52100 bearing steel both dry and in the presence of mineral oil. Both silicon and germanium were found to reduce wear, with germanium being more effective than silicon. An optimum film thickness of germanium for minimum wear without surface crack formation was found to be approximately 400 nanometers (4000 A). The presence of silicon and germanium on the 52100 bearing steel surface improved resistance to oxidation.

Manufacturing and actuation characterization of ionic polymer metal composites with silver as electrodes

NASA Astrophysics Data System (ADS)

Pandita, Surya D.; Lim, Hyoung Tae; Yoo, Youngtai; Park, Hoon Cheol

2006-03-01

Manufacturing and characterization of ionic polymer metal composites (IPMCs) with silver as electrodes have been investigated. Tollen's reagent that contains ion Ag(NH 3) II + was used as a raw material for silver deposition on the surfaces of the polymer membrane Nafion"R". Two types of inner solvents, namely common water based electrolyte solution (LiOH 1N) and ionic liquid were used and investigated. Compared to IPMCs with platinum electrodes, silver-plated IPMCs with water electrolyte showed higher conductivity. The actuation response of silver-plated IPMCs with the water based electrolyte was faster than that of platinum IPMCs. However, the silver electrode was too brittle and severely damaged during the solvent exchange process from water to ionic liquid, resulted in high resistance and hence very low actuation behavior.

A pepper-pot emittance meter for low-energy heavy-ion beams

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

Kremers, H. R.; Beijers, J. P. M.; Brandenburg, S.

2013-02-15

A novel emittance meter has been developed to measure the four-dimensional, transverse phase-space distribution of a low-energy ion beam using the pepper-pot technique. A characteristic feature of this instrument is that the pepper-pot plate, which has a linear array of holes in the vertical direction, is scanned horizontally through the ion beam. This has the advantage that the emittance can also be measured at locations along the beam line where the beam has a large horizontal divergence. A set of multi-channel plates, scintillation screen, and ccd camera is used as a position-sensitive ion detector allowing a large range of beammore » intensities that can be handled. This paper describes the design, construction, and operation of the instrument as well as the data analysis used to reconstruct the four-dimensional phase-space distribution of an ion beam. Measurements on a 15 keV He{sup +} beam are used as an example.« less

WE-D-BRF-04: Experimental Investigations On Ion Radiography with Beam Scanning Using a Range Telescope

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

Rinaldi, I; Magallanes, L; Ludwig Maximilian University Munich

2014-06-15

Purpose: Ion beams exhibit a finite range and an inverted depth-dose profile, the Bragg peak. These favorable properties allow superior tumordose conformality, but introduce sensitivity to range uncertainties. Hence, imaging techniques play an increasingly important role to support the treatment planning and the in-vivo monitoring of the actual ion beam treatment. Methods: This work presents the experimental investigations carried out to address the feasibility of ion transmission imaging at the Heidelberg Ion Therapy center using an active raster scanning beam delivery system and a prototype range telescope set-up based on a stack of 61 parallel-plate ionization chambers (PPIC) interleaved withmore » 3 mm absorber plates of PMMA. Results: An extensive characterization of the set-up in terms of beam parameters and settings of the read-out electronics was performed and results will be presented. A data processing method to increase the range resolution (MIRR) of the PPIC stack was developed. In this approach, the position of the maximum of the Bragg curve is deduced from the ratio of measured signals in adjacent PPIC channels. MIRR evaluation is based on Bragg curves obtained from Monte Carlo simulations and validated with experimental data acquired with the PPIC stack using ion beams. MIRR was applied to the carbon ion radiography of an anthropomorphic Alderson head phantom yielding a resolution of 0.8 mm water equivalent thickness (WET) compared to the nominal value of 3.495 mm WET given by the thickness of the absorber slabs in the PPIC stack. An absolute comparison of the Alderson phantom carbon ion transmitted image with an X-ray digitally reconstructed radiography, both converted into WET, will also be shown. Conclusion: The obtained results are very promising and motivate further developments of the system towards an eventual clinical use.This work is supported by the German Research Foundation and the German Academic Exchange Service. This work is supported by the German Research Foundation (DFG) and the German Academic Exchange Service (DAAD)« less

High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region.

PubMed

Hirano, Y; Kiyama, S; Fujiwara, Y; Koguchi, H; Sakakita, H

2015-11-01

A high current density (≈3 mA/cm(2)) hydrogen ion beam source operating in an extremely low-energy region (E(ib) ≈ 150-200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E(ib) is being reduced. The radial profiles of the ion beam current density and the low temperature ion current density can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.

Cadmium migration in aerospace nickel cadmium cells

NASA Technical Reports Server (NTRS)

Mcdermott, P. P.

1976-01-01

The effects of temperature, the nature of separator material, charge and discharge, carbonate contamination, and the mode of storage are studied with respect to the migration of active material from the negative toward the positive plate. A theoretical model is proposed which takes into account the solubility of cadmium in various concentrations of hydroxide and carbonate at different temperatures, the generation of the cadmiate ion, Cd(OH)3(-), during discharge, the migration of the cadmiate ion and particulate Cd(OH)2 due to electrophoretic effects and the movement of electrolyte in and out of the negative plate and, finally, the recrystallization of cadmiate ion in the separator as Cd(OH)2. Application of the theoretical model to observations of cadmium migration in cycled cells is also discussed.

High accuracy position response calibration method for a micro-channel plate ion detector

NASA Astrophysics Data System (ADS)

Hong, R.; Leredde, A.; Bagdasarova, Y.; Fléchard, X.; García, A.; Müller, P.; Knecht, A.; Liénard, E.; Kossin, M.; Sternberg, M. G.; Swanson, H. E.; Zumwalt, D. W.

2016-11-01

We have developed a position response calibration method for a micro-channel plate (MCP) detector with a delay-line anode position readout scheme. Using an in situ calibration mask, an accuracy of 8 μm and a resolution of 85 μm (FWHM) have been achieved for MeV-scale α particles and ions with energies of ∼10 keV. At this level of accuracy, the difference between the MCP position responses to high-energy α particles and low-energy ions is significant. The improved performance of the MCP detector can find applications in many fields of AMO and nuclear physics. In our case, it helps reducing systematic uncertainties in a high-precision nuclear β-decay experiment.

Plasma deposition and surface modification techniques for wear resistance

NASA Technical Reports Server (NTRS)

Spalvins, T.

1982-01-01

The ion-assisted or plasma coating technology is discussed as it applies to the deposition of hard, wear resistant refractory compound films. Of the many sputtering and ion plating modes and configurations the reactive magnetron sputtering and the reactive triode ion plating techniques are the preferred ones to deposit wear resistant coatings for tribological applications. Both of these techniques incorporate additional means to enhance the ionization efficiency and chemical reaction to precision tailor desirable tribological characteristics. Interrelationships between film formation, structure, and ribological properties are strictly controlled by the deposition parameters and the substrate condition. The enhanced ionization contributes to the excellent adherence and coherence, reduced internal stresses and improved structural growth to form dense, cohesive, equiaxed grain structure for improved wear resistance and control.

Mechanical stresses and amorphization of ion-implanted diamond

NASA Astrophysics Data System (ADS)

Khmelnitsky, R. A.; Dravin, V. A.; Tal, A. A.; Latushko, M. I.; Khomich, A. A.; Khomich, A. V.; Trushin, A. S.; Alekseev, A. A.; Terentiev, S. A.

2013-06-01

Scanning white light interferometry and Raman spectroscopy were used to investigate the mechanical stresses and structural changes in ion-implanted natural diamonds with different impurity content. The uniform distribution of radiation defects in implanted area was obtained by the regime of multiple-energy implantation of keV He+ ions. A modification of Bosia's et al. (Nucl. Instrum. Meth. B 268 (2010) 2991) method for determining the internal stresses and the density variation in an ion-implanted diamond layer was proposed that suggests measuring, in addition to the surface swelling of a diamond plate, the radius of curvature of the plate. It is shown that, under multiple-energy implantation of He+, mechanical stresses in the implanted layer may be as high as 12 GPa. It is shown that radiation damage reaches saturation for the implantation fluence characteristic of amorphization of diamond but is appreciably lower than the graphitization threshold.

Real time determination of the laser ablated mass by means of electric field-perturbation measurement

NASA Astrophysics Data System (ADS)

Pacheco, P.; Álvarez, J.; Sarmiento, R.; Bredice, F.; Sánchez-Aké, C.; Villagrán-Muniz, M.; Palleschi, V.

2018-04-01

A Nd:YAG ns-pulsed laser was used to ablate Al, Cd and Zn targets, which were placed between the plates of a planar charged capacitor. The plasma generates a transient redistribution of the electrical charges on the plates that can be measured as a voltage drop across a resistor connected to the ground plate. This signal is proportional to the capacitor applied voltage, the distance between the plates and the total number of ions produced in the ablation process which in turn is related to the laser energy and the ablated mass. After a series of pulses, the targets were weighed on a thermogravimetric balance to measure the ablated mass. Our results show that the electrical signal measured on the resistor is univocally related to the ablated mass from the target. Therefore, after a proper calibration depending on the material and the experimental geometry, the electrical signal can be used for real time quantitative measurement of the ablated mass in pulsed laser generated plasma experiments. The experiments were repeated on an aluminum target, with and without the presence of the external electric field in order to determine the possible influence of the applied electric field on the ablated mass.

Presheath and Double Layer Structures in an Argon Helicon Plasma Source

NASA Astrophysics Data System (ADS)

Siddiqui, M. Umair

Ion velocities and temperatures, plasma density, potential, and electron temperatures are measured in a 13.56 MHz helicon produced argon plasma upstream from a grounded plate inside a 10 cm ID cylindrical Pyrex vacuum chamber. The plate is held at psi = 0° → 60° relative to the background axial magnetic field in the system. For the psi = 0° experiment, two distinct helicon discharge equilibria are observed at 500 W rf power, 900 G magnetic field, and a neutral pressure of 3 → 4 mTorr. Both modes exhibit a localized region of hot electrons (Th ≈ 10 eV, Tc ≈ 3.5 eV). For the first mode the hot electrons are confined by a localized potential structure and the density decreases monotonically towards the grounded plate. For the second mode the hot electrons cool off gradually in space due to heat conduction generating a downstream density peak and no major potential structures are observed. It is found that the type of discharge mode is determined by the location of the grounded plate, the length of the presheath, and the rf electron heating mechanism. For the psi = 16° → 60° plate positions, ion flow to the boundary where a 1 kG magnetic field is obliquely incident is measured at 1, 3, and 6.5 mTorr neutral pressure and 450 → 750 W rf power. The results are compared to the magnetic presheath models put forth by Chodura [Phys. Fluids 25, 1628 (1982)], Riemann [Phys. Plasmas 1, 552 (1994)], and Ahedo [Phys. Plasmas 4, 4419 (1997)]. The 1 mTorr dataset is used to benchmark a one-dimensional fluid model for the ion flow in the presheath. Definitions of the "magnetic presheath" are discussed. The fluid model in conjuction with the data show that the ion velocities in the E x B direction can be 10% → 40% percent of the sound speed for the angles investigated. Ion flow to fusion experiment boundaries and Hall thruster walls is discussed.

Modeling, Fabrication and Characterization of Scalable Electroless Gold Plated Nanostructures for Enhanced Surface Plasmon Resonance

NASA Astrophysics Data System (ADS)

Jang, Gyoung Gug

The scientific and industrial demand for controllable thin gold (Au) film and Au nanostructures is increasing in many fields including opto-electronics, photovoltaics, MEMS devices, diagnostics, bio-molecular sensors, spectro-/microscopic surfaces and probes. In this study, a novel continuous flow electroless (CF-EL) Au plating method is developed to fabricate uniform Au thin films in ambient condition. The enhanced local mass transfer rate and continuous deposition resulting from CF-EL plating improved physical uniformity of deposited Au films and thermally transformed nanoparticles (NPs). Au films and NPs exhibited improved optical photoluminescence (PL) and surface plasmon resonance (SPR), respectively, relative to batch immersion EL (BI-EL) plating. Suggested mass transfer models of Au mole deposition are consistent with optical feature of CF-EL and BI-EL films. The prototype CF-EL plating system is upgraded an automated scalable CF-EL plating system with real-time transmission UV-vis (T-UV) spectroscopy which provides the advantage of CF-EL plating, such as more uniform surface morphology, and overcomes the disadvantages of conventional EL plating, such as no continuous process and low deposition rate, using continuous process and controllable deposition rate. Throughout this work, dynamic morphological and chemical transitions during redox-driven self-assembly of Ag and Au film on silica surfaces under kinetic and equilibrium conditions are distinguished by correlating real-time T-UV spectroscopy with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The characterization suggests that four previously unrecognized time-dependent physicochemical regimes occur during consecutive EL deposition of silver (Ag) and Au onto tin-sensitized silica surfaces: self-limiting Ag activation; transitory Ag NP formation; transitional Au-Ag alloy formation during galvanic replacement of Ag by Au; and uniform morphology formation under controlled hydraulic conditions. A method to achieve the time-resolved optical profile of EL Au plating was devised and provided a new transitional EL Au film growth model which validated mass transfer model prediction of the deposited thickness of ≤100 nm thin films. As a part of the project, validation of mass transfer model, a spectrophotometric method for quantitative analysis of metal ion is developed that improves the limit of detection comparable to conventional instrumental analysis. The present work suggests that modeling, fabrication and characterization of this novel CF-EL plating method is performed to achieve an ultimate purpose: developing a reliable, inexpensive wet chemical process for controlled metal thin film and nanostructure fabrication.

Real-time detection of hazardous materials in air

NASA Astrophysics Data System (ADS)

Schechter, Israel; Schroeder, Hartmut; Kompa, Karl L.

1994-03-01

A new detection system has been developed for real-time analysis of organic compounds in ambient air. It is based on multiphoton ionization by an unfocused laser beam in a single parallel-plate device. Thus, the ionization volume can be relatively large. The amount of laser created ions is determined quantitatively from the induced total voltage drop between the biased plates (Q equals (Delta) V(DOT)C). Mass information is obtained from computer analysis of the time-dependent signal. When a KrF laser (5 ev) is used, most of the organic compounds can be ionized in a two-photon process, but none of the standard components of atmospheric air are ionized by this process. Therefore, this instrument may be developed as a `sniffer' for organic materials. The method has been applied for benzene analysis in air. The detection limit is about 10 ppb. With a simple preconcentration technique the detection limit can be decreased to the sub-ppb range. Simple binary mixtures are also resolved.

CALUTRON ASSEMBLING AND DISASSEMBLING APPARATUS

DOEpatents

Andrews, R.E.

1959-01-27

The construction of a calutron tank is described, whcre the face plate of the tank carrying the ion separating mechanism may be inserted or withdrawn with a minimum of difficulty, even though the plate has considerable mass and the center of gravity of the plate assembly lies within the tank. In general, the plate is pivoted at its lower end by a specially designed hinge, whereby the weight of ths plate rests on the hinge when the plato is inserted in the tank opening. A pistoncylinder arrangement is mounted on the tank and attached at the top of the plate to produce sufficient force to pivot the plate out to a point where it withdraws by its own weight and to retard the natural tendency of the plate to close with heavy impact due to the unbalanced center of gravity of the plate assembly.

Quantitative analysis of major dibenzocyclooctane lignans in Schisandrae fructus by online TLC-DART-MS.

PubMed

Kim, Hye Jin; Oh, Myung Sook; Hong, Jongki; Jang, Young Pyo

2011-01-01

Direct analysis in real time (DART) ion source is a powerful ionising technique for the quick and easy detection of various organic molecules without any sample preparation steps, but the lack of quantitation capacity limits its extensive use in the field of phytochemical analysis. To improvise a new system which utilize DART-MS as a hyphenated detector for quantitation. A total extract of Schisandra chinensis fruit was analyzed on a TLC plate and three major lignan compounds were quantitated by three different methods of UV densitometry, TLC-DART-MS and HPLC-UV to compare the efficiency of each method. To introduce the TLC plate into the DART ion source at a constant velocity, a syringe pump was employed. The DART-MS total ion current chromatogram was recorded for the entire TLC plate. The concentration of each lignan compound was calculated from the calibration curve established with standard compound. Gomisin A, gomisin N and schisandrin were well separated on a silica-coated TLC plate and the specific ion current chromatograms were successfully acquired from the TLC-DART-MS system. The TLC-DART-MS system for the quantitation of natural products showed better linearity and specificity than TLC densitometry, and consumed less time and solvent than conventional HPLC method. A hyphenated system for the quantitation of phytochemicals from crude herbal drugs was successfully established. This system was shown to have a powerful analytical capacity for the prompt and efficient quantitation of natural products from crude drugs. Copyright © 2010 John Wiley & Sons, Ltd.

Manufacturing and Performance Assessment of Stamped, Laser Welded, and Nitrided FeCrV Stainless Steel Bipolar Plates for Proton Exchange Membrane Fuel Cells

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

Brady, Michael P; Abdelhamid, Mahmoud; Dadheech, G

A manufacturing and single-cell fuel cell performance study of stamped, laser welded, and gas nitrided ferritic stainless steel foils in an advanced automotive bipolar plate assembly design was performed. Two developmental foil compositions were studied: Fee20Cre4V and Fee23Cre4V wt.%. Foils 0.1 mm thick were stamped and then laser welded together to create single bipolar plate assemblies with cooling channels. The plates were then surface treated by pre-oxidation and nitridation in N2e4H2 based gas mixtures using either a conventional furnace or a short-cycle quartz lamp infrared heating system. Single-cell fuel cell testing was performed at 80 C for 500 h atmore » 0.3 A/cm2 using 100% humidification and a 100%/40% humidification cycle that stresses the membrane and enhances release of the fluoride ion and promotes a more corrosive environment for the bipolar plates. Periodic high frequency resistance potential-current scans during the 500 h fuel cell test and posttest analysis of the membrane indicated no resistance increase of the plates and only trace levels of metal ion contamination.« less

Application of modern surface analytical tools in the investigation of surface deterioration processes

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1983-01-01

Surface profilometry and scanning electron microscopy were utilized to study changes in the surface of polymers when eroded. The X-ray photoelectron spectroscopy (XPS) and depth profile analysis indicate the corrosion of metal and ceramic surfaces and reveal the diffusion of certain species into the surface to produce a change in mechanical properties. Ion implantation, nitriding and plating and their effects on the surface are characterized. Auger spectroscopy analysis identified morphological properties of coatings applied to surfaces by sputter deposition.

The Deflection Plate Analyzer: A Technique for Space Plasma Measurements Under Highly Disturbed Conditions

NASA Technical Reports Server (NTRS)

Wright, Kenneth H., Jr.; Dutton, Ken; Martinez, Nelson; Smith, Dennis; Stone, Nobie H.

2004-01-01

A technique has been developed to measure the characteristics of space plasmas under highly disturbed conditions; e.g., non-Maxwellian plasmas with strong drifting populations and plasmas contaminated by spacecraft outgassing. The present method is an extension of the capabilities of the Differential Ion Flux Probe (DIFP) to include a mass measurement that does not include either high voltage or contamination sensitive devices such as channeltron electron multipliers or microchannel plates. This reduces the complexity and expense of instrument fabrication, testing, and integration of flight hardware as compared to classical mass analyzers. The new instrument design is called the Deflection Plate Analyzer (DPA) and can deconvolve multiple ion streams and analyze each stream for ion flux intensity (density), velocity (including direction of motion), mass, and temperature (or energy distribution). The basic functionality of the DPA is discussed. The performance characteristics of a flight instrument as built for an electrodynamic tether mission, the Propulsive Small Expendable Deployer System (ProSEDS), and the instrument s role in measuring key experimental conditions are also discussed.

The Deflection Plate Analyzer: A Technique for Space Plasma Measurements Under Highly Disturbed Conditions

NASA Technical Reports Server (NTRS)

Wright, Kenneth H., Jr.; Dutton, Ken; Martinez, Nelson; Smith, Dennis; Stone, Nobie H.

2003-01-01

A technique has been developed to measure the characteristics of space plasmas under highly disturbed conditions; e.g., non-Maxwellian plasmas with strong drifting populations and plasmas contaminated by spacecraft outgassing. The present method is an extension of the capabilities of the Differential Ion Flux Probe (DIFP) to include a mass measurement that does not include either high voltage or contamination sensitive devices such as channeltron electron multipliers or microchannel plates. This reduces the complexity and expense of instrument fabrication, testing, and integration of flight hardware as compared to classical mass analyzers. The new instrument design is called the Deflection Plate Analyzer (DPA) and can deconvolve multiple ion streams and analyze each stream for ion flux intensity (density), velocity (including direction of motion), mass, and temperature (or energy distribution). The basic functionality of the DPA is discussed. The performance characteristics of a flight instrument as built for an electrodynamic tether mission, the Propulsive Small Expendable Deployer System (ProSEDS), and the instrument s role in measuring key experimental conditions are also discussed.

Rapid determination of trace copper in animal feed based on micro-plate colorimetric reaction and statistical partitioning correction.

PubMed

Niu, Yiming; Wang, Jiayi; Zhang, Chi; Chen, Yiqiang

2017-04-15

The objective of this study was to develop a micro-plate based colorimetric assay for rapid and high-throughput detection of copper in animal feed. Copper ion in animal feed was extracted by trichloroacetic acid solution and reduced to cuprous ion by hydroxylamine. The cuprous ion can chelate with 2,2'-bicinchoninic acid to form a Cu-BCA complex which was detected with high sensitivity by micro-plate reader at 354nm. The whole assay procedure can be completed within 20min. To eliminate matrix interference, a statistical partitioning correction approach was proposed, which makes the detection of copper in complex samples possible. The limit of detection was 0.035μg/mL and the detection range was 0.1-10μg/mL of copper in buffer solution. Actual sample analysis indicated that this colorimetric assay produced results consistent with atomic absorption spectrometry analysis. These results demonstrated that the developed assay can be used for rapid determination of copper in animal feed. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Stabilized Finite Element Method for Modified Poisson-Nernst-Planck Equations to Determine Ion Flow Through a Nanopore

PubMed Central

Chaudhry, Jehanzeb Hameed; Comer, Jeffrey; Aksimentiev, Aleksei; Olson, Luke N.

2013-01-01

The conventional Poisson-Nernst-Planck equations do not account for the finite size of ions explicitly. This leads to solutions featuring unrealistically high ionic concentrations in the regions subject to external potentials, in particular, near highly charged surfaces. A modified form of the Poisson-Nernst-Planck equations accounts for steric effects and results in solutions with finite ion concentrations. Here, we evaluate numerical methods for solving the modified Poisson-Nernst-Planck equations by modeling electric field-driven transport of ions through a nanopore. We describe a novel, robust finite element solver that combines the applications of the Newton's method to the nonlinear Galerkin form of the equations, augmented with stabilization terms to appropriately handle the drift-diffusion processes. To make direct comparison with particle-based simulations possible, our method is specifically designed to produce solutions under periodic boundary conditions and to conserve the number of ions in the solution domain. We test our finite element solver on a set of challenging numerical experiments that include calculations of the ion distribution in a volume confined between two charged plates, calculations of the ionic current though a nanopore subject to an external electric field, and modeling the effect of a DNA molecule on the ion concentration and nanopore current. PMID:24363784

Models, assumptions, and experimental tests of flows near boundaries in magnetized plasmas

NASA Astrophysics Data System (ADS)

Siddiqui, M. Umair; Thompson, Derek S.; Jackson, Cory D.; Kim, Justin F.; Hershkowitz, Noah; Scime, Earl E.

2016-05-01

We present the first measurements of ion flows in three dimensions (3Ds) using laser-induced fluorescence in the plasma boundary region. Measurements are performed upstream from a grounded stainless steel limiter plate at various angles ( ψ=16 ° to 80 ° ) to the background magnetic field in two argon helicon experiments (MARIA at the University of Wisconsin-Madison and HELIX at West Virginia University). The Chodura magnetic presheath model for collisionless plasmas [R. Chodura, Phys. Fluids 25, 1628 (1982)] is shown to be inaccurate for systems with sufficient ion-neutral collisions and ionization such as tokamak scrape off layers. A 3D ion fluid model that accounts for ionization and charge-exchange collisions is found to accurately describe the measured ion flows in regions where the ion flux tubes do not intersect the boundary. Ion acceleration in the E →×B → direction is observed within a few ion Larmor radii of the grounded plate for ψ=80 ° . We argue that fully 3D ion and neutral acceleration in the plasma boundary are uniquely caused by the long-range presheath electric fields, and that models that omit presheath effects under-predict observed wall erosion in tokamak divertors and Hall thruster channel walls.

Ionospheric plasma flow about a system of electrically biased flat plates. M.S. Thesis - Cleveland State Univ. Final Report

NASA Technical Reports Server (NTRS)

Herr, Joel L.

1993-01-01

The steady state interaction of two electrically biased parallel plates immersed in a flowing plasma characteristic of low earth orbit is studied numerically. Fluid equations are developed to describe the motion of the cold positively charged plasma ions, and are solved using finite-differences in two dimensions on a Cartesian grid. The behavior of the plasma electrons is assumed to be described by the Maxwell-Boltzmann distribution. Results are compared to an analytical and a particle simulation technique for a simplified flow geometry consisting of a single semi-infinite negatively biased plate. Comparison of the extent of the electrical disturbance into the flowing plasma and the magnitude of the current collected by the plate is very good. The interaction of two equally biased parallel plates is studied as a function of applied potential. The separation distance at which the current collected by either plate decreases by five and twenty percent is determined as a function of applied potential. The percent decreases were based on a non-interacting case. The decrease in overall current is caused by a decrease in ionic density in the region between the plates. As the separation between the plates decreases, the plates collect the ions at a faster rate than they are supplied to the middle region by the oncoming plasma flow. The docking of spacecraft in orbit is simulated by moving two plates of unequal potential toward one another in a quasi-static manner. One plate is held at a large negative potential while the other floats electrically in the resulting potential field. It is found that the floating plate does not charge continuously negative as it approaches the other more negatively biased plate. Instead, it charges more and then less negative as ionic current decreases and then increases respectively upon approach. When the two plates come into contact, it is expected that the electrically floating plate will charge rapidly negative to a potential near that of the other plate.

Size and Charge Dependence of Ion Transport in Human Nail Plate

PubMed Central

Baswan, Sudhir M.; Li, S. Kevin; LaCount, Terri D.; Kasting, Gerald B.

2016-01-01

The electrical properties of human nail plate are poorly characterized, yet are a key determinate of the potential to treat nail diseases such as onychomycosis using iontophoresis. In order to address this deficiency, molar conductivities of 17 electrolytes comprising 12 ionic species were determined in hydrated human nail plate in vitro. Cation transport numbers across the nail for 11 of these electrolytes were determined by the electromotive force method. Effective ionic mobilities and diffusivities at infinite dilution for all ionic species were determined by regression analysis. The ratios of diffusivities in nail to those in solution were found to correlate inversely with the hydrodynamic radii of the ions according to a power law relationship having an exponent of −1.75 ± 0.27, a substantially steeper size dependence than observed for similar experiments in skin. Effective diffusivities of cations in nail were three-fold higher than those of comparably sized anions. These results reflect the strong size and charge selectivity of the nail plate for ionic conduction and diffusion. The analysis implies that efficient transungual iontophoretic delivery of ionized drugs having radii upwards of 5 Å (approximately MW ≥ 340 Da) will require chemical or mechanical alteration of the nail plate. PMID:26886342

Ionic Conductivity, Structural Deformation and Programmable Anisotropy of DNA Origami in Electric Field

PubMed Central

Li, Chen-Yu; Hemmig, Elisa A.; Kong, Jinglin; Yoo, Jejoong; Hernández-Ainsa, Silvia

2015-01-01

The DNA origami technique can enable functionalization of inorganic structures for single-molecule electric current recordings. Experiments have shown that several layers of DNA molecules—a DNA origami plate— placed on top of a solid-state nanopore is permeable to ions. Here, we report a comprehensive characterization of the ionic conductivity of DNA origami plates by means of all-atom molecular dynamics (MD) simulations and nanocapillary electric current recordings. Using the MD method, we characterize the ionic conductivity of several origami constructs, revealing the local distribution of ions, the distribution of the electrostatic potential and contribution of different molecular species to the current. The simulations determine the dependence of the ionic conductivity on the applied voltage, the number of DNA layers, the nucleotide content and the lattice type of the plates. We demonstrate that increasing the concentration of Mg2+ ions makes the origami plates more compact, reducing their conductivity. The conductance of a DNA origami plate on top of a solid-state nanopore is determined by the two competing effects: bending of the DNA origami plate that reduces the current and separation of the DNA origami layers that increases the current. The latter is produced by the electro-osmotic flow and is reversible at the time scale of a hundred nanoseconds. The conductance of a DNA origami object is found to depend on its orientation, reaching maximum when the electric field aligns with the direction of the DNA helices. Our work demonstrates feasibility of programming the electrical properties of a self-assembled nanoscale object using DNA. PMID:25623807

Method for plating with metal oxides

DOEpatents

Silver, Gary L.; Martin, Frank S.

1994-08-23

A method of plating hydrous metal oxides on at least one substrate, which method is indifferent to the electrochemical properties of the substrate, and comprises reacting metallic ions in aqueous solution with an appropriate oxidizing agent such as sodium hypochlorite or calcium sulfite with oxygen under suitable conditions of pH and concentration such that oxidation and precipitation of metal oxide are sufficiently slow to allow satisfactory plating of metal oxide on the substrate.

Detection of Large Ions in Time-of-Flight Mass Spectrometry: Effects of Ion Mass and Acceleration Voltage on Microchannel Plate Detector Response

NASA Astrophysics Data System (ADS)

Liu, Ranran; Li, Qiyao; Smith, Lloyd M.

2014-08-01

In time-of-flight mass spectrometry (TOF-MS), ion detection is typically accomplished by the generation and amplification of secondary electrons produced by ions colliding with a microchannel plate (MCP) detector. Here, the response of an MCP detector as a function of ion mass and acceleration voltage is characterized, for singly charged peptide/protein ions ranging from 1 to 290 kDa in mass, and for acceleration voltages from 5 to 25 kV. A nondestructive inductive charge detector (ICD) employed in parallel with MCP detection provides a reliable reference signal to allow accurate calibration of the MCP response. MCP detection efficiencies were very close to unity for smaller ions at high acceleration voltages (e.g., angiotensin, 1046.5 Da, at 25 kV acceleration voltage), but decreased to ~11% for the largest ions examined (immunoglobulin G (IgG) dimer, 290 kDa) even at the highest acceleration voltage employed (25 kV). The secondary electron yield γ (average number of electrons produced per ion collision) is found to be proportional to mv3.1 (m: ion mass, v: ion velocity) over the entire mass range examined, and inversely proportional to the square root of m in TOF-MS analysis. The results indicate that although MCP detectors indeed offer superlative performance in the detection of smaller peptide/protein species, their performance does fall off substantially for larger proteins, particularly under conditions of low acceleration voltage.

High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region

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

Hirano, Y., E-mail: y.hirano@aist.go.jp, E-mail: hirano.yoichi@phys.cst.nihon-u.ac.jp; College of Science and Technologies, Nihon University, Chiyodaku, Tokyo 101-0897; Kiyama, S.

2015-11-15

A high current density (≈3 mA/cm{sup 2}) hydrogen ion beam source operating in an extremely low-energy region (E{sub ib} ≈ 150–200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E{sub ib} is being reduced. The radial profiles of the ion beam current density and the low temperature ion current densitymore » can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.« less

Nickel hexacyanoferrate, a versatile intercalation host for divalent ions from nonaqueous electrolytes

NASA Astrophysics Data System (ADS)

Lipson, Albert L.; Han, Sang-Don; Kim, Soojeong; Pan, Baofei; Sa, Niya; Liao, Chen; Fister, Timothy T.; Burrell, Anthony K.; Vaughey, John T.; Ingram, Brian J.

2016-09-01

New energy storage chemistries based on Mg ions or Ca ions can theoretically improve both the energy density and reduce the costs of batteries. To date there has been limited progress in implementing these systems due to the challenge of finding a high voltage high capacity cathode that is compatible with an electrolyte that can plate and strip the elemental metal. In order to accelerate the discovery of such a system, model systems are needed that alleviate some of the issues of incompatibility. This report demonstrates the ability of nickel hexacyanoferrate to electrochemically intercalate Mg, Ca and Zn ions from a nonaqueous electrolyte. This material has a relatively high insertion potential and low overpotential in the electrolytes used in this study. Furthermore, since it is not an oxide based cathode it should be able to resist attack by corrosive electrolytes such as the chloride containing electrolytes that are often used to plate and strip magnesium. This makes it an excellent cathode for use in developing and understanding the complex electrochemistry of multivalent ion batteries.

Nickel hexacyanoferrate, a versatile intercalation host for divalent ions from nonaqueous electrolytes

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

Lipson, Albert L.; Han, Sang-Don; Kim, Soojeong

2016-09-01

New energy storage chemistries based on Mg ions or Ca ions can theoretically improve both the energy density and reduce the costs of batteries. To date there has been limited progress in implementing these systems due to the challenge of finding a high voltage high capacity cathode that is compatible with an electrolyte that can plate and strip the elemental metal. In order to accelerate the discovery of such a system, model systems are needed that alleviate some of the issues of incompatibility. This report demonstrates the ability of nickel hexacyanoferrate to electrochemically intercalate Mg, Ca and Zn ions frommore » a nonaqueous electrolyte. This material has a relatively high insertion potential and low overpotential in the electrolytes used in this study. Furthermore, since it is not an oxide based cathode it should be able to resist attack by corrosive electrolytes such as the chloride containing electrolytes that are often used to plate and strip magnesium. This makes it an excellent cathode for use in developing and understanding the complex electrochemistry of multivalent ion batteries.« less

Imaging and Rapid-Scanning Ion Mass Spectrometer (IRM) for the CASSIOPE e-POP Mission

NASA Astrophysics Data System (ADS)

Yau, Andrew W.; Howarth, Andrew; White, Andrew; Enno, Greg; Amerl, Peter

2015-06-01

The imaging and rapid-scanning ion mass spectrometer (IRM) is part of the Enhanced Polar Outflow Probe (e-POP) instrument suite on the Canadian CASSIOPE small satellite. Designed to measure the composition and detailed velocity distributions of ions in the ˜1-100 eV/q range on a non-spinning spacecraft, the IRM sensor consists of a planar entrance aperture, a pair of electrostatic deflectors, a time-of-flight (TOF) gate, a hemispherical electrostatic analyzer, and a micro-channel plate (MCP) detector. The TOF gate measures the transit time of each detected ion inside the sensor. The hemispherical analyzer disperses incident ions by their energy-per-charge and azimuth in the aperture plane onto the detector. The two electrostatic deflectors may be optionally programmed to step through a sequence of deflector voltages, to deflect ions of different incident elevation out of the aperture plane and energy-per-charge into the sensor aperture for sampling. The position and time of arrival of each detected ion at the detector are measured, to produce an image of 2-dimensional (2D), mass-resolved ion velocity distribution up to 100 times per second, or to construct a composite 3D velocity distribution by combining successive images in a deflector voltage sequence. The measured distributions are then used to investigate ion composition, density, drift velocity and temperature in polar ion outflows and related acceleration and transport processes in the topside ionosphere.

Highly charged ion secondary ion mass spectroscopy

DOEpatents

Hamza, Alex V.; Schenkel, Thomas; Barnes, Alan V.; Schneider, Dieter H.

2001-01-01

A secondary ion mass spectrometer using slow, highly charged ions produced in an electron beam ion trap permits ultra-sensitive surface analysis and high spatial resolution simultaneously. The spectrometer comprises an ion source producing a primary ion beam of highly charged ions that are directed at a target surface, a mass analyzer, and a microchannel plate detector of secondary ions that are sputtered from the target surface after interaction with the primary beam. The unusually high secondary ion yield permits the use of coincidence counting, in which the secondary ion stops are detected in coincidence with a particular secondary ion. The association of specific molecular species can be correlated. The unique multiple secondary nature of the highly charged ion interaction enables this new analytical technique.

The development of self-expanding peripheral stent with ion-modified surface layer

NASA Astrophysics Data System (ADS)

Lotkov, Alexander I.; Kashin, Oleg A.; Kudryashov, Andrey N.; Krukovskii, Konstantin V.; Kuznetsov, Vladimir M.; Borisov, Dmitry P.; Kretov, Evgenii I.

2016-11-01

In work researches of chemical composition of surface layers of self-expanding stents of nickel-titanium (NiTi) and their functional and mechanical properties after plasma immersion processing by ions of silicon (Si). It is established that in the treatment in the inner and outer surfaces of stents formed doped silicon layer with a thickness of 80 nm. The formation of the doped layer does not impair the functional properties of the stent. At human body temperature, the stent is fully restore its shape after removing the deforming load. The resulting graph of loading of stents during their compression between parallel plates. The research results allow the conclusion that Si-doped stents are promising for treatment of peripheral vascular disease. However, related studies on laboratory animals are required.

A novel electrostatic ion-energy spectrometer by the use of a proposed ``self-collection'' method for secondary-electron emission from a metal collector

NASA Astrophysics Data System (ADS)

Hirata, M.; Nagashima, S.; Cho, T.; Kohagura, J.; Yoshida, M.; Ito, H.; Numakura, T.; Minami, R.; Kondoh, T.; Nakashima, Y.; Yatsu, K.; Miyoshi, S.

2003-03-01

For the purpose of end-loss-ion energy analyses in open-field plasmas, a newly developed electrostatic ion-energy spectrometer is proposed on the basis of a "self-collection" principle for secondary-electron emission from a metal collector. The ion-energy spectrometer is designed with multiple grids for analyzing incident ion energies, and a set of parallelly placed metal plates with respect to lines of ambient magnetic forces in an open-ended device. One of the most important characteristic properties of this spectrometer is the use of our proposed principle of a "self-collection" mechanism due to E×B drifts for secondary electrons emitted from the grounded metal-plate collector by the use of no further additional magnetic systems except the ambient open-ended fields B. The proof-of-principle and characterization experiments are carried out by the use of a test-ion-beam line along with an additional use of a Helmholtz coil system for the formation of open magnetic fields similar to those in the GAMMA 10 end region. The applications of the developed ion-energy spectrometer for end-loss-ion diagnostics in the GAMMA 10 plasma experiments are demonstrated under the conditions with simultaneous incidence of energetic electrons produced by electron-cyclotron heatings for end-loss-plugging potential formation, since these electrons have contributed to disturb these ion signals from conventional end-loss-ion detectors.

Method for plating with metal oxides

DOEpatents

Silver, G.L.; Martin, F.S.

1994-08-23

A method is disclosed of plating hydrous metal oxides on at least one substrate, which method is indifferent to the electrochemical properties of the substrate, and comprises reacting metallic ions in aqueous solution with an appropriate oxidizing agent such as sodium hypochlorite or calcium sulfite with oxygen under suitable conditions of pH and concentration such that oxidation and precipitation of metal oxide are sufficiently slow to allow satisfactory plating of metal oxide on the substrate. 1 fig.

CLOSED-LOOP TREATMENT OF ELECTROLYTIC AND ELECTROLESS NICKEL RINSE WATER BY POINT-OF-USE ION EXCHANGE: A CASE STUDY

EPA Science Inventory

Many recent pilot tests have demonstrated the benefits and cost effectiveness of point-of-use treatment technologies as opposed to centralized wastewater treatment for all sizes of plating facilities. A 9-month case study at a small plating facility in Cincinnati, OH utilizing po...

Structure and properties of TiSiCN coatings with different bias voltages by arc ion plating

NASA Astrophysics Data System (ADS)

Xie, Xinming; Li, Jinlong; Dong, Minpeng; Zhang, Henghua; Wang, Liping

2018-03-01

TiSiCN coatings were deposited on 316 L steel using the multi-arc ion plating system. All the coatings had the same total thickness of approximately 1.6 µm. The TiSiCN coatings were deposited under the mixture constant flow of N2 and C2H2 but varying bias. Information about structures, composition and properties were characterized by scanning electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, nanoindentation and ball-on-plate wear tests. The results show that all of the coatings consist of a TiCN nano-crystal phase and an Si3N4 amorphous phase. With an increase in the bias, the film becomes denser and exhibits better tribological behavior and mechanical properties. Moreover, the bonding strength between the coatings and the substrate increased and the resistance to thermal shock intensified when the coatings were made at a higher bias voltage.

Removal of cationic pollutants from water by xanthated corn cob: optimization, kinetics, thermodynamics, and prediction of purification process.

PubMed

Kostić, Miloš; Đorđević, Miloš; Mitrović, Jelena; Velinov, Nena; Bojić, Danijela; Antonijević, Milan; Bojić, Aleksandar

2017-07-01

The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second-order and Chrastil's model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g -1 for Cr(III) ions and MB, respectively, was obtained at 40 °C, pH 5, and sorbent dose 4 g dm -3 for removal of Cr(III) ions and 1 g dm -3 for removal of MB. The prediction of purification process was successfully carried out, and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e., after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm -3 . Also, removal of MB from the river water was successfully carried out and after 40 min, removal efficiency was about 94%.

Anion Effects on the Ion Exchange Process and the Deformation Property of Ionic Polymer Metal Composite Actuators

PubMed Central

Aoyagi, Wataru; Omiya, Masaki

2016-01-01

An ionic polymer-metal composite (IPMC) actuator composed of a thin perfluorinated ionomer membrane with electrodes plated on both surfaces undergoes a large bending motion when a low electric field is applied across its thickness. Such actuators are soft, lightweight, and able to operate in solutions and thus show promise with regard to a wide range of applications, including MEMS sensors, artificial muscles, biomimetic systems, and medical devices. However, the variations induced by changing the type of anion on the device deformation properties are not well understood; therefore, the present study investigated the effects of different anions on the ion exchange process and the deformation behavior of IPMC actuators with palladium electrodes. Ion exchange was carried out in solutions incorporating various anions and the actuator tip displacement in deionized water was subsequently measured while applying a step voltage. In the step voltage response measurements, larger anions such as nitrate or sulfate led to a more pronounced tip displacement compared to that obtained with smaller anions such as hydroxide or chloride. In AC impedance measurements, larger anions generated greater ion conductivity and a larger double-layer capacitance at the cathode. Based on these mechanical and electrochemical measurements, it is concluded that the presence of larger anions in the ion exchange solution induces a greater degree of double-layer capacitance at the cathode and results in enhanced tip deformation of the IPMC actuators. PMID:28773599

THOR Ion Mass Spectrometer (IMS)

NASA Astrophysics Data System (ADS)

Retinò, Alessandro

2017-04-01

Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. The Ion Mass Spectrometer (IMS) onboard THOR will provide the first high-time resolution measurements of mass-resolved ions in near-Earth space, focusing on hot ions in the foreshock, shock and magnetosheath turbulent regions. These measurements are required to study how kinetic-scale turbulent fluctuations heat and accelerate different ion species. IMS will measure the full three-dimensional distribution functions of main ion species (H+, He++, O+) in the energy range 10 eV/q to 30 keV/q with energy resolution DE/E down to 10% and angular resolution down to 11.25˚ . The time resolution will be 150 ms for O+, 300 ms for He++ and ˜ 1s for O+, which correspond to ion scales in the the foreshock, shock and magnetosheath regions. Such high time resolution is achieved by mounting four identical IMS units phased by 90˚ in the spacecraft spin plane. Each IMS unit combines a top-hat electrostatic analyzer with deflectors at the entrance together with a time-of-flight section to perform mass selection. Adequate mass-per-charge resolution (M/q)/(ΔM/q) (≥ 8 for He++ and ≥ 3 for O+) is obtained through a 6 cm long Time-of-Flight (TOF) section. IMS electronics includes a fast sweeping high voltage board that is required to make measurements at high cadence. Ion detection includes Micro Channel Plates (MCPs) combined with Application-Specific Integrated Circuits (ASICs) for charge amplification and discrimination and a discrete Time-to-Amplitude Converter (TAC) to determine the ion time of flight. A processor board will be used to for ion events formatting and will interface with the Particle Processing Unit (PPU), which will perform data processing for THOR particle detectors. The IMS instrument is being designed and will be built and calibrated by an international consortium of scientific institutes from France, USA, Germany and Japan and Switzerland.

Single-ring magnetic cusp low gas pressure ion source

DOEpatents

Bacon, Frank M.; Brainard, John P.; O'Hagan, James B.; Walko, Robert J.

1985-01-01

A single-ring magnetic cusp low gas pressure ion source designed for use in a sealed, nonpumped neutron generator utilizes a cathode and an anode, three electrically floating electrodes (a reflector behind the cathode, a heat shield around the anode, and an aperture plate), together with a single ring-cusp magnetic field, to establish and energy-filtering mechanism for producing atomic-hydrogen ions.

Sputter-ion plating of coatings for protection of gas-turbine blades against high-temperature oxidation and corrosion

NASA Technical Reports Server (NTRS)

Coad, J. P.; Restall, J. E.

1982-01-01

Considerable effort is being devoted to the development of overlay coatings for protecting critical components such as turbine blades against high-temperature oxidation, corrosion, and erosion damage in service. The most commercially advanced methods for depositing coatings are electron-beam evaporation and plasma spraying. Sputter-ion plating (SIP) offers a potentially cheaper and simpler alternative method for depositing overlays. Experimental work on SIP of Co-Cr-Al-Y and Ni-Cr-Al-Ti alloy coatings is described. Results are presented of metallographic assessment of these coatings, and of the results obtained from high-velocity testing using a gas-turbine simulator rig.

Time resolution of resistive plate chambers investigated with 10 MeV electrons

NASA Astrophysics Data System (ADS)

Paradela, C.; Ayyad, Y.; Benlliure, J.; Casarejos, E.; Duran, I.

2014-01-01

The time resolution of double-gap timing resistive plate chambers (tRPC) has been measured with 10 MeV electron bunches of variable intensity. The use of electrons delivered in bunches of a few picoseconds was an attempt to mimic the energy deposition of heavy ions in the tRPC gas gap. The measurements show a clear dependence of the time resolution with the number of electrons per bunch, reaching 21 ps (standard deviation) for the highest beam intensity. The signal charge distribution and the time resolution are compared to data obtained with the same detectors for cosmic rays and 238U ions at 1 AGeV.

Size and Charge Dependence of Ion Transport in Human Nail Plate.

PubMed

Baswan, Sudhir M; Li, S Kevin; LaCount, Terri D; Kasting, Gerald B

2016-03-01

The electrical properties of human nail plate are poorly characterized yet are a key determinate of the potential to treat nail diseases, such as onychomycosis, using iontophoresis. To address this deficiency, molar conductivities of 17 electrolytes comprising 12 ionic species were determined in hydrated human nail plate in vitro. Cation transport numbers across the nail for 11 of these electrolytes were determined by the electromotive force method. Effective ionic mobilities and diffusivities at infinite dilution for all ionic species were determined by regression analysis. The ratios of diffusivities in nail to those in solution were found to correlate inversely with the hydrodynamic radii of the ions according to a power law relationship having an exponent of -1.75 ± 0.27, a substantially steeper size dependence than observed for similar experiments in skin. Effective diffusivities of cations in nail were 3-fold higher than those of comparably sized anions. These results reflect the strong size and charge selectivity of the nail plate for ionic conduction and diffusion. The analysis implies that efficient transungual iontophoretic delivery of ionized drugs having radii upward of 5 Å (molecular weight, ca. ≥ 340 Da) will require chemical or mechanical alteration of the nail plate. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Armor-Rolled: Metallurgical Examination of British Homogenous and Face Hardened Armor

DTIC Science & Technology

1945-02-10

Brinell Mtgr. ,.nd of Thickness Hardness Type Composition Iom. T~ektesg Plate Inches MM. Face Core C Mn Ni "r Mo V "E.S.Co., 70mm. Homo. 2.74 69.6...the above analyses are used for projectile testing plate, but only the composition from which the Firth Brown 12O)mm. plate wrn frbricated is knuwn...satisfactory steel soundness in regard to freedom from pronounced laminat ions. Bevere segrega~tions of small ovJ. shaped nonmetvallic inclusions

The Theory for the Mechanism of Chromium Plating: The Theory for the Physical Characteristics of Chromium Plate

DTIC Science & Technology

1947-01-01

first, to produce a cathode film containing highly reducing atomic hydro- gen, and, second , to raise the cathode film pH above that of the solution...those of a face-centered cubic structure with a lattice parameter (a0) of 3.84 A. It was concluded that a second unstable structure of chrom- ium...plates similar to those produced from cathode films of relatively low pH, Second , the sulphate ion is strongly adsorbed by the trivalent chromium

Evaluation of the Sequential Spot Sampler (S3) for time-resolved measurement of PM2.5 sulfate and nitrate through lab and field measurements

NASA Astrophysics Data System (ADS)

Hecobian, A.; Evanoski-Cole, A.; Eiguren-Fernandez, A.; Sullivan, A. P.; Lewis, G. S.; Hering, S. V.; Collett, J. L., Jr.

2016-02-01

The Sequential Spot Sampler (S3), a newly developed instrument to collect aerosols for time-resolved chemical composition measurements, was evaluated in the laboratory and field for the measurement of particulate sulfate and nitrate. The S3 uses a multi-temperature condensation growth tube to grow individual aerosols to droplets which are then deposited as a ˜ 1 mm diameter dry spot at the end of the growth tube in a 100 µL well of a multi-well plate. The well plate advances automatically to provide a sequence of time-resolved samples. The collected aerosols are subsequently analyzed in the laboratory. The sample is concentrated during the collection process, and the laboratory extraction and analysis steps can be automated. The well plate, as received from the field, is placed onto a needle-based autosampler that adds liquid for sample extraction and injects sample extract from each well onto an ion chromatograph for analysis. Laboratory evaluation for sulfate and nitrate ions showed that poly ether ether ketone (PEEK) used as well plate material does not contribute any artifacts; a 60 min extraction procedure leads to the recovery of sulfate and nitrate from the dry spots at above 95 % extraction efficiency; and samples stored frozen and analyzed up to 23 months later show less than a 10 % change in sulfate and nitrate concentrations. The limit of detection was 0.5 µg m-3 for sulfate and 0.2 µg m-3 for nitrate for a 1 h sampling period. In a month-long field study conducted in southern California, two S3s were deployed alongside a URG denuder-filter-pack and a Particle-Into-Liquid Sampler combined with an Ion Chromatograph (PILS-IC). Collocated S3 sampler concentrations compared by linear regression show good agreement, with r2 = 0.99 and slope = 0.99 (±0.004) µg m-3 for sulfate and r2 = 0.99 and slope = 1.0 (±0.006) µg m-3 for nitrate. When compared to the URG denuder-filter-pack and the PILS-IC, the S3 sulfate and nitrate concentrations yielded correlations above 0.84 for the square of the correlation coefficient and regression slopes close to 1.

Achieving high spatial resolution using a microchannel plate detector with an economic and scalable approach

NASA Astrophysics Data System (ADS)

Wiggins, B. B.; deSouza, Z. O.; Vadas, J.; Alexander, A.; Hudan, S.; deSouza, R. T.

2017-11-01

A second generation position-sensitive microchannel plate detector using the induced signal approach has been realized. This detector is presently capable of measuring the incident position of electrons, photons, or ions. To assess the spatial resolution, the masked detector was illuminated by electrons. The initial, measured spatial resolution of 276 μm FWHM was improved by requiring a minimum signal amplitude on the anode and by employing digital signal processing techniques. The resulting measured spatial resolution of 119 μm FWHM corresponds to an intrinsic resolution of 98 μm FWHM when the effect of the finite slit width is de-convoluted. This measurement is a substantial improvement from the last reported spatial resolution of 466 μm FWHM using the induced signal approach. To understand the factors that limit the measured resolution, the performance of the detector is simulated.

Control of secondary electrons from ion beam impact using a positive potential electrode

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

Crowley, T. P., E-mail: tpcrowley@xanthotechnologies.com; Demers, D. R.; Fimognari, P. J.

2016-11-15

Secondary electrons emitted when an ion beam impacts a detector can amplify the ion beam signal, but also introduce errors if electrons from one detector propagate to another. A potassium ion beam and a detector comprised of ten impact wires, four split-plates, and a pair of biased electrodes were used to demonstrate that a low-voltage, positive electrode can be used to maintain the beneficial amplification effect while greatly reducing the error introduced from the electrons traveling between detector elements.

A cometary ion mass spectrometer

NASA Technical Reports Server (NTRS)

Shelley, E. G.; Simpson, D. A.

1984-01-01

The development of flight suitable analyzer units for that part of the GIOTTO Ion Mass Spectrometer (IMS) experiment designated the High Energy Range Spectrometer (HERS) is discussed. Topics covered include: design of the total ion-optical system for the HERS analyzer; the preparation of the design of analyzing magnet; the evaluation of microchannel plate detectors and associated two-dimensional anode arrays; and the fabrication and evaluation of two flight-suitable units of the complete ion-optical analyzer system including two-dimensional imaging detectors and associated image encoding electronics.

PULSED ION SOURCE

DOEpatents

Anderson, C.E.; Ehlers, K.W.

1958-06-17

An ion source is described for producing very short high density pulses of ions without bcam scattering. The ions are created by an oscillating electron discharge within a magnetic field. After the ions are drawn from the ionization chamber by an accelerating electrode the ion beam is under the influence of the magnetic field for separation of the ions according to mass and, at the same time, passes between two neutralizing plntes maintained nt equal negative potentials. As the plates are formed of a material having a high ratio of secondary electrons to impinging ions, the ion bombardment of the plntes emits electrons which neutralize the frirge space-charge of the beam and tend to prevent widening of the beam cross section due to the mutual repulsion of the ions.

Coating for prevention of titanium combustion

NASA Technical Reports Server (NTRS)

Anderson, V. G.; Funkhouser, M.; Mcdaniel, P.

1980-01-01

A limited number of coating options for titanium gas turbine engine components were explored with the objective of minimizing potential combustion initiation and propagation without adversely affecting component mechanical properties. Objectives were met by two of the coatings, ion-plated platinum plus electroplated copper plus electroplated nickel and ion vapor deposited aluminum.

Cathodes for secondary electrochemical power-producing cells. [layers of porous substrates impregnated with S alternate with layers containing electrolyte

DOEpatents

Cairns, E.J.; Kyle, M.; Shimotake, H.

1973-02-13

A secondary electrochemical power-producing cell includes an anode containing lithium, an electrolyte containing lithium ions, and a cathode containing sulfur. The cathode comprises plates of a porous substrate material impregnated with sulfur alternating with layers (which may also comprise porous substrate plates) containing electrolyte.

WET EFFLUENT PARALLEL PLATE DIFFUSION DENUDER COUPLED CAPILLARY ION CHROMATOGRAPH FOR THE DETERMINATION OF ATMOSPHERIC TRACE GASES. (R825344)

EPA Science Inventory

We describe an inexpensive, compact parallel plate diffusion denuder coupled capillary IC system for the determination of soluble ionogenic atmospheric trace gases. The active sampling area (0.6×10 cm) of the denuder is formed in a novel manner by thermally bonding silica ge...

Spent caustic oxidation using electro-generated Fenton's reagent in a batch reactor.

PubMed

Rodriguez, Nicolas; Hansen, Henrik K; Nunez, Patricio; Guzman, Jaime

2008-07-01

This work shows the results of four Electro-Fenton laboratory tests to reduce the chemical oxygen demand (COD) in spent caustic solutions. The treatment consisted of (i) a pH reduction followed by (ii) an Electro-Fenton process, which was analyzed in this work. The Fenton's reagent was produced in a specially designed reactor, where the waste stream flowed through a labyrinth made by ferrous plates. These plates acted as sacrificial anodes-releasing Fe(2 +) cations to the solution, where H(2)O(2) was also added. The Electro-Fenton process was analyzed varying the ferrous ion concentration ([Fe(+ 2)]), the spent caustic's initial temperature and the initial pH. Close to 95% removal of COD (from 8800 mg L(- 1)) was achieved at a pH of 4, a temperature of 40 degrees C and 100 mg L(- 1) of Fe(+ 2) (applying 1 A). Two models were considered to simulate the behavior of the reactor considering (i) axial dispersion and (ii) kinetic rate, respectively. The model that was based on kinetics, proved to be the slightly closest fit to the experimental values.

Smart textile device using ion polymer metal compound.

PubMed

Nakamura, Taro; Ihara, Tadashi

2013-01-01

We have developed a smart textile device that detects angular displacement of attached surface using ion polymer metal compound. The device was composed of ion polymer metal compound (IPMC) which was fabricated from Nafion resin by heat-press and chemical gold plating. The generated voltage from IPMC was measured as a function of bending angle. Fabricated IPMC device was weaved into a cotton cloth and multidirectional movements were detected.

Li plating as unwanted side reaction in commercial Li-ion cells - A review

NASA Astrophysics Data System (ADS)

Waldmann, Thomas; Hogg, Björn-Ingo; Wohlfahrt-Mehrens, Margret

2018-04-01

Deposition of Lithium metal on anodes contributes significantly to ageing of Li-ion cells. Lithium deposition is connected not only to a drastic limitation of life-time, but also to fast-charging capability and safety issues. Lithium deposition in commercial Li-ion cells is not limited to operation conditions at low temperatures. In recent publications various types of commercial cells were investigated using complimentary analysis methods. Five cell types studied in literature (18650, 26650, pouch) serve as a basis for comparison when and why Li deposition happens in commercial Li-ion cells. In the present paper, we reviewed literature on (i) causes, (ii) hints and evidences for Li deposition, (iii) macroscopic morphology of Li deposition/plating, (iv) ageing mechanisms and shapes of capacity fade curves involving Li deposition, and (v) influences of Li deposition on safety. Although often discussed, safety issues regarding Li deposition are not only limited to dendrite growth and internal short circuits, but also to exothermic reactions in the presence of Lithium metal. Furthermore, we tried to connect knowledge from different length scales including the macroscopic level (Li-ion cells, operating conditions, gradients in cells, electrochemical tests, safety tests), the microscopic level (electrodes, particles, microstructure), and the atomic level (atoms, ions, molecules, energy barriers).

Modacrylic anion-exchange fibers for Cr(VI) removal from chromium-plating rinse water in batch and flow-through column experiments.

PubMed

Lee, Seung-Chan; Kang, Jin-Kyu; Sim, Eun-Hye; Choi, Nag-Choul; Kim, Song-Bae

2017-11-10

The aim of this study was to investigate Cr(VI) removal from chromium-plating rinse water using modacrylic anion-exchange fibers (KaracaronTM KC31). Batch experiments were performed with synthetic Cr(VI) solutions to characterize the KC31 fibers in Cr(VI) removal. Cr(VI) removal by the fibers was affected by solution pH; the Cr(VI) removal capacity was the highest at pH 2 and decreased gradually with a pH increase from 2 to 12. In regeneration and reuse experiments, the Cr(VI) removal capacity remained above 37.0 mg g -1 over five adsorption-desorption cycles, demonstrating that the fibers could be successfully regenerated with NaCl solution and reused. The maximum Cr(VI) removal capacity was determined to be 250.3 mg g -1 from the Langmuir model. In Fourier-transform infrared spectra, a Cr = O peak newly appeared at 897 cm -1 after Cr(VI) removal, whereas a Cr-O peak was detected at 772 cm -1 due to the association of Cr(VI) ions with ion-exchange sites. X-ray photoelectron spectroscopy analyses demonstrated that Cr(VI) was partially reduced to Cr(III) after the ion exchange on the surfaces of the fibers. Batch experiments with chromium-plating rinse water (Cr(VI) concentration = 1178.8 mg L -1 ) showed that the fibers had a Cr(VI) removal capacity of 28.1-186.4 mg g -1 under the given conditions (fiber dose = 1-10 g L -1 ). Column experiments (column length = 10 cm, inner diameter = 2.5 cm) were conducted to examine Cr(VI) removal from chromium-plating rinse water by the fibers under flow-through column conditions. The Cr(VI) removal capacities for the fibers at flow rates of 0.5 and 1.0 mL min -1 were 214.8 and 171.5 mg g -1 , respectively. This study demonstrates that KC31 fibers are effective in the removal of Cr(VI) ions from chromium-plating rinse water.

Ion-plasma gun for ion-milling machine

DOEpatents

Kaminsky, Manfred S.; Campana, Jr., Thomas J.

1976-01-01

An ion gun includes an elongated electrode with a hollow end portion closed by a perforated end plate. The end plate is positioned parallel to a perforated flat electrode of opposite electrical polarity. An insulated sleeve encompasses the elongated electrode and extends outwardly from the perforated end towards the flat electrode. The sleeve length is separated into two portions of different materials. The first is formed of a high-temperature material that extends over the hollow portion of the elongated electrode where the arc is initiated by a point source electrode. The second sleeve portion extending over the remainder of the elongated electrode is of a resilient material for enhanced seal-forming ability and retention of plasma gas. Perforations are arranged in the flat electrode in a mutually opposing triangular pattern to project a plasma beam having a generally flat current profile towards a target requiring precision milling.

An evaluation of a hybrid ion exchange electrodialysis process in the recovery of heavy metals from simulated dilute industrial wastewater.

PubMed

Mahmoud, Akrama; Hoadley, Andrew F A

2012-06-15

Hybrid ion exchange electrodialysis, also called electrodeionization (IXED), is a technology in which a conventional ion exchange (IX) is combined with electrodialysis (ED) to intensify mass transfer and to increase the limiting current density and therefore to carry out the treatment process more effectively. It allows the purification of metal-containing waters, as well as the production of concentrated metal salt solutions, which could be recycled. The objective of this paper was to investigate the ability of the IXED technique for the treatment of acidified copper sulphate solutions simulating rinsing water of copper plating lines. A single-stage IXED process at lab-scale with a small bed of ion exchanger resin with a uniform composition was evaluated, and the treatment performance of the process was thoroughly investigated. The IXED stack was assembled as a bed layered with the ion exchanger resin (strong acid cation-exchange Dowex™) and inert materials. The stack configuration was designed to prevent a non-uniform distribution of the current in the bed and to allow faster establishment of steady-state in the cell for IXED operation. The influence of operating conditions (e.g. ion exchanger resin with a cross-linking degree from 2 to 8% DVB, and current density) on IXED performance was examined. A response surface methodology (RSM) was used to evaluate the effects of the processing parameters of IXED on (i) the abatement yield of the metal cation, which is a fundamental purification parameter and an excellent indicator of the extent of IXED, (ii) the current yield or the efficiency of copper transport induced by the electrical field and (iii) the energy consumption. The experimental results showed that the performance at steady-state of the IXED operation with a layered bed remained modest, because of the small dimension of the bed and notably the current efficiency varied from 25 to 47% depending on the conditions applied. The feasibility of using the IXED in operations for removal of heavy metals from moderately dilute rinsing waters was successfully demonstrated. Copyright © 2012 Elsevier Ltd. All rights reserved.

Anode Design Based on Microscale Porous Scaffolds for Advanced Lithium Ion Batteries

NASA Astrophysics Data System (ADS)

Park, Hyeji; Choi, Hyelim; Nam, Kyungju; Lee, Sukyung; Um, Ji Hyun; Kim, Kyungbae; Kim, Jae-Hun; Yoon, Won-Sub; Choe, Heeman

2017-06-01

Considering the increasing demands for advanced power sources, present-day lithium-ion batteries (LIBs) must provide a higher energy and power density and better cycling stability than conventional LIBs. This study suggests a promising electrode design solution to this problem using Cu, Co, and Ti scaffolds with a microscale porous structure synthesized via freeze-casting. Co3O4 and TiO2 layers are uniformly formed on the Co and Ti scaffolds, respectively, through a simple thermal heat-treatment process, and a SnO2 layer is formed on the Cu scaffold through electroless plating and thermal oxidation. This paper characterizes and evaluates the physical and electrochemical properties of the proposed electrodes using scanning electron microscopy, four-point probe and coin-cell tests to confirm the feasibility of their potential use in LIBs.

Feasibility study of custom manufacturing methods of ionic polymer-metal composite sensors

NASA Astrophysics Data System (ADS)

Nelson, Shelby E.

The ability to create an ion exchange membrane with any shape or thickness through custom manufacturing techniques is highly desirable in ionic polymer-metal composite (IPMC) research. This is caused by the poor selection and limited availability of certain thicknesses of commercial ion exchange membranes. The objective of this study is to determine the feasibility of manufacturing custom ion exchange membranes for IPMC sensors. The manufacturing methods used in this study are extrusion, injection molding, and hot pressing. A commercial membrane from Golden Energy Fuel Cells (GEFC) is used as a comparison. After the membranes are fabricated, certain properties of the membranes are tested throughout each processing stage to determine if they are suitable to be developed into IPMCs. The three processing stages are pre-activation, activation (hydrated and dehydrated), and IPMC. It was observed that the stiffness of the membranes increased from pre-activation to activation and decreased from activation to IPMC. A more flexible membrane in an IPMC allows for larger cation displacement within the membrane. The extruded and injection molded membranes showed the most potential with having the lowest stiffness of all the samples; however, they were not able to be made into IPMCs due to repeated membrane failures in the primary plating process. Gas accumulated between the layers that formed in the membranes due to the extrusion and injection molding cooling process during manufacturing. The hot pressed membrane was the only custom manufactured membrane to be fully processed into an IPMC. The hot pressed and GEFC IPMC sensors were operated at 1 Hz, 5 Hz, and 10 Hz frequencies with the GEFC IPMC producing the strongest output voltage signal. While the extruded and injection molded membranes showed potential to become IPMCs with their high water uptake percentage, high ion exchange capacity, and low stiffness, more development is needed within the manufacturing process to make a uniform sample that does not fail during chemical processing.

Investigation on micro-patterned gold-plated polymer substrate for a micro hydraulic actuator

NASA Astrophysics Data System (ADS)

Sundaresan, Vishnu Baba; Akle, Barbar; Leo, Donald J.

2006-03-01

Plants have the ability to develop large mechanical force from chemical energy available with bio-fuels. The energy released by the cleavage of a terminal phosphate ion during the hydrolysis of a bio-fuel assists the transport of ions and fluids in cellular homeostasis. Materials that develop pressure and hence strain similar to the response of plants to an external stimuli are classified as nastic materials. This new class of actuators use protein transporters as functional units to move species and result in deformation [Leo et al 2005 (Proceedings of IMECE - 06)]. The ion transporters are hydrocarbons which are formed across the cellular membranes. The membranes that house the ion transporters are aggregates of phospholipids rigidized by cytoskeleton. Reconstituting these nano-machines on a harder matrix is quintessential to build a functional device. Artificial phospholipid membranes or Biliayer lipid membranes (BLM) have poor structural integrity and do not adhere to most surfaces. Patterned arrays of pores made on Poly-propylene glycol-diacrylate (PPG-DA) substrate, a photo curable polymer was made available to us for initial design iterations for an actuator. Hydrophobicity of PPG-DA posed initial problems to support a BLM. We modified the surface of micropatterned PPG-DA membrane by gold plating it. The surface of the porous PPG-DA membranes was plated with gold (Au). A 10nm seeding layer of Au was sputtered on the surface of the membrane. Further gold was reduced onto the sputtered gold surface [Supriya et al(Langmuir 2004, 20, 8870-8876)] by suspending the samples in a solution of hydroxylamine and Hydrogen tetrachloroaurate(III) trihydrate [HAuCl4.3H2O]. This reduction process increased the thickness of the gold, enhanced its adhesion to the PPG-DA substrate and improved the shapes of the pores. This surface modification of PPG-DA helped us form stable BLM with 1-Palmitoyl-2-Oleoyl-sn-Glycero-3- [Phospho-L-Serine] (Sodium Salt) (POPS), 1-Palmitoyl-2-Oleoyl-sn-Glycero- 3-Phosphoethanolamine (POPE) lipids. The observed ionic resistance of the BLM remained stable and sustained 4 mm water column for the the four hours observation period. This article describes the procedure we adopted to modify the PPG-DA substrate, form a BLM and the procedure to quantify the stability of the BLM formed with -amine and -thiol head groups in the lipids.

Preparation of on-plate immobilized metal ion affinity chromatography platform via dopamine chemistry for highly selective isolation of phosphopeptides with matrix assisted laser desorption/ionization mass spectrometry analysis.

PubMed

Shi, Chenyi; Lin, Qinrui; Deng, Chunhui

2015-04-01

In this study, a novel on-plate IMAC technique was developed for highly selective enrichment and isolation of phosphopeptides with high-throughput MALDI-TOF-MS analysis. At first, a MALDI plate was coated with polydopamine (PDA), and then Ti(4+) was immobilized on the PDA-coated plate. The obtained IMAC plate was successfully applied to the highly selective enrichment and isolation of phosphopeptides in protein digests and human serum. Because of no loss of samples, the on-plate IMAC platform exhibits excellent selectivity and sensitivity in the selective enrichment and isolation of phosphopeptides, which provides a potential technique for high selectivity in the detection of low-abundance phosphopeptides in biological samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Morphology of gold and copper ion-plated coatings

NASA Technical Reports Server (NTRS)

Spalvins, T.

1978-01-01

Copper and gold films (0.2 to 2 microns thick) were ion plated onto polished 304-stainless-steel, glass, mica surfaces. These coatings were examined by SEM for defects in their morphological growth. Three types of defects were distinguished: nodular growth, abnormal or runaway growth, and spits. The cause for each type of defect was investigated. Nodular growth is due to inherent substrate microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation (ejection of droplets). All these defects induce stresses and produce porosity in the coatings and thus weaken their mechanical properties. During surface rubbing, large nodules are pulled out, leaving vacancies in the coatings.

Potentiodynamic studies of Ni-P-TiO2 nano-composited coating on the mild steel deposited by electroless plating method

NASA Astrophysics Data System (ADS)

Uttam, Vibha; Duchaniya, R. K.

2016-05-01

Now a days, corrosion studies are important for reducing the wastage of metals. The importance of corrosion studies is two folds i.e. first is economic, including the reduction of material losses resulting from the wasting away or sudden failure of materials and second is conservation Electroless process is an autocatalytic reduction method in which metallic ions are reduced in the solution. Nanocomposite coatings of Ni-P-TiO2 on mild steel are deposited by varying volume of TiO2 nano-powder by electroless method from Ni-P plating bath containing Nickel Sulphate as a source of nickel ions, sodium hypophosphite as the reducing agent, lactic acid as a complexing agents and TiO2 nano powder. Electroless Ni-P-TiO2 coating have been widely used in the chemical process industries, mechanical industries, electronic industries and chloroalkali industries due to their excellent corrosion with mechanical properties. In the present work, deposition of Ni-P alloy coating and Ni-P-TiO2 nanocomposited coatings were done on the mild steel and corrosion properties were studied with Potentio-dynamic polarization measurements method in 3.5 wt% sodium chloride solution. It showed in the experiments that Ni-P-TiO2 nanocomposited coating has better corrosion resistance as comparedthan Ni-P alloy coating. Morphological studies were done by field emission scanning electron microscopy (FESEM), energy-dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD). These studies confirmed the deposition of Ni-P alloy coating and Ni-P-TiO2 nanocomposited coating.

Method and apparatus for sputtering utilizing an apertured electrode and a pulsed substrate bias

NASA Technical Reports Server (NTRS)

Przybyszewski, J. S.; Shaltens, R. K. (Inventor)

1973-01-01

The method and equipment used for sputtering by use of an apertured electrode and a pulsed substrate bias are discussed. The technique combines the advantages of ion plating with the versatility of a radio frequency sputtered source. Electroplating is accomplished by passing a pulsed high voltage direct current to the article being plated during radio frequency sputtering.

The Improvement of Ion Plated Ag and Au Film Adherence to Si3N4 and SiC Surfaces for Increased Tribological Performance

NASA Technical Reports Server (NTRS)

Spalvins, Talivaldis

1998-01-01

A modified dc-diode plating system, utilizing a metallic screen cage as a cathode and referred as SCREEN CAGE ION PLATING (SCIP), is used to deposit Ag and Au lubricating films on Si3N4 and SiC surfaces. When deposition is performed in Ar or N2, glow discharge, the surface displays poor adhesive strength (less than 5 MPa). A dramatic increase in adhesive strength (less than 80 MPa) is achieved when plating is performed in a reactive 50% 02 + 50% Ar glow discharge. The excited/ionized oxygen species (O2(+)/O(+) in the glow discharge contribute to the oxidation of the Si3N4 or SiC surfaces as determined by X-ray Photoelectron Spectroscopy (XTS) depth profiling. The reactively sputter-oxidized S3N4 or SiC surfaces and the activated-oxidized-metastable Ag or Au species formed in the plasma cooperatively contribute to the increased adherence. As a result, the linear thermal expansion coefficient mismatch at the interface is reduced. These lubricating Ag and Au films under sliding conditions reduce the friction coefficient by a factor of 2-1/2 to 4.

Molecular Ionization-Desorption Analysis Source (MIDAS) for Mass Spectrometry: Thin-Layer Chromatography.

PubMed

Winter, Gregory T; Wilhide, Joshua A; LaCourse, William R

2016-02-01

Molecular ionization-desorption analysis source (MIDAS), which is a desorption atmospheric pressure chemical ionization (DAPCI) type source, for mass spectrometry has been developed as a multi-functional platform for the direct sampling of surfaces. In this article, its utility for the analysis of thin-layer chromatography (TLC) plates is highlighted. Amino acids, which are difficult to visualize without staining reagents or charring, were detected and identified directly from a TLC plate. To demonstrate the full potential of MIDAS, all active ingredients from an analgesic tablet, separated on a TLC plate, were successfully detected using both positive and negative ion modes. The identity of each of the compounds was confirmed from their mass spectra and compared against standards. Post separation, the chemical signal (blue permanent marker) as reference marks placed at the origin and solvent front were used to calculate retention factor (Rf) values from the resulting ion chromatogram. The quantitative capabilities of the device were exhibited by scanning caffeine spots on a TLC plate of increasing sample amount. A linear curve based on peak are, R2 = 0.994, was generated for seven spots ranging from 50 to 1000 ng of caffeine per spot.

Molecular Ionization-Desorption Analysis Source (MIDAS) for Mass Spectrometry: Thin-Layer Chromatography

NASA Astrophysics Data System (ADS)

Winter, Gregory T.; Wilhide, Joshua A.; LaCourse, William R.

2016-02-01

Molecular ionization-desorption analysis source (MIDAS), which is a desorption atmospheric pressure chemical ionization (DAPCI) type source, for mass spectrometry has been developed as a multi-functional platform for the direct sampling of surfaces. In this article, its utility for the analysis of thin-layer chromatography (TLC) plates is highlighted. Amino acids, which are difficult to visualize without staining reagents or charring, were detected and identified directly from a TLC plate. To demonstrate the full potential of MIDAS, all active ingredients from an analgesic tablet, separated on a TLC plate, were successfully detected using both positive and negative ion modes. The identity of each of the compounds was confirmed from their mass spectra and compared against standards. Post separation, the chemical signal (blue permanent marker) as reference marks placed at the origin and solvent front were used to calculate retention factor (Rf) values from the resulting ion chromatogram. The quantitative capabilities of the device were exhibited by scanning caffeine spots on a TLC plate of increasing sample amount. A linear curve based on peak are, R2 = 0.994, was generated for seven spots ranging from 50 to 1000 ng of caffeine per spot.

Plasma-assisted physical vapor deposition surface treatments for tribological control

NASA Technical Reports Server (NTRS)

Spalvins, Talivaldis

1990-01-01

In any mechanical or engineering system where contacting surfaces are in relative motion, adhesion, wear, and friction affect reliability and performance. With the advancement of space age transportation systems, the tribological requirements have dramatically increased. This is due to the optimized design, precision tolerance requirements, and high reliability expected for solid lubricating films in order to withstand hostile operating conditions (vacuum, high-low temperatures, high loads, and space radiation). For these problem areas the ion-assisted deposition/modification processes (plasma-based and ion beam techniques) offer the greatest potential for the synthesis of thin films and the tailoring of adherence and chemical and structural properties for optimized tribological performance. The present practices and new approaches of applying soft solid lubricant and hard wear resistant films to engineering substrates are reviewed. The ion bombardment treatments have increased film adherence, lowered friction coefficients, and enhanced wear life of the solid lubricating films such as the dichalcogenides (MoS2) and the soft metals (Au, Ag, Pb). Currently, sputtering is the preferred method of applying MoS2 films; and ion plating, the soft metallic films. Ultralow friction coefficients (less than 0.01) were achieved with sputtered MoS2. Further, new diamond-like carbon and BN lubricating films are being developed by using the ion assisted deposition techniques.

Calculation of ion distribution functions and neoclassical transport in the edge of single-null divertor tokamaks

NASA Astrophysics Data System (ADS)

Rognlien, T. D.; Cohen, R. H.; Xu, X. Q.

2007-11-01

The ion distribution function in the H-mode pedestal region and outward across the magnetic separatrix is expected to have a substantial non-Maxwellian character owing to the large banana orbits and steep gradients in temperature and density. The 4D (2r,2v) version of the TEMPEST continuum gyrokinetic code is used with a Coulomb collision model to calculate the ion distribution in a single-null tokamak geometry throughout the pedestal/scrape-off-layer regions. The mean density, parallel velocity, and energy radial profiles are shown at various poloidal locations. The collisions cause neoclassical energy transport through the pedestal that is then lost to the divertor plates along the open field lines outside the separatrix. The resulting heat flux profiles at the inner and outer divertor plates are presented and discussed, including asymmetries that depend on the B-field direction. Of particular focus is the effect on ion profiles and fluxes of a radial electric field exhibiting a deep well just inside the separatrix, which reduces the width of the banana orbits by the well-known squeezing effect.

Lithium Ion Battery Anode Aging Mechanisms

PubMed Central

Agubra, Victor; Fergus, Jeffrey

2013-01-01

Degradation mechanisms such as lithium plating, growth of the passivated surface film layer on the electrodes and loss of both recyclable lithium ions and electrode material adversely affect the longevity of the lithium ion battery. The anode electrode is very vulnerable to these degradation mechanisms. In this paper, the most common aging mechanisms occurring at the anode during the operation of the lithium battery, as well as some approaches for minimizing the degradation are reviewed. PMID:28809211

Gradient isolator for flow field of fuel cell assembly

DOEpatents

Ernst, W.D.

1999-06-15

Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions. 4 figs.

Multiple lesion track structure model

NASA Technical Reports Server (NTRS)

Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.

1992-01-01

A multilesion cell kinetic model is derived, and radiation kinetic coefficients are related to the Katz track structure model. The repair-related coefficients are determined from the delayed plating experiments of Yang et al. for the C3H10T1/2 cell system. The model agrees well with the x ray and heavy ion experiments of Yang et al. for the immediate plating, delaying plating, and fractionated exposure protocols employed by Yang. A study is made of the effects of target fragments in energetic proton exposures and of the repair-deficient target-fragment-induced lesions.

Gradient isolator for flow field of fuel cell assembly

DOEpatents

Ernst, William D.

1999-01-01

Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions.

SLIT ADJUSTMENT CLAMP

DOEpatents

McKenzie, K.R.

1959-07-01

An electrode support which permits accurate alignment and adjustment of the electrode in a plurality of planes and about a plurality of axes in a calutron is described. The support will align the slits in the electrode with the slits of an ionizing chamber so as to provide for the egress of ions. The support comprises an insulator, a leveling plate carried by the insulator and having diametrically opposed attaching screws screwed to the plate and the insulator and diametrically opposed adjusting screws for bearing against the insulator, and an electrode associated with the plate for adjustment therewith.

TEMPEST simulations of the neoclassical transport in a single-null tokamak geometry

NASA Astrophysics Data System (ADS)

Xu, X. Q.; Cohen, R. H.; Rognlien, T. D.

2009-05-01

TEMPEST simulations were carried out for plasma transport and flow dynamics in a single-null tokamak geometry. The core radial boundary ion distribution is a fixed Maxwellian FM with N0=N(ψ0) and Ti0=Ti(ψ0)=300eV, and exterior radial boundary ion distribution is Neumann boundary condition with Fi(,,μ)/ψ|ψw=0 during a simulation. Given boundary conditions and initial profiles, the interior plasmas in the simulations should evolve into a neoclassical steady state. A volume source term in the private flux region is included, representing the ionization in the private flux region to achieve the neoclassical steady state. A series of TEMPEST simulations are conducted to investigate the scaling characteristics of the neoclassical transport and flow as a function of ν*i via a density scan. Here ν*i is the effective collision frequency, defined by ν*i=&-3/2circ;νii√2qR0/vTi, νii is the ion-ion collision, and vTi the ion thermal velocity. Simulation results show significant poloidal variation of density and ion temperature profiles due to the endloss machanism at the divertor plates. Each region (Edge, the SOL and private flux) achieves the dynamical steady state at its own time scale due to the different physical processes. The impact of self-consistent electric field on transport and flow will be presented.

Highly charged ion based time of flight emission microscope

DOEpatents

Barnes, Alan V.; Schenkel, Thomas; Hamza, Alex V.; Schneider, Dieter H.; Doyle, Barney

2001-01-01

A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

Calculation of Thermally-Induced Displacements in Spherically Domed Ion Engine Grids

NASA Technical Reports Server (NTRS)

Soulas, George C.

2006-01-01

An analytical method for predicting the thermally-induced normal and tangential displacements of spherically domed ion optics grids under an axisymmetric thermal loading is presented. A fixed edge support that could be thermally expanded is used for this analysis. Equations for the displacements both normal and tangential to the surface of the spherical shell are derived. A simplified equation for the displacement at the center of the spherical dome is also derived. The effects of plate perforation on displacements and stresses are determined by modeling the perforated plate as an equivalent solid plate with modified, or effective, material properties. Analytical model results are compared to the results from a finite element model. For the solid shell, comparisons showed that the analytical model produces results that closely match the finite element model results. The simplified equation for the normal displacement of the spherical dome center is also found to accurately predict this displacement. For the perforated shells, the analytical solution and simplified equation produce accurate results for materials with low thermal expansion coefficients.

Novel 3D micromirror for miniature optical bio-robe SiOB assembly

NASA Astrophysics Data System (ADS)

Singh, Janak; Xu, Yingshun; Premachandran, C. S.; Jason, Teo Hui Siang; Chen, Nanguang

2008-02-01

This article presents design and development of a novel 3D micromirror for large deflection scanning application in invivo optical coherence tomography (OCT) bio-imaging probe. Overall mirror chip size is critical to reduce the diameter of the probe; however, mirror plate itself should not be less than 500 μm as smaller size means reducing the amount of light collected after scattering for OCT imaging. In this study, mirror chip sizes of 1 × 1 mm2 and 1.5 × 1.5 mm2 were developed with respectively 400 and 500 micrometer diameter mirror plates. The design includes electro thermal excitation mechanism in the same plane as mirror plate to achieve 3D free space scanning. Larger deflection requires longer actuators, which usually increase the overall size of the chip. To accommodate longer actuators and keep overall chip size same curved beam actuators are designed and integrated for micromirror scanning. Typical length of the actuators was 800 micrometer, which provided up to 17 degrees deflection. Deep reactive ion etching (DRIE) process module was used extensively to etch high aspect ratio structures and keep the total mirror chip size small.

A modified Poisson-Boltzmann equation applied to protein adsorption.

PubMed

Gama, Marlon de Souza; Santos, Mirella Simões; Lima, Eduardo Rocha de Almeida; Tavares, Frederico Wanderley; Barreto, Amaro Gomes Barreto

2018-01-05

Ion-exchange chromatography has been widely used as a standard process in purification and analysis of protein, based on the electrostatic interaction between the protein and the stationary phase. Through the years, several approaches are used to improve the thermodynamic description of colloidal particle-surface interaction systems, however there are still a lot of gaps specifically when describing the behavior of protein adsorption. Here, we present an improved methodology for predicting the adsorption equilibrium constant by solving the modified Poisson-Boltzmann (PB) equation in bispherical coordinates. By including dispersion interactions between ions and protein, and between ions and surface, the modified PB equation used can describe the Hofmeister effects. We solve the modified Poisson-Boltzmann equation to calculate the protein-surface potential of mean force, treated as spherical colloid-plate system, as a function of process variables. From the potential of mean force, the Henry constants of adsorption, for different proteins and surfaces, are calculated as a function of pH, salt concentration, salt type, and temperature. The obtained Henry constants are compared with experimental data for several isotherms showing excellent agreement. We have also performed a sensitivity analysis to verify the behavior of different kind of salts and the Hofmeister effects. Copyright © 2017 Elsevier B.V. All rights reserved.

A comparative study on the analytical utility of atmospheric and low-pressure MALDI sources for the mass spectrometric characterization of peptides.

PubMed

Moskovets, Eugene; Misharin, Alexander; Laiko, Viktor; Doroshenko, Vladimir

2016-07-15

A comparative MS study was conducted on the analytical performance of two matrix-assisted laser desorption/ionization (MALDI) sources that operated at either low pressure (∼1Torr) or at atmospheric pressure. In both cases, the MALDI sources were attached to a linear ion trap mass spectrometer equipped with a two-stage ion funnel. The obtained results indicate that the limits of detection, in the analysis of identical peptide samples, were much lower with the source that was operated slightly below the 1-Torr pressure. In the low-pressure (LP) MALDI source, ion signals were observed at a laser fluence that was considerably lower than the one determining the appearance of ion signals in the atmospheric pressure (AP) MALDI source. When the near-threshold laser fluences were used to record MALDI MS spectra at 1-Torr and 750-Torr pressures, the level of chemical noise at the 1-Torr pressure was much lower compared to that at AP. The dependency of the analyte ion signals on the accelerating field which dragged the ions from the MALDI plate to the MS analyzer are presented for the LP and AP MALDI sources. The study indicates that the laser fluence, background gas pressure, and field accelerating the ions away from a MALDI plate were the main parameters which determined the ion yield, signal-to-noise (S/N) ratios, the fragmentation of the analyte ions, and adduct formation in the LP and AP MALDI MS methods. The presented results can be helpful for a deeper insight into the mechanisms responsible for the ion formation in MALDI. Copyright © 2016 Elsevier Inc. All rights reserved.

A comparison of cation sampling in forest soils by tension and tension-free lysimeters

Treesearch

James H. Miller

1981-01-01

Field tests conducted in two soils with ceramic cup, ceramic plate, and tension-free lysimeters showed no concentration differences in collected cations (Ca, Mg, K, Na) between cups and plates, except for the hydrogen ion. Mean pH was 0.6 lower in cup collected samples for a sandy loam profile. Tension-free lysimeters of the design tested had persistent contamination...

ION SOURCE FOR CALUTRONS

DOEpatents

Tolmie, J.R.

1958-09-16

An improvement is presented in ion sources of the type employed in calutron devices. The described ion source has for its inventive contribution the incorporation of a plate-like cathode having the general configuration of a polygon including a given number of apices. When a polyphase source of current has a phase connected to each of the apices, the cathode is heated and rendered electron emissive. This particular cathode configuration is of sturdy construction and provides unuform emission over a considerable area.

Adherence and Bonding of the Ion Plated Films.

DTIC Science & Technology

1983-07-01

adhesion strength is, therefore, governed by the physical interactions and van der waals forces yield the lower bound estimates(42). c) Compound interfaces...plasma and 30% for gold- argon plasma, when using high current densities of the or- der of several milliamperes per square centimetere. Buckely et.al...resulted only from ions following the field lines, whereas that on the front surface was the re- sult of both ions and neut ils. In the present work we

Ripple formation on Si surfaces during plasma etching in Cl2

NASA Astrophysics Data System (ADS)

Nakazaki, Nobuya; Matsumoto, Haruka; Sonobe, Soma; Hatsuse, Takumi; Tsuda, Hirotaka; Takao, Yoshinori; Eriguchi, Koji; Ono, Kouichi

2018-05-01

Nanoscale surface roughening and ripple formation in response to ion incidence angle has been investigated during inductively coupled plasma etching of Si in Cl2, using sheath control plates to achieve the off-normal ion incidence on blank substrate surfaces. The sheath control plate consisted of an array of inclined trenches, being set into place on the rf-biased electrode, where their widths and depths were chosen in such a way that the sheath edge was pushed out of the trenches. The distortion of potential distributions and the consequent deflection of ion trajectories above and in the trenches were then analyzed based on electrostatic particle-in-cell simulations of the plasma sheath, to evaluate the angular distributions of ion fluxes incident on substrates pasted on sidewalls and/or at the bottom of the trenches. Experiments showed well-defined periodic sawtooth-like ripples with their wave vector oriented parallel to the direction of ion incidence at intermediate off-normal angles, while relatively weak corrugations or ripplelike structures with the wave vector perpendicular to it at high off-normal angles. Possible mechanisms for the formation of surface ripples during plasma etching are discussed with the help of Monte Carlo simulations of plasma-surface interactions and feature profile evolution. The results indicate the possibility of providing an alternative to ion beam sputtering for self-organized formation of ordered surface nanostructures.

Diagnosing and Correcting Mass Accuracy and Signal Intensity Error Due to Initial Ion Position Variations in a MALDI TOFMS

NASA Astrophysics Data System (ADS)

Malys, Brian J.; Piotrowski, Michelle L.; Owens, Kevin G.

2018-02-01

Frustrated by worse than expected error for both peak area and time-of-flight (TOF) in matrix assisted laser desorption ionization (MALDI) experiments using samples prepared by electrospray deposition, it was finally determined that there was a correlation between sample location on the target plate and the measured TOF/peak area. Variations in both TOF and peak area were found to be due to small differences in the initial position of ions formed in the source region of the TOF mass spectrometer. These differences arise largely from misalignment of the instrument sample stage, with a smaller contribution arising from the non-ideal shape of the target plates used. By physically measuring the target plates used and comparing TOF data collected from three different instruments, an estimate of the magnitude and direction of the sample stage misalignment was determined for each of the instruments. A correction method was developed to correct the TOFs and peak areas obtained for a given combination of target plate and instrument. Two correction factors are determined, one by initially collecting spectra from each sample position used and another by using spectra from a single position for each set of samples on a target plate. For TOF and mass values, use of the correction factor reduced the error by a factor of 4, with the relative standard deviation (RSD) of the corrected masses being reduced to 12-24 ppm. For the peak areas, the RSD was reduced from 28% to 16% for samples deposited twice onto two target plates over two days.

Diagnosing and Correcting Mass Accuracy and Signal Intensity Error Due to Initial Ion Position Variations in a MALDI TOFMS

NASA Astrophysics Data System (ADS)

Malys, Brian J.; Piotrowski, Michelle L.; Owens, Kevin G.

2017-12-01

Frustrated by worse than expected error for both peak area and time-of-flight (TOF) in matrix assisted laser desorption ionization (MALDI) experiments using samples prepared by electrospray deposition, it was finally determined that there was a correlation between sample location on the target plate and the measured TOF/peak area. Variations in both TOF and peak area were found to be due to small differences in the initial position of ions formed in the source region of the TOF mass spectrometer. These differences arise largely from misalignment of the instrument sample stage, with a smaller contribution arising from the non-ideal shape of the target plates used. By physically measuring the target plates used and comparing TOF data collected from three different instruments, an estimate of the magnitude and direction of the sample stage misalignment was determined for each of the instruments. A correction method was developed to correct the TOFs and peak areas obtained for a given combination of target plate and instrument. Two correction factors are determined, one by initially collecting spectra from each sample position used and another by using spectra from a single position for each set of samples on a target plate. For TOF and mass values, use of the correction factor reduced the error by a factor of 4, with the relative standard deviation (RSD) of the corrected masses being reduced to 12-24 ppm. For the peak areas, the RSD was reduced from 28% to 16% for samples deposited twice onto two target plates over two days. [Figure not available: see fulltext.

Time-of-flight measurements of heavy ions using Si PIN diodes

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

Strekalovsky, A. O., E-mail: alex.strek@bk.ru; Kamanin, D. V.; Pyatkov, Yu. V.

2016-12-15

A new off-line timing method for PIN diode signals is presented which allows the plasma delay effect to be suppressed. Velocities of heavy ions measured by the new method are in good agreement within a wide range of masses and energies with velocities measured by time stamp detectors based on microchannel plates.

Plating Processes Utilizing High Intensity Acoustic Beams

NASA Technical Reports Server (NTRS)

Oeftering, Richard C. (Inventor); Denofrio, Charles (Inventor)

2002-01-01

A system and a method for selective plating processes are disclosed which use directed beams of high intensity acoustic waves to create non-linear effects that alter and improve the plating process. The directed beams are focused on the surface of an object, which in one embodiment is immersed in a plating solution, and in another embodiment is suspended above a plating solution. The plating processes provide precise control of the thickness of the layers of the plating, while at the same time, in at least some incidents, eliminates the need for masking.

PVD-Beschichtungstechnologie

NASA Astrophysics Data System (ADS)

Lake, Markus K.

Die PVD-Technologie umfasst eine Reihe von Beschichtungsverfahren zur Abscheidung von Metallen, Legierungen oder chemischen Verbindungen durch Zufuhr von thermischer Energie oder durch Teilchenbeschuss im Hochvakuum. PVDVerfahren gestatten u. a. die Beschichtung bei niedrigen Prozesstemperaturen, so dass thermisch sensible Substrate, z. B. wärmebehandelte Stähle oder ausgewählte Kunststoffe, beschichtet werden können. Insbesondere mit dem Magnetron Sputter Ion Plating-Verfahren (MSIP-Verfahren) und mit dem Arc Ion Plating-Verfahren (AIP-Verfahren) ist es möglich, thermisch vorbehandelte Werkstoffe zu beschichten, ohne den eingestellten Wärmebehandlungszustand (Härte, Spannungszustand) zu verändern. Ferner können endbearbeitete Bauteile mit der PVD-Technologie beschichtet werden, da die eingesetzten PVD-Verfahren die Ausgangsoberfläche konturgetreu abbilden, ohne dass eine Nachbearbeitung erforderlich wird.

Rechargeable lithium-ion cell

DOEpatents

Bechtold, Dieter; Bartke, Dietrich; Kramer, Peter; Kretzschmar, Reiner; Vollbert, Jurgen

1999-01-01

The invention relates to a rechargeable lithium-ion cell, a method for its manufacture, and its application. The cell is distinguished by the fact that it has a metallic housing (21) which is electrically insulated internally by two half shells (15), which cover electrode plates (8) and main output tabs (7) and are composed of a non-conductive material, where the metallic housing is electrically insulated externally by means of an insulation coating. The cell also has a bursting membrane (4) which, in its normal position, is located above the electrolyte level of the cell (1). In addition, the cell has a twisting protection (6) which extends over the entire surface of the cover (2) and provides centering and assembly functions for the electrode package, which comprises the electrode plates (8).

Electrospinning for nano- to mesoscale photonic structures

NASA Astrophysics Data System (ADS)

Skinner, Jack L.; Andriolo, Jessica M.; Murphy, John P.; Ross, Brandon M.

2017-08-01

The fabrication of photonic and electronic structures and devices has directed the manufacturing industry for the last 50 years. Currently, the majority of small-scale photonic devices are created by traditional microfabrication techniques that create features by processes such as lithography and electron or ion beam direct writing. Microfabrication techniques are often expensive and slow. In contrast, the use of electrospinning (ES) in the fabrication of micro- and nano-scale devices for the manipulation of photons and electrons provides a relatively simple and economic viable alternative. ES involves the delivery of a polymer solution to a capillary held at a high voltage relative to the fiber deposition surface. Electrostatic force developed between the collection plate and the polymer promotes fiber deposition onto the collection plate. Issues with ES fabrication exist primarily due to an instability region that exists between the capillary and collection plate and is characterized by chaotic motion of the depositing polymer fiber. Material limitations to ES also exist; not all polymers of interest are amenable to the ES process due to process dependencies on molecular weight and chain entanglement or incompatibility with other polymers and overall process compatibility. Passive and active electronic and photonic fibers fabricated through the ES have great potential for use in light generation and collection in optical and electronic structures/devices. ES produces fiber devices that can be combined with inorganic, metallic, biological, or organic materials for novel device design. Synergistic material selection and post-processing techniques are also utilized for broad-ranging applications of organic nanofibers that span from biological to electronic, photovoltaic, or photonic. As the ability to electrospin optically and/or electronically active materials in a controlled manner continues to improve, the complexity and diversity of devices fabricated from this process can be expected to grow rapidly and provide an alternative to traditional resource-intensive fabrication techniques.

A review comparing cathodic arcs and high power impulse magnetron sputtering (HiPIMS)

DOE PAGES

Anders, André

2014-09-02

In this study, high power impulse magnetron sputtering (HiPIMS) has been in the center of attention over the last years as it is an emerging physical vapor deposition (PVD) technology that combines advantages of magnetron sputtering with various forms of energetic deposition of films such as ion plating and cathodic arc plasma deposition. It should not come at a surprise that many extension and variations of HiPIMS make use, intentionally or unintentionally, of previously discovered approaches to film processing such as substrate surface preparation by metal ion sputtering and phased biasing for film texture and stress control. Therefore, in thismore » review, an overview is given on some historical developments and features of cathodic arc and HiPIMS plasmas, showing commonalities and differences. To limit the scope, emphasis is put on plasma properties, as opposed to surveying the vast literature on specific film materials and their properties.« less

Strategic assay deployment as a method for countering analytical bottlenecks in high throughput process development: case studies in ion exchange chromatography.

PubMed

Konstantinidis, Spyridon; Heldin, Eva; Chhatre, Sunil; Velayudhan, Ajoy; Titchener-Hooker, Nigel

2012-01-01

High throughput approaches to facilitate the development of chromatographic separations have now been adopted widely in the biopharmaceutical industry, but issues of how to reduce the associated analytical burden remain. For example, acquiring experimental data by high level factorial designs in 96 well plates can place a considerable strain upon assay capabilities, generating a bottleneck that limits significantly the speed of process characterization. This article proposes an approach designed to counter this challenge; Strategic Assay Deployment (SAD). In SAD, a set of available analytical methods is investigated to determine which set of techniques is the most appropriate to use and how best to deploy these to reduce the consumption of analytical resources while still enabling accurate and complete process characterization. The approach is demonstrated by investigating how salt concentration and pH affect the binding of green fluorescent protein from Escherichia coli homogenate to an anion exchange resin presented in a 96-well filter plate format. Compared with the deployment of routinely used analytical methods alone, the application of SAD reduced both the total assay time and total assay material consumption by at least 40% and 5%, respectively. SAD has significant utility in accelerating bioprocess development activities. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

Biological synthesis of triangular gold nanoprisms

NASA Astrophysics Data System (ADS)

Shankar, S. Shiv; Rai, Akhilesh; Ankamwar, Balaprasad; Singh, Amit; Ahmad, Absar; Sastry, Murali

2004-07-01

The optoelectronic and physicochemical properties of nanoscale matter are a strong function of particle size. Nanoparticle shape also contributes significantly to modulating their electronic properties. Several shapes ranging from rods to wires to plates to teardrop structures may be obtained by chemical methods; triangular nanoparticles have been synthesized by using a seeded growth process. Here, we report the discovery that the extract from the lemongrass plant, when reacted with aqueous chloroaurate ions, yields a high percentage of thin, flat, single-crystalline gold nanotriangles. The nanotriangles seem to grow by a process involving rapid reduction, assembly and room-temperature sintering of 'liquid-like' spherical gold nanoparticles. The anisotropy in nanoparticle shape results in large near-infrared absorption by the particles, and highly anisotropic electron transport in films of the nanotriangles.

Arc plasma generator of atomic driver for steady-state negative ion source.

PubMed

Ivanov, A A; Belchenko, Yu I; Davydenko, V I; Ivanov, I A; Kolmogorov, V V; Listopad, A A; Mishagin, V V; Putvinsky, S V; Shulzhenko, G I; Smirnov, A

2014-02-01

The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB6 cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.

High-performance etching of multilevel phase-type Fresnel zone plates with large apertures

NASA Astrophysics Data System (ADS)

Guo, Chengli; Zhang, Zhiyu; Xue, Donglin; Li, Longxiang; Wang, Ruoqiu; Zhou, Xiaoguang; Zhang, Feng; Zhang, Xuejun

2018-01-01

To ensure the etching depth uniformity of large-aperture Fresnel zone plates (FZPs) with controllable depths, a combination of a point source ion beam with a dwell-time algorithm has been proposed. According to the obtained distribution of the removal function, the latter can be used to optimize the etching time matrix by minimizing the root-mean-square error between the simulation results and the design value. Owing to the convolution operation in the utilized algorithm, the etching depth error is insensitive to the etching rate fluctuations of the ion beam, thereby reducing the requirement for the etching stability of the ion system. As a result, a 4-level FZP with a circular aperture of 300 mm was fabricated. The obtained results showed that the etching depth uniformity of the full aperture could be reduced to below 1%, which was sufficiently accurate for meeting the use requirements of FZPs. The proposed etching method may serve as an alternative way of etching high-precision diffractive optical elements with large apertures.

Ion and electron sheath characteristics in a low density and low temperature plasma

NASA Astrophysics Data System (ADS)

Borgohain, Binita; Bailung, H.

2017-11-01

Ion and electron sheath characteristics in a low electron temperature (Te ˜ 0.25-0.40 eV) and density (ne ˜ 106-107 cm-3) plasma are described. The plasma is produced in the experimental volume through diffusion from a hot cathode discharge plasma source by using a magnetic filter. The electron energy distribution function in the experimental plasma volume is measured to be a narrow Maxwellian distribution indicating the absence of primary and energetic electrons which are decoupled in the source side by the cusp magnetic field near the filter. An emissive probe is used to measure the sheath potential profiles in front of a metal plate biased negative and positive with respect to the plasma potential. For a positive plate bias, the electron density decreases considerably and the electron sheath expands with a longer presheath region compared to the ion sheath. The sheath potential structures are found to follow the Debye sheath model.

Optically stimulated luminescence in an imaging plate using BaFi:Eu.

PubMed

Nanto, H; Araki, T; Daimon, M; Kusano, E; Kinbara, A; Kawabata, K; Nakano, Y

2002-01-01

BaFI:Eu phosphors are fabricated using a new method of synthesis: liquid phase synthesis, in which the phosphor particles are formed through the association of Ba2+ ions, F-ions and Eu2+ ions in solution. An intense optically stimulated luminescence (OSL) peak at about 410 nm is observed by stimulating X ray irradiated BaFI:Eu phosphor with about 550-750 nm light. It is found that the peak wavelength of the optically stimulation spectrum is about 690 nm. This result suggests that the semiconductor laser can be used as the stimulating light source. It is also found that the OSL intensity is increased with increasing the X ray dose. The BaFI:Eu phosphor as a photostimulable material for the imaging plate of a computed radiography system provides the following advantages; (1) high X ray absorption coefficient, (2) high monodispersion in size which would contribute to sharp images, (3) high OSL and thus low luminescence mottle and (4) high DQE (detective quantum efficiency).

Calcium activation of frog slow muscle fibres

PubMed Central

Costantin, L. L.; Podolsky, R. J.; Tice, Lois W.

1967-01-01

1. Skinned muscle fibres were prepared from the tonus bundle of the frog iliofibularis muscle and the contractile response elicited by applied calcium ions was studied. The fibre type was determined by electron microscopy. 2. Fast fibres shortened many times more rapidly than slow fibres, indicating that the slow contraction of slow fibres is an inherent property of the contractile mechanism. 3. The extent of spread of contraction following local calcium application was much greater in slow than in fast fibres, a difference which is consistent with the relative sparsity of the sarcoplasmic reticulum in slow fibres. 4. The ability of the sarcoplasmic reticulum of slow fibres to accumulate calcium was demonstrated by the in situ immobilization of calcium when oxalate solutions were added to the skinned fibre. ImagesPlate 1Plate 2Plate 3Plate 4Plate 5AB PMID:6030519

An improved plating process

NASA Technical Reports Server (NTRS)

Askew, John C.

1994-01-01

An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

Development of an ion time-of-flight spectrometer for neutron depth profiling

NASA Astrophysics Data System (ADS)

Cetiner, Mustafa Sacit

Ion time-of-flight spectrometry techniques are investigated for applicability to neutron depth profiling. Time-of-flight techniques are used extensively in a wide range of scientific and technological applications including energy and mass spectroscopy. Neutron depth profiling is a near-surface analysis technique that gives concentration distribution versus depth for certain technologically important light elements. The technique uses thermal or sub-thermal neutrons to initiate (n, p) or (n, alpha) reactions. Concentration versus depth distribution is obtained by the transformation of the energy spectrum into depth distribution by using stopping force tables of the projectiles in the substrate, and by converting the number of counts into concentration using a standard sample of known dose value. Conventionally, neutron depth profiling measurements are based on charged particle spectrometry, which employs semiconductor detectors such as a surface barrier detector (SBD) and the associated electronics. Measurements with semiconductor detectors are affected by a number of broadening mechanisms, which result from the interactions between the projectile ion and the detector material as well as fluctuations in the signal generation process. These are inherent features of the detection mechanism that involve the semiconductor detectors and cannot be avoided. Ion time-of-flight spectrometry offers highly precise measurement capabilities, particularly for slow particles. For high-energy low-mass particles, measurement resolution tends to degrade with all other parameters fixed. The threshold for more precise ion energy measurements with respect to conventional techniques, such as direct energy measurement by a surface barrier detector, is directly related to the design and operating parameters of the device. Time-of-flight spectrometry involves correlated detection of two signals by a coincidence unit. In ion time-of-flight spectroscopy, the ion generates the primary input signal. Without loss of generality, the secondary signal is obtained by the passage of the ion through a thin carbon foil, which produces ion-induced secondary electron emission (IISEE). The time-of-flight spectrometer physically acts as an ion/electron separator. The electrons that enter the active volume of the spectrometer are transported onto the microchannel plate detector to generate the secondary signal. The electron optics can be designed in variety of ways depending on the nature of the measurement and physical requirements. Two ion time-of-flight spectrometer designs are introduced: the parallel electric and magnetic (PEM) field spectrometer and the cross electric and magnetic (CEM) field spectrometer. The CEM field spectrometers have been extensively used in a wide range of applications where precise mass differentiation is required. The PEM field spectrometers have lately found interest in mass spectroscopy applications. The application of the PEM field spectrometer for energy measurements is a novel approach. The PEM field spectrometer used in the measurements employs axial electric and magnetic fields along the nominal direction of the incident ion. The secondary electrons are created by a thin carbon foil on the entrance disk and transported on the microchannel plate that faces the carbon foil. The initial angular distribution of the secondary electrons has virtually no effect on the transport time of the secondary electrons from the surface of the carbon foil to the electron microchannel plate detector. Therefore, the PEM field spectrometer can offer high-resolution energy measurement for relatively lower electric fields. The measurements with the PEM field spectrometer were made with the Tandem linear particle accelerator at the IBM T. J. Watson Research Center at Yorktown Heights, NY. The CEM field spectrometer developed for the thesis employs axial electric field along the nominal direction of the ion, and has perpendicular magnetic field. As the electric field accelerates and then decelerates the emitted secondary electron beam, the magnetic field steers the beam away from the source and focuses it onto the electron microchannel plate detector. The initial momentum distribution of the electron beam is observed to have profound effect on the electron transport time. Hence, the CEM field spectrometer measurements suffer more from spectral broadening at similar operating parameters. The CEM field spectrometer measurements were obtained with a 210Po alpha source at the Penn State Radiation Science and Engineering Center, University Park, PA. Although the PEM field spectrometer suffers less from electron transport time dispersion, the CEM field spectrometer is more suited for application to neutron depth profiling. The multiple small-diameter apertures used in the PEM field configuration considerably reduces the geometric efficiency of the spectrometer. Most of the neutron depth profiling measurements, where isotropic emission of charged particles is observed, have relatively low count rates; hence, high detection efficiency is essential.

Identification of microorganisms using superconducting tunnel junctions and time-of-flight mass spectrometry

NASA Astrophysics Data System (ADS)

Ullom, J. N.; Frank, M.; Horn, J. M.; Labov, S. E.; Langry, K.; Benner, W. H.

2000-04-01

We present time-of-flight measurements of biological material ejected from bacterial spores following laser irradiation. Ion impacts are registered on a microchannel plate detector and on a Superconducting Tunnel Junction (STJ) detector. We compare mass spectra obtained with the two detectors. The STJ has better sensitivity to massive ions and also measures the energy of each ion. We show evidence that spores of different bacillus species produce distinctive mass spectra and associate the observed mass peaks with coat proteins.

Planar techniques for fabricating X-ray diffraction gratings and zone plates

NASA Technical Reports Server (NTRS)

Smith, H. I.; Anderson, E. H.; Hawryluk, A. M.; Schattenburg, M. L.

1984-01-01

The state of current planar techniques in the fabrication of Fresnel zone plates and diffraction gratings is reviewed. Among the fabrication techniques described are multilayer resist techniques; scanning electron beam lithography; and holographic lithography. Consideration is also given to: X-ray lithography; ion beam lithography; and electroplating. SEM photographs of the undercut profiles obtained in a type AZ 135OB photoresistor by holographic lithography are provided.

The Analysis of Metal Finishing Solutions by Ion Chromatography

DTIC Science & Technology

1987-08-01

Chromatographic Instrumentation ...... 33 2.3 Modes of Separation .................. 35 2.4 Modes of Detection ................... 44 2.5 Method Development...Chromium Plating Solutions a and R with Added HCl ..................... 151 Table 35 . Chromium Plating Solutions a and R with Added NaOH...Dm (20) HETPld= Zd Dm / U (21) HETPsm= Zsm dp dp U / Dm (22) HETPsp= Zs dp dp U / Ds (23) where: dp- Particle diameter. Dm= Solute mobile phase

Microbiological Quality Assessment of Game Meats at Retail in Japan.

PubMed

Asakura, Hiroshi; Kawase, Jun; Ikeda, Tetsuya; Honda, Mioko; Sasaki, Yoshimasa; Uema, Masashi; Kabeya, Hidenori; Sugiyama, Hiromu; Igimi, Shizunobu; Takai, Shinji

2017-12-01

In this study, we examined the prevalence of Shiga toxin-producing Escherichia coli and Salmonella spp. and the distribution of indicator bacteria in 248 samples of game meats (120 venison and 128 wild boar) retailed between November 2015 and March 2016 in Japan. No Salmonella spp. were detected in any of the samples, whereas Shiga toxin-producing Escherichia coli serotype OUT:H25 (stx 2d + , eae - ) was isolated from one deer meat sample, suggesting a possible source for human infection. Plate count assays indicated greater prevalence of coliforms and E. coli in wild boar meat than in venison, whereas their prevalence in processing facilities showed greater variation than in animal species. The 16S rRNA ion semiconductor sequencing analysis of 24 representative samples revealed that the abundances of Acinetobacter and Arthrobacter spp. significantly correlated with the prevalence of E. coli, and quantitative PCR analyses in combination with selective plate count assay verified these correlations. To our knowledge, this is the first report to characterize the diversity of microorganisms of game meats at retail in Japan, together with identification of dominant microbiota. Our data suggest the necessity of bottom-up hygienic assessment in areas of slaughtering and processing facilities to improve microbiological safety.

Optimization of high count rate event counting detector with Microchannel Plates and quad Timepix readout

NASA Astrophysics Data System (ADS)

Tremsin, A. S.; Vallerga, J. V.; McPhate, J. B.; Siegmund, O. H. W.

2015-07-01

Many high resolution event counting devices process one event at a time and cannot register simultaneous events. In this article a frame-based readout event counting detector consisting of a pair of Microchannel Plates and a quad Timepix readout is described. More than 104 simultaneous events can be detected with a spatial resolution of 55 μm, while >103 simultaneous events can be detected with <10 μm spatial resolution when event centroiding is implemented. The fast readout electronics is capable of processing >1200 frames/sec, while the global count rate of the detector can exceed 5×108 particles/s when no timing information on every particle is required. For the first generation Timepix readout, the timing resolution is limited by the Timepix clock to 10-20 ns. Optimization of the MCP gain, rear field voltage and Timepix threshold levels are crucial for the device performance and that is the main subject of this article. These devices can be very attractive for applications where the photon/electron/ion/neutron counting with high spatial and temporal resolution is required, such as energy resolved neutron imaging, Time of Flight experiments in lidar applications, experiments on photoelectron spectroscopy and many others.

Fuel cell plates with skewed process channels for uniform distribution of stack compression load

DOEpatents

Granata, Jr., Samuel J.; Woodle, Boyd M.

1989-01-01

An electrochemical fuel cell includes an anode electrode, a cathode electrode, an electrolyte matrix sandwiched between electrodes, and a pair of plates above and below the electrodes. The plate above the electrodes has a lower surface with a first group of process gas flow channels formed thereon and the plate below the electrodes has an upper surface with a second group of process gas flow channels formed thereon. The channels of each group extend generally parallel to one another. The improvement comprises the process gas flow channels on the lower surface of the plate above the anode electrode and the process gas flow channels on the upper surface of the plate below the cathode electrode being skewed in opposite directions such that contact areas of the surfaces of the plates through the electrodes are formed in crisscross arrangements. Also, the plates have at least one groove in areas of the surfaces thereof where the channels are absent for holding process gas and increasing electrochemical activity of the fuel cell. The groove in each plate surface intersects with the process channels therein. Also, the opposite surfaces of a bipolar plate for a fuel cell contain first and second arrangements of process gas flow channels in the respective surfaces which are skewed the same amount in opposite directions relative to the longitudinal centerline of the plate.

Graphene-based supercapacitors in the parallel-plate electrode configuration: ionic liquids versus organic electrolytes.

PubMed

Shim, Youngseon; Kim, Hyung J; Jung, Younjoon

2012-01-01

Supercapacitors with two single-sheet graphene electrodes in the parallel plate geometry are studied via molecular dynamics (MD) computer simulations. Pure 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI+BF4-) and a 1.1 M solution of EMI+BF4- in acetonitrile are considered as prototypes of room-temperature ionic liquids (RTILs) and organic electrolytes. Electrolyte structure, charge density and associated electric potential are investigated by varying the charges and separation of the two electrodes. Multiple charge layers formed in the electrolytes in the vicinity of the electrodes are found to screen the electrode surface charge almost completely. As a result, the supercapacitors show nearly an ideal electric double layer behavior, i.e., the electric potential exhibits essentially a plateau behavior in the entire electrolyte region except for sharp changes in screening zones very close to the electrodes. Due to its small size and large charge separation, BF4- is considerably more efficient in shielding electrode charges than EMI+. In the case of the acetonitrile solution, acetonitrile also plays an important role by aligning its dipoles near the electrodes; however, the overall screening mainly arises from ions. Because of the disparity of shielding efficiency between cations and anions, the capacitance of the positively-charged anode is significantly larger than that of the negatively-charged cathode. Therefore, the total cell capacitance in the parallel plate configuration is primarily governed by the cathode. Ion conductivity obtained via the Green-Kubo (GK) method is found to be largely independent of the electrode surface charge. Interestingly, EMI+BF4- shows higher GK ion conductivity than the 1.1 M acetonitrile solution between two parallel plate electrodes.

Chemical Passivation of Li(exp +)-Conducting Solid Electrolytes

NASA Technical Reports Server (NTRS)

West, William; Whitacre, Jay; Lim, James

2008-01-01

Plates of a solid electrolyte that exhibits high conductivity for positive lithium ions can now be passivated to prevent them from reacting with metallic lithium. Such passivation could enable the construction and operation of high-performance, long-life lithium-based rechargeable electrochemical cells containing metallic lithium anodes. The advantage of this approach, in comparison with a possible alternative approach utilizing lithium-ion graphitic anodes, is that metallic lithium anodes could afford significantly greater energy-storage densities. A major impediment to the development of such cells has been the fact that the available solid electrolytes having the requisite high Li(exp +)-ion conductivity are too highly chemically reactive with metallic lithium to be useful, while those solid electrolytes that do not react excessively with metallic lithium have conductivities too low to be useful. The present passivation method exploits the best features of both extremes of the solid-electrolyte spectrum. The basic idea is to coat a higher-conductivity, higher-reactivity solid electrolyte with a lower-conductivity, lower-reactivity solid electrolyte. One can then safely deposit metallic lithium in contact with the lower-reactivity solid electrolyte without incurring the undesired chemical reactions. The thickness of the lower-reactivity electrolyte must be great enough to afford the desired passivation but not so great as to contribute excessively to the electrical resistance of the cell. The feasibility of this method was demonstrated in experiments on plates of a commercial high-performance solid Li(exp +)- conducting electrolyte. Lithium phosphorous oxynitride (LiPON) was the solid electrolyte used for passivation. LiPON-coated solid-electrolyte plates were found to support electrochemical plating and stripping of Li metal. The electrical resistance contributed by the LiPON layers were found to be small relative to overall cell impedances.

Role of Spatial Ionic Distribution on the Energetics of Hydrophobic Assembly and Properties of the Water/Hydrophobe Interface†

PubMed Central

Bauer, Brad A.; Ou, Shuching; Patel, Sandeep

2014-01-01

We present results from all-atom molecular dynamics simulations of large-scale hydrophobic plates solvated in NaCl and NaI salt solutions. As observed in studies of ions at the air-water interface, the density of iodide near the water-plate interface is significantly enhanced relative to chloride and in the bulk. This allows for the partial hydration of iodide while chloride remains more fully hydrated. In 1M solutions, iodide directly pushes the hydrophobes together (contributing −2.51 kcal/mol) to the PMF. Chloride, however, strengthens the water-induced contribution to the PMF by ~ −2.84 kcal/mol. These observations are enhanced in 3M solutions, consistent with the increased ion density in the vicinity of the hydrophobes. The different salt solutions influence changes in the critical hydrophobe separation distance and characteristic wetting/dewetting transitions. These differences are largely influenced by the ion-specific expulsion of iodide from bulk water. Results of this study are of general interest to the study of ions at interfaces and may lend insight to the mechanisms underlying the Hofmeister series. PMID:22231014

Operando lithium plating quantification and early detection of a commercial LiFePO4 cell cycled under dynamic driving schedule

NASA Astrophysics Data System (ADS)

Anseán, D.; Dubarry, M.; Devie, A.; Liaw, B. Y.; García, V. M.; Viera, J. C.; González, M.

2017-07-01

Lithium plating is considered one of the most detrimental phenomenon in lithium ion batteries (LIBs), as it increases cell degradation and might lead to safety issues. Plating induced LIB failure presents a major concern for emerging applications in transportation and electrical energy storage. Hence, the necessity to operando monitor, detect and analyze lithium plating becomes critical for safe and reliable usage of LIB systems. Here, we report in situ lithium plating analyses for a commercial graphite||LiFePO4 cell cycled under dynamic stress test (DST) driving schedule. We designed a framework based on incremental capacity (IC) analysis and mechanistic model simulations to quantify degradation modes, relate their effects to lithium plating occurrence and assess cell degradation. The results show that lithium plating was induced by large loss of active material on the negative electrode that eventually led the electrode to over-lithiate. Moreover, when lithium plating emerged, we quantified that the loss of lithium inventory pace was increased by a factor of four. This study illustrates the benefits of the proposed framework to improve lithium plating analysis. It also discloses the symptoms of lithium plating formation, which prove valuable for novel, online strategies on early lithium plating detection.

Corrosion behavior and surface structure of orthodontic Ni-Ti alloy wires.

PubMed

Iijima, M; Endo, K; Ohno, H; Yonekura, Y; Mizoguchi, I

2001-03-01

The corrosion behaviors of a commercial Ni-Ti alloy orthodontic wire and a polished plate with same composition in 0.9% NaCl and 1% lactic acid solutions were examined using an electrochemical technique, an analysis of released ions, and a surface analysis by X-ray photoelectron spectroscopy (XPS). The effect of polishing the wire on the corrosion was also examined. The XPS analysis demonstrated the presence of a thick oxide film mainly composed of TiO2 with trace amounts of Ni hydroxide, which had formed on the wire surface during the heat treatment and subsequent pickling processes. This oxide layer contributed to the higher resistance of the as-received wire to both general and localized corrosion in 0.9% NaCl solution, compared with that of the polished plate and the polished wire. The thick oxide layer, however, was not stable and did not protect the orthodontic wire from corrosion in 0.1% lactic acid solution.

Study on Silver-plated Molybdenum Interconnected Materials for LEO Solar Cell Array

NASA Astrophysics Data System (ADS)

Zhu, Jia-jun; Hu, Yu-hao; Xu, Meng; Yang, Wu-lin; Fu, Li-cai; Li, De-yi; Zhou, Ling-ping

2017-09-01

Atomic oxygen (AO) is one of the most important environmental factors that affected the performance of low earth orbit spacecraft in orbit. In which, silver was the most common materials as the interconnected materials. However, with the poor AO resistance of silver, the interconnectors could be failure easier, and the lifetime of the spacecraft was also reduced. In this paper, the silver-plated molybdenum interconnected materials made by Ag thin films deposited on the Mo foils by vacuum deposition methods was studied. And the effects of the preparation process on the micro-structure of the Ag thin films, the interfacial adhesive strength and the electrical conductivity of the composites were investigated. It was found that the Ag thin films deposited on the Mo substrates coated the Ag thin films by ion beam assisted deposition(IBAD) methods exhibited a perfectly (200) preferred orientation. The interfacial adhesive strength had been increased to 18.58MPa. And the composites also have excellent electrical performance.

Potentiodynamic studies of Ni-P-TiO{sub 2} nano-composited coating on the mild steel deposited by electroless plating method

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

Uttam, Vibha, E-mail: vibhauttam74@gmail.com; Duchaniya, R. K., E-mail: rkduchaniya.meta@mnit.ac.in

2016-05-06

Now a days, corrosion studies are important for reducing the wastage of metals. The importance of corrosion studies is two folds i.e. first is economic, including the reduction of material losses resulting from the wasting away or sudden failure of materials and second is conservation Electroless process is an autocatalytic reduction method in which metallic ions are reduced in the solution. Nanocomposite coatings of Ni-P-TiO{sub 2} on mild steel are deposited by varying volume of TiO{sub 2} nano-powder by electroless method from Ni-P plating bath containing Nickel Sulphate as a source of nickel ions, sodium hypophosphite as the reducing agent,more » lactic acid as a complexing agents and TiO{sub 2} nano powder. Electroless Ni-P-TiO{sub 2} coating have been widely used in the chemical process industries, mechanical industries, electronic industries and chloroalkali industries due to their excellent corrosion with mechanical properties. In the present work, deposition of Ni-P alloy coating and Ni-P-TiO{sub 2} nanocomposited coatings were done on the mild steel and corrosion properties were studied with Potentio-dynamic polarization measurements method in 3.5 wt% sodium chloride solution. It showed in the experiments that Ni-P-TiO{sub 2} nanocomposited coating has better corrosion resistance as comparedthan Ni-P alloy coating. Morphological studies were done by field emission scanning electron microscopy (FESEM), energy–dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD). These studies confirmed the deposition of Ni-P alloy coating and Ni-P-TiO{sub 2} nanocomposited coating.« less

Simulations of particle and heat fluxes in an ELMy H-mode discharge on EAST using BOUT++ code

NASA Astrophysics Data System (ADS)

Wu, Y. B.; Xia, T. Y.; Zhong, F. C.; Zheng, Z.; Liu, J. B.; team3, EAST

2018-05-01

In order to study the distribution and evolution of the transient particle and heat fluxes during edge-localized mode (ELM) bursts on the Experimental Advanced Superconducting Tokamak (EAST), the BOUT++ six-field two-fluid model is used to simulate the pedestal collapse. The profiles from the EAST H-mode discharge #56129 are used as the initial conditions. Linear analysis shows that the resistive ballooning mode and drift-Alfven wave are two dominant instabilities for the equilibrium, and play important roles in driving ELMs. The evolution of the density profile and the growing process of the heat flux at divertor targets during the burst of ELMs are reproduced. The time evolution of the poloidal structures of T e is well simulated, and the dominant mode in each stage of the ELM crash process is found. The studies show that during the nonlinear phase, the dominant mode is 5, and it changes to 0 when the nonlinear phase goes to saturation after the ELM crash. The time evolution of the radial electron heat flux, ion heat flux, and particle density flux at the outer midplane (OMP) are obtained, and the corresponding transport coefficients D r, χ ir, and χ er reach maximum around 0.3 ∼ 0.5 m2 s‑1 at ΨN = 0.9. The heat fluxes at outer target plates are several times larger than that at inner target plates, which is consistent with the experimental observations. The simulated profiles of ion saturation current density (j s) at the lower outboard (LO) divertor target are compared to those of experiments by Langmuir probes. The profiles near the strike point are similar, and the peak values of j s from simulation are very close to the measurements.

Improvement of a plasma uniformity of the 2nd ion source of KSTAR neutral beam injector.

PubMed

Jeong, S H; Kim, T S; Lee, K W; Chang, D H; In, S R; Bae, Y S

2014-02-01

The 2nd ion source of KSTAR (Korea Superconducting Tokamak Advanced Research) NBI (Neutral Beam Injector) had been developed and operated since last year. A calorimetric analysis revealed that the heat load of the back plate of the ion source is relatively higher than that of the 1st ion source of KSTAR NBI. The spatial plasma uniformity of the ion source is not good. Therefore, we intended to identify factors affecting the uniformity of a plasma density and improve it. We estimated the effects of a direction of filament current and a magnetic field configuration of the plasma generator on the plasma uniformity. We also verified that the operation conditions of an ion source could change a uniformity of the plasma density of an ion source.

Sputter deposition for multi-component thin films

DOEpatents

Krauss, A.R.; Auciello, O.

1990-05-08

Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams. 10 figs.

Sputter deposition for multi-component thin films

DOEpatents

Krauss, Alan R.; Auciello, Orlando

1990-01-01

Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams.

WSi2/Si multilayer sectioning by reactive ion etching for multilayer Laue lens fabrication

NASA Astrophysics Data System (ADS)

Bouet, N.; Conley, R.; Biancarosa, J.; Divan, R.; Macrander, A. T.

2010-09-01

Reactive ion etching (RIE) has been employed in a wide range of fields such as semiconductor fabrication, MEMS (microelectromechanical systems), and refractive x-ray optics with a large investment put towards the development of deep RIE. Due to the intrinsic differing chemistries related to reactivity, ion bombardment, and passivation of materials, the development of recipes for new materials or material systems can require intense effort and resources. For silicon in particular, methods have been developed to provide reliable anisotropic profiles with good dimensional control and high aspect ratios1,2,3, high etch rates, and excellent material to mask etch selectivity. A multilayer Laue lens4 is an x-ray focusing optic, which is produced by depositing many layers of two materials with differing electron density in a particular stacking sequence where the each layer in the stack satisfies the Fresnel zone plate law. When this stack is sectioned to allow side-illumination with radiation, the diffracted exiting radiation will constructively interfere at the focal point. Since the first MLLs were developed at Argonne in the USA in 20064, there have been published reports of MLL development efforts in Japan5, and, very recently, also in Germany6. The traditional technique for sectioning multilayer Laue lens (MLL) involves mechanical sectioning and polishing7, which is labor intensive and can induce delamination or structure damage and thereby reduce yield. If a non-mechanical technique can be used to section MLL, it may be possible to greatly shorten the fabrication cycle, create more usable optics from the same amount of deposition substrate, and perhaps develop more advanced structures to provide greater stability or flexibility. Plasma etching of high aspect-ratio multilayer structures will also expand the scope for other types of optics fabrication (such as gratings, zone plates, and so-on). However, well-performing reactive ion etching recipes have been developed for only a small number of materials, and even less recipes exist for concurrent etching of more than one element so a fully material specific process needs to be developed. In this paper, sectioning of WSi2/Si multilayers for MLL fabrication using fluorinated gases is investigated. The main goals were to demonstrate the feasibility of this technique, achievement of high anisotropy, adequate sidewall roughness control and high etching rates. We note that this development for MLL sidewalls should be distinguished from work on improving aspect ratios in traditional Fresnel zone plates. Aspect ratios for MLL sidewalls are not similarly constrained.

Temperature Compensation of Aluminum Nitride Lamb Wave Resonators Utilizing the Lowest-Order Symmetric Mode

DTIC Science & Technology

2012-12-14

PZT ceramic plate [40]. Since then Lamb wave devices utilizing the lowest-order antisymmetric (A0) mode propagation in ZnO thin plate were widely...Million Pt Platinum PVDF Polyvinylidene Flouride PZT Lead Zirconium Titanate Q Quality Factor R Resistor RIE Reactive Ion Etching Rm Motional...GaAs), silicon carbide (SiC), langasite (LGS), lead zirconium titanate ( PZT ), and polyvinylidene flouride (PVDF). Each piezoelectric material has

Sea urchins have teeth? A review of their microstructure, biomineralization, development and mechanical properties

PubMed Central

Stock, Stuart R.

2015-01-01

Sea urchins possess a set of five teeth which are self-sharpening and which continuously replace material lost through abrasion. The continuous replacement dictates that each tooth consists of the range of developmental states from discrete plates in the plumula, the least mineralized and least mature portion, to plates and needle-prisms separated by cellular syncytia at the beginning of the tooth shaft to a highly dense structure at the incisal end. The microstructures and their development are reviewed prior to a discussion of current understanding of the biomineralization processes operating during tooth formation. For example, the mature portions of each tooth consist of single crystal calcite but the early stages of mineral formation (e.g. solid amorphous calcium carbonate, ions in solution) continue to be investigated. The second stage mineral that cements the disparate plates and prisms together has a much higher Mg content than the first stage prisms and needles and allows the tooth to be self-sharpening. Mechanically, the urchin tooth’s calcite performs better than inorganic calcite, and aspects of tooth functionality that are reviewed include the materials properties themselves and the role of the orientations of the plates and prisms relative to the axes of the applied loads. Although the properties and microarchitecture of sea urchin teeth or other mineralized tissues are often described as optimized, this view is inaccurate because these superb solutions to the problem of constructing functional structures are intermediaries not endpoints of evolution. PMID:24437604

Catalytic Reactor For Oxidizing Mercury Vapor

DOEpatents

Helfritch, Dennis J.

1998-07-28

A catalytic reactor (10) for oxidizing elemental mercury contained in flue gas is provided. The catalyst reactor (10) comprises within a flue gas conduit a perforated corona discharge plate (30a, b) having a plurality of through openings (33) and a plurality of projecting corona discharge electrodes (31); a perforated electrode plate (40a, b, c) having a plurality of through openings (43) axially aligned with the through openings (33) of the perforated corona discharge plate (30a, b) displaced from and opposing the tips of the corona discharge electrodes (31); and a catalyst member (60a, b, c, d) overlaying that face of the perforated electrode plate (40a, b, c) opposing the tips of the corona discharge electrodes (31). A uniformly distributed corona discharge plasma (1000) is intermittently generated between the plurality of corona discharge electrode tips (31) and the catalyst member (60a, b, c, d) when a stream of flue gas is passed through the conduit. During those periods when corona discharge (1000) is not being generated, the catalyst molecules of the catalyst member (60a, b, c, d) adsorb mercury vapor contained in the passing flue gas. During those periods when corona discharge (1000) is being generated, ions and active radicals contained in the generated corona discharge plasma (1000) desorb the mercury from the catalyst molecules of the catalyst member (60a, b, c, d), oxidizing the mercury in virtually simultaneous manner. The desorption process regenerates and activates the catalyst member molecules.

Sea urchins have teeth? A review of their microstructure, biomineralization, development and mechanical properties.

PubMed

Stock, Stuart R

2014-01-01

Sea urchins possess a set of five teeth which are self-sharpening and which continuously replace material lost through abrasion. The continuous replacement dictates that each tooth consists of the range of developmental states from discrete plates in the plumula, the least mineralized and least mature portion, to plates and needle-prisms separated by cellular syncytia at the beginning of the tooth shaft to a highly dense structure at the incisal end. The microstructures and their development are reviewed prior to a discussion of current understanding of the biomineralization processes operating during tooth formation. For example, the mature portions of each tooth consist of single crystal calcite but the early stages of mineral formation (e.g. solid amorphous calcium carbonate, ions in solution) continue to be investigated. The second stage mineral that cements the disparate plates and prisms together has a much higher Mg content than the first stage prisms and needles and allows the tooth to be self-sharpening. Mechanically, the urchin tooth's calcite performs better than inorganic calcite, and aspects of tooth functionality that are reviewed include the materials properties themselves and the role of the orientations of the plates and prisms relative to the axes of the applied loads. Although the properties and microarchitecture of sea urchin teeth or other mineralized tissues are often described as optimized, this view is inaccurate because these superb solutions to the problem of constructing functional structures are intermediaries not endpoints of evolution.

iMAST Quarterly, Number 3, 2000

DTIC Science & Technology

2000-01-01

components which depend on evaporating unit capabilities. There are three components (EB-gun, water cooled copper crucible and vacuum chamber) in the EB-PVD...Ion Implantation and Ion Plating electromagnetic deflected through 180 or 2700. Similarly, evaporant material is placed in a water-cooled copper ... crucible , which could be either pocket type for small quantity evaporation application or continuous ingot feeding through the crucible for larger quantity

Stationary and non-stationary occurrences of miniature end plate potentials are well described as stationary and non-stationary Poisson processes in the mollusc Navanax inermis.

PubMed

Cappell, M S; Spray, D C; Bennett, M V

1988-06-28

Protractor muscles in the gastropod mollusc Navanax inermis exhibit typical spontaneous miniature end plate potentials with mean amplitude 1.71 +/- 1.19 (standard deviation) mV. The evoked end plate potential is quantized, with a quantum equal to the miniature end plate potential amplitude. When their rate is stationary, occurrence of miniature end plate potentials is a random, Poisson process. When non-stationary, spontaneous miniature end plate potential occurrence is a non-stationary Poisson process, a Poisson process with the mean frequency changing with time. This extends the random Poisson model for miniature end plate potentials to the frequently observed non-stationary occurrence. Reported deviations from a Poisson process can sometimes be accounted for by the non-stationary Poisson process and more complex models, such as clustered release, are not always needed.

Development of control system of coating of rod hydraulic cylinders

NASA Astrophysics Data System (ADS)

Aizhambaeva, S. Zh; Maximova, A. V.

2018-01-01

In this article, requirements to materials of hydraulic cylinders and methods of eliminating the main factors affecting the quality of the applied coatings rod hydraulic cylinders. The chromium plating process - one of ways of increase of anti-friction properties of coatings rods, stability to the wear and corrosion. The article gives description of differences of the stand-speed chromium plating process from other types of chromium plating that determines a conclusion about cutting time of chromium plating process. Conducting the analysis of technological equipment suggested addressing the modernization of high-speed chromium plating processes by automation and mechanization. Control system developed by design of schematic block diagram of a modernized and stand-speed chromium plating process.

Design consideration of high voltage Ga2O3 vertical Schottky barrier diode with field plate

NASA Astrophysics Data System (ADS)

Choi, J.-H.; Cho, C.-H.; Cha, H.-Y.

2018-06-01

Gallium oxide (Ga2O3) based vertical Schottky barrier diodes (SBDs) were designed for high voltage switching applications. Since p-type Ga2O3 epitaxy growth or p-type ion implantation technique has not been developed yet, a field plate structure was employed in this study to maximize the breakdown voltage by suppressing the electric field at the anode edge. TCAD simulation was used for the physical analysis of Ga2O3 SBDs from which it was found that careful attention must be paid to the insulator under the field plate. Due to the extremely high breakdown field property of Ga2O3, an insulator with both high permittivity and high breakdown field must be used for the field plate formation.

Process for manufacturing hollow fused-silica insulator cylinder

DOEpatents

Sampayan, Stephen E.; Krogh, Michael L.; Davis, Steven C.; Decker, Derek E.; Rosenblum, Ben Z.; Sanders, David M.; Elizondo-Decanini, Juan M.

2001-01-01

A method for building hollow insulator cylinders that can have each end closed off with a high voltage electrode to contain a vacuum. A series of fused-silica round flat plates are fabricated with a large central hole and equal inside and outside diameters. The thickness of each is related to the electron orbit diameter of electrons that escape the material surface, loop, and return back. Electrons in such electron orbits can support avalanche mechanisms that result in surface flashover. For example, the thickness of each of the fused-silica round flat plates is about 0.5 millimeter. In general, the thinner the better. Metal, such as gold, is deposited onto each top and bottom surface of the fused-silica round flat plates using chemical vapor deposition (CVD). Eutectic metals can also be used with one alloy constituent on the top and the other on the bottom. The CVD, or a separate diffusion step, can be used to defuse the deposited metal deep into each fused-silica round flat plate. The conductive layer may also be applied by ion implantation or gas diffusion into the surface. The resulting structure may then be fused together into an insulator stack. The coated plates are aligned and then stacked, head-to-toe. Such stack is heated and pressed together enough to cause the metal interfaces to fuse, e.g., by welding, brazing or eutectic bonding. Such fusing is preferably complete enough to maintain a vacuum within the inner core of the assembled structure. A hollow cylinder structure results that can be used as a core liner in a dielectric wall accelerator and as a vacuum envelope for a vacuum tube device where the voltage gradients exceed 150 kV/cm.

LEICA - A low energy ion composition analyzer for the study of solar and magnetospheric heavy ions

NASA Technical Reports Server (NTRS)

Mason, Glenn M.; Hamilton, Douglas C.; Walpole, Peter H.; Heuerman, Karl F.; James, Tommy L.; Lennard, Michael H.; Mazur, Joseph E.

1993-01-01

The SAMPEX LEICA instrument is designed to measure about 0.5-5 MeV/nucleon solar and magnetospheric ions over the range from He to Ni. The instrument is a time-of-flight mass spectrometer which measures particle time-of-flight over an about 0.5 m path, and the residual energy deposited in an array of Si solid state detectors. Large area microchannel plates are used, resulting in a large geometrical factor for the instrument (0.6 sq cm sr) which is essential for accurate compositional measurements in small solar flares, and in studies of precipitating magnetospheric heavy ions.

Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

NASA Astrophysics Data System (ADS)

Shanks, Richard P.; Ascough, Philippa L.; Dougans, Andrew; Gallacher, Paul; Gulliver, Pauline; Rood, Dylan H.; Xu, Sheng; Freeman, Stewart P. H. T.

2015-10-01

The SUERC bipolar single-stage accelerator mass spectrometer (SSAMS) has been dismantled and rebuilt to accommodate an additional rotatable pre-accelerator electrostatic spherical analyser (ESA) and a second ion source injector. This is for the attachment of an experimental positive-ion electron cyclotron resonance (ECR) ion source in addition to a Cs-sputter source. The ESA significantly suppresses oxygen interference to radiocarbon detection, and remaining measurement interference is now thought to be from 13C injected as 13CH molecule scattering off the plates of a second original pre-detector ESA.

A lattice relaxation algorithm for three-dimensional Poisson-Nernst-Planck theory with application to ion transport through the gramicidin A channel.

PubMed Central

Kurnikova, M G; Coalson, R D; Graf, P; Nitzan, A

1999-01-01

A lattice relaxation algorithm is developed to solve the Poisson-Nernst-Planck (PNP) equations for ion transport through arbitrary three-dimensional volumes. Calculations of systems characterized by simple parallel plate and cylindrical pore geometries are presented in order to calibrate the accuracy of the method. A study of ion transport through gramicidin A dimer is carried out within this PNP framework. Good agreement with experimental measurements is obtained. Strengths and weaknesses of the PNP approach are discussed. PMID:9929470

A colorimetric turn-on optical chemosensor for Cu2+ ions and its application as solid state sensor

NASA Astrophysics Data System (ADS)

Pannipara, Mehboobali; Al-Sehemi, Abdullah G.; Assiri, Mohammed; Kalam, Abul

2018-05-01

We report a novel coumarin based optical chemosensor (Probe 1) for the selective and sensitive detection of Cu2+ ions in aqueous medium. The addition of Cu2+ ions to Probe 1 shows distinct color change from light yellow to pinkish red color under visible light with the sensing limit of 1.54 μM. Moreover, practical utility of Probe 1 as solid state optical sensor (test paper, TLC plates) for sensing Cu2+ has been demonstrated by instantaneous "naked eye" response.

Lasting mantle scars lead to perennial plate tectonics.

PubMed

Heron, Philip J; Pysklywec, Russell N; Stephenson, Randell

2016-06-10

Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a 'perennial' phenomenon.

Lasting mantle scars lead to perennial plate tectonics

PubMed Central

Heron, Philip J.; Pysklywec, Russell N.; Stephenson, Randell

2016-01-01

Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a ‘perennial' phenomenon. PMID:27282541

New high-resolution electrostatic ion mass analyzer using time of flight

NASA Technical Reports Server (NTRS)

Hamilton, D. C.; Gloeckler, G.; Ipavich, F. M.; Lundgren, R. A.; Sheldon, R. B.

1990-01-01

The design of a high-resolution ion-mass analyzer is described, which is based on an accurate measurement of the time of flight (TOF) of ions within a region configured to produce a harmonic potential. In this device, the TOF, which is independent of ion energy, is determined from a start pulse from secondary electrons produced when the ion passes through a thin carbon foil at the entrance of the TOF region and at a stop pulse from the ion striking a microchannel plate upon exciting the region. A laboratory prototype instrument called 'VMASS' was built and was tested at the Goddard Space Flight Center electrostatic accelerator, showing a good mass resolution of the instrument. Sensors of the VMASS type will form part of the WIND Solar Wind and Suprathermal Ion experiment, the Soho mission, and the Advanced Composition Explorer.

Turbulent Transport of Fast Ions in the Large Plasma Device (LAPD)

NASA Astrophysics Data System (ADS)

Zhou, Shu; Heidbrink, William; McWilliams, Roger; Boehmer, Heinrich; Carter, Troy; Popovich, Pavel; Tripathi, Shreekrishna; Vincena, Steve; Jenko, Frank

2010-11-01

Due to gyroradius averaging and drift-orbit averaging, the transport of fast ions by microturbulence is often smaller than for thermal ions. In this experiment, Strong drift wave turbulence is observed in LAPD on gradients produced by a plate obstacle. Energetic lithium ions orbit through the turbulent region. Scans with a collimated analyzer and with probes give detailed profiles of the fast ion spatial distribution and of the fluctuating fields. The fast-ion transport decreases rapidly with increasing fast-ion gyroradius. Unlike the diffusive transport caused by Coulomb collisions, in this case the turbulent transport is non-diffusive. Analysis and simulation suggest that the fast ions interact ballistically with stationary two-dimensional electrostatic turbulence. The energy dependence of the transport is well explained by gyro-averaging theory. In new experiments, different sources and obstacles alter the drift-wave turbulence to modify the nature of the transport.

A pixel detector system for laser-accelerated ion detection

NASA Astrophysics Data System (ADS)

Reinhardt, S.; Draxinger, W.; Schreiber, J.; Assmann, W.

2013-03-01

Laser ion acceleration is an unique acceleration process that creates ultra-short ion pulses of high intensity ( > 107 ions/cm2/ns), which makes online detection an ambitious task. Non-electronic detectors such as radio-chromic films (RCF), imaging plates (IP) or nuclear track detectors (e.g. CR39) are broadly used at present. Only offline information on ion pulse intensity and position are available by these detectors, as minutes to hours of processing time are required after their exposure. With increasing pulse repetition rate of the laser system, there is a growing need for detection of laser accelerated ions in real-time. Therefore, we have investigated a commercial pixel detector system for online detection of laser-accelerated proton pulses. The CMOS imager RadEye1 was chosen, which is based on a photodiode array, 512 × 1024 pixels with 48 μm pixel pitch, thus offering a large sensitive area of approximately 25 × 50 mm2. First detection tests were accomplished at the conventional electrostatic 14 MV Tandem accelerator in Munich as well as Atlas laser accelerator. Detector response measurements at the conventional accelerator have been accomplished in a proton beam in dc (15 MeV) and pulsed (20 MeV) irradiation mode, the latter providing comparable particle flux as under laser acceleration conditions. Radiation hardness of the device was studied using protons (20 MeV) and C-ions (77 MeV), additionally. The detector system shows a linear response up to a maximum pulse flux of about 107 protons/cm2/ns. Single particle detection is possible in a low flux beam (104 protons/cm2/s) for all investigated energies. The radiation hardness has shown to give reasonable lifetime for an application at the laser accelerator. The results from the irradiation at a conventional accelerator are confirmed by a cross-calibration with CR39 in a laser-accelerated proton beam at the MPQ Atlas Laser in Garching, showing no problems of detector operation in presence of electro-magnetic pulse (EMP). The calibrated detector system was finally used for online detection of laser-accelerated proton and carbon ions at the Astra-Gemini laser.

Preparation of a bonelike apatite-polymer fiber composite using a simple biomimetic process.

PubMed

Yokoyama, Yoshiro; Oyane, Ayako; Ito, Atsuo

2008-08-01

A bonelike apatite-polymer fiber composite may be useful as an implant material to replace bone, the enthesis of a tendon, and the joint part of a ligament. We treated an ethylene-vinyl alcohol copolymer (EVOH) plate and knitted EVOH fibers with an oxygen plasma to produce oxygen-containing functional groups on their surfaces. The plasma-treated samples were alternately dipped in alcoholic calcium and phosphate ion solutions three times to deposit apatite precursors onto their surfaces. The surface-modified samples formed a dense and uniform bonelike surface apatite layer after immersion for 24 h in a simulated body fluid with ion concentrations approximately equal to those of human blood plasma. The adhesive strength between the apatite layer and the sample's surface increased with increasing power density of the oxygen plasma. The apatite-EVOH fiber composite obtained by our process has similarities to natural bone in that apatite crystals are deposited on organic polymer fibers. The resulting composite would possess osteoconductivity due to the apatite phase. With proper polymer selection and optimized synthesis techniques, a composite could be made that would have bonelike mechanical properties. Hence, the present surface modification and coating process would be a promising route to obtain new implant materials with bonelike mechanical properties and osteoconductivity. (c) 2007 Wiley Periodicals, Inc.

Lubricant evaluation of the alpha and beta joints, phase 2

NASA Technical Reports Server (NTRS)

Kannel, J. W.; Stockwell, R. D.

1992-01-01

A research study was conducted to evaluate dry film lubrication of long life space components such as the alpha and beta joints of the Space Station. The problem addressed in the report pertains to the longevity of sputtered MoS2 or ion plated lead films in a rolling contact environment. A special technique was devised for the experiments, which incorporated a coated ball cyclically loaded against a flat plate. At fixed intervals the surface of the coating was photographed at 100X magnification. By computer scanning the photographs, the rate of coating loss was determined. Experimental variables include load and surface finish of the plate. A theory was developed to analyze the state of stress between ball and flat. The stress condition in the ball apparatus was related to the state of stress under rolling contact conditions. Based on the experiments life appeared to decrease with increasing load and increasing surface roughness. An ion plated lead film gave better life than a sputtered MoS2 film. However, by keeping the interfacial shear stress at a low level, adequate coating life was achieved for either coating. For the lead film, the critical stress was about 0.19 GPa (28 ksi). The study dealt only with mechanical wear. Before a coating is selected for a critical space application, other factors such as reaction with atomic oxygen must also be considered.

Calibration of a Thomson parabola ion spectrometer and Fujifilm imaging plate detectors for protons, deuterons, and alpha particles.

PubMed

Freeman, C G; Fiksel, G; Stoeckl, C; Sinenian, N; Canfield, M J; Graeper, G B; Lombardo, A T; Stillman, C R; Padalino, S J; Mileham, C; Sangster, T C; Frenje, J A

2011-07-01

A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane can be used to determine the particle energy. The position dispersion of both the electric and magnetic fields of the Thomson parabola was measured using monoenergetic proton and alpha particle beams from the SUNY Geneseo 1.7 MV tandem Pelletron accelerator. The sensitivity of Fujifilm BAS-TR imaging plates, used as a detector in the Thomson parabola, was also measured as a function of the incident particle energy over the range from 0.6 MeV to 3.4 MeV for protons and deuterons and from 0.9 MeV to 5.4 MeV for alpha particles. The device was used to measure the energy spectrum of laser-produced protons at MTW.

Layered double hydroxide using hydrothermal treatment: morphology evolution, intercalation and release kinetics of diclofenac sodium

NASA Astrophysics Data System (ADS)

Joy, Mathew; Iyengar, Srividhya J.; Chakraborty, Jui; Ghosh, Swapankumar

2017-12-01

The present work demonstrates the possibilities of hydrothermal transformation of Zn-Al layered double hydroxide (LDH) nanostructure by varying the synthetic conditions. The manipulation in washing step before hydrothermal treatment allows control over crystal morphologies, size and stability of their aqueous solutions. We examined the crystal growth process in the presence and the absence of extra ions during hydrothermal treatment and its dependence on the drug (diclofenac sodium (Dic-Na)) loading and release processes. Hexagonal plate-like crystals show sustained release with ˜90% of the drug from the matrix in a week, suggesting the applicability of LDH nanohybrids in sustained drug delivery systems. The fits to the release kinetics data indicated the drug release as a diffusion-controlled release process. LDH with rod-like morphology shows excellent colloidal stability in aqueous suspension, as studied by photon correlation spectroscopy.

Wide-range radioactive-gas-concentration detector

DOEpatents

Anderson, D.F.

1981-11-16

A wide-range radioactive-gas-concentration detector and monitor capable of measuring radioactive-gas concentrations over a range of eight orders of magnitude is described. The device is designed to have an ionization chamber sufficiently small to give a fast response time for measuring radioactive gases but sufficiently large to provide accurate readings at low concentration levels. Closely spaced parallel-plate grids provide a uniform electric field in the active region to improve the accuracy of measurements and reduce ion migration time so as to virtually eliminate errors due to ion recombination. The parallel-plate grids are fabricated with a minimal surface area to reduce the effects of contamination resulting from absorption of contaminating materials on the surface of the grids. Additionally, the ionization-chamber wall is spaced a sufficient distance from the active region of the ionization chamber to minimize contamination effects.

Effects of H3O+, OH-, \\text{O}_{2}^{-} , \\text{NO}_{\\text{x}}^{-} and NO x for Escherichia coli inactivation in atmospheric pressure DC corona discharges

NASA Astrophysics Data System (ADS)

Sekimoto, Kanako; Gonda, Rena; Takayama, Mitsuo

2015-08-01

The effects of ionic and neutral species such as H3O+, OH-, \\text{O}2- , \\text{NO}x- (x = 2, 3), and NO x on Escherichia coli (E. coli) inactivation in gas and liquid phases was investigated using atmospheric pressure DC corona discharges with point-to-plane electrodes. The above chemical species as well as OH and O3 were selectively irradiated onto E. coli suspensions on agar plates using a needle angle of 45° with respect to the plates, airflow, and a grid plate. Irradiation with the positive ion H3O+ did not inactivate E. coli, while the negative ions OH-/\\text{O}2- resulted in bactericidal inactivation, in both gas and liquid phases. In contrast, the negative ions \\text{NO}x- and neutral species NO x in the gas phase had quite strong bactericidal effects on E. coli compared to those species in the liquid phase. These results suggest that liquid-phase HNO3, formed primarily via the reaction of gas-phase \\text{NO}x- and NO x with H2O in agar, has only a weak inactivation effect on E. coli. Furthermore, using naphthylethylenediamine spectrophotometry, the threshold amount of gas-phase \\text{NO}x- and NO x for E. coli inactivation was determined to be  ≈1.3   ×   10-9 mol mm-1.

Beam extraction and high stability operation of high current electron cyclotron resonance proton ion source.

PubMed

Roychowdhury, P; Mishra, L; Kewlani, H; Patil, D S; Mittal, K C

2014-03-01

A high current electron cyclotron resonance proton ion source is designed and developed for the low energy high intensity proton accelerator at Bhabha Atomic Research Centre. The plasma discharge in the ion source is stabilized by minimizing the reflected microwave power using four stub auto tuner and magnetic field. The optimization of extraction geometry is performed using PBGUNS code by varying the aperture, shape, accelerating gap, and the potential on the electrodes. While operating the source, it was found that the two layered microwave window (6 mm quartz plate and 2 mm boron nitride plate) was damaged (a fine hole was drilled) by the back-streaming electrons after continuous operation of the source for 3 h at beam current of 20-40 mA. The microwave window was then shifted from the line of sight of the back-streaming electrons and located after the water-cooled H-plane bend. In this configuration the stable operation of the high current ion source for several hours is achieved. The ion beam is extracted from the source by biasing plasma electrode, puller electrode, and ground electrode to +10 to +50 kV, -2 to -4 kV, and 0 kV, respectively. The total ion beam current of 30-40 mA is recorded on Faraday cup at 40 keV of beam energy at 600-1000 W of microwave power, 800-1000 G axial magnetic field and (1.2-3.9) × 10(-3) mbar of neutral hydrogen gas pressure in the plasma chamber. The dependence of beam current on extraction voltage, microwave power, and gas pressure is investigated in the range of operation of the ion source.

A review-application of physical vapor deposition (PVD) and related methods in the textile industry

NASA Astrophysics Data System (ADS)

Shahidi, Sheila; Moazzenchi, Bahareh; Ghoranneviss, Mahmood

2015-09-01

Physical vapor deposition (PVD) is a coating process in which thin films are deposited by the condensation of a vaporized form of the desired film material onto the substrate. The PVD process is carried out in a vacuum. PVD processes include different types, such as: cathode arc deposition, electron beam physical vapor deposition, evaporative deposition, sputtering, ion plating and enhanced sputtering. In the PVD method, the solid coating material is evaporated by heat or by bombardment with ions (sputtering). At the same time, a reactive gas is also introduced; it forms a compound with the metal vapor and is deposited on the substrate as a thin film with highly adherent coating. Such coatings are used in a wide range of applications such as aerospace, automotive, surgical, medical, dyes and molds for all manner of material processing, cutting tools, firearms, optics, thin films and textiles. The objective of this work is to give a comprehensive description and review of the science and technology related to physical vapor deposition with particular emphasis on their potential use in the textile industry. Physical vapor deposition has opened up new possibilities in the modification of textile materials and is an exciting prospect for usage in textile design and technical textiles. The basic principle of PVD is explained and the major applications, particularly sputter coatings in the modification and functionalization of textiles, are introduced in this research.

Ultrasonic Low-Friction Containment Plate for Thermal and Ultrasonic Stir Weld Processes

NASA Technical Reports Server (NTRS)

Graff, Karl; Short, Matt

2013-01-01

The thermal stir welding (TSW) process is finding applications in fabrication of space vehicles. In this process, workpieces to be joined by TSW are drawn, by heavy forces, between "containment plates," past the TSW tool that then causes joining of the separate plates. It is believed that the TSW process would be significantly improved by reducing the draw force, and that this could be achieved by reducing the friction forces between the workpieces and containment plates. Based on use of high-power ultrasonics in metal forming processes, where friction reduction in drawing dies has been achieved, it is believed that ultrasonic vibrations of the containment plates could achieve similar friction reduction in the TSW process. By applying ultrasonic vibrations to the containment plates in a longitudinal vibration mode, as well as by mounting and holding the containment plates in a specific manner such as to permit the plates to acoustically float, friction between the metal parts and the containment plates is greatly reduced, and so is the drawing force. The concept was to bring in the ultrasonics from the sides of the plates, permitting the ultrasonic hardware to be placed to the side, away from the equipment that contains the thermal stir tooling and that applies clamping forces to the plates. Tests demonstrated that one of the major objectives of applying ultrasonics to the thermal stir system, that of reducing draw force friction, should be achievable on a scaled-up system.

Earthquake clouds and physical mechanism of their formation.

NASA Astrophysics Data System (ADS)

Doda, L.; Pulinets, S.

2006-12-01

The Lithosphere-Atmosphere-Ionosphere (LAI) coupling model created recently permitted to explain some unknown phenomena observed around the time of strong earthquakes. One of them is formation of special shape clouds, usually presented as the thin linear structures. It was discovered that these clouds are associated with the active tectonic faults or with the tectonic plate borders. They repeat the fault shape but usually are turned in relation to the fault position. Their formation is explained by the anomalous vertical electric field generated in the vicinity of active tectonic structure due to air ionization produced by the radon increased emanation. The new formed ions through the hydration process do not recombine and growth with time due to increased water molecules attachment to the ion. Simultaneously they move up driven by the anomalous electric field and drift in the crossed ExB fields. At the higher altitudes the large ion clusters become the centers of condensation and the cloud formation. Examples for the recent major earthquakes (Sumatra 2004, Kashmir 2005, Java 2006) are presented. The size and the angle of the cloud rotation in relation to the fault position permit to estimate the magnitude of the impending earthquake.

Imaging of Endogenous Metabolites of Plant Leaves by Mass Spectrometry Based on Laser Activated Electron Tunneling.

PubMed

Huang, Lulu; Tang, Xuemei; Zhang, Wenyang; Jiang, Ruowei; Chen, Disong; Zhang, Juan; Zhong, Hongying

2016-04-07

A new mass spectrometric imaging approach based on laser activated electron tunneling (LAET) was described and applied to analysis of endogenous metabolites of plant leaves. LAET is an electron-directed soft ionization technique. Compressed thin films of semiconductor nanoparticles of bismuth cobalt zinc oxide were placed on the sample plate for proof-of-principle demonstration because they can not only absorb ultraviolet laser but also have high electron mobility. Upon laser irradiation, electrons are excited from valence bands to conduction bands. With appropriate kinetic energies, photoexcited electrons can tunnel away from the barrier and eventually be captured by charge deficient atoms present in neutral molecules. Resultant unpaired electron subsequently initiates specific chemical bond cleavage and generates ions that can be detected in negative ion mode of the mass spectrometer. LAET avoids the co-crystallization process of routinely used organic matrix materials with analyzes in MALDI (matrix assisted-laser desorption ionization) analysis. Thus uneven distribution of crystals with different sizes and shapes as well as background peaks in the low mass range resulting from matrix molecules is eliminated. Advantages of LAET imaging technique include not only improved spatial resolution but also photoelectron capture dissociation which produces predictable fragment ions.

Investigating MALDI MSI parameters (Part 1) - A systematic survey of the effects of repetition rates up to 20kHz in continuous raster mode.

PubMed

Steven, Rory T; Dexter, Alex; Bunch, Josephine

2016-07-15

Recent developments in laser performance, combined with the desire for increases in detected ion intensity and throughput, have led to the adoption of high repetition-rate diode-pumped solid-state (DPSS) lasers in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI). Previous studies have demonstrated a more complex relationship between detected ion intensity, stage raster speed and laser pulse repetition rate than the simple linear relationship between number of pulses and detected ion intensity that might be expected. Here we report, for the first time, the interrelated influence of varying laser energy, repetition rate and stage raster speed on detected ion intensity. Thin films of PC 34:1 lipid standard and murine brain tissue with CHCA are analysed by continuous stage raster MALDI MSI. Contrary to previous reports, the optimum laser repetition rate is found to be dependent on both laser energy and stage raster speed and is found to be as high as 20kHz under some conditions. The effects of different repetition rates and raster speeds are also found to vary for different ion species within MALDI MSI of tissue and so may be significant when either targeting specific molecules or seeking to minimize bias. A clear dependence on time between laser pulses is also observed indicating the underlying mechanisms may be related to on-plate hysteresis-exhibiting processes such as matrix chemical modification. Copyright © 2016 Elsevier Inc. All rights reserved.

Preparation of silica-supported porous sorbent for heavy metal ions removal in wastewater treatment by organic-inorganic hybridization combined with sucrose and polyethylene glycol imprinting.

PubMed

Li, Feng; Du, Ping; Chen, Wei; Zhang, Shusheng

2007-03-07

A new porous sorbent for wastewater treatment of metal ions was synthesized by covalent grafting of molecularly imprinted organic-inorganic hybrid on silica gel. With sucrose and polyethylene glycol 4000 (PEG 4000) being synergic imprinting molecules, covalent surface coating on silica gel was achieved by using polysaccharide-incorporated sol-gel process starting from the functional biopolymer, chitosan and an inorganic epoxy-precursor, gamma-glycidoxypropyltrimethoxysiloxane (GPTMS) at room temperature. The prepared porous sorbent was characterized by using simultaneous thermogravimetry and differential scanning calorimeter (TG/DSC), scanning electron microscopy (SEM), nitrogen adsorption porosimetry measurement and X-ray diffraction (XRD). Copper ion, Cu(2+), was chosen as the model metal ion to evaluate the effectiveness of the new biosorbent in wastewater treatment. The influence of epoxy-siloxane dose, buffer pH and co-existed ions on Cu(2+) adsorption was assessed through batch experiments. The imprinted composite sorbent offered a fast kinetics for the adsorption of Cu(2+). The uptake capacity of the sorbent imprinted by two pore-building components was higher than those imprinted with only a single component. The dynamic adsorption in column underwent a good elimination of Cu(2+) in treating electric plating wastewater. The prepared composite sorbent exhibited high reusability. Easy preparation of the described porous composite sorbent, absence of organic solvents, cost-effectiveness and high stability make this approach attractive in biosorption.

Bipolar plates for PEM fuel cells

NASA Astrophysics Data System (ADS)

Middelman, E.; Kout, W.; Vogelaar, B.; Lenssen, J.; de Waal, E.

The bipolar plates are in weight and volume the major part of the PEM fuel cell stack, and are also a significant contributor to the stack costs. The bipolar plate is therefore a key component if power density has to increase and costs must come down. Three cell plate technologies are expected to reach targeted cost price levels, all having specific advantages and drawbacks. NedStack has developed a conductive composite materials and a production process for fuel cell plates (bipolar and mono-polar). The material has a high electric and thermal conductivity, and can be processed into bipolar plates by a proprietary molding process. Process cycle time has been reduced to less than 10 s, making the material and process suitable for economical mass production. Other development work to increase material efficiency resulted in thin bipolar plates with integrated cooling channels, and integrated seals, and in two-component bipolar plates. Total thickness of the bipolar plates is now less than 3 mm, and will be reduced to 2 mm in the near future. With these thin integrated plates it is possible to increase power density up to 2 kW/l and 2 kW/kg, while at the same time reducing cost by integrating other functions and less material use.

Alkali ionization detector

DOEpatents

Hrizo, John; Bauerle, James E.; Witkowski, Robert E.

1982-01-01

A calibration filament containing a sodium-bearing compound is included in combination with the sensing filament and ion collector plate of a sodium ionization detector to permit periodic generation of sodium atoms for the in-situ calibration of the detector.

Matrix-free mass spectrometric imaging using laser desorption ionisation Fourier transform ion cyclotron resonance mass spectrometry.

PubMed

Goodwin, Richard J A; Pitt, Andrew R; Harrison, David; Weidt, Stefan K; Langridge-Smith, Pat R R; Barrett, Michael P; Logan Mackay, C

2011-04-15

Mass spectrometry imaging (MSI) is a powerful tool in metabolomics and proteomics for the spatial localization and identification of pharmaceuticals, metabolites, lipids, peptides and proteins in biological tissues. However, sample preparation remains a crucial variable in obtaining the most accurate distributions. Common washing steps used to remove salts, and solvent-based matrix application, allow analyte spreading to occur. Solvent-free matrix applications can reduce this risk, but increase the possibility of ionisation bias due to matrix adhesion to tissue sections. We report here the use of matrix-free MSI using laser desorption ionisation performed on a 12 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. We used unprocessed tissue with no post-processing following thaw-mounting on matrix-assisted laser desorption ionisation (MALDI) indium-tin oxide (ITO) target plates. The identification and distribution of a range of phospholipids in mouse brain and kidney sections are presented and compared with previously published MALDI time-of-flight (TOF) MSI distributions. Copyright © 2011 John Wiley & Sons, Ltd.

Application of a chromatography model with linear gradient elution experimental data to the rapid scale-up in ion-exchange process chromatography of proteins.

PubMed

Ishihara, Takashi; Kadoya, Toshihiko; Yamamoto, Shuichi

2007-08-24

We applied the model described in our previous paper to the rapid scale-up in the ion exchange chromatography of proteins, in which linear flow velocity, column length and gradient slope were changed. We carried out linear gradient elution experiments, and obtained data for the peak salt concentration and peak width. From these data, the plate height (HETP) was calculated as a function of the mobile phase velocity and iso-resolution curve (the separation time and elution volume relationship for the same resolution) was calculated. The scale-up chromatography conditions were determined by the iso-resolution curve. The scale-up of the linear gradient elution from 5 to 100mL and 2.5L column sizes was performed both by the separation of beta-lactoglobulin A and beta-lactoglobulin B with anion-exchange chromatography and by the purification of a recombinant protein with cation-exchange chromatography. Resolution, recovery and purity were examined in order to verify the proposed method.

Specific variations of air temperature and relative humidity around the time of Michoacan earthquake M8.1 Sept. 19, 1985 as a possible indicator of interaction between tectonic plates

NASA Astrophysics Data System (ADS)

Pulinets, S. A.; Dunajecka, M. A.

2007-02-01

The recent development of the Lithosphere-Atmosphere-Ionosphere (LAI) coupling model and experimental data of remote sensing satellites on thermal anomalies before major strong earthquakes have demonstrated that radon emanations in the area of earthquake preparation can produce variations of the air temperature and relative humidity. Specific repeating pattern of humidity and air temperature variations was revealed as a result of analysis of the meteorological data for several tens of strong earthquakes all over the world. The main physical process responsible for the observed variations is the latent heat release due to water vapor condensation on ions produced as a result of air ionization by energetic α-particles emitted by 222Rn. The high effectiveness of this process was proved by the laboratory and field experiments; hence the specific variations of air humidity and temperature can be used as indicator of radon variations before earthquakes. We analyzed the historical meteorological data all over the Mexico around the time of one of the most destructive earthquakes (Michoacan earthquake M8.1) that affected the Mexico City on September 19, 1985. Several distinct zones of specific variations of the air temperature and relative humidity were revealed that may indicate the different character of radon variations in different parts of Mexico before the Michoacan earthquake. The most interesting result on the specific variations of atmosphere parameters was obtained at Baja California region close to the border of Cocos and Rivera tectonic plates. This result demonstrates the possibility of the increased radon variations not only in the vicinity of the earthquake source but also at the border of interacting tectonic plates. Recent results on Thermal InfraRed (TIR) anomalies registered by Meteosat 5 before the Gujarat earthquake M7.9 on 26 of January 2001 supports the idea on the possibility of thermal effects at the border of interacting tectonic plates.

Ionization chamber dosimeter

DOEpatents

Renner, Tim R.; Nyman, Mark A.; Stradtner, Ronald

1991-01-01

A method for fabricating an ion chamber dosimeter collecting array of the type utilizing plural discrete elements formed on a uniform collecting surface which includes forming a thin insulating layer over an aperture in a frame having surfaces, forming a predetermined pattern of through holes in the layer, plating both surfaces of the layer and simultaneously tilting and rotating the frame for uniform plate-through of the holes between surfaces. Aligned masking and patterned etching of the surfaces provides interconnects between the through holes and copper leads provided to external circuitry.

High precision electric gate for time-of-flight ion mass spectrometers

NASA Technical Reports Server (NTRS)

Sittler, Edward C. (Inventor)

2011-01-01

A time-of-flight mass spectrometer having a chamber with electrodes to generate an electric field in the chamber and electric gating for allowing ions with a predetermined mass and velocity into the electric field. The design uses a row of very thin parallel aligned wires that are pulsed in sequence so the ion can pass through the gap of two parallel plates, which are biased to prevent passage of the ion. This design by itself can provide a high mass resolution capability and a very precise start pulse for an ion mass spectrometer. Furthermore, the ion will only pass through the chamber if it is within a wire diameter of the first wire when it is pulsed and has the right speed so it is near all other wires when they are pulsed.

Multicharged iron ions produced by using induction heating vapor source.

PubMed

Kato, Yushi; Kubo, Takashi; Muramatsu, Masayuki; Tanaka, Kiyokatsu; Kitagawa, Atsushi; Yoshida, Yoshikazu; Asaji, Toyohisa; Sato, Fuminobu; Iida, Toshiyuki

2008-02-01

Multiply charged Fe ions are produced from solid pure material in an electron cyclotron resonance (ECR) ion source. We develop an evaporator by using induction heating with an induction coil which is made of bare molybdenum wire partially covered by ceramic beads in vacuum and surrounding and heating directly the pure Fe rod. Heated material has no contact with insulators, so that outgas is minimized. The evaporator is installed around the mirror end plate outside of the ECR plasma with its hole grazing the ECR zone. Helium or argon gas is usually chosen for supporting gas. The multicharged Fe ions up to Fe(13+) are extracted from the opposite side of mirror and against the evaporator, and then multicharged Fe ion beam is formed. We compare production of multicharged iron ions by using this new source with our previous methods.

Method and apparatus for capacitive deionization, electrochemical purification, and regeneration of electrodes

DOEpatents

Farmer, Joseph

1995-01-01

An electrochemical cell for capacitive deionization and electrochemical purification and regeneration of electrodes includes two oppositely disposed, spaced-apart end plates, one at each end of the cell. Two generally identical single-sided end electrodes, are arranged one at each end of the cell, adjacent to the end plates. An insulator layer is interposed between each end plate and the adjacent end electrode. Each end electrode includes a single sheet of conductive material having a high specific surface area and sorption capacity. In the preferred embodiment, the sheet of conductive material is formed of carbon aerogel composite. The cell further includes a plurality of generally identical double-sided intermediate electrodes that are equidistally separated from each other, between the two end electrodes. As the electrolyte enters the cell, it flows through a continuous open serpentine channel defined by the electrodes, substantially parallel to the surfaces of the electrodes. By polarizing the cell, ions are removed from the electrolyte and are held in the electric double layers formed at the carbon aerogel surfaces of the electrodes. As the cell is saturated with the removed ions, the cell is regenerated electrically, thus significantly minimizing secondary wastes.

Method and apparatus for capacitive deionization, electrochemical purification, and regeneration of electrodes

DOEpatents

Farmer, J.

1995-06-20

An electrochemical cell for capacitive deionization and electrochemical purification and regeneration of electrodes includes two oppositely disposed, spaced-apart end plates, one at each end of the cell. Two generally identical single-sided end electrodes, are arranged one at each end of the cell, adjacent to the end plates. An insulator layer is interposed between each end plate and the adjacent end electrode. Each end electrode includes a single sheet of conductive material having a high specific surface area and sorption capacity. In the preferred embodiment, the sheet of conductive material is formed of carbon aerogel composite. The cell further includes a plurality of generally identical double-sided intermediate electrodes that are equidistantly separated from each other, between the two end electrodes. As the electrolyte enters the cell, it flows through a continuous open serpentine channel defined by the electrodes, substantially parallel to the surfaces of the electrodes. By polarizing the cell, ions are removed from the electrolyte and are held in the electric double layers formed at the carbon aerogel surfaces of the electrodes. As the cell is saturated with the removed ions, the cell is regenerated electrically, thus significantly minimizing secondary wastes. 17 figs.

Thin-layer chromatography and mass spectrometry coupled using proximal probe thermal desorption with electrospray or atmospheric pressure chemical ionization.

PubMed

Ovchinnikova, Olga S; Van Berkel, Gary J

2010-06-30

An atmospheric pressure proximal probe thermal desorption sampling method coupled with secondary ionization by electrospray or atmospheric pressure chemical ionization was demonstrated for the mass spectrometric analysis of a diverse set of compounds (dyestuffs, pharmaceuticals, explosives and pesticides) separated on various high-performance thin-layer chromatography plates. Line scans along or through development lanes on the plates were carried out by moving the plate relative to a stationary heated probe positioned close to or just touching the stationary phase surface. Vapors of the compounds thermally desorbed from the surface were drawn into the ionization region of a combined electrospray ionization/atmospheric pressure chemical ionization source where they merged with reagent ions and/or charged droplets from a corona discharge or an electrospray emitter and were ionized. The ionized components were then drawn through the atmospheric pressure sampling orifice into the vacuum region of a triple quadrupole mass spectrometer and detected using full scan, single ion monitoring, or selected reaction monitoring mode. Studies of variable parameters and performance metrics including the proximal probe temperature, gas flow rate into the ionization region, surface scan speed, read-out resolution, detection limits, and surface type are discussed.

Characterization of a novel two dimensional diode array the "magic plate" as a radiation detector for radiation therapy treatment.

PubMed

Wong, J H D; Fuduli, I; Carolan, M; Petasecca, M; Lerch, M L F; Perevertaylo, V L; Metcalfe, P; Rosenfeld, A B

2012-05-01

Intensity modulated radiation therapy (IMRT) utilizes the technology of multileaf collimators to deliver highly modulated and complex radiation treatment. Dosimetric verification of the IMRT treatment requires the verification of the delivered dose distribution. Two dimensional ion chamber or diode arrays are gaining popularity as a dosimeter of choice due to their real time feedback compared to film dosimetry. This paper describes the characterization of a novel 2D diode array, which has been named the "magic plate" (MP). It was designed to function as a 2D transmission detector as well as a planar detector for dose distribution measurements in a solid water phantom for the dosimetric verification of IMRT treatment delivery. The prototype MP is an 11 × 11 detector array based on thin (50 μm) epitaxial diode technology mounted on a 0.6 mm thick Kapton substrate using a proprietary "drop-in" technology developed by the Centre for Medical Radiation Physics, University of Wollongong. A full characterization of the detector was performed, including radiation damage study, dose per pulse effect, percent depth dose comparison with CC13 ion chamber and build up characteristics with a parallel plane ion chamber measurements, dose linearity, energy response and angular response. Postirradiated magic plate diodes showed a reproducibility of 2.1%. The MP dose per pulse response decreased at higher dose rates while at lower dose rates the MP appears to be dose rate independent. The depth dose measurement of the MP agrees with ion chamber depth dose measurements to within 0.7% while dose linearity was excellent. MP showed angular response dependency due to the anisotropy of the silicon diode with the maximum variation in angular response of 10.8% at gantry angle 180°. Angular dependence was within 3.5% for the gantry angles ± 75°. The field size dependence of the MP at isocenter agrees with ion chamber measurement to within 1.1%. In the beam perturbation study, the surface dose increased by 12.1% for a 30 × 30 cm(2) field size at the source to detector distance (SDD) of 80 cm whilst the transmission for the MP was 99%. The radiation response of the magic plate was successfully characterized. The array of epitaxial silicon based detectors with "drop-in" packaging showed properties suitable to be used as a simplified multipurpose and nonperturbing 2D radiation detector for radiation therapy dosimetric verification.

Electrical Aspects of Impinging Flames

NASA Astrophysics Data System (ADS)

Chien, Yu-Chien

This dissertation examines the use of electric fields as one mechanism for controlling combustion as flames are partially extinguished when impinging on nearby surfaces. Electrical aspects of flames, specifically, the production of chemi-ions in hydrocarbon flames and the use of convective flows driven by these ions, have been investigated in a wide range of applications in prior work but despite this fairly comprehensive effort to study electrical aspects of combustion, relatively little research has focused on electrical phenomena near flame extinguishment, nor for flames near impingement surfaces. Electrical impinging flames have complex properties under global influences of ion-driven winds and flow field disturbances from the impingement surface. Challenges of measurements when an electric field is applied in the system have limited an understanding of changes to the flame behavior and species concentrations caused by the field. This research initially characterizes the ability of high voltage power supplies to respond on sufficiently short time scales to permit real time electrical flame actuation. The study then characterizes the influence of an electric field on the impinging flame shape, ion current and flow field of the thermal plume associated with the flame. The more significant further examinations can be separated into two parts: 1) the potential for using electric fields to control the release of carbon monoxide (CO) from surface-impinging flames, and 2) an investigation of controlling electrically the heat transfer to a plate on which the flame impinges. Carbon monoxide (CO) results from the incomplete oxidation of hydrocarbon fuels and, while CO can be desirable in some syngas processes, it is usually a dangerous emission from forest fires, gas heaters, gas stoves, or furnaces where insufficient oxygen in the core reaction does not fully oxidize the fuel to carbon dioxide and water. Determining how carbon monoxide is released and how heat transfer from the flame to the plate can be controlled using the electric field are the two main goals of this research. Multiple diagnostic techniques are employed such as OH chemiluminescence to identify the reaction zone, OH PLIF to characterize the location of this radical species, CO released from the flame, IR imaging and OH PLIF thermometry to understand the surface and gas temperature distribution, respectively. The principal finding is that carbon monoxide release from an impinging diffusion flame results from the escape of carbon monoxide created on the fuel side of the flame along the boundary layer near the surface where it avoids oxidation by OH, which sits to the air side of the reaction sheet interface. In addition, the plate proximity to the flame has a stronger influence on the emission of toxic carbon monoxide than does the electric field strength. There is, however, a narrow region of burner to surface distance where the electric field is most effective. The results also show that heat transfer can be spatially concentrated effectively using an electric field driven ion wind, particularly at some burner to surface distances.

Biocompatibility of hydroxyapatite coatings deposited by pulse electrodeposition technique on the Nitinol superelastic alloy.

PubMed

Marashi-Najafi, F; Khalil-Allafi, J; Etminanfar, M R

2017-07-01

The present study deals with pulse electrochemical deposition of HA on NiTi alloy and in vitro evaluation of coatings. At first step, a thermo-chemical surface modification process was applied to control the Ni release of the alloy. The electrochemical deposition of CaP coatings was examined at both dilute and concentrated solutions. The morphology and the composition of coatings were studied using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Plate like and needle like morphologies were formed for dilute and concentrated solution respectively and HA phase was formed by increasing the pulse current density for both electrolyte. The thickness of the samples was measured using cross sectioning technique. Fibroblast cell culture test on the coated samples revealed that the HA coating obtained by dilute solution shows the best biocompatibility. Also, MTT assay showed the highest cell density and cell proliferation after 5days for the HA coating of dilute solution. The contact angle of samples was measured and the coated samples showed a hydrophilic surface. Soaking the sample in SBF revealed that the crystallization rate of calcium-phosphate compounds is higher on the plate like HA coating as compared to the needle like morphology. The P release of the HA coated samples was measured in a physiological saline solution and the results show that the ions releasing in the plate like coating are less than the needle like coating. It seems that the stability of the plate like coating in biological environments is responsible for the better biocompatibility of the coating. Copyright © 2017 Elsevier B.V. All rights reserved.

The Characteristics of an Antibacterial TiAgN Thin Film Coated by Physical Vapor Deposition Technique.

PubMed

Kang, Byeong-Mo; Jeong, Woon-Jo; Park, Gye-Choon; Yoon, Dong-Joo; Ahn, Ho-Geun; Lim, Yeong-Seog

2015-08-01

In this work, we found the characteristics of an antibacterial TiAgN thin film coated on the pure titanium specimen via the physical vapor deposition process (PVD). TiAgN thin films were coated using TiAg alloy targets by arc ion plating method. Changing the process parameters, the surface analysis of TiAgN thin film was observed by FE-SEM and the force of adhesion was measured with Scratch Tester. The proliferation of human gingival fibroblast (HGF) cells was examined by XTT test assay and the antibacterial properties were investigated by culturing Streptococus Mutans (KCTC 3065) using paper disk techniques. At the result of experiment, cytotoxic effects were not found and the antibacterial effects against Streptococus Mutans were appeared over 5 wt% TiAgN specimens.

Characterization of thermo- and detergent stable antigenic glycosylated cysteine protease of Euphorbia nivulia Buch.-Ham. and evaluation of its ecofriendly applications.

PubMed

Badgujar, Shamkant B; Mahajan, Raghunath T

2013-01-01

An antigenic glycosylated cysteine protease has been purified from the latex of Euphorbia nivulia Buch.-Ham. It exhibits remarkable protease activity in the presence of metal ions, oxidizing agents, organic solvents, and detergents. This enzyme showed potential role in leather processing industry due to its dehairing activity for animal hide without hydrolyzing fibrous proteins, producing, by this way, a better quality product. The enzyme can also be used for silver recovering from X-ray plates. In addition, the stability (temperature and surfactants) and hydrolysis of blood stain data also revealed its application in detergent industries. Agriculturally, this protease finds application in biocontrol process against the infectious management of root knot nematode, Meloidogyne incognita. Biologically, it shows noticeable wound healing, haemostatic and antibacterial activity.

Characterization of Thermo- and Detergent Stable Antigenic Glycosylated Cysteine Protease of Euphorbia nivulia Buch.-Ham. and Evaluation of Its Ecofriendly Applications

PubMed Central

Badgujar, Shamkant B.; Mahajan, Raghunath T.

2013-01-01

An antigenic glycosylated cysteine protease has been purified from the latex of Euphorbia nivulia Buch.-Ham. It exhibits remarkable protease activity in the presence of metal ions, oxidizing agents, organic solvents, and detergents. This enzyme showed potential role in leather processing industry due to its dehairing activity for animal hide without hydrolyzing fibrous proteins, producing, by this way, a better quality product. The enzyme can also be used for silver recovering from X-ray plates. In addition, the stability (temperature and surfactants) and hydrolysis of blood stain data also revealed its application in detergent industries. Agriculturally, this protease finds application in biocontrol process against the infectious management of root knot nematode, Meloidogyne incognita. Biologically, it shows noticeable wound healing, haemostatic and antibacterial activity. PMID:24348183

Influence of Deposition Conditions on Fatigue Properties of Martensitic Stainless Steel with Tin Film Coated by Arc Ion Plating Method

NASA Astrophysics Data System (ADS)

Fukui, Satoshi; Yonekura, Daisuke; Murakami, Ri-Ichi

The surface properties like roughness etc. strongly influence the fatigue strength of high-tensile steel. To investigate the effect of surface condition and TiN coating on the fatigue strength of high-strength steel, four-point bending fatigue tests were carried out for martensitic stainless steel with TiN film coated using arc ion plating (AIP) method. This study, using samples that had been polished under several size of grind particle, examines the influence of pre-coating treatment on fatigue properties. A 2-µm-thick TiN film was deposited onto the substrate under three kinds of polishing condition. The difference of the hardness originated in the residual stress or thin deformation layer where the difference of the size of grinding particle of the surface polishing. And it leads the transformation of the interface of the substrate and the TiN film and improves fatigue limit.

Wide range radioactive gas concentration detector

DOEpatents

Anderson, David F.

1984-01-01

A wide range radioactive gas concentration detector and monitor which is capable of measuring radioactive gas concentrations over a range of eight orders of magnitude. The device of the present invention is designed to have an ionization chamber which is sufficiently small to give a fast response time for measuring radioactive gases but sufficiently large to provide accurate readings at low concentration levels. Closely spaced parallel plate grids provide a uniform electric field in the active region to improve the accuracy of measurements and reduce ion migration time so as to virtually eliminate errors due to ion recombination. The parallel plate grids are fabricated with a minimal surface area to reduce the effects of contamination resulting from absorption of contaminating materials on the surface of the grids. Additionally, the ionization chamber wall is spaced a sufficient distance from the active region of the ionization chamber to minimize contamination effects.

In vitro assessments on bacterial adhesion and corrosion performance of TiN coating on Ti6Al4V titanium alloy synthesized by multi-arc ion plating

NASA Astrophysics Data System (ADS)

Lin, Naiming; Huang, Xiaobo; Zhang, Xiangyu; Fan, Ailan; Qin, Lin; Tang, Bin

2012-07-01

TiN coating was synthesized on Ti6Al4V titanium alloy surface by multi-arc ion plating (MIP) technique. Surface morphology, cross sectional microstructure, elemental distributions and phase compositions of the obtained coating were analyzed by means of scanning electron microscope (SEM), optical microscope (OM), glow discharge optical emission spectroscope (GDOES) and X-ray diffraction (XRD). Bacterial adhesion and corrosion performance of Ti6Al4V and the TiN coating were assessed via in vitro bacterial adhesion tests and corrosion experiments, respectively. The results indicated that continuous and compact coating which was built up by pure TiN with a typical columnar crystal structure has reached a thickness of 1.5 μm. This TiN coating could significantly reduce the bacterial adhesion and enhance the corrosion resistance of Ti6Al4V substrate.

Gamma-ray detection efficiency of the microchannel plate installed as an ion detector in the low energy particle instrument onboard the GEOTAIL satellite.

PubMed

Tanaka, Y T; Yoshikawa, I; Yoshioka, K; Terasawa, T; Saito, Y; Mukai, T

2007-03-01

A microchannel plate (MCP) assembly has been used as an ion detector in the low energy particle (LEP) instrument onboard the magnetospheric satellite GEOTAIL. Recently the MCP assembly has detected gamma rays emitted from an astronomical object and has been shown to provide unique information of gamma rays if they are intense enough. However, the detection efficiency for gamma rays was not measured before launch, and therefore we could not analyze the LEP data quantitatively. In this article, we report the gamma-ray detection efficiency of the MCP assembly. The measured efficiencies are 1.29%+/-0.71% and 0.21%+/-0.14% for normal incidence 60 and 662 keV gamma rays, respectively. The incident angle dependence is also presented. Our calibration is crucial to study high energy astrophysical phenomena by using the LEP.

In Situ Enrichment of Phosphopeptides on MALDI Plates Functionalized by Reactive Landing of Zirconium(IV)–n-Propoxide Ions

PubMed Central

Blacken, Grady R.; Volný, Michael; Vaisar, Tomáš; Sadílek, Martin; Tureček, František

2008-01-01

We report substantial in situ enrichment of phosphopeptides in peptide mixtures using zirconium oxide coated plates for detection by MALDI-TOF mass spectrometry. The novel feature of this approach rests on the specific preparation of zirconium oxide coatings using reactive landing on stainless steel support of gas-phase positive ions produced by electrospray of zirconium(IV)–n-propoxide solutions in 1-propanol. Reactive landing was found to produce durable functionalized surfaces for selective phosphopeptide capture and desorption–ionization by MALDI. Enrichment factors on the order of 20–90 were achieved for several monophosphorylated peptides relative to abundant nonphosphorylated peptides in tryptic digests. We demonstrate the ability of the zirconium oxide functionalized MALDI surfaces to facilitate detection of enriched phosphopeptides in mid-femtomole amounts of α-casein digests per MALDI spot. PMID:17569507

Parallel-plate wet denuder coupled ion chromatograph for near-real-time detection of trace acidic gases in clean room air.

PubMed

Takeuchi, Masaki; Tsunoda, Hiromichi; Tanaka, Hideji; Shiramizu, Yoshimi

2011-01-01

This paper describes the performance of our automated acidic (CH(3)COOH, HCOOH, HCl, HNO(2), SO(2), and HNO(3)) gases monitor utilizing a parallel-plate wet denuder (PPWD). The PPWD quantitatively collects gaseous contaminants at a high sample flow rate (∼8 dm(3) min(-1)) compared to the conventional methods used in a clean room. Rapid response to any variability in the sample concentration enables near-real-time monitoring. In the developed monitor, the analyte collected with the PPWD is pumped into one of two preconcentration columns for 15 min, and determined by means of ion chromatography. While one preconcentration column is used for chromatographic separation, the other is used for loading the sample solution. The system allows continuous monitoring of the common acidic gases in an advanced semiconductor manufacturing clean room. 2011 © The Japan Society for Analytical Chemistry

Friction and hardness of gold films deposited by ion plating and evaporation

NASA Technical Reports Server (NTRS)

Miyoshi, K.; Spalvins, T.; Buckley, D. H.

1983-01-01

Sliding friction experiments were conducted with ion-plated and vapor-deposited gold films on various substrates in contact with a 0.025-mm-radius spherical silicon carbide rider in mineral oil. Hardness measurements were also made to examine the hardness depth profile of the coated gold on the substrate. The results indicate that the hardness is influenced by the depth of the gold coating from the surface. The hardness increases with an increase in the depth. The hardness is also related to the composition gradient in the graded interface between the gold coating and the substrate. The graded interface exhibited the highest hardness resulting from an alloy hardening effect. The coefficient of friction is inversely related to the hardness, namely, the load carrying capacity of the surface. The greater the hardness that the metal surface possesses, the lower is the coefficient of friction. The graded interface exhibited the lowest coefficient of friction.

Optimal design of zero-water discharge rinsing systems.

PubMed

Thöming, Jorg

2002-03-01

This paper is about zero liquid discharge in processes that use water for rinsing. Emphasis was given to those systems that contaminate process water with valuable process liquor and compounds. The approach involved the synthesis of optimal rinsing and recycling networks (RRN) that had a priori excluded water discharge. The total annualized costs of the RRN were minimized by the use of a mixed-integer nonlinear program (MINLP). This MINLP was based on a hyperstructure of the RRN and contained eight counterflow rinsing stages and three regenerator units: electrodialysis, reverse osmosis, and ion exchange columns. A "large-scale nickel plating process" case study showed that by means of zero-water discharge and optimized rinsing the total waste could be reduced by 90.4% at a revenue of $448,000/yr. Furthermore, with the optimized RRN, the rinsing performance can be improved significantly at a low-cost increase. In all the cases, the amount of valuable compounds reclaimed was above 99%.

Design and development of a chopping and deflecting system for the high current injector at IUAC

NASA Astrophysics Data System (ADS)

Kedia, Sanjay Kumar; Mehta, R.

2018-05-01

The Low Energy Beam Transport (LEBT) section of the High Current Injector (HCI) incorporates a Chopping cum Deflecting System (CDS). The CDS comprises of a deflecting system and a pair of slits that will remove dark current and produce time bunched beam of 60 ns at different repetition rates of 4, 2, 1, 0.5, 0.25 and 0.125 MHz. The distinguishing feature of the design is the use of a multi-plate deflecting structure with low capacitance to optimize the electric field, which in turn results in higher efficiency in terms of achievable ion current. To maximize the effective electric field and its uniformity, the gap between the deflecting plates has been varied and a semi-circular contour has been incorporated on the deflecting plates. Due to this the electric field variation is less than ±0.5% within the plate length. The length of deflecting plates was chosen to maximize the transmission efficiency. Since the velocity of the charged particles in the LEBT section is constant, therefore the separation between two successive sets of deflecting plates has been kept constant to match the ions transient time within the gap which is nearly 32 ns. A square pulse has been chosen, instead of a sinusoidal one, to increase the transmission efficiency and to decrease the tailing effect. The loaded capacitance of the structure was kept <10 pF to achieve fast rise/fall time of the applied voltage signal. A Python code has been developed to verify the various design parameters. The simulation also shows that one can get an efficient deflection of undesired particles resulting in >90% transmission efficiency with in the bunch length. Various simulation codes like Solid Works, TRACE 3D, CST MWS and homebrew Python codes were used to validate the design.

Application research of CO2 laser cutting natural stone plates

NASA Astrophysics Data System (ADS)

Ma, Lixiu; Song, Jijiang

2009-08-01

Now, the processing of natural stone plates is the high performance sawing machine primarily,many researchers deeply studied the processing characters in the sawing process and the strength characters during the processing. In order to realize the profiled-processing and pattern- carving of the natural stone, It lays a solid foundation for the laser cutting and the pattern-carving technology of natural stone plate. The working principle, type and characteristics of laser cutting are briefly described. The paper selects 6 kinds stone plates of natural taken as experimental sample,the experimental sample was China Shanxi Black, Old Spain Golden Yellow, New Spain Golden Yellow, Jazz White, Maple Leaf Red, Cream White respectively. Use high power CO2 laser cutting system,the stone plates cutting experiment of 6 kinds different hardness, the best working speed are obtained,The experimental results indicate that: The laser cutting speed has no correlation with the ingredient content of stone plate.

Atomic layer deposition frequency-multiplied Fresnel zone plates for hard x-rays focusing

DOE PAGES

Moldovan, Nicolaie; Divan, Ralu; Zeng, Hongjun; ...

2017-12-01

The design and fabrication of Fresnel zone plates for hard x-ray focusing up to 25 keV photon energies with better than 50 nm imaging half-pitch resolution is reported as performed by forming an ultrananocrystalline diamond (UNCD) scaffold, subsequently coating it with atomic layer deposition (ALD) with an absorber/phase shifting material, followed by back side etching of Si to form a diamond membrane device. The scaffold is formed by chemical vapor-deposited UNCD, electron beam lithography, and deep-reactive ion etching of diamond to desired specifications. The benefits of using diamond are as follows: improved mechanical robustness to prevent collapse of high-aspect-ratio ringmore » structures, a known high-aspect-ratio etch method, excellent radiation hardness, extremely low x-ray absorption, and significantly improved thermal/dimensional stability as compared to alternative materials. Central to the technology is the high-resolution patterning of diamond membranes at wafer scale, which was pushed to 60 nm lines and spaces etched 2.2-mu m-deep, to an aspect ratio of 36:1. The absorber growth was achieved by ALD of Ir, Pt, or W, while wafer-level processing allowed to obtain up to 121 device chips per 4 in. wafer with yields better than 60%. X-ray tests with such zone plates allowed resolving 50 nm lines and spaces, at the limit of the available resolution test structures.« less

Characterization and Performance of a High-Current-Density Ion Implanter with Magnetized Hollow-Cathode Plasma Source

NASA Astrophysics Data System (ADS)

Falkenstein, Zoran; Rej, Donald; Gavrilov, Nikolai

1998-10-01

In a collaboration between the Institute of Electrophysics (IEP) and the Los Alamos National Laboratory (LANL), the IEP has developed an industrial scalable, high-power, large-area ion source for the surface modification of materials. The plasma source of the ion beam source can be described as a pulsed glow discharge with a cold, hollow-cathode in a weak magnetic field. Extraction and focusing of positive ions by an acceleration and ion-optical plate system renders the generation of a homogeneous, large-area ion beam with an averaged total ion current of up to 50 mA at acceleration voltages of up to 50 kV. The principle set-up of the ion beam source as well as some electrical characteristics (gas discharge current and the extracted ion beam current) are presented for a lab-scale prototype. Measurements of the radial ion current density profiles within the ion beam for various discharge parameters, as well as results on surface modification by ion implantation of nitrogen into aluminum and chromium are presented. Finally, a comparison of the applied ion dose with the retained ion doses is given.

Radiological characterization of the pressure vessel internals of the BNL High Flux Beam Reactor.

PubMed

Holden, Norman E; Reciniello, Richard N; Hu, Jih-Perng

2004-08-01

In preparation for the eventual decommissioning of the High Flux Beam Reactor after the permanent removal of its fuel elements from the Brookhaven National Laboratory, measurements and calculations of the decay gamma-ray dose-rate were performed in the reactor pressure vessel and on vessel internal structures such as the upper and lower thermal shields, the Transition Plate, and the Control Rod blades. Measurements of gamma-ray dose rates were made using Red Perspex polymethyl methacrylate high-dose film, a Radcal "peanut" ion chamber, and Eberline's RO-7 high-range ion chamber. As a comparison, the Monte Carlo MCNP code and MicroShield code were used to model the gamma-ray transport and dose buildup. The gamma-ray dose rate at 8 cm above the center of the Transition Plate was measured to be 160 Gy h (using an RO-7) and 88 Gy h at 8 cm above and about 5 cm lateral to the Transition Plate (using Red Perspex film). This compares with a calculated dose rate of 172 Gy h using Micro-Shield. The gamma-ray dose rate was 16.2 Gy h measured at 76 cm from the reactor core (using the "peanut" ion chamber) and 16.3 Gy h at 87 cm from the core (using Red Perspex film). The similarity of dose rates measured with different instruments indicates that using different methods and instruments is acceptable if the measurement (and calculation) parameters are well defined. Different measurement techniques may be necessary due to constraints such as size restrictions.

Development of a plug-type IMS-MS instrument and its applications in resolving problems existing in in-situ detection of illicit drugs and explosives by IMS.

PubMed

Du, Zhenxia; Sun, Tangqiang; Zhao, Jianan; Wang, Di; Zhang, Zhongxia; Yu, Wenlian

2018-07-01

Ion mobility spectrometry (IMS) which acts as a rapid analysis technique is widely used in the field detection of illicit drugs and explosives. Due to limited separation abilities of the pint-sized IMS challenges and problems still exist regarding high false positive and false negative responses due to the interference of the matrix. In addition, the gas-phase ion chemistry and special phenomena in the IMS spectra, such one substance showing two peaks, were not identified unambiguously. In order to explain or resolve these questions, in this paper, an ion mobility spectrometry was coupled to a mass spectrometry (IMS-MS). A commercial IMS is embedded in a custom-built ion chamber shell was attached to the mass spectrometer. The faraday plate of IMS was fabricated with a hole for the ions to passing through to the mass spectrometer. The ion transmission efficiency of IMS-MS was optimized by optimizing the various parameters, especially the distance between the faraday plate and the cone of mass spectrum. This design keeps the integrity of the two original instruments and the mass spectrometry still works with multimode ionization source (i.e., IMS-MS, ESI-MS, APCI-MS modes). The illicit drugs and explosive samples were analyzed by the IMS-MS with 63 Ni source. The results showed that the IMS-MS is of high sensitivity. The ionization mechanism of the illicit drug and explosive samples with 63 Ni source were systematically studied. In addition, the interferent which interfered the detection of cocaine was identified as dibutyl phthalate (DBP) by this platform. The reason why the acetone solution of amphetamine showed two peaks was explained. Copyright © 2018 Elsevier B.V. All rights reserved.

Cavity-Enhanced Spectroscopy of Molecular Ions in the Mid-Infrared with Up-Conversion Detection and Brewster-Plate Spoilers

NASA Astrophysics Data System (ADS)

Markus, Charles R.; McCollum, Jefferson E.; Hodges, James Neil; Perry, Adam J.; McCall, Benjamin J.

2017-06-01

Molecular ions are challenging to study with conventional spectroscopic methods. Laboratory discharges produce ions in trace quantities which can be obscured by the abundant neutral molecules present. The technique Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy (NICE-OHVMS) overcomes these challenges by combining the ion-neutral discrimination of velocity modulation spectroscopy with the sensitivity of Noise-Immune Cavity-Enhanced Optical Heterodyne Molecular Spectroscopy (NICE-OHMS), and has been able to determine transition frequencies of molecular ions in the mid-infrared (mid-IR) with sub-MHz uncertainties when calibrated with an optical frequency comb. However, the extent of these studies was limited by the presence of fringes due to parasitic etalons and the speed and noise characteristics of mid-IR detectors. Recently, we have overcome these limitations by implementing up-conversion detection and dithered optics. We performed up-conversion using periodically poled lithium niobate to convert light from the mid-IR to the visible to be within the coverage of sensitive and fast silicon detectors while maintaining our heterodyne and velocity modulation signals. The parasitic etalons were removed by rapidly rotating CaF_2 windows with galvanometers, which is known as a Brewster-plate spoiler, which averaged out the fringes in detection. Together, these improved the sensitivity by more than an order of magnitude and have enabled extended spectroscopic surveys of molecular ions in the mid-IR. J. N. Hodges, A. J. Perry, P. A. Jenkins II, B. M. Siller, and B. J. McCall, J. Chem. Phys. (2013), 139, 164201. C. R. Webster, J. Opt. Soc. Am. B (1985), 2, 1464. C. R. Markus, A. J. Perry, J. N. Hodges, and B. J. McCall, Opt. Express (2017), 25, 3709-3721.

Optimization of reaction parameters in hydrothermal synthesis: a strategy towards the formation of CuS hexagonal plates

PubMed Central

2013-01-01

Background For decades, copper sulphide has been renowned as the superior optical and semiconductor materials. Its potential applications can be ranged from solar cells, lithium-ion batteries, sensors, and catalyst systems. The synthesis methodologies of copper sulphide with different controlled morphology have been widely explored in the literature. Nevertheless, the understanding on the formation chemistry of CuS is still limited. The ultimate approach undertaking in this article is to investigate the formation of CuS hexagonal plates via the optimization of reaction parameters in hydrothermal reaction between copper (II) nitrate and sodium thiosulphate without appending any assistant agent. Results Covellite (CuS) hexagonal plates were formed at copper ion: thiosulphate ion (Cu2+:S2O32−) mole ratio of 1:2 under hydrothermal treatment of 155°C for 12 hours. For synthesis conducted at reaction temperature lower than 155°C, copper sulphate (CuSO4), krohnite (NaCu2(SO4)(H2O)2] and cyclooctasulphur (S8) were present as main impurities with covellite (CuS). When Cu2+:S2O32− mole ratio was varied to 1: 1 and 1: 1.5, phase pure plate-like natrochalcite [NaCu2(SO4)(H2O)] and digenite (Cu9S5) were produced respectively. Meanwhile, mixed phases of covellite (CuS) and cyclooctasulphur (S8) were both identified when Cu2+:S2O32− mole ratio was varied to 1: 2.5, 1: 3 and 1: 5 as well as when reaction time was shortened to 1 hour. Conclusions CuS hexagonal plates with a mean edge length of 1 μm, thickness of 100 nm and average crystallite size of approximately (45 ± 2) nm (Scherrer estimation) were successfully synthesized via assisting agent- free hydrothermal method. Under a suitable Cu2+:S2O32− mole ratio, we evidenced that the formation of covellite (CuS) is feasible regardless of the reaction temperature applied. However, a series of impurities were attested with CuS if reaction temperature was not elevated high enough for the additional crystallite phase decomposition. It was also identified that Cu2+:S2O32− mole ratio plays a vital role in controlling the amount of cyclooctasulphur (S8) in the final powder obtained. Finally, reaction time was recognized as an important parameter in impurity decomposition as well as increasing the crystallite size and crystallinity of the CuS hexagonal plates formed. PMID:23575312

Ion-induced electron emission microscopy

DOEpatents

Doyle, Barney L.; Vizkelethy, Gyorgy; Weller, Robert A.

2001-01-01

An ion beam analysis system that creates multidimensional maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the secondary electrons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted secondary electrons are collected in a strong electric field perpendicular to the sample surface and (optionally) projected and refocused by the electron lenses found in a photon emission electron microscope, amplified by microchannel plates and then their exact position is sensed by a very sensitive X Y position detector. Position signals from this secondary electron detector are then correlated in time with nuclear, atomic or electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these secondary electrons in the fit place.

A Systematic Study on the Generation of Multimetallic Lanthanide Fullerene ions by Laser Ablation Mass Spectrometry.

PubMed

Wang, Yiyun; Ma, LiFu; Mu, Lei; Ren, Juan; Kong, Xianglei

2018-06-01

Laser ablation masss spectromety has been previously proved to be a powerful tool for studying endohedro metallofullerene (EMF) ions. Our previous study showed the possiblity of forming multi-metallofullerene ions containg more than six metal atoms for La, Y and Lu. Thus, it is important to conduct a systematic study on the generation of multi-metallofullerenes and their distribuitons for all lanthanide elements. Experiments were performed on a 7.0 T Fourier transform ion cyclotron resonance (FT ICR) mass spectrometer. Laser ablation mass spectra were obtained by laser irradiation on mixtures of graphene and MCl 3 on a stainless steel plate, applying a 355 nm Nd: YAG laser with a typical energy of 2.5 mJ/pulse. Reaction test experiments were performed by introducing O 2 into the FT ICR cell with a pulse valve. Multi-metallofullerene ions Ce2-4C2m+, Pr2-4C2m+, Gd2-4C2m+, Nd3C2m+, Dy2-3C2m+, Tb2-7C2m+, Ho2-6C2m+ were observed in the mass spectra. For metal Sm and Eu, no multi-metallofullerene ion was observed. No reaction with O 2 was observed in the reaction experiments, verifying that these species had endohedral structures. For the observed series of multi-metallofullerene ions, tri-metallofullerene ions dominated their mass spectra. The results were further compared with previously generated EMF ions for La, Er, Tm, Yb and Lu. Endohedral lanthanide metallofullerene ions were generated by laser ablation of graphene and the corresponding metal salts MCl 3 (M = Ce, Pr, Nd, Gd, Tb, Dy and Ho) and studied with a FT ICR mass spectrometer. Typically, multi-metallofullerene ions of TbnC2m+2≤n≤780≤2m≤176, Ho6C2m+2≤n≤674≤2m≤162 were observed. The results show that the formation of multi-EMF ions containing lanthanides that have +3 and +4 oxidation states is easier than those containing +2 oxidation states in the process of laser ablation. This article is protected by copyright. All rights reserved.

CALUTRON RECEIVER

DOEpatents

Brunk, W.O.

1959-09-29

A description is given for an improved calutron receiver having a face plate lying at an angle to the direction of the entering ion beams but having an opening, the plane of which is substantially perpendicular to that of the entering ion beams. By so positioning the opening in the receiver, the effective area through which the desired material may enter the receiver is increased, and at the same time the effective area through which containattng material may enter the receiver is reduced.

Method and apparatus for detection of charge on ions and particles

DOEpatents

Fuerstenau, Stephen Douglas; Soli, George Arthur

2002-01-01

The present invention provides a tessellated array detector with charge collecting plate (or cup) electrode pixels and amplifying circuitry integrated into each pixel making it sensitive to external electrostatic charge; a micro collector/amplifier pixel design possessing a small capacitance to ensure a high charge to voltage signal conversion for low noise/high sensitivity operation; a micro-fabricated array of such pixels to create a useful macroscopic target area for ion and charged particle collection.

Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies.

PubMed

Jeong, Tae Won; Singh, P K; Scullion, C; Ahmed, H; Kakolee, K F; Hadjisolomou, P; Alejo, A; Kar, S; Borghesi, M; Ter-Avetisyan, S

2016-08-01

The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles' impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5-58 MeV carbon ions and for protons in the energy range 2-17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies

NASA Astrophysics Data System (ADS)

Jeong, Tae Won; Singh, P. K.; Scullion, C.; Ahmed, H.; Kakolee, K. F.; Hadjisolomou, P.; Alejo, A.; Kar, S.; Borghesi, M.; Ter-Avetisyan, S.

2016-08-01

The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles' impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5-58 MeV carbon ions and for protons in the energy range 2-17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

Simultaneous measurements of ion and electron currents using a novel compact electrostatic end-loss-current detector

NASA Astrophysics Data System (ADS)

Hirata, M.; Miyake, Y.; Cho, T.; Kohagura, J.; Numakura, T.; Shimizu, K.; Ito, M.; Kiminami, S.; Morimoto, N.; Hirai, K.; Yamagishi, T.; Miyata, Y.; Nakashima, Y.; Miyoshi, S.; Ogura, K.; Kondoh, T.; Kariya, T.

2006-10-01

For the purpose of end-loss-ion and -electron analyses in open-field plasmas, a compact-sized electrostatic end-loss-current detector is proposed on the basis of a self-collection principle for suppressing the effects of secondary-electron emission from a metal collector. For employing this specific method, it is worth noting that no further additional magnetic systems except the ambient open-ended magnetic fields are required in the detector operation. This characteristic property provides a compactness of the total detection system and availability for its use in plasma confinement devices without disturbing plasma-confining magnetic fields. The detector consists of a set of parallel metal plates with respect to lines of ambient magnetic forces of a plasma device for analyzing incident ion currents along with a grid for shielding the collector against strays due to the metal-plate biasing. The characterization experiments are carried out by the use of a test-ion-beam line along with an additional use of a Helmholtz coil system for the formation of open magnetic fields similar to those in the GAMMA 10 end region. The applications of the developed end-loss-current detector in the GAMMA 10 plasma experiments are demonstrated under the conditions with simultaneous incidence of energetic electrons produced by electron-cyclotron heatings for end-loss-plugging potential formation.

Scintillator based detector for fast-ion losses induced by magnetohydrodynamic instabilities in the ASDEX upgrade tokamak.

PubMed

García-Muñoz, M; Fahrbach, H-U; Zohm, H

2009-05-01

A scintillator based detector for fast-ion losses has been designed and installed on the ASDEX upgrade (AUG) tokamak [A. Herrmann and O. Gruber, Fusion Sci. Technol. 44, 569 (2003)]. The detector resolves in time the energy and pitch angle of fast-ion losses induced by magnetohydrodynamics (MHD) fluctuations. The use of a novel scintillator material with a very short decay time and high quantum efficiency allows to identify the MHD fluctuations responsible for the ion losses through Fourier analysis. A Faraday cup (secondary scintillator plate) has been embedded behind the scintillator plate for an absolute calibration of the detector. The detector is mounted on a manipulator to vary its radial position with respect to the plasma. A thermocouple on the inner side of the graphite protection enables the safety search for the most adequate radial position. To align the scintillator light pattern with the light detectors a system composed by a lens and a vacuum-compatible halogen lamp has been allocated within the detector head. In this paper, the design of the scintillator probe, as well as the new technique used to analyze the data through spectrograms will be described. A last section is devoted to discuss the diagnosis prospects of this method for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)].

Conception through build of an automated liquids processing system for compound management in a low-humidity environment.

PubMed

Belval, Richard; Alamir, Ab; Corte, Christopher; DiValentino, Justin; Fernandes, James; Frerking, Stuart; Jenkins, Derek; Rogers, George; Sanville-Ross, Mary; Sledziona, Cindy; Taylor, Paul

2012-12-01

Boehringer Ingelheim's Automated Liquids Processing System (ALPS) in Ridgefield, Connecticut, was built to accommodate all compound solution-based operations following dissolution in neat DMSO. Process analysis resulted in the design of two nearly identical conveyor-based subsystems, each capable of executing 1400 × 384-well plate or punch tube replicates per batch. Two parallel-positioned subsystems are capable of independent execution or alternatively executed as a unified system for more complex or higher throughput processes. Primary ALPS functions include creation of high-throughput screening plates, concentration-response plates, and reformatted master stock plates (e.g., 384-well plates from 96-well plates). Integrated operations included centrifugation, unsealing/piercing, broadcast diluent addition, barcode print/application, compound transfer/mix via disposable pipette tips, and plate sealing. ALPS key features included instrument pooling for increased capacity or fail-over situations, programming constructs to associate one source plate to an array of replicate plates, and stacked collation of completed plates. Due to the hygroscopic nature of DMSO, ALPS was designed to operate within a 10% relativity humidity environment. The activities described are the collaborative efforts that contributed to the specification, build, delivery, and acceptance testing between Boehringer Ingelheim Pharmaceuticals, Inc. and the automation integration vendor, Thermo Scientific Laboratory Automation (Burlington, ON, Canada).

Advanced Sensor Technologies for Next-Generation Vehicles

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

Sheen, S H; Chien, H T; Gopalsami, N

2002-01-30

This report summarizes the development of automobile emissions sensors at Argonne National Laboratory. Three types of sensor technologies, i.e., ultrasound, microwave, and ion-mobility spectrometry (IMS), were evaluated for engine-out emissions monitoring. Two acoustic sensor technologies, i.e., surface acoustic wave and flexural plate wave, were evaluated for detection of hydrocarbons. The microwave technique involves a cavity design and measures the shifts in resonance frequency that are a result of the presence of trace organic compounds. The IMS technique was chosen for further development into a practical emissions sensor. An IMS sensor with a radioactive {sup 63}Ni ion source was initially developedmore » and applied to measurement of hydrocarbons and NO{sub x} emissions. For practical applications, corona and spark discharge ion sources were later developed and applied to NO{sub x} emission measurement. The concentrations of NO{sub 2} in dry nitrogen and in a typical exhaust gas mixture are presented. The sensor response to moisture was evaluated, and a cooling method to control the moisture content in the gas stream was examined. Results show that the moisture effect can be reduced by using a thermoelectric cold plate. The design and performance of a laboratory prototype sensor are described.« less

ELISA - an electrostatic storage ring for low-energy ions

NASA Astrophysics Data System (ADS)

Pape Moeller, Soeren

1997-05-01

The design of a new type of storage ring for low-energy ions using electrostatic deflection and focusing devices is described. Electrostatic bends and quadrupoles are used since they are more efficient than magnetic ones for low-velocity heavy ions. Furthermore, electrostatic devices are more compact and easier to construct than magnetic devices. In comparison to an electromagnetic trap, one important advantage of the elecrostatic ring is the easy access to the circulating beam and its decay products. These and other features, e.g. no magnetic fields, makes such storage devices attractive for many atomic-physics experiments. Also neigboring fields as chemistry and biology might benefit from such an relatively inexpensive device. One important difference between an electrostatic and a magnetic ring is, that the longitudinal energy is not conserved for the electrostatic ring. The actual ring will have a race-track shape as defined by two straight sections each with two quadrupole doublets connected by 180-degrees bends. The bends will consist of 160-degrees spherical deflection plates surrounded by two parallel plate 10-degrees bends. The storage ring ELISA, currently being built, will have a circumference of 6 meters. The first beam tests will take place during summer 1996.

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

Gundlach-Graham, Alexander W.; Dennis, Elise; Ray, Steven J.

Here we describe the first combination of a Distance-of-Flight Mass Spectrometry (DOFMS) instrument and an inductively coupled plasma (ICP) ion source. DOFMS is a velocity-based MS technique in which ions of a range of mass-to-charge (m/z) values are detected simultaneously along the length of a spatially selective detector. As a relative of time-of-flight (TOF) MS, DOFMS leverages benefits fromboth TOFMS and spatially dispersive MS. The simultaneous detection of groups of m/z values improves dynamic range by spreading ion signal across many detector elements and reduces correlated noise by signal ratioing. To ascertain the performance characteristics of the ICP-DOFMS instrument, wemore » have employed a microchannel-plate/phosphor detection assembly with a scientific CCD to capture images of the phosphor plate. With this simple (and commercially available) detection scheme, elemental detection limits from 2–30 ng L*1 and a linear dynamic range of 5 orders of magnitude (10–106 ng L1) have been demonstrated. Additionally, a competitive isotope-ratio precision of 0.1% RSD has been achieved with only a 6 s signal integration period. In addition to first figures of merit, this paper outlines technical considerations for the design of the ICP-DOFMS.« less

Thermal and Surface Evaluation on The Process of Forming a Cu2O/CuO Semiconductor Photocatalyst on a Thin Copper Plate

NASA Astrophysics Data System (ADS)

Zainul, R.; Oktavia, B.; Dewata, I.; Efendi, J.

2018-04-01

This research aims to investigate the process of forming a multi-scale copper oxide semiconductor (CuO/Cu2O) through a process of calcining a copper plate. The changes that occur during the formation of the oxide are thermally and surface evaluated. Evaluation using Differential Thermal Analysis (DTA) obtained by surface change of copper plate happened at temperature 380°C. Calcination of oxide formation was carried out at temperature 380°C for 1 hour. Surface evaluation process by using Scanning Electron Microscope (SEM) surface and cross-section, to determine diffusion of oxide formation on copper plate. The material composition is monitored by XRF and XRD to explain the process of structural and physical changes of the copper oxide plate formed during the heating process. The thickness of Cu plates used is 200-250 μm. SEM analysis results, the oxygen atom interruption region is in the range of 20-30 μm, and diffuses deeper during thermal oxidation process. The maximum diffusion depth of oxygen atoms reaches 129 μm.

Status of Beam Line Detectors for the BigRIPS Fragment Separator at RIKEN RI Beam Factory: Issues on High Rates and Resolution

NASA Astrophysics Data System (ADS)

Sato, Yuki; Fukuda, Naoki; Takeda, Hiroyuki; Kameda, Daisuke; Suzuki, Hiroshi; Shimizu, Yohei; Ahn, DeukSoon; Murai, Daichi; Inabe, Naohito; Shimaoka, Takehiro; Tsubota, Masakatsu; Kaneko, Junichi H.; Chayahara, Akiyoshi; Umezawa, Hitoshi; Shikata, Shinichi; Kumagai, Hidekazu; Murakami, Hiroyuki; Sato, Hiromi; Yoshida, Koichi; Kubo, Toshiyuki

A multiple sampling ionization chamber (MUSIC) and parallel-plate avalanche counters (PPACs) were installed within the superconducting in-flight separator, named BigRIPS, at the RIKEN Nishina Center for particle identification of RI beams. The MUSIC detector showed negligible charge collection inefficiency from recombination of electrons and ions, up to a 99-kcps incidence rate for high-energy heavy ions. For the PPAC detectors, the electrical discharge durability for incident heavy ions was improved by changing the electrode material. Finally, we designed a single crystal diamond detector, which is under development for TOF measurements of high-energy heavy ions, that has a very fast response time (pulse width <1 ns).

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

Sakaki, H.; Fukuda, Y.; Nishiuchi, M.

A single-shot-imaging thin scintillator film was developed for an online Thomson parabola (TP) spectrometer and the first analysis of laser accelerated ions, using the online TP spectrometer, was demonstrated at the JAEA-Kansai Advanced Relativistic Engineering Laser System (J-KAREN). An energy spectrum of {approx}4.0 MeV protons is obtained using only this imaging film without the need of a microchannel plate that is typically utilized in online ion analyses. A general-purpose Monte Carlo particle and heavy ion-transport code system, which consists of various quantum dynamics models, was used for the prediction of the luminescent properties of the scintillator. The simulation can reasonablymore » predict not only the ion trajectories detected by the spectrometer, but also luminescence properties.« less

Measurement of laser activated electron tunneling from semiconductor zinc oxide to adsorbed organic molecules by a matrix assisted laser desorption ionization mass spectrometer.

PubMed

Zhong, Hongying; Fu, Jieying; Wang, Xiaoli; Zheng, Shi

2012-06-04

Measurement of light induced heterogeneous electron transfer is important for understanding of fundamental processes involved in chemistry, physics and biology, which is still challenging by current techniques. Laser activated electron tunneling (LAET) from semiconductor metal oxides was observed and characterized by a MALDI (matrix assisted laser desorption ionization) mass spectrometer in this work. Nanoparticles of ZnO were placed on a MALDI sample plate. Free fatty acids and derivatives were used as models of organic compounds and directly deposited on the surface of ZnO nanoparticles. Irradiation of UV laser (λ=355 nm) with energy more than the band gap of ZnO produces ions that can be detected in negative mode. When TiO(2) nanoparticles with similar band gap but much lower electron mobility were used, these ions were not observed unless the voltage on the sample plate was increased. The experimental results indicate that laser induced electron tunneling is dependent on the electron mobility and the strength of the electric field. Capture of low energy electrons by charge-deficient atoms of adsorbed organic molecules causes unpaired electron-directed cleavages of chemical bonds in a nonergodic pathway. In positive detection mode, electron tunneling cannot be observed due to the reverse moving direction of electrons. It should be able to expect that laser desorption ionization mass spectrometry is a new technique capable of probing the dynamics of electron tunneling. LAET offers advantages as a new ionization dissociation method for mass spectrometry. Copyright © 2012 Elsevier B.V. All rights reserved.

Signal processing of bedload transport impact amplitudes on accelerometer instrumented plates

USDA-ARS?s Scientific Manuscript database

This work was performed to help establish a data processing methodology for relating accelerometer signals caused by impacts of gravel on steel plates to the mass and size of the transported material. Signal processing was performed on impact plate data collected in flume experiments at the Nationa...

Biomechanics of lateral lumbar interbody fusion constructs with lateral and posterior plate fixation: laboratory investigation.

PubMed

Fogel, Guy R; Parikh, Rachit D; Ryu, Stephen I; Turner, Alexander W L

2014-03-01

Lumbar interbody fusion is indicated in the treatment of degenerative conditions. Laterally inserted interbody cages significantly decrease range of motion (ROM) compared with other cages. Supplemental fixation options such as lateral plates or spinous process plates have been shown to provide stability and to reduce morbidity. The authors of the current study investigate the in vitro stability of the interbody cage with a combination of lateral and spinous process plate fixation and compare this method to the established bilateral pedicle screw fixation technique. Ten L1-5 specimens were evaluated using multidirectional nondestructive moments (± 7.5 N · m), with a custom 6 degrees-of-freedom spine simulator. Intervertebral motions (ROM) were measured optoelectronically. Each spine was evaluated under the following conditions at the L3-4 level: intact; interbody cage alone (stand-alone); cage supplemented with lateral plate; cage supplemented with ipsilateral pedicle screws; cage supplemented with bilateral pedicle screws; cage supplemented with spinous process plate; and cage supplemented with a combination of lateral plate and spinous process plate. Intervertebral rotations were calculated, and ROM data were normalized to the intact ROM data. The stand-alone laterally inserted interbody cage significantly reduced ROM with respect to the intact state in flexion-extension (31.6% intact ROM, p < 0.001), lateral bending (32.5%, p < 0.001), and axial rotation (69.4%, p = 0.002). Compared with the stand-alone condition, addition of a lateral plate to the interbody cage did not significantly alter the ROM in flexion-extension (p = 0.904); however, it was significantly decreased in lateral bending and axial rotation (p < 0.001). The cage supplemented with a lateral plate was not statistically different from bilateral pedicle screws in lateral bending (p = 0.579). Supplemental fixation using a spinous process plate was not significantly different from bilateral pedicle screws in flexion-extension (p = 0.476). The combination of lateral plate and spinous process plate was not statistically different from the cage supplemented with bilateral pedicle screws in all the loading modes (p ≥ 0.365). A combination of lateral and spinous process plate fixation to supplement a laterally inserted interbody cage helps achieve rigidity in all motion planes similar to that achieved with bilateral pedicle screws.

New design for a time-of-flight mass spectrometer with a liquid beam laser desorption ion source for the analysis of biomolecules

NASA Astrophysics Data System (ADS)

Charvat, A.; Lugovoj, E.; Faubel, M.; Abel, B.

2004-05-01

We describe a novel liquid beam mass spectrometer, based on a recently discovered nanosecond laser desorption phenomenon, [W. Kleinekofort, J. Avdiev, and B. Brutschy, Int. J. Mass Ion. Processes 152, 135 (1996)] which allows the liquid-to-vacuum transfer, and subsequent mass analysis of pre-existing ions and ionic associates from liquid microjets of aqueous solutions. The goal of our novel technical approach is to establish a system with good mass resolution that implements improvements on critical components that make the system more reliable and easier to operate. For laser desorption pulsed dye-laser difference frequency mixing is used that provides tunable infrared light near the absorption maximum of liquid water around 3 μm. Different types of liquid beam glass nozzles (convergent capillary and aperture plate nozzles) are investigated and characterized. Starting from theoretical considerations of hydrodynamic drag forces on micrometer size droplets in supersonic rarefied gas flows we succeeded in capturing efficiently the liquid beam in a liquid beam recycling trap operating at the vapor pressure of liquid water. For improving the pollution resistance, the liquid jet high vacuum ion source region is spatially separated from the reflectron time-of-flight mass spectrometer (TOF-MS) working behind a gate valve in an ultrahigh vacuum environment. A simple (simulation optimized) ion optics is employed for the ion transfer from the source to the high vacuum region. This new feature is also mostly responsible for the improved mass resolution. With the present tandem-TOF-MS setup a resolution of m/Δm≈1800 for the low and m/Δm≈700 in the high mass region has been obtained for several biomolecules of different mass and complexity (amino acids, insulin, and cytochrome c).

Analysis of Interplanetary Dust Experiment Detectors and Other Witness Plates

NASA Technical Reports Server (NTRS)

Griffis, D. P.; Wortman, J. J.

1992-01-01

The development of analytical procedures for identifying the chemical composition of residue from impacts that occurred on the Interplanetary Dust Experiment (IDE) detectors during the flight of Long Duration Exposure Facility (LDEF) and the carrying out of actual analysis on IDE detectors and other witness plates are discussed. Two papers on the following topics are presented: (1) experimental analysis of hypervelocity microparticle impact sites on IDE sensor surfaces; and (2) contaminant interfaces with secondary Ion Mass Spectrometer (SIMS) analysis of microparticle impactor residues on LDEF surfaces.

An orientation analysis method for protein immobilized on quantum dot particles

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Inoue, Masae

2009-11-01

The evaluation of orientation of biomolecules immobilized on nanodevices is crucial for the development of high performance devices. Such analysis requires ultra high sensitivity so as to be able to detect less than one molecular layer on a device. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has sufficient sensitivity to evaluate the uppermost surface structure of a single molecular layer. The objective of this study is to develop an orientation analysis method for proteins immobilized on nanomaterials such as quantum dot particles, and to evaluate the orientation of streptavidin immobilized on quantum dot particles by means of TOF-SIMS. In order to detect fragment ions specific to the protein surface, a monoatomic primary ion source (Ga +) and a cluster ion source (Au 3+) were employed. Streptavidin-immobilized quantum dot particles were immobilized on aminosilanized ITO glass plates at amino groups by covalent bonding. The reference samples streptavidin directly immobilized on ITO plates were also prepared. All samples were dried with a freeze dryer before TOF-SIMS measurement. The positive secondary ion spectra of each sample were obtained using TOF-SIMS with Ga + and Au 3+, respectively, and then they were compared so as to characterize each sample and detect the surface structure of the streptavidin immobilized with the biotin-immobilized quantum dots. The chemical structures of the upper surface of the streptavidin molecules immobilized on the quantum dot particles were evaluated with TOF-SIMS spectra analysis. The indicated surface side of the streptavidin molecules immobilized on the quantum dots includes the biotin binding site.

The new Heavy-ion MCP-based Ancillary Detector DANTE for the CLARA-PRISMA Setup

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

Valiente-Dobon, J. J.; Gadea, A.; Corradi, L.

2006-08-14

The CLARA-PRISMA setup is a powerful tool for spectroscopic studies of neutron-rich nuclei produced in multi-nucleon transfer and deep-inelastic reactions. It combines the large acceptance spectrometer PRISMA with the {gamma}-ray array CLARA. At present, the ancillary heavy-ion detector DANTE, based on Micro-Channel Plates to be installed at the CLARA-PRISMA setup, is being constructed at LNL. DANTE will open the possibility of measuring {gamma}-{gamma} Doppler-corrected coincidences for the events outside the acceptance of PRISMA. In this presentation, it is described the heavy-ion detector DANTE, as well as the performances of the first prototype.

Dense proton injection into phosphate glasses using corona discharge treatment

NASA Astrophysics Data System (ADS)

Kinoshita, Takuya; Miyazaki, Atsushi; Kawaguchi, Keiga; Sakai, Daisuke; Yamaguchi, Takuya; Omata, Takahisa; Ishiyama, Tomohiro; Fujioka, Masaya; Kaiju, Hideo; Nishii, Junji

2018-01-01

Sodium ions in 25NaO1/2-6LaO3/2-6GeO2-63PO5/2 (mol%) glasses were substituted with protons using corona discharge treatment (CDT) under a H2 atmosphere. The substitution of sodium ion to proton proceeded from the anode side to the cathode side with constant current flow during the CDT. A crystalline free and transparent glass plate of 0.3 mm thickness was obtained after CDT for 96 h. The maximum decrease rate from sodium ion to proton was 78 ± 10%. The proton conductivity of 8.5 × 10-4 S/cm was attained at 400 °C.

Pliocene eclogite exhumation at plate tectonic rates in eastern Papua New Guinea.

PubMed

Baldwin, Suzanne L; Monteleone, Brian D; Webb, Laura E; Fitzgerald, Paul G; Grove, Marty; Hill, E June

2004-09-16

As lithospheric plates are subducted, rocks are metamorphosed under high-pressure and ultrahigh-pressure conditions to produce eclogites and eclogite facies metamorphic rocks. Because chemical equilibrium is rarely fully achieved, eclogites may preserve in their distinctive mineral assemblages and textures a record of the pressures, temperatures and deformation the rock was subjected to during subduction and subsequent exhumation. Radioactive parent-daughter isotopic variations within minerals reveal the timing of these events. Here we present in situ zircon U/Pb ion microprobe data that dates the timing of eclogite facies metamorphism in eastern Papua New Guinea at 4.3 +/- 0.4 Myr ago, making this the youngest documented eclogite exposed at the Earth's surface. Eclogite exhumation from depths of approximately 75 km was extremely rapid and occurred at plate tectonic rates (cm yr(-1)). The eclogite was exhumed within a portion of the obliquely convergent Australian-Pacific plate boundary zone, in an extending region located west of the Woodlark basin sea floor spreading centre. Such rapid exhumation (> 1 cm yr(-1)) of high-pressure and, we infer, ultrahigh-pressure rocks is facilitated by extension within transient plate boundary zones associated with rapid oblique plate convergence.

Innovative microchannel plate with reformulation of composition and modification of microstructure

NASA Astrophysics Data System (ADS)

Pan, Jingsheng; Lv, Jingwen; Kesaev, S. A.; Liu, Shulin; Liu, Zhanying; Li, Junguo; Chong, Xiaoqin; Shu, Detan

2009-07-01

The signal-to-noise ratio (SNR) and mean time to failure (MTTF) are two important attributes to describe the performance and operation life of an image intensifier. The presents of the ion barrier film (IBF) in Gen. III image intensifier, which used to suppress MCP's ion feedback, while dramatically improve the MTTF but significantly reduce the SNR, so more completely diminishing the ion poisoning source within the channels of MCP are crucial for improved Gen. III; image intensifier to thinned thickness IBF and achieving this two conflicting attributes promotion simultaneously. This research was originally initiated to develop a MCP with glass composition redesigned specially for GaAs photocathode image intensifier, proved which can be imposed an exceedingly intensive electron bombard degassing but without suffering a fatal gain degrade, and had achieved significantly improved SNR of Gen. III image intensifier but with a short distance to meet the lifetime success, so that our research work step forward to intent upon the restriction of ion poisoning source formation within the MCP substrate, we reformulated the MCP glass composition, and modified the microstructure of this MCP glass substrate though a glass-crystal phase transition during the MCP fabricate heating process, we present an innovative MCP based on a glass-ceramic substrate, with reformulated composition and close-linked network microstructure mix with many of nanometer size crystal grains, provide this MCP with sustainable high gain, lower ion feedback and less outgasing performance, this glass-ceramic MCPs are assembled to Gen. III image intensifiers which results showing promoting both the MTTF and SNR of Gen. III image intensifier.

Formation of Porous Germanium Layers by Silver-Ion Implantation

NASA Astrophysics Data System (ADS)

Stepanov, A. L.; Vorob'ev, V. V.; Nuzhdin, V. I.; Valeev, V. F.; Osin, Yu. N.

2018-04-01

We propose a method for the formation of porous germanium ( P-Ge) layers containing silver nanoparticles by means of high-dose implantation of low-energy Ag+ ions into single-crystalline germanium ( c-Ge). This is demonstrated by implantation of 30-keV Ag+ ions into a polished c-Ge plate to a dose of 1.5 × 1017 ion/cm2 at an ion beam-current density of 5 μA/cm2. Examination by high-resolution scanning electron microscopy (SEM), atomic-force microscopy (AFM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX) microanalysis, and reflection high-energy electron diffraction (RHEED) showed that the implantation of silver ions into c-Ge surface led to the formation of a P-Ge layer with spongy structure comprising a network of interwoven nanofibers with an average diameter of ˜10-20 nm Ag nanoparticles on the ends of fibers. It is also established that the formation of pores during Ag+ ion implantation is accompanied by effective sputtering of the Ge surface.

Fuel cell plates with improved arrangement of process channels for enhanced pressure drop across the plates

DOEpatents

Spurrier, Francis R.; Pierce, Bill L.; Wright, Maynard K.

1986-01-01

A plate for a fuel cell has an arrangement of ribs defining an improved configuration of process gas channels and slots on a surface of the plate which provide a modified serpentine gas flow pattern across the plate surface. The channels are generally linear and arranged parallel to one another while the spaced slots allow cross channel flow of process gas in a staggered fashion which creates a plurality of generally mini-serpentine flow paths extending transverse to the longitudinal gas flow along the channels. Adjacent pairs of the channels are interconnected to one another in flow communication. Also, a bipolar plate has the aforementioned process gas channel configuration on one surface and another configuration on the opposite surface. In the other configuration, there are not slots and the gas flow channels have a generally serpentine configuration.

Measurement of ultra-low ion energy of decelerated ion beam using a deflecting electric field

NASA Astrophysics Data System (ADS)

Thopan, P.; Suwannakachorn, D.; Tippawan, U.; Yu, L. D.

2015-12-01

In investigation on ultra-low-energy ion bombardment effect on DNA, an ion beam deceleration lens was developed for high-quality ultra-low-energy ion beam. Measurement of the ion energy after deceleration was necessary to confirm the ion beam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the ion beam. The beam bending distance depended on the ion energy and was described and simulated. A system for the measurement of the ion beam energy was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect ion beam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the ion-beam deceleration lens inside the large chamber of the bioengineering vertical ion beam line. Moving the measurement rod across the decelerated ion beam enabled to obtain beam profiles, from which the beam bending distance could be known and the ion beam energy could be calculated. The measurement results were in good agreement with theoretical and simulated results.

Method and apparatus for capacitive deionization and electrochemical purification and regeneration of electrodes

DOEpatents

Farmer, Joseph C.

1999-01-01

An electrically regeneratable electrochemical cell (30) for capacitive deionization and electrochemical purification and regeneration of electrodes includes two end plates (31, 32), one at each end of the cell (30). Two end electrodes (35, 36) are arranged one at each end of the cell (30), adjacent to the end plates (31, 32). An insulator layer (33) is interposed between each end plate (31, 32) and the adjacent end electrode (35, 36). Each end electrode (35, 36) includes a single sheet (44) of conductive material having a high specific surface area and sorption capacity. In one embodiment, the sheet (44) of conductive material is formed of carbon aerogel composite. The cell (30) further includes a plurality of generally identical double-sided intermediate electrodes (37-43) that are equidistally separated from each other, between the two end electrodes (35, 36). As the electrolyte enters the cell, it flows through a continuous open serpentine channel (65-71) defined by the electrodes, substantially parallel to the surfaces of the electrodes. By polarizing the cell (30), ions are removed from the electrolyte and are held in the electric double layers formed at the carbon aerogel surfaces of the electrodes. As the cell (30) is saturated with the removed ions, the cell (30) is regenerated electrically, thus significantly minimizing secondary wastes.

Effect of calcium ions on the evolution of biofouling by Bacillus subtilis in plate heat exchangers simulating the heat pump system used with treated sewage in the 2008 Olympic Village.

PubMed

Tian, Lei; Chen, Xiao Dong; Yang, Qian Peng; Chen, Jin Chun; Shi, Lin; Li, Qiong

2012-06-01

Heat pump systems using treated sewage water as the heat source were used in the Beijing Olympic Village for domestic heating and cooling. However, considerable biofouling occurred in the plate heat exchangers used in the heat pump system, greatly limiting the system efficiency. This study investigates the biofouling characteristics using a plate heat exchanger in parallel with a flow cell system to focus on the effect of calcium ions on the biofilm development. The interactions between the microorganisms and Ca(2+) enhances both the extent and the rate of biofilm development with increasing Ca(2+) concentration, leading to increased heat transfer and flow resistances. Three stages of biofouling development were identified in the presence of Ca(2+) from different biofouling mass growth rates with an initial stage, a rapid growth stage and an extended growth stage. Each growth stage had different biofouling morphologies influenced by the Ca(2+) concentration. The effects of Ca(2+) on the biofouling heat transfer and flow resistances had a synergistic effect related to both the biofouling mass and the morphology. The effect of Ca(2+) on the biofouling development was most prominent during the rapid growth stage. Copyright © 2012 Elsevier B.V. All rights reserved.

Relative humidity effects on the surface electrical properties of resistive plate chamber melaminic laminates uncoated and coated with polymerized linseed oil film

NASA Astrophysics Data System (ADS)

Bearzotti, Andrea; Palummo, Lucrezia

2007-09-01

Relative humidity is an important quantity to control in many manufacturing environments such as semiconductor industry. Humidity and moisture can affect many electronic devices, generally rendering their operation worse. In this study we present results showing that in some specific applications, humidity can improve the performance of an electronic device. Resistive plate chambers are used as trigger detectors of the muon system in LHC (large hadron collider) experiments ATLAS (a toroidal LHC apparatus), CMS (compact muon solenoid) and ALICE (a large ion collider experiment) and as detector in cosmic rays experiment ARGO (astrophysical radiation with ground-based observatory). These detectors are made of phenolic-melaminic laminate electrodes, coated with a polymerized linseed oil film delimiting the gaseous sensitive volume. The loss of some of the detector capability can be progressive in time and due to the intrinsic limits of the detector materials. One of these effects is due to an increase of the total plate resistance, that is correlated to ion migration and relativity humidity phenomena. Our purpose is to understand the relative humidity (RH) influence on the conduction mechanisms on the electrodes surface. Results of amperometric measurements on laminate samples kept at a fixed temperature of 22°C, cycling RH between 10% and 90% are here presented.

EVALUATION OF THE EFFECTS OF PROCESSING DELAYS AND PROTECTIVE PLASTIC CASES ON IMAGE QUALITY OF A PHOTOSTIMULABLE PHOSPHOR PLATE SYSTEM

PubMed Central

Bramante, Clóvis Monteiro; Bramante, Alexandre Silva; de Souza, Rogério Emílio; Moraes, Ivaldo Gomes; Bernardineli, Norberti; Garcia, Roberto Brandão

2008-01-01

This ex vivo study evaluated the quality of digital radiographic images obtained with the photostimulable phosphor plate system (Digora) according to the processing delay and maintenance of optical plates in either opaque (supplied with the system) or transparent protective plastic cases during this period. Five radiographs were obtained from the mandibular molar region of a dry human mandible using optical plates. These plates were placed in the protective plastic cases before obtaining the radiographs and were processed immediately or after processing delays of 5, 60 and 120 min, when the case was removed. The results revealed a reduction in image quality when processing was delay 120 min compared to the other times. The opaque case provided better protection to the sensor than the transparent case. In conclusion, a 120-min processing delay for the Digora system caused a reduction in image quality, yet without interfering with the quality of diagnosis. The opaque case supplied by the system's manufacturer provided better protection to the optical plate than the transparent case. PMID:19089233

New, Efficient Optically Pumped Solid State Lasers.

DTIC Science & Technology

1989-02-21

Lasers", during the contract period from 15 August 1984 thru 11 November 1988 (AFOSR-88-0378) has led to some notable advances. This effort h,.s focused...lower laser states of both Er and 1Ho. This work has led to the inves t igation of the Nd,Er ion-ion interactions in other crystals such as Nd,Er:YALO...backed pyrex reflector. While the laser may work in a gold-plated cavity, the many visible, blue and near uv pump bands suggest better efficiency is

Anti-Biofilm Activity of Polyazolidinammonium Modified with Iodine Hydrate Ions against Microbial Biofilms of Uropathogenic Coliform Bacteria.

PubMed

Nechaeva, O V; Tikhomirova, E I; Zayarsky, D A; Bespalova, N V; Glinskaya, E V; Shurshalova, N F; Al Bayati, B M; Babailova, A I

2017-04-01

The dynamics of microbial biofilm formation by standard strain and by clinical strains of uropathogenic coliform bacteria was investigated in vitro and the effect of sublethal concentrations of the polymer compound polyazolidinammonium modified with iodine hydrate ions on the initial stages of biofilm formation was assessed. Treatment of immunological plate wells with the polymeric compound prevented film formation, especially in case of clinical E. coli strain carrying FimH virulence gene.

Electrochemical Migration Behavior of Copper-Clad Laminate and Electroless Nickel/Immersion Gold Printed Circuit Boards under Thin Electrolyte Layers

PubMed Central

Yi, Pan; Xiao, Kui; Ding, Kangkang; Dong, Chaofang; Li, Xiaogang

2017-01-01

The electrochemical migration (ECM) behavior of copper-clad laminate (PCB-Cu) and electroless nickel/immersion gold printed circuit boards (PCB-ENIG) under thin electrolyte layers of different thicknesses containing 0.1 M Na2SO4 was studied. Results showed that, under the bias voltage of 12 V, the reverse migration of ions occurred. For PCB-Cu, both copper dendrites and sulfate precipitates were found on the surface of FR-4 (board material) between two plates. Moreover, the Cu dendrite was produced between the two plates and migrated toward cathode. Compared to PCB-Cu, PCB-ENIG exhibited a higher tendency of ECM failure and suffered from seriously short circuit failure under high relative humidity (RH) environment. SKP results demonstrated that surface potentials of the anode plates were greater than those of the cathode plates, and those potentials of the two plates exhibited a descending trend as the RH increased. At the end of the paper, an electrochemical migration corrosion failure model of PCB was proposed. PMID:28772497

Backside contacted field effect transistor array for extracellular signal recording.

PubMed

Ingebrandt, S; Yeung, C K; Staab, W; Zetterer, T; Offenhäusser, A

2003-04-01

A new approach to the design of field-effect transistor (FET) sensors and the use of these FETs in detecting extracellular electrophysiological recordings is reported. Backside contacts were engineered by deep reactive ion etching and a gas phase boron doping process of the holes using planar diffusion sources. The metal contacts were designed to fit on top of the bonding pads of a standard industrial 22-pin DIL (dual inline) chip carrier. To minimise contact resistance, the metal backside contacts of the chips were electroless plated with gold. The chips were mounted on top of the bonding pads using a standard flip-chip process and a fineplacer unit previously described. Rat embryonic myocytes were cultured on these new devices (effective growth area 6 x 6 mm(2)) in order to confirm their validity in electrophysiological recording. Copyright 2003 Elsevier Science B.V.

Synthesis and characterization of hollow magnetic nanospheres modified with Au nanoparticles for bio-encapsulation

NASA Astrophysics Data System (ADS)

Seisno, Satoshi; Suga, Kent; Nakagawa, Takashi; Yamamoto, Takao A.

2017-04-01

Hollow magnetic nanospheres modified with Au nanoparticles were successfully synthesized. Au/SiO2 nanospheres fabricated by a radiochemical process were used as templates for ferrite templating. After the ferrite plating process, Au/SiO2 templates were fully coated with magnetite nanoparticles. Dissolution of the SiO2 core lead to the formation of hollow magnetic nanospheres with Au nanoparticles inside. The hollow magnetic nanospheres consisted of Fe3O4 grains, with an average diameter of 60 nm, connected to form the sphere wall, inside which Au grains with an average diameter of 7.2 nm were encapsulated. The Au nanoparticles immobilized on the SiO2 templates contributed to the adsorption of the Fe ion precursor and/or Fe3O4 seeds. These hollow magnetic nanospheres are proposed as a new type of nanocarrier, as the Au grains could specifically immobilize biomolecules inside the hollow sphere.

Engineering novel synthetic strategy to develop mesocarbon microbeads for multi-functional applications

NASA Astrophysics Data System (ADS)

Chaudhary, Anisha; Teotia, Satish; Kumar, Rajeev; Ramesha, K.; Dhakate, Sanjay R.; Kumari, Saroj

2018-04-01

To assess the challenge of affordable technology, present synthetic strategies can be extended to new low-cost synthesis and processing methods that have potential to tailor the properties of the materials. Here we report, a novel method for the synthesis of mesocarbon microbeads (MCMB) through a pre-processing involved pyrolysis technique. The resulting MCMB is compressed into a product and effects of heat treatment temperature on different properties of MCMB is studied. The use of MCMB for the electromagnetic interference (EMI) shielding is new and hence, the effect of heat treatment temperature on EMI shielding effectiveness is studied in X-band. It is observed that EMI shielding effectiveness increases to ‑39.6 dB on increasing the heat treatment temperature. The high conductivity of MCMB plate heat treated upto 2500 °C contributes to highly conducting networks. Additionally, to investigate the electrochemical performance of MCMB as an anode material for lithium ion batteries, 2500 °C heat treated MCMB powder is used to fabricate the electrode. The MCMB electrode exhibits high discharge capacity of 345 mAh g‑1 with a stable capacity for over 50 cycles and good rate capability. Thus, MCMB synthesized by this novel approach can be used for the development of high performance anode materials for Li-ion batteries.

Effect of nucleation time on bending response of ionic polymer–metal composite actuators

DOE PAGES

Kim, Suran; Hong, Seungbum; Choi, Yoon-Young; ...

2013-07-02

We attempted an autocatalytic electro-less plating of nickel in order to replace an electroless impregnation-reduction (IR) method in ionic polymer–metal composite (IPMC) actuators to reduce cost and processing time. Because nucleation time of Pd–Sn colloids is the determining factor of overall processing time, we used the nucleation time as our control parameter. In order to optimize nucleation time and investigate its effect on the performance of IPMC actuators, we analyzed the relationship between the nucleation time, interface morphology and electrical properties. The optimized nucleation time was 10 h. Furthermore, the trends of the performance and electrical properties as a functionmore » of nucleation time were attributed to the fact that the Ni penetration depth was determined by the minimum diffusion length of either Pd–Sn colloids or reducing agent ions. The Ni-IPMC actuators can be fabricated less than 14 h processing time without deteriorating performance of the actuators, which is comparable to Pt-IPMC prepared by IR method.« less

Mimicking electrodeposition in the gas phase: a programmable concept for selected-area fabrication of multimaterial nanostructures.

PubMed

Cole, Jesse J; Lin, En-Chiang; Barry, Chad R; Jacobs, Heiko O

2010-05-21

An in situ gas-phase process that produces charged streams of Au, Si, TiO(2), ZnO, and Ge nanoparticles/clusters is reported together with a programmable concept for selected-area assembly/printing of more than one material type. The gas-phase process mimics solution electrodeposition whereby ions in the liquid phase are replaced with charged clusters in the gas phase. The pressure range in which the analogy applies is discussed and it is demonstrated that particles can be plated into pores vertically (minimum resolution 60 nm) or laterally to form low-resistivity (48 microOmega cm) interconnects. The process is applied to the formation of multimaterial nanoparticle films and sensors. The system works at atmospheric pressure and deposits material at room temperature onto electrically biased substrate regions. The combination of pumpless operation and parallel nozzle-free deposition provides a scalable tool for printable flexible electronics and the capability to mix and match materials.

Beam quality corrections for parallel-plate ion chambers in electron reference dosimetry

NASA Astrophysics Data System (ADS)

Zink, K.; Wulff, J.

2012-04-01

Current dosimetry protocols (AAPM, IAEA, IPEM, DIN) recommend parallel-plate ionization chambers for dose measurements in clinical electron beams. This study presents detailed Monte Carlo simulations of beam quality correction factors for four different types of parallel-plate chambers: NACP-02, Markus, Advanced Markus and Roos. These chambers differ in constructive details which should have notable impact on the resulting perturbation corrections, hence on the beam quality corrections. The results reveal deviations to the recommended beam quality corrections given in the IAEA TRS-398 protocol in the range of 0%-2% depending on energy and chamber type. For well-guarded chambers, these deviations could be traced back to a non-unity and energy-dependent wall perturbation correction. In the case of the guardless Markus chamber, a nearly energy-independent beam quality correction is resulting as the effects of wall and cavity perturbation compensate each other. For this chamber, the deviations to the recommended values are the largest and may exceed 2%. From calculations of type-B uncertainties including effects due to uncertainties of the underlying cross-sectional data as well as uncertainties due to the chamber material composition and chamber geometry, the overall uncertainty of calculated beam quality correction factors was estimated to be <0.7%. Due to different chamber positioning recommendations given in the national and international dosimetry protocols, an additional uncertainty in the range of 0.2%-0.6% is present. According to the IAEA TRS-398 protocol, the uncertainty in clinical electron dosimetry using parallel-plate ion chambers is 1.7%. This study may help to reduce this uncertainty significantly.

Design and theoretical calculation of novel GeSn fully-depleted n-tunneling FET with quantum confinement model for suppression on GIDL effect

NASA Astrophysics Data System (ADS)

Liu, Xiangyu; Hu, Huiyong; Wang, Meng; Miao, Yuanhao; Han, Genquan; Wang, Bin

2018-06-01

In this paper, a novel fully-depleted Ge1-xSnx n-Tunneling FET (FD Ge1-xSnx nTFET) with field plate is investigated theoretically based on the experiment previously published. The energy band structures of Ge1-xSnx are calculated by EMP and the band-to-band tunneling (BTBT) parameters of Ge1-xSnx are calculated by Kane's model. The electrical characteristics of FD Ge1-xSnx nTFET and FD Ge1-xSnx nTFET with field plate (FD-FP Ge1-xSnx nTFET) having various Sn compositions are investigated and simulated with quantum confinement model. The results indicated that the GIDL effect is serious in FD Ge1-xSnx nTFET. By employing the field plate structure, the GIDL effect of FD-FP Ge1-xSnx nTFET is suppressed and the off-state current Ioff is decreased more than 2 orders of magnitude having Sn compositions from 0 to 0.06 compared with FD Ge1-xSnx nTFET. The impact of the difference of work function between field plate metal and channel Φfps is also studied. With the optimized Φfps = 0.0 eV, the on-state current Ion = 4.6 × 10-5 A/μm, the off-state current Ioff = 1.6 × 10-13 A/μm and the maximum on/off ration Ion/Ioff = 2.9 × 108 are achieved.

Plating To Reinforce Welded Joints

NASA Technical Reports Server (NTRS)

Otousa, J. E.

1982-01-01

Electrodeposition used to strengthen welded joints gouged, nicked, or suffered other mechanical damage. Plating cell, typically of acrylic plastic such as poly (Methylmetacrylate), is assembled around part to be plated. Areas not to be plated are masked with plater's tape. Weld area is plated in standard nickel-plating process.

Luminescence properties of Na3SrB5O10:Dy3+ plate-like microstructures for solid state lighting applications

NASA Astrophysics Data System (ADS)

Dillip, G. R.; Dhoble, S. J.; Raju, B. Deva Prasad

2013-10-01

A series of novel plate-like microstructure Na3SrB5O10 doped with various Dy3+ ions concentration have been synthesized for the first time by solid-state reaction (SSR) method. X-ray diffraction (XRD) results demonstrated that the prepared Na3SrB5O10:Dy3+ phosphors are single-phase pentaborates with triclinic structure. The plate-like morphology of the phosphor is examined by Field emission scanning electron microscopy (FE-SEM). The existence of both BO3 and BO4 groups in Na3SrB5O10:Dy3+ phosphors are identified by Fourier transform infrared (FT-IR) spectroscopy. Upon excitation at 385 nm, the PL spectra mainly comprising of two broad bands: one is a blue light emission (˜486 nm) and another is a yellow light emission (˜581 nm), originating from the transitions of 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 in 4f9 configuration of Dy3+ ions, respectively and the optimized dopant concentration is determined to be 3 at.%. Interestingly, the yellow-to-blue (Y/B) emission integrated intensity ratio is close to unity (0.99) for 3 at.% Dy3+ ions, suggesting that the phosphors are favor for white illumination. Moreover, the calculated Commission International de l'Eclairage (CIE) chromaticity coordinates of Na3SrB5O10:Dy3+ phosphors shows the values lie in white light region and the estimated CCT values are located in cool/day white light region.

Uranium-molybdenum nuclear fuel plates behaviour under heavy ion irradiation: An X-ray diffraction analysis

NASA Astrophysics Data System (ADS)

Palancher, H.; Wieschalla, N.; Martin, P.; Tucoulou, R.; Sabathier, C.; Petry, W.; Berar, J.-F.; Valot, C.; Dubois, S.

2009-03-01

Heavy ion irradiation has been proposed for discriminating UMo/Al specimens which are good candidates for research reactor fuels. Two UMo/Al dispersed fuels (U-7 wt%Mo/Al and U-10 wt%Mo/Al) have been irradiated with a 80 MeV 127I beam up to an ion fluence of 2 × 1017 cm-2. Microscopy and mainly X-ray diffraction using large and micrometer sized beams have enabled to characterize the grown interaction layer: UAl3 appears to be the only produced crystallized phase. The presence of an amorphous additional phase can however not be excluded. These results are in good agreement with characterizations performed on in-pile irradiated fuels and encourage new studies with heavy ion irradiation.

Accurate on line measurements of low fluences of charged particles

NASA Astrophysics Data System (ADS)

Palla, L.; Czelusniak, C.; Taccetti, F.; Carraresi, L.; Castelli, L.; Fedi, M. E.; Giuntini, L.; Maurenzig, P. R.; Sottili, L.; Taccetti, N.

2015-03-01

Ion beams supplied by the 3MV Tandem accelerator of LABEC laboratory (INFN-Firenze), have been used to study the feasibility of irradiating materials with ion fluences reproducible to about 1%. Test measurements have been made with 7.5 MeV 7Li2+ beams of different intensities. The fluence control is based on counting ions contained in short bursts generated by chopping the continuous beam with an electrostatic deflector followed by a couple of adjustable slits. Ions are counted by means of a micro-channel plate (MCP) detecting the electrons emitted from a thin layer of Al inserted along the beam path in between the pulse defining slits and the target. Calibration of the MCP electron detector is obtained by comparison with the response of a Si detector.

An optrode for photometric detection of ammonia in air

NASA Astrophysics Data System (ADS)

Buzanovskii, V. A.

2017-10-01

A scheme of constructing an LED optrode for photometric detection of ammonia in air is considered. The components of the device are (1) a glass plate coated with a film of polydimethylsiloxane with an ion-coupled cation of brilliant-green dye, (2) an LED emitting at a wavelength of 655 nm, and (3) a metal housing. The nominal static conversion function, sensitivity, and relative measurement error of the device are analyzed on the basis of mathematical modeling. The obtained results allow one to design an LED optrode capable of carrying out control for automated technological processes, solving problems in the area of security, etc. The device provides the ability to create photometric gas analyzers of ammonia with small overall dimensions, power consumption, and cost.

Investigation to develop a method to apply diffusion barrier to high strength fibers

NASA Technical Reports Server (NTRS)

Veltri, R. D.; Paradis, R. D.; Douglas, F. C.

1975-01-01

A radio frequency powered ion plating process was used to apply the diffusion barriers of aluminum oxide, yttrium oxide, hafnium oxide and titanium carbide to a substrate tungsten fiber. Each of the coatings was examined as to its effect on both room temperature strength and tensile strength of the base tungsten fiber. The coated fibers were then overcoated with a nickel alloy to become single cell diffusion couples. These diffusion couples were exposed to 1093 C for 24 hours, cycled between room temperature and 1093 C, and given a thermal anneal for 100 hours at 1200 C. Tensile testing and metallographic examinations determined that the hafnium oxide coating produced the best high temperature diffusion barrier for tungsten of the four coatings.

Chloride ion-driven transformation from Ag3PO4 to AgCl on the hydroxyapatite support and its dual antibacterial effect against Escherichia coli under visible light irradiation.

PubMed

Hong, Xiaoting; Li, Min; Shan, Shengdao; Hui, K S; Mo, Mingyue; Yuan, Xiaoli

2016-07-01

Visible light-driven photocatalytic inactivation of Escherichia coli was performed using hydroxyapatite-supported Ag3PO4 nanocomposites (Ag3PO4/HA). The antibacterial performance was evaluated by the methods of zone of inhibition plates and minimum inhibitory concentration test. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were employed to investigate the instability and transformation of the nanocomposite by comparing the crystalline, phase, and the morphology before and after exposure to Luria-Bertani culture medium under visible light irradiation. Ag3PO4 nanoparticles on the support were found to be shortly transformed into AgCl due to high chloride concentration of Luria-Bertani culture medium. The AgCl/HA nanocomposite showed both excellent intrinsic antibacterial performance contributed by the released silver ions and visible light-induced photocatalytic disinfection toward E. coli cells. This dual antibacterial function mechanism was validated by trapping the hydroxyl free radical and detecting the silver ions during the photocatalytic antibacterial process. The morphological change of E. coli cells in different reaction intervals was obtained by scanning electron microscopy (SEM) to complementally verify photocatalytic inactivation of E. coli. This work suggests that an essential comparison study is required for the antibacterial materials before and after the photocatalytic inactivation of bacterial cells using Ag3PO4 nanoparticles or Ag3PO4-related nanocomposites in mediums containing high-concentration chloride ions.

Identification of an interstellar oxide grain from the Murchison meteorite by ion imaging

NASA Technical Reports Server (NTRS)

Nittler, L. R.; Walker, R. M.; Zinner, E.; Hoppe, P.; Lewis, R. S.

1993-01-01

We report here the first use of a new ion-imaging system to locate a rare interstellar aluminum oxide grain in a Murchison acid residue. While several types of carbon-rich interstellar grains, including graphite, diamond, SiC, and TiC, have previously been found, isotopically anomalous interstellar oxide grains have proven more elusive. We have developed an ion imaging system which allows us to map the isotopic composition of large numbers of grains relatively quickly and is, thus, ideally suited to search for isotopically exotic subsets of grains. The system consists of a PHOTOMETRICS CCD camera coupled to the microchannel plate/fluorescent screen of the WU modified CAMECA IMS-3F ion microprobe. Isotopic images of the sample surface are focused on the CCD and digitized. Subsequent image processing identifies individual grains in the images and determines isotopic ratios for each. For the present work, we have imaged in O-16 and O-18; negligible contributions of (17)OH(-) and (16)OH2(-) signals to the O-18 signal allow the use of low mass resolution, simplifying the measurements. Repeated imaging runs on terrestrial corundum particles showed that the system measures isotopic ratios reproducibly to about +/- 40%. Each imaging run took about six minutes to complete, and for this study there were on average 5-15 grains in each image. We have conducted imaging searches in 2-4 micron size separates of both Orgueil and Murchison.

Barrel organ of plate tectonics - a new tool for outreach and education

NASA Astrophysics Data System (ADS)

Broz, Petr; Machek, Matěj; Šorm, Zdar

2016-04-01

Plate tectonics is the major geological concept to explain dynamics and structure of Earth's outer shell, the lithosphere. In the plate tectonic theory processes in the Earth lithosphere and its dynamics is driven by the relative motion and interaction of lithospheric plates. Geologically most active regions on Earth often correlate with the lithospheric plate boundaries. Thus for explaining the earth surface evolution, mountain building, volcanism and earthquake origin it is important to understand processes at the plate boundaries. However these processes associated with plate tectonics usually require significant period of time to take effects, therefore, their entire cycles cannot be directly observed in the nature by humans. This makes a challenge for scientists studying these processes, but also for teachers and popularizers trying to explain them to students and to the general public. Therefore, to overcome this problem, we developed a mechanical model of plate tectonics enabling demonstration of most important processes associated with plate tectonics in real time. The mechanical model is a wooden box, more specifically a special type of barrel organ, with hand painted backdrops in the front side. These backdrops are divided into several components representing geodynamic processes associated with plate tectonics, specifically convective currents occurring in the mantle, sea-floor spreading, a subduction of the oceanic crust under the continental crust, partial melting and volcanism associated with subduction, a formation of magmatic stripes, an ascent of mantle plume throughout the mantle, a volcanic activity associated with hot spots, and a formation and degradation of volcanic islands on moving lithospheric plate. All components are set in motion by a handle controlled by a human operator, and the scene is illuminated with colored lights controlled automatically by an electric device embedded in the box. Operation of the model may be seen on www.geologyinexperiments.com where additional pictures and details about the construction are available. This mechanical model represents a unique outreach tool how to present processes, normally taking eons to occur, to students and to the public in easy and funny way, and how to attract their attention to the most important concept in geology.

Development and testing of a pulsed helium ion source for probing materials and warm dense matter studies

NASA Astrophysics Data System (ADS)

Ji, Q.; Seidl, P. A.; Waldron, W. L.; Takakuwa, J. H.; Friedman, A.; Grote, D. P.; Persaud, A.; Barnard, J. J.; Schenkel, T.

2016-02-01

The neutralized drift compression experiment was designed and commissioned as a pulsed, linear induction accelerator to drive thin targets to warm dense matter (WDM) states with peak temperatures of ˜1 eV using intense, short pulses (˜1 ns) of 1.2 MeV lithium ions. At that kinetic energy, heating a thin target foil near the Bragg peak energy using He+ ions leads to more uniform energy deposition of the target material than Li+ ions. Experiments show that a higher current density of helium ions can be delivered from a plasma source compared to Li+ ions from a hot plate type ion source. He+ beam pulses as high as 200 mA at the peak and 4 μs long were measured from a multi-aperture 7-cm-diameter emission area. Within ±5% variation, the uniform beam area is approximately 6 cm across. The accelerated and compressed pulsed ion beams can be used for materials studies and isochoric heating of target materials for high energy density physics experiments and WDM studies.

Development and testing of a pulsed helium ion source for probing materials and warm dense matter studies.

PubMed

Ji, Q; Seidl, P A; Waldron, W L; Takakuwa, J H; Friedman, A; Grote, D P; Persaud, A; Barnard, J J; Schenkel, T

2016-02-01

The neutralized drift compression experiment was designed and commissioned as a pulsed, linear induction accelerator to drive thin targets to warm dense matter (WDM) states with peak temperatures of ∼1 eV using intense, short pulses (∼1 ns) of 1.2 MeV lithium ions. At that kinetic energy, heating a thin target foil near the Bragg peak energy using He(+) ions leads to more uniform energy deposition of the target material than Li(+) ions. Experiments show that a higher current density of helium ions can be delivered from a plasma source compared to Li(+) ions from a hot plate type ion source. He(+) beam pulses as high as 200 mA at the peak and 4 μs long were measured from a multi-aperture 7-cm-diameter emission area. Within ±5% variation, the uniform beam area is approximately 6 cm across. The accelerated and compressed pulsed ion beams can be used for materials studies and isochoric heating of target materials for high energy density physics experiments and WDM studies.

Development and testing of a pulsed helium ion source for probing materials and warm dense matter studies

DOE PAGES

Ji, Q.; Seidl, P. A.; Waldron, W. L.; ...

2015-11-12

In this paper, the neutralized drift compression experiment was designed and commissioned as a pulsed, linear induction accelerator to drive thin targets to warm dense matter (WDM) states with peak temperatures of ~1 eV using intense, short pulses (~1 ns) of 1.2 MeV lithium ions. At that kinetic energy, heating a thin target foil near the Bragg peak energy using He + ions leads to more uniform energy deposition of the target material than Li + ions. Experiments show that a higher current density of helium ions can be delivered from a plasma source compared to Li + ions frommore » a hot plate type ion source. He + beam pulses as high as 200 mA at the peak and 4 μs long were measured from a multi-aperture 7-cm-diameter emission area. Within ±5% variation, the uniform beam area is approximately 6 cm across. Finally, the accelerated and compressed pulsed ion beams can be used for materials studies and isochoric heating of target materials for high energy density physics experiments and WDM studies.« less

High efficiency ion beam accelerator system

NASA Technical Reports Server (NTRS)

Aston, G.

1981-01-01

An ion accelerator system that successfully combines geometrical and electrostatic focusing principles is presented. This accelerator system uses thin, concave, multiple-hole, closely spaced graphite screen and focusing grids which are coupled to single slot accelerator and decelerator grids to provide high ion extraction efficiency and good focusing. Tests with the system showed a substantial improvement in ion beam current density and collimation as compared with a Pierce electrode configuration. Durability of the thin graphite screen and focusing grids has been proven, and tests are being performed to determine the minimum screen and focusing grid spacing and thickness required to extract the maximum reliable beam current density. Compared with present neutral beam injector accelerator systems, this one has more efficient ion extraction, easier grid alignment, easier fabrication, a less cumbersome design, and the capacity to be constructed in a modular fashion. Conceptual neutral beam injector designs using this modular approach have electrostatic beam deflection plates downstream of each module.

Anomalous cation diffusion in salt-doped confined bilayer ice.

PubMed

Qiu, Hu; Xue, Minmin; Shen, Chun; Guo, Wanlin

2018-05-17

The diffusive dynamics of aqueous electrolyte solutions in nanoconfined spaces has attracted considerable attention due to their potential applications in desalination, biosensors and supercapacitors. Here we show by molecular dynamics simulations that lithium and sodium ions diffuse at a rate at least an order of magnitude higher than that of water molecules when the ions are trapped in an ice bilayer confined between two parallel plates. This novel picture is in sharp contrast to the prevailing view that the diffusion rate of ions is comparable to or even lower than that of water in both bulk and confined solutions. The predicted high ion mobility stems from frequent lateral hopping of ions along the coordination sites inside the hydrogen-bonding network connecting the two water layers of the ice bilayer. This anomalous diffusion should provide new insights into the physics of confined aqueous electrolytes.

Ion Acceleration by Double Layers with Multi-Component Ion Species

NASA Astrophysics Data System (ADS)

Good, Timothy; Aguirre, Evan; Scime, Earl; West Virginia University Team

2017-10-01

Current-free double layers (CFDL) models have been proposed to explain observations of magnetic field-aligned ion acceleration in plasmas expanding into divergent magnetic field regions. More recently, experimental studies of the Bohm sheath criterion in multiple ion species plasma reveal an equilibration of Bohm speeds at the sheath-presheath boundary for a grounded plate in a multipole-confined filament discharge. We aim to test this ion velocity effect for CFDL acceleration. We report high resolution ion velocity distribution function (IVDF) measurements using laser induced fluorescence downstream of a CFDL in a helicon plasma. Combinations of argon-helium, argon-krypton, and argon-xenon gases are ionized and measurements of argon or xenon IVDFs are investigated to determine whether ion acceleration is enhanced (or diminished) by the presence of lighter (or heavier) ions in the mix. We find that the predominant effect is a reduction of ion acceleration consistent with increased drag arising from increased gas pressure under all conditions, including constant total gas pressure, equal plasma densities of different ions, and very different plasma densities of different ions. These results suggest that the physics responsible for acceleration of multiple ion species in simple sheaths is not responsible for the ion acceleration observed in these expanding plasmas. Department of Physics, Gettysburg College.

Laser properties of Fe2+:ZnSe fabricated by solid-state diffusion bonding

NASA Astrophysics Data System (ADS)

Balabanov, S. S.; Firsov, K. N.; Gavrishchuk, E. M.; Ikonnikov, V. B.; Kazantsev, S. Yu; Kononov, I. G.; Kotereva, T. V.; Savin, D. V.; Timofeeva, N. A.

2018-04-01

The characteristics of an Fe2+:ZnSe laser at room temperature and its active elements with undoped faces were studied. Polycrystalline elements with one or two diffusion-doped internal layers were obtained by the solid-state diffusion bonding technique applied to chemical vapor deposition grown ZnSe plates preliminary doped with Fe2+ ions in the process of hot isostatic pressing. A non-chain electric-discharge HF laser was used to pump the crystals. It was demonstrated that increasing the number of doped layers allows increasing the maximum diameter of the pump radiation spot and the pump energy without the appearance of transversal parasitic oscillation. For the two-layer-doped active element with a diameter of 20 mm an output energy of 480 mJ was achieved with 37% total efficiency with respect to the absorbed energy. The obtained results demonstrate the potential of the developed technology for fabrication of active elements by the solid-state diffusion bonding technique combined with the hot isostatic pressing treatment for efficient IR lasers based on chalcogenides doped with transition metal ions.

Matrix-free mass spectrometric imaging using laser desorption ionisation Fourier transform ion cyclotron resonance mass spectrometry

PubMed Central

Goodwin, Richard J A; Pitt, Andrew R; Harrison, David; Weidt, Stefan K; Langridge-Smith, Pat R R; Barrett, Michael P; Logan Mackay, C

2011-01-01

Mass spectrometry imaging (MSI) is a powerful tool in metabolomics and proteomics for the spatial localization and identification of pharmaceuticals, metabolites, lipids, peptides and proteins in biological tissues. However, sample preparation remains a crucial variable in obtaining the most accurate distributions. Common washing steps used to remove salts, and solvent-based matrix application, allow analyte spreading to occur. Solvent-free matrix applications can reduce this risk, but increase the possibility of ionisation bias due to matrix adhesion to tissue sections. We report here the use of matrix-free MSI using laser desorption ionisation performed on a 12 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. We used unprocessed tissue with no post-processing following thaw-mounting on matrix-assisted laser desorption ionisation (MALDI) indium-tin oxide (ITO) target plates. The identification and distribution of a range of phospholipids in mouse brain and kidney sections are presented and compared with previously published MALDI time-of-flight (TOF) MSI distributions. Copyright © 2011 John Wiley & Sons, Ltd. PMID:21416534

Microcharge neutralization transport experiments and simulations for ion-driven inertial confinement fusion

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

Olson, C.L.; Hanson, D.L.; Poukey, J.W.

Space charge neutralization for intense beams for inertial confinement fusion is usually assumed to be perfect. However, small charge clumps in the beam will not be totally charge neutralized, and the residual net minimum potential set by electron trapping (e{phi} {approx} {1/2}m{sub e}v{sup 2}{sub i}, where m{sub e} is the electron mass and v{sub i} is the ion velocity) may lead to a substantial microdivergence. Experiments on the SABRE accelerator and simulations with the IPROP computer code are being performed to assess this mechanism. The authors have successfully created a 5 mrad beam on the SABRE accelerator, by expanding themore » beam (a process consistent with Liouville`s theorem) and, by passing the beam through a plate with pinholes, they have created low divergence beamlets to study this mechanism. Results clearly show: (1) at low pressures, trapping does neutralize the beamlets, but only down to e{phi} {approx} {1/2}m{sub e}v{sup 2}{sub i}; and (2) at higher pressures ({approx} 0.1-1 Torr), plasma shielding does remove the effect.« less

Effects of ionic surfactants on the morphology of silver nanoparticles using Paan (Piper betel) leaf petiole extract.

PubMed

Khan, Zaheer; Bashir, Ommer; Hussain, Javed Ijaz; Kumar, Sunil; Ahmad, Rabia

2012-10-01

Stable silver nanoparticles were synthesized by the reduction of silver ions with a Paan (Piper betel) leaf petiole extract in absence and presence of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS). The reaction process was simple and convenient to handle, and was monitored using ultraviolet-visible spectroscopy. Absorbance of Ag-nanoparticles increases with the concentrations of Paan leaf extract, acts as reducing, stabilizing and capping agents. The polyphenolic groups of petiole extract are responsible to the rapid reduction of Ag(+) ions into metallic Ag(0). The results indicated that the shape of the spectra, number of peaks and its position strongly depend on the concentration of CTAB, which played a shape-controlling role during the formation of silver nanoparticles in the solutions, whereas SDS has no significant effect. The morphology (spherical, truncated triangular polyhedral plate and some irregular nanoparticles) and crystalline phase of the particles were determined from transmission electron microscopy (TEM) and selected area electron diffraction (SAED). Copyright © 2012 Elsevier B.V. All rights reserved.

Review: Observations of recent comets, ion tails

NASA Technical Reports Server (NTRS)

Brandt, J. C.

1976-01-01

Photographic plates of the moving structures in the cometary tail are examined. Several divergent explanations for the case of comet Kohoutek are presented. It is suggested that these hypotheses be tested by observing the motion of the material spectroscopically by means of the Doppler effect.

Improving halide-containing magnesium-ion electrolyte performance via sterically hindered alkoxide ligands

NASA Astrophysics Data System (ADS)

Nist-Lund, Carl A.; Herb, Jake T.; Arnold, Craig B.

2017-09-01

While homoleptic magnesium dialkoxides (MgR2, R = alkoxide) have shown promise as precursors for magnesium-ion electrolytes, the effect of ligand steric bulk on the performance of electrolytes based on these compounds is not fully understood. Increasing steric hindrance, studied via R groups with additional phenyl moieties, produces electrolytes with sequentially lower deposition overpotentials (less than -90 mV), higher purity Mg deposits (ca. 100% Mg), and lower overall cell impedances. The two largest alkoxide ligands show consistent cycling behavior and low stripping and plating overpotentials over 200 constant-current plating/stripping cycles. A deep-red visual change and the presence of large solubilized magnesium particulates above 450 nm in size is observed in an electrolyte containing magnesium bis(triphenylmethoxide) and aluminum chloride in contact with an abraded magnesium anode. Further morphological and impedance characterization show that this electrolyte system rapidly activates the magnesium metal anode surface to produce low overpotentials and, as such, is a candidate for further investigation.

A study for the installation of the TEXT heavy-ion beam probe on DIII-D

NASA Astrophysics Data System (ADS)

Edmonds, P. H.; Solano, E. R.; Bravenec, R. V.; Wootton, A. J.; Schoch, P. M.; Crowley, T. P.; Hickok, R. L.; West, W. P.; Leuer, J.; Anderson, P.

1997-01-01

An assessment of the feasibility of installing the TEXT 2 MeV heavy-ion beam probe on the DIII-D tokamak has been completed. Detailed drawings of the machine cross section were imported into the CAD application AutoCAD. A set of programs written in AutoLisp were used to generate trajectories. Displays of the accessible cross section of the plasma, scan lines for the entire range of primary beam energy and injection angle ranges, and sample-volume dimensions can be rapidly generated. Because of the large deflection between the primary input beam and the emergent secondary beam, either the analyzer needs to be tracked over a ±20° angle or secondary poloidal deflector plates need to be installed at the exit port. Toroidal deflector plates will be installed at both the injection and exit ports to compensate for toroidal displacements and deflections. The sample volumes generated by this procedure are within a few centimeters of the locations derived from a full three-dimensional calculation.

Dustbuster: a New Generation Impact-ionization Time-of-flight Mass Spectrometer for in situ Analysis of Cosmic Dust

NASA Astrophysics Data System (ADS)

Austin, D. E.; Ahrens, T. J.; Beauchamp, J. L.

2000-10-01

We have developed and tested a small impact-ionization time-of-flight mass spectrometer for analysis of cosmic dust, suitable for use on deep space missions. This mass spectrometer, named Dustbuster, incorporates a large target area and a reflectron, simultaneously optimizing mass resolution, sensitivity, and collection efficiency. Dust particles hitting the 65-cm2 target plate are partially ionized. The resulting ions are accelerated through a modified reflectron that focuses the ions in space and time to produce high-resolution spectra. The instrument, shown below, measures 10 x 10 x 20 cm, has a mass of 500 g, and consumes little power. Laser desorption ionization of metal and mineral samples (embedded in the impact plate) simulates particle impacts for instrument performance tests. Mass resolution in these experiments is near 200, permitting resolution of isotopes. The mass spectrometer can be combined with other instrument components to determine dust particle trajectories and sizes. This project was funded by NASA's Planetary Instrument Definition and Development Program.

THE ENZYMATIC RESPONSE OF ASTROCYTES TO VARIOUS IONS IN VITRO

PubMed Central

Friede, Reinhard L.

1964-01-01

The effect of environmental ion concentration on the enzyme activity of astrocytes was investigated in tissue cultures of rat cerebral cortex. It was found that the oxidative enzymatic activity (succinic dehydrogenase, DPN-diaphorase, and several other enzymes) of astrocytes depended on the concentration of NaCl in the environment. This response was not specific for NaCl, but was also elicited by MgCl2 and LiCl; the response was less consistent, and often questionable for KCl. However, only NaCl could elicit enzymatic changes in astrocytes at concentrations known to be present in a living organism. Astrocytes were the only cells which responded this way; it appeared that the foot-plates were particularly involved in the response since increase of enzyme activity occurred earlier in the foot-plates than in the perikarya. It was concluded that astrocytes are metabolically involved in the maintenance of the ionic and osmotic environment of the central nervous system, particularly in regard to the active transport of sodium. PMID:14105217

Testing of multigap Resistive Plate Chambers for Electron Ion Collider Detector Development

NASA Astrophysics Data System (ADS)

Hamilton, Hannah; Phenix Collaboration

2015-10-01

Despite decades of research on the subject, some details of the spin structure of the nucleon continues to be unknown. To improve our knowledge of the nucleon spin structure, the construction of a new collider is needed. This is one of the primary goals of the proposed Electron Ion Collider (EIC). Planned EIC spectrometers will require good particle identification. This can be provided by time of flight (TOF) detectors with excellent timing resolutions of 10 ps. A potential TOF detector that could meet this requirement is a glass multigap resistive plate chamber (mRPC). These mRPCs can provide excellent timing resolution at a low cost. The current glass mRPC prototypes have a total of twenty 0.1 mm thick gas gaps. In order to test the feasibility of this design, a cosmic test stand was assembled. This stand used the coincidence of scintillators as a trigger, and contains fast electronics. The construction, the method of testing, and the test results of the mRPCs will be presented.

Highly conductive thermoplastic composites for rapid production of fuel cell bipolar plates

DOEpatents

Huang, Jianhua [Blacksburg, VA; Baird, Donald G [Blacksburg, VA; McGrath, James E [Blacksburg, VA

2008-04-29

A low cost method of fabricating bipolar plates for use in fuel cells utilizes a wet lay process for combining graphite particles, thermoplastic fibers, and reinforcing fibers to produce a plurality of formable sheets. The formable sheets are then molded into a bipolar plates with features impressed therein via the molding process. The bipolar plates formed by the process have conductivity in excess of 150 S/cm and have sufficient mechanical strength to be used in fuel cells. The bipolar plates can be formed as a skin/core laminate where a second polymer material is used on the skin surface which provides for enhanced conductivity, chemical resistance, and resistance to gas permeation.

Plates for vacuum thermal fusion

DOEpatents

Davidson, James C.; Balch, Joseph W.

2002-01-01

A process for effectively bonding arbitrary size or shape substrates. The process incorporates vacuum pull down techniques to ensure uniform surface contact during the bonding process. The essence of the process for bonding substrates, such as glass, plastic, or alloys, etc., which have a moderate melting point with a gradual softening point curve, involves the application of an active vacuum source to evacuate interstices between the substrates while at the same time providing a positive force to hold the parts to be bonded in contact. This enables increasing the temperature of the bonding process to ensure that the softening point has been reached and small void areas are filled and come in contact with the opposing substrate. The process is most effective where at least one of the two plates or substrates contain channels or grooves that can be used to apply vacuum between the plates or substrates during the thermal bonding cycle. Also, it is beneficial to provide a vacuum groove or channel near the perimeter of the plates or substrates to ensure bonding of the perimeter of the plates or substrates and reduce the unbonded regions inside the interior region of the plates or substrates.

Effect of bioparticle size on dispersion and retention in monolithic and perfusive beds

PubMed Central

Trilisky, Egor I.; Lenhoff, Abraham M.

2010-01-01

Single-component pulse response studies were used to compare the retention and transport behavior of small molecules, proteins, and a virus on commercially available monolithic and perfusive ion-exchangers. Temporal distortion and extra-column effects were corrected for using a simple algorithm based on the method of moments. It was found that temporal distortion is inversely related to the number of theoretical plates. With increasing bioparticle size, retention increased and the transition from a non-eluting to a non-adsorbing state with increasing ionic strength became more abrupt. Both of these observations are qualitatively explained by calculations of particle-surface electrostatic attractive energy. Calculations also show that, for sufficiently large bioparticles, such as viruses or cells, hydrodynamic drag can promote elution. Under non-adsorbing conditions, plate height increased only weakly with flow rate and the skew remained unchanged. With increasing retention, plate height increased dramatically for proteins. Plate height was scaled by permeability rather than bead diameter to enable comparison among different stationary phases. PMID:20951383

APPARATUS FOR THE MASS ANALYSIS OF PLASMA ON A CONTINUOUS BASIS

DOEpatents

Neidigh, R.V.

1963-07-01

An apparatus for the mass analysis of plasmas on a continuous basis is described. The apparatus comprises a pair of parallel electrodes in a tubular member which serve as a velocity-selecting region for ions drawn by an accelerating potential through a tapered nose cone affixed to the tubular member. The magnetic force and electrostatic forces in the velocity-selecting region are made equal and opposite in direction to prevent the ionic species from striking either of the electrodes as they traverse the region. A pair of parallel plates is positioned within the tubular member and in alignment with the electrodes, but displaced slightly so as not to be seen by direct light coming through the entrance slit of the nose cone, and one of these plates serves as a collector plate. This collector plate is coupled to the vertical amplifier of an oscilloscope or other recorder to provide a continuous indication of the ionic coinposition of the plasma under analysis. ( DELTA EC)

TimepixCam: a fast optical imager with time-stamping

NASA Astrophysics Data System (ADS)

Fisher-Levine, M.; Nomerotski, A.

2016-03-01

We describe a novel fast optical imager, TimepixCam, based on an optimized silicon pixel sensor with a thin entrance window, read out by a Timepix ASIC. TimepixCam is able to record and time-stamp light flashes in excess of 1,000 photons with high quantum efficiency in the 400-1000nm wavelength range with 20ns timing resolution, corresponding to an effective rate of 50 Megaframes per second. The camera was used for imaging ions impinging on a microchannel plate followed by a phosphor screen. Possible applications include spatial and velocity map imaging of ions in time-of-flight mass spectroscopy; coincidence imaging of ions and electrons, and other time-resolved types of imaging spectroscopy.

Design and Fabrication of Quadrupole Ion Mass Spectrometer for Upper Atmosphere.

DTIC Science & Technology

1981-09-30

34 diameter con-flat flange were T.I.G. welded to the end of each of three bowls. All bowls were then electro- polished, cleaned and sent out to have...plated surface was .0001" to .0002" thick. After gold plating, the hemispheres were mated and T.I.G. welded to form a sphere with a con-flat flange at...Valve Rotatable Conflat to fit k" Swage Lock Weld Adaptors. 5 2 3/4" Conflat Flanges machined to fit Swage Lock unions. 12 10-24 x 2 " Brass Screws necket

Ion channel pharmacology under flow: automation via well-plate microfluidics.

PubMed

Spencer, C Ian; Li, Nianzhen; Chen, Qin; Johnson, Juliette; Nevill, Tanner; Kammonen, Juha; Ionescu-Zanetti, Cristian

2012-08-01

Automated patch clamping addresses the need for high-throughput screening of chemical entities that alter ion channel function. As a result, there is considerable utility in the pharmaceutical screening arena for novel platforms that can produce relevant data both rapidly and consistently. Here we present results that were obtained with an innovative microfluidic automated patch clamp system utilizing a well-plate that eliminates the necessity of internal robotic liquid handling. Continuous recording from cell ensembles, rapid solution switching, and a bench-top footprint enable a number of assay formats previously inaccessible to automated systems. An electro-pneumatic interface was employed to drive the laminar flow of solutions in a microfluidic network that delivered cells in suspension to ensemble recording sites. Whole-cell voltage clamp was applied to linear arrays of 20 cells in parallel utilizing a 64-channel voltage clamp amplifier. A number of unique assays requiring sequential compound applications separated by a second or less, such as rapid determination of the agonist EC(50) for a ligand-gated ion channel or the kinetics of desensitization recovery, are enabled by the system. In addition, the system was validated via electrophysiological characterizations of both voltage-gated and ligand-gated ion channel targets: hK(V)2.1 and human Ether-à-go-go-related gene potassium channels, hNa(V)1.7 and 1.8 sodium channels, and (α1) hGABA(A) and (α1) human nicotinic acetylcholine receptor receptors. Our results show that the voltage dependence, kinetics, and interactions of these channels with pharmacological agents were matched to reference data. The results from these IonFlux™ experiments demonstrate that the system provides high-throughput automated electrophysiology with enhanced reliability and consistency, in a user-friendly format.

Rapid prototyping of Fresnel zone plates via direct Ga(+) ion beam lithography for high-resolution X-ray imaging.

PubMed

Keskinbora, Kahraman; Grévent, Corinne; Eigenthaler, Ulrike; Weigand, Markus; Schütz, Gisela

2013-11-26

A significant challenge to the wide utilization of X-ray microscopy lies in the difficulty in fabricating adequate high-resolution optics. To date, electron beam lithography has been the dominant technique for the fabrication of diffractive focusing optics called Fresnel zone plates (FZP), even though this preparation method is usually very complicated and is composed of many fabrication steps. In this work, we demonstrate an alternative method that allows the direct, simple, and fast fabrication of FZPs using focused Ga(+) beam lithography practically, in a single step. This method enabled us to prepare a high-resolution FZP in less than 13 min. The performance of the FZP was evaluated in a scanning transmission soft X-ray microscope where nanostructures as small as sub-29 nm in width were clearly resolved, with an ultimate cutoff resolution of 24.25 nm, demonstrating the highest first-order resolution for any FZP fabricated by the ion beam lithography technique. This rapid and simple fabrication scheme illustrates the capabilities and the potential of direct ion beam lithography (IBL) and is expected to increase the accessibility of high-resolution optics to a wider community of researchers working on soft X-ray and extreme ultraviolet microscopy using synchrotron radiation and advanced laboratory sources.

Global redox cycle of biospheric carbon: Interaction of photosynthesis and earth crust processes.

PubMed

Ivlev, Alexander A

2015-11-01

A model of the natural global redox cycle of biospheric carbon is introduced. According to this model, carbon transfer between biosphere and geospheres is accompanied by a conversion of the oxidative forms, presented by CO2, bicarbonate and carbonate ions, into the reduced forms, produced in photosynthesis. The mechanism of carbon transfer is associated with two phases of movement of lithospheric plates. In the short-term orogenic phase, CO2 from the subduction (plates' collisions) zones fills the "atmosphere-hydrosphere" system, resulting in climate warming. In the long-term quiet (geosynclynal) phase, weathering and photosynthesis become dominant depleting the oxidative forms of carbon. The above asymmetric periodicity exerts an impact on climate, biodiversity, distribution of organic matter in sedimentary deposits, etc. Along with photosynthesis expansion, the redox carbon cycle undergoes its development until it reaches the ecological compensation point, at which CO2 is depleted to the level critical to support the growth and reproduction of plants. This occurred in the Permo-Carboniferous time and in the Neogene. Shorter-term perturbations of the global carbon cycle in the form of glacial-interglacial oscillations appear near the ecological compensation point. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A model of convergent plate margins based on the recent tectonics of Shikoku, Japan

NASA Technical Reports Server (NTRS)

Bischke, R. E.

1974-01-01

A viscoelastic finite element plate tectonic model is applied to displacement data for the island of Shikoku, Japan. The flow properties and geometry of the upper portions of the earth are assumed known from geophysical evidence, and the loading characteristics are determined from the model. The nature of the forces acting on the Philippine Sea plate, particularly in the vicinity of the Nankai trough, is determined. Seismic displacement data related to the 1946 Nankaido earthquake are modeled in terms of a thick elastic plate overlying a fluidlike substratum. The sequence of preseismic and seismic displacements can be explained in terms of two independent processes operating on elastic lithospheric plates: a strain accumulation process caused by vertical downward forces acting on or within the lithosphere in the vicinity of the trench, and a strain release process caused by plate failure along a preexisting zone on weakness. This is a restatement of Reid's elastic rebound theory in terms of elastic lithospheric plates.

PROCESS FOR MAKING NEUTRON-ABSORBING BODIES

DOEpatents

Schippereit, G.H.; Lang, R.M.

1961-11-14

A process for making a control element for a nuclear reactor and the control element prepared by the process are described. Equally spaced, conically shaped depressions are formed in one face of a metal plate, spheres of boron of uniform size are placed in the depressions, another plate is welded on top of this place covering the depressions, and the joined plates are rolled to the desired thickness. (AEC)

Oxygen ion implantation induced microstructural changes and electrical conductivity in Bakelite RPC detector material

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

Kumar, K. V. Aneesh, E-mail: aneesh1098@gmail.com; Ravikumar, H. B., E-mail: hbr@physics.uni-mysore.ac.in; Ranganathaiah, C., E-mail: cr@physics.uni-mysore.ac.in

2016-05-06

In order to explore the structural modification induced electrical conductivity, samples of Bakelite Resistive Plate Chamber (RPC) detector materials were exposed to 100 keV Oxygen ion in the fluences of 10{sup 12}, 10{sup 13}, 10{sup 14} and 10{sup 15} ions/cm{sup 2}. Ion implantation induced microstructural changes have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and X-Ray Diffraction (XRD) techniques. Positron lifetime parameters viz., o-Ps lifetime and its intensity shows the deposition of high energy interior track and chain scission leads to the formation of radicals, secondary ions and electrons at lower ion implantation fluences (10{sup 12} to10{sup 14} ions/cm{supmore » 2}) followed by cross-linking at 10{sup 15} ions/cm{sup 2} fluence due to the radical reactions. The reduction in electrical conductivity of Bakelite detector material is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate implantation energy and fluence of Oxygen ion on polymer based Bakelite RPC detector material may reduce the leakage current, improves the efficiency, time resolution and thereby rectify the aging crisis of the RPC detectors.« less

Using the Mesozoic History of the Canadian Cordillera as a Case Study in Teaching Plate Tectonics.

ERIC Educational Resources Information Center

Chamberlain, Valerie Elaine

1989-01-01

Reviews a model used in the teaching of plate tectonics which includes processes and concepts related to: terranes and the amalgamation of terranes, relative plate motion and oblique subduction, the effects of continent-continent collision, changes in plate motion, plate configuration, and the type of plate boundary. Diagrams are included.…

Silver plating ensures reliable diffusion bonding of dissimilar metals

NASA Technical Reports Server (NTRS)

1967-01-01

Dissimilar metals are reliably joined by diffusion bonding when the surfaces are electroplated with silver. The process involves cleaning and etching, anodization, silver striking, and silver plating with a conventional plating bath. It minimizes the formation of detrimental intermetallic phases and provides greater tolerance of processing parameters.

Embryonic Methamphetamine Exposure Inhibits Methamphetamine Cue Conditioning and Reduces Dopamine Concentrations in Adult N2 C. elegans

PubMed Central

Katner, S.N.; Neal-Beliveau, B.S.; Engleman, E.A.

2016-01-01

Methamphetamine (MAP) addiction is substantially prevalent in today's society, resulting in thousands of deaths and costing billions of dollars annually. Despite the potential deleterious consequences, few studies have examined the long-term effects of embryonic MAP exposure. Using the invertebrate nematode Caenorhabditis elegans (C. elegans) allows for a controlled analysis of behavioral and neurochemical changes due to early developmental drug exposure. The objective of the current studies was to determine the long-term behavioral and neurochemical effects of embryonic exposure to MAP in C. elegans. In addition, we sought to improve our conditioning and testing procedures by utilizing liquid filtration, as opposed to agar, and smaller, 6-well testing plates to increase throughput. Wild-type N2 C. elegans were embryonically exposed to 50 μM MAP. Using classical conditioning, adult-stage C. elegans were conditioned to MAP (17 and 500 μM) in the presence of either sodium ions (Na+) or chloride (Cl-) ions as conditioned stimuli (CS+/CS-). Following conditioning, a preference test was performed by placing worms in 6-well test plates spotted with the CS+ and CS- at opposite ends of each well. A preference index (PI) was determined by counting the number of worms in the CS+ target zone divided by the total number of worms in the CS+ and CS- target zones. A food conditioning experiment was also performed in order to determine if embryonic MAP exposure affected food conditioning behavior. For the neurochemical experiments, adult worms that were embryonically exposed to MAP were analyzed for (dopamine) DA content using high performance liquid chromatography (HPLC). The liquid filtration conditioning procedure employed here in combination with the use 6-well test plates significantly decreased the time required to perform these experiments and ultimately increased throughput. The MAP conditioning data found that pairing an ion with MAP at 17 or 500 μM significantly increased the preference for that ion (CS+) in worms that were not pre-exposed to MAP. However, worms embryonically exposed to MAP did not exhibit significant drug cue conditioning. The inability of MAP exposed worms to condition to MAP was not associated with deficits in food conditioning, as MAP exposed worms exhibited a significant cue preference associated with food. Furthermore, our results found that embryonic MAP exposure reduced DA levels in adult C. elegans, which could be a key mechanism contributing to the long-term effects of embryonic MAP exposure. It is possible that embryonic MAP exposure may be impairing the ability for C. elegans to learn associations between MAP and the CS+ or inhibiting the reinforcing properties of MAP, however, our food conditioning data suggest that MAP exposed animals can form associations between cues and food. The depletion of DA levels during embryonic exposure to MAP could be responsible for driving either of these processes during adulthood. PMID:27233671

Embryonic Methamphetamine Exposure Inhibits Methamphetamine Cue Conditioning and Reduces Dopamine Concentrations in Adult N2 Caenorhabditis elegans.

PubMed

Katner, Simon N; Neal-Beliveau, Bethany S; Engleman, Eric A

2016-01-01

Methamphetamine (MAP) addiction is substantially prevalent in today's society, resulting in thousands of deaths and costing billions of dollars annually. Despite the potential deleterious consequences, few studies have examined the long-term effects of embryonic MAP exposure. Using the invertebrate nematode Caenorhabditis elegans allows for a controlled analysis of behavioral and neurochemical changes due to early developmental drug exposure. The objective of the current study was to determine the long-term behavioral and neurochemical effects of embryonic exposure to MAP in C. elegans. In addition, we sought to improve our conditioning and testing procedures by utilizing liquid filtration, as opposed to agar, and smaller, 6-well testing plates to increase throughput. Wild-type N2 C. elegans were embryonically exposed to 50 μM MAP. Using classical conditioning, adult-stage C. elegans were conditioned to MAP (17 and 500 μM) in the presence of either sodium ions (Na+) or chloride ions (Cl-) as conditioned stimuli (CS+/CS-). Following conditioning, a preference test was performed by placing worms in 6-well test plates spotted with the CS+ and CS- at opposite ends of each well. A preference index was determined by counting the number of worms in the CS+ target zone divided by the total number of worms in the CS+ and CS- target zones. A food conditioning experiment was also performed in order to determine whether embryonic MAP exposure affected food conditioning behavior. For the neurochemical experiments, adult worms that were embryonically exposed to MAP were analyzed for dopamine (DA) content using high-performance liquid chromatography. The liquid filtration conditioning procedure employed here in combination with the use of 6-well test plates significantly decreased the time required to perform these experiments and ultimately increased throughput. The MAP conditioning data found that pairing an ion with MAP at 17 or 500 μM significantly increased the preference for that ion (CS+) in worms that were not pre-exposed to MAP. However, worms embryonically exposed to MAP did not exhibit significant drug cue conditioning. The inability of MAP-exposed worms to condition to MAP was not associated with deficits in food conditioning, as MAP-exposed worms exhibited a significant cue preference associated with food. Furthermore, our results found that embryonic MAP exposure reduced DA levels in adult C. elegans, which could be a key mechanism contributing to the long-term effects of embryonic MAP exposure. It is possible that embryonic MAP exposure may be impairing the ability of C. elegans to learn associations between MAP and the CS+ or inhibiting the reinforcing properties of MAP. However, our food conditioning data suggest that MAP-exposed animals can form associations between cues and food. The depletion of DA levels during embryonic exposure to MAP could be responsible for driving either of these processes during adulthood. © 2016 S. Karger AG, Basel.

SAMI Automated Plug Plate Configuration

NASA Astrophysics Data System (ADS)

Lorente, N. P. F.; Farrell, T.; Goodwin, M.

2013-10-01

The Sydney-AAO Multi-object Integral field spectrograph (SAMI) is a prototype wide-field system at the Anglo-Australian Telescope (AAT) which uses a plug-plate to mount its 13×61-core imaging fibre bundles (hexabundles) in the optical path at the telescope's prime focus. In this paper we describe the process of determining the positions of the plug-plate holes, where plates contain three or more stacked observation configurations. The process, which up until now has involved several separate processes and has required significant manual configuration and checking, is now being automated to increase efficiency and reduce error. This is carried out by means of a thin Java controller layer which drives the configuration cycle. This layer controls the user interface and the C++ algorithm layer where the plate configuration and optimisation is carried out. Additionally, through the Aladin display package, it provides visualisation and facilitates user verification of the resulting plates.

Plasma/Wall interaction of an insulated material by laser-induced fluorescence diagnostic

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

Claire, N.; Doveil, F.

2015-07-01

We present Argon Ion Velocity Distribution Function (IVDF) in the vicinity of an insulated BNSiO{sub 2} ceramic and a glass plate in a non magnetized plasma by laser-induced fluorescence diagnostic. Results show the rather surprising self-consistent formation of a positive or inverse sheath in the two cases. The positive plasma potential repels ions from the insulated wall and is not explained by any sheath theory. Electron secondary emission of the ceramic can be a good candidate to explain these results. (authors)

OH radicals generated by DC corona discharge for improving the pulsed discharge desulfuration efficiency.

PubMed

Li, Jie; Li, Guo-feng; Wu, Yan; Wang, Ning-hui; Huang, Qiu-nan

2004-01-01

Positive DC corona discharge is formed with needle-plate electrode configuration, in which the water vapor is ejected though the needle points. The purpose is to increase the numbers of the water-based radicals, ionize the water molecule and improve the desulfuration efficiency of pulsed corona reactor. The water ions were determined by four stages molecular beam mass spectrometer and diagnose the water-based radicals by emission spectrograph. A conclusion on formation of ions and radicals with DC corona discharges can be drawn.

Ultra-high-mass mass spectrometry with charge discrimination using cryogenic detectors

DOEpatents

Frank, Matthias; Mears, Carl A.; Labov, Simon E.; Benner, W. Henry

1999-01-01

An ultra-high-mass time-of-flight mass spectrometer using a cryogenic particle detector as an ion detector with charge discriminating capabilities. Cryogenic detectors have the potential for significantly improving the performance and sensitivity of time-of-flight mass spectrometers, and compared to ion multipliers they exhibit superior sensitivity for high-mass, slow-moving macromolecular ions and can be used as "stop" detectors in time-of-flight applications. In addition, their energy resolving capability can be used to measure the charge state of the ions. Charge discrimination is very valuable in all time-of-flight mass spectrometers. Using a cryogenically-cooled Nb-Al.sub.2 O.sub.3 -Nb superconductor-insulator-superconductor (SIS) tunnel junction (STJ) detector operating at 1.3 K as an ion detector in a time-of-flight mass spectrometer for large biomolecules it was found that the STJ detector has charge discrimination capabilities. Since the cryogenic STJ detector responds to ion energy and does not rely on secondary electron production, as in the conventionally used microchannel plate (MCP) detectors, the cryogenic detector therefore detects large molecular ions with a velocity-independent efficiency approaching 100%.

A study of single and binary ion plasma expansion into laboratory-generated plasma wakes

NASA Technical Reports Server (NTRS)

Wright, Kenneth Herbert, Jr.

1988-01-01

Plasma expansion into the wake of a large rectangular plate immersed in a collisionless, supersonic plasma was investigated in laboratory experiments. The experimental conditions address both single ion and binary ion plasma flows for the case of a body whose size is large in comparison with the Debye length, when the potential difference between the body and the plasma is relatively small. A new plasma source was developed to generate equi-velocity, binary ion plasma flows, which allows access to new parameter space that have previously been unavailable for laboratory studies. Specifically, the new parameters are the ionic mass ratio and the ionic component density ratio. In a series of experiments, a krypton-neon plasma is employed where the ambient density ratio of neon to krypton is varied more than an order of magnitude. The expansion in both the single ion and binary ion plasma cases is limited to early times, i.e., a few ion plasma periods, by the combination of plasma density, plasma drift speed, and vacuum chamber size, which prevented detailed comparison with self-similar theory.

Measurement of ion density in an atmospheric pressure argon with pin-to-plate dielectric barrier discharge by resonance of plasma radiation

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

Qi, Bing, E-mail: qibing@szu.edu.cn; Pan, Lizhu; Zhou, Qiujiao

2014-12-15

The measurements of the ion densities in the atmospheric AC barrier corona argon discharge are carried out by receiving and analyzing the frequencies of the electromagnetic radiation emitted from the plasma. An auxiliary excitation source composed of a pin-to-pin discharge system is introduced to excite the oscillations of the main discharge. To analyze the resonance mechanism, a complemented model based on a one-dimensional description of forced vibrations is given. Calculations indicate that Ar{sub 2}{sup +} is the dominant ion (∼89% in number density). By analyzing resonance frequencies, the ion densities of Ar{sub 2}{sup +} are in the order of 10{supmore » 19}∼10{sup 20}m{sup −3} and increase slowly as the applied voltage increases.« less

The TFTR E Parallel B Spectrometer for Mass and Energy Resolved Multi-Ion Charge Exchange Diagnostics

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

A.L. Roquemore; S.S. Medley

1998-01-01

The Charge Exchange Neutral Analyzer diagnostic for the Tokamak Fusion Test Reactor was designed to measure the energy distributions of both the thermal ions and the supra thermal populations arising from neutral-beam injection and ion cyclotron radio-frequency heating. These measurements yield the plasma ion temperature, as well as several other plasma parameters necessary to provide an understanding of the plasma condition and the performance of the auxiliary heating methods. For this application, a novel charge-exchange spectrometer using a dee-shaped region of parallel electric and magnetic fields was developed at the Princeton Plasma Physics Laboratory. The design and performance of thismore » spectrometer is described in detail, including the effects of exposure of the microchannel plate detector to magnetic fields, neutrons, and tritium.« less

Modeling electrokinetics in ionic liquids: General

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

Wang, Chao; Bao, Jie; Pan, Wenxiao

2017-04-07

Using direct numerical simulations we provide a thorough study on the electrokinetics of ionic liquids. In particular, the modfied Poisson-Nernst-Planck (MPNP) equations are solved to capture the crowding and overscreening effects that are the characteristics of an ionic liquid. For modeling electrokinetic flows in an ionic liquid, the MPNP equations are coupled with the Navier-Stokes equations to study the coupling of ion transport, hydrodynamics, and electrostatic forces. Specifically, we consider the ion transport between two parallel plates, charging dynamics in a 2D straight-walled pore, electro-osmotic ow in a nano-channel, electroconvective instability on a plane ion-selective surface, and electroconvective ow onmore » a curved ion-selective surface. We discuss how the crowding and overscreening effects and their interplay affect the electrokinetic behaviors of ionic liquids in these application problems.« less

A High Sensitivity Micro Format Chemiluminescence Enzyme Inhibition Assay for Determination of Hg(II)

PubMed Central

Deshpande, Kanchanmala; Mishra, Rupesh K.; Bhand, Sunil

2010-01-01

A highly sensitive and specific enzyme inhibition assay based on alcohol oxidase (AlOx) and horseradish peroxidase (HRP) for determination of mercury Hg(II) in water samples has been presented. This article describes the optimization and miniaturization of an enzymatic assay using a chemiluminescence reaction. The analytical performance and detection limit for determination of Hg(II) was optimized in 96 well plates and further extended to 384 well plates with a 10-fold reduction in assay volume. Inhibition of the enzyme activity by dissolved Hg(II) was found to be linear in the range 5–500 pg·mL−1 with 3% CV in inter-batch assay. Due to miniaturization of assay in 384 well plates, Hg(II) was measurable as low as 1 pg·mL−1 within 15 min. About 10-fold more specificity of the developed assay for Hg(II) analysis was confirmed by challenging with interfering divalent metal ions such as cadmium Cd(II) and lead Pb(II). Using the proposed assay we could successfully demonstrate that in a composite mixture of Hg(II), Cd(II) and Pb(II), inhibition by each metal ion is significantly enhanced in the presence of the others. Applicability of the proposed assay for the determination of the Hg(II) in spiked drinking and sea water resulted in recoveries ranging from 100–110.52%. PMID:22163555

A comparison of field-dependent rheological properties between spherical and plate-like carbonyl iron particles-based magneto-rheological fluids

NASA Astrophysics Data System (ADS)

Tan Shilan, Salihah; Amri Mazlan, Saiful; Ido, Yasushi; Hajalilou, Abdollah; Jeyadevan, Balachandran; Choi, Seung-Bok; Azhani Yunus, Nurul

2016-09-01

This work proposes different sizes of the plate-like particles from conventional spherical carbonyl iron (CI) particles by adjusting milling time in the ball mill process. The ball mill process to make the plate-like particles is called a solid-state powder processing technique which involves repeated welding, fracturing and re-welding of powder particles in a high-energy ball mill. The effect of ball milling process on the magnetic behavior of CI particles is firstly investigated by vibrating sample magnetometer. It is found form this investigation that the plate-like particles have higher saturation magnetization (about 8%) than that of the spherical particles. Subsequently, for the investigation on the sedimentation behavior the cylindrical measurement technique is used. It is observed from this measurement that the plate-like particles show slower sedimentation rate compared to the spherical particles indicating higher stability of the MR fluid. The field-dependent rheological properties of MR fluids based on the plate-like particles are then investigated with respect to the milling time which is directly connected to the size of the plate-like particles. In addition, the field-dependent rheological properties such as the yield stress are evaluated and compared between the plate-like particles based MR fluids and the spherical particles based MR fluid. It is found that the yield shear stress of the plate-like particles based MR fluid is increased up to 270% compared to the spherical particles based MR fluid.

Investigation of plasma parameters at BATMAN for variation of the Cs evaporation asymmetry and comparing two driver geometries

NASA Astrophysics Data System (ADS)

Wimmer, C.; Fantz, U.; Aza, E.; Jovović, J.; Kraus, W.; Mimo, A.; Schiesko, L.

2017-08-01

The Neutral Beam Injection (NBI) system for fusion devices like ITER and, beyond ITER, DEMO requires large scale sources for negative hydrogen ions. BATMAN (Bavarian Test Machine for Negative ions) is a test facility attached with the prototype source for the ITER NBI (1/8 source size of the ITER source), dedicated to physical investigations due to its flexible access for diagnostics and exchange of source components. The required amount of negative ions is produced by surface conversion of hydrogen atoms or ions on caesiated surfaces. Several diagnostic tools (Optical Emission Spectroscopy, Cavity Ring-Down Spectroscopy for H-, Langmuir probes, Tunable Diode Laser Absorption Spectroscopy for Cs) allow the determination of plasma parameters in the ion source. Plasma parameters for two modifications of the standard prototype source have been investigated: Firstly, a second Cs oven has been installed in the bottom part of the back plate in addition to the regularly used oven in the top part of the back plate. Evaporation from the top oven only can lead to a vertically asymmetric Cs distribution in front of the plasma grid. Using both ovens, a symmetric Cs distribution can be reached - however, in most cases no significant change of the extracted ion current has been determined for varying Cs symmetry if the source is well-conditioned. Secondly, BATMAN has been equipped with a much larger, racetrack-shaped RF driver (area of 32×58 cm2) instead of the cylindrical RF driver (diameter of 24.5 cm). The main idea is that one racetrack driver could substitute two cylindrical drivers in larger sources with increased reliability and power efficiency. For the same applied RF power, the electron density is lower in the racetrack driver due to its five times higher volume. The fraction of hydrogen atoms to molecules, however, is at a similar level or even slightly higher, which is a promising result for application in larger sources.

Physics of heat pipe rewetting

NASA Technical Reports Server (NTRS)

Chan, S. H.

1992-01-01

Although several studies have been made to determine the rewetting characteristics of liquid films on heated rods, tubes, and flat plates, no solutions are yet available to describe the rewetting process of a hot plate subjected to a uniform heating. A model is presented to analyze the rewetting process of such plates with and without grooves. Approximate analytical solutions are presented for the prediction of the rewetting velocity and the transient temperature profiles of the plates. It is shown that the present rewetting velocity solution reduces correctly to the existing solution for the rewetting of an initially hot isothermal plate without heating from beneath the plate. Numerical solutions have also been obtained to validate the analytical solutions.

Phase 2 of the array automated assembly task for the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Petersen, R. C.

1980-01-01

Studies were conducted on several fundamental aspects of electroless nickel/solder metallization for silicon solar cells. A process, which precedes the electroless nickel plating with several steps of palladium plating and heat treatment, was compared directly with single step electroless nickel plating. Work was directed toward answering specific questions concerning the effect of silicon surface oxide on nickel plating, effects of thermal stresses on the metallization, sintering of nickel plated on silicon, and effects of exposure to the plating solution on solar cell characteristics. The process was found to be extremely lengthy and cumbersome, and was also found to produce a product virtually identical to that produced by single step electroless nickel plating, as shown by adhesion tests and electrical characteristics of cells under illumination.

A Strontium-Modified Titanium Surface Produced by a New Method and Its Biocompatibility In Vitro

PubMed Central

Liu, Chundong; Zhang, Yanli; Wang, Lichao; Zhang, Xinhua; Chen, Qiuyue; Wu, Buling

2015-01-01

Objective To present a new and effective method of producing titanium surfaces modified with strontium and to investigate the surface characteristics and in vitro biocompatibility of titanium (Ti) surfaces modified with strontium (Sr) for bone implant applications. Materials and Methods Sr-modified Ti surfaces were produced by sequential treatments with NaOH, strontium acetate, heat and water. The surface characteristics and the concentration of the Sr ions released from the samples were examined. Cell adhesion, morphology and growth were investigated using osteoblasts isolated from the calvaria of neonatal Sprague-Dawley rats. Expression of osteogenesis-related genes and proteins was examined to assess the effect of the Sr-modified Ti surfaces on osteoblasts. Results The modified titanium surface had a mesh structure with significantly greater porosity, and approximately5.37±0.35at.% of Sr was incorporated into the surface. The hydrophilicity was enhanced by the incorporation of Sr ions and water treatment. The average amounts of Sr released from the Sr-modified plates subjected to water treatment were slight higher than the plates without water treatment. Sr promoted cellular adhesion, spreading and growth compared with untreated Ti surfaces. The Sr-modified Ti plates also promoted expression of osteogenesis-related genes,and expression of OPN and COL-І by osteoblasts. Ti plates heat treated at 700°C showed increased bioactivity in comparison with those treated at 600°C. Water treatment upregulated the expression of osteogenesis-related genes. Conclusions These results show that Sr-modification of Ti surfaces may improve bioactivity in vitro. Water treatment has enhanced the response of osteoblasts. The Sr-modified Ti heat-treated at 700°C exhibited better bioactivity compared with that heated at 600°C. PMID:26529234

A Strontium-Modified Titanium Surface Produced by a New Method and Its Biocompatibility In Vitro.

PubMed

Liu, Chundong; Zhang, Yanli; Wang, Lichao; Zhang, Xinhua; Chen, Qiuyue; Wu, Buling

2015-01-01

To present a new and effective method of producing titanium surfaces modified with strontium and to investigate the surface characteristics and in vitro biocompatibility of titanium (Ti) surfaces modified with strontium (Sr) for bone implant applications. Sr-modified Ti surfaces were produced by sequential treatments with NaOH, strontium acetate, heat and water. The surface characteristics and the concentration of the Sr ions released from the samples were examined. Cell adhesion, morphology and growth were investigated using osteoblasts isolated from the calvaria of neonatal Sprague-Dawley rats. Expression of osteogenesis-related genes and proteins was examined to assess the effect of the Sr-modified Ti surfaces on osteoblasts. The modified titanium surface had a mesh structure with significantly greater porosity, and approximately5.37±0.35at.% of Sr was incorporated into the surface. The hydrophilicity was enhanced by the incorporation of Sr ions and water treatment. The average amounts of Sr released from the Sr-modified plates subjected to water treatment were slight higher than the plates without water treatment. Sr promoted cellular adhesion, spreading and growth compared with untreated Ti surfaces. The Sr-modified Ti plates also promoted expression of osteogenesis-related genes,and expression of OPN and COL-І by osteoblasts. Ti plates heat treated at 700°C showed increased bioactivity in comparison with those treated at 600°C. Water treatment upregulated the expression of osteogenesis-related genes. These results show that Sr-modification of Ti surfaces may improve bioactivity in vitro. Water treatment has enhanced the response of osteoblasts. The Sr-modified Ti heat-treated at 700°C exhibited better bioactivity compared with that heated at 600°C.

Three Dimensional Forming Simulation of the Shielded Slot Plate for the MCFC Using a Ductile Fracture Criterion

NASA Astrophysics Data System (ADS)

Lee, C. H.; Yang, D. Y.; Lee, S. R.; Chang, I. G.; Lee, T. W.

2011-08-01

The shielded slot plate, which has a sheared corrugated trapezoidal pattern, is a component of the metallic bipolar plate for the molten carbonate fuel cell (MCFC). In order to increase the efficiency of the fuel cell, the unit cell of the shielded slot plate should have a relatively large upper area. Additionally, defects from the forming process should be minimized. In order to simulate the slitting process, whereby sheared corrugated patterns are formed, ductile fracture criteria based on the histories of stress and strain are employed. The user material subroutine VUMAT is employed for implementation of the material and ductile fracture criteria in the commercial FEM software ABAQUS. The variables of the ductile fracture criteria were determined by comparing the simulation results and the experimental results of the tension test and the shearing test. Parametric studies were conducted to determine the critical value of the ductile fracture criterion. Employing these ductile fracture criteria, the three dimensional forming process of the shielded slot plate was numerically simulated. The effects of the slitting process in the forming process of the shielded slot plate were analyzed through a FEM simulation and experimental studies. Finally, experiments involving microscopic and macroscopic observations were conducted to verify the numerical simulations of the 3-step forming process.

Measuring surfactant concentration in plating solutions

DOEpatents

Bonivert, William D.; Farmer, Joseph C.; Hachman, John T.

1989-01-01

An arrangement for measuring the concentration of surfactants in a electrolyte containing metal ions includes applying a DC bias voltage and a modulated voltage to a counter electrode. The phase angle between the modulated voltage and the current response to the modulated voltage at a working electrode is correlated to the surfactant concentration.

Anomalous Accretionary Margin Topography Formed By Repeated Earthquakes

NASA Astrophysics Data System (ADS)

Furlong, Kevin P.

2014-05-01

It has long been recognized that accretionary margins of major subduction zones undergo substantial deformation. However even with the large amounts of shortening accommodated within the margin, for most subduction zones, there is an extended submarine portion to the accretionary, highly-deformed upper-plate between the trench and the coast. This is a vexing situation since this submarine section typically overlies the actual locked or coupled patch of the plate interface. The result of this is added difficulty in directly observing processes related to the plate interface coupling - such processes as micro-seismicity and the actual patterns of plate coupling. There are a few locations globally in which there are sub-aerially exposed terranes that lie closer to the trench and overlie the inferred coupled or seismogenic portion of the plate interface. Such regions have taken on significance in subduction zone studies as they provide locations to observe the plate interface coupling effects in the near-field. In particular the Pacific coast of Costa Rica provides such a location, and there has been substantial geologic, geophysical, and geodetic research exploiting the positions of these near-trench peninsulas (Nicoya, Osa, and Burica). These sites provide near-field access to plate-interface processes, but whether they represent typical subduction zone behavior remains an open question as the deformational processes or inherited structures that have produced this anomalous topography are not well constrained. Simply put, if the existence of these sub-aerial, near-trench terranes is a result of anomalous behavior on the plate interface (as has been suggested), then their utility in providing high-fidelity near-field insight into the plate interface properties and processes is substantially reduced. Here we propose a new mechanism that could be responsible for the formation of both the Nicoya and Osa Peninsulas in the past, and is currently producing a third peninsula - the Burica Peninsula at the intersection of the Panama fracture zone and the margin. Specifically we propose that the anomalous topography along the Pacific coast of Costa Rica has been produced by repeated, great subduction earthquakes that have ruptured across the boundary separating the Cocos and Nazca plates - the subducted continuation of the Panama fracture zone. The pattern of upper-plate shortening generated by such a process (documented in the 2007 Mw 8.1 Solomon Islands earthquake, which produced co-seismic localized uplift above the subducted transform plate boundary) convolved with the migration history of the Panama triple junction (PTJ) is proposed as the mechanism to produce substantial along-margin, long-lived accretionary margin topography. Specifically we argue that repeated great subduction earthquakes that rupture across fundamental plate boundary structures can produce substantial, long-lived upper plate deformation above the inter-seismically coupled plate interface.

Alternative Conceptions of Plate Tectonics Held by Nonscience Undergraduates

ERIC Educational Resources Information Center

Clark, Scott K.; Libarkin, Julie C.; Kortz, Karen M.; Jordan, Sarah C.

2011-01-01

The theory of plate tectonics is the conceptual model through which most dynamic processes on Earth are understood. A solid understanding of the basic tenets of this theory is crucial in developing a scientifically literate public and future geoscientists. The size of plates and scale of tectonic processes are inherently unobservable,…

Origin of the Indian Ocean-type isotopic signature in basalts from Philippine Sea plate spreading centers: An assessment of local versus large-scale processes

NASA Astrophysics Data System (ADS)

Hickey-Vargas, Rosemary

1998-09-01

Basalts erupted from spreading centers on the Philippine Sea plate between 50 Ma and the present have the distinctive isotopic characteristics of Indian Ocean mid-ocean ridge basalt (MORB), such as high 208Pb/204Pb and low 143Nd/144Nd for a given 206Pb/204Pb compared with Pacific and Atlantic Ocean MORB. This feature may indicate that the upper mantle of the Philippine Sea plate originated as part of the existing Indian Ocean upper mantle domain, or, alternatively, that local processes duplicated these isotopic characteristics within the sub-Philippine Sea plate upper mantle. Synthesis of new and published isotopic data for Philippine Sea plate basin basalts and island arc volcanic rocks, radiometric ages, and tectonic reconstructions of the plate indicates that local processes, such as contamination of the upper mantle by subducted materials or by western Pacific mantle plumes, did not produce the Indian Ocean-type signature in Philippine Sea plate MORB. It is more likely that the plate originated over a rapidly growing Indian Ocean upper mantle domain that had spread into the area between Australia/New Guinea and southeast Asia before 50 Ma.

Antimicrobial Properties of Diamond-Like Carbon/Silver Nanocomposite Thin Films Deposited on Textiles: Towards Smart Bandages

PubMed Central

Juknius, Tadas; Ružauskas, Modestas; Tamulevičius, Tomas; Šiugždinienė, Rita; Juknienė, Indrė; Vasiliauskas, Andrius; Jurkevičiūtė, Aušrinė; Tamulevičius, Sigitas

2016-01-01

In the current work, a new antibacterial bandage was proposed where diamond-like carbon with silver nanoparticle (DLC:Ag)-coated synthetic silk tissue was used as a building block. The DLC:Ag structure, the dimensions of nanoparticles, the silver concentration and the silver ion release were studied systematically employing scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic absorption spectroscopy, respectively. Antimicrobial properties were investigated using microbiological tests (disk diffusion method and spread-plate technique). The DLC:Ag layer was stabilized on the surface of the bandage using a thin layer of medical grade gelatin and cellulose. Four different strains of Staphylococcus aureus extracted from humans’ and animals’ infected wounds were used. It is demonstrated that the efficiency of the Ag+ ion release to the aqueous media can be increased by further RF oxygen plasma etching of the nanocomposite. It was obtained that the best antibacterial properties were demonstrated by the plasma-processed DLC:Ag layer having a 3.12 at % Ag surface concentration with the dominating linear dimensions of nanoparticles being 23.7 nm. An extra protective layer made from cellulose and gelatin with agar contributed to the accumulation and efficient release of silver ions to the aqueous media, increasing bandage antimicrobial efficiency up to 50% as compared to the single DLC:Ag layer on textile. PMID:28773494

Antimicrobial Properties of Diamond-Like Carbon/Silver Nanocomposite Thin Films Deposited on Textiles: Towards Smart Bandages.

PubMed

Juknius, Tadas; Ružauskas, Modestas; Tamulevičius, Tomas; Šiugždinienė, Rita; Juknienė, Indrė; Vasiliauskas, Andrius; Jurkevičiūtė, Aušrinė; Tamulevičius, Sigitas

2016-05-13

In the current work, a new antibacterial bandage was proposed where diamond-like carbon with silver nanoparticle (DLC:Ag)-coated synthetic silk tissue was used as a building block. The DLC:Ag structure, the dimensions of nanoparticles, the silver concentration and the silver ion release were studied systematically employing scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic absorption spectroscopy, respectively. Antimicrobial properties were investigated using microbiological tests (disk diffusion method and spread-plate technique). The DLC:Ag layer was stabilized on the surface of the bandage using a thin layer of medical grade gelatin and cellulose. Four different strains of Staphylococcus aureus extracted from humans' and animals' infected wounds were used. It is demonstrated that the efficiency of the Ag⁺ ion release to the aqueous media can be increased by further RF oxygen plasma etching of the nanocomposite. It was obtained that the best antibacterial properties were demonstrated by the plasma-processed DLC:Ag layer having a 3.12 at % Ag surface concentration with the dominating linear dimensions of nanoparticles being 23.7 nm. An extra protective layer made from cellulose and gelatin with agar contributed to the accumulation and efficient release of silver ions to the aqueous media, increasing bandage antimicrobial efficiency up to 50% as compared to the single DLC:Ag layer on textile.

VUV spectroscopic observations on the SABRE applied-B ion diode

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

Filuk, A.B.; Nash, T.J.; Noack, D.D.

We are using VUV spectroscopy to study the ion source region on the SABRE applied-B extraction ion diode. The VUV diagnostic views the anode-cathode gap perpendicular to the ion acceleration direction, and images a region 0--1 mm from the anode onto the entrance slit of a I m normal-incidence spectrometer. Time resolution is obtained by gating multiple striplines of a CuI- or MgF{sub 2} -coated micro-channel plate intensifier. We report on results with a passive proton/carbon ion source. Lines of carbon and oxygen are observed over 900--1600 {angstrom}. The optical depths of most of the lines are less than ormore » of order 1. Unfolding the Doppler broadening of the ion lines in the source plasma, we calculate the contribution of the source to the accelerated C IV ion micro-divergence as 4 mrad at peak power. Collisional-radiative modeling of oxygen line intensities provides the source plasma average electron density of 7{times}10{sup 16} cm{sup {minus}3} and temperature of 10 eV Measurements are planned with a lithium ion source and with VUV absorption spectroscopy.« less

Measuring ion velocity distribution functions through high-aspect ratio holes in inductively coupled plasmas

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

Cunge, G., E-mail: gilles.cunge@cea.fr; Darnon, M.; Dubois, J.

2016-02-29

Several issues associated with plasma etching of high aspect ratio structures originate from the ions' bombardment of the sidewalls of the feature. The off normal angle incident ions are primarily due to their temperature at the sheath edge and possibly to charging effects. We have measured the ion velocity distribution function (IVDF) at the wafer surface in an industrial inductively coupled plasma reactor by using multigrid retarding field analyzers (RFA) in front of which we place 400 μm thick capillary plates with holes of 25, 50, and 100 μm diameters. The RFA then probes IVDF at the exit of the holes withmore » Aspect Ratios (AR) of 16, 8, and 4, respectively. The results show that the ion flux dramatically drops with the increase in AR. By comparing the measured IVDF with an analytical model, we concluded that the ion temperature is 0.27 eV in our plasma conditions. The charging effects are also observed and are shown to significantly reduce the ion energy at the bottom of the feature but only with a “minor” effect on the ion flux and the shape of the IVDF.« less

Preparation and luminescent properties of lanthanide (Eu3+ and Tb3+) complexes grafted to 3-aminopropyltriethoxysilane by covalent bonds

NASA Astrophysics Data System (ADS)

Zhang, Wenjun; Wang, Haiyan

2015-12-01

A novel precursor PMA-Si was synthesized by modifying 1,2,4,5-benzene-tetracarboxylic acid (PMA) with 3-aminopropyltriethoxysilane (APTES). Then the hybrids were prepared by PMA-Si coordinating to lanthanide ions (Eu3+ and Tb3+) in sol-gel process. In order to improve luminescent efficiency, 1,10-Phenanthroline (Phen) was introduced to the system as the second ligand. As-prepared compounds in sol condition were coated on quartz plates to form a layer of thin film, which was different from other similar hybrids. The properties of the hybrids were characterized by FT-IR, fluorescence spectra, TG and SEM. The results showed that the obtained materials enhanced thermal stability, mechanical resistances, waterproofness as well as machining properties.

Vacuum pull down method for an enhanced bonding process

DOEpatents

Davidson, James C.; Balch, Joseph W.

1999-01-01

A process for effectively bonding arbitrary size or shape substrates. The process incorporates vacuum pull down techniques to ensure uniform surface contact during the bonding process. The essence of the process for bonding substrates, such as glass, plastic, or alloys, etc., which have a moderate melting point with a gradual softening point curve, involves the application of an active vacuum source to evacuate interstices between the substrates while at the same time providing a positive force to hold the parts to be bonded in contact. This enables increasing the temperature of the bonding process to ensure that the softening point has been reached and small void areas are filled and come in contact with the opposing substrate. The process is most effective where at least one of the two plates or substrates contain channels or grooves that can be used to apply vacuum between the plates or substrates during the thermal bonding cycle. Also, it is beneficial to provide a vacuum groove or channel near the perimeter of the plates or substrates to ensure bonding of the perimeter of the plates or substrates and reduce the unbonded regions inside the interior region of the plates or substrates.

Growth of 1.5 micron gallium indium nitrogen arsenic antimonide vertical cavity surface emitting lasers by molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Wistey, Mark Allan

Fiber optics has revolutionized long distance communication and long haul networks, allowing unimaginable data speeds and noise-free telephone calls around the world for mere pennies per hour at the trunk level. But the high speeds of optical fiber generally do not extend to individual workstations or to the home, in large part because it has been difficult and expensive to produce lasers which emitted light at wavelengths which could take advantage of optical fiber. One of the most promising solutions to this problem is the development of a new class of semiconductors known as dilute nitrides. Dilute nitrides such as GaInNAs can be grown directly on gallium arsenide, which allows well-established processing techniques. More important, gallium arsenide allows the growth of vertical-cavity surface-emitting lasers (VCSELs), which can be grown in dense, 2D arrays on each wafer, providing tremendous economies of scale for manufacturing, testing, and packaging. Unfortunately, GaInNAs lasers have suffered from what has been dubbed the "nitrogen penalty," with high thresholds and low efficiency as the fraction of nitrogen in the semiconductor was increased. This thesis describes the steps taken to identify and essentially eliminate the nitrogen penalty. Protecting the wafer surface from plasma ignition, using an arsenic cap, greatly improved material quality. Using a Langmuir probe, we further found that the nitrogen plasma source produced a large number of ions which damaged the wafer during growth. The ions were dramatically reduced using deflection plates. Low voltage deflection plates were found to be preferable to high voltages, and simulations showed low voltages to be adequate for ion removal. The long wavelengths from dilute nitrides can be partly explained by wafer damage during growth. As a result of these studies, we demonstrated the first CW, room temperature lasers at wavelengths beyond 1.5mum on gallium arsenide, and the first GaInNAs(Sb) VCSELs beyond 1.31mum: 1.46mum. These techniques offer the promise of inexpensive, high speed fiber networking.

Sorption of lead ions on diatomite and manganese oxides modified diatomite.

PubMed

Al-Degs, Y; Khraisheh, M A; Tutunji, M F

2001-10-01

Naturally occurring diatomaceous earth (diatomite) has been tested as a potential sorbent for Pb(II) ions. The intrinsic exchange properties were further improved by modification with manganese oxides. Modified adsorbent (referred to as Mn-diatomite) showed a higher tendency for adsorbing lead ions from solution at pH 4. The high performance exhibited by Mn-diatomite was attributed to increased surface area and higher negative surface charge after modification. Scanning electron microscope pictures revealed a birnessite structure of manganese oxides, which was featured by a plate-like-crystal structure. Diatomite filtration quality was improved after modification by manganese oxides. Good filtration qualities combined with high exchange capacity emphasised the potential use of Mn-diatomite in filtration systems.

Hand portable thin-layer chromatography system

DOEpatents

Haas, Jeffrey S.; Kelly, Fredrick R.; Bushman, John F.; Wiefel, Michael H.; Jensen, Wayne A.

2000-01-01

A hand portable, field-deployable thin-layer chromatography (TLC) unit and a hand portable, battery-operated unit for development, illumination, and data acquisition of the TLC plates contain many miniaturized features that permit a large number of samples to be processed efficiently. The TLC unit includes a solvent tank, a holder for TLC plates, and a variety of tool chambers for storing TLC plates, solvent, and pipettes. After processing in the TLC unit, a TLC plate is positioned in a collapsible illumination box, where the box and a CCD camera are optically aligned for optimal pixel resolution of the CCD images of the TLC plate. The TLC system includes an improved development chamber for chemical development of TLC plates that prevents solvent overflow.

Illumination box and camera system

DOEpatents

Haas, Jeffrey S.; Kelly, Fredrick R.; Bushman, John F.; Wiefel, Michael H.; Jensen, Wayne A.; Klunder, Gregory L.

2002-01-01

A hand portable, field-deployable thin-layer chromatography (TLC) unit and a hand portable, battery-operated unit for development, illumination, and data acquisition of the TLC plates contain many miniaturized features that permit a large number of samples to be processed efficiently. The TLC unit includes a solvent tank, a holder for TLC plates, and a variety of tool chambers for storing TLC plates, solvent, and pipettes. After processing in the TLC unit, a TLC plate is positioned in a collapsible illumination box, where the box and a CCD camera are optically aligned for optimal pixel resolution of the CCD images of the TLC plate. The TLC system includes an improved development chamber for chemical development of TLC plates that prevents solvent overflow.

Peen plating

NASA Technical Reports Server (NTRS)

Babecki, A. J. (Inventor); Haehner, C. L.

1973-01-01

A process for metal plating which comprises spraying a mixture of metallic powder and small peening particles at high velocity against a surface is described. The velocity must be sufficient to impact and bond metallic powder onto the surface. In the case of metal surfaces, the process has as one of its advantages providing mechanical working (hardening) of the surface simultaneously with the metal plating.

Investigation of the charging characteristics of micrometer sized droplets based on parallel plate capacitor model.

PubMed

Zhang, Yanzhen; Liu, Yonghong; Wang, Xiaolong; Shen, Yang; Ji, Renjie; Cai, Baoping

2013-02-05

The charging characteristics of micrometer sized aqueous droplets have attracted more and more attentions due to the development of the microfluidics technology since the electrophoretic motion of a charged droplet can be used as the droplet actuation method. This work proposed a novel method of investigating the charging characteristics of micrometer sized aqueous droplets based on parallel plate capacitor model. With this method, the effects of the electric field strength, electrolyte concentration, and ion species on the charging characteristics of the aqueous droplets was investigated. Experimental results showed that the charging characteristics of micrometer sized droplets can be investigated by this method.

Quadrant anode image sensor

NASA Technical Reports Server (NTRS)

Lampton, M.; Malina, R. F.

1976-01-01

A position-sensitive event-counting electronic readout system for microchannel plates (MCPs) is described that offers the advantages of high spatial resolution and fast time resolution. The technique relies upon a four-quadrant electron-collecting anode located behind the output face of the microchannel plate, so that the electron cloud from each detected event is partly intercepted by each of the four quadrants. The relative amounts of charge collected by each quadrant depend on event position, permitting each event to be localized with two ratio circuits. A prototype quadrant anode system for ion, electron, and extreme ultraviolet imaging is described. The spatial resolution achieved, about 10 microns, allows individual MCP channels to be distinguished.

Direct view on the phase evolution in individual LiFePO4 nanoparticles during Li-ion battery cycling.

PubMed

Zhang, Xiaoyu; van Hulzen, Martijn; Singh, Deepak P; Brownrigg, Alex; Wright, Jonathan P; van Dijk, Niels H; Wagemaker, Marnix

2015-09-23

Phase transitions in Li-ion electrode materials during (dis)charge are decisive for battery performance, limiting high-rate capabilities and playing a crucial role in the cycle life of Li-ion batteries. However, the difficulty to probe the phase nucleation and growth in individual grains is hindering fundamental understanding and progress. Here we use synchrotron microbeam diffraction to disclose the cycling rate-dependent phase transition mechanism within individual particles of LiFePO4, a key Li-ion electrode material. At low (dis)charge rates well-defined nanometer thin plate-shaped domains co-exist and transform much slower and concurrent as compared with the commonly assumed mosaic transformation mechanism. As the (dis)charge rate increases phase boundaries become diffuse speeding up the transformation rates of individual grains. Direct observation of the transformation of individual grains reveals that local current densities significantly differ from what has previously been assumed, giving new insights in the working of Li-ion battery electrodes and their potential improvements.

Direct view on the phase evolution in individual LiFePO4 nanoparticles during Li-ion battery cycling

PubMed Central

Zhang, Xiaoyu; van Hulzen, Martijn; Singh, Deepak P.; Brownrigg, Alex; Wright, Jonathan P.; van Dijk, Niels H.; Wagemaker, Marnix

2015-01-01

Phase transitions in Li-ion electrode materials during (dis)charge are decisive for battery performance, limiting high-rate capabilities and playing a crucial role in the cycle life of Li-ion batteries. However, the difficulty to probe the phase nucleation and growth in individual grains is hindering fundamental understanding and progress. Here we use synchrotron microbeam diffraction to disclose the cycling rate-dependent phase transition mechanism within individual particles of LiFePO4, a key Li-ion electrode material. At low (dis)charge rates well-defined nanometer thin plate-shaped domains co-exist and transform much slower and concurrent as compared with the commonly assumed mosaic transformation mechanism. As the (dis)charge rate increases phase boundaries become diffuse speeding up the transformation rates of individual grains. Direct observation of the transformation of individual grains reveals that local current densities significantly differ from what has previously been assumed, giving new insights in the working of Li-ion battery electrodes and their potential improvements. PMID:26395323

3D ion flow measurements and simulations near a boundary at oblique incidence to a magnetic field

NASA Astrophysics Data System (ADS)

Thompson, Derek S.; Keniley, Shane; Khaziev, Rinat; Curreli, Davide; Good, Timothy N.; Henriquez, Miguel; McIlvain, Julianne; Siddiqui, M. Umair; Scime, Earl E.

2016-10-01

Boundaries at oblique incidence to magnetic fields are abundant in magnetic confinement plasmas. The ion dynamics near these boundaries has implications for applications such as tokamak divertor wall loading and Hall thruster channel erosion. We present 3D, non-perturbative measurements of ion velocity distribution functions (IVDFs), providing ion temperatures and flows upstream of a grounded stainless steel limiter plate immersed in an argon plasma, oriented obliquely to the background axial magnetic field (ψ = 74°). The spatial resolution of the measurements is sufficient to probe the kinetic details of magnetic presheath structures, which span several ion Larmor radii ( 1 cm). Furthermore, we report probe measurements of electron density and temperature, and of local electric potential. To complement these measurements, results from particle-in-cell and Boltzmann models of the same region are presented. These models allow for point-to-point comparison of simulated and measured electrostatic structures and IVDFs at high spatial resolution. NSF Award PHYS-1360278.

Potential of ethylenediaminedi(o-hydroxyphenylacetic acid) and N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid for the determination of metal ions by capillary electrophoresis.

PubMed

Krokhin, O V; Kuzina, O V; Hoshino, H; Shpigun, O A; Yotsuyanagi, T

2000-08-25

Two aromatic polyaminocarboxylate ligands, ethylenediaminedi(o-hydroxyphenylacetic acid) (EDDHA) and N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED), were applied for the separation of transition and heavy metal ions by the ion-exchange variant of electrokinetic chromatography. EDDHA structure contains two chiral carbon centers. It makes it impossible to use the commercially available ligand. All the studied metal ions showed two peaks, which correspond to meso and rac forms of the ligand. The separation of metal-HBED chelates was performed using poly(diallyldimethylammonium) polycations in mixed acetate-hydroxide form. Simultaneous separation of nine single- and nine double-charged HBED chelates, including In(III), Ga(III), Co(II)-(III) and Mn(II)-(III) pairs demonstrated the efficiency of 40,000-400,000 theoretical plates. The separation of Co(III), Fe(III) complexes with different arrangements of donor groups and oxidation of Co(II), Mn(H), Fe(II) ions in reaction with HBED have been discussed.

Solid State Welding Development at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Ding, Robert J.; Walker, Bryant

2012-01-01

What is TSW and USW? TSW is a solid state weld process consisting of an induction coil heating source, a stir rod, and non-rotating containment plates Independent heating, stirring and forging controls Decouples the heating, stirring and forging process elements of FSW. USW is a solid state weld process consisting of an induction coil heating source, a stir rod, and a non-rotating containment plate; Ultrasonic energy integrated into non-rotating containment plate and stir rod; Independent heating, stirring and forging controls; Decouples the heating, stirring and forging process elements of FSW.

Optical processing furnace with quartz muffle and diffuser plate

DOEpatents

Sopori, Bhushan L.

1995-01-01

An optical furnace for annealing a process wafer comprising a source of optical energy, a quartz muffle having a door to hold the wafer for processing, and a quartz diffuser plate to diffuse the light impinging on the quartz muffle; a feedback system with a light sensor located in the door or wall of the muffle is also provided for controlling the source of optical energy. The quartz for the diffuser plate is surface etched (to give the quartz diffusive qualities) in the furnace during a high intensity burn-in process.

Neural activation patterns and connectivity in visual attention during Number and Non-number processing: An ERP study using the Ishihara pseudoisochromatic plates.

PubMed

Al-Marri, Faraj; Reza, Faruque; Begum, Tahamina; Hitam, Wan Hazabbah Wan; Jin, Goh Khean; Xiang, Jing

2017-10-25

Visual cognitive function is important to build up executive function in daily life. Perception of visual Number form (e.g., Arabic digit) and numerosity (magnitude of the Number) is of interest to cognitive neuroscientists. Neural correlates and the functional measurement of Number representations are complex occurrences when their semantic categories are assimilated with other concepts of shape and colour. Colour perception can be processed further to modulate visual cognition. The Ishihara pseudoisochromatic plates are one of the best and most common screening tools for basic red-green colour vision testing. However, there is a lack of study of visual cognitive function assessment using these pseudoisochromatic plates. We recruited 25 healthy normal trichromat volunteers and extended these studies using a 128-sensor net to record event-related EEG. Subjects were asked to respond by pressing Numbered buttons when they saw the Number and Non-number plates of the Ishihara colour vision test. Amplitudes and latencies of N100 and P300 event related potential (ERP) components were analysed from 19 electrode sites in the international 10-20 system. A brain topographic map, cortical activation patterns and Granger causation (effective connectivity) were analysed from 128 electrode sites. No major significant differences between N100 ERP components in either stimulus indicate early selective attention processing was similar for Number and Non-number plate stimuli, but Non-number plate stimuli evoked significantly higher amplitudes, longer latencies of the P300 ERP component with a slower reaction time compared to Number plate stimuli imply the allocation of attentional load was more in Non-number plate processing. A different pattern of asymmetric scalp voltage map was noticed for P300 components with a higher intensity in the left hemisphere for Number plate tasks and higher intensity in the right hemisphere for Non-number plate tasks. Asymmetric cortical activation and connectivity patterns revealed that Number recognition occurred in the occipital and left frontal areas where as the consequence was limited to the occipital area during the Non-number plate processing. Finally, the results displayed that the visual recognition of Numbers dissociates from the recognition of Non-numbers at the level of defined neural networks. Number recognition was not only a process of visual perception and attention, but it was also related to a higher level of cognitive function, that of language.

Slits, plates, and Poisson-Boltzmann theory in a local formulation of nonlocal electrostatics

NASA Astrophysics Data System (ADS)

Paillusson, Fabien; Blossey, Ralf

2010-11-01

Polar liquids like water carry a characteristic nanometric length scale, the correlation length of orientation polarizations. Continuum theories that can capture this feature commonly run under the name of “nonlocal” electrostatics since their dielectric response is characterized by a scale-dependent dielectric function ɛ(q) , where q is the wave vector; the Poisson(-Boltzmann) equation then turns into an integro-differential equation. Recently, “local” formulations have been put forward for these theories and applied to water, solvated ions, and proteins. We review the local formalism and show how it can be applied to a structured liquid in slit and plate geometries, and solve the Poisson-Boltzmann theory for a charged plate in a structured solvent with counterions. Our results establish a coherent picture of the local version of nonlocal electrostatics and show its ease of use when compared to the original formulation.

An all-reflective polarization rotator

NASA Astrophysics Data System (ADS)

Bohus, J.; Budai, Judit; Kalashnikov, M.; Osvay, K.

2017-05-01

The conceptual design and proof of principle experimental results of a polarization rotator based on mirrors are presented. The device is suitable for any-angle, online rotation of the plane of polarization of high peak intensity ultrashort laser pulses. Controllable rotation of the polarization vector of short laser pulses with a broad bandwidth requires achromatic retarding plates which have a limited scalability and the substantial plate thickness can lead to pulse broadening and inaccurate polarization rotation. Polarization rotators based on reflective optical elements are preferable alternatives to wave plates especially when used in high average power or high peak intensity ultra-short laser systems. The control of the polarization state is desirable in many laser-matter interaction experiments e.g., high harmonic and attosecond pulse generation, electron, proton and ion acceleration, electron-positron pair creating, vacuum nonlinear polarization effect. The device can also serve as a beam attenuator, in combination with a linear polarizer.