Ring-like oligomers of Synaptotagmins and related C2 domain proteins

PubMed Central

Zanetti, Maria N; Bello, Oscar D; Wang, Jing; Coleman, Jeff; Cai, Yiying; Sindelar, Charles V; Rothman, James E; Krishnakumar, Shyam S

2016-01-01

We recently reported that the C2AB portion of Synaptotagmin 1 (Syt1) could self-assemble into Ca2+-sensitive ring-like oligomers on membranes, which could potentially regulate neurotransmitter release. Here we report that analogous ring-like oligomers assemble from the C2AB domains of other Syt isoforms (Syt2, Syt7, Syt9) as well as related C2 domain containing protein, Doc2B and extended Synaptotagmins (E-Syts). Evidently, circular oligomerization is a general and conserved structural aspect of many C2 domain proteins, including Synaptotagmins. Further, using electron microscopy combined with targeted mutations, we show that under physiologically relevant conditions, both the Syt1 ring assembly and its rapid disruption by Ca2+ involve the well-established functional surfaces on the C2B domain that are important for synaptic transmission. Our data suggests that ring formation may be triggered at an early step in synaptic vesicle docking and positions Syt1 to synchronize neurotransmitter release to Ca2+ influx. DOI: http://dx.doi.org/10.7554/eLife.17262.001 PMID:27434670

Joining mechanism with stem tension and interlocked compression ring

DOEpatents

James, Allister W.; Morrison, Jay A.

2012-09-04

A stem (34) extends from a second part (30) through a hole (28) in a first part (22). A groove (38) around the stem provides a non-threaded contact surface (42) for a ring element (44) around the stem. The ring element exerts an inward force against the non-threaded contact surface at an angle that creates axial tension (T) in the stem, pulling the second part against the first part. The ring element is formed of a material that shrinks relative to the stem by sintering. The ring element may include a split collet (44C) that fits partly into the groove, and a compression ring (44E) around the collet. The non-threaded contact surface and a mating distal surface (48) of the ring element may have conic geometries (64). After shrinkage, the ring element is locked onto the stem.

Crystallographic structure of the turbine C-ring from spinach chloroplast F-ATP synthase

PubMed Central

Balakrishna, Asha Manikkoth; Seelert, Holger; Marx, Sven-Hendric; Dencher, Norbert A.; Grüber, Gerhard

2014-01-01

In eukaryotic and prokaryotic cells, F-ATP synthases provide energy through the synthesis of ATP. The chloroplast F-ATP synthase (CF1FO-ATP synthase) of plants is integrated into the thylakoid membrane via its FO-domain subunits a, b, b’ and c. Subunit c with a stoichiometry of 14 and subunit a form the gate for H+-pumping, enabling the coupling of electrochemical energy with ATP synthesis in the F1 sector. Here we report the crystallization and structure determination of the c14-ring of subunit c of the CF1FO-ATP synthase from spinach chloroplasts. The crystals belonged to space group C2, with unit-cell parameters a=144.420, b=99.295, c=123.51 Å, and β=104.34° and diffracted to 4.5 Å resolution. Each c-ring contains 14 monomers in the asymmetric unit. The length of the c-ring is 60.32 Å, with an outer ring diameter 52.30 Å and an inner ring width of 40 Å. PMID:27919036

Clumping in the Cassini Division and C Ring: Constraints from Stellar Occultations

NASA Astrophysics Data System (ADS)

Colwell, J. E.; Jerousek, R. G.; Esposito, L. W.

2014-12-01

Particles in Saturn's rings are engaged in a constant tug-of-war between interparticle gravitational and adhesive forces that lead to clumping, on the one hand, and Keplerian shear that inhibits accretion on the other. Depending on the surface mass density of the rings and the local orbital velocity, ephemeral clumps or self-gravity wakes can form, giving the rings granularity on the scale of the most-unstable length scale against gravitational collapse. The A ring and many regions of the B ring are dominated by self-gravity wakes with a typical radial wavelength of ~50-100 m. A characteristic of self-gravity wakes is that they can effectively shadow the relatively empty spaces in between them, depending on viewing geometry. This leads to geometry-dependent measurements of optical depth in occultations of the rings. The C ring and Cassini Division have significantly lower surface mass densities than the A and B ring such that in most of these regions the most-unstable wavelength is comparable to the size of the ring particles (~1 m) so that self-gravity wake formation is not expected nor have its characteristics in various measurements been observed. Here we present measurements of the optical depth of the C ring and Cassini Division with the Cassini Ultraviolet Imaging Spectrograph (UVIS) showing variations with viewing geometry in the "ramp" regions and the Cassini Division "triple band". These variations are characteristic of self-gravity wakes. We place limits on clumping in other regions of the C ring and Cassini Division.

A C2HC zinc finger is essential for the RING-E2 interaction of the ubiquitin ligase RNF125

PubMed Central

Bijlmakers, Marie-José; Teixeira, João M. C.; Boer, Roeland; Mayzel, Maxim; Puig-Sàrries, Pilar; Karlsson, Göran; Coll, Miquel; Pons, Miquel; Crosas, Bernat

2016-01-01

The activity of RING ubiquitin ligases (E3s) depends on an interaction between the RING domain and ubiquitin conjugating enzymes (E2), but posttranslational events or additional structural elements, yet largely undefined, are frequently required to enhance or regulate activity. Here, we show for the ubiquitin ligase RNF125 that, in addition to the RING domain, a C2HC Zn finger (ZnF) is crucial for activity, and a short linker sequence (Li2120-128) enhances activity. The contribution of these regions was first shown with truncated proteins, and the essential role of the ZnF was confirmed with mutations at the Zn chelating Cys residues. Using NMR, we established that the C2HC ZnF/Li2120-128 region is crucial for binding of the RING domain to the E2 UbcH5a. The partial X-ray structure of RNF125 revealed the presence of extensive intramolecular interactions between the RING and C2HC ZnF. A mutation at one of the contact residues in the C2HC ZnF, a highly conserved M112, resulted in the loss of ubiquitin ligase activity. Thus, we identified the structural basis for an essential role of the C2HC ZnF and conclude that this domain stabilizes the RING domain, and is therefore required for binding of RNF125 to an E2. PMID:27411375

Large transient fault current test of an electrical roll ring

NASA Technical Reports Server (NTRS)

Yenni, Edward J.; Birchenough, Arthur G.

1992-01-01

The space station uses precision rotary gimbals to provide for sun tracking of its photoelectric arrays. Electrical power, command signals and data are transferred across the gimbals by roll rings. Roll rings have been shown to be capable of highly efficient electrical transmission and long life, through tests conducted at the NASA Lewis Research Center and Honeywell's Satellite and Space Systems Division in Phoenix, AZ. Large potential fault currents inherent to the power system's DC distribution architecture, have brought about the need to evaluate the effects of large transient fault currents on roll rings. A test recently conducted at Lewis subjected a roll ring to a simulated worst case space station electrical fault. The system model used to obtain the fault profile is described, along with details of the reduced order circuit that was used to simulate the fault. Test results comparing roll ring performance before and after the fault are also presented.

Butyl rubber O-ring seals: Revision of test procedures for stockpile materials

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

Domeier, L.A.; Wagter, K.R.

1996-12-01

Extensive testing showed little correlation between test slab and O-ring performance. New procedures, comparable to those used with the traditional test slabs, were defined for hardness, compression set, and tensile property testing on sacrificial O-ring specimens. Changes in target performance values were made as needed and were, in one case, tightened to reflect the O-ring performance data. An additional study was carried out on O-ring and slab performance vs cure cycle and showed little sensitivity of material performance to large changes in curing time. Aging and spectra of certain materials indicated that two sets of test slabs from current vendormore » were accidently made from EPDM rather than butyl rubber. Random testing found no O-rings made from EPDM. As a result, and additional spectroscope test will be added to the product acceptance procedures to verify the type of rubber compound used.« less

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 1 2013-10-01 2013-10-01 false DOT Drug Testing Semi-Annual Laboratory Report to... TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Pt. 40, App. C Appendix C to Part 40—DOT Drug Testing... of Drug and Alcohol Policy and Compliance, W62-300, 1200 New Jersey Avenue, SE., Washington, DC 20590...

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false DOT Drug Testing Semi-Annual Laboratory Report to... TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Pt. 40, App. C Appendix C to Part 40—DOT Drug Testing... of Drug and Alcohol Policy and Compliance, W62-300, 1200 New Jersey Avenue, SE., Washington, DC 20590...

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 1 2012-10-01 2012-10-01 false DOT Drug Testing Semi-Annual Laboratory Report to... TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Pt. 40, App. C Appendix C to Part 40—DOT Drug Testing... of Drug and Alcohol Policy and Compliance, W62-300, 1200 New Jersey Avenue, SE., Washington, DC 20590...

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 1 2014-10-01 2014-10-01 false DOT Drug Testing Semi-Annual Laboratory Report to... TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Pt. 40, App. C Appendix C to Part 40—DOT Drug Testing... of Drug and Alcohol Policy and Compliance, W62-300, 1200 New Jersey Avenue, SE., Washington, DC 20590...

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false DOT Drug Testing Semi-Annual Laboratory Report to... TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Pt. 40, App. C Appendix C to Part 40—DOT Drug Testing... of Drug and Alcohol Policy and Compliance, W62-300, 1200 New Jersey Avenue, SE., Washington, DC 20590...

Intrinsically disordered chromatin protein NUPR1 binds to the C-terminal region of Polycomb RING1B

PubMed Central

Santofimia-Castaño, Patricia; Rizzuti, Bruno; Pey, Ángel L.; Soubeyran, Philippe; Vidal, Miguel; Urrutia, Raúl; Iovanna, Juan L.; Neira, José L.

2017-01-01

Intrinsically disordered proteins (IDPs) are ubiquitous in eukaryotes, and they are often associated with diseases in humans. The protein NUPR1 is a multifunctional IDP involved in chromatin remodeling and in the development and progression of pancreatic cancer; however, the details of such functions are unknown. Polycomb proteins are involved in specific transcriptional cascades and gene silencing. One of the proteins of the Polycomb complex is the Ring finger protein 1 (RING1). RING1 is related to aggressive tumor features in multiple cancer types. In this work we characterized the interaction between NUPR1 and the paralogue RING1B in vitro, in silico, and in cellulo. The interaction occurred through the C-terminal region of RING1B (C-RING1B), with an affinity in the low micromolar range (∼10 μM). The binding region of NUPR1, mapped by NMR, was a hydrophobic polypeptide patch at the 30s region of its sequence, as pinpointed by computational results and site-directed mutagenesis at Ala33. The association between C-RING1B and wild-type NUPR1 also occurred in cellulo as tested by protein ligation assays; this interaction is inhibited by trifluoperazine, a drug known to hamper binding of wild-type NUPR1 with other proteins. Furthermore, the Thr68Gln and Ala33Gln/Thr68Gln mutants had a reduction in the binding toward C-RING1B as shown by in vitro, in silico, and in cellulo studies. This is an example of a well-folded partner of NUPR1, because its other interacting proteins are also unfolded. We hypothesize that NUPR1 plays an active role in chromatin remodeling and carcinogenesis, together with Polycomb proteins. PMID:28720707

10 CFR Appendix C to Part 30 - Criteria Relating to Use of Financial Tests and Self Guarantees for Providing Reasonable...

Code of Federal Regulations, 2012 CFR

2012-01-01

... Guarantees for Providing Reasonable Assurance of Funds for Decommissioning C Appendix C to Part 30 Energy... Pt. 30, App. C Appendix C to Part 30—Criteria Relating to Use of Financial Tests and Self Guarantees... repeat passage of the test within 90 days after the close of each succeeding fiscal year. C. If the...

[Vertical variability of Pinus sylvestris var. mongolica tree ring delta13C and its relationship with tree ring width in northern Daxing' an Mountains of Northeast China].

PubMed

Shang, Zhi-Yuan; Wang, Jian; Zhang, Wen; Li, Yan-Yan; Cui, Ming-Xing; Chen, Zhen-Ju; Zhao, Xing-Yun

2013-01-01

A measurement was made on the vertical direction tree ring stable carbon isotope ratio (delta13C) and tree ring width of Pinus sylvestris var. mongolica in northern Daxing' an Mountains of Northeast China, with the relationship between the vertical direction variations of the tree ring delta13C and tree ring width analyzed. In the whole ring of xylem, earlywood (EW) and bark endodermis, the delta13C all exhibited an increasing trend from the top to the base at first, with the maximum at the bottom of tree crown, and then, decreased rapidly to the minimum downward. The EW and late-wood (LW) had an increasing ratio of average tree ring width from the base to the top. The average annual sequence of the delta13C in vertical direction had an obvious reverse correspondence with the average annual sequence of tree ring width, and had a trend comparatively in line with the average annual sequence of the tree ring width ratio of EW to LW above tree crown. The variance analysis showed that there existed significant differences in the sequences of tree ring delta13C and ring width in vertical direction, and the magnitude of vertical delta13C variability was basically the same as that of the inter-annual delta13C variability. The year-to-year variation trend of the vertical delta13C sequence was approximately identical. For each sample, the delta13C sequence at the same heights was negatively correlated with the ring width sequence, but the statistical significance differed with tree height.

Physiological Responses during Cycling With Oval Chainrings (Q-Ring) and Circular Chainrings.

PubMed

Cordova, Alfredo; Latasa, Iban; Seco, Jesus; Villa, Gerardo; Rodriguez-Falces, Javier

2014-05-01

The aim of this study was to compare the physiological responses of cyclists using round (C-ring) or oval (Q-ring) chainrings during an incremental test until exhaustion. Following a randomized design, twelve male elite cyclists [age (mean ± SD): 21.1 ± 2.1 yr; VO2max: 78.1 ± 5.3 mL·kg(-1)min(-1)] performed two incremental maximal tests separated by 48 h (one with C-rings, the other with Q-rings). Starting at 100 W, the workload was increased by 25 W every 3 min until volitional exhaustion. Maximal heart rate, power output and oxygen consumption were compared. Blood lactate was monitored throughout the test. After the incremental test, 4 intermittent 20-s maximal sprints with a 60-s recovery period in between were performed. Maximal isometric voluntary contractions were performed at rest and immediately after each 20-s maximal sprint, and the force and EMG RMS amplitude were recorded from the vastus medialis and vastus lateralis muscles. For the incremental exercise test, no significant differences were found in the maximal power output (P=0.12), oxygen consumption (P=0.39), and heart rate (P=0.32) between Q-rings and C-rings. Throughout the incremental test, lactate levels were comparable when using both the C-rings and Q-rings (P=0.47). During the short sprints, power output was 2.5-6.5% greater for Q-rings than for C-rings (P=0.22). The decline in EMG RMS amplitude observed during the incremental tests was comparable for Q-rings and C-rings (0.42). These findings indicate that the oval chainring design, presented here as "Q-rings", did not significantly influence the physiological response to an incremental exercise test as compared to a conventional chainring. Key pointsDuring the incremental exercise test, no significant differences were found in power output, oxygen consumption or heart rate between oval "Q-rings" and conventional chainrings.Over the course of the incremental test, blood lactate levels were comparable for the oval "Q-rings" and

Light-induced yellowing of selectively 13C-enriched dehydrogenation polymers (DHPs). Part 2, NMR assignments and photoyellowing of aromatic ring 1-, 3-, 4-, and 5-13C DHPs

Treesearch

Jim Parkas; Magnus Paulsson; Terashima Noritsugu; Ulla Westermark; Sally Ralph

2004-01-01

Light-induced yellowing of lignocellulosicmaterials has been studied using 13C-enriched DHP (dehydrogenation polymer), selectively 13C-enriched at positions 1, 3, 4, and 5 in the aromatic ring, and quantitative solution state 13C NMR spectroscopy. The NMR study confirmed the results of previous studies using side-chain labeled DHP, mainly that coniferyl alcohol end...

Pure moment testing for spinal biomechanics applications: Fixed versus sliding ring cable-driven test designs.

PubMed

Eguizabal, Johnny; Tufaga, Michael; Scheer, Justin K; Ames, Christopher; Lotz, Jeffrey C; Buckley, Jenni M

2010-05-07

In vitro multi-axial bending testing using pure moment loading conditions has become the standard in evaluating the effects of different types of surgical intervention on spinal kinematics. Simple, cable-driven experimental set-ups have been widely adopted because they require little infrastructure. Traditionally, "fixed ring" cable-driven experimental designs have been used; however, there have been concerns with the validity of this set-up in applying pure moment loading. This study involved directly comparing the loading state induced by a traditional "fixed ring" apparatus versus a novel "sliding ring" approach. Flexion-extension bending was performed on an artificial spine model and a single cadaveric test specimen, and the applied loading conditions to the specimen were measured with an in-line multiaxial load cell. The results showed that the fixed ring system applies flexion-extension moments that are 50-60% less than the intended values. This design also imposes non-trivial anterior-posterior shear forces, and non-uniform loading conditions were induced along the length of the specimen. The results of this study indicate that fixed ring systems have the potential to deviate from a pure moment loading state and that our novel sliding ring modification corrects this error in the original test design. This suggests that the proposed sliding ring design should be used for future in vitro spine biomechanics studies involving a cable-driven pure moment apparatus. Copyright 2010 Elsevier Ltd. All rights reserved.

Experimental Durability Testing of 4H SiC JFET Integrated Circuit Technology at 727 C

NASA Technical Reports Server (NTRS)

Spry, David; Neudeck, Phil; Chen, Liangyu; Chang, Carl; Lukco, Dorothy; Beheim, Glenn M

2016-01-01

We have reported SiC integrated circuits (IC's) with two levels of metal interconnect that have demonstrated prolonged operation for thousands of hours at their intended peak ambient operational temperature of 500 C [1, 2]. However, it is recognized that testing of semiconductor microelectronics at temperatures above their designed operating envelope is vital to qualification. Towards this end, we previously reported operation of a 4H-SiC JFET IC ring oscillator on an initial fast thermal ramp test through 727 C [3]. However, this thermal ramp was not ended until a peak temperature of 880 C (well beyond failure) was attained. Further experiments are necessary to better understand failure mechanisms and upper temperature limit of this extreme-temperature capable 4H-SiC IC technology. Here we report on additional experimental testing of custom-packaged 4H-SiC JFET IC devices at temperatures above 500 C. In one test, the temperature was ramped and then held at 727 C, and the devices were periodically measured until electrical failure was observed. A 4H-SiC JFET on this chip electrically functioned with little change for around 25 hours at 727 C before rapid increases in device resistance caused failure. In a second test, devices from our next generation 4H-SiC JFET ICs were ramped up and then held at 700 C (which is below the maximum deposition temperature of the dielectrics). Three ring oscillators functioned for 8 hours at this temperature before degradation. In a third experiment, an alternative die attach of gold paste and package lid was used, and logic circuit operation was demonstrated for 143.5 hours at 700 C.

Characterization of C-ring component assembly in flagellar motors from amino acid coevolution

PubMed Central

dos Santos, Ricardo Nascimento; Khan, Shahid

2018-01-01

Bacterial flagellar motility, an important virulence factor, is energized by a rotary motor localized within the flagellar basal body. The rotor module consists of a large framework (the C-ring), composed of the FliG, FliM and FliN proteins. FliN and FliM contacts the FliG torque ring to control the direction of flagellar rotation. We report that structure-based models constrained only by residue coevolution can recover the binding interface of atomic X-ray dimer complexes with remarkable accuracy (approx. 1 Å RMSD). We propose a model for FliM–FliN heterodimerization, which agrees accurately with homologous interfaces as well as in situ cross-linking experiments, and hence supports a proposed architecture for the lower portion of the C-ring. Furthermore, this approach allowed the identification of two discrete and interchangeable homodimerization interfaces between FliM middle domains that agree with experimental measurements and might be associated with C-ring directional switching dynamics triggered upon binding of CheY signal protein. Our findings provide structural details of complex formation at the C-ring that have been difficult to obtain with previous methodologies and clarify the architectural principle that underpins the ultra-sensitive allostery exhibited by this ring assembly that controls the clockwise or counterclockwise rotation of flagella. PMID:29892378

16 CFR Figure 1 to Part 1213 - Wedge Block for Tests in § 1213.4(a), (b), and (c)

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Wedge Block for Tests in § 1213.4(a), (b), and (c) 1 Figure 1 to Part 1213 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER... 1 to Part 1213—Wedge Block for Tests in § 1213.4(a), (b), and (c) ER22DE99.007 ...

The plasma environment, charge state, and currents of Saturn's C and D rings

NASA Technical Reports Server (NTRS)

Wilson, G. R.

1991-01-01

The charge state and associated currents of Saturn's C an D rings are studied by modeling the flow of ionospheric plasma from the mid- to low-latitude ionosphere to the vicinity of the rings. It is found that the plasma density near the C and D rings, at a given radial location, will experience a one to two order of magnitude diurnal variation. The surface charge density (SCD) of these rings can show significant radial and azimuthal variations due mainly to variation in the plasma density. The SCD also depends on structural features of the rings such as thickness and the nature of the particle size distribution. The associated azimuthal currents carried by these rings also show large diurnal variations resulting in field-aligned currents which close in the ionosphere. The resulting ionospheric electric field will probably not produce a significant amount of plasma convection in the topside ionosphere and inner plasmasphere.

Nardo Ring, Italy

NASA Technical Reports Server (NTRS)

2008-01-01

The Nardo Ring is a striking visual feature from space, and astronauts have photographed it several times. The Ring is a race car test track; it is 12.5 kilometers long and steeply banked to reduce the amount of active steering needed by drivers. The Nardo Ring lies in a remote area on the heel of Italy's 'boot,' 50 kilometers east of the naval port of Taranto. The Ring encompasses a number of active (green) and fallow (brown to dark brown) agricultural fields. In this zone of intensive agriculture, farmers gain access to their fields through the Ring via a series of underpasses. Winding features within the southern section of the Ring appear to be smaller, unused race tracks.

The image covers an area of 18.8 x 16.4 km, was acquired on August 17. 2007, and is located at 49.3 degrees north latitude, 17.8 degrees east longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Metal ring on 4th or 5th finger markedly increases both cardiac troponin I at left ventricle and cancer-related parameters such as oncogen C-fosAb2 & integrin α₅β₁[corrected] by 4-12 times. Thus these metal rings appear to promote both heart problems & cancer.

PubMed

Omura, Yoshiaki; Hines, Howard; Jones, Marilyn; O'Young, Brian; Duvvi, Harsha; Lu, Dominic P; Pallos, Andrew; Shimotsuura, Yasuhiro; Ohki, Motomu

2010-01-01

We examined patients wearing a metal ring on the left 4th finger with abnormally increased Cardiac Troponin I (which is known to increase in the presence of myocardial injury or left ventricular hypertrophy) of 5-14ng BDORT units (depending on the ring and individual) at left ventricle compared with normal value of 1ng BDORT units or less. Although shape of the ECG does not change significantly regardless of whether metal rings are on or not, when rings are on, the Bi-Digital O-Ring Test evaluation of trace of ECG revealed "Vulnerable Period of Rising Part of T-wave" of ECG waves (which correspond to the left ventricle and AV node) become abnormal with increased Cardiac Troponin I. DHEA in various parts of the body reduced significantly and maximum decrease in DHEA was found when metal ring was on the left 4th and 5th fingers. Telomere reduced with each of the 5 fingers, but the 2nd, 4th, and 5th fingers produced the maximum reduction of telomere. When metal ring was inserted onto the left 1st finger and left 2nd finger, Cardiac Troponin I did not change significantly. Additional abnormality was found when patients with cancer wore metal ring(s); namely both Cardiac Troponin I and cancer parameters, such as Integrin α₅β₁[corrected] and Oncogen C-fos Ab2, increase anywhere between 4-12 times. However, when the ring was cut, creating a 1mm or longer empty space, no increase in cancer markers and Cardiac Troponin I were observed. Similar findings were found with metal bracelets.

Saturn's Rings and Associated Ring Plasma Cavity: Evidence for Slow Ring Erosion

NASA Technical Reports Server (NTRS)

Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.

2017-01-01

We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C- ring, leading to field-aligned plasma transport to Saturns ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma fountains. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >10(exp 9) years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

Saturn's rings and associated ring plasma cavity: Evidence for slow ring erosion

NASA Astrophysics Data System (ADS)

Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.

2017-08-01

We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C-ring, leading to field-aligned plasma transport to Saturn's ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma 'fountains'. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >109 years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

Pure moment testing for spinal biomechanics applications: fixed versus 3D floating ring cable-driven test designs.

PubMed

Tang, Jessica A; Scheer, Justin K; Ames, Christopher P; Buckley, Jenni M

2012-02-23

Pure moment testing has become a standard protocol for in vitro assessment of the effect of surgical techniques or devices on the bending rigidity of the spine. Of the methods used for pure moment testing, cable-driven set-ups are popular due to their low requirements and simple design. Fixed loading rings are traditionally used in conjunction with these cable-driven systems. However, the accuracy and validity of the loading conditions applied with fixed ring designs have raised some concern, and discrepancies have been found between intended and prescribed loading conditions for flexion-extension. This study extends this prior work to include lateral bending and axial torsion, and compares this fixed ring design with a novel "3D floating ring" design. A complete battery of multi-axial bending tests was conducted with both rings in multiple different configurations using an artificial lumbar spine. Applied moments were monitored and recorded by a multi-axial load cell at the base of the specimen. Results indicate that the fixed ring design deviates as much as 77% from intended moments and induces non-trivial shear forces (up to 18 N) when loaded to a non-destructive maximum of 4.5 Nm. The novel 3D floating ring design largely corrects the inherent errors in the fixed ring design by allowing additional directions of unconstrained motion and producing uniform loading conditions along the length of the specimen. In light of the results, it is suggested that the 3D floating ring set-up be used for future pure moment spine biomechanics applications using a cable-driven apparatus. Copyright © 2012 Elsevier Ltd. All rights reserved.

Copper Causes Regiospecific Formation of C4F8-Containing Six-Membered Rings and their Defluorination/Aromatization to C4F4-Containing Rings in Triphenylene/1,4-C4F8I2 Reactions

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

Rippy, Kerry C.; Bukovsky, Eric V.; Clikeman, Tyler T.

The presence of Cu in reactions of triphenylene (TRPH) and 1,4-C4F8I2 at 360 °C led to regiospecific substitution of TRPH ortho C(β) atoms to form C4F8-containing rings, completely suppressing substitution on C(α) atoms. In addition, Cu caused selective reductive-defluorination/aromatization (RD/A) to form C4F4- containing aromatic rings. Without Cu, the reactions of TRPH and 1,4- C4F8I2 were not regiospecific and no RD/A was observed. These results, supported by DFT calculations, are the first examples of Cupromoted (i) regiospecific perfluoroannulation, (ii) preparative C–F activation, and (iii) RD/A. HPLC-purified products were characterized by X-ray diffraction, low-temperature PES, and 1H/19F NMR.

Variations of vessel diameter and δ13C in false rings of Arbutus unedo L. reflect different environmental conditions.

PubMed

Battipaglia, Giovanna; De Micco, Veronica; Brand, Willi A; Linke, Petra; Aronne, Giovanna; Saurer, Matthias; Cherubini, Paolo

2010-12-01

Woody species in Mediterranean ecosystems form intra-annual density fluctuations (IADFs) in tree rings in response to changes in environmental conditions, especially water availability. Dendrochronology, quantitative wood anatomy and high-resolution isotopic analysis (using a laser ablation technique) were used to characterize IADFs in Arbutus unedo shrubs grown on two sites with different water availability on the island of Elba (Italy). Our findings show that IADF characterization can provide information about the relationship between environmental factors and tree growth at the seasonal level. At the more xeric site, IADFs mainly located in the early and middle parts of the annual ring, showed a decrease in vessel size and an increase in δ(13) C as a result of drought deficit. Opposite trends were found at the more mesic site, with IADFs located at the end of the ring and associated with a lower δ(13) C. Moreover, at the first site, IADFs are induced by drought deficit, while at the second site IADFs are linked with the regrowth in the last part of the growing season triggered by favourable wet conditions. This combined approach is a promising way for dating problematic wood samples and interpreting the phenomena that trigger the formation of IADFs in the Mediterranean environment. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

The future of the application of the Bi-Digital O-Ring Test in Sports Psychology.

PubMed

Ozerkan, Kemal Nuri

2005-01-01

The Bi-Digital O-Ring Test, originally developed by Dr. Omura, utilizes changes in the degree of strength of voluntary movements of muscles of the fingers under a definite muscle tonus, making Bi-Digital O-Rings, as an indicator of pathology in the body. Research in Sports Psychology can use the classical measurement methods and Bi-Digital O-Ring Test method comparatively and thus produce new findings regarding the reliability and certainty of the Bi-Digital O-Ring Test test. It seems probable that by using the non-invasive Bi-Digital O-Ring Test test, it is possible to measure enzymes, hormones and neuro-transmitters instantaneously and assess a sports person's actual psychological and physiological performance, and thereby help them reach their peak performance levels during both exercise and competitions.

Fatigue Testing of Ring-Stiffened Traffic Signal Structures.

DOT National Transportation Integrated Search

2010-10-09

Based on in-service inspection of poles with traditional designs, the inventory of Wyoming Department of Transportation ?WYDOT? exhibited approximately a one-third cracking rate. A ring-stiffened connection is presently used. Sixteen fatigue tests we...

C-shaped specimen plane strain fracture toughness tests. [metallic materials

NASA Technical Reports Server (NTRS)

Buzzard, R. T.; Fisher, D. M.

1977-01-01

Test equipment, procedures, and data obtained in the evaluation of C-shaped specimens are presented. Observations reported on include: specimen preparation and dimensional measurement; modifications to the standard ASTM E 399 displacement gage, which permit punch mark gage point engagement; and a measurement device for determining the interior and exterior radii of ring segments. Load displacement ratios were determined experimentally which agreed with analytically determined coefficients for three different gage lengths on the inner surfaces of radially-cracked ring segments.

14 CFR Appendix C to Part 25 - Appendix C to Part 25

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Appendix C to Part 25 C Appendix C to Part... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Pt. 25, App. C Appendix C to Part 25 Part I—Atmospheric....062 EC28SE91.063 (c) Takeoff maximum icing. The maximum intensity of atmospheric icing conditions for...

14 CFR Appendix C to Part 25 - Appendix C to Part 25

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Appendix C to Part 25 C Appendix C to Part... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Pt. 25, App. C Appendix C to Part 25 Part I—Atmospheric....062 EC28SE91.063 (c) Takeoff maximum icing. The maximum intensity of atmospheric icing conditions for...

14 CFR Appendix C to Part 25 - Appendix C to Part 25

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Appendix C to Part 25 C Appendix C to Part... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Pt. 25, App. C Appendix C to Part 25 Part I—Atmospheric....062 EC28SE91.063 (c) Takeoff maximum icing. The maximum intensity of atmospheric icing conditions for...

Modified ring stretch tensile testing of Zr-1Nb cladding

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

Cohen, A.B.; Majumdar, S.; Ruther, W.E.

1998-03-01

In a round robin effort between the US Nuclear Regulatory Commission, Institut de Protection et de Surete Nucleaire in France, and the Russian Research Centre-Kurchatov Institute, Argonne National Laboratory conducted 16 modified ring stretch tensile tests on unirradiated samples of zr-1Nb cladding, which is used in Russian VVER reactors. Test were conducted at two temperatures (25 and 400 C) and two strain rates (0.001 and 1 s{sup {minus}1}). At 25 C and 0.001 s{sup {minus}1}, the yield strength (YS), ultimate tensile strength (UTS), uniform elongation (UE), and total elongation (TE) were 201 MPa, 331 MPa, 18.2%, and 57.6%, respectively. Atmore » 400 C and 0.001 s{sup {minus}1}, the YS, UTS, UE, and TE were 109 MPa, 185 MPa, 15.4%, and 67.7%, respectively. Finally, at 400 C and 1 s{sup {minus}1}, the YS, UTS, UE, and TE were 134 MPa, 189 MPa, 18.9%, and 53.4%, respectively. The high strain rate tests at room temperature were not successful. Test results proved to be very sensitive to the amount of lubrication used on the inserts; because of the large contact area between the inserts and specimen, too little lubrication leads to significantly higher strengths and lower elongations being reported. It is also important to note that only 70 to 80% of the elongation takes place in the gauge section, depending on specimen geometry. The appropriate percentage can be estimated from a simple model or can be calculated from finite-element analysis.« less

DOD SPHERES-RINGS Test Session

NASA Image and Video Library

2013-11-04

ISS037-E-025915 (4 Nov. 2013) --- In the International Space Station?s Kibo laboratory, NASA astronaut Michael Hopkins, Expedition 37 flight engineer, conducts a session with a pair of bowling-ball-sized free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. Surrounding the two SPHERES mini-satellites is ring-shaped hardware known as the Resonant Inductive Near-field Generation System, or RINGS. SPHERES-RINGS seeks to demonstrate wireless power transfer between satellites at a distance for enhanced operations.

EASY: a simple tool for simultaneously removing background, deadtime and acoustic ringing in quantitative NMR spectroscopy--part I: basic principle and applications.

PubMed

Jaeger, Christian; Hemmann, Felix

2014-01-01

Elimination of Artifacts in NMR SpectroscopY (EASY) is a simple but very effective tool to remove simultaneously any real NMR probe background signal, any spectral distortions due to deadtime ringdown effects and -specifically- severe acoustic ringing artifacts in NMR spectra of low-gamma nuclei. EASY enables and maintains quantitative NMR (qNMR) as only a single pulse (preferably 90°) is used for data acquisition. After the acquisition of the first scan (it contains the wanted NMR signal and the background/deadtime/ringing artifacts) the same experiment is repeated immediately afterwards before the T1 waiting delay. This second scan contains only the background/deadtime/ringing parts. Hence, the simple difference of both yields clean NMR line shapes free of artefacts. In this Part I various examples for complete (1)H, (11)B, (13)C, (19)F probe background removal due to construction parts of the NMR probes are presented. Furthermore, (25)Mg EASY of Mg(OH)2 is presented and this example shows how extremely strong acoustic ringing can be suppressed (more than a factor of 200) such that phase and baseline correction for spectra acquired with a single pulse is no longer a problem. EASY is also a step towards deadtime-free data acquisition as these effects are also canceled completely. EASY can be combined with any other NMR experiment, including 2D NMR, if baseline distortions are a big problem. © 2013 Published by Elsevier Inc.

Orion MPCV Service Module Avionics Ring Pallet Testing, Correlation, and Analysis

NASA Technical Reports Server (NTRS)

Staab, Lucas; Akers, James; Suarez, Vicente; Jones, Trevor

2012-01-01

The NASA Orion Multi-Purpose Crew Vehicle (MPCV) is being designed to replace the Space Shuttle as the main manned spacecraft for the agency. Based on the predicted environments in the Service Module avionics ring, an isolation system was deemed necessary to protect the avionics packages carried by the spacecraft. Impact, sinusoidal, and random vibration testing were conducted on a prototype Orion Service Module avionics pallet in March 2010 at the NASA Glenn Research Center Structural Dynamics Laboratory (SDL). The pallet design utilized wire rope isolators to reduce the vibration levels seen by the avionics packages. The current pallet design utilizes the same wire rope isolators (M6-120-10) that were tested in March 2010. In an effort to save cost and schedule, the Finite Element Models of the prototype pallet tested in March 2010 were correlated. Frequency Response Function (FRF) comparisons, mode shape and frequency were all part of the correlation process. The non-linear behavior and the modeling the wire rope isolators proved to be the most difficult part of the correlation process. The correlated models of the wire rope isolators were taken from the prototype design and integrated into the current design for future frequency response analysis and component environment specification.

16 CFR Figure 1 to Part 1513 - Wedge Block for Tests in § 1513.4 (a), (b), and (c)

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Wedge Block for Tests in § 1513.4 (a), (b), and (c) 1 Figure 1 to Part 1513 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL... Block for Tests in § 1513.4 (a), (b), and (c) ER22DE99.002 ...

14 CFR Appendix C to Part 151 - Appendix C to Part 151

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Appendix C to Part 151 C Appendix C to Part...) AIRPORTS FEDERAL AID TO AIRPORTS Pt. 151, App. C Appendix C to Part 151 There is set forth below an... Items 1. Maintenance-type work, including: (a) Seal coats. (b) Crack filling. (c) Resealing joints. (d...

SRB attach ring phenolic TPS fishtail seal evaluation tests

NASA Technical Reports Server (NTRS)

Karu, Z. S.

1982-01-01

The SRB attach ring is thermally protected with layered phenolic cloth fairings that are fastened to the ring. The gap between the fairings and the motor case is closed off with a rubber seal of a fishtail cross sectional shape bonded to the phenolic. On both the STS-1 and STS-2 flights this gap was discovered to vary anywhere from an intended gap of 0.375 in. to an actual measured gap of 0.60 in. due to tolerances. Tests were conducted with and without a 0.25 in. thick cork shim placed under the seal with a 0.60 in. gap under the phenolic TPS to determine and compare the performance of the seal in the two different configurations. To alleviate the difficult and costly procedure of installing the cork shim under the seal, especially after phenolic TPS mounting on the attach ring, large fishtail seals of idential Elder gray silicon material and two different hardnesses were tested. A similar matrix of tests was conducted with this new large fishtail seal, and seals with both type hardnesses performed well regardless of whether or not the seal was bonded in the phenolic at the front of the seal groove. Similar results had been obtained with the original small fishtail seal which performed adequately with the 0.25 in. cork shim under it.

Development of dapivirine vaginal ring for HIV prevention.

PubMed

Devlin, Bríd; Nuttall, Jeremy; Wilder, Susan; Woodsong, Cynthia; Rosenberg, Zeda

2013-12-01

In the continuing effort to develop effective HIV prevention methods for women, a vaginal ring containing the non-nucleoside reverse transcriptase inhibitor dapivirine is currently being tested in two safety and efficacy trials. This paper reviews dapivirine ring's pipeline development process, including efforts to determine safe and effective dosing levels as well as identify delivery platforms with the greatest likelihood of success for correct and consistent use. Dapivirine gel and other formulations were developed and tested in preclinical and clinical studies. Multiple vaginal ring prototypes were also tested, resulting in the current ring design as well as additional designs under consideration for future testing. Efficacy results from clinical trials are expected in 2015. Through ongoing consultations with national regulatory authorities, licensure requirements for dapivirine vaginal ring approval have been defined. This article is based on a presentation at the "Product Development Workshop 2013: HIV and Multipurpose Prevention Technologies," held in Arlington, Virginia on February 21-22, 2013. It forms part of a special supplement to Antiviral Research. Copyright © 2013 Elsevier B.V. All rights reserved.

Water impact test of aft skirt end ring, and mid ring segments of the Space Shuttle Solid Rocket Booster

NASA Technical Reports Server (NTRS)

1983-01-01

The results of water impact loads tests using aft skirt end ring, and mid ring segments of the Space Shuttle Solid Rocket Booster (SRB) are examined. Dynamic structural response data is developed and an evaluation of the model in various configurations is presented. Impact velocities are determined for the SRB with the larger main chute system. Various failure modes are also investigated.

Signal and power roll ring testing update

NASA Technical Reports Server (NTRS)

Smith, Dennis W.

1989-01-01

The development of the roll ring as a long-life, low-torque alternative to the slip ring is discussed. A roll ring consists of one or more circular flexures captured by their own spring force in the annular space between two concentric conductors or contact rings. The advantages of roll rings over other types of electrical transfer devices are: extremely low drag torque, high transfer efficiencies in high-power configurations, extremely low wear debris generation, long life, and low weight for high-power applications.

High-resolution imaging of Saturn's main rings during the Cassini Ring-Grazing Orbits and Grand Finale

NASA Astrophysics Data System (ADS)

Tiscareno, M. S.

2017-12-01

Cassini is ending its spectacular 13-year mission at Saturn with a two-part farewell, during which it has obtained the sharpest and highest-fidelity images ever taken of Saturn's rings. From December 2016 to April 2017, the spacecraft executed 20 near-polar orbits that passed just outside the outer edge of the main rings; these "Ring-Grazing Orbits" provided the mission's best viewing of the A and F rings and the outer B ring. From April to September 2017, the spacecraft is executing 22 near-polar orbits that pass between the innermost D ring and the planet's clouds; this "Grand Finale" provides the mission's best viewing of the C and D rings and the inner B ring. 1) Clumpy BeltsClumpy structure called "straw" was previously observed in parts of the main rings [Porco et al. 2005, Science]. New images show this structure with greater clarity. More surprisingly, new images reveal strong radial variations in the degree and character of clumpiness, which are probably an index for particle properties and interactions. Belts with different clumpiness characteristics are often adjacent to each other and not easily correlated with other ring characteristics. 2) PropellersA "propeller" is a local disturbance in the ring created by an embedded moon [Tiscareno et al. 2006, Nature; 2010, ApJL]. Cassini has observed two classes of propellers: small propellers that swarm in the "Propeller Belts" of the mid-A ring, and "Giant Propellers" whose individual orbits can be tracked in the outer A ring. Both are shown in unprecedented detail in new images. Targeted flybys of Giant Propellers were executed on both the lit and unlit sides of the ring (see figure), yielding enhanced ability to convert brightness to optical depth and surface density. 3) Impact Ejecta CloudsBeing a large and delicate system, Saturn's rings function as a detector of their planetary environment. Cassini images of impact ejecta clouds in the rings previously constrained the population of decimeter

The c15 ring of the Spirulina platensis F-ATP synthase: F1/F0 symmetry mismatch is not obligatory

PubMed Central

Pogoryelov, Denys; Yu, Jinshu; Meier, Thomas; Vonck, Janet; Dimroth, Peter; Muller, Daniel J

2005-01-01

The oligomeric c ring of the F-ATP synthase from the alkaliphilic cyanobacterium Spirulina platensis was isolated and characterized. Mass spectroscopy analysis indicated a mass of 8,210 Da, reflecting that of a c monomer. The mass increased by 206 Da after treatment with the c-subunit-specific inhibitor dicyclohexylcarbodiimide (DCCD), which indicated modification of the ion-binding carboxylate by DCCD. Atomic force microscopy topographs of c rings from S. platensis showed 15 symmetrically assembled subunits. The c15-mer reported here is the largest c ring that is isolated and does not show the classical c-ring mismatch to the three-fold symmetry of the F1 domain. PMID:16170308

Jupiter's Main Ring/Ring Halo

NASA Technical Reports Server (NTRS)

1997-01-01

A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (28.5 miles) per picture element (pixel) along Jupiter's rings. Because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun; the ring was approximately 2.3 million kilometers (1.4 million miles) away. The arc on the far right of the image is produced when sunlight is scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

Jupiter's ring system is composed of three parts - - a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, outside the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the figure's far left side. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the ring's ansa (top image). A faint mist of particles can be seen above and below the main rings. This vertically extended 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces pushing the smallest grains out of the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. To accentuate faint features in the bottom image of the ring halo, different brightnesses are shown through color. Brightest features are white or yellow and the

Copper(I)-Catalyzed Chemoselective Coupling of Cyclopropanols with Diazoesters: Ring-Opening C-C Bond Formations.

PubMed

Zhang, Hang; Wu, Guojiao; Yi, Heng; Sun, Tong; Wang, Bo; Zhang, Yan; Dong, Guangbin; Wang, Jianbo

2017-03-27

Reported herein is an exceptional chemoselective ring-opening/C(sp 3 )-C(sp 3 ) bond formation in the copper(I)-catalyzed reaction of cyclopropanols with diazo esters. The conventional O-H insertion product is essentially suppressed by judicious choice of reaction conditions. DFT calculations provide insights into the reaction mechanism and the rationale for this unusual chemoselectivity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assembly of the MreB-associated cytoskeletal ring of Escherichia coli.

PubMed

Vats, Purva; Shih, Yu-Ling; Rothfield, Lawrence

2009-04-01

The Escherichia coli actin homologue MreB is part of a helical cytoskeletal structure that winds around the cell between the two poles. It has been shown that MreB redistributes during the cell cycle to form circumferential ring structures that flank the cytokinetic FtsZ ring and appear to be associated with division and segregation of the helical cytoskeleton. We show here that the MreB cytoskeletal ring also contains the MreC, MreD, Pbp2 and RodA proteins. Assembly of MreB, MreC, MreD and Pbp2 into the ring structure required the FtsZ ring but no other known components of the cell division machinery, whereas assembly of RodA into the cytoskeletal ring required one or more additional septasomal components. Strikingly, MreB, MreC, MreD and RodA were each able to independently assemble into the cytoskeletal ring and coiled cytoskeletal structures in the absence of any of the other ring components. This excludes the possibility that one or more of these proteins acts as a scaffold for incorporation of the other proteins into these structures. In contrast, incorporation of Pbp2 required the presence of MreC, which may provide a docking site for Pbp2 entry.

Novel High Temperature Capacitive Pressure Sensor Utilizing SiC Integrated Circuit Twin Ring Oscillators

NASA Technical Reports Server (NTRS)

Scardelletti, M.; Neudeck, P.; Spry, D.; Meredith, R.; Jordan, J.; Prokop, N.; Krasowski, M.; Beheim, G.; Hunter, G.

2017-01-01

This paper describes initial development and testing of a novel high temperature capacitive pressure sensor system. The pressure sensor system consists of two 4H-SiC 11-stage ring oscillators and a SiCN capacitive pressure sensor. One oscillator has the capacitive pressure sensor fixed at one node in its feedback loop and varies as a function of pressure and temperature while the other provides a pressure-independent reference frequency which can be used to temperature compensate the output of the first oscillator. A two-day repeatability test was performed up to 500C on the oscillators and the oscillator fundamental frequency changed by only 1. The SiCN capacitive pressure sensor was characterized at room temperature from 0 to 300 psi. The sensor had an initial capacitance of 3.76 pF at 0 psi and 1.75 pF at 300 psi corresponding to a 54 change in capacitance. The integrated pressure sensor system was characterized from 0 to 300 psi in steps of 50 psi over a temperature range of 25 to 500C. The pressure sensor system sensitivity was 0.113 kHzpsi at 25C and 0.026 kHzpsi at 500C.

Dual RING E3 Architectures Regulate Multiubiquitination and Ubiquitin Chain Elongation by APC/C.

PubMed

Brown, Nicholas G; VanderLinden, Ryan; Watson, Edmond R; Weissmann, Florian; Ordureau, Alban; Wu, Kuen-Phon; Zhang, Wei; Yu, Shanshan; Mercredi, Peter Y; Harrison, Joseph S; Davidson, Iain F; Qiao, Renping; Lu, Ying; Dube, Prakash; Brunner, Michael R; Grace, Christy R R; Miller, Darcie J; Haselbach, David; Jarvis, Marc A; Yamaguchi, Masaya; Yanishevski, David; Petzold, Georg; Sidhu, Sachdev S; Kuhlman, Brian; Kirschner, Marc W; Harper, J Wade; Peters, Jan-Michael; Stark, Holger; Schulman, Brenda A

2016-06-02

Protein ubiquitination involves E1, E2, and E3 trienzyme cascades. E2 and RING E3 enzymes often collaborate to first prime a substrate with a single ubiquitin (UB) and then achieve different forms of polyubiquitination: multiubiquitination of several sites and elongation of linkage-specific UB chains. Here, cryo-EM and biochemistry show that the human E3 anaphase-promoting complex/cyclosome (APC/C) and its two partner E2s, UBE2C (aka UBCH10) and UBE2S, adopt specialized catalytic architectures for these two distinct forms of polyubiquitination. The APC/C RING constrains UBE2C proximal to a substrate and simultaneously binds a substrate-linked UB to drive processive multiubiquitination. Alternatively, during UB chain elongation, the RING does not bind UBE2S but rather lures an evolving substrate-linked UB to UBE2S positioned through a cullin interaction to generate a Lys11-linked chain. Our findings define mechanisms of APC/C regulation, and establish principles by which specialized E3-E2-substrate-UB architectures control different forms of polyubiquitination. Copyright © 2016 Elsevier Inc. All rights reserved.

Electro-optical hybrid slip ring

NASA Astrophysics Data System (ADS)

Hong, En

2005-11-01

The slip ring is a rotary electrical interface, collector, swivel or rotary joint. It is a physical system that can perform continuous data transfer and data exchange between a stationary and a rotating structure. A slip ring is generally used to transfer data or power from an unrestrained, continuously rotating electro-mechanical system in real-time, thereby simplifying operations and eliminating damage-prone wires dangling from moving joints. Slip rings are widely used for testing, evaluating, developing and improving various technical equipment and facilities with rotating parts. They are widely used in industry, especially in manufacturing industries employing turbo machinery, as in aviation, shipbuilding, aerospace, defense, and in precise facilities having rotating parts such as medical Computerized Tomography (CT) and MRI scanners and so forth. Therefore, any improvement in slip ring technology can impact large markets. Research and development in this field will have broad prospects long into the future. The goal in developing the current slip ring technology is to improve and increase the reliability, stability, anti-interference, and high data fidelity between rotating and stationary structures. Up to now, there have been numerous approaches used for signal and data transfer utilizing a slip ring such as metal contacts, wires, radio transmission, and even liquid media. However, all suffer from drawbacks such as data transfer speed limitations, reliability, stability, electro-magnetic interference and durability. The purpose of the current research is to break through these basic limitations using an optical solution, thereby improving performance in current slip ring applications. This dissertation introduces a novel Electro-Optical Hybrid Slip Ring technology, which makes "through the air" digital-optical communication between stationary and rotating systems a reality with high data transfer speed, better reliability and low interference susceptibility

Switching from Controlled Ring-Opening Polymerization (cROP) to Controlled Ring-Closing Depolymerization (cRCDP) by Adjusting the Reaction Parameters That Determine the Ceiling Temperature

PubMed Central

2016-01-01

Full control over the ceiling temperature (Tc) enables a selective transition between the monomeric and polymeric state. This is exemplified by the conversion of the monomer 2-allyloxymethyl-2-ethyl-trimethylene carbonate (AOMEC) to poly(AOMEC) and back to AOMEC within 10 h by controlling the reaction from conditions that favor ring-opening polymerization (Tc > T0) (where T0 is the reaction temperature) to conditions that favor ring-closing depolymerization (Tc < T0). The ring-closing depolymerization (RCDP) mirrors the polymerization behavior with a clear relation between the monomer concentration and the molecular weight of the polymer, indicating that RCDP occurs at the chain end. The Tc of the polymerization system is highly dependent on the nature of the solvent, for example, in toluene, the Tc of AOMEC is 234 °C and in acetonitrile Tc = 142 °C at the same initial monomer concentration of 2 M. The control over the monomer to polymer equilibrium sets new standards for the selective degradation of polymers, the controlled release of active components, monomer synthesis and material recycling. In particular, the knowledge of the monomer to polymer equilibrium of polymers in solution under selected environmental conditions is of paramount importance for in vivo applications, where the polymer chain is subjected to both high dilution and a high polarity medium in the presence of catalysts, that is, very different conditions from which the polymer was formed. PMID:27783494

Identification of Saturn-driven bending waves in Saturn's inner C ring

NASA Astrophysics Data System (ADS)

French, Richard; Colwell, Joshua; Nicholson, Phillip; Marouf, Essam; McGhee-French, Colleen; Hedman, Matthew

2016-07-01

Saturn's C ring is host to more than a dozen wavelike features whose detailed nature has been a mystery since their discovery in high-resolution Voyager radio occultations of the rings. Rosen et al. (1991 Icarus 93, 25) enumerated several of these, and the list was augmented by Baillié et al. (2011 Icarus 216, 292), based on a detailed analysis of Cassini UVIS stellar occultation profiles. Recently, Hedman and Nicholson (2013 Astron. J. 146, 12; 2014 MNRAS 444, 1369) were able to identify the wavenumbers and pattern speeds for several of the waves. They showed that several Outer Lindblad Resonances (OLR) density waves had properties that were in general quite consistent with the predictions of Marley and Porco (1993 Icarus, 106, 508) and Marley (2014 Icarus, 234, 194) that Saturn's acoustic oscillations had pattern speeds with corresponding resonance radii in the C ring. Hedman and Nicholson also identified a set of Inner Lindblad Resonance density waves with pattern speeds very close to Saturn's rotation period. Finally, French et al. (2016 Icarus, in press) identified an inward-propagating m=2 wave in the Maxwell Ringlet. These new identifications ushered in the field of Kronoseismology -- the probing of the nature of Saturn's interior from the analysis of Saturn-driven waves in the rings. Here, we report the identification of six additional wave features, all in the inner C ring, from Cassini occultation measurements. Two of the waves are OLRs: Baillié feature #5 (B1 = W76.022 (i.e., r=76022 km)) with wavenumber m=-9, and Baillié #9 (B9 = W76.435) with m=-2. The first of these is presumably Saturn-driven, but of unknown origin; W76.435 fits very nicely in the pattern predicted by Marley (2014) for an m=l-2, q=2 internal oscillation. We also report the identification of a new class of Saturn-driven waves: B1 (W74.666), B3 (W74.936), B4 (W74.941), and B6 (W76.234) are all bending waves at Outer Vertical Resonances (OVR) with wavenumbers between m=-4 and m=-9

20 CFR Appendix C to Part 718 - Blood-Gas Tables

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Blood-Gas Tables C Appendix C to Part 718... DUE TO PNEUMOCONIOSIS Pt. 718, App. C Appendix C to Part 718—Blood-Gas Tables The following tables set... of the following tables are met: (1) For arterial blood-gas studies performed at test sites up to 2...

20 CFR Appendix C to Part 718 - Blood-Gas Tables

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Blood-Gas Tables C Appendix C to Part 718... DUE TO PNEUMOCONIOSIS Pt. 718, App. C Appendix C to Part 718—Blood-Gas Tables The following tables set... of the following tables are met: (1) For arterial blood-gas studies performed at test sites up to 2...

Conformity of modified O-ring test and maximal pinch strength for cross tape application direction.

PubMed

Lee, Jung-Hoon; Choi, Hyun-Su

2018-06-01

Although cross tape has recently been used by clinicians for various musculoskeletal conditions, scientific studies on the direction of cross tape application are lacking. The present study aimed to investigate whether the direction of cross tape application affected the outcomes of the modified O-ring test and maximal pinch strength using a pinch gauge and the conformity between these 2 tests when cross tape was applied to the forearm muscles of individuals with no upper extremity pain and no restriction of joint range of motion.This study used a single-blinding crossover design. The subjects comprised 39 adults (16 men and 23 women). Cross tape was applied to the dominant hand so that the 4 rows were at an angle of 45° to the right or left of the direction of the flexor digitorum superficialis muscle fibers, and then the subjects underwent a modified O-ring test and a test of maximal pinch strength using a pinch gauge. Both tests were performed in both directions, and the order of the directions and tests was randomized. SPSS 18.0 was used for statistical analysis. Cohen's kappa coefficient was used to analyze the conformity of the results from the 2 tests. The statistical significance level was P < .05. A positive response in the modified O-ring test and maximal pinch strength were both affected by cross tape direction. The modified O-ring test and maximal pinch strength using pinch gauge results were in agreement (P < .00), and the kappa coefficient was significant at 1.00. The direction of cross tape application that produced a positive response in the modified O-ring test also produced greater maximal pinch strength. Thus, we propose that when applying cross tape to muscles, the direction of the 4 lines of the cross tape should be 45° relative to the direction of the muscle fibers, toward the side that produces a positive response in the modified O-ring test or produces the greatest maximal pinch strength using a pinch gauge.

The c-ring stoichiometry of ATP synthase is adapted to cell physiological requirements of alkaliphilic Bacillus pseudofirmus OF4

PubMed Central

Preiss, Laura; Klyszejko, Adriana L.; Hicks, David B.; Liu, Jun; Fackelmayer, Oliver J.; Yildiz, Özkan; Krulwich, Terry A.; Meier, Thomas

2013-01-01

The c-rings of ATP synthases consist of individual c-subunits, all of which harbor a conserved motif of repetitive glycine residues (GxGxGxG) important for tight transmembrane α-helix packing. The c-ring stoichiometry determines the number of ions transferred during enzyme operation and has a direct impact on the ion-to-ATP ratio, a cornerstone parameter of cell bioenergetics. In the extreme alkaliphile Bacillus pseudofirmus OF4, the glycine motif is replaced by AxAxAxA. We performed a structural study on two mutants with alanine-to-glycine changes using atomic force microscopy and X-ray crystallography, and found that mutants form smaller c12 rings compared with the WT c13. The molar growth yields of B. pseudofirmus OF4 cells on malate further revealed that the c12 mutants have a considerably reduced capacity to grow on limiting malate at high pH. Our results demonstrate that the mutant ATP synthases with either c12 or c13 can support ATP synthesis, and also underscore the critical importance of an alanine motif with c13 ring stoichiometry for optimal growth at pH >10. The data indicate a direct connection between the precisely adapted ATP synthase c-ring stoichiometry and its ion-to-ATP ratio on cell physiology, and also demonstrate the bioenergetic challenges and evolutionary adaptation strategies of extremophiles. PMID:23613590

C-shaped diastereomers containing cofacial thiophene-substituted quinoxaline rings: synthesis, photophysical properties, and X-ray crystallography.

PubMed

DeBlase, Catherine R; Finke, Ryan T; Porras, Jonathan A; Tanski, Joseph M; Nadeau, Jocelyn M

2014-05-16

Synthesis and characterization of two diastereomeric C-shaped molecules containing cofacial thiophene-substituted quinoxaline rings are described. A previously known bis-α-diketone was condensed with an excess of 4-bromo-1,2-diaminobenzene in the presence of zinc acetate to give a mixture of two C-shaped diastereomers with cofacial bromine-substituted quinoxaline rings. After chromatographic separation, thiophene rings were installed by a microwave-assisted Suzuki coupling reaction, resulting in highly emissive diastereomeric compounds that were studied by UV-vis, fluorescence, and NMR spectroscopy, as well as X-ray crystallography. The unique symmetry of each diastereomer was confirmed by NMR spectroscopy. NMR data indicated that the syn isomer has restricted rotation about the bond connecting the thiophene and quinoxaline rings, which was also observed in the solid state. The spectroscopic properties of the C-shaped diastereomers were compared to a model compound containing only a single thiophene-substituted quinoxaline ring. Ground state intramolecular π-π interactions in solution were detected by NMR and UV-vis spectroscopy. Red-shifted emission bands, band broadening, and large Stokes shifts were observed, which collectively suggest excited state π-π interactions that produce excimer-like emissions, as well as a remarkable positive emission solvatochromism, indicating charge-transfer character in the excited state.

Particle sizes in Saturn's rings from UVIS stellar occultations 1. Variations with ring region

NASA Astrophysics Data System (ADS)

Colwell, J. E.; Esposito, L. W.; Cooney, J. H.

2018-01-01

The Cassini spacecraft's Ultraviolet Imaging Spectrograph (UVIS) includes a high speed photometer (HSP) that has observed stellar occultations by Saturn's rings with a radial resolution of ∼10 m. In the absence of intervening ring material, the time series of measurements by the HSP is described by Poisson statistics in which the variance equals the mean. The finite sizes of the ring particles occulting the star lead to a variance that is larger than the mean due to correlations in the blocking of photons due to finite particle size and due to random variations in the number of individual particles in each measurement area. This effect was first exploited by Showalter and Nicholson (1990) with the stellar occultation observed by Voyager 2. At a given optical depth, a larger excess variance corresponds to larger particles or clumps that results in greater variation of the signal from measurement to measurement. Here we present analysis of the excess variance in occultations observed by Cassini UVIS. We observe differences in the best-fitting particle size in different ring regions. The C ring plateaus show a distinctly smaller effective particle size, R, than the background C ring, while the background C ring itself shows a positive correlation between R and optical depth. The innermost 700 km of the B ring has a distribution of excess variance with optical depth that is consistent with the C ring ramp and C ring but not with the remainder of the B1 region. The Cassini Division, while similar to the C ring in spectral and structural properties, has different trends in effective particle size with optical depth. There are discrete jumps in R on either side of the Cassini Division ramp, while the C ring ramp shows a smooth transition in R from the C ring to the B ring. The A ring is dominated by self-gravity wakes whose shadow size depends on the occultation geometry. The spectral ;halo; regions around the strongest density waves in the A ring correspond to

20 CFR Appendix C to Part 718 - Blood-Gas Tables

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Blood-Gas Tables C Appendix C to Part 718... PNEUMOCONIOSIS Pt. 718, App. C Appendix C to Part 718—Blood-Gas Tables The following tables set forth the values... tables are met: (1) For arterial blood-gas studies performed at test sites up to 2,999 feet above sea...

Saturn's Rings

NASA Astrophysics Data System (ADS)

Cuzzi, J. N.

2014-12-01

The rings are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major ring science progress over the mission to date, and describe new observations planned for Cassini's final three years. Ring Composition and particle sizes: The rings are nearly all water ice with no other ices - so why are they reddish? The C Ring and Cassini Division are "dirtier" than the more massive B and A Rings, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. Ring structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main ring divisions, the C Ring plateau structures, and the B Ring irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A ring. Rubble pile ringmoons just outside the rings may escaped from the rings, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the rings: Comet fragments set the rings to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the Rings: The ring mass and bombardment play key roles. The ring mass is well known everywhere but in the B Ring (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient rings, of which the current ring is just a shadow. During its last three years, the Cassini tour profile will allow entirely new

Design Considerations for High Energy Electron -- Positron Storage Rings

DOE R&D Accomplishments Database

Richter, B.

1966-11-01

High energy electron-positron storage rings give a way of making a new attack on the most important problems of elementary particle physics. All of us who have worked in the storage ring field designing, building, or using storage rings know this. The importance of that part of storage ring work concerning tests of quantum electrodynamics and mu meson physics is also generally appreciated by the larger physics community. However, I do not think that most of the physicists working tin the elementary particle physics field realize the importance of the contribution that storage ring experiments can make to our understanding of the strongly interacting particles. I would therefore like to spend the next few minutes discussing the sort of things that one can do with storage rings in the strongly interacting particle field.

Ring opening of epoxides with C-nucleophiles.

PubMed

Faiz, Sadia; Zahoor, Ameer Fawad

2016-11-01

Ring opening of epoxides has been an area of interest for organic chemists, owing to their reactivity toward nucleophiles. Such reactions yield important products depending on the type of nucleophiles used. This review article covers the synthetic approaches (1991-2015) used for the ring opening of epoxides via carbon nucleophiles.

Saturn's Rings, the Yarkovsky Effects, and the Ring of Fire

NASA Technical Reports Server (NTRS)

Rubincam, David

2004-01-01

Saturn's icy ring particles, with their low thermal conductivity, are almost ideal for the operation of the Yarkovsky effects. The dimensions of Saturn's A and B rings may be determined by a near balancing of the seasonal Yarkovsky effect with the Yarkovsky- Schach effect. The two effects, which are photon thrust due to temperature gradients, may confine the A and B rings to within their observed dimensions. The C ring may be sparsely populated with icy particles because Yarkovsky drag has pulled them into Saturn, leaving the more slowly orbitally decaying rocky particles. Icy ring particles ejected from the B ring and passing through the C ring, as well as some of the slower rocky particles, should fall on Saturn's equator, where they may create a luminous "Ring of Fire" around Saturn's equator. This predicted Ring of Fire may be visible to Cassini's camera. Curiously, the speed of outwards Yarkovsky orbital evolution appears to peak near the Cassini Division. The connection between the two is not clear. D. Nesvorny has speculated that the resonance at the outer edge of the B ring may impede particles from evolving via Yarkovsky across the Division. If supply from the B ring is largely cut off, then Yarkovsky may push icy particles outward, away from the inner edge of the A ring, leaving only the rocky ones in the Division. The above scenarios depend delicately on the properties of the icy particles.

HST-STIS spectra and the redness of Saturn's rings

NASA Astrophysics Data System (ADS)

Cuzzi, Jeffrey N.; French, Richard G.; Hendrix, Amanda R.; Olson, Daniel M.; Roush, Ted; Vahidinia, Sanaz

2018-07-01

We have observed the main rings of Saturn with the Space Telescope Imaging Spectrometer (STIS) on the Hubble Space Telescope (HST), covering the spectral region from 180-570 nm (including for the first time the critical near-UV range 190-340 nm) with very good signal to noise ratio and a radial resolution of approximately 160-330 km. After correcting for an unexpected grating scatter problem associated with the bright, red, extended planet-ring target, we obtained complete I/F spectra for each major ring region. We have interpreted the spectra in terms of the ring particle material composition using a combination of traditional "Hapke" theory and a new correction for shadowing on the rough, re-entrant ring particle surfaces, along with a correction for the nonclassical scattering of the ring layer itself. We tested a variety of UV absorbers: iron (including nano-iron) grains, hematite, "planetary silicates", organic carbon-ring tholins of varying aromaticity, and amorphous carbon. The A and B rings can contain no more NH3 than about 10-4 by volume. We conclude that the best spectral fit for the well-known, unusually red color of the A and B rings is provided by a sub-percent mass fraction of organic tholins. It appears that the most likely regolith configuration for the A and B Rings is a heterogeneous "intimate mixture", dominated by relatively pure water ice, with some 2-40% of the grains containing roughly 5-10% tholin by volume (the amount depending on whether silicates are present), but it is hard to allow much amorphous carbon to be present in the B Ring material at least. These predictions of compositional heterogeneity can be tested by Cassini direct compositional measurements. There is some suggestion that the tholin properties differ slightly between the A and B rings. We show that tholins of this type, in the abundance we predict, would be difficult to detect at near-IR wavelengths. The C Ring particles have lower albedos, and the best fit models require

Hot piston ring/cylinder liner materials: Selection and evaluation

NASA Technical Reports Server (NTRS)

Sliney, Harold E.

1988-01-01

In current designs of the automotive (kinematic) Stirling engine, the piston rings are made of a reinforced polymer and are located below the pistons because they cannot withstand the high temperatures in the upper cylinder area. Theoretically, efficiency could be improved if hot piston rings were located near the top of the pistons. Described is a program to select piston ring and cylinder coating materials to test this theory. Candidate materials were screened, then subjected to a pin or disk friction and wear test machine. Tests were performed in hydrogen at specimen temperatures up to 760 C to simulate environmental conditions in the region of the hot piston ring reversal. Based on the results of these tests, a cobalt based alloy, Stellite 6B, was chosen for the piston rings and PS200, which consists of a metal-bonded chromium carbide matrix with dispersed solid lubricants, was chosen as the cylinder coating. Tests of a modified engine and a baseline engine showed that the hot ring reduced specific fuel consumption by up to 7 percent for some operating conditions and averaged about 3 percent for all conditions evaluated. Related applications of high-temperature coatings for shaft seals and as back-up lubricants are also described.

Rings Through Atmosphere

NASA Image and Video Library

2010-05-26

NASA Cassini spacecraft looks toward the limb of Saturn and, on the right of this image, views part of the rings through the planet atmosphere. Saturn atmosphere can distort the view of the rings from some angles.

2-Octyl thiophene based three ring mesogens: solid state (13)C NMR and XRD investigations.

PubMed

Veeraprakash, B; Lobo, Nitin P; Narasimhaswamy, T; Mandal, A B

2015-08-14

2-Octyl thiophene based three-ring mesogens namely 4-n-alkoxyphenyl 4-(5-n-octyl-2-thienyl)benzoates are synthesized by employing palladium acetate based direct arylation. The alkoxy terminal is varied with even carbons from C2 to C14 and enantiotropic polymesomorphism is noticed for all the homologs. Accordingly, phase sequence consisting of nematic, smectic A, smectic C and smectic B is seen for mesogens with terminal chains C6, C8, C10 and C12 on cooling the isotropic phase. For mesogens with C2, C4, C8 and C10 terminal alkoxy chains, the mesophase assignment from hot-stage optical microscopy and differential scanning calorimetry is further confirmed by variable temperature powder X-ray diffraction measurements. The appearance of smectic B phase is established by noticing sharp and intense peaks in both small-angle and wide-angle regions. For a representative mesogen, i.e. T10, high-resolution solid-state (13)C NMR investigations are carried out in all the phases, viz. nematic, smectic A, smectic C and smectic B phases. The orientational order parameters calculated from (13)C-(1)H dipolar couplings from 2D SAMPI-4 experiments are found to be 0.44, 0.67, 0.73 and 0.79 in nematic, smectic A, smectic C and smectic B mesophases for the center phenyl ring respectively. Remarkably, the thiophene order parameter in all mesophases is found to be higher than that of phenyl rings and is explained by considering the molecular shape, which has a terminal bend. Further, the mesogens are found to be photoemissive in chloroform solution with an emission band at ∼410 nm.

The Particle Size Distribution in Saturn’s C Ring from UVIS and VIMS Stellar Occultations and RSS Radio Occultations

NASA Astrophysics Data System (ADS)

Jerousek, Richard Gregory; Colwell, Josh; Hedman, Matthew M.; French, Richard G.; Marouf, Essam A.; Esposito, Larry; Nicholson, Philip D.

2017-10-01

The Cassini Ultraviolet Imaging Spectrograph (UVIS) and Visual and Infrared Mapping Spectrometer (VIMS) have measured ring optical depths over a wide range of viewing geometries at effective wavelengths of 0.15 μm and 2.9 μm respectively. Using Voyager S and X band radio occultations and the direct inversion of the forward scattered S band signal, Marouf et al. (1982), (1983), and Zebker et al. (1985) determined the power-law size distribution parameters assuming a minimum particle radius of 1 mm. Many further studies have also constrained aspects of the particle size distribution throughout the main rings. Marouf et al. (2008a) determined the smallest ring particles to have radii of 4-5 mm using Cassini RSS data. Harbison et al. (2013) used VIMS solar occultations and also found minimum particle sizes of 4-5 mm in the C ring with q ~ 3.1, where n(a)da=Ca^(-q)da is the assumed differential power-law size distribution for particles of radius a. Recent studies of excess variance in stellar signal by Colwell et al. (2017, submitted) constrain the cross-section-weighted effective particle radius to 1 m to several meters. Using the wide range of viewing geometries available to VIMS and UVIS stellar occultations we find that normal optical depth does not strongly depend on viewing geometry at 10km resolution (which would be the case if self-gravity wakes were present). Throughout the C ring, we fit power-law derived optical depths to those measured by UVIS, VIMS, and by the Cassini Radio Science Subsystem (RSS) at 0.94 and 3.6 cm wavelengths to constrain the four parameters of the size distribution at 10km radial resolution. We find significant amounts of particle size sorting throughout the region with a positive correlation between maximum particles size (amax) and normal optical depth with a mean value of amax ~ 3 m in the background C ring. This correlation is negative in the C ring plateaus. We find an inverse correlation in minimum particle radius with normal

Properties of tree rings in LSST sensors

DOE PAGES

Park, H. Y.; Nomerotski, A.; Tsybychev, D.

2017-05-30

Images of uniformly illuminated sensors for the Large Synoptic Survey Telescope have circular periodic patterns with an appearance similar to tree rings. Furthermore, these patterns are caused by circularly symmetric variations of the dopant concentration in the monocrystal silicon boule induced by the manufacturing process. Non-uniform charge density results in the parasitic electric field inside the silicon sensor, which may distort shapes of astronomical sources. Here, we analyzed data from fifteen LSST sensors produced by ITL to determine the main parameters of the tree rings: amplitude and period, and also variability across the sensors tested at Brookhaven National Laboratory. Treemore » ring pattern has a weak dependence on the wavelength. But the ring amplitude gets smaller as wavelength gets longer, since longer wavelengths penetrate deeper into the silicon. Tree ring amplitude gets larger as it gets closer to the outer part of the wafer, from 0.1 to 1.0%, indicating that the resistivity variation is larger for larger radii.« less

Properties of tree rings in LSST sensors

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

Park, H. Y.; Nomerotski, A.; Tsybychev, D.

Images of uniformly illuminated sensors for the Large Synoptic Survey Telescope have circular periodic patterns with an appearance similar to tree rings. Furthermore, these patterns are caused by circularly symmetric variations of the dopant concentration in the monocrystal silicon boule induced by the manufacturing process. Non-uniform charge density results in the parasitic electric field inside the silicon sensor, which may distort shapes of astronomical sources. Here, we analyzed data from fifteen LSST sensors produced by ITL to determine the main parameters of the tree rings: amplitude and period, and also variability across the sensors tested at Brookhaven National Laboratory. Treemore » ring pattern has a weak dependence on the wavelength. But the ring amplitude gets smaller as wavelength gets longer, since longer wavelengths penetrate deeper into the silicon. Tree ring amplitude gets larger as it gets closer to the outer part of the wafer, from 0.1 to 1.0%, indicating that the resistivity variation is larger for larger radii.« less

Beckmann rearrangement within the ring C of oleanolic acid lactone: Synthesis, structural study and reaction mechanism analysis

NASA Astrophysics Data System (ADS)

Froelich, Anna; Bednarczyk-Cwynar, Barbara; Zaprutko, Lucjusz; Gzella, Andrzej

2017-05-01

Synthesis, spectral and X-ray analysis of three compounds, i.e. 3β-acetoxy-12-hydroxyimino-18β-oleanan-28,13β-olide (substrate) and 3β-acetoxy-12-nitrile-12,13-seco-15(14 → 13)-abeoolean-14(27)-en-28,13β-olide and 3β-acetoxy-12-oxo-12a-aza-C-homoolean-13(18)-en-28-oic acid (Beckmann rearrangement reaction products) are described. Structural analysis revealed that the oxime group in the ring C in substrate molecule had an E-configuration. The nitrile product with retained lactone group was a result of major transformations within rings C and D of oleanane skeleton. In lactam product free carboxyl group and a double bond in ring D instead of lactone system were formed in Beckmann rearrangement reaction.

High-speed high-stress ring shear tests on granular sods and clayey soils

Treesearch

Hiroshi Fukuoka; Kyoji Sassa

1991-01-01

The purposes of this study is to obtain exact knowledge of the influences on friction angle during shear by shearing speeds. Ring shear tests on sandy and clayey materials have been carried out with a newly developed High-speed High-Stress Ring Shear Apparatus to examine if there are some changes in the frictional behaviors of these materials at high shearing speeds of...

Jupiter Ring Halo

NASA Image and Video Library

1998-03-26

A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age. Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. A faint mist of particles can be seen above and below the main rings; this vertically extended, toroidal "halo" is unusual in planetary rings, and is probably caused by electromagnetic forces which can push small grains out of the ring plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest being

Buckling tests of two 4.6-meter-diameter, magnesium ring-stiffened conical shells loaded under external pressure

NASA Technical Reports Server (NTRS)

Anderson, J. K.; DAVIS R. C.

1973-01-01

Two ring-stiffened magnesium conical shells with a 120 deg apex angle and a 4.6-meter diameter were loaded to failure by a uniform external pressure. The cones differed from one another only in the number of internal stiffening rings. Test specimen details, test procedure, and test results are discussed. Both buckling and prebuckling data are compared with appropriate theoretical predictions. Measured strains in skin and rings agreed well with theoretical predictions. Extensive imperfection measurements were made and reported on both cones in the as fabricated condition.

Surface roughness of Saturn's rings and ring particles inferred from thermal phase curves

NASA Astrophysics Data System (ADS)

Morishima, Ryuji; Turner, Neal J.; Spilker, Linda

2017-10-01

We analyze thermal phase curves of all the main rings of Saturn (the A, B, C rings, and the Cassini division) measured by both the far-IR and mid-IR detectors of the Cassini Composite InfraRed Spectrometer (CIRS). All the rings show temperature increases toward zero phase angle, known as an opposition effect or thermal beaming. For the C ring and Cassini division, which have low optical depths, intra-particle shadowing is considered the dominant mechanism causing the effect. On the other hand, the phase curves of the optically thick B and A rings steepen significantly with decreasing absolute solar elevation angle from 21° to 14°, suggesting inter-particle shadowing plays an important role in these rings. We employ an analytic roughness model to estimate the degrees of surface roughness of the rings or ring particles. For optically thin rings, an isolated particle covered by spherical segment craters is employed while for the thick rings we approximate a packed particle layer as a slab covered by craters. The particles in the thin rings are found to have generally rough surfaces, except in the middle C ring. Across the C ring, the optical depth correlates with the degree of surface roughness. This may indicate that surface roughness comes mainly from particle clumping, while individual particles have rather smooth surfaces. For the optically thick rings, the surface roughness of the particle layer is found to be moderate. The modeled phase curves of optically thick rings are shallow if the phase angle change is primarily due to change of observer azimuthal angle. On the other hand, the phase curves are steep if the phase angle change is due to change of observer elevation angle, as inter-particle shadows become visible at higher observer elevation. In addition, the area of shadowed facets increases with decreasing solar elevation angle. These combined effects explain the large seasonal change of the phase curve steepness observed for the thick rings. The degrees

Surface roughness of Saturn's rings and ring particles inferred from thermal phase curves

NASA Astrophysics Data System (ADS)

Morishima, Ryuji; Turner, Neal; Spilker, Linda

2017-10-01

We analyze thermal phase curves of all the main rings of Saturn (the A, B, C rings, and the Cassini division) measured by both the far-IR and mid-IR detectors of the Cassini Composite InfraRed Spectrometer (CIRS). All the rings show temperature increases toward zero phase angle, known as an opposition effect or thermal beaming. For the C ring and Cassini division, which have low optical depths, intra-particle shadowing is considered the dominant mechanism causing the effect. On the other hand, the phase curves of the optically thick B and A rings steepen significantly with decreasing absolute solar elevation angle from 21° to 14°, suggesting inter-particle shadowing plays an important role in these rings. We employ an analytic roughness model to estimate the degrees of surface roughness of the rings or ring particles. For optically thin rings, an isolated particle covered by spherical segment craters is employed while for the thick rings we approximate a packed particle layer as a slab covered by craters. The particles in the thin rings are found to have generally rough surfaces, except in the middle C ring. Across the C ring, the optical depth correlates with the degree of surface roughness. This may indicate that surface roughness comes mainly from particle clumping, while individual particles have rather smooth surfaces. For the optically thick rings, the surface roughness of the particle layer is found to be moderate. The modeled phase curves of optically thick rings are shallow if the phase angle change is primarily due to change of observer azimuthal angle. On the other hand, the phase curves are steep if the phase angle change is due to change of observer elevation angle, as inter-particle shadows become visible at higher observer elevation. In addition, the area of shadowed facets increases with decreasing solar elevation angle. These combined effects explain the large seasonal change of the phase curve steepness observed for the thick rings. The degrees

Synthesis and evaluation of novel opioid ligands with a C-homomorphinan skeleton.

PubMed

Ishikawa, Kyoko; Mochizuki, Yusuke; Hirayama, Shigeto; Nemoto, Toru; Nagai, Kenichiro; Itoh, Kennosuke; Fujii, Hideaki

2016-05-15

As the reports about C-homomorphinans with the seven-membered C-ring are much fewer than those of morphinan derivatives with a six-membered C-ring, we attempted to synthesize C-homomorphinan derivatives and to evaluate their opioid activities. C-Homomorphinan 5 showed sufficient binding affinities to the opioid receptors. C-Homomorphinan derivatives possessing the δ address moiety such as indole (NTI-type), quinoline, or benzylidene (BNTX-type) functionalities showed the strongest binding affinities for the δ receptor among the three types of opioid receptors, which indicated that the C-homomorphinan skeleton sufficiently functions as a message-part in the ligand. Although NTI-type compound 8 and quinoline compound 9 with C-homomorphinan scaffold exhibited lower affinities and selectivities for the δ receptor than the corresponding morphinan derivatives did, both the binding affinity and selectivity for the δ receptor of BNTX-type compound 12 with a seven-membered C-ring were improved compared with the corresponding compounds with a six-membered C-ring including BNTX itself. BNTX-Type compound 12 was the most selective δ receptor antagonist among the tested compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Planetary astronomy: Rings, satellites, and asteroids

NASA Technical Reports Server (NTRS)

Greenberg, Richard

1988-01-01

Studies of planetary rings focus on the dynamical processes that govern astronomically observable ring properties and structure. These investigations thus help reveal properties of the rings as well as probe the gravity fields of the planets. Satellite studies involve interpretation of orbital motion to extract information regarding the gravity fields of the outer planets and the physical properties of the satellites themselves. Asteroid lightcurve work is designed to investigate the large-scale shapes of the asteroids, as well as to reveal anomalous features such as major topography, possible satellites, or albedo variations. Work on the nature of viscous transport in planetary rings, emphasizing the role of individual particles' physical properties, has yielded a method for estimating both angular momentum and mass transport given an optical-thickness gradient. This result offers the prospect of ringlet instability, which may explain the square-profile ringlets in Saturn's C Ring. Thermal and reflected lightcurves of 532 Herculina have been interpreted to show that albedo variations cannot be the primary cause of variations. A lightcurve simulation has been developed to model complex asteroidal figures. Bamberga was observed during the December occultation as part of the joint LPL-Lowell program.

Composition, formation, and regulation of the cytosolic c-ring, a dynamic component of the type III secretion injectisome.

PubMed

Diepold, Andreas; Kudryashev, Mikhail; Delalez, Nicolas J; Berry, Richard M; Armitage, Judith P

2015-01-01

Many gram-negative pathogens employ a type III secretion injectisome to translocate effector proteins into eukaryotic host cells. While the structure of the distal "needle complex" is well documented, the composition and role of the functionally important cytosolic complex remain less well understood. Using functional fluorescent fusions, we found that the C-ring, an essential and conserved cytosolic component of the system, is composed of ~22 copies of SctQ (YscQ in Yersinia enterocolitica), which require the presence of YscQC, the product of an internal translation initiation site in yscQ, for their cooperative assembly. Photoactivated localization microscopy (PALM) reveals that in vivo, YscQ is present in both a free-moving cytosolic and a stable injectisome-bound state. Notably, fluorescence recovery after photobleaching (FRAP) shows that YscQ exchanges between the injectisome and the cytosol, with a t½ of 68 ± 8 seconds when injectisomes are secreting. In contrast, the secretin SctC (YscC) and the major export apparatus component SctV (YscV) display minimal exchange. Under non-secreting conditions, the exchange rate of YscQ is reduced to t½ = 134 ± 16 seconds, revealing a correlation between C-ring exchange and injectisome activity, which indicates a possible role for C-ring stability in regulation of type III secretion. The stabilization of the C-ring depends on the presence of the functional ATPase SctN (YscN). These data provide new insights into the formation and composition of the injectisome and present a novel aspect of type III secretion, the exchange of C-ring subunits, which is regulated with respect to secretion.

Design of 8-ft-Diameter Barrel Test Article Attachment Rings for Shell Buckling Knockdown Factor Project

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.; Hilburger, Mark W.

2010-01-01

The Shell Buckling Knockdown Factor (SBKF) project includes the testing of sub-scale cylinders to validate new shell buckling knockdown factors for use in the design of the Ares-I and Ares-V launch vehicles. Test article cylinders represent various barrel segments of the Ares-I and Ares-V vehicles, and also include checkout test articles. Testing will be conducted at Marshall Space Flight Center (MSFC) for test articles having an eight-foot diameter outer mold line (OML) and having lengths that range from three to ten feet long. Both ends of the test articles will be connected to the test apparatus using attachment rings. Three multiple-piece and one single-piece design for the attachment rings were developed and analyzed. The single-piece design was chosen and will be fabricated from either steel or aluminum (Al) depending on the required safety factors (SF) for test hardware. This report summarizes the design and analysis of these attachment ring concepts.

Saturn's Rings, the Yarkovsky Effects, and the Ring of Fire

NASA Technical Reports Server (NTRS)

Rubincam, David Parry

2004-01-01

The dimensions of Saturn's A and B rings may be determined by the seasonal Yarkovsky effect and the Yarkovsky-Schach effect; the two effects confine the rings between approximately 1.68 and approximately 2.23 Saturn radii, in reasonable agreement with the observed values of 1.525 and 2.267. The C ring may be sparsely populated because its particles are transients on their way to Saturn; the infall may create a luminous Ring of Fire around Saturn's equator. The ring system may be young: in the past heat flow from Saturn's interior much above its present value would not permit rings to exist.

Dynamics of rings around elongated bodies

NASA Astrophysics Data System (ADS)

Sicardy, Bruno; Leiva, Rodrigo; Ortiz, Jose Luis; Santos Sanz, Pablo; Renner, Stefan; El Moutamid, Maryame; Berard, Diane; Desmars, Josselin; Meza, Erick; Rossi, Gustavo; Braga-Ribas, Felipe; Camargo, Julio; Vieira-Martins, Roberto; Morales, Nicolas; Duffard, Rene; Colas, Francois; Maquet, Lucie; Bouley, Sylvain; Bath, Karl-Ludwig; Beisker, Wolfgang; Dauverge, Jean-Luc; Kretlow, Mike; Chariklo Occultations Team; Haumea Occultation Team

2017-10-01

Dense and narrow rings are encountered around small bodies like the Centaur object Chariklo, and possibly Chiron. The rings and central bodies can be studied in great details thanks to stellar occultations, which accuracies at the km-level. Here we present new results from three high-quality occultations by Chariklo observed in 2017. They provide new insights on the ring geometry and Chariklo's shape. Data are currently being analyzed, but preliminary results are consistent with a triaxial model for Chariklo, with semi-axes a>b>c, where (a-b) may reach values as large as 10-15 km, depending on the model.Such large values induce a strong coupling between the body and an initial collisional debris disk from which the rings emerged. This coupling stems from Lindblad resonances between the ring particle mean motion and Chariklo's spin rate. We find that the resonances clear the corotation zone (estimated to lie at about 215 km from Chariklo's center) in very short time scales (centuries) and pushes the material well beyond the 3/2 resonance - that lies at an estimated radius of 280 km, thus consistent with the radius of Chariklo's main ring C1R, 390 km.Other cases will be examined in view of multi-chord stellar occultations by Trans-Neptunian Objects successfully observed in 2017, as they provide constraints for the presence of material around these bodies. Results and dynamical implications will be presented.Part of this work has received funding from the European Research Council under the European Community's H2020 2014-2020 ERC grant Agreement n°669416 "Lucky Star"

Dusty D Ring

NASA Image and Video Library

2014-02-24

Saturn D ring is easy to overlook since it trapped between the brighter C ring and the planet itself. In this view from NASA Cassini spacecraft, all that can be seen of the D ring is the faint and narrow arc as it stretches from top right of the ima

The Jumping Ring Experiment

ERIC Educational Resources Information Center

Baylie, M.; Ford, P. J.; Mathlin, G. P.; Palmer, C.

2009-01-01

The jumping ring experiment has become central to liquid nitrogen shows given as part of the outreach and open day activities carried out within the University of Bath. The basic principles of the experiment are described as well as the effect of changing the geometry of the rings and their metallurgical state. In general, aluminium rings are…

Solar modulation of cosmic ray intensity and solar flare events inferred from (14)C contents in dated tree rings

NASA Technical Reports Server (NTRS)

Fan, C. Y.; Chen, T. M.; Yun, S. X.; Dai, K. M.

1985-01-01

The delta 14C values in 42 rings of a white spruce grown in Mackenzie Delta was measured as a continuing effort of tracing the history of solar modulation of cosmic ray intensity. The delta 14C values in six rings were measured, in search of a 14C increase due to two large solar flares that occurred in 1942. The results are presented.

Voyager electronic parts radiation program. Volume 2: Test requirements and procedures

NASA Technical Reports Server (NTRS)

Stanley, A. G.; Martin, K. E.; Price, W. E.

1978-01-01

Documents are presented outlining the conditions and requirements of the test program. The Appendixes are as follows: appendix A -- Electron Simulation Radiation Test Specification for Voyager Electronic Parts and Devices, appendix B -- Electronic Piece-Part Testing Program for Voyager, appendix C -- Test Procedure for Radiation Screening of Voyager Piece Parts, appendix D -- Boeing In Situ Test Fixture, and appendix E -- Irradiate - Anneal (IRAN) Screening Documents.

Uranus and the shape of elliptical rings

NASA Technical Reports Server (NTRS)

Lucke, R. L.

1978-01-01

It is reported that when the star SAO158687 passed behind the Uranus system, its light was occulted twice by the epsilon (fifth) ring of the planet. The first part of the ring to occult was about 100 km wide and the second part was about 40 km wide. The variable width of the ring is accounted for by differences in the orbital eccentricities of the individual particles composing the ring.

Time-series analysis of delta13C from tree rings. I. Time trends and autocorrelation.

PubMed

Monserud, R A; Marshall, J D

2001-09-01

Univariate time-series analyses were conducted on stable carbon isotope ratios obtained from tree-ring cellulose. We looked for the presence and structure of autocorrelation. Significant autocorrelation violates the statistical independence assumption and biases hypothesis tests. Its presence would indicate the existence of lagged physiological effects that persist for longer than the current year. We analyzed data from 28 trees (60-85 years old; mean = 73 years) of western white pine (Pinus monticola Dougl.), ponderosa pine (Pinus ponderosa Laws.), and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca) growing in northern Idaho. Material was obtained by the stem analysis method from rings laid down in the upper portion of the crown throughout each tree's life. The sampling protocol minimized variation caused by changing light regimes within each tree. Autoregressive moving average (ARMA) models were used to describe the autocorrelation structure over time. Three time series were analyzed for each tree: the stable carbon isotope ratio (delta(13)C); discrimination (delta); and the difference between ambient and internal CO(2) concentrations (c(a) - c(i)). The effect of converting from ring cellulose to whole-leaf tissue did not affect the analysis because it was almost completely removed by the detrending that precedes time-series analysis. A simple linear or quadratic model adequately described the time trend. The residuals from the trend had a constant mean and variance, thus ensuring stationarity, a requirement for autocorrelation analysis. The trend over time for c(a) - c(i) was particularly strong (R(2) = 0.29-0.84). Autoregressive moving average analyses of the residuals from these trends indicated that two-thirds of the individual tree series contained significant autocorrelation, whereas the remaining third were random (white noise) over time. We were unable to distinguish between individuals with and without significant autocorrelation

Stable carbon isotopic composition of tree rings from a pine tree from Augustów Wilderness, Poland, as a temperature and local environment conditions indicator.

PubMed

Pawelczyk, Slawomira; Pazdur, Anna; Halas, Stanislaw

2004-06-01

Tree rings can be used as archives of climatic and environmental data with annual resolution. Tree rings widths, maximum late wood density and other parameters as stable composition in tree rings can be used for the reconstruction of past climatic and environmental changes. Stable carbon isotope ratios in tree rings may provide valuable information on past climatic conditions. 13C/12C ratios of plant organic matter can reflect corresponding 13C/12C ratio of atmospheric CO2 during formation of the rings. Investigations of isotopic carbon composition in tree rings from in the ecologically clean the Augustów Wilderness region in the north-eastern part of Poland (22 degrees 58'E, 53 degrees 51'N) (nowadays a sanctuary) were undertaken. Series of delta13C in alpha-cellulose and in wholewood were acquired. Those measurements constituted a part of more complex investigations of carbon isotope composition in tree rings including the measurements of radiocarbon concentration and tree ring widths. This article presents preliminary results. It is argued that contrary to the tree ring widths and delta13C in wholewood that do not reveal significant correlation with temperature, the variation of delta13C in the latewood alpha-cellulose is correlated with combined July and August temperatures. Copyright 2004 Taylor and Francis Ltd.

24 CFR Appendix C to 24 Cfr Part 3400 - Appendix C to 24 CFR Part 3400

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Appendix C to 24 CFR Part 3400 C Appendix C to 24 CFR Part 3400 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT SAFE MORTGAGE LICENSING ACT Pt. 3400, App. C Appendix C to 24 CFR Part 3400...

A Large Seasonal Variation of Energetic C+ and CO+ Abundances in Saturn's Magnetosphere Probably Resulting from Changing Ring Illumination

NASA Astrophysics Data System (ADS)

Hamilton, D. C.; Christon, S. P.

2017-12-01

In mid-2014 the Cassini/CHEMS instrument observed a rather dramatic increase in the relative abundances of both C+ and CO+ (factors of 2 to 4). The enhancements then decreased during 2015 and 2016, with CO+ decreasing much more quickly. C+ and CO+ (these mass 28 molecular ions could also include N2+) are trace components of the energetic (96-220 keV) ion population in Saturn's magnetosphere, which is dominated by water group ions W+ (O+, OH+, and H2O+ and H30+), H+, and H2+. We suggest that the C+ and CO+ enhancements are associated with CO2, possibly from Enceladus, building up on the cold rings near equinox, but then released from the north side of the A, and possibly B, rings as they were warmed above 80K in late 2013 or early 2014 by increasing solar illumination after the 2009 equinox (Morishima et al, 2016). Hodyss et al (2008) found preferential sublimation of CO2 from a CO2:H2O ice mixture when it was warmed above 80K. Meteoroid bombardment could be another source of carbon in the ring ice. After release from the ice, transport, dissociation, ionization, and then acceleration in the magnetosphere would produce the observed energetic C+ and CO+, with the enhancements subsiding as the CO2 and other carbon species gradually become depleted. We will report the relevant abundance ratios from SOI in 2004 through the Sept. 15, 2017 end of mission to test this hypothesis. Hodyss, R. et al, Icarus, 194, 836-842, 2008. Morishima, R. et al, Icarus, 279, 2-19, 2016.

Development and evaluation of accelerated drug release testing methods for a matrix-type intravaginal ring.

PubMed

Externbrink, Anna; Eggenreich, Karin; Eder, Simone; Mohr, Stefan; Nickisch, Klaus; Klein, Sandra

2017-01-01

Accelerated drug release testing is a valuable quality control tool for long-acting non-oral extended release formulations. Currently, several intravaginal ring candidates designed for the long-term delivery of steroids or anti-infective drugs are being in the developing pipeline. The present article addresses the demand for accelerated drug release methods for these formulations. We describe the development and evaluation of accelerated release methods for a steroid releasing matrix-type intravaginal ring. The drug release properties of the formulation were evaluated under real-time and accelerated test conditions. Under real-time test conditions drug release from the intravaginal ring was strongly affected by the steroid solubility in the release medium. Under sufficient sink conditions that were provided in release media containing surfactants drug release was Fickian diffusion driven. Both temperature and hydro-organic dissolution media were successfully employed to accelerate drug release from the formulation. Drug release could be further increased by combining the temperature effect with the application of a hydro-organic release medium. The formulation continued to exhibit a diffusion controlled release kinetic under the investigated accelerated conditions. Moreover, the accelerated methods were able to differentiate between different prototypes of the intravaginal ring that exhibited different release profiles under real-time test conditions. Overall, the results of the present study indicate that both temperature and hydro-organic release media are valid parameters for accelerating drug release from the intravaginal ring. Variation of either a single or both parameters yielded release profiles that correlated well with real-time release. Copyright © 2016 Elsevier B.V. All rights reserved.

Total Synthesis of Bryostatins. Development of Methodology for Atom-Economic and Stereoselective Synthesis of the C-ring Subunit

PubMed Central

Trost, Barry M.; Frontier, Alison J.; Thiel, Oliver R.; Yang, Hanbiao; Dong, Guangbin

2012-01-01

Bryostatins, a family of structurally complicated macrolides, exhibit an exceptional range of biological activities. The limited availability and structural complexity of these molecules makes development of an efficient total synthesis particularly important. This article describes our initial efforts towards the total synthesis of bryostatins, in which chemoselective and atom-economical methods for stereoselective assembly of the C-ring subunit were developed. A Pd-catalyzed tandem alkyne-alkyne coupling/6-endo-dig cyclization sequence was explored and successfully pursued in the synthesis of a dihydropyran ring system. Elaboration of this methodology ultimately led to a concise synthesis of the C-ring subunit of bryostatins. PMID:21793057

Jupiter's ring

NASA Technical Reports Server (NTRS)

1979-01-01

First evidence of a ring around the planet Jupiter is seen in this photograph taken by Voyager 1 on March 4, 1979. The multiple exposure of the extremely thin faint ring appears as a broad light band crossing the center of the picture. The edge of the ring is 1,212,000 km from the spacecraft and 57,000 km from the visible cloud deck of Jupiter. The background stars look like broken hair pins because of spacecraft motion during the 11 minute 12 second exposure. The wavy motion of the star trails is due to the ultra-slow natural oscillation of the spacecraft (with a period of 78 seconds). The black dots are geometric calibration points in the camera. The ring thickness is estimated to be 30 km or less. The photograph was part of a sequence planned to search for such rings in Jupiter's equatorial plane. The ring has been invisible from Earth because of its thinness and its transparency when viewed at any angle except straight on. JPL manages and controls the Voyager Project for NASA's Office of Space Science.

Modeling 13C discrimination in Tree Rings

NASA Astrophysics Data System (ADS)

Berninger, Frank; Sonninen, Eloni; Aalto, Tuula; Lloyd, Jon

2000-03-01

Annual variations from 1877 to 1995 in tree-ring α-cellulose 13C/12C isotopic ratios for four subarctic Pinus sylvestris trees were determined, and, in conjunction with a recent record of atmospheric 13CO2/12CO2 ratios, the historical pattern of photosynthetic isotope discrimination, Δ13C, was evaluated. Year-to-year variability in Δ13C has been as much as 1.5‰ with the period 1900-1920 showing an extended period of unusually high photosynthetic discriminations. The summers during these years were, on average, unusually cold. Since 1920 a long term trend of increasing Δ13C of ˜0.016‰yr-1 is inferred. We compared measured Δ13C with those predicted on the basis of the theoretical relationship between Δ13C and the ratio of substomatal to ambient CO2 concentration, Ci/Ca using mechanistic equations for chloroplast biochemistry coupled with a stomatal conductance model. Two variations of a nonlinear optimal-regulation stomatal conductance model were compared. Although both models were based on the assumption that stomata serve to minimize the average transpiration rate for a given average rate of CO2 assimilation, one version of the model incorporated reductions in stomatal conductance in response to recent increases in atmospheric CO2 concentrations and the other did not. The CO2 sensitive stomatal model failed to describe the long-term increase in 13C discrimination, especially after 1950. The insensitive model gave good agreement, suggesting that an observed increase in subarctic Pinus sylvestris Δ13C since 1920 is attributable to recent increases in atmospheric CO2 concentrations with subsequent increases in the ratio of substomatal to ambient CO2 concentrations. The model was also capable of accounting for high frequency (year-to-year) variations in Δ13C, these differences being attributable to year-to-year fluctuations in the average leaf-to-air vapor pressure difference affecting stomatal conductance and hence Ci/Ca.

Test Method Designed to Evaluate Cylinder Liner-Piston Ring Coatings for Advanced Heat Engines

NASA Technical Reports Server (NTRS)

Radil, Kevin C.

1997-01-01

Research on advanced heat engine concepts, such as the low-heat-rejection engine, have shown the potential for increased thermal efficiency, reduced emissions, lighter weight, simpler design, and longer life in comparison to current diesel engine designs. A major obstacle in the development of a functional advanced heat engine is overcoming the problems caused by the high combustion temperatures at the piston ring/cylinder liner interface, specifically at top ring reversal (TRR). Therefore, advanced cylinder liner and piston ring materials are needed that can survive under these extreme conditions. To address this need, researchers at the NASA Lewis Research Center have designed a tribological test method to help evaluate candidate piston ring and cylinder liner materials for advanced diesel engines.

Perylenetetracarboxylic anhydride as a precursor of fluorescent carbon nanoonion rings.

PubMed

Baldoví, Herme G; Herance, José Raul; Manuel Víctor, Víctor; Alvaro, Mercedes; Garcia, Hermenegildo

2015-08-07

Thermal annealing at 400 °C of perylenetetracarboxylic anhydride in low molecular mass PEG gives rise to the formation of well defined nanoobjects of 2.5 nm height and size distribution from 10 to 65 nm (average 40 nm) after purification of the raw mixture with silicagel chromatography. TEM reveals that the flat nanoobjects are constituted of concentric graphenic rings (0.34 nm interlayer distance). The morphology of the nanoparticles resembles onion rings of nanometric dimensions (nanoonion rings C-NOR). C-NOR particles have an excitation dependent emission with λem from 430 to 570 nm and a maximum emission quantum yield of 0.49. C-NOR particles can be internalized into Hep3B human hepatoma cells as determined by confocal fluorescence microscopy and are remarkably biocompatible affecting slightly cell viability according to the MTT test.

Tests of oil scraper piston ring and piston fitted with oil drain holes

NASA Technical Reports Server (NTRS)

Mcdewell, H S

1922-01-01

Tests were conducted to determine whether or not a properly located and properly designed oil scraper piston ring, installed on a piston provided with oil drain holes of sufficient area, would prevent the excessive oiling of the Liberty engine, particularly with the engine running at idling speed with full oil pressure. Results showed that excessive oiling was in fact prevented. It is strongly recommended that scraper rings and pistons be adopted for aircraft engines.

DC-Powered Jumping Ring

NASA Astrophysics Data System (ADS)

Jeffery, Rondo N.; Amiri, Farhang

2016-02-01

The classroom jumping ring demonstration is nearly always performed using alternating current (AC), in which the ring jumps or flies off the extended iron core when the switch is closed. The ring jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant differences from the AC case. In particular, the ring does not fly off the core but rises a short distance and then falls back. If the ring jumps high enough, the rising and the falling motion of the ring does not follow simple vertical motion of a projectile. This indicates that there are additional forces on the ring in each part of its motion. Four possible stages of the motion of the ring with DC are identified, which result from the ring current changing directions during the jump in response to a changing magnetic flux through the moving ring.

Evaluation of the Performance of O-rings Made with Different Elastomeric Polymers in Simulated Geothermal Environments at 300°C

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

Sugama, Toshifumi; Pyatina, Tatiana; Redline, Erica Marie

2014-12-01

This paper aims to evaluate the survival of O-rings made with six different elastomeric polymers, EPDM, type I- and II-FKM, FEPM, FFKM, and FSR, in five different simulated geothermal environments at 300°C. It further defines the relative strengths and weaknesses of the materials in each environment. The environments tested were: 1) non-aerated steam-cooling cycles, 2) aerated steam-cooling cycles, 3) water-based drilling fluid, 4) CO2-rich geo-brine fluid, and, 5) heat-cool water quenching cycles. Following exposure, the extent of oxidation, oxidationinduced degradation, thermal behaviors, micro-defects, permeation depths of ionic species present in environments throughout the O-ring, silicate-related scale-deposition, and changes in mechanicalmore » properties were assessed.« less

40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart C...

40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart C...

40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart C...

40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart C...

40 CFR Table C-2 to Subpart C of... - Sequence of Test Measurements

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Sequence of Test Measurements C Table C-2 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Comparability Between Candidate Methods and Reference Methods Pt. 53, Subpt. C, Table C-2 Table C-2 to Subpart C...

Nitrile O-ring Cracking: A Case of Vacuum Flange O-ring Failures

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

Dees, Craig

2016-07-01

A review of recent nitrile O-ring failures in ISO-KF vacuum flange connections in glovebox applications is presented. An investigation of a single “isolated” o-ring failure leads to the discovery of cracked nitrile o-rings in a glovebox atmospheric control unit. The initial cause of the o-ring failure is attributed to ozone degradation. However, additional investigation reveals nitrile o-ring cracking on multiple gloveboxes and general purpose piping, roughly 85% of the nitrile o-rings removed for inspection show evidence of visible cracking after being in service for 18 months or less. The results of material testing and ambient air testing is presented, elevatedmore » ozone levels are not found. The contributing factors of o-ring failure, including nitrile air sensitivity, inadequate storage practices, and poor installation techniques, are discussed. A discussion of nitrile o-ring material properties, the benefits and limitations, and alternate materials are discussed. Considerations for o-ring material selection, purchasing, storage, and installation are presented in the context of lessons learned from the nitrile o-ring cracking investigation. This paper can be presented in 20 minutes and does not require special accommodations or special audio visual devices.« less

X-Ray study of hetero ring flexibility in norbornane, norbornene-fused 1,3-oxazin-2-thiones Structure of 5,8-methano- r-4-phenyl-c-4a, c-5,6,7, c-8, c- 8a-hexahydro-4H- 1 ,3-benzoxazin-2 (3H)-thione

NASA Astrophysics Data System (ADS)

Kálmán, A.; Argay, Gy.; Stájer, G.; Bernáth, G.

1991-08-01

The structure of S,8-methano- r-4-phenyl c4a, c5,6,7 c8 c8ahexahydro4 H 1,3 -benzoxazin- 2 (3 H)-thione (C 15H 17N0S, M r=259.37) has been established by X-ray crystallography from diffractometer data: it crystallizes in the monoclinic space group P2 1/n with a=6.150(2) Å, b=9.655(1) Å, c=22.093(4) Å,β=96.75(2)† V=1302.7(8) Å 3,4,D c=1.32gcm -3and p( Cu K) =20.4cm -. The structure has been solved by direct methods, refined to R=0.050 for 2193 observed reflections. The X-ray analysis substantiated the structure: the NMR spectra in- dicated that the 4-phenyl group assumes an exo-equatorial position. The puckering parameters of D. Cremer, J.A. Pople, J. Am. Chem. Soc., 97 (1975), 1354 (ref.1), of the distorted hetero ring (a transitional form between E 4-envelope, ( 5S 4-screw-boat) show that, depending on the positions of the hetero atoms, both the norbornane, norbornene skeletons markedly alter the characteristic transitional ( 5E/ 5H 6) shape of the 1,3-oxazine ring observed in other saturated, partly saturated l,3-benzoxazin-2-ones, analogous thiones.

40 CFR Table C-3 to Subpart C of... - Test Specifications for Pb in TSP and Pb in PM10 Methods

Code of Federal Regulations, 2011 CFR

2011-07-01

... Pb in PM10 Methods C Table C-3 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL..., Subpt. C, Table C-3 Table C-3 to Subpart C of Part 53—Test Specifications for Pb in TSP and Pb in PM10 Methods Table C-3 to Subpart C of Part 53—Test Specifications for Pb in TSP and Pb in PM10 Methods...

40 CFR Table C-3 to Subpart C of... - Test Specifications for Pb in TSP and Pb in PM10 Methods

Code of Federal Regulations, 2010 CFR

2010-07-01

... Pb in PM10 Methods C Table C-3 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL..., Subpt. C, Table C-3 Table C-3 to Subpart C of Part 53—Test Specifications for Pb in TSP and Pb in PM10 Methods Table C-3 to Subpart C of Part 53—Test Specifications for Pb in TSP and Pb in PM10 Methods...

10 CFR Appendix C to Subpart C of... - Sampling Plan for Enforcement Testing of Distribution Transformers

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Sampling Plan for Enforcement Testing of Distribution Transformers C Appendix C to Subpart C of Part 429 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION... Testing of Distribution Transformers (a) When testing distribution transformers, the number of units in...

10 CFR Appendix C to Subpart C of... - Sampling Plan for Enforcement Testing of Distribution Transformers

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Sampling Plan for Enforcement Testing of Distribution Transformers C Appendix C to Subpart C of Part 429 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION... Testing of Distribution Transformers (a) When testing distribution transformers, the number of units in...

10 CFR Appendix C to Subpart C of... - Sampling Plan for Enforcement Testing of Distribution Transformers

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Sampling Plan for Enforcement Testing of Distribution Transformers C Appendix C to Subpart C of Part 429 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION... Testing of Distribution Transformers (a) When testing distribution transformers, the number of units in...

Processing and Prolonged 500 C Testing of 4H-SiC JFET Integrated Circuits with Two Levels of Metal Interconnect

NASA Technical Reports Server (NTRS)

Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Lukco, Dorothy; Chang, Carl W.; Beheim, Glenn M.; Krasowski, Michael J.; Prokop, Norman F.

2015-01-01

Complex integrated circuit (IC) chips rely on more than one level of interconnect metallization for routing of electrical power and signals. This work reports the processing and testing of 4H-SiC junction field effect transistor (JFET) prototype ICs with two levels of metal interconnect capable of prolonged operation at 500 C. Packaged functional circuits including 3-and 11-stage ring oscillators, a 4-bit digital to analog converter, and a 4-bit address decoder and random access memory cell have been demonstrated at 500 C. A 3-stage oscillator functioned for over 3000 hours at 500 C in air ambient.

49 CFR Appendix C to Part 192 - Qualification of Welders for Low Stress Level Pipe

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Qualification of Welders for Low Stress Level Pipe C Appendix C to Part 192 Transportation Other Regulations Relating to Transportation (Continued.... C Appendix C to Part 192—Qualification of Welders for Low Stress Level Pipe I. Basic test. The test...

49 CFR Appendix C to Part 192 - Qualification of Welders for Low Stress Level Pipe

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Qualification of Welders for Low Stress Level Pipe C Appendix C to Part 192 Transportation Other Regulations Relating to Transportation (Continued.... C Appendix C to Part 192—Qualification of Welders for Low Stress Level Pipe I. Basic test. The test...

49 CFR Appendix C to Part 192 - Qualification of Welders for Low Stress Level Pipe

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Qualification of Welders for Low Stress Level Pipe C Appendix C to Part 192 Transportation Other Regulations Relating to Transportation (Continued.... C Appendix C to Part 192—Qualification of Welders for Low Stress Level Pipe I. Basic test. The test...

49 CFR Appendix C to Part 192 - Qualification of Welders for Low Stress Level Pipe

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Qualification of Welders for Low Stress Level Pipe C Appendix C to Part 192 Transportation Other Regulations Relating to Transportation (Continued.... C Appendix C to Part 192—Qualification of Welders for Low Stress Level Pipe I. Basic test. The test...

49 CFR Appendix C to Part 192 - Qualification of Welders for Low Stress Level Pipe

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Qualification of Welders for Low Stress Level Pipe C Appendix C to Part 192 Transportation Other Regulations Relating to Transportation (Continued.... C Appendix C to Part 192—Qualification of Welders for Low Stress Level Pipe I. Basic test. The test...

Jupiter's Ring Halo

NASA Technical Reports Server (NTRS)

1997-01-01

A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow.

A faint mist of particles can be seen above and below the main rings; this vertically extended, toroidal 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces which can push small grains out of the ring plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges...

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges...

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges...

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges...

Jupiter Ring

NASA Image and Video Library

2000-03-23

First evidence of a ring around the planet Jupiter is seen in this photograph taken by Voyager 1 on March 4, 1979. The multiple exposure of the extremely thin faint ring appears as a broad light band crossing the center of the picture. The edge of the ring is 1,212,000 km from the spacecraft and 57,000 km from the visible cloud deck of Jupiter. The background stars look like broken hair pins because of spacecraft motion during the 11 minute 12 second exposure. The wavy motion of the star trails is due to the ultra-slow natural oscillation of the spacecraft (with a period of 78 seconds). The black dots are geometric calibration points in the camera. The ring thickness is estimated to be 30 km or less. The photograph was part of a sequence planned to search for such rings in Jupiter's equatorial plane. The ring has been invisible from Earth because of its thinness and its transparency when viewed at any angle except straight on. JPL manages and controls the Voyager Project for NASA's Office of Space Science. http://photojournal.jpl.nasa.gov/catalog/PIA02251

Jupiter's Main Ring

NASA Technical Reports Server (NTRS)

1997-01-01

A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the ring's ansa. A faint mist of particles can be seen above and below the main rings; this vertically extended 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces pushing the smallest grains out of the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic.

Jupiter's main ring is a thin strand of material encircling the planet. The diffuse innermost boundary begins at approximately 123,000 km. The main ring's outer radius is found to be

Aging Behavior of the EPDM O-Rings in the H1616 Shipping Package

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

Daugherty, W.; Stefek, T.; Skidmore, E.

The H1616 shipping package is used within the DOE complex for shipping tritium reservoirs. The annual recertification frequency can create logistical difficulties with other constraints on the timing of shipments; thus, a longer re-certification period is desirable. The ethylene propylene diene monomer (EPDM) O-rings used in the H1616 shipping package are being aged and tested at the Savannah River National Laboratory (SRNL) to provide a technical basis for extending the annual maintenance of the H1616 shipping package. H1616 EPDM O-rings are being aged at elevated temperature, and tested for degradation in mechanical properties, compression stress relaxation (CSR) behavior, and leakmore » performance. Mechanical properties of aged O-rings show significant degradation can occur, but an inert atmosphere (argon backfill) greatly reduces the rate of degradation. The CSR behavior of O-rings was evaluated in air at 79 to 177 °C. These collective data were used to develop a predictive model for extrapolation of CSR behavior to relevant service temperatures (<67 °C). O-rings were also aged in H1616 Containment Vessels (CV) in an inert atmosphere at 71 to 149 °C. The vessels are helium leak tested periodically to determine if they continue to remain leak-tight. The vessel tests provide a solid demonstration that the H1616 O-rings will remain leak-tight at temperatures up to 113 °C for up to approximately 2.3 years. Significantly longer periods of leak-tight service are expected at the lower temperatures actually experienced in service. The predictive model developed from the CSR data conservatively indicates a service life of ~5 years at 67 °C. Although the relationship between CSR behavior and leak-tight performance has not been established for this design, the CSR predictions for this O-ring are conservative relative to leak-tight performance. Based on the collective data developed to date, SRNL has recommended that the maintenance interval for the H1616 package

Planetary Rings

NASA Astrophysics Data System (ADS)

Tiscareno, Matthew S.

Planetary rings are the only nearby astrophysical disks and the only disks that have been investigated by spacecraft (especially the Cassini spacecraft orbiting Saturn). Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 10- 7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close range and in real time in planetary rings.We review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We then review planetary rings by type. The A, B, and C rings of Saturn, plus the Cassini Division, comprise our solar system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are found both at Uranus (where they comprise the main rings entirely) and at Saturn (where they are embedded in the broad disk) and are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty rings, likely generated by embedded source bodies, are surprisingly found to sport azimuthally confined arcs at Neptune, Saturn, and Jupiter. Finally, every known ring system includes a substantial component of diffuse dusty rings.Planetary rings have shown themselves to be useful as detectors of planetary processes around them, including the planetary magnetic field and interplanetary impactors as well as the gravity of nearby perturbing moons. Experimental rings science has made great progress in recent decades, especially numerical simulations of self-gravity wakes and other processes but also laboratory investigations of coefficient of restitution and spectroscopic ground truth. The age of self-sustained ring systems is a matter of

Rare RNF213 variants in the C-terminal region encompassing the RING-finger domain are associated with moyamoya angiopathy in Caucasians.

PubMed

Guey, Stéphanie; Kraemer, Markus; Hervé, Dominique; Ludwig, Thomas; Kossorotoff, Manoëlle; Bergametti, Françoise; Schwitalla, Jan Claudius; Choi, Simone; Broseus, Lucile; Callebaut, Isabelle; Genin, Emmanuelle; Tournier-Lasserve, Elisabeth

2017-08-01

Moyamoya angiopathy (MMA) is a cerebral angiopathy affecting the terminal part of internal carotid arteries. Its prevalence is 10 times higher in Japan and Korea than in Europe. In East Asian countries, moyamoya is strongly associated to the R4810K variant in the RNF213 gene that encodes for a protein containing a RING-finger and two AAA+ domains. This variant has never been detected in Caucasian MMA patients, but several rare RNF213 variants have been reported in Caucasian cases. Using a collapsing test based on exome data from 68 European MMA probands and 573 ethnically matched controls, we showed a significant association between rare missense RNF213 variants and MMA in European patients (odds ratio (OR)=2.24, 95% confidence interval (CI)=(1.19-4.11), P=0.01). Variants specific to cases had higher pathogenicity predictive scores (median of 24.2 in cases versus 9.4 in controls, P=0.029) and preferentially clustered in a C-terminal hotspot encompassing the RING-finger domain of RNF213 (P<10 -3 ). This association was even stronger when restricting the analysis to childhood-onset and familial cases (OR=4.54, 95% CI=(1.80-11.34), P=1.1 × 10 -3 ). All clinically affected relatives who were genotyped were carriers. However, the need for additional factors to develop MMA is strongly suggested by the fact that only 25% of mutation carrier relatives were clinically affected.

Compositional Evolution of Saturn's Rings Due to Meteoroid Bombardment

NASA Technical Reports Server (NTRS)

Cuzzi, J.; Estrada, P.; Young, Richard E. (Technical Monitor)

1997-01-01

In this paper we address the question of compositional evolution in planetary ring systems subsequent to meteoroid bombardment. The huge surface area to mass ratio of planetary rings ensures that this is an important process, even with current uncertainties on the meteoroid flux. We develop a new model which includes both direct deposition of extrinsic meteoritic "pollutants", and ballistic transport of the increasingly polluted ring material as impact ejecta. Our study includes detailed radiative transfer modeling of ring particle spectral reflectivities based on refractive indices of realistic constituents. Voyager data have shown that the lower optical depth regions in Saturn's rings (the C ring and Cassini Division) have darker and less red particles than the optically thicken A and B rings. These coupled structural-compositional groupings have never been explained; we present and explore the hypothesis that global scale color and compositional differences in the main rings of Saturn arise naturally from extrinsic meteoroid bombardment of a ring system which was initially composed primarily, but not entirely, of water ice. We find that the regional color and albedo differences can be understood if all ring material was initially identical (primarily water ice, based on other data, but colored by tiny amounts of intrinsic reddish, plausibly organic, absorber) and then evolved entirely by addition and mixing of extrinsic, nearly neutrally colored. plausibly carbonaceous material. We further demonstrate that the detailed radial profile of color across the abrupt B ring - C ring boundary can.constrain key unknown parameters in the model. Using new alternates of parameter values, we estimate the duration of the exposure to extrinsic meteoroid flux of this part of the rings, at least, to be on the order of 10(exp 8) years. This conclusion is easily extended by inference to the Cassini Division and its surroundings as well. This geologically young "age" is compatible

Intra-annual variability of anatomical structure and δ13C values within tree rings of spruce and pine in alpine, temperate and boreal Europe

PubMed Central

Vaganov, Eugene A.; Skomarkova, Marina V.; Knohl, Alexander; Brand, Willi A.; Roscher, Christiane

2009-01-01

Tree-ring width, wood density, anatomical structure and 13C/12C ratios expressed as δ13C-values of whole wood of Picea abies were investigated for trees growing in closed canopy forest stands. Samples were collected from the alpine Renon site in North Italy, the lowland Hainich site in Central Germany and the boreal Flakaliden site in North Sweden. In addition, Pinus cembra was studied at the alpine site and Pinus sylvestris at the boreal site. The density profiles of tree rings were measured using the DENDRO-2003 densitometer, δ13C was measured using high-resolution laser-ablation-combustion-gas chromatography-infra-red mass spectrometry and anatomical characteristics of tree rings (tracheid diameter, cell-wall thickness, cell-wall area and cell-lumen area) were measured using an image analyzer. Based on long-term statistics, climatic variables, such as temperature, precipitation, solar radiation and vapor pressure deficit, explained <20% of the variation in tree-ring width and wood density over consecutive years, while 29–58% of the variation in tree-ring width were explained by autocorrelation between tree rings. An intensive study of tree rings between 1999 and 2003 revealed that tree ring width and δ13C-values of whole wood were significantly correlated with length of the growing season, net radiation and vapor pressure deficit. The δ13C-values were not correlated with precipitation or temperature. A highly significant correlation was also found between δ13C of the early wood of one year and the late wood of the previous year, indicating a carry-over effect of the growing conditions of the previous season on current wood production. This latter effect may explain the high autocorrelation of long-term tree-ring statistics. The pattern, however, was complex, showing stepwise decreases as well as stepwise increases in the δ13C between late wood and early wood. The results are interpreted in the context of the biochemistry of wood formation and its linkage

Coaxial Dump Ramjet Combustor Combustion Instabilities. Part I. Parametric Test Data.

DTIC Science & Technology

1981-07-01

AD-AIII 355 COAXIAL DUP RA8.? COMBUSTOR COMBUSTION INSTABILITIES I/~ PART I PARAUER1C. 1111 AIR FORCE WRIONT AERONUTICAL LAOS WRIOIII-PATTERSOll...MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANOAROS - 193- A AFWAL-TR-81 -2047 Part 1 COAXIAL DUMP RAMJET COMBUSTOR COMBUSTION INSTABILITIES PART...COMBUSTOR Interim Report for Period COMBUSTION INSTABILITIES February 1979 - March 1980 Part I - Parametric Test Data S. PERFORMING ORG. REPORT NUMBER 7

Processing and Prolonged 500 C Testing of 4H-SiC JFET Integrated Circuits with Two Levels of Metal Interconnect

NASA Technical Reports Server (NTRS)

Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Lukco, Dorothy; Chang, Carl W.; Beheim, Glenn M.; Krasowski, Michael J.; Prokop, Norman F.

2015-01-01

Complex integrated circuit (IC) chips rely on more than one level of interconnect metallization for routing of electrical power and signals. This work reports the processing and testing of 4H-SiC junction field effect transistor (JFET) prototype IC's with two levels of metal interconnect capable of prolonged operation at 500 C. Packaged functional circuits including 3- and 11-stage ring oscillators, a 4-bit digital to analog converter, and a 4-bit address decoder and random access memory cell have been demonstrated at 500 C. A 3-stage oscillator functioned for over 3000 hours at 500 C in air ambient. Improved reproducibility remains to be accomplished.

Resveratrol and para-coumarate serve as ring precursors for coenzyme Q biosynthesis[S

PubMed Central

Xie, Letian X.; Williams, Kevin J.; He, Cuiwen H.; Weng, Emily; Khong, San; Rose, Tristan E.; Kwon, Ohyun; Bensinger, Steven J.; Marbois, Beth N.; Clarke, Catherine F.

2015-01-01

Coenzyme Q (Q or ubiquinone) is a redox-active polyisoprenylated benzoquinone lipid essential for electron and proton transport in the mitochondrial respiratory chain. The aromatic ring 4-hydroxybenzoic acid (4HB) is commonly depicted as the sole aromatic ring precursor in Q biosynthesis despite the recent finding that para-aminobenzoic acid (pABA) also serves as a ring precursor in Saccharomyces cerevisiae Q biosynthesis. In this study, we employed aromatic 13C6-ring-labeled compounds including 13C6-4HB, 13C6-pABA, 13C6-resveratrol, and 13C6-coumarate to investigate the role of these small molecules as aromatic ring precursors in Q biosynthesis in Escherichia coli, S. cerevisiae, and human and mouse cells. In contrast to S. cerevisiae, neither E. coli nor the mammalian cells tested were able to form 13C6-Q when cultured in the presence of 13C6-pABA. However, E. coli cells treated with 13C6-pABA generated 13C6-ring-labeled forms of 3-octaprenyl-4-aminobenzoic acid, 2-octaprenyl-aniline, and 3-octaprenyl-2-aminophenol, suggesting UbiA, UbiD, UbiX, and UbiI are capable of using pABA or pABA-derived intermediates as substrates. E. coli, S. cerevisiae, and human and mouse cells cultured in the presence of 13C6-resveratrol or 13C6-coumarate were able to synthesize 13C6-Q. Future evaluation of the physiological and pharmacological responses to dietary polyphenols should consider their metabolism to Q. PMID:25681964

Characteristics of high-purity Teflon vial for 14C measurement in old tree rings

NASA Astrophysics Data System (ADS)

Sakurai, H.; Saswaki, Y.; Matsumoto, T.; Aoki, T.; Kato, W.; Gandou, T.; Gunji, S.; Tokanai, F.

2003-06-01

14C concentration in single-year tree rings of an old cedar of ca. 2500 years ago is measured to investigate the 11-yr periodicity of solar activity. Our highly accurate 14C measuring system is composed of a benzene synthesizer capable of producing a large quantity (10 g) of benzene and a Quantulus 1220™ liquid scintillation counting system. The accuracy is less than 0.2% for measurements of 14C concentration. The benzene sample is contained in a high-purity Teflon/copper-counting vial (20 ml) manufactured by Wallac Oy Company. We found a vial with an irregular copper cap for the measurements of 11 tree rings. The behavior of the vial with the irregular cap was investigated. The Teflon sheet inside the cap plays an important role in achieving stable measurement. The rate of volatilization of the benzene was less than 0.35 mg/day for vials with ordinary caps. This results in the volatilization rate of 0.003% for 10.5 g of benzene and hence guarantees measurement at an accuracy of 0.2% for 70 days.

The Enceladus Ring

NASA Technical Reports Server (NTRS)

2006-01-01

[figure removed for brevity, see original site] The Enceladus Ring (labeled)

This excellent view of the faint E ring -- a ring feature now known to be created by Enceladus -- also shows two of Saturn's small moons that orbit within the ring, among a field of stars in the background.

The E ring extends from three to eight Saturn radii -- about 180,000 kilometers (118,000 miles) to 482,000 kilometers (300,000 miles). Its full extent is not visible in this view.

Calypso (22 kilometers, or 14 miles across) and Helene (32 kilometers, or 20 miles across) orbit within the E ring's expanse. Helene skirts the outer parts of the E ring, but here it is projected in front of a region deeper within the ring.

Calypso and Helene are trojan satellites, or moons that orbit 60 degrees in front or behind a larger moon. Calypso is a Tethys trojan and Helene is a trojan of Dione.

An interesting feature of note in this image is the double-banded appearance of the E-ring, which is created because the ring is somewhat fainter in the ringplane than it is 500-1,000 kilometers (300-600 miles) above and below the ringplane. This appearance implies that the particles in this part of the ring have nonzero inclinations (a similar affect is seen in Jupiter's gossamer ring). An object with a nonzero inclination does not orbit exactly at Saturn's ringplane. Instead, its orbit takes it above and below the ringplane. Scientists are not entirely sure why the particles should have such inclinations, but they are fairly certain that the reason involves Enceladus.

One possible explanation is that all the E ring particles come from the plume of icy material that is shooting due south out of the moon's pole. This means all of the particles are created with a certain velocity out of the ringplane, and then they orbit above and below that plane.

Another possible explanation is that Enceladus produces particles with a range of speeds, but the moon gravitationally

Development of Cone Wedge Ring Expansion Test to Evaluate Mechanical Properties of Clad Tubing Structure

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

Wang, Jy-An John

To determine the hoop tensile properties of irradiated fuel cladding in a hot cell, a cone wedge ring expansion test method was developed. A four-piece wedge insert was designed with tapered angles matched to the cone shape of a loading piston. The ring specimen was expanded in the radial direction by the lateral expansion of the wedges under the downward movement of the piston. The advantages of the proposed method are that implementation of the test setup in a hot cell is simple and easy, and that it enables a direct strain measurement of the test specimen from the piston’smore » vertical displacement soon after the wedge-clad contact resistance is initiated.« less

13C multiplet nuclear magnetic resonance relaxation-derived ring puckering and backbone dynamics in proline-containing glycine-based peptides.

PubMed Central

Mikhailov, D; Daragan, V A; Mayo, K H

1995-01-01

13CH2-multiplet nuclear magnetic resonance relaxation studies on proline (P)-containing glycine (G)-based peptides, GP, PG, GPG, PGG, and GPGG, provided numerous dipolar auto- and cross-correlation times for various motional model analyses of backbone and proline-ring bond rotations. Molecular dynamics simulations and bond rotation energy profiles were calculated to assess which motions could contribute most to observed relaxation phenomena. Results indicate that proline restricts backbone psi 1, psi 2, and phi 2 motions by 50% relative to those found for a polyglycine control peptide. psi 1 rotations are more restricted in the trans-proline isomer state than in the cis form. A two-state jump model best approximates proline ring puckering which in water could occur either by the C gamma endo-exo or by the C2 interconversion mechanism. The temperature dependence (5 degrees to 75 degrees C) of C beta, and C gamma, and C delta angular changes is rather flat, suggesting a near zero enthalpic contribution to the ring puckering process. In lower dielectric solvents, dimethylsulfoxide and methanol, which may mimic the hydrophobic environment within a protein, the endo-exo mechanism is preferred. PMID:7787039

Atomistic simulations indicate the c-subunit ring of the F1Fo ATP synthase is not the mitochondrial permeability transition pore

PubMed Central

Zhou, Wenchang; Marinelli, Fabrizio; Nief, Corrine; Faraldo-Gómez, José D

2017-01-01

Pathological metabolic conditions such as ischemia induce the rupture of the mitochondrial envelope and the release of pro-apoptotic proteins, leading to cell death. At the onset of this process, the inner mitochondrial membrane becomes depolarized and permeable to osmolytes, proposedly due to the opening of a non-selective protein channel of unknown molecular identity. A recent study purports that this channel, referred to as Mitochondrial Permeability Transition Pore (MPTP), is formed within the c-subunit ring of the ATP synthase, upon its dissociation from the catalytic domain of the enzyme. Here, we examine this claim for two c-rings of different lumen width, through calculations of their ion conductance and selectivity based on all-atom molecular dynamics simulations. We also quantify the likelihood that the lumen of these c-rings is in a hydrated, potentially conducting state rather than empty or blocked by lipid molecules. These calculations demonstrate that the structure and biophysical properties of a correctly assembled c-ring are inconsistent with those attributed to the MPTP. DOI: http://dx.doi.org/10.7554/eLife.23781.001 PMID:28186490

40 CFR Table C-3 to Subpart C of... - Test Specifications for Pb in TSP and Pb in PM 10 Methods

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test Specifications for Pb in TSP and Pb in PM 10 Methods C Table C-3 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL..., Subpt. C, Table C-3 Table C-3 to Subpart C of Part 53—Test Specifications for Pb in TSP and Pb in PM 10...

40 CFR Table C-3 to Subpart C of... - Test Specifications for Pb in TSP and Pb in PM 10 Methods

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test Specifications for Pb in TSP and Pb in PM 10 Methods C Table C-3 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL..., Subpt. C, Table C-3 Table C-3 to Subpart C of Part 53—Test Specifications for Pb in TSP and Pb in PM 10...

40 CFR Table C-3 to Subpart C of... - Test Specifications for Pb in TSP and Pb in PM10 Methods

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test Specifications for Pb in TSP and Pb in PM10 Methods C Table C-3 to Subpart C of Part 53 Protection of Environment ENVIRONMENTAL..., Subpt. C, Table C-3 Table C-3 to Subpart C of Part 53—Test Specifications for Pb in TSP and Pb in PM10...

Tree-ring δ13C and δ18O, leaf δ13C and wood and leaf N status demonstrate tree growth strategies and predict susceptibility to disturbance

PubMed Central

Billings, S.A.; Boone, A.S.; Stephen, F.M.

2016-01-01

Understanding how tree growth strategies may influence tree susceptibility to disturbance is an important goal, especially given projected increases in diverse ecological disturbances this century. We use growth responses of tree rings to climate, relationships between tree-ring stable isotopic signatures of carbon (δ13C) and oxygen (δ18O), wood nitrogen concentration [N], and contemporary leaf [N] and δ13C values to assess potential historic drivers of tree photosynthesis in dying and apparently healthy co-occurring northern red oak (Quercus rubra L. (Fagaceae)) during a region-wide oak decline event in Arkansas, USA. Bole growth of both healthy and dying trees responded negatively to drought severity (Palmer Drought Severity Index) and temperature; healthy trees exhibited a positive, but small, response to growing season precipitation. Contrary to expectations, tree-ring δ13C did not increase with drought severity. A significantly positive relationship between tree-ring δ13C and δ18O was evident in dying trees (P < 0.05) but not in healthy trees. Healthy trees’ wood exhibited lower [N] than that of dying trees throughout most of their lives (P < 0.05), and we observed a significant, positive relationship (P < 0.05) in healthy trees between contemporary leaf δ13C and leaf N (by mass), but not in dying trees. Our work provides evidence that for plants in which strong relationships between δ13C and δ18O are not evident, δ13C may be governed by plant N status. The data further imply that historic photosynthesis in healthy trees was linked to N status and, perhaps, C sink strength to a greater extent than in dying trees, in which tree-ring stable isotopes suggest that historic photosynthesis was governed primarily by stomatal regulation. This, in turn, suggests that assessing the relative dominance of photosynthetic capacity vs stomatal regulation as drivers of trees’ C accrual may be a feasible means of predicting tree responses to some

High Temperature Capacitive Pressure Sensor Employing a SiC Based Ring Oscillator

NASA Technical Reports Server (NTRS)

Meredith, Roger D.; Neudeck, Philip G.; Ponchak, George E.; Beheim, Glenn M.; Scardelletti, Maximilian; Jordan, Jennifer L.; Chen, Liang-Yu; Spry, David J.; Krawowski, Michael J.; Hunter, Gary W.

2011-01-01

In an effort to develop harsh environment electronic and sensor technologies for aircraft engine safety and monitoring, we have used capacitive-based pressure sensors to shift the frequency of a SiC-electronics-based oscillator to produce a pressure-indicating signal that can be readily transmitted, e.g. wirelessly, to a receiver located in a more benign environment. Our efforts target 500 C, a temperature well above normal operating conditions of commercial circuits but within areas of interest in aerospace engines, deep mining applications and for future missions to the Venus atmosphere. This paper reports for the first time a ring oscillator circuit integrated with a capacitive pressure sensor, both operating at 500 C. This demonstration represents a significant step towards a wireless pressure sensor that can operate at 500 C and confirms the viability of 500 C electronic sensor systems.

Moonlet induced wakes in planetary rings: Analytical model including eccentric orbits of moon and ring particles

NASA Astrophysics Data System (ADS)

Seiß, M.; Spahn, F.; Schmidt, Jürgen

2010-11-01

Saturn's rings host two known moons, Pan and Daphnis, which are massive enough to clear circumferential gaps in the ring around their orbits. Both moons create wake patterns at the gap edges by gravitational deflection of the ring material (Cuzzi, J.N., Scargle, J.D. [1985]. Astrophys. J. 292, 276-290; Showalter, M.R., Cuzzi, J.N., Marouf, E.A., Esposito, L.W. [1986]. Icarus 66, 297-323). New Cassini observations revealed that these wavy edges deviate from the sinusoidal waveform, which one would expect from a theory that assumes a circular orbit of the perturbing moon and neglects particle interactions. Resonant perturbations of the edges by moons outside the ring system, as well as an eccentric orbit of the embedded moon, may partly explain this behavior (Porco, C.C., and 34 colleagues [2005]. Science 307, 1226-1236; Tiscareno, M.S., Burns, J.A., Hedman, M.M., Spitale, J.N., Porco, C.C., Murray, C.D., and the Cassini Imaging team [2005]. Bull. Am. Astron. Soc. 37, 767; Weiss, J.W., Porco, C.C., Tiscareno, M.S., Burns, J.A., Dones, L. [2005]. Bull. Am. Astron. Soc. 37, 767; Weiss, J.W., Porco, C.C., Tiscareno, M.S. [2009]. Astron. J. 138, 272-286). Here we present an extended non-collisional streamline model which accounts for both effects. We describe the resulting variations of the density structure and the modification of the nonlinearity parameter q. Furthermore, an estimate is given for the applicability of the model. We use the streamwire model introduced by Stewart (Stewart, G.R. [1991]. Icarus 94, 436-450) to plot the perturbed ring density at the gap edges. We apply our model to the Keeler gap edges undulated by Daphnis and to a faint ringlet in the Encke gap close to the orbit of Pan. The modulations of the latter ringlet, induced by the perturbations of Pan (Burns, J.A., Hedman, M.M., Tiscareno, M.S., Nicholson, P.D., Streetman, B.J., Colwell, J.E., Showalter, M.R., Murray, C.D., Cuzzi, J.N., Porco, C.C., and the Cassini ISS team [2005]. Bull. Am

Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C 2-symmetric building block: a strategy for the synthesis of decanolide natural products.

PubMed

Schmidt, Bernd; Kunz, Oliver

2013-01-01

Starting from the conveniently available ex-chiral pool building block (R,R)-hexa-1,5-diene-3,4-diol, the ten-membered ring lactones stagonolide E and curvulide A were synthesized using a bidirectional olefin-metathesis functionalization of the terminal double bonds. Key steps are (i) a site-selective cross metathesis, (ii) a highly diastereoselective extended tethered RCM to furnish a (Z,E)-configured dienyl carboxylic acid and (iii) a Ru-lipase-catalyzed dynamic kinetic resolution to establish the desired configuration at C9. Ring closure was accomplished by macrolactonization. Curvulide A was synthesized from stagonolide E through Sharpless epoxidation.

Using Testlet Response Theory to Examine Local Dependence in C-Tests

ERIC Educational Resources Information Center

Eckes, Thomas; Baghaei, Purya

2015-01-01

C-tests are gap-filling tests widely used to assess general language proficiency for purposes of placement, screening, or provision of feedback to language learners. C-tests consist of several short texts in which parts of words are missing. We addressed the issue of local dependence in C-tests using an explicit modeling approach based on testlet…

AXAF VETA-I mirror ring focus measurements

NASA Technical Reports Server (NTRS)

Tananbaum, H. D.; Zhao, P.

1994-01-01

The AXAF VETA-I mirror ring focus measurements were made with an HRI (microchannel plate) X-ray detector. The ring focus is a sharply focused ring formed by X-rays before they reach the VEAT-I focal plane. It is caused by spherical aberrations due to the finite source distance and the despace in the VETA-I test. The ring focus test reveals some aspects fo the test system distortions and the mirror surface figure which are difficult or impossible to detect at the focal plane. The test results show periodic modulations of the ring radius and width which could be caused by gravity, thermal, and/or epoxy shrinkage distortions. The strongest component of the modulation had a 12-fold symmetry, because these distortions were exerted on the mirror through 12 flexures of the VETA-I mount. Ring focus models were developed to simulate the ring image. The models were compared with the data to understand the test system distortions and the mirror glass imperfection. Further studies will be done to complete this work. The ring focus measurement is a very powerful test. We expect that a similar test for the finally assembled mirror of AXAD-I will be highly valuable.

Subunit rotation of ATP synthase embedded in membranes: a or β subunit rotation relative to the c subunit ring

PubMed Central

Nishio, Kazuaki; Iwamoto-Kihara, Atsuko; Yamamoto, Akitsugu; Wada, Yoh; Futai, Masamitsu

2002-01-01

ATP synthase FoF1 (α3β3γδɛab2c10–14) couples an electrochemical proton gradient and a chemical reaction through the rotation of its subunit assembly. In this study, we engineered FoF1 to examine the rotation of the catalytic F1 β or membrane sector Fo a subunit when the Fo c subunit ring was immobilized; a biotin-tag was introduced onto the β or a subunit, and a His-tag onto the c subunit ring. Membrane fragments were obtained from Escherichia coli cells carrying the recombinant plasmid for the engineered FoF1 and were immobilized on a glass surface. An actin filament connected to the β or a subunit rotated counterclockwise on the addition of ATP, and generated essentially the same torque as one connected to the c ring of FoF1 immobilized through a His-tag linked to the α or β subunit. These results established that the γɛc10–14 and α3β3δab2 complexes are mechanical units of the membrane-embedded enzyme involved in rotational catalysis. PMID:12357031

Ring-diameter Ratios for Multi-ring Basins Average 2.0(0.5)D

NASA Technical Reports Server (NTRS)

Pike, R. J.; Spudis, P. D.

1985-01-01

The spacing of the concentric rings of planetary impact basins was studied. It is shown that a radial increment of x (sup 0.5) D, where x is about 2.0 and D = ring diameter, separates both (1) adjacent least-squares groups of rings and arcs of multi-ring basins on Mars, Mercury, and the Moon; and (2) adjacent rings of individual basins on the three planets. Statistics for ratios of ring diameters are presented, the first and most-applied parameter of ring spacing. It is found that ratios excluding rings flanking the main ring also have a mean spacing increment of about 2.0. Ratios including such rings, as for the least-squares groups, and (1) above, have a larger increment, averaging 2.1. The F-test indicates, that these spacings of basin ring locations, and mode of ring formation are controlled by the mechanics of the impact event itself, rather than by crustal properties.

Ring flips revisited: (13)C relaxation dispersion measurements of aromatic side chain dynamics and activation barriers in basic pancreatic trypsin inhibitor.

PubMed

Weininger, Ulrich; Modig, Kristofer; Akke, Mikael

2014-07-22

Intramolecular motions of proteins are critical for biological function. Transient structural fluctuations underlie a wide range of processes, including enzyme catalysis, ligand binding to buried sites, and generic protein motions, such as 180° rotation of aromatic side chains in the protein interior, but remain poorly understood. Understanding the dynamics and molecular nature of concerted motions requires characterization of their rates and energy barriers. Here we use recently developed (13)C transverse relaxation dispersion methods to improve our current understanding of aromatic ring flips in basic pancreatic trypsin inhibitor (BPTI). We validate these methods by benchmarking ring-flip rates against the three previously characterized cases in BPTI, namely, Y23, Y35, and F45. Further, we measure conformational exchange for one additional aromatic ring, F22, which can be interpreted in terms of a flip rate of 666 s(-1) at 5 °C. Upon inclusion of our previously reported result that Y21 also flips slowly [Weininger, U., et al. (2013) J. Phys. Chem. B 117, 9241-9247], the (13)C relaxation dispersion experiments thus reveal relatively slow ring-flip rates for five of eight aromatic residues in BPTI. These results are in contrast with previous reports, which have estimated that all rings, except Y23, Y35, and F45, flip with a high rate at ambient temperature. The (13)C relaxation dispersion data result in an updated rank order of ring-flip rates in BPTI, which agrees considerably better with that estimated from a recent 1 ms molecular dynamics trajectory than do previously published NMR data. However, significant quantitative differences remain between experiment and simulation, in that the latter yields flip rates that are in many cases too fast by 1-2 orders of magnitude. By measuring flip rates across a temperature range of 5-65 °C, we determined the activation barriers of ring flips for Y23, Y35, and F45. Y23 and F45 have identical activation parameters

Testing the assumption of annual shell ring deposition in freshwater mussels

Treesearch

Wendell R. Haag; Amy M. Commens-Carson

2008-01-01

We tested the assumption of annual shell ring deposition by freshwater mussels in three rivers using 17 species. In 2000, we notched shell margins, returned animals to the water, and retrieved them in 2001. In 2003, we measured shells, affixed numbered tags, returned animals, and retrieved them in 2004 and 2005. We validated deposition of a single internal annulus per...

Total synthesis of bryostatins: the development of methodology for the atom-economic and stereoselective synthesis of the ring C subunit.

PubMed

Trost, Barry M; Frontier, Alison J; Thiel, Oliver R; Yang, Hanbiao; Dong, Guangbin

2011-08-22

Bryostatins, a family of structurally complicated macrolides, exhibit an exceptional range of biological activities. The limited availability and structural complexity of these molecules makes development of an efficient total synthesis particularly important. This article describes our initial efforts towards the total synthesis of bryostatins, in which chemoselective and atom-economical methods for the stereoselective assembly of the ring C subunit were developed. A Pd-catalyzed tandem alkyne-alkyne coupling/6-endo-dig cyclization sequence was explored and successfully pursued in the synthesis of a dihydropyran ring system. Elaboration of this methodology ultimately led to a concise synthesis of the ring C subunit of bryostatins. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Saturn's E Ring in Ultraviolet Light

NASA Technical Reports Server (NTRS)

2002-01-01

Visible from Earth only at times of ring plane crossing, Saturn's tenuous E Ring was discovered during the 1966 crossings and imaged again in 1980. From these observations, its color is known to be distinctively blue. The E Ring was captured in ultraviolet light for the first time in this image taken with HST's Wide Field and Planetary Camera on 9 August 1995. Five individual images taken with a broadband 3000 A filter were combined, amounting to a total exposure time of 2200 sec. Shorter exposure images were also obtained with blue, red and infrared filters in order to characterize the ring's color. The peak brightness of the E Ring occurs at 3.9 Saturn radii (235,000 km), coinciding with the orbit of Enceladus. In the HST images it can be traced out to a maximum distance of approximately 8 Rs (480,000 km). The vertical thickness of the ring, on the other hand, is smallest at Enceladus' orbit, with the ring puffing up noticeably at larger distances to 15,000 km or more thick. Also visible in this image, between the E Ring and the overexposed outermost part of the main rings near the lower edge of the frame, is the tenuous, thin, 6000 km-wide G Ring at 2.8 Rs (170,000 km). This is among the first earth-based observations of the G Ring, which was discovered by the Pioneer 11 spacecraft in 1979. Noticeably thinner than the E Ring and more neutral in color, the G Ring is thought to be composed of larger, macroscopic particles, and to pose a significant hazard to spacecraft. The faint diagonal band in the lower right part of the image is due to diffracted light from the heavily-overexposed planet. Credit: Phil Nicholson (Cornell University), Mark Showalter (NASA-Ames/Stanford) and NASA

Effect of temperature and O-ring gland finish on sealing ability of Viton V747-75

NASA Technical Reports Server (NTRS)

Lach, Cynthia L.

1993-01-01

As a part of the redesign project of the Space Shuttle solid rocket motor (SRM) following the Challenger accident, the field joint was redesigned to minimize the relative joint motion caused by internal motor pressurization during ignition. The O-ring seals and glands for the field joint were designed both to accommodate structural deflections and to promote pressure-assisted sealing. Tests were conducted in various face seal fixtures to evaluate the ability of Viton V747-75 O-rings to seal for a range of temperatures and surface finishes of the redesigned O-ring gland. The effect of surface finish on the sealing performance and wear characteristics of the O-rings was evaluated during simulated launch conditions that included low-frequency vibrations, gap openings, and rapid pressurizations. The effect of contamination on the sealing performance was also investigated. The O-rings sealed throughout the 75 deg F leak check test and for the seal tests from 50 deg F to 120 deg F for the range of surface finishes investigated. Although abrasions were found in the O-rings from pressurization against the rougher finishes, these abrasions were not detrimental to sealing. Below 50 deg F, Viton V747-75 O-rings were insufficiently resilient to track the test gap opening.

Biological suppression of potato ring rot by fluorescent pseudomonads.

PubMed Central

de la Cruz, A R; Poplawsky, A R; Wiese, M V

1992-01-01

Three strains of fluorescent pseudomonads (IS-1, IS-2, and IS-3) isolated from potato underground stems with roots showed in vitro antibiosis against 30 strains of the ring rot bacterium Clavibacter michiganensis subsp. sepedonicus. On the basis of morphological and biochemical tests and fatty acid analysis, IS-1 and IS-2 were identified as Pseudomonas aureofaciens and IS-3 was identified as P. fluorescens biovar III. IS-1 was the most inhibitory to C. michiganensis subsp. sepedonicus strains in vitro, followed by IS-3 and IS-2. Suppression of ring rot by these antagonists was demonstrated in greenhouse trials with stem-cultured potato (cv. Russet Burbank) seedlings. Although each antagonist significantly reduced C. michiganensis subsp. sepedonicus populations, only IS-1 reduced infection by C. michiganensis subsp. sepedonicus. In a second experiment, treatment with IS-1 (10(9) CFU/ml) significantly reduced ring rot infection by 23.4 to 26.7% after 5 to 8 weeks. The average C. michiganensis subsp. sepedonicus population was also significantly reduced by 50 to 52%. Application of different combinations of antagonist strains was not more effective than single-strain treatment. Images PMID:1622275

Experimental Durability Testing of 4H SiC JFET Integrated Circuit Technology at 727 Degrees Centigrade

NASA Technical Reports Server (NTRS)

Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Chang, Carl W.; Lukco, Dorothy; Beheim, Glenn M.

2016-01-01

We have reported SiC integrated circuits (ICs) with two levels of metal interconnect that have demonstrated prolonged operation for thousands of hours at their intended peak ambient operational temperature of 500 degrees Centigrade. However, it is recognized that testing of semiconductor microelectronics at temperatures above their designed operating envelope is vital to qualification. Towards this end, we previously reported operation of a 4H-SiC JFET IC ring oscillator on an initial fast thermal ramp test through 727 degrees Centigrade. However, this thermal ramp was not ended until a peak temperature of 880 degrees Centigrade (well beyond failure) was attained. Further experiments are necessary to better understand failure mechanisms and upper temperature limit of this extreme-temperature capable 4H-SiC IC technology.Here we report on additional experimental testing of custom-packaged 4H-SiC JFET IC devices at temperatures above 500 degrees Centigrade. In one test, the temperature was ramped and then held at 727 degrees Centigrade, and the devices were periodically measured until electrical failure was observed. A 4H-SiC JFET on this chip electrically functioned with little change for around 25 hours at 727 degrees Centigrade before rapid increases in device resistance caused failure. In a second test, devices from our next generation 4H-SiC JFET ICs were ramped up and then held at 700 degrees Centigrade (which is below the maximum deposition temperature of the dielectrics). Three ring oscillators functioned for 8 hours at this temperature before degradation. In a third experiment, an alternative die attach of gold paste and package lid was used, and logic circuit operation was demonstrated for 143.5 hours at 700 degrees Centigrade.

Part C Updates: 9th Edition

ERIC Educational Resources Information Center

Danaher, Joan; Goode, Sue; Lazara, Alex

2007-01-01

"Part C Updates" is a compilation of information on various aspects of the Early Intervention Program for Infants and Toddlers with Disabilities (Part C) of the Individuals with Disabilities Education Act (IDEA). This is the ninth volume in a series of compilations, which included two editions of Part H Updates, the former name of the…

Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS

NASA Astrophysics Data System (ADS)

Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.

2010-12-01

Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

The hypermorph FtsA* protein has an in vivo role in relieving the Escherichia coli proto-ring block caused by excess ZapC+

PubMed Central

Ortiz, Cristina; Casanova, Mercedes; Palacios, Pilar

2017-01-01

Assembly of the proto-ring, formed by the essential FtsZ, FtsA and ZipA proteins, and its progression into a divisome, are essential events for Escherichia coli division. ZapC is a cytoplasmic protein that belongs to a group of non-essential components that assist FtsZ during proto-ring assembly. Any overproduction of these proteins leads to faulty FtsZ-rings, resulting in a cell division block. We show that ZapC overproduction can be counteracted by an excess of the ZipA-independent hypermorph FtsA* mutant, but not by similar amounts of wild type FtsA+. An excess of FtsA+ allowed regular spacing of the ZapC-blocked FtsZ-rings, but failed to promote recruitment of the late-assembling proteins FtsQ, FtsK and FtsN and therefore, to activate constriction. In contrast, overproduction of FtsA*, besides allowing correct FtsZ-ring localization at midcell, restored the ability of FtsQ, FtsK and FtsN to be incorporated into active divisomes. PMID:28877250

49 CFR Appendix C to Part 173 - Procedure for Base-level Vibration Testing

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 2 2012-10-01 2012-10-01 false Procedure for Base-level Vibration Testing C... Base-level Vibration Testing Base-level vibration testing shall be conducted as follows: 1. Three... platform. 4. Immediately following the period of vibration, each package shall be removed from the platform...

400 years of summer climatic conditions in the N Carpathian Mts. (eastern Europe) based on O and C stable isotopes in Pinus Cembra L tree rings

NASA Astrophysics Data System (ADS)

Nagavciuc, Viorica; Popa, Ionel; Kern, Zoltán; Persoiu, Aurel

2016-04-01

For a better understanding of how the climate is changing and how the environment responds to these changes, it is necessary to understand how the climate has varied in the past. Romania's virgin forests have a great potential to obtain long tree-ring chronologies with annual resolution; but so far, only a few studies resulted in quantitative paleoclimatic reconstructions. In this context, the aim of this study is 1) to calibrate the relationship between the stable isotopes of oxygen and carbon in tree rings and the main climatic parameters and determine the potential of Pinus cembra (Cǎlimani Mts., N Romania, Eastern Europe) for paleoclimatic reconstructions; 2) to provide the first palaeoclimatic reconstitution in Romania based on the isotopic composition of oxygen and carbon in tree ring cellulose, and 3) to test the hypothesis that nearby sulphur mines have not altered the climatic signal recorded by the stable isotopic composition of tree rings, contrary to the similar signal recorded by TRW. For this study, we have analysed wood samples of Swiss stone pine (Pinus cembra L.) from living and dead trees from Cǎlimani Mts., NE Romania, aged between 1600 and 2012 AD. The isotopic composition of oxygen and carbon from the cellulose was analysed at the Institute for Geological and Geochemical Research, Budapest, Hungary, using a high-temperature pyrolysis system (Thermo Quest TC-EA) coupled to an isotope ratio mass spectrometer (Thermo Finningan Delta V) following a ring by ring (i.e., non-pooled) approach. The average level of δ18O and δ13C in cellulose for the period 1600-2012 was 28.83‰ and -22.63 ‰. The tree ring cellulose δ18O and δ13C values showed a strong positive correlation with maximum air temperature (r = 0.6 for δ18O and r = 0.5 for δ13C), mean temperature (r = 0.6 for δ18O and r = 0.45 for δ13C), and sunshine duration (r = 0.69 for δ18O) and negatively correlated with precipitation amount (r = -0.5 for δ18O and r = 0.3 for δ13C) and

Roller Testing to Mimic Damage of the ISS SARJ Ring and Durability Test to Simulate Fifteen Years of SARJ Operation Using the Damaged Surface

NASA Technical Reports Server (NTRS)

Krantz, Timothy L.; Elchert, Justin P.; DellaCorte, Christopher; Dube, Michael J.

2016-01-01

The International Space Station's starboard Solar Alpha Rotary Joint (SARJ) experienced a breakdown of the joint's race ring surface. The starboard SARJ mechanism was cleaned and lubricated with grease. To provide some guidance on the expected behavior of the damaged SARJ ring with continued operations, experiments were conducted using rollers and a vacuum roller test rig. The approach of the experimental work involved three main steps: (1) initiate damage using conditions representative of the SARJ with inadequate lubrication; (2) propagate the damage by operating the test rollers without lubrication; and (3) assess the durability of the roller by testing to simulate the equivalent of 15 years of SARJ operation on the damaged surface assuming adequate grease lubrication. During the rig testing, additional and/or replacement grease was introduced at regular intervals to maintain good lubrication in the rig. The damage to the nitride layer continued even after application of grease. The grease lubrication proved to be effective for limiting the value of the axial force that can be developed. Limiting the axial force on the SARJ mechanism is important since the larger the axial force the more concentrated the load pressure becomes on the blend-radius location on the SARJ roller. After the testing simulating 15 years of SARJ operations, the wear depths were the order of 0.2 mm for the nitrided 15-5 roller and the order of 0.06 mm for the mating 440C roller. Metallographic inspections were done to search for indications of impending fatigue or other fracture indications that might eventually propagate and cause structural failure. There were no indications or features found that could eventually compromise structural integrity.

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specification

Code of Federal Regulations, 2010 CFR

2010-07-01

... Measurements Required, and Maximum Discrepancy Specification C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges..., June 22, 2010, table C-1 to subpart C was revised, effective Aug. 23, 2010. For the convenience of the...

One ring or two? Determination of ring number in carotenoids by lycopene epsilon-cyclases.

PubMed

Cunningham, F X; Gantt, E

2001-02-27

Carotenoids in the photosynthetic membranes of plants typically contain two beta-rings (e.g., beta-carotene and zeaxanthin) or one epsilon- and one beta-ring (e.g., lutein). Carotenoids with two epsilon-rings are uncommon. We reported earlier that the Arabidopsis thaliana lycopene epsilon-cyclase (LCYe) adds one epsilon-ring to the symmetrical linear substrate lycopene, whereas the structurally related lycopene beta-cyclase (LCYb) adds two beta-rings. Here we describe a cDNA encoding LCYe in romaine lettuce (Lactuca sativa var. romaine), one of the few plant species known to accumulate substantial quantities of a carotenoid with two epsilon-rings: lactucaxanthin. The product of the lettuce cDNA, similar in sequence to the Arabidopsis LCYe (77% amino acid identity), efficiently converted lycopene into the bicyclic epsilon-carotene in a heterologous Escherichia coli system. Regions of the lettuce and Arabidopsis epsilon-cyclases involved in the determination of ring number were mapped by analysis of chimeric epsilon-cyclases constructed by using an inverse PCR approach. A single amino acid was found to act as a molecular switch: lettuce LCYe mutant H457L added only one epsilon-ring to lycopene, whereas the complementary Arabidopsis LCYe mutant, L448H, added two epsilon-rings. An R residue in this position also yields a bi-epsilon-cyclase for both the lettuce and Arabidopsis enzymes. Construction and analysis of chimera of related enzymes with differing catalytic activities provide an informative approach that may be of particular utility for studying membrane-associated enzymes that cannot easily be crystallized or modeled to existing crystal structures.

One ring or two? Determination of ring number in carotenoids by lycopene ɛ-cyclases

PubMed Central

Cunningham, Francis X.; Gantt, Elisabeth

2001-01-01

Carotenoids in the photosynthetic membranes of plants typically contain two β-rings (e.g., β-carotene and zeaxanthin) or one ɛ- and one β-ring (e.g., lutein). Carotenoids with two ɛ-rings are uncommon. We reported earlier that the Arabidopsis thaliana lycopene ɛ-cyclase (LCYe) adds one ɛ-ring to the symmetrical linear substrate lycopene, whereas the structurally related lycopene β-cyclase (LCYb) adds two β-rings. Here we describe a cDNA encoding LCYe in romaine lettuce (Lactuca sativa var. romaine), one of the few plant species known to accumulate substantial quantities of a carotenoid with two ɛ-rings: lactucaxanthin. The product of the lettuce cDNA, similar in sequence to the Arabidopsis LCYe (77% amino acid identity), efficiently converted lycopene into the bicyclic ɛ-carotene in a heterologous Escherichia coli system. Regions of the lettuce and Arabidopsis ɛ-cyclases involved in the determination of ring number were mapped by analysis of chimeric ɛ-cyclases constructed by using an inverse PCR approach. A single amino acid was found to act as a molecular switch: lettuce LCYe mutant H457L added only one ɛ-ring to lycopene, whereas the complementary Arabidopsis LCYe mutant, L448H, added two ɛ-rings. An R residue in this position also yields a bi-ɛ-cyclase for both the lettuce and Arabidopsis enzymes. Construction and analysis of chimera of related enzymes with differing catalytic activities provide an informative approach that may be of particular utility for studying membrane-associated enzymes that cannot easily be crystallized or modeled to existing crystal structures. PMID:11226339

Rho1- and Pkc1-dependent phosphorylation of the F-BAR protein Syp1 contributes to septin ring assembly

PubMed Central

Merlini, Laura; Bolognesi, Alessio; Juanes, Maria Angeles; Vandermoere, Franck; Courtellemont, Thibault; Pascolutti, Roberta; Séveno, Martial; Barral, Yves; Piatti, Simonetta

2015-01-01

In many cell types, septins assemble into filaments and rings at the neck of cellular appendages and/or at the cleavage furrow to help compartmentalize the plasma membrane and support cytokinesis. How septin ring assembly is coordinated with membrane remodeling and controlled by mechanical stress at these sites is unclear. Through a genetic screen, we uncovered an unanticipated link between the conserved Rho1 GTPase and its effector protein kinase C (Pkc1) with septin ring stability in yeast. Both Rho1 and Pkc1 stabilize the septin ring, at least partly through phosphorylation of the membrane-associated F-BAR protein Syp1, which colocalizes asymmetrically with the septin ring at the bud neck. Syp1 is displaced from the bud neck upon Pkc1-dependent phosphorylation at two serines, thereby affecting the rigidity of the new-forming septin ring. We propose that Rho1 and Pkc1 coordinate septin ring assembly with membrane and cell wall remodeling partly by controlling Syp1 residence at the bud neck. PMID:26179915

Circadian clock protein KaiC forms ATP-dependent hexameric rings and binds DNA

PubMed Central

Mori, Tetsuya; Saveliev, Sergei V.; Xu, Yao; Stafford, Walter F.; Cox, Michael M.; Inman, Ross B.; Johnson, Carl H.

2002-01-01

KaiC from Synechococcus elongatus PCC 7942 (KaiC) is an essential circadian clock protein in cyanobacteria. Previous sequence analyses suggested its inclusion in the RecA/DnaB superfamily. A characteristic of the proteins of this superfamily is that they form homohexameric complexes that bind DNA. We show here that KaiC also forms ring complexes with a central pore that can be visualized by electron microscopy. A combination of analytical ultracentrifugation and chromatographic analyses demonstrates that these complexes are hexameric. The association of KaiC molecules into hexamers depends on the presence of ATP. The KaiC sequence does not include the obvious DNA-binding motifs found in RecA or DnaB. Nevertheless, KaiC binds forked DNA substrates. These data support the inclusion of KaiC into the RecA/DnaB superfamily and have important implications for enzymatic activity of KaiC in the circadian clock mechanism that regulates global changes in gene expression patterns. PMID:12477935

Circadian clock protein KaiC forms ATP-dependent hexameric rings and binds DNA.

PubMed

Mori, Tetsuya; Saveliev, Sergei V; Xu, Yao; Stafford, Walter F; Cox, Michael M; Inman, Ross B; Johnson, Carl H

2002-12-24

KaiC from Synechococcus elongatus PCC 7942 (KaiC) is an essential circadian clock protein in cyanobacteria. Previous sequence analyses suggested its inclusion in the RecADnaB superfamily. A characteristic of the proteins of this superfamily is that they form homohexameric complexes that bind DNA. We show here that KaiC also forms ring complexes with a central pore that can be visualized by electron microscopy. A combination of analytical ultracentrifugation and chromatographic analyses demonstrates that these complexes are hexameric. The association of KaiC molecules into hexamers depends on the presence of ATP. The KaiC sequence does not include the obvious DNA-binding motifs found in RecA or DnaB. Nevertheless, KaiC binds forked DNA substrates. These data support the inclusion of KaiC into the RecADnaB superfamily and have important implications for enzymatic activity of KaiC in the circadian clock mechanism that regulates global changes in gene expression patterns.

Pair Past the Rings

NASA Image and Video Library

2010-03-04

Two of Saturn moons orbit beyond four of the planet rings in this image from NASA Cassini spacecraft. From the top right of the picture are the C, B , A, and thin F rings, the small moon Pandora and, near the middle of the image, the moon Enceladus.

Virtual Exploration of the Ring Systems Chemical Universe.

PubMed

Visini, Ricardo; Arús-Pous, Josep; Awale, Mahendra; Reymond, Jean-Louis

2017-11-27

Here, we explore the chemical space of all virtually possible organic molecules focusing on ring systems, which represent the cyclic cores of organic molecules obtained by removing all acyclic bonds and converting all remaining atoms to carbon. This approach circumvents the combinatorial explosion encountered when enumerating the molecules themselves. We report the chemical universe database GDB4c containing 916 130 ring systems up to four saturated or aromatic rings and maximum ring size of 14 atoms and GDB4c3D containing the corresponding 6 555 929 stereoisomers. Almost all (98.6%) of these ring systems are unknown and represent chiral 3D-shaped macrocycles containing small rings and quaternary centers reminiscent of polycyclic natural products. We envision that GDB4c can serve to select new ring systems from which to design analogs of such natural products. The database is available for download at www.gdb.unibe.ch together with interactive visualization and search tools as a resource for molecular design.

Simulated microbe removal around finger rings using different hand sanitation methods.

PubMed

Alur, Archana A; Rane, Madhavi J; Scheetz, James P; Lorenz, Douglas J; Gettleman, Lawrence

2009-09-01

It is our opinion that the CDC and the WHO have underestimated cross-contamination under examination gloves in dental clinics while wearing jewelry, such as finger rings. These agencies only "recommend" removing jewelry, and only washing hands for 15 seconds with soap and warm water before donning gloves. This study examined several washing procedures and finger rings using simulated microbes. A gloved rubber hand manikin was made and fitted with a fresh disposable vinyl glove. Four fingers were fitted with rings or no ring, dusted with simulated microbes, and washed with a scrub brush for 5, 15, and 25 seconds under 20 degrees C and 40 degrees C water alone, or with liquid hand soap. Light levels (in lux) of fluorescent powder before and after washing were measured and delta scores calculated for changes in light levels, equivalent to effectiveness of hand washing procedures. A full-factorial, 3-factor analysis of variance (ANOVA) was used to test for differences among levels of the three study factors-time, temperature, and soap use. Tukey's post hoc honestly significant difference (HSD) test was applied to significant factors to examine pair-wise differences between factor levels. It was found that the longer the hands with rings were washed with a scrub brush under flowing water, the more simulated microbes were removed. By 25 seconds, all methods were essentially the same. Simulated microbes were more difficult to remove from the palm compared to the back of the hand. The liquid hand soap used in this study was more effective with warm water than cold. When given a choice of washing with cold water up to 15 seconds, it would be preferable not to use soap to remove simulated microbes. Qualitatively, the outer surface of finger rings were more effectively cleaned than the crevice below the ring, and the ring with a stone setting appeared to accumulate and retain simulated microbes more than other rings. The most effective treatment was washing with warm water

Ring rotational speed trend analysis by FEM approach in a Ring Rolling process

NASA Astrophysics Data System (ADS)

Allegri, G.; Giorleo, L.; Ceretti, E.

2018-05-01

Ring Rolling is an advanced local incremental forming technology to fabricate directly precise seamless ring-shape parts with various dimensions and materials. In this process two different deformations occur in order to reduce the width and the height of a preform hollow ring; as results a diameter expansion is obtained. In order to guarantee a uniform deformation, the preform is forced toward the Driver Roll whose aim is to transmit the rotation to the ring. The ring rotational speed selection is fundamental because the higher is the speed the higher will be the axial symmetry of the deformation process. However, it is important to underline that the rotational speed will affect not only the final ring geometry but also the loads and energy needed to produce it. Despite this importance in industrial environment, usually, a constant value for the Driver Roll angular velocity is set so to result in a decreasing trend law for the ring rotational speed. The main risk due to this approach is not fulfilling the axial symmetric constrain (due to the diameter expansion) and to generate a high localized ring section deformation. In order to improve the knowledge about this topic in the present paper three different ring rotational speed trends (constant, linearly increasing and linearly decreasing) were investigated by FEM approach. Results were compared in terms of geometrical and dimensional analysis, loads and energies required.

A Photo-Favorskii Ring Contraction Reaction: The Effect of Ring Size

PubMed Central

Kammath, Viju Balachandran; Šolomek, Tomáš; Ngoy, Bokolombe Pitchou; Heger, Dominik; Klán, Petr; Rubina, Marina; Givens, Richard S.

2012-01-01

The effect of ring size on the photo-Favorskii induced ring-contraction reaction of the hydroxybenzocycloalkanonyl acetate and mesylate esters (7a–d, 8a–c) has provided new insight into the mechanism of the rearrangement. By monotonically decreasing the ring size in these cyclic derivatives, the increasing ring strain imposed on the formation of the elusive bicyclic spirocyclopropanone 20 results in a divergence away from rearrangement and toward solvolysis. Cycloalkanones of seven or eight carbons undergo a highly efficient photo-Favorskii rearrangement with ring contraction paralleling the photochemistry of p-hydroxyphenacyl esters. In contrast, the five-carbon ring does not rearrange but is diverted to the photosolvolysis channel avoiding the increased strain energy that would accompany the formation of the spirobicyclic ketone, the “Favorskii intermediate 20”. The six-carbon analogue demonstrates the bifurcation in reaction channels, yielding a solvent-sensitive mixture of both. Employing a combination of time-resolved absorption measurements, quantum yield determinations, isotopic labeling, and solvent variation studies coupled with theoretical treatment, a more comprehensive mechanistic description of the rearrangement has emerged. PMID:22686289

The Structure of Chariklo’s Rings from Stellar Occultations

NASA Astrophysics Data System (ADS)

Bérard, D.; Sicardy, B.; Camargo, J. I. B.; Desmars, J.; Braga-Ribas, F.; Ortiz, J.-L.; Duffard, R.; Morales, N.; Meza, E.; Leiva, R.; Benedetti-Rossi, G.; Vieira-Martins, R.; Gomes Júnior, A.-R.; Assafin, M.; Colas, F.; Dauvergne, J.-L.; Kervella, P.; Lecacheux, J.; Maquet, L.; Vachier, F.; Renner, S.; Monard, B.; Sickafoose, A. A.; Breytenbach, H.; Genade, A.; Beisker, W.; Bath, K.-L.; Bode, H.-J.; Backes, M.; Ivanov, V. D.; Jehin, E.; Gillon, M.; Manfroid, J.; Pollock, J.; Tancredi, G.; Roland, S.; Salvo, R.; Vanzi, L.; Herald, D.; Gault, D.; Kerr, S.; Pavlov, H.; Hill, K. M.; Bradshaw, J.; Barry, M. A.; Cool, A.; Lade, B.; Cole, A.; Broughton, J.; Newman, J.; Horvat, R.; Maybour, D.; Giles, D.; Davis, L.; Paton, R. A.; Loader, B.; Pennell, A.; Jaquiery, P.-D.; Brillant, S.; Selman, F.; Dumas, C.; Herrera, C.; Carraro, G.; Monaco, L.; Maury, A.; Peyrot, A.; Teng-Chuen-Yu, J.-P.; Richichi, A.; Irawati, P.; De Witt, C.; Schoenau, P.; Prager, R.; Colazo, C.; Melia, R.; Spagnotto, J.; Blain, A.; Alonso, S.; Román, A.; Santos-Sanz, P.; Rizos, J.-L.; Maestre, J.-L.; Dunham, D.

2017-10-01

Two narrow and dense rings (called C1R and C2R) were discovered around the Centaur object (10199) Chariklo during a stellar occultation observed on 2013 June 3. Following this discovery, we planned observations of several occultations by Chariklo’s system in order to better characterize the physical properties of the ring and main body. Here, we use 12 successful occulations by Chariklo observed between 2014 and 2016. They provide ring profiles (physical width, opacity, edge structure) and constraints on the radii and pole position. Our new observations are currently consistent with the circular ring solution and pole position, to within the ±3.3 km formal uncertainty for the ring radii derived by Braga-Ribas et al. The six resolved C1R profiles reveal significant width variations from ˜5 to 7.5 km. The width of the fainter ring C2R is less constrained, and may vary between 0.1 and 1 km. The inner and outer edges of C1R are consistent with infinitely sharp boundaries, with typical upper limits of one kilometer for the transition zone between the ring and empty space. No constraint on the sharpness of C2R’s edges is available. A 1σ upper limit of ˜20 m is derived for the equivalent width of narrow (physical width < 4 km) rings up to distances of 12,000 km, counted in the ring plane.

From coffee ring to spherulites ring of poly(ethylene oxide) film from drying droplet

NASA Astrophysics Data System (ADS)

Hu, Yinchun; Zhang, Xuerong; Qiu, Maibo; Wei, Yan; Zhou, Qiong; Huang, Di

2018-03-01

We discuss how the "spherulites ring" morphology and "coffee ring" profile of PEO film formed by the drying droplet at glass substrate with different heating rate. Upon increasing the heating rate of substrate, it is found that deposited PEO film from drying droplet shows the unusually observed "coffee ring" profile and "spherulites ring" morphology. The main mechanism for this phenomenon is proposed to be an enhanced Marangoni convection which is induced by the increased solute concentration gradient and reduced viscous force above 70 °C. A simple formation mechanism of the unusually observed "coffee ring" profile and "spherulites ring" morphology is proposed. These findings can be exploited to trace the center of Marangoni convection, with potential applications in designing the spherulite patterns of crystalline polymer films in ink-jet printing and self-assembly fields.

Nardò Ring, Italy

NASA Image and Video Library

2008-04-08

The Nardò Ring is a striking visual feature from space, and astronauts have photographed it several times. The Ring is a race car test track in Italy. This image was acquired by NASA Terra satellite on August 17. 2007.

Tritium, deuterium, and helium permeation through EPDM O-rings

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

Swansiger, W.A.

1992-03-01

This paper discusses tritium permeabilities determined at room temperature, 1.0 MPa (150 psia) tritium for three 23.4 cm diameter EPDM (ethylene-propylene-diene monomer) O-rings using a full-scale mock-up of the Al-SX shipping container seal geometry. The AL-SX container is being developed by Sandia National Laboratories for shipping tritium reservoirs. To determine the tritium permeation rate as a function of temperature, a 50.8 mm diameter EPDM O-ring was tested from room temperature to 150{degrees}C at a pressure of 1.0 MPa. Additional permeation measurements were made under the following test conditions: deuterium and helium-4 at room temperature and a pressure of 1.0 MPamore » using the full-scale AL-SX fixture, tritium from 0.1 MPa to 1.0 MPa at 142{degrees}C using the 50.8 mm fixture, and deuterium form room temperature to 150{degrees}C at a pressure of 1.0 MPa using the three full-scale O-rings showed the average room temperature, 1.0 MPa steady state tritium permeation rate to be about 1 {times} 10{sup {minus}2} Pa-liter/sec (7.6 {times} 10{sup {minus}5} torr-liter/sec or 1 {times} 10{sup {minus}4} std cc/sec), well within the allowable limit of 7.1 {times} 10{sup {minus}2} Pa-liter/sec for tritium release form the AL-SX container.« less

N-body simulations of viscous instability of planetary rings

NASA Astrophysics Data System (ADS)

Salo, Heikki; Schmidt, Jürgen

2010-04-01

We study viscous instability of planetary rings in terms of N-body simulations. We show that for rings composed of fairly elastic particles (e.g. as in Hatzes et al. [Hatzes, A., Bridges, F.G., Lin, D.N.C., 1988. Collisional properties of ice spheres at low impact velocities. Mon. Not. R. Astron. Soc. 231, 1091-1115]) the instability may lead to the spontaneous formation of dense ringlets in a background of lower density. In most parts of Saturn's rings the particle collisions are probably much more dissipative, as suggested by the presence of self-gravity wakes, and classic viscous instability should be suppressed. However, our results demonstrate that the mechanism of viscous instability itself is valid. The dynamical effects of size-dependent elasticity in a system with a size distribution have never been studied before. We show that this may in principle lead to a size-selective viscous instability, small particles concentrating on ringlets against the more uniform background of large particles.

Calcium sensitive ring-like oligomers formed by synaptotagmin

PubMed Central

Wang, Jing; Bello, Oscar; Auclair, Sarah M.; Wang, Jing; Coleman, Jeff; Pincet, Frederic; Krishnakumar, Shyam S.; Sindelar, Charles V.; Rothman, James E.

2014-01-01

The synaptic vesicle protein synaptotagmin-1 (SYT) is required to couple calcium influx to the membrane fusion machinery. However, the structural mechanism underlying this process is unclear. Here we report an unexpected circular arrangement (ring) of SYT’s cytosolic domain (C2AB) formed on lipid monolayers in the absence of free calcium ions as revealed by electron microscopy. Rings vary in diameter from 18–43 nm, corresponding to 11–26 molecules of SYT. Continuous stacking of the SYT rings occasionally converts both lipid monolayers and bilayers into protein-coated tubes. Helical reconstruction of the SYT tubes shows that one of the C2 domains (most likely C2B, based on its biochemical properties) interacts with the membrane and is involved in ring formation, and the other C2 domain points radially outward. SYT rings are disrupted rapidly by physiological concentrations of free calcium but not by magnesium. Assuming that calcium-free SYT rings are physiologically relevant, these results suggest a simple and novel mechanism by which SYT regulates neurotransmitter release: The ring acts as a spacer to prevent the completion of the soluble N-ethylmaleimide–sensitive factor activating protein receptor (SNARE) complex assembly, thereby clamping fusion in the absence of calcium. When the ring disassembles in the presence of calcium, fusion proceeds unimpeded. PMID:25201968

Vortex formation in magnetic narrow rings

NASA Astrophysics Data System (ADS)

Bland, J. A. C.

2002-03-01

between the contacts, the magnetization is everywhere parallel to the current, and the resistance is high. After the second switching into the reverse `onion' state a domain wall is now present between the contacts. This means some of the magnetization in the transverse domain wall is perpendicular to the current and hence the resistance decreases. This shows that one can clearly distinguish between the onion and vortex state using MR measurements. In addition, using the field dependent voltage drop between different contacts, the switching field at which each part of the ring reverses can be determined. >From the second type of measurements clear hysteretic behaviour is seen, indicating that there is some domain wall pinning. This demonstrates that the position of the domain walls can be identified by looking at the voltage drop between different contacts. By measuring at different magnitudes of the applied field the pinning strength of the domain walls is determined, and in particular the dependence of the domain wall pinning on the notch size. Furthermore the structure of the domain wall changes for different notch sizes, and hence the contribution of the wall to the resistance changes as well. Real-time measurements between different contacts might allow for domain wall speed measurements and other domain wall propagation studies. References: [1] J. Rothman, M. Kläui, L. Lopez-Diaz, C.A.F. Vaz, A. Bleloch, J.A.C. Bland, Z. Cui, R. Speaks, Phys. Rev. Lett. 86 (2001) 1098. [2] Z. Cui, J. Rothman, M. Kläui, L. Lopez-Diaz, C.A.F. Vaz, J.A.C. Bland, to be published. [3] M. Kläui, L. Lopez-Diaz, J. Rothman, C.A.F. Vaz, J.A.C. Bland, Z. Cui, J. Magn. Magn. Mat., to be published. [4] L. Lopez-Diaz, J. Rothman, M. Kläui, J.A.C. Bland, IEEE Trans. Mag. 36 (2000) 3155. [5] C.A.F. Vaz, L. Lopez-Diaz, M. Kläui, J.A.C. Bland, T.L. Monchesky, J. Unguris, Z. Cui, 46th MMM Conference, Seattle, 2001. [6] R. D. McMichael and M. J. Donahue, IEEE Trans. Mag. 33, 4167-4169 (1997).

Drought frequency in central California since 101 B.C. recordered in giant sequoia tree rings

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

Hughes, M.K.; Brown, P.M.

1992-01-01

Well replicated tree-ring width index chronologies have been developed for giant sequoia at three sites in the Sierra Nevada, California. Extreme low-growth events in these chronologies correspond with regional drought events in the twentieth century in the San Joaquin drainage, in which the giant sequoia sites are located. This relationship is based upon comparison of tree-ring indices with August Palmer Drought Severity Indices for California Climate Division 5. Ring-width indices in the lowest decile from each site were compared. The frequency of low-growth events which occurred at all three sites in the same year is reconstructed from 101 B.C. tomore » A.D. 1988. The inferred frequency of severe drought events changes through time, sometimes suddenly. The period from roughly 1850 to 1950 had one of the lowest frequencies of drought of any one hundred year period in the 2089 year record. The twentieth century so far has had a below-average frequency of extreme droughts. 26 refs., 6 figs., 1 tab.« less

Vegetation control effects on untreated wood, crude cellulose and holocellulose 𗉝C of early and latewood in 3- to 5-year-old rings of Douglas-fir

Treesearch

Adrian Ares; Constance A Harrington; Thomas A. Terry; Joseph M. Kraft

2009-01-01

The stable carbon (C) composition of tree rings expressed as 13C, is a measure of intrinsic water-use efficiency and can indicate the occurrence of past water shortages for tree growth. We examined 13C in 3- to 5-year-old rings of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees...

Uranus rings and two moons

NASA Technical Reports Server (NTRS)

1986-01-01

Voyager 2 has discovered two 'shepherd' satellites associated with the rings of Uranus. The two moons -- designated 1986U7 and 1986U8 -- are seen here on either side of the bright epsilon ring; all nine of the known Uranian rings are visible. The image was taken Jan. 21, 1986, at a distance of 4.1 million kilometers (2.5 million miles) and resolution of about 36 km (22 mi). The image was processed to enhance narrow features. The epsilon ring appears surrounded by a dark halo as a result of this processing; occasional blips seen on the ring are also artifacts. Lying inward from the epsilon ring are the delta, gamma and eta rings; then the beta and alpha rings; and finally the barely visible 4, 5 and 6 rings. The rings have been studied since their discovery in 1977, through observations of how they diminish the light of stars they pass in front of. This image is the first direct observation of all nine rings in reflected sunlight. They range in width from about 100 km (60 mi) at the widest part of the epsilon ring to only a few kilometers for most of the others. The discovery of the two ring moons 1986U7 and 1986U8 is a major advance in our understanding of the structure of the Uranian rings and is in good agreement with theoretical predictions of how these narrow rings are kept from spreading out. Based on likely surface brightness properties, the moons are of roughly 2O- and 3O-km diameter, respectively. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

Comparison of different mass spectrometry techniques in the measurement of L-[ring-13C6]phenylalanine incorporation into mixed muscle proteins

PubMed Central

Zabielski, Piotr; Ford, G. Charles; Persson, X. Mai; Jaleel, Abdul; Dewey, Jerry D.; Nair, K Sreekumaran

2013-01-01

Precise measurement of low enrichment of stable isotope labeled amino-acid tracers in tissue samples is a prerequisite in measuring tissue protein synthesis rates. The challenge of this analysis is augmented when small sample size is a critical factor. Muscle samples from human participants following an 8 hour intravenous infusion of L-[ring-13C6]phenylalanine and a bolus dose of L-[ring-13C6]phenylalanine in a mouse were utilized. Liquid Chromatography tandem mass spectrometry (LC/MS/MS), Gas Chromatography tandem mass spectrometry (GC/MS/MS) and Gas Chromatography/Mass spectrometry (GC/MS) were compared to the Gas Chromatography-Combustion-Isotope Ratio mass spectrometry (GC/C/IRMS), to measure mixed muscle protein enrichment of [ring13C6]phenylalanine enrichment. The sample isotope enrichment ranged from 0.0091 to 0.1312 Molar Percent excess (MPE). As compared with GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS showed coefficients of determination of R2 = 0.9962 and R2 = 0.9942, and 0.9217 respectively. However, the precision of measurements (coefficients of variation) for intra-assay are 13.0%, 1.7%, 6.3% and 13.5% and for inter-assay are 9.2%, 3.2%, 10.2% and 25% for GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS respectively. The muscle sample sizes required to obtain these results were 8μg, 0.8μg, 3μg and 3μg for GC/C/IRMS, LC/MS/MS, GC/MS/MS, and GC/MS respectively. We conclude that LC/MS/MS is optimally suited for precise measurements of L-[ring-13C6]phenylalanine tracer enrichment in low abundance and in small quantity samples. PMID:23378099

Mechanics of coupling proton movements to c-ring rotation in ATP synthase.

PubMed

Fillingame, Robert H; Angevine, Christine M; Dmitriev, Oleg Y

2003-11-27

F1F0 ATP synthases generate ATP by a rotary catalytic mechanism in which H+ transport is coupled to rotation of an oligomeric ring of c subunits extending through the membrane. Protons bind to and then are released from the aspartyl-61 residue of subunit c at the center of the membrane. Subunit a of the F0 sector is thought to provide proton access channels to and from aspartyl-61. Here, we summarize new information on the structural organization of Escherichia coli subunit a and the mapping of aqueous-accessible residues in the second, fourth and fifth transmembrane helices (TMHs). Aqueous-accessible regions of these helices extend to both the cytoplasmic and periplasmic surface. We propose that aTMH4 rotates to alternately expose the periplasmic or cytoplasmic half-channels to aspartyl-61 of subunit c during the proton transport cycle. The concerted rotation of interacting helices in subunit a and subunit c is proposed to be the mechanical force driving rotation of the c-rotor, using a mechanism akin to meshed gears.

Integrated interpretation of geophysical data of the Paleozoic structure in the northwestern part of the Siljan Ring impact crater, central Sweden

NASA Astrophysics Data System (ADS)

Muhamad, Harbe; Juhlin, Christopher; Malehmir, Alireza; Sopher, Daniel

2018-01-01

The Siljan Ring impact structure is the largest known impact structure in Europe and is Late Devonian in age. It contains a central uplift that is about 20-30 km in diameter and is surrounded by a ring-shaped depression. The Siljan area is one of the few areas in Sweden where the Paleozoic sequence has not been completely eroded, making it an important location for investigation of the geological and tectonic history of Baltica during the Paleozoic. The Paleozoic strata in this area also provide insight into the complex deformation processes associated with the impact. In this study we focus on the northwestern part of the Siljan Ring, close to the town of Orsa, with the main objective of characterizing the subsurface Paleozoic succession and uppermost Precambrian crystalline rocks along a series of seismic reflection profiles, some of which have not previously been published. We combine these seismic data with gravity and magnetic data and seismic traveltime tomography results to produce an integrated interpretation of the subsurface in the area. Our interpretation shows that the Paleozoic sequence in this area is of a relatively constant thickness, with a total thickness typically between 300 and 500 m. Faulting appears to be predominantly extensional, which we interpret to have occurred during the modification stage of the impact. Furthermore, based on the geophysical data in this area, we interpret that the impact related deformation to differ in magnitude and style from other parts of the Siljan Ring.

Stable forming conditions and geometrical expansion of L-shape rings in ring rolling process

NASA Astrophysics Data System (ADS)

Quagliato, Luca; Berti, Guido A.; Kim, Dongwook; Kim, Naksoo

2018-05-01

Based on previous research results concerning the radial-axial ring rolling process of flat rings, this paper details an innovative approach for the determination of the stable forming conditions to successfully simulate the radial ring rolling process of L-shape profiled rings. In addition to that, an analytical model for the estimation of the geometrical expansion of L-shape rings from its initial flat ring preform is proposed and validated by comparing its results with those of numerical simulations. By utilizing the proposed approach, steady forming conditions could be achieved, granting a uniform expansion of the ring throughout the process for all of the six tested cases of rings having the final outer diameter of the flange ranging from 545mm and 1440mm. The validation of the proposed approach allowed concluding that the geometrical expansion of the ring, as estimated by the proposed analytical model, is in good agreement with the results of the numerical simulation, with a maximum error of 2.18%, in the estimation of the ring wall diameter, 1.42% of the ring flange diameter and 1.87% for the estimation of the inner diameter of the ring, respectively.

Minimal size of coffee ring structure.

PubMed

Shen, Xiaoying; Ho, Chih-Ming; Wong, Tak-Sing

2010-04-29

A macroscopic evaporating water droplet with suspended particles on a solid surface will form a ring-like structure at the pinned contact line due to induced capillary flow. As the droplet size shrinks, the competition between the time scales of the liquid evaporation and the particle movement may influence the resulting ring formation. When the liquid evaporates much faster than the particle movement, coffee ring formation may cease. Here, we experimentally show that there exists a lower limit of droplet size, D(c), for the successful formation of a coffee ring structure. When the particle concentration is above a threshold value, D(c) can be estimated by considering the collective effects of the liquid evaporation and the particle diffusive motion within the droplet. For suspended particles of size approximately 100 nm, the minimum diameter of the coffee ring structure is found to be approximately 10 microm.

Design and Optimization of Composite Gyroscope Momentum Wheel Rings

NASA Technical Reports Server (NTRS)

Bednarcyk, Brett A.; Arnold, Steven M.

2007-01-01

Stress analysis and preliminary design/optimization procedures are presented for gyroscope momentum wheel rings composed of metallic, metal matrix composite, and polymer matrix composite materials. The design of these components involves simultaneously minimizing both true part volume and mass, while maximizing angular momentum. The stress analysis results are combined with an anisotropic failure criterion to formulate a new sizing procedure that provides considerable insight into the design of gyroscope momentum wheel ring components. Results compare the performance of two optimized metallic designs, an optimized SiC/Ti composite design, and an optimized graphite/epoxy composite design. The graphite/epoxy design appears to be far superior to the competitors considered unless a much greater premium is placed on volume efficiency compared to mass efficiency.

In vitro eye irritation testing using the open source reconstructed hemicornea - a ring trial.

PubMed

Mewes, Karsten R; Engelke, Maria; Zorn-Kruppa, Michaela; Bartok, Melinda; Tandon, Rashmi; Brandner, Johanna M; Petersohn, Dirk

2017-01-01

The aim of the present ring trial was to test whether two new methodological approaches for the in vitro classification of eye irritating chemicals can be reliably transferred from the developers' laboratories to other sites. Both test methods are based on the well-established open source reconstructed 3D hemicornea models. In the first approach, the initial depth of injury after chemical treatment in the hemicornea model is derived from the quantitative analysis of histological sections. In the second approach, tissue viability, as a measure for corneal damage after chemical treatment, is analyzed separately for epithelium and stroma of the hemicornea model. The three independent laboratories that participated in the ring trial produced their own hemicornea models according to the test producer's instructions, thus supporting the open source concept. A total of 9 chemicals with different physicochemical and eye-irritating properties were tested to assess the between-laboratory reproducibility (BLR), the predictive performance, as well as possible limitations of the test systems. The BLR was 62.5% for the first and 100% for the second method. Both methods enabled to discriminate Cat. 1 chemicals from all non-Cat. 1 substances, which qualifies them to be used in a top-down approach. However, the selectivity between No Cat. and Cat. 2 chemicals still needs optimization.

Design of a finger ring extremity dosemeter based on OSL readout of alpha-Al2O3:C.

PubMed

Durham, J S; Zhang, X; Payne, F; Akselrod, M S

2002-01-01

A finger-ring dosemeter and reader has been designed that uses OSL readout of alpha-Al2O3:C (aluminium oxide). The use of aluminium oxide is important because it allows the sensitive element of the dosemeter to be a very thin layer that reduces the beta and gamma energy dependence to acceptable levels without compromising the required sensitivity for dose measurement. OSL readout allows the ring dosemeter to be interrogated with minimal disassembly. The ring dosemeter consists of three components: aluminium oxide powder for measurement of dose, an aluminium substrate that gives structure to the ring, and an aluminised Mylar cover to prevent the aluminium oxide from exposure to light. The thicknesses of the three components have been optimised for beta response using the Monte Carlo computer code FLUKA. A reader was also designed and developed that allows the dosemeter to be read after removing the Mylar. Future efforts are discussed.

40 CFR Table C-4 to Subpart C of... - Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM...

40 CFR Table C-4 to Subpart C of... - Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM...

Relation of Nickel Concentrations in Tree Rings to Groundwater Contamination

NASA Astrophysics Data System (ADS)

Yanosky, Thomas M.; Vroblesky, Don A.

1992-08-01

Increment cores were collected from trees growing at two sites where groundwater is contaminated by nickel. Proton-induced X ray emission spectroscopy was used to determine the nickel concentrations in selected individual rings and in parts of individual rings. Ring nickel concentrations were interpreted on the basis of recent concentrations of nickel in aquifers, historical information about site use activities, and model simulations of groundwater flow. Nickel concentrations in rings increased during years of site use but not in trees outside the contaminated aquifers. Consequently, it was concluded that trees may preserve in their rings an annual record of nickel contamination in groundwater. Tulip trees and oaks contained higher concentrations of nickel than did sassafras, sweet gum, or black cherry. No evidence was found that nickel accumulates consistently within parts of individual rings or that nickel is translocated across ring boundaries.

Relation of nickel concentrations in tree rings to groundwater contamination

USGS Publications Warehouse

Yanosky, Thomas M.; Vroblesky, Don A.

1992-01-01

Increment cores were collected from trees growing at two sites where groundwater is contaminated by nickel. Proton-induced X ray emission spectroscopy was used to determine the nickel concentrations in selected individual rings and in parts of individual rings. Ring nickel concentrations were interpreted on the basis of recent concentrations of nickel in aquifers, historical information about site use activities, and model simulations of groundwater flow. Nickel concentrations in rings increased during years of site use but not in trees outside the contaminated aquifers. Consequently, it was concluded that trees may preserve in their rings an annual record of nickel contamination in groundwater. Tulip trees and oaks contained higher concentrations of nickel than did sassafras, sweet gum, or black cherry. No evidence was found that nickel accumulates consistently within parts of individual rings or that nickel is translocated across ring boundaries.

40 CFR Appendix C to Subpart S of... - Steady-State Short Test Standards

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Steady-State Short Test Standards C Appendix C to Subpart S of Part 51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED.../Maintenance Program Requirements Pt. 51, Subpt. S, App. C Appendix C to Subpart S of Part 51—Steady-State...

40 CFR Appendix C to Subpart S of... - Steady-State Short Test Standards

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Steady-State Short Test Standards C Appendix C to Subpart S of Part 51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED.../Maintenance Program Requirements Pt. 51, Subpt. S, App. C Appendix C to Subpart S of Part 51—Steady-State...

40 CFR Appendix C to Subpart S of... - Steady-State Short Test Standards

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Steady-State Short Test Standards C Appendix C to Subpart S of Part 51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED.../Maintenance Program Requirements Pt. 51, Subpt. S, App. C Appendix C to Subpart S of Part 51—Steady-State...

Stacked Corrugated Horn Rings

NASA Technical Reports Server (NTRS)

Sosnowski, John B.

2010-01-01

This Brief describes a method of machining and assembly when the depth of corrugations far exceeds the width and conventional machining is not practical. The horn is divided into easily machined, individual rings with shoulders to control the depth. In this specific instance, each of the corrugations is identical in profile, and only differs in diameter and outer profile. The horn is segmented into rings that are cut with an interference fit (zero clearance with all machining errors biased toward contact). The interference faces can be cut with a reverse taper to increase the holding strength of the joint. The taper is a compromise between the interference fit and the clearance of the two faces during assembly. Each internal ring is dipped in liquid nitrogen, then nested in the previous, larger ring. The ring is rotated in the nest until the temperature of the two parts equalizes and the pieces lock together. The resulting assay is stable, strong, and has an internal finish that cannot be achieved through other methods.

Clumps in the F Ring

NASA Image and Video Library

2004-03-12

Scientists have only a rough idea of the lifetime of clumps in Saturn's rings - a mystery that Cassini may help answer. The latest images taken by the Cassini-Huygens spacecraft show clumps seemingly embedded within Saturn's narrow, outermost F ring. The narrow angle camera took the images on Feb. 23, 2004, from a distance of 62.9 million kilometers (39 million miles). The two images taken nearly two hours apart show these clumps as they revolve about the planet. The small dot at center right in the second image is one of Saturn's small moons, Janus, which is 181 kilometers, (112 miles) across. Like all particles in Saturn's ring system, these clump features orbit the planet in the same direction in which the planet rotates. This direction is clockwise as seen from Cassini's southern vantage point below the ring plane. Two clumps in particular, one of them extended, is visible in the upper part of the F ring in the image on the left, and in the lower part of the ring in the image on the right. Other knot-like irregularities in the ring's brightness are visible in the image on the right. The core of the F ring is about 50 kilometers (31miles) wide, and from Cassini's current distance, is not fully visible. The imaging team enhanced the contrast of the images and magnified them to aid visibility of the F ring and the clump features. The camera took the images with the green filter, which is centered at 568 nanometers. The image scale is 377 kilometers (234 miles) per pixel. NASA's two Voyager spacecraft that flew past Saturn in 1980 and 1981 were the first to see these clumps. The Voyager data suggest that the clumps change very little and can be tracked as they orbit for 30 days or more. No clump survived from the time of the first Voyager flyby to the Voyager 2 flyby nine months later. Scientists are not certain of the cause of these features. Among the theories proposed are meteoroid bombardments and inter-particle collisions in the F ring. http

Application of C/C composites to the combustion chamber of rocket engines. Part 1: Heating tests of C/C composites with high temperature combustion gases

NASA Astrophysics Data System (ADS)

Tadano, Makoto; Sato, Masahiro; Kuroda, Yukio; Kusaka, Kazuo; Ueda, Shuichi; Suemitsu, Takeshi; Hasegawa, Satoshi; Kude, Yukinori

1995-04-01

Carbon fiber reinforced carbon composite (C/C composite) has various superior properties, such as high specific strength, specific modulus, and fracture strength at high temperatures of more than 1800 K. Therefore, C/C composite is expected to be useful for many structural applications, such as combustion chambers of rocket engines and nose-cones of space-planes, but C/C composite lacks oxidation resistivity in high temperature environments. To meet the lifespan requirement for thermal barrier coatings, a ceramic coating has been employed in the hot-gas side wall. However, the main drawback to the use of C/C composite is the tendency for delamination to occur between the coating layer on the hot-gas side and the base materials on the cooling side during repeated thermal heating loads. To improve the thermal properties of the thermal barrier coating, five different types of 30-mm diameter C/C composite specimens constructed with functionally gradient materials (FGM's) and a modified matrix coating layer were fabricated. In this test, these specimens were exposed to the combustion gases of the rocket engine using nitrogen tetroxide (NTO) / monomethyl hydrazine (MMH) to evaluate the properties of thermal and erosive resistance on the thermal barrier coating after the heating test. It was observed that modified matrix and coating with FGM's are effective in improving the thermal properties of C/C composite.

High-Precision Measurement of 13C/12C Isotopic Ratio Using Gas Chromatography-Combustion-Cavity Ring-Down Spectroscopy

NASA Astrophysics Data System (ADS)

Saad, N.; Kuramoto, D. S.; Haase, C.; Crosson, E.; Tan, S.; Zare, R. N.

2009-12-01

Light stable isotope analysis, and in particular, compound specific isotopic analysis (CSIA), is a valuable tool to elucidate pathways and provide a better insight into biological, ecological, and geological systems. We present here the results of compound-specific isotopic carbon analysis of short chain hydrocarbons using the world’s first combination of gas chromatography, combustion interface, and cavity ring-down spectroscopy (GC-C-CRDS). Cavity ring-down spectroscopy (CRDS) is a highly sensitive optical spectroscopy, one application of which is to measure the stable isotopic ratios in small molecules. Because it uses a highly reflective optical cavity with many kilometers effective path length, CRDS provides some of the most sensitive and precise optical absorption measurements. Most optical spectroscopy isotopic analysis measures the quantities of each isotopologue independently using their distinct ro-vibrational spectra. The most common isotopes measured with optical spectroscopy are 13C and 12C in carbon dioxide. However, the isotopes of hydrogen, oxygen, and sulfur have also been measured. Unlike isotope ratio mass spectrometry (IRMS), optical spectroscopy can distinguish among isobars, which have essentially identical m/z ratios. The combination of chemical separation, chemical conversion, and CRDS makes a nearly universal tool for isotopic analysis of mixtures. In addition, CRDS can tolerate a variety of compounds mixed with the target. For example, CRDS can measure carbon dioxide and its isotopic 13C/12C ratio in the presence of oxygen. Using the novel GC-C-CRDS system, we injected a 75-microliter mixture of approximately equal quantities of methane, ethane, and propane into a gas chromatograph using helium as carrier gas. The methane, ethane, and propane were separated in time by 100 to 200 seconds after the chromatograph. Oxygen gas was added, and the hydrocarbons were combusted in a catalytic combustor with platinum and nickel, held at 1150oC. The

Propellers in Saturn's rings

NASA Astrophysics Data System (ADS)

Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

2013-12-01

Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~<500m in size) have been indirectly identified in Saturn's A ring through their propeller signature in the images. Furthermore, recent Cassini observations indicate the possible existence of objects embedded even in Saturn's B and C ring. In this paper we present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B

Quality Assurance Project Plan for Verification of Sediment Ecotoxicity Assessment Ring(SEA Ring)

EPA Science Inventory

The objective of the verification is to test the efficacy and ability of the Sediment Ecotoxicity Assessment Ring (SEA Ring) to evaluate the toxicity of contaminants in the sediment, at the sediment-water interface, and WC to organisms that live in those respective environments.

40 CFR Table C-4 to Subpart C of... - Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM10, PM2.5 and...

40 CFR Table C-4 to Subpart C of... - Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM10, PM2.5 and...

40 CFR Table C-4 to Subpart C of... - Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM10, PM2.5 and...

Non-destructive testing of satellite nozzles made of carbon fibre ceramic matrix composite, C/SiC

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

Rebelo Kornmeier, J.; Hofmann, M.; Schmidt, S.

Carbon fibre ceramic matrix composite materials, C/SiC, are excellent candidates as lightweight structural materials for high performance hot structures such as in aerospace applications. Satellite nozzles are manufactured from C/SiC, using, for instance, the Liquid Polymer Infiltration (LPI) process. In this article the applicability of different non-destructive analysis methods for the characterisation of C/SiC components will be discussed. By using synchrotron and neutron tomography it is possible to characterise the C/SiC material in each desired location or orientation. Synchrotron radiation using tomography on small samples with a resolution of 1.4 {mu}m, i.e. the fibre scale, was used to characterise threemore » dimensionally fibre orientation and integrity, matrix homogeneity and dimensions and distributions of micro pores. Neutron radiation tomography with a resolution of about 300 {mu}m was used to analyse the over-all C/SiC satellite nozzle component with respect to the fibre content. The special solder connection of a C/SiC satellite nozzle to a metallic ring was also successfully analysed by neutron tomography. In addition, the residual stress state of a temperature tested satellite nozzle was analysed non-destructively in depth by neutron diffraction. The results revealed almost zero stress for the principal directions, radial, axial and tangential, which can be considered to be the principal directions.« less

Mechanical evaluation of aluminum alloy ring fixator.

PubMed

Tosborvorn, Somboon; Cheechareon, Sukrom; Ruttanuchun, Kittiput; Sirivedin, Suparerk; Rhienumporn, Chaitawat

2006-11-01

To test the homemade ring fixator as a tool for correction of bony deformity. The authors developed an aluminum alloy ring fixator and tested it to find out the accuracy of manufacturing and strength of the ring systems under axial load with the Roundness Testing Machine and Lloyd Universal Testing Machine. The mean diameter of the twenty five-drill holes was 6.5843872 +/- 0.0521594 mm (mean +/- SD). Distance between particular drill holes, which reflected the precision of drilling, had a high accuracy with standard deviation from 0.1138 to 0.1870 mm. The roundness of the rings was 0.2421376 +/- 0.12437977 mm (mean +/- SD). The system structure had minimal permanent deformity at breaking point, mean yield strength of the system was 4786.9 +/- 14.353 N (mean +/- SD). This was caused by the failure of the wire. Mean stiffness of the system was 127 N./mm. The aluminum alloy ring fixator was strong enough and well tolerated for clinical usage

Reconciling Eddy Flux and Tree Ring Estimates of Forest Water-Use Efficiency

NASA Astrophysics Data System (ADS)

Wehr, R. A.; Belmecheri, S.; Commane, R.; Munger, J. W.; Wofsy, S. C.; Saleska, S. R.

2016-12-01

Eddy flux measurements of ecosystem-atmosphere CO2 and water vapor exchange suggest that rising atmospheric CO2 levels have caused plant endogenous water-use efficiency (WUE) to increase strongly over the last 20 years at sites including the Harvard Forest.1 On the other hand, tree ring 13C isotope measurements at the Harvard Forest seem to suggest that endogenous WUE has not increased.2 Several potential reasons for this discrepancy have been proposed,2,3 including: (1) the definitional difference between the "inherent WUE" calculated from eddy fluxes and the "intrinsic WUE" calculated from tree rings, (2) neglect of factors that affect the isotopic composition of tree ring carbon (e.g. mesophyll conductance, photorespiration, post-photosynthetic fractionation), and (3) temporal mismatch between the instantaneous CO2 flux and seasonally-integrated tree ring carbon. Here we test those proposed explanations by combining tree-ring 13C measurements, 13CO2 eddy flux measurements, and recently developed estimates of transpiration, photosynthesis, and canopy stomatal conductance. We first compute both inherent and intrinsic WUE from eddy flux data and show that their definitional difference does not explain the discrepancy between eddy flux and tree ring estimates of WUE. We further investigate the impact of mesophyll conductance, photorespiration, and mitochondrial respiration on the seasonal isotopic composition of assimilated carbon to elucidate the mismatch between eddy flux- and tree ring-derived water use efficiencies. 1. Keenan, T. F. et al. Increase in forest water-use efficiency as atmospheric carbon dioxide concentrations rise. Nature 499, 324-327 (2013). 2. Belmecheri, S. et al. Tree-ring δ13C tracks flux tower ecosystem productivity estimates in a NE temperate forest. Environ. Res. Lett. 9, 074011 (2014). 3. Seibt, U. et al. Carbon isotopes and water use efficiency: sense and sensitivity. Oecologia 155, 441-454 (2008).

Low thermal expansion seal ring support

DOEpatents

Dewis, David W.; Glezer, Boris

2000-01-01

Today, the trend is to increase the temperature of operation of gas turbine engines. To cool the components with compressor discharge air, robs air which could otherwise be used for combustion and creates a less efficient gas turbine engine. The present low thermal expansion sealing ring support system reduces the quantity of cooling air required while maintaining life and longevity of the components. Additionally, the low thermal expansion sealing ring reduces the clearance "C","C'" demanded between the interface between the sealing surface and the tip of the plurality of turbine blades. The sealing ring is supported by a plurality of support members in a manner in which the sealing ring and the plurality of support members independently expand and contract relative to each other and to other gas turbine engine components.

Alterations of rings B and C of colchicine are cumulative in overall binding to tubulin but modify each kinetic step.

PubMed

Dumortier, C; Gorbunoff, M J; Andreu, J M; Engelborghs, Y

1996-12-10

The role of the elimination of ring B and/or the modification of ring C of colchicine in tubulin binding kinetics and thermodynamics has been characterized, using four different molecules. These ligands are colchicine (COL); 2-methoxy-5-(2',3',4'-trimethoxyphenyl)-2,4,6-cycloheptatrien-1-on e (MTC), in which the central ring B has been reduced to one bond; allocolchicine (ALLO), in which ring C has been replaced by a six-membered ring; and 2,3,4-trimethoxy-4'-carbomethoxy-1,1'-biphenyl (TCB), where the same two modifications are made simultaneously. This paper describes the kinetics of association of ALLO with tubulin. The binding is accompanied by a fluorescence increase with slow biphasic kinetics, indicating binding to fast and slow tubulin isotypes. Binding to each of these isotypes occurs in two steps: a fast initial binding followed by a slower isomerization step. The K1 and k2 values for ALLO at 25 degrees C are 14,000 +/- 2,000 and 25,000 +/- 6,000 M-1 (fast and slow isotypes) and 0.055 +/- 0.003 s-1 and 0.013 +/- 0.001 s-1 (fast and slow isotype), respectively. For ALLO the reaction standard enthalpy change of the initial binding is 68 +/- 5 kJ.mol-1 (fast isotype) and 45 +/- 33 kJ.mol-1 (slow isotype) and the activation energy for the second forward step is 58 +/- 14 kJ.mol-1 (fast isotype) and 81 +/- 17 kJ.mol-1 (slow isotype). Displacement kinetics of bound ALLO by podophyllotoxin was monoexponential. The activation energy for the isomerization in the off direction is 107 +/- 7 kJ.mol-1. Comparison of the thermodynamic parameters for all four compounds shows that the modifications of both rings are cumulative with respect to overall binding. For the intermediate state there is a mutual influence of both modifications, suggesting an alteration of the reaction pathway.

First Evidence of Jupiter Ring

NASA Technical Reports Server (NTRS)

1979-01-01

First evidence of a ring around the planet Jupiter is seen in this photograph taken by Voyager 1 on March 4, 1979. The multiple exposure of the extremely thin faint ring appears as a broad light band crossing the center of the picture. The edge of the ring is 1,212,000 km from the spacecraft and 57,000 km from the visible cloud deck of Jupiter. The background stars look like broken hair pins because of spacecraft motion during the 11 minute 12 second exposure. The wavy motion of the star trails is due to the ultra-slow natural oscillation of the spacecraft (with a period of 78 seconds). The black dots are geometric calibration points in the camera. The ring thickness is estimated to be 30 km or less. The photograph was part of a sequence planned to search for such rings in Jupiter's equatorial plane. The ring has been invisible from Earth because of its thinness and its transparency when viewed at any angle except straight on. JPL manages and controls the Voyager Project for NASA's Office of Space Science.

The chemistry of (ring)Ru sup 2+ (ring = tetramethylthiophene, p-cymene)

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

Ganja, E.A.; Rauchfuss, T.B.; Stern, C.L.

1991-01-01

Described are the compounds ((ring)Ru(OTf){sub 2}){sub x}, where ring = 2,3,4,5-tetramethylthiophene (TMT, 1), and p-cymene (2). These electrophilic reagents serve as precursors to ((ring)RuL{sub 3}){sup 2+}, where L{sub 3} = (H{sub 2}O){sub 3}, (NH{sub 3}){sub 3}, and (PH{sub 3}){sub 3}. Solutions of 1 and 2 react with carbon monoxide to give (ring)Ru(CO)(OTf){sub 2}. The addition of thiophenes to CH{sub 2}Cl{sub 2} solutions of 1 or 2 leads to the precipitation of the sandwich compounds ((ring)(SC{sub 4}R{sub 4})Ru)(OTf){sub 2}, where SC{sub 4}R{sub 4} = thiophene, 2,5-dimethylthiophene, and TMT. ((TMT)Ru(H{sub 2}O){sub 3})(OTf){sub 2} was characterized by single-crystal X-ray crystallography, which established amore » piano-stool geometry with a planar TMT ligand. ((TMT)Ru(D{sub 2}O){sub 3})(OTf){sub 2} decomposes in D{sub 2}O solution at 150C to give ((TMT){sub 2}Ru){sup 2+}, which undergoes selective deuteration at the 2,5-methyl groups. D{sub 2}O solutions of ((TMT){sub 2}Ru){sup 2+} undergo photochemical loss of one TMT ligand in water to give ((TMT)Ru(H{sub 2}O){sub 3}){sup 2+}. A procedure is described for the reversible loading of 1 onto {gamma}-alumina, which in turn was characterized by {sup 13}C CP-MAS NMR spectroscopy.« less

The Saturn Ring Observer: In situ studies of planetary rings

NASA Astrophysics Data System (ADS)

Nicholson, P. D.; Tiscareno, M. S.; Spilker, L. J.

2010-12-01

As part of the Planetary Science Decadal Survey recently undertaken by the NRC's Space Studies Board for the National Academy of Sciences, studies were commissioned for a number of potential missions to outer planet targets. One of these studies examined the technological feasibility of a mission to carry out in situ studies of Saturn's rings, from a spacecraft placed in a circular orbit above the ring plane: the Saturn Ring Observer. The technical findings and background are discussed in a companion poster by T. R. Spilker et al. Here we outline the science goals of such a mission. Most of the fundamental interactions in planetary rings occur on spatial scales that are unresolved by flyby or orbiter spacecraft. Typical particle sizes in the rings of Saturn are in the 1 cm - 10 m range, and average interparticle spacings are a few meters. Indirect evidence indicates that the vertical thickness of the rings is as little as 5 - 10 m, which implies a velocity dispersion of only a few mm/sec. Theories of ring structure and evolution depend on the unknown characteristics of interparticle collisions and on the size distribution of the ring particles. The SRO could provide direct measurements of both the coefficient of restitution -- by monitoring individual collisions -- and the particles’ velocity dispersion. High-resolution observations of individual ring particles should also permit estimates of their spin states. Numerical simulations of Saturn’s rings incorporating both collisions and self-gravity predict that the ring particles are not uniformly distributed, but are instead clustered into elongated structures referred to as “self-gravity wakes”, which are continually created and destroyed on an orbital timescale. Theory indicates that the average separation between wakes in the A ring is of order 30-100 m. Direct imaging of self-gravity wakes, including their formation and subsequent dissolution, would provide critical validation of these models. Other

40 CFR Appendix C to Part 66 - Computer Program

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Computer Program C Appendix C to Part...) ASSESSMENT AND COLLECTION OF NONCOMPLIANCE PENALTIES BY EPA Pt. 66, App. C Appendix C to Part 66—Computer Program Note: For text of appendix C see appendix C to part 67. ...

Comparison of ring-focus image profile with predictions for the AXAF VETA-I test

NASA Technical Reports Server (NTRS)

Zissa, David E.

1993-01-01

The X-ray test of the largest pair of nearly cylindrical mirrors for the Advanced X-ray Astrophysics Facility (AXAF) was completed in October 1991 at Marshall Space Flight Center. The test assembly was named the Verification Engineering Test Article I (VETA-I). The ring-focus portion of the test measured the imaging quality of azimuthal sections of VETA-I. This gives information about the core of the on-orbit image. The finite source distance, VETA-I mirror spacing, and VETA-I structural deformation caused the core of the image to be spread over a diameter of nearly 4 arc seconds at the VETA-I overall focus. The results of a preliminary analysis of the ring-focus data and the implications for the on-orbit image of the telescope are discussed. An upper limit for the on-orbit encircled-energy fraction at 1 arc second diameter was determined to be 0.82 at 0.277 keV X-ray energy. This assumes that the bottoms of the mirrors in the VETA-I arrangement are representative of the mirror surfaces and that the on-orbit system would be aligned using a combination of preliminary measurements and predictions for the mirror surface shapes.

49 CFR Appendix C- to Part 544... - Appendix C- to Part 544 Motor Vehicle Rental and Leasing Companies (Including Licensees and...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Appendix C- to Part 544 Motor Vehicle Rental and Leasing Companies (Including Licensees and Franchisees) Subject to the Reporting Requirements of Part 544 C Appendix C- to Part 544 Motor Vehicle Rental and Leasing Companies (Including Licensees and...

Findings on rings and inner satellites of Saturn of Pioneer 11

NASA Astrophysics Data System (ADS)

van Allen, J. A.

1982-09-01

The introductory part of this paper gives a short account of the theory of absorption by planetary rings and satellites of energetic charged particles that are trapped in a planet's magnetic field and describes the observable consequences of such absorption processes. The previously published University of Iowa observations of absorption features during Pioneer 11's passage through Saturn's inner radiation belt on 1 September 1979 are critically reanalyzed and related to other evidence on rings and satellites inside 2.9 Saturn radii, especially that from the imaging system on Voyagers 1 and 2. It is found (a) that satellites 1979 S1, 1979 S2, and 1980 S3 are almost certainly identical; (b) that the evidence for 1979 S4 is weak to nonexistent; (c) that 1979 S5 and two other nearby absorption features and 1979 S6 and one other nearby absorption feature are probably caused by longitudinal and radial structure of Ring F and not by satellites; and (d) that absorption feature 1979 S3 at 169,200 + or - 600 km is identified with the optically observed Ring G.

The Crossings of Saturn Ring Plane by the Earth in 1995: Ring Thickness

NASA Astrophysics Data System (ADS)

Poulet, François; Sicardy, Bruno; Dumas, Christophe; Jorda, Laurent; Tiphène, Didier

2000-05-01

The crossings of Saturn's ring plane by Earth were observed in the near infrared on May 22 and August 10, 1995, from the 2.2-m telescope of the University of Hawaii, the 2-m telescope at Pic du Midi, France, and with the Adonis adaptive optics camera at the 3.6-m telescope of the European Southern Observatory in Chile. Images from the Hubble Space Telescope, obtained in August 1995, are also reanalyzed. The radial brightness profiles of the rings indicate that the outer and usually faint F ring dominates the edge-on brightness of the system, thus hiding the vertical structure of the main rings within a few hours around the ring plane crossing. The photometric behaviors of the A, B, and C rings and of the Cassini Division are analyzed, using a radiative transfer code which includes the illuminations by the Sun and by the planet. The F ring is modeled as a physically thick ribbon of height H, composed of large particles embedded in dust of fractional optical depth f. The observed profiles, combined with previous results, can be explained if the F ring is both optically thick ( radial optical depth ˜0.20) and physically thick ( H=21±4 km). We suggest that this vertical distribution results from the interactions between ring particles and shepherding satellites and/or from gravitational stirring by large bodies. The dust particles dominate the F ring's photometric behavior even in backscattered light ( f>0.80). Constraints on the particle properties of the other rings are also derived.

Micron-scale intra-ring analyses of δ13C in early Eocene Arctic wood from Ellesmere Island

NASA Astrophysics Data System (ADS)

Schubert, B.; Jahren, H.; Eberle, J.; Sternberg, L.

2009-12-01

Early Eocene (ca. 53 Ma) fossil assemblages on Ellesmere Island (75 oN paleolatitude), provide rich information about the plant and animal life of the lush polar ecosystems of the time. Fossil wood recovered from Ellesmere Island is abundant and not permineralized; however, morphological features such as growth rings and resin canals have been obliterated by compression. We report on exceptionally high-resolution intra-ring analyses of δ13C within fossil wood, sampled at ~30 micron intervals across several centimeters of wood sample. Clear patterns in systematic seasonal increases and decreases in wood δ13C allowed us to identify at least 5 annual cycles in the wood. The patterns of increase and decrease in δ13C were consistent with patterns observed for evergreen wood, and distinct from the deciduous patterns we have observed for Metasequoia fossil wood from the middle Eocene (ca. 45 Ma) Arctic site on Axel Heiberg Island. We believe that the high point in the δ13C value of wood seen in each cycle corresponds to the highest environmental temperatures during the annual cycle, as has been seen for modern evergreens (e.g., Barbour et al., 2002). Modern studies have also noted that high temperature periods are correlated with the highest vapor-pressure and soil-water deficits of the annual cycle; these environmental factors would cause the plant to change its discrimination during photosynthesis. We will discuss the relatively low amplitude of δ13C fluctuations (0.5-1.0 ‰) clearly defined by Ellesmere fossil wood, in comparison to observations on modern common evergreens (2.0-4.0 ‰), and speculate that this difference implies greatly dampened seasonal temperature fluctuations in Eocene polar environments, relative to today. Barbour M.M., Walcroft A.S., Farquhar G.D., 2002, Seasonal variation in δ13C and δ18O of cellulose from growth rings of Pinus radiata. Plant, Cell and Environment: v. 25, p. 1483-1499.

Inorganic glass ceramic slip rings

NASA Technical Reports Server (NTRS)

Glossbrenner, E. W.; Cole, S. R.

1972-01-01

Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

Inferring biome-scale net primary productivity from tree-ring isotopes

NASA Astrophysics Data System (ADS)

Pederson, N.; Levesque, M.; Williams, A. P.; Hobi, M. L.; Smith, W. K.; Andreu-Hayles, L.

2017-12-01

Satellite estimates of vegetation growth (net primary productivity; NPP), tree-ring records, and forest inventories indicate that ongoing climate change and rising atmospheric CO2 concentration are altering productivity and carbon storage of forests worldwide. The impact of global change on the trends of NPP, however, remain unknown because of the lack of long-term high-resolution NPP data. For the first time, we tested if annually resolved carbon (δ13C) and oxygen (δ18O) stable isotopes from the cellulose of tree rings from trees in temperate regions could be used as a tool for inferring NPP across spatiotemporal scales. We compared satellite NPP estimates from the moderate-resolution imaging spectroradiometer sensor (MODIS, product MOD17A) and a newly developed global NPP dataset derived from the Global Inventory Modeling and Mapping Studies (GIMMS) dataset to annually resolved tree-ring width and δ13C and δ18O records from four sites along a hydroclimatic gradient in Eastern and Central United States. We found strong correlations across large geographical regions between satellite-derived NPP and tree-ring isotopes that ranged from -0.40 to -0.91. Notably, tree-ring derived δ18O had the strongest relation to climate. The results were consistent among the studied tree species (Quercus rubra and Liriodendron tulipifera) and along the hydroclimatic conditions of our network. Our study indicates that tree-ring isotopes can potentially be used to reconstruct NPP in time and space. As such, our findings represent an important breakthrough for estimating long-term changes in vegetation productivity at the biome scale.

Deployable Fresnel Rings

NASA Technical Reports Server (NTRS)

Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.; Lin, Gregory Y.

2014-01-01

Deployable Fresnel rings (DFRs) significantly enhance the realizable gain of an antenna. This innovation is intended to be used in combination with another antenna element, as the DFR itself acts as a focusing or microwave lens element for a primary antenna. This method is completely passive, and is also completely wireless in that it requires neither a cable, nor a connector from the antenna port of the primary antenna to the DFR. The technology improves upon the previous NASA technology called a Tri-Sector Deployable Array Antenna in at least three critical aspects. In contrast to the previous technology, this innovation requires no connector, cable, or other physical interface to the primary communication radio or sensor device. The achievable improvement in terms of antenna gain is significantly higher than has been achieved with the previous technology. Also, where previous embodiments of the Tri-Sector antenna have been constructed with combinations of conventional (e.g., printed circuit board) and conductive fabric materials, this innovation is realized using only conductive and non-conductive fabric (i.e., "e-textile") materials, with the possible exception of a spring-like deployment ring. Conceptually, a DFR operates by canceling the out-of-phase radiation at a plane by insertion of a conducting ring or rings of a specific size and distance from the source antenna, defined by Fresnel zones. Design of DFRs follow similar procedures to those outlined for conventional Fresnel zone rings. Gain enhancement using a single ring is verified experimentally and through computational simulation. The experimental test setup involves a microstrip patch antenna that is directly behind a single-ring DFR and is radiating towards a second microstrip patch antenna. The first patch antenna and DFR are shown. At 2.42 GHz, the DFR improves the transmit antenna gain by 8.6 dB, as shown in Figure 2, relative to the wireless link without the DFR. A figure illustrates the

Saddle-shaped mitral valve annuloplasty rings experience lower forces compared with flat rings.

PubMed

Jensen, Morten O; Jensen, Henrik; Smerup, Morten; Levine, Robert A; Yoganathan, Ajit P; Nygaard, Hans; Hasenkam, J Michael; Nielsen, Sten L

2008-09-30

New insight into the 3D dynamic behavior of the mitral valve has prompted a reevaluation of annuloplasty ring designs. Force balance analysis indicates correlation between annulus forces and stresses in leaflets and chords. Improving this stress distribution can intuitively enhance the durability of mitral valve repair. We tested the hypothesis that saddle-shaped annuloplasty rings have superior uniform systolic force distribution compared with a nonuniform force distribution in flat annuloplasty rings. Sixteen 80-kg pigs had a flat (n=8) or saddle-shaped (n=8) mitral annuloplasty ring implanted. Mitral annulus 3D dynamic geometry was obtained with sonomicrometry before ring insertion. Strain gauges mounted on dedicated D-shaped rigid flat and saddle-shaped annuloplasty rings provided the intraoperative force distribution perpendicular to the annular plane. Average systolic annular height to commissural width ratio before ring implantation was 14.0%+/-1.6%. After flat and saddle shaped ring implantation, the annulus was fixed in the diastolic (9.0%+/-1.0%) and systolic (14.3%+/-1.3%) configuration, respectively (P<0.01). Force accumulation was seen from the anterior (0.72N+/-0.14N) and commissural annular segments (average 1.38N+/-0.27N) of the flat rings. In these segments, the difference between the 2 types of rings was statistically significant (P<0.05). The saddle-shaped annuloplasty rings did not experience forces statistically significantly larger than zero in any annular segments. Saddle-shaped annuloplasty rings provide superior uniform annular force distribution compared to flat rings and appear to represent a configuration that minimizes out-of-plane forces that could potentially be transmitted to leaflets and chords. This may have important implications for annuloplasty ring selections.

14 CFR Appendix C to Part 125 - Ice Protection

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Ice Protection C Appendix C to Part 125... OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Pt. 125, App. C Appendix C to Part 125... conditions as described in appendix C of part 25 of this chapter. (c) Compliance with all or portions of this...

A new test machine for measuring friction and wear in controlled atmospheres to 1200 C

NASA Technical Reports Server (NTRS)

Sliney, Harold E.; Dellacorte, Christopher

1991-01-01

This paper describes a new high-temperature friction and wear test apparatus (tribometer). The tribometer can be used as a pin-on-disk or pin-on-ring configuration and is specially designed to measure the tribological properties of ceramics and high temperature metallic alloys from room temperature to 1200 C. Sliding mode can be selected to be either unidirectional at velocities up to 22 m/sec or oscillating at frequencies up to 4.6 Hz and amplitudes up to + or - 60 deg. The test atmosphere is established by a controlled flow rate of a purge gas. All components within the test chamber are compatible with oxidizing, inert or reducing gases.

Conversion of Weinreb amides into benzene rings incorporating the amide carbonyl carbon.

PubMed

Clive, Derrick L J; Pham, Mai P

2009-02-20

Esters, acids and acid chlorides can be converted via the intermediacy of their corresponding Weinreb amides into benzene derivatives that incorporate the original carbonyl carbon as part of the benzene ring. The process involves treatment of the derived Weinreb amides with 3-butenylmagnesium bromide and an allylic Grignard reagent, followed by ring-closing metathesis, dehydration and dehydrogenation. The dehydration-dehydrogenation can be done under acidic conditions with a mixture of TsOH x H(2)O and DDQ or in two steps with SOCl(2)/pyridine, followed by treatment with DDQ. Application of the method to carbohydrates provides a convenient route to C-5 aryl pyranosides.

Two F Ring Views

NASA Technical Reports Server (NTRS)

2005-01-01

These views, taken two hours apart, demonstrate the dramatic variability in the structure of Saturn's intriguing F ring.

In the image at the left, ringlets in the F ring and Encke Gap display distinctive kinks, and there is a bright patch of material on the F ring's inner edge. Saturn's moon Janus (181 kilometers, or 113 miles across) is shown here, partly illuminated by reflected light from the planet.

At the right, Prometheus (102 kilometers, or 63 miles across) orbits ahead of the radial striations in the F ring, called 'drapes' by scientists. The drapes appear to be caused by successive passes of Prometheus as it reaches the greatest distance (apoapse) in its orbit of Saturn. Also in this image, the outermost ringlet visible in the Encke Gap displays distinctive bright patches.

These views were obtained from about three degrees below the ring plane.

The images were taken in visible light with the Cassini spacecraft narrow-angle camera on June 29, 2005, when Cassini was about 1.5 million kilometers (900,000 miles) from Saturn. The image scale is about 9 kilometers (6 miles) per pixel.

Thermal vacuum real-life test of an Marconi Space and Defence Systems (MSDS) solar-array drive mechanism (MSDS 002). First four years of operation

NASA Astrophysics Data System (ADS)

Parker, K.; Douglas, A.; Burke, W. R.

1981-01-01

The first part of a 7 yr life test on a mechanism which turns a satellite solar array at 1rev/day is reported. A thermal transfer shroud, surrounding the mechanism in a vacuum chamber, is held at a constant temperature of 22.5 C while the shaft temperature, measured near the top of the shaft at the large bearing, is changed at 6-monthly intervals so that it operates alternately at 60 and 10 C. At the beginning of each 6-monthly cycle, 30 eclipse simulations are performed, i.e., the shaft temperature is reduced from 60 C to 0 C in 72 min and is returned to 60 C in as short a time as possible. Apart from a very small increase in motor power during eclipse simulation, no changes in the mechanism parameters occur with temperature. The mechanism operates within motor power and angular rotation accuracy specifications. The electrical noise on all slip rings increased during the first two years, but then slowly decreased. Certain slip ring pairs show a noise level in excess of the arbitrary limits set at the start of the test, and two slip ring pairs give large periodic noise transients which may be due to mechanical damage to the slip rings or brushes.

49 CFR Appendix C to Part 37 - Certifications

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 1 2013-10-01 2013-10-01 false Certifications C Appendix C to Part 37 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Pt. 37, App. C Appendix C to Part 37—Certifications Certification of Equivalent Service The...

Alternative Test Methods for Electronic Parts

NASA Technical Reports Server (NTRS)

Plante, Jeannette

2004-01-01

It is common practice within NASA to test electronic parts at the manufacturing lot level to demonstrate, statistically, that parts from the lot tested will not fail in service using generic application conditions. The test methods and the generic application conditions used have been developed over the years through cooperation between NASA, DoD, and industry in order to establish a common set of standard practices. These common practices, found in MIL-STD-883, MIL-STD-750, military part specifications, EEE-INST-002, and other guidelines are preferred because they are considered to be effective and repeatable and their results are usually straightforward to interpret. These practices can sometimes be unavailable to some NASA projects due to special application conditions that must be addressed, such as schedule constraints, cost constraints, logistical constraints, or advances in the technology that make the historical standards an inappropriate choice for establishing part performance and reliability. Alternate methods have begun to emerge and to be used by NASA programs to test parts individually or as part of a system, especially when standard lot tests cannot be applied. Four alternate screening methods will be discussed in this paper: Highly accelerated life test (HALT), forward voltage drop tests for evaluating wire-bond integrity, burn-in options during or after highly accelerated stress test (HAST), and board-level qualification.

The Search for Ringed Exoplanets

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-04-01

checks to eliminate false positives, the authors are left with one candidate: KIC 10403228.Rings or Not?Schematics of the two best-fitting ringed-exoplanet models for KIC 10403228, and the possible parameters of the system. The planet crosses the disk of the star from left to right with a grazing transit. [Adapted from Aizawa et al. 2017]Next, the authors apply a wide range of ringed-exoplanet models to KIC 10403228s light curve. They find two different scenarios that fit the data well: one in which the ring is significantly tilted with respect to the orbital plane, and another in which its only slightly tilted.The authors conclude by testing a variety of other scenarios that could explain the anomalies in the light curve instead. They find that two other scenarios are plausible: 1) the star is in an eclipsing binary system, with the second star surrounded by a circumstellar disk, and 2) the star is part of a hierarchical triple, and the transits are caused by a binary star system as it orbits KIC 10403228.Though Aizawa and collaborators arent able to rule either of these other two scenarios out, they suggest that follow-up spectroscopy or high-resolution imaging may help distinguish between the different scenarios. In the meantime, their methodology for systematically searching for ringed exoplanets has proven worthwhile, and they plan to extend it now to a larger data set. Perhaps well soon find other Saturn-like planets in our galaxy!CitationMasataka Aizawa () et al 2017 AJ 153 193. doi:10.3847/1538-3881/aa6336

The Tunguska event in 1908: evidence from tree-ring anatomy.

PubMed

Vaganov, Evgenii A; Hughes, Malcolm K; Silkin, Pavel P; Nesvetailo, Valery D

2004-01-01

We analyzed tree rings in wood samples collected from some of the few surviving trees found close to the epicenter (within 4-5 km) of the Tunguska event that occurred on the last day of June 1908. Tree-ring growth shows a depression starting in the year after the event and continuing during a 4-5-year period. The most remarkable traces of the event were found in the rings' anatomical structure: (1) formation of "light" rings and a reduction of maximum density in 1908; (2) non-thickened tracheids (the cells that make up most of the wood volume) in the transition and latewood zones (the middle and last-formed parts of the ring, respectively); and (3) deformed tracheids, which are located on the 1908 annual ring outer boundary. In the majority of samples, normal earlywood and latewood tracheids were formed in all annual rings after 1908. The observed anomalies in wood anatomy suggest two main impacts of the Tunguska event on surviving trees--(1) defoliation and (2) direct mechanical stress on active xylem tissue. The mechanical stress needed to fell trees is less than the stress needed to cause the deformation of differentiating tracheids observed in trees close to the epicenter. In order to resolve this apparent contradiction, work is suggested on possible topographic modification of the overpressure experienced by these trees, as is an experimental test of the effects of such stresses on precisely analogous growing trees.

Persistent pattern speeds in Saturn's D ring

NASA Astrophysics Data System (ADS)

Chancia, Robert; Hedman, Matthew M.

2016-05-01

Saturn's D ring is the innermost part of Saturn's ring system. Due to its close proximity to the planet, it is sensitive to perturbing forces caused by asymmetries in Saturn's interior and magnetic field. Using high-phase-angle images obtained by the Imaging Science Subsystem (ISS) over the course of the entire Cassini mission we investigate the region between 71000-73000 km from Saturn's center. Previous studies have shown that this region contains azimuthal brightness variations generated by periodic perturbing forces with frequencies close to Saturn's rotation rate (nearly twice the local orbital period). These structures are not due to a single resonance, but instead involve a complex network of patterns drifting past one another over time. Some of these could be caused by asymmetries in Saturn's magnetosphere, which have rotation rates that have been observed to change over the course of the Cassini mission. However, some patterns may be generated by perturbations from long-lived gravitational anomalies inside the planet that move at speeds comparable to Saturn's winds. By comparing observations taken over several years we can distinguish the patterns caused by each phenomenon. We identify multiple structures with nearly constant pattern speeds that would appear to be due to persistent structures inside the planet. Strangely, the rotation rates required to produce these D ring structures are different from those responsible for generating waves in the C ring (where the local orbital rate is roughly 3/2 Saturn's rotation rate).

Development of an in vitro Assay, Based on the BioFilm Ring Test®, for Rapid Profiling of Biofilm-Growing Bacteria

PubMed Central

Di Domenico, Enea G.; Toma, Luigi; Provot, Christian; Ascenzioni, Fiorentina; Sperduti, Isabella; Prignano, Grazia; Gallo, Maria T.; Pimpinelli, Fulvia; Bordignon, Valentina; Bernardi, Thierry; Ensoli, Fabrizio

2016-01-01

Microbial biofilm represents a major virulence factor associated with chronic and recurrent infections. Pathogenic bacteria embedded in biofilms are highly resistant to environmental and chemical agents, including antibiotics and therefore difficult to eradicate. Thus, reliable tests to assess biofilm formation by bacterial strains as well as the impact of chemicals or antibiotics on biofilm formation represent desirable tools for a most effective therapeutic management and microbiological risk control. Current methods to evaluate biofilm formation are usually time-consuming, costly, and hardly applicable in the clinical setting. The aim of the present study was to develop and assess a simple and reliable in vitro procedure for the characterization of biofilm-producing bacterial strains for future clinical applications based on the BioFilm Ring Test® (BRT) technology. The procedure developed for clinical testing (cBRT) can provide an accurate and timely (5 h) measurement of biofilm formation for the most common pathogenic bacteria seen in clinical practice. The results gathered by the cBRT assay were in agreement with the traditional crystal violet (CV) staining test, according to the κ coefficient test (κ = 0.623). However, the cBRT assay showed higher levels of specificity (92.2%) and accuracy (88.1%) as compared to CV. The results indicate that this procedure offers an easy, rapid and robust assay to test microbial biofilm and a promising tool for clinical microbiology. PMID:27708625

10 CFR Appendix C to Part 2 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false [Reserved] C Appendix C to Part 2 Energy NUCLEAR REGULATORY COMMISSION RULES OF PRACTICE FOR DOMESTIC LICENSING PROCEEDINGS AND ISSUANCE OF ORDERS Appendix C to Part 2 [Reserved] ...

10 CFR Appendix C to Part 2 - [Reserved

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false [Reserved] C Appendix C to Part 2 Energy NUCLEAR REGULATORY COMMISSION RULES OF PRACTICE FOR DOMESTIC LICENSING PROCEEDINGS AND ISSUANCE OF ORDERS Appendix C to Part 2 [Reserved] ...

17 CFR Appendix C to Part 145 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false [Reserved] C Appendix C to Part 145 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION COMMISSION RECORDS AND INFORMATION Appendix C to Part 145 [Reserved] ...

40 CFR Appendix C to Subpart F of... - Method for Testing Recovery Devices for Use With Small Appliances

Code of Federal Regulations, 2010 CFR

2010-07-01

... for Use With Small Appliances C Appendix C to Subpart F of Part 82 Protection of Environment... and Emissions Reduction Pt. 82, Subpt. F, App. C Appendix C to Subpart F of Part 82—Method for Testing... system. II. Test Conditions Tests are to be conducted at 75 degrees F, plus or minus 2 degrees F (23.9 C...

Formation of Cyclopenta[c]pyridine Derivatives from 2,5-Disubstituted Pyrroles and 1,4-Dibromo-1,3-butadienes via Pyrrole-Ring One-Carbon Expansion.

PubMed

Yin, Jianhao; Ye, Qingyu; Hao, Wei; Du, Shuaijing; Gu, Yucheng; Zhang, Wen-Xiong; Xi, Zhenfeng

2017-01-06

Reactions between 1,4-dibromo-1,3-butadienes and 2,5-disubstituted pyrroles afforded cyclopenta[c]pyridine derivatives in high yield, catalyzed by palladium and a cyclopentadiene-phosphine ligand (L1). Insertion of one terminal carbon of the butadienyl skeleton into one C═C double bond in the pyrrole ring resulted in ring expansion, along with a 1,2-shift of an alkyl or an aryl substituent on the butadienes.

49 CFR Appendix C to Part 213 - [Reserved

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false [Reserved] C Appendix C to Part 213 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Appendix C to Part 213[Reserved] ...

17 CFR Appendix C to Part 40 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false [Reserved] C Appendix C to Part 40 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION PROVISIONS COMMON TO REGISTERED ENTITIES Appendix C to Part 40 [Reserved] ...

49 CFR Appendix C to Part 238 - [Reserved

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false [Reserved] C Appendix C to Part 238 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Appendix C to Part 238 [Reserved] ...

17 CFR Appendix C to Part 1 - [Reserved

Code of Federal Regulations, 2014 CFR

2014-04-01

... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false [Reserved] C Appendix C to Part 1 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION GENERAL REGULATIONS UNDER THE COMMODITY EXCHANGE ACT Appendix C to Part 1 [Reserved] ...

14 CFR Appendix C to Part 43 - [Reserved

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false [Reserved] C Appendix C to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION Appendix C to Part 43 [Reserved] ...

14 CFR Appendix C to Part 43 - [Reserved

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false [Reserved] C Appendix C to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION Appendix C to Part 43 [Reserved] ...

49 CFR Appendix C to Part 238 - [Reserved

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false [Reserved] C Appendix C to Part 238 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Appendix C to Part 238 [Reserved] ...

14 CFR Appendix C to Part 43 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false [Reserved] C Appendix C to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION Appendix C to Part 43 [Reserved] ...

Tunable filters based on an SOI nano-wire waveguide micro ring resonator

NASA Astrophysics Data System (ADS)

Shuai, Li; Yuanda, Wu; Xiaojie, Yin; Junming, An; Jianguang, Li; Hongjie, Wang; Xiongwei, Hu

2011-08-01

Micro ring resonator (MRR) filters based on a silicon on insulator (SOI) nanowire waveguide are fabricated by electron beam photolithography (EBL) and inductive coupled plasma (ICP) etching technology. The cross-section size of the strip waveguides is 450 × 220 nm2, and the bending radius of the micro ring is around 5 μm. The test results from the tunable filter based on a single ring show that the free spectral range (FSR) is 16.8 nm and the extinction ratio (ER) around the wavelength 1550 nm is 18.1 dB. After thermal tuning, the filter's tuning bandwidth reaches 4.8 nm with a tuning efficiency of 0.12 nm/°C Meanwhile, we fabricated and studied multi-channel filters based on a single ring and a double ring. After measurement, we drew the following conclusions: during the signal transmission of multi-channel filters, crosstalk exists mainly among different transmission channels and are fairly distinct when there are signals input to add ports.

32 CFR Appendix C to Part 513 - Glossary

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Glossary C Appendix C to Part 513 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY AID OF CIVIL AUTHORITIES AND PUBLIC RELATIONS INDEBTEDNESS OF MILITARY PERSONNEL Pt. 513, App. C Appendix C to Part 513—Glossary Section I...

32 CFR Appendix C to Part 513 - Glossary

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 3 2013-07-01 2013-07-01 false Glossary C Appendix C to Part 513 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY AID OF CIVIL AUTHORITIES AND PUBLIC RELATIONS INDEBTEDNESS OF MILITARY PERSONNEL Pt. 513, App. C Appendix C to Part 513—Glossary Section I...

32 CFR Appendix C to Part 513 - Glossary

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 3 2012-07-01 2009-07-01 true Glossary C Appendix C to Part 513 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY AID OF CIVIL AUTHORITIES AND PUBLIC RELATIONS INDEBTEDNESS OF MILITARY PERSONNEL Pt. 513, App. C Appendix C to Part 513—Glossary Section I...

32 CFR Appendix C to Part 513 - Glossary

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 3 2011-07-01 2009-07-01 true Glossary C Appendix C to Part 513 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY AID OF CIVIL AUTHORITIES AND PUBLIC RELATIONS INDEBTEDNESS OF MILITARY PERSONNEL Pt. 513, App. C Appendix C to Part 513—Glossary Section I...

Formation of moon induced gaps in dense planetary rings

NASA Astrophysics Data System (ADS)

Grätz, F.; Seiß, M.; Spahn, F.

2017-09-01

Recent works have shown that bodies embedded in planetary rings create S-shaped density modula- tions called propellers if their mass deceeds a certain threshold or cause a gap around the entire circumference of the disc if the embedded bodies mass exceeds it. Two counteracting physical processes govern the dynamics and determine what structure is created: The gravitational disturber excerts a torque on nearby disc particles, sweeping them away from itself on both sides thus depleting the discs density and forming a gap. Diffusive spreading of the disc material due to collisions counteracts the gravitational scattering and has the tendency to fill the gap. We develop a nonlinear diffusion model that accounts for those two counteracting processes and describes the azimutally averaged surface density profile an embedded moon creates in planetary rings. The gaps width depends on the moons mass, its radial position and the rings viscosity allowing us to estimate the rings viscosity in the vicinity of the Encke and Keeler gap in Saturns A-Ring and compare it to previous measurements. We show that for the Keeler gap the time derivative of the semi-major axis as derived by Goldreich and Tremaine 1980 is underestimated yielding an underestimated viscosity for the ring. We therefore derive a corrected expression for said time derivative by fitting the solutions of Hill's equations for an ensemble of test particles. Furthermore we estimate the masses for potentionally unseen moonlets in the C-Ring and Cassini division.

Modular focusing ring imaging Cherenkov detector for electron–ion collider experiments

DOE PAGES

Wong, C. P.; Alfred, M.; Allison, L.; ...

2017-07-16

Here, a powerful new electron–ioncollider (EIC) has been recommended in the 2015 Long Range Plan for Nuclear Science for probing the partonic structure inside nucleons and nuclei with unprecedented precision and versatility. EIC detectors are currently under development, all of which require hadron identification over a broad kinematic range. A prototype ring imaging Cherenkov detector has been developed for hadron identification in the momentum range from 3 GeV/c to 10 GeV/c. The key feature of this new detector is a compact and modular design, achieved by using aerogel as radiator and a Fresnel lens for ring focusing. In this paper,more » the results from a beam test of a prototype device at Fermilab are reported.« less

Modular focusing ring imaging Cherenkov detector for electron-ion collider experiments

NASA Astrophysics Data System (ADS)

Wong, C. P.; Alfred, M.; Allison, L.; Awadi, M.; Azmoun, B.; Barbosa, F.; Barion, L.; Bennett, J.; Brooks, W.; Butler, C.; Cao, T.; Chiu, M.; Cisbani, E.; Contalbrigo, M.; Datta, A.; Del Dotto, A.; Demarteau, M.; Durham, J. M.; Dzhygadlo, R.; Elder, T.; Fields, D.; Furletova, Y.; Gleason, C.; Grosse-Perdekamp, M.; Harris, J.; Haseler, T. O. S.; He, X.; van Hecke, H.; Horn, T.; Hruschka, A.; Huang, J.; Hyde, C.; Ilieva, Y.; Kalicy, G.; Kimball, M.; Kistenev, E.; Kulinich, Y.; Liu, M.; Majka, R.; McKisson, J.; Mendez, R.; Nadel-Turonski, P.; Park, K.; Peters, K.; Rao, T.; Pisani, R.; Qiang, Y.; Rescia, S.; Rossi, P.; Sarajlic, O.; Sarsour, M.; Schwarz, C.; Schwiening, J.; da Silva, C. L.; Smirnov, N.; Stien, H. D.; Stevens, J.; Sukhanov, A.; Syed, S.; Tate, A. C.; Toh, J.; Towell, C. L.; Towell, R. S.; Tsang, T.; Turisini, M.; Wagner, R.; Wang, J.; Woody, C.; Xi, W.; Xie, J.; Zhao, Z. W.; Zihlmann, B.; Zorn, C.

2017-11-01

A powerful new electron-ioncollider (EIC) has been recommended in the 2015 Long Range Plan for Nuclear Science for probing the partonic structure inside nucleons and nuclei with unprecedented precision and versatility [1]. EIC detectors are currently under development [2], all of which require hadron identification over a broad kinematic range. A prototype ring imaging Cherenkov detector has been developed for hadron identification in the momentum range from 3 GeV/c to 10 GeV/c. The key feature of this new detector is a compact and modular design, achieved by using aerogel as radiator and a Fresnel lens for ring focusing. In this paper, the results from a beam test of a prototype device at Fermilab are reported.

Validation of an In Vitro Sun Protection Factor (SPF) method in blinded ring-testing.

PubMed

Pissavini, M; Tricaud, C; Wiener, G; Lauer, A; Contier, M; Kolbe, L; Trullás Cabanas, C; Boyer, F; Nollent, V; Meredith, E; Dietrich, E; Matts, P J

2018-04-20

The objective of this work was to investigate the utility of a new in vitro SPF test method in blinded ring-testing, against new ISO acceptance criteria. 24 blinded, commercial, emulsion-type, primary sunscreen products, covering the full range of labelled SPF in Europe (SPF6 - 50+), were tested by 3 test institutes using the current ISO24444:2010 In Vivo SPF Test Method and simultaneously by 3 separate test laboratories using a new candidate in vitro SPF test method, developed under the leadership of Cosmetics Europe (CE). The resulting relationship between in vitro SPF and in vivo SPF values was then compared with acceptance criteria developed recently by the International Standards (ISO) TC217 / WG7 Sun Protection Test Methods Working Group. Analysis of the mean inter-laboratory in vitro and mean inter-institute in vivo SPF values revealed a strong correlation between in vitro and in vivo values, with a Pearson correlation coefficient of r 2 =0.88 (p<0.0001), a slope of 1.01 and a non-significant intercept (-1.48; p=0.62). When these data were compared to the new ISO WG7 acceptance criteria, method bias was found to be extremely low and over 95% of the coupled data lay within the model "funnel" (defined by upper and lower confidence intervals). In conclusion, the results of blinded ring testing and comparison to new ISO WG7 acceptance criteria indicate that a new in vitro SPF test method meets (and exceeds) these minimum criteria and is an interesting candidate for possible deployment as an industry test methodology. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Constructing Highly Uniform Onion-Ring-like Graphitic Carbon Nitride for Efficient Visible-Light-Driven Photocatalytic Hydrogen Evolution.

PubMed

Cui, Lifeng; Song, Jialing; McGuire, Allister F; Kang, Shifei; Fang, Xueyou; Wang, Junjie; Yin, Chaochuang; Li, Xi; Wang, Yangang; Cui, Bianxiao

2018-06-13

The introduction of microstructure to the metal-free graphitic carbon nitride (g-C 3 N 4 ) photocatalyst holds promise in enhancing its catalytic performance. However, producing such microstructured g-C 3 N 4 remains technically challenging due to a complicated synthetic process and high cost. In this study, we develop a facile and in-air chemical vapor deposition (CVD) method that produces onion-ring-like g-C 3 N 4 microstructures in a simple, reliable, and economical manner. This method involves the use of randomly packed 350 nm SiO 2 microspheres as a hard template and melamine as a CVD precursor for the deposition of a thin layer of g-C 3 N 4 in the narrow space between the SiO 2 microspheres. After dissolution of the microsphere template, the resultant g-C 3 N 4 exhibits uniquely uniform onion-ring-like microstructures. Unlike previously reported g-C 3 N 4 powder morphologies that show various degrees of agglomeration and irregularity, the onion-ring-like g-C 3 N 4 is highly dispersed and uniform. The calculated band gap for onion-ring-like g-C 3 N 4 is 2.58 eV, which is significantly narrower than that of bulk g-C 3 N 4 at 2.70 eV. Experimental characterization and testing suggest that, in comparison with bulk g-C 3 N 4 , onion-ring-like g-C 3 N 4 facilitates charge separation, extends the lifetime of photoinduced carriers, exhibits 5-fold higher photocatalytic hydrogen evolution, and shows great potential for photocatalytic applications.

Screening methods for assessment of biodegradability of chemicals in seawater--results from a ring test

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

Nyholm, N.; Kristensen, P.

1992-04-01

An international ring test involving 14 laboratories was organized on behalf of the Commission of the European Economic Communities (EEC) with the purpose of evaluating two proposed screening methods for assessment of biodegradability in seawater: (a) a shake flask die-away test based primarily on analysis of dissolved organic carbon and (b) a closed bottle test based on determination of dissolved oxygen. Both tests are performed with nutrient-enriched natural seawater as the test medium and with no inoculum added other than the natural seawater microflora. The test methods are seawater versions of the modified OECD screening test and the closed bottlemore » test, respectively, adopted by the Organization for Economic Cooperation and Development (OECD) and by the EEC as tests for ready biodegradability.' The following five chemicals were examined: sodium benzoate, aniline, diethylene glycol, pentaerythritol, and 4-nitrophenol. Sodium benzoate and aniline, which are known to be generally readily biodegradable consistently degraded in practically all tests, thus demonstrating the technical feasibility of the methods. Like in previous ring tests with freshwater screening methods variable results were obtained with the other three compounds, which is believed primarily to be due to site-specific differences between the microflora of the different seawater samples used and to some extent also to differences in the applied concentrations of test material. A positive result with the screening methods indicates that the test substance will most likely degrade relatively rapidly in seawater from the site of collection, while a negative test result does not preclude biodegradability under environmental conditions where the concentrations of chemicals are much lower than the concentrations applied for analytical reasons in screening tests.« less

43 CFR Appendix C to Part 2 - Fee Schedule

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Fee Schedule C Appendix C to Part 2 Public... ACT Pt. 2, App. C Appendix C to Part 2—Fee Schedule If you submit a FOIA request, the bureau will... Subparts C and D of this part. The following fees will be used by all bureaus of the Department; these fees...

Development of a liquid metal slip ring

NASA Technical Reports Server (NTRS)

Weinberger, S. M.

1972-01-01

A liquid metal slip ring/solar orientation mechanism was designed and a model tested. This was a follow-up of previous efforts for the development of a gallium liquid metal slip ring in which the major problem was the formation and ejection of debris. A number of slip ring design approaches were studied. The probe design concept was fully implemented with detail drawings and a model was successfully tested for dielectric strength, shock vibration, acceleration and operation. The conclusions are that a gallium liquid metal slip ring/solar orientation mechanism is feasible and that the problem of debris formation and ejection has been successfully solved.

Formation of lunar basin rings

USGS Publications Warehouse

Hodges, C.A.; Wilhelms, D.E.

1978-01-01

The origin of the multiple concentric rings that characterize lunar impact basins, and the probable depth and diameter of the transient crater have been widely debated. As an alternative to prevailing "megaterrace" hypotheses, we propose that the outer scarps or mountain rings that delineate the topographic rims of basins-the Cordilleran at Orientale, the Apennine at Imbrium, and the Altai at Nectaris-define the transient cavities, enlarged relatively little by slumping, and thus are analogous to the rim crests of craters like Copernicus; inner rings are uplifted rims of craters nested within the transient cavity. The magnitude of slumping that occurs on all scarps is insufficient to produce major inner rings from the outer. These conclusions are based largely on the observed gradational sequence in lunar central uplifts:. from simple peaks through somewhat annular clusters of peaks, peak and ring combinations and double ring basins, culminating in multiring structures that may also include peaks. In contrast, belts of slump terraces are not gradational with inner rings. Terrestrial analogs suggest two possible mechanisms for producing rings. In some cases, peaks may expand into rings as material is ejected from their cores, as apparently occurred at Gosses Bluff, Australia. A second process, differential excavation of lithologically diverse layers, has produced nested experimental craters and is, we suspect, instrumental in the formation of terrestrial ringed impact craters. Peak expansion could produce double-ring structures in homogeneous materials, but differential excavation is probably required to produce multiring and peak-in-ring configurations in large lunar impact structures. Our interpretation of the representative lunar multiring basin Orientale is consistent with formation of three rings in three layers detected seismically in part of the Moon-the Cordillera (basin-bounding) ring in the upper crust, the composite Montes Rook ring in the underlying

Testing the reliability of δ13C of tree rings as climate tool in Pistacia khinjuk of Syrian desert

NASA Astrophysics Data System (ADS)

Caracuta, Valentina; Fiorentino, Girolamo

2010-05-01

High-resolution measures of past climate variations have been found to be of a critical importance for understanding anthropic resilience in drought-sensitive areas. The hills (Jebels) Abu-Rujmain and Abd al Aziz, with their 350 millimetre of rain and their steppe-forest spreading in the middle of the flat syrian desert, represent an unicum where analysing the effect of short term climate changes on pastoral communities. Thanks to a cooperation project in Syrian Arab republic with CIHEAM-Mediterranean Agronomic Institute of Bari -Italy (Rationalization of Ras El Ain Irrigation systems), we were allowed to carry out dendroclimate and carbon isotope analyses on tree-rings of local Pistacia khinjuk, a long-lived wood taxon, in order to test their reliability as tool for determining annual and seasonal rainfall/temperature variations. Comparison between the last 25 year rainfall and temperature values of the nearby meteorological stations and dendro-isotopes values have been carried out to point out which factor mostly affect the growth pattern of the trees in that particular area.

Modeling Saturnshine in Cassini Images of the Rings

NASA Astrophysics Data System (ADS)

Dones, Henry C.; Weiss, J. W.; Porco, C. C.; DiNino, D.; Skinner, R.

2013-10-01

In some viewing geometries, such as large solar phase angles or small solar elevation angles, the light reflected by or transmitted through Saturn's rings can be dominated by Saturnshine, i.e., illumination of the rings by the planet. Saturnshine results in longitudinal variations in the reflectivity of the rings. In addition, Saturn's A Ring and, to a lesser extent, B Ring, show intrinsic longitudinal variations ("azimuthal asymmetry") due to self-gravity wakes. Any attempt to infer physical properties of ring particles and their spatial distribution using ring photometry must consider both Saturnshine and self-gravity wakes. "Ringshine," in turn, complicates photometry of Saturn itself [1]. We have improved the Saturnshine model in [2], which applies a ray-tracing code to N-body simulations of a patch of Saturn's rings, by incorporating measurements of the planet's reflectivity in Cassini images taken in a range of viewing geometries through a number of broadband filters. We will compare the results of our photometric model with measurements of the I/F of the main rings, and will attempt to constrain the intrinsic properties of ring particles, such as their coefficients of restitution in collisions and internal densities. We thank the Cassini project for support. [1] Skinner, R.W., and Weiss, J.W. (2011). http://serc.carleton.edu/cismi/undergrad_research/posters/52679.html [2] Porco, C.C., et al. (2008). Astron J. 136, 2172-2200

The Effects of Forming Parameters on Conical Ring Rolling Process

PubMed Central

Meng, Wen; Zhao, Guoqun; Guan, Yanjin

2014-01-01

The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the “obtuse angle zone” of ring's cross-section are higher than those at “acute angle zone”; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained. PMID:25202716

Synthesis and antifungal activity of C-21 steroids with an aromatic D ring.

PubMed

Sonego, Juan M; Cirigliano, Adriana M; Cabrera, Gabriela M; Burton, Gerardo; Veleiro, Adriana S

2013-07-01

Six analogues of salpichrolides with a simplified side chain (6-11) were synthesized using a new methodology to obtain steroids with an aromatic D-ring. The key step was the elimination of HBr in a vicinal dibromo D-homosteroid by treatment with 1,4-diazabicyclo[2.2.2]octane (DABCO). All new compounds were completely characterized by 2D NMR techniques and tested on two fungal pathogenic species, Fusarium virguliforme and Fusarium solani. Copyright © 2013 Elsevier Inc. All rights reserved.

Planetary Rings

NASA Astrophysics Data System (ADS)

Esposito, Larry

2014-03-01

Preface: a personal view of planetary rings; 1. Introduction: the allure of the ringed planets; 2. Studies of planetary rings 1610-2013; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Uranus' rings and moons; 13. Neptune's partial rings; 14. Jupiter's ring-moon system after Galileo and New Horizons; 15. Ring photometry; 16. Dusty rings; 17. Concluding remarks; Afterword; Glossary; References; Index.

A new test machine for measuring friction and wear in controlled atmospheres to 1200 C

NASA Technical Reports Server (NTRS)

Sliney, Harold E.; Dellacorte, Christopher

1989-01-01

This paper describes a new high temperature friction and wear test apparatus (tribometer) at NASA Lewis Research Center, Cleveland, Ohio. The tribometer can be used as a pin-on-disk or pin-on-ring configuration and is specially designed to measure the tribological properties of ceramics and high temperature metallic alloys from room temperature to 1200 C. Sliding mode can be selected to be either unidirectional at velocities up to 22 m/sec or oscillating at frequencies up 4.5 Hz and amplitudes up to + or - 60 deg. The test atmosphere is established by a controlled flow rate of a purge gas. All components within the test chamber are compatible with oxidizing, inert, or reducing gases.

An Experimental Evaluation of Oil Pumping Rings

NASA Technical Reports Server (NTRS)

Eusepi, M. W.; Walowit, J.; Cohen, M.

1981-01-01

The design and construction of a reciprocating test vehicle to be used in evaluating hydrodynamic oil pumping rings are discussed. In addition, experimental test data are presented for three pumping ring designs that were constructed from Tin-Based Babbitt (SAE 11), Bearing Bronze (SAE 660), and Mechanical Carbon Graphite (Union Carbide Grade CNF-J). Data of pumped flow rate versus delivered pressure, as well as friction loss, are reported for the following conditions: frequencies of 10, 35 and 45 Hz; strokes of 25.4 mm (1.00 in.), 38.1 mm (1.50 in.) and 50.8 mm (2.00 in.) oil inlet temperature of 49 degrees (120 degrees); and pumping ring close-in pressures of 10.3 MPa (1500 lb/square inch. A 20W40 automotive oil was used for all tests. The maximum delivered pressure was 11 MPa (1600 lb/square inch. An analysis of hydrodynamic oil pumping rings was performed and the results of the analysis were compared to measured test data.

Experimental evaluation of the ring focus test for X-ray telescopes using AXAF's technology mirror assembly, MSFC CDDF Project No. H20

NASA Technical Reports Server (NTRS)

Zissa, D. E.; Korsch, D.

1986-01-01

A test method particularly suited for X-ray telescopes was evaluated experimentally. The method makes use of a focused ring formed by an annular aperture when using a point source at a finite distance. This would supplement measurements of the best focus image which is blurred when the test source is at a finite distance. The telescope used was the Technology Mirror Assembly of the Advanced X-ray Astrophysis Facility (AXAF) program. Observed ring image defects could be related to the azimuthal location of their sources in the telescope even though in this case the predicted sharp ring was obscured by scattering, finite source size, and residual figure errors.

14 CFR Appendix F to Part 43 - ATC Transponder Tests and Inspections

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false ATC Transponder Tests and Inspections F Appendix F to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... accordance with paragraph (c)(1) when using portable test equipment. (a) Radio Reply Frequency: (1) For all...

14 CFR Appendix F to Part 43 - ATC Transponder Tests and Inspections

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false ATC Transponder Tests and Inspections F Appendix F to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... accordance with paragraph (c)(1) when using portable test equipment. (a) Radio Reply Frequency: (1) For all...

14 CFR Appendix F to Part 43 - ATC Transponder Tests and Inspections

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false ATC Transponder Tests and Inspections F Appendix F to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... accordance with paragraph (c)(1) when using portable test equipment. (a) Radio Reply Frequency: (1) For all...

14 CFR Appendix F to Part 43 - ATC Transponder Tests and Inspections

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false ATC Transponder Tests and Inspections F Appendix F to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... accordance with paragraph (c)(1) when using portable test equipment. (a) Radio Reply Frequency: (1) For all...

14 CFR Appendix F to Part 43 - ATC Transponder Tests and Inspections

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false ATC Transponder Tests and Inspections F Appendix F to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... accordance with paragraph (c)(1) when using portable test equipment. (a) Radio Reply Frequency: (1) For all...

Four faces of the interaction between ions and aromatic rings.

PubMed

Papp, Dóra; Rovó, Petra; Jákli, Imre; Császár, Attila G; Perczel, András

2017-07-15

Non-covalent interactions between ions and aromatic rings play an important role in the stabilization of macromolecular complexes; of particular interest are peptides and proteins containing aromatic side chains (Phe, Trp, and Tyr) interacting with negatively (Asp and Glu) and positively (Arg and Lys) charged amino acid residues. The structures of the ion-aromatic-ring complexes are the result of an interaction between the large quadrupole moment of the ring and the charge of the ion. Four attractive interaction types are proposed to be distinguished based on the position of the ion with respect to the plane of the ring: perpendicular cation-π (CP ⊥ ), co-planar cation-π (CP ∥ ), perpendicular anion-π (AP ⊥ ), and co-planar anion-π (AP ∥ ). To understand more than the basic features of these four interaction types, a systematic, high-level quantum chemical study is performed, using the X -  + C 6 H 6 , M +  + C 6 H 6 , X -  + C 6 F 6 , and M +  + C 6 F 6 model systems with X -  = H - , F - , Cl - , HCOO - , CH 3 COO - and M +  = H + , Li + , Na + , NH4+, CH 3 NH3+, whereby C 6 H 6 and C 6 F 6 represent an electron-rich and an electron-deficient π system, respectively. Benchmark-quality interaction energies with small uncertainties, obtained via the so-called focal-point analysis (FPA) technique, are reported for the four interaction types. The computations reveal that the interactions lead to significant stabilization, and that the interaction energy order, given in kcal mol -1 in parentheses, is CP ⊥ (23-37) > AP ⊥ (14-21) > CP ∥ (9-22) > AP ∥ (6-16). A natural bond orbital analysis performed leads to a deeper qualitative understanding of the four interaction types. To facilitate the future quantum chemical characterization of ion-aromatic-ring interactions in large biomolecules, the performance of three density functional theory methods, B3LYP, BHandHLYP, and M06-2X, is tested against the FPA benchmarks

High Temperature Chemistry of Chlorinated Acenaphthylene. 3C Bay Acetylene Additions and Annealing by Five-Membered Ring Shifts.

PubMed

McIntosh, Grant J; Russell, Douglas K

2015-12-24

Experimental and theoretical results concerning the growth and isomerization of chlorinated acenaphthylene, C12H8, during the pyrolysis of chlorohydrocarbons are presented here. A fullerene subunit, C12H8, is a useful system to investigate regarding C60 formation. However, direct experimental observation of isomerization and annealing processes in particular are difficult to confirm due to the high symmetry of the parent molecule. Chlorination lowers the symmetry, essentially labeling carbon atoms, allowing growth and isomerization to be followed directly. Pyrolysis of dichloro- and trichloroethylene, and their copyrolyses with trichlorobenzenes, provides an efficient and general source of chlorinated acenaphthylenes in a range of degrees of chlorination and over a number of unique congeners. Analysis of congener yields as a function of reagents employed, guided by DFT/B3LYP/6-311G(d,p) level calculations, strongly suggests that C2 addition across three-carbon bays in naphthalene is a major driver of growth. Additionally, extremely facile five-membered ring shifts are operative, with chlorine promoting isomerization. Theoretical study of C16H10- and C18H10-based congeners indicate that this is a general phenomenon, and with chlorine also favoring internal cyclopentafused rings in addition to increased isomerization rates, this suggests halogen moieties may be an important feature for efficient fullerene growth.

Present and future of scientific bird ringing

USGS Publications Warehouse

Spina, F.; Tautin, J.; Adams, N.J.; Slotow, R.H.

1998-01-01

In 1999 scientific bird ringing will celebrate its first century of existence. Started mainly to investigate bird movements, bird ringing has become a much more flexible method to study different aspects of bird biology. Bird ringing can only be properly organised if an effective international co-operation exists. In Europe, this co-ordination is ensured by EURING, made of 35 national ringing centres; sister organisations exist in other parts of the world (like Africa, Australia, U.S. and Canada), sharing the same aims and problems. This RTD is mainly targeted to ornithologists involved with the co-ordination of bird ringing stations and national centres world-wide. Common aspects of the organisation of ringing activities, as well as of the potential ringing has and will have in the future in addressing major scientific questions in Ornithology will be taken into account. The advisability of setting up a standing committee on bird ringing within the IOC will be discussed, and the project of creating a world-wide organisation of ringing schemes in order to further improve communication and exchange of experiences will also be addressed. This new organisation would be formally founded in 1999, when an international conference organised by EURING to celebrate the first 100 years of bird ringing will be held in Denmark.

Present and future of scientific bird ringing

USGS Publications Warehouse

Spina, F.; Tautin, J.; Adams, N.J.; Slotow, R.H.

1999-01-01

In 1999 scientific bird ringing will celebrate its first century of existence. Started mainly to investigate bird movements, bird ringing has become a much more flexible method to study different aspects of bird biology. Bird ringing can only be properly organised if an effective international co-operation exists. In Europe, this co-ordination is ensured by EURING, made of 35 national ringing centres; sister organisations exist in other parts of the world (like Africa, Australia, U.S. and Canada), sharing the same aims and problems. This RTD is mainly targeted to ornithologists involved with the co-ordination of bird ringing stations and national centres world-wide. Common aspects of the organisation of ringing activities, as well as of the potential ringing has and will have in the future in addressing major scientific questions in Ornithology will be taken into account. The advisability of setting up a standing committee on bird ringing within the IOC will be discussed, and the project of creating a world-wide organisation of ringing schemes in order to further improve communication and exchange of experiences will also be addressed. This new organisation would be formally founded in 1999, when an international conference organised by EURING to celebrate the first 100 years of bird ringing will be held in Denmark.

75 FR 68613 - Part C Early Intervention Services Grant

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-08

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Health Resources and Services Administration Part C Early... non-competitive transfer of Part C funds from North General Hospital to the Institute for Family Health. SUMMARY: HRSA will be transferring Ryan White HIV/AIDS Program, Part C funds as a Non-Competitive...

Commercial Parts Radiation Testing

DTIC Science & Technology

2015-01-13

New Mexico’s COSMIAC Center performed radiation testing on a series of operational amplifiers, microcontrollers and microprocessor. The...commercial microcontroller and microprocessor equipment. The team would develop a list of the most promising commercial parts that might be utilized to...parts will include microprocessors, microcontrollers and memory modules. In addition, Field Programmable Gate Arrays (FPGAs) will also be chosen

Planetary Rings

NASA Astrophysics Data System (ADS)

Esposito, Larry W.

2011-07-01

Preface; 1. Introduction: the allure of ringed planets; 2. Studies of planetary rings 1610-2004; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-Body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Neptune's partial rings; 13. Jupiter's ring-moon system after Galileo; 14. Ring photometry; 15. Dusty rings; 16. Cassini observations; 17. Summary: the big questions; Glossary; References; Index.

Physics of planetary rings

NASA Astrophysics Data System (ADS)

Gorkavyi, N.

2007-08-01

It is difficult to enumerate all the surprises presented by the planetary rings. The Saturnian rings are stratified into thousands of ringlets and the Uranian rings are compressed into narrow streams, which for some reason or other differ from circular orbits like the wheel of an old bicycle. The edge of the rings is jagged and the rings themselves are pegged down under the gravitational pressure of the satellites, bending like a ship's wake. There are spiral waves, elliptical rings, strange interlacing of narrow ringlets, and to cap it all one has observed in the Neptunian ring system three dense, bright arcs - like bunches of sausages on a transparent string. For celestial mechanics this is a spectacle as unnatural as a bear's tooth in the necklace of the English queen. In the dynamics of planetary rings the physics of collective interaction was supplemented by taking collisions between particles into account. One was led to study a kinetic equation with a rather complex collision integral - because the collisions are inelastic - which later on made it possible, both by using the Chapman-Enskog method and by using the solution of the kinetic equation for a plasma in a magnetic field, to reduce it to a closed set of (hydrodynamical) moment equations [1]. The hydrodynamical instabilities lead to the growth of short-wavelength waves and large-scale structures of the Saturnian rings [1]. We have shown that the formation of the existing dense Uranian rings is connected with the capture of positively drifting ring particles in inner Lindblad resonances which arrest this drift [1]. After the formation of dense rings at the positions of satellite resonances the collective interaction between resonant particles is amplified and the rings can leave the resonance and drift away from the planet and the parent resonance. We can expect in the C ring an appreciable positive ballistic particle drift caused by the erosion of the B ring by micrometeorites. It is therefore natural

Rho1- and Pkc1-dependent phosphorylation of the F-BAR protein Syp1 contributes to septin ring assembly.

PubMed

Merlini, Laura; Bolognesi, Alessio; Juanes, Maria Angeles; Vandermoere, Franck; Courtellemont, Thibault; Pascolutti, Roberta; Séveno, Martial; Barral, Yves; Piatti, Simonetta

2015-09-15

In many cell types, septins assemble into filaments and rings at the neck of cellular appendages and/or at the cleavage furrow to help compartmentalize the plasma membrane and support cytokinesis. How septin ring assembly is coordinated with membrane remodeling and controlled by mechanical stress at these sites is unclear. Through a genetic screen, we uncovered an unanticipated link between the conserved Rho1 GTPase and its effector protein kinase C (Pkc1) with septin ring stability in yeast. Both Rho1 and Pkc1 stabilize the septin ring, at least partly through phosphorylation of the membrane-associated F-BAR protein Syp1, which colocalizes asymmetrically with the septin ring at the bud neck. Syp1 is displaced from the bud neck upon Pkc1-dependent phosphorylation at two serines, thereby affecting the rigidity of the new-forming septin ring. We propose that Rho1 and Pkc1 coordinate septin ring assembly with membrane and cell wall remodeling partly by controlling Syp1 residence at the bud neck. © 2015 Merlini et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

International Space Station Alpha's bearing, motor, and roll ring module developmental testing and results

NASA Technical Reports Server (NTRS)

Obrien, David L.

1994-01-01

This paper presents the design and developmental testing associated with the bearing, motor, and roll ring module (BMRRM) used for the beta rotation axis on International Space Station Alpha (ISSA). The BMRRM with its controllers located in the electronic control unit (ECU), provides for the solar array pointing and tracking functions as well as power and signal transfer across a rotating interface.

Hemoglobin A1c (HbA1c) Test: MedlinePlus Lab Test Information

MedlinePlus

... medlineplus.gov/labtests/hemoglobina1chba1ctest.html Hemoglobin A1c (HbA1c) Test To use the sharing features on this page, ... enable JavaScript. What is a hemoglobin A1c (HbA1c) test? A hemoglobin A1c (HbA1c) test measures the amount ...

49 CFR Appendix B to Part 173 - Procedure for Testing Chemical Compatibility and Rate of Permeation in Plastic Packaging and...

Code of Federal Regulations, 2014 CFR

2014-10-01

... Rate of Permeation in Plastic Packaging and Receptacles B Appendix B to Part 173 Transportation Other..., App. B Appendix B to Part 173—Procedure for Testing Chemical Compatibility and Rate of Permeation in... °C. (64 °F.) b. Test Method 2: 28 days at a temperature no lower than 50 °C. (122 °F.) c. Test Method...

Appearance of Saturn’s F ring azimuthal channels for the anti-alignment configuration between the ring and Prometheus

NASA Astrophysics Data System (ADS)

Chavez, Carlos E.

2009-09-01

In this article we explore the aspect of the F ring with respect to the anti-alignment configuration between the ring and Prometheus. We focus our attention on the shape of the F ring's azimuthal channels which were first reported by Porco et al. (Porco, C.C., Baker, E., Barbara, J., Beurle, K., Brahic, A., Burns, J.A., Charnoz, S., Cooper, N., Dawson, D.D., Del Genio, A.D., Denk, T., Dones, L., Dyudina, U., Evans, M.W., Giese, B., Grazier, K., Helfenstein, P., Ingersoll, A.P., Jacobson, R.A., Johnson, T.V., McEwen, A., Murray, C.D., Neukum, G., Owen, W.M., Perry, J., Roatsch, T., Spitale, J., Squyres, S., Thomas, P., Tiscareno, M., Turtle, E., Vasavada, A.R., Veverka, J., Wagner, R., West, R. [2005] Science, 307, 1226-1236) and numerically explored by Murray et al. (Murray, C.D., Chavez, C., Beurle, K., Cooper, N., Evans, M.W., Burns, J.A., Porco, C.C. [2005] Nature 437, 1326-1329) who found excellent agreement between Cassini's ISS reprojected images and their numerical model via a direct comparison. We find that for anti-alignment the channels are wider and go deeper inside the ring material. From our numerical model we find a new feature, an island in the middle of the channel. This island is made up of the particles that have been perturbed the most by Prometheus and only appears when this satellite is close to apoapsis. In addition, plots of the anti-alignment configuration for different orbital stages of Prometheus are obtained and discussed here.

Climatic response of annual tree-rings

NASA Astrophysics Data System (ADS)

Ageev, Boris G.; Gruzdev, Aleksandr N.; Ponomarev, Yurii N.; Sapozhnikova, Valeria A.

2014-11-01

Extensive literature devoted to investigations into the influence of environmental conditions on the plant respiration and respiration rate. It is generally accepted that the respired CO2 generated in a stem completely diffuses into the atmosphere. Results obtained from explorations into the CO2 content in disc tree rings by the method proposed in this work shows that a major part of CO2 remains in tree stems and exhibits inter-annual variability. Different methods are used to describe of CO2 and H2O distributions in disc tree rings. The relation of CO2 and H2O variations in a Siberian stone pine disc to meteorological parameters are analyzed with use of wavelet, spectral and cross-spectral techniques. According to a multiple linear regression model, the time evolution of the width of Siberian stone pine rings can be partly explained by a combined influence of air temperature, precipitation, cloudiness and solar activity. Conclusions are made regarding the response of the CO2 and H2O content in coniferous tree disc rings to various climatic factors. Suggested method of CO2, (CO2+H2O) detection can be used for studying of a stem respiration in ecological risk areas.

Saturn's dynamic D ring

USGS Publications Warehouse

Hedman, M.M.; Burns, J.A.; Showalter, M.R.; Porco, C.C.; Nicholson, P.D.; Bosh, A.S.; Tiscareno, M.S.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Clark, R.

2007-01-01

The Cassini spacecraft has provided the first clear images of the D ring since the Voyager missions. These observations show that the structure of the D ring has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, <40-km wide ringlet to a much broader and more diffuse 250-km wide feature. In addition, its center of light has shifted inwards by over 200 km relative to other features in the D ring. Cassini also finds that the locations of other narrow features in the D ring and the structure of the diffuse material in the D ring differ from those measured by Voyager. Furthermore, Cassini has detected additional ringlets and structures in the D ring that were not observed by Voyager. These include a sheet of material just interior to the inner edge of the C ring that is only observable at phase angles below about 60??. New photometric and spectroscopic data from the ISS (Imaging Science Subsystem) and VIMS (Visual and Infrared Mapping Spectrometer) instruments onboard Cassini show the D ring contains a variety of different particle populations with typical particle sizes ranging from 1 to 100 microns. High-resolution images reveal fine-scale structures in the D ring that appear to be variable in time and/or longitude. Particularly interesting is a remarkably regular, periodic structure with a wavelength of ??? 30 ?? km extending between orbital radii of 73,200 and 74,000 km. A similar structure was previously observed in 1995 during the occultation of the star GSC5249-01240, at which time it had a wavelength of ??? 60 ?? km. We interpret this structure as a periodic vertical corrugation in the D ring produced by differential nodal regression of an initially inclined ring. We speculate that this structure may have formed in response to an impact with a comet or meteoroid in early 1984. ?? 2006 Elsevier Inc. All rights reserved.

The 1995 Saturn Ring-Plane Crossings: Ring Thickness and Small Inner Satellites

NASA Astrophysics Data System (ADS)

Poulet, F.; Sicardy, B.

1996-09-01

The May 22() th and August 10() th, 1995, Saturn ring-plane crossings by the Earth were observed from the 2-m and 1-m telescopes at Pic du Midi, the 2.2-m telescope of the University of Hawaii, and with the Adonis adaptive optics camera at the 3.6-m telescope of the European Southern Observatory (ESO). Observations were made with either a 0.9 mu m or 2.2 mu m (short K) methane band filter. The radial brightness profiles of the rings indicate that the outer F ring dominates the apparent edge-on thickness of the system, with a vertically integrated equivalent width of 0.8-1.0 km near a radius of 130,000 km. The photometric behaviors of the A, B, and C rings and of the Cassini Division have been analyzed using a classical radiative transfer code which includes illumination by the Sun and by the planet. The F ring is modelled as a physically thick ribbon (thickness h) composed of large particles embedded in dust. The observed profiles can be explained if the F ring is both optically thick (tau ~ 0.15-0.25), and physically thick (h at least ~ 1.5 km). The large particles dominate the F ring's photometric behavior in backscattered light. Constraints on the particle properties in the other rings have been derived. The dimming of the rings around August 10, 1995 provided ideal conditions to study the small inner satellites. Besides Janus, Epimetheus and Pandora, two unresolved objects were detected in the ESO frames. They have been identified with the objects 1995S5 and 1995S6, detected several hours later by the Hubble Space Telescope (Nicholson et al. 1996, Science 272, 509--515). Combining the ESO and HST data, we derive orbital and photometric parameters for these objects. In particular, we improve the orbital parameters of 1995S5, whose orbital radius is now close to that of the F ring.

Vortex Ring Interaction with a Heated Screen

NASA Astrophysics Data System (ADS)

Smith, Jason; Krueger, Paul S.

2008-11-01

Previous examinations of vortex rings impinging on porous screens has shown the reformation of the vortex ring with a lower velocity after passing through the screen, the creation of secondary vortices, and mixing. A heated screen could, in principle, alter the vortex-screen interaction by changing the local liquid viscosity and density. In the present investigation, a mechanical piston-cylinder vortex ring generator was used to create vortex rings in an aqueous sucrose solution. The rings impinged on a screen of horizontal wires that were heated using electrical current. The flow was visualized with food color and video imaging. Tests with and without heat were conducted at a piston stroke-to-jet diameter ratio of 4 and a jet Reynolds number (Re) of 1000. The vortex rings slowed after passing through the screen, but in tests with heat, they maintained a higher fraction of their before-screen velocity due to reduction in fluid viscosity near the wires. In addition, small ``fingers'' that developed on the front of the vortex rings as they passed through the screen exhibited positive buoyancy effects in the heated case.

The opposition and tilt effects of Saturn’s rings from HST observations

NASA Astrophysics Data System (ADS)

Salo, Heikki; French, Richard G.

2010-12-01

The two major factors contributing to the opposition brightening of Saturn's rings are (i) the intrinsic brightening of particles due to coherent backscattering and/or shadow hiding on their surfaces, and (ii) the reduced interparticle shadowing when the solar phase angle α → 0°. We utilize the extensive set of Hubble Space Telescope observations (Cuzzi, J.N., French, R.G., Dones, L. [2002]. Icarus 158, 199-223) for different elevation angles B and wavelengths λ to disentangle these contributions. We assume that the intrinsic contribution is independent of B, so that any B dependence of the phase curves is due to interparticle shadowing, which must also act similarly for all λ's. Our study complements that of Poulet et al. (Poulet, F., Cuzzi, J.N., French, R.G., Dones, L. [2002]. Icarus 158, 224), who used a subset of data for a single B ˜ 10°, and the French et al. (French, R.G., Verbiscer, A., Salo, H., McGhee, C.A., Dones, L. [2007b] PASP 119, 623-642) study for the B ˜ 23° data set that included exact opposition. We construct a grid of dynamical/photometric simulation models, with the method of Salo and Karjalainen (Salo and Karjalainen [2003]. Icarus 164, 428-460), and use these simulations to fit the elevation-dependent part of opposition brightening. Eliminating the modeled interparticle component yields the intrinsic contribution to the opposition effect: for the B and A rings it is almost entirely due to coherent backscattering; for the C ring, an intraparticle shadow hiding contribution may also be present. Based on our simulations, the width of the interparticle shadowing effect is roughly proportional to B. This follows from the observation that as B decreases, the scattering is primarily from the rarefied low filling factor upper ring layers, whereas at larger B's the dense inner parts are visible. Vertical segregation of particle sizes further enhances this effect. The elevation angle dependence of interparticle shadowing also explains most

Dynamic Breaking Tests of Airplane Parts

NASA Technical Reports Server (NTRS)

Hertel, Heinrich

1933-01-01

The static stresses of airplane parts, the magnitude of which can be determined with the aid of static load assumptions, are mostly superposed by dynamic stresses, the magnitude of which has been but little explored. The object of the present investigation is to show how the strength of airplane parts can best be tested with respect to dynamic stresses with and without superposed static loading, and to what extent the dynamic strength of the parts depends on their structural design. Experimental apparatus and evaluation methods were developed and tried for the execution of vibration-strength tests with entire structural parts both with and without superposed static loading. Altogether ten metal spars and spar pieces and two wooden spars were subjected to vibration breaking tests.

40 CFR Appendix C to Part 67 - Computer Program

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Computer Program C Appendix C to Part... APPROVAL OF STATE NONCOMPLIANCE PENALTY PROGRAM Pt. 67, App. C Appendix C to Part 67—Computer Program Note: EPA will make copies of appendix C available from: Director, Stationary Source Compliance Division, EN...

Edwards nXDS15iC Vacuum Scroll Pump Pressure Testing

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

Sessions, H.; Morgan, G. A.

2013-07-17

The SRNL High Pressure Laboratory performed testing on an Edwards Model nXDS15iC Vacuum Scroll Pump on July 10th and 11th of 2013 at 723-A. This testing was done in an attempt to obtain initial compression ratio information for the nXDS15iC pump, with compression ratio defined as discharge pressure of the pump divided by suction pressure. Pressure burst testing was also done on the pump to determine its design pressure for pressure safety reasons. The Edwards nXDS15iC pump is being evaluated by SRNL for use part of the SHINE project being executed by SRNL.

14 CFR Appendix C to Part 420 - Risk Analysis

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Risk Analysis C Appendix C to Part 420... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Pt. 420, App. C Appendix C to Part 420—Risk Analysis (a... table C-1. Table C-1 provides sources where an applicant may obtain data acceptable to the FAA. An...

Role of four-membered rings in C32 fullerene stability and mechanisms of generalized Stone-Wales transformation: a density functional theory investigation.

PubMed

Wang, Weiwei; Dang, Jingshuang; Zhao, Xiang

2011-08-28

Density functional theory (DFT) methods have been applied to study C(32) fullerenes built from four-, five-, and six-membered rings. The relative energies of pure C(32) fullerenes have been evaluated to locate three most stable structures, 32:D(4d) with two squares, 1:D(3) without square and 5:C(s) with one square. Structural analysis reveals that there is a rearrangement pathway between the lowest energy classical isomer 1:D(3) and the lowest energy non-classical isomer 32:D(4d), and 5:C(s) behaves just as an intermediate between them. The kinetic processes of generalized Stone-Wales transformation (GSWT) with four-membered rings have been explored and two distinct reaction mechanisms are determined by all the transition states and intrinsic reaction coordinates with PBE1PBE/6-31G(d) approach for the first time. One mechanism is the concerted reaction with a rotating dimer closed to the cage surface and another is the stepwise reaction with a carbene-like sp(3) structure, whereas the latter is sorted into two paths based on four-membered ring vanishing before or after the formation of the carbene-like structure. It is indicated that there is no absolute preference for any mechanism, which depends on the adaptability of different reactants on the diverse mechanisms. Furthermore, it's found that the interconversion process with the participation of squares is more reactive than the rearrangement between C(60)_I(h) and C(60)_C(2v), implying some potential importance of non-classical small fullerenes in the fullerene isomerization.

Nitrited-Steel Piston Rings for Engines of High Specific Power

NASA Technical Reports Server (NTRS)

Collins, John H; Bisson, Edmond E; Schmiedlin, Ralph F

1945-01-01

Stability and control characteristics determined from tests in the Langley 19-foot pressure tunnel of a 0.2375-scale model of the Douglas XA-26 airplane are compared with those measured in flight tests of a Douglas A-26b airplane. Several designs of nitrided-steel piston rings were performance-tested under variable conditions of output. The necessity of good surface finish and conformity of the ring to the bore was indicated in the preliminary tests. Nitrided-steel rings of the same dimensions as cast-iron rings operating on the original piston were unsatisfactory, and the final design was a lighter, rectangular, thin-face-width ring used on a piston having a maximum cross-head area and a revised skirt shape. Results were obtained from single-cylinder and multicylinder engine runs.

49 CFR Schedule C to Subpart B of... - Schedule C to Subpart B of Part 1139

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 8 2014-10-01 2014-10-01 false Schedule C to Subpart B of Part 1139 C Schedule C... REVENUE PROCEEDINGS Intercity Bus Industry Pt. 1139, Subpt. B, Sch. C Schedule C to Subpart B of Part 1139 Attachment 1 Schedule C Part I—Condensed Income Statement [Dollars in thousands] () Greyhound Lines, Inc...

49 CFR Schedule C to Subpart B of... - Schedule C to Subpart B of Part 1139

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 8 2011-10-01 2011-10-01 false Schedule C to Subpart B of Part 1139 C Schedule C... REVENUE PROCEEDINGS Intercity Bus Industry Pt. 1139, Subpt. B, Sch. C Schedule C to Subpart B of Part 1139 Attachment 1 Schedule C Part I—Condensed Income Statement [Dollars in thousands] () Greyhound Lines, Inc...

49 CFR Schedule C to Subpart B of... - Schedule C to Subpart B of Part 1139

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 8 2010-10-01 2010-10-01 false Schedule C to Subpart B of Part 1139 C Schedule C... REVENUE PROCEEDINGS Intercity Bus Industry Pt. 1139, Subpt. B, Sch. C Schedule C to Subpart B of Part 1139 Attachment 1 Schedule C Part I—Condensed Income Statement [Dollars in thousands] () Greyhound Lines, Inc...

40 CFR Appendix C to Part 66 - Computer Program

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 16 2012-07-01 2012-07-01 false Computer Program C Appendix C to Part 66 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ASSESSMENT AND COLLECTION OF NONCOMPLIANCE PENALTIES BY EPA Pt. 66, App. C Appendix C to Part 66—Computer...

40 CFR Appendix C to Part 66 - Computer Program

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 16 2014-07-01 2014-07-01 false Computer Program C Appendix C to Part 66 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ASSESSMENT AND COLLECTION OF NONCOMPLIANCE PENALTIES BY EPA Pt. 66, App. C Appendix C to Part 66—Computer...

40 CFR Appendix C to Part 66 - Computer Program

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 16 2013-07-01 2013-07-01 false Computer Program C Appendix C to Part 66 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ASSESSMENT AND COLLECTION OF NONCOMPLIANCE PENALTIES BY EPA Pt. 66, App. C Appendix C to Part 66—Computer...

31 CFR Appendix C to Part 356 - Investment Considerations

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Investment Considerations C Appendix C to Part 356 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued...-93) Pt. 356, App. C Appendix C to Part 356—Investment Considerations I. Inflation-Protected...

31 CFR Appendix C to Part 356 - Investment Considerations

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Investment Considerations C Appendix C to Part 356 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued...) Pt. 356, App. C Appendix C to Part 356—Investment Considerations I. Inflation-Protected Securities A...

14 CFR Appendix C to Part 29 - Icing Certification

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Icing Certification C Appendix C to Part 29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Pt. 29, App. C Appendix C to Part 29—Icing Certification (a...

40 CFR Appendix C to Part 66 - Computer Program

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Computer Program C Appendix C to Part 66 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ASSESSMENT AND COLLECTION OF NONCOMPLIANCE PENALTIES BY EPA Pt. 66, App. C Appendix C to Part 66—Computer...

STED nanoscopy of the centrosome linker reveals a CEP68-organized, periodic rootletin network anchored to a C-Nap1 ring at centrioles.

PubMed

Vlijm, Rifka; Li, Xue; Panic, Marko; Rüthnick, Diana; Hata, Shoji; Herrmannsdörfer, Frank; Kuner, Thomas; Heilemann, Mike; Engelhardt, Johann; Hell, Stefan W; Schiebel, Elmar

2018-03-06

The centrosome linker proteins C-Nap1, rootletin, and CEP68 connect the two centrosomes of a cell during interphase into one microtubule-organizing center. This coupling is important for cell migration, cilia formation, and timing of mitotic spindle formation. Very little is known about the structure of the centrosome linker. Here, we used stimulated emission depletion (STED) microscopy to show that each C-Nap1 ring at the proximal end of the two centrioles organizes a rootletin ring and, in addition, multiple rootletin/CEP68 fibers. Rootletin/CEP68 fibers originating from the two centrosomes form a web-like, interdigitating network, explaining the flexible nature of the centrosome linker. The rootletin/CEP68 filaments are repetitive and highly ordered. Staggered rootletin molecules (N-to-N and C-to-C) within the filaments are 75 nm apart. Rootletin binds CEP68 via its C-terminal spectrin repeat-containing region in 75-nm intervals. The N-to-C distance of two rootletin molecules is ∼35 to 40 nm, leading to an estimated minimal rootletin length of ∼110 nm. CEP68 is important in forming rootletin filaments that branch off centrioles and to modulate the thickness of rootletin fibers. Thus, the centrosome linker consists of a vast network of repeating rootletin units with C-Nap1 as ring organizer and CEP68 as filament modulator. Copyright © 2018 the Author(s). Published by PNAS.

A Test of Carbon and Oxygen Stable Isotope Ratio Process Models in Tree Rings.

NASA Astrophysics Data System (ADS)

Roden, J. S.; Farquhar, G. D.

2008-12-01

Stable isotopes ratios of carbon and oxygen in tree ring cellulose have been used to infer environmental change. Process-based models have been developed to clarify the potential of historic tree ring records for meaningful paleoclimatic reconstructions. However, isotopic variation can be influenced by multiple environmental factors making simplistic interpretations problematic. Recently, the dual isotope approach, where the variation in one stable isotope ratio (e.g. oxygen) is used to constrain the interpretation of variation in another (e.g. carbon), has been shown to have the potential to de-convolute isotopic analysis. However, this approach requires further testing to determine its applicability for paleo-reconstructions using tree-ring time series. We present a study where the information needed to parameterize mechanistic models for both carbon and oxygen stable isotope ratios were collected in controlled environment chambers for two species (Pinus radiata and Eucalyptus globulus). The seedlings were exposed to treatments designed to modify leaf temperature, transpiration rates, stomatal conductance and photosynthetic capacity. Both species were grown for over 100 days under two humidity regimes that differed by 20%. Stomatal conductance was significantly different between species and for seedlings under drought conditions but not between other treatments or humidity regimes. The treatments produced large differences in transpiration rate and photosynthesis. Treatments that effected photosynthetic rates but not stomatal conductance influenced carbon isotope discrimination more than those that influenced primarily conductance. The various treatments produced a range in oxygen isotope ratios of 7 ‰. Process models predicted greater oxygen isotope enrichment in tree ring cellulose than observed. The oxygen isotope ratios of bulk leaf water were reasonably well predicted by current steady-state models. However, the fractional difference between models that

Vaginal rings for delivery of HIV microbicides

PubMed Central

Malcolm, R Karl; Fetherston, Susan M; McCoy, Clare F; Boyd, Peter; Major, Ian

2012-01-01

Following the successful development of long-acting steroid-releasing vaginal ring devices for the treatment of menopausal symptoms and contraception, there is now considerable interest in applying similar devices to the controlled release of microbicides against HIV. In this review article, the vaginal ring concept is first considered within the wider context of the early advances in controlled-release technology, before describing the various types of ring device available today. The remainder of the article highlights the key developments in HIV microbicide-releasing vaginal rings, with a particular focus on the dapivirine ring that is presently in late-stage clinical testing. PMID:23204872

Vaginal rings for delivery of HIV microbicides.

PubMed

Malcolm, R Karl; Fetherston, Susan M; McCoy, Clare F; Boyd, Peter; Major, Ian

2012-01-01

Following the successful development of long-acting steroid-releasing vaginal ring devices for the treatment of menopausal symptoms and contraception, there is now considerable interest in applying similar devices to the controlled release of microbicides against HIV. In this review article, the vaginal ring concept is first considered within the wider context of the early advances in controlled-release technology, before describing the various types of ring device available today. The remainder of the article highlights the key developments in HIV microbicide-releasing vaginal rings, with a particular focus on the dapivirine ring that is presently in late-stage clinical testing.

Characterization and Promoter Analysis of a Cotton Ring-Type Ubiquitin Ligase (E3) Gene

USDA-ARS?s Scientific Manuscript database

A cotton fiber cDNA, GhRING1, and its corresponding gene have been cloned and characterized. The GhRING1 gene encodes a RING-type ubiquitin ligase (E3) containing 337 amino acids (aa). The GhRING1 protein contains a RING finger motif with conserved cysteine and histine residues at the C-terminus a...

UV-laser-based microscopic dissection of tree rings - a novel sampling tool for δ(13) C and δ(18) O studies.

PubMed

Schollaen, Karina; Heinrich, Ingo; Helle, Gerhard

2014-02-01

UV-laser-based microscopic systems were utilized to dissect and sample organic tissue for stable isotope measurements from thin wood cross-sections. We tested UV-laser-based microscopic tissue dissection in practice for high-resolution isotopic analyses (δ(13) C/δ(18) O) on thin cross-sections from different tree species. The method allows serial isolation of tissue of any shape and from millimetre down to micrometre scales. On-screen pre-defined areas of interest were automatically dissected and collected for mass spectrometric analysis. Three examples of high-resolution isotopic analyses revealed that: in comparison to δ(13) C of xylem cells, woody ray parenchyma of deciduous trees have the same year-to-year variability, but reveal offsets that are opposite in sign depending on whether wholewood or cellulose is considered; high-resolution tree-ring δ(18) O profiles of Indonesian teak reflect monsoonal rainfall patterns and are sensitive to rainfall extremes caused by ENSO; and seasonal moisture signals in intra-tree-ring δ(18) O of white pine are weighted by nonlinear intra-annual growth dynamics. The applications demonstrate that the use of UV-laser-based microscopic dissection allows for sampling plant tissue at ultrahigh resolution and unprecedented precision. This new technique facilitates sampling for stable isotope analysis of anatomical plant traits like combined tree eco-physiological, wood anatomical and dendroclimatological studies. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

40 CFR Appendix C to Part 67 - Computer Program

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 16 2013-07-01 2013-07-01 false Computer Program C Appendix C to Part 67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) EPA APPROVAL OF STATE NONCOMPLIANCE PENALTY PROGRAM Pt. 67, App. C Appendix C to Part 67—Computer Program Note...

40 CFR Appendix C to Part 67 - Computer Program

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 16 2014-07-01 2014-07-01 false Computer Program C Appendix C to Part 67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) EPA APPROVAL OF STATE NONCOMPLIANCE PENALTY PROGRAM Pt. 67, App. C Appendix C to Part 67—Computer Program Note...

40 CFR Appendix C to Part 67 - Computer Program

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 16 2012-07-01 2012-07-01 false Computer Program C Appendix C to Part 67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) EPA APPROVAL OF STATE NONCOMPLIANCE PENALTY PROGRAM Pt. 67, App. C Appendix C to Part 67—Computer Program Note...

40 CFR Appendix C to Part 67 - Computer Program

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Computer Program C Appendix C to Part 67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) EPA APPROVAL OF STATE NONCOMPLIANCE PENALTY PROGRAM Pt. 67, App. C Appendix C to Part 67—Computer Program Note...

49 CFR Appendix C to Part 385 - Regulations Pertaining to Remedial Directives in Part 385, Subpart J

Code of Federal Regulations, 2011 CFR

2011-10-01

... Part 385, Subpart J C Appendix C to Part 385 Transportation Other Regulations Relating to... MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Pt. 385, App. C Appendix C to Part 385.... § 395.3(c)(1)Requiring or permitting a property-carrying commercial motor vehicle driver to restart a...

49 CFR Appendix C to Part 385 - Regulations Pertaining to Remedial Directives in Part 385, Subpart J

Code of Federal Regulations, 2010 CFR

2010-10-01

... Part 385, Subpart J C Appendix C to Part 385 Transportation Other Regulations Relating to... MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Pt. 385, App. C Appendix C to Part 385.... § 395.3(c)(1)Requiring or permitting a property-carrying commercial motor vehicle driver to restart a...

The two-way relationship between ionospheric outflow and the ring current

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

Welling, Daniel T.; Jordanova, Vania Koleva; Glocer, Alex

It is now well established that the ionosphere, because it acts as a significant source of plasma, plays a critical role in ring current dynamics. However, because the ring current deposits energy into the ionosphere, the inverse may also be true: the ring current can play a critical role in the dynamics of ionospheric outflow. This study uses a set of coupled, first-principles-based numerical models to test the dependence of ionospheric outflow on ring current-driven region 2 field-aligned currents (FACs). A moderate magnetospheric storm event is modeled with the Space Weather Modeling Framework using a global MHD code (Block Adaptivemore » Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), a polar wind model (Polar Wind Outflow Model), and a bounce-averaged kinetic ring current model (ring current atmosphere interaction model with self-consistent magnetic field, RAM-SCB). Initially, each code is two-way coupled to all others except for RAM-SCB, which receives inputs from the other models but is not allowed to feed back pressure into the MHD model. The simulation is repeated with pressure coupling activated, which drives strong pressure gradients and region 2 FACs in BATS-R-US. It is found that the region 2 FACs increase heavy ion outflow by up to 6 times over the non-coupled results. The additional outflow further energizes the ring current, establishing an ionosphere-magnetosphere mass feedback loop. This study further demonstrates that ionospheric outflow is not merely a plasma source for the magnetosphere but an integral part in the nonlinear ionosphere-magnetosphere-ring current system.« less

The two-way relationship between ionospheric outflow and the ring current

DOE PAGES

Welling, Daniel T.; Jordanova, Vania Koleva; Glocer, Alex; ...

2015-06-01

It is now well established that the ionosphere, because it acts as a significant source of plasma, plays a critical role in ring current dynamics. However, because the ring current deposits energy into the ionosphere, the inverse may also be true: the ring current can play a critical role in the dynamics of ionospheric outflow. This study uses a set of coupled, first-principles-based numerical models to test the dependence of ionospheric outflow on ring current-driven region 2 field-aligned currents (FACs). A moderate magnetospheric storm event is modeled with the Space Weather Modeling Framework using a global MHD code (Block Adaptivemore » Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), a polar wind model (Polar Wind Outflow Model), and a bounce-averaged kinetic ring current model (ring current atmosphere interaction model with self-consistent magnetic field, RAM-SCB). Initially, each code is two-way coupled to all others except for RAM-SCB, which receives inputs from the other models but is not allowed to feed back pressure into the MHD model. The simulation is repeated with pressure coupling activated, which drives strong pressure gradients and region 2 FACs in BATS-R-US. It is found that the region 2 FACs increase heavy ion outflow by up to 6 times over the non-coupled results. The additional outflow further energizes the ring current, establishing an ionosphere-magnetosphere mass feedback loop. This study further demonstrates that ionospheric outflow is not merely a plasma source for the magnetosphere but an integral part in the nonlinear ionosphere-magnetosphere-ring current system.« less

D-seco-Vitamin D analogs having reversed configurations at C-13 and C-14: Synthesis, docking studies and biological evaluation.

PubMed

Szybinski, Marcin; Sokolowska, Katarzyna; Sicinski, Rafal R; Plum, Lori A; DeLuca, Hector F

2017-10-01

Prompted by results of molecular modeling performed on the seco-d-ring-vitamins D, we turned our attention to such analogs, having reversed configurations at C-13 and C-14, as the next goals of our studies on the structure-activity relationship for vitamin D compounds. First, we developed an efficient total synthesis of the "upper" C/seco-d-ring fragment with a 7-carbon side chain. Then, we coupled it with A-ring fragments using Sonogashira or Wittig-Horner protocol, providing the targeted D-seco analogs of 1α,25-dihydroxyvitamin D 3 and 1α,25-dihydroxy-19-norvitamin D 3 possessing a vinyl substituent at C-14 and a double bond between C-17 and C-20. The affinities of the synthesized vitamin D analogs to the full-length recombinant rat VDR were examined, as well as their differentiating and transcriptional activities. In these in vitro tests, they were significantly less active compared to 1α,25-(OH) 2 D 3 . Moreover, it was established that the analogs tested in vivo in rats showed no calcemic potency. Copyright © 2016 Elsevier Ltd. All rights reserved.

An Electron-Diffraction Examination of Cast-Iron Piston Rings from Single-Cylinder Aircraft-Engine Tests

DTIC Science & Technology

1945-02-01

found t; a great extent on thn ueed cylinder barrel ( SAE 4140 steel) and to a lesser extent on the top ohrmne- plated ring of the aesembl.yafter it had...on the used cylinder barrel (W 4140 steel) used in the tests and, to a lesser extent, on the used top chrome-platedring of the piston assembly. The

Rheology modification with ring polymers

NASA Astrophysics Data System (ADS)

Vlassopoulos, Dimitris

It is now established that experimental unconcatenated ring polymers can be purified effectively by means of fractionation at the critical condition. For molecular weights well above the entanglement threshold, purified rings relax stress via power-law (with an exponent of about -0.4), sharply departing from their linear counterparts. Experimental results are in harmony with modeling predictions and simulations. Here, we present results from recent interdisciplinary efforts and discuss two challenges: (i) the nonlinear shear rheology of purified ring melts is also very different from that of unlinked chains. Whereas the latter exhibit features that can be explained, to a first approach, in the framework in the tube model, the former behave akin to unentangled chains with finite extensibility and exhibit much small deformation at steady state. (ii) blends of rings and linear polymers exhibit unique features in different regimes: The addition of minute amounts of linear chains drastically affects ring dynamics. This relates to ring purity and the ability of unlinked linear chains to thread rings. With the help of simulations, it is possible to rationalize the observed surprisingly slow viscoelastic relaxation, which is attributed to ring-linear and ring-ring penetrations. On the other hand, adding small amounts of rings to linear polymers of different molecular weights influences their linear and nonlinear rheology in an unprecedented way. The blend viscosity exceeds that of the slower component (linear) in this non-interacting mixture, and its dependencies on composition and molecular weight ratio are examined, whereas the role of molecular architecture is also addressed. Consequently, closing the ends of a linear chain can serve as a powerful means for molecular manipulation of its rheology. This presentation reflects collaborative efforts with S. Costanzo, Z-C. Yan, R. Pasquino, M. Kaliva, S. Kamble, Y. Jeong, P. Lutz, J. Allgaier, T. Chang, D. Talikis, V

Propeller Churns the A Ring

NASA Image and Video Library

2010-07-08

This image is part of a set of images obtained by NASA Cassini spacecraft showing a propeller-shaped structure created by a hidden, embedded moon moving through one of Saturn rings. An animation is available at the Photojournal.

32 CFR Appendix C to Part 86 - State Information

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 1 2014-07-01 2014-07-01 false State Information C Appendix C to Part 86 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN CRIMINAL HISTORY BACKGROUND CHECKS ON INDIVIDUALS IN CHILD CARE SERVICES Pt. 86, App. C Appendix C to Part...

32 CFR Appendix C to Part 86 - State Information

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 1 2013-07-01 2013-07-01 false State Information C Appendix C to Part 86 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN CRIMINAL HISTORY BACKGROUND CHECKS ON INDIVIDUALS IN CHILD CARE SERVICES Pt. 86, App. C Appendix C to Part...

32 CFR Appendix C to Part 86 - State Information

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 1 2012-07-01 2012-07-01 false State Information C Appendix C to Part 86 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN CRIMINAL HISTORY BACKGROUND CHECKS ON INDIVIDUALS IN CHILD CARE SERVICES Pt. 86, App. C Appendix C to Part...

31 CFR Appendix C to Part 359 - Investment Considerations

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Investment Considerations C Appendix C to Part 359 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL..., SERIES I Pt. 359, App. C Appendix C to Part 359—Investment Considerations 1. What are some index...

31 CFR Appendix C to Part 359 - Investment Considerations

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Investment Considerations C Appendix C to Part 359 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... BONDS, SERIES I Pt. 359, App. C Appendix C to Part 359—Investment Considerations 1. What are some index...

31 CFR Appendix C to Part 359 - Investment Considerations

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Investment Considerations C Appendix C to Part 359 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... BONDS, SERIES I Pt. 359, App. C Appendix C to Part 359—Investment Considerations 1. What are some index...

A close look at Saturn's rings with Cassini VIMS

USGS Publications Warehouse

Nicholson, P.D.; Hedman, M.M.; Clark, R.N.; Showalter, M.R.; Cruikshank, D.P.; Cuzzi, J.N.; Filacchione, G.; Capaccioni, F.; Cerroni, P.; Hansen, G.B.; Sicardy, B.; Drossart, P.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Coradini, A.

2008-01-01

Soon after the Cassini-Huygens spacecraft entered orbit about Saturn on 1 July 2004, its Visual and Infrared Mapping Spectrometer obtained two continuous spectral scans across the rings, covering the wavelength range 0.35-5.1 ??m, at a spatial resolution of 15-25 km. The first scan covers the outer C and inner B rings, while the second covers the Cassini Division and the entire A ring. Comparisons of the VIMS radial reflectance profile at 1.08 ??m with similar profiles at a wavelength of 0.45 ??m assembled from Voyager images show very little change in ring structure over the intervening 24 years, with the exception of a few features already known to be noncircular. A model for single-scattering by a classical, many-particle-thick slab of material with normal optical depths derived from the Voyager photopolarimeter stellar occultation is found to provide an excellent fit to the observed VIMS reflectance profiles for the C ring and Cassini Division, and an acceptable fit for the inner B ring. The A ring deviates significantly from such a model, consistent with previous suggestions that this region may be closer to a monolayer. An additional complication here is the azimuthally-variable average optical depth associated with "self-gravity wakes" in this region and the fact that much of the A ring may be a mixture of almost opaque wakes and relatively transparent interwake zones. Consistently with previous studies, we find that the near-infrared spectra of all main ring regions are dominated by water ice, with a typical regolith grain radius of 5-20 ??m, while the steep decrease in visual reflectance shortward of 0.6 ??m is suggestive of an organic contaminant, perhaps tholin-like. Although no materials other than H2O ice have been identified with any certainty in the VIMS spectra of the rings, significant radial variations are seen in the strength of the water-ice absorption bands. Across the boundary between the C and B rings, over a radial range of ???7000 km, the

Thermal Rate Coefficients for the Astrochemical Process C + CH+ → C2+ + H by Ring Polymer Molecular Dynamics.

PubMed

Rampino, Sergio; Suleimanov, Yury V

2016-12-22

Thermal rate coefficients for the astrochemical reaction C + CH + → C 2 + + H were computed in the temperature range 20-300 K by using novel rate theory based on ring polymer molecular dynamics (RPMD) on a recently published bond-order based potential energy surface and compared with previous Langevin capture model (LCM) and quasi-classical trajectory (QCT) calculations. Results show that there is a significant discrepancy between the RPMD rate coefficients and the previous theoretical results that can lead to overestimation of the rate coefficients for the title reaction by several orders of magnitude at very low temperatures. We argue that this can be attributed to a very challenging energy profile along the reaction coordinate for the title reaction, not taken into account in extenso by either the LCM or QCT approximation. In the absence of any rigorous quantum mechanical or experimental results, the computed RPMD rate coefficients represent state-of-the-art estimates to be included in astrochemical databases and kinetic networks.

VpRFP1, a novel C4C4-type RING finger protein gene from Chinese wild Vitis pseudoreticulata, functions as a transcriptional activator in defence response of grapevine

PubMed Central

Yu, Yihe; Xu, Weirong; Wang, Shengyi; Xu, Yan; Li, Hui'e; Wang, Yuejin; Li, Shuxiu

2011-01-01

RING finger proteins comprise a large family and play important roles in regulation of growth and development, hormone signalling, and responses to biotic and abiotic stresses in plants. In this study, the identification and functional characterization of a C4C4-type RING finger protein gene from the Chinese wild grapevine Vitis pseudoreticulata (designated VpRFP1) are reported. VpRFP1 was initially identified as an expressed sequence tag (EST) from a cDNA library constructed from leaves of V. pseudoreticulata inoculated with the grapevine powdery mildew Uncinula necator. Sequence analysis of the deduced VpRFP1 protein based on the full-length cDNA revealed an N-terminal nuclear localization signal (NLS) and a C-terminal C4C4-type RING finger motif with the consensus sequence Cys-X2-Cys-X13-Cys-X1-Cys-X4-Cys-X2-Cys-X10-Cys-X2-Cys. Upon inoculation with U. necator, expression of VpRFP1 was rapidly induced to higher levels in mildew-resistant V. pseudoreticulata plants. In contrast, expression of VpRFP1 was down-regulated in mildew-susceptible V. vinifera plants. Western blotting using an antibody raised against VpRFP1 showed that VpRFP1 was also induced to higher levels in V. pseudoreticulata plants at 12–48 hours post-inoculation (hpi). However, there was only slight increase in VpRFP in V. vinifera plants in the same time frame, even though a more significant increase was observed at 96–144 hpi in these plants. Results from transactivation assays in yeast showed that the RING finger motif of VpRFP1 exhibited some activity of transcriptional activation; however, no activity was seen with the full-length VpRFP1. Overexpression of VpRFP1 in Arabidopsis plants was found to enhance resistance to Arabidopsis powdery mildew Golovinomyces cichoracearum, which seemed to be correlated with increased transcript levels of AtPR1 and AtPR2 in the pathogen-infected tissues. In addition, the Arabidopsis transgenic lines showed enhanced resistance to a virulent bacterial

Ring lens focusing and push-pull tracking scheme for optical disk systems

NASA Technical Reports Server (NTRS)

Gerber, R.; Zambuto, J.; Erwin, J. K.; Mansuripur, M.

1993-01-01

An experimental comparison of the ring lens and the astigmatic techniques of generating focus-error-signal (FES) in optical disk systems reveals that the ring lens generates a FES over two times steeper than that produced by the astigmat. Partly due to this large slope and, in part, because of its diffraction-limited behavior, the ring lens scheme exhibits superior performance characteristics. In particular the undesirable signal known as 'feedthrough' (induced on the FES by track-crossings during the seek operation) is lower by a factor of six compared to that observed with the astigmatic method. The ring lens is easy to align and has reasonable tolerance for positioning errors.

40 CFR Appendixes C-G to Part 80 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false [Reserved] C Appendixes C-G to Part 80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Appendixes C-G to Part 80 [Reserved] ...

40 CFR Appendixes C-G to Part 80 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false [Reserved] C Appendixes C-G to Part 80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Appendixes C-G to Part 80 [Reserved] ...

1. TEST AREA 1115, SOUTH PART OF SUPPORT COMPLEX, LOOKING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. TEST AREA 1-115, SOUTH PART OF SUPPORT COMPLEX, LOOKING TO EAST FROM ABOVE BUILDING 8655, THE FUEL STORAGE TANK FARM, IN FOREGROUND SHADOW. AT THE RIGHT IS BUILDING 8660, ELECTRICAL SUBSTATION; TO ITS LEFT IS BUILDING 8663, THE HELIUM COMPRESSION PLANT. THE LIGHT TONED STRUCTURE IN THE MIDDLE DISTANCE, CENTER, IS THE MACHINE SHOP FOR TEST STAND 1-3. IN THE FAR DISTANCE IS TEST STAND 1-A, WITH THE WHITE SPHERICAL TANKS, AND TEST STAND 2-A TO ITS RIGHT. ALONG THE HORIZON FROM FAR LEFT ARE TEST STAND 1-D, TEST STAND 1-C, WATER TANKS ABOVE TEST AREA 1-125, AND TEST STAND 1-B IN TEST AREA 1-120. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Leuhman Ridge near Highways 58 & 395, Boron, Kern County, CA

40 CFR Figure C-1 to Subpart C of... - Suggested Format for Reporting Test Results for Methods for SO 2, CO, O 3, NO 2

Code of Federal Regulations, 2011 CFR

2011-07-01

... Results for Methods for SO 2, CO, O 3, NO 2 C Figure C-1 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Fig. C-1 Figure C-1 to Subpart C of Part 53—Suggested Format for Reporting Test... Difference Table C-1 spec. Pass or fail Low 1 ____ ppm 2 to ____ ppm 3 4 5 6 Medium 1 ____ ppm 2 to ____ ppm...

40 CFR Figure C-1 to Subpart C of... - Suggested Format for Reporting Test Results for Methods for SO 2, CO, O 3, NO 2

Code of Federal Regulations, 2014 CFR

2014-07-01

... Results for Methods for SO 2, CO, O 3, NO 2 C Figure C-1 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Fig. C-1 Figure C-1 to Subpart C of Part 53—Suggested Format for Reporting Test... Difference Table C-1 spec. Pass or fail Low 1 ____ ppm 2 to ____ ppm 3 4 5 6 Medium 1 ____ ppm 2 to ____ ppm...

40 CFR Figure C-1 to Subpart C of... - Suggested Format for Reporting Test Results for Methods for SO 2, CO, O 3, NO 2

Code of Federal Regulations, 2012 CFR

2012-07-01