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1

Evaluation of (4)I(15/2) and (4)I(13/2) Stark-level energies in erbium-doped aluminosilicate glass fibers.  

PubMed

Spectroscopic measurements of fluorescence and absorption in an erbium-doped fiber permit the evaluation of the Stark-level energies of the (4)I(15/2) and (4)I(13/2) manifolds in Er:glass. The data permit the allocation of the individual laser transitions associated with the room-temperature gain spectrum of erbium-doped fiber amplifiers operating near lambda = 1.53 microm. PMID:19768003

Desurvire, E; Simpson, J R

1990-05-15

2

Multiple Doped Erbium Laser Materials.  

National Technical Information Service (NTIS)

The goal under this contract is to develop erbium doped laser glasses whose performance characteristics exceed those of previously developed erbium doped materials. One approach is to optimize the laser rod configuration. The effect of laser rod length on...

R. F. Woodcock

1973-01-01

3

Multiple Doped Erbium Laser Materials.  

National Technical Information Service (NTIS)

The goal to be attained under this contract is to develop erbium doped laser glasses whose performance characteristics exceed those of previously developed erbium doped materials. One phase of the program is to optimize the laser rod configuration. The ef...

R. F. Woodcock

1973-01-01

4

Characterization and light emission from Erbium Oxide Nanoparticles  

NASA Astrophysics Data System (ADS)

The present work reports light emission from Erbium Oxide nanoparticles. The nanoparticles, with 43 nm diameter, were obtained in the form of nanopowder with 99.9% purity. These nanoparticles were characterized for their light emission under a 532 nm Nd:YAG laser excitation. A Photoluminescence (PL) system was used to detect fluorescence emission from the nanoparticles. The PL system consisted of Pixis brand CCD camera with a range of 300 to 2000 nm. The Erbium Oxide nanoparticles were also mixed in distilled water to obtain spectrum. Two emission peaks were observed at 554 nm and 813 nm. The green emission at 554nm was obtained as a result of ^4I15/2-> ^4S3/2 transition, and the near infrared emission from ^4I15/2-> ^4I13/2 transition. The process was also repeated in vacuum and it was found that the green emission enhances tremendously when the nanoparticles are excited in vacuum. This enhanced luminescence from the Erbium Oxide nanoparticles shows their potential importance in the optical devices and Biomedical applications.

Maqbool, Muhammad; Wilkinson, Lynda; Ahmad, Iftikhar

2013-03-01

5

Erbium hydride decomposition kinetics.  

SciTech Connect

Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report are analyzed quantitatively using Redhead's method to yield kinetic parameters (E{sub A} {approx} 54.2 kcal/mol), which are then utilized to predict hydrogen outgassing in vacuum for a variety of thermal treatments. Interestingly, it was found that the activation energy for desorption can vary by more than 7 kcal/mol (0.30 eV) for seemingly similar samples. In addition, small amounts of less-stable hydrogen were observed for all erbium dihydride films. A detailed explanation of several approaches for analyzing thermal desorption spectra to obtain kinetic information is included as an appendix.

Ferrizz, Robert Matthew

2006-11-01

6

Real-time synchrotoron radiation X-ray diffraction and abnormal temperature dependence of photoluminescence from erbium silicates on SiO{sub 2}/Si substrates  

SciTech Connect

The erbium silicate formation processes during annealing in Ar gas were monitored by synchrotron radiation grazing incidence X-ray diffraction (GIXD) in real time and the optical properties of the silicates were investigated by photoluminescence measurements in spectral and time-resolved domains. The GIXD measurements show that erbium silicates and erbium oxide are formed by interface reactions between silicon oxide and erbium oxides deposited on silicon oxide by reactive sputtering in Ar gas and O{sub 2}/Ar mixture gas ambiences. The erbium silicates are formed above 1060 degree sign C in Ar gas ambience and above 1010 degree sign C in O{sub 2}/Ar gas ambience, and erbium silicides are dominantly formed above 1250 degree sign C. The I{sub 15/2}-I{sub 13/2} Er{sup 3+} photoluminescence from the erbium oxide and erbium silicate exhibits abnormal temperature dependence, which can be explained by the phonon-assisted resonant absorption of the 532-nm excitation photons into the {sup 2}H{sub 11/2} levels of Er{sup 3+} ions of the erbium compounds.

Omi, H.; Tawara, T.; Tateishi, M. [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato- Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

2012-03-15

7

Optical Pumps for Erbium Lasers.  

National Technical Information Service (NTIS)

The overall objective is to produce more efficient pulsed optical pumps for erbium lasers. Both xenon and alkali-metal vapor lamps are being studied. Laser materials both glass and YAG were selected and their absorption and excitation spectra determined. ...

L. Noble

1971-01-01

8

Interaction of Thin Erbium Films with Aluminum.  

National Technical Information Service (NTIS)

Aluminum is a potential substrate to support thin erbium films used for high-temperature, hydrogen isotope storage. Both aluminum and erbium are reactive metals, and the interaction of the two could make for an unstable combination at elevated temperature...

D. M. Holloway E. P. Boespflug J. L. Provo J. M. Harris

1984-01-01

9

Light emission and luminescence enhancement in Erbium Oxide nanoparticles  

NASA Astrophysics Data System (ADS)

We reports light emission from Erbium Oxide nanoparticles. The nanoparticles, with 45 nm diameter, were obtained in the form of nanopowder. These nanoparticles were characterized for light emission under a 30 mW, 532 nm Nd:YAG laser excitation and a Photoluminescence (PL) system, made by Princeton Instrumentation, with a Pixis brand CCD camera. The nanoparticles were stick on a scotch tape and placed in the PL system. Spectrum of the light emitted from the nanoparticles was obtained and analyzed after subtracting the background spectrum. Two emission peaks were observed around 554 nm and 820 nm. The green emission at 554 nm was obtained as a result of ^2H11/2 ->^4I15/2 transition, and the near infrared emission from ^4I9/2->^4I15/2 transition. The process was also repeated in vacuum and it was found that the green emission enhances tremendously, showing the importance of Erbium Oxide nanoparticles optical and biophotonics applications.

Wilkinson, Lynda; Maqbool, Muhammad; Ahmad, Iftikhar

2011-10-01

10

Modeling erbium-doped fiber amplifiers  

Microsoft Academic Search

Erbium-doped fiber amplifiers are modeled using the propagation and rate equations of a homogeneous two-level laser medium. Numerical methods are used to analyze the effects of optical modes and erbium confinement on amplifier performance, and to calculate both the gain and amplified spontaneous emission (ASE) spectra. Fibers with confined erbium doping are completely characterized from easily measured parameters: the ratio

C. Randy Giles; Emmanuel Desurvire

1991-01-01

11

Evidence for erbium-erbium energy migration in erbium(III) bis(perfluoro-p-tolyl)phosphinate  

NASA Astrophysics Data System (ADS)

Photoluminescence lifetime measurements of the erbium decay in samples of erbium(III) bis(perfluoro-p-tolyl)phosphinate, Er[(p-CF3C6F4)2PO2]3, as a function of erbium concentration have been made. It has been found that for concentrations greater than 50%, the lifetime could be fitted with a stretched exponential function, which is indicative of erbium-erbium energy migration to quenching sites, most likely at the surface of the finely divided powder. At concentrations below 50%, the decay was single exponential with a maximum lifetime of ~700 ?s.

Tan, R. H. C.; Pearson, J. M.; Zheng, Y.; Wyatt, P. B.; Gillin, W. P.

2008-03-01

12

19 CFR 152.105 - Deductive value.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Deductive value. 152.105 Section 152.105 Customs...Merchandise § 152.105 Deductive value. (a) Merchandise concerned. For the purposes of deductive value, âmerchandise concernedâ means...

2013-04-01

13

25 CFR 152.1 - Definitions.  

Code of Federal Regulations, 2011 CFR

... 152.1 Section 152.1 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS § 152.1...

2011-04-01

14

Luminescence and non-linear optical properties of erbium-tetraphenylprophyrin complexes incorporated within a silica matrix by a sol-gel process  

NASA Astrophysics Data System (ADS)

A simplified method of synthesis and purification of Erbium-Tetraphenylporphyrin (ErTpp) complexes, and their incorporation within a silica gel by the sol-gel process, is presented. On the basis of optical spectroscopic measurements in the UV-VIS range it was found that in ErTpp complexes the tetraphenylporphyrin molecule served as a protective screen for erbium ions. The half-width of the erbium ion luminescence band for the 4S 3/2 ? 4I 15/2 transition was narrower by a factor of 5-6 in the new material than the corresponding value in erbium doped glasses or glass ceramics. It was shown that the value of the nonlinear refraction coefficient in ErTpp gels could considerably exceed that of silica glasses.

Clark, A.; Terpugov, V.; Medrano, F.; Cervantes, M.; Soto, D.

1999-12-01

15

Optical properties of organic semiconductors based on erbium phthalocyanine complexes in the mid- and near-infrared spectral regions  

SciTech Connect

The transmittance spectra of erbium phthalocyanine complexes in the mid- and near-infrared wavelength regions are studied. A detailed identification of the transmittance lines is presented for three types of phthalocyanine complexes. Data on the absorption of electromagnetic radiation at the wavelengths around 1.5 {mu}m due to the {sup 4}I{sub 13/2} {sup {yields}} {sup 4}I{sub 15/2} intracenter transitions between the levels of the erbium ions incorporated into the samples are obtained. It is found that some of the mid-infrared absorption lines shift when the number of organic ligands is increased by a factor of 2 or 3. It is shown that the absorption coefficient at the wavelengths around 1.5 {mu}m is equal to 27.5, 32.5, and 74 cm{sup -1} for erbium monophthalocyanine, bisphthalocyanine, and triphthalocyanine, respectively.

Belogorokhov, I. A., E-mail: jugqwerty@mail.ru; Tikhonov, E. V.; Breusova, M. O.; Pushkarev, V. E.; Tomilova, L. G.; Khokhlov, D. R. [Moscow State University (Russian Federation)

2007-10-15

16

25 CFR 152.26 - Advertisement.  

Code of Federal Regulations, 2011 CFR

...152.26 Section 152.26 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

17

25 CFR 152.24 - Appraisal.  

Code of Federal Regulations, 2011 CFR

...152.24 Section 152.24 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

18

40 CFR 152.1 - Scope.  

Code of Federal Regulations, 2013 CFR

...products under FIFRA section 3, including plant-incorporated protectants (PIPs). Unless specifically superseded by part 174, the regulations in part 152 apply to PIPs. (b) Part 152 also describes associated regulatory activities...

2013-07-01

19

37 CFR 1.152 - Design drawings.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Design drawings. 1.152 Section...UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL...National Processing Provisions Design Patents § 1.152 Design drawings. The...

2013-07-01

20

Tensimetric investigation of erbium polysulfide  

SciTech Connect

It is established that under the experimental conditions a single polysulfide phase Er/sub 7/S/sub 13/ (ErS /SUB 1.85/ ) exists in the Er-S system. The vapor pressure during the dissociation of this phase and its thermodynamic properties are determined. It is shown that among a series of polysulfides, viz., Nd/sub 7/S/sub 13/, Gd/sub 7/S/sub 13/, and Er/sub 7/S/sub 13/, the thermal stability is a minimum for erbium polysulfide.

Vasil'eva, I.G.; Gorbunova, L.G.

1986-11-01

21

Spectral gain hole-burning at 1.53 ?m in erbium-doped fiber amplifiers  

Microsoft Academic Search

Spectral gain hole-burning at ?0=1.53 ?m was observed in an erbium-doped fiber amplifier at temperatures between 4.2 and 77 K. The hole width was found to broaden with temperature for T ⩾20 K according to a T1.73 law. From the data, the room-temperature homogeneous linewidth associated with the 1.531-?m transition in the 4I13\\/2-4I15\\/2 laser system was determined to be ??h=11.5

E. Desurvire; J. L. Zyskind; J. R. Simpson

1990-01-01

22

Fabrication and properties of erbium oxide  

SciTech Connect

Erbium oxide (Er{sub 2}O{sub 3}) is a rare earth oxide of interest because of its chemical and thermal stability and high melting point, 2,430 C. However, there is relatively little information available regarding the relation between the structure and the mechanical properties of this material. A densification study of polycrystalline erbium oxide powders is reported here. Erbium oxide pellets were uniaxially pressed (40--280 MPa) and sintered (1,500--1,800 C) in order to obtain density data for as-received commercial powders. In addition, the particle size and distribution of as-received powders were varied by milling and the effects on densification were studied. The powders were characterized for particle size, phase and impurity content and surface area. The mechanical properties of high density sintered erbium oxide bodies were characterized using indentation hardness and toughness as a function of temperature and microstructure. Relations between the microstructure and mechanical properties are described.

Neuman, A.; Platero, M.; Romero, R.; McClellan, K.J.; Petrovic, J.J.

1997-03-01

23

Erbium-doped aluminophosphosilicate optical fibres  

SciTech Connect

We have studied the active properties of erbium-doped aluminophosphosilicate (APS) core fibres in wide ranges of erbia, alumina and phosphorus pentoxide concentrations. The absorption and luminescence spectra of the P{sub 2}O{sub 5}- or Al{sub 2}O{sub 3}-enriched erbium-doped APS fibres are shown to be similar to those of the erbium-doped fibres singly doped with phosphorus pentoxide or alumina, respectively. The formation of AlPO{sub 4} in APS fibres leads not only to a reduction in the refractive index of the glass but also to a marked increase in Er{sub 2}O{sub 3} solubility in silica. (optical fibres)

Likhachev, M E; Bubnov, M M; Zotov, K V; Medvedkov, O I [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation); Lipatov, D S; Yashkov, M V; Gur'yanov, Aleksei N [Institute of Chemistry of High-Purity Substances, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

2010-09-10

24

Nuclear Data Sheets for A = 152  

NASA Astrophysics Data System (ADS)

Detailed level schemes, decay schemes, and the experimental data on which they are based are presented for all nuclei with mass number A=152. The experimental data are evaluated; inconsistencies and discrepancies are noted; and adopted values for level and ?-ray energies, ? intensities, as well as for other nuclear properties are given. This evaluation replaces the A=152 evaluation published by Agda Artna-Cohen in Nuclear Data Sheets 79, 1 (1996) and the evaluation for 152Dy prepared by Balraj Singh and published in Nuclear Data Sheets 95, 995 (2002).

Martin, M. J.

2013-11-01

25

44 CFR 152.9 - Reconsideration.  

Code of Federal Regulations, 2013 CFR

...HOMELAND SECURITY FIRE PREVENTION AND CONTROL ASSISTANCE TO FIREFIGHTERS GRANT PROGRAM § 152.9 Reconsideration. (a) Reconsideration...Administrator, Grant Programs Directorate, Assistance to Firefighters Grant Program, FEMA, 800 K Street, NW., South...

2013-10-01

26

40 CFR 141.152 - Effective dates.  

Code of Federal Regulations, 2013 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Consumer Confidence Reports § 141.152 Effective dates. (a) The regulations in this subpart shall take effect on September 18,...

2013-07-01

27

19 CFR 122.152 - Application.  

Code of Federal Regulations, 2013 CFR

...S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Flights to and From Cuba § 122.152 Application. This subpart applies to all aircraft entering or departing the U.S....

2013-04-01

28

34 CFR 300.152 - Minimum State complaint procedures.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Minimum State complaint procedures. 300.152 Section 300.152 Education... State Eligibility State Complaint Procedures § 300.152 Minimum State complaint procedures. (a) Time limit; minimum...

2013-07-01

29

19 CFR 152.25 - Conversion of foreign currency.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Conversion of foreign currency. 152.25 Section 152.25 Customs Duties... Appraisement § 152.25 Conversion of foreign currency. When foreign currency must be converted for purposes of...

2013-04-01

30

30 CFR 206.152 - Valuation standards-unprocessed gas.  

Code of Federal Regulations, 2010 CFR

... false Valuation standards-unprocessed gas. 206.152 Section 206.152 Mineral...REVENUE MANAGEMENT PRODUCT VALUATION Federal Gas § 206.152 Valuation standardsâunprocessed gas. (a)(1) This section applies to...

2009-07-01

31

30 CFR 1206.152 - Valuation standards-unprocessed gas.  

Code of Federal Regulations, 2013 CFR

... Valuation standards-unprocessed gas. 1206.152 Section 1206.152 Mineral Resources OFFICE OF NATURAL RESOURCES REVENUE, DEPARTMENT OF THE...REVENUE PRODUCT VALUATION Federal Gas § 1206.152 Valuation...

2013-07-01

32

Standing-wave monomode erbium fiber laser  

Microsoft Academic Search

An integrated standing-wave, single frequency, erbium fiber laser having a laser linewidth of less than 47 kHz is reported. The monolithic fiber laser incorporated two highly reflective intracore Bragg reflectors which provide both cavity feedback and adequate longitudinal mode discrimination. The narrow linewidth single-mode operation and monolithic construction may make this a valuable communications\\/sensor source.

G. A. Ball; W. W. Morey; W. H. Glenn

1991-01-01

33

Erbium hydride thermal desorption : controlling kinetics.  

SciTech Connect

Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report show that hydride film processing parameters directly impact thermal stability. Issues to be addressed include desorption kinetics for dihydrides and trihydrides, and the effect of film growth parameters, loading parameters, and substrate selection on desorption kinetics.

Ferrizz, Robert Matthew

2007-08-01

34

Erbium-doped fiber amplifiers: linear approximations  

Microsoft Academic Search

In this paper, we show that there is a simple linear model for an erbium-doped fiber amplifier. Specifically, we show that the amplifier gain, raised to a wavelength-dependent power, is strongly linear with respect to the amplifier-induced increase in signal power

I. M. I. Habbab; A. A. M. Saleh; P. K. Runge

1995-01-01

35

Resonantly pumped, erbium-doped, GSGG, 2.8 micron, solid state laser with energy recycling and high slope efficiency  

NASA Astrophysics Data System (ADS)

This invention is a laser system and method for producing a laser emission at a wavelength of substantially 2.8 microns and having a quantum efficiency of at least unity and a slope efficiency of about 36%. In a preferred embodiment of the invention, the laser system comprises a laser cavity defined by first and second reflective elements with one of the reflective elements operating as an output coupler; a crystal disposed in the laser cavity and having a GSGG host material doped with a preselected percent concentration of erbium, the GSGG host material and preselected percent concentration of erbium being selected so as to provide a quantum efficiency of at least unity by the 4I13/2 + 4I13/2 right arrow 4I9/2 + 4I15/2 upconversion process and a slope efficiency of about 36% when the crystal is resonantly pumped; and a resonant pump laser for directly pumping the 4I11/2 upper laser state of the erbium with a pump beam to cause the crystal to produce a laser emission corresponding to the 4I11/2 right arrow 4I13/2 laser transition having a wavelength of substantially 2.8 microns.

Esterowitz, Leon; Stoneman, Robert C.

1993-04-01

36

Resonantly pumped, erbium-doped, GSGG, 2.8 micron, solid state laser with energy recycling and high slope efficiency  

NASA Astrophysics Data System (ADS)

A laser system and a method for producing a laser emission at a wavelength of approximately 2.8 microns are presented. The system and method have a quantum efficiency of at least unity and a slope efficiency of about 36 percent. The laser system is comprised of the following: a laser cavity defined by first and second reflective elements with one of the reflective elements operating as an output coupler; a crystal disposed in the laser cavity and having a GSGG host material doped with a preselected percent concentration of erbium, the GSGG host material and preselected percent concentration of erbium being selected so as to provide a quantum efficiency of at least unity by the (sup 4)I(sub 13/2) + (sup 4)I(sub 13/2) yields (sup 4)I(sub9/2) + (sup 4)I(sub 15/2) upconversion process and a slope efficiency of about 36 percent when the crystal is resonantly pumped; and a resonant pump laser for directly pumping the (sup 4)I(sub 11/2) upper laser state of the erbium with a pump beam to cause the crystal to produce a laser emission corresponding to the (sup 4)I(sub 11/2) yields (sup 4)I(sub 13/2) laser transition having a wavelength of substantially 2.8 microns.

Esterowitz, Leon; Stoneman, Robert

1992-05-01

37

Fabrication and Optical Properties of Erbium-Doped Polymer Films  

Microsoft Academic Search

The crosslinked, fluorinated, patterned and erbium (Er) doped polymer films were fabricated by UV-curing after a simple spin-coating. Er-doped solutions containing Irgacure 819 used as a radical-type photoinitiator were prepared using erbium (III) trifluoromethane sulfonate as an erbium source, 2,2,3,3,4,4,5,5-octafluoropentyl acrylate as a fluorinated monomer, trimethylolpropane triacrylate and Ebecyl 810 resin as a crosslinking agent with various weight ratios. The

Wook Hyun Kim; Soo Chool Lee; Kee-Jeong Yang; Myung-Seok Choi; Eui Sang Yoo; Yoon Soo Han

2010-01-01

38

Erbium-based edge-pumped disk lasera  

NASA Astrophysics Data System (ADS)

We report on initial testing of an edge-pumped erbium-based disk laser operating at 1.53 micron. The laser uses a single laser disk having a composite glass construction with erbium-ytterbium co-doped center and undoped perimetral edge designed to channel pump light. Erbium is pumped to a laser transition by 940-nm diode radiation, which is first absorbed by ytterbium with subsequent energy transfer to erbium. This work presents results of initial testing of the laser with resonator optics configured for power extraction with two passes through the disk.

Vetrovec, John; Copeland, Drew A.; Litt, Amardeep S.; Du, Detao

2013-03-01

39

Absolute Measurement of exp 152 Eu.  

National Technical Information Service (NTIS)

A new method of the absolute measurement for exp 152 Eu was established based on the 4 pi beta - gamma spectroscopic anti-coincidence method. It is a coincidence counting method consisting of a 4 pi beta -counter and a Ge(Li) gamma -ray detector, in which...

H. Baba S. Baba S. Ichikawa T. Sekine I. Ishikawa

1981-01-01

40

Neutron Resonance Parameters for Gd-152 (Gadolinium)  

NASA Astrophysics Data System (ADS)

This document is part of the Supplement containing the complete sets of data of Volume 24 `Neutron Resonance Parameters' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides the neutron resonance parameters for the isotope Gd-152 (Gadolinium). Also included are spectra of direct gamma-rays from neutron resonance capture.

Sukhoruchkin, S. I.; Soroko, Z. N.

41

Neutron Resonance Parameters for Gd152 (Gadolinium)  

Microsoft Academic Search

This document is part of the Supplement containing the complete sets of data of Volume 24 `Neutron Resonance Parameters' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides the neutron resonance parameters for the isotope Gd-152 (Gadolinium). Also included are spectra of direct gamma-rays from neutron resonance capture.

S. I. Sukhoruchkin; Z. N. Soroko

2009-01-01

42

Third-order elastic constants of erbium  

Microsoft Academic Search

The third-order elastic constants (TOEC) of single-crystal erbium have been determined from measurements of selected uniaxial and hydrostatic pressure derivatives of the second-order elastic constants (SOEC). The changes in SOEC were measured using an ultrasonic sing around system capable of resolution of ±2 parts in 106 for changes in acoustic velocity. Values for the TOEC are in fair agreement with

D. C. Jiles; S. B. Palmer

1981-01-01

43

Characterization of the surface changes during the activation of erbium/erbium oxide for hydrogen storage.  

SciTech Connect

Erbium is known to effectively load with hydrogen when held at high temperature in a hydrogen atmosphere. To make the storage of hydrogen kinetically feasible, a thermal activation step is required. Activation is a routine practice, but very little is known about the physical, chemical, and/or electronic processes that occur during Activation. This work presents in situ characterization of erbium Activation using variable energy photoelectron spectroscopy at various stages of the Activation process. Modification of the passive surface oxide plays a significant role in Activation. The chemical and electronic changes observed from core-level and valence band spectra will be discussed along with corroborating ion scattering spectroscopy measurements.

Zavadil, Kevin Robert; Snow, Clark Sheldon; Brumbach, Michael Todd

2010-09-01

44

Synoviorthesis with erbium-169: a double-blind controlled comparison of erbium-169 with corticosteroid  

Microsoft Academic Search

Intra-articular injections of erbium--169 citrate and methylprednisolone acetate in hand joints were compared in a randomly selected double-blind trial. The patients included 21 with rheumatoid arthritis and 3 with psoriatic arthritis, and the design was an intrapatient comparison. No difference between joints treated with the radioisotope or steroid was observed in the year following injection.

J M Gumpel; S A Matthews; M Fisher

1979-01-01

45

Synoviorthesis with erbium-169: a double-blind controlled comparison of erbium-169 with corticosteroid.  

PubMed

Intra-articular injections of erbium--169 citrate and methylprednisolone acetate in hand joints were compared in a randomly selected double-blind trial. The patients included 21 with rheumatoid arthritis and 3 with psoriatic arthritis, and the design was an intrapatient comparison. No difference between joints treated with the radioisotope or steroid was observed in the year following injection. PMID:386961

Gumpel, J M; Matthews, S A; Fisher, M

1979-08-01

46

Synoviorthesis with erbium-169: a double-blind controlled comparison of erbium-169 with corticosteroid.  

PubMed Central

Intra-articular injections of erbium--169 citrate and methylprednisolone acetate in hand joints were compared in a randomly selected double-blind trial. The patients included 21 with rheumatoid arthritis and 3 with psoriatic arthritis, and the design was an intrapatient comparison. No difference between joints treated with the radioisotope or steroid was observed in the year following injection.

Gumpel, J M; Matthews, S A; Fisher, M

1979-01-01

47

44 CFR 152.6 - Application review and award process.  

Code of Federal Regulations, 2013 CFR

...Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY FIRE PREVENTION AND CONTROL ASSISTANCE TO FIREFIGHTERS GRANT PROGRAM § 152.6 Application review and award process. (a) As stated in § 152.5, we...

2013-10-01

48

44 CFR 16.152-16.159 - [Reserved  

Code of Federal Regulations, 2013 CFR

44 Emergency Management and Assistance 1 2013-10-01 2013-10-01...152-16.159 Section 16.152-16.159 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY...

2013-10-01

49

45 CFR 152.22 - Access to services.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Access to services. 152.22 Section 152.22 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS PRE-EXISTING CONDITION INSURANCE...

2010-10-01

50

25 CFR 152.31 - Cost of conveyance; payment.  

Code of Federal Regulations, 2011 CFR

...conveyance; payment. 152.31 Section 152.31 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS...

2011-04-01

51

25 CFR 152.32 - Irrigation fee; payment.  

Code of Federal Regulations, 2011 CFR

...Irrigation fee; payment. 152.32 Section 152.32 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS...

2011-04-01

52

14 CFR 152.111 - Application requirements: Airport development.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Application requirements: Airport development. 152.111 Section 152.111 Aeronautics...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS AIRPORT AID PROGRAM Eligibility Requirements and...

2009-01-01

53

14 CFR 152.111 - Application requirements: Airport development.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Application requirements: Airport development. 152.111 Section 152.111 Aeronautics...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS AIRPORT AID PROGRAM Eligibility Requirements and...

2010-01-01

54

14 CFR 152.113 - Application requirements: Airport planning.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Application requirements: Airport planning. 152.113 Section 152.113 Aeronautics...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS AIRPORT AID PROGRAM Eligibility Requirements and...

2010-01-01

55

14 CFR 152.325 - Financial status report: Airport planning.  

Code of Federal Regulations, 2010 CFR

... 2009-01-01 false Financial status report: Airport planning. 152.325 Section 152.325 Aeronautics...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS AIRPORT AID PROGRAM Accounting and Reporting...

2009-01-01

56

25 CFR 152.30 - Bidding by employees.  

Code of Federal Regulations, 2011 CFR

...152.30 Section 152.30 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

57

25 CFR 152.19 - Sale by fiduciaries.  

Code of Federal Regulations, 2011 CFR

...152.19 Section 152.19 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

58

25 CFR 152.27 - Procedure of sale.  

Code of Federal Regulations, 2011 CFR

...152.27 Section 152.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

59

Bose-Einstein condensation of erbium.  

PubMed

We report on the achievement of Bose-Einstein condensation of erbium atoms and on the observation of magnetic Feshbach resonances at low magnetic fields. By means of evaporative cooling in an optical dipole trap, we produce pure condensates of 168Er, containing up to 7×10(4) atoms. Feshbach spectroscopy reveals an extraordinary rich loss spectrum with six loss resonances already in a narrow magnetic-field range up to 3 G. Finally, we demonstrate the application of a low-field Feshbach resonance to produce a tunable dipolar Bose-Einstein condensate and we observe its characteristic d-wave collapse. PMID:23003221

Aikawa, K; Frisch, A; Mark, M; Baier, S; Rietzler, A; Grimm, R; Ferlaino, F

2012-05-25

60

20 Hz lamp pumped erbium glass laser  

NASA Astrophysics Data System (ADS)

Q-switched laser behavior of the new IRE RAS developed Yb-Er phosphate glass LGS-KhCh2 was studied using FTIR and water-cooled chamber with lamp pumping. Laser rod near 3 mm in diameter and 80 mm long was investigated. Laser output of 5-10 mJ was achieved at 1535 nm at 20 Hz repetition rate. For the first time, to our best knowledge, the CW operation of the erbium glass laser under lamp pumping is demonstrated.

Alekseev, N. E.; Byshevskaya-Konopko, L. O.; Izyneev, Anatoly A.; Kravchenko, Victor; Sadovski, P. I.

2004-04-01

61

40 CFR 152.99 - Petitions to cancel registration.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Petitions to cancel registration. 152.99 Section 152...Submitters' Rights § 152.99 Petitions to cancel registration. An original data submitter may petition the Agency to deny or cancel the registration of a product in...

2010-07-01

62

40 CFR 152.99 - Petitions to cancel registration.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 false Petitions to cancel registration. 152.99 Section 152...Submitters' Rights § 152.99 Petitions to cancel registration. An original data submitter may petition the Agency to deny or cancel the registration of a product in...

2009-07-01

63

40 CFR 152.86 - The cite-all method.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false The cite-all method. 152.86 Section 152.86 ...Submitters' Rights § 152.86 The cite-all method. An applicant may comply with this subpart by citing all data in Agency files that are...

2013-07-01

64

27 CFR 9.152 - Malibu-Newton Canyon.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Malibu-Newton Canyon. 9.152 Section 9.152...Viticultural Areas § 9.152 Malibu-Newton Canyon. (a) Name. The name of...described in this petition is âMalibu-Newton Canyon.â (b) Approved maps....

2010-04-01

65

27 CFR 9.152 - Malibu-Newton Canyon.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Malibu-Newton Canyon. 9.152 Section 9.152...Viticultural Areas § 9.152 Malibu-Newton Canyon. (a) Name. The name of...described in this petition is âMalibu-Newton Canyon.â (b) Approved maps....

2009-04-01

66

38 CFR 3.152 - Claims for death benefits.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Claims for death benefits. 3.152 Section 3.152...Compensation Claims § 3.152 Claims for death benefits. (a) A specific claim...3.153) must be filed in order for death benefits to be paid to any...

2013-07-01

67

42 CFR 84.152 - Breathing tube test; minimum requirements.  

Code of Federal Regulations, 2012 CFR

... 1 2012-10-01 2012-10-01 false Breathing tube test; minimum requirements. 84.152 Section 84.152 Public...DEVICES Supplied-Air Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type...

2012-10-01

68

Microstructural Features in Aged Erbium Tritide Foils  

SciTech Connect

Aged erbium tritide foil specimens are found to contain five distinctly different microstructural features. The general structure was of large columnar grains of ErT2. But on a fine scale, precipitates believed to be erbium oxy-tritides and helium bubbles could be identified. The precipitate size was in the range of ~10 nm and the bubbles were of an unusual planar shape on {111} planes with an invariant thickness of ~1 nm and a diameter on the order of 10 nm. Also, an outer layer containing no fine precipitate structure and only a few helium bubbles was present on foils. This layer is best described as a denuded zone which probably grew during aging in air. Finally, large embedded Er2O3 particles were found at low density and non-uniformly distributed, but sometimes extending through the thickness of the foil. A failure mechanism allowing the helium to escape is suggested by observed cracking between bubbles closer to end of life.

Gelles, David S.; Brewer, L. N.; Kotula, Paul G.; Cowgill, Donald F.; Busick, C. C.; Snow, C. S.

2008-01-01

69

Erbium triflate promoted multicomponent synthesis of highly substituted imidazoles.  

PubMed

The synthesis of highly substituted imidazole derivatives has been achieved from various ?-azido chalcones, aryl aldehydes, and anilines. This multicomponent protocol employs erbium triflate as a catalyst resulting in excellent yield of the imidazoles. PMID:24428260

Rajaguru, Kandasamy; Suresh, Rajendran; Mariappan, Arumugam; Muthusubramanian, Shanmugam; Bhuvanesh, Nattamai

2014-02-01

70

Erbium-Doped Fiber Amplifier Elements for Structural Analysis Sensors.  

National Technical Information Service (NTIS)

The use of erbium-doped fiber amplifiers (EDFA's) in optical fiber sensor systems for structural analysis is described. EDFA's were developed for primary applications as periodic regenerator amplifiers in long-distance fiber-based communication systems. T...

P. Hanna-hawver K. D. Kamdar S. Mehta S. Nagarajan M. H. Nasta

1992-01-01

71

Ultrashort Pulse Amplification in Erbium Doped Fibre Amplifiers.  

National Technical Information Service (NTIS)

Erbium-doped optical fibres displaying broad gain bandwidth centered at the wavelength of minimum loss and negative group velocity dispersion make almost the ideal media for generation and amplification femtosecond range optical pulses. Several authors ha...

D. V. J. Korobkin I. Y. Khruschev A. B. Grudinin E. M. Dianov

1992-01-01

72

Size control of erbium-doped silicon nanocrystals  

NASA Astrophysics Data System (ADS)

This work describes the effects of pyrolysis oven length and erbium precursor on the preparation of discrete erbium-doped silicon nanoparticles. These doped nanoparticles were prepared by the co-pyrolysis of disilane and the volatile complex Er(tmhd)3 (tmhd=2,2,6,6-tetramethyl-3,5-heptanedionato). The particle sizes and size distributions were determined using high resolution and conventional transmission electron microscopy. Erbium-doped silicon nanoparticles exhibit a selected area electron diffraction pattern consistent with the diamond cubic phase and a distinctive dark contrast in the transmission electron microscope. The presence of erbium is confirmed by x-ray energy dispersive spectroscopy. In general, the mean diameter of the individual nanoparticles increases as the length of the pyrolysis oven used during their preparation is increased.

John, John St.; Coffer, Jeffery L.; Chen, Yandong; Pinizzotto, Russell F.

2000-09-01

73

Cladding-pumped erbium-doped multicore fiber amplifier.  

PubMed

A cladding pumped multicore erbium-doped fiber amplifier for simultaneous amplification of 6 channels is demonstrated. Peak gain over 32 dB has been obtained at a wavelength of 1560 nm and the bandwidth measured at 20-dB gain was about 35 nm. Numerical modeling of cladding pumped multicore erbium-doped amplifier was also performed to study the properties of the amplifier. The results of experiment and simulation are found to be in good agreement. PMID:23037071

Abedin, K S; Taunay, T F; Fishteyn, M; DiGiovanni, D J; Supradeepa, V R; Fini, J M; Yan, M F; Zhu, B; Monberg, E M; Dimarcello, F V

2012-08-27

74

Erbium partitioning in a heavily doped transparent glass ceramic.  

PubMed

An erbium-doped transparent glass ceramic, consisting of LaF3 nanocrystallites with a characteristic length of approximately 20 nm embedded in an aluminosilicate glass matrix and exhibiting infrared-to-green up-conversion, has been studied. The degree of erbium partitioning into the nanocrystallite phase was found using energy transfer coefficients determined from bulk Er3+:LaF3 samples. This transparent glass ceramic sample was found to have a partitioning fraction of 19 +/- 5%. PMID:16127930

Jones, Gina C; Houde-Walter, S N

2005-08-15

75

Synthesis of erbium hydroxide microflowers and nanostructures in subcritical water  

Microsoft Academic Search

The effects of temperature, pressure, pH, residence time and reactant concentrations, as well as the presence or absence of CO2, on the size and morphology of erbium hydroxide particles synthesized in a hydrothermal batch reactor and a diamond-anvil cell (DAC) reactor have been investigated. Several new erbium-based microstructures and nanostructures were obtained that encompass different phases and shapes, including crystalline

H. Assaaoudi; Z. Fang; I. S. Butler; J. A. Kozinski

2008-01-01

76

Luminescence of erbium ions in tellurite glasses  

NASA Astrophysics Data System (ADS)

Optical characteristics of new generation of tellurite glasses having high stability against crystallization have been studied. As the initial reagents for the glasses synthesis on the base of tellurium oxide (TeO2) there were used such oxides as WO3, MoO3, La2O3, Li2CO3, ZnO—Bi2O2CO3 and active components such as high purity Er2O3, Yb2O3, ErF3 and YbF3. Intensities of luminescence at 1.53 µm of the erbium ions were determined after excitation at 975 nm. Experimental data obtained have shown the possibility to use the studied glasses doped by Er3+ and Yb3+ as active elements for fiber and integrated optics.

Savikin, Alexander P.; Grishin, Igor A.; Sharkov, Valery V.; Budruev, Andrei V.

2013-11-01

77

Quantifying and controlling the magnetic dipole contribution to 1.5-?m light emission in erbium-doped yttrium oxide  

NASA Astrophysics Data System (ADS)

We experimentally quantify the contribution of magnetic dipole (MD) transitions to the near-infrared light emission from trivalent erbium-doped yttrium oxide (Er3+:Y2O3). Using energy-momentum spectroscopy, we demonstrate that the 4I13/2?4I15/2 emission near 1.5 ?m originates from nearly equal contributions of electric dipole (ED) and MD transitions that exhibit distinct emission spectra. We then show how these distinct spectra, together with the differing local density of optical states for ED and MD transitions, can be leveraged to control Er3+ emission in structured environments. We demonstrate that far-field emission spectra can be tuned to resemble almost pure emission from either ED or MD transitions and show that the observed spectral modifications can be accurately predicted from the measured ED and MD intrinsic emission rates.

Li, Dongfang; Jiang, Mingming; Cueff, Sébastien; Dodson, Christopher M.; Karaveli, Sinan; Zia, Rashid

2014-04-01

78

Diode Pumped Erbium Cascade Fiber Lasers  

Microsoft Academic Search

Cascading the 4 I11\\/2 ? 4 I13\\/2 transition at 2.8 µm and 4 I13\\/2 ? 4 I15\\/2 transition at 1. 6 µm offers a solution to the thermal management of high power Er 3+ -doped fluoride fiber lasers. We demonstrate an output power of 8.2 W at 2.8 µm from an Er 3+ -doped fluorozirconate fiber laser with 56 W

Stuart D. Jackson; Markus Pollnau; Jianfeng Li

2011-01-01

79

Compact erbium lasers in the IR photorefractive keratectomy (PRK)  

NASA Astrophysics Data System (ADS)

Erbium lasers deliver laser radiation near 3 micrometers and are a promising alternative to excimer laser photorefractive keratectomy (UV-PRK). In addition to easier handling due to all solid state technology, especially when operated in the fundamental mode, IR-PRK eliminates the potential of mutagenic side effects associated with UV-PRK. However, a successful IR-PRK for the clinic treatment in the near future demands both technological development of erbium lasers in different operation modes and clinical investigation of interaction between 3 micrometers radiation and human corneas. The excellent cooperation between university, company and hospital makes this possible. Uncoated thin plates made from infrared materials were found to be effective etalon reflectors with high damage threshold as high as 1 GW/cm2 for erbium lasers. Four kinds of such reflectors were successfully tested in Q-switched Er:YAG-laser at 2.94 micrometers and Er:Cr:YSGG-laser at 2.80 micrometers. Very stable operation of our erbium lasers with high output energy both in free-running and Q-switched modes is realized. First infrared photorefractive keratectomy (IR-PRK) for myopic correction in human corneas by a free-running erbium laser based on our new construction concepts was achieved.

Liu, Baining; Eichler, Hans J.; Sperlich, O.; Holschbach, A.; Kayser, M.

1996-09-01

80

25 CFR 152.4 - Application for patent in fee.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Application for patent in fee. 152.4 Section 152.4...INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY...SALE OF CERTAIN INDIAN LANDS Issuing Patents in Fee, Certificates of Competency...

2011-04-01

81

25 CFR 152.32 - Irrigation fee; payment.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Irrigation fee; payment. 152.32 Section...Trust Or Restricted Lands § 152.32 Irrigation fee; payment. Collection of all...any Indian-owned lands within Indian irrigation projects is deferred as long...

2013-04-01

82

25 CFR 152.5 - Issuance of patent in fee.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Issuance of patent in fee. 152.5 Section 152.5...INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY...SALE OF CERTAIN INDIAN LANDS Issuing Patents in Fee, Certificates of Competency...

2010-04-01

83

25 CFR 152.5 - Issuance of patent in fee.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Issuance of patent in fee. 152.5 Section 152.5...INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY...SALE OF CERTAIN INDIAN LANDS Issuing Patents in Fee, Certificates of Competency...

2013-04-01

84

25 CFR 152.4 - Application for patent in fee.  

...2014-04-01 false Application for patent in fee. 152.4 Section 152.4...INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY...SALE OF CERTAIN INDIAN LANDS Issuing Patents in Fee, Certificates of Competency...

2014-04-01

85

25 CFR 152.5 - Issuance of patent in fee.  

... 2014-04-01 false Issuance of patent in fee. 152.5 Section 152.5...INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY...SALE OF CERTAIN INDIAN LANDS Issuing Patents in Fee, Certificates of Competency...

2014-04-01

86

25 CFR 152.5 - Issuance of patent in fee.  

Code of Federal Regulations, 2012 CFR

... 2011-04-01 true Issuance of patent in fee. 152.5 Section 152.5...INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY...SALE OF CERTAIN INDIAN LANDS Issuing Patents in Fee, Certificates of Competency...

2012-04-01

87

42 CFR 84.152 - Breathing tube test; minimum requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Breathing tube test; minimum requirements. 84.152...Supplied-Air Respirators § 84.152 Breathing tube test; minimum requirements. (a...shall employ one or two flexible breathing tubes of the nonkinking type which extend...

2013-10-01

88

Characterization of the surface changes during the activation process of erbium/erbium oxide for hydrogen storage.  

SciTech Connect

Erbium is known to effectively load with hydrogen when held at high temperature in a hydrogen atmosphere. To make the storage of hydrogen kinetically feasible, a thermal activation step is required. Activation is a routine practice, but very little is known about the physical, chemical, and/or electronic processes that occur during Activation. This work presents in situ characterization of erbium Activation using variable energy photoelectron spectroscopy at various stages of the Activation process. Modification of the passive surface oxide plays a significant role in Activation. The chemical and electronic changes observed from core-level and valence band spectra will be discussed along with corroborating ion scattering spectroscopy measurements.

Zavadil, Kevin Robert; Snow, Clark Sheldon; Ohlhausen, James Anthony; Brumbach, Michael Todd

2010-10-01

89

50 CFR 216.152 - Permissible methods of taking.  

Code of Federal Regulations, 2013 CFR

...TAKING AND IMPORTING OF MARINE MAMMALS Taking Of Marine Mammals Incidental To Missile Launch Activities from San Nicolas Island, CA § 216.152 Permissible methods of taking. (a) Under Letters of Authorization issued pursuant to §§...

2013-10-01

90

44 CFR 152.4 - Roles and responsibilities.  

Code of Federal Regulations, 2013 CFR

...Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY FIRE PREVENTION AND CONTROL ASSISTANCE TO FIREFIGHTERS GRANT PROGRAM § 152.4 Roles and responsibilities. (a) Applicants must: (1) Complete the application...

2013-10-01

91

44 CFR 152.3 - Availability of funds.  

Code of Federal Regulations, 2013 CFR

...HOMELAND SECURITY FIRE PREVENTION AND CONTROL ASSISTANCE TO FIREFIGHTERS GRANT PROGRAM § 152.3 Availability of funds. ...departments that have received funding under the Assistance to Firefighter Grant Program in previous years are eligible to...

2013-10-01

92

44 CFR 152.5 - Review process and evaluation criteria.  

Code of Federal Regulations, 2013 CFR

...HOMELAND SECURITY FIRE PREVENTION AND CONTROL ASSISTANCE TO FIREFIGHTERS GRANT PROGRAM § 152.5 Review process and evaluation...applications that are determined to best address the Assistance to Firefighters Grant Program's established priorities during...

2013-10-01

93

44 CFR 152.8 - Application submission and deadline.  

Code of Federal Regulations, 2013 CFR

...Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY FIRE PREVENTION AND CONTROL ASSISTANCE TO FIREFIGHTERS GRANT PROGRAM § 152.8 Application submission and deadline. In each year that this program is authorized and...

2013-10-01

94

7 CFR 4280.152 - Servicing guaranteed loans.  

...SERVICE AND RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOANS AND GRANTS Rural Energy for America Program General Renewable Energy System and Energy Efficiency Improvement Guaranteed Loans § 4280.152 Servicing guaranteed...

2014-01-01

95

32 CFR 1906.152-1906.159 - [Reserved  

Code of Federal Regulations, 2013 CFR

...Regulations Relating to National Defense CENTRAL INTELLIGENCE AGENCY ENFORCEMENT OF NONDISCRIMINATION ON THE...IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE CENTRAL INTELLIGENCE AGENCY §§ 1906.152-1906.159...

2013-07-01

96

40 CFR 152.403 - Definitions of fee categories.  

Code of Federal Regulations, 2013 CFR

...PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES Registration Fees § 152.403...in a tank mix, already registered for the crops involved) and no more than three crops. This fee does not apply to...

2013-07-01

97

18 CFR 152.2 - Form of application; service.  

Code of Federal Regulations, 2013 CFR

...RESALE § 152.2 Form of application; service. The application must be filed with the Secretary...posted on the Commission's Web site at http://www.ferc.gov. A copy of the application shall be served on the...

2013-04-01

98

50 CFR 15.2 - Scope of regulations.  

Code of Federal Regulations, 2013 CFR

...INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS WILD BIRD CONSERVATION ACT Introduction and General Provisions § 15.2 Scope of regulations. (a) The...

2013-10-01

99

40 CFR 205.152 - Noise emission standards.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 2013-07-01 false Noise emission standards. 205.152 Section...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles §...

2013-07-01

100

27 CFR 479.152 - Penalties (records and returns).  

Code of Federal Regulations, 2011 CFR

...Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND CERTAIN OTHER FIREARMS Examination of Books and Records § 479.152 Penalties (records...

2011-04-01

101

PDT for malignant tumors: a clinical analysis of 152 cases  

NASA Astrophysics Data System (ADS)

Hematoporphyrin derivative (HPD) laser photodynamic therapy (PDT) was applied for the patients of 152 cases of malignant tumors, including tumors of the lip, tongue, esophagus, urinary bladder, skin, larynx, vagina, etc. Since early 1981 good results have been obtained.

Zhuang, Shi-Zhang; Wang, Yun-Zhen; Li, Xin; Zhang, Changjun; Wang, Jian-Zhao; Zhang, Da-Ren

1993-03-01

102

49 CFR 572.152 - Head assembly and test procedure.  

Code of Federal Regulations, 2013 CFR

...SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES CRABI 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to §...

2013-10-01

103

45 CFR 1153.152-1153.159 - [Reserved  

Code of Federal Regulations, 2013 CFR

...Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE ARTS ENFORCEMENT OF NONDISCRIMINATION ON THE...CONDUCTED BY THE NATIONAL ENDOWMENT FOR THE ARTS §§ 1153.152-1153.159...

2013-10-01

104

Erbium Laser Model for Two-Wavelength Operation  

Microsoft Academic Search

A theoretical modeling of dual wavelength operation of erbium-doped fibre lasers is presented. The model is a generalization of the one used in the single mode theory, based on the existence of isolated ions and ion pairs coupled via the laser field. Analytical results are obtained in the steady state. The linear stability analysis of the coupled equations shows the

François Sanchez; Marc Le Flohic; Pascal Besnard; Pierre-Luc François; Guy Michel Stephan

1995-01-01

105

Gain analysis of Erbium and Ytterbium Doped Optical Fiber Amplifiers  

Microsoft Academic Search

In this study, importance of optical amplifiers which are used in optical communication systems is explained and gains of EDFA, Erbium Doped Fiber Amplifier, and YDFA, Ytterbium Doped Fiber Amplifier, which are among the most commonly used optical amplifiers today, are analysed based on their performance parameters. The effects of the power of input signal, the power of pump laser,

Tolga Kucukarslan; N. Ozlem Unverdi

2012-01-01

106

Multiple wavelength operation of an erbium-doped fiber laser  

Microsoft Academic Search

Wavelength-locked, six-channel, colasing operation using a single gain medium is reported for the first time. The system is an all-fiber, erbium-amplifier-based design that uses a grating wavelength division multiplexer with a fixed channel spacing of 4.8 nm for frequency selection. The authors investigate two possible configurations for the laser cavity

J. W. Dawson; K. J. Vahala

1992-01-01

107

Modeling of gain in erbium-doped fiber amplifiers  

Microsoft Academic Search

An analytic method is described for fully characterizing the gain of an erbium-doped fiber amplifier (EDFA) that is based on easily measured monochromatic absorption data. The analytic expressions presented, which involve the solution of one transcendental equation, can predict signal gains and pump absorptions in an amplifier containing an arbitrary number of pumps and signals from arbitrary directions. The gain

A. A. M. Saleh; R. M. Jopson; J. D. Evankow; J. Aspell

1990-01-01

108

The design of erbium-doped fiber amplifiers  

Microsoft Academic Search

An accurate model for the erbium-doped fiber amplifier is presented. The model is used to design the index profile of the doped fiber, optimizing with regard to efficiency for inline- and preamplifiers as well as for power booster amplifiers. The predicted pump efficiencies (maximum gain to pump power ratios) are in agreement with experimental results presented in the literature. The

Bo Pedersen; Anders Bjarklev; J. H. Povlsen; Kristen Dybdal; Carl Christian Larsen

1991-01-01

109

The gettering action of evaporated films of titanium and erbium  

Microsoft Academic Search

The maximum sorption capacities of titanium and erbium films for oxygen and hydrogen at 295 K were measured in a UHV adsorption vessel. The amount of gas taken up by each film was related to the number of metal atoms comprising it, and to its real surface area. Another apparatus, with a mass spectrometer, was used to study the gettering

J. Müller; B. Singh; N. A. Surplice

1972-01-01

110

Efficiency of a passively Q-switched erbium glass laser  

NASA Astrophysics Data System (ADS)

The methods for optimising the efficiency of low-threshold flashlamp-pumped passively Q-switched erbium glass lasers are studied. The optimisation is performed by varying the degree of filling an active element by the field of a lowest transverse mode.

Bykov, V. N.; Sadovoi, A. G.

2002-03-01

111

Erbium:YAG Laser Resurfacing for Refractory Melasma  

Microsoft Academic Search

background. Melasma is a facial dyspigmentation which is a common complaint in patients with darker skin tones. Many current therapies used for this condition are ineffective and can cause significant adverse effects. objective. The purpose of this study was to evaluate the role of erbium:YAG laser resurfacing in the management of refrac- tory melasma. methods. Ten female patients with melasma

Rhesa May P. Manaloto; Tina Alster

1999-01-01

112

25 CFR 152.15 - Judicial review of removal of restrictions, Five Civilized Tribes, without application.  

Code of Federal Regulations, 2011 CFR

...Five Civilized Tribes, without application. 152.15 Section 152.15 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF...of Competency Or Orders Removing Restrictions § 152.15 Judicial review of removal of restrictions,...

2011-04-01

113

19 CFR 152.104 - Transaction value of identical merchandise and similar merchandise.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Transaction value of identical merchandise and similar merchandise. 152.104 Section 152.104 Customs...CONTINUED) CLASSIFICATION AND APPRAISEMENT OF MERCHANDISE Valuation of Merchandise § 152.104...

2010-04-01

114

N=90 region: The decays of {sup 152}Eu{sup m,g} to {sup 152}Sm  

SciTech Connect

The decays of {sup 152}Eu{sup m,g}{yields}{sup 152}Sm have been studied by {gamma}-ray spectroscopy using the 8{pi} spectrometer, an array of 20 Compton-suppressed Ge detectors. Very weak {gamma}-decay branches in {sup 152}Sm were investigated through {gamma}-{gamma} coincidence spectroscopy. All possible E2 transitions between states below 1550 keV with transition energies >130 keV are observed, including the previously unobserved 2{sub 3}{sup +}{yields}0{sub 2}{sup +} 401 keV transition. The results, combined with existing lifetime data, provide a number of new or revised E2 transition strengths which are critical for clarifying the collective structure of {sup 152}Sm and the N=90 isotones.

Kulp, W. D.; Wood, J. L.; Allmond, J. M.; Eimer, J.; Furse, D.; Krane, K. S.; Loats, J.; Schmelzenbach, P.; Stapels, C. J.; Larimer, R.-M.; Norman, E. B.; Piechaczek, A. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States) and Department of Physics, Oregon State University, Corvallis, Oregon 97331-6507 (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

2007-09-15

115

Erbium--169 versus triamcinolone hexacetonide in the treatment of rheumatoid finger joints.  

PubMed Central

Erbium--169 was compared with triamcinolone hexacetonide in the topical treatment of 32 patients suffering from rheumatoid arthritis. Erbium--169 was injected into 83 and triamcinolone hexacetonide into 54 proximal interphalangeal or metacarpophalangeal joints. Both treatments produced alleviation of joint pain and swelling and improvement of grip strength. At every check-up (1--18 months) the percentage of remissions was higher after triamcinolone hexacetonide injection than after erbium--169. The difference was significant at 1, 3, and 6 months.

Ruotsi, A; Hypen, M; Rekonen, A; Oka, M

1979-01-01

116

Erbium--169 versus triamcinolone hexacetonide in the treatment of rheumatoid finger joints.  

PubMed

Erbium--169 was compared with triamcinolone hexacetonide in the topical treatment of 32 patients suffering from rheumatoid arthritis. Erbium--169 was injected into 83 and triamcinolone hexacetonide into 54 proximal interphalangeal or metacarpophalangeal joints. Both treatments produced alleviation of joint pain and swelling and improvement of grip strength. At every check-up (1--18 months) the percentage of remissions was higher after triamcinolone hexacetonide injection than after erbium--169. The difference was significant at 1, 3, and 6 months. PMID:434946

Ruotsi, A; Hypén, M; Rekonen, A; Oka, M

1979-02-01

117

Broadband 1.5- ?m emission of high erbium-doped Bi 2O 3-B 2O 3-Ga 2O 3 glasses  

NASA Astrophysics Data System (ADS)

High Erbium-doped glass showing the wider 1.5-?m emission band is reported in the Bi 2O 3-B 2O 3-Ga 2O 3 system and its thermal stability and optical properties such as absorption, emission spectra, absorption and stimulated emission cross-sections and fluorescence lifetime are investigated. Compared with other glass hosts, the gain bandwidth properties of high Er 3+ content in BBG glass are better than those of tellurite, germanate, silicate and phosphate glasses. The broad and flat 4I 13/2? 4I 15/2 emission and the larger stimulated emission cross-section of Er 3+ ions around 1.5 ?m enable it to be used as a host material for potential broadband optical amplifiers at C and L bands in the microchip configuration.

Fan, Huiyan; Wang, Guonian; Li, Kefeng; Hu, Lili

2010-07-01

118

Erbium Implantation in Silica Studied by Molecular Dynamics Simulations  

SciTech Connect

Defect formation induced by erbium implantation in silica glass and cristobalite was studied using molecular dynamics simulations employing a partial charge model in combination with the ZBL potential. The results show that the number of displaced atoms generated at the same PKA energy is similar in silica and cristobalite but the number of coordination defects created is much lower in the cristobalite than in silica glass. In both cases, the erbium ion is able to create an optimal coordination environment at the end of the collision cascade. Subsequent thermal annealing causes the relaxation of the silicon oxygen network structure along with a reduction of silicon and oxygen defects. This research is supported by the Divisions of Materials Sciences and Engineering and Chemical Science, Office of Basic Energy Sciences, U.S. Department of Energy. The Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Du, Jincheng; Corrales, Louis R.

2007-02-01

119

Synthesis of erbium hydroxide microflowers and nanostructures in subcritical water.  

PubMed

The effects of temperature, pressure, pH, residence time and reactant concentrations, as well as the presence or absence of CO(2), on the size and morphology of erbium hydroxide particles synthesized in a hydrothermal batch reactor and a diamond-anvil cell (DAC) reactor have been investigated. Several new erbium-based microstructures and nanostructures were obtained that encompass different phases and shapes, including crystalline microflowers, hexagonal microlayers, microsticks and microspheres made from nanoparticles, as well as nanofibers, nanorods and nanolayers. The Er(2)OCO(3)(OH)(2) microflowers are pure, structurally uniform, and mostly free from dislocations. Their crystallinity, morphology, optical properties and structural features have been examined and compared with those of the other phases by field-emission scanning electron microscopy (SEM), x-ray diffraction (XRD), and energy-dispersive x-ray (EDX) analysis, and by Raman, infrared, UV-visible and fluorescence spectroscopy. PMID:21825694

Assaaoudi, H; Fang, Z; Butler, I S; Kozinski, J A

2008-05-01

120

Spectral changes in the thermoluminescence of erbium in strontium fluoride  

NASA Astrophysics Data System (ADS)

Thermoluminescence from alkaline-earth halides with rare-earth ions shows emission signals from both the host and the dopants. In many cases each glow peak contains a complete set of emission lines from the rare-earth dopant, but in the case of Er in SrF2 the spectra change significantly with temperature. In part this is interpreted as evidence for a range of erbium sites, and in part as evidence for energy transfer between erbium states. Near 200 °C the conversion between the 545 and 525 nm emission lines follows a thermally activated pattern consistent with the differences in their initial energy states. This pair of transitions define more glow peaks than signals from the other Er lines. Spectrally analysed recording of the thermoluminescence is thus essential to separate the closely spaced glow peaks.

Maghrabi, M.; Townsend, P. D.

2000-11-01

121

Synthesis of erbium hydroxide microflowers and nanostructures in subcritical water  

NASA Astrophysics Data System (ADS)

The effects of temperature, pressure, pH, residence time and reactant concentrations, as well as the presence or absence of CO2, on the size and morphology of erbium hydroxide particles synthesized in a hydrothermal batch reactor and a diamond-anvil cell (DAC) reactor have been investigated. Several new erbium-based microstructures and nanostructures were obtained that encompass different phases and shapes, including crystalline microflowers, hexagonal microlayers, microsticks and microspheres made from nanoparticles, as well as nanofibers, nanorods and nanolayers. The Er2OCO3(OH)2 microflowers are pure, structurally uniform, and mostly free from dislocations. Their crystallinity, morphology, optical properties and structural features have been examined and compared with those of the other phases by field-emission scanning electron microscopy (SEM), x-ray diffraction (XRD), and energy-dispersive x-ray (EDX) analysis, and by Raman, infrared, UV-visible and fluorescence spectroscopy.

Assaaoudi, H.; Fang, Z.; Butler, I. S.; Kozinski, J. A.

2008-05-01

122

Undersea lightwave communications systems using erbium-doped fiber amplifiers  

Microsoft Academic Search

The new lightwave technology based on the erbium-doped fiber-amplifier (EDFA) will allow the next generation of undersea cable systems to have eight times the capacity of existing cables. In this paper error-free transmission over 9000 km has been demonstrated using EDFAs both at 5 Gb\\/s and 10 Gb\\/s. The characteristic of optical amplifier systems - more noise on the marks

N. S. Bergano

1993-01-01

123

Dynamics of high-power erbium-ytterbium fiber amplifiers  

Microsoft Academic Search

Dynamic regimes of high-peak-power erbium-ytterbium (Er3+-Yb3+) codoped fiber amplifiers are analyzed for nanosecond-to-microsecond pulses. High-energy pulse generation requires a large-core fiber amplifier to increase energy storage and the threshold of nonlinear effects. A numerical model of large-core Er3+-Yb3+ fiber amplifiers is described. Dynamics of peak powers, amplified spontaneous emission, and population inversion are presented. Influence of radial dependence and reflections

Guillaume Canat; Jean-Claude Mollier; Jean-Pierre Bouzinac; Glenn M. Williams; Brian Cole; Lew Goldberg; Yves Jaouën; Gabor Kulcsar

2005-01-01

124

Laser isotope separation of erbium and other isotopes  

DOEpatents

Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of {sup 167}Er. The hyperfine structure of {sup 167}Er was used to find two three-step photoionization pathways having a common upper energy level. 3 figs.

Haynam, C.A.; Worden, E.F.

1995-08-22

125

Laser isotope separation of erbium and other isotopes  

SciTech Connect

Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of .sup.167 Er. The hyperfine structure of .sup.167 Er was used to find two three-step photoionization pathways having a common upper energy level.

Haynam, Christopher A. (3035 Ferdale Ct., Pleasanton, CA 94566); Worden, Earl F. (117 Vereda del Ciervo, Diablo, CA 94528)

1995-01-01

126

Efficient multiwavelength dynamic model for erbium-doped fiber amplifier  

Microsoft Academic Search

An efficient full spectrum (1480-1600 nm) large-signal transient dynamic model of an erbium-doped fiber amplifier (EDFA) is developed. A technique to speed up the simulation by a factor of 1000 using artificial delay lines based on the transmission-line model (TLM) is presented. Simulations and experimental results show the delay line method is not detrimental to the accuracy of the model.

Alfred W. T. Wu; Arthur J. Lowery

1998-01-01

127

Gain modulation response of erbium-doped fiber amplifiers  

Microsoft Academic Search

The small-signal low frequency response characteristics of erbium-doped fiber amplifiers (EDFAs) are examined theoretically and experimentally. Modulating the pump laser results in a low-pass transfer of modulation from the pump to signals amplified in the EDFA. A signal modulated at low frequencies and amplified by an EDFA experiences a transfer function that is similar to that of a lead compensator,

J. Freeman; J. Conradi

1993-01-01

128

Vibrations produced during erbium:yttrium–aluminum–garnet laser irradiation  

Microsoft Academic Search

The purpose of this study was to evaluate vibrations induced by an erbium:yttrium–aluminum–garnet (Er:YAG) laser in the non-contact\\u000a mode and compare the vibrations with different pulse durations and energy parameters. The experiment was conducted on an extracted\\u000a tooth built up in silicone impression material. The vibrations were measured by piezoelectric accelerometer for a super-short\\u000a pulse (SSP), a very short pulse

Ivica Anic; Ivana Miletic; Silvana Jukic Krmek; Josipa Borcic; Sonja Pezelj-Ribaric

2009-01-01

129

Erbium-doped waveguides fabricated with atomic layer deposition method  

Microsoft Academic Search

Atomic layer deposition was used in preparing erbium (Er)-doped waveguides. Ridge-type Er-doped Al2O3 waveguides were patterned on silica-coated silicon wafers using photolithography and wet etching. Optical absorption, emission, fluorescence lifetime, and signal enhancement measurements were performed. Polarization dependence of the absorption spectrum and birefringence of the waveguide were measured. The material showed strong absorption and wide emission spectrum around 1530

Kimmo Solehmainen; Markku Kapulainen; Päivi Heimala; Kirsi Polamo

2004-01-01

130

Optical emission from erbium-doped silica nanowires  

NASA Astrophysics Data System (ADS)

Infrared optical emission from erbium-doped silica nanowires is shown to have property characteristic of the material nanostructure and to provide the basis for the fabrication of integrated photonic devices and biosensors. Silica nanowires of approximately 150 nm diameter were grown on a silicon wafer by metal-induced growth using a thin (20 nm) sputter-deposited palladium layer as a catalyst. The resulting wires were then ion implanted with 110 keV ErO- ions and annealed at 900 °C to optically activate the erbium. These wires exhibited photoluminescence emission at 1.54 ?m, characteristic of the 4I15/2-4I13/2 transition in erbium; however, comparison to similarly implanted fused silica layers revealed stronger thermal quenching and longer luminescence lifetimes in the nanowire samples. The former is attributed to an increase in defect-induced quenching partly due to the large surface-volume ratio of the nanowires, while the latter is attributed to a reduction in the optical density of states associated with the nanostructure morphology. Details of this behavior are discussed together with the implications for potential device applications.

Elliman, R. G.; Wilkinson, A. R.; Kim, T.-H.; Sekhar, P. K.; Bhansali, S.

2008-05-01

131

Silicon nanocrystal density effects in sensitizing erbium atoms  

NASA Astrophysics Data System (ADS)

Sensitization of erbium through silicon nanocrystals in silicon rich oxide (SRO) host, and the resulting luminescence at 1.54 ?m were studied in detail. Silicon nanocrystals (Si-nc) were shown to work as the gateway for energy transfer to erbium atoms. Excitation of silicon nanocrystals by the incident photon flux, and the subsequent transfer of energy to erbium atoms were modeled. Effects of energy back transfer processes through co-operative up conversion and Auger related processes were incorporated. Simulation results show that increase in Si-nc incorporation would correspond to enhanced Er luminescence and a lower threshold level of excitation for population inversion. Effective capture crosssection values for the overall sensitization process were estimated to be in the range of 10-17/cm2 for moderate Si-nc incorporation densities of 1018/cm3. Strong reductions of capture cross-section values were estimated for higher excitation fluxes. Increase of Er incorporation density in SRO host with constant level of Si-nc density resulted in increases in luminescence estimations, but with reductions in effective capture cross-section values. Results reveal that, Si-nc and Er densities in a SRO system need to be optimized for efficient Er sensitization, and the feasibility of achieving stimulated emission.

Huda, M. Q.

2013-02-01

132

152. View of lightning arrester houses on the hillside above ...  

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

152. View of lightning arrester houses on the hillside above powerhouse. To the right is surge tank for penstock no. 1. Looking southeast. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

133

Precision intensities and angular correlation measurements in ^152Sm  

NASA Astrophysics Data System (ADS)

The samarium isotopic chain shows great structural change dripline-to-dripline; evolving from deformed at the proton dripline, through spherical near stability before undergoing another transformation near N=90 when large prolate deformation re-emerges. Lying at the midpoint of this latter transition is ^152Sm. Numerous models have been developed to explain ^152Sm in terms of either being at the critical point of a phase transition, or in terms of coexisting shapes. To test the validity of these different models, a beta-decay experiment was performed at the ATLAS facility at Argonne. The decay of ^152Eu to ^152Sm was studied through gamma-ray spectroscopy using Gammasphere. An extremely large data set was collected, consisting of > 7x10^9 gamma-gamma or higher fold events. This made possible a high precision measurement of energies and intensities and very definite angular correlation determinations. The new results resolve some previous experimental ambiguities and help to differentiate between theoretical models. Work supported by the DOE Office of Nuclear Physics under contract DE-AC02-06CH11357.

McCutchan, E. A.; Lister, C. J.; Zhu, S.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Seweryniak, D.

2010-11-01

134

152. Photocopy of drawing (taken from Twin Falls Canal Company ...  

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

152. Photocopy of drawing (taken from Twin Falls Canal Company Surveyor's Transit Book #363, Page 1). 1912 CONDITION REPORT OF MILNER DAM AREA, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

135

45 CFR 152.45 - Transition to the exchanges.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Transition to the exchanges...REQUIREMENTS RELATING TO HEALTH CARE ACCESS PRE-EXISTING...INSURANCE PLAN PROGRAM Transition to Exchanges § 152...develop procedures to transition PCIP enrollees to...1321 of the Affordable Care Act, to ensure...

2010-10-01

136

45 CFR 1181.152-1181.159 - [Reserved  

Code of Federal Regulations, 2013 CFR

...NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES INSTITUTE OF MUSEUM AND LIBRARY SERVICES ENFORCEMENT OF NONDISCRIMINATION ON...HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE INSTITUTE OF MUSEUM AND LIBRARY SERVICES §§ 1181.152-1181.159...

2013-10-01

137

"Trinitite": Cobalt-60, Cesium-137, and Europium-152.  

PubMed

Cobalt-60, cesium-137, and europium-152 have been identified in "trinitite," an artifical mineral produced in the first nuclear explosion at Alamagordo, New Mexico, in 1945. Cesium-137 is an expected fission product, but the origin of the other two radionuclides is not certain. PMID:17751047

Salter, L P; Harley, J H

1965-05-14

138

Double-blind study of erbium 169 injection (synoviorthesis) in rheumatoid digital joints  

Microsoft Academic Search

A double-blind study of erbium 169 injection into rheumatoid digital joints was carried out with saline as control. 201 joints in 36 patients were studied (137 metacarpophalalangeal, 64 proximal interphalangeal). Erbium 169 was injected into 121 joints and saline water into 80 joints. Local injection of corticosteroids was given to both groups. A definite improvement was observed in 55% to

C J Menkes; A L Gô; P Verrier; M Aignan; F Delbarre

1977-01-01

139

Observation of superluminal and slow light propagation in erbium-doped optical fiber  

Microsoft Academic Search

We observe both extremely slow and superluminal pulse propagation speeds at room temperature in an erbium-doped fiber (EDF). A signal at 1550 nm is sent through an erbium-doped fiber with varying powers of a 980 nm pump. The degree of signal delay or advancement is found to depend significantly on the pump intensity. We observe a maximum fractional advancement of

A. Schweinsberg; N. N. Lepeshkin; M. S. Bigelow; R. W. Boyd; S. Jarabo

2006-01-01

140

Erbium doped ceramic nanofiber synthesis for thermophotovoltaic selective emitter applications  

NASA Astrophysics Data System (ADS)

This thesis explored the development of isothermal selective emitters for harvesting thermal energy to be used in conjunction with photovoltaic cells. The selective emitters were Erbium doped Titania nanofibers and Erbium and Yttrium doped Titania nanofibers that may be used with a Gallium Antimonide photovoltaic cell. The ultimate aim of this research was to develop Erbium doped Yttrium Titanate nanofibers. This research is of importance in recovering heat from a number of resources including power plant boilers. The thermal energy lost in the boilers can be as high as 20% of the input fuel energy and a recovery of this energy would boost the thermal performance of the power plants. It has been observed that the temperatures of the flue gas reaching the heat recovery region may be higher than 1600K and the radiation and convective losses in the burner occurs at even higher temperatures. Thermophotovoltaics (TPV) offer a solution in terms of converting the thermal energy to electricity without any moving parts. The efficiencies of conventional TPVs are very small (10-20%) and thus not a solution as the primary electric generator. However, in the field of the harvesting of waste energy, TPVs have tremendous potential. In order to improve efficiencies, Erbia (which can absorb thermal energy and convert it to electromagnetic radiation with a narrow wavelength spectrum with mean wavelength of 1500nm) can be used as a selective emitter with GaSb PV cells (which have its maximum efficiency in the same wavelength range) as the collector. In order to further improve its performance, the Erbia was proposed to be supported by Titania, which is transparent to IR in this range. However, past research has shown that the Erbia doped Titania nanofibers essentially have Erbium in the form of pyrochlore Erbium Titanate. Thus the research focused on a way to synthesize ErxY2-xTi 2O7 pyrochlore structure to act as the selective emitter. The self-supporting composite was designed to be nanostructured to ensure isothermal operation and a high surface to volume ratio to minimize re-adsorption and to have a compact design. The nanofiber emitters were prepared by electrospinning. This thesis demonstrated a synthesis procedure of optically selective nano-composites using electrospinning.

Trifon, George Sebastian

141

Search for intrinsic collective excitations in {sup 152}Sm  

SciTech Connect

The 685 keV excitation energy of the first excited 0{sup +} state in {sup 152}Sm makes it an attractive candidate to explore expected two-phonon excitations at low energy. Multiple-step Coulomb excitation and inelastic neutron scattering studies of {sup 152}Sm are used to probe the E2 collectivity of excited 0{sup +} states in this 'soft' nucleus and the results are compared with model predictions. No candidates for two-phonon K{sup {pi}}=0{sup +}quadrupole vibrational states are found. A 2{sup +},K=2 state with strong E2 decay to the first excited K{sup {pi}}=0{sup +} band and a probable 3{sup +} band member are established.

Kulp, W. D.; Wood, J. L.; Allmond, J. M. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States); Garrett, P. E. [Department of Physics, University of Guelph, Guelph, Ontario N0B 1S0 (Canada); TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Wu, C. Y.; Cline, D.; Hayes, A. B.; Hua, H.; Teng, R. [Nuclear Structure Research Laboratory, Department of Physics, University of Rochester, Rochester, New York 14627 (United States); Bandyopadhyay, D.; Choudry, S. N.; McEllistrem, M. T.; McKay, C. J.; Orce, J. N. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Dashdorj, D. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202 (United States); Mynk, M. G. [Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Yates, S. W. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055 (United States)

2008-06-15

142

Cep63 and Cep152 Cooperate to Ensure Centriole Duplication  

PubMed Central

Centrosomes consist of two centrioles embedded in pericentriolar material and function as the main microtubule organising centres in dividing animal cells. They ensure proper formation and orientation of the mitotic spindle and are therefore essential for the maintenance of genome stability. Centrosome function is crucial during embryonic development, highlighted by the discovery of mutations in genes encoding centrosome or spindle pole proteins that cause autosomal recessive primary microcephaly, including Cep63 and Cep152. In this study we show that Cep63 functions to ensure that centriole duplication occurs reliably in dividing mammalian cells. We show that the interaction between Cep63 and Cep152 can occur independently of centrosome localisation and that the two proteins are dependent on one another for centrosomal localisation. Further, both mouse and human Cep63 and Cep152 cooperate to ensure efficient centriole duplication by promoting the accumulation of essential centriole duplication factors upstream of SAS-6 recruitment and procentriole formation. These observations describe the requirement for Cep63 in maintaining centriole number in dividing mammalian cells and further establish the order of events in centriole formation.

Brown, Nicola J.; Marjanovic, Marko; Luders, Jens; Stracker, Travis H.; Costanzo, Vincenzo

2013-01-01

143

Erbium-doped fiber amplifier elements for structural analysis sensors  

NASA Technical Reports Server (NTRS)

The use of erbium-doped fiber amplifiers (EDFA's) in optical fiber sensor systems for structural analysis is described. EDFA's were developed for primary applications as periodic regenerator amplifiers in long-distance fiber-based communication systems. Their in-line amplification performance also makes them attractive for optical fiber sensor systems which require long effective lengths or the synthesis of special length-dependent signal processing functions. Sensor geometries incorporating EDFA's in recirculating and multiple loop sensors are discussed. Noise and polarization birefringence are also considered, and the experimental development of system components is discussed.

Hanna-Hawver, P.; Kamdar, K. D.; Mehta, S.; Nagarajan, S.; Nasta, M. H.; Claus, R. O.

1992-01-01

144

Atomic Mass and Nuclear Binding Energy for Er-169 (Erbium)  

NASA Astrophysics Data System (ADS)

This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Er-169 (Erbium, atomic number Z = 68, mass number A = 169).

Sukhoruchkin, S. I.; Soroko, Z. N.

145

Element-selective magnetometry in ferrimagnetic erbium iron garnet  

NASA Astrophysics Data System (ADS)

The emergence of a field induced canted phase below a critical temperature is one of the characteristic properties of ferrimagnets with two inequivalent antiferromagnetically coupled sublattices. Using x-ray magnetic circular dichroism at the Fe K edge, we have performed element selective magnetometry in ferrimagnetic erbium iron garnet in fields up to 30 T. The signal from the tetrahedral Fe sites at 70 K allows the detection of the two transitions at 10 and 23 T bounding the canted phase and the direct observation of the reversal of the Fe-sublattice magnetization within this phase.

Strohm, C.; Roth, T.; Detlefs, C.; van der Linden, P.; Mathon, O.

2012-12-01

146

Negative nonlinear absorption effect in glasses containing a large amount of erbium oxide  

NASA Astrophysics Data System (ADS)

Compositions which vitrify by means of a conventional glass melting method, containing a large amount of erbium ion were investigated in aluminosilicate, phosphate, borate, borosilicate, telluride and fluoride systems. As a result of melting test, we obtain some glasses which contain higher than 20 mol% erbium. In transparent materials containing erbium an anomalous optical absorption phenomena have been reported by Maeda et al. With increasing in an incident laser light intensity, the transmitted one through the transparency such as the glass decreases, that is called negative nonlinear absorption (NNA) effect. With a particular modulation degree of an incident laser light, the transmitted waveform were reversed in phase to an incident one. The NNA effect in these glasses was observed over a wide band of the wavelength, while in erbium doped yttrium aluminum garnet and erbium doped lutetium aluminum garnet crystals were observed at a narrow band. The discrepancy of the NNA effect between the glasses and the crystals might be explained in the term of absorption spectrum associated with erbium. Namely, the absorption spectra of erbium doped yttrium aluminum garnet crystal have a narrow absorption band of 788 nm, while that of the glasses have broad absorption band of about 800 nm.

Hashima, Hidekazu; Konishi, Akio; Wakabayashi, Hajimu; Yamada, Toshikazu; Maeda, Yoshinobu

1999-04-01

147

43 CFR 15.2 - Removal or destruction of natural features and marine life.  

Code of Federal Regulations, 2010 CFR

...destruction of natural features and marine life. 15.2 Section 15.2 Public...destruction of natural features and marine life. No person shall destroy...and shell fish starfishes or other marine invertebrates, seaweeds,...

2009-10-01

148

43 CFR 15.2 - Removal or destruction of natural features and marine life.  

Code of Federal Regulations, 2010 CFR

...destruction of natural features and marine life. 15.2 Section 15.2 Public...destruction of natural features and marine life. No person shall destroy...and shell fish starfishes or other marine invertebrates, seaweeds,...

2010-10-01

149

27 CFR 25.152 - Reduced rate of tax for certain brewers.  

Code of Federal Regulations, 2013 CFR

27 Alcohol, Tobacco Products and Firearms 1 2013-04-01...Section 25.152 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO...TREASURY ALCOHOL BEER Tax on Beer Liability for Tax § 25.152 Reduced...

2013-04-01

150

14 CFR 152.205 - United States share of project costs.  

...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...

2014-01-01

151

14 CFR 152.205 - United States share of project costs.  

Code of Federal Regulations, 2012 CFR

...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...

2012-01-01

152

14 CFR 152.205 - United States share of project costs.  

Code of Federal Regulations, 2010 CFR

...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...

2010-01-01

153

14 CFR 152.205 - United States share of project costs.  

Code of Federal Regulations, 2011 CFR

...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...

2011-01-01

154

14 CFR 152.205 - United States share of project costs.  

Code of Federal Regulations, 2013 CFR

...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...

2013-01-01

155

25 CFR 152.9 - Certificates of competency to certain Osage adults.  

Code of Federal Regulations, 2011 CFR

...certain Osage adults. 152.9 Section 152.9 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS...

2011-04-01

156

25 CFR 152.34 - Approval of mortgages and deeds of trust.  

Code of Federal Regulations, 2011 CFR

...152.34 Section 152.34 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Mortgages and Deeds...

2011-04-01

157

25 CFR 152.23 - Applications for sale, exchange or gift.  

Code of Federal Regulations, 2011 CFR

...152.23 Section 152.23 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

158

25 CFR 152.20 - Sale by Secretary of certain land in multiple ownership.  

Code of Federal Regulations, 2011 CFR

...152.20 Section 152.20 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

159

25 CFR 152.21 - Sale or exchange of tribal land.  

Code of Federal Regulations, 2011 CFR

...152.21 Section 152.21 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

160

30 CFR 1202.152 - Standards for reporting and paying royalties on gas.  

Code of Federal Regulations, 2013 CFR

...paying royalties on gas. 1202.152 ...Resources OFFICE OF NATURAL RESOURCES REVENUE...OF THE INTERIOR NATURAL RESOURCES REVENUE ROYALTIES Federal Gas § 1202.152 ...section. (3) Natural gas liquids (NGL)...

2013-07-01

161

40 CFR 68.152 - Substantiating claims of confidential business information.  

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 15 2010-07-01...152 Section 68.152 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...would, if disclosed, reveal trade secrets or other confidential...

2010-07-01

162

16 CFR 6.152 - Program accessibility: Electronic and information technology.  

...accessibility: Electronic and information technology. 6.152 Section 6.152 Commercial...accessibility: Electronic and information technology. (a) When developing, procuring...or using electronic and information technology, the Commission shall ensure,...

2014-01-01

163

16 CFR 6.152 - Program accessibility: Electronic and information technology.  

Code of Federal Regulations, 2011 CFR

...accessibility: Electronic and information technology. 6.152 Section 6.152 Commercial...accessibility: Electronic and information technology. (a) When developing, procuring...or using electronic and information technology, the Commission shall ensure,...

2011-01-01

164

16 CFR 6.152 - Program accessibility: Electronic and information technology.  

Code of Federal Regulations, 2010 CFR

...accessibility: Electronic and information technology. 6.152 Section 6.152 Commercial...accessibility: Electronic and information technology. (a) When developing, procuring...or using electronic and information technology, the Commission shall ensure,...

2010-01-01

165

34 CFR 668.152 - Administration of tests by assessment centers.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Administration of tests by assessment centers. 668.152 Section... Approval of Independently Administered Tests; Specification of Passing Score; Approval...Process § 668.152 Administration of tests by assessment centers. (a) If...

2013-07-01

166

24 CFR 1000.152 - How is the recipient to use criminal conviction information?  

Code of Federal Regulations, 2013 CFR

... false How is the recipient to use criminal conviction information? 1000.152...1000.152 How is the recipient to use criminal conviction information? (a) With...assistance, the recipient shall use the criminal conviction information described...

2013-04-01

167

Double-blind study of erbium 169 injection (synoviorthesis) in rheumatoid digital joints.  

PubMed

A double-blind study of erbium 169 injection into rheumatoid digital joints was carried out with saline as control. 201 joints in 36 patients were studied (137 metacarpophalalangeal, 64 proximal interphalangeal). Erbium 169 was injected into 121 joints and saline water into 80 joints. Local injection of corticosteroids was given to both groups. A definite improvement was observed in 55% to 58% of cases with erbium 169 (+prednisolone acetate) and in 26% to 28% of cases with saline (+prednisolone acetate). The difference was highly significant. PMID:327948

Menkes, C J; Gô, A L; Verrier, P; Aignan, M; Delbarre, F

1977-06-01

168

Double-blind study of erbium 169 injection (synoviorthesis) in rheumatoid digital joints.  

PubMed Central

A double-blind study of erbium 169 injection into rheumatoid digital joints was carried out with saline as control. 201 joints in 36 patients were studied (137 metacarpophalalangeal, 64 proximal interphalangeal). Erbium 169 was injected into 121 joints and saline water into 80 joints. Local injection of corticosteroids was given to both groups. A definite improvement was observed in 55% to 58% of cases with erbium 169 (+prednisolone acetate) and in 26% to 28% of cases with saline (+prednisolone acetate). The difference was highly significant.

Menkes, C J; Go, A L; Verrier, P; Aignan, M; Delbarre, F

1977-01-01

169

Evidence of two erbium sites in standard aluminosilicate glass for EDFA.  

PubMed

Site distributions of Er(3+)-doped aluminosilicate preforms of standard EDFA were studied by the low temperature Resonant Fluorescence Line Narrowing (RFLN) spectroscopy. Two erbium concentration samples with the same glass base were investigated. At very low erbium concentration, two classes of sites were identified, related to the number of AlO(6) octahedral linked by two oxygen edge-sharing to Er(3+) in the coordination sphere. As erbium concentration is increased, the high AlO(6) coordinated class of sites is smeared out by the optical response of the one AlO(6) coordinated class of sites. PMID:20940961

Peretti, R; Jurdyc, A M; Jacquier, B; Burov, E; Pastouret, A

2010-09-27

170

Fabrication and characterization of erbium-doped toroidal microcavity lasers  

NASA Astrophysics Data System (ADS)

Erbium-doped SiO2 toroidal microcavity lasers are fabricated on a Si substrate using a combination of optical lithography, etching, Er ion implantation, and CO2 laser reflow. Erbium is either preimplanted in the SiO2 base material or postimplanted into a fully fabricated microtoroid. Three-dimensional infrared confocal photoluminescence spectroscopy imaging is used to determine the spatial distribution of optically active Er ions in the two types of microtoroids, and distinct differences are found. Microprobe Rutherford backscattering spectrometry indicates that no macroscopic Er diffusion occurs during the laser reflow for preimplanted microtoroids. From the measured Er doping profiles and calculated optical mode distributions the overlap factor between the Er distribution and mode profile is calculated: ?=0.066 and ?=0.02 for postimplanted and preimplanted microtoroids, respectively. Single and multimode lasing around 1.5 ?m is observed for both types of microtoroids, with the lowest lasing threshold (4.5 ?W) observed for the preimplanted microtoroids, which possess the smallest mode volume. When excited in the proper geometry, a clear mode spectrum is observed superimposed on the Er spontaneous emission spectrum. This result indicates the coupling of Er ions to cavity modes.

Kalkman, J.; Tchebotareva, A.; Polman, A.; Kippenberg, T. J.; Min, B.; Vahala, K. J.

2006-04-01

171

25 CFR 15.2 - What definitions do I need to know?  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false What definitions do I need to know? 15.2 Section 15.2 Indians...Introduction § 15.2 What definitions do I need to know? Act means the Indian...intestate proceeding. Individual Indian Money (IIM) account means an...

2013-04-01

172

40 CFR 721.2580 - C.I. Disperse Red 152 (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false C.I. Disperse Red 152 (generic). 721.2580 Section...Substances § 721.2580 C.I. Disperse Red 152 (generic). (a) Chemical substance...identified generically as C.I. disperse red 152 (PMN P-97-820) is subject...

2013-07-01

173

University of Virginia Physics 152: Introductory Physics II  

NSDL National Science Digital Library

This is a set of resource materials for second-semester introductory physics, developed at the University of Virginia. The unifying theme of the course is applying Newtonâs Laws to a small segment of a large system to find laws governing the system as a whole. Resources include complete lecture notes, demonstrations, links to related interactive simulations, problem sets/study sheets for students, and downloadable animated spreadsheets. Physics 152 covers topics that include gravity, waves and oscillations, fluids, heat, and thermodynamics. It is intended for prospective physics majors or students who have some preparation in the fundamentals of calculus.

Fowler, Michael

2009-02-24

174

Generalized rate-equation analysis of excitation exchange between silicon nanoclusters and erbium ions  

SciTech Connect

We discuss the use of rate equations to analyze the sensitization of erbium luminescence by silicon nanoclusters. In applying the general form of second-order coupled rate-equations to the Si nanocluster-erbium system, we find that the photoluminescence dynamics cannot be described using a simple rate equation model. Both rise and fall times exhibit a stretched exponential behavior, which we propose arises from a combination of a strongly distance-dependent nanocluster-erbium interaction, along with the finite size distribution and indirect band gap of the silicon nanoclusters. Furthermore, the low fraction of erbium ions that can be excited nonresonantly is a result of the small number of ions coupled to nanoclusters.

Kenyon, A. J.; Wojdak, M.; Ahmad, I.; Loh, W. H.; Oton, C. J. [Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Optoelectronics Research Centre, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)

2008-01-15

175

Heat Capacity, Susceptibility, and Critical Temperature of Erbium Phosphate as Predicted by Dipole-Dipole Interactions.  

National Technical Information Service (NTIS)

In this paper the authors compute the heat capacity and susceptibility of erbium phosphate above the critical temperature, assuming that the interaction between the spins is purely dipolar. They also obtain, using the same assumption, the ground-state ene...

P. H. E. Meijer B. V. Kessler

1975-01-01

176

[Synoviorthesis of finger joints using erbium-169. Parameters influencing the clinical results at middle-term].  

PubMed

Synoviorthesis of the finger joint with erbium-169 is a beneficial therapeutic procedure which produces reduction of articular pain and swelling in 2/3 of cases. The effect is lasting and shows only slight regression during the first 24 months. However, if the rheumatoid disease is very active, or if the articular lesions are primarily erosive, the results are poorer. No correlation was found between therapeutic results and the radiological findings prior to 169E treatment. Erbium-169 reduces inflammation and leads to progressive articular fibrosis. Any chronic synovitis of interdigital joints resistant to appropriate conventional anti-inflammatory treatment may benefit from radio-synoviorthesis with erbium-169. Erbium-169 synoviorthesis is is technically easy to perform and free of side effects. It is a palliative measure which the authors consider a valuable complement to the classical treatment of rheumatoid arthritis. PMID:905816

Ott, H; Boussina, I; Fallet, G H

1977-10-01

177

Erbium-mediated photoconductivity of Ga Ge S Se : Er3+ chalcogenide glasses  

NASA Astrophysics Data System (ADS)

Photoconductivity mediated by erbium ions in chalcogenide glasses Ga-Ge-S has been found. The conductivity of glasses undoped and doped with erbium has been studied under irradiation by laser light at ? = 813 nm. In both cases the optical band-gap energy exceeds by several times the laser photon energy. It has been observed that the exposure to sub-band-gap light does not change the conductivity of the undoped glass, whereas it leads to a significant increase in the conductivity of the glass doped with erbium. We propose a two-photon mechanism of the photoconductivity in this glass, where erbium accumulates laser energy and then transfers it nonradiatively to the glass matrix (energy backtransfer).

Ivanova, T. Yu; Manshina, A. A.; Povolotskiy, A. V.; Tver'yanovich, Yu S.; Liaw, Shien-Kuei; Hsieh, Yao-Shung

2008-09-01

178

Laser trabecular ablation of human eyes with the erbium:YAG laser: a histopathologic study  

Microsoft Academic Search

We postulated that ablation of trabecular meshwork can be accomplished without damage to Schlemm's canal and adjacent tissue. We performed Erbium:YAG laser trabecular ablation on human autopsy eyes and confirmed the results by histopathologic examination. We used an Erbium:YAG laser (2.94 micrometers ) equipped with a sapphire probe and a quartz tip (350 micrometers diameter). Energy levels of 5, 10,

Theresa R. Kramer; Robert J. Noecker; Robert W. Snyder; Lansing G. Ellsworth; J. Michael Yarborough

1994-01-01

179

Multiwavelength operation of Brillouin\\/erbium fiber lasers with injection-locked seeding  

Microsoft Academic Search

Brillouin\\/erbium doped fiber lasers (BEFLs) have recently been demonstrated as a novel mode of operation of fiber lasers, using both the gain of an erbium-doped fiber (EDF) and Brillouin gain in single-mode optical fiber. BEFLs can be configured to produce laser combs, with potential applications in dense wavelength-division multiplexing. In this paper we present a different regime of operation of

G. J. Cowle; W. H. Loh; R. J. Laming; D. Y. Stepanov

1997-01-01

180

Resonantly photo-pumped nickel-like erbium X-ray laser  

DOEpatents

A resonantly photo-pumped X-ray laser (10) that enhances the gain of seve laser lines that also lase because of collisional excitations and recombination processes, is described. The laser comprises an aluminum (12) and erbium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like erbium ions (34) are resonantly photo-pumped by line emission from hydrogen-like aluminum ions (32).

Nilsen, Joseph (Livermore, CA)

1990-01-01

181

Optical gain at 1.54 mum in erbium-doped silicon nanocluster sensitized waveguide  

Microsoft Academic Search

Optical gain at 1.54 mum in erbium-doped silicon-rich silicon oxide (SRSO) is demonstrated. Er-doped SRSO thin film was fabricated by electron-cyclotron resonance enhanced chemical vapor deposition of silicon suboxide with concurrent sputtering of erbium followed by a 5 min anneal at 1000 °C. Ridge-type single mode waveguides were fabricated by wet chemical etching. Optical gain of 4 dB\\/cm of an

Hak-Seung Han; Se-Young Seo; Jung H. Shin

2001-01-01

182

Numerical Modeling and Optimization of Diode Pumped Heavily-Erbium-Doped Fluoride Fiber Lasers  

Microsoft Academic Search

Numerical modeling of heavily-erbium-doped fluoride fiber lasers is presented. Calculations from the model were compared with all previously reported experimental demonstrations of heavily-erbium-doped fluoride fiber lasers. Commensurate with recent modeling studies, good agreement with the measurements was achieved with the use of scaled-down rate parameters for energy transfer that corresponds to weaker interactions between ${\\\\rm Er}^{3+}$ ions. For wavelength-fixed (grating)

Jianfeng Li; Stuart D. Jackson

2012-01-01

183

Gain in erbium-doped fiber amplifiers: a simple analytical solution for the rate equations  

SciTech Connect

The solution of the rate equations that describe an erbium-doped fiber amplifier is investigated, and the possibility of obtaining an analytical solution for several field and erbium transverse distributions in the active fiber is determined. With the obtained equations it is possible to find directly the signal gain and the main parameters that influence it. The validity of this research is extended to the case of high signal power.

Peroni, M.; Tamburrini, M. (Fondazione Ugo Bordoni, Viale Europa 190, 00144 Rome (Italy))

1990-08-01

184

Lead test fuel assembly physics for erbium fuel at the San Onofre Nuclear Generating Station  

Microsoft Academic Search

ABB Combustion Engineering Nuclear Fuel (ABB C-E) has completed a qualification program for the use of Er[sub 2]O[sub 3] as a burnable absorber in pressurized water reactors. Neutronic properties and performance have been assessed in a development program that included the following: 1. evaluation and processing of basic cross-section data for naturally occurring erbium isotopes and capture\\/decay products of erbium

P. H. Gavin; A. Jonsson; S. Swoope; R. Y. Chang; O. J. Thomsen

1993-01-01

185

Mechanistic study on electrochemical codeposition of mixed zinc–erbium oxide films on the cathodic surface  

Microsoft Academic Search

Erbium doped zinc oxide thin films were prepared from aqueous solutions containing Zn(NO3)2 and Er(NO3)3 by the potentiostatic technique using a three-electrode system. The pH changes at the cathode\\/solution interface were in-situ measured during the electrodeposition process of mixed erbium–zinc hydroxide or oxide films. The solution- and solid-phase speciation distributions of the two metal ions and their hydroxides as a

Jian-Min Zhang; Xiang-Ming Feng

2008-01-01

186

Complete fusion in 7Li+144,152Sm reactions  

NASA Astrophysics Data System (ADS)

Complete fusion cross sections for 7Li+144,152Sm reactions have been measured at energies around the Coulomb barrier by offline ?-counting technique. Measured cross sections for the above two reactions are found to be similar at energies well above the Coulomb barrier, however, at sub-barrier energies the cross sections for the 7Li+152Sm system are much higher compared to the 7Li+144Sm system, manifesting the effect of target deformation. Cross sections for the present reactions at above-barrier energies are found to be larger than previously measured reactions involving 6Li projectile with the same targets, possibly due to smaller breakup probability of 7Li than 6Li. Coupled-channels calculations show that the experimental fusion cross sections for both the systems are enhanced at subbarrier energies and suppressed at above-barrier energies compared to the respective one-dimensional barrier penetration model predictions. The calculations by different models show that the measured complete fusion cross sections at above-barrier energies are suppressed up to ˜25% compared to the theoretical predictions. It also reveals that a large part of the suppression could be due to inelastic and transfer coupling.

Rath, P. K.; Santra, S.; Singh, N. L.; Nayak, B. K.; Mahata, K.; Palit, R.; Ramachandran, K.; Pandit, S. K.; Parihari, A.; Pal, A.; Appannababu, S.; Sharma, Sushil K.; Patel, D.; Kailas, S.

2013-10-01

187

Investigation of {sup 152}Sm by Complementary Reactions  

SciTech Connect

Understanding the nuclear structure of {sup 152}Sm, along with other N = 90 isotones, has long posed a challenge. A rapid transition in shape between the spherical N = 88 {sup 150}Sm and well-deformed N = 92 {sup 154}Sm is observed, along with strong evidence for shape coexistence. Competing ideas have been put forward over the decades, with the most recent being that N = 90 is at the critical point of a shape phase transition. Until recently, the lack of high-precision data has not allowed the competing models to be extensively tested. In a coordinated program of investigation, a series of complementary experiments, which include high-statistics {beta} decay, multi-step Coulomb excitation, the {sup 150}Nd({alpha},2n) reaction, and the (n,n'{gamma}) reaction, have been performed for {sup 152}Sm. These experiments have revealed the existence of a pairing-isomer band, a hexadecapole band, the lack of multi-phonon {beta} vibrational bands, and the repetition of structures built on the first excited K{sup {pi}} = 0{sup +} as built on the ground state. The status of these coordinated studies is examined.

Garrett, P. E. [Department of Physics, University of Guelph, Guelph, Ontario, N1G2W1 (Canada); Kulp, W. D.; Wood, J. L.; Allmond, J. M. [Department of Physics, Georgia Institute of Technology, Atlanta, Georgia, 30332 (United States); Bandyopadhyay, D.; Choudry, S. N.; Kumar, A.; Lesher, S. R.; McEllistrem, M. T.; Mynk, M. G.; McKay, C. J.; Orce, J. N. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky, 40506 (United States); Christen, S.; Dewald, A.; Fitzler, A.; Fransen, C.; Jessen, K.; Jolie, J.; Kloezer, A.; Kudejova, P. [Institut fuer Kernphysik, Universtaet zu Koeln, Zuelpicherstrasse 77, Koeln, D-50937 (Germany)] (and others)

2009-01-28

188

Six direct methods for standardisation of 152Eu  

NASA Astrophysics Data System (ADS)

In the course of the past 40 years, IRMM has developed a large number of direct methods for the accurate standardisation of radionuclide solutions, all providing traceability to the SI unit. Six different measurement methods were employed to standardise a 152Eu solution in the frame of a BIPM key comparison: 4??(PPC)-?-coincidence counting, using a modified version of the 'Funck' pressurised proportional counter (Ar-CH 4) for counting the electrons and low-energy photons, and a 15×15 cm NaI(Tl) well crystal for counting the ?-rays; 4??(PPC)-?-sum counting using the same equipment as above; 4??-?-coincidence counting, using a 2D shaped proportional counter (Kr-CH 4) sandwiched between two 7.5×7.5 cm 2 NaI(Tl) crystals; 4?? counting, using a 15×15 cm 2 NaI(Tl) well crystal; 4?CsI(Tl) counting; Liquid scintillation counting (LSC) using the CIEMAT/NIST method. The methods will be described and compared, with emphasis on their strengths and weaknesses. In the case of 152Eu, we were able to achieve a standard deviation of the weighted mean of 0.14% among all methods, or 0.11% when excluding the LSC result.

Johansson, L.; Altzitzoglou, T.; Sibbens, G.; Denecke, B.; Reher, D. F. G.

2003-08-01

189

Electroluminescence from zinc sulfide thin films doped with erbium trifluoride  

NASA Astrophysics Data System (ADS)

Near infrared emission at a wavelength of 1.55 mum from zinc sulfide (ZnS) doped with erbium trifluoride (ErF3) has been studied in alternating current thin film electroluminescent devices (ACTFELDs). The thin film phosphors were deposited by radio frequency (RF) planar magnetron sputtering of a 1.5 mol% ErF3-doped ZnS target and an undoped ZnS target. The intensity of near infrared emission is related to the processing parameters used in film deposition and post-deposition annealing. Thin films, approximately 650 nm thick, were deposited at 100 W from both targets. Deposition temperature, duty cycle, sputtering gas pressure and post-deposition annealing temperature were varied in a design-of-experiment. As deposition temperature was increased from 120°C to 150°C, the near infrared electroluminescence increased by ˜180% at an operating voltage 20 volts above the threshold voltage (B20). This is attributed to better activation of erbium luminescent centers on zinc lattice sites results in a greater number of radiative events, increasing luminescence. Increasing the duty cycle applied to the ZnS:ErF3 doped target from 25% to 75%, increased the electroluminescence at B20 by ˜650%. This likely results from a greater number of ErF3 dopants incorporated into the phosphor. As the sputtering gas pressure increases from 1 mTorr to 24 mTorr, the electroluminescence at B20 increases by ˜80%. At lower pressure, the phosphor undergoes negative ion resputtering removing zinc and sulfur from the film. This creates a film with a higher proportion of ErF3 dopant incorporated. After film deposition, a portion of the phosphor films underwent annealing for 1 hour in ultra high purity nitrogen at 425°C. Annealing films increased electroluminescence at B20 by ˜60%. The increase in brightness correlated with a reduction in fluorine incorporation in the film. Additionally the number of sulfur vacancies is likely reduced. This probably alters the local crystal field around the erbium dopant allowing for more adequate pathways for the near-infrared transitions, thus increasing the overall near infrared luminance. The highest brightness was observed for a deposition temperature of 150°C, a duty cycle of 75%, argon sputtering gas pressure of 24 mTorr and post-deposition annealing at 425°C. These conditions resulted in a brightness of the 1550 nm emission peak of 146.46 muW/cm2 at 20 V above threshold.

Devito, David Michael

190

Mechanical properties of melt-derived erbium oxide  

SciTech Connect

Erbium oxide (Er{sub 2}O{sub 3}) is a rare earth oxide that is chemically and thermally stable and has a melting point of 2,430 C. There is relatively little information available regarding single crystal growth of erbia or the properties of erbia. In this study, erbia single crystals have been grown in a Xenon Optical Floating Zone Unit (XeOFZ) capable of melting materials at temperatures up to 3,000 C. Erbia was melt synthesized in the XeOFZ unit in a container less fashion, proving for little chance of contamination. Crystals were grown in compressed air and in reducing atmospheres. A recurring problem with melt synthesis of erbia is the appearance of flakes at the edges of the melt zone during growth; these flakes disrupt the growth process. The processing details and an initial survey of the physical properties of erbia single crystals is discussed.

Neuman, A.D.; Blacic, M.J.; Platero, M.; Romero, R.S.; McClellan, K.J.; Petrovic, J.J.

1998-12-31

191

Enhanced near-infrared-luminescence in an erbium tetrafluoroterephthalate framework.  

PubMed

Two erbium-organic frameworks Er2(BDC)3(DMF)2(H2O)2.H2O (1) and Er2(BDC-F4)3(DMF)(H2O).DMF (2) (BDC = 1,4-benzenedicarboxylate; BDC-F(4) = 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylate or tetrafluoroterephthalate; DMF = dimethylformamide) have been synthesized and structurally characterized. Studies on thermal gravimetric analysis and the spectroscopic and luminescent properties of 1, 2, and their desolvated solid Er2(BDC)3 (1a) and partially desolvated solid Er2(BDC-F4)3(DMF).DMF (2a) indicate that fluorination can significantly improve the luminescence intensity of the Er ions by reducing the fluorescence quenching effect of the vibrational C-H bond; thus, the near-IR-luminescence intensity of 2a is 3 times higher than that of 1a. PMID:17054346

Chen, Banglin; Yang, Yu; Zapata, Fatima; Qian, Guodong; Luo, Yongshi; Zhang, Jiahua; Lobkovsky, Emil B

2006-10-30

192

Organo-erbium systems for optical amplification at telecommunications wavelengths.  

PubMed

Modern telecommunications rely on the transmission and manipulation of optical signals. Optical amplification plays a vital part in this technology, as all components in a real telecommunications system produce some loss. The two main issues with present amplifiers, which rely on erbium ions in a glass matrix, are the difficulty in integration onto a single substrate and the need of high pump power densities to produce gain. Here we show a potential organic optical amplifier material that demonstrates population inversion when pumped from above using low-power visible light. This system is integrated into an organic light-emitting diode demonstrating that electrical pumping can be achieved. This opens the possibility of direct electrically driven optical amplifiers and optical circuits. Our results provide an alternative approach to producing low-cost integrated optics that is compatible with existing silicon photonics and a different route to an effective integrated optics technology. PMID:24651429

Ye, H Q; Li, Z; Peng, Y; Wang, C C; Li, T Y; Zheng, Y X; Sapelkin, A; Adamopoulos, G; Hernández, I; Wyatt, P B; Gillin, W P

2014-04-01

193

Synthesis and properties of erbium oxide single crystals  

SciTech Connect

Erbium oxide (Er{sub 2}O{sub 3}, erbia) is a highly stable cubic rare earth oxide with a high melting point of 2,430 C. Because of this, it may have potential applications where high temperature stability and corrosion resistance are required. However, relatively little is known about the properties of this oxide ceramic. The authors have employed a xenon optical floating zone unit with a temperature capability of 3,000 C to grow high quality single crystals of erbia. The conditions for single crystal growth of erbia have been established. The mechanical properties of erbia single crystals have been initially examined using microhardness indentation as a function of temperature.

Petrovic, J.J.; Romero, R.S.; Mendoza, D.; Kukla, A.M.; Hoover, R.C.; McClellan, K.J.

1999-04-01

194

University of Virginia Physics 152: Oscillations and Waves  

NSDL National Science Digital Library

This is a set of instructional materials developed at the University of Virginia to support teaching a unit on waves and oscillation. It is intended for prospective physics majors or students who have some preparation in calculus fundamentals. Resources include lecture notes on waves in one, two, and three dimensions, sound waves, simple harmonic motion, boundary conditions, wave analysis, and wave properties. Look for links to related interactive simulations, problem sets, and study sheets for students. Of particular interest are the downloadable animated spreadsheets on addition of traveling waves. This resource is part of the full Physics 152 course, which covers topics typically included in a second-semester introductory physics class. SEE RELATED ITEMS ON THIS PAGE for a link to the full set of course materials.

Fowler, Michael

2009-02-24

195

MicroRNA-152 targets ADAM17 to suppress NSCLC progression.  

PubMed

MicroRNAs (miRNAs) are a class of small non-coding RNAs that have been suggested to play an essential role in tumorigenesis. In this study, we show that miR-152 is significantly downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines. Restoration of miR-152 significantly reduces proliferation, colony formation, migration and invasion of NSCLC cells. In addition, ADAM metallopeptidase domain 17 (ADAM17) is identified as a target of miR-152 in NSCLC cells, and miR-152-induced suppression of cell proliferation, colony formation, migration and invasion is partially mediated by silencing of ADAM17 expression. Furthermore, ADAM17 inversely correlates with miR-152 in NSCLC tissues. Collectively, our findings indicate that miR-152 acts as tumor suppressor in NSCLC partially via targeting ADAM17. PMID:24780186

Su, Yunshu; Wang, Yuchang; Zhou, Hongmin; Lei, Lei; Xu, Lijun

2014-05-21

196

Concentration quenching in erbium implanted alkali silicate glasses  

Microsoft Academic Search

A comparison is made of photoluminescence properties of six sodalime and alkali-borosilicate glasses implanted with Er to concentrations as high as 1.4 × 1021 at.\\/cm3. Clear photoluminescence (PL) spectra around 1.54 ?m, due to the 4I132?4I152 transition in Er3+ are observed, of which the shape depends on the host glass composition. PL lifetimes in the range of 0.9–12.6 ms are

E. Snoeks; P. G. Kik; A. Polman

1996-01-01

197

A simple theoretical model for erbium doped PCF ring lasers design  

NASA Astrophysics Data System (ADS)

In this paper a simple theoretical model is presented where the energy conservation principle is used. The model is based on semi-analytical equations describing the behaviour of an erbium-doped photonic crystal fibre (PCF) inside a ring laser. These semi-analytical equations allow the characterisation of the erbium-doped PCF. Spectral absorption and emission coefficients can be determined through the measurement of the gain in the PCF as a function of pump power attenuation for several fibre lengths by means of a linear fitting. These coefficients are proportional to the erbium concentration and to the corresponding absorption or emission cross section. So if the concentration is known the erbium cross sections can be immediately determined. The model was successfully checked by means of two different home-made erbium doped PCFs. Once the fibres were characterised the values of the spectral absorption and emission coefficients were used to simulate the behaviour of a back propagating ring laser made of each fibre. Passive losses of the components in the cavity were previously calibrated. A good agreement was found between simulated and experimental values of efficiency, pump power threshold and output laser power for a wide set of experimental situations (several values of the input pump power, output coupling factor, laser wavelength and fibre length).

Sánchez-Martín, J. A.; Álvarez, J. M.; Rebolledo, M. A.; Andrés, M. V.; Vallés, J. A.; Martín, J. C.; Berdejo, V.; Díez, A.

2011-08-01

198

Fabrication, structural characterization, dielectric and electrical parameters of the synthesized nano-crystalline erbium oxide  

NASA Astrophysics Data System (ADS)

Nano crystalline erbium oxide (Er2O3) was synthesized in the laboratory through sol-gel method. The effect of different annealing temperatures on the crystal structure has been studied using x-ray diffraction (XRD). The comparison of the specific surface area (s); calculated using Brunauer, Emmett & Teller theory and (XRD) results, was made and found in agreement with an approximate error of 7%. The morphology of the samples has been studied using scanning electron microscope (SEM) and particles are found having a spherical morphology. Elemental analysis of the erbium oxide was also carried using energy dispersive spectrum (EDS) of the synthesized samples. Fourier transform infrared spectrum (FTIR) of the prepared samples showed the characteristic peaks for Er2O3. The dielectric properties of Er2O3 were also studied in the wide range of frequency (100 Hz - 5MHz). The activation energy for erbium oxide was found to be between 0.5-0.8 eV in the temperature range of 373 K-573 K. Hall effect measurements were done on the synthesized erbium oxide and it was found that erbium oxide can have useful applications in the Hall effect sensors (HES).

Azad, Fahad; Maqsood, Asghari

2014-05-01

199

Comparaison de la soudabilite des alliages a base de nickel 152 et 182. (Comparison of hot cracking susceptibility of nickel base alloys 152 and 182).  

National Technical Information Service (NTIS)

182 weld metal (15% chromium) is sensitive to primary water stress corrosion cracking. In order to obtain a better corrosion resistance, INCO has developed a 30%-chromium content weld metal: INCONEL 152. Comparative weldability tests have been performed o...

D. Buisine P. Milleville

1994-01-01

200

Erbium ion implantation into different crystallographic cuts of lithium niobate  

NASA Astrophysics Data System (ADS)

Single crystals like lithium niobate are frequently doped with optically active rare-earth or transition-metal ions for a variety of applications in optical devices such as solid-state lasers, amplifiers or sensors. To exploit the potential of the Er:LiNbO 3, one must ensure high intensity of the 1.5 ?m luminescence as an inevitable prerequisite. One of the important factors influencing the luminescence properties of a lasing ion is the crystal field of the surrounding, which is inevitably determined by the crystal structure of the pertinent material. From that point it is clear that it cannot be easy to affect the resulting luminescence properties - intensity or position of the luminescence band - without changing the structure of the substrate. However, there is a possibility to utilise a potential of the ion implantation of the lasing ions, optionally accompanied with a sensitising one, that can, besides the doping, also modify the structure of the treated area od the crystal. This effect can be eventually enhanced by a post-implantation annealing that may help to recover the damaged structure and hence to improve the desired luminescence. In this paper we are going to report on our experiments with ion-implantation technique followed with subsequent annealing could be a useful way to influence the crystal field of LN. Optically active Er:LiNbO 3 layers were fabricated by medium energy implantation under various experimental conditions. The Er + ions were implanted at energies of 330 and 500 keV with fluences ranging from 1.0 × 10 15 to 1.0 × 10 16 ion cm -2 into LiNbO 3 single-crystal cuts of both common and special orientations. The as-implanted samples were annealed in air and oxygen at two different temperatures (350 and 600 °C) for 5 h. The depth concentration profiles of the implanted erbium were measured by Rutherford Backscattering Spectroscopy (RBS) using 2 MeV He + ions. The photoluminescence spectra of the samples were measured to determine the emission of 1.5 ?m. It has been shown that the projected range Rp of the implanted erbium depends on the beam energies of implantation. The concentration of the implanted erbium corresponds well with the fluence and is similar in all of the cuts of lithium niobate used. What was different were the intensities of the 1.5 ?m luminescence bands not only before and after the annealing but also in various types of the crystal cuts. The cut perpendicular to the cleavage plane <10-14> exhibited the best luminescence properties for all of the experimental conditions used. In order to study the damage introduced by the implantation process, the influence of the annealing procedure on the recovery of the host lattice was examined by RBS/channelling. The RBS/channelling method serves to determine the disorder density in the as-implanted surface layer.

Nekvindova, P.; Svecova, B.; Cajzl, J.; Mackova, A.; Malinsky, P.; Oswald, J.; Kolistsch, A.; Spirkova, J.

2012-02-01

201

Transmission electron microscopy study of erbium silicide formation from Ti/Er stack for Schottky contact applications.  

PubMed

In this paper, we present results of transmission electron microscopy studies on erbium silicide structures fabricated under various thermal conditions. A titanium cap has been used as a protective layer against oxidation during rapid thermal annealing of an erbium layer in a temperature range of 300-700 degrees C. Both layers (200 nm Ti and 25 nm Er) were deposited by electron-beam sputtering. The investigations have shown that the transformation of the 25-nm-thick erbium into erbium silicide is completed after annealing at 500 degrees C. At higher temperatures, the formation of a titanium silicide layer above erbium silicide is observed. The lowest Schottky barrier has been measured in the sample annealed at 700 degrees C. PMID:20500400

Ratajczak, J; ?aszcz, A; Czerwinski, A; Katcki, J; Phillipp, F; Van Aken, P A; Reckinger, N; Dubois, E

2010-03-01

202

Combination therapy: utilization of CO2 and Erbium:YAG lasers for skin resurfacing.  

PubMed

Skin resurfacing with carbon dioxide (CO2) lasers is a commonly used method for skin rejuvenation. With these lasers, there is substantial skin improvement with lessening of rhytids and skin discoloration, and noticeable skin tightening. However, there is also significant morbidity associated with their use. To decrease the healing and erythema times, other types of lasers have been developed. The author discusses the practice of combining the CO2 and Erbium:YAG lasers for limiting thermal injury. For deeper rhytids in the periorbital, perioral, and forehead regions, multiple passes with the CO2 laser are often the preferred treatment. For moderate rhytids, the CO2 laser can be used for the first pass followed by one to multiple passes with the Erbium:YAG laser. Erbium:YAG lasers when used alone are beneficial for removing fine wrinkles and discolorations. Combining these lasers results in both rhytid improvement and decreased morbidity. PMID:9972713

Collawn, S S

1999-01-01

203

Fast-tuning, low-noise, compact Brillouin/erbium fiber laser.  

PubMed

We demonstrate a fast-tuning Brillouin/erbium fiber laser (BEFL) using 4 m erbium-doped fiber (EDF) as both the Brillouin and erbium gain media. The BEFL frequency is fast tuned via modulating a piezoelectric transducer on which the EDF is coiled. Over 60 MHz frequency-tuning range is obtained at less than 5 V voltage amplitude and the tuning rates can achieve 48 kHz. This fast-tuning BEFL presents a low phase noise of -124 dB/Hz(1/2) at 1 kHz (normalized to 1 m interferometer optical path difference) with 32 kHz modulating frequency. It presents potential applications in fiber sensors and optical communications. PMID:24487900

Chen, Mo; Meng, Zhou; Tu, Xiaobo; Zhang, Yichi

2014-02-01

204

Photoluminescence in semiconductor structures based on butyl-substituted erbium phthalocyanine complexes  

SciTech Connect

The study is concerned with the luminescence properties of ensembles of semiconductor structures containing organic phthalocyanine molecules with erbium ions as complexing agents. The photoluminescence spectra of the structures of the type of erbium monophthalocyanine, bisphthalocyanine, and triphthalocyanine are recorded. The photoluminescence peaks are detected at the wavelengths 888, 760, and 708 nm (and photon energies 1.4, 1.6, and 1.75 eV) corresponding to electronic transitions within the organic complexes. It is found that, when a metal complexing agent is introduced into the molecular structure of the ligand, the 708 nm luminescence peak becomes unobservable. It is shown that, in the bisphthalocyanine samples, the photoluminescence signal corresponding to transitions from the 4F{sub 9/2} level of erbium ions is enhanced.

Belogorokhov, I. A., E-mail: jugqwerty@mail.ru; Ryabchikov, Yu. V.; Tikhonov, E. V.; Pushkarev, V. E.; Breusova, M. O.; Tomilova, L. G.; Khokhlov, D. R. [Moscow State University (Russian Federation)

2008-03-15

205

In vitro application of optical transmission systems in erbium:YAG laser temporomandibular joint surgery  

NASA Astrophysics Data System (ADS)

The experimental setup of this study is focused on the changes in temporomandibular joint tissue after irradiation with an Erbium:YAG laser. Initially, the free-running beam from the laser was focused onto freshly excised porcine tissue samples, indicating an optimum average energy density and pulse duration for the purpose of temporomandibular joint surgery of about 15 - 60 J/cm2 and 120 microsecond(s) - 240 microsecond(s) , respectively. Consecutively, an attempt was made to couple the Erbium:YAG laser beam on the one hand to optical fibers made of infrared-transmitting glasses (fluoride- and chalcogenide-based), on the other hand to a recently developed sapphire and liquid core fiber, respectively. From the preliminary observations of this investigation it appears that both the liquid core and the sapphire fiber are the most promising candidates for delivery of Erbium-YAG laser radiation in arthroscopic surgery of the craniomandibular articulation.

Nuebler-Moritz, Michael; Hering, Peter; Niederdellmann, Herbert; Deuerling, Christian; Dammer, Ralf

1995-05-01

206

Low-noise, single-frequency, single-polarization Brillouin/erbium fiber laser.  

PubMed

We demonstrate a low-noise Brillouin/erbium fiber laser (BEFL), which uses only 1.5 m polarization-maintaining erbium-doped fiber as both the Brillouin and erbium gain media. This BEFL presents a phase noise of -125 dB/Hz(1/2) at 1 kHz frequency, at 2 mW Brillouin pump (~3 MHz linewidth) power and 200 mW 980 nm pump power. The polarization extinction ratio of the laser output light is 31 dB. Stable (~2 h) single-mode operation is observed. This BEFL presents potential applications in distributed Brillouin fiber sensors, inteferometric fiber sensors, and optical communications. PMID:23938970

Chen, Mo; Meng, Zhou; Tu, Xiaobo; Zhou, Huijuan

2013-06-15

207

Erbium-doped photonic crystal fiber chaotic laser  

NASA Astrophysics Data System (ADS)

An erbium-doped photonic crystal fiber laser has been designed, constructed and characterized in order to examine the feasibility of this kind of devices for secure communications applications based on two identical chaotic lasers. Inclusion of a tailored photonic crystal fiber as active medium improves considerably the security of the device because it allows customization of the mode transversal profile, very influential on the laser dynamics and virtually impossible to be cloned by undesired listeners. The laser design has been facilitated by the combination of characterization procedures and models developed by us, which allow prediction of the most suitable laser features (losses, length of active fiber, etc.) to a given purpose (in our case, a laser that emits chaotically for a wide assortment of pump modulation conditions). The chaotic signals obtained have been characterized by means of topological analysis techniques. The underlying chaotic attractors found present topological structures belonging to classes of which very scarce experimental results have been reported. This fact is interesting from the point of view of the study of nonlinear systems and, besides, it is promising for secure communications: the stranger the signals, the more difficult for an eavesdropper to synthesize another system with similar dynamics.

Martín, Juan C.; Used, Javier; Sánchez-Martín, José A.; Berdejo, Víctor; Vallés, Juan A.; Álvarez, José M.; Rebolledo, Miguel A.

2011-08-01

208

Opto-electrical characterization of erbium-doped slot waveguides  

NASA Astrophysics Data System (ADS)

The convergence of photonics and microelectronics within a single chip is still lacking of a monolithical on-chip optical amplifier. Rare-earth doped slot waveguides show a large potential as on-chip source. Slot waveguides with silicon nanocrystals embedded in a dielectric host matrix can increase the light confinement in the active layer and allow electrical injection. In this work, horizontal slot waveguides formed by two thick silicon layers separated by a thin erbium doped silicon rich silicon oxide layer are studied as on-chip optical amplifiers. The waveguides are grown in a CMOS line with the active material grown by low-pressure chemical vapor deposition. Optical tests are performed and light propagation in the slot waveguides is observed. Using the cut-back technique, spectra propagation losses are evaluated. Room temperature electroluminescence is observed at 1.54 ?m. Transmitted optical signal resonant with Er absorption is studied as a function of the injected current for different probing laser wavelengths.

Tengattini, Andrea; Gandolfi, Davide; Marconi, Alessandro; Anopchenko, Oleksiy; Prtljaga, Nikola; Ramirez, Joan Manel; Ferrarese Lupi, Federico; Berencen, Yonder; Navarro Urrios, Daniel; Garrido, Blas; Fedeli, Jean-Marc; Rivallin, Pierrette; Surana, Kavita; Pavesi, Lorenzo

2012-05-01

209

Cavitation bubbles induced by Erbium lasers: implications for dentistry  

NASA Astrophysics Data System (ADS)

With new fiber systems available for 3 ?m, Erbium lasers become more interesting for precise tissue ablation in a water environment enabling new application in e.g. dentistry. The dynamics of explosive bubble formation was investigated at 2.78 ?m (Er,Cr;YSGG) and 2.94 ?m (Er:YAG), in relation to energy (10-50 mJ), pulse length (20-150 ?s) and fiber tip shape (flat or taper). The dynamics of exploding and imploding vapor bubbles were captured with high speed imaging (10 - 300 ?s range). Increasing the pulse length and energy, the vapor bubble became more elongated with an opaque surface for flat tip fibers. Tapered fibers produced spherical vapor bubbles with an optically transparent surface expected to be more forceful for creating mechanical effects in both hard and soft tissues. There was no significant difference between bubbles formed at 2.78 ?m (Er,Cr;YSGG) and 2.94 ?m (Er:YAG).

Verleng, Marja; Verdaasdonk, Rudolf; van der Veen, Albert; Lemberg, Vladimir; Boutoussov, Dmitri

2014-02-01

210

19 CFR 152.107 - Value if other values cannot be determined or used.  

Code of Federal Regulations, 2013 CFR

...Duties 2 2013-04-01 2013-04-01 false Value if other values cannot be determined or used. 152.107 Section...MERCHANDISE Valuation of Merchandise § 152.107 Value if other values cannot be determined or used....

2013-04-01

211

45 CFR 146.152 - Guaranteed renewability of coverage for employers in the group market.  

Code of Federal Regulations, 2013 CFR

...of coverage for employers in the group market. 146.152 Section 146.152 Public...REQUIREMENTS FOR THE GROUP HEALTH INSURANCE MARKET Provisions Applicable to Only Health...of coverage for employers in the group market. (a) General rule....

2013-10-01

212

Optical bistability in erbium-doped yttrium aluminum garnet crystal combined with a laser diode.  

PubMed

Optical bistability was observed in a simple structure of an injection laser diode combined with an erbium-doped yttrium aluminum garnet crystal. Since a hysteresis characteristic exists in the relationship between the wavelength and the injection current of a laser diode, an optical memory function capable of holding the output status is confirmed. In addition, an optical signal inversion was caused by the decrease of transmission of the erbium-doped yttrium aluminum garnet crystal against the red shift (principally mode hopping) of the laser diode. It is suggested that the switching time of this phenomenon is the time necessary for a mode hopping by current injection. PMID:20862016

Maeda, Y

1994-01-10

213

Influence of etching time on bond strength in dentin irradiated with erbium lasers  

Microsoft Academic Search

The purpose of this in vitro study was to evaluate the effect of etching time on the tensile bond strength (TBS) of a conventional\\u000a adhesive bonded to dentin previously irradiated with erbium:yttrium–aluminum–garnet (Er:YAG) and erbium, chromium:yttrium–scandium–gallium–garnet\\u000a (Er,Cr:YSGG) lasers. Buccal and lingual surfaces of 45 third molars were flattened until the dentin was exposed and randomly\\u000a assigned to three groups (n?=?30)

Leila Soares Ferreira; Christian Apel; Carlos Francci; Alyne Simoes; Carlos P. Eduardo; Norbert Gutknecht

2010-01-01

214

Coherent emission at 537 nm from IR-pumped erbium-doped silica microspheres.  

PubMed

Low pump threshold upconversion narrowband emission at 537 nm in a simple system of erbium-doped silica microsphere at the tip of a fiber is reported. The emission comes out radially (not from whispering gallery modes) and is strongly enhanced by a thin metal coating, in particular with platinum. This enhancement seems to be related to the coupling with surface plasmons. The emission wavelength does not correspond to any energy level differences of erbium in silica, and is the same that was reported earlier in a coated fiber. PMID:24562238

Pham, Van Hoi; Nguyen, The Anh; Ngo, Quang Minh; Coisson, Roberto

2014-02-15

215

Manufacture and properties of erythromycin beads containing neutron-activated erbium-171  

SciTech Connect

To evaluate the effects of a neutron activation radiolabeling technique on an enteric-coated multiparticulate formulation of erythromycin, test quantities were produced under industrial pilot scale conditions. The pellets contained the stable isotope erbium oxide (Er-170), which was later converted by neutron activation into the short-lived gamma ray-emitting radionuclide, erbium-171. In vitro studies indicated that the dissolution profile, acid resistance, and enteric-coated surface of the pellets were minimally affected by the irradiation procedure. Antimicrobial potency was also unaffected, as determined by microbiological assay. Neutron activation thus appears to simplify the radiolabeling of complex pharmaceutical dosage forms for in vivo study by external gamma scintigraphy.

Parr, A.F.; Digenis, G.A.; Sandefer, E.P.; Ghebre-Sellassie, I.; Iyer, U.; Nesbitt, R.U.; Scheinthal, B.M. (Univ. of Kentucky, Lexington (USA))

1990-03-01

216

The MicroRNA-148/152 Family: Multi-faceted Players  

PubMed Central

MicroRNAs(miRNA) are noncoding RNAs of about 19–23 nucleotides that are crucial for many biological processes. Members of the microRNA-148/152(miR-148/152) family, which include microRNA-148a(miR-148a), microRNA-148b(miR-148b), and microRNA-152(miR-152), are expressed differently in tumor and nontumor tissues and are involved in the genesis and development of disease. Furthermore, members of the miR-148/152 family are important in the growth and development of normal tissues. Members of the miR-148/152 family regulate target genes and are regulated by methylation of CPG islands. In this review, we report recent studies on the expression of members of the miR-148/152 family, methylation of CPG islands, and their target genes in different diseases, as well as in normal tissues.

2013-01-01

217

A theoretical analysis of amplification characteristics of bi-directional erbium-doped fiber amplifiers with single erbium-doped fiber  

Microsoft Academic Search

Based on the discussion of the structure scheme of bi-directional EDFA (Bi-EDFA) with single erbium-doped fiber (EDF) which can efficiently suppress the internal reflections, a rate equation model for the Bi-EDFA is developed to calculate the signal gain, pump absorption and output noise spectrum. The effects of numbers of signals, pumps of arbitrary direction, amplified spontaneous emission (ASE) and inherent

Qinghe Mao; Jingsong Wang; Xiaohan Sun; Mingde Zhang

1999-01-01

218

Fabrication and Characterization of Erbium-Doped Fluoropolymer Patterns via UV-Nanoimprint Lithography for Use in Planar Optical Amplifiers  

Microsoft Academic Search

The Er-doped precursor solutions were first prepared using 2,2,3,3,4,4,5,5-octafluoropentyl acrylate as a fluoromonomer, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol diacrylate as a cross-linking agent, poly(2,2,3,3,4,4,4-heptafluorobutyl acrylate) as a binding polymer, Darocure 4265 as radical photoinitiator and erbium(III) trifluoromethane sulfonate as an erbium source with various weight ratios. The crosslinked, patterned and erbium-doped fluoropolymer films were fabricated by UV-nanoimprint lithography on glass substrates for application as

Wook Hyun Kim; Myung-Seok Choi; Yoon Soo Han

2011-01-01

219

All-fiber phase actuator based on an erbium-doped fiber amplifier for coherent beam combining at 1064 nm.  

PubMed

Active phase control in fiber amplifiers is of considerable interest for low-noise single-frequency amplifiers and for coherent beam combining. We demonstrate phase control at 1064 nm by use of an erbium-doped fiber. We investigated the phase shift by guiding the beam through an erbium-doped fiber amplifier in a Mach-Zehnder configuration and applied the results to stabilize the relative phase of two ytterbium-doped fiber amplifiers. To the best of our knowledge, this is the first demonstration of an all-fiber coherent beam combining at 1064 nm employing an erbium-doped fiber as a phase actuator. PMID:21326418

Tünnermann, Henrik; Neumann, Jörg; Kracht, Dietmar; Wessels, Peter

2011-02-15

220

Growth studies of erbium-doped GaAs deposited by metalorganic vapor phase epitaxy using noval cyclopentadienyl-based erbium sources  

NASA Technical Reports Server (NTRS)

Erbium-doped GaAS layers were grown by metalorganic vapor phase epitaxy using two new sources, bis(i-propylcyclopentadienyl)cyclopentadienyl erbium and tris(t-butylcyclopentadienyl) erbium. Controlled Er doping in the range of 10(exp 17) - 10(exp 18)/cu cm was achieved using a relatively low source temperature of 90 C. The doping exhibits a second-order dependence on inlet source partial pressure, similar to behavior obtained with cyclopentadienyl Mg dopant sources. Equivalent amounts of oxygen and Er are present in 'as-grown' films indicating that the majority of Er dopants probably exist as Er-O complexes in the material. Er(+3) luminescence at 1.54 micrometers was measured from the as-grown films, but ion implantation of additional oxygen decreases the emission intensity. Electrical compensation of n-type GaAs layers codoped with Er and Si is directly correlated to the Er concentration is proposed to arise from the deep centers associated with Er which are responsible for a broad emission band near 0.90 micrometers present in the photoluminescence spectra of GaAs:Si, Er films.

Redwing, J. M.; Kuech, T. F.; Gordon, D. C.; Vaartstra, B. A.; Lau, S. S.

1994-01-01

221

Resonant Enhancement of Neutrinoless Double-Electron Capture in {sup 152}Gd  

SciTech Connect

In the search for the nuclide with the largest probability for neutrinoless double-electron capture, we have determined the Q{sub {epsilon}{epsilon}} value between the ground states of {sup 152}Gd and {sup 152}Sm by Penning-trap mass-ratio measurements. The new Q{sub {epsilon}{epsilon}} value of 55.70(18) keV results in a half-life of 10{sup 26} yr for a 1 eV neutrino mass. With this smallest half-life among known 0{nu}{epsilon}{epsilon} transitions, {sup 152}Gd is a promising candidate for the search for neutrinoless double-electron capture.

Eliseev, S.; Roux, C. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Blaum, K. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Physikalisches Institut, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Block, M.; Herfurth, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Droese, C.; Schweikhard, L. [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Kluge, H.-J. [Physikalisches Institut, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Krivoruchenko, M. I. [Institute for Theoretical and Experimental Physics, 117218 Moscow (Russian Federation); Novikov, Yu. N. [PNPI, Gatchina, 188300 St. Petersburg (Russian Federation); Minaya Ramirez, E. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Helmholtz-Institut Mainz, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Shabaev, V. M.; Tupitsyn, I. I.; Zubova, N. A. [Department of Physics, St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Simkovic, F. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Department of Nuclear Physics and Biophysics, Comenius University, 84248 Bratislava (Slovakia); Zuber, K. [Institut fuer Kern- und Teilchenphysik, Technische Universitaet, 01069 Dresden (Germany)

2011-02-04

222

Resonant enhancement of neutrinoless double-electron capture in 152Gd.  

PubMed

In the search for the nuclide with the largest probability for neutrinoless double-electron capture, we have determined the Q(??) value between the ground states of (152)Gd and (152)Sm by Penning-trap mass-ratio measurements. The new Q(??) value of 55.70(18) keV results in a half-life of 10(26)??yr for a 1 eV neutrino mass. With this smallest half-life among known 0??? transitions, (152)Gd is a promising candidate for the search for neutrinoless double-electron capture. PMID:21405389

Eliseev, S; Roux, C; Blaum, K; Block, M; Droese, C; Herfurth, F; Kluge, H-J; Krivoruchenko, M I; Novikov, Yu N; Minaya Ramirez, E; Schweikhard, L; Shabaev, V M; Simkovic, F; Tupitsyn, I I; Zuber, K; Zubova, N A

2011-02-01

223

Ablation of Bone and Methacrylate by a Prototype Mid-Infrared Erbium: YAG Laser.  

National Technical Information Service (NTIS)

An erbium: YAG laser was used to generate 200 microsec pulses of mid-infrared 2.94 micrometer light in both the single and multimode configurations. Laser pulses were focused on the surfaces of both rabbit long bones and methacrylate blocks, and the tissu...

J. S. Nelson L. Yow L. H. Liaw L. Macleay R. B. Zavar

1988-01-01

224

High repetition frequency, fundamentally mode-locked 111 fs all-fiber erbium laser  

Microsoft Academic Search

In this paper passively mode-locked erbium doped fiber laser is described. With all-fiber cavity configuration 169 MHz fundamental repetition frequency and average output power of more than 30 mW were achieved. Output frequency comb spectrum of 28.5 nm and 111 fs pulses were obtained.

Michal P. Nikodem; Krzysztof M. Abramski

2009-01-01

225

Erbium-Doped Fiber Lasers Operated in a Strong Normal Dispersion Regime at Low Repetition Rate  

Microsoft Academic Search

We report on a passively mode-locked erbium-doped fiber laser with a repetition rate as low as 1.2 MHz in a strong normal dispersion regime. The laser was mode locked via spectral filtering. It generated a pulse with large and linear chirp that can be dechirped to 430 fs outside the cavity.

Yue Cai; Chun Zhou; Meng Zhang; Lingling Chen; Yunfeng Ma; Zhongwei Fan; Gang Niu; Jin Yu; Yang Liu; Xue Zhang; Zhigang Zhang

2010-01-01

226

Scénarios dynamiques d'une fibre dopée erbium fonctionnant sur deux longueurs d'onde  

NASA Astrophysics Data System (ADS)

Nous montrons la sensibilité à l'anisotropie de pompe des diagrammes de bifurcation d'une fibre dopée erbium fonctionnant sur deux longueurs d'onde. Un très bon accord entre les diagrammes de bifurcation expérimentaux et ceux obtenus théoriquement a été obtenu. De nouveaux types de bistabilités (3T-chaos et IT-chaos) sont mis en évidence pour ces systèmes.

Bérisson, W.; Besnard, P.; Ginovart, F.; Le Boudecl, P.; Sanchez, F.; Stéphan, G. M.

2002-06-01

227

A numerical model for the complex susceptibility of saturated erbium-doped amplifiers  

Microsoft Academic Search

A detailed model for the complex susceptibility behavior of erbium-doped amplifiers, which applies in the saturation regime of operation, is presented. The model takes into account the effective individual laser transitions between the upper and lower manifolds. The model is based on a curve fitting algorithm that fits the emission and absorption cross section with Voigt lineshapes, which correspond to

Kamal E. Alameh; Robert A. Minasian

1997-01-01

228

Spectroscopic analysis of erbium doped laser-induced crystals for fiber-laser applications  

NASA Astrophysics Data System (ADS)

Laser induced crystallization of glasses is a highly spatially selective process which could be used to produce crystalline-core optical fibers for fiber-laser applications. Toward this goal, single crystal lines were ``written'' in Er:LaBGeO5 glass using a femtosecond pulsed laser. These structures were analyzed using micro-Raman and luminescence spectroscopy in order to determine their viability as waveguiding laser gain media. Two-dimensional scans reveal that the erbium fluorescence is inhomogeneous over the cross-section of the crystal and lacks spatial coordination with the Raman emission, implying a physical ion accumulation in addition to enhancement due to the crystal field. Additionally, erbium fluorescence spectra taken at low temperatures from polycrystals with varying concentrations of erbium were compared to those from the laser-induced crystal lines. Significant differences in the emission energies and intensity ratios of the erbium peaks were observed. These differences may be due to the presence of strain, grain boundaries, or charge resulting from the different crystallization processes used.

Knorr, Brian; Stone, Adam; Jain, Himanshu; Dierolf, Volkmar

2013-03-01

229

Erbium:YAG laser contouring of the nasal dorsum: a preliminary investigation  

NASA Astrophysics Data System (ADS)

In conventional aesthetic rhinoplasty operations, manual or powered rasps are used to reduce the osseo-cartilagenous nasal dorsum. This tactile method requires palpation of the instrument and the dorsum during surgery to estimate the degree of volume reduction, and often requires forceful manipulation of the dorsum which may illicit pain during surgery and contribute to post-operative edema and echymosis. In this preliminary study, we investigated the use of the Erbium:YAG laser ((lambda) equals294 micrometers ) to reduce bone and cartilage using ex-vivo porcine nasal dorsum and human cadaveric tissues. The short pulsed length and high absorption of this laser in biologic tissues results in minimization of thermal injury which are ideal for non- contact optical contouring of osseous and cartilagenous tissues in the face. Two Erbium:YAG lasers were used to ablate fresh porcine nasal bone and compared for their use. One Erbium:YAG laser, the Fidelis Laser, Fontana Medical Lasers, Ljubljana, Slovenija with variable pulse repetition rates (2 to 50 Hz), pulse energy (80 to 1000 mJ), and pulse duration (100, 300, 750 and 1000 microsecond(s) ) was used and compared to the Ultrafine Erbium:YAG laser, Coherent Inc., Santa Clara California, with variable pulse repetition rate (2 to 10 Hz), pulse energy (2-16 J/cm2), and spot diameter (2-6 mm). Only laser parameters approximating the conditions for thermal confinement were evaluated.

Truong, Mai T.; Majaron, Boris; Pandhoh, Nidhi; Wong, Brian J.

2001-05-01

230

Broad-band injection seeding of an erbium-doped fiber ring laser  

Microsoft Academic Search

We present a broad-band (40 MHz) injection-seeded erbium-doped fiber ring laser with a low finesse cavity. Broad-band operation is achieved by seeding an arbitrary number of longitudinal modes in this cavity. This fiber laser is advantageous because it has the potential to substantially suppress stimulated Brillouin scattering for lidar applications.

Chirantan Mukhopadhyay; Peter D. Dragic

2005-01-01

231

Holmium:YAG and erbium:YAG laser interaction with hard and soft tissue  

Microsoft Academic Search

The holmium YAG and erbium YAG lasers operating at 2.1 micrometers and 2.9 micrometers respectively, are the subject of great interest for various medical applications. The interaction of both these pulsed lasers with biological tissue involves absorption of the radiation by water leading to rapid heating and ablation, however the different absorption coefficients at these two wavelengths give rise to

Andrew Charlton; Mark R. Dickinson; Terence A. King; Anthony J. Freemont

1991-01-01

232

Room temperature multifrequency erbium-doped fiber lasers anchored on the ITU frequency grid  

Microsoft Academic Search

Room temperature multifrequency erbium-doped fiber (EDF) lasers anchored on the ITU frequency grid and using frequency periodic filters are presented. The multifrequency operation is demonstrated both theoretically and experimentally by adding a frequency shifter in the ring cavity to prevent steady-state laser operation and single-frequency oscillation

Antoine Bellemare; Miroslav Karasek; Martin Rochette; S. LRochelle; Michel Têtu

2000-01-01

233

Average inversion level, modeling, and physics of erbium-doped fiber amplifiers  

Microsoft Academic Search

We present a detailed study of a set of models for characterizing the gain, the input and output powers of single erbium-doped fiber amplifiers (EDFAs) and networks of EDFAs. The time dependent gain is described by a single ordinary differential equation for the average inversion level of an EDFA with arbitrary number of signal channels with arbitrary power levels and

Y. Sun; J. L. Zyskind; A. K. Srivastava

1997-01-01

234

Multiwavelength generation in an erbium-doped fiber laser using in-fiber comb filters  

Microsoft Academic Search

Simultaneous continuous wave multiwavelength operation of an erbium-doped fiber laser has been demonstrated using two types of recently developed in-fiber grating comb filters. The lasing wavelengths and linewidths were determined by the comb filter, which was inserted in a ring cavity with a single inhomogeneously broadened gain medium.

Jong Chow; Graham Town; Ben Eggleton; Morten Ibsen; Kate Sugden; Ian Bennion

1996-01-01

235

Calculated Groundstate Properties of Erbium Isotopes in Comparison with Measured 2+-STATES  

NASA Astrophysics Data System (ADS)

The deformation properties of nuclei in the vicinity of Erbium are calculated within the relativistic mean-field and the Skyrme-Hartree-Fock model and compared to experimentally measured 2+-states. The investigation in this region is of special interest since the lowest 2+-energy of an isotope-chain is not located in the midshell region.

Cornelius, T.; Maruhn, J. A.; Greiner, W.; Fleischer, P.; Reinhard, P.-G.; Bürvenich, T.; Bender, M.; Schramm, S.; Hamilton, J. H.

2003-10-01

236

Resonantly Pumped, Erbium-Doped, 2.8 Micron Solid State Laser With High Slope Efficiency.  

National Technical Information Service (NTIS)

A laser system and method for producing a laser emission at a wavelength of substantially 2.8 microns is disclosed. In a preferred embodiment of the invention, the laser system comprises a crystal having a host material doped with erbium; a laser cavity d...

L. Esterowtiz R. C. Stoneman

1991-01-01

237

The interaction of palladium with cobalt and erbium at 600°C  

Microsoft Academic Search

The interaction of the components in the Er–Co–Pd system at 600°C was investigated over the composition range 0–50 at% of erbium by X-ray powder, metallography, electron probe microanalysis (EPMA), DTA and SEM. The isothermal section at 600°C was determined based on these results.

J. I Rousnyak; N. A Tinikashvili; M. V Raevskaya; A. V Gribanov

2001-01-01

238

Performance of a High-Concentration Erbium-Doped Fiber Amplifier with 100 nm Amplification Bandwidth  

SciTech Connect

Increasing demand for higher bandwidth has driven the need for higher Wavelength Division Multiplexing (WDM) channels. One of the requirements to achieve this is a broadband amplifier. This paper reports the performance of a broadband, compact, high-concentration and silica-based erbium-doped fiber amplifier. The amplifier optimized to a 2.15 m long erbium-doped fiber with erbium ion concentration of 2000 ppm. The gain spectrum of the amplifier has a measured amplification bandwidth of 100 nm using a 980 nm laser diode with power of 150 mW. This silica-based EDFA shows lower noise figure, higher gain and wider bandwidth in shorter wavelengths compared to Bismuth-based EDFA with higher erbium ion concentration of 3250 ppm at equivalent EDF length. The silica-based EDF shows peak gain at 22 dB and amplification bandwidth between 1520 nm and 1620 nm. The lowest noise figure is 5 dB. The gain is further improved with the implementation of enhanced EDFA configurations.

Hajireza, P.; Shahabuddin, N. S.; Abbasi-Zargaleh, S.; Emami, S. D.; Abdul-Rashid, H. A.; Yusoff, Z. [Center for Advanced Devices and Systems, Faculty of Engineering, Multimedia University, 63100 Cyberjaya (Malaysia)

2010-07-07

239

Healing of bone in the rat following surgery with the erbium-YAG laser  

Microsoft Academic Search

Background and objectives: the aim of this study was to examine the pattern of healing in rat calvarial defects prepared with the erbium-YAG laser, using the 'guided tissue regeneration' technique. Materials and method: PTFE membranes were placed over lased skull defects, and the skin wounds sutured. Rats were killed humanely at intervals after surgery, and the skulls processed for paraffin

Mark R. Dickinson; Hugh Devlin; Monsour A. El Montaser; P. Sloan

1996-01-01

240

Some theoretical investigations on prompt self-powered neutron detectors (hafnium and erbium emitters)  

Microsoft Academic Search

For noise analysis experiments in nuclear reactors, some self-powered neutron detectors with prompt neutron reactions (hafnium and erbium emitters) are investigated. Calculations of neutron physical characteristics using the program REND were carried out. Calculation of the neutron self-shielding factor, the neutron flux depression factor, and the total correction for choice geometry dimensions are shown. Absolute currents and detector sensitivities are

N. A. Antonov; Y. D. Yordanov

1986-01-01

241

Performance comparison of Zr-based and Bi-based erbium-doped fiber amplifiers.  

PubMed

In this Letter, we present a comprehensive comparison of the performance of a zirconia-based erbium-doped fiber amplifier (Zr-EDFA) and a bismuth-based erbium-doped fiber amplifier (Bi-EDFA). The experimental results reveal that a Zr-EDFA can achieve comparable performance to the conventional Bi-EDFA for C-band and L-band operations. With a combination of both Zr and Al, we could achieve a high erbium-doping concentration of about 2800 ppm (parts per million) in the glass host without any phase separations of rare earths. The Zr-based erbium-doped fiber (Zr-EDF) was fabricated using in a ternary glass host, zirconia-yttria-aluminum codoped silica fiber through a solution-doping technique along with modified chemical vapor deposition. At a high input signal of 0 dBm, a flat gain at average value of 13 dB is obtained with a gain variation of less than 2 dB within the wavelength region of 1530-1575 nm and using 2 m of Zr-EDF and 120 mW pump power. The noise figures are less than 9.2 at this wavelength region. It was found that a Zr-EDFA can achieve even better flat-gain value and bandwidth as well as lower noise figure than the conventional Bi-EDFA. PMID:20808356

Paul, M C; Harun, S W; Huri, N A D; Hamzah, A; Das, S; Pal, M; Bhadra, S K; Ahmad, H; Yoo, S; Kalita, M P; Boyland, A J; Sahu, J K

2010-09-01

242

Effects of erbium additions on high temperature performance of high power Ni-MH batteries  

Microsoft Academic Search

The Co(?)-coated spherical nickel hydroxide powder is optimum as positive electrode of high power Ni-MH battery because of its excellent property. But the performances at high temperature (above 50 ?) is still not satisfied. In the present paper, the effect of element erbium, used as additive by different methods to prepare positive electrode, on the high temperature performances of the

XIE Shou-yun; CHENG Yan; JIAN Xu-yu; ZHU Lei; CHEN Hui; WANG Zhong

243

Nanocrystalline erbium oxide powders synthesized by the solid-state method from carbonates, oxalates, and hydroxides  

Microsoft Academic Search

Nanocrystalline erbium oxide powders are synthesized by the solid-state method from carbonates, oxalates, and hydroxides.\\u000a Depending on the prehistory of their preparation, the average particle size decreases in the series: oxalates > carbonates\\u000a > hydroxides; being 10 to 20 nm at a thermal treatment temperature of 680°C

A. A. Titov; M. A. Klimenko; N. L. Opolchenova; Z. V. Eremenko; N. N. Stepanova; E. B. Mikhlin

2009-01-01

244

25 CFR 224.152 - Must the Secretary always reassume the activities upon a finding of imminent jeopardy to a...  

Code of Federal Regulations, 2011 CFR

...224.152 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS TRIBAL ENERGY RESOURCE AGREEMENTS UNDER THE INDIAN TRIBAL ENERGY DEVELOPMENT AND SELF DETERMINATION ACT Reassumption § 224.152...

2011-04-01

245

76 FR 27865 - Airworthiness Directives; Cessna Aircraft Company Models 150, 152, 170, 172, 175, 177, 180, 182...  

Federal Register 2010, 2011, 2012, 2013

...2120-AA64 Airworthiness Directives; Cessna Aircraft Company Models 150, 152, 170, 172...airworthiness directive (AD) for Cessna Aircraft Company (Cessna) 150, 152, 170...Aerospace Engineer, ACE- 118W, Wichita Aircraft Certification Office (ACO), 1801...

2011-05-13

246

25 CFR 152.17 - Sales, exchanges, and conveyances by, or with the consent of the individual Indian owner.  

Code of Federal Regulations, 2011 CFR

...152.17 Section 152.17 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

247

25 CFR 152.18 - Sale with the consent of natural guardian or person designated by the Secretary.  

Code of Federal Regulations, 2011 CFR

...152.18 Section 152.18 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

248

25 CFR 152.22 - Secretarial approval necessary to convey individual-owned trust or restricted lands or land owned...  

Code of Federal Regulations, 2011 CFR

...152.22 Section 152.22 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS Sales, Exchanges and...

2011-04-01

249

Synthesis and structure of a dimeric hydroxobridged erbium(III) complex, di-?-hydroxo-bis[(1,4,7,10,13,16-hexaazacyclooctadecane) erbium(III)] tetra(trifloromethanesulfonate)  

Microsoft Academic Search

The title complex was synthesized by the reaction of 1,4,7,10,13,16-hexaazacyclooctadecane abbreviated as hexacyclen) with erbium(III) trifloromethanesulfonate in 1:1 (molar ratio) in acetonitrile under nitrogen. The crystal structure determination shows that the complex is dinuclear with two erbium ions bridged by two hydroxide ions. Each of the two metal ions is coordinated similarly by the two bridging hydroxide groups and six

Rui-Yao Wang; Jian-Jun Zhao; Tian-Zhu Jin; Guang-Xian Xu; Zhong-Yuan Zhou; Xiang-Ge Zhou

1998-01-01

250

Syntheses and Cellular Investigations of 173-, 152- and 131-Amino Acid Derivatives of Chlorin e61  

PubMed Central

A series of amino acid conjugates of chlorin e6, containing lysine or aspartic acid residues in positions 173, 152 or 131 of the macrocycle were synthesized and investigated as photosensitizers for photodynamic therapy of tumors. All three regioisomers were synthesized in good yields and in 5 steps or less from pheophytin a (1). In vitro investigations using human carcinoma HEp2 cells show that the 152-lysyl regioisomers accumulate the most within cells, and the most phototoxic are the 131 regioisomers. The main determinant of biological efficacy appears to be the conjugation site, probably because of molecular conformation. Molecular modeling investigations reveal that the 173-substituted chlorin e6 conjugates are L-shaped, the 152 and 131 regioisomers assume extended conformations, and the 131 derivatives are nearly linear. It is hypothesized that the 131-aspartylchlorin e6 conjugate may be a more efficient photosensitizer for PDT than the commercial currently used 152 derivative.

Waruna Jinadasa, R. G.; Hu, Xiaoke; Vicente, M. Graca H.; Smith, Kevin M.

2011-01-01

251

40 CFR 152.112 - Approval of registration under FIFRA sec. 3(c)(5).  

Code of Federal Regulations, 2013 CFR

...CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES Agency Review of Applications § 152.112...directions for use on food, animal feed, or food or feed crops, or if the intended use of the pesticide results or...

2013-07-01

252

19 CFR 152.104 - Transaction value of identical merchandise and similar merchandise.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Transaction value of identical merchandise and similar merchandise...Merchandise § 152.104 Transaction value of identical merchandise and similar merchandise. (a) General. The transaction value of identical merchandise, or of...

2013-04-01

253

Cep152 acts as a scaffold for recruitment of Plk4 and CPAP to the centrosome  

PubMed Central

Both gain and loss of function studies have identified the Polo-like kinase Plk4/Sak as a crucial regulator of centriole biogenesis, but the mechanisms governing centrosome duplication are incompletely understood. In this study, we show that the pericentriolar material protein, Cep152, interacts with the distinctive cryptic Polo-box of Plk4 via its N-terminal domain and is required for Plk4-induced centriole overduplication. Reduction of endogenous Cep152 levels results in a failure in centriole duplication, loss of centrioles, and formation of monopolar mitotic spindles. Interfering with Cep152 function prevents recruitment of Plk4 to the centrosome and promotes loss of CPAP, a protein required for the control of centriole length in Plk4-regulated centriole biogenesis. Our results suggest that Cep152 recruits Plk4 and CPAP to the centrosome to ensure a faithful centrosome duplication process.

Cizmecioglu, Onur; Arnold, Marc; Bahtz, Ramona; Settele, Florian; Ehret, Lena; Haselmann-Weiss, Uta; Antony, Claude

2010-01-01

254

43 CFR 15.2 - Removal or destruction of natural features and marine life.  

Code of Federal Regulations, 2013 CFR

...Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.2 Removal or...beach sand, gravel or minerals, corals, sea feathers and fans, shells...contrivance shall be attached to any coral, rock or other formation,...

2013-10-01

255

40 CFR 81.152 - Southern Coastal Plain Intrastate Air Quality Control Region.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Southern Coastal Plain Intrastate Air Quality Control Region...Regions § 81.152 Southern Coastal Plain Intrastate Air Quality Control Region. The Southern Coastal Plain Intrastate Air Quality Control...

2013-07-01

256

HABS TEX,152LUBBO,12 (sheet 2 of 2) "U Lazy S" ...  

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

HABS TEX,152-LUBBO,12- (sheet 2 of 2) - "U Lazy S" Carriage, Saddle & Harness House, National Ranching Heritage Center (moved from West Farm Road 669, South of Post, Garza County, TX), Lubbock, Lubbock County, TX

257

HABS TEX,152LUBBO,12 (sheet 1 of 2) "U Lazy S" ...  

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

HABS TEX,152-LUBBO,12- (sheet 1 of 2) - "U Lazy S" Carriage, Saddle & Harness House, National Ranching Heritage Center (moved from West Farm Road 669, South of Post, Garza County, TX), Lubbock, Lubbock County, TX

258

40 CFR 96.152 - Responsibilities of CAIR authorized account representative.  

Code of Federal Regulations, 2013 CFR

...CAIR NOX AND SO 2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR NOX Allowance Tracking System § 96.152 Responsibilities of CAIR...establishment of a CAIR NOX Allowance Tracking System account, all submissions to the...

2013-07-01

259

Residual 152Eu and 60Co activities induced by neutrons from the Hiroshima atomic bomb  

Microsoft Academic Search

Specific activities of 152Eu:Eu in stone samples exposed to the Hiroshima atomic bomb were determined for 70 samples up to a 1,500-m slant range from the epicenter. The specific activities of 60Co:Co were also determined for six samples near the Hiroshima hypocenter. First, the 152Eu data were investigated to find out the directional dependence of neutron activation. Directional anisotropy was

Kiyoshi Shizuma; Kazuo Iwatani; Hiromi Hasai; Masaharu Hoshi; Takamitsu Oka; Hiroshige Morishima

1993-01-01

260

Swift Observations of MAXI J1659-152: A Compact Binary with a Black Hole Accretor  

Microsoft Academic Search

We report on the detection and follow-up high-cadence monitoring observations of MAXI J1659-152, a bright Galactic X-ray binary transient with a likely black hole accretor, by Swift over a 27 day period after its initial outburst detection. MAXI J1659-152 was discovered almost simultaneously by Swift and the Monitor of All-sky X-ray Image on 2010 September 25, and was monitored intensively

J. A. Kennea; P. Romano; V. Mangano; A. P. Beardmore; P. A. Evans; P. A. Curran; H. A. Krimm; C. B. Markwardt; K. Yamaoka

2011-01-01

261

Effects of heat treatment and concentration on the luminescence properties of erbium-doped silica sol–gel films  

Microsoft Academic Search

Erbium-doped sol–gel films with different Er concentrations were formed by spin-coating a solution of erbium-nitrate, tetra-ethoxy-silane (TEOS), ethanol, water and HCl on a Si substrate. Refractive index, film thickness and composition were measured as a function of Er concentration. The Er\\/Si ratio in the film is roughly proportional to the Er\\/Si ratio in solution, while the Si\\/O ratio varies with

L. H Slooff; M. J. A de Dood; A van Blaaderen; A Polman

2001-01-01

262

Microscopic structure and energy transfer of vacancy-related defect pairs with Erbium in wide-gap semiconductors  

Microsoft Academic Search

Electron Paramagnetic Resonance (EPR) measurements of Erbium-doped 6H–SiC and wurtzite GaN samples are compared to total energy calculations based on density functional theory (DFT) in order to investigate the well-known luminescence of the intra 4f-shell transition at 1540nm, useful in light-emitting diodes or lasers. The highly correlated f-electrons of Erbium (Er) have been treated within an LDA+U approach. We discus

A. Konopka; S. Greulich-Weber; V. Dierolf; H. X. Jiang; U. Gerstmann; E. Rauls; S. Sanna; W. G. Schmidt

2011-01-01

263

Coprecipitation of heavy metals with erbium hydroxide for their flame atomic absorption spectrometric determinations in environmental samples  

Microsoft Academic Search

Trace amounts of copper, manganese, cobalt, chromium, iron and lead were quantitatively coprecipitated with erbium hydroxide on 0.05M NaOH medium. The coprecipitant could be easily dissolved with 1M nitric acid. The presence of up to 15g\\/l of erbium ions did not interfere with the atomic absorption spectrometric determination of analyte ions. The recovery values for analyte ions were higher than

Mustafa Soylak; Sibel Saracoglu; Umit Divrikli; Latif Elci

2005-01-01

264

Surface segregation effects of erbium in GaAs growth and their implications for optical devices containing ErAs nanostructures  

Microsoft Academic Search

We report on the integration of semimetallic ErAs nanoparticles with high optical quality GaAs-based semiconductors, grown by molecular beam epitaxy. Secondary ion mass spectrometry and photoluminescence measurements provide evidence of surface segregation and incorporation of erbium into layers grown with the erbium cell hot, despite the closed erbium source shutter. We establish the existence of a critical areal density of

Adam M. Crook; Hari P. Nair; Seth R. Bank

2011-01-01

265

Isothermal section of the erbium-chromium-boron system at 1270/sup 0/C  

SciTech Connect

This paper studies the phase equilibria and crystal structure of the ternary compounds in the Er-Cr-B system. The specimens for the investigation were prepared from powders of chromium and boron and compact erbium. The heat treatment of the alloys consisted of annealing at 1270 K in quartz ampuls sealed under vacuum and subsequent hardening in cold water. The phase composition of the as-cast and annealed specimens was determined by the x-ray diffraction method on powder. The results of the investigation confirmed the existence of the earlier-found ErCrB/sub 4/ boride and detected a new boride with a composition of Er/sub 3/CrBr/sub 7/. The character of interaction is complicated in replacement of yttrium (or gadolinium) by erbium.

Ghaban, N.F.; Datsyna, V.N.

1986-06-01

266

Stabilization of a multiwavelength erbium-doped fiber laser using a nonlinear silicon waveguide  

NASA Astrophysics Data System (ADS)

We propose and demonstrate a multiwavelength erbium-doped fiber laser stabilized by four-wave mixing (FWM) in a nonlinear silicon-on-insulator (SOI) waveguide. The optical gain was provided by an erbium-doped fiber amplifier, and the wavelength selectivity was achieved by a Fabry-Pérot comb filter in the ring cavity. The FWM in the SOI waveguide was enhanced by applying a reverse-biased p-i-n diode structure to reduce free-carrier absorption. Making use of the nonlinearity of the SOI waveguide, a multiwavelength laser with six output wavelengths at 0.8 nm spacing was achieved. The power difference among modes was equalized within a range of 1.8 dB. The power fluctuation of each mode was stabilized to <0.65 dB during 20 min observation at room temperature.

Wong, Chi Yan; Tong, F. W.; Cheng, Zhenzhou; Xu, Ke; Chen, Yi Min; Tsang, Hon Ki

2014-03-01

267

Novel Numerical Method to Model Multichannel Erbium-Doped Fiber Amplifier  

NASA Astrophysics Data System (ADS)

We propose a novel numerical method based on genetic algorithm (GA) to solve the evolution equations that are the basis of modeling multichannel erbium-doped fiber amplifiers (EDFAs). The evolution equations are first transformed from an iteration problem to an optimization problem. The unknown parameter related to backward amplified spontaneous emission (BASE) is coded into a string of bits based on their probable lower and upper limits. By defining proper random variation operators and cost function, the coupled evolution equations are optimized using GA for different values of erbium-doped fiber parameters. It is observed that GA is an efficient method for analyzing the EDFA characteristics in the entire C-band.

Priye, Vishnu; Singh, Dharmendra K.; Arya, Subhash C.

268

Optimization of resonantly cladding-pumped erbium-doped fiber amplifiers for space-borne applications.  

PubMed

Lasers for use in space-borne applications require ultrahigh efficiency due to limited heat dissipation and power generation capacity. In particular, interplanetary optical communication systems require high-efficiency, moderate-power (>4 W) optical transmitters in the 1600 nm wavelength range. Resonantly pumped dual-clad erbium-doped fiber lasers are best suited for this purpose. Parametric numerical optimizations are performed using a two-level propagation model modified to include spatial effects specific to large-mode-area fibers. Propagation loss mechanisms are found to be limiting factors due to the relatively low cross-sections and low quenching-free doping densities of erbium. Although experimental reports have demonstrated efficiencies up to 33%, simulation results indicate that over 53% power-conversion efficiency can be achieved using commercial fibers, and over 75% can be achieved using custom fibers employing propagation-loss mitigation strategies. PMID:23759839

Yao, Haomin; Wright, Malcolm W; Marciante, John R

2013-06-10

269

Lead test fuel assembly physics for erbium fuel at the San Onofre Nuclear Generating Station  

SciTech Connect

ABB Combustion Engineering Nuclear Fuel (ABB C-E) has completed a qualification program for the use of Er[sub 2]O[sub 3] as a burnable absorber in pressurized water reactors. Neutronic properties and performance have been assessed in a development program that included the following: 1. evaluation and processing of basic cross-section data for naturally occurring erbium isotopes and capture/decay products of erbium and thulium; 2. performance of critical experiments by ABB C-E, Rensselaer Polytechnic Institute, and Southern California Edison (SCE); 3. comparison of methods between ABB C-E and SCE (Ref. 6); and 4. irradiation of lead test fuel assemblies (LTAs) and corefollow analyses in collaboration between ABB C-E and SCE (16 x 16 fuel) and Baltimore Gas Electric Company (14 x 14 fuel). The subject of this paper is the physics core-follow results for San Onofre unit 2.

Gavin, P.H.; Jonsson, A. (ABB Combustion Engineering Nuclear Power, Inc., Windsor, CT (United States)); Swoope, S.; Chang, R.Y.; Thomsen, O.J. (Southern California Edison, Irvine (United States))

1993-01-01

270

Tunable multiwavelength L-band Brillouin-Erbium fiber laser utilizing passive EDF absorber section  

NASA Astrophysics Data System (ADS)

We demonstrate a simple tunable L-band multiwavelength Brillouin-Erbium fiber laser that utilizes a short passive erbium doped fiber (PEDF) as an absorber section. The impact of including the PEDF absorber section on the laser tunability is investigated. The proposed laser structure exhibits a wide tuning range of 24.4 nm (from 1583.5 nm to 1607.9 nm) at 1480 nm pump and Brillouin pump powers of 100 and 4 mW, respectively. This tuning range represents a 31% increase compared with a laser without a PEDF absorber section. The average number of stable output channels produced within this wavelength range is 16 channels with a spacing of 0.089 nm.

Al-Mashhadani, T. F.; Al-Mansoori, M. H.; Jamaludin, M. Z.; Abdullah, F.; Abass, A. K.; Rawi, N. I. M.

2013-12-01

271

CMOS-compatible 75??mW erbium-doped distributed feedback laser.  

PubMed

On-chip, high-power, erbium-doped distributed feedback lasers are demonstrated in a CMOS-compatible fabrication flow. The laser cavities consist of silicon nitride waveguide and grating features, defined by wafer-scale immersion lithography and an erbium-doped aluminum oxide layer deposited as the final step in the fabrication process. The large mode size lasers demonstrate single-mode continuous wave operation with a maximum output power of 75 mW without any thermal damage. The laser output power does not saturate at high pump intensities and is, therefore, capable of delivering even higher on-chip signals if a stronger pump is utilized. The amplitude noise of the laser is investigated and the laser is shown to be stable and free from self-pulsing when the pump power is sufficiently above threshold. PMID:24875988

Hosseini, Ehsan Shah; Purnawirman, Purnawirman; Bradley, Jonathan D B; Sun, Jie; Leake, Gerald; Adam, Thomas N; Coolbaugh, Douglas D; Watts, Michael R

2014-06-01

272

1.54 micron Emission from Erbium implanted GaN for Photonic Applications  

NASA Technical Reports Server (NTRS)

The development of efficient and compact light sources operating at 1.54 micron is of enormous importance for the advancement of new optical communication systems. Erbium (1%) doped fiber amplifiers (EDFA's) or semiconductor lasers are currently being employed as near infrared light sources. Both devices, however, have inherent limitations due to their mode of operation. EDFA's employ an elaborate optical pumping scheme, whereas diode lasers have a strongly temperature dependent lasing wavelength. Novel light emitters based on erbium doped III-V semiconductors could overcome these limitations. Er doped semiconductors combine the convenience of electrical excitation with the excellent luminescence properties of Er(3+) ions. Electrically pumped, compact, and temperature stable optoelectronic devices are envisioned from this new class of luminescent materials. In this paper we discuss the potential of Er doped GaN for optoelectronic applications based on temperature dependent photoluminescence excitation studies.

Thaik, Myo; Hommerich, U.; Schwartz, R. N.; Wilson, R. G.; Zavada, J. M.

1998-01-01

273

Discretely tunable and multiwavelength erbium doped fibre lasers with Fabry-Perot etalon  

NASA Astrophysics Data System (ADS)

Modern WDM telecommunication systems require stable and calibrated laser sources. In this paper, we present examples of such lasers based on erbium doped fibres, i.e., discretely tunable and multiwavelength ring lasers. For the first case, tuning is possible due to a tunable Bragg grating overlapping spectrally the third telecommunication window (1550 nm). When a Fabry-Perot etalon is inserted into the cavity, discrete tunable operation with appropriate spacing between operating wavelengths is possible. Different free spectral ranges (FSR) of applied etalons ensured operation at a wavelength spacing 0.4 nm, 0.8 nm or 1.6 nm, respectively. When an acoustooptical Bragg frequency shifter was inserted together with the Fabry-Perot etalon, the stable simultaneous multiwavelength operation covering the erbium doped gain range was achieved.

Stryjak, M.; Budnicki, A.; Lewicki, R.; Kaczmarek, P. R.; Abramski, K. M.

2008-06-01

274

Sensibilisation de l'avalanche du thulium par l'erbium dans LiYF4  

NASA Astrophysics Data System (ADS)

A par* de l'étude expérimentale d'un cristal de LiYF4 : 1,8% Tm et contenant une très faible concentration d'erbium, nous analysons les effets, sur la luminescence bleue (480 nm) du thulium, des transferts d'énergie entre les deux ions Tm^{3+} et Er'". Notre étude, qui est à la fois spectroscopique et cinétique, est basée sur la méthode d'excitation sélective avec un laser accordable émettant dans le rouge (650 nm). Nous montrons ainsi que, malgré quelques effets négatifs, ces transferts qui existent dans les deux sens, peuvent avoir un effet sensibilisateur positif pour l'avalanche de photons, à condition que l'erbium reste faiblement concentré.

Bouffard, M.; Jouait, J. P.; Duvaut, T.

2002-06-01

275

Photo-annealing effect of gamma-irradiated erbium-doped fibre by femtosecond pulsed laser  

NASA Astrophysics Data System (ADS)

In this work, a photo-annealing effect of gamma-irradiated erbium-doped glass fibre is investigated. Two commercial erbium-doped fibres (EDFs) with different doping concentrations were sealed inside a chamber with a cobalt-60 gamma source for 6 h to give an accumulated dose of 3.18 kGy. A tunable femtosecond pulsed laser with a repetition rate of 80 MHz was then used to pump EDF to generate 1550 nm fluorescence and green up-conversion emission, resulting in the annealing effect of the gamma-irradiated EDF. The fluorescence power of gamma-irradiated EDF with a moderate level of doping was almost returned to the initial state by photo-annealing, unlike that of a heavily doped EDF. This finding may facilitate the development of anti-irradiated superfluorescence fibre source for space navigation.

Hsiung Chang, Sheng; Liu, Ren-Young; Lin, Chu-En; Chou, Fong-In; Tai, Chao-Yi; Chen, Chii-Chang

2013-12-01

276

Invariant bandwidth of erbium in ZnO-PbO-tellurite glasses: Local probe/model  

NASA Astrophysics Data System (ADS)

A series of [(70TeO2-(30-x)ZnO-xPbO)0.99-(Er2O3)0.01; where x = 5, 10, 15 and 20] tellurite glasses, were prepared using the melt quenching technique. Crucial emission bandwidth of erbium at 1.5 ?m has been derived and found to be the same for all the glasses, irrespective of PbO content. This identical bandwidth in all tellurite glasses is attributed to the presence of erbium in tellurium rich disordered environments. This result has been complemented through XANES spectra and the obtained invariant first shell of 6.5 oxygen atoms, confirm the unchanged environment in these glasses for all PbO content.

Ramamoorthy, Raj Kumar; Bhatnagar, Anil K.

2014-04-01

277

Mode-locked L-band bismuth-erbium fiber laser using carbon nanotubes  

NASA Astrophysics Data System (ADS)

A passively mode-locked, bismuth-erbium-co-doped fiber (Bi-EDF) with a pulse width of 460 fs is proposed and demonstrated. A highly doped, 180-cm Bi-EDF with an erbium concentration of 3,250 ppm/wt and an absorption rate of 133 dB/m at 1,530 nm serves as the gain medium. The cavity is 11.6 m long with an overall group velocity dispersion of +0.063 ps2. The output pulses have a repetition rate, average output power, pulse energy and peak power of 11.18 MHz, 5 mW, 448 pJ and 1 kW, respectively. The system has a high beam quality and a narrow pulse width output in the L-band region.

Ahmad, H.; Zulkifli, A. Z.; Muhammad, F. D.; Zulkifli, M. Z.; Thambiratnam, K.; Harun, S. W.

2014-06-01

278

[Erbium 169 synoviortheses and infiltrations of triamcinolone hexacetonide in metatarsophalangeal arthritis of chronic inflammatory rheumatism].  

PubMed

The authors report their experience in the treatment of metatarsophalangeal arthritis of chronic inflammatory rheumatism by Erbium 169 synoviortheses (112 joints treated) and by infiltrations of triamcinolone hexacetonide (53 joints treated). The steroid appears to have a marked early superiority as it gives 85% good results compared to 61.6% for Erbium 169 after a period of one to three months. However, its results then deteriorate more rapidly and after 6 months, the proportion of good results is greater with the radioactive treatment (64% compared to 46.7%). The authors consider it reasonable to use triamcinolone hexacetonide as the first line treatment as it is easier to manage and less expensive, reserving the radioactive synoviortheses for later with the prospect of more lasting results. PMID:6603649

Bouvier, M; Bouysset, M; Bonvoisin, B; Diaine, A; Lejeune, E

1983-04-01

279

Erbium-ytterbium-yttrium compounds for light emission at 1.54microm  

NASA Astrophysics Data System (ADS)

Silicon microphotonics? has emerged as the leading technology to overcome the interconnect bottleneck that limits a further increase of computation power following Moore's law. Optical interconnects between different electronic microprocessors in an electronic-photonic integrated circuit (EPIC) can provide a fast, low-loss and highbandwidth alternative to electrical interconnects, which suffer from issues such as resistive heating, RC delays and channel crosstalk at an increasing device density. A crucial device in such an electronic-photonic integrated circuit is a compact, highgain and low power optical amplifier to compensate for signal attenuation due to propagation losses and to recover signal strength after subsequent 3dB splits during fanout of the optical signal to different microprocessors. Erbium ions (Er3+) are an excellent candidate to provide amplification around .. = 1.54pm for optical telecommunications. Erbium-doped fiber amplifiers (EDFAs) have already enabled long-haul optical data. transmission through silica optical fibers, but scaling down a fiber amplifier to an on-chip erbium-doped waveguide amplifier (EDWA) brings along significant materials and device design challenges. In this thesis, erbium-ytterbium oxide (Erx Yb2-xO 3) and erbium-ytterbium-yttrium silicate (ErxYhyY 2-x-ySi2O7) compounds are investigated as novel materials systems for the development of EDWAs. The high erbium and ytterbium solubility (>1022 cm-3) and refractive index (1.71 < n < 1.92) make these materials excellent candidates for compact, low-power optical amplifiers. Erx Yb2-xO 3 and ErxYhyY2-x-ySi2O 7 thin films were deposited on SiO2 and analyzed structurally and optically. The role of ytterbium in these compounds is twofold. First, ytterbium can be used as an alternative to yttrium for dilution of the erbium concentration in order to mitigate parasitic concentration quenching effects. Second, ytterbium acts as a sensitizer for erbium during optical pumping at lambda = 980nm. Comparison of the different oxide and silicate thin films reveals that the alpha-disilicate phase is the best candidate for an EDWA gain medium pumped at lambda = 980nm. By means of rate and propagation equations, the composition of an Er xYhyY2-x-ySi2O7 gain medium was optimized for application as a 3dB EDWA. The optimal composition was found to be Er0.025Yb0.200Yb0.200Y1.775Si 2O7, which provides a 1.5dB/cm gain at only 3mW of pump power. In terms of the figure of merit 3dB gain/(device area ? pump power), this material outperforms other EDWA materials reported in literature. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu)

Vanhoutte, Michiel

280

Advancements in sapphire optical fibers for the delivery of erbium laser energy and IR sensor applications  

NASA Astrophysics Data System (ADS)

Sapphire fibers grown using the Saphikon EFGTM technique have proven to be effective delivery systems for Erbium:YAG and Erbium:YSGG laser energy. Improvements to the growth process have decreased average fiber attenuation to 1.5 dB/meter with 0.2 dB/meter demonstrated. Diameter control has also improved considerably. Current growth capabilities include diameters ranging from 150 microns to 1500 microns, multiple strands grown simultaneously, and increased length of grown fibers. Laser damage threshold levels of 1250 J/cm2 and power handling capacity of over 11 watts have been demonstrated, as have pulse lifetimes of 150,000 pulses at 275 mJ/pulse output energy. Use of sapphire fibers for high power applications such as dentistry along with other, non-medical applications is discussed.

Pryshlak, Adrian P.; Dugan, Jeffrey R.; Fitzgibbon, Jeremiah J.

1996-04-01

281

Healing of bone in the rat following surgery with the erbium-YAG laser  

NASA Astrophysics Data System (ADS)

Background and objectives: the aim of this study was to examine the pattern of healing in rat calvarial defects prepared with the erbium-YAG laser, using the 'guided tissue regeneration' technique. Materials and method: PTFE membranes were placed over lased skull defects, and the skin wounds sutured. Rats were killed humanely at intervals after surgery, and the skulls processed for paraffin wax histology. A further group of mature rats were also killed humanely and the calvariae removed. Slots were prepared using the erbium-YAG laser and immediately examined under the environmental scanning electron microscope (ESEM) in hydrated conditions, which avoided drying artifacts. Results: An amorphous, mineral-rich carbon layer surrounds the lased bone defect, which in the in vivo experiments was seen as a basophilic zone which was resistant to resorption.

Dickinson, Mark R.; Devlin, Hugh; El Montaser, Monsour A.; Sloan, P.

1996-12-01

282

Erbium and terbium photoluminescence in silica sol–gel films on porous alumina  

Microsoft Academic Search

Porous alumina covered with spin-on erbium-doped silica sol–gel film, subjected to thermal processing above 973 K, exhibited strong Er-related photoluminescence at 1.53 ?m at room temperature. The intensity of the photoluminescence increases with the thickness of both the porous alumina and the spin-on film, the latter being built up layer-by-layer to avoid cracking. SIMS analysis shows that the Er penetrates

N. V Gaponenko; V. M Parkun; O. S Katernoga; V. E Borisenko; A. V Mudryi; E. A Stepanova; A. I Rat'ko; M Cavanagh; B O'Kelly; J. F McGilp

1997-01-01

283

Dispersion-managed dark solitons in erbium-doped fiber lasers  

Microsoft Academic Search

We report on the observation of dispersion-managed (DM) dark soliton emission in a net-normal dispersion erbium-doped fiber laser. We found experimentally that dispersion management could not only reduce the pump threshold for the dark soliton formation in a fiber laser, but also stabilize the single dark soliton evolution in the cavity. Numerical simulations have also confirmed the DM dark soliton

Han Zhang; Dingyuan Tang; Mustapha Tlidi; Luming Zhao; Xuan Wu

2010-01-01

284

Mode-locking of thulium-doped and erbium-doped fiber lasers  

Microsoft Academic Search

This thesis reports work on passive mode-locking of thulium-doped and erbium-doped fiber ring lasers using the technique of polarization additive pulse mode-locking (P-APM). A self-starting, mode-locked Tm+3-doped fiber laser was demonstrated with 360 to 500 fsec pulses tunable from 1.8 to 1.9 mum, the largest tuning range demonstrated from a rare-earth doped fiber. This laser operated in the soliton regime

Lynn Elizabeth Nelson

1997-01-01

285

Generation of 47-fs pulses directly from an erbium-doped fiber laser  

Microsoft Academic Search

We show both numerically and experimentally that through appropriately selecting the output coupling position and strength in a mode-locked fiber laser, one can effectively manage the nonlinearity of the cavity. By implementing the technique together with cavity dispersion management in an erbium-doped fiber laser, we have achieved stable mode-locked pulses with a single-pulse energy of 2.08 nJ and pulse width

D. Y. Tang; L. M. Zhao

2007-01-01

286

Tunable Erbium Doped Fiber Laser Using a Silicon Micro-Electro-Mechanical Fabry-Perot Cavity  

Microsoft Academic Search

We propose a novel tunable erbium doped fiber laser using a silicon micro-electro-mechanical (MEM) Fabry-Perot cavity. The cavity is made of two Bragg mirrors, one being actuated by comb drives. The MEM Fabry-Perot cavity and grooves for optical fibers are fabricated by DRIE on a 70 mum SOI wafer and integrated in a ring fiber laser configuration. The fiber laser

J. Masson; S. Bergeron; A. Poulin; N. Godbout; Y.-A. Peter

2007-01-01

287

Aerosol-gel deposition of pyrochlore multicomponent thin films heavily doped with erbium ions  

NASA Astrophysics Data System (ADS)

Optically active films in the system Y2Ti2O7-Er2Ti2O7 have been deposited using the Aerosol-gel process. Photoluminescence properties closely depend on the film crystallization state. Dilution of erbium ions within a crystalline Y2Ti2O7 matrix allows to prevent photoluminescence concentration quenching induced by short range distance interactions. Consequently, heavily doped films with good photoluminescence properties can be obtained.

Langlet, Michel; Jenouvrier, Pierre R.; Fick, Jochen; Rimet, Roger

2003-11-01

288

Tunable Passively -switched Erbium-Doped Fiber Laser With Carbon Nanotubes as a Saturable Absorber  

Microsoft Academic Search

An all-fiber tunable passively Q-switched erbium-doped fiber (EDF) laser is presented. Saturable absorbers are constructed by optically driven deposition of single-wall carbon nanotubes on fiber connectors. A low pump threshold of 11.1 mW is achieved. Self-mode-locking effect is also observed, and it could be suppressed by splicing an extra unpumped EDF into the laser ring cavity. The laser can be

Da-Peng Zhou; Li Wei; Bo Dong; Wing-Ki Liu

2010-01-01

289

X-ray fluorescence spectrometric analysis of erbium oxide for rare earth impurities  

Microsoft Academic Search

An X-ray fluorescence spectrometric method has been developed for the analysis of high purity erbium oxide for the determination of yttrium, terbium, dysprosium, holmium, thulium, ytterbium and lutetium oxide impurities in the concentration range 0.005–0.1%. The sample is taken in oxalate form, mixed with a binder (boric acid) in the weight ratio 31 and made into a double layer pellet.

L. C. Chandola; P. P. Khanna

1985-01-01

290

Pulsed erbium fiber laser with an acetylene-filled photonic crystal fiber for saturable absorption.  

PubMed

We investigate the dynamics of an erbium-doped fiber ring laser that is equipped with an intracavity hollow core photonic crystal fiber gas cell. The cell is filled with acetylene as a saturable absorber. We observe cw operation at low pressures, Q switching at intermediate pressure levels, and mode locking at high pressures applied. Moreover, we show that the transition from the cw to the pulsed mode may be exploited for sensitive gas detection. PMID:21931393

Marty, Patrick Thomas; Morel, Jacques; Feurer, Thomas

2011-09-15

291

Room-temperature 1.5 µm luminescence of co-deposited erbium and germanium  

Microsoft Academic Search

Nanocrystalline germanium films containing erbium were deposited by thermal evaporation under 0.6 Torr of argon onto crystalline silicon wafer substrates. Weak broad photoluminescence (PL) around 1.5 ?m was observed at room temperature. Annealing under 10?7 Torr of vacuum for 3 h at 500 °C produced no change in the PL spectrum. After 1 h oxidation in air at 500 °C

J. H. Chen; D. Pang; H. M. Cheong; P. Wickboldt; W. Paul

1995-01-01

292

Pulpal thermal responses to an erbium,chromium:YSGG pulsed laser hydrokinetic system  

Microsoft Academic Search

Problem. Laser systems are known to raise pulpal temperatures when applied to tooth surfaces. Dental biocalcified tissues can be cut with an erbium,chromium:yttrium-scandium-gallium-garnet laser-powered hydrokinetic system. This device is effective for caries removal and cavity preparation in vitro. Pulpal monitoring of temperature changes during hard tissue cutting by a hydrokinetic system have not been reported.Objectives. This study compared the effects

Ioana Rizoiu; Farideh Kohanghadosh; Andrew I Kimmel; Lewis R Eversole

1998-01-01

293

Self-similar erbium-doped fiber laser with large normal dispersion.  

PubMed

We report a large normal dispersion erbium-doped fiber laser with self-similar pulse evolution in the gain fiber. The cavity is stabilized by the local nonlinear attractor in the gain fiber through the use of a narrow filter. Experimental results are accounted for by numerical simulations. This laser produces 3.5 nJ pulses, which can be dechirped to 70 fs with an external grating pair. PMID:24562267

Liu, Hui; Liu, Zhanwei; Lamb, Erin S; Wise, Frank

2014-02-15

294

Shear bond strength of composite bonded to erbium:yttrium-aluminum-garnet laser-prepared dentin  

Microsoft Academic Search

The purpose of this study was to evaluate the dentin bond strength to resin composite following erbium:yttrium-aluminum-garnet\\u000a (Er:YAG) laser preparation using different adhesive systems. Seventy dentin specimens prepared from human molar teeth were\\u000a randomly assigned to seven groups of ten. The first five groups were prepared with an Er:YAG laser 2940 nm at the manufacturer’s\\u000a recommended settings and (1) acid etched,

Sevil Gurgan; Arlin Kiremitci; Filiz Yalcin Cakir; Esra Yazici; Jale Gorucu; Norbert Gutknecht

2009-01-01

295

Erbium-doped ion-exchanged waveguide lasers in BK7 glass  

Microsoft Academic Search

Ion-exchange in glass is a simple, flexible technique to realize optical fiber-compatible planar waveguide devices. Recently, neodymium-doped waveguide lasers operating at 1060 and 1300 nm have been demonstrated in this technology. Lasers operating at 1540 nm are desirable for telecommunication applications and the authors report for the first time ion-exchanged waveguide lasers in erbium-doped glass emitting at this wavelength. Lasers

T. Feuchter; E. K. Mwarania; J. Wang; L. Reekie; J. S. Wilkinson

1992-01-01

296

Soliton propagation in an erbium-doped fiber with and without a continuous wave background  

NASA Astrophysics Data System (ADS)

Considering ultrashort pulse propagation in a nonlinear resonant fiber governed by Hirota-Maxwell Bloch equations, the soliton interaction in an erbium-doped fiber system associated with higher-order dispersion, self-steepening, and self-induced transparency effects is studied for the case when the fiber is driven with and without a constant pumping source. Using auto-Bäcklund-transformation, one- and two-soliton solutions are generated. The significance of the results is discussed in detail.

Ganapathy, R.; Kuriakose, V. C.; Porsezian, K.

2003-12-01

297

Bidirectional transmission at 622 Mb\\/s utilizing erbium-doped fiber amplifiers  

Microsoft Academic Search

Amplification of two bidirectional 622-Mb\\/s optical signals was demonstrated using a single erbium-doped fiber amplifier (EDFA). Bidirectional amplification was examined with the EDFA operating as a midspan repeater and as a pre\\/post amplifier at one terminal end of a 95-km fiber span. Without using any isolators in the EDFA, bidirectional optical amplification through a single EDFA was achieved while simultaneously

J. Haugen; J. Freeman; J. Conradi

1992-01-01

298

Propagation of signal and noise in concatenated erbium-doped fiber optical amplifiers  

Microsoft Academic Search

Signal propagation and noise accumulation in lightwave systems using saturated optical amplifiers as repeaters are analyzed. Numerical simulations of amplified spontaneous emission in concatenated erbium-doped fiber amplifiers indicate that a reach beyond 10000 km is possible with a 1.55-?m system in the absence of fiber nonlinearities. Distributed optical amplifiers are shown to have low noise, but require higher pump power

C. R. Giles; Emmanuel Desurvire

1991-01-01

299

Theoretical modeling of erbium-doped fiber amplifiers with excited-state absorption  

Microsoft Academic Search

Numerical solution of a general rate-equation model of an erbium-doped fiber amplifier highlights several important features of the device. A difference in strong-signal gain between copropagating and counterpropagating signal pump schemes in the presence of pump excited-state absorption is predicted, and this is confirmed by experiment. The detriment in the noise figure previously associated with counterpropagating schemes for only small-signal

P. R. Morkel; Richard I. Laming

1989-01-01

300

24-line multiwavelength operation of erbium-doped fiber-ring laser  

Microsoft Academic Search

Simultaneous lasing at up to 24 wavelengths is demonstrated in an erbium-doped fiber-ring laser using a simple design. This result is achieved using a low-loss cavity, controlled polarization evolution and liquid nitrogen cooling to enhance spectral hole-burning, polarization hole-burning, and polarization selectivity. The design does not include any wavelength-selective components; instead, it utilizes wavelength selectivity provided by polarization evolution in

Paul F. Wysocki

1996-01-01

301

Evaluation of an erbium modulator in x-ray scatter correction using primary modulation  

NASA Astrophysics Data System (ADS)

A primary modulator made of erbium is evaluated in X-ray scatter correction using primary modulation. Our early studies have shown that erbium is the optimal modulator material for an X-ray cone-beam computed tomography (CBCT) system operated at 120 kVp, exhibiting minimum beam hardening which otherwise weakens the modulator's ability to separate scatter from primary. In this work, the accuracy of scatter correction is compared for two copper modulators (105 and 210 ?m of thickness) and one erbium modulator (25.4 ?m of thickness) with the same modulation frequencies. The variations in the effective transmission factors of these three modulators as functions of object filtrations are first measured to show the magnitudes of beam hardening caused by the modulators themselves. Their scatter correction performances are then tested using a Catphan©600 phantom on our tabletop CBCT system. With and without 300 ?m of copper in the beam, the measured variations for these three modulators are 4.3%, 7.8%, and 0.9%, respectively. Using the 105- and 210-?m copper modulators, our scatter correction method reduces the average CT number error from 327.3 Hounsfield units (HU) to 19.4 and 20.9 HU in the selected regions of interest, and enhances the contrast-to-noise ratio (CNR) from 10.7 to 16.5 and 15.9, respectively. With the 25.4-?m erbium modulator, the CT number error is markedly reduced to 2.8 HU and the CNR is further increased to 17.4.

Gao, Hewei; Niu, Tianye; Zhu, Lei; Fahrig, Rebecca

2011-03-01

302

Erbium-doped optical fiber amplifiers pumped in the 660- and 820-nm bands  

Microsoft Academic Search

State-of-the-art erbium (Er)-doped optical fiber amplifiers (EDFA's) pumped in the 660- and 820-nm bands are described. We have demonstrated highly efficient EDFA's incorporating optimized 664- and 827-nm pump wavelengths and an Er-doped high numerical aperture (NA) fiber with thermally diffused expanded core (TEC) fiber ends. Gain coefficients of 3.8 and 1.3 dB\\/mW at respective wavelengths of 664 and 827 nm

Masaharu Horiguchi; Kaoru Yoshino; Makoto Shimizu; Makoto Yamada; Hiroaki Hanafusa

1994-01-01

303

Influence of pulse duration on erbium and holmium laser ablation under water  

Microsoft Academic Search

Erbium and Holmium lasers are ideally suited for cutting and drilling biological tissue. This is due to the fact that their wavelengths (Er:YSGG at 2.79 micrometers and Ho:YAG at 2.12 micrometers ) are strongly absorbed in water which is present in all tissues. Combined with an optical fiber these lasers seem to be optimal instruments for endoscopic and\\/or minimal invasive

Michael Ith; Martin Frenz; Hans Pratisto; Heinz P. Weber; Hans J. Altermatt; Hans U. Staeubli; Thomas Asshauer; Guy P. Delacretaz; Rene-Paul Salathe; Bruno E. Gerber

1995-01-01

304

Self-similar erbium-doped fiber laser with large normal dispersion  

PubMed Central

We report a large normal dispersion erbium-doped fiber laser with self-similar pulse evolution in the gain fiber. The cavity is stabilized by the local nonlinear attractor in the gain fiber through the use of a narrow filter. Experimental results are accounted for by numerical simulations. This laser produces 3.5 nJ pulses, which can be dechirped to 70 fs with an external grating pair.

Liu, Hui; Liu, Zhanwei; Lamb, Erin S.; Wise, Frank

2014-01-01

305

Actively mode-locked tunable dual-wavelength erbium-doped fiber laser  

Microsoft Academic Search

We report an actively mode-locked tunable dual-wavelength erbium-doped fiber laser that uses parallel amplifiers in order to minimize gain cross-saturation effects. We obtain extremely stable, room-temperature dual-wavelength operation at a modulator drive frequency of 1035.38 MHz (corresponding pulsewidths of 115 and 130 ps). Furthermore, we can independently tune the power and wavelength of each lasing output signal without affecting overall

Dominik Pudo; Lawrence R. Chen; Domenico Giannone; Lin Zhang; Ian Bennion

2002-01-01

306

Modulation-frequency-controlled change from sub- to superluminal regime in highly doped erbium fibers.  

PubMed

We report a change from sub- to superluminal propagation upon increasing the modulation frequency of an amplitude-modulated 1,550 nm signal when propagating through highly doped erbium fibers pumped at 980 nm. We show that the interplay between the pump absorption and the pump-power broadening of the spectral hole induced by coherent population oscillations may drastically affect the fractional advancement or delay of the signal for the considered fibers. PMID:18414546

Melle, Sonia; Calderón, Oscar G; Caro, Cesar E; Cabrera-Granado, E; Antón, M A; Carreño, F

2008-04-15

307

Soliton propagation in an erbium-doped fiber with and without a continuous wave background.  

PubMed

Considering ultrashort pulse propagation in a nonlinear resonant fiber governed by Hirota-Maxwell Bloch equations, the soliton interaction in an erbium-doped fiber system associated with higher-order dispersion, self-steepening, and self-induced transparency effects is studied for the case when the fiber is driven with and without a constant pumping source. Using auto-Bäcklund-transformation, one- and two-soliton solutions are generated. The significance of the results is discussed in detail. PMID:14754344

Ganapathy, R; Kuriakose, V C; Porsezian, K

2003-12-01

308

The route toward a diode-pumped 1-W erbium 3-µm fiber laser  

Microsoft Academic Search

A rate-equation analysis of the erbium 3-um ZBLAN fiber laser is performed. The computer calculation includes the longitudinal spatial resolution of the host material. It considers ground-state bleaching, excited-state absorption (ESA), interionic processes, lifetime quenching by co-doping, and stimulated emission at 2.7 um and 850 nm. State-of-the-art technology including double-clad diode pumping is assumed in the calculation. Pump ESA is

Markus Pollnau

1997-01-01

309

The route toward a diode-pumped 1-W erbium 3-?m fiber laser  

Microsoft Academic Search

A rate-equation analysis of the erbium 3-?m ZBLAN fiber laser is performed. The computer calculation includes the longitudinal spatial resolution of the host material. It considers ground-state bleaching, excited-state absorption (ESA), interionic processes, lifetime quenching by co-doping, and stimulated emission at 2.7 ?m and 850 mn. State-of-the-art technology including double-clad diode pumping is assumed in the calculation. Pump ESA is

M. Pollnan

1997-01-01

310

Near-IR imaging of Erbium Laser Ablation with a Water Spray  

PubMed Central

Near-IR (NIR) imaging can be used to view the formation of ablation craters during laser ablation since the enamel of the tooth is almost completely transparent near 1310-nm1. Laser ablation craters can be monitored under varying irradiation conditions to assess peripheral thermal and transient-stress induced damage, measure the rate and efficiency of ablation and provide insight into the ablation mechanism. There are fundamental differences in the mechanism of enamel ablation using erbium lasers versus carbon dioxide laser systems due to the nature of the primary absorber and it is necessary to have water present on the tooth surface for efficient ablation at erbium laser wavelengths. In this study, sound human tooth sections of approximately 2-3-mm thickness were irradiated by free running and Q-switched Er:YAG & Er:YSGG lasers under varying conditions with and without a water spray. The incision area in the interior of each sample was imaged using a tungsten–halogen lamp with a band-pass filter centered at 1310-nm combined with an InGaAs area camera with a NIR zoom microscope. Obvious differences in the crater evolution were observed between CO2 and erbium lasers. Ablation stalled after a few laser pulses without a water spray as anticipated. Efficient ablation was re-initiated by resuming the water spray. Micro-fractures were continuously produced apparently driven along prism lines during multi-pulse ablation. These fractures or fissures appeared to merge together as the crater evolved to form the leading edge of the ablation crater. These observations support the proposed thermo-mechanical mechanisms of erbium laser involving the strong mechanical forces generated by selective absorption by water.

Darling, Cynthia L.; Maffei, Marie E.; Fried, William A.; Fried, Daniel

2011-01-01

311

Subpicosecond pulse propagation in an erbium-doped fiber amplifier with ion-induced dispersion  

Microsoft Academic Search

An analysis technique for sub-picosecond pulse propagation in an erbium-doped fiber amplifier (EDFA) was proposed that could be applied to the entire bandwidth range of the device. The model was developed directly from measured absorption and emission cross-section data, and included pump depletion and amplified spontaneous emission. Linear and nonlinear pulse propagation were studied parametrically. An expression was derived for

Mark Brandon Hoffman

1997-01-01

312

Frequency comb expansion based on optical feedback, highly nonlinear and erbium-doped fibers  

NASA Astrophysics Data System (ADS)

This works presents an efficient technique for generating multi-wavelength sources, which consist of an expanded optical frequency comb based on the nonlinear process of multiple four-wave mixing. The nonlinear efficiency is significantly enhanced by the use of the proposed scheme based on optical feedback, highly nonlinear and erbium-doped fibers. Numerical and experimental results illustrate its efficiency and applicability by expanding a comb from 20 to over 200 coherent lines spaced by only 12.5 GHz.

Melo, S. A. S.; do Nascimento, A. R.; Cerqueira S., Arismar; Carvalho, L. H. H.; Pataca, D. M.; Oliveira, J. C. R. F.; Fragnito, H. L.

2014-02-01

313

Near-IR imaging of Erbium Laser Ablation with a Water Spray.  

PubMed

Near-IR (NIR) imaging can be used to view the formation of ablation craters during laser ablation since the enamel of the tooth is almost completely transparent near 1310-nm(1). Laser ablation craters can be monitored under varying irradiation conditions to assess peripheral thermal and transient-stress induced damage, measure the rate and efficiency of ablation and provide insight into the ablation mechanism. There are fundamental differences in the mechanism of enamel ablation using erbium lasers versus carbon dioxide laser systems due to the nature of the primary absorber and it is necessary to have water present on the tooth surface for efficient ablation at erbium laser wavelengths. In this study, sound human tooth sections of approximately 2-3-mm thickness were irradiated by free running and Q-switched Er:YAG & Er:YSGG lasers under varying conditions with and without a water spray. The incision area in the interior of each sample was imaged using a tungsten-halogen lamp with a band-pass filter centered at 1310-nm combined with an InGaAs area camera with a NIR zoom microscope. Obvious differences in the crater evolution were observed between CO(2) and erbium lasers. Ablation stalled after a few laser pulses without a water spray as anticipated. Efficient ablation was re-initiated by resuming the water spray. Micro-fractures were continuously produced apparently driven along prism lines during multi-pulse ablation. These fractures or fissures appeared to merge together as the crater evolved to form the leading edge of the ablation crater. These observations support the proposed thermo-mechanical mechanisms of erbium laser involving the strong mechanical forces generated by selective absorption by water. PMID:21892255

Darling, Cynthia L; Maffei, Marie E; Fried, William A; Fried, Daniel

2008-01-20

314

ERBIUM-DOPED UP-CONVERTERS ON SILICON SOLAR CELLS: ASSESSMENT OF THE POTENTIAL  

Microsoft Academic Search

Erbium-doped up-converters are expected to lead to an increase in efficiency of silicon solar cells by utilising the low energy region of the solar spectrum. This paper focuses on two host-materials, YF3 and BaCl2 both doped with Er3+ and therefore absorbing at about 1.5µm and BaCl2 co-doped with Er 3+ and Dy3+, and therefore absorbing at about 1.3µm. The number

C. Strümpel; M. McCann; C. del Cañizo; I. Tobias; P. Fath

315

Evaluation of mineral content of dentin prepared by erbium, chromium:yttrium scandium gallium garnet laser  

Microsoft Academic Search

Laser etching has an effect on the mineral content of dentin. The aim of this study was to evaluate the mineral content of\\u000a dentin prepared at three different power settings with an erbium, chromium:yttrium scandium gallium garnet (Er,Cr:YSGG) laser.\\u000a The enamel of five, lower, wisdom, molar teeth was removed to expose the dentin surface. Four dentin slabs were obtained,\\u000a then

Asli Secilmis; Subutayhan Altintas; Aslihan Usumez; Gizem Berk

2008-01-01

316

Gain Control in L-Band Erbium-Doped Fiber Amplifier Using a Ring Resonator  

Microsoft Academic Search

Gain control in a long-wavelength (L-band) erbium-doped fiber amplifier (EDFA) using a counter-propagating ring resonator is demonstrated. The clamped gain can be controlled to be in the range from 7.0 to 18.0 dB for the 1580 nm signal at -30 dBm by tuning the oscillating laser in the range from 1565 to 1540 nm. The design prevents oscillating light from

Sulaiman Wadi Harun; Nizam Tamchek; Prabakaran Poopalan; Harith Ahmad

2002-01-01

317

Effect of erbium addition on the corrosion behaviour of Mg–Al alloys  

Microsoft Academic Search

The corrosion behaviour of two Mg–Al–Er alloys with increasing content of erbium (Mg95Al3Er2 and Mg95Al2Er3) has been evaluated in borate buffer solution and compared with that of the commercial AM60 alloy (Mg–6.0Al–0.13Mn, at%) employed in the automotive industry. Scanning electron microscopy and quantitative electron probe microanalysis were used to characterize the samples, prior and after the electrochemical tests. The experiments

F. Rosalbino; E. Angelini; S. De Negri; A. Saccone; S. Delfino

2005-01-01

318

Synthesis, characterization and properties of erbium-based nanofibres and nanorods  

Microsoft Academic Search

Low-dimensional nanostructures (nanofibres, nanorods and nanolayers) can be selectively synthesized from erbium oxide hydroxide ErOOH using a facile hydrothermal method. The ErOOH nanofibres are monoclinic with diameters in the range of 6–30 nm. Some of the nanofibres grow into branches of the same size. This nanomaterial was obtained in subcritical water in a batch reactor at pH 12, temperature 300

H Assaaoudi; Z Fang; J E Barralet; A J Wright; I S Butler; J A Kozinski

2007-01-01

319

Synthesis, characterization and properties of erbium-based nanofibres and nanorods  

Microsoft Academic Search

Low-dimensional nanostructures (nanofibres, nanorods and nanolayers) can be selectively synthesized from erbium oxide hydroxide ErOOH using a facile hydrothermal method. The ErOOH nanofibres are monoclinic with diameters in the range of 6-30 nm. Some of the nanofibres grow into branches of the same size. This nanomaterial was obtained in subcritical water in a batch reactor at pH 12, temperature 300

H. Assaaoudi; Z. Fang; J. E. Barralet; A. J. Wright; I. S. Butler; J. A. Kozinski

2007-01-01

320

Synthesis And Luminescence Properties of Erbium-Doped Y(2)O(3) Nanotubes  

Microsoft Academic Search

Erbium-doped yttrium oxide nanotubes (Er{sup 3+}:YO NTs) with 0-100% doping levels were synthesized by a hydrothermal procedure followed by a dehydration process from Er{sup 3+}:Y(OH) NTs. The as-synthesized Er{sup 3+}:YO nanotubes ranged from 100 to 400 nm in outer diameter and 2 to 5 m in length with a hexagonal cross section. A time-dependent nanostructure evolution study was performed under

Y. Mao; J. Y. Huang; R. Ostroumov; K. L. Wang; J. P. Chang

2009-01-01

321

Lanthanide Recognition: an Asymetric Erbium Microsensor Based on a Hydrazone Derivative  

PubMed Central

N'-(2-hydroxy-1,2-diphenylethylidene)benzohydrazide (HDB) was found to have a very selective and sensitive behavior towards erbium(III) ions, in comparison to thirteen lanthanide ions, inner transition and representative metal ions and was hence used as a neutral ion carrier in construction of an Er(III) microelectrode. Theoretical calculations and conductance studies of HDB to erbium and some other metal ions were carried out and confirmed selectivity toward Er(III) ions. The best performance was obtained with a membrane contain 3% potassium tetrakis(p-chlorophenyl)borate (KTpClPB) as an anionic additive, 72% dibutyl phthalate (DBP) as solvent mediator, 5% HDB, and 20% poly(vinyl chloride) (PVC). The proposed Er(III) microelectrode exhibits a near Nernstian response of 17.5±0.5 mV per decade of erbium activity, and a very wide linear range 1.0×10-3-3.0×10-10 M. It can work well in the pH range of 3.0-9.0. The lower detection limit (LDL) of the microelectrode was calculated to be 2.0×10-10 M.

Faridbod, Farnoush; Ganjali, Mohammad Reza; Larijani, Bagher; Norouzi, Parviz; Riahi, Siavash; Mirnaghi, Fatemeh Sadat

2007-01-01

322

Core-shell nanoparticle erbium-doped fibers for next generation amplifiers  

NASA Astrophysics Data System (ADS)

New generation systems are expected to include more intelligent amplifiers able to adapt to many conditions including different gains, channel load, temperature, aging and transient events.1 To face the challenge and meet these new requirements, having an accurate control on the Er environment within the fiber core matrix has never appeared to be so necessary and predominant as it is the case now. Unlike conventional solution doping techniques where Erbium ions are randomly incorporated in the fiber core, our process makes use of a soft chemical synthesis to initially produce Erbium-doped nanoparticles (NPs). Erbium ions are therefore incorporated in the fiber core together with their local environment. So far, our investigations2 first showed that, from the material point of view, quenching levels are intimately linked to the design of the NPs through their chemical composition. Then, from the system perspective, we evidenced the higher power conversion efficiencies exhibited by NP fibers when compared to their conventional counterparts in high power amplifier configurations. In this paper, we address our most recent work focusing on the NP optimisation towards quenching-free Erbiumdoped fibers with a particular focus on core-shell alumino-silicate NPs. Completing our first amplifier results obtained in high power configurations, we also explore new NP fiber profiles that extend the range of their applications. Gain and noise characteristics of typical WDM operating points serve as key indicators on the benefits our NP doping process could provide.

Boivin, David; Pastouret, Alain; Burov, Ekaterina; Gonnet, Cédric; Cavani, Olivier; Lempereur, Simon; Sillard, Pierre; Goldmann, Claire; Saudry, Elodie; Chanéac, Corinne; Shlifer, Alex; Ghera, Uri

2012-02-01

323

Stable zirconia-erbium doped multiwavelength fiber laser by precise control of polarization states  

NASA Astrophysics Data System (ADS)

A compact zirconium-erbium doped fiber (Zr-EDF) based multiwavelength fiber laser (MWFL) with stable output comb is proposed and demonstrated. The MWFL utilizes a 3 m long Zr-EDF with an erbium concentration of 3000 ppm and pumped by a 1480 nm laser diode (LD) as the active gain medium. A fiber based multimode polarization controller (PC) is used to precisely control the polarization states of the oscillating modes in the MWFL, distributing the total energy of the system among the lasing wavelengths in order to overcome the mode-suppression and mode-competition that arises from homogenous line broadening. The MWFL is capable of generating up to four lasing wavelengths with average peak powers of 0.08 dBm in the extended L-band of 1600 nm. The lasing wavelengths have a 3-dB linewidth of 0.1 and an extinction ratio of 40 dB as well as highly stable, with minimal fluctuations of less than 0.6 dB observed in the peak powers of the lasing wavelengths over a period of 1 h. The proposed system allows for the realization of a compact, cost-effective and stable erbium based MWFL capable of operating at room temperature.

Ahmad, H.; Thambiratnam, K.; Awang, N. A.; Jemangin, M. H.; Harun, S. W.

2012-05-01

324

Theoretical study of cascade laser in erbium-doped chalcogenide glass fibers  

NASA Astrophysics Data System (ADS)

A theoretical investigation of an innovative cascade laser source is performed. The main goal of the work is the design of a continuous-wave (CW) photonic crystal fiber (PCF) laser, based on an erbium-doped chalcogenide glass. Due to the comparable lifetimes of the 4I 13/2, 4I 11/2 and 4I 9/2 erbium energy levels, the simultaneous emissions at the wavelengths close to 2.7 ?m and 4.5 ?m are obtained with a pump wavelength close to 806 nm (direct pumping into the level 4I 9/2). This scheme could be useful to develop high efficiency, high beam-quality and compact Near-IR and Mid-IR oscillators with single-mode output for applications not only in surgery but also in spectroscopy, remote sensing, infrared countermeasures. The feasibility investigation is performed by taking into account the optical and spectroscopic parameters measured on a previously fabricated chalcogenide glass sample. A home made numerical code that solves the multilevel rate equations and the power propagation equations has been ad hoc developed. The obtained results constitute a realistic feasibility investigation of the Mid-IR laser performance by varying the length and the transversal cross section of the fiber, the mirrors reflectivity, the erbium concentration.

Prudenzano, Francesco; Mescia, Luciano; Allegretti, Luca; Moizan, Virginie; Nazabal, Virginie; Smektala, Frédéric

2010-12-01

325

microRNA-152 Mediates DNMT1-Regulated DNA Methylation in the Estrogen Receptor ? Gene  

PubMed Central

Background Estrogen receptor ? (ER?) has been shown to protect against atherosclerosis. Methylation of the ER? gene can reduce ER? expression leading to a higher risk for cardiovascular disease. Recently, microRNAs have been found to regulate DNA methyltransferases (DNMTs) and thus control methylation status in several genes. We first searched for microRNAs involved in DNMT-associated DNA methylation in the ER? gene. We also tested whether statin and a traditional Chinese medicine (San-Huang-Xie-Xin-Tang, SHXXT) could exert a therapeutic effect on microRNA, DNMT and ER? methylation. Methodology/Principal Findings The ER? expression was decreased and ER? methylation was increased in LPS-treated human aortic smooth muscle cells (HASMCs) and the aorta from rats under a high-fat diet. microRNA-152 was found to be down regulated in the LPS-treated HASMCs. We validated that microRNA-152 can knock down DNMT1 in HASMCs leading to hypermethylation of the ER? gene. Statin had no effect on microRNA-152, DNMT1 or ER? expression. On the contrary, SHXXT could restore microRNA-152, decrease DNMT1 and increase ER? expression in both cellular and animal studies. Conclusions/Significance The present study showed that microRNA-152 decreases under the pro-atherosclerotic conditions. The reduced microRNA-152 can lose an inhibitory effect on DNA methyltransferase, which leads to hypermethylation of the ER? gene and a decrease of ER? level. Although statin can not reverse these cascade proatherosclerotic changes, the SHXXT shows a promising effect to inhibit this unwanted signaling pathway.

Wang, Yung-Song; Chou, Wen-Wen; Chen, Ku-Chung; Cheng, Hsin-Yun; Lin, Ruey-Tay; Juo, Suh-Hang Hank

2012-01-01

326

Mutations in Centrosomal Protein CEP152 in Primary Microcephaly Families Linked to MCPH4  

PubMed Central

Primary microcephaly is a rare condition in which brain size is substantially diminished without other syndromic abnormalities. Seven autosomal loci have been genetically mapped, and the underlying causal genes have been identified for MCPH1, MCPH3, MCPH5, MCPH6, and MCPH7 but not for MCPH2 or MCPH4. The known genes play roles in mitosis and cell division. We ascertained three families from an Eastern Canadian subpopulation, each with one microcephalic child. Homozygosity analysis in two families using genome-wide dense SNP genotyping supported linkage to the published MCPH4 locus on chromosome 15q21.1. Sequencing of coding exons of candidate genes in the interval identified a nonconservative amino acid change in a highly conserved residue of the centrosomal protein CEP152. The affected children in these two families were both homozygous for this missense variant. The third affected child was compound heterozygous for the missense mutation plus a second, premature-termination mutation truncating a third of the protein and preventing its localization to centrosomes in transfected cells. CEP152 is the putative mammalian ortholog of Drosphila asterless, mutations in which affect mitosis in the fly. Published data from zebrafish are also consistent with a role of CEP152 in centrosome function. By RT-PCR, CEP152 is expressed in the embryonic mouse brain, similar to other MCPH genes. Like some other MCPH genes, CEP152 shows signatures of positive selection in the human lineage. CEP152 is a strong candidate for the causal gene underlying MCPH4 and may be an important gene in the evolution of human brain size.

Guernsey, Duane L.; Jiang, Haiyan; Hussin, Julie; Arnold, Marc; Bouyakdan, Khalil; Perry, Scott; Babineau-Sturk, Tina; Beis, Jill; Dumas, Nadine; Evans, Susan C.; Ferguson, Meghan; Matsuoka, Makoto; Macgillivray, Christine; Nightingale, Mathew; Patry, Lysanne; Rideout, Andrea L.; Thomas, Aidan; Orr, Andrew; Hoffmann, Ingrid; Michaud, Jacques L.; Awadalla, Philip; Meek, David C.; Ludman, Mark; Samuels, Mark E.

2010-01-01

327

Isomeric yield ratios in nuclei 190Ir and 150,152Eu  

Microsoft Academic Search

Isomeric yield ratios Ir190m2,m1+g, Eu150m,g, Eu152m1,m2 have been measured in (gamma,n)-reactions for the end point energies of bremmsstrahlung photons about 12, 12.5, and 16 MeV for Ir190m2,m1+g and 12 MeV for Eu150m,g, Eu152m1,m2. Experimental values of the isomeric yield ratios have been compared with the theoretical values, which were calculated by using codes TALYS and MCEM. The low influence of

I. N. Vishnevsky; V. A. Zheltonozhsky; A. N. Savrasov; N. V. Strilchuk

2009-01-01

328

Isomeric yield ratios in nuclei 190Ir and 150,152Eu  

NASA Astrophysics Data System (ADS)

Isomeric yield ratios Ir190m2,m1+g, Eu150m,g, Eu152m1,m2 have been measured in (?,n)-reactions for the end point energies of bremmsstrahlung photons about 12, 12.5, and 16 MeV for Ir190m2,m1+g and 12 MeV for Eu150m,g, Eu152m1,m2. Experimental values of the isomeric yield ratios have been compared with the theoretical values, which were calculated by using codes TALYS and MCEM. The low influence of nonstatistical effects has been observed for all these energies.

Vishnevsky, I. N.; Zheltonozhsky, V. A.; Savrasov, A. N.; Strilchuk, N. V.

2009-01-01

329

Performance Validation of Version 152.0 ANSER Control Laws for the F-18 HARV  

NASA Technical Reports Server (NTRS)

The Actuated Nose Strakes for Enhanced Rolling (ANSER) Control Laws were modified as a result of Phase 3 F/A-18 High Alpha Research Vehicle (HARV) flight testing. The control law modifications for the next software release were designated version 152.0. The Ada implementation was tested in the Hardware-In-the-Loop (HIL) simulation and results were compared to those obtained with the NASA Langley batch Fortran implementation of the control laws which are considered the 'truth model.' This report documents the performance validation test results between these implementations for ANSER control law version 152.0.

Messina, Michael D.

1996-01-01

330

Study of the absorption spectra of 4 f electron transitions of the neodymium and erbium complexes with diphacinone and Triton X-100 and its analytical application  

NASA Astrophysics Data System (ADS)

The absorption spectra of 4 f electron transitions of the neodymium and erbium complexes with 2-(diphenylacetyl)indan-1,3-dione and octylphenol poly(ethyleneglycol)ether have been studied by normal and derivative spectrophotometry. Use of third-derivative spectra can eliminate the interference from other rare earth elements and enhance the sensitivity for neodymium and erbium. Beer's law is obeyed for 0-35 ?g cm -3 of neodymium and 0-50 ?g cm -3 of erbium. Their molar absorptivity at the maximum absorption bands are about 7.4 times for neodymium and 11.4 times for erbium greater than that for the equivalent amount of neodymium and erbium in the chlorides. The relative standard deviations evaluated from seven independent determinations of 8.3 ?g cm -3 of neodymium and 8.5 ?g cm -3 of erbium are 1.4 and 1.5%, respectively. The detection limits (signal to noise ratio = 2) are 0.06 ?g cm -3 for neodymium and 0.1 ?g cm -3 for erbium. A method for the direct determination of neodymium and erbium in mixtures of rare earth elements with good accuracy and selectivity, is described.

Yang, Jinghe; Wang, Naixing; Wang, Yingjie; Liang, Weian; Ge, Hongmei; Zhou, Jie

1995-02-01

331

Speciation of artificial radionuclides 60 Co, 137 Cs, 152 Eu, and 241 Am in bottom sediments of the Yenisei river  

Microsoft Academic Search

The speciation of artificial radionuclides 60Co, 137Cs, 152Eu, and 241Am in surface layers of bottom sediments of the Yenisei river, collected within the near zone of impact of the Mining and\\u000a Chemical Combine (Rosatom), was studied. In these samples the radionuclides 60Co, 152Eu, and 241Am are mainly associated with fractions of humic and fulvic acids. The fraction of 152Eu associated

L. G. Bondareva; A. Ya. Bolsunovskii

2008-01-01

332

Optimizing the pumping configuration for the power scaling of in-band pumped erbium doped fiber amplifiers.  

PubMed

A highly efficient (~80%), high power (18.45 W) in-band, core pumped erbium/ytterbium co-doped fiber laser is demonstrated. To the best of our knowledge, this is the highest reported efficiency from an in-band pumped 1.5 µm fiber laser operating in the tens of watts regime. Using a fitted simulation model, we show that the significantly sub-quantum limit conversion efficiency of in-band pumped erbium doped fiber amplifiers observed experimentally can be explained by concentration quenching. We then numerically study and experimentally validate the optimum pumping configuration for power scaling of in-band, cladding pumped erbium doped fiber amplifiers. Our simulation results indicate that a ~77% power conversion efficiency with high output power should be possible through cladding pumping of current commercially available pure Erbium doped active fibers providing the loss experienced by the cladding guided 1535 nm pump due to the coating absorption can be reduced to an acceptable level by better coating material choice. The power conversion efficiency has the potential to exceed 90% if concentration quenching of erbium ions can be reduced via improvements in fiber design and fabrication. PMID:22714454

Lim, Ee-Leong; Alam, Shaif-ul; Richardson, David J

2012-06-18

333

Surface segregation effects of erbium in GaAs growth and their implications for optical devices containing ErAs nanostructures  

SciTech Connect

We report on the integration of semimetallic ErAs nanoparticles with high optical quality GaAs-based semiconductors, grown by molecular beam epitaxy. Secondary ion mass spectrometry and photoluminescence measurements provide evidence of surface segregation and incorporation of erbium into layers grown with the erbium cell hot, despite the closed erbium source shutter. We establish the existence of a critical areal density of the surface erbium layer, below which the formation of ErAs precipitates is suppressed. Based upon these findings, we demonstrate a method for overgrowing ErAs nanoparticles with III-V layers of high optical quality, using subsurface ErAs nanoparticles as a sink to deplete the surface erbium concentration. This approach provides a path toward realizing optical devices based on plasmonic effects in an epitaxially-compatible semimetal/semiconductor system.

Crook, Adam M.; Nair, Hari P.; Bank, Seth R. [University of Texas at Austin, Microelectronics Research Center, 10100 Burnet Rd. Bldg. 160, Austin, Texas 78758 (United States)

2011-03-21

334

Surface segregation effects of erbium in GaAs growth and their implications for optical devices containing ErAs nanostructures  

NASA Astrophysics Data System (ADS)

We report on the integration of semimetallic ErAs nanoparticles with high optical quality GaAs-based semiconductors, grown by molecular beam epitaxy. Secondary ion mass spectrometry and photoluminescence measurements provide evidence of surface segregation and incorporation of erbium into layers grown with the erbium cell hot, despite the closed erbium source shutter. We establish the existence of a critical areal density of the surface erbium layer, below which the formation of ErAs precipitates is suppressed. Based upon these findings, we demonstrate a method for overgrowing ErAs nanoparticles with III-V layers of high optical quality, using subsurface ErAs nanoparticles as a sink to deplete the surface erbium concentration. This approach provides a path toward realizing optical devices based on plasmonic effects in an epitaxially-compatible semimetal/semiconductor system.

Crook, Adam M.; Nair, Hari P.; Bank, Seth R.

2011-03-01

335

Competition Between Pairing and Quadrupole Deformation in the Yrast Sequence of sup 150 sup 152 Dy.  

National Technical Information Service (NTIS)

The yrast spectra are investigated for the non-collective nuclei sup 150 sup 152 Dy using the Nilsson-Strutinsky + blocked BCS model. The separate effects from the pairing force and the quadrupole force (deformation changes) are studied. It is found that ...

S. Aberg

1984-01-01

336

152. Photocopy of photograph, U.S. Army, ca. 1943 (original print ...  

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

152. Photocopy of photograph, U.S. Army, ca. 1943 (original print located at Rocky Mountain Arsenal, Commerce City, Colorado). R.M.A. - T-125 P.X. & INFIRMARY. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO

337

The stress corrosion cracking behavior of alloys 690 and 152 WELD in a PWR environment  

Microsoft Academic Search

Alloys 690 and 152 are the replacement materials of choice for Alloys 600 and 182, respectively. The latter two alloys are used as structural materials in pressurized water reactors (PWRs) and have been found to undergo stress corrosion cracking (SCC). The objective of this work is to determine the crack growth rates (CGRs) in a simulated PWR water environment for

B. Alexandreanu; O. K. Chopra; W. J. Shack

2009-01-01

338

CHARACTERIZATION OF DEFECTS IN ALLOY 152, 52 AND 52M WELDS  

Microsoft Academic Search

Defect distributions have been documented by optical metallography, scanning electron microscopy and electron backscatter diffraction in alloy 152 and 52 mockups welds, alloy 52 and 52M overlay mockups and an alloy 52M inlay. Primary defects were small cracks at grain boundaries except for more extensive cracking in the dilution zone of an alloy 52 overlay on 304SS. Detailed characterizations of

Stephen M. Bruemmer; Mychailo B. Toloczko; Matthew J. Olszta; Rob J. Seffens; Pal G. Efsing

2009-01-01

339

The stress corrosion cracking behavior of alloys 690 and 152 WELD in a PWR environment.  

SciTech Connect

Alloys 690 and 152 are the replacement materials of choice for Alloys 600 and 182, respectively. The latter two alloys are used as structural materials in pressurized water reactors (PWRs) and have been found to undergo stress corrosion cracking (SCC). The objective of this work is to determine the crack growth rates (CGRs) in a simulated PWR water environment for the replacement alloys. The study involved Alloy 690 cold-rolled by 26% and a laboratory-prepared Alloy 152 double-J weld in the as-welded condition. The experimental approach involved pre-cracking in a primary water environment and monitoring the cyclic CGRs to determine the optimum conditions for transitioning from the fatigue transgranular to intergranular SCC fracture mode. The cyclic CGRs of cold-rolled Alloy 690 showed significant environmental enhancement, while those for Alloy 152 were minimal. Both materials exhibited SCC of 10{sup -11} m/s under constant loading at moderate stress intensity factors. The paper also presents tensile property data for Alloy 690TT and Alloy 152 weld in the temperature range 25--870 C.

Alexandreanu, B.; Chopra, O. K.; Shack, W. J. (Nuclear Engineering Division); ( EVS); ( ESE)

2009-01-01

340

Phase/shape coexistence in {sup 152}Sm in the geometric collective model  

SciTech Connect

It is shown that data on E2 transition rates in {sup 152}Sm can be reproduced in the geometric collective model and that the calculations support the phase/shape coexistence interpretation of this pivotal nucleus. The coexistence is further supported by microscopic calculations, as is the concept of a sudden onset of deformation in this region. (c) 1999 The American Physical Society.

Zhang, Jing-ye [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States) [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); University of Tennessee, Knoxville, Tennessee 37996 (United States); Caprio, M. A. [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States)] [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Zamfir, N. V. [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States) [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Clark University, Worcester, Massachusetts 01610 (United States); National Institute for Physics and Nuclear Engineering, Bucharest-Magurele, (Romania); Casten, R. F. [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States)] [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States)

1999-12-01

341

National Ignition Facility subsystem design requirements supervisory control software SSDR 1.5.2  

SciTech Connect

This System Design Requirement document establishes the performance, design, development, and test requirements for the Supervisory Control Software, WBS 1.5.2, which is part of the NIF Integrated Computer Control System (ICCS). This document responds directly to the requirements detailed in ICCS (WBS 1-5).

Woodruff, J.; VanArsdall, P.; Bliss, E.

1996-08-29

342

Separation of carrier free 151,152Tb produced in 16O irradiated lanthanum oxide matrix.  

PubMed

Charged particle activation of natural La2O3 with approximately 78.5 MeV 16O results in the formation of carrier free 151,152Tb isotopes in the matrix. The liquid cation exchanger, HDEHP, has effectively been utilised as an extractant in the quantitative separation of the activation products from the bulk target matrix of lanthanum oxide. PMID:10581678

Nayak, D; Lahiri, S; Ramaswami, A; Manohar, S B; Das, N R

1999-12-01

343

Study on the exp 152 Gd(N, gamma ) exp 153 Gd Reaction on Resonance Neutrons.  

National Technical Information Service (NTIS)

The exp 152 Gd(n, gamma ) exp 153 Gd reaction was studied on the fast pulse IBR-30 reactor. Gamma-ray spectra following the capture of neutrons in 12.35, 36.86, 39.3, 74.3 and 92.4 eV resonances were measured. Seventeen primary gamma-transitions to exp 15...

F. Becvar J. Honzatko M. Kralik Nguen Dang Nyuan T. Stadnicov

1979-01-01

344

CHARACTERIZATION OF DEFECTS IN ALLOY 152, 52 AND 52M WELDS  

SciTech Connect

Defect distributions have been documented by optical metallography, scanning electron microscopy and electron backscatter diffraction in alloy 152 and 52 mockups welds, alloy 52 and 52M overlay mockups and an alloy 52M inlay. Primary defects were small cracks at grain boundaries except for more extensive cracking in the dilution zone of an alloy 52 overlay on 304SS. Detailed characterizations of the dilution zone cracks were performed by analytical transmission electron microscopy identifying grain boundary titanium-nitride precipitation associated with the intergranular separations. I. INTRODUCTION Weldments continue to be a primary location of stress-corrosion cracking (SCC) in light-water reactor systems. While problems related to heat-affected-zone (HAZ) sensitization and intergranular (IG) SCC of austenitic stainless alloys in boiling-water reactors (BWRs) have been significantly reduced, SCC has now been observed in HAZs of non-sensitized materials and in dissimilar metal welds where Ni-base alloy weld metals are used. IGSCC in weld metals has been observed in both BWRs and pressurized water reactors (PWRs) with recent examples for PWR pressure vessel penetrations producing the most concern. This has led to the replacement of alloy 600/182/82 welds with higher Cr, more corrosion-resistant replacement materials (alloy 690/152/52/52M). Complicating this issue has been a known susceptibility to cracking during welding [1-7] of these weld metals. There is a critical need for an improved understanding of the weld metal metallurgy and defect formation in Ni-base alloy welds to effectively assess long-term performance. A series of macroscopic to microscopic examinations were performed on available mockup welds made with alloy 52 or alloy 152 plus selected overlay and inlay mockups. The intent was to expand our understanding of weld metal structures in simulated LWR service components with a focus on as-welded defects. Microstructural features, defect distributions, defect characteristics and weld residual strains were examined by optical metallography, scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. Industry-supplied mock-up welds were characterized including alloy 52 and 152 weldments, alloy 52M overlay and inlay welds, and an alloy 52 overlay. II. WELDMENTS II.A. Alloy 52 and 152 Weld Mockups The alloy 52 and 152 weld mockups were fabricated by MHI for the Kewaunee reactor and were obtained from the EPRI NDE Center. The mockups were U-groove welds joining two plates of 304SS as shown in Figure 1. Alloy 152 butter (heat 307380) was placed on the U-groove surface for both mockups by shielded metal arc welding (SMAW). For the alloy 152 weld mockup, the alloy 152 fill (heat 307380) was also applied using SMAW while for the alloy 52 weld mockup, the alloy 52 fill (heat NX2686JK) was applied using gas tungsten arc welding (GTAW). Welding parameters for the fill materials were substantially different with the alloy 152 SMAW having a deposition speed of 4-25 cm/min with a current of 95-145 A and the alloy 52 GTAW having a deposition speed of 4-10 cm/min with a current of 150-300 A. One prominent feature in these mockup welds is the presence of a crack starting at the 304SS butt joint at the bottom of the U-groove and extending up into the weld. It appears that the 304SS plate on either side of the butt joint acted as an anchor for the weld resulting in a stress rise across the slit that drove crack formation and extension up into the fill weld. As will be shown in the next section, the extent of the cracking around this stress riser was much greater in the MHI 52 weld mockup.

Bruemmer, Stephen M.; Toloczko, Mychailo B.; Olszta, Matthew J.; Seffens, Rob J.; Efsing, Pal G.

2009-08-27

345

C- and L-band erbium-doped waveguide lasers with wafer-scale silicon nitride cavities.  

PubMed

We report on integrated erbium-doped waveguide lasers designed for silicon photonic systems. The distributed Bragg reflector laser cavities consist of silicon nitride waveguide and grating features defined by wafer-scale immersion lithography and a top erbium-doped aluminum oxide layer deposited as the final step in the fabrication process. The resulting inverted ridge waveguide yields high optical intensity overlap with the active medium for both the 0.98 ?m pump (89%) and 1.5 ?m laser (87%) wavelengths with a pump-laser intensity overlap of >93%. We obtain output powers of up to 5 mW and show lasing at widely spaced wavelengths within both the C and L bands of the erbium gain spectrum (1536, 1561, and 1596 nm). PMID:23862218

Purnawirman; Sun, J; Adam, T N; Leake, G; Coolbaugh, D; Bradley, J D B; Shah Hosseini, E; Watts, M R

2013-06-01

346

A pseudodeficiency allele (D152N) of the human {beta}-glucuronidase gene  

SciTech Connect

We present evidence that a 480G{r_arrow}A transition in the coding region of the {Beta}glucuronidase gene, which results in an aspartic-acid-to-asparagine substitution at amino acid position 152 (D152N), produces a pseudodeficiency allele (GUSBp) that leads to greatly reduced levels of {Beta}-glucuronidase activity without apparent deleterious consequences. The 48OG{r_arrow}A mutation was found initially in the pseudodeficient mother of a child with mucopolysaccharidosis VII (MPSVII), but it was not on her disease-causing allele, which carried the L176F mutation. The 480G{r_arrow}A change was also present in an unrelated individual with another MPSVII allele who had unusually low {Beta}-glucuronidase activity, but whose clinical symptoms were probably unrelated to {Beta}-glucuronidase deficiency. This individual also had an R357X mutation, probably on his second allele. We screened 100 unrelated normal individuals for the 480G{r_arrow}A mutation with a PCR method and detected one carrier. Reduced {Beta}-glucuronidase activity following transfection of COS cells with the D152N cDNA supported the causal relationship between the D152N allele and pseudodeficiency. The mutation reduced the fraction of expressed enzyme that was secreted. Pulse-chase experiments indicated that the reduced activity in COS cells was due to accelerated intracellular turnover of the D152N enzyme. They also suggested that a potential glycosylation site created by the mutation is utilized in {approximately}50% of the enzyme expressed. 25 refs., 3 figs., 3 tabs.

Vervoort, R.; Liebaers, I.; Lissens, W. [Univ. Hospital, Brussels (Belgium)] [and others

1995-10-01

347

Histopathologic and morphometric evaluation of the skin abnormalities induced by erbium:YAG and carbon dioxide lasers in 10 patients.  

PubMed

In the 1960s, carbon dioxide (CO2) laser therapy started to be applied to eliminate wrinkles, actinic scars, and acne because of its capacity of induce intracellular water vaporization. However, recent studies have shown the efficacy of the erbium laser in removing delicate and moderate scars. Furthermore, the postoperative lesions induced by the erbium laser seem to resolve faster and with less erythematous pattern compared with lesions induced by the CO2 laser. The purpose of this study was to determine the immediate pathologic alterations caused by single applications of CO2 and erbium lasers and their association in human skin shreds. Ten white female patients aged 30 to 63 years underwent rhytidectomy, and their respective shreds, which were prepared for excision, were tattooed with the CO2 laser, the erbium laser, or a combination of both in random order and number of applications, before final removal. This project was approved by the local ethical committee. After surgical removal, these tattooed shreds were fixed in 10% buffered formalin and submitted to histopathologic analysis. Morphometric studies demonstrated the normal skin thickness and thickness of the laser-treated area, and their subtraction resulted in the ablation damage values. Residual thermal damage corresponded to the thickness of the affected skin from the most superficial layer of tissue in the laser-treated area down to the deepest dermal area with basophilic degeneration of collagen fibers. Our results showed that two CO2 applications resulted in greater ablation and residual thermal damage when compared with only one CO2 application. The same was true in comparisons of one and two applications of the erbium laser. Both results were statistically significant (p < 0.05). When one isolated erbium and one isolated CO2 application were compared, ablation damage was greater in the former group, although with no statistical significance. One CO2 plus one erbium application compared with one isolated CO2 application showed similar ablation damage but greater residual thermal damage in the latter group (p < 0.05). These observations might contribute to our understanding of the lesions caused in the human skin by erbium and CO2 lasers and eventually help determine the ideal laser combination for the appropriate surgical treatment. PMID:11604648

de Noronha, L; Chin, E W; Menini, C M; Knopfholz, J; Rampazzo, J C; Graf, R

2001-10-01

348

Influence of multimode-pump propagation on the gain characteristics of erbium–ytterbium doped waveguide amplifier  

Microsoft Academic Search

Channel waveguides with channel opening widths (COWs) from 4.5 to 7.5 ?m with increment of 0.5 ?m have been fabricated by\\u000a two-step ion exchange on the same erbium-ytterbium uniformly doped phosphate glass substrate of 4.3-cm length. Experimental\\u000a results indicate that the gain for 1534-nm small signal light pumped at saturation is maximized and shows a 3.6-dB enhancement\\u000a for these erbium-ytterbium doped waveguide

G. Shao; G. Jin; L. Zhan; Q. Li

2009-01-01

349

Silicon nanocluster-sensitized emission from erbium: The role of stress in the formation of silicon nanoclusters  

SciTech Connect

Erbium-doped silicon-rich silicon oxide films deposited by plasma enhanced chemical vapor deposition suffer from compressive stress as deposited, which converts to a large tensile stress on annealing due to the release of hydrogen. Although the cracking that results from this stress can be avoided by patterning the films into ridges, significant stress remains along the ridge axis. Measurements of erbium photoluminescence sensitized by silicon nanoclusters in stressed and relaxed films suggest an important role for internal film stresses in promoting the phase separation of excess silicon into nanoclusters, which has previously been thought of as a thermally driven process.

Ahmad, I.; Kallis, A.; Wojdak, M.; Saleh, H.; Kenyon, A. J. [Department of Electronic and Electrical Engineering, University College London, WC1E 7JE London (United Kingdom); Temple, M. P.; Oton, C. J.; Loh, W. H. [Optoelectronics Research Centre, University of Southampton, SO17 1BJ Southampton (United Kingdom); Barbier, D. [Teem Photonics, 61, Chemin du Vieux Chene 38246 Meylan (France)

2008-12-15

350

Erbium-doped optical amplifiers in amorphous zirconia and relative phase in the directional coupler modulator  

NASA Astrophysics Data System (ADS)

Optical modulators, amplifiers and couplers are key components of optical communications systems, enabling signal generation, routing, conditioning and transmission over long distances. This work details the investigation of three aspects of these devices: Erbium-doped waveguide amplifiers in amorphous zirconia, directional coupler modulators with linear intensity response, and the theory and design of optical directional coupler devices. The attainment of large gain and wide bandwidth in Erbium-doped waveguide amplifiers requires a host material that offers a high degree of optical activity, as well as broad spectral luminescence. In the first part of this work, the optical characteristics of Erbium-doped, ion-beam sputtered amorphous zirconia (ZrO2/SiO2) have been examined in these respects, and optical amplifiers have been developed. The second part of this work involves the development of linear-response optical modulators for analog systems. Such devices are of interest for a variety of applications including microwave distribution networks, phased-array radar, test equipment and sensors, in which linearity is important for system performance. This work has studied the use of optical phase shifts in the directional coupler modulator to provide linear intensity modulation, and used them to demonstrate one of the most efficient linear modulator designs to date. The final portion of this work deals with the theory and design of directional coupler devices, relevant to a wide range of optical components including modulators, filters, dispersion compensators and tunable lasers. The coupled-mode equations describing the directional coupler have been reformulated in such a way as to reveal the strong relationship between power transfer and the phase of the optical fields. This has also been used to produce a graphical chart, which plots field progression in the directional coupler, and allows these devices to be designed in a more intuitive manner than traditional numerical techniques.

Schermer, Ross Timothy

351

Performance characterization of new erbium-doped fibers using MCVD nanoparticle doping process  

NASA Astrophysics Data System (ADS)

In 2009, we introduced a new doping concept involving Al2O3/rare-earth nanoparticles (NP) in a MCVD-compatible process finding potential applications in Erbium-, Ytterbium- or Erbium-Ytterbium-doped fiber amplifiers and lasers.1 This approach, motivated by the need for increased efficiencies and improved attributes, is characterized by the ability to control the rare-earth ion environment independently from the core composition. The NP matrix can therefore be viewed as an optimized sub-micronic amplifying medium for the embedded rareearth ion. The first experimental evidence to support this idea is reported in a comparative study with a standard process2 where homogeneous up-conversion (HUC) and pair-induced quenching (PIQ) levels are extracted from Er3+ unsaturable absorption measurements. NP-based fibers are found to mitigate the effects of the Er3+ concentration increase seen in standard heavily-doped fibers. This conclusion is particularly clear when focusing on the HUC coefficient evolution since, for a given type of NP, its level is independent from the Er3+ concentration in the doped zone. In this paper, we address our most recent work completing these preliminary results. First, we investigate the quenching signature of a new NP design and its behavior when incorporated in different core matrices. The interplay is further analysed by relating this set of measurements to practical EDFA performances. Gain and noise characteristics of typical WDM amplifiers operating points serve as key benchmarking indicators to identify the benefits of NP Erbium-doped fibers in the wide variety of EDFAs implementations.

Boivin, David; Pastouret, Alain; Burov, Ekaterina; Gonnet, Cédric; Cavani, Olivier; Lempereur, Simon; Sillard, Pierre

2011-02-01

352

Effects of the holmium:YAG and erbium:YAG lasers on endotracheal tubes.  

PubMed

Endotracheal tube (ET) fire is the most frequent complication arising with laser surgery in the upper aerodigestive tract. No data are available about the safety of commonly used ETs when used with recently developed high-energy pulsed lasers, working with only a minimal thermal component but mainly photoablative. A comparative in vitro study was performed with three types of endotracheal tubes to assess their resistance to wall and cuff damage by the laser beams of two pulsed infrared solid-state lasers. ET perforation was attempted with the erbium:YAG (lambda = 2,930 nm) and holmium:YAG (lambda = 2,120 nm) lasers. For all experiments, a repetition rate of 5 Hz was used. The 2.5-microseconds holmium:YAG pulses were coupled into a nylon fibre of 400 microns diameter. The 2.0-microseconds erbium:YAG laser pulses were applied to ETs through a lens system providing a spot size diameter of 200 microns. Polyvinyl chloride and silicon ET segments were exposed to laser pulse energies from 97 to 500 mJ in the presence of different anaesthetic gas mixtures. The time from the onset of exposure to tube perforation was recorded. Thermal gradients following laser application were measured. Laser exposure was continued for up to 90 s, unless tube ignition occurred. At all energy levels tested, the photo-ablative mechanism of laser-tube interaction, with few thermal components, led to laser-induced tube ignition if an FiO2 > 21% for the holmium:YAG and 34% for the erbium:YAG laser was established. With increasing pulse energies, ET segments ignited sooner. MLT tubes performed best in the present safety test. PMID:8446385

Kautzky, M; Fitzgerald, R; Dechtyar, I; Schenk, P

1993-01-01

353

OPTICAL EMISSION OF THE BLACK HOLE X-RAY TRANSIENT MAXI J1659-152 DURING QUIESCENCE  

SciTech Connect

We report on the optical detection of the black hole X-ray transient MAXI J1659-152 during its quiescent state. By using the Canada-France-Hawaii Telescope, we observed MAXI J1659-152 about seven months after the end of an X-ray outburst. The optical counterpart of MAXI J1659-152 is clearly detected with an r'-band magnitude of 23.6-23.8. The detection confirms that the optical emission of MAXI J1659-152 during quiescence is relatively bright compared to other black hole X-ray transients. This implies that the distance to MAXI J1659-152 is 4.6-7.5 kpc for an M2 dwarf companion star or 2.3-3.8 kpc for an M5 dwarf companion star. By comparing with other measurements, an M2 dwarf companion is more likely.

Kong, Albert K. H., E-mail: akong@phys.nthu.edu.tw [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

2012-12-01

354

Pulpal response to cavity preparation by an erbium, chromium:YSGG laser-powered hydrokinetic system.  

PubMed

The near red-pulsed erbium, chromium:yttrium-scandium-gallium-garnet laser hydrokinetic system, or Er,Cr:YSGG laser HKS, is effective in cutting dental hard tissues. In this longitudinal study, the authors studied the continuously erupting open-apex incisors of New Zealand albino rabbits and the constricted apex teeth of beagles to determine the effects of HKS-produced lesions at various energy levels and of preparations produced by a tapered fissure bur on dental pulp. No pulpal inflammatory responses could be identified either immediately or 30 days after surgery in HKS preparations that removed enamel and dentin without pulp exposure. PMID:9260419

Eversole, L R; Rizoiu, I; Kimmel, A I

1997-08-01

355

A dual-wavelength erbium-doped fiber laser with widely tunable wavelength spacing  

NASA Astrophysics Data System (ADS)

A stable dual-wavelength erbium-doped fiber laser (EDFL) with tunable wavelength spacing and equalized output power is proposed and experimentally demonstrated. The fiber laser uses two fiber Fabry-Perot tunable filters (FFPTFs) as the wavelength filter. The main cavity is divided into two sub-cavities with imbalance cavity losses through a 30/70 optical coupler. The tunable wavelength spacing can be achieved by changing the center wavelength of the filters and the equalized dual-wavelength output power can be achieved by properly controlling the variable optical attenuator (VOA) inserted in the lower-loss cavity.

Zhang, Wei-hua; Tong, Zheng-rong; Cao, Ye

2014-03-01

356

Fibercore AstroGain fiber: multichannel erbium doped fibers for optical space communications  

NASA Astrophysics Data System (ADS)

Fibercore have developed AstroGainTM fiber optimized for multichannel amplifiers used in optical satellite communications and control. The fiber has been designed to take full advantage of the photo-annealing effect that results from pumping in the 980nm region. The proprietary trivalent structure of the core matrix allows optimum recovery following radiation damage to the fiber, whilst also providing a market leading Erbium Doped Fiber Amplifier (EDFA) efficiency. Direct measurements have been taken of amplifier efficiency in a multichannel assembly, which show an effective photo-annealing recovery of up to 100% of the radiation induced attenuation through excitation of point defects.

Hill, Mark; Gray, Rebecca; Hankey, Judith; Gillooly, Andy

2014-03-01

357

Graphene Oxide-Based Q-Switched Erbium-Doped Fiber Laser  

NASA Astrophysics Data System (ADS)

We demonstrate a pulsed ring erbium-doped fiber laser based on graphene oxide (GO), employing a simplified Hummer's method to synthesize the GO via chemical oxidation of graphite flakes at room temperature. By dipping a fiber ferrule end face onto the GO suspension, GO is successfully coated onto the end face, making it a simple saturable absorption device. A stable Q-switched pulsed fiber laser is achieved with a low pump threshold of 9.5 mW at 980 nm. The pulse repetition rate ranges from 16.0 to 57.0 kHz. The pulse width and the pulse energy are studied and discussed.

Yap, Y. K.; Huang, N. M.; Harun, S. W.; Ahmad, H.

2013-02-01

358

Propagation properties of soliton solutions under the influence of higher order effects in erbium doped fibers  

NASA Astrophysics Data System (ADS)

Under investigation in this paper is the Hirota-Maxwell-Bloch system which governs the propagation of optical solitons in nonlinear erbium doped fibers with higher order effects. By virtue of the Darboux transformation, the Akhmediev breathers, Ma-breathers, localized solitons, bound solitons, two-breathers and localized solutions are generated for the Hirota-Maxwell-Bloch system. Considering the influences of higher order effects, propagation properties of the breathers, modulation instability conditions for the Akhmediev breathers and interaction scenarios between bound solitons and two-breather solutions are discussed.

Guo, Rui; Hao, Hui-Qin

2014-10-01

359

Acid resistance of dentin after erbium:yttrium-aluminum-garnet laser irradiation  

Microsoft Academic Search

The purpose of this study was to evaluate the acid resistance of erbium:yttrium-aluminum-garnet (Er:YAG) lased sub-surface\\u000a dentin using a scanning electron microscope (SEM). Dentin disks were exposed to a single pulse of Er:YAG laser irradiation\\u000a at 80 mJ\\/pulse under water spray, with the contact sapphire tip vertical to the dentin surfaces (n?=?15). Five specimens from the laser-ablated dentin surfaces were observed.

Zhengdi He; Masayuki Otsuki; Alireza Sadr; Junji Tagami

2009-01-01

360

Adhesion after erbium, chromium:yttrium-scandium-gallium-garnet laser application at three different irradiation conditions  

Microsoft Academic Search

The aim of this study was to investigate whether distinct cooling of low fluence erbium, chromium:yttrium-scandium-gallium-garnet\\u000a (Er,Cr:YSGG) laser irradiation would influence adhesion. Main factors tested were: substrates (two), irradiation conditions\\u000a (three), and adhesives (three). A 750 ?m diameter tip was used, for 50 s, 1 mm from the surface, with a 0.25 W power output,\\u000a 20 Hz, energy density of 2.8 J\\/cm2 with energy per pulse

Sérgio Brossi Botta; Patricia Aparecida da Ana; Denise Maria Zezell; John M. Powers; Adriana Bona Matos

2009-01-01

361

LASERS: Transversely diode-pumped passively Q-switched erbium glass laser emitter  

NASA Astrophysics Data System (ADS)

The properties of a laser diode array-pumped passively Q-switched ytterbium-erbium glass laser emitter are studied. It is found experimentally that the maximum output energy is achieved when the diameter of the TEM00 mode is 0.65-0.77 of the transverse size of the active element. By using two 100-W linear laser diode arrays with the output power not exceeding 70% of the maximum power, 5 mJ was achieved in a 50-ns diffraction-limited single pulse for the efficiency (with respect to the pump radiation energy) of 1.35%.

Bykov, V. N.; Izyneev, A. A.; Sadovoi, A. G.; Sadovskii, P. I.; Sorokina, O. A.

2008-03-01

362

Subpicosecond soliton compression of gain switched diode laser pulses using an erbium-doped fiber amplifier  

NASA Astrophysics Data System (ADS)

Subpicosecond pulse generation and control are important issues required for ultrafast optoelectronic information transfer or measurements. Combining a gain switched semiconductor laser, an erbium-doped fiber amplifier, and two cascaded fibers for compression, optical pulse trains of 0.63 ps FWHM in autocorrelation trace, with certain suppression of wing structures are successfully generated. Evaluated energy in each pulse was less than or = 17 pJ. Computer simulation was performed on soliton effect compression of gain switched pulses containing substantial chirp and an optimization procedure of simply controlling the dc bias current on the master DFB laser was clarified.

Ong, Johnson Teng; Takahashi, Ryo; Tsuchiya, Masahiro; Wong, Sheng-Hsien; Sahara, Richard T.; Ogawa, Yoh; Kamiya, Takeshi

1993-06-01

363

Photoluminescence of porous silicon stain etched and doped with erbium and ytterbium  

NASA Astrophysics Data System (ADS)

A novel low cost process has been developed for application in porous silicon-based photodetectors and solar cells, where conventional doping processes are not affordable because of the high processing cost and technical difficulties. Ytterbium and erbium (Yb 3+-Er 3+) ions were introduced into luminescent porous silicon stain etched by thermal diffusion. Doping profiles were evaluated by energy-dispersive spectroscopy analysis. The visible and near-infrared photoluminescence of Yb 3+-Er 3+ co-doped stain-etched porous silicon layers is observed and evaluated under 980 nm pumping. Up-conversion processes that could improve the efficiency of silicon-based solar cells are detected.

Díaz-Herrera, B.; González-Díaz, B.; Guerrero-Lemus, R.; Hernández-Rodríguez, C.; Méndez-Ramos, J.; Rodríguez, V. D.

2009-02-01

364

Erbium Doping Effects on the Conduction Band Edge in Germanium Nanocrystals  

SciTech Connect

We have produced erbium-doped germanium nanocrystals (NCs) using a new two cell physical vapor deposition system. Using element specific x-ray techniques (absorption and photoemission), we are able to probe the chemical environment of Er in the Ge NCs. Evidence for the optically active Er3+ state is seen at low Er concentrations, with a disruption of NC formation at high Er concentrations. The x-ray absorption measurements suggest that the Er occupies lattice sites near the surface of the NC. Analysis of the quantum confinement effect with Er doping suggests that the native quantum properties of the Ge NC are maintained at low Er concentrations.

Meulenberg, Robert W.; Willey, Trevor M.; Lee, Jonathan R.; Terminello, Louis J.; Van Buren, T.

2011-05-16

365

Physical and biological dosimetry in patients undergoing radiosynoviorthesis with erbium-169 and rhenium-186.  

PubMed

Physical and biological dosimetry were investigated in 45 rheumatoid arthritis patients treated by radiosynoviorthesis (RSO) with 186Re-sulphide (medium-sized joints) and 169Er-citrate (digital joints). Biological dosimetry involved scoring dicentrics in lymphocytes, cultured from blood samples withdrawn just before and 6 h, 24 h and 7 days after treatment. Physical methods included repeated blood sample counts and scintigraphy data. For erbium-169 (pure beta emitter), only bremsstrahlung could be measured and solely in the injection area. For rhenium-186 (both beta and gamma emitter), whole body scans and static images of joints and locoregional lymph nodes were performed. Dosimetry calculations were in accordance with the MIRDOSE 3 software and tables. For erbium-169 (21 patients), either metacarpophalangeal (30 MBq) or proximal interphalangeal (20 MBq) joints of the hands were treated (one joint per patient); 18 patients (out of 21) were interpretable for biological dosimetry, 10 (out of 11) for physical dosimetry and six (out of 10) for both. For rhenium-186, 23 wrists, nine elbows, three shoulders and two ankles were injected in 24 patients, with a maximum of three joints per patient (70 MBq per joint); 20 patients (out of 24) and 10 (out of 10) were interpretable for biological and physical dosimetry, respectively, and eight (out of 10) for both methods. Erbium-169 biological dosimetry was negative in all interpretable patients, and physical dosimetry gave a blood dose of 15 +/- 29 microGy and an effective dose lower than 1 mSv/30 MBq. For rhenium-186, biological results were negative in 16 patients (out of 20), but showed a blood irradiation around 200 mGy in the last four. A significant cumulative increase of dicentrics 7 days after injection (16/10,000 instead of 5/10,000 prior to treatment; p < 0.04) was also noted. Gamma counts gave a blood dose of 23.9 +/- 19.8 mGy/70 MBq and the effective dose was found to be 26.7 +/- 5.1 mGy/70 MBq, i.e. about 380 microGy.MBq-1. Erbium-169 RSO is very safe from both physical and biological dosimetry standpoints. Rhenium-186 leak is greater, as demonstrated by the higher blood activity and the measurable, although limited, dicentrics induction in blood lymphocytes. However, the effective dose remains moderate, i.e. 30 times lower than in 131I therapy in benign thyroid diseases. PMID:11338051

Manil, L; Voisin, P; Aubert, B; Guerreau, D; Verrier, P; Lebègue, L; Wargnies, J P; Di Paola, M; Barbier, Y; Chossat, F; Menkes, C J; Tébib, J; Devaux, J Y; Kahan, A

2001-04-01

366

Propagation of dispersion-nonlinearity-managed solitons in an inhomogeneous erbium-doped fiber system  

NASA Astrophysics Data System (ADS)

In this paper, a generalized nonlinear Schrödinger-Maxwell-Bloch model with variable dispersion and nonlinearity management functions, which describes the propagation of optical pulses in an inhomogeneous erbium-doped fiber system under certain restrictive conditions, is under investigation. We derive the Lax pair with a variable spectral parameter and the exact soliton solution is generated from the Bäcklund transformation. It is observed that stable solitons are possible only under a very restrictive condition for the spectral parameter and other inhomogeneous functions. For various forms of the inhomogeneous dispersion, nonlinearity and gain/loss functions, construction of different types of solitary waves like classical solitons, breathers, etc is discussed.

Mahalingam, A.; Porsezian, K.; Mani Rajan, M. S.; Uthayakumar, A.

2009-04-01

367

ARTICLES: Active mode locking in an yttrium erbium aluminum garnet crystal laser (? = 2.94?)  

NASA Astrophysics Data System (ADS)

A constant-temperature yttrium erbium aluminum garnet crystal laser was actively mode locked by resonant modulation of the resonator losses using a lithium niobate electrooptic modulator with Brewster faces without any polarizers. This gave a modulation depth 2.6 times greater than that for a modulator with an ideal polarizer. A spike energy of ~1 mJ was obtained with an estimated duration of 200 psec in the 1.7 mm diameter TEM00 mode. The laser radiation was elliptically polarized. It was found that three-micron radiation could be recorded using an SNF-T photomultiplier.

Vodop'yanov, K. L.; Kulevski?, L. A.; Malyutin, A. A.; Pashinin, Pavel P.; Prokhorov, A. M.

1982-05-01

368

Spin-slip transitions in erbium induced by a magnetic field  

NASA Astrophysics Data System (ADS)

NGR studies ( 119Sn) and measurements of the magnetization of single crystal erbium revealed an interrelation between the cone angle of the magnetic moments and the spin-slip states in the basal plane. The obtained data are used to identify these states. The proof is presented for the first time that the hyperfine fields on nuclei of a nonmagnetic impurity in rare earth metals (REM) are produced in the regions with the smallest radii (of the order of interplanar distance). It is found that the transitions between commensurable magnetic structures can be caused not only by temperature but also by a magnetic field.

Godovikov, S. K.; Nikitin, S. A.; Tishin, A. M.

1991-09-01

369

CONTROL OF LASER RADIATION PARAMETERS: Passive Q switches for a diode-pumped erbium glass laser  

NASA Astrophysics Data System (ADS)

A diode-pumped, passively Q-switched 1.54-?m erbium glass laser is studied. Zinc selenide (ZnSe) crystals doped with Co2+ and Cr2+ ions and magnesium—aluminium spinel (MgAl2O4) crystals doped with Co2+ ions were used as saturable absorbers in Q switches. It is shown that, depending on the type of a saturable absorber, the pump power, and the resonator design, the laser pulse energy can vary from 0.2 to 13 ?J, the pulse duration from 16 to 980 ns, and the pulse repetition rate from 0.1 to 30 kHz.

Kisel', V. E.; Shcherbitskii, V. G.; Kuleshov, N. V.; Postnova, L. I.; Levchenko, V. I.; Galagan, B. I.; Denker, B. I.; Sverchkov, S. E.

2005-07-01

370

Hydroxide complexes of lanthanides-V Erbium(III) in perchlorate medium.  

PubMed

From the precipitation borderline in the pM'-pC(H) diagram, determined experimentally under CO(2)-free conditions, stability constants for the mononuclear species of erbium hydroxide have been established. The values found were log ( *)beta(1) = -6.3, log ( *)beta(2) = -14.5, log ( *)beta(3) = -23.1, log ( *)beta(4) = -36.8 and log ( *)K(0) = 18.0. The data refer to precipitates prepared at room temperature (21.5 +/- 0.5 degrees ) in sodium perchlorate medium with an ionic strength of 1. The formation of polynuclear hydroxide complexes has been considered and rejected as unlikely to occur. PMID:18963332

Kragten, J; Decnop-Weever, L G

1983-02-01

371

Di2-pyridyl ketone in lanthanide(III) chemistry: Mononuclear and dinuclear erbium(III) complexes  

Microsoft Academic Search

The use of di-2-pyridyl ketone ((py)2CO)\\/SCN? “blend” in erbium(III) chemistry has yielded mononuclear and dinuclear complexes. The ErIII\\/SCN?\\/(py)2CO reaction mixture in alcohols (MeOH, EtOH) gives complexes [Er(NCS)3{(py)2C(OR)(OH)}3] (R=Me (1), Et (2)), where (py)2C(OR)(OH) is the neutral hemiacetal derivative of (py)2CO. Incorporation of hydroxides in the methanolic reaction system leads to the isolation of [Er2(NCS)3{(py)2C(OMe)O}3(MeOH)] (3). Complex 3 can also be

Katerina A. Thiakou; Vassilios Nastopoulos; Aris Terzis; Catherine P. Raptopoulou; Spyros P. Perlepes

2006-01-01

372

Isomeric yield ratios in nuclei {sup 190}Ir and {sup 150,152}Eu  

SciTech Connect

Isomeric yield ratios {sup 190}Ir{sup m2,m1+g}, {sup 150}Eu{sup m,g}, {sup 152}Eu{sup m1,m2} have been measured in ({gamma},n)-reactions for the end point energies of bremsstrahlung photons about 12, 12.5, and 16 MeV for {sup 190}Ir{sup m2,m1+g} and 12 MeV for {sup 150}Eu{sup m,g}, {sup 152}Eu{sup m1,m2}. Experimental values of the isomeric yield ratios have been compared with the theoretical values, which were calculated by using codes TALYS and MCEM. The low influence of nonstatistical effects has been observed for all these energies.

Vishnevsky, I. N.; Zheltonozhsky, V. A.; Savrasov, A. N.; Strilchuk, N. V. [Institute for Nuclear Research, National Academy of Science, 03680 Kiev (Ukraine)

2009-01-15

373

Enhancement of Spontaneous Erbium Emission near the Photonic Band Edge of Distributed Bragg Reflectors Based on a-Si:H/a-SiO{sub x}:H  

SciTech Connect

Results obtained in an experimental study of spontaneous emission from erbium ions in a spectral range corresponding to the lower photonic band edge of distributed Bragg reflectors (1D photonic crystals) are presented. The photonic crystals were constituted of alternating quarter-wave a-Si:H and a-SiO{sub x}:H layers grown by PECVD. Erbium was introduced into the a-Si:H layers by magnetron sputtering of an erbium target in the course of structure growth. The change observed in the intensity of spontaneous emission is due to the nonmonotonic behavior of the density of optical modes near the photonic band edge.

Medvedev, A.V.; Feoktistov, N.A.; Pevtsov, A.B.; Golubev, V.G. [Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021 (Russian Federation)

2005-11-15

374

PREDICTING THE CONFIGURATION OF A PLANETARY SYSTEM: KOI-152 OBSERVED BY KEPLER  

SciTech Connect

The recent Kepler discovery of KOI-152 reveals a system of three hot super-Earth candidates that are in or near a 4:2:1 mean motion resonance. It is unlikely that they formed in situ; the planets probably underwent orbital migration during the formation and evolution process. The small semimajor axes of the three planets suggest that migration stopped at the inner edge of the primordial gas disk. In this paper, we focus on the influence of migration halting mechanisms, including migration 'dead zones', and inner truncation by the stellar magnetic field. We show that the stellar accretion rate, stellar magnetic field, and the speed of migration in the protoplanetary disk are the main factors affecting the final configuration of KOI-152. Our simulations suggest that three planets may be around a star with low star accretion rate or with high magnetic field. On the other hand, slow type I migration, which decreases to one-tenth of the linear analysis results, favors forming the configuration of KOI-152. Under such a formation scenario, the planets in the system are not massive enough to open gaps in the gas disk. The upper limits of the planetary masses are estimated to be about 15, 19, and 24 M{sub Circled-Plus }, respectively. Our results are also indicative of the near Laplacian configurations that are quite common in planetary systems.

Wang Su; Ji Jianghui [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Zhou Jilin, E-mail: wangsu@pmo.ac.cn, E-mail: jijh@pmo.ac.cn [Department of Astronomy and Key Laboratory of Modern Astronomy and Astrophysics in Ministry of Education, Nanjing University, Nanjing 210093 (China)

2012-07-10

375

Rotational structures and their evolution with spin in {sup 152}Gd  

SciTech Connect

The fusion-evaporation reaction involving a 175 MeV {sup 36}S beam and a {sup 124}Sn target was performed, and the emitted {gamma} rays were observed with the Gammasphere spectrometer. Significant additions to the level scheme of {sup 152}Gd were made in spite of the relative weakness of the {alpha}4n exit channel, being only {approx}2% of the total fusion cross-section. The high-spin behavior of {sup 152}Gd was compared with that of other N=88 nuclei. A striking similarity was observed with {sup 154}Dy and it is therefore suggested that the angular-momentum-induced shape changes that take place in {sup 154}Dy also occur in {sup 152}Gd in the 30-40h spin range. This is supported by Cranked Nilsson-Strutinsky calculations which were used to interpret the high-spin bands. It is found that a better agreement between calculation and experiment is obtained if the Z=64 shell gap increases with a decreasing number of valence particles outside the doubly-closed {sub 64}{sup 146}Gd{sub 82} nucleus.

Campbell, D. B. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Laird, R. W. [Department of Physics, Texas Lutheran University, Seguin, Texas 78023 (United States); Riley, M. A. [Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States); Simpson, J. [CCLRC Daresbury Laboratory, Daresbury, Warrington, WA4 4AD (United Kingdom); Kondev, F. G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Hartley, D. J. [Department of Physics, United States Naval Academy, Annapolis, Maryland 21402 (United States); Janssens, R. V. F.; Carpenter, M. P.; Lauritsen, T.; Nisius, D. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Brown, T. B. [Savannah River National Laboratory, Aiken, South Carolina 29802 (United States); Fallon, P. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Fischer, S. M. [Department of Physics, DePaul University, Chicago, Illinois 60614-3504 (United States); Ragnarsson, I. [Division of Mathematical Physics, LTH, Lund University, Box 118, S-221 00, Lund (Sweden)

2007-06-15

376

Breathers and localized solitons for the Hirota-Maxwell-Bloch system on constant backgrounds in erbium doped fibers  

NASA Astrophysics Data System (ADS)

In nonlinear erbium doped fibers, the Hirota-Maxwell-Bloch system with higher order effects usually governs the propagation of ultrashort pulses. New soliton solutions for this system are constructed on the constant backgrounds including one and two breathers and first and higher order localized soliton solutions. Considering the influence of higher order effects, propagation properties of those soliton solutions are discussed.

Guo, Rui; Hao, Hui-Qin

2014-05-01

377

Passive gain-equalized wide-band erbium-doped fiber amplifier using samarium-doped fiber  

Microsoft Academic Search

A passive gain-equalization technique of erbium-doped fiber amplifier (EDFA) using a samarium-doped fiber to obtain wide-band flattened gain operation is reported. In the wavelength range from 1529-1559-nm, small inter-channel gain variations can be achieved. This simple technique is suitable for multiwavelength wide-band in-line-amplifier cascaded transmission applications.

Shien-Kuei Liaw; Yung-Kuang Chen

1996-01-01

378

Actively gain-flattened erbium-doped fiber amplifier over 35 nm by using all-fiber acoustooptic tunable filters  

Microsoft Academic Search

We demonstrate an actively gain-flattened erbium-doped fiber amplifier (EDFA) using an all-fiber gain-flattening filter with electronically controllable spectral profiles. A good gain flatness (35 nm) is achieved for a wide range of operational gain levels as well as input signal and pump powers

Hyo Sang Kim; Seok Hyun Yun; Hyang Kyun Kim; Byoung Yoon Kim

1998-01-01

379

Thermodynamic model of the stabilization of an intermediate state in the region of the metamagnetic phase transition in erbium orthoferrite  

NASA Astrophysics Data System (ADS)

The possible mechanisms of the thermodynamic stabilization of an intermediate state in the first-order metamagnetic phase transition in a magnetic field parallel to the Ising c axis of the Er3+ ions in erbium orthoferrite at T = 1.6 K have been analyzed. The model is chosen using the magneto-optical experimental data on the features of this state.

Belyaeva, A. I.; Baranova, E. V.

2007-07-01

380

91-km attenuation-free transmission with low noise accumulation by use of distributed erbium-doped fiber  

NASA Astrophysics Data System (ADS)

Transparency of a 91-km distributed erbium-doped fiber is achieved with 0.46 mW / km of pump power at a signal power of -12dBm . The accumulation of amplifier noise is measured to be smaller than the minimum noise accumulation that can be achieved in a 91-km link with two lumped amplifiers separated by 45 km.

Lester, Christian; Rottwitt, Karsten; Povlsen, Jørn H.; Varming, Poul; Newhouse, Mark A.; Antos, A. J.

1995-06-01

381

The use of the erbium yttrium aluminium garnet (2,940 nm) in a laser-assisted apicectomy procedure  

Microsoft Academic Search

If conventional endodontic treatment is not possible or not successful, apical endodontic surgery may be indicated. New techniques, materials and technologies have been used to increase the already high success rate of root canal treatment. The purpose of this article is to describe the use of the Erbium:YAG (2,940 nm) laser in treatment of apicectomy as a central tool, with

S. Parker; J. Moshonov; A. Reyhanian

2008-01-01

382

Acoustical measurements during Erbium:YAG laser ablation of porcine calcified tissues  

NASA Astrophysics Data System (ADS)

The Erbium:YAG laser ((lambda) equals 2.94 micrometer) has been suggested for use in dental, orthopedic, and middle ear surgery due to decreased thermal trauma, precise ablation characteristics, and potential fiber optic delivery. While there has been much focus on the thermal and photoacoustic events that occur during pulsed laser ablation of hard tissue, there are few studies that examine the acoustic energy generated by these devices during ablation from an audiologic standpoint. In this study, the porcine otic capsule, nasal bone, and teeth were irradiated with an Erbium:YAG laser. Frequencies of 5 and 10 Hz shot repetition rate were used with .5 to 4 W average power. Additionally, a burst mode consisting of three pulses was used with .2 to 1.4 J total energy. During ablation, acoustic measurements were made using a sound level meter held 20 mm away from the target site. A constant spot size of 500 micrometer was maintained for each laser blast. With each set of laser parameters, the sound intensity (dB SPL) exceeded 70 dB. Peak intensity measurements of 95 dB were measured. The clinical significance of these findings is discussed and the acoustical aspects of middle ear function and noise trauma are reviewed.

Saaf, Randall R.; Wong, Brian J.; Milner, Thomas E.; Peavy, George M.; Anvari, Bahman

1998-07-01

383

Experimental and numerical study of high order Stokes lines in Brillouin-erbium fiber laser  

NASA Astrophysics Data System (ADS)

We experimentally study the dependences of high-order Stokes lines on the erbium-doped fiber (EDF) pump power P, the Brillouin pump (BP) power P, and its working wavelength in a multiwavelength Brillouin erbium-doped fiber laser (MBEFL). By using the rate and propagation equations, and the coupled wave equations of stimulated Brillouin scattering, we establish a lumped model to describe the MBEFL. Numerical simulations show that the number of Stokes lines can be increased by decreasing the spacing between the BP wavelength and the EDF peak gain or P as long as it is larger than a critical value PBP(cr)=1.7 mW, or by increasing P without reaching a saturation value PEDF(cr)=250 mW. However, when P and P are varied beyond PBP(cr) and PEDF(cr), respectively, the number of Stokes lines is reduced, accompanied by some self-lasing cavity modes. These results by numerical simulation are consistent with experimental observations from the MBEFL.

Yuan, Yijun; Yao, Yong; Xiao, Jun Jun; Yang, Yanfu; Tian, Jiajun; Liu, Chao

2014-01-01

384

Tunable microwave photonic filter based on a fiber ring and erbium-doped fiber amplifier  

NASA Astrophysics Data System (ADS)

The tunable microwave photonic filter based on a fiber ring and erbium-doped fiber amplifier (EDFA) was proposed. By introducing a section of erbium-doped fiber (EDF) into the fiber ring, the loss of the signal can be compensated by the EDFA gain through adjusting the pump power. This can largely increase the number of the effective sampling taps, and then improve the performance of the microwave photonic filter notably. When the pump power was set to be 42.7 mW, a microwave bandpass filter with the 3-dB bandwidth of 0.15 MHz, the Q factor up to 100 and extinction ratio up to 20 dB was achieved. By employing a tunable optical delay line in the above fiber ring, a tunable microwave photonic filter has been realized through tuning the length of the optical delay line. The proposed tunable microwave photonic filter can find great applications in microwave signal processing and ROF system.

Fu, Hong-Yan; Ou, Hai-Yan; Chen, Da-Ru; Xiao, Yun; He, Sai-Ling

2007-11-01

385

Crystal structure and magnetic properties of potassium erbium double tungstate KEr(WO4)2  

NASA Astrophysics Data System (ADS)

Results of structural, magnetic and specific heat investigations of the potassium erbium double tungstate, KEr(WO4)2, are presented. Potassium erbium double-tungstate KEr(WO4)2 single crystals have been grown by the top-seeded solution growth method (TSSG) and modified Czochralski techniques. It crystallizes in the monoclinic crystal structure (C 2/c space group). The unit cell contains four formula units and is described by parameters a = 10.615(2) Å, b = 10.316(2) Å, c = 7.534(2) Å, ? = 130.73(3)°. From the x-ray diffraction measurements the fractional atomic coordinates, displacement parameters and interatomic distances have been determined. The specific heat C(T) of the KEr(WO4)2 crystal has been measured over a temperature range of 0.6-300 K. The susceptibility has been studied at T = 0.25-4.0 K. The magnetic phase transition was observed at a temperature of 0.48 K. The magnetization has been measured in the temperature region from 4.2 to 60 K and in magnetic field up to 1.6 T. A strong anisotropy of magnetic properties was found. The temperature and field dependences of susceptibility and magnetization data were used for both elucidation of character of the magnetic ordering and calculation of the exchange and dipole-dipole interaction energies as well as for determination of the possible magnetic structure of KEr(WO4)2.

Borowiec, M. T.; Dyakonov, V. P.; Wozniak, K.; Dobrzycki, L.; Berkowski, M.; Zubov, E. E.; Michalski, E.; Szewczyk, A.; Gutowska, M. U.; Zayarnyuk, T.; Szymczak, H.

2007-02-01

386

Synthesis of erbium-doped gallium nitride crystals by the ammonothermal route  

NASA Astrophysics Data System (ADS)

Gallium nitride (GaN) crystals doped with erbium were grown via the ammonothermal processes on hydride vapor phase epitaxy (HVPE) GaN seeds. The crystallization conducted in alkaline solutions of supercritical ammonia and potassium azide (KN 3) at temperatures between 525 and 550 °C yielded growth rates of 15 and 50 ?m day on the gallium and nitrogen polar faces, respectively. X-ray diffraction studies indicated single-crystalline growth on the N-polar surface while the Ga-polar surfaces resulted in polycrystalline growth. Photoluminescence spectra acquired at 15 K showed optical transitions corresponding to the inner shell transitions of erbium centers as well as a strong band edge and blue luminescence peaks centered at 3.495 and 2.90 eV, respectively. The incorporation of unintentional impurities, such as oxygen, was found by secondary ion mass spectroscopy (SIMS) to be mitigated to ˜1×10 19 and ˜7×10 19 cm -3 on the gallium and nitrogen polar faces, respectively.

Adekore, B. T.; Callahan, M. J.; Bouthillette, L.; Dalmau, R.; Sitar, Z.

2007-10-01

387

Effect of the capping ligand on luminescent erbium(III) ?-diketonate single-ion magnets.  

PubMed

Erbium complexes featuring ?-diketonate ligand 2,4-hexanedione (Hh) and N,N-donor-ligands 2,2'-bipyridine (bipy), 5-nitro-1,10-phenanthroline (5NO2phen) and bathophenanthroline (bath) have been synthesized. The structures of the ternary complexes [Er(h)3(bipy)], [Er(h)3(5NO2phen)] and [Er(h)3(bath)] have been determined by single crystal X-ray diffraction. Excitation of the complexes in the ultraviolet region (337 nm) led to near infrared (NIR) luminescence at 1532 nm characteristic of the trivalent erbium ion in the three compounds, with an improved antenna effect in the 5-nitro-1,10-phenanthroline complex. The AC susceptibility studies conducted at frequencies ranging from 33 to 9995 Hz and at temperatures in the 1.7 to 10 K range revealed that the application of a static magnetic field induces a slow magnetic relaxation in all three compounds. The complex with the bulkier capping ligand (bathophenanthroline) exhibits the highest energy barrier U/k(B) = 23 K. PMID:24643638

Ramos Silva, M; Martín-Ramos, P; Coutinho, J T; Pereira, L C J; Martín-Gil, J

2014-05-14

388

Deuterium permeation through erbium oxide coatings on RAFM steels by a dip-coating technique  

NASA Astrophysics Data System (ADS)

A tritium permeation barrier is a promising solution for the problems of tritium loss and radiological safety in fusion blanket systems. In recent years, erbium oxide coatings have shown remarkable permeation reduction factors. One of the remaining issues for the coatings is the establishment of plant-scale fabrication. In this study, erbium oxide thin films have been fabricated by a dip-coating technique, which has the potential to coat a complex-shaped substrate, and deuterium permeation behavior in the coatings has been examined. Crack-free coatings were formed on a reduced activation ferritic/martensitic steel F82H substrate by use of a withdrawal speed of 1.0-1.4 mm s-1 and a heat-treatment process in hydrogen with moisture. In deuterium permeation experiments, a 0.2-?m-thick coating on both sides of the substrate showed a reduction factor of 600-700 in comparison with a F82H substrate below 873 K; however, the coating degraded at above 923 K because of crack formation. A double-coated sample indicated a reduction factor of up to 2000 and did not degrade at up to 923 K. The driving pressure dependence of the deuterium permeation flux indicated that the permeation tended to be limited by surface reactions at low temperatures. Optimization of the number of layers has the possibility to reduce degradation at high temperatures while maintaining high permeation reduction factors.

Chikada, Takumi; Naitoh, Shunya; Suzuki, Akihiro; Terai, Takayuki; Tanaka, Teruya; Muroga, Takeo

2013-11-01

389

Four-Wave-Mixing in Zirconia-Yttria-Aluminum Erbium Codoped Silica Fiber  

NASA Astrophysics Data System (ADS)

The generation and characterization of the Four-Wave-Mixing (FWM) effect in an Erbium Doped Zirconia-Yttria-Alumino Silicate Fiber (EDZF) is described. The EZDF is fabricated from a conventional silica preform by Modified Chemical Vapour Deposition (MCVD) and also solution doping to add glass modifiers and nucleating agents, with the resulting preform annealed and drawn into a fiber strand with a 125 × 0.5 ?m diameter. A 4 m long EZDF with a propagation loss of 0.68 dB/m and an erbium concentration of 3000 ppm is used to investigate the FWM effect. The FWM power levels are measured to be approximately - 45 dBm at a region of 1565 nm and show good agreement with the theoretical predicted values. A non-linear coefficient of 14 W-1km-1 is also measured, along with chromatic and slope dispersion values of 28.45 ps/nm.km and 3.63 ps/nm2.km, which agree with the predicted values. The fabricated EZDF has many potential applications utilizing the FWM effect, including the generation of multi-wavelength outputs.

Ahmad, H.; Paul, M. C.; Awang, N. A.; Harun, S. W.; Pal, M.; Thambiratnam, K.

2012-05-01

390

All fiber passively mode locked zirconium-based erbium-doped fiber laser  

NASA Astrophysics Data System (ADS)

All passively mode locked erbium-doped fiber laser with a zirconium host is demonstrated. The fiber laser utilizes the Non-Linear Polarization Rotation (NPR) technique with an inexpensive fiber-based Polarization Beam Splitter (PBS) as the mode-locking element. A 2 m crystalline Zirconia-Yttria-Alumino-silicate fiber doped with erbium ions (Zr-Y-Al-EDF) acts as the gain medium and generates an Amplified Spontaneous Emission (ASE) spectrum from 1500 nm to 1650 nm. The generated mode-locked pulses have a spectrum ranging from 1548 nm to more than 1605 nm, as well as a 3-dB bandwidth of 12 nm. The mode-locked pulse train has an average output power level of 17 mW with a calculated peak power of 1.24 kW and energy per pulse of approximately 730 pJ. The spectrum also exhibits a Signal-to-Noise Ratio (SNR) of 50 dB as well as a repetition rate of 23.2 MHz. The system is very stable and shows little power fluctuation, in addition to being repeatable.

Ahmad, H.; Awang, N. A.; Paul, M. C.; Pal, M.; Latif, A. A.; Harun, S. W.

2012-04-01

391

Ultra-stable harmonically mode-locked erbium-doped waveguide laser  

NASA Astrophysics Data System (ADS)

Generation of stable pulses and a frequency stabilized optical comb are two key requirements for Fourier Based Arbitrary Waveform Generation (AWG) techniques. The longitudinal mode spacing of the laser must remain as stable as possible to permit effective isolation and processing of the modes for waveform synthesis. The short and long term temporal stability ultimately limits the system's precision as well as its operability in fielded systems. A packaged erbium-doped waveguide provided a highly compact gain medium for the harmonically mode-locked laser design. Stability was achieved by use of an intracavity etalon for frequency stabilization of the optical comb, a Pound-Drever- Hall (PDH) method, and an active bias feedback loop for low frequency noise suppression. The temperature was controlled to limit cavity length variation, and the contribution to stability of each method is quantitatively assessed. The system's stable operating time was increased from hours to greater than a day, and the timing jitter is demonstrated to be lower than that of commercially available erbium-doped fiber laser (EDFL) systems. Applications to optical signal synthesis and Laser Radar are briefly discussed.

Fanto, M. L.; Erdmann, R. K.; Wysocki, B. T.; Malowicki, J. E.; McEwen, T. A.

2007-04-01

392

Synthesis And Luminescence Properties of Erbium-Doped Y(2)O(3) Nanotubes  

SciTech Connect

Erbium-doped yttrium oxide nanotubes (Er{sup 3+}:Y{sub 2}O{sub 3} NTs) with 0-100% doping levels were synthesized by a hydrothermal procedure followed by a dehydration process from Er{sup 3+}:Y(OH){sub 3} NTs. The as-synthesized Er{sup 3+}:Y{sub 2}O{sub 3} nanotubes ranged from 100 to 400 nm in outer diameter and 2 to 5 {micro}m in length with a hexagonal cross section. A time-dependent nanostructure evolution study was performed under hydrothermal conditions, and the effects of other processing parameters, including pH, concentration, and ionic strength of the precursor solution as well as the time span for adding the alkaline solution, were found to dictate the purity and morphology of the as-synthesized Er{sup 3+}:Y(OH){sub 3} nanostructures. A kinetics-controlled dissolution-recrystallization mechanism is proposed to explain the anisotropic growth of these hollow nanotubes from the hexagonal crystal structure of yttrium and erbium hydroxides. Outstanding room-temperature photoluminescence around 1535 nm was demonstrated for these Er{sup 3+}:Y{sub 2}O{sub 3} NTs, making them promising for optical amplifier, laser, and active waveguide applications in telecommunications.

Mao, Y.; Huang, J.Y.; Ostroumov, R.; Wang, K.L.; Chang, J.P.

2009-05-19

393

Gamma-Ray Measurement of 152Eu Produced by Neutrons from the Hiroshima Atomic Bomb and Evaluation of Neutron Fluence  

NASA Astrophysics Data System (ADS)

The 152Eu/Eu ratios were measured in a tombstone exposed to neutrons of the Hiroshima atomic bomb near the hypocenter. Measurements of 152Eu gamma rays were performed for europium samples chemically isolated from numerous rock specimens taken from the tombstone. A reliable attenuation curve of the 152Eu/Eu ratios was obtained. The curve suggests that the thermal neutron component was relatively small and the average incident angle of neutrons to the tombstone was roughly 45° from the perpendicular downward direction. It revealed to us several important pieces of information concerning the energy and angular distributions near the Hiroshima bomb hypocenter.

Kato, Kazuo; Habara, Minoru; Aoyama, Tetsuhisa; Sakata, Hidefumi; Yoshizawa, Yasukazu

1990-08-01

394

Absorption spectra of 4f electron transitions of the neodymium and erbium complexes with benzoyl-indan-1,3-dione and cetyltrimethyl-ammonium bromide and its analytical application  

NASA Astrophysics Data System (ADS)

The absorption spectra of 4f electron transitions of the neodymium and erbium complexes with benzoyl-indan-1,3-dione and cetyltrimethylammonium bromide have been studied by normal and derivative spectrophotometry. The molar absorptivity of 4f electron transitions at the maximum absorption bands are 84.7 for neodymium and 77.3 for erbium. Their derivative molar absorptivity are 627 and 538, respectively. The linear dynamic range extents to 20 ?g cm -3 of neodymium and erbium, and the detection limits (signal to noise ratio=2) are 0.05 and 0.08 ?g cm -3 for neodymium and erbium, respectively. The relative standard deviations evaluated from seven independent determinations of 5.0 ?g cm -3 of neodymium and erbium are 1.2 and 1.0%, respectively. The method has been used for the determination of neodymium and erbium in mixed rare earths with satisfactory results.

Wang, Naixing; Si, Zhikun; Jiang, Wei

1997-06-01

395

77 FR 16949 - Pacific Cod by Catcher Vessels Greater Than or Equal to 50 Feet (15.2 Meters) Length Overall...  

Federal Register 2010, 2011, 2012, 2013

...Vessels Greater Than or Equal to 50 Feet (15.2 Meters) Length Overall Using Hook-and-Line...CVs) greater than or equal to 50 feet (15.2 meters (m)) in length overall (LOA...to CVs greater than or equal to 50 feet (15.2 m) LOA using hook-and-line...

2012-03-23

396

77 FR 13510 - Pacific Cod by Catcher Vessels Less Than 50 Feet (15.2 Meters) Length Overall Using Hook-and-Line...  

Federal Register 2010, 2011, 2012, 2013

...Cod by Catcher Vessels Less Than 50 Feet (15.2 Meters) Length Overall Using Hook-and-Line...catcher vessels (CVs) less than 50 feet (15.2 meters (m)) in length overall (LOA...catch apportioned to CVs less than 50 feet (15.2 m) LOA using hook-and-line...

2012-03-07

397

10 CFR 8.1 - Interpretation of section 152 of the Atomic Energy Act of 1954; opinion of the General Counsel.  

Code of Federal Regulations, 2010 CFR

...Interpretation of section 152 of the Atomic Energy Act of 1954; opinion of the General...Interpretation of section 152 of the Atomic Energy Act of 1954; opinion of the General...provisions of section 152 of the Atomic Energy Act of 1954 (68 Stat....

2010-01-01

398

10 CFR 8.1 - Interpretation of section 152 of the Atomic Energy Act of 1954; opinion of the General Counsel.  

Code of Federal Regulations, 2010 CFR

...Interpretation of section 152 of the Atomic Energy Act of 1954; opinion of the General...Interpretation of section 152 of the Atomic Energy Act of 1954; opinion of the General...provisions of section 152 of the Atomic Energy Act of 1954 (68 Stat....

2009-01-01

399

Simultaneous Measurement of Strain and Temperature by use of a Single-Fiber Bragg Grating and an Erbium-Doped Fiber Amplifier  

Microsoft Academic Search

We propose and demonstrate a novel sensor by using a single-fiber Bragg grating that can simultaneously measure strain and temperature with the aid of an erbium-doped fiber amplifier. By using a linear variation in the amplified spontaneous emission power of the erbium-doped fiber amplifier with temper- ature, we determine the temperature. By subtracting the temperature effect from the fiber Bragg

Jaehoon Jung; Hui Nam; Ju Han Lee; Byoungho Lee

1999-01-01

400

29 CFR 1990.152 - Model emergency temporary standard pursuant to section 6(c) of the Act.  

Code of Federal Regulations, 2010 CFR

...REGULATION OF POTENTIAL OCCUPATIONAL CARCINOGENS Model Standards § 1990.152 Model emergency temporary standard pursuant to section...and procedures are performed by or under the supervision of a licensed physician, and shall be...

2010-07-01

401

29 CFR 1990.152 - Model emergency temporary standard pursuant to section 6(c) of the Act.  

Code of Federal Regulations, 2010 CFR

...REGULATION OF POTENTIAL OCCUPATIONAL CARCINOGENS Model Standards § 1990.152 Model emergency temporary standard pursuant to section...and procedures are performed by or under the supervision of a licensed physician, and shall be...

2009-07-01

402

Production Considerations for Europium-152 Teletherapy Sources Including Design of a Source Capsule with Intrinsic Beam-Hardening Capability  

NASA Astrophysics Data System (ADS)

Production parameters are presented for europium-152 which suggest that teletherapy sources can be manufactured by 60 days of irradiation at modest fluxes; e.g.,6×1013 neutrons·cm-2·s-1. Comparisons with cobalt-60—where irradiations lasting 1 to 3 years at fluxes from 1014 to 1015 neutrons·cm-2·s-1 are standard practice—show that raw-isotope costs for europium-152 are below cobalt-60 by nearly two orders of magnitude. Analysis shows that europium-152, whose limiting specific activity is much less than that of cobalt-60, can yet be contained in quantities which deliver 1 Gy·min-1·m in comparable capsules, and designs are proposed which incorporate depleted uranium filtration. Isotopic purity of europium-152 is likely to be 97.5%—adequate for teletherapy.

Adelman, Stuart

1999-12-01

403

Error analysis for duct leakage tests in ASHRAE standard 152P  

SciTech Connect

This report presents an analysis of random uncertainties in the two methods of testing for duct leakage in Standard 152P of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). The test method is titled Standard Method of Test for Determining Steady-State and Seasonal Efficiency of Residential Thermal Distribution Systems. Equations have been derived for the uncertainties in duct leakage for given levels of uncertainty in the measured quantities used as inputs to the calculations. Tables of allowed errors in each of these independent variables, consistent with fixed criteria of overall allowed error, have been developed.

Andrews, J.W.

1997-06-01

404

Investigation of the thermal conductivity of freon-152A near the saturation curve  

SciTech Connect

An experimental study of the thermal conductivity of liquid F-152A near the saturation curve (two series of experiments - along isobars and isotherms) and of the gaseous freon at atmospheric pressure is described. The measurements were performed by the hot-wire technique using a measuring unit with a 0.4 mm gap. It is established that as the saturation curve is approached over a reduced-temperature range of 0.92 to 0.98, the thermal conductivity becomes a complex function of temperature and pressure.

Geller, V.Z.; I'Yushenko, S.V.; Zaporochan, G.V.

1983-11-01

405

EVN e-VLBI detections of MAXI J1659-152  

NASA Astrophysics Data System (ADS)

We observed MAXI J1659-152 (Negoro et al. 2010, ATel #2873; Mangano et al. 2010, GCN #11296) following its sub-millimeter and centimeter radio detections (de Ugarte Postigo et al. 2010, GCN #11304; van der Horst et al. 2010, ATel #2874) with the European VLBI Network (EVN) in real-time e-VLBI mode on 30 September 2010, from 13:30 to 18:30 UT at 4.9 GHz. The participating telescopes were Cambridge, Effelsberg, Jodrell Bank (MkII), Hartebeesthoek, Medicina, Onsala, Torun and Westerbork sending data at a rate of ~1024 Mbps to the EVN Data Processor at JIVE.

Paragi, Z.; van der Horst, A. J.; Granot, J.; Taylor, G. B.; Kouveliotou, C.; Garrett, M. A.; Wijers, R. A. M. J.; Ramirez-Ruiz, E.; Kuulkers, E.; Gehrels, N.; Woods, P. M.

2010-10-01

406

SWIFT OBSERVATIONS OF MAXI J1659-152: A COMPACT BINARY WITH A BLACK HOLE ACCRETOR  

SciTech Connect

We report on the detection and follow-up high-cadence monitoring observations of MAXI J1659-152, a bright Galactic X-ray binary transient with a likely black hole accretor, by Swift over a 27 day period after its initial outburst detection. MAXI J1659-152 was discovered almost simultaneously by Swift and the Monitor of All-sky X-ray Image on 2010 September 25, and was monitored intensively from the early stages of the outburst through the rise to a brightness of {approx}0.5 Crab by the Swift X-ray, UV/Optical, and the hard X-ray Burst Alert Telescopes. We present temporal and spectral analysis of the Swift observations. The broadband light curves show variability characteristic of black hole candidate transients. We present the evolution of thermal and non-thermal components of the 0.5-150 keV combined X-ray spectra during the outburst. MAXI J1659-152 displays accretion state changes typically associated with black hole binaries, transitioning from its initial detection in the hard state, to the steep power-law state, followed by a slow evolution toward the thermal state, signified by an increasingly dominant thermal component associated with the accretion disk, although this state change did not complete before Swift observations ended. We observe an anti-correlation between the increasing temperature and decreasing radius of the inner edge of the accretion disk, suggesting that the inner edge of the accretion disk infalls toward the black hole as the disk temperature increases. We observed significant evolution in the absorption column during the initial rise of the outburst, with the absorption almost doubling, suggestive of the presence of an evolving wind from the accretion disk. We detect quasi-periodic oscillations that evolve with the outburst, as well as irregular shaped dips that recur with a period of 2.42 {+-} 0.09 hr, strongly suggesting an orbital period that would make MAXI J1659-152 the shortest period black hole binary yet known.

Kennea, J. A. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Romano, P.; Mangano, V. [INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica, Via U. La Malfa 153, I-90146 Palermo (Italy); Beardmore, A. P.; Evans, P. A. [Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom); Curran, P. A. [AIM, CEA/DSM-CNRS, Irfu/SAP, Centre de Saclay, Bat. 709, FR-91191 Gif-sur-Yvette Cedex (France); Krimm, H. A. [Center for Research and Exploration in Space Science and Technology (CRESST), NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Markwardt, C. B. [Astroparticle Physics Laboratory, Mail Code 661, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Yamaoka, K., E-mail: kennea@swift.psu.edu [Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258 (Japan)

2011-07-20

407

Erbium-doped GaAs/AlGaAs quantum wells and normal mode coupling of semiconductor microcavities  

NASA Astrophysics Data System (ADS)

This dissertation investigated two different types of semiconductor heterostructures grown by molecular beam epitaxy. The first were erbium-doped GaAs/AlGaAs quantum well structures with concentrations of Er in the range of 10sp{17}-2×10sp{19}\\ cmsp{-3}. Photoluminescence (PL) of Ersp{3+} ions and Er-induced defects were studied at liquid helium and higher temperatures. A strong diffusion of erbium and interdiffusion of gallium and aluminum ions were observed at the boundary of the GaAs/AlGaAs quantum wells which led, at high erbium concentrations, to the degradation of the quantum wells and macroscopic (average) leveling of the erbium and aluminum concentrations over the whole semiconductor structure. From high-resolution PL spectra the existence of three types of Er centers was deduced that differ by the positions of fine structure lines, PL lifetimes, and PL temperature dependence. Our results indicate that these centers are accompanied by the appearance of three types of carrier traps. Our experiments give evidence that the carriers captured into these traps control the Auger excitation of Er ions. Besides erbium luminescence at 1.54 mum, we have observed luminescence of erbium ions from upper excited states at 0.82 and 0.98 mum which demonstrates the possibility of realizing a three-level scheme of light emission. The second structures investigated were GaAs/AlAs microcavities containing different numbers of identical and non-identical quantum wells. The normal mode coupling behavior of these structures was studied, including the differences from the atomic case. For the identical quantum well structures we examined their linear and nonlinear behavior and modeled this behavior using a transfer matrix method. For the non-identical quantum well case we measured three-dip reflectivity spectra characteristic of three coupled oscillators. A theoretical model based on a nonlocal dielectric response and a transfer matrix method was used to model the microcavities and yielded good agreement with experiment. A simpler model using dispersion theory was also described that gave good qualitative agreement to the measurements.

Lindmark, Eric Karl

408

Optical properties of amorphous, erbium-doped yttrium alumino-borate thin films  

NASA Astrophysics Data System (ADS)

In this paper, we report on the optical characterizations of erbium-doped yttrium alumino-borate glassy thin films prepared by the polymeric precursor and sol-gel routes and the spin-coating technique. High quality planar waveguides were produced by a multilayer processing of Y 1-xEr xAl 3(BO 3) 4 compositions with x = 0.02, 0.05, 0.10, 0.30, and 0.50. Their optical properties were investigated using transmission, photoluminescence, and m-lines spectroscopy, whereas high resolution scanning electron microscopy (HR-SEM) was applied to check film thickness and surface homogeneity. The refractive indices determined from transmission and m-lines spectroscopy are in good agreement just like the film thickness measured by HR-SEM and transmission spectroscopy. We observed low propagation losses, together with efficient photoluminescence emission for polymeric precursor thin films, involving low cost and environment friendly reactants.

Maia, L. J. Q.; Fick, J.; Hernandes, A. C.; Mastelaro, V. R.; Ibanez, A.

2012-02-01

409

Bandwidth-adjustable dynamic grating in erbium-doped fiber by synthesis of optical coherence function.  

PubMed

We present an approach for bandwidth-adjustable optical filter with the dynamic grating in erbium-doped fiber (EDF). The dynamic grating is introduced by the interference of two coherent light beams counter-propagating in the pumped EDF per the phenomenon of gain saturation. The bandwidth of the grating is determined by the length of the grating, i.e., the length of the interference region. With the technique of synthesis of optical coherence function (SOCF), we localize the interference into a range at an arbitrary position along the fiber by modulating the frequency of the two interfering light beams. The length of the range is controlled by adjusting the frequency modulation parameter. In this way, the length of the dynamic grating is controlled and its reflection bandwidth then adjusted. The experimental demonstration is given. PMID:19498578

Fan, Xinyu; He, Zuyuan; Mizuno, Yosuke; Hotate, Kazuo

2005-07-25

410

N-order bright and dark rogue waves in a resonant erbium-doped fiber system  

NASA Astrophysics Data System (ADS)

The rogue waves in a resonant erbium-doped fiber system governed by a coupled system of the nonlinear Schrödinger equation and the Maxwell-Bloch equation (NLS-MB equations) are given explicitly by a Taylor series expansion about the breather solutions of the normalized slowly varying amplitude of the complex field envelope E, polarization p, and population inversion ?. The n-order breather solutions of the three fields are constructed using a Darboux transformation (DT) by assuming periodic seed solutions. Moreover, the n-order rogue waves are given by determinant forms with n+3 free parameters. Furthermore, the possible connection between our rouge waves and the generation of supercontinuum generation is discussed.

He, Jingsong; Xu, Shuwei; Porseizan, K.

2012-12-01

411

Suppression of thermal frequency noise in erbium-doped fiber random lasers.  

PubMed

Frequency and intensity noise are characterized for erbium-doped fiber (EDF) random lasers based on Rayleigh distributed feedback mechanism. We propose a theoretical model for the frequency noise of such random lasers using the property of random phase modulations from multiple scattering points in ultralong fibers. We find that the Rayleigh feedback suppresses the noise at higher frequencies by introducing a Lorentzian envelope over the thermal frequency noise of a long fiber cavity. The theoretical model and measured frequency noise agree quantitatively with two fitting parameters. The random laser exhibits a noise level of 6??Hz²/Hz at 2 kHz, which is lower than what is found in conventional narrow-linewidth EDF fiber lasers and nonplanar ring laser oscillators (NPROs) by a factor of 166 and 2, respectively. The frequency noise has a minimum value for an optimum length of the Rayleigh scattering fiber. PMID:24562272

Saxena, Bhavaye; Bao, Xiaoyi; Chen, Liang

2014-02-15

412

N-order bright and dark rogue waves in a resonant erbium-doped fiber system.  

PubMed

The rogue waves in a resonant erbium-doped fiber system governed by a coupled system of the nonlinear Schrödinger equation and the Maxwell-Bloch equation (NLS-MB equations) are given explicitly by a Taylor series expansion about the breather solutions of the normalized slowly varying amplitude of the complex field envelope E, polarization p, and population inversion ?. The n-order breather solutions of the three fields are constructed using a Darboux transformation (DT) by assuming periodic seed solutions. Moreover, the n-order rogue waves are given by determinant forms with n+3 free parameters. Furthermore, the possible connection between our rouge waves and the generation of supercontinuum generation is discussed. PMID:23368068

He, Jingsong; Xu, Shuwei; Porsezian, K; Porseizan, K

2012-12-01

413

Stability of short, single-mode erbium-doped fiber lasers  

SciTech Connect

We conducted a detailed study of the stability of short, erbium-doped fiber lasers fabricated with two UV-induced Bragg gratings written into the doped fiber. We find that the relative intensity noise of single-longitudinal-mode fiber grating lasers is approximately 3 orders of magnitude lower than that of a single-frequency 1.523-{mu}m helium-neon laser. The frequency noise spectrum contains few resonances, none of which exceeds 0.6 kHz/Hz{sup 1/2} rms; the integrated rms frequency noise from 50 Hz to 63 kHz is 36 kHz. We also demonstrate a simple method for monitoring the laser power and number of oscillating modes during laser fabrication. {copyright} 1997 Optical Society of America

Svalgaard, M.; Gilbert, S.L. [National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80303 (United States)

1997-07-01

414

Broadly tunable multiwavelength Brillouin-erbium fiber laser using a twin-core fiber coupler  

NASA Astrophysics Data System (ADS)

A tunable multiwavelength Brillouin-erbium fiber laser (MW-BEFL) using a twin-core fiber (TCF) coupler is proposed and demonstrated. The TCF coupler is formed by splicing a section of TCF between two single-mode fibers. By simply applying bending curvature on the TCF coupler, the peak net gain is shifted close to the Brillouin pump (BP), which has advantage for suppressing self-lasing cavity modes with low-BP-power injection. In this work, the dependency of the Stokes signals tuning range on the free spectral range (FSR) of TCF coupler is studied. It is also found that the tuning range of MW-BEFL can exceed the FSR of TCF coupler by adopting proper BP power and 980-nm pump power. Up to 40 nm tuning range of MW-BEFL in the absence of self-lasing cavity modes is achieved.

Peng, Wanjing; Yan, Fengping; Li, Qi; Liu, Shuo; Tan, Siyu; Feng, Suchun; Feng, Ting

2014-07-01

415

Self-Q-switching behavior of erbium-doped tellurite microstructured fiber lasers  

NASA Astrophysics Data System (ADS)

We reported self-Q-switching behavior of erbium-doped tellurite microstructured fiber (EDTMF) lasers and further demonstrated a self-Q-switched EDTMF laser with a high repetition rate of more than 1 MHz. A 14 cm EDTMF was used as the gain medium. Upon a pump power of ˜705 mW at 1480 nm, output pulses with a lasing wavelength of ˜1558 nm, a repetition rate of ˜1.14 MHz, and a pulse width of ˜282 ns were generated from the fiber by employing a linear cavity. The maximum output power was ˜316 mW and the slope efficiency was about 72.6% before the saturation of the laser power. Moreover, the influence of the fiber length on laser performances was investigated. The results showed that self-Q-switching behavior in our experiments was caused by the re-absorption originated from the ineffectively pumped part of the active fiber.

Jia, Zhi-Xu; Yao, Chuan-Fei; Kang, Zhe; Qin, Guan-Shi; Ohishi, Yasutake; Qin, Wei-Ping

2014-06-01

416

Magnetic and structural phase transitions in erbium at low temperatures and high pressures  

SciTech Connect

Electrical resistance and crystal structure measurements have been carried out on polycrystalline erbium (Er) at temperatures down to 10 K and pressures up to 20 GPa. An abrupt change in the slope of the resistance is observed with decreasing temperature below 84 K, which is associated with the c-axis modulated (CAM) antiferromagnetic (AFM) ordering of the Er moments. With increasing pressure the temperature of the resistance slope change and the corresponding AFM ordering temperature decrease until vanishing above 10.6 GPa. The disappearance of the slope change in the resistance occurs at similar pressures where the hcp structural phase of Er is transformed to a nine-layer {alpha}-Sm structural phase, as confirmed by our high-pressure synchrotron x-ray diffraction studies. These results suggest that the disappearance in the AFM ordering of Er moments is strongly correlated to the structural phase transition at high pressures and low temperatures.

Thomas, Sarah A.; Tsoi, Georgiy M.; Wenger, Lowell E.; Vohra, Yogesh K. (UAB)

2012-02-07

417

Multiphoton microscopy using frequency-doubled compact femtosecond erbium-doped fiber laser  

NASA Astrophysics Data System (ADS)

We report on the development of a compact multiphoton microscopy (MPM) system based on a frequency-doubled, femtosecond erbium-doped fiber laser source at 1.58 ?m. By use of periodically poled MgO:LiNbO3, frequency-doubled pulses at 790 nm with average power of 75 mW and pulse width of 130 fs are applied as the excitation source. The fiber laser is optimized for its parameters along with the dispersive properties of the delivery fiber such that the MPM signal is maximized at the sample location. Micro-electro-mechanical system (MEMS) scanner, miniature objective, and multimode fiber are further used to make the MPM system compact. MPM images are obtained from unstained biological samples. The MPM system with a compact, portable, low-cost fiber laser has a great potential to transform the bench-top MPM system to a portable system for in vivo MPM imaging.

Huang, Lin; Chong, Shau Poh; Mills, Arthur; Jones, David; Tang, Shuo

2014-02-01

418

In vitro evaluation of erbium, chromium:yttrium–scandium–gallium–garnet laser-treated enamel demineralization  

Microsoft Academic Search

This study evaluated the effect of different parameters of erbium, chromium:yttrium–scandium–gallium–garnet (Er,Cr:YSGG) laser\\u000a irradiation on enamel mineral loss in a simulated caries model. Forty-five enamel samples obtained from third molar teeth\\u000a (3 mm×?3 mm) were randomly divided into five groups (n?=?9): G1—Er,Cr:YSGG laser at 0.25 W, 20 Hz, 2.8 J\\/cm2; G2—Er,Cr:YSGG laser at 0.50 W, 20 Hz, 5.7 J\\/cm2; G3—Er,Cr:YSGG laser at 0.75 W, 20 Hz, 8.5 J\\/cm2; G4—sodium fluoride (NaF)

Patrícia M. de Freitas; Marcia Rapozo-Hilo; Carlos de P. Eduardo; John D. B Featherstone

2010-01-01

419

Broadly tunable multiwavelength Brillouin-erbium fiber laser using a twin-core fiber coupler  

NASA Astrophysics Data System (ADS)

A tunable multiwavelength Brillouin-erbium fiber laser (MW-BEFL) using a twin-core fiber (TCF) coupler is proposed and demonstrated. The TCF coupler is formed by splicing a section of TCF between two single-mode fibers. By simply applying bending curvature on the TCF coupler, the peak net gain is shifted close to the Brillouin pump (BP), which has advantage for suppressing self-lasing cavity modes with low-BP-power injection. In this work, the dependency of the Stokes signals tuning range on the free spectral range (FSR) of TCF coupler is studied. It is also found that the tuning range of MW-BEFL can exceed the FSR of TCF coupler by adopting proper BP power and 980-nm pump power. Up to 40 nm tuning range of MW-BEFL in the absence of self-lasing cavity modes is achieved.

Peng, Wanjing; Yan, Fengping; Li, Qi; Liu, Shuo; Tan, Siyu; Feng, Suchun; Feng, Ting

2013-09-01

420

High energy in-band pumped erbium doped pulse fibre laser  

NASA Astrophysics Data System (ADS)

We demonstrate an inband, core-pumped master oscillator power amplifier (MOPA) with a maximum pulse energy of 1.56 mJ at a repetition rate of 1.25 kHz, seeded by an actively Q-switched Erbium/Ytterbium-codoped fiber (EYDF) ring laser, producing 150-ns pulses at 1562.5 nm. To maximize energy extraction whilst minimizing signal saturation effects, a 40?m Er3+-doped larger mode area (LMA) fiber was used as the gain medium. A 1535 nm single mode fiber laser was used for in-band pumping of the LMA fiber. The output beam quality (M2) was measured to be ~1.6. This is to the best of our knowledge is the highest reported pulse energy for a pulse fiber laser at 1.5 ?m with M2~1.6.

Lim, E. L.; Alam, S. U.; Richardson, D. J.

2012-02-01

421

Raman scattering in semiconductor structures based on monophthalocyanine and triphthalocyanine molecules incorporating erbium ions  

SciTech Connect

Semiconductor structures of the type of butyl-substituted erbium monophthalocyanine and triphthalocyanine are studied by Raman spectroscopy. It is shown that, when the sandwich-like structure of the molecule incorporating two complexing atoms between the ligands is considered instead of the planar molecular structure with one ligand and one metal atom, a series of lines appears in the Raman spectrum. In this series, the wave numbers of the lines represent an arithmetic progression with the arithmetical ratio {approx}80 cm{sup -1}. It is suggested that this feature is due to the larger number of organic molecules per metal atom in the triphthalocyanine complex, and the four Raman peaks at the frequencies 122, 208, 280, and 362 cm{sup -1} are the manifestation of slight out-of-plane vibrations of the phthalocyanine ligands.

Belogorokhov, I. A., E-mail: jugqwerty@mail.ru; Tikhonov, E. V.; Breusova, M. O.; Pushkarev, V. E.; Zoteev, A. V.; Tomilova, L. G.; Khokhlov, D. R. [Moscow State University (Russian Federation)

2007-11-15

422

Magnetic behavior of erbium-zinc-borate glasses and glass ceramics  

NASA Astrophysics Data System (ADS)

Glasses of the system (ErO)?(BO)?(ZnO) (3 ? x ? 15 mol%) were prepared by conventional melt quenching and subsequently converted to glass ceramics by heat treatment of glass samples at 860 °C for 2 h. The magnetic behaviour of the studied glasses and glass ceramics were investigated using a vibrating sample magnetometer (VSM) and a Faraday-type magnetic balance. Magnetic data show that erbium ions are involved in negative superexchange interactions in all the investigated samples, being antiferromagnetically coupled. For all studied samples the experimental values obtained for the effective magnetic moments are lower than the value corresponding to free Er ions and decrease with the increasing of ErO content. The decrease is more pronounced in heat treated samples than untreated ones.

Borodi, G.; Pascuta, P.; Bosca, M.; Stefan, R.; Tetean, R.; Pop, V.; Radulescu, D.

2013-11-01

423

Submicrojoule femtosecond erbium-doped fibre laser for the generation of dispersive waves at submicron wavelengths  

NASA Astrophysics Data System (ADS)

We have demonstrated a femtosecond erbium-doped fibre laser system built in the master oscillator/power amplifier (MOPA) approach. The final amplifier stage utilises a specially designed large mode area active fibre cladding-pumped by multimode laser diodes. The system is capable of generating submicrojoule pulses at a wavelength near 1.6 ?m. We have obtained 530-fs pulses with an energy of 400 nJ. The output of the system can be converted to wavelengths shorter than 1 ?m through the generation of dispersive waves in passive nonlinear fibre. We have obtained ultra-short 7-nJ pulses with a spectral width of ~100 nm and a centre wavelength of 0.9 ?m, which can be used as a seed signal in parametric amplifiers in designing petawatt laser systems.

Kotov, L. V.; Koptev, M. Yu; Anashkina, E. A.; Muravyev, S. V.; Andrianov, A. V.; Bubnov, M. M.; Ignat'ev, A. D.; Lipatov, D. S.; Gur'yanov, A. N.; Likhachev, M. E.; Kim, A. V.

2014-05-01

424

Stabilized 51-wavelength erbium-doped fiber ring laser based on high nonlinear fiber  

NASA Astrophysics Data System (ADS)

A multi-wavelength fiber laser source is demonstrated with a high power erbium-doped fiber amplifier as the gain medium. In order to alleviate the mode competition, a highly nonlinear fiber (HNLF) is inserted in the ring cavity to provide nonlinear effects. A fiber Fabry-Perot filter (FFPF) is incorporated in the ring cavity serving as a comb filter. The comparison between HNLF with different length is discussed. Fifty one simultaneous lasing wavelengths within 3 dB uniformity are observed with channel spacing of 25 GHz and a signal to noise ratio of ~48 dB. Moreover, these stable multi-carriers light source is a promising candidate for high capacity optical communication system, such as coherent dense-wavelength-multiplexing (DWDM) in our project.

Yang, Chengliang; Xia, Li; Wang, Yuanwu; Liu, Deming

2014-05-01

425

Erbium-ytterbium doped fiber amplifier with suppressed Yb-ASE and improved efficiency  

NASA Astrophysics Data System (ADS)

A new design of an erbium-ytterbium doped fiber amplifier is demonstrated. The amplifier contains a wavelength-tuned loop resonator for the 1 ?m signal. The amplified spontaneous emission (ASE) from Yb ions is used to stimulate a laser emission at several wavelengths from the 1 ?m band in the 1550 nm amplifier. The wavelength of this lasing is selected by introducing a spectral filter. The results show, that the efficiency of the amplifier at nominal 1550 nm wavelength can be increased by introducing a feedback loop with 1040 nm and 1050 nm filters. This loop also protects the Er-Yb amplifier from parasitic lasing and allows output power scaling without risk of self-pulsing at 1 ?m.

Sobon, Grzegorz; Sliwinska, Dorota; Kaczmarek, Pawel; Abramski, Krzysztof M.

2013-01-01

426

Highly stable graphene-assisted tunable dual-wavelength erbium-doped fiber laser.  

PubMed

A highly stable tunable dual-wavelength fiber laser (TDWFL) using graphene as a means to generate a highly stable output is proposed and generated. The TDWFL comprises a 1 m long, highly doped erbium-doped fiber (EDF) acting as the linear gain medium, with a 24-channel arrayed waveguide grating acting as a wavelength slicer as well as a tuning mechanism to generate different wavelength pairs. The tuned wavelength pairs can range from 0.8 to 18.2 nm. A few layers of graphene are incorporated into the laser cavity to induce the four-wave-mixing effect, which stabilizes the dual-wavelength output by suppressing the mode competition that arises as a result of homogenous broadening in the EDF. PMID:23385923

Ahmad, Harith; Latif, Amirah Abdul; Abdul Khudus, Muhammad Imran Mustafa; Zulkifli, Ahmad Zarif; Zulkifli, Mohd Zamani; Thambiratnam, Kavintheran; Harun, Sulaiman Wadi

2013-02-01

427

Passively mode-locked erbium doped zirconia fiber laser using a nonlinear polarisation rotation technique  

NASA Astrophysics Data System (ADS)

A nonlinear polarization rotation (NPR) based mode-locked fiber laser is demonstrated using a 2 m long erbium-doped Zirconia-Yttria-Allumino Silicate fiber (EDZF) as the gain medium. The EDZF is drawn from a silica preform fabricated using the Modified Chemical Vapor Deposition (MCVD) method in which glass modifiers and nucleating agents are added using the solution doping technique. The fabricated EDZF has a core with dopant concentrations of 0.25 mol% of Al2O3, 2.10 mol% of ZrO2 and 0.23 mol% of Er2O3, peak absorption of 22.0 dB/m at 978 nm and the fluorescence life-time of 10.86 ms. A stable picosecond laser is succesfully obtained with pulse width of 0.32 ps and the repetition rate of 50 MHz using a simple ring cavity.

Hamzah, A.; Paul, M. C.; Awang, N. A.; Ahmad, H.; Pal, M.; Das, S.; Ismail, M. A.; Harun, S. W.

2013-04-01

428

Stable double spacing multiwavelength Brillouin-Erbium doped fiber laser based on highly nonlinear fiber  

NASA Astrophysics Data System (ADS)

A double frequency spaced multiwavelength Brillouin-Erbium doped fiber laser (BEDFL) with figure-of-eight cavity have been successfully developed and tested. Double frequency spacing is achieved by using a piece of 2 km of highly nonlinear fiber (HNLF) as a gain medium. Figure-of-eight configuration removes the odd order Stokes signals via a four-port circulator. Fifteen Stokes channels are simultaneously generated with a spacing of 0.154 nm that is around 20 GHz, when the Brillouin pump and 980 nm pump powers are fixed at the optimized values of 6 dBm and 40 mW, respectively. Fourteen anti stoke channels are also obtained, which are generated through four wave mixing (FWM) process in the laser cavity. The output is smooth triangular comb. The BEFL can also be tuned from 1526.5 to 1567.5 nm.

Ahmad, B. A.; Al-Alimi, A. W.; Abas, A. F.; Harun, S. W.; Mahdi, M. A.

2012-05-01

429

Theoretical and artificial neural network modeling for the output power of irradiated erbium doped fiber amplifier  

NASA Astrophysics Data System (ADS)

The out power of the erbium doped fiber amplifiers (EDFAs) irradiated by neutrons with a dose of 1000 krad, it is investigated by theoretical and artificial neural network (ANN) modeling. Levenberg-Marquardt algorithm has been used for the ANN modeling. The theoretical as well as ANN models are in good agreement with the experimental data. A minimum acceptable error of 1.4×10-4 has been obtained. The theoretical and the ANN models help us to understand the output of EDFAs in detail. The EDF could be used only in the low radiation dose less than 20 krad. The ANN model provide a powerful tool to study the output power of EDFAs.

Hamdalla, Taymour A.

2013-07-01

430

Vacuum sublimation of the reaction products of neodymium dipivaloylmethanate and erbium dipivaloylmethanate with pivalic acid  

SciTech Connect

The processes taking place during the vacuum sublimation of solid complexes of individual rare-earth elements obtained in the M(dpm){sub 3}-nHpiv=hexane systems (M = Nd, Er; Hdpm = dipivaloylmethane; Hpiv = pivalic acid; n = 1, 2, 3) have been studied. It has been noted that the mixed-ligand complexes Er(dpm){sub 3}{center_dot}Hpiv and Nd(dpm){sub 2}piv form in the systems studied when n = 1 and that they disproportionate at different temperatures during heating in a vacuum. It has been discovered that the disproportionation processes of these complexes can be utilized to increase the efficiency of sublimation methods for separating mixtures of neodymium dipivaloylmethanate and erbium dipivaloylmethanate.

An Tu, Z.; Kuz`mina, N.P.; Martynenko, L.I. [M.V. Lomonosov Moscow State Univ. (Russian Federation)

1994-05-01

431

Corneal photoablation in vivo with the erbium:YAG laser: first report  

NASA Astrophysics Data System (ADS)

As an alternative to far-UV lasers for corneal refractive surgery, the Erbium:YAG laser may be used in TEM00 mode. The resulting gaussian beam profile leads to a certain amount of myopic correction per laser pulse. Although animal data suggest that the clinical outcome should be comparable to the UV-lasers, no human data were available until now. We performed Erbium:YAG laser areal ablation in 5 blind human eyes. In TEM00 mode, the laser parameters were: effective diameter of laser spot equals 3.4 mm, fluence equals 380 mJ/cm2, pulse duration equals 250 microsecond(s) , Repetition rate equals 4 Hz, Number of applied laser pulses equals 15. Four patients with no light perception, one with intact light projection on one eye (some of them scheduled for enucleation) were treated under topical anaesthesia. Patient selection and informed consent were agreed to by the University's independent Ethics Committee. Prior to laser irradiation, corneal epithelium was removed. A postoperative silicone cast of the cornea was analyzed with a confocal laser micro-topometer for the ablation profile. The eyes were treated with antibiotic ointment until the epithelium was closed. Clinical appearance and, where possible, profilometry of the ablated area was observed. The ablation profile in cornea was gaussian shaped with a maximal depth of 30 micrometers . During laser treatment, the corneal surface becomes opaque, clearing in a matter of seconds. Epithelial healing and clinical appearance was similar to excimer laser treatment. However, during the first week, the irradiated area shows subepithelial irregularities, resembling small bubbles, disappearing thereafter.

Jean, Benedikt J.; Bende, Thomas; Matallana, Michael; Kriegerowski, Martin

1995-05-01

432

Measurements of erbium laser-ablation efficiency in hard dental tissues under different water cooling conditions.  

PubMed

Laser triangulation measurements of Er:YAG and Er,Cr:YSGG laser-ablated volumes in hard dental tissues are made, in order to verify the possible existence of a "hydrokinetic" effect that has been proposed as an alternative to the "subsurface water expansion" mechanism for hard-tissue laser ablation. No evidence of the hydrokinetic effect could be observed under a broad range of tested laser parameters and water cooling conditions. On the contrary, the application of water spray during laser exposure of hard dental material is observed to diminish the laser-ablation efficiency (AE) in comparison with laser exposure under the absence of water spray. Our findings are in agreement with the generally accepted principle of action for erbium laser ablation, which is based on fast subsurface expansion of laser-heated water trapped within the interstitial structure of hard dental tissues. Our measurements also show that the well-known phenomenon of ablation stalling, during a series of consecutive laser pulses, can primarily be attributed to the blocking of laser light by the loosely bound and recondensed desiccated minerals that collect on the tooth surface during and following laser ablation. In addition to the prevention of tooth bulk temperature buildup, a positive function of the water spray that is typically used with erbium dental lasers is to rehydrate these minerals, and thus sustaining the subsurface expansion ablation process. A negative side effect of using a continuous water spray is that the AE gets reduced due to the laser light being partially absorbed in the water-spray particles above the tooth and in the collected water pool on the tooth surface. Finally, no evidence of the influence of the water absorption shift on the hypothesized increase in the AE of the Er,Cr:YSGG wavelength is observed. PMID:24105399

Kuš?er, Lovro; Diaci, Janez

2013-01-01

433

Experimental and Theoretical Studies of a Harmonically Modelocked Erbium Fiber Ring Laser.  

NASA Astrophysics Data System (ADS)

This thesis presents a comprehensive experimental characterization and a theoretical analysis of a harmonically modelocked erbium fiber laser that is compatible with the current and future demands of high speed data communication and signal processing systems. This laser generates a train of coherent, transform limited Gaussian pulses with pulsewidths in the range of 18-50 ps at a 5 Gb/s repetition rate and 10 ps at a 10 Gb/s repetition rate. The lasing wavelength is continuously tunable from 1532 to 1564 nm. The basic structure of the laser is a 16.8 meter ring of optical fiber in which the light travels in one direction. The gain medium is a 5 meter section of erbium doped fiber. In each round trip, the light also passes through two frequency filters and an amplitude modulator. A broadband Fabry-Perot filter sets the wavelength and a narrowband Fabry-Perot filter prevents unwanted cavity modes from lasing. The modulator couples energy between the selected modes and locks these modes in phase. The steady state output of this laser is a set of well defined frequency modes corresponding to a train of transform limited picosecond pulses. A drawback of fiber lasers is their sensitivity to small temperature fluctuations, so that they must be actively stabilized. Our novel stabilization technique utilizes a narrowband Fabry-Perot filter with a feedback phase locking circuit to track the variation of cavity modes. In addition to the experimental demonstration, a theoretical analysis has been completed. Out analytical theory extends Siegman and Kuizenga's standard modelocking theory to include the effects of birefringence, modulation frequency detuning, cavity length offset, and the effects associated with the presence of Fabry-Perot filters. We also present numerical simulations that confirm the analytical theory and include the effects of third order dispersion and laser build-up noise. These theoretical results can be used to help design of similar modelocked fiber lasers with a wide range of operating parameters.

Wey, Jun Shan

434

{sup 152}Eu depths profiles granite and concrete cores exposed to the Hiroshima atomic bomb  

SciTech Connect

Two granite and two concrete core samples were obtained within 500 m from the hypocenter of the Hiroshima atomic bomb, and the depth profile of {sup 152}Eu was measured to evaluate the incident neutron spectrum. The granite cores were obtained from a pillar of the Motoyasu Bridge located 101 m from the hypocenter and from a granite rock in the Shirakami Shrine (379 m); the concrete cores were obtained from a gate in the Gokoku Shrine (398 m) and from top of the Hiroshima bank (250 m). The profiles of the specific activities of the cores were measured to a depth of 40 cm from the surface using low background germanium (Ge) spectrometers. According to the measured depth profiles, relaxation lengths of incident neutrons were derived as 13.6 cm for Motoyasu Bridge pillar (granite), 12.2 cm for Shirakami Shrine core (granite), and 9.6 cm for concrete cores of Gokoku Shrine and Hiroshima Bank. In addition, a comparison of the granite cores in Hiroshima showed good agreement with Nagasaki data. Present results indicates that the depth profile of {sup 152}Eu reflects incident neutrons not so high but in the epithermal region. 19 refs., 7 figs., 8 tabs.

Shizuma, Kiyoshi; Iwatani, Kazuo [Hiroshima Univ. (Japan); Oka, Takamitsu [Kure Univ. (Japan)] [and others

1997-06-01

435

Population of hyperdeformed structures in {sup 152}Dy from proton-gamma coincidence experiments  

SciTech Connect

The ridge structure with {Delta}{ital E}{sub {gamma}}={plus_minus}30 keV, recently observed in the reaction 187 MeV {sup 37}Cl+{sup 120}Sn and attributed to a hyperdeformed nuclear shape, has been confirmed in a new proton-{gamma} coincidence experiment and assigned to the {sup 152}Dy nucleus. Estimates of the cross section for the population of the 30 keV ridge and for the associated entry states have been obtained. The proton spectra in coincidence with {gamma} rays of different Dy isotopes show effects related to the exit channel and to the angular momentum but they are scarcely sensitive to the selection of different shapes (oblate, normal deformed prolate, superdeformed) in the same residual nucleus {sup 152}Dy. The energy of the protons in coincidence with the {Delta}{ital E}{sub {gamma}}={plus_minus}30 keV ridge is however larger than expected. This effect is discussed in the framework of the fission-evaporation competition.

Viesti, G.; Lunardon, M.; Bazzacco, D.; Burch, R.; Fabris, D.; Lunardi, S.; Medina, N.H.; Nebbia, G.; Rossi-Alvarez, C. [INFN and Dipartimento di Fisica dell`Universita di Padova, I-35131 Padova (Italy)] [INFN and Dipartimento di Fisica dell`Universita di Padova, I-35131 Padova (Italy); de Angelis, G.; De Poli, M.; Fioretto, E.; Prete, G.; Rico, J.; Spolaore, P.; Vedovato, G. [INFN Laboratori Nazionali di Legnaro I-35020 Legnaro, Padova (Italy)] [INFN Laboratori Nazionali di Legnaro I-35020 Legnaro, Padova (Italy); Brondi, A.; La Rana, G.; Moro, R.; Vardaci, E. [INFN and Dipartimento di Fisica dell`Universita di Napoli, I-80125 Napoli (Italy)] [INFN and Dipartimento di Fisica dell`Universita di Napoli, I-80125 Napoli (Italy)

1995-05-01

436

Fusion of 6Li with 152Sm: Role of projectile breakup versus target deformation  

NASA Astrophysics Data System (ADS)

Complete fusion cross sections for 6Li + 152Sm reaction have been measured at beam energies ( E=20-40 MeV) near the Coulomb barrier. The sub-barrier fusion cross sections were found to be systematically larger than those for 6Li + 144Sm, as expected from the deformed shape of the 152Sm nucleus. The coupled-channels (CC) calculations including both projectile and target couplings overpredict the experimental fusion cross sections at above barrier energies. Reduced fusion cross sections for the present system at above barrier energies are found to be smaller compared to those with tightly-bound projectiles forming similar compound nuclei and also to those predicted using proximity potential. These observations along with the comparison of derived barrier distributions conclude that the complete fusion cross sections at energies above the Coulomb barrier are suppressed by 28±4%. A large cross section measured for incomplete fusion indicates that the above suppression is due to the loss of incident flux caused by projectile breakup. Thus the effect of both target deformation and projectile breakup are found to coexist.

Rath, P. K.; Santra, S.; Singh, N. L.; Mahata, K.; Palit, R.; Nayak, B. K.; Ramachandran, K.; Parkar, V. V.; Tripathi, R.; Pandit, S. K.; Appannababu, S.; Deshmukh, N. N.; Choudhury, R. K.; Kailas, S.

2012-01-01

437

Calcium malate overproduction by Penicillium viticola 152 using the medium containing corn steep liquor.  

PubMed

In this study, after screening of eight fungal strains for their ability to produce calcium malate, it was found that Penicillium viticola 152 isolated from marine algae among them could produce the highest titer of calcium malate. At the same time, it was found that corn steep liquor (CSL) could stimulate calcium malate production and 0.5 % (v/v) CSL was the most suitable for calcium malate production. Under the optimal conditions, a titer of calcium malate in the supernatant was 132 g/l at flask level. During a 10-l fermentation, a titer of 168 g/l, a yield of 1.28 g/g of glucose, and a productivity of 1.75 g/l/h were reached within 96 h of the fermentation, and 93.4 % of the sugar was used for calcium malate production and cell growth, demonstrating that the titer, yield, and productivity of calcium malate by this fungal strain were very high and the fermentation period was very short. After analysis of the partially purified product with high-performance liquid chromatography, it was found that the main product was calcium malate. The results demonstrated that P. viticola 152 obtained in this study was the most suitable for developing a novel one-step fermentation process for calcium malate production from glucose on a large scale. PMID:24232832

Khan, Ibrar; Nazir, Kiran; Wang, Zhi-Peng; Liu, Guang-Lei; Chi, Zhen-Ming

2014-02-01

438

Core-pumped gain-guided index-antiguided continuous wave lasing in dispersion-engineered erbium-doped fiber.  

PubMed

We demonstrate core-pumped gain-guided index-antiguided fiber lasers using a 22 cm long dispersion-engineered erbium-doped fiber. The erbium-doped fiber is dispersion-engineered using optical liquid to replace the most part of silica cladding so that the index of core turns out to be higher (lower) than that of new cladding at pump (lasing) wavelength, respectively. The pump light is confined to propagate in core based on an index-guiding mechanism to efficiently excite the gain medium running through the fiber whereas the cw lasing is constructed in a long, small-core waveguide under a gain-guided, index-antiguided situation. PMID:22859084

Chen, Nan-Kuang; Jian, Lian-Jiun

2012-08-01

439

Reduced erbium-doped ceria nanoparticles: one nano-host applicable for simultaneous optical down- and up-conversions  

PubMed Central

This paper introduces a new synthesis procedure to form erbium-doped ceria nanoparticles (EDC NPs) that can act as an optical medium for both up-conversion and down-conversion in the same time. This synthesis process results qualitatively in a high concentration of Ce3+ ions required to obtain high fluorescence efficiency in the down-conversion process. Simultaneously, the synthesized nanoparticles contain the molecular energy levels of erbium that are required for up-conversion. Therefore, the synthesized EDC NPs can emit visible light when excited with either UV or IR photons. This opens new opportunities for applications where emission of light via both up- and down-conversions from a single nanomaterial is desired such as solar cells and bio-imaging.

2014-01-01

440

Supercontinuum generation using a passive mode-locked stretched-pulse bismuth-based erbium-doped fiber laser  

NASA Astrophysics Data System (ADS)

A Supercontinuum (SC) generation in photonic crystal fiber (PCF) is demonstrated using an amplified picosecond stretched-pulses from a passive mode-locked Bismuth-based Erbium-doped fiber laser (Bi-EDFL). The Bi-EDFL employs of a piece of a highly nonlinear 49 cm long Bismuth-based Erbium-doped fiber (Bi-EDF), an optical isolator and a polarization controller in a cavity to generate a mode-locked stretched-pulse via a nonlinear polarization rotation technique. It operates at 1560 nm with a repetition rate of 42 MHz and a pulse width of 131 fs. The SC lights, which extends from 1250 nm to 1910 nm as well as in the visible green wavelength region are obtained with a 100 m long PCF and the amplified pump power of 30 dBm.

Shahabuddin, N. S.; Awang, N. A.; Ahmad, H.; Arof, H.; Dimyati, K.; Yusoff, Z.; Harun, S. W.

2012-06-01

441

Radiation-hard erbium optical fiber and fiber amplifier for both low- and high-dose space missions.  

PubMed

We present a new structure for erbium-doped optical fibers [hole-assisted carbon-coated, (HACC)] that, combined with an appropriate choice of codopants in the core, strongly enhances their radiation tolerance. We built an erbium-doped fiber amplifier based on this HACC fiber and characterize its degradation under ?-ray doses up to 315 krad (SiO2) in the ON mode. The 31 dB amplifier is practically radiation insensitive, with a gain change of merely -2.2×10(-3) dB/krad. These performances authorize the use of HACC doped fibers and amplifiers for various applications in environments associated with today's missions (of doses up to 50 krad) and even for future space missions associated with higher dose constraints. PMID:24784040

Girard, S; Laurent, A; Pinsard, E; Robin, T; Cadier, B; Boutillier, M; Marcandella, C; Boukenter, A; Ouerdane, Y

2014-05-01

442

Coprecipitation of heavy metals with erbium hydroxide for their flame atomic absorption spectrometric determinations in environmental samples.  

PubMed

Trace amounts of copper, manganese, cobalt, chromium, iron and lead were quantitatively coprecipitated with erbium hydroxide on 0.05M NaOH medium. The coprecipitant could be easily dissolved with 1M nitric acid. The presence of up to 15g/l of erbium ions did not interfere with the atomic absorption spectrometric determination of analyte ions. The recovery values for analyte ions were higher than 95%. The concentration factor was 25-fold. Coprecipitation parameters including reagent amounts and matrix effects are discussed. The relative standard deviations of the determinations were below 9%. The time required for the coprecipitation was about 30min. The proposed method was successfully applied for the determination of trace amounts of analyte ions in urine, soil and sediment, natural water samples. PMID:18970095

Soylak, Mustafa; Saracoglu, Sibel; Divrikli, Umit; Elci, Latif

2005-06-15

443

Influence of Roughness Surfaces on Third-Order Nonlinear-Optical Properties of Erbium-Doped Zinc Oxide Thin Films  

Microsoft Academic Search

Zinc oxide (ZnO) and erbium-doped zinc oxide (ZnO:Er) thin films were deposited on heated glass substrates using the spray pyrolysis technique. Third-order nonlinear-optical properties of the thin films have been investigated using the third harmonic generation (THG) at wavelength of 1064 nm in picosecond regime. The dependence of third-order nonlinear susceptibility and transmission characteristics on the thin films roughness has been

M. Alaoui Lamrani; M. El Jouad; M. Addou; T. El Habbani; N. Fellahi; K. Bahedi; M. Ebn Touhami; Z. Essaidi; Z. Sofiani; B. Sahraoui; A. Meghea; I. Rau

2008-01-01

444

Period-doubling of dispersion-managed solitons in an Erbium-doped fiber laser at around zero dispersion  

Microsoft Academic Search

Period-doubling of dispersion-managed solitons in an Erbium-doped fiber ring laser operating at the near zero net cavity group velocity dispersion region was experimentally observed. The generated dispersion-managed solitons of the laser are characterized by their near Gaussian spectral profiles and no sidebands. Numerical simulations verified our experimental observations and showed that the period-doubling could occur both in the positive and

L. M. Zhao; D. Y. Tang; T. H. Cheng; H. Y. Tam; C. Lu; S. C. Wen

2007-01-01

445

Gain tilt control of L-band erbium-doped fiber amplifier by using a 1550-nm band light injection  

Microsoft Academic Search

In this letter, we demonstrate a new method to control gain tilt in long wavelength erbium-doped fiber amplifiers by using an external light source in 1550-nm range (called control source). The wavelength or its input power is adjusted to reduce gain tilt. The tilted gain is diminished from 7.18 to 0.07 dB by adjusting control source wavelength, and from 9.95

Seongtaek Hwang; Kyuman Cho

2001-01-01

446

Design and performance of an erbium-doped silicon waveguide detector operating at 1.5 ?m  

Microsoft Academic Search

A new concept for an infrared waveguide detector based on silicon is introduced. It is fabricated using silicon-on-insulator material, and consists of an erbium-doped p-n junction located in the core of a silicon ridge waveguide. The detection scheme relies on the optical absorption of 1.5-?m light by Er3+ ions in the waveguide core, followed by electron-hole pair generation by the

P. G. Kik; A. Polman; S. Libertino; S. Coffa

2002-01-01

447

Seven-core erbium-doped double-clad fiber amplifier pumped simultaneously by side-coupled multimode fiber.  

PubMed

We demonstrate a seven-core erbium-doped fiber amplifier in which all the cores were pumped simultaneously by a side-coupled tapered multimode fiber. The amplifier has multicore (MC) MC inputs and MC outputs, which can be readily spliced to MC transmission fiber for amplifying space division multiplexed signals. Gain over 25 dB was obtained in each of the cores over a 40-nm bandwidth covering the C-band. PMID:24562260

Abedin, Kazi S; Fini, John M; Thierry, Taunay F; Zhu, Benyuan; Yan, Man F; Bansal, Lalit; Dimarcello, Frank V; Monberg, Eric M; DiGiovanni, David J

2014-02-15

448

Continuously Tunable Chirped Microwave Waveform Generation Using a Tilted Fiber Bragg Grating Written in an Erbium\\/Ytterbium Codoped Fiber  

Microsoft Academic Search

An optical approach to generating continuously tunable chirped microwave waveforms using a tilted fiber Bragg grating (TFBG) written in an erbium\\/ytterbium (Er\\/Yb) codoped fiber is proposed. By pumping the TFBG, the magnitude and group delay responses of the cladding mode resonances are changed, which can be used to implement a photonic microwave delay-line filter with increasing or decreasing tap spacing.

Hiva Shahoei; Jianping Yao

2012-01-01

449

On the possibility of increasing the pulse energy of a passively Q-switched erbium glass minilaser  

SciTech Connect

A simple method to increase the output energy of a passively Q-switched erbium glass laser is proposed. Using the amplitude modulation of losses at the active element face, the fundamental mode was reliably suppressed and the laser operated in a selected higher-order mode. The output energy was experimentally increased by a factor of 2.1, and the range of allowable pump energy instability was extended threefold. (lasers)

Izyneev, A A; Sadovskii, Pavel I [V.A.Kotel'nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Fryazino, Moscow Region (Russian Federation); Sadovskii, S P [Moscow Institute of Physics and Technology (State University), Dolgoprudnyi, Moscow Region, Russian Frderation (Russian Federation)

2010-08-03

450

Stable and uniform dual-wavelength erbium-doped fiber laser based on fiber Bragg gratings and photonic crystal fiber  

Microsoft Academic Search

Based on the fiber Bragg gratings (FBGs) and high nonlinear photonic crystal fiber (HN-PCF), a novel dual-wavelength erbium-doped fiber (EDF) laser is proposed and demonstrated. The experimental results show that, owing to the contributions of two degenerate four-wave mixings in the HN-PCF, the proposed fiber laser is great stable and two output signals are uniform at room temperature. With adjustment

Xueming Liu; Xiufeng Yang; Fuyun Lu; Junhong Ng; Xiaoqun Zhou; Chao Lu

2005-01-01

451

Switchable and tunable multiwavelength erbium-doped fiber laser with fiber Bragg gratings and photonic crystal fiber  

Microsoft Academic Search

We propose and report on a novel multiwavelength-switchable-tunable erbium-doped fiber laser with excellent stability and uniformity based on four-wave mixing (FWM) in a highly nonlinear photonic crystal fiber. By adjusting the attenuators, the single, dual, or triple wavelengths can be lasing simultaneously. Under the influence of the FWM, the spectrum is stabilized and the uniformity is less than 0.6 dB.

Xueming Liu; Xiaoqun Zhou; Xiufeng Tang; Junhong Ng; Jianzhong Hao; Teck Yoong Chai; Edward Leong; Chao Lu

2005-01-01

452

Switchable multi-wavelength erbium-doped fiber lasers by using cascaded fiber Bragg gratings written in high birefringence fiber  

Microsoft Academic Search

A novel and simple Erbium-doped fiber laser by using cascaded fiber Bragg gratings (FBGs) written in high-birefringence fibers for switchable multi-wavelength operation is proposed. Due to two-peak reflection with orthogonal polarizations of the FBG, the polarization hole-burning effect in the cavity is greatly enhanced. Experimental results show that the stable dual- and three-wavelength lasing operation with very narrow wavelength separation

Zhao Chun-Liu; Yang Xiufeng; Lu Chao; Ng Jun Hong; Guo Xin; Partha Roy Chaudhuri; Dong Xinyong

2004-01-01

453

Gain saturation effects in high-speed, multichannel erbium-doped fiber amplifiers at ?=1.53 ?m  

Microsoft Academic Search

Gain compression effects during multichannel signal amplification in an erbium-doped fiber amplifier at ?=1.53 are investigated. A theory is presented that accurately models the observed amplified spontaneous emission spectra, signal gains, and saturation effects. Measurements of the gain dynamics show recovery times in the 1-ms range, indicating that the fiber amplifier is immune to interchannel interference over a wide range

EMMANUEL DESURVIRE; C. RANDY GILES; JAY R. SIMPSON

1989-01-01

454

Broad-band erbium-doped fiber amplifier flattened beyond 40 nm using long-period grating filter  

Microsoft Academic Search

Broad-bandwidth amplification is essential for the construction of high-capacity multichannel communication systems. We describe a silica-based erbium doped fiber amplifier (EDFA) with a flat gain bandwidth exceeding 40 nm. The dual-stage EDFA includes a precisely designed inter-stage long-period fiber grating filter with more than 14-dB peak attenuation. By careful choice of the filter spectrum and fiber lengths, this EDFA is

Paul F. Wysocki; Justin B. Judkins; Rolando P. Espindola; Matthew Andrejco; Ashish M. Vengsarkar

1997-01-01

455

Thermodynamic model of the stabilization of an intermediate state in the region of the metamagnetic phase transition in erbium orthoferrite  

SciTech Connect

The possible mechanisms of the thermodynamic stabilization of an intermediate state in the first-order metamagnetic phase transition in a magnetic field parallel to the Ising c axis of the Er{sup 3+} ions in erbium orthoferrite at T = 1.6 K have been analyzed. The model is chosen using the magneto-optical experimental data on the features of this state.

Belyaeva, A. I., E-mail: belyaeva@kharkov.com; Baranova, E. V. [National Technical University Kharkov Polytechnic Institute (Ukraine)

2007-07-15

456

High-power and tunable operation of erbium-ytterbium co-doped cladding-pumped fiber lasers  

Microsoft Academic Search

We describe erbium-ytterbium co-doped fiber lasers in different free-running and tunable configurations. The lasers were cladding-pumped by high-power multimode diode sources. We compare pumping at 915 and 980 nm. With a free-running laser, we obtained slope efficiencies of up to 50% with 915-nm pumping and 38% with 980-nm pumping, with respect to absorbed pump power. We reached a double-ended output

Johan Nilsson; Shaif-Ul Alam; Jose A. Alvarez-Chavez; Paul W. Turner; W. Andrew Clarkson; Anatoly B. Grudinin

2003-01-01

457

Laser diode-pumped femtosecond erbium-doped fiber laser with a sub-ring cavity for repetition rate control  

Microsoft Academic Search

It is shown for the first time that the pulse repetition rate of a femtosecond erbium-doped fiber laser with a nonlinear amplifying loop mirror can be controlled by attaching a sub-ring linear cavity to the main cavity. The transit time in the sub-ring cavity is set as an inverse integer of that in the main cavity, resulting in an increase

Eiji Yoshida; Yasuo Kimura; Masataka Nakazawa

1992-01-01

458

Long-band emission of microsphere lasers based on erbium-doped sol-gel silica-alumina glasses  

Microsoft Academic Search

This letter reports on long-band (L band) lasing whispering-gallery modes (WGMs) in microspheres based on sol-gel silica-alumina glasses doped with high concentration of erbium ions (Er+3 from 1250 to 15 000 ppm). The sol-gel method for making these Er-doped silica-alumina glasses is described. The microspheres with diameters from 40 to 200 mum were built by electrical arc. The experimental results

Pham van Hoi; Chu Thi Thu Ha; Hoang Quang Hung

2005-01-01

459

Long-band emission of microsphere lasers based on erbium-doped sol-gel silica-alumina glasses  

Microsoft Academic Search

This letter reports on long-band (L band) lasing whispering-gallery modes (WGMs) in microspheres based on sol-gel silica-alumina glasses doped with high concentration of erbium ions (Er+3 from 1250 to 15 000 ppm). The sol-gel method for making these Er-doped silica-alumina glasses is described. The microspheres with diameters from 40 to 200 ?m were built by electrical arc. The experimental results

Pham Van Hoi; Chu Thi Thu Ha; Hoang Quang Hung

2005-01-01

460

The erbium: YAG laser: A review and preliminary report on resurfacing of the face, neck, and hands  

Microsoft Academic Search

The use of short-pulsed or flash-scanned CO2 lasers to resurface skin has rapidly joined chemical peels and dermabrasion as an accepted procedure. The purpose of this study was to evaluate a mid-infrared pulsed Erbium: YAG laser prospectively to determine its clinical efficacy for resurfacing of the face, neck, and hands. Postoperative changes and recovery period were also evaluated. A total

David H. McDaniel; Keith Ash; Jeff Lord; John Newman; Mark Zukowski

1997-01-01

461

Correlation between luminescent properties and structure organization in AlGaN\\/GaN superlattices annealed after erbium ion implantation  

Microsoft Academic Search

The evolution of the structure organization of MOCVD-grown AlGaN\\/GaN superlattices subjected to erbium ion implantation with\\u000a an energy of 1 MeV and dose of 3 1015 cm?2 and subsequent annealing is correlated with their photoluminescent properties. The structure organization is quantitatively\\u000a estimated using parameter ? (degree of violation of local symmetry), which is found via multifractal analysis of surface morphology

E. E. Baranov; A. M. Emel’yanov; W. V. Lundin; V. N. Petrov; V. I. Sakharov; I. T. Serenkov; N. A. Sobolev; A. N. Titkov; E. I. Shek; N. M. Shmidt

2006-01-01

462

Comparison of the effect of hand instruments, an ultrasonic scaler, and an erbium-doped yttrium aluminium garnet laser on root surface roughness of teeth with periodontitis: a profilometer study  

PubMed Central

Purpose The present study aimed to measure root surface roughness in teeth with periodontitis by a profilometer following root planning with ultrasonic and hand instruments with and without erbium-doped yttrium aluminium garnet (Er:YAG) laser irradiation. Methods Sixty single-rooted maxillary and mandibular teeth, extracted because of periodontal disease, were collected. The crowns and apices of the roots were cut off using a diamond bur and water coolant. The specimens were mounted in an acrylic resin block such that a plain root surface was accessible. After primary evaluation and setting a baseline, the samples were divided into 4 groups. In group 1, the samples were root planned using a manual curette. The group 2 samples were prepared with an ultrasonic scaler. In group 3, after scaling with hand instrumentation, the roots were treated with a Smart 1240D plus Er:YAG laser and in group 4, the roots were prepared with ultrasonic scaler and subsequently treated with an Er:YAG laser. Root surface roughness was then measured by a profilometer (MahrSurf M300+RD18C system) under controlled laboratory conditions at a temperature of 25? and 41% humidity. The data were analyzed statistically using analysis of variance and a t-test (P<0.05). Results Significant differences were detected in terms of surface roughness and surface distortion before and after treatment. The average reduction of the surface roughness after treatment in groups 1, 2, 3, and 4 was 1.89, 1.88, 1.40, and 1.52, respectively. These findings revealed no significant differences among the four groups. Conclusions An Er:YAG laser as an adjunct to traditional scaling and root planning reduces root surface roughness. However, the surface ultrastructure is more irregular than when using conventional methods.

Amid, Reza; Fekrazad, Reza; Hajizadeh, Farzin; Ghafoori, Arash

2013-01-01

463

Average power and pulse energy scaling of 1.6 ?m resonantly-diode-pumped erbium lasers  

NASA Astrophysics Data System (ADS)

Pulsed erbium lasers operating in the eye-safe spectral band around 1.6 ?m can find numerous defense and civil applications that often require high pulse energy, reasonable pulse repetition frequency (100 Hz), specific wavelength and last not least very good beam quality. Even though resonant pumping shifts a significant part of thermal load from gain medium to pumping diodes, fulfillment of all these requirements is still rather difficult, what can be attributed to spectroscopic limitations of erbium doped crystalline gain media as well as to low spatial brightness of available InP pumping diodes. In the paper we report recent breakthroughs in the field of pulsed erbium lasers. Main difficulties towards multi-ten-mJ output from systems based on the TIR (total- internal-reflection) pump scheme arrangement will be defined and solutions proposed. We also demonstrate for the first time to the best of our knowledge a Q-switched Er3+:YAG laser operating at the repetition rate of 100 Hz with truly diffraction limited beam quality (M2 =1) and pulse energy of up to 24mJ (damage free).

Galecki, Lukasz; Eichhorn, Marc; Zendzian, Waldemar

2013-10-01

464

Detecting Thermal Barrier Coating Delamination Using Visible and Near-Infrared Luminescence from Erbium-Doped Sublayers  

NASA Technical Reports Server (NTRS)

Nondestructive diagnostic tools are needed to monitor early stages of delamination progression in thermal barrier coatings (TBCs) because the risk of delamination induced coating failure will compromise engine performance and safety. Previous work has demonstrated that for TBCs composed of yttria-stabilized zirconia (YSZ), luminescence from a buried europium-doped sublayer can be utilized to identify the location of TBC delamination from the substantially higher luminescence intensity observed from the delaminated regions of the TBC. Luminescence measurements from buried europium-doped layers depend on sufficient transmittance of the 532 nm excitation and 606 nm emission wavelengths through the attenuating undoped YSZ overlayer to produce easily detected luminescence. In the present work, improved delamination indication is demonstrated using erbium-doped YSZ sublayers. For visible-wavelength luminescence, the erbium-doped sublayer offers the advantage of a very strong excitation peak at 517 nm that can be conveniently excited a 514 nm Ar ion laser. More importantly, the erbium-doped sublayer also produces near-infrared luminescence at 1550 nm that is effectively excited by a 980 nm laser diode. Both the 980 nm excitation and the 1550 nm emission are transmitted through the TBC with much less attenuation than visible wavelengths and therefore show great promise for delamination monitoring through thicker or more highly scattering TBCs. The application of this approach for both electron beam physical vapor deposited (EB-PVD) and plasma-sprayed TBCs is discussed.

Eldridge, J. I.; Bencic, T. J.; Martin, R. E.; Singh, J.; Wolfe, D. E.

2007-01-01

465

Wideband and flat-gain amplifier based on high concentration erbium-doped fibres in parallel double-pass configuration  

SciTech Connect

A wideband and flat gain erbium-doped fibre amplifier (EDFA) is demonstrated using a hybrid gain medium of a zirconiabased erbium-doped fibre (Zr-EDF) and a high concentration erbium-doped fibre (EDF). The amplifier has two stages comprising a 2-m-long ZEDF and 9-m-long EDF optimised for C- and L-band operations, respectively, in a double-pass parallel configuration. A chirp fibre Bragg grating (CFBG) is used in both stages to ensure double propagation of the signal and thus to increase the attainable gain in both C- and L-band regions. At an input signal power of 0 dBm, a flat gain of 15 dB is achieved with a gain variation of less than 0.5 dB within a wide wavelength range from 1530 to 1605 nm. The corresponding noise figure varies from 6.2 to 10.8 dB within this wavelength region.

Hamida, B A; Cheng, X S; Harun, S W; Naji, A W; Arof, H; Al-Khateeb, W; Khan, S; Ahmad, H

2012-03-31

466

Photocatalytic activity of erbium-doped TiO{sub 2} nanoparticles immobilized in macro-porous silica films  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Erbium-doped TiO{sub 2} nanoparticles were immobilized on macro-porous silica films. Black-Right-Pointing-Pointer The films were obtained by a phase separation process. Black-Right-Pointing-Pointer The samples exhibited photo-catalytic activity under visible light. Black-Right-Pointing-Pointer The sensitization of TiO{sub 2} was attributed to a red shift in the TiO{sub 2} band-gap. -- Abstract: A macro-porous silica film served as mechanical support to immobilize TiO{sub 2} nanoparticles, which were doped with erbium. The films and the nanoparticles were prepared by sol-gel route. The nanoparticles exhibited photocatalytic activity under visible light. We obtained a degradation rate of methylene blue that followed first order kinetics. The sensitization of the nanoparticles to visible light was attributed to a red shift in the band-gap of the TiO{sub 2} due to the addition of erbium ions.

Castaneda-Contreras, J., E-mail: jcc050769@yahoo.com.mx [C.U. de los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico); Maranon-Ruiz, V.F.; Chiu-Zarate, R.; Perez-Ladron de Guevara, H.; Rodriguez, R. [C.U. de los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico)] [C.U. de los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico); Michel-Uribe, C. [C. U. de Ciencias Exactas e Ingenieria, Universidad de Guadalajara, Guadalajara, Jalisco (Mexico)] [C. U. de Ciencias Exactas e Ingenieria, Universidad de Guadalajara, Guadalajara, Jalisco (Mexico)

2012-02-15

467

Wideband and flat-gain amplifier based on high concentration erbium-doped fibres in parallel double-pass configuration  

NASA Astrophysics Data System (ADS)

A wideband and flat gain erbium-doped fibre amplifier (EDFA) is demonstrated using a hybrid gain medium of a zirconiabased erbium-doped fibre (Zr-EDF) and a high concentration erbium-doped fibre (EDF). The amplifier has two stages comprising a 2-m-long ZEDF and 9-m-long EDF optimised for C- and L-band operations, respectively, in a double-pass parallel configuration. A chirp fibre Bragg grating (CFBG) is used in both stages to ensure double propagation of the signal and thus to increase the attainable gain in both C- and L-band regions. At an input signal power of 0 dBm, a flat gain of 15 dB is achieved with a gain variation of less than 0.5 dB within a wide wavelength range from 1530 to 1605 nm. The corresponding noise figure varies from 6.2 to 10.8 dB within this wavelength region.

Hamida, B. A.; Cheng, X. S.; Harun, S. W.; Naji, A. W.; Arof, H.; Al-Khateeb, W.; Khan, S.; Ahmad, H.

2012-03-01

468

Processing for optically active erbium in silicon by film co-deposition and ion-beam mixing  

NASA Astrophysics Data System (ADS)

Techniques of film deposition by co-evaporation, ion-beam assisted mixing, oxygen ion implantation, and thermal annealing were been combined in a novel way to study processing of erbium-in-silicon thin-film materials for optoelectronics applications. Structures with erbium concentrations above atomic solubility in silicon and below that of silicide compounds were prepared by vacuum co-evaporation from two elemental sources to deposit 200-270 nm films on crystalline silicon substrates. Ar + ions were implanted at 300 keV. Oxygen was incorporated by O +-ion implantation at 130 keV. Samples were annealed at 600 °C in vacuum. Concentration profiles of the constituent elements were obtained by Rutherford backscattering spectrometry. Results show that diffusion induced by ion-beam mixing and activated by thermal annealing depends on the deposited Si-Er profile and reaction with implanted oxygen. Room temperature photoluminescence spectra show Er 3+ transitions in a 1480-1550 nm band and integrated intensities that increase with the oxygen-to-erbium ratio.

Abedrabbo, S.; Mohammed, Q.; Fiory, A. T.

2009-02-01

469

N152G, -S, and -T Substitutions in CMY-2 ?-Lactamase Increase Catalytic Efficiency for Cefoxitin and Inactivation Rates for Tazobactam  

PubMed Central

Class C cephalosporinases are a growing threat, and clinical inhibitors of these enzymes are currently unavailable. Previous studies have explored the role of Asn152 in the Escherichia coli AmpC and P99 enzymes and have suggested that interactions between C-6? or C-7? substituents on penicillins or cephalosporins and Asn152 are important in determining substrate specificity and enzymatic stability. We sought to characterize the role of Asn152 in the clinically important CMY-2 cephalosporinase with substrates and inhibitors. Mutagenesis of CMY-2 at position 152 yields functional mutants (N152G, -S, and -T) that exhibit improved penicillinase activity and retain cephamycinase activity. We also tested whether the position 152 substitutions would affect the inactivation kinetics of tazobactam, a class A ?-lactamase inhibitor with in vitro activity against CMY-2. Using standard assays, we showed that the N152G, -S, and -T variants possessed increased catalytic activity against cefoxitin compared to the wild type. The 50% inhibitory concentration (IC50) for tazobactam improved dramatically, with an 18-fold reduction for the N152S mutant due to higher rates of enzyme inactivation. Modeling studies have shown active-site expansion due to interactions between Y150 and S152 in the apoenzyme and the Michaelis-Menten complex with tazobactam. Substitutions at N152 might become clinically important as new class C ?-lactamase inhibitors are developed.

Li, Mei; Conklin, Benjamin C.; Taracila, Magdalena A.; Hutton, Rebecca A.

2013-01-01

470

N152G, -S, and -T substitutions in CMY-2 ?-lactamase increase catalytic efficiency for cefoxitin and inactivation rates for tazobactam.  

PubMed

Class C cephalosporinases are a growing threat, and clinical inhibitors of these enzymes are currently unavailable. Previous studies have explored the role of Asn152 in the Escherichia coli AmpC and P99 enzymes and have suggested that interactions between C-6' or C-7' substituents on penicillins or cephalosporins and Asn152 are important in determining substrate specificity and enzymatic stability. We sought to characterize the role of Asn152 in the clinically important CMY-2 cephalosporinase with substrates and inhibitors. Mutagenesis of CMY-2 at position 152 yields functional mutants (N152G, -S, and -T) that exhibit improved penicillinase activity and retain cephamycinase activity. We also tested whether the position 152 substitutions would affect the inactivation kinetics of tazobactam, a class A ?-lactamase inhibitor with in vitro activity against CMY-2. Using standard assays, we showed that the N152G, -S, and -T variants possessed increased catalytic activity against cefoxitin compared to the wild type. The 50% inhibitory concentration (IC50) for tazobactam improved dramatically, with an 18-fold reduction for the N152S mutant due to higher rates of enzyme inactivation. Modeling studies have shown active-site expansion due to interactions between Y150 and S152 in the apoenzyme and the Michaelis-Menten complex with tazobactam. Substitutions at N152 might become clinically important as new class C ?-lactamase inhibitors are developed. PMID:23318801

Skalweit, Marion J; Li, Mei; Conklin, Benjamin C; Taracila, Magdalena A; Hutton, Rebecca A

2013-04-01

471

Profil ?pid?miologique des br?l?s ? Marrakech: ? propos de 152 cas  

PubMed Central

Summary Cet article concerne une étude épidémiologique rétrospective portant sur 152 patients brûlés hospitalisés entre 2006 et 2008. Les brûlés avaient moins de 20 ans dans 65% des cas. Le sex ratio (m/f) était de 1,18/1. L’origine thermique est incriminée dans 84% des cas. L’atteinte par flammes représente 56% des cas. La surface corporelle brûlée moyenne chez nos patients était de 28%, et les brûlures de deuxième degré étaient de loin les plus fréquentes. Dans notre série, le visage et le cou étaient le siège le plus fréquemment touché. La prévention reste la meilleure arme pour lutter contre ce fléau, et pour cela plusieurs mesures sont proposées pour améliorer l’état actuel des choses.

Ibnouzahir, M.; Ettalbi, S.; Ouahbi, S.; Droussi, H.; Sousou, M.; Chlihi, A.; Bahaichar, N.; Boukind, H.

2011-01-01

472

Population of the yrast superdeformed band in 152Dy within a cluster approach  

NASA Astrophysics Data System (ADS)

By using the dinuclear system approach combined with quantum diffusion and statistical methods, the population of the yrast superdeformed band in the 152Dy nucleus is treated. The excitation functions are calculated and analyzed for the population of the superdeformed states in xn, pxn, and ?xn evaporation channels of different asymmetric and almost symmetric reactions. The dependencies of the relative intensities of E2 transitions between the rotational states of the superdeformed band on the de-excitation channels, charge asymmetry of the entrance channel, and beam energy are established. The restrictions of the population of the superdeformed band in spin by complete fusion and quasifission processes are shown. The calculated results are compared with the available experimental data.

Zubov, A. S.; Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.

2013-09-01

473

Electroencephalographic source imaging: a prospective study of 152 operated epileptic patients  

PubMed Central

Electroencephalography is mandatory to determine the epilepsy syndrome. However, for the precise localization of the irritative zone in patients with focal epilepsy, costly and sometimes cumbersome imaging techniques are used. Recent small studies using electric source imaging suggest that electroencephalography itself could be used to localize the focus. However, a large prospective validation study is missing. This study presents a cohort of 152 operated patients where electric source imaging was applied as part of the pre-surgical work-up allowing a comparison with the results from other methods. Patients (n = 152) with >1 year postoperative follow-up were studied prospectively. The sensitivity and specificity of each imaging method was defined by comparing the localization of the source maximum with the resected zone and surgical outcome. Electric source imaging had a sensitivity of 84% and a specificity of 88% if the electroencephalogram was recorded with a large number of electrodes (128–256 channels) and the individual magnetic resonance image was used as head model. These values compared favourably with those of structural magnetic resonance imaging (76% sensitivity, 53% specificity), positron emission tomography (69% sensitivity, 44% specificity) and ictal/interictal single-photon emission-computed tomography (58% sensitivity, 47% specificity). The sensitivity and specificity of electric source imaging decreased to 57% and 59%, respectively, with low number of electrodes (<32 channels) and a template head model. This study demonstrated the validity and clinical utility of electric source imaging in a large prospective study. Given the low cost and high flexibility of electroencephalographic systems even with high channel counts, we conclude that electric source imaging is a highly valuable tool in pre-surgical epilepsy evaluation.

Brodbeck, Verena; Spinelli, Laurent; Lascano, Agustina M.; Wissmeier, Michael; Vargas, Maria-Isabel; Vulliemoz, Serge; Pollo, Claudio; Schaller, Karl; Michel, Christoph M.

2011-01-01

474

Magnetic properties of Ni50Mn34.8In15.2 probed by Mössbauer spectroscopy  

NASA Astrophysics Data System (ADS)

Structural and magnetic properties of a Ni50Mn34.8In15.2 ferromagnetic shape memory alloy doped by F57e at the Mn sites have been studied by x-ray diffraction, Mössbauer spectroscopy and superconducting quantum interference device magnetometry. Obtained experimental results have disclosed unique magnetostructural transition from a high-temperature ferromagnetic austenitic phase to a low-temperature paramagnetic martensitic phase at Mf=290K . Complex magnetic ordering which can be classified as a cluster glass state is formed in Ni50Mn34.3F57e0.5In15.2 on further cooling below TCM=162K . The abnormal magnetostructural transition observed in Ni50Mn34.3F57e0.5In15.2 is suggested to originate from the weakening of exchange interactions due to an abrupt change in Mn-Mn interatomic distances occurring upon the martensitic transformation.

Khovaylo, V. V.; Kanomata, T.; Tanaka, T.; Nakashima, M.; Amako, Y.; Kainuma, R.; Umetsu, R. Y.; Morito, H.; Miki, H.

2009-10-01

475

A regulatory circuit of miR-148a/152 and DNMT1 in modulating cell transformation and tumor angiogenesis through IGF-IR and IRS1  

PubMed Central

Dysregulation of microRNAs is a common feature in human cancers, including breast cancer (BC). Here we describe the epigenetic regulation of miR-148a and miR-152 and their impact on BC cells. Due to the hypermethylation of CpG island, the expression levels of both miR-148a and miR-152 (miR-148a/152) are decreased in BC tissues and cells. DNMT1, the DNA methyltransferase 1 for the maintenance methylation, is aberrantly up-regulated in BC and its overexpression is responsible for hypermethylation of miR-148a and miR-152 promoters. Intriguingly, we found that DNMT1 expression, which is one of the targets of miR-148a/152, is inversely correlated with the expression levels of miR-148a/152 in BC tissues. Those results lead us to propose a negative feedback regulatory loop between miR-148a/152 and DNMT1 in BC. More importantly, we demonstrate that IGF-IR and IRS1, often overexpressed in BC, are two novel targets of miR-148a/152. Overexpression of miR-148a or miR-152 significantly inhibits BC cell proliferation, colony formation, and tumor angiogenesis via targeting IGF-IR and IRS1 and suppressing their downstream AKT and MAPK/ERK signaling pathways. Our results suggest a novel miR-148a/152-DNMT1 regulatory circuit and reveal that miR-148a and miR-152 act as tumor suppressors by targeting IGF-IR and IRS1, and that restoration of miR-148a/152 expression may provide a strategy for therapeutic application to treat BC patients.

Xu, Qing; Jiang, Yue; Yin, Yu; Li, Qi; He, Jun; Jing, Yi; Qi, Yan-Ting; Xu, Qian; Li, Wei; Lu, Bo; Peiper, Stephen S.; Jiang, Bing-Hua; Liu, Ling-Zhi

2013-01-01

476

Contact focusing multimodal probes for potential use in ophthalmic surgery with the Erbium:YAG laser  

NASA Astrophysics Data System (ADS)

Vitreoretinal surgery is performed using mechanical dissection that sometimes results in iatrogenic complications, including vitreous hemorrhage, retinal breaks, incomplete membrane delamination, retinal distortion, microscopic damage, etc. The laser probe would be an ideal tool for cutting away pathologic membranes, however the depth of surgery should be precisely controlled to protect the retina. In this study, we optimized the design of such ultraprecise surgical microprobe formed by chains of dielectric spheres assembled directly inside the cores of the mid-infrared flexible delivery systems used in such surgeries. Specifically, our design is optimized for use of Erbium:YAG laser sources with extremely short optical penetration depth in tissue. By using numerical modeling, we demonstrate a potential advantage of five-sphere focusing chains of sapphire or ruby spheres with index n=1.71 for ablating the tissue with self-limited depth around 10-20 ?m. We fabricated and tested such optimized structures formed by 300 ?m ruby spheres with ophthalmic tissues, ex vivo. Single Er:YAG pulses of 0.2 mJ and 75 ?s duration produced ablation craters in cornea epithelium for one, three, and five sphere structures with the latter generating the smallest crater depth (10 ?m) with the least amount of thermal damage depth (30 ?m). We show that integration of the ultraprecise laser ablation capability with illumination and suction tools would produce a single headpiece with versatile functionality in ultraprecise intraocular surgery.

Darafsheh, Arash; Hutchens, Thomas C.; Fardad, Amir; Antoszyk, Andrew N.; Ying, Howard S.; Fried, Nathaniel M.; Astratov, Vasily N.

2013-03-01

477

A practical numerical theory for light propagation in erbium-doped waveguide amplifiers  

NASA Astrophysics Data System (ADS)

The complex transverse waveguide geometries twinned with the transcendental rate equations governing Erbium-Doped Waveguide Amplifiers (EDWA) warrant the application of intricate Numerical Methods. To date all models approaching the problem have incorporated a finite element scheme for the modal analysis of the waveguide in conjunction with either a Beam Propagation Method (BPM) or an explicit Runge-Kutta procedure towards solving the channel propagation equations. In deploying these models, a certain ambiguity lies in their practical utilisation enforcing a trade-off between simulation time and demands on computer memory. The underlying theory of the finite element method (FEM) for optical waveguide simulations comprises of a multitude of approaches to solving the scalar Helmholtz equation. Past FEM techniques were based on a combination of matrix sparsity manipulations and iterative techniques but today, even modest computers can be utilised in more direct but denser methods for eigenvalue solutions. This paper aspires to demonstrate an efficient modal analysis technique founded on an appropriate mesh with due consideration for both computational complexity and available Random Access Memory requirements. It is then trivial to continue from this modal field definition to the solution of the aforementioned rate equations for channel gain, noise or nonlinear losses including upconversion and cross relaxation in the EDWA by implementing a suitable boundary value problem approach.

Ging, J. A.; O'Dowd, R. F.

2005-06-01

478

Laser-diode-pumped, erbium-doped, solid-state laser with high slope efficiency  

SciTech Connect

A laser and method for producing a laser emission at a wavelength of substantially 2.8 microns is disclosed. In a preferred embodiment of the invention, the laser comprises laser diode means for emitting a pump beam at a preselected wavelength; and a crystal having a preselected host material doped with a predetermined percent concentration of erbium activator ions sufficient to produce a laser emission at substantially 2.8 microns at a slope efficiency of at least 5 percent, but preferrably 10 percent, when the crystal is pumped by the pump beam. It is well known that the human body is comprised of approximately 70% water, with various human tissues containing about 60% to 90% of water, and bone and cartilage containing about 30% to 40% of water. Since the 2.8 micron wavelength has a substantially maximum absorption in water, this 2.8 micron wavelength is the ideal wavelength to use for a large variety of medical laser applications on the human body. A 2.8 micron wavelength laser could be used for precise surgery in such exemplary applications as brain surgery, neurosurgery, eye surgery, plastic surgery, burn treatment and the removal of malignancies.

Esterowitz, L.; Allen, R.; Kintz, G.

1989-10-31

479

Erbium(III) in aqueous solution: an ab initio molecular dynamics study.  

PubMed

Structural and dynamical properties of the erbium(III) ion in water have been obtained by means of ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) simulations for the ground state and an excited state. The quality of the simulations has been monitored by recording UV/vis and Raman spectra of dilute solutions of ErCl3 and Er(NO3)3 in water and by comparison with EXAFS data from literature. Slight deviations between these data can be mainly attributed to relativistic effects, which are not sufficiently considered by the methodological framework. In both simulations, a mixture of coordination numbers eight and nine and a ligand exchange on the picosecond range are observed. The strength of the Er-ligand bond is considerably lower than that of trivalent transition metal ions but higher than that for La(III) and Ce(III) in aqueous solution. The main difference between ground state and excited state is the ligand exchange rate of the first shell. The second hydration shell is stable in both cases but with significantly different properties. PMID:24251538

Canaval, Lorenz R; Sakwarathorn, Theerathad; Rode, Bernd M; Messner, Christoph B; Lutz, Oliver M D; Bonn, Günther K

2013-12-01

480

Percutaneous Bone Marrow Transplantation Using Fractional Ablative Erbium:YAG Laser.  

PubMed

Topical application of therapeutic agents has been a mainstay in Dermatology for the treatment of skin disorders but is not commonly used for systemic delivery. For a topically applied agent to reach distant body sites it must first overcome the barrier function of the skin and then penetrate into deeper structures before reaching the systemic circulation. This has limited the use of topically applied agents to those having specific charge, solubility and size restrictions. Pretreatment of the skin with ablative fractional laser appears to enhance the uptake of some topically applied drugs but the ability to effectively deliver agents to distant sites is largely unproven. In this report we used a fractional ablative Erb:YAG (Erbium/Yttrium Aluminum Garnet) laser to facilitate the transfer of bone marrow stem cells through the skin in a murine bone marrow transplant model. Chimerism could be detected in the peripheral blood of recipient C57BL/6 mice that were pretreated with ablative fractional laser and had topically applied enhanced green fluorescent protein (GFP) labeled bone marrow cells from syngeneic donor transgenic mice. This study indicates that fractional laser can be used to deliver stem cells through the skin and remain functionally intact. PMID:24667438

Rodriguez-Menocal, Luis; Salgado, Marcela; Davis, Stephen; Waibel, Jill; Shabbir, Arsalan; Cox, Audrey; Badiavas, Evangelos V

2014-01-01

481

Temperature dependence of the enhanced excited state absorption in erbium-doped garnets  

NASA Astrophysics Data System (ADS)

Temperature dependence of an enhanced excited state absorption was investigated in erbium-doped garnet crystals using 787.3 and 787.8 nm laser diodes. The enhanced absorption was obtained at temperature ranges of 15-570 K, 15-420 K, and 15-1200 K in a yttrium aluminum garnet, a yttrium scandium gallium garnet, and a lutetium aluminum garnet, respectively. Absorption peaks corresponding to both the 4I15/2-4I9/2 and the 4I13/2-2H11/2 transitions of Er3+ in garnets were shifted from those for 300 K at high temperature. The enhanced absorption weakened at high temperature because an absorption cross section from the 4I13/2 level to the 2H11/2 level decreased due to the shift of the absorption peaks. It has been confirmed that a mechanism of the enhanced absorption can be explained by calculating the rate equations based on an analytical model for a five-level system of the Er3+ ion. It is suggested that the enhanced absorption weakened at temperatures lower than 12 K because the number of phonons decreased due to low temperature.

Maeda, Yoshinobu; Yamada, Toshikazu

1998-06-01

482

Laser diode pumped, erbium-doped, solid state laser with high slope efficiency  

NASA Astrophysics Data System (ADS)

A laser and method for producing a laser emission at a wavelength of substantially 2.8 microns is disclosed. In a preferred embodiment of the invention, the laser comprises laser diode means for emitting a pump beam at a preselected wavelength; and a crystal having a preselected host material doped with a predetermined percent concentration of erbium activator ions sufficient to produce a laser emission at substantially 2.8 microns at a slope efficiency of at least 5 percent, but preferrably 10 percent, when the crystal is pumped by the pump beam. It is well known that the human body is comprised of approximately 70 percent water, with various human tissues containing about 60 to 90 percent of water, and bone and cartilage containing about 30 to 40 percent of water. Since the 2.8 micron wavelength has a substantially maximum absorption in water, this 2.8 micron wavelength is the ideal wavelength to use for a large variety of medical laser applications on the human body. A 2.8 micron wavelength laser could be used for precise surgery in such exemplary applications as brain surgery, neurosurgery, eye surgery, plastic surgery, burn treatment, and the removal of malignancies.

Esterowitz, Leon; Allen, R.; Kintz, G.

1989-10-01

483

High pressure phase transitions in the rare earth metal erbium to 151 GPa.  

PubMed

High pressure x-ray diffraction studies have been performed on the heavy rare earth metal erbium (Er) in a diamond anvil cell at room temperature to a pressure of 151 GPa and Er has been compressed to 40% of its initial volume. The rare earth crystal structure sequence hcp ? Sm type ? dhcp ? distorted fcc (hcp: hexagonal close packed; fcc: face centered cubic; dhcp: double hcp) is observed in Er below 58 GPa. We have carried out Rietveld refinement of crystal structures in the pressure range between 58 GPa and 151 GPa. We have examined various crystal structures that have been proposed for the distorted fcc (dfcc) phase and the post-dfcc phase in rare earth metals. We find that the hexagonal hR 24 structure is the best fit between 58 and 118 GPa. Above 118 GPa, a structural transformation from hR 24 phase to a monoclinic C 2/m phase is observed with a volume change of - 1.9%. We have also established a clear trend for the pressure at which a post-dfcc phase is formed in rare earth metals and show that there is a monotonic increase in this pressure with the filling of 4f shell. PMID:21753243

Samudrala, Gopi K; Thomas, Sarah A; Montgomery, Jeffrey M; Vohra, Yogesh K

2011-08-10

484

Highly efficient precipitation of phosphoproteins using trivalent europium, terbium, and erbium ions.  

PubMed

This study describes a highly efficient method for the selective precipitation of phosphoproteins by trivalent europium, terbium, and erbium metal ions. These metal cations belong to the group of lanthanides and are known to be hard acceptors with an overwhelming preference for oxygen-containing anions such as phosphates to which they form very tight ionic bonds. The method could be successfully applied to specifically precipitate phosphoproteins from complex samples including milk and egg white by forming solid metal-protein complexes. Owing to the low solubility product of the investigated lanthanide salts, the produced metal-protein complexes showed high stability. The protein pellets were extensively washed to remove nonphosphorylated proteins and contaminants. For the analysis of proteins the pellets were first dissolved in 30 % formic acid and subjected to matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS. For peptide mass-fingerprint analysis the precipitated phosphoproteins were enzymatically digested using microwave-assisted digestion. The method was found to be highly specific for the isolation and purification of phosphoproteins. Protein quantification was performed by colorimetric detection of total precipitated phosphoproteins and revealed more than 95 % protein recovery for each lanthanide salt. PMID:22451172

Güzel, Yüksel; Rainer, Matthias; Mirza, Munazza Raza; Bonn, Günther K

2012-05-01

485

Temperature-Insensitive Bend Sensor Using Entirely Centered Erbium Doping in the Fiber Core  

PubMed Central

A fiber based bend sensor using a uniquely designed Bend-Sensitive Erbium Doped Fiber (BSEDF) is proposed and demonstrated. The BSEDF has two core regions, namely an undoped outer region with a diameter of about 9.38 ?m encompassing a doped, inner core region with a diameter of 4.00 ?m. The doped core region has about 400 ppm of an Er2O3 dopant. Pumping the BSEDF with a conventional 980 nm laser diode gives an Amplified Spontaneous Emission (ASE) spectrum spanning from 1,510 nm to over 1,560 nm at the output power level of about ?58 dBm. The ASE spectrum has a peak power of ?52 dBm at a central wavelength of 1,533 nm when not spooled. Spooling the BSEDF with diameters of 10 cm to 2 cm yields decreasing peak powers from ?57.0 dBm to ?61.8 dBm, while the central wavelength remains unchanged. The output is highly stable over time, with a low temperature sensitivity of around ?0.005 dBm/°C, thus allowing for the development of a highly stable sensor system based in the change of the peak power alone.

Ahmad, Harith; Zulkifli, Mohd Zamani; Muhammad, Farah Diana; Samangun, Julian Md; Abdul-Rashid, Hairul Azhar; Harun, Sulaiman Wadi

2013-01-01

486

Widely tunable wavelength spacing dual-wavelength single longitudinal mode erbium doped fiber laser  

NASA Astrophysics Data System (ADS)

A simple widely tunable wavelength spacing dual-wavelength single longitudinal mode (SLM) erbium doped fiber laser (EDFL) based on cascaded fiber Bragg gratings (FBGs) and birefringent fiber filter is proposed and demonstrated. Experimental results show that the lasing wavelength spacing is widely tunable in a range from 2 nm to 18 nm, which has potential to generate frequency tunable terahertz (THz) waves by beating the lasing dual-wavelength in a high speed photodetector. The birefringent fiber filter acts as an ultra-narrow bandpass filter and benefits the simultaneous oscillation of dual-wavelength in a single laser cavity. The output peak power of the lasing dual-wavelength is approximately equalized at room temperature, and a high optical signal-to-noise ratio (OSNR) is realized in the whole tuning range. The SLM operation of dual-wavelength fiber laser is verified by Fabry–Perot (F–P) scanning interferometer, and the clear eye diagram proves that the proposed fiber laser is effective in the application of fiber optic communication system.

Sun, Tiegang; Guo, Yubin; Wang, Tianshu; Huo, Jiayu; Zhang, Le

2014-06-01

487

Adhesion after erbium, chromium:yttrium-scandium-gallium-garnet laser application at three different irradiation conditions.  

PubMed

The aim of this study was to investigate whether distinct cooling of low fluence erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation would influence adhesion. Main factors tested were: substrates (two), irradiation conditions (three), and adhesives (three). A 750 microm diameter tip was used, for 50 s, 1 mm from the surface, with a 0.25 W power output, 20 Hz, energy density of 2.8 J/cm(2) with energy per pulse of 12.5 mJ. When applied, water delivery rate was 11 ml/min. The analysis of variance (ANOVA) showed that laser conditioning significantly decreased the bond strength of all adhesive systems applied on enamel. On dentin, laser conditioning significantly reduced bond strength of etch-and-rinse and one-step self-etch systems; however, laser irradiation under water cooling did not alter bonding of two-step self-etching. It may be concluded that the irradiation with Er,Cr:YSGG laser at 2.8 J/cm(2) with water coolant was responsible for a better adhesion to dentin, while enamel irradiation reduced bond strength, irrespective of cooling conditions. PMID:18027064

Botta, Sérgio Brossi; da Ana, Patricia Aparecida; Zezell, Denise Maria; Powers, John M; Matos, Adriana Bona

2009-01-01

488

Temperature-insensitive bend sensor using entirely centered Erbium doping in the fiber core.  

PubMed

A fiber based bend sensor using a uniquely designed Bend-Sensitive Erbium Doped Fiber (BSEDF) is proposed and demonstrated. The BSEDF has two core regions, namely an undoped outer region with a diameter of about 9.38 ?m encompassing a doped, inner core region with a diameter of 4.00 ?m. The doped core region has about 400 ppm of an Er2O3 dopant. Pumping the BSEDF with a conventional 980 nm laser diode gives an Amplified Spontaneous Emission (ASE) spectrum spanning from 1,510 nm to over 1,560 nm at the output power level of about -58 dBm. The ASE spectrum has a peak power of -52 dBm at a central wavelength of 1,533 nm when not spooled. Spooling the BSEDF with diameters of 10 cm to 2 cm yields decreasing peak powers from -57.0 dBm to -61.8 dBm, while the central wavelength remains unchanged. The output is highly stable over time, with a low temperature sensitivity of around ~0.005 dBm/°C, thus allowing for the development of a highly stable sensor system based in the change of the peak power alone. PMID:23881146

Ahmad, Harith; Zulkifli, Mohd Zamani; Muhammad, Farah Diana; Samangun, Julian Md; Abdul-Rashid, Hairul Azhar; Harun, Sulaiman Wadi

2013-01-01

489

Percutaneous Bone Marrow Transplantation Using Fractional Ablative Erbium:YAG Laser  

PubMed Central

Topical application of therapeutic agents has been a mainstay in Dermatology for the treatment of skin disorders but is not commonly used for systemic delivery. For a topically applied agent to reach distant body sites it must first overcome the barrier function of the skin and then penetrate into deeper structures before reaching the systemic circulation. This has limited the use of topically applied agents to those having specific charge, solubility and size restrictions. Pretreatment of the skin with ablative fractional laser appears to enhance the uptake of some topically applied drugs but the ability to effectively deliver agents to distant sites is largely unproven. In this report we used a fractional ablative Erb:YAG (Erbium/Yttrium Aluminum Garnet) laser to facilitate the transfer of bone marrow stem cells through the skin in a murine bone marrow transplant model. Chimerism could be detected in the peripheral blood of recipient C57BL/6 mice that were pretreated with ablative fractional laser and had topically applied enhanced green fluorescent protein (GFP) labeled bone marrow cells from syngeneic donor transgenic mice. This study indicates that fractional laser can be used to deliver stem cells through the skin and remain functionally intact.

Rodriguez-Menocal, Luis; Salgado, Marcela; Davis, Stephen; Waibel, Jill; Shabbir, Arsalan; Cox, Audrey; Badiavas, Evangelos V.

2014-01-01

490

Nonlinear optical properties of erbium doped zinc oxide (EZO) thin films  

NASA Astrophysics Data System (ADS)

Undoped and Erbium (Er) doped zinc oxide (EZO) thin films were deposited on glass substrate by sol-gel method using spin coating technique with different doping concentration. EZO films were characterized using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), UV-VIS-NIR transmission and single beam z scan method under illumination of frequency doubled Nd:YAG laser. The deposited films were found to be well crystallized with hexagonal wurtzite structure having a preferential growth orientation along the ZnO (002) plane. A blue-shift was observed in the band gap of EZO films with increasing Er concentration. All the films exhibited a negative value of nonlinear refractive index (n2) at 532 nm which is attributed to the two photon absorption and weak free carrier absorption. Third order nonlinear optical susceptibility, ?(3) values of EZO films were observed in the remarkable range of 10- 6 esu. EZO (0.4 at.%) sample was found to be the best optical limiter with limiting threshold of 1.95 KJ/cm2.

Kumari, Vinay; Kumar, Vinod; Malik, B. P.; Mehra, R. M.; Mohan, Devendra

2012-04-01

491

Histologic comparison of needle, holmium:YAG, and erbium:YAG endoscopic goniotomy  

NASA Astrophysics Data System (ADS)

An endoscope allows visualization of the anterior chamber angle in porcine eyes despite the presence of cloudy corneas. The pectinate ligaments in the anterior chamber angle are a surgical model for primary infantile glaucoma. This study investigated the histologic results, one month after treating the anterior chamber angle with a goniotomy needle, the holmium:YAG laser, or the erbium:YAG laser coupled to a small endoscope. The anterior chambers were deepened with a viscoelastic material in one-month-old anesthetized pigs. An Olympus 0.8 mm diameter flexible endoscope was externally coupled to a 23 gauge needle or a 300 micron diameter fiber. The angle was treated for 120 degrees by one of the three methods, and the probe was removed. During the acute study, all three methods cut the pectinate ligaments. The histologic findings one month after healing demonstrated minimal surrounding tissue damage following goniotomy with a needle and the most surrounding tissue damage following treatment with the holmium:YAG laser.

Joos, Karen M.; Shen, Jin-Hui; Rivera, Brian; Hernandez, Eleut; Shetlar, Debra

1995-05-01

492

Effects of CO2, thulium, and erbium lasers on middle ear synthetic implants  

NASA Astrophysics Data System (ADS)

10.6 micrometers CO2, 2.01 micrometers Thulium:YAG (Tm:YAG) and 2.94 micrometers Erbium:YAG (Er:YAG) are currently being used or investigated for potential applications in otologic surgery. In addition to biologic tissue there are numerous synthetic materials (Gelfoam, Silastic, C-Flex, Silicone and Teflon), mineral components (Hydroxylapatite) and metals (stainless steel) that may be encountered during surgery. Their behavior in response to laser irradiation is, for the most part, unknown. We investigated the effects of these lasers, operated at clinically relevant parameters on these materials. We looked for signs of melting, perforation, charring, smoke formation and ignition. The results show that wet Gelfoam proved to be a partially effective barrier to all lasers. Silastic transmitted the energy of the Tm and Er:YAG with minimal damage, but charred, ignited or exploded with the CO2 depending on the energy applied. All lasers melted C-Flex at higher energies. On Silicon, CO2 produced flames, char and melting; the other lasers produced a tiny spark and less melting. Teflon charred and perforated when exposed to any laser, but only Tm:YAG produced a spark. All lasers at moderate and high energies shattered hydroxylapatite. Stainless steel was not affected by CO2, but was perforated by Tm:YAG and Er:YAG. The results suggest that none of the tested lasers are safe for all currently used prosthetic materials and therefore they should be used with caution.

Bottrill, Ian; Valtonen, Hannu J.; Poe, Dennis S.

1995-05-01

493

High-energy, in-band pumped erbium doped fiber amplifiers.  

PubMed

We have demonstrated and compared high-energy, in-band pumped erbium doped fiber amplifiers operating at 1562.5 nm under both a core pumping scheme (CRS) and a cladding pumping scheme (CLS). The CRS/CLS sources generated smooth, single-peak pulses with maximum pulse energies of ~1.53/1.50 mJ, and corresponding pulse widths of ~176/182 ns respectively, with an M2 of ~1.6 in both cases. However, the conversion efficiency for the CLS was >1.5 times higher than the equivalent CRS variant operating at the same pulse energy due to the lower pump intensity in the CLS that mitigates the detrimental effects of ion concentration quenching. With a longer fiber length in a CLS implementation a pulse energy of ~2.6 mJ is demonstrated with a corresponding M2 of ~4.2. Using numerical simulations we explain that the saturation of pulse energy observed in our experiments is due to saturation of the pump absorption. PMID:23038520

Lim, Ee-Leong; Shaif-ul Alam; Richardson, David J

2012-08-13

494

Water flow on erbium:yttrium-aluminum-garnet laser irradiation: effects on dental tissues.  

PubMed

Since lasers were introduced in dentistry, there has been considerable advancement in technology. Several wavelengths have been investigated as substitutes for high-speed air turbine. Owing to its high absorbability in water and hydroxyapatite, the erbium:yttrium-aluminum-garnet (Er:YAG) laser has been of great interest among dental practitioners and scientists. In spite of its great potential for hard tissue ablation, Er:YAG laser effectiveness and safety is directly related to an adequate setting of the working patterns. It is assumed that the ablation rate is influenced by certain conditions, such as water content of the target tissue, and laser parameters. It has been shown that Er:YAG irradiation with water coolant attenuates temperature rise and, hence, minimizes the risk of thermally induced pulp injury. It also increases ablation efficiency and enhances adhesion to the lased dental tissue. The aim of this review was to obtain insights into the ablation process and to discuss the effects of water flow on dental tissue ablation using Er:YAG laser. PMID:18425563

Colucci, Vivian; do Amaral, Flávia Lucisano Botelho; Pécora, Jesus Djalma; Palma-Dibb, Regina Guenka; Corona, Silmara Aparecida Milori

2009-09-01

495

Synthesis, characterization and properties of erbium-based nanofibres and nanorods  

NASA Astrophysics Data System (ADS)

Low-dimensional nanostructures (nanofibres, nanorods and nanolayers) can be selectively synthesized from erbium oxide hydroxide ErOOH using a facile hydrothermal method. The ErOOH nanofibres are monoclinic with diameters in the range of 6-30 nm. Some of the nanofibres grow into branches of the same size. This nanomaterial was obtained in subcritical water in a batch reactor at pH 12, temperature 300 °C, pressure 25 MPa and reaction time of 2-22 h. Increasing the pH to 13 under the same experimental conditions led to the production of nanorods instead of nanofibres with diameters of 20-100 nm. Decreasing the pH to 6, again with no other variation in experimental conditions, had a dramatic effect—a new crystalline phase of star-like nanolayers was formed. Subsequent dehydration of the nanofibres at 800 °C led to the formation of Er2O3, which had the same morphology as the nanofibres. The crystallinity, morphology and other structural features of the ErOOH-based nanomaterials have been investigated by field SEM, XRD, TEM, SAED (selected-area electron diffraction) and BET measurements of the surface area. In addition, the infrared, UV-visible and fluorescence spectra of the nanomaterials have been measured.

Assaaoudi, H.; Fang, Z.; Barralet, J. E.; Wright, A. J.; Butler, I. S.; Kozinski, J. A.

2007-11-01

496

Poly[aqua-(?2-oxalato)(4-oxidopyri-din-ium)erbium(II)  

PubMed Central

The title complex, [Er(C5H5NO)(C2O4)(H2O)]n, is a new erbium polymer based on oxalate and 4-oxidopyridinium ligands. The ErII center is coordinated by six O atoms from three oxalate ligands, one O atom from a 4-oxidopyridinium ligand and one water mol­ecule, and displays a distorted square-anti­prismatic coordination geometry. The oxalate ligands are both chelating and bridging, and link ErII ions, forming Er–oxalate layers in which the attached water and 4-oxidopyridinium units point alternately up and down. A mirror plane passes through the Er atom, one C, the oxide O and two oxalate O atoms. The layers are assembled into a three-dimensional supra­molecular network via inter­molecular hydrogen bonding and ?–? stacking inter­actions [centroid–centroid distances of 3.587?(2)?Å between parallel pyridinium rings]. Both the water mol­ecule and the 4-oxidopyridinium ligand are disordered over two sites in a 1:1 ratio.

Gu, Chang-Sheng; Hao, Xiao-Min; Song, Wen-Dong; Lin, Hai-Sheng; Ma, De-Yun

2008-01-01

497

Hierarchical recruitment of Plk4 and regulation of centriole biogenesis by two centrosomal scaffolds, Cep192 and Cep152  

PubMed Central

Centrosomes play an important role in various cellular processes, including spindle formation and chromosome segregation. They are composed of two orthogonally arranged centrioles, whose duplication occurs only once per cell cycle. Accurate control of centriole numbers is essential for the maintenance of genomic integrity. Although it is well appreciated that polo-like kinase 4 (Plk4) plays a central role in centriole biogenesis, how it is recruited to centrosomes and whether this step is necessary for centriole biogenesis remain largely elusive. Here we showed that Plk4 localizes to distinct subcentrosomal regions in a temporally and spatially regulated manner, and that Cep192 and Cep152 serve as two distinct scaffolds that recruit Plk4 to centrosomes in a hierarchical order. Interestingly, Cep192 and Cep152 competitively interacted with the cryptic polo box of Plk4 through their homologous N-terminal sequences containing acidic-?-helix and N/Q-rich motifs. Consistent with these observations, the expression of either one of these N-terminal fragments was sufficient to delocalize Plk4 from centrosomes. Furthermore, loss of the Cep192- or Cep152-dependent interaction with Plk4 resulted in impaired centriole duplication that led to delayed cell proliferation. Thus, the spatiotemporal regulation of Plk4 localization by two hierarchical scaffolds, Cep192 and Cep152, is critical for centriole biogenesis.

Kim, Tae-Sung; Park, Jung-Eun; Shukla, Anil; Choi, Sunho; Murugan, Ravichandran N.; Lee, Jin H.; Ahn, Mija; Rhee, Kunsoo; Bang, Jeong K.; Kim, Bo Y.; Loncarek, Jadranka; Erikson, Raymond L.; Lee, Kyung S.

2013-01-01

498

Stress Corrosion Cracking in Nickel-Base Alloys 690 and 152 Weld in Simulated PWR Environment: 2009.  

National Technical Information Service (NTIS)

Alloys 600 and 182 are used as structural materials in pressurized water reactors (PWRs) and have been found to undergo stress corrosion cracking (SCC). Alloys 690 and 152 are the replacement materials of choice for Alloys 600 and 182, respectively. The p...

B. Alexandreanu W. J. Shack Y. Chen Y. Yang

2012-01-01

499

Determination of the Nuclear Electric Charge Distribution of Samarium Isotopes 144, 148, 150, 152, 154 by the Muonic Atom Method.  

National Technical Information Service (NTIS)

The theory of the nucleus-negative muon system in the case of electrical interactions is discussed. The interactions of muons with the samarium isotopes 152, 154, 144, 148, 150 are investigated. After a description of the experimental device, from muon be...

P. Barreau

1977-01-01

500

Saturated liquid densities and bubble-point pressures of the binary HFC 152a+HCFC 142b system  

NASA Astrophysics Data System (ADS)

Forty-eight sets of the saturated liquid densities and bubble-point pressures of the binary HFC 152a + HCFC 142b system were measured with a magnetic densimeter coupled with a variable-volume cell. The measurements obtained at four compositions, 20, 40, 60, and 80 wt%, of HFC 152a cover a range of temperatures from 280 to 400 K. The experimental uncertainties in temperature, pressure, density, and composition were estimated to be within ±15mK, ±20kPa, ±0.2%, and between -0.14 and ±0.01 wt% HFC 152a (-0.01 and + 0.14 wt% HCFC 142b), respectively. The purities of the samples were 99.9 wt% for HFC 152a and 99.8 wt% for HCFC 142b. A binary interaction parameter, k ij , in the Peng-Robinson equation of state was determined as a function of temperature for representing the bubble-point pressures. On the other hand, two constant binary-interaction parameters, k ij and l ij , were introduced into the mixing rule of the Hankinson-Brobst-Thomson equation for representing the saturated liquid densities.

Maezawa, Y.; Widiatmo, J. V.; Sato, H.; Watanabe, K.

1991-11-01