128 research outputs found

    Magneto-optical Constants Of Fluoride Optical Crystals And Other Ab2 And A2b Type Compounds

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    Measurements of the magneto-optical rotation at visible wavelengths for the optical crystals MgF2, CaF2, SrF2, BaF2 and PbF2 are reported. A pulsed magnetic field between 50 and 80 kG was used. The PbF2 crystal was shown to be a good choice for the construction of optical isolators operating in the near UV. From the data, the magneto-optic anomaly factor Îł for each sample was calculated and magneto-optic constants reported in the literature for other compounds with the general formulae AB2 and A2B were compiled. The magneto-optic anomaly factors for these types of materials are analysed in terms of Pauling's electronegativity.921527532757Barnes, N.P., Petway, L.B., (1992) J. Opt. Soc. Am. B: Opt. Phys, 9, p. 1912Ling, H.Y., (1994) J. Opt. Soc. Am. A, 11, p. 754Munin, E., Villaverde, A.B., (1991) J. Phys. Condens. Matter, 3, p. 5099Guerrero, H., Escudero, J.L., Bernabeu, E., (1992) Opt. Lett., 17, p. 760Munin, E., Roversi, J.A., Villaverde, A.B., (1992) J. Phys. D: Appl. Phys., 25, p. 1635Weber, M.J., (1986) Proc. SPIE-Int. Soc. Opt. Eng., 681, p. 75Wilson, D.K., (1991) Laser Focus World, 27, p. 175Schulz, P.A., (1989) Appl. Opt., 28, p. 4458Wunderlich, J.A., Deshazer, L.G., (1977) Appl. Opt., 16, p. 1584Gauthier, D.J., Narum, P., Boyd, R.W., (1986) Opt. Lett., 11, p. 623Villaverde, A.B., (1981) J. Phys. E: Sci. Instrum., 14, p. 1073Johnson Jr., T.F., Proffitt, W., (1980) IEEE J. Quantum Electron., 16, p. 483Schulz, P.A., (1988) IEEE J. Quantum Electron., 12, p. 1039Malecki, J., Surma, M., Gibalewickz, J., (1957) Acta Phys. Pol., 16, p. 151Deeter, M.N., Rose, A.H., Day, G.W., (1990) J. Lightwave Technol., 8, p. 1838Rose, A.H., Deeter, M.N., Day, G.W., (1993) Opt. Lett., 18, p. 1471Ning, Y.N., Jackson, D.A., (1993) Opt. Lett., 18, p. 835Pistoni, N.C., Martinelli, M., (1993) Opt. Lett., 18, p. 314Wanninger, P., Valdez, E.C., Shay, T.M., (1992) IEEE Photon Technol. Lett., 4, p. 94Munin, E., (1996) IEEE Trans. Magn., 32, p. 316Boswarva, I.M., Howard, R.E., Lidiard, A.B., (1962) Proc. R. Soc. London Ser. A, 269, p. 125Kolodziejczak, J., Lax, B., Nishina, Y., (1962) Phys. Rev., 128, p. 2655Balkanski, M., Amzallag, E., Langer, D., (1966) J. Phys. Chem. Solids, 27, p. 299Ramaseshan, S., (1948) Proc. Indian Acad. Sci. A, 28, p. 360Darwin, C.G., Watson, W.H., (1927) Proc. R. Soc. London Ser. A, 114, p. 474Pauling, L., (1960) The Nature of the Chemical Bond, , Cornell University Press, New York, 3rd edn(1974) Hoya Faraday Rotator Glass Report, , Hoya Optics Inc., TokioIoshino, I., (1980) Jpn. J. Appl. Phys., 19, p. 7451Miles, P.A., Dodge, M.J., Ballard, S.S., Browder, J.S., Feldman, A., Weber, M.J., (1986) CRC Handbook of Laser Science and Technology, 4, pp. 24-41. , ed. M. J. Weber, CRC Press Inc., Boca Raton, FLGrevendonk, W., Van Den Abeele, L., Van Den Keybus, P., Vanhuyse, B., Ruymbeek, G., (1981) Phys. Stat. Solidi B, 108, pp. K53Baer, W.S., (1967) J. Phys. Chem. Solids, 28, p. 677Cronemeyer, D.C., (1952) Phys. Rev., 87, p. 876Becquerel, M.H., (1897) Comptes Rendus, 125, p. 679Dynasil Synthetic Fused Silica Catalogue 302M, , Dynasil Corporation, Berlin, NJBalbin Villaverde, A., Donatti, D.A., (1979) J. Chem. Phys., 71, p. 4021Forsythe, W.E., (1969) Smithsonian Physics Tables, p. 530. , Washington, 9th ednIngersoll, L.R., Liebenberg, D.H., (1958) J. Opt. Soc. Am., 48, p. 339Fox, J.J., Tate, F.G.H., (1930) International Critical Tables of Numerical Data, Physics, Chemistry and Technology, 7, p. 01. , ed. E. W. Washburn, McGraw Hill, New York, 1st ednCook Jr., W.R., Jaffe, H., (1972) American Institute of Physics Handbook, p. 230. , ed., D. E. Gray, McGraw Hill, New York, 3rd edn., ch. 6Wells, A.F., (1984) Structural Inorganic Chemistry, , Oxford University Press, Oxford, 5th ednCole, H., (1950) J. Soc. Glass Technol., 34, p. 22

    Photothermal Spectroscopic Characterization In Teliurite Glasses Codoped With Rare-earth Ions

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    Thermal Lens (TL) and spectroscopic characterizations were performed in 70TeO2-19WO3-7Na2O-4Nb2O 5 (mol%) tellurite glasses. TL measurements were accomplished in Er3+/Tm3+ co-doped tellurite glasses in function of the Tm2O3 concentration (0.4 -1.6 ×1020 ions/cm3). Fluorescence spectra at 488 nm showed that Er 3+/Tm3+co-doped tellurite glasses present several emission bands between (500-1800) nm. However, the more iniense emission bands correspond to the Er3+ and Tm3+ transitions ( 4I13/2 → 4I15/2 and 3F4 → 3H6), respectively. The absolute nonradiative quantum efficiency (φ) was determined by TL method. Higher values of φ were obtained with the increase of Tm2O 3 concentration inside of the Er3+/Tm3+ co-doped tellurite glasses. These results are corroborated by the Judd-Ofelt calculations.6116Ryba-Romanowski, W., Effect of Temperature and activator concentration on luminescence decay of erbium-doped tellurite glass (1990) J. Lumin., 46, pp. 163-172Tanabe, S., Hirao, K., Soga, N., Upconversion fluorescences of TeO2 and Ga2O 3. based oxide glasses containing Er3+ (1990) J. Non-cryst. Solids, 122, pp. 79-82Inoue, S., Nukui, A., Yamamoto, K., Yano, T., Shibata, S., Yamane, M., Refractive index patterning of tellurite glass surfaces by ultra short pulse laser spot heating (2002) J. Mater. Sci., 37, pp. 3459-3465Huang, L., Jha, A., Shen, S., Chung, W.J., Visible emissions at 592 and 613 nm in Er3+-Eu3+ -codoped tellurite fibers (2004) Opt. Commun., 239, pp. 403-408Chillece, E.F., Rodriguez, E., Neves, A.A.R., Moreira, W.C., César, C.L., Barbosa, L.C., Er3+-Tm3+ co-doped tellurite fibers for broadband optical fiber amplifier around 1550 nm band (2005) Opt. Fiber Tech.Tanabe, S., Suzuki, K., Soga, N., Hanada, T., Mechanisms and concentration dependence of Tm3+ blue and Er3+ green up-con version in codoped glasses by red-laser pumping (1995) J. Lumin., 65, pp. 247-255Dai, S.X., Yang, J.H., Liu, Z.P., Wen, L., Hu, L.L., Jiang, Z.H., The luminescence of Er3+, Yb3+, Tm 3+-codoped tellurite glass pumped at 970 nm (2003) Acta Physica Sinica, 52, pp. 729-735Shen, S.X., Jha, A., Huang, L.H., Joshi, P., 980-nm diode-pumped Tm3+/Yb3+-codoped tellurite fiber for S-band amplification (2005) Optics Letters, 30, pp. 1437-1439Shen, X., Nie, Q., Xu, T., Peng, T., Gao, Y., Green and red upconversion emission and energy-transfer between Er 3+ and Tm3+ions in tellurite glasses (2004) Phys. Lett. A, 332, pp. 101-106Daf, S., Yang, J., Xu, S., Dai, N., Hu, L., Jiang, Z., The spectroscopic properties of Er3+, Yb3+, Tm 3+ -codoped tellurite glass (2003) Proc. SPIE, 4990, pp. 150-156. , Rare-Earth-Doped Materials and Devices Vil, S. Jiang, J. Lucas (Eds.)Lima, S.M., Sampaio, J.A., Catuncla, T., Bento, A.C., Miranda, L.C.M., Baesso, M.L., Mode-mismatched thermal lens spcctrometry for thermo-optical properties measurement in optical glasses: A review (2000) J. Non-cryst. Solids, 273, pp. 215-227Sampaio, J.A., Catunda, T., Gama, S., Baesso, M.L., Thermo-optical properties of OH-free erbium-doped low silica calcium aluminosilicate glasses measured by thermal lens technique (2001) J. Non-cryst. Solids, 284, pp. 210-216Lima, S.M., De Camargo, A.S.S., Nunes, L.A.O., Catunda, T., Fluorescence quantum efficiency measurements of excitation and nonradiative deexcitation processes of rare earth 4f-states in chalcogenide glasses (2002) Appl. Phys. Lett., 81, pp. 589-591Oliveira, S.L., Lima, S.M., Catunda, T., Nunes, L.A.O., Rohling, J.H., Bento, A.C., Baesso, M.L., High fluorescence quantum efficiency of 1.8 μm emission in Tm-dopcd low silica calcium aluminate glass determined by thermal lens spectroscopy (2004) Appl. Phys. Lett., 84, pp. 359-361Jacinto, C., Oliveira, S.L., Nunes, L.A.O., Catunda, T., Bell, M.J.V., Thermal lens study of the OH influence on the fluorescence efficiency of Yb3+ -doped phosphate glasses (2005) Appl. Phys. Lett., 86Sampaio, J.A., Gama, S., Baesso, M.L., Catunda, T., Fluorescence quantum efficiency of Er3+ in low silica calcium aluminate glasses determined by mode-mismatched thermal lens spectromctry (2005) J. Non-cryst. Solids, 351, pp. 1594-1602Pilla, V., Lima, S.M., Catunda, T., Medina, A., Baesso, M.L., Jenssen, H.P., Cassanho, A., Thermal quenching of the fluorescence quantum efficiency in colquiriite crystals measured by thermal lens spcctrometry (2004) J. Opt. Soc. Am. B., 21, pp. 1784-1791Pilla, V., Catunda, T., Balogh, D.T., Faria, R.M., Zilio, S.C., Thermal lensing in Polyvinyl alcoholVpolyaniline blends (2002) J. Polym. Sc., Part B Polym. Physics, 40, pp. 1949-1956Lima, S.M., Catunda, T., Lebullenger, R., Hernandes, A.C., Baesso, M.L., Bento, A.C., Miranda, L.C.M., Temperature dependence of thermo-optical properties of fluoride glasses determined by thermal lens spectrometry (1999) Phys. Rev. B, 60, pp. 15173-15178Lima, S.M., Sampaio, J.A., Catunda, T., De Camargo, A.S.S., Nunes, L.A.O., Baesso, M.L., Hewak, D.W., Spectroscopy, thermal and optical properties of Nd3+ -doped chalcogenide glasses (2001) J. Non-cryst. Solids, 284, pp. 274-281Zou, X., Izumitani, T., Spectroscopic properties and mechanisms of excited state absorption and energy transfer upconversion for Er3+ -doped glasses (1993) J. Non-cryst. Solids, 162, pp. 68-8

    High Verdet Constant Ga:s:la:o Chalcogenide Glasses For Magneto-optical Devices

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    The magneto-optical rotation at room temperature was measured for three Ga:S:La:O chalcogenide glasses at several laser lines in the visible. The first sample was a binary system constituted by 70 mol % Ga2S3 and 30 mol % La2O3, whereas in the second and third ones the lanthanum oxide was partially substituted by lanthanum sulfide, keeping the amount of gallium sulfide fixed. A pulsed magnetic field between 50 and 80 kG was used for the Faraday rotation measurements. The Verdet constant for one of the ternary samples was found to be as high as 0.205 min G-1 cm-1 at 543 nm, indicating that these chalcogenide glasses are very promising for magneto-optical applications. The data for each sample were fitted using the expected analytical expression for the magneto-optical dispersion. Measurements of the refractive index of the glasses at 632.8 nm are also reported. Data on the magneto-optical properties of two high Verdet constant, heavy-metal oxide diamagnetic glasses are also included for comparison. Š 1999 Society of Photo-optical Instrumentation Engineers.382214219Schweizer, T., Hewark, D.W., Payne, D.N., Jensen, T., Huber, G., Rare-earth doped chalcogenide glass laser (1996) Electron. Lett., 32 (7), pp. 666-667Hewark, D.W., Samson, B.N., Medeiros Neto, J.A., Laming, R.I., Payne, D.N., Emission at 1.3 Οm from dysprosium-doped GaLaS glass (1994) Electron. Lett., 30 (12), pp. 968-970Kumta, P.N., Risbud, S.H., Rare-earth chalcogenides - An emerging class of optical materials (1994) J. Mater. Sci., 29 (5), pp. 1135-1157De Araujo, M.T., Vermelho, M.V.D., Gouveia Neto, A.S., Sombra, A.S., Medeiros Neto, J.A., Efficient second harmonic generation in praseodymium doped Ga:La:S glass for 1.3 Οm optical fiber amplifiers (1996) IEEE Photonics Technol. Lett., 8 (6), pp. 821-823Schulz, P.A., Wavelength independent Faraday isolator (1989) Appl. Opt., 28 (20), pp. 4458-4464Wunderlich, J.A., DeShazer, L.G., Visible optical isolator using ZnSe (1977) Appl. Opt., 16 (6), pp. 1584-1587Gauthier, D.J., Narum, P., Boyd, R.W., Simple, compact, high-performance permanent-magnet Faraday isolator (1986) Opt. Lett., 11 (10), pp. 623-625Malecki, J., Surma, M., Gibalewickz, J., Measurements of the intensity of transient magnetic fields by the Faraday effect (1957) Acta Phys. Pol., 16 (1-2), pp. 151-156Deeter, M.N., Rose, A.H., Day, G.W., Fast, sensitive magnetic field sensors based on the Faraday effect in YIG (1990) J. Lightwave Technol., 8 (12), pp. 1838-1842Rose, A.H., Deeter, M.N., Day, G.W., Submicroampere-perroot-hertz current sensor based on the Faraday effect in Ga:YIG (1993) Opt. Lett., 18 (17), pp. 1471-1473Ning, Y.N., Jackson, D.A., Faraday effect optical current clamp using a bulk-glass sensing element (1993) Opt. Lett., 18 (10), pp. 835-837Pistoni, N.C., Martinelli, M., Vibration-insensitive fiber-optic current sensor (1993) Opt. Lett., 18 (4), pp. 314-316Wilson, D.K., Optical isolators adapt to communication needs (1991) Laser Focus World, 27 (4), pp. 175-180Balbin Villaverde, A., Munin, E., Pedroso, C.B., Linear displacement sensor based on the magneto-optical Faraday effect (1998) Sens. Actuators A, 70, pp. 211-218Munin, E., Balbin Villaverde, A., Magneto-optical rotatory dispersion of some non-linear crystals (1991) J. Phys.: Condens. Matter, 3 (27), pp. 5099-5106Munin, E., Roversi, J.A., Balbin Villaverde, A., Faraday effect and energy gap in optical materials (1992) J. Phys. D, 25 (11), pp. 1635-1639Boswarva, I.M., Howard, R.E., Lidiard, A.B., Faraday effect in semiconductors (1962) Proc. R. Soc. London, Ser. A, 269, pp. 125-141Balkanski, M., Amzaliag, E., Langer, D., Interband Faraday rotation of II-IV compounds (1966) J. Phys. Chem. Solids, 27, pp. 299-308Ramaseshan, S., Determination of the magneto-optic anomaly of some glasses (1946) Proc.-Indian Acad. Sci., Sect. A, 24, pp. 426-432Cole, H., Magneto-optic effects in glass I. Some preliminary observations on the application of magneto-optic properties to structural considerations (1950) J. Soc. Glass Technol., 34, pp. 220-237Sivaramakrishnan, V., Dispersion of Faraday rotation in some optical glasses (1957) J. Ind. Inst. Sci., A39, pp. 19-26Borrelli, N.F., Faraday rotation in glasses (1964) J. Chem. Phys., 41 (11), pp. 3289-3293Balbin Villaverde, A., Vasconcellos, E.C.C., Magnetooptical dispersion of HOYA glasses: AOT-5, AOT-44B and FR-5 (1982) Appl. Opt., 21 (8), pp. 1347-1348Borrelli, N.F., Dumbaugh, W.H., Electro- and magneto-optic effects in heavy metal oxide glasses (1987) Infrared Optical Materials and Fibers, Proc. SPIE, 843, pp. 6-9Pedroso, C.B., Munin, E., Balbin Villaverde, A., Aranha, N., Solano Reynoso, V.C., Barbosa, L.C., Magnetooptical rotation of heavy-metal oxide glasses (1998) J. Non-Cryst. Solids, 271, pp. 134-142Petrovskii, G.T., Edelman, I.S., Zarubina, T.V., Malakhovskii, A.V., Zabluda, V.N., Ivanov, M.Yu., Faraday effect and spectral properties of high-concentrated rare earth oxide glasses in visible and near UV region (1991) J. Non-Cryst. Solids, 130 (1), pp. 35-40Barnes, N.P., Petway, L.B., Variation of the Verdet constant with temperature of terbium gallium garnet (1992) J. Opt. Soc. Am. B, 9 (10), pp. 1912-1915Van Den Tempel, C.M.N., Model of a new temperature-compensated optical current sensor using Bi12SiO20 (1993) Appl. Opt., 32 (25), pp. 4869-4874Darwin, C.G., Watson, W.H., The constant of the magnetic dispersion of light (1927) Proc. R. Soc. London, Ser. 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    Laser Performance Of Cr4+-Y2Sio5

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    Laser action in Cr4+ doped yttrium-orthosilicate Cr4+:Y2SiO5 cooled to 77 K was demonstrated for the first time with 1064 and 532 nm pumping from a pulsed Nd:YAG laser and broad band (@ 840 nm) pumping from a Q-switched Cr:LiSAF laser

    Effectiveness of physiotherapy exercise following hip arthroplasty for osteoarthritis: a systematic review of clinical trials

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    Background: Physiotherapy has long been a routine component of patient rehabilitation following hip joint replacement. The purpose of this systematic review was to evaluate the effectiveness of physiotherapy exercise after discharge from hospital on function, walking, range of motion, quality of life and muscle strength, for osteoarthritic patients following elective primary total hip arthroplasty. Methods: Design: Systematic review, using the Cochrane Collaboration Handbook for Systematic Reviews of Interventions and the Quorom Statement. Database searches: AMED, CINAHL, EMBASE, KingsFund, MEDLINE, Cochrane library (Cochrane reviews, Cochrane Central Register of Controlled Trials, DARE), PEDro, The Department of Health National Research Register. Handsearches: Physiotherapy, Physical Therapy, Journal of Bone and Joint Surgery (Britain) Conference Proceedings. No language restrictions were applied. Selection: Trials comparing physiotherapy exercise versus usual/standard care, or comparing two types of relevant exercise physiotherapy, following discharge from hospital after elective primary total hip replacement for osteoarthritis were reviewed. Outcomes: Functional activities of daily living, walking, quality of life, muscle strength and range of hip joint motion. Trial quality was extensively evaluated. Narrative synthesis plus meta-analytic summaries were performed to summarise the data. Results: 8 trials were identified. Trial quality was mixed. Generally poor trial quality, quantity and diversity prevented explanatory meta-analyses. The results were synthesised and meta-analytic summaries were used where possible to provide a formal summary of results. Results indicate that physiotherapy exercise after discharge following total hip replacement has the potential to benefit patients. Conclusion: Insufficient evidence exists to establish the effectiveness of physiotherapy exercise following primary hip replacement for osteoarthritis. Further well designed trials are required to determine the value of post discharge exercise following this increasingly common surgical procedure

    Locomotor adaptability in persons with unilateral transtibial amputation

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    Background Locomotor adaptation enables walkers to modify strategies when faced with challenging walking conditions. While a variety of neurological injuries can impair locomotor adaptability, the effect of a lower extremity amputation on adaptability is poorly understood. Objective Determine if locomotor adaptability is impaired in persons with unilateral transtibial amputation (TTA). Methods The locomotor adaptability of 10 persons with a TTA and 8 persons without an amputation was tested while walking on a split-belt treadmill with the parallel belts running at the same (tied) or different (split) speeds. In the split condition, participants walked for 15 minutes with the respective belts moving at 0.5 m/s and 1.5 m/s. Temporal spatial symmetry measures were used to evaluate reactive accommodations to the perturbation, and the adaptive/de-adaptive response. Results Persons with TTA and the reference group of persons without amputation both demonstrated highly symmetric walking at baseline. During the split adaptation and tied post-adaptation walking both groups responded with the expected reactive accommodations. Likewise, adaptive and de-adaptive responses were observed. The magnitude and rate of change in the adaptive and de-adaptive responses were similar for persons with TTA and those without an amputation. Furthermore, adaptability was no different based on belt assignment for the prosthetic limb during split adaptation walking. Conclusions Reactive changes and locomotor adaptation in response to a challenging and novel walking condition were similar in persons with TTA to those without an amputation. Results suggest persons with TTA have the capacity to modify locomotor strategies to meet the demands of most walking conditions despite challenges imposed by an amputation and use of a prosthetic limb

    An appraisal of rehabilitation regimes used for improving functional outcome after total hip replacement surgery

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    This study aimed to systematically review the literature with regards to studies of rehabilitation programmes that have tried to improve function after total hip replacement (THR) surgery. 15 randomised controlled trials were identified of which 11 were centre-based, 2 were home based and 2 were trials comparing home and centre based interventions. The use of a progressive resistance training (PRT) programme led to significant improvement in muscle strength and function if the intervention was carried out early (< 1 month following surgery) in a centre (6/11 centre-based studies used PRT), or late (> 1 month following surgery) in a home based setting (2/2 home based studies used PRT). In direct comparison, there was no difference in functional measures between home and centre based programmes (2 studies), with PRT not included in the regimes prescribed. A limitation of the majority of these intervention studies was the short period of follow up. Centre based program delivery is expensive as high costs are associated with supervision, facility provision, and transport of patients. Early interventions are important to counteract the deficit in muscle strength in the affected limb, as well as persistent atrophy that exists around the affected hip at 2 years post-operatively. Studies of early home-based regimes featuring PRT with long term follow up are needed to address the problems currently associated with rehabilitation following THR
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