Electronic Structure Of Amorphous Si3n4 In The Cluster-bethe-lattice Approximation

We present a calculation of the electronic structure of amorphous Si3N4, using a model tight-binding Hamiltonian with a basis set of Si 3s and 3p, and N 2s and 2p orbitals. Clusters of 13 atoms, centered at either a Si or a N atom, are constructed using structural data from crystalline 2-Si3N4. These clusters are employed to generate a self-consistent transfer-matrix approximation for an infinite effective medium (Bethe lattice). The local and average densities of states are evaluated using standard one-particle Greens operator techniques. We also simulate photoemission spectra by weighting orbitally decomposed partial densities of states with appropriate photoemission cross sections. Our results are in good agreement with recent experimental data. © 1985 The American Physical Society.32128332833

Photo Acoustic Study Of Plants Exposed To Varying Light Intensity Growth Conditions: Spectral And Morphological Changes

In this paper we describe results of photo acoustic (PA) measurements carried out on various plants exposed to varying light intensity conditions. Depending on the species and light intensity conditions, the PA absorption spectra show differences in peaks associated with pigments and the cuticle. These differences are related to the spatial distribution of the pigments that differs from plant to plant. We have also performed systematic study of oxygen evolution at different wavelengths. The obtained oxygen spectra are equivalent to the action spectra usually acquired by determining the CO2 uptake and energy storage. The intensities of oxygen spectra exhibit differences depending on distinct morphology of plant. © EDP Sciences.125745748Marquezini, M.V., Cella, N., Mansanares, A.M., Vargas, H., Miranda, L.C.M., (1991) Meas. Sci. Technol., 2, p. 396Barja, P.R., Mansanares, A.M., (1998) Instrum. Sci. Technol., 26, p. 209Barja, P.R., Mansanares, A.M., Da Silva, E.C., Magalhães, A.C.N., Alves, P.L.C.A., (2001) Photosynthetica, 39, p. 489Salisbury, F.B., Ross, C.W., (1992) Plant Physiology, , Wadsworth Publishing Company, CaliforniaClark, J.B., Lister, G.R., (1975) Plant Physiol., 55, p. 401Carpentier, R., Larue, B., Leblanc, R.M., (1983) J. Physique Colloque C6, 44 (10 SUPL), pp. 355-360Veeranjaneyulu, K., Charland, M., Charlebois, D., Leblanc, R.M., (1991) Photosynth. Res., 30, p. 13

Phase-resolved Photoacoustic Spectroscopy And Epr Investigation Of Mno2- And Coo-doped Soda-lime Glasses

A discussion on the use of the phase shifts of the photoacoustic signal of different constituents of a composite sample for resolving their individual spectra is presented. It is experimentally shown that as long as we are interested in a qualitative analysis the method is simple and fast. For a quantitative analysis in which the nonradiative relaxation time and the characteristic diffusion time within the optical-absorption depth are sought, the method presents some limitations. This is demonstrated using MnO2- and CoO-doped soda-lime silica glass samples. © 1989 The American Physical Society.40318801884CAS; Chinese Academy of Sciences; DFG; Chinese Academy of Sciences; NRF; Chinese Academy of Sciences; NSFC; Chinese Academy of Sciences; PSI; Chinese Academy of Sciences; RAS; Chinese Academy of Sciences; RFBR; Chinese Academy of Sciences; RPF; Chinese Academy of Sciences; STFC; Chinese Academy of Science

Thermal Diffusivity Of Palladium-hydrogen Systems At Room Temperature Using Photothermal Detection

We report results of measurements on the thermal diffusivity, specific heat and electrical resistivity of hydrogenated-palladium samples. It is shown that repetition of the hydrogenation process with the same sample induces aging effects, which lead to erroneous results. The results for the thermal-property measurements on single-cycled palladium samples reflected a phase transition between -PdH and -PdH as the hydrogen concentration is increased. © 1992 The American Physical Society.4595031503

Reguladores Vegetais E Sombreamento Na Emergência De Plântulas De Macadâmia

This study aimed to evaluate the effect of plant growth regulators and shading on seed germination of macadamia nut trees. The experiment was conducted in a seedling production nursery of the company "QueenNut Macadâmia" located in the "Palmeiras" Farm, Dois Córregos, São Paulo (SP) state, Brazil. The Treatments were T1: water (control) under a shading screen, T2: GA4+7 + N-(phenylmethyl)-aminopurine (Promalin®) at 200 mL L-1 under a shading screen, T3: Promalin® at 400 mL L-1 under a shading screen, T4: gibberellic acid (GA3) + kinetin (Kt) + 3- indolebutyric acid (IBA) - Stimulate® at 5 mL kg-1 seeds under a shading screen, T5: Stimulate® at 10 mL kg-1 of seeds under a shading screen, and T6: water (control) under no shading screen. Seeds were soaked in the solutions or in water containing plant growth regulators for 24 hours. Then, they were dried and sown in sand. 450 seeds were used for each treatment. The evaluations began from seedling emergence by counting the total number of seedlings per treatment. A high average of macadamia nut tree seedling emergence was obtained in the treatments GA4+7 + N-(phenylmethyl)-aminopurine (Promalin®) 400 mL L-1 with Sombrite® (75.7%), GA4+7 + N-(phenylmethyl)-aminopurine (Promalin®) 200 mL L-1 (72.6%) Sombrite® and water (control) without Sombrite® (71.5%). © 2016, Universidade Federal de Uberlandia. All rights reserved.3251263126

Photoacoustic And Esr Studies Of Iron-doped Soda-lime Glasses: Thermal Diffusivity

The photoacoustic technique is used to measure the thermal diffusivity of iron-doped soda-lime glasses. To explain the thermal diffusivity behavior as a function of the iron content in the samples, electron-spin-resonance data were used. It is concluded that the main reason for the observed changes in the thermal diffusivity is the ferric ion entering substitutionally at the Si4+ sites. © 1989 The American Physical Society.40117912791

Electron Spin Resonance G Shift In Gd5 Si4, Gd5 Ge4, And Gd5.09 Ge2.03 Si1.88

Gd5 Si4, Gd5 Ge4, and Gd5.09 Ge2.03 Si1.88 compounds were studied by electron spin resonance. The arc-melted samples were initially characterized by optical metallography, x-ray diffraction, and static magnetization measurements. The electron spin resonance results show a negative paramagnetic g shift for Gd5 Si4 and Gd5.09 Ge2.03 Si1.88, and a smaller positive one for Gd5 Ge4. The values of the exchange parameter (j) between the localized Gd-4f spins and the conduction electrons are obtained from the g shifts. These values are positive and of the same order of magnitude for Gd5 Si4 and Gd5.09 Ge2.03 Si1.88, and negative one order of magnitude smaller for Gd5 Ge4. The electron spin resonance data were interpreted considering the strongly bottlenecked solution of the coupled Bloch-Hasegawa equations. © 2006 The American Physical Society.7314Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494. , PRLTAO 0031-9007 10.1103/PhysRevLett.78.4494Pecharsky, V.K., Gschneidner Jr., K.A., (1997) J. Alloys Compd., 260, p. 98. , JALCEU 0925-8388 10.1016/S0925-8388(97)00143-6Choe, W., Pecharsky, V.K., Pecharsky, A.O., Gschneidner Jr., K.A., Young Jr., V.G., Miller, G.J., (2000) Phys. Rev. Lett., 84, p. 4617. , PRLTAO 0031-9007 10.1103/PhysRevLett.84.4617Levin, E.M., Pecharsky, V.K., Gschneidner Jr., K.A., (2000) Phys. Rev. B, 62, p. 14625. , PRBMDO 0163-1829 10.1103/PhysRevB.62.R14625Szade, J., Skorek, G., (1999) J. Magn. Magn. Mater., 196-197, p. 699. , JMMMDC 0304-8853Levin, E.M., Pecharsky, V.K., Gschneidner Jr., K.A., (1999) Phys. Rev. B, 60, p. 7993. , PRBMDO 0163-1829 10.1103/PhysRevB.60.7993Harmon, B.N., Antonov, V.N., (2002) J. Appl. Phys., 91, p. 9815. , JAPIAU 0021-8979 10.1063/1.1461896Levin, E.M., Pecharsky, V.K., Gschneidner Jr., K.A., Miller, G.J., (2001) Phys. Rev. B, 64, p. 235103. , PRBMDO 0163-1829 10.1103/PhysRevB.64.235103Skorek, G., Deniszczyk, J., Szade, J., (2002) J. Phys.: Condens. Matter, 14, p. 7273. , JCOMEL 0953-8984 10.1088/0953-8984/14/30/316Samolyuk, G.D., Antropov, V.P., (2002) J. Appl. Phys., 91, p. 8540. , JAPIAU 0021-8979 10.1063/1.1455614Pecharsky, V.K., Samolyuk, G.D., Antropov, V.P., Pecharsky, A.O., Gschneidner Jr., K.A., (2003) Solid State Chem., 171, p. 57. , 29CBA6Pires, M.J.M., Magnus Carvalho G, A., Gama, S., Da Silva, E.C., Coelho, A.A., Mansanares, A.M., (2005) Phys. Rev. B, 72, p. 224435. , PRBMDO 0163-1829 10.1103/PhysRevB.72.224435Gama, S., Alves, C.S., Coelho, A.A., Ribeiro, C.A., Persiano, A.I.C., Silva, D., (2004) J. Magn. Magn. Mater., 272-276, p. 848. , JMMMDC 0304-8853Usenko, N.I., Ivanov, M.I., Berezutski, V.V., Polotska, R.I., (1998) J. Alloys Compd., 266, p. 186. , JALCEU 0925-8388Zipper, E., (1982) J. Phys. F: Met. Phys., 12, p. 3123. , JPFMAT 0305-4608Glaunsinger, W.S., (1976) J. Phys. Chem. Solids, 37, p. 51. , JPCSAW 0022-3697 10.1016/0022-3697(76)90179-7Kaczmarska, K., (1996) J. Alloys Compd., 240, p. 88. , JALCEU 0925-8388Barnes, S.E., (1981) Adv. Phys., 30, p. 801. , ADPHAH 0001-8732 10.1080/00018738100101447Taylor, R.H., Coles, B.R., (1975) J. Phys. F: Met. Phys., 5, p. 121. , JPFMAT 0305-4608 10.1088/0305-4608/5/1/017Kaczmarska, K., Kwapulińska, E., Lebarski, A., Zipper, E., Chelkowski, A., (1985) J. Magn. Magn. Mater., 50, p. 101. , JMMMDC 0304-8853Schütz, G., Knülle, M., Wienke, R., Wilhelm, W., Wagner, W., Kienle, P., Frahm, R., (1988) Z. Phys. B: Condens. Matter, 73, p. 67. , ZPCMDN. 0722-3277. 10.1007/BF01312156Kim, J.W., Lee, Y., Wermeille, D., Sieve, B., Tan, L., Bud'Ko, S.L., Law, S., Goldman, A.I., (2005) Phys. Rev. B, 72, p. 064403. , PRBMDO 0163-1829 10.1103/PhysRevB.72.064403Lee, Y., Kim, J.W., Goldman, A.I., Harmon, B.N., (2005) J. Appl. Phys., 97, pp. 10A311. , JAPIAU 0021-8979 10.1063/1.185221

Het effect van licht op bio-aardappel vergroening in de retail

Uit peilingen van de Nederlandse Aardappel Organisatie en andere, blijkt dat er nog steeds kwaliteitsgebreken vast te stellen zijn bij de biologische aardappels in het schap. Vergroening lijkt één van de belangrijkste aspecten van de kwaliteitsgebreken te zijn. Het doel van dit projectonderdeel is daarom om te onderzoeken welk type licht in de supermarkt leidt tot de beste resultaten om vergroening van bio-aardappels in het schap tegen te gaan

Photoacoustic Monitoring Of Magnetite-crystal Formation From Iron(iii) Hydroxide Acetate: Comparison With Esr Results

The formation of crystalline magnetite by 1-h heat treatment of iron(III) hydroxide acetate is described. This amorphous-crystalline solid transformation is monitored by electron-spin resonance and photoacoustic spectroscopies. No significant changes were detected for samples heated below 190 °C. Above this temperature both techniques presented results following a definite pattern, namely, the enhancement of ion mobility leading to particle growth and crystallization for a temperature up to 240 °C and the onset of magnetic ordering of magnetite near this temperature.65125150515

Thermal Diffusivity And Photoacoustic Spectroscopy Measurements In Cdte Quantum Dots Borosilicate Glasses

In this paper we describe the results of photoacoustic spectroscopy and thermal diffusivity measurements in borosilicate glass matrix with CdTe quantum dots. Samples treated at the temperature of 540°C for different periods were studied. The photoacoustic spectra show the absorption band of CdTe quantum dots, which shifts as a function of the thermal treatment time, revealing the evolution of the average radius of the nanocrystals, Thermal lens measurements provide the thermal diffusivity of the treated samples and give the behavior of the temperature coefficient of the refractive index, dn/dT, which is correlated to the transmittance spectra. © EDP Sciences.125273276Tudury, G.E., Marquezini, M.V., Ferreira, L.G., Barbosa, L.C., Cesar, C.L., (2000) Phys. Rev. B, 62, p. 7357Liu, Y., Reynoso, V.C.S., Barbosa, L.C., Cruz, C.H.B., Cesar, C.L., Fragnito, H.L., Alves, O.L., (1996) J. Mat. Sci. Lett., 15, p. 142Pereira, J.R.D., Mansanares, A.M., Palangana, A.J., Baesso, M.L., (2001) Phys. Rev. E, 64, p. 012701Mansanares, A.M., Baesso, M.L., Da Silva, E.C., Gandra, F.C.G., Vargas, H., Miranda, L.C.M., (1989) Phys. Rev. B, 40, p. 791