Si and SixGe1-x NWs studied by Raman spectroscopy

Group IV nanostructures have attracted a great deal of attention because of their potential applications in optoelectronics and nanodevices. Raman spectroscopy has been extensively used to characterize nanostructures since it provides non destructive information about their size, by the adequate modeling of the phonon confinement effect. The Raman spectrum is also sensitive to other factors, as stress and temperature, which can mix with the size effects borrowing the interpretation of the Raman spectrum. We present herein an analysis of the Raman spectra obtained for Si and SiGe nanowires; the influence of the excitation conditions and the heat dissipation media are discussed in order to optimize the experimental conditions for reliable spectra acquisition and interpretation.

A DIALÉTICA ENTRE O CONHECIMENTO DE SI E O CONHECIMENTO DE DEUS NO LIVRO X DAS CONFISSÕES DE SANTO AGOSTINHO

O conhecimento de si e o conhecimento de Deus estabelecem uma relação fundamental na obra mais conhecida de Agostinho, Confissões. O livro X das Confissões contém as narrativas centrais para a análise da dialética entre o conhecimento de si e o conhecimento de Deus, que tem como chave de leitura a memória para a constituição do cogito existencial. É examinada a relação que existe, no texto narrativo de Agostinho, entre a interpretação da Escritura e a constituição do si, em que há aspectos do discurso interior e abordagem no quadro da teoria narrativa que é dada a partir do conceito de identidade narrativa. A constituição do si é desenvolvida na dialética interna do personagem entre a afirmação de si e a negação de si, que apresenta a imanência do homem como característica pessoal e, ao mesmo tempo, o desejo de transcendência daquilo que o ser humano tem de mais íntimo em relação a Deus. Esta é uma análise da tensão existente entre a visão que o ser humano tem da consciência de si e a que ele tem de Deus, na busca pela felicidade.(AU)

A DIALÉTICA ENTRE O CONHECIMENTO DE SI E O CONHECIMENTO DE DEUS NO LIVRO X DAS CONFISSÕES DE SANTO AGOSTINHO

O conhecimento de si e o conhecimento de Deus estabelecem uma relação fundamental na obra mais conhecida de Agostinho, Confissões. O livro X das Confissões contém as narrativas centrais para a análise da dialética entre o conhecimento de si e o conhecimento de Deus, que tem como chave de leitura a memória para a constituição do cogito existencial. É examinada a relação que existe, no texto narrativo de Agostinho, entre a interpretação da Escritura e a constituição do si, em que há aspectos do discurso interior e abordagem no quadro da teoria narrativa que é dada a partir do conceito de identidade narrativa. A constituição do si é desenvolvida na dialética interna do personagem entre a afirmação de si e a negação de si, que apresenta a imanência do homem como característica pessoal e, ao mesmo tempo, o desejo de transcendência daquilo que o ser humano tem de mais íntimo em relação a Deus. Esta é uma análise da tensão existente entre a visão que o ser humano tem da consciência de si e a que ele tem de Deus, na busca pela felicidade.(AU)

Self-standing curved crystals for X and Gamma rays focusing

The efficiency of a Laue lens for X and Gamma ray focusing in the energy range 60 ÷ 600 keV is closely linked to the diffraction efficiency of the single crystals composing the lens. A powerful focusing system is crucial for applications like medical imaging and X ray astronomy where wide beams must be focused. Mosaic crystals with a high density, such as Cu or Au, and bent crystals with curved diffracting planes (CDP) are considered for the realization of a focusing system for X rays, owing to their high diffraction efficiency. In this work, a comparison of the efficiency of CDP crystals and mosaic crystals was performed on the basis of the theory of X-ray diffraction. Si, GaAs and Ge CDP crystals with optimized thicknesses and moderate radii of curvature of several tens of metres demonstrate comparable or superior performance with respect to the higher atomic number mosaic crystals generally used. A simplified approach for calculating the integrated reflectivity of the crystals is applied. A bending technique used during this work to realize CDP crystals consists in a controlled surface damaging induced by a mechanical lapping process. A compressive strained layer of few micrometres in thickness is generated and causes the convex curvature of the damaged side of the crystal. Another new bending technique is developed and the main results are shown. The process consists on a film deposition of a selected bi-component epoxy resin on one side of crystal, made uniform in thickness by mean of a spin-coater. Choosing the speed of spin-coating, so changing the thickness of the film, a control of radius of curvature can be obtained. Moreover the possibility to combine the two bending technique to obtain CDP crystal with a stronger curvature in rather thick crystals was demonstrated. Detailed characterization of Si, and GaAs CDP crystals at low and high x-ray energies are performed on flat and bent crystals obtained with the damaging and the resin deposition technique. As expected an increase of diffraction efficiency in asymmetrical diffraction geometry in CDP crystals with respect to the flat ones is observed. On the other hand an unexpected increase of the integrated intensity in symmetrical geometry, not predicted by the theory, is observed in all the measurements performed with different set up. The experimental trend of the integrated reflectivity as a function of the radius of curvature is in a good agreement with that predicted by the theory of bent perfect crystals, so it is possible to conclude that the surface damage has a limited effect on the crystal reflectivity. A study of the integrated reflectivity in the energy range of interest (100÷350 keV) in CDP crystals realized with damaging and resin deposition technique at symmetrical and asymmetrical geometries was performed at ILL Institute. Also at these energies the diffraction efficiency of bent crystals was much larger (a 12 time increase is observed for bent crystals in asymmetrical 111 geometry) than that measured in flat crystals. The diffraction efficiency of CDP crystals realized with both techniques tends to coincide with that of flat crystals at very high energies (> 200 keV). This suggesting that also real flat perfect crystals can be considered as strongly bent or mosaic crystals at very high X ray energies.

X-ray absorption study of the ferromagnetic Cu moment at the YBa_(2)Cu_(3)O_(7)/La_(2/3)Ca_(1/3)MnO_(3) interface and variation of its exchange interaction with the Mn moment

With x-ray absorption spectroscopy and polarized neutron reflectometry we studied how the magnetic proximity effect at the interface between the cuprate high-TC superconductor YBa_(2)Cu_(3)O_(7) (YBCO) and the ferromagnet La_(2/3)Ca_(1/3)MnO_(3) (LCMO) is related to the electronic and magnetic properties of the LCMO layers. In particular, we explored how the magnitude of the ferromagnetic Cu moment on the YBCO side depends on the strength of the antiferromagnetic (AF) exchange coupling with the Mn moment on the LCMO side. We found that the Cu moment remains sizable if the AF coupling with the Mn moments is strongly reduced or even entirely suppressed. The ferromagnetic order of the Cu moments thus seems to be intrinsic to the interfacial CuO_(2) planes and related to a weakly ferromagnetic intraplanar exchange interaction. The latter is discussed in terms of the partial occupation of the Cu 3d_(3z^(2)−r^(2)) orbitals, which occurs in the context of the so-called orbital reconstruction of the interfacial Cu ions.

Preclarissimum mathematicaru[m] opus : in quo contine[n]tur perspicacissimi mathematici thome Brauardini arismetica [et] eiusde[m] geometria : necno[n] et sapientissimi Pisani carturiensis perspectiua q[ue] ?coi[n]si[n]scribi[n]t? : cu[m] acutissimis io?[n]nis d'assia sup[er] eade[m] persp[er]tiua questionibus annexis vna cum figuris omnib[us] vnicuiq[ue] op[er]i req[ui]sitis /

Martín Abad. Post-incunables,

Etymologicum magnum Romaniæ. Dicționarul limbei istorice si poporane a Românilor lucrat după dorința și cu ch̀eltuiéla M.S. regelui Carol I sub auspiciele Academiei romane de B. Petriceĭcu-Hasdeu ...

Vol. 3- have imprint: Bucuresci, Stab. grafic I.V. SocecÅ­.

Dell' historia ecclesiastica di Piacenza di Pietro Maria Campi canonico Piacentino parte prima [-terza] : nella quale si spiegano le attioni de' santi, de' beati, e de' vescoui della città di Piacenza, e l'antichissima immunità , e giurisditione di quella chiesa, con le fondationi di molti luoghi sacri, et insieme le varie donationi, e gratie riportate da' sommi pontefici, imperadori, rè, e principi, e si fà anche mentione di molte famiglie, huomini illustri, e maggiori successi d'Italia : con l'origine de' nomi de' villaggi, terre, e castella del Piacentino ... e nel fine vn' Apologia del medesimo autore per l'innocente, e santa vita del B. Gregorio papa X. Piacentino, e la vita Latina antichissima dello stesso pontefice non mai più vscita in luce ... ; Parte seconda.

Mode of access: Internet.

De la pirotechnia. Libri X. : doue ampiamente si tratta non solo di ogni sorte & diuersita di miniere, ma anchora quanto si ricerca intorno a la prattica di quelle cose di quel che si appartiene a l'arte de la fusione ouer gitto de metalli come d'ogni altra cosa simile a questa /

CCBE S. XVI,

Unit maintenance repair parts and special tools lists : loader, scoop type, DED, 4 x 4, articulated frame steer, 4 1/2 to 5 cu. yd., (CCE), Army model H100C RB, type I with 4 1/2 cu. yd. rock bucket, NSN 3805-01-052-9042, Army model H100C GPB, type II with 5 cu. yd. general purpose bucket, NSN 3805-01-052-9043.

Includes indexes.

Unit maintenance repair parts and special tools list : loader, scoop type, DED 4 x 4, articulated frame steer, 4 1/2 to 5 cu. yd., (CCE), with 4 1/2 cu. yd. rock bucket, NSN 3805-00-602-5006, Clark model 175B, type I and with 5 cu. yd. general purpose bucket, NSN 3805-00-602-5013 Clark model 175B, type II.

Includes indexes.

Intermediate direct support and intermediate general support maintenance repair parts and special tools lists ... : loader, scoop type, DED, 4 x 4, articulated, frame steer, 4 1/2 to 5 cu. yd., (CCE), Army model H100C RB, type I with 4 1/2 cu. yd. rock bucket ....

"October 1988."

Organizational maintenance repair parts and special tools list : crane, shovel, truck mounted, 20 ton, 3/4 cu yd., GED 6 x 6, NSN 3810-00-861-8088, Harnischfeger model M320T.

Includes index.