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  • 1
    Electronic Resource
    Electronic Resource
    Efficiency and thermal stability of Pt gettering in crystalline Si (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 4322-4327 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated the efficiency and the thermal stability of Pt gettering at different sites in crystalline Si. In particular, we compared the gettering performances of heavily n-type doped regions formed by P diffusion, cavities formed after high-temperature annealings of He implanted Si, and damage induced by ion implantation of B, C, or Si. These sites were introduced on one side of wafers containing a uniform Pt concentration in the range 1×1013–5×1014 atoms/cm3. The uniform concentration of Pt was attained by means of Pt implantation followed by a high-temperature thermal process. The gettering efficiency of the different sites was monitored during thermal processes at 700 °C for times ranging from 1 to 48 h. Thermal stability of gettering was investigated with a subsequent thermal process in the temperature range 750–900 °C during which part of the gettered Pt is released in the bulk of the wafer. The kinetics of Pt gettering at the different sites is found to be similar since it is fully dominated by the kick-out diffusion mechanism of the metal impurity. The thermal stability is instead site-dependent and can be described in terms of an effective binding enthalpy of 1.9, 2.6, and 3.0 eV between Pt atoms and cavities, P-doped region, and ion-implantation damage, respectively. The physical meaning of the binding enthalpy is investigated and discussed. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363381
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  • 2
    Electronic Resource
    Electronic Resource
    Kinetics and thermodynamics constraints in Pt gettering by P diffusion in Si (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 161-166 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have explored the mechanisms underlying the gettering of Pt atoms dissolved in crystalline Si. By using Pt implantation at different fluences followed by a thermal process at 970 °C for 5 h we were able to prepare crystalline silicon wafers containing a uniform Pt concentration in the range 2×1012–2×1014 atoms/cm3. Subsequently, a heavily doped n-type region was produced on one side of the wafer by P diffusion at 900 °C. Following this deposition process we have studied the kinetics of Pt gettering to the P-doped region in the temperature range 700–970 °C and for annealing times ranging from 30 min to 48 h. Lifetime measurements by means of a contactless technique were used to detect the depletion of Pt in the bulk of the wafer due to the gettering process. The large range of initial Pt concentrations that we have explored allowed us to identify and separate the kinetics and thermodynamics constraints that determine the gettering efficiency and to propose a phenomenological model for the gettering of Pt. In particular, it has been found that the kinetics of the gettering process are driven by the dissolution of immobile substitutional Pt atoms into interstitial sites. This process is assisted by Si self-interstitials and characterized by an activation energy of 0.4 eV. Moreover, the equilibrium distribution of Pt is thermodynamically determined by a segregation coefficient of the Pt atoms between the gettering sites and the silicon matrix. This segregation coefficient, and hence the gettering efficiency, decrease when the temperature of the gettering process is increased and is described by an activation energy of 2.5 eV. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.362800
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  • 3
    Electronic Resource
    Electronic Resource
    Reaction of aziridines with benzoic anhydride (1968)
    s.l. : American Chemical Society
    The @journal of organic chemistry 33 (1968), S. 3344-3346 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo01272a079
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  • 4
    Electronic Resource
    Electronic Resource
    In situ diagnostics of pulsed laser deposition of ferroelectric Pb(Ti0.48Zr0.52)O3 on Si (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 1194-1196 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The transport of material from target to substrate has been monitored in the pulsed laser deposition of Pb(Ti0.48Zr0.52)O3 films on p-doped Si(100) using two in situ diagnostics, namely plume fluorescence spectroscopy and plume ion mass spectrometry. The as-grown PZT films are specular, with thicknesses which decrease from 350 to 250 nm on a radius 5 mm from the center and show a dielectric hysteresis with typical remanent polarizations and coercive fields of 0.2 μC/cm2 and 124 kV/cm, respectively. The analysis of the plume fluorescence emission and ionic yield indicates that oxidation of the ablated material occurs during transport from target to substrate and that, in order to grow ferroelectric thin films, the substrate should be located in the region of the plume where the relative concentrations of metal oxides and clusters increase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.109768
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  • 5
    Electronic Resource
    Electronic Resource
    Tear gas dermatitis (2005)
    Oxford, UK : Blackwell Science Ltd
    Clinical and experimental dermatology 30 (2005), S. 0 
    Details
    ISSN: 1365-2230
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2230.2005.01801.x
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  • 6
    Electronic Resource
    Electronic Resource
    A case of loiasis in Rome (2002)
    Oxford, UK : Blackwell Science Ltd
    Journal of the European Academy of Dermatology and Venereology 16 (2002), S. 0 
    Details
    ISSN: 1468-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background  Owing to the increase of an immigrant population and of Italian citizens travelling for tourism or on business, it is nowadays possible to observe clinical pictures characteristic of tropical regions, often with indistinct symptoms. One of these is Loa loa infestation, or loiasis, a form of filariasis caused by Loa loa and transmitted by the Chrysops fly. We present the case of a male immigrant from Cameroon. Characteristic symptoms were intense xerosis, mostly of the third inferior part of the legs, intensely pruritic, with numerous lesions from scratching. No benefit was obtained by emollient topics, anti-acarus and systemic antihistamines.Method  Serum samples and Giemsa, haematoxylin, haematoxylin + Giemsa concentration-on-membrane stains, have evidenced the presence of Loa loa microfilariae.Results  A diagnosis for L. loa (loiasis) infestation was made.Conclusions  At the beginning of the migration phenomenon, particularly from Africa, Italian physicians, especially dermatologists, were eagerly looking for ‘tropical’ diseases; this approach can be defined as ‘Salgari's syndrome’ from the name of the Italian novelist who, though never travelling out of Italy, had perfectly described environments and habits typical of far away countries. Now, conversely, we have to avoid the opposite approach of considering real tropical diseases as related to social or psychological difficult conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1468-3083.2002.00438.x
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  • 7
    Electronic Resource
    Electronic Resource
    Turbulent motions in molecular clouds (1985)
    Springer
    Astrophysics and space science 111 (1985), S. 343-354 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have studied the behavior of the inner motions of OH, H2CO, and CO molecular clouds. This study shows the existence of two main components of these clouds: the narrow one, associated to dense small clouds and a wide one ‘representing’ the large diffuse clouds seen in neutral hydrogen, the large clouds are the ‘vortex’ and intermediate state between turbulent and hydrodynamic motions in the Galaxy. For the dense clouds with sizesd〈10 pc we have found a relationship σ∝d 0.38 consistent with the Kolmogorov law of turbulence; the densities and sizes of these clouds behave asn∝d −1. This last relation for these molecular clouds is compared with theHII one. Also, we discuss the effects of the inner magnetic field in these clouds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00649974
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  • 8
    Electronic Resource
    Electronic Resource
    Velocity gradients perpendicular to the galactic plane in the solar vicinity (1987)
    Springer
    Astrophysics and space science 129 (1987), S. 107-122 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract One of the most important topics in astrophysics concern to the study of how the stars are born. Observational facts show that nearly all stars were born in groups within large massive complexes of gas and dust. An idea almost universally accepted, comes from the fact that gas associated with star formation is very inhomogeneous over a large range of size scales. The stars need to be formed by the fragmentation of large gas complexes. Studies of the interstellar medium show the existence of a hierarchical structure covering at least four orders of magnitude in density and length scale. Recently various studies have been made in an attempt to understand the process, or processes, responsible for the decay of large scales to small ones. Several processes have been suggested, however, some of them seem to be responsible only for generating the hierarchical structure on small scales. A study of the velocity distribution of molecular clouds in the solar vicinity, shows the existence of large velocity gradients perpendicular to the galactic plane. As can be shown, these gradients may be one of the most important sources of the energy responsible for the production of the interstellar turbulence on the largest size scales.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00717861
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  • 9
    Electronic Resource
    Electronic Resource
    Local kinematics of OB stars (1983)
    Springer
    Astrophysics and space science 96 (1983), S. 195-203 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Analysis of observational data of OB stars show an, excellent agreement of the density distributions in space ϱ(x, y, z) as well as in velocity space $$\rho (\dot x,\dot y,\dot z)$$ with the predictions of the density wave theory, the values for the density and velocity fluctuations are explained only by the non-linear theory. These theoretical calculations predict perturbations greater than ±10 km s−1, consistent with the observations for the velocity field. Thus one should disregard analytical treatments of the linearized equations since they predict maximum perturbations of ±5km s−1. Another consequence of this is the fact that the Gould's Belt is not a local anomaly, but a local feature of the density waves. The analysis of observational data show that the wave pattern is similar to that of the gas and dust.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00661953
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  • 10
    Electronic Resource
    Electronic Resource
    Geographic Differences in Bone Mineral Density of Mexican Women (2000)
    Springer
    Osteoporosis international 11 (2000), S. 562-569 
    Details
    ISSN: 1433-2965
    Keywords: Key words:Bone mineral density (BMD) – Dual-energy X-ray absorptiometry (DXA) – Femoral neck – Hispanic – Lumbar spine – Mexican women
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract: The aim of this study was to generate standard curves for normal spinal and femoral neck bone mineral density (BMD) in Mexican women using dual-energy X-ray absorptiometry (DXA), to analyze geographic differences and to compare these with “Hispanic” reference data to determine its applicability. This was a cross-sectional study of 4460 urban, clinically normal, Mexican women, aged 20–90 years, from 10 different cities in Mexico (5 in the north, 4 in the center and 1 in the southeast) with densitometry centers. Women with suspected medical conditions or who had used drugs affecting bone metabolism, were excluded. Lumbar spine BMD was significantly higher (1.089 ± 0.18 g/cm2) in women from the northern part of Mexico, with intermediate values in the center (1.065 ± 0.17 g/cm2) and lower values (1.013 ± 0.19 g/cm2) in the southeast (p〈0.0001). Similarly, femoral neck BMD was significantly higher in women from the north (0.895 ± 0.14 g/cm2), intermediate in the center (0.864 ± 0.14 g/cm2) and lower (0.844 ± 0.14 g/cm2) in the southeast part of Mexico (p〈0.0001). Northern Mexican women tend to be taller and heavier than women from the center and, even more, than those from the southeast of Mexico (p〈0.0001). However, these differences in BMD remained significant after adjustment for weight (p〈0.0001). A significant loss (p〈0.0001) in BMD was observed from 40 to 69 years of age at the lumbar spine and up to the eighth decade at the femoral neck. Higher and lower lumbar spine values, as compared with the “Hispanic” population, were observed in Mexican mestizo women from the northern and southeastern regions, respectively. In conclusion, there are geographic differences in weight and height of Mexican women, and in BMD despite adjustment for weight.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001980070076
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