Caracterización físico-químicamente de huevos de Iguana iguana. Las pruebas físicas se realizaron por métodos de Espectrofotocolorimetría, calibrador, cinta métrica, micrómetro, flexómetro y ...flotación y las pruebas químicas acorde a los lineamientos exigidos por la A.O.A.C. Los resultados obtenidos mostraron con respecto a las características físicas: En promedio, un peso de 14,78 (g); diámetro longitudinal 39,70 mm (±0,49), diámetro transversal 26,41mm (±0,6), largo perimetral 11,55 cm (±0,2), ancho perimetral 9,07 cm (± 0,2), entre otras caractericticas evaluadas. Respecto a la composición química, en cáscara 51,23% (±3,02) Calcio Inorgánico; 20,17% (±1,56) Fósforo Inorgánico; en albumen 51,47% (±1,05) de proteína bruta, un 17,02% (±1,33) de grasa cruda y en albumen compacto un peso de 3,83 g (±0,21). Mediante regresiones múltiples se determinó que el peso depende del porcentaje de cáscara y del albumen compacto en un 87%. La gravedad específica depende no solo del largo perimetral sino también del porcentaje de cáscara y del grosor de ésta en la zona ecuatorial en un 86,3%. El porcentaje de cáscara, del peso, gravedad específica y grosor en la zona ecuatorial en 88,3%. La caracterización cromática determinó su color entre amarillo medio y blanco amarillento.
The shock-induced transition from graphite to diamond has been of great scientific and technological interest since the discovery of microscopic diamonds in remnants of explosively driven graphite. ...Furthermore, shock synthesis of diamond and lonsdaleite, a speculative hexagonal carbon polymorph with unique hardness, is expected to happen during violent meteor impacts. Here, we show unprecedented in situ X-ray diffraction measurements of diamond formation on nanosecond timescales by shock compression of pyrolytic as well as polycrystalline graphite to pressures from 19 GPa up to 228 GPa. While we observe the transition to diamond starting at 50 GPa for both pyrolytic and polycrystalline graphite, we also record the direct formation of lonsdaleite above 170 GPa for pyrolytic samples only. Our experiment provides new insights into the processes of the shock-induced transition from graphite to diamond and uniquely resolves the dynamics that explain the main natural occurrence of the lonsdaleite crystal structure being close to meteor impact sites.
This paper presents a static analysis of functionally graded plates (FGPs) by using a new first shear deformation theory (FSDT). This theory contains only four unknowns, with is even less than the ...classical FSDT. In this paper a simply supported FG square sandwich plate is subjected to a bi-sinusoidal load. The governing equations for static bending analysis are derived by employing the principle of virtual works. These equations are then solved via Navier-type, closed form solutions. The accuracy of the present theory is ascertained by comparing it with various available solutions in the literature.
•This paper presents a refined first shear deformation theory (FSDT).•This theory contains only four unknowns, with is even less than the classical FSDT.•This paper presents the bending analysis of functionally graded sandwich plates.•The present theory presents good accuracy when comparing it with various available solutions in the literature.
This paper presents a thermoelastic bending analysis of functionally graded sandwich plates by using a new quasi-3D hybrid type higher order shear deformation theory (HSDT). The mathematical model ...contains only 5 unknowns as the first order shear deformation theory (FSDT). The nonlinear term of the temperature field is modeled in such way that can be different from the shape functions of the displacement field. The mechanical properties of functionally graded layers of the plate are assumed to vary in the thickness direction according to a power law distribution. The governing equations for the thermoelastic bending analysis are obtained through the principle of virtual work and solved via Navier-type solution. Results reveal: (a) the good performance of the present generalized formulation; (b) the significant influence of the nonlinear temperature field on the displacements and stresses results. Consequently, discussion on nonlinear temperature field influences should be further considered in the literature.
Time-resolved x-ray diffraction (XRD) of compressed liquid water shows transformation to ice VII in 6 nsec, revealing crystallization rather than amorphous solidification during compression freezing. ...Application of classical nucleation theory indicates heterogeneous nucleation and one-dimensional (e.g., needlelike) growth. These first XRD data demonstrate rapid growth kinetics of ice VII with implications for fundamental physics of diffusion-mediated crystallization and thermodynamic modeling of collision or impact events on ice-rich planetary bodies.
Abstract Mutations in PIK3R1 gene have been associated to two different conditions: a primary immunodeficiency, called APDS2, of recent description and SHORT syndrome. 47 patients with APDS2 have ...been reported to date, only one of them sharing both PIK3R1 -related phenotypes. Here we describe two more patients affected by APDS2 and SHORT syndrome, which highlights that this association may not be so infrequent. We recommend that patients with mutations in PIK3R1 gene should be assessed by both clinical immunologists and clinical geneticists.
Ultrafast x-ray diffraction at the LCLS x-ray free electron laser has been used to resolve the structural behavior of antimony under shock compression to 59 GPa. Antimony is seen to transform to the ...incommensurate, host-guest phase Sb-II at ∼11 GPa, which forms on nanosecond timescales with ordered guest-atom chains. The high-pressure bcc phase Sb-III is observed above ∼15 GPa, some 8 GPa lower than in static compression studies, and mixed Sb-III/liquid diffraction are obtained between 38 and 59 GPa. An additional phase which does not exist under static compression, Sb-I^{'}, is also observed between 8 and 12 GPa, beyond the normal stability field of Sb-I, and resembles Sb-I with a resolved Peierls distortion. The incommensurate Sb-II high-pressure phase can be recovered metastably on release to ambient pressure, where it is stable for more than 10 ns.
PDF
