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1.
V. Recarte R. B. Pérez-Sáez J. San Juan E. H. Bocanegra M. L. Nó 《Metallurgical and Materials Transactions A》2002,33(8):2581-2591
The martensitic transformation temperatures and the types of martensitic phases have been determined in a wide concentration
range of technological interest for Cu-Al-Ni shape-memory alloys (SMAs) A stability diagram of martensitic phases as a function
of alloy concentration has been determined. It is found that when the aluminum content increases, the transformation changes
from β
3 ⇒ β′3 to β
3 ⇒ γ′3, with an intermediate concentration range where both martensites coexist due to a β
3 ⇒ γ′3+β′3 transformation. On the other hand, an increase of nickel content stabilizes the martensite β′3, changing from a mixed β
3 ⇒ γ′3 + β′3 to a single β
3 ⇒ β′3 transformation. Furthermore, linear relationships between M
s
and Al and Ni concentrations have been obtained for all types of martensitic phases. 相似文献
2.
TS Bocanegra AL Weaver EA Tindall DH Sikes JA Ball CB Wallemark GS Geis JG Fort 《Canadian Metallurgical Quarterly》1998,25(8):1602-1611
3.
A study about the performance of Pt(0.3 wt%)Sn(0.3 wt%) catalysts supported on different materials in n-butane dehydrogenation is reported in this paper. The materials used as supports were γ-Al2O3, ZnAl2O4 spinel, MgAl2O4 spinel and spheres of α-Al2O3 with a washcoating of γ-Al2O3. The syntheses of both spinels leaded to very pure ZnAl2O4 and MgAl2O4 supports. The material prepared by washcoating showed the presence of an uniform and homogeneous layer of γ-Al2O3 (with a thickness between 12 and 18 μm) deposited on the spheres of α-Al2O3.The best behavior in activity, selectivity and stability through five severe cycles was achieved by bimetallic PtSn catalysts supported on MgAl2O4 spinel and on the material prepared by washcoating. The very good performance of these catalysts through the different cycles of reaction-regeneration can be due to the presence of metallic phases which preserve the strong intermetallic interaction along the different treatments, thus avoiding segregation processes. 相似文献
4.
Rodrigo Bocanegra Anikumar G. Gaonkar Antonio Barrero Ignacio G. Loscertales David Pechack Manuel Marquez 《Journal of food science》2005,70(8):e492-e497
An experimental approach to the production of cocoa butter microcapsules containing an aqueous solution or an oil‐in‐water emulsion via electrified coaxial jets is presented here. Recently, a new method to generate nano‐micrometric coaxial jets has been reported. These coaxial jets are generated by electrohydrodynamic forces with diameters that range from hundreds of nanometers to tens of microns. The controlled break‐up of the jets gives rise to an aerosol of compound droplets in which an outer liquid coats an inner one. This technique has turned out to be an effective method to encapsulate aqueous‐based food ingredients such as flavors, aromas, enzymes, salts, minerals, and vitamins in the micrometric range with relatively high monodispersity and controllable geometrical parameters of the capsules such as thickness of the shell or number of inner cores in the capsules. 相似文献
5.
R. Bocanegra D. Galn M. Mrquez I.G. Loscertales A. Barrero 《Journal of aerosol science》2005,36(12):629-1399
Orifices instead of needle capillaries can be used for electrospraying liquids in steady cone-jet mode. This novel device has been used for multiplexing cone-jet menisci anchored at the rim of orifices drilled on a slide. The stability and reliability of the electrospraying process from holes improve substantially when orifices are drilled in dielectric materials with hydrophobic surfaces. The manufacturing process of high compactness multi-electrospray atomizers becomes much easier and cheaper if holes instead of needles are used as emitters. Very cheap multi-hole electrospray atomizers, bearing up to 37 holes and with a compactness of up to 115 emitters per square centimeter, have been home-made and successfully operated. The current and droplet size distribution of the spray issued from these atomizers agreed quite well with those issued from a single source of electrospray, provided that the same flow rate was being electrosprayed throughout each one of the orifices of the multi-injector, and that this value was equal to that issued from the single electrospray source. 相似文献
6.
HM Al-Abdely JR Graybill R Bocanegra L Najvar E Montalbo SL Regen PC Melby 《Canadian Metallurgical Quarterly》1998,42(10):2542-2548
Carcass measurements of 12th-rib fat thickness (CARCFAT), longissimus muscle area (CARCLMA), and weight (CARCWT) on 2,028 Brangus and Brangus-sired fed steers and heifers, as well as yearling weights (YWT) and ultrasound measures of 12th-rib fat thickness (USFAT) and longissimus muscle area (USLMA) on 3,583 Brangus bulls and heifers were analyzed to estimate genetic parameters. Data were analyzed using a six-trait animal model and an average information REML algorithm. The model included fixed effects for contemporary group and breed of dam, covariates for age at slaughter or measurement, and random animal and residual effects. Heritabilities for CARCFAT, CARCLMA, CARCWT, USFAT, USLMA, and YWT were .27+/-.05, .39+/-.05, .59+/-.06, .11+/-.03, .29+/-.04, and .40+/-.04, respectively. Genetic correlations between CARCFAT and USFAT, CARCLMA and USLMA, and CARCWT and YWT were .69+/-.18, .66+/-.14, and .61+/-.11, respectively. The favorable and moderately strong genetic correlations between carcass measurements and similar yearling breeding-animal ultrasound measurements indicate that such measurements of 12th-rib fat and longissimus muscle area are useful in predicting genetic values for carcass leanness and longissimus muscle area. Selection using yearling ultrasound measurements of breeding cattle should result in predictable genetic improvement for carcass characteristics. Inclusion of yearling ultrasound measurements for fat thickness and longissimus muscle area should enhance national cattle evaluation programs. 相似文献
7.
High Temperature phase transitions in long chain (CnH2n+1NH3)2CuCl2Br2-compounds (n ≥ 10) were detected for the first time by means of calorimetric measurements. Although the experimental data reveal a complex phase transition sequence a first phenomenological approach is attempted. 相似文献
8.
Spontaneous deformation of the BaTiO3 crystals doped with Co has been investigated as a function of both temperature and at. % Co present in the samples. The experimental results show a diffuse character of the transition as a function of the Co concentration. Interpretation of the thermal expansion behaviour seems possible by assuming a random distribution of Co in the sample and a weakness of TiO bonds as a function of Co concentration. 相似文献
9.
A. Aguilar‐Elguézabal M. H. Bocanegra‐Bernal 《International Journal of Applied Ceramic Technology》2013,10(2):215-223
We investigated the Vickers hardness and fracture toughness of an Al2O3(n) + 70 wt% ZrO2 (TZ‐3Y)n nanocomposite with addition of 2.5 wt% Al2O3 whiskers. Densities greater than 95% were reached after conventional sintering at 1500°C. The fracture toughness was increased 62% over pure Al2O3. Microcracking and crack deflection can be the mechanisms responsible to improve the fracture toughness. The use of ATZ composites with a low percent of whiskers can be a promising biomedical material for medical and dental applications given its large increase in fracture toughness over pure alumina and the observed relief from aging issues of zirconia. 相似文献
10.
AC Carvalho JF Lima AC Soares SL Lopes CM Silva J Bocanegra 《Canadian Metallurgical Quarterly》1994,63(2):117-119
A two-year-old male child presenting anomalous origin of the left coronary artery diagnosed by Doppler echocardiography and confirmed by angiography developed an ischemic stroke, which is a rare event in this situation. He [correction of She] had good recovery of the neurological deficit and his anomalous artery was successfully reimplanted. 相似文献