Decomposition temperatures of Cu2Ln2O5 (Ln = Tb, Dy, Ho, Er, Tm, Yb, and Lu) compounds

The equilibrium decomposition temperatures of Cu2Ln2O5 (Ln = Tb, Dy, Ho, Er, Tm, Yb, and Lu) compounds have been measured using a combined DTA-TGA apparatus under a flowing Ar + O2 gas mixture, in which the partial pressure of oxygen was controlled at 5.0 × 103 Pa. The Cu2Ln2O5 compounds yield Ln2O3 and Cu2O on decomposition. The decomposition temperature increases monotonically with the atomic number of the lanthanide element. This suggests that the stability of the Cu2Ln2O5 compounds with respect to the component binary oxides increases with decreasing radius of the Ln3+ ion.

Investigation on the High Vacuum Tribological Characteristics of Surface Treated Nuclear Grade Stainless Steel Type AISI 316 LN at 25 to 500 degrees C

Although some researchers have published friction and wear data of Plasma Nitride (PN) coatings, the tribological behavior of PN/PN Pairs in high vacuum environment has not been published so far In order to bridge this knowledge gap, tribological tests under dry conditions have been conducted on PN/PN Pairs for varying temperatures of 25, 200, 400 and 500 degrees C in high vacuum (1.6 x 10(-4) bar) environment. The PN coatings showed good wear resistance layer on the ring surface. The PN coatings were removed only from the pin surface for all the tests since it contacts at a point. The friction and wear were low at lower temperatures and it eliminated adhesion between the contact surfaces until the coating was completely removed from the pin surface. (C) 2011 Journal of Mechanical Engineering. All rights reserved.

Sliding wear behavior of plasma nitrided Austenitic Stainless Steel Type AISI 316LN in the temperature range from 25 to 400 degrees C at 10(-4) bar

There is a research knowledge gap for the dry wear data of nitride treated Stainless Steel in high temperature and high vacuum environment. In order to fill this gap, plasma nitriding was done on austenitic Stainless Steel type AISI 316LN (316LN SS) and dry sliding wear tests have been conducted at 25 degrees C, 200 degrees C and 400 degrees C in high vacuum of 1.6 x 10(-4) bar. The two different slider material (316LN SS and Colmonoy) and two different sliding speeds (0.0576 m/s and 0.167 m/s) have been used. The tribological parameters such as friction coefficient, wear mechanism and volume of metal loss have been evaluated. Scanning Electron Microscopy (SEM) was used to study the surface morphology of the worn pins and rings. Electronic balancing machine was used to record the mass of metal loss during wear tests. The 2D optical profilometer was used to measure the depth of the wear track. The Plasma Nitride treated 316LN SS rings (PN rings) exhibit excellent wear resistance against 316LN SS pin and Colmonoy pin at all temperatures. However, PN ring vs. Colmonoy pin Pair shows better wear resistance than PN ring vs. 316LN SS pin Pair at higher temperature. (C) 2012 Elsevier B.V. All rights reserved.

Synchrotron Small-Angle X-ray Scattering Studies of Hemoglobin Nonaggregation Confined inside Polymer Capsules

The effect of confinement on the structure of hemoglobin (Hb) within polymer capsules was investigated here. Hemoglobin transformed from an aggregated state in solution to a nonaggregated state when confined inside the polymer capsules. This was directly confirmed using synchrotron small-angle X-ray scattering (SAXS) studies. The radius of gyration (R-g) and polydispersity (p) of the proteins in the confined state were smaller compared to those in solution. In fact, the R-g value is very similar to theoretical values obtained using protein structures generated from the Protein Databank. In the temperature range (25-85 degrees C, Tm 59 degrees C), the R-g values for the confined Hb remained constant. This observation is in contrary to the increasing R-g values obtained for the bare Hb in solution. This suggested higher thermal stability of Hb when confined inside the polymer capsule than when in solution. Changes in protein configuration were also reflected in the protein function. Confinement resulted in a beneficial enhancement of the electroactivity of Hb. While Hb in solution showed dominance of the cathodic process (Fe3+ -> Fe2+), efficient reversible Fe3+/Fe2+ redox response is observed in the case of the confined Hb. This has important protein functional implications. Confinement allows the electroactive heme to take up positions favorable for various biochemical activities such as sensing of analytes of various sizes from small to macromolecules and controlled delivery of drugs.

Thermodynamics of TmRhO3, Phase Equilibria, and Chemical Potentials in the System Tm-Rh-O

Phase equilibria in the system Tm-Rh-O at 1200 K is established by isothermal equilibration of selected compositions and phase identification after quenching to room temperature. Six intermetallic phases (Tm3Rh, Tm7Rh3, Tm5Rh3, Tm3Rh2, TmRh, TmRh2 +/-delta) and a ternary oxide TmRhO3 are identified. Based on experimentally determined phase relations, a solid-state electrochemical cell is devised to measure the standard free energy of formation of orthorhombic perovskite TmRhO3 from cubic Tm2O3 and beta-Rh2O3 in the temperature range from (900 to 1300) K. The results can be summarized as: Delta G(f,ox)(o) +/- 104/J.mol(-1) = -46474 + 3.925(T/K). Invoking the Neumann-Kopp rule, the standard enthalpy of formation of TmRhO3 from its constituent elements at 298.15 K is estimated as -1193.89 (+/- 2.86) kJ.mol(-1). The standard entropy of TmRhO3 at 298.15 K is evaluated as 103.8 (+/- 1.6) J.mol(-1).K-1. The oxygen potential-composition diagram and three-dimensional chemical potential diagram at 1200 K and temperature-composition diagrams at constant partial pressures of oxygen are computed from thermodynamic data. The compound TmRhO3 decomposes at 1688 (+/- 2) K in pure oxygen and at 1583 (+/- 2) K in air at standard pressure.

Antibodies against the extracellular domain of human Notch1 receptor reveal the critical role of epidermal-growth-factor-like repeats 25-26 in ligand binding and receptor activation

The Notch signalling pathway is implicated in a wide variety of cellular processes throughout metazoan development. Although the downstream mechanism of Notch signalling has been extensively studied, the details of its ligand-mediated receptor activation are not clearly understood. Although the role of Notch ELRs EGF (epidermal growth factor)-like-repeats] 11-12 in ligand binding is known, recent studies have suggested interactions within different ELRs of the Notch receptor whose significance remains to be understood. Here, we report critical inter-domain interactions between human Notch1 ELRs 21-30 and the ELRs 11-15 that are modulated by calcium. Surface plasmon resonance analysis revealed that the interaction between ELRs 21-30 and ELRs 11-15 is similar to 10-fold stronger than that between ELRs 11-15 and the ligands. Although there was no interaction between Notch 1 ELRs 21-30 and the ligands in vitro, addition of pre-clustered Jagged1Fc resulted in the dissociation of the preformed complex between ELRs 21-30 and 11-15, suggesting that inter-domain interactions compete for ligand binding. Furthermore, the antibodies against ELRs 21-30 inhibited ligand binding to the full-length Notch1 and subsequent receptor activation, with the antibodies against ELRs 25-26 being the most effective. These results suggest that the ELRs 25-26 represent a cryptic ligand-binding site which becomes exposed only upon the presence of the ligand. Thus, using specific antibodies against various domains of the Notch1 receptor, we demonstrate that, although ELRs 11-12 are the principal ligand-binding site, the ELRs 25-26 serve as a secondary binding site and play an important role in receptor activation.

DTM AT 25: ESSAYS ON THEMES AND FUTURE DIRECTIONS

This paper describes the development and evolution of research themes in the Design Theory and Methodology (DTM) conference. Essays containing reflections on the history of DTM, supported by an analysis of session titles and papers winning the ``best paper award'', describe the development of the research themes. A second set of essays describes the evolution of several key research themes. Two broad trends in research themes are evident, with a third one emerging. The topics of the papers in the first decade or so reflect an underlying aim to apply artificial intelligence toward developing systems that could `design'. To do so required understanding how human designers behave, formalizing design processes so that they could be computed, and formalizing representations of design knowledge. The themes in the first DTM conference and the recollections of the DTM founders reflect this underlying aim. The second decade of DTM saw the emergence of product development as an underlying concern and included a growth in a systems view of design. More recently, there appears to be a trend toward design-led innovation, which entails both executing the design process more efficiently and understanding the characteristics of market-leading designs so as to produce engineered products and systems of exceptional levels of quality and customer satisfaction.

Implementación de HyD [Hidroxicolecalciferol (25-OH-D3)] en la dieta de pollos de engorde como profilaxis de osteopatías, enfatizando en el sindrome del hueso negro, Granja Trinidad-1, Tip Top industrial

El objetivo del experimento fue evaluar el efecto del Hidroxicolecalciferol [HyD (25 –OH- D3)] en pollos de engorde, atraves de porcentajes de ceniza, calcio, fosforo y diagnostico de síndrome de hueso negro, se evaluaron dos tratamientos ( HyD y Testigo) con seis repeticiones para cada uno en dos tiempos a los 21 y 35 días de edad en análisis de ceniza, calcio y fosforo para lo cual se extrajo una tibia por pollo, dichos análisis resultaron con diferencias no significativas en ambas edades, las evaluaciones dieron como resultado que de los 21 día a los 35 días disminuyen su valor, ceniza baja de 43.8% a 36.8% en el testigo y de 42.4% a 37.7% en HyD, calcio de 15.6% a 13.4% para el testigo y de 16% a 14.5% para HyD de igual manera para los porcentaje de fosforo de 21 a 35 días con 7.6% a 6.5% para testigo y 7.5% a 6.7% para HyD. A los 35 días los resultados son mayores en el grupo HyD, 37.7% HyD,36.8% testigo en ceniza, calcio 14.5% HyD, testigo 13.4% y fosforo 6.7% HyD , 6.5% para testigo, las diferencias de 21 a 35 días son notorias y conservan la parte proporcional en que los porcentajes estan en ceniza calcio y fosforo, pero estas disminuyen para una misma variable de los 21 días de edad a los 35, sin encontrar diferencia significativas. A los 35 días se realizo análisis de síndrome de hueso negro con un total de 22 repeticiones por tratamiento, la extracción de dicha muestra (tibia) se realizo en planta de proceso, el análisis determino diferencias entre las aves muestreadas dando los mejores resultados aquellas que fueron alimentadas con Hidroxicolecalciferol [HyD (25 –OH- D3)], se observo en los resultados que en el grupo con HyD alcanzo un 91% de individuos sanos superando significativamente al testigo que solo llego a un 77% de individuos sanos, empleando un grado de libertad y 0.05 de significancia, lo que indica diminución de la presencia del síndrome de hueso negro, producto del HyD, empleando la línea genética Cobb 500, y alimentando los pollos del día cero al día 21 con diferencias de tratamiento e igual alimento del día 22 al día 35.

Temperature Dependence of the Tribological Properties of Laser Re-Melted Al-Cu-Fe Quasicrystalline Plasma Sprayed Coatings

The aim of this study was to investigate the effect of temperature on tribological properties of plasma-sprayed Al-Cu-Fe quasicrystal (QC) coating after laser re-melting treatment. The laser treatment resulted in a more uniform, denser and harder microstructure than that of the as-sprayed coatings. Tribological experiments on the coatings were conducted under reciprocating motion at high frequency in the temperature range from 25 to 650 degreesC. Remarkable influence of temperature on the friction behavior of the coating was recorded and analyzed. Microstructural analysis indicated that the wear mechanisms of the re-melted QC coatings changed from abrasive wear at room temperature, to adhesive wear at 400 degreesC and severe adhesive wear at 650 degreesC owing to the material transfer of the counterpart ball. It was also observed that the ratio of the icosahedral (i)-phase to beta-Al-50(Fe,CU)(50) phase in the coating was higher after test at 400 'C than that at 650 'C. The variation of the ratio UP of coating and of the property of the counterpart ball and coating with the temperature are the two main factors influencing the wear mechanisms and value of the friction coefficient.

Letras, 1991-1992, nº 25-26 (número completo)

Contenido: Palabras del Señor Rector / Guillermo P. Blanco – Testimonio / Juan Roberto Courrèges – Historia de un fervor / Teresa Iris Giovacchini – Homenaje / Luis Martínez Cuitiño – Paul Claudel en una de sus “Odas” / Ángel J. Battistessa – Apertura de Nuevos Mundos: 1492-1969 (Documentos igualmente augurales) / Raúl H. Castagnino – Valor condicional de adjetivos con rasgos de predicativos / Hilda Albano de Vázquez – Buzzati, dos en uno / Daniel H. Capano – La estructura circular de “Adán Buenosayres” / Norma Carricaburo – Una constante poética en la producción dramática de Armando Discépolo: continuidad e innovación en el realismo / Jorge Adrián Dubatti – La Saya/Fuga de J. B. o la novela épico-lúdica de un juglar laborioso / Teresa Iris Giovacchini – Algunas notas sobre el didactismo del Libro de Buen Amor / Elsa C. González Bolia – La “Noche oscura”, de San Juan de la Cruz, poema en diálogo / Teresa Herraiz de Tresca – Bernal Díaz del Castillo y las comunicaciones hispano-aztecas / Ernesto Livacic Gazzano – Hacia una teoría borgeana de la recepción / Luis Martínez Cuitiño – El Árbol, el Bosque y John Fowles (A propósito de la reedición de “The tree”) / Rosa E. M. D. Penna – El orden primero recuperado: “Le livre de Christophe Colomb de Paul Claudel / Paulette Rachou – La Torre de Apolidón y el influjo del Libro de Marco Polo en el Amadís de Gaula / Aquilino Suárez Pallasá – Jorge Manrique en la tradición literaria del amor y de la muerte / Lía Noemí Uriarte Rebaudi – Reseñas bibliográficas

O outro e a transcendência : na parábola do Bom Samaritano (Lc 10, 25-37)

Resumen: Neste estudo, procuramos definir o sentido da corporeidade em Entralgo, relacionando-o com o pensamento de Lévinas. Segundo Entralgo, o corpo humano era um microcosmos integrado num cosmos. Assim, o corpo é i único objecto do Universo, do qual temos um duplo conhecimento não de fora, como também temos a sua percepção a partir de dentro. Porém, segundo Lévinas, a corporeidade é a expressão do Rosto do Outro, referindo- se como uma prefiguração do Outro, que tem o seu epílogo na parábola do Bom Samaritano. Há, na verdade, uma relação de aproximação antropológica entre o sentido do corpo como forma de manifestar o Outro. Em ti e por ti, tu eras uma pessoa, mas sendo tu uma pessoa, podendo e devendo Eu ver-te e tratar-te como tal pessoa. Os dois pensadores apresentam uma referência em relação à pessoas. Segundo Lévinas a pessoa será responsabilidade.