The influence of temperature gradient and lowering speed on the melt-solid interface shape of GaxIn1-xSb alloy crystals grown by vertical Bridgman technique

Radially homogeneous bulk alloys of GaxIn1-xSb in the range 0.7 < x < 0.8, have been grown by vertical Bridgman technique. The factors affecting the interface shape during the growth were optimised to achieve zero convexity. From a series of experiments, a critical ratio of the temperature gradient (G) of the furnace at the melting point of the melt composition to the ampoule lowering speed (v) was deduced for attaining the planarity of the melt-solid interface. The studies carried out on directional solidification of Ga0.77In0.23Sb mixed crystals employing planar melt-solid interface exhibited superior quality than those with nonplanar interfaces. The solutions to certain problems encountered during the synthesis and growth of the compound were discussed. (C) 1999 Elsevier Science B.V. All rights reserved.

A strategy-proof and budget-balanced mechanism for carbon footprint reduction by global companies

The problem addressed in this paper is concerned with an important issue faced by any green aware global company to keep its emissions within a prescribed cap. The specific problem is to allocate carbon reductions to its different divisions and supply chain partners in achieving a required target of reductions in its carbon reduction program. The problem becomes a challenging one since the divisions and supply chain partners, being autonomous, may exhibit strategic behavior. We use a standard mechanism design approach to solve this problem. While designing a mechanism for the emission reduction allocation problem, the key properties that need to be satisfied are dominant strategy incentive compatibility (DSIC) (also called strategy-proofness), strict budget balance (SBB), and allocative efficiency (AE). Mechanism design theory has shown that it is not possible to achieve the above three properties simultaneously. In the literature, a mechanism that satisfies DSIC and AE has recently been proposed in this context, keeping the budget imbalance minimal. Motivated by the observation that SBB is an important requirement, in this paper, we propose a mechanism that satisfies DSIC and SBB with slight compromise in allocative efficiency. Our experimentation with a stylized case study shows that the proposed mechanism performs satisfactorily and provides an attractive alternative mechanism for carbon footprint reduction by global companies.

Zero miss distance guidance using feedforward and periodic control

There have been attempts at obtaining robust guidance laws to ensure zero miss distance (ZMD) for interceptors with parametric uncertainties. All these laws require the plant to be of minimum phase type to enable the overall guidance loop transfer function to satisfy strict positive realness (SPR). The SPR property implies absolute stability of the closed loop system, and has been shown in the literature to lead to ZMD because it avoids saturation of lateral acceleration. In these works higher order interceptors are reduced to lower order equivalent models for which control laws are designed to ensure ZMD. However, it has also been shown that when the original system with right half plane (RHP) zeros is considered, the resulting miss distances, using such strategies, can be quite high. In this paper, an alternative approach using the circle criterion establishes the conditions for absolute stability of the guidance loop and relaxes the conservative nature of some earlier results arising from assumption of in�nite engagement time. Further, a feedforward scheme in conjunction with a lead-lag compensator is used as one control strategy while a generalized sampled hold function is used as a second strategy, to shift the RHP transmission zeros, thereby achieving ZMD. It is observed that merely shifting the RHP zero(s) to the left half plane reduces miss distances signi�cantly even when no additional controllers are used to ensure SPR conditions.

Sparsely populated residue conformations in protein structures: Revisiting ``experimental'' Ramachandran maps

The Ramachandran map clearly delineates the regions of accessible conformational (phi-) space for amino acid residues in proteins. Experimental distributions of phi, values in high-resolution protein structures, reveal sparsely populated zones within fully allowed regions and distinct clusters in apparently disallowed regions. Conformational space has been divided into 14 distinct bins. Residues adopting these relatively rare conformations are presented and amino acid propensities for these regions are estimated. Inspection of specific examples in a completely arid, fully allowed region in the top left quadrant establishes that side-chain and backbone interactions may provide the energetic compensation necessary for populating this region of phi- space. Asn, Asp, and His residues showed the highest propensities in this region. The two distinct clusters in the bottom right quadrant which are formally disallowed on strict steric considerations correspond to the gamma turn (C7 axial) conformation (Bin 12) and the i + 1 position of Type II turns (Bin 13). Of the 516 non-Gly residues in Bin 13, 384 occupied the i + 1 position of Type II turns. Further examination of these turn segments revealed a high propensity to occur at the N-terminus of helices and as a tight turn in hairpins. The strand-helix motif with the Type II turn as a connecting element was also found in as many as 57 examples. Proteins 2014; 82:1101-1112. (c) 2013 Wiley Periodicals, Inc.

On the stability of the L-p-norm of the Riemannian curvature tensor

We consider the Riemannian functional defined on the space of Riemannian metrics with unit volume on a closed smooth manifold M where R(g) and dv (g) denote the corresponding Riemannian curvature tensor and volume form and p a (0, a). First we prove that the Riemannian metrics with non-zero constant sectional curvature are strictly stable for for certain values of p. Then we conclude that they are strict local minimizers for for those values of p. Finally generalizing this result we prove that product of space forms of same type and dimension are strict local minimizer for for certain values of p.

Re-analysis of cryoEM data on HCV IRES bound to 40S subunit of human ribosome integrated with recent structural information suggests new contact regions between ribosomal proteins and HCV RNA

In this study, we combine available high resolution structural information on eukaryotic ribosomes with low resolution cryo-EM data on the Hepatitis C Viral RNA (IRES) human ribosome complex. Aided further by the prediction of RNA-protein interactions and restrained docking studies, we gain insights on their interaction at the residue level. We identified the components involved at the major and minor contact regions, and propose that there are energetically favorable local interactions between 40S ribosomal proteins and IRES domains. Domain II of the IRES interacts with ribosomal proteins S5 and S25 while the pseudoknot and the downstream domain IV region bind to ribosomal proteins S26, S28 and S5. We also provide support using UV cross-linking studies to validate our proposition of interaction between the S5 and IRES domains II and IV. We found that domain IIIe makes contact with the ribosomal protein S3a (S1e). Our model also suggests that the ribosomal protein S27 interacts with domain IIIc while S7 has a weak contact with a single base RNA bulge between junction IIIabc and IIId. The interacting residues are highly conserved among mammalian homologs while IRES RNA bases involved in contact do not show strict conservation. IRES RNA binding sites for S25 and S3a show the best conservation among related viral IRESs. The new contacts identified between ribosomal proteins and RNA are consistent with previous independent studies on RNA-binding properties of ribosomal proteins reported in literature, though information at the residue level is not available in previous studies.

Optimality Conditions and Duality for Semi-Infinite Mathematical Programming Problem with Equilibrium Constraints

This article considers a semi-infinite mathematical programming problem with equilibrium constraints (SIMPEC) defined as a semi-infinite mathematical programming problem with complementarity constraints. We establish necessary and sufficient optimality conditions for the (SIMPEC). We also formulate Wolfe- and Mond-Weir-type dual models for (SIMPEC) and establish weak, strong and strict converse duality theorems for (SIMPEC) and the corresponding dual problems under invexity assumptions.

A further discussion on basic equations for two-phase flow: On collision stress of solid phase

The following points are argued: (i) there are two independent kinds of interaction on interfaces, i.e. the interaction between phases and the collision interaction, and the jump relations on interfaces can accordingly be resolved; (ii) the stress in a particle can also be divided into background stress and collision stress corresponding to the two kinds of interaction on interfaces respectively; (iii) the collision stress, in fact, has no jump on interface, so the averaged value of its derivative is equal to the derivative of its averaged value; (iv) the stress of solid phase in the basic equations for two\|phase flow should include the collision stress, while the stress in the expression of the inter\|phase force contains the background one only. Based on the arguments, the strict method for deriving the equations for two\|phase flow developed by Drew, Ishii et al. is generalized to the dense two\|phase flow, which involves the effect of collision stress.

Bacterias halófilas extremas deteriorantes en anchoíta salada

En anchoita ( Engraulis anchoita) salada-maduradas, que poseen una actividad de agua (aw) de 0,75 a 0,80 se han encontrado bacterias halófilas . E l objetivo de este trabajo fue determinar la potencial capacidad deteriorante de los grupos bacterianos encontrados. Se realizaron estudios microbiológicos en 100 muestras de anchoíta salada-madurada. E l 71 % de las colonias halladas fueron halófilas extremas y el 29 % estrictas. De acuerdo a sus características bioquímicas se ha reconocido un 31% de Halococcus sp.; 15% de Haloferax spp. 5% de Halobacterium spp. y 7% de Haloarcula spp., el resto se encuentra aún sin identificar. De las bacterias halladas un 30% tienen actividad proteolítica, 30% lipolítica y 15% proteolítica y lipolítica. La presencia de estas bacterias podría llevar a modificaciones irreversibles y no deseables en distintas características sensoriales como olor, color y textura, que limitarían la vida útil de estos productos. La importancia de esta limitación estará dada por el número, las características de las mismas y las condiciones de almacenamiento del producto.

El pensamiento filosófico-jurídico de Juan Alfredo Casaubón

Resumen: En el presente trabajo se estudia y analiza el pensamiento iusfilosófico de Juan Alfredo Casaubón, unos de los autores iusnaturalistas más significativo de la Argentina en el siglo XX. Heredero de la tradición clásica que conocerá en los famosos Cursos de Cultura Católica y, posteriormente, en la Pontificia Universidad Católica Santa María de los Buenos Aires, de la cual será uno de sus profesores fundadores. Abogado, docente, juez, investigador, padre y esposo. Su pensamiento, si bien se puede encuadrar en la Tradición Central de Occidente, tendrá diversas particularidades que le darán a su pensamiento una nueva impronta a la filosofía jurídica. Se ha tratado de sintetizar el pensamiento casaubiano en diez tesis principales que reflejan en su estricta medida todo el corpus de este filósofo argentino. Previo al desarrollo iusfilosófico del autor, se ha tratado de encuadrar su posición filosófica general y, luego, jurídica, a través de su concepción iusnaturalista. Por último, se hará un pequeño homenaje a este gran pensador en el marco de la filosofía argentina del siglo XX.

Después de la crisis financiera : revisión del debate entre la ética y la economía

Resumen: La fuerte crisis financiera y los hechos internacionales más recientes están atravesados por grandes cuestionamientos acerca de la relación entre la ética y la economía, y la responsabilidad que la economía de mercado pueda tener en problemas sociales y políticos más profundos. En este artículo se presentan algunas de las dimensiones del debate entre la ética y la economía que están detrás de la cuestión fundamental del rol de las responsabilidades éticas en la crisis financiera. El tema es abordado desde una perspectiva que considera que existe un fuerte vínculo entre la ética y la economía. Esta visión representa un desafío frente al punto de vista tradicional, que sostiene que debe haber una separación estricta entre la racionalidad ética y la racionalidad económica.

El origen de la comunidad política en Giovanni Botero. Influencias medievales y prefiguración de conceptos modernos

Resumen: El presente trabajo busca analizar las ideas sobre el origen de la comunidad política en el teólogo católico piamontés del siglo XVI, Giovanni Botero. El propósito, en primer lugar, es intentar delinear cuáles pudieron haber sido las influencias de la Antigüedad clásica y de la Cristiandad medieval en este pensador, tratando de vislumbrar la conexión con las tendencias aristotélico-tomistas, por un lado y las latino-ciceronianas, por otro. Y en segundo término, asimismo se buscará dilucidar cómo, a partir de estas ideas, comienzan a aparecer en este pensador católico algunas referencias que demuestran, sino un quiebre, por lo menos una cierta variación en el pensamiento político, variación que puede compararse con los cuidados necesarios, con las clásicas teorías políticas modernas. El objetivo final se enmarca en proveer un primer acercamiento a una temática compleja que en estudios posteriores puede enfocarse desde perspectivas distintas a las clásicamente estudiadas: la temática del “tránsito” entre las ideas políticas medievales y modernas.

La oda latina a Venus de Garcilaso de la Vega: adopción de la tradición clásica y su traducción española como relación de transitividad

Resumen: Garcilaso de la Vega, siguiendo el canon pedagógico humanista, se constituyó en un poeta que no solo adoptó la tradición de la lírica clásica en la absorción de temas y motivos, sino que también ensayó la composición de odas, a la manera horaciana, en lengua latina. Estas composiciones, regidas por las reglas métricas que se enseñaban en las escuelas de gramática y retórica, conservan la estructura estrófica y la rigurosa alternancia de sílabas breves y largas. El interés filológico en torno de estos poemas, por los cuales Garcilaso fue elogiado por los intelectuales de su época, es tardío ya que en las primeras ediciones de la obra del toledano no aparecen; será a finales del siglo XIX cuando se ponga la mirada sobre ellos y se comprenderá cuál es la importancia del contexto italiano de composición y el compromiso del poeta con lo clásico. Este cruce de imaginarios, que tiene como límite último la producción poética de Garcilaso, puede entenderse como un ejercicio de traducibilidad entre el sentido de un sistema semiótico adoptado, como es en este caso la utilización de la lengua latina, y la posibilidad de decir algo de ello, lo que implica producir significación; asimismo este juego de traspasos enunciativos se completa con la traducción a la lengua española de las odas latinas de Garcilaso. En consecuencia, los objetivos de la presente comunicación están orientados a analizar los dos pasos de la actividad semántica que se opera en toda relación de traducción: en este caso entre la oda a Venus creada por el poeta hispano y la versión de Nemesia Matarrodona Vizcaíno, quien transpone al español el texto garcilasiano en la edición de Sotelo Salas, del año 1976.

Complete solution of the columbus problem for large-disturbance cases

The Columbus problem has been rigorously solved by Lyapunov's direct approach to the continuous system in gencral cases of large disturbance and the theory has proved to be in strict consistency with Kelvin's experiments.

One-dimensional improvement and two-dimensional and 3-dimensional treatments for stable oscillation condition, mode structure and power output in high-speed-flow lasers

For high-speed-flow lasers, the one-dimensional and first-order approximate treatment in[1] under approximation of geometrical optics is improved still within the scope of approx-imation of geometrical optics. The strict accurate results are obtained, and what is more,two- and three-dimensional treatments are done. Thus for two- and three-dimensional cases, thestable oscillation condition, the formulae of power output and analytical expression of modesunder approximation of geometrical optics (in terms of gain function) are derived. Accord-ing to the present theory, one-and two-dimensional calculations for the typical case of Gerry'sexperiment are presented. All the results coincide well with the experiment and are better thanthe results obtained in [1].In addition, the applicable scope of Lee's stable oscillation condition given by [1] is ex-panded; the condition for the approximation of gcometrical optics to be applied to mode con-structure in optical cavity is obtained for the first time and the difference between thiscondition and that for free space is also pointed out in the present work.