Recent investigations of early Roman cameo glass : Part 1 . Cameo manufacturing technique and rotary scratches of ancient glass vessels

The manufacturing traces of ancient cameo glass were investigated. These investigations had a surprising result: early Roman cameo glass vessels have not been cut from overlay blanks. Instead, their manufacture appears to be related to the molding of multi-layered cameo glass gems and to the contemporary relief ceramics. The basic principle of the assumed cameo glass manufacturing process has been experimentally verified. Independently, the typical rotary "Scratches" of ancient glass vessels were investigated. Rotary Scratches are also a typical feature of early Roman cameo glass. The investigation confirms that these Scratches are not grinding marks. They were obviously generated during the hot manufacturing process

Oxy-fuel conversion of a TV glass tank and experience with noncatalytic denitrification

The melting tank for TV funnel glass at SCHOTT GLAS was converted in 1996 from regenerative to oxy-fuel firing. The conversion was necessary to allow the required increase in tank size and pull. In connection with the conversion, the ΝΟx emission was to be reduced to less than 1000 mg/m3. Due to the special conditions regarding the oxy-fuel firing, the local authorities accepted an equivalent, mass-related ΝΟx emission limit. Furthermore, the authorities demanded the implementation of the SNCR denitrification process for further improvements. During the test period of the SNCR processing, problems with the stability of the temperature in the reaction zone and the homogenization between flue gas and ammonia appeared. The process was optimized. Additional purging air was used in the reaction zone, in order to control the temperature in the flue gas and in order to improve the mixing of the ammonia with the flue gas. The high load of condensate in the flue gas had a severe corrosion impact on the SNCR processing. Frequent maintenance is required for the ammonia insertion nozzles. The requested emission limit for ΝΟx could not be met without the application of the SNCR processing

Conservation and Restoration of Pine Forest Genetic Resources in México

Deforestation rates in México are about 670,000 ha/year. This threatens the richness of forest genetic resources in México, causing the disappearance of locally adapted populations and rare and endangered pine species. México is one of the six megadiverse countries in the world, with half of the world’s Pinus species. Pinus is one of the most economically and ecologically important forest genera in México. We suggest that delineation of seed zones and the establishment of a network of Forest Genetic Resource Conservation Units (FGRCUs), linked with forest management and ecological restoration programs will protect this valuable resource. We estimate that FGRCUs should include 25 to 50 ha each, with at least one FGRCU for each priority species in each seed zone. We highlight the need for studies of adaptive genetic variation among pine populations and for new methodologies and techniques to suit ecological restoration under Mexican forest conditions. We briefly describe ongoing research on these topics on forests owned by a well-organized indigenous community in Nuevo San Juan Parangaricutiro, Michoacán, western México

La crítica y el "estado de excepción" que es la regla.

Este ensayo propone una lectura de la VIII de las Tesis sobre la historia, de Benjamin que la “emplea”, en el sentido en que el propio Benjamin sostenía que una exposición materialista de la historia debía emplear los fragmentos del pasado para interrogar radicalmente el presente y resistir a las opresiones. Se pone en relación esta tesis con las palabras de las mujeres zapatistas, pronunciadas con motivo de la inauguración del Segundo encuentro internacional de mujeres que luchan, para argumentar que el “estado de excepción” que Benjamin había advertido era en verdad la regla, lo sigue siendo hoy específicamente (aunque no únicamente) para las mujeres y otros cuerpos, individuales y colectivos, feminizados.  Se argumenta también que la tradición de lucha de las mujeres indígenas producida por una colonialidad capitalista que sigue en curso es la que hoy nos muestra la normalidad del “estado de excepción” contemporáneo. Finalmente se propone que las luchas de las mujeres son, también, ejercicios críticos y prácticas de resistencia e invención, para una justicia por-venir

La crítica y el "estado de excepción" que es la regla.: Una lectura de Benjamin por y para las luchas de las mujeres.

This essay proposes a reading of the VIII of Benjamin's Theses on history  "using" it, in the sense that Benjamin himself maintained that a materialist presentation of history must make use of fragments of the past to radically question the present, and resist oppression. This thesis is compared to the words of the Zapatista women, spoken on the occasion of the inauguration of the Second International Meeting of Fighting Women, to argue that the "State of exception" that, as Benjamin stated, was the rule, continues to be so today specifically (although not exclusively) for women and other feminized bodies, both individual and collective. It is also argued that the fighting tradition of indigenous women produced by a Capitalist Coloniality that is still ongoing, currently shows us the normality of the contemporary "state of exception". Finally, women's fights are proposed to also be criticism exercises and resistance and inventiveness practices, for a justice “to-come”.Este ensayo propone una lectura de la VIII de las Tesis sobre la historia, de Benjamin que la “emplea”, en el sentido en que el propio Benjamin sostenía que una exposición materialista de la historia debía emplear los fragmentos del pasado para interrogar radicalmente el presente y resistir a las opresiones. Se pone en relación esta tesis con las palabras de las mujeres zapatistas, pronunciadas con motivo de la inauguración del Segundo encuentro internacional de mujeres que luchan, para argumentar que el “estado de excepción” que Benjamin había advertido era en verdad la regla, lo sigue siendo hoy específicamente (aunque no únicamente) para las mujeres y otros cuerpos, individuales y colectivos, feminizados.  Se argumenta también que la tradición de lucha de las mujeres indígenas producida por una colonialidad capitalista que sigue en curso es la que hoy nos muestra la normalidad del “estado de excepción” contemporáneo. Finalmente se propone que las luchas de las mujeres son, también, ejercicios críticos y prácticas de resistencia e invención, para una justicia por-venir

Not all adiabatic vacua are physical states

Adiabatic vacua are known to be Hadamard states. We show, however that the energy-momentum tensor of a linear Klein-Gordon field on Robertson-Walker spaces developes a generic singularity on the initial hypersurface if the adiabatic vacuum is of order less than four. Therefore, adiabatic vacua are physically reasonable only if their order is at least four. A certain non-local large momentum expansion of the mode functions has recently been suggested to yield the subtraction terms needed to remove the ultraviolet divergences in the energy-momentum tensor. We find that this scheme fails to reproduce the trace anomaly and therefore is not equivalent to adiabatic regularisation.Comment: 13 pages, LaTex2

A Partial-Closure Canonicity Test to Increase the Efficiency of CbO-Type Algorithms

Computing formal concepts is a fundamental part of Formal Concept Analysis and the design of increasingly efficient algorithms to carry out this task is a continuing strand of FCA research. Most approaches suffer from the repeated computation of the same formal concepts and, initially, algorithms concentrated on efficient searches through already computed results to detect these repeats, until the so-called canonicity test was introduced. The canonicity test meant that it was sufficient to examine the attributes of a computed concept to determine its newness: searching through previously computed concepts was no longer necessary. The employment of this test in Close-by-One type algorithms has proved to be highly effective. The typical CbO approach is to compute a concept and then test its canonicity. This paper describes a more efficient approach, whereby a concept need only be partially computed in order to carry out the test. Only if it passes the test does the computation of the concept need to be completed. This paper presents this ‘partial-closure’ canonicity test in the In-Close algorithm and compares it to a traditional CbO algorithm to demonstrate the increase in efficiency