Measurement and analysis of soil nitrogen and organic matter content using near-infrared spectroscopy techniques

Near infrared reflectance （N1R） spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen （N） and organic matter （OM） content in a soil of Zhejiang Province, Hangzhou County. A total of 125 soil samples were taken from the field. Ninety-five samples spectra were used during the calibration and cross validation stage. Thirty samples spectra were used to predict N and OM concentration. NIR spectra of these samples were correlated using partial least square regression. The regression coefficients between measured and predicted values of N and OM was 0.92 and 0.93, and SEP （standard error of prediction） were 3.28 and 0.06, respectively, which showed that NIR method had potential to accurately predict these constituents in this soil. The results showed that NIR spectroscopy could be a good tool for precision farming application.     

Impact in the school system of a strategy for identifying and selecting academically talented students: the experience of Program PENTA‐UC

The study explores the consequences, for participating schools, of the implementation of a system for the identification and selection of academically talented students, in the context of an extracurricular enrichment program operating at Pontificia Universidad Católica de Chile. The participants were 73 students, 50 teachers, and seven members of the school administration, in seven schools. Data were collected through interviews and focus groups. The results indicated that the identification and selection processes have mostly positive effects on teachers and students. Some potentially negative effects were also detected for the classmates of the talented students, which relate mainly to the manner in which information was handled. Possible implications of these findings for this program for talented children and other similar programs are discussed.     

Cosmopolitical encounters: Prototyping at the National Zoo in Santiago,Chile

This article presents an empirical reflection on how the prototyping of an environmental enrichment device for chimpanzees at the National Zoo of Chile precipitates a cosmopolitical encounter. Using material produced by design students, zookeepers and the chimps Judy and Gombe, we describe how prototyping iterations establish open processes of dialogue and encounters among humans and nonhumans. The case will demonstrate how prototyping can go further than the generation of models of an original. On the contrary, the cosmopolitical encounter emerging from the prototyping process makes evident a truly ontological vocation, acknowledging humans and other-than-human beings as singular entities. Its provisional and malleable nature turns this device into a privileged locus for the exploration of interspecies entanglement. Although zoos are scientifically organized institutions, in this case we observe how its anthropocentric hierarchy was performatively reshuffled at certain moments of the prototyping process. The cosmopolitical qualities of the prototyping process analyzed derive from its capacity to deploy an ethics of attention and care between the agencies at play, that is, for unfold gestures of mutual vulnerability. Finally, we propose prototyping as a device for moving from cosmopolitics as a way of understanding the world to cosmopolitics as a matter of design.     

Acerca del hielo en el islam medieval

The history of ice in medieval Arab societies is obscured behind a mosaic of a variety of references and scholarly citations. Beyond al-Qalqashandī's reference to organised ice trafficking in fourteenth-century Mamluk Egypt, we do not have conclusive evidence on the origin and use of ice as a consumer product. In this paper we trace its presence based on three genres of references: historical and literary quotations, medicine and literature pertaining to food. These references allow us to consider the extent of ice consumption in the Arab world before the ninth century, as well as the existence of an organised trade throughout the Middle Ages from that time. However, contrary to the Persian world, with its well-documented Iranian yakhchals, we still know virtually nothing about ice-houses in medieval Arab societies. We also know very little about the profession of the thallāj or ice-seller, or whether the widespread consumption of ice that originated in Spain in the sixteenth century was in fact a legacy of an earlier trade in al-Andalus.     

Color characterization of roofing slates from the Iberian Peninsula for restoration purposes

Substitution of slate roofing tiles is a conventional operation during building restoration, since tiles are very difficult to restore or clean because of the high degree of alteration they suffer. Criteria for replacement of historical building stones must be based on geological, geotechnical and esthetic parameters, among which color is of great importance. In this sense, this paper constitutes a comprehensive and useful colorimetric study of roofing slates from the Iberian Peninsula, for the purposes of restoration. The color of 50 commercial varieties of roofing slate mined in quarries from the 12 mining districts in the Iberian Peninsula was analyzed with a spectrophotometer device, by considering the CIELAB color space. The results of the study were used to develop a protocol for characterizing the color of roofing slate and to define the color range of roofing slate from the Iberian Peninsula. In addition, the similarities and differences in the color and microstructure of the different commercial varieties of Iberian roofing slate were established and the limit of acceptability of replacement of one type of slate by another was determined. Parameter h_ab was found to be the most important CIELAB color coordinate as regards the formation of homogeneous color groups, and the specular component excluded (SCE) mode was most sensitive as regards detecting color differences between two samples.