A Tale of Two Dams: The Impact of Reservoir Management on Rural Depopulation in Central Spain

In rural areas, depopulation is mainly due to a lack of economic and employment opportunities. In this context, the reservoirs already built can be a source of socioeconomic development based on tourism and outdoor leisure activities. The condition for this development to materialize is that reservoir management considers these activities. In Central Spain, a process of rural depopulation has been generated in the municipalities around the reservoirs at the Upper Tagus River, as water management allows water transfers from the Tagus to the Segura River without taking into account regulations that prioritize and protect donor basin users. Through the comparison of reservoir water management and demographic data of two rural areas close to the reservoirs, this article reveals the direct relationship between reservoir management that enables recreational uses with its consequent socioeconomic development and the maintenance of the population in the territory. Consequently, reservoir water management based on the socioeconomic development of reservoir banks is necessary and a priority over transfers to another basin.

     

Spectroscopic study of the competition between dehydration and carbonation effects in La2O3-based materials

La₂O₃ takes part in a variety of technologically interesting solids, but it has a known tendency to react with water and CO₂, which may result in nonstoichiometry of the final product and the appearance of impurities. We apply Raman spectroscopy to study hydration and carbonation effects of La₂O₃-based materials, using La(OH)₃ as starting material. The thermal evolution of La(OH)₃ reflects the competition between dehydration and carbonation kinetics, and thus is highly dependent upon environment and experimental conditions. In vacuum, La(OH)₃ evolves first to LaOOH and then to a mixture of C- and A-La₂O₃ until, upon further heating, only A-La₂O₃ phase remains. In air, La(OH)₃ yields first LaOOH, but under slow heating LaOOH converts to I, Ia and II-type oxycarbonates, in increasing order of thermal stability. II-La₂O₂CO₃, in turn, decomposes to La₂O₃ at 700 °C. Structural relations governing phase conversion within hexagonal or orthogonal-like compounds are discussed.     

纳瓦拉Berriozar幼儿园

路易斯·康认为第一所学校开始于一棵树下,当一个人知道他是老师时,他开始与其他人讨论他所学到的知识．而其他人当时并没意识到他们自己扮演了学生这一角色,和那些学生一样．3岁以下的孩子的学习是本能且无意识的,对于康的故事,有人也许会思考那棵树——也就是建筑——在教学实践中所扮演的角色。     

Radical copolymerization studies of an amphiphilic macromonomer derived from Triton X-100. Reactivity ratios determination by in situ quantitative H NMR monitoring

This article deals with the estimation of the reactivity of a novel methacrylic macromonomer with amphiphilic character derived from Triton X-100 (MT) in radical copolymerisation reaction with acrylic acid (AA). Two approaches to estimate the reactivity ratio of the macromonomer are described. The first involves the use of the Jaacks equation valid for systems with a large excess of one of the comonomers and leads to r_AA=0.31. The second method uses a low molecular weight model monomer (MTm) that reproduces the chemical structure of the macromonomer. A non-linear fitting of the experimental data of the system MTm-AA to an integrated form of the copolymerisation equation which describes the terminal model postulated by Mayo and Lewis, gave reactivity ratio values of r_MTm=2.5 and r_AA=0.30. The results obtained from the two estimations suggest that methacrylic double bond reactivity is not affected by poly(oxyethylene oxide) chain length. In situ quantitative ¹H NMR analysis was used to monitor monomer consumption and therefore to follow the course of the copolymerisation reaction in both approaches.     

Rheumatology research. Analysis of Spanish papers published in 1990-1996 in 9 foreign journals in the field

The organization of the human metallothionein (MT) gene family is more complex than the commonly used mouse and rat models. The human MTs are encoded by a family of genes consisting of 10 functional and 7 nonfunctional MT isoforms. One objective of this study was to determine if the accumulation of MT protein in cultures of human proximal tubule (HPT) cells exposed to metals is similar to that expected from the knowledge base obtained from rodent models. To accomplish this objective, HPT cells were exposed to both lethal and sublethal concentrations of Cd2+, Zn2+, Cu2+, Ag2+, Hg2+, and Pb2+ and MT protein levels were determined. The results were in general agreement with animal model studies, although there were some exceptions, mainly in areas where the animal model database was limited. In clear agreement with animal models, Cd2+, Zn2+, and Cu2+ were demonstrated to be potent inducers of MT protein accumulation. In contrast to the similarity in MT protein expression, we obtained evidence that the human renal MT-2 gene has a unique pattern of regulation compared to both animal models and human-derived cell cultures. In the present study, we determined that MT-2A mRNA was not induced by exposure of HPT cells to Cd2+ or the other metals, a finding in contrast to studies in both animal models and other human cell culture systems in which a high level of MT-2 mRNA induction occurs upon exposure to Cd2+ or Zn2+. While MT protein expression may be similar between humans and animal models, this finding provides initial evidence that regulation of the genes underlying MT protein expression may be divergent between species.     

A PROBABILISTIC MODEL FOR THE MODIFIED CLAUS PROCESS

A model is proposed for simulation of an industrial Claus unit with a straight-through configuration and two catalytic reactors. Process design evaluation based on deterministic calculations does not take into account the uncertainties associated with the input variables. The probabilistic simulation method was applied in the Claus model to obtain an impression of how some of these inaccuracies influence plant performance. The application was tested experimentally to confirm its validity, then used for control purposes.