Intertemporal and Spatial Location of Disposal Facilities

The optimal capacity and location of a sequence of landfills are studied, and the interactions between both decisions are pointed out. Deciding the capacity of a landfill has some spatial implications, because it effects the feasible region for the rest of the landfills, and some temporal implications because the capacity determines the lifetime of the landfill and hence the instant of time where the next landfills will need to be constructed. Some general mathematical properties of the solution are provided and interpreted from an economic point of view. The resulting problem turns out to be nonconvex and, therefore, it can not be solved by conventional optimization techniques. Some global optimization methods are used to solve the problem in a particular case to illustrate the behavior of the solution depending on the parameter values.Landfilling, Optimal Capacity, Optimal Location, Global Optimization.

When omnigeneity fails

A generic non-symmetric magnetic field does not confine magnetized charged particles for long times due to secular magnetic drifts. Stellarator magnetic fields should be omnigeneous (that is, designed such that the secular drifts vanish), but perfect omnigeneity is technically impossible. There always are small deviations from omnigeneity that necessarily have large gradients. The amplification of the energy flux caused by a deviation of size $\epsilon$ is calculated and it is shown that the scaling with $\epsilon$ of the amplification factor can be as large as linear. In opposition to common wisdom, most of the transport is not due to particles trapped in ripple wells, but to the perturbed motion of particles trapped in the omnigeneous magnetic wells around their bounce points.Comment: 6 pages, 2 figure

Forest Ecosystem Services: An Analysis of Worldwide Research

The relevance of forests to sustain human well-being and the serious threats they face have led to a notable increase of research works on forest ecosystem services during the last few years. This paper analyses the worldwide research dynamics on forest ecosystem services in the period from 1998 to 2017. A bibliometric analysis of 4284 articles was conducted. The results showed that the number of published research articles has especially increased during the last five years. In total, 68.63% of the articles were published in this period. This research line experiences a growing trend superior to the general publishing trend on forest research. In spite of this increase, its relative significance within the forest research is still limited. The most productive subject areas corresponded to Environmental Science, Agricultural and Biological Sciences and Social Sciences Economic topics are understudied. The scientific production is published in a wide range of journals. The three first publishing countries are United States, China and the United Kingdom. The most productive authors are attached to diverse research centres and their contributions are relatively recent. A high level of international cooperation has been observed between countries, institutions and authors. The findings of this study are useful for researchers since they give them an overview of the worldwide research trends on forest ecosystem services

Intertemporal and Spacial Location of Disposal Facilities

Optimal capacity and location of a sequence of landfills are studied, and the interactions between both decisions are pointed out. The decision capacity has some spatial implications, because it affects the feasible region for the rest of landfills, and some temporal implications, because the capacity determines the lifetime of the landfill and hence the instant of time where next landfills will need to be constructed. Some general mathematical properties of the solution are provided and interpreted from an economic point of view. The resulting problem turns out to be no convex and therefore it can not be solved by conventional optimization techniques. Some global optimization methods are used to solve the problem in a particular case, in order to illustrate the behavior of the solution depending on parameter value

Controlled Heterometallic Composition in Linear Trinuclear [LnCeLn] Lanthanide Molecular Assemblies.

The combination of two different β-diketone ligands facilitates the size-controlled assembly of pure heterometallic [LnLn'Ln] linear compounds thanks to two different coordination sites present in the molecular scaffold. [HoCeHo], [ErCeEr], and [YbCeYb] analogues are presented here and are characterized both in the solid state and in solution, demonstrating the selectivity of this unique method to produce heterometallic 4f molecular entities

Large Attractive Depletion Interactions in Soft Repulsive-Sphere Binary Mixtures

We consider binary mixtures of soft repulsive spherical particles and calculate the depletion interaction between two big spheres mediated by the fluid of small spheres, using different theoretical and simulation methods. The validity of the theoretical approach, a virial expansion in terms of the density of the small spheres, is checked against simulation results. Attention is given to the approach toward the hard-sphere limit, and to the effect of density and temperature on the strength of the depletion potential. Our results indicate, surprisingly, that even a modest degree of softness in the pair potential governing the direct interactions between the particles may lead to a significantly more attractive total effective potential for the big spheres than in the hard-sphere case. This might lead to significant differences in phase behavior, structure and dynamics of a binary mixture of soft repulsive spheres. In particular, a perturbative scheme is applied to predict the phase diagram of an effective system of big spheres interacting via depletion forces for a size ratio of small and big spheres of 0.2; this diagram includes the usual fluid-solid transition but, in the soft-sphere case, the metastable fluid-fluid transition, which is probably absent in hard-sphere mixtures, is close to being stable with respect to direct fluid-solid coexistence. From these results the interesting possibility arises that, for sufficiently soft repulsive particles, this phase transition could become stable. Possible implications for the phase behavior of real colloidal dispersions are discussed.Comment: 31 pages, 8 figures; version accepted for publication in the Journal of Chemical Physic

Ethnobotany, volatile iols and secretion tissues of Werneria poposa from Argentina

Folk medicines are gaining great importance as information sources on traditional medicinal plants. The aim of this paper is the study of a plant traditionally employed by the Puna inhabitants: Werneria poposa Phil. Morphology of its secretory tissue and other histological diagnostic features, as well as the chemical composition of its essential oil, is described. Puna inhabitants use W. poposa mainly as an infusion for mountain sickness ('soroche'), stomach and hepatic disorders and cold. It is also used externally as a hot bath or unguent for rheumatic pains or traumas. Secretory tissues are schizogenous ducts in leaves and stems. Thirty-one components were detected in the essential oil by means of GC/MS analysis. Oil was characterized by the presence of high content of β-pinene (21.7%), α-pinene (5.5%), terpinen-4-ol (5.3%), α-terpinene (5.2%), β-phellandrene + 1,8-cineole (4.8%), isopulegol (4.8%) and β-citronellal (4.6%). At the present time, W. poposa is consumed as a medicinal plant, mainly in the northwest of Argentina, not being commercialized in the urban centers.Facultad de Ciencias Naturales y Muse

Vástago femoral PMC en cirugía protésica de cadera: revisión clínica y radiológica

Evaluamos los resultados clínicos y radiológicos de nuestros 100 primeros casos consecutivos de sustitución protésica de cadera mediante modelo de vástago cementado PMC, realizando un seguimiento mínimo de 30 meses. La media de edad de los pacientes intervenidos ha sido de 75 años. El diagnóstico en 31 de los casos fue de coxartrosis, 63 fracturas y 6 otros. El 94% de los pacientes fueron intervenidos por abordaje posterolateral. La puntuación según la escala de Harris modificada fue de 82 puntos, 92 para las prótesis híbridas y 72 para las bicéntricas. Los hallazgos clinicorradiológicos sólo mostraron el aflojamiento de 1 vastago en la serie; no encontramos alteraciones en la interfaz cemento-prótesis.We reviewed 100 consecutive hip arthroplasties with a cemented femoral component (PMC) after 30 months of follow-up. The average age of patients was 75 years. The diagnosis was osteoarthritis in 31 hips, fractures in 63 hips and others in 6. 94% hip arthroplasties were performed through the posterolateral approach. The mean Harris score at latest 30-month follow- up, was 82 points, 92 points in hybrid arthroplasties and 72 in bipolar arthroplasties. Radiographic and clinic follow-up had showed loosening of 1 stem, without abnormalities in the interface cement-prosthesis