Integrated economic-hydrologic water modeling at the basin scale: the Maipo river basin

Increasing competition for water across sectors increases the importance of the river basin as the appropriate unit of analysis to address the challenges facing water resources management; and modeling at this scale can provide essential information for policymakers in their resource allocation decisions. This paper introduces an integrated economic-hydrologic modeling framework that accounts for the interactions between water allocation, farmer input choice, agricultural productivity, nonagricultural water demand, and resource degradation in order to estimate the social and economic gains from improvement in the allocation and efficiency of water use. The model is applied to the Maipo River Basin in Chile. Economic benefits to water use are evaluated for different demand management instruments, including markets in tradable water rights, based on production and benefit functions with respect to water for the agricultural and urban-industrial sectors.Resource allocation., Water resources development Chile., Chile.,

Plan de negocios de una lavadora de autos livianos al Sur de Quito "rápido y brillosos"

The present business plan of "Fast and Gloss" examines the economic feasibility of providing the service of automatic car wash in the southern of Quito as a new and unique service that uses cutting edge technology, high standards of quality and personalized attention. The constant growth of the country's automotive sector, due to the existing credit facilities as to the need for mobility has pointed out that many people make a significant investment to access to this asset, in this regard is very appropiate to offer the service of automatic car wash to help the users preserve their investment.El presente plan de negocios de “Rápido & Brilloso” analiza la viabilidad económica de prestar el servicio de lavado automático de autos en el sur de la ciudad de Quito como un servicio único y novedoso que utiliza tecnología de punta, altos estándares de calidad y atención personalizada. El constante crecimiento del sector automotriz del país, tanto por las facilidades crediticias existentes como por la necesidad de contar con movilidad propia, ha precisado que muchas personas realicen una importante inversión para acceder a dicho bien; en tal sentido, es conveniente ofertar un servicio de lavado automático que ayude a preservar la inversión...

Comparación de fórmulas chilenas e internacionales para valorar el arbolado urbano

Ponce-Donoso, M (reprint author), Univ Talca, Fac Ciencias Forestales, Casilla 747, Talca, Chile.The appraisal of urban trees is a practice adopted in diverse cities of world. This survey compared international formulae: Council of Tree Landscape Appraiser (CTLA), Burnley, Helliwell and Standard Tree Evaluation Method (STEM) and three Chilean methods applied in municipalities of Concepcion, La Pintana, Maip (COPIMA), Nunoa and Penalolen, in 14 different trees located in Talca city (Chile). The objective was to identify the differences and similarities of the monetary result in the application of these formulae, which was realized by a professional. These were analyzed using a non parametric variance test of Kruskal - Wallis and the multiple comparisons Duncan test. It was possible to determine that the Chilean formulae did not present statistically significant differences with the international formulae of Burnley and CTLA; whereas Penalolen and COPIMA formulae did not present any difference when contrasted with Helliwell. In addition, the STEM formula presented differences with all the Chilean analyzed formulae. In the valuation by tree, statistically significant differences were obtained, which showed the independence of the used formula. The exception was when being applied to emblematic species or to species that stand-out in some amenity. Likewise, it was observed that the basic value continues having a high impact in the appraisal final result and the use of the statistical test applied allows extending this type of analyses

The phytoplankton and limnological characteristics of Lago Rupanco, Osorno, Chile

Lago Rupanco is located in the central plain of Chile (Borgel, 1964) at 40° 50' S; 72° 30' W. It lies at 117 m above sea level, and corresponds to type 28c of Hutchinson's (1967) classification. Lago Rupanco is a warm, monomictic lake, with winter circulation and summer stratification. Physical, chemical and biological parameters of this lake were studied during a cycle of 18 months for the first time in 1981-1982. Lago Rupanco has a maximum depth of 160 m. The euphotic zone was sampled and the temperature ranged from 10 to 18 C with an oxygen content between 9 and 11 mg/1. This lake had small amounts of nitrate-nitrogen and phosphate-phosphorous, as is characteristic of oligotrophic lakes. The phytoplankton was analyzed qualitatively and quantitatively. A total of 84 taxa was identified. Maximum and minimum values of phytoplankton relative abundance occurred in spring and fall, respectively. The phytoplanktonic biomass was at its maximum in summer and at its minimum in fall. Four species were the most abundant, Melosira granulata, Sphaerocystis schroeteri, Botryococcus braunii and Dinobryon divergens. Seasonal succession among the Bacillariophyceae, Chlorophyceae and Chrysophyceae was observed. The relationships between abiotic factors and the phytoplankton standing crop are discussed

Hydric behaviour and gas exchange in different grapevine varieties (Vitis vinifera L.) from the Maule Valley (Chile)

In the near future, stomatal behaviour will be crucial to counteract conditions arising from climate change.  Grapevine varieties are classified as either isohydric or anisohydric, depending on the sensitivity of stomatato water deficit and on their water potential homeostasis. However, the great variability observed in different studies indicates that a continuum exists in the range of stomatal sensitivity to water stress. Thus, more knowledge about the hydric behaviour and the gas exchange of isohydric and anisohydric grapevine varieties under different water conditions could lead to the development of irrigation strategies oriented at improving water-use efficiency, yield and berry composition. In this study, research was conducted in order to characterise the stomatal regulation of four different Vitis vinifera L. varieties, namely Pinot noir, Sauvignon blanc, Chardonnay and Merlot, according to soil water status. Measurements of leaf gas exchange, together with measurements of stem water potential (Ψs) and leaf water potential (Ψl), were taken during two seasons. Under conditions of water stress, Chardonnay and Merlot reached a minimum Ψs of -1.67 and -1.68 MPa respectively, and higher levels of water-use efficiency (AN/gs), of 62.3 and 69.7 μmol CO2/mol H2O respectively. In Sauvignon blanc and Pinot noir, the minimum Ψs was -1.26 and -1.40 MParespectively, with lower levels of AN/gs (53.1 and 50.5 μmol CO2/mol H2O, respectively). Under conditions of water stress (Ψl < -0.9 MPa and Ψs < -0.6 MPa), all varieties had a significantly increased AN/gs1, despitea significant reduction in gas exchange. Therefore, the hydric behaviour and gas exchange observed in this study suggest that Chardonnay and Merlot could be characterised as anisohydric varieties, as they present less sensitive stomatal control, while Pinot noir can be classified as a near-anisohydric variety and Sauvignon blanc as an isohydric variety. New investigations should consider other characteristics of the varieties to classify them better

Modelling free surface flows with smoothed particle hydrodynamics

In this paper the method of Smoothed Particle Hydrodynamics (SPH) is extended to include an adaptive density kernel estimation (ADKE) procedure. It is shown that for a van der Waals (vdW) fluid, this method can be used to deal with free-surface phenomena without difficulties. In particular, arbitrary moving boundaries can be easily handled because surface tension is effectively simulated by the cohesive pressure forces. Moreover, the ADKE method is seen to increase both the accuracy and stability of SPH since it allows the width of the kernel interpolant to vary locally in a way that only the minimum necessary smoothing is applied at and near free surfaces and sharp fluid-fluid interfaces. The method is robust and easy to implement. Examples of its resolving power are given for both the formation of a circular liquid drop under surface tension and the nonlinear oscillation of excited drops

Mediation of Problematic Use in the Relationship Between Types of Internet Use and Subjective Well-Being in Schoolchildren

Indexación: ScopusSubjective well-being is a broad category of phenomena that includes people’s emotional responses, domain satisfactions, and global judgments of life satisfaction. This research investigates how schoolchildren’s subjective well-being is affected by the different types of technology use, in personal contexts, and, concurrently, whether these effects are different when the use of technology is problematic. The central hypotheses are as follows: (1) the use of the Internet affects the subjective well-being of schoolchildren negatively only when this use is problematic and (2) the effect on subjective well-being is different according to the type of Internet use. To respond to the objectives of the research, a survey was applied to 15-year-old adolescents (2,579 cases), distributed in 330 public schools, beneficiaries of a government program for the delivery of personal computers and Internet for a year. The different uses of the Internet were measured using frequency scales by type of activity (social, recreational, and educational). Problematic use scale measured the perception of negative consequences of the intensity of Internet use on a daily basis. Subjective well-being was measured by the Personal Well-Being Index-School Children (PWI-SC). Subsequently, for analytical purposes, three simple mediation models were created, whose dependent variable was PWI-SC, while its independent variables were Internet use scales differentiated by purpose (social, recreational, and educational) and problematic use as a mediating variable, as well as attributes of the subjects and their social environment, which were incorporated as control variables. The main results show that only if Internet use is expressed as problematic does it negatively affect subjective well-being. On the contrary, when the use of the Internet is not problematic, the effect is positive and even greater than the simple effect (without mediation) between these two variables. This finding is relevant, since it allows us to provide evidence that suggests that, when studying the effect that the intensity of the Internet, firstly, one must consider the mediating effect exerted by the network’s problematic use and, secondly, that not all types of use have the same impact. Therefore, it is useful to enrich the discussion on subjective well-being and social integration of schoolchildren in the digital age. © Copyright © 2021 Donoso, Casas, Rubio and Céspedes.https://www.frontiersin.org/articles/10.3389/fpsyg.2021.641178/ful

Clustering of Radio Galaxies and Quasars

We compute the cross-correlation between a sample of 14,000 radio-loud AGN (RLAGN) with redshifts between 0.4 and 0.8 selected from the Sloan Digital Sky Survey and a reference sample of 1.2 million luminous red galaxies in the same redshift range. We quantify how the clustering of radio-loud AGN depends on host galaxy mass and on radio luminosity. Radio-loud AGN are clustered more strongly on all scales than control samples of radio-quiet galaxies with the same stellar masses and redshifts, but the differences are largest on scales less than 1 Mpc. In addition, the clustering amplitude of the RLAGN varies significantly with radio luminosity on scales less than 1 Mpc. This proves that the gaseous environment of a galaxy on the scale of its dark matter halo, plays a key role in determining not only the probability that a galaxy is radio-loud AGN, but also the total luminosity of the radio jet. Next, we compare the clustering of radio galaxies with that of radio-loud quasars in the same redshift range. Unified models predict that both types of active nuclei should cluster in the same way. Our data show that most RLAGN are clustered more strongly than radio-loud QSOs, even when the AGN and QSO samples are matched in both black hole mass and radio luminosity. Only the most extreme RLAGN and RLQSOs in our sample, with radio luminosities in excess of 10^26 W/Hz, have similar clustering properties. The majority of the strongly evolving RLAGN population at z~0.5 are found in different environments to the quasars, and hence must be triggered by a different physical mechanism.Comment: 12 pages, 13 Figures, submitted to MNRA