669 research outputs found
Aquifer Depletion and the Cost of Water Conservation: The Southern High Plains of Texas Case
Irrigated agriculture has played a vital role in the development and growth of the Great Plains Region of the United States. The primary source of water for irrigation in this region is the Ogallala Aquifer. The Southern portion of the Ogallala Aquifer is considered exhaustible due to the low level of recharge relative to the quantities of water pumped. Analysis and evaluation of water conservation policies which could extend the economic life of the Ogallala Aquifer in the Southern High Plains of Texas and Eastern New Mexico, and which could contribute to maintaining the viability of the regional economy is important. This study evaluates the impacts of water conservation policies which limit drawdown of the Ogallala Aquifer. County level dynamic optimization models maximizing net present value of net returns to land, management, groundwater, and irrigation systems over a sixty year planning horizon were formulated to evaluate three aquifer drawdown restrictions. The results of this study indicate that because of the differences in hydrologic characteristics and current irrigation levels across counties in the study area, blanket water conservation policies for the region as a whole are likely to be inefficient. This study concludes that for this region, water conservation policies that focus on counties that would deplete the aquifer to less than 30 ft. of saturated thickness possess the lowest implicit cost of conserving saturated thickness.water conservation, water policy evaluation, aquifer management, dynamic optimization, Resource /Energy Economics and Policy,
Policy Alternatives for the Southern Ogallala Aquifer
Due to declining water levels in the Ogallala Aquifer, policy alternatives for extending the life of the aquifer for irrigation and other purposes are evaluated. The study concludes that blanket water conservation policies for the region are likely to be inefficient because of economic and hydrologic differences in the region.Resource /Energy Economics and Policy,
Thermal Mass Effect on the Solution Cooling Rate and on HIPped Astroloy Component Properties
Astroloy is a Ni-based superalloy with high-volume fraction of γ′, which gives high
temperature properties but reduces its forgeability. Therefore, powder metallurgy manufacturing
processes such as Near Net Shape HIPping are the most suitable manufacturing technology for
Astroloy. However, NNSHIP has its own drawbacks, such as the formation of prior particle
boundaries (PPBs), which usually tend to decrease material mechanical properties. The detrimental
effect of PPBs can be reduced by optimizing the entire HIP processing route. Conventional HIP
cycles have very low cooling rates, especially in big components from industry, and thus a series of
post-heat treatments must be applied in order to achieve desirable microstructures and improve the
mechanical properties. Standard heat treatments for Astroloy are long and tedious with several
steps of solutioning, stabilization and precipitation. In this work, two main studies have been
performed. First, the effect of the cooling rate after the solutioning treatment, which is driven by the
materials’ thermal mass, on the Astroloy microstructure and mechanical properties was studied.
Experimental analyses and simulation techniques have been used in the present work and it has
been found that higher cooling rates after solutioning increase the density of tertiary γ′ precipitates
by 85%, and their size decreases by 22%, which leads to an increase in hardness from 356 to 372
HB30. This hardness difference tends to reduce after subsequent standard heat treatment (HT) that
homogenizes the microstructure. The second study shows the effect of different heat treatments on
the microstructure and hardness of samples with two different thermal masses (can and cube). More
than double the density of γ′ precipitates was found in small cubes in comparison with cans with a
higher thermal mass. Therefore, the hardness in cubes is between 4 and 20 HB 30 higher than in
large cans, depending on the applied HT
One-year observation of leflunomide effectiveness and saftey in juvenile idiopathic arthritis : a clinical practice review (preliminary data)
BACTERIA ASSOCIATED WITH THE WEST INDIAN FRUIT FLY ANASTREPHA OBLIQUA (MACQUART) (DIPTERA: TEPHRITIDAE)
BACTERIA ASSOCIATED WITH THE WEST INDIAN FRUIT FLY ANASTREPHA OBLIQUA (MACQUART) (DIPTERA: TEPHRITIDAE
Development of brown rot epidemics in Spanish peach orchards
A new approach to modelling epidemics of brown rot caused by Monilinia spp. in Ebro Valley peach orchards has been developed. This compartmental model was subdivided according to the phenological stages in which the disease can develop (blossom, immature fruit, and ripe fruit). Information host susceptibility, primary and secondary inoculum sources and latent infections in immature fruit was taken into account. The compartmental model is described by a system of differential equations, and is simple enough to allow an analytical study of the main epidemiological factors that determine the rate of disease progress during a single growing season. The proposed model fits well to the epidemic pattern of brown rot observed in north-eastern Spain. The transmission of the disease as a non-linear term implied that small changes in the infection rate had a large effect on the development of the disease. The model has confirmed the usefulness of removing mummies (infected fruit that remains in the crop during winter) from the field to reduce the final incidence of the disease. In addition, all control measures that reduce the rate of secondary infection in ripe fruit, either through the use of more resistant varieties or the use of fungicides, are effective in reducing brown rot incidence. The proposed epidemic model is flexible and allows to add complexities to the system and evaluate the effectiveness of different control strategies.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was supported by grant PID2020-115702RB-C21 and AGL2017-84389-C2-2-R from the Ministry of Science and Innovation (Spain)
Estudio sobre la integración en aula específica, de un IES, de alumnado diagnosticado como negativista desafiante y su posible inclusión en aula ordinaria
It is known that, nowadays, with the arrival of the inclusive school, in our classrooms we find a greater functional diversity in the students than in the past, diversity that is not always known and accepted within normality. The present investigation, based on the real experience, has as objective the integration in an IES of specific classroom of students affected by serious behavior disorders, such as the defiant negativist disorder, for its later inclusion in the ordinary classroom, in principle, under supervision. The sample consists of 5 subjects whose ages range between 13 and 15 years, who, due to serious alterations in their behavior, can not have full-time schooling in the ordinary classroom. Three of these students are enrolled in 1st of Compulsory Secondary Education (ESO) and 2 of them in 2nd. The serious behavioral problems led to the application of a behavior modification program and a cognitive restructuring and a self-control training.Es sabido que, en la actualidad, con la llegada de la escuela inclusiva, en nuestras aulas nosencontramos con una mayor diversidad funcional en el alumnado que en tiempos pasados, diversidad que no siempre es conocida y aceptada dentro de la normalidad. La presente investigación, basada en la experiencia real, tiene como objetivo la integración en un IES de un aula específica de alumnado afectado de trastornos graves de conducta, como es el trastorno negativista desafiante, para su posterior inclusión en el aula ordinaria, en principio, bajo supervisión. La muestra consta de 5 sujetos cuyas edades oscilan entre los 13 y 15 años, que por presentar graves alteraciones en su conducta no pueden tener una escolarización a tiempo completo en el aula ordinaria. Tres de estos alumnos, estan matriculados en 1º de la Educación Secundaria Obligatoria (ESO) y 2 de ellos en 2º. Los graves problemas de conducta llevaron a la aplicación de un programa de modificación de conducta cognitivo conductual, a una reestructuración cognitiva y a un entrenamiento en autocontrol
Regional aerosol deposition in the human airways: the SimInhale benchmark case and a critical assessment of in silico methods
Regional deposition effects are important in the pulmonary delivery of drugs intended for the topical treatment of respiratory ailments. They also play a critical role in the systemic delivery of drugs with limited lung bioavailability. In recent years, significant improvements in the quality of pulmonary imaging have taken place, however the resolution of current imaging modalities remains inadequate for quantifying regional deposition. Computational Fluid-Particle Dynamics (CFPD) can fill this gap by providing detailed information about regional deposition in the extrathoracic and conducting airways. It is therefore not surprising that the last 15 years have seen an exponential growth in the application of CFPD methods in this area. Survey of the recent literature however, reveals a wide variability in the range of modelling approaches used and in the assumptions made about important physical processes taking place during aerosol inhalation. The purpose of this work is to provide a concise critical review of the computational approaches used to date, and to present a benchmark case for validation of future studies in the upper airways. In the spirit of providing the wider community with a reference for quality assurance of CFPD studies, in vitro deposition measurements have been conducted in a human-based model of the upper airways, and several groups within MP1404 SimInhale have computed the same case using a variety of simulation and discretization approaches. Here, we report the results of this collaborative effort and provide a critical discussion of the performance of the various simulation methods. The benchmark case, in vitro deposition data and in silico results will be published online and made available to the wider community. Particle image velocimetry measurements of the flow, as well as additional numerical results from the community, will be appended to the online database as they become available in the future
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