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The present research aims to evaluate the physicochemical variables involved in the anaerobic digestion process to produce methane from manure on an agricultural farm; the farm has 2 equines that generate 12 Kg of manure per day. A manure sample was collected, and the following physicochemical parameters were determined: total solids, volatile solids, chemical oxygen demand, and pH. A tubular household biodigester was then implemented, consisting mainly of a polyethylene geomembrane that stores the organic matter and in which anaerobic digestion takes place. The performance of the biodigester was determined by the removal of organic matter quantified by volatile solids and chemical oxygen demand in the biodigester influent and digestate, of which removal of 82% of volatile solids and 74% of chemical oxygen demand was achieved. The average biogas production was 0.5 m3/day, and its lower heating value was 26,000 kJ/m3. The pH level of the biodigester was within the range of 6-7, in order to keep the methanogenic bacteria active, in charge of carrying out physicochemical process that guarantees anaerobic digestion and thus, the production of biogas.

Direction and speed wind shear modify turbine performance by changing inflow conditions on turbine blades. Using observations from the 2013 CWEX campaign, we found the daily atmospheric boundary layer transitions (morning and evening) match periods of high electricity demand for a wind farm in central Iowa. Power production during these periods was undermined for large direction shear and low speed shear scenarios. The morning transition displayed larger direction shear over the rotor layer for most wind speeds compared to the evening period. This resulted in lower turbine performance for the morning compared to the evening and whole day. This study shows that the combined effect of direction and speed shear is affecting turbine operation during high electricity demand times of day, predominantly during the morning at this wind farm.

The main goal of the present paper is to show how to form a constellation of small satellites when all small satellites leave from a larger spacecraft. It is assumed that they will all stay in a planar formation, in the same orbital plane of the mother spacecraft, just dispersed in terms of mean anomaly. Initially, it is considered that the larger satellite orbits the Earth in an almost circular orbit with 2000 km of altitude. Then, a search for initial conditions of the small satellite is performed to find the best ones to move it away from the larger satellite such that it is allocated in a co-orbital orbit with respect to the larger satellite. These initial conditions should minimize the consumption of an impulsive maneuver required to move away the small satellite from the large one to put it in course to its final orbit, trying to make the best use of the most relevant perturbations, such as the solar radiation pressure and the oblateness of the Earth. In a second study, we will analyze the influence of the solar radiation pressure, depending on the A/m ratio of the spacecraft, in the trajectories.

In the present work luminescence properties of terbium trivalent (Tb3+) doped ZrO2 were studied. Ultrasonic spray pyrolysis (USP) technique was employed to deposit the films. PL emission of the ZrO2:Tb3+ films exhibits emission peaks around 489, 548, 588, and 620 nm corresponding to transitions 5D4→7F6, 5D4→7F5, 5D4 →7F4, and 5D4→7D3 was seen when excited by excitation wavelength 288 nm. TL glow curves for ZrO2:Tb3+ exhibit a glow curve with a well-defined peak centered in around 170°C. TL signal as a function of dopant concentration showed a maximum at 10 at%. The best intensity of TL response as a function of UV radiation wavelength was in 230 nm. TL response fading and reusability were also analyzed. The ZrO2:Tb3+ films has been found to have simple and sharp glow peak which should be considered for dosimetric applications.

This paper describes the design of a prototype telecare system, which allows to provide home care to patients with mild cognitive impairment and thus ensures their permanence in their usual environment. Telecare is oriented towards people who require constant attention due to conditions of advanced age, illness, physical risk or limited capabilities. Telecare offers these people a greater degree of independence. QFD methodology is used to develop electronic devices intended to monitor the environment and physiological state of the user continuously, providing communication between the telecare system and a monitoring center in order to take the most appropriate actions in any abnormal event.

There are many applications of the close approach maneuvers in astronautics, and several missions used this technique in the last decades. In the present work, those close approach maneuvers are revisited, but now considering that the spacecraft passes around an oblate planet. This fact changes the distribution of mass of the planet, increasing the mass in the region of the equator, so increasing the gravitational forces in the equatorial plane. Since the present study is limited to planar trajectories, there is an increase in the variation of energy given by the maneuver. The planet Jupiter is used as the body for the close approach, but the value of J2 is varied in a large range to simulate situations of other celestial bodies that have larger oblateness, but the same mass ratio. This is particularly true in recent discovered exoplanets, and this first study can help the study of the dynamics around those bodies.

International audience; The thermal deformation of a liquid nitrogen cooled silicon crystal under increasing absorbed power undergoes five phases: i) no deformation at zero power, ii) concave shape of the crystal, iii) appearance of a central bump, iv) minimum of the slope error averaged over the beam footprint on the crystal due to the balance between the initial concave shape and the growing central bump, and v) rapid growth of the thermal bump. In general, a liquid nitrogen cooled silicon crystal is designed to operate before the appearance of phase v), and mostly in phase ii) ( concave shape). This concave shape of the crystal leads to a focusing effect on the beam, which should be considered in combination with other optical elements in the design and optimization of the beamline optical layout

In this paper we present the results of the synthesis of GaN in an AP-MOVPE system heated by infrared lamps starting from gallium nitride films obtained by nitridation of gallium arsenide. Although dependence of the characteristics of the different parameters of the deposition process on the properties of the layers has been widely studied, the influence of the nature and design of the heating source has been only scarcely reported. We show that the ratio between the two phases depends on the characteristics of the heating source, as well as on other growth parameters. Our results show a compromise between the characteristics of the photoluminescence spectra, the surface morphology and the cubic phase to hexagonal phase ratio. The growth conditions can be adjusted for optimal performance.

The MINOS experiment has the potential to observe electron neutrino appearance for a set of oscillation parameters that has not been excluded by the CHOOZ experiment. However, the observation of this hypothetical signal relies on an accurate understanding of the backgrounds. In order to understand the backgrounds, an analysis of the MINOS near detector energy spectrum, which contains no oscillated signal, is utilized. The results of this analysis can then be extrapolated to the far detector to yield the background estimate. The details of the signal versus background separation methods and the results of this near detector analysis are discussed.