Radiation and Dust Sensor for Mars Environmental Dynamic Analyzer Onboard M2020 Rover.

The Radiation and Dust Sensor is one of six sensors of the Mars Environmental Dynamics Analyzer onboard the Perseverance rover from the Mars 2020 NASA mission. Its primary goal is to characterize the airbone dust in the Mars atmosphere, inferring its concentration, shape and optical properties. Thanks to its geometry, the sensor will be capable of studying dust-lifting processes with a high temporal resolution and high spatial coverage. Thanks to its multiwavelength design, it will characterize the solar spectrum from Mars' surface. The present work describes the sensor design from the scientific and technical requirements, the qualification processes to demonstrate its endurance on Mars' surface, the calibration activities to demonstrate its performance, and its validation campaign in a representative Mars analog. As a result of this process, we obtained a very compact sensor, fully digital, with a mass below 1 kg and exceptional power consumption and data budget features.

[Warning signs and symptoms on obstetric care. About their knowledge in women]. / Signos y síntomas de alarma obstétrica. Acerca del conocimiento que tienen las mujeres.

BACKGROUND: maternal mortality is caused by delays in recognizing complications at the medical facility. Maternal mortality increased during 2009 in Guanajuato, reflecting deficiencies in the care process. The objective was to determine the knowledge about signs and symptoms that pregnant and non-pregnant patients considered as obstetric emergency data during pregnancy, childbirth and postpartum. METHODS: a descriptive and comparative study in 150 pregnant and 150 non pregnant women aged 18 to 40 years was performed. A structured questionnaire was applied. The statistical analysis was performed in NCSS 2007 program. RESULTS: alarm sign and symptoms during pregnancy were identified by 72.2 % of the non-pregnant; at birth 54.4 % and 46.2 % in puerperium. The 92.9 % of pregnant women identified alarm sign and symptoms during pregnancy, during childbirth only 62.7 % and in postpartum 25 %. There was an association between previous pregnancy and knowing alarm signs and symptoms and the number of inquiries received. CONCLUSIONS: knowing the warning signs is related to previous obstetrical deliveries and by the educational work of the family physician during prenatal care.

Solar photo-degradation of aniline with rGO/TiO2 composites and persulfate.

The solar photodegradation of aniline using reduced graphene oxide-based composites (rGO/TiO2) and different electron acceptors such as H2O2 and persulfate (PS) has been studied. To this end, an innovative self-sufficient drum reactor (operating with solar irradiation and artificial UV light) has been employed. The role of radicals and the new graphene morphology is evaluated. Finally, changes in the degradation/mineralization mechanism are explained according to intermediates evolution (obtained from mass spectroscopy). In the Solar/rGO/TiO2/H2O2 system, hydroxyl radicals react with the reduced graphene oxide (rGO) producing oxidized rGO (OrGO). The process creates new pores increasing surface area favouring adsorption. Also, other radicals such as superoxide or singlet oxygen are also formed, affecting the degradation mechanism. The hole reacts with adsorbed aniline to form the aniline-radical-cation. Nitrosobenzene is then formed with the active participation of superoxide radical anion, finally yielding azobenzene. It was found that the addition of 2.5% wt of rGO increases mineralization from 0 to 14% during the solar stage after 120 min, reaching 82.5% when lamps are switched on after 240 min. On the other hand, activation of PS with UV-C light is a very efficient process, since aniline is wholly degraded in 10-20 min depending on PS initial concentration, reaching a high mineralization degree close to 90% in 120 min. During this process, degradation occurs in a very different route, via the formation of phenol. In the first stage (t < 25 min), sulfate radical is the primary oxidant involved to yield benzoquinone. In a second step (t > 25 min), hydroxyl radicals play the leading role to reach C2-C6 organic acids.

Operation costs of the solar photo-catalytic degradation of pharmaceuticals in water: A mini-review.

The removal of pharmaceuticals present in wastewater is receiving more and more attention since most of them are refractory to traditional biological treatments. Many advanced oxidation processes have been reported in literature. However, cost estimations are not available for most of them. Recently, more environment friendly processes using solar radiation are gaining importance. The solar photo-Fenton process has been used with different reactor configurations and scales and seems to be the most promising technology for reducing operation costs. In addition, the use of ferrioxalate-aided systems allows the use of pHs close to neutrality, that reduces costs before disposal (not calculated here). The possible use of photovoltaic panels for an energy-free process makes it very interesting for an economic evaluation. Results for the homogeneous solar photo-Fenton process show that when pure compounds are present in water, mineralization is in the range 18-21% with an estimated operation cost of 0.739-0.85 €/m3. An increase in mineralization up to 60-80.6% requires either the use of ferrioxalate (slightly increasing costs to 1.1-1.56 €/m3) or the addition of very high concentration of H2O2, that rises costs substantially. The presence of pharmaceuticals in a Waste Water Treatment Plant effluent reduces mineralization (maximum of 20%) also increasing costs. On the other hand, published results confirm that heterogeneous photocatalysis with TiO2 (both suspended or immobilized) is still far to compete with homogeneous photo-Fenton process in operation costs. The development of new reactor systems and modified photo-catalysts are needed to compete as an efficient applicable technology in the near future.

A novel combined solar pasteurizer/TiO2 continuous-flow reactor for decontamination and disinfection of drinking water.

A new combined solar plant including an annular continuous-flow compound parabolic collector (CPC) reactor and a pasteurization system was designed, built, and tested for simultaneous drinking water disinfection and chemical decontamination. The plant did not use pumps and had no electricity costs. First, water continuously flowed through the CPC reactor and then entered the pasteurizer. The temperature and water flow from the plant effluent were controlled by a thermostatic valve located at the pasteurizer outlet that opened at 80 °C. The pasteurization process was simulated by studying the effect of heat treatment on the death kinetic parameters (D and z values) of Escherichia coli K12 (CECT 4624). 99.1% bacteria photo-inactivation was reached in the TiO2-CPC system (0.60 mg cm-2 TiO2), and chemical decontamination in terms of antipyrine degradation increased with increasing residence time in the TiO2-CPC system, reaching 70% degradation. The generation of hydroxyl radicals (between 100 and 400 nmol L-1) was a key factor in the CPC system efficiency. Total thermal bacteria inactivation was attained after pasteurization in all cases. Chemical degradation and bacterial photo-inactivation in the TiO2-CPC system were improved with the addition of 150 mg L-1 of H2O2, which generated approximately 2000-2300 nmol L-1 of HO● radicals. Finally, chemical degradation and bacterial photo-inactivation kinetic modelling in the annular CPC photoreactor were evaluated. The effect of the superficial liquid velocity on the overall rate constant was also studied. Both antipyrine degradation and E. coli photo-inactivation were found to be controlled by the catalyst surface reaction rate.