Aeromyocological survey in the Santiago Western district (author''s transl)

It has not been determined whether Rho (D)-negative infants born of Rho (D)-positive mothers are sensitized during gestation or during parturition. Sensitization before use precludes the efficacious use of human Rho immune globulin as a prophylactic. The purpose of the present study is to identify the time of sensitization. Cord blood was collected from the placentas of 68 Rho (D)-negative infants whose mothers were Rho (D)-positive. Sixty-three of the 68 infants had one blood sample obtained between 1 and 9 months later. The paired samples were analyzed for anti-D by standard Coombs test and by automated antibody detection techniques. With the technique of automated antibody detection, we have been unable to demonstrate antibody in cord blood of the Rho (D)-negative infants of whom at least 7 of 63 (11%) had detectable anti-D between 1 and 9 months of age. These data show that Rho (D)-negaitve infants do not have detectable antibody at birth but may develop detectable anti-D in the first months of life. This observation suggests that the sensitizing dose of Rho (D) antigen occurs at parturition rather than during gestation.     

CRONE control of continuous linear time periodic systems: application to a testing bench

Frequency methods only are used here for the study and control of continuous linear time periodic systems. Using time varying frequency responses defined by L. A. Zadeh in the 1950s, the second generation CRONE control is extended to the control of linear time periodic systems. This control strategy ensures, for the closed-loop system, a near stationary behavior, performances set by the designer, and robustness of performances to gain variations of the plant. An application of the proposed control strategy to a testing bench shows its efficiency.     

Rationalizing the Effect of the MAA/PEGMA Ratio of Comb-Shape Copolymers Synthetized by Aqueous Free-Radical Copolymerization in the Hydration Kinetics of Ordinary Portland Cements

Methacrylic acid-co-poly(ethylene glycol methacrylate) (MAA-co-PEGMA) copolymers (MPEG-type polycarboxylate ether (PCE) superplasticizers) are characterized by a comb-like structure. Although they have been used for years as dispersants in cementitious formulations, their structure–property relationship is still not fully understood. In this work, PCEs with uniform composition and different charge-density (N) or different side chain lengths (P) are synthesized by free-radical copolymerization varying the MAA/PEGMA ratios and ethylene oxide units in the PEGMA macromonomers. The effect of these copolymers on the hydration kinetics of an Ordinary Portland Cement (OPC) is analyzed, and it is observed that by increasing the PCE concentration the hydration is delayed. For a given PCE concentration, the delay is longer as the MAA/PEGMA ratio increases or the side chain length of the PEGMA decreases. The hydration delay is proportional to the carboxylate dosage and all PCEs fit in a master curve proving that the microstructure of the PCEs synthesized by free-radical copolymerization can be correlated with the hydration delay of a commercial OPC.     

亨克尔HE-219 “UHU”

正板件包含大量的灰色塑料件以及丰富的内构例如无线电,座椅,武器等。机身被完美的复原了。引擎的刻画也十分出色。机头的FuG 220无线电天线开的很不错,不过我依然还是用了Master Model的金属件取代了原始板件,主要是因为金属件的材质可以更好的还原真实的天线。非常推荐。     

Kinetic study of the catalytic reforming of biomass pyrolysis volatiles over a commercial Ni/Al2O3 catalyst

An original kinetic model has been proposed for the reforming of the volatiles derived from biomass fast pyrolysis over a commercial Ni/Al₂O₃ catalyst. The pyrolysis-reforming strategy consists of two in-line steps. The pyrolysis step is performed in a conical spouted bed reactor (CSBR) at 500 °C, and the catalytic steam reforming of the volatiles has been carried out in-line in a fluidized bed reactor. The reforming conditions are as follows: 600, 650 and 700 °C; catalyst mass, 0, 1.6, 3.1, 6.3, 9.4 and 12.5 g; steam/biomass ratio, 4, and; time on stream, up to 120 min. The integration of the kinetic equations has been carried out using a code developed in Matlab. The reaction scheme takes into account the individual steps of steam reforming of bio-oil oxygenated compounds, CH₄ and C₂-C₄ hydrocarbons, and the WGS reaction. Moreover, a kinetic equation for deactivation has been derived, in which the bio-oil oxygenated compounds have been considered as the main coke precursors. The kinetic model allows quantifying the effect reforming conditions (temperature, catalyst mass and time on stream) have on product distribution.     

Passive-sampler derived air concentrations of persistent organic pollutants on a north-south transect in Chile

Passive air samplers consisting of polyurethane foam (PUF) disks, were deployed in six locations in Chile along a north-south transect to investigate gas-phase concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). The study provides new information on air concentrations of these persistent organic pollutants (POPs) which is lacking in this region. It also provides insight into potential sources and long-range transport (LRT). The samplers were deployed for a 2-month period in five remote sites and one site in the city of Concepción. Mean concentrations (pg m(-3)) for sigmaPCB were 4.7 +/- 2.7 at remote sites and 53 +/- 13 in Concepción. PCB levels at remote sites were related to proximity to urban source regions and/or air back trajectories. With the exception of endosulfan I, mean concentrations (pg m(-3)) of OCPs at background sites were consistently low: 5.4 +/- 1.4 for alpha-HCH, 7.0 +/- 1.1 for gamma-HCH, 2.5 +/- 0.5 for TC, 2.5 +/- 0.6 for CC, 1.9 +/- 1.2 for dieldrin, and less than 3.5 for toxaphene. Endosulfan I showed a decreasing concentration gradient from 99 to 3.5 pg m(-3) from the north to south of Chile. Concentrations of OCPs in the Concepción City were generally 10-20 times higher than at the background sites suggesting continued usage and/or re-emission from past use. For instance, at remote sites, the alpha/gamma ratio (0.76) was typical of background air, while the ratio in Concepción (0.12) was consistent with fresh use of gamma-HCH. Levels of sigmaPBDEs were below the detection limit of 6 pg m(-3) at all sites.     

Optimal economic exploitation of hydrogen based grid-friendly zero energy buildings

This paper presents economically optimized energy and power management strategies for grid-friendly hydrogen based Zero Energy Buildings (ZEBs). The proposed energy management strategy is an adaptative optimization-based strategy that minimizes the operation cost of the facility taking into account RES generation prediction errors. It is shown that with an Adaptative Optimized Five-step Charge Controller (AOFC2) the use of the different equipment is optimized and the overall operation cost is minimized considering the entire life of the facility. The proposed energy management strategy is coordinated with power management strategies to offer advanced functionalities (peak-shaving, reactive power control and back-up service) that provide added-value to the facility. The paper demonstrates by means of offline and real-time simulations, that an adequate energy and power management structure permits the optimal economic exploitation of an advanced ZEB (that includes an energy storage system), providing not only a zero energy annual balance but also interesting added-value features to the grid and to the local consumers.