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331.
Denise M. Cutillo MS Elizabeth A. Hammond Suzanne L. Reeser Melissa A. Kershner Barbara Lukin Lynn Godmilow Alan E. Donnenfeld 《黑龙江环境通报》1994,14(5):327-332
Prenatal diagnosis choices were reviewed in 473 women who presented for genetic counselling prior to 11 weeks' gestation for the indication of advanced maternal age. Group A consisted of 336 patients who were unaware of a possible association between chorionic villus sampling (CVS) and limb defects. Group B consisted of 137 patients who were provided this information. Fifty-one per cent of patients in group A and 45 per cent of patients in group B chose CVS. This difference was not significant by χ2 analysis (P = 0·7). Patterns of prenatal diagnosis procedure utilization from 1987 to 1992 revealed a significant reduction in CVS utilization accompanied by a corresponding increase in amniocentesis after the association between CVS and limb defects was publicized. Referrals for CVS counselling also significantly declined. However, acceptance rates did not change for those patients who received genetic counselling. First-trimester genetic counselling, including a discussion regarding a possible association between CVS and limb defects, helps patients make informed decisions concerning prenatal diagnosis options, and, in our population, resulted in no change in CVS acceptance rates. 相似文献
332.
Marco Antonio Leonel Caetano Douglas Francisco Marcolino Gherardi 《Ecological modelling》2011,222(15):2835-2840
The Brazilian government has already acknowledged the importance of investing in the development and application of technologies to reduce or prevent CO2 emissions resulting from human activities in the Legal Brazilian Amazon (BA). The BA corresponds to a total area of 5 × 106 km2 from which 4 × 106 km2 was originally covered by the rain forest. One way to interfere with the net balance of greenhouse gases (GHG) emissions is to increase the forest area to sequester CO2 from the atmosphere. The single most important cause of depletion of the rain forest is cattle ranching. In this work, we present an effective policy to reduce the net balance of CO2 emissions using optimal control theory to obtain a compromising partition of investments in reforestation and promotion of clear technology to achieve a CO2 emission target for 2020. The simulation indicates that a CO2 emission target for 2020 of 376 million tonnes requires an estimated forest area by 2020 of 3,708,000 km2, demanding a reforestation of 454,037 km2. Even though the regional economic growth can foster the necessary political environment for the commitment with optimal emission targets, the reduction of 38.9% of carbon emissions until 2020 proposed by Brazilian government seems too ambitious. 相似文献
333.
334.
Carlos Agudelo Francisco Morant Anglada Eduardo Quiles Cucarella Emilio García Moreno 《Journal of Loss Prevention in the Process Industries》2013,26(4):660-665
In this paper we show the integration of techniques for early fault detection and diagnosis of operational faults in industrial processes, and we show an application example in a Fluid Catalytic Cracking refinery process. The early fault detection and diagnosis allow the operators in an industrial process to take the best actions during the real state of the process, avoiding incipient faults to scale to critical situations where there is risk of human lives and economical lost. 相似文献
335.
Francisco Rebelo Correia da Silva Waldemar Karwowski 《International journal of occupational safety and ergonomics》2013,19(4):509-519
AbstractThis study reports on the development and validation of a new computer model for simulating human postures at work, and assessing the reaction forces and bending moments in 43 human articulation joints. The proposed model estimates the intradiscal pressure in the vertebral column in response to external loading forces encountered during human interactions with work objects or processes. The model was implemented in a self-contained interactive software package. The simulation results compare favorably with the reported experimental data, and provide reasonable confidence in the quality of the model. Its characteristics and its applications in evaluating physical task performance are also discussed 相似文献
336.
Wastewater treatment with a double-layer submerged biological aerated filter,using waste materials as biofilm support 总被引:7,自引:0,他引:7
The aim of this research was to determine the performance of a submerged biological aerated filter, composed of a double-layer bed. This bed is made up of a top layer of ceramic material and a bottom layer of plastic material (both from previously used waste material). Effluent concentrations are presented related to the volumetric and hydraulic loads applied. The results were very satisfactory. If effluent concentrations of under 20 mg TBOD5/L and 25 mg SS/L are to be achieved, 4.87 kg TBOD5/m3/d and 3.0 kg SS/m3/d could be applied, respectively. For that maximum TBOD5 volumetric load that can be applied, a very reasonable consumption value of 1.0 kg O2/kg TBOD5, eliminated was obtained. The counter-current flow system outperformed the co-current flow system with respect to TBOD5 and SS removal. The tests were performed at a pilot plant with full scale height. The influent used was primary effluent of a conventional treatment plant. A multivariant analysis (ANOVA) was applied to the results. 相似文献
337.
Alonso M Alguacil FJ 《Journal of the Air & Waste Management Association (1995)》2002,52(11):1342-1347
A laboratory-scale electrostatic precipitator has been designed and constructed in which the grounded collector plate has been substituted by a set of wire screens placed perpendicularly to the gas flow. Particles are deposited onto the screens by two mechanisms--electrostatic deposition and diffusional deposition--which act simultaneously. On the one hand, electrostatic deposition is effective for relatively large particles, but it is quite ineffective for the smallest ones because their charging probability in the corona field is too low. On the other hand, the diffusional collection efficiency of particles on fibers is high for small particles but low for the larger ones. Therefore, the simultaneous diffusional-electrostatic precipitation may become a useful technique for efficient filtration of particles below 0.1 microm. A preliminary experimental evaluation of this filtering device has shown that submicrometer particles with diameters down to a few nanometers can be collected with number efficiencies greater than 99%. 相似文献
338.
F. L. Leistritz PhD J. M. Halstead MS R. A. Chase MS S. H. Murdock PhD 《Environmental geochemistry and health》1982,4(4):141-150
While larger mineral resource development projects offer new jobs and provide a stimulus to the economy of the area where they are sited, they may also pose problems in rural areas associated with rapid population growth. The purpose of an impact management programme is to anticipate and alleviate project effects that are generally perceived as undesirable and to enhance effects that are beneficial to site area communities. While the effective management of project effects is the end towards which all impact assessment efforts are directed, an integrated approach to impact management has been notably lacking. This paper suggests a systems framework for meeting this need by: (1) reviewing the need for impact management efforts; (2) discussing the objectives of, and considerations in, designing impact management programmes; (3) presenting a conceptual framework for, and key components of, such a programme; and (4) suggesting an approach for implementing such a system as an integral part of the project development process. 相似文献
339.
Francisco J. Diego-Rasilla Rosa M. Luengo John B. Phillips 《Behavioral ecology and sociobiology》2005,58(4):361-365
Experiments were carried out to investigate the use of magnetic compass cues in the nocturnal homing orientation of the alpine newt Triturus alpestris. Tests were carried out at a site 9 km to the east–northeast of the breeding pond. Newts were tested at night in an outdoor circular arena that provided an unimpeded view of celestial cues, in one of four symmetrical alignments of an earth-strength magnetic field. In tests carried out under partly cloudy skies newts exhibited homeward magnetic compass orientation. Because the moon was visible in some trials, but obscured by clouds in others, we investigated whether the presence of the moon contributed to the scatter in the distribution of magnetic bearings. When the moon was visible, the distribution of magnetic bearings was more scattered than when the moon was obscured by clouds, although in neither case was the distribution significant due, in part, to the small sample sizes. Moreover, when the moon was visible, newts oriented along a bimodal axis perpendicular to the moon azimuth, suggesting that the presence of the moon may have affected the newts behavior. To provide a more rigorous test of the role of magnetic compass cues when celestial cues were unavailable, nocturnal tests were carried out during the following migratory season under total overcast. In the absence of celestial compass cues, the distribution of magnetic bearings exhibited highly significant orientation in the homeward direction. These findings indicate that newts are able to orient in the homeward direction at night using the magnetic compass as the sole source of directional information. Moon light altered the newts behavior. However, this apparently resulted from the asymmetrical distribution of moon light in the testing arena, rather than the use of an alternative compass. 相似文献
340.