微量元素对牛粪低温厌氧发酵的影响

为考察较低温度(<17℃)条件下添加微量金属元素对厌氧发酵产气量的影响,在发酵底物TS(含固率)为10%下采用10 L玻璃瓶作反应器,以牛粪为原料,向厌氧生物反应器中分别添加MnSO4、FeSO4·7H2O、电解锰渣,分析了厌氧消化系统运行过程中的产气量、COD(化学需氧量)和pH的变化。结果表明,锰元素能促进低温下牛粪的厌氧发酵,加速反应启动。当添加6 g MnSO4、100 g电解锰渣时,单位质量VS产气率分别为0.26 mL/g和0.64 mL/g,添加6 g FeSO4·7H2O与空白对照组均未见明显产气。     

Comprehensive temperature monitoring in an in-vessel forced-aeration static-bed composting process

Comprehensive temperature monitoring was done in an in-vessel forced-aeration static-bed composting process using sewage sludge. The three layers that divided the compost pile horizontally showed different temperature distributions. The temperature of the top layer appeared not to be influenced by the ambient temperature. The temperature of the center area of the top layer was taken to be the representative temperature for evaluating composting start-up performance. The temperature of the bottom layer was strongly influenced by the ambient temperature, and the temperature of the center area of the bottom layer was taken to be the representative temperature for pathogen control as it was the minimum temperature in the reactor. Composting start-up performance was influenced by several factors when the ambient temperature was either below or above 20°C. When the ambient temperature was below 20°C, the time taken to reach 65°C (T ₆₅) was influenced by the temperature of inflowing air, but when the temperature was higher than 20°C, it was influenced by the ratio of sewage sludge to seed compost (F/S). T ₆₅ was least when F/S was 1–2. Received: January 9, 2001 / Accepted: October 10, 2001     

Modeling of n-butane ignition, combustion, and preflame oxidation in the 20-l vessel

The objective of the study reported herein is to simulate various physical and chemical phenomena accompanying fuel-rich n-butane–oxygen mixture preparation, ignition, preflame oxidation, and combustion in the standard 20-l explosion vessel, by applying mathematical models. Based on the computational fluid dynamics (CFD) simulations of the mixing process and natural convection of the ignition kernel, as well as on the analysis of the detailed reaction mechanism of n-butane oxidation, laminar flame propagation, and self-ignition, possible explanations for the phenomena observed experimentally have been suggested. The results of the study indicate that seemingly inflammable mixtures can become hazardous depending on the mixture preparation procedure and forced ignition timing.     

Prenatal diagnosis and fetal pathology of partial trisomy 20p–monosomy 4p resulting from paternal translocation

Amniocentesis was performed in view of a paternal balanced chromosomal rearrangement t(4;20)(p16;p12), inv(18)(p11q11). The pregnancy was complicated by severe oligohydramnios. The fetal karyotype was unbalanced: 46XX, der(4), t(4;20)(p16;p12), inv(18) (p11q11)pat., thus resulting in partial trisomy 2Op and monosomy 4p. In addition, the amniotic fluid alpha-fetoprotein (AFP) became increasingly elevated with gestational age. The pregnancy was terminated at 25 weeks. The fetus presented with typical facial dysmorphic features, unilateral cleft lip and palate, severe renal hypoplasia, consistent with the 4p- (Wolf-Hirschhorn) syndrome.     

Partial trisomy 20p resulting from recombination of a maternal pericentric inversion: case report of a prenatal diagnosis by chorionic villus sampling

We report a case of prenatal diagnosis of trisomy 20p resulting from a maternal pericentric inversion. The diagnosis was confirmed on both chorionic villi and amniotic cells. This case underlines the fact that prenatal ultrasound diagnosis of this structural anomaly is difficult. The only early sonographic feature was increased nuchal translucency. Copyright © 2006 John Wiley & Sons, Ltd.     

Non-mosaic trisomy 20 presenting at 21 weeks' gestation as a thoraco-abdominal mass

Non-mosaic trisomy 20 is rare in fetuses surviving beyond the first trimester. We report a case of a fetus with non-mosaic trisomy 20 in amniotic fluid cultures obtained during the prenatal evaluation of an unusual thoraco-abdominal mass which was found at autopsy to be pulmonary sequestration. Gross inspection and autopsy of the fetus revealed multiple anomalies. Copyright © 2001 John Wiley & Sons, Ltd.     

Ecosystems and human health: The local benefits of forest cover in Indonesia

This paper documents the effect of primary forest cover loss on increased incidence of malaria. The evidence is consistent with an ecological response. I show that land use change, anti-malarial programs or migration cannot explain the effect of primary forest cover loss on increased malarial incidence. Falsification tests reveal that the effect is specific to malaria, with forest cover having no discernible effect on other diseases with a disease ecology different from that of malaria. Back-of-the-envelope calculations indicate that the morbidity-related malaria-reducing local benefits of primary forests are at least $1-$2 per hectare.     

The ecological insurance trap

Common pool resources often insure individual livelihoods against the collapse of private endeavors. When endeavors based on private and common pool resources are interconnected, investment in one can put the other at risk. We model Senegalese pastoralists who choose whether to grow crops, a private activity, or raise livestock on common pool pastureland. Livestock can increase the likelihood of locust outbreaks via ecological processes related to grassland degradation. Locust outbreaks damage crops, but not livestock, which are used for savings and insurance. We show the incentive to self-protect (reduce grazing pressure) or self-insure (increase livestock levels) changes with various property rights schemes and levels of ecological detail. If the common pool nature of insurance exacerbates the ecological externality even fully-informed individuals may make risk management decisions that increase the probability of catastrophe, creating an “insurance trap.”     

CEO education and corporate environmental footprint

We analyze the effect of CEO education on environmental decision-making. Using a unique sample of Danish firms from 1996 to 2012, we find that CEO education significantly improves firms' energy efficiency. We seek to derive causality using health shocks: the hospitalization of highly educated CEOs induces a drop in energy efficiency, whereas the hospitalization of less educated CEOs does not have any significant effect. Exploring the mechanisms at play, we show that our results are largely driven by advanced education in business degrees. Moreover, we show that CEO education is associated with greater environmental awareness: highly educated CEOs exhibit greater concerns for climate change, as measured by a survey of social preferences, and drive more environmentally efficient cars. Taken together, our findings suggest that education shapes managerial styles giving rise to greater sustainability in corporate actions.