Application of Rice’s theory to recurrence statistics of concentration fluctuations in dispersing plumes

Rice’s theory for the statistical properties of random noise currents has been employed in the context of concentration fluctuations in dispersing plumes. Within this context, the theory has been extended to calculate the distribution of excursion times above a small threshold for arbitrary spacings between an up-crossing and the successive down-crossing. This approach has then been applied to a second-order stochastic model for the evolution of odour concentrations and their time derivative (simple model), and to the superstatistics extension of this model [Reynolds (2007) Phys. Fluids]. In agreement with the measurements of Yee and coworkers [Yee et al. (1993) Boundary-Layer Meteorol. 65, Yee et al. (1994) J. Appl. Meteorol. 33 ], both formulations predict a distribution of excursion times that can be well approximated by a power-law profile with exponent close to −3/2. For the superstatistical model the power-law profile extends over approximately three or more decades, for the simple model this range is smaller. Compared to the simple model, predictions for the superstatistical model are in a better agreement with the measurements.     

Monitoring the toxicity of phenolic chemicals to activated sludge using a novel optical scanning respirometer.

This paper reports the development of optical scanning respirometer for determining the toxicity of chemicals to activated sludge. The respirometer is used to measure the dissolved oxygen concentration by monitoring the luminescence intensity of ruthenium dye immobilized in a polymer film in contact with the wastewater sample. The intensity is related to the extent of oxygen quenching of luminescence. The toxicity of chemicals can be evaluated by measuring the inhibition on respiration rate of microorganism using the scanning respirometer. The IC50 values (concentration of a chemical that exhibits 50% respiration inhibition) of various phenolic chemicals in activated sludge were determined. The performance of this method is compared with other toxicity methods. The experimental results indicate that the reproducibility and sensitivity of this respirometer are reasonably good.     

CHEMICAL CONSTITUENTS IN STORM FLOW VS. DRY WEATHER DISCHARGES IN CALIFORNIA STORM WATER CONVEYANCES1

ABSTRACT: This research evaluated concentration data for selected water quality parameters in selected California urban separate storm sewer systems during storm event discharges and during dry weather conditions. We used existing monitoring data from multiple regulatory agencies and municipalities originally collected for compliance or local characterization, which allowed systematic assessment of seasonal patterns over a wide region. Long term mean concentration for most parameters in most streams was higher during storm discharges than during dry weather flows to at least 95 percent confidence in 20 of 45 comparative evaluations, and lower statistical confidence in 22 other comparisons. Some regional differences emerged: in four evaluated streams in the San Francisco Bay Area, total concentration of lead, copper and zinc were lower during dry weather than during storm flows to at least 99.9 percent confidence, with only one exception; while the other four evaluated California streams showed the same tendency, but to much lower statistical confidence.     

活性污泥驯化技术与高浓度CTMP废水生物处理的研究

为探讨活性污泥处理高浓度ＣＴＭＰ制浆造纸废水,研究了活性污泥驯化工艺的良性对生物系统污泥沉降性能及处理效果产生的影响。３个月多的运行试验结果表明,改良后的污泥驯化工艺即间歇式与连续式进料相结合的污泥驯化工艺能够明显改善污泥沉降性能,污泥的ＳＶ３０为２９９０－３２０ｍｇ／Ｌ,ＳＶＩ为４８－５５ｍｌ／ｇ,并显著增加处理效果,ＣＯＤ去除率７７％－８５％,ＢＯＤ５去除率９０％－９５％,ＴＳＳ去除率７５％－     

Social influences on expressed willingness to pay: results of a deliberative monetary valuation study in Colombia

Deliberative monetary valuation (DMV) methods can support environmental decision making by enabling the exchange of arguments and information to produce more democratic outcomes. The product of a valuation may be an array of expressions of willingness to pay (WTP) by individuals or a collectively agreed monetary value. Concerns have been raised, however, as to whether this product is an outcome of thoughtful and independent decision-making or influenced by social pressures to conform. Our study examines this issue and addresses concerns about the use of DMV, based on a public deliberation of forest conservation in Colombia. We analyzed the impacts of social conformity on WTP under two different decision scenarios: individual and collective. The results suggest that the impacts of social conformity are greater when a collective decision is required. These findings indicate that tensions between the differing goals of DMV could undermine its democratic promise.     

Chemically coupled microwave and ultrasonic pre-hydrolysis of pulp and paper mill waste-activated sludge: effect on sludge solubilisation and anaerobic digestion

The effects of alkali-enhanced microwave (MW; 50–175 °C) and ultrasonic (US) (0.75 W/mL, 15–60 min) pretreatments, on solubilisation and subsequent anaerobic digestion efficiency of pulp and paper mill waste-activated sludge, were investigated. Improvements in total chemical oxygen demand and volatile suspended solids (VSS) solubilisation were limited to 33 and 39 % in MW pretreatment only (175 °C). It reached 78 and 66 % in combined MW–alkali pretreatment (pH 12?+?175 °C), respectively. Similarly, chemical oxygen demand and VSS solubilisation were 58 and 37 % in US pretreatment alone (60 min) and it improved by 66 and 49 % after US–alkali pretreatment (pH 12?+?60 min), respectively. The biogas yield for US 60 min–alkali (pH 12)-pretreated sludge was significantly improved by 47 and 20 % over the control and US 60 reactors, respectively. The biogas generation for MW (150 °C)–alkali (pH 12)-pretreated sludge was only 6.3 % higher than control; however, it was 8.3 % lower than the MW (150 °C) reactor, which was due to the inhibition of anaerobic activity under harsh thermal–alkali treatment condition.     

Novel mutation and prenatal sonographic findings of glutaric aciduria (type I) in two Taiwanese families

Glutaric aciduria type I (GA I) is an autosomal recessively inherited inborn error with a defect of the enzyme glutaryl-CoA dehydrogenase (GCDH), which has never been diagnosed prenatally in Taiwanese patients. We present the prenatal sonographic findings and mutational analysis data of three children in two Taiwanese families. One patient from each family was diagnosed postnatally due to macrocephaly and neurological deterioration at 4 months and 10 months, respectively. The third child, sister of the first patient, was diagnosed prenatally at 11 weeks' gestation through chorionic villus sampling (CVS). Molecular analysis revealed that the fetus and child in Family 1 were homozygous for a common mutation, IVS10 -2A>C, which has not been reported in the Caucasian population. The patient in Family 2 was a compound heterozygote for IVS10 -2A>C and a novel mutation 749T>C (L238P). After genetic counseling, the couple decided to continue the second pregnancy. However, dilatation of quadrigeminal cistern (QC) and suspicious macrocephaly were noted at 30 weeks. Progressive dilatation of the QC associated with macrocephaly, fronto-temporal atrophy and wide space of perisylvian fissure were found in the follow-up scans. The affected girl was delivered at 37 weeks' gestation by cesarean section. Postnatal magnetic resonance imaging (MRI) studies confirmed the prenatal sonographic findings. With prenatal sonographic findings and mutational analysis presented in the present cases, the feasibility of prenatal diagnosis of GA I in high-risk pregnancy can not be overlooked. Copyright © 2002 John Wiley & Sons, Ltd.     

First-trimester prenatal diagnosis of spinal muscular atrophy using microsatellite markers

Twenty-five pregnancies at risk for spinal muscular atrophy I (SMA I) have been monitored by first-trimester prenatal diagnosis. Microsatellite markers were used in all cases to amplify polymorphic regions at the D5S125, D5S435, D5S39, D5S127, and D5S112 loci. All families, including 12 SMA I pedigrees with a deceased index child, were fully informative for DNA analysis. Three fetuses were predicted to be affected and 22 fetuses were predicted to be unaffected. Twenty-two newborns were unaffected by clinical examination at birth. These results support the accuracy of SMA I prenatal diagnosis based on linkage analysis.     

First trimester prenatal diagnosis of Sanfilippo disease (MPSIII) type B

Two pregnancies of a family at risk for Sanfilippo disease type B were monitored in the first trimester. In one case an affected fetus was diagnosed on chorionic villi by the assay of N-acetyl-a-D -glucosaminidase and confirmed on cultured fibroblasts from the aborted fetus. Pathological findings are also reported and compared with changes observed later in life. The disease was excluded in the second pregnancy.