HYDROLOGIC DESIGN CONSIDERATIONS OF CONSTRUCTED WETLANDS FOR URBAN STORMWATER RUNOFF1

ABSTRACT: The successful design of constructed wetlands requires a continuous supply of water or vegetation that can withstand drought conditions. Having a constant water source is the best alternative to insure species diversity throughout the season. Consequently, detention structure designs should be based on times between events as well as on hydrologic return periods, since between events is when most evaporation and infiltration losses are likely to occur. In arid or semi-arid environments, this is a difficult process because of long interevent times and seasonal changes in precipitation patterns. This discussion is predicated on the assumption that phytoplankton, epiphytic algae, and emergent vegetation require moist conditions to be effective at removing nutrients, metals and other pollutants. There are drought tolerant species of vegetation that can be used in constructed wetlands but it may take several days to re-establish the attached bacteria communities necessary for optimum pollutant removal. This paper examines a stochastic framework to examine the probability of extended dry periods based on historic rainfall data. The number of consecutive dry days is selected for a specified level of assurance. By multiplying this value by the sum of daily system losses, an overall pond volume can be determined that ensures a minimum depth of water. To illustrate the utility of the approach, the method is applied to a site in Spokane, Washington.     

碳纤维复合芯铝导线张力架线施工技术

在宁夏大坝—青铜峡甲、乙、丙220 kV输电线路增容改造工程中,为了解决JRLX/T-350/40碳纤维复合芯导线施工中出现的芯棒内缩、芯棒断裂、导线松股和外层铝股损伤等问题,通过对导线结构及特性分析,采用缩短放线段、分散压接、改变导线连接工艺、投入大轮径张力机和放线滑车等方法,优质地完成了线路改造施工。结果表明:该施工技术完全满足碳纤维复合芯导线施工要求,改造后线路的输电能力及事故情况下抵御风险的能力成倍提高,满足了电网安全稳定供电的需要。     

活性炭管吸附气相色谱法测定工作场所中环氧丙烷、环氧氯丙烷

建立了一种利用活性炭管采样,二硫化碳洗脱,DB-624UI气相色谱柱(30 m×0.25 mm×1.4μm)进行分离,FID检测器检测的测定环氧丙烷和环氧氯丙烷的气相色谱方法。结果显示,环氧丙烷和环氧氯丙烷在0.5~50 mg/L范围内线性关系良好,方法检出限达到了0.026 mg/m3和0.048 mg/m3(以采集4.5 L空气样品计);环氧丙烷平均解析效率84.84%(RSD=1.770),环氧氯丙烷平均解析效率92.07%(RSD=2.270),适用于工作场所中环氧丙烷和环氧氯丙烷的同时测定。     

Assessment of the environmental impact of artificial effluent lagoon in Jiayuguan City of China

An artificial effluent lagoon for storing wastewater were excavated in Jiayuguan City since 1994. As a part of a demonstration project of Sino-Austmlia cooperation, an assessment of the environmental impact of the lagoon was carried out. The assessment was based on field and laboratory tests and predictive model. The main impacts from the lagoon site are likely to be on the groundwater system, and, to a lesser extent,on ambient air quality in the vicinity. Currently it is expected that groundwater is being pollutod with effluent from the effluent Ingcen. Air pollution(odor nuisance) is mainly caused by untreated effluent in the irrigation channel. The impact of high total dissolved salt(TDS) on groundwater is likely to be significant in the long run if the lagoon is continuously used. There is, consequently, no likelihood of contamination of surface water system, particularly of the city water supply system, from infiltration of effluent at the lagoon.     

Further examples of trisomy-20 mosaicism in amniotic cell cultures

Amniotic fluid cultures from two patients showed trisomy-20 mosaicism. No trisomy-20 cells were found in a normal full term infant and in multiple tissue biopsies and fetal blood from a fetus after a termination of pregnancy. No definitive advice is yet possible for parents where trisomy-20 amniotic cell mosaicism is detected. Fetoscopy and fetal blood sampling are of no value and termination of pregnancy is not indicated by empirical evidence. Preferential trophoblastic non-disjunction (Kalousek and Dill, 1983) is discussed as a possible partial explanation for the variable occurrence and distribution of this type of mosaicism.     

Do microsporidian parasites affect courtship in two-spotted gobies?

Courtship and body condition of male two-spotted gobies (Gobiusculus flavescens) harbouring naturally acquired microsporidian infections were compared with those of microsporidian-free males under standardized conditions in the lab. Although parasite infection had no apparent effect on individual condition, it significantly affected male courtship intensity. This effect, however, was affected by the intensity of the female courtship. Our study is one of the first to demonstrate a sub-lethal behavioural effect of a microsporidian parasite that could negatively affect the reproductive success of infected individuals. Our results also suggest that secondary sexual traits like courtship may be more sensitive to moderately detrimental effects of parasite infection than classical condition indices.     

Evolutionary variation in the expression of phenotypically plastic color vision in Caribbean mantis shrimps, genus Neogonodactylus

Many animals have color vision systems that are well suited to their local environments. Changes in color vision can occur over long periods (evolutionary time), or over relatively short periods such as during development. A select few animals, including stomatopod crustaceans, are able to adjust their systems of color vision directly in response to varying environmental stimuli. Recently, it has been shown that juveniles of some stomatopod species that inhabit a range of depths can spectrally tune their color vision to local light conditions through spectral changes in filters contained in specialized photoreceptors. The present study quantifies the potential for spectral tuning in adults of three species of Caribbean Neogonodactylus stomatopods that differ in their depth ranges to assess how ecology and evolutionary history influence the expression of phenotypically plastic color vision in adult stomatopods. After 12 weeks in either a full-spectrum “white” or a narrow-spectrum “blue” light treatment, each of the three species evidenced distinctive tuning abilities with respect to the light environment that could be related to its natural depth range. A molecular phylogeny generated using mitochondrial cytochrome oxidase C subunit 1 (CO-1) was used to determine whether tuning abilities were phylogenetically or ecologically constrained. Although the sister taxa Neogonodactylus wennerae and N. bredini both exhibited spectral tuning, their ecology (i.e. preferred depth range) strongly influenced the expression of the phenotypically plastic color vision trait. Our results indicate that adult stomatopods have evolved the ability to undergo habitat-specific spectral tuning, allowing rapid facultative physiological modification to suit ecological constraints.     

Hierarchical spatial modeling for estimation of population size

Estimation of population size has traditionally been viewed from a finite population sampling perspective. Typically, the objective is to obtain an estimate of the total population count of individuals within some region. Often, some stratification scheme is used to estimate counts on subregions, whereby the total count is obtained by aggregation with weights, say, proportional to the areas of the subregions. We offer an alternative to the finite population sampling approach for estimating population size. The method does not require that the subregions on which counts are available form a complete partition of the region of interest. In fact, we envision counts coming from areal units that are small relative to the entire study region and that the total area sampled is a very small proportion of the total study area. In extrapolating to the entire region, we might benefit from assuming that there is spatial structure to the counts. We implement this by modeling the intensity surface as a realization from a spatially correlated random process. In the case of multiple population or species counts, we use the linear model of coregionalization to specify a multivariate process which provides associated intensity surfaces hence association between counts within and across areal units. We illustrate the method of population size estimation with simulated data and with tree counts from a Southwestern pinyon-juniper woodland data set.     

基于小波相关分析框架的大气腐蚀数据挖掘

目的 针对大气腐蚀中腐蚀数据复杂多变且不易于分析的问题,提出一种基于小波的相关分析框架,挖掘腐蚀的变化特征及其影响因素.方法 首先采用小波功率谱确定腐蚀数据的周期波动特征,然后应用小波相干谱分析腐蚀和环境因素的相关强度、超前滞后及正反相关系,最后利用平均小波相干和显著相干百分比筛选出与腐蚀相关程度较高的环境因素.然后以青岛碳钢腐蚀数据为具体对象,挖掘了温度、相对湿度、降雨和污染物对碳钢初期腐蚀行为的影响.结果 在腐蚀初期,碳钢的腐蚀具有很强的日波动特征,温度和相对湿度是导致其波动的主要环境因素;腐蚀在降雨时刻呈现间歇性波动特征,且降雨超前于腐蚀;污染物浓度较低使得其对碳钢的腐蚀影响较弱.结论 基于小波的相关分析框架有效展现了复杂腐蚀数据的变化特征及其与环境因素的关系,为深入理解大气腐蚀规律提供了一种新的途径.