Double-Arranged Mound-Mounted Shelterbelts: Influence of Porosity on Wind Reduction between the Shelters

Using a two-dimensional LDA-System, measurements in an atmospheric boundary layer wind tunnel have been made in the intermediate field of double-arranged, mound-mounted shelterbelts. The porosity of the shelterbelts ranged from 0% to 52%. For each porosity, seven different distances of the two windbreaks between 5 and 25 times the windbreak height were investigated. The efficiency of the windbreak systems is assessed by means of protection parameters considering the change of horizontal momentum on bodies immersed in the flow, of pedestrian comfort conditions and of momentum exchange in vertical direction. Furthermore recirculation zones and the change of kinetic energy are shown. The measurement results are given in the form of contour plots indicating flow quantities and protection volumes between the two windbreaks. The shelter efficiency of the investigated windbreak systems is compared to that of adequate single line windbreaks. It is shown that for certain windbreak configurations the wind-protected area in the intermediate field of consecutively arranged windbreaks becomes larger in comparison to a single windbreak.     

Sorption of lambda-cyhalothrin,cypermethrin, deltamethrin and fenvalerate to quartz,corundum, kaolinite and montmorillonite

Sorption to mineral surfaces may be important for retention and degradation of hydrophobic pesticides in subsoils and aquifers poor in organic matter. In this work the title pyrethroids have been used to investigate selective interactions with the surfaces of four minerals. Sorption of the four pyrethroids was quantified in batch experiments with initial pyrethroid concentrations of 1–100 μg/l. Sorption to centrifuge tubes used in the batch experiments accounted for 25–60% of total sorption. Net sorption was obtained from total sorption after subtracting the amounts of pyrethroids sorbed to centrifuge tubes used. All isotherms could be fitted by the Freundlich equation with n ranging between 0.9 and 1.1. Bonding affinities per unit surface area decreased in the order: corundum>quartz>montmorillonitekaolinite. A similar sequence as found for the total surface tension of the minerals. All minerals showed the same selectivity order with respect to sorption affinity of the four pyrethroids: lambda-cyhalothrin>deltamethrin>cypermethrin>fenvalerate, which shows that the most hydrophobic compound is sorbed most strongly. Stereochemical properties of the four pyrethroid formulations may also contribute to the selectivity pattern.     

Platinum emission rate of automobiles with catalytic converters

Inconsistent data presently available on the platinum emission rate of cars in Germany equipped with catalytic converters are evaluated. Automobile sources of Pt other than autocatalysts are quantified and found to be 1–6 orders of magnitudes lower than the Pt emissions attributed to catalytic converters. A transfer of emission rates derived from test stand experiments to more realistic street conditions reaches 0.8 μg Pt/km. In this manner, data from test stand experiments and from environmental investigations meet in the range of 0.5–0.8 μg Pt/km.     

锅炉冲灰水在烟气脱硫中工艺参数的试验研究

通过实验室模拟烟气,用攀枝花市某锅炉的冲灰水进行了SO2的吸收试验。通过对SO2吸收机理、吸收工艺的分析,选取了填料、液气比、SO2入塔浓度作为试验的工艺参数。经过试验,得出了填料的材质、形状,液气比,以及SO2入塔浓度对脱硫效果的影响情况,获取了冲灰水吸收SO2的主要工艺参数。这对进一步的冲灰水吸收SO2模型研究,以及在锅炉烟气、冲灰水的环保治理工程中具有一定的指导意义。     

Seasonal ontogenetic colour plasticity in the adult striated shieldbug <Emphasis Type="Italic">Graphosoma lineatum</Emphasis> (Heteroptera) and its effect on detectability

Camouflage and warning colouration are two important forms of protective colouration. We have studied the detectability of two seasonal colourations in the aposematic striated shieldbug, Graphosoma lineatum. The typical colouration of this insect is red and black, which is also the colouration of the reproductive post-hibernation bugs in our study area in south central Sweden. However, the majority of newly eclosed adults in late summer exhibit a ‘pale’ (light brownish, non-red) and black striation, and these bugs appear quite cryptic to the human eye when sitting on the dried stems and umbels of their host plants. In experiments using photographs of prey in the late-summer habitat shown on a computer screen, we compared the time to detection by human subjects of bugs, which had been manipulated to show either of the two typical seasonal colourations. Time to detection was significantly longer for the pale and black than for the red-and-black striation in images with the bug photographed at two different distances. This indicates that the pale pre-hibernation striation may have a cryptic function. In a separate experiment, we tested detectability of striated and non-striated manipulations of bug pre-hibernation colouration against the late-summer background, and found that time to detection was significantly longer for the striated bugs. We discuss potential functional explanations for the seasonal ontogenetic colour plasticity and suggest that the epidermal pale colour in the late summer provides a benefit of increased camouflage.     

Understanding the drivers of expert opinion when classifying species as extinct

The criteria as laid out by the International Union for the Conservation of Nature (IUCN) Red List are the gold standard by which the extinction risk of a species is assessed and where appropriate biological extinctions are declared. However, unlike all other categories, the category of extinct lacks a quantitative framework for assigning this category. Given its subjective nature, we surveyed expert assessors working on a diversity of taxa to explore the attributes they used to declare a species extinct. Using a choice experiment approach, we surveyed 674 experts from the IUCN Species Survival Commission specialist groups and taskforces. Data availability, time from the last sighting, detectability, habitat availability, and population decline were all important attributes favored by assessors when inferring extinction. Respondents with red-listing experience assigned more importance to the attributes data availability, time from the last sighting, and detectability when considering a species extinction, whereas those respondents working with well-known taxa gave more importance to the time from the last sighting. Respondents with no red-listing experience and those working with more well-known taxa (i.e., mammals and birds) were overall less likely to consider species extinct. Our findings on the importance assessors place on attributes used to declare a species extinct provide a basis for informing the development of specific criteria for more accurately assessing species extinctions.     

隧道火灾的全尺寸试验研究

在3条公路隧道上进行了10次全尺寸试验,研究不通火灾条件和风速下烟气的运动情况。主要测量了各隧道1000m范围内的拱顶下方烟气温度、烟气层高度分布以及烟气前锋的运动情况等,并分析了纵向风速对火灾羽流形态、烟气前锋运动速度、隧道内线型缆式感温探测系统响应等的影响。此处所列的所有全尺寸试验数据可以进行进一步的分析,以便研究各种已知火灾模型在计算长隧道火灾时所得的结果是否有效。     

Design of Experimental Streams for Simulating Headwater Stream Restoration1

Huang, Jung-Chen, William J. Mitsch, and Andrew D. Ward, 2010. Design of Experimental Streams for Simulating Headwater Stream Restoration. Journal of the American Water Resources Association (JAWRA) 1-15. DOI: 10.1111/j.1752-1688.2010.00467.x Abstract: Headwater streams flowing through agricultural fields in the midwestern United States have been extensively modified to accommodate subsurface drainage systems, resulting in deepened, straightened, and widened streams. To restore these headwater streams, partial or total reconstruction of channels is frequently attempted. There are different approaches to reconstructing the channel, yet there is little evidence that indicates which promises more success and there has been no experimental work to evaluate these approaches. This study designs three experimental channels – two-stage, self-design, and straightened channels – on a human-created swale at the Olentangy River Wetland Research Park, Columbus, Ohio, for long-term evaluation of headwater stream evolution after restoration. The swale receives a continuous flow of pumped river water from upstream wetlands. Using streamflow and stage data for the past 12 years, a channel-forming discharge of 0.18 m³/s was estimated from bankfull discharge, effective discharge, and recurrence interval. These stream channels, after construction, will be monitored to evaluate physical, chemical, and biological responses to different channels over a decade-long experiment. We hypothesize that the three stream restoration designs will eventually evolve to a similar channel form but with different time periods for convergence. Monitoring the frequency and magnitude of changes over at least 10 years is needed to document the most stable restored channel form.     

微波催化氧化处理正丁酸废水Ni-Co-Ce-O催化剂的制备及表征

采用微波催化氧化处理正丁酸模拟废水,以COD去除率为评价指标,对固相-焙烧法制备的3个系列共45种催化剂进行筛选,通过正交实验对催化剂制备工艺进行优化,并对优选出的催化剂进行XRD和SEM表征。结果表明,NiO+Co₂O₃+CeO₂（Ni∶Co=1∶1、NiO+Co₂O₃/CeO₂=1∶4）为筛选出的最优催化剂;Ni-Co-Ce-O催化剂最优制备条件为Ni：Co摩尔比1∶2、（NiO+Co₂O₃）/CeO₂质量比5%、研磨时间40 min、焙烧温度450℃、焙烧时间3 h,此条件下制备的催化剂催化效能最高,COD去除率达67%。     

Effects of inorganic chlorine source on dioxin formation using fly ash from a fluidized bed incinerator

Chlorine source is indispensable for polychlorinated dibenzo-p-dioxin and furan (PCDD/F) formation during municipal solid waste (MSW) incineration. Inorganic chlorine compounds were employed in this study to investigate their effects on PCDD/F formation through heterogeneous synthesis on fly ash surfaces. A fly ash sample obtained from a fluidized bed incinerator was sieved to different size fractions which served as the PCDD/F formation sources. The capability of different metal chlorides which facilitate the formation of PCDDs/Fs was found to follow the trends: Na ＜ Mg ＜ K ＜ Al ＜ Ca, when two particle fractions of ＞177 μm and 104-125 μm were used in the experiments. However, the capability of NaCl, MgCl2 and KCl did not seem much different from each other, whereas CaCl2 and AlCl3 were much more active in PCDD/F formation. NaCl and MgCl2 were relatively effective to produce more PCDDs, while KCl, AlCl3 and CaCl2 generated more PCDFs during heterogeneous reactions occurring on fly ash. 2,3,7,8-TCDF was the most significant contributor to the toxicity of the PCDDs/Fs formed from inorganic chlorine sources. Decreasing the sizes of fly ash particles led to more active formation of PCDDs/Fs when NaCl was used as inorganic chlorine in the experiment. The highest PCDDs/Fs produced from particles with size ＜37 μm, while the lowest PCDDs/Fs produced from particles with size ＞177 μm. The toxicity generally increased with decreasing size of the fly ash particles. The formation of PCDDs was mainly facilitated by the two size fractions, 104-125 μm and ＜37 μm, while formation of PCDFs was favored by the two other size fractions, ＞177 μm and 53-104 μm.