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91.
Absorption is one of the most widely used techniques for treating odourous waste gases. An improvement of the effectiveness of gas scrubbers can be achieved by using adapted washing liquids. A screening test is proposed as a low cost tool for testing washing liquids on industrial waste gases. The odour index is used to identify the main cause of the specific smell and to simplify the analysis of absorptive performances of washing liquids. The method is verified by experiments at a chocolate factory and a fat and oil refinery.  相似文献   
92.
Dormant propagule banks are important reservoirs of biological and genetic diversity of local communities and populations and provide buffering mechanisms against extinction. Although dormant stages of various plant and animal species are known to remain viable for decades and even centuries, little is known about the effective influence of recolonization from such old sources on the genetic continuity of intermittent populations under natural conditions. Using recent and old dormant eggs recovered from a dated lake sediment core in Kenya, we traced the genetic composition of a local population of the planktonic crustacean Daphnia barbata through a sequence of extinction and recolonization events. This was combined with a phylogeographic and population-genetic survey of regional populations. Four successive populations, fully separated in time, inhabited Lake Naivasha from ca. 1330 to 1570 AD, from ca. 1610 to 1720 AD, from ca. 1840 to 1940 AD, and from 1995 to the present (2001 AD). Our results strongly indicate genetic continuity between the 1840-1940 and 1995-2001 populations, which are separated in time by at least 50 years, and close genetic relatedness of them both to the 1330-1580 population. A software tool (Colonize) was developed to find the most likely source population of the refounded 1995-2001 population and to test the number of colonists involved in the recolonization event. The results confirmed that the 1995-2001 population most probably developed out of a limited number of surviving local dormant eggs from the previous population, rather than out of individuals from regional (central and southern Kenya) or more distant (Ethiopia, Zimbabwe) populations that may have immigrated to Lake Naivasha through passive dispersal. These results emphasize the importance of prolonged dormancy for the natural long-term dynamics of crustacean zooplankton in fluctuating environments and suggest an important role of old local dormant egg banks in aquatic habitat restoration.  相似文献   
93.
CORINAIR atmospheric emission inventories are frequently used input data for air quality models with a domain situated in Europe. In CORINAIR emission inventories, sources are broken down over 11 major source categories. This paper presents spatial surrogates for the disaggregation of CORINAIR atmospheric emission inventories for input of air pollutants and particulate matter to grid or polygon based air quality model domains inside Europe. The basis for the disaggregation model was the CLC2000 land cover data to which statistical weights were added. Weights were population census data for residential emissions, employment statistics for agricultural and industrial area emissions, livestock statistics for ammonia emissions and annual aircraft movements for emissions realized by air transport. Additional road and off-road network information was used to disaggregate emissions realized by traffic. A comparison of top down produced emission estimates with spatially resolved national emission data for The Netherlands and the United Kingdom gave confidence in the present spatial surrogates as a tool for the top down production of atmospheric emission maps. Explained variance at a spatial resolution of 5 km was >70% for CO, NMVOC and NOx, >60% for PM10 and almost 50% for SO2.  相似文献   
94.
Phosphorus loss from bank erosion was studied in the catchment of River Odense, a lowland Danish river basin, with the aim of testing the hypothesis of whether stream banks act as major diffuse phosphorus (P) sources at catchment scale. Furthermore, the study aimed at analyzing the impact of different factors influencing bank erosion and P loss such as stream order, anthropogenic disturbances, width of uncultivated buffer strips, and the vegetation of buffer strips. A random stratified procedure in geographical information system (GIS) was used to select two replicate stream reaches covering different stream orders, channelized vs. naturally meandering channels, width of uncultivated buffer strips (≤ 2 m and ≥ 10 m), and buffer strips with different vegetation types. Thirty-six 100-m stream reaches with 180 bank plots and a total of 3000 erosion pins were established in autumn 2006, and readings were conducted during a 3-yr period (2006-2009). The results show that neither stream size nor stream disturbance measured as channelization of channel or the width of uncultivated buffer strip had any significant ( < 0.05) influence on bank erosion and P losses during each of the 3 yr studied. In buffer strips with natural trees bank erosion was significantly ( < 0.05) lower than in buffer strips dominated by grass and herbs. Gross and net P input from bank erosion amounted to 13.8 to 16.5 and 2.4 to 6.3 t P, respectively, in the River Odense catchment during the three study years. The net P input from bank erosion equaled 17 to 29% of the annual total P export and 21 to 62% of the annual export of P from diffuse sources from the River Odense catchment. Most of the exported total P was found to be bioavailable (71.7%) based on a P speciation of monthly suspended sediment samples collected at the outlet of the river basin. The results found in this study have a great importance for managers working with P mitigation and modeling at catchment scale.  相似文献   
95.
Separate effects of ammonium (NH4+) and nitrate (NO3-) on boreal forest understorey vegetation were investigated in an experiment where 12.5 and 50.0 kg nitrogen (N) ha(-1) year(-1) was added to 2 m2 sized plots during 4 years. The dwarf-shrubs dominating the plant community, Vaccinium myrtillus and V. vitis-idaea, took up little of the added N independent of the chemical form, and their growth did not respond to the N treatments. The grass Deschampsia flexuosa increased from the N additions and most so in response to NO3-. Bryophytes took up predominately NH4+ and there was a negative correlation between moss N concentration and abundance. Plant pathogenic fungi increased from the N additions, but showed no differences in response to the two N forms. Because the relative contribution of NH4+ and NO3- to the total N deposition on a regional scale can vary substantially, the N load a habitat can sustain without substantial changes in the biota should be set considering specific vegetation responses to the predominant N form in deposition.  相似文献   
96.
Herbicides of the chlorinated phenoxyalkanoic acid group like 2,4-D, 2,4-DP and MCPP, belong to the most commonly used pesticides. This is also true for the Land Brandenburg. Therefore, this substance group was integrated in the current state monitoring programme for ground and surface water quality. Starting in 2001, the analysis was carried out complying with DIN 38407-20 by gas chromatography and mass spectrometric detection after enrichment with solid phase extraction and following derivatization with diazomethane-forming methyl esters. Quantifying 2,4-D considering selected ions in a surface water sample from the river Oder, a remarkable peak pattern was observed. A second peak with identical spectrum was found about 0.7 minutes earlier than the 2,4-D calibrated peak. Its intensity suggested a concentration 10–20 fold higher than the 2,4-D level. This unknown peak was identified as 2,6-D which is a structure isomer of the herbicide 2,4-D. This substance has not been described in literature or chemical substance databases known to us yet. Structure isomers have been found in other samples too. We suppose that the chlorinated phenoxyalkanoic acids chlorinated in the 6-position of the phenyl ring are formed as a technical by-product and show a higher persistance than the commonly known agents.  相似文献   
97.
This paper aimed at to explore the consequences of cyclone victims due to unavailability of infrastructural supports and to prop up the recognition that the infrastructure has a vital role to play in societies’ resilience during catastrophic situation. The paper begins with a review of the science regarding climate change impact and cyclone disaster in Bangladesh. It emphasizes the consequences of cyclone Aila in a selected coastal community in the remote coastal area. A field survey was conducted by authors during March-August 2009. Eight available infrastructures were selected for this analysis. Uniformity of distribution (R), demand index (Di) and degree of demand (DD) of the selected infrastructures were calculated by using nearest neighbourhood methods of analysis. Results show that based on its specific planning standards none of the selected infrastructure can support 50% of the total population. Accordingly, it was observed that 76% respondent could not reach in safer place due to rush of water intrusion and also because of the inundation of road-network. The nearness to the available cyclone shelter, and place of taking shelter during cyclone is positively correlated (r = 0.38; p < 0.001). However, the poor people had less opportunity to take shelter in cyclone shelters, although none of the respondents groups whose monthly income is above 75 USD stands without any infrastructural support. Such important observation may hint the influence of local elites on the local disaster mitigation planning practice in Bangladesh. Almost 90% of the respondents claimed that they had no access to enter the available cyclone shelter. Furthermore, the damaged infrastructures added more hindrances during post disaster activities and also increased the sufferings of the victims. If there were adequate cyclone shelters or rehabilitation centre, the affected people could take shelter and continue other works temporarily. Results drawn from this research will be useful for local and national level planners, as well as international donors for future disaster mitigation planning in the studied area and the methodology can be applied in similar countries and geographical territories.  相似文献   
98.
在557块针叶林分中进行调查,以图了解欧洲越桔(Vacciniummyrtillus)、越桔(V.vitis-idaea)和曲芒发草(Deschampsiaflexuosa)与氮沉积率的相互联系.欧洲越桔在高氮地区比在低氮地区发生频度、丰富度都较少并且易感染叶部病原(Valdensiaheterodoxa),越桔的发生与氮沉积的增加呈明显的负相关,曲芒发草却没有这种趋势.在高氮沉积地区,欧洲越桔在优势种为欧洲赤松的林分中比在挪威云杉为优势种的林分中更为最普遍.在氮沉积较低水平的地区不是这种情形.调查的情况与增施氮素实验的结果一致,氮沉积对植被显示了巨大的效应.数据表明即使是较低的氮沉积也可能减少针叶林分林下植被最优势种的丰富度.  相似文献   
99.
51 Greek, Roman and Renaissance marble busts from the Antiquarium of the Residenz in Munich were studied for their C- and O-isotopic composition. Apart from some overlapping values, this technique permits — contrary to microscopic and chemical methods — localization of different Turkish, Greek and Italian marble deposits.  相似文献   
100.
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