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91.
Pretreating pine chips (Pinus sylvestris) with sodium hydroxide prior to the alkaline delignification (kraft, kraft-anthraquinone, and soda-anthraquinone) can facilitate the recovery of the carbohydrate degradation products from alkaline pulping liquors. Under suitable pretreatment conditions large amounts of carbohydrate degradation products (aliphatic acids) were formed relative to lignin. The lignin fraction was composed of comparatively low-molecular-weight fragments. Although the delignification was considerably retarded and the yield (based on wood) was decreased by 1–3%, the properties of the resulting pulp were essentially maintained despite pretreatment. Finally, data are given for the composition of aliphatic acids in liquors resulting from pretreatments. 相似文献
92.
Tommi Ekholm Sampo Soimakallio Sara Moltmann Niklas Höhne Sanna Syri Ilkka Savolainen 《Energy Policy》2010
The post-2012 climate policy framework needs a global commitment to deep greenhouse gas emission cuts. This paper analyzes reaching ambitious emission targets up to 2050, either ‐10% or ‐50% from 1990 levels, and how the economic burden from mitigation efforts could be equitably shared between countries. The scenarios indicate a large low-cost mitigation potential in electricity and industry, while reaching low emission levels in international transportation and agricultural emissions might prove difficult. The two effort sharing approaches, Triptych and Multistage, were compared in terms of equitability and coherence. Both approaches produced an equitable cost distribution between countries, with least developed countries having negative or low costs and more developed countries having higher costs. There is, however, no definitive solution on how the costs should be balanced equitably between countries. Triptych seems to be yet more coherent than other approaches, as it can better accommodate national circumstances. Last, challenges and possible hindrances to effective mitigation and equitable effort sharing are presented. The findings underline the significance of assumptions behind effort sharing on mitigation potentials and current emissions, the challenge of sharing the effort with uncertain future allowance prices and how inefficient markets might undermine the efficiency of a cap-and-trade system. 相似文献
93.
Alanko Timo O. Erkio Hannu H. A. Haikala Ilkka J. 《IEEE transactions on pattern analysis and machine intelligence》1984,(4):422-431
Experimnental results are given about the performance of six sorting algorithms in a virtual memory based on the working set principle. With one exception, the algorithms are general internal sorting algorithms and not especially tuned for virtual memory. Algorithms are compared in terms of their time requirements, space requirements, and space-time integrals. The relative performances of the algorithms vary from one measure to the other. Especially in terms of a space-time integral, quicksort turns out to be the best algorithm, also in a working set virtual memory environment. 相似文献
94.
Catalytic thermometric titration is used for the determination of the phenol and resorcinol components of resins formed by the sodium hydroxide- and ammonia-catalysed condensations of phenol, resorcinol and mixtures of phenol and resorcinol, with formaldehyde. 相似文献
95.
The present investigation describes some mental causal models used in incident reports. Some of the models (e.g., single-cause models) are simpler than others (e.g., causal-tree models). The models are also associated with different ways of explaining an incident or accident and with different recommendations for increasing the safety of a system. In study 1, incident reports from Swedish nuclear power plants known to use human or organisational factors were analysed. The analysis showed that the most frequent model was a simple single-cause model. Two-step models and more complex models were less frequent. Study 2 analysed all licensee event reports (including those reports not related to human organisational factors) from four reactors assessed by regulators during the year. The results showed that single-cause and two-step accident models were more frequent than more complex models. The analyses also revealed that different detection modes were related to different models. 相似文献
96.
Ilkka Autio Author Vitae 《Pattern recognition》2006,39(7):1290-1299
We address the problem of computationally efficient visual classification of objects, and propose a system for solving multi-class problems in domains that have inherent hierarchic structure, such as subclass-superclass-relationships based on visual similarity. Class relationships are used at runtime to select the computationally simplest feature space that allows classification at high level of confidence for each example view. Classification accuracies can then be further improved using rank-order voting over multiple views. Our experimental results show that our system compares favorably to previously published results using a demanding benchmark. The results support the hypothesis that class hierarchies based on visual similarities are feasible and useful in controlling the accuracy vs. speed tradeoffs in classification. 相似文献
97.
Lehtola MJ Miettinen IT Lampola T Hirvonen A Vartiainen T Martikainen PJ 《Water research》2005,39(10):1962-1971
We studied how pipe material can modify the effectiveness of UV- and chlorine disinfection in drinking water and biofilms. This study was done with two pipe materials: copper and composite plastic (polyethylene, PE) in a pilot scale water distribution network. UV-disinfection decreased viable bacterial numbers in the pilot waterworks and outlet water of pipes on average by 79%, but in biofilms its disinfecting effect was minor. Chlorine decreased effectively the microbial numbers in water and biofilms of PE pipes. In outlet water from copper pipes, the effect of chlorination was weaker; microbial numbers increased back to the level before chlorination within a few days. In the biofilms present in the copper pipes, chlorine decreased microbial numbers only in front of the pipeline. One reason for weaker efficiency of chlorine in copper pipes was that its concentration declined more rapidly in the copper pipes than in the PE pipes. These results means that copper pipes may require a higher chlorine dosage than plastic pipes to achieve effective disinfection of the pipes. 相似文献
98.
Ice on wind turbine blades reduces efficiency and causes financial loss to energy companies. Thus, it is important to know the possible risk of icing already in the planning phase of a wind park. This paper presents a new Finnish Icing Atlas and the methodology behind it and is prepared by applying the mesoscale numerical weather prediction model AROME with 2.5km horizontal resolution and an ice growth model based on ISO 12494. The same meteorological dataset is used as was used in the Finnish Wind Atlas (published in 2009), and thus is fully compatible with and comparable with existing climatological wind resource estimations. Representation of the selected time period is evaluated from an icing point of view. Comparing reanalysed temperature and humidity datasets for both the past 20 years and the wind atlas period, we conclude that the used time period represents large‐scale atmospheric conditions favourable for icing. We perform a series of sensitivity tests to evaluate how sensitive this ice model is to input from the weather model. The new atlas presents climatological distributions of active and passive icing periods and wind power production loss in map form for three different heights (50, 100 and 200m) over all of Finland. The results show that the risk for active icing is much greater in coastal areas, while the risk of passive icing is larger inland. © 2016 The Authors. Wind Energy Published by John Wiley & Sons Ltd. 相似文献
99.
Endotoxins associated with cyanobacteria and their removal during drinking water treatment 总被引:7,自引:0,他引:7
The aim of this study was to investigate endotoxin concentrations in cyanobacterial water blooms and strains, and to assess the removal of endotoxins during drinking water treatment. Endotoxin concentrations were measured from 151 hepatotoxic, neurotoxic and non-toxic cyanobacterial water blooms by using Limulus amebocyte lysate (LAL) assay, and the results were compared to bacterial data. Endotoxin activities ranged from 20 to 3.8 x 10(4) endotoxin units (EU) per ml. Endotoxicity of the samples correlated with phycobiliprotein concentration that was used to assess cyanobacterial abundance, heterotrophic plate count, and Aeromonas spp. but it did not correlate with the number of coliforms or streptococci. The high endotoxin concentrations occasionally detected in the water bloom samples were probably due to Gram negative bacteria that existed together with cyanobacteria since the 26 axenic cyanobacterial strains from different genera that were studied showed very low endotoxin activity. No differences in endotoxin activity were detected between hepatotoxic, neurotoxic and non-toxic strains. Removal of endotoxins during drinking water treatment was studied at nine waterworks that previously had been associated with high numbers of cyanobacteria and that used different processes for water purification. Endotoxin concentration in raw waters ranged from 18 to 356 EU ml(-1). The treatment processes reduced 59-97% of the endotoxin activity; in the treated water the concentration ranged from 3 to 15 EU ml(-1). The most significant reduction occurred at the early stages of water treatment, during coagulation, settling and sand filtration. Activated carbon filtration either increased or had no effect on endotoxin concentration. Ozonation and chlorination had little effect on the endotoxin concentrations. 相似文献
100.
Three carrier materials (porous glass beads, DEAE‐cellulose, diatomaceous earth) for immobilized primary fermentation of beer were tested on a 1.6 litre scale. The influence of the carrier materials on flavour compounds in the green beer was analysed. The nature of the carrier affected the concentrations of some flavour compounds in a yeast strain specific manner. The findings suggest that the most appropriate material for immobilized primary fermentation of beer depends on the yeast strain used and the beer characteristics desired. 相似文献