Preparation of pure gum raw materials-low brown algae application

Octenylsuccinate starch ester, also called pure gum, is non-toxic and odourless modified starch which is widely used in many food fields. This study synthesized pure gum in a reaction kettle using the low molecular weight trehalose and octenyl succinic acid. An orthogonal test was carried out to find how the reaction factors affect the synthetization of octenylsuccinic acid polysaccharide ester and to optimize the reaction at single factor level. The optimal products were obtained using 1:2 of octenylsuccinic acid:alginic acid, catalysed by 0.1% p-toluenesulfonic acid catalyst for 1.5 h at 200℃ under vacuum conditions.The gained product contains up to 46% of seaweed gel monoesters. The degree of esterification of the polysaccharide is controlled by the use of the small-molecule trehalose. Compared with the traditional methods, our process can reduce raw material cost and improve emulsification stability of pure gum. These all can significantly improve the market competitiveness of pure gum products.     

用遗传算法对自动控制系统数学模型寻优

探讨用遗传算法对数学模型进行优化。考虑到控制系统稳健性的要求 ,用遗传算法寻找出控制系统最佳稳定域 ,实现控制系统数学模型的寻优。阐述了用遗传算法求解问题的步骤和参数的取值 ,并用仿真实验对优化结果进行了检验。结果表明 :在控制系统数学模型的优化中 ,遗传算法具有其他算法无可比拟的优越性。     

Study on methods of land use dynamic monitoring at county level

Remote sensing technique has played an important role in land use dynamic monitoring, but as for the land use dynamic monitoring at county level, traditional remote sensing methods such as satellite imagery visual interpretation and computer classification can not meet its demand for accuracy. The result of 1: 10 000 land use investigation map has high accuracy, but this method can not be used to dynamically monitor the land use because of its big expenses, long period and difficulty in updating data. In this paper, the characteristics of physiognomy, climate and the status of land use in Dehui County are taken into consideration and a set of method, which takes use of 3S techniques and applies to Northeast China Plain, is come up with. When the land use type of a land parcel changed as a whole, the date updating can be make by changing its land type ID in the attribute table in a GIS. When the land use type of an irregular area changed, GPS receivers are used to position its border. This set of method is characteristic of high accuracy and low expenses. It gets the information of land use change timely and can be used to dynamically monitor the land use. Foundation item: Under the auspices of the key project of the National Ninth Five-year Plan (96-B02-01-07). Biography: LI Lin-yi (1968 —), female, a native of Jilin, Ph. D. candidate of Changchun Institute of Geography, the Chinese Academy of Sciences. Her research interest includes land use change monitoring and crop yield estimation using “3S” techniques.     

中国汽车空调行业HFC-134a需求和排放预测

 近年来HFC-134a作为中国汽车空调行业CFC-12制冷剂最主要的替代品,其消费量增长迅速,是中国消费量最大的HFCs（氢氟烃类物质）。以2005年为基线,通过制冷剂替代、技术进步、熟练操作和政策控制等情景假设,预测了中国汽车空调行业HFC-134a的需求量及排放量。结果表明：到2010和2015年,汽车空调HFC-134a的消费量将分别接近2.0万和3.5万t,排放量将分别接近1.6万和3.0万t,约折合排放21.0 和39.0 Mt CO₂当量。上述排放相对基线情景（即维持当前政策措施和不开展回收活动）,2010年和2015年减排温室气体分别为6.7 和13.0 Mt CO₂当量。     

Ionospheric response to the geomagnetic storm on 13–17 April 2006 in the West Pacific region

This paper presents an investigation of geomagnetic storm effects in the equatorial and middle-low latitude F-region in the West Pacific sector during the intense geomagnetic storm on 13–17 April, 2006. The event, preceded by a minor storm, started at 2130 UT on April 13 while interplanetary magnetic field (IMF) B_z component was ready to turn southward. From 14–17 the ionosphere was characterized by a large scale enhancement in critical frequency, foF2 (4～6 MHz) and total electron content (TEC) (～30TECU, 1TECU=1×10¹⁶el/m²) followed by a long-duration negative phase observed through the simultaneous ionospheric sounding measurements from 14 stations and GPS network along the meridian 120°E. A periodic wave structure, known as traveling ionospheric disturbances (TIDs) was observed in the morning sector during the initial phase of the storm which should be associated with the impulsive magnetospheric energy injection to the auroral. In the afternoon and nighttime, the positive phase should be caused by the combination of equatorward winds and disturbed electric fields verified through the equatorial F-layer peak height variation and modeled upward drift of Fejer and Scherliess [1997. Empirical models of storm time equatorial electric fields. Journal of Geophysical Research 102, 24,047–24,056]. It is shown that the large positive storm effect was more pronounced in the Southern Hemisphere during the morning-noon sector on April 15 and negative phase reached to lower magnetic latitudes in the Northern Hemisphere which may be related to the asymmetry of the thermospheric condition during the storm.     

Cd(II), Pb(II) and Zn(II) Removal from Contaminated Water by Biosorption Using Activated Sludge Biomass

Biosorption using activated sludge biomass (ASB) as a potentially sustainable technology for the treatment of wastewater containing different metal ions (Cd(II), Pb(II) and Zn(II)) was investigated. ASB metal uptake clearly competed with protons consumed by microbial biomass compared with control tests with non‐activated sludge biomass. Biosorption tests confirmed maximum exchange between metal ions and protons at pH 2.0–4.5. It was revealed by the study that the amount of metal ions released from the biomass increased with biomass sludge concentration. The result showed that maximum absorption of metal ions was observed for Cd(II) at pH 3.5, Pb(II) at pH 4.0, and pH 4.5 for Zn(II) ions. The maximum absorption capacities of ASB for Cd(II), Pb(II) and Zn(II) were determined to be 59.3, 68.5 and 86.5%, respectively. The biosorption of heavy metals was directly proportional to ASB stabilization corresponding to a reduction in heavy metals in the order of Cd < Pb < Zn. The order of increase of biosorption of metal ions in ASB was Zn(II) < Pb(II) < Cd(II), and this was opposite to that of non active sludge. The results indicate that ASB is a sustainable tools for the bioremediation of Cd(II), Pb(II) and Zn(II) ions from industrial sludge and wastewater treatment plants.     

Leveraging similarity analysis to understand variability in movement behavior

The increasingly large volume of trajectories of moving entities obtained through GPS and cellphone tracking, telemetry, and other location-aware technologies motivates researchers to understand the implicit patterns hidden in movement trajectories and understand how movement is influenced by the environmental context. Trajectory similarity serves as an important tool in computational movement analysis and as the foundation of revealing those patterns. However, there are various trajectory similarity measures, each of which has its own strengths and weaknesses. In this article, we present a hierarchical clustering framework that integrates five commonly used similarity measures, including Fréchet distance, dynamic time warping, Hausdorff distance, longest common subsequence, and normalized weighted edit distance, a special kind of edit distance for movement analysis. The framework aims at clustering similar patterns and identifying variability in movement. The optimal number of clusters are first obtained. Then, the clusters are characterized by environmental variables to explore the associations between variability in movement and the environmental conditions. We evaluate the proposed framework using 15 years of tracking data of turkey vultures, tracked at 1- to 3-h sampling intervals, during their fall and spring migration seasons. The results suggest that, at 5% significance level, turkey vultures select their movement paths intentionally and those selections appear to be related to certain environmental context variables, including thermal uplift, vegetation state (observed indirectly through Normalized Difference Vegetation Index), temperature, precipitation, tailwind, and crosswind. And interestingly, there exist preferential differences among individuals. Although the preference of the same turkey vulture is not strictly consistent over different years, each individual tends to preserve a more similar preference over different years, compared with the preferences of other turkey vultures.     

Classifying Human Activity Patterns from Smartphone Collected GPS data: A Fuzzy Classification and Aggregation Approach

Smartphones have emerged as a promising type of equipment for monitoring human activities in environmental health studies. However, degraded location accuracy and inconsistency of smartphone‐measured GPS data have limited its effectiveness for classifying human activity patterns. This study proposes a fuzzy classification scheme for differentiating human activity patterns from smartphone‐collected GPS data. Specifically, a fuzzy logic reasoning was adopted to overcome the influence of location uncertainty by estimating the probability of different activity types for single GPS points. Based on that approach, a segment aggregation method was developed to infer activity patterns, while adjusting for uncertainties of point attributes. Validations of the proposed methods were carried out based on a convenient sample of three subjects with different types of smartphones. The results indicate desirable accuracy (e.g. up to 96% in activity identification) using of this method. Two examples are provided in the Appendix to illustrate how the proposed methods could be applied in environmental health studies. Researchers could tailor this scheme to fit a variety of research topics.     

Combined particle swarm optimization and linear discriminant analysis for landslide image classification: application to a case study in Taiwan

In Taiwan many reservoirs are constructed in mountain areas. Unfortunately, several earthquakes shook the soil, and typhoons brought a huge amount of water to the reservoir zone. In the past studies, remote-sensing image data were used to effectively monitor the landslide near reservoirs. In recent years, linear discriminant analysis (LDA) has become a well-known method for image classification. However, there are few studies to optimize the linear classification function. While the ancillary information has been adopted easily by new methodologies, the ancillary information must be examined by a landslide image classification system. To explore the effects of optimization on the LDA equations, three approaches were compared: (a) conventional LDA; (b) combined discrete rough sets and LDA (DRS + LDA), which identify the core factors and the corresponding thresholds of landslide occurrence; and (c) combined particle swam optimization algorithm and LDA (PSO + LDA), which optimizes the parameters of LDA equation to attain the best classification outcomes. The above methods were applied to a reservoir region in Taiwan, and the following classification results were obtained. The application of DRS + LDA in our case study reduced the number of ancillary attributes from 14 to 5, and resulted in an accuracy rate of 0.83. On the other hand, the application of PSO + LDA resulted in the same accuracy rate as that of DRS + LDA, whereas the accuracy rate of conventional LDA was found to be 0.78.     

Petroleum system analysis of the Khatatba Formation in the Shoushan Basin,north Western Desert,Egypt

The Middle Jurassic Khatatba Formation is an attractive petroleum exploration target in the Shoushan Basin, north Western Desert, Egypt. However, the Khatatba petroleum system with its essential elements and processes has not been assigned yet. This study throws the lights on the complete Khatatba petroleum system in the Shoushan Basin which has been evaluated and collectively named the Khatatba-Khatatba (!) petroleum system. To evaluate the remaining hydrocarbon potential of the Khatatba system, its essential elements were studied, in order to determine the timing of hydrocarbon generation, migration and accumulation. Systematic analysis of the petroleum system of the Khatatba Formation has identified that coaly shales and organic-rich shales are the most important source rocks. These sediments are characterised by high total organic matter content and have good to excellent hydrocarbon generative potential. Kerogen is predominantly types II–III with type III kerogen. The Khatatba source rocks are mature and, at the present time, are within the peak of the oil window with vitrinite reflectance values in the range of 0.81 to 1.08 % Ro. The remaining hydrocarbon potential is anticipated to exist mainly in stratigraphic traps in the Khatatba sandstones which are characterised by fine to coarse grain size, moderate to well sorted. It has good quality reservoir with relatively high porosity and permeability values ranging from 1 to 17 % and 0.05–1,000 mD, respectively. Modelling results indicated that hydrocarbon generation from the Khatatba source rocks began in the Late Cretaceous time and peak of hydrocarbon generation occurred during the end Tertiary time (Neogene). Hydrocarbon primarily migrated from the source rock via fractured pathways created by abnormally high pore pressures resulting from hydrocarbon generation. Hydrocarbon secondarily migrated from active Khatatba source rocks to traps side via vertical migration pathways through faults resulting from Tertiary tectonics during period from end Oligocene to Middle Miocene times.