MINLP‐Optimierung des Hybridverfahrens Destillation/Schmelzkristallisation

The hybrid separation process distillation/melt crystallization offers a cost wise attractive alternative compared to conventional distillation processes. In this work, the systematic and cost optimal design of this combination process is considered. The focus is on the optimal choice of operating and structural degrees of freedom.     

VAMOS:在历经20年的成功GSM运行之后获得重要语音改进

1 引言 在20世纪80年代末期,GSM技术最初是为有效支持语音服务而设计的.1992年出现了第一批网络,与此同时,全球将近200个国家及地区的530多个商业网络投入了运行,也就是说,GSM已成为全球普遍采用的技术.经过20多年的运营,已出现了很多进展,例如,通过GPRS和EDGE来增强GSM以支持像电子邮件和网络浏...     

Wind turbine condition monitoring based on SCADA data using normal behavior models. Part 1: System description

This paper proposes a system for wind turbine condition monitoring using Adaptive Neuro-Fuzzy Interference Systems (ANFIS). For this purpose: (1) ANFIS normal behavior models for common Supervisory Control And Data Acquisition (SCADA) data are developed in order to detect abnormal behavior of the captured signals and indicate component malfunctions or faults using the prediction error. 33 different standard SCADA signals are used and described, for which 45 normal behavior models are developed. The performance of these models is evaluated in terms of the prediction error standard deviations to show the applicability of ANFIS models for monitoring wind turbine SCADA signals. The computational time needed for model training is compared to Neural Network (NN) models showing the strength of ANFIS in training speed. (2) For automation of fault diagnosis Fuzzy Interference Systems (FIS) are used to analyze the prediction errors for fault patterns. The outputs are both the condition of the component and a possible root cause for the anomaly. The output is generated by the aid of rules that capture the existing expert knowledge linking observed prediction error patterns to specific faults. The work is based on continuously measured wind turbine SCADA data from 18 turbines of the 2 MW class covering a period of 30 months.The system proposed in this paper shows a novelty approach with regard to the usage of ANFIS models in this context and the application of the proposed procedure to a wide range of SCADA signals. The applicability of the set up ANFIS models for anomaly detection is proved by the achieved performance of the models. In combination with the FIS the prediction errors can provide information about the condition of the monitored components.In this paper the condition monitoring system is described. Part two will entirely focus on application examples and further efficiency evaluation of the system.     

Agile Project Management: A Case Study of a Virtual Research Environment Development Project

In this paper we use a case study of a project to create a Web 2.0-based, Virtual Research Environment (VRE) for researchers to share digital resources in order to reflect on the principles and practices for embedding eResearch applications within user communities. In particular, we focus on the software development methodologies and project management techniques adopted by the project team in order to ensure that the project remained responsive to changing user requirements without compromising their capacity to keep the project ‘on track’, i.e. meeting the goals declared in the project proposal within budget and on time. Drawing on ethnographic fieldwork, we describe how the project team, whose members are distributed across multiple sites (and often mobile), exploit a repertoire of coordination mechanisms, communication modes and tools, artefacts and structuring devices as they seek to establish the orderly running of the project while following an agile, user-centred development approach.     

Infestation of dried cassava (Manihot esculenta Crantz) by Prostephanus truncatus (Horn( (Coleoptera: Bostrichidae)

Stored dried cassava is known to become heavily infested by Prostephanus truncatus (Horn). A field study was undertaken in Tanzania to determine the extent of losses that this pest could cause in fermented and unfermented dried cassava roots stored over a period of about 4 months. In fermented roots, the mean weight loss (±SD) rose to 73.6 ± 25.9% over this period compared with 52.3 ± 12.0% in unfermented roots. At each time interval that roots were examined, the weight loss in fermented roots was significantly higher. Subsequent laboratory studies, undertaken to identify some of the factors responsible for this difference between the two types of cassava comprised (1) a determination of the length of larval and pupal development at 27°C and 50 or 70% r.h., (2) adult preference for the two types, and (3) their susceptibility to adult boring. P. truncatus developed at a similar rate in both fermented and unfermented roots, but the adults appeared to prefer the fermented cassava possibly because it was easier to bore into. This was certainly one factor making fermented roots more susceptible to damage by adults. It is concluded that although P. truncatus caused lower weight loss in the unfermented compared with the fermented roots, both were so heavily damaged that it is not worth recommending the storage of one rather than the other. The role of cassava as an intermediate host for P. truncatus is discussed and consideration is given to the need to control the beetle in cassava in order to reduce cross-infestation to maize.     

Infestation of maize cobs by Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)—Aspects of biology and control

The initial attack and subsequent development of Prostephanus truncatus on maize cobs, with husk intact, was investigated at 27°C and 40, 50 and 70% r.h. The beetles showed a strong tendency to attempt infestation by first boring into the maize cob cores although they eventually gained access to the grain via the apex of the cob by walking between the grain and husk. At 50 and 70% r.h., the rate of oviposition over the first 2 wk was particularly high, while at 40% r.h. the rate was more or less constant. Some F₁ generation completed their development within 32–39 days at 50 and 70% r.h. and within 39–46 days at 40% r.h. Under all three moisture conditions, adult dispersal from the cobs was first detected at the end of the sixth week.

Estimates were made of the rate of increase of P. truncatus under each of the three moisture conditions. The population increased most rapidly at 70% r.h. and was at its peak between the eighth and twelfth weeks during which time grain damage and weight loss had effectively reached 100%. At 50% r.h., this stage was reached between the twelfth and sixteenth weeks while by this time at 40% r.h. the grain weight loss was only 40%.

Two novel techniques were tested for protecting maize cobs from infestation by P. truncatus. The exposed ends of maize cob cores were dipped into permethrin, 0.1% w/v aqueous dispersion or 0.5% w/w dilute dust, or untreated cobs were kept with permethrin-treated expanded-polystyrene blocks which acted as alternative refuges. Such treatments were examined at two beetle population densities. Dipping of the maize core was particularly effective in the prevention of infestation at low population density. This technique should be the subject of a field trial and if successful will offer important advantages over currently recommended control procedures.     

High frequency current catheter ablation of accessory conduction pathways

Postoperative nausea and vomiting (PONV) are relatively common troublesome distressing symptoms. The incidence is reported to be as high as 20-51%. Ninety adult ASA I and II patients scheduled for laparoscopic gynecological or surgical interventions, were randomly and equally assigned to one of the three groups in the immediate postoperative period: Group 1 received 0.1 ml.kg(-1) normal saline intravenously, while Group 2 received 0.5 mg.kg(-1) ephedrine intramuscularly and Group 3 received 0.25 mg.kg(-1) propofol intravenously as preventive antiemetic therapy. Sixty-six, 33 and 50 percent of patients experienced nausea and vomiting syndrome in Group 1, 2 and 3 respectively. Both ephedrine and propofol proved to have antiemetic properties. Ephedrine treated group of patient had significant less emetic score than propofol. No significant hemodynamic changes were recorded in both groups.     

Intracranial microembolic signals during radiofrequency ablation of accessory pathways

Intracranial microembolic signals, probably caused by gaseous emboli, are readily detectable in patients undergoing radiofrequency ablation in the left side of the heart only. Clinical value of the detected signals could not be equivocably assessed, because only 2 of the patients who were examined (both emboli positive) had transient neurologic symptoms.     

Insect traps tested as an aid to pest management in milled rice stores

Various insect traps were tested in a milled rice store, in Indonesia, with a view to developing an insect trapping method that would enable estimates of insect populations to be obtained reliably and easily. These estimates might then be used to predict the optimum timing for pest control measures. The trial was conducted over a 7 month period in a store containing 4 bag stacks of polished rice. Trap catches were compared with population estimates obtained by sifting the contents of bags selected from all regions of the stacks and by very extensive, monthly spear sampling of outer bags. The insects observed to occur most frequently in the store were Sitophilus zeamais, Ahasverus advena, Tribolium castaneum, Oryzaephilus surinamensis, Typhaea stercorea, Carpophilus pilosellus and Xylocoris flavipes. The precision of the spear sampling method for these species was estimated; large numbers of samples (200+) were usually required to obtain population estimates with a reasonably high degree of precision. The insect traps indicated population changes that were roughly in proportion to those indicated by spear sampling. The most useful of the traps tested was a bait bag containing brown rice milled from local rough rice. For monitoring insects in milled rice stores this trap would have several advantages over extensive spear sampling—it is positioned and retrieved more easily, the extraction of insects from it is very simple and, unlike spear sampling, it does not damage sacks. Further research is required to test traps in operational stores, particularly to establish the relationship between trap catches and the actual insect population so that trap catch thresholds may be set. Control techniques could then be applied when trap thresholds are exceeded, avoiding unnecessary treatments and optimising control.