Search

In this study, the aerodynamics of wings using an active high-lift system are investigated. The target is the flight mechanical description of the spanwise forces and resulting moments and the influence of the active high-lift system to their distribution. The high-lift system is a blown flap system divided into six segments per wing. Each segment is assumed to be individually controlled, so the system shall be used for aircraft control and system failure management. This work presents a flight mechanical sub-model for the simulation of flight dynamics, which has been derived from high-fidelity CFD results. An assessment of single-segment blowing system failures will be presented including recommendations for compensation of either lift or rolling moment loss. For this investigation, the compensation is required to act at the same wing side on which the failure appears. Thus, the potential for an increase of system reliability shall be proven. The results show that less performance investment in terms of pressurized air is necessary to compensate the rolling moment of a failing segment instead of its lift. However, large blowing performance increases for the remaining wing segments that occur for some of the failure cases.

Critical attention is being given to the application of expert systems to civil and construction engineering problems. A central feature of expert systems is the ability to explain the reasoning that these systems are using. This paper provides a succinct survey of some of the explanation features commonly found in expert systems. The paper presents the logic and computer code for a C language explanation facility which was developed for use with the M.1 expert system shell. The C program is context‐sensitive and allows explanations to be nested so the user can request progressively more detailed explanations. In addition to the explanation feature, the C program will allow access to ASCII files contain a variety of information. The C program has been used in some applications to access “help,” “conclusions,” “warning,” or “assumption” files. The paper provides a demonstration of the explanation program in a simple civil engineering context.

A twin bubble column was used to measure the kLa values for oxygen in model and cultivation media using the steady state method described previously (Adler et al. 1980). Desmophen and soy oil were used as antifoam agents together with model and/or cultivation media for Chaetomium cellulotyticum, Trichoderma reesei, Hansenula polymorpha, Saccharomyces cerevisiae and Escherichia coli. The bubble coalescence behavior is mainly influenced by antifoam agents and somewhat by protein and alcohol additives. In the range investigated (0.01 to 0.1%.), the kLa values are not influenced by the Desmophen concentration and only slighthly by the soy oil concentration (0.5 to 1.5%.). The coalescence behaviour was characterized by the ratio mcorr=(kLa)corr/(kLa)ref. A nutrient salt solution with Desmophen was used as a reference. The kLa measured in the investigated media were corrected by considering the differences in kLa's in the investigated and reference media. These mcorr values can directly be used for bubble columns close to the optimum aeration rate.

Summary The diagnosis of Spondylodiscitis after lumbar disc surgery has been based so far on clinical abnormalities, non-specific changes in chemical laboratory parameters [erythrocyte sedimentation rate (ESR), C-reactive protein (CRP)] and radiological examinations such as MRI. Such techniques do not enable any clear diagnosis to be made before the 3rd postoperative week.

Penicillium chrysogenum was cultivated in a suspension of pellets of a suitable size (less than 0.4 nun in diameter) in a 98-l-airlift reactor with an outer loop and a working volume of 90 I to produce Penicillin V during fed-batch fermentations.

Rabbit splenic capsular strips contract in response to angiotensin II and simultaneously release prostaglandins E and F into the bath fluid. Contractions, though not sustained, and prostaglandin release are dependent on the concentrations of angiotensin II.

A new method for quantitative evaluation of the microbial load of cork and cork stoppers, coded CORA (Cork Activity Assay) is described. It is based on measurement by gas chromatography of dimethylsulfide (DMS) evolving from the reduction of dimethylsulfoxide (DMSO) by microbial activity. The method is accurate, gives results within 48 h and can be automated. Test results for various types of cork, sampled before, during and after the manufacturing process of bottle closures, are provided. The use of CORA as a tool for the development of better production processes to limit cork infection by micro‐organisms and for advanced microbiological quality control is discussed.

1,1-Dimethylhydrazine, also known as unsymdimethylhydrazine (UDMH) and vinyl acetate (VA), are both classified by the International Agency for Research on Cancer as 2B carcinogens (possibly carcinogenic to humans) and listed as cigarette smoke constituents; however, there is little or no quantitative data available on them. For UDMH in cigarette smoke, neither a yield nor a method has been published. For VA, the most recent information on yields dates back to 1965. To bridge this gap, we have developed new gas chromatographic-mass spectrometric methods for both compounds to determine their yields in cigarette smoke. UDMH is determined by derivatization with 2-nitrobenzaldehyde in methanol and is not found in cigarette smoke at levels above the detection limit of 19 ng/cig. In further experiments, when UDMH is added to the smoke stream or air stream of lit or unlit cigarettes, the derivative 2-nitrobenzaldehyde-2,2-dimethylhydrazone is found only in the air stream of the unlit cigarettes. From this, we conclude that UDMH is either not formed during smoking at all or, if it is, it reacts immediately and quantitatively with other smoke constituents (e.g., aldehydes) and is therefore not detectable in cigarette smoke. VA is determined by trapping in acetone at −78°C and is found at a concentration of 270 ng/cig for a standard reference cigarette with a cellulose acetate filter (the reference cigarette 1R4F). In the literature, VA is reported at concentrations of 1.6 µg/cig for a cigarette with a cellulose acetate/charcoal filter and 4 µg/cig for a cigarette with a cellulose acetate filter and for an unfiltered cigarette.