Biomass effects on oxygen transfer in membrane bioreactors

Ten biomass samples from both municipal and industrial pilot and full scale submerged membrane bioreactors (MBRs) with mixed liquor suspended solids concentrations (MLSS) ranging from 7.2 to 30.2g L(-1) were studied at six air-flow rates (0.7, 1.3, 2.3, 3, 4.4 and 6m(3)m(-3)h(-1)). Statistical analyses were applied to identify the relative impacts of the various bulk biomass characteristics on oxygen transfer. Of the biomass characteristics studied, only solids concentration (correlated with viscosity), the carbohydrate fraction of the EPS (EPS(c)) and the chemical oxygen demand (COD) concentration of the SMP (SMP(COD)) were found to affect the oxygen transfer parameters k(L)a(20) (the oxygen transfer coefficient) and alpha-factor. The relative influence on k(L)a(20) was MLSS>aeration>EPS(c)>SMP(COD) and on alpha-factor was MLSS>SMP(COD)>EPS(c)>aeration. Both k(L)a(20) and alpha-factor increased with increasing aeration and EPS(c) and decreased with increasing MLSS and SMP(COD). MLSS was found to be the main parameter controlling the oxygen transfer.     

Development and evaluation of a just-in-time support system

OBJECTIVE: To lay the foundation for a framework of just-in-time support (JITS) for novices dealing with urgent, unfamiliar tasks, and to evaluate a JITS system. BACKGROUND: More than 350,000 people die annually of cardiac arrest in the United States. In response, automated defibrillators are advocated that, unfortunately, do not provide important respiratory support. This paper presents elements of a framework for a JITS system that instructs a lay responder to follow a treatment protocol for integrating respiratory support with the use of an automatic external defibrillator. METHOD: We simulated a medical emergency using a high-fidelity patient simulator and asked participants to care for the patient. Results: When using a paper-based NASA treatment protocol, participants made more errors and took longer to stabilize the injured person than when using the JITS system. CONCLUSION: These findings demonstrate the benefit of a JITS system to instruct novices in unfamiliar tasks. APPLICATION: The JITS system has the potential to improve the treatment outcome of victims of cardiac arrest. The JITS framework can be applied to many situations in which novices deal with urgent tasks without expertise available.     

The right picture is worth a thousand numbers: data displays in anesthesia

OBJECTIVE: To review the literature on data displays in anesthesia identifying issues and developing design recommendations. BACKGROUND: Unexpected incidents are common in critical care medicine. Adverse outcomes are frequently the catastrophic endpoints of an "evolving" chain of subtle incidents. One strategy to reduce the likelihood of an adverse patient outcome during anesthesia is to improve the anesthesiologist's ability to detect, diagnose, and treat critical incidents. METHOD: A literature review and analysis of data displays. RESULTS: Current numerical and waveform displays do not support anesthesiologists optimally. An alternative is graphical displays that functionally integrate variables into objects. In a well-designed graphic object, deviations from normal are shown by distortions in the object's symmetry. The emerging patterns that result from distorted symmetry facilitate the correct diagnosis. When treatment is effective, an object's shape is restored to normal. Graphical displays can be an effective tool in supporting anesthesiologists' situation awareness. CONCLUSION: Problems related to graphical displays have delayed their use in anesthesia, including the lack of conclusive clinical evidence of their value. However, currently more evidence is accumulating that graphical displays have the potential to improve clinical performance. The successful development of these graphical displays takes into account task requirements, a user's perceptual processes, and task-specific cognition. APPLICATION: This paper provides suggestions for the development of more effective displays in anesthesiology. Graphical displays can increase the anesthesiologist's situation awareness and improve clinical performance. Clinical use of these displays has the potential to significantly improve patient safety.     

Drug delivery as control task: improving performance in a common anesthetic task

OBJECTIVE: To conceptualize delivery of anesthesia as a control task, similar to control tasks in nonmedical domains, and to evaluate how presentation of new information and feedback affects task performance. BACKGROUND: In anesthesia, integrated monitors that show intravenous drug and effect-site concentrations in a patient currently do not exist. However, using real-time displays of intravenous anesthetic concentrations and effects could significantly enhance intraoperative clinical performance. Pharmacological models are available to estimate past, present, and future drug concentrations in the brain and to predict the drug's physiological effects. A display that integrates pharmacological models and visualizes drug concentrations was developed and tested to see if this drug display significantly improved clinical performance. METHOD: Thirty-three anesthesiologists with different levels of expertise administered anesthesia to simulated patients in a high-fidelity patient simulator. The experimental group used a drug display that visualized drug concentrations in real time, whereas the control group administered drugs without this information. RESULTS: Anesthesiologists using the drug display achieved better hemodynamic control of the simulated patient than did the control group. Similarly, the drug display enabled anesthesiologists to wake up and reanimate the patient faster. CONCLUSION: Visual feedback of drug concentrations leads to superior performance in the delivery of anesthesia. Drug delivery can be conceptualized within a control theoretical framework. Finally, the drug display has significant clinical potential to increase patient safety. APPLICATION: Clinical performance in delivering anesthesia depends on feedback. By providing this feedback, the drug display supports clinicians' ability to more precisely and safely administer anesthesia.     

Entwicklungstendenzen im Bereich der Fahrzeugelektronik

Applications in the automobile sector, wired or unwired, are today often integrated into a network of sensors and actors as well as in service functions, visualization, and entertainment. The paper presents an innovative platform, which is applicable for automotive and automation applications. & IT systems for automobiles and for business applications took a very different development direction.

? In the automotive sector a lot of proprietary IT systems have been developed.

? The increasing requirements of automotive applications require platform concepts, which are based on open standards.

     

Total water vapor column retrieval from MSG-SEVIRI split window measurements exploiting the daily cycle of land surface temperatures

A physically based algorithm for the retrieval of total water vapor column (TWC) over cloud-free land surfaces proposed by Kleespies and McMillin [Kleespies, J.T., McMillin L.M. (1990). Retrieval of precipitable water from observations in the Split Window over varying surface temperatures. Journal of Applied Meteorology, 29, 851-862.] is evaluated and extended for use in atmospheric correction and surface irradiance calculation schemes. Thermal infrared split window channels at 10.8 and 12.0 μm of the MSG-SEVIRI (Meteosat Second Generation-Spinning Enhanced Visible and Infrared Imager) instrument are used. The proposed algorithm takes advantage of the improved measurement capabilities of the MSG-SEVIRI instrument with its 15 min temporal resolution and its radiometric accuracy of 0.25 K and 0.37 K in the 10.8 and 12.0 μm channels. The temporal resolution allows exploitation of the daily land surface temperature variation. There is no further need for explicit auxiliary information on air and land surface temperatures, which is difficult to obtain on an operational basis. Updated coefficients for the split window parameterization are derived based on simulations of ‘top-of-atmosphere’ SEVIRI brightness temperatures for the globally representative Thermodynamic Initial Guess Retrieval (TIGR3) set of radiosonde profiles. It turns out that the linear dependency on the transmission ratio in both split window channels as originally proposed by Kleespies & McMillin [Kleespies, J.T., McMillin L.M. (1990). Retrieval of precipitable water from observations in the Split Window over varying surface temperatures. Journal of Applied Meteorology, 29, 851-862.] has to be extended towards a non-linear approach in order to make it applicable to the full range of global atmospheric conditions. Sensitivity studies reveal that the parameterization relies on the availability of input brightness temperatures with a variation larger than approximately 5 K during the daily cycle. The new TWC algorithm was tested with MSG-SEVIRI data for European and African regions for the period March-August 2004 and compared with radiosonde data. The results show that the algorithm is capable of producing TWC values with a mean bias of − 0.2 mm and an RMSE of 6.8 mm. From the total amount of 2583 coincidences for all viewing zenith angles both for winter and summer conditions, 82% were within a ± 5 mm and 94% were within a ± 10 mm difference interval between MSG-based and radiosonde-based TWC. A second comparison to European GPS measurements for the same period from March to August 2004 reveals a bias of − 3.0 mm and an RMSE of 6.0 mm. This result is obtained for 11 UTC GPS measurements which proved to match best the MSG-TWC values. Comparing MSG-TWC to daily cloud-free mean GPS values shows a lower bias of − 2.56 mm and an increased RMSE of 6.6 mm. These findings support the usefulness of the new MSG-based algorithm for surface irradiance calculations and atmospheric correction purposes.     

Cure monitoring of photosensitive resins by photo-dynamic mechanical analysis

A new technique, photo-dynamic mechanical analysis, was developed to monitor the cure of photosensitive resins. In this technique, the resin is dispensed on a low modulus substrate and the force needed to maintain a prescribed elongation on the sample is measured while the sample is exposed to an ultraviolet source. The force increases with the extent of cure and reaches a plateau when the resin is fully cured. Photo-dynamic mechanical analysis was found to be a rapid, continuous, and reliable technique to monitor the extent of cure of photopolymerizable resins. A finite element analysis was developed to calculate the resin modulus from the experimental force data. Thus, it was possible to monitor the resin modulus from the liquid state to the solid state.     

Hepatobiliary toxicity of total parenteral nutrition in adults

The enzymology and clinical manifestations of total parenteral nutrition (TPN)-induced liver abnormalities have been investigated extensively. The cause, pathogenesis, and treatment of TPN-related hepatic and biliary dysfunction in adults still are not well understood, however. The findings of experimental studies in animals has not necessarily correlated with the human data, and there have been few prospective, randomized controlled trials examining the mechanism, cause, or treatment of TPN-induced hepatobiliary toxicity in adults. This article examines the animal models of pathogenesis and treatment of TPN-induced intrahepatic and extrahepatic abnormalities, and provides a discussion of abnormalities seen in humans.     

Increased number of substitutions in the D-loop of mitochondrial DNA in the sudden infant death syndrome

The purpose of the present study was to investigate substitutions in the D-loop of mitochondrial DNA (mtDNA) in sudden infant death syndrome (SIDS) and controls, since several observations indicate the involvement of mtDNA mutations in SIDS. These include elevated levels of vitreous humour hypoxanthine in SIDS victims, familial clustering without mendelian traits, and observations of increased sleepiness and a lower activity score in infants who later succumbed to SIDS. Eighty-two cases of SIDS and 133 controls were investigated and the D-loop sequences were recorded in the base-pair range 16055-16500 in the mtDNA sequence. The sequencing was carried out using the Applied Biosystems Sequenase dye terminator method and a ABD373A sequencer. The recorded D-loop sequences were compared with the Cambridge sequence and differences were recorded as substitutions. The SIDS cases had a tendency towards a higher substitution rate in the D-loop than the controls (p = 0.088). This observation makes it interesting to search for deleterious mutations in other locations in the mtDNA.