Automatic compensation of thermal disturbances in machine tools

This study deals with a practical method of reducing the effects of thermal disturbances upon the accuracy of machine tools by controlled feed adjustment at the tool. The spatial displacement between the cutting tooI and the workpiece closely correlates with the temperature increase in the machine tool. The equation which describes the relation between the displacement and the temperature for a certain operating condition can be written as a linear combination of temperature values. One of the major conditions for the application of these equations is a good reproducibility of the thermal behaviour. The implementation of this method in a computerized numerical system is very simple. Experiments with lathes have shown that this way leads to reasonable results

Lipoxin A 4 (LxA 4 ) Promotes Reduction and Antibiotic Efficacy Against Pseudomonas aeruginosa Biofilm

Pseudomonas aeruginosa (P aeruginosa) is an opportunistic bacterium commonly found in wound infections and airways of cystic fibrosis patients P aeruginosa readily forms biofilms which can reduce the efficacy of antibiotics used to eradicate the pathogen We have previously shown that a Specialized Pro resolving Mediator ( Lipoxin A 4 (LxA 4 is a quorum sensing inhibitor which can reduce P aeruginosa virulence In this study, we examined the direct actions of LxA 4 and RvD 2 on P aeruginosa biofilm formation and virulence gene expression The influence of LxA 4 on antibiotic efficacy and the combined effects on biofilm formation were also investigated LxA 4 and RvD 2 reduced P aeruginosa biofilm formation and virulence gene expression LxA 4 increased ciprofloxacin inhibition on biofilm formation but did not affect ciprofloxacin’s action on non adherent bacteria On the other hand, LxA 4 increased bacterial killing action of imipenem but did not affect imipenem’s action on biofilm We also found that LxA 4 can increase ciprofloxacin’s bacterial killing ability in established biofilm Together these results suggest that LxA 4 has direct effects on P aeruginosa biofilm formation and can increase antibiotic efficacy directly

Methods for reducing thermal influences on the accuracy of machine tools

As the automation of manufacturing process is increasing and because higher machining accuracy is mandatory the disturbance variables influencing the performance of machine tools must be controlled. This paper attempts to give a survey of the present knowledge of the thermal behaviour of machine tools. The effects of thermal disturbances are described and compared with other disturbances. Common methods for the investigation of the thermal behaviour are presented. The methods for reducing thermal disturbances are classified under different topics. Known methods are summarized

Wissenschaft und Innovation: Wissenschaftsforschung Jahrbuch 2009

Technologische Innovationen sind kreative Reaktionen auf Veränderungen des Bedarfs an neuer Technik. Sie bilden ein System zur Durchsetzung des Neuen in einer technologisch ausgerichteten Zukunftswelt und erzeugen einen permanenten Druck zum Fortschritt. Eine Welt ohne technologische Innovationen wird es nicht geben. Sie dienen der Sicherung unseres Wohlstandes und bedürfen einer vielseitigen wissenschaftlichen Begleitforschung. Dabei werden Innovationsfähigkeiten in der Erwartung entwickelt, dass sich kreative Ideen als Innovationen auf dem Weltmarkt durchsetzten. Die zukünftige Gesellschaft wird auf das Leistungsvermögen ihrer industriellen Arbeitskultur angewiesen sein. Eine Steigerung des Arbeitsbedarfs kann nur durch Wachstum des industriellen Innovationspotenzials erreicht werden. Die Gesellschaft für Wissenschaftsforschung hat sich dieser Fragestellung angenommen und sie im Rahmen ihrer Jahrestagung im Produktionstechnischen Zentrum der Technischen Universität Berlin am 27. und 28. März 2009 unter dem Thema „Wissenschaft und Innovation“ analysiert und diskutiert. Dabei ist es gelungen, theoretische Überlegungen mit historischen und aktuellen Fakten zu verbinden. Die Ergebnisse dieser Tagung werden in diesem Jahrbuch der Gesellschaft für Wissenschaftsforschung dem interessierten Leser vorgestellt.Peer Reviewe

Experimental study of a compact unglazed Solar Thermal Facade (STF) for energy-efficient buildings

This paper presents a real-time experimental measurement of a novel compact unglazed solar thermal facade (STF) system at outdoor environment in Shanghai, China for about a whole summer week. It demonstrates the daily average solar thermal efficiency fluctuated from 40% to 45.5%. The overall result indicates the advantages of the STF with simple structure, low cost and high feasibility in architectural design for energy-efficient building application, especially at future district or city levels

A Preliminary Report on the Role of Lipoxin A4 in Reinstating the Blood-Brain Barrier Integrity in a Rodent Model of Acute Inflammation with Impaired Cerebrovasculature

Background: The blood-brain barrier (BBB) is responsible for maintaining brain homeostasis and ultimately proper neuronal function. Disruption of the BBB, leading to increased BBB permeability, has been reported in several neurodegenerative diseases, including Alzheimer’s disease (AD) and traumatic brain injury (TBI). Lipoxins (LXs) are a class of arachidonate-derived eicosanoids, which are a class of specialized pro-resolving lipid mediators (SPMs). SPMs are known to inhibit immune response through inhibition of cellular infiltration, downregulation of pro-inflammatory mediators and upregulation of anti-inflammatory mediators. Hence, LXs are recognized as “breaking signals” in the inflammatory process. One form of LXs, Lipoxin A4 (LXA4), has been found to decreased production of proinflammatory mediators, inhibit neutrophils chemotaxis and infiltration to the site of injury, and promote the phagocytic clearance of debris by macrophages. Therefore, LXA4 serves a critical role in resolution of inflammatory process by regulating the activation of monocytes and modulating the generation of reactive oxygen species (ROS). Hypothesis: LXA4 treatment reinstates the BBB integrity in a rodent model of acute BBB breakdown and inflammation. Methods: Nine-month-old female Sprague Dawley rats were given an intravenous (IV) injection of 15 mg/kg lipopolysaccharide (LPS) through the tail for inducing acute inflammation and BBB breach. After three hours, the rats were injected with 9 µg/kg LXA4 or Saline (Vehicle control). Four treatment groups were thus developed: LPS only, LPS/LXA4, LXA4 only, and Saline only. Animals were euthanized at 24 hours of LPS treatment and brain samples were processed for paraffin-embedded sections and immunohistochemistry. Sections comprising of hippocampus and cortical regions were selected for detection of impaired BBB as demonstrated by the extravasation of immunoglobulin G (IgG) and IBA1 (microgliosis marker). The area of the cerebral cortex and number of cortical blood vessels presenting with IgG extravasation were estimated and compared between treatment groups. Similarly, IBA1 immunoreactivity was quantified using Color Deconvolution V9 tool of Aperio ImageScope (Leica BIOSYSTEMS). Results: LXA4 treatment following LPS injection demonstrated decrease in the extent of IgG leak compared to LPS only group. Likewise, we observed significant decrease in microgliosis in LPS-LXA4 group compared to LPS only. Conclusion: These preliminary results demonstrate potential beneficial effects of LXA4 in reinstating BBB integrity and reducing neuroinflammation in rat model of acute BBB breach and inflammation

Influence of geometrical parameters of convergent sleeve on the value of limit stress

This paper presents the results of research on improving the effectiveness of the agglomeration process. Improving effectiveness was obtained as a result of the application of the convergent sleeve. The sleeve is mounted before the multi-holes die in the dry ice agglomeration machine. The empirical part of the paper presents the results of research on which FEM model was based. The numerical part of research presents the FEM model of the agglomeration process. The FEM model with a known uncertainty level was used to determine the influence of geometrical parameters of the sleeve on the limit value of the agglomeration forces. The model will be one of the starting points for the design and construction of the machine for the compaction and granulation of dry ice