Fuel cell/gas turbine system performance studies

Because of the synergistic effects (higher efficiencies, lower emissions) of combining a fuel cell and a gas turbine into a power generation system, many potential system configurations were studied. This work is focused on novel power plant systems by combining gas turbines, solid oxide fuel cells, and a high-temperature heat exchanger; these systems are ideal for the distributed power and on- site markets in the 1-5 MW size range

Harmonic assessment based adjusted current total harmonic distortion

Power systems suffer from harmonic distortion and extra ohmic losses associated with them. Moreover, all harmonic frequencies are mostly assumed to have the same effect on the system losses. However, the frequency-dependency of the resistances should be taken into account, so that the apparent power and the power factor have to considerably reflect power losses under nonsinusoidal conditions. In this paper, the difference between unweighted and weighted non-sinusoidal losses, is addressed. A new harmonic-adjusted total harmonic distortion definition is proposed for both voltage and current. Besides, a new formula that relates the proposed harmonic-adjusted total harmonic distortion and a generalised harmonic derating factor definition of the frequency dependent losses of the power transmission and distribution equipment, is derived. An optimal C-type passive filter design for harmonic mitigation and power factor correction based on the minimisation of the proposed harmonic-adjusted total harmonic distortion for a balanced nonsinusoidal system is introduced. A comparative study of the proposed filter design based on the new harmonic-adjusted definition, and a conventional filter design based on standard total harmonic distortion definition, is presented

DC Link Stabilized Field Oriented Control of Electric Propulsion Systems

Induction motor based electric propulsion systems can be used in a wide variety of applications including locomotives, hybrid electric vehicles, and ships. Field oriented control of these drives is attractive since it allows the torque to be tightly and nearly instantaneously controlled. However, such systems can be prone to negative impedance instability of the DC link. This paper examines this type of instability and sets forth a readily implemented albeit nonlinear control strategy to mitigate this potential problem

Culture bag systems for clinical applications of adult human neural crest-derived stem cells

Introduction Facing the challenging treatment of neurodegenerative diseases as well as complex craniofacial injuries such as those common after cancer therapy, the field of regenerative medicine increasingly relies on stem cell transplantation strategies. Here, neural crest-derived stem cells (NCSCs) offer many promising applications, although scale up of clinical-grade processes prior to potential transplantations is currently limiting. In this study, we aimed to establish a clinical-grade, cost-reducing cultivation system for NCSCs isolated from the adult human nose using cGMP-grade Afc-FEP bags. Methods We cultivated human neural crest-derived stem cells from inferior turbinate (ITSCs) in a cell culture bag system using Afc-FEP bags in human blood plasma-supplemented medium. Investigations of viability, proliferation and expression profile of bag-cultured ITSCs were followed by DNA-content and telomerase activity determination. Cultivated ITSCs were introduced to directed in vitro differentiation assays to assess their potential for mesodermal and ectodermal differentiation. Mesodermal differentiation was determined using an enzyme activity assay (alkaline phosphatase, ALP), respective stainings (Alizarin Red S, Von Kossa and Oil Red O), and RT-PCR, while immunocytochemistry and synaptic vesicle recycling were applied to assay neuroectodermal differentiation of ITSCs. Results When cultivated within Afc-FEP bags, ITSCs grew three-dimensionally in a human blood plasma-derived matrix, thereby showing unchanged morphology, proliferation capability, viability and expression profile in comparison to three dimensionally-cultured ITSCs growing in standard cell culture plastics. Genetic stability of bag-cultured ITSCs was further accompanied by unchanged telomerase activity. Importantly, ITSCs retained their potential to differentiate into mesodermal cell types, particularly including ALP-active, Alizarin Red S-, and Von Kossa-positive osteogenic cell types, as well as adipocytes positive in Oil Red O assays. Bag culture further did not affect the potential of ITSCs to undergo differentiation into neuroectodermal cell types coexpressing β-III-tubulin and MAP2 and exhibiting the capability for synaptic vesicle recycling. Conclusions Here, we report for the first time the successful cultivation of human NCSCs within cGMP-grade Afc-FEP bags using a human blood plasma-supplemented medium. Our findings particularly demonstrate the unchanged differentiation capability and genetic stability of the cultivated NCSCs, suggesting the great potential of this culture system for future medical applications in the field of regenerative medicine

1,8-cineol potentiates IRF3-mediated antiviral response in human stem cells and an ex vivo model of rhinosinusitis

Common cold is one of the most frequent human inflammatory diseases caused by viruses and can facilitate bacterial super-infections resulting in sinusitis or pneumonia. The active ingredient of the drug Soledum, 1,8-cineole, is commonly applied for treating inflammatory diseases of the respiratory tract. However, the potential of 1,8-cineole for treating primary viral infections of the respiratory tract remains unclear. In the present study, we demonstrate for the first time that 1,8-cineole potentiates Poly(I:C)-induced activity of the anti-viral transcription factor Interferon Regulatory Factor 3, while simultaneously reducing pro-inflammatory NF-κB-activity in human cell lines, inferior turbinate stem cells (ITSCs) and ex vivo cultivated human nasal mucosa. Co-treatment of cell lines with Poly(I:C) and 1,8-cineole resulted in significantly increased IRF3 reporter gene activity compared to Poly(I:C) alone, whereas NF-κB-activity was reduced. Accordingly, 1,8-cineole- and Poly(I:C)-treatment led to increased nuclear translocation of IRF3 in ITSCs and a human ex vivo model of rhinosinusitis compared to the Poly(I:C)-treated approach. Nuclear translocation of IRF3 was significantly increased in ITSCs and slice cultures treated with LPS and 1,8-cineole compared to the LPS-treated cells mimicking bacterial infection. Our findings strongly suggest that 1,8-cineole potentiates the antiviral activity of IRF3 in addition to its inhibitory effect on pro-inflammatory NF-κB-signalling and may thus broaden its field of application

TNFA deletion alters apoptosis as well as caspase 3 and 4 expression during otitis media

Abstract Background Tumor necrosis factor (TNFA) is the canonical member of the TNF superfamily, which plays a major role in both inflammation and apoptosis. To evaluate the role of TNFs in otitis media (OM), the most common disease of childhood, we evaluated middle ear (ME) expression of genes encoding the TNF and TNF receptor superfamilies during bacterial OM in the mouse, characterized OM in TNFA-deficient mice, and assessed apoptosis during OM in normal versus TNF-deficient MEs. Results TNFs and TNF receptors were broadly regulated during OM, with TNFA showing the highest level of up-regulation. TNF deficient mice exhibited mucosal hyperplasia even in the absence of infection and exuberant growth of the mucosa during OM, including the formation of mucosal polyps. Mucosal recovery during OM was also delayed, in parallel with a delay in mucosal apoptosis and reduced caspase gene expression. Conclusions The TNF and TNF receptor superfamilies mediate both inflammation and apoptosis during OM. TNF appears to be critical for the maintenance of mucosal architecture in both the normal and infected ME, since excessive accumulation of mucosal tissue is seen in TNFA-/- MEs both before and after bacterial inoculation of the ME. TNFA is also required for appropriate regulation of caspase genes

Multiphase induction motor drives - a technology status review

The area of multiphase variable-speed motor drives in general and multiphase induction motor drives in particular has experienced a substantial growth since the beginning of this century. Research has been conducted worldwide and numerous interesting developments have been reported in the literature. An attempt is made to provide a detailed overview of the current state-of-the-art in this area. The elaborated aspects include advantages of multiphase induction machines, modelling of multiphase induction machines, basic vector control and direct torque control schemes and PWM control of multiphase voltage source inverters. The authors also provide a detailed survey of the control strategies for five-phase and asymmetrical six-phase induction motor drives, as well as an overview of the approaches to the design of fault tolerant strategies for post-fault drive operation, and a discussion of multiphase multi-motor drives with single inverter supply. Experimental results, collected from various multiphase induction motor drive laboratory rigs, are also included to facilitate the understanding of the drive operatio

IceCube - the next generation neutrino telescope at the South Pole

IceCube is a large neutrino telescope of the next generation to be constructed in the Antarctic Ice Sheet near the South Pole. We present the conceptual design and the sensitivity of the IceCube detector to predicted fluxes of neutrinos, both atmospheric and extra-terrestrial. A complete simulation of the detector design has been used to study the detector's capability to search for neutrinos from sources such as active galaxies, and gamma-ray bursts.Comment: 8 pages, to be published with the proceedings of the XXth International Conference on Neutrino Physics and Astrophysics, Munich 200

Molecular targeted therapies in head and neck cancer - An update of recent developements -

Targeted therapies have made their way into clinical practice during the past decade. They have caused a major impact on the survival of cancer patients in many areas of clinical oncology and hematology. Indeed, in some hematologic malignancies, such as chronic myelogenous leukemia or non-Hodgkin's lymphomas, biologicals and antibodies specifically designed to target tumour-specific proteins have revolutionized treatment standards. In solid tumours, new drugs targeting EGF- or VEGF- receptors are now approved and are entering clinical practise for treatment of colon, lung, kidney and other cancers, either alone or in combination with conventional treatment approaches

Results from the Antarctic Muon and Neutrino Detector Array (AMANDA)

We show new results from both the older and newer incarnations of AMANDA (AMANDA-B10 and AMANDA-II, respectively). These results demonstrate that AMANDA is a functioning, multipurpose detector with significant physics and astrophysics reach. They include a new higher-statistics measurement of the atmospheric muon neutrino flux and preliminary results from searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, gamma-ray bursters and diffuse sources producing muons in the detector, and diffuse sources producing electromagnetic or hadronic showers in or near the detector.Comment: Invited talk at the XXth International Conference on Neutrino Physics and Astrophysics (Neutrino 2002), Munich, Germany, May 25-30, 200