bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear model predictive control with regulable computational cost
Authors: He Y. Q. , Han J. D. 
Published: February 2011

AbstractNonlinear model predictive control (NMPC) suffers from problems of closed loop instability and huge computational burden, which greatly limit its applications in real plants. In this paper, a new NMPC algorithm, whose stability is robust with respect to regulable computational cost, is presented. First, a new generalized pointwise min‐norm (GPMN) control, as well as its analytic form considering a super‐ball type input constraint, is given. Second, the GPMN controller is integrated into a normal NMPC algorithm as a structure of control input profile to be optimized, called GPMN enhanced NMPC (GPMN‐ENMPC). Finally, a numerical example is presented and simulation results exhibit the advantage of the GPMN‐ENMPC algorithm: computational cost can be regulated according to the computational resources with guaranteed stability.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Exponential stabilization of uncertain time‐delay linear systems with Markovian jumping parameters
Authors: Huang He , Feng Gang 
Published: February 2011

AbstractThis paper studies the exponential stabilization problem of uncertain time‐delay linear systems with Markovian jumping parameters. A novel delay decomposition approach is developed to derive delay‐dependent conditions under which the closed‐loop control system is mean square exponentially stable for all admissible uncertainties. It is shown that the feedback gain matrices and the decay rate can be obtained by solving coupled linear matrix inequalities. Moreover, the difficulties arising from searching for tuning parameters in the existing methods are overcome.Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Bewehrte Elastomerlager
Authors: Block Tobias 
Published: February 2011

AbstractDer Aufsatz erläutert das Tragverhalten bewehrter Elastomerlager unter kombinierten Druck‐ und Verdrehbeanspruchungen. Anhand von experimentellen Untersuchungen an 34 Probekörpern aus Chloropren‐ und Naturkautschuk mit Grundflächen zwischen 150 mm × 300 mm und 600 mm × 700 mm werden die maßgebenden Einflüsse auf die Höhe der rückstellenden Momente dargestellt. Dabei sind sowohl geometrische als auch äußere Einflüsse wie Temperatur und Belastungszustände Bestandteil der Analysen. Es wird gezeigt, dass die experimentellen Ergebnisse systematisch auf der unsicheren Seite liegende hohe Differenzen im Vergleich zu den normativen Berechnungen aufweisen. Auf Basis der Untersuchungen können die gewonnenen Erkenntnisse für die Entwicklung neuer Berechnungsmodelle für Rückstellmomente bewehrter Elastomerlager genutzt werden, die die Einflüsse aus zentrischer Druckbeanspruchung und Temperatur berücksichtigen.Laminated Elastomeric Bearings — Experimental investigation and new computational models. The report describes the load bearing behaviour of laminated elastomeric bearings under combined compression and uniaxial rotation. The main focus is the experimental description of the factors which influence the restoring moments. Beside the dimensions, the layer construction and the rubber mixture also external parameters like pressure, rotation angle and temperature have been taken into account. Over 500 single tests on 34 specimens with dimensions between 150 mm x 300 mm and 600 mm x 700 mm have been conducted which show major variation compared to the design values according to EN 1337‐3. On the basis of the experimental results new models for determining restoring moments of elastomeric bearings are developed. These models are able to consider the influence of the applied pressure as well as the nonlinearity of the rotation angle and the temperature.
Sicherstellung der Dauerhaftigkeit von Großbrücken aus Beton unter besonders korrosiven Einwirkungen
Authors: Raupach Michael 
Published: February 2011

AbstractBrücken aus Stahl‐ und Spannbeton werden heute i. d. R. für Nutzungsdauern von 100 Jahren geplant. Insbesondere bei Großbrücken liegen häufig Bedingungen vor, die besondere Lösungen erfordern, wie z. B. bei außerordentlichen korrosiven Beanspruchungen. Beispielhaft wird in diesem Aufsatz die Situation von Pfeilern im Meerwasser näher beleuchtet, die einem ständigen Chloridangriff unterliegen. Soll die Dauerhaftigkeit beispielsweise durch besonders hohe Qualität der Betondeckung erreicht werden, so sind besondere Nachweise zu führen, für die in den letzten Jahren interessante probabilistische Bemessungsansätze entwickelt wurden (s. z. B. [1] bis [3]). Ferner kann die Dauerhaftigkeitsprognose durch Einsatz von Monitoringsystemen kontinuierlich zugeschärft werden, so dass durch Anwendung der Sicherheitsbetrachtungen wirtschaftliche Lösungen ermöglicht werden. In dieser Veröffentlichung wird anhand der Pfeiler der mit 36 km längsten Meeresbrücke der Welt gezeigt, wie die Dauerhaftigkeit unter schwierigen Bedingungen über einen geplanten Nutzungszeitraum von 100 Jahren sichergestellt wird.Design for Durability of Large Concrete Bridges Under Severe Corrosive Attack. Nowadays bridges made of reinforced or prestressed concrete are usually designed for a service life‐time of 100a. Especially for large bridges often conditions are present, which require special solutions, as e. g. extra ordinarily corrosive exposure condi tions. In this paper exemplarily the situation of piles in seawater are discussed more in detail, which are subject to permanent chloride attack. If durability shall be achieved e. g. especially high quality of the concrete cover, special proofs have to be verified, which have been developed during recent years e. g. as probabilistic approaches (see e.g. [1]—[3]). Additionally the prognosis for durability can be updated continuously by using corrosion monitoring systems, allowing economic solutions by using special safety considerations.
Eine neue 10‐MN‐Prüfmaschine für großformatige Bauteile
Authors: Schladitz Frank , Hampel Torsten , Scheerer Silke , Ortlepp Sebastian 
Published: February 2011

AbstractIm Otto‐Mohr‐Laboratorium der TU Dresden wurde eine 10‐MN‐Säulenprüfmaschine errichtet. Sie dient zur Prüfung von Bauteilen, die eine Spannweite von maximal 15 m, eine Länge von 20 m, eine Breite von 2,5 m und eine Höhe von 3,75 m, bei einem maximalen Bauteilgewicht von 120 t, aufweisen können.Die Herausforderung beim Bau lag zum einen darin, dass die Prüfmaschine in einer geschlossenen Halle bei laufendem Betrieb errichtet werden musste, und zum anderen auf der Konstruktionsseite, da wegen des schlechten Baugrundes ein in sich geschlossener Kraftfluss erzielt werden musste. Dies wurde durch einen massiven Stahlrahmen und einen Fundamentbalken erreicht, der als beidseitiger Kragarm ausgeführt wurde. Der Fundamentbalken ist in hohem Grade vorgespannt und hochgradig bewehrt, was für die Herstellung einen selbstverdichtenden Beton erforderte. Aus Platzgründen erfolgte die Betonage und die Vorspannung des 275 t schweren Fundamentbalkens oberhalb der Fundamentgrube. Anschließend wurde der Balken über ein ausgeklügeltes Absenksystem in die 4 m tiefe Fundamentgrube abgesenkt und auf den Maschinenrahmen aufgesetzt.In the Otto‐Mohr‐Laboratory of the TU Dresden a 10‐MN‐ testing machine was mounted. It serves for testing components with a maximum span width of 15 m, length of 20 m, width of 2.50 m and height of 3.75 m, not exceeding a weight of 120 tons.The challenge was at the one hand having to build it in a closed hall with running operation and on the other hand the construction itself. Due to bad the building lot a self‐contained power transmission was needed. This was achieved by a massive steel frame and a ground beam being completed as a two‐sided cantilever. The ground beam is highly pre‐stressed and strongly reinforced which called for a self‐compacting concrete. Due to the limited space the concreting and pre‐stressing of the 275 tons ground beam was done above the foundation pit. After that the beam was lowered into the 4 m deep foundation pit and put onto the machine frame by an elaborated lowering system.
Involvement of midkine expression in the inhibitory effects of low‐frequency magnetic fields on cancer cells
Authors: Wang Tingting , Nie Yunzhong , Zhao Shuli , Han Yuwang , Du Youwei , Hou Yayi 
Published: February 2011

AbstractEffects of magnetic fields (MFs) on cancer cells may depend on cell type and exposure conditions. Gene expression levels are different among cancer cells. However, the effect of MFs on cancer cells with different gene expressions is still unclear. In this study, the cancer cell lines BGC‐823, MKN‐45, MKN‐28, A549, SPC‐A1, and LOVO were exposed to a low‐frequency MF. Specific parameters of MFs were determined. Furthermore, the potential of the MF to influence cancer cell growth with midkine (MK) expression was evaluated. Cell proliferation and cell cycle were detected using the CCK‐8 assay and flow cytometry. Cell ultrastructure was observed by transmission electron microscopy. BGC‐823 cells with over‐expression of MK (BGC‐MK cells) and stanniocalcin‐1 were generated by plasmid construction and transfection. Results showed that exposure to a 0.4‐T, 7.5 Hz MF inhibited the proliferation of BGC‐823, MKN‐28, A549, and LOVO cells, but not MKN‐45 and SPC‐A1 cells. Moreover, the inhibitory effect of the MF on BGC‐MK cells was lower (12.3%) than that of BGC‐823 cells (20.3%). Analysis of the cell cycle showed that exposure to the MF led to a significant increase in the S phase in BGC‐823 cells, but not in BGC‐MK cells. In addition, organelle morphology was modified in BGC‐823 cells exposed to the MF. These results suggest that exposure to a 0.4‐T, 7.5 Hz MF could inhibit tumor cell proliferation and disturb the cell cycle. The alteration of MK expression in cancer cells may be related to the inhibitory effect of the MF on these cells. Bioelectromagnetics 32:443–452, 2011. © 2011 Wiley‐Liss, Inc.
Effect of glutathione depletion, hyperthermia, and a 100‐mT static magnetic field on an hsp70/luc reporter system
Authors: Belton Michelle , Prato Frank S. , Carson Jeffrey J.L. 
Published: February 2011

AbstractHeat shock proteins, in particular hsp70, are induced under conditions of cellular stress. It has been reported that environmental stimuli such as hyperthermia, oxidative stress, and exposure to magnetic fields increase levels of hsp70. It has also been reported that hyperthermia in combination with magnetic field exposure results in a synergistic increase in hsp70 production. We tested the hypothesis that oxidative stress induced by glutathione (GSH) depletion in combination with static magnetic field (SMF) exposure will produce a similar synergistic increase in hsp70 production. We exposed cells to heat, SMF, and diethylmaleate (DEM), which depletes GSH levels alone and in combination with each other, and measured hsp70 production using an hsp70/luciferase reporter and mRNA levels using PCR. We found that treatment with DEM significantly reduced the rate of luciferase bioluminescence production, particularly in the presence of heat. There was no significant effect of a 100‐mT SMF exposure either alone or in combination with heat, DEM, or both on bioluminescence, however there was a significant interaction between SMF and DEM on hsp70 mRNA levels. Therefore, under our exposure conditions, GSH depletion reduced hsp70 levels but a synergistic effect of combining this stress with other external stimuli was only observed at the level of mRNA. Bioelectromagnetics 32:453–462, 2011. © 2011 Wiley‐Liss, Inc.
Structural dynamics of neuropeptide hPYY
Authors: Hegefeld Wendy A. , Kuczera Krzysztof , Jas Gouri S. 
Published: February 2011

AbstractWe have employed a combination of experiment and simulation to characterize the ensemble of structures sampled by human Peptide YY (hPYY), an important member of the neuropeptide Y family. Experimental structural characterization carried out with far UV circular dichroism spectroscopy and Fourier Transform‐Infrared measurements confirmed that the major feature of the secondary structure of hPYY is the α‐helix, encompassing about half the peptide residues, with smaller contributions from turn and β‐sheet like structures. The peptide undergoes thermal denaturation characterized by a melting temperature of 48°C with an enthalpy change of −24.5 kcal/mol and entropy change of −76.2 cal/(mol K). In our computational studies, based on a 4‐μsec MD trajectory generated with the AMBER03 potential, we found excellent agreement of the predicted features with experimental data, including a stable C‐terminal helix, a central turn and conservation of about 80% of measured long‐range NOE contacts. The main structural fluctuations involved partial helix unwinding and large‐scale motions of the N‐terminal. Our joint experimental/computational approach leads to several insights into the biological function of PYY. We conclude that the C‐terminal helix is crucial for the structural integrity of PYY. The structures and motions found in the simulations suggest microscopic explanations for observed changes in biological activity of the peptide upon mutation and truncation. We also performed microsecond‐length MD and replica‐exchange simulations of hPYY with the OPLS‐AA force field, for which computed structures did not agree well with experimental data, predicting significant loss of helicity and NOE contacts. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 487–502, 2011.
Systematic review and meta-analysis of survival following extracorporeal liver support
Authors: Stutchfield B M , Simpson K , Wigmore S J 
Published: February 2011

Abstract

Background
Extracorporeal liver support (ELS) systems offer the potential to prolong survival in acute and acute-on-chronic liver failure. However, the literature has been unclear on their specific role and influence on mortality. This meta-analysis aimed to test the hypothesis that ELS improves survival in acute and acute-on-chronic liver failure.

Methods
Clinical trials citing MeSH terms ‘liver failure’ and ‘liver, artificial’ were identified by searching MEDLINE, Embase and the Cochrane registry of randomized controlled trials (RCTs) between January 1995 and January 2010. Only RCTs comparing ELS with standard medical therapy in acute or acute-on-chronic liver failure were included. A predefined data collection pro forma was used and study quality assessed according to Consolidated Standards of Reporting Trials (CONSORT) criteria. Risk ratio was used as the effect size measure according to a random-effects model.

Results
The search strategy revealed 74 clinical studies including 17 RCTs, five case–control studies and 52 cohort studies. Eight RCTs were suitable for inclusion, three addressing acute liver failure (198 participants) and five acute-on-chronic liver failure (157 participants). The mean CONSORT score was 14 (range 11–20). Overall ELS therapy significantly improved survival in acute liver failure (risk ratio 0·70; P = 0·05). The number needed to treat to prevent one death in acute liver failure was eight. No significant survival benefit was demonstrated in acute-on-chronic liver failure (risk ratio 0·87; P = 0·37).

Conclusion
ELS systems appear to improve survival in acute liver failure. There is, however, no evidence that they improve survival in acute-on-chronic liver failure.
Single-incision laparoscopic right hemicolectomy (Br J Surg 2010; 97: 1881–1883)
Authors: Hewes J , Adamo M 
Published: February 2011

Abstract
The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (http://www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
CO2 from alcoholic fermentation for continuous cultivation of Arthrospira (Spirulina) platensis in tubular photobioreactor using urea as nitrogen source
Authors: Matsudo Marcelo C. , Bezerra Raquel P. , Converti Attilio , Sato Sunao , Carvalho João Carlos M. 
Published: February 2011

AbstractCarbon dioxide released from alcoholic fermentation accounts for 33% of the whole CO2 involved in the use of ethanol as fuel derived from glucose. As Arthrospira platensis can uptake this greenhouse gas, this study evaluates the use of the CO2 released from alcoholic fermentation for the production of Arthrospira platensis. For this purpose, this cyanobacterium was cultivated in continuous process using urea as nitrogen source, either using CO2 from alcoholic fermentation, without any treatment, or using pure CO2 from cylinder. The experiments were carried out at 120 μmol photons m−2 s−1 in tubular photobioreactor at different dilution rates (0.2 ≤ D ≤ 0.8 d−1). Using CO2 from alcoholic fermentation, maximum steady‐state cell concentration (2661 ± 71 mg L−1) was achieved at D = 0.2 d−1, whereas higher dilution rate (0.6 d−1) was needed to maximize cell productivity (839 mg L−1 d−1). This value was 10% lower than the one obtained with pure CO2, and there was no significant difference in the biomass protein content. With D = 0.8 d−1, it was possible to obtain 56% ± 1.5% and 50% ± 1.2% of protein in the dry biomass, using pure CO2 and CO2 from alcoholic fermentation, respectively. These results demonstrate that the use of such cost free CO2 from alcoholic fermentation as carbon source, associated with low cost nitrogen source, may be a promising way to reduce costs of continuous cultivation of photosynthetic microorganisms, contributing at the same time to mitigate the greenhouse effect. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
A laboratory experiment for teaching automation inspired by the smart home
Authors: Alayón S. , González C. , Toledo P. 
Published: February 2011

AbstractThis paper presents a laboratory experiment for teaching Automation. The objective of this project is to allow the students of the Technical Engineering Schools of the University of La Laguna (Spain) to learn the theoretical and practical fundamentals of Automation Systems through a laboratory experiment based on a home automation application. Automation plays an increasingly important role in the centred of Engineering; as a result, several subjects in the curriculum plan at the Engineering School focus on this discipline. In recent years, our teaching efforts have been centred on designing appealing and modern laboratory experiments. With these practical experiments, students acquire a basic knowledge of Automation, along with complementary knowledge of the latest developments in the field. The laboratory session presented in this article draws its inspiration from the Smart Home, a recent field in applied Automation. Due to the impossibility of carrying out the control of a smart installation in a real house, a simulation experiment was designed for educational tasks. A scale model of a house was built, and all the sensors, the actuators and the control system were adapted to this scale model. A Programmable Logic Controller was selected as the control system. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 21:E121–E131, 2013
Remote control of laboratory equipment for basic electronics courses: A LabVIEW‐based implementation
Authors: Popović Božidar , Popović Nataša , Mijić Danijel , Stankovski Stevan , Ostojić Gordana 
Published: February 2011

AbstractThis article describes a LabVIEW‐based implementation of remote control of laboratory equipment for basic Electronics courses. Remote control of laboratory equipment is demonstrated on an example of recording the amplitude characteristics of a T‐notch filter. Overview of traditional, virtual, and remote laboratory features is given, too. Real laboratory setup is presented, including hardware and software components and virtual instruments, as well as solutions for remote laboratory access. Finally, the way of putting the laboratory online and the course of the experiment are shown. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 21:E110–E120, 2013
Educational software tools for the kinematic analysis of mechanisms
Authors: Petuya Víctor , Macho Erik , Altuzarra Oscar , Pinto Charles , Hernandez Alfonso 
Published: February 2011

AbstractEducational software for the kinematic analysis of planar and spatial mechanisms is presented in this article. This general‐purpose kinematic software has been developed as a complement to Machine Theory lectures. The different modules integrated in the software compute and analyse various kinematic entities, which enable an advanced student to investigate the characteristics of a mechanism. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22: 72–86, 2014
Mass Transfer Behavior of Annular Ducts under Conditions with Superimposed Pulsating Flow
Authors: Zaki M. M. , Nirdosh I. , Sedahmed G. H. 
Published: February 2011

AbstractRates of mass transfer were measured at the inner surface of an annular duct by an electrochemical technique under developing flow conditions with superimposed pulsating flow. Variables like the frequency and amplitude of the pulsating flow, steady flow velocity, and annulus height were studied. The pulsating flow was found to enhance the rate of mass transfer by a factor ranging from 1.2 to 5.5 compared to the steady laminar flow value. The superimposed pulsating flow had only a minor effect on the rate of mass transfer under steady turbulent flow conditions. The pulsating flow reactor offers the advantage over steady flow annular reactor in that it can be operated at low flow rates to increase the residence time. The high residence time and high rate of mass transfer resulting from pulsation together increase the degree of conversion per pass as well as the reactor productivity.
Analysis and Optimization of Operating Parameters of a Membrane‐Electrode Assembly
Authors: Loh K. S. , Mohamad A. B. , Harahap N. , Kadhum A. A. H. , Daud W. R. W. 
Published: February 2011

AbstractHot‐pressing conditions for fabricating a membrane‐electrode assembly (MEA) were optimized. The key parameters were time, temperature, and pressure, varying from 1 to 5 min, 100 to 170 °C, and 21 to 93 kg cm–2, respectively. The MEAs were fabricated with 50 cm2 active electrode area and their performance was investigated using a fuel cell test station. The most suitable hot‐pressing time for MEA was 3 min, the optimized pressure and temperature for MEA fabrication were 21 kg·cm–2 and 130 °C with 1.6 A and 0.56 V. At 100 °C, the current and voltage of the produced MEAs were low due to the trapped liquid formed inside the electrode. However, at more than 150 °C, the obstructed/distorted polytetrafluoroethylene (PTFE) will block the pores inside the gas diffusion layer (GDL) and cause a loss of performance of the fuel cell. Physical properties of the GDL were observed using scanning electron microsopy (SEM). The GDL exhibited a uniform pore distribution after application of hot‐pressing.
Residence Time Distribution Studies in Microfluidic Mixing Structures
Authors: Bošković D. , Loebbecke S. , Gross G. A. , Koehler J. M. 
Published: February 2011

AbstractThe residence time distribution (RTD) characteristics of three microreactors containing different passive mixing structures, namely, a three dimensional serpentine structure, a split‐and‐recombine structure and a staggered herringbone structure, were investigated and compared. An experimental input‐response technique was applied which required deconvolution of the measured data by modeling of the RTD. The proposed technique provides useful information on optimized application and operation of microfluidic devices. The serpentine reactor and the split‐and‐recombine reactor show improvement in RTD behaviour, i.e., narrowing of RTD curves, at Re‐numbers > 30 due to effective transversal mixing and therefore reduced axial dispersion. In the case of the staggered herringbone structure, dead volumes could be observed which considerably affect the RTD.