Evaluation of the thermal and hydraulic performances of a very thin sintered copper flat heat pipe for 3D microsystem packages

The reported research work presents numerical studies validated by experimental results of a flat micro heat pipe with sintered copper wick structure. The objectives of this project are to produce and demonstrate the efficiency of the passive cooling technology (heat pipe) integrated in a very thin electronic substrate that is a part of a multifunctional 3-D electronic package. The enhanced technology is dedicated to the thermal management of high dissipative microsystems having heat densities of more than 10W/cm2. Future applications are envisaged in the avionics sector. In this research 2D numerical hydraulic model has been developed to investigate the performance of a very thin flat micro heat pipe with sintered copper wick structure, using water as a refrigerant. Finite difference method has been used to develop the model. The model has been used to determine the mass transfer and fluid flow in order to evaluate the limits of heat transport capacity as functions of the dimensions of the wick and the vapour space and for various copper spheres radii. The results are presented in terms of liquid and vapour pressures within the heat pipe. The simulated results are validated by experiments and proved that the method can be further used to predict thermal performance of the heat pipe and to optimise its design.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Bulgarian Libraries After the Fall of Communism

Presenter: Stefka Tzanova, York College, CUNY (City University of New York). - "Bulgarian Libraries After the Fall of Communism"

Neuromonitoring und Neuroprotektion in der Kardioanästhesie: Bundesweite Umfrage des Arbeitskreises Kardioanästhesie der Deutschen Gesellschaft für Anästhesiologie und Intensivmedizin e.V

Zusammenfassung: Fragestellung: Primäres Ziel dieser in deutschen kardioanästhesiologischen Abteilungen durchgeführten Umfrage war, die aktuelle Praxis von Neuromonitoring und Neuroprotektion zu erheben. Methodik: Zwischen Oktober 2007 und Januar 2008 wurden hierzu Daten mithilfe eines 26Punkte umfassenden, anonymisierten Fragebogens erhoben. Ermittelt wurden: präoperative Evaluation der hirnversorgenden Arterien, intraoperatives Neuromonitoring, zerebroprotektive Maßnahmen, Perfusionsmanagement während extrakorporaler Zirkulation, postoperative Erhebung des neurologischen Status und Aus-/Weiterbildung im zerebralen Monitoring. Ergebnisse: 55% der Fragebögen wurden mit folgenden Angaben beantwortet: präoperative Duplexsonographie der Hirngefäße in 90% der Kliniken; intraoperatives Neuromonitoring mithilfe der Elektroenzephalographie (EEG; 60%) bei Typ-A-Dissektionen (38,1%), bei elektiven Operationen an der thorakalen bzw. thorakoabdominellen Aorta (34,1% resp. 31,6%) und in der Karotischirurgie (43,2%), weiterhin Einsatz der Nahinfrarotspektroskopie (40%), Ableitung evozierter Potenziale (30%) und transkranielle Dopplersonographie (17,5%). Auch kombinierte Verfahren wurden angewandt. Während Bypass-, Klappen und minimal-invasiven Operationen erfolgt meistens kein Monitoring des Zentralnervensystems. Zur Zerebroprotektion werden die Kühlung des Patienten an Herz-Lungen-Maschine (HLM; 100%), externe Kühlung des Kopfes (65%), Gabe von Kortikosteroiden (58%), Barbituraten (50%) und Antiepileptika (10%) eingesetzt. Als neuroprotektive Anästhesieverfahren gelten Inhalationsanästhesie (32,5%; Favorit: Sevofluran 76,5%) und total intravenöse Anästhesie (20%; Favoriten: Propofol und Barbiturate mit je 46,2%). Standardmäßig kühlen 72,5% der Krankenhäuser die Patienten bei Operationen mit Herz-Kreislauf-Stillstand, 37,5% bei allen Operationen mit HLM. Unter normothermen Bedingungen entspricht in 84,6% der Kliniken der HLM-Fluss dem errechneten Herzzeitvolumen (HZV), der anzustrebende mittlere arterielle Druck (MAP) liegt bei 60-70mmHg (43,9%) bzw. 50-60mmHg (41,5%). Bei einer Körpertemperatur unter 18°C wird der HLM-Fluss unter das errechnete HZV gesenkt (70%), während in 27% der Kliniken normotherme Flussraten gefahren werden. Der bevorzugte MAP unter Hypothermie liegt zwischen 50 und 60mmHg (59%). Intraoperatives Neuromonitoring wird im Narkoseprotokoll (77%) dokumentiert. Postoperativ wird der neurologische Status in 42,5% der Kliniken durch individuelle Einschätzung des Anästhesisten (77,5%) erhoben. Fortbildungen zum Thema Neuromonitoring werden in 32,5% der Kliniken regelmäßig organisiert, in 37,5% dem Arzt selbst überlassen. Schlussfolgerung: Das kardioanästhesiologische Vorgehen in Deutschland ist im Bereich Neuromonitoring und neuroprotektive Therapie nicht standardisiert. Ein "multimodales Neuromonitoring" wäre wünschenswer

Synthesis, Characterization, and Cytotoxic Activity of New Lanthanum(III) Complexes of Bis-Coumarins

Complexes of lanthanum(III) with bis-coumarins: 3,3′-benzylidene-bis(4-hydroxy-2H-1-benzopyran-2-one) (H(2)L1) and bis(4-hydroxy-2-oxo-2H-chromen-3-yl)-(1H-pyrazol-3-yl)-methane (H(2)L2) were synthesized by reaction of lanthanum(III) salt and the ligands, in amounts equal to metal : ligand molar ratio of 1 : 2. The complexes were prepared by adding an aqueous solution of lanthanum(III) salt to an aqueous solution of the ligand subsequently raising the pH of the mixture gradually to circa 5.0 by adding dilute solution of sodium hydroxide. The lanthanum(III) complexes with bis-coumarins were characterized by different physicochemical methods—elemental analysis, IR-, (1)H-, and (13)C-NMR-spectroscopies, and mass spectral data. The spectral data of lanthanum(III) complexes were interpreted on the basis of comparison with the spectra of the free ligands. This analysis showed that in the La(III) complexes, the ligands coordinated to the metal ion through both deprotonated hydroxyl groups. On the basis of the ν(C=O) red shift observed, participation of the carbonyl groups in the coordination with the metal ion was also suggested. In the present study, we performed a cytotoxic-effects screening of the lanthanum complexes with H(2)L1 and H(2)L2 in a panel of human tumor cell lines, using the standard MTT-dye reduction assay for cell viability. The panel consisted of the acute myeloid leukemia-derived HL-60 and the chronic myeloid leukemia-derived BV-173. Following a 24- hour treatment of BV-173 cells with lanthanum complex of H(2)L1 at 100 or 200 μM led to a DNA-laddering. The findings suggest that the observed cytotoxicity of the lanthanum complex of H(2)L1 on BV-173 is at least partly mediated through induction of programmed cell death

Evaluation of the McGrath MAC and Macintosh laryngoscope for tracheal intubation in 2000 patients undergoing general anaesthesia : the randomised multicentre EMMA trial study protocol

Introduction The direct laryngoscopy technique using a Macintosh blade is the first choice globally for most anaesthetists. In case of an unanticipated difficult airway, the complication rate increases with the number of intubation attempts. Recently, McGrath MAC (McGrath) video laryngoscopy has become a widely accepted method for securing an airway by tracheal intubation because it allows the visualisation of the glottis without a direct line of sight. Several studies and case reports have highlighted the benefit of the video laryngoscope in the visualisation of the glottis and found it to be superior in difficult intubation situations. The aim of this study was to compare the first-pass intubation success rate using the (McGrath) video laryngoscope compared with conventional direct laryngoscopy in surgical patients. Methods and analysis The EMMA trial is a multicentre, open-label, patient-blinded, randomised controlled trial. Consecutive patients requiring tracheal intubation are randomly allocated to either the McGrath video laryngoscope or direct laryngoscopy using the Macintosh laryngoscope. The expected rate of successful first-pass intubation is 95% in the McGrath group and 90% in the Macintosh group. Each group must include a total of 1000 patients to achieve 96% power for detecting a difference at the 5% significance level. Successful intubation with the first attempt is the primary endpoint. The secondary endpoints are the time to intubation, attempts for successful intubation, the necessity of alternatives, visualisation of the glottis using the Cormack & Lehane score and percentage of glottic opening score and definite complications. Ethics and dissemination The project was approved by the local ethics committee of the Medical Association of the Rhineland Palatine state and Westphalia-Lippe. The results of this study will be made available in the form of manuscripts for publication and presentations at national and international meetings

Innovaciones en la educación superior en Electrónica a través del desarrollo de un entorno de aprendizaje basado en simulaciones y conducido por desarrollo de proyectos

This paper describes innovations in Bulgarian higher engineering education - distance learning, virtual technologies and multimedia in electronics as outcomes of a three years international project. In compliance with the project objectives a new unit - an Innovative Center for Open & Distance Learning and Multimedia - was established at the Faculty of Electronics. A hybrid model, which combined face-to-face instruction with the approaches of distance learning and multimedia methods, was designed to integrate modern learning methods and technologies into traditional university teaching.Este artículo describe las innovaciones en la educación universitaria búlgara en ingeniería: implantación de métodos de educación a distancia y de tecnologías virtuales y multimedia en la enseñanza de electrónica como resultado de un proyecto internacional de tres años. En conformidad con los objetivos del proyecto fue creada, una nueva unidad – un centro para el desarrollo e implantación de educación a distancia y multimedia - en la Facultad de Electrónica de la Universidad Técnica de Sofía. Fue diseñado un modelo híbrido que combinó la instrucción presencial con los planteamientos de la educación a distancia y las técnicas multimedia para integrar los modernos métodos y tecnologías educativas en la enseñanza tradicional de la universidad

Vlianie na mancozeba vurhu reprodukciata na dugova pusturva (Oncorhynchus mykiss W.) i natrupvane na negovia kancerogenen metabolit etilen tiourea v ribnite produkti

Pesticides can be taken up from the water and accumulated in tissues of hydrobionts, often becoming multiplied thousands of times higher in the organism than in the surrounding water. The dithiocarbamate mancozeb is applied in plant protection as fungicide. In recent years the amount of mancozeb used in Europe significantly increased. It is carcinogen due to its metabolite - ethylene thiourea (ETU), which causes thyroid and pituitary tumors. The purpose of this study is to determinate the quantity of ethylene thiourea in products of rainbow trout (Oncorhynchus mykiss W.), reared in environment containing permissible, according to the European law, amount of mancozeb. Seeking an answer to the question: is this concentration limit really safe for the reproduction of rainbow trout and can the more toxic metabolite - ETU, be accumulated in the fish eggs and fillet and afterwards make them harmful to the consumers? The study included 3 stages: feeding, analysis of ethylene thiourea in fish eggs and fillet by a new developed and validated HPLC (high performance liquid chromatography) method and study of the reproductive indicators. The assays of ETU in all analyzed samples (fish and water) were below the limit of quantification of the method, 0.05 mg*l-1, so fish do not accumulate the carcinogen degradation product of mancozeb and the maximum residue level of mancozeb is really safe for the humans as consumers. But these environmental conditions caused reproductive disorders. They can be partly compensated by using sperm activation medium for artificial insemination of trout eggs, but successful fertilization does not guarantee successful hatching, especially of eggs in trout farms with presence of mancozeb in water, even in allowable concentration. The presented results confirm previous investigation, that Salmonidae are very sensitive fish species, react to the lowest deviations in concentration levels of xenobiotics and are used for indicator of non-polluted water.Pesticidite, popadnali vuv vodoemite, mogat da se poemat ot obitavashtite gi hidrobionti. Te sa v systoqnie da gi natrupat v svoite tukani i tiahnata koncetracia da se uvelichi, dori hiliadi puti, sravnena s tazi vuv vodata. Ditiokarbamatut mancozeb se prilaga v rastitelnata zashtita kato fungicide. Prez poslednite godini negovoto izpolzvano v Evropa kolichestvo znachitelno narasna. Kancerogennostta na mancozeba se dulji na metabolita mu, etilen tiourea (ETU), koiato prichiniava tumori na shtitovidnata jleza i hipofizata. Celta na tova izsledvane e da se opredeli sudurjanieto na etilen tiourea v produkti ot dugova pusturva (Oncorhynchus mykiss W.), otglejdana v sreda, sudurjashta dopustimo, suglasno evropejskoto zakonodatelstvo, kolichestvo mancozeb. Tursen e otgovor na vuprosa: tazi dopustima koncentracia naistina li e bezopasna za reprodukciata na dugovata pusturva i moje li da bude natrupan po-toksichniat metabolit - ETU, v haivera i fileto, koeto da gi napravi vredni za potrebitelite? Tova prouchvane vklyuchva 3 etapa: hranene, analiz na etilen tiourea v haiver i ribno file chrez novo razraboten i validiran HPLC (visokoefektivna techna khromatografia) metod i izsledvane na reproduktivnite indikatori. Kolichestvoto na ETU vuv vsichki analizirani probi (riba i voda) pokazaha sudurvanie pod granicata na kolichestveno opredeliane na metoda, 0.05 mg*l-1; ribata ne natrupva kancerogennia product na razgrajdane na mancozeba i maksimalno dopustimata mu koncentracia e naistina bezopasna za potrebitelite. Tezi uslovia na okolnata sreda obache prichiniavat reproduktivni razstroistva. Te mogat da budat chastichno kompensirani chrez izpolzvane na spermo-aktivacionna sreda za iskustveno osemeniavane na haiver ot pusturva. No uspeshnoto oplojdane ne garantira uspeshnoto izlyupvane, osobeno na haiver v pusturvovi stopanstva s nalichie na macozeb vuv vodata, dori v dopustimata koncentracia