Global e-learning tendencies and possibilities of using the internet for vocational and educational training

The Virtual Training Center (VTC) integrates the ideas of media-based learning environments into the idea of the learning platform which has increasingly influenced theoretical discussions at international congresses (e.g. Learntec 2000, Karlsruhe, see www.learntec.de). The VTC simulates a training center in the web and serves as a platform of internet or intranet based courses and self-learning media. Seminars and workshops can be held, media and documents can be worked on and administered and know-how can be exchanged. The basic idea of the VTC is to create a web-based infrastructure which shelters all possibilities of web-based teaching, learning and training

“completación dual concéntrica con bomba electrosumergible y flujo natural de un pozo en el oriente ecuatoriano para revestimiento de 9-5/8” y liner de 7”

Este proyecto tiene como finalidad mostrar una alternativa para el diseño de una Completación Dual Concéntrica con Bomba Electrosumergible y Flujo Natural para revestimiento de 9 5/8” y liner de 7”. Se procede a estudiar las propiedades de las rocas y fluidos del campo, se explica los tipos de yacimientos y se estudia brevemente los tipos de empuje presentes. Se realiza una explicación sobre las Completaciones Duales y se describe las herramientas usadas en nuestra completación, así como el equipo electrosumergible y el ensamblaje para producir por flujo natural. Se muestra el diseño de nuestra Completación Dual Concéntrica para revestimiento de 9 5/8” y Liner 7” con el respectivo análisis técnico y procedimiento operacional, además detallamos los cálculos de las profundidades de la completación dual de nuestro pozo ESPOL FEV-01. Se explica el estudio económico de la Completación Dual llegando a evaluar la rentabilidad de nuestro diseño, presentando las respectivas conclusiones y recomendaciones de una alternativa eficaz en la Completación de pozos en el Oriente Ecuatoriano.ESPO

THERMODYNAMIC ASPECTS OF DESIGNING THE NEW SIEMENS HIGH PRESSURE STEAM TURBINE WITH OVERLOAD VALVE FOR SUPERCRITICAL APPLICATIONS

Abstract Huge coal fueled power plants in the 1000MW el class are requiring high efficient steam turbines which can handle supercritical steam conditions up to 300bar and 600°C. Besides these boundary conditions, the capability for stabilising the grid fluctuations is also one key requirement. Siemens is focussing on this topic by using the so-called overload valve(s), which enhance the maximum amount of main steam mass flow entering the high-pressure turbine by use of additional valve(s). Using this technique, a power increase in the range of up to 20% is theoretically achievable. Siemens PG has collected a lot of positive service experiences throughout the past decades with this technique, and therefore this principle is being well established in the field. The connection between the additional steam mass flow passing through the overload valve and the standard blading path is somewhat downstream from the first stage. These connecting points can be varied (for this current turbine design) -if necessary -between the third and fifth stage after the turbine inlet. From an economic point of view, the approach of extending the power range via overload valves is even better than throttling the whole machine during standard operating condition and opening the valves fully at certain peak load requirements. Historically based, Siemens designs and manufactures reaction stages, 'reaction turbines', which must be thrust compensated via a separate piston to equalize and reduce the overall axial thrust down to a small number. Increasing the main steam temperatures up to the previously mentioned levels makes the internal cooling device of this thrust equilibrium piston a major key point for the whole turbine. No external cooling pipe-work or special materials are required. In • Developing a turbine-internal cooling system for the thrust equilibrium/balancing piston as well as for the inner and outer casing. • Evaluation of staged piston with new internal cooling system adjusted for the impact on heat rate. • Quantification of all related mass flows, temperatures and pressures. • Axial thrust calculation to determine the required diameters of the staged piston. • General remarks concerning efficiency behaviour of hp-turbines with different geometrical designs. Turbine internal bypass cooling A schematic overview of the internal cooling concept is given in Due to this temperature reduction by the cooling steam, the turbine is capable of handling 600°C main steam temperatures and -in principle -pressure levels up to 300bar. As a consequence, the wall-thickness of the outer casing could be reduced significantly, which is a benefit in overall weight (and therefore costs) and start up behaviour. In addition to these advantages, all bolts for the inner casings could be manufactured out of well established material. Without the internal bypass cooling, these bolts must be made out of a special (very expensive) not proven material. Another major advantage could be seen in the low cycle fatigue performance of the inner casing at the overload admission regime. Without the internal bypass cooling system, the inner casing has to withstand high temperature gradients when the overload valve(s) switch(es) on or off. With this cooling principle, temperatures remain almost constant, regardless of the amount of steam admission. In In front of the first hp-drum a low reaction diagonal inlet stage (impulse blade design) is designated to rapidly reduce the high inlet temperatures, typically with a high stage load number. The corresponding stator vanes are being built as one ring, avoiding high leakage losses compared to conventional stator vanes. The guide vanes of the diagonal stage create a swirl in the direction of rotation, which reduces the static temperature for the first rotor (blade-roots). Additionally, the (often) limited axial length of the blading path can be used more effectively; the possible enthalpy drop within the turbine is enlarged. Different techniques handling overload requirements A brief overview of possible concepts and their impact on the heat rate versus different power settings is given in the next figure, Pure throttling of the turbine control valves is a simple technique for supporting frequency control demands from the grid. The turbine operates up to the rated conditions with the control valves throttled. They can be opened quickly if more power is required. The increased electrical output available to the grid is approx. 3s after reduction of the throttling. A 5% reduction in throttling results in an approx. 2.5% increase in electrical output. If the control valve is throttled by 2%, the increased electrical output from opening the valve is approx. 1.2%. Reducing the throttling from 5% to 2% improves the heat requirement due to a reduction in throttling losses. Using this concept, the best heat rat values are obtained during the peak load requirements of the turbine. The valves are fully open at this position without causing any additional throttling losses. A second alternative technique to handle overload requirements is the use of so called 'control stages' in front of the blade path of the high pressure turbine, see Lowest heat rate during sliding pressure mode No further pressure increase in front of the hpturbine required when the extra power is needed Minimal radial forces acting on the shaft compared to the control-stages principle Fewer components required during maintenance Short outage time due to less complexity In conjunction with the internal bypass cooling pipe work, some additional benefits could be outlined: Symmetrical steam mass flow around the inner casing, which reduces the thermal stress and thermal deformation within the turbine, leading to minimal required radial clearances and therefore maximal overall efficiency and best operation behavior 'Preheating' of some major turbine components, which will result in a reduction of the required heat up time Almost constant temperature level in critical turbine sections, independent of the overload admission whether active or not No impact on turbine life time with respect to numbers of overload cycles As already mentioned in the introductory phrase, Siemens PG has collected a lot of positive field experiences throughout the past decades with the overload-technique, starting in the mid 50s. Today, more than 40 high pressure turbines have been delivered using the overload admission principle. The position inside the turbine at which the admission steam is mixed together with the main steam -varies for different turbine types -and depends of the specified amount of extra power. Location of the overload steam admission within the newly designed hp-turbine In this chapter some calculations regarding the connection of the overload steam admission are presented. The later the overload steam admission occurs, the higher the power or mass flow gain is achieved. By bypassing an increasing number of front stages of a turbine through separate overload valves, more and more additional mass flow can be fed into the turbine without increasing the main steam pressure. Presuming that the cooling steam for the staged piston is being extracted one stage before the overload inlet -as shown in On the other hand, 'excessively cold steam' for the piston and for the outer surface of the inner casing is not recommended. The temperature gradient across the inner casing has to stay within certain limits. With the given internal bypass cooling concept it is principally possible to maintain the 'optimum' cooling temperature for the inner and outer casing as well as for the large piston diameter. The next More information concerning the required piston diameter D 2 is given in A sketch of the internal bypass cooling concept for the hpturbine including the major data for the piston and pipe-work is drawn in 5 Copyright © 2006 by ASME Additionally, the heat rate effect of a staged piston versus a standard piston was being evaluated. Significant lower heat rate behaviour was calculated for the staged piston compared to a 'conventional' one. On one hand, the sealing length for the staged piston could be designed longer than the corresponding length of the standard piston because the main steam inlet area could be placed above the small piston diameter, see Further on, the splitting of each axial sealing length on the piston was optimized. The best variant of all possible combinations for l k1 , l k2 and l k3 was chosen for the current design, which leads to the minimal heat-rate value, see To summarize, during the design phase of the new hp-turbine the overall concept was optimised, taken the followingsometimes counteracting parameters -into account: The resulting leakage mass flow throughout all sealing as a function of the pitch, radial clearance between the sealing strips and the metal as well as the radial clearance between metal and metal, length, existing pressure difference and the steam density The required cooling temperature The required piston diameter to balance the axial thrust when changing the position of the internal bypass cooling concept Blading interactions and restrictions of thinkable positions for the internal bypass cooling within the blading path Mechanical demands Design demands Rotor-dynamic criteria Evaluation of different design features for the newly developed turbine having the internal bypass cooling with respect to the heat rate, power output and hp-efficiency Looking at the power output, heat rate and the hp-efficiency of the new hp-turbine, a comparison of different design features for this turbine is quite important. In a sensitivity study the following major points were analyzed and evaluated. With the new cooling device, the outer surface of the inner casing is cooled down to a certain level. Taken this effect into account leads to the fact that the integral-temperature of the inner casing is not that much higher than the shafttemperature, compared to a 'standard' turbine. Therefore, the radial clearances across the piston and across the first hpdrum are reduced. However, the metal to metal clearances are kept constant to comparable turbines -the so called 'cold' radial clearances -at no load conditions. Due to that more homogeneous temperature field within the turbine at operating conditions the radial clearances will then be smaller. Especially, a reduction in the leakage mass flow across the larger piston -at turbine operating conditionsplays quite an important role in the overall heat rate of the whole turbo-set. Without having the internal bypass cooling, the available axial length for the blading path increases because one extraction slot into the turbine blade-path for this purpose becomes obsolete, see A relatively huge impact on the inner efficiency could be found when the connecting point of the internal cooling could be varied in a wide range. For instance, by lowering the pressure before the larger piston diameter of the staged piston, when connecting this position to a point further downstream in the machine, the leakage mass flow across that piston reduces accordingly. A thermodynamic optimum of this connecting point is somewhere in the middle of the machine. But, this comparison is only valid for turbines with a 'free choice' of the connecting point, which doesn't have an overload capability, mechanic criteria or casting restrictions to fulfil. As well, those that definitely don't prohibit the extraction of too 'cold' cooling steam from the expansion line. When connecting the internal cooling far downstream, the turbine costs will rise. The expensive outer casing at the front end, with 10%Chromium content, gets bigger, whereas the cheaper rear end (1%Cr) gets smaller at the same time. Summary: The net effect of the new cooling principle is at the very least, heat rate invariant (conservative comparison/approximation) or slightly better compared to a conventional turbine design. On average, one will 'loose' half a blade-row, but be able to reduce the radial clearances across the piston as well as for the first drum. Impact of the piston cooling steam from the inner casin

Diesel-elektrischer Hybridantrieb für kommunale Arbeitsmaschinen

Angepasste Hybridantriebe in mobilen Arbeitsmaschinen (off-highway Anwendungen) versprechen wegen der typischerweise auftretenden Lastzyklen mit ausgeprägten, häufigen und schnellen Laständerungen folgende Vorteile: geringerer Kraftstoffverbrauch, Einsatz eines Dieselmotors kleinerer Leistung, dadurch Erfüllung strikter werdender Emissionsvorschriften (TIER 4, EURO 5) ohne oder mit reduzierter Abgasnachbehandlung, Lärmreduktion, weitere Einsparpotenziale durch Elektrifizierung der Fahrzeugfunktionen möglich (Erhöhung des Hybridisierungsgrads), höhere Produktivität durch höhere Antriebsdynamik.Several duty cycles have been performed with the LADOG multipurpose community vehicle equipped with a conventional diesel engine drive train. Based on these results, simulation calculations have been performed to estimate the fuel savings which can be achieved if this mobile machine would be equipped with a parallel diesel-electric hybrid drive train. Two hybrid configurations were considered, one with the original diesel engine and one with a right-sized, i.e. a smaller diesel engine. Several operation modes of the hybrid were simulated like start-stop function, recuperation, boosting and diesel engine operation for optimized fuel consumption (characteristic mapping). The simulation results showed fuel savings up to 20 % even for this community vehicle which seemed not to be attractive for hybridization. This LADOG vehicle is actually modified by the hybrid drive train substituting the pure diesel drive train. The experimental proof of the simulations is under way

Soluble α2-macroglobulin receptor is increased in endotracheal aspirates from infants and children after cardiopulmonary bypass

ObjectiveCytokine dysregulation contributes to the systemic inflammatory response after cardiopulmonary bypass. Clearance of cytokine binding proteins may be important in the resolution of inflammation. Our aim was to determine whether the cytokine binding protein α2-macroglobulin and its soluble receptor were upregulated in endotracheal aspirates from infants and children undergoing cardiopulmonary bypass.MethodsSeventy tracheal aspirates were collected before and after cardiopulmonary bypass from 35 infants and children undergoing surgical correction of congenital heart defects. α2-Macroglobulin and the soluble α2-macroglobulin receptor were identified by Western blot. With the use of multi-analyte cytokine profiling, pro-inflammatory and anti-inflammatory cytokines were quantified, normalized to total protein, and expressed as ratios. Paired t tests and Wilcoxon signed-rank tests were performed between prebypass and postbypass samples. Correlations were examined among α2-macroglobulin, soluble α2-macroglobulin receptor, cytokine ratios, and the clinical variables of cardiopulmonary bypass, aortic crossclamp, and circulatory arrest times.Resultsα2-Macroglobulin increased by 50% (mean densitometry increase 82,683 ± 184,594, P = .012), and soluble α2-macroglobulin receptor increased by 17% (mean densitometry increase 506,148 ± 687,037, P = .0001) after cardiopulmonary bypass. The ratio of interleukin-8/interleukin-4 increased by 136% (P = .0001), and interleukin-8/interleukin-10 increased by 102% (P = .001). The increase in soluble α2-macroglobulin receptor was positively correlated with the ratios of interleukin-8/interleukin-4 and interleukin-8/interleukin-10. There were no statistically significant positive correlations between the increase in α2-macroglobulin or soluble α2-macroglobulin receptor and measured clinical variables.ConclusionsWe report for the first time the upregulation of α2-macroglobulin and soluble α2-macroglobulin receptor in tracheal aspirates after cardiopulmonary bypass in infants and children. Soluble α2-macroglobulin receptor correlates with increased α2-macroglobulin and a disproportionate increase in pro-inflammatory to anti-inflammatory cytokine ratios

Tumour thickness in oral cancer using an intra-oral ultrasound probe

To investigate tumour-thickness measurement with an intra-operative ultrasound (US) probe. A retrospective data analysis was undertaken for a total of 65 patients with a T1-2 oral cavity cancer, who were seen at a tertiary referral centre between 2004 and 2010. The correspondence between tumour thickness measured by ultrasonography and histopathology was assessed by Pearson's correlation coefficient, and also between tumour thickness and the development of neck metastasis. In 11 cases, intra-oral measurement was not optimal due to limited mouth opening (n = 2) or impossibility to depict the lesion (n = 9). Tumour thickness measured by US correlated well with histopathology (n = 23, R = 0.93). Tumour thickness of a parts per thousand currency sign7 mm carries a risk of lymph node metastasis of 12%, whereas in tumours exceeding 7 mm this risk is 57% (p = 0.001). Twenty-five percent developed neck metastasis and 19% had local recurrence. Tumour thickness is an important predictive marker for lymph node metastases. As such, it can help in decision-making with regard to management of the primary tumour and neck. Based upon our findings, a wait-and-see policy is only warranted for superficial lesions with tumour thickness of less than 7 mm, but only if regular follow-up using US-guided aspiration of the neck is ensure

Nueva metodología PIP orientada a las Buenas Prácticas para el desarrollo de software

The main objective of this article is to present the new methodology of Patricio Integrated Programming (PIP), of good practices for the improvement and development of software. Recent studies and similar current markets are setting trends in software engineering, whose key features meet the needs of speed, flexibility and external variations that make your environment become a competitive advantage by increasing productivity and responding to needs. of customers in the shortest possible time to offer greater value to the company. The proposal of the PIP methodology, will allow to control and monitor the development of each of the phases of the project, applying good practices, the new methodology was created from the phases of the Extreme Programming (XP), Scrum and ISO methodologies. /IEC/IEEE 29119. The goal of creating models that differentiate between structured and agile methods to determine which is best suited for a particular project.Este artículo tiene como objetivo principal dar a conocer la nueva metodología de Programación Integrada Patricio (PIP), de buenas prácticas para la mejora y desarrollo de software. Estudios recientes y mercados actuales similares están marcando tendencias en la ingeniería de software, cuyas características clave satisfacen las necesidades de velocidad, flexibilidad y variaciones externas que hacen que su entorno, nos convierta en una ventaja competitiva al incrementar la productividad y dar respuesta a las necesidades de los clientes en el menor tiempo posible para ofrecer un mayor valor a la empresa. La propuesta de la metodología PIP, permitirá poder controlar y dar seguimiento al desarrollo de cada una de las fases del proyecto, aplicando buenas prácticas, la nueva metodología fue creada a partir de las fases de las metodologías Programación extrema (XP), Scrum y ISO/IEC/IEEE 29119. El objetivo de la creación de modelos que diferencian entre métodos estructurados y ágiles para determinar cuál es el más adecuado para un proyecto en particular

Observer Variation of 2-Deoxy-2-[F-18]fluoro-d-Glucose-Positron Emission Tomography in Mediastinal Staging of Non-Small Cell Lung Cancer as a Function of Experience, and its Potential Clinical Impact

Purpose: To test the extent of variation among nuclear medicine physicians with respect to staging non-small cell lung cancer with positron emission tomography (PET). Procedures: Two groups of nuclear medicine physicians with different levels of PET experience reviewed 30 PET scans. They were requested to identify and localize suspicious mediastinal lymph nodes (MLN) using standardized algorithms. Results were compared between the two groups, between individuals, and with expert reading. Results: Overall we found good interobserver agreement (kappa 0.65). Experience with PET translated into a better ability to localize MLN stations (68 % vs. 51%, respectively), and experienced readers appeared to be more familiar with translating PET readings into clinically useful statements. Conclusions: Although our results suggest that clinical experience with PET increases observers _ ability to read and interpret results from PET adequately, there is room for improvement. Experience with PET does not necessarily improve the accuracy of image interpretation

Aplicación red VOIP para la mejora del servicio de comunicación en la empresa peruana

The objective of this research was to evaluate the application of VOIP to improve the communication service in the Peruvian company, currently many companies in Peru need to communicate between branches located in different provinces; For this, they need a technological solution that allows them to provide a quality communication service at a reduced cost. At present, there are still companies that use an analog communication system that is becoming obsolete over time, since its functions are limited before the requirements of the personnel of these Peruvian companies. Additionally, many Peruvian companies have communication problems (communication interference, low audio quality and signal loss in communication), this generates the loss of coordination between the offices and the increase in high expenses in fixed telephony without obtaining optimal results. Therefore, the solution proposal is the implementation of a VoIP network, through equipment and free software that allows meeting the communications needs of the Peruvian company, the proposal presented is economical, scalable and above all safe that currently exists in the current market.El objetivo de esta investigación fue evaluar la aplicación de VOIP para mejorar el servicio de comunicación en la empresa peruana, actualmente muchas empresas en el Perú necesitan comunicarse entre sucursales ubicadas en diferentes provincias; para ello necesitan una solución tecnológica que permita disponer el servicio de comunicación de calidad y a costo reducido. En la actualidad aún existen empresas que usan sistema de comunicación analógica que con el tiempo está quedando obsoleta, ya que sus funciones se muestran limitadas antes los requerimientos del personal de dichas empresas peruanas. Adicionalmente muchas empresas peruanas cuentan con problemas de comunicación (interferencias de comunicación, baja calidad de audio y perdida de señal en la comunicación), esto genera la perdida de coordinación entre las sedes y el incremento de gastos elevados en telefonía fija sin obtener resultados óptimos. Por consiguiente, la propuesta de solución es la implementación de una red VoIP, a través de equipamientos y softwares libres que permitan cumplir las necesidades de comunicaciones de la empresa peruana, la propuesta presentada es económica, escalable y sobre todo segura que actualmente existe en el mercado actual

A Systematic Classification of the Congenital Bronchopulmonary Vascular Malformations: Dysmorphogeneses of the Primitive Foregut System and the Primitive Aortic Arch System

Purpose: We reviewed the cases of 33 patients from our clinic and 142 patients from the literature with congenital bronchopulmonary vascular malformations (BPVM), systematically analyzed the bronchopulmonary airways , pulmonary arterial supplies, and pulmonary venous drainages, and classified these patients by pulmonary malinosculation( PM). Materials and Methods: From January 1990 to January 2007, a total of 33 patients (17 men or boys and 16 women or girls), aged I day to 24 years (median, 2.5 months), with congenital BPVM were included in this study. Profiles of clinical manifestations, chest radiographs, echocardiographs , esophagographs, computer tomography (CT), magnetic resonance imaging (MRI) , magnetic resonance angiography (MRA ), cardiac catheterizations with angiography, contrast bronchographs, bronchoscopies, chromosomal studies, surgeries, and autopsies of these patients were analyzed to confirm the diagnosis of congenital BPVM. A total of 142 cases from the literature were also reviewed and classified similarly. Results: The malformations of our 33 patients can be classified as type A isolated bronchial PM in 13 patients, type B isolated arterial PM in three, type C isolated venous PM in two, type D mixed bronchoarterial PM in five, type F mixed arteriovenous PM in one, and type G mixed bronchoarteriovenous PM in nine. Conclusion: Dysmorphogeneses of the primitive foregut system and the primitive aortic arch system may lead to haphazard malinosculations of the airways, arteries, and veins of the lung. A systematic classification of patients with congenital BPVM is clinically feasible by assessing the three basic bronchovascular systems of the lung independently