Application of a novel optimal control algorithm to a benchmark fed-batch fermentation process

A novel algorithm for solving nonlinear discrete time optimal control problems with model-reality differences is presented. The technique uses Dynamic Integrated System Optimisation and Parameter Estimation (DISOPE) which has been designed to achieve the correct optimal solution in spite of deficiencies in the mathematical model employed in the optimisation procedure. A method based on Broyden's ideas is used for approximating some derivative trajectories required. Ways for handling con straints on both manipulated and state variables are described. Further, a method for coping with batch-to- batch dynamic variations in the process, which are common in practice, is introduced. It is shown that the iterative procedure associated with the algorithm naturally suits applications to batch processes. The algorithm is success fully applied to a benchmark problem consisting of the input profile optimisation of a fed-batch fermentation process.

New developments in batch process input profile optimisation

A novel algorithm for solving nonlinear discrete time optimal control problems with model-reality differences is presented. The technique uses dynamic integrated system optimisation and parameter estimation (DISOPE) which achieves the correct optimal solution in spite of deficiencies in the mathematical model employed in the optimisation procedure. A new method for approximating some Jacobian trajectories required by the algorithm is introduced. It is shown that the iterative procedure associated with the algorithm naturally suits applications to batch chemical processes.

A new approach for the solution of the optimal set-point tracking problem for nonlinear systems

In this paper, a discrete time dynamic integrated system optimisation and parameter estimation algorithm is applied to the solution of the nonlinear tracking optimal control problem. A version of the algorithm with a linear-quadratic model-based problem is developed and implemented in software. The algorithm implemented is tested with simulation examples.

Reconfiguração dinâmica de estratégias distribuídas em dispositivos foundation fieldbus para a otimização de processos na indústria do petróleo

The petrochemical industry has as objective obtain, from crude oil, some products with a higher commercial value and a bigger industrial utility for energy purposes. These industrial processes are complex, commonly operating with large production volume and in restricted operation conditions. The operation control in optimized and stable conditions is important to keep obtained products quality and the industrial plant safety. Currently, industrial network has been attained evidence when there is a need to make the process control in a distributed way. The Foundation Fieldbus protocol for industrial network, for its interoperability feature and its user interface organized in simple configuration blocks, has great notoriety among industrial automation network group. This present work puts together some benefits brought by industrial network technology to petrochemical industrial processes inherent complexity. For this, a dynamic reconfiguration system for intelligent strategies (artificial neural networks, for example) based on the protocol user application layer is proposed which might allow different applications use in a particular process, without operators intervention and with necessary guarantees for the proper plant functioning

Arquitetura multiprocessada e reconfigurável para a síntese de redes de Petri em hardware

Uma arquitetura reconfigurável e multiprocessada para a implementação física de Redes de Petri foi desenvolvida em VHDL e mapeada sobre um FPGA. Convencionalmente, as Redes de Petri são transformadas em uma linguagem de descrição de hardware no nível de transferências entre registradores e um processo de síntese de alto nível é utilizado para gerar as funções booleanas e tabelas de transição de estado para que se possa, finalmente, mapeá-las num FPGA (Morris et al., 2000) (Soto and Pereira, 2001). A arquitetura proposta possui blocos lógicos reconfiguráveis desenvolvidos exclusivamente para a implementação dos lugares e das transições da rede, não sendo necessária a descrição da rede em níveis de abstração intermediários e nem a utilização de um processo de síntese para realizar o mapeamento da rede na arquitetura. A arquitetura permite o mapeamento de modelos de Redes de Petri com diferenciação entre as marcas e associação de tempo no disparo das transições, sendo composta por um arranjo de processadores reconfiguráveis, cada um dos quais representando o comportamento de uma transição da Rede de Petri a ser mapeada e por um sistema de comunicação, implementado por um conjunto de roteadores que são capazes de enviar pacotes de dados de um processador reconfigurável a outro. A arquitetura proposta foi validada num FPGA de 10.570 elementos lógicos com uma topologia que permitiu a implementação de Redes de Petri de até 9 transições e 36 lugares, atingindo uma latência de 15,4ns e uma vazão de até 17,12GB/s com uma freqüência de operação de 64,58MHz.

Formação de biofilme cristalino de Proteus mirabilis em cateter urológico

The indwelling urethral catheter has an important role for patients with urinary retention, bladder obstruction, neurological damage and other diseases. Urine contains minerals which precipitate in alkaline pH, crystallize and block the urological catheter. The crystallization of the ionic components of urine occurs in the presence of urease, an enzyme produced by Proteus mirabilis. This bacterium adheres to inanimate surfaces and forms biofilms. The aim of this study was to investigate the formation of crystalline biofilm on the luminal surface of siliconized latex catheters by means of scanning electron microscope, after channeling artificial urine infected with Proteus mirabilis. The experiment was performed in vitro using a dynamic flow system. The artificial urine compounds were salts of calcium, magnesium, phosphates, urea and egg albumin, and it was infected with Proteus mirabilis ATCC 25933. The urine flow was stopped after crystallization of the ionic components. Crystallization was observed after alkalinization of urine. Scanning electron microscopy showed the presence of crystals and morphologies typical of bacilli embedded in an amorphous mass on the internal lumen of the catheter. The present study showed that catheter encrustation may limit the use of long-term indwelling catheter. © SBEB - Sociedade Brasileira de Engenharia Biomédica.

Sistema de Aquisição de Baixo Custo para um Dinamômetro Biomédico

Objective: to create a purchasing system for optimizing a low cost device fabrication itself. Method: For this purpose was designed a system which is powered by a 12V battery center. The full bridge of "Wheatstone" is powered by the central battery set to 9V. Results: The sign of the strain has a range of 0 to 30 mV which is amplified filtered by a signal conditioner own manufacturing using an LM 324. The electrical signal then passes to vary from 0 to5V which will be processed in an analog input of PIC microcontroller. Tests for the registration and interpretation of data are through software MyOpenLab. Conclusion: The work is in progress and initial results suggest that the system will be able to measure muscular strength accurately and cost-effective.

Metodi numerici per lo studio di centri di lavoro ad alta velocità

A Machining Centre is nowadays a complex mechanical, electronic, electrical system that needs integrated design capabilities which very often require a high time-consuming effort. Numerical techniques for designing and dimensioning the machine structure and components usually requires different knowledge according to the system that have to be designed. This Ph. D Thesis is related about the efforts of the Authors to develop a system that allows to perform the complete project of a new machine optimized in its dynamic behaviour. An integration of the different systems developed, each of which respond to specific necessities of designer, is here presented. In particular a dynamic analysis system, based on a lumped mass approach, that rapidly allows to setup the drives of the machine and an Integrated Dynamic Simulation System, based on a FEM approach, that permit a dynamic optimization, are shown. A multilevel Data Base, and an operator interface module provide to complete the designing platform. The proposed approach represents a significant step toward the virtual machining for the prediction of the quality of the worked surface.

Formation and surface exchange of nitrous acid

Die salpetrige Säure (HONO) ist eine der reaktiven Stickstoffkomponenten der Atmosphäre und Pedosphäre. Die genauen Bildungswege von HONO, sowie der gegenseitige Austausch von HONO zwischen Atmosphäre und Pedosphäre sind noch nicht vollständig aufgedeckt. Bei der HONO-Photolyse entsteht das Hydroxylradikal (OH) und Stickstoffmonooxid (NO), was die Bedeutsamkeit von HONO für die atmosphärische Photochemie widerspiegelt.rnUm die genannte Bildung von HONO im Boden und dessen anschließenden Austausch mit der Atmosphäre zu untersuchen, wurden Messungen von Bodenproben mit dynamischen Kammern durchgeführt. Im Labor gemessene Emissionsflüsse von Wasser, NO und HONO zeigen, dass die Emission von HONO in vergleichbarem Umfang und im gleichen Bodenfeuchtebereich wie die für NO (von 6.5 bis 56.0 % WHC) stattfindet. Die Höhe der HONO-Emissionsflüsse bei neutralen bis basischen pH-Werten und die Aktivierungsenergie der HONO-Emissionsflüsse führen zu der Annahme, dass die mikrobielle Nitrifikation die Hauptquelle für die HONO-Emission darstellt. Inhibierungsexperimente mit einer Bodenprobe und die Messung einer Reinkultur von Nitrosomonas europaea bestärkten diese Theorie. Als Schlussfolgerung wurde das konzeptionelle Model der Bodenemission verschiedener Stickstoffkomponenten in Abhängigkeit von dem Wasserhaushalt des Bodens für HONO erweitert.rnIn einem weiteren Versuch wurde zum Spülen der dynamischen Kammer Luft mit erhöhtem Mischungsverhältnis von HONO verwendet. Die Messung einer hervorragend charakterisierten Bodenprobe zeigte bidirektionale Flüsse von HONO. Somit können Böden nicht nur als HONO-Quelle, sondern auch je nach Bedingungen als effektive Senke dienen. rnAußerdem konnte gezeigt werden, dass das Verhältnis von HONO- zu NO-Emissionen mit dem pH-Wert des Bodens korreliert. Grund könnte die erhöhte Reaktivität von HONO bei niedrigem pH-Wert und die längere Aufenthaltsdauer von HONO verursacht durch reduzierte Gasdiffusion im Bodenporenraum sein, da ein niedriger pH-Wert mit erhöhter Bodenfeuchte am Maximum der Emission einhergeht. Es konnte gezeigt werden, dass die effektive Diffusion von Gasen im Bodenporenraum und die effektive Diffusion von Ionen in der Bodenlösung die HONO-Produktion und den Austausch von HONO mit der Atmosphäre begrenzen. rnErgänzend zu den Messungen im Labor wurde HONO während der Messkampagne HUMPPA-COPEC 2010 im borealen Nadelwald simultan in der Höhe von 1 m über dem Boden und 2 bis 3 m über dem Blätterdach gemessen. Die Budgetberechnungen für HONO zeigen, dass für HONO sämtliche bekannte Quellen und Senken in Bezug auf die übermächtige HONO-Photolyserate tagsüber vernachlässigbar sind (< 20%). Weder Bodenemissionen von HONO, noch die Photolyse von an Oberflächen adsorbierter Salpetersäure können die fehlende Quelle erklären. Die lichtinduzierte Reduktion von Stickstoffdioxid (NO2) an Oberflächen konnte nicht ausgeschlossen werden. Es zeigte sich jedoch, dass die fehlende Quelle stärker mit der HONO-Photolyserate korreliert als mit der entsprechenden Photolysefrequenz, die proportional zur Photolysefrequenz von NO2 ist. Somit lässt sich schlussfolgern, dass entweder die Photolyserate von HONO überschätzt wird oder dass immer noch eine unbekannte, HONO-Quelle existiert, die mit der Photolyserate sehr stark korreliert. rn rn

The proapoptotic Bcl-2 family member Bim plays a central role during the development of virus-induced hepatitis

The proapoptotic Bcl-2 homolog Bim was shown to control the apoptosis of both T cells and hepatocytes. This dual role of Bim might be particularly relevant for the development of viral hepatitis, in which both the sensitivity of hepatocytes to apoptosis stimuli and the persistence of cytotoxic T cells are essential factors for the outcome of the disease. The relevance of Bim in regulating survival of cytotoxic T cells or induction of hepatocyte death has only been investigated in separate systems, and their relative contributions to the pathogenesis of T cell-mediated hepatitis remain unclear. Using the highly dynamic model system of lymphocytic choriomeningitis virus-mediated hepatitis and bone marrow chimeras, we found that Bim has a dual role in the development of lymphocytic choriomeningitis virus-induced, T cell-mediated hepatitis. Although the absence of Bim in parenchymal cells led to markedly attenuated liver damage, loss of Bim in the lymphoid compartment moderately enhanced hepatitis. However, when both effects were combined in Bim(-/-) mice, the effect of Bim deficiency in the lymphoid compartment was overcompensated for by the reduced sensitivity of Bim(-/-) hepatocytes to T cell-induced apoptosis, resulting in the protection of Bim(-/-) mice from hepatitis.

Suitability of Common Collagen Scaffolds for Anterior Cruciate Ligament Repair

Introduction: Anterior cruciate ligament (ACL) injuries are very common; in Germany incidence of ACL ruptures is estimated at 32 per 100 000 in the general population and in the sports community this rate more than doubles. Current gold standard for anterior cruciate lig- ament repair is reconstruction using an autograft [1]. However, this approach has shown some limitations. A new method has been her- alded by the Knee Team at the Bern University Hospital (Inselspital) and the Sonnenhof clinic called Dynamic Intraligamentary Stabilization (DIS), which keeps ACL remnants in place in order to promote biologi- cal healing and makes use of a dynamic screw system [2]. The aim of this study was to investigate the cytocompatibility of collagen patches in combination with DIS to support regeneration of the ACL. The spe- cific hypothesis we tested was whether MSCs would differentiate towards TCs in co-culture. Materials and methods: Primary Tenocytes (TCs) and human bone marrow derived mesenchymal stem cells (MSCs) were harvested from ACL removed during knee prothesis or from bone marrow aspirations (Ethical Permit 187/10). Cells were seeded on two types of three dimensional carriers currently approved for cartilage repair, Novocart (NC, B. Brown) and Chondro-Gide (CG, Geistlich). These scaffolds comprise collagen structures with interconnecting pores originally developed for seeding of chondrocytes in the case of CG. ~40k cells were seeded on punched zylindrical cores of 8 mm in Ø and cultured on CG or NC patches for up to 7 days. The cells were either cultured as TC only, MSC only or co-cultured in a 1:1 mix on the scaffolds and on both sides of culture inserts (PET, high density pore Ø 0.4 mm, BD, Fal- con) with cell-cell contact. We monitored DNA content, GAG and HOP-content, tracked the cells using DIL and DIO fluorescent dyes (Molecular Probes, Life technologies) and confocal laser scanning and SEM microscopy as well as RT-PCR of tenocyte specific markers (i.e. col 1 and 3, TNC, TNMD, SCXA&B, and markers of dedifferentiation ACAN, col2, MMP3, MMP13). Finally, H&E stain was interpreted on cryosections and SEM images of cells on the scaffold were taken. Results: ThecLSMimagesshowedcellproliferationoverthe7dayson both matrices, however, on CG there were much fewer MSCs attached than on NC. SEM images showed a roundish chondrocyte-like pheno- type of cells on CG whereas on NC the phenotype was more teno- cyte-like (Fig. 1). Gene expression of both, MSC and TC seem to confirm a more favorable environment in 3D for both patches rather than monolayer control.

Mesenchymal stem cells and collagen patches for anterior cruciate ligament repair

AIM: To investigate collagen patches seeded with mesenchymal stem cells (MSCs) and/or tenocytes (TCs) with regards to their suitability for anterior cruciate ligament (ACL) repair. METHODS: Dynamic Intraligamentary Stabilization (DIS) utilizes a dynamic screw system to keep ACL remnants in place and promote biological healing, supplemented by collagen patches. How these scaffolds interact with cells and what type of benefit they provide has not yet been investigated in detail. Primary ACL-derived TCs and human bone marrow derived MSCs were seeded onto two different types of 3D collagen scaffolds, Chondro-Gide® (CG) and Novocart® (NC). Cells were seeded onto the scaffolds and cultured for 7 days either as a pure populations or as “premix” containing a 1 : 1 ratio of TCs to MSCs. Additionally, as controls, cells were seeded in monolayers and in co-cultures on both sides of porous high-density membrane inserts (0.4µm). We analyzed the patches by real time polymerase chain reaction (RT-PCR), glycosaminoglycan (GAG), DNA and hydroxy-proline (HYP) content, was determined. To determine cell spreading and adherence in the scaffolds microscopic imaging techniques, i.e. confocal laser scanning microscopy (cLSM) and scanning electron microscopy (SEM), were applied. RESULTS: CLSM and SEM imaging analysis confirmed cell adherence onto scaffolds. The metabolic cell activity revealed that patches promote adherence and proliferation of cells. The most dramatic increase in absolute metabolic cell activity was measured for CG samples seeded with tenocytes or a 1:1 cell premix. Analysis of DNA content and cLSM imaging also indicated MSCs were not proliferating as nicely as tenocytes on CG. The HYP to GAG ratio significantly changed for the premix group, resulting from a slightly lower GAG content, demonstrating that the cells are modifying the underlying matrix. Real-time quantitative polymerase chain reaction data indicated that MSCs showed a trend of differentiation towards a more tenogenic-like phenotype after 7 days. CONCLUSION: CG and NC are both cyto-compatible with primary MSCs and TCs; TCs seemed to perform better on these collagen patches than MSCs.

Cambio para optimizar la calidad de las prestaciones del Programa Oncológico Provincial

Considerando el alto costo farmacológico de los tratamientos oncológicos actuales y de los anticuerpos monoclonales pautados para diferentes terapias que están apareciendo y que serán prácticamente lo único que se use en el futuro para diferentes diagnósticos, el Programa Oncológico Provincial cubre sin cargo alguno las necesidades de los pacientes atendidos en Hospitales Estatales, cumpliendo una función social, dispensando los medicamentos solicitados por el médico tratante, en forma confiable, segura, y con equidad para recibir el tratamiento adecuado en el momento oportuno. Los recursos que pueden ser destinados al gasto farmacéutico son limitados, por lo que es necesario racionalizar el consumo y priorizar en la asignación de estos recursos a las opciones que presentan mayores ventajas económicas, basada en mantener una mejor relación costo/beneficio, repercutiendo de manera directa en los enfermos y en la sociedad en general. En este trabajo, se analiza el sistema de adquisición de drogas oncológicas usado por el Programa Oncológico Provincial realizando una comparación entre el sistema de compras original y el adoptado por el Programa en el año 2005. Se evalúa el periodo 2001-2007, en base a diversos indicadores y datos estadísticos, para determinar si ha mejorado la calidad de las prestaciones, si ha disminuido la demanda contenida y si se ha logrado mejorar la relación costo / beneficio, controlando así el gasto sanitario global lo que constituiría una inversión rentable para el sistema de salud. Los resultados indican que el nuevo sistema adoptado por el Programa Provincial de Oncología ha mejorado la provisión de medicamentos y garantiza mayor calidad en las prestaciones, pero estos resultados pueden ser superados. También muestra la gravedad del problema de la utilización de los nuevos fármacos monoclonales.

Dissolved Si isotope composition measured in water samples during METEOR cruises M77/3 and M77/4

Silicon isotopes are a powerful tool to investigate the cycling of dissolved silicon (Si). In this study the distribution of the Si isotope composition of dissolved silicic acid (d30Si(OH)4) was analyzed in the water column of the Eastern Equatorial Pacific (EEP) where one of the globally largest Oxygen Minimum Zones (OMZs) is located. Samples were collected at 7 stations along two meridional transects from the equator to 14°S at 85°50'W and 82°00'W off the Ecuadorian and Peruvian coast. Surface waters show a large range in isotope compositions d30Si(OH)4 (+2.2 per mil to +4.4 per mil) with the highest values found at the southernmost station at 14°S. This station also revealed the most depleted silicic acid concentrations (0.2 µmol/kg), which is a function of the high degree of Si utilization by diatoms and admixture with waters from highly productive areas. Samples within the upper water column and the OMZ at oxygen concentrations below 10 µmol/kg are characterized by a large range in d30Si(OH)4, which mainly reflects advection and mixing of different water masses, even though the highly dynamic hydrographic system of the upwelling area off Peru does not allow the identification of clear Si isotope signals for distinct water masses. Therefore we cannot rule out that also dissolution processes have an influence on the d30Si(OH)4 signature in the subsurface water column. Deep water masses (>2000 m) in the study area show a mean d30Si(OH)4 of +1.2±0.2 per mil, which is in agreement with previous studies from the eastern and central Pacific. Comparison of the new deep water data of this study and previously published data from the central Pacific and Southern Ocean reveal substantially higher d30Si(OH)4 values than deep water signatures from the North Pacific. As there is no clear correlation between d30Si(OH)4 and silicic acid concentrations in the entire data set the distribution of d30Si(OH)4 signatures in deep waters of the Pacific is considered to be mainly a consequence of the mixing of several end member water masses with distinct Si isotope signatures including Lower Circumpolar Deep Water (LCDW) and North Pacific Deep Water (NPDW).

Análisis dinámico in situ de transmisores de presión capacitivos

Los sensores de presión capacitivos tipo Rosemount son ampliamente utilizados en las centrales nucleares para la medida de la presión, el caudal y el nivel. Están unidos a las líneas de proceso de la central mediante líneas sensoras siendo el mantenimiento del sistema sensor-línea fundamental para mantener la seguridad en la planta. La vigilancia in situ del sistema en su conjunto, sensor-línea, se suele realizar mediante la medida del tiempo de respuesta del transmisor de presión con las técnicas de análisis de ruido. Sin embargo, determinadas averías como la pérdida de aceite de su cámara interna no son detectables por medio de la medida del tiempo de respuesta, ya que éste apenas varía su valor en una fase incipiente del síndrome. No obstante, la mejora de la descripción dinámica del sensor podría servir para detectar dichas averías. En laboratorio se ha demostrado que la función de transferencia del sistema sensor-línea puede tener más de un polo real, y en consecuencia, el modelo de tres polos (dos polos complejos conjugados y uno real) utilizado hasta ahora en otros trabajos podría sustituirse por uno de cuatro o incluso cinco. En este trabajo se propone utilizar técnicas de vigilancia in situ basadas en el análisis de ruido y en el Dynamic Data System para ampliar la descripción dinámica del sensor y con ello mejorar las posibilidades de diagnóstico de averías como el síndrome de la pérdida de aceite del sensor en fases incipientes. Se han analizado varias medidas de planta con la metodología propuesta y se muestran los resultados obtenidos.